bpf, selftests: Add three new sockmap tests for verdict only programs

bpf, selftests: Add three new sockmap tests for verdict only programs

Here we add three new tests for sockmap to test having a verdict program
without setting the parser program.

The first test covers the most simply case,

   sender         proxy_recv proxy_send      recv
     |                |                       |
     |              verdict -----+            |
     |                |          |            |
     +----------------+          +------------+

We load the verdict program on the proxy_recv socket without a
parser program. It then does a redirect into the send path of the
proxy_send socket using sendpage_locked().

Next we test the drop case to ensure if we kfree_skb as a result of
the verdict program everything behaves as expected.

Next we test the same configuration above, but with ktls and a
redirect into socket ingress queue. Shown here

   tls                                       tls
   sender         proxy_recv proxy_send      recv
     |                |                       |
     |              verdict ------------------+
     |                |      redirect_ingress
     +----------------+

Also to set up ping/pong test

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/160239302638.8495.17125996694402793471.stgit@john-Precision-5820-Tower