[PATCH nf] netfilter: nft_flow_offload: add entry to flowtable after confirmation

[Pablo Neira Ayuso]

This is fixing flow offload for UDP traffic where packets only follow
one single direction.

The nf_ct_tcp_fixup() mechanism works fine in case that the offloaded
entry remains in SYN_RECV state, given sequence tracking is reset and
that conntrack handles syn+ack packets as a retransmission, ie.

        sES + synack => sIG

for reply traffic.

Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 net/netfilter/nft_flow_offload.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 6e6b9adf7d38..8968c7f5a72e 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -94,8 +94,7 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
        if (help)
                goto out;
 
-       if (ctinfo == IP_CT_NEW ||
-           ctinfo == IP_CT_RELATED)
+       if (!nf_ct_is_confirmed(ct))
                goto out;
 
        if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
-- 
2.11.0