Update tethered/local only interfaces when no all networks request

If there is no request for all networks, the tethered/local only
interface changes will be ignored. However, these available
interfaces are not used for mDNS when a user requests a socket
with a null network because the interfaces are lost due to the
previous ignore. Therefore, the interface changes should be
retained and will be used for socket creations afterwards.

Bug: 284939720
Test: atest FrameworksNetTests android.net.cts.NsdManagerTest
Change-Id: If830eb53af26f21f497314477b131ce28468a971

service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java

@@ -449,11 +449,13 @@ public class MdnsSocketProvider {
         if (!hasAllNetworksRequest()) {
             // Currently, the network for tethering can not be requested, so the sockets for
             // tethering are only created if there is a request for all networks (interfaces).
-            // Therefore, this change can skip if there is no such request.
+            // Therefore, only update the interface list and skip this change if no such request.
             if (DBG) {
                 Log.d(TAG, "Ignore tether interfaces change. There is no request for all"
                         + " networks.");
             }
+            current.clear();
+            current.addAll(updated);
             return;
         }
 

tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java

@@ -745,4 +745,21 @@ public class MdnsSocketProviderTest {
                 List.of(WIFI_P2P_IFACE_NAME)));
         testCallback.expectedNoCallback();
     }
+
+    @Test
+    public void testTetherInterfacesChangedBeforeGetAllNetworksRequest() {
+        startMonitoringSockets();
+
+        // Receive an interface added change for the wifi p2p interface. Expect a socket creation
+        // callback.
+        runOnHandler(() -> mTetheringEventCallback.onLocalOnlyInterfacesChanged(
+                List.of(TETHERED_IFACE_NAME)));
+        verify(mTetheredIfaceWrapper, never()).getNetworkInterface();
+
+        // Request a socket with null network.
+        final TestSocketCallback testCallback = new TestSocketCallback();
+        runOnHandler(() -> mSocketProvider.requestSocket(null /* network */, testCallback));
+        verify(mTetheredIfaceWrapper).getNetworkInterface();
+        testCallback.expectedSocketCreatedForNetwork(null /* network */, List.of());
+    }
 }