Refactor the key layer calculation function, in particular the tunnel
key layer calculation by introducing helper functions. This is done
in preparation for supporting GRE tunnel offloads.
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NJohn Hurley <john.hurley@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>