Subject: [PATCH net-next 0/3] net: add helper support in tc act_ct for ovs offloading

From: Xin Long <[email-masked]>
Date: Tue, 4 Oct 2022 21:19:53 -0400

Ilya reported an issue that FTP traffic would be broken when the OVS flow
with ct(commit,alg=ftp) installed in the OVS kernel module, and it was
caused by that TC didn't support the ftp helper offloaded from OVS.

This patchset is to add the helper support in act_ct for ovs offloading
in kernel net/sched.

The 1st patch moves some code from openvswitch into nf_conntrack_helper
so that it can be used by net/sched in the 3rd patch (Note there are
still some other common code used in both OVS and TC and I will extract
it in other patches). The 2nd patch extracts another function in net/
sched to make the 3rd patch easier to write.

The user space part will be added in another patch, and with it these OVS
flows (FTP over SNAT) can be used to test this feature:

  table=0, in_port=veth1,tcp,tcp_dst=2121,ct_state=-trk \
    actions=ct(table=1, nat), normal
  table=0, in_port=veth2,tcp,ct_state=-trk actions=ct(table=1, nat)
  table=0, in_port=veth1,tcp,ct_state=-trk actions=ct(table=0, nat)
  table=0, in_port=veth1,tcp,ct_state=+trk+rel actions=ct(commit, nat),normal
  table=0, in_port=veth1,tcp,ct_state=+trk+est actions=veth2"

  table=1, in_port=veth1,tcp,tcp_dst=2121,ct_state=+trk+new \
    actions=ct(commit, nat(src=7.7.16.1), alg=ftp),normal"
  table=1, in_port=veth1,tcp,tcp_dst=2121,ct_state=+trk+est actions=veth2"
  table=1, in_port=veth2,tcp,ct_state=+trk+est actions=veth1"

Xin Long (3):
  net: move the helper function to nf_conntrack_helper for ovs and tc
  net: sched: call tcf_ct_params_free to free params in tcf_ct_init
  net: sched: add helper support in act_ct

 include/net/netfilter/nf_conntrack_helper.h |   2 +
 include/net/tc_act/tc_ct.h                  |   1 +
 include/uapi/linux/tc_act/tc_ct.h           |   3 +
 net/netfilter/nf_conntrack_helper.c         |  71 ++++++++++
 net/openvswitch/conntrack.c                 |  61 +-------
 net/sched/act_ct.c                          | 148 +++++++++++++++++---
 6 files changed, 204 insertions(+), 82 deletions(-)

-- 
2.31.1