[PATCH net 2/2] selftests: tls: Cover splice on a nonblocking socket

[Jakub Kicinski <kuba@kernel.org>]

From: Chuck Lever <cel@kernel.org>

Every existing splice call in this file either passes
SPLICE_F_NONBLOCK or runs on a blocking socket, so nothing
exercises the socket's own O_NONBLOCK on the splice path. A change
that stops consulting sock->file->f_flags puts splice(2) and
sendfile(2) back to sleeping in tls_rx_rec_wait(), and the suite
still reports pass.

Splice from a nonblocking socket without SPLICE_F_NONBLOCK, first
with no record queued, which must return EAGAIN, then with a record
to deliver. A kernel that ignores the socket flag sleeps until the
harness timeout rather than returning.

Signed-off-by: Chuck Lever <cel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/net/tls.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index 9d3cd4fff062..c4203401c4bf 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -889,6 +889,37 @@ TEST_F(tls, splice_to_pipe)
 	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
 }
 
+/* The socket's O_NONBLOCK governs the record wait, as on a plain TCP
+ * socket, even without SPLICE_F_NONBLOCK.
+ */
+TEST_F(tls, splice_nonblock_socket)
+{
+	struct pollfd pfd = { .fd = self->cfd, .events = POLLIN };
+	int send_len = TLS_PAYLOAD_MAX_LEN;
+	char mem_send[TLS_PAYLOAD_MAX_LEN];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	int flags, p[2];
+
+	flags = fcntl(self->cfd, F_GETFL, 0);
+	ASSERT_GE(flags, 0);
+	ASSERT_EQ(fcntl(self->cfd, F_SETFL, flags | O_NONBLOCK), 0);
+
+	memrnd(mem_send, sizeof(mem_send));
+
+	ASSERT_GE(pipe(p), 0);
+	EXPECT_EQ(splice(self->cfd, NULL, p[1], NULL, send_len, 0), -1);
+	EXPECT_EQ(errno, EAGAIN);
+
+	/* The record may still be in flight, wait for it. A failed splice()
+	 * would leave the read() below blocking until the harness timeout.
+	 */
+	EXPECT_EQ(send(self->fd, mem_send, send_len, 0), send_len);
+	ASSERT_EQ(poll(&pfd, 1, 5000), 1);
+	ASSERT_EQ(splice(self->cfd, NULL, p[1], NULL, send_len, 0), send_len);
+	EXPECT_EQ(read(p[0], mem_recv, send_len), send_len);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
 TEST_F(tls, splice_cmsg_to_pipe)
 {
 	char *test_str = "test_read";
-- 
2.56.0