1 /* $KAME: if_nametoindex.c,v 1.6 2000/11/24 08:18:54 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-1-Clause 5 * 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/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "namespace.h" 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 #include "un-namespace.h" 45 46 /* 47 * From RFC 2553: 48 * 49 * 4.1 Name-to-Index 50 * 51 * 52 * The first function maps an interface name into its corresponding 53 * index. 54 * 55 * #include <net/if.h> 56 * 57 * unsigned int if_nametoindex(const char *ifname); 58 * 59 * If the specified interface name does not exist, the return value is 60 * 0, and errno is set to ENXIO. If there was a system error (such as 61 * running out of memory), the return value is 0 and errno is set to the 62 * proper value (e.g., ENOMEM). 63 */ 64 65 unsigned int 66 if_nametoindex(const char *ifname) 67 { 68 int s; 69 struct ifreq ifr; 70 struct ifaddrs *ifaddrs, *ifa; 71 unsigned int ni; 72 73 s = _socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0); 74 if (s != -1) { 75 memset(&ifr, 0, sizeof(ifr)); 76 strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); 77 if (_ioctl(s, SIOCGIFINDEX, &ifr) != -1) { 78 _close(s); 79 return (ifr.ifr_index); 80 } 81 _close(s); 82 } 83 84 if (getifaddrs(&ifaddrs) < 0) 85 return(0); 86 87 ni = 0; 88 89 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { 90 if (ifa->ifa_addr && 91 ifa->ifa_addr->sa_family == AF_LINK && 92 strcmp(ifa->ifa_name, ifname) == 0) { 93 ni = LLINDEX((struct sockaddr_dl*)ifa->ifa_addr); 94 break; 95 } 96 } 97 98 freeifaddrs(ifaddrs); 99 if (!ni) 100 errno = ENXIO; 101 return(ni); 102 } 103