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From: Lennart Poettering <lennart@poettering.net>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org, kernel@linuxace.com
Subject: Re: [PATCH iptables] iptables: use flock() instead of abstract unix sockets
Date: Mon, 19 Jan 2015 19:36:20 +0100	[thread overview]
Message-ID: <20150119183620.GA32042@gardel-login> (raw)
In-Reply-To: <1421690957-11279-1-git-send-email-pablo@netfilter.org>

On Mon, 19.01.15 19:09, Pablo Neira Ayuso (pablo@netfilter.org) wrote:

> Abstract unix sockets cannot be used to synchronize several concurrent
> instances of iptables since an unpriviledged process can create them and
> prevent the legitimate iptables instance from running.
> 
> Use flock() and /run instead as suggested by Lennart Poettering.

Looks OK. Of course, it's a bit nasty to do the sleep() loop, but
there is no time-limited version of flock(), hence doing the sleep()
loop is kinda necessary, unless one wants to use SIGARLM, but that's
awful to do without races...

Hence, looks OK to me.

A minor optimization might be to move the lock file into its own
subdir /run/iptables/ or so, but it's OK if you don't.

Lennart

-- 
Lennart Poettering, Red Hat

  reply	other threads:[~2015-01-19 18:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-19 18:09 [PATCH iptables] iptables: use flock() instead of abstract unix sockets Pablo Neira Ayuso
2015-01-19 18:36 ` Lennart Poettering [this message]
2015-01-24 22:35 ` Phil Oester

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