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 #ifdef HAVE_SYS_UUID_H
  29 #include <sys/uuid.h>
  30 #endif
  31
  32 static DNS_ERROR LabelList( TALLOC_CTX *mem_ctx,
  33                             const char *name,
  34                             struct dns_domain_label **presult )
  35 {
  36         struct dns_domain_label *result;
  37         const char *dot;
  38
  39         for (dot = name; *dot != '\0'; dot += 1) {
  40                 char c = *dot;
  41
  42                 if (c == '.')
  43                         break;
  44
  45                 if (c == '-') continue;
  46                 if ((c >= 'a') && (c <= 'z')) continue;
  47                 if ((c >= 'A') && (c <= 'Z')) continue;
  48                 if ((c >= '0') && (c <= '9')) continue;
  49
  50                 return ERROR_DNS_INVALID_NAME;
  51         }
  52
  53         if ((dot - name) > 63) {
  54                 /*
  55                  * DNS labels can only be 63 chars long
  56                  */
  57                 return ERROR_DNS_INVALID_NAME;
  58         }
  59
  60         if (!(result = talloc_zero(mem_ctx, struct dns_domain_label))) {
  61                 return ERROR_DNS_NO_MEMORY;
  62         }
  63
  64         if (*dot == '\0') {
  65                 /*
  66                  * No dot around, so this is the last component
  67                  */
  68
  69                 if (!(result->label = talloc_strdup(result, name))) {
  70                         TALLOC_FREE(result);
  71                         return ERROR_DNS_NO_MEMORY;
  72                 }
  73                 result->len = strlen(result->label);
  74                 *presult = result;
  75                 return ERROR_DNS_SUCCESS;
  76         }
  77
  78         if (dot[1] == '.') {
  79                 /*
  80                  * Two dots in a row, reject
  81                  */
  82
  83                 TALLOC_FREE(result);
  84                 return ERROR_DNS_INVALID_NAME;
  85         }
  86
  87         if (dot[1] != '\0') {
  88                 /*
  89                  * Something follows, get the rest
  90                  */
  91
  92                 DNS_ERROR err = LabelList(result, dot+1, &result->next);
  93
  94                 if (!ERR_DNS_IS_OK(err)) {
  95                         TALLOC_FREE(result);
  96                         return err;
  97                 }
  98         }
  99
 100         result->len = (dot - name);
 101
 102         if (!(result->label = talloc_strndup(result, name, result->len))) {
 103                 TALLOC_FREE(result);
 104                 return ERROR_DNS_NO_MEMORY;
 105         }
 106
 107         *presult = result;
 108         return ERROR_DNS_SUCCESS;
 109 }
 110
 111 DNS_ERROR dns_domain_name_from_string( TALLOC_CTX *mem_ctx,
 112                                        const char *pszDomainName,
 113                                        struct dns_domain_name **presult )
 114 {
 115         struct dns_domain_name *result;
 116         DNS_ERROR err;
 117
 118         if (!(result = talloc(mem_ctx, struct dns_domain_name))) {
 119                 return ERROR_DNS_NO_MEMORY;
 120         }
 121
 122         err = LabelList( result, pszDomainName, &result->pLabelList );
 123         if (!ERR_DNS_IS_OK(err)) {
 124                 TALLOC_FREE(result);
 125                 return err;
 126         }
 127
 128         *presult = result;
 129         return ERROR_DNS_SUCCESS;
 130 }
 131
 132 /*********************************************************************
 133 *********************************************************************/
 134
 135 char *dns_generate_keyname( TALLOC_CTX *mem_ctx )
 136 {
 137         char *result = NULL;
 138 #if defined(WITH_DNS_UPDATES)
 139
 140         uuid_t uuid;
 141
 142         /*
 143          * uuid_unparse gives 36 bytes plus '\0'
 144          */
 145         if (!(result = talloc_array(mem_ctx, char, 37))) {
 146                 return NULL;
 147         }
 148
 149         uuid_generate( uuid );
 150         uuid_unparse( uuid, result );
 151
 152 #endif
 153
 154         return result;
 155 }