[31f2551] | 1 | /* $KAME: if_indextoname.c,v 1.7 2000/11/08 03:09:30 itojun Exp $ */ |
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| 2 | |
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| 3 | /*- |
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| 4 | * Copyright (c) 1997, 2000 |
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| 5 | * Berkeley Software Design, Inc. All rights reserved. |
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| 6 | * |
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| 7 | * Redistribution and use in source and binary forms, with or without |
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| 8 | * modification, are permitted provided that the following conditions |
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| 9 | * are met: |
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| 10 | * 1. Redistributions of source code must retain the above copyright |
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| 11 | * notice, this list of conditions and the following disclaimer. |
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| 12 | * |
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| 13 | * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND |
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| 14 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 15 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 16 | * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE |
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| 17 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 18 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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| 19 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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| 20 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 21 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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| 22 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 23 | * SUCH DAMAGE. |
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| 24 | * |
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| 25 | * BSDI Id: if_indextoname.c,v 2.3 2000/04/17 22:38:05 dab Exp |
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| 26 | */ |
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| 27 | |
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| 28 | #include <rtems/bsd/sys/cdefs.h> |
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| 29 | |
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| 30 | #include <sys/types.h> |
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| 31 | #include <sys/socket.h> |
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| 32 | #include <net/if_dl.h> |
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| 33 | #include <net/if.h> |
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| 34 | #include <ifaddrs.h> |
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| 35 | #include <stdlib.h> |
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| 36 | #include <string.h> |
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| 37 | #include <errno.h> |
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| 38 | |
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| 39 | /* |
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| 40 | * From RFC 2533: |
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| 41 | * |
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| 42 | * The second function maps an interface index into its corresponding |
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| 43 | * name. |
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| 44 | * |
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| 45 | * #include <net/if.h> |
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| 46 | * |
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| 47 | * char *if_indextoname(unsigned int ifindex, char *ifname); |
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| 48 | * |
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| 49 | * The ifname argument must point to a buffer of at least IF_NAMESIZE |
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| 50 | * bytes into which the interface name corresponding to the specified |
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| 51 | * index is returned. (IF_NAMESIZE is also defined in <net/if.h> and |
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| 52 | * its value includes a terminating null byte at the end of the |
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| 53 | * interface name.) This pointer is also the return value of the |
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| 54 | * function. If there is no interface corresponding to the specified |
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| 55 | * index, NULL is returned, and errno is set to ENXIO, if there was a |
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| 56 | * system error (such as running out of memory), if_indextoname returns |
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| 57 | * NULL and errno would be set to the proper value (e.g., ENOMEM). |
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| 58 | */ |
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| 59 | |
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| 60 | char * |
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| 61 | if_indextoname(unsigned int ifindex, char *ifname) |
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| 62 | { |
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| 63 | struct ifaddrs *ifaddrs, *ifa; |
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| 64 | int error = 0; |
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| 65 | |
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| 66 | if (getifaddrs(&ifaddrs) < 0) |
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| 67 | return(NULL); /* getifaddrs properly set errno */ |
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| 68 | |
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| 69 | for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { |
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| 70 | if (ifa->ifa_addr && |
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| 71 | ifa->ifa_addr->sa_family == AF_LINK && |
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| 72 | ifindex == ((struct sockaddr_dl*)ifa->ifa_addr)->sdl_index) |
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| 73 | break; |
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| 74 | } |
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| 75 | |
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| 76 | if (ifa == NULL) { |
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| 77 | error = ENXIO; |
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| 78 | ifname = NULL; |
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| 79 | } |
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| 80 | else |
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| 81 | strncpy(ifname, ifa->ifa_name, IFNAMSIZ); |
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| 82 | |
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| 83 | freeifaddrs(ifaddrs); |
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| 84 | |
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| 85 | errno = error; |
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| 86 | return(ifname); |
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| 87 | } |
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