How to pragmatically retrieve connected Access Point Info in Linux

Question

I am looking for a sample code in C++ which retrieves connected Access Point Info in Linux.

Similar feature is provided by WifiManager.GetConnectionInfo API in Android which returns BSSID,SSID,SignalStrength and other parameters for a connected AccesPoint in a android device.

Do we have any Wifi system API's available in LINUX like Windows?

The below post suggests usage of cfg80211, but I am not getting how to use this. http://www.linuxwireless.org/en/developers/Documentation/cfg80211/

Answer 1

please refer below mention function which will print the MAC address and Network SSID of the connected Access Point.

char *
get_essid (char *iface)
{
   int           fd;
   struct iwreq  w;
   char          essid[IW_ESSID_MAX_SIZE];

   if (!iface) return NULL;

   fd = socket(AF_INET, SOCK_DGRAM, 0);
   printf("Socket desc is: %d\n", fd);

   if(fd <0)
   {
    printf("Socket failed: %d", fd);
   }

   strncpy (w.ifr_ifrn.ifrn_name, iface, IFNAMSIZ);
   memset (essid, 0, IW_ESSID_MAX_SIZE);
   w.u.essid.pointer = (caddr_t *) essid;
   w.u.data.length = IW_ESSID_MAX_SIZE;
   w.u.data.flags = 0;

   int ret = ioctl (fd, SIOCGIWESSID, &w);
   printf("ioctl ret is : %d\n", ret);

   ret = ioctl (fd, SIOCGIFHWADDR, &w);
   printf("ioctl ap details ret is : %d\n", ret);

   //get HWaddr
   u_int8_t hd[6];


        memcpy(hd,w.u.ap_addr.sa_data,sizeof(hd));
    int i=0;
    printf("HWaddr:");
    for(i;i<6;i++)
    {
        printf("%02X:",hd[i]);
    }

   close (fd);


   return strdup (essid);
}