rtnetlink: pass link_net to the newlink handler
rtnetlink: pass link_net to the newlink handler

When IFLA_LINK_NETNSID is used, the netdevice should be built in this link netns
and moved at the end to another netns (pointed by the socket netns or
IFLA_NET_NS_[PID|FD]).

Existing user of the newlink handler will use the netns argument (src_net) to
find a link netdevice or to check some other information into the link netns.
For example, to find a netdevice, two information are required: an ifindex
(usually from IFLA_LINK) and a netns (this link netns).

Note: when using IFLA_LINK_NETNSID and IFLA_NET_NS_[PID|FD], a user may create a
netdevice that stands in netnsX and with its link part in netnsY, by sending a
rtnl message from netnsZ.

Signed-off-by: Nicolas Dichtel <7864bb1e0e12322ea18ea731d051b95b75140567@6wind.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs