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>

3 files changed, 11 insertions, 2 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 8086ff9988b1..a78f9390da87 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -162,6 +162,8 @@ static inline bool vlan_hw_offload_capable(netdev_features_t features,
 {
         if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
                 return true;
+        if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
+                return true;
         return false;
 }
 
@@ -271,9 +273,9 @@ static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 {
         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 
-        if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
+        if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
+            veth->h_vlan_proto != htons(ETH_P_8021AD))
                 return -EINVAL;
-        }
 
         *vlan_tci = ntohs(veth->h_vlan_TCI);
         return 0;
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index 785913b8983d..cbaa027ef5a7 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -25,6 +25,9 @@ enum {
         NETIF_F_HW_VLAN_CTAG_TX_BIT,    /* Transmit VLAN CTAG HW acceleration */
         NETIF_F_HW_VLAN_CTAG_RX_BIT,    /* Receive VLAN CTAG HW acceleration */
         NETIF_F_HW_VLAN_CTAG_FILTER_BIT,/* Receive filtering on VLAN CTAGs */
+        NETIF_F_HW_VLAN_STAG_TX_BIT,    /* Transmit VLAN STAG HW acceleration */
+        NETIF_F_HW_VLAN_STAG_RX_BIT,    /* Receive VLAN STAG HW acceleration */
+        NETIF_F_HW_VLAN_STAG_FILTER_BIT,/* Receive filtering on VLAN STAGs */
         NETIF_F_VLAN_CHALLENGED_BIT,    /* Device cannot handle VLAN packets */
         NETIF_F_GSO_BIT,                /* Enable software GSO. */
         NETIF_F_LLTX_BIT,               /* LockLess TX - deprecated. Please */
@@ -83,6 +86,9 @@ enum {
 #define NETIF_F_HW_VLAN_CTAG_FILTER __NETIF_F(HW_VLAN_CTAG_FILTER)
 #define NETIF_F_HW_VLAN_CTAG_RX __NETIF_F(HW_VLAN_CTAG_RX)
 #define NETIF_F_HW_VLAN_CTAG_TX __NETIF_F(HW_VLAN_CTAG_TX)
+#define NETIF_F_HW_VLAN_STAG_FILTER __NETIF_F(HW_VLAN_STAG_FILTER)
+#define NETIF_F_HW_VLAN_STAG_RX __NETIF_F(HW_VLAN_STAG_RX)
+#define NETIF_F_HW_VLAN_STAG_TX __NETIF_F(HW_VLAN_STAG_TX)
 #define NETIF_F_IP_CSUM         __NETIF_F(IP_CSUM)
 #define NETIF_F_IPV6_CSUM       __NETIF_F(IPV6_CSUM)
 #define NETIF_F_LLTX            __NETIF_F(LLTX)
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 9922704f08af..e3163544f339 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -250,6 +250,7 @@ enum {
         IFLA_VLAN_FLAGS,
         IFLA_VLAN_EGRESS_QOS,
         IFLA_VLAN_INGRESS_QOS,
+        IFLA_VLAN_PROTOCOL,
         __IFLA_VLAN_MAX,
 };