From owner-freebsd-arch@FreeBSD.ORG Tue Jul 11 22:51:51 2006 Return-Path: X-Original-To: freebsd-arch@freebsd.org Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 552F316A4DF; Tue, 11 Jul 2006 22:51:51 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9B3E543D68; Tue, 11 Jul 2006 22:51:49 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 54C8046B98; Tue, 11 Jul 2006 18:51:49 -0400 (EDT) Date: Tue, 11 Jul 2006 23:51:49 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Brooks Davis In-Reply-To: <20060711162953.GC20418@odin.ac.hmc.edu> Message-ID: <20060711234931.P14749@fledge.watson.org> References: <44B15511.206@errno.com> <44B21551.5050002@freebsd.org> <20060710160441.GB31026@odin.ac.hmc.edu> <20060710202714.GC16054@heff.fud.org.nz> <20060711162953.GC20418@odin.ac.hmc.edu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Andre Oppermann , Andrew Thompson , freebsd-arch@freebsd.org Subject: Re: vlans and cloning X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Jul 2006 22:51:51 -0000 On Tue, 11 Jul 2006, Brooks Davis wrote: >>> Unless cause ifconfig to autoload all if_ modules when cloning fails, it's >>> impossiable to support this without having if_vlan loaded. That said the >>> current plan it to eliminate if_vlan and integrate vlan support directly >>> into if_ethersubr.c to allow use to correctly handle the default vlan case >>> among otherthings. >> >> Is anyone working on this? The bridge code needs access to the vlan tag to >> properly hash the address as each vlan is a seperate broadcast domain, this >> would be much easier with vlan merged to if_ethersubr.c. > > I think it ended up with Robert's name on it at the last devsummit, but he's > got a lot of higher priority stuff on his plate. It doesn't look like this > change would be all that much work. The one thing that might be worth > investigating is seeing if there's a sane way to make vlan tag parsing part > of ether_input, but keep if_vlan.c around as a module for actual support of > trunks so we get most of the architectural benefits of correctly treating > vlan tags as part of the spec, but let embedded users who don't need trunks > avoid the overhead. Yes -- the specific proposal I have made is that we combine if_vlan.c into if_ethersubr.c, as well as LLC encapsulation decapsulation. Vlans and LLC bits are all considered standard ethernet features today, and integrating the basic support (regardless of virtual interfaces) into if_ethersubr.c makes sense. It would also make the book keeping and event handling go a bit more naturally, I think. I've not had a chance to prototype this to explore what the above words actually mean, so I think some experimental prototyping is called for. It's on my todo list but something I'm likely not to get to for a few months, so if someone else wants to look into this, I think that would be great. Robert N M Watson Computer Laboratory University of Cambridge