netfilter: nftables_offload: special ethertype handling for VLAN
[ Upstream commit 783003f3bb8a565326e89d18bbd948ad8ffc816a ]
The nftables offload parser sets FLOW_DISSECTOR_KEY_BASIC .n_proto to the
ethertype field in the ethertype frame. However:
- FLOW_DISSECTOR_KEY_BASIC .n_proto field always stores either IPv4 or IPv6
ethertypes.
- FLOW_DISSECTOR_KEY_VLAN .vlan_tpid stores either the 802.1q and 802.1ad
ethertypes. Same as for FLOW_DISSECTOR_KEY_CVLAN.
This function adjusts the flow dissector to handle two scenarios:
1) FLOW_DISSECTOR_KEY_VLAN .vlan_tpid is set to 802.1q or 802.1ad.
Then, transfer:
- the .n_proto field to FLOW_DISSECTOR_KEY_VLAN .tpid.
- the original FLOW_DISSECTOR_KEY_VLAN .tpid to the
FLOW_DISSECTOR_KEY_CVLAN .tpid
- the original FLOW_DISSECTOR_KEY_CVLAN .tpid to the .n_proto field.
2) .n_proto is set to 802.1q or 802.1ad. Then, transfer:
- the .n_proto field to FLOW_DISSECTOR_KEY_VLAN .tpid.
- the original FLOW_DISSECTOR_KEY_VLAN .tpid to the .n_proto field.
Fixes: a82055af5959 ("netfilter: nft_payload: add VLAN offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed