1 /* $KAME: if_nametoindex.c,v 1.6 2000/11/24 08:18:54 itojun Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 2000
5 * Berkeley Software Design, Inc. 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 *
13 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * BSDI Id: if_nametoindex.c,v 2.3 2000/04/17 22:38:05 dab Exp
26 */
27
28 #include <sys/cdefs.h>
29 #ifndef FSTACK
30 __FBSDID("$FreeBSD$");
31
32 #include "namespace.h"
33 #endif
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <sys/sockio.h>
37 #include <net/if.h>
38 #include <net/if_dl.h>
39 #include <ifaddrs.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <errno.h>
43 #include <unistd.h>
44 #ifndef FSTACK
45 #include "un-namespace.h"
46 #endif
47
48 #ifdef FSTACK
49 #include "compat.h"
50
51 #define _socket(a, b, c) 0
52 #define _ioctl(a, b, c) ioctl((a), (b), (c))
53 #define _close(s)
54 #endif
55
56 /*
57 * From RFC 2553:
58 *
59 * 4.1 Name-to-Index
60 *
61 *
62 * The first function maps an interface name into its corresponding
63 * index.
64 *
65 * #include <net/if.h>
66 *
67 * unsigned int if_nametoindex(const char *ifname);
68 *
69 * If the specified interface name does not exist, the return value is
70 * 0, and errno is set to ENXIO. If there was a system error (such as
71 * running out of memory), the return value is 0 and errno is set to the
72 * proper value (e.g., ENOMEM).
73 */
74
75 unsigned int
if_nametoindex(const char * ifname)76 if_nametoindex(const char *ifname)
77 {
78 int s;
79 struct ifreq ifr;
80 struct ifaddrs *ifaddrs, *ifa;
81 unsigned int ni;
82
83 s = _socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
84 if (s != -1) {
85 memset(&ifr, 0, sizeof(ifr));
86 strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
87 if (_ioctl(s, SIOCGIFINDEX, &ifr) != -1) {
88 _close(s);
89 return (ifr.ifr_index);
90 }
91 _close(s);
92 }
93
94 if (getifaddrs(&ifaddrs) < 0)
95 return(0);
96
97 ni = 0;
98
99 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
100 if (ifa->ifa_addr &&
101 ifa->ifa_addr->sa_family == AF_LINK &&
102 strcmp(ifa->ifa_name, ifname) == 0) {
103 ni = LLINDEX((struct sockaddr_dl*)ifa->ifa_addr);
104 break;
105 }
106 }
107
108 freeifaddrs(ifaddrs);
109 if (!ni)
110 errno = ENXIO;
111 return(ni);
112 }
113