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