mgmt接口调用

在bluetoothd启动是，会进行初始化，在这里会获取mgmt句柄来进行和内核之间的通信

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 }

struct mgmt *mgmt_new_default(void)
{struct mgmt *mgmt;union {struct sockaddr common;struct sockaddr_hci hci;} addr;int fd;fd = socket(PF_BLUETOOTH, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,BTPROTO_HCI);    //获取内核蓝牙协议栈句柄if (fd < 0)return NULL;memset(&addr, 0, sizeof(addr));addr.hci.hci_family = AF_BLUETOOTH;addr.hci.hci_dev = HCI_DEV_NONE;addr.hci.hci_channel = HCI_CHANNEL_CONTROL;if (bind(fd, &addr.common, sizeof(addr.hci)) < 0) {   //绑定control通道close(fd);return NULL;}mgmt = mgmt_new(fd);if (!mgmt) {close(fd);return NULL;}mgmt->close_on_unref = true;return mgmt;
}

unsigned int mgmt_send(struct mgmt *mgmt, uint16_t opcode, uint16_t index,uint16_t length, const void *param,mgmt_request_func_t callback,void *user_data, mgmt_destroy_func_t destroy)
{return mgmt_send_timeout(mgmt, opcode, index, length, param, callback,user_data, destroy, 0);
}-->unsigned int mgmt_send_timeout(struct mgmt *mgmt, uint16_t opcode,uint16_t index, uint16_t length,const void *param, mgmt_request_func_t callback,void *user_data, mgmt_destroy_func_t destroy,int timeout)
{struct mgmt_request *request;if (!mgmt)return 0;request = create_request(mgmt, opcode, index, length, param,callback, user_data, destroy, timeout);   //创建请求if (!request)return 0;if (mgmt->next_request_id < 1)mgmt->next_request_id = 1;request->id = mgmt->next_request_id++;if (!queue_push_tail(mgmt->request_queue, request)) {   //如mgmt请求队列free(request->buf);free(request);return 0;}wakeup_writer(mgmt);       //return request->id;
}-->static void wakeup_writer(struct mgmt *mgmt)
{if (!queue_isempty(mgmt->pending_list)) {/* only queued reply commands trigger wakeup */if (queue_isempty(mgmt->reply_queue))return;}if (mgmt->writer_active)return;mgmt->writer_active = true;io_set_write_handler(mgmt->io, can_write_data, mgmt,write_watch_destroy);        //设置写入句柄
}-->static bool can_write_data(struct io *io, void *user_data)
{struct mgmt *mgmt = user_data;struct mgmt_request *request;bool can_write;request = queue_pop_head(mgmt->reply_queue);if (!request) {/* only reply commands can jump the queue */if (!queue_isempty(mgmt->pending_list))return false;request = queue_pop_head(mgmt->request_queue);if (!request)return false;can_write = false;} else {/* allow multiple replies to jump the queue */can_write = !queue_isempty(mgmt->reply_queue);}if (!send_request(mgmt, request))return true;return can_write;
}--->static bool send_request(struct mgmt *mgmt, struct mgmt_request *request)
{struct iovec iov;ssize_t ret;iov.iov_base = request->buf;iov.iov_len = request->len;ret = io_send(mgmt->io, &iov, 1);     //这里到内核层if (ret < 0) {DBG(mgmt, "write failed: %s", strerror(-ret));if (request->callback)request->callback(MGMT_STATUS_FAILED, 0, NULL,request->user_data);destroy_request(request);return false;}if (request->timeout)request->timeout_id = timeout_add_seconds(request->timeout,request_timeout,request,NULL);DBG(mgmt, "[0x%04x] command 0x%04x", request->index, request->opcode);queue_push_tail(mgmt->pending_list, request);return true;
}

内核层处理

初始化mgmt

static struct hci_mgmt_chan chan = {.channel	= HCI_CHANNEL_CONTROL,.handler_count	= ARRAY_SIZE(mgmt_handlers),.handlers	= mgmt_handlers,.hdev_init	= mgmt_init_hdev,
};     //mgmt_handlers这个对应的就是对于上层传递的处理int mgmt_init(void)
{mgmt_chanreturn hci_mgmt_chan_register(&chan);   //注册mgmt_chan
}void mgmt_exit(void)
{hci_mgmt_chan_unregister(&chan);
}//hci_sock.c
int hci_mgmt_chan_register(struct hci_mgmt_chan *c)
{if (c->channel < HCI_CHANNEL_CONTROL)return -EINVAL;mutex_lock(&mgmt_chan_list_lock);if (__hci_mgmt_chan_find(c->channel)) {mutex_unlock(&mgmt_chan_list_lock);return -EALREADY;}list_add_tail(&c->list, &mgmt_chan_list);mutex_unlock(&mgmt_chan_list_lock);return 0;
}
EXPORT_SYMBOL(hci_mgmt_chan_register);