From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: [PATCH 4/7 parse attributes with nfattr_parse in nfnetlink_check_attribute Date: Tue, 6 Mar 2007 22:45:27 +0100 Message-ID: <20070306214527.GD521@postel.suug.ch> References: <45D0EE40.4050404@netfilter.org> <45D19B7A.5080305@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Netfilter Development Mailinglist , Pablo Neira Ayuso To: Patrick McHardy Return-path: Content-Disposition: inline In-Reply-To: <45D19B7A.5080305@trash.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org * Patrick McHardy 2007-02-13 12:05 > Pablo Neira Ayuso wrote: > > [PATCH] parse attributes with nfattr_parse in nfnetlink_check_attribute > > > > Use nfattr_parse to parse attributes, this patch also modifies the default > > behaviour since unknown attributes will be ignored instead of returning > > EINVAL. This ensure backward compatibility: new libraries with new > > attributes and old kernels can work. > > Currently other netlink subsystems return errors for the first level > of attributes and accept unknown attributes on deeper levels. I'm > not sure which I prefer, ignoring unknown attributes makes it > impossible for userspace to know that something isn't going to have > any effect, returning an error makes it harder to support new features. > > I know Thomas had intentions of increasing consistency in this area, > I'm just not sure in which direction :) > > Thomas, what do you think of this patch? I believe that all unknown attributes should be ignored so recent userspace code can function on older kernels. That's the way I'm working towards.