1 /* $NetBSD: if_nametoindex.c,v 1.5 2015/09/01 09:54:34 ozaki-r Exp $ */
2 /* $KAME: if_nametoindex.c,v 1.6 2000/11/24 08:18:54 itojun Exp $ */
3
4 /*-
5 * Copyright (c) 1997, 2000
6 * Berkeley Software Design, Inc. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
27 */
28
29 #include <sys/cdefs.h>
30 #if defined(LIBC_SCCS) && !defined(lint)
31 __RCSID("$NetBSD: if_nametoindex.c,v 1.5 2015/09/01 09:54:34 ozaki-r Exp $");
32 #endif /* LIBC_SCCS and not lint */
33
34 #ifndef RUMP_ACTION
35 #include "namespace.h"
36 #endif
37 #include <sys/types.h>
38 #include <sys/socket.h>
39 #include <net/if.h>
40 #include <net/if_dl.h>
41 #include <ifaddrs.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <errno.h>
45
46 #ifndef RUMP_ACTION
47 #ifdef __weak_alias
__weak_alias(if_nametoindex,_if_nametoindex)48 __weak_alias(if_nametoindex,_if_nametoindex)
49 #endif
50 #endif
51
52 /*
53 * From RFC 2553:
54 *
55 * 4.1 Name-to-Index
56 *
57 *
58 * The first function maps an interface name into its corresponding
59 * index.
60 *
61 * #include <net/if.h>
62 *
63 * unsigned int if_nametoindex(const char *ifname);
64 *
65 * If the specified interface name does not exist, the return value is
66 * 0, and errno is set to ENXIO. If there was a system error (such as
67 * running out of memory), the return value is 0 and errno is set to the
68 * proper value (e.g., ENOMEM).
69 */
70
71 unsigned int
72 if_nametoindex(const char *ifname)
73 {
74 struct ifaddrs *ifaddrs, *ifa;
75 unsigned int ni;
76
77 if (getifaddrs(&ifaddrs) < 0)
78 return(0);
79
80 ni = 0;
81
82 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
83 if (ifa->ifa_addr &&
84 ifa->ifa_addr->sa_family == AF_LINK &&
85 strcmp(ifa->ifa_name, ifname) == 0) {
86 ni = ((struct sockaddr_dl*)
87 (void *)ifa->ifa_addr)->sdl_index;
88 break;
89 }
90 }
91
92 freeifaddrs(ifaddrs);
93 if (!ni)
94 errno = ENXIO;
95 return(ni);
96 }
97