/* 
   Unix SMB/CIFS mplementation.

   The module that handles the Schema checkings and dynamic attributes
   
   Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009
    
   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/>.
   
*/

#include "includes.h"
#include "ldb_module.h"
#include "dsdb/samdb/samdb.h"
#include "librpc/gen_ndr/ndr_misc.h"
#include "librpc/gen_ndr/ndr_drsuapi.h"
#include "librpc/gen_ndr/ndr_drsblobs.h"
#include "param/param.h"
#include "dsdb/samdb/ldb_modules/util.h"

static int generate_objectClasses(struct ldb_context *ldb, struct ldb_message *msg,
				  const struct dsdb_schema *schema);
static int generate_attributeTypes(struct ldb_context *ldb, struct ldb_message *msg,
				   const struct dsdb_schema *schema);
static int generate_dITContentRules(struct ldb_context *ldb, struct ldb_message *msg,
				    const struct dsdb_schema *schema);
static int generate_extendedAttributeInfo(struct ldb_context *ldb, struct ldb_message *msg,
					  const struct dsdb_schema *schema);
static int generate_extendedClassInfo(struct ldb_context *ldb, struct ldb_message *msg,
				      const struct dsdb_schema *schema);
static int generate_possibleInferiors(struct ldb_context *ldb, struct ldb_message *msg,
				      const struct dsdb_schema *schema);

static const struct {
	const char *attr;
	int (*fn)(struct ldb_context *, struct ldb_message *, const struct dsdb_schema *);
	bool aggregate;
} generated_attrs[] = {
	{
		.attr = "objectClasses",
		.fn = generate_objectClasses,
		.aggregate = true,
	},
	{
		.attr = "attributeTypes",
		.fn = generate_attributeTypes,
		.aggregate = true,
	},
	{
		.attr = "dITContentRules",
		.fn = generate_dITContentRules,
		.aggregate = true,
	},
	{
		.attr = "extendedAttributeInfo",
		.fn = generate_extendedAttributeInfo,
		.aggregate = true,
	},
	{
		.attr = "extendedClassInfo",
		.fn = generate_extendedClassInfo,
		.aggregate = true,
	},
	{
		.attr = "possibleInferiors",
		.fn = generate_possibleInferiors,
		.aggregate = false,
	}
};

struct schema_data_private_data {
	struct ldb_dn *aggregate_dn;
	struct ldb_dn *schema_dn;
};

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

	const struct dsdb_schema *schema;
};

static int schema_data_init(struct ldb_module *module)
{
	struct ldb_context *ldb;
	struct ldb_dn *schema_dn;
	int ret;
	struct schema_data_private_data *data;

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

	ldb = ldb_module_get_ctx(module);
	schema_dn = ldb_get_schema_basedn(ldb);
	if (!schema_dn) {
		ldb_reset_err_string(ldb);
		ldb_debug(ldb, LDB_DEBUG_WARNING,
			  "schema_data_init: no schema dn present: (skip schema loading)\n");
		return LDB_SUCCESS;
	}

	data = talloc(module, struct schema_data_private_data);
	if (data == NULL) {
		return ldb_oom(ldb);
	}

	data->schema_dn = schema_dn;

	/* Used to check to see if this is a result on the CN=Aggregate schema */
	data->aggregate_dn = samdb_aggregate_schema_dn(ldb, data);
	if (!data->aggregate_dn) {
		ldb_asprintf_errstring(ldb, "schema_data_init: Could not build aggregate schema DN for schema in %s", ldb_dn_get_linearized(schema_dn));
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ldb_module_set_private(module, data);
	return LDB_SUCCESS;
}

static int schema_data_add(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct dsdb_schema *schema;
	const struct ldb_val *attributeID = NULL;
	const struct ldb_val *governsID = NULL;
	const char *oid_attr = NULL;
	const char *oid = NULL;
	struct ldb_dn *parent_dn = NULL;
	int cmp;
	WERROR status;
	bool rodc = false;
	int ret;

	ldb = ldb_module_get_ctx(module);

	/* special objects should always go through */
	if (ldb_dn_is_special(req->op.add.message->dn)) {
		return ldb_next_request(module, req);
	}

	/* replicated update should always go through */
	if (ldb_request_get_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID)) {
		return ldb_next_request(module, req);
	}

	schema = dsdb_get_schema(ldb, req);
	if (!schema) {
		return ldb_next_request(module, req);
	}

	if (schema->base_dn == NULL) {
		ldb_debug_set(ldb, LDB_DEBUG_FATAL,
			  "schema_data_add: base_dn NULL\n");
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = samdb_rodc(ldb, &rodc);
	if (ret != LDB_SUCCESS) {
		DEBUG(4, (__location__ ": unable to tell if we are an RODC \n"));
	}

	if (!schema->fsmo.we_are_master && !rodc) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_add: we are not master: reject request\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	if (!schema->fsmo.update_allowed && !rodc) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_add: updates are not allowed: reject request\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	if (ldb_request_get_control(req, LDB_CONTROL_RELAX_OID)) {
		/*
		 * the provision code needs to create
		 * the schema root object.
		 */
		cmp = ldb_dn_compare(req->op.add.message->dn, schema->base_dn);
		if (cmp == 0) {
			return ldb_next_request(module, req);
		}
	}

	parent_dn = ldb_dn_get_parent(req, req->op.add.message->dn);
	if (!parent_dn) {
		return ldb_oom(ldb);
	}

	cmp = ldb_dn_compare(parent_dn, schema->base_dn);
	if (cmp != 0) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_add: no direct child :%s\n",
			  ldb_dn_get_linearized(req->op.add.message->dn));
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	attributeID = ldb_msg_find_ldb_val(req->op.add.message, "attributeID");
	governsID = ldb_msg_find_ldb_val(req->op.add.message, "governsID");

	if (attributeID) {
		oid_attr = "attributeID";
		oid = talloc_strndup(req, (const char *)attributeID->data, attributeID->length);
	} else if (governsID) {
		oid_attr = "governsID";
		oid = talloc_strndup(req, (const char *)governsID->data, governsID->length);
	} else {
		return ldb_next_request(module, req);
	}

	if (!oid) {
		return ldb_oom(ldb);
	}

	status = dsdb_schema_pfm_find_oid(schema->prefixmap, oid, NULL);
	if (!W_ERROR_IS_OK(status)) {
		/* check for internal errors */
		if (!W_ERROR_EQUAL(status, WERR_NOT_FOUND)) {
			ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			              "schema_data_add: failed to map %s[%s]: %s\n",
			              oid_attr, oid, win_errstr(status));
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}

		/* Update prefixMap and save it */
		status = dsdb_create_prefix_mapping(ldb, schema, oid);
		if (!W_ERROR_IS_OK(status)) {
			ldb_debug_set(ldb, LDB_DEBUG_ERROR,
				  "schema_data_add: failed to create prefix mapping for %s[%s]: %s\n",
				  oid_attr, oid, win_errstr(status));
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}
	}

	return ldb_next_request(module, req);
}

static int schema_data_modify(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct dsdb_schema *schema;
	int cmp;
	bool rodc = false;
	int ret;
	struct ldb_control *sd_propagation_control;

	ldb = ldb_module_get_ctx(module);

	/* special objects should always go through */
	if (ldb_dn_is_special(req->op.mod.message->dn)) {
		return ldb_next_request(module, req);
	}

	/* replicated update should always go through */
	if (ldb_request_get_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID)) {
		return ldb_next_request(module, req);
	}

	/* dbcheck should be able to fix things */
	if (ldb_request_get_control(req, DSDB_CONTROL_DBCHECK)) {
		return ldb_next_request(module, req);
	}

	sd_propagation_control = ldb_request_get_control(req,
					DSDB_CONTROL_SEC_DESC_PROPAGATION_OID);
	if (sd_propagation_control != NULL) {
		if (req->op.mod.message->num_elements != 1) {
			return ldb_module_operr(module);
		}
		ret = strcmp(req->op.mod.message->elements[0].name,
			     "nTSecurityDescriptor");
		if (ret != 0) {
			return ldb_module_operr(module);
		}

		return ldb_next_request(module, req);
	}

	schema = dsdb_get_schema(ldb, req);
	if (!schema) {
		return ldb_next_request(module, req);
	}

	cmp = ldb_dn_compare(req->op.mod.message->dn, schema->base_dn);
	if (cmp == 0) {
		static const char * const constrained_attrs[] = {
			"schemaInfo",
			"prefixMap",
			"msDs-Schema-Extensions",
			"msDS-IntId",
			NULL
		};
		size_t i;
		struct ldb_message_element *el;

		if (ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID)) {
			return ldb_next_request(module, req);
		}

		for (i=0; constrained_attrs[i]; i++) {
			el = ldb_msg_find_element(req->op.mod.message,
						  constrained_attrs[i]);
			if (el == NULL) {
				continue;
			}

			ldb_debug_set(ldb, LDB_DEBUG_ERROR,
				      "schema_data_modify: reject update "
				      "of attribute[%s]\n",
				      constrained_attrs[i]);
			return LDB_ERR_CONSTRAINT_VIOLATION;
		}

		return ldb_next_request(module, req);
	}

	ret = samdb_rodc(ldb, &rodc);
	if (ret != LDB_SUCCESS) {
		DEBUG(4, (__location__ ": unable to tell if we are an RODC \n"));
	}

	if (!schema->fsmo.we_are_master && !rodc) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_modify: we are not master: reject request\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	if (!schema->fsmo.update_allowed && !rodc) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_modify: updates are not allowed: reject request\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	return ldb_next_request(module, req);
}

static int schema_data_del(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb;
	struct dsdb_schema *schema;
	bool rodc = false;
	int ret;

	ldb = ldb_module_get_ctx(module);

	/* special objects should always go through */
	if (ldb_dn_is_special(req->op.del.dn)) {
		return ldb_next_request(module, req);
	}

	/* replicated update should always go through */
	if (ldb_request_get_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID)) {
		return ldb_next_request(module, req);
	}

	/* dbcheck should be able to fix things */
	if (ldb_request_get_control(req, DSDB_CONTROL_DBCHECK)) {
		return ldb_next_request(module, req);
	}

	schema = dsdb_get_schema(ldb, req);
	if (!schema) {
		return ldb_next_request(module, req);
	}

	ret = samdb_rodc(ldb, &rodc);
	if (ret != LDB_SUCCESS) {
		DEBUG(4, (__location__ ": unable to tell if we are an RODC \n"));
	}

	if (!schema->fsmo.we_are_master && !rodc) {
		ldb_debug_set(ldb, LDB_DEBUG_ERROR,
			  "schema_data_modify: we are not master: reject request\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	/*
	 * normaly the DACL will prevent delete
	 * with LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS
	 * above us.
	 */
	ldb_debug_set(ldb, LDB_DEBUG_ERROR,
		      "schema_data_del: delete is not allowed in the schema\n");
	return LDB_ERR_UNWILLING_TO_PERFORM;
}

static int generate_objectClasses(struct ldb_context *ldb, struct ldb_message *msg,
				  const struct dsdb_schema *schema) 
{
	const struct dsdb_class *sclass;
	int ret;

	for (sclass = schema->classes; sclass; sclass = sclass->next) {
		char *v = schema_class_to_description(msg, sclass);
		if (v == NULL) {
			return ldb_oom(ldb);
		}
		ret = ldb_msg_add_steal_string(msg, "objectClasses", v);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}
	return LDB_SUCCESS;
}
static int generate_attributeTypes(struct ldb_context *ldb, struct ldb_message *msg,
				  const struct dsdb_schema *schema) 
{
	const struct dsdb_attribute *attribute;
	int ret;

	for (attribute = schema->attributes; attribute; attribute = attribute->next) {
		char *v = schema_attribute_to_description(msg, attribute);
		if (v == NULL) {
			return ldb_oom(ldb);
		}
		ret = ldb_msg_add_steal_string(msg, "attributeTypes", v);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}
	return LDB_SUCCESS;
}

static int generate_dITContentRules(struct ldb_context *ldb, struct ldb_message *msg,
				    const struct dsdb_schema *schema) 
{
	const struct dsdb_class *sclass;
	int ret;

	for (sclass = schema->classes; sclass; sclass = sclass->next) {
		if (sclass->auxiliaryClass || sclass->systemAuxiliaryClass) {
			char *ditcontentrule = schema_class_to_dITContentRule(msg, sclass, schema);
			if (!ditcontentrule) {
				return ldb_oom(ldb);
			}
			ret = ldb_msg_add_steal_string(msg, "dITContentRules", ditcontentrule);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
		}
	}
	return LDB_SUCCESS;
}

static int generate_extendedAttributeInfo(struct ldb_context *ldb,
					  struct ldb_message *msg,
					  const struct dsdb_schema *schema)
{
	const struct dsdb_attribute *attribute;
	int ret;

	for (attribute = schema->attributes; attribute; attribute = attribute->next) {
		char *val = schema_attribute_to_extendedInfo(msg, attribute);
		if (!val) {
			return ldb_oom(ldb);
		}

		ret = ldb_msg_add_steal_string(msg, "extendedAttributeInfo", val);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return LDB_SUCCESS;
}

static int generate_extendedClassInfo(struct ldb_context *ldb,
				      struct ldb_message *msg,
				      const struct dsdb_schema *schema)
{
	const struct dsdb_class *sclass;
	int ret;

	for (sclass = schema->classes; sclass; sclass = sclass->next) {
		char *val = schema_class_to_extendedInfo(msg, sclass);
		if (!val) {
			return ldb_oom(ldb);
		}

		ret = ldb_msg_add_steal_string(msg, "extendedClassInfo", val);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return LDB_SUCCESS;
}


static int generate_possibleInferiors(struct ldb_context *ldb, struct ldb_message *msg,
				      const struct dsdb_schema *schema) 
{
	struct ldb_dn *dn = msg->dn;
	unsigned int i;
	int ret;
	const char *first_component_name = ldb_dn_get_component_name(dn, 0);
	const struct ldb_val *first_component_val;
	const struct dsdb_class *schema_class;
	const char **possibleInferiors;

	if (strcasecmp(first_component_name, "cn") != 0) {
		return LDB_SUCCESS;
	}

	first_component_val = ldb_dn_get_component_val(dn, 0);

	schema_class = dsdb_class_by_cn_ldb_val(schema, first_component_val);
	if (schema_class == NULL) {
		return LDB_SUCCESS;
	}
	
	possibleInferiors = schema_class->possibleInferiors;
	if (possibleInferiors == NULL) {
		return LDB_SUCCESS;
	}

	for (i=0;possibleInferiors[i];i++) {
		char *v = talloc_strdup(msg, possibleInferiors[i]);
		if (v == NULL) {
			return ldb_oom(ldb);
		}
		ret = ldb_msg_add_steal_string(msg, "possibleInferiors", v);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return LDB_SUCCESS;
}


/* Add objectClasses, attributeTypes and dITContentRules from the
   schema object (they are not stored in the database)
 */
static int schema_data_search_callback(struct ldb_request *req, struct ldb_reply *ares)
{
	struct ldb_context *ldb;
	struct schema_data_search_data *ac;
	struct schema_data_private_data *mc;
	unsigned int i;
	int ret;

	ac = talloc_get_type(req->context, struct schema_data_search_data);
	mc = talloc_get_type(ldb_module_get_private(ac->module), struct schema_data_private_data);
	ldb = ldb_module_get_ctx(ac->module);

	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);
	}
	/* Only entries are interesting, and we handle the case of the parent seperatly */

	switch (ares->type) {
	case LDB_REPLY_ENTRY:

		if (ldb_dn_compare(ares->message->dn, mc->aggregate_dn) == 0) {
			for (i=0; i < ARRAY_SIZE(generated_attrs); i++) {
				if (generated_attrs[i].aggregate &&
				    ldb_attr_in_list(ac->req->op.search.attrs, generated_attrs[i].attr)) {
					ret = generated_attrs[i].fn(ldb, ares->message, ac->schema);
					if (ret != LDB_SUCCESS) {
						return ret;
					}
				}
			}
		} else if ((ldb_dn_compare_base(mc->schema_dn, ares->message->dn) == 0)
			   && (ldb_dn_compare(mc->schema_dn, ares->message->dn) != 0)) {
			for (i=0; i < ARRAY_SIZE(generated_attrs); i++) {
				if (!generated_attrs[i].aggregate &&
				    ldb_attr_in_list(ac->req->op.search.attrs, generated_attrs[i].attr)) {
					ret = generated_attrs[i].fn(ldb, ares->message, ac->schema);
					if (ret != LDB_SUCCESS) {
						return 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, ares->error);
	}

	return LDB_SUCCESS;
}

/* search */
static int schema_data_search(struct ldb_module *module, struct ldb_request *req)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	unsigned int i;
	int ret;
	struct schema_data_search_data *search_context;
	struct ldb_request *down_req;
	const struct dsdb_schema *schema;
	if (!ldb_module_get_private(module)) {
		/* If there is no module data, there is little we can do */
		return ldb_next_request(module, req);
	}

	/* The schema manipulation does not apply to special DNs */
	if (ldb_dn_is_special(req->op.search.base)) {
		return ldb_next_request(module, req);
	}

	for (i=0; i < ARRAY_SIZE(generated_attrs); i++) {
		if (ldb_attr_in_list(req->op.search.attrs, generated_attrs[i].attr)) {
			break;
		}
	}
	if (i == ARRAY_SIZE(generated_attrs)) {
		/* No request for a generated attr found, nothing to
		 * see here, move along... */
		return ldb_next_request(module, req);
	}

	schema = dsdb_get_schema(ldb, NULL);
	if (!schema || !ldb_module_get_private(module)) {
		/* If there is no schema, there is little we can do */
		return ldb_next_request(module, req);
	}

	search_context = talloc(req, struct schema_data_search_data);
	if (!search_context) {
		return ldb_oom(ldb);
	}

	search_context->module = module;
	search_context->req = req;
	search_context->schema = talloc_reference(search_context, schema);
	if (!search_context->schema) {
		return ldb_oom(ldb);
	}

	ret = ldb_build_search_req_ex(&down_req, ldb, search_context,
					req->op.search.base,
					req->op.search.scope,
					req->op.search.tree,
					req->op.search.attrs,
					req->controls,
					search_context, schema_data_search_callback,
					req);
	LDB_REQ_SET_LOCATION(down_req);
	if (ret != LDB_SUCCESS) {
		return ldb_operr(ldb);
	}

	return ldb_next_request(module, down_req);
}


static const struct ldb_module_ops ldb_schema_data_module_ops = {
	.name		= "schema_data",
	.init_context	= schema_data_init,
	.add		= schema_data_add,
	.modify		= schema_data_modify,
	.del		= schema_data_del,
	.search         = schema_data_search
};

int ldb_schema_data_module_init(const char *version)
{
	LDB_MODULE_CHECK_VERSION(version);
	return ldb_register_module(&ldb_schema_data_module_ops);
}