ifaddrlist.c revision 215937 
1/*
2 * Copyright (c) 1997, 1998, 1999, 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: ifaddrlist.c,v 1.9 2000/11/23 20:01:55 leres Exp $ (LBL)";
37#endif
38
39#include <sys/param.h>
40#include <sys/file.h>
41#include <sys/ioctl.h>
42#include <sys/socket.h>
43#ifdef HAVE_SYS_SOCKIO_H
44#include <sys/sockio.h>
45#endif
46#include <sys/time.h>				/* concession to AIX */
47
48#if __STDC__
49struct mbuf;
50struct rtentry;
51#endif
52
53#include <net/if.h>
54#include <netinet/in.h>
55
56#include <ctype.h>
57#include <errno.h>
58#include <memory.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <unistd.h>
63
64#include "ifaddrlist.h"
65
66/*
67 * Return the interface list
68 */
69int
70ifaddrlist(register struct ifaddrlist **ipaddrp, register char *errbuf)
71{
72	register int fd, nipaddr;
73#ifdef HAVE_SOCKADDR_SA_LEN
74	register int n;
75#endif
76	register struct ifreq *ifrp, *ifend, *ifnext, *mp;
77	register struct sockaddr_in *sin;
78	register struct ifaddrlist *al;
79	struct ifconf ifc;
80	struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
81#define MAX_IPADDR (sizeof(ibuf) / sizeof(ibuf[0]))
82	static struct ifaddrlist ifaddrlist[MAX_IPADDR];
83	char device[sizeof(ifr.ifr_name) + 1];
84
85	fd = socket(AF_INET, SOCK_DGRAM, 0);
86	if (fd < 0) {
87		(void)sprintf(errbuf, "socket: %s", strerror(errno));
88		return (-1);
89	}
90	ifc.ifc_len = sizeof(ibuf);
91	ifc.ifc_buf = (caddr_t)ibuf;
92
93	if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
94	    ifc.ifc_len < sizeof(struct ifreq)) {
95		if (errno == EINVAL)
96			(void)sprintf(errbuf,
97			    "SIOCGIFCONF: ifreq struct too small (%d bytes)",
98			    sizeof(ibuf));
99		else
100			(void)sprintf(errbuf, "SIOCGIFCONF: %s",
101			    strerror(errno));
102		(void)close(fd);
103		return (-1);
104	}
105	ifrp = ibuf;
106	ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
107
108	al = ifaddrlist;
109	mp = NULL;
110	nipaddr = 0;
111	for (; ifrp < ifend; ifrp = ifnext) {
112#ifdef HAVE_SOCKADDR_SA_LEN
113		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
114		if (n < sizeof(*ifrp))
115			ifnext = ifrp + 1;
116		else
117			ifnext = (struct ifreq *)((char *)ifrp + n);
118		if (ifrp->ifr_addr.sa_family != AF_INET)
119			continue;
120#else
121		ifnext = ifrp + 1;
122#endif
123		/*
124		 * Need a template to preserve address info that is
125		 * used below to locate the next entry.  (Otherwise,
126		 * SIOCGIFFLAGS stomps over it because the requests
127		 * are returned in a union.)
128		 */
129		strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
130		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
131			if (errno == ENXIO)
132				continue;
133			(void)sprintf(errbuf, "SIOCGIFFLAGS: %.*s: %s",
134			    (int)sizeof(ifr.ifr_name), ifr.ifr_name,
135			    strerror(errno));
136			(void)close(fd);
137			return (-1);
138		}
139
140		/* Must be up */
141		if ((ifr.ifr_flags & IFF_UP) == 0)
142			continue;
143
144
145		(void)strncpy(device, ifr.ifr_name, sizeof(ifr.ifr_name));
146		device[sizeof(device) - 1] = '\0';
147#ifdef sun
148		/* Ignore sun virtual interfaces */
149		if (strchr(device, ':') != NULL)
150			continue;
151#endif
152		if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
153			(void)sprintf(errbuf, "SIOCGIFADDR: %s: %s",
154			    device, strerror(errno));
155			(void)close(fd);
156			return (-1);
157		}
158
159		if (nipaddr >= MAX_IPADDR) {
160			(void)sprintf(errbuf, "Too many interfaces (%d)",
161			    MAX_IPADDR);
162			(void)close(fd);
163			return (-1);
164		}
165		sin = (struct sockaddr_in *)&ifr.ifr_addr;
166		al->addr = sin->sin_addr.s_addr;
167		al->device = strdup(device);
168		++al;
169		++nipaddr;
170	}
171	(void)close(fd);
172
173	*ipaddrp = ifaddrlist;
174	return (nipaddr);
175}
176