From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Bianconi Subject: Re: [PATCH net-next] veth: report NEWLINK event when moving the peer device in a new namespace Date: Fri, 31 Aug 2018 18:19:03 +0200 Message-ID: <20180831161902.GD6236@localhost.localdomain> References: <51722660f2ef860779e227541dab77046496f135.1535712096.git.lorenzo.bianconi@redhat.com> <1321a4ad-75c5-358f-3a5d-1ec1549a9474@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, netdev@vger.kernel.org To: David Ahern Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:56268 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727268AbeHaU1f (ORCPT ); Fri, 31 Aug 2018 16:27:35 -0400 Received: by mail-wm0-f66.google.com with SMTP id f21-v6so5769267wmc.5 for ; Fri, 31 Aug 2018 09:19:20 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1321a4ad-75c5-358f-3a5d-1ec1549a9474@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: > On 8/31/18 5:43 AM, Lorenzo Bianconi wrote: > > When moving a veth device to another namespace, userspace receives a > > RTM_DELLINK message indicating the device has been removed from current > > netns. However, the other peer does not receive a netlink event > > containing new values for IFLA_LINK_NETNSID and IFLA_LINK veth > > attributes. > > Fix that behaviour sending to userspace a RTM_NEWLINK message in the peer > > namespace to report new IFLA_LINK_NETNSID/IFLA_LINK values > > > > A newlink message is generated in the new namespace. What information is > missing from that message? > Hi David, let's assume we have two veth paired devices (veth0 and veth1) on inet namespace. When moving a veth1 to another namespace, userspace is notified with RTM_DELLINK event on inet namespace to indicate that veth1 has been moved to another namespace. However some userspace applications (e.g. NetworkManager), listening for events on inet namespace, are interested in veth1 ifindex in the new namespace. This patch sends a new RTM_NEWLINK event in inet namespace to provide new values for IFLA_LINK_NETNSID/IFLA_LINK Regards, Lorenzo