Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752922AbXKXGBH (ORCPT ); Sat, 24 Nov 2007 01:01:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751269AbXKXGAx (ORCPT ); Sat, 24 Nov 2007 01:00:53 -0500 Received: from rhun.apana.org.au ([64.62.148.172]:3120 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751112AbXKXGAw (ORCPT ); Sat, 24 Nov 2007 01:00:52 -0500 From: Herbert Xu To: davids@webmaster.com Subject: Re: [RFC/PATCH] SO_NO_CHECK for IPv6 Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Organization: Core In-Reply-To: X-Newsgroups: apana.lists.os.linux.kernel,apana.lists.os.linux.netdev User-Agent: tin/1.7.4-20040225 ("Benbecula") (UNIX) (Linux/2.6.17-rc4 (i686)) Message-Id: Date: Sat, 24 Nov 2007 14:00:41 +0800 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1150 Lines: 28 David Schwartz wrote: > >> 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. What if it goes to the wrong recipient who doesn't have the upper- level checksums? This is the whole point, IPv6 unlike IPv4 does not have IP header checksums so the high-level needs to protect it by checksumming the pseudo-header. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/