It will map device ifindex to itself (but note that internally in the
kernel this is optimized into a map from ifindex to direct device
pointer), but only for xdp transmit capable devices (other devices
will not have an entry).
This will allow the use of bpf_redirect_map() from xdp tethering programs.
Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I29684e6761727d1115e9b4d75486eccbca3d5e33