From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dichtel Subject: Re: [PATCH RFC] ipv6: fix route selection if kernel is not compiled with CONFIG_IPV6_ROUTER_PREF Date: Fri, 12 Jul 2013 14:04:45 +0200 Message-ID: <51DFF0DD.5050601@6wind.com> References: <51DD2959.9060206@6wind.com> <20130710105316.GA5735@order.stressinduktion.org> <51DD521F.1000905@6wind.com> <20130710132122.GD15411@order.stressinduktion.org> <51DD6B72.1050700@6wind.com> <20130710212149.GA26122@order.stressinduktion.org> <51DE671F.5050706@6wind.com> <20130711102441.GC5207@order.stressinduktion.org> <20130711144623.GA5707@order.stressinduktion.org> <51DEC7E6.8000500@6wind.com> <20130712085113.GI12611@order.stressinduktion.org> Reply-To: nicolas.dichtel@6wind.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org, yoshfuji@linux-ipv6.org, petrus.lt@gmail.com, davem@davemloft.net To: hannes@stressinduktion.org Return-path: Received: from mail-we0-f171.google.com ([74.125.82.171]:63236 "EHLO mail-we0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932887Ab3GLMEt (ORCPT ); Fri, 12 Jul 2013 08:04:49 -0400 Received: by mail-we0-f171.google.com with SMTP id m46so7982614wev.16 for ; Fri, 12 Jul 2013 05:04:48 -0700 (PDT) In-Reply-To: <20130712085113.GI12611@order.stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: Le 12/07/2013 10:51, Hannes Frederic Sowa a =C3=A9crit : > Hello Nicolas, > > On Thu, Jul 11, 2013 at 04:57:42PM +0200, Nicolas Dichtel wrote: >> Le 11/07/2013 16:46, Hannes Frederic Sowa a =C3=A9crit : >>> On Thu, Jul 11, 2013 at 12:24:41PM +0200, Hannes Frederic Sowa wrot= e: >>>> I fear, I'll need to do a bit more research. >>> >>> My proposal is to take my patch and check for RTF_ADDRCONF plus >>> RTF_DYNAMIC, >>> too. The RTF_DYNAMIC check would prevent routes created from icmpv6 >>> redirects >>> entering an ecmp route set. >>> >>> Do you agree? >> Yes. > > There is still some window where things go wrong now, I fear. If we h= ave ecmp > routes active and we update the pmtu of that rt6_info, we might end u= p with a > route in the ecmp set, which might not get recountet if another ecmp = route > joins the set. I will have to think how to deal with this. Do you hav= e an > idea? It's possible to add a glue to check this counter when we play with the= se flags,=20 but it's ugly. Maybe the check against RTF_EXPIRES is fundamentally wrong. Checking=20 RTF_ADDRCONF|RTF_DYNAMIC should be enough, what do you think? In another hand, we can discuss about the initial assumption, that was = "only=20 static routes are part of ECMP routes". I'm thinking of what are the co= nsequence=20 if we accept to accept all routes, without checking any flags. Regards, Nicolas