Merge changes from topic "fixTetheringRevert" into main

* changes:
  Validate packageName with AppOpsManager#checkPackage
  Revert^2 "Add UID and package name to TetheringRequest"
diff --git a/bpf/loader/NetBpfLoad.cpp b/bpf/loader/NetBpfLoad.cpp
index 9a049c7..c2a1d6e 100644
--- a/bpf/loader/NetBpfLoad.cpp
+++ b/bpf/loader/NetBpfLoad.cpp
@@ -1288,6 +1288,8 @@
 
 #define APEX_MOUNT_POINT "/apex/com.android.tethering"
 const char * const platformBpfLoader = "/system/bin/bpfloader";
+const char *const uprobestatsBpfLoader =
+    "/apex/com.android.uprobestats/bin/uprobestatsbpfload";
 
 static int logTetheringApexVersion(void) {
     char * found_blockdev = NULL;
@@ -1657,8 +1659,17 @@
     }
 
     // unreachable before U QPR3
-    ALOGI("done, transferring control to platform bpfloader.");
+    {
+      ALOGI("done, transferring control to uprobestatsbpfload.");
+      const char *args[] = {
+          uprobestatsBpfLoader,
+          NULL,
+      };
+      execve(args[0], (char **)args, envp);
+    }
 
+    ALOGI("unable to execute uprobestatsbpfload, transferring control to "
+          "platform bpfloader.");
     // platform BpfLoader *needs* to run as root
     const char * args[] = { platformBpfLoader, NULL, };
     execve(args[0], (char**)args, envp);
diff --git a/bpf/netd/BpfHandler.cpp b/bpf/netd/BpfHandler.cpp
index 8e4c2c6..50e0329 100644
--- a/bpf/netd/BpfHandler.cpp
+++ b/bpf/netd/BpfHandler.cpp
@@ -120,18 +120,22 @@
     }
 
     if (modules::sdklevel::IsAtLeastV()) {
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_CONNECT4_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_INET4_CONNECT));
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_CONNECT6_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_INET6_CONNECT));
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP4_RECVMSG_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_UDP4_RECVMSG));
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP6_RECVMSG_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_UDP6_RECVMSG));
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP4_SENDMSG_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_UDP4_SENDMSG));
-        RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP6_SENDMSG_PROG_PATH,
-                                    cg_fd, BPF_CGROUP_UDP6_SENDMSG));
+        // V requires 4.19+, so technically this 2nd 'if' is not required, but it
+        // doesn't hurt us to try to support AOSP forks that try to support older kernels.
+        if (bpf::isAtLeastKernelVersion(4, 19, 0)) {
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_CONNECT4_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_INET4_CONNECT));
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_CONNECT6_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_INET6_CONNECT));
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP4_RECVMSG_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_UDP4_RECVMSG));
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP6_RECVMSG_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_UDP6_RECVMSG));
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP4_SENDMSG_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_UDP4_SENDMSG));
+            RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_UDP6_SENDMSG_PROG_PATH,
+                                        cg_fd, BPF_CGROUP_UDP6_SENDMSG));
+        }
 
         if (bpf::isAtLeastKernelVersion(5, 4, 0)) {
             RETURN_IF_NOT_OK(attachProgramToCgroup(CGROUP_GETSOCKOPT_PROG_PATH,
@@ -161,12 +165,16 @@
     }
 
     if (modules::sdklevel::IsAtLeastV()) {
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_INET4_CONNECT) <= 0) abort();
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_INET6_CONNECT) <= 0) abort();
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP4_RECVMSG) <= 0) abort();
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP6_RECVMSG) <= 0) abort();
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP4_SENDMSG) <= 0) abort();
-        if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP6_SENDMSG) <= 0) abort();
+        // V requires 4.19+, so technically this 2nd 'if' is not required, but it
+        // doesn't hurt us to try to support AOSP forks that try to support older kernels.
+        if (bpf::isAtLeastKernelVersion(4, 19, 0)) {
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_INET4_CONNECT) <= 0) abort();
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_INET6_CONNECT) <= 0) abort();
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP4_RECVMSG) <= 0) abort();
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP6_RECVMSG) <= 0) abort();
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP4_SENDMSG) <= 0) abort();
+            if (bpf::queryProgram(cg_fd, BPF_CGROUP_UDP6_SENDMSG) <= 0) abort();
+        }
 
         if (bpf::isAtLeastKernelVersion(5, 4, 0)) {
             if (bpf::queryProgram(cg_fd, BPF_CGROUP_GETSOCKOPT) <= 0) abort();
diff --git a/bpf/progs/netd.c b/bpf/progs/netd.c
index cbe856d..ed0eed5 100644
--- a/bpf/progs/netd.c
+++ b/bpf/progs/netd.c
@@ -709,32 +709,32 @@
     return block_port(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("connect4/inet4_connect", AID_ROOT, AID_ROOT, inet4_connect, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("connect4/inet4_connect", AID_ROOT, AID_ROOT, inet4_connect, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("connect6/inet6_connect", AID_ROOT, AID_ROOT, inet6_connect, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("connect6/inet6_connect", AID_ROOT, AID_ROOT, inet6_connect, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("recvmsg4/udp4_recvmsg", AID_ROOT, AID_ROOT, udp4_recvmsg, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("recvmsg4/udp4_recvmsg", AID_ROOT, AID_ROOT, udp4_recvmsg, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("recvmsg6/udp6_recvmsg", AID_ROOT, AID_ROOT, udp6_recvmsg, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("recvmsg6/udp6_recvmsg", AID_ROOT, AID_ROOT, udp6_recvmsg, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("sendmsg4/udp4_sendmsg", AID_ROOT, AID_ROOT, udp4_sendmsg, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("sendmsg4/udp4_sendmsg", AID_ROOT, AID_ROOT, udp4_sendmsg, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
 
-DEFINE_NETD_V_BPF_PROG_KVER("sendmsg6/udp6_sendmsg", AID_ROOT, AID_ROOT, udp6_sendmsg, KVER_4_14)
+DEFINE_NETD_V_BPF_PROG_KVER("sendmsg6/udp6_sendmsg", AID_ROOT, AID_ROOT, udp6_sendmsg, KVER_4_19)
 (struct bpf_sock_addr *ctx) {
     return check_localhost(ctx);
 }
diff --git a/framework-t/src/android/net/TrafficStats.java b/framework-t/src/android/net/TrafficStats.java
index 1294b3e..caf3152 100644
--- a/framework-t/src/android/net/TrafficStats.java
+++ b/framework-t/src/android/net/TrafficStats.java
@@ -17,8 +17,6 @@
 package android.net;
 
 import static android.annotation.SystemApi.Client.MODULE_LIBRARIES;
-import static android.net.NetworkStats.UID_ALL;
-import static android.os.Process.SYSTEM_UID;
 
 import static com.android.internal.annotations.VisibleForTesting.Visibility.PRIVATE;
 
@@ -188,8 +186,6 @@
     private static INetworkStatsService sStatsService;
     @GuardedBy("TrafficStats.class")
     private static INetworkStatsService sStatsServiceForTest = null;
-    @GuardedBy("TrafficStats.class")
-    private static int sMyUidForTest = UID_ALL;
 
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 130143562)
     private synchronized static INetworkStatsService getStatsService() {
@@ -202,12 +198,7 @@
     }
 
     /** @hide */
-    protected static int getMyUid() {
-        synchronized (TrafficStats.class) {
-            if (sMyUidForTest != UID_ALL) {
-                return sMyUidForTest;
-            }
-        }
+    private static int getMyUid() {
         return android.os.Process.myUid();
     }
 
@@ -224,18 +215,6 @@
     }
 
     /**
-     * Set myUid for test, or UID_ALL to reset.
-     *
-     * @hide
-     */
-    @VisibleForTesting(visibility = PRIVATE)
-    public static void setMyUidForTest(int myUid) {
-        synchronized (TrafficStats.class) {
-            sMyUidForTest = myUid;
-        }
-    }
-
-    /**
      * Snapshot of {@link NetworkStats} when the currently active profiling
      * session started, or {@code null} if no session active.
      *
@@ -289,8 +268,8 @@
 
     private static class SocketTagger extends dalvik.system.SocketTagger {
 
-        // TODO: set to false
-        private static final boolean LOGD = true;
+        // Enable log with `setprop log.tag.TrafficStats DEBUG` and restart the module.
+        private static final boolean LOGD = Log.isLoggable(TAG, Log.DEBUG);
 
         SocketTagger() {
         }
@@ -1006,13 +985,6 @@
 
     /** @hide */
     public static long getUidStats(int uid, int type) {
-        // Perform a quick check on the UID to avoid unnecessary work.
-        // This mirrors a similar check on the service side, but is primarily for
-        // efficiency rather than security, as user-space checks can be bypassed.
-        final int myUid = getMyUid();
-        if (!isEntryValueTypeValid(type) || (myUid != SYSTEM_UID && myUid != uid)) {
-            return UNSUPPORTED;
-        }
         final StatsResult stats;
         try {
             stats = getStatsService().getUidStats(uid);
@@ -1024,9 +996,6 @@
 
     /** @hide */
     public static long getTotalStats(int type) {
-        if (!isEntryValueTypeValid(type)) {
-            return UNSUPPORTED;
-        }
         final StatsResult stats;
         try {
             stats = getStatsService().getTotalStats();
@@ -1038,9 +1007,6 @@
 
     /** @hide */
     public static long getIfaceStats(String iface, int type) {
-        if (!isEntryValueTypeValid(type)) {
-            return UNSUPPORTED;
-        }
         final StatsResult stats;
         try {
             stats = getStatsService().getIfaceStats(iface);
diff --git a/service-t/src/com/android/server/net/TrafficStatsRateLimitCache.java b/service-t/src/com/android/server/net/TrafficStatsRateLimitCache.java
index ca97d07..667aad1 100644
--- a/service-t/src/com/android/server/net/TrafficStatsRateLimitCache.java
+++ b/service-t/src/com/android/server/net/TrafficStatsRateLimitCache.java
@@ -19,9 +19,8 @@
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.net.NetworkStats;
-import android.util.LruCache;
 
-import com.android.internal.annotations.GuardedBy;
+import com.android.net.module.util.LruCacheWithExpiry;
 
 import java.time.Clock;
 import java.util.Objects;
@@ -31,9 +30,8 @@
  * A thread-safe cache for storing and retrieving {@link NetworkStats.Entry} objects,
  * with an adjustable expiry duration to manage data freshness.
  */
-class TrafficStatsRateLimitCache {
-    private final Clock mClock;
-    private final long mExpiryDurationMs;
+class TrafficStatsRateLimitCache extends
+        LruCacheWithExpiry<TrafficStatsRateLimitCache.TrafficStatsCacheKey, NetworkStats.Entry> {
 
     /**
      * Constructs a new {@link TrafficStatsRateLimitCache} with the specified expiry duration.
@@ -43,19 +41,17 @@
      * @param maxSize Maximum number of entries.
      */
     TrafficStatsRateLimitCache(@NonNull Clock clock, long expiryDurationMs, int maxSize) {
-        mClock = clock;
-        mExpiryDurationMs = expiryDurationMs;
-        mMap = new LruCache<>(maxSize);
+        super(clock, expiryDurationMs, maxSize, it -> !it.isEmpty());
     }
 
-    private static class TrafficStatsCacheKey {
+    public static class TrafficStatsCacheKey {
         @Nullable
-        public final String iface;
-        public final int uid;
+        private final String mIface;
+        private final int mUid;
 
         TrafficStatsCacheKey(@Nullable String iface, int uid) {
-            this.iface = iface;
-            this.uid = uid;
+            this.mIface = iface;
+            this.mUid = uid;
         }
 
         @Override
@@ -63,29 +59,15 @@
             if (this == o) return true;
             if (!(o instanceof TrafficStatsCacheKey)) return false;
             TrafficStatsCacheKey that = (TrafficStatsCacheKey) o;
-            return uid == that.uid && Objects.equals(iface, that.iface);
+            return mUid == that.mUid && Objects.equals(mIface, that.mIface);
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(iface, uid);
+            return Objects.hash(mIface, mUid);
         }
     }
 
-    private static class TrafficStatsCacheValue {
-        public final long timestamp;
-        @NonNull
-        public final NetworkStats.Entry entry;
-
-        TrafficStatsCacheValue(long timestamp, NetworkStats.Entry entry) {
-            this.timestamp = timestamp;
-            this.entry = entry;
-        }
-    }
-
-    @GuardedBy("mMap")
-    private final LruCache<TrafficStatsCacheKey, TrafficStatsCacheValue> mMap;
-
     /**
      * Retrieves a {@link NetworkStats.Entry} from the cache, associated with the given key.
      *
@@ -95,16 +77,7 @@
      */
     @Nullable
     NetworkStats.Entry get(String iface, int uid) {
-        final TrafficStatsCacheKey key = new TrafficStatsCacheKey(iface, uid);
-        synchronized (mMap) { // Synchronize for thread-safety
-            final TrafficStatsCacheValue value = mMap.get(key);
-            if (value != null && !isExpired(value.timestamp)) {
-                return value.entry;
-            } else {
-                mMap.remove(key); // Remove expired entries
-                return null;
-            }
-        }
+        return super.get(new TrafficStatsCacheKey(iface, uid));
     }
 
     /**
@@ -122,19 +95,7 @@
     @Nullable
     NetworkStats.Entry getOrCompute(String iface, int uid,
             @NonNull Supplier<NetworkStats.Entry> supplier) {
-        synchronized (mMap) {
-            final NetworkStats.Entry cachedValue = get(iface, uid);
-            if (cachedValue != null) {
-                return cachedValue;
-            }
-
-            // Entry not found or expired, compute it
-            final NetworkStats.Entry computedEntry = supplier.get();
-            if (computedEntry != null && !computedEntry.isEmpty()) {
-                put(iface, uid, computedEntry);
-            }
-            return computedEntry;
-        }
+        return super.getOrCompute(new TrafficStatsCacheKey(iface, uid), supplier);
     }
 
     /**
@@ -145,23 +106,7 @@
      * @param entry The {@link NetworkStats.Entry} to store in the cache.
      */
     void put(String iface, int uid, @NonNull final NetworkStats.Entry entry) {
-        Objects.requireNonNull(entry);
-        final TrafficStatsCacheKey key = new TrafficStatsCacheKey(iface, uid);
-        synchronized (mMap) { // Synchronize for thread-safety
-            mMap.put(key, new TrafficStatsCacheValue(mClock.millis(), entry));
-        }
+        super.put(new TrafficStatsCacheKey(iface, uid), entry);
     }
 
-    /**
-     * Clear the cache.
-     */
-    void clear() {
-        synchronized (mMap) {
-            mMap.evictAll();
-        }
-    }
-
-    private boolean isExpired(long timestamp) {
-        return mClock.millis() > timestamp + mExpiryDurationMs;
-    }
 }
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index e503312..9015434 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -121,6 +121,7 @@
 import static android.net.connectivity.ConnectivityCompatChanges.NETWORK_BLOCKED_WITHOUT_INTERNET_PERMISSION;
 import static android.os.Process.INVALID_UID;
 import static android.os.Process.VPN_UID;
+import static android.provider.DeviceConfig.NAMESPACE_TETHERING;
 import static android.system.OsConstants.ETH_P_ALL;
 import static android.system.OsConstants.IPPROTO_TCP;
 import static android.system.OsConstants.IPPROTO_UDP;
@@ -145,10 +146,12 @@
 import static com.android.net.module.util.PermissionUtils.enforceNetworkStackPermissionOr;
 import static com.android.net.module.util.PermissionUtils.hasAnyPermissionOf;
 import static com.android.server.ConnectivityStatsLog.CONNECTIVITY_STATE_SAMPLE;
+import static com.android.server.connectivity.ConnectivityFlags.CELLULAR_DATA_INACTIVITY_TIMEOUT;
 import static com.android.server.connectivity.ConnectivityFlags.DELAY_DESTROY_SOCKETS;
 import static com.android.server.connectivity.ConnectivityFlags.INGRESS_TO_VPN_ADDRESS_FILTERING;
 import static com.android.server.connectivity.ConnectivityFlags.QUEUE_CALLBACKS_FOR_FROZEN_APPS;
 import static com.android.server.connectivity.ConnectivityFlags.REQUEST_RESTRICTED_WIFI;
+import static com.android.server.connectivity.ConnectivityFlags.WIFI_DATA_INACTIVITY_TIMEOUT;
 
 import android.Manifest;
 import android.annotation.CheckResult;
@@ -1610,6 +1613,18 @@
                     connectivityServiceInternalHandler);
         }
 
+        /** Returns the data inactivity timeout to be used for cellular networks */
+        public int getDefaultCellularDataInactivityTimeout() {
+            return DeviceConfigUtils.getDeviceConfigPropertyInt(NAMESPACE_TETHERING,
+                    CELLULAR_DATA_INACTIVITY_TIMEOUT, 10);
+        }
+
+        /** Returns the data inactivity timeout to be used for WiFi networks */
+        public int getDefaultWifiDataInactivityTimeout() {
+            return DeviceConfigUtils.getDeviceConfigPropertyInt(NAMESPACE_TETHERING,
+                    WIFI_DATA_INACTIVITY_TIMEOUT, 15);
+        }
+
         /**
          * @see DeviceConfigUtils#isTetheringFeatureEnabled
          */
@@ -1958,8 +1973,13 @@
         // But reading the trunk stable flags from mainline modules is not supported yet.
         // So enabling this feature on V+ release.
         mTrackMultiNetworkActivities = mDeps.isAtLeastV();
+        final int defaultCellularDataInactivityTimeout =
+                mDeps.getDefaultCellularDataInactivityTimeout();
+        final int defaultWifiDataInactivityTimeout =
+                mDeps.getDefaultWifiDataInactivityTimeout();
         mNetworkActivityTracker = new LegacyNetworkActivityTracker(mContext, mNetd, mHandler,
-                mTrackMultiNetworkActivities);
+                mTrackMultiNetworkActivities, defaultCellularDataInactivityTimeout,
+                defaultWifiDataInactivityTimeout);
 
         final NetdCallback netdCallback = new NetdCallback();
         try {
@@ -13027,6 +13047,8 @@
         // Key is netId. Value is configured idle timer information.
         private final SparseArray<IdleTimerParams> mActiveIdleTimers = new SparseArray<>();
         private final boolean mTrackMultiNetworkActivities;
+        private final int mDefaultCellularDataInactivityTimeout;
+        private final int mDefaultWifiDataInactivityTimeout;
         // Store netIds of Wi-Fi networks whose idletimers report that they are active
         private final Set<Integer> mActiveWifiNetworks = new ArraySet<>();
         // Store netIds of cellular networks whose idletimers report that they are active
@@ -13043,11 +13065,14 @@
         }
 
         LegacyNetworkActivityTracker(@NonNull Context context, @NonNull INetd netd,
-                @NonNull Handler handler, boolean trackMultiNetworkActivities) {
+                @NonNull Handler handler, boolean trackMultiNetworkActivities,
+                int defaultCellularDataInactivityTimeout, int defaultWifiDataInactivityTimeout) {
             mContext = context;
             mNetd = netd;
             mHandler = handler;
             mTrackMultiNetworkActivities = trackMultiNetworkActivities;
+            mDefaultCellularDataInactivityTimeout = defaultCellularDataInactivityTimeout;
+            mDefaultWifiDataInactivityTimeout = defaultWifiDataInactivityTimeout;
         }
 
         private void ensureRunningOnConnectivityServiceThread() {
@@ -13247,13 +13272,13 @@
                     NetworkCapabilities.TRANSPORT_CELLULAR)) {
                 timeout = Settings.Global.getInt(mContext.getContentResolver(),
                         ConnectivitySettingsManager.DATA_ACTIVITY_TIMEOUT_MOBILE,
-                        10);
+                        mDefaultCellularDataInactivityTimeout);
                 type = NetworkCapabilities.TRANSPORT_CELLULAR;
             } else if (networkAgent.networkCapabilities.hasTransport(
                     NetworkCapabilities.TRANSPORT_WIFI)) {
                 timeout = Settings.Global.getInt(mContext.getContentResolver(),
                         ConnectivitySettingsManager.DATA_ACTIVITY_TIMEOUT_WIFI,
-                        15);
+                        mDefaultWifiDataInactivityTimeout);
                 type = NetworkCapabilities.TRANSPORT_WIFI;
             } else {
                 return false; // do not track any other networks
@@ -13377,6 +13402,12 @@
 
         public void dump(IndentingPrintWriter pw) {
             pw.print("mTrackMultiNetworkActivities="); pw.println(mTrackMultiNetworkActivities);
+
+            pw.print("mDefaultCellularDataInactivityTimeout=");
+            pw.println(mDefaultCellularDataInactivityTimeout);
+            pw.print("mDefaultWifiDataInactivityTimeout=");
+            pw.println(mDefaultWifiDataInactivityTimeout);
+
             pw.print("mIsDefaultNetworkActive="); pw.println(mIsDefaultNetworkActive);
             pw.print("mDefaultNetwork="); pw.println(mDefaultNetwork);
             pw.println("Idle timers:");
diff --git a/service/src/com/android/server/connectivity/ConnectivityFlags.java b/service/src/com/android/server/connectivity/ConnectivityFlags.java
index df87316..93335f1 100644
--- a/service/src/com/android/server/connectivity/ConnectivityFlags.java
+++ b/service/src/com/android/server/connectivity/ConnectivityFlags.java
@@ -44,6 +44,11 @@
 
     public static final String BACKGROUND_FIREWALL_CHAIN = "background_firewall_chain";
 
+    public static final String CELLULAR_DATA_INACTIVITY_TIMEOUT =
+            "cellular_data_inactivity_timeout";
+
+    public static final String WIFI_DATA_INACTIVITY_TIMEOUT = "wifi_data_inactivity_timeout";
+
     public static final String DELAY_DESTROY_SOCKETS = "delay_destroy_sockets";
 
     public static final String USE_DECLARED_METHODS_FOR_CALLBACKS =
diff --git a/staticlibs/Android.bp b/staticlibs/Android.bp
index a825b87..f484027 100644
--- a/staticlibs/Android.bp
+++ b/staticlibs/Android.bp
@@ -671,11 +671,12 @@
     visibility: ["//visibility:private"],
 }
 
+// Sources outside of com.android.net.module.util should not be added because many modules depend on
+// them and need jarjar rules
 filegroup {
     name: "net-utils-all-srcs",
     srcs: [
         "device/**/*.java",
-        ":framework-connectivity-shared-srcs",
         ":net-utils-framework-common-srcs",
     ],
     visibility: ["//visibility:private"],
diff --git a/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java b/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
index 7fcbd4e..bb95585 100644
--- a/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
+++ b/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
@@ -35,12 +35,12 @@
 import android.net.NetworkCapabilities;
 import android.os.RemoteException;
 import android.util.ArrayMap;
-import android.util.IndentingPrintWriter;
 
 import androidx.annotation.Nullable;
 
 import com.android.internal.annotations.VisibleForTesting;
 
+import java.io.PrintWriter;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.util.ArrayList;
@@ -459,34 +459,27 @@
         }
     }
 
-    // TODO: dump PrivateAddressCoordinator when dumping RoutingCoordinatorService.
-    void dump(final IndentingPrintWriter pw) {
+    // TODO: dump PrivateAddressCoordinator when dumping RoutingCoordinatorService and apply
+    // indentation.
+    void dump(final PrintWriter pw) {
         pw.println("mTetheringPrefixes:");
-        pw.increaseIndent();
         for (IpPrefix prefix : mTetheringPrefixes) {
             pw.println(prefix);
         }
-        pw.decreaseIndent();
 
         pw.println("mUpstreamPrefixMap:");
-        pw.increaseIndent();
         for (int i = 0; i < mUpstreamPrefixMap.size(); i++) {
             pw.println(mUpstreamPrefixMap.keyAt(i) + " - " + mUpstreamPrefixMap.valueAt(i));
         }
-        pw.decreaseIndent();
 
         pw.println("mDownstreams:");
-        pw.increaseIndent();
         for (LinkAddress downstream : mDownstreams.values()) {
             pw.println(downstream);
         }
-        pw.decreaseIndent();
 
         pw.println("mCachedAddresses:");
-        pw.increaseIndent();
         for (int i = 0; i < mCachedAddresses.size(); i++) {
             pw.println(mCachedAddresses.keyAt(i) + " - " + mCachedAddresses.valueAt(i));
         }
-        pw.decreaseIndent();
     }
 }
diff --git a/staticlibs/framework/com/android/net/module/util/LruCacheWithExpiry.java b/staticlibs/framework/com/android/net/module/util/LruCacheWithExpiry.java
new file mode 100644
index 0000000..80088b9
--- /dev/null
+++ b/staticlibs/framework/com/android/net/module/util/LruCacheWithExpiry.java
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2024 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;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.util.LruCache;
+
+import com.android.internal.annotations.GuardedBy;
+
+import java.time.Clock;
+import java.util.Objects;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+
+/**
+ * An LRU cache that stores key-value pairs with an expiry time.
+ *
+ * <p>This cache uses an {@link LruCache} to store entries and evicts the least
+ * recently used entries when the cache reaches its maximum capacity. It also
+ * supports an expiry time for each entry, allowing entries to be automatically
+ * removed from the cache after a certain duration.
+ *
+ * @param <K> The type of keys used to identify cached entries.
+ * @param <V> The type of values stored in the cache.
+ *
+ * @hide
+ */
+public class LruCacheWithExpiry<K, V> {
+    private final Clock mClock;
+    private final long mExpiryDurationMs;
+    @GuardedBy("mMap")
+    private final LruCache<K, CacheValue<V>> mMap;
+    private final Predicate<V> mShouldCacheValue;
+
+    /**
+     * Constructs a new {@link LruCacheWithExpiry} with the specified parameters.
+     *
+     * @param clock            The {@link Clock} to use for determining timestamps.
+     * @param expiryDurationMs The expiry duration for cached entries in milliseconds.
+     * @param maxSize          The maximum number of entries to hold in the cache.
+     * @param shouldCacheValue A {@link Predicate} that determines whether a given value should be
+     *                         cached. This can be used to filter out certain values from being
+     *                         stored in the cache.
+     */
+    public LruCacheWithExpiry(@NonNull Clock clock, long expiryDurationMs, int maxSize,
+            Predicate<V> shouldCacheValue) {
+        mClock = clock;
+        mExpiryDurationMs = expiryDurationMs;
+        mMap = new LruCache<>(maxSize);
+        mShouldCacheValue = shouldCacheValue;
+    }
+
+    /**
+     * Retrieves a value from the cache, associated with the given key.
+     *
+     * @param key The key to look up in the cache.
+     * @return The cached value, or {@code null} if not found or expired.
+     */
+    @Nullable
+    public V get(@NonNull K key) {
+        synchronized (mMap) {
+            final CacheValue<V> value = mMap.get(key);
+            if (value != null && !isExpired(value.timestamp)) {
+                return value.entry;
+            } else {
+                mMap.remove(key); // Remove expired entries
+                return null;
+            }
+        }
+    }
+
+    /**
+     * Retrieves a value from the cache, associated with the given key.
+     * If the entry is not found in the cache or has expired, computes it using the provided
+     * {@code supplier} and stores the result in the cache.
+     *
+     * @param key      The key to look up in the cache.
+     * @param supplier The {@link Supplier} to compute the value if not found or expired.
+     * @return The cached or computed value, or {@code null} if the {@code supplier} returns null.
+     */
+    @Nullable
+    public V getOrCompute(@NonNull K key, @NonNull Supplier<V> supplier) {
+        synchronized (mMap) {
+            final V cachedValue = get(key);
+            if (cachedValue != null) {
+                return cachedValue;
+            }
+
+            // Entry not found or expired, compute it
+            final V computedValue = supplier.get();
+            if (computedValue != null && mShouldCacheValue.test(computedValue)) {
+                put(key, computedValue);
+            }
+            return computedValue;
+        }
+    }
+
+    /**
+     * Stores a value in the cache, associated with the given key.
+     *
+     * @param key   The key to associate with the value.
+     * @param value The value to store in the cache.
+     */
+    public void put(@NonNull K key, @NonNull V value) {
+        Objects.requireNonNull(value);
+        synchronized (mMap) {
+            mMap.put(key, new CacheValue<>(mClock.millis(), value));
+        }
+    }
+
+    /**
+     * Clear the cache.
+     */
+    public void clear() {
+        synchronized (mMap) {
+            mMap.evictAll();
+        }
+    }
+
+    private boolean isExpired(long timestamp) {
+        return mClock.millis() > timestamp + mExpiryDurationMs;
+    }
+
+    private static class CacheValue<V> {
+        public final long timestamp;
+        @NonNull
+        public final V entry;
+
+        CacheValue(long timestamp, V entry) {
+            this.timestamp = timestamp;
+            this.entry = entry;
+        }
+    }
+}
diff --git a/tests/cts/net/Android.bp b/tests/cts/net/Android.bp
index a5ad7f2..9e57f69 100644
--- a/tests/cts/net/Android.bp
+++ b/tests/cts/net/Android.bp
@@ -70,6 +70,14 @@
         ":ConnectivityTestPreparer",
         ":CtsCarrierServicePackage",
     ],
+    errorprone: {
+        enabled: true,
+        // Error-prone checking only warns of problems when building. To make the build fail with
+        // these errors, list the specific error-prone problems below.
+        javacflags: [
+            "-Xep:NullablePrimitive:ERROR",
+        ],
+    },
 }
 
 // Networking CTS tests for development and release. These tests always target the platform SDK
diff --git a/tests/cts/net/AndroidTestTemplate.xml b/tests/cts/net/AndroidTestTemplate.xml
index 7590a2b..965d1f6 100644
--- a/tests/cts/net/AndroidTestTemplate.xml
+++ b/tests/cts/net/AndroidTestTemplate.xml
@@ -19,6 +19,7 @@
     <option name="config-descriptor:metadata" key="parameter" value="instant_app" />
     <option name="config-descriptor:metadata" key="parameter" value="not_multi_abi" />
     <option name="config-descriptor:metadata" key="parameter" value="secondary_user" />
+    <option name="config-descriptor:metadata" key="parameter" value="secondary_user_on_secondary_display" />
 
     <option name="config-descriptor:metadata" key="mainline-param" value="CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk+com.google.android.resolv.apex+com.google.android.tethering.apex" />
     <option name="config-descriptor:metadata" key="mainline-param" value="CaptivePortalLoginGoogle.apk+NetworkStackGoogle.apk" />
diff --git a/tests/cts/netpermission/internetpermission/Android.bp b/tests/cts/netpermission/internetpermission/Android.bp
index e0424ac..71d2b6e 100644
--- a/tests/cts/netpermission/internetpermission/Android.bp
+++ b/tests/cts/netpermission/internetpermission/Android.bp
@@ -32,4 +32,7 @@
     ],
     host_required: ["net-tests-utils-host-common"],
     sdk_version: "test_current",
+    data: [
+        ":ConnectivityTestPreparer",
+    ],
 }
diff --git a/tests/cts/netpermission/internetpermission/AndroidTest.xml b/tests/cts/netpermission/internetpermission/AndroidTest.xml
index ad9a731..13deb82 100644
--- a/tests/cts/netpermission/internetpermission/AndroidTest.xml
+++ b/tests/cts/netpermission/internetpermission/AndroidTest.xml
@@ -20,6 +20,7 @@
     <option name="config-descriptor:metadata" key="parameter" value="instant_app" />
     <option name="config-descriptor:metadata" key="parameter" value="not_multi_abi" />
     <option name="config-descriptor:metadata" key="parameter" value="secondary_user" />
+    <option name="config-descriptor:metadata" key="parameter" value="secondary_user_on_secondary_display" />
     <option name="not-shardable" value="true" />
     <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
         <option name="cleanup-apks" value="true" />
diff --git a/tests/cts/netpermission/updatestatspermission/Android.bp b/tests/cts/netpermission/updatestatspermission/Android.bp
index 689ce74..b324dc8 100644
--- a/tests/cts/netpermission/updatestatspermission/Android.bp
+++ b/tests/cts/netpermission/updatestatspermission/Android.bp
@@ -36,5 +36,6 @@
         "cts",
         "general-tests",
     ],
+    data: [":ConnectivityTestPreparer"],
     host_required: ["net-tests-utils-host-common"],
 }
diff --git a/tests/unit/java/android/net/TrafficStatsTest.kt b/tests/unit/java/android/net/TrafficStatsTest.kt
deleted file mode 100644
index 6e8f3db..0000000
--- a/tests/unit/java/android/net/TrafficStatsTest.kt
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright (C) 2024 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 android.net.NetworkStats.UID_ALL
-import android.net.TrafficStats.UNSUPPORTED
-import android.net.netstats.StatsResult
-import android.os.Build
-import android.os.Process.SYSTEM_UID
-import com.android.testutils.DevSdkIgnoreRule
-import com.android.testutils.DevSdkIgnoreRunner
-import org.junit.After
-import org.junit.Assert.assertEquals
-import org.junit.Before
-import org.junit.Test
-import org.junit.runner.RunWith
-import org.mockito.ArgumentMatchers.anyInt
-import org.mockito.Mockito.doReturn
-import org.mockito.Mockito.mock
-import org.mockito.Mockito.never
-import org.mockito.Mockito.verify
-
-@RunWith(DevSdkIgnoreRunner::class)
-@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
-class TrafficStatsTest {
-    private val binder = mock(INetworkStatsService::class.java)
-    private val myUid = android.os.Process.myUid()
-    private val notMyUid = myUid + 1
-    private val mockSystemUidStatsResult = StatsResult(1L, 2L, 3L, 4L)
-    private val mockMyUidStatsResult = StatsResult(5L, 6L, 7L, 8L)
-    private val mockNotMyUidStatsResult = StatsResult(9L, 10L, 11L, 12L)
-    private val unsupportedStatsResult =
-            StatsResult(UNSUPPORTED.toLong(), UNSUPPORTED.toLong(),
-                    UNSUPPORTED.toLong(), UNSUPPORTED.toLong())
-
-    @Before
-    fun setUp() {
-        TrafficStats.setServiceForTest(binder)
-        doReturn(mockSystemUidStatsResult).`when`(binder).getUidStats(SYSTEM_UID)
-        doReturn(mockMyUidStatsResult).`when`(binder).getUidStats(myUid)
-        doReturn(mockNotMyUidStatsResult).`when`(binder).getUidStats(notMyUid)
-    }
-
-    @After
-    fun tearDown() {
-        TrafficStats.setServiceForTest(null)
-        TrafficStats.setMyUidForTest(UID_ALL)
-    }
-
-    private fun assertUidStats(uid: Int, stats: StatsResult) {
-        assertEquals(stats.rxBytes, TrafficStats.getUidRxBytes(uid))
-        assertEquals(stats.rxPackets, TrafficStats.getUidRxPackets(uid))
-        assertEquals(stats.txBytes, TrafficStats.getUidTxBytes(uid))
-        assertEquals(stats.txPackets, TrafficStats.getUidTxPackets(uid))
-    }
-
-    // Verify a normal caller could get a quick UNSUPPORTED result in the TrafficStats
-    // without accessing the service if query stats other than itself.
-    @Test
-    fun testGetUidStats_appCaller() {
-        assertUidStats(SYSTEM_UID, unsupportedStatsResult)
-        assertUidStats(notMyUid, unsupportedStatsResult)
-        verify(binder, never()).getUidStats(anyInt())
-        assertUidStats(myUid, mockMyUidStatsResult)
-    }
-
-    // Verify that callers with SYSTEM_UID can access network
-    // stats for other UIDs. While this behavior is not officially documented
-    // in the API, it exists for compatibility with existing callers that may
-    // rely on it.
-    @Test
-    fun testGetUidStats_systemCaller() {
-        TrafficStats.setMyUidForTest(SYSTEM_UID)
-        assertUidStats(SYSTEM_UID, mockSystemUidStatsResult)
-        assertUidStats(myUid, mockMyUidStatsResult)
-        assertUidStats(notMyUid, mockNotMyUidStatsResult)
-    }
-}
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 999d17d..f7d7c87 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -2369,6 +2369,18 @@
             mScheduledEvaluationTimeouts.add(new Pair<>(network.netId, delayMs));
             super.scheduleEvaluationTimeout(handler, network, delayMs);
         }
+
+        @Override
+        public int getDefaultCellularDataInactivityTimeout() {
+            // Needed to mock out the dependency on DeviceConfig
+            return 10;
+        }
+
+        @Override
+        public int getDefaultWifiDataInactivityTimeout() {
+            // Needed to mock out the dependency on DeviceConfig
+            return 15;
+        }
     }
 
     private class AutomaticOnOffKeepaliveTrackerDependencies
diff --git a/tests/unit/java/com/android/server/connectivityservice/CSNetworkActivityTest.kt b/tests/unit/java/com/android/server/connectivityservice/CSNetworkActivityTest.kt
index df0a2cc..ccbd6b3 100644
--- a/tests/unit/java/com/android/server/connectivityservice/CSNetworkActivityTest.kt
+++ b/tests/unit/java/com/android/server/connectivityservice/CSNetworkActivityTest.kt
@@ -21,6 +21,7 @@
 import android.net.ConnectivityManager.EXTRA_DEVICE_TYPE
 import android.net.ConnectivityManager.EXTRA_IS_ACTIVE
 import android.net.ConnectivityManager.EXTRA_REALTIME_NS
+import android.net.ConnectivitySettingsManager
 import android.net.LinkProperties
 import android.net.NetworkCapabilities
 import android.net.NetworkCapabilities.NET_CAPABILITY_IMS
@@ -41,12 +42,14 @@
 import com.android.testutils.DevSdkIgnoreRunner
 import com.android.testutils.RecorderCallback.CallbackEntry.Lost
 import com.android.testutils.TestableNetworkCallback
+import java.time.Duration
 import kotlin.test.assertNotNull
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.anyString
 import org.mockito.ArgumentMatchers.eq
 import org.mockito.Mockito.anyInt
 import org.mockito.Mockito.anyLong
@@ -69,6 +72,18 @@
 @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
 class CSNetworkActivityTest : CSTest() {
 
+    private fun setMobileDataActivityTimeout(timeoutSeconds: Int) {
+        ConnectivitySettingsManager.setMobileDataActivityTimeout(
+            context, Duration.ofSeconds(timeoutSeconds.toLong())
+        )
+    }
+
+    private fun setWifiDataActivityTimeout(timeoutSeconds: Int) {
+        ConnectivitySettingsManager.setWifiDataActivityTimeout(
+            context, Duration.ofSeconds(timeoutSeconds.toLong())
+        )
+    }
+
     private fun getRegisteredNetdUnsolicitedEventListener(): BaseNetdUnsolicitedEventListener {
         val captor = ArgumentCaptor.forClass(BaseNetdUnsolicitedEventListener::class.java)
         verify(netd).registerUnsolicitedEventListener(captor.capture())
@@ -252,8 +267,122 @@
         cm.unregisterNetworkCallback(dataNetworkCb)
         cm.unregisterNetworkCallback(imsNetworkCb)
     }
+
+    @Test
+    fun testCellularIdleTimerSettingsTimeout() {
+        val cellNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_CELLULAR)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_SUSPENDED)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val cellLp = LinkProperties().apply {
+            interfaceName = DATA_CELL_IFNAME
+        }
+
+        val settingsTimeout: Int = deps.defaultCellDataInactivityTimeoutForTest + 432
+        // DATA_ACTIVITY_TIMEOUT_MOBILE is set, so the default should be ignored.
+        setMobileDataActivityTimeout(settingsTimeout)
+        val cellAgent = Agent(nc = cellNc, lp = cellLp)
+        cellAgent.connect()
+
+        verify(netd).idletimerAddInterface(eq(DATA_CELL_IFNAME), eq(settingsTimeout), anyString())
+    }
+
+    @Test
+    fun testCellularIdleTimerDefaultTimeout() {
+        val cellNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_CELLULAR)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_SUSPENDED)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val cellLp = LinkProperties().apply {
+            interfaceName = DATA_CELL_IFNAME
+        }
+
+        val testTimeout: Int = deps.defaultCellDataInactivityTimeoutForTest
+        // DATA_ACTIVITY_TIMEOUT_MOBILE is not set, so the default should be used.
+        val cellAgent = Agent(nc = cellNc, lp = cellLp)
+        cellAgent.connect()
+
+        verify(netd).idletimerAddInterface(eq(DATA_CELL_IFNAME), eq(testTimeout), anyString())
+    }
+
+    @Test
+    fun testCellularIdleTimerDisabled() {
+        val cellNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_CELLULAR)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_SUSPENDED)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val cellLp = LinkProperties().apply {
+            interfaceName = DATA_CELL_IFNAME
+        }
+        setMobileDataActivityTimeout(0)
+        val cellAgent = Agent(nc = cellNc, lp = cellLp)
+        cellAgent.connect()
+
+        verify(netd, never()).idletimerAddInterface(eq(DATA_CELL_IFNAME), anyInt(), anyString())
+    }
+
+    @Test
+    fun testWifiIdleTimerSettingsTimeout() {
+        val wifiNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_WIFI)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val wifiLp = LinkProperties().apply {
+            interfaceName = WIFI_IFNAME
+        }
+        val settingsTimeout: Int = deps.defaultWifiDataInactivityTimeout + 435
+        setWifiDataActivityTimeout(settingsTimeout)
+        // DATA_ACTIVITY_TIMEOUT_MOBILE is set, so the default should be ignored.
+        val wifiAgent = Agent(nc = wifiNc, lp = wifiLp)
+        wifiAgent.connect()
+
+        verify(netd).idletimerAddInterface(eq(WIFI_IFNAME), eq(settingsTimeout), anyString())
+    }
+
+    @Test
+    fun testWifiIdleTimerDefaultTimeout() {
+        val wifiNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_WIFI)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val wifiLp = LinkProperties().apply {
+            interfaceName = WIFI_IFNAME
+        }
+        val testTimeout: Int = deps.defaultWifiDataInactivityTimeoutForTest
+        // DATA_ACTIVITY_TIMEOUT_WIFI is not set, so the default should be used.
+        val wifiAgent = Agent(nc = wifiNc, lp = wifiLp)
+        wifiAgent.connect()
+
+        verify(netd).idletimerAddInterface(eq(WIFI_IFNAME), eq(testTimeout), anyString())
+    }
+
+    @Test
+    fun testWifiIdleTimerDisabled() {
+        val wifiNc = NetworkCapabilities.Builder()
+            .addTransportType(TRANSPORT_WIFI)
+            .addCapability(NET_CAPABILITY_INTERNET)
+            .addCapability(NET_CAPABILITY_NOT_VCN_MANAGED)
+            .build()
+        val wifiLp = LinkProperties().apply {
+            interfaceName = WIFI_IFNAME
+        }
+        setWifiDataActivityTimeout(0)
+        val wifiAgent = Agent(nc = wifiNc, lp = wifiLp)
+        wifiAgent.connect()
+
+        verify(netd, never()).idletimerAddInterface(eq(WIFI_IFNAME), anyInt(), anyString())
+    }
 }
 
+
 internal fun CSContext.expectDataActivityBroadcast(
         deviceType: Int,
         isActive: Boolean,
diff --git a/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt b/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
index 46c25d2..ae196a6 100644
--- a/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
+++ b/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
@@ -341,6 +341,18 @@
             }
         }
 
+        // Need a non-zero value to avoid disarming the timer.
+        val defaultCellDataInactivityTimeoutForTest: Int = 81
+        override fun getDefaultCellularDataInactivityTimeout(): Int {
+            return defaultCellDataInactivityTimeoutForTest
+        }
+
+        // Need a non-zero value to avoid disarming the timer.
+        val defaultWifiDataInactivityTimeoutForTest: Int = 121
+        override fun getDefaultWifiDataInactivityTimeout(): Int {
+            return defaultWifiDataInactivityTimeoutForTest
+        }
+
         override fun isChangeEnabled(changeId: Long, pkg: String, user: UserHandle) =
                 changeId in enabledChangeIds
         override fun isChangeEnabled(changeId: Long, uid: Int) =
diff --git a/thread/framework/java/android/net/thread/ThreadNetworkSpecifier.java b/thread/framework/java/android/net/thread/ThreadNetworkSpecifier.java
new file mode 100644
index 0000000..205c16e
--- /dev/null
+++ b/thread/framework/java/android/net/thread/ThreadNetworkSpecifier.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2024 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.thread;
+
+import static android.net.thread.ActiveOperationalDataset.LENGTH_EXTENDED_PAN_ID;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.net.NetworkSpecifier;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import com.android.net.module.util.HexDump;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * Represents and identifies a Thread network.
+ *
+ * @hide
+ */
+public final class ThreadNetworkSpecifier extends NetworkSpecifier implements Parcelable {
+    /** The Extended PAN ID of a Thread network. */
+    @NonNull private final byte[] mExtendedPanId;
+
+    /** The Active Timestamp of a Thread network. */
+    @Nullable private final OperationalDatasetTimestamp mActiveTimestamp;
+
+    private final boolean mRouterEligibleForLeader;
+
+    private ThreadNetworkSpecifier(@NonNull Builder builder) {
+        mExtendedPanId = builder.mExtendedPanId.clone();
+        mActiveTimestamp = builder.mActiveTimestamp;
+        mRouterEligibleForLeader = builder.mRouterEligibleForLeader;
+    }
+
+    /** Returns the Extended PAN ID of the Thread network this specifier refers to. */
+    @NonNull
+    public byte[] getExtendedPanId() {
+        return mExtendedPanId.clone();
+    }
+
+    /**
+     * Returns the Active Timestamp of the Thread network this specifier refers to, or {@code null}
+     * if not specified.
+     */
+    @Nullable
+    public OperationalDatasetTimestamp getActiveTimestamp() {
+        return mActiveTimestamp;
+    }
+
+    /**
+     * Returns {@code true} if this device can be a leader during attachment when there are no
+     * nearby routers.
+     */
+    public boolean isRouterEligibleForLeader() {
+        return mRouterEligibleForLeader;
+    }
+
+    /**
+     * Returns {@code true} if both {@link #getExtendedPanId()} and {@link #getActiveTimestamp()}
+     * (if not {@code null}) of the two {@link ThreadNetworkSpecifier} objects are equal.
+     *
+     * <p>Note value of {@link #isRouterEligibleForLeader()} is expiclitly excluded because this is
+     * not part of the identifier.
+     *
+     * @hide
+     */
+    @Override
+    public boolean canBeSatisfiedBy(@Nullable NetworkSpecifier other) {
+        if (!(other instanceof ThreadNetworkSpecifier)) {
+            return false;
+        }
+        ThreadNetworkSpecifier otherSpecifier = (ThreadNetworkSpecifier) other;
+
+        if (mActiveTimestamp != null && !mActiveTimestamp.equals(otherSpecifier.mActiveTimestamp)) {
+            return false;
+        }
+
+        return Arrays.equals(mExtendedPanId, otherSpecifier.mExtendedPanId);
+    }
+
+    @Override
+    public boolean equals(@Nullable Object other) {
+        if (!(other instanceof ThreadNetworkSpecifier)) {
+            return false;
+        } else if (this == other) {
+            return true;
+        }
+
+        ThreadNetworkSpecifier otherSpecifier = (ThreadNetworkSpecifier) other;
+
+        return Arrays.equals(mExtendedPanId, otherSpecifier.mExtendedPanId)
+                && Objects.equals(mActiveTimestamp, otherSpecifier.mActiveTimestamp)
+                && mRouterEligibleForLeader == otherSpecifier.mRouterEligibleForLeader;
+    }
+
+    @Override
+    public int hashCode() {
+        return deepHashCode(mExtendedPanId, mActiveTimestamp, mRouterEligibleForLeader);
+    }
+
+    /** An easy-to-use wrapper of {@link Arrays#deepHashCode}. */
+    private static int deepHashCode(Object... values) {
+        return Arrays.deepHashCode(values);
+    }
+
+    @Override
+    public String toString() {
+        return "ThreadNetworkSpecifier{extendedPanId="
+                + HexDump.toHexString(mExtendedPanId)
+                + ", activeTimestamp="
+                + mActiveTimestamp
+                + ", routerEligibleForLeader="
+                + mRouterEligibleForLeader
+                + "}";
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        dest.writeByteArray(mExtendedPanId);
+        dest.writeByteArray(mActiveTimestamp != null ? mActiveTimestamp.toTlvValue() : null);
+        dest.writeBoolean(mRouterEligibleForLeader);
+    }
+
+    public static final @NonNull Parcelable.Creator<ThreadNetworkSpecifier> CREATOR =
+            new Parcelable.Creator<ThreadNetworkSpecifier>() {
+                @Override
+                public ThreadNetworkSpecifier createFromParcel(Parcel in) {
+                    byte[] extendedPanId = in.createByteArray();
+                    byte[] activeTimestampBytes = in.createByteArray();
+                    OperationalDatasetTimestamp activeTimestamp =
+                            (activeTimestampBytes != null)
+                                    ? OperationalDatasetTimestamp.fromTlvValue(activeTimestampBytes)
+                                    : null;
+                    boolean routerEligibleForLeader = in.readBoolean();
+
+                    return new Builder(extendedPanId)
+                            .setActiveTimestamp(activeTimestamp)
+                            .setRouterEligibleForLeader(routerEligibleForLeader)
+                            .build();
+                }
+
+                @Override
+                public ThreadNetworkSpecifier[] newArray(int size) {
+                    return new ThreadNetworkSpecifier[size];
+                }
+            };
+
+    /** The builder for creating {@link ActiveOperationalDataset} objects. */
+    public static final class Builder {
+        @NonNull private final byte[] mExtendedPanId;
+        @Nullable private OperationalDatasetTimestamp mActiveTimestamp;
+        private boolean mRouterEligibleForLeader;
+
+        /**
+         * Creates a new {@link Builder} object with given Extended PAN ID.
+         *
+         * @throws IllegalArgumentException if {@code extendedPanId} is {@code null} or the length
+         *     is not {@link ActiveOperationalDataset#LENGTH_EXTENDED_PAN_ID}
+         */
+        public Builder(@NonNull byte[] extendedPanId) {
+            if (extendedPanId == null || extendedPanId.length != LENGTH_EXTENDED_PAN_ID) {
+                throw new IllegalArgumentException(
+                        "extendedPanId is null or length is not "
+                                + LENGTH_EXTENDED_PAN_ID
+                                + ": "
+                                + Arrays.toString(extendedPanId));
+            }
+            mExtendedPanId = extendedPanId.clone();
+            mRouterEligibleForLeader = false;
+        }
+
+        /**
+         * Creates a new {@link Builder} object by copying the data in the given {@code specifier}
+         * object.
+         */
+        public Builder(@NonNull ThreadNetworkSpecifier specifier) {
+            this(specifier.getExtendedPanId());
+            setActiveTimestamp(specifier.getActiveTimestamp());
+            setRouterEligibleForLeader(specifier.isRouterEligibleForLeader());
+        }
+
+        /** Sets the Active Timestamp of the Thread network. */
+        @NonNull
+        public Builder setActiveTimestamp(@Nullable OperationalDatasetTimestamp activeTimestamp) {
+            mActiveTimestamp = activeTimestamp;
+            return this;
+        }
+
+        /**
+         * Sets whether this device should be a leader during attachment when there are no nearby
+         * routers.
+         */
+        @NonNull
+        public Builder setRouterEligibleForLeader(boolean eligible) {
+            mRouterEligibleForLeader = eligible;
+            return this;
+        }
+
+        /** Creates a new {@link ThreadNetworkSpecifier} object from values set so far. */
+        @NonNull
+        public ThreadNetworkSpecifier build() {
+            return new ThreadNetworkSpecifier(this);
+        }
+    }
+}
diff --git a/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java b/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
index e3c2a28..8747b44 100644
--- a/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
+++ b/thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java
@@ -1405,9 +1405,10 @@
     }
 
     private void setInfraLinkState(InfraLinkState newInfraLinkState) {
-        if (!Objects.equals(mInfraLinkState, newInfraLinkState)) {
-            LOG.i("Infra link state changed: " + mInfraLinkState + " -> " + newInfraLinkState);
+        if (Objects.equals(mInfraLinkState, newInfraLinkState)) {
+            return ;
         }
+        LOG.i("Infra link state changed: " + mInfraLinkState + " -> " + newInfraLinkState);
         setInfraLinkInterfaceName(newInfraLinkState.interfaceName);
         setInfraLinkNat64Prefix(newInfraLinkState.nat64Prefix);
         setInfraLinkDnsServers(newInfraLinkState.dnsServers);
@@ -1415,6 +1416,9 @@
     }
 
     private void setInfraLinkInterfaceName(String newInfraLinkInterfaceName) {
+        if (Objects.equals(mInfraLinkState.interfaceName, newInfraLinkInterfaceName)) {
+            return ;
+        }
         ParcelFileDescriptor infraIcmp6Socket = null;
         if (newInfraLinkInterfaceName != null) {
             try {
@@ -1435,6 +1439,9 @@
     }
 
     private void setInfraLinkNat64Prefix(@Nullable String newNat64Prefix) {
+        if (Objects.equals(newNat64Prefix, mInfraLinkState.nat64Prefix)) {
+            return ;
+        }
         try {
             getOtDaemon()
                     .setInfraLinkNat64Prefix(
@@ -1445,6 +1452,9 @@
     }
 
     private void setInfraLinkDnsServers(List<String> newDnsServers) {
+        if (Objects.equals(newDnsServers, mInfraLinkState.dnsServers)) {
+            return ;
+        }
         try {
             getOtDaemon()
                     .setInfraLinkDnsServers(
@@ -1783,6 +1793,7 @@
                     // do nothing if the client is dead
                 }
             }
+            mInfraLinkState = newInfraLinkStateBuilder().build();
         }
 
         private void onThreadEnabledChanged(int state, long listenerId) {
diff --git a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
index 1a2ff06..ddbef47 100644
--- a/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
+++ b/thread/tests/integration/src/android/net/thread/BorderRoutingTest.java
@@ -20,6 +20,7 @@
 import static android.net.InetAddresses.parseNumericAddress;
 import static android.net.thread.utils.IntegrationTestUtils.DEFAULT_DATASET;
 import static android.net.thread.utils.IntegrationTestUtils.buildIcmpv4EchoReply;
+import static android.net.thread.utils.IntegrationTestUtils.enableThreadAndJoinNetwork;
 import static android.net.thread.utils.IntegrationTestUtils.getIpv6LinkAddresses;
 import static android.net.thread.utils.IntegrationTestUtils.isExpectedIcmpv4Packet;
 import static android.net.thread.utils.IntegrationTestUtils.isExpectedIcmpv6Packet;
@@ -27,6 +28,7 @@
 import static android.net.thread.utils.IntegrationTestUtils.isInMulticastGroup;
 import static android.net.thread.utils.IntegrationTestUtils.isTo;
 import static android.net.thread.utils.IntegrationTestUtils.joinNetworkAndWaitForOmr;
+import static android.net.thread.utils.IntegrationTestUtils.leaveNetworkAndDisableThread;
 import static android.net.thread.utils.IntegrationTestUtils.newPacketReader;
 import static android.net.thread.utils.IntegrationTestUtils.pollForPacket;
 import static android.net.thread.utils.IntegrationTestUtils.sendUdpMessage;
@@ -73,7 +75,9 @@
 import com.android.testutils.TestNetworkTracker;
 
 import org.junit.After;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
@@ -116,7 +120,7 @@
     private final Context mContext = ApplicationProvider.getApplicationContext();
     private final ThreadNetworkControllerWrapper mController =
             ThreadNetworkControllerWrapper.newInstance(mContext);
-    private OtDaemonController mOtCtl;
+    private final OtDaemonController mOtCtl = new OtDaemonController();
     private HandlerThread mHandlerThread;
     private Handler mHandler;
     private TestNetworkTracker mInfraNetworkTracker;
@@ -124,20 +128,24 @@
     private PollPacketReader mInfraNetworkReader;
     private InfraNetworkDevice mInfraDevice;
 
+    @BeforeClass
+    public static void beforeClass() throws Exception {
+        enableThreadAndJoinNetwork(DEFAULT_DATASET);
+    }
+
+    @AfterClass
+    public static void afterClass() throws Exception {
+        leaveNetworkAndDisableThread();
+    }
+
     @Before
     public void setUp() throws Exception {
-        // TODO: b/323301831 - This is a workaround to avoid unnecessary delay to re-form a network
-        mOtCtl = new OtDaemonController();
-        mOtCtl.factoryReset();
-
         mHandlerThread = new HandlerThread(getClass().getSimpleName());
         mHandlerThread.start();
         mHandler = new Handler(mHandlerThread.getLooper());
         mFtds = new ArrayList<>();
 
         setUpInfraNetwork();
-        mController.setEnabledAndWait(true);
-        mController.joinAndWait(DEFAULT_DATASET);
 
         // Creates a infra network device.
         mInfraNetworkReader = newPacketReader(mInfraNetworkTracker.getTestIface(), mHandler);
@@ -152,8 +160,6 @@
     @After
     public void tearDown() throws Exception {
         mController.setTestNetworkAsUpstreamAndWait(null);
-        mController.leaveAndWait();
-        tearDownInfraNetwork();
 
         mHandlerThread.quitSafely();
         mHandlerThread.join();
diff --git a/thread/tests/integration/src/android/net/thread/InternetAccessTest.kt b/thread/tests/integration/src/android/net/thread/InternetAccessTest.kt
index 9b787f5..162f58e 100644
--- a/thread/tests/integration/src/android/net/thread/InternetAccessTest.kt
+++ b/thread/tests/integration/src/android/net/thread/InternetAccessTest.kt
@@ -24,7 +24,9 @@
 import android.net.thread.utils.FullThreadDevice
 import android.net.thread.utils.InfraNetworkDevice
 import android.net.thread.utils.IntegrationTestUtils.DEFAULT_DATASET
+import android.net.thread.utils.IntegrationTestUtils.enableThreadAndJoinNetwork
 import android.net.thread.utils.IntegrationTestUtils.joinNetworkAndWaitForOmr
+import android.net.thread.utils.IntegrationTestUtils.leaveNetworkAndDisableThread
 import android.net.thread.utils.IntegrationTestUtils.newPacketReader
 import android.net.thread.utils.IntegrationTestUtils.setUpInfraNetwork
 import android.net.thread.utils.IntegrationTestUtils.startInfraDeviceAndWaitForOnLinkAddr
@@ -32,6 +34,7 @@
 import android.net.thread.utils.IntegrationTestUtils.waitFor
 import android.net.thread.utils.OtDaemonController
 import android.net.thread.utils.TestDnsServer
+import android.net.thread.utils.TestUdpEchoServer
 import android.net.thread.utils.ThreadFeatureCheckerRule
 import android.net.thread.utils.ThreadFeatureCheckerRule.RequiresSimulationThreadDevice
 import android.net.thread.utils.ThreadFeatureCheckerRule.RequiresThreadFeature
@@ -48,9 +51,12 @@
 import com.google.common.truth.Truth.assertThat
 import java.net.Inet4Address
 import java.net.InetAddress
+import java.net.InetSocketAddress
 import java.time.Duration
 import org.junit.After
+import org.junit.AfterClass
 import org.junit.Before
+import org.junit.BeforeClass
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -61,26 +67,42 @@
 @RequiresSimulationThreadDevice
 @LargeTest
 class InternetAccessTest {
-    private val TAG = BorderRoutingTest::class.java.simpleName
-    private val NUM_FTD = 1
-    private val DNS_SERVER_ADDR = parseNumericAddress("8.8.8.8") as Inet4Address
-    private val ANSWER_RECORDS =
-        listOf(
-            DnsPacket.DnsRecord.makeAOrAAAARecord(
-                ANSECTION,
-                "google.com",
-                CLASS_IN,
-                30 /* ttl */,
-                parseNumericAddress("1.2.3.4"),
-            ),
-            DnsPacket.DnsRecord.makeAOrAAAARecord(
-                ANSECTION,
-                "google.com",
-                CLASS_IN,
-                30 /* ttl */,
-                parseNumericAddress("2001::234"),
-            ),
-        )
+    companion object {
+        private val TAG = BorderRoutingTest::class.java.simpleName
+        private val NUM_FTD = 1
+        private val DNS_SERVER_ADDR = parseNumericAddress("8.8.8.8") as Inet4Address
+        private val UDP_ECHO_SERVER_ADDRESS =
+            InetSocketAddress(parseNumericAddress("1.2.3.4"), 12345)
+        private val ANSWER_RECORDS =
+            listOf(
+                DnsPacket.DnsRecord.makeAOrAAAARecord(
+                    ANSECTION,
+                    "google.com",
+                    CLASS_IN,
+                    30 /* ttl */,
+                    parseNumericAddress("1.2.3.4"),
+                ),
+                DnsPacket.DnsRecord.makeAOrAAAARecord(
+                    ANSECTION,
+                    "google.com",
+                    CLASS_IN,
+                    30 /* ttl */,
+                    parseNumericAddress("2001::234"),
+                ),
+            )
+
+        @BeforeClass
+        @JvmStatic
+        fun beforeClass() {
+            enableThreadAndJoinNetwork(DEFAULT_DATASET)
+        }
+
+        @AfterClass
+        @JvmStatic
+        fun afterClass() {
+            leaveNetworkAndDisableThread()
+        }
+    }
 
     @get:Rule val threadRule = ThreadFeatureCheckerRule()
 
@@ -94,13 +116,12 @@
     private lateinit var infraNetworkReader: PollPacketReader
     private lateinit var infraDevice: InfraNetworkDevice
     private lateinit var dnsServer: TestDnsServer
+    private lateinit var udpEchoServer: TestUdpEchoServer
 
     @Before
     @Throws(Exception::class)
     fun setUp() {
-        // TODO: b/323301831 - This is a workaround to avoid unnecessary delay to re-form a network
         otCtl = OtDaemonController()
-        otCtl.factoryReset()
 
         handlerThread = HandlerThread(javaClass.simpleName)
         handlerThread.start()
@@ -108,16 +129,17 @@
         ftds = ArrayList()
 
         infraNetworkTracker = setUpInfraNetwork(context, controller)
-        controller.setEnabledAndWait(true)
-        controller.joinAndWait(DEFAULT_DATASET)
 
-        // Creates a infra network device.
+        // Create an infra network device.
         infraNetworkReader = newPacketReader(infraNetworkTracker.testIface, handler)
         infraDevice = startInfraDeviceAndWaitForOnLinkAddr(infraNetworkReader)
 
         // Create a DNS server
         dnsServer = TestDnsServer(infraNetworkReader, DNS_SERVER_ADDR, ANSWER_RECORDS)
 
+        // Create a UDP echo server
+        udpEchoServer = TestUdpEchoServer(infraNetworkReader, UDP_ECHO_SERVER_ADDRESS)
+
         // Create Ftds
         for (i in 0 until NUM_FTD) {
             ftds.add(FullThreadDevice(15 + i /* node ID */))
@@ -128,10 +150,10 @@
     @Throws(Exception::class)
     fun tearDown() {
         controller.setTestNetworkAsUpstreamAndWait(null)
-        controller.leaveAndWait()
         tearDownInfraNetwork(infraNetworkTracker)
 
         dnsServer.stop()
+        udpEchoServer.stop()
 
         handlerThread.quitSafely()
         handlerThread.join()
@@ -166,6 +188,20 @@
         assertThat(ftd.resolveHost("google.com", TYPE_AAAA)).isEmpty()
     }
 
+    @Test
+    fun nat64Enabled_threadDeviceSendsUdpToEchoServer_replyIsReceived() {
+        controller.setNat64EnabledAndWait(true)
+        waitFor({ otCtl.hasNat64PrefixInNetdata() }, Duration.ofSeconds(10))
+        val ftd = ftds[0]
+        joinNetworkAndWaitForOmr(ftd, DEFAULT_DATASET)
+        udpEchoServer.start()
+
+        ftd.udpOpen()
+        ftd.udpSend("Hello,Thread", UDP_ECHO_SERVER_ADDRESS.address, UDP_ECHO_SERVER_ADDRESS.port)
+        val reply = ftd.udpReceive()
+        assertThat(reply).isEqualTo("Hello,Thread")
+    }
+
     private fun extractIpv4AddressFromMappedAddress(address: InetAddress): Inet4Address {
         return InetAddress.getByAddress(address.address.slice(12 until 16).toByteArray())
             as Inet4Address
diff --git a/thread/tests/integration/src/android/net/thread/ThreadIntegrationTest.java b/thread/tests/integration/src/android/net/thread/ThreadIntegrationTest.java
index 5613454..d41550b 100644
--- a/thread/tests/integration/src/android/net/thread/ThreadIntegrationTest.java
+++ b/thread/tests/integration/src/android/net/thread/ThreadIntegrationTest.java
@@ -29,6 +29,7 @@
 import static android.net.thread.utils.IntegrationTestUtils.getThreadNetwork;
 import static android.net.thread.utils.IntegrationTestUtils.isInMulticastGroup;
 import static android.net.thread.utils.IntegrationTestUtils.waitFor;
+import static android.net.thread.utils.ThreadNetworkControllerWrapper.JOIN_TIMEOUT;
 
 import static com.android.compatibility.common.util.SystemUtil.runShellCommand;
 import static com.android.compatibility.common.util.SystemUtil.runShellCommandOrThrow;
@@ -55,6 +56,7 @@
 import android.net.thread.utils.ThreadFeatureCheckerRule;
 import android.net.thread.utils.ThreadFeatureCheckerRule.RequiresThreadFeature;
 import android.net.thread.utils.ThreadNetworkControllerWrapper;
+import android.net.thread.utils.ThreadStateListener;
 import android.os.SystemClock;
 
 import androidx.test.core.app.ApplicationProvider;
@@ -138,6 +140,8 @@
 
     @After
     public void tearDown() throws Exception {
+        ThreadStateListener.stopAllListeners();
+
         mController.setTestNetworkAsUpstreamAndWait(null);
         mController.leaveAndWait();
         mController.setConfigurationAndWait(DEFAULT_CONFIG);
@@ -268,6 +272,20 @@
     }
 
     @Test
+    public void joinNetwork_joinTheSameNetworkTwice_neverDetached() throws Exception {
+        mController.joinAndWait(DEFAULT_DATASET);
+        mController.waitForRole(DEVICE_ROLE_LEADER, JOIN_TIMEOUT);
+
+        var listener = ThreadStateListener.startListener(mController.get());
+        mController.joinAndWait(DEFAULT_DATASET);
+
+        assertThat(
+                        listener.pollForAnyRoleOf(
+                                List.of(DEVICE_ROLE_DETACHED, DEVICE_ROLE_STOPPED), JOIN_TIMEOUT))
+                .isNull();
+    }
+
+    @Test
     public void edPingsMeshLocalAddresses_oneReplyPerRequest() throws Exception {
         mController.joinAndWait(DEFAULT_DATASET);
         startFtdChild(mFtd, DEFAULT_DATASET);
diff --git a/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java b/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
index 5b532c7..209eed6 100644
--- a/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
+++ b/thread/tests/integration/src/android/net/thread/utils/FullThreadDevice.java
@@ -234,8 +234,8 @@
         return matcher.group(4);
     }
 
-    /** Sends a UDP message to given IPv6 address and port. */
-    public void udpSend(String message, Inet6Address serverAddr, int serverPort) {
+    /** Sends a UDP message to given IP address and port. */
+    public void udpSend(String message, InetAddress serverAddr, int serverPort) {
         executeCommand("udp send %s %d %s", serverAddr.getHostAddress(), serverPort, message);
     }
 
diff --git a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
index dc2a9c9..c3859c1 100644
--- a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
+++ b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
@@ -590,6 +590,27 @@
         return ftd.omrAddress
     }
 
+    /** Enables Thread and joins the specified Thread network. */
+    @JvmStatic
+    fun enableThreadAndJoinNetwork(dataset: ActiveOperationalDataset) {
+        // TODO: b/323301831 - This is a workaround to avoid unnecessary delay to re-form a network
+        OtDaemonController().factoryReset();
+
+        val context: Context = requireNotNull(ApplicationProvider.getApplicationContext());
+        val controller = requireNotNull(ThreadNetworkControllerWrapper.newInstance(context));
+        controller.setEnabledAndWait(true);
+        controller.joinAndWait(dataset);
+    }
+
+    /** Leaves the Thread network and disables Thread. */
+    @JvmStatic
+    fun leaveNetworkAndDisableThread() {
+        val context: Context = requireNotNull(ApplicationProvider.getApplicationContext());
+        val controller = requireNotNull(ThreadNetworkControllerWrapper.newInstance(context));
+        controller.leaveAndWait();
+        controller.setEnabledAndWait(false);
+    }
+
     private open class DefaultDiscoveryListener : NsdManager.DiscoveryListener {
         override fun onStartDiscoveryFailed(serviceType: String, errorCode: Int) {}
         override fun onStopDiscoveryFailed(serviceType: String, errorCode: Int) {}
diff --git a/thread/tests/integration/src/android/net/thread/utils/TestDnsServer.kt b/thread/tests/integration/src/android/net/thread/utils/TestDnsServer.kt
index c52fc49..f97c0f2 100644
--- a/thread/tests/integration/src/android/net/thread/utils/TestDnsServer.kt
+++ b/thread/tests/integration/src/android/net/thread/utils/TestDnsServer.kt
@@ -16,18 +16,16 @@
 
 package android.net.thread.utils
 
-import android.net.thread.utils.IntegrationTestUtils.pollForPacket
 import android.system.OsConstants.IPPROTO_IP
 import android.system.OsConstants.IPPROTO_UDP
 import com.android.net.module.util.DnsPacket
 import com.android.net.module.util.PacketBuilder
-import com.android.net.module.util.Struct
 import com.android.net.module.util.structs.Ipv4Header
 import com.android.net.module.util.structs.UdpHeader
 import com.android.testutils.PollPacketReader
 import java.net.InetAddress
+import java.net.InetSocketAddress
 import java.nio.ByteBuffer
-import kotlin.concurrent.thread
 
 /**
  * A class that simulates a DNS server.
@@ -41,11 +39,12 @@
 class TestDnsServer(
     private val packetReader: PollPacketReader,
     private val serverAddress: InetAddress,
-    private val answerRecords: List<DnsPacket.DnsRecord>,
-) {
-    private val TAG = TestDnsServer::class.java.simpleName
-    private val DNS_UDP_PORT = 53
-    private var workerThread: Thread? = null
+    private val serverAnswers: List<DnsPacket.DnsRecord>,
+) : TestUdpServer(packetReader, InetSocketAddress(serverAddress, DNS_UDP_PORT)) {
+    companion object {
+        private val TAG = TestDnsServer::class.java.simpleName
+        private const val DNS_UDP_PORT = 53
+    }
 
     private class TestDnsPacket : DnsPacket {
 
@@ -61,49 +60,12 @@
         val records = super.mRecords
     }
 
-    /**
-     * Starts the DNS server to respond to DNS requests.
-     *
-     * <p> The server polls the DNS requests from the {@code packetReader} and responds with the
-     * {@code answerRecords}. The server will automatically stop when it fails to poll a DNS request
-     * within the timeout (3000 ms, as defined in IntegrationTestUtils).
-     */
-    fun start() {
-        workerThread = thread {
-            var requestPacket: ByteArray
-            while (true) {
-                requestPacket = pollForDnsPacket() ?: break
-                val buf = ByteBuffer.wrap(requestPacket)
-                packetReader.sendResponse(buildDnsResponse(buf, answerRecords))
-            }
-        }
-    }
-
-    /** Stops the DNS server. */
-    fun stop() {
-        workerThread?.join()
-    }
-
-    private fun pollForDnsPacket(): ByteArray? {
-        val filter =
-            fun(packet: ByteArray): Boolean {
-                val buf = ByteBuffer.wrap(packet)
-                val ipv4Header = Struct.parse(Ipv4Header::class.java, buf) ?: return false
-                val udpHeader = Struct.parse(UdpHeader::class.java, buf) ?: return false
-                return ipv4Header.dstIp == serverAddress && udpHeader.dstPort == DNS_UDP_PORT
-            }
-        return pollForPacket(packetReader, filter)
-    }
-
-    private fun buildDnsResponse(
-        requestPacket: ByteBuffer,
-        serverAnswers: List<DnsPacket.DnsRecord>,
+    override fun buildResponse(
+        requestIpv4Header: Ipv4Header,
+        requestUdpHeader: UdpHeader,
+        requestUdpPayload: ByteArray,
     ): ByteBuffer? {
-        val requestIpv4Header = Struct.parse(Ipv4Header::class.java, requestPacket) ?: return null
-        val requestUdpHeader = Struct.parse(UdpHeader::class.java, requestPacket) ?: return null
-        val remainingRequestPacket = ByteArray(requestPacket.remaining())
-        requestPacket.get(remainingRequestPacket)
-        val requestDnsPacket = TestDnsPacket(remainingRequestPacket)
+        val requestDnsPacket = TestDnsPacket(requestUdpPayload)
         val requestDnsHeader = requestDnsPacket.header
 
         val answerRecords =
diff --git a/thread/tests/integration/src/android/net/thread/utils/TestUdpEchoServer.kt b/thread/tests/integration/src/android/net/thread/utils/TestUdpEchoServer.kt
new file mode 100644
index 0000000..9fcd6a4
--- /dev/null
+++ b/thread/tests/integration/src/android/net/thread/utils/TestUdpEchoServer.kt
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2024 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.thread.utils
+
+import android.system.OsConstants.IPPROTO_IP
+import android.system.OsConstants.IPPROTO_UDP
+import com.android.net.module.util.PacketBuilder
+import com.android.net.module.util.structs.Ipv4Header
+import com.android.net.module.util.structs.UdpHeader
+import com.android.testutils.PollPacketReader
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+
+/**
+ * A class that simulates a UDP echo server that replies to incoming UDP message with the same
+ * payload.
+ *
+ * @param packetReader the packet reader to poll UDP requests from
+ * @param serverAddress the address and port of the UDP server
+ */
+class TestUdpEchoServer(
+    private val packetReader: PollPacketReader,
+    private val serverAddress: InetSocketAddress,
+) : TestUdpServer(packetReader, serverAddress) {
+    companion object {
+        private val TAG = TestUdpEchoServer::class.java.simpleName
+    }
+
+    override fun buildResponse(
+        requestIpv4Header: Ipv4Header,
+        requestUdpHeader: UdpHeader,
+        requestUdpPayload: ByteArray,
+    ): ByteBuffer? {
+        val buf =
+            PacketBuilder.allocate(
+                false /* hasEther */,
+                IPPROTO_IP,
+                IPPROTO_UDP,
+                requestUdpPayload.size,
+            )
+
+        val packetBuilder = PacketBuilder(buf)
+        packetBuilder.writeIpv4Header(
+            requestIpv4Header.tos,
+            requestIpv4Header.id,
+            requestIpv4Header.flagsAndFragmentOffset,
+            0x40 /* ttl */,
+            IPPROTO_UDP.toByte(),
+            requestIpv4Header.dstIp, /* srcIp */
+            requestIpv4Header.srcIp, /* dstIp */
+        )
+        packetBuilder.writeUdpHeader(
+            requestUdpHeader.dstPort.toShort() /* srcPort */,
+            requestUdpHeader.srcPort.toShort(), /* dstPort */
+        )
+        buf.put(requestUdpPayload)
+
+        return packetBuilder.finalizePacket()
+    }
+}
diff --git a/thread/tests/integration/src/android/net/thread/utils/TestUdpServer.kt b/thread/tests/integration/src/android/net/thread/utils/TestUdpServer.kt
new file mode 100644
index 0000000..fb0942e
--- /dev/null
+++ b/thread/tests/integration/src/android/net/thread/utils/TestUdpServer.kt
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2024 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.thread.utils
+
+import android.net.thread.utils.IntegrationTestUtils.pollForPacket
+import com.android.net.module.util.Struct
+import com.android.net.module.util.structs.Ipv4Header
+import com.android.net.module.util.structs.UdpHeader
+import com.android.testutils.PollPacketReader
+import java.net.InetSocketAddress
+import java.nio.ByteBuffer
+import kotlin.concurrent.thread
+
+/**
+ * A class that simulates a UDP server that replies to incoming UDP messages.
+ *
+ * @param packetReader the packet reader to poll UDP requests from
+ * @param serverAddress the address and port of the UDP server
+ */
+abstract class TestUdpServer(
+    private val packetReader: PollPacketReader,
+    private val serverAddress: InetSocketAddress,
+) {
+    private val TAG = TestUdpServer::class.java.simpleName
+    private var workerThread: Thread? = null
+
+    /**
+     * Starts the UDP server to respond to UDP messages.
+     *
+     * <p> The server polls the UDP messages from the {@code packetReader} and responds with a
+     * message built by {@code buildResponse}. The server will automatically stop when it fails to
+     * poll a UDP request within the timeout (3000 ms, as defined in IntegrationTestUtils).
+     */
+    fun start() {
+        workerThread = thread {
+            var requestPacket: ByteArray
+            while (true) {
+                requestPacket = pollForUdpPacket() ?: break
+                val buf = ByteBuffer.wrap(requestPacket)
+                packetReader.sendResponse(buildResponse(buf) ?: break)
+            }
+        }
+    }
+
+    /** Stops the UDP server. */
+    fun stop() {
+        workerThread?.join()
+    }
+
+    /**
+     * Builds the UDP response for the given UDP request.
+     *
+     * @param ipv4Header the IPv4 header of the UDP request
+     * @param udpHeader the UDP header of the UDP request
+     * @param udpPayload the payload of the UDP request
+     * @return the UDP response
+     */
+    abstract fun buildResponse(
+        requestIpv4Header: Ipv4Header,
+        requestUdpHeader: UdpHeader,
+        requestUdpPayload: ByteArray,
+    ): ByteBuffer?
+
+    private fun pollForUdpPacket(): ByteArray? {
+        val filter =
+            fun(packet: ByteArray): Boolean {
+                val buf = ByteBuffer.wrap(packet)
+                val ipv4Header = Struct.parse(Ipv4Header::class.java, buf) ?: return false
+                val udpHeader = Struct.parse(UdpHeader::class.java, buf) ?: return false
+                return ipv4Header.dstIp == serverAddress.address &&
+                    udpHeader.dstPort == serverAddress.port
+            }
+        return pollForPacket(packetReader, filter)
+    }
+
+    private fun buildResponse(requestPacket: ByteBuffer): ByteBuffer? {
+        val requestIpv4Header = Struct.parse(Ipv4Header::class.java, requestPacket) ?: return null
+        val requestUdpHeader = Struct.parse(UdpHeader::class.java, requestPacket) ?: return null
+        val remainingRequestPacket = ByteArray(requestPacket.remaining())
+        requestPacket.get(remainingRequestPacket)
+
+        return buildResponse(requestIpv4Header, requestUdpHeader, remainingRequestPacket)
+    }
+}
diff --git a/thread/tests/integration/src/android/net/thread/utils/ThreadNetworkControllerWrapper.java b/thread/tests/integration/src/android/net/thread/utils/ThreadNetworkControllerWrapper.java
index 4354702..b6114f3 100644
--- a/thread/tests/integration/src/android/net/thread/utils/ThreadNetworkControllerWrapper.java
+++ b/thread/tests/integration/src/android/net/thread/utils/ThreadNetworkControllerWrapper.java
@@ -37,6 +37,7 @@
 import android.os.OutcomeReceiver;
 
 import java.time.Duration;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
@@ -53,6 +54,9 @@
 
     private final ThreadNetworkController mController;
 
+    private final List<Integer> mDeviceRoleUpdates = new ArrayList<>();
+    @Nullable private StateCallback mStateCallback;
+
     /**
      * Returns a new {@link ThreadNetworkControllerWrapper} instance or {@code null} if Thread
      * feature is not supported on this device.
@@ -71,6 +75,15 @@
     }
 
     /**
+     * Returns the underlying {@link ThreadNetworkController} object or {@code null} if the current
+     * platform doesn't support it.
+     */
+    @Nullable
+    public ThreadNetworkController get() {
+        return mController;
+    }
+
+    /**
      * Returns the Thread enabled state.
      *
      * <p>The value can be one of {@code ThreadNetworkController#STATE_*}.
diff --git a/thread/tests/unit/src/android/net/thread/ThreadNetworkSpecifierTest.java b/thread/tests/unit/src/android/net/thread/ThreadNetworkSpecifierTest.java
new file mode 100644
index 0000000..c83cb7a
--- /dev/null
+++ b/thread/tests/unit/src/android/net/thread/ThreadNetworkSpecifierTest.java
@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2024 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.thread;
+
+import static com.android.testutils.ParcelUtils.assertParcelingIsLossless;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import androidx.test.filters.SmallTest;
+
+import com.google.common.testing.EqualsTester;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.time.Instant;
+import java.util.Arrays;
+import java.util.Collection;
+
+/** Tests for {@link ThreadNetworkSpecifier}. */
+@SmallTest
+@RunWith(Parameterized.class)
+public final class ThreadNetworkSpecifierTest {
+    public final byte[] mExtendedPanId;
+    public final OperationalDatasetTimestamp mActiveTimestamp;
+    public final boolean mRouterEligibleForLeader;
+
+    @Parameterized.Parameters
+    public static Collection specifierArguments() {
+        var timestampNow = OperationalDatasetTimestamp.fromInstant(Instant.now());
+        return Arrays.asList(
+                new Object[][] {
+                    {new byte[] {0, 1, 2, 3, 4, 5, 6, 7}, null, false},
+                    {new byte[] {1, 1, 1, 1, 2, 2, 2, 2}, timestampNow, true},
+                    {new byte[] {1, 1, 1, 1, 2, 2, 2, 2}, timestampNow, false},
+                });
+    }
+
+    public ThreadNetworkSpecifierTest(
+            byte[] extendedPanId,
+            OperationalDatasetTimestamp activeTimestamp,
+            boolean routerEligibleForLeader) {
+        mExtendedPanId = extendedPanId.clone();
+        mActiveTimestamp = activeTimestamp;
+        mRouterEligibleForLeader = routerEligibleForLeader;
+    }
+
+    @Test
+    public void parcelable_parcelingIsLossLess() {
+        ThreadNetworkSpecifier specifier =
+                new ThreadNetworkSpecifier.Builder(mExtendedPanId)
+                        .setActiveTimestamp(mActiveTimestamp)
+                        .setRouterEligibleForLeader(mRouterEligibleForLeader)
+                        .build();
+        assertParcelingIsLossless(specifier);
+    }
+
+    @Test
+    public void builder_correctValuesAreSet() {
+        ThreadNetworkSpecifier specifier =
+                new ThreadNetworkSpecifier.Builder(mExtendedPanId)
+                        .setActiveTimestamp(mActiveTimestamp)
+                        .setRouterEligibleForLeader(mRouterEligibleForLeader)
+                        .build();
+
+        assertThat(specifier.getExtendedPanId()).isEqualTo(mExtendedPanId);
+        assertThat(specifier.getActiveTimestamp()).isEqualTo(mActiveTimestamp);
+        assertThat(specifier.isRouterEligibleForLeader()).isEqualTo(mRouterEligibleForLeader);
+    }
+
+    @Test
+    public void builderConstructor_specifiersAreEqual() {
+        ThreadNetworkSpecifier specifier1 =
+                new ThreadNetworkSpecifier.Builder(mExtendedPanId)
+                        .setActiveTimestamp(mActiveTimestamp)
+                        .setRouterEligibleForLeader(mRouterEligibleForLeader)
+                        .build();
+
+        ThreadNetworkSpecifier specifier2 = new ThreadNetworkSpecifier.Builder(specifier1).build();
+
+        assertThat(specifier1).isEqualTo(specifier2);
+    }
+
+    @Test
+    public void equalsTester() {
+        var timestampNow = OperationalDatasetTimestamp.fromInstant(Instant.now());
+        new EqualsTester()
+                .addEqualityGroup(
+                        new ThreadNetworkSpecifier.Builder(new byte[] {0, 1, 2, 3, 4, 5, 6, 7})
+                                .setActiveTimestamp(timestampNow)
+                                .setRouterEligibleForLeader(true)
+                                .build(),
+                        new ThreadNetworkSpecifier.Builder(new byte[] {0, 1, 2, 3, 4, 5, 6, 7})
+                                .setActiveTimestamp(timestampNow)
+                                .setRouterEligibleForLeader(true)
+                                .build())
+                .addEqualityGroup(
+                        new ThreadNetworkSpecifier.Builder(new byte[] {0, 1, 2, 3, 4, 5, 6, 7})
+                                .setActiveTimestamp(null)
+                                .setRouterEligibleForLeader(false)
+                                .build(),
+                        new ThreadNetworkSpecifier.Builder(new byte[] {0, 1, 2, 3, 4, 5, 6, 7})
+                                .setActiveTimestamp(null)
+                                .setRouterEligibleForLeader(false)
+                                .build())
+                .addEqualityGroup(
+                        new ThreadNetworkSpecifier.Builder(new byte[] {1, 1, 1, 1, 2, 2, 2, 2})
+                                .setActiveTimestamp(null)
+                                .setRouterEligibleForLeader(false)
+                                .build(),
+                        new ThreadNetworkSpecifier.Builder(new byte[] {1, 1, 1, 1, 2, 2, 2, 2})
+                                .setActiveTimestamp(null)
+                                .setRouterEligibleForLeader(false)
+                                .build())
+                .testEquals();
+    }
+}
diff --git a/thread/tests/utils/src/android/net/thread/utils/ThreadStateListener.java b/thread/tests/utils/src/android/net/thread/utils/ThreadStateListener.java
new file mode 100644
index 0000000..21eb7d9
--- /dev/null
+++ b/thread/tests/utils/src/android/net/thread/utils/ThreadStateListener.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2024 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.thread.utils;
+
+import static android.Manifest.permission.ACCESS_NETWORK_STATE;
+
+import static com.android.testutils.TestPermissionUtil.runAsShell;
+
+import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
+
+import android.annotation.Nullable;
+import android.net.thread.ThreadNetworkController;
+import android.net.thread.ThreadNetworkController.StateCallback;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.ArrayTrackRecord;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A listener for sequential Thread state updates.
+ *
+ * <p>This is a wrapper around {@link ThreadNetworkController#registerStateCallback} to make
+ * synchronized access to Thread state updates easier.
+ */
+@VisibleForTesting
+public final class ThreadStateListener {
+    private static final List<ThreadStateListener> sListeners = new ArrayList<>();
+    private final ArrayTrackRecord<Integer> mDeviceRoleUpdates = new ArrayTrackRecord<>();
+    private final ArrayTrackRecord<Integer>.ReadHead mReadHead = mDeviceRoleUpdates.newReadHead();
+    private final ThreadNetworkController mController;
+    private final StateCallback mCallback =
+            new ThreadNetworkController.StateCallback() {
+                @Override
+                public void onDeviceRoleChanged(int newRole) {
+                    mDeviceRoleUpdates.add(newRole);
+                }
+                // Add more state update trackers here
+            };
+
+    /** Creates a new {@link ThreadStateListener} object and starts listening for state updates. */
+    public static ThreadStateListener startListener(ThreadNetworkController controller) {
+        var listener = new ThreadStateListener(controller);
+        sListeners.add(listener);
+        listener.start();
+        return listener;
+    }
+
+    /** Stops all listeners created by {@link #startListener}. */
+    public static void stopAllListeners() {
+        for (var listener : sListeners) {
+            listener.stop();
+        }
+        sListeners.clear();
+    }
+
+    private ThreadStateListener(ThreadNetworkController controller) {
+        mController = controller;
+    }
+
+    private void start() {
+        runAsShell(
+                ACCESS_NETWORK_STATE,
+                () -> mController.registerStateCallback(directExecutor(), mCallback));
+    }
+
+    private void stop() {
+        runAsShell(ACCESS_NETWORK_STATE, () -> mController.unregisterStateCallback(mCallback));
+    }
+
+    /**
+     * Polls for any role in {@code roles} starting after call to {@link #startListener}.
+     *
+     * <p>Returns the matched device role or {@code null} if timeout.
+     */
+    @Nullable
+    public Integer pollForAnyRoleOf(List<Integer> roles, Duration timeout) {
+        return mReadHead.poll(timeout.toMillis(), newRole -> (roles.contains(newRole)));
+    }
+}