WifiScanner: Disallow scans when location is off

Don't allow system apps to request scans (using internal
WifiScanner) when location is turned off. We should however
process any scan requests from wifi service
(holding NETWORK_STACK) permissions for connectivity purposes.

While there, also refactored the code performing permission checks.

Note: The public WifiManager.startScan() has more stringent
permission checks that already include the location status check. So,
any requests from wifi service are already sanitized before being sent
to wifi scanner service.

Bug: 113542524
Test: Unit tests
Test: Ensured that the device is still able to connect to wifi networks,
see scan results in settings page when location is turned off.

Change-Id: I41a118feb232c51003c0644130019b14513d8088

1 files changed, 69 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 cf00069b5..1280013fe 100644
--- a/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/scanner/WifiScanningServiceTest.java
@@ -39,6 +39,7 @@ import static org.mockito.Mockito.anyBoolean;
 import static org.mockito.Mockito.anyInt;
 import static org.mockito.Mockito.anyString;
 import static org.mockito.Mockito.argThat;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.inOrder;
@@ -55,6 +56,7 @@ import android.app.test.MockAnswerUtil.AnswerWithArguments;
 import android.app.test.TestAlarmManager;
 import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.location.LocationManager;
 import android.net.wifi.ScanResult;
 import android.net.wifi.WifiScanner;
 import android.os.Binder;
@@ -120,6 +122,7 @@ public class WifiScanningServiceTest {
     @Mock FrameworkFacade mFrameworkFacade;
     @Mock Clock mClock;
     @Spy FakeWifiLog mLog;
+    @Mock LocationManager mLocationManager;
     WifiMetrics mWifiMetrics;
     TestLooper mLooper;
     WifiScanningServiceImpl mWifiScanningServiceImpl;
@@ -132,6 +135,8 @@ public class WifiScanningServiceTest {
         mAlarmManager = new TestAlarmManager();
         when(mContext.getSystemService(Context.ALARM_SERVICE))
                 .thenReturn(mAlarmManager.getAlarmManager());
+        when(mContext.getSystemService(Context.LOCATION_SERVICE))
+                .thenReturn(mLocationManager);
 
         ChannelHelper channelHelper = new PresetKnownBandsChannelHelper(
                 new int[]{2400, 2450},
@@ -393,6 +398,7 @@ public class WifiScanningServiceTest {
     private static final int MAX_AP_PER_SCAN = 16;
     private void startServiceAndLoadDriver() {
         mWifiScanningServiceImpl.startService();
+        mWifiScanningServiceImpl.setWifiHandlerLogForTest(mLog);
         setupAndLoadDriver(TEST_MAX_SCAN_BUCKETS_IN_CAPABILITIES);
     }
 
@@ -2462,6 +2468,7 @@ public class WifiScanningServiceTest {
     @Test
     public void rejectRestrictedMessagesFromNonPrivilegedApps() throws Exception {
         mWifiScanningServiceImpl.startService();
+        mWifiScanningServiceImpl.setWifiHandlerLogForTest(mLog);
         Handler handler = mock(Handler.class);
         BidirectionalAsyncChannel controlChannel = connectChannel(handler);
 
@@ -2498,4 +2505,66 @@ public class WifiScanningServiceTest {
         verify(mWifiScannerImplFactory, never()).create(any(), any(), any());
 
     }
+
+    /**
+     * Verifies that clients without NETWORK_STACK permission cannot issue any messages when
+     * location is turned off.
+     */
+    @Test
+    public void rejectAllMessagesFromNonPrivilegedAppsWhenLocationIsTurnedOff() throws Exception {
+        // Start service & initialize it.
+        startServiceAndLoadDriver();
+        // Location turned off.
+        when(mLocationManager.isLocationEnabled()).thenReturn(false);
+
+        Handler handler = mock(Handler.class);
+        BidirectionalAsyncChannel controlChannel = connectChannel(handler);
+
+        // Client doesn't have NETWORK_STACK permission.
+        doThrow(new SecurityException()).when(mContext).enforcePermission(
+                eq(Manifest.permission.NETWORK_STACK), anyInt(), eq(Binder.getCallingUid()), any());
+
+        controlChannel.sendMessage(Message.obtain(null, WifiScanner.CMD_START_SINGLE_SCAN));
+        mLooper.dispatchAll();
+
+        controlChannel.sendMessage(Message.obtain(null, WifiScanner.CMD_GET_SCAN_RESULTS));
+        mLooper.dispatchAll();
+
+        controlChannel.sendMessage(Message.obtain(null, WifiScanner.CMD_START_BACKGROUND_SCAN));
+        mLooper.dispatchAll();
+
+        // All the above messages should have been rejected because the app doesn't have
+        // the privileged permissions & location is turned off.
+        ArgumentCaptor<Message> messageCaptor = ArgumentCaptor.forClass(Message.class);
+        verify(handler, times(3)).handleMessage(messageCaptor.capture());
+        assertFailedResponse(0, WifiScanner.REASON_NOT_AUTHORIZED,
+                "Not authorized", messageCaptor.getAllValues().get(0));
+        assertFailedResponse(0, WifiScanner.REASON_NOT_AUTHORIZED,
+                "Not authorized", messageCaptor.getAllValues().get(1));
+        assertFailedResponse(0, WifiScanner.REASON_NOT_AUTHORIZED,
+                "Not authorized", messageCaptor.getAllValues().get(2));
+
+        // Validate the initialization sequence.
+        verify(mWifiScannerImpl).getChannelHelper();
+        verify(mWifiScannerImpl).getScanCapabilities(any());
+
+        // Ensure we didn't start any scans after.
+        verifyNoMoreInteractions(mWifiScannerImpl);
+    }
+
+    /**
+     * Verifies that clients with NETWORK_STACK permission can issue any messages even when
+     * location is turned off.
+     */
+    @Test
+    public void allowMessagesFromPrivilegedAppsWhenLocationIsTurnedOff() throws Exception {
+        // Location turned off.
+        when(mLocationManager.isLocationEnabled()).thenReturn(false);
+        // Client does have NETWORK_STACK permission.
+        doNothing().when(mContext).enforcePermission(
+                eq(Manifest.permission.NETWORK_STACK), anyInt(), eq(Binder.getCallingUid()), any());
+
+        sendSingleScanAllChannelsRequest();
+        sendBackgroundScanBandRequest();
+    }
 }