ebtables: Allow filtering of hardware accelerated vlan frames.

An upcoming commit will allow packets with hardware vlan acceleration
information to be passed though more parts of the network stack, including
packets trunked through the bridge.  This adds support for matching and
filtering those packets through ebtables.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 7f9ce96..47c2dab 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -64,22 +64,24 @@
 
 static inline __be16 vlan_proto(const struct sk_buff *skb)
 {
-	return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+	if (vlan_tx_tag_present(skb))
+		return skb->protocol;
+	else if (skb->protocol == htons(ETH_P_8021Q))
+		return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+	else
+		return 0;
 }
 
 #define IS_VLAN_IP(skb) \
-	(skb->protocol == htons(ETH_P_8021Q) && \
-	 vlan_proto(skb) == htons(ETH_P_IP) && 	\
+	(vlan_proto(skb) == htons(ETH_P_IP) && \
 	 brnf_filter_vlan_tagged)
 
 #define IS_VLAN_IPV6(skb) \
-	(skb->protocol == htons(ETH_P_8021Q) && \
-	 vlan_proto(skb) == htons(ETH_P_IPV6) &&\
+	(vlan_proto(skb) == htons(ETH_P_IPV6) && \
 	 brnf_filter_vlan_tagged)
 
 #define IS_VLAN_ARP(skb) \
-	(skb->protocol == htons(ETH_P_8021Q) &&	\
-	 vlan_proto(skb) == htons(ETH_P_ARP) &&	\
+	(vlan_proto(skb) == htons(ETH_P_ARP) &&	\
 	 brnf_filter_vlan_tagged)
 
 static inline __be16 pppoe_proto(const struct sk_buff *skb)