Transform the sequence_number operation into a normal extended operation as it should always have been. Make it also async so that it is not a special case.

12 files changed, 412 insertions, 207 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/objectguid.c b/source4/dsdb/samdb/ldb_modules/objectguid.c
index 054905992d..3d725686e7 100644
--- a/source4/dsdb/samdb/ldb_modules/objectguid.c
+++ b/source4/dsdb/samdb/ldb_modules/objectguid.c
@@ -194,7 +194,7 @@ static int objectguid_add(struct ldb_module *module, struct ldb_request *req)
 	}
 
 	/* Get a sequence number from the backend */
-	/* FIXME: ldb_sequence_number is still SYNC now, when this changes,
+	/* FIXME: ldb_sequence_number is a semi-async call,
 	 * make sure this function is split and a callback is used */
 	ret = ldb_sequence_number(module->ldb, LDB_SEQ_NEXT, &seq_num);
 	if (ret == LDB_SUCCESS) {
diff --git a/source4/dsdb/samdb/ldb_modules/partition.c b/source4/dsdb/samdb/ldb_modules/partition.c
index b452b66d56..b4a7a47a23 100644
--- a/source4/dsdb/samdb/ldb_modules/partition.c
+++ b/source4/dsdb/samdb/ldb_modules/partition.c
@@ -115,10 +115,6 @@ int partition_request(struct ldb_module *module, struct ldb_request *request)
 		PARTITION_FIND_OP(module, extended);
 		ret = module->ops->extended(module, request);
 		break;
-	case LDB_SEQUENCE_NUMBER:
-		PARTITION_FIND_OP(module, sequence_number);
-		ret = module->ops->sequence_number(module, request);
-		break;
 	default:
 		PARTITION_FIND_OP(module, request);
 		ret = module->ops->request(module, request);
@@ -716,9 +712,8 @@ static int partition_del_trans(struct ldb_module *module)
 	return ret2;
 }
 
-/* NOTE: ldb_sequence_number is still a completely SYNCHRONOUS call
- * implemented only in ldb_rdb. It does not require ldb_wait() to be
- * called after a request is made */
+
+/* FIXME: This function is still semi-async */
 static int partition_sequence_number(struct ldb_module *module, struct ldb_request *req)
 {
 	int i, ret;
@@ -727,113 +722,241 @@ static int partition_sequence_number(struct ldb_module *module, struct ldb_reque
 	uint64_t timestamp = 0;
 	struct partition_private_data *data = talloc_get_type(module->private_data, 
 							      struct partition_private_data);
+	struct ldb_seqnum_request *seq;
+	struct ldb_seqnum_result *seqr;
+	struct ldb_request *treq;
+	struct ldb_seqnum_request *tseq;
+	struct ldb_seqnum_result *tseqr;
+	struct ldb_extended *ext;
+	struct ldb_result *res;
 
-	switch (req->op.seq_num.type) {
+	seq = talloc_get_type(req->op.extended.data, struct ldb_seqnum_request);
+
+	switch (seq->type) {
 	case LDB_SEQ_NEXT:
 	case LDB_SEQ_HIGHEST_SEQ:
-	       	ret = ldb_next_request(module, req);
-		if (ret != LDB_SUCCESS) {
-			return ret;
+		res = talloc_zero(req, struct ldb_result);
+		if (res == NULL) {
+			return LDB_ERR_OPERATIONS_ERROR;
 		}
-		if (req->op.seq_num.flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
-			timestamp_sequence = req->op.seq_num.seq_num;
-		} else {
-			seq_number = seq_number + req->op.seq_num.seq_num;
+		tseq = talloc_zero(res, struct ldb_seqnum_request);
+		if (tseq == NULL) {
+			talloc_free(res);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		tseq->type = seq->type;
+
+		ret = ldb_build_extended_req(&treq, module->ldb, res,
+					     LDB_EXTENDED_SEQUENCE_NUMBER,
+					     tseq,
+					     NULL,
+					     res,
+					     ldb_extended_default_callback,
+					     NULL);
+	       	ret = ldb_next_request(module, treq);
+		if (ret == LDB_SUCCESS) {
+			ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
 		}
-
-		/* gross hack part1 */
-		ret = ldb_request_add_control(req,
-					DSDB_CONTROL_CURRENT_PARTITION_OID,
-					false, NULL);
 		if (ret != LDB_SUCCESS) {
+			talloc_free(res);
 			return ret;
 		}
+		seqr = talloc_get_type(res->extended->data,
+					struct ldb_seqnum_result);
+		if (seqr->flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
+			timestamp_sequence = seqr->seq_num;
+		} else {
+			seq_number += seqr->seq_num;
+		}
+		talloc_free(res);
 
-		/* Look at base DN */
-		/* Figure out which partition it is under */
 		/* Skip the lot if 'data' isn't here yet (initialistion) */
 		for (i=0; data && data->partitions && data->partitions[i]; i++) {
 
-			/* gross hack part2 */
-			int j;
-			for (j=0; req->controls[j]; j++) {
-				if (strcmp(req->controls[j]->oid, DSDB_CONTROL_CURRENT_PARTITION_OID) == 0) {
-					req->controls[j]->data = data->partitions[i];
-					break;
-				}
+			res = talloc_zero(req, struct ldb_result);
+			if (res == NULL) {
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			tseq = talloc_zero(res, struct ldb_seqnum_request);
+			if (tseq == NULL) {
+				talloc_free(res);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			tseq->type = seq->type;
+
+			ret = ldb_build_extended_req(&treq, module->ldb, res,
+						     LDB_EXTENDED_SEQUENCE_NUMBER,
+						     tseq,
+						     NULL,
+						     res,
+						     ldb_extended_default_callback,
+						     NULL);
+			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
+				return ret;
 			}
 
-			ret = partition_request(data->partitions[i]->module, req);
+			ret = ldb_request_add_control(treq,
+						      DSDB_CONTROL_CURRENT_PARTITION_OID,
+						      false, data->partitions[i]);
 			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
 				return ret;
 			}
-			if (req->op.seq_num.flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
-				timestamp_sequence = MAX(timestamp_sequence, req->op.seq_num.seq_num);
+
+			ret = partition_request(data->partitions[i]->module, treq);
+			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
+				return ret;
+			}
+			ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
+			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
+				return ret;
+			}
+			tseqr = talloc_get_type(res->extended->data,
+						struct ldb_seqnum_result);
+			if (tseqr->flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
+				timestamp_sequence = MAX(timestamp_sequence,
+							 tseqr->seq_num);
 			} else {
-				seq_number = seq_number + req->op.seq_num.seq_num;
+				seq_number += tseqr->seq_num;
 			}
+			talloc_free(res);
 		}
-		/* fall though */
+		/* fall through */
 	case LDB_SEQ_HIGHEST_TIMESTAMP:
-	{
-		struct ldb_request *date_req = talloc(req, struct ldb_request);
-		if (!date_req) {
+
+		res = talloc_zero(req, struct ldb_result);
+		if (res == NULL) {
 			return LDB_ERR_OPERATIONS_ERROR;
 		}
-		*date_req = *req;
-		date_req->op.seq_num.flags = LDB_SEQ_HIGHEST_TIMESTAMP;
 
-		ret = ldb_next_request(module, date_req);
+		tseq = talloc_zero(res, struct ldb_seqnum_request);
+		if (tseq == NULL) {
+			talloc_free(res);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		tseq->type = LDB_SEQ_HIGHEST_TIMESTAMP;
+
+		ret = ldb_build_extended_req(&treq, module->ldb, res,
+					     LDB_EXTENDED_SEQUENCE_NUMBER,
+					     tseq,
+					     NULL,
+					     res,
+					     ldb_extended_default_callback,
+					     NULL);
 		if (ret != LDB_SUCCESS) {
+			talloc_free(res);
 			return ret;
 		}
-		timestamp = date_req->op.seq_num.seq_num;
 
-		/* Look at base DN */
-		/* Figure out which partition it is under */
+		ret = ldb_next_request(module, treq);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(res);
+			return ret;
+		}
+		ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(res);
+			return ret;
+		}
+
+		tseqr = talloc_get_type(res->extended->data,
+					   struct ldb_seqnum_result);
+		timestamp = tseqr->seq_num;
+
+		talloc_free(res);
+
 		/* Skip the lot if 'data' isn't here yet (initialistion) */
 		for (i=0; data && data->partitions && data->partitions[i]; i++) {
 
-			ret = partition_request(data->partitions[i]->module, req);
+			res = talloc_zero(req, struct ldb_result);
+			if (res == NULL) {
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+
+			tseq = talloc_zero(res, struct ldb_seqnum_request);
+			if (tseq == NULL) {
+				talloc_free(res);
+				return LDB_ERR_OPERATIONS_ERROR;
+			}
+			tseq->type = LDB_SEQ_HIGHEST_TIMESTAMP;
+
+			ret = ldb_build_extended_req(&treq, module->ldb, res,
+						     LDB_EXTENDED_SEQUENCE_NUMBER,
+						     tseq,
+						     NULL,
+						     res,
+						     ldb_extended_default_callback,
+						     NULL);
+			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
+				return ret;
+			}
+
+			ret = partition_request(data->partitions[i]->module, treq);
 			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
 				return ret;
 			}
-			timestamp = MAX(timestamp, date_req->op.seq_num.seq_num);
+			ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
+			if (ret != LDB_SUCCESS) {
+				talloc_free(res);
+				return ret;
+			}
+
+			tseqr = talloc_get_type(res->extended->data,
+						  struct ldb_seqnum_result);
+			timestamp = MAX(timestamp, tseqr->seq_num);
+
+			talloc_free(res);
 		}
+
 		break;
 	}
+
+	ext = talloc_zero(req, struct ldb_extended);
+	if (!ext) {
+		return LDB_ERR_OPERATIONS_ERROR;
 	}
+	seqr = talloc_zero(ext, struct ldb_seqnum_result);
+	if (seqr == NULL) {
+		talloc_free(ext);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ext->oid = LDB_EXTENDED_SEQUENCE_NUMBER;
+	ext->data = seqr;
 
-	switch (req->op.seq_num.flags) {
+	switch (seq->type) {
 	case LDB_SEQ_NEXT:
 	case LDB_SEQ_HIGHEST_SEQ:
 
-		req->op.seq_num.flags = 0;
-
 		/* Has someone above set a timebase sequence? */
 		if (timestamp_sequence) {
-			req->op.seq_num.seq_num = (((unsigned long long)timestamp << 24) | (seq_number & 0xFFFFFF));
+			seqr->seq_num = (((unsigned long long)timestamp << 24) | (seq_number & 0xFFFFFF));
 		} else {
-			req->op.seq_num.seq_num = seq_number;
+			seqr->seq_num = seq_number;
 		}
 
-		if (timestamp_sequence > req->op.seq_num.seq_num) {
-			req->op.seq_num.seq_num = timestamp_sequence;
-			req->op.seq_num.flags |= LDB_SEQ_TIMESTAMP_SEQUENCE;
+		if (timestamp_sequence > seqr->seq_num) {
+			seqr->seq_num = timestamp_sequence;
+			seqr->flags |= LDB_SEQ_TIMESTAMP_SEQUENCE;
 		}
 
-		req->op.seq_num.flags |= LDB_SEQ_GLOBAL_SEQUENCE;
+		seqr->flags |= LDB_SEQ_GLOBAL_SEQUENCE;
 		break;
 	case LDB_SEQ_HIGHEST_TIMESTAMP:
-		req->op.seq_num.seq_num = timestamp;
+		seqr->seq_num = timestamp;
 		break;
 	}
 
-	switch (req->op.seq_num.flags) {
-	case LDB_SEQ_NEXT:
-		req->op.seq_num.seq_num++;
+	if (seq->type == LDB_SEQ_NEXT) {
+		seqr->seq_num++;
 	}
-	return LDB_SUCCESS;
+
+	/* send request done */
+	return ldb_module_done(req, NULL, ext, LDB_SUCCESS);
 }
 
 static int partition_extended_replicated_objects(struct ldb_module *module, struct ldb_request *req)
@@ -906,6 +1029,10 @@ static int partition_extended(struct ldb_module *module, struct ldb_request *req
 		return ldb_next_request(module, req);
 	}
 
+	if (strcmp(req->op.extended.oid, LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
+		return partition_sequence_number(module, req);
+	}
+
 	if (strcmp(req->op.extended.oid, DSDB_EXTENDED_REPLICATED_OBJECTS_OID) == 0) {
 		return partition_extended_replicated_objects(module, req);
 	}
@@ -1204,7 +1331,6 @@ _PUBLIC_ const struct ldb_module_ops ldb_partition_module_ops = {
 	.del               = partition_delete,
 	.rename            = partition_rename,
 	.extended          = partition_extended,
-	.sequence_number   = partition_sequence_number,
 	.start_transaction = partition_start_trans,
 	.end_transaction   = partition_end_trans,
 	.del_transaction   = partition_del_trans,
diff --git a/source4/dsdb/samdb/ldb_modules/simple_ldap_map.c b/source4/dsdb/samdb/ldb_modules/simple_ldap_map.c
index d15e85ad41..c353914e2c 100644
--- a/source4/dsdb/samdb/ldb_modules/simple_ldap_map.c
+++ b/source4/dsdb/samdb/ldb_modules/simple_ldap_map.c
@@ -603,10 +603,18 @@ static int nsuniqueid_init(struct ldb_module *module)
 	return ldb_next_init(module);
 }
 
-static int get_seq(struct ldb_request *req,
-		   struct ldb_reply *ares)
+static int get_seq_callback(struct ldb_request *req,
+			    struct ldb_reply *ares)
 {
 	unsigned long long *seq = (unsigned long long *)req->context;
+
+	if (!ares) {
+		return ldb_request_done(req, LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_request_done(req, ares->error);
+	}
+
 	if (ares->type == LDB_REPLY_ENTRY) {
 		struct ldb_message_element *el = ldb_msg_find_element(ares->message, "contextCSN");
 		if (el) {
@@ -618,6 +626,7 @@ static int get_seq(struct ldb_request *req,
 		return ldb_request_done(req, LDB_SUCCESS);
 	}
 
+	talloc_free(ares);
 	return LDB_SUCCESS;
 }
 
@@ -626,7 +635,7 @@ static int entryuuid_sequence_number(struct ldb_module *module, struct ldb_reque
 	int ret;
 	struct map_private *map_private;
 	struct entryuuid_private *entryuuid_private;
-	unsigned long long seq = 0;
+	unsigned long long seq_num = 0;
 	struct ldb_request *search_req;
 
 	const struct ldb_control *partition_ctrl;
@@ -636,6 +645,12 @@ static int entryuuid_sequence_number(struct ldb_module *module, struct ldb_reque
 		"contextCSN", NULL
 	};
 
+	struct ldb_seqnum_request *seq;
+	struct ldb_seqnum_result *seqr;
+	struct ldb_extended *ext;
+
+	seq = talloc_get_type(req->op.extended.data, struct ldb_seqnum_request);
+
 	map_private = talloc_get_type(module->private_data, struct map_private);
 
 	entryuuid_private = talloc_get_type(map_private->caller_private, struct entryuuid_private);
@@ -655,7 +670,7 @@ static int entryuuid_sequence_number(struct ldb_module *module, struct ldb_reque
 	ret = ldb_build_search_req(&search_req, module->ldb, req,
 				   partition->dn, LDB_SCOPE_BASE,
 				   NULL, contextCSN_attr, NULL,
-				   &seq, get_seq,
+				   &seq_num, get_seq_callback,
 				   NULL);
 	if (ret != LDB_SUCCESS) {
 		return ret;
@@ -672,36 +687,59 @@ static int entryuuid_sequence_number(struct ldb_module *module, struct ldb_reque
 		return ret;
 	}
 
-	switch (req->op.seq_num.type) {
+	ext = talloc_zero(req, struct ldb_extended);
+	if (!ext) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	seqr = talloc_zero(req, struct ldb_seqnum_result);
+	if (seqr == NULL) {
+		talloc_free(ext);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ext->oid = LDB_EXTENDED_SEQUENCE_NUMBER;
+	ext->data = seqr;
+
+	switch (seq->type) {
 	case LDB_SEQ_HIGHEST_SEQ:
-		req->op.seq_num.seq_num = seq;
+		seqr->seq_num = seq_num;
 		break;
 	case LDB_SEQ_NEXT:
-		req->op.seq_num.seq_num = seq;
-		req->op.seq_num.seq_num++;
+		seqr->seq_num = seq_num;
+		seqr->seq_num++;
 		break;
 	case LDB_SEQ_HIGHEST_TIMESTAMP:
 	{
-		req->op.seq_num.seq_num = (seq >> 24);
+		seqr->seq_num = (seq_num >> 24);
 		break;
 	}
 	}
-	req->op.seq_num.flags = 0;
-	req->op.seq_num.flags |= LDB_SEQ_TIMESTAMP_SEQUENCE;
-	req->op.seq_num.flags |= LDB_SEQ_GLOBAL_SEQUENCE;
-	return LDB_SUCCESS;
+	seqr->flags = 0;
+	seqr->flags |= LDB_SEQ_TIMESTAMP_SEQUENCE;
+	seqr->flags |= LDB_SEQ_GLOBAL_SEQUENCE;
+
+	/* send request done */
+	return ldb_module_done(req, NULL, ext, LDB_SUCCESS);
+}
+
+static int entryuuid_extended(struct ldb_module *module, struct ldb_request *req)
+{
+	if (strcmp(req->op.extended.oid, LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
+		return entryuuid_sequence_number(module, req);
+	}
+
+	return ldb_next_request(module, req);
 }
 
 _PUBLIC_ const struct ldb_module_ops ldb_entryuuid_module_ops = {
 	.name		   = "entryuuid",
 	.init_context	   = entryuuid_init,
-	.sequence_number   = entryuuid_sequence_number,
+	.extended          = entryuuid_extended,
 	LDB_MAP_OPS
 };
 
 _PUBLIC_ const struct ldb_module_ops ldb_nsuniqueid_module_ops = {
 	.name		   = "nsuniqueid",
 	.init_context	   = nsuniqueid_init,
-	.sequence_number   = entryuuid_sequence_number,
+	.extended          = entryuuid_extended,
 	LDB_MAP_OPS
 };
diff --git a/source4/lib/ldb/common/ldb.c b/source4/lib/ldb/common/ldb.c
index 75c8109042..c013565da0 100644
--- a/source4/lib/ldb/common/ldb.c
+++ b/source4/lib/ldb/common/ldb.c
@@ -527,10 +527,6 @@ int ldb_request(struct ldb_context *ldb, struct ldb_request *req)
 		FIRST_OP(ldb, extended);
 		ret = module->ops->extended(module, req);
 		break;
-	case LDB_SEQUENCE_NUMBER:
-		FIRST_OP(ldb, sequence_number);
-		ret = module->ops->sequence_number(module, req);
-		break;
 	default:
 		FIRST_OP(ldb, request);
 		ret = module->ops->request(module, req);
@@ -1172,35 +1168,47 @@ int ldb_rename(struct ldb_context *ldb,
 int ldb_sequence_number(struct ldb_context *ldb,
 			enum ldb_sequence_type type, uint64_t *seq_num)
 {
-	struct ldb_request *req;
+	struct ldb_seqnum_request *seq;
+	struct ldb_seqnum_result *seqr;
+	struct ldb_result *res;
+	TALLOC_CTX *tmp_ctx;
 	int ret;
 
-	req = talloc_zero(ldb, struct ldb_request);
-	if (req == NULL) {
+	*seq_num = 0;
+
+	tmp_ctx = talloc_zero(ldb, struct ldb_request);
+	if (tmp_ctx == NULL) {
 		ldb_set_errstring(ldb, "Out of Memory");
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
+	seq = talloc_zero(tmp_ctx, struct ldb_seqnum_request);
+	if (seq == NULL) {
+		ldb_set_errstring(ldb, "Out of Memory");
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
+	}
+	seq->type = type;
 
-	req->operation = LDB_SEQUENCE_NUMBER;
-	req->controls = NULL;
-	req->context = NULL;
-	req->callback = ldb_op_default_callback;
-	ldb_set_timeout(ldb, req, 0); /* use default timeout */
-
-	req->op.seq_num.type = type;
-	/* do request and autostart a transaction */
-	ret = ldb_request(ldb, req);
+	ret = ldb_extended(ldb, LDB_EXTENDED_SEQUENCE_NUMBER, seq, &res);
+	if (ret != LDB_SUCCESS) {
+		goto done;
+	}
+	talloc_steal(tmp_ctx, res);
 
-	if (ret == LDB_SUCCESS) {
-		*seq_num = req->op.seq_num.seq_num;
+	if (strcmp(LDB_EXTENDED_SEQUENCE_NUMBER, res->extended->oid) != 0) {
+		ldb_set_errstring(ldb, "Invalid OID in reply");
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
 	}
+	seqr = talloc_get_type(res->extended->data,
+				struct ldb_seqnum_result);
+	*seq_num = seqr->seq_num;
 
-	talloc_free(req);
+done:
+	talloc_free(tmp_ctx);
 	return ret;
 }
 
-
-
 /*
   return extended error information
 */
diff --git a/source4/lib/ldb/common/ldb_modules.c b/source4/lib/ldb/common/ldb_modules.c
index 5cc8de29b4..2b453bb0c3 100644
--- a/source4/lib/ldb/common/ldb_modules.c
+++ b/source4/lib/ldb/common/ldb_modules.c
@@ -517,10 +517,6 @@ int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
 		FIND_OP(module, extended);
 		ret = module->ops->extended(module, request);
 		break;
-	case LDB_SEQUENCE_NUMBER:
-		FIND_OP(module, sequence_number);
-		ret = module->ops->sequence_number(module, request);
-		break;
 	default:
 		FIND_OP(module, request);
 		ret = module->ops->request(module, request);
diff --git a/source4/lib/ldb/include/ldb.h b/source4/lib/ldb/include/ldb.h
index b1ce3ef70b..9bc5c183d8 100644
--- a/source4/lib/ldb/include/ldb.h
+++ b/source4/lib/ldb/include/ldb.h
@@ -652,7 +652,6 @@ enum ldb_request_type {
 	LDB_DELETE,
 	LDB_RENAME,
 	LDB_EXTENDED,
-	LDB_SEQUENCE_NUMBER,
 	LDB_REQ_REGISTER_CONTROL,
 	LDB_REQ_REGISTER_PARTITION
 };
@@ -679,21 +678,38 @@ struct ldb_extended {
 	void *data; /* NULL or a valid talloc pointer! talloc_get_type() will be used on it */
 };
 
+#define LDB_EXTENDED_SEQUENCE_NUMBER	"1.3.6.1.4.1.7165.4.4.3"
+
+enum ldb_sequence_type {
+	LDB_SEQ_HIGHEST_SEQ,
+	LDB_SEQ_HIGHEST_TIMESTAMP,
+	LDB_SEQ_NEXT
+};
+
+struct ldb_seqnum_request {
+	enum ldb_sequence_type type;
+};
+
+struct ldb_seqnum_result {
+	uint64_t seq_num;
+	uint32_t flags;
+};
+
 struct ldb_result {
 	unsigned int count;
 	struct ldb_message **msgs;
-	char **refs;
 	struct ldb_extended *extended;
 	struct ldb_control **controls;
+	char **refs;
 };
 
 struct ldb_reply {
+	int error;
 	enum ldb_reply_type type;
 	struct ldb_message *message;
 	struct ldb_extended *response;
-	char *referral;
 	struct ldb_control **controls;
-	int error;
+	char *referral;
 };
 
 struct ldb_request;
@@ -732,18 +748,6 @@ struct ldb_register_partition {
 	struct ldb_dn *dn;
 };
 
-enum ldb_sequence_type {
-	LDB_SEQ_HIGHEST_SEQ,
-	LDB_SEQ_HIGHEST_TIMESTAMP,
-	LDB_SEQ_NEXT
-};
-
-struct ldb_sequence_number {
-	enum ldb_sequence_type type;
-	uint64_t seq_num;
-	uint32_t flags;
-};
-
 typedef int (*ldb_request_callback_t)(struct ldb_request *, struct ldb_reply *);
 
 struct ldb_request {
@@ -757,7 +761,6 @@ struct ldb_request {
 		struct ldb_delete del;
 		struct ldb_rename rename;
 		struct ldb_extended extended;
-		struct ldb_sequence_number seq_num;
 		struct ldb_register_control reg_control;
 		struct ldb_register_partition reg_partition;
 	} op;
diff --git a/source4/lib/ldb/ldb.i b/source4/lib/ldb/ldb.i
index 024ba1959a..6013462225 100644
--- a/source4/lib/ldb/ldb.i
+++ b/source4/lib/ldb/ldb.i
@@ -1219,25 +1219,6 @@ int py_module_del_transaction(struct ldb_module *mod)
     return LDB_SUCCESS;
 }
 
-int py_module_sequence_number(struct ldb_module *mod, struct ldb_request *req)
-{
-    PyObject *py_ldb = mod->private_data;
-    PyObject *py_result;
-    int ret;
-
-    py_result = PyObject_CallMethod(py_ldb, "sequence_number", "ili", req->op.seq_num.type, req->op.seq_num.seq_num, req->op.seq_num.flags);
-
-    if (py_result == NULL) {
-        return LDB_ERR_OPERATIONS_ERROR;
-    }
-
-    ret = PyInt_AsLong(py_result);
-
-    Py_DECREF(py_result);
-
-    return ret;
-}
-
 static int py_module_destructor(void *_mod)
 {
     struct ldb_module *mod = _mod;
@@ -1292,7 +1273,6 @@ int py_module_init (struct ldb_module *mod)
     $1->start_transaction = py_module_start_transaction;
     $1->end_transaction = py_module_end_transaction;
     $1->del_transaction = py_module_del_transaction;
-    $1->sequence_number = py_module_sequence_number;
 }
 
 %feature("docstring") ldb_register_module "S.register_module(module) -> None\n"
diff --git a/source4/lib/ldb/ldb_tdb/ldb_search.c b/source4/lib/ldb/ldb_tdb/ldb_search.c
index a220b4a628..1c76411db2 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_search.c
+++ b/source4/lib/ldb/ldb_tdb/ldb_search.c
@@ -277,30 +277,6 @@ int ltdb_search_dn1(struct ldb_module *module, struct ldb_dn *dn, struct ldb_mes
 }
 
 /*
-  lock the database for read - use by ltdb_search
-*/
-static int ltdb_lock_read(struct ldb_module *module)
-{
-	struct ltdb_private *ltdb = (struct ltdb_private *)module->private_data;
-	if (ltdb->in_transaction == 0) {
-		return tdb_lockall_read(ltdb->tdb);
-	}
-	return 0;
-}
-
-/*
-  unlock the database after a ltdb_lock_read()
-*/
-static int ltdb_unlock_read(struct ldb_module *module)
-{
-	struct ltdb_private *ltdb = (struct ltdb_private *)module->private_data;
-	if (ltdb->in_transaction == 0) {
-		return tdb_unlockall_read(ltdb->tdb);
-	}
-	return 0;
-}
-
-/*
   add a set of attributes from a record to a set of results
   return 0 on success, -1 on failure
 */
diff --git a/source4/lib/ldb/ldb_tdb/ldb_tdb.c b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
index 0087f6c44d..2282f61d47 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_tdb.c
+++ b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
@@ -79,6 +79,30 @@ static int ltdb_err_map(enum TDB_ERROR tdb_code)
 	return LDB_ERR_OTHER;
 }
 
+/*
+  lock the database for read - use by ltdb_search and ltdb_sequence_number
+*/
+int ltdb_lock_read(struct ldb_module *module)
+{
+	struct ltdb_private *ltdb = (struct ltdb_private *)module->private_data;
+	if (ltdb->in_transaction == 0) {
+		return tdb_lockall_read(ltdb->tdb);
+	}
+	return 0;
+}
+
+/*
+  unlock the database after a ltdb_lock_read()
+*/
+int ltdb_unlock_read(struct ldb_module *module)
+{
+	struct ltdb_private *ltdb = (struct ltdb_private *)module->private_data;
+	if (ltdb->in_transaction == 0) {
+		return tdb_unlockall_read(ltdb->tdb);
+	}
+	return 0;
+}
+
 
 /*
   form a TDB_DATA for a record key
@@ -860,61 +884,88 @@ static int ltdb_del_trans(struct ldb_module *module)
 /*
   return sequenceNumber from @BASEINFO
 */
-static int ltdb_sequence_number(struct ldb_module *module,
-				struct ldb_request *req)
+static int ltdb_sequence_number(struct ltdb_context *ctx,
+				struct ldb_extended **ext)
 {
+	struct ldb_module *module = ctx->module;
+	struct ldb_request *req = ctx->req;
 	TALLOC_CTX *tmp_ctx;
+	struct ldb_seqnum_request *seq;
+	struct ldb_seqnum_result *res;
 	struct ldb_message *msg = NULL;
 	struct ldb_dn *dn;
 	const char *date;
-	int tret;
+	int ret;
 
+	seq = talloc_get_type(req->op.extended.data,
+				struct ldb_seqnum_request);
+	if (seq == NULL) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	req->handle->state = LDB_ASYNC_PENDING;
+
+	if (ltdb_lock_read(module) != 0) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	res = talloc_zero(req, struct ldb_seqnum_result);
+	if (res == NULL) {
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
+	}
 	tmp_ctx = talloc_new(req);
 	if (tmp_ctx == NULL) {
-		talloc_free(tmp_ctx);
-		return LDB_ERR_OPERATIONS_ERROR;
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
 	}
 
 	dn = ldb_dn_new(tmp_ctx, module->ldb, LTDB_BASEINFO);
 
 	msg = talloc(tmp_ctx, struct ldb_message);
 	if (msg == NULL) {
-		talloc_free(tmp_ctx);
-		return LDB_ERR_OPERATIONS_ERROR;
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
 	}
 
-	req->op.seq_num.flags = 0;
-
-	tret = ltdb_search_dn1(module, dn, msg);
-	if (tret != LDB_SUCCESS) {
-		talloc_free(tmp_ctx);
-		/* zero is as good as anything when we don't know */
-		req->op.seq_num.seq_num = 0;
-		return tret;
+	ret = ltdb_search_dn1(module, dn, msg);
+	if (ret != LDB_SUCCESS) {
+		goto done;
 	}
 
-	switch (req->op.seq_num.type) {
+	switch (seq->type) {
 	case LDB_SEQ_HIGHEST_SEQ:
-		req->op.seq_num.seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
+		res->seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
 		break;
 	case LDB_SEQ_NEXT:
-		req->op.seq_num.seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
-		req->op.seq_num.seq_num++;
+		res->seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
+		res->seq_num++;
 		break;
 	case LDB_SEQ_HIGHEST_TIMESTAMP:
 		date = ldb_msg_find_attr_as_string(msg, LTDB_MOD_TIMESTAMP, NULL);
 		if (date) {
-			req->op.seq_num.seq_num = ldb_string_to_time(date);
+			res->seq_num = ldb_string_to_time(date);
 		} else {
-			req->op.seq_num.seq_num = 0;
+			res->seq_num = 0;
 			/* zero is as good as anything when we don't know */
 		}
 		break;
 	}
 
-	talloc_free(tmp_ctx);
+	*ext = talloc_zero(req, struct ldb_extended);
+	if (*ext == NULL) {
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
+	}
+	(*ext)->oid = LDB_EXTENDED_SEQUENCE_NUMBER;
+	(*ext)->data = talloc_steal(*ext, res);
 
-	return LDB_SUCCESS;
+	ret = LDB_SUCCESS;
+
+done:
+	talloc_free(tmp_ctx);
+	ltdb_unlock_read(module);
+	return ret;
 }
 
 void ltdb_request_done(struct ldb_request *req, int error)
@@ -949,6 +1000,47 @@ static void ltdb_timeout(struct event_context *ev,
 	ltdb_request_done(ctx->req, LDB_ERR_TIME_LIMIT_EXCEEDED);
 }
 
+static void ltdb_request_extended_done(struct ldb_request *req,
+					struct ldb_extended *ext,
+					int error)
+{
+	struct ldb_reply *ares;
+
+	/* if we already returned an error just return */
+	if (req->handle->status != LDB_SUCCESS) {
+		return;
+	}
+
+	ares = talloc_zero(req, struct ldb_reply);
+	if (!ares) {
+		ldb_oom(req->handle->ldb);
+		req->callback(req, NULL);
+		return;
+	}
+	ares->type = LDB_REPLY_DONE;
+	ares->response = ext;
+	ares->error = error;
+
+	req->callback(req, ares);
+}
+
+static void ltdb_handle_extended(struct ltdb_context *ctx)
+{
+	struct ldb_extended *ext = NULL;
+	int ret;
+
+	if (strcmp(ctx->req->op.extended.oid,
+		   LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
+		/* get sequence number */
+		ret = ltdb_sequence_number(ctx, &ext);
+	} else {
+		/* not recognized */
+		ret = LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
+	}
+
+	ltdb_request_extended_done(ctx->req, ext, ret);
+}
+
 static void ltdb_callback(struct event_context *ev,
 			  struct timed_event *te,
 			  struct timeval t,
@@ -975,6 +1067,9 @@ static void ltdb_callback(struct event_context *ev,
 	case LDB_RENAME:
 		ret = ltdb_rename(ctx);
 		break;
+	case LDB_EXTENDED:
+		ltdb_handle_extended(ctx);
+		return;
 	default:
 		/* no other op supported */
 		ret = LDB_ERR_UNWILLING_TO_PERFORM;
@@ -1037,11 +1132,10 @@ static const struct ldb_module_ops ltdb_ops = {
 	.modify            = ltdb_handle_request,
 	.del               = ltdb_handle_request,
 	.rename            = ltdb_handle_request,
-/*	.request           = ltdb_handle_request, */
+	.extended          = ltdb_handle_request,
 	.start_transaction = ltdb_start_trans,
 	.end_transaction   = ltdb_end_trans,
 	.del_transaction   = ltdb_del_trans,
-	.sequence_number   = ltdb_sequence_number
 };
 
 /*
diff --git a/source4/lib/ldb/ldb_tdb/ldb_tdb.h b/source4/lib/ldb/ldb_tdb/ldb_tdb.h
index 223181ca0b..61e90bccc6 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_tdb.h
+++ b/source4/lib/ldb/ldb_tdb/ldb_tdb.h
@@ -112,6 +112,8 @@ int ltdb_filter_attrs(struct ldb_message *msg, const char * const *attrs);
 int ltdb_search(struct ltdb_context *ctx);
 
 /* The following definitions come from lib/ldb/ldb_tdb/ldb_tdb.c  */
+int ltdb_lock_read(struct ldb_module *module);
+int ltdb_unlock_read(struct ldb_module *module);
 struct TDB_DATA ltdb_key(struct ldb_module *module, struct ldb_dn *dn);
 int ltdb_store(struct ldb_module *module, const struct ldb_message *msg, int flgs);
 int ltdb_delete_noindex(struct ldb_module *module, struct ldb_dn *dn);
diff --git a/source4/lib/ldb/ldb_wrap.c b/source4/lib/ldb/ldb_wrap.c
index cc8099f27f..bc9266a306 100644
--- a/source4/lib/ldb/ldb_wrap.c
+++ b/source4/lib/ldb/ldb_wrap.c
@@ -3505,25 +3505,6 @@ int py_module_del_transaction(struct ldb_module *mod)
     return LDB_SUCCESS;
 }
 
-int py_module_sequence_number(struct ldb_module *mod, struct ldb_request *req)
-{
-    PyObject *py_ldb = mod->private_data;
-    PyObject *py_result;
-    int ret;
-
-    py_result = PyObject_CallMethod(py_ldb, "sequence_number", "ili", req->op.seq_num.type, req->op.seq_num.seq_num, req->op.seq_num.flags);
-
-    if (py_result == NULL) {
-        return LDB_ERR_OPERATIONS_ERROR;
-    }
-
-    ret = PyInt_AsLong(py_result);
-
-    Py_DECREF(py_result);
-
-    return ret;
-}
-
 static int py_module_destructor(void *_mod)
 {
     struct ldb_module *mod = _mod;
@@ -6648,7 +6629,6 @@ SWIGINTERN PyObject *_wrap_register_module(PyObject *SWIGUNUSEDPARM(self), PyObj
   arg1->start_transaction = py_module_start_transaction;
   arg1->end_transaction = py_module_end_transaction;
   arg1->del_transaction = py_module_del_transaction;
-  arg1->sequence_number = py_module_sequence_number;
   result = ldb_register_module((struct ldb_module_ops const *)arg1);
   if (result != 0) {
     PyErr_SetObject(PyExc_LdbError, Py_BuildValue((char *)"(i,s)", result, ldb_strerror(result)));
diff --git a/source4/setup/schema_samba4.ldif b/source4/setup/schema_samba4.ldif
index 2c007395fb..c27157d713 100644
--- a/source4/setup/schema_samba4.ldif
+++ b/source4/setup/schema_samba4.ldif
@@ -177,6 +177,8 @@ oMSyntax: 20
 #Allocated: DSDB_CONTROL_REPLICATED_UPDATE_OID 1.3.6.1.4.1.7165.4.3.3
 
 #Allocated: DSDB_EXTENDED_REPLICATED_OBJECTS_OID 1.3.6.1.4.1.7165.4.4.1
+#Allocated: DSDB_EXTENDED_SCHEMA_UPDATE_NOW_OID 1.3.6.1.4.1.7165.4.4.2
+#Allocated: LDB_EXTENDED_SEQUENCE_NUMBER 1.3.6.1.4.1.7165.4.4.3
 
 #Allocated: (middleName) attributeID: 1.3.6.1.4.1.7165.4.255.1