src/bin/network/traceroute/findsaddr-generic.c

   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
  35 static 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__
  48 struct mbuf;
  49 struct 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  */
  75 const char *
  76 findsaddr(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 }