From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940576AbdAGPG5 (ORCPT ); Sat, 7 Jan 2017 10:06:57 -0500 Received: from mail.aperture-lab.de ([138.201.29.205]:32958 "EHLO mail.aperture-lab.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933332AbdAGPGl (ORCPT ); Sat, 7 Jan 2017 10:06:41 -0500 Date: Sat, 7 Jan 2017 16:06:34 +0100 From: Linus =?utf-8?Q?L=C3=BCssing?= To: Stephen Hemminger Cc: netdev@vger.kernel.org, "David S . Miller" , bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, Felix Fietkau Subject: Re: [PATCH net-next] bridge: multicast to unicast Message-ID: <20170107150634.GF3134@otheros> References: <20170102193214.31723-1-linus.luessing@c0d3.blue> <20170106191356.43740a26@xeon-e3> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170106191356.43740a26@xeon-e3> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 06, 2017 at 07:13:56PM -0800, Stephen Hemminger wrote: > On Mon, 2 Jan 2017 20:32:14 +0100 > Linus Lüssing wrote: > > > This feature is intended for interface types which have a more reliable > > and/or efficient way to deliver unicast packets than broadcast ones > > (e.g. wifi). > > > Why is this not done in MAC80211 rather than bridge? Because mac80211 does not have the IGMP/MLD snooping code as the bridge has? Reimplementing the snooping in mac80211 does not make sense because of duplicating code. Moving the snooping code from the bridge to mac80211 does not make sense either, because we want multicast snooping, software based, (virtually) wired switches, too. The "best way" (TM) would probably be to migrate the IGMP/MLD snooping from the bridge code to the net device code on the long run to make such a database usable for any kind of device, without needing this bridge hack. But such a migration would also need a way more invasive patchset. While Felix's idea might look a little "ugly" due it's hacky nature, I think it is also quite beautiful thanks to it's simplicity.