Add detection for kernel version, and adapt the BPF program based on
kernel support. This way, users will get the best possible performance
from the BPF program.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NMarek Majtyka  <alardam@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: NMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210122105351.11751-4-bjorn.topel@gmail.com