Re: [PATCH] ipv6: icmp6: Allow icmp messages to be looped back

From: David Miller
Date: Sat Dec 16 2017 - 22:52:42 EST


From: Brendan McGrath <redmcg@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxx>

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

Applied, thank you.