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 "dns.h"
  26 #include <ctype.h>
  27
  28 static DNS_ERROR LabelList( TALLOC_CTX *mem_ctx,
  29                             const char *name,
  30                             struct dns_domain_label **presult )
  31 {
  32         struct dns_domain_label *result;
  33         const char *dot;
  34
  35         for (dot = name; *dot != '\0'; dot += 1) {
  36                 char c = *dot;
  37
  38                 if (c == '.')
  39                         break;
  40
  41                 if (c == '-') continue;
  42                 if ((c >= 'a') && (c <= 'z')) continue;
  43                 if ((c >= 'A') && (c <= 'Z')) continue;
  44                 if ((c >= '0') && (c <= '9')) continue;
  45
  46                 return ERROR_DNS_INVALID_NAME;
  47         }
  48
  49         if ((dot - name) > 63) {
  50                 /*
  51                  * DNS labels can only be 63 chars long
  52                  */
  53                 return ERROR_DNS_INVALID_NAME;
  54         }
  55
  56         if (!(result = TALLOC_ZERO_P(mem_ctx, struct dns_domain_label))) {
  57                 return ERROR_DNS_NO_MEMORY;
  58         }
  59
  60         if (*dot == '\0') {
  61                 /*
  62                  * No dot around, so this is the last component
  63                  */
  64
  65                 if (!(result->label = talloc_strdup(result, name))) {
  66                         TALLOC_FREE(result);
  67                         return ERROR_DNS_NO_MEMORY;
  68                 }
  69                 result->len = strlen(result->label);
  70                 *presult = result;
  71                 return ERROR_DNS_SUCCESS;
  72         }
  73
  74         if (dot[1] == '.') {
  75                 /*
  76                  * Two dots in a row, reject
  77                  */
  78
  79                 TALLOC_FREE(result);
  80                 return ERROR_DNS_INVALID_NAME;
  81         }
  82
  83         if (dot[1] != '\0') {
  84                 /*
  85                  * Something follows, get the rest
  86                  */
  87
  88                 DNS_ERROR err = LabelList(result, dot+1, &result->next);
  89
  90                 if (!ERR_DNS_IS_OK(err)) {
  91                         TALLOC_FREE(result);
  92                         return err;
  93                 }
  94         }
  95
  96         result->len = (dot - name);
  97
  98         if (!(result->label = talloc_strndup(result, name, result->len))) {
  99                 TALLOC_FREE(result);
 100                 return ERROR_DNS_NO_MEMORY;
 101         }
 102
 103         *presult = result;
 104         return ERROR_DNS_SUCCESS;
 105 }
 106
 107 DNS_ERROR dns_domain_name_from_string( TALLOC_CTX *mem_ctx,
 108                                        const char *pszDomainName,
 109                                        struct dns_domain_name **presult )
 110 {
 111         struct dns_domain_name *result;
 112         DNS_ERROR err;
 113
 114         if (!(result = talloc(mem_ctx, struct dns_domain_name))) {
 115                 return ERROR_DNS_NO_MEMORY;
 116         }
 117
 118         err = LabelList( result, pszDomainName, &result->pLabelList );
 119         if (!ERR_DNS_IS_OK(err)) {
 120                 TALLOC_FREE(result);
 121                 return err;
 122         }
 123
 124         *presult = result;
 125         return ERROR_DNS_SUCCESS;
 126 }
 127
 128 /*********************************************************************
 129 *********************************************************************/
 130
 131 char *dns_generate_keyname( TALLOC_CTX *mem_ctx )
 132 {
 133         char *result = NULL;
 134 #if defined(WITH_DNS_UPDATES)
 135
 136         uuid_t uuid;
 137
 138         /*
 139          * uuid_unparse gives 36 bytes plus '\0'
 140          */
 141         if (!(result = TALLOC_ARRAY(mem_ctx, char, 37))) {
 142                 return NULL;
 143         }
 144
 145         uuid_generate( uuid );
 146         uuid_unparse( uuid, result );
 147
 148 #endif
 149
 150         return result;
 151 }