net: fib_rules: add extack support

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index c795c3f..7223669 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -121,13 +121,16 @@ static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 
 static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 				 struct fib_rule_hdr *frh,
-				 struct nlattr **tb)
+				 struct nlattr **tb,
+				 struct netlink_ext_ack *extack)
 {
 	int err = -EINVAL;
 	struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
 
-	if (frh->tos)
+	if (frh->tos) {
+		NL_SET_ERR_MSG(extack, "Invalid tos value");
 		goto  errout;
+	}
 
 	if (rule->table == RT_TABLE_UNSPEC) {
 		if (rule->action == FR_ACT_TO_TBL) {