1 /* $OpenBSD: if_nametoindex.c,v 1.10 2015/10/23 13:09:19 claudio Exp $ */
2 /* $KAME: if_nametoindex.c,v 1.5 2000/11/24 08:04:40 itojun Exp $ */
3
4 /*-
5 * Copyright (c) 2015 Claudio Jeker <claudio@openbsd.org>
6 * Copyright (c) 1997, 2000
7 * Berkeley Software Design, Inc. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
28 */
29
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <net/if.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <errno.h>
36
37 /*
38 * From RFC 2553:
39 *
40 * 4.1 Name-to-Index
41 *
42 *
43 * The first function maps an interface name into its corresponding
44 * index.
45 *
46 * #include <net/if.h>
47 *
48 * unsigned int if_nametoindex(const char *ifname);
49 *
50 * If the specified interface name does not exist, the return value is
51 * 0, and errno is set to ENXIO. If there was a system error (such as
52 * running out of memory), the return value is 0 and errno is set to the
53 * proper value (e.g., ENOMEM).
54 */
55
56 unsigned int
if_nametoindex(const char * ifname)57 if_nametoindex(const char *ifname)
58 {
59 struct if_nameindex *ifni, *ifni2;
60 unsigned int index;
61
62 if ((ifni = if_nameindex()) == NULL)
63 return(0);
64
65 for (ifni2 = ifni; ifni2->if_index != 0; ifni2++) {
66 if (strcmp(ifni2->if_name, ifname) == 0) {
67 index = ifni2->if_index;
68 if_freenameindex(ifni);
69 return index;
70 }
71 }
72
73 if_freenameindex(ifni);
74 errno = ENXIO;
75 return 0;
76 }
77 DEF_WEAK(if_nametoindex);
78