selftests/bpf: Add edge case tests for sockmap

Add edge case tests for sockmap.

Signed-off-by: Jiayuan Chen <[email protected]>

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

@@ -1042,6 +1042,61 @@ static void test_sockmap_vsock_unconnected(void)
 	xclose(map);
 }
 
+void *close_thread(void *arg)
+{
+	int fd = *(int *)arg;
+
+	sleep(1);
+	close(fd);
+	return NULL;
+}
+
+void test_sockmap_with_close_on_write(int family, int sotype)
+{
+	struct test_sockmap_pass_prog *skel;
+	int err, map, verdict, sent;
+	pthread_t tid;
+	int zero = 0;
+	int c = -1, p = -1;
+
+	skel = test_sockmap_pass_prog__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+
+	verdict = bpf_program__fd(skel->progs.prog_skb_verdict);
+	map = bpf_map__fd(skel->maps.sock_map_rx);
+
+	err = bpf_prog_attach(verdict, map, BPF_SK_SKB_STREAM_VERDICT, 0);
+	if (!ASSERT_OK(err, "bpf_prog_attach"))
+		goto out;
+
+	err = create_pair(family, sotype, &c, &p);
+	if (!ASSERT_OK(err, "create_pair"))
+		goto out;
+
+	err = bpf_map_update_elem(map, &zero, &p, BPF_ANY);
+	if (!ASSERT_OK(err, "bpf_map_update_elem"))
+		goto out;
+
+	err = pthread_create(&tid, 0, close_thread, &p);
+	if (!ASSERT_OK(err, "pthread_create"))
+		goto out;
+
+	sent = xsend(c, "a", 1, 0);
+	if (!ASSERT_EQ(sent, 1, "xsend"))
+		goto out;
+
+	pthread_join(tid, NULL);
+	/* p was closed in thread */
+	p = -1;
+out:
+	if (c > 0)
+		close(c);
+	if (p > 0)
+		close(p);
+	test_sockmap_pass_prog__destroy(skel);
+}
+
 void test_sockmap_basic(void)
 {
 	if (test__start_subtest("sockmap create_update_free"))
@@ -1108,4 +1163,6 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_vsock_poll();
 	if (test__start_subtest("sockmap vsock unconnected"))
 		test_sockmap_vsock_unconnected();
+	if (test__start_subtest("sockmap with unix and close"))
+		test_sockmap_with_close_on_write(AF_UNIX, SOCK_STREAM);
 }