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/*
* Copyright (C) 2009 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.app.backup;
import android.annotation.IntDef;
import android.annotation.Nullable;
import android.app.IBackupAgent;
import android.app.QueuedWork;
import android.app.backup.BackupManager.OperationType;
import android.app.backup.FullBackup.BackupScheme.PathWithRequiredFlags;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.pm.ApplicationInfo;
import android.os.Binder;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.os.RemoteException;
import android.os.UserHandle;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.system.StructStat;
import android.util.ArraySet;
import android.util.Log;
import com.android.internal.annotations.VisibleForTesting;
import libcore.io.IoUtils;
import org.xmlpull.v1.XmlPullParserException;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
/**
* Provides the central interface between an
* application and Android's data backup infrastructure. An application that wishes
* to participate in the backup and restore mechanism will declare a subclass of
* {@link android.app.backup.BackupAgent}, implement the
* {@link #onBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor) onBackup()}
* and {@link #onRestore(BackupDataInput, int, ParcelFileDescriptor) onRestore()} methods,
* and provide the name of its backup agent class in its {@code AndroidManifest.xml} file via
* the
* <application>
* tag's {@code android:backupAgent} attribute.
*
*
* Developer Guides
* For more information about using BackupAgent, read the
* Data Backup developer guide.
*
* Basic Operation
*
* When the application makes changes to data that it wishes to keep backed up,
* it should call the
* {@link android.app.backup.BackupManager#dataChanged() BackupManager.dataChanged()} method.
* This notifies the Android Backup Manager that the application needs an opportunity
* to update its backup image. The Backup Manager, in turn, schedules a
* backup pass to be performed at an opportune time.
*
* Restore operations are typically performed only when applications are first
* installed on a device. At that time, the operating system checks to see whether
* there is a previously-saved data set available for the application being installed, and if so,
* begins an immediate restore pass to deliver the backup data as part of the installation
* process.
*
* When a backup or restore pass is run, the application's process is launched
* (if not already running), the manifest-declared backup agent class (in the {@code
* android:backupAgent} attribute) is instantiated within
* that process, and the agent's {@link #onCreate()} method is invoked. This prepares the
* agent instance to run the actual backup or restore logic. At this point the
* agent's
* {@link #onBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor) onBackup()} or
* {@link #onRestore(BackupDataInput, int, ParcelFileDescriptor) onRestore()} method will be
* invoked as appropriate for the operation being performed.
*
* A backup data set consists of one or more "entities," flattened binary data
* records that are each identified with a key string unique within the data set. Adding a
* record to the active data set or updating an existing record is done by simply
* writing new entity data under the desired key. Deleting an entity from the data set
* is done by writing an entity under that key with header specifying a negative data
* size, and no actual entity data.
*
* Helper Classes
*
* An extensible agent based on convenient helper classes is available in
* {@link android.app.backup.BackupAgentHelper}. That class is particularly
* suited to handling of simple file or {@link android.content.SharedPreferences}
* backup and restore.
*
* Threading
*
* The constructor, as well as {@link #onCreate()} and {@link #onDestroy()} lifecycle callbacks run
* on the main thread (UI thread) of the application that implements the BackupAgent.
* The data-handling callbacks:
* {@link #onBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor) onBackup()},
* {@link #onFullBackup(FullBackupDataOutput)},
* {@link #onRestore(BackupDataInput, int, ParcelFileDescriptor) onRestore()},
* {@link #onRestoreFile(ParcelFileDescriptor, long, File, int, long, long) onRestoreFile()},
* {@link #onRestoreFinished()}, and {@link #onQuotaExceeded(long, long) onQuotaExceeded()}
* run on binder pool threads.
*
* @see android.app.backup.BackupManager
* @see android.app.backup.BackupAgentHelper
* @see android.app.backup.BackupDataInput
* @see android.app.backup.BackupDataOutput
*/
public abstract class BackupAgent extends ContextWrapper {
private static final String TAG = "BackupAgent";
private static final boolean DEBUG = false;
private static final int DEFAULT_OPERATION_TYPE = OperationType.BACKUP;
/** @hide */
public static final int RESULT_SUCCESS = 0;
/** @hide */
public static final int RESULT_ERROR = -1;
/** @hide */
public static final int TYPE_EOF = 0;
/**
* During a full restore, indicates that the file system object being restored
* is an ordinary file.
*/
public static final int TYPE_FILE = 1;
/**
* During a full restore, indicates that the file system object being restored
* is a directory.
*/
public static final int TYPE_DIRECTORY = 2;
/** @hide */
public static final int TYPE_SYMLINK = 3;
/**
* Flag for {@link BackupDataOutput#getTransportFlags()} and
* {@link FullBackupDataOutput#getTransportFlags()} only.
*
*
The transport has client-side encryption enabled. i.e., the user's backup has been
* encrypted with a key known only to the device, and not to the remote storage solution. Even
* if an attacker had root access to the remote storage provider they should not be able to
* decrypt the user's backup data.
*/
public static final int FLAG_CLIENT_SIDE_ENCRYPTION_ENABLED = 1;
/**
* Flag for {@link BackupDataOutput#getTransportFlags()} and
* {@link FullBackupDataOutput#getTransportFlags()} only.
*
*
The transport is for a device-to-device transfer. There is no third party or intermediate
* storage. The user's backup data is sent directly to another device over e.g., USB or WiFi.
*/
public static final int FLAG_DEVICE_TO_DEVICE_TRANSFER = 2;
/**
* Flag for {@link BackupDataOutput#getTransportFlags()} and
* {@link FullBackupDataOutput#getTransportFlags()} only.
*
*
Used for internal testing only. Do not check this flag in production code.
*
* @hide
*/
public static final int FLAG_FAKE_CLIENT_SIDE_ENCRYPTION_ENABLED = 1 << 31;
/** @hide */
@Retention(RetentionPolicy.SOURCE)
@IntDef(flag = true, value = {
FLAG_CLIENT_SIDE_ENCRYPTION_ENABLED,
FLAG_DEVICE_TO_DEVICE_TRANSFER,
FLAG_FAKE_CLIENT_SIDE_ENCRYPTION_ENABLED
})
public @interface BackupTransportFlags {}
Handler mHandler = null;
@Nullable private UserHandle mUser;
// This field is written from the main thread (in onCreate), and read in a Binder thread (in
// onFullBackup that is called from system_server via Binder).
@OperationType private volatile int mOperationType = DEFAULT_OPERATION_TYPE;
Handler getHandler() {
if (mHandler == null) {
mHandler = new Handler(Looper.getMainLooper());
}
return mHandler;
}
class SharedPrefsSynchronizer implements Runnable {
public final CountDownLatch mLatch = new CountDownLatch(1);
@Override
public void run() {
QueuedWork.waitToFinish();
mLatch.countDown();
}
};
// Syncing shared preferences deferred writes needs to happen on the main looper thread
private void waitForSharedPrefs() {
Handler h = getHandler();
final SharedPrefsSynchronizer s = new SharedPrefsSynchronizer();
h.postAtFrontOfQueue(s);
try {
s.mLatch.await();
} catch (InterruptedException e) { /* ignored */ }
}
public BackupAgent() {
super(null);
}
/**
* Provided as a convenience for agent implementations that need an opportunity
* to do one-time initialization before the actual backup or restore operation
* is begun.
*
*/
public void onCreate() {
}
/**
* @hide
*/
public void onCreate(UserHandle user) {
onCreate(user, DEFAULT_OPERATION_TYPE);
}
/**
* Provided as a convenience for agent implementations that need an opportunity
* to do one-time initialization before the actual backup or restore operation
* is begun with information about the calling user.
*
*
* @hide
*/
public void onCreate(UserHandle user, @OperationType int operationType) {
onCreate();
mUser = user;
mOperationType = operationType;
}
/**
* Provided as a convenience for agent implementations that need to do some
* sort of shutdown process after backup or restore is completed.
*
* Agents do not need to override this method.
*/
public void onDestroy() {
}
/**
* The application is being asked to write any data changed since the last
* time it performed a backup operation. The state data recorded during the
* last backup pass is provided in the oldState file
* descriptor. If oldState is null, no old state
* is available and the application should perform a full backup. In both
* cases, a representation of the final backup state after this pass should
* be written to the file pointed to by the file descriptor wrapped in
* newState.
*
* Each entity written to the {@link android.app.backup.BackupDataOutput}
* data stream will be transmitted
* over the current backup transport and stored in the remote data set under
* the key supplied as part of the entity. Writing an entity with a negative
* data size instructs the transport to delete whatever entity currently exists
* under that key from the remote data set.
*
* @param oldState An open, read-only ParcelFileDescriptor pointing to the
* last backup state provided by the application. May be
* null, in which case no prior state is being
* provided and the application should perform a full backup.
* @param data A structured wrapper around an open, read/write
* file descriptor pointing to the backup data destination.
* Typically the application will use backup helper classes to
* write to this file.
* @param newState An open, read/write ParcelFileDescriptor pointing to an
* empty file. The application should record the final backup
* state here after writing the requested data to the data
* output stream.
*/
public abstract void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data,
ParcelFileDescriptor newState) throws IOException;
/**
* The application is being restored from backup and should replace any
* existing data with the contents of the backup. The backup data is
* provided through the data parameter. Once
* the restore is finished, the application should write a representation of
* the final state to the newState file descriptor.
*
* The application is responsible for properly erasing its old data and
* replacing it with the data supplied to this method. No "clear user data"
* operation will be performed automatically by the operating system. The
* exception to this is in the case of a failed restore attempt: if
* onRestore() throws an exception, the OS will assume that the
* application's data may now be in an incoherent state, and will clear it
* before proceeding.
*
* @param data A structured wrapper around an open, read-only
* file descriptor pointing to a full snapshot of the
* application's data. The application should consume every
* entity represented in this data stream.
* @param appVersionCode The value of the {@code
* android:versionCode} manifest attribute,
* from the application that backed up this particular data set. This
* makes it possible for an application's agent to distinguish among any
* possible older data versions when asked to perform the restore
* operation.
* @param newState An open, read/write ParcelFileDescriptor pointing to an
* empty file. The application should record the final backup
* state here after restoring its data from the data stream.
* When a full-backup dataset is being restored, this will be null.
*/
public abstract void onRestore(BackupDataInput data, int appVersionCode,
ParcelFileDescriptor newState) throws IOException;
/**
* New version of {@link #onRestore(BackupDataInput, int, android.os.ParcelFileDescriptor)}
* that handles a long app version code. Default implementation casts the version code to
* an int and calls {@link #onRestore(BackupDataInput, int, android.os.ParcelFileDescriptor)}.
*/
public void onRestore(BackupDataInput data, long appVersionCode,
ParcelFileDescriptor newState)
throws IOException {
onRestore(data, (int) appVersionCode, newState);
}
/**
* New version of {@link #onRestore(BackupDataInput, long, android.os.ParcelFileDescriptor)}
* that has a list of keys to be excluded from the restore. Key/value pairs for which the key
* is present in {@code excludedKeys} have already been excluded from the restore data by the
* system. The list is passed to the agent to make it aware of what data has been removed (in
* case it has any application-level consequences) as well as the data that should be removed
* by the agent itself.
*
* The default implementation calls {@link #onRestore(BackupDataInput, long,
* android.os.ParcelFileDescriptor)}.
*
* @param excludedKeys A list of keys to be excluded from restore.
*
* @hide
*/
public void onRestore(BackupDataInput data, long appVersionCode,
ParcelFileDescriptor newState,
Set excludedKeys)
throws IOException {
onRestore(data, appVersionCode, newState);
}
/**
* The application is having its entire file system contents backed up. {@code data}
* points to the backup destination, and the app has the opportunity to choose which
* files are to be stored. To commit a file as part of the backup, call the
* {@link #fullBackupFile(File, FullBackupDataOutput)} helper method. After all file
* data is written to the output, the agent returns from this method and the backup
* operation concludes.
*
* Certain parts of the app's data are never backed up even if the app explicitly
* sends them to the output:
*
*
* - The contents of the {@link #getCacheDir()} directory
* - The contents of the {@link #getCodeCacheDir()} directory
* - The contents of the {@link #getNoBackupFilesDir()} directory
* - The contents of the app's shared library directory
*
*
* The default implementation of this method backs up the entirety of the
* application's "owned" file system trees to the output other than the few exceptions
* listed above. Apps only need to override this method if they need to impose special
* limitations on which files are being stored beyond the control that
* {@link #getNoBackupFilesDir()} offers.
* Alternatively they can provide an xml resource to specify what data to include or exclude.
*
*
* @param data A structured wrapper pointing to the backup destination.
* @throws IOException
*
* @see Context#getNoBackupFilesDir()
* @see #fullBackupFile(File, FullBackupDataOutput)
* @see #onRestoreFile(ParcelFileDescriptor, long, File, int, long, long)
*/
public void onFullBackup(FullBackupDataOutput data) throws IOException {
FullBackup.BackupScheme backupScheme = FullBackup.getBackupScheme(this,
mOperationType);
if (!backupScheme.isFullBackupEnabled(data.getTransportFlags())) {
return;
}
IncludeExcludeRules includeExcludeRules;
try {
includeExcludeRules = getIncludeExcludeRules(backupScheme);
} catch (IOException | XmlPullParserException e) {
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER,
"Exception trying to parse fullBackupContent xml file!"
+ " Aborting full backup.", e);
}
return;
}
Map> manifestIncludeMap
= includeExcludeRules.getIncludeMap();
Set manifestExcludeSet
= includeExcludeRules.getExcludeSet();
final String packageName = getPackageName();
final ApplicationInfo appInfo = getApplicationInfo();
// System apps have control over where their default storage context
// is pointed, so we're always explicit when building paths.
final Context ceContext = createCredentialProtectedStorageContext();
final String rootDir = ceContext.getDataDir().getCanonicalPath();
final String filesDir = ceContext.getFilesDir().getCanonicalPath();
final String databaseDir = ceContext.getDatabasePath("foo").getParentFile()
.getCanonicalPath();
final String sharedPrefsDir = ceContext.getSharedPreferencesPath("foo").getParentFile()
.getCanonicalPath();
final Context deContext = createDeviceProtectedStorageContext();
final String deviceRootDir = deContext.getDataDir().getCanonicalPath();
final String deviceFilesDir = deContext.getFilesDir().getCanonicalPath();
final String deviceDatabaseDir = deContext.getDatabasePath("foo").getParentFile()
.getCanonicalPath();
final String deviceSharedPrefsDir = deContext.getSharedPreferencesPath("foo")
.getParentFile().getCanonicalPath();
final String libDir = (appInfo.nativeLibraryDir != null)
? new File(appInfo.nativeLibraryDir).getCanonicalPath()
: null;
// Maintain a set of excluded directories so that as we traverse the tree we know we're not
// going places we don't expect, and so the manifest includes can't take precedence over
// what the framework decides is not to be included.
final ArraySet traversalExcludeSet = new ArraySet();
// Add the directories we always exclude.
traversalExcludeSet.add(filesDir);
traversalExcludeSet.add(databaseDir);
traversalExcludeSet.add(sharedPrefsDir);
traversalExcludeSet.add(deviceFilesDir);
traversalExcludeSet.add(deviceDatabaseDir);
traversalExcludeSet.add(deviceSharedPrefsDir);
if (libDir != null) {
traversalExcludeSet.add(libDir);
}
Set extraExcludedDirs = getExtraExcludeDirsIfAny(ceContext);
Set extraExcludedDeviceDirs = getExtraExcludeDirsIfAny(deContext);
traversalExcludeSet.addAll(extraExcludedDirs);
traversalExcludeSet.addAll(extraExcludedDeviceDirs);
// Root dir first.
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.ROOT_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(rootDir);
// Exclude the extra directories anyway, since we've already covered them if it was needed.
traversalExcludeSet.addAll(extraExcludedDirs);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.DEVICE_ROOT_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(deviceRootDir);
// Exclude the extra directories anyway, since we've already covered them if it was needed.
traversalExcludeSet.addAll(extraExcludedDeviceDirs);
// Data dir next.
traversalExcludeSet.remove(filesDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.FILES_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(filesDir);
traversalExcludeSet.remove(deviceFilesDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.DEVICE_FILES_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(deviceFilesDir);
// Database directory.
traversalExcludeSet.remove(databaseDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.DATABASE_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(databaseDir);
traversalExcludeSet.remove(deviceDatabaseDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.DEVICE_DATABASE_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(deviceDatabaseDir);
// SharedPrefs.
traversalExcludeSet.remove(sharedPrefsDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.SHAREDPREFS_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(sharedPrefsDir);
traversalExcludeSet.remove(deviceSharedPrefsDir);
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.DEVICE_SHAREDPREFS_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
traversalExcludeSet.add(deviceSharedPrefsDir);
// getExternalFilesDir() location associated with this app. Technically there should
// not be any files here if the app does not properly have permission to access
// external storage, but edge cases happen. fullBackupFileTree() catches
// IOExceptions and similar, and treats them as non-fatal, so we rely on that; and
// we know a priori that processes running as the system UID are not permitted to
// access external storage, so we check for that as well to avoid nastygrams in
// the log.
if (Process.myUid() != Process.SYSTEM_UID) {
File efLocation = getExternalFilesDir(null);
if (efLocation != null) {
applyXmlFiltersAndDoFullBackupForDomain(
packageName, FullBackup.MANAGED_EXTERNAL_TREE_TOKEN, manifestIncludeMap,
manifestExcludeSet, traversalExcludeSet, data);
}
}
}
private Set getExtraExcludeDirsIfAny(Context context) throws IOException {
Set excludedDirs = new HashSet<>();
excludedDirs.add(context.getCacheDir().getCanonicalPath());
excludedDirs.add(context.getCodeCacheDir().getCanonicalPath());
excludedDirs.add(context.getNoBackupFilesDir().getCanonicalPath());
return Collections.unmodifiableSet(excludedDirs);
}
/** @hide */
@VisibleForTesting
public IncludeExcludeRules getIncludeExcludeRules(FullBackup.BackupScheme backupScheme)
throws IOException, XmlPullParserException {
Map> manifestIncludeMap;
ArraySet manifestExcludeSet;
manifestIncludeMap =
backupScheme.maybeParseAndGetCanonicalIncludePaths();
manifestExcludeSet = backupScheme.maybeParseAndGetCanonicalExcludePaths();
return new IncludeExcludeRules(manifestIncludeMap, manifestExcludeSet);
}
/**
* Notification that the application's current backup operation causes it to exceed
* the maximum size permitted by the transport. The ongoing backup operation is
* halted and rolled back: any data that had been stored by a previous backup operation
* is still intact. Typically the quota-exceeded state will be detected before any data
* is actually transmitted over the network.
*
* The {@code quotaBytes} value is the total data size currently permitted for this
* application. If desired, the application can use this as a hint for determining
* how much data to store. For example, a messaging application might choose to
* store only the newest messages, dropping enough older content to stay under
* the quota.
*
*
Note that the maximum quota for the application can change over
* time. In particular, in the future the quota may grow. Applications that adapt
* to the quota when deciding what data to store should be aware of this and implement
* their data storage mechanisms in a way that can take advantage of additional
* quota.
*
* @param backupDataBytes The amount of data measured while initializing the backup
* operation, if the total exceeds the app's alloted quota. If initial measurement
* suggested that the data would fit but then too much data was actually submitted
* as part of the operation, then this value is the amount of data that had been
* streamed into the transport at the time the quota was reached.
* @param quotaBytes The maximum data size that the transport currently permits
* this application to store as a backup.
*/
public void onQuotaExceeded(long backupDataBytes, long quotaBytes) {
}
private int getBackupUserId() {
return mUser == null ? super.getUserId() : mUser.getIdentifier();
}
/**
* Check whether the xml yielded any domainToken.
* If so, perform a {@link #fullBackupFileTree} which backs up the file or recurses if the path
* is a directory, but only if all the required flags of the include rule are satisfied by
* the transport.
*/
private void applyXmlFiltersAndDoFullBackupForDomain(String packageName, String domainToken,
Map> includeMap,
Set filterSet, ArraySet traversalExcludeSet,
FullBackupDataOutput data) throws IOException {
if (includeMap == null || includeMap.size() == 0) {
// Do entire sub-tree for the provided token.
fullBackupFileTree(packageName, domainToken,
FullBackup.getBackupScheme(this, mOperationType)
.tokenToDirectoryPath(domainToken),
filterSet, traversalExcludeSet, data);
} else if (includeMap.get(domainToken) != null) {
// This will be null if the xml parsing didn't yield any rules for
// this domain (there may still be rules for other domains).
for (PathWithRequiredFlags includeFile : includeMap.get(domainToken)) {
if (areIncludeRequiredTransportFlagsSatisfied(includeFile.getRequiredFlags(),
data.getTransportFlags())) {
fullBackupFileTree(packageName, domainToken, includeFile.getPath(), filterSet,
traversalExcludeSet, data);
}
}
}
}
private boolean areIncludeRequiredTransportFlagsSatisfied(int includeFlags,
int transportFlags) {
// all bits that are set in includeFlags must also be set in transportFlags
return (transportFlags & includeFlags) == includeFlags;
}
/**
* Write an entire file as part of a full-backup operation. The file's contents
* will be delivered to the backup destination along with the metadata necessary
* to place it with the proper location and permissions on the device where the
* data is restored.
*
* Attempting to back up files in directories that are ignored by
* the backup system will have no effect. For example, if the app calls this method
* with a file inside the {@link #getNoBackupFilesDir()} directory, it will be ignored.
* See {@link #onFullBackup(FullBackupDataOutput)} for details on what directories
* are excluded from backups.
*
* @param file The file to be backed up. The file must exist and be readable by
* the caller.
* @param output The destination to which the backed-up file data will be sent.
*/
public final void fullBackupFile(File file, FullBackupDataOutput output) {
// Look up where all of our various well-defined dir trees live on this device
final String rootDir;
final String filesDir;
final String nbFilesDir;
final String dbDir;
final String spDir;
final String cacheDir;
final String codeCacheDir;
final String deviceRootDir;
final String deviceFilesDir;
final String deviceNbFilesDir;
final String deviceDbDir;
final String deviceSpDir;
final String deviceCacheDir;
final String deviceCodeCacheDir;
final String libDir;
String efDir = null;
String filePath;
ApplicationInfo appInfo = getApplicationInfo();
try {
// System apps have control over where their default storage context
// is pointed, so we're always explicit when building paths.
final Context ceContext = createCredentialProtectedStorageContext();
rootDir = ceContext.getDataDir().getCanonicalPath();
filesDir = ceContext.getFilesDir().getCanonicalPath();
nbFilesDir = ceContext.getNoBackupFilesDir().getCanonicalPath();
dbDir = ceContext.getDatabasePath("foo").getParentFile().getCanonicalPath();
spDir = ceContext.getSharedPreferencesPath("foo").getParentFile().getCanonicalPath();
cacheDir = ceContext.getCacheDir().getCanonicalPath();
codeCacheDir = ceContext.getCodeCacheDir().getCanonicalPath();
final Context deContext = createDeviceProtectedStorageContext();
deviceRootDir = deContext.getDataDir().getCanonicalPath();
deviceFilesDir = deContext.getFilesDir().getCanonicalPath();
deviceNbFilesDir = deContext.getNoBackupFilesDir().getCanonicalPath();
deviceDbDir = deContext.getDatabasePath("foo").getParentFile().getCanonicalPath();
deviceSpDir = deContext.getSharedPreferencesPath("foo").getParentFile()
.getCanonicalPath();
deviceCacheDir = deContext.getCacheDir().getCanonicalPath();
deviceCodeCacheDir = deContext.getCodeCacheDir().getCanonicalPath();
libDir = (appInfo.nativeLibraryDir == null)
? null
: new File(appInfo.nativeLibraryDir).getCanonicalPath();
// may or may not have external files access to attempt backup/restore there
if (Process.myUid() != Process.SYSTEM_UID) {
File efLocation = getExternalFilesDir(null);
if (efLocation != null) {
efDir = efLocation.getCanonicalPath();
}
}
// Now figure out which well-defined tree the file is placed in, working from
// most to least specific. We also specifically exclude the lib, cache,
// and code_cache dirs.
filePath = file.getCanonicalPath();
} catch (IOException e) {
Log.w(TAG, "Unable to obtain canonical paths");
return;
}
if (filePath.startsWith(cacheDir)
|| filePath.startsWith(codeCacheDir)
|| filePath.startsWith(nbFilesDir)
|| filePath.startsWith(deviceCacheDir)
|| filePath.startsWith(deviceCodeCacheDir)
|| filePath.startsWith(deviceNbFilesDir)
|| filePath.startsWith(libDir)) {
Log.w(TAG, "lib, cache, code_cache, and no_backup files are not backed up");
return;
}
final String domain;
String rootpath = null;
if (filePath.startsWith(dbDir)) {
domain = FullBackup.DATABASE_TREE_TOKEN;
rootpath = dbDir;
} else if (filePath.startsWith(spDir)) {
domain = FullBackup.SHAREDPREFS_TREE_TOKEN;
rootpath = spDir;
} else if (filePath.startsWith(filesDir)) {
domain = FullBackup.FILES_TREE_TOKEN;
rootpath = filesDir;
} else if (filePath.startsWith(rootDir)) {
domain = FullBackup.ROOT_TREE_TOKEN;
rootpath = rootDir;
} else if (filePath.startsWith(deviceDbDir)) {
domain = FullBackup.DEVICE_DATABASE_TREE_TOKEN;
rootpath = deviceDbDir;
} else if (filePath.startsWith(deviceSpDir)) {
domain = FullBackup.DEVICE_SHAREDPREFS_TREE_TOKEN;
rootpath = deviceSpDir;
} else if (filePath.startsWith(deviceFilesDir)) {
domain = FullBackup.DEVICE_FILES_TREE_TOKEN;
rootpath = deviceFilesDir;
} else if (filePath.startsWith(deviceRootDir)) {
domain = FullBackup.DEVICE_ROOT_TREE_TOKEN;
rootpath = deviceRootDir;
} else if ((efDir != null) && filePath.startsWith(efDir)) {
domain = FullBackup.MANAGED_EXTERNAL_TREE_TOKEN;
rootpath = efDir;
} else {
Log.w(TAG, "File " + filePath + " is in an unsupported location; skipping");
return;
}
// And now that we know where it lives, semantically, back it up appropriately
// In the measurement case, backupToTar() updates the size in output and returns
// without transmitting any file data.
if (DEBUG) Log.i(TAG, "backupFile() of " + filePath + " => domain=" + domain
+ " rootpath=" + rootpath);
FullBackup.backupToTar(getPackageName(), domain, null, rootpath, filePath, output);
}
/**
* Scan the dir tree (if it actually exists) and process each entry we find. If the
* 'excludes' parameters are non-null, they are consulted each time a new file system entity
* is visited to see whether that entity (and its subtree, if appropriate) should be
* omitted from the backup process.
*
* @param systemExcludes An optional list of excludes.
* @hide
*/
protected final void fullBackupFileTree(String packageName, String domain, String startingPath,
Set manifestExcludes,
ArraySet systemExcludes,
FullBackupDataOutput output) {
// Pull out the domain and set it aside to use when making the tarball.
String domainPath = FullBackup.getBackupScheme(this, mOperationType)
.tokenToDirectoryPath(domain);
if (domainPath == null) {
// Should never happen.
return;
}
File rootFile = new File(startingPath);
if (rootFile.exists()) {
LinkedList scanQueue = new LinkedList();
scanQueue.add(rootFile);
while (scanQueue.size() > 0) {
File file = scanQueue.remove(0);
String filePath;
try {
// Ignore things that aren't "real" files or dirs
StructStat stat = Os.lstat(file.getPath());
if (!OsConstants.S_ISREG(stat.st_mode)
&& !OsConstants.S_ISDIR(stat.st_mode)) {
if (DEBUG) Log.i(TAG, "Not a file/dir (skipping)!: " + file);
continue;
}
// For all other verification, look at the canonicalized path
filePath = file.getCanonicalPath();
// prune this subtree?
if (manifestExcludes != null
&& manifestExcludesContainFilePath(manifestExcludes, filePath)) {
continue;
}
if (systemExcludes != null && systemExcludes.contains(filePath)) {
continue;
}
// If it's a directory, enqueue its contents for scanning.
if (OsConstants.S_ISDIR(stat.st_mode)) {
File[] contents = file.listFiles();
if (contents != null) {
for (File entry : contents) {
scanQueue.add(0, entry);
}
}
}
} catch (IOException e) {
if (DEBUG) Log.w(TAG, "Error canonicalizing path of " + file);
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER, "Error canonicalizing path of " + file);
}
continue;
} catch (ErrnoException e) {
if (DEBUG) Log.w(TAG, "Error scanning file " + file + " : " + e);
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER, "Error scanning file " + file + " : " + e);
}
continue;
}
// Finally, back this file up (or measure it) before proceeding
FullBackup.backupToTar(packageName, domain, null, domainPath, filePath, output);
}
}
}
private boolean manifestExcludesContainFilePath(
Set manifestExcludes, String filePath) {
for (PathWithRequiredFlags exclude : manifestExcludes) {
String excludePath = exclude.getPath();
if (excludePath != null && excludePath.equals(filePath)) {
return true;
}
}
return false;
}
/**
* Handle the data delivered via the given file descriptor during a full restore
* operation. The agent is given the path to the file's original location as well
* as its size and metadata.
*
* The file descriptor can only be read for {@code size} bytes; attempting to read
* more data has undefined behavior.
*
* The default implementation creates the destination file/directory and populates it
* with the data from the file descriptor, then sets the file's access mode and
* modification time to match the restore arguments.
*
* @param data A read-only file descriptor from which the agent can read {@code size}
* bytes of file data.
* @param size The number of bytes of file content to be restored to the given
* destination. If the file system object being restored is a directory, {@code size}
* will be zero.
* @param destination The File on disk to be restored with the given data.
* @param type The kind of file system object being restored. This will be either
* {@link BackupAgent#TYPE_FILE} or {@link BackupAgent#TYPE_DIRECTORY}.
* @param mode The access mode to be assigned to the destination after its data is
* written. This is in the standard format used by {@code chmod()}.
* @param mtime The modification time of the file when it was backed up, suitable to
* be assigned to the file after its data is written.
* @throws IOException
*/
public void onRestoreFile(ParcelFileDescriptor data, long size,
File destination, int type, long mode, long mtime)
throws IOException {
final boolean accept = isFileEligibleForRestore(destination);
// If we don't accept the file, consume the bytes from the pipe anyway.
FullBackup.restoreFile(data, size, type, mode, mtime, accept ? destination : null);
}
private boolean isFileEligibleForRestore(File destination) throws IOException {
FullBackup.BackupScheme bs = FullBackup.getBackupScheme(this, mOperationType);
if (!bs.isFullRestoreEnabled()) {
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER,
"onRestoreFile \"" + destination.getCanonicalPath()
+ "\" : fullBackupContent not enabled for " + getPackageName());
}
return false;
}
Map> includes = null;
ArraySet excludes = null;
final String destinationCanonicalPath = destination.getCanonicalPath();
try {
includes = bs.maybeParseAndGetCanonicalIncludePaths();
excludes = bs.maybeParseAndGetCanonicalExcludePaths();
} catch (XmlPullParserException e) {
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER,
"onRestoreFile \"" + destinationCanonicalPath
+ "\" : Exception trying to parse fullBackupContent xml file!"
+ " Aborting onRestoreFile.", e);
}
return false;
}
if (excludes != null &&
BackupUtils.isFileSpecifiedInPathList(destination, excludes)) {
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER,
"onRestoreFile: \"" + destinationCanonicalPath + "\": listed in"
+ " excludes; skipping.");
}
return false;
}
if (includes != null && !includes.isEmpty()) {
// Rather than figure out the domainIncludes : includes.values()) {
explicitlyIncluded |=
BackupUtils.isFileSpecifiedInPathList(destination, domainIncludes);
if (explicitlyIncluded) {
break;
}
}
if (!explicitlyIncluded) {
if (Log.isLoggable(FullBackup.TAG_XML_PARSER, Log.VERBOSE)) {
Log.v(FullBackup.TAG_XML_PARSER,
"onRestoreFile: Trying to restore \""
+ destinationCanonicalPath + "\" but it isn't specified"
+ " in the included files; skipping.");
}
return false;
}
}
return true;
}
/**
* Only specialized platform agents should overload this entry point to support
* restores to non-app locations.
* @hide
*/
protected void onRestoreFile(ParcelFileDescriptor data, long size,
int type, String domain, String path, long mode, long mtime)
throws IOException {
String basePath = null;
if (DEBUG) Log.d(TAG, "onRestoreFile() size=" + size + " type=" + type
+ " domain=" + domain + " relpath=" + path + " mode=" + mode
+ " mtime=" + mtime);
basePath = FullBackup.getBackupScheme(this, mOperationType).tokenToDirectoryPath(
domain);
if (domain.equals(FullBackup.MANAGED_EXTERNAL_TREE_TOKEN)) {
mode = -1; // < 0 is a token to skip attempting a chmod()
}
// Now that we've figured out where the data goes, send it on its way
if (basePath != null) {
// Canonicalize the nominal path and verify that it lies within the stated domain
File outFile = new File(basePath, path);
String outPath = outFile.getCanonicalPath();
if (outPath.startsWith(basePath + File.separatorChar)) {
if (DEBUG) Log.i(TAG, "[" + domain + " : " + path + "] mapped to " + outPath);
onRestoreFile(data, size, outFile, type, mode, mtime);
return;
} else {
// Attempt to restore to a path outside the file's nominal domain.
if (DEBUG) {
Log.e(TAG, "Cross-domain restore attempt: " + outPath);
}
}
}
// Not a supported output location, or bad path: we need to consume the data
// anyway, so just use the default "copy the data out" implementation
// with a null destination.
if (DEBUG) Log.i(TAG, "[ skipping file " + path + "]");
FullBackup.restoreFile(data, size, type, mode, mtime, null);
}
/**
* The application's restore operation has completed. This method is called after
* all available data has been delivered to the application for restore (via either
* the {@link #onRestore(BackupDataInput, int, ParcelFileDescriptor) onRestore()} or
* {@link #onRestoreFile(ParcelFileDescriptor, long, File, int, long, long) onRestoreFile()}
* callbacks). This provides the app with a stable end-of-restore opportunity to
* perform any appropriate post-processing on the data that was just delivered.
*
* @see #onRestore(BackupDataInput, int, ParcelFileDescriptor)
* @see #onRestoreFile(ParcelFileDescriptor, long, File, int, long, long)
*/
public void onRestoreFinished() {
}
// ----- Core implementation -----
/** @hide */
public final IBinder onBind() {
return mBinder;
}
private final IBinder mBinder = new BackupServiceBinder().asBinder();
/** @hide */
public void attach(Context context) {
attachBaseContext(context);
}
// ----- IBackupService binder interface -----
private class BackupServiceBinder extends IBackupAgent.Stub {
private static final String TAG = "BackupServiceBinder";
@Override
public void doBackup(
ParcelFileDescriptor oldState,
ParcelFileDescriptor data,
ParcelFileDescriptor newState,
long quotaBytes,
IBackupCallback callbackBinder,
int transportFlags) throws RemoteException {
if (DEBUG) Log.v(TAG, "doBackup() invoked");
BackupDataOutput output = new BackupDataOutput(
data.getFileDescriptor(), quotaBytes, transportFlags);
long result = RESULT_ERROR;
// Ensure that we're running with the app's normal permission level
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onBackup(oldState, output, newState);
result = RESULT_SUCCESS;
} catch (IOException ex) {
Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw new RuntimeException(ex);
} catch (RuntimeException ex) {
Log.d(TAG, "onBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw ex;
} finally {
// Ensure that any SharedPreferences writes have landed after the backup,
// in case the app code has side effects (since apps cannot provide this
// guarantee themselves).
waitForSharedPrefs();
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.operationComplete(result);
} catch (RemoteException e) {
// We will time out anyway.
}
// Don't close the fd out from under the system service if this was local
if (Binder.getCallingPid() != Process.myPid()) {
IoUtils.closeQuietly(oldState);
IoUtils.closeQuietly(data);
IoUtils.closeQuietly(newState);
}
}
}
@Override
public void doRestore(ParcelFileDescriptor data, long appVersionCode,
ParcelFileDescriptor newState, int token, IBackupManager callbackBinder)
throws RemoteException {
doRestoreInternal(data, appVersionCode, newState, token, callbackBinder,
/* excludedKeys */ null);
}
@Override
public void doRestoreWithExcludedKeys(ParcelFileDescriptor data, long appVersionCode,
ParcelFileDescriptor newState, int token, IBackupManager callbackBinder,
List excludedKeys) throws RemoteException {
doRestoreInternal(data, appVersionCode, newState, token, callbackBinder, excludedKeys);
}
private void doRestoreInternal(ParcelFileDescriptor data, long appVersionCode,
ParcelFileDescriptor newState, int token, IBackupManager callbackBinder,
List excludedKeys) throws RemoteException {
if (DEBUG) Log.v(TAG, "doRestore() invoked");
// Ensure that any side-effect SharedPreferences writes have landed *before*
// we may be about to rewrite the file out from underneath
waitForSharedPrefs();
BackupDataInput input = new BackupDataInput(data.getFileDescriptor());
// Ensure that we're running with the app's normal permission level
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onRestore(input, appVersionCode, newState,
excludedKeys != null ? new HashSet<>(excludedKeys)
: Collections.emptySet());
} catch (IOException ex) {
Log.d(TAG, "onRestore (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw new RuntimeException(ex);
} catch (RuntimeException ex) {
Log.d(TAG, "onRestore (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw ex;
} finally {
// And bring live SharedPreferences instances up to date
reloadSharedPreferences();
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.opCompleteForUser(getBackupUserId(), token, 0);
} catch (RemoteException e) {
// we'll time out anyway, so we're safe
}
if (Binder.getCallingPid() != Process.myPid()) {
IoUtils.closeQuietly(data);
IoUtils.closeQuietly(newState);
}
}
}
@Override
public void doFullBackup(ParcelFileDescriptor data,
long quotaBytes, int token, IBackupManager callbackBinder, int transportFlags) {
if (DEBUG) Log.v(TAG, "doFullBackup() invoked");
// Ensure that any SharedPreferences writes have landed *before*
// we potentially try to back up the underlying files directly.
waitForSharedPrefs();
// Ensure that we're running with the app's normal permission level
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onFullBackup(new FullBackupDataOutput(
data, quotaBytes, transportFlags));
} catch (IOException ex) {
Log.d(TAG, "onFullBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw new RuntimeException(ex);
} catch (RuntimeException ex) {
Log.d(TAG, "onFullBackup (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw ex;
} finally {
// ... and then again after, as in the doBackup() case
waitForSharedPrefs();
// Send the EOD marker indicating that there is no more data
// forthcoming from this agent.
try {
FileOutputStream out = new FileOutputStream(data.getFileDescriptor());
byte[] buf = new byte[4];
out.write(buf);
} catch (IOException e) {
Log.e(TAG, "Unable to finalize backup stream!");
}
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.opCompleteForUser(getBackupUserId(), token, 0);
} catch (RemoteException e) {
// we'll time out anyway, so we're safe
}
if (Binder.getCallingPid() != Process.myPid()) {
IoUtils.closeQuietly(data);
}
}
}
public void doMeasureFullBackup(long quotaBytes, int token, IBackupManager callbackBinder,
int transportFlags) {
FullBackupDataOutput measureOutput =
new FullBackupDataOutput(quotaBytes, transportFlags);
waitForSharedPrefs();
// Ensure that we're running with the app's normal permission level
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onFullBackup(measureOutput);
} catch (IOException ex) {
Log.d(TAG, "onFullBackup[M] (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw new RuntimeException(ex);
} catch (RuntimeException ex) {
Log.d(TAG, "onFullBackup[M] (" + BackupAgent.this.getClass().getName() + ") threw", ex);
throw ex;
} finally {
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.opCompleteForUser(getBackupUserId(), token,
measureOutput.getSize());
} catch (RemoteException e) {
// timeout, so we're safe
}
}
}
@Override
public void doRestoreFile(ParcelFileDescriptor data, long size,
int type, String domain, String path, long mode, long mtime,
int token, IBackupManager callbackBinder) throws RemoteException {
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onRestoreFile(data, size, type, domain, path, mode, mtime);
} catch (IOException e) {
Log.d(TAG, "onRestoreFile (" + BackupAgent.this.getClass().getName() + ") threw", e);
throw new RuntimeException(e);
} finally {
// Ensure that any side-effect SharedPreferences writes have landed
waitForSharedPrefs();
// And bring live SharedPreferences instances up to date
reloadSharedPreferences();
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.opCompleteForUser(getBackupUserId(), token, 0);
} catch (RemoteException e) {
// we'll time out anyway, so we're safe
}
if (Binder.getCallingPid() != Process.myPid()) {
IoUtils.closeQuietly(data);
}
}
}
@Override
public void doRestoreFinished(int token, IBackupManager callbackBinder) {
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onRestoreFinished();
} catch (Exception e) {
Log.d(TAG, "onRestoreFinished (" + BackupAgent.this.getClass().getName() + ") threw", e);
throw e;
} finally {
// Ensure that any side-effect SharedPreferences writes have landed
waitForSharedPrefs();
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.opCompleteForUser(getBackupUserId(), token, 0);
} catch (RemoteException e) {
// we'll time out anyway, so we're safe
}
}
}
@Override
public void fail(String message) {
getHandler().post(new FailRunnable(message));
}
@Override
public void doQuotaExceeded(
long backupDataBytes,
long quotaBytes,
IBackupCallback callbackBinder) {
long result = RESULT_ERROR;
// Ensure that we're running with the app's normal permission level
final long ident = Binder.clearCallingIdentity();
try {
BackupAgent.this.onQuotaExceeded(backupDataBytes, quotaBytes);
result = RESULT_SUCCESS;
} catch (Exception e) {
Log.d(TAG, "onQuotaExceeded(" + BackupAgent.this.getClass().getName() + ") threw",
e);
throw e;
} finally {
waitForSharedPrefs();
Binder.restoreCallingIdentity(ident);
try {
callbackBinder.operationComplete(result);
} catch (RemoteException e) {
// We will time out anyway.
}
}
}
}
static class FailRunnable implements Runnable {
private String mMessage;
FailRunnable(String message) {
mMessage = message;
}
@Override
public void run() {
throw new IllegalStateException(mMessage);
}
}
/** @hide */
@VisibleForTesting
public static class IncludeExcludeRules {
private final Map> mManifestIncludeMap;
private final Set mManifestExcludeSet;
/** @hide */
public IncludeExcludeRules(
Map> manifestIncludeMap,
Set manifestExcludeSet) {
mManifestIncludeMap = manifestIncludeMap;
mManifestExcludeSet = manifestExcludeSet;
}
/** @hide */
@VisibleForTesting
public static IncludeExcludeRules emptyRules() {
return new IncludeExcludeRules(Collections.emptyMap(), new ArraySet<>());
}
private Map> getIncludeMap() {
return mManifestIncludeMap;
}
private Set getExcludeSet() {
return mManifestExcludeSet;
}
/** @hide */
@Override
public int hashCode() {
return Objects.hash(mManifestIncludeMap, mManifestExcludeSet);
}
/** @hide */
@Override
public boolean equals(@Nullable Object object) {
if (this == object) {
return true;
}
if (object == null || getClass() != object.getClass()) {
return false;
}
IncludeExcludeRules that = (IncludeExcludeRules) object;
return Objects.equals(mManifestIncludeMap, that.mManifestIncludeMap) &&
Objects.equals(mManifestExcludeSet, that.mManifestExcludeSet);
}
}
}