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, 10 insertions, 6 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 3a12ee132b59..fad4c385f7a1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2212,7 +2212,7 @@ __be16 skb_network_protocol(struct sk_buff *skb)
         __be16 type = skb->protocol;
         int vlan_depth = ETH_HLEN;
 
-        while (type == htons(ETH_P_8021Q)) {
+        while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
                 struct vlan_hdr *vh;
 
                 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
@@ -2428,20 +2428,22 @@ netdev_features_t netif_skb_features(struct sk_buff *skb)
         if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
                 features &= ~NETIF_F_GSO_MASK;
 
-        if (protocol == htons(ETH_P_8021Q)) {
+        if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
                 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
                 protocol = veh->h_vlan_encapsulated_proto;
         } else if (!vlan_tx_tag_present(skb)) {
                 return harmonize_features(skb, protocol, features);
         }
 
-        features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX);
+        features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
+                                               NETIF_F_HW_VLAN_STAG_TX);
 
-        if (protocol != htons(ETH_P_8021Q)) {
+        if (protocol != htons(ETH_P_8021Q) && protocol != htons(ETH_P_8021AD)) {
                 return harmonize_features(skb, protocol, features);
         } else {
                 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
-                                NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX;
+                                NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
+                                NETIF_F_HW_VLAN_STAG_TX;
                 return harmonize_features(skb, protocol, features);
         }
 }
@@ -3360,6 +3362,7 @@ static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
         case __constant_htons(ETH_P_IP):
         case __constant_htons(ETH_P_IPV6):
         case __constant_htons(ETH_P_8021Q):
+        case __constant_htons(ETH_P_8021AD):
                 return true;
         default:
                 return false;
@@ -3400,7 +3403,8 @@ another_round:
 
         __this_cpu_inc(softnet_data.processed);
 
-        if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
+        if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
+            skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
                 skb = vlan_untag(skb);
                 if (unlikely(!skb))
                         goto unlock;