Ignore disconnect messages that don't indicate the channel is dead

Bug: 29368784
Test: mmma frameworks/opt/net/wifi/tests && runtest frameworks-wifi
Change-Id: I5ae3665898565379b101c4ac0c5570c9debb1228

2 files changed, 56 insertions, 3 deletions

diff --git a/service/java/com/android/server/wifi/scanner/WifiScanningServiceImpl.java b/service/java/com/android/server/wifi/scanner/WifiScanningServiceImpl.java
index 6ae223717..9f8fb2f58 100644
--- a/service/java/com/android/server/wifi/scanner/WifiScanningServiceImpl.java
+++ b/service/java/com/android/server/wifi/scanner/WifiScanningServiceImpl.java
@@ -164,7 +164,9 @@ public class WifiScanningServiceImpl extends IWifiScanner.Stub {
                 }
                 case AsyncChannel.CMD_CHANNEL_DISCONNECTED: {
                     ExternalClientInfo client = (ExternalClientInfo) mClients.get(msg.replyTo);
-                    if (client != null) {
+                    if (client != null && msg.arg1 != AsyncChannel.STATUS_SEND_UNSUCCESSFUL
+                            && msg.arg1
+                            != AsyncChannel.STATUS_FULL_CONNECTION_REFUSED_ALREADY_CONNECTED) {
                         localLog("client disconnected: " + client + ", reason: " + msg.arg1);
                         client.cleanup();
                     }
diff --git a/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java b/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
index b18e4cc61..3498b53fc 100644
--- a/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
@@ -1667,8 +1667,8 @@ public class WifiScanningServiceTest {
         sendSingleScanRequest(controlChannel, requestId, requestSettings, null);
         // Can't call |disconnect| here because that sends |CMD_CHANNEL_DISCONNECT| followed by
         // |CMD_CHANNEL_DISCONNECTED|.
-        controlChannel.sendMessage(Message.obtain(null, AsyncChannel.CMD_CHANNEL_DISCONNECTED, 0,
-                0, null));
+        controlChannel.sendMessage(Message.obtain(null, AsyncChannel.CMD_CHANNEL_DISCONNECTED,
+                        AsyncChannel.STATUS_REMOTE_DISCONNECTION, 0, null));
 
         // Now process the above 2 actions. This should result in first processing the single scan
         // request (which forwards the request to SingleScanStateMachine) and then processing the
@@ -1683,4 +1683,55 @@ public class WifiScanningServiceTest {
                 logLineRegex.matcher(serviceDump).find());
     }
 
+    /**
+     * Tries to simulate the race scenario where a client is disconnected immediately after single
+     * scan request is sent to |SingleScanStateMachine|.
+     */
+    @Test
+    public void sendScanRequestAfterUnsuccessfulSend() throws Exception {
+        WifiScanner.ScanSettings requestSettings = createRequest(WifiScanner.WIFI_BAND_BOTH, 0,
+                0, 20, WifiScanner.REPORT_EVENT_AFTER_EACH_SCAN);
+        int requestId = 9;
+
+        startServiceAndLoadDriver();
+        Handler handler = mock(Handler.class);
+        BidirectionalAsyncChannel controlChannel = connectChannel(handler);
+        mLooper.dispatchAll();
+
+        when(mWifiScannerImpl.startSingleScan(any(WifiNative.ScanSettings.class),
+                        any(WifiNative.ScanEventHandler.class))).thenReturn(true);
+        ScanResults results = ScanResults.create(0, 2400);
+        when(mWifiScannerImpl.getLatestSingleScanResults())
+                .thenReturn(results.getRawScanData());
+
+        InOrder order = inOrder(mWifiScannerImpl, handler);
+
+        sendSingleScanRequest(controlChannel, requestId, requestSettings, null);
+        mLooper.dispatchAll();
+        WifiNative.ScanEventHandler eventHandler1 = verifyStartSingleScan(order,
+                computeSingleScanNativeSettings(requestSettings));
+        verifySuccessfulResponse(order, handler, requestId);
+
+        eventHandler1.onScanStatus(WifiNative.WIFI_SCAN_RESULTS_AVAILABLE);
+        mLooper.dispatchAll();
+        verifyScanResultsRecieved(order, handler, requestId, results.getScanData());
+        verifySingleScanCompletedRecieved(order, handler, requestId);
+        verifyNoMoreInteractions(handler);
+
+        controlChannel.sendMessage(Message.obtain(null, AsyncChannel.CMD_CHANNEL_DISCONNECTED,
+                        AsyncChannel.STATUS_SEND_UNSUCCESSFUL, 0, null));
+        mLooper.dispatchAll();
+
+        sendSingleScanRequest(controlChannel, requestId, requestSettings, null);
+        mLooper.dispatchAll();
+        WifiNative.ScanEventHandler eventHandler2 = verifyStartSingleScan(order,
+                computeSingleScanNativeSettings(requestSettings));
+        verifySuccessfulResponse(order, handler, requestId);
+
+        eventHandler2.onScanStatus(WifiNative.WIFI_SCAN_RESULTS_AVAILABLE);
+        mLooper.dispatchAll();
+        verifyScanResultsRecieved(order, handler, requestId, results.getScanData());
+        verifySingleScanCompletedRecieved(order, handler, requestId);
+        verifyNoMoreInteractions(handler);
+    }
 }