arp.c revision 255332 
11590Srgrimes/*	$FreeBSD: head/contrib/ipfilter/ipsend/arp.c 255332 2013-09-06 23:11:19Z cy $	*/
21590Srgrimes
31590Srgrimes/*
41590Srgrimes * arp.c (C) 1995-1998 Darren Reed
51590Srgrimes *
61590Srgrimes * See the IPFILTER.LICENCE file for details on licencing.
71590Srgrimes */
81590Srgrimes#if !defined(lint)
91590Srgrimesstatic const char sccsid[] = "@(#)arp.c	1.4 1/11/96 (C)1995 Darren Reed";
101590Srgrimesstatic const char rcsid[] = "@(#)$Id$";
111590Srgrimes#endif
121590Srgrimes#include <sys/types.h>
131590Srgrimes#include <sys/socket.h>
141590Srgrimes#if !defined(ultrix) && !defined(hpux) && !defined(__hpux) && !defined(__osf__) && !defined(_AIX51)
151590Srgrimes# include <sys/sockio.h>
161590Srgrimes#endif
171590Srgrimes#include <sys/ioctl.h>
181590Srgrimes#include <netinet/in_systm.h>
191590Srgrimes#include <netinet/in.h>
201590Srgrimes#include <net/if.h>
211590Srgrimes#include <netinet/if_ether.h>
221590Srgrimes#ifndef	ultrix
231590Srgrimes# include <net/if_arp.h>
241590Srgrimes#endif
251590Srgrimes#include <netinet/in.h>
261590Srgrimes#include <netinet/ip.h>
271590Srgrimes#include <netinet/ip_var.h>
281590Srgrimes#include <netinet/tcp.h>
291590Srgrimes#include <stdio.h>
301590Srgrimes#include <errno.h>
311590Srgrimes#include <netdb.h>
321590Srgrimes#include "ipsend.h"
331590Srgrimes#include "iplang/iplang.h"
341590Srgrimes
3519418Swosch
361590Srgrimes/*
371590Srgrimes * lookup host and return
3819418Swosch * its IP address in address
391590Srgrimes * (4 bytes)
4019418Swosch */
41int	resolve(host, address)
42	char	*host, *address;
43{
44        struct	hostent	*hp;
45        u_long	add;
46
47	add = inet_addr(host);
48	if (add == -1)
49	    {
50		if (!(hp = gethostbyname(host)))
51		    {
52			fprintf(stderr, "unknown host: %s\n", host);
53			return -1;
54		    }
55		bcopy((char *)hp->h_addr, (char *)address, 4);
56		return 0;
57	}
58	bcopy((char*)&add, address, 4);
59	return 0;
60}
61
62/*
63 * ARP for the MAC address corresponding
64 * to the IP address.  This taken from
65 * some BSD program, I cant remember which.
66 */
67int	arp(ip, ether)
68	char	*ip;
69	char	*ether;
70{
71	static	int	sfd = -1;
72	static	char	ethersave[6], ipsave[4];
73	struct	arpreq	ar;
74	struct	sockaddr_in	*sin, san;
75	struct	hostent	*hp;
76	int	fd;
77
78#ifdef	IPSEND
79	if (arp_getipv4(ip, ether) == 0)
80		return 0;
81#endif
82	if (!bcmp(ipsave, ip, 4)) {
83		bcopy(ethersave, ether, 6);
84		return 0;
85	}
86	fd = -1;
87	bzero((char *)&ar, sizeof(ar));
88	sin = (struct sockaddr_in *)&ar.arp_pa;
89	sin->sin_family = AF_INET;
90	bcopy(ip, (char *)&sin->sin_addr.s_addr, 4);
91#ifndef	hpux
92	if ((hp = gethostbyaddr(ip, 4, AF_INET)))
93# if SOLARIS && (SOLARIS2 >= 10)
94		if (!(ether_hostton(hp->h_name, (struct ether_addr *)ether)))
95# else
96		if (!(ether_hostton(hp->h_name, ether)))
97# endif
98			goto savearp;
99#endif
100
101	if (sfd == -1)
102		if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
103		    {
104			perror("arp: socket");
105			return -1;
106		    }
107tryagain:
108	if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1)
109	    {
110		if (fd == -1)
111		    {
112			bzero((char *)&san, sizeof(san));
113			san.sin_family = AF_INET;
114			san.sin_port = htons(1);
115			bcopy(ip, &san.sin_addr.s_addr, 4);
116			fd = socket(AF_INET, SOCK_DGRAM, 0);
117			(void) sendto(fd, ip, 4, 0,
118				      (struct sockaddr *)&san, sizeof(san));
119			sleep(1);
120			(void) close(fd);
121			goto tryagain;
122		    }
123		fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
124		if (errno != ENXIO)
125			perror("SIOCGARP");
126		return -1;
127	    }
128
129	if ((ar.arp_ha.sa_data[0] == 0) && (ar.arp_ha.sa_data[1] == 0) &&
130	    (ar.arp_ha.sa_data[2] == 0) && (ar.arp_ha.sa_data[3] == 0) &&
131	    (ar.arp_ha.sa_data[4] == 0) && (ar.arp_ha.sa_data[5] == 0)) {
132		fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
133		return -1;
134	}
135
136	bcopy(ar.arp_ha.sa_data, ether, 6);
137savearp:
138	bcopy(ether, ethersave, 6);
139	bcopy(ip, ipsave, 4);
140	return 0;
141}
142