Date: Sat, 16 Dec 2017 22:52:12 -0500 (EST)
Message-Id: <20171216.225212.1791534849895795249.davem@davemloft.net>
To: redmcg@redmandi.dyndns.org
Cc: kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ipv6: icmp6: Allow icmp messages to be looped back
From: David Miller <davem@davemloft.net>
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From: Brendan McGrath <redmcg@redmandi.dyndns.org>
Date: Wed, 13 Dec 2017 22:14:57 +1100

> One example of when an ICMPv6 packet is required to be looped back is
> when a host acts as both a Multicast Listener and a Multicast Router.
> 
> A Multicast Router will listen on address ff02::16 for MLDv2 messages.
> 
> Currently, MLDv2 messages originating from a Multicast Listener running
> on the same host as the Multicast Router are not being delivered to the
> Multicast Router. This is due to dst.input being assigned the default
> value of dst_discard.
> 
> This results in the packet being looped back but discarded before being
> delivered to the Multicast Router.
> 
> This patch sets dst.input to ip6_input to ensure a looped back packet
> is delivered to the Multicast Router.
> 
> Signed-off-by: Brendan McGrath <redmcg@redmandi.dyndns.org>

Ok, after a lot of consideration this seems like a reasonable way to
solve this problem.

Applied, thank you.