From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerrit Renker Date: Thu, 19 Jun 2008 08:21:43 +0000 Subject: Re: QUESTION : Feature length about the non-negotiable feature Message-Id: <20080619082143.GA8680@gerrit.erg.abdn.ac.uk> List-Id: References: <48579530.4010807@cn.fujitsu.com> In-Reply-To: <48579530.4010807@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dccp@vger.kernel.org >> This has been tested, I will post the changelog for the test tree >> shortly and upload the amended tree. I would be grateful if you could >> give this a spin with your test cases. >> >> > > With the patch, it is OK for send non-negotiable features. But not valid > for check invalid value when recv. > > Thank you for testing. I don't understand your second sentence: all NN options are value-checked, i.e. if you try a Sequence Window of less than 32 or greater than 2^46-1, the connection should be reset. Likewise, Ack Ratio is checked to be in the range 0..0xFFFF. I guess you are meaning `length' rather than `value'. It is certainly possible to implement that. But it will kill any connection which has NN options with a valid value but unorthodox length. If that is what people want, then the following happens: * NN Change L arrives with valid value, but results in an empty Confirm R since the length is unorthodox with regard to RFC 4340; * receiving empty Confirm R resets the connection; * with mandatory options the Reset will happen even earlier; * a NN Confirm R with valid value (i.e. corresponding to the original value of the Change L) resets the connection as per RFC 4340, 6.6.8.