From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nivedita Singhvi Subject: Re: [PATCH] IPv6: only modify checksum for UDP Date: Fri, 10 Nov 2006 15:17:06 -0800 Message-ID: <45550872.6050900@us.ibm.com> References: <45536622.90708@hp.com> <20061109.151402.15590179.davem@davemloft.net> <4554A7CD.6040907@hp.com> <20061110.145507.112290147.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: brian.haley@hp.com, viro@ftp.linux.org.uk, netdev@vger.kernel.org Return-path: Received: from e6.ny.us.ibm.com ([32.97.182.146]:50125 "EHLO e6.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1424454AbWKJXRP (ORCPT ); Fri, 10 Nov 2006 18:17:15 -0500 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e6.ny.us.ibm.com (8.13.8/8.12.11) with ESMTP id kAANHXaM017966 for ; Fri, 10 Nov 2006 18:17:33 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay04.pok.ibm.com (8.13.6/8.13.6/NCO v8.1.1) with ESMTP id kAANHDae232768 for ; Fri, 10 Nov 2006 18:17:13 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id kAANHD11012199 for ; Fri, 10 Nov 2006 18:17:13 -0500 To: David Miller In-Reply-To: <20061110.145507.112290147.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org David Miller wrote: > From: Brian Haley > Date: Fri, 10 Nov 2006 11:24:45 -0500 > >> Only change upper-layer checksum from 0 to 0xFFFF for UDP (as RFC 768 >> states), not for others as RFC 4443 doesn't require it. >> >> Signed-off-by: Brian Haley > > Applied, thanks Brian. Brian Haley wrote: > Al Viro wrote: >> Could you fscking read what you've replied to? Your -=1 will turn 0 >> into 0xffff instead of correct 0xfffe. IOW, it's broken in 1:65536 >> cases. > > I looked again at your previous email: > >> Note that even on little-endian you want >> 3 -> 2 >> 2 -> 1 >> 1 -> 0xffff >> 0 -> 0xfffe > > That doesn't look right to me, but I'll take your word that there's one > edge case out there I don't see (even though this worked on Alpha). > Forget about the patch then. Er, given all of the above, Brian, could you share your test cases and/or other/any information on testing this? thanks, Nivedita