Libinfo-517.200.9.tar.gz
[apple/libinfo.git] / gen.subproj / if_nametoindex.c
1 /*
2 * Copyright (c) 2018 Apple Inc. All rights reserved.
3 */
4 /* $KAME: if_nametoindex.c,v 1.6 2000/11/24 08:18:54 itojun Exp $ */
5
6 /*-
7 * Copyright (c) 1997, 2000
8 * Berkeley Software Design, Inc. 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 *
16 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
29 */
30
31 #include "libinfo_common.h"
32
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <net/if.h>
36 #include <net/if_dl.h>
37 #include <ifaddrs.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <errno.h>
41
42 /*
43 * From RFC 2553:
44 *
45 * 4.1 Name-to-Index
46 *
47 *
48 * The first function maps an interface name into its corresponding
49 * index.
50 *
51 * #include <net/if.h>
52 *
53 * unsigned int if_nametoindex(const char *ifname);
54 *
55 * If the specified interface name does not exist, the return value is
56 * 0, and errno is set to ENXIO. If there was a system error (such as
57 * running out of memory), the return value is 0 and errno is set to the
58 * proper value (e.g., ENOMEM).
59 */
60
61 LIBINFO_EXPORT
62 unsigned int
63 if_nametoindex(const char *ifname)
64 {
65 struct ifaddrs *ifaddrs, *ifa;
66 unsigned int ni;
67
68 if (getifaddrs(&ifaddrs) < 0)
69 return(0);
70
71 ni = 0;
72
73 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
74 if (ifa->ifa_addr &&
75 ifa->ifa_addr->sa_family == AF_LINK &&
76 strcmp(ifa->ifa_name, ifname) == 0) {
77 ni = ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index;
78 break;
79 }
80 }
81
82 freeifaddrs(ifaddrs);
83 if (!ni)
84 errno = ENXIO;
85 return(ni);
86 }