WifiScanningServiceImpl: Handle race on iface removal

If there is a scan completion event as the iface is being removed,
mScannerImpls will contain an empty list when trying to report the
results. Return a scan failure instead because we can't fetch the real scan
results since the iface is no longer there.

Bug: 142469675
Test: atest com.android.server.wifi.scanner

Change-Id: I673e7562196fdb9660e74c520478a10ad5d05e45

1 files changed, 40 insertions, 0 deletions

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 931335205..67a54ba82 100644
--- a/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
@@ -1088,6 +1088,46 @@ public class WifiScanningServiceTest extends WifiBaseTest {
     }
 
     /**
+     * Send a single scan request and then disable Wi-Fi before it completes
+     */
+    @Test
+    public void sendSingleScanRequestThenDisableWifiAfterScanCompleteButBeforeReportingResults() {
+        WifiScanner.ScanSettings requestSettings = createRequest(channelsToSpec(2400), 0,
+                0, 20, WifiScanner.REPORT_EVENT_AFTER_EACH_SCAN);
+        ScanResults results = ScanResults.create(0, WifiScanner.WIFI_BAND_UNSPECIFIED, 2400);
+        int requestId = 2293;
+
+        startServiceAndLoadDriver();
+        mWifiScanningServiceImpl.setWifiHandlerLogForTest(mLog);
+
+        when(mWifiScannerImpl0.startSingleScan(any(WifiNative.ScanSettings.class),
+                any(WifiNative.ScanEventHandler.class))).thenReturn(true);
+
+        Handler handler = mock(Handler.class);
+        BidirectionalAsyncChannel controlChannel = connectChannel(handler);
+        InOrder order = inOrder(handler, mWifiScannerImpl0);
+
+        // Run scan 1
+        sendSingleScanRequest(controlChannel, requestId, requestSettings, null);
+        mLooper.dispatchAll();
+        WifiNative.ScanEventHandler eventHandler = verifyStartSingleScan(order,
+                computeSingleScanNativeSettings(requestSettings));
+        verifySuccessfulResponse(order, handler, requestId);
+
+        // disable wifi
+        controlChannel.sendMessage(Message.obtain(null, WifiScanner.CMD_DISABLE));
+        // scan results complete event
+        when(mWifiScannerImpl0.getLatestSingleScanResults())
+                .thenReturn(results.getScanData());
+        eventHandler.onScanStatus(WifiNative.WIFI_SCAN_RESULTS_AVAILABLE);
+
+        mLooper.dispatchAll();
+        verifyFailedResponse(order, handler, requestId, WifiScanner.REASON_UNSPECIFIED,
+                "Scan was interrupted");
+        verifyNoMoreInteractions(handler);
+    }
+
+    /**
      * Send a single scan request, schedule a second pending scan and disable Wi-Fi before the first
      * scan completes.
      */