Clear process DNS NetID binding when expiring or releaseing legacy requests.

When requests made by ConnectivityManager.startUsingNetworkFeature() are
expired or are canceled via ConnectivityManager.stopUsingNetworkFeature(),
we must remember to clear the binding of DNS requests from the calling
process to the Network satisfying the request.

bug:18778725
Change-Id: I800c808ac6486000241b5d263aa79a1192a9fe9e

1 files changed, 18 insertions, 15 deletions

diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 17ee494622a0..cdc8661b1695 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -933,10 +933,8 @@ public class ConnectivityManager {
             return -1;
         }
 
-        NetworkCallback networkCallback = removeRequestForFeature(netCap);
-        if (networkCallback != null) {
+        if (removeRequestForFeature(netCap)) {
             Log.d(TAG, "stopUsingNetworkFeature for " + networkType + ", " + feature);
-            unregisterNetworkCallback(networkCallback);
         }
         return 1;
     }
@@ -1103,6 +1101,14 @@ public class ConnectivityManager {
         int expireSequenceNumber;
         Network currentNetwork;
         int delay = -1;
+
+        private void clearDnsBinding() {
+            if (currentNetwork != null) {
+                currentNetwork = null;
+                setProcessDefaultNetworkForHostResolution(null);
+            }
+        }
+
         NetworkCallback networkCallback = new NetworkCallback() {
             @Override
             public void onAvailable(Network network) {
@@ -1112,10 +1118,7 @@ public class ConnectivityManager {
             }
             @Override
             public void onLost(Network network) {
-                if (network.equals(currentNetwork)) {
-                    currentNetwork = null;
-                    setProcessDefaultNetworkForHostResolution(null);
-                }
+                if (network.equals(currentNetwork)) clearDnsBinding();
                 Log.d(TAG, "startUsingNetworkFeature lost Network:" + network);
             }
         };
@@ -1144,10 +1147,7 @@ public class ConnectivityManager {
             LegacyRequest l = sLegacyRequests.get(netCap);
             if (l == null) return;
             ourSeqNum = l.expireSequenceNumber;
-            if (l.expireSequenceNumber == sequenceNum) {
-                unregisterNetworkCallback(l.networkCallback);
-                sLegacyRequests.remove(netCap);
-            }
+            if (l.expireSequenceNumber == sequenceNum) removeRequestForFeature(netCap);
         }
         Log.d(TAG, "expireRequest with " + ourSeqNum + ", " + sequenceNum);
     }
@@ -1178,12 +1178,15 @@ public class ConnectivityManager {
         }
     }
 
-    private NetworkCallback removeRequestForFeature(NetworkCapabilities netCap) {
+    private boolean removeRequestForFeature(NetworkCapabilities netCap) {
+        final LegacyRequest l;
         synchronized (sLegacyRequests) {
-            LegacyRequest l = sLegacyRequests.remove(netCap);
-            if (l == null) return null;
-            return l.networkCallback;
+            l = sLegacyRequests.remove(netCap);
         }
+        if (l == null) return false;
+        unregisterNetworkCallback(l.networkCallback);
+        l.clearDnsBinding();
+        return true;
     }
 
     /**