/*
   ldb database library

   Copyright (C) Andrew Bartlett 2005-2009
   Copyright (C) Simo Sorce 2006-2008

     ** 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: rdn_name
 *
 *  Component: ldb rdn name module
 *
 *  Description: keep a consistent name attribute on objects manpulations
 *
 *  Author: Andrew Bartlett
 *
 *  Modifications:
 *    - made the module async
 *      Simo Sorce Mar 2006
 */

#include "replace.h"
#include "system/filesys.h"
#include "system/time.h"
#include "ldb_module.h"

struct rename_context {
	struct ldb_module *module;
	struct ldb_request *req;

	struct ldb_reply *ares;
};

static int rdn_name_add_callback(struct ldb_request *req,
				 struct ldb_reply *ares)
{
	struct rename_context *ac;

	ac = talloc_get_type(req->context, struct rename_context);

	if (!ares) {
		return ldb_module_done(ac->req, NULL, NULL,
					LDB_ERR_OPERATIONS_ERROR);
	}

	if (ares->type == LDB_REPLY_REFERRAL) {
		return ldb_module_send_referral(ac->req, ares->referral);
	}

	if (ares->error != LDB_SUCCESS) {
		return ldb_module_done(ac->req, ares->controls,
					ares->response, ares->error);
	}

	if (ares->type != LDB_REPLY_DONE) {
		return ldb_module_done(ac->req, NULL, NULL,
					LDB_ERR_OPERATIONS_ERROR);
	}

	return ldb_module_done(ac->req, ares->controls,
					ares->response, LDB_SUCCESS);
}

static int rdn_name_add(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct ldb_request *down_req;
	struct rename_context *ac;
	struct ldb_message *msg;
	struct ldb_message_element *attribute;
	const struct ldb_schema_attribute *a;
	const char *rdn_name;
	const struct ldb_val *rdn_val_p;
	struct ldb_val rdn_val;
	unsigned int i;
	int ret;

	ldb = ldb_module_get_ctx(module);

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

	ac = talloc_zero(req, struct rename_context);
	if (ac == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->module = module;
	ac->req = req;

	msg = ldb_msg_copy_shallow(req, req->op.add.message);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	rdn_name = ldb_dn_get_rdn_name(msg->dn);
	if (rdn_name == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	rdn_val_p = ldb_dn_get_rdn_val(msg->dn);
	if (rdn_val_p == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	if (rdn_val_p->length == 0) {
		ldb_asprintf_errstring(ldb, "Empty RDN value on %s not permitted!",
				       ldb_dn_get_linearized(req->op.add.message->dn));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}
	rdn_val = ldb_val_dup(msg, rdn_val_p);

	/* Perhaps someone above us tried to set this? Then ignore it */
	ldb_msg_remove_attr(msg, "name");

	ret = ldb_msg_add_value(msg, "name", &rdn_val, NULL);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	a = ldb_schema_attribute_by_name(ldb, rdn_name);
	if (a == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	attribute = ldb_msg_find_element(msg, rdn_name);
	if (!attribute) {
		/* add entry with normalised RDN information if possible */
		if (a->name != NULL && strcmp(a->name, "*") != 0) {
			ret = ldb_msg_add_value(msg, a->name, &rdn_val, NULL);
		} else {
			ret = ldb_msg_add_value(msg, rdn_name, &rdn_val, NULL);
		}
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	} else {
		/* normalise attribute name if possible */
		if (a->name != NULL && strcmp(a->name, "*") != 0) {
			attribute->name = a->name;
		}
		/* normalise attribute value */
		for (i = 0; i < attribute->num_values; i++) {
			bool matched;
			if (a->syntax->operator_fn) {
				ret = a->syntax->operator_fn(ldb, LDB_OP_EQUALITY, a,
							     &rdn_val, &attribute->values[i], &matched);
				if (ret != LDB_SUCCESS) return ret;
			} else {
				matched = (a->syntax->comparison_fn(ldb, msg,
								    &rdn_val, &attribute->values[i]) == 0);
			}
			if (matched) {
				/* overwrite so it matches in case */
				attribute->values[i] = rdn_val;
				break;
			}
		}
		if (i == attribute->num_values) {
			char *rdn_errstring = talloc_asprintf(ac,
				"RDN mismatch on %s: %s (%.*s) should match one of:",
				ldb_dn_get_linearized(msg->dn), rdn_name,
				(int)rdn_val.length, (const char *)rdn_val.data);
			for (i = 0; i < attribute->num_values; i++) {
				talloc_asprintf_addbuf(
					&rdn_errstring, " (%.*s)",
					(int)attribute->values[i].length,
					(const char *)attribute->values[i].data);
			}
			ldb_set_errstring(ldb, rdn_errstring);
			/* Match AD's error here */
			return LDB_ERR_INVALID_DN_SYNTAX;
		}
	}

	ret = ldb_build_add_req(&down_req, ldb, req,
				msg,
				req->controls,
				ac, rdn_name_add_callback,
				req);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	talloc_steal(down_req, msg);

	/* go on with the call chain */
	return ldb_next_request(module, down_req);
}

static int rdn_modify_callback(struct ldb_request *req, struct ldb_reply *ares)
{
	struct rename_context *ac;

	ac = talloc_get_type(req->context, struct rename_context);

	if (!ares) {
		return ldb_module_done(ac->req, NULL, NULL,
					LDB_ERR_OPERATIONS_ERROR);
	}

	if (ares->type == LDB_REPLY_REFERRAL) {
		return ldb_module_send_referral(ac->req, ares->referral);
	}

	if (ares->error != LDB_SUCCESS) {
		return ldb_module_done(ac->req, ares->controls,
					ares->response, ares->error);
	}

	/* the only supported reply right now is a LDB_REPLY_DONE */
	if (ares->type != LDB_REPLY_DONE) {
		return ldb_module_done(ac->req, NULL, NULL,
					LDB_ERR_OPERATIONS_ERROR);
	}

	/* send saved controls eventually */
	return ldb_module_done(ac->req, ac->ares->controls,
				ac->ares->response, LDB_SUCCESS);
}

static int rdn_rename_callback(struct ldb_request *req, struct ldb_reply *ares)
{
	struct ldb_context *ldb;
	struct rename_context *ac;
	struct ldb_request *mod_req;
	const char *rdn_name;
	const struct ldb_schema_attribute *a = NULL;
	const struct ldb_val *rdn_val_p;
	struct ldb_val rdn_val;
	struct ldb_message *msg;
	int ret;

	ac = talloc_get_type(req->context, struct rename_context);
	ldb = ldb_module_get_ctx(ac->module);

	if (!ares) {
		goto error;
	}

	if (ares->type == LDB_REPLY_REFERRAL) {
		return ldb_module_send_referral(ac->req, ares->referral);
	}

	if (ares->error != LDB_SUCCESS) {
		return ldb_module_done(ac->req, ares->controls,
					ares->response, ares->error);
	}

	/* the only supported reply right now is a LDB_REPLY_DONE */
	if (ares->type != LDB_REPLY_DONE) {
		goto error;
	}

	/* save reply for caller */
	ac->ares = talloc_steal(ac, ares);

	msg = ldb_msg_new(ac);
	if (msg == NULL) {
		goto error;
	}
	msg->dn = ldb_dn_copy(msg, ac->req->op.rename.newdn);
	if (msg->dn == NULL) {
		goto error;
	}

	rdn_name = ldb_dn_get_rdn_name(ac->req->op.rename.newdn);
	if (rdn_name == NULL) {
		goto error;
	}

	a = ldb_schema_attribute_by_name(ldb, rdn_name);
	if (a == NULL) {
		goto error;
	}

	if (a->name != NULL && strcmp(a->name, "*") != 0) {
		rdn_name = a->name;
	}

	rdn_val_p = ldb_dn_get_rdn_val(msg->dn);
	if (rdn_val_p == NULL) {
		goto error;
	}
	if (rdn_val_p->length == 0) {
		ldb_asprintf_errstring(ldb, "Empty RDN value on %s not permitted!",
				       ldb_dn_get_linearized(req->op.rename.olddn));
		return ldb_module_done(ac->req, NULL, NULL,
				       LDB_ERR_NAMING_VIOLATION);
	}
	rdn_val = ldb_val_dup(msg, rdn_val_p);

	if (ldb_msg_append_value(msg, rdn_name, &rdn_val, LDB_FLAG_MOD_REPLACE) != 0) {
		goto error;
	}
	if (ldb_msg_append_value(msg, "name", &rdn_val, LDB_FLAG_MOD_REPLACE) != 0) {
		goto error;
	}

	ret = ldb_build_mod_req(&mod_req, ldb,
				ac, msg, NULL,
				ac, rdn_modify_callback,
				req);
	if (ret != LDB_SUCCESS) {
		return ldb_module_done(ac->req, NULL, NULL, ret);
	}
	talloc_steal(mod_req, msg);

	/* go on with the call chain */
	return ldb_next_request(ac->module, mod_req);

error:
	return ldb_module_done(ac->req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
}

static int rdn_name_rename(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct rename_context *ac;
	struct ldb_request *down_req;
	int ret;

	ldb = ldb_module_get_ctx(module);

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

	ac = talloc_zero(req, struct rename_context);
	if (ac == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->module = module;
	ac->req = req;

	ret = ldb_build_rename_req(&down_req,
				   ldb,
				   ac,
				   req->op.rename.olddn,
				   req->op.rename.newdn,
				   req->controls,
				   ac,
				   rdn_rename_callback,
				   req);

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

	/* rename first, modify "name" if rename is ok */
	return ldb_next_request(module, down_req);
}

static int rdn_recalculate_callback(struct ldb_request *req, struct ldb_reply *ares)
{
	struct ldb_request *up_req = talloc_get_type(req->context, struct ldb_request);

	talloc_steal(up_req, req);
	return up_req->callback(up_req, ares);
}

static int rdn_name_modify(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	const struct ldb_val *rdn_val_p;
	struct ldb_message_element *e = NULL;
	struct ldb_control *recalculate_rdn_control = NULL;

	ldb = ldb_module_get_ctx(module);

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

	recalculate_rdn_control = ldb_request_get_control(req,
					LDB_CONTROL_RECALCULATE_RDN_OID);
	if (recalculate_rdn_control != NULL) {
		struct ldb_message *msg = NULL;
		const char *rdn_name = NULL;
		struct ldb_val rdn_val;
		const struct ldb_schema_attribute *a = NULL;
		struct ldb_request *mod_req = NULL;
		int ret;
		struct ldb_message_element *rdn_del = NULL;
		struct ldb_message_element *name_del = NULL;

		recalculate_rdn_control->critical = false;

		msg = ldb_msg_copy_shallow(req, req->op.mod.message);
		if (msg == NULL) {
			return ldb_module_oom(module);
		}

		/*
		 * The caller must pass a dummy 'name' attribute
		 * in order to bypass some high level checks.
		 *
		 * We just remove it and check nothing is left.
		 */
		ldb_msg_remove_attr(msg, "name");

		if (msg->num_elements != 0) {
			return ldb_module_operr(module);
		}

		rdn_name = ldb_dn_get_rdn_name(msg->dn);
		if (rdn_name == NULL) {
			return ldb_module_oom(module);
		}

		a = ldb_schema_attribute_by_name(ldb, rdn_name);
		if (a == NULL) {
			return ldb_module_operr(module);
		}

		if (a->name != NULL && strcmp(a->name, "*") != 0) {
			rdn_name = a->name;
		}

		rdn_val_p = ldb_dn_get_rdn_val(msg->dn);
		if (rdn_val_p == NULL) {
			return ldb_module_oom(module);
		}
		rdn_val = ldb_val_dup(msg, rdn_val_p);
		if (rdn_val.length == 0) {
			return ldb_module_oom(module);
		}

		/*
		 * This is a bit tricky:
		 *
		 * We want _DELETE elements (as "rdn_del" and "name_del" without
		 * values) first, followed by _ADD (with the real names)
		 * elements (with values). Then we fix up the "rdn_del" and
		 * "name_del" attributes.
		 */

		ret = ldb_msg_add_empty(msg, "rdn_del", LDB_FLAG_MOD_DELETE, NULL);
		if (ret != 0) {
			return ldb_module_oom(module);
		}
		ret = ldb_msg_append_value(msg, rdn_name, &rdn_val, LDB_FLAG_MOD_ADD);
		if (ret != 0) {
			return ldb_module_oom(module);
		}

		ret = ldb_msg_add_empty(msg, "name_del", LDB_FLAG_MOD_DELETE, NULL);
		if (ret != 0) {
			return ldb_module_oom(module);
		}
		ret = ldb_msg_append_value(msg, "name", &rdn_val, LDB_FLAG_MOD_ADD);
		if (ret != 0) {
			return ldb_module_oom(module);
		}

		rdn_del = ldb_msg_find_element(msg, "rdn_del");
		if (rdn_del == NULL) {
			return ldb_module_operr(module);
		}
		rdn_del->name = talloc_strdup(msg->elements, rdn_name);
		if (rdn_del->name == NULL) {
			return ldb_module_oom(module);
		}
		name_del = ldb_msg_find_element(msg, "name_del");
		if (name_del == NULL) {
			return ldb_module_operr(module);
		}
		name_del->name = talloc_strdup(msg->elements, "name");
		if (name_del->name == NULL) {
			return ldb_module_oom(module);
		}

		ret = ldb_build_mod_req(&mod_req, ldb,
					req, msg, NULL,
					req, rdn_recalculate_callback,
					req);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(req, NULL, NULL, ret);
		}
		talloc_steal(mod_req, msg);

		ret = ldb_request_add_control(mod_req,
					      LDB_CONTROL_RECALCULATE_RDN_OID,
					      false, NULL);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(req, NULL, NULL, ret);
		}
		ret = ldb_request_add_control(mod_req,
					      LDB_CONTROL_PERMISSIVE_MODIFY_OID,
					      false, NULL);
		if (ret != LDB_SUCCESS) {
			return ldb_module_done(req, NULL, NULL, ret);
		}

		/* go on with the call chain */
		return ldb_next_request(module, mod_req);
	}

	rdn_val_p = ldb_dn_get_rdn_val(req->op.mod.message->dn);
	if (rdn_val_p == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	if (rdn_val_p->length == 0) {
		ldb_asprintf_errstring(ldb, "Empty RDN value on %s not permitted!",
				       ldb_dn_get_linearized(req->op.mod.message->dn));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	e = ldb_msg_find_element(req->op.mod.message, "distinguishedName");
	if (e != NULL) {
		ldb_asprintf_errstring(ldb, "Modify of 'distinguishedName' on %s not permitted, must use 'rename' operation instead",
				       ldb_dn_get_linearized(req->op.mod.message->dn));
		if (LDB_FLAG_MOD_TYPE(e->flags) == LDB_FLAG_MOD_REPLACE) {
			return LDB_ERR_CONSTRAINT_VIOLATION;
		} else {
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}
	}

	if (ldb_msg_find_element(req->op.mod.message, "name")) {
		ldb_asprintf_errstring(ldb, "Modify of 'name' on %s not permitted, must use 'rename' operation instead",
				       ldb_dn_get_linearized(req->op.mod.message->dn));
		return LDB_ERR_NOT_ALLOWED_ON_RDN;
	}

	if (ldb_msg_find_element(req->op.mod.message, ldb_dn_get_rdn_name(req->op.mod.message->dn))) {
		ldb_asprintf_errstring(ldb, "Modify of RDN '%s' on %s not permitted, must use 'rename' operation instead",
				       ldb_dn_get_rdn_name(req->op.mod.message->dn), ldb_dn_get_linearized(req->op.mod.message->dn));
		return LDB_ERR_NOT_ALLOWED_ON_RDN;
	}

	/* All OK, they kept their fingers out of the special attributes */
	return ldb_next_request(module, req);
}

static int rdn_name_search(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	const char *rdn_name;
	const struct ldb_val *rdn_val_p;

	ldb = ldb_module_get_ctx(module);

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

	rdn_name = ldb_dn_get_rdn_name(req->op.search.base);
	rdn_val_p = ldb_dn_get_rdn_val(req->op.search.base);
	if ((rdn_name != NULL) && (rdn_val_p == NULL)) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	if ((rdn_val_p != NULL) && (rdn_val_p->length == 0)) {
		ldb_asprintf_errstring(ldb, "Empty RDN value on %s not permitted!",
				       ldb_dn_get_linearized(req->op.search.base));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	return ldb_next_request(module, req);
}

static const struct ldb_module_ops ldb_rdn_name_module_ops = {
	.name              = "rdn_name",
	.add               = rdn_name_add,
	.modify            = rdn_name_modify,
	.rename            = rdn_name_rename,
	.search            = rdn_name_search
};

int ldb_rdn_name_init(const char *version)
{
	LDB_MODULE_CHECK_VERSION(version);
	return ldb_register_module(&ldb_rdn_name_module_ops);
}