nusid...@redhat.com <nusid...@redhat.com> wrote:
> From: Numan Siddique <nusid...@redhat.com>
>
> Before calling nf_conntrack_in(), caller can set this flag in the
> connection template for a tcp packet and any errors in the
> tcp_in_window() will be ignored.
>
> A helper function - nf_ct_set_tcp_be_liberal(nf_conn) is added which
> sets this flag for both the directions of the nf_conn.
>
> openvswitch makes use of this feature so that any out of window tcp
> packets are not marked invalid. Prior to this there was no easy way
> to distinguish if conntracked packet is marked invalid because of
> tcp_in_window() check error or because it doesn't belong to an
> existing connection.
>
> An earlier attempt (see the link) tried to solve this problem for
> openvswitch in a different way. Florian Westphal instead suggested
> to be liberal in openvswitch for tcp packets.
>
> Link:
> https://patchwork.ozlabs.org/project/netdev/patch/20201006083355.121018-1-nusid...@redhat.com/
>
> Suggested-by: Florian Westphal <f...@strlen.de>
> Signed-off-by: Numan Siddique <nusid...@redhat.com>
> ---
> include/net/netfilter/nf_conntrack_l4proto.h | 6 ++++++
> net/netfilter/nf_conntrack_core.c | 13 +++++++++++--
> net/openvswitch/conntrack.c | 1 +
> 3 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/netfilter/nf_conntrack_l4proto.h
> b/include/net/netfilter/nf_conntrack_l4proto.h
> index 88186b95b3c2..572ae8d2a622 100644
> --- a/include/net/netfilter/nf_conntrack_l4proto.h
> +++ b/include/net/netfilter/nf_conntrack_l4proto.h
> @@ -203,6 +203,12 @@ static inline struct nf_icmp_net
> *nf_icmpv6_pernet(struct net *net)
> {
> return &net->ct.nf_ct_proto.icmpv6;
> }
> +
> +static inline void nf_ct_set_tcp_be_liberal(struct nf_conn *ct)
> +{
> + ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
> + ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
> +}
> #endif
>
> #ifdef CONFIG_NF_CT_PROTO_DCCP
> diff --git a/net/netfilter/nf_conntrack_core.c
> b/net/netfilter/nf_conntrack_core.c
> index 234b7cab37c3..8290c5b04e88 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -1748,10 +1748,18 @@ static int nf_conntrack_handle_packet(struct nf_conn
> *ct,
> struct sk_buff *skb,
> unsigned int dataoff,
> enum ip_conntrack_info ctinfo,
> - const struct nf_hook_state *state)
> + const struct nf_hook_state *state,
> + union nf_conntrack_proto *tmpl_proto)
I would prefer if we could avoid adding yet another function argument.
AFAICS its enough to call the new nf_ct_set_tcp_be_liberal() helper
before nf_conntrack_confirm() in ovs_ct_commit(), e.g.:
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1235,10 +1235,13 @@ static int ovs_ct_commit(struct net *net, struct
sw_flow_key *key,
if (!nf_ct_is_confirmed(ct)) {
err = ovs_ct_init_labels(ct, key, &info->labels.value,
&info->labels.mask);
if (err)
return err;
+
+ if (nf_ct_protonum(ct) == IPPROTO_TCP)
+ nf_ct_set_tcp_be_liberal(ct);
_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
