source4/dsdb/samdb/ldb_modules/descriptor.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce  2006-2008
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2007
   6    Copyright (C) Nadezhda Ivanova  2009
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 /*
  23  *  Name: ldb
  24  *
  25  *  Component: DS Security descriptor module
  26  *
  27  *  Description:
  28  *  - Calculate the security descriptor of a newly created object
  29  *  - Perform sd recalculation on a move operation
  30  *  - Handle sd modification invariants
  31  *
  32  *  Author: Nadezhda Ivanova
  33  */
  34
  35 #include "includes.h"
  36 #include <ldb_module.h>
  37 #include "util/dlinklist.h"
  38 #include "dsdb/samdb/samdb.h"
  39 #include "librpc/ndr/libndr.h"
  40 #include "librpc/gen_ndr/ndr_security.h"
  41 #include "libcli/security/security.h"
  42 #include "dsdb/samdb/ldb_modules/schema.h"
  43 #include "auth/auth.h"
  44 #include "param/param.h"
  45 #include "dsdb/samdb/ldb_modules/util.h"
  46
  47 struct descriptor_data {
  48         int _dummy;
  49 };
  50
  51 struct descriptor_context {
  52         struct ldb_module *module;
  53         struct ldb_request *req;
  54         struct ldb_message *msg;
  55         struct ldb_reply *search_res;
  56         struct ldb_reply *search_oc_res;
  57         struct ldb_val *parentsd_val;
  58         struct ldb_message_element *sd_element;
  59         struct ldb_val *sd_val;
  60         int (*step_fn)(struct descriptor_context *);
  61 };
  62
  63 static struct dom_sid *get_default_ag(TALLOC_CTX *mem_ctx,
  64                                struct ldb_dn *dn,
  65                                struct security_token *token,
  66                                struct ldb_context *ldb)
  67 {
  68         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  69         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
  70         struct dom_sid *da_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_ADMINS);
  71         struct dom_sid *ea_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_ENTERPRISE_ADMINS);
  72         struct dom_sid *sa_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_SCHEMA_ADMINS);
  73         struct dom_sid *dag_sid;
  74         struct ldb_dn *nc_root;
  75         int ret;
  76
  77         ret = dsdb_find_nc_root(ldb, tmp_ctx, dn, &nc_root);
  78         if (ret != LDB_SUCCESS) {
  79                 talloc_free(tmp_ctx);
  80                 return NULL;
  81         }
  82
  83         if (ldb_dn_compare(nc_root, ldb_get_schema_basedn(ldb)) == 0) {
  84                 if (security_token_has_sid(token, sa_sid)) {
  85                         dag_sid = dom_sid_dup(mem_ctx, sa_sid);
  86                 } else if (security_token_has_sid(token, ea_sid)) {
  87                         dag_sid = dom_sid_dup(mem_ctx, ea_sid);
  88                 } else if (security_token_has_sid(token, da_sid)) {
  89                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
  90                 } else {
  91                         dag_sid = NULL;
  92                 }
  93         } else if (ldb_dn_compare(nc_root, ldb_get_config_basedn(ldb)) == 0) {
  94                 if (security_token_has_sid(token, ea_sid)) {
  95                         dag_sid = dom_sid_dup(mem_ctx, ea_sid);
  96                 } else if (security_token_has_sid(token, da_sid)) {
  97                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
  98                 } else {
  99                         dag_sid = NULL;
 100                 }
 101         } else if (ldb_dn_compare(nc_root, ldb_get_default_basedn(ldb)) == 0) {
 102                 if (security_token_has_sid(token, da_sid)) {
 103                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
 104                 } else if (security_token_has_sid(token, ea_sid)) {
 105                                 dag_sid = dom_sid_dup(mem_ctx, ea_sid);
 106                 } else {
 107                         dag_sid = NULL;
 108                 }
 109         } else {
 110                 dag_sid = NULL;
 111         }
 112
 113         talloc_free(tmp_ctx);
 114         return dag_sid;
 115 }
 116
 117 static struct security_descriptor *get_sd_unpacked(struct ldb_module *module, TALLOC_CTX *mem_ctx,
 118                                             const struct dsdb_class *objectclass)
 119 {
 120         struct ldb_context *ldb = ldb_module_get_ctx(module);
 121         struct security_descriptor *sd;
 122         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
 123
 124         if (!objectclass->defaultSecurityDescriptor || !domain_sid) {
 125                 return NULL;
 126         }
 127
 128         sd = sddl_decode(mem_ctx,
 129                          objectclass->defaultSecurityDescriptor,
 130                          domain_sid);
 131         return sd;
 132 }
 133
 134 static struct dom_sid *get_default_group(TALLOC_CTX *mem_ctx,
 135                                          struct ldb_context *ldb,
 136                                          struct dom_sid *dag)
 137 {
 138         if (dsdb_functional_level(ldb) >= DS_DOMAIN_FUNCTION_2008) {
 139                 return dag;
 140         }
 141
 142         return NULL;
 143 }
 144
 145 static struct security_descriptor *descr_handle_sd_flags(TALLOC_CTX *mem_ctx,
 146                                                          struct security_descriptor *new_sd,
 147                                                          struct security_descriptor *old_sd,
 148                                                          uint32_t sd_flags)
 149 {
 150         struct security_descriptor *final_sd;
 151         /* if there is no control or control == 0 modify everything */
 152         if (!sd_flags) {
 153                 return new_sd;
 154         }
 155
 156         final_sd = talloc_zero(mem_ctx, struct security_descriptor);
 157         final_sd->revision = SECURITY_DESCRIPTOR_REVISION_1;
 158         final_sd->type = SEC_DESC_SELF_RELATIVE;
 159
 160         if (sd_flags & (SECINFO_OWNER)) {
 161                 final_sd->owner_sid = talloc_memdup(mem_ctx, new_sd->owner_sid, sizeof(struct dom_sid));
 162                 final_sd->type |= new_sd->type & SEC_DESC_OWNER_DEFAULTED;
 163         }
 164         else if (old_sd) {
 165                 final_sd->owner_sid = talloc_memdup(mem_ctx, old_sd->owner_sid, sizeof(struct dom_sid));
 166                 final_sd->type |= old_sd->type & SEC_DESC_OWNER_DEFAULTED;
 167         }
 168
 169         if (sd_flags & (SECINFO_GROUP)) {
 170                 final_sd->group_sid = talloc_memdup(mem_ctx, new_sd->group_sid, sizeof(struct dom_sid));
 171                 final_sd->type |= new_sd->type & SEC_DESC_GROUP_DEFAULTED;
 172         }
 173         else if (old_sd) {
 174                 final_sd->group_sid = talloc_memdup(mem_ctx, old_sd->group_sid, sizeof(struct dom_sid));
 175                 final_sd->type |= old_sd->type & SEC_DESC_GROUP_DEFAULTED;
 176         }
 177
 178         if (sd_flags & (SECINFO_SACL)) {
 179                 final_sd->sacl = security_acl_dup(mem_ctx,new_sd->sacl);
 180                 final_sd->type |= new_sd->type & (SEC_DESC_SACL_PRESENT |
 181                         SEC_DESC_SACL_DEFAULTED|SEC_DESC_SACL_AUTO_INHERIT_REQ |
 182                         SEC_DESC_SACL_AUTO_INHERITED|SEC_DESC_SACL_PROTECTED |
 183                         SEC_DESC_SERVER_SECURITY);
 184         }
 185         else if (old_sd && old_sd->sacl) {
 186                 final_sd->sacl = security_acl_dup(mem_ctx,old_sd->sacl);
 187                 final_sd->type |= old_sd->type & (SEC_DESC_SACL_PRESENT |
 188                         SEC_DESC_SACL_DEFAULTED|SEC_DESC_SACL_AUTO_INHERIT_REQ |
 189                         SEC_DESC_SACL_AUTO_INHERITED|SEC_DESC_SACL_PROTECTED |
 190                         SEC_DESC_SERVER_SECURITY);
 191         }
 192
 193         if (sd_flags & (SECINFO_DACL)) {
 194                 final_sd->dacl = security_acl_dup(mem_ctx,new_sd->dacl);
 195                 final_sd->type |= new_sd->type & (SEC_DESC_DACL_PRESENT |
 196                         SEC_DESC_DACL_DEFAULTED|SEC_DESC_DACL_AUTO_INHERIT_REQ |
 197                         SEC_DESC_DACL_AUTO_INHERITED|SEC_DESC_DACL_PROTECTED |
 198                         SEC_DESC_DACL_TRUSTED);
 199         }
 200         else if (old_sd && old_sd->dacl) {
 201                 final_sd->dacl = security_acl_dup(mem_ctx,old_sd->dacl);
 202                 final_sd->type |= old_sd->type & (SEC_DESC_DACL_PRESENT |
 203                         SEC_DESC_DACL_DEFAULTED|SEC_DESC_DACL_AUTO_INHERIT_REQ |
 204                         SEC_DESC_DACL_AUTO_INHERITED|SEC_DESC_DACL_PROTECTED |
 205                         SEC_DESC_DACL_TRUSTED);
 206         }
 207         /* not so sure about this */
 208         final_sd->type |= new_sd->type & SEC_DESC_RM_CONTROL_VALID;
 209         return final_sd;
 210 }
 211
 212 static DATA_BLOB *get_new_descriptor(struct ldb_module *module,
 213                                      struct ldb_dn *dn,
 214                                      TALLOC_CTX *mem_ctx,
 215                                      const struct dsdb_class *objectclass,
 216                                      const struct ldb_val *parent,
 217                                      const struct ldb_val *object,
 218                                      const struct ldb_val *old_sd,
 219                                      uint32_t sd_flags)
 220 {
 221         struct security_descriptor *user_descriptor = NULL, *parent_descriptor = NULL;
 222         struct security_descriptor *old_descriptor = NULL;
 223         struct security_descriptor *new_sd, *final_sd;
 224         DATA_BLOB *linear_sd;
 225         enum ndr_err_code ndr_err;
 226         struct ldb_context *ldb = ldb_module_get_ctx(module);
 227         struct auth_session_info *session_info
 228                 = ldb_get_opaque(ldb, "sessionInfo");
 229         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
 230         char *sddl_sd;
 231         struct dom_sid *default_owner;
 232         struct dom_sid *default_group;
 233
 234         if (object) {
 235                 user_descriptor = talloc(mem_ctx, struct security_descriptor);
 236                 if (!user_descriptor) {
 237                         return NULL;
 238                 }
 239                 ndr_err = ndr_pull_struct_blob(object, user_descriptor,
 240                                                user_descriptor,
 241                                                (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 242
 243                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 244                         talloc_free(user_descriptor);
 245                         return NULL;
 246                 }
 247         } else {
 248                 user_descriptor = get_sd_unpacked(module, mem_ctx, objectclass);
 249         }
 250
 251         if (old_sd) {
 252                 old_descriptor = talloc(mem_ctx, struct security_descriptor);
 253                 if (!old_descriptor) {
 254                         return NULL;
 255                 }
 256                 ndr_err = ndr_pull_struct_blob(old_sd, old_descriptor,
 257                                                old_descriptor,
 258                                                (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 259
 260                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 261                         talloc_free(old_descriptor);
 262                         return NULL;
 263                 }
 264         }
 265
 266         if (parent) {
 267                 parent_descriptor = talloc(mem_ctx, struct security_descriptor);
 268                 if (!parent_descriptor) {
 269                         return NULL;
 270                 }
 271                 ndr_err = ndr_pull_struct_blob(parent, parent_descriptor,
 272                                                parent_descriptor,
 273                                                (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 274
 275                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 276                         talloc_free(parent_descriptor);
 277                         return NULL;
 278                 }
 279         }
 280
 281         default_owner = get_default_ag(mem_ctx, dn,
 282                                        session_info->security_token, ldb);
 283         default_group = get_default_group(mem_ctx, ldb, default_owner);
 284         new_sd = create_security_descriptor(mem_ctx, parent_descriptor, user_descriptor, true,
 285                                             NULL, SEC_DACL_AUTO_INHERIT|SEC_SACL_AUTO_INHERIT,
 286                                             session_info->security_token,
 287                                             default_owner, default_group,
 288                                             map_generic_rights_ds);
 289         if (!new_sd) {
 290                 return NULL;
 291         }
 292         final_sd = descr_handle_sd_flags(mem_ctx, new_sd, old_descriptor, sd_flags);
 293
 294         if (!final_sd) {
 295                 return NULL;
 296         }
 297
 298         if (final_sd->dacl) {
 299                 final_sd->dacl->revision = SECURITY_ACL_REVISION_ADS;
 300         }
 301         if (final_sd->sacl) {
 302                 final_sd->sacl->revision = SECURITY_ACL_REVISION_ADS;
 303         }
 304
 305         sddl_sd = sddl_encode(mem_ctx, final_sd, domain_sid);
 306         DEBUG(10, ("Object %s created with desriptor %s\n\n", ldb_dn_get_linearized(dn), sddl_sd));
 307
 308         linear_sd = talloc(mem_ctx, DATA_BLOB);
 309         if (!linear_sd) {
 310                 return NULL;
 311         }
 312
 313         ndr_err = ndr_push_struct_blob(linear_sd, mem_ctx,
 314                                        final_sd,
 315                                        (ndr_push_flags_fn_t)ndr_push_security_descriptor);
 316         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 317                 return NULL;
 318         }
 319
 320         return linear_sd;
 321 }
 322
 323 static DATA_BLOB *descr_get_descriptor_to_show(struct ldb_module *module,
 324                                                TALLOC_CTX *mem_ctx,
 325                                                struct ldb_val *sd,
 326                                                uint32_t sd_flags)
 327 {
 328         struct security_descriptor *old_sd, *final_sd;
 329         DATA_BLOB *linear_sd;
 330         enum ndr_err_code ndr_err;
 331
 332         old_sd = talloc(mem_ctx, struct security_descriptor);
 333         if (!old_sd) {
 334                 return NULL;
 335         }
 336         ndr_err = ndr_pull_struct_blob(sd, old_sd,
 337                                        old_sd,
 338                                        (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 339
 340         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 341                 talloc_free(old_sd);
 342                 return NULL;
 343         }
 344
 345         final_sd = descr_handle_sd_flags(mem_ctx, old_sd, NULL, sd_flags);
 346
 347         if (!final_sd) {
 348                 return NULL;
 349         }
 350
 351         linear_sd = talloc(mem_ctx, DATA_BLOB);
 352         if (!linear_sd) {
 353                 return NULL;
 354         }
 355
 356         ndr_err = ndr_push_struct_blob(linear_sd, mem_ctx,
 357                                        final_sd,
 358                                        (ndr_push_flags_fn_t)ndr_push_security_descriptor);
 359         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 360                 return NULL;
 361         }
 362
 363         return linear_sd;
 364 }
 365
 366 static struct descriptor_context *descriptor_init_context(struct ldb_module *module,
 367                                                           struct ldb_request *req)
 368 {
 369         struct ldb_context *ldb;
 370         struct descriptor_context *ac;
 371
 372         ldb = ldb_module_get_ctx(module);
 373
 374         ac = talloc_zero(req, struct descriptor_context);
 375         if (ac == NULL) {
 376                 ldb_set_errstring(ldb, "Out of Memory");
 377                 return NULL;
 378         }
 379
 380         ac->module = module;
 381         ac->req = req;
 382         return ac;
 383 }
 384
 385 static int descriptor_search_callback(struct ldb_request *req, struct ldb_reply *ares)
 386 {
 387         struct descriptor_context *ac;
 388         struct ldb_control *sd_control;
 389         struct ldb_val *sd_val = NULL;
 390         struct ldb_message_element *sd_el;
 391         DATA_BLOB *show_sd;
 392         int ret;
 393         uint32_t sd_flags = 0;
 394
 395         ac = talloc_get_type(req->context, struct descriptor_context);
 396
 397         if (!ares) {
 398                 ret = LDB_ERR_OPERATIONS_ERROR;
 399                 goto fail;
 400         }
 401         if (ares->error != LDB_SUCCESS) {
 402                 return ldb_module_done(ac->req, ares->controls,
 403                                         ares->response, ares->error);
 404         }
 405
 406         sd_control = ldb_request_get_control(ac->req, LDB_CONTROL_SD_FLAGS_OID);
 407         if (sd_control) {
 408                 struct ldb_sd_flags_control *sdctr = (struct ldb_sd_flags_control *)sd_control->data;
 409                 sd_flags = sdctr->secinfo_flags;
 410                 /* we only care for the last 4 bits */
 411                 sd_flags = sd_flags & 0x0000000F;
 412                 if (sd_flags == 0) {
 413                         /* MS-ADTS 3.1.1.3.4.1.11 says that no bits
 414                            equals all 4 bits */
 415                         sd_flags = 0xF;
 416                 }
 417         }
 418
 419         switch (ares->type) {
 420         case LDB_REPLY_ENTRY:
 421                 if (sd_flags != 0) {
 422                         sd_el = ldb_msg_find_element(ares->message, "nTSecurityDescriptor");
 423                         if (sd_el) {
 424                                 sd_val = sd_el->values;
 425                         }
 426                 }
 427                 if (sd_val) {
 428                         show_sd = descr_get_descriptor_to_show(ac->module, ac->req,
 429                                                                sd_val, sd_flags);
 430                         if (!show_sd) {
 431                                 ret = LDB_ERR_OPERATIONS_ERROR;
 432                                 goto fail;
 433                         }
 434                         ldb_msg_remove_attr(ares->message, "nTSecurityDescriptor");
 435                         ret = ldb_msg_add_steal_value(ares->message, "nTSecurityDescriptor", show_sd);
 436                         if (ret != LDB_SUCCESS) {
 437                                 goto fail;
 438                         }
 439                 }
 440                 return ldb_module_send_entry(ac->req, ares->message, ares->controls);
 441
 442         case LDB_REPLY_REFERRAL:
 443                 return ldb_module_send_referral(ac->req, ares->referral);
 444
 445         case LDB_REPLY_DONE:
 446                 return ldb_module_done(ac->req, ares->controls,
 447                                         ares->response, ares->error);
 448         }
 449
 450 fail:
 451         talloc_free(ares);
 452         return ldb_module_done(ac->req, NULL, NULL, ret);
 453 }
 454
 455 static int descriptor_add(struct ldb_module *module, struct ldb_request *req)
 456 {
 457         struct ldb_context *ldb;
 458         struct ldb_request *add_req;
 459         struct ldb_message *msg;
 460         struct ldb_result *parent_res;
 461         const struct ldb_val *parent_sd = NULL;
 462         const struct ldb_val *user_sd;
 463         struct ldb_dn *parent_dn, *dn, *nc_root;
 464         struct ldb_message_element *objectclass_element, *sd_element;
 465         int ret;
 466         const struct dsdb_schema *schema;
 467         DATA_BLOB *sd;
 468         const struct dsdb_class *objectclass;
 469         static const char * const parent_attrs[] = { "nTSecurityDescriptor", NULL };
 470         uint32_t instanceType;
 471         bool isNC = false;
 472
 473         ldb = ldb_module_get_ctx(module);
 474         dn = req->op.add.message->dn;
 475         user_sd = ldb_msg_find_ldb_val(req->op.add.message, "nTSecurityDescriptor");
 476         sd_element = ldb_msg_find_element(req->op.add.message, "nTSecurityDescriptor");
 477         /* nTSecurityDescriptor without a value is an error, letting through so it is handled */
 478         if (user_sd == NULL && sd_element) {
 479                 return ldb_next_request(module, req);
 480         }
 481
 482         ldb_debug(ldb, LDB_DEBUG_TRACE,"descriptor_add: %s\n", ldb_dn_get_linearized(dn));
 483
 484         /* do not manipulate our control entries */
 485         if (ldb_dn_is_special(dn)) {
 486                 return ldb_next_request(module, req);
 487         }
 488
 489         instanceType = ldb_msg_find_attr_as_uint(req->op.add.message, "instanceType", 0);
 490
 491         if (instanceType & INSTANCE_TYPE_IS_NC_HEAD) {
 492                 isNC = true;
 493         }
 494
 495         if (!isNC) {
 496                 ret = dsdb_find_nc_root(ldb, req, dn, &nc_root);
 497                 if (ret != LDB_SUCCESS) {
 498                         ldb_debug(ldb, LDB_DEBUG_TRACE,"descriptor_add: Could not find NC root for %s\n",
 499                                 ldb_dn_get_linearized(dn));
 500                         return ret;
 501                 }
 502
 503                 if (ldb_dn_compare(dn, nc_root) == 0) {
 504                         DEBUG(0, ("Found DN %s being a NC by the old method\n", ldb_dn_get_linearized(dn)));
 505                         isNC = true;
 506                 }
 507         }
 508
 509         if (isNC) {
 510                 DEBUG(2, ("DN: %s is a NC\n", ldb_dn_get_linearized(dn)));
 511         }
 512         if (!isNC) {
 513                 /* if the object has a parent, retrieve its SD to
 514                  * use for calculation. Unfortunately we do not yet have
 515                  * instanceType, so we use dsdb_find_nc_root. */
 516
 517                 parent_dn = ldb_dn_get_parent(req, dn);
 518                 if (parent_dn == NULL) {
 519                         return ldb_oom(ldb);
 520                 }
 521
 522                 /* we aren't any NC */
 523                 ret = dsdb_module_search_dn(module, req, &parent_res, parent_dn,
 524                                             parent_attrs,
 525                                             DSDB_FLAG_NEXT_MODULE,
 526                                             req);
 527                 if (ret != LDB_SUCCESS) {
 528                         ldb_debug(ldb, LDB_DEBUG_TRACE,"descriptor_add: Could not find SD for %s\n",
 529                                   ldb_dn_get_linearized(parent_dn));
 530                         return ret;
 531                 }
 532                 if (parent_res->count != 1) {
 533                         return ldb_operr(ldb);
 534                 }
 535                 parent_sd = ldb_msg_find_ldb_val(parent_res->msgs[0], "nTSecurityDescriptor");
 536         }
 537
 538         schema = dsdb_get_schema(ldb, req);
 539
 540         objectclass_element = ldb_msg_find_element(req->op.add.message, "objectClass");
 541         if (objectclass_element == NULL) {
 542                 return ldb_operr(ldb);
 543         }
 544
 545         objectclass = get_last_structural_class(schema, objectclass_element, req);
 546         if (objectclass == NULL) {
 547                 return ldb_operr(ldb);
 548         }
 549
 550         sd = get_new_descriptor(module, dn, req,
 551                                 objectclass, parent_sd,
 552                                 user_sd, NULL, 0);
 553         msg = ldb_msg_copy_shallow(req, req->op.add.message);
 554         if (sd != NULL) {
 555                 if (sd_element != NULL) {
 556                         sd_element->values[0] = *sd;
 557                 } else {
 558                         ret = ldb_msg_add_steal_value(msg,
 559                                                       "nTSecurityDescriptor",
 560                                                       sd);
 561                         if (ret != LDB_SUCCESS) {
 562                                 return ret;
 563                         }
 564                 }
 565         }
 566
 567         ret = ldb_build_add_req(&add_req, ldb, req,
 568                                 msg,
 569                                 req->controls,
 570                                 req, dsdb_next_callback,
 571                                 req);
 572         LDB_REQ_SET_LOCATION(add_req);
 573         if (ret != LDB_SUCCESS) {
 574                 return ldb_error(ldb, ret,
 575                                  "descriptor_add: Error creating new add request.");
 576         }
 577
 578         return ldb_next_request(module, add_req);
 579 }
 580
 581 static int descriptor_modify(struct ldb_module *module, struct ldb_request *req)
 582 {
 583         struct ldb_context *ldb;
 584         struct ldb_control *sd_recalculate_control, *sd_flags_control;
 585         struct ldb_request *mod_req;
 586         struct ldb_message *msg;
 587         struct ldb_result *current_res, *parent_res;
 588         const struct ldb_val *old_sd = NULL;
 589         const struct ldb_val *parent_sd = NULL;
 590         const struct ldb_val *user_sd;
 591         struct ldb_dn *parent_dn, *dn;
 592         struct ldb_message_element *objectclass_element;
 593         int ret;
 594         uint32_t instanceType, sd_flags = 0;
 595         const struct dsdb_schema *schema;
 596         DATA_BLOB *sd;
 597         const struct dsdb_class *objectclass;
 598         static const char * const parent_attrs[] = { "nTSecurityDescriptor", NULL };
 599         static const char * const current_attrs[] = { "nTSecurityDescriptor",
 600                                                       "instanceType",
 601                                                       "objectClass", NULL };
 602         ldb = ldb_module_get_ctx(module);
 603         dn = req->op.mod.message->dn;
 604         user_sd = ldb_msg_find_ldb_val(req->op.mod.message, "nTSecurityDescriptor");
 605         /* This control forces the recalculation of the SD also when
 606          * no modification is performed. */
 607         sd_recalculate_control = ldb_request_get_control(req,
 608                                              LDB_CONTROL_RECALCULATE_SD_OID);
 609         if (!user_sd && !sd_recalculate_control) {
 610                 return ldb_next_request(module, req);
 611         }
 612
 613         ldb_debug(ldb, LDB_DEBUG_TRACE,"descriptor_modify: %s\n", ldb_dn_get_linearized(dn));
 614
 615         /* do not manipulate our control entries */
 616         if (ldb_dn_is_special(dn)) {
 617                 return ldb_next_request(module, req);
 618         }
 619
 620         ret = dsdb_module_search_dn(module, req, &current_res, dn,
 621                                     current_attrs,
 622                                     DSDB_FLAG_NEXT_MODULE,
 623                                     req);
 624         if (ret != LDB_SUCCESS) {
 625                 ldb_debug(ldb, LDB_DEBUG_ERROR,"descriptor_modify: Could not find %s\n",
 626                           ldb_dn_get_linearized(dn));
 627                 return ret;
 628         }
 629
 630         instanceType = ldb_msg_find_attr_as_uint(current_res->msgs[0],
 631                                                  "instanceType", 0);
 632         /* if the object has a parent, retrieve its SD to
 633          * use for calculation */
 634         if (!ldb_dn_is_null(current_res->msgs[0]->dn) &&
 635             !(instanceType & INSTANCE_TYPE_IS_NC_HEAD)) {
 636                 parent_dn = ldb_dn_get_parent(req, dn);
 637                 if (parent_dn == NULL) {
 638                         return ldb_oom(ldb);
 639                 }
 640                 ret = dsdb_module_search_dn(module, req, &parent_res, parent_dn,
 641                                             parent_attrs,
 642                                             DSDB_FLAG_NEXT_MODULE,
 643                                             req);
 644                 if (ret != LDB_SUCCESS) {
 645                         ldb_debug(ldb, LDB_DEBUG_ERROR, "descriptor_modify: Could not find SD for %s\n",
 646                                   ldb_dn_get_linearized(parent_dn));
 647                         return ret;
 648                 }
 649                 if (parent_res->count != 1) {
 650                         return ldb_operr(ldb);
 651                 }
 652                 parent_sd = ldb_msg_find_ldb_val(parent_res->msgs[0], "nTSecurityDescriptor");
 653         }
 654         sd_flags_control = ldb_request_get_control(req, LDB_CONTROL_SD_FLAGS_OID);
 655
 656         schema = dsdb_get_schema(ldb, req);
 657
 658         objectclass_element = ldb_msg_find_element(current_res->msgs[0], "objectClass");
 659         if (objectclass_element == NULL) {
 660                 return ldb_operr(ldb);
 661         }
 662
 663         objectclass = get_last_structural_class(schema, objectclass_element, req);
 664         if (objectclass == NULL) {
 665                 return ldb_operr(ldb);
 666         }
 667
 668         if (sd_flags_control) {
 669                 struct ldb_sd_flags_control *sdctr = (struct ldb_sd_flags_control *)sd_flags_control->data;
 670                 sd_flags = sdctr->secinfo_flags;
 671                 /* we only care for the last 4 bits */
 672                 sd_flags = sd_flags & 0x0000000F;
 673         }
 674         if (sd_flags != 0) {
 675                 old_sd = ldb_msg_find_ldb_val(current_res->msgs[0], "nTSecurityDescriptor");
 676         }
 677
 678         sd = get_new_descriptor(module, dn, req,
 679                                 objectclass, parent_sd,
 680                                 user_sd, old_sd, sd_flags);
 681         msg = ldb_msg_copy_shallow(req, req->op.mod.message);
 682         if (sd != NULL) {
 683                 struct ldb_message_element *sd_element;
 684                 if (user_sd != NULL) {
 685                         sd_element = ldb_msg_find_element(msg,
 686                                                           "nTSecurityDescriptor");
 687                         sd_element->values[0] = *sd;
 688                 } else if (sd_recalculate_control != NULL) {
 689                         /* In this branch we really do force the recalculation
 690                          * of the SD */
 691                         ldb_msg_remove_attr(msg, "nTSecurityDescriptor");
 692
 693                         ret = ldb_msg_add_steal_value(msg,
 694                                                       "nTSecurityDescriptor",
 695                                                       sd);
 696                         if (ret != LDB_SUCCESS) {
 697                                 return ldb_error(ldb, ret,
 698                                          "descriptor_modify: Could not replace SD value in message.");
 699                         }
 700                         sd_element = ldb_msg_find_element(msg,
 701                                                           "nTSecurityDescriptor");
 702                         sd_element->flags = LDB_FLAG_MOD_REPLACE;
 703                 }
 704         }
 705
 706         /* mark the controls as non-critical since we've handled them */
 707         if (sd_flags_control != NULL) {
 708                 sd_flags_control->critical = 0;
 709         }
 710         if (sd_recalculate_control != NULL) {
 711                 sd_recalculate_control->critical = 0;
 712         }
 713
 714         ret = ldb_build_mod_req(&mod_req, ldb, req,
 715                                 msg,
 716                                 req->controls,
 717                                 req,
 718                                 dsdb_next_callback,
 719                                 req);
 720         LDB_REQ_SET_LOCATION(mod_req);
 721         if (ret != LDB_SUCCESS) {
 722                 return ret;
 723         }
 724
 725         return ldb_next_request(module, mod_req);
 726 }
 727
 728 static int descriptor_search(struct ldb_module *module, struct ldb_request *req)
 729 {
 730         int ret;
 731         struct ldb_context *ldb;
 732         struct ldb_control *sd_control;
 733         struct ldb_request *down_req;
 734         struct descriptor_context *ac;
 735
 736         sd_control = ldb_request_get_control(req, LDB_CONTROL_SD_FLAGS_OID);
 737         if (!sd_control) {
 738                 return ldb_next_request(module, req);
 739         }
 740
 741         ldb = ldb_module_get_ctx(module);
 742         ac = descriptor_init_context(module, req);
 743         if (ac == NULL) {
 744                 return ldb_operr(ldb);
 745         }
 746
 747         ret = ldb_build_search_req_ex(&down_req, ldb, ac,
 748                                       req->op.search.base,
 749                                       req->op.search.scope,
 750                                       req->op.search.tree,
 751                                       req->op.search.attrs,
 752                                       req->controls,
 753                                       ac, descriptor_search_callback,
 754                                       ac->req);
 755         LDB_REQ_SET_LOCATION(down_req);
 756         if (ret != LDB_SUCCESS) {
 757                 return ret;
 758         }
 759         /* mark it as handled */
 760         if (sd_control) {
 761                 sd_control->critical = 0;
 762         }
 763
 764         return ldb_next_request(ac->module, down_req);
 765 }
 766 /* TODO */
 767 static int descriptor_rename(struct ldb_module *module, struct ldb_request *req)
 768 {
 769         struct ldb_context *ldb = ldb_module_get_ctx(module);
 770         ldb_debug(ldb, LDB_DEBUG_TRACE,"descriptor_rename: %s\n", ldb_dn_get_linearized(req->op.rename.olddn));
 771
 772         /* do not manipulate our control entries */
 773         if (ldb_dn_is_special(req->op.rename.olddn)) {
 774                 return ldb_next_request(module, req);
 775         }
 776
 777         return ldb_next_request(module, req);
 778 }
 779
 780 static int descriptor_init(struct ldb_module *module)
 781 {
 782         int ret = ldb_mod_register_control(module, LDB_CONTROL_SD_FLAGS_OID);
 783         struct ldb_context *ldb = ldb_module_get_ctx(module);
 784         if (ret != LDB_SUCCESS) {
 785                 ldb_debug(ldb, LDB_DEBUG_ERROR,
 786                         "descriptor: Unable to register control with rootdse!\n");
 787                 return ldb_operr(ldb);
 788         }
 789         return ldb_next_init(module);
 790 }
 791
 792
 793 static const struct ldb_module_ops ldb_descriptor_module_ops = {
 794         .name          = "descriptor",
 795         .search        = descriptor_search,
 796         .add           = descriptor_add,
 797         .modify        = descriptor_modify,
 798         .rename        = descriptor_rename,
 799         .init_context  = descriptor_init
 800 };
 801
 802 int ldb_descriptor_module_init(const char *version)
 803 {
 804         LDB_MODULE_CHECK_VERSION(version);
 805         return ldb_register_module(&ldb_descriptor_module_ops);
 806 }