From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755264AbXKWGHw (ORCPT ); Fri, 23 Nov 2007 01:07:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752401AbXKWGHo (ORCPT ); Fri, 23 Nov 2007 01:07:44 -0500 Received: from mail1.webmaster.com ([216.152.64.169]:1379 "EHLO mail1.webmaster.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752359AbXKWGHn (ORCPT ); Fri, 23 Nov 2007 01:07:43 -0500 From: "David Schwartz" To: "Linux-Kernel@Vger. Kernel. Org" Cc: Subject: RE: [RFC/PATCH] SO_NO_CHECK for IPv6 Date: Thu, 22 Nov 2007 22:06:35 -0800 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) In-Reply-To: <20071122.171306.166854987.davem@davemloft.net> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Authenticated-Sender: joelkatz@webmaster.com X-Spam-Processed: mail1.webmaster.com, Thu, 22 Nov 2007 22:07:40 -0800 (not processed: message from trusted or authenticated source) X-MDRemoteIP: 206.171.168.138 X-Return-Path: davids@webmaster.com Reply-To: davids@webmaster.com X-MDAV-Processed: mail1.webmaster.com, Thu, 22 Nov 2007 22:07:41 -0800 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Regardless of whatever verifications your application is doing > on the data, it is not checksumming the ports and that's what > the pseudo-header is helping with. So what? We are in the case where the data has already gotten to him. If it got to him in error, he'll reject it anyway. The receive checksum check will only reject packets that he would reject anyway. That makes it needless. Of course, if the check is nearly free, there's no potential win, so no point in bothering. DS