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 <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <sys/ioctl.h>
  20
  21 /* IEEE 802.3 stuff -- i will concentrate on .11 stuff before! */
  22 #include <netinet/if_ether.h>  /* for ethhdr struct */
  23 #include <netinet/ip.h> /* ip */
  24 #include <netinet/in.h> /* in_addr , inet_ntoa */
  25
  26 /* IEEE 802.11 stuff -- will become one include later ... */
  27 #include "ieee80211.h" /* from hunz's aeolus, short hostap_wlan.h */
  28 #include "ieee802_11.h" /* from pcmcia-cs */
  29
  30 #include "hdw-sniff.h" /* my functions */
  31
  32 /* global variables */
  33 int file_fd=0;
  34
  35 int main(int argc, char *argv[]) {
  36
  37         char pcap_error[PCAP_ERRBUF_SIZE];
  38         pcap_t *pcap_handle;
  39         int pcap_fd,foo_fd;
  40         fd_set pcap_fd_set;
  41         struct timeval fd_set_tv;
  42         char sys_call[30];
  43         struct info_struct my_info_struct;
  44
  45         /* parse the arguments */
  46         if(argc<3) {
  47                 printf("usage: %s <interface> <monitor mode> <logfile>\n",
  48                         argv[0]);
  49                 return 0;
  50         }
  51         if(argc!=4) {
  52                 printf("no logfile specified, writing to stdout ...\n");
  53         }
  54         else {
  55                 if((file_fd=open(argv[3],O_RDWR))!=0) {
  56                         printf("writing to logfile %s ...\n",argv[3]);
  57                 }
  58                 else {
  59                         printf("can't open logfile!\n");
  60                 }
  61         }
  62
  63         /* setting up device and set monitor mode */
  64         if(atoi(argv[2])==1) {
  65                 printf("setting to monitor mode\n");
  66                 if(strncmp(argv[1],"wlan",4)==0)
  67                         sprintf(sys_call,"iwpriv %s monitor 3",argv[1]);
  68                 if(strncmp(argv[1],"eth",3)==0)
  69                         sprintf(sys_call,"ifconfig %s promisc",argv[1]);
  70         system(sys_call);
  71         }
  72         printf("setting up interface\n");
  73         sprintf(sys_call,"ifconfig %s up",argv[1]);
  74         system(sys_call);
  75
  76         /* start pcap session */
  77         pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
  78         if(pcap_handle==NULL) {
  79                 printf("%s: %s\n",argv[0],pcap_error);
  80                 return 1;
  81         }
  82
  83         /* set non blocking */
  84         if((pcap_setnonblock(pcap_handle,1,pcap_error))==-1) {
  85                 printf("%s: %s\n",argv[0],pcap_error);
  86                 return 1;
  87         }
  88
  89         /* grab a package until user breaks */
  90         my_info_struct.count=0;
  91         my_info_struct.mmode=argv[2][0];
  92         strcpy(my_info_struct.dev,argv[1]);
  93
  94         /* prepare for select */
  95         pcap_fd=pcap_fileno(pcap_handle);
  96
  97         /* create file descriptor */
  98         if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
  99                 printf("unable to create socket foo_fd\n");
 100                 return -1;
 101         }
 102
 103         /* do loopp */
 104         while (1) {
 105
 106                 /* set pcap_fd */
 107                 FD_ZERO(&pcap_fd_set);
 108                 FD_SET(pcap_fd,&pcap_fd_set);
 109                 fd_set_tv.tv_sec=0;
 110                 fd_set_tv.tv_usec=200000;
 111
 112                 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);
 113                 else if((hop_channel(&my_info_struct,foo_fd))==-1) {
 114                         printf("channelhopping failed, aborting\n");
 115                         return -1;
 116                 }
 117         }
 118         return 0;
 119 }
 120
 121
 122 /* pcap_process callback function */
 123 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
 124                         const u_char *package) {
 125
 126         /* local variables */
 127         char tmp_buf[20],crypted_snap[6];
 128         struct linux_wlan_ng_prism_hdr *prism_hdr;
 129         struct ieee802_11_hdr *w_hdr;
 130         struct snaphdr *snap_hdr;
 131         struct ethhdr *e_hdr;
 132         struct iphdr *ip_hdr;
 133         struct info_struct *my_info_struct;
 134         int i,p_o,w_o,e_o,i_o;
 135
 136         my_info_struct=(struct info_struct *)info;
 137         ++(my_info_struct->count);
 138
 139         /* cache offsets */
 140         p_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct linux_wlan_ng_prism_hdr):0);
 141         w_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct ieee802_11_hdr):0);
 142         e_o=sizeof(struct ethhdr);
 143         i_o=sizeof(struct iphdr);
 144
 145         /* new package */
 146         printf("\n");
 147         printf("---> package %d ---- %s",my_info_struct->count,
 148                         ctime((const time_t*)&(pcap_header->ts.tv_sec)));
 149
 150         /* pcap header */
 151         printf("pcap header: ");
 152         printf("capture_length(dec): %d\t",pcap_header->caplen);
 153         printf("off_wire_length(dec): %d\n",pcap_header->len);
 154
 155         /* wireless stuff */
 156         /* prism wlan ng headers */
 157         if((my_info_struct->mmode-0x30==1) &&
 158                 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
 159         printf("prism header: (%d bytes)\n",p_o);
 160         prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
 161         printf("| message code/length: %d/%d |\t",prism_hdr->msgcode,
 162                                                 prism_hdr->msglen);
 163         printf("device: %s |\n",prism_hdr->devname);
 164         /* ieee802.11 header */
 165         printf("ieee802.11 header: (%d bytes)\n",w_o);
 166         w_hdr=(struct ieee802_11_hdr *)(package+p_o);
 167
 168         printf("fc: ");
 169         for(i=0;i<16;i++)
 170                 printf("%s%d%s",(i==0?"|":""),
 171                                 (((w_hdr->frame_ctl) & (1<<i))>0?1:0),
 172                                 (i==15?"|\n":"|"));
 173         printf("    | v | t |  s-t  |t|f|m|r|p|m|w|o|\n");
 174         /* frame type */
 175         /* management */
 176         if(!(w_hdr->frame_ctl & 0x0c)) {
 177         if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_REQ)>0)
 178                 strcpy(tmp_buf,"association request");
 179         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_RESP)>0)
 180                 strcpy(tmp_buf,"association response");
 181         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_REQ)>0)
 182                 strcpy(tmp_buf,"reassociation request");
 183         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_RESP)>0)
 184                 strcpy(tmp_buf,"reassociation response");
 185         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_REQ)>0)
 186                 strcpy(tmp_buf,"probe request");
 187         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_RESP)>0)
 188                 strcpy(tmp_buf,"probe response");
 189         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_BEACON)>0)
 190                 strcpy(tmp_buf,"beacon");
 191         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ATIM)>0)
 192                 strcpy(tmp_buf,"announcement traffic indication message");
 193         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DISASSOC)>0)
 194                 strcpy(tmp_buf,"disassociation");
 195         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_AUTH)>0)
 196                 strcpy(tmp_buf,"authentification");
 197         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DEAUTH)>0)
 198                 strcpy(tmp_buf,"deauthentification");
 199         else strcpy(tmp_buf,"impossible situation \%) - go mail the author.");
 200         }
 201         else strcpy(tmp_buf,"control & data frame type not supported yet");
 202         /* print out frame type */
 203         printf("=> %s\n",tmp_buf);
 204
 205         printf("duration/id: 0x%x\n",w_hdr->duration_id);
 206         printf("version check ... %s\n",
 207         ((w_hdr->frame_ctl & IEEE802_11_FCTL_VERS)==0x00)?
 208                                                         "ok":"unknown");
 209         }
 210
 211         /* ieee802.3 */
 212         /* we need smaller w_hdr for non distributed frames */
 213         if((w_hdr->frame_ctl & (1<<8)) & (w_hdr->frame_ctl & (1<<9))) {
 214                 printf("=> distributed packet !!!!11\n");
 215         } else w_o-=(sizeof(struct snaphdr)-sizeof(unsigned short));
 216
 217         /* ethernet */
 218         if((strncmp(my_info_struct->dev,"eth",3)==0) |
 219                 ((w_hdr->frame_ctl & IEEE802_11_FTYPE_DATA)>0)) {
 220
 221         if(!(w_hdr->frame_ctl & IEEE802_11_FTYPE_DATA)) {
 222                 printf("ethernet: (%d bytes)\n",e_o);
 223                 e_hdr=(struct ethhdr *)(package+p_o+w_o);
 224                 /* what types ? */
 225                 printf("type = ");
 226                 printf("%x  ",ntohs(e_hdr->h_proto));
 227                 printf("dest_addr = ");
 228                 for(i=0;i<ETH_ALEN;i++)
 229                 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
 230                 printf(" src_addr = ");
 231                 for(i=0;i<ETH_ALEN;i++) printf("%x%s",*(e_hdr->h_source+i),
 232                                                 ((i==ETH_ALEN-1)?"\n":":"));
 233         }
 234         else {
 235                 snap_hdr=(struct snaphdr *)(package+p_o+w_o);
 236                 if(snap_hdr->snap[0]==0xaa &
 237                    snap_hdr->snap[1]==0xaa &
 238                    snap_hdr->snap[2]==0x03 &
 239                    snap_hdr->snap[3]==0x00 &
 240                    snap_hdr->snap[4]==0x00 &
 241                    snap_hdr->snap[5]==0x00) {
 242                         printf("- no encryption!\n");
 243                         if(snap_hdr->proto==ntohs(ETH_P_IP)) {
 244                                 /* we want ip header to get parsed */
 245                                 e_hdr->h_proto=htons(ETH_P_IP);
 246                                 e_o=sizeof(struct snaphdr);
 247                         }
 248                 }
 249                 else {
 250                         printf("- crypted packet!\n");
 251                         /* print crypted snap - write into file */
 252                         printf("snap: (aa aa 03 00 00 00) ");
 253                         for(i=0;i<6;i++) {
 254                                 printf("%x ",snap_hdr->snap[i]);
 255                                 if(file_fd>0) write(file_fd,snap_hdr->snap+i,1);
 256                         }
 257                         printf("\n");
 258                         // write(file_fd,'\n',1);
 259                         /* dont look at ipheader */
 260                         e_hdr->h_proto=htons(0);
 261                 }
 262         }
 263
 264                 /* IP ? */
 265         if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
 266                 printf("ip protocol: (%d bytes)\n",i_o);
 267                 ip_hdr=(struct iphdr *)(package+p_o+w_o+e_o);
 268                 printf("version = %x ",ntohs(ip_hdr->version));
 269                 printf("header_length = %x \n",ntohs(ip_hdr->ihl));
 270                 printf("service = %x ",ntohs(ip_hdr->tos));
 271                 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->tot_len));
 272                 printf("source_ip: ");
 273                 for(i=0;i<=3;++i) {
 274                         printf("%d%s",
 275                         (ip_hdr->saddr&(0xff<<(8*i)))>>(8*i),
 276                         (i==3?"\n":"."));
 277                 }
 278                 printf("destination_ip: ");
 279                 for(i=0;i<=3;++i) {
 280                         printf("%d%s",
 281                         (ip_hdr->daddr&(0xff<<(8*i)))>>(8*i),
 282                         (i==3?"\n":"."));
 283                 }
 284                 printf("ip_id = %x ",ntohs(ip_hdr->id));
 285                 printf("ip_offset = %x \n",ntohs(ip_hdr->frag_off));
 286                 printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ttl),
 287                                                 ntohs(ip_hdr->protocol));
 288                 // printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
 289         }
 290         }
 291
 292         /* check what we have ... */
 293         printf("all dump: (hex)\n");
 294         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 295                 printf("%x ",*(package+i));
 296         printf("\n");
 297         printf("all dump: (char)\n");
 298         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 299                 printf("%c ",*(package+i));
 300         printf("\n");
 301 }
 302
 303 int hop_channel(struct info_struct *info,int foo_fd) {
 304         if((info->mmode-0x30==1) && (strncmp(info->dev,"wlan",4)==0)) {
 305
 306         struct iwreq my_iwreq;
 307
 308         if (info->channel>=14) info->channel=1;
 309
 310         memset(&my_iwreq,0,sizeof(my_iwreq));
 311         strcpy(my_iwreq.ifr_name,info->dev);
 312         printf("debug: channel = %d\n",info->channel);
 313         my_iwreq.u.freq.e=0;
 314         my_iwreq.u.freq.m=info->channel;
 315         if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
 316                 printf("unable to hop channels\n");
 317                 perror("ioctl");
 318                 return -1;
 319         }
 320         ++(info->channel);
 321         }
 322         return 0;
 323 }