Send udp data between a source and sink, optionally with udp gso.
The two processes are expected to be run on separate hosts.

A script is included that runs them together over loopback in a
single namespace for functionality testing.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>