linux-kernel - Re: [PATCH] net: Remove a noisy printk

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Date:	Mon, 15 Dec 2008 14:25:04 +0100 (CET)
From:	Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu>
To:	Patrick McHardy <kaber@...sh.net>
cc:	Jan Engelhardt <jengelh@...ozas.de>,
	David Miller <davem@...emloft.net>, ajax@...hat.com,
	linux-kernel@...r.kernel.org, davej@...hat.com,
	netdev@...r.kernel.org, netfilter-devel@...r.kernel.org
Subject: Re: [PATCH] net: Remove a noisy printk

On Mon, 15 Dec 2008, Patrick McHardy wrote:

> Jozsef Kadlecsik wrote:
> > On Sun, 14 Dec 2008, Jan Engelhardt wrote:
> > 
> > > > In a >normal< system one usually does not use raw sockets. So if a root
> > > > process do use raw socket, at least netfilter sends a notification and
> > > > there's a chance that someone take notice it by checking the kernel
> > > > logs.
> > > > [...]
> > > > But should we remove them due to nuisances on >test< systems?
> > > > 
> > > > Rather make it a kernel compile option but do not remove.
> > > This warning is in the conntrack calling code. Iff you play with
> > > raw sockets and do something wrong, the generic network code
> > > should barf IMHO, not nf_conntrack, and not [nf_conntrack_ipv4 only].
> > 
> > It is not about doing something wrong at using raw sockets - it's about
> > using raw sockets.
> > 
> > I'm not quite convinced the generic network code should warn about raw
> > sockets. I believe it belongs to the security-related subsystems - netfilter
> > and (or) the security frameworks. [But as netfilter is much more widely
> > used, the 'or' is just theoretical.)
> 
> I agree that it doesn't belong to the generic networking code.
> But the way its handled in netfilter is far from perfect as well.
> Currently multiple modules will spam the ringbuffer repeatedly,
> but offer no possibility to change anything in the behaviour of
> how these packets are treated. Unfortunately we can't handle this
> in the ruleset (which is exactly the reason why we're spamming
> the ringbuffer), so how about we add a module option controlling
> how to treat those packets and remove the printk?

How about this: let the printk be removed from conntrack and the mangle 
table but put (back) into the filter table with a module option, which 
controls the behaviour (drop/accept & log/nolog)?

Best regards,
Jozsef
-
E-mail  : kadlec@...ckhole.kfki.hu, kadlec@...l.kfki.hu
PGP key : http://www.kfki.hu/~kadlec/pgp_public_key.txt
Address : KFKI Research Institute for Particle and Nuclear Physics
          H-1525 Budapest 114, POB. 49, Hungary
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