netdev - Re: [PATCH nf] netfilter: restore default behavior for nf_conntrack

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Message-ID: <ZpUwD_KJAmRXBdnv@calendula>
Date: Mon, 15 Jul 2024 16:19:59 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: Nicolas Dichtel <nicolas.dichtel@...nd.com>
Cc: Florian Westphal <fw@...len.de>, netdev@...r.kernel.org,
	netfilter-devel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH nf] netfilter: restore default behavior for
 nf_conntrack_events

On Wed, Jul 03, 2024 at 09:37:59AM +0200, Nicolas Dichtel wrote:
> Hi Pablo,
> 
> Le 26/06/2024 à 13:41, Pablo Neira Ayuso a écrit :
> > Hi Nicolas,
> > 
> > On Tue, Jun 04, 2024 at 03:54:38PM +0200, Nicolas Dichtel wrote:
> >> Since the below commit, there are regressions for legacy setups:
> >> 1/ conntracks are created while there are no listener
> >> 2/ a listener starts and dumps all conntracks to get the current state
> >> 3/ conntracks deleted before the listener has started are not advertised
> >>
> >> This is problematic in containers, where conntracks could be created early.
> >> This sysctl is part of unsafe sysctl and could not be changed easily in
> >> some environments.
> >>
> >> Let's switch back to the legacy behavior.
> > 
> > Maybe it is possible to annotate destroy events in a percpu area if
> > the conntrack extension is not available. This code used to follow
> > such approach time ago.
>
> Thanks for the feedback. I was wondering if just sending the destroy event would
> be possible. TBH, I'm not very familiar with this part of the code, I need to
> dig a bit. I won't have time for this right now, any help would be appreciated.

I will take a look and get back to you.