From: Aaron Conole aconole@redhat.com
[ Upstream commit 95219afbb980f10934de9f23a3e199be69c5ed09 ]
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 Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/act_ct.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
--- 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 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 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