projects / apple / libinfo.git / blame
| Commit | Line | Data |
|---|---|---|
| f475de6c A |
1 | /* |
| 2 | * Copyright (c) 2018 Apple Inc. All rights reserved. | |
| 3 | */ | |
| 3b7c7bd7 A |
4 | /* $KAME: if_indextoname.c,v 1.7 2000/11/08 03:09:30 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_indextoname.c,v 2.3 2000/04/17 22:38:05 dab Exp | |
| 29 | */ | |
| 30 | ||
| f475de6c A |
31 | #include "libinfo_common.h" |
| 32 | ||
| 3b7c7bd7 A |
33 | #include <sys/types.h> |
| 34 | #include <sys/socket.h> | |
| 35 | #include <net/if_dl.h> | |
| 36 | #include <net/if.h> | |
| 37 | #include <ifaddrs.h> | |
| 38 | #include <stdlib.h> | |
| 39 | #include <string.h> | |
| 40 | #include <errno.h> | |
| 41 | ||
| 42 | /* | |
| 43 | * From RFC 2533: | |
| 44 | * | |
| 45 | * The second function maps an interface index into its corresponding | |
| 46 | * name. | |
| 47 | * | |
| 48 | * #include <net/if.h> | |
| 49 | * | |
| 50 | * char *if_indextoname(unsigned int ifindex, char *ifname); | |
| 51 | * | |
| 52 | * The ifname argument must point to a buffer of at least IF_NAMESIZE | |
| 53 | * bytes into which the interface name corresponding to the specified | |
| 54 | * index is returned. (IF_NAMESIZE is also defined in <net/if.h> and | |
| 55 | * its value includes a terminating null byte at the end of the | |
| 56 | * interface name.) This pointer is also the return value of the | |
| 57 | * function. If there is no interface corresponding to the specified | |
| 58 | * index, NULL is returned, and errno is set to ENXIO, if there was a | |
| 59 | * system error (such as running out of memory), if_indextoname returns | |
| 60 | * NULL and errno would be set to the proper value (e.g., ENOMEM). | |
| 61 | */ | |
| 62 | ||
| f475de6c | 63 | LIBINFO_EXPORT |
| 3b7c7bd7 A |
64 | char * |
| 65 | if_indextoname(unsigned int ifindex, char *ifname) | |
| 66 | { | |
| 67 | struct ifaddrs *ifaddrs, *ifa; | |
| 68 | int error = 0; | |
| 69 | ||
| 70 | if (getifaddrs(&ifaddrs) < 0) | |
| 71 | return(NULL); /* getifaddrs properly set errno */ | |
| 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 | ifindex == ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index) | |
| 77 | break; | |
| 78 | } | |
| 79 | ||
| 80 | if (ifa == NULL) { | |
| 81 | error = ENXIO; | |
| 82 | ifname = NULL; | |
| 83 | } | |
| 84 | else | |
| 85 | strncpy(ifname, ifa->ifa_name, IFNAMSIZ); | |
| 86 | ||
| 87 | freeifaddrs(ifaddrs); | |
| 88 | ||
| 89 | errno = error; | |
| 90 | return(ifname); | |
| 91 | } |