/* $NetBSD: arp.c,v 1.1.1.1 1999/12/11 22:24:07 veego Exp $ */ /* * arp.c (C) 1995-1998 Darren Reed * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and due credit is given * to the original author and the contributors. */ #if !defined(lint) static const char sccsid[] = "@(#)arp.c 1.4 1/11/96 (C)1995 Darren Reed"; static const char rcsid[] = "@(#)Id: arp.c,v 2.1 1999/08/04 17:31:03 darrenr Exp"; #endif #include #include #include #include #if !defined(ultrix) && !defined(hpux) #include #endif #include #include #include #include #include #ifndef ultrix #include #endif #include #include #include #include "ipsend.h" #include "iplang/iplang.h" /* * 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 sfd = -1; static char ethersave[6], ipsave[4]; struct arpreq ar; struct sockaddr_in *sin, san; struct hostent *hp; int fd; #ifdef IPSEND if (arp_getipv4(ip, ether) == 0) return 0; #endif if (!bcmp(ipsave, ip, 4)) { bcopy(ethersave, ether, 6); return 0; } fd = -1; 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); #ifndef hpux if ((hp = gethostbyaddr(ip, 4, AF_INET))) if (!(ether_hostton(hp->h_name, ether))) goto savearp; #endif if (sfd == -1) if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { perror("arp: socket"); return -1; } tryagain: if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1) { if (fd == -1) { bzero((char *)&san, sizeof(san)); san.sin_family = AF_INET; san.sin_port = htons(1); bcopy(ip, &san.sin_addr.s_addr, 4); fd = socket(AF_INET, SOCK_DGRAM, 0); (void) sendto(fd, ip, 4, 0, (struct sockaddr *)&san, sizeof(san)); sleep(1); (void) close(fd); goto tryagain; } fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr)); if (errno != ENXIO) perror("SIOCGARP"); return -1; } bcopy(ar.arp_ha.sa_data, ether, 6); savearp: bcopy(ether, ethersave, 6); bcopy(ip, ipsave, 4); return 0; }