net: bridge: check vlan with eth_type_vlan() method

Replace some checks for ETH_P_8021Q and ETH_P_8021AD with
eth_type_vlan().
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20210117080950.122761-1-dong.menglong@zte.com.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/br_forward.c

@@ -39,8 +39,7 @@ int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb
 	br_drop_fake_rtable(skb);
 
 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
-	    (skb->protocol == htons(ETH_P_8021Q) ||
-	     skb->protocol == htons(ETH_P_8021AD))) {
+	    eth_type_vlan(skb->protocol)) {
 		int depth;
 
 		if (!__vlan_get_protocol(skb, skb->protocol, &depth))

net/bridge/br_netlink.c

@@ -1096,15 +1096,9 @@ static int br_validate(struct nlattr *tb[], struct nlattr *data[],
 		return 0;
 
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-	if (data[IFLA_BR_VLAN_PROTOCOL]) {
-		switch (nla_get_be16(data[IFLA_BR_VLAN_PROTOCOL])) {
-		case htons(ETH_P_8021Q):
-		case htons(ETH_P_8021AD):
-			break;
-		default:
-			return -EPROTONOSUPPORT;
-		}
-	}
+	if (data[IFLA_BR_VLAN_PROTOCOL] &&
+	    !eth_type_vlan(nla_get_be16(data[IFLA_BR_VLAN_PROTOCOL])))
+		return -EPROTONOSUPPORT;
 
 	if (data[IFLA_BR_VLAN_DEFAULT_PVID]) {
 		__u16 defpvid = nla_get_u16(data[IFLA_BR_VLAN_DEFAULT_PVID]);

net/bridge/br_vlan.c

@@ -917,7 +917,7 @@ int __br_vlan_set_proto(struct net_bridge *br, __be16 proto)
 
 int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
 {
-	if (val != ETH_P_8021Q && val != ETH_P_8021AD)
+	if (!eth_type_vlan(htons(val)))
 		return -EPROTONOSUPPORT;
 
 	return __br_vlan_set_proto(br, htons(val));