android-13.0.0_r83/s

/*
 * Copyright 2022 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.bluetooth.bas;

import static android.Manifest.permission.BLUETOOTH_CONNECT;

import static com.android.bluetooth.Utils.enforceBluetoothPrivilegedPermission;

import android.annotation.RequiresPermission;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.BluetoothUuid;
import android.bluetooth.IBluetoothBattery;
import android.content.AttributionSource;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.HandlerThread;
import android.os.ParcelUuid;
import android.sysprop.BluetoothProperties;
import android.util.Log;

import com.android.bluetooth.Utils;
import com.android.bluetooth.btservice.AdapterService;
import com.android.bluetooth.btservice.ProfileService;
import com.android.bluetooth.btservice.storage.DatabaseManager;
import com.android.internal.annotations.VisibleForTesting;
import com.android.modules.utils.SynchronousResultReceiver;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;

/**
 * A profile service that connects to the Battery service (BAS) of BLE devices
 */
public class BatteryService extends ProfileService {
    private static final boolean DBG = false;
    private static final String TAG = "BatteryService";

    // Timeout for state machine thread join, to prevent potential ANR.
    private static final int SM_THREAD_JOIN_TIMEOUT_MS = 1_000;

    private static final int MAX_BATTERY_STATE_MACHINES = 10;
    private static BatteryService sBatteryService;

    private AdapterService mAdapterService;
    private DatabaseManager mDatabaseManager;
    private HandlerThread mStateMachinesThread;
    private final Map<BluetoothDevice, BatteryStateMachine> mStateMachines = new HashMap<>();

    private BroadcastReceiver mBondStateChangedReceiver;

    public static boolean isEnabled() {
        return BluetoothProperties.isProfileBasClientEnabled().orElse(false);
    }

    @Override
    protected IProfileServiceBinder initBinder() {
        return new BluetoothBatteryBinder(this);
    }

    @Override
    protected void create() {
        if (DBG) {
            Log.d(TAG, "create()");
        }
    }

    @Override
    protected boolean start() {
        if (DBG) {
            Log.d(TAG, "start()");
        }
        if (sBatteryService != null) {
            throw new IllegalStateException("start() called twice");
        }

        mAdapterService = Objects.requireNonNull(AdapterService.getAdapterService(),
                "AdapterService cannot be null when BatteryService starts");
        mDatabaseManager = Objects.requireNonNull(mAdapterService.getDatabase(),
                "DatabaseManager cannot be null when BatteryService starts");

        mStateMachines.clear();
        mStateMachinesThread = new HandlerThread("BatteryService.StateMachines");
        mStateMachinesThread.start();

        // Setup broadcast receivers
        IntentFilter filter = new IntentFilter();
        filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        mBondStateChangedReceiver = new BondStateChangedReceiver();
        registerReceiver(mBondStateChangedReceiver, filter);

        setBatteryService(this);

        return true;
    }

    @Override
    protected boolean stop() {
        if (DBG) {
            Log.d(TAG, "stop()");
        }
        if (sBatteryService == null) {
            Log.w(TAG, "stop() called before start()");
            return true;
        }

        setBatteryService(null);
        // Unregister broadcast receivers
        unregisterReceiver(mBondStateChangedReceiver);
        mBondStateChangedReceiver = null;

        // Destroy state machines and stop handler thread
        synchronized (mStateMachines) {
            for (BatteryStateMachine sm : mStateMachines.values()) {
                sm.doQuit();
                sm.cleanup();
            }
            mStateMachines.clear();
        }


        if (mStateMachinesThread != null) {
            try {
                mStateMachinesThread.quitSafely();
                mStateMachinesThread.join(SM_THREAD_JOIN_TIMEOUT_MS);
                mStateMachinesThread = null;
            } catch (InterruptedException e) {
                // Do not rethrow as we are shutting down anyway
            }
        }

        mAdapterService = null;

        return true;
    }

    @Override
    protected void cleanup() {
        if (DBG) {
            Log.d(TAG, "cleanup()");
        }
    }

    /**
     * Gets the BatteryService instance
     */
    public static synchronized BatteryService getBatteryService() {
        if (sBatteryService == null) {
            Log.w(TAG, "getBatteryService(): service is NULL");
            return null;
        }

        if (!sBatteryService.isAvailable()) {
            Log.w(TAG, "getBatteryService(): service is not available");
            return null;
        }
        return sBatteryService;
    }

    private static synchronized void setBatteryService(BatteryService instance) {
        if (DBG) {
            Log.d(TAG, "setBatteryService(): set to: " + instance);
        }
        sBatteryService = instance;
    }

    /**
     * Connects to the battery service of the given device.
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    public boolean connect(BluetoothDevice device) {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        if (DBG) {
            Log.d(TAG, "connect(): " + device);
        }
        if (device == null) {
            Log.w(TAG, "Ignore connecting to null device");
            return false;
        }

        if (getConnectionPolicy(device) == BluetoothProfile.CONNECTION_POLICY_FORBIDDEN) {
            Log.w(TAG, "Cannot connect to " + device + " : policy forbidden");
            return false;
        }
        ParcelUuid[] featureUuids = mAdapterService.getRemoteUuids(device);
        if (!Utils.arrayContains(featureUuids, BluetoothUuid.BATTERY)) {
            Log.e(TAG, "Cannot connect to " + device
                    + " : Remote does not have Battery UUID");
            return false;
        }

        synchronized (mStateMachines) {
            BatteryStateMachine sm = getOrCreateStateMachine(device);
            if (sm == null) {
                Log.e(TAG, "Cannot connect to " + device + " : no state machine");
                return false;
            }
            sm.sendMessage(BatteryStateMachine.CONNECT);
        }

        return true;
    }

    /**
     * Disconnects from the battery service of the given device.
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    public boolean disconnect(BluetoothDevice device) {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        if (DBG) {
            Log.d(TAG, "disconnect(): " + device);
        }
        if (device == null) {
            Log.w(TAG, "Ignore disconnecting to null device");
            return false;
        }
        synchronized (mStateMachines) {
            BatteryStateMachine sm = getOrCreateStateMachine(device);
            if (sm != null) {
                sm.sendMessage(BatteryStateMachine.DISCONNECT);
            }
        }

        return true;
    }

    /**
     * Gets devices that battery service is connected.
     * @return
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    public List<BluetoothDevice> getConnectedDevices() {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        synchronized (mStateMachines) {
            List<BluetoothDevice> devices = new ArrayList<>();
            for (BatteryStateMachine sm : mStateMachines.values()) {
                if (sm.isConnected()) {
                    devices.add(sm.getDevice());
                }
            }
            return devices;
        }
    }

    /**
     * Check whether it can connect to a peer device.
     * The check considers a number of factors during the evaluation.
     *
     * @param device the peer device to connect to
     * @return true if connection is allowed, otherwise false
     */
    @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
    public boolean canConnect(BluetoothDevice device) {
        // Check connectionPolicy and accept or reject the connection.
        int connectionPolicy = getConnectionPolicy(device);
        int bondState = mAdapterService.getBondState(device);
        // Allow this connection only if the device is bonded. Any attempt to connect while
        // bonding would potentially lead to an unauthorized connection.
        if (bondState != BluetoothDevice.BOND_BONDED) {
            Log.w(TAG, "canConnect: return false, bondState=" + bondState);
            return false;
        } else if (connectionPolicy != BluetoothProfile.CONNECTION_POLICY_UNKNOWN
                && connectionPolicy != BluetoothProfile.CONNECTION_POLICY_ALLOWED) {
            // Otherwise, reject the connection if connectionPolicy is not valid.
            Log.w(TAG, "canConnect: return false, connectionPolicy=" + connectionPolicy);
            return false;
        }
        return true;
    }

    /**
     * Called when the connection state of a state machine is changed
     */
    @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
    public void handleConnectionStateChanged(BatteryStateMachine sm,
            int fromState, int toState) {
        BluetoothDevice device = sm.getDevice();
        if ((sm == null) || (fromState == toState)) {
            Log.e(TAG, "connectionStateChanged: unexpected invocation. device=" + device
                    + " fromState=" + fromState + " toState=" + toState);
            return;
        }

        // Check if the device is disconnected - if unbonded, remove the state machine
        if (toState == BluetoothProfile.STATE_DISCONNECTED) {
            int bondState = mAdapterService.getBondState(device);
            if (bondState == BluetoothDevice.BOND_NONE) {
                if (DBG) {
                    Log.d(TAG, device + " is unbonded. Remove state machine");
                }
                removeStateMachine(device);
            }
        }
    }

    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    List<BluetoothDevice> getDevicesMatchingConnectionStates(int[] states) {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        ArrayList<BluetoothDevice> devices = new ArrayList<>();
        if (states == null) {
            return devices;
        }
        final BluetoothDevice[] bondedDevices = mAdapterService.getBondedDevices();
        if (bondedDevices == null) {
            return devices;
        }
        synchronized (mStateMachines) {
            for (BluetoothDevice device : bondedDevices) {
                int connectionState = BluetoothProfile.STATE_DISCONNECTED;
                BatteryStateMachine sm = mStateMachines.get(device);
                if (sm != null) {
                    connectionState = sm.getConnectionState();
                }
                for (int state : states) {
                    if (connectionState == state) {
                        devices.add(device);
                        break;
                    }
                }
            }
            return devices;
        }
    }

    /**
     * Get the list of devices that have state machines.
     *
     * @return the list of devices that have state machines
     */
    @VisibleForTesting
    List<BluetoothDevice> getDevices() {
        List<BluetoothDevice> devices = new ArrayList<>();
        synchronized (mStateMachines) {
            for (BatteryStateMachine sm : mStateMachines.values()) {
                devices.add(sm.getDevice());
            }
            return devices;
        }
    }

    /**
     * Gets the connection state of the given device's battery service
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
    public int getConnectionState(BluetoothDevice device) {
        enforceCallingOrSelfPermission(BLUETOOTH_CONNECT,
                "Need BLUETOOTH_CONNECT permission");
        synchronized (mStateMachines) {
            BatteryStateMachine sm = mStateMachines.get(device);
            if (sm == null) {
                return BluetoothProfile.STATE_DISCONNECTED;
            }
            return sm.getConnectionState();
        }
    }

    /**
     * Set connection policy of the profile and connects it if connectionPolicy is
     * {@link BluetoothProfile#CONNECTION_POLICY_ALLOWED} or disconnects if connectionPolicy is
     * {@link BluetoothProfile#CONNECTION_POLICY_FORBIDDEN}
     *
     * <p> The device should already be paired.
     * Connection policy can be one of:
     * {@link BluetoothProfile#CONNECTION_POLICY_ALLOWED},
     * {@link BluetoothProfile#CONNECTION_POLICY_FORBIDDEN},
     * {@link BluetoothProfile#CONNECTION_POLICY_UNKNOWN}
     *
     * @param device the remote device
     * @param connectionPolicy is the connection policy to set to for this profile
     * @return true on success, otherwise false
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    public boolean setConnectionPolicy(BluetoothDevice device, int connectionPolicy) {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        if (DBG) {
            Log.d(TAG, "Saved connectionPolicy " + device + " = " + connectionPolicy);
        }
        mDatabaseManager.setProfileConnectionPolicy(device, BluetoothProfile.BATTERY,
                        connectionPolicy);
        if (connectionPolicy == BluetoothProfile.CONNECTION_POLICY_ALLOWED) {
            connect(device);
        } else if (connectionPolicy == BluetoothProfile.CONNECTION_POLICY_FORBIDDEN) {
            disconnect(device);
        }
        return true;
    }

    /**
     * Gets the connection policy for the battery service of the given device.
     */
    @RequiresPermission(android.Manifest.permission.BLUETOOTH_PRIVILEGED)
    public int getConnectionPolicy(BluetoothDevice device) {
        enforceCallingOrSelfPermission(BLUETOOTH_PRIVILEGED,
                "Need BLUETOOTH_PRIVILEGED permission");
        return mDatabaseManager.getProfileConnectionPolicy(device, BluetoothProfile.BATTERY);
    }
    /**
     * Called when the battery level of the device is notified.
     */
    @VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
    public void handleBatteryChanged(BluetoothDevice device, int batteryLevel) {
        mAdapterService.setBatteryLevel(device, batteryLevel);
    }

    private BatteryStateMachine getOrCreateStateMachine(BluetoothDevice device) {
        if (device == null) {
            Log.e(TAG, "getOrCreateGatt failed: device cannot be null");
            return null;
        }
        synchronized (mStateMachines) {
            BatteryStateMachine sm = mStateMachines.get(device);
            if (sm != null) {
                return sm;
            }
            // Limit the maximum number of state machines to avoid DoS attack
            if (mStateMachines.size() >= MAX_BATTERY_STATE_MACHINES) {
                Log.e(TAG, "Maximum number of Battery state machines reached: "
                        + MAX_BATTERY_STATE_MACHINES);
                return null;
            }
            if (DBG) {
                Log.d(TAG, "Creating a new state machine for " + device);
            }
            sm = BatteryStateMachine.make(device, this, mStateMachinesThread.getLooper());
            mStateMachines.put(device, sm);
            return sm;
        }
    }

    // Remove state machine if the bonding for a device is removed
    private class BondStateChangedReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (!BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(intent.getAction())) {
                return;
            }
            int state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE,
                    BluetoothDevice.ERROR);
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            Objects.requireNonNull(device, "ACTION_BOND_STATE_CHANGED with no EXTRA_DEVICE");
            handleBondStateChanged(device, state);
        }
    }

    /**
     * Process a change in the bonding state for a device.
     *
     * @param device the device whose bonding state has changed
     * @param bondState the new bond state for the device. Possible values are:
     * {@link BluetoothDevice#BOND_NONE},
     * {@link BluetoothDevice#BOND_BONDING},
     * {@link BluetoothDevice#BOND_BONDED},
     * {@link BluetoothDevice#ERROR}.
     */
    @VisibleForTesting
    void handleBondStateChanged(BluetoothDevice device, int bondState) {
        if (DBG) {
            Log.d(TAG, "Bond state changed for device: " + device + " state: " + bondState);
        }
        // Remove state machine if the bonding for a device is removed
        if (bondState != BluetoothDevice.BOND_NONE) {
            return;
        }

        synchronized (mStateMachines) {
            BatteryStateMachine sm = mStateMachines.get(device);
            if (sm == null) {
                return;
            }
            if (sm.getConnectionState() != BluetoothProfile.STATE_DISCONNECTED) {
                return;
            }
            removeStateMachine(device);
        }
    }

    private void removeStateMachine(BluetoothDevice device) {
        if (device == null) {
            Log.e(TAG, "removeStateMachine failed: device cannot be null");
            return;
        }
        synchronized (mStateMachines) {
            BatteryStateMachine sm = mStateMachines.remove(device);
            if (sm == null) {
                Log.w(TAG, "removeStateMachine: device " + device
                        + " does not have a state machine");
                return;
            }
            Log.i(TAG, "removeGatt: removing bluetooth gatt for device: " + device);
            sm.doQuit();
            sm.cleanup();
        }
    }

    /**
     * Binder object: must be a static class or memory leak may occur
     */
    @VisibleForTesting
    static class BluetoothBatteryBinder extends IBluetoothBattery.Stub
            implements IProfileServiceBinder {
        private final WeakReference<BatteryService> mServiceRef;

        @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
        private BatteryService getService(AttributionSource source) {
            BatteryService service = mServiceRef.get();
            if (Utils.isInstrumentationTestMode()) {
                return service;
            }

            if (!Utils.checkServiceAvailable(service, TAG)
                    || !Utils.checkCallerIsSystemOrActiveOrManagedUser(service, TAG)
                    || !Utils.checkConnectPermissionForDataDelivery(service, source, TAG)) {
                return null;
            }
            return service;
        }

        BluetoothBatteryBinder(BatteryService svc) {
            mServiceRef = new WeakReference<>(svc);
        }

        @Override
        public void cleanup() {
            mServiceRef.clear();
        }

        @Override
        public void connect(BluetoothDevice device, AttributionSource source,
                SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                boolean result = false;
                if (service != null) {
                    result = service.connect(device);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void disconnect(BluetoothDevice device, AttributionSource source,
                SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                boolean result = false;
                if (service != null) {
                    result = service.disconnect(device);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void getConnectedDevices(AttributionSource source,
                SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                List<BluetoothDevice> result = new ArrayList<>();
                if (service != null) {
                    enforceBluetoothPrivilegedPermission(service);
                    result = service.getConnectedDevices();
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void getDevicesMatchingConnectionStates(int[] states,
                AttributionSource source, SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                List<BluetoothDevice> result = new ArrayList<>();
                if (service != null) {
                    result = service.getDevicesMatchingConnectionStates(states);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void getConnectionState(BluetoothDevice device, AttributionSource source,
                SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                int result = BluetoothProfile.STATE_DISCONNECTED;
                if (service != null) {
                    result = service.getConnectionState(device);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void setConnectionPolicy(BluetoothDevice device, int connectionPolicy,
                AttributionSource source, SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                boolean result = false;
                if (service != null) {
                    result = service.setConnectionPolicy(device, connectionPolicy);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }

        @Override
        public void getConnectionPolicy(BluetoothDevice device, AttributionSource source,
                SynchronousResultReceiver receiver) {
            try {
                BatteryService service = getService(source);
                int result = BluetoothProfile.CONNECTION_POLICY_UNKNOWN;
                if (service != null) {
                    result = service.getConnectionPolicy(device);
                }
                receiver.send(result);
            } catch (RuntimeException e) {
                receiver.propagateException(e);
            }
        }
    }

    @Override
    public void dump(StringBuilder sb) {
        super.dump(sb);
        for (BatteryStateMachine sm : mStateMachines.values()) {
            sm.dump(sb);
        }
    }
}