source/registry/reg_dispatcher.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Virtual Windows Registry Layer
   4  *  Copyright (C) Gerald Carter                     2002-2005
   5  *  Copyright (C) Michael Adam                      2006-2008
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * Implementation of registry frontend view functions.
  23  * Functions moved from reg_frontend.c to minimize linker deps.
  24  */
  25
  26 #include "includes.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_REGISTRY
  30
  31 static const struct generic_mapping reg_generic_map =
  32         { REG_KEY_READ, REG_KEY_WRITE, REG_KEY_EXECUTE, REG_KEY_ALL };
  33
  34 /********************************************************************
  35 ********************************************************************/
  36
  37 static WERROR construct_registry_sd(TALLOC_CTX *ctx, SEC_DESC **psd)
  38 {
  39         SEC_ACE ace[3];
  40         SEC_ACCESS mask;
  41         size_t i = 0;
  42         SEC_DESC *sd;
  43         SEC_ACL *acl;
  44         size_t sd_size;
  45
  46         /* basic access for Everyone */
  47
  48         init_sec_access(&mask, REG_KEY_READ);
  49         init_sec_ace(&ace[i++], &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED,
  50                      mask, 0);
  51
  52         /* Full Access 'BUILTIN\Administrators' */
  53
  54         init_sec_access(&mask, REG_KEY_ALL);
  55         init_sec_ace(&ace[i++], &global_sid_Builtin_Administrators,
  56                      SEC_ACE_TYPE_ACCESS_ALLOWED, mask, 0);
  57
  58         /* Full Access 'NT Authority\System' */
  59
  60         init_sec_access(&mask, REG_KEY_ALL );
  61         init_sec_ace(&ace[i++], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED,
  62                      mask, 0);
  63
  64         /* create the security descriptor */
  65
  66         acl = make_sec_acl(ctx, NT4_ACL_REVISION, i, ace);
  67         if (acl == NULL) {
  68                 return WERR_NOMEM;
  69         }
  70
  71         sd = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE,
  72                            &global_sid_Builtin_Administrators,
  73                            &global_sid_System, NULL, acl,
  74                            &sd_size);
  75         if (sd == NULL) {
  76                 return WERR_NOMEM;
  77         }
  78
  79         *psd = sd;
  80         return WERR_OK;
  81 }
  82
  83 /***********************************************************************
  84  High level wrapper function for storing registry subkeys
  85  ***********************************************************************/
  86
  87 bool store_reg_keys( REGISTRY_KEY *key, REGSUBKEY_CTR *subkeys )
  88 {
  89         if (key->ops && key->ops->store_subkeys)
  90                 return key->ops->store_subkeys(key->name, subkeys);
  91
  92         return false;
  93 }
  94
  95 /***********************************************************************
  96  High level wrapper function for storing registry values
  97  ***********************************************************************/
  98
  99 bool store_reg_values( REGISTRY_KEY *key, REGVAL_CTR *val )
 100 {
 101         if (key->ops && key->ops->store_values)
 102                 return key->ops->store_values(key->name, val);
 103
 104         return false;
 105 }
 106
 107 /***********************************************************************
 108  High level wrapper function for enumerating registry subkeys
 109  Initialize the TALLOC_CTX if necessary
 110  ***********************************************************************/
 111
 112 int fetch_reg_keys( REGISTRY_KEY *key, REGSUBKEY_CTR *subkey_ctr )
 113 {
 114         int result = -1;
 115
 116         if (key->ops && key->ops->fetch_subkeys)
 117                 result = key->ops->fetch_subkeys(key->name, subkey_ctr);
 118
 119         return result;
 120 }
 121
 122 /***********************************************************************
 123  High level wrapper function for enumerating registry values
 124  ***********************************************************************/
 125
 126 int fetch_reg_values( REGISTRY_KEY *key, REGVAL_CTR *val )
 127 {
 128         int result = -1;
 129
 130         DEBUG(10, ("fetch_reg_values called for key '%s' (ops %p)\n", key->name,
 131                    (key->ops) ? (void *)key->ops : NULL));
 132
 133         if (key->ops && key->ops->fetch_values)
 134                 result = key->ops->fetch_values(key->name, val);
 135
 136         return result;
 137 }
 138
 139 /***********************************************************************
 140  High level access check for passing the required access mask to the
 141  underlying registry backend
 142  ***********************************************************************/
 143
 144 bool regkey_access_check( REGISTRY_KEY *key, uint32 requested, uint32 *granted,
 145                           const struct nt_user_token *token )
 146 {
 147         SEC_DESC *sec_desc;
 148         NTSTATUS status;
 149         WERROR err;
 150         TALLOC_CTX *mem_ctx;
 151
 152         /* use the default security check if the backend has not defined its
 153          * own */
 154
 155         if (key->ops && key->ops->reg_access_check) {
 156                 return key->ops->reg_access_check(key->name, requested,
 157                                                   granted, token);
 158         }
 159
 160         /*
 161          * The secdesc routines can't yet cope with a NULL talloc ctx sanely.
 162          */
 163
 164         if (!(mem_ctx = talloc_init("regkey_access_check"))) {
 165                 return false;
 166         }
 167
 168         err = regkey_get_secdesc(mem_ctx, key, &sec_desc);
 169
 170         if (!W_ERROR_IS_OK(err)) {
 171                 TALLOC_FREE(mem_ctx);
 172                 return false;
 173         }
 174
 175         se_map_generic( &requested, &reg_generic_map );
 176
 177         if (!se_access_check(sec_desc, token, requested, granted, &status)) {
 178                 TALLOC_FREE(mem_ctx);
 179                 return false;
 180         }
 181
 182         TALLOC_FREE(mem_ctx);
 183         return NT_STATUS_IS_OK(status);
 184 }
 185
 186 WERROR regkey_get_secdesc(TALLOC_CTX *mem_ctx, REGISTRY_KEY *key,
 187                           struct security_descriptor **psecdesc)
 188 {
 189         struct security_descriptor *secdesc;
 190         WERROR werr;
 191
 192         if (key->ops && key->ops->get_secdesc) {
 193                 werr = key->ops->get_secdesc(mem_ctx, key->name, psecdesc);
 194                 if (W_ERROR_IS_OK(werr)) {
 195                         return WERR_OK;
 196                 }
 197         }
 198
 199         werr = construct_registry_sd(mem_ctx, &secdesc);
 200         if (!W_ERROR_IS_OK(werr)) {
 201                 return werr;
 202         }
 203
 204         *psecdesc = secdesc;
 205         return WERR_OK;
 206 }
 207
 208 WERROR regkey_set_secdesc(REGISTRY_KEY *key,
 209                           struct security_descriptor *psecdesc)
 210 {
 211         if (key->ops && key->ops->set_secdesc) {
 212                 return key->ops->set_secdesc(key->name, psecdesc);
 213         }
 214
 215         return WERR_ACCESS_DENIED;
 216 }
 217
 218 /**
 219  * Check whether the in-memory version of the subkyes of a
 220  * registry key needs update from disk.
 221  */
 222 bool reg_subkeys_need_update(REGISTRY_KEY *key, REGSUBKEY_CTR *subkeys)
 223 {
 224         if (key->ops && key->ops->subkeys_need_update)
 225         {
 226                 return key->ops->subkeys_need_update(subkeys);
 227         }
 228
 229         return false;
 230 }
 231
 232 /**
 233  * Check whether the in-memory version of the values of a
 234  * registry key needs update from disk.
 235  */
 236 bool reg_values_need_update(REGISTRY_KEY *key, REGVAL_CTR *values)
 237 {
 238         if (key->ops && key->ops->values_need_update)
 239         {
 240                 return key->ops->values_need_update(values);
 241         }
 242
 243         return false;
 244 }
 245