This thing is pretty straightforward -- on netns creation
populate it with tun-s, after this collect tun files, open
and attach them with regular fd-s engine.
One tricky thing -- when populating namespace with tun links
make them all persistent and drop this flag (if required)
later, when the first alive opened appears.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The major issue with dump is -- some info id get via netlink,
some via sysfs and some (!) via opened and attached tun file.
But the latter cannot be created, if there's another one attached
(or the mq device is full with threads).
Thus we have to dump this info via existing tun file and keep one
in memory till the link dump code takes place.
Opposite situation is also possible -- we can have a persistent
unattached device. In this case we have to attach to it, dump
things and detach back.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
There will be two entities handled:
1. tun file -- an opened char device with misc major and tun minor
that can be attached to item #2
2. tun netdevice -- another type of links
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
