Zimuzo | 0de99f3 | 2019-03-18 13:23:55 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2019 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.server; |
| 18 | import static android.service.watchdog.ExplicitHealthCheckService.EXTRA_HEALTH_CHECK_PASSED_PACKAGE; |
| 19 | import static android.service.watchdog.ExplicitHealthCheckService.EXTRA_REQUESTED_PACKAGES; |
| 20 | import static android.service.watchdog.ExplicitHealthCheckService.EXTRA_SUPPORTED_PACKAGES; |
| 21 | |
| 22 | import android.Manifest; |
| 23 | import android.annotation.MainThread; |
| 24 | import android.annotation.Nullable; |
| 25 | import android.content.ComponentName; |
| 26 | import android.content.Context; |
| 27 | import android.content.Intent; |
| 28 | import android.content.ServiceConnection; |
| 29 | import android.content.pm.PackageManager; |
| 30 | import android.content.pm.ResolveInfo; |
| 31 | import android.content.pm.ServiceInfo; |
| 32 | import android.os.IBinder; |
| 33 | import android.os.RemoteCallback; |
| 34 | import android.os.RemoteException; |
| 35 | import android.os.UserHandle; |
| 36 | import android.service.watchdog.ExplicitHealthCheckService; |
| 37 | import android.service.watchdog.IExplicitHealthCheckService; |
| 38 | import android.text.TextUtils; |
| 39 | import android.util.Slog; |
| 40 | |
| 41 | import com.android.internal.annotations.GuardedBy; |
| 42 | |
| 43 | import java.util.List; |
| 44 | import java.util.function.Consumer; |
| 45 | |
| 46 | /** |
| 47 | * Controls the connections with {@link ExplicitHealthCheckService}. |
| 48 | */ |
| 49 | class ExplicitHealthCheckController { |
| 50 | private static final String TAG = "ExplicitHealthCheckController"; |
| 51 | private final Object mLock = new Object(); |
| 52 | private final Context mContext; |
| 53 | @GuardedBy("mLock") @Nullable private StateCallback mStateCallback; |
| 54 | @GuardedBy("mLock") @Nullable private IExplicitHealthCheckService mRemoteService; |
| 55 | @GuardedBy("mLock") @Nullable private ServiceConnection mConnection; |
| 56 | @GuardedBy("mLock") @Nullable private List<String> mSupportedPackages; |
| 57 | |
| 58 | ExplicitHealthCheckController(Context context) { |
| 59 | mContext = context; |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Requests an explicit health check for {@code packageName}. |
| 64 | * After this request, the callback registered on {@link startService} can receive explicit |
| 65 | * health check passed results. |
| 66 | * |
| 67 | * @throws IllegalStateException if the service is not started |
| 68 | */ |
| 69 | public void request(String packageName) throws RemoteException { |
| 70 | synchronized (mLock) { |
| 71 | enforceServiceReadyLocked(); |
| 72 | mRemoteService.request(packageName); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Cancels all explicit health checks for {@code packageName}. |
| 78 | * After this request, the callback registered on {@link startService} can no longer receive |
| 79 | * explicit health check passed results. |
| 80 | * |
| 81 | * @throws IllegalStateException if the service is not started |
| 82 | */ |
| 83 | public void cancel(String packageName) throws RemoteException { |
| 84 | synchronized (mLock) { |
| 85 | enforceServiceReadyLocked(); |
| 86 | mRemoteService.cancel(packageName); |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Returns the packages that we can request explicit health checks for. |
| 92 | * The packages will be returned to the {@code consumer}. |
| 93 | * |
| 94 | * @throws IllegalStateException if the service is not started |
| 95 | */ |
| 96 | public void getSupportedPackages(Consumer<List<String>> consumer) throws RemoteException { |
| 97 | synchronized (mLock) { |
| 98 | enforceServiceReadyLocked(); |
| 99 | if (mSupportedPackages == null) { |
| 100 | mRemoteService.getSupportedPackages(new RemoteCallback(result -> { |
| 101 | mSupportedPackages = result.getStringArrayList(EXTRA_SUPPORTED_PACKAGES); |
| 102 | consumer.accept(mSupportedPackages); |
| 103 | })); |
| 104 | } else { |
| 105 | consumer.accept(mSupportedPackages); |
| 106 | } |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Returns the packages for which health checks are currently in progress. |
| 112 | * The packages will be returned to the {@code consumer}. |
| 113 | * |
| 114 | * @throws IllegalStateException if the service is not started |
| 115 | */ |
| 116 | public void getRequestedPackages(Consumer<List<String>> consumer) throws RemoteException { |
| 117 | synchronized (mLock) { |
| 118 | enforceServiceReadyLocked(); |
| 119 | mRemoteService.getRequestedPackages(new RemoteCallback( |
| 120 | result -> consumer.accept( |
| 121 | result.getStringArrayList(EXTRA_REQUESTED_PACKAGES)))); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Starts the explicit health check service. |
| 127 | * |
| 128 | * @param stateCallback will receive important state changes changes |
| 129 | * @param passedConsumer will accept packages that pass explicit health checks |
| 130 | * |
| 131 | * @throws IllegalStateException if the service is already started |
| 132 | */ |
| 133 | public void startService(StateCallback stateCallback, Consumer<String> passedConsumer) { |
| 134 | synchronized (mLock) { |
| 135 | if (mRemoteService != null) { |
| 136 | throw new IllegalStateException("Explicit health check service already started."); |
| 137 | } |
| 138 | mStateCallback = stateCallback; |
| 139 | mConnection = new ServiceConnection() { |
| 140 | @Override |
| 141 | public void onServiceConnected(ComponentName name, IBinder service) { |
| 142 | synchronized (mLock) { |
| 143 | mRemoteService = IExplicitHealthCheckService.Stub.asInterface(service); |
| 144 | try { |
| 145 | mRemoteService.setCallback(new RemoteCallback(result -> { |
| 146 | String packageName = |
| 147 | result.getString(EXTRA_HEALTH_CHECK_PASSED_PACKAGE); |
| 148 | if (!TextUtils.isEmpty(packageName)) { |
| 149 | passedConsumer.accept(packageName); |
| 150 | } else { |
| 151 | Slog.w(TAG, "Empty package passed explicit health check?"); |
| 152 | } |
| 153 | })); |
| 154 | mStateCallback.onStart(); |
| 155 | Slog.i(TAG, "Explicit health check service is connected " + name); |
| 156 | } catch (RemoteException e) { |
| 157 | Slog.wtf(TAG, "Coud not setCallback on explicit health check service"); |
| 158 | } |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | @Override |
| 163 | @MainThread |
| 164 | public void onServiceDisconnected(ComponentName name) { |
| 165 | resetState(); |
| 166 | Slog.i(TAG, "Explicit health check service is disconnected " + name); |
| 167 | } |
| 168 | |
| 169 | @Override |
| 170 | public void onBindingDied(ComponentName name) { |
| 171 | resetState(); |
| 172 | Slog.i(TAG, "Explicit health check service binding is dead " + name); |
| 173 | } |
| 174 | |
| 175 | @Override |
| 176 | public void onNullBinding(ComponentName name) { |
| 177 | resetState(); |
| 178 | Slog.i(TAG, "Explicit health check service binding is null " + name); |
| 179 | } |
| 180 | }; |
| 181 | |
| 182 | ComponentName component = getServiceComponentNameLocked(); |
| 183 | if (component != null) { |
| 184 | Intent intent = new Intent(); |
| 185 | intent.setComponent(component); |
| 186 | mContext.bindServiceAsUser(intent, mConnection, Context.BIND_AUTO_CREATE, |
| 187 | UserHandle.of(UserHandle.USER_SYSTEM)); |
| 188 | } |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | // TODO: Differentiate between expected vs unexpected stop? |
| 193 | /** Callback to receive important {@link ExplicitHealthCheckController} state changes. */ |
| 194 | abstract static class StateCallback { |
| 195 | /** The controller is ready and we can request explicit health checks for packages */ |
| 196 | public void onStart() {} |
| 197 | |
| 198 | /** The controller is not ready and we cannot request explicit health checks for packages */ |
| 199 | public void onStop() {} |
| 200 | } |
| 201 | |
| 202 | /** Stops the explicit health check service. */ |
| 203 | public void stopService() { |
| 204 | synchronized (mLock) { |
| 205 | if (mRemoteService != null) { |
| 206 | mContext.unbindService(mConnection); |
| 207 | } |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | @GuardedBy("mLock") |
| 212 | @Nullable |
| 213 | private ServiceInfo getServiceInfoLocked() { |
| 214 | final String packageName = |
| 215 | mContext.getPackageManager().getServicesSystemSharedLibraryPackageName(); |
| 216 | if (packageName == null) { |
| 217 | Slog.w(TAG, "no external services package!"); |
| 218 | return null; |
| 219 | } |
| 220 | |
| 221 | final Intent intent = new Intent(ExplicitHealthCheckService.SERVICE_INTERFACE); |
| 222 | intent.setPackage(packageName); |
| 223 | final ResolveInfo resolveInfo = mContext.getPackageManager().resolveService(intent, |
| 224 | PackageManager.GET_SERVICES | PackageManager.GET_META_DATA); |
| 225 | if (resolveInfo == null || resolveInfo.serviceInfo == null) { |
| 226 | Slog.w(TAG, "No valid components found."); |
| 227 | return null; |
| 228 | } |
| 229 | return resolveInfo.serviceInfo; |
| 230 | } |
| 231 | |
| 232 | @GuardedBy("mLock") |
| 233 | @Nullable |
| 234 | private ComponentName getServiceComponentNameLocked() { |
| 235 | final ServiceInfo serviceInfo = getServiceInfoLocked(); |
| 236 | if (serviceInfo == null) { |
| 237 | return null; |
| 238 | } |
| 239 | |
| 240 | final ComponentName name = new ComponentName(serviceInfo.packageName, serviceInfo.name); |
| 241 | if (!Manifest.permission.BIND_EXPLICIT_HEALTH_CHECK_SERVICE |
| 242 | .equals(serviceInfo.permission)) { |
| 243 | Slog.w(TAG, name.flattenToShortString() + " does not require permission " |
| 244 | + Manifest.permission.BIND_EXPLICIT_HEALTH_CHECK_SERVICE); |
| 245 | return null; |
| 246 | } |
| 247 | return name; |
| 248 | } |
| 249 | |
| 250 | private void resetState() { |
| 251 | synchronized (mLock) { |
| 252 | mStateCallback.onStop(); |
| 253 | mStateCallback = null; |
| 254 | mSupportedPackages = null; |
| 255 | mRemoteService = null; |
| 256 | mConnection = null; |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | @GuardedBy("mLock") |
| 261 | private void enforceServiceReadyLocked() { |
| 262 | if (mRemoteService == null) { |
| 263 | throw new IllegalStateException("Explicit health check service not ready"); |
| 264 | } |
| 265 | } |
| 266 | } |