[PATCH 1/2] openvswitch: support asymmetric conntrack

[PATCH 1/2] openvswitch: support asymmetric conntrack

[Aaron Conole]

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>
---
NOTE: this is a repost to see if the email client issues go away.

 net/openvswitch/conntrack.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index df9c80bf621d..e726159cfcfa 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,
 	}
 	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);
-- 
2.21.0

[PATCH 2/2] act_ct: support asymmetric conntrack

[Aaron Conole]

The act_ct TC 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 act_ct action doesn't have such capability.

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

Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")

Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
NOTE: this is a repost to see if the email client issues go away.

 net/sched/act_ct.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index ae0de372b1c8..bf2d69335d4b 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -329,6 +329,7 @@ static int tcf_ct_act_nat(struct sk_buff *skb,
 			  bool commit)
 {
 #if IS_ENABLED(CONFIG_NF_NAT)
+	int err;
 	enum nf_nat_manip_type maniptype;
 
 	if (!(ct_action & TCA_CT_ACT_NAT))
@@ -359,7 +360,17 @@ static int tcf_ct_act_nat(struct sk_buff *skb,
 		return NF_ACCEPT;
 	}
 
-	return ct_nat_execute(skb, ct, ctinfo, range, maniptype);
+	err = ct_nat_execute(skb, ct, ctinfo, 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 = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
+	}
+	return err;
 #else
 	return NF_ACCEPT;
 #endif
-- 
2.21.0

Re: [PATCH 2/2] act_ct: support asymmetric conntrack

[David Miller]

From: Aaron Conole <aconole@redhat.com>
Date: Tue,  3 Dec 2019 16:34:14 -0500

> The act_ct TC 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 act_ct action doesn't have such capability.
> 
> Like netfilter hook infrastructure, we should run through NAT twice to
> keep the symmetry.
> 
> Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct")
> 
> Signed-off-by: Aaron Conole <aconole@redhat.com>
> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> ---
> NOTE: this is a repost to see if the email client issues go away.

Applied and queued up for -stable.

Next time, please:

1) Provide an introductory posting ala "[PATCH net 0/N] ..." describing
   what the patch series does on a high level, how it is doing it, and
   why it is doing it that way.

   This allows people to understand what they are about to read, and it
   gives me a single mail to respon to when I apply your entire series.

2) Always clearly indicate the target GIT tree in your Subject line,
   in these cases it should have been "[PATCH net N/M]"

Thank you.

Re: [PATCH 1/2] openvswitch: support asymmetric conntrack

[David Miller]

From: Aaron Conole <aconole@redhat.com>
Date: Tue,  3 Dec 2019 16:34:13 -0500

> 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>
> ---
> NOTE: this is a repost to see if the email client issues go away.

Applied and queued up for -stable.