xref: /illumos-gate/usr/src/lib/libinetutil/common/ifaddrlist.c (revision 5bbb4db2c3f208d12bf0fd11769728f9e5ba66a2)
1 /*
2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1997
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the Computer Systems
21  *	Engineering Group at Lawrence Berkeley Laboratory.
22  * 4. Neither the name of the University nor of the Laboratory may be used
23  *    to endorse or promote products derived from this software without
24  *    specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * @(#) $Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp $ (LBL)
39  */
40 
41 #include <errno.h>
42 #include <libinetutil.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 
50 /*
51  * See <libinetutil.h> for a description of the programming interface.
52  */
53 int
54 ifaddrlist(struct ifaddrlist **ipaddrp, int family, uint_t flags, char *errbuf)
55 {
56 	struct ifaddrlist	*ifaddrlist = NULL, *al = NULL;
57 	struct sockaddr_in	*sin;
58 	struct sockaddr_in6	*sin6;
59 	struct lifconf		lifc;
60 	struct lifnum		lifn;
61 	struct lifreq		*lifrp;
62 	int			i, count, nlifr;
63 	int			fd;
64 	const char		*opstr;
65 
66 	(void) memset(&lifc, 0, sizeof (lifc));
67 	if (family != AF_INET && family != AF_INET6) {
68 		(void) strlcpy(errbuf, "invalid address family", ERRBUFSIZE);
69 		return (-1);
70 	}
71 
72 	if ((fd = socket(family, SOCK_DGRAM, 0)) == -1) {
73 		opstr = "socket";
74 		goto fail;
75 	}
76 
77 	/*
78 	 * Get the number of network interfaces of type `family'.
79 	 */
80 	lifn.lifn_family = family;
81 	lifn.lifn_flags = flags;
82 again:
83 	if (ioctl(fd, SIOCGLIFNUM, &lifn) == -1) {
84 		opstr = "SIOCGLIFNUM";
85 		goto fail;
86 	}
87 
88 	/*
89 	 * Pad the interface count to detect when additional interfaces have
90 	 * been configured between SIOCGLIFNUM and SIOCGLIFCONF.
91 	 */
92 	lifn.lifn_count += 4;
93 
94 	lifc.lifc_flags = flags;
95 	lifc.lifc_family = family;
96 	lifc.lifc_len = lifn.lifn_count * sizeof (struct lifreq);
97 	if ((lifc.lifc_buf = realloc(lifc.lifc_buf, lifc.lifc_len)) == NULL) {
98 		opstr = "realloc";
99 		goto fail;
100 	}
101 
102 	if (ioctl(fd, SIOCGLIFCONF, &lifc) == -1) {
103 		opstr = "SIOCGLIFCONF";
104 		goto fail;
105 	}
106 
107 	/*
108 	 * If every lifr_req slot is taken, then additional interfaces must
109 	 * have been plumbed between the SIOCGLIFNUM and the SIOCGLIFCONF.
110 	 * Recalculate to make sure we didn't miss any interfaces.
111 	 */
112 	nlifr = lifc.lifc_len / sizeof (struct lifreq);
113 	if (nlifr >= lifn.lifn_count)
114 		goto again;
115 
116 	/*
117 	 * Allocate the address list to return.
118 	 */
119 	if ((ifaddrlist = calloc(nlifr, sizeof (struct ifaddrlist))) == NULL) {
120 		opstr = "calloc";
121 		goto fail;
122 	}
123 
124 	/*
125 	 * Populate the address list by querying each underlying interface.
126 	 * If a query ioctl returns ENXIO, then the interface must have been
127 	 * removed after the SIOCGLIFCONF completed -- so we just ignore it.
128 	 */
129 	al = ifaddrlist;
130 	count = 0;
131 	for (lifrp = lifc.lifc_req, i = 0; i < nlifr; i++, lifrp++) {
132 		(void) strlcpy(al->device, lifrp->lifr_name, LIFNAMSIZ);
133 
134 		if (ioctl(fd, SIOCGLIFFLAGS, lifrp) == -1) {
135 			if (errno == ENXIO)
136 				continue;
137 			opstr = "SIOCGLIFFLAGS";
138 			goto fail;
139 		}
140 		al->flags = lifrp->lifr_flags;
141 
142 		if (ioctl(fd, SIOCGLIFINDEX, lifrp) == -1) {
143 			if (errno == ENXIO)
144 				continue;
145 			opstr = "SIOCGLIFINDEX";
146 			goto fail;
147 		}
148 		al->index = lifrp->lifr_index;
149 
150 		if (ioctl(fd, SIOCGLIFADDR, lifrp) == -1) {
151 			if (errno == ENXIO)
152 				continue;
153 			opstr = "SIOCGLIFADDR";
154 			goto fail;
155 		}
156 
157 		if (family == AF_INET) {
158 			sin = (struct sockaddr_in *)&lifrp->lifr_addr;
159 			al->addr.addr = sin->sin_addr;
160 		} else {
161 			sin6 = (struct sockaddr_in6 *)&lifrp->lifr_addr;
162 			al->addr.addr6 = sin6->sin6_addr;
163 		}
164 		al++;
165 		count++;
166 	}
167 
168 	(void) close(fd);
169 	free(lifc.lifc_buf);
170 	if (count == 0) {
171 		free(ifaddrlist);
172 		*ipaddrp = NULL;
173 		return (0);
174 	}
175 
176 	*ipaddrp = ifaddrlist;
177 	return (count);
178 fail:
179 	if (al == NULL) {
180 		(void) snprintf(errbuf, ERRBUFSIZE, "%s: %s", opstr,
181 		    strerror(errno));
182 	} else {
183 		(void) snprintf(errbuf, ERRBUFSIZE, "%s: %s: %s", opstr,
184 		    al->device, strerror(errno));
185 	}
186 	free(lifc.lifc_buf);
187 	free(ifaddrlist);
188 	(void) close(fd);
189 	return (-1);
190 }
191