/* 
   ldb database library

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006-2007
   Copyright (C) Andrew Tridgell <tridge@samba.org> 2009
   Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
   Copyright (C) Simo Sorce <idra@samba.org> 2008
   Copyright (C) Matthias Dieter Wallnöfer 2010

   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 subtree delete module
 *
 *  Description: Delete of a subtree in LDB
 *
 *  Author: Andrew Bartlett
 */

#include "includes.h"
#include <ldb.h>
#include <ldb_module.h>
#include "dsdb/samdb/ldb_modules/util.h"
#include "dsdb/common/util.h"


static int subtree_delete_sort(struct ldb_message **m1,
			       struct ldb_message **m2,
			       void *private_data)
{
	struct ldb_dn *dn1 = (*m1)->dn;
	struct ldb_dn *dn2 = (*m2)->dn;

	/*
	 * This sorts in tree order, children first
	 */
	return ldb_dn_compare(dn1, dn2);
}

static int subtree_delete(struct ldb_module *module, struct ldb_request *req)
{
	static const char * const attrs[] = { NULL };
	struct ldb_result *res = NULL;
	uint32_t flags;
	unsigned int i;
	int ret;

	if (ldb_dn_is_special(req->op.del.dn)) {
		/* do not manipulate our control entries */
		return ldb_next_request(module, req);
	}

	/* see if we have any children */
	ret = dsdb_module_search(module, req, &res, req->op.del.dn,
				 LDB_SCOPE_ONELEVEL, attrs,
				 DSDB_FLAG_NEXT_MODULE,
				 req,
				 "(objectClass=*)");
	if (ret != LDB_SUCCESS) {
		talloc_free(res);
		return ret;
	}
	if (res->count == 0) {
		talloc_free(res);
		return ldb_next_request(module, req);
	}

	if (ldb_request_get_control(req, LDB_CONTROL_TREE_DELETE_OID) == NULL) {
		/* Do not add any DN outputs to this error string!
		 * Some MMC consoles (eg release 2000) have a strange
		 * bug and prevent subtree deletes afterwards. */
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "subtree_delete: Unable to "
				       "delete a non-leaf node "
				       "(it has %u children)!",
				       res->count);
		talloc_free(res);
		return LDB_ERR_NOT_ALLOWED_ON_NON_LEAF;
	}

	/*
	 * First we sort the results from the leaf to the root
	 */
	LDB_TYPESAFE_QSORT(res->msgs, res->count, NULL,
			   subtree_delete_sort);

	/*
	 * we need to start from the top since other LDB modules could
	 * enforce constraints (eg "objectclass" and "samldb" do so).
	 *
	 * We pass DSDB_FLAG_AS_SYSTEM as the acl module above us
	 * has already checked for SEC_ADS_DELETE_TREE.
	 */
	flags = DSDB_FLAG_TOP_MODULE |
		DSDB_FLAG_AS_SYSTEM |
		DSDB_FLAG_TRUSTED |
		DSDB_TREE_DELETE;
	if (ldb_request_get_control(req, LDB_CONTROL_RELAX_OID) != NULL) {
		flags |= DSDB_MODIFY_RELAX;
	}

	for (i = 0; i < res->count; i++) {
		ret = dsdb_module_del(module, res->msgs[i]->dn, flags, req);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	talloc_free(res);

	return ldb_next_request(module, req);
}

static int subtree_delete_init(struct ldb_module *module)
{
	struct ldb_context *ldb;
	int ret;

	ldb = ldb_module_get_ctx(module);

	ret = ldb_mod_register_control(module, LDB_CONTROL_TREE_DELETE_OID);
	if (ret != LDB_SUCCESS) {
		ldb_debug(ldb, LDB_DEBUG_ERROR,
			"subtree_delete: Unable to register control with rootdse!\n");
		return ldb_operr(ldb);
	}

	return ldb_next_init(module);
}

static const struct ldb_module_ops ldb_subtree_delete_module_ops = {
	.name		   = "subtree_delete",
	.init_context      = subtree_delete_init,
	.del               = subtree_delete
};

int ldb_subtree_delete_module_init(const char *version)
{
	LDB_MODULE_CHECK_VERSION(version);
	return ldb_register_module(&ldb_subtree_delete_module_ops);
}