| /** |
| * Copyright (c) 2016, 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.utils; |
| |
| import android.annotation.NonNull; |
| import android.app.PendingIntent; |
| import android.content.ComponentName; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.ServiceConnection; |
| import android.os.IBinder; |
| import android.os.IBinder.DeathRecipient; |
| import android.os.IInterface; |
| import android.os.RemoteException; |
| import android.os.UserHandle; |
| import android.util.Slog; |
| |
| import java.util.Objects; |
| |
| /** |
| * Manages the lifecycle of an application-provided service bound from system server. |
| * |
| * @hide |
| */ |
| public class ManagedApplicationService { |
| private final String TAG = getClass().getSimpleName(); |
| |
| private final Context mContext; |
| private final int mUserId; |
| private final ComponentName mComponent; |
| private final int mClientLabel; |
| private final String mSettingsAction; |
| private final BinderChecker mChecker; |
| |
| private final DeathRecipient mDeathRecipient = new DeathRecipient() { |
| @Override |
| public void binderDied() { |
| synchronized (mLock) { |
| mBoundInterface = null; |
| } |
| } |
| }; |
| |
| private final Object mLock = new Object(); |
| |
| // State protected by mLock |
| private ServiceConnection mPendingConnection; |
| private ServiceConnection mConnection; |
| private IInterface mBoundInterface; |
| private PendingEvent mPendingEvent; |
| |
| private ManagedApplicationService(final Context context, final ComponentName component, |
| final int userId, int clientLabel, String settingsAction, |
| BinderChecker binderChecker) { |
| mContext = context; |
| mComponent = component; |
| mUserId = userId; |
| mClientLabel = clientLabel; |
| mSettingsAction = settingsAction; |
| mChecker = binderChecker; |
| } |
| |
| /** |
| * Implement to validate returned IBinder instance. |
| */ |
| public interface BinderChecker { |
| IInterface asInterface(IBinder binder); |
| boolean checkType(IInterface service); |
| } |
| |
| /** |
| * Implement to call IInterface methods after service is connected. |
| */ |
| public interface PendingEvent { |
| void runEvent(IInterface service) throws RemoteException; |
| } |
| |
| /** |
| * Create a new ManagedApplicationService object but do not yet bind to the user service. |
| * |
| * @param context a Context to use for binding the application service. |
| * @param component the {@link ComponentName} of the application service to bind. |
| * @param userId the user ID of user to bind the application service as. |
| * @param clientLabel the resource ID of a label displayed to the user indicating the |
| * binding service. |
| * @param settingsAction an action that can be used to open the Settings UI to enable/disable |
| * binding to these services. |
| * @param binderChecker an interface used to validate the returned binder object. |
| * @return a ManagedApplicationService instance. |
| */ |
| public static ManagedApplicationService build(@NonNull final Context context, |
| @NonNull final ComponentName component, final int userId, @NonNull int clientLabel, |
| @NonNull String settingsAction, @NonNull BinderChecker binderChecker) { |
| return new ManagedApplicationService(context, component, userId, clientLabel, |
| settingsAction, binderChecker); |
| } |
| |
| /** |
| * @return the user ID of the user that owns the bound service. |
| */ |
| public int getUserId() { |
| return mUserId; |
| } |
| |
| /** |
| * @return the component of the bound service. |
| */ |
| public ComponentName getComponent() { |
| return mComponent; |
| } |
| |
| /** |
| * Asynchronously unbind from the application service if the bound service component and user |
| * does not match the given signature. |
| * |
| * @param componentName the component that must match. |
| * @param userId the user ID that must match. |
| * @return {@code true} if not matching. |
| */ |
| public boolean disconnectIfNotMatching(final ComponentName componentName, final int userId) { |
| if (matches(componentName, userId)) { |
| return false; |
| } |
| disconnect(); |
| return true; |
| } |
| |
| |
| /** |
| * Send an event to run as soon as the binder interface is available. |
| * |
| * @param event a {@link PendingEvent} to send. |
| */ |
| public void sendEvent(@NonNull PendingEvent event) { |
| IInterface iface; |
| synchronized (mLock) { |
| iface = mBoundInterface; |
| if (iface == null) { |
| mPendingEvent = event; |
| } |
| } |
| |
| if (iface != null) { |
| try { |
| event.runEvent(iface); |
| } catch (RuntimeException | RemoteException ex) { |
| Slog.e(TAG, "Received exception from user service: ", ex); |
| } |
| } |
| } |
| |
| /** |
| * Asynchronously unbind from the application service if bound. |
| */ |
| public void disconnect() { |
| synchronized (mLock) { |
| // Wipe out pending connections |
| mPendingConnection = null; |
| |
| // Unbind existing connection, if it exists |
| if (mConnection != null) { |
| mContext.unbindService(mConnection); |
| mConnection = null; |
| } |
| |
| mBoundInterface = null; |
| } |
| } |
| |
| /** |
| * Asynchronously bind to the application service if not bound. |
| */ |
| public void connect() { |
| synchronized (mLock) { |
| if (mConnection != null || mPendingConnection != null) { |
| // We're already connected or are trying to connect |
| return; |
| } |
| |
| final PendingIntent pendingIntent = PendingIntent.getActivity( |
| mContext, 0, new Intent(mSettingsAction), 0); |
| final Intent intent = new Intent().setComponent(mComponent). |
| putExtra(Intent.EXTRA_CLIENT_LABEL, mClientLabel). |
| putExtra(Intent.EXTRA_CLIENT_INTENT, pendingIntent); |
| |
| final ServiceConnection serviceConnection = new ServiceConnection() { |
| @Override |
| public void onServiceConnected(ComponentName componentName, IBinder iBinder) { |
| IInterface iface = null; |
| PendingEvent pendingEvent = null; |
| synchronized (mLock) { |
| if (mPendingConnection == this) { |
| // No longer pending, remove from pending connection |
| mPendingConnection = null; |
| mConnection = this; |
| } else { |
| // Service connection wasn't pending, must have been disconnected |
| mContext.unbindService(this); |
| return; |
| } |
| |
| try { |
| iBinder.linkToDeath(mDeathRecipient, 0); |
| mBoundInterface = mChecker.asInterface(iBinder); |
| if (!mChecker.checkType(mBoundInterface)) { |
| // Received an invalid binder, disconnect |
| mContext.unbindService(this); |
| mBoundInterface = null; |
| } |
| iface = mBoundInterface; |
| pendingEvent = mPendingEvent; |
| mPendingEvent = null; |
| } catch (RemoteException e) { |
| // DOA |
| Slog.w(TAG, "Unable to bind service: " + intent, e); |
| mBoundInterface = null; |
| } |
| } |
| if (iface != null && pendingEvent != null) { |
| try { |
| pendingEvent.runEvent(iface); |
| } catch (RuntimeException | RemoteException ex) { |
| Slog.e(TAG, "Received exception from user service: ", ex); |
| } |
| } |
| } |
| |
| @Override |
| public void onServiceDisconnected(ComponentName componentName) { |
| Slog.w(TAG, "Service disconnected: " + intent); |
| mConnection = null; |
| mBoundInterface = null; |
| } |
| }; |
| |
| mPendingConnection = serviceConnection; |
| |
| try { |
| if (!mContext.bindServiceAsUser(intent, serviceConnection, |
| Context.BIND_AUTO_CREATE | Context.BIND_FOREGROUND_SERVICE, |
| new UserHandle(mUserId))) { |
| Slog.w(TAG, "Unable to bind service: " + intent); |
| } |
| } catch (SecurityException e) { |
| Slog.w(TAG, "Unable to bind service: " + intent, e); |
| } |
| } |
| } |
| |
| private boolean matches(final ComponentName component, final int userId) { |
| return Objects.equals(mComponent, component) && mUserId == userId; |
| } |
| } |