2 * hdw-sniff, sniffer using pcap lib
4 * author: hackbard@hackdaworld.dyndns.org
12 #include <sys/socket.h>
14 #include <netinet/in.h>
15 #include <arpa/inet.h>
17 #include <sys/types.h>
21 #include <sys/ioctl.h>
23 /* IEEE 802.3 stuff -- i will concentrate on .11 stuff before! */
24 #include <netinet/if_ether.h> /* for ethhdr struct */
25 #include <netinet/ip.h> /* ip */
26 #include <netinet/in.h> /* in_addr , inet_ntoa */
27 #include <netinet/tcp.h> /* tcp header and protocols */
29 /* IEEE 802.11 stuff -- will become one include later ... */
30 #include "ieee80211.h" /* from hunz's aeolus, short hostap_wlan.h */
31 #include "ieee802_11.h" /* from pcmcia-cs */
33 #include "hdw-sniff.h" /* my functions */
35 /* global variables */
38 int main(int argc, char *argv[]) {
40 char pcap_error[PCAP_ERRBUF_SIZE];
44 struct timeval fd_set_tv;
46 struct info_struct my_info_struct;
48 /* parse the arguments */
50 printf("usage: %s <interface> <monitor mode> <logfile>\n",
55 printf("no logfile specified, writing to stdout ...\n");
58 if((file_fd=open(argv[3],O_RDWR | O_CREAT))!=0) {
59 printf("writing to logfile %s ...\n",argv[3]);
60 dprintf(file_fd,"|iv - --|id|crypted_snap - --|\n");
63 printf("can't open logfile. not logged to file!\n");
67 /* setting up device and set monitor mode */
68 if(atoi(argv[2])==1) {
69 printf("setting to monitor mode\n");
70 if(strncmp(argv[1],"wlan",4)==0)
71 sprintf(sys_call,"iwconfig %s mode monitor",argv[1]);
72 if(strncmp(argv[1],"eth",3)==0)
73 sprintf(sys_call,"ifconfig %s promisc",argv[1]);
76 printf("setting up interface\n");
77 sprintf(sys_call,"ifconfig %s up",argv[1]);
80 /* start pcap session */
81 pcap_handle=pcap_open_live(argv[1],BUFSIZ,1,-1,pcap_error);
82 if(pcap_handle==NULL) {
83 printf("%s: %s\n",argv[0],pcap_error);
87 /* set non blocking */
88 if((pcap_setnonblock(pcap_handle,1,pcap_error))==-1) {
89 printf("%s: %s\n",argv[0],pcap_error);
94 my_info_struct.count=0;
95 my_info_struct.mmode=argv[2][0];
96 my_info_struct.ssid_list=(struct list *)malloc(sizeof(struct list));
97 my_info_struct.ssid_list->next=NULL;
98 // strcpy(my_info_struct.ssid_list->ssid,"test");
99 strcpy(my_info_struct.dev,argv[1]);
100 my_info_struct.channel=1;
102 /* prepare for select */
103 pcap_fd=pcap_fileno(pcap_handle);
105 /* create file descriptor */
106 if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
107 printf("unable to create socket foo_fd\n");
115 FD_ZERO(&pcap_fd_set);
116 FD_SET(pcap_fd,&pcap_fd_set);
118 fd_set_tv.tv_usec=200000;
120 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);
121 else if((hop_channel(&my_info_struct,foo_fd))==-1) {
122 printf("channelhopping failed, aborting\n");
130 /* pcap_process callback function */
131 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
132 const u_char *package) {
134 /* local variables */
135 char tmp_buf[20],tmp_buf1[10],tmp_buf2[32];
136 unsigned char crypted_snap[12];
137 struct linux_wlan_ng_prism_hdr *prism_hdr;
138 struct ieee802_11_hdr *w_hdr;
139 struct snaphdr *snap_hdr;
140 struct beacon_struct *beacon_hdr;
141 struct ethhdr *e_hdr;
142 struct info_struct *my_info_struct;
143 int i,p_o,w_o,e_o,i_o,special_o=0;
145 my_info_struct=(struct info_struct *)info;
146 ++(my_info_struct->count);
149 p_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct linux_wlan_ng_prism_hdr):0);
150 w_o=((strncmp(my_info_struct->dev,"wlan",4)==0)?sizeof(struct ieee802_11_hdr):0);
151 e_o=sizeof(struct ethhdr);
152 i_o=sizeof(struct iphdr);
156 printf("---> package %d ---- %s",my_info_struct->count,
157 ctime((const time_t*)&(pcap_header->ts.tv_sec)));
160 printf("pcap header: ");
161 printf("capture_length(dec): %d\t",pcap_header->caplen);
162 printf("off_wire_length(dec): %d\n",pcap_header->len);
165 /* prism wlan ng headers */
166 if((my_info_struct->mmode-0x30==1) &
167 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
168 printf("prism header: (%d bytes)\n",p_o);
169 prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
170 printf("| message code/length: %d/%d |\t",prism_hdr->msgcode,
172 printf("device: %s |\n",prism_hdr->devname);
173 /* ieee802.11 header */
175 /* we need smaller w_hdr for non distributed frames */
176 if((w_hdr->frame_ctl & (1<<8)) && (w_hdr->frame_ctl & (1<<9))) {
177 printf("=> distributed packet !!!!11\n");
178 } else w_o-=(sizeof(struct snaphdr)-sizeof(unsigned short));
180 printf("ieee802.11 header: (%d bytes)\n",w_o);
181 w_hdr=(struct ieee802_11_hdr *)(package+p_o);
185 printf("%s%d%s",(i==0?"|":""),
186 (((w_hdr->frame_ctl) & (1<<i))>0?1:0),
188 printf(" | v | t | s-t |t|f|m|r|p|m|w|o|\n");
191 if(!(w_hdr->frame_ctl & 0x0c)) {
192 tmp_buf1[0]='\0'; tmp_buf2[0]='\0';
193 if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_REQ)>0)
194 strcpy(tmp_buf,"association request");
195 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ASSOC_RESP)>0)
196 strcpy(tmp_buf,"association response");
197 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_REQ)>0)
198 strcpy(tmp_buf,"reassociation request");
199 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_REASSOC_RESP)>0)
200 strcpy(tmp_buf,"reassociation response");
201 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_REQ)>0)
202 strcpy(tmp_buf,"probe request");
203 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_PROBE_RESP)>0)
204 strcpy(tmp_buf,"probe response");
205 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_BEACON)==IEEE802_11_STYPE_BEACON) {
206 beacon_hdr=(struct beacon_struct *)(package+p_o+w_o);
207 beacon_hdr->ssid_s.elementid==0?strcpy(tmp_buf1,"essid = ")
208 :strcpy(tmp_buf1,"ibssid = ");
209 strncpy(tmp_buf2,beacon_hdr->ssid_s.ssid,
210 beacon_hdr->ssid_s.length);
212 tmp_buf2[beacon_hdr->ssid_s.length]='\0';
213 strcpy(tmp_buf,"beacon");
214 add_ssid_2_list(tmp_buf2,beacon_hdr->capability,
215 my_info_struct->ssid_list);
217 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_ATIM)>0)
218 strcpy(tmp_buf,"announcement traffic indication message");
219 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DISASSOC)>0)
220 strcpy(tmp_buf,"disassociation");
221 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_AUTH)>0)
222 strcpy(tmp_buf,"authentification");
223 else if((w_hdr->frame_ctl & IEEE802_11_STYPE_DEAUTH)>0)
224 strcpy(tmp_buf,"deauthentification");
225 else strcpy(tmp_buf,"impossible situation \%) - go mail the author.");
227 else strcpy(tmp_buf,"control or data frame type");
229 printf("=> %s\n",tmp_buf);
230 if((strlen(tmp_buf1)>0) && (strlen(tmp_buf2)>0)) printf(" %s%s\n",
233 printf("duration/id: 0x%x\n",w_hdr->duration_id);
234 printf("version check ... %s\n",
235 ((w_hdr->frame_ctl & IEEE802_11_FCTL_VERS)==0x00)?
240 if((strncmp(my_info_struct->dev,"eth",3)==0) |
241 ((w_hdr->frame_ctl & IEEE802_11_FTYPE_DATA)==IEEE802_11_FTYPE_DATA)) {
243 if((strncmp(my_info_struct->dev,"eth",3)==0)) {
244 printf("ethernet: (%d bytes)\n",e_o);
245 e_hdr=(struct ethhdr *)(package+p_o+w_o);
246 special_o=sizeof(struct ethhdr);
249 printf("%x ",ntohs(e_hdr->h_proto));
250 printf("dest_addr = ");
251 for(i=0;i<ETH_ALEN;i++)
252 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
253 printf(" src_addr = ");
254 for(i=0;i<ETH_ALEN;i++) printf("%x%s",*(e_hdr->h_source+i),
255 ((i==ETH_ALEN-1)?"\n":":"));
256 if((ntohs(e_hdr->h_proto)==ETH_P_IP))
257 parse_ip(package+p_o+w_o+e_o);
260 snap_hdr=(struct snaphdr *)(package+p_o+w_o);
261 if((snap_hdr->snap[0]==0xaa) &
262 (snap_hdr->snap[1]==0xaa) &
263 (snap_hdr->snap[2]==0x03) &
264 (snap_hdr->snap[3]==0x00) &
265 (snap_hdr->snap[4]==0x00) &
266 (snap_hdr->snap[5]==0x00)) {
267 printf("- no encryption!\n");
268 if(snap_hdr->proto==ntohs(ETH_P_IP)) {
269 e_o=sizeof(struct snaphdr);
270 parse_ip((char *)(snap_hdr+e_o));
275 printf("- crypted packet!\n");
276 /* print crypted snap - write into file */
277 printf("snap: (iv(3) + index(1) + crypted snap(6)) ");
279 printf("%x ",*(snap_hdr->snap+i));
280 crypted_snap[i]=*(snap_hdr->snap+i);
283 crypted_snap[4]^=0xaa;
284 crypted_snap[5]^=0xaa;
285 crypted_snap[6]^=0x03;
286 crypted_snap[7]^=0x00;
287 crypted_snap[8]^=0x00;
288 crypted_snap[9]^=0x00;
292 crypted_snap[10]='\0';
293 crypted_snap[11]='\n';
296 printf("debug: saved to file\n");
297 dprintf(file_fd,IVLINE,IVL_ARGS);
305 printf("all dump: (hex)\n");
306 for(i=p_o+w_o+special_o;i<pcap_header->caplen;i++)
307 printf("%x ",*(package+i));
311 printf("all dump: (char)\n");
312 for(i=p_o+w_o;i<pcap_header->caplen;i++)
313 printf("%c ",*(package+i));
318 int hop_channel(struct info_struct *info,int foo_fd) {
319 if((info->mmode-0x30==1) && (strncmp(info->dev,"wlan",4)==0)) {
321 struct iwreq my_iwreq;
323 if (info->channel>=C_MAX) info->channel=1;
325 memset(&my_iwreq,0,sizeof(my_iwreq));
326 strcpy(my_iwreq.ifr_name,info->dev);
328 my_iwreq.u.freq.m=info->channel;
329 if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
330 printf("unable to hop channels\n");
339 int parse_ip(char *ip_o) {
340 struct iphdr *ip_hdr;
343 printf("ip protocol:\n");
344 ip_hdr=(struct iphdr *)ip_o;
345 printf("version = %x ",ip_hdr->version);
346 printf("header_length = %x \n",ip_hdr->ihl);
347 printf("service = %x ",ip_hdr->tos);
348 printf("total_length(dec.) = %d \n",ip_hdr->tot_len);
349 printf("source_ip: ");
352 (ip_hdr->saddr&(0xff<<(8*i)))>>(8*i),
355 printf("destination_ip: ");
358 (ip_hdr->daddr&(0xff<<(8*i)))>>(8*i),
361 printf("ip_id = %x ",ntohs(ip_hdr->id));
362 printf("ip_offset = %x \n",ip_hdr->frag_off);
363 printf("time2live = %x ip_proto = %x\n",ip_hdr->ttl,ip_hdr->protocol);
364 /* how to continue */
365 if(ip_hdr->protocol==IPPROTO_TCP)
366 parse_tcp(ip_hdr+sizeof(struct iphdr));
367 if(ip_hdr->protocol==IPPROTO_UDP)
368 printf("udp package! get's parsed in the future\n");
369 // printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
372 int parse_tcp(char *tcp_o) {
373 struct tcphdr *tcp_hdr;
375 printf("tcp protocol:\n");
376 tcp_hdr=(struct tcphdr *)tcp_o;
377 printf("source port: %d - dest port: %d\n",ntohs(tcp_hdr->source),
378 ntohs(tcp_hdr->dest));
379 printf("sequence: %d - ack sequence: %d\n",ntohs(tcp_hdr->seq),
380 ntohs(tcp_hdr->ack_seq));
381 printf("offset to data: %d - checksumm: %d\n",ntohs(tcp_hdr->doff)
382 ,ntohs(tcp_hdr->check));