net: vlan: add 802.1ad support

Add support for 802.1ad VLAN devices. This mainly consists of checking for
ETH_P_8021AD in addition to ETH_P_8021Q in a couple of places and check
offloading capabilities based on the used protocol.

Configuration is done using "ip link":

# ip link add link eth0 eth0.1000 \
	type vlan proto 802.1ad id 1000
# ip link add link eth0.1000 eth0.1000.1000 \
	type vlan proto 802.1q id 1000

52:54:00:12:34:56 > 92:b1:54:28:e4:8c, ethertype 802.1Q (0x8100), length 106: vlan 1000, p 0, ethertype 802.1Q, vlan 1000, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    20.1.0.2 > 20.1.0.1: ICMP echo request, id 3003, seq 8, length 64
92:b1:54:28:e4:8c > 52:54:00:12:34:56, ethertype 802.1Q-QinQ (0x88a8), length 106: vlan 1000, p 0, ethertype 802.1Q, vlan 1000, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 47944, offset 0, flags [none], proto ICMP (1), length 84)
    20.1.0.1 > 20.1.0.2: ICMP echo reply, id 3003, seq 8, length 64

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 245de9653db0..abc9cb631c47 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -91,6 +91,7 @@ static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
 
 enum vlan_protos {
         VLAN_PROTO_8021Q        = 0,
+        VLAN_PROTO_8021AD,
         VLAN_PROTO_NUM,
 };
 
@@ -116,6 +117,8 @@ static inline unsigned int vlan_proto_idx(__be16 proto)
         switch (proto) {
         case __constant_htons(ETH_P_8021Q):
                 return VLAN_PROTO_8021Q;
+        case __constant_htons(ETH_P_8021AD):
+                return VLAN_PROTO_8021AD;
         default:
                 BUG();
         }