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 | O_CREAT))!=0) {
  56                         printf("writing to logfile %s ...\n",argv[3]);
  57                         dprintf(file_fd,"|iv - --|id|crypted_snap - --|\n");
  58                 }
  59                 else {
  60                         printf("can't open logfile. not logged to file!\n");
  61                 }
  62         }
  63
  64         /* setting up device and set monitor mode */
  65         if(atoi(argv[2])==1) {
  66                 printf("setting to monitor mode\n");
  67                 if(strncmp(argv[1],"wlan",4)==0)
  68                         sprintf(sys_call,"iwpriv %s monitor 3",argv[1]);
  69                 if(strncmp(argv[1],"eth",3)==0)
  70                         sprintf(sys_call,"ifconfig %s promisc",argv[1]);
  71         system(sys_call);
  72         }
  73         printf("setting up interface\n");
  74         sprintf(sys_call,"ifconfig %s up",argv[1]);
  75         system(sys_call);
  76
  77         /* start pcap session */
  78         pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
  79         if(pcap_handle==NULL) {
  80                 printf("%s: %s\n",argv[0],pcap_error);
  81                 return 1;
  82         }
  83
  84         /* set non blocking */
  85         if((pcap_setnonblock(pcap_handle,1,pcap_error))==-1) {
  86                 printf("%s: %s\n",argv[0],pcap_error);
  87                 return 1;
  88         }
  89
  90         /* set info struct */
  91         my_info_struct.count=0;
  92         my_info_struct.mmode=argv[2][0];
  93         my_info_struct.ssid_list=(struct list *)malloc(sizeof(struct list));
  94         my_info_struct.ssid_list->next=NULL;
  95         // strcpy(my_info_struct.ssid_list->ssid,"test");
  96         strcpy(my_info_struct.dev,argv[1]);
  97
  98         /* prepare for select */
  99         pcap_fd=pcap_fileno(pcap_handle);
 100
 101         /* create file descriptor */
 102         if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
 103                 printf("unable to create socket foo_fd\n");
 104                 return -1;
 105         }
 106
 107         /* do loopp */
 108         while (1) {
 109
 110                 /* set pcap_fd */
 111                 FD_ZERO(&pcap_fd_set);
 112                 FD_SET(pcap_fd,&pcap_fd_set);
 113                 fd_set_tv.tv_sec=0;
 114                 fd_set_tv.tv_usec=200000;
 115
 116                 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);
 117                 else if((hop_channel(&my_info_struct,foo_fd))==-1) {
 118                         printf("channelhopping failed, aborting\n");
 119                         return -1;
 120                 }
 121         }
 122         return 0;
 123 }
 124
 125
 126 /* pcap_process callback function */
 127 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
 128                         const u_char *package) {
 129
 130         /* local variables */
 131         char tmp_buf[20],tmp_buf1[10],tmp_buf2[32];
 132         unsigned char crypted_snap[12];
 133         struct linux_wlan_ng_prism_hdr *prism_hdr;
 134         struct ieee802_11_hdr *w_hdr;
 135         struct snaphdr *snap_hdr;
 136         struct beacon_struct *beacon_hdr;
 137         struct ethhdr *e_hdr;
 138         struct info_struct *my_info_struct;
 139         int i,p_o,w_o,e_o,i_o;
 140
 141         my_info_struct=(struct info_struct *)info;
 142         ++(my_info_struct->count);
 143
 144         /* cache offsets */
 145         p_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct linux_wlan_ng_prism_hdr):0);
 146         w_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct ieee802_11_hdr):0);
 147         e_o=sizeof(struct ethhdr);
 148         i_o=sizeof(struct iphdr);
 149
 150         /* new package */
 151         printf("\n");
 152         printf("---> package %d ---- %s",my_info_struct->count,
 153                         ctime((const time_t*)&(pcap_header->ts.tv_sec)));
 154
 155         /* pcap header */
 156         printf("pcap header: ");
 157         printf("capture_length(dec): %d\t",pcap_header->caplen);
 158         printf("off_wire_length(dec): %d\n",pcap_header->len);
 159
 160         /* wireless stuff */
 161         /* prism wlan ng headers */
 162         if((my_info_struct->mmode-0x30==1) &
 163                 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
 164         printf("prism header: (%d bytes)\n",p_o);
 165         prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
 166         printf("| message code/length: %d/%d |\t",prism_hdr->msgcode,
 167                                                 prism_hdr->msglen);
 168         printf("device: %s |\n",prism_hdr->devname);
 169         /* ieee802.11 header */
 170
 171         /* we need smaller w_hdr for non distributed frames */
 172         if((w_hdr->frame_ctl & (1<<8)) & (w_hdr->frame_ctl & (1<<9))) {
 173                 printf("=> distributed packet !!!!11\n");
 174         } else w_o-=(sizeof(struct snaphdr)-sizeof(unsigned short));
 175
 176         printf("ieee802.11 header: (%d bytes)\n",w_o);
 177         w_hdr=(struct ieee802_11_hdr *)(package+p_o);
 178
 179         printf("fc: ");
 180         for(i=0;i<16;i++)
 181                 printf("%s%d%s",(i==0?"|":""),
 182                                 (((w_hdr->frame_ctl) & (1<<i))>0?1:0),
 183                                 (i==15?"|\n":"|"));
 184         printf("    | v | t |  s-t  |t|f|m|r|p|m|w|o|\n");
 185         /* frame type */
 186         /* management */
 187         if(!(w_hdr->frame_ctl & 0x0c)) {
 188         tmp_buf1[0]='\0'; tmp_buf2[0]='\0';
 189         if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_REQ)>0)
 190                 strcpy(tmp_buf,"association request");
 191         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_RESP)>0)
 192                 strcpy(tmp_buf,"association response");
 193         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_REQ)>0)
 194                 strcpy(tmp_buf,"reassociation request");
 195         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_RESP)>0)
 196                 strcpy(tmp_buf,"reassociation response");
 197         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_REQ)>0)
 198                 strcpy(tmp_buf,"probe request");
 199         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_RESP)>0)
 200                 strcpy(tmp_buf,"probe response");
 201         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_BEACON)==IEEE802_11_STYPE_BEACON) {
 202                 beacon_hdr=(struct beacon_struct *)(package+p_o+w_o);
 203                 beacon_hdr->ssid_s.elementid==0?strcpy(tmp_buf1,"essid = ")
 204                                                 :strcpy(tmp_buf1,"ibssid = ");
 205                 strncpy(tmp_buf2,beacon_hdr->ssid_s.ssid,
 206                                 beacon_hdr->ssid_s.length);
 207                 tmp_buf2[beacon_hdr->ssid_s.length]='\0';
 208                 strcpy(tmp_buf,"beacon");
 209                 add_ssid_2_list(tmp_buf2,my_info_struct->ssid_list);
 210         }
 211         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ATIM)>0)
 212                 strcpy(tmp_buf,"announcement traffic indication message");
 213         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DISASSOC)>0)
 214                 strcpy(tmp_buf,"disassociation");
 215         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_AUTH)>0)
 216                 strcpy(tmp_buf,"authentification");
 217         else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DEAUTH)>0)
 218                 strcpy(tmp_buf,"deauthentification");
 219         else strcpy(tmp_buf,"impossible situation \%) - go mail the author.");
 220         }
 221         else strcpy(tmp_buf,"control or data frame type");
 222
 223         printf("=> %s\n",tmp_buf);
 224         if(strlen(tmp_buf1)>0 & strlen(tmp_buf2)>0) printf("   %s%s\n",
 225                                                         tmp_buf1,
 226                                                         tmp_buf2);
 227         printf("duration/id: 0x%x\n",w_hdr->duration_id);
 228         printf("version check ... %s\n",
 229         ((w_hdr->frame_ctl & IEEE802_11_FCTL_VERS)==0x00)?
 230                                                         "ok":"unknown");
 231         }
 232
 233         /* ethernet */
 234         if((strncmp(my_info_struct->dev,"eth",3)==0) |
 235         ((w_hdr->frame_ctl & IEEE802_11_FTYPE_DATA)==IEEE802_11_FTYPE_DATA)) {
 236
 237         if((strncmp(my_info_struct->dev,"eth",3)==0)) {
 238                 printf("ethernet: (%d bytes)\n",e_o);
 239                 e_hdr=(struct ethhdr *)(package+p_o+w_o);
 240                 /* what types ? */
 241                 printf("type = ");
 242                 printf("%x  ",ntohs(e_hdr->h_proto));
 243                 printf("dest_addr = ");
 244                 for(i=0;i<ETH_ALEN;i++)
 245                 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
 246                 printf(" src_addr = ");
 247                 for(i=0;i<ETH_ALEN;i++) printf("%x%s",*(e_hdr->h_source+i),
 248                                                 ((i==ETH_ALEN-1)?"\n":":"));
 249                 if((ntohs(e_hdr->h_proto)==ETH_P_IP))
 250                                         parse_ip(package+p_o+w_o+e_o);
 251         }
 252         else {
 253                 snap_hdr=(struct snaphdr *)(package+p_o+w_o);
 254                 if((snap_hdr->snap[0]==0xaa) &
 255                    (snap_hdr->snap[1]==0xaa) &
 256                    (snap_hdr->snap[2]==0x03) &
 257                    (snap_hdr->snap[3]==0x00) &
 258                    (snap_hdr->snap[4]==0x00) &
 259                    (snap_hdr->snap[5]==0x00)) {
 260                         printf("- no encryption!\n");
 261                         if(snap_hdr->proto==ntohs(ETH_P_IP)) {
 262                                 e_o=sizeof(struct snaphdr);
 263                                 parse_ip(snap_hdr+e_o);
 264                         }
 265
 266                 }
 267                 else {
 268                         printf("- crypted packet!\n");
 269                         /* print crypted snap - write into file */
 270                         printf("snap: (iv(3) + index(1) + crypted snap(6)) ");
 271                         for(i=0;i<10;i++) {
 272                                 printf("%x ",*(snap_hdr->snap+i));
 273                                 crypted_snap[i]=*(snap_hdr->snap+i);
 274                         }
 275                         /* xor with plain
 276                         crypted_snap[4]^=0xaa;
 277                         crypted_snap[5]^=0xaa;
 278                         crypted_snap[6]^=0x03;
 279                         crypted_snap[7]^=0x00;
 280                         crypted_snap[8]^=0x00;
 281                         crypted_snap[9]^=0x00;
 282                         */
 283
 284                         printf("\n");
 285                         crypted_snap[10]='\0';
 286                         crypted_snap[11]='\n';
 287
 288                         if(file_fd>0) {
 289                                 printf("debug: saved to file\n");
 290                                 dprintf(file_fd,IVLINE,IVL_ARGS);
 291                         }
 292                 }
 293         }
 294         }
 295
 296         /* dump it */
 297 #ifdef SHOW_HEX
 298         printf("all dump: (hex)\n");
 299         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 300                 printf("%x ",*(package+i));
 301         printf("\n");
 302 #endif
 303 #ifdef DEBUG_CHAR
 304         printf("all dump: (char)\n");
 305         for(i=p_o+w_o;i<pcap_header->caplen;i++)
 306                 printf("%c ",*(package+i));
 307         printf("\n");
 308 #endif
 309 }
 310
 311 int hop_channel(struct info_struct *info,int foo_fd) {
 312         if((info->mmode-0x30==1) && (strncmp(info->dev,"wlan",4)==0)) {
 313
 314         struct iwreq my_iwreq;
 315
 316         if (info->channel>=C_MAX) info->channel=1;
 317
 318         memset(&my_iwreq,0,sizeof(my_iwreq));
 319         strcpy(my_iwreq.ifr_name,info->dev);
 320         my_iwreq.u.freq.e=0;
 321         my_iwreq.u.freq.m=info->channel;
 322         if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
 323                 printf("unable to hop channels\n");
 324                 perror("ioctl");
 325                 return -1;
 326         }
 327         ++(info->channel);
 328         }
 329         return 0;
 330 }
 331
 332 int parse_ip(char *ip_o) {
 333         struct iphdr *ip_hdr;
 334         int i;
 335
 336         printf("ip protocol:\n");
 337         ip_hdr=(struct iphdr *)ip_o;
 338         printf("version = %x ",ntohs(ip_hdr->version));
 339         printf("header_length = %x \n",ntohs(ip_hdr->ihl));
 340         printf("service = %x ",ntohs(ip_hdr->tos));
 341         printf("total_length(dec.) = %d \n",ntohs(ip_hdr->tot_len));
 342         printf("source_ip: ");
 343                 for(i=0;i<=3;++i) {
 344                         printf("%d%s",
 345                         (ip_hdr->saddr&(0xff<<(8*i)))>>(8*i),
 346                         (i==3?"\n":"."));
 347                 }
 348         printf("destination_ip: ");
 349         for(i=0;i<=3;++i) {
 350                 printf("%d%s",
 351                 (ip_hdr->daddr&(0xff<<(8*i)))>>(8*i),
 352                 (i==3?"\n":"."));
 353         }
 354         printf("ip_id = %x ",ntohs(ip_hdr->id));
 355         printf("ip_offset = %x \n",ntohs(ip_hdr->frag_off));
 356         printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ttl),
 357                                                 ntohs(ip_hdr->protocol));
 358         // printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
 359 }