From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincent Bernat Subject: Re: [PATCH] veth: replace iflink by a dedicated symlink in sysfs Date: Sat, 22 Aug 2015 22:51:01 +0200 Message-ID: <87si7bt5ca.fsf@zoro.exoscale.ch> References: <55D4AFCA.7080300@6wind.com> <20150820135307.3ce12f69@griffin> <55D5E4AF.7020409@6wind.com> <20150820.140734.195153496258370626.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: nicolas.dichtel@6wind.com, jbenc@redhat.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from bart.luffy.cx ([78.47.78.131]:54173 "EHLO bart.luffy.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbbHVUvE convert rfc822-to-8bit (ORCPT ); Sat, 22 Aug 2015 16:51:04 -0400 In-Reply-To: <20150820.140734.195153496258370626.davem@davemloft.net> (David Miller's message of "Thu, 20 Aug 2015 14:07:34 -0700 (PDT)") Sender: netdev-owner@vger.kernel.org List-ID: =E2=9D=A6 20 ao=C3=BBt 2015 14:07 -0700, David Miller =C2=A0: >>>> I also don't know what is the best way to handle this. veth advert= ises >>>> its peer via IFLA_LINK since 4.1, so it's too late to change it fo= r >>>> this >>>> release. >>> >>> Apparently we need to pick our poison. Either way, we break somethi= ng. >> Sure. I would prefer to have the same mechanism in all version, but = I >> can live with the other solution. >>=20 >> David, any thoughts about this? > > You can't break the 4.1 semantics, it's in a released kernel and peop= le > _ARE_ using it. I had a look at what other kind of daemons may exploit the pre-4.1 semantics (of not having an infinite loop when following iflink) and failed to find any other users than "lldpd". Other LLDP daemons (lldpad= , ladvd, openlldpd) have other ways to find the lower interface. I would also have thought that NetSNMP would use it to implement ifStackTable but it doesn't in fact implement this table. --=20 It were not best that we should all think alike; it is difference of op= inion that makes horse-races. -- Mark Twain, "Pudd'nhead Wilson's Calendar"