source4/dsdb/samdb/ldb_modules/schema_load.c

   1 /*
   2    Unix SMB/CIFS mplementation.
   3
   4    The module that handles the Schema FSMO Role Owner
   5    checkings, it also loads the dsdb_schema.
   6
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
   8    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009-2010
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 */
  24
  25 #include "includes.h"
  26 #include "ldb_module.h"
  27 #include "dsdb/samdb/samdb.h"
  28 #include "librpc/gen_ndr/ndr_misc.h"
  29 #include "librpc/gen_ndr/ndr_drsuapi.h"
  30 #include "librpc/gen_ndr/ndr_drsblobs.h"
  31 #include "param/param.h"
  32 #include "dsdb/samdb/ldb_modules/util.h"
  33
  34 struct schema_load_private_data {
  35         bool in_transaction;
  36 };
  37
  38 static int dsdb_schema_from_db(struct ldb_module *module, struct ldb_dn *schema_dn, uint64_t current_usn,
  39                                struct dsdb_schema **schema);
  40
  41 static struct dsdb_schema *dsdb_schema_refresh(struct ldb_module *module, struct dsdb_schema *schema, bool is_global_schema)
  42 {
  43         uint64_t current_usn;
  44         int ret;
  45         struct ldb_result *res;
  46         struct ldb_request *treq;
  47         struct ldb_seqnum_request *tseq;
  48         struct ldb_seqnum_result *tseqr;
  49         struct dsdb_control_current_partition *ctrl;
  50         struct ldb_context *ldb = ldb_module_get_ctx(module);
  51         struct dsdb_schema *new_schema;
  52
  53         struct schema_load_private_data *private_data = talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
  54         if (!private_data) {
  55                 /* We can't refresh until the init function has run */
  56                 return schema;
  57         }
  58
  59         /* We don't allow a schema reload during a transaction - nobody else can modify our schema behind our backs */
  60         if (private_data->in_transaction) {
  61                 return schema;
  62         }
  63
  64         res = talloc_zero(schema, struct ldb_result);
  65         if (res == NULL) {
  66                 return NULL;
  67         }
  68         tseq = talloc_zero(res, struct ldb_seqnum_request);
  69         if (tseq == NULL) {
  70                 talloc_free(res);
  71                 return NULL;
  72         }
  73         tseq->type = LDB_SEQ_HIGHEST_SEQ;
  74
  75         ret = ldb_build_extended_req(&treq, ldb_module_get_ctx(module), res,
  76                                      LDB_EXTENDED_SEQUENCE_NUMBER,
  77                                      tseq,
  78                                      NULL,
  79                                      res,
  80                                      ldb_extended_default_callback,
  81                                      NULL);
  82         LDB_REQ_SET_LOCATION(treq);
  83         if (ret != LDB_SUCCESS) {
  84                 talloc_free(res);
  85                 return NULL;
  86         }
  87
  88         ctrl = talloc(treq, struct dsdb_control_current_partition);
  89         if (!ctrl) {
  90                 talloc_free(res);
  91                 return NULL;
  92         }
  93         ctrl->version = DSDB_CONTROL_CURRENT_PARTITION_VERSION;
  94         ctrl->dn = schema->base_dn;
  95
  96         ret = ldb_request_add_control(treq,
  97                                       DSDB_CONTROL_CURRENT_PARTITION_OID,
  98                                       false, ctrl);
  99         if (ret != LDB_SUCCESS) {
 100                 talloc_free(res);
 101                 return NULL;
 102         }
 103
 104         ret = ldb_next_request(module, treq);
 105         if (ret != LDB_SUCCESS) {
 106                 talloc_free(res);
 107                 return NULL;
 108         }
 109         ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
 110         if (ret != LDB_SUCCESS) {
 111                 talloc_free(res);
 112                 return NULL;
 113         }
 114         tseqr = talloc_get_type(res->extended->data,
 115                                 struct ldb_seqnum_result);
 116         if (tseqr->seq_num == schema->reload_seq_number) {
 117                 talloc_free(res);
 118                 return schema;
 119         }
 120
 121         schema->reload_seq_number = tseqr->seq_num;
 122         talloc_free(res);
 123
 124         ret = dsdb_module_load_partition_usn(module, schema->base_dn, &current_usn, NULL, NULL);
 125         if (ret != LDB_SUCCESS || current_usn == schema->loaded_usn) {
 126                 return schema;
 127         }
 128
 129         ret = dsdb_schema_from_db(module, schema->base_dn, current_usn, &new_schema);
 130         if (ret != LDB_SUCCESS) {
 131                 return schema;
 132         }
 133
 134         if (is_global_schema) {
 135                 dsdb_make_schema_global(ldb, new_schema);
 136         }
 137         return new_schema;
 138 }
 139
 140
 141 /*
 142   Given an LDB module (pointing at the schema DB), and the DN, set the populated schema
 143 */
 144
 145 static int dsdb_schema_from_db(struct ldb_module *module, struct ldb_dn *schema_dn, uint64_t current_usn,
 146                                struct dsdb_schema **schema)
 147 {
 148         struct ldb_context *ldb = ldb_module_get_ctx(module);
 149         TALLOC_CTX *tmp_ctx;
 150         char *error_string;
 151         int ret;
 152         struct ldb_result *schema_res;
 153         struct ldb_result *res;
 154         static const char *schema_attrs[] = {
 155                 "prefixMap",
 156                 "schemaInfo",
 157                 "fSMORoleOwner",
 158                 NULL
 159         };
 160         unsigned flags;
 161
 162         tmp_ctx = talloc_new(module);
 163         if (!tmp_ctx) {
 164                 return ldb_oom(ldb);
 165         }
 166
 167         /* we don't want to trace the schema load */
 168         flags = ldb_get_flags(ldb);
 169         ldb_set_flags(ldb, flags & ~LDB_FLG_ENABLE_TRACING);
 170
 171         /*
 172          * setup the prefix mappings and schema info
 173          */
 174         ret = dsdb_module_search_dn(module, tmp_ctx, &schema_res,
 175                                     schema_dn, schema_attrs,
 176                                     DSDB_FLAG_NEXT_MODULE, NULL);
 177         if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 178                 ldb_reset_err_string(ldb);
 179                 ldb_debug(ldb, LDB_DEBUG_WARNING,
 180                           "schema_load_init: no schema head present: (skip schema loading)\n");
 181                 goto failed;
 182         } else if (ret != LDB_SUCCESS) {
 183                 ldb_asprintf_errstring(ldb,
 184                                        "dsdb_schema: failed to search the schema head: %s",
 185                                        ldb_errstring(ldb));
 186                 goto failed;
 187         }
 188
 189         /*
 190          * load the attribute definitions
 191          */
 192         ret = dsdb_module_search(module, tmp_ctx, &res,
 193                                  schema_dn, LDB_SCOPE_ONELEVEL, NULL,
 194                                  DSDB_FLAG_NEXT_MODULE |
 195                                  DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT,
 196                                  NULL,
 197                                  "(|(objectClass=attributeSchema)(objectClass=classSchema))");
 198         if (ret != LDB_SUCCESS) {
 199                 ldb_asprintf_errstring(ldb,
 200                                        "dsdb_schema: failed to search attributeSchema and classSchema objects: %s",
 201                                        ldb_errstring(ldb));
 202                 goto failed;
 203         }
 204
 205         ret = dsdb_schema_from_ldb_results(tmp_ctx, ldb,
 206                                            schema_res, res, schema, &error_string);
 207         if (ret != LDB_SUCCESS) {
 208                 ldb_asprintf_errstring(ldb,
 209                                        "dsdb_schema load failed: %s",
 210                                        error_string);
 211                 goto failed;
 212         }
 213
 214         (*schema)->refresh_in_progress = true;
 215
 216         /* If we have the readOnlySchema opaque, then don't check for
 217          * runtime schema updates, as they are not permitted (we would
 218          * have to update the backend server schema too */
 219         if (!ldb_get_opaque(ldb, "readOnlySchema")) {
 220                 (*schema)->refresh_fn = dsdb_schema_refresh;
 221                 (*schema)->loaded_from_module = module;
 222                 (*schema)->loaded_usn = current_usn;
 223         }
 224
 225         /* "dsdb_set_schema()" steals schema into the ldb_context */
 226         ret = dsdb_set_schema(ldb, (*schema));
 227
 228         (*schema)->refresh_in_progress = false;
 229
 230         if (ret != LDB_SUCCESS) {
 231                 ldb_debug_set(ldb, LDB_DEBUG_FATAL,
 232                               "schema_load_init: dsdb_set_schema() failed: %d:%s: %s",
 233                               ret, ldb_strerror(ret), ldb_errstring(ldb));
 234                 goto failed;
 235         }
 236
 237         /* Ensure this module won't go away before the callback */
 238         if (talloc_reference(*schema, ldb) == NULL) {
 239                 ldb_oom(ldb);
 240                 ret = LDB_ERR_OPERATIONS_ERROR;
 241         }
 242
 243 failed:
 244         if (flags & LDB_FLG_ENABLE_TRACING) {
 245                 flags = ldb_get_flags(ldb);
 246                 ldb_set_flags(ldb, flags | LDB_FLG_ENABLE_TRACING);
 247         }
 248         talloc_free(tmp_ctx);
 249         return ret;
 250 }
 251
 252
 253 static int schema_load_init(struct ldb_module *module)
 254 {
 255         struct schema_load_private_data *private_data;
 256         struct dsdb_schema *schema;
 257         struct ldb_context *ldb = ldb_module_get_ctx(module);
 258         int ret;
 259         uint64_t current_usn;
 260         struct ldb_dn *schema_dn;
 261
 262         private_data = talloc_zero(module, struct schema_load_private_data);
 263         if (private_data == NULL) {
 264                 return ldb_oom(ldb);
 265         }
 266
 267         ldb_module_set_private(module, private_data);
 268
 269         ret = ldb_next_init(module);
 270         if (ret != LDB_SUCCESS) {
 271                 return ret;
 272         }
 273
 274         if (dsdb_get_schema(ldb, NULL)) {
 275                 return LDB_SUCCESS;
 276         }
 277
 278         schema_dn = ldb_get_schema_basedn(ldb);
 279         if (!schema_dn) {
 280                 ldb_reset_err_string(ldb);
 281                 ldb_debug(ldb, LDB_DEBUG_WARNING,
 282                           "schema_load_init: no schema dn present: (skip schema loading)\n");
 283                 return LDB_SUCCESS;
 284         }
 285
 286         ret = dsdb_module_load_partition_usn(module, schema_dn, &current_usn, NULL, NULL);
 287         if (ret != LDB_SUCCESS) {
 288                 /* Ignore the error and just reload the DB more often */
 289                 current_usn = 0;
 290         }
 291
 292         return dsdb_schema_from_db(module, schema_dn, current_usn, &schema);
 293 }
 294
 295 static int schema_load_start_transaction(struct ldb_module *module)
 296 {
 297         struct schema_load_private_data *private_data =
 298                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 299
 300         private_data->in_transaction = true;
 301
 302         return ldb_next_start_trans(module);
 303 }
 304
 305 static int schema_load_end_transaction(struct ldb_module *module)
 306 {
 307         struct schema_load_private_data *private_data =
 308                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 309
 310         private_data->in_transaction = false;
 311
 312         return ldb_next_end_trans(module);
 313 }
 314
 315 static int schema_load_del_transaction(struct ldb_module *module)
 316 {
 317         struct schema_load_private_data *private_data =
 318                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 319
 320         private_data->in_transaction = false;
 321
 322         return ldb_next_del_trans(module);
 323 }
 324
 325 static int schema_load_extended(struct ldb_module *module, struct ldb_request *req)
 326 {
 327         struct ldb_context *ldb;
 328
 329         ldb = ldb_module_get_ctx(module);
 330
 331         if (strcmp(req->op.extended.oid, DSDB_EXTENDED_SCHEMA_UPDATE_NOW_OID) != 0) {
 332                 return ldb_next_request(module, req);
 333         }
 334
 335         /* This is a no-op.  We reload as soon as we can */
 336         return ldb_module_done(req, NULL, NULL, LDB_SUCCESS);
 337 }
 338
 339
 340 static const struct ldb_module_ops ldb_schema_load_module_ops = {
 341         .name           = "schema_load",
 342         .init_context   = schema_load_init,
 343         .extended       = schema_load_extended,
 344         .start_transaction = schema_load_start_transaction,
 345         .end_transaction   = schema_load_end_transaction,
 346         .del_transaction   = schema_load_del_transaction,
 347 };
 348
 349 int ldb_schema_load_module_init(const char *version)
 350 {
 351         LDB_MODULE_CHECK_VERSION(version);
 352         return ldb_register_module(&ldb_schema_load_module_ops);
 353 }