source4/dsdb/samdb/ldb_modules/extended_dn_store.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce 2005-2008
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007-2009
   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  *  Name: ldb
  23  *
  24  *  Component: ldb extended dn control module
  25  *
  26  *  Description: this module builds a special dn for returned search
  27  *  results nad creates the special DN in the backend store for new
  28  *  values.
  29  *
  30  *  This also has the curious result that we convert <SID=S-1-2-345>
  31  *  in an attribute value into a normal DN for the rest of the stack
  32  *  to process
  33  *
  34  *  Authors: Simo Sorce
  35  *           Andrew Bartlett
  36  */
  37
  38 #include "includes.h"
  39 #include "ldb/include/ldb.h"
  40 #include "ldb/include/ldb_errors.h"
  41 #include "ldb/include/ldb_module.h"
  42 #include "librpc/gen_ndr/ndr_misc.h"
  43 #include "dsdb/samdb/samdb.h"
  44 #include "libcli/security/security.h"
  45
  46 #include <time.h>
  47
  48 struct extended_dn_replace_list {
  49         struct extended_dn_replace_list *next;
  50         struct dsdb_dn *dsdb_dn;
  51         TALLOC_CTX *mem_ctx;
  52         struct ldb_val *replace_dn;
  53         struct extended_dn_context *ac;
  54         struct ldb_request *search_req;
  55 };
  56
  57
  58 struct extended_dn_context {
  59         const struct dsdb_schema *schema;
  60         struct ldb_module *module;
  61         struct ldb_context *ldb;
  62         struct ldb_request *req;
  63         struct ldb_request *new_req;
  64
  65         struct extended_dn_replace_list *ops;
  66         struct extended_dn_replace_list *cur;
  67 };
  68
  69
  70 static struct extended_dn_context *extended_dn_context_init(struct ldb_module *module,
  71                                                             struct ldb_request *req)
  72 {
  73         struct extended_dn_context *ac;
  74         struct ldb_context *ldb = ldb_module_get_ctx(module);
  75         ac = talloc_zero(req, struct extended_dn_context);
  76         if (ac == NULL) {
  77                 ldb_oom(ldb);
  78                 return NULL;
  79         }
  80
  81         ac->schema = dsdb_get_schema(ldb_module_get_ctx(module));
  82         ac->module = module;
  83         ac->ldb = ldb;
  84         ac->req = req;
  85
  86         return ac;
  87 }
  88
  89 /* An extra layer of indirection because LDB does not allow the original request to be altered */
  90
  91 static int extended_final_callback(struct ldb_request *req, struct ldb_reply *ares)
  92 {
  93         int ret = LDB_ERR_OPERATIONS_ERROR;
  94         struct extended_dn_context *ac;
  95         ac = talloc_get_type(req->context, struct extended_dn_context);
  96
  97         if (ares->error != LDB_SUCCESS) {
  98                 ret = ldb_module_done(ac->req, ares->controls,
  99                                       ares->response, ares->error);
 100         } else {
 101                 switch (ares->type) {
 102                 case LDB_REPLY_ENTRY:
 103
 104                         ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
 105                         break;
 106                 case LDB_REPLY_REFERRAL:
 107
 108                         ret = ldb_module_send_referral(ac->req, ares->referral);
 109                         break;
 110                 case LDB_REPLY_DONE:
 111
 112                         ret = ldb_module_done(ac->req, ares->controls,
 113                                               ares->response, ares->error);
 114                         break;
 115                 }
 116         }
 117         return ret;
 118 }
 119
 120 static int extended_replace_dn(struct ldb_request *req, struct ldb_reply *ares)
 121 {
 122         struct extended_dn_replace_list *os = talloc_get_type(req->context,
 123                                                            struct extended_dn_replace_list);
 124
 125         if (!ares) {
 126                 return ldb_module_done(os->ac->req, NULL, NULL,
 127                                         LDB_ERR_OPERATIONS_ERROR);
 128         }
 129         if (ares->error == LDB_ERR_NO_SUCH_OBJECT) {
 130                 /* Don't worry too much about dangling references */
 131
 132                 ldb_reset_err_string(os->ac->ldb);
 133                 if (os->next) {
 134                         struct extended_dn_replace_list *next;
 135
 136                         next = os->next;
 137
 138                         talloc_free(os);
 139
 140                         os = next;
 141                         return ldb_next_request(os->ac->module, next->search_req);
 142                 } else {
 143                         /* Otherwise, we are done - let's run the
 144                          * request now we have swapped the DNs for the
 145                          * full versions */
 146                         return ldb_next_request(os->ac->module, os->ac->req);
 147                 }
 148         }
 149         if (ares->error != LDB_SUCCESS) {
 150                 return ldb_module_done(os->ac->req, ares->controls,
 151                                         ares->response, ares->error);
 152         }
 153
 154         /* Only entries are interesting, and we only want the olddn */
 155         switch (ares->type) {
 156         case LDB_REPLY_ENTRY:
 157         {
 158                 /* This *must* be the right DN, as this is a base
 159                  * search.  We can't check, as it could be an extended
 160                  * DN, so a module below will resolve it */
 161                 struct ldb_dn *dn = ares->message->dn;
 162
 163                 /* Rebuild with the string or binary 'extra part' the
 164                  * DN may have had as a prefix */
 165                 struct dsdb_dn *dsdb_dn = dsdb_dn_construct(ares, dn,
 166                                                             os->dsdb_dn->extra_part,
 167                                                             os->dsdb_dn->oid);
 168                 if (dsdb_dn) {
 169                         /* Replace the DN with the extended version of the DN
 170                          * (ie, add SID and GUID) */
 171                         *os->replace_dn = data_blob_string_const(
 172                                 dsdb_dn_get_extended_linearized(os->mem_ctx,
 173                                                                 dsdb_dn, 1));
 174                         talloc_free(dsdb_dn);
 175                 }
 176                 if (os->replace_dn->data == NULL) {
 177                         return ldb_module_done(os->ac->req, NULL, NULL,
 178                                                 LDB_ERR_OPERATIONS_ERROR);
 179                 }
 180                 break;
 181         }
 182         case LDB_REPLY_REFERRAL:
 183                 /* ignore */
 184                 break;
 185
 186         case LDB_REPLY_DONE:
 187
 188                 talloc_free(ares);
 189
 190                 /* Run the next search */
 191
 192                 if (os->next) {
 193                         struct extended_dn_replace_list *next;
 194
 195                         next = os->next;
 196
 197                         talloc_free(os);
 198
 199                         os = next;
 200                         return ldb_next_request(os->ac->module, next->search_req);
 201                 } else {
 202                         /* Otherwise, we are done - let's run the
 203                          * request now we have swapped the DNs for the
 204                          * full versions */
 205                         return ldb_next_request(os->ac->module, os->ac->new_req);
 206                 }
 207         }
 208
 209         talloc_free(ares);
 210         return LDB_SUCCESS;
 211 }
 212
 213 /* We have a 'normal' DN in the inbound request.  We need to find out
 214  * what the GUID and SID are on the DN it points to, so we can
 215  * construct an extended DN for storage.
 216  *
 217  * This creates a list of DNs to look up, and the plain DN to replace
 218  */
 219
 220 static int extended_store_replace(struct extended_dn_context *ac,
 221                                   TALLOC_CTX *callback_mem_ctx,
 222                                   struct ldb_val *plain_dn,
 223                                   bool is_delete,
 224                                   const char *oid)
 225 {
 226         int ret;
 227         struct extended_dn_replace_list *os;
 228         static const char *attrs[] = {
 229                 "objectSid",
 230                 "objectGUID",
 231                 NULL
 232         };
 233
 234         os = talloc_zero(ac, struct extended_dn_replace_list);
 235         if (!os) {
 236                 return LDB_ERR_OPERATIONS_ERROR;
 237         }
 238
 239         os->ac = ac;
 240
 241         os->mem_ctx = callback_mem_ctx;
 242
 243         os->dsdb_dn = dsdb_dn_parse(os, ac->ldb, plain_dn, oid);
 244         if (!os->dsdb_dn || !ldb_dn_validate(os->dsdb_dn->dn)) {
 245                 talloc_free(os);
 246                 ldb_asprintf_errstring(ac->ldb,
 247                                        "could not parse %.*s as a %s DN", (int)plain_dn->length, plain_dn->data,
 248                                        oid);
 249                 return LDB_ERR_INVALID_DN_SYNTAX;
 250         }
 251
 252         if (is_delete && !ldb_dn_has_extended(os->dsdb_dn->dn)) {
 253                 /* NO need to figure this DN out, this element is
 254                  * going to be deleted anyway, and becuase it's not
 255                  * extended, we have enough information to do the
 256                  * delete */
 257                 talloc_free(os);
 258                 return LDB_SUCCESS;
 259         }
 260
 261
 262         os->replace_dn = plain_dn;
 263
 264         /* The search request here might happen to be for an
 265          * 'extended' style DN, such as <GUID=abced...>.  The next
 266          * module in the stack will convert this into a normal DN for
 267          * processing */
 268         ret = ldb_build_search_req(&os->search_req,
 269                                    ac->ldb, os, os->dsdb_dn->dn, LDB_SCOPE_BASE, NULL,
 270                                    attrs, NULL, os, extended_replace_dn,
 271                                    ac->req);
 272
 273         if (ret != LDB_SUCCESS) {
 274                 talloc_free(os);
 275                 return ret;
 276         }
 277
 278         ret = ldb_request_add_control(os->search_req,
 279                                       DSDB_CONTROL_DN_STORAGE_FORMAT_OID,
 280                                       true, NULL);
 281         if (ret != LDB_SUCCESS) {
 282                 talloc_free(os);
 283                 return ret;
 284         }
 285
 286         if (ac->ops) {
 287                 ac->cur->next = os;
 288         } else {
 289                 ac->ops = os;
 290         }
 291         ac->cur = os;
 292
 293         return LDB_SUCCESS;
 294 }
 295
 296
 297 /* add */
 298 static int extended_dn_add(struct ldb_module *module, struct ldb_request *req)
 299 {
 300         struct extended_dn_context *ac;
 301         int ret;
 302         int i, j;
 303
 304         if (ldb_dn_is_special(req->op.add.message->dn)) {
 305                 /* do not manipulate our control entries */
 306                 return ldb_next_request(module, req);
 307         }
 308
 309         ac = extended_dn_context_init(module, req);
 310         if (!ac) {
 311                 return LDB_ERR_OPERATIONS_ERROR;
 312         }
 313
 314         if (!ac->schema) {
 315                 /* without schema, this doesn't make any sense */
 316                 talloc_free(ac);
 317                 return ldb_next_request(module, req);
 318         }
 319
 320         for (i=0; i < req->op.add.message->num_elements; i++) {
 321                 const struct ldb_message_element *el = &req->op.add.message->elements[i];
 322                 const struct dsdb_attribute *schema_attr
 323                         = dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
 324                 if (!schema_attr) {
 325                         continue;
 326                 }
 327
 328                 /* We only setup an extended DN GUID on DN elements */
 329                 if (dsdb_dn_oid_to_format(schema_attr->syntax->ldap_oid) == DSDB_INVALID_DN) {
 330                         continue;
 331                 }
 332
 333                 /* Before we setup a procedure to modify the incoming message, we must copy it */
 334                 if (!ac->new_req) {
 335                         struct ldb_message *msg = ldb_msg_copy(ac, req->op.add.message);
 336                         if (!msg) {
 337                                 ldb_oom(ldb_module_get_ctx(module));
 338                                 return LDB_ERR_OPERATIONS_ERROR;
 339                         }
 340
 341                         ret = ldb_build_add_req(&ac->new_req, ac->ldb, ac, msg, req->controls, ac, extended_final_callback, req);
 342                         if (ret != LDB_SUCCESS) {
 343                                 return ret;
 344                         }
 345                 }
 346                 /* Re-calculate el */
 347                 el = &ac->new_req->op.add.message->elements[i];
 348                 for (j = 0; j < el->num_values; j++) {
 349                         ret = extended_store_replace(ac, ac->new_req->op.add.message->elements, &el->values[j],
 350                                                      false, schema_attr->syntax->ldap_oid);
 351                         if (ret != LDB_SUCCESS) {
 352                                 return ret;
 353                         }
 354                 }
 355         }
 356
 357         /* if no DNs were set continue */
 358         if (ac->ops == NULL) {
 359                 talloc_free(ac);
 360                 return ldb_next_request(module, req);
 361         }
 362
 363         /* start with the searches */
 364         return ldb_next_request(module, ac->ops->search_req);
 365 }
 366
 367 /* modify */
 368 static int extended_dn_modify(struct ldb_module *module, struct ldb_request *req)
 369 {
 370         /* Look over list of modifications */
 371         /* Find if any are for linked attributes */
 372         /* Determine the effect of the modification */
 373         /* Apply the modify to the linked entry */
 374
 375         int i, j;
 376         struct extended_dn_context *ac;
 377         int ret;
 378
 379         if (ldb_dn_is_special(req->op.mod.message->dn)) {
 380                 /* do not manipulate our control entries */
 381                 return ldb_next_request(module, req);
 382         }
 383
 384         ac = extended_dn_context_init(module, req);
 385         if (!ac) {
 386                 return LDB_ERR_OPERATIONS_ERROR;
 387         }
 388
 389         if (!ac->schema) {
 390                 talloc_free(ac);
 391                 /* without schema, this doesn't make any sense */
 392                 return ldb_next_request(module, req);
 393         }
 394
 395         for (i=0; i < req->op.mod.message->num_elements; i++) {
 396                 const struct ldb_message_element *el = &req->op.mod.message->elements[i];
 397                 const struct dsdb_attribute *schema_attr
 398                         = dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
 399                 if (!schema_attr) {
 400                         continue;
 401                 }
 402
 403                 /* We only setup an extended DN GUID on these particular DN objects */
 404                 if (dsdb_dn_oid_to_format(schema_attr->syntax->ldap_oid) == DSDB_INVALID_DN) {
 405                         continue;
 406                 }
 407
 408                 /* Before we setup a procedure to modify the incoming message, we must copy it */
 409                 if (!ac->new_req) {
 410                         struct ldb_message *msg = ldb_msg_copy(ac, req->op.mod.message);
 411                         if (!msg) {
 412                                 talloc_free(ac);
 413                                 ldb_oom(ac->ldb);
 414                                 return LDB_ERR_OPERATIONS_ERROR;
 415                         }
 416
 417                         ret = ldb_build_mod_req(&ac->new_req, ac->ldb, ac, msg, req->controls, ac, extended_final_callback, req);
 418                         if (ret != LDB_SUCCESS) {
 419                                 talloc_free(ac);
 420                                 return ret;
 421                         }
 422                 }
 423                 /* Re-calculate el */
 424                 el = &ac->new_req->op.mod.message->elements[i];
 425                 /* For each value being added, we need to setup the lookups to fill in the extended DN */
 426                 for (j = 0; j < el->num_values; j++) {
 427                         /* If we are just going to delete this
 428                          * element, only do a lookup if
 429                          * extended_store_replace determines it's an
 430                          * input of an extended DN */
 431                         bool is_delete = ((el->flags & LDB_FLAG_MOD_MASK) == LDB_FLAG_MOD_DELETE);
 432
 433                         ret = extended_store_replace(ac, req->op.mod.message->elements, &el->values[j],
 434                                                      is_delete, schema_attr->syntax->ldap_oid);
 435                         if (ret != LDB_SUCCESS) {
 436                                 talloc_free(ac);
 437                                 return ret;
 438                         }
 439                 }
 440         }
 441
 442         /* if DNs were set continue */
 443         if (ac->ops == NULL) {
 444                 talloc_free(ac);
 445                 return ldb_next_request(module, req);
 446         }
 447
 448         /* start with the searches */
 449         return ldb_next_request(module, ac->ops->search_req);
 450 }
 451
 452 _PUBLIC_ const struct ldb_module_ops ldb_extended_dn_store_module_ops = {
 453         .name              = "extended_dn_store",
 454         .add               = extended_dn_add,
 455         .modify            = extended_dn_modify,
 456 };