source4/dsdb/samdb/ldb_modules/extended_dn_in.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce 2005-2008
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007-2008
   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 interprets DNs of the form <SID=S-1-2-4456> into normal DNs.
  27  *
  28  *  Authors: Simo Sorce
  29  *           Andrew Bartlett
  30  */
  31
  32 #include "includes.h"
  33 #include <ldb.h>
  34 #include <ldb_errors.h>
  35 #include <ldb_module.h>
  36
  37 /*
  38   TODO: if relax is not set then we need to reject the fancy RMD_* and
  39   DELETED extended DN codes
  40  */
  41
  42 /* search */
  43 struct extended_search_context {
  44         struct ldb_module *module;
  45         struct ldb_request *req;
  46         struct ldb_dn *basedn;
  47         char *wellknown_object;
  48         int extended_type;
  49 };
  50
  51 /* An extra layer of indirection because LDB does not allow the original request to be altered */
  52
  53 static int extended_final_callback(struct ldb_request *req, struct ldb_reply *ares)
  54 {
  55         int ret = LDB_ERR_OPERATIONS_ERROR;
  56         struct extended_search_context *ac;
  57         ac = talloc_get_type(req->context, struct extended_search_context);
  58
  59         if (ares->error != LDB_SUCCESS) {
  60                 ret = ldb_module_done(ac->req, ares->controls,
  61                                       ares->response, ares->error);
  62         } else {
  63                 switch (ares->type) {
  64                 case LDB_REPLY_ENTRY:
  65
  66                         ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
  67                         break;
  68                 case LDB_REPLY_REFERRAL:
  69
  70                         ret = ldb_module_send_referral(ac->req, ares->referral);
  71                         break;
  72                 case LDB_REPLY_DONE:
  73
  74                         ret = ldb_module_done(ac->req, ares->controls,
  75                                               ares->response, ares->error);
  76                         break;
  77                 }
  78         }
  79         return ret;
  80 }
  81
  82 static int extended_base_callback(struct ldb_request *req, struct ldb_reply *ares)
  83 {
  84         struct extended_search_context *ac;
  85         struct ldb_request *down_req;
  86         struct ldb_message_element *el;
  87         int ret;
  88         unsigned int i;
  89         size_t wkn_len = 0;
  90         char *valstr = NULL;
  91         const char *found = NULL;
  92
  93         ac = talloc_get_type(req->context, struct extended_search_context);
  94
  95         if (!ares) {
  96                 return ldb_module_done(ac->req, NULL, NULL,
  97                                         LDB_ERR_OPERATIONS_ERROR);
  98         }
  99         if (ares->error != LDB_SUCCESS) {
 100                 return ldb_module_done(ac->req, ares->controls,
 101                                         ares->response, ares->error);
 102         }
 103
 104         switch (ares->type) {
 105         case LDB_REPLY_ENTRY:
 106                 if (ac->basedn) {
 107                         /* we have more than one match! This can
 108                            happen as S-1-5-17 appears twice in a
 109                            normal provision. We need to return
 110                            NO_SUCH_OBJECT */
 111                         const char *str = talloc_asprintf(req, "Duplicate base-DN matches found for '%s'",
 112                                                           ldb_dn_get_extended_linearized(req, ac->req->op.search.base, 1));
 113                         ldb_set_errstring(ldb_module_get_ctx(ac->module), str);
 114                         return ldb_module_done(ac->req, NULL, NULL,
 115                                                LDB_ERR_NO_SUCH_OBJECT);
 116                 }
 117
 118                 if (!ac->wellknown_object) {
 119                         ac->basedn = talloc_steal(ac, ares->message->dn);
 120                         break;
 121                 }
 122
 123                 wkn_len = strlen(ac->wellknown_object);
 124
 125                 el = ldb_msg_find_element(ares->message, "wellKnownObjects");
 126                 if (!el) {
 127                         ac->basedn = NULL;
 128                         break;
 129                 }
 130
 131                 for (i=0; i < el->num_values; i++) {
 132                         valstr = talloc_strndup(ac,
 133                                                 (const char *)el->values[i].data,
 134                                                 el->values[i].length);
 135                         if (!valstr) {
 136                                 ldb_oom(ldb_module_get_ctx(ac->module));
 137                                 return ldb_module_done(ac->req, NULL, NULL,
 138                                                        LDB_ERR_OPERATIONS_ERROR);
 139                         }
 140
 141                         if (strncasecmp(valstr, ac->wellknown_object, wkn_len) != 0) {
 142                                 talloc_free(valstr);
 143                                 continue;
 144                         }
 145
 146                         found = &valstr[wkn_len];
 147                         break;
 148                 }
 149
 150                 if (!found) {
 151                         break;
 152                 }
 153
 154                 ac->basedn = ldb_dn_new(ac, ldb_module_get_ctx(ac->module), found);
 155                 talloc_free(valstr);
 156                 if (!ac->basedn) {
 157                         ldb_oom(ldb_module_get_ctx(ac->module));
 158                         return ldb_module_done(ac->req, NULL, NULL,
 159                                                LDB_ERR_OPERATIONS_ERROR);
 160                 }
 161
 162                 break;
 163
 164         case LDB_REPLY_REFERRAL:
 165                 break;
 166
 167         case LDB_REPLY_DONE:
 168
 169                 if (!ac->basedn) {
 170                         const char *str = talloc_asprintf(req, "Base-DN '%s' not found",
 171                                                           ldb_dn_get_extended_linearized(req, ac->req->op.search.base, 1));
 172                         ldb_set_errstring(ldb_module_get_ctx(ac->module), str);
 173                         return ldb_module_done(ac->req, NULL, NULL,
 174                                                LDB_ERR_NO_SUCH_OBJECT);
 175                 }
 176
 177                 switch (ac->req->operation) {
 178                 case LDB_SEARCH:
 179                         ret = ldb_build_search_req_ex(&down_req,
 180                                                       ldb_module_get_ctx(ac->module), ac->req,
 181                                                       ac->basedn,
 182                                                       ac->req->op.search.scope,
 183                                                       ac->req->op.search.tree,
 184                                                       ac->req->op.search.attrs,
 185                                                       ac->req->controls,
 186                                                       ac, extended_final_callback,
 187                                                       ac->req);
 188                         LDB_REQ_SET_LOCATION(down_req);
 189                         break;
 190                 case LDB_ADD:
 191                 {
 192                         struct ldb_message *add_msg = ldb_msg_copy_shallow(ac, ac->req->op.add.message);
 193                         if (!add_msg) {
 194                                 ldb_oom(ldb_module_get_ctx(ac->module));
 195                                 return ldb_module_done(ac->req, NULL, NULL,
 196                                                        LDB_ERR_OPERATIONS_ERROR);
 197                         }
 198
 199                         add_msg->dn = ac->basedn;
 200
 201                         ret = ldb_build_add_req(&down_req,
 202                                                 ldb_module_get_ctx(ac->module), ac->req,
 203                                                 add_msg,
 204                                                 ac->req->controls,
 205                                                 ac, extended_final_callback,
 206                                                 ac->req);
 207                         LDB_REQ_SET_LOCATION(down_req);
 208                         break;
 209                 }
 210                 case LDB_MODIFY:
 211                 {
 212                         struct ldb_message *mod_msg = ldb_msg_copy_shallow(ac, ac->req->op.mod.message);
 213                         if (!mod_msg) {
 214                                 ldb_oom(ldb_module_get_ctx(ac->module));
 215                                 return ldb_module_done(ac->req, NULL, NULL,
 216                                                        LDB_ERR_OPERATIONS_ERROR);
 217                         }
 218
 219                         mod_msg->dn = ac->basedn;
 220
 221                         ret = ldb_build_mod_req(&down_req,
 222                                                 ldb_module_get_ctx(ac->module), ac->req,
 223                                                 mod_msg,
 224                                                 ac->req->controls,
 225                                                 ac, extended_final_callback,
 226                                                 ac->req);
 227                         LDB_REQ_SET_LOCATION(down_req);
 228                         break;
 229                 }
 230                 case LDB_DELETE:
 231                         ret = ldb_build_del_req(&down_req,
 232                                                 ldb_module_get_ctx(ac->module), ac->req,
 233                                                 ac->basedn,
 234                                                 ac->req->controls,
 235                                                 ac, extended_final_callback,
 236                                                 ac->req);
 237                         LDB_REQ_SET_LOCATION(down_req);
 238                         break;
 239                 case LDB_RENAME:
 240                         ret = ldb_build_rename_req(&down_req,
 241                                                    ldb_module_get_ctx(ac->module), ac->req,
 242                                                    ac->basedn,
 243                                                    ac->req->op.rename.newdn,
 244                                                    ac->req->controls,
 245                                                    ac, extended_final_callback,
 246                                                    ac->req);
 247                         LDB_REQ_SET_LOCATION(down_req);
 248                         break;
 249                 default:
 250                         return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
 251                 }
 252
 253                 if (ret != LDB_SUCCESS) {
 254                         return ldb_module_done(ac->req, NULL, NULL, ret);
 255                 }
 256
 257                 return ldb_next_request(ac->module, down_req);
 258         }
 259         talloc_free(ares);
 260         return LDB_SUCCESS;
 261 }
 262
 263 static int extended_dn_in_fix(struct ldb_module *module, struct ldb_request *req, struct ldb_dn *dn)
 264 {
 265         struct extended_search_context *ac;
 266         struct ldb_request *down_req;
 267         int ret;
 268         struct ldb_dn *base_dn = NULL;
 269         enum ldb_scope base_dn_scope = LDB_SCOPE_BASE;
 270         const char *base_dn_filter = NULL;
 271         const char * const *base_dn_attrs = NULL;
 272         char *wellknown_object = NULL;
 273         static const char *no_attr[] = {
 274                 NULL
 275         };
 276         static const char *wkattr[] = {
 277                 "wellKnownObjects",
 278                 NULL
 279         };
 280         bool all_partitions = false;
 281
 282         if (!ldb_dn_has_extended(dn)) {
 283                 /* Move along there isn't anything to see here */
 284                 return ldb_next_request(module, req);
 285         } else {
 286                 /* It looks like we need to map the DN */
 287                 const struct ldb_val *sid_val, *guid_val, *wkguid_val;
 288                 int num_components = ldb_dn_get_comp_num(dn);
 289                 int num_ex_components = ldb_dn_get_extended_comp_num(dn);
 290
 291                 /*
 292                   windows ldap searchs don't allow a baseDN with more
 293                   than one extended component, or an extended
 294                   component and a string DN
 295
 296                   We only enforce this over ldap, not for internal
 297                   use, as there are just too many places where we
 298                   internally want to use a DN that has come from a
 299                   search with extended DN enabled, or comes from a DRS
 300                   naming context.
 301
 302                   Enforcing this would also make debugging samba much
 303                   harder, as we'd need to use ldb_dn_minimise() in a
 304                   lot of places, and that would lose the DN string
 305                   which is so useful for working out what a request is
 306                   for
 307                  */
 308                 if ((num_components != 0 || num_ex_components != 1) &&
 309                     ldb_req_is_untrusted(req)) {
 310                         return ldb_error(ldb_module_get_ctx(module),
 311                                          LDB_ERR_INVALID_DN_SYNTAX, "invalid number of DN components");
 312                 }
 313
 314                 sid_val = ldb_dn_get_extended_component(dn, "SID");
 315                 guid_val = ldb_dn_get_extended_component(dn, "GUID");
 316                 wkguid_val = ldb_dn_get_extended_component(dn, "WKGUID");
 317
 318                 /*
 319                   prioritise the GUID - we have had instances of
 320                   duplicate SIDs in the database in the
 321                   ForeignSecurityPrinciples due to provision errors
 322                  */
 323                 if (guid_val) {
 324                         all_partitions = true;
 325                         base_dn = ldb_get_default_basedn(ldb_module_get_ctx(module));
 326                         base_dn_filter = talloc_asprintf(req, "(objectGUID=%s)",
 327                                                          ldb_binary_encode(req, *guid_val));
 328                         if (!base_dn_filter) {
 329                                 return ldb_oom(ldb_module_get_ctx(module));
 330                         }
 331                         base_dn_scope = LDB_SCOPE_SUBTREE;
 332                         base_dn_attrs = no_attr;
 333
 334                 } else if (sid_val) {
 335                         all_partitions = true;
 336                         base_dn = ldb_get_default_basedn(ldb_module_get_ctx(module));
 337                         base_dn_filter = talloc_asprintf(req, "(objectSid=%s)",
 338                                                          ldb_binary_encode(req, *sid_val));
 339                         if (!base_dn_filter) {
 340                                 return ldb_oom(ldb_module_get_ctx(module));
 341                         }
 342                         base_dn_scope = LDB_SCOPE_SUBTREE;
 343                         base_dn_attrs = no_attr;
 344
 345                 } else if (wkguid_val) {
 346                         char *wkguid_dup;
 347                         char *tail_str;
 348                         char *p;
 349
 350                         wkguid_dup = talloc_strndup(req, (char *)wkguid_val->data, wkguid_val->length);
 351
 352                         p = strchr(wkguid_dup, ',');
 353                         if (!p) {
 354                                 return ldb_error(ldb_module_get_ctx(module), LDB_ERR_INVALID_DN_SYNTAX,
 355                                                  "Invalid WKGUID format");
 356                         }
 357
 358                         p[0] = '\0';
 359                         p++;
 360
 361                         wellknown_object = talloc_asprintf(req, "B:32:%s:", wkguid_dup);
 362                         if (!wellknown_object) {
 363                                 return ldb_oom(ldb_module_get_ctx(module));
 364                         }
 365
 366                         tail_str = p;
 367
 368                         base_dn = ldb_dn_new(req, ldb_module_get_ctx(module), tail_str);
 369                         talloc_free(wkguid_dup);
 370                         if (!base_dn) {
 371                                 return ldb_oom(ldb_module_get_ctx(module));
 372                         }
 373                         base_dn_filter = talloc_strdup(req, "(objectClass=*)");
 374                         if (!base_dn_filter) {
 375                                 return ldb_oom(ldb_module_get_ctx(module));
 376                         }
 377                         base_dn_scope = LDB_SCOPE_BASE;
 378                         base_dn_attrs = wkattr;
 379                 } else {
 380                         return ldb_error(ldb_module_get_ctx(module), LDB_ERR_INVALID_DN_SYNTAX,
 381                                          "Invalid extended DN component");
 382                 }
 383
 384                 ac = talloc_zero(req, struct extended_search_context);
 385                 if (ac == NULL) {
 386                         return ldb_oom(ldb_module_get_ctx(module));
 387                 }
 388
 389                 ac->module = module;
 390                 ac->req = req;
 391                 ac->basedn = NULL;  /* Filled in if the search finds the DN by SID/GUID etc */
 392                 ac->wellknown_object = wellknown_object;
 393
 394                 /* If the base DN was an extended DN (perhaps a well known
 395                  * GUID) then search for that, so we can proceed with the original operation */
 396
 397                 ret = ldb_build_search_req(&down_req,
 398                                            ldb_module_get_ctx(module), ac,
 399                                            base_dn,
 400                                            base_dn_scope,
 401                                            base_dn_filter,
 402                                            base_dn_attrs,
 403                                            req->controls,
 404                                            ac, extended_base_callback,
 405                                            req);
 406                 LDB_REQ_SET_LOCATION(down_req);
 407                 if (ret != LDB_SUCCESS) {
 408                         return ldb_operr(ldb_module_get_ctx(module));
 409                 }
 410
 411                 if (all_partitions) {
 412                         struct ldb_search_options_control *control;
 413                         control = talloc(down_req, struct ldb_search_options_control);
 414                         control->search_options = 2;
 415                         ret = ldb_request_replace_control(down_req,
 416                                                       LDB_CONTROL_SEARCH_OPTIONS_OID,
 417                                                       true, control);
 418                         if (ret != LDB_SUCCESS) {
 419                                 ldb_oom(ldb_module_get_ctx(module));
 420                                 return ret;
 421                         }
 422                 }
 423
 424                 /* perform the search */
 425                 return ldb_next_request(module, down_req);
 426         }
 427 }
 428
 429 static int extended_dn_in_search(struct ldb_module *module, struct ldb_request *req)
 430 {
 431         return extended_dn_in_fix(module, req, req->op.search.base);
 432 }
 433
 434 static int extended_dn_in_modify(struct ldb_module *module, struct ldb_request *req)
 435 {
 436         return extended_dn_in_fix(module, req, req->op.mod.message->dn);
 437 }
 438
 439 static int extended_dn_in_del(struct ldb_module *module, struct ldb_request *req)
 440 {
 441         return extended_dn_in_fix(module, req, req->op.del.dn);
 442 }
 443
 444 static int extended_dn_in_rename(struct ldb_module *module, struct ldb_request *req)
 445 {
 446         return extended_dn_in_fix(module, req, req->op.rename.olddn);
 447 }
 448
 449 static const struct ldb_module_ops ldb_extended_dn_in_module_ops = {
 450         .name              = "extended_dn_in",
 451         .search            = extended_dn_in_search,
 452         .modify            = extended_dn_in_modify,
 453         .del               = extended_dn_in_del,
 454         .rename            = extended_dn_in_rename,
 455 };
 456
 457 int ldb_extended_dn_in_module_init(const char *version)
 458 {
 459         LDB_MODULE_CHECK_VERSION(version);
 460         return ldb_register_module(&ldb_extended_dn_in_module_ops);
 461 }