lookup.subproj/getnameinfo_link.c

   1 /*
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * Copyright (c) 2000 Ben Harris.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the project nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <stdint.h>
  32 #include <stdio.h>
  33 #include <netdb.h>
  34 #include <net/if_types.h>
  35 #include <net/if_dl.h>
  36
  37 static int
  38 hexname(const uint8_t *cp, size_t len, char *host, size_t hostlen)
  39 {
  40         int i, n;
  41         char *outp = host;
  42
  43         *outp = '\0';
  44         for (i = 0; i < len; i++)
  45         {
  46                 n = snprintf(outp, hostlen, "%s%02x", i ? ":" : "", cp[i]);
  47                 if ((n < 0) || (n >= hostlen))
  48                 {
  49                         *host = '\0';
  50                         return EAI_MEMORY;
  51                 }
  52
  53                 outp += n;
  54                 hostlen -= n;
  55         }
  56
  57         return 0;
  58 }
  59
  60 /*
  61  * getnameinfo_link():
  62  * Format a link-layer address into a printable format, paying attention to
  63  * the interface type.
  64  */
  65 __private_extern__ int
  66 getnameinfo_link(const struct sockaddr *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags)
  67 {
  68         const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)(const void *)sa;
  69         int n;
  70
  71         if (serv != NULL && servlen > 0) *serv = '\0';
  72
  73         if ((sdl->sdl_nlen == 0) && (sdl->sdl_alen == 0) && (sdl->sdl_slen == 0))
  74         {
  75                 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index);
  76                 if (n > hostlen)
  77                 {
  78                         *host = '\0';
  79                         return EAI_MEMORY;
  80                 }
  81
  82                 return 0;
  83         }
  84
  85         switch (sdl->sdl_type)
  86         {
  87                         /*
  88                          * The following have zero-length addresses.
  89                          * IFT_ATM      (net/if_atmsubr.c)
  90                          * IFT_FAITH    (net/if_faith.c)
  91                          * IFT_GIF      (net/if_gif.c)
  92                          * IFT_LOOP     (net/if_loop.c)
  93                          * IFT_PPP      (net/if_ppp.c, net/if_spppsubr.c)
  94                          * IFT_SLIP     (net/if_sl.c, net/if_strip.c)
  95                          * IFT_STF      (net/if_stf.c)
  96                          * IFT_L2VLAN   (net/if_vlan.c)
  97                          * IFT_BRIDGE (net/if_bridge.h>
  98                          */
  99                         /*
 100                          * The following use IPv4 addresses as link-layer addresses:
 101                          * IFT_OTHER    (net/if_gre.c)
 102                          * IFT_OTHER    (netinet/ip_ipip.c)
 103                          */
 104                         /* default below is believed correct for all these. */
 105                 case IFT_ARCNET:
 106                 case IFT_ETHER:
 107                 case IFT_FDDI:
 108                 case IFT_HIPPI:
 109                 case IFT_ISO88025:
 110                 default:
 111                         return hexname((uint8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen, host, hostlen);
 112         }
 113
 114         /* NOTREACHED */
 115         return EAI_FAIL;
 116 }