From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [PATCH 1/2] NET: Re-add VLAN tag for devices incapable of keeping it Date: Tue, 06 Nov 2007 10:56:45 -0800 Message-ID: <4730B8ED.7020301@candelatech.com> References: <472A6089.7020104@hp.com> <18223.22291.622615.129374@zeus.sw.starentnetworks.com> <472F5A33.20906@trash.net> <20071105.151544.175839612.davem@davemloft.net> <472FB375.1020802@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Patrick McHardy , David Miller , djohnson+linux-kernel@sw.starentnetworks.com, jes@trained-monkey.org, mchan@broadcom.com, ram.vepa@neterion.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bguo@sw.starentnetworks.com To: Krzysztof Halasa Return-path: Received: from ns2.lanforge.com ([66.165.47.211]:46102 "EHLO ns2.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756639AbXKFTBg (ORCPT ); Tue, 6 Nov 2007 14:01:36 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Krzysztof Halasa wrote: > Patrick McHardy writes: > >> I think there is one more case that matters, which is briding >> from a device with VLAN stripping for a VLAN not configured >> locally. The tag will be stripped and will be lost for forwarded >> packets. > > I think we should drop such packets on RX. Anyway we shouldn't > forward them. Bridging eth0 to eth1 should not pay attention to VLAN tags at all (if the pkt comes in on VLAN 7, it should go out on VLAN 7), in my opinion. If the NIC is stripping the VLAN header, then this cannot work unless something re-builds the VLAN header. If the stripped VLAN header is placed into the skb, then any code that does need to rebuild it can do so. It may be less efficient, but users can just not use that NIC hardware for high-end solutions, and at any rate, less efficient is better than broken. Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com