crypto/external/bsd/heimdal/dist/lib/roken/getnameinfo_verified.c

   1 /*      $NetBSD: getnameinfo_verified.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $       */
   2
   3 /*
   4  * Copyright (c) 1999 - 2002 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * 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  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #include <krb5/roken.h>
  39
  40 /*
  41  * Try to obtain a verified name for the address in `sa, salen' (much
  42  * similar to getnameinfo).
  43  * Verified in this context means that forwards and backwards lookups
  44  * in DNS are consistent.  If that fails, return an error if the
  45  * NI_NAMEREQD flag is set or return the numeric address as a string.
  46  */
  47
  48 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
  49 getnameinfo_verified(const struct sockaddr *sa, socklen_t salen,
  50                      char *host, size_t hostlen,
  51                      char *serv, size_t servlen,
  52                      int flags)
  53 {
  54     int ret;
  55     struct addrinfo *ai, *a;
  56     char servbuf[NI_MAXSERV];
  57     struct addrinfo hints;
  58     void *saaddr;
  59     size_t sasize;
  60
  61     if (host == NULL)
  62         return EAI_NONAME;
  63
  64     if (serv == NULL) {
  65         serv = servbuf;
  66         servlen = sizeof(servbuf);
  67     }
  68
  69     ret = getnameinfo (sa, salen, host, hostlen, serv, servlen,
  70                        flags | NI_NUMERICSERV);
  71     if (ret)
  72         goto fail;
  73
  74     memset (&hints, 0, sizeof(hints));
  75     hints.ai_socktype = SOCK_STREAM;
  76     ret = getaddrinfo (host, serv, &hints, &ai);
  77     if (ret)
  78         goto fail;
  79
  80     saaddr = socket_get_address(sa);
  81     sasize = socket_addr_size(sa);
  82     for (a = ai; a != NULL; a = a->ai_next) {
  83         if (sasize == socket_addr_size(a->ai_addr) &&
  84             memcmp(saaddr, socket_get_address(a->ai_addr), sasize) == 0) {
  85             freeaddrinfo (ai);
  86             return 0;
  87         }
  88     }
  89     freeaddrinfo (ai);
  90  fail:
  91     if (flags & NI_NAMEREQD)
  92         return EAI_NONAME;
  93     ret = getnameinfo (sa, salen, host, hostlen, serv, servlen,
  94                        flags | NI_NUMERICSERV | NI_NUMERICHOST);
  95     return ret;
  96 }