首先介绍一下和inquiry的相关的流程。
inquiry是从协议栈下发的一个HCI命令。其格式如下：
这里简单介绍下第二个参数，是inquiry的持续时间，
从上图看出 inquiry持续的时间是 设定值乘以1.28s，如果设定值是10，那么实际持续的时间就是12.8s
那么下了这个HCI命令之后，控制器端上传的event是什么呢？这个要看另外一个命令：HCI_Write_Inquiry_mode
我们主要关注一下其中的inquiry mode
根据这个设定值，我们知道controller 可能会上传event的类型。假如mode = 0x02，那么controller上传的event的类型就可能是Inquiry Result with RSSI format or Extended Inquiry Result format ，如果mode = 1，那么上传的event只能是Inquiry Result format with RSSI。
那Inquiry Result with RSSI format 和 Extended Inquiry Result format有什么区别呢？唯一的区别就是后者比前者多了一个extended inquiry response的数据域。
下面进入到 对于Inquiry Result with RSSI format 和 Extended Inquiry Result format 的代码处理流程的分析：
void btu_hcif_process_event (UNUSED_ATTR UINT8 controller_id, BT_HDR *p_msg)
{
UINT8 *p = (UINT8 *)(p_msg + ) + p_msg->offset;
UINT8 hci_evt_code, hci_evt_len;
#if BLE_INCLUDED == TRUE
UINT8 ble_sub_code;
#endif
STREAM_TO_UINT8 (hci_evt_code, p);
STREAM_TO_UINT8 (hci_evt_len, p); switch (hci_evt_code)
{
case HCI_INQUIRY_COMP_EVT:
btu_hcif_inquiry_comp_evt (p);
break;
case HCI_INQUIRY_RESULT_EVT:
btu_hcif_inquiry_result_evt (p);
break;
case HCI_INQUIRY_RSSI_RESULT_EVT:
btu_hcif_inquiry_rssi_result_evt (p);
break;
case HCI_EXTENDED_INQUIRY_RESULT_EVT:
btu_hcif_extended_inquiry_result_evt (p);
break;
...
上面介绍的三种mode，都是调用同一个处理函数，只是传入的参数不同， 我们发现HCI_EXTENDED_INQUIRY_RESULT_EVT流程涵盖了HCI_INQUIRY_RSSI_RESULT_EVT 的流程。
我们只分析：HCI_EXTENDED_INQUIRY_RESULT_EVT的流程
static void btu_hcif_inquiry_rssi_result_evt (UINT8 *p)
{
/* Store results in the cache */
btm_process_inq_results (p, BTM_INQ_RESULT_WITH_RSSI);
}
继续看btm_process_inq_results的流程：
/*******************************************************************************
**
** Function btm_process_inq_results
**
** Description This function is called when inquiry results are received from
** the device. It updates the inquiry database. If the inquiry
** database is full, the oldest entry is discarded.
**
** Parameters inq_res_mode - BTM_INQ_RESULT_STANDARD
** BTM_INQ_RESULT_WITH_RSSI
** BTM_INQ_RESULT_EXTENDED
**
** Returns void
**
*******************************************************************************/
void btm_process_inq_results (UINT8 *p, UINT8 inq_res_mode)
{
UINT8 num_resp, xx;
BD_ADDR bda;
tINQ_DB_ENT *p_i;
tBTM_INQ_RESULTS *p_cur=NULL;
BOOLEAN is_new = TRUE;
BOOLEAN update = FALSE;
INT8 i_rssi;
tBTM_INQUIRY_VAR_ST *p_inq = &btm_cb.btm_inq_vars;
tBTM_INQ_RESULTS_CB *p_inq_results_cb = p_inq->p_inq_results_cb;
UINT8 page_scan_rep_mode = ;
UINT8 page_scan_per_mode = ;
UINT8 page_scan_mode = ;
UINT8 rssi = ;
DEV_CLASS dc;
UINT16 clock_offset;
UINT8 *p_eir_data = NULL;
...
STREAM_TO_UINT8 (num_resp, p);//解析出num_resp for (xx = ; xx < num_resp; xx++)//依次处理，一般只有一个
{
update = FALSE;//初始化位false
/* Extract inquiry results */
STREAM_TO_BDADDR (bda, p);//解析出地址等
STREAM_TO_UINT8 (page_scan_rep_mode, p);
STREAM_TO_UINT8 (page_scan_per_mode, p); if (inq_res_mode == BTM_INQ_RESULT_STANDARD)
{
STREAM_TO_UINT8(page_scan_mode, p);
} STREAM_TO_DEVCLASS (dc, p);//解析device class
STREAM_TO_UINT16 (clock_offset, p);
if (inq_res_mode != BTM_INQ_RESULT_STANDARD)
{
STREAM_TO_UINT8(rssi, p);//stand 没有rssi
} p_i = btm_inq_db_find (bda);//查找数据库，后续会判断是否已经处理过
...
/* Check if this address has already been processed for this inquiry */
if (btm_inq_find_bdaddr(bda))// true 说明已经处理过，check是否要update
{
i_rssi = (INT8)rssi;
/* If this new RSSI is higher than the last one */
if(p_inq->inqparms.report_dup && (rssi != ) &&
p_i && (i_rssi > p_i->inq_info.results.rssi || p_i->inq_info.results.rssi ==
#if BLE_INCLUDED == TRUE
/* BR/EDR inquiry information update */
|| (p_i->inq_info.results.device_type & BT_DEVICE_TYPE_BREDR) !=
#endif
))
{
p_cur = &p_i->inq_info.results;
BTM_TRACE_DEBUG("update RSSI new:%d, old:%d", i_rssi, p_cur->rssi);
p_cur->rssi = i_rssi;
update = TRUE;
}
/* If we received a second Extended Inq Event for an already */
/* discovered device, this is because for the first one EIR was not received */
else if ((inq_res_mode == BTM_INQ_RESULT_EXTENDED) && (p_i))
{
p_cur = &p_i->inq_info.results;
update = TRUE;
}
/* If no update needed continue with next response (if any) */
else
continue;
} /* If existing entry, use that, else get a new one (possibly reusing the oldest) */
if (p_i == NULL)
{
p_i = btm_inq_db_new (bda);//新建数据库
is_new = TRUE;
} /* If an entry for the device already exists, overwrite it ONLY if it is from
a previous inquiry. (Ignore it if it is a duplicate response from the same
inquiry.
*/
else if (p_i->inq_count == p_inq->inq_counter //相等说明是本次inquiry
#if (BLE_INCLUDED == TRUE )
&& (p_i->inq_info.results.device_type == BT_DEVICE_TYPE_BREDR)
#endif
)
is_new = FALSE;//不是新的 /* keep updating RSSI to have latest value */
if( inq_res_mode != BTM_INQ_RESULT_STANDARD )//如果不是标准模式，rssi每次都要更新
p_i->inq_info.results.rssi = (INT8)rssi;
else
p_i->inq_info.results.rssi = BTM_INQ_RES_IGNORE_RSSI; if (is_new == TRUE)//如果是新设备，那么保存这些信息
{
/* Save the info */
p_cur = &p_i->inq_info.results;
p_cur->page_scan_rep_mode = page_scan_rep_mode;
p_cur->page_scan_per_mode = page_scan_per_mode;
p_cur->page_scan_mode = page_scan_mode;
p_cur->dev_class[] = dc[];
p_cur->dev_class[] = dc[];
p_cur->dev_class[] = dc[];
p_cur->clock_offset = clock_offset | BTM_CLOCK_OFFSET_VALID; p_i->time_of_resp = GKI_get_os_tick_count();//获取时间，用以计算最老的item if (p_i->inq_count != p_inq->inq_counter)
p_inq->inq_cmpl_info.num_resp++; /* A new response was found */ #if (defined BLE_INCLUDED && BLE_INCLUDED == TRUE)
p_cur->inq_result_type = BTM_INQ_RESULT_BR;
if (p_i->inq_count != p_inq->inq_counter)
{
p_cur->device_type = BT_DEVICE_TYPE_BREDR;
p_i->scan_rsp = FALSE;
}
else
p_cur->device_type |= BT_DEVICE_TYPE_BREDR;
#endif
p_i->inq_count = p_inq->inq_counter; /* Mark entry for current inquiry */
...
/* Initialize flag to FALSE. This flag is set/used by application */
p_i->inq_info.appl_knows_rem_name = FALSE;//初始化位false
}
if (is_new || update)
{
if( inq_res_mode == BTM_INQ_RESULT_EXTENDED )
{
memset( p_cur->eir_uuid, ,
BTM_EIR_SERVICE_ARRAY_SIZE * (BTM_EIR_ARRAY_BITS/));
/* set bit map of UUID list from received EIR */
btm_set_eir_uuid( p, p_cur );//将UUID list保存在tBTM_INQ_RESULTS->eir_uuid中
p_eir_data = p;
}
else
p_eir_data = NULL; /* If a callback is registered, call it with the results */
if (p_inq_results_cb)//调用回调
(p_inq_results_cb)((tBTM_INQ_RESULTS *) p_cur, p_eir_data);
}
}
}
上面的流程比较简单，主要就是保存inquiry回来的信息，然后调用p_inq_results_cb 来处理 设备信息。这个在BTM_StartInquiry的时候传入参数bta_dm_inq_results_cb，调用的也就是这个回调函数。下面继续分析bta_dm_inq_results_cb
/*******************************************************************************
**
** Function bta_dm_inq_results_cb
**
** Description Inquiry results callback from BTM
**
** Returns void
**
*******************************************************************************/
static void bta_dm_inq_results_cb (tBTM_INQ_RESULTS *p_inq, UINT8 *p_eir)
{ tBTA_DM_SEARCH result;
tBTM_INQ_INFO *p_inq_info;
UINT16 service_class; bdcpy(result.inq_res.bd_addr, p_inq->remote_bd_addr);
memcpy(result.inq_res.dev_class, p_inq->dev_class, DEV_CLASS_LEN);
BTM_COD_SERVICE_CLASS(service_class, p_inq->dev_class);
result.inq_res.is_limited = (service_class & BTM_COD_SERVICE_LMTD_DISCOVER)?TRUE:FALSE;
result.inq_res.rssi = p_inq->rssi; #if (BLE_INCLUDED == TRUE)
result.inq_res.ble_addr_type = p_inq->ble_addr_type;
result.inq_res.inq_result_type = p_inq->inq_result_type;
result.inq_res.device_type = p_inq->device_type;
result.inq_res.flag = p_inq->flag;
#endif /* application will parse EIR to find out remote device name */
result.inq_res.p_eir = p_eir; if((p_inq_info = BTM_InqDbRead(p_inq->remote_bd_addr)) != NULL)
{
/* initialize remt_name_not_required to FALSE so that we get the name by default */
result.inq_res.remt_name_not_required = FALSE; } if(bta_dm_search_cb.p_search_cback)
bta_dm_search_cb.p_search_cback(BTA_DM_INQ_RES_EVT, &result);//上层会去解析，并且会设置是否知晓名字的标志位 if(p_inq_info)
{
/* application indicates if it knows the remote name, inside the callback
copy that to the inquiry data base*/
if(result.inq_res.remt_name_not_required)
p_inq_info->appl_knows_rem_name = TRUE;//将标志位位传递到数据库 } }
上面的逻辑很简单，就是组建了一个 tBTA_DM_SEARCH 然后继续向上层汇报 事件。
我们继续看bta_dm_search_cb.p_search_cback 的流程，我们已经多次分析：bta_dm_search_cb.p_search_cback = bte_search_devices_evt
/*******************************************************************************
**
** Function bte_search_devices_evt
**
** Description Switches context from BTE to BTIF for DM search events
**
** Returns void
**
*******************************************************************************/
static void bte_search_devices_evt(tBTA_DM_SEARCH_EVT event, tBTA_DM_SEARCH *p_data)
{
UINT16 param_len = ; if (p_data)
param_len += sizeof(tBTA_DM_SEARCH);
/* Allocate buffer to hold the pointers (deep copy). The pointers will point to the end of the tBTA_DM_SEARCH */
switch (event)
{
case BTA_DM_INQ_RES_EVT:
{
if (p_data->inq_res.p_eir)
param_len += HCI_EXT_INQ_RESPONSE_LEN;
}
break;
...
/* if remote name is available in EIR, set teh flag so that stack doesnt trigger RNR */
if (event == BTA_DM_INQ_RES_EVT){
p_data->inq_res.remt_name_not_required = check_eir_remote_name(p_data, NULL, NULL);//解析EIRdata中的名字并设置标志位
}
btif_transfer_context (btif_dm_search_devices_evt , (UINT16) event, (void *)p_data, param_len,
(param_len > sizeof(tBTA_DM_SEARCH)) ? search_devices_copy_cb : NULL);//transfer 到btif 线程-->btif_dm_search_devices_evt
}
我们继续看btif_dm_search_devices_evt
/******************************************************************************
**
** Function btif_dm_search_devices_evt
**
** Description Executes search devices callback events in btif context
**
** Returns void
**
******************************************************************************/
static void btif_dm_search_devices_evt (UINT16 event, char *p_param)
{
tBTA_DM_SEARCH *p_search_data;
BTIF_TRACE_EVENT("%s event=%s", __FUNCTION__, dump_dm_search_event(event)); switch (event)
{
...
case BTA_DM_INQ_RES_EVT:
{
/* inquiry result */
UINT32 cod;
bt_bdname_t bdname;
bt_bdaddr_t bdaddr;
UINT8 remote_name_len;
tBTA_SERVICE_MASK services = ;
bdstr_t bdstr; p_search_data = (tBTA_DM_SEARCH *)p_param;
bdcpy(bdaddr.address, p_search_data->inq_res.bd_addr); #if (BLE_INCLUDED == TRUE)
p_search_data->inq_res.device_type);
#else
BT_DEVICE_TYPE_BREDR);
#endif
bdname.name[] = ; cod = devclass2uint (p_search_data->inq_res.dev_class);
...
if (!check_eir_remote_name(p_search_data, bdname.name, &remote_name_len))//解析名字
check_cached_remote_name(p_search_data, bdname.name, &remote_name_len); /* Check EIR for remote name and services */
if (p_search_data->inq_res.p_eir)
{
BTA_GetEirService(p_search_data->inq_res.p_eir, &services);
BTIF_TRACE_DEBUG("%s()EIR BTA services = %08X", __FUNCTION__, (UINT32)services);
/* TODO: Get the service list and check to see which uuids we got and send it back to the client. */
} {
bt_property_t properties[];
bt_device_type_t dev_type;
uint32_t num_properties = ;
bt_status_t status;
int addr_type = ; memset(properties, , sizeof(properties));
/* BD_ADDR */
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_BDADDR, sizeof(bdaddr), &bdaddr);
num_properties++;
/* BD_NAME */
/* Don't send BDNAME if it is empty */
if (bdname.name[])
{
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_BDNAME,
strlen((char *)bdname.name), &bdname);
num_properties++;
} /* DEV_CLASS */
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_CLASS_OF_DEVICE, sizeof(cod), &cod);
num_properties++;
/* DEV_TYPE */
#if (defined(BLE_INCLUDED) && (BLE_INCLUDED == TRUE))
/* FixMe: Assumption is that bluetooth.h and BTE enums match */ /* Verify if the device is dual mode in NVRAM */
int stored_device_type = ;
if (btif_get_device_type(bdaddr.address, &stored_device_type) &&
((stored_device_type == BT_DEVICE_TYPE_BLE &&
p_search_data->inq_res.device_type == BT_DEVICE_TYPE_BREDR) ||
(stored_device_type == BT_DEVICE_TYPE_BREDR &&
p_search_data->inq_res.device_type == BT_DEVICE_TYPE_BLE))) {
dev_type = BT_DEVICE_TYPE_DUMO;
} else {
dev_type = p_search_data->inq_res.device_type;
} if (p_search_data->inq_res.device_type == BT_DEVICE_TYPE_BLE)
addr_type = p_search_data->inq_res.ble_addr_type;
#else
dev_type = BT_DEVICE_TYPE_BREDR;
#endif
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_TYPE_OF_DEVICE, sizeof(dev_type), &dev_type);
num_properties++;
/* RSSI */
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_REMOTE_RSSI, sizeof(int8_t),
&(p_search_data->inq_res.rssi));
num_properties++; #ifdef BLUETOOTH_RTK
BTIF_STORAGE_FILL_PROPERTY(&properties[num_properties],
BT_PROPERTY_REMOTE_VERSION_INFO, sizeof(bt_remote_version_t),
&info);
num_properties++;
#endif status = btif_storage_add_remote_device(&bdaddr, num_properties, properties);//保存各个属性值到文件系统中
ASSERTC(status == BT_STATUS_SUCCESS, "failed to save remote device (inquiry)", status);
#if (defined(BLE_INCLUDED) && (BLE_INCLUDED == TRUE))
status = btif_storage_set_remote_addr_type(&bdaddr, addr_type);
#endif
/* Callback to notify upper layer of device */
HAL_CBACK(bt_hal_cbacks, device_found_cb,
num_properties, properties);//向上层汇报
}
}
break;
这里注意btif_storage_add_remote_device 是将各个属性保存在系统的配置文件中。
上面的代码和BLE的广播包的处理 如出一辙，都是组装成bt_property_t的形式进行上报，通过HAL_CBACK(bt_hal_cbacks, device_found_cb,num_properties, properties); 来上面五个属性：设备地址、设备名字、设备类、设备类型、设备rssi
那关于BREDR 的inquiry 的数据包处理流程就分析到这里。