bluetoothd的启动流程
梳理bluetoothd的启动流程，总结一下
./bluetoothd -h
Usage:
bluetoothd [OPTION...]
Help Options:
-h, --help Show help options
Application Options:
-d, --debug=DEBUG Specify debug options to enable
-p, --plugin=NAME,.., Specify plugins to load
-P, --noplugin=NAME,... Specify plugins not to load
-f, --configfile=FILE Specify an explicit path to the config file
-C, --compat Provide deprecated command line interfaces
-E, --experimental Enable experimental interfaces
-n, --nodetach Run with logging in foreground
-v, --version Show version information and exit正常启动
./bluetoothd -n --compat &
调试
./bluetoothd -n --compat -f /opt/main.conf -d
源码：
1.从src/main.c中int main开始,解析启动参数
649 int main(int argc, char *argv[])
650 {
651 GOptionContext *context;
652 GError *err = NULL;
653 uint16_t sdp_mtu = 0;
654 uint32_t sdp_flags = 0;
655 int gdbus_flags = 0;
656 guint signal, watchdog;
657 const char *watchdog_usec;
658 /*初始化配置参数main_opt(如果启动时带有-f参数，会将对应的配置赋值给main_opt)*/
659 init_defaults();
660 /*调用glib库,初始化启动参数选项*/
661 context = g_option_context_new(NULL);
662 g_option_context_add_main_entries(context, options, NULL);
663 /*解析启动参数*/
664 if (g_option_context_parse(context, &argc, &argv, &err) == FALSE) {
665 if (err != NULL) {
666 g_printerr("%s\n", err->message);
667 g_error_free(err);
668 } else
669 g_printerr("An unknown error occurred\n");
670 exit(1);
671 }
672
673 g_option_context_free(context);
674 /*如果启动参数中有-v则直接打印版本号然后退出*/
675 if (option_version == TRUE) {
676 printf("%s\n", VERSION);
677 exit(0);
678 }2.解析配置文件
680 umask(0077);
681
682 btd_backtrace_init();
683 /*创建事件处理句柄*/
684 event_loop = g_main_loop_new(NULL, FALSE);
685 /*设置信号处理函数，bluetoothd进程结束时释放资源*/
686 signal = setup_signalfd();
687 /*打印初始化*/
688 __btd_log_init(option_debug, option_detach);
689
690 g_log_set_handler("GLib", G_LOG_LEVEL_MASK | G_LOG_FLAG_FATAL |
691 G_LOG_FLAG_RECURSION,
692 log_handler, NULL);
693
694 sd_notify(0, "STATUS=Starting up");
695 /*解析配置文件*/
696 if (option_configfile)
697 main_conf_file_path = option_configfile;
698 else
699 main_conf_file_path = CONFIGDIR "/main.conf";
700
701 main_conf = load_config(main_conf_file_path);
702
703 parse_config(main_conf);
704 /*连接dbus*/
705 if (connect_dbus() < 0) {
706 error("Unable to get on D-Bus");
707 exit(1);
708 }
709
710 if (option_experimental)
711 gdbus_flags = G_DBUS_FLAG_ENABLE_EXPERIMENTAL;
712
713 g_dbus_set_flags(gdbus_flags);3.src/adapter.c中适配器初始化
8677 int adapter_init(void)
8678 {
8679 dbus_conn = btd_get_dbus_connection();/*获取dbus连接后的句柄*/
8680 /*获取mgmt句柄，用于和内核层mgmt进行通信*/
8681 mgmt_master = mgmt_new_default();
8682 if (!mgmt_master) {
8683 error("Failed to access management interface");
8684 return -EIO;
8685 }
8686
8687 if (getenv("MGMT_DEBUG"))
8688 mgmt_set_debug(mgmt_master, mgmt_debug, "mgmt: ", NULL);
8689
8690 DBG("sending read version command");
8691 /*向内核发送读取mgmt版本号,具体定义在net/bluetooth/mgmt.c中MGMT_VERSION与MGMT_REVISION*/
8692 if (mgmt_send(mgmt_master, MGMT_OP_READ_VERSION,
8693 MGMT_INDEX_NONE, 0, NULL,
8694 read_version_complete, NULL, NULL) > 0)
8695 return 0;
8696
8697 error("Failed to read management version information");
8698
8699 return -EIO;
8700 }4.mgmt读取版本号返回
8618 static void read_version_complete(uint8_t status, uint16_t length,
8619 const void *param, void *user_data)
8620 {
8621 const struct mgmt_rp_read_version *rp = param;
8622
8623 if (status != MGMT_STATUS_SUCCESS) {
8624 error("Failed to read version information: %s (0x%02x)",
8625 mgmt_errstr(status), status);
8626 return;
8627 }
8628
8629 if (length < sizeof(*rp)) {
8630 error("Wrong size of read version response");
8631 return;
8632 }
8633 /*获取到版本号*/
8634 mgmt_version = rp->version;
8635 mgmt_revision = btohs(rp->revision);
8636
8637 info("Bluetooth management interface %u.%u initialized",
8638 mgmt_version, mgmt_revision);
8639
8640 if (mgmt_version < 1) {
8641 error("Version 1.0 or later of management interface required");
8642 abort();
8643 }
8644
8645 DBG("sending read supported commands command");
8646 /*继续发送指令，获取内核mgmt支持的命令与事件，监听接口添加或删除事件，获取当前接口列表*/
8647 /*
8648 * It is irrelevant if this command succeeds or fails. In case of
8649 * failure safe settings are assumed.
8650 */
8651 mgmt_send(mgmt_master, MGMT_OP_READ_COMMANDS,
8652 MGMT_INDEX_NONE, 0, NULL,
8653 read_commands_complete, NULL, NULL);/*仅将数目赋值给相应变量*/
8654
8655 mgmt_register(mgmt_master, MGMT_EV_INDEX_ADDED, MGMT_INDEX_NONE,
8656 index_added, NULL, NULL);
8657 mgmt_register(mgmt_master, MGMT_EV_INDEX_REMOVED, MGMT_INDEX_NONE,
8658 index_removed, NULL, NULL);
8659
8660 DBG("sending read index list command");
8661
8662 if (mgmt_send(mgmt_master, MGMT_OP_READ_INDEX_LIST,
8663 MGMT_INDEX_NONE, 0, NULL,
8664 read_index_list_complete, NULL, NULL) > 0)
8665 return;
8667 error("Failed to read controller index list");
8668 }5.获取到接口数,调用index_add添加接口
8527 static void read_index_list_complete(uint8_t status, uint16_t length,
8528 const void *param, void *user_data)
8529 {
8530 const struct mgmt_rp_read_index_list *rp = param;
8531 uint16_t num;
8532 int i;
8533
8534 if (status != MGMT_STATUS_SUCCESS) {
8535 error("Failed to read index list: %s (0x%02x)",
8536 mgmt_errstr(status), status);
8537 return;
8538 }
8539
8540 if (length < sizeof(*rp)) {
8541 error("Wrong size of read index list response");
8542 return;
8543 }
8544
8545 num = btohs(rp->num_controllers);
8546
8547 DBG("Number of controllers: %d", num);
8548
8549 if (num * sizeof(uint16_t) + sizeof(*rp) != length) {
8550 error("Incorrect packet size for index list response");
8551 return;
8552 }
8553
8554 for (i = 0; i < num; i++) {
8555 uint16_t index;
8556
8557 index = btohs(rp->index[i]);
8558
8559 DBG("Found index %u", index);
8560 /*添加接口*/
8561 /*
8562 * Pretend to be index added event notification.
8563 *
8564 * It is safe to just trigger the procedure for index
8565 * added notification. It does check against itself.
8566 */
8567 index_added(index, 0, NULL, NULL);
8568 }
8569 }6.添加接口(一个接口对应一个adapter)
8463 static void index_added(uint16_t index, uint16_t length, const void *param,
8464 void *user_data)
8465 {
8466 struct btd_adapter *adapter;
8467
8468 DBG("index %u", index);
8469 /*查看是否已经建立，条件不成立*/
8470 adapter = btd_adapter_lookup(index);
8471 if (adapter) {
8472 btd_warn(adapter->dev_id,
8473 "Ignoring index added for an already existing adapter");
8474 return;
8475 }
8476 /*新建适配器，将main_opt中参数赋值，mgmt句柄赋值*/
8477 adapter = btd_adapter_new(index);
8478 if (!adapter) {
8479 btd_error(index,
8480 "Unable to create new adapter for index %u", index);
8481 return;
8482 }
8483 /*添加到适配器链表中*/
8484 /*
8485 * Protect against potential two executions of read controller info.
8486 *
8487 * In case the start of the daemon and the action of adding a new
8488 * controller coincide this function might be called twice.
8489 *
8490 * To avoid the double execution of reading the controller info,
8491 * add the adapter already to the list. If an adapter is already
8492 * present, the second notification will cause a warning. If the
8493 * command fails the adapter is removed from the list again.
8494 */
8495 adapter_list = g_list_append(adapter_list, adapter);
8496
8497 DBG("sending read info command for index %u", index);
8498 /*获取内核中所知的蓝牙信息*/
8499 if (mgmt_send(mgmt_master, MGMT_OP_READ_INFO, index, 0, NULL,
8500 read_info_complete, adapter, NULL) > 0)
8501 return;
8502
8503 btd_error(adapter->dev_id,
8504 "Failed to read controller info for index %u", index);
8505
8506 adapter_list = g_list_remove(adapter_list, adapter);
8507
8508 btd_adapter_unref(adapter);
8509 }7.解析蓝牙信息(一)
8205 static void read_info_complete(uint8_t status, uint16_t length,
8206 const void *param, void *user_data)
8207 {
8208 struct btd_adapter *adapter = user_data;
8209 const struct mgmt_rp_read_info *rp = param;
8210 uint32_t missing_settings;
8211 int err;
8212
8213 DBG("index %u status 0x%02x", adapter->dev_id, status);
8214
8215 if (status != MGMT_STATUS_SUCCESS) {
8216 btd_error(adapter->dev_id,
8217 "Failed to read info for index %u: %s (0x%02x)",
8218 adapter->dev_id, mgmt_errstr(status), status);
8219 goto failed;
8220 }
8221
8222 if (length < sizeof(*rp)) {
8223 btd_error(adapter->dev_id,
8224 "Too small read info complete response");
8225 goto failed;
8226 }
8227 /*获取到蓝牙信息，赋值给adapter*/
8228 /*
8229 * Store controller information for class of device, device
8230 * name, short name and settings.
8231 *
8232 * During the lifetime of the controller these will be updated by
8233 * events and the information is required to keep the current
8234 * state of the controller.
8235 */
8236 adapter->dev_class = rp->dev_class[0] | (rp->dev_class[1] << 8) |
8237 (rp->dev_class[2] << 16);
8238 adapter->name = g_strdup((const char *) rp->name);
8239 adapter->short_name = g_strdup((const char *) rp->short_name);
8240
8241 adapter->manufacturer = btohs(rp->manufacturer);
8242 /*获取支持的配置选项，以及当前的配置状态,具体宏定义在lib/mgmt.h中可见*/
8243 adapter->supported_settings = btohl(rp->supported_settings);
8244 adapter->current_settings = btohl(rp->current_settings);
8245 /*清理uuid和devices，防止本次启动后还使用上次bluetoothd中的uuid和扫描到的设备*/
8246 clear_uuids(adapter);
8247 clear_devices(adapter);８.解析蓝牙信息(二)
/*检测获取的蓝牙MAC是否正常*/
8249 if (bacmp(&rp->bdaddr, BDADDR_ANY) == 0) {
8250 if (!set_static_addr(adapter)) {
8251 btd_error(adapter->dev_id,
8252 "No Bluetooth address for index %u",
8253 adapter->dev_id);
8254 goto failed;
8255 }
8256 } else {
8257 bacpy(&adapter->bdaddr, &rp->bdaddr);
8258 if (!(adapter->supported_settings & MGMT_SETTING_LE))
8259 adapter->bdaddr_type = BDADDR_BREDR;
8260 else
8261 adapter->bdaddr_type = BDADDR_LE_PUBLIC;
8262 }
8263 /*异或，获取到未被配置的*/
8264 missing_settings = adapter->current_settings ^
8265 adapter->supported_settings;
8266 /*根据配置文件的参数来，设置蓝牙运行模式分别为DUAL(蓝牙串口),BREDR(经典蓝牙),BLE(低功耗蓝牙),set_mode实际为mgmt_send封装*/
8267 switch (main_opts.mode) {
8268 case BT_MODE_DUAL:
8269 if (missing_settings & MGMT_SETTING_SSP)
8270 set_mode(adapter, MGMT_OP_SET_SSP, 0x01);
8271 if (missing_settings & MGMT_SETTING_LE)
8272 set_mode(adapter, MGMT_OP_SET_LE, 0x01);
8273 if (missing_settings & MGMT_SETTING_BREDR)
8274 set_mode(adapter, MGMT_OP_SET_BREDR, 0x01);
8275 break;
8276 case BT_MODE_BREDR:
8277 if (!(adapter->supported_settings & MGMT_SETTING_BREDR)) {
8278 btd_error(adapter->dev_id,
8279 "Ignoring adapter withouth BR/EDR support");
8280 goto failed;
8281 }
8282
8283 if (missing_settings & MGMT_SETTING_SSP)
8284 set_mode(adapter, MGMT_OP_SET_SSP, 0x01);
8285 if (missing_settings & MGMT_SETTING_BREDR)
8286 set_mode(adapter, MGMT_OP_SET_BREDR, 0x01);
8287 if (adapter->current_settings & MGMT_SETTING_LE)
8288 set_mode(adapter, MGMT_OP_SET_LE, 0x00);
8289 break;
8290 case BT_MODE_LE:
8291 if (!(adapter->supported_settings & MGMT_SETTING_LE)) {
8292 btd_error(adapter->dev_id,
8293 "Ignoring adapter withouth LE support");
8294 goto failed;
8295 }
8296
8297 if (missing_settings & MGMT_SETTING_LE)
8298 set_mode(adapter, MGMT_OP_SET_LE, 0x01);
8299 if (adapter->current_settings & MGMT_SETTING_BREDR)
8300 set_mode(adapter, MGMT_OP_SET_BREDR, 0x00);
8301 break;
8302 }
8303 /*蓝牙交互安全配置*/
8304 if (missing_settings & MGMT_SETTING_SECURE_CONN)
8305 set_mode(adapter, MGMT_OP_SET_SECURE_CONN, 0x01);
8306
8307 if (adapter->supported_settings & MGMT_SETTING_PRIVACY)
8308 set_privacy(adapter, main_opts.privacy);
8309 /*设置快速链接*/
8310 if (main_opts.fast_conn &&
8311 (missing_settings & MGMT_SETTING_FAST_CONNECTABLE))
8312 set_mode(adapter, MGMT_OP_SET_FAST_CONNECTABLE, 0x01);9.解析蓝牙信息(三)
/*注册dbus接口*/
8314 err = adapter_register(adapter);
8315 if (err < 0) {
8316 btd_error(adapter->dev_id, "Unable to register new adapter");
8317 goto failed;
8318 }
8319 /*监听mgmt上报事件，由于监听事件太多，省略一部分*/
8320 /*
8321 * Register all event notification handlers for controller.
8322 *
8323 * The handlers are registered after a succcesful read of the
8324 * controller info. From now on they can track updates and
8325 * notifications.
8326 */
8327 mgmt_register(adapter->mgmt, MGMT_EV_NEW_SETTINGS, adapter->dev_id,
8328 new_settings_callback, adapter, NULL);
8329
8330 mgmt_register(adapter->mgmt, MGMT_EV_CLASS_OF_DEV_CHANGED,
8331 adapter->dev_id,
8332 dev_class_changed_callback,
8333 adapter, NULL);
..............................................
..............................................
8423 mgmt_register(adapter->mgmt, MGMT_EV_PASSKEY_NOTIFY,
8424 adapter->dev_id,
8425 user_passkey_notify_callback,
8426 adapter, NULL);
8427
8428 set_dev_class(adapter);
8429 /*设置蓝牙名*/
8430 set_name(adapter, btd_adapter_get_name(adapter));
8431 /*开启绑定*/
8432 if (!(adapter->current_settings & MGMT_SETTING_BONDABLE))
8433 set_mode(adapter, MGMT_OP_SET_BONDABLE, 0x01);
8434 /*是否可被连接*/
8435 if (!kernel_conn_control)
8436 set_mode(adapter, MGMT_OP_SET_CONNECTABLE, 0x01);
8437 else if (adapter->current_settings & MGMT_SETTING_CONNECTABLE)
8438 set_mode(adapter, MGMT_OP_SET_CONNECTABLE, 0x00);
8439 /*是否可被扫描到*/
8440 if (adapter->stored_discoverable && !adapter->discoverable_timeout)
8441 set_discoverable(adapter, 0x01, 0);
8442 /*向dbus发送启用蓝牙，最终还是会调用mgmt_send通知内核启用蓝牙(调adapter_init中注册的接口)*/
8443 if (adapter->current_settings & MGMT_SETTING_POWERED)
8444 adapter_start(adapter);
8445
8446 return;
8447
8448 failed:
8449 /*
8450 * Remove adapter from list in case of a failure.
8451 *
8452 * Leaving an adapter structure around for a controller that can
8453 * not be initilized makes no sense at the moment.
8454 *
8455 * This is a simplification to avoid constant checks if the
8456 * adapter is ready to do anything.
8457 */
8458 adapter_list = g_list_remove(adapter_list, adapter);
8459
8460 btd_adapter_unref(adapter);
8461 }10.适配器注册
7711 static int adapter_register(struct btd_adapter *adapter)
7712 {
7713 struct agent *agent;
7714 struct gatt_db *db;
7715
7716 if (powering_down)
7717 return -EBUSY;
7718 /*注册dbus调用接口*/
7719 adapter->path = g_strdup_printf("/org/bluez/hci%d", adapter->dev_id);
7720
7721 if (!g_dbus_register_interface(dbus_conn,
7722 adapter->path, ADAPTER_INTERFACE,
7723 adapter_methods, NULL,
7724 adapter_properties, adapter,
7725 adapter_free)) {
7726 btd_error(adapter->dev_id,
7727 "Adapter interface init failed on path %s",
7728 adapter->path);
7729 g_free(adapter->path);
7730 adapter->path = NULL;
7731 return -EINVAL;
7732 }
7733
7734 if (adapters == NULL)
7735 adapter->is_default = true;
7736 /*添加到链表中*/
7737 adapters = g_slist_append(adapters, adapter);
7738 /*获取代理，目前应该为NULL*/
7739 agent = agent_get(NULL);
7740 if (agent) {
7741 uint8_t io_cap = agent_get_io_capability(agent);
7742 adapter_set_io_capability(adapter, io_cap);
7743 agent_unref(agent);
7744 }
7745 /*ble与bredr建立监听L2CAP层监听事件，添加gap与gatt基础服务*/
7746 adapter->database = btd_gatt_database_new(adapter);
7747 if (!adapter->database) {
7748 btd_error(adapter->dev_id,
7749 "Failed to create GATT database for adapter");
7750 adapters = g_slist_remove(adapters, adapter);
7751 return -EINVAL;
7752 }
7753
7754 /* Don't start advertising managers on non-LE controllers. */
7755 if (adapter->supported_settings & MGMT_SETTING_LE)
7756 adapter->adv_manager = btd_adv_manager_new(adapter);
7757 else
7758 btd_info(adapter->dev_id,
7759 "LEAdvertisingManager skipped, LE unavailable");
7760 /*添加gatt接口*/
7761 db = btd_gatt_database_get_db(adapter->database);
7762 adapter->db_id = gatt_db_register(db, services_modified,
7763 services_modified,
7764 adapter, NULL);
7765 /*获取/var/lib/bluetooth/中的各个参数并配置，目前没用到*/
7766 load_config(adapter);
7767 fix_storage(adapter);
7768 load_drivers(adapter);
7769 btd_profile_foreach(probe_profile, adapter);
7770 clear_blocked(adapter);
7771 load_devices(adapter);
7772
7773 /* retrieve the active connections: address the scenario where
7774 * the are active connections before the daemon've started */
7775 if (adapter->current_settings & MGMT_SETTING_POWERED)
7776 load_connections(adapter);
7777
7778 adapter->initialized = TRUE;
7779
7780 if (main_opts.did_source) {
7781 /* DeviceID record is added by sdpd-server before any other
7782 * record is registered. */
7783 adapter_service_insert(adapter, sdp_record_find(0x10000));
7784 set_did(adapter, main_opts.did_vendor, main_opts.did_product,
7785 main_opts.did_version, main_opts.did_source);
7786 }
7787
7788 DBG("Adapter %s registered", adapter->path);
7789
7790 return 0;
7791 }11.回到int main中
/*注册dbus接口*/
720 btd_device_init();
721 btd_agent_init();
722 btd_profile_init();
723 if (main_opts.mode != BT_MODE_LE) {
724 if (option_compat == TRUE)
725 sdp_flags |= SDP_SERVER_COMPAT;
726 /*创建sdp句柄，赋值本地uuid服务，监听l2cap与unix(sdptool交互)套接字*/
727 start_sdp_server(sdp_mtu, sdp_flags);
728
729 if (main_opts.did_source > 0)
730 register_device_id(main_opts.did_source,
731 main_opts.did_vendor,
732 main_opts.did_product,
733 main_opts.did_version);
734 }
735
736 if (mps != MPS_OFF)
737 register_mps(mps == MPS_MULTIPLE);
738 /*初始化各种profile*/
739 /* Loading plugins has to be done after D-Bus has been setup since
740 * the plugins might wanna expose some paths on the bus. However the
741 * best order of how to init various subsystems of the Bluetooth
742 * daemon needs to be re-worked. */
743 plugin_init(option_plugin, option_noplugin);
744
745 /* no need to keep parsed option in memory */
746 free_options();
747 /*rfkill驱动，默认没有*/
748 rfkill_init();
749
750 DBG("Entering main loop");
751
752 sd_notify(0, "STATUS=Running");
753 sd_notify(0, "READY=1");
754 /*看门狗*/
755 watchdog_usec = getenv("WATCHDOG_USEC");
756 if (watchdog_usec) {
757 unsigned int seconds;
758
759 seconds = atoi(watchdog_usec) / (1000 * 1000);
760 info("Watchdog timeout is %d seconds", seconds);
761 /*定时喂狗*/
762 watchdog = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
763 seconds / 2,
764 watchdog_callback,
765 NULL, NULL);
766 } else
767 watchdog = 0;
768 /*进入循环，处理事件消息*/
769 g_main_loop_run(event_loop);至此，bluetoothd启动完成