Check pending queue for cancelAuthentication

If cancelAuthentication is requested but actual authentication
has not started yet (e.g. a previous non-cancelable operation such
as updateActiveGroup or getAuthenticatorId is still running), look
through the pending queue and mark all matched authentication clients
as STATE_WAITING_IN_QUEUE_CANCELING.

Test: atest BiometricSchedulerTest
Fixes: 178105328
Change-Id: I755359adbdcda7f054135a190426b4a78a7a5125

services/core/java/com/android/server/biometrics/sensors/BiometricScheduler.java

@@ -563,14 +563,26 @@ public class BiometricScheduler {
         final boolean isAuthenticating =
                 mCurrentOperation.mClientMonitor instanceof AuthenticationConsumer;
         final boolean tokenMatches = mCurrentOperation.mClientMonitor.getToken() == token;
-        if (!isAuthenticating || !tokenMatches) {
-            Slog.w(getTag(), "Not cancelling authentication"
-                    + ", current operation : " + mCurrentOperation
-                    + ", tokenMatches: " + tokenMatches);
-            return;
-        }
 
-        cancelInternal(mCurrentOperation);
+        if (isAuthenticating && tokenMatches) {
+            Slog.d(getTag(), "Cancelling authentication: " + mCurrentOperation);
+            cancelInternal(mCurrentOperation);
+        } else if (!isAuthenticating) {
+            // Look through the current queue for all authentication clients for the specified
+            // token, and mark them as STATE_WAITING_IN_QUEUE_CANCELING. Note that we're marking
+            // all of them, instead of just the first one, since the API surface currently doesn't
+            // allow us to distinguish between multiple authentication requests from the same
+            // process. However, this generally does not happen anyway, and would be a class of
+            // bugs on its own.
+            for (Operation operation : mPendingOperations) {
+                if (operation.mClientMonitor instanceof AuthenticationConsumer
+                        && operation.mClientMonitor.getToken() == token) {
+                    Slog.d(getTag(), "Marking " + operation
+                            + " as STATE_WAITING_IN_QUEUE_CANCELING");
+                    operation.mState = Operation.STATE_WAITING_IN_QUEUE_CANCELING;
+                }
+            }
+        }
     }
 
     /**

services/tests/servicestests/src/com/android/server/biometrics/sensors/BiometricSchedulerTest.java

@@ -33,6 +33,7 @@ import android.hardware.biometrics.BiometricConstants;
 import android.hardware.biometrics.IBiometricService;
 import android.os.Binder;
 import android.os.IBinder;
+import android.os.RemoteException;
 import android.platform.test.annotations.Presubmit;
 
 import androidx.annotation.NonNull;
@@ -267,6 +268,39 @@ public class BiometricSchedulerTest {
         assertEquals(0, bsp.recentOperations.length);
     }
 
+    @Test
+    public void testCancelPendingAuth() throws RemoteException {
+        final HalClientMonitor.LazyDaemon<Object> lazyDaemon = () -> mock(Object.class);
+
+        final TestClientMonitor client1 = new TestClientMonitor(mContext, mToken, lazyDaemon);
+        final ClientMonitorCallbackConverter callback = mock(ClientMonitorCallbackConverter.class);
+        final TestAuthenticationClient client2 = new TestAuthenticationClient(mContext, lazyDaemon,
+                mToken, callback);
+
+        // Add a non-cancellable client, then add the auth client
+        mScheduler.scheduleClientMonitor(client1);
+        mScheduler.scheduleClientMonitor(client2);
+        waitForIdle();
+
+        assertEquals(mScheduler.getCurrentClient(), client1);
+        assertEquals(Operation.STATE_WAITING_IN_QUEUE,
+                mScheduler.mPendingOperations.getFirst().mState);
+
+        // Request cancel before the authentication client has started
+        mScheduler.cancelAuthentication(mToken);
+        waitForIdle();
+        assertEquals(Operation.STATE_WAITING_IN_QUEUE_CANCELING,
+                mScheduler.mPendingOperations.getFirst().mState);
+
+        // Finish the blocking client. The authentication client should send ERROR_CANCELED
+        client1.getCallback().onClientFinished(client1, true /* success */);
+        waitForIdle();
+        verify(callback).onError(anyInt(), anyInt(),
+                eq(BiometricConstants.BIOMETRIC_ERROR_CANCELED),
+                eq(0) /* vendorCode */);
+        assertNull(mScheduler.getCurrentClient());
+    }
+
     private BiometricSchedulerProto getDump(boolean clearSchedulerBuffer) throws Exception {
         return BiometricSchedulerProto.parseFrom(mScheduler.dumpProtoState(clearSchedulerBuffer));
     }
@@ -293,6 +327,29 @@ public class BiometricSchedulerTest {
         }
     }
 
+    private static class TestAuthenticationClient extends AuthenticationClient<Object> {
+
+        public TestAuthenticationClient(@NonNull Context context,
+                @NonNull LazyDaemon<Object> lazyDaemon, @NonNull IBinder token,
+                @NonNull ClientMonitorCallbackConverter listener) {
+            super(context, lazyDaemon, token, listener, 0 /* targetUserId */, 0 /* operationId */,
+                    false /* restricted */, TAG, 1 /* cookie */, false /* requireConfirmation */,
+                    TEST_SENSOR_ID, true /* isStrongBiometric */, 0 /* statsModality */,
+                    0 /* statsClient */, null /* taskStackListener */, mock(LockoutTracker.class),
+                    false /* isKeyguard */);
+        }
+
+        @Override
+        protected void stopHalOperation() {
+
+        }
+
+        @Override
+        protected void startHalOperation() {
+
+        }
+    }
+
     private static class TestClientMonitor2 extends TestClientMonitor {
         private final int mProtoEnum;