diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 68ac46c..92b30a4 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -678,11 +678,20 @@
     @Deprecated
     public static final int TYPE_VPN = 17;
 
-    /** {@hide} */
-    public static final int MAX_RADIO_TYPE   = TYPE_VPN;
+    /**
+     * A network that is exclusively meant to be used for testing
+     *
+     * @deprecated Use {@link NetworkCapabilities} instead.
+     * @hide
+     */
+    @Deprecated
+    public static final int TYPE_TEST = 18; // TODO: Remove this once NetworkTypes are unused.
 
     /** {@hide} */
-    public static final int MAX_NETWORK_TYPE = TYPE_VPN;
+    public static final int MAX_RADIO_TYPE = TYPE_TEST;
+
+    /** {@hide} */
+    public static final int MAX_NETWORK_TYPE = TYPE_TEST;
 
     private static final int MIN_NETWORK_TYPE = TYPE_MOBILE;
 
@@ -3911,15 +3920,16 @@
      *
      * <p>This endpoint is exclusively for use by the NetworkStack and is protected by the
      * corresponding permission.
+     * @param network Network on which the captive portal was detected.
      * @param appExtras Extras to include in the app start intent.
      * @hide
      */
     @SystemApi
     @TestApi
     @RequiresPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK)
-    public void startCaptivePortalApp(Bundle appExtras) {
+    public void startCaptivePortalApp(Network network, Bundle appExtras) {
         try {
-            mService.startCaptivePortalAppInternal(appExtras);
+            mService.startCaptivePortalAppInternal(network, appExtras);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index 92a5839..83bb3a0 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -168,7 +168,7 @@
     void setAcceptUnvalidated(in Network network, boolean accept, boolean always);
     void setAvoidUnvalidated(in Network network);
     void startCaptivePortalApp(in Network network);
-    void startCaptivePortalAppInternal(in Bundle appExtras);
+    void startCaptivePortalAppInternal(in Network network, in Bundle appExtras);
 
     boolean getAvoidBadWifi();
     int getMultipathPreference(in Network Network);
diff --git a/core/java/android/net/NetworkCapabilities.java b/core/java/android/net/NetworkCapabilities.java
index 7e9bda1..1d2d81d 100644
--- a/core/java/android/net/NetworkCapabilities.java
+++ b/core/java/android/net/NetworkCapabilities.java
@@ -597,6 +597,7 @@
             TRANSPORT_VPN,
             TRANSPORT_WIFI_AWARE,
             TRANSPORT_LOWPAN,
+            TRANSPORT_TEST,
     })
     public @interface Transport { }
 
@@ -635,10 +636,18 @@
      */
     public static final int TRANSPORT_LOWPAN = 6;
 
+    /**
+     * Indicates this network uses a Test-only virtual interface as a transport.
+     *
+     * @hide
+     */
+    @TestApi
+    public static final int TRANSPORT_TEST = 7;
+
     /** @hide */
     public static final int MIN_TRANSPORT = TRANSPORT_CELLULAR;
     /** @hide */
-    public static final int MAX_TRANSPORT = TRANSPORT_LOWPAN;
+    public static final int MAX_TRANSPORT = TRANSPORT_TEST;
 
     /** @hide */
     public static boolean isValidTransport(@Transport int transportType) {
@@ -652,7 +661,8 @@
         "ETHERNET",
         "VPN",
         "WIFI_AWARE",
-        "LOWPAN"
+        "LOWPAN",
+        "TEST"
     };
 
     /**
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 95f2a1f..b5fcde4 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -38,7 +38,6 @@
 import static android.net.NetworkCapabilities.TRANSPORT_VPN;
 import static android.net.NetworkPolicyManager.RULE_NONE;
 import static android.net.NetworkPolicyManager.uidRulesToString;
-import static android.net.NetworkStack.NETWORKSTACK_PACKAGE_NAME;
 import static android.net.shared.NetworkMonitorUtils.isValidationRequired;
 import static android.net.shared.NetworkParcelableUtil.toStableParcelable;
 import static android.os.Process.INVALID_UID;
@@ -58,8 +57,10 @@
 import android.content.IntentFilter;
 import android.content.res.Configuration;
 import android.database.ContentObserver;
+import android.net.CaptivePortal;
 import android.net.ConnectionInfo;
 import android.net.ConnectivityManager;
+import android.net.ICaptivePortal;
 import android.net.IConnectivityManager;
 import android.net.IIpConnectivityMetrics;
 import android.net.INetd;
@@ -86,6 +87,7 @@
 import android.net.NetworkRequest;
 import android.net.NetworkSpecifier;
 import android.net.NetworkStack;
+import android.net.NetworkStackClient;
 import android.net.NetworkState;
 import android.net.NetworkUtils;
 import android.net.NetworkWatchlistManager;
@@ -2675,9 +2677,9 @@
         }
 
         @Override
-        public void showProvisioningNotification(String action) {
+        public void showProvisioningNotification(String action, String packageName) {
             final Intent intent = new Intent(action);
-            intent.setPackage(NETWORKSTACK_PACKAGE_NAME);
+            intent.setPackage(packageName);
 
             final PendingIntent pendingIntent;
             // Only the system server can register notifications with package "android"
@@ -2699,11 +2701,6 @@
                     EVENT_PROVISIONING_NOTIFICATION, PROVISIONING_NOTIFICATION_HIDE,
                     mNai.network.netId));
         }
-
-        @Override
-        public void logCaptivePortalLoginEvent(int eventId, String packageName) {
-            new MetricsLogger().action(eventId, packageName);
-        }
     }
 
     private boolean networkRequiresValidation(NetworkAgentInfo nai) {
@@ -2842,6 +2839,8 @@
         if (DBG) {
             log(nai.name() + " got DISCONNECTED, was satisfying " + nai.numNetworkRequests());
         }
+        // Clear all notifications of this network.
+        mNotifier.clearNotification(nai.network.netId);
         // A network agent has disconnected.
         // TODO - if we move the logic to the network agent (have them disconnect
         // because they lost all their requests or because their score isn't good)
@@ -3247,22 +3246,63 @@
     /**
      * NetworkStack endpoint to start the captive portal app. The NetworkStack needs to use this
      * endpoint as it does not have INTERACT_ACROSS_USERS_FULL itself.
+     * @param network Network on which the captive portal was detected.
      * @param appExtras Bundle to use as intent extras for the captive portal application.
      *                  Must be treated as opaque to avoid preventing the captive portal app to
      *                  update its arguments.
      */
     @Override
-    public void startCaptivePortalAppInternal(Bundle appExtras) {
+    public void startCaptivePortalAppInternal(Network network, Bundle appExtras) {
         mContext.checkCallingOrSelfPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
 
         final Intent appIntent = new Intent(ConnectivityManager.ACTION_CAPTIVE_PORTAL_SIGN_IN);
         appIntent.putExtras(appExtras);
+        appIntent.putExtra(ConnectivityManager.EXTRA_CAPTIVE_PORTAL,
+                new CaptivePortal(new CaptivePortalImpl(network).asBinder()));
         appIntent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK);
 
         Binder.withCleanCallingIdentity(() ->
                 mContext.startActivityAsUser(appIntent, UserHandle.CURRENT));
     }
 
+    private class CaptivePortalImpl extends ICaptivePortal.Stub {
+        private final Network mNetwork;
+
+        private CaptivePortalImpl(Network network) {
+            mNetwork = network;
+        }
+
+        @Override
+        public void appResponse(final int response) throws RemoteException {
+            if (response == CaptivePortal.APP_RETURN_WANTED_AS_IS) {
+                enforceSettingsPermission();
+            }
+
+            // getNetworkAgentInfoForNetwork is thread-safe
+            final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(mNetwork);
+            if (nai == null) return;
+
+            // nai.networkMonitor() is thread-safe
+            final INetworkMonitor nm = nai.networkMonitor();
+            if (nm == null) return;
+
+            final long token = Binder.clearCallingIdentity();
+            try {
+                nm.notifyCaptivePortalAppFinished(response);
+            } finally {
+                // Not using Binder.withCleanCallingIdentity() to keep the checked RemoteException
+                Binder.restoreCallingIdentity(token);
+            }
+        }
+
+        @Override
+        public void logEvent(int eventId, String packageName) {
+            enforceSettingsPermission();
+
+            new MetricsLogger().action(eventId, packageName);
+        }
+    }
+
     public boolean avoidBadWifi() {
         return mMultinetworkPolicyTracker.getAvoidBadWifi();
     }
@@ -5095,7 +5135,7 @@
         if (DBG) log("registerNetworkAgent " + nai);
         final long token = Binder.clearCallingIdentity();
         try {
-            mContext.getSystemService(NetworkStack.class).makeNetworkMonitor(
+            getNetworkStack().makeNetworkMonitor(
                     toStableParcelable(nai.network), name, new NetworkMonitorCallbacks(nai));
         } finally {
             Binder.restoreCallingIdentity(token);
@@ -5107,6 +5147,11 @@
         return nai.network.netId;
     }
 
+    @VisibleForTesting
+    protected NetworkStackClient getNetworkStack() {
+        return NetworkStackClient.getInstance();
+    }
+
     private void handleRegisterNetworkAgent(NetworkAgentInfo nai, INetworkMonitor networkMonitor) {
         nai.onNetworkMonitorCreated(networkMonitor);
         if (VDBG) log("Got NetworkAgent Messenger");
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index d1d6bc2..d1a0692 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -124,7 +124,7 @@
 import android.net.NetworkParcelable;
 import android.net.NetworkRequest;
 import android.net.NetworkSpecifier;
-import android.net.NetworkStack;
+import android.net.NetworkStackClient;
 import android.net.NetworkUtils;
 import android.net.ProxyInfo;
 import android.net.RouteInfo;
@@ -246,7 +246,7 @@
     @Mock INetworkStatsService mStatsService;
     @Mock INetworkPolicyManager mNpm;
     @Mock INetd mMockNetd;
-    @Mock NetworkStack mNetworkStack;
+    @Mock NetworkStackClient mNetworkStack;
 
     private ArgumentCaptor<String[]> mStringArrayCaptor = ArgumentCaptor.forClass(String[].class);
 
@@ -555,7 +555,7 @@
 
                 if (mNmValidationRedirectUrl != null) {
                     mNmCallbacks.showProvisioningNotification(
-                            "test_provisioning_notif_action");
+                            "test_provisioning_notif_action", "com.android.test.package");
                     mNmProvNotificationRequested = true;
                 }
             } catch (RemoteException e) {
@@ -1066,6 +1066,11 @@
         }
 
         @Override
+        protected NetworkStackClient getNetworkStack() {
+            return mNetworkStack;
+        }
+
+        @Override
         public WakeupMessage makeWakeupMessage(
                 Context context, Handler handler, String cmdName, int cmd, Object obj) {
             return new FakeWakeupMessage(context, handler, cmdName, cmd, 0, 0, obj);
@@ -3796,11 +3801,14 @@
     }
 
     @Test
-    public void testNattSocketKeepalives() throws Exception {
+    public void testNattSocketKeepalives_SingleThreadExecutor() throws Exception {
         final ExecutorService executorSingleThread = Executors.newSingleThreadExecutor();
         doTestNattSocketKeepalivesWithExecutor(executorSingleThread);
         executorSingleThread.shutdown();
+    }
 
+    @Test
+    public void testNattSocketKeepalives_InlineExecutor() throws Exception {
         final Executor executorInline = (Runnable r) -> r.run();
         doTestNattSocketKeepalivesWithExecutor(executorInline);
     }
@@ -3942,6 +3950,7 @@
         testSocket2.close();
 
         mWiFiNetworkAgent.disconnect();
+        waitFor(mWiFiNetworkAgent.getDisconnectedCV());
     }
 
     @Test
diff --git a/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java b/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
index 9578ded..aa6cbda 100644
--- a/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/LingerMonitorTest.java
@@ -37,7 +37,6 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
 import android.net.NetworkMisc;
-import android.net.NetworkStack;
 import android.os.INetworkManagementService;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
@@ -74,16 +73,12 @@
     @Mock NetworkMisc mMisc;
     @Mock NetworkNotificationManager mNotifier;
     @Mock Resources mResources;
-    @Mock NetworkStack mNetworkStack;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
         when(mCtx.getResources()).thenReturn(mResources);
         when(mCtx.getPackageName()).thenReturn("com.android.server.connectivity");
-        when(mCtx.getSystemServiceName(NetworkStack.class))
-                .thenReturn(Context.NETWORK_STACK_SERVICE);
-        when(mCtx.getSystemService(Context.NETWORK_STACK_SERVICE)).thenReturn(mNetworkStack);
 
         mMonitor = new TestableLingerMonitor(mCtx, mNotifier, HIGH_DAILY_LIMIT, HIGH_RATE_LIMIT);
     }