From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCHv4] extensions: libxt_CHECKSUM extension Date: Thu, 15 Jul 2010 17:24:31 +0200 Message-ID: <4C3F282F.3010006@trash.net> References: <20100715115229.GB6737@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100715115229.GB6737@redhat.com> Sender: netfilter-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: "Michael S. Tsirkin" Cc: "Daniel P. Berrange" , Jes Sorensen , "David S. Miller" , Jan Engelhardt , Randy Dunlap , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Am 15.07.2010 13:52, schrieb Michael S. Tsirkin: > This adds a `CHECKSUM' target, which can be used in the iptables mangle > table. > > You can use this target to compute and fill in the checksum in > a packet that lacks a checksum. This is particularly useful, > if you need to work around old applications such as dhcp clients, > that do not work well with checksum offloads, but don't want to disable > checksum offload in your device. > > The problem happens in the field with virtualized applications. > For reference, see Red Hat bz 605555, as well as > http://www.spinics.net/lists/kvm/msg37660.html > > Typical expected use (helps old dhclient binary running in a VM): > iptables -A POSTROUTING -t mangle -p udp --dport bootpc \ > -j CHECKSUM --checksum-fill Applied to iptables-next, thanks.