Stop monitoring sockets until all sockets are unrequested
Now MdnsSocketProvider is stopped when there is no client request
left in NsdService, but this does not trigger
SocketCallback.onInterfaceDestroyed callbacks. If the network of
the socket is then lost while MdnsSocketProvider is not
monitoring, no callback will be fired. Users of the socket
(MdnsDiscoveryManager and MdnsAdvertiser) may keep using it
without ever getting notified. So ignore the stop and wait until
all sockets are unrequested. Then the socket destroy should be
notified to all users.
Bug: 267978487
Test: atest FrameworksNetTests
Change-Id: I7a8bb0550262fe397b91f1236a8dbca1cf2c7518
diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index 4ad39e1..8e06fde 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -317,7 +317,7 @@
if (!mIsMonitoringSocketsStarted) return;
if (isAnyRequestActive()) return;
- mMdnsSocketProvider.stopMonitoringSockets();
+ mMdnsSocketProvider.requestStopWhenInactive();
mIsMonitoringSocketsStarted = false;
}
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
index 9298852..743f946 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
@@ -82,6 +82,7 @@
private final List<String> mTetheredInterfaces = new ArrayList<>();
private final byte[] mPacketReadBuffer = new byte[READ_BUFFER_SIZE];
private boolean mMonitoringSockets = false;
+ private boolean mRequestStop = false;
public MdnsSocketProvider(@NonNull Context context, @NonNull Looper looper) {
this(context, looper, new Dependencies());
@@ -179,6 +180,7 @@
/*** Start monitoring sockets by listening callbacks for sockets creation or removal */
public void startMonitoringSockets() {
ensureRunningOnHandlerThread(mHandler);
+ mRequestStop = false; // Reset stop request flag.
if (mMonitoringSockets) {
Log.d(TAG, "Already monitoring sockets.");
return;
@@ -195,22 +197,34 @@
mMonitoringSockets = true;
}
- /*** Stop monitoring sockets and unregister callbacks */
- public void stopMonitoringSockets() {
+ private void maybeStopMonitoringSockets() {
+ if (!mMonitoringSockets) return; // Already unregistered.
+ if (!mRequestStop) return; // No stop request.
+
+ // Only unregister the network callback if there is no socket request.
+ if (mCallbacksToRequestedNetworks.isEmpty()) {
+ mContext.getSystemService(ConnectivityManager.class)
+ .unregisterNetworkCallback(mNetworkCallback);
+
+ final TetheringManager tetheringManager = mContext.getSystemService(
+ TetheringManager.class);
+ tetheringManager.unregisterTetheringEventCallback(mTetheringEventCallback);
+
+ mHandler.post(mNetlinkMonitor::stop);
+ mMonitoringSockets = false;
+ }
+ }
+
+ /*** Request to stop monitoring sockets and unregister callbacks */
+ public void requestStopWhenInactive() {
ensureRunningOnHandlerThread(mHandler);
if (!mMonitoringSockets) {
Log.d(TAG, "Monitoring sockets hasn't been started.");
return;
}
- if (DBG) Log.d(TAG, "Stop monitoring sockets.");
- mContext.getSystemService(ConnectivityManager.class)
- .unregisterNetworkCallback(mNetworkCallback);
-
- final TetheringManager tetheringManager = mContext.getSystemService(TetheringManager.class);
- tetheringManager.unregisterTetheringEventCallback(mTetheringEventCallback);
-
- mHandler.post(mNetlinkMonitor::stop);
- mMonitoringSockets = false;
+ if (DBG) Log.d(TAG, "Try to stop monitoring sockets.");
+ mRequestStop = true;
+ maybeStopMonitoringSockets();
}
/*** Check whether the target network is matched current network */
@@ -450,6 +464,9 @@
cb.onInterfaceDestroyed(new Network(INetd.LOCAL_NET_ID), info.mSocket);
}
mTetherInterfaceSockets.clear();
+
+ // Try to unregister network callback.
+ maybeStopMonitoringSockets();
}
/*** Callbacks for listening socket changes */