lib/addns/dnsutils.c

   1 /*
   2   Linux DNS client library implementation
   3
   4   Copyright (C) 2006 Krishna Ganugapati <krishnag@centeris.com>
   5   Copyright (C) 2006 Gerald Carter <jerry@samba.org>
   6
   7      ** NOTE! The following LGPL license applies to the libaddns
   8      ** library. This does NOT imply that all of Samba is released
   9      ** under the LGPL
  10
  11   This library is free software; you can redistribute it and/or
  12   modify it under the terms of the GNU Lesser General Public
  13   License as published by the Free Software Foundation; either
  14   version 2.1 of the License, or (at your option) any later version.
  15
  16   This library is distributed in the hope that it will be useful,
  17   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19   Lesser General Public License for more details.
  20
  21   You should have received a copy of the GNU Lesser General Public
  22   License along with this library; if not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "librpc/ndr/libndr.h"
  27 #include "librpc/gen_ndr/ndr_misc.h"
  28
  29 #include "dns.h"
  30 #include <ctype.h>
  31
  32
  33 static DNS_ERROR LabelList( TALLOC_CTX *mem_ctx,
  34                             const char *name,
  35                             struct dns_domain_label **presult )
  36 {
  37         struct dns_domain_label *result;
  38         const char *dot;
  39
  40         for (dot = name; *dot != '\0'; dot += 1) {
  41                 char c = *dot;
  42
  43                 if (c == '.')
  44                         break;
  45
  46                 if (c == '-') continue;
  47                 if ((c >= 'a') && (c <= 'z')) continue;
  48                 if ((c >= 'A') && (c <= 'Z')) continue;
  49                 if ((c >= '0') && (c <= '9')) continue;
  50
  51                 return ERROR_DNS_INVALID_NAME;
  52         }
  53
  54         if ((dot - name) > 63) {
  55                 /*
  56                  * DNS labels can only be 63 chars long
  57                  */
  58                 return ERROR_DNS_INVALID_NAME;
  59         }
  60
  61         if (!(result = talloc_zero(mem_ctx, struct dns_domain_label))) {
  62                 return ERROR_DNS_NO_MEMORY;
  63         }
  64
  65         if (*dot == '\0') {
  66                 /*
  67                  * No dot around, so this is the last component
  68                  */
  69
  70                 if (!(result->label = talloc_strdup(result, name))) {
  71                         TALLOC_FREE(result);
  72                         return ERROR_DNS_NO_MEMORY;
  73                 }
  74                 result->len = strlen(result->label);
  75                 *presult = result;
  76                 return ERROR_DNS_SUCCESS;
  77         }
  78
  79         if (dot[1] == '.') {
  80                 /*
  81                  * Two dots in a row, reject
  82                  */
  83
  84                 TALLOC_FREE(result);
  85                 return ERROR_DNS_INVALID_NAME;
  86         }
  87
  88         if (dot[1] != '\0') {
  89                 /*
  90                  * Something follows, get the rest
  91                  */
  92
  93                 DNS_ERROR err = LabelList(result, dot+1, &result->next);
  94
  95                 if (!ERR_DNS_IS_OK(err)) {
  96                         TALLOC_FREE(result);
  97                         return err;
  98                 }
  99         }
 100
 101         result->len = (dot - name);
 102
 103         if (!(result->label = talloc_strndup(result, name, result->len))) {
 104                 TALLOC_FREE(result);
 105                 return ERROR_DNS_NO_MEMORY;
 106         }
 107
 108         *presult = result;
 109         return ERROR_DNS_SUCCESS;
 110 }
 111
 112 DNS_ERROR dns_domain_name_from_string( TALLOC_CTX *mem_ctx,
 113                                        const char *pszDomainName,
 114                                        struct dns_domain_name **presult )
 115 {
 116         struct dns_domain_name *result;
 117         DNS_ERROR err;
 118
 119         if (!(result = talloc(mem_ctx, struct dns_domain_name))) {
 120                 return ERROR_DNS_NO_MEMORY;
 121         }
 122
 123         err = LabelList( result, pszDomainName, &result->pLabelList );
 124         if (!ERR_DNS_IS_OK(err)) {
 125                 TALLOC_FREE(result);
 126                 return err;
 127         }
 128
 129         *presult = result;
 130         return ERROR_DNS_SUCCESS;
 131 }
 132
 133 /*********************************************************************
 134 *********************************************************************/
 135
 136 char *dns_generate_keyname( TALLOC_CTX *mem_ctx )
 137 {
 138         char *result = NULL;
 139 #if defined(WITH_DNS_UPDATES)
 140
 141         struct GUID guid;
 142
 143         guid = GUID_random();
 144         result = GUID_string(mem_ctx, &guid);
 145
 146 #endif
 147
 148         return result;
 149 }