From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] ipv6: export IP6_RT_PRIO_* to userland Date: Mon, 05 Nov 2012 12:43:05 -0500 (EST) Message-ID: <20121105.124305.1002288640313724910.davem@davemloft.net> References: <1352129298-1104-1-git-send-email-nicolas.dichtel@6wind.com> <20121105.120017.1189906314924845791.davem@davemloft.net> <5097F5DF.7040507@6wind.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: nicolas.dichtel@6wind.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:48136 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750875Ab2KERnI convert rfc822-to-8bit (ORCPT ); Mon, 5 Nov 2012 12:43:08 -0500 In-Reply-To: <5097F5DF.7040507@6wind.com> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: Nicolas Dichtel Date: Mon, 05 Nov 2012 18:22:39 +0100 > Le 05/11/2012 18:00, David Miller a =E9crit : >> From: Nicolas Dichtel >> Date: Mon, 5 Nov 2012 16:28:18 +0100 >> >>> The kernel uses some default metric when routes are managed. For >>> example, a >>> static route added with a metric set to 0 is inserted in the kernel >>> with >>> metric 1024 (IP6_RT_PRIO_USER). >>> It is useful for routing daemons to know these values, to be able t= o >>> set routes >>> without interfering with what the kernel does. >>> >>> Signed-off-by: Nicolas Dichtel >> >> But these belong in the libc headers anyways. >> >> If we haven't provided them for so long, there's no real value of >> adding them now. >> > But how can a daemon know which default values are used? If it wants > to add a route with metric =3D default + x, it should first add it wi= th > metric =3D 0, check the result and then change the metric. What do we do on the ipv4 side and how do daemons cope in that situatio= n?