Also support 464xlat on SUSPENDED networks

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
Bug: 65684232

Change-Id: I1b10aab01554b1f926ec7157dba78645fdaff90f

services/core/java/com/android/server/ConnectivityService.java

@@ -130,7 +130,6 @@ import com.android.server.connectivity.DataConnectionStats;
 import com.android.server.connectivity.KeepaliveTracker;
 import com.android.server.connectivity.LingerMonitor;
 import com.android.server.connectivity.MockableSystemProperties;
-import com.android.server.connectivity.Nat464Xlat;
 import com.android.server.connectivity.NetworkAgentInfo;
 import com.android.server.connectivity.NetworkDiagnostics;
 import com.android.server.connectivity.NetworkMonitor;

services/core/java/com/android/server/connectivity/Nat464Xlat.java

@@ -20,6 +20,7 @@ import android.net.InterfaceConfiguration;
 import android.net.ConnectivityManager;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
+import android.net.NetworkInfo;
 import android.net.RouteInfo;
 import android.os.INetworkManagementService;
 import android.os.RemoteException;
@@ -44,12 +45,18 @@ public class Nat464Xlat extends BaseNetworkObserver {
     // This must match the interface prefix in clatd.c.
     private static final String CLAT_PREFIX = "v4-";
 
-    // The network types we will start clatd on,
+    // The network types on which we will start clatd,
     // allowing clat only on networks for which we can support IPv6-only.
     private static final int[] NETWORK_TYPES = {
-            ConnectivityManager.TYPE_MOBILE,
-            ConnectivityManager.TYPE_WIFI,
-            ConnectivityManager.TYPE_ETHERNET,
+        ConnectivityManager.TYPE_MOBILE,
+        ConnectivityManager.TYPE_WIFI,
+        ConnectivityManager.TYPE_ETHERNET,
+    };
+
+    // The network states in which running clatd is supported.
+    private static final NetworkInfo.State[] NETWORK_STATES = {
+        NetworkInfo.State.CONNECTED,
+        NetworkInfo.State.SUSPENDED,
     };
 
     private final INetworkManagementService mNMService;
@@ -81,11 +88,8 @@ public class Nat464Xlat extends BaseNetworkObserver {
      */
     public static boolean requiresClat(NetworkAgentInfo nai) {
         // TODO: migrate to NetworkCapabilities.TRANSPORT_*.
-        final int netType = nai.networkInfo.getType();
         final boolean supported = ArrayUtils.contains(NETWORK_TYPES, nai.networkInfo.getType());
-        // TODO: this should also consider if the network is in SUSPENDED state to avoid stopping
-        // clatd in SUSPENDED state.
-        final boolean connected = nai.networkInfo.isConnected();
+        final boolean connected = ArrayUtils.contains(NETWORK_STATES, nai.networkInfo.getState());
         // We only run clat on networks that don't have a native IPv4 address.
         final boolean hasIPv4Address =
                 (nai.linkProperties != null) && nai.linkProperties.hasIPv4Address();

tests/net/java/com/android/server/connectivity/Nat464XlatTest.java

@@ -84,6 +84,32 @@ public class Nat464XlatTest {
         when(mConfig.getLinkAddress()).thenReturn(ADDR);
     }
 
+    @Test
+    public void testRequiresClat() throws Exception {
+        final int[] supportedTypes = {
+            ConnectivityManager.TYPE_MOBILE,
+            ConnectivityManager.TYPE_WIFI,
+            ConnectivityManager.TYPE_ETHERNET,
+        };
+
+        // NetworkInfo doesn't allow setting the State directly, but rather
+        // requires setting DetailedState in order set State as a side-effect.
+        final NetworkInfo.DetailedState[] supportedDetailedStates = {
+            NetworkInfo.DetailedState.CONNECTED,
+            NetworkInfo.DetailedState.SUSPENDED,
+        };
+
+        for (int type : supportedTypes) {
+            mNai.networkInfo.setType(type);
+            for (NetworkInfo.DetailedState state : supportedDetailedStates) {
+                mNai.networkInfo.setDetailedState(state, "reason", "extraInfo");
+                assertTrue(
+                        String.format("requiresClat expected for type=%d state=%s", type, state),
+                        Nat464Xlat.requiresClat(mNai));
+            }
+        }
+    }
+
     @Test
     public void testNormalStartAndStop() throws Exception {
         Nat464Xlat nat = makeNat464Xlat();