From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [PATCH 1/3] vlan: Do not support clearing VLAN_FLAG_REORDER_HDR Date: Tue, 24 May 2011 08:44:36 -0700 Message-ID: <4DDBD264.5030709@candelatech.com> References: <20110523140048.777fb378@nehalam> <20110523.172047.1438754754048434316.davem@davemloft.net> <20110524.011942.393855175233217324.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: ebiederm@xmission.com, shemminger@linux-foundation.org, nicolas.2p.debian@gmail.com, jpirko@redhat.com, xiaosuo@gmail.com, netdev@vger.kernel.org, kaber@trash.net, fubar@us.ibm.com, eric.dumazet@gmail.com, andy@greyhouse.net, jesse@nicira.com To: David Miller Return-path: Received: from mail.candelatech.com ([208.74.158.172]:52013 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755747Ab1EXPpG (ORCPT ); Tue, 24 May 2011 11:45:06 -0400 In-Reply-To: <20110524.011942.393855175233217324.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 05/23/2011 10:19 PM, David Miller wrote: > From: ebiederm@xmission.com (Eric W. Biederman) > Date: Mon, 23 May 2011 15:05:54 -0700 > >> 3) What do we do with pf_packet and vlan hardware acceleration when >> dumping not the vlan interface but the interface below the vlan >> interface? >> >> Do we provide an option to keep the vlan header? Should that option >> be on by default? >> > > The vlan_tci in the V2 pf_packet auxdata was intended for this > purpose. > > So no matter what variant of behavior is occurring, apps can properly > reconstitute the VLAN header if they inspect the vlan_tci in the > auxdata. When using pf-packet on eth0, with no VLAN devices existing, would you still be putting the VLAN tags in auxdata, or would the tags be inline in the skb? > The only thing that seems to be missing is an indication that a VLAN > tag was present at all, ie. vlan_tx_tag_present(), in this manner an > application could then differentiate between no VLAN header and a VLAN > tag of zero. For nested VLANs, the outside VLAN data is in the auxdata, and the rest is inline in the packet? Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com