6.4客流量统计

本设计利用w800设计出一款可以实时监控公共场所的人流量系统.其中w800提供混杂接收模式接收数据包,并对其解析,筛选得到周围打开Wi-Fi功能设备发送的Probe Request帧,通过对接收到的Probe Request帧分析和汇总,得到周围区域内的设备使用量(人流量)。
w800可进入该sniffer模式，接收空中的 IEEE802.11包，获取周围设备MAC信息，从而估算客流量。

static void sniffer_callback(struct ieee80211_hdr *hdr, u32 data_len,struct tls_wifi_ext_t *ext)
{
if((ieee80211_is_mgmt(hdr->frame_control) != 0))
{
static u8 last_sa_addr_data[6] = {0};
static u8 last_da_addr_data[6] = {0};
u8 *curr_sa_addr_data = NULL;
u8 *curr_da_addr_data = NULL;

    u8 data_diff = FALSE;


    char addr[] = "00:00:00:00:00:00";
    curr_sa_addr_data = ieee80211_get_SA(hdr);
    curr_da_addr_data = ieee80211_get_DA(hdr);

    for(int i=0; i< 6; i++)
    {
        if(*(curr_sa_addr_data + i) != *(last_sa_addr_data +i))
        {
            data_diff = TRUE;
            if(data_diff ==TRUE)
            {
            	count++;
            	 tls_os_time_delay(8000);
            	data_diff = FALSE;

            }


            break;
        }

        if(*(curr_da_addr_data + i) != *(last_da_addr_data +i))
        {
        	data_diff = TRUE;

            break;
        }
    }

    if((data_diff) && ((hdr->frame_control & IEEE80211_FCTL_RETRY) == 0))
    {

        memcpy((u8 *)last_sa_addr_data, curr_sa_addr_data, 6);
        memcpy((u8 *)last_da_addr_data, curr_da_addr_data, 6);

        sprintf(addr, "%02X:%02X:%02X:%02X:%02X:%02X", *curr_sa_addr_data, *(curr_sa_addr_data+1), *(curr_sa_addr_data+2), *(curr_sa_addr_data+3), *(curr_sa_addr_data+4), *(curr_sa_addr_data+5));
        printf("%s|", addr);
        printf("count:\r\n%d\r\n", count);

    }
}

}
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