• Android 12 Bluetooth源码分析蓝牙配对

    本文主要是列出一些蓝牙配对重要的类和方法/函数，遇到相关问题时方便查找添加log排查。

    蓝牙扫描列表页面：packages/apps/Settings/src/com/android/settings/bluetooth/DeviceListPreferenceFragment.java点击其中一个设备会调用：onPreferenceTreeClick()

    1.     @Override
    2.     public boolean onPreferenceTreeClick(Preference preference) {
    3.         if (KEY_BT_SCAN.equals(preference.getKey())) {
    4.             startScanning();
    5.             return true;
    6.         }
    7.  
    8.         if (preference instanceof BluetoothDevicePreference) {
    9.             BluetoothDevicePreference btPreference = (BluetoothDevicePreference) preference;
    10.             CachedBluetoothDevice device = btPreference.getCachedDevice();
    11.             mSelectedDevice = device.getDevice();
    12.             mSelectedList.add(mSelectedDevice);
    13.             //配对
    14.             onDevicePreferenceClick(btPreference);
    15.             return true;
    16.         }
    17.  
    18.         return super.onPreferenceTreeClick(preference);
    19.     }

    接着调用 packages/apps/Settings/src/com/android/settings/bluetooth/BluetoothDevicePreference.java

    1. void onClicked() {
    2.         Context context = getContext();
    3.         int bondState = mCachedDevice.getBondState();
    4.  
    5.         final MetricsFeatureProvider metricsFeatureProvider =
    6.                 FeatureFactory.getFactory(context).getMetricsFeatureProvider();
    7.  
    8.         if (mCachedDevice.isConnected()) {
    9.             metricsFeatureProvider.action(context,
    10.                     SettingsEnums.ACTION_SETTINGS_BLUETOOTH_DISCONNECT);
    11.             askDisconnect();
    12.         } else if (bondState == BluetoothDevice.BOND_BONDED) {
    13.             metricsFeatureProvider.action(context,
    14.                     SettingsEnums.ACTION_SETTINGS_BLUETOOTH_CONNECT);
    15.             mCachedDevice.connect();
    16.         } else if (bondState == BluetoothDevice.BOND_NONE) {
    17.             metricsFeatureProvider.action(context,
    18.                     SettingsEnums.ACTION_SETTINGS_BLUETOOTH_PAIR);
    19.             if (!mCachedDevice.hasHumanReadableName()) {
    20.                 metricsFeatureProvider.action(context,
    21.                         SettingsEnums.ACTION_SETTINGS_BLUETOOTH_PAIR_DEVICES_WITHOUT_NAMES);
    22.             }
    23.             pair();//配对
    24.         }
    25.     }

    继续调用

    1. public boolean startPairing() {
    2.         // Pairing is unreliable while scanning, so cancel discovery
    3.         if (mLocalAdapter.isDiscovering()) {
    4.             mLocalAdapter.cancelDiscovery();
    5.         }
    6.         //创建配对
    7.         if (!mDevice.createBond()) {
    8.             return false;
    9.         }
    10.  
    11.         return true;
    12.     }

    一直往下会到BluetoothDevice.java，在里面调用了IBuletooth.aidl

    frameworks/base/core/java/android/bluetooth/BluetoothDevice.java
    1. @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
    2.     private boolean createBondInternal(int transport, @Nullable OobData remoteP192Data,
    3.             @Nullable OobData remoteP256Data) {
    4.         final IBluetooth service = sService;
    5.         if (service == null) {
    6.             Log.w(TAG, "BT not enabled, createBondOutOfBand failed");
    7.             return false;
    8.         }
    9.         try {
    10.             return service.createBond(
    11.                     this, transport, remoteP192Data, remoteP256Data, mAttributionSource);
    12.         } catch (RemoteException e) {
    13.             Log.e(TAG, "", e);
    14.         }
    15.         return false;
    16.     }

    在AdapterService.java里实现了IBluetooth.Stub

    packages/apps/Bluetooth/src/com/android/bluetooth/btservice/AdapterService.java

    1. @VisibleForTesting
    2.     public static class AdapterServiceBinder extends IBluetooth.Stub {
    3.         private AdapterService mService;
    4.  
    5.         AdapterServiceBinder(AdapterService svc) {
    6.             mService = svc;
    7.             mService.invalidateBluetoothGetStateCache();
    8.             BluetoothAdapter.getDefaultAdapter().disableBluetoothGetStateCache();
    9.         }
    10.         .....省略
    11.  
    12.  
    13.         @Override
    14.         public boolean createBond(BluetoothDevice device, int transport, OobData remoteP192Data,
    15.                 OobData remoteP256Data, AttributionSource attributionSource) {
    16.             Attributable.setAttributionSource(device, attributionSource);
    17.             AdapterService service = getService();
    18.             if (service == null || !callerIsSystemOrActiveOrManagedUser(service, TAG, "createBond")
    19.                     || !Utils.checkConnectPermissionForDataDelivery(
    20.                             service, attributionSource, "AdapterService createBond")) {
    21.                 return false;
    22.             }
    23.  
    24.             // This conditional is required to satisfy permission dependencies
    25.             // since createBond calls createBondOutOfBand with null value passed as data.
    26.             // BluetoothDevice#createBond requires BLUETOOTH_ADMIN only.
    27.             service.enforceBluetoothPrivilegedPermissionIfNeeded(remoteP192Data, remoteP256Data);
    28.             //进入createBond
    29.             return service.createBond(device, transport, remoteP192Data, remoteP256Data,
    30.                     attributionSource.getPackageName());
    31.         }
    32.     }
    1. boolean createBond(BluetoothDevice device, int transport, OobData remoteP192Data,
    2.             OobData remoteP256Data, String callingPackage) {
    3.         DeviceProperties deviceProp = mRemoteDevices.getDeviceProperties(device);
    4.         if (deviceProp != null && deviceProp.getBondState() != BluetoothDevice.BOND_NONE) {
    5.             return false;
    6.         }
    7.  
    8.         if (!isPackageNameAccurate(this, callingPackage, Binder.getCallingUid())) {
    9.             return false;
    10.         }
    11.  
    12.         CallerInfo createBondCaller = new CallerInfo();
    13.         createBondCaller.callerPackageName = callingPackage;
    14.         createBondCaller.user = UserHandle.of(UserHandle.getCallingUserId());
    15.         mBondAttemptCallerInfo.put(device.getAddress(), createBondCaller);
    16.  
    17.         mRemoteDevices.setBondingInitiatedLocally(Utils.getByteAddress(device));
    18.  
    19.         // Pairing is unreliable while scanning, so cancel discovery
    20.         // Note, remove this when native stack improves
    21.         cancelDiscoveryNative();
    22.  
    23.         Message msg = mBondStateMachine.obtainMessage(BondStateMachine.CREATE_BOND);
    24.         msg.obj = device;
    25.         msg.arg1 = transport;
    26.  
    27.         Bundle remoteOobDatasBundle = new Bundle();
    28.         boolean setData = false;
    29.         if (remoteP192Data != null) {
    30.             remoteOobDatasBundle.putParcelable(BondStateMachine.OOBDATAP192, remoteP192Data);
    31.             setData = true;
    32.         }
    33.         if (remoteP256Data != null) {
    34.             remoteOobDatasBundle.putParcelable(BondStateMachine.OOBDATAP256, remoteP256Data);
    35.             setData = true;
    36.         }
    37.         if (setData) {
    38.             msg.setData(remoteOobDatasBundle);
    39.         }
    40.         //发送配对message
    41.         mBondStateMachine.sendMessage(msg);
    42.         return true;
    43.     }

    接着进入packages/apps/Bluetooth/src/com/android/bluetooth/btservice/BondStateMachine.java

    1. private boolean createBond(BluetoothDevice dev, int transport, OobData remoteP192Data,
    2.             OobData remoteP256Data, boolean transition) {
    3.         if (dev.getBondState() == BluetoothDevice.BOND_NONE) {
    4.             infoLog("Bond address is:" + dev);
    5.             byte[] addr = Utils.getBytesFromAddress(dev.getAddress());
    6.             boolean result;
    7.             // If we have some data
    8.             if (remoteP192Data != null || remoteP256Data != null) {
    9.                 result = mAdapterService.createBondOutOfBandNative(addr, transport,
    10.                     remoteP192Data, remoteP256Data);
    11.             } else {
    12.                 //调用了native的代码
    13.                 result = mAdapterService.createBondNative(addr, transport);
    14.             }
    15.             BluetoothStatsLog.write(BluetoothStatsLog.BLUETOOTH_BOND_STATE_CHANGED,
    16.                     mAdapterService.obfuscateAddress(dev), transport, dev.getType(),
    17.                     BluetoothDevice.BOND_BONDING,
    18.                     remoteP192Data == null && remoteP256Data == null
    19.                             ? BluetoothProtoEnums.BOND_SUB_STATE_UNKNOWN
    20.                             : BluetoothProtoEnums.BOND_SUB_STATE_LOCAL_OOB_DATA_PROVIDED,
    21.                     BluetoothProtoEnums.UNBOND_REASON_UNKNOWN);
    22.  
    23.             if (!result) {
    24.                 BluetoothStatsLog.write(BluetoothStatsLog.BLUETOOTH_BOND_STATE_CHANGED,
    25.                         mAdapterService.obfuscateAddress(dev), transport, dev.getType(),
    26.                         BluetoothDevice.BOND_NONE, BluetoothProtoEnums.BOND_SUB_STATE_UNKNOWN,
    27.                         BluetoothDevice.UNBOND_REASON_REPEATED_ATTEMPTS);
    28.                 // Using UNBOND_REASON_REMOVED for legacy reason
    29.                 sendIntent(dev, BluetoothDevice.BOND_NONE, BluetoothDevice.UNBOND_REASON_REMOVED);
    30.                 return false;
    31.             } else if (transition) {
    32.                 transitionTo(mPendingCommandState);
    33.             }
    34.             return true;
    35.         }
    36.         return false;
    37.     }

    这里调到了JNI层的代码，进入packages/apps/Bluetooth/jni/com_android_bluetooth_btservice_AdapterService.cpp

    1. static jboolean createBondNative(JNIEnv* env, jobject obj, jbyteArray address,
    2.                                  jint transport) {
    3.   ALOGV("%s", __func__);
    4.  
    5.   if (!sBluetoothInterface) return JNI_FALSE;
    6.  
    7.   jbyte* addr = env->GetByteArrayElements(address, NULL);
    8.   if (addr == NULL) {
    9.     jniThrowIOException(env, EINVAL);
    10.     return JNI_FALSE;
    11.   }
    12.   //调用hal层的配对函数
    13.   int ret = sBluetoothInterface->create_bond((RawAddress*)addr, transport);
    14.   env->ReleaseByteArrayElements(address, addr, 0);
    15.   return (ret == BT_STATUS_SUCCESS) ? JNI_TRUE : JNI_FALSE;
    16. }

    调用到了hal层的代码，在蓝牙协议栈里 system/bt/btif/src/bluetooth.cc

    1. static int create_bond(const RawAddress* bd_addr, int transport) {
    2.   if (!interface_ready()) return BT_STATUS_NOT_READY;
    3.   if (btif_dm_pairing_is_busy()) return BT_STATUS_BUSY;
    4.  
    5.     //调用了btif_dm_create_bond
    6.   do_in_main_thread(FROM_HERE,
    7.                     base::BindOnce(btif_dm_create_bond, *bd_addr, transport));
    8.   return BT_STATUS_SUCCESS;
    9. }

    调用到了system/bt/btif/src/btif_dm.cc

    1. /*******************************************************************************
    2.  *
    3.  * Function         btif_dm_create_bond
    4.  *
    5.  * Description      Initiate bonding with the specified device
    6.  *
    7.  ******************************************************************************/
    8. void btif_dm_create_bond(const RawAddress bd_addr, int transport) {
    9.   BTIF_TRACE_EVENT("%s: bd_addr=%s, transport=%d", __func__,
    10.                    bd_addr.ToString().c_str(), transport);
    11.   btif_stats_add_bond_event(bd_addr, BTIF_DM_FUNC_CREATE_BOND,
    12.                             pairing_cb.state);
    13.  
    14.   pairing_cb.timeout_retries = NUM_TIMEOUT_RETRIES;
    15.   btif_dm_cb_create_bond(bd_addr, transport);
    16. }
    1. static void btif_dm_cb_create_bond(const RawAddress bd_addr,
    2.                                    tBT_TRANSPORT transport) {
    3.   bool is_hid = check_cod(&bd_addr, COD_HID_POINTING);
    4.   bond_state_changed(BT_STATUS_SUCCESS, bd_addr, BT_BOND_STATE_BONDING);
    5.  
    6.   int device_type = 0;
    7.   tBLE_ADDR_TYPE addr_type = BLE_ADDR_PUBLIC;
    8.   std::string addrstr = bd_addr.ToString();
    9.   const char* bdstr = addrstr.c_str();
    10.   if (transport == BT_TRANSPORT_LE) {
    11.     if (!btif_config_get_int(bdstr, "DevType", &device_type)) {
    12.       btif_config_set_int(bdstr, "DevType", BT_DEVICE_TYPE_BLE);
    13.     }
    14.     if (btif_storage_get_remote_addr_type(&bd_addr, &addr_type) !=
    15.         BT_STATUS_SUCCESS) {
    16.       // Try to read address type. OOB pairing might have set it earlier, but
    17.       // didn't store it, it defaults to BLE_ADDR_PUBLIC
    18.       uint8_t tmp_dev_type;
    19.       tBLE_ADDR_TYPE tmp_addr_type = BLE_ADDR_PUBLIC;
    20.       BTM_ReadDevInfo(bd_addr, &tmp_dev_type, &tmp_addr_type);
    21.       addr_type = tmp_addr_type;
    22.  
    23.       btif_storage_set_remote_addr_type(&bd_addr, addr_type);
    24.     }
    25.   }
    26.   if ((btif_config_get_int(bdstr, "DevType", &device_type) &&
    27.        (btif_storage_get_remote_addr_type(&bd_addr, &addr_type) ==
    28.         BT_STATUS_SUCCESS) &&
    29.        (device_type & BT_DEVICE_TYPE_BLE) == BT_DEVICE_TYPE_BLE) ||
    30.       (transport == BT_TRANSPORT_LE)) {
    31.     BTA_DmAddBleDevice(bd_addr, addr_type, device_type);
    32.   }
    33.  
    34.   if (is_hid && (device_type & BT_DEVICE_TYPE_BLE) == 0) {
    35.     bt_status_t status;
    36.     status = (bt_status_t)btif_hh_connect(&bd_addr);
    37.     if (status != BT_STATUS_SUCCESS)
    38.       bond_state_changed(status, bd_addr, BT_BOND_STATE_NONE);
    39.   } else {
    40.     //执行到这个方法
    41.     BTA_DmBond(bd_addr, addr_type, transport, device_type);
    42.   }
    43.   /*  Track  originator of bond creation  */
    44.   pairing_cb.is_local_initiated = true;
    45. }

    这个函数BTA_DmBond里调用到了system/bt/bta/dm/bta_dm_act.cc

    1. /** Bonds with peer device */
    2. void bta_dm_bond(const RawAddress& bd_addr, tBLE_ADDR_TYPE addr_type,
    3.                  tBT_TRANSPORT transport, int device_type) {
    4.   tBTA_DM_SEC sec_event;
    5.   char* p_name;
    6.   
    7.   //在BTM_SecBond函数发送配对信息，蓝牙地址、数据、命令等信息
    8.   tBTM_STATUS status =
    9.       (bluetooth::shim::is_gd_security_enabled())
    10.           ? bluetooth::shim::BTM_SecBond(bd_addr, addr_type, transport,
    11.                                          device_type)
    12.           : BTM_SecBond(bd_addr, addr_type, transport, device_type, 0, NULL);
    13.  
    14.   if (bta_dm_cb.p_sec_cback && (status != BTM_CMD_STARTED)) {
    15.     memset(&sec_event, 0, sizeof(tBTA_DM_SEC));
    16.     sec_event.auth_cmpl.bd_addr = bd_addr;
    17.     p_name = (bluetooth::shim::is_gd_security_enabled())
    18.                  ? bluetooth::shim::BTM_SecReadDevName(bd_addr)
    19.                  : BTM_SecReadDevName(bd_addr);
    20.     if (p_name != NULL) {
    21.       memcpy(sec_event.auth_cmpl.bd_name, p_name, BD_NAME_LEN);
    22.       sec_event.auth_cmpl.bd_name[BD_NAME_LEN] = 0;
    23.     }
    24.  
    25.     /*      taken care of by memset [above]
    26.             sec_event.auth_cmpl.key_present = false;
    27.             sec_event.auth_cmpl.success = false;
    28.     */
    29.     sec_event.auth_cmpl.fail_reason = HCI_ERR_ILLEGAL_COMMAND;
    30.     if (status == BTM_SUCCESS) {
    31.       sec_event.auth_cmpl.success = true;
    32.     } else {
    33.       /* delete this device entry from Sec Dev DB */
    34.       bta_dm_remove_sec_dev_entry(bd_addr);
    35.     }
    36.     bta_dm_cb.p_sec_cback(BTA_DM_AUTH_CMPL_EVT, &sec_event);
    37.   }
    38. }

    来到system/bt/stack/btm/btm_sec.cc，最终在这里发送命令给HCI与硬件打交道

    1. /*******************************************************************************
    2.  *
    3.  * Function         BTM_SecBond
    4.  *
    5.  * Description      This function is called to perform bonding with peer device.
    6.  *                  If the connection is already up, but not secure, pairing
    7.  *                  is attempted.  If already paired BTM_SUCCESS is returned.
    8.  *
    9.  * Parameters:      bd_addr      - Address of the device to bond
    10.  *                  transport    - doing SSP over BR/EDR or SMP over LE
    11.  *                  pin_len      - length in bytes of the PIN Code
    12.  *                  p_pin        - pointer to array with the PIN Code
    13.  *
    14.  *  Note: After 2.1 parameters are not used and preserved here not to change API
    15.  ******************************************************************************/
    16. tBTM_STATUS BTM_SecBond(const RawAddress& bd_addr, tBLE_ADDR_TYPE addr_type,
    17.                         tBT_TRANSPORT transport, int device_type,
    18.                         uint8_t pin_len, uint8_t* p_pin) {
    19.   if (bluetooth::shim::is_gd_shim_enabled()) {
    20.     return bluetooth::shim::BTM_SecBond(bd_addr, addr_type, transport,
    21.                                         device_type);
    22.   }
    23.  
    24.   if (transport == BT_TRANSPORT_INVALID)
    25.     transport = BTM_UseLeLink(bd_addr) ? BT_TRANSPORT_LE : BT_TRANSPORT_BR_EDR;
    26.  
    27.   tBT_DEVICE_TYPE dev_type;
    28.  
    29.   BTM_ReadDevInfo(bd_addr, &dev_type, &addr_type);
    30.   /* LE device, do SMP pairing */
    31.   if ((transport == BT_TRANSPORT_LE && (dev_type & BT_DEVICE_TYPE_BLE) == 0) ||
    32.       (transport == BT_TRANSPORT_BR_EDR &&
    33.        (dev_type & BT_DEVICE_TYPE_BREDR) == 0)) {
    34.     return BTM_ILLEGAL_ACTION;
    35.   }
    36.   //执行btm_sec_bond_by_transport函数
    37.   return btm_sec_bond_by_transport(bd_addr, transport, pin_len, p_pin);
    38. }
    39.  
    40.  
    41. /*******************************************************************************
    42.  *
    43.  * Function         btm_sec_bond_by_transport
    44.  *
    45.  * Description      this is the bond function that will start either SSP or SMP.
    46.  *
    47.  * Parameters:      bd_addr      - Address of the device to bond
    48.  *                  pin_len      - length in bytes of the PIN Code
    49.  *                  p_pin        - pointer to array with the PIN Code
    50.  *
    51.  *  Note: After 2.1 parameters are not used and preserved here not to change API
    52.  ******************************************************************************/
    53. tBTM_STATUS btm_sec_bond_by_transport(const RawAddress& bd_addr,
    54.                                       tBT_TRANSPORT transport, uint8_t pin_len,
    55.                                       uint8_t* p_pin) {
    56.  
    57.   //....代码太多，最底层就是发送控制命令
    58.  
    59.   if (!controller_get_interface()->supports_simple_pairing()) {
    60.     /* The special case when we authenticate keyboard.  Set pin type to fixed */
    61.     /* It would be probably better to do it from the application, but it is */
    62.     /* complicated */
    63.     if (((p_dev_rec->dev_class[1] & BTM_COD_MAJOR_CLASS_MASK) ==
    64.          BTM_COD_MAJOR_PERIPHERAL) &&
    65.         (p_dev_rec->dev_class[2] & BTM_COD_MINOR_KEYBOARD) &&
    66.         (btm_cb.cfg.pin_type != HCI_PIN_TYPE_FIXED)) {
    67.       btm_cb.pin_type_changed = true;
    68.       
    69.       //通过HCI向底层发送命令
    70.       btsnd_hcic_write_pin_type(HCI_PIN_TYPE_FIXED);
    71.     }
    72.   }
    73.   return status;
    74. }

    到这里就结束了，后面就是控制硬件发起配对操作。

  • 相关阅读:
    Elasticsearch和sboot整合
    插入排序算法
    Avalonia踩坑
    Java判断字符串是否是有效的括号
    QDockWidget重新实现的事件处理
    流式结构化数据计算语言的进化与新选择
    一种优雅的Git分支实践
    NR CSI(三) CQI
    Spring Security 实战 01 Security核心功能解析
    CrystalNet ADO.Net VCL for Delphi
  • 原文地址：https://blog.csdn.net/gxhea/article/details/133171386