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);
93 /* create file descriptor */
94 if((foo_fd=socket(AF_INET,SOCK_DGRAM,0))==-1) {
95 printf("unable to create socket foo_fd\n");
103 FD_ZERO(&pcap_fd_set);
104 FD_SET(pcap_fd,&pcap_fd_set);
106 fd_set_tv.tv_usec=500000;
108 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);
109 else if((hop_channel(&my_info_struct,foo_fd))==-1) {
110 printf("channelhopping failed, aborting\n");
118 /* pcap_process callback function */
119 void pcap_process(u_char *info,const struct pcap_pkthdr *pcap_header,
120 const u_char *package) {
122 /* local variables */
123 struct linux_wlan_ng_prism_hdr *prism_hdr;
124 struct ieee802_11_hdr *w_hdr;
125 struct ethhdr *e_hdr;
127 struct info_struct *my_info_struct;
130 my_info_struct=(struct info_struct *)info;
131 ++(my_info_struct->count);
134 printf("---> package %d ---- %s",my_info_struct->count,
135 ctime((const time_t*)&(pcap_header->ts.tv_sec)));
136 printf("pcap header:\n");
137 printf("capture_length: %d (dec.)\t",pcap_header->caplen);
138 printf("length(off wire): %d (dec.)\n",pcap_header->len);
140 /* prism wlan ng headers */
141 if((my_info_struct->mmode-0x30==1) &&
142 (strncmp(my_info_struct->dev,"wlan",4)==0)) {
143 printf("prism header:\n");
144 prism_hdr=(struct linux_wlan_ng_prism_hdr *)package;
145 printf("message code/length: %d/%d\n",ntohs(prism_hdr->msgcode),
146 ntohs(prism_hdr->msglen));
147 printf("device: %s\n",prism_hdr->devname);
149 /* ieee802.11 header */
150 printf("ieee802.11 header:\n");
151 package+=sizeof(struct linux_wlan_ng_prism_hdr);
152 w_hdr=(struct ieee802_11_hdr *)package;
156 printf("%x -> ",1<<i);
157 printf("%x\n",(ntohs(w_hdr->frame_ctl) & (1<<i)));
159 printf("frame_control: %x duration_id: %x\n",ntohs(w_hdr->frame_ctl),
160 ntohs(w_hdr->duration_id));
161 printf("version check ... %s\n",
162 ((ntohs(w_hdr->frame_ctl) & IEEE802_11_FCTL_VERS)==0x00)?
165 /* skip ieee802.11 header */
166 package=package+sizeof(struct ieee802_11_hdr);
171 printf("ethernet:\n");
172 e_hdr=(struct ethhdr *)package;
175 printf("%x ",ntohs(e_hdr->h_proto));
176 printf("dest_addr = ");
177 for(i=0;i<ETH_ALEN;i++)
178 printf("%x%s",*(e_hdr->h_dest+i),((i==ETH_ALEN-1)?" ":":"));
179 printf(" src_addr = ");
180 for(i=0;i<ETH_ALEN;i++)
181 printf("%x%s",*(e_hdr->h_source+i),((i==ETH_ALEN-1)?"\n":":"));
183 if(ntohs(e_hdr->h_proto)==ETH_P_IP) {
184 printf("ip protocol: ");
185 ip_hdr=(struct ip *)(package+sizeof(struct ethhdr));
186 printf("version = %x ",ntohs(ip_hdr->ip_v));
187 printf("header_length = %x \n",ntohs(ip_hdr->ip_hl));
188 printf("service = %x ",ntohs(ip_hdr->ip_tos));
189 printf("total_length(dec.) = %d \n",ntohs(ip_hdr->ip_len));
190 printf("ip_addresses: source = ");
191 printf("%s\tdestination = %s\n",inet_ntoa(ip_hdr->ip_src),
192 inet_ntoa(ip_hdr->ip_dst));
193 printf("ip_id = %x ",ntohs(ip_hdr->ip_id));
194 printf("ip_offset = %x \n",ntohs(ip_hdr->ip_off));
195 printf("time2live = %x ip_proto = %x\n",ntohs(ip_hdr->ip_ttl),
196 ntohs(ip_hdr->ip_p));
197 printf("chksum: %x\n",ntohs(ip_hdr->ip_sum));
199 printf("all_hex_dump:\n");
200 for(i=sizeof(struct ethhdr);i<pcap_header->caplen;i++)
201 printf("%x ",*(package+i));
205 int hop_channel(struct info_struct *info,int foo_fd) {
206 struct iwreq my_iwreq;
208 if (info->channel>=14) info->channel=1;
210 memset(&my_iwreq,0,sizeof(my_iwreq));
211 strcpy(my_iwreq.ifr_name,info->dev);
212 printf("debug: device = %s\n",my_iwreq.ifr_name);
213 printf("debug: %d\n",foo_fd);
214 printf("debug: channel = %d\n",info->channel);
216 my_iwreq.u.freq.m=info->channel;
217 if((ioctl(foo_fd,SIOCSIWFREQ,&my_iwreq))==-1) {
218 printf("unable to hop channels\n");
222 printf("debug: hopped to channel %d\n",info->channel);