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 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         if (ret != LDB_SUCCESS) {
  83                 talloc_free(res);
  84                 return NULL;
  85         }
  86
  87         ctrl = talloc(treq, struct dsdb_control_current_partition);
  88         if (!ctrl) {
  89                 talloc_free(res);
  90                 return NULL;
  91         }
  92         ctrl->version = DSDB_CONTROL_CURRENT_PARTITION_VERSION;
  93         ctrl->dn = schema->base_dn;
  94
  95         ret = ldb_request_add_control(treq,
  96                                       DSDB_CONTROL_CURRENT_PARTITION_OID,
  97                                       false, ctrl);
  98         if (ret != LDB_SUCCESS) {
  99                 talloc_free(res);
 100                 return NULL;
 101         }
 102
 103         ret = ldb_next_request(module, treq);
 104         if (ret != LDB_SUCCESS) {
 105                 talloc_free(res);
 106                 return NULL;
 107         }
 108         ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
 109         if (ret != LDB_SUCCESS) {
 110                 talloc_free(res);
 111                 return NULL;
 112         }
 113         tseqr = talloc_get_type(res->extended->data,
 114                                 struct ldb_seqnum_result);
 115         if (tseqr->seq_num == schema->reload_seq_number) {
 116                 talloc_free(res);
 117                 return schema;
 118         }
 119
 120         schema->reload_seq_number = tseqr->seq_num;
 121         talloc_free(res);
 122
 123         ret = dsdb_module_load_partition_usn(module, schema->base_dn, &current_usn, NULL);
 124         if (ret != LDB_SUCCESS || current_usn == schema->loaded_usn) {
 125                 return schema;
 126         }
 127
 128         ret = dsdb_schema_from_db(module, schema->base_dn, current_usn, &new_schema);
 129         if (ret != LDB_SUCCESS) {
 130                 return schema;
 131         }
 132
 133         if (is_global_schema) {
 134                 dsdb_make_schema_global(ldb, new_schema);
 135         }
 136         return new_schema;
 137 }
 138
 139
 140 /*
 141   Given an LDB module (pointing at the schema DB), and the DN, set the populated schema
 142 */
 143
 144 static int dsdb_schema_from_db(struct ldb_module *module, struct ldb_dn *schema_dn, uint64_t current_usn,
 145                                struct dsdb_schema **schema)
 146 {
 147         struct ldb_context *ldb = ldb_module_get_ctx(module);
 148         TALLOC_CTX *tmp_ctx;
 149         char *error_string;
 150         int ret;
 151         struct ldb_result *schema_res;
 152         struct ldb_result *a_res;
 153         struct ldb_result *c_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                 ldb_oom(ldb);
 165                 return LDB_ERR_OPERATIONS_ERROR;
 166         }
 167
 168         /* we don't want to trace the schema load */
 169         flags = ldb_get_flags(ldb);
 170         ldb_set_flags(ldb, flags & ~LDB_FLG_ENABLE_TRACING);
 171
 172         /*
 173          * setup the prefix mappings and schema info
 174          */
 175         ret = dsdb_module_search_dn(module, tmp_ctx, &schema_res,
 176                                     schema_dn, schema_attrs, 0);
 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, &a_res,
 193                                  schema_dn, LDB_SCOPE_ONELEVEL, NULL,
 194                                  0,
 195                                  "(objectClass=attributeSchema)");
 196         if (ret != LDB_SUCCESS) {
 197                 ldb_asprintf_errstring(ldb,
 198                                        "dsdb_schema: failed to search attributeSchema objects: %s",
 199                                        ldb_errstring(ldb));
 200                 goto failed;
 201         }
 202
 203         /*
 204          * load the objectClass definitions
 205          */
 206         ret = dsdb_module_search(module, tmp_ctx, &c_res,
 207                                  schema_dn, LDB_SCOPE_ONELEVEL, NULL,
 208                                  DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT,
 209                                  "(objectClass=classSchema)");
 210         if (ret != LDB_SUCCESS) {
 211                 ldb_asprintf_errstring(ldb,
 212                                        "dsdb_schema: failed to search classSchema objects: %s",
 213                                        ldb_errstring(ldb));
 214                 goto failed;
 215         }
 216
 217         ret = dsdb_schema_from_ldb_results(tmp_ctx, ldb,
 218                                            lp_iconv_convenience(ldb_get_opaque(ldb, "loadparm")),
 219                                            schema_res, a_res, c_res, schema, &error_string);
 220         if (ret != LDB_SUCCESS) {
 221                 ldb_asprintf_errstring(ldb,
 222                                        "dsdb_schema load failed: %s",
 223                                        error_string);
 224                 goto failed;
 225         }
 226
 227         (*schema)->refresh_fn = dsdb_schema_refresh;
 228         (*schema)->loaded_from_module = module;
 229         (*schema)->loaded_usn = current_usn;
 230
 231         /* dsdb_set_schema() steal schema into the ldb_context */
 232         ret = dsdb_set_schema(ldb, (*schema));
 233
 234         if (ret != LDB_SUCCESS) {
 235                 ldb_debug_set(ldb, LDB_DEBUG_FATAL,
 236                               "schema_load_init: dsdb_set_schema() failed: %d:%s: %s",
 237                               ret, ldb_strerror(ret), ldb_errstring(ldb));
 238                 talloc_free(tmp_ctx);
 239                 return ret;
 240         }
 241
 242         /* Ensure this module won't go away before the callback */
 243         if (talloc_reference(*schema, ldb) == NULL) {
 244                 ldb_oom(ldb);
 245                 ret = LDB_ERR_OPERATIONS_ERROR;
 246         }
 247
 248 failed:
 249         if (flags & LDB_FLG_ENABLE_TRACING) {
 250                 flags = ldb_get_flags(ldb);
 251                 ldb_set_flags(ldb, flags | LDB_FLG_ENABLE_TRACING);
 252         }
 253         talloc_free(tmp_ctx);
 254         return ret;
 255 }
 256
 257
 258 static int schema_load_init(struct ldb_module *module)
 259 {
 260         struct schema_load_private_data *private_data;
 261         struct dsdb_schema *schema;
 262         struct ldb_context *ldb = ldb_module_get_ctx(module);
 263         int ret;
 264         uint64_t current_usn;
 265         struct ldb_dn *schema_dn;
 266
 267         private_data = talloc_zero(module, struct schema_load_private_data);
 268         if (private_data == NULL) {
 269                 ldb_oom(ldb);
 270                 return LDB_ERR_OPERATIONS_ERROR;
 271         }
 272
 273         ldb_module_set_private(module, private_data);
 274
 275         ret = ldb_next_init(module);
 276         if (ret != LDB_SUCCESS) {
 277                 return ret;
 278         }
 279
 280         if (dsdb_get_schema(ldb, NULL)) {
 281                 return LDB_SUCCESS;
 282         }
 283
 284         schema_dn = samdb_schema_dn(ldb);
 285         if (!schema_dn) {
 286                 ldb_reset_err_string(ldb);
 287                 ldb_debug(ldb, LDB_DEBUG_WARNING,
 288                           "schema_load_init: no schema dn present: (skip schema loading)\n");
 289                 return LDB_SUCCESS;
 290         }
 291
 292         ret = dsdb_module_load_partition_usn(module, schema_dn, &current_usn, NULL);
 293         if (ret != LDB_SUCCESS) {
 294                 ldb_asprintf_errstring(ldb,
 295                                        "dsdb_load_partition_usn failed: %s",
 296                                        ldb_errstring(ldb));
 297                 return ret;
 298         }
 299
 300         return dsdb_schema_from_db(module, schema_dn, current_usn, &schema);
 301 }
 302
 303 static int schema_load_start_transaction(struct ldb_module *module)
 304 {
 305         struct schema_load_private_data *private_data =
 306                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 307
 308         private_data->in_transaction = true;
 309
 310         return ldb_next_start_trans(module);
 311 }
 312
 313 static int schema_load_del_transaction(struct ldb_module *module)
 314 {
 315         struct schema_load_private_data *private_data =
 316                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 317
 318         private_data->in_transaction = false;
 319
 320         return ldb_next_del_trans(module);
 321 }
 322
 323 static int schema_load_prepare_commit(struct ldb_module *module)
 324 {
 325         int ret;
 326         struct schema_load_private_data *private_data =
 327                 talloc_get_type(ldb_module_get_private(module), struct schema_load_private_data);
 328
 329         ret = ldb_next_prepare_commit(module);
 330         private_data->in_transaction = false;
 331         return ret;
 332 }
 333
 334 static int schema_load_extended(struct ldb_module *module, struct ldb_request *req)
 335 {
 336         struct ldb_context *ldb;
 337
 338         ldb = ldb_module_get_ctx(module);
 339
 340         if (strcmp(req->op.extended.oid, DSDB_EXTENDED_SCHEMA_UPDATE_NOW_OID) != 0) {
 341                 return ldb_next_request(module, req);
 342         }
 343
 344         /* This is a no-op.  We reload as soon as we can */
 345         return ldb_module_done(req, NULL, NULL, LDB_SUCCESS);
 346 }
 347
 348
 349 _PUBLIC_ const struct ldb_module_ops ldb_schema_load_module_ops = {
 350         .name           = "schema_load",
 351         .init_context   = schema_load_init,
 352         .extended       = schema_load_extended,
 353         .start_transaction = schema_load_start_transaction,
 354         .prepare_commit    = schema_load_prepare_commit,
 355         .del_transaction   = schema_load_del_transaction,
 356 };