RegisteredServicesCache.java revision 3fa51e3430e3bf902ae4f2d72dfb956103b6bd2d
1/* 2 * Copyright (C) 2009 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 17package android.content.pm; 18 19import android.content.Context; 20import android.content.BroadcastReceiver; 21import android.content.Intent; 22import android.content.IntentFilter; 23import android.content.ComponentName; 24import android.content.pm.PackageManager.NameNotFoundException; 25import android.content.res.Resources; 26import android.content.res.XmlResourceParser; 27import android.os.Environment; 28import android.os.Handler; 29import android.util.Log; 30import android.util.AttributeSet; 31import android.util.Xml; 32 33import java.util.Map; 34import java.util.Collection; 35import java.util.Collections; 36import java.util.HashMap; 37import java.util.List; 38import java.util.ArrayList; 39import java.util.concurrent.atomic.AtomicReference; 40import java.io.File; 41import java.io.FileOutputStream; 42import java.io.FileDescriptor; 43import java.io.PrintWriter; 44import java.io.IOException; 45import java.io.FileInputStream; 46 47import com.android.internal.os.AtomicFile; 48import com.android.internal.util.FastXmlSerializer; 49 50import com.google.android.collect.Maps; 51import com.google.android.collect.Lists; 52 53import org.xmlpull.v1.XmlPullParserException; 54import org.xmlpull.v1.XmlPullParser; 55import org.xmlpull.v1.XmlSerializer; 56 57/** 58 * A cache of registered services. This cache 59 * is built by interrogating the {@link PackageManager} and is updated as packages are added, 60 * removed and changed. The services are referred to by type V and 61 * are made available via the {@link #getServiceInfo} method. 62 * @hide 63 */ 64public abstract class RegisteredServicesCache<V> { 65 private static final String TAG = "PackageManager"; 66 67 public final Context mContext; 68 private final String mInterfaceName; 69 private final String mMetaDataName; 70 private final String mAttributesName; 71 private final XmlSerializerAndParser<V> mSerializerAndParser; 72 private final AtomicReference<BroadcastReceiver> mReceiver; 73 74 private final Object mServicesLock = new Object(); 75 // synchronized on mServicesLock 76 private HashMap<V, Integer> mPersistentServices; 77 // synchronized on mServicesLock 78 private Map<V, ServiceInfo<V>> mServices; 79 // synchronized on mServicesLock 80 private boolean mPersistentServicesFileDidNotExist; 81 82 /** 83 * This file contains the list of known services. We would like to maintain this forever 84 * so we store it as an XML file. 85 */ 86 private final AtomicFile mPersistentServicesFile; 87 88 // the listener and handler are synchronized on "this" and must be updated together 89 private RegisteredServicesCacheListener<V> mListener; 90 private Handler mHandler; 91 92 public RegisteredServicesCache(Context context, String interfaceName, String metaDataName, 93 String attributeName, XmlSerializerAndParser<V> serializerAndParser) { 94 mContext = context; 95 mInterfaceName = interfaceName; 96 mMetaDataName = metaDataName; 97 mAttributesName = attributeName; 98 mSerializerAndParser = serializerAndParser; 99 100 File dataDir = Environment.getDataDirectory(); 101 File systemDir = new File(dataDir, "system"); 102 File syncDir = new File(systemDir, "registered_services"); 103 mPersistentServicesFile = new AtomicFile(new File(syncDir, interfaceName + ".xml")); 104 105 generateServicesMap(); 106 107 final BroadcastReceiver receiver = new BroadcastReceiver() { 108 @Override 109 public void onReceive(Context context1, Intent intent) { 110 generateServicesMap(); 111 } 112 }; 113 mReceiver = new AtomicReference<BroadcastReceiver>(receiver); 114 IntentFilter intentFilter = new IntentFilter(); 115 intentFilter.addAction(Intent.ACTION_PACKAGE_ADDED); 116 intentFilter.addAction(Intent.ACTION_PACKAGE_CHANGED); 117 intentFilter.addAction(Intent.ACTION_PACKAGE_REMOVED); 118 intentFilter.addDataScheme("package"); 119 mContext.registerReceiver(receiver, intentFilter); 120 // Register for events related to sdcard installation. 121 IntentFilter sdFilter = new IntentFilter(); 122 sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE); 123 sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE); 124 mContext.registerReceiver(receiver, sdFilter); 125 } 126 127 public void dump(FileDescriptor fd, PrintWriter fout, String[] args) { 128 Map<V, ServiceInfo<V>> services; 129 synchronized (mServicesLock) { 130 services = mServices; 131 } 132 fout.println("RegisteredServicesCache: " + services.size() + " services"); 133 for (ServiceInfo info : services.values()) { 134 fout.println(" " + info); 135 } 136 } 137 138 public RegisteredServicesCacheListener<V> getListener() { 139 synchronized (this) { 140 return mListener; 141 } 142 } 143 144 public void setListener(RegisteredServicesCacheListener<V> listener, Handler handler) { 145 if (handler == null) { 146 handler = new Handler(mContext.getMainLooper()); 147 } 148 synchronized (this) { 149 mHandler = handler; 150 mListener = listener; 151 } 152 } 153 154 private void notifyListener(final V type, final boolean removed) { 155 if (Log.isLoggable(TAG, Log.VERBOSE)) { 156 Log.d(TAG, "notifyListener: " + type + " is " + (removed ? "removed" : "added")); 157 } 158 RegisteredServicesCacheListener<V> listener; 159 Handler handler; 160 synchronized (this) { 161 listener = mListener; 162 handler = mHandler; 163 } 164 if (listener == null) { 165 return; 166 } 167 168 final RegisteredServicesCacheListener<V> listener2 = listener; 169 handler.post(new Runnable() { 170 public void run() { 171 listener2.onServiceChanged(type, removed); 172 } 173 }); 174 } 175 176 /** 177 * Value type that describes a Service. The information within can be used 178 * to bind to the service. 179 */ 180 public static class ServiceInfo<V> { 181 public final V type; 182 public final ComponentName componentName; 183 public final int uid; 184 185 private ServiceInfo(V type, ComponentName componentName, int uid) { 186 this.type = type; 187 this.componentName = componentName; 188 this.uid = uid; 189 } 190 191 @Override 192 public String toString() { 193 return "ServiceInfo: " + type + ", " + componentName + ", uid " + uid; 194 } 195 } 196 197 /** 198 * Accessor for the registered authenticators. 199 * @param type the account type of the authenticator 200 * @return the AuthenticatorInfo that matches the account type or null if none is present 201 */ 202 public ServiceInfo<V> getServiceInfo(V type) { 203 synchronized (mServicesLock) { 204 return mServices.get(type); 205 } 206 } 207 208 /** 209 * @return a collection of {@link RegisteredServicesCache.ServiceInfo} objects for all 210 * registered authenticators. 211 */ 212 public Collection<ServiceInfo<V>> getAllServices() { 213 synchronized (mServicesLock) { 214 return Collections.unmodifiableCollection(mServices.values()); 215 } 216 } 217 218 /** 219 * Stops the monitoring of package additions, removals and changes. 220 */ 221 public void close() { 222 final BroadcastReceiver receiver = mReceiver.getAndSet(null); 223 if (receiver != null) { 224 mContext.unregisterReceiver(receiver); 225 } 226 } 227 228 @Override 229 protected void finalize() throws Throwable { 230 if (mReceiver.get() != null) { 231 Log.e(TAG, "RegisteredServicesCache finalized without being closed"); 232 } 233 close(); 234 super.finalize(); 235 } 236 237 private boolean inSystemImage(int callerUid) { 238 String[] packages = mContext.getPackageManager().getPackagesForUid(callerUid); 239 for (String name : packages) { 240 try { 241 PackageInfo packageInfo = 242 mContext.getPackageManager().getPackageInfo(name, 0 /* flags */); 243 if ((packageInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) { 244 return true; 245 } 246 } catch (PackageManager.NameNotFoundException e) { 247 return false; 248 } 249 } 250 return false; 251 } 252 253 void generateServicesMap() { 254 PackageManager pm = mContext.getPackageManager(); 255 ArrayList<ServiceInfo<V>> serviceInfos = new ArrayList<ServiceInfo<V>>(); 256 List<ResolveInfo> resolveInfos = pm.queryIntentServices(new Intent(mInterfaceName), 257 PackageManager.GET_META_DATA); 258 for (ResolveInfo resolveInfo : resolveInfos) { 259 try { 260 ServiceInfo<V> info = parseServiceInfo(resolveInfo); 261 if (info == null) { 262 Log.w(TAG, "Unable to load service info " + resolveInfo.toString()); 263 continue; 264 } 265 serviceInfos.add(info); 266 } catch (XmlPullParserException e) { 267 Log.w(TAG, "Unable to load service info " + resolveInfo.toString(), e); 268 } catch (IOException e) { 269 Log.w(TAG, "Unable to load service info " + resolveInfo.toString(), e); 270 } 271 } 272 273 synchronized (mServicesLock) { 274 if (mPersistentServices == null) { 275 readPersistentServicesLocked(); 276 } 277 mServices = Maps.newHashMap(); 278 StringBuilder changes = new StringBuilder(); 279 for (ServiceInfo<V> info : serviceInfos) { 280 // four cases: 281 // - doesn't exist yet 282 // - add, notify user that it was added 283 // - exists and the UID is the same 284 // - replace, don't notify user 285 // - exists, the UID is different, and the new one is not a system package 286 // - ignore 287 // - exists, the UID is different, and the new one is a system package 288 // - add, notify user that it was added 289 Integer previousUid = mPersistentServices.get(info.type); 290 if (previousUid == null) { 291 changes.append(" New service added: ").append(info).append("\n"); 292 mServices.put(info.type, info); 293 mPersistentServices.put(info.type, info.uid); 294 if (!mPersistentServicesFileDidNotExist) { 295 notifyListener(info.type, false /* removed */); 296 } 297 } else if (previousUid == info.uid) { 298 if (Log.isLoggable(TAG, Log.VERBOSE)) { 299 changes.append(" Existing service (nop): ").append(info).append("\n"); 300 } 301 mServices.put(info.type, info); 302 } else if (inSystemImage(info.uid) 303 || !containsTypeAndUid(serviceInfos, info.type, previousUid)) { 304 if (inSystemImage(info.uid)) { 305 changes.append(" System service replacing existing: ").append(info) 306 .append("\n"); 307 } else { 308 changes.append(" Existing service replacing a removed service: ") 309 .append(info).append("\n"); 310 } 311 mServices.put(info.type, info); 312 mPersistentServices.put(info.type, info.uid); 313 notifyListener(info.type, false /* removed */); 314 } else { 315 // ignore 316 changes.append(" Existing service with new uid ignored: ").append(info) 317 .append("\n"); 318 } 319 } 320 321 ArrayList<V> toBeRemoved = Lists.newArrayList(); 322 for (V v1 : mPersistentServices.keySet()) { 323 if (!containsType(serviceInfos, v1)) { 324 toBeRemoved.add(v1); 325 } 326 } 327 for (V v1 : toBeRemoved) { 328 mPersistentServices.remove(v1); 329 changes.append(" Service removed: ").append(v1).append("\n"); 330 notifyListener(v1, true /* removed */); 331 } 332 if (changes.length() > 0) { 333 Log.d(TAG, "generateServicesMap(" + mInterfaceName + "): " + 334 serviceInfos.size() + " services:\n" + changes); 335 writePersistentServicesLocked(); 336 } else { 337 Log.d(TAG, "generateServicesMap(" + mInterfaceName + "): " + 338 serviceInfos.size() + " services unchanged"); 339 } 340 mPersistentServicesFileDidNotExist = false; 341 } 342 } 343 344 private boolean containsType(ArrayList<ServiceInfo<V>> serviceInfos, V type) { 345 for (int i = 0, N = serviceInfos.size(); i < N; i++) { 346 if (serviceInfos.get(i).type.equals(type)) { 347 return true; 348 } 349 } 350 351 return false; 352 } 353 354 private boolean containsTypeAndUid(ArrayList<ServiceInfo<V>> serviceInfos, V type, int uid) { 355 for (int i = 0, N = serviceInfos.size(); i < N; i++) { 356 final ServiceInfo<V> serviceInfo = serviceInfos.get(i); 357 if (serviceInfo.type.equals(type) && serviceInfo.uid == uid) { 358 return true; 359 } 360 } 361 362 return false; 363 } 364 365 private ServiceInfo<V> parseServiceInfo(ResolveInfo service) 366 throws XmlPullParserException, IOException { 367 android.content.pm.ServiceInfo si = service.serviceInfo; 368 ComponentName componentName = new ComponentName(si.packageName, si.name); 369 370 PackageManager pm = mContext.getPackageManager(); 371 372 XmlResourceParser parser = null; 373 try { 374 parser = si.loadXmlMetaData(pm, mMetaDataName); 375 if (parser == null) { 376 throw new XmlPullParserException("No " + mMetaDataName + " meta-data"); 377 } 378 379 AttributeSet attrs = Xml.asAttributeSet(parser); 380 381 int type; 382 while ((type=parser.next()) != XmlPullParser.END_DOCUMENT 383 && type != XmlPullParser.START_TAG) { 384 } 385 386 String nodeName = parser.getName(); 387 if (!mAttributesName.equals(nodeName)) { 388 throw new XmlPullParserException( 389 "Meta-data does not start with " + mAttributesName + " tag"); 390 } 391 392 V v = parseServiceAttributes(pm.getResourcesForApplication(si.applicationInfo), 393 si.packageName, attrs); 394 if (v == null) { 395 return null; 396 } 397 final android.content.pm.ServiceInfo serviceInfo = service.serviceInfo; 398 final ApplicationInfo applicationInfo = serviceInfo.applicationInfo; 399 final int uid = applicationInfo.uid; 400 return new ServiceInfo<V>(v, componentName, uid); 401 } catch (NameNotFoundException e) { 402 throw new XmlPullParserException( 403 "Unable to load resources for pacakge " + si.packageName); 404 } finally { 405 if (parser != null) parser.close(); 406 } 407 } 408 409 /** 410 * Read all sync status back in to the initial engine state. 411 */ 412 private void readPersistentServicesLocked() { 413 mPersistentServices = Maps.newHashMap(); 414 if (mSerializerAndParser == null) { 415 return; 416 } 417 FileInputStream fis = null; 418 try { 419 mPersistentServicesFileDidNotExist = !mPersistentServicesFile.getBaseFile().exists(); 420 if (mPersistentServicesFileDidNotExist) { 421 return; 422 } 423 fis = mPersistentServicesFile.openRead(); 424 XmlPullParser parser = Xml.newPullParser(); 425 parser.setInput(fis, null); 426 int eventType = parser.getEventType(); 427 while (eventType != XmlPullParser.START_TAG) { 428 eventType = parser.next(); 429 } 430 String tagName = parser.getName(); 431 if ("services".equals(tagName)) { 432 eventType = parser.next(); 433 do { 434 if (eventType == XmlPullParser.START_TAG && parser.getDepth() == 2) { 435 tagName = parser.getName(); 436 if ("service".equals(tagName)) { 437 V service = mSerializerAndParser.createFromXml(parser); 438 if (service == null) { 439 break; 440 } 441 String uidString = parser.getAttributeValue(null, "uid"); 442 int uid = Integer.parseInt(uidString); 443 mPersistentServices.put(service, uid); 444 } 445 } 446 eventType = parser.next(); 447 } while (eventType != XmlPullParser.END_DOCUMENT); 448 } 449 } catch (Exception e) { 450 Log.w(TAG, "Error reading persistent services, starting from scratch", e); 451 } finally { 452 if (fis != null) { 453 try { 454 fis.close(); 455 } catch (java.io.IOException e1) { 456 } 457 } 458 } 459 } 460 461 /** 462 * Write all sync status to the sync status file. 463 */ 464 private void writePersistentServicesLocked() { 465 if (mSerializerAndParser == null) { 466 return; 467 } 468 FileOutputStream fos = null; 469 try { 470 fos = mPersistentServicesFile.startWrite(); 471 XmlSerializer out = new FastXmlSerializer(); 472 out.setOutput(fos, "utf-8"); 473 out.startDocument(null, true); 474 out.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true); 475 out.startTag(null, "services"); 476 for (Map.Entry<V, Integer> service : mPersistentServices.entrySet()) { 477 out.startTag(null, "service"); 478 out.attribute(null, "uid", Integer.toString(service.getValue())); 479 mSerializerAndParser.writeAsXml(service.getKey(), out); 480 out.endTag(null, "service"); 481 } 482 out.endTag(null, "services"); 483 out.endDocument(); 484 mPersistentServicesFile.finishWrite(fos); 485 } catch (java.io.IOException e1) { 486 Log.w(TAG, "Error writing accounts", e1); 487 if (fos != null) { 488 mPersistentServicesFile.failWrite(fos); 489 } 490 } 491 } 492 493 public abstract V parseServiceAttributes(Resources res, 494 String packageName, AttributeSet attrs); 495} 496