diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index bd4a27c..227a4cb 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -228,7 +228,7 @@
          * @param capability The capability to add to unwanted capability list.
          * @return The builder to facilitate chaining.
          *
-         * @removed
+         * @hide
          */
         public Builder addUnwantedCapability(@NetworkCapabilities.NetCapability int capability) {
             mNetworkCapabilities.addUnwantedCapability(capability);
@@ -436,7 +436,7 @@
     /**
      * @see Builder#addUnwantedCapability(int)
      *
-     * @removed
+     * @hide
      */
     public boolean hasUnwantedCapability(@NetCapability int capability) {
         return networkCapabilities.hasUnwantedCapability(capability);
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 5afb0a6..9994462 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -238,8 +238,9 @@
 
     private KeyStore mKeyStore;
 
+    @VisibleForTesting
     @GuardedBy("mVpns")
-    private final SparseArray<Vpn> mVpns = new SparseArray<Vpn>();
+    protected final SparseArray<Vpn> mVpns = new SparseArray<Vpn>();
 
     // TODO: investigate if mLockdownEnabled can be removed and replaced everywhere by
     // a direct call to LockdownVpnTracker.isEnabled().
@@ -929,6 +930,15 @@
                 deps);
     }
 
+    private static NetworkCapabilities createDefaultNetworkCapabilitiesForUid(int uid) {
+        final NetworkCapabilities netCap = new NetworkCapabilities();
+        netCap.addCapability(NET_CAPABILITY_INTERNET);
+        netCap.addCapability(NET_CAPABILITY_NOT_RESTRICTED);
+        netCap.removeCapability(NET_CAPABILITY_NOT_VPN);
+        netCap.setSingleUid(uid);
+        return netCap;
+    }
+
     private NetworkRequest createDefaultInternetRequestForTransport(
             int transportType, NetworkRequest.Type type) {
         NetworkCapabilities netCap = new NetworkCapabilities();
@@ -1181,12 +1191,20 @@
         int vpnNetId = NETID_UNSET;
         synchronized (mVpns) {
             final Vpn vpn = mVpns.get(user);
+            // TODO : now that capabilities contain the UID, the appliesToUid test should
+            // be removed as the satisfying test below should be enough.
             if (vpn != null && vpn.appliesToUid(uid)) vpnNetId = vpn.getNetId();
         }
         NetworkAgentInfo nai;
         if (vpnNetId != NETID_UNSET) {
             nai = getNetworkAgentInfoForNetId(vpnNetId);
-            if (nai != null) return nai.network;
+            if (nai != null) {
+                final NetworkCapabilities requiredCaps =
+                    createDefaultNetworkCapabilitiesForUid(uid);
+                if (requiredCaps.satisfiedByNetworkCapabilities(nai.networkCapabilities)) {
+                    return nai.network;
+                }
+            }
         }
         nai = getDefaultNetwork();
         if (nai != null
@@ -1401,8 +1419,10 @@
     private NetworkCapabilities networkCapabilitiesRestrictedForCallerPermissions(
             NetworkCapabilities nc, int callerPid, int callerUid) {
         final NetworkCapabilities newNc = new NetworkCapabilities(nc);
-        if (!checkSettingsPermission(callerPid, callerUid)) newNc.setUids(null);
-        if (!checkSettingsPermission(callerPid, callerUid)) newNc.setSSID(null);
+        if (!checkSettingsPermission(callerPid, callerUid)) {
+            newNc.setUids(null);
+            newNc.setSSID(null);
+        }
         return newNc;
     }
 
@@ -4304,8 +4324,7 @@
         // the default network request. This allows callers to keep track of
         // the system default network.
         if (type == NetworkRequest.Type.TRACK_DEFAULT) {
-            networkCapabilities = new NetworkCapabilities(mDefaultRequest.networkCapabilities);
-            networkCapabilities.removeCapability(NET_CAPABILITY_NOT_VPN);
+            networkCapabilities = createDefaultNetworkCapabilitiesForUid(Binder.getCallingUid());
             enforceAccessPermission();
         } else {
             networkCapabilities = new NetworkCapabilities(networkCapabilities);
@@ -4562,7 +4581,7 @@
 
     // Note: if mDefaultRequest is changed, NetworkMonitor needs to be updated.
     private final NetworkRequest mDefaultRequest;
-
+ 
     // Request used to optionally keep mobile data active even when higher
     // priority networks like Wi-Fi are active.
     private final NetworkRequest mDefaultMobileDataRequest;
diff --git a/services/core/java/com/android/server/connectivity/DnsManager.java b/services/core/java/com/android/server/connectivity/DnsManager.java
index 7aaac06..d51a196 100644
--- a/services/core/java/com/android/server/connectivity/DnsManager.java
+++ b/services/core/java/com/android/server/connectivity/DnsManager.java
@@ -49,6 +49,7 @@
 import java.net.UnknownHostException;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -211,6 +212,8 @@
         }
 
         // Validation statuses of <hostname, ipAddress> pairs for a single netId
+        // Caution : not thread-safe. As mentioned in the top file comment, all
+        // methods of this class must only be called on ConnectivityService's thread.
         private Map<Pair<String, InetAddress>, ValidationStatus> mValidationMap;
 
         private PrivateDnsValidationStatuses() {
@@ -262,6 +265,16 @@
                 mValidationMap.put(p, ValidationStatus.FAILED);
             }
         }
+
+        private LinkProperties fillInValidatedPrivateDns(LinkProperties lp) {
+            lp.setValidatedPrivateDnsServers(Collections.EMPTY_LIST);
+            mValidationMap.forEach((key, value) -> {
+                    if (value == ValidationStatus.SUCCEEDED) {
+                        lp.addValidatedPrivateDnsServer(key.second);
+                    }
+                });
+            return lp;
+        }
     }
 
     private final Context mContext;
@@ -315,23 +328,19 @@
                 PRIVATE_DNS_OFF);
 
         final boolean useTls = privateDnsCfg.useTls;
+        final PrivateDnsValidationStatuses statuses =
+                useTls ? mPrivateDnsValidationMap.get(netId) : null;
+        final boolean validated = (null != statuses) && statuses.hasValidatedServer();
         final boolean strictMode = privateDnsCfg.inStrictMode();
-        final String tlsHostname = strictMode ? privateDnsCfg.hostname : "";
+        final String tlsHostname = strictMode ? privateDnsCfg.hostname : null;
+        final boolean usingPrivateDns = strictMode || validated;
 
-        if (strictMode) {
-            lp.setUsePrivateDns(true);
-            lp.setPrivateDnsServerName(tlsHostname);
-        } else if (useTls) {
-            // We are in opportunistic mode. Private DNS should be used if there
-            // is a known DNS-over-TLS validated server.
-            boolean validated = mPrivateDnsValidationMap.containsKey(netId) &&
-                    mPrivateDnsValidationMap.get(netId).hasValidatedServer();
-            lp.setUsePrivateDns(validated);
-            lp.setPrivateDnsServerName(null);
+        lp.setUsePrivateDns(usingPrivateDns);
+        lp.setPrivateDnsServerName(tlsHostname);
+        if (usingPrivateDns && null != statuses) {
+            statuses.fillInValidatedPrivateDns(lp);
         } else {
-            // Private DNS is disabled.
-            lp.setUsePrivateDns(false);
-            lp.setPrivateDnsServerName(null);
+            lp.setValidatedPrivateDnsServers(Collections.EMPTY_LIST);
         }
     }
 
diff --git a/services/net/java/android/net/apf/ApfCapabilities.java b/services/net/java/android/net/apf/ApfCapabilities.java
index 703b415..dec8ca2 100644
--- a/services/net/java/android/net/apf/ApfCapabilities.java
+++ b/services/net/java/android/net/apf/ApfCapabilities.java
@@ -49,4 +49,14 @@
         return String.format("%s{version: %d, maxSize: %d, format: %d}", getClass().getSimpleName(),
                 apfVersionSupported, maximumApfProgramSize, apfPacketFormat);
     }
+
+    /**
+     * Returns true if the APF interpreter advertises support for the data buffer access opcodes
+     * LDDW and STDW.
+     *
+     * Full LDDW and STDW support is present from APFv4 on.
+     */
+    public boolean hasDataAccess() {
+        return apfVersionSupported >= 4;
+    }
 }
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 482d6e1..5b73bba 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -84,6 +84,7 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.content.pm.UserInfo;
 import android.content.res.Resources;
 import android.net.CaptivePortal;
 import android.net.ConnectivityManager;
@@ -201,6 +202,7 @@
     @Mock DefaultNetworkMetrics mDefaultNetworkMetrics;
     @Mock INetworkManagementService mNetworkManagementService;
     @Mock INetworkStatsService mStatsService;
+    @Mock Vpn mMockVpn;
 
     private ArgumentCaptor<String[]> mStringArrayCaptor = ArgumentCaptor.forClass(String[].class);
 
@@ -505,6 +507,7 @@
                 mWrappedNetworkMonitor.gen204ProbeResult = 204;
                 NetworkRequest request = new NetworkRequest.Builder()
                         .addTransportType(mNetworkCapabilities.getTransportTypes()[0])
+                        .clearCapabilities()
                         .build();
                 callback = new NetworkCallback() {
                     public void onCapabilitiesChanged(Network network,
@@ -888,6 +891,15 @@
             return mLastCreatedNetworkMonitor;
         }
 
+        public void mockVpn(int uid) {
+            synchronized (mVpns) {
+                // This has no effect unless the VPN is actually connected, because things like
+                // getActiveNetworkForUidInternal call getNetworkAgentInfoForNetId on the VPN
+                // netId, and check if that network is actually connected.
+                mVpns.put(UserHandle.getUserId(Process.myUid()), mMockVpn);
+            }
+        }
+
         public void waitForIdle(int timeoutMs) {
             waitForIdleHandler(mHandlerThread, timeoutMs);
         }
@@ -914,6 +926,7 @@
 
         MockitoAnnotations.initMocks(this);
         when(mMetricsService.defaultNetworkMetrics()).thenReturn(mDefaultNetworkMetrics);
+        when(mMockVpn.appliesToUid(Process.myUid())).thenReturn(true);
 
         // InstrumentationTestRunner prepares a looper, but AndroidJUnitRunner does not.
         // http://b/25897652 .
@@ -935,6 +948,7 @@
         // getSystemService() correctly.
         mCm = new WrappedConnectivityManager(InstrumentationRegistry.getContext(), mService);
         mService.systemReady();
+        mService.mockVpn(Process.myUid());
         mCm.bindProcessToNetwork(null);
 
         // Ensure that the default setting for Captive Portals is used for most tests
@@ -1347,6 +1361,7 @@
         private final static int TIMEOUT_MS = 100;
 
         private final LinkedBlockingQueue<CallbackInfo> mCallbacks = new LinkedBlockingQueue<>();
+        private Network mLastAvailableNetwork;
 
         protected void setLastCallback(CallbackState state, Network network, Object o) {
             mCallbacks.offer(new CallbackInfo(state, network, o));
@@ -1354,6 +1369,7 @@
 
         @Override
         public void onAvailable(Network network) {
+            mLastAvailableNetwork = network;
             setLastCallback(CallbackState.AVAILABLE, network, null);
         }
 
@@ -1389,9 +1405,14 @@
 
         @Override
         public void onLost(Network network) {
+            mLastAvailableNetwork = null;
             setLastCallback(CallbackState.LOST, network, null);
         }
 
+        public Network getLastAvailableNetwork() {
+            return mLastAvailableNetwork;
+        }
+
         CallbackInfo nextCallback(int timeoutMs) {
             CallbackInfo cb = null;
             try {
@@ -1658,6 +1679,7 @@
         callback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         defaultCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         assertEquals(mCellNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         mWiFiNetworkAgent.connect(true);
         // We get AVAILABLE on wifi when wifi connects and satisfies our unmetered request.
@@ -1668,6 +1690,7 @@
         callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, mWiFiNetworkAgent);
         defaultCallback.expectAvailableDoubleValidatedCallbacks(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         mEthernetNetworkAgent.connect(true);
         callback.expectAvailableCallbacksUnvalidated(mEthernetNetworkAgent);
@@ -1676,11 +1699,13 @@
         callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, mEthernetNetworkAgent);
         defaultCallback.expectAvailableDoubleValidatedCallbacks(mEthernetNetworkAgent);
         assertEquals(mEthernetNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         mEthernetNetworkAgent.disconnect();
         callback.expectCallback(CallbackState.LOST, mEthernetNetworkAgent);
         defaultCallback.expectCallback(CallbackState.LOST, mEthernetNetworkAgent);
         defaultCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         for (int i = 0; i < 4; i++) {
             MockNetworkAgent oldNetwork, newNetwork;
@@ -1709,6 +1734,7 @@
         defaultCallback.expectCapabilitiesWithout(NET_CAPABILITY_NOT_METERED, mWiFiNetworkAgent);
         defaultCallback.assertNoCallback();
         callback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Wifi no longer satisfies our listen, which is for an unmetered network.
         // But because its score is 55, it's still up (and the default network).
@@ -1718,8 +1744,11 @@
         mWiFiNetworkAgent.disconnect();
         defaultCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksValidated(mCellNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
         mCellNetworkAgent.disconnect();
         defaultCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
+        waitForIdle();
+        assertEquals(null, mCm.getActiveNetwork());
 
         mCm.unregisterNetworkCallback(callback);
         waitForIdle();
@@ -1736,6 +1765,7 @@
         callback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         assertEquals(mCellNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring up wifi with a score of 20.
         // Cell stays up because it would satisfy the default request if it validated.
@@ -1744,12 +1774,14 @@
         callback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         mWiFiNetworkAgent.disconnect();
         callback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         assertEquals(mCellNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring up wifi with a score of 70.
         // Cell is lingered because it would not satisfy any request, even if it validated.
@@ -1760,6 +1792,7 @@
         callback.expectCallback(CallbackState.LOSING, mCellNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Tear down wifi.
         mWiFiNetworkAgent.disconnect();
@@ -1767,6 +1800,7 @@
         defaultCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksUnvalidated(mCellNetworkAgent);
         assertEquals(mCellNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring up wifi, then validate it. Previous versions would immediately tear down cell, but
         // it's arguably correct to linger it, since it was the default network before it validated.
@@ -1778,6 +1812,7 @@
         callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, mWiFiNetworkAgent);
         defaultCallback.expectAvailableThenValidatedCallbacks(mWiFiNetworkAgent);
         assertEquals(mWiFiNetworkAgent.getNetwork(), mCm.getActiveNetwork());
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         mWiFiNetworkAgent.disconnect();
         callback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
@@ -1786,12 +1821,15 @@
         mCellNetworkAgent.disconnect();
         callback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
         defaultCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
+        waitForIdle();
+        assertEquals(null, mCm.getActiveNetwork());
 
         // If a network is lingering, and we add and remove a request from it, resume lingering.
         mCellNetworkAgent = new MockNetworkAgent(TRANSPORT_CELLULAR);
         mCellNetworkAgent.connect(true);
         callback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         defaultCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
         mWiFiNetworkAgent = new MockNetworkAgent(TRANSPORT_WIFI);
         mWiFiNetworkAgent.connect(true);
         defaultCallback.expectAvailableDoubleValidatedCallbacks(mWiFiNetworkAgent);
@@ -1799,6 +1837,7 @@
         // TODO: Investigate sending validated before losing.
         callback.expectCallback(CallbackState.LOSING, mCellNetworkAgent);
         callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, mWiFiNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         NetworkRequest cellRequest = new NetworkRequest.Builder()
                 .addTransportType(TRANSPORT_CELLULAR).build();
@@ -1815,6 +1854,7 @@
         callback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         defaultCallback.expectAvailableCallbacksValidated(mCellNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Cell is now the default network. Pin it with a cell-specific request.
         noopCallback = new NetworkCallback();  // Can't reuse NetworkCallbacks. http://b/20701525
@@ -1825,6 +1865,7 @@
         mWiFiNetworkAgent.connect(true);
         callback.expectAvailableThenValidatedCallbacks(mWiFiNetworkAgent);
         defaultCallback.expectAvailableDoubleValidatedCallbacks(mWiFiNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
         // The default request is lingering on cell, but nothing happens to cell, and we send no
         // callbacks for it, because it's kept up by cellRequest.
         callback.assertNoCallback();
@@ -1848,6 +1889,7 @@
         callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, mEthernetNetworkAgent);
         trackDefaultCallback.expectAvailableDoubleValidatedCallbacks(mEthernetNetworkAgent);
         defaultCallback.expectAvailableDoubleValidatedCallbacks(mEthernetNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Let linger run its course.
         callback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent, lingerTimeoutMs);
@@ -2496,23 +2538,27 @@
         mCellNetworkAgent.connect(true);
         cellNetworkCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         defaultNetworkCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
+        assertEquals(defaultNetworkCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring up wifi and expect CALLBACK_AVAILABLE.
         mWiFiNetworkAgent = new MockNetworkAgent(TRANSPORT_WIFI);
         mWiFiNetworkAgent.connect(true);
         cellNetworkCallback.assertNoCallback();
         defaultNetworkCallback.expectAvailableDoubleValidatedCallbacks(mWiFiNetworkAgent);
+        assertEquals(defaultNetworkCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring down cell. Expect no default network callback, since it wasn't the default.
         mCellNetworkAgent.disconnect();
         cellNetworkCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
         defaultNetworkCallback.assertNoCallback();
+        assertEquals(defaultNetworkCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring up cell. Expect no default network callback, since it won't be the default.
         mCellNetworkAgent = new MockNetworkAgent(TRANSPORT_CELLULAR);
         mCellNetworkAgent.connect(true);
         cellNetworkCallback.expectAvailableThenValidatedCallbacks(mCellNetworkAgent);
         defaultNetworkCallback.assertNoCallback();
+        assertEquals(defaultNetworkCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         // Bring down wifi. Expect the default network callback to notified of LOST wifi
         // followed by AVAILABLE cell.
@@ -2523,6 +2569,23 @@
         mCellNetworkAgent.disconnect();
         cellNetworkCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
         defaultNetworkCallback.expectCallback(CallbackState.LOST, mCellNetworkAgent);
+        waitForIdle();
+        assertEquals(null, mCm.getActiveNetwork());
+
+        final int uid = Process.myUid();
+        final MockNetworkAgent vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
+        final ArraySet<UidRange> ranges = new ArraySet<>();
+        ranges.add(new UidRange(uid, uid));
+        when(mMockVpn.getNetId()).thenReturn(vpnNetworkAgent.getNetwork().netId);
+        vpnNetworkAgent.setUids(ranges);
+        vpnNetworkAgent.connect(true);
+        defaultNetworkCallback.expectAvailableThenValidatedCallbacks(vpnNetworkAgent);
+        assertEquals(defaultNetworkCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
+
+        vpnNetworkAgent.disconnect();
+        defaultNetworkCallback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
+        waitForIdle();
+        assertEquals(null, mCm.getActiveNetwork());
     }
 
     @Test
@@ -4015,6 +4078,7 @@
         final TestNetworkCallback genericNotVpnNetworkCallback = new TestNetworkCallback();
         final TestNetworkCallback wifiNetworkCallback = new TestNetworkCallback();
         final TestNetworkCallback vpnNetworkCallback = new TestNetworkCallback();
+        final TestNetworkCallback defaultCallback = new TestNetworkCallback();
         final NetworkRequest genericNotVpnRequest = new NetworkRequest.Builder().build();
         final NetworkRequest genericRequest = new NetworkRequest.Builder()
                 .removeCapability(NET_CAPABILITY_NOT_VPN).build();
@@ -4027,6 +4091,8 @@
         mCm.registerNetworkCallback(genericNotVpnRequest, genericNotVpnNetworkCallback);
         mCm.registerNetworkCallback(wifiRequest, wifiNetworkCallback);
         mCm.registerNetworkCallback(vpnNetworkRequest, vpnNetworkCallback);
+        mCm.registerDefaultNetworkCallback(defaultCallback);
+        defaultCallback.assertNoCallback();
 
         mWiFiNetworkAgent = new MockNetworkAgent(TRANSPORT_WIFI);
         mWiFiNetworkAgent.connect(false);
@@ -4034,15 +4100,14 @@
         genericNetworkCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         genericNotVpnNetworkCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         wifiNetworkCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
+        defaultCallback.expectAvailableCallbacksUnvalidated(mWiFiNetworkAgent);
         vpnNetworkCallback.assertNoCallback();
-
-        // TODO : check callbacks agree with the return value of mCm.getActiveNetwork().
-        // Right now this is not possible because establish() is not adequately instrumented
-        // in this test.
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         final MockNetworkAgent vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
         final ArraySet<UidRange> ranges = new ArraySet<>();
         ranges.add(new UidRange(uid, uid));
+        when(mMockVpn.getNetId()).thenReturn(vpnNetworkAgent.getNetwork().netId);
         vpnNetworkAgent.setUids(ranges);
         vpnNetworkAgent.connect(false);
 
@@ -4050,10 +4115,14 @@
         genericNotVpnNetworkCallback.assertNoCallback();
         wifiNetworkCallback.assertNoCallback();
         vpnNetworkCallback.expectAvailableCallbacksUnvalidated(vpnNetworkAgent);
+        defaultCallback.expectAvailableCallbacksUnvalidated(vpnNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         genericNetworkCallback.expectCallback(CallbackState.NETWORK_CAPABILITIES, vpnNetworkAgent);
         genericNotVpnNetworkCallback.assertNoCallback();
         vpnNetworkCallback.expectCapabilitiesLike(nc -> null == nc.getUids(), vpnNetworkAgent);
+        defaultCallback.expectCallback(CallbackState.NETWORK_CAPABILITIES, vpnNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
 
         ranges.clear();
         vpnNetworkAgent.setUids(ranges);
@@ -4063,6 +4132,14 @@
         wifiNetworkCallback.assertNoCallback();
         vpnNetworkCallback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
 
+        // TODO : The default network callback should actually get a LOST call here (also see the
+        // comment below for AVAILABLE). This is because ConnectivityService does not look at UID
+        // ranges at all when determining whether a network should be rematched. In practice, VPNs
+        // can't currently update their UIDs without disconnecting, so this does not matter too
+        // much, but that is the reason the test here has to check for an update to the
+        // capabilities instead of the expected LOST then AVAILABLE.
+        defaultCallback.expectCallback(CallbackState.NETWORK_CAPABILITIES, vpnNetworkAgent);
+
         ranges.add(new UidRange(uid, uid));
         vpnNetworkAgent.setUids(ranges);
 
@@ -4070,6 +4147,9 @@
         genericNotVpnNetworkCallback.assertNoCallback();
         wifiNetworkCallback.assertNoCallback();
         vpnNetworkCallback.expectAvailableCallbacksValidated(vpnNetworkAgent);
+        // TODO : Here like above, AVAILABLE would be correct, but because this can't actually
+        // happen outside of the test, ConnectivityService does not rematch callbacks.
+        defaultCallback.expectCallback(CallbackState.NETWORK_CAPABILITIES, vpnNetworkAgent);
 
         mWiFiNetworkAgent.disconnect();
 
@@ -4077,6 +4157,7 @@
         genericNotVpnNetworkCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         wifiNetworkCallback.expectCallback(CallbackState.LOST, mWiFiNetworkAgent);
         vpnNetworkCallback.assertNoCallback();
+        defaultCallback.assertNoCallback();
 
         vpnNetworkAgent.disconnect();
 
@@ -4084,9 +4165,61 @@
         genericNotVpnNetworkCallback.assertNoCallback();
         wifiNetworkCallback.assertNoCallback();
         vpnNetworkCallback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
+        defaultCallback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
+        assertEquals(null, mCm.getActiveNetwork());
 
         mCm.unregisterNetworkCallback(genericNetworkCallback);
         mCm.unregisterNetworkCallback(wifiNetworkCallback);
         mCm.unregisterNetworkCallback(vpnNetworkCallback);
+        mCm.unregisterNetworkCallback(defaultCallback);
+    }
+
+    @Test
+    public void testVpnWithAndWithoutInternet() {
+        final int uid = Process.myUid();
+
+        final TestNetworkCallback defaultCallback = new TestNetworkCallback();
+        mCm.registerDefaultNetworkCallback(defaultCallback);
+        defaultCallback.assertNoCallback();
+
+        mWiFiNetworkAgent = new MockNetworkAgent(TRANSPORT_WIFI);
+        mWiFiNetworkAgent.connect(true);
+
+        defaultCallback.expectAvailableThenValidatedCallbacks(mWiFiNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
+
+        MockNetworkAgent vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
+        final ArraySet<UidRange> ranges = new ArraySet<>();
+        ranges.add(new UidRange(uid, uid));
+        when(mMockVpn.getNetId()).thenReturn(vpnNetworkAgent.getNetwork().netId);
+        vpnNetworkAgent.setUids(ranges);
+        vpnNetworkAgent.connect(true /* validated */, false /* hasInternet */);
+
+        defaultCallback.assertNoCallback();
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
+
+        vpnNetworkAgent.disconnect();
+        defaultCallback.assertNoCallback();
+
+        vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
+        when(mMockVpn.getNetId()).thenReturn(vpnNetworkAgent.getNetwork().netId);
+        vpnNetworkAgent.setUids(ranges);
+        vpnNetworkAgent.connect(true /* validated */, true /* hasInternet */);
+        defaultCallback.expectAvailableThenValidatedCallbacks(vpnNetworkAgent);
+        assertEquals(defaultCallback.getLastAvailableNetwork(), mCm.getActiveNetwork());
+
+        vpnNetworkAgent.disconnect();
+        defaultCallback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
+        defaultCallback.expectAvailableCallbacksValidated(mWiFiNetworkAgent);
+
+        vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
+        when(mMockVpn.getNetId()).thenReturn(vpnNetworkAgent.getNetwork().netId);
+        ranges.clear();
+        vpnNetworkAgent.setUids(ranges);
+
+        vpnNetworkAgent.connect(false /* validated */, true /* hasInternet */);
+        defaultCallback.assertNoCallback();
+
+        mCm.unregisterNetworkCallback(defaultCallback);
     }
 }
diff --git a/tests/net/java/com/android/server/connectivity/DnsManagerTest.java b/tests/net/java/com/android/server/connectivity/DnsManagerTest.java
index bcd8bf3..1ec4eec 100644
--- a/tests/net/java/com/android/server/connectivity/DnsManagerTest.java
+++ b/tests/net/java/com/android/server/connectivity/DnsManagerTest.java
@@ -28,8 +28,11 @@
 
 import android.content.ContentResolver;
 import android.content.Context;
+import android.net.IpPrefix;
+import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.Network;
+import android.net.RouteInfo;
 import android.os.INetworkManagementService;
 import android.provider.Settings;
 import android.support.test.filters.SmallTest;
@@ -40,6 +43,7 @@
 import com.android.server.connectivity.MockableSystemProperties;
 
 import java.net.InetAddress;
+import java.util.Arrays;
 
 import org.junit.runner.RunWith;
 import org.junit.Before;
@@ -56,6 +60,7 @@
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class DnsManagerTest {
+    static final String TEST_IFACENAME = "test_wlan0";
     static final int TEST_NETID = 100;
     static final int TEST_NETID_ALTERNATE = 101;
     static final int TEST_NETID_UNTRACKED = 102;
@@ -92,6 +97,7 @@
         mDnsManager.updatePrivateDns(new Network(TEST_NETID_ALTERNATE),
                 mDnsManager.getPrivateDnsConfig());
         LinkProperties lp = new LinkProperties();
+        lp.setInterfaceName(TEST_IFACENAME);
         lp.addDnsServer(InetAddress.getByName("3.3.3.3"));
         lp.addDnsServer(InetAddress.getByName("4.4.4.4"));
 
@@ -109,21 +115,51 @@
         mDnsManager.updatePrivateDnsStatus(TEST_NETID_ALTERNATE, fixedLp);
         assertTrue(fixedLp.isPrivateDnsActive());
         assertNull(fixedLp.getPrivateDnsServerName());
+        assertEquals(Arrays.asList(InetAddress.getByName("4.4.4.4")),
+                fixedLp.getValidatedPrivateDnsServers());
 
-        // Switch to strict mode
+        // Set up addresses for strict mode and switch to it.
+        lp.addLinkAddress(new LinkAddress("192.0.2.4/24"));
+        lp.addRoute(new RouteInfo((IpPrefix) null, InetAddress.getByName("192.0.2.4"),
+                TEST_IFACENAME));
+        lp.addLinkAddress(new LinkAddress("2001:db8:1::1/64"));
+        lp.addRoute(new RouteInfo((IpPrefix) null, InetAddress.getByName("2001:db8:1::1"),
+                TEST_IFACENAME));
+
         Settings.Global.putString(mContentResolver,
-                Settings.Global.PRIVATE_DNS_MODE,
-                PRIVATE_DNS_MODE_PROVIDER_HOSTNAME);
+                Settings.Global.PRIVATE_DNS_MODE, PRIVATE_DNS_MODE_PROVIDER_HOSTNAME);
         Settings.Global.putString(mContentResolver,
                 Settings.Global.PRIVATE_DNS_SPECIFIER, "strictmode.com");
         mDnsManager.updatePrivateDns(new Network(TEST_NETID),
-                mDnsManager.getPrivateDnsConfig());
+                new DnsManager.PrivateDnsConfig("strictmode.com", new InetAddress[] {
+                    InetAddress.parseNumericAddress("6.6.6.6"),
+                    InetAddress.parseNumericAddress("2001:db8:66:66::1")
+                    }));
         mDnsManager.setDnsConfigurationForNetwork(TEST_NETID, lp, IS_DEFAULT);
         fixedLp = new LinkProperties(lp);
         mDnsManager.updatePrivateDnsStatus(TEST_NETID, fixedLp);
         assertTrue(fixedLp.isPrivateDnsActive());
         assertEquals("strictmode.com", fixedLp.getPrivateDnsServerName());
+        // No validation events yet.
+        assertEquals(Arrays.asList(new InetAddress[0]), fixedLp.getValidatedPrivateDnsServers());
+        // Validate one.
+        mDnsManager.updatePrivateDnsValidation(
+                new DnsManager.PrivateDnsValidationUpdate(TEST_NETID,
+                InetAddress.parseNumericAddress("6.6.6.6"), "strictmode.com", true));
         fixedLp = new LinkProperties(lp);
+        mDnsManager.updatePrivateDnsStatus(TEST_NETID, fixedLp);
+        assertEquals(Arrays.asList(InetAddress.parseNumericAddress("6.6.6.6")),
+                fixedLp.getValidatedPrivateDnsServers());
+        // Validate the 2nd one.
+        mDnsManager.updatePrivateDnsValidation(
+                new DnsManager.PrivateDnsValidationUpdate(TEST_NETID,
+                InetAddress.parseNumericAddress("2001:db8:66:66::1"), "strictmode.com", true));
+        fixedLp = new LinkProperties(lp);
+        mDnsManager.updatePrivateDnsStatus(TEST_NETID, fixedLp);
+        assertEquals(Arrays.asList(
+                        InetAddress.parseNumericAddress("2001:db8:66:66::1"),
+                        InetAddress.parseNumericAddress("6.6.6.6")),
+                fixedLp.getValidatedPrivateDnsServers());
     }
 
     @Test