[CDM][V] Implement backup and restore APIs. (225365c8) · Commits · e / os / android_frameworks_base

core/java/android/companion/AssociationInfo.java

+23 −0

Original line number	Diff line number	Diff line
		@@ -458,6 +458,29 @@ public final class AssociationInfo implements Parcelable {
		mSystemDataSyncFlags = info.mSystemDataSyncFlags;
		}

		/**
		* This builder is used specifically to create a new association to be restored to a device
		* that is potentially using a different user ID from the backed-up device.
		*
		* @hide
		*/
		public Builder(int id, int userId, @NonNull String packageName, AssociationInfo info) {
		mId = id;
		mUserId = userId;
		mPackageName = packageName;
		mTag = info.mTag;
		mDeviceMacAddress = info.mDeviceMacAddress;
		mDisplayName = info.mDisplayName;
		mDeviceProfile = info.mDeviceProfile;
		mAssociatedDevice = info.mAssociatedDevice;
		mSelfManaged = info.mSelfManaged;
		mNotifyOnDeviceNearby = info.mNotifyOnDeviceNearby;
		mRevoked = info.mRevoked;
		mTimeApprovedMs = info.mTimeApprovedMs;
		mLastTimeConnectedMs = info.mLastTimeConnectedMs;
		mSystemDataSyncFlags = info.mSystemDataSyncFlags;
		}

		/** @hide */
		@FlaggedApi(Flags.FLAG_ASSOCIATION_TAG)
		@TestApi

core/java/android/companion/datatransfer/PermissionSyncRequest.java

+9 −0

Original line number	Diff line number	Diff line
		@@ -47,6 +47,15 @@ public class PermissionSyncRequest extends SystemDataTransferRequest implements
		super(in);
		}

		/** @hide */
		@Override
		public PermissionSyncRequest copyWithNewId(int associationId) {
		PermissionSyncRequest newRequest = new PermissionSyncRequest(associationId);
		newRequest.mUserId = this.mUserId;
		newRequest.mUserConsented = this.mUserConsented;
		return newRequest;
		}

		/** @hide */
		@NonNull
		public static final Creator<PermissionSyncRequest> CREATOR =

core/java/android/companion/datatransfer/SystemDataTransferRequest.java

+11 −0

Original line number	Diff line number	Diff line
		@@ -103,4 +103,15 @@ public abstract class SystemDataTransferRequest {
		public int describeContents() {
		return 0;
		}

		/**
		* Creates a copy of itself with new association ID.
		*
		* This method must be implemented to ensure that backup-and-restore can correctly re-map
		* the restored requests to the restored associations that can potentially have different
		* IDs than what was originally backed up.
		*
		* @hide
		*/
		public abstract SystemDataTransferRequest copyWithNewId(int associationId);
		}

services/companion/java/com/android/server/companion/BackupRestoreProcessor.java

0 → 100644

+241 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2024 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 com.android.server.companion;

		import static android.os.UserHandle.getCallingUserId;

		import android.annotation.NonNull;
		import android.annotation.SuppressLint;
		import android.annotation.UserIdInt;
		import android.companion.AssociationInfo;
		import android.companion.Flags;
		import android.companion.datatransfer.SystemDataTransferRequest;
		import android.content.pm.ApplicationInfo;
		import android.content.pm.PackageManagerInternal;
		import android.util.Log;
		import android.util.Slog;

		import com.android.internal.util.CollectionUtils;
		import com.android.server.companion.datatransfer.SystemDataTransferRequestStore;

		import java.nio.ByteBuffer;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.List;
		import java.util.Objects;
		import java.util.Set;
		import java.util.function.Predicate;

		@SuppressLint("LongLogTag")
		class BackupRestoreProcessor {
		static final String TAG = "CDM_BackupRestoreProcessor";
		private static final int BACKUP_AND_RESTORE_VERSION = 0;

		@NonNull
		private final CompanionDeviceManagerService mService;
		@NonNull
		private final PackageManagerInternal mPackageManager;
		@NonNull
		private final AssociationStoreImpl mAssociationStore;
		@NonNull
		private final PersistentDataStore mPersistentStore;
		@NonNull
		private final SystemDataTransferRequestStore mSystemDataTransferRequestStore;
		@NonNull
		private final AssociationRequestsProcessor mAssociationRequestsProcessor;

		BackupRestoreProcessor(@NonNull CompanionDeviceManagerService service,
		@NonNull AssociationStoreImpl associationStore,
		@NonNull PersistentDataStore persistentStore,
		@NonNull SystemDataTransferRequestStore systemDataTransferRequestStore,
		@NonNull AssociationRequestsProcessor associationRequestsProcessor) {
		mService = service;
		mPackageManager = service.mPackageManagerInternal;
		mAssociationStore = associationStore;
		mPersistentStore = persistentStore;
		mSystemDataTransferRequestStore = systemDataTransferRequestStore;
		mAssociationRequestsProcessor = associationRequestsProcessor;
		}

		/**
		* Generate CDM state payload to be backed up.
		* Backup payload is formatted as following:
		* \| (4) payload version \| (4) AssociationInfo length \| AssociationInfo XML
		* \| (4) SystemDataTransferRequest length \| SystemDataTransferRequest XML (without userId)\|
		*/
		byte[] getBackupPayload(int userId) {
		// Persist state first to generate an up-to-date XML file
		mService.persistStateForUser(userId);
		byte[] associationsPayload = mPersistentStore.getBackupPayload(userId);
		int associationsPayloadLength = associationsPayload.length;

		// System data transfer requests are persisted up-to-date already
		byte[] requestsPayload = mSystemDataTransferRequestStore.getBackupPayload(userId);
		int requestsPayloadLength = requestsPayload.length;

		int payloadSize = /* 3 integers */ 12
		+ associationsPayloadLength
		+ requestsPayloadLength;

		return ByteBuffer.allocate(payloadSize)
		.putInt(BACKUP_AND_RESTORE_VERSION)
		.putInt(associationsPayloadLength)
		.put(associationsPayload)
		.putInt(requestsPayloadLength)
		.put(requestsPayload)
		.array();
		}

		/**
		* Create new associations and system data transfer request consents using backed up payload.
		*/
		void applyRestoredPayload(byte[] payload, int userId) {
		ByteBuffer buffer = ByteBuffer.wrap(payload);

		// Make sure that payload version matches current version to ensure proper deserialization
		int version = buffer.getInt();
		if (version != BACKUP_AND_RESTORE_VERSION) {
		Slog.e(TAG, "Unsupported backup payload version");
		return;
		}

		// Read the bytes containing backed-up associations
		byte[] associationsPayload = new byte[buffer.getInt()];
		buffer.get(associationsPayload);
		final Set<AssociationInfo> restoredAssociations = new HashSet<>();
		mPersistentStore.readStateFromPayload(associationsPayload, userId,
		restoredAssociations, new HashMap<>());

		// Read the bytes containing backed-up system data transfer requests user consent
		byte[] requestsPayload = new byte[buffer.getInt()];
		buffer.get(requestsPayload);
		List<SystemDataTransferRequest> restoredRequestsForUser =
		mSystemDataTransferRequestStore.readRequestsFromPayload(requestsPayload);

		// Get a list of installed packages ahead of time.
		List<ApplicationInfo> installedApps = mPackageManager.getInstalledApplications(
		0, userId, getCallingUserId());

		// Restored device may have a different user ID than the backed-up user's user-ID. Since
		// association ID is dependent on the user ID, restored associations must account for
		// this potential difference on their association IDs.
		for (AssociationInfo restored : restoredAssociations) {
		// Don't restore a revoked association. Since they weren't added to the device being
		// restored in the first place, there is no need to worry about revoking a role that
		// was never granted either.
		if (restored.isRevoked()) {
		continue;
		}

		// Filter restored requests for those that belong to the restored association.
		List<SystemDataTransferRequest> restoredRequests = CollectionUtils.filter(
		restoredRequestsForUser, it -> it.getAssociationId() == restored.getId());

		// Handle collision: If a local association belonging to the same package already exists
		// and their tags match, then keep the local one in favor of creating a new association.
		if (handleCollision(userId, restored, restoredRequests)) {
		continue;
		}

		// Create a new association reassigned to this user and a valid association ID
		final String packageName = restored.getPackageName();
		final int newId = mService.getNewAssociationIdForPackage(userId, packageName);
		AssociationInfo newAssociation =
		new AssociationInfo.Builder(newId, userId, packageName, restored)
		.build();

		// Check if the companion app for this association is already installed, then do one
		// of the following:
		// (1) If the app is already installed, then go ahead and add this association and grant
		// the role attached to this association to the app.
		// (2) If the app isn't yet installed, then add this association to the list of pending
		// associations to be added when the package is installed in the future.
		boolean isPackageInstalled = installedApps.stream()
		.anyMatch(app -> packageName.equals(app.packageName));
		if (isPackageInstalled) {
		mAssociationRequestsProcessor.maybeGrantRoleAndStoreAssociation(newAssociation,
		null, null);
		} else {
		// TODO(b/314992577): Check if package is installed before granting
		}

		// Re-map restored system data transfer requests to newly created associations
		for (SystemDataTransferRequest restoredRequest : restoredRequests) {
		SystemDataTransferRequest newRequest = restoredRequest.copyWithNewId(newId);
		newRequest.setUserId(userId);
		mSystemDataTransferRequestStore.writeRequest(userId, newRequest);
		}
		}

		// Persist restored state.
		mService.persistStateForUser(userId);
		}

		/**
		* Detects and handles collision between restored association and local association. Returns
		* true if there has been a collision and false otherwise.
		*/
		private boolean handleCollision(@UserIdInt int userId,
		AssociationInfo restored,
		List<SystemDataTransferRequest> restoredRequests) {
		List<AssociationInfo> localAssociations = mAssociationStore.getAssociationsForPackage(
		restored.getUserId(), restored.getPackageName());
		Predicate<AssociationInfo> isSameDevice = associationInfo -> {
		boolean matchesMacAddress = Objects.equals(
		associationInfo.getDeviceMacAddress(),
		restored.getDeviceMacAddress());
		boolean matchesTag = !Flags.associationTag()
		\|\| Objects.equals(associationInfo.getTag(), restored.getTag());
		return matchesMacAddress && matchesTag;
		};
		AssociationInfo local = CollectionUtils.find(localAssociations, isSameDevice);

		// No collision detected
		if (local == null) {
		return false;
		}

		Log.d(TAG, "Conflict detected with association id=" + local.getId()
		+ " while restoring CDM backup. Keeping local association.");

		List<SystemDataTransferRequest> localRequests = mSystemDataTransferRequestStore
		.readRequestsByAssociationId(userId, local.getId());

		// If local association doesn't have any existing system data transfer request of same type
		// attached, then restore corresponding request onto the local association. Otherwise, keep
		// the locally stored request.
		for (SystemDataTransferRequest restoredRequest : restoredRequests) {
		boolean requestTypeExists = CollectionUtils.any(localRequests, request ->
		request.getDataType() == restoredRequest.getDataType());

		// This type of request consent already exists for the association.
		if (requestTypeExists) {
		continue;
		}

		Log.d(TAG, "Restoring " + restoredRequest.getClass().getSimpleName()
		+ " to an existing association id=" + local.getId() + ".");

		SystemDataTransferRequest newRequest =
		restoredRequest.copyWithNewId(local.getId());
		newRequest.setUserId(userId);
		mSystemDataTransferRequestStore.writeRequest(userId, newRequest);
		}

		return true;
		}
		}

services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java

+21 −5

Original line number	Diff line number	Diff line
		@@ -164,6 +164,7 @@ public class CompanionDeviceManagerService extends SystemService {
		private final SystemDataTransferRequestStore mSystemDataTransferRequestStore;
		private AssociationRequestsProcessor mAssociationRequestsProcessor;
		private SystemDataTransferProcessor mSystemDataTransferProcessor;
		private BackupRestoreProcessor mBackupRestoreProcessor;
		private CompanionDevicePresenceMonitor mDevicePresenceMonitor;
		private CompanionApplicationController mCompanionAppController;
		private CompanionTransportManager mTransportManager;
		@@ -256,6 +257,9 @@ public class CompanionDeviceManagerService extends SystemService {
		mSystemDataTransferProcessor = new SystemDataTransferProcessor(this,
		mPackageManagerInternal, mAssociationStore,
		mSystemDataTransferRequestStore, mTransportManager);
		mBackupRestoreProcessor = new BackupRestoreProcessor(
		/* cdmService */ this, mAssociationStore, mPersistentStore,
		mSystemDataTransferRequestStore, mAssociationRequestsProcessor);
		// TODO(b/279663946): move context sync to a dedicated system service
		mCrossDeviceSyncController = new CrossDeviceSyncController(getContext(), mTransportManager);

		@@ -501,7 +505,7 @@ public class CompanionDeviceManagerService extends SystemService {
		updateAtm(userId, updatedAssociations);
		}

		private void persistStateForUser(@UserIdInt int userId) {
		void persistStateForUser(@UserIdInt int userId) {
		// We want to store both active associations and the revoked (removed) association that we
		// are keeping around for the final clean-up (delayed role holder removal).
		final List<AssociationInfo> allAssociations;
		@@ -577,6 +581,11 @@ public class CompanionDeviceManagerService extends SystemService {
		mCompanionAppController.onPackagesChanged(userId);
		}

		private void onPackageAddedInternal(@UserIdInt int userId, @NonNull String packageName) {
		if (DEBUG) Log.i(TAG, "onPackageAddedInternal() u" + userId + "/" + packageName);
		// TODO(b/314992577): Retroactively grant roles for restored associations
		}

		// Revoke associations if the selfManaged companion device does not connect for 3 months.
		void removeInactiveSelfManagedAssociations() {
		final long currentTime = System.currentTimeMillis();
		@@ -1052,13 +1061,14 @@ public class CompanionDeviceManagerService extends SystemService {

		@Override
		public byte[] getBackupPayload(int userId) {
		// TODO(b/286124853): back up CDM data
		return new byte[0];
		Log.i(TAG, "getBackupPayload() userId=" + userId);
		return mBackupRestoreProcessor.getBackupPayload(userId);
		}

		@Override
		public void applyRestoredPayload(byte[] payload, int userId) {
		// TODO(b/286124853): restore CDM data
		Log.i(TAG, "applyRestoredPayload() userId=" + userId);
		mBackupRestoreProcessor.applyRestoredPayload(payload, userId);
		}

		@Override
		@@ -1067,7 +1077,8 @@ public class CompanionDeviceManagerService extends SystemService {
		@NonNull String[] args) {
		return new CompanionDeviceShellCommand(CompanionDeviceManagerService.this,
		mAssociationStore, mDevicePresenceMonitor, mTransportManager,
		mSystemDataTransferProcessor, mAssociationRequestsProcessor)
		mSystemDataTransferProcessor, mAssociationRequestsProcessor,
		mBackupRestoreProcessor)
		.exec(this, in.getFileDescriptor(), out.getFileDescriptor(),
		err.getFileDescriptor(), args);
		}
		@@ -1499,6 +1510,11 @@ public class CompanionDeviceManagerService extends SystemService {
		public void onPackageModified(String packageName) {
		onPackageModifiedInternal(getChangingUserId(), packageName);
		}

		@Override
		public void onPackageAdded(String packageName, int uid) {
		onPackageAddedInternal(getChangingUserId(), packageName);
		}
		};

		static int getFirstAssociationIdForUser(@UserIdInt int userId) {