selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV

Adds following tests:

1. AF_XDP SKB mode
   c. Socket Teardown
      Create a Tx and a Rx socket, Tx from one socket, Rx on another.
      Destroy both sockets, then repeat multiple times. Only nopoll mode
      is used

2. AF_XDP DRV/Native mode
   c. Socket Teardown
   * Only copy mode is supported because veth does not currently support
     zero-copy mode

Signed-off-by: Weqaar Janjua <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Tested-by: Yonghong Song <[email protected]>
Acked-by: Björn Töpel <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
3 files changed