From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lamparter Subject: Re: [PATCH v2] ipv6: addrconf: fix mcast route for GRE devices Date: Thu, 31 Jul 2014 22:19:26 +0200 Message-ID: <20140731201926.GA754314@jupiter.n2.diac24.net> References: <20140730153503.GJ801478@jupiter.n2.diac24.net> <1406734797-122248-1-git-send-email-equinox@diac24.net> <20140731.120652.225147288366144806.davem@davemloft.net> <1406835454.13603.1.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , equinox@diac24.net, netdev@vger.kernel.org, stephen@networkplumber.org To: Hannes Frederic Sowa Return-path: Received: from spaceboyz.net ([87.106.131.203]:54126 "EHLO spaceboyz.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750836AbaGaUTs (ORCPT ); Thu, 31 Jul 2014 16:19:48 -0400 Content-Disposition: inline In-Reply-To: <1406835454.13603.1.camel@localhost> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Jul 31, 2014 at 09:37:34PM +0200, Hannes Frederic Sowa wrote: > On Do, 2014-07-31 at 12:06 -0700, David Miller wrote: > > From: David Lamparter > > Date: Wed, 30 Jul 2014 17:39:57 +0200 > > > > > 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 > > > Cc: Hannes Frederic Sowa > > > Cc: Stephen Hemminger > > > > Hannes, are you OK with this version? Please ACK if so. > > The alternate version does provide the same semantic change and makes > the code more readable. Both changes are technically correct, I acked > the alternate version already. Give me a few min, I'll go base the other one on this one, that way there's one 2-line patch changing semantics (this one) and another 50-line patch just mechanically moving stuff around. -David