| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.server.biometrics.sensors; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.content.Context; |
| import android.hardware.biometrics.BiometricsProtoEnums; |
| import android.os.IBinder; |
| import android.os.RemoteException; |
| import android.util.Slog; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| /** |
| * Abstract base class for keeping track and dispatching events from the biometric's HAL to the |
| * the current client. Subclasses are responsible for coordinating the interaction with |
| * the biometric's HAL for the specific action (e.g. authenticate, enroll, enumerate, etc.). |
| */ |
| public abstract class BaseClientMonitor extends LoggableMonitor |
| implements IBinder.DeathRecipient { |
| |
| private static final String TAG = "Biometrics/ClientMonitor"; |
| protected static final boolean DEBUG = true; |
| |
| // Counter used to distinguish between ClientMonitor instances to help debugging. |
| private static int sCount = 0; |
| |
| /** |
| * Interface that ClientMonitor holders should use to receive callbacks. |
| */ |
| public interface Callback { |
| |
| /** |
| * Invoked when the ClientMonitor operation has been started (e.g. reached the head of |
| * the queue and becomes the current operation). |
| * |
| * @param clientMonitor Reference of the ClientMonitor that is starting. |
| */ |
| default void onClientStarted(@NonNull BaseClientMonitor clientMonitor) { |
| } |
| |
| /** |
| * Invoked when the ClientMonitor operation is complete. This abstracts away asynchronous |
| * (i.e. Authenticate, Enroll, Enumerate, Remove) and synchronous (i.e. generateChallenge, |
| * revokeChallenge) so that a scheduler can process ClientMonitors regardless of their |
| * implementation. |
| * |
| * @param clientMonitor Reference of the ClientMonitor that finished. |
| * @param success True if the operation completed successfully. |
| */ |
| default void onClientFinished(@NonNull BaseClientMonitor clientMonitor, boolean success) { |
| } |
| } |
| |
| /** Holder for wrapping multiple handlers into a single Callback. */ |
| public static class CompositeCallback implements Callback { |
| @NonNull |
| private final List<Callback> mCallbacks; |
| |
| public CompositeCallback(@NonNull Callback... callbacks) { |
| mCallbacks = new ArrayList<>(); |
| |
| for (Callback callback : callbacks) { |
| if (callback != null) { |
| mCallbacks.add(callback); |
| } |
| } |
| } |
| |
| @Override |
| public final void onClientStarted(@NonNull BaseClientMonitor clientMonitor) { |
| for (int i = 0; i < mCallbacks.size(); i++) { |
| mCallbacks.get(i).onClientStarted(clientMonitor); |
| } |
| } |
| |
| @Override |
| public final void onClientFinished(@NonNull BaseClientMonitor clientMonitor, |
| boolean success) { |
| for (int i = mCallbacks.size() - 1; i >= 0; i--) { |
| mCallbacks.get(i).onClientFinished(clientMonitor, success); |
| } |
| } |
| } |
| |
| private final int mSequentialId; |
| @NonNull private final Context mContext; |
| private final int mTargetUserId; |
| @NonNull private final String mOwner; |
| private final int mSensorId; // sensorId as configured by the framework |
| |
| @Nullable private IBinder mToken; |
| private long mRequestId; |
| @Nullable private ClientMonitorCallbackConverter mListener; |
| // Currently only used for authentication client. The cookie generated by BiometricService |
| // is never 0. |
| private final int mCookie; |
| boolean mAlreadyDone; |
| |
| // Use an empty callback by default since delayed operations can receive events |
| // before they are started and cause NPE in subclasses that access this field directly. |
| @NonNull protected Callback mCallback = new Callback() { |
| @Override |
| public void onClientStarted(@NonNull BaseClientMonitor clientMonitor) { |
| Slog.e(TAG, "mCallback onClientStarted: called before set (should not happen)"); |
| } |
| |
| @Override |
| public void onClientFinished(@NonNull BaseClientMonitor clientMonitor, |
| boolean success) { |
| Slog.e(TAG, "mCallback onClientFinished: called before set (should not happen)"); |
| } |
| }; |
| |
| /** |
| * @return A ClientMonitorEnum constant defined in biometrics.proto |
| */ |
| public abstract int getProtoEnum(); |
| |
| /** |
| * @return True if the ClientMonitor should cancel any current and pending interruptable clients |
| */ |
| public boolean interruptsPrecedingClients() { |
| return false; |
| } |
| |
| /** |
| * @param context system_server context |
| * @param token a unique token for the client |
| * @param listener recipient of related events (e.g. authentication) |
| * @param userId target user id for operation |
| * @param owner name of the client that owns this |
| * @param cookie BiometricPrompt authentication cookie (to be moved into a subclass soon) |
| * @param sensorId ID of the sensor that the operation should be requested of |
| * @param statsModality One of {@link BiometricsProtoEnums} MODALITY_* constants |
| * @param statsAction One of {@link BiometricsProtoEnums} ACTION_* constants |
| * @param statsClient One of {@link BiometricsProtoEnums} CLIENT_* constants |
| */ |
| public BaseClientMonitor(@NonNull Context context, |
| @Nullable IBinder token, @Nullable ClientMonitorCallbackConverter listener, int userId, |
| @NonNull String owner, int cookie, int sensorId, int statsModality, int statsAction, |
| int statsClient) { |
| super(context, statsModality, statsAction, statsClient); |
| mSequentialId = sCount++; |
| mContext = context; |
| mToken = token; |
| mRequestId = -1; |
| mListener = listener; |
| mTargetUserId = userId; |
| mOwner = owner; |
| mCookie = cookie; |
| mSensorId = sensorId; |
| |
| try { |
| if (token != null) { |
| token.linkToDeath(this, 0); |
| } |
| } catch (RemoteException e) { |
| Slog.w(TAG, "caught remote exception in linkToDeath: ", e); |
| } |
| } |
| |
| public int getCookie() { |
| return mCookie; |
| } |
| |
| /** |
| * Starts the ClientMonitor's lifecycle. |
| * @param callback invoked when the operation is complete (succeeds, fails, etc) |
| */ |
| public void start(@NonNull Callback callback) { |
| mCallback = wrapCallbackForStart(callback); |
| mCallback.onClientStarted(this); |
| } |
| |
| /** |
| * Called during start to provide subclasses a hook for decorating the callback. |
| * |
| * Returns the original callback unless overridden. |
| */ |
| @NonNull |
| protected Callback wrapCallbackForStart(@NonNull Callback callback) { |
| return callback; |
| } |
| |
| public boolean isAlreadyDone() { |
| return mAlreadyDone; |
| } |
| |
| public void destroy() { |
| if (mToken != null) { |
| try { |
| mToken.unlinkToDeath(this, 0); |
| } catch (NoSuchElementException e) { |
| // TODO: remove when duplicate call bug is found |
| Slog.e(TAG, "destroy(): " + this + ":", new Exception("here")); |
| } |
| mToken = null; |
| } |
| } |
| |
| @Override |
| public void binderDied() { |
| binderDiedInternal(true /* clearListener */); |
| } |
| |
| // TODO(b/157790417): Move this to the scheduler |
| void binderDiedInternal(boolean clearListener) { |
| Slog.e(TAG, "Binder died, owner: " + getOwnerString() |
| + ", operation: " + this.getClass().getName()); |
| |
| if (isAlreadyDone()) { |
| Slog.w(TAG, "Binder died but client is finished, ignoring"); |
| return; |
| } |
| |
| // If the current client dies we should cancel the current operation. |
| if (this instanceof Interruptable) { |
| Slog.e(TAG, "Binder died, cancelling client"); |
| ((Interruptable) this).cancel(); |
| } |
| mToken = null; |
| if (clearListener) { |
| mListener = null; |
| } |
| } |
| |
| public final Context getContext() { |
| return mContext; |
| } |
| |
| public final String getOwnerString() { |
| return mOwner; |
| } |
| |
| public final ClientMonitorCallbackConverter getListener() { |
| return mListener; |
| } |
| |
| public int getTargetUserId() { |
| return mTargetUserId; |
| } |
| |
| public final IBinder getToken() { |
| return mToken; |
| } |
| |
| public int getSensorId() { |
| return mSensorId; |
| } |
| |
| /** Unique request id. */ |
| public final long getRequestId() { |
| return mRequestId; |
| } |
| |
| /** If a unique id has been set via {@link #setRequestId(long)} */ |
| public final boolean hasRequestId() { |
| return mRequestId > 0; |
| } |
| |
| /** |
| * A unique identifier used to tie this operation to a request (i.e an API invocation). |
| * |
| * Subclasses should not call this method if this operation does not have a direct |
| * correspondence to a request and {@link #hasRequestId()} will return false. |
| */ |
| protected final void setRequestId(long id) { |
| if (id <= 0) { |
| throw new IllegalArgumentException("request id must be positive"); |
| } |
| mRequestId = id; |
| } |
| |
| @VisibleForTesting |
| public Callback getCallback() { |
| return mCallback; |
| } |
| |
| @Override |
| public String toString() { |
| return "{[" + mSequentialId + "] " |
| + this.getClass().getSimpleName() |
| + ", proto=" + getProtoEnum() |
| + ", owner=" + getOwnerString() |
| + ", cookie=" + getCookie() |
| + ", requestId=" + getRequestId() |
| + ", userId=" + getTargetUserId() + "}"; |
| } |
| } |