xref: /netbsd-src/usr.sbin/traceroute/ifaddrlist.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*	$NetBSD: ifaddrlist.c,v 1.9 2011/05/11 00:38:28 christos 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 1.9 2011/05/11 00:38:28 christos 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 struct mbuf;
56 struct rtentry;
57 
58 #include <net/if.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
61 
62 #include <ctype.h>
63 #include <errno.h>
64 #include <memory.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include <ifaddrs.h>
70 
71 #include "gnuc.h"
72 #ifdef HAVE_OS_PROTO_H
73 #include "os-proto.h"
74 #endif
75 
76 #include "ifaddrlist.h"
77 
78 /* Not all systems have IFF_LOOPBACK */
79 #ifdef IFF_LOOPBACK
80 #define ISLOOPBACK(p) ((p)->ifa_flags & IFF_LOOPBACK)
81 #else
82 #define ISLOOPBACK(p) (strcmp((p)->ifa_name, "lo0") == 0)
83 #endif
84 
85 /*
86  * Return the interface list
87  */
88 ssize_t
89 ifaddrlist(struct ifaddrlist **ipaddrp, char *errbuf, size_t buflen)
90 {
91 	struct sockaddr_in *sin;
92 	struct ifaddrs *ifap = NULL, *ifa;
93 	struct ifaddrlist *al = NULL, *nal;
94 	size_t i = 0, maxal = 10;
95 
96 	if (getifaddrs(&ifap) != 0)
97 		goto out;
98 
99 	if ((al = malloc(maxal * sizeof(*al))) == NULL)
100 		goto out;
101 
102 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
103 		if (ifa->ifa_addr->sa_family != AF_INET)
104 			continue;
105 
106 		/* Must be up */
107 		if ((ifa->ifa_flags & IFF_UP) == 0)
108 			continue;
109 
110 		/*
111 		 * Must not be a loopback address (127/8)
112 		 */
113 		sin = (struct sockaddr_in *)ifa->ifa_addr;
114 		if (ISLOOPBACK(ifa))
115 			if (ntohl(sin->sin_addr.s_addr) == INADDR_LOOPBACK)
116 				continue;
117 
118 		if (i == maxal) {
119 			maxal <<= 1;
120 			if ((nal = realloc(al, maxal * sizeof(*al))) == NULL)
121 				goto out;
122 			al = nal;
123 		}
124 
125 		al[i].addr = sin->sin_addr.s_addr;
126 		if ((al[i].device = strdup(ifa->ifa_name)) == NULL)
127 			goto out;
128 		i++;
129 	}
130 	if ((nal = realloc(al, i * sizeof(*al))) == NULL)
131 		goto out;
132 	freeifaddrs(ifap);
133 	*ipaddrp = nal;
134 	return (ssize_t)i;
135 out:
136 	if (ifap)
137 		freeifaddrs(ifap);
138 	if (al) {
139 		while (i > 0)
140 			free(al[--i].device);
141 		free(al);
142 	}
143 	(void)snprintf(errbuf, buflen, "%s: %s", __func__, strerror(errno));
144 	return -1;
145 }
146