Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Aaron Conole <aconole@redhat.com>
To:     netdev@vger.kernel.org
Cc:     Pravin B Shelar <pshelar@ovn.org>,
        "David S . Miller" <davem@davemloft.net>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>, dev@openvswitch.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH net 1/2] openvswitch: support asymmetric conntrack
Date:   Fri,  8 Nov 2019 16:07:13 -0500
Message-Id: <20191108210714.12426-1-aconole@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=WINDOWS-1252
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The openvswitch module shares a common conntrack and NAT infrastructure
exposed via netfilter.  It's possible that a packet needs both SNAT and
DNAT manipulation, due to e.g. tuple collision.  Netfilter can support
this because it runs through the NAT table twice - once on ingress and
again after egress.  The openvswitch module doesn't have such capability.

Like netfilter hook infrastructure, we should run through NAT twice to
keep the symmetry.

Fixes: 05752523e565 ("openvswitch: Interface with NAT.")
Signed-off-by: Aaron Conole <aconole@redhat.com>
---
 net/openvswitch/conntrack.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 05249eb45082..283e8f9a5fd2 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -903,6 +903,17 @@ static int ovs_ct_nat(struct net *net, struct sw_flow_=
key *key,
 =09}
 =09err =3D ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
=20
+=09if (err =3D=3D NF_ACCEPT &&
+=09    ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
+=09=09if (maniptype =3D=3D NF_NAT_MANIP_SRC)
+=09=09=09maniptype =3D NF_NAT_MANIP_DST;
+=09=09else
+=09=09=09maniptype =3D NF_NAT_MANIP_SRC;
+
+=09=09err =3D ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
+=09=09=09=09=09 maniptype);
+=09}
+
 =09/* Mark NAT done if successful and update the flow key. */
 =09if (err =3D=3D NF_ACCEPT)
 =09=09ovs_nat_update_key(key, skb, maniptype);
--=20
2.21.0