Prefer default Internet network for upstream tethering.

Rather than use the crufty config.xml list of upstream transport types,
use ConnectivityService's notion of the default network for the upstream.
In cases where a DUN network is required and the default network is
currently a mobile network, look for a DUN network (code in Tethering
is currently responsible for requesting one).

Test: as follows
    - built, flashed, booted
    - runtest frameworks-net
    - tethered via mobile, joined captive portal network, maintained
      laptop access via mobile until captive passed (then used wifi)
    - disabled client mode wifi, disabled mobile data, plugged in
      ethernet adapter, observed connectivity via ethernet
Bug: 32163131
Bug: 62648872
Bug: 63282480
Bug: 109786760
Bug: 110118584
Bug: 110260419
Merged-In: I9cddf1fb7aa3b8d56bf048c563556244e74808c2
Merged-In: Icac3e5e20e99093ddb85aae1ca07ed7b5cf309fd
Change-Id: I925b75994e31df8046f3ef9916a2457b4210485e
(cherry picked from commit 4080a1bd15572caf149762e45c958627feceb74d)

2 files changed, 150 insertions, 32 deletions

diff --git a/tests/net/java/com/android/server/connectivity/TetheringTest.java b/tests/net/java/com/android/server/connectivity/TetheringTest.java
index 9994cdd5c595..44d8f313f18e 100644
--- a/tests/net/java/com/android/server/connectivity/TetheringTest.java
+++ b/tests/net/java/com/android/server/connectivity/TetheringTest.java
@@ -71,6 +71,7 @@ import android.net.MacAddress;
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
+import android.net.NetworkRequest;
 import android.net.NetworkState;
 import android.net.NetworkUtils;
 import android.net.RouteInfo;
@@ -128,6 +129,10 @@ public class TetheringTest {
     private static final String TEST_USB_IFNAME = "test_rndis0";
     private static final String TEST_WLAN_IFNAME = "test_wlan0";
 
+    // Actual contents of the request don't matter for this test. The lack of
+    // any specific TRANSPORT_* is sufficient to identify this request.
+    private static final NetworkRequest mDefaultRequest = new NetworkRequest.Builder().build();
+
     @Mock private ApplicationInfo mApplicationInfo;
     @Mock private Context mContext;
     @Mock private INetworkManagementService mNMService;
@@ -238,6 +243,11 @@ public class TetheringTest {
             isTetheringSupportedCalls++;
             return true;
         }
+
+        @Override
+        public NetworkRequest getDefaultNetworkRequest() {
+            return mDefaultRequest;
+        }
     }
 
     private static NetworkState buildMobileUpstreamState(boolean withIPv4, boolean withIPv6,
@@ -305,6 +315,8 @@ public class TetheringTest {
                 .thenReturn(new String[0]);
         when(mResources.getIntArray(com.android.internal.R.array.config_tether_upstream_types))
                 .thenReturn(new int[0]);
+        when(mResources.getBoolean(com.android.internal.R.bool.config_tether_upstream_automatic))
+                .thenReturn(false);
         when(mNMService.listInterfaces())
                 .thenReturn(new String[] {
                         TEST_MOBILE_IFNAME, TEST_WLAN_IFNAME, TEST_USB_IFNAME});
@@ -458,6 +470,7 @@ public class TetheringTest {
     }
 
     private void prepareUsbTethering(NetworkState upstreamState) {
+        when(mUpstreamNetworkMonitor.getCurrentPreferredUpstream()).thenReturn(upstreamState);
         when(mUpstreamNetworkMonitor.selectPreferredUpstreamType(any()))
                 .thenReturn(upstreamState);
 
@@ -519,7 +532,7 @@ public class TetheringTest {
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_LOCAL_ONLY);
         verifyNoMoreInteractions(mWifiManager);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_ACTIVE_LOCAL_ONLY);
-        verify(mUpstreamNetworkMonitor, times(1)).start();
+        verify(mUpstreamNetworkMonitor, times(1)).start(any(NetworkRequest.class));
         // TODO: Figure out why this isn't exactly once, for sendTetherStateChangedBroadcast().
         assertTrue(1 <= mTetheringDependencies.isTetheringSupportedCalls);
 
@@ -656,6 +669,24 @@ public class TetheringTest {
     }
 
     @Test
+    public void configTetherUpstreamAutomaticIgnoresConfigTetherUpstreamTypes() throws Exception {
+        when(mResources.getBoolean(com.android.internal.R.bool.config_tether_upstream_automatic))
+                .thenReturn(true);
+        sendConfigurationChanged();
+
+        // Setup IPv6
+        final NetworkState upstreamState = buildMobileIPv6UpstreamState();
+        runUsbTethering(upstreamState);
+
+        // UpstreamNetworkMonitor should choose upstream automatically
+        // (in this specific case: choose the default network).
+        verify(mUpstreamNetworkMonitor, times(1)).getCurrentPreferredUpstream();
+        verify(mUpstreamNetworkMonitor, never()).selectPreferredUpstreamType(any());
+
+        verify(mUpstreamNetworkMonitor, times(1)).setCurrentUpstream(upstreamState.network);
+    }
+
+    @Test
     public void workingLocalOnlyHotspotEnrichedApBroadcastWithIfaceChanged() throws Exception {
         workingLocalOnlyHotspotEnrichedApBroadcast(true);
     }
@@ -718,7 +749,7 @@ public class TetheringTest {
                 TEST_WLAN_IFNAME, WifiManager.IFACE_IP_MODE_TETHERED);
         verifyNoMoreInteractions(mWifiManager);
         verifyTetheringBroadcast(TEST_WLAN_IFNAME, EXTRA_ACTIVE_TETHER);
-        verify(mUpstreamNetworkMonitor, times(1)).start();
+        verify(mUpstreamNetworkMonitor, times(1)).start(any(NetworkRequest.class));
         // In tethering mode, in the default configuration, an explicit request
         // for a mobile network is also made.
         verify(mUpstreamNetworkMonitor, times(1)).registerMobileNetworkRequest();
diff --git a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
index 9661dc24ca2e..3e21a2cfb7f9 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/UpstreamNetworkMonitorTest.java
@@ -31,6 +31,7 @@ import static org.junit.Assert.fail;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyInt;
 import static org.mockito.Mockito.anyString;
+import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
@@ -73,6 +74,7 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 
@@ -84,6 +86,10 @@ public class UpstreamNetworkMonitorTest {
     private static final boolean INCLUDES = true;
     private static final boolean EXCLUDES = false;
 
+    // Actual contents of the request don't matter for this test. The lack of
+    // any specific TRANSPORT_* is sufficient to identify this request.
+    private static final NetworkRequest mDefaultRequest = new NetworkRequest.Builder().build();
+
     @Mock private Context mContext;
     @Mock private IConnectivityManager mCS;
     @Mock private SharedLog mLog;
@@ -113,6 +119,13 @@ public class UpstreamNetworkMonitorTest {
     }
 
     @Test
+    public void testStopWithoutStartIsNonFatal() {
+        mUNM.stop();
+        mUNM.stop();
+        mUNM.stop();
+    }
+
+    @Test
     public void testDoesNothingBeforeStarted() {
         assertTrue(mCM.hasNoCallbacks());
         assertFalse(mUNM.mobileNetworkRequested());
@@ -127,7 +140,7 @@ public class UpstreamNetworkMonitorTest {
     public void testDefaultNetworkIsTracked() throws Exception {
         assertEquals(0, mCM.trackingDefault.size());
 
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
         assertEquals(1, mCM.trackingDefault.size());
 
         mUNM.stop();
@@ -138,7 +151,7 @@ public class UpstreamNetworkMonitorTest {
     public void testListensForAllNetworks() throws Exception {
         assertTrue(mCM.listening.isEmpty());
 
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
         assertFalse(mCM.listening.isEmpty());
         assertTrue(mCM.isListeningForAll());
 
@@ -148,9 +161,11 @@ public class UpstreamNetworkMonitorTest {
 
     @Test
     public void testCallbacksRegistered() {
-        mUNM.start();
-        verify(mCM, times(1)).registerNetworkCallback(any(), any(), any());
-        verify(mCM, times(1)).registerDefaultNetworkCallback(any(), any());
+        mUNM.start(mDefaultRequest);
+        verify(mCM, times(1)).registerNetworkCallback(
+                any(NetworkRequest.class), any(NetworkCallback.class), any(Handler.class));
+        verify(mCM, times(1)).requestNetwork(
+                eq(mDefaultRequest), any(NetworkCallback.class), any(Handler.class));
 
         mUNM.stop();
         verify(mCM, times(2)).unregisterNetworkCallback(any(NetworkCallback.class));
@@ -161,7 +176,7 @@ public class UpstreamNetworkMonitorTest {
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
@@ -184,17 +199,17 @@ public class UpstreamNetworkMonitorTest {
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
-        mUNM.start();
-        verify(mCM, Mockito.times(1)).registerNetworkCallback(
+        mUNM.start(mDefaultRequest);
+        verify(mCM, times(1)).registerNetworkCallback(
                 any(NetworkRequest.class), any(NetworkCallback.class), any(Handler.class));
-        verify(mCM, Mockito.times(1)).registerDefaultNetworkCallback(
-                any(NetworkCallback.class), any(Handler.class));
+        verify(mCM, times(1)).requestNetwork(
+                eq(mDefaultRequest), any(NetworkCallback.class), any(Handler.class));
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
         mUNM.updateMobileRequiresDun(true);
         mUNM.registerMobileNetworkRequest();
-        verify(mCM, Mockito.times(1)).requestNetwork(
+        verify(mCM, times(1)).requestNetwork(
                 any(NetworkRequest.class), any(NetworkCallback.class), anyInt(), anyInt(),
                 any(Handler.class));
 
@@ -222,7 +237,7 @@ public class UpstreamNetworkMonitorTest {
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
         assertFalse(mUNM.mobileNetworkRequested());
         assertEquals(0, mCM.requested.size());
 
@@ -242,7 +257,7 @@ public class UpstreamNetworkMonitorTest {
 
     @Test
     public void testUpdateMobileRequiresDun() throws Exception {
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
 
         // Test going from no-DUN to DUN correctly re-registers callbacks.
         mUNM.updateMobileRequiresDun(false);
@@ -270,7 +285,7 @@ public class UpstreamNetworkMonitorTest {
         final Collection<Integer> preferredTypes = new ArrayList<>();
         preferredTypes.add(TYPE_WIFI);
 
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
         // There are no networks, so there is nothing to select.
         assertSatisfiesLegacyType(TYPE_NONE, mUNM.selectPreferredUpstreamType(preferredTypes));
 
@@ -334,8 +349,47 @@ public class UpstreamNetworkMonitorTest {
     }
 
     @Test
+    public void testGetCurrentPreferredUpstream() throws Exception {
+        mUNM.start(mDefaultRequest);
+        mUNM.updateMobileRequiresDun(false);
+
+        // [0] Mobile connects, DUN not required -> mobile selected.
+        final TestNetworkAgent cellAgent = new TestNetworkAgent(mCM, TRANSPORT_CELLULAR);
+        cellAgent.fakeConnect();
+        mCM.makeDefaultNetwork(cellAgent);
+        assertEquals(cellAgent.networkId, mUNM.getCurrentPreferredUpstream().network);
+
+        // [1] WiFi connects but not validated/promoted to default -> mobile selected.
+        final TestNetworkAgent wifiAgent = new TestNetworkAgent(mCM, TRANSPORT_WIFI);
+        wifiAgent.fakeConnect();
+        assertEquals(cellAgent.networkId, mUNM.getCurrentPreferredUpstream().network);
+
+        // [2] WiFi validates and is promoted to the default network -> WiFi selected.
+        mCM.makeDefaultNetwork(wifiAgent);
+        assertEquals(wifiAgent.networkId, mUNM.getCurrentPreferredUpstream().network);
+
+        // [3] DUN required, no other changes -> WiFi still selected
+        mUNM.updateMobileRequiresDun(true);
+        assertEquals(wifiAgent.networkId, mUNM.getCurrentPreferredUpstream().network);
+
+        // [4] WiFi no longer validated, mobile becomes default, DUN required -> null selected.
+        mCM.makeDefaultNetwork(cellAgent);
+        assertEquals(null, mUNM.getCurrentPreferredUpstream());
+        // TODO: make sure that a DUN request has been filed. This is currently
+        // triggered by code over in Tethering, but once that has been moved
+        // into UNM we should test for this here.
+
+        // [5] DUN network arrives -> DUN selected
+        final TestNetworkAgent dunAgent = new TestNetworkAgent(mCM, TRANSPORT_CELLULAR);
+        dunAgent.networkCapabilities.addCapability(NET_CAPABILITY_DUN);
+        dunAgent.networkCapabilities.removeCapability(NET_CAPABILITY_INTERNET);
+        dunAgent.fakeConnect();
+        assertEquals(dunAgent.networkId, mUNM.getCurrentPreferredUpstream().network);
+    }
+
+    @Test
     public void testLocalPrefixes() throws Exception {
-        mUNM.start();
+        mUNM.start(mDefaultRequest);
 
         // [0] Test minimum set of local prefixes.
         Set<IpPrefix> local = mUNM.getLocalPrefixes();
@@ -345,7 +399,7 @@ public class UpstreamNetworkMonitorTest {
 
         // [1] Pretend Wi-Fi connects.
         final TestNetworkAgent wifiAgent = new TestNetworkAgent(mCM, TRANSPORT_WIFI);
-        final LinkProperties wifiLp = new LinkProperties();
+        final LinkProperties wifiLp = wifiAgent.linkProperties;
         wifiLp.setInterfaceName("wlan0");
         final String[] WIFI_ADDRS = {
                 "fe80::827a:bfff:fe6f:374d", "100.112.103.18",
@@ -358,7 +412,7 @@ public class UpstreamNetworkMonitorTest {
             wifiLp.addLinkAddress(new LinkAddress(addrStr + cidr));
         }
         wifiAgent.fakeConnect();
-        wifiAgent.sendLinkProperties(wifiLp);
+        wifiAgent.sendLinkProperties();
 
         local = mUNM.getLocalPrefixes();
         assertPrefixSet(local, INCLUDES, alreadySeen);
@@ -372,7 +426,7 @@ public class UpstreamNetworkMonitorTest {
 
         // [2] Pretend mobile connects.
         final TestNetworkAgent cellAgent = new TestNetworkAgent(mCM, TRANSPORT_CELLULAR);
-        final LinkProperties cellLp = new LinkProperties();
+        final LinkProperties cellLp = cellAgent.linkProperties;
         cellLp.setInterfaceName("rmnet_data0");
         final String[] CELL_ADDRS = {
                 "10.102.211.48", "2001:db8:0:1:b50e:70d9:10c9:433d",
@@ -382,7 +436,7 @@ public class UpstreamNetworkMonitorTest {
             cellLp.addLinkAddress(new LinkAddress(addrStr + cidr));
         }
         cellAgent.fakeConnect();
-        cellAgent.sendLinkProperties(cellLp);
+        cellAgent.sendLinkProperties();
 
         local = mUNM.getLocalPrefixes();
         assertPrefixSet(local, INCLUDES, alreadySeen);
@@ -394,17 +448,18 @@ public class UpstreamNetworkMonitorTest {
         // [3] Pretend DUN connects.
         final TestNetworkAgent dunAgent = new TestNetworkAgent(mCM, TRANSPORT_CELLULAR);
         dunAgent.networkCapabilities.addCapability(NET_CAPABILITY_DUN);
-        final LinkProperties dunLp = new LinkProperties();
+        dunAgent.networkCapabilities.removeCapability(NET_CAPABILITY_INTERNET);
+        final LinkProperties dunLp = dunAgent.linkProperties;
         dunLp.setInterfaceName("rmnet_data1");
         final String[] DUN_ADDRS = {
                 "192.0.2.48", "2001:db8:1:2:b50e:70d9:10c9:433d",
         };
         for (String addrStr : DUN_ADDRS) {
             final String cidr = addrStr.contains(":") ? "/64" : "/27";
-            cellLp.addLinkAddress(new LinkAddress(addrStr + cidr));
+            dunLp.addLinkAddress(new LinkAddress(addrStr + cidr));
         }
         dunAgent.fakeConnect();
-        dunAgent.sendLinkProperties(dunLp);
+        dunAgent.sendLinkProperties();
 
         local = mUNM.getLocalPrefixes();
         assertPrefixSet(local, INCLUDES, alreadySeen);
@@ -442,6 +497,7 @@ public class UpstreamNetworkMonitorTest {
     public static class TestConnectivityManager extends ConnectivityManager {
         public Map<NetworkCallback, Handler> allCallbacks = new HashMap<>();
         public Set<NetworkCallback> trackingDefault = new HashSet<>();
+        public TestNetworkAgent defaultNetwork = null;
         public Map<NetworkCallback, NetworkRequest> listening = new HashMap<>();
         public Map<NetworkCallback, NetworkRequest> requested = new HashMap<>();
         public Map<NetworkCallback, Integer> legacyTypeMap = new HashMap<>();
@@ -483,12 +539,34 @@ public class UpstreamNetworkMonitorTest {
 
         int getNetworkId() { return ++mNetworkId; }
 
+        void makeDefaultNetwork(TestNetworkAgent agent) {
+            if (Objects.equals(defaultNetwork, agent)) return;
+
+            final TestNetworkAgent formerDefault = defaultNetwork;
+            defaultNetwork = agent;
+
+            for (NetworkCallback cb : trackingDefault) {
+                if (defaultNetwork != null) {
+                    cb.onAvailable(defaultNetwork.networkId);
+                    cb.onCapabilitiesChanged(
+                            defaultNetwork.networkId, defaultNetwork.networkCapabilities);
+                    cb.onLinkPropertiesChanged(
+                            defaultNetwork.networkId, defaultNetwork.linkProperties);
+                }
+            }
+        }
+
         @Override
         public void requestNetwork(NetworkRequest req, NetworkCallback cb, Handler h) {
             assertFalse(allCallbacks.containsKey(cb));
             allCallbacks.put(cb, h);
-            assertFalse(requested.containsKey(cb));
-            requested.put(cb, req);
+            if (mDefaultRequest.equals(req)) {
+                assertFalse(trackingDefault.contains(cb));
+                trackingDefault.add(cb);
+            } else {
+                assertFalse(requested.containsKey(cb));
+                requested.put(cb, req);
+            }
         }
 
         @Override
@@ -524,10 +602,7 @@ public class UpstreamNetworkMonitorTest {
 
         @Override
         public void registerDefaultNetworkCallback(NetworkCallback cb, Handler h) {
-            assertFalse(allCallbacks.containsKey(cb));
-            allCallbacks.put(cb, h);
-            assertFalse(trackingDefault.contains(cb));
-            trackingDefault.add(cb);
+            fail("Should never be called.");
         }
 
         @Override
@@ -561,6 +636,7 @@ public class UpstreamNetworkMonitorTest {
         public final Network networkId;
         public final int transportType;
         public final NetworkCapabilities networkCapabilities;
+        public final LinkProperties linkProperties;
 
         public TestNetworkAgent(TestConnectivityManager cm, int transportType) {
             this.cm = cm;
@@ -569,12 +645,14 @@ public class UpstreamNetworkMonitorTest {
             networkCapabilities = new NetworkCapabilities();
             networkCapabilities.addTransportType(transportType);
             networkCapabilities.addCapability(NET_CAPABILITY_INTERNET);
+            linkProperties = new LinkProperties();
         }
 
         public void fakeConnect() {
             for (NetworkCallback cb : cm.listening.keySet()) {
                 cb.onAvailable(networkId);
                 cb.onCapabilitiesChanged(networkId, copy(networkCapabilities));
+                cb.onLinkPropertiesChanged(networkId, copy(linkProperties));
             }
         }
 
@@ -584,11 +662,16 @@ public class UpstreamNetworkMonitorTest {
             }
         }
 
-        public void sendLinkProperties(LinkProperties lp) {
+        public void sendLinkProperties() {
             for (NetworkCallback cb : cm.listening.keySet()) {
-                cb.onLinkPropertiesChanged(networkId, lp);
+                cb.onLinkPropertiesChanged(networkId, copy(linkProperties));
             }
         }
+
+        @Override
+        public String toString() {
+            return String.format("TestNetworkAgent: %s %s", networkId, networkCapabilities);
+        }
     }
 
     public static class TestStateMachine extends StateMachine {
@@ -618,6 +701,10 @@ public class UpstreamNetworkMonitorTest {
         return new NetworkCapabilities(nc);
     }
 
+    static LinkProperties copy(LinkProperties lp) {
+        return new LinkProperties(lp);
+    }
+
     static void assertPrefixSet(Set<IpPrefix> prefixes, boolean expectation, String... expected) {
         final Set<String> expectedSet = new HashSet<>();
         Collections.addAll(expectedSet, expected);