From: Florian Westphal <fw@strlen.de>
To: nusiddiq@redhat.com
Cc: dev@openvswitch.org, netdev@vger.kernel.org,
Pravin B Shelar <pshelar@ovn.org>,
Florian Westphal <fw@strlen.de>
Subject: Re: [net-next] netfiler: conntrack: Add the option to set ct tcp flag - BE_LIBERAL per-ct basis.
Date: Mon, 9 Nov 2020 22:35:57 +0100 [thread overview]
Message-ID: <20201109213557.GE23619@breakpoint.cc> (raw)
In-Reply-To: <20201109072930.14048-1-nusiddiq@redhat.com>
nusiddiq@redhat.com <nusiddiq@redhat.com> wrote:
> From: Numan Siddique <nusiddiq@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-nusiddiq@redhat.com/
>
> Suggested-by: Florian Westphal <fw@strlen.de>
> Signed-off-by: Numan Siddique <nusiddiq@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);
next prev parent reply other threads:[~2020-11-09 21:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-09 7:29 [net-next] netfiler: conntrack: Add the option to set ct tcp flag - BE_LIBERAL per-ct basis nusiddiq
2020-11-09 19:54 ` Jakub Kicinski
2020-11-10 8:39 ` Numan Siddique
2020-11-09 21:35 ` Florian Westphal [this message]
2020-11-10 8:47 ` Numan Siddique
2020-11-10 12:25 ` Florian Westphal
2020-11-10 12:58 ` Numan Siddique
2020-11-10 13:11 ` Florian Westphal
2020-11-16 13:06 ` Numan Siddique
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201109213557.GE23619@breakpoint.cc \
--to=fw@strlen.de \
--cc=dev@openvswitch.org \
--cc=netdev@vger.kernel.org \
--cc=nusiddiq@redhat.com \
--cc=pshelar@ovn.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).