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ifaddrlist.c revision 1.4
      1 /*	$NetBSD: ifaddrlist.c,v 1.4 2000/04/13 07:53:29 itojun Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997
      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 #else
     42 __RCSID("$NetBSD: ifaddrlist.c,v 1.4 2000/04/13 07:53:29 itojun Exp $");
     43 #endif
     44 #endif
     45 
     46 #include <sys/param.h>
     47 #include <sys/file.h>
     48 #include <sys/ioctl.h>
     49 #include <sys/socket.h>
     50 #ifdef HAVE_SYS_SOCKIO_H
     51 #include <sys/sockio.h>
     52 #endif
     53 #include <sys/time.h>				/* concession to AIX */
     54 
     55 #if __STDC__
     56 struct mbuf;
     57 struct rtentry;
     58 #endif
     59 
     60 #include <net/if.h>
     61 #include <netinet/in.h>
     62 #include <arpa/inet.h>
     63 
     64 #include <ctype.h>
     65 #include <errno.h>
     66 #include <memory.h>
     67 #include <stdio.h>
     68 #include <stdlib.h>
     69 #include <string.h>
     70 #include <unistd.h>
     71 #ifdef HAVE_IFADDRS_H
     72 #include <ifaddrs.h>
     73 #endif
     74 
     75 #include "gnuc.h"
     76 #ifdef HAVE_OS_PROTO_H
     77 #include "os-proto.h"
     78 #endif
     79 
     80 #include "ifaddrlist.h"
     81 #include "savestr.h"
     82 
     83 
     84 /* Not all systems have IFF_LOOPBACK */
     85 #ifdef HAVE_IFADDRS_H
     86 #ifdef IFF_LOOPBACK
     87 #define ISLOOPBACK(p) ((p)->ifa_flags & IFF_LOOPBACK)
     88 #else
     89 #define ISLOOPBACK(p) (strcmp((p)->ifa_name, "lo0") == 0)
     90 #endif
     91 #else
     92 #ifdef IFF_LOOPBACK
     93 #define ISLOOPBACK(p) ((p)->ifr_flags & IFF_LOOPBACK)
     94 #else
     95 #define ISLOOPBACK(p) (strcmp((p)->ifr_name, "lo0") == 0)
     96 #endif
     97 #endif
     98 
     99 #define MAX_IPADDR 256
    100 
    101 /*
    102  * Return the interface list
    103  */
    104 int
    105 ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, int buflen)
    106 {
    107 #ifdef HAVE_IFADDRS_H
    108 	int nipaddr;
    109 	struct sockaddr_in *sin;
    110 	struct ifaddrs *ifap, *ifa;
    111 	struct ifaddrlist *al;
    112 	static struct ifaddrlist ifaddrlist[MAX_IPADDR];
    113 
    114 	al = ifaddrlist;
    115 	nipaddr = 0;
    116 
    117 	if (getifaddrs(&ifap) != 0) {
    118 		(void)snprintf(errbuf, buflen, "getifaddrs: %s",
    119 		    strerror(errno));
    120 		return (-1);
    121 	}
    122 
    123 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
    124 		if (ifa->ifa_addr->sa_family != AF_INET)
    125 			continue;
    126 
    127 		/* Must be up */
    128 		if ((ifa->ifa_flags & IFF_UP) == 0)
    129 			continue;
    130 
    131 		/*
    132 		 * Must not be a loopback address (127/8)
    133 		 */
    134 		sin = (struct sockaddr_in *)ifa->ifa_addr;
    135 		if (ISLOOPBACK(ifa))
    136 			if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK)
    137 				continue;
    138 
    139 		al->addr = sin->sin_addr.s_addr;
    140 		al->device = savestr(ifa->ifa_name);
    141 		++al;
    142 		++nipaddr;
    143 	}
    144 	*ipaddrp = ifaddrlist;
    145 	freeifaddrs(ifap);
    146 	return (nipaddr);
    147 #else
    148 	int fd, nipaddr;
    149 #ifdef HAVE_SOCKADDR_SA_LEN
    150 	int n;
    151 #endif
    152 	struct ifreq *ifrp, *ifend, *ifnext, *mp;
    153 	struct sockaddr_in *sin;
    154 	struct ifaddrlist *al;
    155 	struct ifconf ifc;
    156 	struct ifreq ibuf[MAX_IPADDR], ifr;
    157 	char device[sizeof(ifr.ifr_name) + 1];
    158 	static struct ifaddrlist ifaddrlist[MAX_IPADDR];
    159 
    160 	fd = socket(AF_INET, SOCK_DGRAM, 0);
    161 	if (fd < 0) {
    162 		(void)snprintf(errbuf, buflen, "socket: %s", strerror(errno));
    163 		return (-1);
    164 	}
    165 	ifc.ifc_len = sizeof(ibuf);
    166 	ifc.ifc_buf = (caddr_t)ibuf;
    167 
    168 	if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
    169 	    ifc.ifc_len < sizeof(struct ifreq)) {
    170 		(void)snprintf(errbuf, buflen, "SIOCGIFCONF: %s", strerror(errno));
    171 		(void)close(fd);
    172 		return (-1);
    173 	}
    174 	ifrp = ibuf;
    175 	ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
    176 
    177 	al = ifaddrlist;
    178 	mp = NULL;
    179 	nipaddr = 0;
    180 	for (; ifrp < ifend; ifrp = ifnext) {
    181 #ifdef HAVE_SOCKADDR_SA_LEN
    182 		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
    183 		if (n < sizeof(*ifrp))
    184 			ifnext = ifrp + 1;
    185 		else
    186 			ifnext = (struct ifreq *)((char *)ifrp + n);
    187 		if (ifrp->ifr_addr.sa_family != AF_INET)
    188 			continue;
    189 #else
    190 		ifnext = ifrp + 1;
    191 #endif
    192 		/*
    193 		 * Need a template to preserve address info that is
    194 		 * used below to locate the next entry.  (Otherwise,
    195 		 * SIOCGIFFLAGS stomps over it because the requests
    196 		 * are returned in a union.)
    197 		 */
    198 		strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
    199 		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
    200 			if (errno == ENXIO)
    201 				continue;
    202 			(void)snprintf(errbuf, buflen, "SIOCGIFFLAGS: %.*s: %s",
    203 			    (int)sizeof(ifr.ifr_name), ifr.ifr_name,
    204 			    strerror(errno));
    205 			(void)close(fd);
    206 			return (-1);
    207 		}
    208 
    209 		/* Must be up */
    210 		if ((ifr.ifr_flags & IFF_UP) == 0)
    211 			continue;
    212 
    213 		/*
    214 		 * Must not be a loopback address (127/8)
    215 		 */
    216 		sin = (struct sockaddr_in *)&ifrp->ifr_addr;
    217 		if (ISLOOPBACK(&ifr))
    218 			if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK)
    219 				continue;
    220 
    221 		(void)strncpy(device, ifrp->ifr_name, sizeof(ifrp->ifr_name));
    222 		device[sizeof(device) - 1] = '\0';
    223 
    224 		al->addr = sin->sin_addr.s_addr;
    225 		al->device = savestr(device);
    226 		++al;
    227 		++nipaddr;
    228 	}
    229 	(void)close(fd);
    230 
    231 	*ipaddrp = ifaddrlist;
    232 	return (nipaddr);
    233 #endif
    234 }
    235