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,foo_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
  93         /* create file descriptor */
  94         if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
  95                 printf("unable to create socket foo_fd\n");
  96                 return -1;
  97         }
  98
  99         /* do loopp */
 100         while (1) {
 101
 102                 /* set pcap_fd */
 103                 FD_ZERO(&pcap_fd_set);
 104                 FD_SET(pcap_fd,&pcap_fd_set);
 105                 fd_set_tv.tv_sec=0;
 106                 fd_set_tv.tv_usec=200000;
 107
 108                 if((select(pcap_fd+1,&pcap_fd_set,NULL,NULL,&fd_set_tv)) && (FD_ISSET(pcap_fd,&pcap_fd_set))) pcap_dispatch(pcap_handle,-1,pcap_process,(u_char *)&my_info_struct);
 109                 else if((hop_channel(&my_info_struct,foo_fd))==-1) {
 110                         printf("channelhopping failed, aborting\n");
 111                         return -1;
 112                 }
 113         }
 114         return 0;
 115 }
 116
 117
 118 /* pcap_process callback function */
 119 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
 120                         const u_char *package) {
 121
 122         /* local variables */
 123         char tmp_buf[20];
 124         struct linux_wlan_ng_prism_hdr *prism_hdr;
 125         struct ieee802_11_hdr *w_hdr;
 126         struct ethhdr *e_hdr;
 127         struct iphdr *ip_hdr;
 128         struct info_struct *my_info_struct;
 129         int i,p_o,w_o,e_o,i_o;
 130
 131         my_info_struct=(struct info_struct *)info;
 132         ++(my_info_struct->count);
 133
 134         /* cache offsets */
 135         p_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct linux_wlan_ng_prism_hdr):0);
 136         w_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct ieee802_11_hdr):0);
 137         e_o=sizeof(struct ethhdr);
 138         i_o=sizeof(struct iphdr);
 139
 140         /* new package */
 141         printf("\n");
 142         printf("---> package %d ---- %s",my_info_struct->count,
 143                         ctime((const time_t*)&(pcap_header->ts.tv_sec)));
 144
 145         /* pcap header */
 146         printf("pcap header: ");
 147         printf("capture_length(dec): %d\t",pcap_header->caplen);
 148         printf("off_wire_length(dec): %d\n",pcap_header->len);
 149
 150         /* wireless stuff */
 151         /* prism wlan ng headers */
 152         if((my_info_struct->mmode-0x30==1) &&
 153                 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
 154         printf("prism header: (%d bytes)\n",p_o);
 155         prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
 156         printf("| message code/length: %d/%d |\t",prism_hdr->msgcode,
 157                                                 prism_hdr->msglen);
 158         printf("device: %s |\n",prism_hdr->devname);
 159         /* ieee802.11 header */
 160         printf("ieee802.11 header: (%d bytes)\n",w_o);
 161         w_hdr=(struct ieee802_11_hdr *)(package+p_o);
 162
 163         printf("fc: ");
 164         for(i=0;i<16;i++)
 165                 printf("%s%d%s",(i==0?"|":""),
 166                                 (((w_hdr->frame_ctl) & (1<<i))>0?1:0),
 167                                 (i==15?"|\n":"|"));
 168         printf("    | v | t |  s-t  |t|f|m|r|p|m|w|o|\n");
 169         /* frame type */
 170         if((w_hdr->frame_ctl & IEEE802_11_STYPE_BEACON)>0)
 171                 strcpy(tmp_buf,"beacon");
 172         if((w_hdr->frame_ctl & IEEE802_11_STYPE_ATIM)>0)
 173                 strcpy(tmp_buf,"announcement traffic indication message");
 174         if((w_hdr->frame_ctl & IEEE802_11_STYPE_DISASSOC)>0)
 175                 strcpy(tmp_buf,"disassociation");
 176         if((w_hdr->frame_ctl & IEEE802_11_STYPE_AUTH)>0)
 177                 strcpy(tmp_buf,"authentification");
 178         if((w_hdr->frame_ctl & IEEE802_11_STYPE_DEAUTH)>0)
 179                 strcpy(tmp_buf,"deauthentification");
 180         if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_REQ)>0)
 181                 strcpy(tmp_buf,"association request");
 182         if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_RESP)>0)
 183                 strcpy(tmp_buf,"association response");
 184         if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_REQ)>0)
 185                 strcpy(tmp_buf,"reassociation request");
 186         if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_RESP)>0)
 187                 strcpy(tmp_buf,"reassociation response");
 188         if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_REQ)>0)
 189                 strcpy(tmp_buf,"probe request");
 190         if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_RESP)>0)
 191                 strcpy(tmp_buf,"probe response");
 192         else strcpy(tmp_buf,"unknown");
 193         /* print out frame type */
 194         printf("=> %s\n",tmp_buf);
 195
 196         printf("duration/id: 0x%x\n",w_hdr->duration_id);
 197         printf("version check ... %s\n",
 198         ((w_hdr->frame_ctl & IEEE802_11_FCTL_VERS)==0x00)?
 199                                                         "ok":"unknown");
 200         }
 201
 202         /* ieee802.3 */
 203         /* ethernet */
 204         if((strncmp(my_info_struct->dev,"eth",3)==0) |
 205                 ((w_hdr->frame_ctl & IEEE802_11_FTYPE_DATA)>0)) {
 206         printf("ethernet: (%d bytes)\n",e_o);
 207         e_hdr=(struct ethhdr *)(package+p_o+w_o);
 208         /* what types ? */
 209         printf("type = ");
 210         printf("%x  ",ntohs(e_hdr->h_proto));
 211         printf("dest_addr = ");
 212         for(i=0;i<ETH_ALEN;i++)
 213         printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
 214         printf(" src_addr = ");
 215         for(i=0;i<ETH_ALEN;i++)
 216         printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
 217
 218                 /* IP ? */
 219         if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
 220                 printf("ip protocol: (%d bytes)\n",i_o);
 221                 ip_hdr=(struct iphdr *)(package+p_o+w_o+e_o);
 222                 printf("version = %x ",ntohs(ip_hdr->version));
 223                 printf("header_length = %x \n",ntohs(ip_hdr->ihl));
 224                 printf("service = %x ",ntohs(ip_hdr->tos));
 225                 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->tot_len));
 226                 printf("source_ip: ");
 227                 for(i=3;i>=0;--i) {
 228                         printf("%d%s",
 229                         ip_hdr->saddr&0xff<<i,
 230                         (i==0?"\n":"."));
 231                 }
 232                 printf("destination_ip: ");
 233                 for(i=3;i>=0;--i) {
 234                         printf("%d%s",
 235                         ip_hdr->daddr&0xff<<i,
 236                         (i==0?"\n":"."));
 237                 }
 238                 printf("ip_id = %x ",ntohs(ip_hdr->id));
 239                 printf("ip_offset = %x \n",ntohs(ip_hdr->frag_off));
 240                 printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ttl),
 241                                                 ntohs(ip_hdr->protocol));
 242                 // printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
 243         }
 244         }
 245
 246         /* check what we have ... */
 247         printf("all dump: (hex)\n");
 248         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 249                 printf("%x ",*(package+i));
 250         printf("\n");
 251         printf("all dump: (char)\n");
 252         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 253                 printf("%c ",*(package+i));
 254         printf("\n");
 255 }
 256
 257 int hop_channel(struct info_struct *info,int foo_fd) {
 258         if((info->mmode-0x30==1) && (strncmp(info->dev,"wlan",4)==0)) {
 259
 260         struct iwreq my_iwreq;
 261
 262         if (info->channel>=14) info->channel=1;
 263
 264         memset(&my_iwreq,0,sizeof(my_iwreq));
 265         strcpy(my_iwreq.ifr_name,info->dev);
 266         printf("debug: channel = %d\n",info->channel);
 267         my_iwreq.u.freq.e=0;
 268         my_iwreq.u.freq.m=info->channel;
 269         if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
 270                 printf("unable to hop channels\n");
 271                 perror("ioctl");
 272                 return -1;
 273         }
 274         ++(info->channel);
 275         }
 276         return 0;
 277 }