Subject: Re: [PATCH 1/2] ipv6: addrconf: fix mcast route for GRE devices

From: Hannes Frederic Sowa <[email-masked]>
Date: Fri, 01 Aug 2014 00:05:25 +0200

Hi David,

Next time please also specify which tree you want this patch applied to.
We use [PATCH net] for patches which should go into the rc2+ and [PATCH
net-next] for rc1. Thanks!

On Do, 2014-07-31 at 22:53 +0200, David Lamparter wrote:
> GRE devices, for some reason, were coming up with an autoconfigured
> address, but no ff00::/8 route in the local table.  This breaks any kind
> of multicast, in particular OSPFv3, mDNS, - and ND.  In fact, IPv6 only
> works at all because there is little need for ND on PtP devices.
> 
> Adding any other IPv6 address on the device from userspace would rectify
> this issue through inet6_addr_add()/addrconf_add_dev() - and would leave
> the route around even if the address was later removed.  (This is
> probably why this issue was not discovered earlier.  AFAICS it has been
> there from the beginning, e.g. aee80b5 "generate link local address for
> GRE tunnel")
> 
> (Note: multicast is supported on GRE devices of all kinds, including PtP
> GRE, P-t-Mcast GRE and NBMA-GRE.)
> 
> Fixes: aee80b54b235 (ipv6: generate link local address for GRE tunnel)
> Signed-off-by: David Lamparter <[email-masked]>
> Cc: Hannes Frederic Sowa <[email-masked]>
> Cc: Stephen Hemminger <[email-masked]>
> Cc: Nicolas Dichtel <[email-masked]>

Acked-by: Hannes Frederic Sowa <[email-masked]>

Dave, it would make sense to queue this up for net and stable (or only
net-next if there is no merge before the release).

Thanks,
Hannes