s4 dsdb: Use the changereplmetadata control

This control allow to specify the replPropertyMetaData attribute to
be specified on modify request. It can be used for very specific needs
to tweak the content of the replication data.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>

1 files changed, 144 insertions, 61 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
index 90af17f7ec..2205be07c1 100644
--- a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
+++ b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
@@ -5,6 +5,7 @@
    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
    Copyright (C) Andrew Tridgell 2005
    Copyright (C) Stefan Metzmacher <metze@samba.org> 2007
+   Copyright (C) Matthieu Patou <mat@samba.org> 2010
 
    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
@@ -1073,6 +1074,20 @@ static int replmd_update_rpmd_element(struct ldb_context *ldb,
 	return LDB_SUCCESS;
 }
 
+static uint64_t find_max_local_usn(struct replPropertyMetaDataBlob omd)
+{
+	uint32_t count = omd.ctr.ctr1.count;
+	uint64_t max = 0;
+	uint32_t i;
+	for (i=0; i < count; i++) {
+		struct replPropertyMetaData1 m = omd.ctr.ctr1.array[i];
+		if (max < m.local_usn) {
+			max = m.local_usn;
+		}
+	}
+	return max;
+}
+
 /*
  * update the replPropertyMetaData object each time we modify an
  * object. This is needed for DRS replication, as the merge on the
@@ -1093,11 +1108,12 @@ static int replmd_update_rpmd(struct ldb_module *module,
 	const struct GUID *our_invocation_id;
 	int ret;
 	const char *attrs[] = { "replPropertyMetaData", "*", NULL };
+	const char *attrs2[] = { "uSNChanged", "objectClass", NULL };
 	struct ldb_result *res;
 	struct ldb_context *ldb;
 	struct ldb_message_element *objectclass_el;
 	enum urgent_situation situation;
-	bool rodc;
+	bool rodc, rmd_is_provided;
 
 	ldb = ldb_module_get_ctx(module);
 
@@ -1111,21 +1127,10 @@ static int replmd_update_rpmd(struct ldb_module *module,
 
 	unix_to_nt_time(&now, t);
 
-	/* search for the existing replPropertyMetaDataBlob. We need
-	 * to use REVEAL and ask for DNs in storage format to support
-	 * the check for values being the same in
-	 * replmd_update_rpmd_element()
-	 */
-	ret = dsdb_module_search_dn(module, msg, &res, msg->dn, attrs,
-	                            DSDB_FLAG_NEXT_MODULE |
-	                            DSDB_SEARCH_SHOW_DELETED |
-				    DSDB_SEARCH_SHOW_EXTENDED_DN |
-				    DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT |
-				    DSDB_SEARCH_REVEAL_INTERNALS);
-	if (ret != LDB_SUCCESS || res->count != 1) {
-		DEBUG(0,(__location__ ": Object %s failed to find replPropertyMetaData\n",
-			 ldb_dn_get_linearized(msg->dn)));
-		return LDB_ERR_OPERATIONS_ERROR;
+	if (ldb_request_get_control(req, DSDB_CONTROL_CHANGEREPLMETADATA_OID)) {
+		rmd_is_provided = true;
+	} else {
+		rmd_is_provided = false;
 	}
 
 	/* if isDeleted is present and is TRUE, then we consider we are deleting,
@@ -1136,62 +1141,140 @@ static int replmd_update_rpmd(struct ldb_module *module,
 		situation = REPL_URGENT_ON_UPDATE;
 	}
 
-	objectclass_el = ldb_msg_find_element(res->msgs[0], "objectClass");
-	if (is_urgent && replmd_check_urgent_objectclass(objectclass_el,
-							situation)) {
-		*is_urgent = true;
-	}
+	if (rmd_is_provided) {
+		/* In this case the change_replmetadata control was supplied */
+		/* We check that it's the only attribute that is provided
+		 * (it's a rare case so it's better to keep the code simplier)
+		 * We also check that the highest local_usn is bigger than
+		 * uSNChanged. */
+		uint64_t db_seq;
+		if( msg->num_elements != 1 ||
+			strncmp(msg->elements[0].name,
+				"replPropertyMetaData", 20) ) {
+			DEBUG(0,(__location__ ": changereplmetada control called without "\
+				"a specified replPropertyMetaData attribute or with others\n"));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		if (situation == REPL_URGENT_ON_DELETE) {
+			DEBUG(0,(__location__ ": changereplmetada control can't be called when deleting an object\n"));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		omd_value = ldb_msg_find_ldb_val(msg, "replPropertyMetaData");
+		if (!omd_value) {
+			DEBUG(0,(__location__ ": replPropertyMetaData was not specified for Object %s\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		ndr_err = ndr_pull_struct_blob(omd_value, msg, &omd,
+					       (ndr_pull_flags_fn_t)ndr_pull_replPropertyMetaDataBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			DEBUG(0,(__location__ ": Failed to parse replPropertyMetaData for %s\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		*seq_num = find_max_local_usn(omd);
 
-	omd_value = ldb_msg_find_ldb_val(res->msgs[0], "replPropertyMetaData");
-	if (!omd_value) {
-		DEBUG(0,(__location__ ": Object %s does not have a replPropertyMetaData attribute\n",
-			 ldb_dn_get_linearized(msg->dn)));
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
+		ret = dsdb_module_search_dn(module, msg, &res, msg->dn, attrs2,
+					    DSDB_FLAG_NEXT_MODULE |
+					    DSDB_SEARCH_SHOW_DELETED |
+					    DSDB_SEARCH_SHOW_EXTENDED_DN |
+					    DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT |
+					    DSDB_SEARCH_REVEAL_INTERNALS);
 
-	ndr_err = ndr_pull_struct_blob(omd_value, msg, &omd,
-				       (ndr_pull_flags_fn_t)ndr_pull_replPropertyMetaDataBlob);
-	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
-		DEBUG(0,(__location__ ": Failed to parse replPropertyMetaData for %s\n",
-			 ldb_dn_get_linearized(msg->dn)));
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
+		if (ret != LDB_SUCCESS || res->count != 1) {
+			DEBUG(0,(__location__ ": Object %s failed to find uSNChanged\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
 
-	if (omd.version != 1) {
-		DEBUG(0,(__location__ ": bad version %u in replPropertyMetaData for %s\n",
-			 omd.version, ldb_dn_get_linearized(msg->dn)));
-		return LDB_ERR_OPERATIONS_ERROR;
-	}
+		objectclass_el = ldb_msg_find_element(res->msgs[0], "objectClass");
+		if (is_urgent && replmd_check_urgent_objectclass(objectclass_el,
+								situation)) {
+			*is_urgent = true;
+		}
 
-	/*we have elements that will be modified*/
-	if (msg->num_elements > 0) {
-		/*if we are RODC and this is a DRSR update then its ok*/
-		if (!ldb_request_get_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID)) {
-			ret = samdb_rodc(ldb, &rodc);
-			if (ret != LDB_SUCCESS) {
-				DEBUG(4, (__location__ ": unable to tell if we are an RODC\n"));
-			} else if (rodc) {
-				ldb_asprintf_errstring(ldb, "RODC modify is forbidden\n");
-				return LDB_ERR_REFERRAL;
-			}
+		db_seq = ldb_msg_find_attr_as_uint64(res->msgs[0], "uSNChanged", 0);
+		if (*seq_num <= db_seq) {
+			DEBUG(0,(__location__ ": changereplmetada control provided but max(local_usn)"\
+					      " is less or equal to uSNChanged (max = %lld uSNChanged = %lld)\n",
+					      *seq_num, db_seq));
+			return LDB_ERR_OPERATIONS_ERROR;
 		}
-	}
 
-	for (i=0; i<msg->num_elements; i++) {
-		struct ldb_message_element *old_el;
-		old_el = ldb_msg_find_element(res->msgs[0], msg->elements[i].name);
-		ret = replmd_update_rpmd_element(ldb, msg, &msg->elements[i], old_el, &omd, schema, seq_num,
-						 our_invocation_id, now);
-		if (ret != LDB_SUCCESS) {
-			return ret;
+	} else {
+		/* search for the existing replPropertyMetaDataBlob. We need
+		 * to use REVEAL and ask for DNs in storage format to support
+		 * the check for values being the same in
+		 * replmd_update_rpmd_element()
+		 */
+		ret = dsdb_module_search_dn(module, msg, &res, msg->dn, attrs,
+					    DSDB_FLAG_NEXT_MODULE |
+					    DSDB_SEARCH_SHOW_DELETED |
+					    DSDB_SEARCH_SHOW_EXTENDED_DN |
+					    DSDB_SEARCH_SHOW_DN_IN_STORAGE_FORMAT |
+					    DSDB_SEARCH_REVEAL_INTERNALS);
+		if (ret != LDB_SUCCESS || res->count != 1) {
+			DEBUG(0,(__location__ ": Object %s failed to find replPropertyMetaData\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
 		}
 
-		if (is_urgent && !*is_urgent && (situation == REPL_URGENT_ON_UPDATE)) {
-			*is_urgent = replmd_check_urgent_attribute(&msg->elements[i]);
+		objectclass_el = ldb_msg_find_element(res->msgs[0], "objectClass");
+		if (is_urgent && replmd_check_urgent_objectclass(objectclass_el,
+								situation)) {
+			*is_urgent = true;
 		}
 
-	}
+		omd_value = ldb_msg_find_ldb_val(res->msgs[0], "replPropertyMetaData");
+		if (!omd_value) {
+			DEBUG(0,(__location__ ": Object %s does not have a replPropertyMetaData attribute\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
 
+		ndr_err = ndr_pull_struct_blob(omd_value, msg, &omd,
+					       (ndr_pull_flags_fn_t)ndr_pull_replPropertyMetaDataBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			DEBUG(0,(__location__ ": Failed to parse replPropertyMetaData for %s\n",
+				 ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		if (omd.version != 1) {
+			DEBUG(0,(__location__ ": bad version %u in replPropertyMetaData for %s\n",
+				 omd.version, ldb_dn_get_linearized(msg->dn)));
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		/*we have elements that will be modified*/
+		if (msg->num_elements > 0) {
+			/*if we are RODC and this is a DRSR update then its ok*/
+			if (!ldb_request_get_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID)) {
+				ret = samdb_rodc(ldb, &rodc);
+				if (ret != LDB_SUCCESS) {
+					DEBUG(4, (__location__ ": unable to tell if we are an RODC\n"));
+				} else if (rodc) {
+					ldb_asprintf_errstring(ldb, "RODC modify is forbidden\n");
+					return LDB_ERR_REFERRAL;
+				}
+			}
+		}
+
+		for (i=0; i<msg->num_elements; i++) {
+			struct ldb_message_element *old_el;
+			old_el = ldb_msg_find_element(res->msgs[0], msg->elements[i].name);
+			ret = replmd_update_rpmd_element(ldb, msg, &msg->elements[i], old_el, &omd, schema, seq_num,
+							 our_invocation_id, now);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+
+			if (is_urgent && !*is_urgent && (situation == REPL_URGENT_ON_UPDATE)) {
+				*is_urgent = replmd_check_urgent_attribute(&msg->elements[i]);
+			}
+
+		}
+	}
 	/*
 	 * replmd_update_rpmd_element has done an update if the
 	 * seq_num is set