diff --git a/TEST_MAPPING b/TEST_MAPPING
index 7eb935e..4774866 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -53,6 +53,9 @@
       "name": "connectivity_native_test"
     },
     {
+      "name": "libclat_test"
+    },
+    {
       "name": "netd_updatable_unit_test"
     },
     {
@@ -80,16 +83,10 @@
       "keywords": ["netd-device-kernel-4.9", "netd-device-kernel-4.14"]
     },
     {
-      "name": "libclat_test"
-    },
-    {
       "name": "traffic_controller_unit_test",
       "keywords": ["netd-device-kernel-4.9", "netd-device-kernel-4.14"]
     },
     {
-      "name": "libnetworkstats_test"
-    },
-    {
       "name": "FrameworksNetDeflakeTest"
     }
   ],
@@ -174,23 +171,6 @@
       ]
     }
   ],
-  "auto-postsubmit": [
-    // Test tag for automotive targets. These are only running in postsubmit so as to harden the
-    // automotive targets to avoid introducing additional test flake and build time. The plan for
-    // presubmit testing for auto is to augment the existing tests to cover auto use cases as well.
-    // Additionally, this tag is used in targeted test suites to limit resource usage on the test
-    // infra during the hardening phase.
-    // TODO: this tag to be removed once the above is no longer an issue.
-    {
-      "name": "FrameworksNetTests"
-    },
-    {
-      "name": "FrameworksNetIntegrationTests"
-    },
-    {
-      "name": "FrameworksNetDeflakeTest"
-    }
-  ],
   "imports": [
     {
       "path": "frameworks/base/core/java/android/net"
diff --git a/Tethering/Android.bp b/Tethering/Android.bp
index 2c7b868..26eef96 100644
--- a/Tethering/Android.bp
+++ b/Tethering/Android.bp
@@ -31,11 +31,12 @@
         "apishim/**/*.java",
         "src/**/*.java",
         ":framework-connectivity-shared-srcs",
-        ":tethering-module-utils-srcs",
         ":services-tethering-shared-srcs",
+        ":statslog-tethering-java-gen",
     ],
     static_libs: [
         "androidx.annotation_annotation",
+        "connectivity-net-module-utils-bpf",
         "modules-utils-build",
         "modules-utils-statemachine",
         "networkstack-client",
@@ -45,6 +46,7 @@
         "net-utils-framework-common",
         "net-utils-device-common",
         "net-utils-device-common-bpf",
+        "net-utils-device-common-ip",
         "net-utils-device-common-netlink",
         "netd-client",
         "tetheringstatsprotos",
@@ -133,7 +135,7 @@
         "-Wthread-safety",
     ],
 
-    ldflags: ["-Wl,--exclude-libs=ALL,-error-limit=0"],
+    ldflags: ["-Wl,--exclude-libs=ALL,--error-limit=0"],
 }
 
 // Common defaults for compiling the actual APK.
@@ -223,3 +225,11 @@
     apex_available: ["com.android.tethering"],
     min_sdk_version: "30",
 }
+
+genrule {
+    name: "statslog-tethering-java-gen",
+    tools: ["stats-log-api-gen"],
+    cmd: "$(location stats-log-api-gen) --java $(out) --module network_tethering" +
+         " --javaPackage com.android.networkstack.tethering.metrics --javaClass TetheringStatsLog",
+    out: ["com/android/networkstack/tethering/metrics/TetheringStatsLog.java"],
+}
diff --git a/Tethering/apex/manifest.json b/Tethering/apex/manifest.json
index 3cb03ed..5d5ede6 100644
--- a/Tethering/apex/manifest.json
+++ b/Tethering/apex/manifest.json
@@ -1,4 +1,7 @@
 {
   "name": "com.android.tethering",
-  "version": 339990000
+
+  // Placeholder module version to be replaced during build.
+  // Do not change!
+  "version": 0
 }
diff --git a/Tethering/apishim/30/com/android/networkstack/tethering/apishim/api30/BpfCoordinatorShimImpl.java b/Tethering/apishim/30/com/android/networkstack/tethering/apishim/api30/BpfCoordinatorShimImpl.java
index b865a8e..18ef631 100644
--- a/Tethering/apishim/30/com/android/networkstack/tethering/apishim/api30/BpfCoordinatorShimImpl.java
+++ b/Tethering/apishim/30/com/android/networkstack/tethering/apishim/api30/BpfCoordinatorShimImpl.java
@@ -19,7 +19,6 @@
 import android.net.INetd;
 import android.net.MacAddress;
 import android.net.TetherStatsParcel;
-import android.net.util.SharedLog;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
 import android.util.SparseArray;
@@ -28,6 +27,7 @@
 import androidx.annotation.Nullable;
 
 import com.android.net.module.util.IBpfMap.ThrowingBiConsumer;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsValue;
diff --git a/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java b/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
index 0683e5e..fd9dab5 100644
--- a/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
+++ b/Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
@@ -19,7 +19,6 @@
 import static android.net.netstats.provider.NetworkStatsProvider.QUOTA_UNLIMITED;
 
 import android.net.MacAddress;
-import android.net.util.SharedLog;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.OsConstants;
@@ -31,6 +30,7 @@
 
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.IBpfMap.ThrowingBiConsumer;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsKey;
diff --git a/Tethering/common/TetheringLib/src/android/net/ITetheringEventCallback.aidl b/Tethering/common/TetheringLib/src/android/net/ITetheringEventCallback.aidl
index 836761f..b4e3ba4 100644
--- a/Tethering/common/TetheringLib/src/android/net/ITetheringEventCallback.aidl
+++ b/Tethering/common/TetheringLib/src/android/net/ITetheringEventCallback.aidl
@@ -36,5 +36,4 @@
     void onTetherStatesChanged(in TetherStatesParcel states);
     void onTetherClientsChanged(in List<TetheredClient> clients);
     void onOffloadStatusChanged(int status);
-    void onSupportedTetheringTypes(long supportedBitmap);
 }
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheringCallbackStartedParcel.aidl b/Tethering/common/TetheringLib/src/android/net/TetheringCallbackStartedParcel.aidl
index f33f846..253eacb 100644
--- a/Tethering/common/TetheringLib/src/android/net/TetheringCallbackStartedParcel.aidl
+++ b/Tethering/common/TetheringLib/src/android/net/TetheringCallbackStartedParcel.aidl
@@ -26,7 +26,7 @@
  * @hide
  */
 parcelable TetheringCallbackStartedParcel {
-    long supportedTypes;
+    boolean tetheringSupported;
     Network upstreamNetwork;
     TetheringConfigurationParcel config;
     TetherStatesParcel states;
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
index b3f0cf2..6f9b33e 100644
--- a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
+++ b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
@@ -183,12 +183,6 @@
      */
     public static final int TETHERING_WIGIG = 6;
 
-    /**
-     * The int value of last tethering type.
-     * @hide
-     */
-    public static final int MAX_TETHERING_TYPE = TETHERING_WIGIG;
-
     /** @hide */
     @Retention(RetentionPolicy.SOURCE)
     @IntDef(value = {
@@ -526,9 +520,6 @@
         }
 
         @Override
-        public void onSupportedTetheringTypes(long supportedBitmap) { }
-
-        @Override
         public void onUpstreamChanged(Network network) { }
 
         @Override
@@ -1042,29 +1033,15 @@
         /**
          * Called when tethering supported status changed.
          *
-         * <p>This callback will be called immediately after the callback is
-         * registered, and never be called if there is changes afterward.
-         *
-         * <p>Tethering may be disabled via system properties, device configuration, or device
-         * policy restrictions.
-         *
-         * @param supported whether any tethering type is supported.
-         */
-        default void onTetheringSupported(boolean supported) {}
-
-        /**
-         * Called when tethering supported status changed.
-         *
          * <p>This will be called immediately after the callback is registered, and may be called
          * multiple times later upon changes.
          *
          * <p>Tethering may be disabled via system properties, device configuration, or device
          * policy restrictions.
          *
-         * @param supportedTypes a set of @TetheringType which is supported.
-         * @hide
+         * @param supported The new supported status
          */
-        default void onSupportedTetheringTypes(@NonNull Set<Integer> supportedTypes) {}
+        default void onTetheringSupported(boolean supported) {}
 
         /**
          * Called when tethering upstream changed.
@@ -1362,8 +1339,7 @@
                 @Override
                 public void onCallbackStarted(TetheringCallbackStartedParcel parcel) {
                     executor.execute(() -> {
-                        callback.onSupportedTetheringTypes(unpackBits(parcel.supportedTypes));
-                        callback.onTetheringSupported(parcel.supportedTypes != 0);
+                        callback.onTetheringSupported(parcel.tetheringSupported);
                         callback.onUpstreamChanged(parcel.upstreamNetwork);
                         sendErrorCallbacks(parcel.states);
                         sendRegexpsChanged(parcel.config);
@@ -1382,13 +1358,6 @@
                     });
                 }
 
-                @Override
-                public void onSupportedTetheringTypes(long supportedBitmap) {
-                    executor.execute(() -> {
-                        callback.onSupportedTetheringTypes(unpackBits(supportedBitmap));
-                    });
-                }
-
                 private void sendRegexpsChanged(TetheringConfigurationParcel parcel) {
                     callback.onTetherableInterfaceRegexpsChanged(new TetheringInterfaceRegexps(
                             parcel.tetherableBluetoothRegexs,
@@ -1427,23 +1396,6 @@
     }
 
     /**
-     * Unpack bitmap to a set of bit position intergers.
-     * @hide
-     */
-    public static ArraySet<Integer> unpackBits(long val) {
-        final ArraySet<Integer> result = new ArraySet<>(Long.bitCount(val));
-        int bitPos = 0;
-        while (val != 0) {
-            if ((val & 1) == 1) result.add(bitPos);
-
-            val = val >>> 1;
-            bitPos++;
-        }
-
-        return result;
-    }
-
-    /**
      * Remove tethering event callback previously registered with
      * {@link #registerTetheringEventCallback}.
      *
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index c718f4c..438b592 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -44,9 +44,7 @@
 import android.net.dhcp.DhcpServingParamsParcelExt;
 import android.net.dhcp.IDhcpEventCallbacks;
 import android.net.dhcp.IDhcpServer;
-import android.net.ip.IpNeighborMonitor.NeighborEvent;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
@@ -64,11 +62,16 @@
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetdUtils;
+import com.android.net.module.util.SharedLog;
+import com.android.net.module.util.ip.InterfaceController;
+import com.android.net.module.util.ip.IpNeighborMonitor;
+import com.android.net.module.util.ip.IpNeighborMonitor.NeighborEvent;
 import com.android.networkstack.tethering.BpfCoordinator;
 import com.android.networkstack.tethering.BpfCoordinator.ClientInfo;
 import com.android.networkstack.tethering.BpfCoordinator.Ipv6ForwardingRule;
 import com.android.networkstack.tethering.PrivateAddressCoordinator;
 import com.android.networkstack.tethering.TetheringConfiguration;
+import com.android.networkstack.tethering.metrics.TetheringMetrics;
 import com.android.networkstack.tethering.util.InterfaceSet;
 import com.android.networkstack.tethering.util.PrefixUtils;
 
@@ -282,13 +285,15 @@
 
     private LinkAddress mIpv4Address;
 
+    private final TetheringMetrics mTetheringMetrics;
+
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
     public IpServer(
             String ifaceName, Looper looper, int interfaceType, SharedLog log,
             INetd netd, @NonNull BpfCoordinator coordinator, Callback callback,
             TetheringConfiguration config, PrivateAddressCoordinator addressCoordinator,
-            Dependencies deps) {
+            TetheringMetrics tetheringMetrics, Dependencies deps) {
         super(ifaceName, looper);
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
@@ -303,6 +308,7 @@
         mP2pLeasesSubnetPrefixLength = config.getP2pLeasesSubnetPrefixLength();
         mPrivateAddressCoordinator = addressCoordinator;
         mDeps = deps;
+        mTetheringMetrics = tetheringMetrics;
         resetLinkProperties();
         mLastError = TetheringManager.TETHER_ERROR_NO_ERROR;
         mServingMode = STATE_AVAILABLE;
@@ -1201,6 +1207,9 @@
             stopConntrackMonitoring();
 
             resetLinkProperties();
+
+            mTetheringMetrics.updateErrorCode(mInterfaceType, mLastError);
+            mTetheringMetrics.sendReport(mInterfaceType);
         }
 
         @Override
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index c403548..49442a6 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -23,11 +23,11 @@
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkStats.UID_TETHERING;
-import static android.net.ip.ConntrackMonitor.ConntrackEvent;
 import static android.net.netstats.provider.NetworkStatsProvider.QUOTA_UNLIMITED;
 import static android.system.OsConstants.ETH_P_IP;
 import static android.system.OsConstants.ETH_P_IPV6;
 
+import static com.android.net.module.util.ip.ConntrackMonitor.ConntrackEvent;
 import static com.android.networkstack.tethering.BpfUtils.DOWNSTREAM;
 import static com.android.networkstack.tethering.BpfUtils.UPSTREAM;
 import static com.android.networkstack.tethering.TetheringConfiguration.DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS;
@@ -40,18 +40,14 @@
 import android.net.NetworkStats;
 import android.net.NetworkStats.Entry;
 import android.net.TetherOffloadRuleParcel;
-import android.net.ip.ConntrackMonitor;
-import android.net.ip.ConntrackMonitor.ConntrackEventConsumer;
 import android.net.ip.IpServer;
 import android.net.netstats.provider.NetworkStatsProvider;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.SystemClock;
 import android.system.ErrnoException;
 import android.system.OsConstants;
 import android.text.TextUtils;
 import android.util.ArraySet;
-import android.util.Base64;
 import android.util.Log;
 import android.util.SparseArray;
 
@@ -61,16 +57,20 @@
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.BpfDump;
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetworkStackConstants;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.Struct;
 import com.android.net.module.util.Struct.U32;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsKey;
 import com.android.net.module.util.bpf.TetherStatsValue;
+import com.android.net.module.util.ip.ConntrackMonitor;
+import com.android.net.module.util.ip.ConntrackMonitor.ConntrackEventConsumer;
 import com.android.net.module.util.netlink.ConntrackMessage;
 import com.android.net.module.util.netlink.NetlinkConstants;
 import com.android.net.module.util.netlink.NetlinkSocket;
@@ -125,9 +125,6 @@
     private static final String DUMPSYS_RAWMAP_ARG_STATS = "--stats";
     private static final String DUMPSYS_RAWMAP_ARG_UPSTREAM4 = "--upstream4";
 
-    // Using "," as a separator is safe because base64 characters are [0-9a-zA-Z/=+].
-    private static final String DUMP_BASE64_DELIMITER = ",";
-
     /** The names of all the BPF counters defined in bpf_tethering.h. */
     public static final String[] sBpfCounterNames = getBpfCounterNames();
 
@@ -944,6 +941,8 @@
      * be allowed to be accessed on the handler thread.
      */
     public void dump(@NonNull IndentingPrintWriter pw) {
+        // Note that EthernetTetheringTest#isTetherConfigBpfOffloadEnabled relies on
+        // "mIsBpfEnabled" to check tethering config via dumpsys. Beware of the change if any.
         pw.println("mIsBpfEnabled: " + mIsBpfEnabled);
         pw.println("Polling " + (mPollingStarted ? "started" : "not started"));
         pw.println("Stats provider " + (mStatsProvider != null
@@ -1078,18 +1077,6 @@
         }
     }
 
-    private <K extends Struct, V extends Struct> String bpfMapEntryToBase64String(
-            final K key, final V value) {
-        final byte[] keyBytes = key.writeToBytes();
-        final String keyBase64Str = Base64.encodeToString(keyBytes, Base64.DEFAULT)
-                .replace("\n", "");
-        final byte[] valueBytes = value.writeToBytes();
-        final String valueBase64Str = Base64.encodeToString(valueBytes, Base64.DEFAULT)
-                .replace("\n", "");
-
-        return keyBase64Str + DUMP_BASE64_DELIMITER + valueBase64Str;
-    }
-
     private <K extends Struct, V extends Struct> void dumpRawMap(BpfMap<K, V> map,
             IndentingPrintWriter pw) throws ErrnoException {
         if (map == null) {
@@ -1100,14 +1087,20 @@
             pw.println("No entries");
             return;
         }
-        map.forEach((k, v) -> pw.println(bpfMapEntryToBase64String(k, v)));
+        map.forEach((k, v) -> pw.println(BpfDump.toBase64EncodedString(k, v)));
     }
 
     /**
-     * Dump raw BPF map in base64 encoded strings. For test only.
-     * Only allow to dump one map path once.
-     * Format:
+     * Dump raw BPF map into the base64 encoded strings "<base64 key>,<base64 value>".
+     * Allow to dump only one map path once. For test only.
+     *
+     * Usage:
      * $ dumpsys tethering bpfRawMap --<map name>
+     *
+     * Output:
+     * <base64 encoded key #1>,<base64 encoded value #1>
+     * <base64 encoded key #2>,<base64 encoded value #2>
+     * ..
      */
     public void dumpRawMap(@NonNull IndentingPrintWriter pw, @Nullable String[] args) {
         // TODO: consider checking the arg order that <map name> is after "bpfRawMap". Probably
diff --git a/Tethering/src/com/android/networkstack/tethering/EntitlementManager.java b/Tethering/src/com/android/networkstack/tethering/EntitlementManager.java
index adc95ab..741af5c 100644
--- a/Tethering/src/com/android/networkstack/tethering/EntitlementManager.java
+++ b/Tethering/src/com/android/networkstack/tethering/EntitlementManager.java
@@ -43,7 +43,6 @@
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.pm.PackageManager;
-import android.net.util.SharedLog;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Parcel;
@@ -55,6 +54,7 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.SharedLog;
 
 import java.io.PrintWriter;
 import java.util.BitSet;
diff --git a/Tethering/src/com/android/networkstack/tethering/IPv6TetheringCoordinator.java b/Tethering/src/com/android/networkstack/tethering/IPv6TetheringCoordinator.java
index f3dcaa2..ab3929d 100644
--- a/Tethering/src/com/android/networkstack/tethering/IPv6TetheringCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/IPv6TetheringCoordinator.java
@@ -24,9 +24,10 @@
 import android.net.RouteInfo;
 import android.net.ip.IpServer;
 import android.net.util.NetworkConstants;
-import android.net.util.SharedLog;
 import android.util.Log;
 
+import com.android.net.module.util.SharedLog;
+
 import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
diff --git a/Tethering/src/com/android/networkstack/tethering/OffloadController.java b/Tethering/src/com/android/networkstack/tethering/OffloadController.java
index d60c21d..94684af 100644
--- a/Tethering/src/com/android/networkstack/tethering/OffloadController.java
+++ b/Tethering/src/com/android/networkstack/tethering/OffloadController.java
@@ -43,7 +43,6 @@
 import android.net.NetworkStats.Entry;
 import android.net.RouteInfo;
 import android.net.netstats.provider.NetworkStatsProvider;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.provider.Settings;
 import android.system.ErrnoException;
@@ -53,6 +52,7 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.IndentingPrintWriter;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.netlink.ConntrackMessage;
 import com.android.net.module.util.netlink.NetlinkConstants;
 import com.android.net.module.util.netlink.NetlinkSocket;
diff --git a/Tethering/src/com/android/networkstack/tethering/OffloadHardwareInterface.java b/Tethering/src/com/android/networkstack/tethering/OffloadHardwareInterface.java
index 9da66d8..fbb342d 100644
--- a/Tethering/src/com/android/networkstack/tethering/OffloadHardwareInterface.java
+++ b/Tethering/src/com/android/networkstack/tethering/OffloadHardwareInterface.java
@@ -28,7 +28,6 @@
 import android.hardware.tetheroffload.control.V1_0.NetworkProtocol;
 import android.hardware.tetheroffload.control.V1_0.OffloadCallbackEvent;
 import android.hardware.tetheroffload.control.V1_1.ITetheringOffloadCallback;
-import android.net.util.SharedLog;
 import android.net.util.SocketUtils;
 import android.os.Handler;
 import android.os.NativeHandle;
@@ -40,6 +39,7 @@
 import android.util.Pair;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.netlink.NetlinkSocket;
 import com.android.net.module.util.netlink.StructNfGenMsg;
 import com.android.net.module.util.netlink.StructNlMsgHdr;
diff --git a/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java b/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
index cc2422f..41a10ae 100644
--- a/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
@@ -172,6 +172,9 @@
             return new LinkAddress(LEGACY_WIFI_P2P_IFACE_ADDRESS);
         }
 
+        // This ensures that tethering isn't started on 2 different interfaces with the same type.
+        // Once tethering could support multiple interface with the same type,
+        // TetheringSoftApCallback would need to handle it among others.
         final LinkAddress cachedAddress = mCachedAddresses.get(ipServer.interfaceType());
         if (useLastAddress && cachedAddress != null
                 && !isConflictWithUpstream(asIpPrefix(cachedAddress))) {
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index 35a394d..89ed620 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -98,8 +98,6 @@
 import android.net.TetheringManager.TetheringRequest;
 import android.net.TetheringRequestParcel;
 import android.net.ip.IpServer;
-import android.net.shared.NetdUtils;
-import android.net.util.SharedLog;
 import android.net.wifi.WifiClient;
 import android.net.wifi.WifiManager;
 import android.net.wifi.p2p.WifiP2pGroup;
@@ -136,10 +134,13 @@
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
 import com.android.net.module.util.CollectionUtils;
+import com.android.net.module.util.NetdUtils;
+import com.android.net.module.util.SharedLog;
 import com.android.networkstack.apishim.common.BluetoothPanShim;
 import com.android.networkstack.apishim.common.BluetoothPanShim.TetheredInterfaceCallbackShim;
 import com.android.networkstack.apishim.common.BluetoothPanShim.TetheredInterfaceRequestShim;
 import com.android.networkstack.apishim.common.UnsupportedApiLevelException;
+import com.android.networkstack.tethering.metrics.TetheringMetrics;
 import com.android.networkstack.tethering.util.InterfaceSet;
 import com.android.networkstack.tethering.util.PrefixUtils;
 import com.android.networkstack.tethering.util.TetheringUtils;
@@ -254,6 +255,7 @@
     private final UserManager mUserManager;
     private final BpfCoordinator mBpfCoordinator;
     private final PrivateAddressCoordinator mPrivateAddressCoordinator;
+    private final TetheringMetrics mTetheringMetrics;
     private int mActiveDataSubId = INVALID_SUBSCRIPTION_ID;
 
     private volatile TetheringConfiguration mConfig;
@@ -279,11 +281,6 @@
     private BluetoothPan mBluetoothPan;
     private PanServiceListener mBluetoothPanListener;
     private ArrayList<Pair<Boolean, IIntResultListener>> mPendingPanRequests;
-    // AIDL doesn't support Set<Integer>. Maintain a int bitmap here. When the bitmap is passed to
-    // TetheringManager, TetheringManager would convert it to a set of Integer types.
-    // mSupportedTypeBitmap should always be updated inside tethering internal thread but it may be
-    // read from binder thread which called TetheringService directly.
-    private volatile long mSupportedTypeBitmap;
 
     public Tethering(TetheringDependencies deps) {
         mLog.mark("Tethering.constructed");
@@ -292,6 +289,7 @@
         mNetd = mDeps.getINetd(mContext);
         mLooper = mDeps.getTetheringLooper();
         mNotificationUpdater = mDeps.getNotificationUpdater(mContext, mLooper);
+        mTetheringMetrics = mDeps.getTetheringMetrics();
 
         // This is intended to ensrure that if something calls startTethering(bluetooth) just after
         // bluetooth is enabled. Before onServiceConnected is called, store the calls into this
@@ -445,8 +443,22 @@
                 mStateReceiver, noUpstreamFilter, PERMISSION_MAINLINE_NETWORK_STACK, mHandler);
 
         final WifiManager wifiManager = getWifiManager();
+        TetheringSoftApCallback softApCallback = new TetheringSoftApCallback();
         if (wifiManager != null) {
-            wifiManager.registerSoftApCallback(mExecutor, new TetheringSoftApCallback());
+            wifiManager.registerSoftApCallback(mExecutor, softApCallback);
+        }
+        if (SdkLevel.isAtLeastT() && wifiManager != null) {
+            try {
+                // Although WifiManager#registerLocalOnlyHotspotSoftApCallback document that it need
+                // NEARBY_WIFI_DEVICES permission, but actually a caller who have NETWORK_STACK
+                // or MAINLINE_NETWORK_STACK permission would also able to use this API.
+                wifiManager.registerLocalOnlyHotspotSoftApCallback(mExecutor, softApCallback);
+            } catch (UnsupportedOperationException e) {
+                // Since wifi module development in internal branch,
+                // #registerLocalOnlyHotspotSoftApCallback currently doesn't supported in AOSP
+                // before AOSP switch to Android T + 1.
+                Log.wtf(TAG, "registerLocalOnlyHotspotSoftApCallback API is not supported");
+            }
         }
 
         startTrackDefaultNetwork();
@@ -500,8 +512,6 @@
         mUpstreamNetworkMonitor.setUpstreamConfig(mConfig.chooseUpstreamAutomatically,
                 mConfig.isDunRequired);
         reportConfigurationChanged(mConfig.toStableParcelable());
-
-        updateSupportedDownstreams(mConfig);
     }
 
     private void maybeDunSettingChanged() {
@@ -542,6 +552,13 @@
         }
 
         // Called by wifi when the number of soft AP clients changed.
+        // Currently multiple softAp would not behave well in PrivateAddressCoordinator
+        // (where it gets the address from cache), it ensure tethering only support one ipServer for
+        // TETHERING_WIFI. Once tethering support multiple softAp enabled simultaneously,
+        // onConnectedClientsChanged should also be updated to support tracking different softAp's
+        // clients individually.
+        // TODO: Add wtf log and have check to reject request duplicated type with different
+        // interface.
         @Override
         public void onConnectedClientsChanged(final List<WifiClient> clients) {
             updateConnectedClients(clients);
@@ -616,7 +633,8 @@
         processInterfaceStateChange(iface, false /* enabled */);
     }
 
-    void startTethering(final TetheringRequestParcel request, final IIntResultListener listener) {
+    void startTethering(final TetheringRequestParcel request, final String callerPkg,
+            final IIntResultListener listener) {
         mHandler.post(() -> {
             final TetheringRequestParcel unfinishedRequest = mActiveTetheringRequests.get(
                     request.tetheringType);
@@ -636,6 +654,7 @@
                         request.showProvisioningUi);
             }
             enableTetheringInternal(request.tetheringType, true /* enabled */, listener);
+            mTetheringMetrics.createBuilder(request.tetheringType, callerPkg);
         });
     }
 
@@ -695,7 +714,11 @@
 
         // If changing tethering fail, remove corresponding request
         // no matter who trigger the start/stop.
-        if (result != TETHER_ERROR_NO_ERROR) mActiveTetheringRequests.remove(type);
+        if (result != TETHER_ERROR_NO_ERROR) {
+            mActiveTetheringRequests.remove(type);
+            mTetheringMetrics.updateErrorCode(type, result);
+            mTetheringMetrics.sendReport(type);
+        }
     }
 
     private int setWifiTethering(final boolean enable) {
@@ -1376,7 +1399,9 @@
     private void enableIpServing(int tetheringType, String ifname, int ipServingMode,
             boolean isNcm) {
         ensureIpServerStarted(ifname, tetheringType, isNcm);
-        changeInterfaceState(ifname, ipServingMode);
+        if (tether(ifname, ipServingMode) != TETHER_ERROR_NO_ERROR) {
+            Log.e(TAG, "unable start tethering on iface " + ifname);
+        }
     }
 
     private void disableWifiIpServingCommon(int tetheringType, String ifname) {
@@ -1521,31 +1546,30 @@
         }
     }
 
-    private void changeInterfaceState(String ifname, int requestedState) {
-        final int result;
-        switch (requestedState) {
-            case IpServer.STATE_UNAVAILABLE:
-            case IpServer.STATE_AVAILABLE:
-                result = untether(ifname);
-                break;
-            case IpServer.STATE_TETHERED:
-            case IpServer.STATE_LOCAL_ONLY:
-                result = tether(ifname, requestedState);
-                break;
-            default:
-                Log.wtf(TAG, "Unknown interface state: " + requestedState);
-                return;
-        }
-        if (result != TETHER_ERROR_NO_ERROR) {
-            Log.e(TAG, "unable start or stop tethering on iface " + ifname);
-            return;
-        }
-    }
-
     TetheringConfiguration getTetheringConfiguration() {
         return mConfig;
     }
 
+    boolean hasAnySupportedDownstream() {
+        if ((mConfig.tetherableUsbRegexs.length != 0)
+                || (mConfig.tetherableWifiRegexs.length != 0)
+                || (mConfig.tetherableBluetoothRegexs.length != 0)) {
+            return true;
+        }
+
+        // Before T, isTetheringSupported would return true if wifi, usb and bluetooth tethering are
+        // disabled (whole tethering settings would be hidden). This means tethering would also not
+        // support wifi p2p, ethernet tethering and mirrorlink. This is wrong but probably there are
+        // some devices in the field rely on this to disable tethering entirely.
+        if (!SdkLevel.isAtLeastT()) return false;
+
+        return (mConfig.tetherableWifiP2pRegexs.length != 0)
+                || (mConfig.tetherableNcmRegexs.length != 0)
+                || isEthernetSupported();
+    }
+
+    // TODO: using EtherentManager new API to check whether ethernet is supported when the API is
+    // ready to use.
     private boolean isEthernetSupported() {
         return mContext.getSystemService(Context.ETHERNET_SERVICE) != null;
     }
@@ -2335,7 +2359,7 @@
         mHandler.post(() -> {
             mTetheringEventCallbacks.register(callback, new CallbackCookie(hasListPermission));
             final TetheringCallbackStartedParcel parcel = new TetheringCallbackStartedParcel();
-            parcel.supportedTypes = mSupportedTypeBitmap;
+            parcel.tetheringSupported = isTetheringSupported();
             parcel.upstreamNetwork = mTetherUpstream;
             parcel.config = mConfig.toStableParcelable();
             parcel.states =
@@ -2374,22 +2398,6 @@
         });
     }
 
-    private void reportTetheringSupportedChange(final long supportedBitmap) {
-        final int length = mTetheringEventCallbacks.beginBroadcast();
-        try {
-            for (int i = 0; i < length; i++) {
-                try {
-                    mTetheringEventCallbacks.getBroadcastItem(i).onSupportedTetheringTypes(
-                            supportedBitmap);
-                } catch (RemoteException e) {
-                    // Not really very much to do here.
-                }
-            }
-        } finally {
-            mTetheringEventCallbacks.finishBroadcast();
-        }
-    }
-
     private void reportUpstreamChanged(UpstreamNetworkState ns) {
         final int length = mTetheringEventCallbacks.beginBroadcast();
         final Network network = (ns != null) ? ns.network : null;
@@ -2474,56 +2482,18 @@
         }
     }
 
-    private void updateSupportedDownstreams(final TetheringConfiguration config) {
-        final long preSupportedBitmap = mSupportedTypeBitmap;
-
-        if (!isTetheringAllowed() || mEntitlementMgr.isProvisioningNeededButUnavailable()) {
-            mSupportedTypeBitmap = 0;
-        } else {
-            mSupportedTypeBitmap = makeSupportedDownstreams(config);
-        }
-
-        if (preSupportedBitmap != mSupportedTypeBitmap) {
-            reportTetheringSupportedChange(mSupportedTypeBitmap);
-        }
-    }
-
-    private long makeSupportedDownstreams(final TetheringConfiguration config) {
-        long types = 0;
-        if (config.tetherableUsbRegexs.length != 0) types |= (1 << TETHERING_USB);
-
-        if (config.tetherableWifiRegexs.length != 0) types |= (1 << TETHERING_WIFI);
-
-        if (config.tetherableBluetoothRegexs.length != 0) types |= (1 << TETHERING_BLUETOOTH);
-
-        // Before T, isTetheringSupported would return true if wifi, usb and bluetooth tethering are
-        // disabled (whole tethering settings would be hidden). This means tethering would also not
-        // support wifi p2p, ethernet tethering and mirrorlink. This is wrong but probably there are
-        // some devices in the field rely on this to disable tethering entirely.
-        if (!SdkLevel.isAtLeastT() && types == 0) return types;
-
-        if (config.tetherableNcmRegexs.length != 0) types |= (1 << TETHERING_NCM);
-
-        if (config.tetherableWifiP2pRegexs.length != 0) types |= (1 << TETHERING_WIFI_P2P);
-
-        if (isEthernetSupported()) types |= (1 << TETHERING_ETHERNET);
-
-        return types;
-    }
-
     // if ro.tether.denied = true we default to no tethering
     // gservices could set the secure setting to 1 though to enable it on a build where it
     // had previously been turned off.
-    private boolean isTetheringAllowed() {
+    boolean isTetheringSupported() {
         final int defaultVal = mDeps.isTetheringDenied() ? 0 : 1;
         final boolean tetherSupported = Settings.Global.getInt(mContext.getContentResolver(),
                 Settings.Global.TETHER_SUPPORTED, defaultVal) != 0;
-        return tetherSupported
+        final boolean tetherEnabledInSettings = tetherSupported
                 && !mUserManager.hasUserRestriction(UserManager.DISALLOW_CONFIG_TETHERING);
-    }
 
-    boolean isTetheringSupported() {
-        return mSupportedTypeBitmap > 0;
+        return tetherEnabledInSettings && hasAnySupportedDownstream()
+                && !mEntitlementMgr.isProvisioningNeededButUnavailable();
     }
 
     private void dumpBpf(IndentingPrintWriter pw) {
@@ -2779,7 +2749,7 @@
         final TetherState tetherState = new TetherState(
                 new IpServer(iface, mLooper, interfaceType, mLog, mNetd, mBpfCoordinator,
                              makeControlCallback(), mConfig, mPrivateAddressCoordinator,
-                             mDeps.getIpServerDependencies()), isNcm);
+                             mTetheringMetrics, mDeps.getIpServerDependencies()), isNcm);
         mTetherStates.put(iface, tetherState);
         tetherState.ipServer.start();
     }
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 7c36054..696a970 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -30,7 +30,6 @@
 import android.content.Context;
 import android.content.res.Resources;
 import android.net.TetheringConfigurationParcel;
-import android.net.util.SharedLog;
 import android.os.PersistableBundle;
 import android.provider.DeviceConfig;
 import android.provider.Settings;
@@ -42,6 +41,7 @@
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.DeviceConfigUtils;
+import com.android.net.module.util.SharedLog;
 
 import java.io.PrintWriter;
 import java.util.ArrayList;
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java b/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
index 9224213..611d1cf 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
@@ -22,7 +22,6 @@
 import android.content.Context;
 import android.net.INetd;
 import android.net.ip.IpServer;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
@@ -32,8 +31,10 @@
 import androidx.annotation.NonNull;
 
 import com.android.internal.util.StateMachine;
+import com.android.net.module.util.SharedLog;
 import com.android.networkstack.apishim.BluetoothPanShimImpl;
 import com.android.networkstack.apishim.common.BluetoothPanShim;
+import com.android.networkstack.tethering.metrics.TetheringMetrics;
 
 import java.util.ArrayList;
 
@@ -163,4 +164,11 @@
     public BluetoothPanShim getBluetoothPanShim(BluetoothPan pan) {
         return BluetoothPanShimImpl.newInstance(pan);
     }
+
+    /**
+     * Get a reference to the TetheringMetrics to be used by tethering.
+     */
+    public TetheringMetrics getTetheringMetrics() {
+        return new TetheringMetrics();
+    }
 }
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringService.java b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
index 9fb61fe..f147e10 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringService.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
@@ -137,7 +137,7 @@
                 return;
             }
 
-            mTethering.startTethering(request, listener);
+            mTethering.startTethering(request, callerPkg, listener);
         }
 
         @Override
diff --git a/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java b/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
index f8dd673..16c031b 100644
--- a/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
+++ b/Tethering/src/com/android/networkstack/tethering/UpstreamNetworkMonitor.java
@@ -36,7 +36,6 @@
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.util.Log;
 import android.util.SparseIntArray;
@@ -46,6 +45,7 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.StateMachine;
+import com.android.net.module.util.SharedLog;
 import com.android.networkstack.apishim.ConnectivityManagerShimImpl;
 import com.android.networkstack.apishim.common.ConnectivityManagerShim;
 import com.android.networkstack.tethering.util.PrefixUtils;
diff --git a/Tethering/src/com/android/networkstack/tethering/metrics/TetheringMetrics.java b/Tethering/src/com/android/networkstack/tethering/metrics/TetheringMetrics.java
new file mode 100644
index 0000000..d8e631e
--- /dev/null
+++ b/Tethering/src/com/android/networkstack/tethering/metrics/TetheringMetrics.java
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.networkstack.tethering.metrics;
+
+import static android.net.TetheringManager.TETHERING_BLUETOOTH;
+import static android.net.TetheringManager.TETHERING_ETHERNET;
+import static android.net.TetheringManager.TETHERING_NCM;
+import static android.net.TetheringManager.TETHERING_USB;
+import static android.net.TetheringManager.TETHERING_WIFI;
+import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+import static android.net.TetheringManager.TETHER_ERROR_DHCPSERVER_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_DISABLE_FORWARDING_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_ENABLE_FORWARDING_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_ENTITLEMENT_UNKNOWN;
+import static android.net.TetheringManager.TETHER_ERROR_IFACE_CFG_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_INTERNAL_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION;
+import static android.net.TetheringManager.TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION;
+import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_PROVISIONING_FAILED;
+import static android.net.TetheringManager.TETHER_ERROR_SERVICE_UNAVAIL;
+import static android.net.TetheringManager.TETHER_ERROR_TETHER_IFACE_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_UNAVAIL_IFACE;
+import static android.net.TetheringManager.TETHER_ERROR_UNKNOWN_IFACE;
+import static android.net.TetheringManager.TETHER_ERROR_UNSUPPORTED;
+import static android.net.TetheringManager.TETHER_ERROR_UNTETHER_IFACE_ERROR;
+
+import android.stats.connectivity.DownstreamType;
+import android.stats.connectivity.ErrorCode;
+import android.stats.connectivity.UpstreamType;
+import android.stats.connectivity.UserType;
+import android.util.Log;
+import android.util.SparseArray;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+
+/**
+ * Collection of utilities for tethering metrics.
+ *
+ * To see if the logs are properly sent to statsd, execute following commands
+ *
+ * $ adb shell cmd stats print-logs
+ * $ adb logcat | grep statsd OR $ adb logcat -b stats
+ *
+ * @hide
+ */
+public class TetheringMetrics {
+    private static final String TAG = TetheringMetrics.class.getSimpleName();
+    private static final boolean DBG = false;
+    private static final String SETTINGS_PKG_NAME = "com.android.settings";
+    private static final String SYSTEMUI_PKG_NAME = "com.android.systemui";
+    private static final String GMS_PKG_NAME = "com.google.android.gms";
+    private final SparseArray<NetworkTetheringReported.Builder> mBuilderMap = new SparseArray<>();
+
+    /** Update Tethering stats about caller's package name and downstream type. */
+    public void createBuilder(final int downstreamType, final String callerPkg) {
+        NetworkTetheringReported.Builder statsBuilder =
+                    NetworkTetheringReported.newBuilder();
+        statsBuilder.setDownstreamType(downstreamTypeToEnum(downstreamType))
+                    .setUserType(userTypeToEnum(callerPkg))
+                    .setUpstreamType(UpstreamType.UT_UNKNOWN)
+                    .setErrorCode(ErrorCode.EC_NO_ERROR)
+                    .build();
+        mBuilderMap.put(downstreamType, statsBuilder);
+    }
+
+    /** Update error code of given downstreamType. */
+    public void updateErrorCode(final int downstreamType, final int errCode) {
+        NetworkTetheringReported.Builder statsBuilder = mBuilderMap.get(downstreamType);
+        if (statsBuilder == null) {
+            Log.e(TAG, "Given downstreamType does not exist, this is a bug!");
+            return;
+        }
+        statsBuilder.setErrorCode(errorCodeToEnum(errCode));
+    }
+
+    /** Remove Tethering stats.
+     *  If Tethering stats is ready to write then write it before removing.
+     */
+    public void sendReport(final int downstreamType) {
+        final NetworkTetheringReported.Builder statsBuilder =
+                mBuilderMap.get(downstreamType);
+        if (statsBuilder == null) {
+            Log.e(TAG, "Given downstreamType does not exist, this is a bug!");
+            return;
+        }
+        write(statsBuilder.build());
+        mBuilderMap.remove(downstreamType);
+    }
+
+    /** Collect Tethering stats and write metrics data to statsd pipeline. */
+    @VisibleForTesting
+    public void write(@NonNull final NetworkTetheringReported reported) {
+        TetheringStatsLog.write(TetheringStatsLog.NETWORK_TETHERING_REPORTED,
+                reported.getErrorCode().getNumber(),
+                reported.getDownstreamType().getNumber(),
+                reported.getUpstreamType().getNumber(),
+                reported.getUserType().getNumber());
+        if (DBG) {
+            Log.d(TAG, "Write errorCode: " + reported.getErrorCode().getNumber()
+                    + ", downstreamType: " + reported.getDownstreamType().getNumber()
+                    + ", upstreamType: " + reported.getUpstreamType().getNumber()
+                    + ", userType: " + reported.getUserType().getNumber());
+        }
+    }
+
+    /** Map {@link TetheringType} to {@link DownstreamType} */
+    private DownstreamType downstreamTypeToEnum(final int ifaceType) {
+        switch(ifaceType) {
+            case TETHERING_WIFI:
+                return DownstreamType.DS_TETHERING_WIFI;
+            case TETHERING_WIFI_P2P:
+                return DownstreamType.DS_TETHERING_WIFI_P2P;
+            case TETHERING_USB:
+                return DownstreamType.DS_TETHERING_USB;
+            case TETHERING_BLUETOOTH:
+                return DownstreamType.DS_TETHERING_BLUETOOTH;
+            case TETHERING_NCM:
+                return DownstreamType.DS_TETHERING_NCM;
+            case TETHERING_ETHERNET:
+                return DownstreamType.DS_TETHERING_ETHERNET;
+            default:
+                return DownstreamType.DS_UNSPECIFIED;
+        }
+    }
+
+    /** Map {@link StartTetheringError} to {@link ErrorCode} */
+    private ErrorCode errorCodeToEnum(final int lastError) {
+        switch(lastError) {
+            case TETHER_ERROR_NO_ERROR:
+                return ErrorCode.EC_NO_ERROR;
+            case TETHER_ERROR_UNKNOWN_IFACE:
+                return ErrorCode.EC_UNKNOWN_IFACE;
+            case TETHER_ERROR_SERVICE_UNAVAIL:
+                return ErrorCode.EC_SERVICE_UNAVAIL;
+            case TETHER_ERROR_UNSUPPORTED:
+                return ErrorCode.EC_UNSUPPORTED;
+            case TETHER_ERROR_UNAVAIL_IFACE:
+                return ErrorCode.EC_UNAVAIL_IFACE;
+            case TETHER_ERROR_INTERNAL_ERROR:
+                return ErrorCode.EC_INTERNAL_ERROR;
+            case TETHER_ERROR_TETHER_IFACE_ERROR:
+                return ErrorCode.EC_TETHER_IFACE_ERROR;
+            case TETHER_ERROR_UNTETHER_IFACE_ERROR:
+                return ErrorCode.EC_UNTETHER_IFACE_ERROR;
+            case TETHER_ERROR_ENABLE_FORWARDING_ERROR:
+                return ErrorCode.EC_ENABLE_FORWARDING_ERROR;
+            case TETHER_ERROR_DISABLE_FORWARDING_ERROR:
+                return ErrorCode.EC_DISABLE_FORWARDING_ERROR;
+            case TETHER_ERROR_IFACE_CFG_ERROR:
+                return ErrorCode.EC_IFACE_CFG_ERROR;
+            case TETHER_ERROR_PROVISIONING_FAILED:
+                return ErrorCode.EC_PROVISIONING_FAILED;
+            case TETHER_ERROR_DHCPSERVER_ERROR:
+                return ErrorCode.EC_DHCPSERVER_ERROR;
+            case TETHER_ERROR_ENTITLEMENT_UNKNOWN:
+                return ErrorCode.EC_ENTITLEMENT_UNKNOWN;
+            case TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION:
+                return ErrorCode.EC_NO_CHANGE_TETHERING_PERMISSION;
+            case TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION:
+                return ErrorCode.EC_NO_ACCESS_TETHERING_PERMISSION;
+            default:
+                return ErrorCode.EC_UNKNOWN_TYPE;
+        }
+    }
+
+    /** Map callerPkg to {@link UserType} */
+    private UserType userTypeToEnum(final String callerPkg) {
+        if (callerPkg.equals(SETTINGS_PKG_NAME)) {
+            return UserType.USER_SETTINGS;
+        } else if (callerPkg.equals(SYSTEMUI_PKG_NAME)) {
+            return UserType.USER_SYSTEMUI;
+        } else if (callerPkg.equals(GMS_PKG_NAME)) {
+            return UserType.USER_GMS;
+        } else {
+            return UserType.USER_UNKNOWN;
+        }
+    }
+}
diff --git a/Tethering/tests/integration/Android.bp b/Tethering/tests/integration/Android.bp
index 31c3df3..ca8d3de 100644
--- a/Tethering/tests/integration/Android.bp
+++ b/Tethering/tests/integration/Android.bp
@@ -32,6 +32,7 @@
         "net-tests-utils",
         "net-utils-device-common-bpf",
         "testables",
+        "connectivity-net-module-utils-bpf",
     ],
     libs: [
         "android.test.runner",
diff --git a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
index 5869f2b..86dca1c 100644
--- a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
+++ b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
@@ -26,15 +26,19 @@
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_GLOBAL;
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_LOCAL;
 import static android.net.TetheringManager.TETHERING_ETHERNET;
-import static android.net.TetheringTester.RemoteResponder;
-import static android.system.OsConstants.IPPROTO_ICMPV6;
+import static android.net.TetheringTester.isExpectedIcmpv6Packet;
+import static android.net.TetheringTester.isExpectedUdpPacket;
 import static android.system.OsConstants.IPPROTO_IP;
+import static android.system.OsConstants.IPPROTO_IPV6;
 import static android.system.OsConstants.IPPROTO_UDP;
 
+import static com.android.net.module.util.BpfDump.BASE64_DELIMITER;
 import static com.android.net.module.util.ConnectivityUtils.isIPv6ULA;
 import static com.android.net.module.util.HexDump.dumpHexString;
 import static com.android.net.module.util.NetworkStackConstants.ETHER_TYPE_IPV4;
 import static com.android.net.module.util.NetworkStackConstants.ETHER_TYPE_IPV6;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ECHO_REPLY_TYPE;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ECHO_REQUEST_TYPE;
 import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ROUTER_ADVERTISEMENT;
 import static com.android.testutils.DeviceInfoUtils.KVersion;
 import static com.android.testutils.TestNetworkTrackerKt.initTestNetwork;
@@ -73,17 +77,14 @@
 import androidx.test.filters.MediumTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.net.module.util.Ipv6Utils;
 import com.android.net.module.util.PacketBuilder;
 import com.android.net.module.util.Struct;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsKey;
 import com.android.net.module.util.bpf.TetherStatsValue;
-import com.android.net.module.util.structs.EthernetHeader;
-import com.android.net.module.util.structs.Icmpv6Header;
-import com.android.net.module.util.structs.Ipv4Header;
 import com.android.net.module.util.structs.Ipv6Header;
-import com.android.net.module.util.structs.UdpHeader;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
@@ -101,6 +102,7 @@
 
 import java.io.FileDescriptor;
 import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.InterfaceAddress;
 import java.net.NetworkInterface;
@@ -140,20 +142,27 @@
     // Per TX UDP packet size: ethhdr (14) + iphdr (20) + udphdr (8) + payload (2) = 44 bytes.
     private static final int TX_UDP_PACKET_SIZE = 44;
     private static final int TX_UDP_PACKET_COUNT = 123;
+    private static final long WAIT_RA_TIMEOUT_MS = 2000;
 
     private static final LinkAddress TEST_IP4_ADDR = new LinkAddress("10.0.0.1/8");
     private static final LinkAddress TEST_IP6_ADDR = new LinkAddress("2001:db8:1::101/64");
     private static final InetAddress TEST_IP4_DNS = parseNumericAddress("8.8.8.8");
     private static final InetAddress TEST_IP6_DNS = parseNumericAddress("2001:db8:1::888");
+    private static final IpPrefix TEST_NAT64PREFIX = new IpPrefix("64:ff9b::/96");
+    private static final Inet6Address REMOTE_NAT64_ADDR =
+            (Inet6Address) parseNumericAddress("64:ff9b::808:808");
     private static final ByteBuffer TEST_REACHABILITY_PAYLOAD =
             ByteBuffer.wrap(new byte[] { (byte) 0x55, (byte) 0xaa });
 
     private static final String DUMPSYS_TETHERING_RAWMAP_ARG = "bpfRawMap";
     private static final String DUMPSYS_RAWMAP_ARG_STATS = "--stats";
     private static final String DUMPSYS_RAWMAP_ARG_UPSTREAM4 = "--upstream4";
-    private static final String BASE64_DELIMITER = ",";
     private static final String LINE_DELIMITER = "\\n";
 
+    // version=6, traffic class=0x0, flowlabel=0x0;
+    private static final int VERSION_TRAFFICCLASS_FLOWLABEL = 0x60000000;
+    private static final short HOP_LIMIT = 0x40;
+
     private final Context mContext = InstrumentationRegistry.getContext();
     private final EthernetManager mEm = mContext.getSystemService(EthernetManager.class);
     private final TetheringManager mTm = mContext.getSystemService(TetheringManager.class);
@@ -183,13 +192,12 @@
         mUiAutomation.adoptShellPermissionIdentity(
                 MANAGE_TEST_NETWORKS, NETWORK_SETTINGS, TETHER_PRIVILEGED, ACCESS_NETWORK_STATE,
                 CONNECTIVITY_USE_RESTRICTED_NETWORKS, DUMP);
+        mRunTests = mTm.isTetheringSupported() && mEm != null;
+        assumeTrue(mRunTests);
+
         mHandlerThread = new HandlerThread(getClass().getSimpleName());
         mHandlerThread.start();
         mHandler = new Handler(mHandlerThread.getLooper());
-
-        mRunTests = isEthernetTetheringSupported();
-        assumeTrue(mRunTests);
-
         mTetheredInterfaceRequester = new TetheredInterfaceRequester(mHandler, mEm);
     }
 
@@ -217,6 +225,7 @@
             mHandler.post(() -> reader.stop());
             mDownstreamReader = null;
         }
+        mHandlerThread.quitSafely();
         mTetheredInterfaceRequester.release();
         mEm.setIncludeTestInterfaces(false);
         maybeDeleteTestInterface();
@@ -227,7 +236,6 @@
         try {
             if (mRunTests) cleanUp();
         } finally {
-            mHandlerThread.quitSafely();
             mUiAutomation.dropShellPermissionIdentity();
         }
     }
@@ -316,27 +324,13 @@
 
     }
 
-    private static boolean isRouterAdvertisement(byte[] pkt) {
-        if (pkt == null) return false;
-
-        ByteBuffer buf = ByteBuffer.wrap(pkt);
-
-        final EthernetHeader ethHdr = Struct.parse(EthernetHeader.class, buf);
-        if (ethHdr.etherType != ETHER_TYPE_IPV6) return false;
-
-        final Ipv6Header ipv6Hdr = Struct.parse(Ipv6Header.class, buf);
-        if (ipv6Hdr.nextHeader != (byte) IPPROTO_ICMPV6) return false;
-
-        final Icmpv6Header icmpv6Hdr = Struct.parse(Icmpv6Header.class, buf);
-        return icmpv6Hdr.type == (short) ICMPV6_ROUTER_ADVERTISEMENT;
-    }
-
-    private static void expectRouterAdvertisement(TapPacketReader reader, String iface,
+    private static void waitForRouterAdvertisement(TapPacketReader reader, String iface,
             long timeoutMs) {
         final long deadline = SystemClock.uptimeMillis() + timeoutMs;
         do {
             byte[] pkt = reader.popPacket(timeoutMs);
-            if (isRouterAdvertisement(pkt)) return;
+            if (isExpectedIcmpv6Packet(pkt, true /* hasEth */, ICMPV6_ROUTER_ADVERTISEMENT)) return;
+
             timeoutMs = deadline - SystemClock.uptimeMillis();
         } while (timeoutMs > 0);
         fail("Did not receive router advertisement on " + iface + " after "
@@ -388,7 +382,7 @@
         // before the reader is started.
         mDownstreamReader = makePacketReader(mDownstreamIface);
 
-        expectRouterAdvertisement(mDownstreamReader, iface, 2000 /* timeoutMs */);
+        waitForRouterAdvertisement(mDownstreamReader, iface, WAIT_RA_TIMEOUT_MS);
         expectLocalOnlyAddresses(iface);
     }
 
@@ -416,23 +410,6 @@
         // client, which is not possible in this test.
     }
 
-    private boolean isEthernetTetheringSupported() throws Exception {
-        final CompletableFuture<Boolean> future = new CompletableFuture<>();
-        final TetheringEventCallback callback = new TetheringEventCallback() {
-            @Override
-            public void onSupportedTetheringTypes(Set<Integer> supportedTypes) {
-                future.complete(supportedTypes.contains(TETHERING_ETHERNET));
-            }
-        };
-
-        try {
-            mTm.registerTetheringEventCallback(mHandler::post, callback);
-            return future.get(TIMEOUT_MS, TimeUnit.MILLISECONDS);
-        } finally {
-            mTm.unregisterTetheringEventCallback(callback);
-        }
-    }
-
     private static final class MyTetheringEventCallback implements TetheringEventCallback {
         private final TetheringManager mTm;
         private final CountDownLatch mTetheringStartedLatch = new CountDownLatch(1);
@@ -781,36 +758,42 @@
         }
     }
 
-    private TestNetworkTracker createTestUpstream(final List<LinkAddress> addresses)
-            throws Exception {
+    private TestNetworkTracker createTestUpstream(final List<LinkAddress> addresses,
+            final List<InetAddress> dnses) throws Exception {
         mTm.setPreferTestNetworks(true);
 
-        return initTestNetwork(mContext, addresses, TIMEOUT_MS);
+        final LinkProperties lp = new LinkProperties();
+        lp.setLinkAddresses(addresses);
+        lp.setDnsServers(dnses);
+        lp.setNat64Prefix(TEST_NAT64PREFIX);
+
+        return initTestNetwork(mContext, lp, TIMEOUT_MS);
     }
 
     @Test
-    public void testTestNetworkUpstream() throws Exception {
-        assumeFalse(mEm.isAvailable());
+    public void testIcmpv6Echo() throws Exception {
+        runPing6Test(initTetheringTester(toList(TEST_IP4_ADDR, TEST_IP6_ADDR),
+                toList(TEST_IP4_DNS, TEST_IP6_DNS)));
+    }
 
-        // MyTetheringEventCallback currently only support await first available upstream. Tethering
-        // may select internet network as upstream if test network is not available and not be
-        // preferred yet. Create test upstream network before enable tethering.
-        mUpstreamTracker = createTestUpstream(toList(TEST_IP4_ADDR, TEST_IP6_ADDR));
+    private void runPing6Test(TetheringTester tester) throws Exception {
+        TetheredDevice tethered = tester.createTetheredDevice(MacAddress.fromString("1:2:3:4:5:6"),
+                true /* hasIpv6 */);
+        Inet6Address remoteIp6Addr = (Inet6Address) parseNumericAddress("2400:222:222::222");
+        ByteBuffer request = Ipv6Utils.buildEchoRequestPacket(tethered.macAddr,
+                tethered.routerMacAddr, tethered.ipv6Addr, remoteIp6Addr);
+        tester.verifyUpload(request, p -> {
+            Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
 
-        mDownstreamIface = createTestInterface();
-        mEm.setIncludeTestInterfaces(true);
+            return isExpectedIcmpv6Packet(p, false /* hasEth */, ICMPV6_ECHO_REQUEST_TYPE);
+        });
 
-        final String iface = mTetheredInterfaceRequester.getInterface();
-        assertEquals("TetheredInterfaceCallback for unexpected interface",
-                mDownstreamIface.getInterfaceName(), iface);
+        ByteBuffer reply = Ipv6Utils.buildEchoReplyPacket(remoteIp6Addr, tethered.ipv6Addr);
+        tester.verifyDownload(reply, p -> {
+            Log.d(TAG, "Packet in downstream: " + dumpHexString(p));
 
-        mTetheringEventCallback = enableEthernetTethering(mDownstreamIface.getInterfaceName(),
-                mUpstreamTracker.getNetwork());
-        assertEquals("onUpstreamChanged for unexpected network", mUpstreamTracker.getNetwork(),
-                mTetheringEventCallback.awaitUpstreamChanged());
-
-        mDownstreamReader = makePacketReader(mDownstreamIface);
-        // TODO: do basic forwarding test here.
+            return isExpectedIcmpv6Packet(p, true /* hasEth */, ICMPV6_ECHO_REPLY_TYPE);
+        });
     }
 
     // Test network topology:
@@ -828,12 +811,11 @@
     // Used by public port and private port. Assume port 9876 has not been used yet before the
     // testing that public port and private port are the same in the testing. Note that NAT port
     // forwarding could be different between private port and public port.
+    // TODO: move to the start of test class.
     private static final short LOCAL_PORT = 9876;
     private static final short REMOTE_PORT = 433;
     private static final byte TYPE_OF_SERVICE = 0;
     private static final short ID = 27149;
-    private static final short ID2 = 27150;
-    private static final short ID3 = 27151;
     private static final short FLAGS_AND_FRAGMENT_OFFSET = (short) 0x4000; // flags=DF, offset=0
     private static final byte TIME_TO_LIVE = (byte) 0x40;
     private static final ByteBuffer PAYLOAD =
@@ -843,43 +825,48 @@
     private static final ByteBuffer PAYLOAD3 =
             ByteBuffer.wrap(new byte[] { (byte) 0x9a, (byte) 0xbc });
 
-    private boolean isExpectedUdpPacket(@NonNull final byte[] rawPacket, boolean hasEther,
-            @NonNull final ByteBuffer payload) {
-        final ByteBuffer buf = ByteBuffer.wrap(rawPacket);
-
-        if (hasEther) {
-            final EthernetHeader etherHeader = Struct.parse(EthernetHeader.class, buf);
-            if (etherHeader == null) return false;
-        }
-
-        final Ipv4Header ipv4Header = Struct.parse(Ipv4Header.class, buf);
-        if (ipv4Header == null) return false;
-
-        final UdpHeader udpHeader = Struct.parse(UdpHeader.class, buf);
-        if (udpHeader == null) return false;
-
-        if (buf.remaining() != payload.limit()) return false;
-
-        return Arrays.equals(Arrays.copyOfRange(buf.array(), buf.position(), buf.limit()),
-                payload.array());
-    }
-
     @NonNull
-    private ByteBuffer buildUdpv4Packet(@Nullable final MacAddress srcMac,
-            @Nullable final MacAddress dstMac, short id,
-            @NonNull final Inet4Address srcIp, @NonNull final Inet4Address dstIp,
+    private ByteBuffer buildUdpPacket(
+            @Nullable final MacAddress srcMac, @Nullable final MacAddress dstMac,
+            @NonNull final InetAddress srcIp, @NonNull final InetAddress dstIp,
             short srcPort, short dstPort, @Nullable final ByteBuffer payload)
             throws Exception {
+        int ipProto;
+        short ethType;
+        if (srcIp instanceof Inet4Address && dstIp instanceof Inet4Address) {
+            ipProto = IPPROTO_IP;
+            ethType = (short) ETHER_TYPE_IPV4;
+        } else if (srcIp instanceof Inet6Address && dstIp instanceof Inet6Address) {
+            ipProto = IPPROTO_IPV6;
+            ethType = (short) ETHER_TYPE_IPV6;
+        } else {
+            fail("Unsupported conditions: srcIp " + srcIp + ", dstIp " + dstIp);
+            // Make compiler happy to the uninitialized ipProto and ethType.
+            return null;  // unreachable, the annotation @NonNull of function return value is true.
+        }
+
         final boolean hasEther = (srcMac != null && dstMac != null);
         final int payloadLen = (payload == null) ? 0 : payload.limit();
-        final ByteBuffer buffer = PacketBuilder.allocate(hasEther, IPPROTO_IP, IPPROTO_UDP,
+        final ByteBuffer buffer = PacketBuilder.allocate(hasEther, ipProto, IPPROTO_UDP,
                 payloadLen);
         final PacketBuilder packetBuilder = new PacketBuilder(buffer);
 
+        // [1] Ethernet header
         if (hasEther) packetBuilder.writeL2Header(srcMac, dstMac, (short) ETHER_TYPE_IPV4);
-        packetBuilder.writeIpv4Header(TYPE_OF_SERVICE, ID, FLAGS_AND_FRAGMENT_OFFSET,
-                TIME_TO_LIVE, (byte) IPPROTO_UDP, srcIp, dstIp);
+
+        // [2] IP header
+        if (ipProto == IPPROTO_IP) {
+            packetBuilder.writeIpv4Header(TYPE_OF_SERVICE, ID, FLAGS_AND_FRAGMENT_OFFSET,
+                    TIME_TO_LIVE, (byte) IPPROTO_UDP, (Inet4Address) srcIp, (Inet4Address) dstIp);
+        } else {
+            packetBuilder.writeIpv6Header(VERSION_TRAFFICCLASS_FLOWLABEL, (byte) IPPROTO_UDP,
+                    HOP_LIMIT, (Inet6Address) srcIp, (Inet6Address) dstIp);
+        }
+
+        // [3] UDP header
         packetBuilder.writeUdpHeader(srcPort, dstPort);
+
+        // [4] Payload
         if (payload != null) {
             buffer.put(payload);
             // in case data might be reused by caller, restore the position and
@@ -891,38 +878,47 @@
     }
 
     @NonNull
-    private ByteBuffer buildUdpv4Packet(short id, @NonNull final Inet4Address srcIp,
-            @NonNull final Inet4Address dstIp, short srcPort, short dstPort,
+    private ByteBuffer buildUdpPacket(@NonNull final InetAddress srcIp,
+            @NonNull final InetAddress dstIp, short srcPort, short dstPort,
             @Nullable final ByteBuffer payload) throws Exception {
-        return buildUdpv4Packet(null /* srcMac */, null /* dstMac */, id, srcIp, dstIp, srcPort,
+        return buildUdpPacket(null /* srcMac */, null /* dstMac */, srcIp, dstIp, srcPort,
                 dstPort, payload);
     }
 
-    // TODO: remove this verification once upstream connected notification race is fixed.
-    // See #runUdp4Test.
-    private boolean isIpv4TetherConnectivityVerified(TetheringTester tester,
-            RemoteResponder remote, TetheredDevice tethered) throws Exception {
-        final ByteBuffer probePacket = buildUdpv4Packet(tethered.macAddr,
-                tethered.routerMacAddr, ID, tethered.ipv4Addr /* srcIp */,
-                REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */, REMOTE_PORT /*dstPort */,
+    // TODO: remove ipv4 verification (is4To6 = false) once upstream connected notification race is
+    // fixed. See #runUdp4Test.
+    //
+    // This function sends a probe packet to downstream interface and exam the result from upstream
+    // interface to make sure ipv4 tethering is ready. Return the entire packet which received from
+    // upstream interface.
+    @NonNull
+    private byte[] probeV4TetheringConnectivity(TetheringTester tester, TetheredDevice tethered,
+            boolean is4To6) throws Exception {
+        final ByteBuffer probePacket = buildUdpPacket(tethered.macAddr,
+                tethered.routerMacAddr, tethered.ipv4Addr /* srcIp */,
+                REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */, REMOTE_PORT /* dstPort */,
                 TEST_REACHABILITY_PAYLOAD);
 
         // Send a UDP packet from client and check the packet can be found on upstream interface.
         for (int i = 0; i < TETHER_REACHABILITY_ATTEMPTS; i++) {
-            tester.sendPacket(probePacket);
-            byte[] expectedPacket = remote.getNextMatchedPacket(p -> {
+            byte[] expectedPacket = tester.testUpload(probePacket, p -> {
                 Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
-                return isExpectedUdpPacket(p, false /* hasEther */, TEST_REACHABILITY_PAYLOAD);
+                // If is4To6 is true, the ipv4 probe packet would be translated to ipv6 by Clat and
+                // would see this translated ipv6 packet in upstream interface.
+                return isExpectedUdpPacket(p, false /* hasEther */, !is4To6 /* isIpv4 */,
+                        TEST_REACHABILITY_PAYLOAD);
             });
-            if (expectedPacket != null) return true;
+            if (expectedPacket != null) return expectedPacket;
         }
-        return false;
+
+        fail("Can't verify " + (is4To6 ? "ipv4 to ipv6" : "ipv4") + " tethering connectivity after "
+                + TETHER_REACHABILITY_ATTEMPTS + " attempts");
+        return null;
     }
 
-    private void runUdp4Test(TetheringTester tester, RemoteResponder remote, boolean usingBpf)
-            throws Exception {
+    private void runUdp4Test(TetheringTester tester, boolean usingBpf) throws Exception {
         final TetheredDevice tethered = tester.createTetheredDevice(MacAddress.fromString(
-                "1:2:3:4:5:6"));
+                "1:2:3:4:5:6"), false /* hasIpv6 */);
 
         // TODO: remove the connectivity verification for upstream connected notification race.
         // Because async upstream connected notification can't guarantee the tethering routing is
@@ -930,26 +926,26 @@
         // For short term plan, consider using IPv6 RA to get MAC address because the prefix comes
         // from upstream. That can guarantee that the routing is ready. Long term plan is that
         // refactors upstream connected notification from async to sync.
-        assertTrue(isIpv4TetherConnectivityVerified(tester, remote, tethered));
+        probeV4TetheringConnectivity(tester, tethered, false /* is4To6 */);
 
         // Send a UDP packet in original direction.
-        final ByteBuffer originalPacket = buildUdpv4Packet(tethered.macAddr,
-                tethered.routerMacAddr, ID, tethered.ipv4Addr /* srcIp */,
-                REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */, REMOTE_PORT /*dstPort */,
+        final ByteBuffer originalPacket = buildUdpPacket(tethered.macAddr,
+                tethered.routerMacAddr, tethered.ipv4Addr /* srcIp */,
+                REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */, REMOTE_PORT /* dstPort */,
                 PAYLOAD /* payload */);
-        tester.verifyUpload(remote, originalPacket, p -> {
+        tester.verifyUpload(originalPacket, p -> {
             Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
-            return isExpectedUdpPacket(p, false /* hasEther */, PAYLOAD);
+            return isExpectedUdpPacket(p, false /* hasEther */, true /* isIpv4 */, PAYLOAD);
         });
 
         // Send a UDP packet in reply direction.
         final Inet4Address publicIp4Addr = (Inet4Address) TEST_IP4_ADDR.getAddress();
-        final ByteBuffer replyPacket = buildUdpv4Packet(ID2, REMOTE_IP4_ADDR /* srcIp */,
-                publicIp4Addr /* dstIp */, REMOTE_PORT /* srcPort */, LOCAL_PORT /*dstPort */,
+        final ByteBuffer replyPacket = buildUdpPacket(REMOTE_IP4_ADDR /* srcIp */,
+                publicIp4Addr /* dstIp */, REMOTE_PORT /* srcPort */, LOCAL_PORT /* dstPort */,
                 PAYLOAD2 /* payload */);
-        remote.verifyDownload(tester, replyPacket, p -> {
+        tester.verifyDownload(replyPacket, p -> {
             Log.d(TAG, "Packet in downstream: " + dumpHexString(p));
-            return isExpectedUdpPacket(p, true/* hasEther */, PAYLOAD2);
+            return isExpectedUdpPacket(p, true /* hasEther */, true /* isIpv4 */, PAYLOAD2);
         });
 
         if (usingBpf) {
@@ -962,13 +958,13 @@
             // See kernel upstream commit b7b1d02fc43925a4d569ec221715db2dfa1ce4f5 and
             // nf_conntrack_udp_packet in net/netfilter/nf_conntrack_proto_udp.c
             Thread.sleep(UDP_STREAM_TS_MS);
-            final ByteBuffer originalPacket2 = buildUdpv4Packet(tethered.macAddr,
-                    tethered.routerMacAddr, ID, tethered.ipv4Addr /* srcIp */,
+            final ByteBuffer originalPacket2 = buildUdpPacket(tethered.macAddr,
+                    tethered.routerMacAddr, tethered.ipv4Addr /* srcIp */,
                     REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */,
-                    REMOTE_PORT /*dstPort */, PAYLOAD3 /* payload */);
-            tester.verifyUpload(remote, originalPacket2, p -> {
+                    REMOTE_PORT /* dstPort */, PAYLOAD3 /* payload */);
+            tester.verifyUpload(originalPacket2, p -> {
                 Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
-                return isExpectedUdpPacket(p, false /* hasEther */, PAYLOAD3);
+                return isExpectedUdpPacket(p, false /* hasEther */, true /* isIpv4 */, PAYLOAD3);
             });
 
             // [1] Verify IPv4 upstream rule map.
@@ -1002,17 +998,17 @@
 
             // Send packets on original direction.
             for (int i = 0; i < TX_UDP_PACKET_COUNT; i++) {
-                tester.verifyUpload(remote, originalPacket, p -> {
+                tester.verifyUpload(originalPacket, p -> {
                     Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
-                    return isExpectedUdpPacket(p, false /* hasEther */, PAYLOAD);
+                    return isExpectedUdpPacket(p, false /* hasEther */, true /* isIpv4 */, PAYLOAD);
                 });
             }
 
             // Send packets on reply direction.
             for (int i = 0; i < RX_UDP_PACKET_COUNT; i++) {
-                remote.verifyDownload(tester, replyPacket, p -> {
+                tester.verifyDownload(replyPacket, p -> {
                     Log.d(TAG, "Packet in downstream: " + dumpHexString(p));
-                    return isExpectedUdpPacket(p, true/* hasEther */, PAYLOAD2);
+                    return isExpectedUdpPacket(p, true /* hasEther */, true /* isIpv4 */, PAYLOAD2);
                 });
             }
 
@@ -1037,20 +1033,21 @@
         }
     }
 
-    void initializeTethering() throws Exception {
+    private TetheringTester initTetheringTester(List<LinkAddress> upstreamAddresses,
+            List<InetAddress> upstreamDnses) throws Exception {
         assumeFalse(mEm.isAvailable());
 
         // MyTetheringEventCallback currently only support await first available upstream. Tethering
         // may select internet network as upstream if test network is not available and not be
         // preferred yet. Create test upstream network before enable tethering.
-        mUpstreamTracker = createTestUpstream(toList(TEST_IP4_ADDR));
+        mUpstreamTracker = createTestUpstream(upstreamAddresses, upstreamDnses);
 
         mDownstreamIface = createTestInterface();
         mEm.setIncludeTestInterfaces(true);
 
-        final String iface = mTetheredInterfaceRequester.getInterface();
+        // Make sure EtherentTracker use "mDownstreamIface" as server mode interface.
         assertEquals("TetheredInterfaceCallback for unexpected interface",
-                mDownstreamIface.getInterfaceName(), iface);
+                mDownstreamIface.getInterfaceName(), mTetheredInterfaceRequester.getInterface());
 
         mTetheringEventCallback = enableEthernetTethering(mDownstreamIface.getInterfaceName(),
                 mUpstreamTracker.getNetwork());
@@ -1059,13 +1056,22 @@
 
         mDownstreamReader = makePacketReader(mDownstreamIface);
         mUpstreamReader = makePacketReader(mUpstreamTracker.getTestIface());
+
+        final ConnectivityManager cm = mContext.getSystemService(ConnectivityManager.class);
+        // Currently tethering don't have API to tell when ipv6 tethering is available. Thus, make
+        // sure tethering already have ipv6 connectivity before testing.
+        if (cm.getLinkProperties(mUpstreamTracker.getNetwork()).hasGlobalIpv6Address()) {
+            waitForRouterAdvertisement(mDownstreamReader, mDownstreamIface.getInterfaceName(),
+                    WAIT_RA_TIMEOUT_MS);
+        }
+
+        return new TetheringTester(mDownstreamReader, mUpstreamReader);
     }
 
     @Test
     @IgnoreAfter(Build.VERSION_CODES.R)
     public void testTetherUdpV4UpToR() throws Exception {
-        initializeTethering();
-        runUdp4Test(new TetheringTester(mDownstreamReader), new RemoteResponder(mUpstreamReader),
+        runUdp4Test(initTetheringTester(toList(TEST_IP4_ADDR), toList(TEST_IP4_DNS)),
                 false /* usingBpf */);
     }
 
@@ -1100,15 +1106,19 @@
     @Test
     @IgnoreUpTo(Build.VERSION_CODES.R)
     public void testTetherUdpV4AfterR() throws Exception {
-        initializeTethering();
         final String kernelVersion = VintfRuntimeInfo.getKernelVersion();
-        boolean usingBpf = isUdpOffloadSupportedByKernel(kernelVersion);
-        if (!usingBpf) {
+        final boolean isUdpOffloadSupported = isUdpOffloadSupportedByKernel(kernelVersion);
+        if (!isUdpOffloadSupported) {
             Log.i(TAG, "testTetherUdpV4AfterR will skip BPF offload test for kernel "
                     + kernelVersion);
         }
-        runUdp4Test(new TetheringTester(mDownstreamReader), new RemoteResponder(mUpstreamReader),
-                usingBpf);
+        final boolean isTetherConfigBpfOffloadEnabled = isTetherConfigBpfOffloadEnabled();
+        if (!isTetherConfigBpfOffloadEnabled) {
+            Log.i(TAG, "testTetherUdpV4AfterR will skip BPF offload test "
+                    + "because tethering config doesn't enable BPF offload.");
+        }
+        runUdp4Test(initTetheringTester(toList(TEST_IP4_ADDR), toList(TEST_IP4_DNS)),
+                isUdpOffloadSupported && isTetherConfigBpfOffloadEnabled);
     }
 
     @Nullable
@@ -1167,6 +1177,85 @@
         return null;
     }
 
+    private boolean isTetherConfigBpfOffloadEnabled() throws Exception {
+        final String dumpStr = DumpTestUtils.dumpService(Context.TETHERING_SERVICE, "--short");
+
+        // BPF offload tether config can be overridden by "config_tether_enable_bpf_offload" in
+        // packages/modules/Connectivity/Tethering/res/values/config.xml. OEM may disable config by
+        // RRO to override the enabled default value. Get the tethering config via dumpsys.
+        // $ dumpsys tethering
+        //   mIsBpfEnabled: true
+        boolean enabled = dumpStr.contains("mIsBpfEnabled: true");
+        if (!enabled) {
+            Log.d(TAG, "BPF offload tether config not enabled: " + dumpStr);
+        }
+        return enabled;
+    }
+
+    @NonNull
+    private Inet6Address getClatIpv6Address(TetheringTester tester, TetheredDevice tethered)
+            throws Exception {
+        // Send an IPv4 UDP packet from client and check that a CLAT translated IPv6 UDP packet can
+        // be found on upstream interface. Get CLAT IPv6 address from the CLAT translated IPv6 UDP
+        // packet.
+        byte[] expectedPacket = probeV4TetheringConnectivity(tester, tethered, true /* is4To6 */);
+
+        // Above has guaranteed that the found packet is an IPv6 packet without ether header.
+        return Struct.parse(Ipv6Header.class, ByteBuffer.wrap(expectedPacket)).srcIp;
+    }
+
+    // Test network topology:
+    //
+    //            public network (rawip)                 private network
+    //                      |         UE (CLAT support)         |
+    // +---------------+    V    +------------+------------+    V    +------------+
+    // | NAT64 Gateway +---------+  Upstream  | Downstream +---------+   Client   |
+    // +---------------+         +------------+------------+         +------------+
+    // remote ip                 public ip                           private ip
+    // [64:ff9b::808:808]:443    [clat ipv6]:9876                    [TetheredDevice ipv4]:9876
+    //
+    // Note that CLAT IPv6 address is generated by ClatCoordinator. Get the CLAT IPv6 address by
+    // sending out an IPv4 packet and extracting the source address from CLAT translated IPv6
+    // packet.
+    //
+    private void runClatUdpTest(TetheringTester tester) throws Exception {
+        final TetheredDevice tethered = tester.createTetheredDevice(MacAddress.fromString(
+                "1:2:3:4:5:6"), true /* hasIpv6 */);
+
+        // Get CLAT IPv6 address.
+        final Inet6Address clatAddr6 = getClatIpv6Address(tester, tethered);
+
+        // Send an IPv4 UDP packet in original direction.
+        // IPv4 packet -- CLAT translation --> IPv6 packet
+        final ByteBuffer originalPacket = buildUdpPacket(tethered.macAddr,
+                tethered.routerMacAddr, tethered.ipv4Addr /* srcIp */,
+                REMOTE_IP4_ADDR /* dstIp */, LOCAL_PORT /* srcPort */, REMOTE_PORT /* dstPort */,
+                PAYLOAD /* payload */);
+        tester.verifyUpload(originalPacket, p -> {
+            Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
+            return isExpectedUdpPacket(p, false /* hasEther */, false /* isIpv4 */, PAYLOAD);
+        });
+
+        // Send an IPv6 UDP packet in reply direction.
+        // IPv6 packet -- CLAT translation --> IPv4 packet
+        final ByteBuffer replyPacket = buildUdpPacket(REMOTE_NAT64_ADDR /* srcIp */,
+                clatAddr6 /* dstIp */, REMOTE_PORT /* srcPort */, LOCAL_PORT /* dstPort */,
+                PAYLOAD2 /* payload */);
+        tester.verifyDownload(replyPacket, p -> {
+            Log.d(TAG, "Packet in downstream: " + dumpHexString(p));
+            return isExpectedUdpPacket(p, true /* hasEther */, true /* isIpv4 */, PAYLOAD2);
+        });
+
+        // TODO: test CLAT bpf maps.
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.R)
+    public void testTetherClatUdp() throws Exception {
+        // CLAT only starts on IPv6 only network.
+        runClatUdpTest(initTetheringTester(toList(TEST_IP6_ADDR), toList(TEST_IP6_DNS)));
+    }
+
     private <T> List<T> toList(T... array) {
         return Arrays.asList(array);
     }
diff --git a/Tethering/tests/integration/src/android/net/TetheringTester.java b/Tethering/tests/integration/src/android/net/TetheringTester.java
index d24661a..4d90d39 100644
--- a/Tethering/tests/integration/src/android/net/TetheringTester.java
+++ b/Tethering/tests/integration/src/android/net/TetheringTester.java
@@ -16,10 +16,24 @@
 
 package android.net;
 
+import static android.net.InetAddresses.parseNumericAddress;
+import static android.system.OsConstants.IPPROTO_ICMPV6;
+import static android.system.OsConstants.IPPROTO_UDP;
+
 import static com.android.net.module.util.NetworkStackConstants.ARP_REPLY;
 import static com.android.net.module.util.NetworkStackConstants.ARP_REQUEST;
 import static com.android.net.module.util.NetworkStackConstants.ETHER_ADDR_LEN;
 import static com.android.net.module.util.NetworkStackConstants.ETHER_BROADCAST;
+import static com.android.net.module.util.NetworkStackConstants.ETHER_TYPE_IPV4;
+import static com.android.net.module.util.NetworkStackConstants.ETHER_TYPE_IPV6;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ND_OPTION_PIO;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ND_OPTION_SLLA;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ND_OPTION_TLLA;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_NEIGHBOR_SOLICITATION;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ROUTER_ADVERTISEMENT;
+import static com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ALL_NODES_MULTICAST;
+import static com.android.net.module.util.NetworkStackConstants.NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE;
+import static com.android.net.module.util.NetworkStackConstants.NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED;
 
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
@@ -30,13 +44,30 @@
 import android.util.ArrayMap;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
+import com.android.net.module.util.Ipv6Utils;
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.structs.EthernetHeader;
+import com.android.net.module.util.structs.Icmpv6Header;
+import com.android.net.module.util.structs.Ipv4Header;
+import com.android.net.module.util.structs.Ipv6Header;
+import com.android.net.module.util.structs.LlaOption;
+import com.android.net.module.util.structs.NsHeader;
+import com.android.net.module.util.structs.PrefixInformationOption;
+import com.android.net.module.util.structs.RaHeader;
+import com.android.net.module.util.structs.UdpHeader;
 import com.android.networkstack.arp.ArpPacket;
 import com.android.testutils.TapPacketReader;
 
 import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Random;
 import java.util.concurrent.TimeoutException;
 import java.util.function.Predicate;
@@ -50,31 +81,40 @@
     private static final String TAG = TetheringTester.class.getSimpleName();
     private static final int PACKET_READ_TIMEOUT_MS = 100;
     private static final int DHCP_DISCOVER_ATTEMPTS = 10;
+    private static final int READ_RA_ATTEMPTS = 10;
     private static final byte[] DHCP_REQUESTED_PARAMS = new byte[] {
             DhcpPacket.DHCP_SUBNET_MASK,
             DhcpPacket.DHCP_ROUTER,
             DhcpPacket.DHCP_DNS_SERVER,
             DhcpPacket.DHCP_LEASE_TIME,
     };
+    private static final InetAddress LINK_LOCAL = parseNumericAddress("fe80::1");
 
     public static final String DHCP_HOSTNAME = "testhostname";
 
     private final ArrayMap<MacAddress, TetheredDevice> mTetheredDevices;
     private final TapPacketReader mDownstreamReader;
+    private final TapPacketReader mUpstreamReader;
 
     public TetheringTester(TapPacketReader downstream) {
+        this(downstream, null);
+    }
+
+    public TetheringTester(TapPacketReader downstream, TapPacketReader upstream) {
         if (downstream == null) fail("Downstream reader could not be NULL");
 
         mDownstreamReader = downstream;
+        mUpstreamReader = upstream;
         mTetheredDevices = new ArrayMap<>();
     }
 
-    public TetheredDevice createTetheredDevice(MacAddress macAddr) throws Exception {
+    public TetheredDevice createTetheredDevice(MacAddress macAddr, boolean hasIpv6)
+            throws Exception {
         if (mTetheredDevices.get(macAddr) != null) {
             fail("Tethered device already created");
         }
 
-        TetheredDevice tethered = new TetheredDevice(macAddr);
+        TetheredDevice tethered = new TetheredDevice(macAddr, hasIpv6);
         mTetheredDevices.put(macAddr, tethered);
 
         return tethered;
@@ -84,14 +124,15 @@
         public final MacAddress macAddr;
         public final MacAddress routerMacAddr;
         public final Inet4Address ipv4Addr;
+        public final Inet6Address ipv6Addr;
 
-        private TetheredDevice(MacAddress mac) throws Exception {
+        private TetheredDevice(MacAddress mac, boolean hasIpv6) throws Exception {
             macAddr = mac;
-
             DhcpResults dhcpResults = runDhcp(macAddr.toByteArray());
             ipv4Addr = (Inet4Address) dhcpResults.ipAddress.getAddress();
             routerMacAddr = getRouterMacAddressFromArp(ipv4Addr, macAddr,
                     dhcpResults.serverAddress);
+            ipv6Addr = hasIpv6 ? runSlaac(macAddr, routerMacAddr) : null;
         }
     }
 
@@ -141,7 +182,7 @@
     }
 
     private DhcpPacket getNextDhcpPacket() throws Exception {
-        final byte[] packet = getNextMatchedPacket((p) -> {
+        final byte[] packet = getDownloadPacket((p) -> {
             // Test whether this is DHCP packet.
             try {
                 DhcpPacket.decodeFullPacket(p, p.length, DhcpPacket.ENCAP_L2);
@@ -184,7 +225,7 @@
                     tethered.ipv4Addr.getAddress() /* sender IP */,
                     (short) ARP_REPLY);
             try {
-                sendPacket(arpReply);
+                sendUploadPacket(arpReply);
             } catch (Exception e) {
                 fail("Failed to reply ARP for " + tethered.ipv4Addr);
             }
@@ -198,9 +239,9 @@
                 tetherMac.toByteArray() /* srcMac */, routerIp.getAddress() /* target IP */,
                 new byte[ETHER_ADDR_LEN] /* target HW address */,
                 tetherIp.getAddress() /* sender IP */, (short) ARP_REQUEST);
-        sendPacket(arpProbe);
+        sendUploadPacket(arpProbe);
 
-        final byte[] packet = getNextMatchedPacket((p) -> {
+        final byte[] packet = getDownloadPacket((p) -> {
             final ArpPacket arpPacket = parseArpPacket(p);
             if (arpPacket == null || arpPacket.opCode != ARP_REPLY) return false;
             return arpPacket.targetIp.equals(tetherIp);
@@ -216,45 +257,205 @@
         return null;
     }
 
-    public void sendPacket(ByteBuffer packet) throws Exception {
+    private List<PrefixInformationOption> getRaPrefixOptions(byte[] packet) {
+        ByteBuffer buf = ByteBuffer.wrap(packet);
+        if (!isExpectedIcmpv6Packet(buf, true /* hasEth */, ICMPV6_ROUTER_ADVERTISEMENT)) {
+            fail("Parsing RA packet fail");
+        }
+
+        Struct.parse(RaHeader.class, buf);
+        final ArrayList<PrefixInformationOption> pioList = new ArrayList<>();
+        while (buf.position() < packet.length) {
+            final int currentPos = buf.position();
+            final int type = Byte.toUnsignedInt(buf.get());
+            final int length = Byte.toUnsignedInt(buf.get());
+            if (type == ICMPV6_ND_OPTION_PIO) {
+                final ByteBuffer pioBuf = ByteBuffer.wrap(buf.array(), currentPos,
+                        Struct.getSize(PrefixInformationOption.class));
+                final PrefixInformationOption pio =
+                        Struct.parse(PrefixInformationOption.class, pioBuf);
+                pioList.add(pio);
+
+                // Move ByteBuffer position to the next option.
+                buf.position(currentPos + Struct.getSize(PrefixInformationOption.class));
+            } else {
+                buf.position(currentPos + (length * 8));
+            }
+        }
+        return pioList;
+    }
+
+    private Inet6Address runSlaac(MacAddress srcMac, MacAddress dstMac) throws Exception {
+        sendRsPacket(srcMac, dstMac);
+
+        final byte[] raPacket = verifyPacketNotNull("Receive RA fail", getDownloadPacket(p -> {
+            return isExpectedIcmpv6Packet(p, true /* hasEth */, ICMPV6_ROUTER_ADVERTISEMENT);
+        }));
+
+        final List<PrefixInformationOption> options = getRaPrefixOptions(raPacket);
+
+        for (PrefixInformationOption pio : options) {
+            if (pio.validLifetime > 0) {
+                final byte[] addressBytes = pio.prefix;
+                // Random the last two bytes as suffix.
+                // TODO: Currently do not implmement DAD in the test. Rely the gateway ipv6 address
+                // genetrated by tethering module always has random the last byte.
+                addressBytes[addressBytes.length - 1] = (byte) (new Random()).nextInt();
+                addressBytes[addressBytes.length - 2] = (byte) (new Random()).nextInt();
+
+                return (Inet6Address) InetAddress.getByAddress(addressBytes);
+            }
+        }
+
+        fail("No available ipv6 prefix");
+        return null;
+    }
+
+    private void sendRsPacket(MacAddress srcMac, MacAddress dstMac) throws Exception {
+        Log.d(TAG, "Sending RS");
+        ByteBuffer slla = LlaOption.build((byte) ICMPV6_ND_OPTION_SLLA, srcMac);
+        ByteBuffer rs = Ipv6Utils.buildRsPacket(srcMac, dstMac, (Inet6Address) LINK_LOCAL,
+                IPV6_ADDR_ALL_NODES_MULTICAST, slla);
+
+        sendUploadPacket(rs);
+    }
+
+    private void maybeReplyNa(byte[] packet) {
+        ByteBuffer buf = ByteBuffer.wrap(packet);
+        final EthernetHeader ethHdr = Struct.parse(EthernetHeader.class, buf);
+        if (ethHdr.etherType != ETHER_TYPE_IPV6) return;
+
+        final Ipv6Header ipv6Hdr = Struct.parse(Ipv6Header.class, buf);
+        if (ipv6Hdr.nextHeader != (byte) IPPROTO_ICMPV6) return;
+
+        final Icmpv6Header icmpv6Hdr = Struct.parse(Icmpv6Header.class, buf);
+        if (icmpv6Hdr.type != (short) ICMPV6_NEIGHBOR_SOLICITATION) return;
+
+        final NsHeader nsHdr = Struct.parse(NsHeader.class, buf);
+        for (int i = 0; i < mTetheredDevices.size(); i++) {
+            TetheredDevice tethered = mTetheredDevices.valueAt(i);
+            if (!nsHdr.target.equals(tethered.ipv6Addr)) continue;
+
+            final ByteBuffer tlla = LlaOption.build((byte) ICMPV6_ND_OPTION_TLLA, tethered.macAddr);
+            int flags = NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED
+                    | NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE;
+            ByteBuffer ns = Ipv6Utils.buildNaPacket(tethered.macAddr, tethered.routerMacAddr,
+                    nsHdr.target, ipv6Hdr.srcIp, flags, nsHdr.target, tlla);
+            try {
+                sendUploadPacket(ns);
+            } catch (Exception e) {
+                fail("Failed to reply NA for " + tethered.ipv6Addr);
+            }
+
+            return;
+        }
+    }
+
+    public static boolean isExpectedIcmpv6Packet(byte[] packet, boolean hasEth, int type) {
+        final ByteBuffer buf = ByteBuffer.wrap(packet);
+        return isExpectedIcmpv6Packet(buf, hasEth, type);
+    }
+
+    private static boolean isExpectedIcmpv6Packet(ByteBuffer buf, boolean hasEth, int type) {
+        try {
+            if (hasEth && !hasExpectedEtherHeader(buf, false /* isIpv4 */)) return false;
+
+            if (!hasExpectedIpHeader(buf, false /* isIpv4 */, IPPROTO_ICMPV6)) return false;
+
+            return Struct.parse(Icmpv6Header.class, buf).type == (short) type;
+        } catch (Exception e) {
+            // Parsing packet fail means it is not icmpv6 packet.
+        }
+
+        return false;
+    }
+
+    private static boolean hasExpectedEtherHeader(@NonNull final ByteBuffer buf, boolean isIpv4)
+            throws Exception {
+        final int expected = isIpv4 ? ETHER_TYPE_IPV4 : ETHER_TYPE_IPV6;
+
+        return Struct.parse(EthernetHeader.class, buf).etherType == expected;
+    }
+
+    private static boolean hasExpectedIpHeader(@NonNull final ByteBuffer buf, boolean isIpv4,
+            int ipProto) throws Exception {
+        if (isIpv4) {
+            return Struct.parse(Ipv4Header.class, buf).protocol == (byte) ipProto;
+        } else {
+            return Struct.parse(Ipv6Header.class, buf).nextHeader == (byte) ipProto;
+        }
+    }
+
+    public static boolean isExpectedUdpPacket(@NonNull final byte[] rawPacket, boolean hasEth,
+            boolean isIpv4, @NonNull final ByteBuffer payload) {
+        final ByteBuffer buf = ByteBuffer.wrap(rawPacket);
+        try {
+            if (hasEth && !hasExpectedEtherHeader(buf, isIpv4)) return false;
+
+            if (!hasExpectedIpHeader(buf, isIpv4, IPPROTO_UDP)) return false;
+
+            if (Struct.parse(UdpHeader.class, buf) == null) return false;
+        } catch (Exception e) {
+            // Parsing packet fail means it is not udp packet.
+            return false;
+        }
+
+        if (buf.remaining() != payload.limit()) return false;
+
+        return Arrays.equals(Arrays.copyOfRange(buf.array(), buf.position(), buf.limit()),
+                payload.array());
+    }
+
+    private void sendUploadPacket(ByteBuffer packet) throws Exception {
         mDownstreamReader.sendResponse(packet);
     }
 
-    public byte[] getNextMatchedPacket(Predicate<byte[]> filter) {
+    private void sendDownloadPacket(ByteBuffer packet) throws Exception {
+        assertNotNull("Can't deal with upstream interface in local only mode", mUpstreamReader);
+
+        mUpstreamReader.sendResponse(packet);
+    }
+
+    private byte[] getDownloadPacket(Predicate<byte[]> filter) {
         byte[] packet;
         while ((packet = mDownstreamReader.poll(PACKET_READ_TIMEOUT_MS)) != null) {
             if (filter.test(packet)) return packet;
 
             maybeReplyArp(packet);
+            maybeReplyNa(packet);
         }
 
         return null;
     }
 
-    public void verifyUpload(final RemoteResponder dst, final ByteBuffer packet,
-            final Predicate<byte[]> filter) throws Exception {
-        sendPacket(packet);
-        assertNotNull("Upload fail", dst.getNextMatchedPacket(filter));
+    private byte[] getUploadPacket(Predicate<byte[]> filter) {
+        assertNotNull("Can't deal with upstream interface in local only mode", mUpstreamReader);
+
+        return mUpstreamReader.poll(PACKET_READ_TIMEOUT_MS, filter);
     }
 
-    public static class RemoteResponder {
-        final TapPacketReader mUpstreamReader;
-        public RemoteResponder(TapPacketReader reader) {
-            mUpstreamReader = reader;
-        }
+    private @NonNull byte[] verifyPacketNotNull(String message, @Nullable byte[] packet) {
+        assertNotNull(message, packet);
 
-        public void sendPacket(ByteBuffer packet) throws Exception {
-            mUpstreamReader.sendResponse(packet);
-        }
+        return packet;
+    }
 
-        public byte[] getNextMatchedPacket(Predicate<byte[]> filter) throws Exception {
-            return mUpstreamReader.poll(PACKET_READ_TIMEOUT_MS, filter);
-        }
+    public byte[] testUpload(final ByteBuffer packet, final Predicate<byte[]> filter)
+            throws Exception {
+        sendUploadPacket(packet);
 
-        public void verifyDownload(final TetheringTester dst, final ByteBuffer packet,
-                final Predicate<byte[]> filter) throws Exception {
-            sendPacket(packet);
-            assertNotNull("Download fail", dst.getNextMatchedPacket(filter));
-        }
+        return getUploadPacket(filter);
+    }
+
+    public byte[] verifyUpload(final ByteBuffer packet, final Predicate<byte[]> filter)
+            throws Exception {
+        return verifyPacketNotNull("Upload fail", testUpload(packet, filter));
+    }
+
+    public byte[] verifyDownload(final ByteBuffer packet, final Predicate<byte[]> filter)
+            throws Exception {
+        sendDownloadPacket(packet);
+
+        return verifyPacketNotNull("Download fail", getDownloadPacket(filter));
     }
 }
diff --git a/Tethering/tests/privileged/src/com/android/networkstack/tethering/ConntrackSocketTest.java b/Tethering/tests/privileged/src/com/android/networkstack/tethering/ConntrackSocketTest.java
index 7ee69b2..d38a7c3 100644
--- a/Tethering/tests/privileged/src/com/android/networkstack/tethering/ConntrackSocketTest.java
+++ b/Tethering/tests/privileged/src/com/android/networkstack/tethering/ConntrackSocketTest.java
@@ -28,7 +28,6 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
@@ -38,6 +37,7 @@
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.netlink.StructNlMsgHdr;
 
 import org.junit.Before;
diff --git a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
index aac531a..f242227 100644
--- a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
+++ b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
@@ -83,10 +83,7 @@
 import android.net.dhcp.IDhcpEventCallbacks;
 import android.net.dhcp.IDhcpServer;
 import android.net.dhcp.IDhcpServerCallbacks;
-import android.net.ip.IpNeighborMonitor.NeighborEvent;
-import android.net.ip.IpNeighborMonitor.NeighborEventConsumer;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
-import android.net.util.SharedLog;
 import android.os.Build;
 import android.os.Handler;
 import android.os.RemoteException;
@@ -101,10 +98,15 @@
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetworkStackConstants;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsKey;
 import com.android.net.module.util.bpf.TetherStatsValue;
+import com.android.net.module.util.ip.ConntrackMonitor;
+import com.android.net.module.util.ip.IpNeighborMonitor;
+import com.android.net.module.util.ip.IpNeighborMonitor.NeighborEvent;
+import com.android.net.module.util.ip.IpNeighborMonitor.NeighborEventConsumer;
 import com.android.networkstack.tethering.BpfCoordinator;
 import com.android.networkstack.tethering.BpfCoordinator.Ipv6ForwardingRule;
 import com.android.networkstack.tethering.PrivateAddressCoordinator;
@@ -116,6 +118,7 @@
 import com.android.networkstack.tethering.TetherLimitValue;
 import com.android.networkstack.tethering.TetherUpstream6Key;
 import com.android.networkstack.tethering.TetheringConfiguration;
+import com.android.networkstack.tethering.metrics.TetheringMetrics;
 import com.android.networkstack.tethering.util.InterfaceSet;
 import com.android.networkstack.tethering.util.PrefixUtils;
 import com.android.testutils.DevSdkIgnoreRule;
@@ -186,6 +189,7 @@
     @Mock private NetworkStatsManager mStatsManager;
     @Mock private TetheringConfiguration mTetherConfig;
     @Mock private ConntrackMonitor mConntrackMonitor;
+    @Mock private TetheringMetrics mTetheringMetrics;
     @Mock private BpfMap<Tether4Key, Tether4Value> mBpfDownstream4Map;
     @Mock private BpfMap<Tether4Key, Tether4Value> mBpfUpstream4Map;
     @Mock private BpfMap<TetherDownstream6Key, Tether6Value> mBpfDownstream6Map;
@@ -235,7 +239,7 @@
         when(mTetherConfig.getP2pLeasesSubnetPrefixLength()).thenReturn(P2P_SUBNET_PREFIX_LENGTH);
         mIpServer = new IpServer(
                 IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog, mNetd, mBpfCoordinator,
-                mCallback, mTetherConfig, mAddressCoordinator, mDependencies);
+                mCallback, mTetherConfig, mAddressCoordinator, mTetheringMetrics, mDependencies);
         mIpServer.start();
         mNeighborEventConsumer = neighborCaptor.getValue();
 
@@ -367,7 +371,7 @@
                 .thenReturn(mIpNeighborMonitor);
         mIpServer = new IpServer(IFACE_NAME, mLooper.getLooper(), TETHERING_BLUETOOTH, mSharedLog,
                 mNetd, mBpfCoordinator, mCallback, mTetherConfig, mAddressCoordinator,
-                mDependencies);
+                mTetheringMetrics, mDependencies);
         mIpServer.start();
         mLooper.dispatchAll();
         verify(mCallback).updateInterfaceState(
@@ -451,6 +455,9 @@
                 mIpServer, STATE_AVAILABLE, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), any(LinkProperties.class));
+        verify(mTetheringMetrics).updateErrorCode(eq(TETHERING_BLUETOOTH),
+                eq(TETHER_ERROR_NO_ERROR));
+        verify(mTetheringMetrics).sendReport(eq(TETHERING_BLUETOOTH));
         verifyNoMoreInteractions(mNetd, mCallback, mAddressCoordinator);
     }
 
@@ -658,6 +665,9 @@
         usbTeardownOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), mLinkPropertiesCaptor.capture());
         assertNoAddressesNorRoutes(mLinkPropertiesCaptor.getValue());
+        verify(mTetheringMetrics).updateErrorCode(eq(TETHERING_USB),
+                eq(TETHER_ERROR_TETHER_IFACE_ERROR));
+        verify(mTetheringMetrics).sendReport(eq(TETHERING_USB));
     }
 
     @Test
@@ -676,6 +686,9 @@
         usbTeardownOrder.verify(mCallback).updateLinkProperties(
                 eq(mIpServer), mLinkPropertiesCaptor.capture());
         assertNoAddressesNorRoutes(mLinkPropertiesCaptor.getValue());
+        verify(mTetheringMetrics).updateErrorCode(eq(TETHERING_USB),
+                eq(TETHER_ERROR_ENABLE_FORWARDING_ERROR));
+        verify(mTetheringMetrics).sendReport(eq(TETHERING_USB));
     }
 
     @Test
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
index 3630f24..fa1d881 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
@@ -23,7 +23,6 @@
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkStats.UID_TETHERING;
-import static android.net.ip.ConntrackMonitor.ConntrackEvent;
 import static android.net.netstats.provider.NetworkStatsProvider.QUOTA_UNLIMITED;
 import static android.system.OsConstants.ETH_P_IP;
 import static android.system.OsConstants.ETH_P_IPV6;
@@ -33,6 +32,7 @@
 
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.staticMockMarker;
+import static com.android.net.module.util.ip.ConntrackMonitor.ConntrackEvent;
 import static com.android.net.module.util.netlink.ConntrackMessage.DYING_MASK;
 import static com.android.net.module.util.netlink.ConntrackMessage.ESTABLISHED_MASK;
 import static com.android.net.module.util.netlink.ConntrackMessage.Tuple;
@@ -82,10 +82,7 @@
 import android.net.NetworkStats;
 import android.net.TetherOffloadRuleParcel;
 import android.net.TetherStatsParcel;
-import android.net.ip.ConntrackMonitor;
-import android.net.ip.ConntrackMonitor.ConntrackEventConsumer;
 import android.net.ip.IpServer;
-import android.net.util.SharedLog;
 import android.os.Build;
 import android.os.Handler;
 import android.os.test.TestLooper;
@@ -100,10 +97,13 @@
 import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetworkStackConstants;
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.bpf.Tether4Key;
 import com.android.net.module.util.bpf.Tether4Value;
 import com.android.net.module.util.bpf.TetherStatsKey;
 import com.android.net.module.util.bpf.TetherStatsValue;
+import com.android.net.module.util.ip.ConntrackMonitor;
+import com.android.net.module.util.ip.ConntrackMonitor.ConntrackEventConsumer;
 import com.android.net.module.util.netlink.ConntrackMessage;
 import com.android.net.module.util.netlink.NetlinkConstants;
 import com.android.net.module.util.netlink.NetlinkSocket;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
index 01d7b4b..e4263db 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/EntitlementManagerTest.java
@@ -65,7 +65,6 @@
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.Resources;
-import android.net.util.SharedLog;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.PersistableBundle;
@@ -82,6 +81,7 @@
 
 import com.android.internal.util.test.BroadcastInterceptingContext;
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.SharedLog;
 import com.android.testutils.DevSdkIgnoreRule;
 
 import org.junit.After;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/FakeTetheringConfiguration.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/FakeTetheringConfiguration.java
index ac5c59d..95ec38f 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/FakeTetheringConfiguration.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/FakeTetheringConfiguration.java
@@ -18,7 +18,8 @@
 
 import android.content.Context;
 import android.content.res.Resources;
-import android.net.util.SharedLog;
+
+import com.android.net.module.util.SharedLog;
 
 /** FakeTetheringConfiguration is used to override static method for testing. */
 public class FakeTetheringConfiguration extends TetheringConfiguration {
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/IPv6TetheringCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/IPv6TetheringCoordinatorTest.java
index f2b5314..865228a 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/IPv6TetheringCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/IPv6TetheringCoordinatorTest.java
@@ -41,11 +41,12 @@
 import android.net.NetworkCapabilities;
 import android.net.RouteInfo;
 import android.net.ip.IpServer;
-import android.net.util.SharedLog;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.net.module.util.SharedLog;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadControllerTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadControllerTest.java
index e9716b3..faca1c8 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadControllerTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadControllerTest.java
@@ -26,6 +26,7 @@
 import static android.net.RouteInfo.RTN_UNICAST;
 import static android.provider.Settings.Global.TETHER_OFFLOAD_DISABLED;
 
+import static com.android.modules.utils.build.SdkLevel.isAtLeastS;
 import static com.android.modules.utils.build.SdkLevel.isAtLeastT;
 import static com.android.networkstack.tethering.OffloadController.StatsType.STATS_PER_IFACE;
 import static com.android.networkstack.tethering.OffloadController.StatsType.STATS_PER_UID;
@@ -66,7 +67,6 @@
 import android.net.NetworkStats.Entry;
 import android.net.RouteInfo;
 import android.net.netstats.provider.NetworkStatsProvider;
-import android.net.util.SharedLog;
 import android.os.Build;
 import android.os.Handler;
 import android.os.test.TestLooper;
@@ -78,6 +78,7 @@
 import androidx.test.runner.AndroidJUnit4;
 
 import com.android.internal.util.test.FakeSettingsProvider;
+import com.android.net.module.util.SharedLog;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.TestableNetworkStatsProviderCbBinder;
@@ -668,7 +669,7 @@
 
         if (isAtLeastT()) {
             mTetherStatsProviderCb.expectNotifyLimitReached();
-        } else if (Build.VERSION.SDK_INT == Build.VERSION_CODES.S) {
+        } else if (isAtLeastS()) {
             mTetherStatsProviderCb.expectNotifyWarningOrLimitReached();
         } else {
             mTetherStatsProviderCb.expectNotifyLimitReached();
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadHardwareInterfaceTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadHardwareInterfaceTest.java
index d1891ed..36b439b 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadHardwareInterfaceTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/OffloadHardwareInterfaceTest.java
@@ -43,7 +43,6 @@
 import android.hardware.tetheroffload.control.V1_0.NetworkProtocol;
 import android.hardware.tetheroffload.control.V1_1.ITetheringOffloadCallback;
 import android.hardware.tetheroffload.control.V1_1.OffloadCallbackEvent;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.NativeHandle;
 import android.os.test.TestLooper;
@@ -55,6 +54,7 @@
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.net.module.util.SharedLog;
 import com.android.net.module.util.netlink.StructNfGenMsg;
 import com.android.net.module.util.netlink.StructNlMsgHdr;
 
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
index 3190f35..1a12125 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringConfigurationTest.java
@@ -47,7 +47,6 @@
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.Resources;
-import android.net.util.SharedLog;
 import android.os.Build;
 import android.os.PersistableBundle;
 import android.provider.DeviceConfig;
@@ -63,6 +62,7 @@
 import com.android.internal.util.test.FakeSettingsProvider;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.DeviceConfigUtils;
+import com.android.net.module.util.SharedLog;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringServiceTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringServiceTest.java
index f664d5d..9db8f16 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringServiceTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringServiceTest.java
@@ -275,7 +275,7 @@
         mTetheringConnector.startTethering(request, TEST_CALLER_PKG, TEST_ATTRIBUTION_TAG,
                 result);
         verify(mTethering).isTetheringSupported();
-        verify(mTethering).startTethering(eq(request), eq(result));
+        verify(mTethering).startTethering(eq(request), eq(TEST_CALLER_PKG), eq(result));
     }
 
     @Test
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
index 6ef0e24..b402bc3 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
@@ -45,6 +45,7 @@
 import static android.net.TetheringManager.TETHERING_WIFI;
 import static android.net.TetheringManager.TETHERING_WIFI_P2P;
 import static android.net.TetheringManager.TETHER_ERROR_IFACE_CFG_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_INTERNAL_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_SERVICE_UNAVAIL;
 import static android.net.TetheringManager.TETHER_ERROR_UNKNOWN_IFACE;
@@ -143,7 +144,6 @@
 import android.net.TetheringCallbackStartedParcel;
 import android.net.TetheringConfigurationParcel;
 import android.net.TetheringInterface;
-import android.net.TetheringManager;
 import android.net.TetheringRequestParcel;
 import android.net.dhcp.DhcpLeaseParcelable;
 import android.net.dhcp.DhcpServerCallbacks;
@@ -151,11 +151,9 @@
 import android.net.dhcp.IDhcpEventCallbacks;
 import android.net.dhcp.IDhcpServer;
 import android.net.ip.DadProxy;
-import android.net.ip.IpNeighborMonitor;
 import android.net.ip.IpServer;
 import android.net.ip.RouterAdvertisementDaemon;
 import android.net.util.NetworkConstants;
-import android.net.util.SharedLog;
 import android.net.wifi.SoftApConfiguration;
 import android.net.wifi.WifiClient;
 import android.net.wifi.WifiManager;
@@ -177,7 +175,6 @@
 import android.telephony.PhoneStateListener;
 import android.telephony.TelephonyManager;
 import android.test.mock.MockContentResolver;
-import android.util.ArraySet;
 
 import androidx.annotation.NonNull;
 import androidx.test.filters.SmallTest;
@@ -188,16 +185,22 @@
 import com.android.internal.util.test.FakeSettingsProvider;
 import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.InterfaceParams;
+import com.android.net.module.util.SharedLog;
+import com.android.net.module.util.ip.IpNeighborMonitor;
 import com.android.networkstack.apishim.common.BluetoothPanShim;
 import com.android.networkstack.apishim.common.BluetoothPanShim.TetheredInterfaceCallbackShim;
 import com.android.networkstack.apishim.common.BluetoothPanShim.TetheredInterfaceRequestShim;
 import com.android.networkstack.apishim.common.UnsupportedApiLevelException;
 import com.android.networkstack.tethering.TestConnectivityManager.TestNetworkAgent;
+import com.android.networkstack.tethering.metrics.TetheringMetrics;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.MiscAsserts;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
@@ -214,12 +217,13 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-import java.util.Set;
 import java.util.Vector;
 
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class TetheringTest {
+    @Rule public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
+
     private static final int IFINDEX_OFFSET = 100;
 
     private static final String TEST_MOBILE_IFNAME = "test_rmnet_data0";
@@ -240,6 +244,7 @@
     private static final String TEST_WIFI_REGEX = "test_wlan\\d";
     private static final String TEST_P2P_REGEX = "test_p2p-p2p\\d-.*";
     private static final String TEST_BT_REGEX = "test_pan\\d";
+    private static final String TEST_CALLER_PKG = "com.test.tethering";
 
     private static final int CELLULAR_NETID = 100;
     private static final int WIFI_NETID = 101;
@@ -274,6 +279,7 @@
     @Mock private BluetoothPan mBluetoothPan;
     @Mock private BluetoothPanShim mBluetoothPanShim;
     @Mock private TetheredInterfaceRequestShim mTetheredInterfaceRequestShim;
+    @Mock private TetheringMetrics mTetheringMetrics;
 
     private final MockIpServerDependencies mIpServerDependencies =
             spy(new MockIpServerDependencies());
@@ -297,6 +303,7 @@
     private OffloadController mOffloadCtrl;
     private PrivateAddressCoordinator mPrivateAddressCoordinator;
     private SoftApCallback mSoftApCallback;
+    private SoftApCallback mLocalOnlyHotspotCallback;
     private UpstreamNetworkMonitor mUpstreamNetworkMonitor;
     private TetheredInterfaceCallbackShim mTetheredInterfaceCallbackShim;
 
@@ -498,6 +505,11 @@
         }
 
         @Override
+        public TetheringMetrics getTetheringMetrics() {
+            return mTetheringMetrics;
+        }
+
+        @Override
         public PrivateAddressCoordinator getPrivateAddressCoordinator(Context ctx,
                 TetheringConfiguration cfg) {
             mPrivateAddressCoordinator = super.getPrivateAddressCoordinator(ctx, cfg);
@@ -662,6 +674,14 @@
         verify(mWifiManager).registerSoftApCallback(any(), softApCallbackCaptor.capture());
         mSoftApCallback = softApCallbackCaptor.getValue();
 
+        if (isAtLeastT()) {
+            final ArgumentCaptor<SoftApCallback> localOnlyCallbackCaptor =
+                    ArgumentCaptor.forClass(SoftApCallback.class);
+            verify(mWifiManager).registerLocalOnlyHotspotSoftApCallback(any(),
+                    localOnlyCallbackCaptor.capture());
+            mLocalOnlyHotspotCallback = localOnlyCallbackCaptor.getValue();
+        }
+
         when(mPackageManager.hasSystemFeature(PackageManager.FEATURE_WIFI)).thenReturn(true);
         when(mPackageManager.hasSystemFeature(PackageManager.FEATURE_WIFI_DIRECT)).thenReturn(true);
     }
@@ -856,7 +876,8 @@
 
     private void prepareNcmTethering() {
         // Emulate startTethering(TETHERING_NCM) called
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_NCM), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_NCM), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verify(mUsbManager, times(1)).setCurrentFunctions(UsbManager.FUNCTION_NCM);
     }
@@ -864,7 +885,7 @@
     private void prepareUsbTethering() {
         // Emulate pressing the USB tethering button in Settings UI.
         final TetheringRequestParcel request = createTetheringRequestParcel(TETHERING_USB);
-        mTethering.startTethering(request, null);
+        mTethering.startTethering(request, TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
 
         assertEquals(1, mTethering.getActiveTetheringRequests().size());
@@ -1434,7 +1455,8 @@
         when(mWifiManager.startTetheredHotspot(any(SoftApConfiguration.class))).thenReturn(true);
 
         // Emulate pressing the WiFi tethering button.
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startTetheredHotspot(null);
         verifyNoMoreInteractions(mWifiManager);
@@ -1461,7 +1483,8 @@
         when(mWifiManager.startTetheredHotspot(any(SoftApConfiguration.class))).thenReturn(true);
 
         // Emulate pressing the WiFi tethering button.
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startTetheredHotspot(null);
         verifyNoMoreInteractions(mWifiManager);
@@ -1537,11 +1560,13 @@
         doThrow(new RemoteException()).when(mNetd).ipfwdEnableForwarding(TETHERING_NAME);
 
         // Emulate pressing the WiFi tethering button.
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verify(mWifiManager, times(1)).startTetheredHotspot(null);
         verifyNoMoreInteractions(mWifiManager);
         verifyNoMoreInteractions(mNetd);
+        verify(mTetheringMetrics).createBuilder(eq(TETHERING_WIFI), anyString());
 
         // Emulate externally-visible WifiManager effects, causing the
         // per-interface state machine to start up, and telling us that
@@ -1580,6 +1605,10 @@
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_CONFIGURATION_ERROR);
 
+        verify(mTetheringMetrics, times(2)).updateErrorCode(eq(TETHERING_WIFI),
+                eq(TETHER_ERROR_INTERNAL_ERROR));
+        verify(mTetheringMetrics, times(2)).sendReport(eq(TETHERING_WIFI));
+
         verifyNoMoreInteractions(mWifiManager);
         verifyNoMoreInteractions(mNetd);
     }
@@ -1700,7 +1729,6 @@
         private final ArrayList<TetherStatesParcel> mTetherStates = new ArrayList<>();
         private final ArrayList<Integer> mOffloadStatus = new ArrayList<>();
         private final ArrayList<List<TetheredClient>> mTetheredClients = new ArrayList<>();
-        private final ArrayList<Long> mSupportedBitmaps = new ArrayList<>();
 
         // This function will remove the recorded callbacks, so it must be called once for
         // each callback. If this is called after multiple callback, the order matters.
@@ -1753,10 +1781,6 @@
             assertTrue(leases.containsAll(result));
         }
 
-        public void expectSupportedTetheringTypes(Set<Integer> expectedTypes) {
-            assertEquals(expectedTypes, TetheringManager.unpackBits(mSupportedBitmaps.remove(0)));
-        }
-
         @Override
         public void onUpstreamChanged(Network network) {
             mActualUpstreams.add(network);
@@ -1789,17 +1813,11 @@
             mTetherStates.add(parcel.states);
             mOffloadStatus.add(parcel.offloadStatus);
             mTetheredClients.add(parcel.tetheredClients);
-            mSupportedBitmaps.add(parcel.supportedTypes);
         }
 
         @Override
         public void onCallbackStopped(int errorCode) { }
 
-        @Override
-        public void onSupportedTetheringTypes(long supportedBitmap) {
-            mSupportedBitmaps.add(supportedBitmap);
-        }
-
         public void assertNoUpstreamChangeCallback() {
             assertTrue(mActualUpstreams.isEmpty());
         }
@@ -1882,7 +1900,8 @@
         tetherState = callback.pollTetherStatesChanged();
         assertArrayEquals(tetherState.availableList, new TetheringInterface[] {wifiIface});
 
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_WIFI), TEST_CALLER_PKG,
+                null);
         sendWifiApStateChanged(WIFI_AP_STATE_ENABLED, TEST_WLAN_IFNAME, IFACE_IP_MODE_TETHERED);
         tetherState = callback.pollTetherStatesChanged();
         assertArrayEquals(tetherState.tetheredList, new TetheringInterface[] {wifiIface});
@@ -1985,10 +2004,12 @@
     public void testNoDuplicatedEthernetRequest() throws Exception {
         final TetheredInterfaceRequest mockRequest = mock(TetheredInterfaceRequest.class);
         when(mEm.requestTetheredInterface(any(), any())).thenReturn(mockRequest);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verify(mEm, times(1)).requestTetheredInterface(any(), any());
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET), TEST_CALLER_PKG,
+                null);
         mLooper.dispatchAll();
         verifyNoMoreInteractions(mEm);
         mTethering.stopTethering(TETHERING_ETHERNET);
@@ -2192,14 +2213,16 @@
         final ResultListener thirdResult = new ResultListener(TETHER_ERROR_NO_ERROR);
 
         // Enable USB tethering and check that Tethering starts USB.
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB), firstResult);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB), TEST_CALLER_PKG,
+                firstResult);
         mLooper.dispatchAll();
         firstResult.assertHasResult();
         verify(mUsbManager, times(1)).setCurrentFunctions(UsbManager.FUNCTION_RNDIS);
         verifyNoMoreInteractions(mUsbManager);
 
         // Enable USB tethering again with the same request and expect no change to USB.
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB), secondResult);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB), TEST_CALLER_PKG,
+                secondResult);
         mLooper.dispatchAll();
         secondResult.assertHasResult();
         verify(mUsbManager, never()).setCurrentFunctions(UsbManager.FUNCTION_NONE);
@@ -2208,7 +2231,8 @@
         // Enable USB tethering with a different request and expect that USB is stopped and
         // started.
         mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB,
-                  serverLinkAddr, clientLinkAddr, false, CONNECTIVITY_SCOPE_GLOBAL), thirdResult);
+                  serverLinkAddr, clientLinkAddr, false, CONNECTIVITY_SCOPE_GLOBAL),
+                  TEST_CALLER_PKG, thirdResult);
         mLooper.dispatchAll();
         thirdResult.assertHasResult();
         verify(mUsbManager, times(1)).setCurrentFunctions(UsbManager.FUNCTION_NONE);
@@ -2237,7 +2261,8 @@
         final ArgumentCaptor<DhcpServingParamsParcel> dhcpParamsCaptor =
                 ArgumentCaptor.forClass(DhcpServingParamsParcel.class);
         mTethering.startTethering(createTetheringRequestParcel(TETHERING_USB,
-                  serverLinkAddr, clientLinkAddr, false, CONNECTIVITY_SCOPE_GLOBAL), null);
+                  serverLinkAddr, clientLinkAddr, false, CONNECTIVITY_SCOPE_GLOBAL),
+                  TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mUsbManager, times(1)).setCurrentFunctions(UsbManager.FUNCTION_NCM);
         mTethering.interfaceStatusChanged(TEST_NCM_IFNAME, true);
@@ -2305,7 +2330,7 @@
         final TetheringRequestParcel wifiNotExemptRequest =
                 createTetheringRequestParcel(TETHERING_WIFI, null, null, false,
                         CONNECTIVITY_SCOPE_GLOBAL);
-        mTethering.startTethering(wifiNotExemptRequest, null);
+        mTethering.startTethering(wifiNotExemptRequest, TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mEntitleMgr).startProvisioningIfNeeded(TETHERING_WIFI, false);
         verify(mEntitleMgr, never()).setExemptedDownstreamType(TETHERING_WIFI);
@@ -2319,7 +2344,7 @@
         final TetheringRequestParcel wifiExemptRequest =
                 createTetheringRequestParcel(TETHERING_WIFI, null, null, true,
                         CONNECTIVITY_SCOPE_GLOBAL);
-        mTethering.startTethering(wifiExemptRequest, null);
+        mTethering.startTethering(wifiExemptRequest, TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mEntitleMgr, never()).startProvisioningIfNeeded(TETHERING_WIFI, false);
         verify(mEntitleMgr).setExemptedDownstreamType(TETHERING_WIFI);
@@ -2332,14 +2357,14 @@
         // If one app enables tethering without provisioning check first, then another app enables
         // tethering of the same type but does not disable the provisioning check.
         setupForRequiredProvisioning();
-        mTethering.startTethering(wifiExemptRequest, null);
+        mTethering.startTethering(wifiExemptRequest, TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mEntitleMgr, never()).startProvisioningIfNeeded(TETHERING_WIFI, false);
         verify(mEntitleMgr).setExemptedDownstreamType(TETHERING_WIFI);
         assertTrue(mEntitleMgr.isCellularUpstreamPermitted());
         reset(mEntitleMgr);
         setupForRequiredProvisioning();
-        mTethering.startTethering(wifiNotExemptRequest, null);
+        mTethering.startTethering(wifiNotExemptRequest, TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mEntitleMgr).startProvisioningIfNeeded(TETHERING_WIFI, false);
         verify(mEntitleMgr, never()).setExemptedDownstreamType(TETHERING_WIFI);
@@ -2429,7 +2454,8 @@
         when(mEm.requestTetheredInterface(any(), any())).thenReturn(mockRequest);
         final ArgumentCaptor<TetheredInterfaceCallback> callbackCaptor =
                 ArgumentCaptor.forClass(TetheredInterfaceCallback.class);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET), null);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_ETHERNET),
+                TEST_CALLER_PKG, null);
         mLooper.dispatchAll();
         verify(mEm).requestTetheredInterface(any(), callbackCaptor.capture());
         TetheredInterfaceCallback ethCallback = callbackCaptor.getValue();
@@ -2511,12 +2537,11 @@
         eventCallbacks = dhcpEventCbsCaptor.getValue();
         // Update lease for local only tethering.
         final MacAddress testMac1 = MacAddress.fromString("11:11:11:11:11:11");
-        final ArrayList<DhcpLeaseParcelable> p2pLeases = new ArrayList<>();
-        p2pLeases.add(createDhcpLeaseParcelable("clientId1", testMac1, "192.168.50.24", 24,
-                Long.MAX_VALUE, "test1"));
-        notifyDhcpLeasesChanged(p2pLeases, eventCallbacks);
-        final List<TetheredClient> clients = toTetheredClients(p2pLeases, TETHERING_WIFI_P2P);
-        callback.expectTetheredClientChanged(clients);
+        final DhcpLeaseParcelable p2pLease = createDhcpLeaseParcelable("clientId1", testMac1,
+                "192.168.50.24", 24, Long.MAX_VALUE, "test1");
+        final List<TetheredClient> p2pClients = notifyDhcpLeasesChanged(TETHERING_WIFI_P2P,
+                eventCallbacks, p2pLease);
+        callback.expectTetheredClientChanged(p2pClients);
         reset(mDhcpServer);
 
         // Run wifi tethering.
@@ -2526,25 +2551,20 @@
                 any(), dhcpEventCbsCaptor.capture());
         eventCallbacks = dhcpEventCbsCaptor.getValue();
         // Update mac address from softAp callback before getting dhcp lease.
-        final ArrayList<WifiClient> wifiClients = new ArrayList<>();
         final MacAddress testMac2 = MacAddress.fromString("22:22:22:22:22:22");
-        final WifiClient testClient = mock(WifiClient.class);
-        when(testClient.getMacAddress()).thenReturn(testMac2);
-        wifiClients.add(testClient);
-        mSoftApCallback.onConnectedClientsChanged(wifiClients);
-        final TetheredClient noAddrClient = new TetheredClient(testMac2,
-                Collections.emptyList() /* addresses */, TETHERING_WIFI);
-        clients.add(noAddrClient);
-        callback.expectTetheredClientChanged(clients);
+        final TetheredClient noAddrClient = notifyConnectedWifiClientsChanged(testMac2,
+                false /* isLocalOnly */);
+        final List<TetheredClient> p2pAndNoAddrClients = new ArrayList<>(p2pClients);
+        p2pAndNoAddrClients.add(noAddrClient);
+        callback.expectTetheredClientChanged(p2pAndNoAddrClients);
 
         // Update dhcp lease for wifi tethering.
-        clients.remove(noAddrClient);
-        final ArrayList<DhcpLeaseParcelable> wifiLeases = new ArrayList<>();
-        wifiLeases.add(createDhcpLeaseParcelable("clientId2", testMac2, "192.168.43.24", 24,
-                Long.MAX_VALUE, "test2"));
-        notifyDhcpLeasesChanged(wifiLeases, eventCallbacks);
-        clients.addAll(toTetheredClients(wifiLeases, TETHERING_WIFI));
-        callback.expectTetheredClientChanged(clients);
+        final DhcpLeaseParcelable wifiLease = createDhcpLeaseParcelable("clientId2", testMac2,
+                "192.168.43.24", 24, Long.MAX_VALUE, "test2");
+        final List<TetheredClient> p2pAndWifiClients = new ArrayList<>(p2pClients);
+        p2pAndWifiClients.addAll(notifyDhcpLeasesChanged(TETHERING_WIFI,
+                eventCallbacks, wifiLease));
+        callback.expectTetheredClientChanged(p2pAndWifiClients);
 
         // Test onStarted callback that register second callback when tethering is running.
         TestTetheringEventCallback callback2 = new TestTetheringEventCallback();
@@ -2552,18 +2572,74 @@
             mTethering.registerTetheringEventCallback(callback2);
             mLooper.dispatchAll();
         });
-        callback2.expectTetheredClientChanged(clients);
+        callback2.expectTetheredClientChanged(p2pAndWifiClients);
     }
 
-    private void notifyDhcpLeasesChanged(List<DhcpLeaseParcelable> leaseParcelables,
-            IDhcpEventCallbacks callback) throws Exception {
-        callback.onLeasesChanged(leaseParcelables);
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testUpdateConnectedClientsForLocalOnlyHotspot() throws Exception {
+        TestTetheringEventCallback callback = new TestTetheringEventCallback();
+        runAsShell(NETWORK_SETTINGS, () -> {
+            mTethering.registerTetheringEventCallback(callback);
+            mLooper.dispatchAll();
+        });
+        callback.expectTetheredClientChanged(Collections.emptyList());
+
+        // Run local only hotspot.
+        mTethering.interfaceStatusChanged(TEST_WLAN_IFNAME, true);
+        sendWifiApStateChanged(WIFI_AP_STATE_ENABLED, TEST_WLAN_IFNAME, IFACE_IP_MODE_LOCAL_ONLY);
+
+        final ArgumentCaptor<IDhcpEventCallbacks> dhcpEventCbsCaptor =
+                 ArgumentCaptor.forClass(IDhcpEventCallbacks.class);
+        verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS)).startWithCallbacks(
+                any(), dhcpEventCbsCaptor.capture());
+        final IDhcpEventCallbacks eventCallbacks = dhcpEventCbsCaptor.getValue();
+        // Update mac address from softAp callback before getting dhcp lease.
+        final MacAddress testMac = MacAddress.fromString("22:22:22:22:22:22");
+        final TetheredClient noAddrClient = notifyConnectedWifiClientsChanged(testMac,
+                true /* isLocalOnly */);
+        final List<TetheredClient> noAddrLocalOnlyClients = new ArrayList<>();
+        noAddrLocalOnlyClients.add(noAddrClient);
+        callback.expectTetheredClientChanged(noAddrLocalOnlyClients);
+
+        // Update dhcp lease for local only hotspot.
+        final DhcpLeaseParcelable wifiLease = createDhcpLeaseParcelable("clientId", testMac,
+                "192.168.43.24", 24, Long.MAX_VALUE, "test");
+        final List<TetheredClient> localOnlyClients = notifyDhcpLeasesChanged(TETHERING_WIFI,
+                eventCallbacks, wifiLease);
+        callback.expectTetheredClientChanged(localOnlyClients);
+
+        // Client disconnect from local only hotspot.
+        mLocalOnlyHotspotCallback.onConnectedClientsChanged(Collections.emptyList());
+        callback.expectTetheredClientChanged(Collections.emptyList());
+    }
+
+    private TetheredClient notifyConnectedWifiClientsChanged(final MacAddress mac,
+            boolean isLocalOnly) throws Exception {
+        final ArrayList<WifiClient> wifiClients = new ArrayList<>();
+        final WifiClient testClient = mock(WifiClient.class);
+        when(testClient.getMacAddress()).thenReturn(mac);
+        wifiClients.add(testClient);
+        if (isLocalOnly) {
+            mLocalOnlyHotspotCallback.onConnectedClientsChanged(wifiClients);
+        } else {
+            mSoftApCallback.onConnectedClientsChanged(wifiClients);
+        }
+        return new TetheredClient(mac, Collections.emptyList() /* addresses */, TETHERING_WIFI);
+    }
+
+    private List<TetheredClient> notifyDhcpLeasesChanged(int type, IDhcpEventCallbacks callback,
+            DhcpLeaseParcelable... leases) throws Exception {
+        final List<DhcpLeaseParcelable> dhcpLeases = Arrays.asList(leases);
+        callback.onLeasesChanged(dhcpLeases);
         mLooper.dispatchAll();
+
+        return toTetheredClients(dhcpLeases, type);
     }
 
     private List<TetheredClient> toTetheredClients(List<DhcpLeaseParcelable> leaseParcelables,
             int type) throws Exception {
-        final ArrayList<TetheredClient> leases = new ArrayList<>();
+        final ArrayList<TetheredClient> clients = new ArrayList<>();
         for (DhcpLeaseParcelable lease : leaseParcelables) {
             final LinkAddress address = new LinkAddress(
                     intToInet4AddressHTH(lease.netAddr), lease.prefixLength,
@@ -2573,13 +2649,13 @@
             final MacAddress macAddress = MacAddress.fromBytes(lease.hwAddr);
 
             final AddressInfo addressInfo = new TetheredClient.AddressInfo(address, lease.hostname);
-            leases.add(new TetheredClient(
+            clients.add(new TetheredClient(
                     macAddress,
                     Collections.singletonList(addressInfo),
                     type));
         }
 
-        return leases;
+        return clients;
     }
 
     private DhcpLeaseParcelable createDhcpLeaseParcelable(final String clientId,
@@ -2604,7 +2680,8 @@
 
         final ResultListener result = new ResultListener(TETHER_ERROR_NO_ERROR);
         mockBluetoothSettings(true /* bluetoothOn */, true /* tetheringOn */);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH), result);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH),
+                TEST_CALLER_PKG, result);
         mLooper.dispatchAll();
         verifySetBluetoothTethering(true /* enable */, true /* bindToPanService */);
         result.assertHasResult();
@@ -2639,7 +2716,8 @@
 
         final ResultListener result = new ResultListener(TETHER_ERROR_NO_ERROR);
         mockBluetoothSettings(true /* bluetoothOn */, true /* tetheringOn */);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH), result);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH),
+                TEST_CALLER_PKG, result);
         mLooper.dispatchAll();
         verifySetBluetoothTethering(true /* enable */, true /* bindToPanService */);
         result.assertHasResult();
@@ -2660,7 +2738,8 @@
         // already bound.
         mockBluetoothSettings(true /* bluetoothOn */, true /* tetheringOn */);
         final ResultListener secondResult = new ResultListener(TETHER_ERROR_NO_ERROR);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH), secondResult);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH),
+                TEST_CALLER_PKG, secondResult);
         mLooper.dispatchAll();
         verifySetBluetoothTethering(true /* enable */, false /* bindToPanService */);
         secondResult.assertHasResult();
@@ -2681,7 +2760,8 @@
     public void testBluetoothServiceDisconnects() throws Exception {
         final ResultListener result = new ResultListener(TETHER_ERROR_NO_ERROR);
         mockBluetoothSettings(true /* bluetoothOn */, true /* tetheringOn */);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH), result);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_BLUETOOTH),
+                TEST_CALLER_PKG, result);
         mLooper.dispatchAll();
         ServiceListener panListener = verifySetBluetoothTethering(true /* enable */,
                 true /* bindToPanService */);
@@ -2832,18 +2912,26 @@
         runNcmTethering();
         verify(mDhcpServer, timeout(DHCPSERVER_START_TIMEOUT_MS).times(1)).startWithCallbacks(
                 any(), any());
+        verify(mTetheringMetrics).createBuilder(eq(TETHERING_NCM), anyString());
 
         // Change the USB tethering function to NCM. Because the USB tethering function was set to
         // RNDIS (the default), tethering is stopped.
         forceUsbTetheringUse(TETHER_USB_NCM_FUNCTION);
         verifyUsbTetheringStopDueToSettingChange(TEST_NCM_IFNAME);
+        verify(mTetheringMetrics).updateErrorCode(anyInt(), eq(TETHER_ERROR_NO_ERROR));
+        verify(mTetheringMetrics).sendReport(eq(TETHERING_NCM));
 
         // If TETHERING_USB is forced to use ncm function, TETHERING_NCM would no longer be
         // available.
         final ResultListener ncmResult = new ResultListener(TETHER_ERROR_SERVICE_UNAVAIL);
-        mTethering.startTethering(createTetheringRequestParcel(TETHERING_NCM), ncmResult);
+        mTethering.startTethering(createTetheringRequestParcel(TETHERING_NCM), TEST_CALLER_PKG,
+                ncmResult);
         mLooper.dispatchAll();
         ncmResult.assertHasResult();
+        verify(mTetheringMetrics, times(2)).createBuilder(eq(TETHERING_NCM), anyString());
+        verify(mTetheringMetrics).updateErrorCode(eq(TETHERING_NCM),
+                eq(TETHER_ERROR_SERVICE_UNAVAIL));
+        verify(mTetheringMetrics, times(2)).sendReport(eq(TETHERING_NCM));
 
         // Run TETHERING_USB with ncm configuration.
         runDualStackUsbTethering(TEST_NCM_IFNAME);
@@ -2857,81 +2945,53 @@
         runStopUSBTethering();
     }
 
-    public static ArraySet<Integer> getAllSupportedTetheringTypes() {
-        return new ArraySet<>(new Integer[] { TETHERING_USB, TETHERING_NCM, TETHERING_WIFI,
-                TETHERING_WIFI_P2P, TETHERING_BLUETOOTH, TETHERING_ETHERNET });
-    }
-
     @Test
     public void testTetheringSupported() throws Exception {
-        final ArraySet<Integer> expectedTypes = getAllSupportedTetheringTypes();
-        // Check tethering is supported after initialization.
         setTetheringSupported(true /* supported */);
-        TestTetheringEventCallback callback = new TestTetheringEventCallback();
-        mTethering.registerTetheringEventCallback(callback);
-        mLooper.dispatchAll();
-        updateConfigAndVerifySupported(callback, expectedTypes);
+        updateConfigAndVerifySupported(true /* supported */);
 
         // Could disable tethering supported by settings.
         Settings.Global.putInt(mContentResolver, Settings.Global.TETHER_SUPPORTED, 0);
-        updateConfigAndVerifySupported(callback, new ArraySet<>());
+        updateConfigAndVerifySupported(false /* supported */);
 
         // Could disable tethering supported by user restriction.
         setTetheringSupported(true /* supported */);
-        updateConfigAndVerifySupported(callback, expectedTypes);
         when(mUserManager.hasUserRestriction(
                 UserManager.DISALLOW_CONFIG_TETHERING)).thenReturn(true);
-        updateConfigAndVerifySupported(callback, new ArraySet<>());
+        updateConfigAndVerifySupported(false /* supported */);
 
         // Tethering is supported if it has any supported downstream.
         setTetheringSupported(true /* supported */);
-        updateConfigAndVerifySupported(callback, expectedTypes);
-        // Usb tethering is not supported:
-        expectedTypes.remove(TETHERING_USB);
         when(mResources.getStringArray(R.array.config_tether_usb_regexs))
                 .thenReturn(new String[0]);
-        updateConfigAndVerifySupported(callback, expectedTypes);
-        // Wifi tethering is not supported:
-        expectedTypes.remove(TETHERING_WIFI);
+        updateConfigAndVerifySupported(true /* supported */);
         when(mResources.getStringArray(R.array.config_tether_wifi_regexs))
                 .thenReturn(new String[0]);
-        updateConfigAndVerifySupported(callback, expectedTypes);
-        // Bluetooth tethering is not supported:
-        expectedTypes.remove(TETHERING_BLUETOOTH);
-        when(mResources.getStringArray(R.array.config_tether_bluetooth_regexs))
-                .thenReturn(new String[0]);
+        updateConfigAndVerifySupported(true /* supported */);
+
 
         if (isAtLeastT()) {
-            updateConfigAndVerifySupported(callback, expectedTypes);
-
-            // P2p tethering is not supported:
-            expectedTypes.remove(TETHERING_WIFI_P2P);
+            when(mResources.getStringArray(R.array.config_tether_bluetooth_regexs))
+                    .thenReturn(new String[0]);
+            updateConfigAndVerifySupported(true /* supported */);
             when(mResources.getStringArray(R.array.config_tether_wifi_p2p_regexs))
                     .thenReturn(new String[0]);
-            updateConfigAndVerifySupported(callback, expectedTypes);
-            // Ncm tethering is not supported:
-            expectedTypes.remove(TETHERING_NCM);
+            updateConfigAndVerifySupported(true /* supported */);
             when(mResources.getStringArray(R.array.config_tether_ncm_regexs))
                     .thenReturn(new String[0]);
-            updateConfigAndVerifySupported(callback, expectedTypes);
-            // Ethernet tethering (last supported type) is not supported:
-            expectedTypes.remove(TETHERING_ETHERNET);
+            updateConfigAndVerifySupported(true /* supported */);
             mForceEthernetServiceUnavailable = true;
-            updateConfigAndVerifySupported(callback, new ArraySet<>());
-
+            updateConfigAndVerifySupported(false /* supported */);
         } else {
-            // If wifi, usb and bluetooth are all not supported, all the types are not supported.
-            expectedTypes.clear();
-            updateConfigAndVerifySupported(callback, expectedTypes);
+            when(mResources.getStringArray(R.array.config_tether_bluetooth_regexs))
+                    .thenReturn(new String[0]);
+            updateConfigAndVerifySupported(false /* supported */);
         }
     }
 
-    private void updateConfigAndVerifySupported(final TestTetheringEventCallback callback,
-            final ArraySet<Integer> expectedTypes) {
+    private void updateConfigAndVerifySupported(boolean supported) {
         sendConfigurationChanged();
-
-        assertEquals(expectedTypes.size() > 0, mTethering.isTetheringSupported());
-        callback.expectSupportedTetheringTypes(expectedTypes);
+        assertEquals(supported, mTethering.isTetheringSupported());
     }
     // TODO: Test that a request for hotspot mode doesn't interfere with an
     // already operating tethering mode interface.
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/UpstreamNetworkMonitorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/UpstreamNetworkMonitorTest.java
index 97cebd8..9b9507b 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/UpstreamNetworkMonitorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/UpstreamNetworkMonitorTest.java
@@ -49,7 +49,6 @@
 import android.net.LinkProperties;
 import android.net.NetworkCapabilities;
 import android.net.NetworkRequest;
-import android.net.util.SharedLog;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
@@ -60,6 +59,7 @@
 
 import com.android.internal.util.State;
 import com.android.internal.util.StateMachine;
+import com.android.net.module.util.SharedLog;
 import com.android.networkstack.tethering.TestConnectivityManager.NetworkRequestInfo;
 import com.android.networkstack.tethering.TestConnectivityManager.TestNetworkAgent;
 
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/metrics/TetheringMetricsTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/metrics/TetheringMetricsTest.java
new file mode 100644
index 0000000..6a85718
--- /dev/null
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/metrics/TetheringMetricsTest.java
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.networkstack.tethering.metrics;
+
+import static android.net.TetheringManager.TETHERING_BLUETOOTH;
+import static android.net.TetheringManager.TETHERING_ETHERNET;
+import static android.net.TetheringManager.TETHERING_NCM;
+import static android.net.TetheringManager.TETHERING_USB;
+import static android.net.TetheringManager.TETHERING_WIFI;
+import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+import static android.net.TetheringManager.TETHER_ERROR_DHCPSERVER_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_DISABLE_FORWARDING_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_ENABLE_FORWARDING_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_ENTITLEMENT_UNKNOWN;
+import static android.net.TetheringManager.TETHER_ERROR_IFACE_CFG_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_INTERNAL_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION;
+import static android.net.TetheringManager.TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION;
+import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_PROVISIONING_FAILED;
+import static android.net.TetheringManager.TETHER_ERROR_SERVICE_UNAVAIL;
+import static android.net.TetheringManager.TETHER_ERROR_TETHER_IFACE_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_UNAVAIL_IFACE;
+import static android.net.TetheringManager.TETHER_ERROR_UNKNOWN_IFACE;
+import static android.net.TetheringManager.TETHER_ERROR_UNKNOWN_TYPE;
+import static android.net.TetheringManager.TETHER_ERROR_UNSUPPORTED;
+import static android.net.TetheringManager.TETHER_ERROR_UNTETHER_IFACE_ERROR;
+
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+
+import android.stats.connectivity.DownstreamType;
+import android.stats.connectivity.ErrorCode;
+import android.stats.connectivity.UpstreamType;
+import android.stats.connectivity.UserType;
+import android.util.Pair;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public final class TetheringMetricsTest {
+    private static final String TEST_CALLER_PKG = "com.test.caller.pkg";
+    private static final String SETTINGS_PKG = "com.android.settings";
+    private static final String SYSTEMUI_PKG = "com.android.systemui";
+    private static final String GMS_PKG = "com.google.android.gms";
+    private TetheringMetrics mTetheringMetrics;
+
+    private final NetworkTetheringReported.Builder mStatsBuilder =
+            NetworkTetheringReported.newBuilder();
+
+    private class MockTetheringMetrics extends TetheringMetrics {
+        @Override
+        public void write(final NetworkTetheringReported reported) { }
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        mTetheringMetrics = spy(new MockTetheringMetrics());
+    }
+
+    private void verifyReport(DownstreamType downstream, ErrorCode error, UserType user)
+            throws Exception {
+        final NetworkTetheringReported expectedReport =
+                mStatsBuilder.setDownstreamType(downstream)
+                .setUserType(user)
+                .setUpstreamType(UpstreamType.UT_UNKNOWN)
+                .setErrorCode(error)
+                .build();
+        verify(mTetheringMetrics).write(expectedReport);
+    }
+
+    private void updateErrorAndSendReport(int downstream, int error) {
+        mTetheringMetrics.updateErrorCode(downstream, error);
+        mTetheringMetrics.sendReport(downstream);
+    }
+
+    private void runDownstreamTypesTest(final Pair<Integer, DownstreamType>... testPairs)
+            throws Exception {
+        for (Pair<Integer, DownstreamType> testPair : testPairs) {
+            final int type = testPair.first;
+            final DownstreamType expectedResult = testPair.second;
+
+            mTetheringMetrics.createBuilder(type, TEST_CALLER_PKG);
+            updateErrorAndSendReport(type, TETHER_ERROR_NO_ERROR);
+            verifyReport(expectedResult, ErrorCode.EC_NO_ERROR, UserType.USER_UNKNOWN);
+            reset(mTetheringMetrics);
+        }
+    }
+
+    @Test
+    public void testDownstreamTypes() throws Exception {
+        runDownstreamTypesTest(new Pair<>(TETHERING_WIFI, DownstreamType.DS_TETHERING_WIFI),
+                new Pair<>(TETHERING_WIFI_P2P, DownstreamType.DS_TETHERING_WIFI_P2P),
+                new Pair<>(TETHERING_BLUETOOTH, DownstreamType.DS_TETHERING_BLUETOOTH),
+                new Pair<>(TETHERING_USB, DownstreamType.DS_TETHERING_USB),
+                new Pair<>(TETHERING_NCM, DownstreamType.DS_TETHERING_NCM),
+                new Pair<>(TETHERING_ETHERNET, DownstreamType.DS_TETHERING_ETHERNET));
+    }
+
+    private void runErrorCodesTest(final Pair<Integer, ErrorCode>... testPairs)
+            throws Exception {
+        for (Pair<Integer, ErrorCode> testPair : testPairs) {
+            final int errorCode = testPair.first;
+            final ErrorCode expectedResult = testPair.second;
+
+            mTetheringMetrics.createBuilder(TETHERING_WIFI, TEST_CALLER_PKG);
+            updateErrorAndSendReport(TETHERING_WIFI, errorCode);
+            verifyReport(DownstreamType.DS_TETHERING_WIFI, expectedResult, UserType.USER_UNKNOWN);
+            reset(mTetheringMetrics);
+        }
+    }
+
+    @Test
+    public void testErrorCodes() throws Exception {
+        runErrorCodesTest(new Pair<>(TETHER_ERROR_NO_ERROR, ErrorCode.EC_NO_ERROR),
+                new Pair<>(TETHER_ERROR_UNKNOWN_IFACE, ErrorCode.EC_UNKNOWN_IFACE),
+                new Pair<>(TETHER_ERROR_SERVICE_UNAVAIL, ErrorCode.EC_SERVICE_UNAVAIL),
+                new Pair<>(TETHER_ERROR_UNSUPPORTED, ErrorCode.EC_UNSUPPORTED),
+                new Pair<>(TETHER_ERROR_UNAVAIL_IFACE, ErrorCode.EC_UNAVAIL_IFACE),
+                new Pair<>(TETHER_ERROR_INTERNAL_ERROR, ErrorCode.EC_INTERNAL_ERROR),
+                new Pair<>(TETHER_ERROR_TETHER_IFACE_ERROR, ErrorCode.EC_TETHER_IFACE_ERROR),
+                new Pair<>(TETHER_ERROR_UNTETHER_IFACE_ERROR, ErrorCode.EC_UNTETHER_IFACE_ERROR),
+                new Pair<>(TETHER_ERROR_ENABLE_FORWARDING_ERROR,
+                ErrorCode.EC_ENABLE_FORWARDING_ERROR),
+                new Pair<>(TETHER_ERROR_DISABLE_FORWARDING_ERROR,
+                ErrorCode.EC_DISABLE_FORWARDING_ERROR),
+                new Pair<>(TETHER_ERROR_IFACE_CFG_ERROR, ErrorCode.EC_IFACE_CFG_ERROR),
+                new Pair<>(TETHER_ERROR_PROVISIONING_FAILED, ErrorCode.EC_PROVISIONING_FAILED),
+                new Pair<>(TETHER_ERROR_DHCPSERVER_ERROR, ErrorCode.EC_DHCPSERVER_ERROR),
+                new Pair<>(TETHER_ERROR_ENTITLEMENT_UNKNOWN, ErrorCode.EC_ENTITLEMENT_UNKNOWN),
+                new Pair<>(TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION,
+                ErrorCode.EC_NO_CHANGE_TETHERING_PERMISSION),
+                new Pair<>(TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION,
+                ErrorCode.EC_NO_ACCESS_TETHERING_PERMISSION),
+                new Pair<>(TETHER_ERROR_UNKNOWN_TYPE, ErrorCode.EC_UNKNOWN_TYPE));
+    }
+
+    private void runUserTypesTest(final Pair<String, UserType>... testPairs)
+            throws Exception {
+        for (Pair<String, UserType> testPair : testPairs) {
+            final String callerPkg = testPair.first;
+            final UserType expectedResult = testPair.second;
+
+            mTetheringMetrics.createBuilder(TETHERING_WIFI, callerPkg);
+            updateErrorAndSendReport(TETHERING_WIFI, TETHER_ERROR_NO_ERROR);
+            verifyReport(DownstreamType.DS_TETHERING_WIFI, ErrorCode.EC_NO_ERROR, expectedResult);
+            reset(mTetheringMetrics);
+        }
+    }
+
+    @Test
+    public void testUserTypes() throws Exception {
+        runUserTypesTest(new Pair<>(TEST_CALLER_PKG, UserType.USER_UNKNOWN),
+                new Pair<>(SETTINGS_PKG, UserType.USER_SETTINGS),
+                new Pair<>(SYSTEMUI_PKG, UserType.USER_SYSTEMUI),
+                new Pair<>(GMS_PKG, UserType.USER_GMS));
+    }
+
+    @Test
+    public void testMultiBuildersCreatedBeforeSendReport() throws Exception {
+        mTetheringMetrics.createBuilder(TETHERING_WIFI, SETTINGS_PKG);
+        mTetheringMetrics.createBuilder(TETHERING_USB, SYSTEMUI_PKG);
+        mTetheringMetrics.createBuilder(TETHERING_BLUETOOTH, GMS_PKG);
+
+        updateErrorAndSendReport(TETHERING_WIFI, TETHER_ERROR_DHCPSERVER_ERROR);
+        verifyReport(DownstreamType.DS_TETHERING_WIFI, ErrorCode.EC_DHCPSERVER_ERROR,
+                UserType.USER_SETTINGS);
+
+        updateErrorAndSendReport(TETHERING_USB, TETHER_ERROR_ENABLE_FORWARDING_ERROR);
+        verifyReport(DownstreamType.DS_TETHERING_USB, ErrorCode.EC_ENABLE_FORWARDING_ERROR,
+                UserType.USER_SYSTEMUI);
+
+        updateErrorAndSendReport(TETHERING_BLUETOOTH, TETHER_ERROR_TETHER_IFACE_ERROR);
+        verifyReport(DownstreamType.DS_TETHERING_BLUETOOTH, ErrorCode.EC_TETHER_IFACE_ERROR,
+                UserType.USER_GMS);
+    }
+}
diff --git a/bpf_progs/Android.bp b/bpf_progs/Android.bp
index 9e516bf..78fca29 100644
--- a/bpf_progs/Android.bp
+++ b/bpf_progs/Android.bp
@@ -63,6 +63,7 @@
 bpf {
     name: "block.o",
     srcs: ["block.c"],
+    btf: true,
     cflags: [
         "-Wall",
         "-Werror",
@@ -73,6 +74,7 @@
 bpf {
     name: "dscp_policy.o",
     srcs: ["dscp_policy.c"],
+    btf: true,
     cflags: [
         "-Wall",
         "-Werror",
@@ -101,6 +103,7 @@
 bpf {
     name: "clatd.o",
     srcs: ["clatd.c"],
+    btf: true,
     cflags: [
         "-Wall",
         "-Werror",
@@ -112,6 +115,7 @@
     // WARNING: Android T's non-updatable netd depends on 'netd' string for xt_bpf programs it loads
     name: "netd.o",
     srcs: ["netd.c"],
+    btf: true,
     cflags: [
         "-Wall",
         "-Werror",
diff --git a/bpf_progs/bpf_shared.h b/bpf_progs/bpf_shared.h
index fd449a3..85b9f86 100644
--- a/bpf_progs/bpf_shared.h
+++ b/bpf_progs/bpf_shared.h
@@ -148,6 +148,7 @@
 
 #endif // __cplusplus
 
+// LINT.IfChange(match_type)
 enum UidOwnerMatchType {
     NO_MATCH = 0,
     HAPPY_BOX_MATCH = (1 << 0),
@@ -163,6 +164,7 @@
     OEM_DENY_2_MATCH = (1 << 10),
     OEM_DENY_3_MATCH = (1 << 11),
 };
+// LINT.ThenChange(packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java)
 
 enum BpfPermissionMatch {
     BPF_PERMISSION_INTERNET = 1 << 2,
diff --git a/bpf_progs/dscp_policy.c b/bpf_progs/dscp_policy.c
index 538a9e4..92ea0e2 100644
--- a/bpf_progs/dscp_policy.c
+++ b/bpf_progs/dscp_policy.c
@@ -14,17 +14,17 @@
  * limitations under the License.
  */
 
-#include <linux/types.h>
 #include <linux/bpf.h>
+#include <linux/if_ether.h>
 #include <linux/if_packet.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
-#include <linux/if_ether.h>
 #include <linux/pkt_cls.h>
 #include <linux/tcp.h>
-#include <stdint.h>
+#include <linux/types.h>
 #include <netinet/in.h>
 #include <netinet/udp.h>
+#include <stdint.h>
 #include <string.h>
 
 // The resulting .o needs to load on the Android T beta 3 bpfloader
@@ -33,21 +33,25 @@
 #include "bpf_helpers.h"
 #include "dscp_policy.h"
 
+#define ECN_MASK 3
+#define IP4_OFFSET(field, header) (header + offsetof(struct iphdr, field))
+#define UPDATE_TOS(dscp, tos) (dscp << 2) | (tos & ECN_MASK)
+#define UPDATE_PRIORITY(dscp) ((dscp >> 2) + 0x60)
+#define UPDATE_FLOW_LABEL(dscp, flow_lbl) ((dscp & 0xf) << 6) + (flow_lbl >> 6)
+
 DEFINE_BPF_MAP_GRW(switch_comp_map, ARRAY, int, uint64_t, 1, AID_SYSTEM)
 
 DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
+                   AID_SYSTEM)
 DEFINE_BPF_MAP_GRW(ipv4_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
+                   AID_SYSTEM)
 DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_A, HASH, uint64_t, RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
+                   AID_SYSTEM)
 DEFINE_BPF_MAP_GRW(ipv6_socket_to_policies_map_B, HASH, uint64_t, RuleEntry, MAX_POLICIES,
-        AID_SYSTEM)
+                   AID_SYSTEM)
 
-DEFINE_BPF_MAP_GRW(ipv4_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES,
-        AID_SYSTEM)
-DEFINE_BPF_MAP_GRW(ipv6_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES,
-        AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv4_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES, AID_SYSTEM)
+DEFINE_BPF_MAP_GRW(ipv6_dscp_policies_map, ARRAY, uint32_t, DscpPolicy, MAX_POLICIES, AID_SYSTEM)
 
 static inline __always_inline void match_policy(struct __sk_buff* skb, bool ipv4, bool is_eth) {
     void* data = (void*)(long)skb->data;
@@ -69,21 +73,21 @@
 
     // used for map lookup
     uint64_t cookie = bpf_get_socket_cookie(skb);
-    if (!cookie)
-        return;
+    if (!cookie) return;
 
     uint16_t sport = 0;
     uint16_t dport = 0;
-    uint8_t protocol = 0; // TODO: Use are reserved value? Or int (-1) and cast to uint below?
+    uint8_t protocol = 0;  // TODO: Use are reserved value? Or int (-1) and cast to uint below?
     struct in6_addr srcIp = {};
     struct in6_addr dstIp = {};
-    uint8_t tos = 0; // Only used for IPv4
-    uint8_t priority = 0; // Only used for IPv6
-    uint8_t flow_lbl = 0; // Only used for IPv6
+    uint8_t tos = 0;       // Only used for IPv4
+    uint8_t priority = 0;  // Only used for IPv6
+    uint8_t flow_lbl = 0;  // Only used for IPv6
     if (ipv4) {
         const struct iphdr* const iph = is_eth ? (void*)(eth + 1) : data;
+        hdr_size = l2_header_size + sizeof(struct iphdr);
         // Must have ipv4 header
-        if (data + l2_header_size + sizeof(*iph) > data_end) return;
+        if (data + hdr_size > data_end) return;
 
         // IP version must be 4
         if (iph->version != 4) return;
@@ -100,11 +104,11 @@
         dstIp.s6_addr32[3] = iph->daddr;
         protocol = iph->protocol;
         tos = iph->tos;
-        hdr_size = sizeof(struct iphdr);
     } else {
         struct ipv6hdr* ip6h = is_eth ? (void*)(eth + 1) : data;
+        hdr_size = l2_header_size + sizeof(struct ipv6hdr);
         // Must have ipv6 header
-        if (data + l2_header_size + sizeof(*ip6h) > data_end) return;
+        if (data + hdr_size > data_end) return;
 
         if (ip6h->version != 6) return;
 
@@ -113,29 +117,24 @@
         protocol = ip6h->nexthdr;
         priority = ip6h->priority;
         flow_lbl = ip6h->flow_lbl[0];
-        hdr_size = sizeof(struct ipv6hdr);
     }
 
     switch (protocol) {
         case IPPROTO_UDP:
-        case IPPROTO_UDPLITE:
-        {
-            struct udphdr *udp;
+        case IPPROTO_UDPLITE: {
+            struct udphdr* udp;
             udp = data + hdr_size;
             if ((void*)(udp + 1) > data_end) return;
             sport = udp->source;
             dport = udp->dest;
-        }
-        break;
-        case IPPROTO_TCP:
-        {
-            struct tcphdr *tcp;
+        } break;
+        case IPPROTO_TCP: {
+            struct tcphdr* tcp;
             tcp = data + hdr_size;
             if ((void*)(tcp + 1) > data_end) return;
             sport = tcp->source;
             dport = tcp->dest;
-        }
-        break;
+        } break;
         default:
             return;
     }
@@ -156,22 +155,19 @@
     }
 
     if (existingRule && v6_equal(srcIp, existingRule->srcIp) &&
-                v6_equal(dstIp, existingRule->dstIp) &&
-                skb->ifindex == existingRule->ifindex &&
-                ntohs(sport) == htons(existingRule->srcPort) &&
-                ntohs(dport) == htons(existingRule->dstPort) &&
-                protocol == existingRule->proto) {
+        v6_equal(dstIp, existingRule->dstIp) && skb->ifindex == existingRule->ifindex &&
+        ntohs(sport) == htons(existingRule->srcPort) &&
+        ntohs(dport) == htons(existingRule->dstPort) && protocol == existingRule->proto) {
         if (ipv4) {
-            int ecn = tos & 3;
-            uint8_t newDscpVal = (existingRule->dscpVal << 2) + ecn;
-            int oldDscpVal = tos >> 2;
-            bpf_l3_csum_replace(skb, 1, oldDscpVal, newDscpVal, sizeof(uint8_t));
-            bpf_skb_store_bytes(skb, 1, &newDscpVal, sizeof(uint8_t), 0);
+            uint8_t newTos = UPDATE_TOS(existingRule->dscpVal, tos);
+            bpf_l3_csum_replace(skb, IP4_OFFSET(check, l2_header_size), htons(tos), htons(newTos),
+                                sizeof(uint16_t));
+            bpf_skb_store_bytes(skb, IP4_OFFSET(tos, l2_header_size), &newTos, sizeof(newTos), 0);
         } else {
-            uint8_t new_priority = (existingRule->dscpVal >> 2) + 0x60;
-            uint8_t new_flow_label = ((existingRule->dscpVal & 0xf) << 6) + (priority >> 6);
-            bpf_skb_store_bytes(skb, 0, &new_priority, sizeof(uint8_t), 0);
-            bpf_skb_store_bytes(skb, 1, &new_flow_label, sizeof(uint8_t), 0);
+            uint8_t new_priority = UPDATE_PRIORITY(existingRule->dscpVal);
+            uint8_t new_flow_label = UPDATE_FLOW_LABEL(existingRule->dscpVal, flow_lbl);
+            bpf_skb_store_bytes(skb, 0 + l2_header_size, &new_priority, sizeof(uint8_t), 0);
+            bpf_skb_store_bytes(skb, 1 + l2_header_size, &new_flow_label, sizeof(uint8_t), 0);
         }
         return;
     }
@@ -196,32 +192,31 @@
 
         // If the policy lookup failed, presentFields is 0, or iface index does not match
         // index on skb buff, then we can continue to next policy.
-        if (!policy || policy->presentFields == 0 || policy->ifindex != skb->ifindex)
-            continue;
+        if (!policy || policy->presentFields == 0 || policy->ifindex != skb->ifindex) continue;
 
         if ((policy->presentFields & SRC_IP_MASK_FLAG) == SRC_IP_MASK_FLAG &&
-                v6_equal(srcIp, policy->srcIp)) {
+            v6_equal(srcIp, policy->srcIp)) {
             score++;
             tempMask |= SRC_IP_MASK_FLAG;
         }
         if ((policy->presentFields & DST_IP_MASK_FLAG) == DST_IP_MASK_FLAG &&
-                v6_equal(dstIp, policy->dstIp)) {
+            v6_equal(dstIp, policy->dstIp)) {
             score++;
             tempMask |= DST_IP_MASK_FLAG;
         }
         if ((policy->presentFields & SRC_PORT_MASK_FLAG) == SRC_PORT_MASK_FLAG &&
-                ntohs(sport) == htons(policy->srcPort)) {
+            ntohs(sport) == htons(policy->srcPort)) {
             score++;
             tempMask |= SRC_PORT_MASK_FLAG;
         }
         if ((policy->presentFields & DST_PORT_MASK_FLAG) == DST_PORT_MASK_FLAG &&
-                ntohs(dport) >= htons(policy->dstPortStart) &&
-                ntohs(dport) <= htons(policy->dstPortEnd)) {
+            ntohs(dport) >= htons(policy->dstPortStart) &&
+            ntohs(dport) <= htons(policy->dstPortEnd)) {
             score++;
             tempMask |= DST_PORT_MASK_FLAG;
         }
         if ((policy->presentFields & PROTO_MASK_FLAG) == PROTO_MASK_FLAG &&
-                protocol == policy->proto) {
+            protocol == policy->proto) {
             score++;
             tempMask |= PROTO_MASK_FLAG;
         }
@@ -232,7 +227,8 @@
         }
     }
 
-    uint8_t new_tos= 0; // Can 0 be used as default forwarding value?
+    uint8_t new_tos = 0;  // Can 0 be used as default forwarding value?
+    uint8_t new_dscp = 0;
     uint8_t new_priority = 0;
     uint8_t new_flow_lbl = 0;
     if (bestScore > 0) {
@@ -244,20 +240,16 @@
         }
 
         if (policy) {
-            // TODO: if DSCP value is already set ignore?
+            new_dscp = policy->dscpVal;
             if (ipv4) {
-                int ecn = tos & 3;
-                new_tos = (policy->dscpVal << 2) + ecn;
+                new_tos = UPDATE_TOS(new_dscp, tos);
             } else {
-                new_priority = (policy->dscpVal >> 2) + 0x60;
-                new_flow_lbl = ((policy->dscpVal & 0xf) << 6) + (flow_lbl >> 6);
-
-                // Set IPv6 curDscp value to stored value and recalulate priority
-                // and flow label during next use.
-                new_tos = policy->dscpVal;
+                new_priority = UPDATE_PRIORITY(new_dscp);
+                new_flow_lbl = UPDATE_FLOW_LABEL(new_dscp, flow_lbl);
             }
         }
-    } else return;
+    } else
+        return;
 
     RuleEntry value = {
         .srcIp = srcIp,
@@ -266,10 +258,10 @@
         .srcPort = sport,
         .dstPort = dport,
         .proto = protocol,
-        .dscpVal = new_tos,
+        .dscpVal = new_dscp,
     };
 
-    //Update map with new policy.
+    // Update map with new policy.
     if (ipv4) {
         if (*selectedMap == MAP_A) {
             bpf_ipv4_socket_to_policies_map_A_update_elem(&cookie, &value, BPF_ANY);
@@ -286,20 +278,18 @@
 
     // Need to store bytes after updating map or program will not load.
     if (ipv4 && new_tos != (tos & 252)) {
-        int oldDscpVal = tos >> 2;
-        bpf_l3_csum_replace(skb, 1, oldDscpVal, new_tos, sizeof(uint8_t));
-        bpf_skb_store_bytes(skb, 1, &new_tos, sizeof(uint8_t), 0);
+        bpf_l3_csum_replace(skb, IP4_OFFSET(check, l2_header_size), htons(tos), htons(new_tos), 2);
+        bpf_skb_store_bytes(skb, IP4_OFFSET(tos, l2_header_size), &new_tos, sizeof(new_tos), 0);
     } else if (!ipv4 && (new_priority != priority || new_flow_lbl != flow_lbl)) {
-        bpf_skb_store_bytes(skb, 0, &new_priority, sizeof(uint8_t), 0);
-        bpf_skb_store_bytes(skb, 1, &new_flow_lbl, sizeof(uint8_t), 0);
+        bpf_skb_store_bytes(skb, l2_header_size, &new_priority, sizeof(new_priority), 0);
+        bpf_skb_store_bytes(skb, l2_header_size + 1, &new_flow_lbl, sizeof(new_flow_lbl), 0);
     }
     return;
 }
 
 DEFINE_BPF_PROG_KVER("schedcls/set_dscp_ether", AID_ROOT, AID_SYSTEM,
-                     schedcls_set_dscp_ether, KVER(5, 4, 0))
+                     schedcls_set_dscp_ether, KVER(5, 15, 0))
 (struct __sk_buff* skb) {
-
     if (skb->pkt_type != PACKET_HOST) return TC_ACT_PIPE;
 
     if (skb->protocol == htons(ETH_P_IP)) {
@@ -313,7 +303,7 @@
 }
 
 DEFINE_BPF_PROG_KVER("schedcls/set_dscp_raw_ip", AID_ROOT, AID_SYSTEM,
-                     schedcls_set_dscp_raw_ip, KVER(5, 4, 0))
+                     schedcls_set_dscp_raw_ip, KVER(5, 15, 0))
 (struct __sk_buff* skb) {
     if (skb->protocol == htons(ETH_P_IP)) {
         match_policy(skb, true, false);
diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 24b3fed..44f76de 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -217,6 +217,11 @@
     return *config;
 }
 
+// DROP_IF_SET is set of rules that BPF_DROP if rule is globally enabled, and per-uid bit is set
+#define DROP_IF_SET (STANDBY_MATCH | OEM_DENY_1_MATCH | OEM_DENY_2_MATCH | OEM_DENY_3_MATCH)
+// DROP_IF_UNSET is set of rules that should DROP if globally enabled, and per-uid bit is NOT set
+#define DROP_IF_UNSET (DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH | LOW_POWER_STANDBY_MATCH)
+
 static inline int bpf_owner_match(struct __sk_buff* skb, uint32_t uid, int direction) {
     if (skip_owner_match(skb)) return BPF_PASS;
 
@@ -228,32 +233,13 @@
     uint32_t uidRules = uidEntry ? uidEntry->rule : 0;
     uint32_t allowed_iif = uidEntry ? uidEntry->iif : 0;
 
-    if (enabledRules) {
-        if ((enabledRules & DOZABLE_MATCH) && !(uidRules & DOZABLE_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & STANDBY_MATCH) && (uidRules & STANDBY_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & POWERSAVE_MATCH) && !(uidRules & POWERSAVE_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & RESTRICTED_MATCH) && !(uidRules & RESTRICTED_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & LOW_POWER_STANDBY_MATCH) && !(uidRules & LOW_POWER_STANDBY_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & OEM_DENY_1_MATCH) && (uidRules & OEM_DENY_1_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & OEM_DENY_2_MATCH) && (uidRules & OEM_DENY_2_MATCH)) {
-            return BPF_DROP;
-        }
-        if ((enabledRules & OEM_DENY_3_MATCH) && (uidRules & OEM_DENY_3_MATCH)) {
-            return BPF_DROP;
-        }
-    }
+    // Warning: funky bit-wise arithmetic: in parallel, for all DROP_IF_SET/UNSET rules
+    // check whether the rules are globally enabled, and if so whether the rules are
+    // set/unset for the specific uid.  BPF_DROP if that is the case for ANY of the rules.
+    // We achieve this by masking out only the bits/rules we're interested in checking,
+    // and negating (via bit-wise xor) the bits/rules that should drop if unset.
+    if (enabledRules & (DROP_IF_SET | DROP_IF_UNSET) & (uidRules ^ DROP_IF_UNSET)) return BPF_DROP;
+
     if (direction == BPF_INGRESS && skb->ifindex != 1) {
         if (uidRules & IIF_MATCH) {
             if (allowed_iif && skb->ifindex != allowed_iif) {
@@ -425,8 +411,7 @@
     return BPF_NOMATCH;
 }
 
-DEFINE_BPF_PROG_EXT("cgroupsock/inet/create", AID_ROOT, AID_ROOT, inet_socket_create,
-                    KVER(4, 14, 0), KVER_INF, false, "fs_bpf_netd_readonly", "")
+DEFINE_NETD_BPF_PROG("cgroupsock/inet/create", AID_ROOT, AID_ROOT, inet_socket_create)
 (struct bpf_sock* sk) {
     uint64_t gid_uid = bpf_get_current_uid_gid();
     /*
diff --git a/common/Android.bp b/common/Android.bp
new file mode 100644
index 0000000..729ef32
--- /dev/null
+++ b/common/Android.bp
@@ -0,0 +1,45 @@
+//
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package {
+    // See: http://go/android-license-faq
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+java_library {
+    name: "connectivity-net-module-utils-bpf",
+    srcs: [
+        "src/com/android/net/module/util/bpf/*.java",
+    ],
+    sdk_version: "module_current",
+    min_sdk_version: "29",
+    visibility: [
+        // Do not add any lib. This library is only shared inside connectivity module
+        // and its tests.
+        "//packages/modules/Connectivity:__subpackages__",
+    ],
+    libs: [
+        "androidx.annotation_annotation",
+        "framework-connectivity.stubs.module_lib",
+    ],
+    static_libs: [
+        "net-utils-device-common-struct",
+    ],
+    apex_available: [
+        "com.android.tethering",
+    ],
+    lint: { strict_updatability_linting: true },
+}
diff --git a/common/src/com/android/net/module/util/bpf/ClatEgress4Key.java b/common/src/com/android/net/module/util/bpf/ClatEgress4Key.java
new file mode 100644
index 0000000..12200ec
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/ClatEgress4Key.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.Inet4Address;
+
+/** Key type for clat egress IPv4 maps. */
+public class ClatEgress4Key extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long iif; // The input interface index
+
+    @Field(order = 1, type = Type.Ipv4Address)
+    public final Inet4Address local4; // The source IPv4 address
+
+    public ClatEgress4Key(final long iif, final Inet4Address local4) {
+        this.iif = iif;
+        this.local4 = local4;
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/ClatEgress4Value.java b/common/src/com/android/net/module/util/bpf/ClatEgress4Value.java
new file mode 100644
index 0000000..c10cb4d
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/ClatEgress4Value.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.Inet6Address;
+
+/** Value type for clat egress IPv4 maps. */
+public class ClatEgress4Value extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long oif; // The output interface to redirect to
+
+    @Field(order = 1, type = Type.Ipv6Address)
+    public final Inet6Address local6; // The full 128-bits of the source IPv6 address
+
+    @Field(order = 2, type = Type.Ipv6Address)
+    public final Inet6Address pfx96; // The destination /96 nat64 prefix, bottom 32 bits must be 0
+
+    @Field(order = 3, type = Type.U8, padding = 3)
+    public final short oifIsEthernet; // Whether the output interface requires ethernet header
+
+    public ClatEgress4Value(final long oif, final Inet6Address local6, final Inet6Address pfx96,
+            final short oifIsEthernet) {
+        this.oif = oif;
+        this.local6 = local6;
+        this.pfx96 = pfx96;
+        this.oifIsEthernet = oifIsEthernet;
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/ClatIngress6Key.java b/common/src/com/android/net/module/util/bpf/ClatIngress6Key.java
new file mode 100644
index 0000000..1e2f4e0
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/ClatIngress6Key.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.Inet6Address;
+
+/** Key type for clat ingress IPv6 maps. */
+public class ClatIngress6Key extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long iif; // The input interface index
+
+    @Field(order = 1, type = Type.Ipv6Address)
+    public final Inet6Address pfx96; // The source /96 nat64 prefix, bottom 32 bits must be 0
+
+    @Field(order = 2, type = Type.Ipv6Address)
+    public final Inet6Address local6; // The full 128-bits of the destination IPv6 address
+
+    public ClatIngress6Key(final long iif, final Inet6Address pfx96, final Inet6Address local6) {
+        this.iif = iif;
+        this.pfx96 = pfx96;
+        this.local6 = local6;
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/ClatIngress6Value.java b/common/src/com/android/net/module/util/bpf/ClatIngress6Value.java
new file mode 100644
index 0000000..bfec44f
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/ClatIngress6Value.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.Inet4Address;
+
+/** Value type for clat ingress IPv6 maps. */
+public class ClatIngress6Value extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long oif; // The output interface to redirect to (0 means don't redirect)
+
+    @Field(order = 1, type = Type.Ipv4Address)
+    public final Inet4Address local4; // The destination IPv4 address
+
+    public ClatIngress6Value(final long oif, final Inet4Address local4) {
+        this.oif = oif;
+        this.local4 = local4;
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/Tether4Key.java b/common/src/com/android/net/module/util/bpf/Tether4Key.java
new file mode 100644
index 0000000..638576f
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/Tether4Key.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import android.net.MacAddress;
+
+import androidx.annotation.NonNull;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.Inet4Address;
+import java.net.UnknownHostException;
+import java.util.Objects;
+
+/** Key type for downstream & upstream IPv4 forwarding maps. */
+public class Tether4Key extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long iif;
+
+    @Field(order = 1, type = Type.EUI48)
+    public final MacAddress dstMac;
+
+    @Field(order = 2, type = Type.U8, padding = 1)
+    public final short l4proto;
+
+    @Field(order = 3, type = Type.ByteArray, arraysize = 4)
+    public final byte[] src4;
+
+    @Field(order = 4, type = Type.ByteArray, arraysize = 4)
+    public final byte[] dst4;
+
+    @Field(order = 5, type = Type.UBE16)
+    public final int srcPort;
+
+    @Field(order = 6, type = Type.UBE16)
+    public final int dstPort;
+
+    public Tether4Key(final long iif, @NonNull final MacAddress dstMac, final short l4proto,
+            final byte[] src4, final byte[] dst4, final int srcPort,
+            final int dstPort) {
+        Objects.requireNonNull(dstMac);
+
+        this.iif = iif;
+        this.dstMac = dstMac;
+        this.l4proto = l4proto;
+        this.src4 = src4;
+        this.dst4 = dst4;
+        this.srcPort = srcPort;
+        this.dstPort = dstPort;
+    }
+
+    @Override
+    public String toString() {
+        try {
+            return String.format(
+                    "iif: %d, dstMac: %s, l4proto: %d, src4: %s, dst4: %s, "
+                            + "srcPort: %d, dstPort: %d",
+                    iif, dstMac, l4proto,
+                    Inet4Address.getByAddress(src4), Inet4Address.getByAddress(dst4),
+                    Short.toUnsignedInt((short) srcPort), Short.toUnsignedInt((short) dstPort));
+        } catch (UnknownHostException | IllegalArgumentException e) {
+            return String.format("Invalid IP address", e);
+        }
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/Tether4Value.java b/common/src/com/android/net/module/util/bpf/Tether4Value.java
new file mode 100644
index 0000000..de98766
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/Tether4Value.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import android.net.MacAddress;
+
+import androidx.annotation.NonNull;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Objects;
+
+/** Value type for downstream & upstream IPv4 forwarding maps. */
+public class Tether4Value extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long oif;
+
+    // The ethhdr struct which is defined in uapi/linux/if_ether.h
+    @Field(order = 1, type = Type.EUI48)
+    public final MacAddress ethDstMac;
+    @Field(order = 2, type = Type.EUI48)
+    public final MacAddress ethSrcMac;
+    @Field(order = 3, type = Type.UBE16)
+    public final int ethProto;  // Packet type ID field.
+
+    @Field(order = 4, type = Type.U16)
+    public final int pmtu;
+
+    @Field(order = 5, type = Type.ByteArray, arraysize = 16)
+    public final byte[] src46;
+
+    @Field(order = 6, type = Type.ByteArray, arraysize = 16)
+    public final byte[] dst46;
+
+    @Field(order = 7, type = Type.UBE16)
+    public final int srcPort;
+
+    @Field(order = 8, type = Type.UBE16)
+    public final int dstPort;
+
+    // TODO: consider using U64.
+    @Field(order = 9, type = Type.U63)
+    public final long lastUsed;
+
+    public Tether4Value(final long oif, @NonNull final MacAddress ethDstMac,
+            @NonNull final MacAddress ethSrcMac, final int ethProto, final int pmtu,
+            final byte[] src46, final byte[] dst46, final int srcPort,
+            final int dstPort, final long lastUsed) {
+        Objects.requireNonNull(ethDstMac);
+        Objects.requireNonNull(ethSrcMac);
+
+        this.oif = oif;
+        this.ethDstMac = ethDstMac;
+        this.ethSrcMac = ethSrcMac;
+        this.ethProto = ethProto;
+        this.pmtu = pmtu;
+        this.src46 = src46;
+        this.dst46 = dst46;
+        this.srcPort = srcPort;
+        this.dstPort = dstPort;
+        this.lastUsed = lastUsed;
+    }
+
+    @Override
+    public String toString() {
+        try {
+            return String.format(
+                    "oif: %d, ethDstMac: %s, ethSrcMac: %s, ethProto: %d, pmtu: %d, "
+                            + "src46: %s, dst46: %s, srcPort: %d, dstPort: %d, "
+                            + "lastUsed: %d",
+                    oif, ethDstMac, ethSrcMac, ethProto, pmtu,
+                    InetAddress.getByAddress(src46), InetAddress.getByAddress(dst46),
+                    Short.toUnsignedInt((short) srcPort), Short.toUnsignedInt((short) dstPort),
+                    lastUsed);
+        } catch (UnknownHostException | IllegalArgumentException e) {
+            return String.format("Invalid IP address", e);
+        }
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/TetherStatsKey.java b/common/src/com/android/net/module/util/bpf/TetherStatsKey.java
new file mode 100644
index 0000000..c6d595b
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/TetherStatsKey.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/** The key of BpfMap which is used for tethering stats. */
+public class TetherStatsKey extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long ifindex;  // upstream interface index
+
+    public TetherStatsKey(final long ifindex) {
+        this.ifindex = ifindex;
+    }
+
+    // TODO: remove equals, hashCode and toString once aosp/1536721 is merged.
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+
+        if (!(obj instanceof TetherStatsKey)) return false;
+
+        final TetherStatsKey that = (TetherStatsKey) obj;
+
+        return ifindex == that.ifindex;
+    }
+
+    @Override
+    public int hashCode() {
+        return Long.hashCode(ifindex);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("ifindex: %d", ifindex);
+    }
+}
diff --git a/common/src/com/android/net/module/util/bpf/TetherStatsValue.java b/common/src/com/android/net/module/util/bpf/TetherStatsValue.java
new file mode 100644
index 0000000..028d217
--- /dev/null
+++ b/common/src/com/android/net/module/util/bpf/TetherStatsValue.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.net.module.util.bpf;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/** The key of BpfMap which is used for tethering stats. */
+public class TetherStatsValue extends Struct {
+    // Use the signed long variable to store the uint64 stats from stats BPF map.
+    // U63 is enough for each data element even at 5Gbps for ~468 years.
+    // 2^63 / (5 * 1000 * 1000 * 1000) * 8 / 86400 / 365 = 468.
+    @Field(order = 0, type = Type.U63)
+    public final long rxPackets;
+    @Field(order = 1, type = Type.U63)
+    public final long rxBytes;
+    @Field(order = 2, type = Type.U63)
+    public final long rxErrors;
+    @Field(order = 3, type = Type.U63)
+    public final long txPackets;
+    @Field(order = 4, type = Type.U63)
+    public final long txBytes;
+    @Field(order = 5, type = Type.U63)
+    public final long txErrors;
+
+    public TetherStatsValue(final long rxPackets, final long rxBytes, final long rxErrors,
+            final long txPackets, final long txBytes, final long txErrors) {
+        this.rxPackets = rxPackets;
+        this.rxBytes = rxBytes;
+        this.rxErrors = rxErrors;
+        this.txPackets = txPackets;
+        this.txBytes = txBytes;
+        this.txErrors = txErrors;
+    }
+
+    // TODO: remove equals, hashCode and toString once aosp/1536721 is merged.
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+
+        if (!(obj instanceof TetherStatsValue)) return false;
+
+        final TetherStatsValue that = (TetherStatsValue) obj;
+
+        return rxPackets == that.rxPackets
+                && rxBytes == that.rxBytes
+                && rxErrors == that.rxErrors
+                && txPackets == that.txPackets
+                && txBytes == that.txBytes
+                && txErrors == that.txErrors;
+    }
+
+    @Override
+    public int hashCode() {
+        return Long.hashCode(rxPackets) ^ Long.hashCode(rxBytes) ^ Long.hashCode(rxErrors)
+                ^ Long.hashCode(txPackets) ^ Long.hashCode(txBytes) ^ Long.hashCode(txErrors);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("rxPackets: %s, rxBytes: %s, rxErrors: %s, txPackets: %s, "
+                + "txBytes: %s, txErrors: %s", rxPackets, rxBytes, rxErrors, txPackets,
+                txBytes, txErrors);
+    }
+}
diff --git a/framework-t/src/android/net/EthernetManager.java b/framework-t/src/android/net/EthernetManager.java
index 886d194..b8070f0 100644
--- a/framework-t/src/android/net/EthernetManager.java
+++ b/framework-t/src/android/net/EthernetManager.java
@@ -22,13 +22,11 @@
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
-import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
 import android.annotation.SystemService;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
-import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.OutcomeReceiver;
 import android.os.RemoteException;
@@ -573,7 +571,6 @@
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
             android.Manifest.permission.NETWORK_STACK,
             android.Manifest.permission.MANAGE_ETHERNET_NETWORKS})
-    @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
     public void enableInterface(
             @NonNull String iface,
             @Nullable @CallbackExecutor Executor executor,
@@ -582,7 +579,7 @@
         final NetworkInterfaceOutcomeReceiver proxy = makeNetworkInterfaceOutcomeReceiver(
                 executor, callback);
         try {
-            mService.connectNetwork(iface, proxy);
+            mService.enableInterface(iface, proxy);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -610,7 +607,6 @@
             NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
             android.Manifest.permission.NETWORK_STACK,
             android.Manifest.permission.MANAGE_ETHERNET_NETWORKS})
-    @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
     public void disableInterface(
             @NonNull String iface,
             @Nullable @CallbackExecutor Executor executor,
@@ -619,7 +615,7 @@
         final NetworkInterfaceOutcomeReceiver proxy = makeNetworkInterfaceOutcomeReceiver(
                 executor, callback);
         try {
-            mService.disconnectNetwork(iface, proxy);
+            mService.disableInterface(iface, proxy);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/framework-t/src/android/net/IEthernetManager.aidl b/framework-t/src/android/net/IEthernetManager.aidl
index 42e4c1a..c1efc29 100644
--- a/framework-t/src/android/net/IEthernetManager.aidl
+++ b/framework-t/src/android/net/IEthernetManager.aidl
@@ -43,8 +43,8 @@
     void releaseTetheredInterface(in ITetheredInterfaceCallback callback);
     void updateConfiguration(String iface, in EthernetNetworkUpdateRequest request,
         in INetworkInterfaceOutcomeReceiver listener);
-    void connectNetwork(String iface, in INetworkInterfaceOutcomeReceiver listener);
-    void disconnectNetwork(String iface, in INetworkInterfaceOutcomeReceiver listener);
+    void enableInterface(String iface, in INetworkInterfaceOutcomeReceiver listener);
+    void disableInterface(String iface, in INetworkInterfaceOutcomeReceiver listener);
     void setEthernetEnabled(boolean enabled);
     List<String> getInterfaceList();
 }
diff --git a/framework-t/src/android/net/IpSecManager.java b/framework-t/src/android/net/IpSecManager.java
index 9cb0947..9cceac2 100644
--- a/framework-t/src/android/net/IpSecManager.java
+++ b/framework-t/src/android/net/IpSecManager.java
@@ -817,10 +817,10 @@
          * </ol>
          *
          * @param underlyingNetwork the new {@link Network} that will carry traffic for this tunnel.
-         *     This network MUST never be the network exposing this IpSecTunnelInterface, otherwise
-         *     this method will throw an {@link IllegalArgumentException}. If the
-         *     IpSecTunnelInterface is later added to this network, all outbound traffic will be
-         *     blackholed.
+         *     This network MUST be a functional {@link Network} with valid {@link LinkProperties},
+         *     and MUST never be the network exposing this IpSecTunnelInterface, otherwise this
+         *     method will throw an {@link IllegalArgumentException}. If the IpSecTunnelInterface is
+         *     later added to this network, all outbound traffic will be blackholed.
          */
         // TODO: b/169171001 Update the documentation when transform migration is supported.
         // The purpose of making updating network and applying transforms separate is to leave open
@@ -962,7 +962,6 @@
      * IP header and IPsec Header on all inbound traffic).
      * <p>Applications should probably not use this API directly.
      *
-     *
      * @param tunnel The {@link IpSecManager#IpSecTunnelInterface} that will use the supplied
      *        transform.
      * @param direction the direction, {@link DIRECTION_OUT} or {@link #DIRECTION_IN} in which
diff --git a/framework-t/src/android/net/nsd/NsdManager.java b/framework-t/src/android/net/nsd/NsdManager.java
index f19bf4a..fad63e5 100644
--- a/framework-t/src/android/net/nsd/NsdManager.java
+++ b/framework-t/src/android/net/nsd/NsdManager.java
@@ -175,6 +175,7 @@
      *
      * @see #ACTION_NSD_STATE_CHANGED
      */
+    // TODO: Deprecate this since NSD service is never disabled.
     public static final int NSD_STATE_DISABLED = 1;
 
     /**
@@ -230,17 +231,12 @@
     public static final int DAEMON_STARTUP                          = 19;
 
     /** @hide */
-    public static final int ENABLE                                  = 20;
-    /** @hide */
-    public static final int DISABLE                                 = 21;
+    public static final int MDNS_SERVICE_EVENT                      = 20;
 
     /** @hide */
-    public static final int MDNS_SERVICE_EVENT                      = 22;
-
+    public static final int REGISTER_CLIENT                         = 21;
     /** @hide */
-    public static final int REGISTER_CLIENT                         = 23;
-    /** @hide */
-    public static final int UNREGISTER_CLIENT                       = 24;
+    public static final int UNREGISTER_CLIENT                       = 22;
 
     /** Dns based service discovery protocol */
     public static final int PROTOCOL_DNS_SD = 0x0001;
@@ -266,8 +262,6 @@
         EVENT_NAMES.put(RESOLVE_SERVICE_SUCCEEDED, "RESOLVE_SERVICE_SUCCEEDED");
         EVENT_NAMES.put(DAEMON_CLEANUP, "DAEMON_CLEANUP");
         EVENT_NAMES.put(DAEMON_STARTUP, "DAEMON_STARTUP");
-        EVENT_NAMES.put(ENABLE, "ENABLE");
-        EVENT_NAMES.put(DISABLE, "DISABLE");
         EVENT_NAMES.put(MDNS_SERVICE_EVENT, "MDNS_SERVICE_EVENT");
     }
 
diff --git a/framework/Android.bp b/framework/Android.bp
index d7de439..6350e14 100644
--- a/framework/Android.bp
+++ b/framework/Android.bp
@@ -64,7 +64,6 @@
         ":framework-connectivity-sources",
         ":net-utils-framework-common-srcs",
         ":framework-connectivity-api-shared-srcs",
-        ":framework-connectivity-javastream-protos",
     ],
     aidl: {
         generate_get_transaction_name: true,
@@ -90,8 +89,10 @@
         "modules-utils-backgroundthread",
         "modules-utils-build",
         "modules-utils-preconditions",
+        "framework-connectivity-javastream-protos",
     ],
     libs: [
+        "androidx.annotation_annotation",
         "app-compat-annotations",
         "framework-connectivity-t.stubs.module_lib",
         "unsupportedappusage",
@@ -197,28 +198,16 @@
     visibility: ["//frameworks/base"],
 }
 
-gensrcs {
+java_library {
     name: "framework-connectivity-javastream-protos",
-    depfile: true,
-
-    tools: [
-        "aprotoc",
-        "protoc-gen-javastream",
-        "soong_zip",
+    proto: {
+        type: "stream",
+    },
+    srcs: [":framework-connectivity-protos"],
+    installable: false,
+    sdk_version: "module_current",
+    min_sdk_version: "30",
+    apex_available: [
+        "com.android.tethering",
     ],
-
-    cmd: "mkdir -p $(genDir)/$(in) " +
-        "&& $(location aprotoc) " +
-        "  --plugin=$(location protoc-gen-javastream) " +
-        "  --dependency_out=$(depfile) " +
-        "  --javastream_out=$(genDir)/$(in) " +
-        "  -Iexternal/protobuf/src " +
-        "  -I . " +
-        "  $(in) " +
-        "&& $(location soong_zip) -jar -o $(out) -C $(genDir)/$(in) -D $(genDir)/$(in)",
-
-    srcs: [
-        ":framework-connectivity-protos",
-    ],
-    output_extension: "srcjar",
 }
diff --git a/framework/api/module-lib-current.txt b/framework/api/module-lib-current.txt
index ddac19d..a2a1ac0 100644
--- a/framework/api/module-lib-current.txt
+++ b/framework/api/module-lib-current.txt
@@ -51,6 +51,9 @@
     field public static final int BLOCKED_REASON_RESTRICTED_MODE = 8; // 0x8
     field public static final int FIREWALL_CHAIN_DOZABLE = 1; // 0x1
     field public static final int FIREWALL_CHAIN_LOW_POWER_STANDBY = 5; // 0x5
+    field public static final int FIREWALL_CHAIN_OEM_DENY_1 = 7; // 0x7
+    field public static final int FIREWALL_CHAIN_OEM_DENY_2 = 8; // 0x8
+    field public static final int FIREWALL_CHAIN_OEM_DENY_3 = 9; // 0x9
     field public static final int FIREWALL_CHAIN_POWERSAVE = 3; // 0x3
     field public static final int FIREWALL_CHAIN_RESTRICTED = 4; // 0x4
     field public static final int FIREWALL_CHAIN_STANDBY = 2; // 0x2
@@ -197,6 +200,8 @@
     method public int describeContents();
     method @NonNull public android.os.ParcelFileDescriptor getFileDescriptor();
     method @NonNull public String getInterfaceName();
+    method @Nullable public android.net.MacAddress getMacAddress();
+    method public int getMtu();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.net.TestNetworkInterface> CREATOR;
   }
diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index db1d7e9..f1298ce 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -249,10 +249,10 @@
     method public void onValidationStatus(int, @Nullable android.net.Uri);
     method @NonNull public android.net.Network register();
     method public void sendAddDscpPolicy(@NonNull android.net.DscpPolicy);
-    method public final void sendLinkProperties(@NonNull android.net.LinkProperties);
-    method public final void sendNetworkCapabilities(@NonNull android.net.NetworkCapabilities);
-    method public final void sendNetworkScore(@NonNull android.net.NetworkScore);
-    method public final void sendNetworkScore(@IntRange(from=0, to=99) int);
+    method public void sendLinkProperties(@NonNull android.net.LinkProperties);
+    method public void sendNetworkCapabilities(@NonNull android.net.NetworkCapabilities);
+    method public void sendNetworkScore(@NonNull android.net.NetworkScore);
+    method public void sendNetworkScore(@IntRange(from=0, to=99) int);
     method public final void sendQosCallbackError(int, int);
     method public final void sendQosSessionAvailable(int, int, @NonNull android.net.QosSessionAttributes);
     method public final void sendQosSessionLost(int, int, int);
@@ -262,7 +262,7 @@
     method @Deprecated public void setLegacySubtype(int, @NonNull String);
     method public void setLingerDuration(@NonNull java.time.Duration);
     method public void setTeardownDelayMillis(@IntRange(from=0, to=0x1388) int);
-    method public final void setUnderlyingNetworks(@Nullable java.util.List<android.net.Network>);
+    method public void setUnderlyingNetworks(@Nullable java.util.List<android.net.Network>);
     method public void unregister();
     method public void unregisterAfterReplacement(@IntRange(from=0, to=0x1388) int);
     field public static final int DSCP_POLICY_STATUS_DELETED = 4; // 0x4
diff --git a/framework/jarjar-excludes.txt b/framework/jarjar-excludes.txt
new file mode 100644
index 0000000..1311765
--- /dev/null
+++ b/framework/jarjar-excludes.txt
@@ -0,0 +1,25 @@
+# INetworkStatsProvider / INetworkStatsProviderCallback are referenced from net-tests-utils, which
+# may be used by tests that do not apply connectivity jarjar rules.
+# TODO: move files to a known internal package (like android.net.connectivity.visiblefortesting)
+# so that they do not need jarjar
+android\.net\.netstats\.provider\.INetworkStatsProvider(\$.+)?
+android\.net\.netstats\.provider\.INetworkStatsProviderCallback(\$.+)?
+
+# INetworkAgent / INetworkAgentRegistry are used in NetworkAgentTest
+# TODO: move files to android.net.connectivity.visiblefortesting
+android\.net\.INetworkAgent(\$.+)?
+android\.net\.INetworkAgentRegistry(\$.+)?
+
+# IConnectivityDiagnosticsCallback used in ConnectivityDiagnosticsManagerTest
+# TODO: move files to android.net.connectivity.visiblefortesting
+android\.net\.IConnectivityDiagnosticsCallback(\$.+)?
+
+
+# KeepaliveUtils is used by ConnectivityManager CTS
+# TODO: move into service-connectivity so framework-connectivity stops using
+# ServiceConnectivityResources (callers need high permissions to find/query the resource apk anyway)
+# and have a ConnectivityManager test API instead
+android\.net\.util\.KeepaliveUtils(\$.+)?
+
+# TODO (b/217115866): add jarjar rules for Nearby
+android\.nearby\..+
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index f741c2b..c3f640d 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -983,20 +983,11 @@
     public static final int FIREWALL_CHAIN_LOW_POWER_STANDBY = 5;
 
     /**
-     * Firewall chain used for lockdown VPN.
-     * Denylist of apps that cannot receive incoming packets except on loopback because they are
-     * subject to an always-on VPN which is not currently connected.
-     *
-     * @see #BLOCKED_REASON_LOCKDOWN_VPN
-     * @hide
-     */
-    public static final int FIREWALL_CHAIN_LOCKDOWN_VPN = 6;
-
-    /**
      * Firewall chain used for OEM-specific application restrictions.
      * Denylist of apps that will not have network access due to OEM-specific restrictions.
      * @hide
      */
+    @SystemApi(client = MODULE_LIBRARIES)
     public static final int FIREWALL_CHAIN_OEM_DENY_1 = 7;
 
     /**
@@ -1004,6 +995,7 @@
      * Denylist of apps that will not have network access due to OEM-specific restrictions.
      * @hide
      */
+    @SystemApi(client = MODULE_LIBRARIES)
     public static final int FIREWALL_CHAIN_OEM_DENY_2 = 8;
 
     /**
@@ -1011,6 +1003,7 @@
      * Denylist of apps that will not have network access due to OEM-specific restrictions.
      * @hide
      */
+    @SystemApi(client = MODULE_LIBRARIES)
     public static final int FIREWALL_CHAIN_OEM_DENY_3 = 9;
 
     /** @hide */
@@ -1021,7 +1014,6 @@
         FIREWALL_CHAIN_POWERSAVE,
         FIREWALL_CHAIN_RESTRICTED,
         FIREWALL_CHAIN_LOW_POWER_STANDBY,
-        FIREWALL_CHAIN_LOCKDOWN_VPN,
         FIREWALL_CHAIN_OEM_DENY_1,
         FIREWALL_CHAIN_OEM_DENY_2,
         FIREWALL_CHAIN_OEM_DENY_3
@@ -2624,9 +2616,24 @@
      * {@hide}
      */
     public ConnectivityManager(Context context, IConnectivityManager service) {
+        this(context, service, true /* newStatic */);
+    }
+
+    private ConnectivityManager(Context context, IConnectivityManager service, boolean newStatic) {
         mContext = Objects.requireNonNull(context, "missing context");
         mService = Objects.requireNonNull(service, "missing IConnectivityManager");
-        sInstance = this;
+        // sInstance is accessed without a lock, so it may actually be reassigned several times with
+        // different ConnectivityManager, but that's still OK considering its usage.
+        if (sInstance == null && newStatic) {
+            final Context appContext = mContext.getApplicationContext();
+            // Don't create static ConnectivityManager instance again to prevent infinite loop.
+            // If the application context is null, we're either in the system process or
+            // it's the application context very early in app initialization. In both these
+            // cases, the passed-in Context will not be freed, so it's safe to pass it to the
+            // service. http://b/27532714 .
+            sInstance = new ConnectivityManager(appContext != null ? appContext : context, service,
+                    false /* newStatic */);
+        }
     }
 
     /** {@hide} */
@@ -4270,7 +4277,7 @@
      * network, unless it becomes the best again at some later time. All callbacks are invoked
      * in order on the same thread, which by default is a thread created by the framework running
      * in the app.
-     * {@see #requestNetwork(NetworkRequest, NetworkCallback, Handler)} to change where the
+     * {@link #requestNetwork(NetworkRequest, NetworkCallback, Handler)} to change where the
      * callbacks are invoked.
      *
      * <p>This{@link NetworkRequest} will live until released via
@@ -5896,6 +5903,7 @@
      *
      * @param chain target chain.
      * @param enable whether the chain should be enabled.
+     * @throws UnsupportedOperationException if called on pre-T devices.
      * @throws IllegalStateException if enabling or disabling the firewall chain failed.
      * @hide
      */
@@ -5914,6 +5922,29 @@
     }
 
     /**
+     * Get the specified firewall chain's status.
+     *
+     * @param chain target chain.
+     * @return {@code true} if chain is enabled, {@code false} if chain is disabled.
+     * @throws UnsupportedOperationException if called on pre-T devices.
+     * @throws ServiceSpecificException in case of failure, with an error code indicating the
+     *                                  cause of the failure.
+     * @hide
+     */
+    @RequiresPermission(anyOf = {
+            android.Manifest.permission.NETWORK_SETTINGS,
+            android.Manifest.permission.NETWORK_STACK,
+            NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK
+    })
+    public boolean getFirewallChainEnabled(@FirewallChain final int chain) {
+        try {
+            return mService.getFirewallChainEnabled(chain);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
      * Replaces the contents of the specified UID-based firewall chain.
      *
      * @param chain target chain to replace.
diff --git a/framework/src/android/net/IConnectivityManager.aidl b/framework/src/android/net/IConnectivityManager.aidl
index bc73769..29fea00 100644
--- a/framework/src/android/net/IConnectivityManager.aidl
+++ b/framework/src/android/net/IConnectivityManager.aidl
@@ -244,5 +244,7 @@
 
     void setFirewallChainEnabled(int chain, boolean enable);
 
+    boolean getFirewallChainEnabled(int chain);
+
     void replaceFirewallChain(int chain, in int[] uids);
 }
diff --git a/framework/src/android/net/ITestNetworkManager.aidl b/framework/src/android/net/ITestNetworkManager.aidl
index 27d13c1..d18b931 100644
--- a/framework/src/android/net/ITestNetworkManager.aidl
+++ b/framework/src/android/net/ITestNetworkManager.aidl
@@ -29,8 +29,10 @@
  */
 interface ITestNetworkManager
 {
-    TestNetworkInterface createInterface(boolean isTun, boolean bringUp, in LinkAddress[] addrs,
-            in @nullable String iface);
+    TestNetworkInterface createInterface(boolean isTun, boolean hasCarrier, boolean bringUp,
+            in LinkAddress[] addrs, in @nullable String iface);
+
+    void setCarrierEnabled(in TestNetworkInterface iface, boolean enabled);
 
     void setupTestNetwork(in String iface, in LinkProperties lp, in boolean isMetered,
             in int[] administratorUids, in IBinder binder);
diff --git a/framework/src/android/net/LinkProperties.java b/framework/src/android/net/LinkProperties.java
index a8f707e..76ca061 100644
--- a/framework/src/android/net/LinkProperties.java
+++ b/framework/src/android/net/LinkProperties.java
@@ -29,6 +29,8 @@
 import android.text.TextUtils;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.CollectionUtils;
 import com.android.net.module.util.LinkPropertiesUtils;
 
 import java.net.Inet4Address;
@@ -42,7 +44,6 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.StringJoiner;
-import java.util.stream.Collectors;
 
 /**
  * Describes the properties of a network link.
@@ -759,20 +760,25 @@
      * @return An unmodifiable {@link List} of {@link RouteInfo} for this link.
      */
     public @NonNull List<RouteInfo> getRoutes() {
-        if (CompatChanges.isChangeEnabled(EXCLUDED_ROUTES)) {
+        // Before T, there's no throw routes because VpnService is not updatable, so no need to
+        // filter them out.
+        if (CompatChanges.isChangeEnabled(EXCLUDED_ROUTES) || !SdkLevel.isAtLeastT()) {
             return Collections.unmodifiableList(mRoutes);
         } else {
-            return Collections.unmodifiableList(getUnicastRoutes());
+            // Apps that added a throw route themselves (not obtaining LinkProperties from the
+            // system) will not see it in getRoutes on T+ if they do not have the compat change
+            // enabled (target SDK < T); but this is expected to be rare and typically only affect
+            // tests creating LinkProperties themselves (like CTS v12, which is only running on S).
+            return Collections.unmodifiableList(getNonThrowRoutes());
         }
     }
 
     /**
-     * Returns all the {@link RouteInfo} of type {@link RouteInfo#RTN_UNICAST} set on this link.
+     * Returns all the {@link RouteInfo} that are not of type {@link RouteInfo#RTN_THROW} set on
+     * this link.
      */
-    private @NonNull List<RouteInfo> getUnicastRoutes() {
-        return mRoutes.stream()
-                .filter(route -> route.getType() == RouteInfo.RTN_UNICAST)
-                .collect(Collectors.toList());
+    private @NonNull List<RouteInfo> getNonThrowRoutes() {
+        return CollectionUtils.filter(mRoutes, route -> route.getType() != RouteInfo.RTN_THROW);
     }
 
     /**
diff --git a/framework/src/android/net/NetworkAgent.java b/framework/src/android/net/NetworkAgent.java
index 2c50c73..5659a35 100644
--- a/framework/src/android/net/NetworkAgent.java
+++ b/framework/src/android/net/NetworkAgent.java
@@ -913,7 +913,7 @@
      * Must be called by the agent when the network's {@link LinkProperties} change.
      * @param linkProperties the new LinkProperties.
      */
-    public final void sendLinkProperties(@NonNull LinkProperties linkProperties) {
+    public void sendLinkProperties(@NonNull LinkProperties linkProperties) {
         Objects.requireNonNull(linkProperties);
         final LinkProperties lp = new LinkProperties(linkProperties);
         queueOrSendMessage(reg -> reg.sendLinkProperties(lp));
@@ -938,7 +938,7 @@
      * @param underlyingNetworks the new list of underlying networks.
      * @see {@link VpnService.Builder#setUnderlyingNetworks(Network[])}
      */
-    public final void setUnderlyingNetworks(
+    public void setUnderlyingNetworks(
             @SuppressLint("NullableCollection") @Nullable List<Network> underlyingNetworks) {
         final ArrayList<Network> underlyingArray = (underlyingNetworks != null)
                 ? new ArrayList<>(underlyingNetworks) : null;
@@ -1088,7 +1088,7 @@
      * Must be called by the agent when the network's {@link NetworkCapabilities} change.
      * @param networkCapabilities the new NetworkCapabilities.
      */
-    public final void sendNetworkCapabilities(@NonNull NetworkCapabilities networkCapabilities) {
+    public void sendNetworkCapabilities(@NonNull NetworkCapabilities networkCapabilities) {
         Objects.requireNonNull(networkCapabilities);
         mBandwidthUpdatePending.set(false);
         mLastBwRefreshTime = System.currentTimeMillis();
@@ -1102,7 +1102,7 @@
      *
      * @param score the new score.
      */
-    public final void sendNetworkScore(@NonNull NetworkScore score) {
+    public void sendNetworkScore(@NonNull NetworkScore score) {
         Objects.requireNonNull(score);
         queueOrSendMessage(reg -> reg.sendScore(score));
     }
@@ -1113,7 +1113,7 @@
      * @param score the new score, between 0 and 99.
      * deprecated use sendNetworkScore(NetworkScore) TODO : remove in S.
      */
-    public final void sendNetworkScore(@IntRange(from = 0, to = 99) int score) {
+    public void sendNetworkScore(@IntRange(from = 0, to = 99) int score) {
         sendNetworkScore(new NetworkScore.Builder().setLegacyInt(score).build());
     }
 
diff --git a/framework/src/android/net/NetworkCapabilities.java b/framework/src/android/net/NetworkCapabilities.java
index 97b1f32..dbb05a9 100644
--- a/framework/src/android/net/NetworkCapabilities.java
+++ b/framework/src/android/net/NetworkCapabilities.java
@@ -3043,7 +3043,7 @@
          * <p>
          * This list cannot be null, but it can be empty to mean that no UID without the
          * {@link android.Manifest.permission.CONNECTIVITY_USE_RESTRICTED_NETWORKS} permission
-         * gets to access this network.
+         * can access this network.
          *
          * @param uids the list of UIDs that can always access this network
          * @return this builder
diff --git a/framework/src/android/net/NetworkProvider.java b/framework/src/android/net/NetworkProvider.java
index 0665af5..3615075 100644
--- a/framework/src/android/net/NetworkProvider.java
+++ b/framework/src/android/net/NetworkProvider.java
@@ -192,21 +192,36 @@
     private class NetworkOfferCallbackProxy extends INetworkOfferCallback.Stub {
         @NonNull public final NetworkOfferCallback callback;
         @NonNull private final Executor mExecutor;
+        /**
+         * Boolean flag that prevents onNetworkNeeded / onNetworkUnneeded callbacks from being
+         * propagated after unregisterNetworkOffer has been called. Since unregisterNetworkOffer
+         * runs on the CS handler thread, it will not go into effect immediately.
+         */
+        private volatile boolean mIsStale;
 
         NetworkOfferCallbackProxy(@NonNull final NetworkOfferCallback callback,
                 @NonNull final Executor executor) {
             this.callback = callback;
             this.mExecutor = executor;
+            this.mIsStale = false;
         }
 
         @Override
         public void onNetworkNeeded(final @NonNull NetworkRequest request) {
-            mExecutor.execute(() -> callback.onNetworkNeeded(request));
+            mExecutor.execute(() -> {
+                if (!mIsStale) callback.onNetworkNeeded(request);
+            });
         }
 
         @Override
         public void onNetworkUnneeded(final @NonNull NetworkRequest request) {
-            mExecutor.execute(() -> callback.onNetworkUnneeded(request));
+            mExecutor.execute(() -> {
+                if (!mIsStale) callback.onNetworkUnneeded(request);
+            });
+        }
+
+        public void markStale() {
+            mIsStale = true;
         }
     }
 
@@ -326,7 +341,10 @@
     public void unregisterNetworkOffer(final @NonNull NetworkOfferCallback callback) {
         final NetworkOfferCallbackProxy proxy = findProxyForCallback(callback);
         if (null == proxy) return;
-        mProxies.remove(proxy);
+        synchronized (mProxies) {
+            proxy.markStale();
+            mProxies.remove(proxy);
+        }
         mContext.getSystemService(ConnectivityManager.class).unofferNetwork(proxy);
     }
 }
diff --git a/framework/src/android/net/QosCallbackException.java b/framework/src/android/net/QosCallbackException.java
index ed6eb15..72430d2 100644
--- a/framework/src/android/net/QosCallbackException.java
+++ b/framework/src/android/net/QosCallbackException.java
@@ -46,8 +46,10 @@
             EX_TYPE_FILTER_NONE,
             EX_TYPE_FILTER_NETWORK_RELEASED,
             EX_TYPE_FILTER_SOCKET_NOT_BOUND,
+            EX_TYPE_FILTER_SOCKET_NOT_CONNECTED,
             EX_TYPE_FILTER_NOT_SUPPORTED,
             EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED,
+            EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED,
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface ExceptionType {}
@@ -55,6 +57,9 @@
     private static final String TAG = "QosCallbackException";
 
     // Types of exceptions supported //
+    // The constants are used for the sendQosCallbackError system API, so they must not be changed
+    // as there may be callers relying on their historical values to call that API.
+    // TODO: mark the constants as @SystemApi, since they are necessary to call a system API.
     /** {@hide} */
     public static final int EX_TYPE_FILTER_NONE = 0;
 
@@ -70,6 +75,12 @@
     /** {@hide} */
     public static final int EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED = 4;
 
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_SOCKET_NOT_CONNECTED = 5;
+
+    /** {@hide} */
+    public static final int EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED = 6;
+
     /**
      * Creates exception based off of a type and message.  Not all types of exceptions accept a
      * custom message.
@@ -83,12 +94,17 @@
                 return new QosCallbackException(new NetworkReleasedException());
             case EX_TYPE_FILTER_SOCKET_NOT_BOUND:
                 return new QosCallbackException(new SocketNotBoundException());
+            case EX_TYPE_FILTER_SOCKET_NOT_CONNECTED:
+                return new QosCallbackException(new SocketNotConnectedException());
             case EX_TYPE_FILTER_NOT_SUPPORTED:
                 return new QosCallbackException(new UnsupportedOperationException(
                         "This device does not support the specified filter"));
             case EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED:
                 return new QosCallbackException(
                         new SocketLocalAddressChangedException());
+            case EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED:
+                return new QosCallbackException(
+                        new SocketRemoteAddressChangedException());
             default:
                 Log.wtf(TAG, "create: No case setup for exception type: '" + type + "'");
                 return new QosCallbackException(
diff --git a/framework/src/android/net/QosFilter.java b/framework/src/android/net/QosFilter.java
index 5c1c3cc..b432644 100644
--- a/framework/src/android/net/QosFilter.java
+++ b/framework/src/android/net/QosFilter.java
@@ -90,5 +90,15 @@
      */
     public abstract boolean matchesRemoteAddress(@NonNull InetAddress address,
             int startPort, int endPort);
+
+    /**
+     * Determines whether or not the parameter will be matched with this filter.
+     *
+     * @param protocol the protocol such as TCP or UDP included in IP packet filter set of a QoS
+     *                 flow assigned on {@link Network}.
+     * @return whether the parameters match the socket type of the filter
+     * @hide
+     */
+    public abstract boolean matchesProtocol(int protocol);
 }
 
diff --git a/framework/src/android/net/QosFilterParcelable.java b/framework/src/android/net/QosFilterParcelable.java
index da3b2cf..6e71fa3 100644
--- a/framework/src/android/net/QosFilterParcelable.java
+++ b/framework/src/android/net/QosFilterParcelable.java
@@ -104,7 +104,7 @@
         if (mQosFilter instanceof QosSocketFilter) {
             dest.writeInt(QOS_SOCKET_FILTER);
             final QosSocketFilter qosSocketFilter = (QosSocketFilter) mQosFilter;
-            qosSocketFilter.getQosSocketInfo().writeToParcel(dest, 0);
+            qosSocketFilter.getQosSocketInfo().writeToParcelWithoutFd(dest, 0);
             return;
         }
         dest.writeInt(NO_FILTER_PRESENT);
diff --git a/framework/src/android/net/QosSocketFilter.java b/framework/src/android/net/QosSocketFilter.java
index 69da7f4..5ceeb67 100644
--- a/framework/src/android/net/QosSocketFilter.java
+++ b/framework/src/android/net/QosSocketFilter.java
@@ -18,6 +18,13 @@
 
 import static android.net.QosCallbackException.EX_TYPE_FILTER_NONE;
 import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_BOUND;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_CONNECTED;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED;
+import static android.system.OsConstants.IPPROTO_TCP;
+import static android.system.OsConstants.IPPROTO_UDP;
+import static android.system.OsConstants.SOCK_DGRAM;
+import static android.system.OsConstants.SOCK_STREAM;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -74,19 +81,34 @@
      * 2. In the scenario that the socket is now bound to a different local address, which can
      *    happen in the case of UDP, then
      *    {@link QosCallbackException.EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED} is returned.
+     * 3. In the scenario that the UDP socket changed remote address, then
+     *    {@link QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED} is returned.
+     *
      * @return validation error code
      */
     @Override
     public int validate() {
-        final InetSocketAddress sa = getAddressFromFileDescriptor();
-        if (sa == null) {
-            return QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_BOUND;
+        final InetSocketAddress sa = getLocalAddressFromFileDescriptor();
+
+        if (sa == null || (sa.getAddress().isAnyLocalAddress() && sa.getPort() == 0)) {
+            return EX_TYPE_FILTER_SOCKET_NOT_BOUND;
         }
 
         if (!sa.equals(mQosSocketInfo.getLocalSocketAddress())) {
             return EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED;
         }
 
+        if (mQosSocketInfo.getRemoteSocketAddress() != null) {
+            final InetSocketAddress da = getRemoteAddressFromFileDescriptor();
+            if (da == null) {
+                return EX_TYPE_FILTER_SOCKET_NOT_CONNECTED;
+            }
+
+            if (!da.equals(mQosSocketInfo.getRemoteSocketAddress())) {
+                return EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED;
+            }
+        }
+
         return EX_TYPE_FILTER_NONE;
     }
 
@@ -98,17 +120,14 @@
      * @return the local address
      */
     @Nullable
-    private InetSocketAddress getAddressFromFileDescriptor() {
+    private InetSocketAddress getLocalAddressFromFileDescriptor() {
         final ParcelFileDescriptor parcelFileDescriptor = mQosSocketInfo.getParcelFileDescriptor();
-        if (parcelFileDescriptor == null) return null;
-
         final FileDescriptor fd = parcelFileDescriptor.getFileDescriptor();
-        if (fd == null) return null;
 
         final SocketAddress address;
         try {
             address = Os.getsockname(fd);
-        } catch (final ErrnoException e) {
+        } catch (ErrnoException e) {
             Log.e(TAG, "getAddressFromFileDescriptor: getLocalAddress exception", e);
             return null;
         }
@@ -119,6 +138,31 @@
     }
 
     /**
+     * The remote address of the socket's connected.
+     *
+     * <p>Note: If the socket is no longer connected, null is returned.
+     *
+     * @return the remote address
+     */
+    @Nullable
+    private InetSocketAddress getRemoteAddressFromFileDescriptor() {
+        final ParcelFileDescriptor parcelFileDescriptor = mQosSocketInfo.getParcelFileDescriptor();
+        final FileDescriptor fd = parcelFileDescriptor.getFileDescriptor();
+
+        final SocketAddress address;
+        try {
+            address = Os.getpeername(fd);
+        } catch (ErrnoException e) {
+            Log.e(TAG, "getAddressFromFileDescriptor: getRemoteAddress exception", e);
+            return null;
+        }
+        if (address instanceof InetSocketAddress) {
+            return (InetSocketAddress) address;
+        }
+        return null;
+    }
+
+    /**
      * The network used with this filter.
      *
      * @return the registered {@link Network}
@@ -156,6 +200,18 @@
     }
 
     /**
+     * @inheritDoc
+     */
+    @Override
+    public boolean matchesProtocol(final int protocol) {
+        if ((mQosSocketInfo.getSocketType() == SOCK_STREAM && protocol == IPPROTO_TCP)
+                || (mQosSocketInfo.getSocketType() == SOCK_DGRAM && protocol == IPPROTO_UDP)) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
      * Called from {@link QosSocketFilter#matchesLocalAddress(InetAddress, int, int)}
      * and {@link QosSocketFilter#matchesRemoteAddress(InetAddress, int, int)} with the
      * filterSocketAddress coming from {@link QosSocketInfo#getLocalSocketAddress()}.
@@ -174,6 +230,7 @@
             final int startPort, final int endPort) {
         return startPort <= filterSocketAddress.getPort()
                 && endPort >= filterSocketAddress.getPort()
-                && filterSocketAddress.getAddress().equals(address);
+                && (address.isAnyLocalAddress()
+                        || filterSocketAddress.getAddress().equals(address));
     }
 }
diff --git a/framework/src/android/net/QosSocketInfo.java b/framework/src/android/net/QosSocketInfo.java
index 39c2f33..49ac22b 100644
--- a/framework/src/android/net/QosSocketInfo.java
+++ b/framework/src/android/net/QosSocketInfo.java
@@ -165,25 +165,28 @@
     /* Parcelable methods */
     private QosSocketInfo(final Parcel in) {
         mNetwork = Objects.requireNonNull(Network.CREATOR.createFromParcel(in));
-        mParcelFileDescriptor = ParcelFileDescriptor.CREATOR.createFromParcel(in);
+        final boolean withFd = in.readBoolean();
+        if (withFd) {
+            mParcelFileDescriptor = ParcelFileDescriptor.CREATOR.createFromParcel(in);
+        } else {
+            mParcelFileDescriptor = null;
+        }
 
-        final int localAddressLength = in.readInt();
-        mLocalSocketAddress = readSocketAddress(in, localAddressLength);
-
-        final int remoteAddressLength = in.readInt();
-        mRemoteSocketAddress = remoteAddressLength == 0 ? null
-                : readSocketAddress(in, remoteAddressLength);
+        mLocalSocketAddress = readSocketAddress(in);
+        mRemoteSocketAddress = readSocketAddress(in);
 
         mSocketType = in.readInt();
     }
 
-    private @NonNull InetSocketAddress readSocketAddress(final Parcel in, final int addressLength) {
-        final byte[] address = new byte[addressLength];
-        in.readByteArray(address);
+    private InetSocketAddress readSocketAddress(final Parcel in) {
+        final byte[] addrBytes = in.createByteArray();
+        if (addrBytes == null) {
+            return null;
+        }
         final int port = in.readInt();
 
         try {
-            return new InetSocketAddress(InetAddress.getByAddress(address), port);
+            return new InetSocketAddress(InetAddress.getByAddress(addrBytes), port);
         } catch (final UnknownHostException e) {
             /* This can never happen. UnknownHostException will never be thrown
                since the address provided is numeric and non-null. */
@@ -198,20 +201,35 @@
 
     @Override
     public void writeToParcel(@NonNull final Parcel dest, final int flags) {
-        mNetwork.writeToParcel(dest, 0);
-        mParcelFileDescriptor.writeToParcel(dest, 0);
+        writeToParcelInternal(dest, flags, /*includeFd=*/ true);
+    }
 
-        final byte[] localAddress = mLocalSocketAddress.getAddress().getAddress();
-        dest.writeInt(localAddress.length);
-        dest.writeByteArray(localAddress);
+    /**
+     * Used when sending QosSocketInfo to telephony, which does not need access to the socket FD.
+     * @hide
+     */
+    public void writeToParcelWithoutFd(@NonNull final Parcel dest, final int flags) {
+        writeToParcelInternal(dest, flags, /*includeFd=*/ false);
+    }
+
+    private void writeToParcelInternal(
+            @NonNull final Parcel dest, final int flags, boolean includeFd) {
+        mNetwork.writeToParcel(dest, 0);
+
+        if (includeFd) {
+            dest.writeBoolean(true);
+            mParcelFileDescriptor.writeToParcel(dest, 0);
+        } else {
+            dest.writeBoolean(false);
+        }
+
+        dest.writeByteArray(mLocalSocketAddress.getAddress().getAddress());
         dest.writeInt(mLocalSocketAddress.getPort());
 
         if (mRemoteSocketAddress == null) {
-            dest.writeInt(0);
+            dest.writeByteArray(null);
         } else {
-            final byte[] remoteAddress = mRemoteSocketAddress.getAddress().getAddress();
-            dest.writeInt(remoteAddress.length);
-            dest.writeByteArray(remoteAddress);
+            dest.writeByteArray(mRemoteSocketAddress.getAddress().getAddress());
             dest.writeInt(mRemoteSocketAddress.getPort());
         }
         dest.writeInt(mSocketType);
diff --git a/framework/src/android/net/SocketNotConnectedException.java b/framework/src/android/net/SocketNotConnectedException.java
new file mode 100644
index 0000000..fa2a615
--- /dev/null
+++ b/framework/src/android/net/SocketNotConnectedException.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+/**
+ * Thrown when a previously bound socket becomes unbound.
+ *
+ * @hide
+ */
+public class SocketNotConnectedException extends Exception {
+    /** @hide */
+    public SocketNotConnectedException() {
+        super("The socket is not connected");
+    }
+}
diff --git a/framework/src/android/net/SocketRemoteAddressChangedException.java b/framework/src/android/net/SocketRemoteAddressChangedException.java
new file mode 100644
index 0000000..ecaeebc
--- /dev/null
+++ b/framework/src/android/net/SocketRemoteAddressChangedException.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+/**
+ * Thrown when the local address of the socket has changed.
+ *
+ * @hide
+ */
+public class SocketRemoteAddressChangedException extends Exception {
+    /** @hide */
+    public SocketRemoteAddressChangedException() {
+        super("The remote address of the socket changed");
+    }
+}
diff --git a/framework/src/android/net/TestNetworkInterface.java b/framework/src/android/net/TestNetworkInterface.java
index 4449ff8..26200e1 100644
--- a/framework/src/android/net/TestNetworkInterface.java
+++ b/framework/src/android/net/TestNetworkInterface.java
@@ -16,22 +16,32 @@
 package android.net;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
+import android.util.Log;
+
+import java.net.NetworkInterface;
+import java.net.SocketException;
 
 /**
- * This class is used to return the interface name and fd of the test interface
+ * This class is used to return the interface name, fd, MAC, and MTU of the test interface
  *
  * @hide
  */
 @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
 public final class TestNetworkInterface implements Parcelable {
+    private static final String TAG = "TestNetworkInterface";
+
     @NonNull
     private final ParcelFileDescriptor mFileDescriptor;
     @NonNull
     private final String mInterfaceName;
+    @Nullable
+    private final MacAddress mMacAddress;
+    private final int mMtu;
 
     @Override
     public int describeContents() {
@@ -40,18 +50,41 @@
 
     @Override
     public void writeToParcel(@NonNull Parcel out, int flags) {
-        out.writeParcelable(mFileDescriptor, PARCELABLE_WRITE_RETURN_VALUE);
+        out.writeParcelable(mFileDescriptor, flags);
         out.writeString(mInterfaceName);
+        out.writeParcelable(mMacAddress, flags);
+        out.writeInt(mMtu);
     }
 
     public TestNetworkInterface(@NonNull ParcelFileDescriptor pfd, @NonNull String intf) {
         mFileDescriptor = pfd;
         mInterfaceName = intf;
+
+        MacAddress macAddress = null;
+        int mtu = 1500;
+        try {
+            // This constructor is called by TestNetworkManager which runs inside the system server,
+            // which has permission to read the MacAddress.
+            NetworkInterface nif = NetworkInterface.getByName(mInterfaceName);
+
+            // getHardwareAddress() returns null for tun interfaces.
+            byte[] hardwareAddress = nif.getHardwareAddress();
+            if (hardwareAddress != null) {
+                macAddress = MacAddress.fromBytes(nif.getHardwareAddress());
+            }
+            mtu = nif.getMTU();
+        } catch (SocketException e) {
+            Log.e(TAG, "Failed to fetch MacAddress or MTU size from NetworkInterface", e);
+        }
+        mMacAddress = macAddress;
+        mMtu = mtu;
     }
 
     private TestNetworkInterface(@NonNull Parcel in) {
         mFileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
         mInterfaceName = in.readString();
+        mMacAddress = in.readParcelable(MacAddress.class.getClassLoader());
+        mMtu = in.readInt();
     }
 
     @NonNull
@@ -64,6 +97,15 @@
         return mInterfaceName;
     }
 
+    @Nullable
+    public MacAddress getMacAddress() {
+        return mMacAddress;
+    }
+
+    public int getMtu() {
+        return mMtu;
+    }
+
     @NonNull
     public static final Parcelable.Creator<TestNetworkInterface> CREATOR =
             new Parcelable.Creator<TestNetworkInterface>() {
diff --git a/framework/src/android/net/TestNetworkManager.java b/framework/src/android/net/TestNetworkManager.java
index 4e78823..788834a 100644
--- a/framework/src/android/net/TestNetworkManager.java
+++ b/framework/src/android/net/TestNetworkManager.java
@@ -58,6 +58,7 @@
     private static final boolean TAP = false;
     private static final boolean TUN = true;
     private static final boolean BRING_UP = true;
+    private static final boolean CARRIER_UP = true;
     private static final LinkAddress[] NO_ADDRS = new LinkAddress[0];
 
     /** @hide */
@@ -166,7 +167,7 @@
     public TestNetworkInterface createTunInterface(@NonNull Collection<LinkAddress> linkAddrs) {
         try {
             final LinkAddress[] arr = new LinkAddress[linkAddrs.size()];
-            return mService.createInterface(TUN, BRING_UP, linkAddrs.toArray(arr),
+            return mService.createInterface(TUN, CARRIER_UP, BRING_UP, linkAddrs.toArray(arr),
                     null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
@@ -185,7 +186,25 @@
     @NonNull
     public TestNetworkInterface createTapInterface() {
         try {
-            return mService.createInterface(TAP, BRING_UP, NO_ADDRS, null /* iface */);
+            return mService.createInterface(TAP, CARRIER_UP, BRING_UP, NO_ADDRS, null /* iface */);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Create a tap interface for testing purposes
+     *
+     * @param linkAddrs an array of LinkAddresses to assign to the TAP interface
+     * @return A TestNetworkInterface representing the underlying TAP interface. Close the contained
+     *     ParcelFileDescriptor to tear down the TAP interface.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    @NonNull
+    public TestNetworkInterface createTapInterface(@NonNull LinkAddress[] linkAddrs) {
+        try {
+            return mService.createInterface(TAP, CARRIER_UP, BRING_UP, linkAddrs, null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -204,7 +223,7 @@
     @NonNull
     public TestNetworkInterface createTapInterface(boolean bringUp) {
         try {
-            return mService.createInterface(TAP, bringUp, NO_ADDRS, null /* iface */);
+            return mService.createInterface(TAP, CARRIER_UP, bringUp, NO_ADDRS, null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -226,7 +245,44 @@
     @NonNull
     public TestNetworkInterface createTapInterface(boolean bringUp, @NonNull String iface) {
         try {
-            return mService.createInterface(TAP, bringUp, NO_ADDRS, iface);
+            return mService.createInterface(TAP, CARRIER_UP, bringUp, NO_ADDRS, iface);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Create a tap interface with or without carrier for testing purposes.
+     *
+     * Note: setting carrierUp = false is not supported until kernel version 5.0.
+     *
+     * @param carrierUp whether the created interface has a carrier or not.
+     * @param bringUp whether to bring up the interface before returning it.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    @NonNull
+    public TestNetworkInterface createTapInterface(boolean carrierUp, boolean bringUp) {
+        try {
+            return mService.createInterface(TAP, carrierUp, bringUp, NO_ADDRS, null /* iface */);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Enable / disable carrier on TestNetworkInterface
+     *
+     * Note: TUNSETCARRIER is not supported until kernel version 5.0.
+     *
+     * @param iface the interface to configure.
+     * @param enabled true to turn carrier on, false to turn carrier off.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    public void setCarrierEnabled(@NonNull TestNetworkInterface iface, boolean enabled) {
+        try {
+            mService.setCarrierEnabled(iface, enabled);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/netd/Android.bp b/netd/Android.bp
index 5ac02d3..c731b8b 100644
--- a/netd/Android.bp
+++ b/netd/Android.bp
@@ -55,7 +55,8 @@
 cc_test {
     name: "netd_updatable_unit_test",
     defaults: ["netd_defaults"],
-    test_suites: ["general-tests"],
+    test_suites: ["general-tests", "mts-tethering"],
+    test_config_template: ":net_native_test_config_template",
     require_root: true,  // required by setrlimitForTest()
     header_libs: [
         "bpf_connectivity_headers",
@@ -72,6 +73,7 @@
         "liblog",
         "libnetdutils",
     ],
+    compile_multilib: "both",
     multilib: {
         lib32: {
             suffix: "32",
diff --git a/netd/BpfHandler.cpp b/netd/BpfHandler.cpp
index 6ae26c3..fad6bbb 100644
--- a/netd/BpfHandler.cpp
+++ b/netd/BpfHandler.cpp
@@ -73,16 +73,7 @@
     }
     RETURN_IF_NOT_OK(attachProgramToCgroup(BPF_EGRESS_PROG_PATH, cg_fd, BPF_CGROUP_INET_EGRESS));
     RETURN_IF_NOT_OK(attachProgramToCgroup(BPF_INGRESS_PROG_PATH, cg_fd, BPF_CGROUP_INET_INGRESS));
-
-    // For the devices that support cgroup socket filter, the socket filter
-    // should be loaded successfully by bpfloader. So we attach the filter to
-    // cgroup if the program is pinned properly.
-    // TODO: delete the if statement once all devices should support cgroup
-    // socket filter (ie. the minimum kernel version required is 4.14).
-    if (!access(CGROUP_SOCKET_PROG_PATH, F_OK)) {
-        RETURN_IF_NOT_OK(
-                attachProgramToCgroup(CGROUP_SOCKET_PROG_PATH, cg_fd, BPF_CGROUP_INET_SOCK_CREATE));
-    }
+    RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_SOCKET_PROG_PATH, cg_fd, BPF_CGROUP_INET_SOCK_CREATE));
     return netdutils::status::ok;
 }
 
@@ -111,6 +102,7 @@
     RETURN_IF_NOT_OK(mStatsMapB.init(STATS_MAP_B_PATH));
     RETURN_IF_NOT_OK(mConfigurationMap.init(CONFIGURATION_MAP_PATH));
     RETURN_IF_NOT_OK(mUidPermissionMap.init(UID_PERMISSION_MAP_PATH));
+    ALOGI("%s successfully", __func__);
 
     return netdutils::status::ok;
 }
@@ -241,7 +233,7 @@
     if (sock_cookie == NONEXISTENT_COOKIE) return -errno;
     base::Result<void> res = mCookieTagMap.deleteValue(sock_cookie);
     if (!res.ok()) {
-        ALOGE("Failed to untag socket: %s\n", strerror(res.error().code()));
+        ALOGE("Failed to untag socket: %s", strerror(res.error().code()));
         return -res.error().code();
     }
     return 0;
diff --git a/netd/BpfHandlerTest.cpp b/netd/BpfHandlerTest.cpp
index a031dbb..99160da 100644
--- a/netd/BpfHandlerTest.cpp
+++ b/netd/BpfHandlerTest.cpp
@@ -21,7 +21,7 @@
 
 #include <gtest/gtest.h>
 
-#define TEST_BPF_MAP
+#define BPF_MAP_MAKE_VISIBLE_FOR_TESTING
 #include "BpfHandler.h"
 
 using namespace android::bpf;  // NOLINT(google-build-using-namespace): exempted
@@ -65,7 +65,7 @@
         mFakeConfigurationMap.resetMap(BPF_MAP_TYPE_ARRAY, CONFIGURATION_MAP_SIZE);
         ASSERT_VALID(mFakeConfigurationMap);
 
-        mFakeUidPermissionMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
+        mFakeUidPermissionMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
         ASSERT_VALID(mFakeUidPermissionMap);
 
         mBh.mCookieTagMap = mFakeCookieTagMap;
diff --git a/service-t/native/libs/libnetworkstats/Android.bp b/service-t/native/libs/libnetworkstats/Android.bp
index bf56fd5..5b3d314 100644
--- a/service-t/native/libs/libnetworkstats/Android.bp
+++ b/service-t/native/libs/libnetworkstats/Android.bp
@@ -48,7 +48,8 @@
 
 cc_test {
     name: "libnetworkstats_test",
-    test_suites: ["general-tests"],
+    test_suites: ["general-tests", "mts-tethering"],
+    test_config_template: ":net_native_test_config_template",
     require_root: true,  // required by setrlimitForTest()
     header_libs: ["bpf_connectivity_headers"],
     srcs: [
@@ -68,4 +69,13 @@
         "libbase",
         "liblog",
     ],
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            suffix: "32",
+        },
+        lib64: {
+            suffix: "64",
+        },
+    },
 }
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
index 9ebef4d..6605428 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -58,13 +58,7 @@
 }
 
 int bpfGetUidStats(uid_t uid, Stats* stats) {
-    BpfMapRO<uint32_t, StatsValue> appUidStatsMap(APP_UID_STATS_MAP_PATH);
-
-    if (!appUidStatsMap.isValid()) {
-        int ret = -errno;
-        ALOGE("Opening appUidStatsMap(%s) failed: %s", APP_UID_STATS_MAP_PATH, strerror(errno));
-        return ret;
-    }
+    static BpfMapRO<uint32_t, StatsValue> appUidStatsMap(APP_UID_STATS_MAP_PATH);
     return bpfGetUidStatsInternal(uid, stats, appUidStatsMap);
 }
 
@@ -100,19 +94,8 @@
 }
 
 int bpfGetIfaceStats(const char* iface, Stats* stats) {
-    BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
-    int ret;
-    if (!ifaceStatsMap.isValid()) {
-        ret = -errno;
-        ALOGE("get ifaceStats map fd failed: %s", strerror(errno));
-        return ret;
-    }
-    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
-    if (!ifaceIndexNameMap.isValid()) {
-        ret = -errno;
-        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
-        return ret;
-    }
+    static BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
+    static BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
     return bpfGetIfaceStatsInternal(iface, stats, ifaceStatsMap, ifaceIndexNameMap);
 }
 
@@ -186,32 +169,21 @@
 int parseBpfNetworkStatsDetail(std::vector<stats_line>* lines,
                                const std::vector<std::string>& limitIfaces, int limitTag,
                                int limitUid) {
-    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
-    if (!ifaceIndexNameMap.isValid()) {
-        int ret = -errno;
-        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
-        return ret;
-    }
-
-    BpfMapRO<uint32_t, uint32_t> configurationMap(CONFIGURATION_MAP_PATH);
-    if (!configurationMap.isValid()) {
-        int ret = -errno;
-        ALOGE("get configuration map fd failed: %s", strerror(errno));
-        return ret;
-    }
+    static BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+    static BpfMapRO<uint32_t, uint32_t> configurationMap(CONFIGURATION_MAP_PATH);
     auto configuration = configurationMap.readValue(CURRENT_STATS_MAP_CONFIGURATION_KEY);
     if (!configuration.ok()) {
         ALOGE("Cannot read the old configuration from map: %s",
               configuration.error().message().c_str());
         return -configuration.error().code();
     }
-    const char* statsMapPath = STATS_MAP_PATH[configuration.value()];
-    BpfMap<StatsKey, StatsValue> statsMap(statsMapPath);
-    if (!statsMap.isValid()) {
-        int ret = -errno;
-        ALOGE("get stats map fd failed: %s, path: %s", strerror(errno), statsMapPath);
-        return ret;
+    if (configuration.value() != SELECT_MAP_A && configuration.value() != SELECT_MAP_B) {
+        ALOGE("%s unknown configuration value: %d", __func__, configuration.value());
+        return -EINVAL;
     }
+    const char* statsMapPath = STATS_MAP_PATH[configuration.value()];
+    // TODO: fix this to not constantly reopen the bpf map
+    BpfMap<StatsKey, StatsValue> statsMap(statsMapPath);
 
     // It is safe to read and clear the old map now since the
     // networkStatsFactory should call netd to swap the map in advance already.
@@ -262,20 +234,8 @@
 }
 
 int parseBpfNetworkStatsDev(std::vector<stats_line>* lines) {
-    int ret = 0;
-    BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
-    if (!ifaceIndexNameMap.isValid()) {
-        ret = -errno;
-        ALOGE("get ifaceIndexName map fd failed: %s", strerror(errno));
-        return ret;
-    }
-
-    BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
-    if (!ifaceStatsMap.isValid()) {
-        ret = -errno;
-        ALOGE("get ifaceStats map fd failed: %s", strerror(errno));
-        return ret;
-    }
+    static BpfMapRO<uint32_t, IfaceValue> ifaceIndexNameMap(IFACE_INDEX_NAME_MAP_PATH);
+    static BpfMapRO<uint32_t, StatsValue> ifaceStatsMap(IFACE_STATS_MAP_PATH);
     return parseBpfNetworkStatsDevInternal(lines, ifaceStatsMap, ifaceIndexNameMap);
 }
 
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
index 4974b96..6f9c8c2 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
@@ -33,6 +33,7 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 
+#define BPF_MAP_MAKE_VISIBLE_FOR_TESTING
 #include "bpf/BpfMap.h"
 #include "bpf/BpfUtils.h"
 #include "netdbpf/BpfNetworkStats.h"
@@ -80,19 +81,19 @@
         ASSERT_EQ(0, setrlimitForTest());
 
         mFakeCookieTagMap = BpfMap<uint64_t, UidTagValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
-        ASSERT_LE(0, mFakeCookieTagMap.getMap());
+        ASSERT_TRUE(mFakeCookieTagMap.isValid());
 
         mFakeAppUidStatsMap = BpfMap<uint32_t, StatsValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
-        ASSERT_LE(0, mFakeAppUidStatsMap.getMap());
+        ASSERT_TRUE(mFakeAppUidStatsMap.isValid());
 
         mFakeStatsMap = BpfMap<StatsKey, StatsValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
-        ASSERT_LE(0, mFakeStatsMap.getMap());
+        ASSERT_TRUE(mFakeStatsMap.isValid());
 
         mFakeIfaceIndexNameMap = BpfMap<uint32_t, IfaceValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
-        ASSERT_LE(0, mFakeIfaceIndexNameMap.getMap());
+        ASSERT_TRUE(mFakeIfaceIndexNameMap.isValid());
 
         mFakeIfaceStatsMap = BpfMap<uint32_t, StatsValue>(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE, 0);
-        ASSERT_LE(0, mFakeIfaceStatsMap.getMap());
+        ASSERT_TRUE(mFakeIfaceStatsMap.isValid());
     }
 
     void expectUidTag(uint64_t cookie, uid_t uid, uint32_t tag) {
diff --git a/service-t/src/com/android/server/IpSecService.java b/service-t/src/com/android/server/IpSecService.java
index 4bc40ea..16b9f1e 100644
--- a/service-t/src/com/android/server/IpSecService.java
+++ b/service-t/src/com/android/server/IpSecService.java
@@ -1452,6 +1452,11 @@
         final ConnectivityManager connectivityManager =
                 mContext.getSystemService(ConnectivityManager.class);
         final LinkProperties lp = connectivityManager.getLinkProperties(underlyingNetwork);
+        if (lp == null) {
+            throw new IllegalArgumentException(
+                    "LinkProperties is null. The underlyingNetwork may not be functional");
+        }
+
         if (tunnelInterfaceInfo.getInterfaceName().equals(lp.getInterfaceName())) {
             throw new IllegalArgumentException(
                     "Underlying network cannot be the network being exposed by this tunnel");
diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index 95e6114..8818460 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -21,7 +21,6 @@
 
 import android.content.Context;
 import android.content.Intent;
-import android.content.pm.PackageManager;
 import android.net.ConnectivityManager;
 import android.net.INetd;
 import android.net.LinkProperties;
@@ -51,6 +50,7 @@
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.State;
 import com.android.internal.util.StateMachine;
+import com.android.net.module.util.PermissionUtils;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -101,7 +101,6 @@
     private class NsdStateMachine extends StateMachine {
 
         private final DefaultState mDefaultState = new DefaultState();
-        private final DisabledState mDisabledState = new DisabledState();
         private final EnabledState mEnabledState = new EnabledState();
 
         @Override
@@ -152,7 +151,6 @@
         NsdStateMachine(String name, Handler handler) {
             super(name, handler);
             addState(mDefaultState);
-                addState(mDisabledState, mDefaultState);
                 addState(mEnabledState, mDefaultState);
             State initialState = mEnabledState;
             setInitialState(initialState);
@@ -250,25 +248,6 @@
             }
         }
 
-        class DisabledState extends State {
-            @Override
-            public void enter() {
-                sendNsdStateChangeBroadcast(false);
-            }
-
-            @Override
-            public boolean processMessage(Message msg) {
-                switch (msg.what) {
-                    case NsdManager.ENABLE:
-                        transitionTo(mEnabledState);
-                        break;
-                    default:
-                        return NOT_HANDLED;
-                }
-                return HANDLED;
-            }
-        }
-
         class EnabledState extends State {
             @Override
             public void enter() {
@@ -312,10 +291,6 @@
                 final int clientId = msg.arg2;
                 final ListenerArgs args;
                 switch (msg.what) {
-                    case NsdManager.DISABLE:
-                        //TODO: cleanup clients
-                        transitionTo(mDisabledState);
-                        break;
                     case NsdManager.DISCOVER_SERVICES:
                         if (DBG) Log.d(TAG, "Discover services");
                         args = (ListenerArgs) msg.obj;
@@ -886,12 +861,7 @@
 
     @Override
     public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
-        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
-                != PackageManager.PERMISSION_GRANTED) {
-            pw.println("Permission Denial: can't dump " + TAG
-                    + " due to missing android.permission.DUMP permission");
-            return;
-        }
+        if (!PermissionUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
         for (ClientInfo client : mClients.values()) {
             pw.println("Client Info");
diff --git a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
index c4ea9ae..cedffe1 100644
--- a/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
+++ b/service-t/src/com/android/server/ethernet/EthernetNetworkFactory.java
@@ -60,7 +60,9 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * {@link NetworkProvider} that manages NetworkOffers for Ethernet networks.
+ * Class that manages NetworkOffers for Ethernet networks.
+ *
+ * TODO: this class should be merged into EthernetTracker.
  */
 public class EthernetNetworkFactory {
     private final static String TAG = EthernetNetworkFactory.class.getSimpleName();
@@ -221,11 +223,17 @@
     }
 
     @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
-    protected void removeInterface(String interfaceName) {
+    protected boolean removeInterface(String interfaceName) {
         NetworkInterfaceState iface = mTrackingInterfaces.remove(interfaceName);
         if (iface != null) {
-            iface.destroy();
+            iface.unregisterNetworkOfferAndStop();
+            return true;
         }
+        // TODO(b/236892130): if an interface is currently in server mode, it may not be properly
+        // removed.
+        // TODO: when false is returned, do not send a STATE_ABSENT callback.
+        Log.w(TAG, interfaceName + " is not tracked and cannot be removed");
+        return false;
     }
 
     /** Returns true if state has been modified */
@@ -292,7 +300,7 @@
         private boolean mLinkUp;
         private int mLegacyType;
         private LinkProperties mLinkProperties = new LinkProperties();
-        private Set<NetworkRequest> mRequests = new ArraySet<>();
+        private final Set<Integer> mRequestIds = new ArraySet<>();
 
         private volatile @Nullable IpClientManager mIpClient;
         private @NonNull NetworkCapabilities mCapabilities;
@@ -401,7 +409,7 @@
                 // existing requests.
                 // ConnectivityService filters requests for us based on the NetworkCapabilities
                 // passed in the registerNetworkOffer() call.
-                mRequests.add(request);
+                mRequestIds.add(request.requestId);
                 // if the network is already started, this is a no-op.
                 start();
             }
@@ -412,8 +420,12 @@
                     Log.d(TAG,
                             String.format("%s: onNetworkUnneeded for request: %s", name, request));
                 }
-                mRequests.remove(request);
-                if (mRequests.isEmpty()) {
+                if (!mRequestIds.remove(request.requestId)) {
+                    // This can only happen if onNetworkNeeded was not called for a request or if
+                    // the requestId changed. Both should *never* happen.
+                    Log.wtf(TAG, "onNetworkUnneeded called for unknown request");
+                }
+                if (mRequestIds.isEmpty()) {
                     // not currently serving any requests, stop the network.
                     stop();
                 }
@@ -454,7 +466,7 @@
                     + "transport type.");
         }
 
-        private static NetworkScore getBestNetworkScore() {
+        private static NetworkScore getNetworkScore() {
             return new NetworkScore.Builder().build();
         }
 
@@ -465,9 +477,7 @@
             if (mLinkUp) {
                 // registering a new network offer will update the existing one, not install a
                 // new one.
-                mNetworkProvider.registerNetworkOffer(getBestNetworkScore(),
-                        new NetworkCapabilities(capabilities), cmd -> mHandler.post(cmd),
-                        mNetworkOfferCallback);
+                registerNetworkOffer();
             }
         }
 
@@ -629,14 +639,12 @@
 
             if (!up) { // was up, goes down
                 // retract network offer and stop IpClient.
-                destroy();
+                unregisterNetworkOfferAndStop();
                 // If only setting the interface down, send a callback to signal completion.
                 EthernetNetworkFactory.maybeSendNetworkManagementCallback(listener, name, null);
             } else { // was down, goes up
                 // register network offer
-                mNetworkProvider.registerNetworkOffer(getBestNetworkScore(),
-                        new NetworkCapabilities(mCapabilities), (cmd) -> mHandler.post(cmd),
-                        mNetworkOfferCallback);
+                registerNetworkOffer();
             }
 
             return true;
@@ -660,10 +668,16 @@
             mLinkProperties.clear();
         }
 
-        public void destroy() {
+        private void registerNetworkOffer() {
+            mNetworkProvider.registerNetworkOffer(getNetworkScore(),
+                    new NetworkCapabilities(mCapabilities), cmd -> mHandler.post(cmd),
+                    mNetworkOfferCallback);
+        }
+
+        public void unregisterNetworkOfferAndStop() {
             mNetworkProvider.unregisterNetworkOffer(mNetworkOfferCallback);
             stop();
-            mRequests.clear();
+            mRequestIds.clear();
         }
 
         private static void provisionIpClient(@NonNull final IpClientManager ipClient,
diff --git a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
index 5e830ad..dae3d2a 100644
--- a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
+++ b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
@@ -16,20 +16,22 @@
 
 package com.android.server.ethernet;
 
+import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
 import static android.net.NetworkCapabilities.TRANSPORT_TEST;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.content.pm.PackageManager;
+import android.net.EthernetNetworkSpecifier;
+import android.net.EthernetNetworkUpdateRequest;
 import android.net.IEthernetManager;
 import android.net.IEthernetServiceListener;
 import android.net.INetworkInterfaceOutcomeReceiver;
 import android.net.ITetheredInterfaceCallback;
-import android.net.EthernetNetworkUpdateRequest;
 import android.net.IpConfiguration;
 import android.net.NetworkCapabilities;
-import android.os.Binder;
+import android.net.NetworkSpecifier;
 import android.os.Handler;
 import android.os.RemoteException;
 import android.util.Log;
@@ -185,13 +187,7 @@
     @Override
     protected void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
         final IndentingPrintWriter pw = new IndentingPrintWriter(writer, "  ");
-        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
-                != PackageManager.PERMISSION_GRANTED) {
-            pw.println("Permission Denial: can't dump EthernetService from pid="
-                    + Binder.getCallingPid()
-                    + ", uid=" + Binder.getCallingUid());
-            return;
-        }
+        if (!PermissionUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
         pw.println("Current Ethernet state: ");
         pw.increaseIndent();
@@ -216,19 +212,39 @@
                 "EthernetServiceImpl");
     }
 
-    private void maybeValidateTestCapabilities(final String iface,
-            @Nullable final NetworkCapabilities nc) {
+    private void validateOrSetNetworkSpecifier(String iface, NetworkCapabilities nc) {
+        final NetworkSpecifier spec = nc.getNetworkSpecifier();
+        if (spec == null) {
+            nc.setNetworkSpecifier(new EthernetNetworkSpecifier(iface));
+            return;
+        }
+        if (!(spec instanceof EthernetNetworkSpecifier)) {
+            throw new IllegalArgumentException("Invalid specifier type for request.");
+        }
+        if (!((EthernetNetworkSpecifier) spec).getInterfaceName().matches(iface)) {
+            throw new IllegalArgumentException("Invalid interface name set on specifier.");
+        }
+    }
+
+    private void maybeValidateTestCapabilities(String iface, NetworkCapabilities nc) {
         if (!mTracker.isValidTestInterface(iface)) {
             return;
         }
-        // For test interfaces, only null or capabilities that include TRANSPORT_TEST are
-        // allowed.
-        if (nc != null && !nc.hasTransport(TRANSPORT_TEST)) {
+        if (!nc.hasTransport(TRANSPORT_TEST)) {
             throw new IllegalArgumentException(
                     "Updates to test interfaces must have NetworkCapabilities.TRANSPORT_TEST.");
         }
     }
 
+    private void maybeValidateEthernetTransport(String iface, NetworkCapabilities nc) {
+        if (mTracker.isValidTestInterface(iface)) {
+            return;
+        }
+        if (!nc.hasSingleTransport(TRANSPORT_ETHERNET)) {
+            throw new IllegalArgumentException("Invalid transport type for request.");
+        }
+    }
+
     private void enforceAdminPermission(final String iface, boolean enforceAutomotive,
             final String logMessage) {
         if (mTracker.isValidTestInterface(iface)) {
@@ -251,36 +267,41 @@
 
         // TODO: validate that iface is listed in overlay config_ethernet_interfaces
         // only automotive devices are allowed to set the NetworkCapabilities using this API
-        enforceAdminPermission(iface, request.getNetworkCapabilities() != null,
-                "updateConfiguration() with non-null capabilities");
-        maybeValidateTestCapabilities(iface, request.getNetworkCapabilities());
+        final NetworkCapabilities nc = request.getNetworkCapabilities();
+        enforceAdminPermission(
+                iface, nc != null, "updateConfiguration() with non-null capabilities");
+        if (nc != null) {
+            validateOrSetNetworkSpecifier(iface, nc);
+            maybeValidateTestCapabilities(iface, nc);
+            maybeValidateEthernetTransport(iface, nc);
+        }
 
         mTracker.updateConfiguration(
-                iface, request.getIpConfiguration(), request.getNetworkCapabilities(), listener);
+                iface, request.getIpConfiguration(), nc, listener);
     }
 
     @Override
-    public void connectNetwork(@NonNull final String iface,
+    public void enableInterface(@NonNull final String iface,
             @Nullable final INetworkInterfaceOutcomeReceiver listener) {
-        Log.i(TAG, "connectNetwork called with: iface=" + iface + ", listener=" + listener);
+        Log.i(TAG, "enableInterface called with: iface=" + iface + ", listener=" + listener);
         Objects.requireNonNull(iface);
         throwIfEthernetNotStarted();
 
-        enforceAdminPermission(iface, true, "connectNetwork()");
+        enforceAdminPermission(iface, false, "enableInterface()");
 
-        mTracker.connectNetwork(iface, listener);
+        mTracker.enableInterface(iface, listener);
     }
 
     @Override
-    public void disconnectNetwork(@NonNull final String iface,
+    public void disableInterface(@NonNull final String iface,
             @Nullable final INetworkInterfaceOutcomeReceiver listener) {
-        Log.i(TAG, "disconnectNetwork called with: iface=" + iface + ", listener=" + listener);
+        Log.i(TAG, "disableInterface called with: iface=" + iface + ", listener=" + listener);
         Objects.requireNonNull(iface);
         throwIfEthernetNotStarted();
 
-        enforceAdminPermission(iface, true, "connectNetwork()");
+        enforceAdminPermission(iface, false, "disableInterface()");
 
-        mTracker.disconnectNetwork(iface, listener);
+        mTracker.disableInterface(iface, listener);
     }
 
     @Override
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 1ab7515..31caabc 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -270,6 +270,8 @@
                     + ", ipConfig: " + ipConfig);
         }
 
+        // TODO: do the right thing if the interface was in server mode: either fail this operation,
+        // or take the interface out of server mode.
         final IpConfiguration localIpConfig = ipConfig == null
                 ? null : new IpConfiguration(ipConfig);
         if (ipConfig != null) {
@@ -286,13 +288,13 @@
     }
 
     @VisibleForTesting(visibility = PACKAGE)
-    protected void connectNetwork(@NonNull final String iface,
+    protected void enableInterface(@NonNull final String iface,
             @Nullable final INetworkInterfaceOutcomeReceiver listener) {
         mHandler.post(() -> updateInterfaceState(iface, true, listener));
     }
 
     @VisibleForTesting(visibility = PACKAGE)
-    protected void disconnectNetwork(@NonNull final String iface,
+    protected void disableInterface(@NonNull final String iface,
             @Nullable final INetworkInterfaceOutcomeReceiver listener) {
         mHandler.post(() -> updateInterfaceState(iface, false, listener));
     }
@@ -580,8 +582,8 @@
         }
         if (DBG) Log.i(TAG, "maybeTrackInterface: " + iface);
 
-        // TODO: avoid making an interface default if it has configured NetworkCapabilities.
-        if (mDefaultInterface == null) {
+        // Do not make an interface default if it has configured NetworkCapabilities.
+        if (mDefaultInterface == null && !mNetworkCapabilities.containsKey(iface)) {
             mDefaultInterface = iface;
         }
 
diff --git a/service-t/src/com/android/server/net/NetworkStatsFactory.java b/service-t/src/com/android/server/net/NetworkStatsFactory.java
index 3b93f1a..b628251 100644
--- a/service-t/src/com/android/server/net/NetworkStatsFactory.java
+++ b/service-t/src/com/android/server/net/NetworkStatsFactory.java
@@ -164,16 +164,17 @@
     }
 
     public NetworkStatsFactory(@NonNull Context ctx) {
-        this(ctx, new File("/proc/"), true);
+        this(ctx, new File("/proc/"), true, new BpfNetMaps());
     }
 
     @VisibleForTesting
-    public NetworkStatsFactory(@NonNull Context ctx, File procRoot, boolean useBpfStats) {
+    public NetworkStatsFactory(@NonNull Context ctx, File procRoot, boolean useBpfStats,
+            BpfNetMaps bpfNetMaps) {
         mStatsXtIfaceAll = new File(procRoot, "net/xt_qtaguid/iface_stat_all");
         mStatsXtIfaceFmt = new File(procRoot, "net/xt_qtaguid/iface_stat_fmt");
         mStatsXtUid = new File(procRoot, "net/xt_qtaguid/stats");
         mUseBpfStats = useBpfStats;
-        mBpfNetMaps = new BpfNetMaps();
+        mBpfNetMaps = bpfNetMaps;
         synchronized (mPersistentDataLock) {
             mPersistSnapshot = new NetworkStats(SystemClock.elapsedRealtime(), -1);
             mTunAnd464xlatAdjustedStats = new NetworkStats(SystemClock.elapsedRealtime(), -1);
diff --git a/service-t/src/com/android/server/net/NetworkStatsRecorder.java b/service-t/src/com/android/server/net/NetworkStatsRecorder.java
index 768f3eb..3da1585 100644
--- a/service-t/src/com/android/server/net/NetworkStatsRecorder.java
+++ b/service-t/src/com/android/server/net/NetworkStatsRecorder.java
@@ -43,7 +43,6 @@
 import libcore.io.IoUtils;
 
 import java.io.ByteArrayOutputStream;
-import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -427,46 +426,6 @@
         }
     }
 
-    public void importLegacyNetworkLocked(File file) throws IOException {
-        Objects.requireNonNull(mRotator, "missing FileRotator");
-
-        // legacy file still exists; start empty to avoid double importing
-        mRotator.deleteAll();
-
-        final NetworkStatsCollection collection = new NetworkStatsCollection(mBucketDuration);
-        collection.readLegacyNetwork(file);
-
-        final long startMillis = collection.getStartMillis();
-        final long endMillis = collection.getEndMillis();
-
-        if (!collection.isEmpty()) {
-            // process legacy data, creating active file at starting time, then
-            // using end time to possibly trigger rotation.
-            mRotator.rewriteActive(new CombiningRewriter(collection), startMillis);
-            mRotator.maybeRotate(endMillis);
-        }
-    }
-
-    public void importLegacyUidLocked(File file) throws IOException {
-        Objects.requireNonNull(mRotator, "missing FileRotator");
-
-        // legacy file still exists; start empty to avoid double importing
-        mRotator.deleteAll();
-
-        final NetworkStatsCollection collection = new NetworkStatsCollection(mBucketDuration);
-        collection.readLegacyUid(file, mOnlyTags);
-
-        final long startMillis = collection.getStartMillis();
-        final long endMillis = collection.getEndMillis();
-
-        if (!collection.isEmpty()) {
-            // process legacy data, creating active file at starting time, then
-            // using end time to possibly trigger rotation.
-            mRotator.rewriteActive(new CombiningRewriter(collection), startMillis);
-            mRotator.maybeRotate(endMillis);
-        }
-    }
-
     /**
      * Import a specified {@link NetworkStatsCollection} instance into this recorder,
      * and write it into a standalone file.
@@ -582,7 +541,8 @@
 
     /**
      * Recover from {@link FileRotator} failure by dumping state to
-     * {@link DropBoxManager} and deleting contents.
+     * {@link DropBoxManager} and deleting contents if this recorder
+     * sets {@code mWipeOnError} to true, otherwise keep the contents.
      */
     void recoverAndDeleteData() {
         if (DUMP_BEFORE_DELETE) {
diff --git a/service-t/src/com/android/server/net/NetworkStatsService.java b/service-t/src/com/android/server/net/NetworkStatsService.java
index 4f0f341..e5bd94b 100644
--- a/service-t/src/com/android/server/net/NetworkStatsService.java
+++ b/service-t/src/com/android/server/net/NetworkStatsService.java
@@ -24,7 +24,6 @@
 import static android.content.Intent.ACTION_UID_REMOVED;
 import static android.content.Intent.ACTION_USER_REMOVED;
 import static android.content.Intent.EXTRA_UID;
-import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 import static android.net.NetworkStats.DEFAULT_NETWORK_ALL;
@@ -1677,11 +1676,6 @@
 
     @Override
     public String[] getMobileIfaces() {
-        // TODO (b/192758557): Remove debug log.
-        if (CollectionUtils.contains(mMobileIfaces, null)) {
-            throw new NullPointerException(
-                    "null element in mMobileIfaces: " + Arrays.toString(mMobileIfaces));
-        }
         return mMobileIfaces.clone();
     }
 
@@ -2152,11 +2146,6 @@
         }
 
         mMobileIfaces = mobileIfaces.toArray(new String[0]);
-        // TODO (b/192758557): Remove debug log.
-        if (CollectionUtils.contains(mMobileIfaces, null)) {
-            throw new NullPointerException(
-                    "null element in mMobileIfaces: " + Arrays.toString(mMobileIfaces));
-        }
     }
 
     private static int getSubIdForMobile(@NonNull NetworkStateSnapshot state) {
@@ -2826,24 +2815,6 @@
         return stats;
     }
 
-    // TODO: It is copied from ConnectivityService, consider refactor these check permission
-    //  functions to a proper util.
-    private boolean checkAnyPermissionOf(String... permissions) {
-        for (String permission : permissions) {
-            if (mContext.checkCallingOrSelfPermission(permission) == PERMISSION_GRANTED) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    private void enforceAnyPermissionOf(String... permissions) {
-        if (!checkAnyPermissionOf(permissions)) {
-            throw new SecurityException("Requires one of the following permissions: "
-                    + String.join(", ", permissions) + ".");
-        }
-    }
-
     /**
      * Registers a custom provider of {@link android.net.NetworkStats} to combine the network
      * statistics that cannot be seen by the kernel to system. To unregister, invoke the
@@ -2858,7 +2829,7 @@
      */
     public @NonNull INetworkStatsProviderCallback registerNetworkStatsProvider(
             @NonNull String tag, @NonNull INetworkStatsProvider provider) {
-        enforceAnyPermissionOf(NETWORK_STATS_PROVIDER,
+        PermissionUtils.enforceAnyPermissionOf(mContext, NETWORK_STATS_PROVIDER,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
         Objects.requireNonNull(provider, "provider is null");
         Objects.requireNonNull(tag, "tag is null");
diff --git a/service/Android.bp b/service/Android.bp
index 45e43bc..7a4fb33 100644
--- a/service/Android.bp
+++ b/service/Android.bp
@@ -158,6 +158,7 @@
     static_libs: [
         // Do not add libs here if they are already included
         // in framework-connectivity
+        "connectivity-net-module-utils-bpf",
         "connectivity_native_aidl_interface-lateststable-java",
         "dnsresolver_aidl_interface-V9-java",
         "modules-utils-shell-command-handler",
@@ -181,6 +182,25 @@
     ],
 }
 
+// TODO: Remove this temporary library and put code into module when test coverage is enough.
+java_library {
+    name: "service-mdns",
+    sdk_version: "system_server_current",
+    min_sdk_version: "30",
+    srcs: [
+        "mdns/**/*.java",
+    ],
+    libs: [
+        "framework-annotations-lib",
+        "framework-connectivity-pre-jarjar",
+        "framework-wifi.stubs.module_lib",
+        "service-connectivity-pre-jarjar",
+    ],
+    visibility: [
+        "//packages/modules/Connectivity/tests:__subpackages__",
+    ],
+}
+
 java_library {
     name: "service-connectivity-protos",
     sdk_version: "system_current",
diff --git a/service/ServiceConnectivityResources/res/values-or/strings.xml b/service/ServiceConnectivityResources/res/values-or/strings.xml
index 49a773a..8b85884 100644
--- a/service/ServiceConnectivityResources/res/values-or/strings.xml
+++ b/service/ServiceConnectivityResources/res/values-or/strings.xml
@@ -17,7 +17,7 @@
 
 <resources xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
-    <string name="connectivityResourcesAppLabel" msgid="2476261877900882974">"ସିଷ୍ଟମ କନେକ୍ଟିଭିଟୀ ରିସୋର୍ସ"</string>
+    <string name="connectivityResourcesAppLabel" msgid="2476261877900882974">"ସିଷ୍ଟମର ସଂଯୋଗ ସମ୍ବନ୍ଧିତ ରିସୋର୍ସଗୁଡ଼ିକ"</string>
     <string name="wifi_available_sign_in" msgid="8041178343789805553">"ୱାଇ-ଫାଇ ନେଟୱର୍କରେ ସାଇନ୍‍-ଇନ୍‍ କରନ୍ତୁ"</string>
     <string name="network_available_sign_in" msgid="2622520134876355561">"ନେଟ୍‌ୱର୍କରେ ସାଇନ୍‍ ଇନ୍‍ କରନ୍ତୁ"</string>
     <!-- no translation found for network_available_sign_in_detailed (8439369644697866359) -->
diff --git a/service/ServiceConnectivityResources/res/values-sq/strings.xml b/service/ServiceConnectivityResources/res/values-sq/strings.xml
index 85bd84f..385c75c 100644
--- a/service/ServiceConnectivityResources/res/values-sq/strings.xml
+++ b/service/ServiceConnectivityResources/res/values-sq/strings.xml
@@ -35,7 +35,7 @@
   <string-array name="network_switch_type_name">
     <item msgid="3004933964374161223">"të dhënat celulare"</item>
     <item msgid="5624324321165953608">"Wi-Fi"</item>
-    <item msgid="5667906231066981731">"Bluetooth-i"</item>
+    <item msgid="5667906231066981731">"Bluetooth"</item>
     <item msgid="346574747471703768">"Eternet"</item>
     <item msgid="5734728378097476003">"VPN"</item>
   </string-array>
diff --git a/service/jarjar-excludes.txt b/service/jarjar-excludes.txt
new file mode 100644
index 0000000..b0d6763
--- /dev/null
+++ b/service/jarjar-excludes.txt
@@ -0,0 +1,9 @@
+# Classes loaded by SystemServer via their hardcoded name, so they can't be jarjared
+com\.android\.server\.ConnectivityServiceInitializer(\$.+)?
+com\.android\.server\.NetworkStatsServiceInitializer(\$.+)?
+
+# Do not jarjar com.android.server, as several unit tests fail because they lose
+# package-private visibility between jarjared and non-jarjared classes.
+# TODO: fix the tests and also jarjar com.android.server, or at least only exclude a package that
+# is specific to the module like com.android.server.connectivity
+com\.android\.server\..+
diff --git a/service/jarjar-rules.txt b/service/jarjar-rules.txt
index 4013d2e..1ad75e3 100644
--- a/service/jarjar-rules.txt
+++ b/service/jarjar-rules.txt
@@ -92,7 +92,6 @@
 rule android.net.util.KeepalivePacketDataUtil* com.android.connectivity.@0
 
 # From connectivity-module-utils
-rule android.net.util.SharedLog* com.android.connectivity.@0
 rule android.net.shared.** com.android.connectivity.@0
 
 # From services-connectivity-shared-srcs
diff --git a/service/jni/com_android_server_BpfNetMaps.cpp b/service/jni/com_android_server_BpfNetMaps.cpp
index 7b1f59c..49392e0 100644
--- a/service/jni/com_android_server_BpfNetMaps.cpp
+++ b/service/jni/com_android_server_BpfNetMaps.cpp
@@ -39,152 +39,125 @@
 
 namespace android {
 
-static void native_init(JNIEnv* env, jobject clazz) {
+#define CHECK_LOG(status) \
+  do { \
+    if (!isOk(status)) \
+      ALOGE("%s failed, error code = %d", __func__, status.code()); \
+  } while (0)
+
+static void native_init(JNIEnv* env, jclass clazz) {
   Status status = mTc.start();
-   if (!isOk(status)) {
-    ALOGE("%s failed, error code = %d", __func__, status.code());
-  }
+  CHECK_LOG(status);
 }
 
-static jint native_addNaughtyApp(JNIEnv* env, jobject clazz, jint uid) {
+static jint native_addNaughtyApp(JNIEnv* env, jobject self, jint uid) {
   const uint32_t appUids = static_cast<uint32_t>(abs(uid));
   Status status = mTc.updateUidOwnerMap(appUids, PENALTY_BOX_MATCH,
       TrafficController::IptOp::IptOpInsert);
-  if (!isOk(status)) {
-    ALOGE("%s failed, error code = %d", __func__, status.code());
-  }
+  CHECK_LOG(status);
   return (jint)status.code();
 }
 
-static jint native_removeNaughtyApp(JNIEnv* env, jobject clazz, jint uid) {
+static jint native_removeNaughtyApp(JNIEnv* env, jobject self, jint uid) {
   const uint32_t appUids = static_cast<uint32_t>(abs(uid));
   Status status = mTc.updateUidOwnerMap(appUids, PENALTY_BOX_MATCH,
       TrafficController::IptOp::IptOpDelete);
-  if (!isOk(status)) {
-    ALOGE("%s failed, error code = %d", __func__, status.code());
-  }
+  CHECK_LOG(status);
   return (jint)status.code();
 }
 
-static jint native_addNiceApp(JNIEnv* env, jobject clazz, jint uid) {
+static jint native_addNiceApp(JNIEnv* env, jobject self, jint uid) {
   const uint32_t appUids = static_cast<uint32_t>(abs(uid));
   Status status = mTc.updateUidOwnerMap(appUids, HAPPY_BOX_MATCH,
       TrafficController::IptOp::IptOpInsert);
-  if (!isOk(status)) {
-    ALOGE("%s failed, error code = %d", __func__, status.code());
-  }
+  CHECK_LOG(status);
   return (jint)status.code();
 }
 
-static jint native_removeNiceApp(JNIEnv* env, jobject clazz, jint uid) {
+static jint native_removeNiceApp(JNIEnv* env, jobject self, jint uid) {
   const uint32_t appUids = static_cast<uint32_t>(abs(uid));
   Status status = mTc.updateUidOwnerMap(appUids, HAPPY_BOX_MATCH,
       TrafficController::IptOp::IptOpDelete);
-  if (!isOk(status)) {
-    ALOGD("%s failed, error code = %d", __func__, status.code());
-  }
+  CHECK_LOG(status);
   return (jint)status.code();
 }
 
-static jint native_setChildChain(JNIEnv* env, jobject clazz, jint childChain, jboolean enable) {
-  auto chain = static_cast<ChildChain>(childChain);
-  int res = mTc.toggleUidOwnerMap(chain, enable);
-  if (res) {
-    ALOGE("%s failed, error code = %d", __func__, res);
-  }
-  return (jint)res;
-}
-
-static jint native_replaceUidChain(JNIEnv* env, jobject clazz, jstring name, jboolean isAllowlist,
-                                jintArray jUids) {
+static jint native_replaceUidChain(JNIEnv* env, jobject self, jstring name, jboolean isAllowlist,
+                                   jintArray jUids) {
     const ScopedUtfChars chainNameUtf8(env, name);
-    if (chainNameUtf8.c_str() == nullptr) {
-        return -EINVAL;
-    }
+    if (chainNameUtf8.c_str() == nullptr) return -EINVAL;
     const std::string chainName(chainNameUtf8.c_str());
 
     ScopedIntArrayRO uids(env, jUids);
-    if (uids.get() == nullptr) {
-        return -EINVAL;
-    }
+    if (uids.get() == nullptr) return -EINVAL;
 
     size_t size = uids.size();
     static_assert(sizeof(*(uids.get())) == sizeof(int32_t));
     std::vector<int32_t> data ((int32_t *)&uids[0], (int32_t*)&uids[size]);
     int res = mTc.replaceUidOwnerMap(chainName, isAllowlist, data);
-    if (res) {
-      ALOGE("%s failed, error code = %d", __func__, res);
-    }
+    if (res) ALOGE("%s failed, error code = %d", __func__, res);
     return (jint)res;
 }
 
-static jint native_setUidRule(JNIEnv* env, jobject clazz, jint childChain, jint uid,
-                          jint firewallRule) {
+static jint native_setUidRule(JNIEnv* env, jobject self, jint childChain, jint uid,
+                              jint firewallRule) {
     auto chain = static_cast<ChildChain>(childChain);
     auto rule = static_cast<FirewallRule>(firewallRule);
     FirewallType fType = mTc.getFirewallType(chain);
 
     int res = mTc.changeUidOwnerRule(chain, uid, rule, fType);
-    if (res) {
-      ALOGE("%s failed, error code = %d", __func__, res);
-    }
+    if (res) ALOGE("%s failed, error code = %d", __func__, res);
     return (jint)res;
 }
 
-static jint native_addUidInterfaceRules(JNIEnv* env, jobject clazz, jstring ifName,
-                                    jintArray jUids) {
+static jint native_addUidInterfaceRules(JNIEnv* env, jobject self, jstring ifName,
+                                        jintArray jUids) {
     // Null ifName is a wildcard to allow apps to receive packets on all interfaces and ifIndex is
     // set to 0.
-    int ifIndex;
+    int ifIndex = 0;
     if (ifName != nullptr) {
         const ScopedUtfChars ifNameUtf8(env, ifName);
         const std::string interfaceName(ifNameUtf8.c_str());
         ifIndex = if_nametoindex(interfaceName.c_str());
-    } else {
-        ifIndex = 0;
     }
 
     ScopedIntArrayRO uids(env, jUids);
-    if (uids.get() == nullptr) {
-        return -EINVAL;
-    }
+    if (uids.get() == nullptr) return -EINVAL;
 
     size_t size = uids.size();
     static_assert(sizeof(*(uids.get())) == sizeof(int32_t));
     std::vector<int32_t> data ((int32_t *)&uids[0], (int32_t*)&uids[size]);
     Status status = mTc.addUidInterfaceRules(ifIndex, data);
-    if (!isOk(status)) {
-        ALOGE("%s failed, error code = %d", __func__, status.code());
-    }
+    CHECK_LOG(status);
     return (jint)status.code();
 }
 
-static jint native_removeUidInterfaceRules(JNIEnv* env, jobject clazz, jintArray jUids) {
+static jint native_removeUidInterfaceRules(JNIEnv* env, jobject self, jintArray jUids) {
     ScopedIntArrayRO uids(env, jUids);
-    if (uids.get() == nullptr) {
-        return -EINVAL;
-    }
+    if (uids.get() == nullptr) return -EINVAL;
 
     size_t size = uids.size();
     static_assert(sizeof(*(uids.get())) == sizeof(int32_t));
     std::vector<int32_t> data ((int32_t *)&uids[0], (int32_t*)&uids[size]);
     Status status = mTc.removeUidInterfaceRules(data);
-    if (!isOk(status)) {
-        ALOGE("%s failed, error code = %d", __func__, status.code());
-    }
+    CHECK_LOG(status);
     return (jint)status.code();
 }
 
-static jint native_swapActiveStatsMap(JNIEnv* env, jobject clazz) {
+static jint native_updateUidLockdownRule(JNIEnv* env, jobject self, jint uid, jboolean add) {
+    Status status = mTc.updateUidLockdownRule(uid, add);
+    CHECK_LOG(status);
+    return (jint)status.code();
+}
+
+static jint native_swapActiveStatsMap(JNIEnv* env, jobject self) {
     Status status = mTc.swapActiveStatsMap();
-    if (!isOk(status)) {
-        ALOGD("%s failed, error code = %d", __func__, status.code());
-    }
+    CHECK_LOG(status);
     return (jint)status.code();
 }
 
-static void native_setPermissionForUids(JNIEnv* env, jobject clazz, jint permission,
-                                      jintArray jUids) {
+static void native_setPermissionForUids(JNIEnv* env, jobject self, jint permission,
+                                        jintArray jUids) {
     ScopedIntArrayRO uids(env, jUids);
     if (uids.get() == nullptr) return;
 
@@ -194,7 +167,7 @@
     mTc.setPermissionForUids(permission, data);
 }
 
-static void native_dump(JNIEnv* env, jobject clazz, jobject javaFd, jboolean verbose) {
+static void native_dump(JNIEnv* env, jobject self, jobject javaFd, jboolean verbose) {
     int fd = netjniutils::GetNativeFileDescriptor(env, javaFd);
     if (fd < 0) {
         jniThrowExceptionFmt(env, "java/io/IOException", "Invalid file descriptor");
@@ -219,8 +192,6 @@
     (void*)native_addNiceApp},
     {"native_removeNiceApp", "(I)I",
     (void*)native_removeNiceApp},
-    {"native_setChildChain", "(IZ)I",
-    (void*)native_setChildChain},
     {"native_replaceUidChain", "(Ljava/lang/String;Z[I)I",
     (void*)native_replaceUidChain},
     {"native_setUidRule", "(III)I",
@@ -229,6 +200,8 @@
     (void*)native_addUidInterfaceRules},
     {"native_removeUidInterfaceRules", "([I)I",
     (void*)native_removeUidInterfaceRules},
+    {"native_updateUidLockdownRule", "(IZ)I",
+    (void*)native_updateUidLockdownRule},
     {"native_swapActiveStatsMap", "()I",
     (void*)native_swapActiveStatsMap},
     {"native_setPermissionForUids", "(I[I)V",
@@ -239,9 +212,8 @@
 // clang-format on
 
 int register_com_android_server_BpfNetMaps(JNIEnv* env) {
-    return jniRegisterNativeMethods(env,
-    "com/android/server/BpfNetMaps",
-    gMethods, NELEM(gMethods));
+    return jniRegisterNativeMethods(env, "com/android/server/BpfNetMaps",
+                                    gMethods, NELEM(gMethods));
 }
 
 }; // namespace android
diff --git a/service/jni/com_android_server_TestNetworkService.cpp b/service/jni/com_android_server_TestNetworkService.cpp
index 4efd0e1..9c7a761 100644
--- a/service/jni/com_android_server_TestNetworkService.cpp
+++ b/service/jni/com_android_server_TestNetworkService.cpp
@@ -51,7 +51,15 @@
     jniThrowException(env, "java/lang/IllegalStateException", msg.c_str());
 }
 
-static int createTunTapInterface(JNIEnv* env, bool isTun, const char* iface) {
+// enable or disable  carrier on tun / tap interface.
+static void setTunTapCarrierEnabledImpl(JNIEnv* env, const char* iface, int tunFd, bool enabled) {
+    uint32_t carrierOn = enabled;
+    if (ioctl(tunFd, TUNSETCARRIER, &carrierOn)) {
+        throwException(env, errno, "set carrier", iface);
+    }
+}
+
+static int createTunTapImpl(JNIEnv* env, bool isTun, bool hasCarrier, const char* iface) {
     base::unique_fd tun(open("/dev/tun", O_RDWR | O_NONBLOCK));
     ifreq ifr{};
 
@@ -63,6 +71,11 @@
         return -1;
     }
 
+    if (!hasCarrier) {
+        // disable carrier before setting IFF_UP
+        setTunTapCarrierEnabledImpl(env, iface, tun.get(), hasCarrier);
+    }
+
     // Activate interface using an unconnected datagram socket.
     base::unique_fd inet6CtrlSock(socket(AF_INET6, SOCK_DGRAM, 0));
     ifr.ifr_flags = IFF_UP;
@@ -79,23 +92,31 @@
 
 //------------------------------------------------------------------------------
 
-static jint create(JNIEnv* env, jobject /* thiz */, jboolean isTun, jstring jIface) {
+static void setTunTapCarrierEnabled(JNIEnv* env, jclass /* clazz */, jstring
+                                    jIface, jint tunFd, jboolean enabled) {
+    ScopedUtfChars iface(env, jIface);
+    if (!iface.c_str()) {
+        jniThrowNullPointerException(env, "iface");
+    }
+    setTunTapCarrierEnabledImpl(env, iface.c_str(), tunFd, enabled);
+}
+
+static jint createTunTap(JNIEnv* env, jclass /* clazz */, jboolean isTun,
+                             jboolean hasCarrier, jstring jIface) {
     ScopedUtfChars iface(env, jIface);
     if (!iface.c_str()) {
         jniThrowNullPointerException(env, "iface");
         return -1;
     }
 
-    int tun = createTunTapInterface(env, isTun, iface.c_str());
-
-    // Any exceptions will be thrown from the createTunTapInterface call
-    return tun;
+    return createTunTapImpl(env, isTun, hasCarrier, iface.c_str());
 }
 
 //------------------------------------------------------------------------------
 
 static const JNINativeMethod gMethods[] = {
-    {"jniCreateTunTap", "(ZLjava/lang/String;)I", (void*)create},
+    {"nativeSetTunTapCarrierEnabled", "(Ljava/lang/String;IZ)V", (void*)setTunTapCarrierEnabled},
+    {"nativeCreateTunTap", "(ZZLjava/lang/String;)I", (void*)createTunTap},
 };
 
 int register_com_android_server_TestNetworkService(JNIEnv* env) {
diff --git a/service/jni/com_android_server_connectivity_ClatCoordinator.cpp b/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
index ba836b2..e2c5a63 100644
--- a/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
+++ b/service/jni/com_android_server_connectivity_ClatCoordinator.cpp
@@ -315,10 +315,7 @@
 
     // TODO: use android::base::ScopeGuard.
     if (int ret = posix_spawnattr_setflags(&attr, POSIX_SPAWN_USEVFORK
-#ifdef POSIX_SPAWN_CLOEXEC_DEFAULT
-                                           | POSIX_SPAWN_CLOEXEC_DEFAULT
-#endif
-                                           )) {
+                                           | POSIX_SPAWN_CLOEXEC_DEFAULT)) {
         posix_spawnattr_destroy(&attr);
         throwIOException(env, "posix_spawnattr_setflags failed", ret);
         return -1;
diff --git a/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitor.java b/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitor.java
new file mode 100644
index 0000000..2b99d0a
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitor.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+/** Interface for monitoring connectivity changes. */
+public interface ConnectivityMonitor {
+    /**
+     * Starts monitoring changes of connectivity of this device, which may indicate that the list of
+     * network interfaces available for multi-cast messaging has changed.
+     */
+    void startWatchingConnectivityChanges();
+
+    /** Stops monitoring changes of connectivity. */
+    void stopWatchingConnectivityChanges();
+
+    void notifyConnectivityChange();
+
+    /** Listener interface for receiving connectivity changes. */
+    interface Listener {
+        void onConnectivityChanged();
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManager.java b/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManager.java
new file mode 100644
index 0000000..3563d61
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManager.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkRequest;
+import android.os.Build;
+
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+/** Class for monitoring connectivity changes using {@link ConnectivityManager}. */
+public class ConnectivityMonitorWithConnectivityManager implements ConnectivityMonitor {
+    private static final String TAG = "ConnMntrWConnMgr";
+    private static final MdnsLogger LOGGER = new MdnsLogger(TAG);
+
+    private final Listener listener;
+    private final ConnectivityManager.NetworkCallback networkCallback;
+    private final ConnectivityManager connectivityManager;
+    // TODO(b/71901993): Ideally we shouldn't need this flag. However we still don't have clues why
+    // the receiver is unregistered twice yet.
+    private boolean isCallbackRegistered = false;
+
+    @SuppressWarnings({"nullness:assignment", "nullness:method.invocation"})
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public ConnectivityMonitorWithConnectivityManager(Context context, Listener listener) {
+        this.listener = listener;
+
+        connectivityManager =
+                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+        networkCallback =
+                new ConnectivityManager.NetworkCallback() {
+                    @Override
+                    public void onAvailable(Network network) {
+                        LOGGER.log("network available.");
+                        notifyConnectivityChange();
+                    }
+
+                    @Override
+                    public void onLost(Network network) {
+                        LOGGER.log("network lost.");
+                        notifyConnectivityChange();
+                    }
+
+                    @Override
+                    public void onUnavailable() {
+                        LOGGER.log("network unavailable.");
+                        notifyConnectivityChange();
+                    }
+                };
+    }
+
+    @Override
+    public void notifyConnectivityChange() {
+        listener.onConnectivityChanged();
+    }
+
+    /**
+     * Starts monitoring changes of connectivity of this device, which may indicate that the list of
+     * network interfaces available for multi-cast messaging has changed.
+     */
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    @Override
+    public void startWatchingConnectivityChanges() {
+        LOGGER.log("Start watching connectivity changes");
+        if (isCallbackRegistered) {
+            return;
+        }
+
+        connectivityManager.registerNetworkCallback(
+                new NetworkRequest.Builder().addTransportType(
+                        NetworkCapabilities.TRANSPORT_WIFI).build(),
+                networkCallback);
+        isCallbackRegistered = true;
+    }
+
+    /** Stops monitoring changes of connectivity. */
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    @Override
+    public void stopWatchingConnectivityChanges() {
+        LOGGER.log("Stop watching connectivity changes");
+        if (!isCallbackRegistered) {
+            return;
+        }
+
+        connectivityManager.unregisterNetworkCallback(networkCallback);
+        isCallbackRegistered = false;
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java b/service/mdns/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java
new file mode 100644
index 0000000..3db1b22
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/EnqueueMdnsQueryCallable.java
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.text.TextUtils;
+import android.util.Pair;
+
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.io.IOException;
+import java.lang.ref.WeakReference;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.Callable;
+
+/**
+ * A {@link Callable} that builds and enqueues a mDNS query to send over the multicast socket. If a
+ * query is built and enqueued successfully, then call to {@link #call()} returns the transaction ID
+ * and the list of the subtypes in the query as a {@link Pair}. If a query is failed to build, or if
+ * it can not be enqueued, then call to {@link #call()} returns {@code null}.
+ */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class EnqueueMdnsQueryCallable implements Callable<Pair<Integer, List<String>>> {
+
+    private static final String TAG = "MdnsQueryCallable";
+    private static final MdnsLogger LOGGER = new MdnsLogger(TAG);
+    private static final List<Integer> castShellEmulatorMdnsPorts;
+
+    static {
+        castShellEmulatorMdnsPorts = new ArrayList<>();
+        String[] stringPorts = MdnsConfigs.castShellEmulatorMdnsPorts();
+
+        for (String port : stringPorts) {
+            try {
+                castShellEmulatorMdnsPorts.add(Integer.parseInt(port));
+            } catch (NumberFormatException e) {
+                // Ignore.
+            }
+        }
+    }
+
+    private final WeakReference<MdnsSocketClient> weakRequestSender;
+    private final MdnsPacketWriter packetWriter;
+    private final String[] serviceTypeLabels;
+    private final List<String> subtypes;
+    private final boolean expectUnicastResponse;
+    private final int transactionId;
+
+    EnqueueMdnsQueryCallable(
+            @NonNull MdnsSocketClient requestSender,
+            @NonNull MdnsPacketWriter packetWriter,
+            @NonNull String serviceType,
+            @NonNull Collection<String> subtypes,
+            boolean expectUnicastResponse,
+            int transactionId) {
+        weakRequestSender = new WeakReference<>(requestSender);
+        this.packetWriter = packetWriter;
+        serviceTypeLabels = TextUtils.split(serviceType, "\\.");
+        this.subtypes = new ArrayList<>(subtypes);
+        this.expectUnicastResponse = expectUnicastResponse;
+        this.transactionId = transactionId;
+    }
+
+    @Override
+    public Pair<Integer, List<String>> call() {
+        try {
+            MdnsSocketClient requestSender = weakRequestSender.get();
+            if (requestSender == null) {
+                return null;
+            }
+
+            int numQuestions = 1;
+            if (!subtypes.isEmpty()) {
+                numQuestions += subtypes.size();
+            }
+
+            // Header.
+            packetWriter.writeUInt16(transactionId); // transaction ID
+            packetWriter.writeUInt16(MdnsConstants.FLAGS_QUERY); // flags
+            packetWriter.writeUInt16(numQuestions); // number of questions
+            packetWriter.writeUInt16(0); // number of answers (not yet known; will be written later)
+            packetWriter.writeUInt16(0); // number of authority entries
+            packetWriter.writeUInt16(0); // number of additional records
+
+            // Question(s). There will be one question for each (fqdn+subtype, recordType)
+          // combination,
+            // as well as one for each (fqdn, recordType) combination.
+
+            for (String subtype : subtypes) {
+                String[] labels = new String[serviceTypeLabels.length + 2];
+                labels[0] = MdnsConstants.SUBTYPE_PREFIX + subtype;
+                labels[1] = MdnsConstants.SUBTYPE_LABEL;
+                System.arraycopy(serviceTypeLabels, 0, labels, 2, serviceTypeLabels.length);
+
+                packetWriter.writeLabels(labels);
+                packetWriter.writeUInt16(MdnsRecord.TYPE_PTR);
+                packetWriter.writeUInt16(
+                        MdnsConstants.QCLASS_INTERNET
+                                | (expectUnicastResponse ? MdnsConstants.QCLASS_UNICAST : 0));
+            }
+
+            packetWriter.writeLabels(serviceTypeLabels);
+            packetWriter.writeUInt16(MdnsRecord.TYPE_PTR);
+            packetWriter.writeUInt16(
+                    MdnsConstants.QCLASS_INTERNET
+                            | (expectUnicastResponse ? MdnsConstants.QCLASS_UNICAST : 0));
+
+            InetAddress mdnsAddress = MdnsConstants.getMdnsIPv4Address();
+            if (requestSender.isOnIPv6OnlyNetwork()) {
+                mdnsAddress = MdnsConstants.getMdnsIPv6Address();
+            }
+
+            sendPacketTo(requestSender,
+                    new InetSocketAddress(mdnsAddress, MdnsConstants.MDNS_PORT));
+            for (Integer emulatorPort : castShellEmulatorMdnsPorts) {
+                sendPacketTo(requestSender, new InetSocketAddress(mdnsAddress, emulatorPort));
+            }
+            return Pair.create(transactionId, subtypes);
+        } catch (IOException e) {
+            LOGGER.e(String.format("Failed to create mDNS packet for subtype: %s.",
+                    TextUtils.join(",", subtypes)), e);
+            return null;
+        }
+    }
+
+    private void sendPacketTo(MdnsSocketClient requestSender, InetSocketAddress address)
+            throws IOException {
+        DatagramPacket packet = packetWriter.getPacket(address);
+        if (expectUnicastResponse) {
+            requestSender.sendUnicastPacket(packet);
+        } else {
+            requestSender.sendMulticastPacket(packet);
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/ExecutorProvider.java b/service/mdns/com/android/server/connectivity/mdns/ExecutorProvider.java
new file mode 100644
index 0000000..72b65e0
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/ExecutorProvider.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.util.ArraySet;
+
+import java.util.Set;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+
+/**
+ * This class provides {@link ScheduledExecutorService} instances to {@link MdnsServiceTypeClient}
+ * instances, and provides method to shutdown all the created executors.
+ */
+public class ExecutorProvider {
+
+    private final Set<ScheduledExecutorService> serviceTypeClientSchedulerExecutors =
+            new ArraySet<>();
+
+    /** Returns a new {@link ScheduledExecutorService} instance. */
+    public ScheduledExecutorService newServiceTypeClientSchedulerExecutor() {
+        // TODO: actually use a pool ?
+        ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1);
+        serviceTypeClientSchedulerExecutors.add(executor);
+        return executor;
+    }
+
+    /** Shuts down all the created {@link ScheduledExecutorService} instances. */
+    public void shutdownAll() {
+        for (ScheduledExecutorService executor : serviceTypeClientSchedulerExecutors) {
+            executor.shutdownNow();
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsConfigs.java b/service/mdns/com/android/server/connectivity/mdns/MdnsConfigs.java
new file mode 100644
index 0000000..922037b
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsConfigs.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+/**
+ * mDNS configuration values.
+ *
+ * TODO: consider making some of these adjustable via flags.
+ */
+public class MdnsConfigs {
+    public static String[] castShellEmulatorMdnsPorts() {
+        return new String[0];
+    }
+
+    public static long initialTimeBetweenBurstsMs() {
+        return 5000L;
+    }
+
+    public static long timeBetweenBurstsMs() {
+        return 20_000L;
+    }
+
+    public static int queriesPerBurst() {
+        return 3;
+    }
+
+    public static long timeBetweenQueriesInBurstMs() {
+        return 1000L;
+    }
+
+    public static int queriesPerBurstPassive() {
+        return 1;
+    }
+
+    public static boolean alwaysAskForUnicastResponseInEachBurst() {
+        return false;
+    }
+
+    public static boolean useSessionIdToScheduleMdnsTask() {
+        return false;
+    }
+
+    public static boolean shouldCancelScanTaskWhenFutureIsNull() {
+        return false;
+    }
+
+    public static long sleepTimeForSocketThreadMs() {
+        return 20_000L;
+    }
+
+    public static boolean checkMulticastResponse() {
+        return false;
+    }
+
+    public static boolean useSeparateSocketToSendUnicastQuery() {
+        return false;
+    }
+
+    public static long checkMulticastResponseIntervalMs() {
+        return 10_000L;
+    }
+
+    public static boolean clearMdnsPacketQueueAfterDiscoveryStops() {
+        return true;
+    }
+
+    public static boolean allowAddMdnsPacketAfterDiscoveryStops() {
+        return false;
+    }
+
+    public static int mdnsPacketQueueMaxSize() {
+        return Integer.MAX_VALUE;
+    }
+
+    public static boolean preferIpv6() {
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsConstants.java b/service/mdns/com/android/server/connectivity/mdns/MdnsConstants.java
new file mode 100644
index 0000000..ed28700
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsConstants.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+
+/** mDNS-related constants. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+@VisibleForTesting
+public final class MdnsConstants {
+    public static final int MDNS_PORT = 5353;
+    // Flags word format is:
+    // 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
+    // QR [ Opcode  ] AA TC RD RA  Z AD CD [  Rcode  ]
+    // See http://www.networksorcery.com/enp/protocol/dns.htm
+    // For responses, QR bit should be 1, AA - CD bits should be ignored, and all other bits
+    // should be 0.
+    public static final int FLAGS_QUERY = 0x0000;
+    public static final int FLAGS_RESPONSE_MASK = 0xF80F;
+    public static final int FLAGS_RESPONSE = 0x8000;
+    public static final int QCLASS_INTERNET = 0x0001;
+    public static final int QCLASS_UNICAST = 0x8000;
+    public static final String SUBTYPE_LABEL = "_sub";
+    public static final String SUBTYPE_PREFIX = "_";
+    private static final String MDNS_IPV4_HOST_ADDRESS = "224.0.0.251";
+    private static final String MDNS_IPV6_HOST_ADDRESS = "FF02::FB";
+    private static InetAddress mdnsAddress;
+    private static Charset utf8Charset;
+    private MdnsConstants() {
+    }
+
+    public static InetAddress getMdnsIPv4Address() {
+        synchronized (MdnsConstants.class) {
+            InetAddress addr = null;
+            try {
+                addr = InetAddress.getByName(MDNS_IPV4_HOST_ADDRESS);
+            } catch (UnknownHostException e) {
+                /* won't happen */
+            }
+            mdnsAddress = addr;
+            return mdnsAddress;
+        }
+    }
+
+    public static InetAddress getMdnsIPv6Address() {
+        synchronized (MdnsConstants.class) {
+            InetAddress addr = null;
+            try {
+                addr = InetAddress.getByName(MDNS_IPV6_HOST_ADDRESS);
+            } catch (UnknownHostException e) {
+                /* won't happen */
+            }
+            mdnsAddress = addr;
+            return mdnsAddress;
+        }
+    }
+
+    public static Charset getUtf8Charset() {
+        synchronized (MdnsConstants.class) {
+            if (utf8Charset == null) {
+                utf8Charset = getUtf8CharsetOnKitKat();
+            }
+            return utf8Charset;
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.KITKAT)
+    private static Charset getUtf8CharsetOnKitKat() {
+        return StandardCharsets.UTF_8;
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsDiscoveryManager.java b/service/mdns/com/android/server/connectivity/mdns/MdnsDiscoveryManager.java
new file mode 100644
index 0000000..1faa6ce
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsDiscoveryManager.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.Manifest.permission;
+import android.annotation.NonNull;
+import android.annotation.RequiresPermission;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Map;
+
+/**
+ * This class keeps tracking the set of registered {@link MdnsServiceBrowserListener} instances, and
+ * notify them when a mDNS service instance is found, updated, or removed?
+ */
+public class MdnsDiscoveryManager implements MdnsSocketClient.Callback {
+
+    private static final MdnsLogger LOGGER = new MdnsLogger("MdnsDiscoveryManager");
+
+    private final ExecutorProvider executorProvider;
+    private final MdnsSocketClient socketClient;
+
+    private final Map<String, MdnsServiceTypeClient> serviceTypeClients = new ArrayMap<>();
+
+    public MdnsDiscoveryManager(
+            @NonNull ExecutorProvider executorProvider, @NonNull MdnsSocketClient socketClient) {
+        this.executorProvider = executorProvider;
+        this.socketClient = socketClient;
+    }
+
+    /**
+     * Starts (or continue) to discovery mDNS services with given {@code serviceType}, and registers
+     * {@code listener} for receiving mDNS service discovery responses.
+     *
+     * @param serviceType   The type of the service to discover.
+     * @param listener      The {@link MdnsServiceBrowserListener} listener.
+     * @param searchOptions The {@link MdnsSearchOptions} to be used for discovering {@code
+     *                      serviceType}.
+     */
+    @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+    public synchronized void registerListener(
+            @NonNull String serviceType,
+            @NonNull MdnsServiceBrowserListener listener,
+            @NonNull MdnsSearchOptions searchOptions) {
+        LOGGER.log(
+                "Registering listener for subtypes: %s",
+                TextUtils.join(",", searchOptions.getSubtypes()));
+        if (serviceTypeClients.isEmpty()) {
+            // First listener. Starts the socket client.
+            try {
+                socketClient.startDiscovery();
+            } catch (IOException e) {
+                LOGGER.e("Failed to start discover.", e);
+                return;
+            }
+        }
+        // All listeners of the same service types shares the same MdnsServiceTypeClient.
+        MdnsServiceTypeClient serviceTypeClient = serviceTypeClients.get(serviceType);
+        if (serviceTypeClient == null) {
+            serviceTypeClient = createServiceTypeClient(serviceType);
+            serviceTypeClients.put(serviceType, serviceTypeClient);
+        }
+        serviceTypeClient.startSendAndReceive(listener, searchOptions);
+    }
+
+    /**
+     * Unregister {@code listener} for receiving mDNS service discovery responses. IF no listener is
+     * registered for the given service type, stops discovery for the service type.
+     *
+     * @param serviceType The type of the service to discover.
+     * @param listener    The {@link MdnsServiceBrowserListener} listener.
+     */
+    @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+    public synchronized void unregisterListener(
+            @NonNull String serviceType, @NonNull MdnsServiceBrowserListener listener) {
+        LOGGER.log("Unregistering listener for service type: %s", serviceType);
+        MdnsServiceTypeClient serviceTypeClient = serviceTypeClients.get(serviceType);
+        if (serviceTypeClient == null) {
+            return;
+        }
+        if (serviceTypeClient.stopSendAndReceive(listener)) {
+            // No listener is registered for the service type anymore, remove it from the list of
+          // the
+            // service type clients.
+            serviceTypeClients.remove(serviceType);
+            if (serviceTypeClients.isEmpty()) {
+                // No discovery request. Stops the socket client.
+                socketClient.stopDiscovery();
+            }
+        }
+    }
+
+    @Override
+    public synchronized void onResponseReceived(@NonNull MdnsResponse response) {
+        String[] name =
+                response.getPointerRecords().isEmpty()
+                        ? null
+                        : response.getPointerRecords().get(0).getName();
+        if (name != null) {
+            for (MdnsServiceTypeClient serviceTypeClient : serviceTypeClients.values()) {
+                String[] serviceType = serviceTypeClient.getServiceTypeLabels();
+                if ((Arrays.equals(name, serviceType)
+                        || ((name.length == (serviceType.length + 2))
+                        && name[1].equals(MdnsConstants.SUBTYPE_LABEL)
+                        && MdnsRecord.labelsAreSuffix(serviceType, name)))) {
+                    serviceTypeClient.processResponse(response);
+                    return;
+                }
+            }
+        }
+    }
+
+    @Override
+    public synchronized void onFailedToParseMdnsResponse(int receivedPacketNumber, int errorCode) {
+        for (MdnsServiceTypeClient serviceTypeClient : serviceTypeClients.values()) {
+            serviceTypeClient.onFailedToParseMdnsResponse(receivedPacketNumber, errorCode);
+        }
+    }
+
+    @VisibleForTesting
+    MdnsServiceTypeClient createServiceTypeClient(@NonNull String serviceType) {
+        return new MdnsServiceTypeClient(
+                serviceType, socketClient,
+                executorProvider.newServiceTypeClientSchedulerExecutor());
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsInetAddressRecord.java b/service/mdns/com/android/server/connectivity/mdns/MdnsInetAddressRecord.java
new file mode 100644
index 0000000..e35743c
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsInetAddressRecord.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Locale;
+import java.util.Objects;
+
+/** An mDNS "AAAA" or "A" record, which holds an IPv6 or IPv4 address. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+@VisibleForTesting
+public class MdnsInetAddressRecord extends MdnsRecord {
+    private Inet6Address inet6Address;
+    private Inet4Address inet4Address;
+
+    /**
+     * Constructs the {@link MdnsRecord}
+     *
+     * @param name   the service host name
+     * @param type   the type of record (either Type 'AAAA' or Type 'A')
+     * @param reader the reader to read the record from.
+     */
+    public MdnsInetAddressRecord(String[] name, int type, MdnsPacketReader reader)
+            throws IOException {
+        super(name, type, reader);
+    }
+
+    /** Returns the IPv6 address. */
+    public Inet6Address getInet6Address() {
+        return inet6Address;
+    }
+
+    /** Returns the IPv4 address. */
+    public Inet4Address getInet4Address() {
+        return inet4Address;
+    }
+
+    @Override
+    protected void readData(MdnsPacketReader reader) throws IOException {
+        int size = 4;
+        if (super.getType() == MdnsRecord.TYPE_AAAA) {
+            size = 16;
+        }
+        byte[] buf = new byte[size];
+        reader.readBytes(buf);
+        try {
+            InetAddress address = InetAddress.getByAddress(buf);
+            if (address instanceof Inet4Address) {
+                inet4Address = (Inet4Address) address;
+                inet6Address = null;
+            } else if (address instanceof Inet6Address) {
+                inet4Address = null;
+                inet6Address = (Inet6Address) address;
+            } else {
+                inet4Address = null;
+                inet6Address = null;
+            }
+        } catch (UnknownHostException e) {
+            // Ignore exception
+        }
+    }
+
+    @Override
+    protected void writeData(MdnsPacketWriter writer) throws IOException {
+        byte[] buf = null;
+        if (inet4Address != null) {
+            buf = inet4Address.getAddress();
+        } else if (inet6Address != null) {
+            buf = inet6Address.getAddress();
+        }
+        if (buf != null) {
+            writer.writeBytes(buf);
+        }
+    }
+
+    @Override
+    public String toString() {
+        String type = "AAAA";
+        if (super.getType() == MdnsRecord.TYPE_A) {
+            type = "A";
+        }
+        return String.format(
+                Locale.ROOT, "%s: Inet4Address: %s Inet6Address: %s", type, inet4Address,
+                inet6Address);
+    }
+
+    @Override
+    public int hashCode() {
+        return (super.hashCode() * 31)
+                + Objects.hashCode(inet4Address)
+                + Objects.hashCode(inet6Address);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (!(other instanceof MdnsInetAddressRecord)) {
+            return false;
+        }
+
+        return super.equals(other)
+                && Objects.equals(inet4Address, ((MdnsInetAddressRecord) other).inet4Address)
+                && Objects.equals(inet6Address, ((MdnsInetAddressRecord) other).inet6Address);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsPacketReader.java b/service/mdns/com/android/server/connectivity/mdns/MdnsPacketReader.java
new file mode 100644
index 0000000..61c5f5a
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsPacketReader.java
@@ -0,0 +1,254 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.util.SparseArray;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+/** Simple decoder for mDNS packets. */
+public class MdnsPacketReader {
+    private final byte[] buf;
+    private final int count;
+    private final SparseArray<LabelEntry> labelDictionary;
+    private int pos;
+    private int limit;
+
+    /** Constructs a reader for the given packet. */
+    public MdnsPacketReader(DatagramPacket packet) {
+        buf = packet.getData();
+        count = packet.getLength();
+        pos = 0;
+        limit = -1;
+        labelDictionary = new SparseArray<>(16);
+    }
+
+    /**
+     * Sets a temporary limit (from the current read position) for subsequent reads. Any attempt to
+     * read past this limit will result in an EOFException.
+     *
+     * @param limit The new limit.
+     * @throws IOException If there is insufficient data for the new limit.
+     */
+    public void setLimit(int limit) throws IOException {
+        if (limit >= 0) {
+            if (pos + limit <= count) {
+                this.limit = pos + limit;
+            } else {
+                throw new IOException(
+                        String.format(
+                                Locale.ROOT,
+                                "attempt to set limit beyond available data: %d exceeds %d",
+                                pos + limit,
+                                count));
+            }
+        }
+    }
+
+    /** Clears the limit set by {@link #setLimit}. */
+    public void clearLimit() {
+        limit = -1;
+    }
+
+    /**
+     * Returns the number of bytes left to read, between the current read position and either the
+     * limit (if set) or the end of the packet.
+     */
+    public int getRemaining() {
+        return (limit >= 0 ? limit : count) - pos;
+    }
+
+    /**
+     * Reads an unsigned 8-bit integer.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public int readUInt8() throws EOFException {
+        checkRemaining(1);
+        byte val = buf[pos++];
+        return val & 0xFF;
+    }
+
+    /**
+     * Reads an unsigned 16-bit integer.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public int readUInt16() throws EOFException {
+        checkRemaining(2);
+        int val = (buf[pos++] & 0xFF) << 8;
+        val |= (buf[pos++]) & 0xFF;
+        return val;
+    }
+
+    /**
+     * Reads an unsigned 32-bit integer.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public long readUInt32() throws EOFException {
+        checkRemaining(4);
+        long val = (long) (buf[pos++] & 0xFF) << 24;
+        val |= (long) (buf[pos++] & 0xFF) << 16;
+        val |= (long) (buf[pos++] & 0xFF) << 8;
+        val |= buf[pos++] & 0xFF;
+        return val;
+    }
+
+    /**
+     * Reads a sequence of labels and returns them as an array of strings. A sequence of labels is
+     * either a sequence of strings terminated by a NUL byte, a sequence of strings terminated by a
+     * pointer, or a pointer.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     * @throws IOException  If invalid data is read.
+     */
+    public String[] readLabels() throws IOException {
+        List<String> result = new ArrayList<>(5);
+        LabelEntry previousEntry = null;
+
+        while (getRemaining() > 0) {
+            byte nextByte = peekByte();
+
+            if (nextByte == 0) {
+                // A NUL byte terminates a sequence of labels.
+                skip(1);
+                break;
+            }
+
+            int currentOffset = pos;
+
+            boolean isLabelPointer = (nextByte & 0xC0) == 0xC0;
+            if (isLabelPointer) {
+                // A pointer terminates a sequence of labels. Store the pointer value in the
+                // previous label entry.
+                int labelOffset = ((readUInt8() & 0x3F) << 8) | (readUInt8() & 0xFF);
+                if (previousEntry != null) {
+                    previousEntry.nextOffset = labelOffset;
+                }
+
+                // Follow the chain of labels starting at this pointer, adding all of them onto the
+                // result.
+                while (labelOffset != 0) {
+                    LabelEntry entry = labelDictionary.get(labelOffset);
+                    if (entry == null) {
+                        throw new IOException(
+                                String.format(Locale.ROOT, "Invalid label pointer: %04X",
+                                        labelOffset));
+                    }
+                    result.add(entry.label);
+                    labelOffset = entry.nextOffset;
+                }
+                break;
+            } else {
+                // It's an ordinary label. Chain it onto the previous label entry (if any), and add
+                // it onto the result.
+                String val = readString();
+                LabelEntry newEntry = new LabelEntry(val);
+                labelDictionary.put(currentOffset, newEntry);
+
+                if (previousEntry != null) {
+                    previousEntry.nextOffset = currentOffset;
+                }
+                previousEntry = newEntry;
+                result.add(val);
+            }
+        }
+
+        return result.toArray(new String[result.size()]);
+    }
+
+    /**
+     * Reads a length-prefixed string.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public String readString() throws EOFException {
+        int len = readUInt8();
+        checkRemaining(len);
+        String val = new String(buf, pos, len, MdnsConstants.getUtf8Charset());
+        pos += len;
+        return val;
+    }
+
+    /**
+     * Reads a specific number of bytes.
+     *
+     * @param bytes The array to fill.
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public void readBytes(byte[] bytes) throws EOFException {
+        checkRemaining(bytes.length);
+        System.arraycopy(buf, pos, bytes, 0, bytes.length);
+        pos += bytes.length;
+    }
+
+    /**
+     * Skips over the given number of bytes.
+     *
+     * @param count The number of bytes to read and discard.
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public void skip(int count) throws EOFException {
+        checkRemaining(count);
+        pos += count;
+    }
+
+    /**
+     * Peeks at and returns the next byte in the packet, without advancing the read position.
+     *
+     * @throws EOFException If there are not enough bytes remaining in the packet to satisfy the
+     *                      read.
+     */
+    public byte peekByte() throws EOFException {
+        checkRemaining(1);
+        return buf[pos];
+    }
+
+    /** Returns the current byte position of the reader for the data packet. */
+    public int getPosition() {
+        return pos;
+    }
+
+    // Checks if the number of remaining bytes to be read in the packet is at least |count|.
+    private void checkRemaining(int count) throws EOFException {
+        if (getRemaining() < count) {
+            throw new EOFException();
+        }
+    }
+
+    private static class LabelEntry {
+        public final String label;
+        public int nextOffset = 0;
+
+        public LabelEntry(String label) {
+            this.label = label;
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsPacketWriter.java b/service/mdns/com/android/server/connectivity/mdns/MdnsPacketWriter.java
new file mode 100644
index 0000000..2fed36d
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsPacketWriter.java
@@ -0,0 +1,223 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.SocketAddress;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+/** Simple encoder for mDNS packets. */
+public class MdnsPacketWriter {
+    private static final int MDNS_POINTER_MASK = 0xC000;
+    private final byte[] data;
+    private final Map<Integer, String[]> labelDictionary;
+    private int pos = 0;
+    private int savedWritePos = -1;
+
+    /**
+     * Constructs a writer for a new packet.
+     *
+     * @param maxSize The maximum size of a packet.
+     */
+    public MdnsPacketWriter(int maxSize) {
+        if (maxSize <= 0) {
+            throw new IllegalArgumentException("invalid size");
+        }
+
+        data = new byte[maxSize];
+        labelDictionary = new HashMap<>();
+    }
+
+    /** Returns the current write position. */
+    public int getWritePosition() {
+        return pos;
+    }
+
+    /**
+     * Saves the current write position and then rewinds the write position by the given number of
+     * bytes. This is useful for updating length fields earlier in the packet. Rewinds cannot be
+     * nested.
+     *
+     * @param position The position to rewind to.
+     * @throws IOException If the count would go beyond the beginning of the packet, or if there is
+     *                     already a rewind in effect.
+     */
+    public void rewind(int position) throws IOException {
+        if ((savedWritePos != -1) || (position > pos) || (position < 0)) {
+            throw new IOException("invalid rewind");
+        }
+
+        savedWritePos = pos;
+        pos = position;
+    }
+
+    /**
+     * Sets the current write position to what it was prior to the last rewind.
+     *
+     * @throws IOException If there was no rewind in effect.
+     */
+    public void unrewind() throws IOException {
+        if (savedWritePos == -1) {
+            throw new IOException("no rewind is in effect");
+        }
+        pos = savedWritePos;
+        savedWritePos = -1;
+    }
+
+    /** Clears any rewind state. */
+    public void clearRewind() {
+        savedWritePos = -1;
+    }
+
+    /**
+     * Writes an unsigned 8-bit integer.
+     *
+     * @param value The value to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeUInt8(int value) throws IOException {
+        checkRemaining(1);
+        data[pos++] = (byte) (value & 0xFF);
+    }
+
+    /**
+     * Writes an unsigned 16-bit integer.
+     *
+     * @param value The value to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeUInt16(int value) throws IOException {
+        checkRemaining(2);
+        data[pos++] = (byte) ((value >>> 8) & 0xFF);
+        data[pos++] = (byte) (value & 0xFF);
+    }
+
+    /**
+     * Writes an unsigned 32-bit integer.
+     *
+     * @param value The value to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeUInt32(long value) throws IOException {
+        checkRemaining(4);
+        data[pos++] = (byte) ((value >>> 24) & 0xFF);
+        data[pos++] = (byte) ((value >>> 16) & 0xFF);
+        data[pos++] = (byte) ((value >>> 8) & 0xFF);
+        data[pos++] = (byte) (value & 0xFF);
+    }
+
+    /**
+     * Writes a specific number of bytes.
+     *
+     * @param data The array to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeBytes(byte[] data) throws IOException {
+        checkRemaining(data.length);
+        System.arraycopy(data, 0, this.data, pos, data.length);
+        pos += data.length;
+    }
+
+    /**
+     * Writes a string.
+     *
+     * @param value The string to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeString(String value) throws IOException {
+        byte[] utf8 = value.getBytes(MdnsConstants.getUtf8Charset());
+        writeUInt8(utf8.length);
+        writeBytes(utf8);
+    }
+
+    /**
+     * Writes a series of labels. Uses name compression.
+     *
+     * @param labels The labels to write.
+     * @throws IOException If there is not enough space remaining in the packet.
+     */
+    public void writeLabels(String[] labels) throws IOException {
+        // See section 4.1.4 of RFC 1035 (http://tools.ietf.org/html/rfc1035) for a description
+        // of the name compression method used here.
+
+        int suffixLength = 0;
+        int suffixPointer = 0;
+
+        for (Map.Entry<Integer, String[]> entry : labelDictionary.entrySet()) {
+            int existingOffset = entry.getKey();
+            String[] existingLabels = entry.getValue();
+
+            if (Arrays.equals(existingLabels, labels)) {
+                writePointer(existingOffset);
+                return;
+            } else if (MdnsRecord.labelsAreSuffix(existingLabels, labels)) {
+                // Keep track of the longest matching suffix so far.
+                if (existingLabels.length > suffixLength) {
+                    suffixLength = existingLabels.length;
+                    suffixPointer = existingOffset;
+                }
+            }
+        }
+
+        if (suffixLength > 0) {
+            for (int i = 0; i < (labels.length - suffixLength); ++i) {
+                writeString(labels[i]);
+            }
+            writePointer(suffixPointer);
+        } else {
+            int[] offsets = new int[labels.length];
+            for (int i = 0; i < labels.length; ++i) {
+                offsets[i] = getWritePosition();
+                writeString(labels[i]);
+            }
+            writeUInt8(0); // NUL terminator
+
+            // Add entries to the label dictionary for each suffix of the label list, including
+            // the whole list itself.
+            for (int i = 0, len = labels.length; i < labels.length; ++i, --len) {
+                String[] value = new String[len];
+                System.arraycopy(labels, i, value, 0, len);
+                labelDictionary.put(offsets[i], value);
+            }
+        }
+    }
+
+    /** Returns the number of bytes that can still be written. */
+    public int getRemaining() {
+        return data.length - pos;
+    }
+
+    // Writes a pointer to a label.
+    private void writePointer(int offset) throws IOException {
+        writeUInt16(MDNS_POINTER_MASK | offset);
+    }
+
+    // Checks if the remaining space in the packet is at least |count|.
+    private void checkRemaining(int count) throws IOException {
+        if (getRemaining() < count) {
+            throw new IOException();
+        }
+    }
+
+    /** Builds and returns the packet. */
+    public DatagramPacket getPacket(SocketAddress destAddress) throws IOException {
+        return new DatagramPacket(data, pos, destAddress);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsPointerRecord.java b/service/mdns/com/android/server/connectivity/mdns/MdnsPointerRecord.java
new file mode 100644
index 0000000..2b36a3c
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsPointerRecord.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+/** An mDNS "PTR" record, which holds a name (the "pointer"). */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+@VisibleForTesting
+public class MdnsPointerRecord extends MdnsRecord {
+    private String[] pointer;
+
+    public MdnsPointerRecord(String[] name, MdnsPacketReader reader) throws IOException {
+        super(name, TYPE_PTR, reader);
+    }
+
+    /** Returns the pointer as an array of labels. */
+    public String[] getPointer() {
+        return pointer;
+    }
+
+    @Override
+    protected void readData(MdnsPacketReader reader) throws IOException {
+        pointer = reader.readLabels();
+    }
+
+    @Override
+    protected void writeData(MdnsPacketWriter writer) throws IOException {
+        writer.writeLabels(pointer);
+    }
+
+    public boolean hasSubtype() {
+        return (name != null) && (name.length > 2) && name[1].equals(MdnsConstants.SUBTYPE_LABEL);
+    }
+
+    public String getSubtype() {
+        return hasSubtype() ? name[0] : null;
+    }
+
+    @Override
+    public String toString() {
+        return "PTR: " + labelsToString(name) + " -> " + labelsToString(pointer);
+    }
+
+    @Override
+    public int hashCode() {
+        return (super.hashCode() * 31) + Arrays.hashCode(pointer);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (!(other instanceof MdnsPointerRecord)) {
+            return false;
+        }
+
+        return super.equals(other) && Arrays.equals(pointer, ((MdnsPointerRecord) other).pointer);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsRecord.java b/service/mdns/com/android/server/connectivity/mdns/MdnsRecord.java
new file mode 100644
index 0000000..4bfdb2c
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsRecord.java
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.os.SystemClock;
+import android.text.TextUtils;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Abstract base class for mDNS records. Stores the header fields and provides methods for reading
+ * the record from and writing it to a packet.
+ */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public abstract class MdnsRecord {
+    public static final int TYPE_A = 0x0001;
+    public static final int TYPE_AAAA = 0x001C;
+    public static final int TYPE_PTR = 0x000C;
+    public static final int TYPE_SRV = 0x0021;
+    public static final int TYPE_TXT = 0x0010;
+
+    /** Status indicating that the record is current. */
+    public static final int STATUS_OK = 0;
+    /** Status indicating that the record has expired (TTL reached 0). */
+    public static final int STATUS_EXPIRED = 1;
+    /** Status indicating that the record should be refreshed (Less than half of TTL remains.) */
+    public static final int STATUS_NEEDS_REFRESH = 2;
+
+    protected final String[] name;
+    private final int type;
+    private final int cls;
+    private final long receiptTimeMillis;
+    private final long ttlMillis;
+    private Object key;
+
+    /**
+     * Constructs a new record with the given name and type.
+     *
+     * @param reader The reader to read the record from.
+     * @throws IOException If an error occurs while reading the packet.
+     */
+    protected MdnsRecord(String[] name, int type, MdnsPacketReader reader) throws IOException {
+        this.name = name;
+        this.type = type;
+        cls = reader.readUInt16();
+        ttlMillis = TimeUnit.SECONDS.toMillis(reader.readUInt32());
+        int dataLength = reader.readUInt16();
+
+        receiptTimeMillis = SystemClock.elapsedRealtime();
+
+        reader.setLimit(dataLength);
+        readData(reader);
+        reader.clearLimit();
+    }
+
+    /**
+     * Converts an array of labels into their dot-separated string representation. This method
+     * should
+     * be used for logging purposes only.
+     */
+    public static String labelsToString(String[] labels) {
+        if (labels == null) {
+            return null;
+        }
+        return TextUtils.join(".", labels);
+    }
+
+    /** Tests if |list1| is a suffix of |list2|. */
+    public static boolean labelsAreSuffix(String[] list1, String[] list2) {
+        int offset = list2.length - list1.length;
+
+        if (offset < 1) {
+            return false;
+        }
+
+        for (int i = 0; i < list1.length; ++i) {
+            if (!list1[i].equals(list2[i + offset])) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /** Returns the record's receipt (creation) time. */
+    public final long getReceiptTime() {
+        return receiptTimeMillis;
+    }
+
+    /** Returns the record's name. */
+    public String[] getName() {
+        return name;
+    }
+
+    /** Returns the record's original TTL, in milliseconds. */
+    public final long getTtl() {
+        return ttlMillis;
+    }
+
+    /** Returns the record's type. */
+    public final int getType() {
+        return type;
+    }
+
+    /**
+     * Returns the record's remaining TTL.
+     *
+     * @param now The current system time.
+     * @return The remaning TTL, in milliseconds.
+     */
+    public long getRemainingTTL(final long now) {
+        long age = now - receiptTimeMillis;
+        if (age > ttlMillis) {
+            return 0;
+        }
+
+        return ttlMillis - age;
+    }
+
+    /**
+     * Reads the record's payload from a packet.
+     *
+     * @param reader The reader to use.
+     * @throws IOException If an I/O error occurs.
+     */
+    protected abstract void readData(MdnsPacketReader reader) throws IOException;
+
+    /**
+     * Writes the record to a packet.
+     *
+     * @param writer The writer to use.
+     * @param now    The current system time. This is used when writing the updated TTL.
+     */
+    @VisibleForTesting
+    public final void write(MdnsPacketWriter writer, long now) throws IOException {
+        writer.writeLabels(name);
+        writer.writeUInt16(type);
+        writer.writeUInt16(cls);
+
+        writer.writeUInt32(TimeUnit.MILLISECONDS.toSeconds(getRemainingTTL(now)));
+
+        int dataLengthPos = writer.getWritePosition();
+        writer.writeUInt16(0); // data length
+        int dataPos = writer.getWritePosition();
+
+        writeData(writer);
+
+        // Calculate amount of data written, and overwrite the data field earlier in the packet.
+        int endPos = writer.getWritePosition();
+        int dataLength = endPos - dataPos;
+        writer.rewind(dataLengthPos);
+        writer.writeUInt16(dataLength);
+        writer.unrewind();
+    }
+
+    /**
+     * Writes the record's payload to a packet.
+     *
+     * @param writer The writer to use.
+     * @throws IOException If an I/O error occurs.
+     */
+    protected abstract void writeData(MdnsPacketWriter writer) throws IOException;
+
+    /** Gets the status of the record. */
+    public int getStatus(final long now) {
+        final long age = now - receiptTimeMillis;
+        if (age > ttlMillis) {
+            return STATUS_EXPIRED;
+        }
+        if (age > (ttlMillis / 2)) {
+            return STATUS_NEEDS_REFRESH;
+        }
+        return STATUS_OK;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (!(other instanceof MdnsRecord)) {
+            return false;
+        }
+
+        MdnsRecord otherRecord = (MdnsRecord) other;
+
+        return Arrays.equals(name, otherRecord.name) && (type == otherRecord.type);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(Arrays.hashCode(name), type);
+    }
+
+    /**
+     * Returns an opaque object that uniquely identifies this record through a combination of its
+     * type
+     * and name. Suitable for use as a key in caches.
+     */
+    public final Object getKey() {
+        if (key == null) {
+            key = new Key(type, name);
+        }
+        return key;
+    }
+
+    private static final class Key {
+        private final int recordType;
+        private final String[] recordName;
+
+        public Key(int recordType, String[] recordName) {
+            this.recordType = recordType;
+            this.recordName = recordName;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            if (this == other) {
+                return true;
+            }
+            if (!(other instanceof Key)) {
+                return false;
+            }
+
+            Key otherKey = (Key) other;
+
+            return (recordType == otherKey.recordType) && Arrays.equals(recordName,
+                    otherKey.recordName);
+        }
+
+        @Override
+        public int hashCode() {
+            return (recordType * 31) + Arrays.hashCode(recordName);
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsResponse.java b/service/mdns/com/android/server/connectivity/mdns/MdnsResponse.java
new file mode 100644
index 0000000..1305e07
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsResponse.java
@@ -0,0 +1,380 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+/** An mDNS response. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class MdnsResponse {
+    private final List<MdnsRecord> records;
+    private final List<MdnsPointerRecord> pointerRecords;
+    private MdnsServiceRecord serviceRecord;
+    private MdnsTextRecord textRecord;
+    private MdnsInetAddressRecord inet4AddressRecord;
+    private MdnsInetAddressRecord inet6AddressRecord;
+    private long lastUpdateTime;
+
+    /** Constructs a new, empty response. */
+    public MdnsResponse(long now) {
+        lastUpdateTime = now;
+        records = new LinkedList<>();
+        pointerRecords = new LinkedList<>();
+    }
+
+    // This generic typed helper compares records for equality.
+    // Returns True if records are the same.
+    private <T> boolean recordsAreSame(T a, T b) {
+        return ((a == null) && (b == null)) || ((a != null) && (b != null) && a.equals(b));
+    }
+
+    /**
+     * Adds a pointer record.
+     *
+     * @return <code>true</code> if the record was added, or <code>false</code> if a matching
+     * pointer
+     * record is already present in the response.
+     */
+    public synchronized boolean addPointerRecord(MdnsPointerRecord pointerRecord) {
+        if (!pointerRecords.contains(pointerRecord)) {
+            pointerRecords.add(pointerRecord);
+            records.add(pointerRecord);
+            return true;
+        }
+
+        return false;
+    }
+
+    /** Gets the pointer records. */
+    public synchronized List<MdnsPointerRecord> getPointerRecords() {
+        // Returns a shallow copy.
+        return new LinkedList<>(pointerRecords);
+    }
+
+    public synchronized boolean hasPointerRecords() {
+        return !pointerRecords.isEmpty();
+    }
+
+    @VisibleForTesting
+    /* package */ synchronized void clearPointerRecords() {
+        pointerRecords.clear();
+    }
+
+    public synchronized boolean hasSubtypes() {
+        for (MdnsPointerRecord pointerRecord : pointerRecords) {
+            if (pointerRecord.hasSubtype()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public synchronized List<String> getSubtypes() {
+        List<String> subtypes = null;
+
+        for (MdnsPointerRecord pointerRecord : pointerRecords) {
+            if (pointerRecord.hasSubtype()) {
+                if (subtypes == null) {
+                    subtypes = new LinkedList<>();
+                }
+                subtypes.add(pointerRecord.getSubtype());
+            }
+        }
+
+        return subtypes;
+    }
+
+    @VisibleForTesting
+    public synchronized void removeSubtypes() {
+        Iterator<MdnsPointerRecord> iter = pointerRecords.iterator();
+        while (iter.hasNext()) {
+            MdnsPointerRecord pointerRecord = iter.next();
+            if (pointerRecord.hasSubtype()) {
+                iter.remove();
+            }
+        }
+    }
+
+    /** Sets the service record. */
+    public synchronized boolean setServiceRecord(MdnsServiceRecord serviceRecord) {
+        if (recordsAreSame(this.serviceRecord, serviceRecord)) {
+            return false;
+        }
+        if (this.serviceRecord != null) {
+            records.remove(this.serviceRecord);
+        }
+        this.serviceRecord = serviceRecord;
+        if (this.serviceRecord != null) {
+            records.add(this.serviceRecord);
+        }
+        return true;
+    }
+
+    /** Gets the service record. */
+    public synchronized MdnsServiceRecord getServiceRecord() {
+        return serviceRecord;
+    }
+
+    public synchronized boolean hasServiceRecord() {
+        return serviceRecord != null;
+    }
+
+    /** Sets the text record. */
+    public synchronized boolean setTextRecord(MdnsTextRecord textRecord) {
+        if (recordsAreSame(this.textRecord, textRecord)) {
+            return false;
+        }
+        if (this.textRecord != null) {
+            records.remove(this.textRecord);
+        }
+        this.textRecord = textRecord;
+        if (this.textRecord != null) {
+            records.add(this.textRecord);
+        }
+        return true;
+    }
+
+    /** Gets the text record. */
+    public synchronized MdnsTextRecord getTextRecord() {
+        return textRecord;
+    }
+
+    public synchronized boolean hasTextRecord() {
+        return textRecord != null;
+    }
+
+    /** Sets the IPv4 address record. */
+    public synchronized boolean setInet4AddressRecord(MdnsInetAddressRecord newInet4AddressRecord) {
+        if (recordsAreSame(this.inet4AddressRecord, newInet4AddressRecord)) {
+            return false;
+        }
+        if (this.inet4AddressRecord != null) {
+            records.remove(this.inet4AddressRecord);
+        }
+        if (newInet4AddressRecord != null && newInet4AddressRecord.getInet4Address() != null) {
+            this.inet4AddressRecord = newInet4AddressRecord;
+            records.add(this.inet4AddressRecord);
+        }
+        return true;
+    }
+
+    /** Gets the IPv4 address record. */
+    public synchronized MdnsInetAddressRecord getInet4AddressRecord() {
+        return inet4AddressRecord;
+    }
+
+    public synchronized boolean hasInet4AddressRecord() {
+        return inet4AddressRecord != null;
+    }
+
+    /** Sets the IPv6 address record. */
+    public synchronized boolean setInet6AddressRecord(MdnsInetAddressRecord newInet6AddressRecord) {
+        if (recordsAreSame(this.inet6AddressRecord, newInet6AddressRecord)) {
+            return false;
+        }
+        if (this.inet6AddressRecord != null) {
+            records.remove(this.inet6AddressRecord);
+        }
+        if (newInet6AddressRecord != null && newInet6AddressRecord.getInet6Address() != null) {
+            this.inet6AddressRecord = newInet6AddressRecord;
+            records.add(this.inet6AddressRecord);
+        }
+        return true;
+    }
+
+
+    /** Gets the IPv6 address record. */
+    public synchronized MdnsInetAddressRecord getInet6AddressRecord() {
+        return inet6AddressRecord;
+    }
+
+    public synchronized boolean hasInet6AddressRecord() {
+        return inet6AddressRecord != null;
+    }
+
+    /** Gets all of the records. */
+    public synchronized List<MdnsRecord> getRecords() {
+        return new LinkedList<>(records);
+    }
+
+    /**
+     * Merges any records that are present in another response into this one.
+     *
+     * @return <code>true</code> if any records were added or updated.
+     */
+    public synchronized boolean mergeRecordsFrom(MdnsResponse other) {
+        lastUpdateTime = other.lastUpdateTime;
+
+        boolean updated = false;
+
+        List<MdnsPointerRecord> pointerRecords = other.getPointerRecords();
+        if (pointerRecords != null) {
+            for (MdnsPointerRecord pointerRecord : pointerRecords) {
+                if (addPointerRecord(pointerRecord)) {
+                    updated = true;
+                }
+            }
+        }
+
+        MdnsServiceRecord serviceRecord = other.getServiceRecord();
+        if (serviceRecord != null) {
+            if (setServiceRecord(serviceRecord)) {
+                updated = true;
+            }
+        }
+
+        MdnsTextRecord textRecord = other.getTextRecord();
+        if (textRecord != null) {
+            if (setTextRecord(textRecord)) {
+                updated = true;
+            }
+        }
+
+        MdnsInetAddressRecord otherInet4AddressRecord = other.getInet4AddressRecord();
+        if (otherInet4AddressRecord != null && otherInet4AddressRecord.getInet4Address() != null) {
+            if (setInet4AddressRecord(otherInet4AddressRecord)) {
+                updated = true;
+            }
+        }
+
+        MdnsInetAddressRecord otherInet6AddressRecord = other.getInet6AddressRecord();
+        if (otherInet6AddressRecord != null && otherInet6AddressRecord.getInet6Address() != null) {
+            if (setInet6AddressRecord(otherInet6AddressRecord)) {
+                updated = true;
+            }
+        }
+
+        // If the hostname in the service record no longer matches the hostname in either of the
+        // address records, then drop the address records.
+        if (this.serviceRecord != null) {
+            boolean dropAddressRecords = false;
+
+            if (this.inet4AddressRecord != null) {
+                if (!Arrays.equals(
+                        this.serviceRecord.getServiceHost(), this.inet4AddressRecord.getName())) {
+                    dropAddressRecords = true;
+                }
+            }
+            if (this.inet6AddressRecord != null) {
+                if (!Arrays.equals(
+                        this.serviceRecord.getServiceHost(), this.inet6AddressRecord.getName())) {
+                    dropAddressRecords = true;
+                }
+            }
+
+            if (dropAddressRecords) {
+                setInet4AddressRecord(null);
+                setInet6AddressRecord(null);
+                updated = true;
+            }
+        }
+
+        return updated;
+    }
+
+    /**
+     * Tests if the response is complete. A response is considered complete if it contains PTR, SRV,
+     * TXT, and A (for IPv4) or AAAA (for IPv6) records.
+     */
+    public synchronized boolean isComplete() {
+        return !pointerRecords.isEmpty()
+                && (serviceRecord != null)
+                && (textRecord != null)
+                && (inet4AddressRecord != null || inet6AddressRecord != null);
+    }
+
+    /**
+     * Returns the key for this response. The key uniquely identifies the response by its service
+     * name.
+     */
+    public synchronized String getServiceInstanceName() {
+        if (pointerRecords.isEmpty()) {
+            return null;
+        }
+        String[] pointers = pointerRecords.get(0).getPointer();
+        return ((pointers != null) && (pointers.length > 0)) ? pointers[0] : null;
+    }
+
+    /**
+     * Tests if this response is a goodbye message. This will be true if a service record is present
+     * and any of the records have a TTL of 0.
+     */
+    public synchronized boolean isGoodbye() {
+        if (getServiceInstanceName() != null) {
+            for (MdnsRecord record : records) {
+                // Expiring PTR records with subtypes just signal a change in known supported
+                // criteria, not the device itself going offline, so ignore those.
+                if ((record instanceof MdnsPointerRecord)
+                        && ((MdnsPointerRecord) record).hasSubtype()) {
+                    continue;
+                }
+
+                if (record.getTtl() == 0) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Writes the response to a packet.
+     *
+     * @param writer The writer to use.
+     * @param now    The current time. This is used to write updated TTLs that reflect the remaining
+     *               TTL
+     *               since the response was received.
+     * @return The number of records that were written.
+     * @throws IOException If an error occurred while writing (typically indicating overflow).
+     */
+    public synchronized int write(MdnsPacketWriter writer, long now) throws IOException {
+        int count = 0;
+        for (MdnsPointerRecord pointerRecord : pointerRecords) {
+            pointerRecord.write(writer, now);
+            ++count;
+        }
+
+        if (serviceRecord != null) {
+            serviceRecord.write(writer, now);
+            ++count;
+        }
+
+        if (textRecord != null) {
+            textRecord.write(writer, now);
+            ++count;
+        }
+
+        if (inet4AddressRecord != null) {
+            inet4AddressRecord.write(writer, now);
+            ++count;
+        }
+
+        if (inet6AddressRecord != null) {
+            inet6AddressRecord.write(writer, now);
+            ++count;
+        }
+
+        return count;
+    }
+}
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsResponseDecoder.java b/service/mdns/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
new file mode 100644
index 0000000..72c3156
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.os.SystemClock;
+
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+/** A class that decodes mDNS responses from UDP packets. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class MdnsResponseDecoder {
+
+    public static final int SUCCESS = 0;
+    private static final String TAG = "MdnsResponseDecoder";
+    private static final MdnsLogger LOGGER = new MdnsLogger(TAG);
+    private final String[] serviceType;
+    private final Clock clock;
+
+    /** Constructs a new decoder that will extract responses for the given service type. */
+    public MdnsResponseDecoder(@NonNull Clock clock, @Nullable String[] serviceType) {
+        this.clock = clock;
+        this.serviceType = serviceType;
+    }
+
+    private static void skipMdnsRecord(MdnsPacketReader reader) throws IOException {
+        reader.skip(2 + 4); // skip the class and TTL
+        int dataLength = reader.readUInt16();
+        reader.skip(dataLength);
+    }
+
+    private static MdnsResponse findResponseWithPointer(
+            List<MdnsResponse> responses, String[] pointer) {
+        if (responses != null) {
+            for (MdnsResponse response : responses) {
+                List<MdnsPointerRecord> pointerRecords = response.getPointerRecords();
+                if (pointerRecords == null) {
+                    continue;
+                }
+                for (MdnsPointerRecord pointerRecord : pointerRecords) {
+                    if (Arrays.equals(pointerRecord.getPointer(), pointer)) {
+                        return response;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    private static MdnsResponse findResponseWithHostName(
+            List<MdnsResponse> responses, String[] hostName) {
+        if (responses != null) {
+            for (MdnsResponse response : responses) {
+                MdnsServiceRecord serviceRecord = response.getServiceRecord();
+                if (serviceRecord == null) {
+                    continue;
+                }
+                if (Arrays.equals(serviceRecord.getServiceHost(), hostName)) {
+                    return response;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Decodes all mDNS responses for the desired service type from a packet. The class does not
+     * check
+     * the responses for completeness; the caller should do that.
+     *
+     * @param packet The packet to read from.
+     * @return A list of mDNS responses, or null if the packet contained no appropriate responses.
+     */
+    public int decode(@NonNull DatagramPacket packet, @NonNull List<MdnsResponse> responses) {
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        List<MdnsRecord> records;
+        try {
+            reader.readUInt16(); // transaction ID (not used)
+            int flags = reader.readUInt16();
+            if ((flags & MdnsConstants.FLAGS_RESPONSE_MASK) != MdnsConstants.FLAGS_RESPONSE) {
+                return MdnsResponseErrorCode.ERROR_NOT_RESPONSE_MESSAGE;
+            }
+
+            int numQuestions = reader.readUInt16();
+            int numAnswers = reader.readUInt16();
+            int numAuthority = reader.readUInt16();
+            int numRecords = reader.readUInt16();
+
+            LOGGER.log(String.format(
+                    "num questions: %d, num answers: %d, num authority: %d, num records: %d",
+                    numQuestions, numAnswers, numAuthority, numRecords));
+
+            if (numAnswers < 1) {
+                return MdnsResponseErrorCode.ERROR_NO_ANSWERS;
+            }
+
+            records = new LinkedList<>();
+
+            for (int i = 0; i < (numAnswers + numAuthority + numRecords); ++i) {
+                String[] name;
+                try {
+                    name = reader.readLabels();
+                } catch (IOException e) {
+                    LOGGER.e("Failed to read labels from mDNS response.", e);
+                    return MdnsResponseErrorCode.ERROR_READING_RECORD_NAME;
+                }
+                int type = reader.readUInt16();
+
+                switch (type) {
+                    case MdnsRecord.TYPE_A: {
+                        try {
+                            records.add(new MdnsInetAddressRecord(name, MdnsRecord.TYPE_A, reader));
+                        } catch (IOException e) {
+                            LOGGER.e("Failed to read A record from mDNS response.", e);
+                            return MdnsResponseErrorCode.ERROR_READING_A_RDATA;
+                        }
+                        break;
+                    }
+
+                    case MdnsRecord.TYPE_AAAA: {
+                        try {
+                            // AAAA should only contain the IPv6 address.
+                            MdnsInetAddressRecord record =
+                                    new MdnsInetAddressRecord(name, MdnsRecord.TYPE_AAAA, reader);
+                            if (record.getInet6Address() != null) {
+                                records.add(record);
+                            }
+                        } catch (IOException e) {
+                            LOGGER.e("Failed to read AAAA record from mDNS response.", e);
+                            return MdnsResponseErrorCode.ERROR_READING_AAAA_RDATA;
+                        }
+                        break;
+                    }
+
+                    case MdnsRecord.TYPE_PTR: {
+                        try {
+                            records.add(new MdnsPointerRecord(name, reader));
+                        } catch (IOException e) {
+                            LOGGER.e("Failed to read PTR record from mDNS response.", e);
+                            return MdnsResponseErrorCode.ERROR_READING_PTR_RDATA;
+                        }
+                        break;
+                    }
+
+                    case MdnsRecord.TYPE_SRV: {
+                        if (name.length == 4) {
+                            try {
+                                records.add(new MdnsServiceRecord(name, reader));
+                            } catch (IOException e) {
+                                LOGGER.e("Failed to read SRV record from mDNS response.", e);
+                                return MdnsResponseErrorCode.ERROR_READING_SRV_RDATA;
+                            }
+                        } else {
+                            try {
+                                skipMdnsRecord(reader);
+                            } catch (IOException e) {
+                                LOGGER.e("Failed to skip SVR record from mDNS response.", e);
+                                return MdnsResponseErrorCode.ERROR_SKIPPING_SRV_RDATA;
+                            }
+                        }
+                        break;
+                    }
+
+                    case MdnsRecord.TYPE_TXT: {
+                        try {
+                            records.add(new MdnsTextRecord(name, reader));
+                        } catch (IOException e) {
+                            LOGGER.e("Failed to read TXT record from mDNS response.", e);
+                            return MdnsResponseErrorCode.ERROR_READING_TXT_RDATA;
+                        }
+                        break;
+                    }
+
+                    default: {
+                        try {
+                            skipMdnsRecord(reader);
+                        } catch (IOException e) {
+                            LOGGER.e("Failed to skip mDNS record.", e);
+                            return MdnsResponseErrorCode.ERROR_SKIPPING_UNKNOWN_RECORD;
+                        }
+                    }
+                }
+            }
+        } catch (EOFException e) {
+            LOGGER.e("Reached the end of the mDNS response unexpectedly.", e);
+            return MdnsResponseErrorCode.ERROR_END_OF_FILE;
+        }
+
+        // The response records are structured in a hierarchy, where some records reference
+        // others, as follows:
+        //
+        //        PTR
+        //        / \
+        //       /   \
+        //      TXT  SRV
+        //           / \
+        //          /   \
+        //         A   AAAA
+        //
+        // But the order in which these records appear in the response packet is completely
+        // arbitrary. This means that we need to rescan the record list to construct each level of
+        // this hierarchy.
+        //
+        // PTR: service type -> service instance name
+        //
+        // SRV: service instance name -> host name (priority, weight)
+        //
+        // TXT: service instance name -> machine readable txt entries.
+        //
+        // A: host name -> IP address
+
+        // Loop 1: find PTR records, which identify distinct service instances.
+        long now = SystemClock.elapsedRealtime();
+        for (MdnsRecord record : records) {
+            if (record instanceof MdnsPointerRecord) {
+                String[] name = record.getName();
+                if ((serviceType == null)
+                        || Arrays.equals(name, serviceType)
+                        || ((name.length == (serviceType.length + 2))
+                        && name[1].equals(MdnsConstants.SUBTYPE_LABEL)
+                        && MdnsRecord.labelsAreSuffix(serviceType, name))) {
+                    MdnsPointerRecord pointerRecord = (MdnsPointerRecord) record;
+                    // Group PTR records that refer to the same service instance name into a single
+                    // response.
+                    MdnsResponse response = findResponseWithPointer(responses,
+                            pointerRecord.getPointer());
+                    if (response == null) {
+                        response = new MdnsResponse(now);
+                        responses.add(response);
+                    }
+                    response.addPointerRecord((MdnsPointerRecord) record);
+                }
+            }
+        }
+
+        // Loop 2: find SRV and TXT records, which reference the pointer in the PTR record.
+        for (MdnsRecord record : records) {
+            if (record instanceof MdnsServiceRecord) {
+                MdnsServiceRecord serviceRecord = (MdnsServiceRecord) record;
+                MdnsResponse response = findResponseWithPointer(responses, serviceRecord.getName());
+                if (response != null) {
+                    response.setServiceRecord(serviceRecord);
+                }
+            } else if (record instanceof MdnsTextRecord) {
+                MdnsTextRecord textRecord = (MdnsTextRecord) record;
+                MdnsResponse response = findResponseWithPointer(responses, textRecord.getName());
+                if (response != null) {
+                    response.setTextRecord(textRecord);
+                }
+            }
+        }
+
+        // Loop 3: find A and AAAA records, which reference the host name in the SRV record.
+        for (MdnsRecord record : records) {
+            if (record instanceof MdnsInetAddressRecord) {
+                MdnsInetAddressRecord inetRecord = (MdnsInetAddressRecord) record;
+                MdnsResponse response = findResponseWithHostName(responses, inetRecord.getName());
+                if (inetRecord.getInet4Address() != null && response != null) {
+                    response.setInet4AddressRecord(inetRecord);
+                } else if (inetRecord.getInet6Address() != null && response != null) {
+                    response.setInet6AddressRecord(inetRecord);
+                }
+            }
+        }
+
+        return SUCCESS;
+    }
+
+    public static class Clock {
+        public long elapsedRealtime() {
+            return SystemClock.elapsedRealtime();
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsResponseErrorCode.java b/service/mdns/com/android/server/connectivity/mdns/MdnsResponseErrorCode.java
new file mode 100644
index 0000000..fcf9058
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsResponseErrorCode.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+/**
+ * The list of error code for parsing mDNS response.
+ *
+ * @hide
+ */
+public class MdnsResponseErrorCode {
+    public static final int SUCCESS = 0;
+    public static final int ERROR_NOT_RESPONSE_MESSAGE = 1;
+    public static final int ERROR_NO_ANSWERS = 2;
+    public static final int ERROR_READING_RECORD_NAME = 3;
+    public static final int ERROR_READING_A_RDATA = 4;
+    public static final int ERROR_READING_AAAA_RDATA = 5;
+    public static final int ERROR_READING_PTR_RDATA = 6;
+    public static final int ERROR_SKIPPING_PTR_RDATA = 7;
+    public static final int ERROR_READING_SRV_RDATA = 8;
+    public static final int ERROR_SKIPPING_SRV_RDATA = 9;
+    public static final int ERROR_READING_TXT_RDATA = 10;
+    public static final int ERROR_SKIPPING_UNKNOWN_RECORD = 11;
+    public static final int ERROR_END_OF_FILE = 12;
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsSearchOptions.java b/service/mdns/com/android/server/connectivity/mdns/MdnsSearchOptions.java
new file mode 100644
index 0000000..6e90d2c
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsSearchOptions.java
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.text.TextUtils;
+import android.util.ArraySet;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * API configuration parameters for searching the mDNS service.
+ *
+ * <p>Use {@link MdnsSearchOptions.Builder} to create {@link MdnsSearchOptions}.
+ *
+ * @hide
+ */
+public class MdnsSearchOptions implements Parcelable {
+
+    /** @hide */
+    public static final Parcelable.Creator<MdnsSearchOptions> CREATOR =
+            new Parcelable.Creator<MdnsSearchOptions>() {
+                @Override
+                public MdnsSearchOptions createFromParcel(Parcel source) {
+                    return new MdnsSearchOptions(source.createStringArrayList(),
+                            source.readBoolean());
+                }
+
+                @Override
+                public MdnsSearchOptions[] newArray(int size) {
+                    return new MdnsSearchOptions[size];
+                }
+            };
+    private static MdnsSearchOptions defaultOptions;
+    private final List<String> subtypes;
+
+    private final boolean isPassiveMode;
+
+    /** Parcelable constructs for a {@link MdnsServiceInfo}. */
+    MdnsSearchOptions(List<String> subtypes, boolean isPassiveMode) {
+        this.subtypes = new ArrayList<>();
+        if (subtypes != null) {
+            this.subtypes.addAll(subtypes);
+        }
+        this.isPassiveMode = isPassiveMode;
+    }
+
+    /** Returns a {@link Builder} for {@link MdnsSearchOptions}. */
+    public static Builder newBuilder() {
+        return new Builder();
+    }
+
+    /** Returns a default search options. */
+    public static synchronized MdnsSearchOptions getDefaultOptions() {
+        if (defaultOptions == null) {
+            defaultOptions = newBuilder().build();
+        }
+        return defaultOptions;
+    }
+
+    /** @return the list of subtypes to search. */
+    public List<String> getSubtypes() {
+        return subtypes;
+    }
+
+    /**
+     * @return {@code true} if the passive mode is used. The passive mode scans less frequently in
+     * order to conserve battery and produce less network traffic.
+     */
+    public boolean isPassiveMode() {
+        return isPassiveMode;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeStringList(subtypes);
+        out.writeBoolean(isPassiveMode);
+    }
+
+    /** A builder to create {@link MdnsSearchOptions}. */
+    public static final class Builder {
+        private final Set<String> subtypes;
+        private boolean isPassiveMode = true;
+
+        private Builder() {
+            subtypes = new ArraySet<>();
+        }
+
+        /**
+         * Adds a subtype to search.
+         *
+         * @param subtype the subtype to add.
+         */
+        public Builder addSubtype(@NonNull String subtype) {
+            if (TextUtils.isEmpty(subtype)) {
+                throw new IllegalArgumentException("Empty subtype");
+            }
+            subtypes.add(subtype);
+            return this;
+        }
+
+        /**
+         * Adds a set of subtypes to search.
+         *
+         * @param subtypes The list of subtypes to add.
+         */
+        public Builder addSubtypes(@NonNull Collection<String> subtypes) {
+            this.subtypes.addAll(Objects.requireNonNull(subtypes));
+            return this;
+        }
+
+        /**
+         * Sets if the passive mode scan should be used. The passive mode scans less frequently in
+         * order
+         * to conserve battery and produce less network traffic.
+         *
+         * @param isPassiveMode If set to {@code true}, passive mode will be used. If set to {@code
+         *                      false}, active mode will be used.
+         */
+        public Builder setIsPassiveMode(boolean isPassiveMode) {
+            this.isPassiveMode = isPassiveMode;
+            return this;
+        }
+
+        /** Builds a {@link MdnsSearchOptions} with the arguments supplied to this builder. */
+        public MdnsSearchOptions build() {
+            return new MdnsSearchOptions(new ArrayList<>(subtypes), isPassiveMode);
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceBrowserListener.java b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceBrowserListener.java
new file mode 100644
index 0000000..53e58d1
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceBrowserListener.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+
+import java.util.List;
+
+/**
+ * Listener interface for mDNS service instance discovery events.
+ *
+ * @hide
+ */
+public interface MdnsServiceBrowserListener {
+
+    /**
+     * Called when an mDNS service instance is found.
+     *
+     * @param serviceInfo The found mDNS service instance.
+     */
+    void onServiceFound(@NonNull MdnsServiceInfo serviceInfo);
+
+    /**
+     * Called when an mDNS service instance is updated.
+     *
+     * @param serviceInfo The updated mDNS service instance.
+     */
+    void onServiceUpdated(@NonNull MdnsServiceInfo serviceInfo);
+
+    /**
+     * Called when an mDNS service instance is no longer valid and removed.
+     *
+     * @param serviceInstanceName The service instance name of the removed mDNS service.
+     */
+    void onServiceRemoved(@NonNull String serviceInstanceName);
+
+    /**
+     * Called when searching for mDNS service has stopped because of an error.
+     *
+     * TODO (changed when importing code): define error constants
+     *
+     * @param error The error code of the stop reason.
+     */
+    void onSearchStoppedWithError(int error);
+
+    /** Called when it failed to start an mDNS service discovery process. */
+    void onSearchFailedToStart();
+
+    /**
+     * Called when a mDNS service discovery query has been sent.
+     *
+     * @param subtypes      The list of subtypes in the discovery query.
+     * @param transactionId The transaction ID of the query.
+     */
+    void onDiscoveryQuerySent(@NonNull List<String> subtypes, int transactionId);
+
+    /**
+     * Called when an error has happened when parsing a received mDNS response packet.
+     *
+     * @param receivedPacketNumber The packet sequence number of the received packet.
+     * @param errorCode            The error code, defined in {@link MdnsResponseErrorCode}.
+     */
+    void onFailedToParseMdnsResponse(int receivedPacketNumber, int errorCode);
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java
new file mode 100644
index 0000000..2e4a4e5
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceInfo.java
@@ -0,0 +1,198 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.text.TextUtils;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * A class representing a discovered mDNS service instance.
+ *
+ * @hide
+ */
+public class MdnsServiceInfo implements Parcelable {
+
+    /** @hide */
+    public static final Parcelable.Creator<MdnsServiceInfo> CREATOR =
+            new Parcelable.Creator<MdnsServiceInfo>() {
+
+                @Override
+                public MdnsServiceInfo createFromParcel(Parcel source) {
+                    return new MdnsServiceInfo(
+                            source.readString(),
+                            source.createStringArray(),
+                            source.createStringArrayList(),
+                            source.createStringArray(),
+                            source.readInt(),
+                            source.readString(),
+                            source.readString(),
+                            source.createStringArrayList());
+                }
+
+                @Override
+                public MdnsServiceInfo[] newArray(int size) {
+                    return new MdnsServiceInfo[size];
+                }
+            };
+
+    private final String serviceInstanceName;
+    private final String[] serviceType;
+    private final List<String> subtypes;
+    private final String[] hostName;
+    private final int port;
+    private final String ipv4Address;
+    private final String ipv6Address;
+    private final Map<String, String> attributes = new HashMap<>();
+    List<String> textStrings;
+
+    /**
+     * Constructs a {@link MdnsServiceInfo} object with default values.
+     *
+     * @hide
+     */
+    public MdnsServiceInfo(
+            String serviceInstanceName,
+            String[] serviceType,
+            List<String> subtypes,
+            String[] hostName,
+            int port,
+            String ipv4Address,
+            String ipv6Address,
+            List<String> textStrings) {
+        this.serviceInstanceName = serviceInstanceName;
+        this.serviceType = serviceType;
+        this.subtypes = new ArrayList<>();
+        if (subtypes != null) {
+            this.subtypes.addAll(subtypes);
+        }
+        this.hostName = hostName;
+        this.port = port;
+        this.ipv4Address = ipv4Address;
+        this.ipv6Address = ipv6Address;
+        if (textStrings != null) {
+            for (String text : textStrings) {
+                int pos = text.indexOf('=');
+                if (pos < 1) {
+                    continue;
+                }
+                attributes.put(text.substring(0, pos).toLowerCase(Locale.ENGLISH),
+                        text.substring(++pos));
+            }
+        }
+    }
+
+    /** @return the name of this service instance. */
+    public String getServiceInstanceName() {
+        return serviceInstanceName;
+    }
+
+    /** @return the type of this service instance. */
+    public String[] getServiceType() {
+        return serviceType;
+    }
+
+    /** @return the list of subtypes supported by this service instance. */
+    public List<String> getSubtypes() {
+        return new ArrayList<>(subtypes);
+    }
+
+    /**
+     * @return {@code true} if this service instance supports any subtypes.
+     * @return {@code false} if this service instance does not support any subtypes.
+     */
+    public boolean hasSubtypes() {
+        return !subtypes.isEmpty();
+    }
+
+    /** @return the host name of this service instance. */
+    public String[] getHostName() {
+        return hostName;
+    }
+
+    /** @return the port number of this service instance. */
+    public int getPort() {
+        return port;
+    }
+
+    /** @return the IPV4 address of this service instance. */
+    public String getIpv4Address() {
+        return ipv4Address;
+    }
+
+    /** @return the IPV6 address of this service instance. */
+    public String getIpv6Address() {
+        return ipv6Address;
+    }
+
+    /**
+     * @return the attribute value for {@code key}.
+     * @return {@code null} if no attribute value exists for {@code key}.
+     */
+    public String getAttributeByKey(@NonNull String key) {
+        return attributes.get(key.toLowerCase(Locale.ENGLISH));
+    }
+
+    /** @return an immutable map of all attributes. */
+    public Map<String, String> getAttributes() {
+        return Collections.unmodifiableMap(attributes);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        if (textStrings == null) {
+            // Lazily initialize the parcelable field mTextStrings.
+            textStrings = new ArrayList<>(attributes.size());
+            for (Map.Entry<String, String> kv : attributes.entrySet()) {
+                textStrings.add(String.format(Locale.ROOT, "%s=%s", kv.getKey(), kv.getValue()));
+            }
+        }
+
+        out.writeString(serviceInstanceName);
+        out.writeStringArray(serviceType);
+        out.writeStringList(subtypes);
+        out.writeStringArray(hostName);
+        out.writeInt(port);
+        out.writeString(ipv4Address);
+        out.writeString(ipv6Address);
+        out.writeStringList(textStrings);
+    }
+
+    @Override
+    public String toString() {
+        return String.format(
+                Locale.ROOT,
+                "Name: %s, subtypes: %s, ip: %s, port: %d",
+                serviceInstanceName,
+                TextUtils.join(",", subtypes),
+                ipv4Address,
+                port);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceRecord.java b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceRecord.java
new file mode 100644
index 0000000..51de3b2
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceRecord.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Objects;
+
+/** An mDNS "SRV" record, which contains service information. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+@VisibleForTesting
+public class MdnsServiceRecord extends MdnsRecord {
+    public static final int PROTO_NONE = 0;
+    public static final int PROTO_TCP = 1;
+    public static final int PROTO_UDP = 2;
+    private static final String PROTO_TOKEN_TCP = "_tcp";
+    private static final String PROTO_TOKEN_UDP = "_udp";
+    private int servicePriority;
+    private int serviceWeight;
+    private int servicePort;
+    private String[] serviceHost;
+
+    public MdnsServiceRecord(String[] name, MdnsPacketReader reader) throws IOException {
+        super(name, TYPE_SRV, reader);
+    }
+
+    /** Returns the service's port number. */
+    public int getServicePort() {
+        return servicePort;
+    }
+
+    /** Returns the service's host name. */
+    public String[] getServiceHost() {
+        return serviceHost;
+    }
+
+    /** Returns the service's priority. */
+    public int getServicePriority() {
+        return servicePriority;
+    }
+
+    /** Returns the service's weight. */
+    public int getServiceWeight() {
+        return serviceWeight;
+    }
+
+    // Format of name is <instance-name>.<service-name>.<protocol>.<domain>
+
+    /** Returns the service's instance name, which uniquely identifies the service instance. */
+    public String getServiceInstanceName() {
+        if (name.length < 1) {
+            return null;
+        }
+        return name[0];
+    }
+
+    /** Returns the service's name. */
+    public String getServiceName() {
+        if (name.length < 2) {
+            return null;
+        }
+        return name[1];
+    }
+
+    /** Returns the service's protocol. */
+    public int getServiceProtocol() {
+        if (name.length < 3) {
+            return PROTO_NONE;
+        }
+
+        String protocol = name[2];
+        if (protocol.equals(PROTO_TOKEN_TCP)) {
+            return PROTO_TCP;
+        }
+        if (protocol.equals(PROTO_TOKEN_UDP)) {
+            return PROTO_UDP;
+        }
+        return PROTO_NONE;
+    }
+
+    @Override
+    protected void readData(MdnsPacketReader reader) throws IOException {
+        servicePriority = reader.readUInt16();
+        serviceWeight = reader.readUInt16();
+        servicePort = reader.readUInt16();
+        serviceHost = reader.readLabels();
+    }
+
+    @Override
+    protected void writeData(MdnsPacketWriter writer) throws IOException {
+        writer.writeUInt16(servicePriority);
+        writer.writeUInt16(serviceWeight);
+        writer.writeUInt16(servicePort);
+        writer.writeLabels(serviceHost);
+    }
+
+    @Override
+    public String toString() {
+        return String.format(
+                Locale.ROOT,
+                "SRV: %s:%d (prio=%d, weight=%d)",
+                labelsToString(serviceHost),
+                servicePort,
+                servicePriority,
+                serviceWeight);
+    }
+
+    @Override
+    public int hashCode() {
+        return (super.hashCode() * 31)
+                + Objects.hash(servicePriority, serviceWeight, Arrays.hashCode(serviceHost),
+                servicePort);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (!(other instanceof MdnsServiceRecord)) {
+            return false;
+        }
+        MdnsServiceRecord otherRecord = (MdnsServiceRecord) other;
+
+        return super.equals(other)
+                && (servicePriority == otherRecord.servicePriority)
+                && (serviceWeight == otherRecord.serviceWeight)
+                && Objects.equals(serviceHost, otherRecord.serviceHost)
+                && (servicePort == otherRecord.servicePort);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
new file mode 100644
index 0000000..c3a86e3
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
@@ -0,0 +1,370 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.text.TextUtils;
+import android.util.ArraySet;
+import android.util.Pair;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Instance of this class sends and receives mDNS packets of a given service type and invoke
+ * registered {@link MdnsServiceBrowserListener} instances.
+ */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class MdnsServiceTypeClient {
+
+    private static final int DEFAULT_MTU = 1500;
+    private static final MdnsLogger LOGGER = new MdnsLogger("MdnsServiceTypeClient");
+
+    private final String serviceType;
+    private final String[] serviceTypeLabels;
+    private final MdnsSocketClient socketClient;
+    private final ScheduledExecutorService executor;
+    private final Object lock = new Object();
+    private final Set<MdnsServiceBrowserListener> listeners = new ArraySet<>();
+    private final Map<String, MdnsResponse> instanceNameToResponse = new HashMap<>();
+
+    // The session ID increases when startSendAndReceive() is called where we schedule a
+    // QueryTask for
+    // new subtypes. It stays the same between packets for same subtypes.
+    private long currentSessionId = 0;
+
+    @GuardedBy("lock")
+    private Future<?> requestTaskFuture;
+
+    /**
+     * Constructor of {@link MdnsServiceTypeClient}.
+     *
+     * @param socketClient Sends and receives mDNS packet.
+     * @param executor     A {@link ScheduledExecutorService} used to schedule query tasks.
+     */
+    public MdnsServiceTypeClient(
+            @NonNull String serviceType,
+            @NonNull MdnsSocketClient socketClient,
+            @NonNull ScheduledExecutorService executor) {
+        this.serviceType = serviceType;
+        this.socketClient = socketClient;
+        this.executor = executor;
+        serviceTypeLabels = TextUtils.split(serviceType, "\\.");
+    }
+
+    private static MdnsServiceInfo buildMdnsServiceInfoFromResponse(
+            @NonNull MdnsResponse response, @NonNull String[] serviceTypeLabels) {
+        String[] hostName = response.getServiceRecord().getServiceHost();
+        int port = response.getServiceRecord().getServicePort();
+
+        String ipv4Address = null;
+        String ipv6Address = null;
+        if (response.hasInet4AddressRecord()) {
+            ipv4Address = response.getInet4AddressRecord().getInet4Address().getHostAddress();
+        }
+        if (response.hasInet6AddressRecord()) {
+            ipv6Address = response.getInet6AddressRecord().getInet6Address().getHostAddress();
+        }
+        // TODO: Throw an error message if response doesn't have Inet6 or Inet4 address.
+        return new MdnsServiceInfo(
+                response.getServiceInstanceName(),
+                serviceTypeLabels,
+                response.getSubtypes(),
+                hostName,
+                port,
+                ipv4Address,
+                ipv6Address,
+                response.getTextRecord().getStrings());
+    }
+
+    /**
+     * Registers {@code listener} for receiving discovery event of mDNS service instances, and
+     * starts
+     * (or continue) to send mDNS queries periodically.
+     *
+     * @param listener      The {@link MdnsServiceBrowserListener} to register.
+     * @param searchOptions {@link MdnsSearchOptions} contains the list of subtypes to discover.
+     */
+    public void startSendAndReceive(
+            @NonNull MdnsServiceBrowserListener listener,
+            @NonNull MdnsSearchOptions searchOptions) {
+        synchronized (lock) {
+            if (!listeners.contains(listener)) {
+                listeners.add(listener);
+                for (MdnsResponse existingResponse : instanceNameToResponse.values()) {
+                    if (existingResponse.isComplete()) {
+                        listener.onServiceFound(
+                                buildMdnsServiceInfoFromResponse(existingResponse,
+                                        serviceTypeLabels));
+                    }
+                }
+            }
+            // Cancel the next scheduled periodical task.
+            if (requestTaskFuture != null) {
+                requestTaskFuture.cancel(true);
+            }
+            // Keep tracking the ScheduledFuture for the task so we can cancel it if caller is not
+            // interested anymore.
+            requestTaskFuture =
+                    executor.submit(
+                            new QueryTask(
+                                    new QueryTaskConfig(
+                                            searchOptions.getSubtypes(),
+                                            searchOptions.isPassiveMode(),
+                                            ++currentSessionId)));
+        }
+    }
+
+    /**
+     * Unregisters {@code listener} from receiving discovery event of mDNS service instances.
+     *
+     * @param listener The {@link MdnsServiceBrowserListener} to unregister.
+     * @return {@code true} if no listener is registered with this client after unregistering {@code
+     * listener}. Otherwise returns {@code false}.
+     */
+    public boolean stopSendAndReceive(@NonNull MdnsServiceBrowserListener listener) {
+        synchronized (lock) {
+            listeners.remove(listener);
+            if (listeners.isEmpty() && requestTaskFuture != null) {
+                requestTaskFuture.cancel(true);
+                requestTaskFuture = null;
+            }
+            return listeners.isEmpty();
+        }
+    }
+
+    public String[] getServiceTypeLabels() {
+        return serviceTypeLabels;
+    }
+
+    public synchronized void processResponse(@NonNull MdnsResponse response) {
+        if (response.isGoodbye()) {
+            onGoodbyeReceived(response.getServiceInstanceName());
+        } else {
+            onResponseReceived(response);
+        }
+    }
+
+    public synchronized void onFailedToParseMdnsResponse(int receivedPacketNumber, int errorCode) {
+        for (MdnsServiceBrowserListener listener : listeners) {
+            listener.onFailedToParseMdnsResponse(receivedPacketNumber, errorCode);
+        }
+    }
+
+    private void onResponseReceived(@NonNull MdnsResponse response) {
+        MdnsResponse currentResponse;
+        currentResponse = instanceNameToResponse.get(response.getServiceInstanceName());
+
+        boolean newServiceFound = false;
+        boolean existingServiceChanged = false;
+        if (currentResponse == null) {
+            newServiceFound = true;
+            currentResponse = response;
+            instanceNameToResponse.put(response.getServiceInstanceName(), currentResponse);
+        } else if (currentResponse.mergeRecordsFrom(response)) {
+            existingServiceChanged = true;
+        }
+        if (!currentResponse.isComplete() || (!newServiceFound && !existingServiceChanged)) {
+            return;
+        }
+        MdnsServiceInfo serviceInfo =
+                buildMdnsServiceInfoFromResponse(currentResponse, serviceTypeLabels);
+
+        for (MdnsServiceBrowserListener listener : listeners) {
+            if (newServiceFound) {
+                listener.onServiceFound(serviceInfo);
+            } else {
+                listener.onServiceUpdated(serviceInfo);
+            }
+        }
+    }
+
+    private void onGoodbyeReceived(@NonNull String serviceInstanceName) {
+        instanceNameToResponse.remove(serviceInstanceName);
+        for (MdnsServiceBrowserListener listener : listeners) {
+            listener.onServiceRemoved(serviceInstanceName);
+        }
+    }
+
+    @VisibleForTesting
+    MdnsPacketWriter createMdnsPacketWriter() {
+        return new MdnsPacketWriter(DEFAULT_MTU);
+    }
+
+    // A configuration for the PeriodicalQueryTask that contains parameters to build a query packet.
+    // Call to getConfigForNextRun returns a config that can be used to build the next query task.
+    @VisibleForTesting
+    static class QueryTaskConfig {
+
+        private static final int INITIAL_TIME_BETWEEN_BURSTS_MS =
+                (int) MdnsConfigs.initialTimeBetweenBurstsMs();
+        private static final int TIME_BETWEEN_BURSTS_MS = (int) MdnsConfigs.timeBetweenBurstsMs();
+        private static final int QUERIES_PER_BURST = (int) MdnsConfigs.queriesPerBurst();
+        private static final int TIME_BETWEEN_QUERIES_IN_BURST_MS =
+                (int) MdnsConfigs.timeBetweenQueriesInBurstMs();
+        private static final int QUERIES_PER_BURST_PASSIVE_MODE =
+                (int) MdnsConfigs.queriesPerBurstPassive();
+        private static final int UNSIGNED_SHORT_MAX_VALUE = 65536;
+        // The following fields are used by QueryTask so we need to test them.
+        @VisibleForTesting
+        final List<String> subtypes;
+        private final boolean alwaysAskForUnicastResponse =
+                MdnsConfigs.alwaysAskForUnicastResponseInEachBurst();
+        private final boolean usePassiveMode;
+        private final long sessionId;
+        @VisibleForTesting
+        int transactionId;
+        @VisibleForTesting
+        boolean expectUnicastResponse;
+        private int queriesPerBurst;
+        private int timeBetweenBurstsInMs;
+        private int burstCounter;
+        private int timeToRunNextTaskInMs;
+        private boolean isFirstBurst;
+
+        QueryTaskConfig(@NonNull Collection<String> subtypes, boolean usePassiveMode,
+                long sessionId) {
+            this.usePassiveMode = usePassiveMode;
+            this.subtypes = new ArrayList<>(subtypes);
+            this.queriesPerBurst = QUERIES_PER_BURST;
+            this.burstCounter = 0;
+            this.transactionId = 1;
+            this.expectUnicastResponse = true;
+            this.isFirstBurst = true;
+            this.sessionId = sessionId;
+            // Config the scan frequency based on the scan mode.
+            if (this.usePassiveMode) {
+                // In passive scan mode, sends a single burst of QUERIES_PER_BURST queries, and then
+                // in each TIME_BETWEEN_BURSTS interval, sends QUERIES_PER_BURST_PASSIVE_MODE
+                // queries.
+                this.timeBetweenBurstsInMs = TIME_BETWEEN_BURSTS_MS;
+            } else {
+                // In active scan mode, sends a burst of QUERIES_PER_BURST queries,
+                // TIME_BETWEEN_QUERIES_IN_BURST_MS apart, then waits for the scan interval, and
+                // then repeats. The scan interval starts as INITIAL_TIME_BETWEEN_BURSTS_MS and
+                // doubles until it maxes out at TIME_BETWEEN_BURSTS_MS.
+                this.timeBetweenBurstsInMs = INITIAL_TIME_BETWEEN_BURSTS_MS;
+            }
+        }
+
+        QueryTaskConfig getConfigForNextRun() {
+            if (++transactionId > UNSIGNED_SHORT_MAX_VALUE) {
+                transactionId = 1;
+            }
+            // Only the first query expects uni-cast response.
+            expectUnicastResponse = false;
+            if (++burstCounter == queriesPerBurst) {
+                burstCounter = 0;
+
+                if (alwaysAskForUnicastResponse) {
+                    expectUnicastResponse = true;
+                }
+                // In passive scan mode, sends a single burst of QUERIES_PER_BURST queries, and
+                // then in each TIME_BETWEEN_BURSTS interval, sends QUERIES_PER_BURST_PASSIVE_MODE
+                // queries.
+                if (isFirstBurst) {
+                    isFirstBurst = false;
+                    if (usePassiveMode) {
+                        queriesPerBurst = QUERIES_PER_BURST_PASSIVE_MODE;
+                    }
+                }
+                // In active scan mode, sends a burst of QUERIES_PER_BURST queries,
+                // TIME_BETWEEN_QUERIES_IN_BURST_MS apart, then waits for the scan interval, and
+                // then repeats. The scan interval starts as INITIAL_TIME_BETWEEN_BURSTS_MS and
+                // doubles until it maxes out at TIME_BETWEEN_BURSTS_MS.
+                timeToRunNextTaskInMs = timeBetweenBurstsInMs;
+                if (timeBetweenBurstsInMs < TIME_BETWEEN_BURSTS_MS) {
+                    timeBetweenBurstsInMs = Math.min(timeBetweenBurstsInMs * 2,
+                            TIME_BETWEEN_BURSTS_MS);
+                }
+            } else {
+                timeToRunNextTaskInMs = TIME_BETWEEN_QUERIES_IN_BURST_MS;
+            }
+            return this;
+        }
+    }
+
+    // A FutureTask that enqueues a single query, and schedule a new FutureTask for the next task.
+    private class QueryTask implements Runnable {
+
+        private final QueryTaskConfig config;
+
+        QueryTask(@NonNull QueryTaskConfig config) {
+            this.config = config;
+        }
+
+        @Override
+        public void run() {
+            Pair<Integer, List<String>> result;
+            try {
+                result =
+                        new EnqueueMdnsQueryCallable(
+                                socketClient,
+                                createMdnsPacketWriter(),
+                                serviceType,
+                                config.subtypes,
+                                config.expectUnicastResponse,
+                                config.transactionId)
+                                .call();
+            } catch (Exception e) {
+                LOGGER.e(String.format("Failed to run EnqueueMdnsQueryCallable for subtype: %s",
+                        TextUtils.join(",", config.subtypes)), e);
+                result = null;
+            }
+            synchronized (lock) {
+                if (MdnsConfigs.useSessionIdToScheduleMdnsTask()) {
+                    // In case that the task is not canceled successfully, use session ID to check
+                    // if this task should continue to schedule more.
+                    if (config.sessionId != currentSessionId) {
+                        return;
+                    }
+                }
+
+                if (MdnsConfigs.shouldCancelScanTaskWhenFutureIsNull()) {
+                    if (requestTaskFuture == null) {
+                        // If requestTaskFuture is set to null, the task is cancelled. We can't use
+                        // isCancelled() here because this QueryTask is different from the future
+                        // that is returned from executor.schedule(). See b/71646910.
+                        return;
+                    }
+                }
+                if ((result != null)) {
+                    for (MdnsServiceBrowserListener listener : listeners) {
+                        listener.onDiscoveryQuerySent(result.second, result.first);
+                    }
+                }
+                QueryTaskConfig config = this.config.getConfigForNextRun();
+                requestTaskFuture =
+                        executor.schedule(
+                                new QueryTask(config), config.timeToRunNextTaskInMs,
+                                TimeUnit.MILLISECONDS);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsSocket.java b/service/mdns/com/android/server/connectivity/mdns/MdnsSocket.java
new file mode 100644
index 0000000..241a52a
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsSocket.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.util.List;
+
+/**
+ * {@link MdnsSocket} provides a similar interface to {@link MulticastSocket} and binds to all
+ * available multi-cast network interfaces.
+ *
+ * @see MulticastSocket for javadoc of each public method.
+ */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class MdnsSocket {
+    private static final InetSocketAddress MULTICAST_IPV4_ADDRESS =
+            new InetSocketAddress(MdnsConstants.getMdnsIPv4Address(), MdnsConstants.MDNS_PORT);
+    private static final InetSocketAddress MULTICAST_IPV6_ADDRESS =
+            new InetSocketAddress(MdnsConstants.getMdnsIPv6Address(), MdnsConstants.MDNS_PORT);
+    private static boolean isOnIPv6OnlyNetwork = false;
+    private final MulticastNetworkInterfaceProvider multicastNetworkInterfaceProvider;
+    private final MulticastSocket multicastSocket;
+
+    public MdnsSocket(
+            @NonNull MulticastNetworkInterfaceProvider multicastNetworkInterfaceProvider, int port)
+            throws IOException {
+        this.multicastNetworkInterfaceProvider = multicastNetworkInterfaceProvider;
+        this.multicastNetworkInterfaceProvider.startWatchingConnectivityChanges();
+        multicastSocket = createMulticastSocket(port);
+        // RFC Spec: https://tools.ietf.org/html/rfc6762
+        // Time to live is set 255, which is similar to the jMDNS implementation.
+        multicastSocket.setTimeToLive(255);
+
+        // TODO (changed when importing code): consider tagging the socket for data usage
+        isOnIPv6OnlyNetwork = false;
+    }
+
+    public void send(DatagramPacket packet) throws IOException {
+        List<NetworkInterfaceWrapper> networkInterfaces =
+                multicastNetworkInterfaceProvider.getMulticastNetworkInterfaces();
+        for (NetworkInterfaceWrapper networkInterface : networkInterfaces) {
+            multicastSocket.setNetworkInterface(networkInterface.getNetworkInterface());
+            multicastSocket.send(packet);
+        }
+    }
+
+    public void receive(DatagramPacket packet) throws IOException {
+        multicastSocket.receive(packet);
+    }
+
+    public void joinGroup() throws IOException {
+        List<NetworkInterfaceWrapper> networkInterfaces =
+                multicastNetworkInterfaceProvider.getMulticastNetworkInterfaces();
+        InetSocketAddress multicastAddress = MULTICAST_IPV4_ADDRESS;
+        if (multicastNetworkInterfaceProvider.isOnIpV6OnlyNetwork(networkInterfaces)) {
+            isOnIPv6OnlyNetwork = true;
+            multicastAddress = MULTICAST_IPV6_ADDRESS;
+        } else {
+            isOnIPv6OnlyNetwork = false;
+        }
+        for (NetworkInterfaceWrapper networkInterface : networkInterfaces) {
+            multicastSocket.joinGroup(multicastAddress, networkInterface.getNetworkInterface());
+        }
+    }
+
+    public void leaveGroup() throws IOException {
+        List<NetworkInterfaceWrapper> networkInterfaces =
+                multicastNetworkInterfaceProvider.getMulticastNetworkInterfaces();
+        InetSocketAddress multicastAddress = MULTICAST_IPV4_ADDRESS;
+        if (multicastNetworkInterfaceProvider.isOnIpV6OnlyNetwork(networkInterfaces)) {
+            multicastAddress = MULTICAST_IPV6_ADDRESS;
+        }
+        for (NetworkInterfaceWrapper networkInterface : networkInterfaces) {
+            multicastSocket.leaveGroup(multicastAddress, networkInterface.getNetworkInterface());
+        }
+    }
+
+    public void close() {
+        // This is a race with the use of the file descriptor (b/27403984).
+        multicastSocket.close();
+        multicastNetworkInterfaceProvider.stopWatchingConnectivityChanges();
+    }
+
+    @VisibleForTesting
+    MulticastSocket createMulticastSocket(int port) throws IOException {
+        return new MulticastSocket(port);
+    }
+
+    public boolean isOnIPv6OnlyNetwork() {
+        return isOnIPv6OnlyNetwork;
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsSocketClient.java b/service/mdns/com/android/server/connectivity/mdns/MdnsSocketClient.java
new file mode 100644
index 0000000..e689d6c
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsSocketClient.java
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.Manifest.permission;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.RequiresPermission;
+import android.content.Context;
+import android.net.wifi.WifiManager.MulticastLock;
+import android.os.SystemClock;
+import android.text.format.DateUtils;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * The {@link MdnsSocketClient} maintains separate threads to send and receive mDNS packets for all
+ * the requested service types.
+ *
+ * <p>See https://tools.ietf.org/html/rfc6763 (namely sections 4 and 5).
+ */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+public class MdnsSocketClient {
+
+    private static final String TAG = "MdnsClient";
+    // TODO: The following values are copied from cast module. We need to think about the
+    // better way to share those.
+    private static final String CAST_SENDER_LOG_SOURCE = "CAST_SENDER_SDK";
+    private static final String CAST_PREFS_NAME = "google_cast";
+    private static final String PREF_CAST_SENDER_ID = "PREF_CAST_SENDER_ID";
+    private static final MdnsLogger LOGGER = new MdnsLogger(TAG);
+    private static final String MULTICAST_TYPE = "multicast";
+    private static final String UNICAST_TYPE = "unicast";
+
+    private static final long SLEEP_TIME_FOR_SOCKET_THREAD_MS =
+            MdnsConfigs.sleepTimeForSocketThreadMs();
+    // A value of 0 leads to an infinite wait.
+    private static final long THREAD_JOIN_TIMEOUT_MS = DateUtils.SECOND_IN_MILLIS;
+    private static final int RECEIVER_BUFFER_SIZE = 2048;
+    @VisibleForTesting
+    final Queue<DatagramPacket> multicastPacketQueue = new ArrayDeque<>();
+    @VisibleForTesting
+    final Queue<DatagramPacket> unicastPacketQueue = new ArrayDeque<>();
+    private final Context context;
+    private final byte[] multicastReceiverBuffer = new byte[RECEIVER_BUFFER_SIZE];
+    private final byte[] unicastReceiverBuffer;
+    private final MdnsResponseDecoder responseDecoder;
+    private final MulticastLock multicastLock;
+    private final boolean useSeparateSocketForUnicast =
+            MdnsConfigs.useSeparateSocketToSendUnicastQuery();
+    private final boolean checkMulticastResponse = MdnsConfigs.checkMulticastResponse();
+    private final long checkMulticastResponseIntervalMs =
+            MdnsConfigs.checkMulticastResponseIntervalMs();
+    private final Object socketLock = new Object();
+    private final Object timerObject = new Object();
+    // If multicast response was received in the current session. The value is reset in the
+    // beginning of each session.
+    @VisibleForTesting
+    boolean receivedMulticastResponse;
+    // If unicast response was received in the current session. The value is reset in the beginning
+    // of each session.
+    @VisibleForTesting
+    boolean receivedUnicastResponse;
+    // If the phone is the bad state where it can't receive any multicast response.
+    @VisibleForTesting
+    AtomicBoolean cannotReceiveMulticastResponse = new AtomicBoolean(false);
+    @VisibleForTesting
+    volatile Thread sendThread;
+    @VisibleForTesting
+    Thread multicastReceiveThread;
+    @VisibleForTesting
+    Thread unicastReceiveThread;
+    private volatile boolean shouldStopSocketLoop;
+    private Callback callback;
+    private MdnsSocket multicastSocket;
+    private MdnsSocket unicastSocket;
+    private int receivedPacketNumber = 0;
+    private Timer logMdnsPacketTimer;
+    private AtomicInteger packetsCount;
+    private Timer checkMulticastResponseTimer;
+
+    public MdnsSocketClient(@NonNull Context context, @NonNull MulticastLock multicastLock) {
+        this.context = context;
+        this.multicastLock = multicastLock;
+        responseDecoder = new MdnsResponseDecoder(new MdnsResponseDecoder.Clock(), null);
+        if (useSeparateSocketForUnicast) {
+            unicastReceiverBuffer = new byte[RECEIVER_BUFFER_SIZE];
+        } else {
+            unicastReceiverBuffer = null;
+        }
+    }
+
+    public synchronized void setCallback(@Nullable Callback callback) {
+        this.callback = callback;
+    }
+
+    @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+    public synchronized void startDiscovery() throws IOException {
+        if (multicastSocket != null) {
+            LOGGER.w("Discovery is already in progress.");
+            return;
+        }
+
+        receivedMulticastResponse = false;
+        receivedUnicastResponse = false;
+        cannotReceiveMulticastResponse.set(false);
+
+        shouldStopSocketLoop = false;
+        try {
+            // TODO (changed when importing code): consider setting thread stats tag
+            multicastSocket = createMdnsSocket(MdnsConstants.MDNS_PORT);
+            multicastSocket.joinGroup();
+            if (useSeparateSocketForUnicast) {
+                // For unicast, use port 0 and the system will assign it with any available port.
+                unicastSocket = createMdnsSocket(0);
+            }
+            multicastLock.acquire();
+        } catch (IOException e) {
+            multicastLock.release();
+            if (multicastSocket != null) {
+                multicastSocket.close();
+                multicastSocket = null;
+            }
+            if (unicastSocket != null) {
+                unicastSocket.close();
+                unicastSocket = null;
+            }
+            throw e;
+        } finally {
+            // TODO (changed when importing code): consider resetting thread stats tag
+        }
+        createAndStartSendThread();
+        createAndStartReceiverThreads();
+    }
+
+    @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+    public void stopDiscovery() {
+        LOGGER.log("Stop discovery.");
+        if (multicastSocket == null && unicastSocket == null) {
+            return;
+        }
+
+        if (MdnsConfigs.clearMdnsPacketQueueAfterDiscoveryStops()) {
+            synchronized (multicastPacketQueue) {
+                multicastPacketQueue.clear();
+            }
+            synchronized (unicastPacketQueue) {
+                unicastPacketQueue.clear();
+            }
+        }
+
+        multicastLock.release();
+
+        shouldStopSocketLoop = true;
+        waitForSendThreadToStop();
+        waitForReceiverThreadsToStop();
+
+        synchronized (socketLock) {
+            multicastSocket = null;
+            unicastSocket = null;
+        }
+
+        synchronized (timerObject) {
+            if (checkMulticastResponseTimer != null) {
+                checkMulticastResponseTimer.cancel();
+                checkMulticastResponseTimer = null;
+            }
+        }
+    }
+
+    /** Sends a mDNS request packet that asks for multicast response. */
+    public void sendMulticastPacket(@NonNull DatagramPacket packet) {
+        sendMdnsPacket(packet, multicastPacketQueue);
+    }
+
+    /** Sends a mDNS request packet that asks for unicast response. */
+    public void sendUnicastPacket(DatagramPacket packet) {
+        if (useSeparateSocketForUnicast) {
+            sendMdnsPacket(packet, unicastPacketQueue);
+        } else {
+            sendMdnsPacket(packet, multicastPacketQueue);
+        }
+    }
+
+    private void sendMdnsPacket(DatagramPacket packet, Queue<DatagramPacket> packetQueueToUse) {
+        if (shouldStopSocketLoop && !MdnsConfigs.allowAddMdnsPacketAfterDiscoveryStops()) {
+            LOGGER.w("sendMdnsPacket() is called after discovery already stopped");
+            return;
+        }
+        synchronized (packetQueueToUse) {
+            while (packetQueueToUse.size() >= MdnsConfigs.mdnsPacketQueueMaxSize()) {
+                packetQueueToUse.remove();
+            }
+            packetQueueToUse.add(packet);
+        }
+        triggerSendThread();
+    }
+
+    private void createAndStartSendThread() {
+        if (sendThread != null) {
+            LOGGER.w("A socket thread already exists.");
+            return;
+        }
+        sendThread = new Thread(this::sendThreadMain);
+        sendThread.setName("mdns-send");
+        sendThread.start();
+    }
+
+    private void createAndStartReceiverThreads() {
+        if (multicastReceiveThread != null) {
+            LOGGER.w("A multicast receiver thread already exists.");
+            return;
+        }
+        multicastReceiveThread =
+                new Thread(() -> receiveThreadMain(multicastReceiverBuffer, multicastSocket));
+        multicastReceiveThread.setName("mdns-multicast-receive");
+        multicastReceiveThread.start();
+
+        if (useSeparateSocketForUnicast) {
+            unicastReceiveThread =
+                    new Thread(() -> receiveThreadMain(unicastReceiverBuffer, unicastSocket));
+            unicastReceiveThread.setName("mdns-unicast-receive");
+            unicastReceiveThread.start();
+        }
+    }
+
+    private void triggerSendThread() {
+        LOGGER.log("Trigger send thread.");
+        Thread sendThread = this.sendThread;
+        if (sendThread != null) {
+            sendThread.interrupt();
+        } else {
+            LOGGER.w("Socket thread is null");
+        }
+    }
+
+    private void waitForReceiverThreadsToStop() {
+        if (multicastReceiveThread != null) {
+            waitForThread(multicastReceiveThread);
+            multicastReceiveThread = null;
+        }
+
+        if (unicastReceiveThread != null) {
+            waitForThread(unicastReceiveThread);
+            unicastReceiveThread = null;
+        }
+    }
+
+    private void waitForSendThreadToStop() {
+        LOGGER.log("wait For Send Thread To Stop");
+        if (sendThread == null) {
+            LOGGER.w("socket thread is already dead.");
+            return;
+        }
+        waitForThread(sendThread);
+        sendThread = null;
+    }
+
+    private void waitForThread(Thread thread) {
+        long startMs = SystemClock.elapsedRealtime();
+        long waitMs = THREAD_JOIN_TIMEOUT_MS;
+        while (thread.isAlive() && (waitMs > 0)) {
+            try {
+                thread.interrupt();
+                thread.join(waitMs);
+                if (thread.isAlive()) {
+                    LOGGER.w("Failed to join thread: " + thread);
+                }
+                break;
+            } catch (InterruptedException e) {
+                // Compute remaining time after at least a single join call, in case the clock
+                // resolution is poor.
+                waitMs = THREAD_JOIN_TIMEOUT_MS - (SystemClock.elapsedRealtime() - startMs);
+            }
+        }
+    }
+
+    private void sendThreadMain() {
+        List<DatagramPacket> multicastPacketsToSend = new ArrayList<>();
+        List<DatagramPacket> unicastPacketsToSend = new ArrayList<>();
+        boolean shouldThreadSleep;
+        try {
+            while (!shouldStopSocketLoop) {
+                try {
+                    // Make a local copy of all packets, and clear the queue.
+                    // Send packets that ask for multicast response.
+                    multicastPacketsToSend.clear();
+                    synchronized (multicastPacketQueue) {
+                        multicastPacketsToSend.addAll(multicastPacketQueue);
+                        multicastPacketQueue.clear();
+                    }
+
+                    // Send packets that ask for unicast response.
+                    if (useSeparateSocketForUnicast) {
+                        unicastPacketsToSend.clear();
+                        synchronized (unicastPacketQueue) {
+                            unicastPacketsToSend.addAll(unicastPacketQueue);
+                            unicastPacketQueue.clear();
+                        }
+                    }
+
+                    // Send all the packets.
+                    sendPackets(multicastPacketsToSend, multicastSocket);
+                    sendPackets(unicastPacketsToSend, unicastSocket);
+
+                    // Sleep ONLY if no more packets have been added to the queue, while packets
+                    // were being sent.
+                    synchronized (multicastPacketQueue) {
+                        synchronized (unicastPacketQueue) {
+                            shouldThreadSleep =
+                                    multicastPacketQueue.isEmpty() && unicastPacketQueue.isEmpty();
+                        }
+                    }
+                    if (shouldThreadSleep) {
+                        Thread.sleep(SLEEP_TIME_FOR_SOCKET_THREAD_MS);
+                    }
+                } catch (InterruptedException e) {
+                    // Don't log the interruption as it's expected.
+                }
+            }
+        } finally {
+            LOGGER.log("Send thread stopped.");
+            try {
+                multicastSocket.leaveGroup();
+            } catch (Exception t) {
+                LOGGER.e("Failed to leave the group.", t);
+            }
+
+            // Close the socket first. This is the only way to interrupt a blocking receive.
+            try {
+                // This is a race with the use of the file descriptor (b/27403984).
+                multicastSocket.close();
+                if (unicastSocket != null) {
+                    unicastSocket.close();
+                }
+            } catch (Exception t) {
+                LOGGER.e("Failed to close the mdns socket.", t);
+            }
+        }
+    }
+
+    private void receiveThreadMain(byte[] receiverBuffer, MdnsSocket socket) {
+        DatagramPacket packet = new DatagramPacket(receiverBuffer, receiverBuffer.length);
+
+        while (!shouldStopSocketLoop) {
+            try {
+                // This is a race with the use of the file descriptor (b/27403984).
+                synchronized (socketLock) {
+                    // This checks is to make sure the socket was not set to null.
+                    if (socket != null && (socket == multicastSocket || socket == unicastSocket)) {
+                        socket.receive(packet);
+                    }
+                }
+
+                if (!shouldStopSocketLoop) {
+                    String responseType = socket == multicastSocket ? MULTICAST_TYPE : UNICAST_TYPE;
+                    processResponsePacket(packet, responseType);
+                }
+            } catch (IOException e) {
+                if (!shouldStopSocketLoop) {
+                    LOGGER.e("Failed to receive mDNS packets.", e);
+                }
+            }
+        }
+        LOGGER.log("Receive thread stopped.");
+    }
+
+    private int processResponsePacket(@NonNull DatagramPacket packet, String responseType)
+            throws IOException {
+        int packetNumber = ++receivedPacketNumber;
+
+        List<MdnsResponse> responses = new LinkedList<>();
+        int errorCode = responseDecoder.decode(packet, responses);
+        if (errorCode == MdnsResponseDecoder.SUCCESS) {
+            if (responseType.equals(MULTICAST_TYPE)) {
+                receivedMulticastResponse = true;
+                if (cannotReceiveMulticastResponse.getAndSet(false)) {
+                    // If we are already in the bad state, receiving a multicast response means
+                    // we are recovered.
+                    LOGGER.e(
+                            "Recovered from the state where the phone can't receive any multicast"
+                                    + " response");
+                }
+            } else {
+                receivedUnicastResponse = true;
+            }
+            for (MdnsResponse response : responses) {
+                String serviceInstanceName = response.getServiceInstanceName();
+                LOGGER.log("mDNS %s response received: %s", responseType, serviceInstanceName);
+                if (callback != null) {
+                    callback.onResponseReceived(response);
+                }
+            }
+        } else if (errorCode != MdnsResponseErrorCode.ERROR_NOT_RESPONSE_MESSAGE) {
+            LOGGER.w(String.format("Error while decoding %s packet (%d): %d",
+                    responseType, packetNumber, errorCode));
+            if (callback != null) {
+                callback.onFailedToParseMdnsResponse(packetNumber, errorCode);
+            }
+        }
+        return errorCode;
+    }
+
+    @VisibleForTesting
+    MdnsSocket createMdnsSocket(int port) throws IOException {
+        return new MdnsSocket(new MulticastNetworkInterfaceProvider(context), port);
+    }
+
+    private void sendPackets(List<DatagramPacket> packets, MdnsSocket socket) {
+        String requestType = socket == multicastSocket ? "multicast" : "unicast";
+        for (DatagramPacket packet : packets) {
+            if (shouldStopSocketLoop) {
+                break;
+            }
+            try {
+                LOGGER.log("Sending a %s mDNS packet...", requestType);
+                socket.send(packet);
+
+                // Start the timer task to monitor the response.
+                synchronized (timerObject) {
+                    if (socket == multicastSocket) {
+                        if (cannotReceiveMulticastResponse.get()) {
+                            // Don't schedule the timer task if we are already in the bad state.
+                            return;
+                        }
+                        if (checkMulticastResponseTimer != null) {
+                            // Don't schedule the timer task if it's already scheduled.
+                            return;
+                        }
+                        if (checkMulticastResponse && useSeparateSocketForUnicast) {
+                            // Only when useSeparateSocketForUnicast is true, we can tell if we
+                            // received a multicast or unicast response.
+                            checkMulticastResponseTimer = new Timer();
+                            checkMulticastResponseTimer.schedule(
+                                    new TimerTask() {
+                                        @Override
+                                        public void run() {
+                                            synchronized (timerObject) {
+                                                if (checkMulticastResponseTimer == null) {
+                                                    // Discovery already stopped.
+                                                    return;
+                                                }
+                                                if ((!receivedMulticastResponse)
+                                                        && receivedUnicastResponse) {
+                                                    LOGGER.e(String.format(
+                                                            "Haven't received multicast response"
+                                                                    + " in the last %d ms.",
+                                                            checkMulticastResponseIntervalMs));
+                                                    cannotReceiveMulticastResponse.set(true);
+                                                }
+                                                checkMulticastResponseTimer = null;
+                                            }
+                                        }
+                                    },
+                                    checkMulticastResponseIntervalMs);
+                        }
+                    }
+                }
+            } catch (IOException e) {
+                LOGGER.e(String.format("Failed to send a %s mDNS packet.", requestType), e);
+            }
+        }
+        packets.clear();
+    }
+
+    public boolean isOnIPv6OnlyNetwork() {
+        return multicastSocket.isOnIPv6OnlyNetwork();
+    }
+
+    /** Callback for {@link MdnsSocketClient}. */
+    public interface Callback {
+        void onResponseReceived(@NonNull MdnsResponse response);
+
+        void onFailedToParseMdnsResponse(int receivedPacketNumber, int errorCode);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MdnsTextRecord.java b/service/mdns/com/android/server/connectivity/mdns/MdnsTextRecord.java
new file mode 100644
index 0000000..a5b5595
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MdnsTextRecord.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+/** An mDNS "TXT" record, which contains a list of text strings. */
+// TODO(b/177655645): Resolve nullness suppression.
+@SuppressWarnings("nullness")
+@VisibleForTesting
+public class MdnsTextRecord extends MdnsRecord {
+    private List<String> strings;
+
+    public MdnsTextRecord(String[] name, MdnsPacketReader reader) throws IOException {
+        super(name, TYPE_TXT, reader);
+    }
+
+    /** Returns the list of strings. */
+    public List<String> getStrings() {
+        return Collections.unmodifiableList(strings);
+    }
+
+    @Override
+    protected void readData(MdnsPacketReader reader) throws IOException {
+        strings = new ArrayList<>();
+        while (reader.getRemaining() > 0) {
+            strings.add(reader.readString());
+        }
+    }
+
+    @Override
+    protected void writeData(MdnsPacketWriter writer) throws IOException {
+        if (strings != null) {
+            for (String string : strings) {
+                writer.writeString(string);
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("TXT: {");
+        if (strings != null) {
+            for (String string : strings) {
+                sb.append(' ').append(string);
+            }
+        }
+        sb.append("}");
+
+        return sb.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return (super.hashCode() * 31) + Objects.hash(strings);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        if (!(other instanceof MdnsTextRecord)) {
+            return false;
+        }
+
+        return super.equals(other) && Objects.equals(strings, ((MdnsTextRecord) other).strings);
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProvider.java b/service/mdns/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProvider.java
new file mode 100644
index 0000000..e0d8fa6
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProvider.java
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.connectivity.mdns.util.MdnsLogger;
+
+import java.io.IOException;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InterfaceAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+
+/**
+ * This class is used by the {@link MdnsSocket} to monitor the list of {@link NetworkInterface}
+ * instances that are currently available for multi-cast messaging.
+ */
+public class MulticastNetworkInterfaceProvider {
+
+    private static final String TAG = "MdnsNIProvider";
+    private static final MdnsLogger LOGGER = new MdnsLogger(TAG);
+    private static final boolean PREFER_IPV6 = MdnsConfigs.preferIpv6();
+
+    private final List<NetworkInterfaceWrapper> multicastNetworkInterfaces = new ArrayList<>();
+    // Only modifiable from tests.
+    @VisibleForTesting
+    ConnectivityMonitor connectivityMonitor;
+    private volatile boolean connectivityChanged = true;
+
+    @SuppressWarnings("nullness:methodref.receiver.bound")
+    public MulticastNetworkInterfaceProvider(@NonNull Context context) {
+        // IMPORT CHANGED
+        this.connectivityMonitor = new ConnectivityMonitorWithConnectivityManager(
+                context, this::onConnectivityChanged);
+    }
+
+    private void onConnectivityChanged() {
+        connectivityChanged = true;
+    }
+
+    /**
+     * Starts monitoring changes of connectivity of this device, which may indicate that the list of
+     * network interfaces available for multi-cast messaging has changed.
+     */
+    public void startWatchingConnectivityChanges() {
+        connectivityMonitor.startWatchingConnectivityChanges();
+    }
+
+    /** Stops monitoring changes of connectivity. */
+    public void stopWatchingConnectivityChanges() {
+        connectivityMonitor.stopWatchingConnectivityChanges();
+    }
+
+    /**
+     * Returns the list of {@link NetworkInterfaceWrapper} instances available for multi-cast
+     * messaging.
+     */
+    public synchronized List<NetworkInterfaceWrapper> getMulticastNetworkInterfaces() {
+        if (connectivityChanged) {
+            connectivityChanged = false;
+            updateMulticastNetworkInterfaces();
+            if (multicastNetworkInterfaces.isEmpty()) {
+                LOGGER.log("No network interface available for mDNS scanning.");
+            }
+        }
+        return new ArrayList<>(multicastNetworkInterfaces);
+    }
+
+    private void updateMulticastNetworkInterfaces() {
+        multicastNetworkInterfaces.clear();
+        List<NetworkInterfaceWrapper> networkInterfaceWrappers = getNetworkInterfaces();
+        for (NetworkInterfaceWrapper interfaceWrapper : networkInterfaceWrappers) {
+            if (canScanOnInterface(interfaceWrapper)) {
+                multicastNetworkInterfaces.add(interfaceWrapper);
+            }
+        }
+    }
+
+    public boolean isOnIpV6OnlyNetwork(List<NetworkInterfaceWrapper> networkInterfaces) {
+        if (networkInterfaces.isEmpty()) {
+            return false;
+        }
+
+        // TODO(b/79866499): Remove this when the bug is resolved.
+        if (PREFER_IPV6) {
+            return true;
+        }
+        boolean hasAtleastOneIPv6Address = false;
+        for (NetworkInterfaceWrapper interfaceWrapper : networkInterfaces) {
+            for (InterfaceAddress ifAddr : interfaceWrapper.getInterfaceAddresses()) {
+                if (!(ifAddr.getAddress() instanceof Inet6Address)) {
+                    return false;
+                } else {
+                    hasAtleastOneIPv6Address = true;
+                }
+            }
+        }
+        return hasAtleastOneIPv6Address;
+    }
+
+    @VisibleForTesting
+    List<NetworkInterfaceWrapper> getNetworkInterfaces() {
+        List<NetworkInterfaceWrapper> networkInterfaceWrappers = new ArrayList<>();
+        try {
+            Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
+            if (interfaces != null) {
+                while (interfaces.hasMoreElements()) {
+                    networkInterfaceWrappers.add(
+                            new NetworkInterfaceWrapper(interfaces.nextElement()));
+                }
+            }
+        } catch (SocketException e) {
+            LOGGER.e("Failed to get network interfaces.", e);
+        } catch (NullPointerException e) {
+            // Android R has a bug that could lead to a NPE. See b/159277702.
+            LOGGER.e("Failed to call getNetworkInterfaces API", e);
+        }
+
+        return networkInterfaceWrappers;
+    }
+
+    private boolean canScanOnInterface(@Nullable NetworkInterfaceWrapper networkInterface) {
+        try {
+            if ((networkInterface == null)
+                    || networkInterface.isLoopback()
+                    || networkInterface.isPointToPoint()
+                    || networkInterface.isVirtual()
+                    || !networkInterface.isUp()
+                    || !networkInterface.supportsMulticast()) {
+                return false;
+            }
+            return hasInet4Address(networkInterface) || hasInet6Address(networkInterface);
+        } catch (IOException e) {
+            LOGGER.e(String.format("Failed to check interface %s.",
+                    networkInterface.getNetworkInterface().getDisplayName()), e);
+        }
+
+        return false;
+    }
+
+    private boolean hasInet4Address(@NonNull NetworkInterfaceWrapper networkInterface) {
+        for (InterfaceAddress ifAddr : networkInterface.getInterfaceAddresses()) {
+            if (ifAddr.getAddress() instanceof Inet4Address) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean hasInet6Address(@NonNull NetworkInterfaceWrapper networkInterface) {
+        for (InterfaceAddress ifAddr : networkInterface.getInterfaceAddresses()) {
+            if (ifAddr.getAddress() instanceof Inet6Address) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/NetworkInterfaceWrapper.java b/service/mdns/com/android/server/connectivity/mdns/NetworkInterfaceWrapper.java
new file mode 100644
index 0000000..0ecae48
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/NetworkInterfaceWrapper.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns;
+
+import java.net.InterfaceAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.List;
+
+/** A wrapper class of {@link NetworkInterface} to be mocked in unit tests. */
+public class NetworkInterfaceWrapper {
+    private final NetworkInterface networkInterface;
+
+    public NetworkInterfaceWrapper(NetworkInterface networkInterface) {
+        this.networkInterface = networkInterface;
+    }
+
+    public NetworkInterface getNetworkInterface() {
+        return networkInterface;
+    }
+
+    public boolean isUp() throws SocketException {
+        return networkInterface.isUp();
+    }
+
+    public boolean isLoopback() throws SocketException {
+        return networkInterface.isLoopback();
+    }
+
+    public boolean isPointToPoint() throws SocketException {
+        return networkInterface.isPointToPoint();
+    }
+
+    public boolean isVirtual() {
+        return networkInterface.isVirtual();
+    }
+
+    public boolean supportsMulticast() throws SocketException {
+        return networkInterface.supportsMulticast();
+    }
+
+    public List<InterfaceAddress> getInterfaceAddresses() {
+        return networkInterface.getInterfaceAddresses();
+    }
+
+    @Override
+    public String toString() {
+        return networkInterface.toString();
+    }
+}
\ No newline at end of file
diff --git a/service/mdns/com/android/server/connectivity/mdns/util/MdnsLogger.java b/service/mdns/com/android/server/connectivity/mdns/util/MdnsLogger.java
new file mode 100644
index 0000000..431f1fd
--- /dev/null
+++ b/service/mdns/com/android/server/connectivity/mdns/util/MdnsLogger.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.connectivity.mdns.util;
+
+import android.text.TextUtils;
+
+import com.android.net.module.util.SharedLog;
+
+/**
+ * The logger used in mDNS.
+ */
+public class MdnsLogger {
+    // Make this logger public for other level logging than dogfood.
+    public final SharedLog mLog;
+
+    /**
+     * Constructs a new {@link MdnsLogger} with the given logging tag.
+     *
+     * @param tag The log tag that will be used by this logger
+     */
+    public MdnsLogger(String tag) {
+        mLog = new SharedLog(tag);
+    }
+
+    public void log(String message) {
+        mLog.log(message);
+    }
+
+    public void log(String message, Object... args) {
+        mLog.log(message + " ; " + TextUtils.join(" ; ", args));
+    }
+
+    public void d(String message) {
+        mLog.log(message);
+    }
+
+    public void e(String message) {
+        mLog.e(message);
+    }
+
+    public void e(String message, Throwable e) {
+        mLog.e(message, e);
+    }
+
+    public void w(String message) {
+        mLog.w(message);
+    }
+}
diff --git a/service/native/Android.bp b/service/native/Android.bp
index cb26bc3..697fcbd 100644
--- a/service/native/Android.bp
+++ b/service/native/Android.bp
@@ -52,7 +52,8 @@
 
 cc_test {
     name: "traffic_controller_unit_test",
-    test_suites: ["general-tests"],
+    test_suites: ["general-tests", "mts-tethering"],
+    test_config_template: ":net_native_test_config_template",
     require_root: true,
     local_include_dirs: ["include"],
     header_libs: [
@@ -71,4 +72,13 @@
         "libnetd_updatable",
         "netd_aidl_interface-lateststable-ndk",
     ],
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            suffix: "32",
+        },
+        lib64: {
+            suffix: "64",
+        },
+    },
 }
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index 4923b00..9331548 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -56,7 +56,6 @@
 using bpf::BpfMap;
 using bpf::synchronizeKernelRCU;
 using netdutils::DumpWriter;
-using netdutils::getIfaceList;
 using netdutils::NetlinkListener;
 using netdutils::NetlinkListenerInterface;
 using netdutils::ScopedIndent;
@@ -111,14 +110,6 @@
     return matchType;
 }
 
-bool TrafficController::hasUpdateDeviceStatsPermission(uid_t uid) {
-    // This implementation is the same logic as method ActivityManager#checkComponentPermission.
-    // It implies that the calling uid can never be the same as PER_USER_RANGE.
-    uint32_t appId = uid % PER_USER_RANGE;
-    return ((appId == AID_ROOT) || (appId == AID_SYSTEM) ||
-            mPrivilegedUser.find(appId) != mPrivilegedUser.end());
-}
-
 const std::string UidPermissionTypeToString(int permission) {
     if (permission == INetd::PERMISSION_NONE) {
         return "PERMISSION_NONE";
@@ -190,6 +181,7 @@
     RETURN_IF_NOT_OK(mUidOwnerMap.init(UID_OWNER_MAP_PATH));
     RETURN_IF_NOT_OK(mUidOwnerMap.clear());
     RETURN_IF_NOT_OK(mUidPermissionMap.init(UID_PERMISSION_MAP_PATH));
+    ALOGI("%s successfully", __func__);
 
     return netdutils::status::ok;
 }
@@ -197,16 +189,6 @@
 Status TrafficController::start() {
     RETURN_IF_NOT_OK(initMaps());
 
-    // Fetch the list of currently-existing interfaces. At this point NetlinkHandler is
-    // already running, so it will call addInterface() when any new interface appears.
-    // TODO: Clean-up addInterface() after interface monitoring is in
-    // NetworkStatsService.
-    std::map<std::string, uint32_t> ifacePairs;
-    ASSIGN_OR_RETURN(ifacePairs, getIfaceList());
-    for (const auto& ifacePair:ifacePairs) {
-        addInterface(ifacePair.first.c_str(), ifacePair.second);
-    }
-
     auto result = makeSkDestroyListener();
     if (!isOk(result)) {
         ALOGE("Unable to create SkDestroyListener: %s", toString(result).c_str());
@@ -244,22 +226,6 @@
     return netdutils::status::ok;
 }
 
-int TrafficController::addInterface(const char* name, uint32_t ifaceIndex) {
-    IfaceValue iface;
-    if (ifaceIndex == 0) {
-        ALOGE("Unknown interface %s(%d)", name, ifaceIndex);
-        return -1;
-    }
-
-    strlcpy(iface.name, name, sizeof(IfaceValue));
-    Status res = mIfaceIndexNameMap.writeValue(ifaceIndex, iface, BPF_ANY);
-    if (!isOk(res)) {
-        ALOGE("Failed to add iface %s(%d): %s", name, ifaceIndex, strerror(res.code()));
-        return -res.code();
-    }
-    return 0;
-}
-
 Status TrafficController::updateOwnerMapEntry(UidOwnerMatchType match, uid_t uid, FirewallRule rule,
                                               FirewallType type) {
     std::lock_guard guard(mMutex);
@@ -339,8 +305,6 @@
             return ALLOWLIST;
         case LOW_POWER_STANDBY:
             return ALLOWLIST;
-        case LOCKDOWN:
-            return DENYLIST;
         case OEM_DENY_1:
             return DENYLIST;
         case OEM_DENY_2:
@@ -372,9 +336,6 @@
         case LOW_POWER_STANDBY:
             res = updateOwnerMapEntry(LOW_POWER_STANDBY_MATCH, uid, rule, type);
             break;
-        case LOCKDOWN:
-            res = updateOwnerMapEntry(LOCKDOWN_VPN_MATCH, uid, rule, type);
-            break;
         case OEM_DENY_1:
             res = updateOwnerMapEntry(OEM_DENY_1_MATCH, uid, rule, type);
             break;
@@ -446,6 +407,18 @@
     return netdutils::status::ok;
 }
 
+Status TrafficController::updateUidLockdownRule(const uid_t uid, const bool add) {
+    std::lock_guard guard(mMutex);
+
+    netdutils::Status result = add ? addRule(uid, LOCKDOWN_VPN_MATCH)
+                               : removeRule(uid, LOCKDOWN_VPN_MATCH);
+    if (!isOk(result)) {
+        ALOGW("%s Lockdown rule failed(%d): uid=%d",
+              (add ? "add": "remove"), result.code(), uid);
+    }
+    return result;
+}
+
 int TrafficController::replaceUidOwnerMap(const std::string& name, bool isAllowlist __unused,
                                           const std::vector<int32_t>& uids) {
     // FirewallRule rule = isAllowlist ? ALLOW : DENY;
@@ -478,55 +451,6 @@
     return 0;
 }
 
-int TrafficController::toggleUidOwnerMap(ChildChain chain, bool enable) {
-    std::lock_guard guard(mMutex);
-    uint32_t key = UID_RULES_CONFIGURATION_KEY;
-    auto oldConfigure = mConfigurationMap.readValue(key);
-    if (!oldConfigure.ok()) {
-        ALOGE("Cannot read the old configuration from map: %s",
-              oldConfigure.error().message().c_str());
-        return -oldConfigure.error().code();
-    }
-    Status res;
-    BpfConfig newConfiguration;
-    uint32_t match;
-    switch (chain) {
-        case DOZABLE:
-            match = DOZABLE_MATCH;
-            break;
-        case STANDBY:
-            match = STANDBY_MATCH;
-            break;
-        case POWERSAVE:
-            match = POWERSAVE_MATCH;
-            break;
-        case RESTRICTED:
-            match = RESTRICTED_MATCH;
-            break;
-        case LOW_POWER_STANDBY:
-            match = LOW_POWER_STANDBY_MATCH;
-            break;
-        case OEM_DENY_1:
-            match = OEM_DENY_1_MATCH;
-            break;
-        case OEM_DENY_2:
-            match = OEM_DENY_2_MATCH;
-            break;
-        case OEM_DENY_3:
-            match = OEM_DENY_3_MATCH;
-            break;
-        default:
-            return -EINVAL;
-    }
-    newConfiguration =
-            enable ? (oldConfigure.value() | match) : (oldConfigure.value() & (~match));
-    res = mConfigurationMap.writeValue(key, newConfiguration, BPF_EXIST);
-    if (!isOk(res)) {
-        ALOGE("Failed to toggleUidOwnerMap(%d): %s", chain, res.msg().c_str());
-    }
-    return -res.code();
-}
-
 Status TrafficController::swapActiveStatsMap() {
     std::lock_guard guard(mMutex);
 
diff --git a/service/native/TrafficControllerTest.cpp b/service/native/TrafficControllerTest.cpp
index 9e53f11..7730c13 100644
--- a/service/native/TrafficControllerTest.cpp
+++ b/service/native/TrafficControllerTest.cpp
@@ -30,13 +30,15 @@
 
 #include <gtest/gtest.h>
 
+#include <android-base/file.h>
+#include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <binder/Status.h>
 
 #include <netdutils/MockSyscalls.h>
 
-#define TEST_BPF_MAP
+#define BPF_MAP_MAKE_VISIBLE_FOR_TESTING
 #include "TrafficController.h"
 #include "bpf/BpfUtils.h"
 #include "NetdUpdatablePublic.h"
@@ -49,6 +51,7 @@
 using android::netdutils::Status;
 using base::Result;
 using netdutils::isOk;
+using netdutils::statusFromErrno;
 
 constexpr int TEST_MAP_SIZE = 10;
 constexpr uid_t TEST_UID = 10086;
@@ -56,8 +59,16 @@
 constexpr uid_t TEST_UID3 = 98765;
 constexpr uint32_t TEST_TAG = 42;
 constexpr uint32_t TEST_COUNTERSET = 1;
+constexpr int TEST_COOKIE = 1;
+constexpr char TEST_IFNAME[] = "test0";
+constexpr int TEST_IFINDEX = 999;
+constexpr int RXPACKETS = 1;
+constexpr int RXBYTES = 100;
+constexpr int TXPACKETS = 0;
+constexpr int TXBYTES = 0;
 
 #define ASSERT_VALID(x) ASSERT_TRUE((x).isValid())
+#define ASSERT_INVALID(x) ASSERT_FALSE((x).isValid())
 
 class TrafficControllerTest : public ::testing::Test {
   protected:
@@ -66,9 +77,13 @@
     BpfMap<uint64_t, UidTagValue> mFakeCookieTagMap;
     BpfMap<uint32_t, StatsValue> mFakeAppUidStatsMap;
     BpfMap<StatsKey, StatsValue> mFakeStatsMapA;
+    BpfMap<StatsKey, StatsValue> mFakeStatsMapB;  // makeTrafficControllerMapsInvalid only
+    BpfMap<uint32_t, StatsValue> mFakeIfaceStatsMap; ;  // makeTrafficControllerMapsInvalid only
     BpfMap<uint32_t, uint32_t> mFakeConfigurationMap;
     BpfMap<uint32_t, UidOwnerValue> mFakeUidOwnerMap;
     BpfMap<uint32_t, uint8_t> mFakeUidPermissionMap;
+    BpfMap<uint32_t, uint8_t> mFakeUidCounterSetMap;
+    BpfMap<uint32_t, IfaceValue> mFakeIfaceIndexNameMap;
 
     void SetUp() {
         std::lock_guard guard(mTc.mMutex);
@@ -91,6 +106,12 @@
         mFakeUidPermissionMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
         ASSERT_VALID(mFakeUidPermissionMap);
 
+        mFakeUidCounterSetMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
+        ASSERT_VALID(mFakeUidCounterSetMap);
+
+        mFakeIfaceIndexNameMap.resetMap(BPF_MAP_TYPE_HASH, TEST_MAP_SIZE);
+        ASSERT_VALID(mFakeIfaceIndexNameMap);
+
         mTc.mCookieTagMap = mFakeCookieTagMap;
         ASSERT_VALID(mTc.mCookieTagMap);
         mTc.mAppUidStatsMap = mFakeAppUidStatsMap;
@@ -108,21 +129,38 @@
         mTc.mUidPermissionMap = mFakeUidPermissionMap;
         ASSERT_VALID(mTc.mUidPermissionMap);
         mTc.mPrivilegedUser.clear();
+
+        mTc.mUidCounterSetMap = mFakeUidCounterSetMap;
+        ASSERT_VALID(mTc.mUidCounterSetMap);
+
+        mTc.mIfaceIndexNameMap = mFakeIfaceIndexNameMap;
+        ASSERT_VALID(mTc.mIfaceIndexNameMap);
     }
 
     void populateFakeStats(uint64_t cookie, uint32_t uid, uint32_t tag, StatsKey* key) {
         UidTagValue cookieMapkey = {.uid = (uint32_t)uid, .tag = tag};
         EXPECT_RESULT_OK(mFakeCookieTagMap.writeValue(cookie, cookieMapkey, BPF_ANY));
-        *key = {.uid = uid, .tag = tag, .counterSet = TEST_COUNTERSET, .ifaceIndex = 1};
-        StatsValue statsMapValue = {.rxPackets = 1, .rxBytes = 100};
-        EXPECT_RESULT_OK(mFakeStatsMapA.writeValue(*key, statsMapValue, BPF_ANY));
-        key->tag = 0;
+        *key = {.uid = uid, .tag = tag, .counterSet = TEST_COUNTERSET, .ifaceIndex = TEST_IFINDEX};
+        StatsValue statsMapValue = {.rxPackets = RXPACKETS, .rxBytes = RXBYTES,
+                                    .txPackets = TXPACKETS, .txBytes = TXBYTES};
         EXPECT_RESULT_OK(mFakeStatsMapA.writeValue(*key, statsMapValue, BPF_ANY));
         EXPECT_RESULT_OK(mFakeAppUidStatsMap.writeValue(uid, statsMapValue, BPF_ANY));
         // put tag information back to statsKey
         key->tag = tag;
     }
 
+    void populateFakeCounterSet(uint32_t uid, uint32_t counterSet) {
+        EXPECT_RESULT_OK(mFakeUidCounterSetMap.writeValue(uid, counterSet, BPF_ANY));
+    }
+
+    void populateFakeIfaceIndexName(const char* name, uint32_t ifaceIndex) {
+        if (name == nullptr || ifaceIndex <= 0) return;
+
+        IfaceValue iface;
+        strlcpy(iface.name, name, sizeof(IfaceValue));
+        EXPECT_RESULT_OK(mFakeIfaceIndexNameMap.writeValue(ifaceIndex, iface, BPF_ANY));
+    }
+
     void checkUidOwnerRuleForChain(ChildChain chain, UidOwnerMatchType match) {
         uint32_t uid = TEST_UID;
         EXPECT_EQ(0, mTc.changeUidOwnerRule(chain, uid, DENY, DENYLIST));
@@ -180,7 +218,7 @@
         checkEachUidValue(uids, match);
     }
 
-    void expectUidOwnerMapValues(const std::vector<uint32_t>& appUids, uint8_t expectedRule,
+    void expectUidOwnerMapValues(const std::vector<uint32_t>& appUids, uint32_t expectedRule,
                                  uint32_t expectedIif) {
         for (uint32_t uid : appUids) {
             Result<UidOwnerValue> value = mFakeUidOwnerMap.readValue(uid);
@@ -224,37 +262,6 @@
         EXPECT_TRUE(mTc.mPrivilegedUser.empty());
     }
 
-    void addPrivilegedUid(uid_t uid) {
-        std::vector privilegedUid = {uid};
-        mTc.setPermissionForUids(INetd::PERMISSION_UPDATE_DEVICE_STATS, privilegedUid);
-    }
-
-    void removePrivilegedUid(uid_t uid) {
-        std::vector privilegedUid = {uid};
-        mTc.setPermissionForUids(INetd::PERMISSION_NONE, privilegedUid);
-    }
-
-    void expectFakeStatsUnchanged(uint64_t cookie, uint32_t tag, uint32_t uid,
-                                  StatsKey tagStatsMapKey) {
-        Result<UidTagValue> cookieMapResult = mFakeCookieTagMap.readValue(cookie);
-        EXPECT_RESULT_OK(cookieMapResult);
-        EXPECT_EQ(uid, cookieMapResult.value().uid);
-        EXPECT_EQ(tag, cookieMapResult.value().tag);
-        Result<StatsValue> statsMapResult = mFakeStatsMapA.readValue(tagStatsMapKey);
-        EXPECT_RESULT_OK(statsMapResult);
-        EXPECT_EQ((uint64_t)1, statsMapResult.value().rxPackets);
-        EXPECT_EQ((uint64_t)100, statsMapResult.value().rxBytes);
-        tagStatsMapKey.tag = 0;
-        statsMapResult = mFakeStatsMapA.readValue(tagStatsMapKey);
-        EXPECT_RESULT_OK(statsMapResult);
-        EXPECT_EQ((uint64_t)1, statsMapResult.value().rxPackets);
-        EXPECT_EQ((uint64_t)100, statsMapResult.value().rxBytes);
-        auto appStatsResult = mFakeAppUidStatsMap.readValue(uid);
-        EXPECT_RESULT_OK(appStatsResult);
-        EXPECT_EQ((uint64_t)1, appStatsResult.value().rxPackets);
-        EXPECT_EQ((uint64_t)100, appStatsResult.value().rxBytes);
-    }
-
     Status updateUidOwnerMaps(const std::vector<uint32_t>& appUids,
                               UidOwnerMatchType matchType, TrafficController::IptOp op) {
         Status ret(0);
@@ -265,6 +272,108 @@
         return ret;
     }
 
+    Status dump(bool verbose, std::vector<std::string>& outputLines) {
+      if (!outputLines.empty()) return statusFromErrno(EUCLEAN, "Output buffer is not empty");
+
+      android::base::unique_fd localFd, remoteFd;
+      if (!Pipe(&localFd, &remoteFd)) return statusFromErrno(errno, "Failed on pipe");
+
+      // dump() blocks until another thread has consumed all its output.
+      std::thread dumpThread =
+          std::thread([this, remoteFd{std::move(remoteFd)}, verbose]() {
+            mTc.dump(remoteFd, verbose);
+          });
+
+      std::string dumpContent;
+      if (!android::base::ReadFdToString(localFd.get(), &dumpContent)) {
+        return statusFromErrno(errno, "Failed to read dump results from fd");
+      }
+      dumpThread.join();
+
+      std::stringstream dumpStream(std::move(dumpContent));
+      std::string line;
+      while (std::getline(dumpStream, line)) {
+        outputLines.push_back(line);
+      }
+
+      return netdutils::status::ok;
+    }
+
+    // Strings in the |expect| must exist in dump results in order. But no need to be consecutive.
+    bool expectDumpsysContains(std::vector<std::string>& expect) {
+        if (expect.empty()) return false;
+
+        std::vector<std::string> output;
+        Status result = dump(true, output);
+        if (!isOk(result)) {
+            GTEST_LOG_(ERROR) << "TrafficController dump failed: " << netdutils::toString(result);
+            return false;
+        }
+
+        int matched = 0;
+        auto it = expect.begin();
+        for (const auto& line : output) {
+            if (it == expect.end()) break;
+            if (std::string::npos != line.find(*it)) {
+                matched++;
+                ++it;
+            }
+        }
+
+        if (matched != expect.size()) {
+            // dump results for debugging
+            for (const auto& o : output) LOG(INFO) << "output: " << o;
+            for (const auto& e : expect) LOG(INFO) << "expect: " << e;
+            return false;
+        }
+        return true;
+    }
+
+    // Once called, the maps of TrafficController can't recover to valid maps which initialized
+    // in SetUp().
+    void makeTrafficControllerMapsInvalid() {
+        constexpr char INVALID_PATH[] = "invalid";
+
+        mFakeCookieTagMap.init(INVALID_PATH);
+        mTc.mCookieTagMap = mFakeCookieTagMap;
+        ASSERT_INVALID(mTc.mCookieTagMap);
+
+        mFakeAppUidStatsMap.init(INVALID_PATH);
+        mTc.mAppUidStatsMap = mFakeAppUidStatsMap;
+        ASSERT_INVALID(mTc.mAppUidStatsMap);
+
+        mFakeStatsMapA.init(INVALID_PATH);
+        mTc.mStatsMapA = mFakeStatsMapA;
+        ASSERT_INVALID(mTc.mStatsMapA);
+
+        mFakeStatsMapB.init(INVALID_PATH);
+        mTc.mStatsMapB = mFakeStatsMapB;
+        ASSERT_INVALID(mTc.mStatsMapB);
+
+        mFakeIfaceStatsMap.init(INVALID_PATH);
+        mTc.mIfaceStatsMap = mFakeIfaceStatsMap;
+        ASSERT_INVALID(mTc.mIfaceStatsMap);
+
+        mFakeConfigurationMap.init(INVALID_PATH);
+        mTc.mConfigurationMap = mFakeConfigurationMap;
+        ASSERT_INVALID(mTc.mConfigurationMap);
+
+        mFakeUidOwnerMap.init(INVALID_PATH);
+        mTc.mUidOwnerMap = mFakeUidOwnerMap;
+        ASSERT_INVALID(mTc.mUidOwnerMap);
+
+        mFakeUidPermissionMap.init(INVALID_PATH);
+        mTc.mUidPermissionMap = mFakeUidPermissionMap;
+        ASSERT_INVALID(mTc.mUidPermissionMap);
+
+        mFakeUidCounterSetMap.init(INVALID_PATH);
+        mTc.mUidCounterSetMap = mFakeUidCounterSetMap;
+        ASSERT_INVALID(mTc.mUidCounterSetMap);
+
+        mFakeIfaceIndexNameMap.init(INVALID_PATH);
+        mTc.mIfaceIndexNameMap = mFakeIfaceIndexNameMap;
+        ASSERT_INVALID(mTc.mIfaceIndexNameMap);
+    }
 };
 
 TEST_F(TrafficControllerTest, TestUpdateOwnerMapEntry) {
@@ -298,7 +407,6 @@
     checkUidOwnerRuleForChain(POWERSAVE, POWERSAVE_MATCH);
     checkUidOwnerRuleForChain(RESTRICTED, RESTRICTED_MATCH);
     checkUidOwnerRuleForChain(LOW_POWER_STANDBY, LOW_POWER_STANDBY_MATCH);
-    checkUidOwnerRuleForChain(LOCKDOWN, LOCKDOWN_VPN_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_1, OEM_DENY_1_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_2, OEM_DENY_2_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_3, OEM_DENY_3_MATCH);
@@ -430,6 +538,21 @@
     expectMapEmpty(mFakeUidOwnerMap);
 }
 
+TEST_F(TrafficControllerTest, TestUpdateUidLockdownRule) {
+    // Add Lockdown rules
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1000, true /* add */)));
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1001, true /* add */)));
+    expectUidOwnerMapValues({1000, 1001}, LOCKDOWN_VPN_MATCH, 0);
+
+    // Remove one of Lockdown rules
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1000, false /* add */)));
+    expectUidOwnerMapValues({1001}, LOCKDOWN_VPN_MATCH, 0);
+
+    // Remove remaining Lockdown rule
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1001, false /* add */)));
+    expectMapEmpty(mFakeUidOwnerMap);
+}
+
 TEST_F(TrafficControllerTest, TestUidInterfaceFilteringRulesCoexistWithExistingMatches) {
     // Set up existing PENALTY_BOX_MATCH rules
     ASSERT_TRUE(isOk(updateUidOwnerMaps({1000, 1001, 10012}, PENALTY_BOX_MATCH,
@@ -647,6 +770,148 @@
     expectPrivilegedUserSetEmpty();
 }
 
+TEST_F(TrafficControllerTest, TestDumpsys) {
+    StatsKey tagStatsMapKey;
+    populateFakeStats(TEST_COOKIE, TEST_UID, TEST_TAG, &tagStatsMapKey);
+    populateFakeCounterSet(TEST_UID3, TEST_COUNTERSET);
+
+    // Expect: (part of this depends on hard-code values in populateFakeStats())
+    //
+    // mCookieTagMap:
+    // cookie=1 tag=0x2a uid=10086
+    //
+    // mUidCounterSetMap:
+    // 98765 1
+    //
+    // mAppUidStatsMap::
+    // uid rxBytes rxPackets txBytes txPackets
+    // 10086 100 1 0 0
+    //
+    // mStatsMapA:
+    // ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes rxPackets txBytes txPackets
+    // 999 test0 0x2a 10086 1 100 1 0 0
+    std::vector<std::string> expectedLines = {
+        "mCookieTagMap:",
+        fmt::format("cookie={} tag={:#x} uid={}", TEST_COOKIE, TEST_TAG, TEST_UID),
+        "mUidCounterSetMap:",
+        fmt::format("{} {}", TEST_UID3, TEST_COUNTERSET),
+        "mAppUidStatsMap::",  // TODO@: fix double colon
+        "uid rxBytes rxPackets txBytes txPackets",
+        fmt::format("{} {} {} {} {}", TEST_UID, RXBYTES, RXPACKETS, TXBYTES, TXPACKETS),
+        "mStatsMapA",
+        "ifaceIndex ifaceName tag_hex uid_int cnt_set rxBytes rxPackets txBytes txPackets",
+        fmt::format("{} {} {:#x} {} {} {} {} {} {}",
+                    TEST_IFINDEX, TEST_IFNAME, TEST_TAG, TEST_UID, TEST_COUNTERSET, RXBYTES,
+                    RXPACKETS, TXBYTES, TXPACKETS)};
+
+    populateFakeIfaceIndexName(TEST_IFNAME, TEST_IFINDEX);
+    expectedLines.emplace_back("mIfaceIndexNameMap:");
+    expectedLines.emplace_back(fmt::format("ifaceIndex={} ifaceName={}",
+                                           TEST_IFINDEX, TEST_IFNAME));
+
+    ASSERT_TRUE(isOk(updateUidOwnerMaps({TEST_UID}, HAPPY_BOX_MATCH,
+                                        TrafficController::IptOpInsert)));
+    expectedLines.emplace_back("mUidOwnerMap:");
+    expectedLines.emplace_back(fmt::format("{}  HAPPY_BOX_MATCH", TEST_UID));
+
+    mTc.setPermissionForUids(INetd::PERMISSION_UPDATE_DEVICE_STATS, {TEST_UID2});
+    expectedLines.emplace_back("mUidPermissionMap:");
+    expectedLines.emplace_back(fmt::format("{}  BPF_PERMISSION_UPDATE_DEVICE_STATS", TEST_UID2));
+    expectedLines.emplace_back("mPrivilegedUser:");
+    expectedLines.emplace_back(fmt::format("{} ALLOW_UPDATE_DEVICE_STATS", TEST_UID2));
+    EXPECT_TRUE(expectDumpsysContains(expectedLines));
+}
+
+TEST_F(TrafficControllerTest, dumpsysInvalidMaps) {
+    makeTrafficControllerMapsInvalid();
+
+    const std::string kErrIterate = "print end with error: Get firstKey map -1 failed: "
+            "Bad file descriptor";
+    const std::string kErrReadRulesConfig = "read ownerMatch configure failed with error: "
+            "Read value of map -1 failed: Bad file descriptor";
+    const std::string kErrReadStatsMapConfig = "read stats map configure failed with error: "
+            "Read value of map -1 failed: Bad file descriptor";
+
+    std::vector<std::string> expectedLines = {
+        fmt::format("mCookieTagMap {}", kErrIterate),
+        fmt::format("mUidCounterSetMap {}", kErrIterate),
+        fmt::format("mAppUidStatsMap {}", kErrIterate),
+        fmt::format("mStatsMapA {}", kErrIterate),
+        fmt::format("mStatsMapB {}", kErrIterate),
+        fmt::format("mIfaceIndexNameMap {}", kErrIterate),
+        fmt::format("mIfaceStatsMap {}", kErrIterate),
+        fmt::format("mConfigurationMap {}", kErrReadRulesConfig),
+        fmt::format("mConfigurationMap {}", kErrReadStatsMapConfig),
+        fmt::format("mUidOwnerMap {}", kErrIterate),
+        fmt::format("mUidPermissionMap {}", kErrIterate)};
+    EXPECT_TRUE(expectDumpsysContains(expectedLines));
+}
+
+TEST_F(TrafficControllerTest, uidMatchTypeToString) {
+    // NO_MATCH(0) can't be verified because match type flag is added by OR operator.
+    // See TrafficController::addRule()
+    static const struct TestConfig {
+        UidOwnerMatchType uidOwnerMatchType;
+        std::string expected;
+    } testConfigs[] = {
+            // clang-format off
+            {HAPPY_BOX_MATCH, "HAPPY_BOX_MATCH"},
+            {DOZABLE_MATCH, "DOZABLE_MATCH"},
+            {STANDBY_MATCH, "STANDBY_MATCH"},
+            {POWERSAVE_MATCH, "POWERSAVE_MATCH"},
+            {HAPPY_BOX_MATCH, "HAPPY_BOX_MATCH"},
+            {RESTRICTED_MATCH, "RESTRICTED_MATCH"},
+            {LOW_POWER_STANDBY_MATCH, "LOW_POWER_STANDBY_MATCH"},
+            {IIF_MATCH, "IIF_MATCH"},
+            {LOCKDOWN_VPN_MATCH, "LOCKDOWN_VPN_MATCH"},
+            {OEM_DENY_1_MATCH, "OEM_DENY_1_MATCH"},
+            {OEM_DENY_2_MATCH, "OEM_DENY_2_MATCH"},
+            {OEM_DENY_3_MATCH, "OEM_DENY_3_MATCH"},
+            // clang-format on
+    };
+
+    for (const auto& config : testConfigs) {
+        SCOPED_TRACE(fmt::format("testConfig: [{}, {}]", config.uidOwnerMatchType,
+                     config.expected));
+
+        // Test private function uidMatchTypeToString() via dumpsys.
+        ASSERT_TRUE(isOk(updateUidOwnerMaps({TEST_UID}, config.uidOwnerMatchType,
+                                            TrafficController::IptOpInsert)));
+        std::vector<std::string> expectedLines;
+        expectedLines.emplace_back(fmt::format("{}  {}", TEST_UID, config.expected));
+        EXPECT_TRUE(expectDumpsysContains(expectedLines));
+
+        // Clean up the stubs.
+        ASSERT_TRUE(isOk(updateUidOwnerMaps({TEST_UID}, config.uidOwnerMatchType,
+                                            TrafficController::IptOpDelete)));
+    }
+}
+
+TEST_F(TrafficControllerTest, getFirewallType) {
+    static const struct TestConfig {
+        ChildChain childChain;
+        FirewallType firewallType;
+    } testConfigs[] = {
+            // clang-format off
+            {NONE, DENYLIST},
+            {DOZABLE, ALLOWLIST},
+            {STANDBY, DENYLIST},
+            {POWERSAVE, ALLOWLIST},
+            {RESTRICTED, ALLOWLIST},
+            {LOW_POWER_STANDBY, ALLOWLIST},
+            {OEM_DENY_1, DENYLIST},
+            {OEM_DENY_2, DENYLIST},
+            {OEM_DENY_3, DENYLIST},
+            {INVALID_CHAIN, DENYLIST},
+            // clang-format on
+    };
+
+    for (const auto& config : testConfigs) {
+        SCOPED_TRACE(fmt::format("testConfig: [{}, {}]", config.childChain, config.firewallType));
+        EXPECT_EQ(config.firewallType, mTc.getFirewallType(config.childChain));
+    }
+}
+
 constexpr uint32_t SOCK_CLOSE_WAIT_US = 30 * 1000;
 constexpr uint32_t ENOBUFS_POLL_WAIT_US = 10 * 1000;
 
@@ -682,7 +947,7 @@
                 if (res.ok() || (res.error().code() == ENOENT)) {
                     return Result<void>();
                 }
-                ALOGE("Failed to delete data(cookie = %" PRIu64 "): %s\n", key,
+                ALOGE("Failed to delete data(cookie = %" PRIu64 "): %s", key,
                       strerror(res.error().code()));
             }
             // Move forward to next cookie in the map.
diff --git a/service/native/include/Common.h b/service/native/include/Common.h
index c9653ad..03f449a 100644
--- a/service/native/include/Common.h
+++ b/service/native/include/Common.h
@@ -38,7 +38,6 @@
     POWERSAVE = 3,
     RESTRICTED = 4,
     LOW_POWER_STANDBY = 5,
-    LOCKDOWN = 6,
     OEM_DENY_1 = 7,
     OEM_DENY_2 = 8,
     OEM_DENY_3 = 9,
diff --git a/service/native/include/TrafficController.h b/service/native/include/TrafficController.h
index c019ce7..14c5eaf 100644
--- a/service/native/include/TrafficController.h
+++ b/service/native/include/TrafficController.h
@@ -45,11 +45,6 @@
      */
     netdutils::Status swapActiveStatsMap() EXCLUDES(mMutex);
 
-    /*
-     * Add the interface name and index pair into the eBPF map.
-     */
-    int addInterface(const char* name, uint32_t ifaceIndex);
-
     int changeUidOwnerRule(ChildChain chain, const uid_t uid, FirewallRule rule, FirewallType type);
 
     int removeUidOwnerRule(const uid_t uid);
@@ -71,11 +66,11 @@
             EXCLUDES(mMutex);
     netdutils::Status removeUidInterfaceRules(const std::vector<int32_t>& uids) EXCLUDES(mMutex);
 
+    netdutils::Status updateUidLockdownRule(const uid_t uid, const bool add) EXCLUDES(mMutex);
+
     netdutils::Status updateUidOwnerMap(const uint32_t uid,
                                         UidOwnerMatchType matchType, IptOp op) EXCLUDES(mMutex);
 
-    int toggleUidOwnerMap(ChildChain chain, bool enable) EXCLUDES(mMutex);
-
     static netdutils::StatusOr<std::unique_ptr<netdutils::NetlinkListenerInterface>>
     makeSkDestroyListener();
 
@@ -185,8 +180,6 @@
     // need to call back to system server for permission check.
     std::set<uid_t> mPrivilegedUser GUARDED_BY(mMutex);
 
-    bool hasUpdateDeviceStatsPermission(uid_t uid) REQUIRES(mMutex);
-
     // For testing
     friend class TrafficControllerTest;
 };
diff --git a/service/native/libs/libclat/Android.bp b/service/native/libs/libclat/Android.bp
index 68e4dc4..54d40ac 100644
--- a/service/native/libs/libclat/Android.bp
+++ b/service/native/libs/libclat/Android.bp
@@ -35,7 +35,8 @@
 cc_test {
     name: "libclat_test",
     defaults: ["netd_defaults"],
-    test_suites: ["device-tests"],
+    test_suites: ["general-tests", "mts-tethering"],
+    test_config_template: ":net_native_test_config_template",
     srcs: [
         "clatutils_test.cpp",
     ],
@@ -49,5 +50,14 @@
         "liblog",
         "libnetutils",
     ],
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            suffix: "32",
+        },
+        lib64: {
+            suffix: "64",
+        },
+    },
     require_root: true,
 }
diff --git a/service/native/libs/libclat/clatutils_test.cpp b/service/native/libs/libclat/clatutils_test.cpp
index 4153e19..8cca1f4 100644
--- a/service/native/libs/libclat/clatutils_test.cpp
+++ b/service/native/libs/libclat/clatutils_test.cpp
@@ -19,6 +19,7 @@
 #include <gtest/gtest.h>
 #include <linux/if_packet.h>
 #include <linux/if_tun.h>
+#include <netinet/in.h>
 #include "tun_interface.h"
 
 extern "C" {
@@ -182,6 +183,31 @@
     v6Iface.destroy();
 }
 
+// This is not a realistic test because we can't test generateIPv6Address here since it requires
+// manipulating routing, which we can't do without talking to the real netd on the system.
+// See test MakeChecksumNeutral.
+// TODO: remove this test once EthernetTetheringTest can test on mainline test coverage branch.
+TEST_F(ClatUtils, GenerateIpv6AddressFailWithUlaSocketAddress) {
+    // Create an interface for generateIpv6Address to connect to.
+    TunInterface tun;
+    ASSERT_EQ(0, tun.init());
+
+    // Unused because v6 address is ULA and makeChecksumNeutral has never called.
+    in_addr v4 = {inet_addr(kIPv4LocalAddr)};
+    // Not a NAT64 prefix because test can't connect to in generateIpv6Address.
+    // Used to be a fake address from the tun interface for generating an IPv6 socket address.
+    // nat64Prefix won't be used in MakeChecksumNeutral because MakeChecksumNeutral has never
+    // be called.
+    in6_addr nat64Prefix = tun.dstAddr();  // not realistic
+    in6_addr v6;
+    EXPECT_EQ(1, inet_pton(AF_INET6, "::", &v6));  // initialize as zero
+
+    EXPECT_EQ(-ENETUNREACH, generateIpv6Address(tun.name().c_str(), v4, nat64Prefix, &v6));
+    EXPECT_TRUE(IN6_IS_ADDR_ULA(&v6));
+
+    tun.destroy();
+}
+
 }  // namespace clat
 }  // namespace net
 }  // namespace android
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index c006bc6..648ada2 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -16,15 +16,32 @@
 
 package com.android.server;
 
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_DOZABLE;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOW_POWER_STANDBY;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_1;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_2;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_3;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_POWERSAVE;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_RESTRICTED;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_STANDBY;
+import static android.system.OsConstants.EINVAL;
+import static android.system.OsConstants.ENODEV;
+import static android.system.OsConstants.ENOENT;
 import static android.system.OsConstants.EOPNOTSUPP;
 
 import android.net.INetd;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
+import android.system.ErrnoException;
 import android.system.Os;
 import android.util.Log;
+import android.util.SparseLongArray;
 
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.BpfMap;
+import com.android.net.module.util.Struct.U32;
 
 import java.io.FileDescriptor;
 import java.io.IOException;
@@ -35,35 +52,162 @@
  * {@hide}
  */
 public class BpfNetMaps {
+    private static final boolean PRE_T = !SdkLevel.isAtLeastT();
+    static {
+        if (!PRE_T) {
+            System.loadLibrary("service-connectivity");
+        }
+    }
+
     private static final String TAG = "BpfNetMaps";
     private final INetd mNetd;
+    private final Dependencies mDeps;
     // Use legacy netd for releases before T.
-    private static final boolean USE_NETD = !SdkLevel.isAtLeastT();
     private static boolean sInitialized = false;
 
+    // Lock for sConfigurationMap entry for UID_RULES_CONFIGURATION_KEY.
+    // This entry is not accessed by others.
+    // BpfNetMaps acquires this lock while sequence of read, modify, and write.
+    private static final Object sUidRulesConfigBpfMapLock = new Object();
+
+    private static final String CONFIGURATION_MAP_PATH =
+            "/sys/fs/bpf/netd_shared/map_netd_configuration_map";
+    private static final String UID_OWNER_MAP_PATH =
+            "/sys/fs/bpf/netd_shared/map_netd_uid_owner_map";
+    private static final U32 UID_RULES_CONFIGURATION_KEY = new U32(0);
+    private static BpfMap<U32, U32> sConfigurationMap = null;
+    // BpfMap for UID_OWNER_MAP_PATH. This map is not accessed by others.
+    private static BpfMap<U32, UidOwnerValue> sUidOwnerMap = null;
+
+    // LINT.IfChange(match_type)
+    @VisibleForTesting public static final long NO_MATCH = 0;
+    @VisibleForTesting public static final long HAPPY_BOX_MATCH = (1 << 0);
+    @VisibleForTesting public static final long PENALTY_BOX_MATCH = (1 << 1);
+    @VisibleForTesting public static final long DOZABLE_MATCH = (1 << 2);
+    @VisibleForTesting public static final long STANDBY_MATCH = (1 << 3);
+    @VisibleForTesting public static final long POWERSAVE_MATCH = (1 << 4);
+    @VisibleForTesting public static final long RESTRICTED_MATCH = (1 << 5);
+    @VisibleForTesting public static final long LOW_POWER_STANDBY_MATCH = (1 << 6);
+    @VisibleForTesting public static final long IIF_MATCH = (1 << 7);
+    @VisibleForTesting public static final long LOCKDOWN_VPN_MATCH = (1 << 8);
+    @VisibleForTesting public static final long OEM_DENY_1_MATCH = (1 << 9);
+    @VisibleForTesting public static final long OEM_DENY_2_MATCH = (1 << 10);
+    @VisibleForTesting public static final long OEM_DENY_3_MATCH = (1 << 11);
+    // LINT.ThenChange(packages/modules/Connectivity/bpf_progs/bpf_shared.h)
+
+    // TODO: Use Java BpfMap instead of JNI code (TrafficController) for map update.
+    // Currently, BpfNetMaps uses TrafficController for map update and TrafficController
+    // (changeUidOwnerRule and toggleUidOwnerMap) also does conversion from "firewall chain" to
+    // "match". Migrating map update from JNI to Java BpfMap will solve this duplication.
+    private static final SparseLongArray FIREWALL_CHAIN_TO_MATCH = new SparseLongArray();
+    static {
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_DOZABLE, DOZABLE_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_STANDBY, STANDBY_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_POWERSAVE, POWERSAVE_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_RESTRICTED, RESTRICTED_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_LOW_POWER_STANDBY, LOW_POWER_STANDBY_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_OEM_DENY_1, OEM_DENY_1_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_OEM_DENY_2, OEM_DENY_2_MATCH);
+        FIREWALL_CHAIN_TO_MATCH.put(FIREWALL_CHAIN_OEM_DENY_3, OEM_DENY_3_MATCH);
+    }
+
+    /**
+     * Set configurationMap for test.
+     */
+    @VisibleForTesting
+    public static void setConfigurationMapForTest(BpfMap<U32, U32> configurationMap) {
+        sConfigurationMap = configurationMap;
+    }
+
+    /**
+     * Set uidOwnerMap for test.
+     */
+    @VisibleForTesting
+    public static void setUidOwnerMapForTest(BpfMap<U32, UidOwnerValue> uidOwnerMap) {
+        sUidOwnerMap = uidOwnerMap;
+    }
+
+    private static BpfMap<U32, U32> getConfigurationMap() {
+        try {
+            return new BpfMap<>(
+                    CONFIGURATION_MAP_PATH, BpfMap.BPF_F_RDWR, U32.class, U32.class);
+        } catch (ErrnoException e) {
+            throw new IllegalStateException("Cannot open netd configuration map", e);
+        }
+    }
+
+    private static BpfMap<U32, UidOwnerValue> getUidOwnerMap() {
+        try {
+            return new BpfMap<>(
+                    UID_OWNER_MAP_PATH, BpfMap.BPF_F_RDWR, U32.class, UidOwnerValue.class);
+        } catch (ErrnoException e) {
+            throw new IllegalStateException("Cannot open uid owner map", e);
+        }
+    }
+
+    private static void setBpfMaps() {
+        if (sConfigurationMap == null) {
+            sConfigurationMap = getConfigurationMap();
+        }
+        if (sUidOwnerMap == null) {
+            sUidOwnerMap = getUidOwnerMap();
+        }
+    }
+
     /**
      * Initializes the class if it is not already initialized. This method will open maps but not
      * cause any other effects. This method may be called multiple times on any thread.
      */
     private static synchronized void ensureInitialized() {
         if (sInitialized) return;
-        if (!USE_NETD) {
-            System.loadLibrary("service-connectivity");
-            native_init();
-        }
+        setBpfMaps();
+        native_init();
         sInitialized = true;
     }
 
+    /**
+     * Dependencies of BpfNetMaps, for injection in tests.
+     */
+    @VisibleForTesting
+    public static class Dependencies {
+        /**
+         * Get interface index.
+         */
+        public int getIfIndex(final String ifName) {
+            return Os.if_nametoindex(ifName);
+        }
+    }
+
     /** Constructor used after T that doesn't need to use netd anymore. */
     public BpfNetMaps() {
         this(null);
 
-        if (USE_NETD) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
+        if (PRE_T) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
     }
 
-    public BpfNetMaps(INetd netd) {
-        ensureInitialized();
+    public BpfNetMaps(final INetd netd) {
+        this(netd, new Dependencies());
+    }
+
+    @VisibleForTesting
+    public BpfNetMaps(final INetd netd, final Dependencies deps) {
+        if (!PRE_T) {
+            ensureInitialized();
+        }
         mNetd = netd;
+        mDeps = deps;
+    }
+
+    /**
+     * Get corresponding match from firewall chain.
+     */
+    @VisibleForTesting
+    public long getMatchByFirewallChain(final int chain) {
+        final long match = FIREWALL_CHAIN_TO_MATCH.get(chain, NO_MATCH);
+        if (match == NO_MATCH) {
+            throw new ServiceSpecificException(EINVAL, "Invalid firewall chain: " + chain);
+        }
+        return match;
     }
 
     private void maybeThrow(final int err, final String msg) {
@@ -72,6 +216,73 @@
         }
     }
 
+    private void throwIfPreT(final String msg) {
+        if (PRE_T) {
+            throw new UnsupportedOperationException(msg);
+        }
+    }
+
+    private void removeRule(final int uid, final long match, final String caller) {
+        try {
+            synchronized (sUidOwnerMap) {
+                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new U32(uid));
+
+                if (oldMatch == null) {
+                    throw new ServiceSpecificException(ENOENT,
+                            "sUidOwnerMap does not have entry for uid: " + uid);
+                }
+
+                final UidOwnerValue newMatch = new UidOwnerValue(
+                        (match == IIF_MATCH) ? 0 : oldMatch.iif,
+                        oldMatch.rule & ~match
+                );
+
+                if (newMatch.rule == 0) {
+                    sUidOwnerMap.deleteEntry(new U32(uid));
+                } else {
+                    sUidOwnerMap.updateEntry(new U32(uid), newMatch);
+                }
+            }
+        } catch (ErrnoException e) {
+            throw new ServiceSpecificException(e.errno,
+                    caller + " failed to remove rule: " + Os.strerror(e.errno));
+        }
+    }
+
+    private void addRule(final int uid, final long match, final long iif, final String caller) {
+        if (match != IIF_MATCH && iif != 0) {
+            throw new ServiceSpecificException(EINVAL,
+                    "Non-interface match must have zero interface index");
+        }
+
+        try {
+            synchronized (sUidOwnerMap) {
+                final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new U32(uid));
+
+                final UidOwnerValue newMatch;
+                if (oldMatch != null) {
+                    newMatch = new UidOwnerValue(
+                            (match == IIF_MATCH) ? iif : oldMatch.iif,
+                            oldMatch.rule | match
+                    );
+                } else {
+                    newMatch = new UidOwnerValue(
+                            iif,
+                            match
+                    );
+                }
+                sUidOwnerMap.updateEntry(new U32(uid), newMatch);
+            }
+        } catch (ErrnoException e) {
+            throw new ServiceSpecificException(e.errno,
+                    caller + " failed to add rule: " + Os.strerror(e.errno));
+        }
+    }
+
+    private void addRule(final int uid, final long match, final String caller) {
+        addRule(uid, match, 0 /* iif */, caller);
+    }
+
     /**
      * Add naughty app bandwidth rule for specific app
      *
@@ -80,8 +291,8 @@
      *                                  cause of the failure.
      */
     public void addNaughtyApp(final int uid) {
-        final int err = native_addNaughtyApp(uid);
-        maybeThrow(err, "Unable to add naughty app");
+        throwIfPreT("addNaughtyApp is not available on pre-T devices");
+        addRule(uid, PENALTY_BOX_MATCH, "addNaughtyApp");
     }
 
     /**
@@ -92,8 +303,8 @@
      *                                  cause of the failure.
      */
     public void removeNaughtyApp(final int uid) {
-        final int err = native_removeNaughtyApp(uid);
-        maybeThrow(err, "Unable to remove naughty app");
+        throwIfPreT("removeNaughtyApp is not available on pre-T devices");
+        removeRule(uid, PENALTY_BOX_MATCH, "removeNaughtyApp");
     }
 
     /**
@@ -104,8 +315,8 @@
      *                                  cause of the failure.
      */
     public void addNiceApp(final int uid) {
-        final int err = native_addNiceApp(uid);
-        maybeThrow(err, "Unable to add nice app");
+        throwIfPreT("addNiceApp is not available on pre-T devices");
+        addRule(uid, HAPPY_BOX_MATCH, "addNiceApp");
     }
 
     /**
@@ -116,8 +327,8 @@
      *                                  cause of the failure.
      */
     public void removeNiceApp(final int uid) {
-        final int err = native_removeNiceApp(uid);
-        maybeThrow(err, "Unable to remove nice app");
+        throwIfPreT("removeNiceApp is not available on pre-T devices");
+        removeRule(uid, HAPPY_BOX_MATCH, "removeNiceApp");
     }
 
     /**
@@ -125,12 +336,46 @@
      *
      * @param childChain target chain to enable
      * @param enable     whether to enable or disable child chain.
+     * @throws UnsupportedOperationException if called on pre-T devices.
      * @throws ServiceSpecificException in case of failure, with an error code indicating the
      *                                  cause of the failure.
      */
     public void setChildChain(final int childChain, final boolean enable) {
-        final int err = native_setChildChain(childChain, enable);
-        maybeThrow(err, "Unable to set child chain");
+        throwIfPreT("setChildChain is not available on pre-T devices");
+
+        final long match = getMatchByFirewallChain(childChain);
+        try {
+            synchronized (sUidRulesConfigBpfMapLock) {
+                final U32 config = sConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY);
+                final long newConfig = enable ? (config.val | match) : (config.val & ~match);
+                sConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY, new U32(newConfig));
+            }
+        } catch (ErrnoException e) {
+            throw new ServiceSpecificException(e.errno,
+                    "Unable to set child chain: " + Os.strerror(e.errno));
+        }
+    }
+
+    /**
+     * Get the specified firewall chain's status.
+     *
+     * @param childChain target chain
+     * @return {@code true} if chain is enabled, {@code false} if chain is not enabled.
+     * @throws UnsupportedOperationException if called on pre-T devices.
+     * @throws ServiceSpecificException in case of failure, with an error code indicating the
+     *                                  cause of the failure.
+     */
+    public boolean isChainEnabled(final int childChain) {
+        throwIfPreT("isChainEnabled is not available on pre-T devices");
+
+        final long match = getMatchByFirewallChain(childChain);
+        try {
+            final U32 config = sConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY);
+            return (config.val & match) != 0;
+        } catch (ErrnoException e) {
+            throw new ServiceSpecificException(e.errno,
+                    "Unable to get firewall chain status: " + Os.strerror(e.errno));
+        }
     }
 
     /**
@@ -148,11 +393,13 @@
      */
     public int replaceUidChain(final String chainName, final boolean isAllowlist,
             final int[] uids) {
-        final int err = native_replaceUidChain(chainName, isAllowlist, uids);
-        if (err != 0) {
-            Log.e(TAG, "replaceUidChain failed: " + Os.strerror(-err));
+        synchronized (sUidOwnerMap) {
+            final int err = native_replaceUidChain(chainName, isAllowlist, uids);
+            if (err != 0) {
+                Log.e(TAG, "replaceUidChain failed: " + Os.strerror(-err));
+            }
+            return -err;
         }
-        return -err;
     }
 
     /**
@@ -165,8 +412,10 @@
      *                                  cause of the failure.
      */
     public void setUidRule(final int childChain, final int uid, final int firewallRule) {
-        final int err = native_setUidRule(childChain, uid, firewallRule);
-        maybeThrow(err, "Unable to set uid rule");
+        synchronized (sUidOwnerMap) {
+            final int err = native_setUidRule(childChain, uid, firewallRule);
+            maybeThrow(err, "Unable to set uid rule");
+        }
     }
 
     /**
@@ -187,12 +436,29 @@
      *                                  cause of the failure.
      */
     public void addUidInterfaceRules(final String ifName, final int[] uids) throws RemoteException {
-        if (USE_NETD) {
+        if (PRE_T) {
             mNetd.firewallAddUidInterfaceRules(ifName, uids);
             return;
         }
-        final int err = native_addUidInterfaceRules(ifName, uids);
-        maybeThrow(err, "Unable to add uid interface rules");
+        // Null ifName is a wildcard to allow apps to receive packets on all interfaces and ifIndex
+        // is set to 0.
+        final int ifIndex;
+        if (ifName == null) {
+            ifIndex = 0;
+        } else {
+            ifIndex = mDeps.getIfIndex(ifName);
+            if (ifIndex == 0) {
+                throw new ServiceSpecificException(ENODEV,
+                        "Failed to get index of interface " + ifName);
+            }
+        }
+        for (final int uid: uids) {
+            try {
+                addRule(uid, IIF_MATCH, ifIndex, "addUidInterfaceRules");
+            } catch (ServiceSpecificException e) {
+                Log.e(TAG, "addRule failed uid=" + uid + " ifName=" + ifName + ", " + e);
+            }
+        }
     }
 
     /**
@@ -207,12 +473,34 @@
      *                                  cause of the failure.
      */
     public void removeUidInterfaceRules(final int[] uids) throws RemoteException {
-        if (USE_NETD) {
+        if (PRE_T) {
             mNetd.firewallRemoveUidInterfaceRules(uids);
             return;
         }
-        final int err = native_removeUidInterfaceRules(uids);
-        maybeThrow(err, "Unable to remove uid interface rules");
+        for (final int uid: uids) {
+            try {
+                removeRule(uid, IIF_MATCH, "removeUidInterfaceRules");
+            } catch (ServiceSpecificException e) {
+                Log.e(TAG, "removeRule failed uid=" + uid + ", " + e);
+            }
+        }
+    }
+
+    /**
+     * Update lockdown rule for uid
+     *
+     * @param  uid          target uid to add/remove the rule
+     * @param  add          {@code true} to add the rule, {@code false} to remove the rule.
+     * @throws ServiceSpecificException in case of failure, with an error code indicating the
+     *                                  cause of the failure.
+     */
+    public void updateUidLockdownRule(final int uid, final boolean add) {
+        throwIfPreT("updateUidLockdownRule is not available on pre-T devices");
+        if (add) {
+            addRule(uid, LOCKDOWN_VPN_MATCH, "updateUidLockdownRule");
+        } else {
+            removeRule(uid, LOCKDOWN_VPN_MATCH, "updateUidLockdownRule");
+        }
     }
 
     /**
@@ -237,7 +525,7 @@
      * @throws RemoteException when netd has crashed.
      */
     public void setNetPermForUids(final int permissions, final int[] uids) throws RemoteException {
-        if (USE_NETD) {
+        if (PRE_T) {
             mNetd.trafficSetNetPermForUids(permissions, uids);
             return;
         }
@@ -253,7 +541,7 @@
      */
     public void dump(final FileDescriptor fd, boolean verbose)
             throws IOException, ServiceSpecificException {
-        if (USE_NETD) {
+        if (PRE_T) {
             throw new ServiceSpecificException(
                     EOPNOTSUPP, "dumpsys connectivity trafficcontroller dump not available on pre-T"
                     + " devices, use dumpsys netd trafficcontroller instead.");
@@ -262,15 +550,24 @@
     }
 
     private static native void native_init();
+    @GuardedBy("sUidOwnerMap")
     private native int native_addNaughtyApp(int uid);
+    @GuardedBy("sUidOwnerMap")
     private native int native_removeNaughtyApp(int uid);
+    @GuardedBy("sUidOwnerMap")
     private native int native_addNiceApp(int uid);
+    @GuardedBy("sUidOwnerMap")
     private native int native_removeNiceApp(int uid);
-    private native int native_setChildChain(int childChain, boolean enable);
+    @GuardedBy("sUidOwnerMap")
     private native int native_replaceUidChain(String name, boolean isAllowlist, int[] uids);
+    @GuardedBy("sUidOwnerMap")
     private native int native_setUidRule(int childChain, int uid, int firewallRule);
+    @GuardedBy("sUidOwnerMap")
     private native int native_addUidInterfaceRules(String ifName, int[] uids);
+    @GuardedBy("sUidOwnerMap")
     private native int native_removeUidInterfaceRules(int[] uids);
+    @GuardedBy("sUidOwnerMap")
+    private native int native_updateUidLockdownRule(int uid, boolean add);
     private native int native_swapActiveStatsMap();
     private native void native_setPermissionForUids(int permissions, int[] uids);
     private native void native_dump(FileDescriptor fd, boolean verbose);
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index d0cb294..d6f3396 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -98,6 +98,9 @@
 import static android.system.OsConstants.IPPROTO_UDP;
 
 import static com.android.net.module.util.DeviceConfigUtils.TETHERING_MODULE_NAME;
+import static com.android.net.module.util.PermissionUtils.enforceAnyPermissionOf;
+import static com.android.net.module.util.PermissionUtils.enforceNetworkStackPermission;
+import static com.android.net.module.util.PermissionUtils.enforceNetworkStackPermissionOr;
 
 import static java.util.Map.Entry;
 
@@ -1956,7 +1959,7 @@
 
     @Override
     public Network getActiveNetworkForUid(int uid, boolean ignoreBlocked) {
-        PermissionUtils.enforceNetworkStackPermission(mContext);
+        enforceNetworkStackPermission(mContext);
         return getActiveNetworkForUidInternal(uid, ignoreBlocked);
     }
 
@@ -1979,7 +1982,7 @@
 
     @Override
     public NetworkInfo getActiveNetworkInfoForUid(int uid, boolean ignoreBlocked) {
-        PermissionUtils.enforceNetworkStackPermission(mContext);
+        enforceNetworkStackPermission(mContext);
         final NetworkAgentInfo nai = getNetworkAgentInfoForUid(uid);
         if (nai == null) return null;
         return getFilteredNetworkInfo(nai, uid, ignoreBlocked);
@@ -2518,7 +2521,7 @@
     @Override
     public NetworkState[] getAllNetworkState() {
         // This contains IMSI details, so make sure the caller is privileged.
-        PermissionUtils.enforceNetworkStackPermission(mContext);
+        enforceNetworkStackPermission(mContext);
 
         final ArrayList<NetworkState> result = new ArrayList<>();
         for (NetworkStateSnapshot snapshot : getAllNetworkStateSnapshots()) {
@@ -2783,15 +2786,6 @@
         setUidBlockedReasons(uid, blockedReasons);
     }
 
-    private boolean checkAnyPermissionOf(String... permissions) {
-        for (String permission : permissions) {
-            if (mContext.checkCallingOrSelfPermission(permission) == PERMISSION_GRANTED) {
-                return true;
-            }
-        }
-        return false;
-    }
-
     private boolean checkAnyPermissionOf(int pid, int uid, String... permissions) {
         for (String permission : permissions) {
             if (mContext.checkPermission(permission, pid, uid) == PERMISSION_GRANTED) {
@@ -2801,13 +2795,6 @@
         return false;
     }
 
-    private void enforceAnyPermissionOf(String... permissions) {
-        if (!checkAnyPermissionOf(permissions)) {
-            throw new SecurityException("Requires one of the following permissions: "
-                    + String.join(", ", permissions) + ".");
-        }
-    }
-
     private void enforceInternetPermission() {
         mContext.enforceCallingOrSelfPermission(
                 android.Manifest.permission.INTERNET,
@@ -2867,7 +2854,7 @@
     }
 
     private void enforceSettingsPermission() {
-        enforceAnyPermissionOf(
+        enforceAnyPermissionOf(mContext,
                 android.Manifest.permission.NETWORK_SETTINGS,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
     }
@@ -2875,7 +2862,7 @@
     private void enforceNetworkFactoryPermission() {
         // TODO: Check for the BLUETOOTH_STACK permission once that is in the API surface.
         if (UserHandle.getAppId(getCallingUid()) == Process.BLUETOOTH_UID) return;
-        enforceAnyPermissionOf(
+        enforceAnyPermissionOf(mContext,
                 android.Manifest.permission.NETWORK_FACTORY,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
     }
@@ -2883,7 +2870,7 @@
     private void enforceNetworkFactoryOrSettingsPermission() {
         // TODO: Check for the BLUETOOTH_STACK permission once that is in the API surface.
         if (UserHandle.getAppId(getCallingUid()) == Process.BLUETOOTH_UID) return;
-        enforceAnyPermissionOf(
+        enforceAnyPermissionOf(mContext,
                 android.Manifest.permission.NETWORK_SETTINGS,
                 android.Manifest.permission.NETWORK_FACTORY,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
@@ -2892,7 +2879,7 @@
     private void enforceNetworkFactoryOrTestNetworksPermission() {
         // TODO: Check for the BLUETOOTH_STACK permission once that is in the API surface.
         if (UserHandle.getAppId(getCallingUid()) == Process.BLUETOOTH_UID) return;
-        enforceAnyPermissionOf(
+        enforceAnyPermissionOf(mContext,
                 android.Manifest.permission.MANAGE_TEST_NETWORKS,
                 android.Manifest.permission.NETWORK_FACTORY,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
@@ -2909,7 +2896,7 @@
     }
 
     private boolean checkSettingsPermission() {
-        return checkAnyPermissionOf(
+        return PermissionUtils.checkAnyPermissionOf(mContext,
                 android.Manifest.permission.NETWORK_SETTINGS,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
     }
@@ -2922,27 +2909,21 @@
     }
 
     private void enforceNetworkStackOrSettingsPermission() {
-        enforceAnyPermissionOf(
-                android.Manifest.permission.NETWORK_SETTINGS,
-                android.Manifest.permission.NETWORK_STACK,
-                NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+        enforceNetworkStackPermissionOr(mContext,
+                android.Manifest.permission.NETWORK_SETTINGS);
     }
 
     private void enforceNetworkStackSettingsOrSetup() {
-        enforceAnyPermissionOf(
+        enforceNetworkStackPermissionOr(mContext,
                 android.Manifest.permission.NETWORK_SETTINGS,
-                android.Manifest.permission.NETWORK_SETUP_WIZARD,
-                android.Manifest.permission.NETWORK_STACK,
-                NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+                android.Manifest.permission.NETWORK_SETUP_WIZARD);
     }
 
     private void enforceAirplaneModePermission() {
-        enforceAnyPermissionOf(
+        enforceNetworkStackPermissionOr(mContext,
                 android.Manifest.permission.NETWORK_AIRPLANE_MODE,
                 android.Manifest.permission.NETWORK_SETTINGS,
-                android.Manifest.permission.NETWORK_SETUP_WIZARD,
-                android.Manifest.permission.NETWORK_STACK,
-                NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+                android.Manifest.permission.NETWORK_SETUP_WIZARD);
     }
 
     private void enforceOemNetworkPreferencesPermission() {
@@ -2958,7 +2939,7 @@
     }
 
     private boolean checkNetworkStackPermission() {
-        return checkAnyPermissionOf(
+        return PermissionUtils.checkAnyPermissionOf(mContext,
                 android.Manifest.permission.NETWORK_STACK,
                 NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
     }
@@ -3422,12 +3403,27 @@
         pw.increaseIndent();
         mNetworkActivityTracker.dump(pw);
         pw.decreaseIndent();
+
+        // pre-T is logged by netd.
+        if (SdkLevel.isAtLeastT()) {
+            pw.println();
+            pw.println("BPF programs & maps:");
+            pw.increaseIndent();
+            // Flush is required. Otherwise, the traces in fd can interleave with traces in pw.
+            pw.flush();
+            dumpTrafficController(pw, fd, /*verbose=*/ true);
+            pw.decreaseIndent();
+        }
     }
 
     private void dumpNetworks(IndentingPrintWriter pw) {
         for (NetworkAgentInfo nai : networksSortedById()) {
             pw.println(nai.toString());
             pw.increaseIndent();
+            pw.println("Nat464Xlat:");
+            pw.increaseIndent();
+            nai.dumpNat464Xlat(pw);
+            pw.decreaseIndent();
             pw.println(String.format(
                     "Requests: REQUEST:%d LISTEN:%d BACKGROUND_REQUEST:%d total:%d",
                     nai.numForegroundNetworkRequests(),
@@ -3443,10 +3439,6 @@
             pw.increaseIndent();
             nai.dumpInactivityTimers(pw);
             pw.decreaseIndent();
-            pw.println("Nat464Xlat:");
-            pw.increaseIndent();
-            nai.dumpNat464Xlat(pw);
-            pw.decreaseIndent();
             pw.decreaseIndent();
         }
     }
@@ -3872,7 +3864,6 @@
             }
 
             final boolean wasValidated = nai.lastValidated;
-            final boolean wasDefault = isDefaultNetwork(nai);
             final boolean wasPartial = nai.partialConnectivity;
             nai.partialConnectivity = ((testResult & NETWORK_VALIDATION_RESULT_PARTIAL) != 0);
             final boolean partialConnectivityChanged =
@@ -5742,7 +5733,7 @@
 
     @Override
     public void setGlobalProxy(@Nullable final ProxyInfo proxyProperties) {
-        PermissionUtils.enforceNetworkStackPermission(mContext);
+        enforceNetworkStackPermission(mContext);
         mProxyTracker.setGlobalProxy(proxyProperties);
     }
 
@@ -6359,7 +6350,7 @@
             if (null != satisfier) {
                 // If the old NRI was satisfied by an NAI, then it may have had an active request.
                 // The active request is necessary to figure out what callbacks to send, in
-                // particular then a network updates its capabilities.
+                // particular when a network updates its capabilities.
                 // As this code creates a new NRI with a new set of requests, figure out which of
                 // the list of requests should be the active request. It is always the first
                 // request of the list that can be satisfied by the satisfier since the order of
@@ -7290,7 +7281,7 @@
         Objects.requireNonNull(initialScore, "initialScore must not be null");
         Objects.requireNonNull(networkAgentConfig, "networkAgentConfig must not be null");
         if (networkCapabilities.hasTransport(TRANSPORT_TEST)) {
-            enforceAnyPermissionOf(Manifest.permission.MANAGE_TEST_NETWORKS);
+            enforceAnyPermissionOf(mContext, Manifest.permission.MANAGE_TEST_NETWORKS);
         } else {
             enforceNetworkFactoryPermission();
         }
@@ -7767,10 +7758,6 @@
         // when the old rules are removed and the time when new rules are added. To fix this,
         // make eBPF support two allowlisted interfaces so here new rules can be added before the
         // old rules are being removed.
-
-        // Null iface given to onVpnUidRangesAdded/Removed is a wildcard to allow apps to receive
-        // packets on all interfaces. This is required to accept incoming traffic in Lockdown mode
-        // by overriding the Lockdown blocking rule.
         if (wasFiltering) {
             mPermissionMonitor.onVpnUidRangesRemoved(oldIface, ranges, vpnAppUid);
         }
@@ -8096,12 +8083,14 @@
      * Returns whether we need to set interface filtering rule or not
      */
     private boolean requiresVpnAllowRule(NetworkAgentInfo nai, LinkProperties lp,
-            String filterIface) {
-        // Only filter if lp has an interface.
-        if (lp == null || lp.getInterfaceName() == null) return false;
-        // Before T, allow rules are only needed if VPN isolation is enabled.
-        // T and After T, allow rules are needed for all VPNs.
-        return filterIface != null || (nai.isVPN() && SdkLevel.isAtLeastT());
+            String isolationIface) {
+        // Allow rules are always needed if VPN isolation is enabled.
+        if (isolationIface != null) return true;
+
+        // On T and above, allow rules are needed for all VPNs. Allow rule with null iface is a
+        // wildcard to allow apps to receive packets on all interfaces. This is required to accept
+        // incoming traffic in Lockdown mode by overriding the Lockdown blocking rule.
+        return SdkLevel.isAtLeastT() && nai.isVPN() && lp != null && lp.getInterfaceName() != null;
     }
 
     private static UidRangeParcel[] toUidRangeStableParcels(final @NonNull Set<UidRange> ranges) {
@@ -8244,10 +8233,6 @@
             // above, where the addition of new ranges happens before the removal of old ranges.
             // TODO Fix this window by computing an accurate diff on Set<UidRange>, so the old range
             // to be removed will never overlap with the new range to be added.
-
-            // Null iface given to onVpnUidRangesAdded/Removed is a wildcard to allow apps to
-            // receive packets on all interfaces. This is required to accept incoming traffic in
-            // Lockdown mode by overriding the Lockdown blocking rule.
             if (wasFiltering && !prevRanges.isEmpty()) {
                 mPermissionMonitor.onVpnUidRangesRemoved(oldIface, prevRanges,
                         prevNc.getOwnerUid());
@@ -9266,7 +9251,18 @@
             params.networkCapabilities = networkAgent.networkCapabilities;
             params.linkProperties = new LinkProperties(networkAgent.linkProperties,
                     true /* parcelSensitiveFields */);
-            networkAgent.networkMonitor().notifyNetworkConnected(params);
+            // isAtLeastT() is conservative here, as recent versions of NetworkStack support the
+            // newer callback even before T. However getInterfaceVersion is a synchronized binder
+            // call that would cause a Log.wtf to be emitted from the system_server process, and
+            // in the absence of a satisfactory, scalable solution which follows an easy/standard
+            // process to check the interface version, just use an SDK check. NetworkStack will
+            // always be new enough when running on T+.
+            if (SdkLevel.isAtLeastT()) {
+                networkAgent.networkMonitor().notifyNetworkConnected(params);
+            } else {
+                networkAgent.networkMonitor().notifyNetworkConnected(params.linkProperties,
+                        params.networkCapabilities);
+            }
             scheduleUnvalidatedPrompt(networkAgent);
 
             // Whether a particular NetworkRequest listen should cause signal strength thresholds to
@@ -10306,7 +10302,8 @@
         Objects.requireNonNull(network, "network must not be null");
         Objects.requireNonNull(extras, "extras must not be null");
 
-        enforceAnyPermissionOf(android.Manifest.permission.MANAGE_TEST_NETWORKS,
+        enforceAnyPermissionOf(mContext,
+                android.Manifest.permission.MANAGE_TEST_NETWORKS,
                 android.Manifest.permission.NETWORK_STACK);
         final NetworkCapabilities nc = getNetworkCapabilitiesInternal(network);
         if (!nc.hasTransport(TRANSPORT_TEST)) {
@@ -10714,7 +10711,7 @@
             preferences.add(pref);
         }
 
-        PermissionUtils.enforceNetworkStackPermission(mContext);
+        enforceNetworkStackPermission(mContext);
         if (DBG) {
             log("setProfileNetworkPreferences " + profile + " to " + preferences);
         }
@@ -11394,6 +11391,13 @@
     }
 
     @Override
+    public boolean getFirewallChainEnabled(final int chain) {
+        enforceNetworkStackOrSettingsPermission();
+
+        return mBpfNetMaps.isChainEnabled(chain);
+    }
+
+    @Override
     public void replaceFirewallChain(final int chain, final int[] uids) {
         enforceNetworkStackOrSettingsPermission();
 
diff --git a/service/src/com/android/server/TestNetworkService.java b/service/src/com/android/server/TestNetworkService.java
index e12190c..1209579 100644
--- a/service/src/com/android/server/TestNetworkService.java
+++ b/service/src/com/android/server/TestNetworkService.java
@@ -50,6 +50,7 @@
 import com.android.net.module.util.NetdUtils;
 import com.android.net.module.util.NetworkStackConstants;
 
+import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
@@ -76,7 +77,11 @@
     @NonNull private final NetworkProvider mNetworkProvider;
 
     // Native method stubs
-    private static native int jniCreateTunTap(boolean isTun, @NonNull String iface);
+    private static native int nativeCreateTunTap(boolean isTun, boolean hasCarrier,
+            @NonNull String iface);
+
+    private static native void nativeSetTunTapCarrierEnabled(@NonNull String iface, int tunFd,
+            boolean enabled);
 
     @VisibleForTesting
     protected TestNetworkService(@NonNull Context context) {
@@ -114,7 +119,7 @@
      * interface.
      */
     @Override
-    public TestNetworkInterface createInterface(boolean isTun, boolean bringUp,
+    public TestNetworkInterface createInterface(boolean isTun, boolean hasCarrier, boolean bringUp,
             LinkAddress[] linkAddrs, @Nullable String iface) {
         enforceTestNetworkPermissions(mContext);
 
@@ -130,8 +135,8 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            ParcelFileDescriptor tunIntf =
-                    ParcelFileDescriptor.adoptFd(jniCreateTunTap(isTun, interfaceName));
+            ParcelFileDescriptor tunIntf = ParcelFileDescriptor.adoptFd(
+                    nativeCreateTunTap(isTun, hasCarrier, interfaceName));
             for (LinkAddress addr : linkAddrs) {
                 mNetd.interfaceAddAddress(
                         interfaceName,
@@ -375,4 +380,20 @@
     public static void enforceTestNetworkPermissions(@NonNull Context context) {
         context.enforceCallingOrSelfPermission(PERMISSION_NAME, "TestNetworkService");
     }
+
+    /** Enable / disable TestNetworkInterface carrier */
+    @Override
+    public void setCarrierEnabled(@NonNull TestNetworkInterface iface, boolean enabled) {
+        enforceTestNetworkPermissions(mContext);
+        nativeSetTunTapCarrierEnabled(iface.getInterfaceName(), iface.getFileDescriptor().getFd(),
+                enabled);
+        // Explicitly close fd after use to prevent StrictMode from complaining.
+        // Also, explicitly referencing iface guarantees that the object is not garbage collected
+        // before nativeSetTunTapCarrierEnabled() executes.
+        try {
+            iface.getFileDescriptor().close();
+        } catch (IOException e) {
+            // if the close fails, there is not much that can be done -- move on.
+        }
+    }
 }
diff --git a/service/src/com/android/server/UidOwnerValue.java b/service/src/com/android/server/UidOwnerValue.java
new file mode 100644
index 0000000..f89e354
--- /dev/null
+++ b/service/src/com/android/server/UidOwnerValue.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import com.android.net.module.util.Struct;
+
+/** Value type for per uid traffic control configuration map  */
+public class UidOwnerValue extends Struct {
+    // Allowed interface index. Only applicable if IIF_MATCH is set in the rule bitmask below.
+    @Field(order = 0, type = Type.U32)
+    public final long iif;
+
+    // A bitmask of match type.
+    @Field(order = 1, type = Type.U32)
+    public final long rule;
+
+    public UidOwnerValue(final long iif, final long rule) {
+        this.iif = iif;
+        this.rule = rule;
+    }
+}
diff --git a/service/src/com/android/server/connectivity/ClatCoordinator.java b/service/src/com/android/server/connectivity/ClatCoordinator.java
index 4a7c77a..5ea586a 100644
--- a/service/src/com/android/server/connectivity/ClatCoordinator.java
+++ b/service/src/com/android/server/connectivity/ClatCoordinator.java
@@ -347,6 +347,19 @@
                     && this.pid == that.pid
                     && this.cookie == that.cookie;
         }
+
+        @Override
+        public String toString() {
+            return "iface: " + iface
+                    + " (" + ifIndex + ")"
+                    + ", v4iface: " + v4iface
+                    + " (" + v4ifIndex + ")"
+                    + ", v4: " + v4
+                    + ", v6: " + v6
+                    + ", pfx96: " + pfx96
+                    + ", pid: " + pid
+                    + ", cookie: " + cookie;
+        }
     };
 
     @VisibleForTesting
@@ -498,6 +511,31 @@
         }
     }
 
+    private void maybeCleanUp(ParcelFileDescriptor tunFd, ParcelFileDescriptor readSock6,
+            ParcelFileDescriptor writeSock6) {
+        if (tunFd != null) {
+            try {
+                tunFd.close();
+            } catch (IOException e) {
+                Log.e(TAG, "Fail to close tun file descriptor " + e);
+            }
+        }
+        if (readSock6 != null) {
+            try {
+                readSock6.close();
+            } catch (IOException e) {
+                Log.e(TAG, "Fail to close read socket " + e);
+            }
+        }
+        if (writeSock6 != null) {
+            try {
+                writeSock6.close();
+            } catch (IOException e) {
+                Log.e(TAG, "Fail to close write socket " + e);
+            }
+        }
+    }
+
     /**
      * Start clatd for a given interface and NAT64 prefix.
      */
@@ -546,8 +584,15 @@
 
         // [3] Open, configure and bring up the tun interface.
         // Create the v4-... tun interface.
+
+        // Initialize all required file descriptors with null pointer. This makes the following
+        // error handling easier. Simply always call #maybeCleanUp for closing file descriptors,
+        // if any valid ones, in error handling.
+        ParcelFileDescriptor tunFd = null;
+        ParcelFileDescriptor readSock6 = null;
+        ParcelFileDescriptor writeSock6 = null;
+
         final String tunIface = CLAT_PREFIX + iface;
-        final ParcelFileDescriptor tunFd;
         try {
             tunFd = mDeps.adoptFd(mDeps.createTunInterface(tunIface));
         } catch (IOException e) {
@@ -556,7 +601,7 @@
 
         final int tunIfIndex = mDeps.getInterfaceIndex(tunIface);
         if (tunIfIndex == INVALID_IFINDEX) {
-            tunFd.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Fail to get interface index for interface " + tunIface);
         }
 
@@ -564,24 +609,27 @@
         try {
             mNetd.interfaceSetEnableIPv6(tunIface, false /* enabled */);
         } catch (RemoteException | ServiceSpecificException e) {
-            tunFd.close();
             Log.e(TAG, "Disable IPv6 on " + tunIface + " failed: " + e);
         }
 
         // Detect ipv4 mtu.
         final Integer fwmark = getFwmark(netId);
-        final int detectedMtu = mDeps.detectMtu(pfx96Str,
+        final int detectedMtu;
+        try {
+            detectedMtu = mDeps.detectMtu(pfx96Str,
                 ByteBuffer.wrap(GOOGLE_DNS_4.getAddress()).getInt(), fwmark);
+        } catch (IOException e) {
+            maybeCleanUp(tunFd, readSock6, writeSock6);
+            throw new IOException("Detect MTU on " + tunIface + " failed: " + e);
+        }
         final int mtu = adjustMtu(detectedMtu);
         Log.i(TAG, "ipv4 mtu is " + mtu);
 
-        // TODO: add setIptablesDropRule
-
         // Config tun interface mtu, address and bring up.
         try {
             mNetd.interfaceSetMtu(tunIface, mtu);
         } catch (RemoteException | ServiceSpecificException e) {
-            tunFd.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Set MTU " + mtu + " on " + tunIface + " failed: " + e);
         }
         final InterfaceConfigurationParcel ifConfig = new InterfaceConfigurationParcel();
@@ -593,14 +641,13 @@
         try {
             mNetd.interfaceSetCfg(ifConfig);
         } catch (RemoteException | ServiceSpecificException e) {
-            tunFd.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Setting IPv4 address to " + ifConfig.ipv4Addr + "/"
                     + ifConfig.prefixLength + " failed on " + ifConfig.ifName + ": " + e);
         }
 
         // [4] Open and configure local 464xlat read/write sockets.
         // Opens a packet socket to receive IPv6 packets in clatd.
-        final ParcelFileDescriptor readSock6;
         try {
             // Use a JNI call to get native file descriptor instead of Os.socket() because we would
             // like to use ParcelFileDescriptor to manage file descriptor. But ctor
@@ -608,27 +655,23 @@
             // descriptor to initialize ParcelFileDescriptor object instead.
             readSock6 = mDeps.adoptFd(mDeps.openPacketSocket());
         } catch (IOException e) {
-            tunFd.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Open packet socket failed: " + e);
         }
 
         // Opens a raw socket with a given fwmark to send IPv6 packets in clatd.
-        final ParcelFileDescriptor writeSock6;
         try {
             // Use a JNI call to get native file descriptor instead of Os.socket(). See above
             // reason why we use jniOpenPacketSocket6().
             writeSock6 = mDeps.adoptFd(mDeps.openRawSocket6(fwmark));
         } catch (IOException e) {
-            tunFd.close();
-            readSock6.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Open raw socket failed: " + e);
         }
 
         final int ifIndex = mDeps.getInterfaceIndex(iface);
         if (ifIndex == INVALID_IFINDEX) {
-            tunFd.close();
-            readSock6.close();
-            writeSock6.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("Fail to get interface index for interface " + iface);
         }
 
@@ -636,9 +679,7 @@
         try {
             mDeps.addAnycastSetsockopt(writeSock6.getFileDescriptor(), v6Str, ifIndex);
         } catch (IOException e) {
-            tunFd.close();
-            readSock6.close();
-            writeSock6.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("add anycast sockopt failed: " + e);
         }
 
@@ -647,9 +688,7 @@
         try {
             cookie = mDeps.tagSocketAsClat(writeSock6.getFileDescriptor());
         } catch (IOException e) {
-            tunFd.close();
-            readSock6.close();
-            writeSock6.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("tag raw socket failed: " + e);
         }
 
@@ -657,9 +696,7 @@
         try {
             mDeps.configurePacketSocket(readSock6.getFileDescriptor(), v6Str, ifIndex);
         } catch (IOException e) {
-            tunFd.close();
-            readSock6.close();
-            writeSock6.close();
+            maybeCleanUp(tunFd, readSock6, writeSock6);
             throw new IOException("configure packet socket failed: " + e);
         }
 
@@ -673,9 +710,9 @@
             mDeps.untagSocket(cookie);
             throw new IOException("Error start clatd on " + iface + ": " + e);
         } finally {
-            tunFd.close();
-            readSock6.close();
-            writeSock6.close();
+            // The file descriptors have been duplicated (dup2) to clatd in native_startClatd().
+            // Close these file descriptor stubs which are unused anymore.
+            maybeCleanUp(tunFd, readSock6, writeSock6);
         }
 
         // [6] Initialize and store clatd tracker object.
@@ -795,9 +832,9 @@
      * @param pw print writer.
      */
     public void dump(@NonNull IndentingPrintWriter pw) {
-        // TODO: dump ClatdTracker
         // TODO: move map dump to a global place to avoid duplicate dump while there are two or
         // more IPv6 only networks.
+        pw.println("CLAT tracker: " + mClatdTracker.toString());
         pw.println("Forwarding rules:");
         pw.increaseIndent();
         dumpBpfIngress(pw);
diff --git a/service/src/com/android/server/connectivity/Nat464Xlat.java b/service/src/com/android/server/connectivity/Nat464Xlat.java
index e8fc06d..e4ad391 100644
--- a/service/src/com/android/server/connectivity/Nat464Xlat.java
+++ b/service/src/com/android/server/connectivity/Nat464Xlat.java
@@ -17,6 +17,7 @@
 package com.android.server.connectivity;
 
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkCapabilities.TRANSPORT_TEST;
 
 import static com.android.net.module.util.CollectionUtils.contains;
 
@@ -127,6 +128,11 @@
         final boolean supported = contains(NETWORK_TYPES, nai.networkInfo.getType());
         final boolean connected = contains(NETWORK_STATES, nai.networkInfo.getState());
 
+        // Allow to run clat on test network.
+        // TODO: merge to boolean "supported" once boolean "supported" is migrated to
+        // NetworkCapabilities.TRANSPORT_*.
+        final boolean isTestNetwork = nai.networkCapabilities.hasTransport(TRANSPORT_TEST);
+
         // Only run clat on networks that have a global IPv6 address and don't have a native IPv4
         // address.
         LinkProperties lp = nai.linkProperties;
@@ -137,8 +143,8 @@
         final boolean skip464xlat = (nai.netAgentConfig() != null)
                 && nai.netAgentConfig().skip464xlat;
 
-        return supported && connected && isIpv6OnlyNetwork && !skip464xlat && !nai.destroyed
-                && (nai.networkCapabilities.hasTransport(TRANSPORT_CELLULAR)
+        return (supported || isTestNetwork) && connected && isIpv6OnlyNetwork && !skip464xlat
+                && !nai.destroyed && (nai.networkCapabilities.hasTransport(TRANSPORT_CELLULAR)
                 ? isCellular464XlatEnabled() : true);
     }
 
@@ -540,7 +546,7 @@
                 mClatCoordinator.dump(pw);
                 pw.decreaseIndent();
             } else {
-                pw.println("<not start>");
+                pw.println("<not started>");
             }
         }
     }
diff --git a/service/src/com/android/server/connectivity/PermissionMonitor.java b/service/src/com/android/server/connectivity/PermissionMonitor.java
index e4a2c20..fd1ed60 100755
--- a/service/src/com/android/server/connectivity/PermissionMonitor.java
+++ b/service/src/com/android/server/connectivity/PermissionMonitor.java
@@ -23,9 +23,6 @@
 import static android.Manifest.permission.UPDATE_DEVICE_STATS;
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
-import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
-import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.net.ConnectivitySettingsManager.UIDS_ALLOWED_ON_RESTRICTED_NETWORKS;
 import static android.net.INetd.PERMISSION_INTERNET;
 import static android.net.INetd.PERMISSION_NETWORK;
@@ -54,7 +51,6 @@
 import android.net.INetd;
 import android.net.UidRange;
 import android.net.Uri;
-import android.net.util.SharedLog;
 import android.os.Build;
 import android.os.Process;
 import android.os.RemoteException;
@@ -73,6 +69,7 @@
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.CollectionUtils;
+import com.android.net.module.util.SharedLog;
 import com.android.networkstack.apishim.ProcessShimImpl;
 import com.android.networkstack.apishim.common.ProcessShim;
 import com.android.server.BpfNetMaps;
@@ -684,8 +681,12 @@
     }
 
     private synchronized void updateLockdownUid(int uid, boolean add) {
-        if (UidRange.containsUid(mVpnLockdownUidRanges.getSet(), uid)
-                && !hasRestrictedNetworksPermission(uid)) {
+        // Apps that can use restricted networks can always bypass VPNs.
+        if (hasRestrictedNetworksPermission(uid)) {
+            return;
+        }
+
+        if (UidRange.containsUid(mVpnLockdownUidRanges.getSet(), uid)) {
             updateLockdownUidRule(uid, add);
         }
     }
@@ -790,7 +791,7 @@
         mAllApps.add(appId);
 
         // Log package added.
-        mPermissionUpdateLogs.log("Package add: name=" + packageName + ", uid=" + uid
+        mPermissionUpdateLogs.log("Package add: uid=" + uid
                 + ", nPerm=(" + permissionToString(permission) + "/"
                 + permissionToString(currentPermission) + ")"
                 + ", tPerm=" + permissionToString(appIdTrafficPerm));
@@ -843,7 +844,7 @@
         final int permission = highestUidNetworkPermission(uid);
 
         // Log package removed.
-        mPermissionUpdateLogs.log("Package remove: name=" + packageName + ", uid=" + uid
+        mPermissionUpdateLogs.log("Package remove: uid=" + uid
                 + ", nPerm=(" + permissionToString(permission) + "/"
                 + permissionToString(currentPermission) + ")"
                 + ", tPerm=" + permissionToString(appIdTrafficPerm));
@@ -1079,11 +1080,7 @@
 
     private void updateLockdownUidRule(int uid, boolean add) {
         try {
-            if (add) {
-                mBpfNetMaps.setUidRule(FIREWALL_CHAIN_LOCKDOWN_VPN, uid, FIREWALL_RULE_DENY);
-            } else {
-                mBpfNetMaps.setUidRule(FIREWALL_CHAIN_LOCKDOWN_VPN, uid, FIREWALL_RULE_ALLOW);
-            }
+            mBpfNetMaps.updateUidLockdownRule(uid, add);
         } catch (ServiceSpecificException e) {
             loge("Failed to " + (add ? "add" : "remove") + " Lockdown rule: " + e);
         }
@@ -1259,7 +1256,7 @@
         pw.println("Lockdown filtering rules:");
         pw.increaseIndent();
         for (final UidRange range : mVpnLockdownUidRanges.getSet()) {
-            pw.println("UIDs: " + range.toString());
+            pw.println("UIDs: " + range);
         }
         pw.decreaseIndent();
 
diff --git a/service/src/com/android/server/connectivity/QosCallbackAgentConnection.java b/service/src/com/android/server/connectivity/QosCallbackAgentConnection.java
index 534dbe7..e682026 100644
--- a/service/src/com/android/server/connectivity/QosCallbackAgentConnection.java
+++ b/service/src/com/android/server/connectivity/QosCallbackAgentConnection.java
@@ -30,6 +30,8 @@
 import android.telephony.data.NrQosSessionAttributes;
 import android.util.Log;
 
+import com.android.modules.utils.build.SdkLevel;
+
 import java.util.Objects;
 
 /**
@@ -149,6 +151,7 @@
 
     void sendEventEpsQosSessionAvailable(final QosSession session,
             final EpsBearerQosSessionAttributes attributes) {
+        if (!validateOrSendErrorAndUnregister()) return;
         try {
             if (DBG) log("sendEventEpsQosSessionAvailable: sending...");
             mCallback.onQosEpsBearerSessionAvailable(session, attributes);
@@ -159,6 +162,7 @@
 
     void sendEventNrQosSessionAvailable(final QosSession session,
             final NrQosSessionAttributes attributes) {
+        if (!validateOrSendErrorAndUnregister()) return;
         try {
             if (DBG) log("sendEventNrQosSessionAvailable: sending...");
             mCallback.onNrQosSessionAvailable(session, attributes);
@@ -168,6 +172,7 @@
     }
 
     void sendEventQosSessionLost(@NonNull final QosSession session) {
+        if (!validateOrSendErrorAndUnregister()) return;
         try {
             if (DBG) log("sendEventQosSessionLost: sending...");
             mCallback.onQosSessionLost(session);
@@ -185,6 +190,21 @@
         }
     }
 
+    private boolean validateOrSendErrorAndUnregister() {
+        final int exceptionType = mFilter.validate();
+        if (exceptionType != EX_TYPE_FILTER_NONE) {
+             log("validation fail before sending QosCallback.");
+             // Error callback is returned from Android T to prevent any disruption of application
+             // running on Android S.
+             if (SdkLevel.isAtLeastT()) {
+                sendEventQosCallbackError(exceptionType);
+                mQosCallbackTracker.unregisterCallback(mCallback);
+            }
+            return false;
+        }
+        return true;
+    }
+
     private static void log(@NonNull final String msg) {
         Log.d(TAG, msg);
     }
diff --git a/service/src/com/android/server/net/DelayedDiskWrite.java b/service/src/com/android/server/net/DelayedDiskWrite.java
index 35dc455..41cb419 100644
--- a/service/src/com/android/server/net/DelayedDiskWrite.java
+++ b/service/src/com/android/server/net/DelayedDiskWrite.java
@@ -21,6 +21,8 @@
 import android.text.TextUtils;
 import android.util.Log;
 
+import com.android.internal.annotations.VisibleForTesting;
+
 import java.io.BufferedOutputStream;
 import java.io.DataOutputStream;
 import java.io.FileOutputStream;
@@ -32,11 +34,42 @@
 public class DelayedDiskWrite {
     private static final String TAG = "DelayedDiskWrite";
 
+    private final Dependencies mDeps;
+
     private HandlerThread mDiskWriteHandlerThread;
     private Handler mDiskWriteHandler;
     /* Tracks multiple writes on the same thread */
     private int mWriteSequence = 0;
 
+    public DelayedDiskWrite() {
+        this(new Dependencies());
+    }
+
+    @VisibleForTesting
+    DelayedDiskWrite(Dependencies deps) {
+        mDeps = deps;
+    }
+
+    /**
+     * Dependencies class of DelayedDiskWrite, used for injection in tests.
+     */
+    @VisibleForTesting
+    static class Dependencies {
+        /**
+         * Create a HandlerThread to use in DelayedDiskWrite.
+         */
+        public HandlerThread makeHandlerThread() {
+            return new HandlerThread("DelayedDiskWriteThread");
+        }
+
+        /**
+         * Quit the HandlerThread looper.
+         */
+        public void quitHandlerThread(HandlerThread handlerThread) {
+            handlerThread.getLooper().quit();
+        }
+    }
+
     /**
      * Used to do a delayed data write to a given {@link OutputStream}.
      */
@@ -65,7 +98,7 @@
         /* Do a delayed write to disk on a separate handler thread */
         synchronized (this) {
             if (++mWriteSequence == 1) {
-                mDiskWriteHandlerThread = new HandlerThread("DelayedDiskWriteThread");
+                mDiskWriteHandlerThread = mDeps.makeHandlerThread();
                 mDiskWriteHandlerThread.start();
                 mDiskWriteHandler = new Handler(mDiskWriteHandlerThread.getLooper());
             }
@@ -99,9 +132,9 @@
             // Quit if no more writes sent
             synchronized (this) {
                 if (--mWriteSequence == 0) {
-                    mDiskWriteHandler.getLooper().quit();
-                    mDiskWriteHandler = null;
+                    mDeps.quitHandlerThread(mDiskWriteHandlerThread);
                     mDiskWriteHandlerThread = null;
+                    mDiskWriteHandler = null;
                 }
             }
         }
diff --git a/tests/common/java/android/net/EthernetNetworkManagementExceptionTest.java b/tests/common/java/android/net/EthernetNetworkManagementExceptionTest.java
new file mode 100644
index 0000000..84b6e54
--- /dev/null
+++ b/tests/common/java/android/net/EthernetNetworkManagementExceptionTest.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+import static com.android.testutils.ParcelUtils.assertParcelingIsLossless;
+
+import static org.junit.Assert.assertEquals;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2) // TODO: Use to Build.VERSION_CODES.SC_V2 when available
+@RunWith(DevSdkIgnoreRunner.class)
+@SmallTest
+public class EthernetNetworkManagementExceptionTest {
+    private static final String ERROR_MESSAGE = "Test error message";
+
+    @Test
+    public void testEthernetNetworkManagementExceptionParcelable() {
+        final EthernetNetworkManagementException e =
+                new EthernetNetworkManagementException(ERROR_MESSAGE);
+
+        assertParcelingIsLossless(e);
+    }
+
+    @Test
+    public void testEthernetNetworkManagementExceptionHasExpectedErrorMessage() {
+        final EthernetNetworkManagementException e =
+                new EthernetNetworkManagementException(ERROR_MESSAGE);
+
+        assertEquals(ERROR_MESSAGE, e.getMessage());
+    }
+}
diff --git a/tests/common/java/android/net/LinkPropertiesTest.java b/tests/common/java/android/net/LinkPropertiesTest.java
index 9ed2bb3..319dbf4 100644
--- a/tests/common/java/android/net/LinkPropertiesTest.java
+++ b/tests/common/java/android/net/LinkPropertiesTest.java
@@ -1312,7 +1312,26 @@
         assertEquals(3, lp.getRoutes().size());
     }
 
-    @Test @IgnoreUpTo(Build.VERSION_CODES.R)
+    @Test @IgnoreUpTo(Build.VERSION_CODES.R) @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    @CtsNetTestCasesMaxTargetSdk31(reason = "Compat change cannot be overridden when targeting T+")
+    @DisableCompatChanges({LinkProperties.EXCLUDED_ROUTES})
+    public void testExcludedRoutesDisabled_S() {
+        final LinkProperties lp = new LinkProperties();
+        assertEquals(0, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV4, 0), RTN_UNREACHABLE));
+        assertEquals(1, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 5), RTN_THROW));
+        // RTN_THROW routes are visible on S when added by the caller (but they are not added by
+        // the system). This is uncommon usage but was tested by CTSv12.
+        assertEquals(2, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 2), RTN_UNICAST));
+        assertEquals(3, lp.getRoutes().size());
+    }
+
+    @Test @IgnoreUpTo(Build.VERSION_CODES.S_V2)
     @CtsNetTestCasesMaxTargetSdk31(reason = "Compat change cannot be overridden when targeting T+")
     @DisableCompatChanges({LinkProperties.EXCLUDED_ROUTES})
     public void testExcludedRoutesDisabled() {
@@ -1320,12 +1339,12 @@
         assertEquals(0, lp.getRoutes().size());
 
         lp.addRoute(new RouteInfo(new IpPrefix(ADDRV4, 0), RTN_UNREACHABLE));
-        assertEquals(0, lp.getRoutes().size());
+        assertEquals(1, lp.getRoutes().size());
 
         lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 5), RTN_THROW));
-        assertEquals(0, lp.getRoutes().size());
+        assertEquals(1, lp.getRoutes().size());
 
         lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 2), RTN_UNICAST));
-        assertEquals(1, lp.getRoutes().size());
+        assertEquals(2, lp.getRoutes().size());
     }
 }
diff --git a/tests/cts/hostside/Android.bp b/tests/cts/hostside/Android.bp
index c47ccbf..ac84e57 100644
--- a/tests/cts/hostside/Android.bp
+++ b/tests/cts/hostside/Android.bp
@@ -35,4 +35,12 @@
         "general-tests",
         "sts"
     ],
+    data: [
+        ":CtsHostsideNetworkTestsApp",
+        ":CtsHostsideNetworkTestsApp2",
+        ":CtsHostsideNetworkTestsApp3",
+        ":CtsHostsideNetworkTestsApp3PreT",
+        ":CtsHostsideNetworkTestsAppNext",
+    ],
+    per_testcase_directory: true,
 }
diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/VpnTest.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/VpnTest.java
index dc67c70..dd8b523 100755
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/VpnTest.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/VpnTest.java
@@ -378,10 +378,6 @@
         if (mNetwork == null) {
             fail("VPN did not become available after " + TIMEOUT_MS + "ms");
         }
-
-        // Unfortunately, when the available callback fires, the VPN UID ranges are not yet
-        // configured. Give the system some time to do so. http://b/18436087 .
-        try { Thread.sleep(3000); } catch(InterruptedException e) {}
     }
 
     private void stopVpn() {
diff --git a/tests/cts/hostside/app3/Android.bp b/tests/cts/hostside/app3/Android.bp
index 69667ce..141cf03 100644
--- a/tests/cts/hostside/app3/Android.bp
+++ b/tests/cts/hostside/app3/Android.bp
@@ -14,6 +14,10 @@
 // limitations under the License.
 //
 
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
 java_defaults {
     name: "CtsHostsideNetworkTestsApp3Defaults",
     srcs: ["src/**/*.java"],
diff --git a/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkTestCase.java b/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkTestCase.java
index cc07fd1..d0567ae 100644
--- a/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkTestCase.java
+++ b/tests/cts/hostside/src/com/android/cts/net/HostsideNetworkTestCase.java
@@ -34,8 +34,6 @@
 
 import java.io.FileNotFoundException;
 import java.util.Map;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
 abstract class HostsideNetworkTestCase extends DeviceTestCase implements IAbiReceiver,
         IBuildReceiver {
@@ -171,18 +169,19 @@
         }
     }
 
-    private static final Pattern UID_PATTERN =
-            Pattern.compile(".*userId=([0-9]+)$", Pattern.MULTILINE);
-
     protected int getUid(String packageName) throws DeviceNotAvailableException {
-        final String output = runCommand("dumpsys package " + packageName);
-        final Matcher matcher = UID_PATTERN.matcher(output);
-        while (matcher.find()) {
-            final String match = matcher.group(1);
-            return Integer.parseInt(match);
+        final int currentUser = getDevice().getCurrentUser();
+        final String uidLines = runCommand(
+                "cmd package list packages -U --user " + currentUser + " " + packageName);
+        for (String uidLine : uidLines.split("\n")) {
+            if (uidLine.startsWith("package:" + packageName + " uid:")) {
+                final String[] uidLineParts = uidLine.split(":");
+                // 3rd entry is package uid
+                return Integer.parseInt(uidLineParts[2].trim());
+            }
         }
-        throw new RuntimeException("Did not find regexp '" + UID_PATTERN + "' on adb output\n"
-                + output);
+        throw new IllegalStateException("Failed to find the test app on the device; pkg="
+                + packageName + ", u=" + currentUser);
     }
 
     protected String runCommand(String command) throws DeviceNotAvailableException {
diff --git a/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt b/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
index 0344604..1b77d5f 100644
--- a/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
+++ b/tests/cts/net/src/android/net/cts/CaptivePortalTest.kt
@@ -33,7 +33,6 @@
 import android.net.NetworkCapabilities.TRANSPORT_WIFI
 import android.net.NetworkRequest
 import android.net.Uri
-import android.net.cts.NetworkValidationTestUtil.clearValidationTestUrlsDeviceConfig
 import android.net.cts.NetworkValidationTestUtil.setHttpUrlDeviceConfig
 import android.net.cts.NetworkValidationTestUtil.setHttpsUrlDeviceConfig
 import android.net.cts.NetworkValidationTestUtil.setUrlExpirationDeviceConfig
@@ -60,6 +59,8 @@
 import org.junit.Assume.assumeTrue
 import org.junit.Assume.assumeFalse
 import org.junit.Before
+import org.junit.BeforeClass
+import org.junit.Rule
 import org.junit.runner.RunWith
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.TimeUnit
@@ -99,34 +100,42 @@
 
     private val server = TestHttpServer("localhost")
 
+    @get:Rule
+    val deviceConfigRule = DeviceConfigRule(retryCountBeforeSIfConfigChanged = 5)
+
+    companion object {
+        @JvmStatic @BeforeClass
+        fun setUpClass() {
+            runAsShell(READ_DEVICE_CONFIG) {
+                // Verify that the test URLs are not normally set on the device, but do not fail if
+                // the test URLs are set to what this test uses (URLs on localhost), in case the
+                // test was interrupted manually and rerun.
+                assertEmptyOrLocalhostUrl(TEST_CAPTIVE_PORTAL_HTTPS_URL)
+                assertEmptyOrLocalhostUrl(TEST_CAPTIVE_PORTAL_HTTP_URL)
+            }
+            NetworkValidationTestUtil.clearValidationTestUrlsDeviceConfig()
+        }
+
+        private fun assertEmptyOrLocalhostUrl(urlKey: String) {
+            val url = DeviceConfig.getProperty(NAMESPACE_CONNECTIVITY, urlKey)
+            assertTrue(TextUtils.isEmpty(url) || LOCALHOST_HOSTNAME == Uri.parse(url).host,
+                    "$urlKey must not be set in production scenarios (current value: $url)")
+        }
+    }
+
     @Before
     fun setUp() {
-        runAsShell(READ_DEVICE_CONFIG) {
-            // Verify that the test URLs are not normally set on the device, but do not fail if the
-            // test URLs are set to what this test uses (URLs on localhost), in case the test was
-            // interrupted manually and rerun.
-            assertEmptyOrLocalhostUrl(TEST_CAPTIVE_PORTAL_HTTPS_URL)
-            assertEmptyOrLocalhostUrl(TEST_CAPTIVE_PORTAL_HTTP_URL)
-        }
-        clearValidationTestUrlsDeviceConfig()
         server.start()
     }
 
     @After
     fun tearDown() {
-        clearValidationTestUrlsDeviceConfig()
         if (pm.hasSystemFeature(FEATURE_WIFI)) {
-            reconnectWifi()
+            deviceConfigRule.runAfterNextCleanup { reconnectWifi() }
         }
         server.stop()
     }
 
-    private fun assertEmptyOrLocalhostUrl(urlKey: String) {
-        val url = DeviceConfig.getProperty(NAMESPACE_CONNECTIVITY, urlKey)
-        assertTrue(TextUtils.isEmpty(url) || LOCALHOST_HOSTNAME == Uri.parse(url).host,
-                "$urlKey must not be set in production scenarios (current value: $url)")
-    }
-
     @Test
     fun testCaptivePortalIsNotDefaultNetwork() {
         assumeTrue(pm.hasSystemFeature(FEATURE_TELEPHONY))
@@ -154,12 +163,13 @@
         server.addResponse(Request(TEST_HTTPS_URL_PATH), Status.INTERNAL_ERROR)
         val headers = mapOf("Location" to makeUrl(TEST_PORTAL_URL_PATH))
         server.addResponse(Request(TEST_HTTP_URL_PATH), Status.REDIRECT, headers)
-        setHttpsUrlDeviceConfig(makeUrl(TEST_HTTPS_URL_PATH))
-        setHttpUrlDeviceConfig(makeUrl(TEST_HTTP_URL_PATH))
+        setHttpsUrlDeviceConfig(deviceConfigRule, makeUrl(TEST_HTTPS_URL_PATH))
+        setHttpUrlDeviceConfig(deviceConfigRule, makeUrl(TEST_HTTP_URL_PATH))
         Log.d(TAG, "Set portal URLs to $TEST_HTTPS_URL_PATH and $TEST_HTTP_URL_PATH")
         // URL expiration needs to be in the next 10 minutes
         assertTrue(WIFI_CONNECT_TIMEOUT_MS < TimeUnit.MINUTES.toMillis(10))
-        setUrlExpirationDeviceConfig(System.currentTimeMillis() + WIFI_CONNECT_TIMEOUT_MS)
+        setUrlExpirationDeviceConfig(deviceConfigRule,
+                System.currentTimeMillis() + WIFI_CONNECT_TIMEOUT_MS)
 
         // Wait for a captive portal to be detected on the network
         val wifiNetworkFuture = CompletableFuture<Network>()
@@ -215,4 +225,4 @@
         utils.ensureWifiDisconnected(null /* wifiNetworkToCheck */)
         utils.ensureWifiConnected()
     }
-}
\ No newline at end of file
+}
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index 0cd3490..766d62f 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -170,7 +170,6 @@
 import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.Log;
-import android.util.Pair;
 import android.util.Range;
 
 import androidx.test.InstrumentationRegistry;
@@ -188,6 +187,7 @@
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.DevSdkIgnoreRuleKt;
+import com.android.testutils.DeviceInfoUtils;
 import com.android.testutils.DumpTestUtils;
 import com.android.testutils.RecorderCallback.CallbackEntry;
 import com.android.testutils.TestHttpServer;
@@ -200,7 +200,6 @@
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -250,6 +249,10 @@
     @Rule
     public final DevSdkIgnoreRule ignoreRule = new DevSdkIgnoreRule();
 
+    @Rule
+    public final DeviceConfigRule mTestValidationConfigRule = new DeviceConfigRule(
+            5 /* retryCountBeforeSIfConfigChanged */);
+
     private static final String TAG = ConnectivityManagerTest.class.getSimpleName();
 
     public static final int TYPE_MOBILE = ConnectivityManager.TYPE_MOBILE;
@@ -1616,51 +1619,7 @@
 
     private static boolean isTcpKeepaliveSupportedByKernel() {
         final String kVersionString = VintfRuntimeInfo.getKernelVersion();
-        return compareMajorMinorVersion(kVersionString, "4.8") >= 0;
-    }
-
-    private static Pair<Integer, Integer> getVersionFromString(String version) {
-        // Only gets major and minor number of the version string.
-        final Pattern versionPattern = Pattern.compile("^(\\d+)(\\.(\\d+))?.*");
-        final Matcher m = versionPattern.matcher(version);
-        if (m.matches()) {
-            final int major = Integer.parseInt(m.group(1));
-            final int minor = TextUtils.isEmpty(m.group(3)) ? 0 : Integer.parseInt(m.group(3));
-            return new Pair<>(major, minor);
-        } else {
-            return new Pair<>(0, 0);
-        }
-    }
-
-    // TODO: Move to util class.
-    private static int compareMajorMinorVersion(final String s1, final String s2) {
-        final Pair<Integer, Integer> v1 = getVersionFromString(s1);
-        final Pair<Integer, Integer> v2 = getVersionFromString(s2);
-
-        if (v1.first == v2.first) {
-            return Integer.compare(v1.second, v2.second);
-        } else {
-            return Integer.compare(v1.first, v2.first);
-        }
-    }
-
-    /**
-     * Verifies that version string compare logic returns expected result for various cases.
-     * Note that only major and minor number are compared.
-     */
-    @Test
-    public void testMajorMinorVersionCompare() {
-        assertEquals(0, compareMajorMinorVersion("4.8.1", "4.8"));
-        assertEquals(1, compareMajorMinorVersion("4.9", "4.8.1"));
-        assertEquals(1, compareMajorMinorVersion("5.0", "4.8"));
-        assertEquals(1, compareMajorMinorVersion("5", "4.8"));
-        assertEquals(0, compareMajorMinorVersion("5", "5.0"));
-        assertEquals(1, compareMajorMinorVersion("5-beta1", "4.8"));
-        assertEquals(0, compareMajorMinorVersion("4.8.0.0", "4.8"));
-        assertEquals(0, compareMajorMinorVersion("4.8-RC1", "4.8"));
-        assertEquals(0, compareMajorMinorVersion("4.8", "4.8"));
-        assertEquals(-1, compareMajorMinorVersion("3.10", "4.8.0"));
-        assertEquals(-1, compareMajorMinorVersion("4.7.10.10", "4.8"));
+        return DeviceInfoUtils.compareMajorMinorVersion(kVersionString, "4.8") >= 0;
     }
 
     /**
@@ -2810,9 +2769,8 @@
             // Accept partial connectivity network should result in a validated network
             expectNetworkHasCapability(network, NET_CAPABILITY_VALIDATED, WIFI_CONNECT_TIMEOUT_MS);
         } finally {
-            resetValidationConfig();
-            // Reconnect wifi to reset the wifi status
-            reconnectWifi();
+            mHttpServer.stop();
+            mTestValidationConfigRule.runAfterNextCleanup(this::reconnectWifi);
         }
     }
 
@@ -2837,11 +2795,13 @@
             // Reject partial connectivity network should cause the network being torn down
             assertEquals(network, cb.waitForLost());
         } finally {
-            resetValidationConfig();
+            mHttpServer.stop();
             // Wifi will not automatically reconnect to the network. ensureWifiDisconnected cannot
             // apply here. Thus, turn off wifi first and restart to restore.
-            runShellCommand("svc wifi disable");
-            mCtsNetUtils.ensureWifiConnected();
+            mTestValidationConfigRule.runAfterNextCleanup(() -> {
+                runShellCommand("svc wifi disable");
+                mCtsNetUtils.ensureWifiConnected();
+            });
         }
     }
 
@@ -2877,11 +2837,13 @@
             });
             waitForLost(wifiCb);
         } finally {
-            resetValidationConfig();
+            mHttpServer.stop();
             /// Wifi will not automatically reconnect to the network. ensureWifiDisconnected cannot
             // apply here. Thus, turn off wifi first and restart to restore.
-            runShellCommand("svc wifi disable");
-            mCtsNetUtils.ensureWifiConnected();
+            mTestValidationConfigRule.runAfterNextCleanup(() -> {
+                runShellCommand("svc wifi disable");
+                mCtsNetUtils.ensureWifiConnected();
+            });
         }
     }
 
@@ -2941,9 +2903,8 @@
             wifiCb.assertNoCallbackThat(NO_CALLBACK_TIMEOUT_MS, c -> isValidatedCaps(c));
         } finally {
             resetAvoidBadWifi(previousAvoidBadWifi);
-            resetValidationConfig();
-            // Reconnect wifi to reset the wifi status
-            reconnectWifi();
+            mHttpServer.stop();
+            mTestValidationConfigRule.runAfterNextCleanup(this::reconnectWifi);
         }
     }
 
@@ -2987,11 +2948,6 @@
         return future.get(timeout, TimeUnit.MILLISECONDS);
     }
 
-    private void resetValidationConfig() {
-        NetworkValidationTestUtil.clearValidationTestUrlsDeviceConfig();
-        mHttpServer.stop();
-    }
-
     private void prepareHttpServer() throws Exception {
         runAsShell(READ_DEVICE_CONFIG, () -> {
             // Verify that the test URLs are not normally set on the device, but do not fail if the
@@ -3064,9 +3020,11 @@
         mHttpServer.addResponse(new TestHttpServer.Request(
                 TEST_HTTP_URL_PATH, Method.GET, "" /* queryParameters */),
                 httpStatusCode, null /* locationHeader */, "" /* content */);
-        NetworkValidationTestUtil.setHttpsUrlDeviceConfig(makeUrl(TEST_HTTPS_URL_PATH));
-        NetworkValidationTestUtil.setHttpUrlDeviceConfig(makeUrl(TEST_HTTP_URL_PATH));
-        NetworkValidationTestUtil.setUrlExpirationDeviceConfig(
+        NetworkValidationTestUtil.setHttpsUrlDeviceConfig(mTestValidationConfigRule,
+                makeUrl(TEST_HTTPS_URL_PATH));
+        NetworkValidationTestUtil.setHttpUrlDeviceConfig(mTestValidationConfigRule,
+                makeUrl(TEST_HTTP_URL_PATH));
+        NetworkValidationTestUtil.setUrlExpirationDeviceConfig(mTestValidationConfigRule,
                 System.currentTimeMillis() + WIFI_CONNECT_TIMEOUT_MS);
     }
 
@@ -3418,7 +3376,6 @@
         }, NETWORK_SETTINGS);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test @IgnoreUpTo(SC_V2)
     @AppModeFull(reason = "Socket cannot bind in instant app mode")
     public void testFirewallBlocking() {
diff --git a/tests/cts/net/src/android/net/cts/DeviceConfigRule.kt b/tests/cts/net/src/android/net/cts/DeviceConfigRule.kt
new file mode 100644
index 0000000..d31a4e0
--- /dev/null
+++ b/tests/cts/net/src/android/net/cts/DeviceConfigRule.kt
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net.cts
+
+import android.Manifest.permission.READ_DEVICE_CONFIG
+import android.Manifest.permission.WRITE_DEVICE_CONFIG
+import android.provider.DeviceConfig
+import android.util.Log
+import com.android.modules.utils.build.SdkLevel
+import com.android.testutils.runAsShell
+import com.android.testutils.tryTest
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+
+private val TAG = DeviceConfigRule::class.simpleName
+
+/**
+ * A [TestRule] that helps set [DeviceConfig] for tests and clean up the test configuration
+ * automatically on teardown.
+ *
+ * The rule can also optionally retry tests when they fail following an external change of
+ * DeviceConfig before S; this typically happens because device config flags are synced while the
+ * test is running, and DisableConfigSyncTargetPreparer is only usable starting from S.
+ *
+ * @param retryCountBeforeSIfConfigChanged if > 0, when the test fails before S, check if
+ *        the configs that were set through this rule were changed, and retry the test
+ *        up to the specified number of times if yes.
+ */
+class DeviceConfigRule @JvmOverloads constructor(
+    val retryCountBeforeSIfConfigChanged: Int = 0
+) : TestRule {
+    // Maps (namespace, key) -> value
+    private val originalConfig = mutableMapOf<Pair<String, String>, String?>()
+    private val usedConfig = mutableMapOf<Pair<String, String>, String?>()
+
+    /**
+     * Actions to be run after cleanup of the config, for the current test only.
+     */
+    private val currentTestCleanupActions = mutableListOf<Runnable>()
+
+    override fun apply(base: Statement, description: Description): Statement {
+        return TestValidationUrlStatement(base, description)
+    }
+
+    private inner class TestValidationUrlStatement(
+        private val base: Statement,
+        private val description: Description
+    ) : Statement() {
+        override fun evaluate() {
+            var retryCount = if (SdkLevel.isAtLeastS()) 1 else retryCountBeforeSIfConfigChanged + 1
+            while (retryCount > 0) {
+                retryCount--
+                tryTest {
+                    base.evaluate()
+                    // Can't use break/return out of a loop here because this is a tryTest lambda,
+                    // so set retryCount to exit instead
+                    retryCount = 0
+                }.catch<Throwable> { e -> // junit AssertionFailedError does not extend Exception
+                    if (retryCount == 0) throw e
+                    usedConfig.forEach { (key, value) ->
+                        val currentValue = runAsShell(READ_DEVICE_CONFIG) {
+                            DeviceConfig.getProperty(key.first, key.second)
+                        }
+                        if (currentValue != value) {
+                            Log.w(TAG, "Test failed with unexpected device config change, retrying")
+                            return@catch
+                        }
+                    }
+                    throw e
+                } cleanupStep {
+                    runAsShell(WRITE_DEVICE_CONFIG) {
+                        originalConfig.forEach { (key, value) ->
+                            DeviceConfig.setProperty(
+                                    key.first, key.second, value, false /* makeDefault */)
+                        }
+                    }
+                } cleanupStep {
+                    originalConfig.clear()
+                    usedConfig.clear()
+                } cleanup {
+                    currentTestCleanupActions.forEach { it.run() }
+                    currentTestCleanupActions.clear()
+                }
+            }
+        }
+    }
+
+    /**
+     * Set a configuration key/value. After the test case ends, it will be restored to the value it
+     * had when this method was first called.
+     */
+    fun setConfig(namespace: String, key: String, value: String?) {
+        runAsShell(READ_DEVICE_CONFIG, WRITE_DEVICE_CONFIG) {
+            val keyPair = Pair(namespace, key)
+            if (!originalConfig.containsKey(keyPair)) {
+                originalConfig[keyPair] = DeviceConfig.getProperty(namespace, key)
+            }
+            usedConfig[keyPair] = value
+            DeviceConfig.setProperty(namespace, key, value, false /* makeDefault */)
+        }
+    }
+
+    /**
+     * Add an action to be run after config cleanup when the current test case ends.
+     */
+    fun runAfterNextCleanup(action: Runnable) {
+        currentTestCleanupActions.add(action)
+    }
+}
diff --git a/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt b/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
index bbac09b..621b743 100644
--- a/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
+++ b/tests/cts/net/src/android/net/cts/DscpPolicyTest.kt
@@ -136,8 +136,8 @@
 
     @Before
     fun setUp() {
-        // For BPF support kernel needs to be at least 5.4.
-        assumeTrue(kernelIsAtLeast(5, 4))
+        // For BPF support kernel needs to be at least 5.15.
+        assumeTrue(kernelIsAtLeast(5, 15))
 
         runAsShell(MANAGE_TEST_NETWORKS) {
             val tnm = realContext.getSystemService(TestNetworkManager::class.java)
@@ -158,7 +158,7 @@
 
     @After
     fun tearDown() {
-        if (!kernelIsAtLeast(5, 4)) {
+        if (!kernelIsAtLeast(5, 15)) {
             return;
         }
         agentsToCleanUp.forEach { it.unregister() }
diff --git a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
index a694f01..1748612 100644
--- a/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
+++ b/tests/cts/net/src/android/net/cts/EthernetManagerTest.kt
@@ -30,11 +30,14 @@
 import android.net.EthernetManager.STATE_LINK_UP
 import android.net.EthernetManager.TetheredInterfaceCallback
 import android.net.EthernetManager.TetheredInterfaceRequest
+import android.net.EthernetNetworkManagementException
 import android.net.EthernetNetworkSpecifier
+import android.net.EthernetNetworkUpdateRequest
 import android.net.InetAddresses
 import android.net.IpConfiguration
 import android.net.MacAddress
 import android.net.Network
+import android.net.NetworkCapabilities
 import android.net.NetworkCapabilities.NET_CAPABILITY_TRUSTED
 import android.net.NetworkCapabilities.TRANSPORT_ETHERNET
 import android.net.NetworkCapabilities.TRANSPORT_TEST
@@ -44,15 +47,16 @@
 import android.net.cts.EthernetManagerTest.EthernetStateListener.CallbackEntry.InterfaceStateChanged
 import android.os.Build
 import android.os.Handler
-import android.os.HandlerExecutor
 import android.os.Looper
-import android.os.SystemProperties
+import android.os.OutcomeReceiver
 import android.platform.test.annotations.AppModeFull
 import android.util.ArraySet
 import androidx.test.platform.app.InstrumentationRegistry
 import com.android.net.module.util.ArrayTrackRecord
 import com.android.net.module.util.TrackRecord
 import com.android.testutils.anyNetwork
+import com.android.testutils.ConnectivityModuleTest
+import com.android.testutils.DeviceInfoUtils.isKernelVersionAtLeast
 import com.android.testutils.DevSdkIgnoreRule
 import com.android.testutils.DevSdkIgnoreRunner
 import com.android.testutils.RecorderCallback.CallbackEntry.Available
@@ -63,14 +67,14 @@
 import com.android.testutils.runAsShell
 import com.android.testutils.waitForIdle
 import org.junit.After
-import org.junit.Assume.assumeFalse
+import org.junit.Assume.assumeTrue
 import org.junit.Before
-import org.junit.Ignore
 import org.junit.Test
 import org.junit.runner.RunWith
 import java.net.Inet6Address
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.ExecutionException
+import java.util.concurrent.TimeoutException
 import java.util.concurrent.TimeUnit
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
@@ -95,35 +99,42 @@
 @AppModeFull(reason = "Instant apps can't access EthernetManager")
 // EthernetManager is not updatable before T, so tests do not need to be backwards compatible.
 @RunWith(DevSdkIgnoreRunner::class)
+// This test depends on behavior introduced post-T as part of connectivity module updates
+@ConnectivityModuleTest
 @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 class EthernetManagerTest {
 
     private val context by lazy { InstrumentationRegistry.getInstrumentation().context }
     private val em by lazy { context.getSystemService(EthernetManager::class.java) }
     private val cm by lazy { context.getSystemService(ConnectivityManager::class.java) }
+    private val handler by lazy { Handler(Looper.getMainLooper()) }
 
     private val ifaceListener = EthernetStateListener()
     private val createdIfaces = ArrayList<EthernetTestInterface>()
     private val addedListeners = ArrayList<EthernetStateListener>()
-    private val networkRequests = ArrayList<TestableNetworkCallback>()
+    private val registeredCallbacks = ArrayList<TestableNetworkCallback>()
 
     private var tetheredInterfaceRequest: TetheredInterfaceRequest? = null
 
     private class EthernetTestInterface(
         context: Context,
-        private val handler: Handler
+        private val handler: Handler,
+        hasCarrier: Boolean
     ) {
         private val tapInterface: TestNetworkInterface
         private val packetReader: TapPacketReader
         private val raResponder: RouterAdvertisementResponder
-        val interfaceName get() = tapInterface.interfaceName
+        private val tnm: TestNetworkManager
+        val name get() = tapInterface.interfaceName
 
         init {
-            tapInterface = runAsShell(MANAGE_TEST_NETWORKS) {
-                val tnm = context.getSystemService(TestNetworkManager::class.java)
-                tnm.createTapInterface(false /* bringUp */)
+            tnm = runAsShell(MANAGE_TEST_NETWORKS) {
+                context.getSystemService(TestNetworkManager::class.java)
             }
-            val mtu = 1500
+            tapInterface = runAsShell(MANAGE_TEST_NETWORKS) {
+                tnm.createTapInterface(hasCarrier, false /* bringUp */)
+            }
+            val mtu = tapInterface.mtu
             packetReader = TapPacketReader(handler, tapInterface.fileDescriptor.fileDescriptor, mtu)
             raResponder = RouterAdvertisementResponder(packetReader)
             raResponder.addRouterEntry(MacAddress.fromString("01:23:45:67:89:ab"),
@@ -133,6 +144,14 @@
             raResponder.start()
         }
 
+        // WARNING: this function requires kernel support. Call assumeChangingCarrierSupported() at
+        // the top of your test.
+        fun setCarrierEnabled(enabled: Boolean) {
+            runAsShell(MANAGE_TEST_NETWORKS) {
+                tnm.setCarrierEnabled(tapInterface, enabled)
+            }
+        }
+
         fun destroy() {
             raResponder.stop()
             handler.post({ packetReader.stop() })
@@ -173,7 +192,7 @@
         }
 
         fun expectCallback(iface: EthernetTestInterface, state: Int, role: Int) {
-            expectCallback(createChangeEvent(iface.interfaceName, state, role))
+            expectCallback(createChangeEvent(iface.name, state, role))
         }
 
         fun createChangeEvent(iface: String, state: Int, role: Int) =
@@ -186,12 +205,8 @@
 
         fun eventuallyExpect(expected: CallbackEntry) = events.poll(TIMEOUT_MS) { it == expected }
 
-        fun eventuallyExpect(interfaceName: String, state: Int, role: Int) {
-            assertNotNull(eventuallyExpect(createChangeEvent(interfaceName, state, role)))
-        }
-
         fun eventuallyExpect(iface: EthernetTestInterface, state: Int, role: Int) {
-            eventuallyExpect(iface.interfaceName, state, role)
+            assertNotNull(eventuallyExpect(createChangeEvent(iface.name, state, role)))
         }
 
         fun assertNoCallback() {
@@ -228,6 +243,35 @@
         }
     }
 
+    private class EthernetOutcomeReceiver :
+        OutcomeReceiver<String, EthernetNetworkManagementException> {
+        private val result = CompletableFuture<String>()
+
+        override fun onResult(iface: String) {
+            result.complete(iface)
+        }
+
+        override fun onError(e: EthernetNetworkManagementException) {
+            result.completeExceptionally(e)
+        }
+
+        fun expectResult(expected: String) {
+            assertEquals(expected, result.get(TIMEOUT_MS, TimeUnit.MILLISECONDS))
+        }
+
+        fun expectError() {
+            // Assert that the future fails with EthernetNetworkManagementException from the
+            // completeExceptionally() call inside onUnavailable.
+            assertFailsWith(EthernetNetworkManagementException::class) {
+                try {
+                    result.get()
+                } catch (e: ExecutionException) {
+                    throw e.cause!!
+                }
+            }
+        }
+    }
+
     @Before
     fun setUp() {
         setIncludeTestInterfaces(true)
@@ -244,26 +288,33 @@
         for (listener in addedListeners) {
             em.removeInterfaceStateListener(listener)
         }
-        networkRequests.forEach { cm.unregisterNetworkCallback(it) }
+        registeredCallbacks.forEach { cm.unregisterNetworkCallback(it) }
         releaseTetheredInterface()
     }
 
+    // Setting the carrier up / down relies on TUNSETCARRIER which was added in kernel version 5.0.
+    private fun assumeChangingCarrierSupported() = assumeTrue(isKernelVersionAtLeast("5.0.0"))
+
     private fun addInterfaceStateListener(listener: EthernetStateListener) {
         runAsShell(CONNECTIVITY_USE_RESTRICTED_NETWORKS) {
-            em.addInterfaceStateListener(HandlerExecutor(Handler(Looper.getMainLooper())), listener)
+            em.addInterfaceStateListener(handler::post, listener)
         }
         addedListeners.add(listener)
     }
 
-    private fun createInterface(): EthernetTestInterface {
+    // WARNING: setting hasCarrier to false requires kernel support. Call
+    // assumeChangingCarrierSupported() at the top of your test.
+    private fun createInterface(hasCarrier: Boolean = true): EthernetTestInterface {
         val iface = EthernetTestInterface(
             context,
-            Handler(Looper.getMainLooper())
+            handler,
+            hasCarrier
         ).also { createdIfaces.add(it) }
-        with(ifaceListener) {
-            // when an interface comes up, we should always see a down cb before an up cb.
-            eventuallyExpect(iface, STATE_LINK_DOWN, ROLE_CLIENT)
-            expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
+
+        // when an interface comes up, we should always see a down cb before an up cb.
+        ifaceListener.eventuallyExpect(iface, STATE_LINK_DOWN, ROLE_CLIENT)
+        if (hasCarrier) {
+            ifaceListener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
         }
         return iface
     }
@@ -283,18 +334,20 @@
     private fun requestNetwork(request: NetworkRequest): TestableNetworkCallback {
         return TestableNetworkCallback().also {
             cm.requestNetwork(request, it)
-            networkRequests.add(it)
+            registeredCallbacks.add(it)
         }
     }
 
-    private fun releaseNetwork(cb: TestableNetworkCallback) {
-        cm.unregisterNetworkCallback(cb)
-        networkRequests.remove(cb)
+    private fun registerNetworkListener(request: NetworkRequest): TestableNetworkCallback {
+        return TestableNetworkCallback().also {
+            cm.registerNetworkCallback(request, it)
+            registeredCallbacks.add(it)
+        }
     }
 
     private fun requestTetheredInterface() = TetheredInterfaceListener().also {
         tetheredInterfaceRequest = runAsShell(NETWORK_SETTINGS) {
-            em.requestTetheredInterface(HandlerExecutor(Handler(Looper.getMainLooper())), it)
+            em.requestTetheredInterface(handler::post, it)
         }
     }
 
@@ -305,23 +358,65 @@
         }
     }
 
+    private fun releaseRequest(cb: TestableNetworkCallback) {
+        cm.unregisterNetworkCallback(cb)
+        registeredCallbacks.remove(cb)
+    }
+
+    private fun disableInterface(iface: EthernetTestInterface) = EthernetOutcomeReceiver().also {
+        runAsShell(MANAGE_TEST_NETWORKS) {
+            em.disableInterface(iface.name, handler::post, it)
+        }
+    }
+
+    private fun enableInterface(iface: EthernetTestInterface) = EthernetOutcomeReceiver().also {
+        runAsShell(MANAGE_TEST_NETWORKS) {
+            em.enableInterface(iface.name, handler::post, it)
+        }
+    }
+
+    private fun updateConfiguration(
+        iface: EthernetTestInterface,
+        ipConfig: IpConfiguration? = null,
+        capabilities: NetworkCapabilities? = null
+    ) = EthernetOutcomeReceiver().also {
+        runAsShell(MANAGE_TEST_NETWORKS) {
+            em.updateConfiguration(
+                iface.name,
+                EthernetNetworkUpdateRequest.Builder()
+                    .setIpConfiguration(ipConfig)
+                    .setNetworkCapabilities(capabilities).build(),
+                handler::post,
+                it)
+        }
+    }
+
+    // NetworkRequest.Builder does not create a copy of the passed NetworkRequest, so in order to
+    // keep ETH_REQUEST as it is, a defensive copy is created here.
     private fun NetworkRequest.createCopyWithEthernetSpecifier(ifaceName: String) =
         NetworkRequest.Builder(NetworkRequest(ETH_REQUEST))
             .setNetworkSpecifier(EthernetNetworkSpecifier(ifaceName)).build()
 
     // It can take multiple seconds for the network to become available.
     private fun TestableNetworkCallback.expectAvailable() =
-        expectCallback<Available>(anyNetwork(), 5000/*ms timeout*/).network
+        expectCallback<Available>(anyNetwork(), 5000 /* ms timeout */).network
 
     // b/233534110: eventuallyExpect<Lost>() does not advance ReadHead, use
     // eventuallyExpect(Lost::class) instead.
     private fun TestableNetworkCallback.eventuallyExpectLost(n: Network? = null) =
         eventuallyExpect(Lost::class, TIMEOUT_MS) { n?.equals(it.network) ?: true }
 
-    private fun TestableNetworkCallback.assertNotLost(n: Network? = null) =
+    private fun TestableNetworkCallback.assertNeverLost(n: Network? = null) =
         assertNoCallbackThat() { it is Lost && (n?.equals(it.network) ?: true) }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
+    private fun TestableNetworkCallback.assertNeverAvailable(n: Network? = null) =
+        assertNoCallbackThat() { it is Available && (n?.equals(it.network) ?: true) }
+
+    private fun TestableNetworkCallback.expectCapabilitiesWithInterfaceName(name: String) =
+        expectCapabilitiesThat(anyNetwork()) {
+            it.networkSpecifier == EthernetNetworkSpecifier(name)
+        }
+
     @Test
     fun testCallbacks() {
         // If an interface exists when the callback is registered, it is reported on registration.
@@ -358,32 +453,45 @@
         }
     }
 
-    // TODO: this function is now used in two places (EthernetManagerTest and
-    // EthernetTetheringTest), so it should be moved to testutils.
-    private fun isAdbOverNetwork(): Boolean {
-        // If adb TCP port opened, this test may running by adb over network.
-        return (SystemProperties.getInt("persist.adb.tcp.port", -1) > -1 ||
-                SystemProperties.getInt("service.adb.tcp.port", -1) > -1)
+    private fun assumeNoInterfaceForTetheringAvailable() {
+        // Interfaces that have configured NetworkCapabilities will never be used for tethering,
+        // see aosp/2123900.
+        try {
+            // assumeException does not exist.
+            requestTetheredInterface().expectOnAvailable()
+            // interface used for tethering is available, throw an assumption error.
+            assumeTrue(false)
+        } catch (e: TimeoutException) {
+            // do nothing -- the TimeoutException indicates that no interface is available for
+            // tethering.
+            releaseTetheredInterface()
+        }
     }
 
     @Test
     fun testCallbacks_forServerModeInterfaces() {
-        // do not run this test when adb might be connected over ethernet.
-        assumeFalse(isAdbOverNetwork())
+        // do not run this test if an interface that can be used for tethering already exists.
+        assumeNoInterfaceForTetheringAvailable()
+
+        val iface = createInterface()
+        requestTetheredInterface().expectOnAvailable()
 
         val listener = EthernetStateListener()
         addInterfaceStateListener(listener)
-
-        // it is possible that a physical interface is present, so it is not guaranteed that iface
-        // will be put into server mode. This should not matter for the test though. Calling
-        // createInterface() makes sure we have at least one interface available.
-        val iface = createInterface()
-        val cb = requestTetheredInterface()
-        val ifaceName = cb.expectOnAvailable()
-        listener.eventuallyExpect(ifaceName, STATE_LINK_UP, ROLE_SERVER)
+        // TODO(b/236895792): THIS IS A BUG! Existing server mode interfaces are not reported when
+        // an InterfaceStateListener is registered.
+        // Note: using eventuallyExpect as there may be other interfaces present.
+        // listener.eventuallyExpect(iface, STATE_LINK_UP, ROLE_SERVER)
 
         releaseTetheredInterface()
-        listener.eventuallyExpect(ifaceName, STATE_LINK_UP, ROLE_CLIENT)
+        listener.eventuallyExpect(iface, STATE_LINK_UP, ROLE_CLIENT)
+
+        requestTetheredInterface().expectOnAvailable()
+        // This should be changed to expectCallback, once b/236895792 is fixed.
+        listener.eventuallyExpect(iface, STATE_LINK_UP, ROLE_SERVER)
+
+        releaseTetheredInterface()
+        listener.expectCallback(iface, STATE_LINK_UP, ROLE_CLIENT)
     }
 
     /**
@@ -400,105 +508,85 @@
             assertTrue(polledIfaces.add(iface), "Duplicate interface $iface returned")
             assertTrue(ifaces.contains(iface), "Untracked interface $iface returned")
             // If the event's iface was created in the test, additional criteria can be validated.
-            createdIfaces.find { it.interfaceName.equals(iface) }?.let {
-                assertEquals(event,
-                    listener.createChangeEvent(it.interfaceName,
-                                                        STATE_LINK_UP,
-                                                        ROLE_CLIENT))
+            createdIfaces.find { it.name.equals(iface) }?.let {
+                assertEquals(event, listener.createChangeEvent(it.name, STATE_LINK_UP, ROLE_CLIENT))
             }
         }
         // Assert all callbacks are accounted for.
         listener.assertNoCallback()
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testGetInterfaceList() {
-        setIncludeTestInterfaces(true)
-
         // Create two test interfaces and check the return list contains the interface names.
         val iface1 = createInterface()
         val iface2 = createInterface()
         var ifaces = em.getInterfaceList()
         assertTrue(ifaces.size > 0)
-        assertTrue(ifaces.contains(iface1.interfaceName))
-        assertTrue(ifaces.contains(iface2.interfaceName))
+        assertTrue(ifaces.contains(iface1.name))
+        assertTrue(ifaces.contains(iface2.name))
 
         // Remove one existing test interface and check the return list doesn't contain the
         // removed interface name.
         removeInterface(iface1)
         ifaces = em.getInterfaceList()
-        assertFalse(ifaces.contains(iface1.interfaceName))
-        assertTrue(ifaces.contains(iface2.interfaceName))
+        assertFalse(ifaces.contains(iface1.name))
+        assertTrue(ifaces.contains(iface2.name))
 
         removeInterface(iface2)
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testNetworkRequest_withSingleExistingInterface() {
-        setIncludeTestInterfaces(true)
         createInterface()
 
         // install a listener which will later be used to verify the Lost callback
-        val listenerCb = TestableNetworkCallback()
-        cm.registerNetworkCallback(ETH_REQUEST, listenerCb)
-        networkRequests.add(listenerCb)
+        val listenerCb = registerNetworkListener(ETH_REQUEST)
 
         val cb = requestNetwork(ETH_REQUEST)
         val network = cb.expectAvailable()
 
-        cb.assertNotLost()
-        releaseNetwork(cb)
+        cb.assertNeverLost()
+        releaseRequest(cb)
         listenerCb.eventuallyExpectLost(network)
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testNetworkRequest_beforeSingleInterfaceIsUp() {
-        setIncludeTestInterfaces(true)
-
         val cb = requestNetwork(ETH_REQUEST)
 
-        // bring up interface after network has been requested
+        // bring up interface after network has been requested.
+        // Note: there is no guarantee that the NetworkRequest has been processed before the
+        // interface is actually created. That being said, it takes a few seconds between calling
+        // createInterface and the interface actually being properly registered with the ethernet
+        // module, so it is extremely unlikely that the CS handler thread has not run until then.
         val iface = createInterface()
         val network = cb.expectAvailable()
 
         // remove interface before network request has been removed
-        cb.assertNotLost()
+        cb.assertNeverLost()
         removeInterface(iface)
         cb.eventuallyExpectLost()
-
-        releaseNetwork(cb)
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testNetworkRequest_withMultipleInterfaces() {
-        setIncludeTestInterfaces(true)
-
         val iface1 = createInterface()
         val iface2 = createInterface()
 
-        val cb = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface2.interfaceName))
+        val cb = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface2.name))
 
         val network = cb.expectAvailable()
-        cb.expectCapabilitiesThat(network) {
-            it.networkSpecifier == EthernetNetworkSpecifier(iface2.interfaceName)
-        }
+        cb.expectCapabilitiesWithInterfaceName(iface2.name)
 
         removeInterface(iface1)
-        cb.assertNotLost()
+        cb.assertNeverLost()
         removeInterface(iface2)
         cb.eventuallyExpectLost()
-
-        releaseNetwork(cb)
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testNetworkRequest_withInterfaceBeingReplaced() {
-        setIncludeTestInterfaces(true)
         val iface1 = createInterface()
 
         val cb = requestNetwork(ETH_REQUEST)
@@ -506,37 +594,91 @@
 
         // create another network and verify the request sticks to the current network
         val iface2 = createInterface()
-        cb.assertNotLost()
+        cb.assertNeverLost()
 
         // remove iface1 and verify the request brings up iface2
         removeInterface(iface1)
         cb.eventuallyExpectLost(network)
         val network2 = cb.expectAvailable()
-
-        releaseNetwork(cb)
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     fun testNetworkRequest_withMultipleInterfacesAndRequests() {
-        setIncludeTestInterfaces(true)
         val iface1 = createInterface()
         val iface2 = createInterface()
 
-        val cb1 = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface1.interfaceName))
-        val cb2 = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface2.interfaceName))
+        val cb1 = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface1.name))
+        val cb2 = requestNetwork(ETH_REQUEST.createCopyWithEthernetSpecifier(iface2.name))
         val cb3 = requestNetwork(ETH_REQUEST)
 
         cb1.expectAvailable()
+        cb1.expectCapabilitiesWithInterfaceName(iface1.name)
         cb2.expectAvailable()
+        cb2.expectCapabilitiesWithInterfaceName(iface2.name)
+        // this request can be matched by either network.
         cb3.expectAvailable()
 
-        cb1.assertNotLost()
-        cb2.assertNotLost()
-        cb3.assertNotLost()
+        cb1.assertNeverLost()
+        cb2.assertNeverLost()
+        cb3.assertNeverLost()
+    }
 
-        releaseNetwork(cb1)
-        releaseNetwork(cb2)
-        releaseNetwork(cb3)
+    @Test
+    fun testNetworkRequest_ensureProperRefcounting() {
+        // create first request before interface is up / exists; create another request after it has
+        // been created; release one of them and check that the network stays up.
+        val listener = registerNetworkListener(ETH_REQUEST)
+        val cb1 = requestNetwork(ETH_REQUEST)
+
+        val iface = createInterface()
+        val network = cb1.expectAvailable()
+
+        val cb2 = requestNetwork(ETH_REQUEST)
+        cb2.expectAvailable()
+
+        // release the first request; this used to trigger b/197548738
+        releaseRequest(cb1)
+
+        cb2.assertNeverLost()
+        releaseRequest(cb2)
+        listener.eventuallyExpectLost(network)
+    }
+
+    @Test
+    fun testNetworkRequest_forInterfaceWhileTogglingCarrier() {
+        assumeChangingCarrierSupported()
+
+        val iface = createInterface(false /* hasCarrier */)
+
+        val cb = requestNetwork(ETH_REQUEST)
+        cb.assertNeverAvailable()
+
+        iface.setCarrierEnabled(true)
+        cb.expectAvailable()
+
+        iface.setCarrierEnabled(false)
+        cb.eventuallyExpectLost()
+    }
+
+    @Test
+    fun testRemoveInterface_whileInServerMode() {
+        assumeNoInterfaceForTetheringAvailable()
+
+        val listener = EthernetStateListener()
+        addInterfaceStateListener(listener)
+
+        val iface = createInterface()
+        val ifaceName = requestTetheredInterface().expectOnAvailable()
+
+        assertEquals(iface.name, ifaceName)
+        listener.eventuallyExpect(iface, STATE_LINK_UP, ROLE_SERVER)
+
+        removeInterface(iface)
+
+        // Note: removeInterface already verifies that a STATE_ABSENT, ROLE_NONE callback is
+        // received, but it can't hurt to explicitly check for it.
+        listener.expectCallback(iface, STATE_ABSENT, ROLE_NONE)
+        releaseTetheredInterface()
+        listener.assertNoCallback()
     }
 }
diff --git a/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java b/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java
index d618915..5ba6d69 100644
--- a/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java
@@ -56,6 +56,7 @@
 import android.net.NetworkStatsHistory;
 import android.net.TrafficStats;
 import android.net.netstats.NetworkStatsDataMigrationUtils;
+import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Process;
@@ -99,7 +100,7 @@
 @RunWith(AndroidJUnit4.class)
 public class NetworkStatsManagerTest {
     @Rule
-    public final DevSdkIgnoreRule ignoreRule = new DevSdkIgnoreRule(SC_V2 /* ignoreClassUpTo */);
+    public final DevSdkIgnoreRule ignoreRule = new DevSdkIgnoreRule(Build.VERSION_CODES.Q);
 
     private static final String LOG_TAG = "NetworkStatsManagerTest";
     private static final String APPOPS_SET_SHELL_COMMAND = "appops set {0} {1} {2}";
diff --git a/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt b/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
index 391d03a..462c8a3 100644
--- a/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
+++ b/tests/cts/net/src/android/net/cts/NetworkValidationTestUtil.kt
@@ -16,16 +16,11 @@
 
 package android.net.cts
 
-import android.Manifest
+import android.Manifest.permission.WRITE_DEVICE_CONFIG
 import android.net.util.NetworkStackUtils
 import android.provider.DeviceConfig
 import android.provider.DeviceConfig.NAMESPACE_CONNECTIVITY
-import android.util.Log
 import com.android.testutils.runAsShell
-import com.android.testutils.tryTest
-import java.util.concurrent.CompletableFuture
-import java.util.concurrent.Executor
-import java.util.concurrent.TimeUnit
 
 /**
  * Collection of utility methods for configuring network validation.
@@ -38,9 +33,14 @@
      * Clear the test network validation URLs.
      */
     @JvmStatic fun clearValidationTestUrlsDeviceConfig() {
-        setHttpsUrlDeviceConfig(null)
-        setHttpUrlDeviceConfig(null)
-        setUrlExpirationDeviceConfig(null)
+        runAsShell(WRITE_DEVICE_CONFIG) {
+            DeviceConfig.setProperty(NAMESPACE_CONNECTIVITY,
+                    NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTPS_URL, null, false)
+            DeviceConfig.setProperty(NAMESPACE_CONNECTIVITY,
+                    NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTP_URL, null, false)
+            DeviceConfig.setProperty(NAMESPACE_CONNECTIVITY,
+                    NetworkStackUtils.TEST_URL_EXPIRATION_TIME, null, false)
+        }
     }
 
     /**
@@ -48,71 +48,28 @@
      *
      * @see NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTPS_URL
      */
-    @JvmStatic fun setHttpsUrlDeviceConfig(url: String?) =
-            setConfig(NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTPS_URL, url)
+    @JvmStatic
+    fun setHttpsUrlDeviceConfig(rule: DeviceConfigRule, url: String?) =
+            rule.setConfig(NAMESPACE_CONNECTIVITY,
+                NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTPS_URL, url)
 
     /**
      * Set the test validation HTTP URL.
      *
      * @see NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTP_URL
      */
-    @JvmStatic fun setHttpUrlDeviceConfig(url: String?) =
-            setConfig(NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTP_URL, url)
+    @JvmStatic
+    fun setHttpUrlDeviceConfig(rule: DeviceConfigRule, url: String?) =
+            rule.setConfig(NAMESPACE_CONNECTIVITY,
+                NetworkStackUtils.TEST_CAPTIVE_PORTAL_HTTP_URL, url)
 
     /**
      * Set the test validation URL expiration.
      *
      * @see NetworkStackUtils.TEST_URL_EXPIRATION_TIME
      */
-    @JvmStatic fun setUrlExpirationDeviceConfig(timestamp: Long?) =
-            setConfig(NetworkStackUtils.TEST_URL_EXPIRATION_TIME, timestamp?.toString())
-
-    private fun setConfig(configKey: String, value: String?): String? {
-        Log.i(TAG, "Setting config \"$configKey\" to \"$value\"")
-        val readWritePermissions = arrayOf(
-                Manifest.permission.READ_DEVICE_CONFIG,
-                Manifest.permission.WRITE_DEVICE_CONFIG)
-
-        val existingValue = runAsShell(*readWritePermissions) {
-            DeviceConfig.getProperty(NAMESPACE_CONNECTIVITY, configKey)
-        }
-        if (existingValue == value) {
-            // Already the correct value. There may be a race if a change is already in flight,
-            // but if multiple threads update the config there is no way to fix that anyway.
-            Log.i(TAG, "\$configKey\" already had value \"$value\"")
-            return value
-        }
-
-        val future = CompletableFuture<String>()
-        val listener = DeviceConfig.OnPropertiesChangedListener {
-            // The listener receives updates for any change to any key, so don't react to
-            // changes that do not affect the relevant key
-            if (!it.keyset.contains(configKey)) return@OnPropertiesChangedListener
-            if (it.getString(configKey, null) == value) {
-                future.complete(value)
-            }
-        }
-
-        return tryTest {
-            runAsShell(*readWritePermissions) {
-                DeviceConfig.addOnPropertiesChangedListener(
-                        NAMESPACE_CONNECTIVITY,
-                        inlineExecutor,
-                        listener)
-                DeviceConfig.setProperty(
-                        NAMESPACE_CONNECTIVITY,
-                        configKey,
-                        value,
-                        false /* makeDefault */)
-                // Don't drop the permission until the config is applied, just in case
-                future.get(TIMEOUT_MS, TimeUnit.MILLISECONDS)
-            }.also {
-                Log.i(TAG, "Config \"$configKey\" successfully set to \"$value\"")
-            }
-        } cleanup {
-            DeviceConfig.removeOnPropertiesChangedListener(listener)
-        }
-    }
-
-    private val inlineExecutor get() = Executor { r -> r.run() }
+    @JvmStatic
+    fun setUrlExpirationDeviceConfig(rule: DeviceConfigRule, timestamp: Long?) =
+            rule.setConfig(NAMESPACE_CONNECTIVITY,
+                NetworkStackUtils.TEST_URL_EXPIRATION_TIME, timestamp?.toString())
 }
diff --git a/tests/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt b/tests/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
index 80338aa..efc24d3 100644
--- a/tests/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
+++ b/tests/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt
@@ -47,6 +47,7 @@
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry
 import com.android.connectivity.resources.R
+import com.android.server.BpfNetMaps
 import com.android.server.ConnectivityService
 import com.android.server.NetworkAgentWrapper
 import com.android.server.TestNetIdManager
@@ -208,6 +209,7 @@
         doReturn(mock(ProxyTracker::class.java)).`when`(deps).makeProxyTracker(any(), any())
         doReturn(mock(MockableSystemProperties::class.java)).`when`(deps).systemProperties
         doReturn(TestNetIdManager()).`when`(deps).makeNetIdManager()
+        doReturn(mock(BpfNetMaps::class.java)).`when`(deps).getBpfNetMaps(any())
         doAnswer { inv ->
             object : MultinetworkPolicyTracker(inv.getArgument(0), inv.getArgument(1),
                     inv.getArgument(2)) {
diff --git a/tests/integration/src/com/android/server/net/integrationtests/TestNetworkStackService.kt b/tests/integration/src/com/android/server/net/integrationtests/TestNetworkStackService.kt
index c7cf040..361c968 100644
--- a/tests/integration/src/com/android/server/net/integrationtests/TestNetworkStackService.kt
+++ b/tests/integration/src/com/android/server/net/integrationtests/TestNetworkStackService.kt
@@ -22,8 +22,8 @@
 import android.net.INetworkMonitorCallbacks
 import android.net.Network
 import android.net.metrics.IpConnectivityLog
-import android.net.util.SharedLog
 import android.os.IBinder
+import com.android.net.module.util.SharedLog
 import com.android.networkstack.netlink.TcpSocketTracker
 import com.android.server.NetworkStackService
 import com.android.server.NetworkStackService.NetworkMonitorConnector
diff --git a/tests/mts/bpf_existence_test.cpp b/tests/mts/bpf_existence_test.cpp
index db39e6f..2cd3310 100644
--- a/tests/mts/bpf_existence_test.cpp
+++ b/tests/mts/bpf_existence_test.cpp
@@ -124,6 +124,9 @@
 static const set<string> INTRODUCED_T_5_4 = {
     SHARED "prog_block_bind4_block_port",
     SHARED "prog_block_bind6_block_port",
+};
+
+static const set<string> INTRODUCED_T_5_15 = {
     SHARED "prog_dscp_policy_schedcls_set_dscp_ether",
     SHARED "prog_dscp_policy_schedcls_set_dscp_raw_ip",
 };
@@ -168,6 +171,7 @@
     if (IsAtLeastT()) {
         addAll(expected, INTRODUCED_T);
         if (android::bpf::isAtLeastKernelVersion(5, 4, 0)) addAll(expected, INTRODUCED_T_5_4);
+        if (android::bpf::isAtLeastKernelVersion(5, 15, 0)) addAll(expected, INTRODUCED_T_5_15);
         removeAll(expected, REMOVED_T);
 
         addAll(unexpected, REMOVED_T);
diff --git a/tests/native/Android.bp b/tests/native/Android.bp
index a8d908a..7d43aa8 100644
--- a/tests/native/Android.bp
+++ b/tests/native/Android.bp
@@ -31,3 +31,10 @@
     ],
     compile_multilib: "first",
 }
+
+filegroup {
+    name: "net_native_test_config_template",
+    srcs: [
+        "NetNativeTestConfigTemplate.xml",
+    ],
+}
diff --git a/tests/native/NetNativeTestConfigTemplate.xml b/tests/native/NetNativeTestConfigTemplate.xml
new file mode 100644
index 0000000..b71e9aa
--- /dev/null
+++ b/tests/native/NetNativeTestConfigTemplate.xml
@@ -0,0 +1,31 @@
+<!-- Copyright (C) 2022 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<configuration description="Configuration for {MODULE} tests">
+    <option name="test-suite-tag" value="mts" />
+    <option name="config-descriptor:metadata" key="mainline-param" value="CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex" />
+    <!-- Only run tests if the device under test is SDK version 33 (Android 13) or above. -->
+    <object type="module_controller" class="com.android.tradefed.testtype.suite.module.Sdk33ModuleController" />
+
+    <target_preparer class="com.android.tradefed.targetprep.RootTargetPreparer"/>
+    <target_preparer class="com.android.compatibility.common.tradefed.targetprep.FilePusher">
+        <option name="cleanup" value="true" />
+        <option name="push" value="{MODULE}->/data/local/tmp/{MODULE}" />
+        <option name="append-bitness" value="true" />
+    </target_preparer>
+    <test class="com.android.tradefed.testtype.GTest" >
+        <option name="native-test-device-path" value="/data/local/tmp" />
+        <option name="module-name" value="{MODULE}" />
+    </test>
+</configuration>
diff --git a/tests/unit/Android.bp b/tests/unit/Android.bp
index 18ace4e..590edf1 100644
--- a/tests/unit/Android.bp
+++ b/tests/unit/Android.bp
@@ -58,42 +58,23 @@
 filegroup {
     name: "non-connectivity-module-test",
     srcs: [
-        "java/android/app/usage/*.java",
-        "java/android/net/EthernetNetworkUpdateRequestTest.java",
         "java/android/net/Ikev2VpnProfileTest.java",
         "java/android/net/IpMemoryStoreTest.java",
-        "java/android/net/IpSecAlgorithmTest.java",
-        "java/android/net/IpSecConfigTest.java",
-        "java/android/net/IpSecManagerTest.java",
-        "java/android/net/IpSecTransformTest.java",
-        "java/android/net/KeepalivePacketDataUtilTest.java",
-        "java/android/net/NetworkIdentitySetTest.kt",
-        "java/android/net/NetworkIdentityTest.kt",
-        "java/android/net/NetworkStats*.java",
-        "java/android/net/NetworkTemplateTest.kt",
         "java/android/net/TelephonyNetworkSpecifierTest.java",
         "java/android/net/VpnManagerTest.java",
         "java/android/net/ipmemorystore/*.java",
         "java/android/net/netstats/NetworkStatsDataMigrationUtilsTest.kt",
-        "java/android/net/nsd/*.java",
         "java/com/android/internal/net/NetworkUtilsInternalTest.java",
         "java/com/android/internal/net/VpnProfileTest.java",
-        "java/com/android/server/IpSecServiceParameterizedTest.java",
-        "java/com/android/server/IpSecServiceRefcountedResourceTest.java",
-        "java/com/android/server/IpSecServiceTest.java",
         "java/com/android/server/NetworkManagementServiceTest.java",
-        "java/com/android/server/NsdServiceTest.java",
+        "java/com/android/server/VpnManagerServiceTest.java",
         "java/com/android/server/connectivity/IpConnectivityEventBuilderTest.java",
         "java/com/android/server/connectivity/IpConnectivityMetricsTest.java",
         "java/com/android/server/connectivity/MultipathPolicyTrackerTest.java",
         "java/com/android/server/connectivity/NetdEventListenerServiceTest.java",
         "java/com/android/server/connectivity/VpnTest.java",
-        "java/com/android/server/ethernet/*.java",
         "java/com/android/server/net/ipmemorystore/*.java",
-        "java/com/android/server/net/BpfInterfaceMapUpdaterTest.java",
-        "java/com/android/server/net/IpConfigStoreTest.java",
-        "java/com/android/server/net/NetworkStats*.java",
-        "java/com/android/server/net/TestableUsageCallback.kt",
+        "java/com/android/server/connectivity/mdns/**/*.java",
     ]
 }
 
@@ -168,6 +149,7 @@
     static_libs: [
         "services.core",
         "services.net",
+        "service-mdns",
     ],
     jni_libs: [
         "libandroid_net_connectivity_com_android_net_module_util_jni",
diff --git a/tests/unit/java/android/app/usage/NetworkStatsManagerTest.java b/tests/unit/java/android/app/usage/NetworkStatsManagerTest.java
index 561e621..b1b76ec 100644
--- a/tests/unit/java/android/app/usage/NetworkStatsManagerTest.java
+++ b/tests/unit/java/android/app/usage/NetworkStatsManagerTest.java
@@ -54,7 +54,7 @@
 
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NetworkStatsManagerTest {
     private static final String TEST_SUBSCRIBER_ID = "subid";
 
diff --git a/tests/unit/java/android/net/ConnectivityManagerTest.java b/tests/unit/java/android/net/ConnectivityManagerTest.java
index f324630..c327868 100644
--- a/tests/unit/java/android/net/ConnectivityManagerTest.java
+++ b/tests/unit/java/android/net/ConnectivityManagerTest.java
@@ -41,6 +41,7 @@
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyBoolean;
@@ -72,6 +73,7 @@
 
 import androidx.test.filters.SmallTest;
 
+import com.android.internal.util.test.BroadcastInterceptingContext;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
 
@@ -82,6 +84,8 @@
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import java.lang.ref.WeakReference;
+
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
 @DevSdkIgnoreRule.IgnoreUpTo(VERSION_CODES.R)
@@ -461,4 +465,49 @@
         }
         fail("expected exception of type " + throwableType);
     }
+
+    private static class MockContext extends BroadcastInterceptingContext {
+        MockContext(Context base) {
+            super(base);
+        }
+
+        @Override
+        public Context getApplicationContext() {
+            return mock(Context.class);
+        }
+    }
+
+    private WeakReference<Context> makeConnectivityManagerAndReturnContext() {
+        // Mockito may have an internal reference to the mock, creating MockContext for testing.
+        final Context c = new MockContext(mock(Context.class));
+
+        new ConnectivityManager(c, mService);
+
+        return new WeakReference<>(c);
+    }
+
+    private void forceGC() {
+        // First GC ensures that objects are collected for finalization, then second GC ensures
+        // they're garbage-collected after being finalized.
+        System.gc();
+        System.runFinalization();
+        System.gc();
+    }
+
+    @Test
+    public void testConnectivityManagerDoesNotLeakContext() throws Exception {
+        final WeakReference<Context> ref = makeConnectivityManagerAndReturnContext();
+
+        final int attempts = 100;
+        final long waitIntervalMs = 50;
+        for (int i = 0; i < attempts; i++) {
+            forceGC();
+            if (ref.get() == null) break;
+
+            Thread.sleep(waitIntervalMs);
+        }
+
+        assertNull("ConnectivityManager weak reference still not null after " + attempts
+                    + " attempts", ref.get());
+    }
 }
diff --git a/tests/unit/java/android/net/IpSecAlgorithmTest.java b/tests/unit/java/android/net/IpSecAlgorithmTest.java
index c473e82..1482055 100644
--- a/tests/unit/java/android/net/IpSecAlgorithmTest.java
+++ b/tests/unit/java/android/net/IpSecAlgorithmTest.java
@@ -47,7 +47,7 @@
 /** Unit tests for {@link IpSecAlgorithm}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecAlgorithmTest {
     private static final byte[] KEY_MATERIAL;
 
diff --git a/tests/unit/java/android/net/IpSecConfigTest.java b/tests/unit/java/android/net/IpSecConfigTest.java
index b87cb48..9f83036 100644
--- a/tests/unit/java/android/net/IpSecConfigTest.java
+++ b/tests/unit/java/android/net/IpSecConfigTest.java
@@ -36,7 +36,7 @@
 /** Unit tests for {@link IpSecConfig}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecConfigTest {
 
     @Test
diff --git a/tests/unit/java/android/net/IpSecManagerTest.java b/tests/unit/java/android/net/IpSecManagerTest.java
index cda8eb7..335f539 100644
--- a/tests/unit/java/android/net/IpSecManagerTest.java
+++ b/tests/unit/java/android/net/IpSecManagerTest.java
@@ -52,7 +52,7 @@
 /** Unit tests for {@link IpSecManager}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecManagerTest {
 
     private static final int TEST_UDP_ENCAP_PORT = 34567;
diff --git a/tests/unit/java/android/net/IpSecTransformTest.java b/tests/unit/java/android/net/IpSecTransformTest.java
index 81375f1..c1bd719 100644
--- a/tests/unit/java/android/net/IpSecTransformTest.java
+++ b/tests/unit/java/android/net/IpSecTransformTest.java
@@ -32,7 +32,7 @@
 /** Unit tests for {@link IpSecTransform}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecTransformTest {
 
     @Test
diff --git a/tests/unit/java/android/net/NetworkIdentityTest.kt b/tests/unit/java/android/net/NetworkIdentityTest.kt
index bf5568d..d84328c 100644
--- a/tests/unit/java/android/net/NetworkIdentityTest.kt
+++ b/tests/unit/java/android/net/NetworkIdentityTest.kt
@@ -47,7 +47,7 @@
 private const val TEST_SUBID2 = 2
 
 @RunWith(DevSdkIgnoreRunner::class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 class NetworkIdentityTest {
     private val mockContext = mock(Context::class.java)
 
diff --git a/tests/unit/java/android/net/NetworkStatsAccessTest.java b/tests/unit/java/android/net/NetworkStatsAccessTest.java
index 97a93ca..a74056b 100644
--- a/tests/unit/java/android/net/NetworkStatsAccessTest.java
+++ b/tests/unit/java/android/net/NetworkStatsAccessTest.java
@@ -19,6 +19,7 @@
 import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 
 import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.when;
 
 import android.Manifest;
@@ -66,6 +67,10 @@
         when(mContext.getSystemServiceName(DevicePolicyManager.class))
                 .thenReturn(Context.DEVICE_POLICY_SERVICE);
         when(mContext.getSystemService(Context.DEVICE_POLICY_SERVICE)).thenReturn(mDpm);
+        if (mContext.getSystemService(DevicePolicyManager.class) == null) {
+            // Test is using mockito-extended
+            doCallRealMethod().when(mContext).getSystemService(DevicePolicyManager.class);
+        }
 
         setHasCarrierPrivileges(false);
         setIsDeviceOwner(false);
diff --git a/tests/unit/java/android/net/NetworkStatsHistoryTest.java b/tests/unit/java/android/net/NetworkStatsHistoryTest.java
index 26079a2..43e331b 100644
--- a/tests/unit/java/android/net/NetworkStatsHistoryTest.java
+++ b/tests/unit/java/android/net/NetworkStatsHistoryTest.java
@@ -60,7 +60,7 @@
 
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NetworkStatsHistoryTest {
     private static final String TAG = "NetworkStatsHistoryTest";
 
diff --git a/tests/unit/java/android/net/NetworkStatsTest.java b/tests/unit/java/android/net/NetworkStatsTest.java
index b0cc16c..6d79869 100644
--- a/tests/unit/java/android/net/NetworkStatsTest.java
+++ b/tests/unit/java/android/net/NetworkStatsTest.java
@@ -61,7 +61,7 @@
 
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NetworkStatsTest {
 
     private static final String TEST_IFACE = "test0";
diff --git a/tests/unit/java/android/net/NetworkTemplateTest.kt b/tests/unit/java/android/net/NetworkTemplateTest.kt
index abd1825..3e9662d 100644
--- a/tests/unit/java/android/net/NetworkTemplateTest.kt
+++ b/tests/unit/java/android/net/NetworkTemplateTest.kt
@@ -70,7 +70,7 @@
 private const val TEST_WIFI_KEY2 = "wifiKey2"
 
 @RunWith(DevSdkIgnoreRunner::class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 class NetworkTemplateTest {
     private val mockContext = mock(Context::class.java)
     private val mockWifiInfo = mock(WifiInfo::class.java)
diff --git a/tests/unit/java/android/net/QosSocketFilterTest.java b/tests/unit/java/android/net/QosSocketFilterTest.java
index 91f2cdd..6820b40 100644
--- a/tests/unit/java/android/net/QosSocketFilterTest.java
+++ b/tests/unit/java/android/net/QosSocketFilterTest.java
@@ -16,8 +16,17 @@
 
 package android.net;
 
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_NONE;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_BOUND;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_NOT_CONNECTED;
+import static android.net.QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED;
+import static android.system.OsConstants.IPPROTO_TCP;
+import static android.system.OsConstants.IPPROTO_UDP;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import android.os.Build;
 
@@ -29,6 +38,7 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.net.DatagramSocket;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 
@@ -36,14 +46,14 @@
 @SmallTest
 @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
 public class QosSocketFilterTest {
-
+    private static final int TEST_NET_ID = 1777;
+    private final Network mNetwork = new Network(TEST_NET_ID);
     @Test
     public void testPortExactMatch() {
         final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
         final InetAddress addressB = InetAddresses.parseNumericAddress("1.2.3.4");
         assertTrue(QosSocketFilter.matchesAddress(
                 new InetSocketAddress(addressA, 10), addressB, 10, 10));
-
     }
 
     @Test
@@ -77,5 +87,90 @@
         assertFalse(QosSocketFilter.matchesAddress(
                 new InetSocketAddress(addressA, 10), addressB, 10, 10));
     }
+
+    @Test
+    public void testAddressMatchWithAnyLocalAddresses() {
+        final InetAddress addressA = InetAddresses.parseNumericAddress("1.2.3.4");
+        final InetAddress addressB = InetAddresses.parseNumericAddress("0.0.0.0");
+        assertTrue(QosSocketFilter.matchesAddress(
+                new InetSocketAddress(addressA, 10), addressB, 10, 10));
+        assertFalse(QosSocketFilter.matchesAddress(
+                new InetSocketAddress(addressB, 10), addressA, 10, 10));
+    }
+
+    @Test
+    public void testProtocolMatch() throws Exception {
+        DatagramSocket socket = new DatagramSocket(new InetSocketAddress("127.0.0.1", 0));
+        socket.connect(new InetSocketAddress("127.0.0.1", socket.getLocalPort() + 10));
+        DatagramSocket socketV6 = new DatagramSocket(new InetSocketAddress("::1", 0));
+        socketV6.connect(new InetSocketAddress("::1", socketV6.getLocalPort() + 10));
+        QosSocketInfo socketInfo = new QosSocketInfo(mNetwork, socket);
+        QosSocketFilter socketFilter = new QosSocketFilter(socketInfo);
+        QosSocketInfo socketInfo6 = new QosSocketInfo(mNetwork, socketV6);
+        QosSocketFilter socketFilter6 = new QosSocketFilter(socketInfo6);
+        assertTrue(socketFilter.matchesProtocol(IPPROTO_UDP));
+        assertTrue(socketFilter6.matchesProtocol(IPPROTO_UDP));
+        assertFalse(socketFilter.matchesProtocol(IPPROTO_TCP));
+        assertFalse(socketFilter6.matchesProtocol(IPPROTO_TCP));
+        socket.close();
+        socketV6.close();
+    }
+
+    @Test
+    public void testValidate() throws Exception {
+        DatagramSocket socket = new DatagramSocket(new InetSocketAddress("127.0.0.1", 0));
+        socket.connect(new InetSocketAddress("127.0.0.1", socket.getLocalPort() + 7));
+        DatagramSocket socketV6 = new DatagramSocket(new InetSocketAddress("::1", 0));
+
+        QosSocketInfo socketInfo = new QosSocketInfo(mNetwork, socket);
+        QosSocketFilter socketFilter = new QosSocketFilter(socketInfo);
+        QosSocketInfo socketInfo6 = new QosSocketInfo(mNetwork, socketV6);
+        QosSocketFilter socketFilter6 = new QosSocketFilter(socketInfo6);
+        assertEquals(EX_TYPE_FILTER_NONE, socketFilter.validate());
+        assertEquals(EX_TYPE_FILTER_NONE, socketFilter6.validate());
+        socket.close();
+        socketV6.close();
+    }
+
+    @Test
+    public void testValidateUnbind() throws Exception {
+        DatagramSocket socket;
+        socket = new DatagramSocket(null);
+        QosSocketInfo socketInfo = new QosSocketInfo(mNetwork, socket);
+        QosSocketFilter socketFilter = new QosSocketFilter(socketInfo);
+        assertEquals(EX_TYPE_FILTER_SOCKET_NOT_BOUND, socketFilter.validate());
+        socket.close();
+    }
+
+    @Test
+    public void testValidateLocalAddressChanged() throws Exception {
+        DatagramSocket socket = new DatagramSocket(null);
+        DatagramSocket socket6 = new DatagramSocket(null);
+        QosSocketInfo socketInfo = new QosSocketInfo(mNetwork, socket);
+        QosSocketFilter socketFilter = new QosSocketFilter(socketInfo);
+        QosSocketInfo socketInfo6 = new QosSocketInfo(mNetwork, socket6);
+        QosSocketFilter socketFilter6 = new QosSocketFilter(socketInfo6);
+        socket.bind(new InetSocketAddress("127.0.0.1", 0));
+        socket6.bind(new InetSocketAddress("::1", 0));
+        assertEquals(EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED, socketFilter.validate());
+        assertEquals(EX_TYPE_FILTER_SOCKET_LOCAL_ADDRESS_CHANGED, socketFilter6.validate());
+        socket.close();
+        socket6.close();
+    }
+
+    @Test
+    public void testValidateRemoteAddressChanged() throws Exception {
+        DatagramSocket socket;
+        socket = new DatagramSocket(new InetSocketAddress("127.0.0.1", 53137));
+        socket.connect(new InetSocketAddress("127.0.0.1", socket.getLocalPort() + 11));
+        QosSocketInfo socketInfo = new QosSocketInfo(mNetwork, socket);
+        QosSocketFilter socketFilter = new QosSocketFilter(socketInfo);
+        assertEquals(EX_TYPE_FILTER_NONE, socketFilter.validate());
+        socket.disconnect();
+        assertEquals(EX_TYPE_FILTER_SOCKET_NOT_CONNECTED, socketFilter.validate());
+        socket.connect(new InetSocketAddress("127.0.0.1", socket.getLocalPort() + 13));
+        assertEquals(EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED, socketFilter.validate());
+        socket.close();
+    }
 }
 
diff --git a/tests/unit/java/android/net/QosSocketInfoTest.java b/tests/unit/java/android/net/QosSocketInfoTest.java
new file mode 100644
index 0000000..749c182
--- /dev/null
+++ b/tests/unit/java/android/net/QosSocketInfoTest.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import static android.system.OsConstants.SOCK_DGRAM;
+import static android.system.OsConstants.SOCK_STREAM;
+
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+
+import android.os.Build;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+@RunWith(DevSdkIgnoreRunner.class)
+@SmallTest
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+public class QosSocketInfoTest {
+    @Mock
+    private Network mMockNetwork = mock(Network.class);
+
+    @Test
+    public void testConstructWithSock() throws Exception {
+        ServerSocket server = new ServerSocket();
+        ServerSocket server6 = new ServerSocket();
+
+        InetSocketAddress clientAddr = new InetSocketAddress("127.0.0.1", 0);
+        InetSocketAddress serverAddr = new InetSocketAddress("127.0.0.1", 0);
+        InetSocketAddress clientAddr6 = new InetSocketAddress("::1", 0);
+        InetSocketAddress serverAddr6 = new InetSocketAddress("::1", 0);
+        server.bind(serverAddr);
+        server6.bind(serverAddr6);
+        Socket socket = new Socket(serverAddr.getAddress(), server.getLocalPort(),
+                clientAddr.getAddress(), clientAddr.getPort());
+        Socket socket6 = new Socket(serverAddr6.getAddress(), server6.getLocalPort(),
+                clientAddr6.getAddress(), clientAddr6.getPort());
+        QosSocketInfo sockInfo = new QosSocketInfo(mMockNetwork, socket);
+        QosSocketInfo sockInfo6 = new QosSocketInfo(mMockNetwork, socket6);
+        assertTrue(sockInfo.getLocalSocketAddress()
+                .equals(new InetSocketAddress(socket.getLocalAddress(), socket.getLocalPort())));
+        assertTrue(sockInfo.getRemoteSocketAddress()
+                .equals((InetSocketAddress) socket.getRemoteSocketAddress()));
+        assertEquals(SOCK_STREAM, sockInfo.getSocketType());
+        assertTrue(sockInfo6.getLocalSocketAddress()
+                .equals(new InetSocketAddress(socket6.getLocalAddress(), socket6.getLocalPort())));
+        assertTrue(sockInfo6.getRemoteSocketAddress()
+                .equals((InetSocketAddress) socket6.getRemoteSocketAddress()));
+        assertEquals(SOCK_STREAM, sockInfo6.getSocketType());
+        socket.close();
+        socket6.close();
+        server.close();
+        server6.close();
+    }
+
+    @Test
+    public void testConstructWithDatagramSock() throws Exception {
+        InetSocketAddress clientAddr = new InetSocketAddress("127.0.0.1", 0);
+        InetSocketAddress serverAddr = new InetSocketAddress("127.0.0.1", 0);
+        InetSocketAddress clientAddr6 = new InetSocketAddress("::1", 0);
+        InetSocketAddress serverAddr6 = new InetSocketAddress("::1", 0);
+        DatagramSocket socket = new DatagramSocket(null);
+        socket.setReuseAddress(true);
+        socket.bind(clientAddr);
+        socket.connect(serverAddr);
+        DatagramSocket socket6 = new DatagramSocket(null);
+        socket6.setReuseAddress(true);
+        socket6.bind(clientAddr);
+        socket6.connect(serverAddr);
+        QosSocketInfo sockInfo = new QosSocketInfo(mMockNetwork, socket);
+        QosSocketInfo sockInfo6 = new QosSocketInfo(mMockNetwork, socket6);
+        assertTrue(sockInfo.getLocalSocketAddress()
+                .equals((InetSocketAddress) socket.getLocalSocketAddress()));
+        assertTrue(sockInfo.getRemoteSocketAddress()
+                .equals((InetSocketAddress) socket.getRemoteSocketAddress()));
+        assertEquals(SOCK_DGRAM, sockInfo.getSocketType());
+        assertTrue(sockInfo6.getLocalSocketAddress()
+                .equals((InetSocketAddress) socket6.getLocalSocketAddress()));
+        assertTrue(sockInfo6.getRemoteSocketAddress()
+                .equals((InetSocketAddress) socket6.getRemoteSocketAddress()));
+        assertEquals(SOCK_DGRAM, sockInfo6.getSocketType());
+        socket.close();
+    }
+}
diff --git a/tests/unit/java/android/net/nsd/NsdManagerTest.java b/tests/unit/java/android/net/nsd/NsdManagerTest.java
index 30b8fcd..32274bc 100644
--- a/tests/unit/java/android/net/nsd/NsdManagerTest.java
+++ b/tests/unit/java/android/net/nsd/NsdManagerTest.java
@@ -51,7 +51,7 @@
 
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NsdManagerTest {
 
     static final int PROTOCOL = NsdManager.PROTOCOL_DNS_SD;
diff --git a/tests/unit/java/android/net/nsd/NsdServiceInfoTest.java b/tests/unit/java/android/net/nsd/NsdServiceInfoTest.java
index 892e140..64355ed 100644
--- a/tests/unit/java/android/net/nsd/NsdServiceInfoTest.java
+++ b/tests/unit/java/android/net/nsd/NsdServiceInfoTest.java
@@ -42,7 +42,7 @@
 
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NsdServiceInfoTest {
 
     public final static InetAddress LOCALHOST;
diff --git a/tests/unit/java/com/android/server/BpfNetMapsTest.java b/tests/unit/java/com/android/server/BpfNetMapsTest.java
index f07a10d..98d0905 100644
--- a/tests/unit/java/com/android/server/BpfNetMapsTest.java
+++ b/tests/unit/java/com/android/server/BpfNetMapsTest.java
@@ -16,53 +16,545 @@
 
 package com.android.server;
 
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_DOZABLE;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOW_POWER_STANDBY;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_1;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_2;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_3;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_POWERSAVE;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_RESTRICTED;
+import static android.net.ConnectivityManager.FIREWALL_CHAIN_STANDBY;
 import static android.net.INetd.PERMISSION_INTERNET;
 
+import static com.android.server.BpfNetMaps.DOZABLE_MATCH;
+import static com.android.server.BpfNetMaps.HAPPY_BOX_MATCH;
+import static com.android.server.BpfNetMaps.IIF_MATCH;
+import static com.android.server.BpfNetMaps.LOCKDOWN_VPN_MATCH;
+import static com.android.server.BpfNetMaps.NO_MATCH;
+import static com.android.server.BpfNetMaps.PENALTY_BOX_MATCH;
+import static com.android.server.BpfNetMaps.POWERSAVE_MATCH;
+import static com.android.server.BpfNetMaps.RESTRICTED_MATCH;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeFalse;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.verify;
 
 import android.net.INetd;
 import android.os.Build;
+import android.os.ServiceSpecificException;
 
 import androidx.test.filters.SmallTest;
 
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.BpfMap;
+import com.android.net.module.util.Struct.U32;
 import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
+import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.DevSdkIgnoreRunner;
+import com.android.testutils.TestBpfMap;
 
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+import java.util.List;
+
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
 @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
 public final class BpfNetMapsTest {
     private static final String TAG = "BpfNetMapsTest";
+
+    @Rule
+    public final DevSdkIgnoreRule ignoreRule = new DevSdkIgnoreRule();
+
     private static final int TEST_UID = 10086;
     private static final int[] TEST_UIDS = {10002, 10003};
-    private static final String IFNAME = "wlan0";
+    private static final String TEST_IF_NAME = "wlan0";
+    private static final int TEST_IF_INDEX = 7;
+    private static final int NO_IIF = 0;
+    private static final int NULL_IIF = 0;
     private static final String CHAINNAME = "fw_dozable";
+    private static final U32 UID_RULES_CONFIGURATION_KEY = new U32(0);
+    private static final List<Integer> FIREWALL_CHAINS = List.of(
+            FIREWALL_CHAIN_DOZABLE,
+            FIREWALL_CHAIN_STANDBY,
+            FIREWALL_CHAIN_POWERSAVE,
+            FIREWALL_CHAIN_RESTRICTED,
+            FIREWALL_CHAIN_LOW_POWER_STANDBY,
+            FIREWALL_CHAIN_OEM_DENY_1,
+            FIREWALL_CHAIN_OEM_DENY_2,
+            FIREWALL_CHAIN_OEM_DENY_3
+    );
+
     private BpfNetMaps mBpfNetMaps;
 
     @Mock INetd mNetd;
+    @Mock BpfNetMaps.Dependencies mDeps;
+    private final BpfMap<U32, U32> mConfigurationMap = new TestBpfMap<>(U32.class, U32.class);
+    private final BpfMap<U32, UidOwnerValue> mUidOwnerMap =
+            new TestBpfMap<>(U32.class, UidOwnerValue.class);
 
     @Before
-    public void setUp() {
+    public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
-        mBpfNetMaps = new BpfNetMaps(mNetd);
+        doReturn(TEST_IF_INDEX).when(mDeps).getIfIndex(TEST_IF_NAME);
+        BpfNetMaps.setConfigurationMapForTest(mConfigurationMap);
+        BpfNetMaps.setUidOwnerMapForTest(mUidOwnerMap);
+        mBpfNetMaps = new BpfNetMaps(mNetd, mDeps);
     }
 
     @Test
     public void testBpfNetMapsBeforeT() throws Exception {
         assumeFalse(SdkLevel.isAtLeastT());
-        mBpfNetMaps.addUidInterfaceRules(IFNAME, TEST_UIDS);
-        verify(mNetd).firewallAddUidInterfaceRules(IFNAME, TEST_UIDS);
+        mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
+        verify(mNetd).firewallAddUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
         mBpfNetMaps.removeUidInterfaceRules(TEST_UIDS);
         verify(mNetd).firewallRemoveUidInterfaceRules(TEST_UIDS);
         mBpfNetMaps.setNetPermForUids(PERMISSION_INTERNET, TEST_UIDS);
         verify(mNetd).trafficSetNetPermForUids(PERMISSION_INTERNET, TEST_UIDS);
     }
+
+    private void doTestIsChainEnabled(final List<Integer> enableChains) throws Exception {
+        long match = 0;
+        for (final int chain: enableChains) {
+            match |= mBpfNetMaps.getMatchByFirewallChain(chain);
+        }
+        mConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY, new U32(match));
+
+        for (final int chain: FIREWALL_CHAINS) {
+            final String testCase = "EnabledChains: " + enableChains + " CheckedChain: " + chain;
+            if (enableChains.contains(chain)) {
+                assertTrue("Expected isChainEnabled returns True, " + testCase,
+                        mBpfNetMaps.isChainEnabled(chain));
+            } else {
+                assertFalse("Expected isChainEnabled returns False, " + testCase,
+                        mBpfNetMaps.isChainEnabled(chain));
+            }
+        }
+    }
+
+    private void doTestIsChainEnabled(final int enableChain) throws Exception {
+        doTestIsChainEnabled(List.of(enableChain));
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testIsChainEnabled() throws Exception {
+        doTestIsChainEnabled(FIREWALL_CHAIN_DOZABLE);
+        doTestIsChainEnabled(FIREWALL_CHAIN_STANDBY);
+        doTestIsChainEnabled(FIREWALL_CHAIN_POWERSAVE);
+        doTestIsChainEnabled(FIREWALL_CHAIN_RESTRICTED);
+        doTestIsChainEnabled(FIREWALL_CHAIN_LOW_POWER_STANDBY);
+        doTestIsChainEnabled(FIREWALL_CHAIN_OEM_DENY_1);
+        doTestIsChainEnabled(FIREWALL_CHAIN_OEM_DENY_2);
+        doTestIsChainEnabled(FIREWALL_CHAIN_OEM_DENY_3);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testIsChainEnabledMultipleChainEnabled() throws Exception {
+        doTestIsChainEnabled(List.of(
+                FIREWALL_CHAIN_DOZABLE,
+                FIREWALL_CHAIN_STANDBY));
+        doTestIsChainEnabled(List.of(
+                FIREWALL_CHAIN_DOZABLE,
+                FIREWALL_CHAIN_STANDBY,
+                FIREWALL_CHAIN_POWERSAVE,
+                FIREWALL_CHAIN_RESTRICTED));
+        doTestIsChainEnabled(FIREWALL_CHAINS);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testIsChainEnabledInvalidChain() {
+        final Class<ServiceSpecificException> expected = ServiceSpecificException.class;
+        assertThrows(expected, () -> mBpfNetMaps.isChainEnabled(-1 /* childChain */));
+        assertThrows(expected, () -> mBpfNetMaps.isChainEnabled(1000 /* childChain */));
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testIsChainEnabledBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.isChainEnabled(FIREWALL_CHAIN_DOZABLE));
+    }
+
+    private void doTestSetChildChain(final List<Integer> testChains) throws Exception {
+        long expectedMatch = 0;
+        for (final int chain: testChains) {
+            expectedMatch |= mBpfNetMaps.getMatchByFirewallChain(chain);
+        }
+
+        assertEquals(0, mConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY).val);
+
+        for (final int chain: testChains) {
+            mBpfNetMaps.setChildChain(chain, true /* enable */);
+        }
+        assertEquals(expectedMatch, mConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY).val);
+
+        for (final int chain: testChains) {
+            mBpfNetMaps.setChildChain(chain, false /* enable */);
+        }
+        assertEquals(0, mConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY).val);
+    }
+
+    private void doTestSetChildChain(final int testChain) throws Exception {
+        doTestSetChildChain(List.of(testChain));
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testSetChildChain() throws Exception {
+        mConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY, new U32(0));
+        doTestSetChildChain(FIREWALL_CHAIN_DOZABLE);
+        doTestSetChildChain(FIREWALL_CHAIN_STANDBY);
+        doTestSetChildChain(FIREWALL_CHAIN_POWERSAVE);
+        doTestSetChildChain(FIREWALL_CHAIN_RESTRICTED);
+        doTestSetChildChain(FIREWALL_CHAIN_LOW_POWER_STANDBY);
+        doTestSetChildChain(FIREWALL_CHAIN_OEM_DENY_1);
+        doTestSetChildChain(FIREWALL_CHAIN_OEM_DENY_2);
+        doTestSetChildChain(FIREWALL_CHAIN_OEM_DENY_3);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testSetChildChainMultipleChain() throws Exception {
+        mConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY, new U32(0));
+        doTestSetChildChain(List.of(
+                FIREWALL_CHAIN_DOZABLE,
+                FIREWALL_CHAIN_STANDBY));
+        doTestSetChildChain(List.of(
+                FIREWALL_CHAIN_DOZABLE,
+                FIREWALL_CHAIN_STANDBY,
+                FIREWALL_CHAIN_POWERSAVE,
+                FIREWALL_CHAIN_RESTRICTED));
+        doTestSetChildChain(FIREWALL_CHAINS);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testSetChildChainInvalidChain() {
+        final Class<ServiceSpecificException> expected = ServiceSpecificException.class;
+        assertThrows(expected,
+                () -> mBpfNetMaps.setChildChain(-1 /* childChain */, true /* enable */));
+        assertThrows(expected,
+                () -> mBpfNetMaps.setChildChain(1000 /* childChain */, true /* enable */));
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testSetChildChainBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.setChildChain(FIREWALL_CHAIN_DOZABLE, true /* enable */));
+    }
+
+    private void checkUidOwnerValue(final long uid, final long expectedIif,
+            final long expectedMatch) throws Exception {
+        final UidOwnerValue config = mUidOwnerMap.getValue(new U32(uid));
+        if (expectedMatch == 0) {
+            assertNull(config);
+        } else {
+            assertEquals(expectedIif, config.iif);
+            assertEquals(expectedMatch, config.rule);
+        }
+    }
+
+    private void doTestRemoveNaughtyApp(final long iif, final long match) throws Exception {
+        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+
+        mBpfNetMaps.removeNaughtyApp(TEST_UID);
+
+        checkUidOwnerValue(TEST_UID, iif, match & ~PENALTY_BOX_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyApp() throws Exception {
+        doTestRemoveNaughtyApp(NO_IIF, PENALTY_BOX_MATCH);
+
+        // PENALTY_BOX_MATCH with other matches
+        doTestRemoveNaughtyApp(NO_IIF, PENALTY_BOX_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH);
+
+        // PENALTY_BOX_MATCH with IIF_MATCH
+        doTestRemoveNaughtyApp(TEST_IF_INDEX, PENALTY_BOX_MATCH | IIF_MATCH);
+
+        // PENALTY_BOX_MATCH is not enabled
+        doTestRemoveNaughtyApp(NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyAppMissingUid() {
+        // UidOwnerMap does not have entry for TEST_UID
+        assertThrows(ServiceSpecificException.class,
+                () -> mBpfNetMaps.removeNaughtyApp(TEST_UID));
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testRemoveNaughtyAppBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.removeNaughtyApp(TEST_UID));
+    }
+
+    private void doTestAddNaughtyApp(final long iif, final long match) throws Exception {
+        if (match != NO_MATCH) {
+            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+        }
+
+        mBpfNetMaps.addNaughtyApp(TEST_UID);
+
+        checkUidOwnerValue(TEST_UID, iif, match | PENALTY_BOX_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddNaughtyApp() throws Exception {
+        doTestAddNaughtyApp(NO_IIF, NO_MATCH);
+
+        // Other matches are enabled
+        doTestAddNaughtyApp(NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+
+        // IIF_MATCH is enabled
+        doTestAddNaughtyApp(TEST_IF_INDEX, IIF_MATCH);
+
+        // PENALTY_BOX_MATCH is already enabled
+        doTestAddNaughtyApp(NO_IIF, PENALTY_BOX_MATCH | DOZABLE_MATCH);
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testAddNaughtyAppBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.addNaughtyApp(TEST_UID));
+    }
+
+    private void doTestRemoveNiceApp(final long iif, final long match) throws Exception {
+        mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+
+        mBpfNetMaps.removeNiceApp(TEST_UID);
+
+        checkUidOwnerValue(TEST_UID, iif, match & ~HAPPY_BOX_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNiceApp() throws Exception {
+        doTestRemoveNiceApp(NO_IIF, HAPPY_BOX_MATCH);
+
+        // HAPPY_BOX_MATCH with other matches
+        doTestRemoveNiceApp(NO_IIF, HAPPY_BOX_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH);
+
+        // HAPPY_BOX_MATCH with IIF_MATCH
+        doTestRemoveNiceApp(TEST_IF_INDEX, HAPPY_BOX_MATCH | IIF_MATCH);
+
+        // HAPPY_BOX_MATCH is not enabled
+        doTestRemoveNiceApp(NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveNiceAppMissingUid() {
+        // UidOwnerMap does not have entry for TEST_UID
+        assertThrows(ServiceSpecificException.class,
+                () -> mBpfNetMaps.removeNiceApp(TEST_UID));
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testRemoveNiceAppBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.removeNiceApp(TEST_UID));
+    }
+
+    private void doTestAddNiceApp(final long iif, final long match) throws Exception {
+        if (match != NO_MATCH) {
+            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+        }
+
+        mBpfNetMaps.addNiceApp(TEST_UID);
+
+        checkUidOwnerValue(TEST_UID, iif, match | HAPPY_BOX_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddNiceApp() throws Exception {
+        doTestAddNiceApp(NO_IIF, NO_MATCH);
+
+        // Other matches are enabled
+        doTestAddNiceApp(NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+
+        // IIF_MATCH is enabled
+        doTestAddNiceApp(TEST_IF_INDEX, IIF_MATCH);
+
+        // HAPPY_BOX_MATCH is already enabled
+        doTestAddNiceApp(NO_IIF, HAPPY_BOX_MATCH | DOZABLE_MATCH);
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testAddNiceAppBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.addNiceApp(TEST_UID));
+    }
+
+    private void doTestUpdateUidLockdownRule(final long iif, final long match, final boolean add)
+            throws Exception {
+        if (match != NO_MATCH) {
+            mUidOwnerMap.updateEntry(new U32(TEST_UID), new UidOwnerValue(iif, match));
+        }
+
+        mBpfNetMaps.updateUidLockdownRule(TEST_UID, add);
+
+        final long expectedMatch = add ? match | LOCKDOWN_VPN_MATCH : match & ~LOCKDOWN_VPN_MATCH;
+        checkUidOwnerValue(TEST_UID, iif, expectedMatch);
+    }
+
+    private static final boolean ADD = true;
+    private static final boolean REMOVE = false;
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testUpdateUidLockdownRuleAddLockdown() throws Exception {
+        doTestUpdateUidLockdownRule(NO_IIF, NO_MATCH, ADD);
+
+        // Other matches are enabled
+        doTestUpdateUidLockdownRule(
+                NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH, ADD);
+
+        // IIF_MATCH is enabled
+        doTestUpdateUidLockdownRule(TEST_IF_INDEX, DOZABLE_MATCH, ADD);
+
+        // LOCKDOWN_VPN_MATCH is already enabled
+        doTestUpdateUidLockdownRule(NO_IIF, LOCKDOWN_VPN_MATCH | DOZABLE_MATCH, ADD);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testUpdateUidLockdownRuleRemoveLockdown() throws Exception {
+        doTestUpdateUidLockdownRule(NO_IIF, LOCKDOWN_VPN_MATCH, REMOVE);
+
+        // LOCKDOWN_VPN_MATCH with other matches
+        doTestUpdateUidLockdownRule(
+                NO_IIF, LOCKDOWN_VPN_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH, REMOVE);
+
+        // LOCKDOWN_VPN_MATCH with IIF_MATCH
+        doTestUpdateUidLockdownRule(TEST_IF_INDEX, LOCKDOWN_VPN_MATCH | IIF_MATCH, REMOVE);
+
+        // LOCKDOWN_VPN_MATCH is not enabled
+        doTestUpdateUidLockdownRule(NO_IIF, POWERSAVE_MATCH | RESTRICTED_MATCH, REMOVE);
+    }
+
+    @Test
+    @IgnoreAfter(Build.VERSION_CODES.S_V2)
+    public void testUpdateUidLockdownRuleBeforeT() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> mBpfNetMaps.updateUidLockdownRule(TEST_UID, true /* add */));
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddUidInterfaceRules() throws Exception {
+        final int uid0 = TEST_UIDS[0];
+        final int uid1 = TEST_UIDS[1];
+
+        mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
+
+        checkUidOwnerValue(uid0, TEST_IF_INDEX, IIF_MATCH);
+        checkUidOwnerValue(uid1, TEST_IF_INDEX, IIF_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddUidInterfaceRulesWithOtherMatch() throws Exception {
+        final int uid0 = TEST_UIDS[0];
+        final int uid1 = TEST_UIDS[1];
+        final long match0 = DOZABLE_MATCH;
+        final long match1 = DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
+        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(NO_IIF, match0));
+        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NO_IIF, match1));
+
+        mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
+
+        checkUidOwnerValue(uid0, TEST_IF_INDEX, match0 | IIF_MATCH);
+        checkUidOwnerValue(uid1, TEST_IF_INDEX, match1 | IIF_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddUidInterfaceRulesWithExistingIifMatch() throws Exception {
+        final int uid0 = TEST_UIDS[0];
+        final int uid1 = TEST_UIDS[1];
+        final long match0 = IIF_MATCH;
+        final long match1 = IIF_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
+        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX + 1, match0));
+        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+
+        mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS);
+
+        checkUidOwnerValue(uid0, TEST_IF_INDEX, match0);
+        checkUidOwnerValue(uid1, TEST_IF_INDEX, match1);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddUidInterfaceRulesGetIfIndexFail() {
+        doReturn(0).when(mDeps).getIfIndex(TEST_IF_NAME);
+        assertThrows(ServiceSpecificException.class,
+                () -> mBpfNetMaps.addUidInterfaceRules(TEST_IF_NAME, TEST_UIDS));
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testAddUidInterfaceRulesWithNullInterface() throws Exception {
+        final int uid0 = TEST_UIDS[0];
+        final int uid1 = TEST_UIDS[1];
+        final long match0 = IIF_MATCH;
+        final long match1 = IIF_MATCH | DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH;
+        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(TEST_IF_INDEX, match0));
+        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(NULL_IIF, match1));
+
+        mBpfNetMaps.addUidInterfaceRules(null /* ifName */, TEST_UIDS);
+
+        checkUidOwnerValue(uid0, NULL_IIF, match0);
+        checkUidOwnerValue(uid1, NULL_IIF, match1);
+    }
+
+    private void doTestRemoveUidInterfaceRules(final long iif0, final long match0,
+            final long iif1, final long match1) throws Exception {
+        final int uid0 = TEST_UIDS[0];
+        final int uid1 = TEST_UIDS[1];
+        mUidOwnerMap.updateEntry(new U32(uid0), new UidOwnerValue(iif0, match0));
+        mUidOwnerMap.updateEntry(new U32(uid1), new UidOwnerValue(iif1, match1));
+
+        mBpfNetMaps.removeUidInterfaceRules(TEST_UIDS);
+
+        checkUidOwnerValue(uid0, NO_IIF, match0 & ~IIF_MATCH);
+        checkUidOwnerValue(uid1, NO_IIF, match1 & ~IIF_MATCH);
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.S_V2)
+    public void testRemoveUidInterfaceRules() throws Exception {
+        doTestRemoveUidInterfaceRules(TEST_IF_INDEX, IIF_MATCH, NULL_IIF, IIF_MATCH);
+
+        // IIF_MATCH and other matches are enabled
+        doTestRemoveUidInterfaceRules(TEST_IF_INDEX, IIF_MATCH | DOZABLE_MATCH,
+                NULL_IIF, IIF_MATCH | DOZABLE_MATCH | RESTRICTED_MATCH);
+
+        // IIF_MATCH is not enabled
+        doTestRemoveUidInterfaceRules(NO_IIF, DOZABLE_MATCH,
+                NO_IIF, DOZABLE_MATCH | POWERSAVE_MATCH | RESTRICTED_MATCH);
+    }
 }
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index b9a18ab..9d11480 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -53,7 +53,6 @@
 import static android.net.ConnectivityManager.EXTRA_NETWORK_INFO;
 import static android.net.ConnectivityManager.EXTRA_NETWORK_TYPE;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_DOZABLE;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOW_POWER_STANDBY;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_1;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_2;
@@ -153,6 +152,8 @@
 import static com.android.server.ConnectivityService.PREFERENCE_ORDER_PROFILE;
 import static com.android.server.ConnectivityService.PREFERENCE_ORDER_VPN;
 import static com.android.server.ConnectivityServiceTestUtils.transportToLegacyType;
+import static com.android.server.NetworkAgentWrapper.CallbackType.OnQosCallbackRegister;
+import static com.android.server.NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister;
 import static com.android.testutils.ConcurrentUtils.await;
 import static com.android.testutils.ConcurrentUtils.durationOf;
 import static com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
@@ -9516,40 +9517,30 @@
         b2.expectBroadcast();
     }
 
-    @Test
+    @Test @IgnoreUpTo(Build.VERSION_CODES.S_V2)
     public void testLockdownSetFirewallUidRule() throws Exception {
-        // For ConnectivityService#setAlwaysOnVpnPackage.
-        mServiceContext.setPermission(
-                Manifest.permission.CONTROL_ALWAYS_ON_VPN, PERMISSION_GRANTED);
-        // Needed to call Vpn#setAlwaysOnPackage.
-        mServiceContext.setPermission(Manifest.permission.CONTROL_VPN, PERMISSION_GRANTED);
-        // Needed to call Vpn#isAlwaysOnPackageSupported.
-        mServiceContext.setPermission(NETWORK_SETTINGS, PERMISSION_GRANTED);
-
+        final Set<Range<Integer>> lockdownRange = UidRange.toIntRanges(Set.of(PRIMARY_UIDRANGE));
         // Enable Lockdown
-        final ArrayList<String> allowList = new ArrayList<>();
-        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, ALWAYS_ON_PACKAGE,
-                true /* lockdown */, allowList);
+        mCm.setRequireVpnForUids(true /* requireVpn */, lockdownRange);
         waitForIdle();
 
         // Lockdown rule is set to apps uids
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_DENY));
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_DENY));
+        verify(mBpfNetMaps, times(3)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP1_UID, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP2_UID, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, true /* add */);
 
         reset(mBpfNetMaps);
 
         // Disable lockdown
-        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, null, false /* lockdown */,
-                allowList);
+        mCm.setRequireVpnForUids(false /* requireVPN */, lockdownRange);
         waitForIdle();
 
         // Lockdown rule is removed from apps uids
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_ALLOW));
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_ALLOW));
+        verify(mBpfNetMaps, times(3)).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP1_UID, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP2_UID, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, false /* add */);
 
         // Interface rules are not changed by Lockdown mode enable/disable
         verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
@@ -10530,69 +10521,67 @@
         assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges("tun0"));
     }
 
+    private void checkInterfaceFilteringRuleWithNullInterface(final LinkProperties lp,
+            final int uid) throws Exception {
+        // The uid range needs to cover the test app so the network is visible to it.
+        final Set<UidRange> vpnRange = Collections.singleton(PRIMARY_UIDRANGE);
+        mMockVpn.establish(lp, uid, vpnRange);
+        assertVpnUidRangesUpdated(true, vpnRange, uid);
+
+        if (SdkLevel.isAtLeastT()) {
+            // On T and above, VPN should have rules for null interface. Null Interface is a
+            // wildcard and this accepts traffic from all the interfaces.
+            // There are two expected invocations, one during the VPN initial
+            // connection, one during the VPN LinkProperties update.
+            ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
+            verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
+                    eq(null) /* iface */, uidCaptor.capture());
+            if (uid == VPN_UID) {
+                assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID);
+                assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID);
+            } else {
+                assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
+                assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
+            }
+            assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
+                    vpnRange);
+
+            mMockVpn.disconnect();
+            waitForIdle();
+
+            // Disconnected VPN should have interface rules removed
+            verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
+            if (uid == VPN_UID) {
+                assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID);
+            } else {
+                assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
+            }
+            assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
+        } else {
+            // Before T, rules are not configured for null interface.
+            verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
+        }
+    }
+
     @Test
-    public void testLegacyVpnSetInterfaceFilteringRuleWithWildcard() throws Exception {
+    public void testLegacyVpnInterfaceFilteringRule() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
-        // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(PRIMARY_UIDRANGE);
-        mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
-        assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
-
-        // A connected Legacy VPN should have interface rules with null interface.
-        // Null Interface is a wildcard and this accepts traffic from all the interfaces.
-        // There are two expected invocations, one during the VPN initial connection,
-        // one during the VPN LinkProperties update.
-        ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
-        verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
-                eq(null) /* iface */, uidCaptor.capture());
-        assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
-        assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
-        assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
-                vpnRange);
-
-        mMockVpn.disconnect();
-        waitForIdle();
-
-        // Disconnected VPN should have interface rules removed
-        verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
-        assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
-        assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
+        // Legacy VPN should have interface filtering with null interface.
+        checkInterfaceFilteringRuleWithNullInterface(lp, Process.SYSTEM_UID);
     }
 
     @Test
-    public void testLocalIpv4OnlyVpnSetInterfaceFilteringRuleWithWildcard() throws Exception {
+    public void testLocalIpv4OnlyVpnInterfaceFilteringRule() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix("192.0.2.0/24"), null, "tun0"));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), RTN_UNREACHABLE));
-        // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(PRIMARY_UIDRANGE);
-        mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
-        assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
-
-        // IPv6 unreachable route should not be misinterpreted as a default route
-        // A connected VPN should have interface rules with null interface.
-        // Null Interface is a wildcard and this accepts traffic from all the interfaces.
-        // There are two expected invocations, one during the VPN initial connection,
-        // one during the VPN LinkProperties update.
-        ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
-        verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
-                eq(null) /* iface */, uidCaptor.capture());
-        assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
-        assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
-        assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
-                vpnRange);
-
-        mMockVpn.disconnect();
-        waitForIdle();
-
-        // Disconnected VPN should have interface rules removed
-        verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
-        assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
-        assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
+        // VPN that does not provide a default route should have interface filtering with null
+        // interface.
+        checkInterfaceFilteringRuleWithNullInterface(lp, VPN_UID);
     }
 
     @Test
@@ -10648,19 +10637,6 @@
     }
 
     @Test
-    public void testStartVpnProfileFromDiffPackage() throws Exception {
-        final String notMyVpnPkg = "com.not.my.vpn";
-        assertThrows(
-                SecurityException.class, () -> mVpnManagerService.startVpnProfile(notMyVpnPkg));
-    }
-
-    @Test
-    public void testStopVpnProfileFromDiffPackage() throws Exception {
-        final String notMyVpnPkg = "com.not.my.vpn";
-        assertThrows(SecurityException.class, () -> mVpnManagerService.stopVpnProfile(notMyVpnPkg));
-    }
-
-    @Test
     public void testUidUpdateChangesInterfaceFilteringRule() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
@@ -11797,6 +11773,12 @@
         mCm.unregisterNetworkCallback(networkCallback);
     }
 
+    private void verifyDump(String[] args) {
+        final StringWriter stringWriter = new StringWriter();
+        mService.dump(new FileDescriptor(), new PrintWriter(stringWriter), args);
+        assertFalse(stringWriter.toString().isEmpty());
+    }
+
     @Test
     public void testDumpDoesNotCrash() {
         mServiceContext.setPermission(DUMP, PERMISSION_GRANTED);
@@ -11809,11 +11791,26 @@
                 .addTransportType(TRANSPORT_WIFI).build();
         mCm.registerNetworkCallback(genericRequest, genericNetworkCallback);
         mCm.registerNetworkCallback(wifiRequest, wifiNetworkCallback);
-        final StringWriter stringWriter = new StringWriter();
 
-        mService.dump(new FileDescriptor(), new PrintWriter(stringWriter), new String[0]);
+        verifyDump(new String[0]);
 
-        assertFalse(stringWriter.toString().isEmpty());
+        // Verify dump with arguments.
+        final String dumpPrio = "--dump-priority";
+        final String[] dumpArgs = {dumpPrio};
+        verifyDump(dumpArgs);
+
+        final String[] highDumpArgs = {dumpPrio, "HIGH"};
+        verifyDump(highDumpArgs);
+
+        final String[] normalDumpArgs = {dumpPrio, "NORMAL"};
+        verifyDump(normalDumpArgs);
+
+        // Invalid args should do dumpNormal w/o exception
+        final String[] unknownDumpArgs = {dumpPrio, "UNKNOWN"};
+        verifyDump(unknownDumpArgs);
+
+        final String[] invalidDumpArgs = {"UNKNOWN"};
+        verifyDump(invalidDumpArgs);
     }
 
     @Test
@@ -12157,16 +12154,14 @@
         mQosCallbackMockHelper.registerQosCallback(
                 mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
 
-        final NetworkAgentWrapper.CallbackType.OnQosCallbackRegister cbRegister1 =
-                (NetworkAgentWrapper.CallbackType.OnQosCallbackRegister)
-                        wrapper.getCallbackHistory().poll(1000, x -> true);
+        final OnQosCallbackRegister cbRegister1 =
+                (OnQosCallbackRegister) wrapper.getCallbackHistory().poll(1000, x -> true);
         assertNotNull(cbRegister1);
 
         final int registerCallbackId = cbRegister1.mQosCallbackId;
         mService.unregisterQosCallback(mQosCallbackMockHelper.mCallback);
-        final NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister cbUnregister;
-        cbUnregister = (NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister)
-                wrapper.getCallbackHistory().poll(1000, x -> true);
+        final OnQosCallbackUnregister cbUnregister =
+                (OnQosCallbackUnregister) wrapper.getCallbackHistory().poll(1000, x -> true);
         assertNotNull(cbUnregister);
         assertEquals(registerCallbackId, cbUnregister.mQosCallbackId);
         assertNull(wrapper.getCallbackHistory().poll(200, x -> true));
@@ -12245,6 +12240,86 @@
                         && session.getSessionType() == QosSession.TYPE_NR_BEARER));
     }
 
+    @Test @IgnoreUpTo(SC_V2)
+    public void testQosCallbackAvailableOnValidationError() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+        final NetworkAgentWrapper wrapper = mQosCallbackMockHelper.mAgentWrapper;
+        final int sessionId = 10;
+        final int qosCallbackId = 1;
+
+        doReturn(QosCallbackException.EX_TYPE_FILTER_NONE)
+                .when(mQosCallbackMockHelper.mFilter).validate();
+        mQosCallbackMockHelper.registerQosCallback(
+                mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
+        OnQosCallbackRegister cbRegister1 =
+                (OnQosCallbackRegister) wrapper.getCallbackHistory().poll(1000, x -> true);
+        assertNotNull(cbRegister1);
+        final int registerCallbackId = cbRegister1.mQosCallbackId;
+
+        waitForIdle();
+
+        doReturn(QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED)
+                .when(mQosCallbackMockHelper.mFilter).validate();
+        final EpsBearerQosSessionAttributes attributes = new EpsBearerQosSessionAttributes(
+                1, 2, 3, 4, 5, new ArrayList<>());
+        mQosCallbackMockHelper.mAgentWrapper.getNetworkAgent()
+                .sendQosSessionAvailable(qosCallbackId, sessionId, attributes);
+        waitForIdle();
+
+        final NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister cbUnregister;
+        cbUnregister = (NetworkAgentWrapper.CallbackType.OnQosCallbackUnregister)
+                wrapper.getCallbackHistory().poll(1000, x -> true);
+        assertNotNull(cbUnregister);
+        assertEquals(registerCallbackId, cbUnregister.mQosCallbackId);
+        waitForIdle();
+        verify(mQosCallbackMockHelper.mCallback)
+                .onError(eq(QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED));
+    }
+
+    @Test @IgnoreUpTo(SC_V2)
+    public void testQosCallbackLostOnValidationError() throws Exception {
+        mQosCallbackMockHelper = new QosCallbackMockHelper();
+        final int sessionId = 10;
+        final int qosCallbackId = 1;
+
+        doReturn(QosCallbackException.EX_TYPE_FILTER_NONE)
+                .when(mQosCallbackMockHelper.mFilter).validate();
+        mQosCallbackMockHelper.registerQosCallback(
+                mQosCallbackMockHelper.mFilter, mQosCallbackMockHelper.mCallback);
+        waitForIdle();
+        EpsBearerQosSessionAttributes attributes =
+                sendQosSessionEvent(qosCallbackId, sessionId, true);
+        waitForIdle();
+
+        verify(mQosCallbackMockHelper.mCallback).onQosEpsBearerSessionAvailable(argThat(session ->
+                session.getSessionId() == sessionId
+                        && session.getSessionType() == QosSession.TYPE_EPS_BEARER), eq(attributes));
+
+        doReturn(QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED)
+                .when(mQosCallbackMockHelper.mFilter).validate();
+
+        sendQosSessionEvent(qosCallbackId, sessionId, false);
+        waitForIdle();
+        verify(mQosCallbackMockHelper.mCallback)
+                .onError(eq(QosCallbackException.EX_TYPE_FILTER_SOCKET_REMOTE_ADDRESS_CHANGED));
+    }
+
+    private EpsBearerQosSessionAttributes sendQosSessionEvent(
+            int qosCallbackId, int sessionId, boolean available) {
+        if (available) {
+            final EpsBearerQosSessionAttributes attributes = new EpsBearerQosSessionAttributes(
+                    1, 2, 3, 4, 5, new ArrayList<>());
+            mQosCallbackMockHelper.mAgentWrapper.getNetworkAgent()
+                    .sendQosSessionAvailable(qosCallbackId, sessionId, attributes);
+            return attributes;
+        } else {
+            mQosCallbackMockHelper.mAgentWrapper.getNetworkAgent()
+                    .sendQosSessionLost(qosCallbackId, sessionId, QosSession.TYPE_EPS_BEARER);
+            return null;
+        }
+
+    }
+
     @Test
     public void testQosCallbackTooManyRequests() throws Exception {
         mQosCallbackMockHelper = new QosCallbackMockHelper();
diff --git a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
index 45f3d3c..9401d47 100644
--- a/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
+++ b/tests/unit/java/com/android/server/IpSecServiceParameterizedTest.java
@@ -89,7 +89,7 @@
 public class IpSecServiceParameterizedTest {
     @Rule
     public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule(
-            Build.VERSION_CODES.R /* ignoreClassUpTo */);
+            Build.VERSION_CODES.S_V2 /* ignoreClassUpTo */);
 
     private static final int TEST_SPI = 0xD1201D;
 
@@ -783,6 +783,23 @@
     }
 
     @Test
+    public void testSetNetworkForTunnelInterfaceFailsForNullLp() throws Exception {
+        final IpSecTunnelInterfaceResponse createTunnelResp =
+                createAndValidateTunnel(mSourceAddr, mDestinationAddr, BLESSED_PACKAGE);
+        final Network newFakeNetwork = new Network(1000);
+        final int tunnelIfaceResourceId = createTunnelResp.resourceId;
+
+        try {
+            mIpSecService.setNetworkForTunnelInterface(
+                    tunnelIfaceResourceId, newFakeNetwork, BLESSED_PACKAGE);
+            fail(
+                    "Expected an IllegalArgumentException for underlying network with null"
+                            + " LinkProperties");
+        } catch (IllegalArgumentException expected) {
+        }
+    }
+
+    @Test
     public void testSetNetworkForTunnelInterfaceFailsForInvalidResourceId() throws Exception {
         final IpSecTunnelInterfaceResponse createTunnelResp =
                 createAndValidateTunnel(mSourceAddr, mDestinationAddr, BLESSED_PACKAGE);
diff --git a/tests/unit/java/com/android/server/IpSecServiceRefcountedResourceTest.java b/tests/unit/java/com/android/server/IpSecServiceRefcountedResourceTest.java
index 5c7ca6f..8595ab9 100644
--- a/tests/unit/java/com/android/server/IpSecServiceRefcountedResourceTest.java
+++ b/tests/unit/java/com/android/server/IpSecServiceRefcountedResourceTest.java
@@ -54,7 +54,7 @@
 /** Unit tests for {@link IpSecService.RefcountedResource}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecServiceRefcountedResourceTest {
     Context mMockContext;
     IpSecService.Dependencies mMockDeps;
diff --git a/tests/unit/java/com/android/server/IpSecServiceTest.java b/tests/unit/java/com/android/server/IpSecServiceTest.java
index 7e6b157..6955620 100644
--- a/tests/unit/java/com/android/server/IpSecServiceTest.java
+++ b/tests/unit/java/com/android/server/IpSecServiceTest.java
@@ -75,7 +75,7 @@
 /** Unit tests for {@link IpSecService}. */
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpSecServiceTest {
 
     private static final int DROID_SPI = 0xD1201D;
diff --git a/tests/unit/java/com/android/server/NsdServiceTest.java b/tests/unit/java/com/android/server/NsdServiceTest.java
index ed9e930..58d002a 100644
--- a/tests/unit/java/com/android/server/NsdServiceTest.java
+++ b/tests/unit/java/com/android/server/NsdServiceTest.java
@@ -25,6 +25,7 @@
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.doCallRealMethod;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
@@ -83,12 +84,17 @@
 //  - test NSD_ON ENABLE/DISABLED listening
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class NsdServiceTest {
-
     static final int PROTOCOL = NsdManager.PROTOCOL_DNS_SD;
     private static final long CLEANUP_DELAY_MS = 500;
     private static final long TIMEOUT_MS = 500;
+    private static final String SERVICE_NAME = "a_name";
+    private static final String SERVICE_TYPE = "a_type";
+    private static final String SERVICE_FULL_NAME = SERVICE_NAME + "." + SERVICE_TYPE;
+    private static final String DOMAIN_NAME = "mytestdevice.local";
+    private static final int PORT = 2201;
+    private static final int IFACE_IDX_ANY = 0;
 
     // Records INsdManagerCallback created when NsdService#connect is called.
     // Only accessed on the test thread, since NsdService#connect is called by the NsdManager
@@ -102,6 +108,7 @@
     @Mock MDnsManager mMockMDnsM;
     HandlerThread mThread;
     TestHandler mHandler;
+    NsdService mService;
 
     private static class LinkToDeathRecorder extends Binder {
         IBinder.DeathRecipient mDr;
@@ -123,12 +130,18 @@
         doReturn(MDnsManager.MDNS_SERVICE).when(mContext)
                 .getSystemServiceName(MDnsManager.class);
         doReturn(mMockMDnsM).when(mContext).getSystemService(MDnsManager.MDNS_SERVICE);
+        if (mContext.getSystemService(MDnsManager.class) == null) {
+            // Test is using mockito-extended
+            doCallRealMethod().when(mContext).getSystemService(MDnsManager.class);
+        }
         doReturn(true).when(mMockMDnsM).registerService(
                 anyInt(), anyString(), anyString(), anyInt(), any(), anyInt());
         doReturn(true).when(mMockMDnsM).stopOperation(anyInt());
         doReturn(true).when(mMockMDnsM).discover(anyInt(), anyString(), anyInt());
         doReturn(true).when(mMockMDnsM).resolve(
                 anyInt(), anyString(), anyString(), anyString(), anyInt());
+
+        mService = makeService();
     }
 
     @After
@@ -142,18 +155,14 @@
     @Test
     @DisableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
     public void testPreSClients() throws Exception {
-        NsdService service = makeService();
-
         // Pre S client connected, the daemon should be started.
-        connectClient(service);
-        waitForIdle();
+        connectClient(mService);
         final INsdManagerCallback cb1 = getCallback();
         final IBinder.DeathRecipient deathRecipient1 = verifyLinkToDeath(cb1);
         verify(mMockMDnsM, times(1)).registerEventListener(any());
         verify(mMockMDnsM, times(1)).startDaemon();
 
-        connectClient(service);
-        waitForIdle();
+        connectClient(mService);
         final INsdManagerCallback cb2 = getCallback();
         final IBinder.DeathRecipient deathRecipient2 = verifyLinkToDeath(cb2);
         // Daemon has been started, it should not try to start it again.
@@ -173,19 +182,15 @@
     @Test
     @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
     public void testNoDaemonStartedWhenClientsConnect() throws Exception {
-        final NsdService service = makeService();
-
         // Creating an NsdManager will not cause daemon startup.
-        connectClient(service);
-        waitForIdle();
+        connectClient(mService);
         verify(mMockMDnsM, never()).registerEventListener(any());
         verify(mMockMDnsM, never()).startDaemon();
         final INsdManagerCallback cb1 = getCallback();
         final IBinder.DeathRecipient deathRecipient1 = verifyLinkToDeath(cb1);
 
         // Creating another NsdManager will not cause daemon startup either.
-        connectClient(service);
-        waitForIdle();
+        connectClient(mService);
         verify(mMockMDnsM, never()).registerEventListener(any());
         verify(mMockMDnsM, never()).startDaemon();
         final INsdManagerCallback cb2 = getCallback();
@@ -211,70 +216,66 @@
     @Test
     @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
     public void testClientRequestsAreGCedAtDisconnection() throws Exception {
-        NsdService service = makeService();
-
-        NsdManager client = connectClient(service);
-        waitForIdle();
+        final NsdManager client = connectClient(mService);
         final INsdManagerCallback cb1 = getCallback();
         final IBinder.DeathRecipient deathRecipient = verifyLinkToDeath(cb1);
         verify(mMockMDnsM, never()).registerEventListener(any());
         verify(mMockMDnsM, never()).startDaemon();
 
-        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
-        request.setPort(2201);
+        final NsdServiceInfo request = new NsdServiceInfo(SERVICE_NAME, SERVICE_TYPE);
+        request.setPort(PORT);
 
         // Client registration request
         NsdManager.RegistrationListener listener1 = mock(NsdManager.RegistrationListener.class);
         client.registerService(request, PROTOCOL, listener1);
         waitForIdle();
-        verify(mMockMDnsM, times(1)).registerEventListener(any());
-        verify(mMockMDnsM, times(1)).startDaemon();
-        verify(mMockMDnsM, times(1)).registerService(
-                eq(2), eq("a_name"), eq("a_type"), eq(2201), any(), eq(0));
+        verify(mMockMDnsM).registerEventListener(any());
+        verify(mMockMDnsM).startDaemon();
+        verify(mMockMDnsM).registerService(
+                eq(2), eq(SERVICE_NAME), eq(SERVICE_TYPE), eq(PORT), any(), eq(IFACE_IDX_ANY));
 
         // Client discovery request
         NsdManager.DiscoveryListener listener2 = mock(NsdManager.DiscoveryListener.class);
-        client.discoverServices("a_type", PROTOCOL, listener2);
+        client.discoverServices(SERVICE_TYPE, PROTOCOL, listener2);
         waitForIdle();
-        verify(mMockMDnsM, times(1)).discover(eq(3), eq("a_type"), eq(0));
+        verify(mMockMDnsM).discover(3 /* id */, SERVICE_TYPE, IFACE_IDX_ANY);
 
         // Client resolve request
         NsdManager.ResolveListener listener3 = mock(NsdManager.ResolveListener.class);
         client.resolveService(request, listener3);
         waitForIdle();
-        verify(mMockMDnsM, times(1)).resolve(
-                eq(4), eq("a_name"), eq("a_type"), eq("local."), eq(0));
+        verify(mMockMDnsM).resolve(
+                4 /* id */, SERVICE_NAME, SERVICE_TYPE, "local." /* domain */, IFACE_IDX_ANY);
 
         // Client disconnects, stop the daemon after CLEANUP_DELAY_MS.
         deathRecipient.binderDied();
         verifyDelayMaybeStopDaemon(CLEANUP_DELAY_MS);
         // checks that request are cleaned
-        verify(mMockMDnsM, times(1)).stopOperation(eq(2));
-        verify(mMockMDnsM, times(1)).stopOperation(eq(3));
-        verify(mMockMDnsM, times(1)).stopOperation(eq(4));
+        verify(mMockMDnsM).stopOperation(2 /* id */);
+        verify(mMockMDnsM).stopOperation(3 /* id */);
+        verify(mMockMDnsM).stopOperation(4 /* id */);
     }
 
     @Test
     @EnableCompatChanges(NsdManager.RUN_NATIVE_NSD_ONLY_IF_LEGACY_APPS)
     public void testCleanupDelayNoRequestActive() throws Exception {
-        NsdService service = makeService();
-        NsdManager client = connectClient(service);
+        final NsdManager client = connectClient(mService);
 
-        NsdServiceInfo request = new NsdServiceInfo("a_name", "a_type");
-        request.setPort(2201);
+        final NsdServiceInfo request = new NsdServiceInfo(SERVICE_NAME, SERVICE_TYPE);
+        request.setPort(PORT);
         NsdManager.RegistrationListener listener1 = mock(NsdManager.RegistrationListener.class);
         client.registerService(request, PROTOCOL, listener1);
         waitForIdle();
-        verify(mMockMDnsM, times(1)).registerEventListener(any());
-        verify(mMockMDnsM, times(1)).startDaemon();
+        verify(mMockMDnsM).registerEventListener(any());
+        verify(mMockMDnsM).startDaemon();
         final INsdManagerCallback cb1 = getCallback();
         final IBinder.DeathRecipient deathRecipient = verifyLinkToDeath(cb1);
-        verify(mMockMDnsM, times(1)).registerService(
-                eq(2), eq("a_name"), eq("a_type"), eq(2201), any(), eq(0));
+        verify(mMockMDnsM).registerService(
+                eq(2), eq(SERVICE_NAME), eq(SERVICE_TYPE), eq(PORT), any(), eq(IFACE_IDX_ANY));
 
         client.unregisterService(listener1);
         waitForIdle();
-        verify(mMockMDnsM, times(1)).stopOperation(eq(2));
+        verify(mMockMDnsM).stopOperation(2 /* id */);
 
         verifyDelayMaybeStopDaemon(CLEANUP_DELAY_MS);
         reset(mMockMDnsM);
@@ -286,33 +287,28 @@
 
     @Test
     public void testDiscoverOnTetheringDownstream() throws Exception {
-        NsdService service = makeService();
-        NsdManager client = connectClient(service);
-
-        final String serviceType = "a_type";
-        final String serviceName = "a_name";
-        final String domainName = "mytestdevice.local";
+        final NsdManager client = connectClient(mService);
         final int interfaceIdx = 123;
         final NsdManager.DiscoveryListener discListener = mock(NsdManager.DiscoveryListener.class);
-        client.discoverServices(serviceType, NsdManager.PROTOCOL_DNS_SD, discListener);
+        client.discoverServices(SERVICE_TYPE, PROTOCOL, discListener);
         waitForIdle();
 
         final ArgumentCaptor<IMDnsEventListener> listenerCaptor =
                 ArgumentCaptor.forClass(IMDnsEventListener.class);
         verify(mMockMDnsM).registerEventListener(listenerCaptor.capture());
         final ArgumentCaptor<Integer> discIdCaptor = ArgumentCaptor.forClass(Integer.class);
-        verify(mMockMDnsM).discover(discIdCaptor.capture(), eq(serviceType),
+        verify(mMockMDnsM).discover(discIdCaptor.capture(), eq(SERVICE_TYPE),
                 eq(0) /* interfaceIdx */);
         // NsdManager uses a separate HandlerThread to dispatch callbacks (on ServiceHandler), so
         // this needs to use a timeout
-        verify(discListener, timeout(TIMEOUT_MS)).onDiscoveryStarted(serviceType);
+        verify(discListener, timeout(TIMEOUT_MS)).onDiscoveryStarted(SERVICE_TYPE);
 
         final DiscoveryInfo discoveryInfo = new DiscoveryInfo(
                 discIdCaptor.getValue(),
                 IMDnsEventListener.SERVICE_FOUND,
-                serviceName,
-                serviceType,
-                domainName,
+                SERVICE_NAME,
+                SERVICE_TYPE,
+                DOMAIN_NAME,
                 interfaceIdx,
                 INetd.LOCAL_NET_ID); // LOCAL_NET_ID (99) used on tethering downstreams
         final IMDnsEventListener eventListener = listenerCaptor.getValue();
@@ -323,8 +319,8 @@
                 ArgumentCaptor.forClass(NsdServiceInfo.class);
         verify(discListener, timeout(TIMEOUT_MS)).onServiceFound(discoveredInfoCaptor.capture());
         final NsdServiceInfo foundInfo = discoveredInfoCaptor.getValue();
-        assertEquals(serviceName, foundInfo.getServiceName());
-        assertEquals(serviceType, foundInfo.getServiceType());
+        assertEquals(SERVICE_NAME, foundInfo.getServiceName());
+        assertEquals(SERVICE_TYPE, foundInfo.getServiceType());
         assertNull(foundInfo.getHost());
         assertNull(foundInfo.getNetwork());
         assertEquals(interfaceIdx, foundInfo.getInterfaceIndex());
@@ -335,19 +331,18 @@
         waitForIdle();
 
         final ArgumentCaptor<Integer> resolvIdCaptor = ArgumentCaptor.forClass(Integer.class);
-        verify(mMockMDnsM).resolve(resolvIdCaptor.capture(), eq(serviceName), eq(serviceType),
+        verify(mMockMDnsM).resolve(resolvIdCaptor.capture(), eq(SERVICE_NAME), eq(SERVICE_TYPE),
                 eq("local.") /* domain */, eq(interfaceIdx));
 
         final int servicePort = 10123;
-        final String serviceFullName = serviceName + "." + serviceType;
         final ResolutionInfo resolutionInfo = new ResolutionInfo(
                 resolvIdCaptor.getValue(),
                 IMDnsEventListener.SERVICE_RESOLVED,
                 null /* serviceName */,
                 null /* serviceType */,
                 null /* domain */,
-                serviceFullName,
-                domainName,
+                SERVICE_FULL_NAME,
+                DOMAIN_NAME,
                 servicePort,
                 new byte[0] /* txtRecord */,
                 interfaceIdx);
@@ -357,14 +352,14 @@
         waitForIdle();
 
         final ArgumentCaptor<Integer> getAddrIdCaptor = ArgumentCaptor.forClass(Integer.class);
-        verify(mMockMDnsM).getServiceAddress(getAddrIdCaptor.capture(), eq(domainName),
+        verify(mMockMDnsM).getServiceAddress(getAddrIdCaptor.capture(), eq(DOMAIN_NAME),
                 eq(interfaceIdx));
 
         final String serviceAddress = "192.0.2.123";
         final GetAddressInfo addressInfo = new GetAddressInfo(
                 getAddrIdCaptor.getValue(),
                 IMDnsEventListener.SERVICE_GET_ADDR_SUCCESS,
-                serviceFullName,
+                SERVICE_FULL_NAME,
                 serviceAddress,
                 interfaceIdx,
                 INetd.LOCAL_NET_ID);
@@ -375,8 +370,8 @@
                 ArgumentCaptor.forClass(NsdServiceInfo.class);
         verify(resolveListener, timeout(TIMEOUT_MS)).onServiceResolved(resInfoCaptor.capture());
         final NsdServiceInfo resolvedService = resInfoCaptor.getValue();
-        assertEquals(serviceName, resolvedService.getServiceName());
-        assertEquals("." + serviceType, resolvedService.getServiceType());
+        assertEquals(SERVICE_NAME, resolvedService.getServiceName());
+        assertEquals("." + SERVICE_TYPE, resolvedService.getServiceType());
         assertEquals(InetAddresses.parseNumericAddress(serviceAddress), resolvedService.getHost());
         assertEquals(servicePort, resolvedService.getPort());
         assertNull(resolvedService.getNetwork());
@@ -410,7 +405,10 @@
     }
 
     NsdManager connectClient(NsdService service) {
-        return new NsdManager(mContext, service);
+        final NsdManager nsdManager = new NsdManager(mContext, service);
+        // Wait for client registration done.
+        waitForIdle();
+        return nsdManager;
     }
 
     void verifyDelayMaybeStopDaemon(long cleanupDelayMs) throws Exception {
diff --git a/tests/unit/java/com/android/server/VpnManagerServiceTest.java b/tests/unit/java/com/android/server/VpnManagerServiceTest.java
new file mode 100644
index 0000000..c814cc5
--- /dev/null
+++ b/tests/unit/java/com/android/server/VpnManagerServiceTest.java
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import static android.os.Build.VERSION_CODES.R;
+
+import static com.android.testutils.ContextUtils.mockService;
+import static com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
+import static com.android.testutils.MiscAsserts.assertThrows;
+
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.annotation.UserIdInt;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.ConnectivityManager;
+import android.net.INetd;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.INetworkManagementService;
+import android.os.Looper;
+import android.os.UserHandle;
+import android.os.UserManager;
+
+import androidx.test.filters.SmallTest;
+
+import com.android.server.connectivity.Vpn;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+import com.android.testutils.HandlerUtils;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+@RunWith(DevSdkIgnoreRunner.class)
+@IgnoreUpTo(R) // VpnManagerService is not available before R
+@SmallTest
+public class VpnManagerServiceTest extends VpnTestBase {
+    @Rule
+    public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
+
+    private static final int TIMEOUT_MS = 2_000;
+
+    @Mock Context mContext;
+    @Mock Context mSystemContext;
+    @Mock Context mUserAllContext;
+    private HandlerThread mHandlerThread;
+    @Mock private Vpn mVpn;
+    @Mock private INetworkManagementService mNms;
+    @Mock private ConnectivityManager mCm;
+    @Mock private UserManager mUserManager;
+    @Mock private INetd mNetd;
+    @Mock private PackageManager mPackageManager;
+
+    private VpnManagerServiceDependencies mDeps;
+    private VpnManagerService mService;
+    private BroadcastReceiver mUserPresentReceiver;
+    private BroadcastReceiver mIntentReceiver;
+    private final String mNotMyVpnPkg = "com.not.my.vpn";
+
+    class VpnManagerServiceDependencies extends VpnManagerService.Dependencies {
+        @Override
+        public HandlerThread makeHandlerThread() {
+            return mHandlerThread;
+        }
+
+        @Override
+        public INetworkManagementService getINetworkManagementService() {
+            return mNms;
+        }
+
+        @Override
+        public INetd getNetd() {
+            return mNetd;
+        }
+
+        @Override
+        public Vpn createVpn(Looper looper, Context context, INetworkManagementService nms,
+                INetd netd, @UserIdInt int userId) {
+            return mVpn;
+        }
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        mHandlerThread = new HandlerThread("TestVpnManagerService");
+        mDeps = new VpnManagerServiceDependencies();
+        doReturn(mUserAllContext).when(mContext).createContextAsUser(UserHandle.ALL, 0);
+        doReturn(mSystemContext).when(mContext).createContextAsUser(UserHandle.SYSTEM, 0);
+        doReturn(mPackageManager).when(mContext).getPackageManager();
+        setMockedPackages(mPackageManager, sPackages);
+
+        mockService(mContext, ConnectivityManager.class, Context.CONNECTIVITY_SERVICE, mCm);
+        mockService(mContext, UserManager.class, Context.USER_SERVICE, mUserManager);
+        doReturn(SYSTEM_USER).when(mUserManager).getUserInfo(eq(SYSTEM_USER_ID));
+
+        mService = new VpnManagerService(mContext, mDeps);
+        mService.systemReady();
+
+        final ArgumentCaptor<BroadcastReceiver> intentReceiverCaptor =
+                ArgumentCaptor.forClass(BroadcastReceiver.class);
+        final ArgumentCaptor<BroadcastReceiver> userPresentReceiverCaptor =
+                ArgumentCaptor.forClass(BroadcastReceiver.class);
+        verify(mSystemContext).registerReceiver(
+                userPresentReceiverCaptor.capture(), any(), any(), any());
+        verify(mUserAllContext, times(2)).registerReceiver(
+                intentReceiverCaptor.capture(), any(), any(), any());
+        mUserPresentReceiver = userPresentReceiverCaptor.getValue();
+        mIntentReceiver = intentReceiverCaptor.getValue();
+
+        // Add user to create vpn in mVpn
+        onUserStarted(SYSTEM_USER_ID);
+        assertNotNull(mService.mVpns.get(SYSTEM_USER_ID));
+    }
+
+    @Test
+    public void testUpdateAppExclusionList() {
+        // Start vpn
+        mService.startVpnProfile(TEST_VPN_PKG);
+        verify(mVpn).startVpnProfile(eq(TEST_VPN_PKG));
+
+        // Remove package due to package replaced.
+        onPackageRemoved(PKGS[0], PKG_UIDS[0], true /* isReplacing */);
+        verify(mVpn, never()).refreshPlatformVpnAppExclusionList();
+
+        // Add package due to package replaced.
+        onPackageAdded(PKGS[0], PKG_UIDS[0], true /* isReplacing */);
+        verify(mVpn, never()).refreshPlatformVpnAppExclusionList();
+
+        // Remove package
+        onPackageRemoved(PKGS[0], PKG_UIDS[0], false /* isReplacing */);
+        verify(mVpn).refreshPlatformVpnAppExclusionList();
+
+        // Add the package back
+        onPackageAdded(PKGS[0], PKG_UIDS[0], false /* isReplacing */);
+        verify(mVpn, times(2)).refreshPlatformVpnAppExclusionList();
+    }
+
+    @Test
+    public void testStartVpnProfileFromDiffPackage() {
+        assertThrows(
+                SecurityException.class, () -> mService.startVpnProfile(mNotMyVpnPkg));
+    }
+
+    @Test
+    public void testStopVpnProfileFromDiffPackage() {
+        assertThrows(SecurityException.class, () -> mService.stopVpnProfile(mNotMyVpnPkg));
+    }
+
+    @Test
+    public void testGetProvisionedVpnProfileStateFromDiffPackage() {
+        assertThrows(SecurityException.class, () ->
+                mService.getProvisionedVpnProfileState(mNotMyVpnPkg));
+    }
+
+    @Test
+    public void testGetProvisionedVpnProfileState() {
+        mService.getProvisionedVpnProfileState(TEST_VPN_PKG);
+        verify(mVpn).getProvisionedVpnProfileState(TEST_VPN_PKG);
+    }
+
+    private Intent buildIntent(String action, String packageName, int userId, int uid,
+            boolean isReplacing) {
+        final Intent intent = new Intent(action);
+        intent.putExtra(Intent.EXTRA_USER_HANDLE, userId);
+        intent.putExtra(Intent.EXTRA_UID, uid);
+        intent.putExtra(Intent.EXTRA_REPLACING, isReplacing);
+        if (packageName != null) {
+            intent.setData(Uri.fromParts("package" /* scheme */, packageName, null /* fragment */));
+        }
+
+        return intent;
+    }
+
+    private void sendIntent(Intent intent) {
+        final Handler h = mHandlerThread.getThreadHandler();
+
+        // Send in handler thread.
+        h.post(() -> mIntentReceiver.onReceive(mContext, intent));
+        HandlerUtils.waitForIdle(mHandlerThread, TIMEOUT_MS);
+    }
+
+    private void onUserStarted(int userId) {
+        sendIntent(buildIntent(Intent.ACTION_USER_STARTED,
+                null /* packageName */, userId, -1 /* uid */, false /* isReplacing */));
+    }
+
+    private void onPackageAdded(String packageName, int userId, int uid, boolean isReplacing) {
+        sendIntent(buildIntent(Intent.ACTION_PACKAGE_ADDED, packageName, userId, uid, isReplacing));
+    }
+
+    private void onPackageAdded(String packageName, int uid, boolean isReplacing) {
+        onPackageAdded(packageName, UserHandle.USER_SYSTEM, uid, isReplacing);
+    }
+
+    private void onPackageRemoved(String packageName, int userId, int uid, boolean isReplacing) {
+        sendIntent(buildIntent(Intent.ACTION_PACKAGE_REMOVED, packageName, userId, uid,
+                isReplacing));
+    }
+
+    private void onPackageRemoved(String packageName, int uid, boolean isReplacing) {
+        onPackageRemoved(packageName, UserHandle.USER_SYSTEM, uid, isReplacing);
+    }
+
+    @Test
+    public void testReceiveIntentFromNonHandlerThread() {
+        assertThrows(IllegalStateException.class, () ->
+                mIntentReceiver.onReceive(mContext, buildIntent(Intent.ACTION_PACKAGE_REMOVED,
+                        PKGS[0], UserHandle.USER_SYSTEM, PKG_UIDS[0], true /* isReplacing */)));
+
+        assertThrows(IllegalStateException.class, () ->
+                mUserPresentReceiver.onReceive(mContext, new Intent(Intent.ACTION_USER_PRESENT)));
+    }
+}
diff --git a/tests/unit/java/com/android/server/VpnTestBase.java b/tests/unit/java/com/android/server/VpnTestBase.java
new file mode 100644
index 0000000..6113872
--- /dev/null
+++ b/tests/unit/java/com/android/server/VpnTestBase.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server;
+
+import static android.content.pm.UserInfo.FLAG_ADMIN;
+import static android.content.pm.UserInfo.FLAG_MANAGED_PROFILE;
+import static android.content.pm.UserInfo.FLAG_PRIMARY;
+import static android.content.pm.UserInfo.FLAG_RESTRICTED;
+
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doAnswer;
+
+import android.content.pm.PackageManager;
+import android.content.pm.UserInfo;
+import android.os.Process;
+import android.os.UserHandle;
+import android.util.ArrayMap;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+/** Common variables or methods shared between VpnTest and VpnManagerServiceTest. */
+public class VpnTestBase {
+    protected static final String TEST_VPN_PKG = "com.testvpn.vpn";
+    /**
+     * Names and UIDs for some fake packages. Important points:
+     *  - UID is ordered increasing.
+     *  - One pair of packages have consecutive UIDs.
+     */
+    protected static final String[] PKGS = {"com.example", "org.example", "net.example", "web.vpn"};
+    protected static final int[] PKG_UIDS = {10066, 10077, 10078, 10400};
+    // Mock packages
+    protected static final Map<String, Integer> sPackages = new ArrayMap<>();
+    static {
+        for (int i = 0; i < PKGS.length; i++) {
+            sPackages.put(PKGS[i], PKG_UIDS[i]);
+        }
+        sPackages.put(TEST_VPN_PKG, Process.myUid());
+    }
+
+    // Mock users
+    protected static final int SYSTEM_USER_ID = 0;
+    protected static final UserInfo SYSTEM_USER = new UserInfo(0, "system", UserInfo.FLAG_PRIMARY);
+    protected static final UserInfo PRIMARY_USER = new UserInfo(27, "Primary",
+            FLAG_ADMIN | FLAG_PRIMARY);
+    protected static final UserInfo SECONDARY_USER = new UserInfo(15, "Secondary", FLAG_ADMIN);
+    protected static final UserInfo RESTRICTED_PROFILE_A = new UserInfo(40, "RestrictedA",
+            FLAG_RESTRICTED);
+    protected static final UserInfo RESTRICTED_PROFILE_B = new UserInfo(42, "RestrictedB",
+            FLAG_RESTRICTED);
+    protected static final UserInfo MANAGED_PROFILE_A = new UserInfo(45, "ManagedA",
+            FLAG_MANAGED_PROFILE);
+    static {
+        RESTRICTED_PROFILE_A.restrictedProfileParentId = PRIMARY_USER.id;
+        RESTRICTED_PROFILE_B.restrictedProfileParentId = SECONDARY_USER.id;
+        MANAGED_PROFILE_A.profileGroupId = PRIMARY_USER.id;
+    }
+
+    // Populate a fake packageName-to-UID mapping.
+    protected void setMockedPackages(PackageManager mockPm, final Map<String, Integer> packages) {
+        try {
+            doAnswer(invocation -> {
+                final String appName = (String) invocation.getArguments()[0];
+                final int userId = (int) invocation.getArguments()[1];
+
+                final Integer appId = packages.get(appName);
+                if (appId == null) {
+                    throw new PackageManager.NameNotFoundException(appName);
+                }
+
+                return UserHandle.getUid(userId, appId);
+            }).when(mockPm).getPackageUidAsUser(anyString(), anyInt());
+        } catch (Exception e) {
+        }
+    }
+
+    protected List<Integer> toList(int[] arr) {
+        return Arrays.stream(arr).boxed().collect(Collectors.toList());
+    }
+}
diff --git a/tests/unit/java/com/android/server/connectivity/ClatCoordinatorTest.java b/tests/unit/java/com/android/server/connectivity/ClatCoordinatorTest.java
index f84d10f..feee293 100644
--- a/tests/unit/java/com/android/server/connectivity/ClatCoordinatorTest.java
+++ b/tests/unit/java/com/android/server/connectivity/ClatCoordinatorTest.java
@@ -30,12 +30,16 @@
 import static com.android.testutils.MiscAsserts.assertThrows;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.fail;
 import static org.mockito.Mockito.argThat;
 import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 
 import android.annotation.NonNull;
 import android.net.INetd;
@@ -46,6 +50,7 @@
 
 import androidx.test.filters.SmallTest;
 
+import com.android.internal.util.IndentingPrintWriter;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.bpf.ClatEgress4Key;
 import com.android.net.module.util.bpf.ClatEgress4Value;
@@ -53,6 +58,7 @@
 import com.android.net.module.util.bpf.ClatIngress6Value;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
+import com.android.testutils.TestBpfMap;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -64,6 +70,7 @@
 
 import java.io.FileDescriptor;
 import java.io.IOException;
+import java.io.StringWriter;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
 import java.util.Objects;
@@ -101,12 +108,12 @@
     private static final int RAW_SOCK_FD = 535;
     private static final int PACKET_SOCK_FD = 536;
     private static final long RAW_SOCK_COOKIE = 27149;
-    private static final ParcelFileDescriptor TUN_PFD = new ParcelFileDescriptor(
-            new FileDescriptor());
-    private static final ParcelFileDescriptor RAW_SOCK_PFD = new ParcelFileDescriptor(
-            new FileDescriptor());
-    private static final ParcelFileDescriptor PACKET_SOCK_PFD = new ParcelFileDescriptor(
-            new FileDescriptor());
+    private static final ParcelFileDescriptor TUN_PFD = spy(new ParcelFileDescriptor(
+            new FileDescriptor()));
+    private static final ParcelFileDescriptor RAW_SOCK_PFD = spy(new ParcelFileDescriptor(
+            new FileDescriptor()));
+    private static final ParcelFileDescriptor PACKET_SOCK_PFD = spy(new ParcelFileDescriptor(
+            new FileDescriptor()));
 
     private static final String EGRESS_PROG_PATH =
             "/sys/fs/bpf/net_shared/prog_clatd_schedcls_egress4_clat_rawip";
@@ -121,10 +128,13 @@
     private static final ClatIngress6Value INGRESS_VALUE = new ClatIngress6Value(STACKED_IFINDEX,
             INET4_LOCAL4);
 
+    private final TestBpfMap<ClatIngress6Key, ClatIngress6Value> mIngressMap =
+            spy(new TestBpfMap<>(ClatIngress6Key.class, ClatIngress6Value.class));
+    private final TestBpfMap<ClatEgress4Key, ClatEgress4Value> mEgressMap =
+            spy(new TestBpfMap<>(ClatEgress4Key.class, ClatEgress4Value.class));
+
     @Mock private INetd mNetd;
     @Spy private TestDependencies mDeps = new TestDependencies();
-    @Mock private IBpfMap<ClatIngress6Key, ClatIngress6Value> mIngressMap;
-    @Mock private IBpfMap<ClatEgress4Key, ClatEgress4Value> mEgressMap;
 
     /**
       * The dependency injection class is used to mock the JNI functions and system functions
@@ -505,4 +515,207 @@
         // Expected mtu is that CLAT_MAX_MTU(65536) minus MTU_DELTA(28).
         assertEquals(65508, ClatCoordinator.adjustMtu(CLAT_MAX_MTU + 1 /* over maximum mtu */));
     }
+
+    @Test
+    public void testDump() throws Exception {
+        final ClatCoordinator coordinator = makeClatCoordinator();
+        final StringWriter stringWriter = new StringWriter();
+        final IndentingPrintWriter ipw = new IndentingPrintWriter(stringWriter, " ");
+        coordinator.clatStart(BASE_IFACE, NETID, NAT64_IP_PREFIX);
+        coordinator.dump(ipw);
+
+        final String[] dumpStrings = stringWriter.toString().split("\n");
+        assertEquals(6, dumpStrings.length);
+        assertEquals("CLAT tracker: iface: test0 (1000), v4iface: v4-test0 (1001), "
+                + "v4: /192.0.0.46, v6: /2001:db8:0:b11::464, pfx96: /64:ff9b::, "
+                + "pid: 10483, cookie: 27149", dumpStrings[0].trim());
+        assertEquals("Forwarding rules:", dumpStrings[1].trim());
+        assertEquals("BPF ingress map: iif nat64Prefix v6Addr -> v4Addr oif",
+                dumpStrings[2].trim());
+        assertEquals("1000 /64:ff9b::/96 /2001:db8:0:b11::464 -> /192.0.0.46 1001",
+                dumpStrings[3].trim());
+        assertEquals("BPF egress map: iif v4Addr -> v6Addr nat64Prefix oif",
+                dumpStrings[4].trim());
+        assertEquals("1001 /192.0.0.46 -> /2001:db8:0:b11::464 /64:ff9b::/96 1000 ether",
+                dumpStrings[5].trim());
+    }
+
+    @Test
+    public void testNotStartClatWithInvalidPrefix() throws Exception {
+        final ClatCoordinator coordinator = makeClatCoordinator();
+        final IpPrefix invalidPrefix = new IpPrefix("2001:db8::/64");
+        assertThrows(IOException.class,
+                () -> coordinator.clatStart(BASE_IFACE, NETID, invalidPrefix));
+    }
+
+    private void assertStartClat(final TestDependencies deps) throws Exception {
+        final ClatCoordinator coordinator = new ClatCoordinator(deps);
+        assertNotNull(coordinator.clatStart(BASE_IFACE, NETID, NAT64_IP_PREFIX));
+    }
+
+    private void assertNotStartClat(final TestDependencies deps) {
+        // Expect that the injection function of TestDependencies causes clatStart() failed.
+        final ClatCoordinator coordinator = new ClatCoordinator(deps);
+        assertThrows(IOException.class,
+                () -> coordinator.clatStart(BASE_IFACE, NETID, NAT64_IP_PREFIX));
+    }
+
+    private void checkNotStartClat(final TestDependencies deps, final boolean needToCloseTunFd,
+            final boolean needToClosePacketSockFd, final boolean needToCloseRawSockFd)
+            throws Exception {
+        // [1] Expect that modified TestDependencies can't start clatd.
+        // Use precise check to make sure that there is no unexpected file descriptor closing.
+        clearInvocations(TUN_PFD, RAW_SOCK_PFD, PACKET_SOCK_PFD);
+        assertNotStartClat(deps);
+        if (needToCloseTunFd) {
+            verify(TUN_PFD).close();
+        } else {
+            verify(TUN_PFD, never()).close();
+        }
+        if (needToClosePacketSockFd) {
+            verify(PACKET_SOCK_PFD).close();
+        } else {
+            verify(PACKET_SOCK_PFD, never()).close();
+        }
+        if (needToCloseRawSockFd) {
+            verify(RAW_SOCK_PFD).close();
+        } else {
+            verify(RAW_SOCK_PFD, never()).close();
+        }
+
+        // [2] Expect that unmodified TestDependencies can start clatd.
+        // Used to make sure that the above modified TestDependencies has really broken the
+        // clatd starting.
+        assertStartClat(new TestDependencies());
+    }
+
+    // The following testNotStartClat* tests verifies bunches of code for unwinding the
+    // failure if any.
+    @Test
+    public void testNotStartClatWithNativeFailureSelectIpv4Address() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public String selectIpv4Address(@NonNull String v4addr, int prefixlen)
+                    throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), false /* needToCloseTunFd */,
+                false /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureGenerateIpv6Address() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public String generateIpv6Address(@NonNull String iface, @NonNull String v4,
+                    @NonNull String prefix64) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), false /* needToCloseTunFd */,
+                false /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureCreateTunInterface() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public int createTunInterface(@NonNull String tuniface) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), false /* needToCloseTunFd */,
+                false /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureDetectMtu() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public int detectMtu(@NonNull String platSubnet, int platSuffix, int mark)
+                    throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                false /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureOpenPacketSocket() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public int openPacketSocket() throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                false /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureOpenRawSocket6() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public int openRawSocket6(int mark) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                true /* needToClosePacketSockFd */, false /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureAddAnycastSetsockopt() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public void addAnycastSetsockopt(@NonNull FileDescriptor sock, String v6,
+                    int ifindex) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                true /* needToClosePacketSockFd */, true /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureTagSocketAsClat() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public long tagSocketAsClat(@NonNull FileDescriptor sock) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                true /* needToClosePacketSockFd */, true /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureConfigurePacketSocket() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public void configurePacketSocket(@NonNull FileDescriptor sock, String v6,
+                    int ifindex) throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                true /* needToClosePacketSockFd */, true /* needToCloseRawSockFd */);
+    }
+
+    @Test
+    public void testNotStartClatWithNativeFailureStartClatd() throws Exception {
+        class FailureDependencies extends TestDependencies {
+            @Override
+            public int startClatd(@NonNull FileDescriptor tunfd, @NonNull FileDescriptor readsock6,
+                    @NonNull FileDescriptor writesock6, @NonNull String iface,
+                    @NonNull String pfx96, @NonNull String v4, @NonNull String v6)
+                    throws IOException {
+                throw new IOException();
+            }
+        }
+        checkNotStartClat(new FailureDependencies(), true /* needToCloseTunFd */,
+                true /* needToClosePacketSockFd */, true /* needToCloseRawSockFd */);
+    }
 }
diff --git a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
index ecd17ba..354e79a 100644
--- a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
+++ b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
@@ -30,9 +30,6 @@
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_REQUIRED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 import static android.content.pm.PackageManager.MATCH_ANY_USER;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
-import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
-import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.net.ConnectivitySettingsManager.UIDS_ALLOWED_ON_RESTRICTED_NETWORKS;
 import static android.net.INetd.PERMISSION_INTERNET;
 import static android.net.INetd.PERMISSION_NETWORK;
@@ -698,7 +695,8 @@
         mNetdMonitor.expectNetworkPerm(PERMISSION_SYSTEM, new UserHandle[]{MOCK_USER1},
                 SYSTEM_APPID1);
 
-        final List<PackageInfo> pkgs = List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID21,
+        final List<PackageInfo> pkgs = List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID21,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, SYSTEM_APP_UID21, CHANGE_NETWORK_STATE));
         doReturn(pkgs).when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS),
@@ -764,9 +762,10 @@
                 MOCK_APPID1);
     }
 
-    private void doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates(@Nullable String ifName)
+    private void doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates(@Nullable String ifName)
             throws Exception {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12),
@@ -774,7 +773,7 @@
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         buildAndMockPackageInfoWithPermissions(MOCK_PACKAGE1, MOCK_UID11);
         mPermissionMonitor.startMonitoring();
-        // Every app on user 0 except MOCK_UID12 are under VPN.
+        // Every app on user 0 except MOCK_UID12 is subject to the VPN.
         final Set<UidRange> vpnRange1 = Set.of(
                 new UidRange(0, MOCK_UID12 - 1),
                 new UidRange(MOCK_UID12 + 1, UserHandle.PER_USER_RANGE - 1));
@@ -811,18 +810,19 @@
 
     @Test
     public void testUidFilteringDuringVpnConnectDisconnectAndUidUpdates() throws Exception {
-        doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates("tun0");
+        doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates("tun0");
     }
 
     @Test
     public void testUidFilteringDuringVpnConnectDisconnectAndUidUpdatesWithWildcard()
             throws Exception {
-        doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates(null /* ifName */);
+        doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates(null /* ifName */);
     }
 
     private void doTestUidFilteringDuringPackageInstallAndUninstall(@Nullable String ifName) throws
             Exception {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         NETWORK_STACK, CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
@@ -857,155 +857,149 @@
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisable() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // Every app on user 0 except MOCK_UID12 are under VPN.
-        final UidRange[] vpnRange1 = {
+        // Every app on user 0 except MOCK_UID12 is subject to the VPN.
+        final UidRange[] lockdownRange = {
                 new UidRange(0, MOCK_UID12 - 1),
                 new UidRange(MOCK_UID12 + 1, UserHandle.PER_USER_RANGE - 1)
         };
 
-        // Add Lockdown uid range, expect a rule to be set up for user app MOCK_UID11
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange1);
-        verify(mBpfNetMaps)
-                .setUidRule(
-                        eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange1));
+        // Add Lockdown uid range, expect a rule to be set up for MOCK_UID11 and VPN_UID
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range, expect rules to be torn down
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange1);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisableWithMultiAdd() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // MOCK_UID11 is under VPN.
+        // MOCK_UID11 is subject to the VPN.
         final UidRange range = new UidRange(MOCK_UID11, MOCK_UID11);
-        final UidRange[] vpnRange = {range};
+        final UidRange[] lockdownRange = {range};
 
         // Add Lockdown uid range at 1st time, expect a rule to be set up
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Add Lockdown uid range at 2nd time, expect a rule not to be set up because the uid
         // already has the rule
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(),  anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 1st time, expect a rule not to be torn down because we added
         // the range 2 times.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(),  anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 2nd time, expect a rule to be torn down because we added
         // twice and we removed twice.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisableWithDuplicates() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // MOCK_UID11 is under VPN.
+        // MOCK_UID11 is subject to the VPN.
         final UidRange range = new UidRange(MOCK_UID11, MOCK_UID11);
-        final UidRange[] vpnRangeDuplicates = {range, range};
-        final UidRange[] vpnRange = {range};
+        final UidRange[] lockdownRangeDuplicates = {range, range};
+        final UidRange[] lockdownRange = {range};
 
         // Add Lockdown uid ranges which contains duplicated uid ranges
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRangeDuplicates);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRangeDuplicates);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 1st time, expect a rule not to be torn down because uid
         // ranges we added contains duplicated uid ranges.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(), anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 2nd time, expect a rule to be torn down.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithInstallAndUnInstall() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         NETWORK_STACK, CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         doReturn(List.of(MOCK_USER1, MOCK_USER2)).when(mUserManager).getUserHandles(eq(true));
 
         mPermissionMonitor.startMonitoring();
-        final UidRange[] vpnRange = {
+        final UidRange[] lockdownRange = {
                 UidRange.createForUser(MOCK_USER1),
                 UidRange.createForUser(MOCK_USER2)
         };
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+
+        reset(mBpfNetMaps);
 
         // Installing package should add Lockdown rules
         addPackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2}, MOCK_PACKAGE1, MOCK_APPID1);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID21),
-                        eq(FIREWALL_RULE_DENY));
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID21, true /* add */);
 
         reset(mBpfNetMaps);
 
         // Uninstalling package should remove Lockdown rules
         mPermissionMonitor.onPackageRemoved(MOCK_PACKAGE1, MOCK_UID11);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
-        verify(mBpfNetMaps, never())
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID21),
-                        eq(FIREWALL_RULE_ALLOW));
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
     }
 
     // Normal package add/remove operations will trigger multiple intent for uids corresponding to
@@ -1329,7 +1323,8 @@
     public void testOnExternalApplicationsAvailable() throws Exception {
         // Initial the permission state. MOCK_PACKAGE1 and MOCK_PACKAGE2 are installed on external
         // and have different uids. There has no permission for both uids.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
@@ -1387,7 +1382,8 @@
             throws Exception {
         // Initial the permission state. MOCK_PACKAGE1 and MOCK_PACKAGE2 are installed on external
         // storage and shared on MOCK_UID11. There has no permission for MOCK_UID11.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID11)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
@@ -1413,7 +1409,8 @@
         // Initial the permission state. MOCK_PACKAGE1 is installed on external storage and
         // MOCK_PACKAGE2 is installed on device. These two packages are shared on MOCK_UID11.
         // MOCK_UID11 has NETWORK and INTERNET permissions.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID11, CHANGE_NETWORK_STATE, INTERNET)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
diff --git a/tests/unit/java/com/android/server/connectivity/VpnTest.java b/tests/unit/java/com/android/server/connectivity/VpnTest.java
index eb35469..5c1992d 100644
--- a/tests/unit/java/com/android/server/connectivity/VpnTest.java
+++ b/tests/unit/java/com/android/server/connectivity/VpnTest.java
@@ -20,18 +20,17 @@
 import static android.Manifest.permission.CONTROL_VPN;
 import static android.content.pm.PackageManager.PERMISSION_DENIED;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
-import static android.content.pm.UserInfo.FLAG_ADMIN;
-import static android.content.pm.UserInfo.FLAG_MANAGED_PROFILE;
-import static android.content.pm.UserInfo.FLAG_PRIMARY;
-import static android.content.pm.UserInfo.FLAG_RESTRICTED;
 import static android.net.ConnectivityManager.NetworkCallback;
 import static android.net.INetd.IF_STATE_DOWN;
 import static android.net.INetd.IF_STATE_UP;
+import static android.net.RouteInfo.RTN_UNREACHABLE;
 import static android.net.VpnManager.TYPE_VPN_PLATFORM;
+import static android.net.ipsec.ike.IkeSessionConfiguration.EXTENSION_TYPE_MOBIKE;
 import static android.os.Build.VERSION_CODES.S_V2;
 import static android.os.UserHandle.PER_USER_RANGE;
 
 import static com.android.modules.utils.build.SdkLevel.isAtLeastT;
+import static com.android.testutils.Cleanup.testAndCleanup;
 import static com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import static com.android.testutils.MiscAsserts.assertThrows;
 
@@ -39,6 +38,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
@@ -59,6 +59,7 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.timeout;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -83,24 +84,29 @@
 import android.net.InetAddresses;
 import android.net.InterfaceConfigurationParcel;
 import android.net.IpPrefix;
+import android.net.IpSecConfig;
 import android.net.IpSecManager;
+import android.net.IpSecTransform;
 import android.net.IpSecTunnelInterfaceResponse;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.LocalSocket;
 import android.net.Network;
 import android.net.NetworkAgent;
-import android.net.NetworkAgentConfig;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo.DetailedState;
-import android.net.NetworkProvider;
 import android.net.RouteInfo;
 import android.net.UidRangeParcel;
 import android.net.VpnManager;
 import android.net.VpnProfileState;
 import android.net.VpnService;
 import android.net.VpnTransportInfo;
+import android.net.ipsec.ike.ChildSessionCallback;
+import android.net.ipsec.ike.ChildSessionConfiguration;
 import android.net.ipsec.ike.IkeSessionCallback;
+import android.net.ipsec.ike.IkeSessionConfiguration;
+import android.net.ipsec.ike.IkeSessionConnectionInfo;
+import android.net.ipsec.ike.IkeTrafficSelector;
 import android.net.ipsec.ike.exceptions.IkeException;
 import android.net.ipsec.ike.exceptions.IkeNetworkLostException;
 import android.net.ipsec.ike.exceptions.IkeNonProtocolException;
@@ -110,7 +116,6 @@
 import android.os.Bundle;
 import android.os.ConditionVariable;
 import android.os.INetworkManagementService;
-import android.os.Looper;
 import android.os.ParcelFileDescriptor;
 import android.os.PowerWhitelistManager;
 import android.os.Process;
@@ -121,6 +126,7 @@
 import android.security.Credentials;
 import android.util.ArrayMap;
 import android.util.ArraySet;
+import android.util.Pair;
 import android.util.Range;
 
 import androidx.test.filters.SmallTest;
@@ -133,6 +139,7 @@
 import com.android.modules.utils.build.SdkLevel;
 import com.android.server.DeviceIdleInternal;
 import com.android.server.IpSecService;
+import com.android.server.VpnTestBase;
 import com.android.server.vcn.util.PersistableBundleUtils;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
@@ -155,6 +162,7 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
@@ -164,7 +172,11 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 
@@ -176,55 +188,53 @@
  */
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@IgnoreUpTo(VERSION_CODES.S_V2)
-public class VpnTest {
+@IgnoreUpTo(S_V2)
+public class VpnTest extends VpnTestBase {
     private static final String TAG = "VpnTest";
 
     @Rule
     public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
 
-    // Mock users
-    static final UserInfo primaryUser = new UserInfo(27, "Primary", FLAG_ADMIN | FLAG_PRIMARY);
-    static final UserInfo secondaryUser = new UserInfo(15, "Secondary", FLAG_ADMIN);
-    static final UserInfo restrictedProfileA = new UserInfo(40, "RestrictedA", FLAG_RESTRICTED);
-    static final UserInfo restrictedProfileB = new UserInfo(42, "RestrictedB", FLAG_RESTRICTED);
-    static final UserInfo managedProfileA = new UserInfo(45, "ManagedA", FLAG_MANAGED_PROFILE);
-    static {
-        restrictedProfileA.restrictedProfileParentId = primaryUser.id;
-        restrictedProfileB.restrictedProfileParentId = secondaryUser.id;
-        managedProfileA.profileGroupId = primaryUser.id;
-    }
-
     static final Network EGRESS_NETWORK = new Network(101);
     static final String EGRESS_IFACE = "wlan0";
-    static final String TEST_VPN_PKG = "com.testvpn.vpn";
+    private static final String TEST_VPN_CLIENT = "2.4.6.8";
     private static final String TEST_VPN_SERVER = "1.2.3.4";
     private static final String TEST_VPN_IDENTITY = "identity";
     private static final byte[] TEST_VPN_PSK = "psk".getBytes();
 
+    private static final int IP4_PREFIX_LEN = 32;
+    private static final int MIN_PORT = 0;
+    private static final int MAX_PORT = 65535;
+
+    private static final InetAddress TEST_VPN_CLIENT_IP =
+            InetAddresses.parseNumericAddress(TEST_VPN_CLIENT);
+    private static final InetAddress TEST_VPN_SERVER_IP =
+            InetAddresses.parseNumericAddress(TEST_VPN_SERVER);
+    private static final InetAddress TEST_VPN_CLIENT_IP_2 =
+            InetAddresses.parseNumericAddress("192.0.2.200");
+    private static final InetAddress TEST_VPN_SERVER_IP_2 =
+            InetAddresses.parseNumericAddress("192.0.2.201");
+    private static final InetAddress TEST_VPN_INTERNAL_IP =
+            InetAddresses.parseNumericAddress("198.51.100.10");
+    private static final InetAddress TEST_VPN_INTERNAL_DNS =
+            InetAddresses.parseNumericAddress("8.8.8.8");
+
+    private static final IkeTrafficSelector IN_TS =
+            new IkeTrafficSelector(MIN_PORT, MAX_PORT, TEST_VPN_INTERNAL_IP, TEST_VPN_INTERNAL_IP);
+    private static final IkeTrafficSelector OUT_TS =
+            new IkeTrafficSelector(MIN_PORT, MAX_PORT,
+                    InetAddresses.parseNumericAddress("0.0.0.0"),
+                    InetAddresses.parseNumericAddress("255.255.255.255"));
+
     private static final Network TEST_NETWORK = new Network(Integer.MAX_VALUE);
+    private static final Network TEST_NETWORK_2 = new Network(Integer.MAX_VALUE - 1);
     private static final String TEST_IFACE_NAME = "TEST_IFACE";
     private static final int TEST_TUNNEL_RESOURCE_ID = 0x2345;
     private static final long TEST_TIMEOUT_MS = 500L;
     private static final String PRIMARY_USER_APP_EXCLUDE_KEY =
-            "VPN_APP_EXCLUDED_27_com.testvpn.vpn";
-    /**
-     * Names and UIDs for some fake packages. Important points:
-     *  - UID is ordered increasing.
-     *  - One pair of packages have consecutive UIDs.
-     */
-    static final String[] PKGS = {"com.example", "org.example", "net.example", "web.vpn"};
+            "VPNAPPEXCLUDED_27_com.testvpn.vpn";
     static final String PKGS_BYTES = getPackageByteString(List.of(PKGS));
-    static final int[] PKG_UIDS = {10066, 10077, 10078, 10400};
-
-    // Mock packages
-    static final Map<String, Integer> mPackages = new ArrayMap<>();
-    static {
-        for (int i = 0; i < PKGS.length; i++) {
-            mPackages.put(PKGS[i], PKG_UIDS[i]);
-        }
-    }
-    private static final Range<Integer> PRI_USER_RANGE = uidRangeForUser(primaryUser.id);
+    private static final Range<Integer> PRIMARY_USER_RANGE = uidRangeForUser(PRIMARY_USER.id);
 
     @Mock(answer = Answers.RETURNS_DEEP_STUBS) private Context mContext;
     @Mock private UserManager mUserManager;
@@ -234,15 +244,21 @@
     @Mock private AppOpsManager mAppOps;
     @Mock private NotificationManager mNotificationManager;
     @Mock private Vpn.SystemServices mSystemServices;
+    @Mock private Vpn.IkeSessionWrapper mIkeSessionWrapper;
     @Mock private Vpn.Ikev2SessionCreator mIkev2SessionCreator;
+    @Mock private NetworkAgent mMockNetworkAgent;
     @Mock private ConnectivityManager mConnectivityManager;
     @Mock private IpSecService mIpSecService;
     @Mock private VpnProfileStore mVpnProfileStore;
+    @Mock private ScheduledThreadPoolExecutor mExecutor;
+    @Mock private ScheduledFuture mScheduledFuture;
     @Mock DeviceIdleInternal mDeviceIdleInternal;
     private final VpnProfile mVpnProfile;
 
     private IpSecManager mIpSecManager;
 
+    private TestDeps mTestDeps;
+
     public VpnTest() throws Exception {
         // Build an actual VPN profile that is capable of being converted to and from an
         // Ikev2VpnProfile
@@ -257,9 +273,10 @@
         MockitoAnnotations.initMocks(this);
 
         mIpSecManager = new IpSecManager(mContext, mIpSecService);
+        mTestDeps = spy(new TestDeps());
 
         when(mContext.getPackageManager()).thenReturn(mPackageManager);
-        setMockedPackages(mPackages);
+        setMockedPackages(sPackages);
 
         when(mContext.getPackageName()).thenReturn(TEST_VPN_PKG);
         when(mContext.getOpPackageName()).thenReturn(TEST_VPN_PKG);
@@ -297,6 +314,28 @@
         // itself, so set the default value of Context#checkCallingOrSelfPermission to
         // PERMISSION_DENIED.
         doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(any());
+
+        // Set up mIkev2SessionCreator and mExecutor
+        resetIkev2SessionCreator(mIkeSessionWrapper);
+        resetExecutor(mScheduledFuture);
+    }
+
+    private void resetIkev2SessionCreator(Vpn.IkeSessionWrapper ikeSession) {
+        reset(mIkev2SessionCreator);
+        when(mIkev2SessionCreator.createIkeSession(any(), any(), any(), any(), any(), any()))
+                .thenReturn(ikeSession);
+    }
+
+    private void resetExecutor(ScheduledFuture scheduledFuture) {
+        doAnswer(
+                (invocation) -> {
+                    ((Runnable) invocation.getArgument(0)).run();
+                    return null;
+                })
+            .when(mExecutor)
+            .execute(any());
+        when(mExecutor.schedule(
+                any(Runnable.class), anyLong(), any())).thenReturn(mScheduledFuture);
     }
 
     @After
@@ -342,50 +381,51 @@
 
     @Test
     public void testRestrictedProfilesAreAddedToVpn() {
-        setMockedUsers(primaryUser, secondaryUser, restrictedProfileA, restrictedProfileB);
+        setMockedUsers(PRIMARY_USER, SECONDARY_USER, RESTRICTED_PROFILE_A, RESTRICTED_PROFILE_B);
 
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
 
         // Assume the user can have restricted profiles.
         doReturn(true).when(mUserManager).canHaveRestrictedProfile();
         final Set<Range<Integer>> ranges =
-                vpn.createUserAndRestrictedProfilesRanges(primaryUser.id, null, null);
+                vpn.createUserAndRestrictedProfilesRanges(PRIMARY_USER.id, null, null);
 
-        assertEquals(rangeSet(PRI_USER_RANGE, uidRangeForUser(restrictedProfileA.id)), ranges);
+        assertEquals(rangeSet(PRIMARY_USER_RANGE, uidRangeForUser(RESTRICTED_PROFILE_A.id)),
+                 ranges);
     }
 
     @Test
     public void testManagedProfilesAreNotAddedToVpn() {
-        setMockedUsers(primaryUser, managedProfileA);
+        setMockedUsers(PRIMARY_USER, MANAGED_PROFILE_A);
 
-        final Vpn vpn = createVpn(primaryUser.id);
-        final Set<Range<Integer>> ranges = vpn.createUserAndRestrictedProfilesRanges(primaryUser.id,
-                null, null);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        final Set<Range<Integer>> ranges = vpn.createUserAndRestrictedProfilesRanges(
+                PRIMARY_USER.id, null, null);
 
-        assertEquals(rangeSet(PRI_USER_RANGE), ranges);
+        assertEquals(rangeSet(PRIMARY_USER_RANGE), ranges);
     }
 
     @Test
     public void testAddUserToVpnOnlyAddsOneUser() {
-        setMockedUsers(primaryUser, restrictedProfileA, managedProfileA);
+        setMockedUsers(PRIMARY_USER, RESTRICTED_PROFILE_A, MANAGED_PROFILE_A);
 
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
         final Set<Range<Integer>> ranges = new ArraySet<>();
-        vpn.addUserToRanges(ranges, primaryUser.id, null, null);
+        vpn.addUserToRanges(ranges, PRIMARY_USER.id, null, null);
 
-        assertEquals(rangeSet(PRI_USER_RANGE), ranges);
+        assertEquals(rangeSet(PRIMARY_USER_RANGE), ranges);
     }
 
     @Test
     public void testUidAllowAndDenylist() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
-        final Range<Integer> user = PRI_USER_RANGE;
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        final Range<Integer> user = PRIMARY_USER_RANGE;
         final int userStart = user.getLower();
         final int userStop = user.getUpper();
         final String[] packages = {PKGS[0], PKGS[1], PKGS[2]};
 
         // Allowed list
-        final Set<Range<Integer>> allow = vpn.createUserAndRestrictedProfilesRanges(primaryUser.id,
+        final Set<Range<Integer>> allow = vpn.createUserAndRestrictedProfilesRanges(PRIMARY_USER.id,
                 Arrays.asList(packages), null /* disallowedApplications */);
         assertEquals(rangeSet(
                 uidRange(userStart + PKG_UIDS[0], userStart + PKG_UIDS[0]),
@@ -398,7 +438,7 @@
 
         // Denied list
         final Set<Range<Integer>> disallow =
-                vpn.createUserAndRestrictedProfilesRanges(primaryUser.id,
+                vpn.createUserAndRestrictedProfilesRanges(PRIMARY_USER.id,
                         null /* allowedApplications */, Arrays.asList(packages));
         assertEquals(rangeSet(
                 uidRange(userStart, userStart + PKG_UIDS[0] - 1),
@@ -420,7 +460,7 @@
 
     @Test
     public void testGetAlwaysAndOnGetLockDown() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
 
         // Default state.
         assertFalse(vpn.getAlwaysOn());
@@ -444,8 +484,8 @@
 
     @Test
     public void testLockdownChangingPackage() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
-        final Range<Integer> user = PRI_USER_RANGE;
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        final Range<Integer> user = PRIMARY_USER_RANGE;
         final int userStart = user.getLower();
         final int userStop = user.getUpper();
         // Set always-on without lockdown.
@@ -478,8 +518,8 @@
 
     @Test
     public void testLockdownAllowlist() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
-        final Range<Integer> user = PRI_USER_RANGE;
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        final Range<Integer> user = PRIMARY_USER_RANGE;
         final int userStart = user.getLower();
         final int userStop = user.getUpper();
         // Set always-on with lockdown and allow app PKGS[2] from lockdown.
@@ -589,9 +629,9 @@
 
     @Test
     public void testLockdownRuleRepeatability() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
         final UidRangeParcel[] primaryUserRangeParcel = new UidRangeParcel[] {
-                new UidRangeParcel(PRI_USER_RANGE.getLower(), PRI_USER_RANGE.getUpper())};
+                new UidRangeParcel(PRIMARY_USER_RANGE.getLower(), PRIMARY_USER_RANGE.getUpper())};
         // Given legacy lockdown is already enabled,
         vpn.setLockdown(true);
         verify(mConnectivityManager, times(1)).setRequireVpnForUids(true,
@@ -622,9 +662,9 @@
     @Test
     public void testLockdownRuleReversibility() throws Exception {
         doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(CONTROL_VPN);
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
         final UidRangeParcel[] entireUser = {
-            new UidRangeParcel(PRI_USER_RANGE.getLower(), PRI_USER_RANGE.getUpper())
+            new UidRangeParcel(PRIMARY_USER_RANGE.getLower(), PRIMARY_USER_RANGE.getUpper())
         };
         final UidRangeParcel[] exceptPkg0 = {
             new UidRangeParcel(entireUser[0].start, entireUser[0].start + PKG_UIDS[0] - 1),
@@ -674,17 +714,17 @@
 
     @Test
     public void testIsAlwaysOnPackageSupported() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
 
         ApplicationInfo appInfo = new ApplicationInfo();
-        when(mPackageManager.getApplicationInfoAsUser(eq(PKGS[0]), anyInt(), eq(primaryUser.id)))
+        when(mPackageManager.getApplicationInfoAsUser(eq(PKGS[0]), anyInt(), eq(PRIMARY_USER.id)))
                 .thenReturn(appInfo);
 
         ServiceInfo svcInfo = new ServiceInfo();
         ResolveInfo resInfo = new ResolveInfo();
         resInfo.serviceInfo = svcInfo;
         when(mPackageManager.queryIntentServicesAsUser(any(), eq(PackageManager.GET_META_DATA),
-                eq(primaryUser.id)))
+                eq(PRIMARY_USER.id)))
                 .thenReturn(Collections.singletonList(resInfo));
 
         // null package name should return false
@@ -708,9 +748,9 @@
 
     @Test
     public void testNotificationShownForAlwaysOnApp() throws Exception {
-        final UserHandle userHandle = UserHandle.of(primaryUser.id);
-        final Vpn vpn = createVpn(primaryUser.id);
-        setMockedUsers(primaryUser);
+        final UserHandle userHandle = UserHandle.of(PRIMARY_USER.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        setMockedUsers(PRIMARY_USER);
 
         final InOrder order = inOrder(mNotificationManager);
 
@@ -743,15 +783,15 @@
      */
     @Test
     public void testGetProfileNameForPackage() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
-        setMockedUsers(primaryUser);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        setMockedUsers(PRIMARY_USER);
 
-        final String expected = Credentials.PLATFORM_VPN + primaryUser.id + "_" + TEST_VPN_PKG;
+        final String expected = Credentials.PLATFORM_VPN + PRIMARY_USER.id + "_" + TEST_VPN_PKG;
         assertEquals(expected, vpn.getProfileNameForPackage(TEST_VPN_PKG));
     }
 
     private Vpn createVpnAndSetupUidChecks(String... grantedOps) throws Exception {
-        return createVpnAndSetupUidChecks(primaryUser, grantedOps);
+        return createVpnAndSetupUidChecks(PRIMARY_USER, grantedOps);
     }
 
     private Vpn createVpnAndSetupUidChecks(UserInfo user, String... grantedOps) throws Exception {
@@ -808,14 +848,11 @@
 
         vpn.startVpnProfile(TEST_VPN_PKG);
         verify(mVpnProfileStore).get(eq(vpn.getProfileNameForPackage(TEST_VPN_PKG)));
-        vpn.mNetworkAgent = new NetworkAgent(mContext, Looper.getMainLooper(), TAG,
-                new NetworkCapabilities.Builder().build(), new LinkProperties(), 10 /* score */,
-                new NetworkAgentConfig.Builder().build(),
-                new NetworkProvider(mContext, Looper.getMainLooper(), TAG)) {};
+        vpn.mNetworkAgent = mMockNetworkAgent;
         return vpn;
     }
 
-    @Test @IgnoreUpTo(S_V2)
+    @Test
     public void testSetAndGetAppExclusionList() throws Exception {
         final Vpn vpn = prepareVpnForVerifyAppExclusionList();
         verify(mVpnProfileStore, never()).put(eq(PRIMARY_USER_APP_EXCLUDE_KEY), any());
@@ -824,16 +861,90 @@
                 .put(eq(PRIMARY_USER_APP_EXCLUDE_KEY),
                      eq(HexDump.hexStringToByteArray(PKGS_BYTES)));
         assertEquals(vpn.createUserAndRestrictedProfilesRanges(
-                primaryUser.id, null, Arrays.asList(PKGS)),
+                PRIMARY_USER.id, null, Arrays.asList(PKGS)),
                 vpn.mNetworkCapabilities.getUids());
         assertEquals(Arrays.asList(PKGS), vpn.getAppExclusionList(TEST_VPN_PKG));
     }
 
-    @Test @IgnoreUpTo(S_V2)
+    @Test
+    public void testRefreshPlatformVpnAppExclusionList_updatesExcludedUids() throws Exception {
+        final Vpn vpn = prepareVpnForVerifyAppExclusionList();
+        vpn.setAppExclusionList(TEST_VPN_PKG, Arrays.asList(PKGS));
+        verify(mMockNetworkAgent).sendNetworkCapabilities(any());
+        assertEquals(Arrays.asList(PKGS), vpn.getAppExclusionList(TEST_VPN_PKG));
+
+        reset(mMockNetworkAgent);
+
+        // Remove one of the package
+        List<Integer> newExcludedUids = toList(PKG_UIDS);
+        newExcludedUids.remove((Integer) PKG_UIDS[0]);
+        sPackages.remove(PKGS[0]);
+        vpn.refreshPlatformVpnAppExclusionList();
+
+        // List in keystore is not changed, but UID for the removed packages is no longer exempted.
+        assertEquals(Arrays.asList(PKGS), vpn.getAppExclusionList(TEST_VPN_PKG));
+        assertEquals(makeVpnUidRange(PRIMARY_USER.id, newExcludedUids),
+                vpn.mNetworkCapabilities.getUids());
+        ArgumentCaptor<NetworkCapabilities> ncCaptor =
+                ArgumentCaptor.forClass(NetworkCapabilities.class);
+        verify(mMockNetworkAgent).sendNetworkCapabilities(ncCaptor.capture());
+        assertEquals(makeVpnUidRange(PRIMARY_USER.id, newExcludedUids),
+                ncCaptor.getValue().getUids());
+
+        reset(mMockNetworkAgent);
+
+        // Add the package back
+        newExcludedUids.add(PKG_UIDS[0]);
+        sPackages.put(PKGS[0], PKG_UIDS[0]);
+        vpn.refreshPlatformVpnAppExclusionList();
+
+        // List in keystore is not changed and the uid list should be updated in the net cap.
+        assertEquals(Arrays.asList(PKGS), vpn.getAppExclusionList(TEST_VPN_PKG));
+        assertEquals(makeVpnUidRange(PRIMARY_USER.id, newExcludedUids),
+                vpn.mNetworkCapabilities.getUids());
+        verify(mMockNetworkAgent).sendNetworkCapabilities(ncCaptor.capture());
+        assertEquals(makeVpnUidRange(PRIMARY_USER.id, newExcludedUids),
+                ncCaptor.getValue().getUids());
+    }
+
+    private Set<Range<Integer>> makeVpnUidRange(int userId, List<Integer> excludedList) {
+        final SortedSet<Integer> list = new TreeSet<>();
+
+        final int userBase = userId * UserHandle.PER_USER_RANGE;
+        for (int uid : excludedList) {
+            final int applicationUid = UserHandle.getUid(userId, uid);
+            list.add(applicationUid);
+            list.add(Process.toSdkSandboxUid(applicationUid)); // Add Sdk Sandbox UID
+        }
+
+        final int minUid = userBase;
+        final int maxUid = userBase + UserHandle.PER_USER_RANGE - 1;
+        final Set<Range<Integer>> ranges = new ArraySet<>();
+
+        // Iterate the list to create the ranges between each uid.
+        int start = minUid;
+        for (int uid : list) {
+            if (uid == start) {
+                start++;
+            } else {
+                ranges.add(new Range<>(start, uid - 1));
+                start = uid + 1;
+            }
+        }
+
+        // Create the range between last uid and max uid.
+        if (start <= maxUid) {
+            ranges.add(new Range<>(start, maxUid));
+        }
+
+        return ranges;
+    }
+
+    @Test
     public void testSetAndGetAppExclusionListRestrictedUser() throws Exception {
         final Vpn vpn = prepareVpnForVerifyAppExclusionList();
         // Mock it to restricted profile
-        when(mUserManager.getUserInfo(anyInt())).thenReturn(restrictedProfileA);
+        when(mUserManager.getUserInfo(anyInt())).thenReturn(RESTRICTED_PROFILE_A);
         // Restricted users cannot configure VPNs
         assertThrows(SecurityException.class,
                 () -> vpn.setAppExclusionList(TEST_VPN_PKG, new ArrayList<>()));
@@ -883,7 +994,7 @@
     public void testProvisionVpnProfileRestrictedUser() throws Exception {
         final Vpn vpn =
                 createVpnAndSetupUidChecks(
-                        restrictedProfileA, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+                        RESTRICTED_PROFILE_A, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
 
         try {
             vpn.provisionVpnProfile(TEST_VPN_PKG, mVpnProfile);
@@ -906,7 +1017,7 @@
     public void testDeleteVpnProfileRestrictedUser() throws Exception {
         final Vpn vpn =
                 createVpnAndSetupUidChecks(
-                        restrictedProfileA, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+                        RESTRICTED_PROFILE_A, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
 
         try {
             vpn.deleteVpnProfile(TEST_VPN_PKG);
@@ -1029,7 +1140,7 @@
     public void testStartVpnProfileRestrictedUser() throws Exception {
         final Vpn vpn =
                 createVpnAndSetupUidChecks(
-                        restrictedProfileA, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+                        RESTRICTED_PROFILE_A, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
 
         try {
             vpn.startVpnProfile(TEST_VPN_PKG);
@@ -1042,7 +1153,7 @@
     public void testStopVpnProfileRestrictedUser() throws Exception {
         final Vpn vpn =
                 createVpnAndSetupUidChecks(
-                        restrictedProfileA, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+                        RESTRICTED_PROFILE_A, AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
 
         try {
             vpn.stopVpnProfile(TEST_VPN_PKG);
@@ -1113,7 +1224,7 @@
     private void verifyVpnManagerEvent(String sessionKey, String category, int errorClass,
             int errorCode, VpnProfileState... profileState) {
         final Context userContext =
-                mContext.createContextAsUser(UserHandle.of(primaryUser.id), 0 /* flags */);
+                mContext.createContextAsUser(UserHandle.of(PRIMARY_USER.id), 0 /* flags */);
         final ArgumentCaptor<Intent> intentArgumentCaptor = ArgumentCaptor.forClass(Intent.class);
 
         final int verifyTimes = (profileState == null) ? 1 : profileState.length;
@@ -1180,7 +1291,7 @@
         assumeTrue(SdkLevel.isAtLeastT());
         // Calling setAlwaysOnPackage() needs to hold CONTROL_VPN.
         doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(CONTROL_VPN);
-        final Vpn vpn = createVpn(primaryUser.id);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
         // Enable VPN always-on for PKGS[1].
         assertTrue(vpn.setAlwaysOnPackage(PKGS[1], false /* lockdown */,
                 null /* lockdownAllowlist */));
@@ -1249,6 +1360,31 @@
     }
 
     @Test
+    public void testReconnectVpnManagerVpnWithAlwaysOnEnabled() throws Exception {
+        final Vpn vpn = createVpnAndSetupUidChecks(AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+        when(mVpnProfileStore.get(vpn.getProfileNameForPackage(TEST_VPN_PKG)))
+                .thenReturn(mVpnProfile.encode());
+        vpn.startVpnProfile(TEST_VPN_PKG);
+        verifyPlatformVpnIsActivated(TEST_VPN_PKG);
+
+        // Enable VPN always-on for TEST_VPN_PKG.
+        assertTrue(vpn.setAlwaysOnPackage(TEST_VPN_PKG, false /* lockdown */,
+                null /* lockdownAllowlist */));
+
+        // Reset to verify next startVpnProfile.
+        reset(mAppOps);
+
+        vpn.stopVpnProfile(TEST_VPN_PKG);
+
+        // Reconnect the vpn with different package will cause exception.
+        assertThrows(SecurityException.class, () -> vpn.startVpnProfile(PKGS[0]));
+
+        // Reconnect the vpn again with the vpn always on package w/o exception.
+        vpn.startVpnProfile(TEST_VPN_PKG);
+        verifyPlatformVpnIsActivated(TEST_VPN_PKG);
+    }
+
+    @Test
     public void testSetPackageAuthorizationVpnService() throws Exception {
         final Vpn vpn = createVpnAndSetupUidChecks();
 
@@ -1315,7 +1451,7 @@
                 config -> Arrays.asList(config.flags).contains(flag)));
     }
 
-    private void setupPlatformVpnWithSpecificExceptionAndItsErrorCode(IkeException exception,
+    private void doTestPlatformVpnWithException(IkeException exception,
             String category, int errorType, int errorCode) throws Exception {
         final ArgumentCaptor<IkeSessionCallback> captor =
                 ArgumentCaptor.forClass(IkeSessionCallback.class);
@@ -1333,6 +1469,7 @@
         // state
         verify(mIkev2SessionCreator, timeout(TEST_TIMEOUT_MS))
                 .createIkeSession(any(), any(), any(), any(), captor.capture(), any());
+        reset(mIkev2SessionCreator);
         final IkeSessionCallback ikeCb = captor.getValue();
         ikeCb.onClosedWithException(exception);
 
@@ -1342,15 +1479,45 @@
         if (errorType == VpnManager.ERROR_CLASS_NOT_RECOVERABLE) {
             verify(mConnectivityManager, timeout(TEST_TIMEOUT_MS))
                     .unregisterNetworkCallback(eq(cb));
+        } else if (errorType == VpnManager.ERROR_CLASS_RECOVERABLE) {
+            int retryIndex = 0;
+            final IkeSessionCallback ikeCb2 = verifyRetryAndGetNewIkeCb(retryIndex++);
+
+            ikeCb2.onClosedWithException(exception);
+            verifyRetryAndGetNewIkeCb(retryIndex++);
         }
     }
 
+    private IkeSessionCallback verifyRetryAndGetNewIkeCb(int retryIndex) {
+        final ArgumentCaptor<Runnable> runnableCaptor =
+                ArgumentCaptor.forClass(Runnable.class);
+        final ArgumentCaptor<IkeSessionCallback> ikeCbCaptor =
+                ArgumentCaptor.forClass(IkeSessionCallback.class);
+
+        // Verify retry is scheduled
+        final long expectedDelay = mTestDeps.getNextRetryDelaySeconds(retryIndex);
+        verify(mExecutor).schedule(runnableCaptor.capture(), eq(expectedDelay), any());
+
+        // Mock the event of firing the retry task
+        runnableCaptor.getValue().run();
+
+        verify(mIkev2SessionCreator)
+                .createIkeSession(any(), any(), any(), any(), ikeCbCaptor.capture(), any());
+
+        // Forget the mIkev2SessionCreator#createIkeSession call and mExecutor#schedule call
+        // for the next retry verification
+        resetIkev2SessionCreator(mIkeSessionWrapper);
+        resetExecutor(mScheduledFuture);
+
+        return ikeCbCaptor.getValue();
+    }
+
     @Test
     public void testStartPlatformVpnAuthenticationFailed() throws Exception {
         final IkeProtocolException exception = mock(IkeProtocolException.class);
         final int errorCode = IkeProtocolException.ERROR_TYPE_AUTHENTICATION_FAILED;
         when(exception.getErrorType()).thenReturn(errorCode);
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_IKE_ERROR, VpnManager.ERROR_CLASS_NOT_RECOVERABLE,
                 errorCode);
     }
@@ -1360,7 +1527,7 @@
         final IkeProtocolException exception = mock(IkeProtocolException.class);
         final int errorCode = IkeProtocolException.ERROR_TYPE_TEMPORARY_FAILURE;
         when(exception.getErrorType()).thenReturn(errorCode);
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_IKE_ERROR, VpnManager.ERROR_CLASS_RECOVERABLE, errorCode);
     }
 
@@ -1370,7 +1537,7 @@
         final UnknownHostException unknownHostException = new UnknownHostException();
         final int errorCode = VpnManager.ERROR_CODE_NETWORK_UNKNOWN_HOST;
         when(exception.getCause()).thenReturn(unknownHostException);
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_NETWORK_ERROR, VpnManager.ERROR_CLASS_RECOVERABLE,
                 errorCode);
     }
@@ -1382,7 +1549,7 @@
                 new IkeTimeoutException("IkeTimeoutException");
         final int errorCode = VpnManager.ERROR_CODE_NETWORK_PROTOCOL_TIMEOUT;
         when(exception.getCause()).thenReturn(ikeTimeoutException);
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_NETWORK_ERROR, VpnManager.ERROR_CLASS_RECOVERABLE,
                 errorCode);
     }
@@ -1391,7 +1558,7 @@
     public void testStartPlatformVpnFailedWithIkeNetworkLostException() throws Exception {
         final IkeNetworkLostException exception = new IkeNetworkLostException(
                 new Network(100));
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_NETWORK_ERROR, VpnManager.ERROR_CLASS_RECOVERABLE,
                 VpnManager.ERROR_CODE_NETWORK_LOST);
     }
@@ -1402,7 +1569,7 @@
         final IOException ioException = new IOException();
         final int errorCode = VpnManager.ERROR_CODE_NETWORK_IO;
         when(exception.getCause()).thenReturn(ioException);
-        setupPlatformVpnWithSpecificExceptionAndItsErrorCode(exception,
+        doTestPlatformVpnWithException(exception,
                 VpnManager.CATEGORY_EVENT_NETWORK_ERROR, VpnManager.ERROR_CLASS_RECOVERABLE,
                 errorCode);
     }
@@ -1411,7 +1578,7 @@
     public void testStartPlatformVpnIllegalArgumentExceptionInSetup() throws Exception {
         when(mIkev2SessionCreator.createIkeSession(any(), any(), any(), any(), any(), any()))
                 .thenThrow(new IllegalArgumentException());
-        final Vpn vpn = startLegacyVpn(createVpn(primaryUser.id), mVpnProfile);
+        final Vpn vpn = startLegacyVpn(createVpn(PRIMARY_USER.id), mVpnProfile);
         final NetworkCallback cb = triggerOnAvailableAndGetCallback();
 
         verifyInterfaceSetCfgWithFlags(IF_STATE_UP);
@@ -1431,18 +1598,18 @@
                 eq(AppOpsManager.MODE_ALLOWED));
 
         verify(mSystemServices).settingsSecurePutStringForUser(
-                eq(Settings.Secure.ALWAYS_ON_VPN_APP), eq(TEST_VPN_PKG), eq(primaryUser.id));
+                eq(Settings.Secure.ALWAYS_ON_VPN_APP), eq(TEST_VPN_PKG), eq(PRIMARY_USER.id));
         verify(mSystemServices).settingsSecurePutIntForUser(
                 eq(Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN), eq(lockdownEnabled ? 1 : 0),
-                eq(primaryUser.id));
+                eq(PRIMARY_USER.id));
         verify(mSystemServices).settingsSecurePutStringForUser(
-                eq(Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN_WHITELIST), eq(""), eq(primaryUser.id));
+                eq(Settings.Secure.ALWAYS_ON_VPN_LOCKDOWN_WHITELIST), eq(""), eq(PRIMARY_USER.id));
     }
 
     @Test
     public void testSetAndStartAlwaysOnVpn() throws Exception {
-        final Vpn vpn = createVpn(primaryUser.id);
-        setMockedUsers(primaryUser);
+        final Vpn vpn = createVpn(PRIMARY_USER.id);
+        setMockedUsers(PRIMARY_USER);
 
         // UID checks must return a different UID; otherwise it'll be treated as already prepared.
         final int uid = Process.myUid() + 1;
@@ -1459,7 +1626,7 @@
     }
 
     private Vpn startLegacyVpn(final Vpn vpn, final VpnProfile vpnProfile) throws Exception {
-        setMockedUsers(primaryUser);
+        setMockedUsers(PRIMARY_USER);
 
         // Dummy egress interface
         final LinkProperties lp = new LinkProperties();
@@ -1473,11 +1640,266 @@
         return vpn;
     }
 
+    private IkeSessionConnectionInfo createIkeConnectInfo() {
+        return new IkeSessionConnectionInfo(TEST_VPN_CLIENT_IP, TEST_VPN_SERVER_IP, TEST_NETWORK);
+    }
+
+    private IkeSessionConnectionInfo createIkeConnectInfo_2() {
+        return new IkeSessionConnectionInfo(
+                TEST_VPN_CLIENT_IP_2, TEST_VPN_SERVER_IP_2, TEST_NETWORK_2);
+    }
+
+    private IkeSessionConfiguration createIkeConfig(
+            IkeSessionConnectionInfo ikeConnectInfo, boolean isMobikeEnabled) {
+        final IkeSessionConfiguration.Builder builder =
+                new IkeSessionConfiguration.Builder(ikeConnectInfo);
+
+        if (isMobikeEnabled) {
+            builder.addIkeExtension(EXTENSION_TYPE_MOBIKE);
+        }
+
+        return builder.build();
+    }
+
+    private ChildSessionConfiguration createChildConfig() {
+        return new ChildSessionConfiguration.Builder(Arrays.asList(IN_TS), Arrays.asList(OUT_TS))
+                .addInternalAddress(new LinkAddress(TEST_VPN_INTERNAL_IP, IP4_PREFIX_LEN))
+                .addInternalDnsServer(TEST_VPN_INTERNAL_DNS)
+                .build();
+    }
+
+    private IpSecTransform createIpSecTransform() {
+        return new IpSecTransform(mContext, new IpSecConfig());
+    }
+
+    private void verifyApplyTunnelModeTransforms(int expectedTimes) throws Exception {
+        verify(mIpSecService, times(expectedTimes)).applyTunnelModeTransform(
+                eq(TEST_TUNNEL_RESOURCE_ID), eq(IpSecManager.DIRECTION_IN),
+                anyInt(), anyString());
+        verify(mIpSecService, times(expectedTimes)).applyTunnelModeTransform(
+                eq(TEST_TUNNEL_RESOURCE_ID), eq(IpSecManager.DIRECTION_OUT),
+                anyInt(), anyString());
+    }
+
+    private Pair<IkeSessionCallback, ChildSessionCallback> verifyCreateIkeAndCaptureCbs()
+            throws Exception {
+        final ArgumentCaptor<IkeSessionCallback> ikeCbCaptor =
+                ArgumentCaptor.forClass(IkeSessionCallback.class);
+        final ArgumentCaptor<ChildSessionCallback> childCbCaptor =
+                ArgumentCaptor.forClass(ChildSessionCallback.class);
+
+        verify(mIkev2SessionCreator, timeout(TEST_TIMEOUT_MS)).createIkeSession(
+                any(), any(), any(), any(), ikeCbCaptor.capture(), childCbCaptor.capture());
+
+        return new Pair<>(ikeCbCaptor.getValue(), childCbCaptor.getValue());
+    }
+
+    private static class PlatformVpnSnapshot {
+        public final Vpn vpn;
+        public final NetworkCallback nwCb;
+        public final IkeSessionCallback ikeCb;
+        public final ChildSessionCallback childCb;
+
+        PlatformVpnSnapshot(Vpn vpn, NetworkCallback nwCb,
+                IkeSessionCallback ikeCb, ChildSessionCallback childCb) {
+            this.vpn = vpn;
+            this.nwCb = nwCb;
+            this.ikeCb = ikeCb;
+            this.childCb = childCb;
+        }
+    }
+
+    private PlatformVpnSnapshot verifySetupPlatformVpn(IkeSessionConfiguration ikeConfig)
+            throws Exception {
+        doReturn(mMockNetworkAgent).when(mTestDeps)
+                .newNetworkAgent(
+                        any(), any(), anyString(), any(), any(), any(), any(), any());
+
+        final Vpn vpn = createVpnAndSetupUidChecks(AppOpsManager.OPSTR_ACTIVATE_PLATFORM_VPN);
+        when(mVpnProfileStore.get(vpn.getProfileNameForPackage(TEST_VPN_PKG)))
+                .thenReturn(mVpnProfile.encode());
+
+        vpn.startVpnProfile(TEST_VPN_PKG);
+        final NetworkCallback nwCb = triggerOnAvailableAndGetCallback();
+
+        // Mock the setup procedure by firing callbacks
+        final Pair<IkeSessionCallback, ChildSessionCallback> cbPair =
+                verifyCreateIkeAndCaptureCbs();
+        final IkeSessionCallback ikeCb = cbPair.first;
+        final ChildSessionCallback childCb = cbPair.second;
+
+        ikeCb.onOpened(ikeConfig);
+        childCb.onIpSecTransformCreated(createIpSecTransform(), IpSecManager.DIRECTION_IN);
+        childCb.onIpSecTransformCreated(createIpSecTransform(), IpSecManager.DIRECTION_OUT);
+        childCb.onOpened(createChildConfig());
+
+        // Verification VPN setup
+        verifyApplyTunnelModeTransforms(1);
+
+        ArgumentCaptor<LinkProperties> lpCaptor = ArgumentCaptor.forClass(LinkProperties.class);
+        ArgumentCaptor<NetworkCapabilities> ncCaptor =
+                ArgumentCaptor.forClass(NetworkCapabilities.class);
+        verify(mTestDeps).newNetworkAgent(
+                any(), any(), anyString(), ncCaptor.capture(), lpCaptor.capture(),
+                any(), any(), any());
+
+        // Check LinkProperties
+        final LinkProperties lp = lpCaptor.getValue();
+        final List<RouteInfo> expectedRoutes = Arrays.asList(
+                new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null /*gateway*/,
+                        TEST_IFACE_NAME, RouteInfo.RTN_UNICAST),
+                new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null /*gateway*/,
+                        TEST_IFACE_NAME, RTN_UNREACHABLE));
+        assertEquals(expectedRoutes, lp.getRoutes());
+
+        // Check internal addresses
+        final List<LinkAddress> expectedAddresses =
+                Arrays.asList(new LinkAddress(TEST_VPN_INTERNAL_IP, IP4_PREFIX_LEN));
+        assertEquals(expectedAddresses, lp.getLinkAddresses());
+
+        // Check internal DNS
+        assertEquals(Arrays.asList(TEST_VPN_INTERNAL_DNS), lp.getDnsServers());
+
+        // Check NetworkCapabilities
+        assertEquals(Arrays.asList(TEST_NETWORK), ncCaptor.getValue().getUnderlyingNetworks());
+
+        return new PlatformVpnSnapshot(vpn, nwCb, ikeCb, childCb);
+    }
+
     @Test
     public void testStartPlatformVpn() throws Exception {
-        startLegacyVpn(createVpn(primaryUser.id), mVpnProfile);
-        // TODO: Test the Ikev2VpnRunner started up properly. Relies on utility methods added in
-        // a subsequent patch.
+        final PlatformVpnSnapshot vpnSnapShot = verifySetupPlatformVpn(
+                createIkeConfig(createIkeConnectInfo(), true /* isMobikeEnabled */));
+        vpnSnapShot.vpn.mVpnRunner.exitVpnRunner();
+    }
+
+    @Test
+    public void testStartPlatformVpnMobility_mobikeEnabled() throws Exception {
+        final PlatformVpnSnapshot vpnSnapShot = verifySetupPlatformVpn(
+                createIkeConfig(createIkeConnectInfo(), true /* isMobikeEnabled */));
+
+        // Mock network loss and verify a cleanup task is scheduled
+        vpnSnapShot.nwCb.onLost(TEST_NETWORK);
+        verify(mExecutor).schedule(any(Runnable.class), anyLong(), any());
+
+        // Mock new network comes up and the cleanup task is cancelled
+        vpnSnapShot.nwCb.onAvailable(TEST_NETWORK_2);
+        verify(mScheduledFuture).cancel(anyBoolean());
+
+        // Verify MOBIKE is triggered
+        verify(mIkeSessionWrapper).setNetwork(TEST_NETWORK_2);
+
+        // Mock the MOBIKE procedure
+        vpnSnapShot.ikeCb.onIkeSessionConnectionInfoChanged(createIkeConnectInfo_2());
+        vpnSnapShot.childCb.onIpSecTransformsMigrated(
+                createIpSecTransform(), createIpSecTransform());
+
+        verify(mIpSecService).setNetworkForTunnelInterface(
+                eq(TEST_TUNNEL_RESOURCE_ID), eq(TEST_NETWORK_2), anyString());
+
+        // Expect 2 times: one for initial setup and one for MOBIKE
+        verifyApplyTunnelModeTransforms(2);
+
+        // Verify mNetworkCapabilities and mNetworkAgent are updated
+        assertEquals(
+                Collections.singletonList(TEST_NETWORK_2),
+                vpnSnapShot.vpn.mNetworkCapabilities.getUnderlyingNetworks());
+        verify(mMockNetworkAgent)
+                .setUnderlyingNetworks(Collections.singletonList(TEST_NETWORK_2));
+
+        vpnSnapShot.vpn.mVpnRunner.exitVpnRunner();
+    }
+
+    @Test
+    public void testStartPlatformVpnReestablishes_mobikeDisabled() throws Exception {
+        final PlatformVpnSnapshot vpnSnapShot = verifySetupPlatformVpn(
+                createIkeConfig(createIkeConnectInfo(), false /* isMobikeEnabled */));
+
+        // Forget the first IKE creation to be prepared to capture callbacks of the second
+        // IKE session
+        resetIkev2SessionCreator(mock(Vpn.IkeSessionWrapper.class));
+
+        // Mock network switch
+        vpnSnapShot.nwCb.onLost(TEST_NETWORK);
+        vpnSnapShot.nwCb.onAvailable(TEST_NETWORK_2);
+
+        // Verify the old IKE Session is killed
+        verify(mIkeSessionWrapper).kill();
+
+        // Capture callbacks of the new IKE Session
+        final Pair<IkeSessionCallback, ChildSessionCallback> cbPair =
+                verifyCreateIkeAndCaptureCbs();
+        final IkeSessionCallback ikeCb = cbPair.first;
+        final ChildSessionCallback childCb = cbPair.second;
+
+        // Mock the IKE Session setup
+        ikeCb.onOpened(createIkeConfig(createIkeConnectInfo_2(), false /* isMobikeEnabled */));
+
+        childCb.onIpSecTransformCreated(createIpSecTransform(), IpSecManager.DIRECTION_IN);
+        childCb.onIpSecTransformCreated(createIpSecTransform(), IpSecManager.DIRECTION_OUT);
+        childCb.onOpened(createChildConfig());
+
+        // Expect 2 times since there have been two Session setups
+        verifyApplyTunnelModeTransforms(2);
+
+        // Verify mNetworkCapabilities and mNetworkAgent are updated
+        assertEquals(
+                Collections.singletonList(TEST_NETWORK_2),
+                vpnSnapShot.vpn.mNetworkCapabilities.getUnderlyingNetworks());
+        verify(mMockNetworkAgent)
+                .setUnderlyingNetworks(Collections.singletonList(TEST_NETWORK_2));
+
+        vpnSnapShot.vpn.mVpnRunner.exitVpnRunner();
+    }
+
+    private void verifyHandlingNetworkLoss() throws Exception {
+        final ArgumentCaptor<LinkProperties> lpCaptor =
+                ArgumentCaptor.forClass(LinkProperties.class);
+        verify(mMockNetworkAgent).sendLinkProperties(lpCaptor.capture());
+        final LinkProperties lp = lpCaptor.getValue();
+
+        assertNull(lp.getInterfaceName());
+        final List<RouteInfo> expectedRoutes = Arrays.asList(
+                new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null /*gateway*/,
+                        null /*iface*/, RTN_UNREACHABLE),
+                new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null /*gateway*/,
+                        null /*iface*/, RTN_UNREACHABLE));
+        assertEquals(expectedRoutes, lp.getRoutes());
+    }
+
+    @Test
+    public void testStartPlatformVpnHandlesNetworkLoss_mobikeEnabled() throws Exception {
+        final PlatformVpnSnapshot vpnSnapShot = verifySetupPlatformVpn(
+                createIkeConfig(createIkeConnectInfo(), false /* isMobikeEnabled */));
+
+        // Forget the #sendLinkProperties during first setup.
+        reset(mMockNetworkAgent);
+
+        final ArgumentCaptor<Runnable> runnableCaptor =
+                ArgumentCaptor.forClass(Runnable.class);
+
+        // Mock network loss
+        vpnSnapShot.nwCb.onLost(TEST_NETWORK);
+
+        // Mock the grace period expires
+        verify(mExecutor).schedule(runnableCaptor.capture(), anyLong(), any());
+        runnableCaptor.getValue().run();
+
+        verifyHandlingNetworkLoss();
+    }
+
+    @Test
+    public void testStartPlatformVpnHandlesNetworkLoss_mobikeDisabled() throws Exception {
+        final PlatformVpnSnapshot vpnSnapShot = verifySetupPlatformVpn(
+                createIkeConfig(createIkeConnectInfo(), false /* isMobikeEnabled */));
+
+        // Forget the #sendLinkProperties during first setup.
+        reset(mMockNetworkAgent);
+
+        // Mock network loss
+        vpnSnapShot.nwCb.onLost(TEST_NETWORK);
+
+        verifyHandlingNetworkLoss();
     }
 
     @Test
@@ -1490,6 +1912,16 @@
         startRacoon("hostname", "5.6.7.8"); // address returned by deps.resolve
     }
 
+    @Test
+    public void testStartPptp() throws Exception {
+        startPptp(true /* useMppe */);
+    }
+
+    @Test
+    public void testStartPptp_NoMppe() throws Exception {
+        startPptp(false /* useMppe */);
+    }
+
     private void assertTransportInfoMatches(NetworkCapabilities nc, int type) {
         assertNotNull(nc);
         VpnTransportInfo ti = (VpnTransportInfo) nc.getTransportInfo();
@@ -1497,6 +1929,48 @@
         assertEquals(type, ti.getType());
     }
 
+    private void startPptp(boolean useMppe) throws Exception {
+        final VpnProfile profile = new VpnProfile("testProfile" /* key */);
+        profile.type = VpnProfile.TYPE_PPTP;
+        profile.name = "testProfileName";
+        profile.username = "userName";
+        profile.password = "thePassword";
+        profile.server = "192.0.2.123";
+        profile.mppe = useMppe;
+
+        doReturn(new Network[] { new Network(101) }).when(mConnectivityManager).getAllNetworks();
+        doReturn(new Network(102)).when(mConnectivityManager).registerNetworkAgent(any(), any(),
+                any(), any(), any(), any(), anyInt());
+
+        final Vpn vpn = startLegacyVpn(createVpn(PRIMARY_USER.id), profile);
+        final TestDeps deps = (TestDeps) vpn.mDeps;
+
+        testAndCleanup(() -> {
+            final String[] mtpdArgs = deps.mtpdArgs.get(10, TimeUnit.SECONDS);
+            final String[] argsPrefix = new String[]{
+                    EGRESS_IFACE, "pptp", profile.server, "1723", "name", profile.username,
+                    "password", profile.password, "linkname", "vpn", "refuse-eap", "nodefaultroute",
+                    "usepeerdns", "idle", "1800", "mtu", "1270", "mru", "1270"
+            };
+            assertArrayEquals(argsPrefix, Arrays.copyOf(mtpdArgs, argsPrefix.length));
+            if (useMppe) {
+                assertEquals(argsPrefix.length + 2, mtpdArgs.length);
+                assertEquals("+mppe", mtpdArgs[argsPrefix.length]);
+                assertEquals("-pap", mtpdArgs[argsPrefix.length + 1]);
+            } else {
+                assertEquals(argsPrefix.length + 1, mtpdArgs.length);
+                assertEquals("nomppe", mtpdArgs[argsPrefix.length]);
+            }
+
+            verify(mConnectivityManager, timeout(10_000)).registerNetworkAgent(any(), any(),
+                    any(), any(), any(), any(), anyInt());
+        }, () -> { // Cleanup
+                vpn.mVpnRunner.exitVpnRunner();
+                deps.getStateFile().delete(); // set to delete on exit, but this deletes it earlier
+                vpn.mVpnRunner.join(10_000); // wait for up to 10s for the runner to die and cleanup
+            });
+    }
+
     public void startRacoon(final String serverAddr, final String expectedAddr)
             throws Exception {
         final ConditionVariable legacyRunnerReady = new ConditionVariable();
@@ -1519,7 +1993,7 @@
                     legacyRunnerReady.open();
                     return new Network(102);
                 });
-        final Vpn vpn = startLegacyVpn(createVpn(primaryUser.id), profile);
+        final Vpn vpn = startLegacyVpn(createVpn(PRIMARY_USER.id), profile);
         final TestDeps deps = (TestDeps) vpn.mDeps;
         try {
             // udppsk and 1701 are the values for TYPE_L2TP_IPSEC_PSK
@@ -1560,7 +2034,8 @@
         }
     }
 
-    private final class TestDeps extends Vpn.Dependencies {
+    // Make it public and un-final so as to spy it
+    public class TestDeps extends Vpn.Dependencies {
         public final CompletableFuture<String[]> racoonArgs = new CompletableFuture();
         public final CompletableFuture<String[]> mtpdArgs = new CompletableFuture();
         public final File mStateFile;
@@ -1694,6 +2169,17 @@
         public DeviceIdleInternal getDeviceIdleInternal() {
             return mDeviceIdleInternal;
         }
+
+        @Override
+        public long getNextRetryDelaySeconds(int retryCount) {
+            // Simply return retryCount as the delay seconds for retrying.
+            return retryCount;
+        }
+
+        @Override
+        public ScheduledThreadPoolExecutor newScheduledThreadPoolExecutor() {
+            return mExecutor;
+        }
     }
 
     /**
@@ -1705,7 +2191,7 @@
         when(mContext.createContextAsUser(eq(UserHandle.of(userId)), anyInt()))
                 .thenReturn(asUserContext);
         final TestLooper testLooper = new TestLooper();
-        final Vpn vpn = new Vpn(testLooper.getLooper(), mContext, new TestDeps(), mNetService,
+        final Vpn vpn = new Vpn(testLooper.getLooper(), mContext, mTestDeps, mNetService,
                 mNetd, userId, mVpnProfileStore, mSystemServices, mIkev2SessionCreator);
         verify(mConnectivityManager, times(1)).registerNetworkProvider(argThat(
                 provider -> provider.getName().contains("VpnNetworkProvider")
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManagerTests.java b/tests/unit/java/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManagerTests.java
new file mode 100644
index 0000000..f84e2d8
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/ConnectivityMonitorWithConnectivityManagerTests.java
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.ConnectivityManager.NetworkCallback;
+import android.net.Network;
+import android.net.NetworkRequest;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/** Tests for {@link ConnectivityMonitor}. */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class ConnectivityMonitorWithConnectivityManagerTests {
+    @Mock private Context mContext;
+    @Mock private ConnectivityMonitor.Listener mockListener;
+    @Mock private ConnectivityManager mConnectivityManager;
+
+    private ConnectivityMonitorWithConnectivityManager monitor;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        doReturn(mConnectivityManager).when(mContext)
+                .getSystemService(Context.CONNECTIVITY_SERVICE);
+        monitor = new ConnectivityMonitorWithConnectivityManager(mContext, mockListener);
+    }
+
+    @Test
+    public void testInitialState_shouldNotRegisterNetworkCallback() {
+        verifyNetworkCallbackRegistered(0 /* time */);
+        verifyNetworkCallbackUnregistered(0 /* time */);
+    }
+
+    @Test
+    public void testStartDiscovery_shouldRegisterNetworkCallback() {
+        monitor.startWatchingConnectivityChanges();
+
+        verifyNetworkCallbackRegistered(1 /* time */);
+        verifyNetworkCallbackUnregistered(0 /* time */);
+    }
+
+    @Test
+    public void testStartDiscoveryTwice_shouldRegisterOneNetworkCallback() {
+        monitor.startWatchingConnectivityChanges();
+        monitor.startWatchingConnectivityChanges();
+
+        verifyNetworkCallbackRegistered(1 /* time */);
+        verifyNetworkCallbackUnregistered(0 /* time */);
+    }
+
+    @Test
+    public void testStopDiscovery_shouldUnregisterNetworkCallback() {
+        monitor.startWatchingConnectivityChanges();
+        monitor.stopWatchingConnectivityChanges();
+
+        verifyNetworkCallbackRegistered(1 /* time */);
+        verifyNetworkCallbackUnregistered(1 /* time */);
+    }
+
+    @Test
+    public void testStopDiscoveryTwice_shouldUnregisterNetworkCallback() {
+        monitor.startWatchingConnectivityChanges();
+        monitor.stopWatchingConnectivityChanges();
+
+        verifyNetworkCallbackRegistered(1 /* time */);
+        verifyNetworkCallbackUnregistered(1 /* time */);
+    }
+
+    @Test
+    public void testIntentFired_shouldNotifyListener() {
+        InOrder inOrder = inOrder(mockListener);
+        monitor.startWatchingConnectivityChanges();
+
+        final ArgumentCaptor<NetworkCallback> callbackCaptor =
+                ArgumentCaptor.forClass(NetworkCallback.class);
+        verify(mConnectivityManager, times(1)).registerNetworkCallback(
+                any(NetworkRequest.class), callbackCaptor.capture());
+
+        final NetworkCallback callback = callbackCaptor.getValue();
+        final Network testNetwork = new Network(1 /* netId */);
+
+        // Simulate network available.
+        callback.onAvailable(testNetwork);
+        inOrder.verify(mockListener).onConnectivityChanged();
+
+        // Simulate network lost.
+        callback.onLost(testNetwork);
+        inOrder.verify(mockListener).onConnectivityChanged();
+
+        // Simulate network unavailable.
+        callback.onUnavailable();
+        inOrder.verify(mockListener).onConnectivityChanged();
+    }
+
+    private void verifyNetworkCallbackRegistered(int time) {
+        verify(mConnectivityManager, times(time)).registerNetworkCallback(
+                any(NetworkRequest.class), any(NetworkCallback.class));
+    }
+
+    private void verifyNetworkCallbackUnregistered(int time) {
+        verify(mConnectivityManager, times(time))
+                .unregisterNetworkCallback(any(NetworkCallback.class));
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsDiscoveryManagerTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsDiscoveryManagerTests.java
new file mode 100644
index 0000000..3e3c3bf
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsDiscoveryManagerTests.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.annotation.NonNull;
+import android.text.TextUtils;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.io.IOException;
+import java.util.Collections;
+
+/** Tests for {@link MdnsDiscoveryManager}. */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsDiscoveryManagerTests {
+
+    private static final String SERVICE_TYPE_1 = "_googlecast._tcp.local";
+    private static final String SERVICE_TYPE_2 = "_test._tcp.local";
+
+    @Mock private ExecutorProvider executorProvider;
+    @Mock private MdnsSocketClient socketClient;
+    @Mock private MdnsServiceTypeClient mockServiceTypeClientOne;
+    @Mock private MdnsServiceTypeClient mockServiceTypeClientTwo;
+
+    @Mock MdnsServiceBrowserListener mockListenerOne;
+    @Mock MdnsServiceBrowserListener mockListenerTwo;
+    private MdnsDiscoveryManager discoveryManager;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        when(mockServiceTypeClientOne.getServiceTypeLabels())
+                .thenReturn(TextUtils.split(SERVICE_TYPE_1, "\\."));
+        when(mockServiceTypeClientTwo.getServiceTypeLabels())
+                .thenReturn(TextUtils.split(SERVICE_TYPE_2, "\\."));
+
+        discoveryManager = new MdnsDiscoveryManager(executorProvider, socketClient) {
+                    @Override
+                    MdnsServiceTypeClient createServiceTypeClient(@NonNull String serviceType) {
+                        if (serviceType.equals(SERVICE_TYPE_1)) {
+                            return mockServiceTypeClientOne;
+                        } else if (serviceType.equals(SERVICE_TYPE_2)) {
+                            return mockServiceTypeClientTwo;
+                        }
+                        return null;
+                    }
+                };
+    }
+
+    @Test
+    public void registerListener_unregisterListener() throws IOException {
+        discoveryManager.registerListener(
+                SERVICE_TYPE_1, mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        verify(socketClient).startDiscovery();
+        verify(mockServiceTypeClientOne)
+                .startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        when(mockServiceTypeClientOne.stopSendAndReceive(mockListenerOne)).thenReturn(true);
+        discoveryManager.unregisterListener(SERVICE_TYPE_1, mockListenerOne);
+        verify(mockServiceTypeClientOne).stopSendAndReceive(mockListenerOne);
+        verify(socketClient).stopDiscovery();
+    }
+
+    @Test
+    public void registerMultipleListeners() throws IOException {
+        discoveryManager.registerListener(
+                SERVICE_TYPE_1, mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        verify(socketClient).startDiscovery();
+        verify(mockServiceTypeClientOne)
+                .startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        discoveryManager.registerListener(
+                SERVICE_TYPE_2, mockListenerTwo, MdnsSearchOptions.getDefaultOptions());
+        verify(mockServiceTypeClientTwo)
+                .startSendAndReceive(mockListenerTwo, MdnsSearchOptions.getDefaultOptions());
+    }
+
+    @Test
+    public void onResponseReceived() {
+        discoveryManager.registerListener(
+                SERVICE_TYPE_1, mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        discoveryManager.registerListener(
+                SERVICE_TYPE_2, mockListenerTwo, MdnsSearchOptions.getDefaultOptions());
+
+        MdnsResponse responseForServiceTypeOne = createMockResponse(SERVICE_TYPE_1);
+        discoveryManager.onResponseReceived(responseForServiceTypeOne);
+        verify(mockServiceTypeClientOne).processResponse(responseForServiceTypeOne);
+
+        MdnsResponse responseForServiceTypeTwo = createMockResponse(SERVICE_TYPE_2);
+        discoveryManager.onResponseReceived(responseForServiceTypeTwo);
+        verify(mockServiceTypeClientTwo).processResponse(responseForServiceTypeTwo);
+
+        MdnsResponse responseForSubtype = createMockResponse("subtype._sub._googlecast._tcp.local");
+        discoveryManager.onResponseReceived(responseForSubtype);
+        verify(mockServiceTypeClientOne).processResponse(responseForSubtype);
+    }
+
+    private MdnsResponse createMockResponse(String serviceType) {
+        MdnsPointerRecord mockPointerRecord = mock(MdnsPointerRecord.class);
+        MdnsResponse mockResponse = mock(MdnsResponse.class);
+        when(mockResponse.getPointerRecords())
+                .thenReturn(Collections.singletonList(mockPointerRecord));
+        when(mockPointerRecord.getName()).thenReturn(TextUtils.split(serviceType, "\\."));
+        return mockResponse;
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsPacketReaderTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsPacketReaderTests.java
new file mode 100644
index 0000000..19d8a00
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsPacketReaderTests.java
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.Locale;
+
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsPacketReaderTests {
+
+    @Test
+    public void testLimits() throws IOException {
+        byte[] data = new byte[25];
+        DatagramPacket datagramPacket = new DatagramPacket(data, data.length);
+
+        // After creating a new reader, confirm that the remaining is equal to the packet length
+        // (or that there is no temporary limit).
+        MdnsPacketReader packetReader = new MdnsPacketReader(datagramPacket);
+        assertEquals(data.length, packetReader.getRemaining());
+
+        // Confirm that we can set the temporary limit to 0.
+        packetReader.setLimit(0);
+        assertEquals(0, packetReader.getRemaining());
+
+        // Confirm that we can clear the temporary limit, and restore to the length of the packet.
+        packetReader.clearLimit();
+        assertEquals(data.length, packetReader.getRemaining());
+
+        // Confirm that we can set the temporary limit to the actual length of the packet.
+        // While parsing packets, it is common to set the limit to the length of the packet.
+        packetReader.setLimit(data.length);
+        assertEquals(data.length, packetReader.getRemaining());
+
+        // Confirm that we ignore negative limits.
+        packetReader.setLimit(-10);
+        assertEquals(data.length, packetReader.getRemaining());
+
+        // Confirm that we can set the temporary limit to something less than the packet length.
+        packetReader.setLimit(data.length / 2);
+        assertEquals(data.length / 2, packetReader.getRemaining());
+
+        // Confirm that we throw an exception if trying to set the temporary limit beyond the
+        // packet length.
+        packetReader.clearLimit();
+        try {
+            packetReader.setLimit(data.length * 2 + 1);
+            fail("Should have thrown an IOException when trying to set the temporary limit beyond "
+                    + "the packet length");
+        } catch (IOException e) {
+            // Expected
+        } catch (Exception e) {
+            fail(String.format(
+                    Locale.ROOT,
+                    "Should not have thrown any other exception except " + "for IOException: %s",
+                    e.getMessage()));
+        }
+        assertEquals(data.length, packetReader.getRemaining());
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsRecordTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsRecordTests.java
new file mode 100644
index 0000000..fdb4d4a
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsRecordTests.java
@@ -0,0 +1,324 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import android.util.Log;
+
+import com.android.net.module.util.HexDump;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetSocketAddress;
+import java.util.List;
+
+// The record test data does not use compressed names (label pointers), since that would require
+// additional data to populate the label dictionary accordingly.
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsRecordTests {
+    private static final String TAG = "MdnsRecordTests";
+    private static final int MAX_PACKET_SIZE = 4096;
+    private static final InetSocketAddress MULTICAST_IPV4_ADDRESS =
+            new InetSocketAddress(MdnsConstants.getMdnsIPv4Address(), MdnsConstants.MDNS_PORT);
+    private static final InetSocketAddress MULTICAST_IPV6_ADDRESS =
+            new InetSocketAddress(MdnsConstants.getMdnsIPv6Address(), MdnsConstants.MDNS_PORT);
+
+    @Test
+    public void testInet4AddressRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "0474657374000001" + "0001000011940004" + "0A010203");
+        assertNotNull(dataIn);
+        String dataInText = HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        assertEquals("test", name[0]);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_A, type);
+
+        MdnsInetAddressRecord record = new MdnsInetAddressRecord(name, MdnsRecord.TYPE_A, reader);
+        Inet4Address addr = record.getInet4Address();
+        assertEquals("/10.1.2.3", addr.toString());
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV4_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        assertEquals(dataInText, dataOutText);
+    }
+
+    @Test
+    public void testTypeAAAInet6AddressRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "047465737400001C"
+                        + "0001000011940010"
+                        + "AABBCCDD11223344"
+                        + "A0B0C0D010203040");
+        assertNotNull(dataIn);
+        String dataInText = HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        packet.setSocketAddress(
+                new InetSocketAddress(MdnsConstants.getMdnsIPv6Address(), MdnsConstants.MDNS_PORT));
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_AAAA, type);
+
+        MdnsInetAddressRecord record = new MdnsInetAddressRecord(name, MdnsRecord.TYPE_AAAA,
+                reader);
+        assertNull(record.getInet4Address());
+        Inet6Address addr = record.getInet6Address();
+        assertEquals("/aabb:ccdd:1122:3344:a0b0:c0d0:1020:3040", addr.toString());
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV6_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        assertEquals(dataInText, dataOutText);
+    }
+
+    @Test
+    public void testTypeAAAInet4AddressRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "047465737400001C"
+                        + "0001000011940010"
+                        + "0000000000000000"
+                        + "0000FFFF10203040");
+        assertNotNull(dataIn);
+        HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        packet.setSocketAddress(
+                new InetSocketAddress(MdnsConstants.getMdnsIPv4Address(), MdnsConstants.MDNS_PORT));
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_AAAA, type);
+
+        MdnsInetAddressRecord record = new MdnsInetAddressRecord(name, MdnsRecord.TYPE_AAAA,
+                reader);
+        assertNull(record.getInet6Address());
+        Inet4Address addr = record.getInet4Address();
+        assertEquals("/16.32.48.64", addr.toString());
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV4_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        final byte[] expectedDataIn =
+                HexDump.hexStringToByteArray("047465737400001C000100001194000410203040");
+        assertNotNull(expectedDataIn);
+        String expectedDataInText = HexDump.dumpHexString(expectedDataIn, 0, expectedDataIn.length);
+
+        assertEquals(expectedDataInText, dataOutText);
+    }
+
+    @Test
+    public void testPointerRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "047465737400000C"
+                        + "000100001194000E"
+                        + "03666F6F03626172"
+                        + "047175787800");
+        assertNotNull(dataIn);
+        String dataInText = HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_PTR, type);
+
+        MdnsPointerRecord record = new MdnsPointerRecord(name, reader);
+        String[] pointer = record.getPointer();
+        assertEquals("foo.bar.quxx", MdnsRecord.labelsToString(pointer));
+
+        assertFalse(record.hasSubtype());
+        assertNull(record.getSubtype());
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV4_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        assertEquals(dataInText, dataOutText);
+    }
+
+    @Test
+    public void testServiceRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "0474657374000021"
+                        + "0001000011940014"
+                        + "000100FF1F480366"
+                        + "6F6F036261720471"
+                        + "75787800");
+        assertNotNull(dataIn);
+        String dataInText = HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_SRV, type);
+
+        MdnsServiceRecord record = new MdnsServiceRecord(name, reader);
+
+        int servicePort = record.getServicePort();
+        assertEquals(8008, servicePort);
+
+        String serviceHost = MdnsRecord.labelsToString(record.getServiceHost());
+        assertEquals("foo.bar.quxx", serviceHost);
+
+        assertEquals(1, record.getServicePriority());
+        assertEquals(255, record.getServiceWeight());
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV4_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        assertEquals(dataInText, dataOutText);
+    }
+
+    @Test
+    public void testTextRecord() throws IOException {
+        final byte[] dataIn = HexDump.hexStringToByteArray(
+                "0474657374000010"
+                        + "0001000011940024"
+                        + "0D613D68656C6C6F"
+                        + "2074686572650C62"
+                        + "3D31323334353637"
+                        + "3839300878797A3D"
+                        + "21402324");
+        assertNotNull(dataIn);
+        String dataInText = HexDump.dumpHexString(dataIn, 0, dataIn.length);
+
+        // Decode
+        DatagramPacket packet = new DatagramPacket(dataIn, dataIn.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+
+        String[] name = reader.readLabels();
+        assertNotNull(name);
+        assertEquals(1, name.length);
+        String fqdn = MdnsRecord.labelsToString(name);
+        assertEquals("test", fqdn);
+
+        int type = reader.readUInt16();
+        assertEquals(MdnsRecord.TYPE_TXT, type);
+
+        MdnsTextRecord record = new MdnsTextRecord(name, reader);
+
+        List<String> strings = record.getStrings();
+        assertNotNull(strings);
+        assertEquals(3, strings.size());
+
+        assertEquals("a=hello there", strings.get(0));
+        assertEquals("b=1234567890", strings.get(1));
+        assertEquals("xyz=!@#$", strings.get(2));
+
+        // Encode
+        MdnsPacketWriter writer = new MdnsPacketWriter(MAX_PACKET_SIZE);
+        record.write(writer, record.getReceiptTime());
+
+        packet = writer.getPacket(MULTICAST_IPV4_ADDRESS);
+        byte[] dataOut = packet.getData();
+
+        String dataOutText = HexDump.dumpHexString(dataOut, 0, packet.getLength());
+        Log.d(TAG, dataOutText);
+
+        assertEquals(dataInText, dataOutText);
+    }
+}
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
new file mode 100644
index 0000000..ea9156c
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
@@ -0,0 +1,237 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.server.connectivity.mdns.MdnsResponseDecoder.Clock;
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+
+import com.android.net.module.util.HexDump;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetSocketAddress;
+import java.util.LinkedList;
+import java.util.List;
+
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsResponseDecoderTests {
+    private static final byte[] data = HexDump.hexStringToByteArray(
+            "0000840000000004"
+            + "00000003134A6F68"
+            + "6E6E792773204368"
+            + "726F6D6563617374"
+            + "0B5F676F6F676C65"
+            + "63617374045F7463"
+            + "70056C6F63616C00"
+            + "0010800100001194"
+            + "006C2369643D3937"
+            + "3062663534376237"
+            + "3533666336336332"
+            + "6432613336626238"
+            + "3936616261380576"
+            + "653D30320D6D643D"
+            + "4368726F6D656361"
+            + "73741269633D2F73"
+            + "657475702F69636F"
+            + "6E2E706E6716666E"
+            + "3D4A6F686E6E7927"
+            + "73204368726F6D65"
+            + "636173740463613D"
+            + "350473743D30095F"
+            + "7365727669636573"
+            + "075F646E732D7364"
+            + "045F756470C03100"
+            + "0C00010000119400"
+            + "02C020C020000C00"
+            + "01000011940002C0"
+            + "0CC00C0021800100"
+            + "000078001C000000"
+            + "001F49134A6F686E"
+            + "6E79277320436872"
+            + "6F6D6563617374C0"
+            + "31C0F30001800100"
+            + "0000780004C0A864"
+            + "68C0F3002F800100"
+            + "0000780005C0F300"
+            + "0140C00C002F8001"
+            + "000011940009C00C"
+            + "00050000800040");
+
+    private static final byte[] data6 = HexDump.hexStringToByteArray(
+            "0000840000000001000000030B5F676F6F676C656361737404"
+            + "5F746370056C6F63616C00000C000100000078003330476F6F676C"
+            + "652D486F6D652D4D61782D61363836666331323961366638636265"
+            + "31643636353139343065336164353766C00CC02E00108001000011"
+            + "9400C02369643D6136383666633132396136663863626531643636"
+            + "3531393430653361643537662363643D4133304233303032363546"
+            + "36384341313233353532434639344141353742314613726D3D4335"
+            + "35393134383530383841313638330576653D3035126D643D476F6F"
+            + "676C6520486F6D65204D61781269633D2F73657475702F69636F6E"
+            + "2E706E6710666E3D417474696320737065616B65720863613D3130"
+            + "3234340473743D320F62733D464138464341363734453537046E66"
+            + "3D320372733DC02E0021800100000078002D000000001F49246136"
+            + "3836666331322D396136662D386362652D316436362D3531393430"
+            + "65336164353766C01DC13F001C8001000000780010200033330000"
+            + "0000DA6C63FFFE7C74830109018001000000780004C0A801026C6F"
+            + "63616C0000018001000000780004C0A8010A000001800100000078"
+            + "0004C0A8010A00000000000000");
+
+    private static final String DUMMY_CAST_SERVICE_NAME = "_googlecast";
+    private static final String[] DUMMY_CAST_SERVICE_TYPE =
+            new String[] {DUMMY_CAST_SERVICE_NAME, "_tcp", "local"};
+
+    private final List<MdnsResponse> responses = new LinkedList<>();
+
+    private final Clock mClock = mock(Clock.class);
+
+    @Before
+    public void setUp() {
+        MdnsResponseDecoder decoder = new MdnsResponseDecoder(mClock, DUMMY_CAST_SERVICE_TYPE);
+        assertNotNull(data);
+        DatagramPacket packet = new DatagramPacket(data, data.length);
+        packet.setSocketAddress(
+                new InetSocketAddress(MdnsConstants.getMdnsIPv4Address(), MdnsConstants.MDNS_PORT));
+        responses.clear();
+        int errorCode = decoder.decode(packet, responses);
+        assertEquals(MdnsResponseDecoder.SUCCESS, errorCode);
+        assertEquals(1, responses.size());
+    }
+
+    @Test
+    public void testDecodeWithNullServiceType() {
+        MdnsResponseDecoder decoder = new MdnsResponseDecoder(mClock, null);
+        assertNotNull(data);
+        DatagramPacket packet = new DatagramPacket(data, data.length);
+        packet.setSocketAddress(
+                new InetSocketAddress(MdnsConstants.getMdnsIPv4Address(), MdnsConstants.MDNS_PORT));
+        responses.clear();
+        int errorCode = decoder.decode(packet, responses);
+        assertEquals(MdnsResponseDecoder.SUCCESS, errorCode);
+        assertEquals(2, responses.size());
+    }
+
+    @Test
+    public void testDecodeMultipleAnswerPacket() throws IOException {
+        MdnsResponse response = responses.get(0);
+        assertTrue(response.isComplete());
+
+        MdnsInetAddressRecord inet4AddressRecord = response.getInet4AddressRecord();
+        Inet4Address inet4Addr = inet4AddressRecord.getInet4Address();
+
+        assertNotNull(inet4Addr);
+        assertEquals("/192.168.100.104", inet4Addr.toString());
+
+        MdnsServiceRecord serviceRecord = response.getServiceRecord();
+        String serviceName = serviceRecord.getServiceName();
+        assertEquals(DUMMY_CAST_SERVICE_NAME, serviceName);
+
+        String serviceInstanceName = serviceRecord.getServiceInstanceName();
+        assertEquals("Johnny's Chromecast", serviceInstanceName);
+
+        String serviceHost = MdnsRecord.labelsToString(serviceRecord.getServiceHost());
+        assertEquals("Johnny's Chromecast.local", serviceHost);
+
+        int serviceProto = serviceRecord.getServiceProtocol();
+        assertEquals(MdnsServiceRecord.PROTO_TCP, serviceProto);
+
+        int servicePort = serviceRecord.getServicePort();
+        assertEquals(8009, servicePort);
+
+        int servicePriority = serviceRecord.getServicePriority();
+        assertEquals(0, servicePriority);
+
+        int serviceWeight = serviceRecord.getServiceWeight();
+        assertEquals(0, serviceWeight);
+
+        MdnsTextRecord textRecord = response.getTextRecord();
+        List<String> textStrings = textRecord.getStrings();
+        assertEquals(7, textStrings.size());
+        assertEquals("id=970bf547b753fc63c2d2a36bb896aba8", textStrings.get(0));
+        assertEquals("ve=02", textStrings.get(1));
+        assertEquals("md=Chromecast", textStrings.get(2));
+        assertEquals("ic=/setup/icon.png", textStrings.get(3));
+        assertEquals("fn=Johnny's Chromecast", textStrings.get(4));
+        assertEquals("ca=5", textStrings.get(5));
+        assertEquals("st=0", textStrings.get(6));
+    }
+
+    @Test
+    public void testDecodeIPv6AnswerPacket() throws IOException {
+        MdnsResponseDecoder decoder = new MdnsResponseDecoder(mClock, DUMMY_CAST_SERVICE_TYPE);
+        assertNotNull(data6);
+        DatagramPacket packet = new DatagramPacket(data6, data6.length);
+        packet.setSocketAddress(
+                new InetSocketAddress(MdnsConstants.getMdnsIPv6Address(), MdnsConstants.MDNS_PORT));
+
+        responses.clear();
+        int errorCode = decoder.decode(packet, responses);
+        assertEquals(MdnsResponseDecoder.SUCCESS, errorCode);
+
+        MdnsResponse response = responses.get(0);
+        assertTrue(response.isComplete());
+
+        MdnsInetAddressRecord inet6AddressRecord = response.getInet6AddressRecord();
+        assertNotNull(inet6AddressRecord);
+        Inet4Address inet4Addr = inet6AddressRecord.getInet4Address();
+        assertNull(inet4Addr);
+
+        Inet6Address inet6Addr = inet6AddressRecord.getInet6Address();
+        assertNotNull(inet6Addr);
+        assertEquals(inet6Addr.getHostAddress(), "2000:3333::da6c:63ff:fe7c:7483");
+    }
+
+    @Test
+    public void testIsComplete() {
+        MdnsResponse response = responses.get(0);
+        assertTrue(response.isComplete());
+
+        response.clearPointerRecords();
+        assertFalse(response.isComplete());
+
+        response = responses.get(0);
+        response.setInet4AddressRecord(null);
+        assertFalse(response.isComplete());
+
+        response = responses.get(0);
+        response.setInet6AddressRecord(null);
+        assertFalse(response.isComplete());
+
+        response = responses.get(0);
+        response.setServiceRecord(null);
+        assertFalse(response.isComplete());
+
+        response = responses.get(0);
+        response.setTextRecord(null);
+        assertFalse(response.isComplete());
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java
new file mode 100644
index 0000000..ae16f2b
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java
@@ -0,0 +1,305 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import com.android.net.module.util.HexDump;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.Arrays;
+import java.util.List;
+
+// The record test data does not use compressed names (label pointers), since that would require
+// additional data to populate the label dictionary accordingly.
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsResponseTests {
+    private static final String TAG = "MdnsResponseTests";
+    // MDNS response packet for name "test" with an IPv4 address of 10.1.2.3
+    private static final byte[] dataIn_ipv4_1 = HexDump.hexStringToByteArray(
+            "0474657374000001" + "0001000011940004" + "0A010203");
+    // MDNS response packet for name "tess" with an IPv4 address of 10.1.2.4
+    private static final byte[] dataIn_ipv4_2 = HexDump.hexStringToByteArray(
+            "0474657373000001" + "0001000011940004" + "0A010204");
+    // MDNS response w/name "test" & IPv6 address of aabb:ccdd:1122:3344:a0b0:c0d0:1020:3040
+    private static final byte[] dataIn_ipv6_1 = HexDump.hexStringToByteArray(
+            "047465737400001C" + "0001000011940010" + "AABBCCDD11223344" + "A0B0C0D010203040");
+    // MDNS response w/name "test" & IPv6 address of aabb:ccdd:1122:3344:a0b0:c0d0:1020:3030
+    private static final byte[] dataIn_ipv6_2 = HexDump.hexStringToByteArray(
+            "047465737400001C" + "0001000011940010" + "AABBCCDD11223344" + "A0B0C0D010203030");
+    // MDNS response w/name "test" & PTR to foo.bar.quxx
+    private static final byte[] dataIn_ptr_1 = HexDump.hexStringToByteArray(
+            "047465737400000C" + "000100001194000E" + "03666F6F03626172" + "047175787800");
+    // MDNS response w/name "test" & PTR to foo.bar.quxy
+    private static final byte[] dataIn_ptr_2 = HexDump.hexStringToByteArray(
+            "047465737400000C" + "000100001194000E" + "03666F6F03626172" + "047175787900");
+    // MDNS response w/name "test" & Service for host foo.bar.quxx
+    private static final byte[] dataIn_service_1 = HexDump.hexStringToByteArray(
+            "0474657374000021"
+            + "0001000011940014"
+            + "000100FF1F480366"
+            + "6F6F036261720471"
+            + "75787800");
+    // MDNS response w/name "test" & Service for host test
+    private static final byte[] dataIn_service_2 = HexDump.hexStringToByteArray(
+            "0474657374000021" + "000100001194000B" + "000100FF1F480474" + "657374");
+    // MDNS response w/name "test" & the following text strings:
+    // "a=hello there", "b=1234567890", and "xyz=!$$$"
+    private static final byte[] dataIn_text_1 = HexDump.hexStringToByteArray(
+            "0474657374000010"
+            + "0001000011940024"
+            + "0D613D68656C6C6F"
+            + "2074686572650C62"
+            + "3D31323334353637"
+            + "3839300878797A3D"
+            + "21242424");
+    // MDNS response w/name "test" & the following text strings:
+    // "a=hello there", "b=1234567890", and "xyz=!@#$"
+    private static final byte[] dataIn_text_2 = HexDump.hexStringToByteArray(
+            "0474657374000010"
+            + "0001000011940024"
+            + "0D613D68656C6C6F"
+            + "2074686572650C62"
+            + "3D31323334353637"
+            + "3839300878797A3D"
+            + "21402324");
+
+    // The following helper classes act as wrappers so that IPv4 and IPv6 address records can
+    // be explicitly created by type using same constructor signature as all other records.
+    static class MdnsInet4AddressRecord extends MdnsInetAddressRecord {
+        public MdnsInet4AddressRecord(String[] name, MdnsPacketReader reader) throws IOException {
+            super(name, MdnsRecord.TYPE_A, reader);
+        }
+    }
+
+    static class MdnsInet6AddressRecord extends MdnsInetAddressRecord {
+        public MdnsInet6AddressRecord(String[] name, MdnsPacketReader reader) throws IOException {
+            super(name, MdnsRecord.TYPE_AAAA, reader);
+        }
+    }
+
+    // This helper class just wraps the data bytes of a response packet with the contained record
+    // type.
+    // Its only purpose is to make the test code a bit more readable.
+    static class PacketAndRecordClass {
+        public final byte[] packetData;
+        public final Class<?> recordClass;
+
+        public PacketAndRecordClass() {
+            packetData = null;
+            recordClass = null;
+        }
+
+        public PacketAndRecordClass(byte[] data, Class<?> c) {
+            packetData = data;
+            recordClass = c;
+        }
+    }
+
+    // Construct an MdnsResponse with the specified data packets applied.
+    private MdnsResponse makeMdnsResponse(long time, List<PacketAndRecordClass> responseList)
+            throws IOException {
+        MdnsResponse response = new MdnsResponse(time);
+        for (PacketAndRecordClass responseData : responseList) {
+            DatagramPacket packet =
+                    new DatagramPacket(responseData.packetData, responseData.packetData.length);
+            MdnsPacketReader reader = new MdnsPacketReader(packet);
+            String[] name = reader.readLabels();
+            reader.skip(2); // skip record type indication.
+            // Apply the right kind of record to the response.
+            if (responseData.recordClass == MdnsInet4AddressRecord.class) {
+                response.setInet4AddressRecord(new MdnsInet4AddressRecord(name, reader));
+            } else if (responseData.recordClass == MdnsInet6AddressRecord.class) {
+                response.setInet6AddressRecord(new MdnsInet6AddressRecord(name, reader));
+            } else if (responseData.recordClass == MdnsPointerRecord.class) {
+                response.addPointerRecord(new MdnsPointerRecord(name, reader));
+            } else if (responseData.recordClass == MdnsServiceRecord.class) {
+                response.setServiceRecord(new MdnsServiceRecord(name, reader));
+            } else if (responseData.recordClass == MdnsTextRecord.class) {
+                response.setTextRecord(new MdnsTextRecord(name, reader));
+            } else {
+                fail("Unsupported/unexpected MdnsRecord subtype used in test - invalid test!");
+            }
+        }
+        return response;
+    }
+
+    @Test
+    public void getInet4AddressRecord_returnsAddedRecord() throws IOException {
+        DatagramPacket packet = new DatagramPacket(dataIn_ipv4_1, dataIn_ipv4_1.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+        String[] name = reader.readLabels();
+        reader.skip(2); // skip record type indication.
+        MdnsInetAddressRecord record = new MdnsInetAddressRecord(name, MdnsRecord.TYPE_A, reader);
+        MdnsResponse response = new MdnsResponse(0);
+        assertFalse(response.hasInet4AddressRecord());
+        assertTrue(response.setInet4AddressRecord(record));
+        assertEquals(response.getInet4AddressRecord(), record);
+    }
+
+    @Test
+    public void getInet6AddressRecord_returnsAddedRecord() throws IOException {
+        DatagramPacket packet = new DatagramPacket(dataIn_ipv6_1, dataIn_ipv6_1.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+        String[] name = reader.readLabels();
+        reader.skip(2); // skip record type indication.
+        MdnsInetAddressRecord record =
+                new MdnsInetAddressRecord(name, MdnsRecord.TYPE_AAAA, reader);
+        MdnsResponse response = new MdnsResponse(0);
+        assertFalse(response.hasInet6AddressRecord());
+        assertTrue(response.setInet6AddressRecord(record));
+        assertEquals(response.getInet6AddressRecord(), record);
+    }
+
+    @Test
+    public void getPointerRecords_returnsAddedRecord() throws IOException {
+        DatagramPacket packet = new DatagramPacket(dataIn_ptr_1, dataIn_ptr_1.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+        String[] name = reader.readLabels();
+        reader.skip(2); // skip record type indication.
+        MdnsPointerRecord record = new MdnsPointerRecord(name, reader);
+        MdnsResponse response = new MdnsResponse(0);
+        assertFalse(response.hasPointerRecords());
+        assertTrue(response.addPointerRecord(record));
+        List<MdnsPointerRecord> recordList = response.getPointerRecords();
+        assertNotNull(recordList);
+        assertEquals(1, recordList.size());
+        assertEquals(record, recordList.get(0));
+    }
+
+    @Test
+    public void getServiceRecord_returnsAddedRecord() throws IOException {
+        DatagramPacket packet = new DatagramPacket(dataIn_service_1, dataIn_service_1.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+        String[] name = reader.readLabels();
+        reader.skip(2); // skip record type indication.
+        MdnsServiceRecord record = new MdnsServiceRecord(name, reader);
+        MdnsResponse response = new MdnsResponse(0);
+        assertFalse(response.hasServiceRecord());
+        assertTrue(response.setServiceRecord(record));
+        assertEquals(response.getServiceRecord(), record);
+    }
+
+    @Test
+    public void getTextRecord_returnsAddedRecord() throws IOException {
+        DatagramPacket packet = new DatagramPacket(dataIn_text_1, dataIn_text_1.length);
+        MdnsPacketReader reader = new MdnsPacketReader(packet);
+        String[] name = reader.readLabels();
+        reader.skip(2); // skip record type indication.
+        MdnsTextRecord record = new MdnsTextRecord(name, reader);
+        MdnsResponse response = new MdnsResponse(0);
+        assertFalse(response.hasTextRecord());
+        assertTrue(response.setTextRecord(record));
+        assertEquals(response.getTextRecord(), record);
+    }
+
+    @Test
+    public void mergeRecordsFrom_indicates_change_on_ipv4_address() throws IOException {
+        MdnsResponse response = makeMdnsResponse(
+                0,
+                Arrays.asList(
+                        new PacketAndRecordClass(dataIn_ipv4_1, MdnsInet4AddressRecord.class)));
+        // Now create a new response that updates the address.
+        MdnsResponse response2 = makeMdnsResponse(
+                100,
+                Arrays.asList(
+                        new PacketAndRecordClass(dataIn_ipv4_2, MdnsInet4AddressRecord.class)));
+        assertTrue(response.mergeRecordsFrom(response2));
+    }
+
+    @Test
+    public void mergeRecordsFrom_indicates_change_on_ipv6_address() throws IOException {
+        MdnsResponse response = makeMdnsResponse(
+                0,
+                Arrays.asList(
+                        new PacketAndRecordClass(dataIn_ipv6_1, MdnsInet6AddressRecord.class)));
+        // Now create a new response that updates the address.
+        MdnsResponse response2 = makeMdnsResponse(
+                100,
+                Arrays.asList(
+                        new PacketAndRecordClass(dataIn_ipv6_2, MdnsInet6AddressRecord.class)));
+        assertTrue(response.mergeRecordsFrom(response2));
+    }
+
+    @Test
+    public void mergeRecordsFrom_indicates_change_on_text() throws IOException {
+        MdnsResponse response = makeMdnsResponse(
+                0,
+                Arrays.asList(new PacketAndRecordClass(dataIn_text_1, MdnsTextRecord.class)));
+        // Now create a new response that updates the address.
+        MdnsResponse response2 = makeMdnsResponse(
+                100,
+                Arrays.asList(new PacketAndRecordClass(dataIn_text_2, MdnsTextRecord.class)));
+        assertTrue(response.mergeRecordsFrom(response2));
+    }
+
+    @Test
+    public void mergeRecordsFrom_indicates_change_on_service() throws IOException {
+        MdnsResponse response = makeMdnsResponse(
+                0,
+                Arrays.asList(new PacketAndRecordClass(dataIn_service_1, MdnsServiceRecord.class)));
+        // Now create a new response that updates the address.
+        MdnsResponse response2 = makeMdnsResponse(
+                100,
+                Arrays.asList(new PacketAndRecordClass(dataIn_service_2, MdnsServiceRecord.class)));
+        assertTrue(response.mergeRecordsFrom(response2));
+    }
+
+    @Test
+    public void mergeRecordsFrom_indicates_change_on_pointer() throws IOException {
+        MdnsResponse response = makeMdnsResponse(
+                0,
+                Arrays.asList(new PacketAndRecordClass(dataIn_ptr_1, MdnsPointerRecord.class)));
+        // Now create a new response that updates the address.
+        MdnsResponse response2 = makeMdnsResponse(
+                100,
+                Arrays.asList(new PacketAndRecordClass(dataIn_ptr_2, MdnsPointerRecord.class)));
+        assertTrue(response.mergeRecordsFrom(response2));
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void mergeRecordsFrom_indicates_noChange() throws IOException {
+        //MdnsConfigsFlagsImpl.useReducedMergeRecordUpdateEvents.override(true);
+        List<PacketAndRecordClass> recordList =
+                Arrays.asList(
+                        new PacketAndRecordClass(dataIn_ipv4_1, MdnsInet4AddressRecord.class),
+                        new PacketAndRecordClass(dataIn_ipv6_1, MdnsInet6AddressRecord.class),
+                        new PacketAndRecordClass(dataIn_ptr_1, MdnsPointerRecord.class),
+                        new PacketAndRecordClass(dataIn_service_2, MdnsServiceRecord.class),
+                        new PacketAndRecordClass(dataIn_text_1, MdnsTextRecord.class));
+        // Create a two identical responses.
+        MdnsResponse response = makeMdnsResponse(0, recordList);
+        MdnsResponse response2 = makeMdnsResponse(100, recordList);
+        // Merging should not indicate any change.
+        assertFalse(response.mergeRecordsFrom(response2));
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
new file mode 100644
index 0000000..5843fd0
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
@@ -0,0 +1,770 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.annotation.NonNull;
+
+import com.android.server.connectivity.mdns.MdnsServiceTypeClient.QueryTaskConfig;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.SocketAddress;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+/** Tests for {@link MdnsServiceTypeClient}. */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsServiceTypeClientTests {
+
+    private static final String SERVICE_TYPE = "_googlecast._tcp.local";
+
+    @Mock
+    private MdnsServiceBrowserListener mockListenerOne;
+    @Mock
+    private MdnsServiceBrowserListener mockListenerTwo;
+    @Mock
+    private MdnsPacketWriter mockPacketWriter;
+    @Mock
+    private MdnsSocketClient mockSocketClient;
+    @Captor
+    private ArgumentCaptor<MdnsServiceInfo> serviceInfoCaptor;
+
+    private final byte[] buf = new byte[10];
+
+    private DatagramPacket[] expectedPackets;
+    private ScheduledFuture<?>[] expectedSendFutures;
+    private FakeExecutor currentThreadExecutor = new FakeExecutor();
+
+    private MdnsServiceTypeClient client;
+
+    @Before
+    @SuppressWarnings("DoNotMock")
+    public void setUp() throws IOException {
+        MockitoAnnotations.initMocks(this);
+
+        expectedPackets = new DatagramPacket[16];
+        expectedSendFutures = new ScheduledFuture<?>[16];
+
+        for (int i = 0; i < expectedSendFutures.length; ++i) {
+            expectedPackets[i] = new DatagramPacket(buf, 0, 5);
+            expectedSendFutures[i] = Mockito.mock(ScheduledFuture.class);
+        }
+        when(mockPacketWriter.getPacket(any(SocketAddress.class)))
+                .thenReturn(expectedPackets[0])
+                .thenReturn(expectedPackets[1])
+                .thenReturn(expectedPackets[2])
+                .thenReturn(expectedPackets[3])
+                .thenReturn(expectedPackets[4])
+                .thenReturn(expectedPackets[5])
+                .thenReturn(expectedPackets[6])
+                .thenReturn(expectedPackets[7])
+                .thenReturn(expectedPackets[8])
+                .thenReturn(expectedPackets[9])
+                .thenReturn(expectedPackets[10])
+                .thenReturn(expectedPackets[11])
+                .thenReturn(expectedPackets[12])
+                .thenReturn(expectedPackets[13])
+                .thenReturn(expectedPackets[14])
+                .thenReturn(expectedPackets[15]);
+
+        client =
+                new MdnsServiceTypeClient(SERVICE_TYPE, mockSocketClient, currentThreadExecutor) {
+                    @Override
+                    MdnsPacketWriter createMdnsPacketWriter() {
+                        return mockPacketWriter;
+                    }
+                };
+    }
+
+    @Test
+    public void sendQueries_activeScanMode() {
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(false).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+
+        // First burst, 3 queries.
+        verifyAndSendQuery(0, 0, /* expectsUnicastResponse= */ true);
+        verifyAndSendQuery(
+                1, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                2, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        // Second burst will be sent after initialTimeBetweenBurstsMs, 3 queries.
+        verifyAndSendQuery(
+                3, MdnsConfigs.initialTimeBetweenBurstsMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                4, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                5, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        // Third burst will be sent after initialTimeBetweenBurstsMs * 2, 3 queries.
+        verifyAndSendQuery(
+                6, MdnsConfigs.initialTimeBetweenBurstsMs() * 2, /* expectsUnicastResponse= */
+                false);
+        verifyAndSendQuery(
+                7, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                8, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        // Forth burst will be sent after initialTimeBetweenBurstsMs * 4, 3 queries.
+        verifyAndSendQuery(
+                9, MdnsConfigs.initialTimeBetweenBurstsMs() * 4, /* expectsUnicastResponse= */
+                false);
+        verifyAndSendQuery(
+                10, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                11, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        // Fifth burst will be sent after timeBetweenBurstsMs, 3 queries.
+        verifyAndSendQuery(12, MdnsConfigs.timeBetweenBurstsMs(), /* expectsUnicastResponse= */
+                false);
+        verifyAndSendQuery(
+                13, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                14, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+
+        // Stop sending packets.
+        client.stopSendAndReceive(mockListenerOne);
+        verify(expectedSendFutures[15]).cancel(true);
+    }
+
+    @Test
+    public void sendQueries_reentry_activeScanMode() {
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(false).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+
+        // First burst, first query is sent.
+        verifyAndSendQuery(0, 0, /* expectsUnicastResponse= */ true);
+
+        // After the first query is sent, change the subtypes, and restart.
+        searchOptions =
+                MdnsSearchOptions.newBuilder()
+                        .addSubtype("12345")
+                        .addSubtype("abcde")
+                        .setIsPassiveMode(false)
+                        .build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+        // The previous scheduled task should be canceled.
+        verify(expectedSendFutures[1]).cancel(true);
+
+        // Queries should continue to be sent.
+        verifyAndSendQuery(1, 0, /* expectsUnicastResponse= */ true);
+        verifyAndSendQuery(
+                2, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                3, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+
+        // Stop sending packets.
+        client.stopSendAndReceive(mockListenerOne);
+        verify(expectedSendFutures[5]).cancel(true);
+    }
+
+    @Test
+    public void sendQueries_passiveScanMode() {
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(true).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+
+        // First burst, 3 query.
+        verifyAndSendQuery(0, 0, /* expectsUnicastResponse= */ true);
+        verifyAndSendQuery(
+                1, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                2, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        // Second burst will be sent after timeBetweenBurstsMs, 1 query.
+        verifyAndSendQuery(3, MdnsConfigs.timeBetweenBurstsMs(), /* expectsUnicastResponse= */
+                false);
+        // Third burst will be sent after timeBetweenBurstsMs, 1 query.
+        verifyAndSendQuery(4, MdnsConfigs.timeBetweenBurstsMs(), /* expectsUnicastResponse= */
+                false);
+
+        // Stop sending packets.
+        client.stopSendAndReceive(mockListenerOne);
+        verify(expectedSendFutures[5]).cancel(true);
+    }
+
+    @Test
+    public void sendQueries_reentry_passiveScanMode() {
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(true).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+
+        // First burst, first query is sent.
+        verifyAndSendQuery(0, 0, /* expectsUnicastResponse= */ true);
+
+        // After the first query is sent, change the subtypes, and restart.
+        searchOptions =
+                MdnsSearchOptions.newBuilder()
+                        .addSubtype("12345")
+                        .addSubtype("abcde")
+                        .setIsPassiveMode(true)
+                        .build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+        // The previous scheduled task should be canceled.
+        verify(expectedSendFutures[1]).cancel(true);
+
+        // Queries should continue to be sent.
+        verifyAndSendQuery(1, 0, /* expectsUnicastResponse= */ true);
+        verifyAndSendQuery(
+                2, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+        verifyAndSendQuery(
+                3, MdnsConfigs.timeBetweenQueriesInBurstMs(), /* expectsUnicastResponse= */ false);
+
+        // Stop sending packets.
+        client.stopSendAndReceive(mockListenerOne);
+        verify(expectedSendFutures[5]).cancel(true);
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testQueryTaskConfig_alwaysAskForUnicastResponse() {
+        //MdnsConfigsFlagsImpl.alwaysAskForUnicastResponseInEachBurst.override(true);
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(false).build();
+        QueryTaskConfig config =
+                new QueryTaskConfig(searchOptions.getSubtypes(), searchOptions.isPassiveMode(), 1);
+
+        // This is the first query. We will ask for unicast response.
+        assertTrue(config.expectUnicastResponse);
+        assertEquals(config.subtypes, searchOptions.getSubtypes());
+        assertEquals(config.transactionId, 1);
+
+        // For the rest of queries in this burst, we will NOT ask for unicast response.
+        for (int i = 1; i < MdnsConfigs.queriesPerBurst(); i++) {
+            int oldTransactionId = config.transactionId;
+            config = config.getConfigForNextRun();
+            assertFalse(config.expectUnicastResponse);
+            assertEquals(config.subtypes, searchOptions.getSubtypes());
+            assertEquals(config.transactionId, oldTransactionId + 1);
+        }
+
+        // This is the first query of a new burst. We will ask for unicast response.
+        int oldTransactionId = config.transactionId;
+        config = config.getConfigForNextRun();
+        assertTrue(config.expectUnicastResponse);
+        assertEquals(config.subtypes, searchOptions.getSubtypes());
+        assertEquals(config.transactionId, oldTransactionId + 1);
+    }
+
+    @Test
+    public void testQueryTaskConfig_askForUnicastInFirstQuery() {
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(false).build();
+        QueryTaskConfig config =
+                new QueryTaskConfig(searchOptions.getSubtypes(), searchOptions.isPassiveMode(), 1);
+
+        // This is the first query. We will ask for unicast response.
+        assertTrue(config.expectUnicastResponse);
+        assertEquals(config.subtypes, searchOptions.getSubtypes());
+        assertEquals(config.transactionId, 1);
+
+        // For the rest of queries in this burst, we will NOT ask for unicast response.
+        for (int i = 1; i < MdnsConfigs.queriesPerBurst(); i++) {
+            int oldTransactionId = config.transactionId;
+            config = config.getConfigForNextRun();
+            assertFalse(config.expectUnicastResponse);
+            assertEquals(config.subtypes, searchOptions.getSubtypes());
+            assertEquals(config.transactionId, oldTransactionId + 1);
+        }
+
+        // This is the first query of a new burst. We will NOT ask for unicast response.
+        int oldTransactionId = config.transactionId;
+        config = config.getConfigForNextRun();
+        assertFalse(config.expectUnicastResponse);
+        assertEquals(config.subtypes, searchOptions.getSubtypes());
+        assertEquals(config.transactionId, oldTransactionId + 1);
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testIfPreviousTaskIsCanceledWhenNewSessionStarts() {
+        //MdnsConfigsFlagsImpl.useSessionIdToScheduleMdnsTask.override(true);
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(true).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+        Runnable firstMdnsTask = currentThreadExecutor.getAndClearSubmittedRunnable();
+
+        // Change the sutypes and start a new session.
+        searchOptions =
+                MdnsSearchOptions.newBuilder()
+                        .addSubtype("12345")
+                        .addSubtype("abcde")
+                        .setIsPassiveMode(true)
+                        .build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the first mdns task is not successful canceled and it gets
+        // executed anyway.
+        firstMdnsTask.run();
+
+        // Although it gets executes, no more task gets scheduled.
+        assertNull(currentThreadExecutor.getAndClearLastScheduledRunnable());
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testIfPreviousTaskIsCanceledWhenSessionStops() {
+        //MdnsConfigsFlagsImpl.shouldCancelScanTaskWhenFutureIsNull.override(true);
+        MdnsSearchOptions searchOptions =
+                MdnsSearchOptions.newBuilder().addSubtype("12345").setIsPassiveMode(true).build();
+        client.startSendAndReceive(mockListenerOne, searchOptions);
+        // Change the sutypes and start a new session.
+        client.stopSendAndReceive(mockListenerOne);
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the first mdns task is not successful canceled and it gets
+        // executed anyway.
+        currentThreadExecutor.getAndClearSubmittedRunnable().run();
+
+        // Although it gets executes, no more task gets scheduled.
+        assertNull(currentThreadExecutor.getAndClearLastScheduledRunnable());
+    }
+
+    @Test
+    public void processResponse_incompleteResponse() {
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        MdnsResponse response = mock(MdnsResponse.class);
+        when(response.getServiceInstanceName()).thenReturn("service-instance-1");
+        when(response.isComplete()).thenReturn(false);
+
+        client.processResponse(response);
+
+        verify(mockListenerOne, never()).onServiceFound(any(MdnsServiceInfo.class));
+        verify(mockListenerOne, never()).onServiceUpdated(any(MdnsServiceInfo.class));
+    }
+
+    @Test
+    public void processIPv4Response_completeResponseForNewServiceInstance() throws Exception {
+        final String ipV4Address = "192.168.1.1";
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        "service-instance-1",
+                        ipV4Address,
+                        5353,
+                        Collections.singletonList("ABCDE"),
+                        Collections.emptyMap());
+        client.processResponse(initialResponse);
+
+        // Process a second response with a different port and updated text attributes.
+        MdnsResponse secondResponse =
+                createResponse(
+                        "service-instance-1",
+                        ipV4Address,
+                        5354,
+                        Collections.singletonList("ABCDE"),
+                        Collections.singletonMap("key", "value"));
+        client.processResponse(secondResponse);
+
+        // Verify onServiceFound was called once for the initial response.
+        verify(mockListenerOne).onServiceFound(serviceInfoCaptor.capture());
+        MdnsServiceInfo initialServiceInfo = serviceInfoCaptor.getAllValues().get(0);
+        assertEquals(initialServiceInfo.getServiceInstanceName(), "service-instance-1");
+        assertEquals(initialServiceInfo.getIpv4Address(), ipV4Address);
+        assertEquals(initialServiceInfo.getPort(), 5353);
+        assertEquals(initialServiceInfo.getSubtypes(), Collections.singletonList("ABCDE"));
+        assertNull(initialServiceInfo.getAttributeByKey("key"));
+
+        // Verify onServiceUpdated was called once for the second response.
+        verify(mockListenerOne).onServiceUpdated(serviceInfoCaptor.capture());
+        MdnsServiceInfo updatedServiceInfo = serviceInfoCaptor.getAllValues().get(1);
+        assertEquals(updatedServiceInfo.getServiceInstanceName(), "service-instance-1");
+        assertEquals(updatedServiceInfo.getIpv4Address(), ipV4Address);
+        assertEquals(updatedServiceInfo.getPort(), 5354);
+        assertTrue(updatedServiceInfo.hasSubtypes());
+        assertEquals(updatedServiceInfo.getSubtypes(), Collections.singletonList("ABCDE"));
+        assertEquals(updatedServiceInfo.getAttributeByKey("key"), "value");
+    }
+
+    @Test
+    public void processIPv6Response_getCorrectServiceInfo() throws Exception {
+        final String ipV6Address = "2000:3333::da6c:63ff:fe7c:7483";
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        "service-instance-1",
+                        ipV6Address,
+                        5353,
+                        Collections.singletonList("ABCDE"),
+                        Collections.emptyMap());
+        client.processResponse(initialResponse);
+
+        // Process a second response with a different port and updated text attributes.
+        MdnsResponse secondResponse =
+                createResponse(
+                        "service-instance-1",
+                        ipV6Address,
+                        5354,
+                        Collections.singletonList("ABCDE"),
+                        Collections.singletonMap("key", "value"));
+        client.processResponse(secondResponse);
+
+        System.out.println("secondResponses ip"
+                + secondResponse.getInet6AddressRecord().getInet6Address().getHostAddress());
+
+        // Verify onServiceFound was called once for the initial response.
+        verify(mockListenerOne).onServiceFound(serviceInfoCaptor.capture());
+        MdnsServiceInfo initialServiceInfo = serviceInfoCaptor.getAllValues().get(0);
+        assertEquals(initialServiceInfo.getServiceInstanceName(), "service-instance-1");
+        assertEquals(initialServiceInfo.getIpv6Address(), ipV6Address);
+        assertEquals(initialServiceInfo.getPort(), 5353);
+        assertEquals(initialServiceInfo.getSubtypes(), Collections.singletonList("ABCDE"));
+        assertNull(initialServiceInfo.getAttributeByKey("key"));
+
+        // Verify onServiceUpdated was called once for the second response.
+        verify(mockListenerOne).onServiceUpdated(serviceInfoCaptor.capture());
+        MdnsServiceInfo updatedServiceInfo = serviceInfoCaptor.getAllValues().get(1);
+        assertEquals(updatedServiceInfo.getServiceInstanceName(), "service-instance-1");
+        assertEquals(updatedServiceInfo.getIpv6Address(), ipV6Address);
+        assertEquals(updatedServiceInfo.getPort(), 5354);
+        assertTrue(updatedServiceInfo.hasSubtypes());
+        assertEquals(updatedServiceInfo.getSubtypes(), Collections.singletonList("ABCDE"));
+        assertEquals(updatedServiceInfo.getAttributeByKey("key"), "value");
+    }
+
+    @Test
+    public void processResponse_goodBye() {
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        client.startSendAndReceive(mockListenerTwo, MdnsSearchOptions.getDefaultOptions());
+
+        MdnsResponse response = mock(MdnsResponse.class);
+        when(response.getServiceInstanceName()).thenReturn("goodbye-service-instance-name");
+        when(response.isGoodbye()).thenReturn(true);
+        client.processResponse(response);
+
+        verify(mockListenerOne).onServiceRemoved("goodbye-service-instance-name");
+        verify(mockListenerTwo).onServiceRemoved("goodbye-service-instance-name");
+    }
+
+    @Test
+    public void reportExistingServiceToNewlyRegisteredListeners() throws UnknownHostException {
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        "service-instance-1",
+                        "192.168.1.1",
+                        5353,
+                        Collections.singletonList("ABCDE"),
+                        Collections.emptyMap());
+        client.processResponse(initialResponse);
+
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+
+        // Verify onServiceFound was called once for the existing response.
+        verify(mockListenerOne).onServiceFound(serviceInfoCaptor.capture());
+        MdnsServiceInfo existingServiceInfo = serviceInfoCaptor.getAllValues().get(0);
+        assertEquals(existingServiceInfo.getServiceInstanceName(), "service-instance-1");
+        assertEquals(existingServiceInfo.getIpv4Address(), "192.168.1.1");
+        assertEquals(existingServiceInfo.getPort(), 5353);
+        assertEquals(existingServiceInfo.getSubtypes(), Collections.singletonList("ABCDE"));
+        assertNull(existingServiceInfo.getAttributeByKey("key"));
+
+        // Process a goodbye message for the existing response.
+        MdnsResponse goodByeResponse = mock(MdnsResponse.class);
+        when(goodByeResponse.getServiceInstanceName()).thenReturn("service-instance-1");
+        when(goodByeResponse.isGoodbye()).thenReturn(true);
+        client.processResponse(goodByeResponse);
+
+        client.startSendAndReceive(mockListenerTwo, MdnsSearchOptions.getDefaultOptions());
+
+        // Verify onServiceFound was not called on the newly registered listener after the existing
+        // response is gone.
+        verify(mockListenerTwo, never()).onServiceFound(any(MdnsServiceInfo.class));
+    }
+
+    @Test
+    public void processResponse_notAllowRemoveSearch_shouldNotRemove() throws Exception {
+        final String serviceInstanceName = "service-instance-1";
+        client.startSendAndReceive(
+                mockListenerOne,
+                MdnsSearchOptions.newBuilder().build());
+        Runnable firstMdnsTask = currentThreadExecutor.getAndClearSubmittedRunnable();
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        serviceInstanceName, "192.168.1.1", 5353, List.of("ABCDE"),
+                        Map.of());
+        client.processResponse(initialResponse);
+
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the response is after TTL.
+        when(initialResponse.getServiceRecord().getRemainingTTL(anyLong())).thenReturn((long) 0);
+        firstMdnsTask.run();
+
+        // Verify onServiceRemoved was not called.
+        verify(mockListenerOne, never()).onServiceRemoved(serviceInstanceName);
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void processResponse_allowSearchOptionsToRemoveExpiredService_shouldRemove()
+            throws Exception {
+        //MdnsConfigsFlagsImpl.allowSearchOptionsToRemoveExpiredService.override(true);
+        final String serviceInstanceName = "service-instance-1";
+        client =
+                new MdnsServiceTypeClient(SERVICE_TYPE, mockSocketClient, currentThreadExecutor) {
+                    @Override
+                    MdnsPacketWriter createMdnsPacketWriter() {
+                        return mockPacketWriter;
+                    }
+                };
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        Runnable firstMdnsTask = currentThreadExecutor.getAndClearSubmittedRunnable();
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        serviceInstanceName, "192.168.1.1", 5353, List.of("ABCDE"),
+                        Map.of());
+        client.processResponse(initialResponse);
+
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the response is under TTL.
+        when(initialResponse.getServiceRecord().getRemainingTTL(anyLong())).thenReturn((long) 1000);
+        firstMdnsTask.run();
+
+        // Verify onServiceRemoved was not called.
+        verify(mockListenerOne, never()).onServiceRemoved(serviceInstanceName);
+
+        // Simulate the case where the response is after TTL.
+        when(initialResponse.getServiceRecord().getRemainingTTL(anyLong())).thenReturn((long) 0);
+        firstMdnsTask.run();
+
+        // Verify onServiceRemoved was called.
+        verify(mockListenerOne, times(1)).onServiceRemoved(serviceInstanceName);
+    }
+
+    @Test
+    public void processResponse_searchOptionsNotEnableServiceRemoval_shouldNotRemove()
+            throws Exception {
+        final String serviceInstanceName = "service-instance-1";
+        client =
+                new MdnsServiceTypeClient(SERVICE_TYPE, mockSocketClient, currentThreadExecutor) {
+                    @Override
+                    MdnsPacketWriter createMdnsPacketWriter() {
+                        return mockPacketWriter;
+                    }
+                };
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        Runnable firstMdnsTask = currentThreadExecutor.getAndClearSubmittedRunnable();
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        serviceInstanceName, "192.168.1.1", 5353, List.of("ABCDE"),
+                        Map.of());
+        client.processResponse(initialResponse);
+
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the response is after TTL.
+        when(initialResponse.getServiceRecord().getRemainingTTL(anyLong())).thenReturn((long) 0);
+        firstMdnsTask.run();
+
+        // Verify onServiceRemoved was not called.
+        verify(mockListenerOne, never()).onServiceRemoved(serviceInstanceName);
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void processResponse_removeServiceAfterTtlExpiresEnabled_shouldRemove()
+            throws Exception {
+        //MdnsConfigsFlagsImpl.removeServiceAfterTtlExpires.override(true);
+        final String serviceInstanceName = "service-instance-1";
+        client =
+                new MdnsServiceTypeClient(SERVICE_TYPE, mockSocketClient, currentThreadExecutor) {
+                    @Override
+                    MdnsPacketWriter createMdnsPacketWriter() {
+                        return mockPacketWriter;
+                    }
+                };
+        client.startSendAndReceive(mockListenerOne, MdnsSearchOptions.getDefaultOptions());
+        Runnable firstMdnsTask = currentThreadExecutor.getAndClearSubmittedRunnable();
+
+        // Process the initial response.
+        MdnsResponse initialResponse =
+                createResponse(
+                        serviceInstanceName, "192.168.1.1", 5353, List.of("ABCDE"),
+                        Map.of());
+        client.processResponse(initialResponse);
+
+        // Clear the scheduled runnable.
+        currentThreadExecutor.getAndClearLastScheduledRunnable();
+
+        // Simulate the case where the response is after TTL.
+        when(initialResponse.getServiceRecord().getRemainingTTL(anyLong())).thenReturn((long) 0);
+        firstMdnsTask.run();
+
+        // Verify onServiceRemoved was not called.
+        verify(mockListenerOne, times(1)).onServiceRemoved(serviceInstanceName);
+    }
+
+    // verifies that the right query was enqueued with the right delay, and send query by executing
+    // the runnable.
+    private void verifyAndSendQuery(int index, long timeInMs, boolean expectsUnicastResponse) {
+        assertEquals(currentThreadExecutor.getAndClearLastScheduledDelayInMs(), timeInMs);
+        currentThreadExecutor.getAndClearLastScheduledRunnable().run();
+        if (expectsUnicastResponse) {
+            verify(mockSocketClient).sendUnicastPacket(expectedPackets[index]);
+        } else {
+            verify(mockSocketClient).sendMulticastPacket(expectedPackets[index]);
+        }
+    }
+
+    // A fake ScheduledExecutorService that keeps tracking the last scheduled Runnable and its delay
+    // time.
+    private class FakeExecutor extends ScheduledThreadPoolExecutor {
+        private long lastScheduledDelayInMs;
+        private Runnable lastScheduledRunnable;
+        private Runnable lastSubmittedRunnable;
+        private int futureIndex;
+
+        FakeExecutor() {
+            super(1);
+            lastScheduledDelayInMs = -1;
+        }
+
+        @Override
+        public Future<?> submit(Runnable command) {
+            Future<?> future = super.submit(command);
+            lastSubmittedRunnable = command;
+            return future;
+        }
+
+        // Don't call through the real implementation, just track the scheduled Runnable, and
+        // returns a ScheduledFuture.
+        @Override
+        public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
+            lastScheduledDelayInMs = delay;
+            lastScheduledRunnable = command;
+            return expectedSendFutures[futureIndex++];
+        }
+
+        // Returns the delay of the last scheduled task, and clear it.
+        long getAndClearLastScheduledDelayInMs() {
+            long val = lastScheduledDelayInMs;
+            lastScheduledDelayInMs = -1;
+            return val;
+        }
+
+        // Returns the last scheduled task, and clear it.
+        Runnable getAndClearLastScheduledRunnable() {
+            Runnable val = lastScheduledRunnable;
+            lastScheduledRunnable = null;
+            return val;
+        }
+
+        Runnable getAndClearSubmittedRunnable() {
+            Runnable val = lastSubmittedRunnable;
+            lastSubmittedRunnable = null;
+            return val;
+        }
+    }
+
+    // Creates a complete mDNS response.
+    private MdnsResponse createResponse(
+            @NonNull String serviceInstanceName,
+            @NonNull String host,
+            int port,
+            @NonNull List<String> subtypes,
+            @NonNull Map<String, String> textAttributes)
+            throws UnknownHostException {
+        String[] hostName = new String[]{"hostname"};
+        MdnsServiceRecord serviceRecord = mock(MdnsServiceRecord.class);
+        when(serviceRecord.getServiceHost()).thenReturn(hostName);
+        when(serviceRecord.getServicePort()).thenReturn(port);
+
+        MdnsResponse response = spy(new MdnsResponse(0));
+
+        MdnsInetAddressRecord inetAddressRecord = mock(MdnsInetAddressRecord.class);
+        if (host.contains(":")) {
+            when(inetAddressRecord.getInet6Address())
+                    .thenReturn((Inet6Address) Inet6Address.getByName(host));
+            response.setInet6AddressRecord(inetAddressRecord);
+        } else {
+            when(inetAddressRecord.getInet4Address())
+                    .thenReturn((Inet4Address) Inet4Address.getByName(host));
+            response.setInet4AddressRecord(inetAddressRecord);
+        }
+
+        MdnsTextRecord textRecord = mock(MdnsTextRecord.class);
+        List<String> textStrings = new ArrayList<>();
+        for (Map.Entry<String, String> kv : textAttributes.entrySet()) {
+            textStrings.add(kv.getKey() + "=" + kv.getValue());
+        }
+        when(textRecord.getStrings()).thenReturn(textStrings);
+
+        response.setServiceRecord(serviceRecord);
+        response.setTextRecord(textRecord);
+
+        doReturn(false).when(response).isGoodbye();
+        doReturn(true).when(response).isComplete();
+        doReturn(serviceInstanceName).when(response).getServiceInstanceName();
+        doReturn(new ArrayList<>(subtypes)).when(response).getSubtypes();
+        return response;
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketClientTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketClientTests.java
new file mode 100644
index 0000000..21ed7eb
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketClientTests.java
@@ -0,0 +1,493 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.Manifest.permission;
+import android.annotation.RequiresPermission;
+import android.content.Context;
+import android.net.wifi.WifiManager;
+import android.net.wifi.WifiManager.MulticastLock;
+import android.text.format.DateUtils;
+
+import com.android.net.module.util.HexDump;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentMatchers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.mockito.invocation.InvocationOnMock;
+
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/** Tests for {@link MdnsSocketClient} */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsSocketClientTests {
+    private static final long TIMEOUT = 500;
+    private final byte[] buf = new byte[10];
+    final AtomicBoolean enableMulticastResponse = new AtomicBoolean(true);
+    final AtomicBoolean enableUnicastResponse = new AtomicBoolean(true);
+
+    @Mock private Context mContext;
+    @Mock private WifiManager mockWifiManager;
+    @Mock private MdnsSocket mockMulticastSocket;
+    @Mock private MdnsSocket mockUnicastSocket;
+    @Mock private MulticastLock mockMulticastLock;
+    @Mock private MdnsSocketClient.Callback mockCallback;
+
+    private MdnsSocketClient mdnsClient;
+
+    @Before
+    public void setup() throws RuntimeException, IOException {
+        MockitoAnnotations.initMocks(this);
+
+        when(mockWifiManager.createMulticastLock(ArgumentMatchers.anyString()))
+                .thenReturn(mockMulticastLock);
+
+        mdnsClient = new MdnsSocketClient(mContext, mockMulticastLock) {
+                    @Override
+                    MdnsSocket createMdnsSocket(int port) throws IOException {
+                        if (port == MdnsConstants.MDNS_PORT) {
+                            return mockMulticastSocket;
+                        }
+                        return mockUnicastSocket;
+                    }
+                };
+        mdnsClient.setCallback(mockCallback);
+
+        doAnswer(
+                (InvocationOnMock invocationOnMock) -> {
+                    final byte[] dataIn = HexDump.hexStringToByteArray(
+                            "0000840000000004"
+                            + "00000003134A6F68"
+                            + "6E6E792773204368"
+                            + "726F6D6563617374"
+                            + "0B5F676F6F676C65"
+                            + "63617374045F7463"
+                            + "70056C6F63616C00"
+                            + "0010800100001194"
+                            + "006C2369643D3937"
+                            + "3062663534376237"
+                            + "3533666336336332"
+                            + "6432613336626238"
+                            + "3936616261380576"
+                            + "653D30320D6D643D"
+                            + "4368726F6D656361"
+                            + "73741269633D2F73"
+                            + "657475702F69636F"
+                            + "6E2E706E6716666E"
+                            + "3D4A6F686E6E7927"
+                            + "73204368726F6D65"
+                            + "636173740463613D"
+                            + "350473743D30095F"
+                            + "7365727669636573"
+                            + "075F646E732D7364"
+                            + "045F756470C03100"
+                            + "0C00010000119400"
+                            + "02C020C020000C00"
+                            + "01000011940002C0"
+                            + "0CC00C0021800100"
+                            + "000078001C000000"
+                            + "001F49134A6F686E"
+                            + "6E79277320436872"
+                            + "6F6D6563617374C0"
+                            + "31C0F30001800100"
+                            + "0000780004C0A864"
+                            + "68C0F3002F800100"
+                            + "0000780005C0F300"
+                            + "0140C00C002F8001"
+                            + "000011940009C00C"
+                            + "00050000800040");
+                    if (enableMulticastResponse.get()) {
+                        DatagramPacket packet = invocationOnMock.getArgument(0);
+                        packet.setData(dataIn);
+                    }
+                    return null;
+                })
+                .when(mockMulticastSocket)
+                .receive(any(DatagramPacket.class));
+        doAnswer(
+                (InvocationOnMock invocationOnMock) -> {
+                    final byte[] dataIn = HexDump.hexStringToByteArray(
+                            "0000840000000004"
+                            + "00000003134A6F68"
+                            + "6E6E792773204368"
+                            + "726F6D6563617374"
+                            + "0B5F676F6F676C65"
+                            + "63617374045F7463"
+                            + "70056C6F63616C00"
+                            + "0010800100001194"
+                            + "006C2369643D3937"
+                            + "3062663534376237"
+                            + "3533666336336332"
+                            + "6432613336626238"
+                            + "3936616261380576"
+                            + "653D30320D6D643D"
+                            + "4368726F6D656361"
+                            + "73741269633D2F73"
+                            + "657475702F69636F"
+                            + "6E2E706E6716666E"
+                            + "3D4A6F686E6E7927"
+                            + "73204368726F6D65"
+                            + "636173740463613D"
+                            + "350473743D30095F"
+                            + "7365727669636573"
+                            + "075F646E732D7364"
+                            + "045F756470C03100"
+                            + "0C00010000119400"
+                            + "02C020C020000C00"
+                            + "01000011940002C0"
+                            + "0CC00C0021800100"
+                            + "000078001C000000"
+                            + "001F49134A6F686E"
+                            + "6E79277320436872"
+                            + "6F6D6563617374C0"
+                            + "31C0F30001800100"
+                            + "0000780004C0A864"
+                            + "68C0F3002F800100"
+                            + "0000780005C0F300"
+                            + "0140C00C002F8001"
+                            + "000011940009C00C"
+                            + "00050000800040");
+                    if (enableUnicastResponse.get()) {
+                        DatagramPacket packet = invocationOnMock.getArgument(0);
+                        packet.setData(dataIn);
+                    }
+                    return null;
+                })
+                .when(mockUnicastSocket)
+                .receive(any(DatagramPacket.class));
+    }
+
+    @After
+    public void tearDown() {
+        mdnsClient.stopDiscovery();
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testSendPackets_useSeparateSocketForUnicast()
+            throws InterruptedException, IOException {
+        //MdnsConfigsFlagsImpl.useSeparateSocketToSendUnicastQuery.override(true);
+        //MdnsConfigsFlagsImpl.checkMulticastResponse.override(true);
+        //MdnsConfigsFlagsImpl.checkMulticastResponseIntervalMs
+        //        .override(DateUtils.SECOND_IN_MILLIS);
+        mdnsClient.startDiscovery();
+        Thread multicastReceiverThread = mdnsClient.multicastReceiveThread;
+        Thread unicastReceiverThread = mdnsClient.unicastReceiveThread;
+        Thread sendThread = mdnsClient.sendThread;
+
+        assertTrue(multicastReceiverThread.isAlive());
+        assertTrue(sendThread.isAlive());
+        assertTrue(unicastReceiverThread.isAlive());
+
+        // Sends a packet.
+        DatagramPacket packet = new DatagramPacket(buf, 0, 5);
+        mdnsClient.sendMulticastPacket(packet);
+        // mockMulticastSocket.send() will be called on another thread. If we verify it immediately,
+        // it may not be called yet. So timeout is added.
+        verify(mockMulticastSocket, timeout(TIMEOUT).times(1)).send(packet);
+        verify(mockUnicastSocket, timeout(TIMEOUT).times(0)).send(packet);
+
+        // Verify the packet is sent by the unicast socket.
+        mdnsClient.sendUnicastPacket(packet);
+        verify(mockMulticastSocket, timeout(TIMEOUT).times(1)).send(packet);
+        verify(mockUnicastSocket, timeout(TIMEOUT).times(1)).send(packet);
+
+        // Stop the MdnsClient, and ensure that it stops in a reasonable amount of time.
+        // Run part of the test logic in a background thread, in case stopDiscovery() blocks
+        // for a long time (the foreground thread can fail the test early).
+        final CountDownLatch stopDiscoveryLatch = new CountDownLatch(1);
+        Thread testThread =
+                new Thread(
+                        new Runnable() {
+                            @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+                            @Override
+                            public void run() {
+                                mdnsClient.stopDiscovery();
+                                stopDiscoveryLatch.countDown();
+                            }
+                        });
+        testThread.start();
+        assertTrue(stopDiscoveryLatch.await(DateUtils.SECOND_IN_MILLIS, TimeUnit.MILLISECONDS));
+
+        // We should be able to join in a reasonable amount of time, to prove that the
+        // the MdnsClient exited without sending the large queue of packets.
+        testThread.join(DateUtils.SECOND_IN_MILLIS);
+
+        assertFalse(multicastReceiverThread.isAlive());
+        assertFalse(sendThread.isAlive());
+        assertFalse(unicastReceiverThread.isAlive());
+    }
+
+    @Test
+    public void testSendPackets_useSameSocketForMulticastAndUnicast()
+            throws InterruptedException, IOException {
+        mdnsClient.startDiscovery();
+        Thread multicastReceiverThread = mdnsClient.multicastReceiveThread;
+        Thread unicastReceiverThread = mdnsClient.unicastReceiveThread;
+        Thread sendThread = mdnsClient.sendThread;
+
+        assertTrue(multicastReceiverThread.isAlive());
+        assertTrue(sendThread.isAlive());
+        assertNull(unicastReceiverThread);
+
+        // Sends a packet.
+        DatagramPacket packet = new DatagramPacket(buf, 0, 5);
+        mdnsClient.sendMulticastPacket(packet);
+        // mockMulticastSocket.send() will be called on another thread. If we verify it immediately,
+        // it may not be called yet. So timeout is added.
+        verify(mockMulticastSocket, timeout(TIMEOUT).times(1)).send(packet);
+        verify(mockUnicastSocket, timeout(TIMEOUT).times(0)).send(packet);
+
+        // Verify the packet is sent by the multicast socket as well.
+        mdnsClient.sendUnicastPacket(packet);
+        verify(mockMulticastSocket, timeout(TIMEOUT).times(2)).send(packet);
+        verify(mockUnicastSocket, timeout(TIMEOUT).times(0)).send(packet);
+
+        // Stop the MdnsClient, and ensure that it stops in a reasonable amount of time.
+        // Run part of the test logic in a background thread, in case stopDiscovery() blocks
+        // for a long time (the foreground thread can fail the test early).
+        final CountDownLatch stopDiscoveryLatch = new CountDownLatch(1);
+        Thread testThread =
+                new Thread(
+                        new Runnable() {
+                            @RequiresPermission(permission.CHANGE_WIFI_MULTICAST_STATE)
+                            @Override
+                            public void run() {
+                                mdnsClient.stopDiscovery();
+                                stopDiscoveryLatch.countDown();
+                            }
+                        });
+        testThread.start();
+        assertTrue(stopDiscoveryLatch.await(DateUtils.SECOND_IN_MILLIS, TimeUnit.MILLISECONDS));
+
+        // We should be able to join in a reasonable amount of time, to prove that the
+        // the MdnsClient exited without sending the large queue of packets.
+        testThread.join(DateUtils.SECOND_IN_MILLIS);
+
+        assertFalse(multicastReceiverThread.isAlive());
+        assertFalse(sendThread.isAlive());
+        assertNull(unicastReceiverThread);
+    }
+
+    @Test
+    public void testStartStop() throws IOException {
+        for (int i = 0; i < 5; i++) {
+            mdnsClient.startDiscovery();
+
+            Thread multicastReceiverThread = mdnsClient.multicastReceiveThread;
+            Thread socketThread = mdnsClient.sendThread;
+
+            assertTrue(multicastReceiverThread.isAlive());
+            assertTrue(socketThread.isAlive());
+
+            mdnsClient.stopDiscovery();
+
+            assertFalse(multicastReceiverThread.isAlive());
+            assertFalse(socketThread.isAlive());
+        }
+    }
+
+    @Test
+    public void testStopDiscovery_queueIsCleared() throws IOException {
+        mdnsClient.startDiscovery();
+        mdnsClient.stopDiscovery();
+        mdnsClient.sendMulticastPacket(new DatagramPacket(buf, 0, 5));
+
+        synchronized (mdnsClient.multicastPacketQueue) {
+            assertTrue(mdnsClient.multicastPacketQueue.isEmpty());
+        }
+    }
+
+    @Test
+    public void testSendPacket_afterDiscoveryStops() throws IOException {
+        mdnsClient.startDiscovery();
+        mdnsClient.stopDiscovery();
+        mdnsClient.sendMulticastPacket(new DatagramPacket(buf, 0, 5));
+
+        synchronized (mdnsClient.multicastPacketQueue) {
+            assertTrue(mdnsClient.multicastPacketQueue.isEmpty());
+        }
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testSendPacket_queueReachesSizeLimit() throws IOException {
+        //MdnsConfigsFlagsImpl.mdnsPacketQueueMaxSize.override(2L);
+        mdnsClient.startDiscovery();
+        for (int i = 0; i < 100; i++) {
+            mdnsClient.sendMulticastPacket(new DatagramPacket(buf, 0, 5));
+        }
+
+        synchronized (mdnsClient.multicastPacketQueue) {
+            assertTrue(mdnsClient.multicastPacketQueue.size() <= 2);
+        }
+    }
+
+    @Test
+    public void testMulticastResponseReceived_useSeparateSocketForUnicast() throws IOException {
+        mdnsClient.setCallback(mockCallback);
+
+        mdnsClient.startDiscovery();
+
+        verify(mockCallback, timeout(TIMEOUT).atLeast(1))
+                .onResponseReceived(any(MdnsResponse.class));
+    }
+
+    @Test
+    public void testMulticastResponseReceived_useSameSocketForMulticastAndUnicast()
+            throws Exception {
+        mdnsClient.startDiscovery();
+
+        verify(mockCallback, timeout(TIMEOUT).atLeastOnce())
+                .onResponseReceived(any(MdnsResponse.class));
+
+        mdnsClient.stopDiscovery();
+    }
+
+    @Test
+    public void testFailedToParseMdnsResponse_useSeparateSocketForUnicast() throws IOException {
+        mdnsClient.setCallback(mockCallback);
+
+        // Both multicast socket and unicast socket receive malformed responses.
+        byte[] dataIn = HexDump.hexStringToByteArray("0000840000000004");
+        doAnswer(
+                (InvocationOnMock invocationOnMock) -> {
+                    // Malformed data.
+                    DatagramPacket packet = invocationOnMock.getArgument(0);
+                    packet.setData(dataIn);
+                    return null;
+                })
+                .when(mockMulticastSocket)
+                .receive(any(DatagramPacket.class));
+        doAnswer(
+                (InvocationOnMock invocationOnMock) -> {
+                    // Malformed data.
+                    DatagramPacket packet = invocationOnMock.getArgument(0);
+                    packet.setData(dataIn);
+                    return null;
+                })
+                .when(mockUnicastSocket)
+                .receive(any(DatagramPacket.class));
+
+        mdnsClient.startDiscovery();
+
+        verify(mockCallback, timeout(TIMEOUT).atLeast(1))
+                .onFailedToParseMdnsResponse(anyInt(), eq(MdnsResponseErrorCode.ERROR_END_OF_FILE));
+
+        mdnsClient.stopDiscovery();
+    }
+
+    @Test
+    public void testFailedToParseMdnsResponse_useSameSocketForMulticastAndUnicast()
+            throws IOException {
+        doAnswer(
+                (InvocationOnMock invocationOnMock) -> {
+                    final byte[] dataIn = HexDump.hexStringToByteArray("0000840000000004");
+                    DatagramPacket packet = invocationOnMock.getArgument(0);
+                    packet.setData(dataIn);
+                    return null;
+                })
+                .when(mockMulticastSocket)
+                .receive(any(DatagramPacket.class));
+
+        mdnsClient.startDiscovery();
+
+        verify(mockCallback, timeout(TIMEOUT).atLeast(1))
+                .onFailedToParseMdnsResponse(1, MdnsResponseErrorCode.ERROR_END_OF_FILE);
+
+        mdnsClient.stopDiscovery();
+    }
+
+    @Test
+    @Ignore("MdnsConfigs is not configurable currently.")
+    public void testMulticastResponseIsNotReceived() throws IOException, InterruptedException {
+        //MdnsConfigsFlagsImpl.checkMulticastResponse.override(true);
+        //MdnsConfigsFlagsImpl.checkMulticastResponseIntervalMs
+        //        .override(DateUtils.SECOND_IN_MILLIS);
+        //MdnsConfigsFlagsImpl.useSeparateSocketToSendUnicastQuery.override(true);
+        enableMulticastResponse.set(false);
+        enableUnicastResponse.set(true);
+
+        mdnsClient.startDiscovery();
+        DatagramPacket packet = new DatagramPacket(buf, 0, 5);
+        mdnsClient.sendUnicastPacket(packet);
+        mdnsClient.sendMulticastPacket(packet);
+
+        // Wait for the timer to be triggered.
+        Thread.sleep(MdnsConfigs.checkMulticastResponseIntervalMs() * 2);
+
+        assertFalse(mdnsClient.receivedMulticastResponse);
+        assertTrue(mdnsClient.receivedUnicastResponse);
+        assertTrue(mdnsClient.cannotReceiveMulticastResponse.get());
+
+        // Allow multicast response and verify the states again.
+        enableMulticastResponse.set(true);
+        Thread.sleep(DateUtils.SECOND_IN_MILLIS);
+
+        // Verify cannotReceiveMulticastResponse is reset to false.
+        assertTrue(mdnsClient.receivedMulticastResponse);
+        assertTrue(mdnsClient.receivedUnicastResponse);
+        assertFalse(mdnsClient.cannotReceiveMulticastResponse.get());
+
+        // Stop the discovery and start a new session. Don't respond the unicsat query either in
+        // this session.
+        enableMulticastResponse.set(false);
+        enableUnicastResponse.set(false);
+        mdnsClient.stopDiscovery();
+        mdnsClient.startDiscovery();
+
+        // Verify the states are reset.
+        assertFalse(mdnsClient.receivedMulticastResponse);
+        assertFalse(mdnsClient.receivedUnicastResponse);
+        assertFalse(mdnsClient.cannotReceiveMulticastResponse.get());
+
+        mdnsClient.sendUnicastPacket(packet);
+        mdnsClient.sendMulticastPacket(packet);
+        Thread.sleep(MdnsConfigs.checkMulticastResponseIntervalMs() * 2);
+
+        // Verify cannotReceiveMulticastResponse is not set the true because we didn't receive the
+        // unicast response either. This is expected for users who don't have any cast device.
+        assertFalse(mdnsClient.receivedMulticastResponse);
+        assertFalse(mdnsClient.receivedUnicastResponse);
+        assertFalse(mdnsClient.cannotReceiveMulticastResponse.get());
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketTests.java
new file mode 100644
index 0000000..9f11a4b
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketTests.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.net.DatagramPacket;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.MulticastSocket;
+import java.net.NetworkInterface;
+import java.net.SocketAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.util.Collections;
+
+/** Tests for {@link MdnsSocket}. */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MdnsSocketTests {
+
+    @Mock private NetworkInterfaceWrapper mockNetworkInterfaceWrapper;
+    @Mock private MulticastSocket mockMulticastSocket;
+    @Mock private MulticastNetworkInterfaceProvider mockMulticastNetworkInterfaceProvider;
+    private SocketAddress socketIPv4Address;
+    private SocketAddress socketIPv6Address;
+
+    private byte[] data = new byte[25];
+    private final DatagramPacket datagramPacket = new DatagramPacket(data, data.length);
+    private NetworkInterface networkInterface;
+
+    private MdnsSocket mdnsSocket;
+
+    @Before
+    public void setUp() throws SocketException, UnknownHostException {
+        MockitoAnnotations.initMocks(this);
+
+        networkInterface = createEmptyNetworkInterface();
+        when(mockNetworkInterfaceWrapper.getNetworkInterface()).thenReturn(networkInterface);
+        when(mockMulticastNetworkInterfaceProvider.getMulticastNetworkInterfaces())
+                .thenReturn(Collections.singletonList(mockNetworkInterfaceWrapper));
+        socketIPv4Address = new InetSocketAddress(
+                InetAddress.getByName("224.0.0.251"), MdnsConstants.MDNS_PORT);
+        socketIPv6Address = new InetSocketAddress(
+                InetAddress.getByName("FF02::FB"), MdnsConstants.MDNS_PORT);
+    }
+
+    @Test
+    public void testMdnsSocket() throws IOException {
+        mdnsSocket =
+                new MdnsSocket(mockMulticastNetworkInterfaceProvider, MdnsConstants.MDNS_PORT) {
+                    @Override
+                    MulticastSocket createMulticastSocket(int port) throws IOException {
+                        return mockMulticastSocket;
+                    }
+                };
+        mdnsSocket.send(datagramPacket);
+        verify(mockMulticastSocket).setNetworkInterface(networkInterface);
+        verify(mockMulticastSocket).send(datagramPacket);
+
+        mdnsSocket.receive(datagramPacket);
+        verify(mockMulticastSocket).receive(datagramPacket);
+
+        mdnsSocket.joinGroup();
+        verify(mockMulticastSocket).joinGroup(socketIPv4Address, networkInterface);
+
+        mdnsSocket.leaveGroup();
+        verify(mockMulticastSocket).leaveGroup(socketIPv4Address, networkInterface);
+
+        mdnsSocket.close();
+        verify(mockMulticastSocket).close();
+    }
+
+    @Test
+    public void testIPv6OnlyNetwork_IPv6Enabled() throws IOException {
+        // Have mockMulticastNetworkInterfaceProvider send back an IPv6Only networkInterfaceWrapper
+        networkInterface = createEmptyNetworkInterface();
+        when(mockNetworkInterfaceWrapper.getNetworkInterface()).thenReturn(networkInterface);
+        when(mockMulticastNetworkInterfaceProvider.getMulticastNetworkInterfaces())
+                .thenReturn(Collections.singletonList(mockNetworkInterfaceWrapper));
+
+        mdnsSocket =
+                new MdnsSocket(mockMulticastNetworkInterfaceProvider, MdnsConstants.MDNS_PORT) {
+                    @Override
+                    MulticastSocket createMulticastSocket(int port) throws IOException {
+                        return mockMulticastSocket;
+                    }
+                };
+
+        when(mockMulticastNetworkInterfaceProvider.isOnIpV6OnlyNetwork(
+                Collections.singletonList(mockNetworkInterfaceWrapper)))
+                .thenReturn(true);
+
+        mdnsSocket.joinGroup();
+        verify(mockMulticastSocket).joinGroup(socketIPv6Address, networkInterface);
+
+        mdnsSocket.leaveGroup();
+        verify(mockMulticastSocket).leaveGroup(socketIPv6Address, networkInterface);
+
+        mdnsSocket.close();
+        verify(mockMulticastSocket).close();
+    }
+
+    @Test
+    public void testIPv6OnlyNetwork_IPv6Toggle() throws IOException {
+        // Have mockMulticastNetworkInterfaceProvider send back a networkInterfaceWrapper
+        networkInterface = createEmptyNetworkInterface();
+        when(mockNetworkInterfaceWrapper.getNetworkInterface()).thenReturn(networkInterface);
+        when(mockMulticastNetworkInterfaceProvider.getMulticastNetworkInterfaces())
+                .thenReturn(Collections.singletonList(mockNetworkInterfaceWrapper));
+
+        mdnsSocket =
+                new MdnsSocket(mockMulticastNetworkInterfaceProvider, MdnsConstants.MDNS_PORT) {
+                    @Override
+                    MulticastSocket createMulticastSocket(int port) throws IOException {
+                        return mockMulticastSocket;
+                    }
+                };
+
+        when(mockMulticastNetworkInterfaceProvider.isOnIpV6OnlyNetwork(
+                Collections.singletonList(mockNetworkInterfaceWrapper)))
+                .thenReturn(true);
+
+        mdnsSocket.joinGroup();
+        verify(mockMulticastSocket).joinGroup(socketIPv6Address, networkInterface);
+
+        mdnsSocket.leaveGroup();
+        verify(mockMulticastSocket).leaveGroup(socketIPv6Address, networkInterface);
+
+        mdnsSocket.close();
+        verify(mockMulticastSocket).close();
+    }
+
+    private NetworkInterface createEmptyNetworkInterface() {
+        try {
+            Constructor<NetworkInterface> constructor =
+                    NetworkInterface.class.getDeclaredConstructor();
+            constructor.setAccessible(true);
+            return constructor.newInstance();
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProviderTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProviderTests.java
new file mode 100644
index 0000000..2268dfe
--- /dev/null
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MulticastNetworkInterfaceProviderTests.java
@@ -0,0 +1,275 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.server.connectivity.mdns;
+
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import android.annotation.NonNull;
+import android.content.Context;
+
+import androidx.test.InstrumentationRegistry;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.InterfaceAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/** Tests for {@link MulticastNetworkInterfaceProvider}. */
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
+public class MulticastNetworkInterfaceProviderTests {
+
+    @Mock private NetworkInterfaceWrapper loopbackInterface;
+    @Mock private NetworkInterfaceWrapper pointToPointInterface;
+    @Mock private NetworkInterfaceWrapper virtualInterface;
+    @Mock private NetworkInterfaceWrapper inactiveMulticastInterface;
+    @Mock private NetworkInterfaceWrapper activeIpv6MulticastInterface;
+    @Mock private NetworkInterfaceWrapper activeIpv6MulticastInterfaceTwo;
+    @Mock private NetworkInterfaceWrapper nonMulticastInterface;
+    @Mock private NetworkInterfaceWrapper multicastInterfaceOne;
+    @Mock private NetworkInterfaceWrapper multicastInterfaceTwo;
+
+    private final List<NetworkInterfaceWrapper> networkInterfaces = new ArrayList<>();
+    private MulticastNetworkInterfaceProvider provider;
+    private Context context;
+
+    @Before
+    public void setUp() throws SocketException, UnknownHostException {
+        MockitoAnnotations.initMocks(this);
+        context = InstrumentationRegistry.getContext();
+
+        setupNetworkInterface(
+                loopbackInterface,
+                true /* isUp */,
+                true /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                pointToPointInterface,
+                true /* isUp */,
+                false /* isLoopBack */,
+                true /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                virtualInterface,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                true /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                inactiveMulticastInterface,
+                false /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                nonMulticastInterface,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                false /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                activeIpv6MulticastInterface,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                true /* isIpv6 */);
+
+        setupNetworkInterface(
+                activeIpv6MulticastInterfaceTwo,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                true /* isIpv6 */);
+
+        setupNetworkInterface(
+                multicastInterfaceOne,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        setupNetworkInterface(
+                multicastInterfaceTwo,
+                true /* isUp */,
+                false /* isLoopBack */,
+                false /* isPointToPoint */,
+                false /* isVirtual */,
+                true /* supportsMulticast */,
+                false /* isIpv6 */);
+
+        provider =
+                new MulticastNetworkInterfaceProvider(context) {
+                    @Override
+                    List<NetworkInterfaceWrapper> getNetworkInterfaces() {
+                        return networkInterfaces;
+                    }
+                };
+    }
+
+    @Test
+    public void testGetMulticastNetworkInterfaces() {
+        // getNetworkInterfaces returns 1 multicast interface and 5 interfaces that can not be used
+        // to send and receive multicast packets.
+        networkInterfaces.add(loopbackInterface);
+        networkInterfaces.add(pointToPointInterface);
+        networkInterfaces.add(virtualInterface);
+        networkInterfaces.add(inactiveMulticastInterface);
+        networkInterfaces.add(nonMulticastInterface);
+        networkInterfaces.add(multicastInterfaceOne);
+
+        assertEquals(Collections.singletonList(multicastInterfaceOne),
+                provider.getMulticastNetworkInterfaces());
+
+        // getNetworkInterfaces returns 2 multicast interfaces after a connectivity change.
+        networkInterfaces.clear();
+        networkInterfaces.add(multicastInterfaceOne);
+        networkInterfaces.add(multicastInterfaceTwo);
+
+        provider.connectivityMonitor.notifyConnectivityChange();
+
+        assertEquals(networkInterfaces, provider.getMulticastNetworkInterfaces());
+    }
+
+    @Test
+    public void testStartWatchingConnectivityChanges() {
+        ConnectivityMonitor mockMonitor = mock(ConnectivityMonitor.class);
+        provider.connectivityMonitor = mockMonitor;
+
+        InOrder inOrder = inOrder(mockMonitor);
+
+        provider.startWatchingConnectivityChanges();
+        inOrder.verify(mockMonitor).startWatchingConnectivityChanges();
+
+        provider.stopWatchingConnectivityChanges();
+        inOrder.verify(mockMonitor).stopWatchingConnectivityChanges();
+    }
+
+    @Test
+    public void testIpV6OnlyNetwork_EmptyNetwork() {
+        // getNetworkInterfaces returns no network interfaces.
+        assertFalse(provider.isOnIpV6OnlyNetwork(networkInterfaces));
+    }
+
+    @Test
+    public void testIpV6OnlyNetwork_IPv4Only() {
+        // getNetworkInterfaces returns two IPv4 network interface.
+        networkInterfaces.add(multicastInterfaceOne);
+        networkInterfaces.add(multicastInterfaceTwo);
+        assertFalse(provider.isOnIpV6OnlyNetwork(networkInterfaces));
+    }
+
+    @Test
+    public void testIpV6OnlyNetwork_MixedNetwork() {
+        // getNetworkInterfaces returns one IPv6 network interface.
+        networkInterfaces.add(activeIpv6MulticastInterface);
+        networkInterfaces.add(multicastInterfaceOne);
+        networkInterfaces.add(activeIpv6MulticastInterfaceTwo);
+        networkInterfaces.add(multicastInterfaceTwo);
+        assertFalse(provider.isOnIpV6OnlyNetwork(networkInterfaces));
+    }
+
+    @Test
+    public void testIpV6OnlyNetwork_IPv6Only() {
+        // getNetworkInterfaces returns one IPv6 network interface.
+        networkInterfaces.add(activeIpv6MulticastInterface);
+        networkInterfaces.add(activeIpv6MulticastInterfaceTwo);
+        assertTrue(provider.isOnIpV6OnlyNetwork(networkInterfaces));
+    }
+
+    @Test
+    public void testIpV6OnlyNetwork_IPv6Enabled() {
+        // getNetworkInterfaces returns one IPv6 network interface.
+        networkInterfaces.add(activeIpv6MulticastInterface);
+        assertTrue(provider.isOnIpV6OnlyNetwork(networkInterfaces));
+
+        final List<NetworkInterfaceWrapper> interfaces = provider.getMulticastNetworkInterfaces();
+        assertEquals(Collections.singletonList(activeIpv6MulticastInterface), interfaces);
+    }
+
+    private void setupNetworkInterface(
+            @NonNull NetworkInterfaceWrapper networkInterfaceWrapper,
+            boolean isUp,
+            boolean isLoopback,
+            boolean isPointToPoint,
+            boolean isVirtual,
+            boolean supportsMulticast,
+            boolean isIpv6)
+            throws SocketException, UnknownHostException {
+        when(networkInterfaceWrapper.isUp()).thenReturn(isUp);
+        when(networkInterfaceWrapper.isLoopback()).thenReturn(isLoopback);
+        when(networkInterfaceWrapper.isPointToPoint()).thenReturn(isPointToPoint);
+        when(networkInterfaceWrapper.isVirtual()).thenReturn(isVirtual);
+        when(networkInterfaceWrapper.supportsMulticast()).thenReturn(supportsMulticast);
+        if (isIpv6) {
+            InterfaceAddress interfaceAddress = mock(InterfaceAddress.class);
+            InetAddress ip6Address = Inet6Address.getByName("2001:4860:0:1001::68");
+            when(interfaceAddress.getAddress()).thenReturn(ip6Address);
+            when(networkInterfaceWrapper.getInterfaceAddresses())
+                    .thenReturn(Collections.singletonList(interfaceAddress));
+        } else {
+            Inet4Address ip = (Inet4Address) Inet4Address.getByName("192.168.0.1");
+            InterfaceAddress interfaceAddress = mock(InterfaceAddress.class);
+            when(interfaceAddress.getAddress()).thenReturn(ip);
+            when(networkInterfaceWrapper.getInterfaceAddresses())
+                    .thenReturn(Collections.singletonList(interfaceAddress));
+        }
+    }
+}
\ No newline at end of file
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetNetworkFactoryTest.java b/tests/unit/java/com/android/server/ethernet/EthernetNetworkFactoryTest.java
index 9a8a72f..2178b33 100644
--- a/tests/unit/java/com/android/server/ethernet/EthernetNetworkFactoryTest.java
+++ b/tests/unit/java/com/android/server/ethernet/EthernetNetworkFactoryTest.java
@@ -16,8 +16,6 @@
 
 package com.android.server.ethernet;
 
-import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotSame;
@@ -55,20 +53,20 @@
 import android.net.StaticIpConfiguration;
 import android.net.ip.IpClientCallbacks;
 import android.net.ip.IpClientManager;
+import android.os.Build;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.test.TestLooper;
 
 import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
 
 import com.android.net.module.util.InterfaceParams;
 import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
@@ -80,8 +78,9 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
-@RunWith(AndroidJUnit4.class)
 @SmallTest
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class EthernetNetworkFactoryTest {
     private static final int TIMEOUT_MS = 2_000;
     private static final String TEST_IFACE = "test123";
@@ -302,7 +301,6 @@
         clearInvocations(mNetworkAgent);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceLinkStateForActiveProvisioningInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -318,7 +316,6 @@
         assertEquals(listener.expectOnResult(), TEST_IFACE);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceLinkStateForProvisionedInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -333,7 +330,6 @@
         assertEquals(listener.expectOnResult(), TEST_IFACE);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceLinkStateForUnprovisionedInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -351,7 +347,6 @@
         assertEquals(listener.expectOnResult(), TEST_IFACE);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceLinkStateForNonExistingInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -366,7 +361,6 @@
         listener.expectOnError();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceLinkStateWithNoChanges() throws Exception {
         initEthernetNetworkFactory();
@@ -381,7 +375,6 @@
         listener.expectOnError();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testProvisioningLoss() throws Exception {
         initEthernetNetworkFactory();
@@ -394,7 +387,6 @@
         verify(mIpClient).startProvisioning(any());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testProvisioningLossForDisappearedInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -416,7 +408,6 @@
         verify(mIpClient, never()).startProvisioning(any());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testLinkPropertiesChanged() throws Exception {
         initEthernetNetworkFactory();
@@ -428,7 +419,6 @@
         verify(mNetworkAgent).sendLinkPropertiesImpl(same(lp));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testNetworkUnwanted() throws Exception {
         initEthernetNetworkFactory();
@@ -439,7 +429,6 @@
         verifyStop();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testNetworkUnwantedWithStaleNetworkAgent() throws Exception {
         initEthernetNetworkFactory();
@@ -464,7 +453,6 @@
         verify(mNetworkAgent, never()).unregister();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testTransportOverrideIsCorrectlySet() throws Exception {
         initEthernetNetworkFactory();
@@ -486,7 +474,6 @@
                 ConnectivityManager.TYPE_NONE);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testReachabilityLoss() throws Exception {
         initEthernetNetworkFactory();
@@ -507,7 +494,6 @@
         return staleIpClientCallbacks;
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIgnoreOnIpLayerStartedCallbackForStaleCallback() throws Exception {
         initEthernetNetworkFactory();
@@ -520,7 +506,6 @@
         verify(mNetworkAgent, never()).register();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIgnoreOnIpLayerStoppedCallbackForStaleCallback() throws Exception {
         initEthernetNetworkFactory();
@@ -533,7 +518,6 @@
         verify(mIpClient, never()).startProvisioning(any());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIgnoreLinkPropertiesCallbackForStaleCallback() throws Exception {
         initEthernetNetworkFactory();
@@ -546,7 +530,6 @@
         verify(mNetworkAgent, never()).sendLinkPropertiesImpl(eq(lp));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIgnoreNeighborLossCallbackForStaleCallback() throws Exception {
         initEthernetNetworkFactory();
@@ -615,7 +598,6 @@
         }
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceCallsListenerCorrectlyOnSuccess() throws Exception {
         initEthernetNetworkFactory();
@@ -630,8 +612,6 @@
         assertEquals(listener.expectOnResult(), TEST_IFACE);
     }
 
-    @DevSdkIgnoreRule.IgnoreUpTo(SC_V2) // TODO: Use to Build.VERSION_CODES.SC_V2 when available
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceAbortsOnConcurrentRemoveInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -640,8 +620,6 @@
                 () -> mNetFactory.removeInterface(TEST_IFACE));
     }
 
-    @DevSdkIgnoreRule.IgnoreUpTo(SC_V2) // TODO: Use to Build.VERSION_CODES.SC_V2 when available
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceAbortsOnConcurrentUpdateInterfaceLinkState() throws Exception {
         initEthernetNetworkFactory();
@@ -650,8 +628,6 @@
                 () -> mNetFactory.updateInterfaceLinkState(TEST_IFACE, false, NULL_LISTENER));
     }
 
-    @DevSdkIgnoreRule.IgnoreUpTo(SC_V2) // TODO: Use to Build.VERSION_CODES.SC_V2 when available
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceAbortsOnNetworkUneededRemovesAllRequests() throws Exception {
         initEthernetNetworkFactory();
@@ -696,7 +672,6 @@
         failedListener.expectOnError();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceRestartsAgentCorrectly() throws Exception {
         initEthernetNetworkFactory();
@@ -714,7 +689,6 @@
         verifyRestart(ipConfiguration);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceForNonExistingInterface() throws Exception {
         initEthernetNetworkFactory();
@@ -729,7 +703,6 @@
         listener.expectOnError();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateInterfaceWithNullIpConfiguration() throws Exception {
         initEthernetNetworkFactory();
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetServiceImplTest.java b/tests/unit/java/com/android/server/ethernet/EthernetServiceImplTest.java
index e8e54f8..a1d93a0 100644
--- a/tests/unit/java/com/android/server/ethernet/EthernetServiceImplTest.java
+++ b/tests/unit/java/com/android/server/ethernet/EthernetServiceImplTest.java
@@ -16,16 +16,17 @@
 
 package com.android.server.ethernet;
 
+import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
 import static android.net.NetworkCapabilities.TRANSPORT_TEST;
 
 import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.fail;
-
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.isNull;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.verify;
@@ -35,30 +36,37 @@
 import android.annotation.NonNull;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.net.INetworkInterfaceOutcomeReceiver;
+import android.net.EthernetNetworkSpecifier;
 import android.net.EthernetNetworkUpdateRequest;
+import android.net.INetworkInterfaceOutcomeReceiver;
 import android.net.IpConfiguration;
 import android.net.NetworkCapabilities;
+import android.net.StringNetworkSpecifier;
+import android.os.Build;
 import android.os.Handler;
 
 import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
 
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.mockito.Mock;
-import org.mockito.MockitoAnnotations;
 
-@RunWith(AndroidJUnit4.class)
 @SmallTest
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class EthernetServiceImplTest {
     private static final String TEST_IFACE = "test123";
+    private static final NetworkCapabilities DEFAULT_CAPS = new NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_ETHERNET)
+            .setNetworkSpecifier(new EthernetNetworkSpecifier(TEST_IFACE))
+            .build();
     private static final EthernetNetworkUpdateRequest UPDATE_REQUEST =
             new EthernetNetworkUpdateRequest.Builder()
                     .setIpConfiguration(new IpConfiguration())
-                    .setNetworkCapabilities(new NetworkCapabilities.Builder().build())
+                    .setNetworkCapabilities(DEFAULT_CAPS)
                     .build();
     private static final EthernetNetworkUpdateRequest UPDATE_REQUEST_WITHOUT_CAPABILITIES =
             new EthernetNetworkUpdateRequest.Builder()
@@ -66,18 +74,21 @@
                     .build();
     private static final EthernetNetworkUpdateRequest UPDATE_REQUEST_WITHOUT_IP_CONFIG =
             new EthernetNetworkUpdateRequest.Builder()
-                    .setNetworkCapabilities(new NetworkCapabilities.Builder().build())
+                    .setNetworkCapabilities(DEFAULT_CAPS)
                     .build();
     private static final INetworkInterfaceOutcomeReceiver NULL_LISTENER = null;
     private EthernetServiceImpl mEthernetServiceImpl;
-    @Mock private Context mContext;
-    @Mock private Handler mHandler;
-    @Mock private EthernetTracker mEthernetTracker;
-    @Mock private PackageManager mPackageManager;
+    private Context mContext;
+    private Handler mHandler;
+    private EthernetTracker mEthernetTracker;
+    private PackageManager mPackageManager;
 
     @Before
     public void setup() {
-        MockitoAnnotations.initMocks(this);
+        mContext = mock(Context.class);
+        mHandler = mock(Handler.class);
+        mEthernetTracker = mock(EthernetTracker.class);
+        mPackageManager = mock(PackageManager.class);
         doReturn(mPackageManager).when(mContext).getPackageManager();
         mEthernetServiceImpl = new EthernetServiceImpl(mContext, mHandler, mEthernetTracker);
         mEthernetServiceImpl.mStarted.set(true);
@@ -94,7 +105,6 @@
         doReturn(shouldTrack).when(mEthernetTracker).isTrackingInterface(iface);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testSetConfigurationRejectsWhenEthNotStarted() {
         mEthernetServiceImpl.mStarted.set(false);
@@ -103,7 +113,6 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationRejectsWhenEthNotStarted() {
         mEthernetServiceImpl.mStarted.set(false);
@@ -113,25 +122,22 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkRejectsWhenEthNotStarted() {
+    public void testEnableInterfaceRejectsWhenEthNotStarted() {
         mEthernetServiceImpl.mStarted.set(false);
         assertThrows(IllegalStateException.class, () -> {
-            mEthernetServiceImpl.connectNetwork("" /* iface */, null /* listener */);
+            mEthernetServiceImpl.enableInterface("" /* iface */, null /* listener */);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkRejectsWhenEthNotStarted() {
+    public void testDisableInterfaceRejectsWhenEthNotStarted() {
         mEthernetServiceImpl.mStarted.set(false);
         assertThrows(IllegalStateException.class, () -> {
-            mEthernetServiceImpl.disconnectNetwork("" /* iface */, null /* listener */);
+            mEthernetServiceImpl.disableInterface("" /* iface */, null /* listener */);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationRejectsNullIface() {
         assertThrows(NullPointerException.class, () -> {
@@ -139,23 +145,20 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkRejectsNullIface() {
+    public void testEnableInterfaceRejectsNullIface() {
         assertThrows(NullPointerException.class, () -> {
-            mEthernetServiceImpl.connectNetwork(null /* iface */, NULL_LISTENER);
+            mEthernetServiceImpl.enableInterface(null /* iface */, NULL_LISTENER);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkRejectsNullIface() {
+    public void testDisableInterfaceRejectsNullIface() {
         assertThrows(NullPointerException.class, () -> {
-            mEthernetServiceImpl.disconnectNetwork(null /* iface */, NULL_LISTENER);
+            mEthernetServiceImpl.disableInterface(null /* iface */, NULL_LISTENER);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationWithCapabilitiesRejectsWithoutAutomotiveFeature() {
         toggleAutomotiveFeature(false);
@@ -164,7 +167,41 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
+    @Test
+    public void testUpdateConfigurationRejectsWithInvalidSpecifierType() {
+        final StringNetworkSpecifier invalidSpecifierType = new StringNetworkSpecifier("123");
+        final EthernetNetworkUpdateRequest request =
+                new EthernetNetworkUpdateRequest.Builder()
+                        .setNetworkCapabilities(
+                                new NetworkCapabilities.Builder()
+                                        .addTransportType(TRANSPORT_ETHERNET)
+                                        .setNetworkSpecifier(invalidSpecifierType)
+                                        .build()
+                        ).build();
+        assertThrows(IllegalArgumentException.class, () -> {
+            mEthernetServiceImpl.updateConfiguration(
+                    "" /* iface */, request, null /* listener */);
+        });
+    }
+
+    @Test
+    public void testUpdateConfigurationRejectsWithInvalidSpecifierName() {
+        final String ifaceToUpdate = "eth0";
+        final String ifaceOnSpecifier = "wlan0";
+        EthernetNetworkUpdateRequest request =
+                new EthernetNetworkUpdateRequest.Builder()
+                        .setNetworkCapabilities(
+                                new NetworkCapabilities.Builder()
+                                        .addTransportType(TRANSPORT_ETHERNET)
+                                        .setNetworkSpecifier(
+                                                new EthernetNetworkSpecifier(ifaceOnSpecifier))
+                                        .build()
+                        ).build();
+        assertThrows(IllegalArgumentException.class, () -> {
+            mEthernetServiceImpl.updateConfiguration(ifaceToUpdate, request, null /* listener */);
+        });
+    }
+
     @Test
     public void testUpdateConfigurationWithCapabilitiesWithAutomotiveFeature() {
         toggleAutomotiveFeature(false);
@@ -175,24 +212,6 @@
                 eq(UPDATE_REQUEST_WITHOUT_CAPABILITIES.getNetworkCapabilities()), isNull());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
-    @Test
-    public void testConnectNetworkRejectsWithoutAutomotiveFeature() {
-        toggleAutomotiveFeature(false);
-        assertThrows(UnsupportedOperationException.class, () -> {
-            mEthernetServiceImpl.connectNetwork("" /* iface */, NULL_LISTENER);
-        });
-    }
-
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
-    @Test
-    public void testDisconnectNetworkRejectsWithoutAutomotiveFeature() {
-        toggleAutomotiveFeature(false);
-        assertThrows(UnsupportedOperationException.class, () -> {
-            mEthernetServiceImpl.disconnectNetwork("" /* iface */, NULL_LISTENER);
-        });
-    }
-
     private void denyManageEthPermission() {
         doThrow(new SecurityException("")).when(mContext)
                 .enforceCallingOrSelfPermission(
@@ -205,7 +224,6 @@
                         eq(Manifest.permission.MANAGE_TEST_NETWORKS), anyString());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationRejectsWithoutManageEthPermission() {
         denyManageEthPermission();
@@ -214,21 +232,19 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkRejectsWithoutManageEthPermission() {
+    public void testEnableInterfaceRejectsWithoutManageEthPermission() {
         denyManageEthPermission();
         assertThrows(SecurityException.class, () -> {
-            mEthernetServiceImpl.connectNetwork(TEST_IFACE, NULL_LISTENER);
+            mEthernetServiceImpl.enableInterface(TEST_IFACE, NULL_LISTENER);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkRejectsWithoutManageEthPermission() {
+    public void testDisableInterfaceRejectsWithoutManageEthPermission() {
         denyManageEthPermission();
         assertThrows(SecurityException.class, () -> {
-            mEthernetServiceImpl.disconnectNetwork(TEST_IFACE, NULL_LISTENER);
+            mEthernetServiceImpl.disableInterface(TEST_IFACE, NULL_LISTENER);
         });
     }
 
@@ -236,7 +252,6 @@
         when(mEthernetTracker.isValidTestInterface(eq(TEST_IFACE))).thenReturn(true);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationRejectsTestRequestWithoutTestPermission() {
         enableTestInterface();
@@ -246,27 +261,24 @@
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkRejectsTestRequestWithoutTestPermission() {
+    public void testEnableInterfaceRejectsTestRequestWithoutTestPermission() {
         enableTestInterface();
         denyManageTestNetworksPermission();
         assertThrows(SecurityException.class, () -> {
-            mEthernetServiceImpl.connectNetwork(TEST_IFACE, NULL_LISTENER);
+            mEthernetServiceImpl.enableInterface(TEST_IFACE, NULL_LISTENER);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkRejectsTestRequestWithoutTestPermission() {
+    public void testDisableInterfaceRejectsTestRequestWithoutTestPermission() {
         enableTestInterface();
         denyManageTestNetworksPermission();
         assertThrows(SecurityException.class, () -> {
-            mEthernetServiceImpl.disconnectNetwork(TEST_IFACE, NULL_LISTENER);
+            mEthernetServiceImpl.disableInterface(TEST_IFACE, NULL_LISTENER);
         });
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfiguration() {
         mEthernetServiceImpl.updateConfiguration(TEST_IFACE, UPDATE_REQUEST, NULL_LISTENER);
@@ -276,21 +288,36 @@
                 eq(UPDATE_REQUEST.getNetworkCapabilities()), eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetwork() {
-        mEthernetServiceImpl.connectNetwork(TEST_IFACE, NULL_LISTENER);
-        verify(mEthernetTracker).connectNetwork(eq(TEST_IFACE), eq(NULL_LISTENER));
+    public void testUpdateConfigurationAddsSpecifierWhenNotSet() {
+        final NetworkCapabilities nc = new NetworkCapabilities.Builder()
+                .addTransportType(TRANSPORT_ETHERNET).build();
+        final EthernetNetworkUpdateRequest requestSansSpecifier =
+                new EthernetNetworkUpdateRequest.Builder()
+                        .setNetworkCapabilities(nc)
+                        .build();
+        final NetworkCapabilities ncWithSpecifier = new NetworkCapabilities(nc)
+                .setNetworkSpecifier(new EthernetNetworkSpecifier(TEST_IFACE));
+
+        mEthernetServiceImpl.updateConfiguration(TEST_IFACE, requestSansSpecifier, NULL_LISTENER);
+        verify(mEthernetTracker).updateConfiguration(
+                eq(TEST_IFACE),
+                isNull(),
+                eq(ncWithSpecifier), eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetwork() {
-        mEthernetServiceImpl.disconnectNetwork(TEST_IFACE, NULL_LISTENER);
-        verify(mEthernetTracker).disconnectNetwork(eq(TEST_IFACE), eq(NULL_LISTENER));
+    public void testEnableInterface() {
+        mEthernetServiceImpl.enableInterface(TEST_IFACE, NULL_LISTENER);
+        verify(mEthernetTracker).enableInterface(eq(TEST_IFACE), eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
+    @Test
+    public void testDisableInterface() {
+        mEthernetServiceImpl.disableInterface(TEST_IFACE, NULL_LISTENER);
+        verify(mEthernetTracker).disableInterface(eq(TEST_IFACE), eq(NULL_LISTENER));
+    }
+
     @Test
     public void testUpdateConfigurationAcceptsTestRequestWithNullCapabilities() {
         enableTestInterface();
@@ -304,7 +331,6 @@
                 eq(request.getNetworkCapabilities()), isNull());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationAcceptsRequestWithNullIpConfiguration() {
         mEthernetServiceImpl.updateConfiguration(TEST_IFACE, UPDATE_REQUEST_WITHOUT_IP_CONFIG,
@@ -314,7 +340,6 @@
                 eq(UPDATE_REQUEST_WITHOUT_IP_CONFIG.getNetworkCapabilities()), isNull());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationRejectsInvalidTestRequest() {
         enableTestInterface();
@@ -333,7 +358,6 @@
                 .setNetworkCapabilities(nc).build();
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfigurationForTestRequestDoesNotRequireAutoOrEthernetPermission() {
         enableTestInterface();
@@ -348,26 +372,24 @@
                 eq(request.getNetworkCapabilities()), eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkForTestRequestDoesNotRequireAutoOrNetPermission() {
+    public void testEnableInterfaceForTestRequestDoesNotRequireNetPermission() {
         enableTestInterface();
         toggleAutomotiveFeature(false);
         denyManageEthPermission();
 
-        mEthernetServiceImpl.connectNetwork(TEST_IFACE, NULL_LISTENER);
-        verify(mEthernetTracker).connectNetwork(eq(TEST_IFACE), eq(NULL_LISTENER));
+        mEthernetServiceImpl.enableInterface(TEST_IFACE, NULL_LISTENER);
+        verify(mEthernetTracker).enableInterface(eq(TEST_IFACE), eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkForTestRequestDoesNotRequireAutoOrNetPermission() {
+    public void testDisableInterfaceForTestRequestDoesNotRequireAutoOrNetPermission() {
         enableTestInterface();
         toggleAutomotiveFeature(false);
         denyManageEthPermission();
 
-        mEthernetServiceImpl.disconnectNetwork(TEST_IFACE, NULL_LISTENER);
-        verify(mEthernetTracker).disconnectNetwork(eq(TEST_IFACE), eq(NULL_LISTENER));
+        mEthernetServiceImpl.disableInterface(TEST_IFACE, NULL_LISTENER);
+        verify(mEthernetTracker).disableInterface(eq(TEST_IFACE), eq(NULL_LISTENER));
     }
 
     private void denyPermissions(String... permissions) {
@@ -377,7 +399,6 @@
         }
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testSetEthernetEnabled() {
         denyPermissions(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
index e90d55d..38094ae 100644
--- a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
+++ b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
@@ -50,17 +50,18 @@
 import android.net.LinkAddress;
 import android.net.NetworkCapabilities;
 import android.net.StaticIpConfiguration;
+import android.os.Build;
 import android.os.HandlerThread;
 import android.os.RemoteException;
 
 import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
 
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
 import com.android.testutils.HandlerUtils;
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
@@ -72,7 +73,8 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 
 @SmallTest
-@RunWith(AndroidJUnit4.class)
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class EthernetTrackerTest {
     private static final String TEST_IFACE = "test123";
     private static final int TIMEOUT_MS = 1_000;
@@ -114,7 +116,6 @@
     /**
      * Test: Creation of various valid static IP configurations
      */
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void createStaticIpConfiguration() {
         // Empty gives default StaticIPConfiguration object
@@ -147,7 +148,6 @@
     /**
      * Test: Attempt creation of various bad static IP configurations
      */
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void createStaticIpConfiguration_Bad() {
         assertStaticConfigurationFails("ip=192.0.2.1/24 gateway= blah=20.20.20.20");  // Unknown key
@@ -191,7 +191,6 @@
     /**
      * Test: Attempt to create a capabilties with various valid sets of capabilities/transports
      */
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void createNetworkCapabilities() {
 
@@ -318,7 +317,6 @@
                         configTransports).build());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testCreateEthernetTrackerConfigReturnsCorrectValue() {
         final String capabilities = "2";
@@ -335,14 +333,12 @@
         assertEquals(transport, config.mTransport);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testCreateEthernetTrackerConfigThrowsNpeWithNullInput() {
         assertThrows(NullPointerException.class,
                 () -> EthernetTracker.createEthernetTrackerConfig(null));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testUpdateConfiguration() {
         final NetworkCapabilities capabilities = new NetworkCapabilities.Builder().build();
@@ -360,27 +356,24 @@
                 eq(TEST_IFACE), eq(ipConfig), eq(capabilities), eq(listener));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testConnectNetworkCorrectlyCallsFactory() {
-        tracker.connectNetwork(TEST_IFACE, NULL_LISTENER);
+    public void testEnableInterfaceCorrectlyCallsFactory() {
+        tracker.enableInterface(TEST_IFACE, NULL_LISTENER);
         waitForIdle();
 
         verify(mFactory).updateInterfaceLinkState(eq(TEST_IFACE), eq(true /* up */),
                 eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
-    public void testDisconnectNetworkCorrectlyCallsFactory() {
-        tracker.disconnectNetwork(TEST_IFACE, NULL_LISTENER);
+    public void testDisableInterfaceCorrectlyCallsFactory() {
+        tracker.disableInterface(TEST_IFACE, NULL_LISTENER);
         waitForIdle();
 
         verify(mFactory).updateInterfaceLinkState(eq(TEST_IFACE), eq(false /* up */),
                 eq(NULL_LISTENER));
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIsValidTestInterfaceIsFalseWhenTestInterfacesAreNotIncluded() {
         final String validIfaceName = TEST_TAP_PREFIX + "123";
@@ -392,7 +385,6 @@
         assertFalse(isValidTestInterface);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIsValidTestInterfaceIsFalseWhenTestInterfaceNameIsInvalid() {
         final String invalidIfaceName = "123" + TEST_TAP_PREFIX;
@@ -404,7 +396,6 @@
         assertFalse(isValidTestInterface);
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testIsValidTestInterfaceIsTrueWhenTestInterfacesIncludedAndValidName() {
         final String validIfaceName = TEST_TAP_PREFIX + "123";
@@ -434,7 +425,6 @@
         return ifaceParcel;
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testListenEthernetStateChange() throws Exception {
         tracker.setIncludeTestInterfaces(true);
@@ -487,7 +477,6 @@
                 anyInt(), any());
     }
 
-    @Ignore("TODO: temporarily ignore tests until prebuilts are updated")
     @Test
     public void testListenEthernetStateChange_unsolicitedEventListener() throws Exception {
         when(mNetd.interfaceGetList()).thenReturn(new String[] {});
diff --git a/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java b/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
index 987b7b7..c6852d1 100644
--- a/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
+++ b/tests/unit/java/com/android/server/net/BpfInterfaceMapUpdaterTest.java
@@ -24,16 +24,18 @@
 import android.content.Context;
 import android.net.INetd;
 import android.net.MacAddress;
+import android.os.Build;
 import android.os.Handler;
 import android.os.test.TestLooper;
 
 import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
 
 import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
 import com.android.net.module.util.IBpfMap;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.Struct.U32;
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -42,8 +44,9 @@
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-@RunWith(AndroidJUnit4.class)
 @SmallTest
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public final class BpfInterfaceMapUpdaterTest {
     private static final int TEST_INDEX = 1;
     private static final int TEST_INDEX2 = 2;
diff --git a/tests/unit/java/com/android/server/net/IpConfigStoreTest.java b/tests/unit/java/com/android/server/net/IpConfigStoreTest.java
index e9a5309..4adc999 100644
--- a/tests/unit/java/com/android/server/net/IpConfigStoreTest.java
+++ b/tests/unit/java/com/android/server/net/IpConfigStoreTest.java
@@ -20,6 +20,7 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
 
+import android.content.Context;
 import android.net.InetAddresses;
 import android.net.IpConfiguration;
 import android.net.IpConfiguration.IpAssignment;
@@ -27,9 +28,15 @@
 import android.net.LinkAddress;
 import android.net.ProxyInfo;
 import android.net.StaticIpConfiguration;
+import android.os.Build;
+import android.os.HandlerThread;
 import android.util.ArrayMap;
 
-import androidx.test.runner.AndroidJUnit4;
+import androidx.test.InstrumentationRegistry;
+
+import com.android.testutils.DevSdkIgnoreRule;
+import com.android.testutils.DevSdkIgnoreRunner;
+import com.android.testutils.HandlerUtils;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -37,17 +44,21 @@
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 
 /**
  * Unit tests for {@link IpConfigStore}
  */
-@RunWith(AndroidJUnit4.class)
+@RunWith(DevSdkIgnoreRunner.class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
 public class IpConfigStoreTest {
+    private static final int TIMEOUT_MS = 2_000;
     private static final int KEY_CONFIG = 17;
     private static final String IFACE_1 = "eth0";
     private static final String IFACE_2 = "eth1";
@@ -56,6 +67,22 @@
     private static final String DNS_IP_ADDR_1 = "1.2.3.4";
     private static final String DNS_IP_ADDR_2 = "5.6.7.8";
 
+    private static final ArrayList<InetAddress> DNS_SERVERS = new ArrayList<>(List.of(
+            InetAddresses.parseNumericAddress(DNS_IP_ADDR_1),
+            InetAddresses.parseNumericAddress(DNS_IP_ADDR_2)));
+    private static final StaticIpConfiguration STATIC_IP_CONFIG_1 =
+            new StaticIpConfiguration.Builder()
+                    .setIpAddress(new LinkAddress(IP_ADDR_1))
+                    .setDnsServers(DNS_SERVERS)
+                    .build();
+    private static final StaticIpConfiguration STATIC_IP_CONFIG_2 =
+            new StaticIpConfiguration.Builder()
+                    .setIpAddress(new LinkAddress(IP_ADDR_2))
+                    .setDnsServers(DNS_SERVERS)
+                    .build();
+    private static final ProxyInfo PROXY_INFO =
+            ProxyInfo.buildDirectProxy("10.10.10.10", 88, Arrays.asList("host1", "host2"));
+
     @Test
     public void backwardCompatibility2to3() throws IOException {
         ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
@@ -79,40 +106,73 @@
 
     @Test
     public void staticIpMultiNetworks() throws Exception {
-        final ArrayList<InetAddress> dnsServers = new ArrayList<>();
-        dnsServers.add(InetAddresses.parseNumericAddress(DNS_IP_ADDR_1));
-        dnsServers.add(InetAddresses.parseNumericAddress(DNS_IP_ADDR_2));
-        final StaticIpConfiguration staticIpConfiguration1 = new StaticIpConfiguration.Builder()
-                .setIpAddress(new LinkAddress(IP_ADDR_1))
-                .setDnsServers(dnsServers).build();
-        final StaticIpConfiguration staticIpConfiguration2 = new StaticIpConfiguration.Builder()
-                .setIpAddress(new LinkAddress(IP_ADDR_2))
-                .setDnsServers(dnsServers).build();
+        final IpConfiguration expectedConfig1 = newIpConfiguration(IpAssignment.STATIC,
+                ProxySettings.STATIC, STATIC_IP_CONFIG_1, PROXY_INFO);
+        final IpConfiguration expectedConfig2 = newIpConfiguration(IpAssignment.STATIC,
+                ProxySettings.STATIC, STATIC_IP_CONFIG_2, PROXY_INFO);
 
-        ProxyInfo proxyInfo =
-                ProxyInfo.buildDirectProxy("10.10.10.10", 88, Arrays.asList("host1", "host2"));
-
-        IpConfiguration expectedConfig1 = newIpConfiguration(IpAssignment.STATIC,
-                ProxySettings.STATIC, staticIpConfiguration1, proxyInfo);
-        IpConfiguration expectedConfig2 = newIpConfiguration(IpAssignment.STATIC,
-                ProxySettings.STATIC, staticIpConfiguration2, proxyInfo);
-
-        ArrayMap<String, IpConfiguration> expectedNetworks = new ArrayMap<>();
+        final ArrayMap<String, IpConfiguration> expectedNetworks = new ArrayMap<>();
         expectedNetworks.put(IFACE_1, expectedConfig1);
         expectedNetworks.put(IFACE_2, expectedConfig2);
 
-        MockedDelayedDiskWrite writer = new MockedDelayedDiskWrite();
-        IpConfigStore store = new IpConfigStore(writer);
+        final MockedDelayedDiskWrite writer = new MockedDelayedDiskWrite();
+        final IpConfigStore store = new IpConfigStore(writer);
         store.writeIpConfigurations("file/path/not/used/", expectedNetworks);
 
-        InputStream in = new ByteArrayInputStream(writer.mByteStream.toByteArray());
-        ArrayMap<String, IpConfiguration> actualNetworks = IpConfigStore.readIpConfigurations(in);
+        final InputStream in = new ByteArrayInputStream(writer.mByteStream.toByteArray());
+        final ArrayMap<String, IpConfiguration> actualNetworks =
+                IpConfigStore.readIpConfigurations(in);
         assertNotNull(actualNetworks);
         assertEquals(2, actualNetworks.size());
         assertEquals(expectedNetworks.get(IFACE_1), actualNetworks.get(IFACE_1));
         assertEquals(expectedNetworks.get(IFACE_2), actualNetworks.get(IFACE_2));
     }
 
+    @Test
+    public void readIpConfigurationFromFilePath() throws Exception {
+        final HandlerThread testHandlerThread = new HandlerThread("IpConfigStoreTest");
+        final DelayedDiskWrite.Dependencies dependencies =
+                new DelayedDiskWrite.Dependencies() {
+                    @Override
+                    public HandlerThread makeHandlerThread() {
+                        return testHandlerThread;
+                    }
+                    @Override
+                    public void quitHandlerThread(HandlerThread handlerThread) {
+                        testHandlerThread.quitSafely();
+                    }
+        };
+
+        final IpConfiguration ipConfig = newIpConfiguration(IpAssignment.STATIC,
+                ProxySettings.STATIC, STATIC_IP_CONFIG_1, PROXY_INFO);
+        final ArrayMap<String, IpConfiguration> expectedNetworks = new ArrayMap<>();
+        expectedNetworks.put(IFACE_1, ipConfig);
+
+        // Write IP config to specific file path and read it later.
+        final Context context = InstrumentationRegistry.getContext();
+        final File configFile = new File(context.getFilesDir().getPath(),
+                "IpConfigStoreTest-ipconfig.txt");
+        final DelayedDiskWrite writer = new DelayedDiskWrite(dependencies);
+        final IpConfigStore store = new IpConfigStore(writer);
+        store.writeIpConfigurations(configFile.getPath(), expectedNetworks);
+        HandlerUtils.waitForIdle(testHandlerThread, TIMEOUT_MS);
+
+        // Read IP config from the file path.
+        final ArrayMap<String, IpConfiguration> actualNetworks =
+                IpConfigStore.readIpConfigurations(configFile.getPath());
+        assertNotNull(actualNetworks);
+        assertEquals(1, actualNetworks.size());
+        assertEquals(expectedNetworks.get(IFACE_1), actualNetworks.get(IFACE_1));
+
+        // Return an empty array when reading IP configuration from an non-exist config file.
+        final ArrayMap<String, IpConfiguration> emptyNetworks =
+                IpConfigStore.readIpConfigurations("/dev/null");
+        assertNotNull(emptyNetworks);
+        assertEquals(0, emptyNetworks.size());
+
+        configFile.delete();
+    }
+
     private IpConfiguration newIpConfiguration(IpAssignment ipAssignment,
             ProxySettings proxySettings, StaticIpConfiguration staticIpConfig, ProxyInfo info) {
         final IpConfiguration config = new IpConfiguration();
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsFactoryTest.java b/tests/unit/java/com/android/server/net/NetworkStatsFactoryTest.java
index 79744b1..f6fb45c 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsFactoryTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsFactoryTest.java
@@ -29,6 +29,7 @@
 import static android.net.NetworkStats.UID_ALL;
 
 import static com.android.server.net.NetworkStatsFactory.kernelToTag;
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
@@ -38,12 +39,12 @@
 import android.net.NetworkStats;
 import android.net.TrafficStats;
 import android.net.UnderlyingNetworkInfo;
-import android.os.Build;
 
 import androidx.test.InstrumentationRegistry;
 import androidx.test.filters.SmallTest;
 
 import com.android.frameworks.tests.net.R;
+import com.android.server.BpfNetMaps;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRunner;
 
@@ -67,13 +68,14 @@
 /** Tests for {@link NetworkStatsFactory}. */
 @RunWith(DevSdkIgnoreRunner.class)
 @SmallTest
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
 public class NetworkStatsFactoryTest extends NetworkStatsBaseTest {
     private static final String CLAT_PREFIX = "v4-";
 
     private File mTestProc;
     private NetworkStatsFactory mFactory;
     @Mock private Context mContext;
+    @Mock private BpfNetMaps mBpfNetMaps;
 
     @Before
     public void setUp() throws Exception {
@@ -84,7 +86,7 @@
         // applications. So in order to have a test support native library, the native code
         // related to networkStatsFactory is compiled to a minimal native library and loaded here.
         System.loadLibrary("networkstatsfactorytestjni");
-        mFactory = new NetworkStatsFactory(mContext, mTestProc, false);
+        mFactory = new NetworkStatsFactory(mContext, mTestProc, false, mBpfNetMaps);
         mFactory.updateUnderlyingNetworkInfos(new UnderlyingNetworkInfo[0]);
     }
 
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
index e03b4fe..f9cbb10 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsServiceTest.java
@@ -147,6 +147,17 @@
 import com.android.testutils.TestBpfMap;
 import com.android.testutils.TestableNetworkStatsProviderBinder;
 
+import libcore.testing.io.TestIoUtils;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
@@ -162,17 +173,6 @@
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import libcore.testing.io.TestIoUtils;
-
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Ignore;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Mock;
-import org.mockito.MockitoAnnotations;
-
 /**
  * Tests for {@link NetworkStatsService}.
  *
diff --git a/tests/unit/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java b/tests/unit/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
index 0d34609..622f2be 100644
--- a/tests/unit/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
+++ b/tests/unit/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
@@ -19,6 +19,8 @@
 import static android.telephony.TelephonyDisplayInfo.OVERRIDE_NETWORK_TYPE_NONE;
 import static android.telephony.TelephonyDisplayInfo.OVERRIDE_NETWORK_TYPE_NR_NSA;
 
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
@@ -37,7 +39,6 @@
 import android.annotation.Nullable;
 import android.app.usage.NetworkStatsManager;
 import android.content.Context;
-import android.os.Build;
 import android.os.Looper;
 import android.os.Parcel;
 import android.telephony.SubscriptionManager;
@@ -63,7 +64,7 @@
 import java.util.concurrent.Executors;
 
 @RunWith(DevSdkIgnoreRunner.class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
+@DevSdkIgnoreRule.IgnoreUpTo(SC_V2)
 public final class NetworkStatsSubscriptionsMonitorTest {
     private static final int TEST_SUBID1 = 3;
     private static final int TEST_SUBID2 = 5;
diff --git a/tools/Android.bp b/tools/Android.bp
new file mode 100644
index 0000000..1fa93bb
--- /dev/null
+++ b/tools/Android.bp
@@ -0,0 +1,91 @@
+//
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package {
+    // See: http://go/android-license-faq
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+// Build tool used to generate jarjar rules for all classes in a jar, except those that are
+// API, UnsupportedAppUsage or otherwise excluded.
+python_binary_host {
+    name: "jarjar-rules-generator",
+    srcs: [
+        "gen_jarjar.py",
+    ],
+    main: "gen_jarjar.py",
+    version: {
+        py2: {
+            enabled: false,
+        },
+        py3: {
+            enabled: true,
+        },
+    },
+    visibility: ["//packages/modules/Connectivity:__subpackages__"],
+}
+
+genrule_defaults {
+    name: "jarjar-rules-combine-defaults",
+    // Concat files with a line break in the middle
+    cmd: "for src in $(in); do cat $${src}; echo; done > $(out)",
+    defaults_visibility: ["//packages/modules/Connectivity:__subpackages__"],
+}
+
+java_library {
+    name: "jarjar-rules-generator-testjavalib",
+    srcs: ["testdata/java/**/*.java"],
+    visibility: ["//visibility:private"],
+}
+
+// TODO(b/233723405) - Remove this workaround.
+// Temporary work around of b/233723405. Using the module_lib stub directly
+// in the test causes it to sometimes get the dex jar and sometimes get the
+// classes jar due to b/233111644. Statically including it here instead
+// ensures that it will always get the classes jar.
+java_library {
+    name: "framework-connectivity.stubs.module_lib-for-test",
+    visibility: ["//visibility:private"],
+    static_libs: [
+        "framework-connectivity.stubs.module_lib",
+    ],
+    // Not strictly necessary but specified as this MUST not have generate
+    // a dex jar as that will break the tests.
+    compile_dex: false,
+}
+
+python_test_host {
+    name: "jarjar-rules-generator-test",
+    srcs: [
+        "gen_jarjar.py",
+        "gen_jarjar_test.py",
+    ],
+    data: [
+        "testdata/test-jarjar-excludes.txt",
+        "testdata/test-unsupportedappusage.txt",
+        ":framework-connectivity.stubs.module_lib-for-test",
+        ":jarjar-rules-generator-testjavalib",
+    ],
+    main: "gen_jarjar_test.py",
+    version: {
+        py2: {
+            enabled: false,
+        },
+        py3: {
+            enabled: true,
+        },
+    },
+}
diff --git a/tools/gen_jarjar.py b/tools/gen_jarjar.py
new file mode 100755
index 0000000..4c2cf54
--- /dev/null
+++ b/tools/gen_jarjar.py
@@ -0,0 +1,133 @@
+#
+# Copyright (C) 2022 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+""" This script generates jarjar rule files to add a jarjar prefix to all classes, except those
+that are API, unsupported API or otherwise excluded."""
+
+import argparse
+import io
+import re
+import subprocess
+from xml import sax
+from xml.sax.handler import ContentHandler
+from zipfile import ZipFile
+
+
+def parse_arguments(argv):
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '--jars', nargs='+',
+        help='Path to pre-jarjar JAR. Can be followed by multiple space-separated paths.')
+    parser.add_argument(
+        '--prefix', required=True,
+        help='Package prefix to use for jarjared classes, '
+             'for example "com.android.connectivity" (does not end with a dot).')
+    parser.add_argument(
+        '--output', required=True, help='Path to output jarjar rules file.')
+    parser.add_argument(
+        '--apistubs', nargs='*', default=[],
+        help='Path to API stubs jar. Classes that are API will not be jarjared. Can be followed by '
+             'multiple space-separated paths.')
+    parser.add_argument(
+        '--unsupportedapi', nargs='*', default=[],
+        help='Path to UnsupportedAppUsage hidden API .txt lists. '
+             'Classes that have UnsupportedAppUsage API will not be jarjared. Can be followed by '
+             'multiple space-separated paths.')
+    parser.add_argument(
+        '--excludes', nargs='*', default=[],
+        help='Path to files listing classes that should not be jarjared. Can be followed by '
+             'multiple space-separated paths. '
+             'Each file should contain one full-match regex per line. Empty lines or lines '
+             'starting with "#" are ignored.')
+    return parser.parse_args(argv)
+
+
+def _list_toplevel_jar_classes(jar):
+    """List all classes in a .class .jar file that are not inner classes."""
+    return {_get_toplevel_class(c) for c in _list_jar_classes(jar)}
+
+def _list_jar_classes(jar):
+    with ZipFile(jar, 'r') as zip:
+        files = zip.namelist()
+        assert 'classes.dex' not in files, f'Jar file {jar} is dexed, ' \
+                                           'expected an intermediate zip of .class files'
+        class_len = len('.class')
+        return [f.replace('/', '.')[:-class_len] for f in files
+                if f.endswith('.class') and not f.endswith('/package-info.class')]
+
+
+def _list_hiddenapi_classes(txt_file):
+    out = set()
+    with open(txt_file, 'r') as f:
+        for line in f:
+            if not line.strip():
+                continue
+            assert line.startswith('L') and ';' in line, f'Class name not recognized: {line}'
+            clazz = line.replace('/', '.').split(';')[0][1:]
+            out.add(_get_toplevel_class(clazz))
+    return out
+
+
+def _get_toplevel_class(clazz):
+    """Return the name of the toplevel (not an inner class) enclosing class of the given class."""
+    if '$' not in clazz:
+        return clazz
+    return clazz.split('$')[0]
+
+
+def _get_excludes(path):
+    out = []
+    with open(path, 'r') as f:
+        for line in f:
+            stripped = line.strip()
+            if not stripped or stripped.startswith('#'):
+                continue
+            out.append(re.compile(stripped))
+    return out
+
+
+def make_jarjar_rules(args):
+    excluded_classes = set()
+    for apistubs_file in args.apistubs:
+        excluded_classes.update(_list_toplevel_jar_classes(apistubs_file))
+
+    for unsupportedapi_file in args.unsupportedapi:
+        excluded_classes.update(_list_hiddenapi_classes(unsupportedapi_file))
+
+    exclude_regexes = []
+    for exclude_file in args.excludes:
+        exclude_regexes.extend(_get_excludes(exclude_file))
+
+    with open(args.output, 'w') as outfile:
+        for jar in args.jars:
+            jar_classes = _list_jar_classes(jar)
+            jar_classes.sort()
+            for clazz in jar_classes:
+                if (_get_toplevel_class(clazz) not in excluded_classes and
+                        not any(r.fullmatch(clazz) for r in exclude_regexes)):
+                    outfile.write(f'rule {clazz} {args.prefix}.@0\n')
+                    # Also include jarjar rules for unit tests of the class, so the package matches
+                    outfile.write(f'rule {clazz}Test {args.prefix}.@0\n')
+                    outfile.write(f'rule {clazz}Test$* {args.prefix}.@0\n')
+
+
+def _main():
+    # Pass in None to use argv
+    args = parse_arguments(None)
+    make_jarjar_rules(args)
+
+
+if __name__ == '__main__':
+    _main()
diff --git a/tools/gen_jarjar_test.py b/tools/gen_jarjar_test.py
new file mode 100644
index 0000000..8d8e82b
--- /dev/null
+++ b/tools/gen_jarjar_test.py
@@ -0,0 +1,57 @@
+#  Copyright (C) 2022 The Android Open Source Project
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+import gen_jarjar
+import unittest
+
+
+class TestGenJarjar(unittest.TestCase):
+    def test_gen_rules(self):
+        args = gen_jarjar.parse_arguments([
+            "--jars", "jarjar-rules-generator-testjavalib.jar",
+            "--prefix", "jarjar.prefix",
+            "--output", "test-output-rules.txt",
+            "--apistubs", "framework-connectivity.stubs.module_lib.jar",
+            "--unsupportedapi", "testdata/test-unsupportedappusage.txt",
+            "--excludes", "testdata/test-jarjar-excludes.txt",
+        ])
+        gen_jarjar.make_jarjar_rules(args)
+
+        with open(args.output) as out:
+            lines = out.readlines()
+
+        self.assertListEqual([
+            'rule test.utils.TestUtilClass jarjar.prefix.@0\n',
+            'rule test.utils.TestUtilClassTest jarjar.prefix.@0\n',
+            'rule test.utils.TestUtilClassTest$* jarjar.prefix.@0\n',
+            'rule test.utils.TestUtilClass$TestInnerClass jarjar.prefix.@0\n',
+            'rule test.utils.TestUtilClass$TestInnerClassTest jarjar.prefix.@0\n',
+            'rule test.utils.TestUtilClass$TestInnerClassTest$* jarjar.prefix.@0\n'], lines)
+
+
+if __name__ == '__main__':
+    # Need verbosity=2 for the test results parser to find results
+    unittest.main(verbosity=2)
diff --git a/tools/testdata/java/android/net/LinkProperties.java b/tools/testdata/java/android/net/LinkProperties.java
new file mode 100644
index 0000000..bdca377
--- /dev/null
+++ b/tools/testdata/java/android/net/LinkProperties.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+/**
+ * Test class with a name matching a public API.
+ */
+public class LinkProperties {
+}
diff --git a/tools/testdata/java/test/jarjarexcluded/JarjarExcludedClass.java b/tools/testdata/java/test/jarjarexcluded/JarjarExcludedClass.java
new file mode 100644
index 0000000..7e3bee1
--- /dev/null
+++ b/tools/testdata/java/test/jarjarexcluded/JarjarExcludedClass.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test.jarjarexcluded;
+
+/**
+ * Test class that is excluded from jarjar.
+ */
+public class JarjarExcludedClass {
+}
diff --git a/tools/testdata/java/test/unsupportedappusage/TestUnsupportedAppUsageClass.java b/tools/testdata/java/test/unsupportedappusage/TestUnsupportedAppUsageClass.java
new file mode 100644
index 0000000..9d32296
--- /dev/null
+++ b/tools/testdata/java/test/unsupportedappusage/TestUnsupportedAppUsageClass.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test.unsupportedappusage;
+
+public class TestUnsupportedAppUsageClass {
+    public void testMethod() {}
+}
diff --git a/tools/testdata/java/test/utils/TestUtilClass.java b/tools/testdata/java/test/utils/TestUtilClass.java
new file mode 100644
index 0000000..2162e45
--- /dev/null
+++ b/tools/testdata/java/test/utils/TestUtilClass.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test.utils;
+
+/**
+ * Sample class to test jarjar rules.
+ */
+public class TestUtilClass {
+    public static class TestInnerClass {}
+}
diff --git a/tools/testdata/test-jarjar-excludes.txt b/tools/testdata/test-jarjar-excludes.txt
new file mode 100644
index 0000000..35d97a2
--- /dev/null
+++ b/tools/testdata/test-jarjar-excludes.txt
@@ -0,0 +1,3 @@
+# Test file for excluded classes
+test\.jarj.rexcluded\.JarjarExcludedCla.s
+test\.jarjarexcluded\.JarjarExcludedClass\$TestInnerCl.ss
diff --git a/tools/testdata/test-unsupportedappusage.txt b/tools/testdata/test-unsupportedappusage.txt
new file mode 100644
index 0000000..331eff9
--- /dev/null
+++ b/tools/testdata/test-unsupportedappusage.txt
@@ -0,0 +1 @@
+Ltest/unsupportedappusage/TestUnsupportedAppUsageClass;->testMethod()V
\ No newline at end of file