From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753536AbaIXJX1 (ORCPT ); Wed, 24 Sep 2014 05:23:27 -0400 Received: from mail-we0-f178.google.com ([74.125.82.178]:61618 "EHLO mail-we0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750856AbaIXJXW (ORCPT ); Wed, 24 Sep 2014 05:23:22 -0400 Message-ID: <54228D87.3070309@6wind.com> Date: Wed, 24 Sep 2014 11:23:19 +0200 From: Nicolas Dichtel Reply-To: nicolas.dichtel@6wind.com Organization: 6WIND User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Cong Wang CC: netdev , containers@lists.linux-foundation.org, "linux-kernel@vger.kernel.org" , linux-api@vger.kernel.org, David Miller , "Eric W. Biederman" , Stephen Hemminger , Andrew Morton , Andy Lutomirski Subject: Re: [RFC PATCH net-next v2 0/5] netns: allow to identify peer netns References: <1411478430-4989-1-git-send-email-nicolas.dichtel@6wind.com> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 23/09/2014 21:22, Cong Wang a écrit : > On Tue, Sep 23, 2014 at 6:20 AM, Nicolas Dichtel > wrote: >> >> Here is a small screenshot to show how it can be used by userland: >> $ ip netns add foo >> $ ip netns del foo >> $ ip netns >> $ touch /var/run/netns/init_net >> $ mount --bind /proc/1/ns/net /var/run/netns/init_net >> $ ip netns add foo >> $ ip netns >> foo (id: 3) >> init_net (id: 1) >> $ ip netns exec foo ip netns >> foo (id: 3) >> init_net (id: 1) >> $ ip netns exec foo ip link add ipip1 link-netnsid 1 type ipip remote 10.16.0.121 local 10.16.0.249 >> $ ip netns exec foo ip l ls ipip1 >> 6: ipip1@NONE: mtu 1480 qdisc noop state DOWN mode DEFAULT group default >> link/ipip 10.16.0.249 peer 10.16.0.121 link-netnsid 1 >> >> The parameter link-netnsid shows us where the interface sends and receives >> packets (and thus we know where encapsulated addresses are set). >> > > So ipip1 is shown in netns foo but functioning in netns init_net? Getting the > id of init_net in foo depends on your mount namespace, /var/run/netns/ may > not visible inside foo, in this case, link-netnsid is meaningless. It > is not your > fault, network namespace already heavily relies on mount namespace (sysfs > needs to be remount otherwise you can not create device with the same name.) > > On the other hand, what's the problem you are trying to solve? AFAIK, > the ifindex > issue is purely in output, IOW, the device still functions correctly > even through > its link ifindex is not correct after moving to another namespace. If > not, it is bug > we need to fix. > The problem is explained here: http://thread.gmane.org/gmane.linux.network/315933/focus=316064 and here: http://thread.gmane.org/gmane.linux.kernel.containers/28301/focus=4239 Regards, Nicolas