1/*
2 * Copyright (c) 2000
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the Computer Systems
16 *	Engineering Group at Lawrence Berkeley Laboratory.
17 * 4. Neither the name of the University nor of the Laboratory may be used
18 *    to endorse or promote products derived from this software without
19 *    specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char rcsid[] =
36    "@(#) $Id: findsaddr-generic.c,v 1.1 2000/11/23 20:17:12 leres Exp $ (LBL)";
37#endif
38
39#include <sys/param.h>
40#include <sys/ioctl.h>
41#include <sys/socket.h>
42#ifdef HAVE_SYS_SOCKIO_H
43#include <sys/sockio.h>
44#endif
45#include <sys/time.h>				/* concession to AIX */
46
47#if __STDC__
48struct mbuf;
49struct rtentry;
50#endif
51
52#include <net/if.h>
53#include <netinet/in.h>
54
55#include <arpa/inet.h>
56
57#include <errno.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <string.h>
61#include <unistd.h>
62
63#include "gnuc.h"
64#ifdef HAVE_OS_PROTO_H
65#include "os-proto.h"
66#endif
67
68#include "findsaddr.h"
69#include "ifaddrlist.h"
70#include "traceroute.h"
71
72/*
73 * Return the source address for the given destination address
74 */
75const char *
76findsaddr(register const struct sockaddr_in *to,
77    register struct sockaddr_in *from)
78{
79	register int n;
80	struct ifaddrlist *al;
81	static char errbuf[132];
82
83        /* Get the interface address list */
84	if ((n = ifaddrlist(&al, errbuf)) < 0)
85		return (errbuf);
86
87	if (n == 0)
88		return ("Can't find any network interfaces");
89
90	setsin(from, al->addr);
91	if (n > 1)
92		fprintf(stderr,
93		    "%s: Warning: Multiple interfaces found; using %s @ %s\n",
94		    prog, inet_ntoa(from->sin_addr), al->device);
95	return (NULL);
96}
97