Merge changes from topic "tetherlocalagent" into main

* changes:
  Add integration test of tethering local network agent feature
  Add unit test of tethering local network agent feature
  Support LocalNetworkAgent for Tethering

Tethering/src/android/net/ip/IpServer.java

@@ -31,6 +31,7 @@ import static android.net.TetheringManager.TETHER_ERROR_ENABLE_FORWARDING_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_IFACE_CFG_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_INTERNAL_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_SERVICE_UNAVAIL;
 import static android.net.TetheringManager.TETHER_ERROR_TETHER_IFACE_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_UNTETHER_IFACE_ERROR;
 import static android.net.TetheringManager.TetheringRequest.checkStaticAddressConfiguration;
@@ -40,19 +41,25 @@ import static android.system.OsConstants.RT_SCOPE_UNIVERSE;
 
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
+import static com.android.networkstack.tethering.TetheringConfiguration.TETHERING_LOCAL_NETWORK_AGENT;
 import static com.android.networkstack.tethering.TetheringConfiguration.USE_SYNC_SM;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 import static com.android.networkstack.tethering.util.TetheringMessageBase.BASE_IPSERVER;
+import static com.android.networkstack.tethering.util.TetheringUtils.getTransportTypeForTetherableType;
 
+import android.annotation.SuppressLint;
+import android.content.Context;
 import android.net.INetd;
 import android.net.INetworkStackStatusCallback;
 import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.MacAddress;
+import android.net.NetworkAgent;
 import android.net.RouteInfo;
 import android.net.TetheredClient;
 import android.net.TetheringManager.TetheringRequest;
+import android.net.connectivity.ConnectivityInternalApiUtil;
 import android.net.dhcp.DhcpLeaseParcelable;
 import android.net.dhcp.DhcpServerCallbacks;
 import android.net.dhcp.DhcpServingParamsParcel;
@@ -60,7 +67,9 @@ import android.net.dhcp.DhcpServingParamsParcelExt;
 import android.net.dhcp.IDhcpEventCallbacks;
 import android.net.dhcp.IDhcpServer;
 import android.net.ip.RouterAdvertisementDaemon.RaParams;
+import android.os.Build;
 import android.os.Handler;
+import android.os.Looper;
 import android.os.Message;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
@@ -70,11 +79,13 @@ import android.util.SparseArray;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.MessageUtils;
 import com.android.internal.util.State;
 import com.android.modules.utils.build.SdkLevel;
+import com.android.net.module.util.DeviceConfigUtils;
 import com.android.net.module.util.IIpv4PrefixRequest;
 import com.android.net.module.util.InterfaceParams;
 import com.android.net.module.util.NetdUtils;
@@ -204,6 +215,23 @@ public class IpServer extends StateMachineShim {
         /** Create a DhcpServer instance to be used by IpServer. */
         public abstract void makeDhcpServer(String ifName, DhcpServingParamsParcel params,
                 DhcpServerCallbacks cb);
+
+        /**
+         * @see DeviceConfigUtils#isTetheringFeatureEnabled
+         */
+        public boolean isFeatureEnabled(Context context, String name) {
+            return DeviceConfigUtils.isTetheringFeatureEnabled(context, name);
+        }
+
+        /** Create a NetworkAgent instance to be used by IpServer. */
+        @RequiresApi(Build.VERSION_CODES.VANILLA_ICE_CREAM)
+        @SuppressLint("NewApi")
+        public NetworkAgent makeNetworkAgent(
+                @NonNull Context context, @NonNull Looper looper, @NonNull String logTag,
+                int interfaceType, @NonNull LinkProperties lp) {
+            return ConnectivityInternalApiUtil.buildTetheringNetworkAgent(
+                    context, looper, logTag, getTransportTypeForTetherableType(interfaceType), lp);
+        }
     }
 
     // request from the user that it wants to tether
@@ -304,16 +332,28 @@ public class IpServer extends StateMachineShim {
 
     private final TetheringMetrics mTetheringMetrics;
     private final Handler mHandler;
+    private final Context mContext;
+
+    private final boolean mSupportLocalAgent;
+
+    // This will be null if the TetheredState is not entered or feature not supported.
+    // This will be only accessed from the IpServer handler thread.
+    private NetworkAgent mTetheringAgent;
+
+    private static boolean everRegistered(@NonNull NetworkAgent agent) {
+        return agent.getNetwork() != null;
+    }
 
     // TODO: Add a dependency object to pass the data members or variables from the tethering
     // object. It helps to reduce the arguments of the constructor.
     public IpServer(
-            String ifaceName, Handler handler, int interfaceType, SharedLog log,
+            String ifaceName, @NonNull Context context, Handler handler, int interfaceType,
-            INetd netd, @NonNull BpfCoordinator bpfCoordinator,
+            SharedLog log, INetd netd, @NonNull BpfCoordinator bpfCoordinator,
             RoutingCoordinatorManager routingCoordinatorManager, Callback callback,
             TetheringConfiguration config,
             TetheringMetrics tetheringMetrics, Dependencies deps) {
         super(ifaceName, USE_SYNC_SM ? null : handler.getLooper());
+        mContext = Objects.requireNonNull(context);
         mHandler = handler;
         mLog = log.forSubComponent(ifaceName);
         mNetd = netd;
@@ -339,6 +379,10 @@ public class IpServer extends StateMachineShim {
         mLastError = TETHER_ERROR_NO_ERROR;
         mServingMode = STATE_AVAILABLE;
 
+        // Tethering network agent is supported on V+, and will be rolled out gradually.
+        mSupportLocalAgent = SdkLevel.isAtLeastV()
+                && mDeps.isFeatureEnabled(mContext, TETHERING_LOCAL_NETWORK_AGENT);
+
         mInitialState = new InitialState();
         mLocalHotspotState = new LocalHotspotState();
         mTetheredState = new TetheredState();
@@ -787,6 +831,7 @@ public class IpServer extends StateMachineShim {
     //
     // TODO: Evaluate using a data structure than is more directly suited to
     // communicating only the relevant information.
+    @SuppressLint("NewApi")
     private void updateUpstreamIPv6LinkProperties(LinkProperties v6only, int ttlAdjustment) {
         if (mRaDaemon == null) return;
 
@@ -847,8 +892,7 @@ public class IpServer extends StateMachineShim {
     }
 
     private void removeRoutesFromNetwork(int netId, @NonNull final List<RouteInfo> toBeRemoved) {
-        final int removalFailures = NetdUtils.removeRoutesFromNetwork(
+        final int removalFailures = NetdUtils.removeRoutesFromNetwork(mNetd, netId, toBeRemoved);
-                mNetd, netId, toBeRemoved);
         if (removalFailures > 0) {
             mLog.e("Failed to remove " + removalFailures
                     + " IPv6 routes from network " + netId + ".");
@@ -900,7 +944,9 @@ public class IpServer extends StateMachineShim {
         if (!deprecatedPrefixes.isEmpty()) {
             final List<RouteInfo> routesToBeRemoved =
                     getLocalRoutesFor(mIfaceName, deprecatedPrefixes);
-            removeRoutesFromNetwork(LOCAL_NET_ID, routesToBeRemoved);
+            if (mTetheringAgent == null) {
+                removeRoutesFromNetwork(LOCAL_NET_ID, routesToBeRemoved);
+            }
             for (RouteInfo route : routesToBeRemoved) mLinkProperties.removeRoute(route);
         }
 
@@ -914,7 +960,9 @@ public class IpServer extends StateMachineShim {
             if (!addedPrefixes.isEmpty()) {
                 final List<RouteInfo> routesToBeAdded =
                         getLocalRoutesFor(mIfaceName, addedPrefixes);
-                addRoutesToNetwork(LOCAL_NET_ID, routesToBeAdded);
+                if (mTetheringAgent == null) {
+                    addRoutesToNetwork(LOCAL_NET_ID, routesToBeAdded);
+                }
                 for (RouteInfo route : routesToBeAdded) mLinkProperties.addRoute(route);
             }
         }
@@ -1112,7 +1160,26 @@ public class IpServer extends StateMachineShim {
             return CONNECTIVITY_SCOPE_LOCAL;
         }
 
+        @SuppressLint("NewApi")
         private void startServingInterface() {
+            // TODO: Enable Network Agent for Wifi P2P Group Owner mode when Network Agent
+            //  for Group Client mode is supported.
+            if (mSupportLocalAgent && getScope() == CONNECTIVITY_SCOPE_GLOBAL) {
+                try {
+                    mTetheringAgent = mDeps.makeNetworkAgent(mContext, Looper.myLooper(), TAG,
+                            mInterfaceType, mLinkProperties);
+                    // Entering CONNECTING state, the ConnectivityService will create the
+                    // native network.
+                    mTetheringAgent.register();
+                } catch (RuntimeException e) {
+                    mLog.e("Error Creating Local Network", e);
+                    // If an exception occurs during the creation or registration of the
+                    // NetworkAgent, it typically indicates a problem with the system services.
+                    mLastError = TETHER_ERROR_SERVICE_UNAVAIL;
+                    return;
+                }
+            }
+
             if (!startIPv4(getScope())) {
                 mLastError = TETHER_ERROR_IFACE_CFG_ERROR;
                 return;
@@ -1122,14 +1189,16 @@ public class IpServer extends StateMachineShim {
                 // Enable IPv6, disable accepting RA, etc. See TetherController::tetherInterface()
                 // for more detail.
                 mNetd.tetherInterfaceAdd(mIfaceName);
-                NetdUtils.networkAddInterface(mNetd, LOCAL_NET_ID, mIfaceName,
+                if (mTetheringAgent == null) {
-                        20 /* maxAttempts */, 50 /* pollingIntervalMs */);
+                    NetdUtils.networkAddInterface(mNetd, LOCAL_NET_ID, mIfaceName,
-                // Activate a route to dest and IPv6 link local.
+                            20 /* maxAttempts */, 50 /* pollingIntervalMs */);
-                NetdUtils.modifyRoute(mNetd, NetdUtils.ModifyOperation.ADD, LOCAL_NET_ID,
+                    // Activate a route to dest and IPv6 link local.
-                        new RouteInfo(asIpPrefix(mIpv4Address), null, mIfaceName, RTN_UNICAST));
+                    NetdUtils.modifyRoute(mNetd, NetdUtils.ModifyOperation.ADD, LOCAL_NET_ID,
-                NetdUtils.modifyRoute(mNetd, NetdUtils.ModifyOperation.ADD, LOCAL_NET_ID,
+                            new RouteInfo(asIpPrefix(mIpv4Address), null, mIfaceName, RTN_UNICAST));
-                        new RouteInfo(new IpPrefix("fe80::/64"), null, mIfaceName,
+                    NetdUtils.modifyRoute(mNetd, NetdUtils.ModifyOperation.ADD, LOCAL_NET_ID,
-                                RTN_UNICAST));
+                            new RouteInfo(new IpPrefix("fe80::/64"), null, mIfaceName,
+                                    RTN_UNICAST));
+                }
             } catch (RemoteException | ServiceSpecificException | IllegalStateException e) {
                 mLog.e("Error Tethering", e);
                 mLastError = TETHER_ERROR_TETHER_IFACE_ERROR;
@@ -1141,9 +1210,17 @@ public class IpServer extends StateMachineShim {
                 // TODO: Make this a fatal error once Bluetooth IPv6 is sorted.
                 return;
             }
+
+            if (mTetheringAgent != null && everRegistered(mTetheringAgent)) {
+                mTetheringAgent.sendLinkProperties(mLinkProperties);
+                // Mark it connected to notify the applications for
+                // the network availability.
+                mTetheringAgent.markConnected();
+            }
         }
 
         @Override
+        @SuppressLint("NewApi")
         public void exit() {
             // Note that at this point, we're leaving the tethered state.  We can fail any
             // of these operations, but it doesn't really change that we have to try them
@@ -1155,7 +1232,9 @@ public class IpServer extends StateMachineShim {
                 try {
                     mNetd.tetherInterfaceRemove(mIfaceName);
                 } finally {
-                    mNetd.networkRemoveInterface(LOCAL_NET_ID, mIfaceName);
+                    if (mTetheringAgent == null) {
+                        mNetd.networkRemoveInterface(LOCAL_NET_ID, mIfaceName);
+                    }
                 }
             } catch (RemoteException | ServiceSpecificException e) {
                 mLastError = TETHER_ERROR_UNTETHER_IFACE_ERROR;
@@ -1165,6 +1244,11 @@ public class IpServer extends StateMachineShim {
             stopIPv4();
             mBpfCoordinator.removeIpServer(IpServer.this);
 
+            if (mTetheringAgent != null && everRegistered(mTetheringAgent)) {
+                mTetheringAgent.unregister();
+                mTetheringAgent = null;
+            }
+
             resetLinkProperties();
 
             mTetheringMetrics.updateErrorCode(mInterfaceType, mLastError);
@@ -1184,6 +1268,12 @@ public class IpServer extends StateMachineShim {
                     break;
                 case CMD_IPV6_TETHER_UPDATE:
                     updateUpstreamIPv6LinkProperties((LinkProperties) message.obj, message.arg1);
+                    // Sends update to the NetworkAgent.
+                    // TODO: Refactor the callers of sendLinkProperties()
+                    //  and move these code into sendLinkProperties().
+                    if (mTetheringAgent != null && everRegistered(mTetheringAgent)) {
+                        mTetheringAgent.sendLinkProperties(mLinkProperties);
+                    }
                     sendLinkProperties();
                     break;
                 case CMD_IP_FORWARDING_ENABLE_ERROR:
@@ -1236,13 +1326,17 @@ public class IpServer extends StateMachineShim {
             // Remove deprecated routes from downstream network.
             final List<RouteInfo> routesToBeRemoved =
                     List.of(getDirectConnectedRoute(deprecatedLinkAddress));
-            removeRoutesFromNetwork(LOCAL_NET_ID, routesToBeRemoved);
+            if (mTetheringAgent == null) {
+                removeRoutesFromNetwork(LOCAL_NET_ID, routesToBeRemoved);
+            }
             for (RouteInfo route : routesToBeRemoved) mLinkProperties.removeRoute(route);
             mLinkProperties.removeLinkAddress(deprecatedLinkAddress);
 
             // Add new routes to downstream network.
             final List<RouteInfo> routesToBeAdded = List.of(getDirectConnectedRoute(mIpv4Address));
-            addRoutesToNetwork(LOCAL_NET_ID, routesToBeAdded);
+            if (mTetheringAgent == null) {
+                addRoutesToNetwork(LOCAL_NET_ID, routesToBeAdded);
+            }
             for (RouteInfo route : routesToBeAdded) mLinkProperties.addRoute(route);
             mLinkProperties.addLinkAddress(mIpv4Address);
 
@@ -1255,6 +1349,10 @@ public class IpServer extends StateMachineShim {
                 mLog.e("Failed to update local DNS caching server");
                 return;
             }
+            // Sends update to the NetworkAgent.
+            if (mTetheringAgent != null && everRegistered(mTetheringAgent)) {
+                mTetheringAgent.sendLinkProperties(mLinkProperties);
+            }
             sendLinkProperties();
 
             // Notify DHCP server that new prefix/route has been applied on IpServer.

Tethering/src/com/android/networkstack/tethering/Tethering.java

@@ -3105,7 +3105,7 @@ public class Tethering {
 
         mLog.i("adding IpServer for: " + iface);
         final TetherState tetherState = new TetherState(
-                new IpServer(iface, mHandler, interfaceType, mLog, mNetd, mBpfCoordinator,
+                new IpServer(iface, mContext, mHandler, interfaceType, mLog, mNetd, mBpfCoordinator,
                         mRoutingCoordinator, new ControlCallback(), mConfig, mTetheringMetrics,
                         mDeps.makeIpServerDependencies()), isNcm);
         mTetherStates.put(iface, tetherState);

Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java

@@ -148,6 +148,12 @@ public class TetheringConfiguration {
      */
     public static final String TETHER_ACTIVE_SESSIONS_METRICS = "tether_active_sessions_metrics";
 
+    /**
+     * A feature flag to control whether the tethering local network agent should be enabled.
+     * Disabled by default.
+     */
+    public static final String TETHERING_LOCAL_NETWORK_AGENT = "tethering_local_network_agent";
+
     public final String[] tetherableUsbRegexs;
     public final String[] tetherableWifiRegexs;
     public final String[] tetherableWigigRegexs;

Tethering/src/com/android/networkstack/tethering/util/TetheringUtils.java

@@ -15,8 +15,20 @@
  */
 package com.android.networkstack.tethering.util;
 
+import static android.net.NetworkCapabilities.TRANSPORT_BLUETOOTH;
+import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
+import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
+import static android.net.NetworkCapabilities.TRANSPORT_USB;
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_GLOBAL;
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_LOCAL;
+import static android.net.TetheringManager.TETHERING_BLUETOOTH;
+import static android.net.TetheringManager.TETHERING_ETHERNET;
+import static android.net.TetheringManager.TETHERING_NCM;
+import static android.net.TetheringManager.TETHERING_USB;
+import static android.net.TetheringManager.TETHERING_VIRTUAL;
+import static android.net.TetheringManager.TETHERING_WIFI;
+import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+import static android.net.TetheringManager.TETHERING_WIGIG;
 
 import android.net.TetherStatsParcel;
 import android.net.TetheringManager.TetheringRequest;
@@ -207,4 +219,30 @@ public class TetheringUtils {
         request.getParcel().connectivityScope = CONNECTIVITY_SCOPE_GLOBAL;
         return request;
     }
+
+    /**
+     * Returns the transport type for the given interface type.
+     *
+     * @param interfaceType The interface type.
+     * @return The transport type.
+     * @throws IllegalArgumentException if the interface type is invalid.
+     */
+    public static int getTransportTypeForTetherableType(int interfaceType) {
+        switch (interfaceType) {
+            case TETHERING_WIFI:
+            case TETHERING_WIGIG:
+            case TETHERING_WIFI_P2P:
+                return TRANSPORT_WIFI;
+            case TETHERING_USB:
+            case TETHERING_NCM:
+                return TRANSPORT_USB;
+            case TETHERING_BLUETOOTH:
+                return TRANSPORT_BLUETOOTH;
+            case TETHERING_ETHERNET:
+            case TETHERING_VIRTUAL: // For virtual machines.
+                return TRANSPORT_ETHERNET;
+            default:
+                throw new IllegalArgumentException("Invalid interface type: " + interfaceType);
+        }
+    }
 }

Tethering/tests/integration/src/android/net/EthernetTetheringTest.java

@@ -18,6 +18,8 @@ package android.net;
 
 import static android.Manifest.permission.DUMP;
 import static android.net.InetAddresses.parseNumericAddress;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_LOCAL_NETWORK;
+import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_LOCAL;
 import static android.net.TetheringManager.CONNECTIVITY_SCOPE_GLOBAL;
 import static android.net.TetheringManager.TETHERING_ETHERNET;
@@ -27,6 +29,7 @@ import static android.net.TetheringTester.buildIcmpEchoPacketV4;
 import static android.net.TetheringTester.buildUdpPacket;
 import static android.net.TetheringTester.isExpectedIcmpPacket;
 import static android.net.TetheringTester.isExpectedUdpDnsPacket;
+import static android.provider.DeviceConfig.NAMESPACE_TETHERING;
 import static android.system.OsConstants.ICMP_ECHO;
 import static android.system.OsConstants.ICMP_ECHOREPLY;
 import static android.system.OsConstants.IPPROTO_UDP;
@@ -78,12 +81,16 @@ import com.android.net.module.util.bpf.TetherStatsKey;
 import com.android.net.module.util.bpf.TetherStatsValue;
 import com.android.net.module.util.structs.Ipv4Header;
 import com.android.net.module.util.structs.UdpHeader;
+import com.android.testutils.AutoReleaseNetworkCallbackRule;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
+import com.android.testutils.DeviceConfigRule;
 import com.android.testutils.DeviceInfoUtils;
 import com.android.testutils.DumpTestUtils;
 import com.android.testutils.NetworkStackModuleTest;
 import com.android.testutils.PollPacketReader;
+import com.android.testutils.RecorderCallback.CallbackEntry;
+import com.android.testutils.TestableNetworkCallback;
 
 import org.junit.After;
 import org.junit.Rule;
@@ -111,6 +118,12 @@ import java.util.concurrent.TimeoutException;
 public class EthernetTetheringTest extends EthernetTetheringTestBase {
     @Rule
     public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
+    // For manipulating feature flag before and after testing.
+    @Rule
+    public final DeviceConfigRule mDeviceConfigRule = new DeviceConfigRule();
+    @Rule
+    public final AutoReleaseNetworkCallbackRule
+            mNetworkCallbackRule = new AutoReleaseNetworkCallbackRule();
 
     private static final String TAG = EthernetTetheringTest.class.getSimpleName();
 
@@ -200,6 +213,9 @@ public class EthernetTetheringTest extends EthernetTetheringTestBase {
             (byte) 0x01, (byte) 0x02, (byte) 0x03, (byte) 0x04  /* Address: 1.2.3.4 */
     };
 
+    // Shamelessly copied from TetheringConfiguration.
+    private static final String TETHERING_LOCAL_NETWORK_AGENT = "tethering_local_network_agent";
+
     @After
     public void tearDown() throws Exception {
         super.tearDown();
@@ -1224,4 +1240,44 @@ public class EthernetTetheringTest extends EthernetTetheringTestBase {
             maybeUnregisterTetheringEventCallback(tetheringEventCallback);
         }
     }
+
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @Test
+    public void testLocalAgent_networkCallbacks() throws Exception {
+        mDeviceConfigRule.setConfig(NAMESPACE_TETHERING, TETHERING_LOCAL_NETWORK_AGENT, "1");
+        assumeFalse(isInterfaceForTetheringAvailable());
+        setIncludeTestInterfaces(true);
+
+        TestNetworkInterface downstreamIface = null;
+        MyTetheringEventCallback tetheringEventCallback = null;
+
+        final TestableNetworkCallback networkCallback = new TestableNetworkCallback();
+        final NetworkRequest networkRequest = new NetworkRequest.Builder()
+                .addCapability(NET_CAPABILITY_LOCAL_NETWORK).build();
+        mNetworkCallbackRule.registerNetworkCallback(networkRequest, networkCallback);
+
+        try {
+            downstreamIface = createTestInterface();
+
+            final String iface = mTetheredInterfaceRequester.getInterface();
+            assertEquals("TetheredInterfaceCallback for unexpected interface",
+                    downstreamIface.getInterfaceName(), iface);
+
+            final TetheringRequest request = new TetheringRequest.Builder(TETHERING_ETHERNET)
+                    .setConnectivityScope(CONNECTIVITY_SCOPE_GLOBAL).build();
+            tetheringEventCallback = enableTethering(iface, request, null /* any upstream */);
+            tetheringEventCallback.awaitInterfaceTethered();
+
+            // Verify NetworkCallback works accordingly.
+            final Network network = networkCallback.expect(CallbackEntry.AVAILABLE).getNetwork();
+            final CallbackEntry.CapabilitiesChanged capEvent =
+                    networkCallback.eventuallyExpect(CallbackEntry.NETWORK_CAPS_UPDATED);
+            assertEquals(network, capEvent.getNetwork());
+            assertTrue(capEvent.getCaps().hasTransport(TRANSPORT_ETHERNET));
+            assertTrue(capEvent.getCaps().hasCapability(NET_CAPABILITY_LOCAL_NETWORK));
+        } finally {
+            stopEthernetTethering(tetheringEventCallback);
+            maybeCloseTestInterface(downstreamIface);
+        }
+    }
 }

Tethering/tests/unit/src/android/net/ip/IpServerTest.java

@@ -28,6 +28,7 @@ import static android.net.TetheringManager.TETHERING_WIFI;
 import static android.net.TetheringManager.TETHERING_WIFI_P2P;
 import static android.net.TetheringManager.TETHER_ERROR_ENABLE_FORWARDING_ERROR;
 import static android.net.TetheringManager.TETHER_ERROR_NO_ERROR;
+import static android.net.TetheringManager.TETHER_ERROR_SERVICE_UNAVAIL;
 import static android.net.TetheringManager.TETHER_ERROR_TETHER_IFACE_ERROR;
 import static android.net.dhcp.IDhcpServer.STATUS_SUCCESS;
 import static android.net.ip.IpServer.STATE_AVAILABLE;
@@ -37,7 +38,9 @@ import static android.net.ip.IpServer.STATE_UNAVAILABLE;
 import static android.net.ip.IpServer.getTetherableIpv6Prefixes;
 
 import static com.android.modules.utils.build.SdkLevel.isAtLeastT;
+import static com.android.modules.utils.build.SdkLevel.isAtLeastV;
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
+import static com.android.networkstack.tethering.TetheringConfiguration.TETHERING_LOCAL_NETWORK_AGENT;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -53,6 +56,7 @@ import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
@@ -64,7 +68,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
 
-import android.app.usage.NetworkStatsManager;
+import android.content.Context;
 import android.net.INetd;
 import android.net.InetAddresses;
 import android.net.InterfaceConfigurationParcel;
@@ -72,6 +76,8 @@ import android.net.IpPrefix;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.MacAddress;
+import android.net.Network;
+import android.net.NetworkAgent;
 import android.net.RouteInfo;
 import android.net.TetheringManager.TetheringRequest;
 import android.net.dhcp.DhcpServerCallbacks;
@@ -83,8 +89,10 @@ import android.net.ip.RouterAdvertisementDaemon.RaParams;
 import android.os.Build;
 import android.os.Handler;
 import android.os.RemoteException;
+import android.os.ServiceSpecificException;
 import android.os.test.TestLooper;
 import android.text.TextUtils;
+import android.util.ArrayMap;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
@@ -100,6 +108,7 @@ import com.android.networkstack.tethering.util.PrefixUtils;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
+import com.android.testutils.com.android.testutils.SetFeatureFlagsRule;
 
 import org.junit.Before;
 import org.junit.Rule;
@@ -122,6 +131,16 @@ public class IpServerTest {
     @Rule
     public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
 
+    final ArrayMap<String, Boolean> mFeatureFlags = new ArrayMap<>();
+    // This will set feature flags from @FeatureFlag annotations
+    // into the map before setUp() runs.
+    @Rule
+    public final SetFeatureFlagsRule mSetFeatureFlagsRule =
+            new SetFeatureFlagsRule((name, enabled) -> {
+                mFeatureFlags.put(name, enabled);
+                return null;
+            }, (name) -> mFeatureFlags.getOrDefault(name, false));
+
     private static final String IFACE_NAME = "testnet1";
     private static final String UPSTREAM_IFACE = "upstream0";
     private static final String UPSTREAM_IFACE2 = "upstream1";
@@ -164,6 +183,7 @@ public class IpServerTest {
             new LinkAddress("2001:db8:0:abcd::168/64"));
     private static final Set<IpPrefix> UPSTREAM_PREFIXES2 = Set.of(
             new IpPrefix("2001:db8:0:1234::/64"), new IpPrefix("2001:db8:0:abcd::/64"));
+    private static final int TEST_NET_ID = 123;
 
     @Mock private INetd mNetd;
     @Mock private IpServer.Callback mCallback;
@@ -173,10 +193,11 @@ public class IpServerTest {
     @Mock private RouterAdvertisementDaemon mRaDaemon;
     @Mock private IpServer.Dependencies mDependencies;
     @Mock private RoutingCoordinatorManager mRoutingCoordinatorManager;
-    @Mock private NetworkStatsManager mStatsManager;
     @Mock private TetheringConfiguration mTetherConfig;
     @Mock private TetheringMetrics mTetheringMetrics;
     @Mock private BpfCoordinator mBpfCoordinator;
+    @Mock private Context mContext;
+    @Mock private NetworkAgent mNetworkAgent;
 
     @Captor private ArgumentCaptor<DhcpServingParamsParcel> mDhcpParamsCaptor;
 
@@ -205,6 +226,18 @@ public class IpServerTest {
         when(mDependencies.getInterfaceParams(UPSTREAM_IFACE)).thenReturn(UPSTREAM_IFACE_PARAMS);
         when(mDependencies.getInterfaceParams(UPSTREAM_IFACE2)).thenReturn(UPSTREAM_IFACE_PARAMS2);
         when(mDependencies.getInterfaceParams(IPSEC_IFACE)).thenReturn(IPSEC_IFACE_PARAMS);
+        doAnswer(
+                invocation -> mFeatureFlags.getOrDefault((String) invocation.getArgument(1), false)
+        ).when(mDependencies).isFeatureEnabled(any(), anyString());
+        if (isAtLeastV()) {
+            when(mDependencies.makeNetworkAgent(any(), any(), anyString(), anyInt(), any()))
+                    .thenReturn(mNetworkAgent);
+            // Mock the returned network and modifying the status.
+            final Network network = mock(Network.class);
+            doReturn(TEST_NET_ID).when(network).getNetId();
+            doReturn(network).when(mNetworkAgent).register();
+            doReturn(network).when(mNetworkAgent).getNetwork();
+        }
 
         mInterfaceConfiguration = new InterfaceConfigurationParcel();
         mInterfaceConfiguration.flags = new String[0];
@@ -294,10 +327,9 @@ public class IpServerTest {
     private IpServer createIpServer(final int interfaceType) {
         mLooper = new TestLooper();
         mHandler = new Handler(mLooper.getLooper());
-        return new IpServer(IFACE_NAME, mHandler, interfaceType, mSharedLog, mNetd, mBpfCoordinator,
+        return new IpServer(IFACE_NAME, mContext, mHandler, interfaceType, mSharedLog, mNetd,
-                mRoutingCoordinatorManager, mCallback, mTetherConfig,
+                mBpfCoordinator, mRoutingCoordinatorManager, mCallback, mTetherConfig,
                 mTetheringMetrics, mDependencies);
-
     }
 
     @Test
@@ -342,6 +374,10 @@ public class IpServerTest {
         verifyNoMoreInteractions(mNetd, mCallback);
     }
 
+    private boolean isTetheringNetworkAgentFeatureEnabled() {
+        return isAtLeastV() && mFeatureFlags.getOrDefault(TETHERING_LOCAL_NETWORK_AGENT, false);
+    }
+
     @Test
     public void canBeTetheredAsBluetooth() throws Exception {
         initStateMachine(TETHERING_BLUETOOTH);
@@ -360,10 +396,16 @@ public class IpServerTest {
                     IFACE_NAME.equals(cfg.ifName) && assertContainsFlag(cfg.flags, IF_STATE_UP)));
         }
         inOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
-        inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
-        // One for ipv4 route, one for ipv6 link local route.
+            inOrder.verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
-        inOrder.verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME),
+            inOrder.verify(mNetd, never())
-                any(), any());
+                    .networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+            // One for ipv4 route, one for ipv6 link local route.
+            inOrder.verify(mNetd, times(2))
+                    .networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME), any(), any());
+        }
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_TETHERED, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
@@ -379,7 +421,11 @@ public class IpServerTest {
         InOrder inOrder = inOrder(mCallback, mNetd, mRoutingCoordinatorManager);
         inOrder.verify(mNetd).tetherApplyDnsInterfaces();
         inOrder.verify(mNetd).tetherInterfaceRemove(IFACE_NAME);
-        inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
+            inOrder.verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        }
         // One is ipv4 address clear (set to 0.0.0.0), another is set interface down which only
         // happen after T. Before T, the interface configuration control in bluetooth side.
         if (isAtLeastT()) {
@@ -411,9 +457,15 @@ public class IpServerTest {
         inOrder.verify(mNetd).interfaceSetCfg(argThat(cfg ->
                 IFACE_NAME.equals(cfg.ifName) && assertContainsFlag(cfg.flags, IF_STATE_UP)));
         inOrder.verify(mNetd).tetherInterfaceAdd(IFACE_NAME);
-        inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
-        inOrder.verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME),
+            inOrder.verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
-                any(), any());
+            inOrder.verify(mNetd, never())
+                    .networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            inOrder.verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+            inOrder.verify(mNetd, times(2))
+                    .networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(IFACE_NAME), any(), any());
+        }
         inOrder.verify(mCallback).updateInterfaceState(
                 mIpServer, STATE_TETHERED, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mCallback).updateLinkProperties(
@@ -592,7 +644,11 @@ public class IpServerTest {
         inOrder.verify(mBpfCoordinator).clearAllIpv6Rules(mIpServer);
         inOrder.verify(mNetd).tetherApplyDnsInterfaces();
         inOrder.verify(mNetd).tetherInterfaceRemove(IFACE_NAME);
-        inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
+            inOrder.verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            inOrder.verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, IFACE_NAME);
+        }
         inOrder.verify(mNetd, times(isAtLeastT() ? 2 : 1)).interfaceSetCfg(
                 argThat(cfg -> IFACE_NAME.equals(cfg.ifName)));
         inOrder.verify(mRoutingCoordinatorManager).releaseDownstream(any());
@@ -1058,6 +1114,162 @@ public class IpServerTest {
         return true;
     }
 
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT)
+    @Test
+    public void testTetheringNetworkAgent_tetheringAgentEnabled() throws Exception {
+        doTestTetheringNetworkAgent(CONNECTIVITY_SCOPE_GLOBAL, true);
+    }
+
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT, enabled = false)
+    @Test
+    public void testTetheringNetworkAgent_tetheringAgentDisabled() throws Exception {
+        doTestTetheringNetworkAgent(CONNECTIVITY_SCOPE_GLOBAL, false);
+    }
+
+    // Verify Tethering Network Agent feature doesn't affect Wi-fi P2P Group Owner although
+    // the code is mostly shared.
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT)
+    @Test
+    public void testTetheringNetworkAgent_p2pGroupOwnerAgentDisabled() throws Exception {
+        doTestTetheringNetworkAgent(CONNECTIVITY_SCOPE_LOCAL, false);
+    }
+
+    private void doTestTetheringNetworkAgent(int scope, boolean expectAgentEnabled)
+            throws Exception {
+        initStateMachine(TETHERING_USB);
+
+        final InOrder inOrder = inOrder(mNetworkAgent, mNetd);
+        dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED,
+                0, createMockTetheringRequest(scope));
+
+        inOrder.verify(mNetworkAgent, expectAgentEnabled ? times(1) : never()).register();
+        inOrder.verify(mNetd, times(1)).tetherInterfaceAdd(anyString());
+        if (expectAgentEnabled) {
+            inOrder.verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
+            inOrder.verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), any(), any());
+            inOrder.verify(mNetworkAgent, times(1)).sendLinkProperties(any());
+            inOrder.verify(mNetworkAgent, times(1)).markConnected();
+        } else {
+            inOrder.verify(mNetd, times(1)).networkAddInterface(anyInt(), anyString());
+            inOrder.verify(mNetd, times(2)).networkAddRoute(anyInt(), anyString(), any(), any());
+            inOrder.verify(mNetworkAgent, never()).sendLinkProperties(any());
+            inOrder.verify(mNetworkAgent, never()).markConnected();
+        }
+
+        dispatchCommand(IpServer.CMD_TETHER_UNREQUESTED);
+        if (expectAgentEnabled) {
+            inOrder.verify(mNetworkAgent, times(1)).unregister();
+            inOrder.verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            inOrder.verify(mNetworkAgent, never()).unregister();
+            inOrder.verify(mNetd, times(1)).networkRemoveInterface(anyInt(), anyString());
+        }
+    }
+
+    // Verify if the registration failed, tethering can be gracefully shutdown.
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT)
+    @Test
+    public void testTetheringNetworkAgent_registerThrows() throws Exception {
+        initStateMachine(TETHERING_USB);
+
+        final InOrder inOrder = inOrder(mNetworkAgent, mNetd, mCallback);
+        doReturn(null).when(mNetworkAgent).getNetwork();
+        doThrow(IllegalStateException.class).when(mNetworkAgent).register();
+        dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED,
+                0, createMockTetheringRequest(CONNECTIVITY_SCOPE_GLOBAL));
+
+        inOrder.verify(mNetworkAgent).register();
+        inOrder.verify(mNetd, never()).networkCreate(any());
+        inOrder.verify(mNetworkAgent, never()).sendLinkProperties(any());
+        inOrder.verify(mNetworkAgent, never()).markConnected();
+        inOrder.verify(mNetworkAgent, never()).unregister();
+        inOrder.verify(mNetd, never()).networkDestroy(anyInt());
+        inOrder.verify(mCallback).updateInterfaceState(
+                mIpServer, STATE_AVAILABLE, TETHER_ERROR_SERVICE_UNAVAIL);
+    }
+
+    // Verify if the network creation failed, tethering can be gracefully shutdown.
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT)
+    @Test
+    public void testTetheringNetworkAgent_netdThrows() throws Exception {
+        initStateMachine(TETHERING_USB);
+
+        final InOrder inOrder = inOrder(mNetworkAgent, mNetd, mCallback);
+        doThrow(ServiceSpecificException.class).when(mNetd).tetherInterfaceAdd(any());
+        dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED,
+                0, createMockTetheringRequest(CONNECTIVITY_SCOPE_GLOBAL));
+
+        inOrder.verify(mNetworkAgent).register();
+        inOrder.verify(mNetd, never()).networkCreate(any());
+        inOrder.verify(mNetworkAgent, never()).sendLinkProperties(any());
+        inOrder.verify(mNetworkAgent, never()).markConnected();
+        inOrder.verify(mNetworkAgent).unregister();
+        inOrder.verify(mNetd, never()).networkDestroy(anyInt());
+        inOrder.verify(mCallback).updateInterfaceState(
+                mIpServer, STATE_AVAILABLE, TETHER_ERROR_TETHER_IFACE_ERROR);
+    }
+
+    // Verify when IPv6 address update, set routes accordingly.
+    @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @SetFeatureFlagsRule.FeatureFlag(name = TETHERING_LOCAL_NETWORK_AGENT)
+    @Test
+    public void testTetheringNetworkAgent_ipv6AddressUpdate() throws Exception {
+        initStateMachine(TETHERING_USB);
+
+        final InOrder inOrder = inOrder(mNetworkAgent, mNetd);
+        dispatchCommand(IpServer.CMD_TETHER_REQUESTED, STATE_TETHERED,
+                0, createMockTetheringRequest(CONNECTIVITY_SCOPE_GLOBAL));
+
+        inOrder.verify(mNetworkAgent).register();
+        inOrder.verify(mNetd, never()).networkCreate(any());
+        inOrder.verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), any(), any());
+
+        // Ipv6 link local route won't show up in the LinkProperties, so just
+        // verify ipv4 route.
+        final ArgumentCaptor<LinkProperties> lpCaptor =
+                ArgumentCaptor.forClass(LinkProperties.class);
+        inOrder.verify(mNetworkAgent).sendLinkProperties(lpCaptor.capture());
+        final RouteInfo expectedIpv4Route = new RouteInfo(PrefixUtils.asIpPrefix(mTestAddress),
+                null, IFACE_NAME, RouteInfo.RTN_UNICAST);
+        assertRoutes(List.of(expectedIpv4Route), lpCaptor.getValue().getRoutes());
+        assertEquals(IFACE_NAME, lpCaptor.getValue().getInterfaceName());
+
+        inOrder.verify(mNetworkAgent).markConnected();
+
+        // Mock ipv4-only upstream show up.
+        dispatchTetherConnectionChanged(UPSTREAM_IFACE);
+        inOrder.verifyNoMoreInteractions();
+
+        // Verify LinkProperties is updated when IPv6 connectivity is available.
+        final LinkProperties lp = new LinkProperties();
+        lp.setInterfaceName(UPSTREAM_IFACE);
+        lp.setLinkAddresses(UPSTREAM_ADDRESSES);
+        dispatchTetherConnectionChanged(UPSTREAM_IFACE, lp, -1);
+        inOrder.verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), any(), any());
+        inOrder.verify(mNetworkAgent).sendLinkProperties(lpCaptor.capture());
+
+        // Expect one Ipv4 route, plus one Ipv6 route.
+        final RouteInfo expectedIpv6Route = new RouteInfo(UPSTREAM_PREFIXES.toArray(
+                new IpPrefix[0])[0], null, IFACE_NAME, RouteInfo.RTN_UNICAST);
+        assertRoutes(List.of(expectedIpv4Route, expectedIpv6Route),
+                lpCaptor.getValue().getRoutes());
+        assertEquals(IFACE_NAME, lpCaptor.getValue().getInterfaceName());
+
+        dispatchCommand(IpServer.CMD_TETHER_UNREQUESTED);
+        inOrder.verify(mNetworkAgent).unregister();
+        inOrder.verify(mNetd, never()).networkDestroy(anyInt());
+    }
+
+    private void assertRoutes(List<RouteInfo> expectedRoutes, List<RouteInfo> actualRoutes) {
+        assertTrue("Expected Routes: " + expectedRoutes + ", but got: " + actualRoutes,
+                expectedRoutes.equals(actualRoutes));
+    }
+
     @Test @IgnoreUpTo(Build.VERSION_CODES.R)
     public void dadProxyUpdates() throws Exception {
         InOrder inOrder = inOrder(mDadProxy);

Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java

@@ -75,6 +75,7 @@ import static android.telephony.SubscriptionManager.INVALID_SUBSCRIPTION_ID;
 
 import static com.android.modules.utils.build.SdkLevel.isAtLeastS;
 import static com.android.modules.utils.build.SdkLevel.isAtLeastT;
+import static com.android.modules.utils.build.SdkLevel.isAtLeastV;
 import static com.android.net.module.util.Inet4AddressUtils.inet4AddressToIntHTH;
 import static com.android.net.module.util.Inet4AddressUtils.intToInet4AddressHTH;
 import static com.android.net.module.util.NetworkStackConstants.RFC7421_PREFIX_LENGTH;
@@ -83,6 +84,7 @@ import static com.android.networkstack.tethering.OffloadHardwareInterface.OFFLOA
 import static com.android.networkstack.tethering.TestConnectivityManager.BROADCAST_FIRST;
 import static com.android.networkstack.tethering.TestConnectivityManager.CALLBACKS_FIRST;
 import static com.android.networkstack.tethering.Tethering.UserRestrictionActionListener;
+import static com.android.networkstack.tethering.TetheringConfiguration.TETHERING_LOCAL_NETWORK_AGENT;
 import static com.android.networkstack.tethering.TetheringConfiguration.TETHER_FORCE_USB_FUNCTIONS;
 import static com.android.networkstack.tethering.TetheringConfiguration.TETHER_USB_NCM_FUNCTION;
 import static com.android.networkstack.tethering.TetheringConfiguration.TETHER_USB_RNDIS_FUNCTION;
@@ -192,6 +194,7 @@ import android.telephony.CarrierConfigManager;
 import android.telephony.PhoneStateListener;
 import android.telephony.TelephonyManager;
 import android.test.mock.MockContentResolver;
+import android.util.ArrayMap;
 import android.util.ArraySet;
 
 import androidx.annotation.NonNull;
@@ -219,6 +222,7 @@ import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.MiscAsserts;
+import com.android.testutils.com.android.testutils.SetFeatureFlagsRule;
 
 import org.junit.After;
 import org.junit.Before;
@@ -250,6 +254,16 @@ import java.util.concurrent.Executor;
 public class TetheringTest {
     @Rule public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
 
+    final ArrayMap<String, Boolean> mFeatureFlags = new ArrayMap<>();
+    // This will set feature flags from @FeatureFlag annotations
+    // into the map before setUp() runs.
+    @Rule
+    public final SetFeatureFlagsRule mSetFeatureFlagsRule =
+            new SetFeatureFlagsRule((name, enabled) -> {
+                mFeatureFlags.put(name, enabled);
+                return null;
+            }, (name) -> mFeatureFlags.getOrDefault(name, false));
+
     private static final int IFINDEX_OFFSET = 100;
 
     private static final String TEST_MOBILE_IFNAME = "test_rmnet_data0";
@@ -461,6 +475,11 @@ public class TetheringTest {
         public void setOnDhcpServerCreatedResult(final int result) {
             mOnDhcpServerCreatedResult = result;
         }
+
+        @Override
+        public boolean isFeatureEnabled(Context context, String name) {
+            return mFeatureFlags.getOrDefault(name, false);
+        }
     }
 
     public class MockTetheringDependencies extends TetheringDependencies {
@@ -954,12 +973,18 @@ public class TetheringTest {
         verifyNoMoreInteractions(mCm);
     }
 
-    private void verifyInterfaceServingModeStarted(String ifname) throws Exception {
+    private void verifyInterfaceServingModeStarted(String ifname, boolean expectAgentEnabled)
+            throws Exception {
         verify(mNetd).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
         verify(mNetd).tetherInterfaceAdd(ifname);
-        verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, ifname);
+        if (expectAgentEnabled) {
-        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(ifname),
+            verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
-                anyString(), anyString());
+            verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, ifname);
+            verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(ifname),
+                    anyString(), anyString());
+        }
     }
 
     private void verifyTetheringBroadcast(String ifname, String whichExtra) {
@@ -1061,10 +1086,18 @@ public class TetheringTest {
         failingLocalOnlyHotspotLegacyApBroadcast(false);
     }
 
-    private void verifyStopHotpot() throws Exception {
+    private boolean isTetheringNetworkAgentFeatureEnabled() {
+        return isAtLeastV() && mFeatureFlags.getOrDefault(TETHERING_LOCAL_NETWORK_AGENT, false);
+    }
+
+    private void verifyStopHotpot(boolean isLocalOnly) throws Exception {
         verify(mNetd).tetherApplyDnsInterfaces();
         verify(mNetd).tetherInterfaceRemove(TEST_WLAN_IFNAME);
-        verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        if (!isLocalOnly && isTetheringNetworkAgentFeatureEnabled()) {
+            verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        }
         // interfaceSetCfg() called once for enabling and twice disabling IPv4.
         verify(mNetd, times(3)).interfaceSetCfg(any(InterfaceConfigurationParcel.class));
         verify(mNetd).tetherStop();
@@ -1083,7 +1116,8 @@ public class TetheringTest {
     }
 
     private void verifyStartHotspot(boolean isLocalOnly) throws Exception {
-        verifyInterfaceServingModeStarted(TEST_WLAN_IFNAME);
+        final boolean expectAgentEnabled = !isLocalOnly && isTetheringNetworkAgentFeatureEnabled();
+        verifyInterfaceServingModeStarted(TEST_WLAN_IFNAME, expectAgentEnabled);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_AVAILABLE_TETHER);
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
@@ -1127,7 +1161,7 @@ public class TetheringTest {
         mTethering.interfaceRemoved(TEST_WLAN_IFNAME);
         mLooper.dispatchAll();
 
-        verifyStopHotpot();
+        verifyStopHotpot(true /* isLocalOnly */);
     }
 
     /**
@@ -2073,7 +2107,7 @@ public class TetheringTest {
         mTethering.interfaceRemoved(TEST_WLAN_IFNAME);
         mLooper.dispatchAll();
 
-        verifyStopHotpot();
+        verifyStopHotpot(false /* isLocalOnly */);
     }
 
     @Test
@@ -2218,9 +2252,14 @@ public class TetheringTest {
         // code is refactored the two calls during shutdown will revert to one.
         verify(mNetd, times(3)).interfaceSetCfg(argThat(p -> TEST_WLAN_IFNAME.equals(p.ifName)));
         verify(mNetd, times(1)).tetherInterfaceAdd(TEST_WLAN_IFNAME);
-        verify(mNetd, times(1)).networkAddInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
-        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_WLAN_IFNAME),
+            verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
-                anyString(), anyString());
+            verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            verify(mNetd, times(1)).networkAddInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+            verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_WLAN_IFNAME),
+                    anyString(), anyString());
+        }
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
         verify(mWifiManager).updateInterfaceIpState(
@@ -2239,7 +2278,11 @@ public class TetheringTest {
         // so it can take down AP mode.
         verify(mNetd, times(1)).tetherApplyDnsInterfaces();
         verify(mNetd, times(1)).tetherInterfaceRemove(TEST_WLAN_IFNAME);
-        verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
+            verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            verify(mNetd, times(1)).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_WLAN_IFNAME);
+        }
         verify(mWifiManager).updateInterfaceIpState(
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_CONFIGURATION_ERROR);
 
@@ -3100,7 +3143,7 @@ public class TetheringTest {
         }
         sendWifiP2pConnectionChanged(true, true, TEST_P2P_IFNAME);
 
-        verifyInterfaceServingModeStarted(TEST_P2P_IFNAME);
+        verifyInterfaceServingModeStarted(TEST_P2P_IFNAME, false);
         verifyTetheringBroadcast(TEST_P2P_IFNAME, EXTRA_AVAILABLE_TETHER);
         verify(mNetd, times(1)).ipfwdEnableForwarding(TETHERING_NAME);
         verify(mNetd, times(1)).tetherStartWithConfiguration(any());
@@ -4119,13 +4162,22 @@ public class TetheringTest {
                     && assertContainsFlag(cfg.flags, INetd.IF_STATE_UP)));
         }
         verify(mNetd).tetherInterfaceAdd(TEST_BT_IFNAME);
-        verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, TEST_BT_IFNAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
-        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_BT_IFNAME),
+            verify(mNetd, never()).networkAddInterface(anyInt(), anyString());
-                anyString(), anyString());
+            verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            verify(mNetd).networkAddInterface(INetd.LOCAL_NET_ID, TEST_BT_IFNAME);
+            verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_BT_IFNAME),
+                    anyString(), anyString());
+        }
         verify(mNetd).ipfwdEnableForwarding(TETHERING_NAME);
         verify(mNetd).tetherStartWithConfiguration(any());
-        verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_BT_IFNAME),
+        if (isTetheringNetworkAgentFeatureEnabled()) {
-                anyString(), anyString());
+            verify(mNetd, never()).networkAddRoute(anyInt(), anyString(), anyString(), anyString());
+        } else {
+            verify(mNetd, times(2)).networkAddRoute(eq(INetd.LOCAL_NET_ID), eq(TEST_BT_IFNAME),
+                    anyString(), anyString());
+        }
         verifyNoMoreInteractions(mNetd);
         reset(mNetd);
     }
@@ -4140,7 +4192,11 @@ public class TetheringTest {
     private void verifyNetdCommandForBtTearDown() throws Exception {
         verify(mNetd).tetherApplyDnsInterfaces();
         verify(mNetd).tetherInterfaceRemove(TEST_BT_IFNAME);
-        verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_BT_IFNAME);
+        if (isTetheringNetworkAgentFeatureEnabled()) {
+            verify(mNetd, never()).networkRemoveInterface(anyInt(), anyString());
+        } else {
+            verify(mNetd).networkRemoveInterface(INetd.LOCAL_NET_ID, TEST_BT_IFNAME);
+        }
         // One is ipv4 address clear (set to 0.0.0.0), another is set interface down which only
         // happen after T. Before T, the interface configuration control in bluetooth side.
         verify(mNetd, times(isAtLeastT() ? 2 : 1)).interfaceSetCfg(
@@ -4405,7 +4461,7 @@ public class TetheringTest {
         initTetheringOnTestThread();
         // Enable wifi P2P.
         sendWifiP2pConnectionChanged(true, true, TEST_P2P_IFNAME);
-        verifyInterfaceServingModeStarted(TEST_P2P_IFNAME);
+        verifyInterfaceServingModeStarted(TEST_P2P_IFNAME, false);
         verifyTetheringBroadcast(TEST_P2P_IFNAME, EXTRA_AVAILABLE_TETHER);
         verifyTetheringBroadcast(TEST_P2P_IFNAME, EXTRA_ACTIVE_LOCAL_ONLY);
         verify(mUpstreamNetworkMonitor).startObserveUpstreamNetworks();

framework/src/android/net/connectivity/ConnectivityInternalApiUtil.java

@@ -16,11 +16,25 @@
 
 package android.net.connectivity;
 
+import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_METERED;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED;
+
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.net.ConnectivityManager;
+import android.net.LinkProperties;
+import android.net.LocalNetworkConfig;
+import android.net.NetworkAgent;
+import android.net.NetworkAgentConfig;
+import android.net.NetworkCapabilities;
+import android.net.NetworkScore;
 import android.os.Build;
 import android.os.IBinder;
+import android.os.Looper;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
 
 /**
@@ -57,4 +71,36 @@ public class ConnectivityInternalApiUtil {
         final ConnectivityManager cm = ctx.getSystemService(ConnectivityManager.class);
         return cm.getRoutingCoordinatorService();
     }
+
+    /**
+     * Create a NetworkAgent instance to be used by Tethering.
+     * @param ctx the context
+     * @return an instance of the {@code NetworkAgent}
+     */
+    // TODO: Expose LocalNetworkConfig related APIs and delete this method. This method is
+    //  only here because on R Tethering is installed and not Connectivity, requiring all
+    //  shared classes to be public API. LocalNetworkConfig is not public yet, but it will
+    //  only be used by Tethering on V+ so it's fine.
+    @SuppressLint("WrongConstant")
+    @NonNull
+    public static NetworkAgent buildTetheringNetworkAgent(@NonNull Context ctx,
+            @NonNull Looper looper, @NonNull String logTag, int transportType,
+            @NonNull LinkProperties lp) {
+        final NetworkCapabilities.Builder builder = new NetworkCapabilities.Builder()
+                .addCapability(NET_CAPABILITY_NOT_METERED)
+                .addCapability(NET_CAPABILITY_NOT_ROAMING)
+                .addCapability(NET_CAPABILITY_NOT_CONGESTED)
+                .addCapability(NET_CAPABILITY_NOT_SUSPENDED)
+                .addTransportType(transportType);
+        // TODO: Change to use the constant definition. Flags.netCapabilityLocalNetwork() was not
+        //  fully rolled out but the service will still process this capability, set it anyway.
+        builder.addCapability(36 /* NET_CAPABILITY_LOCAL_NETWORK */);
+        final NetworkCapabilities caps = builder.build();
+        final NetworkAgentConfig nac = new NetworkAgentConfig.Builder().build();
+        return new NetworkAgent(ctx, looper, logTag, caps, lp,
+                new LocalNetworkConfig.Builder().build(), new NetworkScore.Builder()
+                .setKeepConnectedReason(NetworkScore.KEEP_CONNECTED_LOCAL_NETWORK)
+                .build(), nac, null /* provider */) {
+        };
+    }
 }