On Sun, 2008-09-28 at 22:44 -0700, Eric W. Biederman wrote:

So you are looking at using NETIF_F_NETNS_LOCAL to indicate that you can't move
one of the devices?

Yes.

There is an UNREGISTER_NETDEV event and a REGISTER_NETDEV event sent when a device
is moved between namespaces.  See:  dev_change_net_namespace.

Yeah, I know.

I think you would want to look onto those and move one network device when you
move the other, without using NETIF_F_NETNS_LOCAL.

Deletion and creation we have definitely done with paired veth devices.  I haven't
looked at the migration case, but I with a little bit of guarding against recursion
it looks like it probably can be handled.  

Say trigger when your parnter device calls REGISTER_NETDEV in a different network
namespace?

Well, the's no inherent limit on the number of sibling devices, but
various conditions that the core code cannot fulfil because mac80211
also creates this master netdev (though it doesn't actually matter much
which ns it is in I guess). Right now I feel this is just too much to
ask. If anything, then I might want to allow moving a whole radio
("struct wiphy") at some point.

johannes