s4:dsdb: split extended_dn into extended_dn_in, extended_dn_out and extended_dn_store.

By splitting the module, the extended_dn_in and extended_dn_store
moudles can use extended_dn_out to actually get the extended DN.  This
avoids code duplication.

The extended_dn_out module also contains a client implementation of
the OpenLDAP dereference control (draft-masarati-ldap-deref-00).

This also introduces a new control
'DSDB_CONTROL_DN_STORAGE_FORMAT_OID' to ask the extended_dn_out module
to return whatever the 'storage format' is.  This allows us to work
with both OpenLDAP (which performs a dereference at run time) and LDB
(which stores the GUID and SID on disk).

Signed-off-by: Stefan Metzmacher <metze@samba.org>

6 files changed, 1515 insertions, 672 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/config.mk b/source4/dsdb/samdb/ldb_modules/config.mk
index 1387066256..19375bb923 100644
--- a/source4/dsdb/samdb/ldb_modules/config.mk
+++ b/source4/dsdb/samdb/ldb_modules/config.mk
@@ -171,15 +171,39 @@ INIT_FUNCTION = LDB_MODULE(kludge_acl)
 ldb_kludge_acl_OBJ_FILES = $(dsdbsrcdir)/samdb/ldb_modules/kludge_acl.o
 
 ################################################
-# Start MODULE ldb_extended_dn
-[MODULE::ldb_extended_dn]
+# Start MODULE ldb_extended_dn_in
+[MODULE::ldb_extended_dn_in]
 SUBSYSTEM = LIBLDB
-PRIVATE_DEPENDENCIES = LIBTALLOC LIBEVENTS LIBNDR LIBSECURITY SAMDB
-INIT_FUNCTION = LDB_MODULE(extended_dn)
-# End MODULE ldb_extended_dn
+PRIVATE_DEPENDENCIES = LIBTALLOC LIBEVENTS
+INIT_FUNCTION = LDB_MODULE(extended_dn_in)
+# End MODULE ldb_extended_dn_in
+################################################
+
+ldb_extended_dn_in_OBJ_FILES = $(dsdbsrcdir)/samdb/ldb_modules/extended_dn_in.o
+
+################################################
+# Start MODULE ldb_extended_dn_out
+[MODULE::ldb_extended_dn_out]
+SUBSYSTEM = LIBLDB
+PRIVATE_DEPENDENCIES = LIBTALLOC LIBEVENTS
+INIT_FUNCTION = LDB_MODULE(extended_dn_out_ldb),LDB_MODULE(extended_dn_out_dereference)
+ENABLE = YES
+ALIASES = extended_dn_out_ldb extended_dn_out_dereference
+# End MODULE ldb_extended_dn_out
+################################################
+
+ldb_extended_dn_out_OBJ_FILES = $(dsdbsrcdir)/samdb/ldb_modules/extended_dn_out.o
+
+################################################
+# Start MODULE ldb_extended_dn_store
+[MODULE::ldb_extended_dn_store]
+SUBSYSTEM = LIBLDB
+PRIVATE_DEPENDENCIES = LIBTALLOC LIBEVENTS
+INIT_FUNCTION = LDB_MODULE(extended_dn_store)
+# End MODULE ldb_extended_dn_store
 ################################################
 
-ldb_extended_dn_OBJ_FILES = $(dsdbsrcdir)/samdb/ldb_modules/extended_dn.o
+ldb_extended_dn_store_OBJ_FILES = $(dsdbsrcdir)/samdb/ldb_modules/extended_dn_store.o
 
 ################################################
 # Start MODULE ldb_show_deleted
diff --git a/source4/dsdb/samdb/ldb_modules/extended_dn.c b/source4/dsdb/samdb/ldb_modules/extended_dn.c
deleted file mode 100644
index 48683db456..0000000000
--- a/source4/dsdb/samdb/ldb_modules/extended_dn.c
+++ /dev/null
@@ -1,666 +0,0 @@
-/* 
-   ldb database library
-
-   Copyright (C) Simo Sorce 2005-2008
-
-     ** NOTE! The following LGPL license applies to the ldb
-     ** library. This does NOT imply that all of Samba is released
-     ** under the LGPL
-   
-   This library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 3 of the License, or (at your option) any later version.
-
-   This library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-
-/*
- *  Name: ldb
- *
- *  Component: ldb extended dn control module
- *
- *  Description: this module builds a special dn
- *
- *  Author: Simo Sorce
- */
-
-#include "includes.h"
-#include "ldb/include/ldb.h"
-#include "ldb/include/ldb_errors.h"
-#include "ldb/include/ldb_private.h"
-#include "librpc/gen_ndr/ndr_misc.h"
-#include "dsdb/samdb/samdb.h"
-#include "libcli/security/security.h"
-
-#include <time.h>
-
-static bool is_attr_in_list(const char * const * attrs, const char *attr)
-{
-	int i;
-
-	for (i = 0; attrs[i]; i++) {
-		if (strcasecmp(attrs[i], attr) == 0)
-			return true;
-	}
-
-	return false;
-}
-
-static char **copy_attrs(void *mem_ctx, const char * const * attrs)
-{
-	char **new;
-	int i, num;
-
-	for (num = 0; attrs[num]; num++);
-
-	new = talloc_array(mem_ctx, char *, num + 1);
-	if (!new) return NULL;
-
-	for(i = 0; i < num; i++) {
-		new[i] = talloc_strdup(new, attrs[i]);
-		if (!new[i]) {
-			talloc_free(new);
-			return NULL;
-		}
-	}
-	new[i] = NULL;
-
-	return new;
-}
-
-static bool add_attrs(void *mem_ctx, char ***attrs, const char *attr)
-{
-	char **new;
-	int num;
-
-	for (num = 0; (*attrs)[num]; num++);
-
-	new = talloc_realloc(mem_ctx, *attrs, char *, num + 2);
-	if (!new) return false;
-
-	*attrs = new;
-
-	new[num] = talloc_strdup(new, attr);
-	if (!new[num]) return false;
-
-	new[num + 1] = NULL;
-
-	return true;
-}
-
-static int inject_extended_dn(struct ldb_message *msg,
-				struct ldb_context *ldb,
-				int type,
-				bool remove_guid,
-				bool remove_sid)
-{
-	const struct ldb_val *val;
-	struct GUID guid;
-	struct dom_sid *sid;
-	const DATA_BLOB *guid_blob;
-	const DATA_BLOB *sid_blob;
-	char *object_guid;
-	char *object_sid;
-	char *new_dn;
-
-	guid_blob = ldb_msg_find_ldb_val(msg, "objectGUID");
-	sid_blob = ldb_msg_find_ldb_val(msg, "objectSID");
-
-	if (!guid_blob) {
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	switch (type) {
-		case 0:
-			/* return things in hexadecimal format */
-			if (sid_blob) {
-				const char *lower_guid_hex = strlower_talloc(msg, data_blob_hex_string(msg, guid_blob));
-				const char *lower_sid_hex = strlower_talloc(msg, data_blob_hex_string(msg, sid_blob));
-				if (!lower_guid_hex || !lower_sid_hex) {
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-				new_dn = talloc_asprintf(msg, "<GUID=%s>;<SID=%s>;%s",
-							 lower_guid_hex, 
-							 lower_sid_hex,
-							 ldb_dn_get_linearized(msg->dn));
-			} else {
-				const char *lower_guid_hex = strlower_talloc(msg, data_blob_hex_string(msg, guid_blob));
-				if (!lower_guid_hex) {
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-				new_dn = talloc_asprintf(msg, "<GUID=%s>;%s",
-							 lower_guid_hex, 
-							 ldb_dn_get_linearized(msg->dn));
-			}
-
-			break;
-		case 1:
-			/* retrieve object_guid */
-			guid = samdb_result_guid(msg, "objectGUID");
-			object_guid = GUID_string(msg, &guid);
-			
-			/* retrieve object_sid */
-			object_sid = NULL;
-			sid = samdb_result_dom_sid(msg, msg, "objectSID");
-			if (sid) {
-				object_sid = dom_sid_string(msg, sid);
-				if (!object_sid)
-					return LDB_ERR_OPERATIONS_ERROR;
-
-			}
-			
-			/* Normal, sane format */
-			if (object_sid) {
-				new_dn = talloc_asprintf(msg, "<GUID=%s>;<SID=%s>;%s",
-							 object_guid, object_sid,
-							 ldb_dn_get_linearized(msg->dn));
-			} else {
-				new_dn = talloc_asprintf(msg, "<GUID=%s>;%s",
-							 object_guid,
-							 ldb_dn_get_linearized(msg->dn));
-			}
-			break;
-		default:
-			return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	if (!new_dn) {
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	if (remove_guid) {
-		ldb_msg_remove_attr(msg, "objectGUID");
-	}
-
-	if (sid_blob && remove_sid) {
-		ldb_msg_remove_attr(msg, "objectSID");
-	}
-
-	msg->dn = ldb_dn_new(msg, ldb, new_dn);
-	if (! ldb_dn_validate(msg->dn))
-		return LDB_ERR_OPERATIONS_ERROR;
-
-	val = ldb_msg_find_ldb_val(msg, "distinguishedName");
-	if (val) {
-		ldb_msg_remove_attr(msg, "distinguishedName");
-		if (ldb_msg_add_steal_string(msg, "distinguishedName", new_dn))
-			return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	return LDB_SUCCESS;
-}
-
-/* search */
-struct extended_context {
-
-	struct ldb_module *module;
-	struct ldb_request *req;
-	struct ldb_control *control;
-	struct ldb_dn *basedn;
-	char *wellknown_object;
-	bool inject;
-	bool remove_guid;
-	bool remove_sid;
-	int extended_type;
-	const char * const *cast_attrs;
-};
-
-static int extended_callback(struct ldb_request *req, struct ldb_reply *ares)
-{
-	struct extended_context *ac;
-	int ret;
-
-	ac = talloc_get_type(req->context, struct extended_context);
-
-	if (!ares) {
-		return ldb_module_done(ac->req, NULL, NULL,
-					LDB_ERR_OPERATIONS_ERROR);
-	}
-	if (ares->error != LDB_SUCCESS) {
-		return ldb_module_done(ac->req, ares->controls,
-					ares->response, ares->error);
-	}
-
-	switch (ares->type) {
-	case LDB_REPLY_ENTRY:
-		if (ac->inject) {
-			/* for each record returned post-process to add any derived
-			   attributes that have been asked for */
-			ret = inject_extended_dn(ares->message, ac->module->ldb,
-						 ac->extended_type, ac->remove_guid,
-						 ac->remove_sid);
-			if (ret != LDB_SUCCESS) {
-				return ldb_module_done(ac->req, NULL, NULL, ret);
-			}
-		}
-
-		return ldb_module_send_entry(ac->req, ares->message, ares->controls);
-
-	case LDB_REPLY_REFERRAL:
-		return ldb_module_send_referral(ac->req, ares->referral);
-
-	case LDB_REPLY_DONE:
-		return ldb_module_done(ac->req, ares->controls,
-					ares->response, LDB_SUCCESS);
-
-	}
-	return LDB_SUCCESS;
-}
-
-static int extended_base_callback(struct ldb_request *req, struct ldb_reply *ares)
-{
-	struct extended_context *ac;
-	struct ldb_request *down_req;
-	struct ldb_control **saved_controls;
-	struct ldb_message_element *el;
-	int ret;
-	size_t i;
-	size_t wkn_len = 0;
-	char *valstr = NULL;
-	const char *found = NULL;
-
-	ac = talloc_get_type(req->context, struct extended_context);
-
-	if (!ares) {
-		return ldb_module_done(ac->req, NULL, NULL,
-					LDB_ERR_OPERATIONS_ERROR);
-	}
-	if (ares->error != LDB_SUCCESS) {
-		return ldb_module_done(ac->req, ares->controls,
-					ares->response, ares->error);
-	}
-
-	switch (ares->type) {
-	case LDB_REPLY_ENTRY:
-		if (!ac->wellknown_object) {
-			ac->basedn = ares->message->dn;
-			break;
-		}
-
-		wkn_len = strlen(ac->wellknown_object);
-
-		el = ldb_msg_find_element(ares->message, "wellKnownObjects");
-		if (!el) {
-			ac->basedn = NULL;
-			break;
-		}
-
-		for (i=0; i < el->num_values; i++) {
-			valstr = talloc_strndup(ac,
-						(const char *)el->values[i].data,
-						el->values[i].length);
-			if (!valstr) {
-				ldb_oom(ac->module->ldb);
-				return ldb_module_done(ac->req, NULL, NULL,
-						       LDB_ERR_OPERATIONS_ERROR);
-			}
-
-			if (strncasecmp(valstr, ac->wellknown_object, wkn_len) != 0) {
-				talloc_free(valstr);
-				continue;
-			}
-
-			found = &valstr[wkn_len];
-			break;
-		}
-
-		if (!found) {
-			break;
-		}
-
-		ac->basedn = ldb_dn_new(ac, ac->module->ldb, found);
-		talloc_free(valstr);
-		if (!ac->basedn) {
-			ldb_oom(ac->module->ldb);
-			return ldb_module_done(ac->req, NULL, NULL,
-					       LDB_ERR_OPERATIONS_ERROR);
-		}
-
-		break;
-
-	case LDB_REPLY_REFERRAL:
-		break;
-
-	case LDB_REPLY_DONE:
-
-		if (!ac->basedn) {
-			const char *str = talloc_asprintf(req, "Base-DN '%s' not found",
-							  ldb_dn_get_linearized(ac->req->op.search.base));
-			ldb_set_errstring(ac->module->ldb, str);
-			return ldb_module_done(ac->req, NULL, NULL,
-					       LDB_ERR_NO_SUCH_OBJECT);
-		}
-
-		ret = ldb_build_search_req_ex(&down_req,
-						ac->module->ldb, ac,
-						ac->basedn,
-						ac->req->op.search.scope,
-						ac->req->op.search.tree,
-						ac->cast_attrs,
-						ac->req->controls,
-						ac, extended_callback,
-						ac->req);
-		if (ret != LDB_SUCCESS) {
-			return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
-		}
-
-		if (ac->control) {
-			/* save it locally and remove it from the list */
-			/* we do not need to replace them later as we
-			 * are keeping the original req intact */
-			if (!save_controls(ac->control, down_req, &saved_controls)) {
-				return ldb_module_done(ac->req, NULL, NULL,
-							LDB_ERR_OPERATIONS_ERROR);
-			}
-		}
-
-		/* perform the search */
-		return ldb_next_request(ac->module, down_req);
-	}
-	return LDB_SUCCESS;
-}
-
-static int extended_search(struct ldb_module *module, struct ldb_request *req)
-{
-	struct ldb_control *control;
-	struct ldb_extended_dn_control *extended_ctrl = NULL;
-	struct ldb_control **saved_controls;
-	struct extended_context *ac;
-	struct ldb_request *down_req;
-	char **new_attrs;
-	int ret;
-	struct ldb_dn *base_dn = NULL;
-	enum ldb_scope base_dn_scope = LDB_SCOPE_BASE;
-	const char *base_dn_filter = NULL;
-	const char * const *base_dn_attrs = NULL;
-	char *wellknown_object = NULL;
-	static const char *dnattr[] = {
-		"distinguishedName",
-		NULL
-	};
-	static const char *wkattr[] = {
-		"wellKnownObjects",
-		NULL
-	};
-
-	if (ldb_dn_is_special(req->op.search.base)) {
-		char *dn;
-
-		dn = ldb_dn_alloc_linearized(req, req->op.search.base);
-		if (!dn) {
-			ldb_oom(module->ldb);
-			return LDB_ERR_OPERATIONS_ERROR;
-		}
-
-		if (strncasecmp(dn, "<SID=", 5) == 0) {
-			char *str;
-			char *valstr;
-			char *p;
-
-			p = strchr(dn, '=');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-
-			p[0] = '\0';
-			p++;
-
-			str = p;
-
-			p = strchr(str, '>');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-			p[0] = '\0';
-
-			if (strncasecmp(str, "S-", 2) == 0) {
-				valstr = str;
-			} else {
-				DATA_BLOB binary;
-				binary = strhex_to_data_blob(NULL, str);
-				if (!binary.data) {
-					ldb_oom(module->ldb);
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-				valstr = ldb_binary_encode(req, binary);
-				data_blob_free(&binary);
-				if (!valstr) {
-					ldb_oom(module->ldb);
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-			}
-
-			/* TODO: do a search over all partitions */
-			base_dn = ldb_get_default_basedn(module->ldb);
-			base_dn_filter = talloc_asprintf(req, "(objectSid=%s)", valstr);
-			if (!base_dn_filter) {
-				ldb_oom(module->ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-			base_dn_scope = LDB_SCOPE_SUBTREE;
-			base_dn_attrs = dnattr;
-		} else if (strncasecmp(dn, "<GUID=", 6) == 0) {
-			char *str;
-			char *valstr;
-			char *p;
-
-			p = strchr(dn, '=');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-
-			p[0] = '\0';
-			p++;
-
-			str = p;
-
-			p = strchr(str, '>');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-			p[0] = '\0';
-
-			if (strchr(str, '-')) {
-				valstr = str;
-			} else {
-				DATA_BLOB binary;
-				binary = strhex_to_data_blob(NULL, str);
-				if (!binary.data) {
-					ldb_oom(module->ldb);
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-				valstr = ldb_binary_encode(req, binary);
-				data_blob_free(&binary);
-				if (!valstr) {
-					ldb_oom(module->ldb);
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-			}
-
-			/* TODO: do a search over all partitions */
-			base_dn = ldb_get_default_basedn(module->ldb);
-			base_dn_filter = talloc_asprintf(req, "(objectGUID=%s)", valstr);
-			if (!base_dn_filter) {
-				ldb_oom(module->ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-			base_dn_scope = LDB_SCOPE_SUBTREE;
-			base_dn_attrs = dnattr;
-		} else if (strncasecmp(dn, "<WKGUID=", 8) == 0) {
-			char *tail_str;
-			char *p;
-
-			p = strchr(dn, ',');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-
-			p[0] = '\0';
-			p++;
-
-			wellknown_object = talloc_asprintf(req, "B:32:%s:", &dn[8]);
-			if (!wellknown_object) {
-				ldb_oom(module->ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-
-			tail_str = p;
-			p = strchr(tail_str, '>');
-			if (!p) {
-				return LDB_ERR_INVALID_DN_SYNTAX;
-			}
-			p[0] = '\0';
-
-			base_dn = ldb_dn_new(req, module->ldb, tail_str);
-			if (!base_dn) {
-				ldb_oom(module->ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-			base_dn_filter = talloc_strdup(req, "(objectClass=*)");
-			if (!base_dn_filter) {
-				ldb_oom(module->ldb);
-				return LDB_ERR_OPERATIONS_ERROR;
-			}
-			base_dn_scope = LDB_SCOPE_BASE;
-			base_dn_attrs = wkattr;
-		}
-		talloc_free(dn);
-	}
-
-	/* check if there's an extended dn control */
-	control = ldb_request_get_control(req, LDB_CONTROL_EXTENDED_DN_OID);
-	if (control == NULL && base_dn_filter == NULL) {
-		/* not found go on */
-		return ldb_next_request(module, req);
-	}
-
-	if (control && control->data) {
-		extended_ctrl = talloc_get_type(control->data, struct ldb_extended_dn_control);
-		if (!extended_ctrl) {
-			return LDB_ERR_PROTOCOL_ERROR;
-		}
-	}
-
-	ac = talloc_zero(req, struct extended_context);
-	if (ac == NULL) {
-		ldb_oom(module->ldb);
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	ac->module = module;
-	ac->req = req;
-	ac->control = control;
-	ac->basedn = NULL;
-	ac->wellknown_object = wellknown_object;
-	ac->inject = false;
-	ac->remove_guid = false;
-	ac->remove_sid = false;
-
-	if (control) {
-		ac->inject = true;
-		if (extended_ctrl) {
-			ac->extended_type = extended_ctrl->type;
-		} else {
-			ac->extended_type = 0;
-		}
-
-		/* check if attrs only is specified, in that case check wether we need to modify them */
-		if (req->op.search.attrs) {
-			if (! is_attr_in_list(req->op.search.attrs, "objectGUID")) {
-				ac->remove_guid = true;
-			}
-			if (! is_attr_in_list(req->op.search.attrs, "objectSID")) {
-				ac->remove_sid = true;
-			}
-			if (ac->remove_guid || ac->remove_sid) {
-				new_attrs = copy_attrs(ac, req->op.search.attrs);
-				if (new_attrs == NULL) {
-					ldb_oom(module->ldb);
-					return LDB_ERR_OPERATIONS_ERROR;
-				}
-
-				if (ac->remove_guid) {
-					if (!add_attrs(ac, &new_attrs, "objectGUID"))
-						return LDB_ERR_OPERATIONS_ERROR;
-				}
-				if (ac->remove_sid) {
-					if (!add_attrs(ac, &new_attrs, "objectSID"))
-						return LDB_ERR_OPERATIONS_ERROR;
-				}
-				ac->cast_attrs = (const char * const *)new_attrs;
-			} else {
-				ac->cast_attrs = req->op.search.attrs;
-			}
-		}
-	}
-
-	if (base_dn) {
-		ret = ldb_build_search_req(&down_req,
-					   module->ldb, ac,
-					   base_dn,
-					   base_dn_scope,
-					   base_dn_filter,
-					   base_dn_attrs,
-					   NULL,
-					   ac, extended_base_callback,
-					   req);
-		if (ret != LDB_SUCCESS) {
-			return LDB_ERR_OPERATIONS_ERROR;
-		}
-
-		/* perform the search */
-		return ldb_next_request(module, down_req);
-	}
-
-	ret = ldb_build_search_req_ex(&down_req,
-					module->ldb, ac,
-					req->op.search.base,
-					req->op.search.scope,
-					req->op.search.tree,
-					ac->cast_attrs,
-					req->controls,
-					ac, extended_callback,
-					req);
-	if (ret != LDB_SUCCESS) {
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	if (ac->control) {
-		/* save it locally and remove it from the list */
-		/* we do not need to replace them later as we
-		 * are keeping the original req intact */
-		if (!save_controls(control, down_req, &saved_controls)) {
-			return LDB_ERR_OPERATIONS_ERROR;
-		}
-	}
-
-	/* perform the search */
-	return ldb_next_request(module, down_req);
-}
-
-static int extended_init(struct ldb_module *module)
-{
-	int ret;
-
-	ret = ldb_mod_register_control(module, LDB_CONTROL_EXTENDED_DN_OID);
-	if (ret != LDB_SUCCESS) {
-		ldb_debug(module->ldb, LDB_DEBUG_ERROR,
-			"extended_dn: Unable to register control with rootdse!\n");
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
-
-	return ldb_next_init(module);
-}
-
-_PUBLIC_ const struct ldb_module_ops ldb_extended_dn_module_ops = {
-	.name		   = "extended_dn",
-	.search            = extended_search,
-	.init_context	   = extended_init
-};
diff --git a/source4/dsdb/samdb/ldb_modules/extended_dn_in.c b/source4/dsdb/samdb/ldb_modules/extended_dn_in.c
new file mode 100644
index 0000000000..c3db4fa588
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/extended_dn_in.c
@@ -0,0 +1,394 @@
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce 2005-2008
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007-2008
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb extended dn control module
+ *
+ *  Description: this module interprets DNs of the form <SID=S-1-2-4456> into normal DNs.
+ *
+ *  Authors: Simo Sorce
+ *           Andrew Bartlett
+ */
+
+#include "includes.h"
+#include "ldb/include/ldb.h"
+#include "ldb/include/ldb_errors.h"
+#include "ldb/include/ldb_private.h"
+
+/* search */
+struct extended_search_context {
+	struct ldb_module *module;
+	struct ldb_request *req;
+	struct ldb_dn *basedn;
+	char *wellknown_object;
+	int extended_type;
+};
+
+/* An extra layer of indirection because LDB does not allow the original request to be altered */
+
+static int extended_final_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	int ret = LDB_ERR_OPERATIONS_ERROR;
+	struct extended_search_context *ac;
+	ac = talloc_get_type(req->context, struct extended_search_context);
+
+	if (ares->error != LDB_SUCCESS) {
+		ret = ldb_module_done(ac->req, ares->controls,
+				      ares->response, ares->error);
+	} else {
+		switch (ares->type) {
+		case LDB_REPLY_ENTRY:
+			
+			ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
+			break;
+		case LDB_REPLY_REFERRAL:
+			
+			ret = ldb_module_send_referral(ac->req, ares->referral);
+			break;
+		case LDB_REPLY_DONE:
+			
+			ret = ldb_module_done(ac->req, ares->controls,
+					      ares->response, ares->error);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int extended_base_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct extended_search_context *ac;
+	struct ldb_request *down_req;
+	struct ldb_message_element *el;
+	int ret;
+	size_t i;
+	size_t wkn_len = 0;
+	char *valstr = NULL;
+	const char *found = NULL;
+
+	ac = talloc_get_type(req->context, struct extended_search_context);
+
+	if (!ares) {
+		return ldb_module_done(ac->req, NULL, NULL,
+					LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_module_done(ac->req, ares->controls,
+					ares->response, ares->error);
+	}
+
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		if (!ac->wellknown_object) {
+			ac->basedn = talloc_steal(ac, ares->message->dn);
+			break;
+		}
+
+		wkn_len = strlen(ac->wellknown_object);
+
+		el = ldb_msg_find_element(ares->message, "wellKnownObjects");
+		if (!el) {
+			ac->basedn = NULL;
+			break;
+		}
+
+		for (i=0; i < el->num_values; i++) {
+			valstr = talloc_strndup(ac,
+						(const char *)el->values[i].data,
+						el->values[i].length);
+			if (!valstr) {
+				ldb_oom(ac->module->ldb);
+				return ldb_module_done(ac->req, NULL, NULL,
+						       LDB_ERR_OPERATIONS_ERROR);
+			}
+
+			if (strncasecmp(valstr, ac->wellknown_object, wkn_len) != 0) {
+				talloc_free(valstr);
+				continue;
+			}
+
+			found = &valstr[wkn_len];
+			break;
+		}
+
+		if (!found) {
+			break;
+		}
+
+		ac->basedn = ldb_dn_new(ac, ac->module->ldb, found);
+		talloc_free(valstr);
+		if (!ac->basedn) {
+			ldb_oom(ac->module->ldb);
+			return ldb_module_done(ac->req, NULL, NULL,
+					       LDB_ERR_OPERATIONS_ERROR);
+		}
+
+		break;
+
+	case LDB_REPLY_REFERRAL:
+		break;
+
+	case LDB_REPLY_DONE:
+
+		if (!ac->basedn) {
+			const char *str = talloc_asprintf(req, "Base-DN '%s' not found",
+							  ldb_dn_get_linearized(ac->req->op.search.base));
+			ldb_set_errstring(ac->module->ldb, str);
+			return ldb_module_done(ac->req, NULL, NULL,
+					       LDB_ERR_NO_SUCH_OBJECT);
+		}
+
+		switch (ac->req->operation) {
+		case LDB_SEARCH:
+			ret = ldb_build_search_req_ex(&down_req,
+						      ac->module->ldb, ac->req,
+						      ac->basedn,
+						      ac->req->op.search.scope,
+						      ac->req->op.search.tree,
+						      ac->req->op.search.attrs,
+						      ac->req->controls,
+						      ac, extended_final_callback, 
+						      ac->req);
+			break;
+		case LDB_ADD:
+		{
+			struct ldb_message *add_msg = ldb_msg_copy_shallow(ac, ac->req->op.add.message);
+			if (!add_msg) {
+				ldb_oom(ac->module->ldb);
+				return ldb_module_done(ac->req, NULL, NULL,
+						       LDB_ERR_OPERATIONS_ERROR);
+			}
+			
+			add_msg->dn = ac->basedn;
+
+			ret = ldb_build_add_req(&down_req,
+						ac->module->ldb, ac->req,
+						add_msg, 
+						ac->req->controls,
+						ac, extended_final_callback, 
+						ac->req);
+			break;
+		}
+		case LDB_MODIFY:
+		{
+			struct ldb_message *mod_msg = ldb_msg_copy_shallow(ac, ac->req->op.mod.message);
+			if (!mod_msg) {
+				ldb_oom(ac->module->ldb);
+				return ldb_module_done(ac->req, NULL, NULL,
+						       LDB_ERR_OPERATIONS_ERROR);
+			}
+			
+			mod_msg->dn = ac->basedn;
+
+			ret = ldb_build_mod_req(&down_req,
+						ac->module->ldb, ac->req,
+						mod_msg, 
+						ac->req->controls,
+						ac, extended_final_callback, 
+						ac->req);
+			break;
+		}
+		case LDB_DELETE:
+			ret = ldb_build_del_req(&down_req,
+						ac->module->ldb, ac->req,
+						ac->basedn, 
+						ac->req->controls,
+						ac, extended_final_callback, 
+						ac->req);
+			break;
+		case LDB_RENAME:
+			ret = ldb_build_rename_req(&down_req,
+						   ac->module->ldb, ac->req,
+						   ac->basedn, 
+						   ac->req->op.rename.newdn,
+						   ac->req->controls,
+						   ac, extended_final_callback, 
+						   ac->req);
+			break;
+		default:
+			return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
+		}
+		
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+
+		return ldb_next_request(ac->module, down_req);
+	}
+	talloc_free(ares);
+	return LDB_SUCCESS;
+}
+
+static int extended_dn_in_fix(struct ldb_module *module, struct ldb_request *req, struct ldb_dn *dn)
+{
+	struct extended_search_context *ac;
+	struct ldb_request *down_req;
+	int ret;
+	struct ldb_dn *base_dn = NULL;
+	enum ldb_scope base_dn_scope = LDB_SCOPE_BASE;
+	const char *base_dn_filter = NULL;
+	const char * const *base_dn_attrs = NULL;
+	char *wellknown_object = NULL;
+	static const char *no_attr[] = {
+		NULL
+	};
+	static const char *wkattr[] = {
+		"wellKnownObjects",
+		NULL
+	};
+
+	if (!ldb_dn_has_extended(dn)) {
+		/* Move along there isn't anything to see here */
+		return ldb_next_request(module, req);
+	} else {
+		/* It looks like we need to map the DN */
+		const struct ldb_val *sid_val, *guid_val, *wkguid_val;
+
+		sid_val = ldb_dn_get_extended_component(dn, "SID");
+		guid_val = ldb_dn_get_extended_component(dn, "GUID");
+		wkguid_val = ldb_dn_get_extended_component(dn, "WKGUID");
+
+		if (sid_val) {
+			/* TODO: do a search over all partitions */
+			base_dn = ldb_get_default_basedn(module->ldb);
+			base_dn_filter = talloc_asprintf(req, "(objectSid=%s)", 
+							 ldb_binary_encode(req, *sid_val));
+			if (!base_dn_filter) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			base_dn_scope = LDB_SCOPE_SUBTREE;
+			base_dn_attrs = no_attr;
+
+		} else if (guid_val) {
+
+			/* TODO: do a search over all partitions */
+			base_dn = ldb_get_default_basedn(module->ldb);
+			base_dn_filter = talloc_asprintf(req, "(objectGUID=%s)", 
+							 ldb_binary_encode(req, *guid_val));
+			if (!base_dn_filter) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			base_dn_scope = LDB_SCOPE_SUBTREE;
+			base_dn_attrs = no_attr;
+
+
+		} else if (wkguid_val) {
+			char *wkguid_dup;
+			char *tail_str;
+			char *p;
+
+			wkguid_dup = talloc_strndup(req, (char *)wkguid_val->data, wkguid_val->length);
+
+			p = strchr(wkguid_dup, ',');
+			if (!p) {
+				return LDB_ERR_INVALID_DN_SYNTAX;
+			}
+
+			p[0] = '\0';
+			p++;
+
+			wellknown_object = talloc_asprintf(req, "B:32:%s:", wkguid_dup);
+			if (!wellknown_object) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+
+			tail_str = p;
+
+			base_dn = ldb_dn_new(req, module->ldb, tail_str);
+			talloc_free(wkguid_dup);
+			if (!base_dn) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			base_dn_filter = talloc_strdup(req, "(objectClass=*)");
+			if (!base_dn_filter) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			base_dn_scope = LDB_SCOPE_BASE;
+			base_dn_attrs = wkattr;
+		} else {
+			return LDB_ERR_INVALID_DN_SYNTAX;
+		}
+
+		ac = talloc_zero(req, struct extended_search_context);
+		if (ac == NULL) {
+			ldb_oom(module->ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		
+		ac->module = module;
+		ac->req = req;
+		ac->basedn = NULL;  /* Filled in if the search finds the DN by SID/GUID etc */
+		ac->wellknown_object = wellknown_object;
+		
+		/* If the base DN was an extended DN (perhaps a well known
+		 * GUID) then search for that, so we can proceed with the original operation */
+
+		ret = ldb_build_search_req(&down_req,
+					   module->ldb, ac,
+					   base_dn,
+					   base_dn_scope,
+					   base_dn_filter,
+					   base_dn_attrs,
+					   NULL,
+					   ac, extended_base_callback,
+					   req);
+		if (ret != LDB_SUCCESS) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		/* perform the search */
+		return ldb_next_request(module, down_req);
+	}
+}
+
+static int extended_dn_in_search(struct ldb_module *module, struct ldb_request *req)
+{
+	return extended_dn_in_fix(module, req, req->op.search.base);
+}
+
+static int extended_dn_in_modify(struct ldb_module *module, struct ldb_request *req)
+{
+	return extended_dn_in_fix(module, req, req->op.mod.message->dn);
+}
+
+static int extended_dn_in_del(struct ldb_module *module, struct ldb_request *req)
+{
+	return extended_dn_in_fix(module, req, req->op.del.dn);
+}
+
+static int extended_dn_in_rename(struct ldb_module *module, struct ldb_request *req)
+{
+	return extended_dn_in_fix(module, req, req->op.rename.olddn);
+}
+
+_PUBLIC_ const struct ldb_module_ops ldb_extended_dn_in_module_ops = {
+	.name		   = "extended_dn_in",
+	.search            = extended_dn_in_search,
+	.modify            = extended_dn_in_modify,
+	.del               = extended_dn_in_del,
+	.rename            = extended_dn_in_rename,
+};
diff --git a/source4/dsdb/samdb/ldb_modules/extended_dn_out.c b/source4/dsdb/samdb/ldb_modules/extended_dn_out.c
new file mode 100644
index 0000000000..058c51bdb8
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/extended_dn_out.c
@@ -0,0 +1,655 @@
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce 2005-2008
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007-2008
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb extended dn control module
+ *
+ *  Description: this module builds a special dn for returned search
+ *  results, and fixes some other aspects of the result (returned case issues)
+ *  values.
+ *
+ *  Authors: Simo Sorce
+ *           Andrew Bartlett
+ */
+
+#include "includes.h"
+#include "ldb/include/ldb.h"
+#include "ldb/include/ldb_errors.h"
+#include "ldb/include/ldb_private.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/ndr/libndr.h"
+#include "dsdb/samdb/samdb.h"
+
+struct extended_dn_out_private {
+	bool dereference;
+	bool normalise;
+	struct dsdb_openldap_dereference_control *dereference_control;
+};
+
+static bool is_attr_in_list(const char * const * attrs, const char *attr)
+{
+	int i;
+
+	for (i = 0; attrs[i]; i++) {
+		if (ldb_attr_cmp(attrs[i], attr) == 0)
+			return true;
+	}
+
+	return false;
+}
+
+static char **copy_attrs(void *mem_ctx, const char * const * attrs)
+{
+	char **new;
+	int i, num;
+
+	for (num = 0; attrs[num]; num++);
+
+	new = talloc_array(mem_ctx, char *, num + 1);
+	if (!new) return NULL;
+
+	for(i = 0; i < num; i++) {
+		new[i] = talloc_strdup(new, attrs[i]);
+		if (!new[i]) {
+			talloc_free(new);
+			return NULL;
+		}
+	}
+	new[i] = NULL;
+
+	return new;
+}
+
+static bool add_attrs(void *mem_ctx, char ***attrs, const char *attr)
+{
+	char **new;
+	int num;
+
+	for (num = 0; (*attrs)[num]; num++);
+
+	new = talloc_realloc(mem_ctx, *attrs, char *, num + 2);
+	if (!new) return false;
+
+	*attrs = new;
+
+	new[num] = talloc_strdup(new, attr);
+	if (!new[num]) return false;
+
+	new[num + 1] = NULL;
+
+	return true;
+}
+
+/* Fix the DN so that the relative attribute names are in upper case so that the DN:
+   cn=Adminstrator,cn=users,dc=samba,dc=example,dc=com becomes
+   CN=Adminstrator,CN=users,DC=samba,DC=example,DC=com
+*/
+
+
+static int fix_dn(struct ldb_dn *dn) 
+{
+	int i, ret;
+	char *upper_rdn_attr;
+
+	for (i=0; i < ldb_dn_get_comp_num(dn); i++) {
+		/* We need the attribute name in upper case */
+		upper_rdn_attr = strupper_talloc(dn,
+						 ldb_dn_get_component_name(dn, i));
+		if (!upper_rdn_attr) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		
+		/* And replace it with CN=foo (we need the attribute in upper case */
+		ret = ldb_dn_set_component(dn, i, upper_rdn_attr,
+					   *ldb_dn_get_component_val(dn, i));
+		talloc_free(upper_rdn_attr);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
+	return LDB_SUCCESS;
+}
+
+/* Inject the extended DN components, so the DN cn=Adminstrator,cn=users,dc=samba,dc=example,dc=com becomes
+   <GUID=541203ae-f7d6-47ef-8390-bfcf019f9583>;<SID=S-1-5-21-4177067393-1453636373-93818737-500>;cn=Adminstrator,cn=users,dc=samba,dc=example,dc=com */
+
+static int inject_extended_dn_out(struct ldb_reply *ares,
+				  struct ldb_context *ldb,
+				  int type,
+				  bool remove_guid,
+				  bool remove_sid)
+{
+	int ret;
+	const DATA_BLOB *guid_blob;
+	const DATA_BLOB *sid_blob;
+
+	guid_blob = ldb_msg_find_ldb_val(ares->message, "objectGUID");
+	sid_blob = ldb_msg_find_ldb_val(ares->message, "objectSID");
+
+	if (!guid_blob) {
+		ldb_set_errstring(ldb, "Did not find objectGUID to inject into extended DN");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ret = ldb_dn_set_extended_component(ares->message->dn, "GUID", guid_blob);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	if (sid_blob) {
+		ret = ldb_dn_set_extended_component(ares->message->dn, "SID", sid_blob);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
+
+	if (remove_guid) {
+		ldb_msg_remove_attr(ares->message, "objectGUID");
+	}
+
+	if (sid_blob && remove_sid) {
+		ldb_msg_remove_attr(ares->message, "objectSID");
+	}
+
+	return LDB_SUCCESS;
+}
+
+static int handle_dereference(struct ldb_dn *dn,
+			      struct dsdb_openldap_dereference_result **dereference_attrs, 
+			      const char *attr, const DATA_BLOB *val)
+{
+	const struct ldb_val *entryUUIDblob, *sid_blob;
+	struct ldb_message fake_msg; /* easier to use routines that expect an ldb_message */
+	int j;
+	
+	fake_msg.num_elements = 0;
+			
+	/* Look for this attribute in the returned control */
+	for (j = 0; dereference_attrs && dereference_attrs[j]; j++) {
+		struct ldb_val source_dn = data_blob_string_const(dereference_attrs[j]->dereferenced_dn);
+		if (ldb_attr_cmp(dereference_attrs[j]->source_attribute, attr) == 0
+		    && data_blob_cmp(&source_dn, val) == 0) {
+			fake_msg.num_elements = dereference_attrs[j]->num_attributes;
+			fake_msg.elements = dereference_attrs[j]->attributes;
+			break;
+		}
+	}
+	if (!fake_msg.num_elements) {
+		return LDB_SUCCESS;
+	}
+	/* Look for an OpenLDAP entryUUID */
+	
+	entryUUIDblob = ldb_msg_find_ldb_val(&fake_msg, "entryUUID");
+	if (entryUUIDblob) {
+		NTSTATUS status;
+		enum ndr_err_code ndr_err;
+		
+		struct ldb_val guid_blob;
+		struct GUID guid;
+		
+		status = GUID_from_data_blob(entryUUIDblob, &guid);
+		
+		if (!NT_STATUS_IS_OK(status)) {
+			return LDB_ERR_INVALID_DN_SYNTAX;
+		}
+		ndr_err = ndr_push_struct_blob(&guid_blob, NULL, NULL, &guid,
+					       (ndr_push_flags_fn_t)ndr_push_GUID);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			return LDB_ERR_INVALID_DN_SYNTAX;
+		}
+		
+		ldb_dn_set_extended_component(dn, "GUID", &guid_blob);
+	}
+	
+	sid_blob = ldb_msg_find_ldb_val(&fake_msg, "objectSID");
+	
+	/* Look for the objectSID */
+	if (sid_blob) {
+		ldb_dn_set_extended_component(dn, "SID", sid_blob);
+	}
+	return LDB_SUCCESS;
+}
+
+/* search */
+struct extended_search_context {
+	struct ldb_module *module;
+	const struct dsdb_schema *schema;
+	struct ldb_request *req;
+	bool inject;
+	bool remove_guid;
+	bool remove_sid;
+	int extended_type;
+};
+
+static int extended_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct extended_search_context *ac;
+	struct ldb_control *control;
+	struct dsdb_openldap_dereference_result_control *dereference_control = NULL;
+	int ret, i, j;
+	struct ldb_message *msg = ares->message;
+	struct extended_dn_out_private *private;
+
+	ac = talloc_get_type(req->context, struct extended_search_context);
+	private = talloc_get_type(ac->module->private_data, struct extended_dn_out_private);
+
+	if (!ares) {
+		return ldb_module_done(ac->req, NULL, NULL,
+					LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_module_done(ac->req, ares->controls,
+					ares->response, ares->error);
+	}
+
+	switch (ares->type) {
+	case LDB_REPLY_REFERRAL:
+		return ldb_module_send_referral(ac->req, ares->referral);
+
+	case LDB_REPLY_DONE:
+		return ldb_module_done(ac->req, ares->controls,
+					ares->response, LDB_SUCCESS);
+	case LDB_REPLY_ENTRY:
+		break;
+	}
+
+	if (private && private->normalise) {
+		ret = fix_dn(ares->message->dn);
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+	}
+			
+	if (ac->inject) {
+		/* for each record returned post-process to add any derived
+		   attributes that have been asked for */
+		ret = inject_extended_dn_out(ares, ac->module->ldb,
+					     ac->extended_type, ac->remove_guid,
+					     ac->remove_sid);
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+	}
+
+	if ((private && private->normalise) || ac->inject) {
+		const struct ldb_val *val = ldb_msg_find_ldb_val(ares->message, "distinguishedName");
+		if (val) {
+			ldb_msg_remove_attr(ares->message, "distinguishedName");
+			if (ac->inject) {
+				ret = ldb_msg_add_steal_string(ares->message, "distinguishedName", 
+							       ldb_dn_get_extended_linearized(ares->message, ares->message->dn, ac->extended_type));
+			} else {
+				ret = ldb_msg_add_string(ares->message, "distinguishedName", 
+							 ldb_dn_get_linearized(ares->message->dn));
+			}
+			if (ret != LDB_SUCCESS) {
+				ldb_oom(ac->module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+		}
+	}
+
+	if (private && private->dereference) {
+		control = ldb_reply_get_control(ares, DSDB_OPENLDAP_DEREFERENCE_CONTROL);
+	
+		if (control && control->data) {
+			dereference_control = talloc_get_type(control->data, struct dsdb_openldap_dereference_result_control);
+		}
+	}
+
+	/* Walk the retruned elements (but only if we have a schema to interpret the list with) */
+	for (i = 0; ac->schema && i < msg->num_elements; i++) {
+		const struct dsdb_attribute *attribute;
+		attribute = dsdb_attribute_by_lDAPDisplayName(ac->schema, msg->elements[i].name);
+		if (!attribute) {
+			continue;
+		}
+
+		if (private->normalise) {
+			/* If we are also in 'normalise' mode, then
+			 * fix the attribute names to be in the
+			 * correct case */
+			msg->elements[i].name = talloc_strdup(msg->elements, attribute->lDAPDisplayName);
+			if (!msg->elements[i].name) {
+				ldb_oom(ac->module->ldb);
+				return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
+			}
+		}
+
+		/* distinguishedName has been dealt with above */
+		if (ldb_attr_cmp(msg->elements[i].name, "distinguishedName") == 0) {
+			continue;
+		}
+
+		/* Look to see if this attributeSyntax is a DN */
+		if (strcmp(attribute->attributeSyntax_oid, "2.5.5.1") != 0) {
+			continue;
+		}
+
+		for (j = 0; j < msg->elements[i].num_values; j++) {
+			const char *dn_str;
+			struct ldb_dn *dn = ldb_dn_from_ldb_val(ac, ac->module->ldb, &msg->elements[i].values[j]);
+			if (!dn || !ldb_dn_validate(dn)) {
+				return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_INVALID_DN_SYNTAX);
+			}
+
+			if (private->normalise) {
+				ret = fix_dn(dn);
+				if (ret != LDB_SUCCESS) {
+					return ldb_module_done(ac->req, NULL, NULL, ret);
+				}
+			}
+			
+			/* If we are running in dereference mode (such
+			 * as against OpenLDAP) then the DN in the msg
+			 * above does not contain the extended values,
+			 * and we need to look in the dereference
+			 * result */
+
+			/* Look for this value in the attribute */
+
+			if (dereference_control) {
+				ret = handle_dereference(dn, 
+							 dereference_control->attributes,
+							 msg->elements[i].name,
+							 &msg->elements[i].values[j]);
+				if (ret != LDB_SUCCESS) {
+					return ldb_module_done(ac->req, NULL, NULL, ret);
+				}
+			}
+			
+			if (!ac->inject) {
+				dn_str = talloc_steal(msg->elements[i].values, 
+						      ldb_dn_get_linearized(dn));
+			} else {
+				dn_str = talloc_steal(msg->elements[i].values, 
+						      ldb_dn_get_extended_linearized(msg->elements[i].values, 
+										     dn, ac->extended_type));
+			}
+			if (!dn_str) {
+				ldb_oom(ac->module->ldb);
+				return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
+			}
+			msg->elements[i].values[j] = data_blob_string_const(dn_str);
+			talloc_free(dn);
+		}
+	}
+	return ldb_module_send_entry(ac->req, msg, ares->controls);
+}
+
+
+static int extended_dn_out_search(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_control *control;
+	struct ldb_control *storage_format_control;
+	struct ldb_extended_dn_control *extended_ctrl = NULL;
+	struct ldb_control **saved_controls;
+	struct extended_search_context *ac;
+	struct ldb_request *down_req;
+	char **new_attrs;
+	const char * const *const_attrs;
+	int ret;
+
+	struct extended_dn_out_private *private = talloc_get_type(module->private_data, struct extended_dn_out_private);
+
+	/* check if there's an extended dn control */
+	control = ldb_request_get_control(req, LDB_CONTROL_EXTENDED_DN_OID);
+	if (control && control->data) {
+		extended_ctrl = talloc_get_type(control->data, struct ldb_extended_dn_control);
+		if (!extended_ctrl) {
+			return LDB_ERR_PROTOCOL_ERROR;
+		}
+	}
+
+	/* Look to see if, as we are in 'store DN+GUID+SID' mode, the
+	 * client is after the storage format (to fill in linked
+	 * attributes) */
+	storage_format_control = ldb_request_get_control(req, DSDB_CONTROL_DN_STORAGE_FORMAT_OID);
+	if (!control && storage_format_control && storage_format_control->data) {
+		extended_ctrl = talloc_get_type(storage_format_control->data, struct ldb_extended_dn_control);
+		if (!extended_ctrl) {
+			ldb_set_errstring(module->ldb, "extended_dn_out: extended_ctrl was of the wrong data type");
+			return LDB_ERR_PROTOCOL_ERROR;
+		}
+	}
+
+	ac = talloc_zero(req, struct extended_search_context);
+	if (ac == NULL) {
+		ldb_oom(module->ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->module = module;
+	ac->schema = dsdb_get_schema(module->ldb);
+	ac->req = req;
+	ac->inject = false;
+	ac->remove_guid = false;
+	ac->remove_sid = false;
+	
+	const_attrs = req->op.search.attrs;
+
+	/* We only need to do special processing if we were asked for
+	 * the extended DN, or we are 'store DN+GUID+SID'
+	 * (!dereference) mode.  (This is the normal mode for LDB on
+	 * tdb). */
+	if (control || (storage_format_control && private && !private->dereference)) {
+		ac->inject = true;
+		if (extended_ctrl) {
+			ac->extended_type = extended_ctrl->type;
+		} else {
+			ac->extended_type = 0;
+		}
+
+		/* check if attrs only is specified, in that case check wether we need to modify them */
+		if (req->op.search.attrs && !is_attr_in_list(req->op.search.attrs, "*")) {
+			if (! is_attr_in_list(req->op.search.attrs, "objectGUID")) {
+				ac->remove_guid = true;
+			}
+			if (! is_attr_in_list(req->op.search.attrs, "objectSID")) {
+				ac->remove_sid = true;
+			}
+			if (ac->remove_guid || ac->remove_sid) {
+				new_attrs = copy_attrs(ac, req->op.search.attrs);
+				if (new_attrs == NULL) {
+					ldb_oom(module->ldb);
+					return LDB_ERR_OPERATIONS_ERROR;
+				}
+
+				if (ac->remove_guid) {
+					if (!add_attrs(ac, &new_attrs, "objectGUID"))
+						return LDB_ERR_OPERATIONS_ERROR;
+				}
+				if (ac->remove_sid) {
+					if (!add_attrs(ac, &new_attrs, "objectSID"))
+						return LDB_ERR_OPERATIONS_ERROR;
+				}
+				const_attrs = (const char * const *)new_attrs;
+			}
+		}
+	}
+
+	ret = ldb_build_search_req_ex(&down_req,
+				      module->ldb, ac,
+				      req->op.search.base,
+				      req->op.search.scope,
+				      req->op.search.tree,
+				      const_attrs,
+				      req->controls,
+				      ac, extended_callback,
+				      req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	/* Remove extended DN and storage format controls */
+
+	if (control) {
+		/* save it locally and remove it from the list */
+		/* we do not need to replace them later as we
+		 * are keeping the original req intact */
+		if (!save_controls(control, down_req, &saved_controls)) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+	}
+
+	if (storage_format_control) {
+		/* save it locally and remove it from the list */
+		/* we do not need to replace them later as we
+		 * are keeping the original req intact */
+		if (!save_controls(storage_format_control, down_req, &saved_controls)) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+	}
+
+	/* Add in dereference control, if we were asked to, we are
+	 * using the 'dereference' mode (such as with an OpenLDAP
+	 * backend) and have the control prepared */
+	if (control && private && private->dereference && private->dereference_control) {
+		ret = ldb_request_add_control(down_req,
+					      DSDB_OPENLDAP_DEREFERENCE_CONTROL,
+					      false, private->dereference_control);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
+
+	/* perform the search */
+	return ldb_next_request(module, down_req);
+}
+
+static int extended_dn_out_ldb_init(struct ldb_module *module)
+{
+	int ret;
+
+	struct extended_dn_out_private *private = talloc(module, struct extended_dn_out_private);
+
+	module->private_data = private;
+
+	if (!private) {
+		ldb_oom(module->ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	private->dereference = false;
+	private->normalise = false;
+
+	ret = ldb_mod_register_control(module, LDB_CONTROL_EXTENDED_DN_OID);
+	if (ret != LDB_SUCCESS) {
+		ldb_debug(module->ldb, LDB_DEBUG_ERROR,
+			"extended_dn_out: Unable to register control with rootdse!\n");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	return ldb_next_init(module);
+}
+
+static int extended_dn_out_dereference_init(struct ldb_module *module)
+{
+	int ret, i = 0;
+	struct extended_dn_out_private *private;
+	struct dsdb_openldap_dereference_control *dereference_control;
+	struct dsdb_attribute *cur;
+
+	struct dsdb_schema *schema;
+
+	module->private_data = private = talloc_zero(module, struct extended_dn_out_private);
+
+	if (!private) {
+		ldb_oom(module->ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	private->dereference = true;
+
+	/* At the moment, servers that need dereference also need the
+	 * DN and attribute names to be normalised */
+	private->normalise = true;
+
+	ret = ldb_mod_register_control(module, LDB_CONTROL_EXTENDED_DN_OID);
+	if (ret != LDB_SUCCESS) {
+		ldb_debug(module->ldb, LDB_DEBUG_ERROR,
+			"extended_dn_out: Unable to register control with rootdse!\n");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ret = ldb_next_init(module);
+
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	schema = dsdb_get_schema(module->ldb);
+	if (!schema) {
+		/* No schema on this DB (yet) */
+		return LDB_SUCCESS;
+	}
+
+	private->dereference_control = dereference_control
+		= talloc_zero(private, struct dsdb_openldap_dereference_control);
+
+	if (!private->dereference_control) {
+		ldb_oom(module->ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	
+	for (cur = schema->attributes; cur; cur = cur->next) {
+		static const char *attrs[] = {
+			"entryUUID",
+			"objectSID",
+			NULL
+		};
+
+		if (strcmp(cur->syntax->attributeSyntax_oid, "2.5.5.1") != 0) {
+			continue;
+		}
+		dereference_control->dereference
+			= talloc_realloc(private, dereference_control->dereference, 
+					 struct dsdb_openldap_dereference *, i + 2);
+		if (!dereference_control) {
+			ldb_oom(module->ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		dereference_control->dereference[i] = talloc(dereference_control->dereference,  
+					 struct dsdb_openldap_dereference);
+		if (!dereference_control->dereference[i]) {
+			ldb_oom(module->ldb);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		dereference_control->dereference[i]->source_attribute = cur->lDAPDisplayName;
+		dereference_control->dereference[i]->dereference_attribute = attrs;
+		i++;
+		dereference_control->dereference[i] = NULL;
+	}
+	return LDB_SUCCESS;
+}
+
+_PUBLIC_ const struct ldb_module_ops ldb_extended_dn_out_ldb_module_ops = {
+	.name		   = "extended_dn_out_ldb",
+	.search            = extended_dn_out_search,
+	.init_context	   = extended_dn_out_ldb_init,
+};
+
+
+_PUBLIC_ const struct ldb_module_ops ldb_extended_dn_out_dereference_module_ops = {
+	.name		   = "extended_dn_out_dereference",
+	.search            = extended_dn_out_search,
+	.init_context	   = extended_dn_out_dereference_init,
+};
diff --git a/source4/dsdb/samdb/ldb_modules/extended_dn_store.c b/source4/dsdb/samdb/ldb_modules/extended_dn_store.c
new file mode 100644
index 0000000000..4f4e9d0fd7
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/extended_dn_store.c
@@ -0,0 +1,431 @@
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce 2005-2008
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007-2008
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb extended dn control module
+ *
+ *  Description: this module builds a special dn for returned search
+ *  results nad creates the special DN in the backend store for new
+ *  values.
+ *
+ *  This also has the curious result that we convert <SID=S-1-2-345>
+ *  in an attribute value into a normal DN for the rest of the stack
+ *  to process
+ *
+ *  Authors: Simo Sorce
+ *           Andrew Bartlett
+ */
+
+#include "includes.h"
+#include "ldb/include/ldb.h"
+#include "ldb/include/ldb_errors.h"
+#include "ldb/include/ldb_private.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "dsdb/samdb/samdb.h"
+#include "libcli/security/security.h"
+
+#include <time.h>
+
+struct extended_dn_replace_list {
+	struct extended_dn_replace_list *next;
+	struct ldb_dn *dn;
+	TALLOC_CTX *mem_ctx;
+	struct ldb_val *replace_dn;
+	struct extended_dn_context *ac;
+	struct ldb_request *search_req;
+};
+
+
+struct extended_dn_context {
+	const struct dsdb_schema *schema;
+	struct ldb_module *module;
+	struct ldb_request *req;
+	struct ldb_request *new_req;
+
+	struct extended_dn_replace_list *ops;
+	struct extended_dn_replace_list *cur;
+};
+
+
+static struct extended_dn_context *extended_dn_context_init(struct ldb_module *module,
+							    struct ldb_request *req)
+{
+	struct extended_dn_context *ac;
+
+	ac = talloc_zero(req, struct extended_dn_context);
+	if (ac == NULL) {
+		ldb_oom(module->ldb);
+		return NULL;
+	}
+
+	ac->schema = dsdb_get_schema(module->ldb);
+	ac->module = module;
+	ac->req = req;
+
+	return ac;
+}
+
+/* An extra layer of indirection because LDB does not allow the original request to be altered */
+
+static int extended_final_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	int ret = LDB_ERR_OPERATIONS_ERROR;
+	struct extended_dn_context *ac;
+	ac = talloc_get_type(req->context, struct extended_dn_context);
+
+	if (ares->error != LDB_SUCCESS) {
+		ret = ldb_module_done(ac->req, ares->controls,
+				      ares->response, ares->error);
+	} else {
+		switch (ares->type) {
+		case LDB_REPLY_ENTRY:
+			
+			ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
+			break;
+		case LDB_REPLY_REFERRAL:
+			
+			ret = ldb_module_send_referral(ac->req, ares->referral);
+			break;
+		case LDB_REPLY_DONE:
+			
+			ret = ldb_module_done(ac->req, ares->controls,
+					      ares->response, ares->error);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int extended_replace_dn(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct extended_dn_replace_list *os = talloc_get_type(req->context, 
+							   struct extended_dn_replace_list);
+
+	if (!ares) {
+		return ldb_module_done(os->ac->req, NULL, NULL,
+					LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error == LDB_ERR_NO_SUCH_OBJECT) {
+		/* Don't worry too much about dangling references */
+
+		ldb_reset_err_string(os->ac->module->ldb);
+		if (os->next) {
+			struct extended_dn_replace_list *next;
+
+			next = os->next;
+
+			talloc_free(os);
+
+			os = next;
+			return ldb_next_request(os->ac->module, next->search_req);
+		} else {
+			/* Otherwise, we are done - let's run the
+			 * request now we have swapped the DNs for the
+			 * full versions */
+			return ldb_next_request(os->ac->module, os->ac->req);
+		}
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_module_done(os->ac->req, ares->controls,
+					ares->response, ares->error);
+	}
+
+	/* Only entries are interesting, and we only want the olddn */
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+	{
+		/* This *must* be the right DN, as this is a base
+		 * search.  We can't check, as it could be an extended
+		 * DN, so a module below will resolve it */
+		struct ldb_dn *dn = ares->message->dn;
+
+		/* Replace the DN with the extended version of the DN
+		 * (ie, add SID and GUID) */
+		*os->replace_dn = data_blob_string_const(
+			ldb_dn_get_extended_linearized(os->mem_ctx, 
+						       dn, 1));
+		if (os->replace_dn->data == NULL) {
+			return ldb_module_done(os->ac->req, NULL, NULL,
+						LDB_ERR_OPERATIONS_ERROR);
+		}
+		break;
+	}
+	case LDB_REPLY_REFERRAL:
+		/* ignore */
+		break;
+
+	case LDB_REPLY_DONE:
+
+		talloc_free(ares);
+		
+		/* Run the next search */
+
+		if (os->next) {
+			struct extended_dn_replace_list *next;
+
+			next = os->next;
+
+			talloc_free(os);
+
+			os = next;
+			return ldb_next_request(os->ac->module, next->search_req);
+		} else {
+			/* Otherwise, we are done - let's run the
+			 * request now we have swapped the DNs for the
+			 * full versions */
+			return ldb_next_request(os->ac->module, os->ac->new_req);
+		}
+	}
+
+	talloc_free(ares);
+	return LDB_SUCCESS;
+}
+
+/* We have a 'normal' DN in the inbound request.  We need to find out
+ * what the GUID and SID are on the DN it points to, so we can
+ * construct an extended DN for storage.
+ *
+ * This creates a list of DNs to look up, and the plain DN to replace
+ */
+
+static int extended_store_replace(struct extended_dn_context *ac,
+				  TALLOC_CTX *callback_mem_ctx,
+				  struct ldb_val *plain_dn)
+{
+	int ret;
+	struct extended_dn_replace_list *os;
+	static const char *attrs[] = {
+		"objectSid",
+		"objectGUID",
+		NULL
+	};
+
+	os = talloc_zero(ac, struct extended_dn_replace_list);
+	if (!os) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	os->ac = ac;
+	
+	os->mem_ctx = callback_mem_ctx;
+
+	os->dn = ldb_dn_from_ldb_val(os, ac->module->ldb, plain_dn);
+	if (!os->dn || !ldb_dn_validate(os->dn)) {
+		talloc_free(os);
+		ldb_asprintf_errstring(ac->module->ldb, 
+				       "could not parse %.*s as a DN", (int)plain_dn->length, plain_dn->data);
+		return LDB_ERR_INVALID_DN_SYNTAX;
+	}
+
+	os->replace_dn = plain_dn;
+
+	/* The search request here might happen to be for an
+	 * 'extended' style DN, such as <GUID=abced...>.  The next
+	 * module in the stack will convert this into a normal DN for
+	 * processing */
+	ret = ldb_build_search_req(&os->search_req,
+				   ac->module->ldb, os, os->dn, LDB_SCOPE_BASE, NULL, 
+				   attrs, NULL, os, extended_replace_dn,
+				   ac->req);
+
+	if (ret != LDB_SUCCESS) {
+		talloc_free(os);
+		return ret;
+	}
+
+	ret = ldb_request_add_control(os->search_req,
+				      DSDB_CONTROL_DN_STORAGE_FORMAT_OID,
+				      true, NULL);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(os);
+		return ret;
+	}
+
+	if (ac->ops) {
+		ac->cur->next = os;
+	} else {
+		ac->ops = os;
+	}
+	ac->cur = os;
+
+	return LDB_SUCCESS;
+}
+
+
+/* add */
+static int extended_dn_add(struct ldb_module *module, struct ldb_request *req)
+{
+	struct extended_dn_context *ac;
+	int ret;
+	int i, j;
+
+	if (ldb_dn_is_special(req->op.add.message->dn)) {
+		/* do not manipulate our control entries */
+		return ldb_next_request(module, req);
+	}
+
+	ac = extended_dn_context_init(module, req);
+	if (!ac) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	if (!ac->schema) {
+		/* without schema, this doesn't make any sense */
+		talloc_free(ac);
+		return ldb_next_request(module, req);
+	}
+
+	for (i=0; i < req->op.add.message->num_elements; i++) {
+		const struct ldb_message_element *el = &req->op.add.message->elements[i];
+		const struct dsdb_attribute *schema_attr
+			= dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
+		if (!schema_attr) {
+			continue;
+		}
+
+		/* We only setup an extended DN GUID on these particular DN objects */
+		if (strcmp(schema_attr->attributeSyntax_oid, "2.5.5.1") != 0) {
+			continue;
+		}
+
+		/* Before we setup a procedure to modify the incoming message, we must copy it */
+		if (!ac->new_req) {
+			struct ldb_message *msg = ldb_msg_copy(ac, req->op.add.message);
+			if (!msg) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+		   
+			ret = ldb_build_add_req(&ac->new_req, module->ldb, ac, msg, req->controls, ac, extended_final_callback, req);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+		}
+		/* Re-calculate el */
+		el = &ac->new_req->op.add.message->elements[i];
+		for (j = 0; j < el->num_values; j++) {
+			ret = extended_store_replace(ac, ac->new_req->op.add.message->elements, &el->values[j]);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+		}
+	}
+
+	/* if DNs were set continue */
+	if (ac->ops == NULL) {
+		talloc_free(ac);
+		return ldb_next_request(module, req);
+	}
+
+	/* start with the searches */
+	return ldb_next_request(module, ac->ops->search_req);
+}
+
+/* modify */
+static int extended_dn_modify(struct ldb_module *module, struct ldb_request *req)
+{
+	/* Look over list of modifications */
+	/* Find if any are for linked attributes */
+	/* Determine the effect of the modification */
+	/* Apply the modify to the linked entry */
+
+	int i, j;
+	struct extended_dn_context *ac;
+	int ret;
+
+	if (ldb_dn_is_special(req->op.mod.message->dn)) {
+		/* do not manipulate our control entries */
+		return ldb_next_request(module, req);
+	}
+
+	ac = extended_dn_context_init(module, req);
+	if (!ac) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	if (!ac->schema) {
+		/* without schema, this doesn't make any sense */
+		return ldb_next_request(module, req);
+	}
+
+	for (i=0; i < req->op.mod.message->num_elements; i++) {
+		const struct ldb_message_element *el = &req->op.mod.message->elements[i];
+		const struct dsdb_attribute *schema_attr
+			= dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
+		if (!schema_attr) {
+			continue;
+		}
+
+		/* We only setup an extended DN GUID on these particular DN objects */
+		if (strcmp(schema_attr->attributeSyntax_oid, "2.5.5.1") != 0) {
+			continue;
+		}
+		
+		/* Before we setup a procedure to modify the incoming message, we must copy it */
+		if (!ac->new_req) {
+			struct ldb_message *msg = ldb_msg_copy(ac, req->op.mod.message);
+			if (!msg) {
+				ldb_oom(module->ldb);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+		   
+			ret = ldb_build_mod_req(&ac->new_req, module->ldb, ac, msg, req->controls, ac, extended_final_callback, req);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+		}
+		/* Re-calculate el */
+		el = &ac->new_req->op.mod.message->elements[i];
+		/* For each value being added, we need to setup the lookups to fill in the extended DN */
+		for (j = 0; j < el->num_values; j++) {
+			struct ldb_dn *dn = ldb_dn_from_ldb_val(ac, module->ldb, &el->values[j]);
+			if (!dn || !ldb_dn_validate(dn)) {
+				ldb_asprintf_errstring(module->ldb, 
+						       "could not parse attribute %s as a DN", el->name);
+				return LDB_ERR_INVALID_DN_SYNTAX;
+			}
+			if (((el->flags & LDB_FLAG_MOD_MASK) == LDB_FLAG_MOD_DELETE) && !ldb_dn_has_extended(dn)) {
+				/* NO need to figure this DN out, it's going to be deleted anyway */
+				continue;
+			}
+			ret = extended_store_replace(ac, req->op.mod.message->elements, &el->values[j]);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+		}
+	}
+
+	/* if DNs were set continue */
+	if (ac->ops == NULL) {
+		talloc_free(ac);
+		return ldb_next_request(module, req);
+	}
+
+	/* start with the searches */
+	return ldb_next_request(module, ac->ops->search_req);
+}
+
+_PUBLIC_ const struct ldb_module_ops ldb_extended_dn_store_module_ops = {
+	.name		   = "extended_dn_store",
+	.add               = extended_dn_add,
+	.modify            = extended_dn_modify,
+};
diff --git a/source4/dsdb/samdb/samdb.h b/source4/dsdb/samdb/samdb.h
index 570221ee25..efc467865c 100644
--- a/source4/dsdb/samdb/samdb.h
+++ b/source4/dsdb/samdb/samdb.h
@@ -59,6 +59,11 @@ struct dsdb_control_current_partition {
 #define DSDB_CONTROL_REPLICATED_UPDATE_OID "1.3.6.1.4.1.7165.4.3.3"
 /* DSDB_CONTROL_REPLICATED_UPDATE_OID has NULL data */
 
+#define DSDB_CONTROL_DN_STORAGE_FORMAT_OID "1.3.6.1.4.1.7165.4.3.4"
+/* DSDB_CONTROL_DN_STORAGE_FORMAT_OID has NULL data and behaves very
+ * much like LDB_CONTROL_EXTENDED_DN_OID when the DB stores an
+ * extended DN, and otherwise returns normal DNs */
+
 #define DSDB_EXTENDED_REPLICATED_OBJECTS_OID "1.3.6.1.4.1.7165.4.4.1"
 struct dsdb_extended_replicated_object {
 	struct ldb_message *msg;