From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756393AbZBSJMj (ORCPT ); Thu, 19 Feb 2009 04:12:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753710AbZBSJMW (ORCPT ); Thu, 19 Feb 2009 04:12:22 -0500 Received: from vervifontaine.sonytel.be ([80.88.33.193]:37912 "EHLO vervifontaine.sonycom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752214AbZBSJMU (ORCPT ); Thu, 19 Feb 2009 04:12:20 -0500 Date: Thu, 19 Feb 2009 10:12:18 +0100 (CET) From: Geert Uytterhoeven To: Herbert Xu cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] crypto: compress - Add pcomp interface In-Reply-To: <20090219040847.GA973@gondor.apana.org.au> Message-ID: References: <1231862386-11128-1-git-send-email-Geert.Uytterhoeven@sonycom.com> <1231862386-11128-2-git-send-email-Geert.Uytterhoeven@sonycom.com> <20090114031613.GA7429@gondor.apana.org.au> <20090115030526.GA27726@gondor.apana.org.au> <20090210061822.GA19774@gondor.apana.org.au> <20090219040847.GA973@gondor.apana.org.au> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Feb 2009, Herbert Xu wrote: > On Thu, Feb 12, 2009 at 04:19:40PM +0100, Geert Uytterhoeven wrote: > > On Tue, 10 Feb 2009, Herbert Xu wrote: > > > On Thu, Feb 05, 2009 at 05:24:51PM +0100, Geert Uytterhoeven wrote: > > > > > Well with the netlink parameters these can have variable lengths > > > > > depending on how many parameters the user supplies. > > > > > > > > How can this be exported to userspace? > > > > How does this variable length parameter passing work? Do you have an example? > > > > > > See how we use it for rtnetlink, e.g., in net/ipv4/ip_gre.c. > > > > > > > Nothing in crypto/ seems to already use nla_*? > > > > > > Well we don't have a user-space API yet :) But checkout the > > > discussions on this list. > > > > I'm sorry, but this is a totally separate change, so I'm not going to do it > > right now. > > Sorry but I disagree. We're working on the user-space API right > now and having to redo the compression parameters API later because > we didn't take take user-space into account is just not acceptable. OK, I'll give it a try... > In any case, the nla stuff is not as hard is it looks. It's > going to add tens of lines to the setup code and that's it. > > In order to get started, all you need to do is call nla_parse. > You don't even need a policy for the simple attributes. > > Please let me know if you need more help in getting nla_parse > going. IIUC, my setup() routines should decode the parameters using nla_parse()? And the caller of a setup() routine should encode the data. But how? All the nla_put*() routines seem to be targeted at skb's. The only place where nla_parse() is called with a void */length pair is net/sched/em_meta.c:em_meta_change(). But I can find no place where the actual TCA_EM_META_* fields are encoded. Can you please explain? Thanks! With kind regards, Geert Uytterhoeven Software Architect Sony Techsoft Centre Europe The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: Geert.Uytterhoeven@sonycom.com Internet: http://www.sony-europe.com/ A division of Sony Europe (Belgium) N.V. VAT BE 0413.825.160 · RPR Brussels Fortis · BIC GEBABEBB · IBAN BE41293037680010