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
35 static 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__
49 struct mbuf;
50 struct 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  */
69 int
ifaddrlist(register struct ifaddrlist ** ipaddrp,register char * errbuf)70 ifaddrlist(register struct ifaddrlist **ipaddrp, register char *errbuf)
71 {
72 	register int fd, nipaddr;
73 #ifdef HAVE_SOCKADDR_SA_LEN
74 	size_t n;
75 #endif
76 	register struct ifreq *ifrp, *ifend, *ifnext;
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 ((int)(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 < (int)sizeof(struct ifreq)) {
95 		if (errno == EINVAL)
96 			(void)sprintf(errbuf,
97 			    "SIOCGIFCONF: ifreq struct too small (%zu 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 	nipaddr = 0;
110 	for (; ifrp < ifend; ifrp = ifnext) {
111 #ifdef HAVE_SOCKADDR_SA_LEN
112 		n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
113 		if (n < sizeof(*ifrp))
114 			ifnext = ifrp + 1;
115 		else
116 			ifnext = (struct ifreq *)((char *)ifrp + n);
117 		if (ifrp->ifr_addr.sa_family != AF_INET)
118 			continue;
119 #else
120 		ifnext = ifrp + 1;
121 #endif
122 		/*
123 		 * Need a template to preserve address info that is
124 		 * used below to locate the next entry.  (Otherwise,
125 		 * SIOCGIFFLAGS stomps over it because the requests
126 		 * are returned in a union.)
127 		 */
128 		strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
129 		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
130 			if (errno == ENXIO)
131 				continue;
132 			(void)sprintf(errbuf, "SIOCGIFFLAGS: %.*s: %s",
133 			    (int)sizeof(ifr.ifr_name), ifr.ifr_name,
134 			    strerror(errno));
135 			(void)close(fd);
136 			return (-1);
137 		}
138 
139 		/* Must be up */
140 		if ((ifr.ifr_flags & IFF_UP) == 0)
141 			continue;
142 
143 
144 		(void)strncpy(device, ifr.ifr_name, sizeof(ifr.ifr_name));
145 		device[sizeof(device) - 1] = '\0';
146 #ifdef sun
147 		/* Ignore sun virtual interfaces */
148 		if (strchr(device, ':') != NULL)
149 			continue;
150 #endif
151 		if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
152 			(void)sprintf(errbuf, "SIOCGIFADDR: %s: %s",
153 			    device, strerror(errno));
154 			(void)close(fd);
155 			return (-1);
156 		}
157 
158 		if (nipaddr >= MAX_IPADDR) {
159 			(void)sprintf(errbuf, "Too many interfaces (%d)",
160 			    MAX_IPADDR);
161 			(void)close(fd);
162 			return (-1);
163 		}
164 		sin = (struct sockaddr_in *)&ifr.ifr_addr;
165 		al->addr = sin->sin_addr.s_addr;
166 		al->device = strdup(device);
167 		++al;
168 		++nipaddr;
169 	}
170 	(void)close(fd);
171 
172 	*ipaddrp = ifaddrlist;
173 	return (nipaddr);
174 }
175