This adds test which checks, that updating SO_RCVLOWAT value also sends
credit update message. Otherwise mutual hungup may happen when receiver
didn't send credit update and then calls 'poll()' with non default
SO_RCVLOWAT value (e.g. waiting enough bytes to read), while sender
waits for free space at receiver's side.
Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
---
tools/testing/vsock/vsock_test.c | 131 +++++++++++++++++++++++++++++++
1 file changed, 131 insertions(+)
diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index c1f7bc9abd22..c71b3875fd16 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -1180,6 +1180,132 @@ static void test_stream_shutrd_server(const struct test_opts *opts)
close(fd);
}
+#define RCVLOWAT_CREDIT_UPD_BUF_SIZE (1024 * 128)
+#define VIRTIO_VSOCK_MAX_PKT_BUF_SIZE (1024 * 64)
+
+static void test_stream_rcvlowat_def_cred_upd_client(const struct test_opts *opts)
+{
+ size_t buf_size;
+ void *buf;
+ int fd;
+
+ fd = vsock_stream_connect(opts->peer_cid, 1234);
+ if (fd < 0) {
+ perror("connect");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Send 1 byte more than peer's buffer size. */
+ buf_size = RCVLOWAT_CREDIT_UPD_BUF_SIZE + 1;
+
+ buf = malloc(buf_size);
+ if (!buf) {
+ perror("malloc");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Wait until peer sets needed buffer size. */
+ control_expectln("SRVREADY");
+
+ if (send(fd, buf, buf_size, 0) != buf_size) {
+ perror("send failed");
+ exit(EXIT_FAILURE);
+ }
+
+ free(buf);
+ close(fd);
+}
+
+static void test_stream_rcvlowat_def_cred_upd_server(const struct test_opts *opts)
+{
+ size_t recv_buf_size;
+ struct pollfd fds;
+ size_t buf_size;
+ void *buf;
+ int fd;
+
+ fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
+ if (fd < 0) {
+ perror("accept");
+ exit(EXIT_FAILURE);
+ }
+
+ buf_size = RCVLOWAT_CREDIT_UPD_BUF_SIZE;
+
+ if (setsockopt(fd, AF_VSOCK, SO_VM_SOCKETS_BUFFER_SIZE,
+ &buf_size, sizeof(buf_size))) {
+ perror("setsockopt(SO_VM_SOCKETS_BUFFER_SIZE)");
+ exit(EXIT_FAILURE);
+ }
+
+ buf = malloc(buf_size);
+ if (!buf) {
+ perror("malloc");
+ exit(EXIT_FAILURE);
+ }
+
+ control_writeln("SRVREADY");
+
+ /* Wait until there will be 128KB of data in rx queue. */
+ while (1) {
+ ssize_t res;
+
+ res = recv(fd, buf, buf_size, MSG_PEEK);
+ if (res == buf_size)
+ break;
+
+ if (res <= 0) {
+ fprintf(stderr, "unexpected 'recv()' return: %zi\n", res);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /* There is 128KB of data in the socket's rx queue,
+ * dequeue first 64KB, credit update is not sent.
+ */
+ recv_buf_size = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
+ recv_buf(fd, buf, recv_buf_size, 0, recv_buf_size);
+ recv_buf_size++;
+
+ /* Updating SO_RCVLOWAT will send credit update. */
+ if (setsockopt(fd, SOL_SOCKET, SO_RCVLOWAT,
+ &recv_buf_size, sizeof(recv_buf_size))) {
+ perror("setsockopt(SO_RCVLOWAT)");
+ exit(EXIT_FAILURE);
+ }
+
+ memset(&fds, 0, sizeof(fds));
+ fds.fd = fd;
+ fds.events = POLLIN | POLLRDNORM | POLLERR |
+ POLLRDHUP | POLLHUP;
+
+ /* This 'poll()' will return once we receive last byte
+ * sent by client.
+ */
+ if (poll(&fds, 1, -1) < 0) {
+ perror("poll");
+ exit(EXIT_FAILURE);
+ }
+
+ if (fds.revents & POLLERR) {
+ fprintf(stderr, "'poll()' error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (fds.revents & (POLLIN | POLLRDNORM)) {
+ recv_buf(fd, buf, recv_buf_size, 0, recv_buf_size);
+ } else {
+ /* These flags must be set, as there is at
+ * least 64KB of data ready to read.
+ */
+ fprintf(stderr, "POLLIN | POLLRDNORM expected\n");
+ exit(EXIT_FAILURE);
+ }
+
+ free(buf);
+ close(fd);
+}
+
static struct test_case test_cases[] = {
{
.name = "SOCK_STREAM connection reset",
@@ -1285,6 +1411,11 @@ static struct test_case test_cases[] = {
.run_client = test_stream_msgzcopy_empty_errq_client,
.run_server = test_stream_msgzcopy_empty_errq_server,
},
+ {
+ .name = "SOCK_STREAM virtio SO_RCVLOWAT + deferred cred update",
+ .run_client = test_stream_rcvlowat_def_cred_upd_client,
+ .run_server = test_stream_rcvlowat_def_cred_upd_server,
+ },
{},
};
--
2.25.1
