1 /* $KAME: if_indextoname.c,v 1.7 2000/11/08 03:09:30 itojun Exp $ */
4 * Copyright (c) 1997, 2000
5 * Berkeley Software Design, Inc. All rights reserved.
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8 * modification, are permitted provided that the following conditions
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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
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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
25 * BSDI Id: if_indextoname.c,v 2.3 2000/04/17 22:38:05 dab Exp
27 * $FreeBSD: src/lib/libc/net/if_indextoname.c,v 1.1.2.1 2002/07/29 18:33:18 ume Exp $
28 * $DragonFly: src/lib/libc/net/if_indextoname.c,v 1.2 2003/06/17 04:26:44 dillon Exp $
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <net/if_dl.h>
43 * The second function maps an interface index into its corresponding
48 * char *if_indextoname(unsigned int ifindex, char *ifname);
50 * The ifname argument must point to a buffer of at least IF_NAMESIZE
51 * bytes into which the interface name corresponding to the specified
52 * index is returned. (IF_NAMESIZE is also defined in <net/if.h> and
53 * its value includes a terminating null byte at the end of the
54 * interface name.) This pointer is also the return value of the
55 * function. If there is no interface corresponding to the specified
56 * index, NULL is returned, and errno is set to ENXIO, if there was a
57 * system error (such as running out of memory), if_indextoname returns
58 * NULL and errno would be set to the proper value (e.g., ENOMEM).
62 if_indextoname(unsigned int ifindex, char *ifname)
64 struct ifaddrs *ifaddrs, *ifa;
67 if (getifaddrs(&ifaddrs) < 0)
68 return(NULL); /* getifaddrs properly set errno */
70 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
72 ifa->ifa_addr->sa_family == AF_LINK &&
73 ifindex == ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index)
82 strncpy(ifname, ifa->ifa_name, IFNAMSIZ);