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From: Patrick McHardy <kaber@trash.net>
To: Jan Engelhardt <jengelh@computergmbh.de>
Cc: Casper Gripenberg <casper.gripenberg@kotiportti.fi>,
	netfilter-devel@vger.kernel.org
Subject: Re: Bug in bridge or netfilter code (REJECT + incorrect MAC)?
Date: Wed, 02 Apr 2008 13:18:28 +0200	[thread overview]
Message-ID: <47F36B84.5070708@trash.net> (raw)
In-Reply-To: <alpine.LNX.1.10.0804021312280.6604@fbirervta.pbzchgretzou.qr>

Jan Engelhardt wrote:
> 
> On Wednesday 2008-04-02 13:06, Patrick McHardy wrote:
>>>
>>>  The router is my ISP's internet router, which I do not
>>>  control. But I doubt the router is doing anything wrong
>>>  though. The weirdness is more on the Linux side..
>>
>> Sure, for full transparency the packets should ideally use
>> the original source MAC address. I'll see if I can come
>> up with a patch for this.
> 
> The problem is an interesting one. REJECT itself does not fill
> in the MAC address, and probably should not try (there is more
> than just Ethernet). Yet the routing code is so deeply buried
> that drawing a seam through the entire call chain seems intrusive.
> </random thoughts>


One way is to have REJECT specifically handle the bridging case
by setting up an appropriate skb->nf_bridge struct, which will
make the bridging code fill in the correct MAC address. For
REJECT this would be borderline OK, but icmp_send really shouldn't
care about this, so a generic method would be preferrable.

  reply	other threads:[~2008-04-02 11:18 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-01 17:34 Bug in bridge or netfilter code (REJECT + incorrect MAC)? Casper Gripenberg
2008-04-02 10:43 ` Patrick McHardy
2008-04-02 10:56   ` Casper Gripenberg
2008-04-02 11:06     ` Patrick McHardy
2008-04-02 11:15       ` Jan Engelhardt
2008-04-02 11:18         ` Patrick McHardy [this message]
2008-04-24  3:47         ` Patrick McHardy

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