| /* |
| * Copyright (C) 2019 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 android.service.watchdog; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.SdkConstant; |
| import android.annotation.SystemApi; |
| import android.app.Service; |
| import android.content.Intent; |
| import android.os.Bundle; |
| import android.os.Handler; |
| import android.os.IBinder; |
| import android.os.Looper; |
| import android.os.RemoteCallback; |
| import android.os.RemoteException; |
| import android.util.Log; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Objects; |
| |
| /** |
| * A service to provide packages supporting explicit health checks and route checks to these |
| * packages on behalf of the package watchdog. |
| * |
| * <p>To extend this class, you must declare the service in your manifest file with the |
| * {@link android.Manifest.permission#BIND_EXPLICIT_HEALTH_CHECK_SERVICE} permission, |
| * and include an intent filter with the {@link #SERVICE_INTERFACE} action. In adddition, |
| * your implementation must live in {@link PackageManger#SYSTEM_SHARED_LIBRARY_SERVICES}. |
| * For example:</p> |
| * <pre> |
| * <service android:name=".FooExplicitHealthCheckService" |
| * android:exported="true" |
| * android:priority="100" |
| * android:permission="android.permission.BIND_EXPLICIT_HEALTH_CHECK_SERVICE"> |
| * <intent-filter> |
| * <action android:name="android.service.watchdog.ExplicitHealthCheckService" /> |
| * </intent-filter> |
| * </service> |
| * </pre> |
| * @hide |
| */ |
| @SystemApi |
| public abstract class ExplicitHealthCheckService extends Service { |
| |
| private static final String TAG = "ExplicitHealthCheckService"; |
| |
| /** |
| * {@link Bundle} key for a {@link List} of {@link String} value. |
| * |
| * {@hide} |
| */ |
| public static final String EXTRA_SUPPORTED_PACKAGES = |
| "android.service.watchdog.extra.supported_packages"; |
| |
| /** |
| * {@link Bundle} key for a {@link List} of {@link String} value. |
| * |
| * {@hide} |
| */ |
| public static final String EXTRA_REQUESTED_PACKAGES = |
| "android.service.watchdog.extra.requested_packages"; |
| |
| /** |
| * {@link Bundle} key for a {@link String} value. |
| * |
| * {@hide} |
| */ |
| public static final String EXTRA_HEALTH_CHECK_PASSED_PACKAGE = |
| "android.service.watchdog.extra.health_check_passed_package"; |
| |
| /** |
| * The Intent action that a service must respond to. Add it to the intent filter of the service |
| * in its manifest. |
| */ |
| @SdkConstant(SdkConstant.SdkConstantType.SERVICE_ACTION) |
| public static final String SERVICE_INTERFACE = |
| "android.service.watchdog.ExplicitHealthCheckService"; |
| |
| /** |
| * The permission that a service must require to ensure that only Android system can bind to it. |
| * If this permission is not enforced in the AndroidManifest of the service, the system will |
| * skip that service. |
| */ |
| public static final String BIND_PERMISSION = |
| "android.permission.BIND_EXPLICIT_HEALTH_CHECK_SERVICE"; |
| |
| private final ExplicitHealthCheckServiceWrapper mWrapper = |
| new ExplicitHealthCheckServiceWrapper(); |
| |
| /** |
| * Called when the system requests an explicit health check for {@code packageName}. |
| * |
| * <p> When {@code packageName} passes the check, implementors should call |
| * {@link #notifyHealthCheckPassed} to inform the system. |
| * |
| * <p> It could take many hours before a {@code packageName} passes a check and implementors |
| * should never drop requests unless {@link onCancel} is called or the service dies. |
| * |
| * <p> Requests should not be queued and additional calls while expecting a result for |
| * {@code packageName} should have no effect. |
| */ |
| public abstract void onRequestHealthCheck(@NonNull String packageName); |
| |
| /** |
| * Called when the system cancels the explicit health check request for {@code packageName}. |
| * Should do nothing if there are is no active request for {@code packageName}. |
| */ |
| public abstract void onCancelHealthCheck(@NonNull String packageName); |
| |
| /** |
| * Called when the system requests for all the packages supporting explicit health checks. The |
| * system may request an explicit health check for any of these packages with |
| * {@link #onRequestHealthCheck}. |
| * |
| * @return all packages supporting explicit health checks |
| */ |
| @NonNull public abstract List<String> onGetSupportedPackages(); |
| |
| /** |
| * Called when the system requests for all the packages that it has currently requested |
| * an explicit health check for. |
| * |
| * @return all packages expecting an explicit health check result |
| */ |
| @NonNull public abstract List<String> onGetRequestedPackages(); |
| |
| private final Handler mHandler = new Handler(Looper.getMainLooper(), null, true); |
| @Nullable private RemoteCallback mCallback; |
| |
| @Override |
| @NonNull |
| public final IBinder onBind(@NonNull Intent intent) { |
| return mWrapper; |
| } |
| |
| /** |
| * Implementors should call this to notify the system when explicit health check passes |
| * for {@code packageName}; |
| */ |
| public final void notifyHealthCheckPassed(@NonNull String packageName) { |
| mHandler.post(() -> { |
| if (mCallback != null) { |
| Objects.requireNonNull(packageName, |
| "Package passing explicit health check must be non-null"); |
| Bundle bundle = new Bundle(); |
| bundle.putString(EXTRA_HEALTH_CHECK_PASSED_PACKAGE, packageName); |
| mCallback.sendResult(bundle); |
| } else { |
| Log.wtf(TAG, "System missed explicit health check result for " + packageName); |
| } |
| }); |
| } |
| |
| private class ExplicitHealthCheckServiceWrapper extends IExplicitHealthCheckService.Stub { |
| @Override |
| public void setCallback(RemoteCallback callback) throws RemoteException { |
| mHandler.post(() -> { |
| mCallback = callback; |
| }); |
| } |
| |
| @Override |
| public void request(String packageName) throws RemoteException { |
| mHandler.post(() -> ExplicitHealthCheckService.this.onRequestHealthCheck(packageName)); |
| } |
| |
| @Override |
| public void cancel(String packageName) throws RemoteException { |
| mHandler.post(() -> ExplicitHealthCheckService.this.onCancelHealthCheck(packageName)); |
| } |
| |
| @Override |
| public void getSupportedPackages(RemoteCallback callback) throws RemoteException { |
| mHandler.post(() -> sendPackages(callback, EXTRA_SUPPORTED_PACKAGES, |
| ExplicitHealthCheckService.this.onGetSupportedPackages())); |
| } |
| |
| @Override |
| public void getRequestedPackages(RemoteCallback callback) throws RemoteException { |
| mHandler.post(() -> sendPackages(callback, EXTRA_REQUESTED_PACKAGES, |
| ExplicitHealthCheckService.this.onGetRequestedPackages())); |
| } |
| |
| private void sendPackages(RemoteCallback callback, String key, List<String> packages) { |
| Objects.requireNonNull(packages, |
| "Supported and requested package list must be non-null"); |
| Bundle bundle = new Bundle(); |
| bundle.putStringArrayList(key, new ArrayList<>(packages)); |
| callback.sendResult(bundle); |
| } |
| } |
| } |