Le 23/09/2014 21:22, Cong Wang a écrit :
On Tue, Sep 23, 2014 at 6:20 AM, Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx> 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: <POINTOPOINT,NOARP> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
