Store the app signatures as part of the backup set
Under a pseudo-app for the Package Manager, we store the app signatures for all participating applications installed on the device. At restore time we will restore this first, then ensure that the current on-device signature chain is compatible with the one in the backup set. If there's a mismatch, this may be a spoof attempt and we will refuse to restore that app's data. The restore side of this is not implemented, but the Package Manager agent is here as well as the backup side theoretically pushing the data now.
This commit is contained in:
Christopher Tate
@@ -52,6 +52,8 @@ import android.backup.RestoreSet;
|
||||
import com.android.internal.backup.LocalTransport;
|
||||
import com.android.internal.backup.IBackupTransport;
|
||||
|
||||
import com.android.server.PackageManagerBackupAgent;
|
||||
|
||||
import java.io.EOFException;
|
||||
import java.io.File;
|
||||
import java.io.FileDescriptor;
|
||||
@@ -70,6 +72,7 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
private static final String TAG = "BackupManagerService";
|
||||
private static final boolean DEBUG = true;
|
||||
|
||||
// Default time to wait after data changes before we back up the data
|
||||
private static final long COLLECTION_INTERVAL = 1000;
|
||||
//private static final long COLLECTION_INTERVAL = 3 * 60 * 1000;
|
||||
|
||||
@@ -104,6 +107,9 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
// Backups that we haven't started yet.
|
||||
private HashMap<ApplicationInfo,BackupRequest> mPendingBackups
|
||||
= new HashMap<ApplicationInfo,BackupRequest>();
|
||||
// Do we need to back up the package manager metadata on the next pass?
|
||||
private boolean mDoPackageManager;
|
||||
private static final String PACKAGE_MANAGER_SENTINEL = "@pm@";
|
||||
// Backups that we have started. These are separate to prevent starvation
|
||||
// if an app keeps re-enqueuing itself.
|
||||
private ArrayList<BackupRequest> mBackupQueue;
|
||||
@@ -363,12 +369,13 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
mBackupParticipants.put(uid, set);
|
||||
}
|
||||
set.add(app);
|
||||
backUpPackageManagerData();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Remove the given package's backup services from our known active set. If
|
||||
// 'packageName' is null, *all* backup services will be removed.
|
||||
// Remove the given package's entry from our known active set. If
|
||||
// 'packageName' is null, *all* participating apps will be removed.
|
||||
void removePackageParticipantsLocked(String packageName) {
|
||||
if (DEBUG) Log.v(TAG, "removePackageParticipantsLocked: " + packageName);
|
||||
List<ApplicationInfo> allApps = null;
|
||||
@@ -406,6 +413,7 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
for (ApplicationInfo entry: set) {
|
||||
if (entry.packageName.equals(app.packageName)) {
|
||||
set.remove(entry);
|
||||
backUpPackageManagerData();
|
||||
break;
|
||||
}
|
||||
}
|
||||
@@ -418,6 +426,7 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
|
||||
// Returns the set of all applications that define an android:backupAgent attribute
|
||||
private List<ApplicationInfo> allAgentApps() {
|
||||
// !!! TODO: cache this and regenerate only when necessary
|
||||
List<ApplicationInfo> allApps = mPackageManager.getInstalledApplications(0);
|
||||
int N = allApps.size();
|
||||
if (N > 0) {
|
||||
@@ -447,13 +456,29 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
addPackageParticipantsLockedInner(packageName, allApps);
|
||||
}
|
||||
|
||||
private void backUpPackageManagerData() {
|
||||
// No need to schedule a backup just for the metadata; just piggyback on
|
||||
// the next actual data backup.
|
||||
synchronized(this) {
|
||||
mDoPackageManager = true;
|
||||
}
|
||||
}
|
||||
|
||||
// The queue lock should be held when scheduling a backup pass
|
||||
private void scheduleBackupPassLocked(long timeFromNowMillis) {
|
||||
mBackupHandler.removeMessages(MSG_RUN_BACKUP);
|
||||
mBackupHandler.sendEmptyMessageDelayed(MSG_RUN_BACKUP, timeFromNowMillis);
|
||||
}
|
||||
|
||||
// Return the given transport
|
||||
private IBackupTransport getTransport(int transportID) {
|
||||
switch (transportID) {
|
||||
case BackupManager.TRANSPORT_LOCAL:
|
||||
Log.v(TAG, "Supplying local transport");
|
||||
return mLocalTransport;
|
||||
|
||||
case BackupManager.TRANSPORT_GOOGLE:
|
||||
Log.v(TAG, "Supplying Google transport");
|
||||
return mGoogleTransport;
|
||||
|
||||
default:
|
||||
@@ -558,7 +583,29 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
return;
|
||||
}
|
||||
|
||||
// The transport is up and running; now run all the backups in our queue
|
||||
// The transport is up and running. First, back up the package manager
|
||||
// metadata if necessary
|
||||
boolean doPackageManager;
|
||||
synchronized (BackupManagerService.this) {
|
||||
doPackageManager = mDoPackageManager;
|
||||
mDoPackageManager = false;
|
||||
}
|
||||
if (doPackageManager) {
|
||||
// The package manager doesn't have a proper <application> etc, but since
|
||||
// it's running here in the system process we can just set up its agent
|
||||
// directly and use a synthetic BackupRequest.
|
||||
if (DEBUG) Log.i(TAG, "Running PM backup pass as well");
|
||||
|
||||
PackageManagerBackupAgent pmAgent = new PackageManagerBackupAgent(
|
||||
mPackageManager, allAgentApps());
|
||||
BackupRequest pmRequest = new BackupRequest(new ApplicationInfo(), false);
|
||||
pmRequest.appInfo.packageName = PACKAGE_MANAGER_SENTINEL;
|
||||
processOneBackup(pmRequest,
|
||||
IBackupAgent.Stub.asInterface(pmAgent.onBind()),
|
||||
mTransport);
|
||||
}
|
||||
|
||||
// Now run all the backups in our queue
|
||||
doQueuedBackups(mTransport);
|
||||
|
||||
// Finally, tear down the transport
|
||||
@@ -735,6 +782,8 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
}
|
||||
|
||||
if (err == 0) {
|
||||
// !!! TODO: do the package manager signatures restore first
|
||||
|
||||
// build the set of apps to restore
|
||||
try {
|
||||
RestoreSet[] images = mTransport.getAvailableRestoreSets();
|
||||
@@ -920,8 +969,7 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
// Schedule a backup pass in a few minutes. As backup-eligible data
|
||||
// keeps changing, continue to defer the backup pass until things
|
||||
// settle down, to avoid extra overhead.
|
||||
mBackupHandler.removeMessages(MSG_RUN_BACKUP);
|
||||
mBackupHandler.sendEmptyMessageDelayed(MSG_RUN_BACKUP, COLLECTION_INTERVAL);
|
||||
scheduleBackupPassLocked(COLLECTION_INTERVAL);
|
||||
}
|
||||
} else {
|
||||
Log.w(TAG, "dataChanged but no participant pkg " + packageName);
|
||||
@@ -947,8 +995,7 @@ class BackupManagerService extends IBackupManager.Stub {
|
||||
|
||||
if (DEBUG) Log.v(TAG, "Scheduling immediate backup pass");
|
||||
synchronized (mQueueLock) {
|
||||
mBackupHandler.removeMessages(MSG_RUN_BACKUP);
|
||||
mBackupHandler.sendEmptyMessage(MSG_RUN_BACKUP);
|
||||
scheduleBackupPassLocked(0);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user