netdev - Re: [PATCH 1/1] netfilter: Add possibility to turn off netfilters defrag per netns

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Date:	Wed, 4 Jan 2012 22:15:10 +0100
From:	Hans Schillstrom <hans@...illstrom.com>
To:	Pablo Neira Ayuso <pablo@...filter.org>
Cc:	Hans Schillstrom <hans.schillstrom@...csson.com>,
	Jan Engelhardt <jengelh@...ozas.de>,
	Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu>,
	Patrick McHardy <kaber@...sh.net>,
	"netfilter-devel@...r.kernel.org" <netfilter-devel@...r.kernel.org>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH 1/1] netfilter: Add possibility to turn off netfilters defrag per netns

Hello Again

On Wednesday, January 04, 2012 18:40:35 Pablo Neira Ayuso wrote:
> On Wed, Jan 04, 2012 at 12:48:35PM +0100, Hans Schillstrom wrote:
> > I like that idea, an "early" table at prio -500 with PREROUTING.
> > There is also a need for a new flag "--allfrags"
> > i.e. all fragments needs to be sorted out and sent to same dest for defrag.
> > 
> > ex.
> > iptables -t early -A PREROUTING -i eth0 --allfrags -j NOTRACK
> 
> New tables add too much overhead. We have discussed this before with
> Patrick.
> 
Only if loaded .. 
It would have been the perfect solution.
Is the discussion about the overhead on the list (I can't find it)?

I made a quick test with an "early" table
and --allfrags fix (for IPv4) and it works really good.

iptables -t early -A PREROUTING -i eth0 -a -j NOTRACK
iptables -t mangle -A PREROUTING -i eth0 -a -j HMARK --mod 3 --offs 100

So your opinion is no more tables,
even if it's rare that it is loaded?

Regards
Hans

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