Commit 5d50aa83 authored Dec 03, 2019 by Aaron Conole Committed by David S. Miller Dec 04, 2019

openvswitch: support asymmetric conntrack



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: 05752523 ("openvswitch: Interface with NAT.")
Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 7b3b209e

net/openvswitch/conntrack.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -903,6 +903,17 @@ static int ovs_ct_nat(struct net net, struct sw_flow_key key,
		}
		err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);

		if (err == NF_ACCEPT &&
		ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
		if (maniptype == NF_NAT_MANIP_SRC)
		maniptype = NF_NAT_MANIP_DST;
		else
		maniptype = NF_NAT_MANIP_SRC;

		err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range,
		maniptype);
		}

		/* Mark NAT done if successful and update the flow key. */
		if (err == NF_ACCEPT)
		ovs_nat_update_key(key, skb, maniptype);

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