From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: inbound connection problems when "netlink: test for all flags of the NLM_F_DUMP composite" commit applied Date: Wed, 19 Jan 2011 21:12:27 +0100 Message-ID: <20110119201227.GF1845@del.dom.local> References: <20110118093811.GA7520@ff.dom.local> <20110118.020702.115924992.davem@davemloft.net> <20110118102437.GB7520@ff.dom.local> <4D35F8A3.1010600@netfilter.org> <20110118205507.GB4288@del.dom.local> <1295447286.2008.850.camel@mojatatu> <20110119165413.GB1845@del.dom.local> <20110119192409.GE1845@del.dom.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jamal , Pablo Neira Ayuso , David Miller , arthur.marsh@internode.on.net, eric.dumazet@gmail.com, netdev@vger.kernel.org To: Jan Engelhardt Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:35335 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750984Ab1ASUMd (ORCPT ); Wed, 19 Jan 2011 15:12:33 -0500 Received: by fxm20 with SMTP id 20so1277248fxm.19 for ; Wed, 19 Jan 2011 12:12:32 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Jan 19, 2011 at 08:47:32PM +0100, Jan Engelhardt wrote: > > On Wednesday 2011-01-19 20:24, Jarek Poplawski wrote: > >> On Wednesday 2011-01-19 17:54, Jarek Poplawski wrote: > >> > >> It looks like the authors' intentinos were to make NLM_F_MATCH not > >> stop after a single entry has been found. So that sounds like dump, > >> ok. > >> > >> But NLM_F_ROOT does not quite strike me as a dump request. What if I > >> wanted just a single item returned but still start at the root? > > > >Hmm... Does it say about starting at the root?: > > > >" NLM_F_ROOT Return the complete table instead of a > > single entry." > > I was referring to netlink.h which paraphrased that, perhaps > too short: > > #define NLM_F_ROOT 0x100 /* specify tree root */ > > But the RFC description makes for a better wording: if NLM_F_ROOT is > supposed to return "the complete table", how is it different from > NLM_F_MATCH with a wildcard criteria? > > | NLM_F_MATCH Return all entries matching criteria passed in > | message content. As I said, I'd prefer not to pretend I understand it, but, knowing names of people around this, I'm also quite sure there was a purpose. On the other hand, I'm not sure the names of flags and descriptions weren't mixed while making it general for different subsystems. BTW, don't we have in ip/tc many examples of duplicate options? Jarek P.