/* 
   ldb database library

   Copyright (C) Simo Sorce  2005

     ** 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/*
 *  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 "dsdb/samdb/samdb.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 BOOL inject_extended_dn(struct ldb_message *msg,
				int type,
				BOOL remove_guid,
				BOOL remove_sid)
{
	const struct ldb_val *val;
	struct GUID guid;
	struct dom_sid *sid;
	char *object_guid;
	char *object_sid;
	char *new_dn, *dn;

	dn = ldb_dn_linearize(msg, msg->dn);
	if (!dn)
		return False;

	/* retrieve object_guid */
	guid = samdb_result_guid(msg, "objectGUID");
	object_guid = GUID_string(msg, &guid);
	if (!object_guid)
		return False;

	if (remove_guid)
		ldb_msg_remove_attr(msg, "objectGUID");

	/* 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 False;

		if (remove_sid)
			ldb_msg_remove_attr(msg, "objectSID");
	}

	/* TODO: handle type */
	switch (type) {
		case 0:
		case 1:
			if (object_sid) {
				new_dn = talloc_asprintf(msg, "<GUID=%s>;<SID=%s>;%s",
							 object_guid, object_sid, dn);
			} else {
				new_dn = talloc_asprintf(msg, "<GUID=%s>;%s",
							 object_guid, dn);
			}
			break;
		default:
			return False;
	}

	if (!new_dn)
		return False;

	msg->dn = ldb_dn_explode_or_special(msg, new_dn);
	if (!msg->dn)
		return False;

	val = ldb_msg_find_ldb_val(msg, "distinguishedName");
	if (val) {
		ldb_msg_remove_attr(msg, "distinguishedName");
		if (ldb_msg_add_string(msg, "distinguishedName", new_dn))
			return False;
	}

	return True;
}

/* search */
static int extended_search(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_result *extended_result;
	struct ldb_control *control;
	struct ldb_control **saved_controls;
	struct ldb_extended_dn_control *extended_ctrl;
	int i, ret;
	const char * const *saved_attrs = NULL;
	char **new_attrs;
	BOOL remove_guid = False;
	BOOL remove_sid = False;

	/* check if there's a paged request control */
	control = get_control_from_list(req->controls, LDB_CONTROL_EXTENDED_DN_OID);
	if (control == NULL) {
		/* not found go on */
		return ldb_next_request(module, req);
	}

	extended_ctrl = talloc_get_type(control->data, struct ldb_extended_dn_control);

	/* save it locally and remove it from the list */
	if (!save_controls(control, req, &saved_controls)) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
		
	/* 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")) {
			remove_guid = True;
		}
		if (! is_attr_in_list(req->op.search.attrs, "objectSID")) {
			remove_sid = True;
		}
		if (remove_guid || remove_sid) {
			new_attrs = copy_attrs(req, req->op.search.attrs);
			if (!new_attrs)
				return LDB_ERR_OPERATIONS_ERROR;
			
			saved_attrs = req->op.search.attrs;

			if (remove_guid) {
				if (!add_attrs(req, &new_attrs, "objectGUID"))
					return LDB_ERR_OPERATIONS_ERROR;
			}
			if (remove_sid) {
				if (!add_attrs(req, &new_attrs, "objectSID"))
					return LDB_ERR_OPERATIONS_ERROR;
			}

			req->op.search.attrs = (const char * const *)new_attrs;
		}
	}

	ret = ldb_next_request(module, req);

	/* put request back into original shape */
	/* TODO: build a new req and don't touch the original one */

	if (req->controls) talloc_free(req->controls);
	req->controls = saved_controls;

	if (saved_attrs) {
		talloc_free(new_attrs);
		req->op.search.attrs = saved_attrs;
	}

	if (ret != LDB_SUCCESS) {
		return ret;
	}

	extended_result = req->op.search.res;
	
	for (i = 0; i < extended_result->count; i++) {
		/* TODO: the following funtion updates only dn and
		 * distinguishedName. We still need to address other
		 * DN entries like objectCategory
		 */
		if (!inject_extended_dn(extended_result->msgs[i], 
					extended_ctrl->type,
					remove_guid, remove_sid)) {
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}
	
	return LDB_SUCCESS;	
}

static int extended_request(struct ldb_module *module, struct ldb_request *req)
{
	switch (req->operation) {

	case LDB_REQ_SEARCH:
		return extended_search(module, req);

	default:
		return ldb_next_request(module, req);

	}
}

static const struct ldb_module_ops extended_dn_ops = {
	.name		   = "extended_dn",
	.request      	   = extended_request,
};

#ifdef HAVE_DLOPEN_DISABLED
struct ldb_module *init_module(struct ldb_context *ldb, int stage, const char *options[])
#else
struct ldb_module *extended_dn_module_init(struct ldb_context *ldb, int stage, const char *options[])
#endif
{
	struct ldb_module *ctx;

	if (stage == LDB_MODULES_INIT_STAGE_2) {
		struct ldb_request request;
		int ret;

		request.operation = LDB_REQ_REGISTER;
		request.op.reg.oid = LDB_CONTROL_EXTENDED_DN_OID;
		request.controls = NULL;

		ret = ldb_request(ldb, &request);
		if (ret != LDB_SUCCESS) {
			ldb_debug(ldb, LDB_DEBUG_ERROR, "extended_dn: Unable to register control with rootdse!\n");
		}

		return NULL;
	}

	ctx = talloc(ldb, struct ldb_module);
	if (!ctx)
		return NULL;

	ctx->ldb = ldb;
	ctx->prev = ctx->next = NULL;
	ctx->ops = &extended_dn_ops;
	ctx->private_data = NULL;

	return ctx;
}