[PATCH net-next V19 2/3] Check for vlan ethernet types for 8021.q or 802.1ad

[Thomas F Herbert <thomasfherbert@gmail.com>]

This is to simplify using double tagged vlans. This function allows all
valid vlan ethertypes to be checked in a single function call.

Signed-off-by: Thomas F Herbert <thomasfherbert@gmail.com>
---
 include/linux/if_vlan.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 67ce5bd..d2494b5 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -627,6 +627,22 @@ static inline netdev_features_t vlan_features_check(const struct sk_buff *skb,
 
 	return features;
 }
+/**
+ * eth_type_vlan - check for valid vlan ether type.
+ * @ethertype: ether type to check
+ *
+ * Returns true if the ether type is a vlan ether type.
+ */
+static inline bool eth_type_vlan(__be16 ethertype)
+{
+	switch (ethertype) {
+	case htons(ETH_P_8021Q):
+	case htons(ETH_P_8021AD):
+		return true;
+	default:
+		return false;
+	}
+}
 
 /**
  * compare_vlan_header - Compare two vlan headers
-- 
2.4.3