s4-dsdb: added dsdb_check_single_valued_link()

This is used in conjunction with the RELAX control, to check for
violations of single value rules for linked attributes

2 files changed, 31 insertions, 0 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/util.c b/source4/dsdb/samdb/ldb_modules/util.c
index b0ccd0341c..fa451f4bcf 100644
--- a/source4/dsdb/samdb/ldb_modules/util.c
+++ b/source4/dsdb/samdb/ldb_modules/util.c
@@ -371,3 +371,32 @@ const struct dsdb_class * get_last_structural_class(const struct dsdb_schema *sc
 
 	return last_class;
 }
+
+/*
+  check if a single valued link has multiple non-deleted values
+
+  This is needed when we will be using the RELAX control to stop
+  ldb_tdb from checking single valued links
+ */
+int dsdb_check_single_valued_link(const struct dsdb_attribute *attr,
+				  const struct ldb_message_element *el)
+{
+	bool found_active = false;
+	int i;
+
+	if (!(attr->ldb_schema_attribute->flags & LDB_ATTR_FLAG_SINGLE_VALUE) ||
+	    el->num_values < 2) {
+		return LDB_SUCCESS;
+	}
+
+	for (i=0; i<el->num_values; i++) {
+		if (!dsdb_dn_is_deleted_val(&el->values[i])) {
+			if (found_active) {
+				return LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
+			}
+			found_active = true;
+		}
+	}
+
+	return LDB_SUCCESS;
+}
diff --git a/source4/dsdb/samdb/ldb_modules/util.h b/source4/dsdb/samdb/ldb_modules/util.h
index cc184eee8f..66579ab852 100644
--- a/source4/dsdb/samdb/ldb_modules/util.h
+++ b/source4/dsdb/samdb/ldb_modules/util.h
@@ -21,6 +21,8 @@
 
 struct dsdb_schema; /* predeclare schema struct */
 struct GUID;
+struct dsdb_attribute;
+
 #include "dsdb/samdb/ldb_modules/util_proto.h"
 
 #define DSDB_SEARCH_SEARCH_ALL_PARTITIONS     0x0001