From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [PATCH net-next] veth: report NEWLINK event when moving the peer device in a new namespace Date: Fri, 31 Aug 2018 10:21:39 -0600 Message-ID: References: <51722660f2ef860779e227541dab77046496f135.1535712096.git.lorenzo.bianconi@redhat.com> <1321a4ad-75c5-358f-3a5d-1ec1549a9474@gmail.com> <20180831161902.GD6236@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org To: Lorenzo Bianconi Return-path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:43811 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727572AbeHaU35 (ORCPT ); Fri, 31 Aug 2018 16:29:57 -0400 Received: by mail-pg1-f196.google.com with SMTP id v66-v6so5654879pgb.10 for ; Fri, 31 Aug 2018 09:21:42 -0700 (PDT) In-Reply-To: <20180831161902.GD6236@localhost.localdomain> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 8/31/18 10:19 AM, Lorenzo Bianconi wrote: >> 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 This is in init namespace $ ip li set veth2 netns foo $ ip monitor Deleted 20: veth2@veth1: mtu 1500 qdisc noop state DOWN group default link/ether c6:d0:d6:c5:23:7d brd ff:ff:ff:ff:ff:ff new-netns foo new-ifindex 20 It shows the new namespace in the delete message.