2 * hdw-sniff, sniffer using pcap lib
4 * author: hackbard@hackdaworld.dyndns.org
10 #include <sys/socket.h>
12 #include <netinet/in.h>
13 #include <arpa/inet.h>
15 #include <sys/types.h>
17 #include <sys/ioctl.h>
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 */
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 */
28 #include "hdw-sniff.h" /* my functions */
30 int main(int argc, char *argv[]) {
32 char pcap_error[PCAP_ERRBUF_SIZE];
36 struct timeval fd_set_tv;
39 struct info_struct my_info_struct;
41 /* parse the arguments */
43 printf("usage: %s <interface> <monitor mode> <logfile>\n",
48 printf("no logfile specified, writing to stdout ...\n");
51 if((logfile=fopen(argv[3],"w"))!=NULL) {
52 printf("writing to logfile %s ...\n",argv[3]);
55 printf("can't open logfile!\n");
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]);
68 printf("setting up interface\n");
69 sprintf(sys_call,"ifconfig %s up",argv[1]);
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);
79 /* set non blocking */
80 if((pcap_setnonblock(pcap_handle,1,pcap_error))==-1) {
81 printf("%s: %s\n",argv[0],pcap_error);
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]);
90 /* prepare for select */
91 pcap_fd=pcap_fileno(pcap_handle);
92 FD_ZERO(&pcap_fd_set);
93 FD_SET(pcap_fd,&pcap_fd_set);
95 fd_set_tv.tv_usec=500000;
99 if((select(pcap_fd+1,&pcap_fd_set,NULL,NULL,&fd_set_tv)) && (FD_ISSET(pcap_fd,&pcap_fd_set))) pcap_loop(pcap_handle,-1,pcap_process,(u_char *)&my_info_struct);
100 else hop_channel(&my_info_struct,pcap_fd);
106 /* pcap_process callback function */
107 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
108 const u_char *package) {
110 /* local variables */
111 struct linux_wlan_ng_prism_hdr *prism_hdr;
112 struct ieee802_11_hdr *w_hdr;
114 struct ethhdr *e_hdr;
115 struct info_struct *my_info_struct;
118 my_info_struct=(struct info_struct *)info;
119 ++(my_info_struct->count);
122 printf("---> package %d ---- %s",my_info_struct->count,
123 ctime((const time_t*)&(pcap_header->ts.tv_sec)));
124 printf("pcap header:\n");
125 printf("capture_length: %d (dec.)\t",pcap_header->caplen);
126 printf("length(off wire): %d (dec.)\n",pcap_header->len);
128 /* prism wlan ng headers */
129 if((my_info_struct->mmode-0x30==1) &&
130 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
131 printf("prism header:\n");
132 prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
133 printf("message code/length: %d/%d\n",ntohs(prism_hdr->msgcode),
134 ntohs(prism_hdr->msglen));
135 printf("device: %s\n",prism_hdr->devname);
137 /* ieee802.11 header */
138 printf("ieee802.11 header:\n");
139 package+=sizeof(struct linux_wlan_ng_prism_hdr);
140 w_hdr=(struct ieee802_11_hdr *)package;
144 printf("%x -> ",1<<i);
145 printf("%x\n",(ntohs(w_hdr->frame_ctl) & (1<<i)));
147 printf("frame_control: %x duration_id: %x\n",ntohs(w_hdr->frame_ctl),
148 ntohs(w_hdr->duration_id));
149 printf("version check ... %s\n",
150 ((ntohs(w_hdr->frame_ctl) & IEEE802_11_FCTL_VERS)==0x00)?
153 /* skip ieee802.11 header */
154 package=package+sizeof(struct ieee802_11_hdr);
159 e_hdr=(struct ethhdr *)package;
162 printf("%x ",ntohs(e_hdr->h_proto));
163 printf("dest_addr = ");
164 for(i=0;i<ETH_ALEN;i++)
165 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
166 printf(" src_addr = ");
167 for(i=0;i<ETH_ALEN;i++)
168 printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
170 if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
171 printf("ip protocol: ");
172 ip_hdr=(struct ip *)(package+sizeof(struct ethhdr));
173 printf("version = %x ",ntohs(ip_hdr->ip_v));
174 printf("header_length = %x \n",ntohs(ip_hdr->ip_hl));
175 printf("service = %x ",ntohs(ip_hdr->ip_tos));
176 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->ip_len));
177 printf("ip_addresses: source = ");
178 printf("%s\tdestination = %s\n",inet_ntoa(ip_hdr->ip_src),
179 inet_ntoa(ip_hdr->ip_dst));
180 printf("ip_id = %x ",ntohs(ip_hdr->ip_id));
181 printf("ip_offset = %x \n",ntohs(ip_hdr->ip_off));
182 printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ip_ttl),
183 ntohs(ip_hdr->ip_p));
184 printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
186 printf("all_hex_dump:\n");
187 for(i=sizeof(struct ethhdr);i<pcap_header->caplen;i++)
188 printf("%x ",*(package+i));
192 int hop_channel(struct info_struct *info,int pcap_fd) {
193 struct iwreq my_iwreq;
195 if (info->channel==15) info->channel=1;
197 memset(&my_iwreq,0,sizeof(my_iwreq));
198 strcpy(my_iwreq.ifr_name,info->dev);
200 my_iwreq.u.freq.m=info->channel;
201 if((ioctl(pcap_fd,SIOCSIWFREQ,& my_iwreq))==-1) {
202 printf("unable to hop channels\n");
205 printf("debug: hopped to channel %d\n",info->channel);