From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Mason Subject: Re: [PATCH] Fix NAT for domU checksum offload Date: Fri, 14 Oct 2005 18:16:10 -0500 Message-ID: <20051014231610.GD11252@us.ibm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Pratt Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Sat, Oct 15, 2005 at 12:09:36AM +0100, Ian Pratt wrote: > > Below is a fix for the current problem of checksum offload > > not working in a NAT'ed network. The cause is the > > NAT/iptables code incorrectly modifying the TCP/UDP checksum > > (for the checksum offload case). The original code assumes a > > valid checksum, which is not the case for checksum offload > > packets (which has a complimented, partial checksum for the > > hardware to use). The fix is to compliment the new address > > and not compliment the old address (which is complimented in > > the partial checksum), and roll that with the > > ip_nat_cheat_check function. > > Thanks for looking into this -- this issue has been nagging away for a > long time. Sorry it took me so long. Hopefully, I can knock out the IPSec one faster. > > There are two "versions" of the patch below. The first > > version is a diff to show the actual changes made to the > > ip_nat_proto_udp.c and ip_nat_proto_tcp.c file (as it is > > difficult/impossible to tell from the second patch). The > > second version is the one to commit to the tree (which > > creates 2 new files in the sparse directory). > > Would we be better off committing the first patch to the patches > directory rather than adding to the sparse tree. You are right. Patch to follow. > Do you think you could send this upstream via davem? I can send this to DaveM, but it is very Xen specific. Should we wait for the big Xen/Linux merge for this, or is he currently going through the changes? > [Today has been a good day for vanquishing bugs. We're working on a few > save/restore fixes and have a list of tools issues, but 32bit isn't in > too bad shape right now.] > > Ian > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel >