From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Duyck Subject: Re: [PATCH v3] net: Do not include padding in TCP GRO checksum Date: Sun, 17 Nov 2013 10:24:36 -0800 Message-ID: <528909E4.1000100@gmail.com> References: <20131115225856.6988.69733.stgit@ahduyck-fpga.jf.intel.com> <20131116004738.GA1491@gondor.apana.org.au> <20131116015301.GA1999@gondor.apana.org.au> <5286F018.8060801@gmail.com> <20131116064611.GA12146@gondor.apana.org.au> <5287A52A.2060802@gmail.com> <20131117031710.GA18254@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Alexander Duyck , davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com To: Herbert Xu Return-path: Received: from mail-pb0-f41.google.com ([209.85.160.41]:46087 "EHLO mail-pb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751864Ab3KQSYl (ORCPT ); Sun, 17 Nov 2013 13:24:41 -0500 Received: by mail-pb0-f41.google.com with SMTP id jt11so5748198pbb.0 for ; Sun, 17 Nov 2013 10:24:41 -0800 (PST) In-Reply-To: <20131117031710.GA18254@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: On 11/16/2013 07:17 PM, Herbert Xu wrote: > On Sat, Nov 16, 2013 at 09:02:34AM -0800, Alexander Duyck wrote: >> That being the case though, why don't we set the flush flag on detecting >> a bad checksum and hand it off to tcp_gro_receive instead of returning >> NULL? It seems like it would be in our interest to flush the flow and >> then report the bad checksum instead of keeping the flow and handing off >> the bad checksum to the stack. > Because if the TCP checksum is wrong then it may belong to a > different flow. > > Cheers, It seems like it would be much more likely that a checksum error occuring with a padded frame would corrupt the flow identifying data then one that isn't padded. I suppose it doesn't really matter though since checksum errors are probably not going to be all that common of a case to deal with anyway. Thanks, Alex