From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerrit Renker Subject: Re: Zero checksum in netconsole/netdump packets Date: Tue, 7 Nov 2006 10:09:02 +0000 Message-ID: <200611071009.02424@strip-the-willow> References: <454FC80B.9090001@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-6" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org Return-path: Received: from dee.erg.abdn.ac.uk ([139.133.204.82]:62659 "EHLO erg.abdn.ac.uk") by vger.kernel.org with ESMTP id S1753914AbWKGKJ3 (ORCPT ); Tue, 7 Nov 2006 05:09:29 -0500 To: Chris Lalancette In-Reply-To: <454FC80B.9090001@redhat.com> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Quoting Chris Lalancette: | Hello, | I realized that all of the packets that go from the crashing machine to the netdump server have a zero checksum. | Assuming that this is just an oversight, attached is a simple patch to compute the UDP checksum in netpoll_send_udp. | | Signed-off-by: Chris Lalancette | RFC 768 allows to not compute the checksum by leaving uh->check at 0 - hence it is not illegal. But without David's suggestion the code is not valid, since otherwise there is no way of distinguishing a computed `0' from an ignored `0' field: if ( udph->check == 0 ) udph->check = -1;