On Sun, 16 Jul 2023 17:09:16 -0400 Xin Long wrote: > With the OVS upcall, the original ct in the skb will be dropped, and when > the skb comes back from userspace it has to create a new ct again through > nf_conntrack_in() in either OVS __ovs_ct_lookup() or TC tcf_ct_act(). > > However, the new ct will not be able to have the exp as the original ct > has taken it away from the hash table in nf_ct_find_expectation(). This > will cause some flow never to be matched, like: > > 'ip,ct_state=-trk,in_port=1 actions=ct(zone=1)' > 'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=1)' > 'ip,ct_state=+trk+new+rel,in_port=1 actions=ct(commit,zone=2),normal' > > if the 2nd flow triggers the OVS upcall, the 3rd flow will never get > matched. > > OVS conntrack works around this by adding its own exp lookup function to > not remove the exp from the hash table and saving the exp and its master > info to the flow keys instead of create a real ct. But this way doesn't > work for TC act_ct. > > The patch 1/3 allows nf_ct_find_expectation() not to remove the exp from > the hash table if tmpl is set with IPS_CONFIRMED when doing lookup. This > allows both OVS conntrack and TC act_ct to have a simple and clear fix > for this problem in the patch 2/3 and 3/3.
Florian, Pablo, any opinion on these? Would you prefer to take them via netfilter? _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
