source3/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 #include "registry.h"
  28 #include "reg_dispatcher.h"
  29
  30 #undef DBGC_CLASS
  31 #define DBGC_CLASS DBGC_REGISTRY
  32
  33 static const struct generic_mapping reg_generic_map =
  34         { REG_KEY_READ, REG_KEY_WRITE, REG_KEY_EXECUTE, REG_KEY_ALL };
  35
  36 /********************************************************************
  37 ********************************************************************/
  38
  39 static WERROR construct_registry_sd(TALLOC_CTX *ctx, struct security_descriptor **psd)
  40 {
  41         struct security_ace ace[3];
  42         size_t i = 0;
  43         struct security_descriptor *sd;
  44         struct security_acl *theacl;
  45         size_t sd_size;
  46
  47         /* basic access for Everyone */
  48
  49         init_sec_ace(&ace[i++], &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED,
  50                      REG_KEY_READ, 0);
  51
  52         /* Full Access 'BUILTIN\Administrators' */
  53
  54         init_sec_ace(&ace[i++], &global_sid_Builtin_Administrators,
  55                      SEC_ACE_TYPE_ACCESS_ALLOWED, REG_KEY_ALL, 0);
  56
  57         /* Full Access 'NT Authority\System' */
  58
  59         init_sec_ace(&ace[i++], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED,
  60                      REG_KEY_ALL, 0);
  61
  62         /* create the security descriptor */
  63
  64         theacl = make_sec_acl(ctx, NT4_ACL_REVISION, i, ace);
  65         if (theacl == NULL) {
  66                 return WERR_NOMEM;
  67         }
  68
  69         sd = make_sec_desc(ctx, SD_REVISION, SEC_DESC_SELF_RELATIVE,
  70                            &global_sid_Builtin_Administrators,
  71                            &global_sid_System, NULL, theacl,
  72                            &sd_size);
  73         if (sd == NULL) {
  74                 return WERR_NOMEM;
  75         }
  76
  77         *psd = sd;
  78         return WERR_OK;
  79 }
  80
  81 /***********************************************************************
  82  High level wrapper function for storing registry subkeys
  83  ***********************************************************************/
  84
  85 bool store_reg_keys(struct registry_key_handle *key,
  86                     struct regsubkey_ctr *subkeys)
  87 {
  88         if (key->ops && key->ops->store_subkeys)
  89                 return key->ops->store_subkeys(key->name, subkeys);
  90
  91         return false;
  92 }
  93
  94 /***********************************************************************
  95  High level wrapper function for storing registry values
  96  ***********************************************************************/
  97
  98 bool store_reg_values(struct registry_key_handle *key, struct regval_ctr *val)
  99 {
 100         if (key->ops && key->ops->store_values)
 101                 return key->ops->store_values(key->name, val);
 102
 103         return false;
 104 }
 105
 106 WERROR create_reg_subkey(struct registry_key_handle *key, const char *subkey)
 107 {
 108         if (key->ops && key->ops->create_subkey) {
 109                 return key->ops->create_subkey(key->name, subkey);
 110         }
 111
 112         return WERR_NOT_SUPPORTED;
 113 }
 114
 115 WERROR delete_reg_subkey(struct registry_key_handle *key, const char *subkey)
 116 {
 117         if (key->ops && key->ops->delete_subkey) {
 118                 return key->ops->delete_subkey(key->name, subkey);
 119         }
 120
 121         return WERR_NOT_SUPPORTED;
 122 }
 123
 124 /***********************************************************************
 125  High level wrapper function for enumerating registry subkeys
 126  Initialize the TALLOC_CTX if necessary
 127  ***********************************************************************/
 128
 129 int fetch_reg_keys(struct registry_key_handle *key,
 130                    struct regsubkey_ctr *subkey_ctr)
 131 {
 132         int result = -1;
 133
 134         if (key->ops && key->ops->fetch_subkeys)
 135                 result = key->ops->fetch_subkeys(key->name, subkey_ctr);
 136
 137         return result;
 138 }
 139
 140 /***********************************************************************
 141  High level wrapper function for enumerating registry values
 142  ***********************************************************************/
 143
 144 int fetch_reg_values(struct registry_key_handle *key, struct regval_ctr *val)
 145 {
 146         int result = -1;
 147
 148         DEBUG(10, ("fetch_reg_values called for key '%s' (ops %p)\n", key->name,
 149                    (key->ops) ? (void *)key->ops : NULL));
 150
 151         if (key->ops && key->ops->fetch_values)
 152                 result = key->ops->fetch_values(key->name, val);
 153
 154         return result;
 155 }
 156
 157 /***********************************************************************
 158  High level access check for passing the required access mask to the
 159  underlying registry backend
 160  ***********************************************************************/
 161
 162 bool regkey_access_check(struct registry_key_handle *key, uint32 requested,
 163                          uint32 *granted,
 164                          const struct nt_user_token *token )
 165 {
 166         struct security_descriptor *sec_desc;
 167         NTSTATUS status;
 168         WERROR err;
 169
 170         /* root free-pass, like we have on all other pipes like samr, lsa, etc. */
 171         if (geteuid() == sec_initial_uid()) {
 172                 *granted = REG_KEY_ALL;
 173                 return true;
 174         }
 175
 176         /* use the default security check if the backend has not defined its
 177          * own */
 178
 179         if (key->ops && key->ops->reg_access_check) {
 180                 return key->ops->reg_access_check(key->name, requested,
 181                                                   granted, token);
 182         }
 183
 184         err = regkey_get_secdesc(talloc_tos(), key, &sec_desc);
 185
 186         if (!W_ERROR_IS_OK(err)) {
 187                 return false;
 188         }
 189
 190         se_map_generic( &requested, &reg_generic_map );
 191
 192         status =se_access_check(sec_desc, token, requested, granted);
 193         TALLOC_FREE(sec_desc);
 194         if (!NT_STATUS_IS_OK(status)) {
 195                 return false;
 196         }
 197
 198         return NT_STATUS_IS_OK(status);
 199 }
 200
 201 WERROR regkey_get_secdesc(TALLOC_CTX *mem_ctx, struct registry_key_handle *key,
 202                           struct security_descriptor **psecdesc)
 203 {
 204         struct security_descriptor *secdesc;
 205         WERROR werr;
 206
 207         if (key->ops && key->ops->get_secdesc) {
 208                 werr = key->ops->get_secdesc(mem_ctx, key->name, psecdesc);
 209                 if (W_ERROR_IS_OK(werr)) {
 210                         return WERR_OK;
 211                 }
 212         }
 213
 214         werr = construct_registry_sd(mem_ctx, &secdesc);
 215         if (!W_ERROR_IS_OK(werr)) {
 216                 return werr;
 217         }
 218
 219         *psecdesc = secdesc;
 220         return WERR_OK;
 221 }
 222
 223 WERROR regkey_set_secdesc(struct registry_key_handle *key,
 224                           struct security_descriptor *psecdesc)
 225 {
 226         if (key->ops && key->ops->set_secdesc) {
 227                 return key->ops->set_secdesc(key->name, psecdesc);
 228         }
 229
 230         return WERR_ACCESS_DENIED;
 231 }
 232
 233 /**
 234  * Check whether the in-memory version of the subkyes of a
 235  * registry key needs update from disk.
 236  */
 237 bool reg_subkeys_need_update(struct registry_key_handle *key,
 238                              struct regsubkey_ctr *subkeys)
 239 {
 240         if (key->ops && key->ops->subkeys_need_update)
 241         {
 242                 return key->ops->subkeys_need_update(subkeys);
 243         }
 244
 245         return false;
 246 }
 247
 248 /**
 249  * Check whether the in-memory version of the values of a
 250  * registry key needs update from disk.
 251  */
 252 bool reg_values_need_update(struct registry_key_handle *key,
 253                             struct regval_ctr *values)
 254 {
 255         if (key->ops && key->ops->values_need_update)
 256         {
 257                 return key->ops->values_need_update(values);
 258         }
 259
 260         return false;
 261 }
 262