netfilter: nft_payload: add C-VLAN offload support

Match on h_vlan_encapsulated_proto and set up protocol dependency. Check
for protocol dependency before accessing the tci field. Allow to match
on the encapsulated ethertype too.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index f17939f..1993af3 100644 (file)
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -203,6 +203,22 @@ static int nft_payload_offload_ll(struct nft_offload_ctx *ctx,
 
                NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan,
                                  vlan_tpid, sizeof(__be16), reg);
+               nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
+               break;
+       case offsetof(struct vlan_ethhdr, h_vlan_TCI) + sizeof(struct vlan_hdr):
+               if (priv->len != sizeof(__be16))
+                       return -EOPNOTSUPP;
+
+               NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, vlan,
+                                 vlan_tci, sizeof(__be16), reg);
+               break;
+       case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto) +
+                                                       sizeof(struct vlan_hdr):
+               if (priv->len != sizeof(__be16))
+                       return -EOPNOTSUPP;
+
+               NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, vlan,
+                                 vlan_tpid, sizeof(__be16), reg);
                break;
        default:
                return -EOPNOTSUPP;