From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chas Williams <3chas3@gmail.com> Subject: Re: [PATCH] team: set IFF_SLAVE on team ports Date: Mon, 1 Oct 2018 10:06:16 -0400 Message-ID: References: <1436435914-8903-1-git-send-email-jblunck@infradead.org> <20150709100727.GE2270@nanopsycho.orion> <20150710064147.GA2204@nanopsycho.orion> <20180930071414.GF2209@nanopsycho.orion> <20180930113805.3b8e62a1@shemminger-XPS-13-9360> <20180930093452.GG2209@nanopsycho.orion> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Jan Blunck , LKML , netdev@vger.kernel.org To: Jiri Pirko , Stephen Hemminger Return-path: Received: from mail-qt1-f196.google.com ([209.85.160.196]:32953 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728979AbeJAUoR (ORCPT ); Mon, 1 Oct 2018 16:44:17 -0400 In-Reply-To: <20180930093452.GG2209@nanopsycho.orion> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 09/30/18 05:34, Jiri Pirko wrote: > Sun, Sep 30, 2018 at 11:38:05AM CEST, stephen@networkplumber.org wrote: >> On Sun, 30 Sep 2018 09:14:14 +0200 >> Jiri Pirko wrote: >> >>> Thu, Sep 27, 2018 at 04:04:26PM CEST, 3chas3@gmail.com wrote: >>>> >>>> >>>> On 07/10/15 02:41, Jiri Pirko wrote: >>>>> Thu, Jul 09, 2015 at 05:36:55PM CEST, jblunck@infradead.org wrote: >>>>>> On Thu, Jul 9, 2015 at 12:07 PM, Jiri Pirko wrote: >>>>>>> Thu, Jul 09, 2015 at 11:58:34AM CEST, jblunck@infradead.org wrote: >>>>>>>> The code in net/ipv6/addrconf.c:addrconf_notify() tests for IFF_SLAVE to >>>>>>>> decide if it should start the address configuration. Since team ports >>>>>>>> shouldn't get link-local addresses assigned lets set IFF_SLAVE when linking >>>>>>>> a port to the team master. >>>>>>> >>>>>>> I don't want to use IFF_SLAVE in team. Other master-slave devices are >>>>>>> not using that as well, for example bridge, ovs, etc. >>>>>>> >>>>>> >>>>>> Maybe they need to get fixed too. I've used that flag because it is >>>>>> documented as >>>>>> a "slave of a load balancer" which describes what a team port is. >>>>>> >>>>>> >>>>>>> I think that this should be fixed in addrconf_notify. It should lookup >>>>>>> if there is a master on top and bail out in that case. >>>>>> >>>>>> There are other virtual interfaces that have a master assigned and want to >>>>>> participate in IPv6 address configuration. >>>>> >>>>> Can you give me an example? >>>> >>>> I would like to revisit this patch (yes, I know it has been a while). I >>>> believe the VRF implementation uses master to group the interfaces under >>>> a single interface. >>>> >>>> I don't see a reason not to use IFF_SLAVE since team and bonding are fairly >>>> similar. >>> >>> Again, why do you need team port to have IFF_SLAVE flag? What do you >>> want to achieve >> >> Without setting this flag IPv6 will try and make a link specific address. > > Why is it not an issue with bridge, ovs, and other master-slave devices? > It very well might be an issue for bridge and ovs. Other master-slave devices include the existing VRF implementation in the kernel and those slave interfaces will certainly want to use IPv6. However, IFF_SLAVE has a specific meaning: ./include/uapi/linux/if.h: * @IFF_SLAVE: slave of a load balancer. Volatile. The bonding driver is not the only user: ./drivers/net/eql.c:#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE) ./drivers/net/eql.c: slave->dev->flags &= ~IFF_SLAVE; ./drivers/net/eql.c: slave->dev->flags |= IFF_SLAVE; The team driver would like to use this same flag since it is a load balancer as well. The side effect of not assigning IPv6 is a bonus. The fact that bridges and ovs are also likely broken is a different issue. Should there be a another flag that says "layer 2 only"? Very possibly, but that is something all these interfaces should be using to include bonding, team, eql, obs, bridge etc. That's not a reasonable objection to labeling the team slave as slaves since they are literally slaves of a load balancer.