TUCoPS :: Unix :: General :: neped.c

/* -----------------------------------------
 Network Promiscuous Ethernet Detector.
 Linux 2.0.x / 2.1.x, libc5 & GlibC
 -----------------------------------------
 (c) 1998 savage@apostols.org
 -----------------------------------------
 Toxyn Technologies Inc.
 Scan your subnet, and detect promiscuous
 machinez. It really works, not a joke.
 ----------------------------------------- */
/*
 * $Id: neped.c,v 1.2 1998年06月04日 17:58:17 savage Exp $
 */
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <malloc.h>
#include <ctype.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/tcp.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <time.h>
#define ETH_P_ARP 0x0806
#define MAX_PACK_LEN 2000
#define ETHER_HEADER_LEN 14
#define ARPREQUEST 1
#define ARPREPLY 2
#define perr(s) fprintf(stderr,s)
struct arp_struct
 {
 u_char dst_mac[6];
 u_char src_mac[6];
 u_short pkt_type;
 u_short hw_type;
 u_short pro_type;
 u_char hw_len;
 u_char pro_len;
 u_short arp_op;
 u_char sender_eth[6];
 u_char sender_ip[4];
 u_char target_eth[6];
 u_char target_ip[4];
 };
union
 {
 u_char full_packet[MAX_PACK_LEN];
 struct arp_struct arp_pkt;
 }
a;
#define full_packet a.full_packet
#define arp_pkt a.arp_pkt
char *
inetaddr ( u_int32_t ip )
{
 struct in_addr in;
 in.s_addr = ip;
 return inet_ntoa(in);
}
char *
hwaddr (u_char * s)
{
 static char buf[30];
 sprintf (buf, "%02X:%02X:%02X:%02X:%02X:%02X", s[0], s[1], s[2], s[3],
s[4], s[5]);
 return buf;
}
void
main (int argc, char **argv)
{
 int rec;
 int len, from_len, rsflags;
 struct ifreq if_data;
 struct sockaddr from;
 u_int8_t myMAC[6];
 u_int32_t myIP, myNETMASK, myBROADCAST, ip, dip;
 if (getuid () != 0)
 {
 perr ("You must be root to run this program!\n");
 exit (0);
 }
 if (argc != 2)
 {
 fprintf(stderr,"Usage: %s eth0\n", argv[0]);
 exit (0);
 }
 if ((rec = socket (AF_INET, SOCK_PACKET, htons (ETH_P_ARP))) < 0)
 {
 perror("socket");
 exit (0);
 }
 printf ("----------------------------------------------------------\n");
 strcpy (if_data.ifr_name, argv[1]);
 if (ioctl (rec, SIOCGIFHWADDR, &if_data) < 0) {
 perr ("can't get HW addres of my interface!\n");
 exit(1);
 }
 memcpy (myMAC, if_data.ifr_hwaddr.sa_data, 6);
 printf ("> My HW Addr: %s\n", hwaddr (myMAC));
 if (ioctl (rec, SIOCGIFADDR, &if_data) < 0) {
 perr ("can't get IP addres of my interface!\n");
 exit(1);
 }
 memcpy ((void *) &ip, (void *) &if_data.ifr_addr.sa_data + 2, 4);
 myIP = ntohl (ip);
 printf ("> My IP Addr: %s\n", inetaddr(ip));
 if (ioctl (rec, SIOCGIFNETMASK, &if_data) < 0)
 perr ("can't get NETMASK addres of my interface!\n");
 memcpy ((void *) &ip, (void *) &if_data.ifr_netmask.sa_data + 2, 4);
 myNETMASK = ntohl (ip);
 printf ("> My NETMASK: %s\n", inetaddr(ip));
 if (ioctl (rec, SIOCGIFBRDADDR, &if_data) < 0)
 perr ("can't get BROADCAST addres of my interface!\n");
 memcpy ((void *) &ip, (void *) &if_data.ifr_broadaddr.sa_data + 2, 4);
 myBROADCAST = ntohl (ip);
 printf ("> My BROADCAST: %s\n", inetaddr(ip));
 if ((rsflags = fcntl (rec, F_GETFL)) == -1)
 {
 perror ("fcntl F_GETFL");
 exit (1);
 }
 if (fcntl (rec, F_SETFL, rsflags | O_NONBLOCK) == -1)
 {
 perror ("fcntl F_SETFL");
 exit (1);
 }
 printf ("----------------------------------------------------------\n");
 printf ("> Scanning ....\n");
 for (dip = (myIP & myNETMASK) + 1; dip < myBROADCAST; dip++)
 {
 bzero(full_packet, MAX_PACK_LEN);
 memcpy (arp_pkt.dst_mac, "0円6円146円3円23円67円", 6); /*
00:06:66:03:13:37 :) */
 memcpy (arp_pkt.src_mac, myMAC, 6);
 arp_pkt.pkt_type = htons( ETH_P_ARP );
 arp_pkt.hw_type = htons( 0x0001 );
 arp_pkt.hw_len = 6;
 arp_pkt.pro_type = htons( 0x0800 );
 arp_pkt.pro_len = 4;
 arp_pkt.arp_op = htons (ARPREQUEST);
 memcpy (arp_pkt.sender_eth, myMAC, 6);
 ip = htonl (myIP);
 memcpy (arp_pkt.sender_ip, &ip, 4);
 memcpy (arp_pkt.target_eth, "0円0円0円0円0円0円", 6);
 ip = htonl (dip);
 memcpy (arp_pkt.target_ip, &ip, 4);
 strcpy(from.sa_data, argv[1]);
 from.sa_family = 1;
 if( sendto (rec, full_packet, sizeof (struct arp_struct), 0, &from,
sizeof(from)) < 0)
 perror ("sendto");
 usleep (333);
 len = recvfrom (rec, full_packet, MAX_PACK_LEN, 0, &from,
&from_len);
 if (len <= ETHER_HEADER_LEN)
 continue;
 memcpy (&ip, arp_pkt.target_ip, 4);
 if (ntohs (arp_pkt.arp_op) == ARPREPLY
 && ntohl (ip) == myIP)
 {
 memcpy (&ip, arp_pkt.sender_ip, 4);
 printf ("*> Host %s, %s **** Promiscuous mode detected !!!\n",
 inetaddr (ip),
 hwaddr (arp_pkt.sender_eth));
 }
 }
 printf ("> End.\n");
 exit (0);
}