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
  13 /* IEEE 802.11 stuff -- will become one include later ... */
  14 #include "ieee80211.h" /* from hunz's aeolus, short hostap_wlan.h */
  15 #include "ieee802_11.h" /* from pcmcia-cs */
  16
  17 #include "hdw-sniff.h" /* my functions */
  18
  19 int main(int argc, char *argv[]) {
  20
  21         int i;
  22         char pcap_error[PCAP_ERRBUF_SIZE];
  23         pcap_t *pcap_handle;
  24         const u_char *package;
  25         struct pcap_pkthdr pcap_header;
  26         struct ethhdr *e_hdr;
  27         struct ieee802_11_hdr *w_hdr;
  28
  29         /* parse the arguments */
  30         if(argc<2) {
  31                 printf("usage: %s <interface> <logfile>\n",argv[0]);
  32                 return 0;
  33         }
  34         if(argc!=3) {
  35                 printf("no logfile specified, writing to stdout ...\n");
  36         }
  37
  38         /* start pcap session */
  39         pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
  40         if(pcap_handle==NULL) {
  41                 printf("%s: %s\n",argv[0],pcap_error);
  42                 return 1;
  43         }
  44
  45         /* grab a package until user breaks */
  46         while (1) {
  47         printf("\n");
  48
  49         printf("----| new package |----| hdw - sniff |----\n");
  50         if((package=pcap_next(pcap_handle,&pcap_header))!=NULL) {
  51                 printf("package received at: %s",
  52                         ctime((const time_t*)&pcap_header.ts.tv_sec));
  53                 printf("pcap header: ");
  54                 printf("capture length=%d ",pcap_header.caplen);
  55                 printf("length(off wire)=%d\n",pcap_header.len);
  56         }
  57
  58         /* 802.11 or 802.3 -- not quite sure about 'D' & '\0' */
  59         if(*package=='D') {
  60                 printf("ieee802.11: ");
  61         }
  62         else if(*package=='\0') {
  63                 printf("ethernet: ");
  64                 /* reading ethernet header */
  65                 e_hdr=(struct ethhdr *)package;
  66                 /* what types ? */
  67                 printf("types = ");
  68                 // for(i=0;i<2;i++)
  69                 printf("%x %x\n",
  70                         /* i==0?"0x":" ", */
  71                         *(e_hdr->h_proto)
  72                         /* i==1?"\n":"" */
  73                 );
  74                 printf("dest_addr = ");
  75                 for(i=0;i<ETH_ALEN;i++)
  76                 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
  77                 printf(" src_addr = ");
  78                 for(i=0;i<ETH_ALEN;i++)
  79                 printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
  80                 printf("rest:\n");
  81                 for(i=sizeof(struct ethhdr);i<pcap_header.caplen;i++)
  82                         printf("%x ",*(package+i));
  83                 printf("\n");
  84         }
  85         else {
  86                 printf("unknown: ");
  87                 /* print the whole package in hex */
  88                 for(i=0;i<=pcap_header.caplen;i++) printf("%x ",*(package+i));
  89                 printf("\n");
  90                 printf("%c <- identifier for unknown!\n",*package);
  91         }
  92         }
  93         printf("just beacon frames, ha? - wake up early! :)");
  94 }