From: Florian Westphal <fw@strlen•de>
To: Jozsef Kadlecsik <kadlec@blackhole•kfki.hu>
Cc: Florian Westphal <fw@strlen•de>, yyxRoy <yyxroy22@gmail•com>,
pablo@netfilter•org, gregkh@linuxfoundation•org,
davem@davemloft•net, edumazet@google•com, kuba@kernel•org,
pabeni@redhat•com, netfilter-devel@vger•kernel.org,
coreteam@netfilter•org, netdev@vger•kernel.org,
linux-kernel@vger•kernel.org, yyxRoy <979093444@qq•com>
Subject: Re: [PATCH] netfilter: conntrack: tcp: do not lower timeout to CLOSE for in-window RSTs
Date: Sat, 6 Jul 2024 19:04:32 +0200 [thread overview]
Message-ID: <20240706170432.GA7766@breakpoint.cc> (raw)
In-Reply-To: <1173262c-a471-683f-9e00-abc8192c9ca8@blackhole.kfki.hu>
Jozsef Kadlecsik <kadlec@blackhole•kfki.hu> wrote:
> I fully agree with Florian: conntrack plays the role of a middle box and
> cannot absolutely know the right seq/ack numbers of the client/server
> sides. Add NAT on top of that and there are a couple of ways to attack a
> given traffic. I don't see a way by which the checkings/parameters could
> be tightened without blocking real traffic.
I forgot about TCP timestamps, which we do not track at the moment.
But then there is a slight caveat: if one side exits, RST won't
carry timestamp option, so even keeping track of timestamps will help
:-(
next prev parent reply other threads:[~2024-07-06 17:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-05 4:00 [PATCH] netfilter: conntrack: tcp: do not lower timeout to CLOSE for in-window RSTs yyxRoy
2024-07-05 9:43 ` Florian Westphal
2024-07-06 16:16 ` Jozsef Kadlecsik
2024-07-06 17:04 ` Florian Westphal [this message]
2024-07-08 8:59 ` yyxRoy
2024-07-08 14:12 ` Florian Westphal
2024-07-10 9:45 ` yyxRoy
2024-07-10 13:49 ` Jozsef Kadlecsik
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