selftests/tls: add a litmus test for the socket reuse through shutdown

Make sure that shutdown never works, and at the same time document how
I tested to came to the conclusion that currently reuse is not possible.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index d995e6503b1a..4c285b6e1db8 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -984,6 +984,30 @@ TEST_F(tls, shutdown_unsent)
         shutdown(self->cfd, SHUT_RDWR);
 }
 
+TEST_F(tls, shutdown_reuse)
+{
+        struct sockaddr_in addr;
+        int ret;
+
+        shutdown(self->fd, SHUT_RDWR);
+        shutdown(self->cfd, SHUT_RDWR);
+        close(self->cfd);
+
+        addr.sin_family = AF_INET;
+        addr.sin_addr.s_addr = htonl(INADDR_ANY);
+        addr.sin_port = 0;
+
+        ret = bind(self->fd, &addr, sizeof(addr));
+        EXPECT_EQ(ret, 0);
+        ret = listen(self->fd, 10);
+        EXPECT_EQ(ret, -1);
+        EXPECT_EQ(errno, EINVAL);
+
+        ret = connect(self->fd, &addr, sizeof(addr));
+        EXPECT_EQ(ret, -1);
+        EXPECT_EQ(errno, EISCONN);
+}
+
 TEST(non_established) {
         struct tls12_crypto_info_aes_gcm_256 tls12;
         struct sockaddr_in addr;