From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: RFC: bridge get fdb by bridge device Date: Tue, 11 Feb 2014 12:30:29 -0800 Message-ID: <52FA8865.1070302@intel.com> References: <52F21F72.2090405@mojatatu.com> <52F29747.7040008@redhat.com> <52F3CF76.9090404@mojatatu.com> <52F3E357.4040006@redhat.com> <52F79990.3000400@mojatatu.com> <52F8FEF1.60407@redhat.com> <52FA58E9.906@mojatatu.com> <52FA6A24.3030402@redhat.com> <52FA84FA.2030608@mojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: vyasevic@redhat.com, "netdev@vger.kernel.org" , Stephen Hemminger , Scott Feldman To: Jamal Hadi Salim Return-path: Received: from mga09.intel.com ([134.134.136.24]:35707 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754619AbaBKUab (ORCPT ); Tue, 11 Feb 2014 15:30:31 -0500 In-Reply-To: <52FA84FA.2030608@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2/11/2014 12:15 PM, Jamal Hadi Salim wrote: > On 02/11/14 13:21, Vlad Yasevich wrote: >> On 02/11/2014 12:07 PM, Jamal Hadi Salim wrote: >>> On 02/10/14 11:31, Vlad Yasevich wrote: > >> No, this was more the point that the current iproute code sends an >> ifinfomsg struct down, and you change that to send ndmsg struct. >> This is risky, but we luck out since the index is at the same offset >> in both structs. >> > > ah, ok, thanks for catching that. I should have said something - the > original code was wrong and i felt it was safe to make the change > given that the kernel code never even looked at what was being > sent to it. There is asymetry desires which are violated. > It doesnt make sense to send and ifm and expect back an ndm. > I should send that separately as a bug fix. > > >> But that would only happen if the user said: >> # bridge fdb show br eth0 >> >> If eth0 in this case is a hw bridge device, getting the device's >> version of fdb data is exactly what would be expected, isn't it? >> > > Well, if it is a "bridge device" why would it not be tagged as a bridge > device? What do you mean by "bridge device" are you specifically talking about IFF_BRIDGE flag? This flag is used only for ./net/bridge devices. For example macvlan uses its own flag. I think there is a good case to be made for netdevices which are acting as the management interface for a hardware bridge to set an identifying flag. Perhaps IFF_HWBRIDGE. > >> If you mean a 'software bridge' above, then that's not an issue >> since that's a disallowed config. You can't stack software bridges >> without something in the middle like bond or vlan. >> > > Ok, didnt realize that. > So i cant add a bridge as a bridge port to another bridge? > # ip link set dev bridge0 master bridge1 RTNETLINK answers: Too many levels of symbolic links in the bridge case this doesn't work. But you can stack a macvlan on top of the bridge port, # ip link add link bridge0 type macvlan mode vepa 11: macvlan0@bridge0: mtu 1500 qdisc noop state DOWN mode DEFAULT group default And macvlans on macvlans is OK as well. # ip link add link macvlan0 type macvlan mode vepa [...] >> When you configure multiple macvlan devices on top of the >> same hw device, one could think of the hw device as a sort >> of a bridge. It's not really, but you could define it in >> those terms. The fdb entries, in this case, contain the mac >> addresses of the macvlan devices. >> > > It certainly has some equivalent semantics (looks at dst MAC then > picks the port). Possible to add Vlans as well? > Why dont we tag such a thing as a bridge then? > If its useful then we should. You can track them down in userspace via /sys/class/net/ or looking for offloaded netdevices that point to the interface but a flag is definitely more direct. >> >> Sorry, I wasn't very clear. What I meant was that you now support >> # bridge fdb show port <> >> >> The usage message should reflect it. >> > > Sorry - I noticed the word "port" at exactly where your quote came. > So i thought you noticed that "port" was already taken - it is used > for VXLAN fdb entries (for udp ports). > > > cheers, > jamal