[RFC PATCH v2 4/9] vsock_test: POLLIN + SO_RCVLOWAT test

From: Arseniy Krasnov
Date: Mon Jul 25 2022 - 04:03:44 EST


This adds test to check,that when poll() returns POLLIN,POLLRDNORM bits,
next read call won't block.

Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
tools/testing/vsock/vsock_test.c | 107 +++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index dc577461afc2..920dc5d5d979 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -18,6 +18,7 @@
#include <sys/socket.h>
#include <time.h>
#include <sys/mman.h>
+#include <poll.h>

#include "timeout.h"
#include "control.h"
@@ -596,6 +597,107 @@ static void test_seqpacket_invalid_rec_buffer_server(const struct test_opts *opt
close(fd);
}

+static void test_stream_poll_rcvlowat_server(const struct test_opts *opts)
+{
+#define RCVLOWAT_BUF_SIZE 128
+ int fd;
+ int i;
+
+ fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
+ if (fd < 0) {
+ perror("accept");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Send 1 byte. */
+ send_byte(fd, 1, 0);
+
+ control_writeln("SRVSENT");
+
+ /* Wait until client is ready to receive rest of data. */
+ control_expectln("CLNSENT");
+
+ for (i = 0; i < RCVLOWAT_BUF_SIZE - 1; i++)
+ send_byte(fd, 1, 0);
+
+ /* Keep socket in active state. */
+ control_expectln("POLLDONE");
+
+ close(fd);
+}
+
+static void test_stream_poll_rcvlowat_client(const struct test_opts *opts)
+{
+ unsigned long lowat_val = RCVLOWAT_BUF_SIZE;
+ char buf[RCVLOWAT_BUF_SIZE];
+ struct pollfd fds;
+ ssize_t read_res;
+ short poll_flags;
+ int fd;
+
+ fd = vsock_stream_connect(opts->peer_cid, 1234);
+ if (fd < 0) {
+ perror("connect");
+ exit(EXIT_FAILURE);
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT,
+ &lowat_val, sizeof(lowat_val))) {
+ perror("setsockopt");
+ exit(EXIT_FAILURE);
+ }
+
+ control_expectln("SRVSENT");
+
+ /* At this point, server sent 1 byte. */
+ fds.fd = fd;
+ poll_flags = POLLIN | POLLRDNORM;
+ fds.events = poll_flags;
+
+ /* Try to wait for 1 sec. */
+ if (poll(&fds, 1, 1000) < 0) {
+ perror("poll");
+ exit(EXIT_FAILURE);
+ }
+
+ /* poll() must return nothing. */
+ if (fds.revents) {
+ fprintf(stderr, "Unexpected poll result %hx\n",
+ fds.revents);
+ exit(EXIT_FAILURE);
+ }
+
+ /* Tell server to send rest of data. */
+ control_writeln("CLNSENT");
+
+ /* Poll for data. */
+ if (poll(&fds, 1, 10000) < 0) {
+ perror("poll");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Only these two bits are expected. */
+ if (fds.revents != poll_flags) {
+ fprintf(stderr, "Unexpected poll result %hx\n",
+ fds.revents);
+ exit(EXIT_FAILURE);
+ }
+
+ /* Use MSG_DONTWAIT, if call is going to wait, EAGAIN
+ * will be returned.
+ */
+ read_res = recv(fd, buf, sizeof(buf), MSG_DONTWAIT);
+ if (read_res != RCVLOWAT_BUF_SIZE) {
+ fprintf(stderr, "Unexpected recv result %zi\n",
+ read_res);
+ exit(EXIT_FAILURE);
+ }
+
+ control_writeln("POLLDONE");
+
+ close(fd);
+}
+
static struct test_case test_cases[] = {
{
.name = "SOCK_STREAM connection reset",
@@ -646,6 +748,11 @@ static struct test_case test_cases[] = {
.run_client = test_seqpacket_invalid_rec_buffer_client,
.run_server = test_seqpacket_invalid_rec_buffer_server,
},
+ {
+ .name = "SOCK_STREAM poll() + SO_RCVLOWAT",
+ .run_client = test_stream_poll_rcvlowat_client,
+ .run_server = test_stream_poll_rcvlowat_server,
+ },
{},
};

--
2.25.1