[RFC PATCH v4 4/4] test/vsock: copy to user failure test

From: Arseniy Krasnov
Date: Thu Mar 09 2023 - 15:32:35 EST


This adds SOCK_STREAM and SOCK_SEQPACKET tests for invalid buffer case.
It tries to read data to NULL buffer (data already presents in socket's
queue), then uses valid buffer. For SOCK_STREAM second read must return
data, because skbuff is not dropped, but for SOCK_SEQPACKET skbuff will
be dropped by kernel, and 'recv()' will return EAGAIN.

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
tools/testing/vsock/vsock_test.c | 118 +++++++++++++++++++++++++++++++
1 file changed, 118 insertions(+)

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index 67e9f9df3a8c..3de10dbb50f5 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -860,6 +860,114 @@ static void test_stream_poll_rcvlowat_client(const struct test_opts *opts)
close(fd);
}

+#define INV_BUF_TEST_DATA_LEN 512
+
+static void test_inv_buf_client(const struct test_opts *opts, bool stream)
+{
+ unsigned char data[INV_BUF_TEST_DATA_LEN] = {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);
+ }
+
+ ret = recv(fd, data, sizeof(data), MSG_DONTWAIT);
+
+ if (stream) {
+ /* For SOCK_STREAM we must continue reading. */
+ if (ret != sizeof(data)) {
+ fprintf(stderr, "expected recv(2) success, got %zi\n", ret);
+ exit(EXIT_FAILURE);
+ }
+ /* Don't check errno in case of success. */
+ } else {
+ /* For SOCK_SEQPACKET socket's queue must be empty. */
+ 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[INV_BUF_TEST_DATA_LEN] = {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 +1028,16 @@ 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