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

   1 /*
   2  * Copyright (c) 1999 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   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  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 __RCSID("$Heimdal: expand_hostname.c 22229 2007-12-08 21:40:59Z lha $"
  37         "$NetBSD$");
  38
  39 static krb5_error_code
  40 copy_hostname(krb5_context context,
  41               const char *orig_hostname,
  42               char **new_hostname)
  43 {
  44     *new_hostname = strdup (orig_hostname);
  45     if (*new_hostname == NULL) {
  46         krb5_set_error_string(context, "malloc: out of memory");
  47         return ENOMEM;
  48     }
  49     strlwr (*new_hostname);
  50     return 0;
  51 }
  52
  53 /*
  54  * Try to make `orig_hostname' into a more canonical one in the newly
  55  * allocated space returned in `new_hostname'.
  56  */
  57
  58 krb5_error_code KRB5_LIB_FUNCTION
  59 krb5_expand_hostname (krb5_context context,
  60                       const char *orig_hostname,
  61                       char **new_hostname)
  62 {
  63     struct addrinfo *ai, *a, hints;
  64     int error;
  65
  66     if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
  67         return copy_hostname (context, orig_hostname, new_hostname);
  68
  69     memset (&hints, 0, sizeof(hints));
  70     hints.ai_flags = AI_CANONNAME;
  71
  72     error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
  73     if (error)
  74         return copy_hostname (context, orig_hostname, new_hostname);
  75     for (a = ai; a != NULL; a = a->ai_next) {
  76         if (a->ai_canonname != NULL) {
  77             *new_hostname = strdup (a->ai_canonname);
  78             freeaddrinfo (ai);
  79             if (*new_hostname == NULL) {
  80                 krb5_set_error_string(context, "malloc: out of memory");
  81                 return ENOMEM;
  82             } else {
  83                 return 0;
  84             }
  85         }
  86     }
  87     freeaddrinfo (ai);
  88     return copy_hostname (context, orig_hostname, new_hostname);
  89 }
  90
  91 /*
  92  * handle the case of the hostname being unresolvable and thus identical
  93  */
  94
  95 static krb5_error_code
  96 vanilla_hostname (krb5_context context,
  97                   const char *orig_hostname,
  98                   char **new_hostname,
  99                   char ***realms)
 100 {
 101     krb5_error_code ret;
 102
 103     ret = copy_hostname (context, orig_hostname, new_hostname);
 104     if (ret)
 105         return ret;
 106     strlwr (*new_hostname);
 107
 108     ret = krb5_get_host_realm (context, *new_hostname, realms);
 109     if (ret) {
 110         free (*new_hostname);
 111         return ret;
 112     }
 113     return 0;
 114 }
 115
 116 /*
 117  * expand `hostname' to a name we believe to be a hostname in newly
 118  * allocated space in `host' and return realms in `realms'.
 119  */
 120
 121 krb5_error_code KRB5_LIB_FUNCTION
 122 krb5_expand_hostname_realms (krb5_context context,
 123                              const char *orig_hostname,
 124                              char **new_hostname,
 125                              char ***realms)
 126 {
 127     struct addrinfo *ai, *a, hints;
 128     int error;
 129     krb5_error_code ret = 0;
 130
 131     if ((context->flags & KRB5_CTX_F_DNS_CANONICALIZE_HOSTNAME) == 0)
 132         return vanilla_hostname (context, orig_hostname, new_hostname,
 133                                  realms);
 134
 135     memset (&hints, 0, sizeof(hints));
 136     hints.ai_flags = AI_CANONNAME;
 137
 138     error = getaddrinfo (orig_hostname, NULL, &hints, &ai);
 139     if (error)
 140         return vanilla_hostname (context, orig_hostname, new_hostname,
 141                                  realms);
 142
 143     for (a = ai; a != NULL; a = a->ai_next) {
 144         if (a->ai_canonname != NULL) {
 145             ret = copy_hostname (context, a->ai_canonname, new_hostname);
 146             if (ret) {
 147                 freeaddrinfo (ai);
 148                 return ret;
 149             }
 150             strlwr (*new_hostname);
 151             ret = krb5_get_host_realm (context, *new_hostname, realms);
 152             if (ret == 0) {
 153                 freeaddrinfo (ai);
 154                 return 0;
 155             }
 156             free (*new_hostname);
 157         }
 158     }
 159     freeaddrinfo(ai);
 160     return vanilla_hostname (context, orig_hostname, new_hostname, realms);
 161 }