source4/dsdb/samdb/ldb_modules/samba_dsdb.c

   1 /*
   2    Samba4 module loading module
   3
   4    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 /*
  21  *  Name: ldb
  22  *
  23  *  Component: Samba4 module loading module
  24  *
  25  *  Description: Implement a single 'module' in the ldb database,
  26  *  which loads the remaining modules based on 'choice of configuration' attributes
  27  *
  28  *  This is to avoid forcing a reprovision of the ldb databases when we change the internal structure of the code
  29  *
  30  *  Author: Andrew Bartlett
  31  */
  32
  33 #include "includes.h"
  34 #include <ldb.h>
  35 #include <ldb_errors.h>
  36 #include <ldb_module.h>
  37 #include "dsdb/samdb/ldb_modules/util.h"
  38 #include "dsdb/samdb/samdb.h"
  39 #include "librpc/ndr/libndr.h"
  40 #include "auth/credentials/credentials.h"
  41 #include "param/secrets.h"
  42 #include "lib/ldb-samba/ldb_wrap.h"
  43
  44 static int read_at_rootdse_record(struct ldb_context *ldb, struct ldb_module *module, TALLOC_CTX *mem_ctx,
  45                                   struct ldb_message **msg, struct ldb_request *parent)
  46 {
  47         int ret;
  48         static const char *rootdse_attrs[] = { "defaultNamingContext", "configurationNamingContext", "schemaNamingContext", NULL };
  49         struct ldb_result *rootdse_res;
  50         struct ldb_dn *rootdse_dn;
  51         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  52         if (!tmp_ctx) {
  53                 return ldb_oom(ldb);
  54         }
  55
  56         rootdse_dn = ldb_dn_new(tmp_ctx, ldb, "@ROOTDSE");
  57         if (!rootdse_dn) {
  58                 talloc_free(tmp_ctx);
  59                 return ldb_oom(ldb);
  60         }
  61
  62         ret = dsdb_module_search_dn(module, tmp_ctx, &rootdse_res, rootdse_dn,
  63                                     rootdse_attrs, DSDB_FLAG_NEXT_MODULE, parent);
  64         if (ret != LDB_SUCCESS) {
  65                 talloc_free(tmp_ctx);
  66                 return ret;
  67         }
  68
  69         talloc_steal(mem_ctx, rootdse_res->msgs);
  70         *msg = rootdse_res->msgs[0];
  71
  72         talloc_free(tmp_ctx);
  73
  74         return ret;
  75 }
  76
  77 static int prepare_modules_line(struct ldb_context *ldb,
  78                                 TALLOC_CTX *mem_ctx,
  79                                 const struct ldb_message *rootdse_msg,
  80                                 struct ldb_message *msg, const char *backend_attr,
  81                                 const char *backend_mod, const char **backend_mod_list)
  82 {
  83         int ret;
  84         const char **backend_full_list;
  85         const char *backend_dn;
  86         char *mod_list_string;
  87         char *full_string;
  88         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  89         if (!tmp_ctx) {
  90                 return ldb_oom(ldb);
  91         }
  92
  93         if (backend_attr) {
  94                 backend_dn = ldb_msg_find_attr_as_string(rootdse_msg, backend_attr, NULL);
  95                 if (!backend_dn) {
  96                         ldb_asprintf_errstring(ldb,
  97                                                "samba_dsdb_init: "
  98                                                "unable to read %s from %s:%s",
  99                                                backend_attr, ldb_dn_get_linearized(rootdse_msg->dn),
 100                                                ldb_errstring(ldb));
 101                         return LDB_ERR_CONSTRAINT_VIOLATION;
 102                 }
 103         } else {
 104                 backend_dn = "*";
 105         }
 106
 107         if (backend_mod) {
 108                 char **b = str_list_make_single(tmp_ctx, backend_mod);
 109                 backend_full_list = discard_const_p(const char *, b);
 110         } else {
 111                 char **b = str_list_make_empty(tmp_ctx);
 112                 backend_full_list = discard_const_p(const char *, b);
 113         }
 114         if (!backend_full_list) {
 115                 talloc_free(tmp_ctx);
 116                 return ldb_oom(ldb);
 117         }
 118
 119         backend_full_list = str_list_append_const(backend_full_list, backend_mod_list);
 120         if (!backend_full_list) {
 121                 talloc_free(tmp_ctx);
 122                 return ldb_oom(ldb);
 123         }
 124
 125         mod_list_string = str_list_join(tmp_ctx, backend_full_list, ',');
 126
 127         /* str_list_append allocates on NULL */
 128         talloc_free(backend_full_list);
 129
 130         if (!mod_list_string) {
 131                 talloc_free(tmp_ctx);
 132                 return ldb_oom(ldb);
 133         }
 134
 135         full_string = talloc_asprintf(tmp_ctx, "%s:%s", backend_dn, mod_list_string);
 136         ret = ldb_msg_add_steal_string(msg, "modules", full_string);
 137         talloc_free(tmp_ctx);
 138         return ret;
 139 }
 140
 141 static bool check_required_features(struct ldb_message_element *el)
 142 {
 143         if (el != NULL) {
 144                 int k;
 145                 DATA_BLOB esf = data_blob_string_const(
 146                         SAMBA_ENCRYPTED_SECRETS_FEATURE);
 147                 DATA_BLOB lmdbl1 = data_blob_string_const(
 148                         SAMBA_LMDB_LEVEL_ONE_FEATURE);
 149                 for (k = 0; k < el->num_values; k++) {
 150                         if ((data_blob_cmp(&esf, &el->values[k]) != 0) &&
 151                             (data_blob_cmp(&lmdbl1, &el->values[k]) != 0)) {
 152                                 return false;
 153                         }
 154                 }
 155         }
 156         return true;
 157 }
 158
 159 static int samba_dsdb_init(struct ldb_module *module)
 160 {
 161         struct ldb_context *ldb = ldb_module_get_ctx(module);
 162         int ret, lock_ret, len, i, j;
 163         TALLOC_CTX *tmp_ctx = talloc_new(module);
 164         struct ldb_result *res;
 165         struct ldb_message *rootdse_msg = NULL, *partition_msg;
 166         struct ldb_dn *samba_dsdb_dn, *partition_dn, *indexlist_dn;
 167         struct ldb_module *backend_module, *module_chain;
 168         const char **final_module_list, **reverse_module_list;
 169         /*
 170           Add modules to the list to activate them by default
 171           beware often order is important
 172
 173           Some Known ordering constraints:
 174           - rootdse must be first, as it makes redirects from "" -> cn=rootdse
 175           - extended_dn_in must be before objectclass.c, as it resolves the DN
 176           - objectclass must be before password_hash and samldb since these LDB
 177             modules require the expanded "objectClass" list
 178           - objectclass must be before descriptor and acl, as both assume that
 179             objectClass values are sorted
 180           - objectclass_attrs must be behind operational in order to see all
 181             attributes (the operational module protects and therefore
 182             suppresses per default some important ones)
 183           - partition must be last
 184           - each partition has its own module list then
 185
 186           The list is presented here as a set of declarations to show the
 187           stack visually - the code below then handles the creation of the list
 188           based on the parameters loaded from the database.
 189         */
 190         static const char *modules_list1[] = {"resolve_oids",
 191                                              "rootdse",
 192                                              "dsdb_notification",
 193                                              "schema_load",
 194                                              "lazy_commit",
 195                                              "dirsync",
 196                                              "dsdb_paged_results",
 197                                              "vlv",
 198                                              "ranged_results",
 199                                              "anr",
 200                                              "server_sort",
 201                                              "asq",
 202                                              "extended_dn_store",
 203                                              NULL };
 204         /* extended_dn_in or extended_dn_in_openldap goes here */
 205         static const char *modules_list1a[] = {"audit_log",
 206                                              "objectclass",
 207                                              "tombstone_reanimate",
 208                                              "descriptor",
 209                                              "acl",
 210                                              "aclread",
 211                                              "samldb",
 212                                              "password_hash",
 213                                              "instancetype",
 214                                              "objectclass_attrs",
 215                                              NULL };
 216
 217         const char **link_modules;
 218         static const char *tdb_modules_list[] = {
 219                 "rdn_name",
 220                 "subtree_delete",
 221                 "repl_meta_data",
 222                 "group_audit_log",
 223                 "encrypted_secrets",
 224                 "operational",
 225                 "unique_object_sids",
 226                 "subtree_rename",
 227                 "linked_attributes",
 228                 NULL};
 229
 230         const char *extended_dn_module;
 231         const char *extended_dn_module_ldb = "extended_dn_out_ldb";
 232         const char *extended_dn_in_module = "extended_dn_in";
 233
 234         static const char *modules_list2[] = {"dns_notify",
 235                                               "show_deleted",
 236                                               "new_partition",
 237                                               "partition",
 238                                               NULL };
 239
 240         const char **backend_modules;
 241         static const char *samba_dsdb_attrs[] = { SAMBA_COMPATIBLE_FEATURES_ATTR,
 242                                                   SAMBA_REQUIRED_FEATURES_ATTR, NULL };
 243         static const char *indexlist_attrs[] = { SAMBA_FEATURES_SUPPORTED_FLAG, NULL };
 244
 245         const char *current_supportedFeatures[] = {SAMBA_SORTED_LINKS_FEATURE};
 246
 247         if (!tmp_ctx) {
 248                 return ldb_oom(ldb);
 249         }
 250
 251         ret = ldb_register_samba_handlers(ldb);
 252         if (ret != LDB_SUCCESS) {
 253                 talloc_free(tmp_ctx);
 254                 return ret;
 255         }
 256
 257         samba_dsdb_dn = ldb_dn_new(tmp_ctx, ldb, "@SAMBA_DSDB");
 258         if (!samba_dsdb_dn) {
 259                 talloc_free(tmp_ctx);
 260                 return ldb_oom(ldb);
 261         }
 262
 263         indexlist_dn = ldb_dn_new(tmp_ctx, ldb, "@INDEXLIST");
 264         if (!samba_dsdb_dn) {
 265                 talloc_free(tmp_ctx);
 266                 return ldb_oom(ldb);
 267         }
 268
 269         partition_dn = ldb_dn_new(tmp_ctx, ldb, DSDB_PARTITION_DN);
 270         if (!partition_dn) {
 271                 talloc_free(tmp_ctx);
 272                 return ldb_oom(ldb);
 273         }
 274
 275 #define CHECK_LDB_RET(check_ret)                                \
 276         do {                                                    \
 277                 if (check_ret != LDB_SUCCESS) {                 \
 278                         talloc_free(tmp_ctx);                   \
 279                         return check_ret;                       \
 280                 }                                               \
 281         } while (0)
 282
 283         ret = dsdb_module_search_dn(module, tmp_ctx, &res, samba_dsdb_dn,
 284                                     samba_dsdb_attrs, DSDB_FLAG_NEXT_MODULE, NULL);
 285         if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 286                 /* do nothing, a very old db being upgraded */
 287         } else if (ret == LDB_SUCCESS) {
 288                 struct ldb_message_element *requiredFeatures;
 289                 struct ldb_message_element *old_compatibleFeatures;
 290
 291                 requiredFeatures = ldb_msg_find_element(res->msgs[0], SAMBA_REQUIRED_FEATURES_ATTR);
 292                 if (!check_required_features(requiredFeatures)) {
 293                         ldb_set_errstring(
 294                                 ldb,
 295                                 "This Samba database was created with "
 296                                 "a newer Samba version and is marked "
 297                                 "with extra requiredFeatures in "
 298                                 "@SAMBA_DSDB. This database can not "
 299                                 "safely be read by this Samba version");
 300                         return LDB_ERR_OPERATIONS_ERROR;
 301                 }
 302
 303                 old_compatibleFeatures = ldb_msg_find_element(res->msgs[0],
 304                                                               SAMBA_COMPATIBLE_FEATURES_ATTR);
 305
 306                 if (old_compatibleFeatures) {
 307                         struct ldb_message *features_msg;
 308                         struct ldb_message_element *features_el;
 309                         int samba_options_supported = 0;
 310                         ret = dsdb_module_search_dn(module, tmp_ctx, &res,
 311                                                     indexlist_dn,
 312                                                     indexlist_attrs,
 313                                                     DSDB_FLAG_NEXT_MODULE, NULL);
 314                         if (ret == LDB_SUCCESS) {
 315                                 samba_options_supported
 316                                         = ldb_msg_find_attr_as_int(res->msgs[0],
 317                                                                    SAMBA_FEATURES_SUPPORTED_FLAG,
 318                                                                    0);
 319
 320                         } else if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 321                                 /*
 322                                  * If we don't have @INDEXLIST yet, then we
 323                                  * are so early in set-up that we know this is
 324                                  * a blank DB, so no need to wripe out old
 325                                  * features
 326                                  */
 327                                 samba_options_supported = 1;
 328                         }
 329
 330                         features_msg = ldb_msg_new(res);
 331                         if (features_msg == NULL) {
 332                                 return ldb_module_operr(module);
 333                         }
 334                         features_msg->dn = samba_dsdb_dn;
 335
 336                         ret = ldb_msg_add_empty(features_msg, SAMBA_COMPATIBLE_FEATURES_ATTR,
 337                                                 LDB_FLAG_MOD_DELETE, &features_el);
 338                         if (ret != LDB_SUCCESS) {
 339                                 return ret;
 340                         }
 341
 342                         if (samba_options_supported == 1) {
 343                                 for (i = 0;
 344                                      old_compatibleFeatures && i < old_compatibleFeatures->num_values;
 345                                      i++) {
 346                                         for (j = 0;
 347                                              j < ARRAY_SIZE(current_supportedFeatures); j++) {
 348                                                 if (strcmp((char *)old_compatibleFeatures->values[i].data,
 349                                                            current_supportedFeatures[j]) == 0) {
 350                                                         break;
 351                                                 }
 352                                         }
 353                                         if (j == ARRAY_SIZE(current_supportedFeatures)) {
 354                                                 /*
 355                                                  * Add to list of features to remove
 356                                                  * (rather than all features)
 357                                                  */
 358                                                 ret = ldb_msg_add_value(features_msg, SAMBA_COMPATIBLE_FEATURES_ATTR,
 359                                                                         &old_compatibleFeatures->values[i],
 360                                                                         NULL);
 361                                                 if (ret != LDB_SUCCESS) {
 362                                                         return ret;
 363                                                 }
 364                                         }
 365                                 }
 366
 367                                 if (features_el->num_values > 0) {
 368                                         /* Delete by list */
 369                                         ret = ldb_next_start_trans(module);
 370                                         if (ret != LDB_SUCCESS) {
 371                                                 return ret;
 372                                         }
 373                                         ret = dsdb_module_modify(module, features_msg, DSDB_FLAG_NEXT_MODULE, NULL);
 374                                         if (ret != LDB_SUCCESS) {
 375                                                 ldb_next_del_trans(module);
 376                                                 return ret;
 377                                         }
 378                                         ret = ldb_next_end_trans(module);
 379                                         if (ret != LDB_SUCCESS) {
 380                                                 return ret;
 381                                         }
 382                                 }
 383                         } else {
 384                                 /* Delete all */
 385                                 ret = ldb_next_start_trans(module);
 386                                 if (ret != LDB_SUCCESS) {
 387                                         return ret;
 388                                 }
 389                                 ret = dsdb_module_modify(module, features_msg, DSDB_FLAG_NEXT_MODULE, NULL);
 390                                 if (ret != LDB_SUCCESS) {
 391                                         ldb_next_del_trans(module);
 392                                         return ret;
 393                                 }
 394                                 ret = ldb_next_end_trans(module);
 395                                 if (ret != LDB_SUCCESS) {
 396                                         return ret;
 397                                 }
 398                         }
 399                 }
 400
 401         } else {
 402                 talloc_free(tmp_ctx);
 403                 return ret;
 404         }
 405
 406         backend_modules = NULL;
 407         extended_dn_module = extended_dn_module_ldb;
 408         link_modules = tdb_modules_list;
 409
 410 #define CHECK_MODULE_LIST \
 411         do {                                                    \
 412                 if (!final_module_list) {                       \
 413                         talloc_free(tmp_ctx);                   \
 414                         return ldb_oom(ldb);                    \
 415                 }                                               \
 416         } while (0)
 417
 418         final_module_list = str_list_copy_const(tmp_ctx, modules_list1);
 419         CHECK_MODULE_LIST;
 420
 421         final_module_list = str_list_add_const(final_module_list, extended_dn_in_module);
 422         CHECK_MODULE_LIST;
 423
 424         final_module_list = str_list_append_const(final_module_list, modules_list1a);
 425         CHECK_MODULE_LIST;
 426
 427         final_module_list = str_list_append_const(final_module_list, link_modules);
 428         CHECK_MODULE_LIST;
 429
 430         final_module_list = str_list_add_const(final_module_list, extended_dn_module);
 431         CHECK_MODULE_LIST;
 432
 433         final_module_list = str_list_append_const(final_module_list, modules_list2);
 434         CHECK_MODULE_LIST;
 435
 436
 437         ret = read_at_rootdse_record(ldb, module, tmp_ctx, &rootdse_msg, NULL);
 438         CHECK_LDB_RET(ret);
 439
 440         partition_msg = ldb_msg_new(tmp_ctx);
 441         partition_msg->dn = ldb_dn_new(partition_msg, ldb, "@" DSDB_OPAQUE_PARTITION_MODULE_MSG_OPAQUE_NAME);
 442
 443         ret = prepare_modules_line(ldb, tmp_ctx,
 444                                    rootdse_msg,
 445                                    partition_msg, "schemaNamingContext",
 446                                    "schema_data", backend_modules);
 447         CHECK_LDB_RET(ret);
 448
 449         ret = prepare_modules_line(ldb, tmp_ctx,
 450                                    rootdse_msg,
 451                                    partition_msg, NULL,
 452                                    NULL, backend_modules);
 453         CHECK_LDB_RET(ret);
 454
 455         /* This opaque is also used by the gMSA code to confirm that it has local DB access */
 456         ret = ldb_set_opaque(ldb, DSDB_OPAQUE_PARTITION_MODULE_MSG_OPAQUE_NAME, partition_msg);
 457         CHECK_LDB_RET(ret);
 458
 459         talloc_steal(ldb, partition_msg);
 460
 461         /* Now prepare the module chain. Oddly, we must give it to
 462          * ldb_module_load_list in REVERSE */
 463         for (len = 0; final_module_list[len]; len++) { /* noop */};
 464
 465         reverse_module_list = talloc_array(tmp_ctx, const char *, len+1);
 466         if (!reverse_module_list) {
 467                 talloc_free(tmp_ctx);
 468                 return ldb_oom(ldb);
 469         }
 470         for (i=0; i < len; i++) {
 471                 reverse_module_list[i] = final_module_list[(len - 1) - i];
 472         }
 473         reverse_module_list[i] = NULL;
 474
 475         /* The backend (at least until the partitions module
 476          * reconfigures things) is the next module in the currently
 477          * loaded chain */
 478         backend_module = ldb_module_next(module);
 479         ret = ldb_module_load_list(ldb, reverse_module_list, backend_module, &module_chain);
 480         CHECK_LDB_RET(ret);
 481
 482         talloc_free(tmp_ctx);
 483         /* Set this as the 'next' module, so that we effectively append it to
 484          * module chain */
 485         ldb_module_set_next(module, module_chain);
 486
 487         ret = ldb_next_read_lock(module);
 488         if (ret != LDB_SUCCESS) {
 489                 return ret;
 490         }
 491
 492         ret = ldb_next_init(module);
 493
 494         lock_ret = ldb_next_read_unlock(module);
 495
 496         if (lock_ret != LDB_SUCCESS) {
 497                 return lock_ret;
 498         }
 499
 500         return ret;
 501 }
 502
 503 static const struct ldb_module_ops ldb_samba_dsdb_module_ops = {
 504         .name              = "samba_dsdb",
 505         .init_context      = samba_dsdb_init,
 506 };
 507
 508 static struct ldb_message *dsdb_flags_ignore_fixup(TALLOC_CTX *mem_ctx,
 509                                                 const struct ldb_message *_msg)
 510 {
 511         struct ldb_message *msg = NULL;
 512         unsigned int i;
 513
 514         /* we have to copy the message as the caller might have it as a const */
 515         msg = ldb_msg_copy_shallow(mem_ctx, _msg);
 516         if (msg == NULL) {
 517                 return NULL;
 518         }
 519
 520         for (i=0; i < msg->num_elements;) {
 521                 struct ldb_message_element *e = &msg->elements[i];
 522
 523                 if (!(e->flags & DSDB_FLAG_INTERNAL_FORCE_META_DATA)) {
 524                         i++;
 525                         continue;
 526                 }
 527
 528                 e->flags &= ~DSDB_FLAG_INTERNAL_FORCE_META_DATA;
 529
 530                 if (e->num_values != 0) {
 531                         i++;
 532                         continue;
 533                 }
 534
 535                 ldb_msg_remove_element(msg, e);
 536         }
 537
 538         return msg;
 539 }
 540
 541 static int dsdb_flags_ignore_add(struct ldb_module *module, struct ldb_request *req)
 542 {
 543         struct ldb_context *ldb = ldb_module_get_ctx(module);
 544         struct ldb_request *down_req = NULL;
 545         struct ldb_message *msg = NULL;
 546         int ret;
 547
 548         msg = dsdb_flags_ignore_fixup(req, req->op.add.message);
 549         if (msg == NULL) {
 550                 return ldb_module_oom(module);
 551         }
 552
 553         ret = ldb_build_add_req(&down_req, ldb, req,
 554                                 msg,
 555                                 req->controls,
 556                                 req, dsdb_next_callback,
 557                                 req);
 558         LDB_REQ_SET_LOCATION(down_req);
 559         if (ret != LDB_SUCCESS) {
 560                 return ret;
 561         }
 562
 563         /* go on with the call chain */
 564         return ldb_next_request(module, down_req);
 565 }
 566
 567 static int dsdb_flags_ignore_modify(struct ldb_module *module, struct ldb_request *req)
 568 {
 569         struct ldb_context *ldb = ldb_module_get_ctx(module);
 570         struct ldb_request *down_req = NULL;
 571         struct ldb_message *msg = NULL;
 572         int ret;
 573
 574         msg = dsdb_flags_ignore_fixup(req, req->op.mod.message);
 575         if (msg == NULL) {
 576                 return ldb_module_oom(module);
 577         }
 578
 579         ret = ldb_build_mod_req(&down_req, ldb, req,
 580                                 msg,
 581                                 req->controls,
 582                                 req, dsdb_next_callback,
 583                                 req);
 584         LDB_REQ_SET_LOCATION(down_req);
 585         if (ret != LDB_SUCCESS) {
 586                 return ret;
 587         }
 588
 589         /* go on with the call chain */
 590         return ldb_next_request(module, down_req);
 591 }
 592
 593 static const struct ldb_module_ops ldb_dsdb_flags_ignore_module_ops = {
 594         .name   = "dsdb_flags_ignore",
 595         .add    = dsdb_flags_ignore_add,
 596         .modify = dsdb_flags_ignore_modify,
 597 };
 598
 599 int ldb_samba_dsdb_module_init(const char *version)
 600 {
 601         int ret;
 602         LDB_MODULE_CHECK_VERSION(version);
 603         ret = ldb_register_module(&ldb_samba_dsdb_module_ops);
 604         if (ret != LDB_SUCCESS) {
 605                 return ret;
 606         }
 607         ret = ldb_register_module(&ldb_dsdb_flags_ignore_module_ops);
 608         if (ret != LDB_SUCCESS) {
 609                 return ret;
 610         }
 611         return LDB_SUCCESS;
 612 }