tests/qtest: Use send/recv for socket communication

Socket communication in the libqtest and libqmp codes uses read()
and write() which work on any file descriptor on *nix, and sockets
in *nix are an example of a file descriptor.

However sockets on Windows do not use *nix-style file descriptors,
so read() and write() cannot be used on sockets on Windows.
Switch over to use send() and recv() instead which work on both
Windows and *nix.

Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20221028045736.679903-3-bin.meng@windriver.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 036745e586..61648f3f3c 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -33,6 +33,19 @@ int qemu_socketpair(int domain, int type, int protocol, int sv[2]);
 #endif
 
 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen);
+/*
+ * A variant of send(2) which handles partial send.
+ *
+ * Return the number of bytes transferred over the socket.
+ * Set errno if fewer than `count' bytes are sent.
+ *
+ * This function don't work with non-blocking socket's.
+ * Any of the possibilities with non-blocking socket's is bad:
+ *   - return a short write (then name is wrong)
+ *   - busy wait adding (errno == EAGAIN) to the loop
+ */
+ssize_t qemu_send_full(int s, const void *buf, size_t count)
+    G_GNUC_WARN_UNUSED_RESULT;
 int socket_set_cork(int fd, int v);
 int socket_set_nodelay(int fd);
 void qemu_socket_set_block(int fd);