net/sched: flower: Helper function for vlan ethtype checks

There are somewhat repetitive ethertype checks in fl_set_key. Refactor
them into is_vlan_key helper function.

To make the changes clearer, avoid touching identation levels. This is
the job for the next patch in the series.
Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_flower.c

@@ -1579,6 +1579,21 @@ static int fl_set_key_ct(struct nlattr **tb,
 	return 0;
 }
 
+static bool is_vlan_key(struct nlattr *tb, __be16 *ethertype,
+			struct fl_flow_key *key, struct fl_flow_key *mask)
+{
+	if (!tb)
+		return false;
+
+	*ethertype = nla_get_be16(tb);
+	if (eth_type_vlan(*ethertype))
+		return true;
+
+	key->basic.n_proto = *ethertype;
+	mask->basic.n_proto = cpu_to_be16(~0);
+	return false;
+}
+
 static int fl_set_key(struct net *net, struct nlattr **tb,
 		      struct fl_flow_key *key, struct fl_flow_key *mask,
 		      struct netlink_ext_ack *extack)
@@ -1601,18 +1616,13 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
 		       mask->eth.src, TCA_FLOWER_KEY_ETH_SRC_MASK,
 		       sizeof(key->eth.src));
 
-	if (tb[TCA_FLOWER_KEY_ETH_TYPE]) {
-		ethertype = nla_get_be16(tb[TCA_FLOWER_KEY_ETH_TYPE]);
-
-		if (eth_type_vlan(ethertype)) {
+	if (is_vlan_key(tb[TCA_FLOWER_KEY_ETH_TYPE], &ethertype, key, mask)) {
 			fl_set_key_vlan(tb, ethertype, TCA_FLOWER_KEY_VLAN_ID,
 					TCA_FLOWER_KEY_VLAN_PRIO,
 					TCA_FLOWER_KEY_VLAN_ETH_TYPE,
 					&key->vlan, &mask->vlan);
 
-			if (tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE]) {
-				ethertype = nla_get_be16(tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE]);
-				if (eth_type_vlan(ethertype)) {
+			if (is_vlan_key(tb[TCA_FLOWER_KEY_VLAN_ETH_TYPE], &ethertype, key, mask)) {
 					fl_set_key_vlan(tb, ethertype,
 							TCA_FLOWER_KEY_CVLAN_ID,
 							TCA_FLOWER_KEY_CVLAN_PRIO,
@@ -1623,15 +1633,7 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
 						       &mask->basic.n_proto,
 						       TCA_FLOWER_UNSPEC,
 						       sizeof(key->basic.n_proto));
-				} else {
-					key->basic.n_proto = ethertype;
-					mask->basic.n_proto = cpu_to_be16(~0);
-				}
 			}
-		} else {
-			key->basic.n_proto = ethertype;
-			mask->basic.n_proto = cpu_to_be16(~0);
-		}
 	}
 
 	if (key->basic.n_proto == htons(ETH_P_IP) ||