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ifaddrlist.c revision 1.10 
      1 /*	$NetBSD: ifaddrlist.c,v 1.10 2011/09/11 01:06:26 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997, 1998, 1999, 2000
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the Computer Systems
     18  *	Engineering Group at Lawrence Berkeley Laboratory.
     19  * 4. Neither the name of the University nor of the Laboratory may be used
     20  *    to endorse or promote products derived from this software without
     21  *    specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static const char rcsid[] =
     40     "@(#) Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp  (LBL)";
     41     "@(#) Id: ifaddrlist.c,v 1.9 2000/11/23 20:01:55 leres Exp  (LBL)";
     42 #else
     43 __RCSID("$NetBSD: ifaddrlist.c,v 1.10 2011/09/11 01:06:26 christos Exp $");
     44 #endif
     45 #endif
     46 
     47 #include <sys/param.h>
     48 #include <sys/file.h>
     49 #include <sys/ioctl.h>
     50 #include <sys/socket.h>
     51 #ifdef HAVE_SYS_SOCKIO_H
     52 #include <sys/sockio.h>
     53 #endif
     54 #include <sys/time.h>				/* concession to AIX */
     55 
     56 struct mbuf;
     57 struct rtentry;
     58 
     59 #include <net/if.h>
     60 #include <netinet/in.h>
     61 #include <arpa/inet.h>
     62 
     63 #include <ctype.h>
     64 #include <errno.h>
     65 #include <memory.h>
     66 #include <stdio.h>
     67 #include <stdlib.h>
     68 #include <string.h>
     69 #include <unistd.h>
     70 #include <ifaddrs.h>
     71 
     72 #include "gnuc.h"
     73 #ifdef HAVE_OS_PROTO_H
     74 #include "os-proto.h"
     75 #endif
     76 
     77 #include "ifaddrlist.h"
     78 
     79 /* Not all systems have IFF_LOOPBACK */
     80 #ifdef IFF_LOOPBACK
     81 #define ISLOOPBACK(p) ((p)->ifa_flags & IFF_LOOPBACK)
     82 #else
     83 #define ISLOOPBACK(p) (strcmp((p)->ifa_name, "lo0") == 0)
     84 #endif
     85 
     86 /*
     87  * Return the interface list
     88  */
     89 ssize_t
     90 ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, size_t buflen)
     91 {
     92 	struct sockaddr_in *sin;
     93 	struct ifaddrs *ifap = NULL, *ifa;
     94 	struct ifaddrlist *al = NULL, *nal;
     95 	size_t i = 0, maxal = 10;
     96 
     97 	if (getifaddrs(&ifap) != 0)
     98 		goto out;
     99 
    100 	if ((al = malloc(maxal * sizeof(*al))) == NULL)
    101 		goto out;
    102 
    103 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
    104 		if (ifa->ifa_addr->sa_family != AF_INET)
    105 			continue;
    106 
    107 		/* Must be up */
    108 		if ((ifa->ifa_flags & IFF_UP) == 0)
    109 			continue;
    110 
    111 		/*
    112 		 * Must not be a loopback address (127/8)
    113 		 */
    114 		sin = (struct sockaddr_in *)ifa->ifa_addr;
    115 		if (ISLOOPBACK(ifa))
    116 			if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK)
    117 				continue;
    118 
    119 		if (i == maxal) {
    120 			maxal <<= 1;
    121 			if ((nal = realloc(al, maxal * sizeof(*al))) == NULL)
    122 				goto out;
    123 			al = nal;
    124 		}
    125 
    126 		al[i].addr = sin->sin_addr.s_addr;
    127 		if ((al[i].device = strdup(ifa->ifa_name)) == NULL)
    128 			goto out;
    129 		i++;
    130 	}
    131 	if ((nal = realloc(al, i * sizeof(*al))) == NULL)
    132 		goto out;
    133 	freeifaddrs(ifap);
    134 	*ipaddrp = nal;
    135 	return (ssize_t)i;
    136 out:
    137 	if (ifap)
    138 		freeifaddrs(ifap);
    139 	if (al) {
    140 		while (i > 0)
    141 			free(al[--i].device);
    142 		free(al);
    143 	}
    144 	(void)snprintf(errbuf, buflen, "%s: %s", __func__, strerror(errno));
    145 	return -1;
    146 }
    147