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

tools/testing/selftests/bpf/test_sockmap.c

@@ -1472,12 +1472,29 @@ static void test_txmsg_skb(int cgrp, struct sockmap_options *opt)
 	txmsg_ktls_skb_drop = 0;
 	txmsg_ktls_skb_redir = 1;
 	test_exec(cgrp, opt);
+	txmsg_ktls_skb_redir = 0;
+
+	/* Tests that omit skb_parser */
+	txmsg_omit_skb_parser = 1;
+	ktls = 0;
+	txmsg_ktls_skb = 0;
+	test_exec(cgrp, opt);
+
+	txmsg_ktls_skb_drop = 1;
+	test_exec(cgrp, opt);
+	txmsg_ktls_skb_drop = 0;
+
+	txmsg_ktls_skb_redir = 1;
+	test_exec(cgrp, opt);
+
+	ktls = 1;
+	test_exec(cgrp, opt);
+	txmsg_omit_skb_parser = 0;
 
 	opt->data_test = data;
 	ktls = k;
 }
 
-
 /* Test cork with hung data. This tests poor usage patterns where
  * cork can leave data on the ring if user program is buggy and
  * doesn't flush them somehow. They do take some time however