vlan: Introduce helper functions to check if skb is tagged

Separate the two checks for single vlan and multiple vlans in
netif_skb_features().  This allows us to move the check for multiple
vlans to another function later.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index b11b28a..4265d44 100644 (file)
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -561,4 +561,49 @@ static inline void vlan_set_encap_proto(struct sk_buff *skb,
                skb->protocol = htons(ETH_P_802_2);
 }
 
+/**
+ * skb_vlan_tagged - check if skb is vlan tagged.
+ * @skb: skbuff to query
+ *
+ * Returns true if the skb is tagged, regardless of whether it is hardware
+ * accelerated or not.
+ */
+static inline bool skb_vlan_tagged(const struct sk_buff *skb)
+{
+       if (!skb_vlan_tag_present(skb) &&
+           likely(skb->protocol != htons(ETH_P_8021Q) &&
+                  skb->protocol != htons(ETH_P_8021AD)))
+               return false;
+
+       return true;
+}
+
+/**
+ * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
+ * @skb: skbuff to query
+ *
+ * Returns true if the skb is tagged with multiple vlan headers, regardless
+ * of whether it is hardware accelerated or not.
+ */
+static inline bool skb_vlan_tagged_multi(const struct sk_buff *skb)
+{
+       __be16 protocol = skb->protocol;
+
+       if (!skb_vlan_tag_present(skb)) {
+               struct vlan_ethhdr *veh;
+
+               if (likely(protocol != htons(ETH_P_8021Q) &&
+                          protocol != htons(ETH_P_8021AD)))
+                       return false;
+
+               veh = (struct vlan_ethhdr *)skb->data;
+               protocol = veh->h_vlan_encapsulated_proto;
+       }
+
+       if (protocol != htons(ETH_P_8021Q) && protocol != htons(ETH_P_8021AD))
+               return false;
+
+       return true;
+}
+
 #endif /* !(_LINUX_IF_VLAN_H_) */

diff --cc net/core/dev.c
Simple merge