crypto/external/bsd/heimdal/dist/lib/krb5/expand_hostname.c

   1 /*      $NetBSD: expand_hostname.c,v 1.1.1.1 2011/04/13 18:15:33 elric Exp $    */
   2
   3 /*
   4  * Copyright (c) 1999 - 2001 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 "krb5_locl.h"
  37
  38 static krb5_error_code
  39 copy_hostname(krb5_context context,
  40               const char *orig_hostname,
  41               char **new_hostname)
  42 {
  43     *new_hostname = strdup (orig_hostname);
  44     if (*new_hostname == NULL) {
  45         krb5_set_error_message(context, ENOMEM,
  46                                N_("malloc: out of memory", ""));
  47         return ENOMEM;
  48     }
  49     strlwr (*new_hostname);
  50     return 0;
  51 }
  52
  53 /**
  54  * krb5_expand_hostname() tries to make orig_hostname into a more
  55  * canonical one in the newly allocated space returned in
  56  * new_hostname.
  57
  58  * @param context a Keberos context
  59  * @param orig_hostname hostname to canonicalise.
  60  * @param new_hostname output hostname, caller must free hostname with
  61  *        krb5_xfree().
  62  *
  63  * @return Return an error code or 0, see krb5_get_error_message().
  64  *
  65  * @ingroup krb5_support
  66  */
  67
  68 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  69 krb5_expand_hostname (krb5_context context,
  70                       const char *orig_hostname,
  71                       char **new_hostname)
  72 {
  73     struct addrinfo *ai, *a, hints;
  74     int error;
  75
  76     if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
  77         return copy_hostname (context, orig_hostname, new_hostname);
  78
  79     memset (&hints, 0, sizeof(hints));
  80     hints.ai_flags = AI_CANONNAME;
  81
  82     error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
  83     if (error)
  84         return copy_hostname (context, orig_hostname, new_hostname);
  85     for (a = ai; a != NULL; a = a->ai_next) {
  86         if (a->ai_canonname != NULL) {
  87             *new_hostname = strdup (a->ai_canonname);
  88             freeaddrinfo (ai);
  89             if (*new_hostname == NULL) {
  90                 krb5_set_error_message(context, ENOMEM,
  91                                        N_("malloc: out of memory", ""));
  92                 return ENOMEM;
  93             } else {
  94                 return 0;
  95             }
  96         }
  97     }
  98     freeaddrinfo (ai);
  99     return copy_hostname (context, orig_hostname, new_hostname);
 100 }
 101
 102 /*
 103  * handle the case of the hostname being unresolvable and thus identical
 104  */
 105
 106 static krb5_error_code
 107 vanilla_hostname (krb5_context context,
 108                   const char *orig_hostname,
 109                   char **new_hostname,
 110                   char ***realms)
 111 {
 112     krb5_error_code ret;
 113
 114     ret = copy_hostname (context, orig_hostname, new_hostname);
 115     if (ret)
 116         return ret;
 117     strlwr (*new_hostname);
 118
 119     ret = krb5_get_host_realm (context, *new_hostname, realms);
 120     if (ret) {
 121         free (*new_hostname);
 122         return ret;
 123     }
 124     return 0;
 125 }
 126
 127 /**
 128  * krb5_expand_hostname_realms() expands orig_hostname to a name we
 129  * believe to be a hostname in newly allocated space in new_hostname
 130  * and return the realms new_hostname is believed to belong to in
 131  * realms.
 132  *
 133  * @param context a Keberos context
 134  * @param orig_hostname hostname to canonicalise.
 135  * @param new_hostname output hostname, caller must free hostname with
 136  *        krb5_xfree().
 137  * @param realms output possible realms, is an array that is terminated
 138  *        with NULL. Caller must free with krb5_free_host_realm().
 139  *
 140  * @return Return an error code or 0, see krb5_get_error_message().
 141  *
 142  * @ingroup krb5_support
 143  */
 144
 145 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 146 krb5_expand_hostname_realms (krb5_context context,
 147                              const char *orig_hostname,
 148                              char **new_hostname,
 149                              char ***realms)
 150 {
 151     struct addrinfo *ai, *a, hints;
 152     int error;
 153     krb5_error_code ret = 0;
 154
 155     if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
 156         return vanilla_hostname (context, orig_hostname, new_hostname,
 157                                  realms);
 158
 159     memset (&hints, 0, sizeof(hints));
 160     hints.ai_flags = AI_CANONNAME;
 161
 162     error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
 163     if (error)
 164         return vanilla_hostname (context, orig_hostname, new_hostname,
 165                                  realms);
 166
 167     for (a = ai; a != NULL; a = a->ai_next) {
 168         if (a->ai_canonname != NULL) {
 169             ret = copy_hostname (context, a->ai_canonname, new_hostname);
 170             if (ret) {
 171                 freeaddrinfo (ai);
 172                 return ret;
 173             }
 174             strlwr (*new_hostname);
 175             ret = krb5_get_host_realm (context, *new_hostname, realms);
 176             if (ret == 0) {
 177                 freeaddrinfo (ai);
 178                 return 0;
 179             }
 180             free (*new_hostname);
 181         }
 182     }
 183     freeaddrinfo(ai);
 184     return vanilla_hostname (context, orig_hostname, new_hostname, realms);
 185 }