/* * *	NX-ROUTED *	RIP-2 Sniffing tool * *	Copyright (C) 2002 Andy Pershin * */ /* * $Id: rip2sniff.c,v 1.1.2.1 2007/03/20 09:53:10 anderson Exp $ */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netinet/ip.h>#include <netinet/udp.h>#include <time.h>#define RIP_MCAST   0xE0000009    /* 224.0.0.9 */#define RIP_PORT    520#define RIPv2       2#define USE_RAWstruct rte {    u_int16_t af;    u_int16_t tag;    struct in_addr prefix;    struct in_addr mask;    struct in_addr nexthop;    u_int32_t metric;};struct auth {    u_int16_t xffff;    u_int16_t type;    char password[16];};struct rip {    unsigned char command;    unsigned char version;    unsigned char pad1;    unsigned char pad2;};time_t lastt=0;time_t now=0;    static void show_packet(void *buf, int len) {    int rtes = (len - sizeof(struct rip)) / 20;     int i;    struct rip *pkt;    struct rte *r;    char *prefix, *mask, *nexthop;    pkt = (struct rip*)buf;    printf("Command: 0x%X\tVersion: 0x%X (delta t %d)\n", pkt->command, pkt->version, now-lastt);    for (i=0;i<rtes;i++) {        r = (struct rte *)(buf+sizeof(struct rip)+(sizeof(struct rte)*i));        prefix = strdup(inet_ntoa(r->prefix));        mask = strdup(inet_ntoa(r->mask));        nexthop = strdup(inet_ntoa(r->nexthop));        printf("  prefix: %s\tmask: %s\tnexthop: %s metric: %d\n",                prefix, mask, nexthop, ntohl(r->metric));        free(prefix);        free(mask);        free(nexthop);    }}int main (int argc, char *argv[]) {    int sock;    struct sockaddr_in addr, from;    struct ip_mreq m;    int i, len;    char buf[512];    char *buf2=buf;#ifdef USE_RAW    struct ip *ip=(struct ip *)buf;    struct udphdr *udp=(struct udphdr *)(buf+sizeof(struct ip));    /* usefull data after all headers */    buf2=buf+sizeof(struct ip)+sizeof(struct udphdr);#endif    memset(&addr, 0, sizeof(addr));    addr.sin_family = AF_INET;                                                        addr.sin_addr.s_addr = INADDR_ANY;    addr.sin_port = htons(RIP_PORT);#ifndef USE_RAW    if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {        perror("socket()");        return 1;    }    i = 1;    if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i)) < 0) {        perror("setsockopt(SO_REUSEADDR)");        return 1;    }    /* broadcast */    i = 1;    if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &i, sizeof(i)) < 0) {        perror("setsockopt(SO_BROADCAST)");        return 1;    }    /* multicast */    memset (&m, 0, sizeof(m));    m.imr_multiaddr.s_addr = htonl(RIP_MCAST);    m.imr_interface = (struct in_addr)addr.sin_addr;    if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0) {        perror("setsockopt(IP_ADD_MEMBERSHIP)");    }    if (bind(sock, (struct sockaddr *) &addr, sizeof (addr)) < 0) {        perror("bind()");        return 1;    }#else    if ((sock = socket(PF_INET, SOCK_RAW, IPPROTO_UDP)) < 0) {        perror("socket()");        return 1;    }#endif    now=time(NULL);    while (1) {        i = sizeof(from);        len = recvfrom(sock, buf, sizeof(buf), 0,                (struct sockaddr *) &from, &i);#ifdef USE_RAW	/* Process only the ones who got right dest port..	 * Dont mind checking ip->saddr...	 */  	if (ntohs(udp->dest) != RIP_PORT)	    continue;	len=len-sizeof(struct ip)-sizeof(struct udphdr);#endif	lastt=now;	time(&now);	if (now-lastt)	    printf("\n");        printf("Received %d bytes from %s\n", len, inet_ntoa(from.sin_addr));        if ((len - sizeof(struct rip)) % 20) {            fprintf(stderr, "Wrong packet size: %d\n", len);            continue;        }        show_packet(buf2, len);	    }    return 0;}