Fix shared-storage full backup

The special shared-storage step was mistakenly writing its data directly
to the USB output pipe rather than to the proper stacked data handling
chain that applies compression and encryption.  Fix this by getting rid
of the custom handling of the shared-storage data, instead folding it
into the normal data handling flow [with a small amount of additional
management because e.g. it doesn't need a "manifest" pseudofile in the
archive stream].

Fixes bug 5897791

Change-Id: I3995b07963334d2f8cce49b247c87d3d3ff93bed

1 files changed, 35 insertions, 46 deletions

diff --git a/services/java/com/android/server/BackupManagerService.java b/services/java/com/android/server/BackupManagerService.java
index aebfd60..31515e1 100644
--- a/services/java/com/android/server/BackupManagerService.java
+++ b/services/java/com/android/server/BackupManagerService.java
@@ -140,6 +140,8 @@ class BackupManagerService extends IBackupManager.Stub {
     static final int BACKUP_FILE_VERSION = 1;
     static final boolean COMPRESS_FULL_BACKUPS = true; // should be true in production
 
+    static final String SHARED_BACKUP_AGENT_PACKAGE = "com.android.sharedstoragebackup";
+
     // How often we perform a backup pass.  Privileged external callers can
     // trigger an immediate pass.
     private static final long BACKUP_INTERVAL = AlarmManager.INTERVAL_HOUR;
@@ -2325,14 +2327,16 @@ class BackupManagerService extends IBackupManager.Stub {
             ParcelFileDescriptor mPipe;
             int mToken;
             boolean mSendApk;
+            boolean mWriteManifest;
 
             FullBackupRunner(PackageInfo pack, IBackupAgent agent, ParcelFileDescriptor pipe,
-                    int token, boolean sendApk)  throws IOException {
+                    int token, boolean sendApk, boolean writeManifest)  throws IOException {
                 mPackage = pack;
                 mAgent = agent;
                 mPipe = ParcelFileDescriptor.dup(pipe.getFileDescriptor());
                 mToken = token;
                 mSendApk = sendApk;
+                mWriteManifest = writeManifest;
             }
 
             @Override
@@ -2341,12 +2345,14 @@ class BackupManagerService extends IBackupManager.Stub {
                     BackupDataOutput output = new BackupDataOutput(
                             mPipe.getFileDescriptor());
 
-                    if (MORE_DEBUG) Slog.d(TAG, "Writing manifest for " + mPackage.packageName);
-                    writeAppManifest(mPackage, mManifestFile, mSendApk);
-                    FullBackup.backupToTar(mPackage.packageName, null, null,
-                            mFilesDir.getAbsolutePath(),
-                            mManifestFile.getAbsolutePath(),
-                            output);
+                    if (mWriteManifest) {
+                        if (MORE_DEBUG) Slog.d(TAG, "Writing manifest for " + mPackage.packageName);
+                        writeAppManifest(mPackage, mManifestFile, mSendApk);
+                        FullBackup.backupToTar(mPackage.packageName, null, null,
+                                mFilesDir.getAbsolutePath(),
+                                mManifestFile.getAbsolutePath(),
+                                output);
+                    }
 
                     if (mSendApk) {
                         writeApkToBackup(mPackage, output);
@@ -2433,10 +2439,13 @@ class BackupManagerService extends IBackupManager.Stub {
                 }
             }
 
-            // Cull any packages that have indicated that backups are not permitted.
+            // Cull any packages that have indicated that backups are not permitted, as well
+            // as any explicit mention of the 'special' shared-storage agent package (we
+            // handle that one at the end).
             for (int i = 0; i < packagesToBackup.size(); ) {
                 PackageInfo pkg = packagesToBackup.get(i);
-                if ((pkg.applicationInfo.flags & ApplicationInfo.FLAG_ALLOW_BACKUP) == 0) {
+                if ((pkg.applicationInfo.flags & ApplicationInfo.FLAG_ALLOW_BACKUP) == 0
+                        || pkg.packageName.equals(SHARED_BACKUP_AGENT_PACKAGE)) {
                     packagesToBackup.remove(i);
                 } else {
                     i++;
@@ -2516,6 +2525,16 @@ class BackupManagerService extends IBackupManager.Stub {
                     return;
                 }
 
+                // Shared storage if requested
+                if (mIncludeShared) {
+                    try {
+                        pkg = mPackageManager.getPackageInfo(SHARED_BACKUP_AGENT_PACKAGE, 0);
+                        packagesToBackup.add(pkg);
+                    } catch (NameNotFoundException e) {
+                        Slog.e(TAG, "Unable to find shared-storage backup handler");
+                    }
+                }
+
                 // Now back up the app data via the agent mechanism
                 int N = packagesToBackup.size();
                 for (int i = 0; i < N; i++) {
@@ -2523,11 +2542,6 @@ class BackupManagerService extends IBackupManager.Stub {
                     backupOnePackage(pkg, out);
                 }
 
-                // Shared storage if requested
-                if (mIncludeShared) {
-                    backupSharedStorage();
-                }
-
                 // Done!
                 finalizeBackup(out);
             } catch (RemoteException e) {
@@ -2633,19 +2647,21 @@ class BackupManagerService extends IBackupManager.Stub {
             if (agent != null) {
                 ParcelFileDescriptor[] pipes = null;
                 try {
-                     pipes = ParcelFileDescriptor.createPipe();
+                    pipes = ParcelFileDescriptor.createPipe();
 
                     ApplicationInfo app = pkg.applicationInfo;
+                    final boolean isSharedStorage = pkg.packageName.equals(SHARED_BACKUP_AGENT_PACKAGE);
                     final boolean sendApk = mIncludeApks
+                            && !isSharedStorage
                             && ((app.flags & ApplicationInfo.FLAG_FORWARD_LOCK) == 0)
                             && ((app.flags & ApplicationInfo.FLAG_SYSTEM) == 0 ||
                                 (app.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0);
 
-                    sendOnBackupPackage(pkg.packageName);
+                    sendOnBackupPackage(isSharedStorage ? "Shared storage" : pkg.packageName);
 
                     final int token = generateToken();
                     FullBackupRunner runner = new FullBackupRunner(pkg, agent, pipes[1],
-                            token, sendApk);
+                            token, sendApk, !isSharedStorage);
                     pipes[1].close();   // the runner has dup'd it
                     pipes[1] = null;
                     Thread t = new Thread(runner);
@@ -2720,33 +2736,6 @@ class BackupManagerService extends IBackupManager.Stub {
             }
         }
 
-        private void backupSharedStorage() throws RemoteException {
-            PackageInfo pkg = null;
-            try {
-                pkg = mPackageManager.getPackageInfo("com.android.sharedstoragebackup", 0);
-                IBackupAgent agent = bindToAgentSynchronous(pkg.applicationInfo,
-                        IApplicationThread.BACKUP_MODE_FULL);
-                if (agent != null) {
-                    sendOnBackupPackage("Shared storage");
-
-                    final int token = generateToken();
-                    prepareOperationTimeout(token, TIMEOUT_SHARED_BACKUP_INTERVAL, null);
-                    agent.doFullBackup(mOutputFile, token, mBackupManagerBinder);
-                    if (!waitUntilOperationComplete(token)) {
-                        Slog.e(TAG, "Full backup failed on shared storage");
-                    } else {
-                        if (DEBUG) Slog.d(TAG, "Full shared storage backup success");
-                    }
-                } else {
-                    Slog.e(TAG, "Could not bind to shared storage backup agent");
-                }
-            } catch (NameNotFoundException e) {
-                Slog.e(TAG, "Shared storage backup package not found");
-            } finally {
-                tearDown(pkg);
-            }
-        }
-
         private void finalizeBackup(OutputStream out) {
             try {
                 // A standard 'tar' EOF sequence: two 512-byte blocks of all zeroes.
@@ -2972,7 +2961,7 @@ class BackupManagerService extends IBackupManager.Stub {
 
             // Are we able to restore shared-storage data?
             if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
-                mPackagePolicies.put("com.android.sharedstoragebackup", RestorePolicy.ACCEPT);
+                mPackagePolicies.put(SHARED_BACKUP_AGENT_PACKAGE, RestorePolicy.ACCEPT);
             }
 
             FileInputStream rawInStream = null;
@@ -3850,7 +3839,7 @@ class BackupManagerService extends IBackupManager.Stub {
                             info.path, 0, FullBackup.SHARED_PREFIX.length())) {
                         // File in shared storage.  !!! TODO: implement this.
                         info.path = info.path.substring(FullBackup.SHARED_PREFIX.length());
-                        info.packageName = "com.android.sharedstoragebackup";
+                        info.packageName = SHARED_BACKUP_AGENT_PACKAGE;
                         info.domain = FullBackup.SHARED_STORAGE_TOKEN;
                         if (DEBUG) Slog.i(TAG, "File in shared storage: " + info.path);
                     } else if (FullBackup.APPS_PREFIX.regionMatches(0,