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 <string.h>
   9 #include <stdlib.h>
  10 #include <sys/socket.h>
  11 #include <time.h>
  12 #include <netinet/in.h>
  13 #include <arpa/inet.h>
  14 #include <pcap.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17 #include <sys/ioctl.h>
  18
  19 /* IEEE 802.3 stuff -- i will concentrate on .11 stuff before! */
  20 #include <netinet/if_ether.h>  /* for ethhdr struct */
  21 #include <netinet/ip.h> /* ip */
  22 #include <netinet/in.h> /* in_addr , inet_ntoa */
  23
  24 /* IEEE 802.11 stuff -- will become one include later ... */
  25 #include "ieee80211.h" /* from hunz's aeolus, short hostap_wlan.h */
  26 #include "ieee802_11.h" /* from pcmcia-cs */
  27
  28 #include "hdw-sniff.h" /* my functions */
  29
  30 int main(int argc, char *argv[]) {
  31
  32         char pcap_error[PCAP_ERRBUF_SIZE];
  33         pcap_t *pcap_handle;
  34         int pcap_fd;
  35         fd_set pcap_fd_set;
  36         struct timeval fd_set_tv;
  37         char sys_call[30];
  38         FILE *logfile;
  39         struct info_struct my_info_struct;
  40
  41         /* parse the arguments */
  42         if(argc<3) {
  43                 printf("usage: %s <interface> <monitor mode> <logfile>\n",
  44                         argv[0]);
  45                 return 0;
  46         }
  47         if(argc!=4) {
  48                 printf("no logfile specified, writing to stdout ...\n");
  49         }
  50         else {
  51                 if((logfile=fopen(argv[3],"w"))!=NULL) {
  52                         printf("writing to logfile %s ...\n",argv[3]);
  53                 }
  54                 else {
  55                         printf("can't open logfile!\n");
  56                 }
  57         }
  58
  59         /* setting up device and set monitor mode */
  60         if(atoi(argv[2])==1) {
  61                 printf("setting to monitor mode\n");
  62                 if(strncmp(argv[1],"wlan",4)==0)
  63                         sprintf(sys_call,"iwpriv %s monitor 3",argv[1]);
  64                 if(strncmp(argv[1],"eth",3)==0)
  65                         sprintf(sys_call,"ifconfig %s promisc",argv[1]);
  66         system(sys_call);
  67         }
  68         printf("setting up interface\n");
  69         sprintf(sys_call,"ifconfig %s up",argv[1]);
  70         system(sys_call);
  71
  72         /* start pcap session */
  73         pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
  74         if(pcap_handle==NULL) {
  75                 printf("%s: %s\n",argv[0],pcap_error);
  76                 return 1;
  77         }
  78
  79         /* set non blocking */
  80         if((pcap_setnonblock(pcap_handle,1,pcap_error))==-1) {
  81                 printf("%s: %s\n",argv[0],pcap_error);
  82                 return 1;
  83         }
  84
  85         /* grab a package until user breaks */
  86         my_info_struct.count=0;
  87         my_info_struct.mmode=argv[2][0];
  88         strcpy(my_info_struct.dev,argv[1]);
  89
  90         /* prepare for select */
  91         pcap_fd=pcap_fileno(pcap_handle);
  92         FD_ZERO(&pcap_fd_set);
  93         FD_SET(pcap_fd,&pcap_fd_set);
  94         fd_set_tv.tv_sec=0;
  95         fd_set_tv.tv_usec=500000;
  96
  97         /* do loopp */
  98         while(1) {
  99                 if((select(pcap_fd+1,&pcap_fd_set,NULL,NULL,&fd_set_tv)) && (FD_ISSET(pcap_fd,&pcap_fd_set))) pcap_loop(pcap_handle,-1,pcap_process,(u_char *)&my_info_struct);
 100                 else if((hop_channel(&my_info_struct,pcap_fd))==-1) {
 101                         printf("channelhopping failed, aborting\n");
 102                         return -1;
 103                 }
 104         }
 105         return 0;
 106 }
 107
 108
 109 /* pcap_process callback function */
 110 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
 111                         const u_char *package) {
 112
 113         /* local variables */
 114         struct linux_wlan_ng_prism_hdr *prism_hdr;
 115         struct ieee802_11_hdr *w_hdr;
 116         struct ip *ip_hdr;
 117         struct ethhdr *e_hdr;
 118         struct info_struct *my_info_struct;
 119         int i;
 120
 121         my_info_struct=(struct info_struct *)info;
 122         ++(my_info_struct->count);
 123
 124         printf("\n");
 125         printf("---> package %d ---- %s",my_info_struct->count,
 126                         ctime((const time_t*)&(pcap_header->ts.tv_sec)));
 127         printf("pcap header:\n");
 128         printf("capture_length: %d (dec.)\t",pcap_header->caplen);
 129         printf("length(off wire): %d (dec.)\n",pcap_header->len);
 130
 131         /* prism wlan ng headers */
 132         if((my_info_struct->mmode-0x30==1) &&
 133                 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
 134         printf("prism header:\n");
 135         prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
 136         printf("message code/length: %d/%d\n",ntohs(prism_hdr->msgcode),
 137                                                 ntohs(prism_hdr->msglen));
 138         printf("device: %s\n",prism_hdr->devname);
 139
 140         /* ieee802.11 header */
 141         printf("ieee802.11 header:\n");
 142         package+=sizeof(struct linux_wlan_ng_prism_hdr);
 143         w_hdr=(struct ieee802_11_hdr *)package;
 144
 145         printf("debug:\n");
 146         for(i=0;i<16;i++) {
 147                 printf("%x -> ",1<<i);
 148                 printf("%x\n",(ntohs(w_hdr->frame_ctl) & (1<<i)));
 149         }
 150         printf("frame_control: %x duration_id: %x\n",ntohs(w_hdr->frame_ctl),
 151                                                 ntohs(w_hdr->duration_id));
 152         printf("version check ... %s\n",
 153         ((ntohs(w_hdr->frame_ctl) & IEEE802_11_FCTL_VERS)==0x00)?
 154                                                         "ok":"unknown");
 155         // printf("type:
 156         /* skip ieee802.11 header */
 157         package=package+sizeof(struct ieee802_11_hdr);
 158         }
 159
 160         /* ieee802.3 */
 161         /* ethernet */
 162         e_hdr=(struct ethhdr *)package;
 163         /* what types ? */
 164         printf("type = ");
 165         printf("%x  ",ntohs(e_hdr->h_proto));
 166         printf("dest_addr = ");
 167         for(i=0;i<ETH_ALEN;i++)
 168         printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
 169         printf(" src_addr = ");
 170         for(i=0;i<ETH_ALEN;i++)
 171         printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
 172                 /* IP ? */
 173         if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
 174                 printf("ip protocol: ");
 175                 ip_hdr=(struct ip *)(package+sizeof(struct ethhdr));
 176                 printf("version = %x ",ntohs(ip_hdr->ip_v));
 177                 printf("header_length = %x \n",ntohs(ip_hdr->ip_hl));
 178                 printf("service = %x ",ntohs(ip_hdr->ip_tos));
 179                 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->ip_len));
 180                 printf("ip_addresses: source = ");
 181                 printf("%s\tdestination = %s\n",inet_ntoa(ip_hdr->ip_src),
 182                                                 inet_ntoa(ip_hdr->ip_dst));
 183                 printf("ip_id = %x ",ntohs(ip_hdr->ip_id));
 184                 printf("ip_offset = %x \n",ntohs(ip_hdr->ip_off));
 185                 printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ip_ttl),
 186                                                 ntohs(ip_hdr->ip_p));
 187                 printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
 188         }
 189         printf("all_hex_dump:\n");
 190         for(i=sizeof(struct ethhdr);i<pcap_header->caplen;i++)
 191                 printf("%x ",*(package+i));
 192         printf("\n");
 193 }
 194
 195 int hop_channel(struct info_struct *info,int pcap_fd) {
 196         struct iwreq my_iwreq;
 197         int foo_fd;
 198         /* oder vielleicht doch pcap_fd ? */
 199         if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
 200                 printf("unable to create socket\n");
 201                 return -1;
 202         }
 203
 204         if (info->channel==15) info->channel=1;
 205
 206         memset(&my_iwreq,0,sizeof(my_iwreq));
 207         strcpy(my_iwreq.ifr_name,info->dev);
 208         printf("debug: device = %s\n",my_iwreq.ifr_name);
 209         my_iwreq.u.freq.e=0;
 210         my_iwreq.u.freq.m=info->channel;
 211         // if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
 212         if((ioctl(pcap_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
 213                 printf("unable to hop channels\n");
 214                 perror("ioctl");
 215                 return -1;
 216         }
 217         printf("debug: hopped to channel %d\n",info->channel);
 218         ++(info->channel);
 219         return 0;
 220 }
 221