repl_meta_data.c

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/* 
   ldb database library

   Copyright (C) Simo Sorce  2004-2006
   Copyright (C) Andrew Bartlett <[e-mail]> 2005
   Copyright (C) Andrew Tridgell 2005
   Copyright (C) Stefan Metzmacher <[e-mail]> 2007

     ** 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 repl_meta_data module
 *
 *  Description: - add a unique objectGUID onto every new record,
 *               - handle whenCreated, whenChanged timestamps
 *               - handle uSNCreated, uSNChanged numbers
 *               - handle replPropertyMetaData attribute
 *
 *  Author: Simo Sorce
 *  Author: Stefan Metzmacher
 */

#include "includes.h"
#include "lib/ldb/include/ldb.h"
#include "lib/ldb/include/ldb_errors.h"
#include "lib/ldb/include/ldb_private.h"
#include "dsdb/samdb/samdb.h"
#include "dsdb/common/flags.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"

struct replmd_replicated_request {
	struct ldb_module *module;
	struct ldb_handle *handle;
	struct ldb_request *orig_req;

	const struct dsdb_schema *schema;

	struct dsdb_extended_replicated_objects *objs;

	uint32_t index_current;

	struct {
		TALLOC_CTX *mem_ctx;
		struct ldb_request *search_req;
		struct ldb_message *search_msg;
		int search_ret;
		struct ldb_request *change_req;
		int change_ret;
	} sub;
};

static struct replmd_replicated_request *replmd_replicated_init_handle(struct ldb_module *module,
								       struct ldb_request *req,
								       struct dsdb_extended_replicated_objects *objs)
{
	struct replmd_replicated_request *ar;
	struct ldb_handle *h;
	const struct dsdb_schema *schema;

	schema = dsdb_get_schema(module->ldb);
	if (!schema) {
		ldb_debug_set(module->ldb, LDB_DEBUG_FATAL,
			      "replmd_replicated_init_handle: no loaded schema found\n");
		return NULL;
	}

	h = talloc_zero(req, struct ldb_handle);
	if (h == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		return NULL;
	}

	h->module	= module;
	h->state	= LDB_ASYNC_PENDING;
	h->status	= LDB_SUCCESS;

	ar = talloc_zero(h, struct replmd_replicated_request);
	if (ar == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		talloc_free(h);
		return NULL;
	}

	h->private_data	= ar;

	ar->module	= module;
	ar->handle	= h;
	ar->orig_req	= req;
	ar->schema	= schema;
	ar->objs	= objs;

	req->handle = h;

	return ar;
}

/*
  add a time element to a record
*/
static int add_time_element(struct ldb_message *msg, const char *attr, time_t t)
{
	struct ldb_message_element *el;
	char *s;

	if (ldb_msg_find_element(msg, attr) != NULL) {
		return 0;
	}

	s = ldb_timestring(msg, t);
	if (s == NULL) {
		return -1;
	}

	if (ldb_msg_add_string(msg, attr, s) != 0) {
		return -1;
	}

	el = ldb_msg_find_element(msg, attr);
	/* always set as replace. This works because on add ops, the flag
	   is ignored */
	el->flags = LDB_FLAG_MOD_REPLACE;

	return 0;
}

/*
  add a uint64_t element to a record
*/
static int add_uint64_element(struct ldb_message *msg, const char *attr, uint64_t v)
{
	struct ldb_message_element *el;

	if (ldb_msg_find_element(msg, attr) != NULL) {
		return 0;
	}

	if (ldb_msg_add_fmt(msg, attr, "%llu", (unsigned long long)v) != 0) {
		return -1;
	}

	el = ldb_msg_find_element(msg, attr);
	/* always set as replace. This works because on add ops, the flag
	   is ignored */
	el->flags = LDB_FLAG_MOD_REPLACE;

	return 0;
}

static int replmd_replPropertyMetaData1_attid_sort(const struct replPropertyMetaData1 *m1,
						   const struct replPropertyMetaData1 *m2,
						   const uint32_t *rdn_attid)
{
	if (m1->attid == m2->attid) {
		return 0;
	}

	/*
	 * the rdn attribute should be at the end!
	 * so we need to return a value greater than zero
	 * which means m1 is greater than m2
	 */
	if (m1->attid == *rdn_attid) {
		return 1;
	}

	/*
	 * the rdn attribute should be at the end!
	 * so we need to return a value less than zero
	 * which means m2 is greater than m1
	 */
	if (m2->attid == *rdn_attid) {
		return -1;
	}

	return m1->attid - m2->attid;
}

static void replmd_replPropertyMetaDataCtr1_sort(struct replPropertyMetaDataCtr1 *ctr1,
						 const uint32_t *rdn_attid)
{
	ldb_qsort(ctr1->array, ctr1->count, sizeof(struct replPropertyMetaData1),
		  discard_const_p(void, rdn_attid), (ldb_qsort_cmp_fn_t)replmd_replPropertyMetaData1_attid_sort);
}

static int replmd_ldb_message_element_attid_sort(const struct ldb_message_element *e1,
						 const struct ldb_message_element *e2,
						 const struct dsdb_schema *schema)
{
	const struct dsdb_attribute *a1;
	const struct dsdb_attribute *a2;

	/* 
	 * TODO: make this faster by caching the dsdb_attribute pointer
	 *       on the ldb_messag_element
	 */

	a1 = dsdb_attribute_by_lDAPDisplayName(schema, e1->name);
	a2 = dsdb_attribute_by_lDAPDisplayName(schema, e2->name);

	/*
	 * TODO: remove this check, we should rely on e1 and e2 having valid attribute names
	 *       in the schema
	 */
	if (!a1 || !a2) {
		return strcasecmp(e1->name, e2->name);
	}

	return a1->attributeID_id - a2->attributeID_id;
}

static void replmd_ldb_message_sort(struct ldb_message *msg,
				    const struct dsdb_schema *schema)
{
	ldb_qsort(msg->elements, msg->num_elements, sizeof(struct ldb_message_element),
		  discard_const_p(void, schema), (ldb_qsort_cmp_fn_t)replmd_ldb_message_element_attid_sort);
}

static int replmd_prepare_originating(struct ldb_module *module, struct ldb_request *req,
				      struct ldb_dn *dn, const char *fn_name,
				      int (*fn)(struct ldb_module *,
			 			struct ldb_request *,
						const struct dsdb_schema *))
{
	const struct dsdb_schema *schema;
 
	/* do not manipulate our control entries */
	if (ldb_dn_is_special(dn)) {
		return ldb_next_request(module, req);
	}

	schema = dsdb_get_schema(module->ldb);
	if (!schema) {
		ldb_debug_set(module->ldb, LDB_DEBUG_FATAL,
			      "%s: no dsdb_schema loaded",
			      fn_name);
		return LDB_ERR_CONSTRAINT_VIOLATION;
	}

	return fn(module, req, schema);
}

static int replmd_add_originating(struct ldb_module *module,
				  struct ldb_request *req,
				  const struct dsdb_schema *schema)
{
	enum ndr_err_code ndr_err;
	struct ldb_request *down_req;
	struct ldb_message *msg;
	const struct dsdb_attribute *rdn_attr = NULL;
	struct GUID guid;
	struct ldb_val guid_value;
	struct replPropertyMetaDataBlob nmd;
	struct ldb_val nmd_value;
	uint64_t seq_num;
	const struct GUID *our_invocation_id;
	time_t t = time(NULL);
	NTTIME now;
	char *time_str;
	int ret;
	uint32_t i, ni=0;

	ldb_debug(module->ldb, LDB_DEBUG_TRACE, "replmd_add_originating\n");

	if (ldb_msg_find_element(req->op.add.message, "objectGUID")) {
		ldb_debug_set(module->ldb, LDB_DEBUG_ERROR,
			      "replmd_add_originating: it's not allowed to add an object with objectGUID\n");
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	/* Get a sequence number from the backend */
	ret = ldb_sequence_number(module->ldb, LDB_SEQ_NEXT, &seq_num);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	/* a new GUID */
	guid = GUID_random();

	/* get our invicationId */
	our_invocation_id = samdb_ntds_invocation_id(module->ldb);
	if (!our_invocation_id) {
		ldb_debug_set(module->ldb, LDB_DEBUG_ERROR,
			      "replmd_add_originating: unable to find invocationId\n");
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* create a copy of the request */
	down_req = talloc(req, struct ldb_request);
	if (down_req == NULL) {
		ldb_oom(module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	*down_req = *req;

	/* we have to copy the message as the caller might have it as a const */
	down_req->op.add.message = msg = ldb_msg_copy_shallow(down_req, req->op.add.message);
	if (msg == NULL) {
		talloc_free(down_req);
		ldb_oom(module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* generated times */
	unix_to_nt_time(&now, t);
	time_str = ldb_timestring(msg, t);
	if (!time_str) {
		talloc_free(down_req);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* 
	 * remove autogenerated attributes
	 */
	ldb_msg_remove_attr(msg, "whenCreated");
	ldb_msg_remove_attr(msg, "whenChanged");
	ldb_msg_remove_attr(msg, "uSNCreated");
	ldb_msg_remove_attr(msg, "uSNChanged");
	ldb_msg_remove_attr(msg, "replPropertyMetaData");

	/*
	 * readd replicated attributes
	 */
	ret = ldb_msg_add_string(msg, "whenCreated", time_str);
	if (ret != LDB_SUCCESS) {
		talloc_free(down_req);
		ldb_oom(module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* build the replication meta_data */
	ZERO_STRUCT(nmd);
	nmd.version		= 1;
	nmd.ctr.ctr1.count	= msg->num_elements;
	nmd.ctr.ctr1.array	= talloc_array(msg,
					       struct replPropertyMetaData1,
					       nmd.ctr.ctr1.count);
	if (!nmd.ctr.ctr1.array) {
		talloc_free(down_req);
		ldb_oom(module->ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	for (i=0; i < msg->num_elements; i++) {
		struct ldb_message_element *e = &msg->elements[i];
		struct replPropertyMetaData1 *m = &nmd.ctr.ctr1.array[ni];
		const struct dsdb_attribute *sa;

		if (e->name[0] == '@') continue;

		sa = dsdb_attribute_by_lDAPDisplayName(schema, e->name);
		if (!sa) {
			ldb_debug_set(module->ldb, LDB_DEBUG_ERROR,
				      "replmd_add_originating: attribute '%s' not defined in schema\n",
				      e->name);
			talloc_free(down_req);
			return LDB_ERR_NO_SUCH_ATTRIBUTE;
		}

		if ((sa->systemFlags & 0x00000001) || (sa->systemFlags & 0x00000004)) {
			/* if the attribute is not replicated (0x00000001)
			 * or constructed (0x00000004) it has no metadata
			 */
			continue;
		}

		m->attid			= sa->attributeID_id;
		m->version			= 1;
		m->originating_change_time	= now;
		m->originating_invocation_id	= *our_invocation_id;
		m->originating_usn		= seq_num;
		m->local_usn			= seq_num;
		ni++;

		if (ldb_attr_cmp(e->name, ldb_dn_get_rdn_name(msg->dn))) {
			rdn_attr = sa;
		}
	}