Wireless Libraries Help

[SBerry]

Guys for a little project I want to implement a wireless network monitor with similar data detail that Airodump and Kismet display. I plan to write this in C or C++. I have already used the windows wireless api to write a windows network monitor similar to wireless zero. What api's or libraries should I be looking at for linux networking dev. Should I be looking at libpcap and libnet etc..??

I would really appreciate some guidance here :)

Thanks in advance

[danathane]

Hello!!
To develop your soft, have a look to libnet, libnids, and libpcap. you should also find some interesting things in the netinet folder. There is a lot of librairy for IP, ethernet and TCP developping.

Bye

[karabaja4]

i'm interested in this too.

it would be really helpful if someone would post an example of C program that lists all of the networks essids/bssids/channels in range.

(dont blame me for no effort, i just dont have time to mess with these things, and it would be really nice if someone has an example to show :D)

[SBerry]

I have code using libpcap that will capture yourself a beacon packet. From that you can get the ssid.

Have a look at this. Using bit field for frame control struct. By the way have a look at the source code for airodump-ng. That might also clear up a few things

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<pcap.h>
#include<errno.h>
#include<arpa/inet.h>
#include<net/ethernet.h>
#include<linux/wireless.h>
#include<netinet/if_ether.h>

typedef struct mac_header{
unsigned char fc[2];
unsigned char id[2];
unsigned char add1[6];
unsigned char add2[6];
unsigned char add3[6];
unsigned char sc[2];
}mac_header;

typedef struct frame_control{
unsigned protocol:2;
unsigned type:2;
unsigned subtype:4;
unsigned to_ds:1;
unsigned from_ds:1;
unsigned more_frag:1;
unsigned retry:1;
unsigned pwr_mgt:1;
unsigned more_data:1;
unsigned wep:1;
unsigned order:1;
}frame_control;

typedef struct beacon_header{
unsigned char timestamp[8];
unsigned char beacon_interval[2];
unsigned char cap_info[2];
}beacon_header;


void packet_decoder (u_char * useless, const struct pcap_pkthdr *pkthdr, const u_char * packet)
{
printf("Got Packet");
char ssid[32], *temp;
struct mac_header *p = (struct mac_header *) packet;
struct frame_control *control = (struct frame_control *) p->fc;
temp = (char *) (packet + sizeof (struct mac_header) +
sizeof (struct beacon_header));
memset (ssid, '\0', 32);
// check if frame is beacon frame
if ((control->protocol == 0) && (control->type == 0)
&& (control->subtype == 8))
{
//temp[1] contains the size of the ssid field and temp[2] the beginning of
//the ssid string .
memcpy (ssid, &temp[2], temp[1]);
printf ("\n\nFound SSID : \n");
printf ("Destination Add : %s\n", ether_ntoa (p->add1));
printf ("Source Add : %s\n", ether_ntoa (p->add2));
printf ("BSSID : %s\n", ether_ntoa (p->add3));
printf ("ssid = %s\n", ssid);
}
}
int main (int argc, char **argv)
{
char *dev = argv[1];
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t *handle;
if (argc < 2)
{
printf ("usage : %s capture_device \n", argv[0]);
exit (1);
}
printf ("Initialising capture interface..");
//pcap initialisation
handle = pcap_open_live (dev, BUFSIZ, 1, -1, errbuf);
if (handle == NULL)
{
printf ("pcap_open_live : %s\n", errbuf);
exit (1);
}
printf ("\nStarting Capture ...........\n");
// tell pcap to pass on captures frames to our packet_decoder fn
pcap_loop (handle, -1, packet_decoder, NULL);
return (0);
}