From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760146Ab3BHOQt (ORCPT ); Fri, 8 Feb 2013 09:16:49 -0500 Received: from zproxy210.enst-bretagne.fr ([192.108.117.8]:51748 "EHLO zproxy210.enst-bretagne.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758547Ab3BHOQs convert rfc822-to-8bit (ORCPT ); Fri, 8 Feb 2013 09:16:48 -0500 Content-Type: text/plain; charset=iso-8859-1 Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: Re: [RFC PATCH] xfrm: fix handling of XFRM policies mark and mask. From: Emmanuel Thierry In-Reply-To: <20130207125437.GC17794@secunet.com> Date: Fri, 8 Feb 2013 15:16:45 +0100 Cc: jamal , Romain KUNTZ , "netdev@vger.kernel.org" , "davem@davemloft.net" , herbert@gondor.hengli.com.au, "linux-kernel@vger.kernel.org" , Jamal Hadi Salim Content-Transfer-Encoding: 8BIT Message-Id: <1854603B-3AD1-4245-A8BA-53D841BCEA63@telecom-bretagne.eu> References: <9E57ADA1-5770-47A8-8EBF-7FC262EEF1C7@ipflavors.com> <20130205081232.GF23291@secunet.com> <51125744.3030905@gmail.com> <20130207104908.GA17794@secunet.com> <2BEAF521-7218-415B-98ED-EC0812903479@telecom-bretagne.eu> <20130207125437.GC17794@secunet.com> To: Steffen Klassert X-Mailer: Apple Mail (2.1499) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Le 7 févr. 2013 à 13:54, Steffen Klassert a écrit : > On Thu, Feb 07, 2013 at 12:08:22PM +0100, Emmanuel Thierry wrote: >> >> This is a nice idea, however you keep the insertion asymmetric. The usage of xfrm marks in non-conflicting cases will be made possible, but it stays disturbing for a user as the initial example will still have the same behavior: >> * Inserting the marked one then the unmarked will succeed >> * Inserting the unmarked then the marked one will fail >> This gives to the user the feeling of an indeterministic behavior of the xfrm module. > > This was intended. Inserting the marked one then the unmarked > is a working scenario. Some users might rely on it, so we can't > change this as you proposed. > > On the other hand, inserting the unmarked one then the marked > might result in a wrong policy lookup, so we can't allow this. > The only possibility we have, is inserting with different > priorites and that's what I'm proposing. > > I fear we have to live with that asymmetric behaviour if > both policies have the same priority. > Ok, actually i understand the concern of backward compatibility you expose. It is true that users might be disturbed if we change such a behavior they would rely on. Anyway, i'm ok with your patch. Best regards Emmanuel Thierry