Re: [PATCH net-next v9 04/11] ieee802154: 6lowpan: Validate link netns in newlink() of rtnl_link_ops

Device denoted by IFLA_LINK is in link_net (IFLA_LINK_NETNSID) or source netns by design, but 6lowpan uses dev_net. Note dev->netns_local is set to true and currently link_net is implemented via a netns change. These together effectively reject IFLA_LINK_NETNSID. This patch adds a validation to ensure link_net is either NULL or identical to dev_net. Thus it would be fine to continue using dev_net when rtnetlink core begins to create devices directly in target netns. Signed-off-by: Xiao Liang <shaw.leon(a)gmail.com>