| /* |
| * Copyright (C) 2020 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.google.android.connecteddevice.connection.ble; |
| |
| import static com.google.android.connecteddevice.model.Errors.DEVICE_ERROR_UNEXPECTED_DISCONNECTION; |
| import static com.google.android.connecteddevice.util.SafeLog.logd; |
| import static com.google.android.connecteddevice.util.SafeLog.loge; |
| import static com.google.android.connecteddevice.util.SafeLog.logw; |
| |
| import android.bluetooth.BluetoothDevice; |
| import android.bluetooth.BluetoothGattCharacteristic; |
| import android.bluetooth.BluetoothGattDescriptor; |
| import android.bluetooth.BluetoothGattService; |
| import android.bluetooth.le.AdvertiseCallback; |
| import android.bluetooth.le.AdvertiseData; |
| import android.bluetooth.le.AdvertiseSettings; |
| import android.os.Handler; |
| import android.os.HandlerThread; |
| import android.os.ParcelUuid; |
| import androidx.annotation.NonNull; |
| import androidx.annotation.Nullable; |
| import androidx.annotation.VisibleForTesting; |
| import com.google.android.connecteddevice.connection.AssociationCallback; |
| import com.google.android.connecteddevice.connection.AssociationSecureChannel; |
| import com.google.android.connecteddevice.connection.CarBluetoothManager; |
| import com.google.android.connecteddevice.connection.ConnectionResolver; |
| import com.google.android.connecteddevice.connection.DeviceMessageStream; |
| import com.google.android.connecteddevice.connection.ReconnectSecureChannel; |
| import com.google.android.connecteddevice.model.OobData; |
| import com.google.android.connecteddevice.model.StartAssociationResponse; |
| import com.google.android.connecteddevice.oob.OobChannel; |
| import com.google.android.connecteddevice.storage.ConnectedDeviceStorage; |
| import com.google.android.connecteddevice.transport.ble.BlePeripheralManager; |
| import com.google.android.connecteddevice.util.ByteUtils; |
| import com.google.android.connecteddevice.util.EventLog; |
| import java.time.Duration; |
| import java.util.Arrays; |
| import java.util.UUID; |
| import java.util.concurrent.Future; |
| |
| /** Communication manager that allows for targeted connections to a specific device in the car. */ |
| public class CarBlePeripheralManager extends CarBluetoothManager { |
| |
| private static final String TAG = "CarBlePeripheralManager"; |
| |
| // Attribute protocol bytes attached to message. Available write size is MTU size minus att |
| // bytes. |
| private static final int ATT_PROTOCOL_BYTES = 3; |
| |
| private static final UUID CLIENT_CHARACTERISTIC_CONFIG = |
| UUID.fromString("00002902-0000-1000-8000-00805f9b34fb"); |
| |
| private static final int SALT_BYTES = 8; |
| |
| private static final int TOTAL_AD_DATA_BYTES = 16; |
| |
| private static final int TRUNCATED_BYTES = 3; |
| |
| private static final String TIMEOUT_HANDLER_THREAD_NAME = "peripheralThread"; |
| |
| private final BlePeripheralManager blePeripheralManager; |
| |
| private final UUID associationServiceUuid; |
| |
| private final UUID reconnectServiceUuid; |
| |
| private final UUID reconnectDataUuid; |
| |
| private final BluetoothGattCharacteristic writeCharacteristic; |
| |
| @VisibleForTesting final BluetoothGattCharacteristic readCharacteristic; |
| |
| private final BluetoothGattCharacteristic advertiseDataCharacteristic; |
| |
| private HandlerThread timeoutHandlerThread; |
| |
| private Handler timeoutHandler; |
| |
| private final Duration maxReconnectAdvertisementDuration; |
| |
| private final int defaultMtuSize; |
| |
| private String reconnectDeviceId; |
| |
| private byte[] reconnectChallenge; |
| |
| private AdvertiseCallback advertiseCallback; |
| |
| private Future<?> bluetoothNameTask; |
| |
| public CarBlePeripheralManager( |
| @NonNull BlePeripheralManager blePeripheralManager, |
| @NonNull ConnectedDeviceStorage connectedDeviceStorage, |
| @NonNull UUID associationServiceUuid, |
| @NonNull UUID reconnectServiceUuid, |
| @NonNull UUID reconnectDataUuid, |
| @NonNull UUID advertiseDataCharacteristicUuid, |
| @NonNull UUID writeCharacteristicUuid, |
| @NonNull UUID readCharacteristicUuid, |
| @NonNull Duration maxReconnectAdvertisementDuration, |
| int defaultMtuSize, |
| boolean enableCompression, |
| boolean isCapabilitiesEligible) { |
| this( |
| blePeripheralManager, |
| connectedDeviceStorage, |
| associationServiceUuid, |
| reconnectServiceUuid, |
| reconnectDataUuid, |
| advertiseDataCharacteristicUuid, |
| writeCharacteristicUuid, |
| readCharacteristicUuid, |
| maxReconnectAdvertisementDuration, |
| defaultMtuSize, |
| enableCompression, |
| /* oobChannel= */ null, |
| isCapabilitiesEligible); |
| } |
| |
| /** |
| * Initialize a new instance of manager. |
| * |
| * @param blePeripheralManager {@link BlePeripheralManager} for establishing connection. |
| * @param connectedDeviceStorage Shared {@link ConnectedDeviceStorage} for companion features. |
| * @param associationServiceUuid {@link UUID} of association service. |
| * @param reconnectServiceUuid {@link UUID} of reconnect service. |
| * @param reconnectDataUuid {@link UUID} key of reconnect advertisement data. |
| * @param advertiseDataCharacteristicUuid {@link UUID} of characteristic that contains advertise |
| * data. |
| * @param writeCharacteristicUuid {@link UUID} of characteristic the car will write to. |
| * @param readCharacteristicUuid {@link UUID} of characteristic the device will write to. |
| * @param maxReconnectAdvertisementDuration Maximum duration to advertise for reconnect before |
| * restarting. |
| * @param defaultMtuSize Default MTU size for new channels. |
| * @param enableCompression Enable compression on outgoing messages. |
| * @param oobChannel Channel for exchanging out of band verification. |
| * @param isCapabilitiesEligible Association should attempt a capabilities exchange. |
| */ |
| public CarBlePeripheralManager( |
| @NonNull BlePeripheralManager blePeripheralManager, |
| @NonNull ConnectedDeviceStorage connectedDeviceStorage, |
| @NonNull UUID associationServiceUuid, |
| @NonNull UUID reconnectServiceUuid, |
| @NonNull UUID reconnectDataUuid, |
| @NonNull UUID advertiseDataCharacteristicUuid, |
| @NonNull UUID writeCharacteristicUuid, |
| @NonNull UUID readCharacteristicUuid, |
| @NonNull Duration maxReconnectAdvertisementDuration, |
| int defaultMtuSize, |
| boolean enableCompression, |
| @Nullable OobChannel oobChannel, |
| boolean isCapabilitiesEligible) { |
| super(connectedDeviceStorage, enableCompression, oobChannel, isCapabilitiesEligible); |
| this.blePeripheralManager = blePeripheralManager; |
| this.associationServiceUuid = associationServiceUuid; |
| this.reconnectServiceUuid = reconnectServiceUuid; |
| this.reconnectDataUuid = reconnectDataUuid; |
| writeCharacteristic = |
| new BluetoothGattCharacteristic( |
| writeCharacteristicUuid, |
| BluetoothGattCharacteristic.PROPERTY_NOTIFY | BluetoothGattCharacteristic.PROPERTY_READ, |
| BluetoothGattCharacteristic.PERMISSION_READ); |
| writeCharacteristic.addDescriptor(createBluetoothGattDescriptor()); |
| |
| readCharacteristic = |
| new BluetoothGattCharacteristic( |
| readCharacteristicUuid, |
| BluetoothGattCharacteristic.PROPERTY_WRITE |
| | BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE, |
| BluetoothGattCharacteristic.PERMISSION_WRITE); |
| readCharacteristic.addDescriptor(createBluetoothGattDescriptor()); |
| |
| advertiseDataCharacteristic = |
| new BluetoothGattCharacteristic( |
| advertiseDataCharacteristicUuid, |
| BluetoothGattCharacteristic.PROPERTY_NOTIFY | BluetoothGattCharacteristic.PROPERTY_READ, |
| BluetoothGattCharacteristic.PERMISSION_READ); |
| advertiseDataCharacteristic.addDescriptor(createBluetoothGattDescriptor()); |
| |
| this.maxReconnectAdvertisementDuration = maxReconnectAdvertisementDuration; |
| this.defaultMtuSize = defaultMtuSize; |
| } |
| |
| private BluetoothGattDescriptor createBluetoothGattDescriptor() { |
| BluetoothGattDescriptor descriptor = |
| new BluetoothGattDescriptor( |
| CLIENT_CHARACTERISTIC_CONFIG, |
| BluetoothGattDescriptor.PERMISSION_READ | BluetoothGattDescriptor.PERMISSION_WRITE); |
| descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE); |
| return descriptor; |
| } |
| |
| @Override |
| public void start() { |
| super.start(); |
| timeoutHandlerThread = new HandlerThread(TIMEOUT_HANDLER_THREAD_NAME); |
| timeoutHandlerThread.start(); |
| timeoutHandler = new Handler(timeoutHandlerThread.getLooper()); |
| } |
| |
| @Override |
| public void stop() { |
| super.stop(); |
| if (timeoutHandlerThread != null) { |
| timeoutHandlerThread.quit(); |
| } |
| reset(); |
| } |
| |
| @Override |
| public void disconnectDevice(@NonNull String deviceId) { |
| if (deviceId.equals(reconnectDeviceId)) { |
| logd(TAG, "Reconnection canceled for device " + deviceId + "."); |
| reset(); |
| return; |
| } |
| ConnectedRemoteDevice connectedDevice = getConnectedDevice(); |
| if (connectedDevice == null || !deviceId.equals(connectedDevice.deviceId)) { |
| return; |
| } |
| reset(); |
| } |
| |
| @Override |
| public void reset() { |
| super.reset(); |
| logd(TAG, "Resetting state."); |
| if (timeoutHandler != null) { |
| timeoutHandler.removeCallbacks(timeoutRunnable); |
| } |
| blePeripheralManager.cleanup(); |
| reconnectDeviceId = null; |
| reconnectChallenge = null; |
| if (bluetoothNameTask != null) { |
| bluetoothNameTask.cancel(true); |
| } |
| bluetoothNameTask = null; |
| } |
| |
| @Override |
| public void initiateConnectionToDevice(@NonNull UUID deviceId) { |
| reconnectDeviceId = deviceId.toString(); |
| advertiseCallback = |
| new AdvertiseCallback() { |
| @Override |
| public void onStartSuccess(AdvertiseSettings settingsInEffect) { |
| super.onStartSuccess(settingsInEffect); |
| timeoutHandler.postDelayed( |
| timeoutRunnable, maxReconnectAdvertisementDuration.toMillis()); |
| logd(TAG, "Successfully started advertising for device " + deviceId + "."); |
| } |
| }; |
| blePeripheralManager.unregisterCallback(associationPeripheralCallback); |
| blePeripheralManager.registerCallback(reconnectPeripheralCallback); |
| timeoutHandler.removeCallbacks(timeoutRunnable); |
| byte[] advertiseData = createReconnectData(reconnectDeviceId); |
| if (advertiseData == null) { |
| loge(TAG, "Unable to create advertisement data. Aborting reconnect."); |
| return; |
| } |
| startAdvertising( |
| reconnectServiceUuid, |
| advertiseCallback, |
| advertiseData, |
| reconnectDataUuid, |
| /* scanResponse= */ null, |
| /* scanResponseUuid= */ null); |
| } |
| |
| /** |
| * Create data for reconnection advertisement. |
| * |
| * <p> |
| * |
| * <p>Process: |
| * |
| * <ol> |
| * <li>Generate random {@value SALT_BYTES} byte salt and zero-pad to {@value |
| * TOTAL_AD_DATA_BYTES} bytes. |
| * <li>Hash with stored challenge secret and truncate to {@value TRUNCATED_BYTES} bytes. |
| * <li>Concatenate hashed {@value TRUNCATED_BYTES} bytes with salt and return. |
| * </ol> |
| */ |
| @Nullable |
| private byte[] createReconnectData(String deviceId) { |
| byte[] salt = ByteUtils.randomBytes(SALT_BYTES); |
| byte[] zeroPadded = |
| ByteUtils.concatByteArrays(salt, new byte[TOTAL_AD_DATA_BYTES - SALT_BYTES]); |
| reconnectChallenge = storage.hashWithChallengeSecret(deviceId, zeroPadded); |
| if (reconnectChallenge == null) { |
| return null; |
| } |
| return ByteUtils.concatByteArrays(Arrays.copyOf(reconnectChallenge, TRUNCATED_BYTES), salt); |
| } |
| |
| @Override |
| public void startAssociation( |
| @NonNull byte[] nameForAssociation, @NonNull AssociationCallback callback) { |
| reset(); |
| setAssociationCallback(callback); |
| blePeripheralManager.unregisterCallback(reconnectPeripheralCallback); |
| blePeripheralManager.registerCallback(associationPeripheralCallback); |
| advertiseCallback = |
| new AdvertiseCallback() { |
| @Override |
| public void onStartSuccess(AdvertiseSettings settingsInEffect) { |
| super.onStartSuccess(settingsInEffect); |
| callback.onAssociationStartSuccess( |
| new StartAssociationResponse( |
| /* oobData= */ new OobData(new byte[0], new byte[0], new byte[0]), |
| nameForAssociation, |
| ByteUtils.byteArrayToHexString(nameForAssociation))); |
| logd(TAG, "Successfully started advertising for association."); |
| } |
| |
| @Override |
| public void onStartFailure(int errorCode) { |
| super.onStartFailure(errorCode); |
| callback.onAssociationStartFailure(); |
| logd(TAG, "Failed to start advertising for association. Error code: " + errorCode); |
| } |
| }; |
| |
| startAdvertising( |
| associationServiceUuid, |
| advertiseCallback, |
| /* advertiseData= */ null, |
| /* advertiseDataUuid= */ null, |
| nameForAssociation, |
| reconnectDataUuid); |
| } |
| |
| /** Set the timeout handler for testing. This should be called after {@link #start()}. */ |
| @VisibleForTesting |
| void setTimeoutHandler(Handler handler) { |
| timeoutHandler = handler; |
| } |
| |
| private void startAdvertising( |
| @NonNull UUID serviceUuid, |
| @NonNull AdvertiseCallback callback, |
| @Nullable byte[] advertiseData, |
| @Nullable UUID advertiseDataUuid, |
| @Nullable byte[] scanResponse, |
| @Nullable UUID scanResponseUuid) { |
| BluetoothGattService gattService = |
| new BluetoothGattService(serviceUuid, BluetoothGattService.SERVICE_TYPE_PRIMARY); |
| gattService.addCharacteristic(writeCharacteristic); |
| gattService.addCharacteristic(readCharacteristic); |
| |
| AdvertiseData.Builder advertisementBuilder = new AdvertiseData.Builder(); |
| ParcelUuid uuid = new ParcelUuid(serviceUuid); |
| advertisementBuilder.addServiceUuid(uuid); |
| if (advertiseData != null) { |
| ParcelUuid dataUuid = uuid; |
| if (advertiseDataUuid != null) { |
| dataUuid = new ParcelUuid(advertiseDataUuid); |
| } |
| advertisementBuilder.addServiceData(dataUuid, advertiseData); |
| |
| // Also embed the advertise data into a fixed GATT service characteristic. |
| advertiseDataCharacteristic.setValue(advertiseData); |
| gattService.addCharacteristic(advertiseDataCharacteristic); |
| } |
| |
| AdvertiseData.Builder scanResponseBuilder = new AdvertiseData.Builder(); |
| if (scanResponse != null && scanResponseUuid != null) { |
| ParcelUuid scanResponseParcelUuid = new ParcelUuid(scanResponseUuid); |
| scanResponseBuilder.addServiceData(scanResponseParcelUuid, scanResponse); |
| } |
| |
| blePeripheralManager.startAdvertising( |
| gattService, advertisementBuilder.build(), scanResponseBuilder.build(), callback); |
| } |
| |
| private void addConnectedDevice(BluetoothDevice device, boolean isReconnect) { |
| EventLog.onDeviceConnected(); |
| blePeripheralManager.stopAdvertising(advertiseCallback); |
| if (timeoutHandler != null) { |
| timeoutHandler.removeCallbacks(timeoutRunnable); |
| } |
| |
| setClientDeviceAddress(device.getAddress()); |
| |
| DeviceMessageStream secureStream = |
| new BleDeviceMessageStream( |
| blePeripheralManager, |
| device, |
| writeCharacteristic, |
| readCharacteristic, |
| defaultMtuSize - ATT_PROTOCOL_BYTES); |
| |
| secureStream.setMessageReceivedErrorListener( |
| exception -> |
| disconnectWithError("Error occurred in stream: " + exception.getMessage(), exception)); |
| |
| ConnectedRemoteDevice connectedDevice = new ConnectedRemoteDevice(device, /* gatt= */ null); |
| |
| if (isReconnect) { |
| // Capabilities are only exchanged during association so isCapabilitiesEligible is always |
| // false here. |
| ConnectionResolver connectionResolver = |
| new ConnectionResolver(secureStream, /* isCapabilitiesEligible= */ false); |
| connectionResolver.resolveConnection( |
| (resolvedConnection) -> { |
| ReconnectSecureChannel secureChannel = |
| new ReconnectSecureChannel( |
| secureStream, storage, reconnectDeviceId, reconnectChallenge); |
| secureChannel.registerCallback(secureChannelCallback); |
| connectedDevice.secureChannel = secureChannel; |
| addConnectedDevice(connectedDevice); |
| setDeviceIdAndNotifyCallbacks(reconnectDeviceId); |
| reconnectDeviceId = null; |
| reconnectChallenge = null; |
| }); |
| } else { |
| onDeviceConnectedForAssociation(secureStream, connectedDevice); |
| } |
| } |
| |
| private void setMtuSize(int mtuSize) { |
| ConnectedRemoteDevice connectedDevice = getConnectedDevice(); |
| if (connectedDevice != null |
| && connectedDevice.secureChannel != null) { |
| connectedDevice.secureChannel.getStream().setMaxWriteSize(mtuSize - ATT_PROTOCOL_BYTES); |
| } |
| } |
| |
| private final BlePeripheralManager.Callback reconnectPeripheralCallback = |
| new BlePeripheralManager.Callback() { |
| @Override |
| public void onMtuSizeChanged(int size) { |
| setMtuSize(size); |
| } |
| |
| @Override |
| public void onRemoteDeviceConnected(BluetoothDevice device) { |
| addConnectedDevice(device, /* isReconnect= */ true); |
| } |
| |
| @Override |
| public void onRemoteDeviceDisconnected(BluetoothDevice device) { |
| String deviceId = reconnectDeviceId; |
| ConnectedRemoteDevice connectedDevice = getConnectedDevice(device); |
| // Reset before invoking callbacks to avoid a race condition with reconnect |
| // logic. |
| reset(); |
| if (connectedDevice != null) { |
| deviceId = connectedDevice.deviceId; |
| } |
| final String finalDeviceId = deviceId; |
| if (finalDeviceId == null) { |
| logw( |
| TAG, |
| "Callbacks were not issued for disconnect because the device id " + "was null."); |
| return; |
| } |
| logd(TAG, "Connected device " + finalDeviceId + " disconnected."); |
| callbacks.invoke(callback -> callback.onDeviceDisconnected(finalDeviceId)); |
| } |
| }; |
| |
| private final BlePeripheralManager.Callback associationPeripheralCallback = |
| new BlePeripheralManager.Callback() { |
| @Override |
| public void onMtuSizeChanged(int size) { |
| setMtuSize(size); |
| } |
| |
| @Override |
| public void onRemoteDeviceConnected(BluetoothDevice device) { |
| addConnectedDevice(device, /* isReconnect= */ false); |
| ConnectedRemoteDevice connectedDevice = getConnectedDevice(); |
| if (connectedDevice == null || connectedDevice.secureChannel == null) { |
| return; |
| } |
| ((AssociationSecureChannel) connectedDevice.secureChannel) |
| .setShowVerificationCodeListener( |
| CarBlePeripheralManager.this::onVerificationCodeAvailable); |
| } |
| |
| @Override |
| public void onRemoteDeviceDisconnected(BluetoothDevice device) { |
| logd(TAG, "Remote device disconnected."); |
| ConnectedRemoteDevice connectedDevice = getConnectedDevice(device); |
| if (isAssociating()) { |
| getAssociationCallback().onAssociationError(DEVICE_ERROR_UNEXPECTED_DISCONNECTION); |
| } |
| // Reset before invoking callbacks to avoid a race condition with reconnect |
| // logic. |
| reset(); |
| if (connectedDevice == null || connectedDevice.deviceId == null) { |
| logw(TAG, "Callbacks were not issued for disconnect."); |
| return; |
| } |
| callbacks.invoke(callback -> callback.onDeviceDisconnected(connectedDevice.deviceId)); |
| } |
| }; |
| |
| private final Runnable timeoutRunnable = |
| new Runnable() { |
| @Override |
| public void run() { |
| logd(TAG, "Timeout period expired without a connection. Restarting advertisement."); |
| blePeripheralManager.stopAdvertising(advertiseCallback); |
| connectToDevice(UUID.fromString(reconnectDeviceId)); |
| } |
| }; |
| } |
