diff --git a/bpf_progs/bpf_shared.h b/bpf_progs/bpf_shared.h
index c4effa6..dd9fb07 100644
--- a/bpf_progs/bpf_shared.h
+++ b/bpf_progs/bpf_shared.h
@@ -111,7 +111,7 @@
 #define BPF_INGRESS_PROG_PATH BPF_NETD_PATH "prog_netd_cgroupskb_ingress_stats"
 
 #define ASSERT_STRING_EQUAL(s1, s2) \
-  static_assert(std::string_view(s1) == std::string_view(s2), "mismatch vs Android T netd")
+    static_assert(std::string_view(s1) == std::string_view(s2), "mismatch vs Android T netd")
 
 /* -=-=-=-=- WARNING -=-=-=-=-
  *
diff --git a/framework/api/module-lib-current.txt b/framework/api/module-lib-current.txt
index 4ce6add..a2a1ac0 100644
--- a/framework/api/module-lib-current.txt
+++ b/framework/api/module-lib-current.txt
@@ -200,6 +200,8 @@
     method public int describeContents();
     method @NonNull public android.os.ParcelFileDescriptor getFileDescriptor();
     method @NonNull public String getInterfaceName();
+    method @Nullable public android.net.MacAddress getMacAddress();
+    method public int getMtu();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.net.TestNetworkInterface> CREATOR;
   }
diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index a3d3896..f1298ce 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -249,10 +249,10 @@
     method public void onValidationStatus(int, @Nullable android.net.Uri);
     method @NonNull public android.net.Network register();
     method public void sendAddDscpPolicy(@NonNull android.net.DscpPolicy);
-    method public final void sendLinkProperties(@NonNull android.net.LinkProperties);
-    method public final void sendNetworkCapabilities(@NonNull android.net.NetworkCapabilities);
-    method public final void sendNetworkScore(@NonNull android.net.NetworkScore);
-    method public final void sendNetworkScore(@IntRange(from=0, to=99) int);
+    method public void sendLinkProperties(@NonNull android.net.LinkProperties);
+    method public void sendNetworkCapabilities(@NonNull android.net.NetworkCapabilities);
+    method public void sendNetworkScore(@NonNull android.net.NetworkScore);
+    method public void sendNetworkScore(@IntRange(from=0, to=99) int);
     method public final void sendQosCallbackError(int, int);
     method public final void sendQosSessionAvailable(int, int, @NonNull android.net.QosSessionAttributes);
     method public final void sendQosSessionLost(int, int, int);
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index 1b0578f..39cd7f3 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -983,16 +983,6 @@
     public static final int FIREWALL_CHAIN_LOW_POWER_STANDBY = 5;
 
     /**
-     * Firewall chain used for lockdown VPN.
-     * Denylist of apps that cannot receive incoming packets except on loopback because they are
-     * subject to an always-on VPN which is not currently connected.
-     *
-     * @see #BLOCKED_REASON_LOCKDOWN_VPN
-     * @hide
-     */
-    public static final int FIREWALL_CHAIN_LOCKDOWN_VPN = 6;
-
-    /**
      * Firewall chain used for OEM-specific application restrictions.
      * Denylist of apps that will not have network access due to OEM-specific restrictions.
      * @hide
@@ -1024,7 +1014,6 @@
         FIREWALL_CHAIN_POWERSAVE,
         FIREWALL_CHAIN_RESTRICTED,
         FIREWALL_CHAIN_LOW_POWER_STANDBY,
-        FIREWALL_CHAIN_LOCKDOWN_VPN,
         FIREWALL_CHAIN_OEM_DENY_1,
         FIREWALL_CHAIN_OEM_DENY_2,
         FIREWALL_CHAIN_OEM_DENY_3
diff --git a/framework/src/android/net/ITestNetworkManager.aidl b/framework/src/android/net/ITestNetworkManager.aidl
index 27d13c1..d18b931 100644
--- a/framework/src/android/net/ITestNetworkManager.aidl
+++ b/framework/src/android/net/ITestNetworkManager.aidl
@@ -29,8 +29,10 @@
  */
 interface ITestNetworkManager
 {
-    TestNetworkInterface createInterface(boolean isTun, boolean bringUp, in LinkAddress[] addrs,
-            in @nullable String iface);
+    TestNetworkInterface createInterface(boolean isTun, boolean hasCarrier, boolean bringUp,
+            in LinkAddress[] addrs, in @nullable String iface);
+
+    void setCarrierEnabled(in TestNetworkInterface iface, boolean enabled);
 
     void setupTestNetwork(in String iface, in LinkProperties lp, in boolean isMetered,
             in int[] administratorUids, in IBinder binder);
diff --git a/framework/src/android/net/NetworkAgent.java b/framework/src/android/net/NetworkAgent.java
index 5917470..5659a35 100644
--- a/framework/src/android/net/NetworkAgent.java
+++ b/framework/src/android/net/NetworkAgent.java
@@ -913,7 +913,7 @@
      * Must be called by the agent when the network's {@link LinkProperties} change.
      * @param linkProperties the new LinkProperties.
      */
-    public final void sendLinkProperties(@NonNull LinkProperties linkProperties) {
+    public void sendLinkProperties(@NonNull LinkProperties linkProperties) {
         Objects.requireNonNull(linkProperties);
         final LinkProperties lp = new LinkProperties(linkProperties);
         queueOrSendMessage(reg -> reg.sendLinkProperties(lp));
@@ -1088,7 +1088,7 @@
      * Must be called by the agent when the network's {@link NetworkCapabilities} change.
      * @param networkCapabilities the new NetworkCapabilities.
      */
-    public final void sendNetworkCapabilities(@NonNull NetworkCapabilities networkCapabilities) {
+    public void sendNetworkCapabilities(@NonNull NetworkCapabilities networkCapabilities) {
         Objects.requireNonNull(networkCapabilities);
         mBandwidthUpdatePending.set(false);
         mLastBwRefreshTime = System.currentTimeMillis();
@@ -1102,7 +1102,7 @@
      *
      * @param score the new score.
      */
-    public final void sendNetworkScore(@NonNull NetworkScore score) {
+    public void sendNetworkScore(@NonNull NetworkScore score) {
         Objects.requireNonNull(score);
         queueOrSendMessage(reg -> reg.sendScore(score));
     }
@@ -1113,7 +1113,7 @@
      * @param score the new score, between 0 and 99.
      * deprecated use sendNetworkScore(NetworkScore) TODO : remove in S.
      */
-    public final void sendNetworkScore(@IntRange(from = 0, to = 99) int score) {
+    public void sendNetworkScore(@IntRange(from = 0, to = 99) int score) {
         sendNetworkScore(new NetworkScore.Builder().setLegacyInt(score).build());
     }
 
diff --git a/framework/src/android/net/TestNetworkInterface.java b/framework/src/android/net/TestNetworkInterface.java
index 4449ff8..26200e1 100644
--- a/framework/src/android/net/TestNetworkInterface.java
+++ b/framework/src/android/net/TestNetworkInterface.java
@@ -16,22 +16,32 @@
 package android.net;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
+import android.util.Log;
+
+import java.net.NetworkInterface;
+import java.net.SocketException;
 
 /**
- * This class is used to return the interface name and fd of the test interface
+ * This class is used to return the interface name, fd, MAC, and MTU of the test interface
  *
  * @hide
  */
 @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
 public final class TestNetworkInterface implements Parcelable {
+    private static final String TAG = "TestNetworkInterface";
+
     @NonNull
     private final ParcelFileDescriptor mFileDescriptor;
     @NonNull
     private final String mInterfaceName;
+    @Nullable
+    private final MacAddress mMacAddress;
+    private final int mMtu;
 
     @Override
     public int describeContents() {
@@ -40,18 +50,41 @@
 
     @Override
     public void writeToParcel(@NonNull Parcel out, int flags) {
-        out.writeParcelable(mFileDescriptor, PARCELABLE_WRITE_RETURN_VALUE);
+        out.writeParcelable(mFileDescriptor, flags);
         out.writeString(mInterfaceName);
+        out.writeParcelable(mMacAddress, flags);
+        out.writeInt(mMtu);
     }
 
     public TestNetworkInterface(@NonNull ParcelFileDescriptor pfd, @NonNull String intf) {
         mFileDescriptor = pfd;
         mInterfaceName = intf;
+
+        MacAddress macAddress = null;
+        int mtu = 1500;
+        try {
+            // This constructor is called by TestNetworkManager which runs inside the system server,
+            // which has permission to read the MacAddress.
+            NetworkInterface nif = NetworkInterface.getByName(mInterfaceName);
+
+            // getHardwareAddress() returns null for tun interfaces.
+            byte[] hardwareAddress = nif.getHardwareAddress();
+            if (hardwareAddress != null) {
+                macAddress = MacAddress.fromBytes(nif.getHardwareAddress());
+            }
+            mtu = nif.getMTU();
+        } catch (SocketException e) {
+            Log.e(TAG, "Failed to fetch MacAddress or MTU size from NetworkInterface", e);
+        }
+        mMacAddress = macAddress;
+        mMtu = mtu;
     }
 
     private TestNetworkInterface(@NonNull Parcel in) {
         mFileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
         mInterfaceName = in.readString();
+        mMacAddress = in.readParcelable(MacAddress.class.getClassLoader());
+        mMtu = in.readInt();
     }
 
     @NonNull
@@ -64,6 +97,15 @@
         return mInterfaceName;
     }
 
+    @Nullable
+    public MacAddress getMacAddress() {
+        return mMacAddress;
+    }
+
+    public int getMtu() {
+        return mMtu;
+    }
+
     @NonNull
     public static final Parcelable.Creator<TestNetworkInterface> CREATOR =
             new Parcelable.Creator<TestNetworkInterface>() {
diff --git a/framework/src/android/net/TestNetworkManager.java b/framework/src/android/net/TestNetworkManager.java
index 4e78823..7b18765 100644
--- a/framework/src/android/net/TestNetworkManager.java
+++ b/framework/src/android/net/TestNetworkManager.java
@@ -58,6 +58,7 @@
     private static final boolean TAP = false;
     private static final boolean TUN = true;
     private static final boolean BRING_UP = true;
+    private static final boolean CARRIER_UP = true;
     private static final LinkAddress[] NO_ADDRS = new LinkAddress[0];
 
     /** @hide */
@@ -166,7 +167,7 @@
     public TestNetworkInterface createTunInterface(@NonNull Collection<LinkAddress> linkAddrs) {
         try {
             final LinkAddress[] arr = new LinkAddress[linkAddrs.size()];
-            return mService.createInterface(TUN, BRING_UP, linkAddrs.toArray(arr),
+            return mService.createInterface(TUN, CARRIER_UP, BRING_UP, linkAddrs.toArray(arr),
                     null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
@@ -185,7 +186,7 @@
     @NonNull
     public TestNetworkInterface createTapInterface() {
         try {
-            return mService.createInterface(TAP, BRING_UP, NO_ADDRS, null /* iface */);
+            return mService.createInterface(TAP, CARRIER_UP, BRING_UP, NO_ADDRS, null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -204,7 +205,7 @@
     @NonNull
     public TestNetworkInterface createTapInterface(boolean bringUp) {
         try {
-            return mService.createInterface(TAP, bringUp, NO_ADDRS, null /* iface */);
+            return mService.createInterface(TAP, CARRIER_UP, bringUp, NO_ADDRS, null /* iface */);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -226,7 +227,43 @@
     @NonNull
     public TestNetworkInterface createTapInterface(boolean bringUp, @NonNull String iface) {
         try {
-            return mService.createInterface(TAP, bringUp, NO_ADDRS, iface);
+            return mService.createInterface(TAP, CARRIER_UP, bringUp, NO_ADDRS, iface);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Create a tap interface with or without carrier for testing purposes.
+     *
+     * @param carrierUp whether the created interface has a carrier or not.
+     * @param bringUp whether to bring up the interface before returning it.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    @NonNull
+    public TestNetworkInterface createTapInterface(boolean carrierUp, boolean bringUp) {
+        try {
+            return mService.createInterface(TAP, carrierUp, bringUp, NO_ADDRS, null /* iface */);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Enable / disable carrier on TestNetworkInterface
+     *
+     * Note: TUNSETCARRIER is not supported until kernel version 5.0.
+     * TODO: add RequiresApi annotation.
+     *
+     * @param iface the interface to configure.
+     * @param enabled true to turn carrier on, false to turn carrier off.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.MANAGE_TEST_NETWORKS)
+    public void setCarrierEnabled(@NonNull TestNetworkInterface iface, boolean enabled) {
+        try {
+            mService.setCarrierEnabled(iface, enabled);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/service/jni/com_android_server_BpfNetMaps.cpp b/service/jni/com_android_server_BpfNetMaps.cpp
index bc70c93..2780044 100644
--- a/service/jni/com_android_server_BpfNetMaps.cpp
+++ b/service/jni/com_android_server_BpfNetMaps.cpp
@@ -151,6 +151,12 @@
     return (jint)status.code();
 }
 
+static jint native_updateUidLockdownRule(JNIEnv* env, jobject self, jint uid, jboolean add) {
+    Status status = mTc.updateUidLockdownRule(uid, add);
+    CHECK_LOG(status);
+    return (jint)status.code();
+}
+
 static jint native_swapActiveStatsMap(JNIEnv* env, jobject self) {
     Status status = mTc.swapActiveStatsMap();
     CHECK_LOG(status);
@@ -203,6 +209,8 @@
     (void*)native_addUidInterfaceRules},
     {"native_removeUidInterfaceRules", "([I)I",
     (void*)native_removeUidInterfaceRules},
+    {"native_updateUidLockdownRule", "(IZ)I",
+    (void*)native_updateUidLockdownRule},
     {"native_swapActiveStatsMap", "()I",
     (void*)native_swapActiveStatsMap},
     {"native_setPermissionForUids", "(I[I)V",
diff --git a/service/jni/com_android_server_TestNetworkService.cpp b/service/jni/com_android_server_TestNetworkService.cpp
index 4efd0e1..9c7a761 100644
--- a/service/jni/com_android_server_TestNetworkService.cpp
+++ b/service/jni/com_android_server_TestNetworkService.cpp
@@ -51,7 +51,15 @@
     jniThrowException(env, "java/lang/IllegalStateException", msg.c_str());
 }
 
-static int createTunTapInterface(JNIEnv* env, bool isTun, const char* iface) {
+// enable or disable  carrier on tun / tap interface.
+static void setTunTapCarrierEnabledImpl(JNIEnv* env, const char* iface, int tunFd, bool enabled) {
+    uint32_t carrierOn = enabled;
+    if (ioctl(tunFd, TUNSETCARRIER, &carrierOn)) {
+        throwException(env, errno, "set carrier", iface);
+    }
+}
+
+static int createTunTapImpl(JNIEnv* env, bool isTun, bool hasCarrier, const char* iface) {
     base::unique_fd tun(open("/dev/tun", O_RDWR | O_NONBLOCK));
     ifreq ifr{};
 
@@ -63,6 +71,11 @@
         return -1;
     }
 
+    if (!hasCarrier) {
+        // disable carrier before setting IFF_UP
+        setTunTapCarrierEnabledImpl(env, iface, tun.get(), hasCarrier);
+    }
+
     // Activate interface using an unconnected datagram socket.
     base::unique_fd inet6CtrlSock(socket(AF_INET6, SOCK_DGRAM, 0));
     ifr.ifr_flags = IFF_UP;
@@ -79,23 +92,31 @@
 
 //------------------------------------------------------------------------------
 
-static jint create(JNIEnv* env, jobject /* thiz */, jboolean isTun, jstring jIface) {
+static void setTunTapCarrierEnabled(JNIEnv* env, jclass /* clazz */, jstring
+                                    jIface, jint tunFd, jboolean enabled) {
+    ScopedUtfChars iface(env, jIface);
+    if (!iface.c_str()) {
+        jniThrowNullPointerException(env, "iface");
+    }
+    setTunTapCarrierEnabledImpl(env, iface.c_str(), tunFd, enabled);
+}
+
+static jint createTunTap(JNIEnv* env, jclass /* clazz */, jboolean isTun,
+                             jboolean hasCarrier, jstring jIface) {
     ScopedUtfChars iface(env, jIface);
     if (!iface.c_str()) {
         jniThrowNullPointerException(env, "iface");
         return -1;
     }
 
-    int tun = createTunTapInterface(env, isTun, iface.c_str());
-
-    // Any exceptions will be thrown from the createTunTapInterface call
-    return tun;
+    return createTunTapImpl(env, isTun, hasCarrier, iface.c_str());
 }
 
 //------------------------------------------------------------------------------
 
 static const JNINativeMethod gMethods[] = {
-    {"jniCreateTunTap", "(ZLjava/lang/String;)I", (void*)create},
+    {"nativeSetTunTapCarrierEnabled", "(Ljava/lang/String;IZ)V", (void*)setTunTapCarrierEnabled},
+    {"nativeCreateTunTap", "(ZZLjava/lang/String;)I", (void*)createTunTap},
 };
 
 int register_com_android_server_TestNetworkService(JNIEnv* env) {
diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index bce3bb5..adc1925 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -340,8 +340,6 @@
             return ALLOWLIST;
         case LOW_POWER_STANDBY:
             return ALLOWLIST;
-        case LOCKDOWN:
-            return DENYLIST;
         case OEM_DENY_1:
             return DENYLIST;
         case OEM_DENY_2:
@@ -373,9 +371,6 @@
         case LOW_POWER_STANDBY:
             res = updateOwnerMapEntry(LOW_POWER_STANDBY_MATCH, uid, rule, type);
             break;
-        case LOCKDOWN:
-            res = updateOwnerMapEntry(LOCKDOWN_VPN_MATCH, uid, rule, type);
-            break;
         case OEM_DENY_1:
             res = updateOwnerMapEntry(OEM_DENY_1_MATCH, uid, rule, type);
             break;
@@ -447,6 +442,18 @@
     return netdutils::status::ok;
 }
 
+Status TrafficController::updateUidLockdownRule(const uid_t uid, const bool add) {
+    std::lock_guard guard(mMutex);
+
+    netdutils::Status result = add ? addRule(uid, LOCKDOWN_VPN_MATCH)
+                               : removeRule(uid, LOCKDOWN_VPN_MATCH);
+    if (!isOk(result)) {
+        ALOGW("%s Lockdown rule failed(%d): uid=%d",
+              (add ? "add": "remove"), result.code(), uid);
+    }
+    return result;
+}
+
 int TrafficController::replaceUidOwnerMap(const std::string& name, bool isAllowlist __unused,
                                           const std::vector<int32_t>& uids) {
     // FirewallRule rule = isAllowlist ? ALLOW : DENY;
diff --git a/service/native/TrafficControllerTest.cpp b/service/native/TrafficControllerTest.cpp
index f84a910..b77c465 100644
--- a/service/native/TrafficControllerTest.cpp
+++ b/service/native/TrafficControllerTest.cpp
@@ -218,7 +218,7 @@
         checkEachUidValue(uids, match);
     }
 
-    void expectUidOwnerMapValues(const std::vector<uint32_t>& appUids, uint8_t expectedRule,
+    void expectUidOwnerMapValues(const std::vector<uint32_t>& appUids, uint32_t expectedRule,
                                  uint32_t expectedIif) {
         for (uint32_t uid : appUids) {
             Result<UidOwnerValue> value = mFakeUidOwnerMap.readValue(uid);
@@ -407,7 +407,6 @@
     checkUidOwnerRuleForChain(POWERSAVE, POWERSAVE_MATCH);
     checkUidOwnerRuleForChain(RESTRICTED, RESTRICTED_MATCH);
     checkUidOwnerRuleForChain(LOW_POWER_STANDBY, LOW_POWER_STANDBY_MATCH);
-    checkUidOwnerRuleForChain(LOCKDOWN, LOCKDOWN_VPN_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_1, OEM_DENY_1_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_2, OEM_DENY_2_MATCH);
     checkUidOwnerRuleForChain(OEM_DENY_3, OEM_DENY_3_MATCH);
@@ -539,6 +538,21 @@
     expectMapEmpty(mFakeUidOwnerMap);
 }
 
+TEST_F(TrafficControllerTest, TestUpdateUidLockdownRule) {
+    // Add Lockdown rules
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1000, true /* add */)));
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1001, true /* add */)));
+    expectUidOwnerMapValues({1000, 1001}, LOCKDOWN_VPN_MATCH, 0);
+
+    // Remove one of Lockdown rules
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1000, false /* add */)));
+    expectUidOwnerMapValues({1001}, LOCKDOWN_VPN_MATCH, 0);
+
+    // Remove remaining Lockdown rule
+    ASSERT_TRUE(isOk(mTc.updateUidLockdownRule(1001, false /* add */)));
+    expectMapEmpty(mFakeUidOwnerMap);
+}
+
 TEST_F(TrafficControllerTest, TestUidInterfaceFilteringRulesCoexistWithExistingMatches) {
     // Set up existing PENALTY_BOX_MATCH rules
     ASSERT_TRUE(isOk(updateUidOwnerMaps({1000, 1001, 10012}, PENALTY_BOX_MATCH,
@@ -885,7 +899,6 @@
             {POWERSAVE, ALLOWLIST},
             {RESTRICTED, ALLOWLIST},
             {LOW_POWER_STANDBY, ALLOWLIST},
-            {LOCKDOWN, DENYLIST},
             {OEM_DENY_1, DENYLIST},
             {OEM_DENY_2, DENYLIST},
             {OEM_DENY_3, DENYLIST},
diff --git a/service/native/include/Common.h b/service/native/include/Common.h
index 2427aa9..3f28991 100644
--- a/service/native/include/Common.h
+++ b/service/native/include/Common.h
@@ -35,7 +35,6 @@
     POWERSAVE = 3,
     RESTRICTED = 4,
     LOW_POWER_STANDBY = 5,
-    LOCKDOWN = 6,
     OEM_DENY_1 = 7,
     OEM_DENY_2 = 8,
     OEM_DENY_3 = 9,
diff --git a/service/native/include/TrafficController.h b/service/native/include/TrafficController.h
index c019ce7..c921ff2 100644
--- a/service/native/include/TrafficController.h
+++ b/service/native/include/TrafficController.h
@@ -71,6 +71,8 @@
             EXCLUDES(mMutex);
     netdutils::Status removeUidInterfaceRules(const std::vector<int32_t>& uids) EXCLUDES(mMutex);
 
+    netdutils::Status updateUidLockdownRule(const uid_t uid, const bool add) EXCLUDES(mMutex);
+
     netdutils::Status updateUidOwnerMap(const uint32_t uid,
                                         UidOwnerMatchType matchType, IptOp op) EXCLUDES(mMutex);
 
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index c006bc6..151d0e3 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -216,6 +216,19 @@
     }
 
     /**
+     * Update lockdown rule for uid
+     *
+     * @param  uid          target uid to add/remove the rule
+     * @param  add          {@code true} to add the rule, {@code false} to remove the rule.
+     * @throws ServiceSpecificException in case of failure, with an error code indicating the
+     *                                  cause of the failure.
+     */
+    public void updateUidLockdownRule(final int uid, final boolean add) {
+        final int err = native_updateUidLockdownRule(uid, add);
+        maybeThrow(err, "Unable to update lockdown rule");
+    }
+
+    /**
      * Request netd to change the current active network stats map.
      *
      * @throws ServiceSpecificException in case of failure, with an error code indicating the
@@ -271,6 +284,7 @@
     private native int native_setUidRule(int childChain, int uid, int firewallRule);
     private native int native_addUidInterfaceRules(String ifName, int[] uids);
     private native int native_removeUidInterfaceRules(int[] uids);
+    private native int native_updateUidLockdownRule(int uid, boolean add);
     private native int native_swapActiveStatsMap();
     private native void native_setPermissionForUids(int permissions, int[] uids);
     private native void native_dump(FileDescriptor fd, boolean verbose);
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 848901f..853a1a2 100644
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -7760,10 +7760,6 @@
         // when the old rules are removed and the time when new rules are added. To fix this,
         // make eBPF support two allowlisted interfaces so here new rules can be added before the
         // old rules are being removed.
-
-        // Null iface given to onVpnUidRangesAdded/Removed is a wildcard to allow apps to receive
-        // packets on all interfaces. This is required to accept incoming traffic in Lockdown mode
-        // by overriding the Lockdown blocking rule.
         if (wasFiltering) {
             mPermissionMonitor.onVpnUidRangesRemoved(oldIface, ranges, vpnAppUid);
         }
@@ -8089,12 +8085,14 @@
      * Returns whether we need to set interface filtering rule or not
      */
     private boolean requiresVpnAllowRule(NetworkAgentInfo nai, LinkProperties lp,
-            String filterIface) {
-        // Only filter if lp has an interface.
-        if (lp == null || lp.getInterfaceName() == null) return false;
-        // Before T, allow rules are only needed if VPN isolation is enabled.
-        // T and After T, allow rules are needed for all VPNs.
-        return filterIface != null || (nai.isVPN() && SdkLevel.isAtLeastT());
+            String isolationIface) {
+        // Allow rules are always needed if VPN isolation is enabled.
+        if (isolationIface != null) return true;
+
+        // On T and above, allow rules are needed for all VPNs. Allow rule with null iface is a
+        // wildcard to allow apps to receive packets on all interfaces. This is required to accept
+        // incoming traffic in Lockdown mode by overriding the Lockdown blocking rule.
+        return SdkLevel.isAtLeastT() && nai.isVPN() && lp != null && lp.getInterfaceName() != null;
     }
 
     private static UidRangeParcel[] toUidRangeStableParcels(final @NonNull Set<UidRange> ranges) {
@@ -8237,10 +8235,6 @@
             // above, where the addition of new ranges happens before the removal of old ranges.
             // TODO Fix this window by computing an accurate diff on Set<UidRange>, so the old range
             // to be removed will never overlap with the new range to be added.
-
-            // Null iface given to onVpnUidRangesAdded/Removed is a wildcard to allow apps to
-            // receive packets on all interfaces. This is required to accept incoming traffic in
-            // Lockdown mode by overriding the Lockdown blocking rule.
             if (wasFiltering && !prevRanges.isEmpty()) {
                 mPermissionMonitor.onVpnUidRangesRemoved(oldIface, prevRanges,
                         prevNc.getOwnerUid());
diff --git a/service/src/com/android/server/TestNetworkService.java b/service/src/com/android/server/TestNetworkService.java
index e12190c..1209579 100644
--- a/service/src/com/android/server/TestNetworkService.java
+++ b/service/src/com/android/server/TestNetworkService.java
@@ -50,6 +50,7 @@
 import com.android.net.module.util.NetdUtils;
 import com.android.net.module.util.NetworkStackConstants;
 
+import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
@@ -76,7 +77,11 @@
     @NonNull private final NetworkProvider mNetworkProvider;
 
     // Native method stubs
-    private static native int jniCreateTunTap(boolean isTun, @NonNull String iface);
+    private static native int nativeCreateTunTap(boolean isTun, boolean hasCarrier,
+            @NonNull String iface);
+
+    private static native void nativeSetTunTapCarrierEnabled(@NonNull String iface, int tunFd,
+            boolean enabled);
 
     @VisibleForTesting
     protected TestNetworkService(@NonNull Context context) {
@@ -114,7 +119,7 @@
      * interface.
      */
     @Override
-    public TestNetworkInterface createInterface(boolean isTun, boolean bringUp,
+    public TestNetworkInterface createInterface(boolean isTun, boolean hasCarrier, boolean bringUp,
             LinkAddress[] linkAddrs, @Nullable String iface) {
         enforceTestNetworkPermissions(mContext);
 
@@ -130,8 +135,8 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            ParcelFileDescriptor tunIntf =
-                    ParcelFileDescriptor.adoptFd(jniCreateTunTap(isTun, interfaceName));
+            ParcelFileDescriptor tunIntf = ParcelFileDescriptor.adoptFd(
+                    nativeCreateTunTap(isTun, hasCarrier, interfaceName));
             for (LinkAddress addr : linkAddrs) {
                 mNetd.interfaceAddAddress(
                         interfaceName,
@@ -375,4 +380,20 @@
     public static void enforceTestNetworkPermissions(@NonNull Context context) {
         context.enforceCallingOrSelfPermission(PERMISSION_NAME, "TestNetworkService");
     }
+
+    /** Enable / disable TestNetworkInterface carrier */
+    @Override
+    public void setCarrierEnabled(@NonNull TestNetworkInterface iface, boolean enabled) {
+        enforceTestNetworkPermissions(mContext);
+        nativeSetTunTapCarrierEnabled(iface.getInterfaceName(), iface.getFileDescriptor().getFd(),
+                enabled);
+        // Explicitly close fd after use to prevent StrictMode from complaining.
+        // Also, explicitly referencing iface guarantees that the object is not garbage collected
+        // before nativeSetTunTapCarrierEnabled() executes.
+        try {
+            iface.getFileDescriptor().close();
+        } catch (IOException e) {
+            // if the close fails, there is not much that can be done -- move on.
+        }
+    }
 }
diff --git a/service/src/com/android/server/connectivity/PermissionMonitor.java b/service/src/com/android/server/connectivity/PermissionMonitor.java
index e4a2c20..dedeb38 100755
--- a/service/src/com/android/server/connectivity/PermissionMonitor.java
+++ b/service/src/com/android/server/connectivity/PermissionMonitor.java
@@ -23,9 +23,6 @@
 import static android.Manifest.permission.UPDATE_DEVICE_STATS;
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
-import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
-import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.net.ConnectivitySettingsManager.UIDS_ALLOWED_ON_RESTRICTED_NETWORKS;
 import static android.net.INetd.PERMISSION_INTERNET;
 import static android.net.INetd.PERMISSION_NETWORK;
@@ -684,8 +681,12 @@
     }
 
     private synchronized void updateLockdownUid(int uid, boolean add) {
-        if (UidRange.containsUid(mVpnLockdownUidRanges.getSet(), uid)
-                && !hasRestrictedNetworksPermission(uid)) {
+        // Apps that can use restricted networks can always bypass VPNs.
+        if (hasRestrictedNetworksPermission(uid)) {
+            return;
+        }
+
+        if (UidRange.containsUid(mVpnLockdownUidRanges.getSet(), uid)) {
             updateLockdownUidRule(uid, add);
         }
     }
@@ -1079,11 +1080,7 @@
 
     private void updateLockdownUidRule(int uid, boolean add) {
         try {
-            if (add) {
-                mBpfNetMaps.setUidRule(FIREWALL_CHAIN_LOCKDOWN_VPN, uid, FIREWALL_RULE_DENY);
-            } else {
-                mBpfNetMaps.setUidRule(FIREWALL_CHAIN_LOCKDOWN_VPN, uid, FIREWALL_RULE_ALLOW);
-            }
+            mBpfNetMaps.updateUidLockdownRule(uid, add);
         } catch (ServiceSpecificException e) {
             loge("Failed to " + (add ? "add" : "remove") + " Lockdown rule: " + e);
         }
@@ -1259,7 +1256,7 @@
         pw.println("Lockdown filtering rules:");
         pw.increaseIndent();
         for (final UidRange range : mVpnLockdownUidRanges.getSet()) {
-            pw.println("UIDs: " + range.toString());
+            pw.println("UIDs: " + range);
         }
         pw.decreaseIndent();
 
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index e84df16..900ee5a 100644
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -52,7 +52,6 @@
 import static android.net.ConnectivityManager.EXTRA_NETWORK_INFO;
 import static android.net.ConnectivityManager.EXTRA_NETWORK_TYPE;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_DOZABLE;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOW_POWER_STANDBY;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_1;
 import static android.net.ConnectivityManager.FIREWALL_CHAIN_OEM_DENY_2;
@@ -9516,38 +9515,28 @@
 
     @Test @IgnoreUpTo(Build.VERSION_CODES.S_V2)
     public void testLockdownSetFirewallUidRule() throws Exception {
-        // For ConnectivityService#setAlwaysOnVpnPackage.
-        mServiceContext.setPermission(
-                Manifest.permission.CONTROL_ALWAYS_ON_VPN, PERMISSION_GRANTED);
-        // Needed to call Vpn#setAlwaysOnPackage.
-        mServiceContext.setPermission(Manifest.permission.CONTROL_VPN, PERMISSION_GRANTED);
-        // Needed to call Vpn#isAlwaysOnPackageSupported.
-        mServiceContext.setPermission(NETWORK_SETTINGS, PERMISSION_GRANTED);
-
+        final Set<Range<Integer>> lockdownRange = UidRange.toIntRanges(Set.of(PRIMARY_UIDRANGE));
         // Enable Lockdown
-        final ArrayList<String> allowList = new ArrayList<>();
-        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, ALWAYS_ON_PACKAGE,
-                true /* lockdown */, allowList);
+        mCm.setRequireVpnForUids(true /* requireVpn */, lockdownRange);
         waitForIdle();
 
         // Lockdown rule is set to apps uids
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_DENY));
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_DENY));
+        verify(mBpfNetMaps, times(3)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP1_UID, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP2_UID, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, true /* add */);
 
         reset(mBpfNetMaps);
 
         // Disable lockdown
-        mVpnManagerService.setAlwaysOnVpnPackage(PRIMARY_USER, null, false /* lockdown */,
-                allowList);
+        mCm.setRequireVpnForUids(false /* requireVPN */, lockdownRange);
         waitForIdle();
 
         // Lockdown rule is removed from apps uids
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP1_UID), eq(FIREWALL_RULE_ALLOW));
-        verify(mBpfNetMaps).setUidRule(
-                eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(APP2_UID), eq(FIREWALL_RULE_ALLOW));
+        verify(mBpfNetMaps, times(3)).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP1_UID, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(APP2_UID, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, false /* add */);
 
         // Interface rules are not changed by Lockdown mode enable/disable
         verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
@@ -10528,27 +10517,28 @@
         assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges("tun0"));
     }
 
-    @Test
-    public void testLegacyVpnInterfaceFilteringRule() throws Exception {
-        LinkProperties lp = new LinkProperties();
-        lp.setInterfaceName("tun0");
-        lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
-        lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
+    private void checkInterfaceFilteringRuleWithNullInterface(final LinkProperties lp,
+            final int uid) throws Exception {
         // The uid range needs to cover the test app so the network is visible to it.
         final Set<UidRange> vpnRange = Collections.singleton(PRIMARY_UIDRANGE);
-        mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
-        assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
+        mMockVpn.establish(lp, uid, vpnRange);
+        assertVpnUidRangesUpdated(true, vpnRange, uid);
 
         if (SdkLevel.isAtLeastT()) {
-            // On T and above, A connected Legacy VPN should have interface rules with null
-            // interface. Null Interface is a wildcard and this accepts traffic from all the
-            // interfaces. There are two expected invocations, one during the VPN initial
+            // On T and above, VPN should have rules for null interface. Null Interface is a
+            // wildcard and this accepts traffic from all the interfaces.
+            // There are two expected invocations, one during the VPN initial
             // connection, one during the VPN LinkProperties update.
             ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
             verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
                     eq(null) /* iface */, uidCaptor.capture());
-            assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
-            assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
+            if (uid == VPN_UID) {
+                assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID);
+                assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID);
+            } else {
+                assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
+                assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
+            }
             assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
                     vpnRange);
 
@@ -10557,50 +10547,37 @@
 
             // Disconnected VPN should have interface rules removed
             verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
-            assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
+            if (uid == VPN_UID) {
+                assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID);
+            } else {
+                assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
+            }
             assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
         } else {
-            // Before T, Legacy VPN should not have interface rules.
+            // Before T, rules are not configured for null interface.
             verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
         }
     }
 
     @Test
+    public void testLegacyVpnInterfaceFilteringRule() throws Exception {
+        LinkProperties lp = new LinkProperties();
+        lp.setInterfaceName("tun0");
+        lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), null));
+        lp.addRoute(new RouteInfo(new IpPrefix(Inet4Address.ANY, 0), null));
+        // Legacy VPN should have interface filtering with null interface.
+        checkInterfaceFilteringRuleWithNullInterface(lp, Process.SYSTEM_UID);
+    }
+
+    @Test
     public void testLocalIpv4OnlyVpnInterfaceFilteringRule() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");
         lp.addRoute(new RouteInfo(new IpPrefix("192.0.2.0/24"), null, "tun0"));
         lp.addRoute(new RouteInfo(new IpPrefix(Inet6Address.ANY, 0), RTN_UNREACHABLE));
-        // The uid range needs to cover the test app so the network is visible to it.
-        final Set<UidRange> vpnRange = Collections.singleton(PRIMARY_UIDRANGE);
-        mMockVpn.establish(lp, Process.SYSTEM_UID, vpnRange);
-        assertVpnUidRangesUpdated(true, vpnRange, Process.SYSTEM_UID);
-
-        if (SdkLevel.isAtLeastT()) {
-            // IPv6 unreachable route should not be misinterpreted as a default route
-            // On T and above, A connected VPN that does not provide a default route should have
-            // interface rules with null interface. Null Interface is a wildcard and this accepts
-            // traffic from all the interfaces. There are two expected invocations, one during the
-            // VPN initial connection, one during the VPN LinkProperties update.
-            ArgumentCaptor<int[]> uidCaptor = ArgumentCaptor.forClass(int[].class);
-            verify(mBpfNetMaps, times(2)).addUidInterfaceRules(
-                    eq(null) /* iface */, uidCaptor.capture());
-            assertContainsExactly(uidCaptor.getAllValues().get(0), APP1_UID, APP2_UID, VPN_UID);
-            assertContainsExactly(uidCaptor.getAllValues().get(1), APP1_UID, APP2_UID, VPN_UID);
-            assertEquals(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */),
-                    vpnRange);
-
-            mMockVpn.disconnect();
-            waitForIdle();
-
-            // Disconnected VPN should have interface rules removed
-            verify(mBpfNetMaps).removeUidInterfaceRules(uidCaptor.capture());
-            assertContainsExactly(uidCaptor.getValue(), APP1_UID, APP2_UID, VPN_UID);
-            assertNull(mService.mPermissionMonitor.getVpnInterfaceUidRanges(null /* iface */));
-        } else {
-            // Before T, VPN with IPv6 unreachable route should not have interface rules.
-            verify(mBpfNetMaps, never()).addUidInterfaceRules(any(), any());
-        }
+        // VPN that does not provide a default route should have interface filtering with null
+        // interface.
+        checkInterfaceFilteringRuleWithNullInterface(lp, VPN_UID);
     }
 
     @Test
diff --git a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
index ecd17ba..354e79a 100644
--- a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
+++ b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
@@ -30,9 +30,6 @@
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_REQUIRED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 import static android.content.pm.PackageManager.MATCH_ANY_USER;
-import static android.net.ConnectivityManager.FIREWALL_CHAIN_LOCKDOWN_VPN;
-import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
-import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
 import static android.net.ConnectivitySettingsManager.UIDS_ALLOWED_ON_RESTRICTED_NETWORKS;
 import static android.net.INetd.PERMISSION_INTERNET;
 import static android.net.INetd.PERMISSION_NETWORK;
@@ -698,7 +695,8 @@
         mNetdMonitor.expectNetworkPerm(PERMISSION_SYSTEM, new UserHandle[]{MOCK_USER1},
                 SYSTEM_APPID1);
 
-        final List<PackageInfo> pkgs = List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID21,
+        final List<PackageInfo> pkgs = List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID21,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, SYSTEM_APP_UID21, CHANGE_NETWORK_STATE));
         doReturn(pkgs).when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS),
@@ -764,9 +762,10 @@
                 MOCK_APPID1);
     }
 
-    private void doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates(@Nullable String ifName)
+    private void doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates(@Nullable String ifName)
             throws Exception {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12),
@@ -774,7 +773,7 @@
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         buildAndMockPackageInfoWithPermissions(MOCK_PACKAGE1, MOCK_UID11);
         mPermissionMonitor.startMonitoring();
-        // Every app on user 0 except MOCK_UID12 are under VPN.
+        // Every app on user 0 except MOCK_UID12 is subject to the VPN.
         final Set<UidRange> vpnRange1 = Set.of(
                 new UidRange(0, MOCK_UID12 - 1),
                 new UidRange(MOCK_UID12 + 1, UserHandle.PER_USER_RANGE - 1));
@@ -811,18 +810,19 @@
 
     @Test
     public void testUidFilteringDuringVpnConnectDisconnectAndUidUpdates() throws Exception {
-        doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates("tun0");
+        doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates("tun0");
     }
 
     @Test
     public void testUidFilteringDuringVpnConnectDisconnectAndUidUpdatesWithWildcard()
             throws Exception {
-        doTestuidFilteringDuringVpnConnectDisconnectAndUidUpdates(null /* ifName */);
+        doTestUidFilteringDuringVpnConnectDisconnectAndUidUpdates(null /* ifName */);
     }
 
     private void doTestUidFilteringDuringPackageInstallAndUninstall(@Nullable String ifName) throws
             Exception {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         NETWORK_STACK, CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
@@ -857,155 +857,149 @@
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisable() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // Every app on user 0 except MOCK_UID12 are under VPN.
-        final UidRange[] vpnRange1 = {
+        // Every app on user 0 except MOCK_UID12 is subject to the VPN.
+        final UidRange[] lockdownRange = {
                 new UidRange(0, MOCK_UID12 - 1),
                 new UidRange(MOCK_UID12 + 1, UserHandle.PER_USER_RANGE - 1)
         };
 
-        // Add Lockdown uid range, expect a rule to be set up for user app MOCK_UID11
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange1);
-        verify(mBpfNetMaps)
-                .setUidRule(
-                        eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange1));
+        // Add Lockdown uid range, expect a rule to be set up for MOCK_UID11 and VPN_UID
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range, expect rules to be torn down
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange1);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(VPN_UID, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisableWithMultiAdd() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // MOCK_UID11 is under VPN.
+        // MOCK_UID11 is subject to the VPN.
         final UidRange range = new UidRange(MOCK_UID11, MOCK_UID11);
-        final UidRange[] vpnRange = {range};
+        final UidRange[] lockdownRange = {range};
 
         // Add Lockdown uid range at 1st time, expect a rule to be set up
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Add Lockdown uid range at 2nd time, expect a rule not to be set up because the uid
         // already has the rule
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(),  anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 1st time, expect a rule not to be torn down because we added
         // the range 2 times.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(),  anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 2nd time, expect a rule to be torn down because we added
         // twice and we removed twice.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithLockdownEnableDisableWithDuplicates() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
-        // MOCK_UID11 is under VPN.
+        // MOCK_UID11 is subject to the VPN.
         final UidRange range = new UidRange(MOCK_UID11, MOCK_UID11);
-        final UidRange[] vpnRangeDuplicates = {range, range};
-        final UidRange[] vpnRange = {range};
+        final UidRange[] lockdownRangeDuplicates = {range, range};
+        final UidRange[] lockdownRange = {range};
 
         // Add Lockdown uid ranges which contains duplicated uid ranges
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRangeDuplicates);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRangeDuplicates);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 1st time, expect a rule not to be torn down because uid
         // ranges we added contains duplicated uid ranges.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps, never()).setUidRule(anyInt(), anyInt(), anyInt());
-        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(vpnRange));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps, never()).updateUidLockdownRule(anyInt(), anyBoolean());
+        assertEquals(mPermissionMonitor.getVpnLockdownUidRanges(), Set.of(lockdownRange));
 
         reset(mBpfNetMaps);
 
         // Remove Lockdown uid range at 2nd time, expect a rule to be torn down.
-        mPermissionMonitor.updateVpnLockdownUidRanges(false /* false */, vpnRange);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
+        mPermissionMonitor.updateVpnLockdownUidRanges(false /* add */, lockdownRange);
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
         assertTrue(mPermissionMonitor.getVpnLockdownUidRanges().isEmpty());
     }
 
     @Test
     public void testLockdownUidFilteringWithInstallAndUnInstall() {
-        doReturn(List.of(buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
+        doReturn(List.of(
+                buildPackageInfo(SYSTEM_PACKAGE1, SYSTEM_APP_UID11, CHANGE_NETWORK_STATE,
                         NETWORK_STACK, CONNECTIVITY_USE_RESTRICTED_NETWORKS),
                 buildPackageInfo(SYSTEM_PACKAGE2, VPN_UID)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         doReturn(List.of(MOCK_USER1, MOCK_USER2)).when(mUserManager).getUserHandles(eq(true));
 
         mPermissionMonitor.startMonitoring();
-        final UidRange[] vpnRange = {
+        final UidRange[] lockdownRange = {
                 UidRange.createForUser(MOCK_USER1),
                 UidRange.createForUser(MOCK_USER2)
         };
-        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, vpnRange);
+        mPermissionMonitor.updateVpnLockdownUidRanges(true /* add */, lockdownRange);
+
+        reset(mBpfNetMaps);
 
         // Installing package should add Lockdown rules
         addPackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2}, MOCK_PACKAGE1, MOCK_APPID1);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_DENY));
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID21),
-                        eq(FIREWALL_RULE_DENY));
+        verify(mBpfNetMaps, times(2)).updateUidLockdownRule(anyInt(), eq(true) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, true /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID21, true /* add */);
 
         reset(mBpfNetMaps);
 
         // Uninstalling package should remove Lockdown rules
         mPermissionMonitor.onPackageRemoved(MOCK_PACKAGE1, MOCK_UID11);
-        verify(mBpfNetMaps)
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID11),
-                        eq(FIREWALL_RULE_ALLOW));
-        verify(mBpfNetMaps, never())
-                .setUidRule(eq(FIREWALL_CHAIN_LOCKDOWN_VPN), eq(MOCK_UID21),
-                        eq(FIREWALL_RULE_ALLOW));
+        verify(mBpfNetMaps).updateUidLockdownRule(anyInt(), eq(false) /* add */);
+        verify(mBpfNetMaps).updateUidLockdownRule(MOCK_UID11, false /* add */);
     }
 
     // Normal package add/remove operations will trigger multiple intent for uids corresponding to
@@ -1329,7 +1323,8 @@
     public void testOnExternalApplicationsAvailable() throws Exception {
         // Initial the permission state. MOCK_PACKAGE1 and MOCK_PACKAGE2 are installed on external
         // and have different uids. There has no permission for both uids.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID12)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
@@ -1387,7 +1382,8 @@
             throws Exception {
         // Initial the permission state. MOCK_PACKAGE1 and MOCK_PACKAGE2 are installed on external
         // storage and shared on MOCK_UID11. There has no permission for MOCK_UID11.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID11)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();
@@ -1413,7 +1409,8 @@
         // Initial the permission state. MOCK_PACKAGE1 is installed on external storage and
         // MOCK_PACKAGE2 is installed on device. These two packages are shared on MOCK_UID11.
         // MOCK_UID11 has NETWORK and INTERNET permissions.
-        doReturn(List.of(buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
+        doReturn(List.of(
+                buildPackageInfo(MOCK_PACKAGE1, MOCK_UID11),
                 buildPackageInfo(MOCK_PACKAGE2, MOCK_UID11, CHANGE_NETWORK_STATE, INTERNET)))
                 .when(mPackageManager).getInstalledPackagesAsUser(eq(GET_PERMISSIONS), anyInt());
         mPermissionMonitor.startMonitoring();