Ensure we bind to the correct app's agent (64d73c4f) · Commits · e / os / android_frameworks_base

services/backup/java/com/android/server/backup/BackupAgentConnectionManager.java

+97 −51

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@ import android.os.UserHandle;
		import android.util.ArraySet;
		import android.util.Slog;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.annotations.VisibleForTesting;
		import com.android.server.LocalServices;
		import com.android.server.backup.internal.LifecycleOperationStorage;
		@@ -71,8 +72,10 @@ public class BackupAgentConnectionManager {
		// Activity Manager; use this lock object to signal when a requested binding has
		// completed.
		private final Object mAgentConnectLock = new Object();
		private IBackupAgent mConnectedAgent;
		private volatile boolean mConnecting;
		@GuardedBy("mAgentConnectLock")
		@Nullable
		private BackupAgentConnection mCurrentConnection;

		private final ArraySet<String> mRestoreNoRestrictedModePackages = new ArraySet<>();
		private final ArraySet<String> mBackupNoRestrictedModePackages = new ArraySet<>();

		@@ -96,8 +99,18 @@ public class BackupAgentConnectionManager {
		mUserIdMsg = "[UserID:" + userId + "] ";
		}

		private static final class BackupAgentConnection {
		public final ApplicationInfo appInfo;
		public IBackupAgent backupAgent;
		public boolean connecting = true; // Assume we are trying to connect on creation.

		private BackupAgentConnection(ApplicationInfo appInfo) {
		this.appInfo = appInfo;
		}
		}

		/**
		* Fires off a backup agent, blocking until it attaches (and ActivityManager will call
		* Fires off a backup agent, blocking until it attaches (i.e. ActivityManager calls
		* {@link #agentConnected(String, IBinder)}) or until this operation times out.
		*
		* @param mode a {@code BACKUP_MODE} from {@link android.app.ApplicationThreadConstants}.
		@@ -105,48 +118,56 @@ public class BackupAgentConnectionManager {
		@Nullable
		public IBackupAgent bindToAgentSynchronous(ApplicationInfo app, int mode,
		@BackupAnnotations.BackupDestination int backupDestination) {
		IBackupAgent agent = null;
		synchronized (mAgentConnectLock) {
		mConnecting = true;
		mConnectedAgent = null;
		boolean useRestrictedMode = shouldUseRestrictedBackupModeForPackage(mode,
		app.packageName);
		if (mCurrentConnection != null) {
		Slog.e(TAG, mUserIdMsg + "binding to new agent before unbinding from old one: "
		+ mCurrentConnection.appInfo.packageName);
		}
		mCurrentConnection = new BackupAgentConnection(app);

		// bindBackupAgent() is an async API. It will kick off the app's process and call
		// agentConnected() when it receives the agent from the app.
		boolean startedBindSuccessfully = false;
		try {
		if (mActivityManager.bindBackupAgent(app.packageName, mode, mUserId,
		backupDestination, useRestrictedMode)) {
		Slog.d(TAG, mUserIdMsg + "awaiting agent for " + app);
		startedBindSuccessfully = mActivityManager.bindBackupAgent(app.packageName, mode,
		mUserId, backupDestination, useRestrictedMode);
		} catch (RemoteException e) {
		// can't happen - ActivityManager is local
		}

		// success; wait for the agent to arrive
		// only wait 10 seconds for the bind to happen
		if (!startedBindSuccessfully) {
		Slog.w(TAG, mUserIdMsg + "bind request failed for " + app.packageName);
		mCurrentConnection = null;
		} else {
		Slog.d(TAG, mUserIdMsg + "awaiting agent for " + app.packageName);

		// Wait 10 seconds for the agent and then time out if we still haven't bound to it.
		long timeoutMark = System.currentTimeMillis() + 10 * 1000;
		while (mConnecting && mConnectedAgent == null && (System.currentTimeMillis()
		< timeoutMark)) {
		while (mCurrentConnection != null && mCurrentConnection.connecting && (
		System.currentTimeMillis() < timeoutMark)) {
		try {
		mAgentConnectLock.wait(5000);
		} catch (InterruptedException e) {
		// just bail
		Slog.w(TAG, mUserIdMsg + "Interrupted: " + e);
		mConnecting = false;
		mConnectedAgent = null;
		mCurrentConnection = null;
		}
		}

		// if we timed out with no connect, abort and move on
		if (mConnecting) {
		Slog.w(TAG, mUserIdMsg + "Timeout waiting for agent " + app);
		mConnectedAgent = null;
		}
		Slog.i(TAG, mUserIdMsg + "got agent " + mConnectedAgent);
		agent = mConnectedAgent;
		}
		} catch (RemoteException e) {
		// can't happen - ActivityManager is local

		if (mCurrentConnection != null) {
		if (!mCurrentConnection.connecting) {
		return mCurrentConnection.backupAgent;
		}
		// If we are still connecting, we've timed out.
		Slog.w(TAG, mUserIdMsg + "Timeout waiting for agent " + app);
		mCurrentConnection = null;
		}
		if (agent == null) {

		mActivityManagerInternal.clearPendingBackup(mUserId);
		return null;
		}
		return agent;
		}

		/**
		@@ -154,30 +175,49 @@ public class BackupAgentConnectionManager {
		* It will tell the app to destroy the agent.
		*/
		public void unbindAgent(ApplicationInfo app) {
		synchronized (mAgentConnectLock) {
		if (mCurrentConnection == null) {
		Slog.w(TAG, mUserIdMsg + "unbindAgent but no current connection");
		} else if (!mCurrentConnection.appInfo.packageName.equals(app.packageName)) {
		Slog.w(TAG, mUserIdMsg + "unbindAgent for unexpected package: " + app.packageName
		+ " expected: " + mCurrentConnection.appInfo.packageName);
		} else {
		mCurrentConnection = null;
		}

		// Even if we weren't expecting to be bound to this agent, we should still call
		// ActivityManager just in case. It will ignore the call if it also wasn't expecting it.
		try {
		mActivityManager.unbindBackupAgent(app);
		} catch (RemoteException e) {
		// Can't happen - activity manager is local
		}
		}
		}

		/**
		* Callback: a requested backup agent has been instantiated. This should only be called from
		* the
		* {@link ActivityManager} when it's telling us that an agent is ready after a call to
		* the {@link ActivityManager} when it's telling us that an agent is ready after a call to
		* {@link #bindToAgentSynchronous(ApplicationInfo, int, int)}.
		*/
		public void agentConnected(String packageName, IBinder agentBinder) {
		synchronized (mAgentConnectLock) {
		if (getCallingUid() == android.os.Process.SYSTEM_UID) {
		Slog.d(TAG,
		mUserIdMsg + "agentConnected pkg=" + packageName + " agent=" + agentBinder);
		mConnectedAgent = IBackupAgent.Stub.asInterface(agentBinder);
		mConnecting = false;
		} else {
		if (getCallingUid() != Process.SYSTEM_UID) {
		Slog.w(TAG, mUserIdMsg + "Non-system process uid=" + getCallingUid()
		+ " claiming agent connected");
		return;
		}

		Slog.d(TAG, mUserIdMsg + "agentConnected pkg=" + packageName + " agent=" + agentBinder);
		if (mCurrentConnection == null) {
		Slog.w(TAG, mUserIdMsg + "was not expecting connection");
		} else if (!mCurrentConnection.appInfo.packageName.equals(packageName)) {
		Slog.w(TAG, mUserIdMsg + "got agent for unexpected package=" + packageName);
		} else {
		mCurrentConnection.backupAgent = IBackupAgent.Stub.asInterface(agentBinder);
		mCurrentConnection.connecting = false;
		}

		mAgentConnectLock.notifyAll();
		}
		}
		@@ -189,16 +229,22 @@ public class BackupAgentConnectionManager {
		*/
		public void agentDisconnected(String packageName) {
		synchronized (mAgentConnectLock) {
		if (getCallingUid() == Process.SYSTEM_UID) {
		mConnectedAgent = null;
		mConnecting = false;
		} else {
		if (getCallingUid() != Process.SYSTEM_UID) {
		Slog.w(TAG, mUserIdMsg + "Non-system process uid=" + getCallingUid()
		+ " claiming agent disconnected");
		return;
		}

		Slog.w(TAG, mUserIdMsg + "agentDisconnected: the backup agent for " + packageName
		+ " died: cancel current operations");

		// Only abort the current connection if the agent we were expecting or already
		// connected to has disconnected.
		if (mCurrentConnection != null && mCurrentConnection.appInfo.packageName.equals(
		packageName)) {
		mCurrentConnection = null;
		}

		// Offload operation cancellation off the main thread as the cancellation callbacks
		// might call out to BackupTransport. Other operations started on the same package
		// before the cancellation callback has executed will also be cancelled by the callback.

services/tests/mockingservicestests/src/com/android/server/backup/BackupAgentConnectionManagerTest.java

+26 −0

Original line number	Diff line number	Diff line
		@@ -195,6 +195,31 @@ public class BackupAgentConnectionManagerTest {
		verify(mActivityManagerInternal, never()).clearPendingBackup(anyInt());
		}

		@Test
		public void bindToAgentSynchronous_unexpectedAgentConnected_doesNotReturnWrongAgent()
		throws Exception {
		when(mActivityManager.bindBackupAgent(eq(TEST_PACKAGE), anyInt(), anyInt(),
		anyInt(), anyBoolean())).thenReturn(true);
		// This is so that IBackupAgent.Stub.asInterface() works.
		when(mBackupAgentStub.queryLocalInterface(any())).thenReturn(mBackupAgentStub);
		when(mConnectionManager.getCallingUid()).thenReturn(Process.SYSTEM_UID);

		// This is going to block until it receives the callback so we need to run it on a
		// separate thread.
		Thread testThread = new Thread(() -> setBackupAgentResult(
		mConnectionManager.bindToAgentSynchronous(mTestApplicationInfo,
		ApplicationThreadConstants.BACKUP_MODE_FULL, BackupDestination.CLOUD)),
		"backup-agent-connection-manager-test");
		testThread.start();
		// Give the testThread a head start, otherwise agentConnected() might run before
		// bindToAgentSynchronous() is called.
		Thread.sleep(500);
		mConnectionManager.agentConnected("com.other.package", mBackupAgentStub);
		testThread.join(100); // Avoid waiting the full timeout.

		assertThat(mBackupAgentResult).isNull();
		}

		@Test
		@DisableFlags(Flags.FLAG_ENABLE_RESTRICTED_MODE_CHANGES)
		public void bindToAgentSynchronous_restrictedModeChangesFlagOff_shouldUseRestrictedMode()
		@@ -345,6 +370,7 @@ public class BackupAgentConnectionManagerTest {

		@Test
		public void agentDisconnected_cancelsCurrentOperations() throws Exception {
		when(mConnectionManager.getCallingUid()).thenReturn(Process.SYSTEM_UID);
		when(mOperationStorage.operationTokensForPackage(eq(TEST_PACKAGE))).thenReturn(
		ImmutableSet.of(123, 456, 789));
		when(mConnectionManager.getThreadForCancellation(any())).thenAnswer(invocation -> {