From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net-next] gro: Handle inline VLAN tags Date: Fri, 16 Nov 2012 17:09:19 -0800 Message-ID: <1353114559.10798.66.camel@edumazet-glaptop> References: <1353097030.2743.28.camel@bwh-desktop.uk.solarflarecom.com> <1353106865.10798.61.camel@edumazet-glaptop> <1353110430.2743.73.camel@bwh-desktop.uk.solarflarecom.com> <1353111414.10798.64.camel@edumazet-glaptop> <1353112324.2743.81.camel@bwh-desktop.uk.solarflarecom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org, linux-net-drivers@solarflare.com, Andrew Gallatin , Herbert Xu To: Ben Hutchings Return-path: Received: from mail-da0-f46.google.com ([209.85.210.46]:61271 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753647Ab2KQBJV (ORCPT ); Fri, 16 Nov 2012 20:09:21 -0500 Received: by mail-da0-f46.google.com with SMTP id n41so1363021dak.19 for ; Fri, 16 Nov 2012 17:09:21 -0800 (PST) In-Reply-To: <1353112324.2743.81.camel@bwh-desktop.uk.solarflarecom.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2012-11-17 at 00:32 +0000, Ben Hutchings wrote: > On Fri, 2012-11-16 at 16:16 -0800, Eric Dumazet wrote: > > On Sat, 2012-11-17 at 00:00 +0000, Ben Hutchings wrote: > > > > > I'm not sure what you mean by this. Is your point that the > > > copy-on-write is never needed? It is still possible for pskb_may_pull() > > > to fail. > > > > > > > A packet sniffer should have a copy of bad frames, even if dropped later > > in our stacks. > > > > GRO layer is not allowed to drop a frame, even if not 'correct'. > > What do you think the accelerated hardware does with frames that have a > truncated VLAN tag? The hardware should send us the frame, exactly like when RX checksum is wrong.