hdw-sniff.c

   1 /*
   2  * hdw-sniff, sniffer using pcap lib
   3  *
   4  * author: hackbard@hackdaworld.dyndns.org
   5  */
   6
   7 #include <stdio.h>
   8 #include <pcap.h>
   9
  10 /* IEEE 802.3 stuff -- i will concentrate on .11 stuff before! */
  11 #include <netinet/if_ether.h>
  12 #include <netinet/ip.h> /* ip */
  13 #include <netinet/in.h> /* in_addr */
  14
  15 /* IEEE 802.11 stuff -- will become one include later ... */
  16 #include "ieee80211.h" /* from hunz's aeolus, short hostap_wlan.h */
  17 #include "ieee802_11.h" /* from pcmcia-cs */
  18
  19 #include "hdw-sniff.h" /* my functions */
  20
  21 #define MAX_PACKAGES 3
  22
  23 int main(int argc, char *argv[]) {
  24
  25         int i,count;
  26         char pcap_error[PCAP_ERRBUF_SIZE];
  27         pcap_t *pcap_handle;
  28         const u_char *package;
  29         struct pcap_pkthdr pcap_header;
  30         struct ethhdr *e_hdr;
  31         struct ip *ip_hdr;
  32         struct ieee802_11_hdr *w_hdr;
  33
  34         /* parse the arguments */
  35         if(argc<2) {
  36                 printf("usage: %s <interface> <logfile>\n",argv[0]);
  37                 return 0;
  38         }
  39         if(argc!=3) {
  40                 printf("no logfile specified, writing to stdout ...\n");
  41         }
  42
  43         /* start pcap session */
  44         pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
  45         if(pcap_handle==NULL) {
  46                 printf("%s: %s\n",argv[0],pcap_error);
  47                 return 1;
  48         }
  49
  50         /* grab a package until user breaks */
  51         count=0;
  52         while (count<MAX_PACKAGES) {
  53         count++;
  54         printf("\n");
  55         if((package=pcap_next(pcap_handle,&pcap_header))!=NULL) {
  56                 printf("---> package %d ---- %s",count,
  57                                 ctime((const time_t*)&pcap_header.ts.tv_sec));
  58                 printf("pcap header: ");
  59                 printf("capture length=%d ",pcap_header.caplen);
  60                 printf("length(off wire)=%d\n",pcap_header.len);
  61         }
  62
  63         /* is ieee802.11 ? -- we assume yes :) */
  64         /* ...                                  */
  65
  66
  67         /* ieee802.3 */
  68         /* ethernet */
  69         e_hdr=(struct ethhdr *)package;
  70         /* what types ? */
  71         printf("type = ");
  72         printf("%x  ",ntohs(e_hdr->h_proto));
  73         printf("dest_addr = ");
  74         for(i=0;i<ETH_ALEN;i++)
  75         printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
  76         printf(" src_addr = ");
  77         for(i=0;i<ETH_ALEN;i++)
  78         printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
  79                 /* IP ? */
  80         if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
  81                 printf("ip protocol: ");
  82                 ip_hdr=(struct ip *)(package+sizeof(struct ethhdr));
  83                 printf("version = %x ",ntohs(ip_hdr->ip_v));
  84                 printf("header_length = %x \n",ntohs(ip_hdr->ip_hl));
  85                 printf("service = %x ",ntohs(ip_hdr->ip_tos));
  86                 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->ip_len));
  87                 printf("ip_addresses: source = ");
  88                 printf("%s\tdestination = %s\n",inet_ntoa(ip_hdr->ip_src),
  89                                                 inet_ntoa(ip_hdr->ip_dst));
  90
  91
  92         }
  93         printf("all_hex_dump:\n");
  94         for(i=sizeof(struct ethhdr);i<pcap_header.caplen;i++)
  95                 printf("%x ",*(package+i));
  96         printf("\n");
  97         }
  98         printf("\n");
  99         printf("wake up early! :)\n");
 100         printf("\n");
 101 }