ifaddrlist.c revision 100785 
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 "gnuc.h"
65#ifdef HAVE_OS_PROTO_H
66#include "os-proto.h"
67#endif
68
69#include "ifaddrlist.h"
70
71/*
72 * Return the interface list
73 */
74int
75ifaddrlist(register struct ifaddrlist **ipaddrp, register char *errbuf)
76{
77	register int fd, nipaddr;
78#ifdef HAVE_SOCKADDR_SA_LEN
79	register int n;
80#endif
81	register struct ifreq *ifrp, *ifend, *ifnext, *mp;
82	register struct sockaddr_in *sin;
83	register struct ifaddrlist *al;
84	struct ifconf ifc;
85	struct ifreq ibuf[(32 * 1024) / sizeof(struct ifreq)], ifr;
86#define MAX_IPADDR (sizeof(ibuf) / sizeof(ibuf[0]))
87	static struct ifaddrlist ifaddrlist[MAX_IPADDR];
88	char device[sizeof(ifr.ifr_name) + 1];
89
90	fd = socket(AF_INET, SOCK_DGRAM, 0);
91	if (fd < 0) {
92		(void)sprintf(errbuf, "socket: %s", strerror(errno));
93		return (-1);
94	}
95	ifc.ifc_len = sizeof(ibuf);
96	ifc.ifc_buf = (caddr_t)ibuf;
97
98	if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
99	    ifc.ifc_len < sizeof(struct ifreq)) {
100		if (errno == EINVAL)
101			(void)sprintf(errbuf,
102			    "SIOCGIFCONF: ifreq struct too small (%d bytes)",
103			    sizeof(ibuf));
104		else
105			(void)sprintf(errbuf, "SIOCGIFCONF: %s",
106			    strerror(errno));
107		(void)close(fd);
108		return (-1);
109	}
110	ifrp = ibuf;
111	ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
112
113	al = ifaddrlist;
114	mp = NULL;
115	nipaddr = 0;
116	for (; ifrp < ifend; ifrp = ifnext) {
117#ifdef HAVE_SOCKADDR_SA_LEN
118		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
119		if (n < sizeof(*ifrp))
120			ifnext = ifrp + 1;
121		else
122			ifnext = (struct ifreq *)((char *)ifrp + n);
123		if (ifrp->ifr_addr.sa_family != AF_INET)
124			continue;
125#else
126		ifnext = ifrp + 1;
127#endif
128		/*
129		 * Need a template to preserve address info that is
130		 * used below to locate the next entry.  (Otherwise,
131		 * SIOCGIFFLAGS stomps over it because the requests
132		 * are returned in a union.)
133		 */
134		strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
135		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
136			if (errno == ENXIO)
137				continue;
138			(void)sprintf(errbuf, "SIOCGIFFLAGS: %.*s: %s",
139			    (int)sizeof(ifr.ifr_name), ifr.ifr_name,
140			    strerror(errno));
141			(void)close(fd);
142			return (-1);
143		}
144
145		/* Must be up */
146		if ((ifr.ifr_flags & IFF_UP) == 0)
147			continue;
148
149
150		(void)strncpy(device, ifr.ifr_name, sizeof(ifr.ifr_name));
151		device[sizeof(device) - 1] = '\0';
152#ifdef sun
153		/* Ignore sun virtual interfaces */
154		if (strchr(device, ':') != NULL)
155			continue;
156#endif
157		if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
158			(void)sprintf(errbuf, "SIOCGIFADDR: %s: %s",
159			    device, strerror(errno));
160			(void)close(fd);
161			return (-1);
162		}
163
164		if (nipaddr >= MAX_IPADDR) {
165			(void)sprintf(errbuf, "Too many interfaces (%d)",
166			    MAX_IPADDR);
167			(void)close(fd);
168			return (-1);
169		}
170		sin = (struct sockaddr_in *)&ifr.ifr_addr;
171		al->addr = sin->sin_addr.s_addr;
172		al->device = strdup(device);
173		++al;
174		++nipaddr;
175	}
176	(void)close(fd);
177
178	*ipaddrp = ifaddrlist;
179	return (nipaddr);
180}
181