From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH RESEND v2] ipv4: Do not cache routing failures due to
 disabled forwarding.
Date: Thu, 30 Oct 2014 19:21:15 -0400 (EDT)
Message-ID: <20141030.192115.918754566952396661.davem@davemloft.net>
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	<1414660193-4177-1-git-send-email-nicolas.cavallari@green-communications.fr>
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Cc: kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org,
	kaber@trash.net, netdev@vger.kernel.org,
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To: nicolas.cavallari@green-communications.fr
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From: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Date: Thu, 30 Oct 2014 10:09:53 +0100

> If we cache them, the kernel will reuse them, independently of
> whether forwarding is enabled or not.  Which means that if forwarding is
> disabled on the input interface where the first routing request comes
> from, then that unreachable result will be cached and reused for
> other interfaces, even if forwarding is enabled on them.  The opposite
> is also true.
> 
> This can be verified with two interfaces A and B and an output interface
> C, where B has forwarding enabled, but not A and trying
> ip route get $dst iif A from $src && ip route get $dst iif B from $src
> 
> Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
> Reviewed-by: Julian Anastasov <ja@ssi.bg>

Applied and queued up for -stable, thanks.