From mboxrd@z Thu Jan 1 00:00:00 1970 From: Volker Poplawski Subject: Re: libnl: Unmatched NL_ACT_DEL and NL_ACT_CHANGE Date: Tue, 7 Jul 2009 11:01:24 +0200 Message-ID: <200907071101.24738.volker@openbios.org> References: <200907051144.51967.volker@openbios.org> <200907061417.41282.volker@openbios.org> <4A52DD46.5090501@snapgear.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit To: Philip Craig , netfilter-devel@vger.kernel.org Return-path: Received: from khepri.openbios.org ([80.190.231.112]:9777 "EHLO khepri.openbios.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754760AbZGGJBN (ORCPT ); Tue, 7 Jul 2009 05:01:13 -0400 In-Reply-To: <4A52DD46.5090501@snapgear.com> Content-Disposition: inline Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Tuesday 07 July 2009 07:29:42 you wrote: > Volker Poplawski wrote: > > On Monday 06 July 2009 13:29:40 you wrote: > >> Volker Poplawski wrote: > >>> Hi all. > >>> > >>> Could s.o. please have a look at my (short) code at > >>> http://pastie.org/534637 > >>> > >>> (maybe compile it with g++ -Wall test.c -o test -I ... -L ... -lnl > >>> -lnl-genl - lnl-nf -lnl-route) > >>> > >>> What the code does is to listen to changes in the ct-table using libnl. > >>> It keeps score of reported ctId in a lookup table. > >>> > >>> Problem is: I'm getting a lot of NL_ACT_CHANGE & NL_ACT_DEL without > >>> having seen a matching NL_ACT_NEW. (Also there seems to be no initial > >>> cache fill) > >>> > >>> kernel 2.6.27 (opensuse 11.1), libnl 2.0 (git master) > >> > >> I think I know whats happening - the ct objects don't define the > >> attribute(s) distinguishing different entries, so cache_include() > >> doesn't recognize them as new. > >> > >> Does this patch make any difference? > > Yes that improves it. We probably want to change libnl so that we > can specify a set of optional attributes to compare, so that > nl_object_identical does something like this: > > if ((a->ce_mask & req_attrs) != req_attrs || > (b->ce_mask & req_attrs) != req_attrs) > return 0; > > if ((a->ce_mask & opt_attrs) != (b->ce_mask & opt_attrs)) > return 0; > ... > return !(ops->oo_compare(a, b, (req_attrs | a->ce_mask & opt_attrs), 0)); > > > This would let it work on older kernels that don't include the id too. > > > Yes it does, NL_ACT_DEL , _CHANGE and _DEL are now matching -- for > > ct-entries created after i made my call to nl_cache_mngr_add( ... > > "netfilter/ct"... ) > > > > However, i still don't get a NL_ACT_DEL on already existing connections > > (CHANGE and DEL though) > > I assume you meant you don't get NL_ACT_NEW events for existing > connections. That's just how libnl works in general. You can use > nl_cache_get_first/nl_cache_get_next to populate your hashtable > before you start polling. Uups, typo. nl_cache_get_first/nl_cache_get_next did the trick. Thanx