/* * larp.c (C) 1995 Darren Reed * * The author provides this program as-is, with no gaurantee for its * suitability for any specific purpose. The author takes no responsibility * for the misuse/abuse of this program and provides it for the sole purpose * of testing packet filter policies. This file maybe distributed freely * providing it is not modified and that this notice remains in tact. */ #if !defined(lint) && defined(LIBC_SCCS) static char sccsid[] = "@(#)larp.c 1.1 8/19/95 (C)1995 Darren Reed"; #endif #include #include #include #include #include #include #include #include #include /* * lookup host and return * its IP address in address * (4 bytes) */ int resolve(host, address) char *host, *address; { struct hostent *hp; u_long add; add = inet_addr(host); if (add == -1) { if (!(hp = gethostbyname(host))) { fprintf(stderr, "unknown host: %s\n", host); return -1; } bcopy((char *)hp->h_addr, (char *)address, 4); return 0; } bcopy((char*)&add, address, 4); return 0; } /* * ARP for the MAC address corresponding * to the IP address. This taken from * some BSD program, I cant remember which. */ int arp(ip, ether) char *ip; char *ether; { static int s = -1; struct arpreq ar; struct sockaddr_in *sin; char *inet_ntoa(); bzero((char *)&ar, sizeof(ar)); sin = (struct sockaddr_in *)&ar.arp_pa; sin->sin_family = AF_INET; bcopy(ip, (char *)&sin->sin_addr.s_addr, 4); if (s == -1) if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { perror("arp: socket"); return -1; } if (ioctl(s, SIOCGARP, (caddr_t)&ar) == -1) { fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr)); if (errno != ENXIO) perror("SIOCGARP"); return -1; } bcopy(ar.arp_ha.sa_data, ether, 6); return 0; }