From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH 2/2 nft] scanner: fix parsing of tc handle Date: Thu, 13 Feb 2014 14:31:37 +0100 Message-ID: <20140213133137.GA9181@localhost> References: <1392291672-7885-1-git-send-email-pablo@netfilter.org> <1392291672-7885-2-git-send-email-pablo@netfilter.org> <20140213115112.GA30397@macbook.localnet> <20140213130102.GB4223@macbook.localnet> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netfilter-devel@vger.kernel.org To: Patrick McHardy Return-path: Received: from mail.us.es ([193.147.175.20]:57336 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752098AbaBMNb5 (ORCPT ); Thu, 13 Feb 2014 08:31:57 -0500 Content-Disposition: inline In-Reply-To: <20140213130102.GB4223@macbook.localnet> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Thu, Feb 13, 2014 at 01:01:03PM +0000, Patrick McHardy wrote: > On Thu, Feb 13, 2014 at 11:51:12AM +0000, Patrick McHardy wrote: > > On Thu, Feb 13, 2014 at 12:41:12PM +0100, Pablo Neira Ayuso wrote: > > > hexstring:hexstring > > > hexstring: > > > :hexstring > > > --- > > > The spaces to separate the key and the action in dictionaries is very > > > important, otherwise (with this patch) the scanner misinterprets this. > > > > > > # nft add filter input tcp dport vmap { 25:drop } > > > :1:41-43: Error: syntax error, unexpected string, expecting comma or '}' > > > add rule filter input tcp dport vmap { 25:drop } > > > ^^^ > > > I think we can just document this, I don't see any better solution for this > > > at this moment. > > > > Let me try if I can come up with something ... > > I think we might be able to do something with flex "trailing contexts", > though I didn't manage to figure it out yet. > > Generally it seems like using a ':' in maps might not be the best idea > after all, its used for too many other things already. This might be > the reason why I initially used =>, not sure anymore. > > Is there a reasonable alternative to ':' with a single character? Everything seems pretty overloaded, and I still like that python uses this for dictionaries. I think even bash and gcc provide bad error reporting if one space is missing in a for/while statement or a missing bracket is left out. Let's check if that trailing context can help us to fix it, if not, just document it. We can revisit the scanner/parser at some point. I checked antlr but I don't think their C library API is very stable / ready for third party project. But not now, we already have quite a lot of work in many other fronts :)