1 /* $NetBSD: if_nametoindex.c,v 1.4 2000/11/24 08:21:12 itojun 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 1.4 2000/11/24 08:21:12 itojun Exp $"); 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include "namespace.h" 35 #include <sys/types.h> 36 #include <sys/socket.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 44 #ifdef __weak_alias 45 __weak_alias(if_nametoindex,_if_nametoindex) 46 #endif 47 48 /* 49 * From RFC 2553: 50 * 51 * 4.1 Name-to-Index 52 * 53 * 54 * The first function maps an interface name into its corresponding 55 * index. 56 * 57 * #include <net/if.h> 58 * 59 * unsigned int if_nametoindex(const char *ifname); 60 * 61 * If the specified interface name does not exist, the return value is 62 * 0, and errno is set to ENXIO. If there was a system error (such as 63 * running out of memory), the return value is 0 and errno is set to the 64 * proper value (e.g., ENOMEM). 65 */ 66 67 unsigned int 68 if_nametoindex(const char *ifname) 69 { 70 struct ifaddrs *ifaddrs, *ifa; 71 unsigned int ni; 72 73 if (getifaddrs(&ifaddrs) < 0) 74 return(0); 75 76 ni = 0; 77 78 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 79 if (ifa->ifa_addr && 80 ifa->ifa_addr->sa_family == AF_LINK && 81 strcmp(ifa->ifa_name, ifname) == 0) { 82 ni = ((struct sockaddr_dl*) 83 (void *)ifa->ifa_addr)->sdl_index; 84 break; 85 } 86 } 87 88 freeifaddrs(ifaddrs); 89 if (!ni) 90 errno = ENXIO; 91 return(ni); 92 } 93