[RFC PATCH v2 4/4] test/vsock: invalid buffer tests

[Arseniy Krasnov]

This adds STREAM and SEQPACKET tests for invalid buffer handling. It
tries to read data to NULL buffer (data already presents in socket's
queue), on fail kernel will free skbuff with data and next read with
MSG_DONTWAIT flag must return EAGAIN which means that skbuff was
dropped and socket's queue is empty.

Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
 tools/testing/vsock/vsock_test.c | 106 +++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index 67e9f9df3a8c..a17794a2d66c 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -860,6 +860,102 @@ static void test_stream_poll_rcvlowat_client(const struct test_opts *opts)
 	close(fd);
 }
 
+static void test_inv_buf_client(const struct test_opts *opts, bool stream)
+{
+	unsigned char data[512] = {0};
+	ssize_t ret;
+	int fd;
+
+	if (stream)
+		fd = vsock_stream_connect(opts->peer_cid, 1234);
+	else
+		fd = vsock_seqpacket_connect(opts->peer_cid, 1234);
+
+	if (fd < 0) {
+		perror("connect");
+		exit(EXIT_FAILURE);
+	}
+
+	control_expectln("SENDDONE");
+
+	/* Use invalid buffer here. */
+	ret = recv(fd, NULL, sizeof(data), 0);
+	if (ret != -1) {
+		fprintf(stderr, "expected recv(2) failure, got %zi\n", ret);
+		exit(EXIT_FAILURE);
+	}
+
+	if (errno != ENOMEM) {
+		fprintf(stderr, "unexpected recv(2) errno %d\n", errno);
+		exit(EXIT_FAILURE);
+	}
+
+	/* Now use valid buffer, but socket's queue must be empty. */
+	ret = recv(fd, data, sizeof(data), MSG_DONTWAIT);
+	if (ret != -1) {
+		fprintf(stderr, "expected recv(2) failure, got %zi\n", ret);
+		exit(EXIT_FAILURE);
+	}
+
+	if (errno != EAGAIN) {
+		fprintf(stderr, "unexpected recv(2) errno %d\n", errno);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("DONE");
+
+	close(fd);
+}
+
+static void test_inv_buf_server(const struct test_opts *opts, bool stream)
+{
+	unsigned char data[512] = {0};
+	ssize_t res;
+	int fd;
+
+	if (stream)
+		fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
+	else
+		fd = vsock_seqpacket_accept(VMADDR_CID_ANY, 1234, NULL);
+
+	if (fd < 0) {
+		perror("accept");
+		exit(EXIT_FAILURE);
+	}
+
+	res = send(fd, data, sizeof(data), 0);
+	if (res != sizeof(data)) {
+		fprintf(stderr, "unexpected send(2) result %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("SENDDONE");
+
+	control_expectln("DONE");
+
+	close(fd);
+}
+
+static void test_stream_inv_buf_client(const struct test_opts *opts)
+{
+	test_inv_buf_client(opts, true);
+}
+
+static void test_stream_inv_buf_server(const struct test_opts *opts)
+{
+	test_inv_buf_server(opts, true);
+}
+
+static void test_seqpacket_inv_buf_client(const struct test_opts *opts)
+{
+	test_inv_buf_client(opts, false);
+}
+
+static void test_seqpacket_inv_buf_server(const struct test_opts *opts)
+{
+	test_inv_buf_server(opts, false);
+}
+
 static struct test_case test_cases[] = {
 	{
 		.name = "SOCK_STREAM connection reset",
@@ -920,6 +1016,16 @@ static struct test_case test_cases[] = {
 		.run_client = test_seqpacket_bigmsg_client,
 		.run_server = test_seqpacket_bigmsg_server,
 	},
+	{
+		.name = "SOCK_STREAM test invalid buffer",
+		.run_client = test_stream_inv_buf_client,
+		.run_server = test_stream_inv_buf_server,
+	},
+	{
+		.name = "SOCK_SEQPACKET test invalid buffer",
+		.run_client = test_seqpacket_inv_buf_client,
+		.run_server = test_seqpacket_inv_buf_server,
+	},
 	{},
 };
 
-- 
2.25.1