On Tue, Sep 20, 2022 at 2:23 PM Bin Meng <bmeng...@gmail.com> wrote:
> From: Xuzhou Cheng <xuzhou.ch...@windriver.com>
>
> 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.ch...@windriver.com>
> Signed-off-by: Bin Meng <bin.m...@windriver.com>
>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
>
> Changes in v2:
> - Introduce qemu_send_full() and use it
>
> include/qemu/sockets.h | 2 ++
> tests/qtest/libqmp.c | 5 +++--
> tests/qtest/libqtest.c | 4 ++--
> util/osdep.c | 33 +++++++++++++++++++++++++++++++++
> 4 files changed, 40 insertions(+), 4 deletions(-)
>
> diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
> index 038faa157f..8ff7832eba 100644
> --- a/include/qemu/sockets.h
> +++ b/include/qemu/sockets.h
> @@ -15,6 +15,8 @@ int inet_aton(const char *cp, struct in_addr *ia);
> bool fd_is_socket(int fd);
> int qemu_socket(int domain, int type, int protocol);
> int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen);
> +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);
> diff --git a/tests/qtest/libqmp.c b/tests/qtest/libqmp.c
> index ade26c15f0..2b08382e5d 100644
> --- a/tests/qtest/libqmp.c
> +++ b/tests/qtest/libqmp.c
> @@ -23,6 +23,7 @@
> #endif
>
> #include "qemu/cutils.h"
> +#include "qemu/sockets.h"
> #include "qapi/error.h"
> #include "qapi/qmp/json-parser.h"
> #include "qapi/qmp/qjson.h"
> @@ -36,7 +37,7 @@ typedef struct {
>
> static void socket_send(int fd, const char *buf, size_t size)
> {
> - size_t res = qemu_write_full(fd, buf, size);
> + ssize_t res = qemu_send_full(fd, buf, size);
>
> assert(res == size);
> }
> @@ -69,7 +70,7 @@ QDict *qmp_fd_receive(int fd)
> ssize_t len;
> char c;
>
> - len = read(fd, &c, 1);
> + len = recv(fd, &c, 1, 0);
> if (len == -1 && errno == EINTR) {
> continue;
> }
> diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
> index a0f28ddf8e..a25a8b47d0 100644
> --- a/tests/qtest/libqtest.c
> +++ b/tests/qtest/libqtest.c
> @@ -436,7 +436,7 @@ void qtest_quit(QTestState *s)
>
> static void socket_send(int fd, const char *buf, size_t size)
> {
> - size_t res = qemu_write_full(fd, buf, size);
> + ssize_t res = qemu_send_full(fd, buf, size);
>
> assert(res == size);
> }
> @@ -468,7 +468,7 @@ static GString
> *qtest_client_socket_recv_line(QTestState *s)
> ssize_t len;
> char buffer[1024];
>
> - len = read(s->fd, buffer, sizeof(buffer));
> + len = recv(s->fd, buffer, sizeof(buffer), 0);
> if (len == -1 && errno == EINTR) {
> continue;
> }
> diff --git a/util/osdep.c b/util/osdep.c
> index 60fcbbaebe..0342e754e1 100644
> --- a/util/osdep.c
> +++ b/util/osdep.c
> @@ -502,6 +502,39 @@ int qemu_accept(int s, struct sockaddr *addr,
> socklen_t *addrlen)
> return ret;
> }
>
> +/*
> + * 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)
> +{
> + ssize_t ret = 0;
> + ssize_t total = 0;
> +
> + while (count) {
> + ret = send(s, buf, count, 0);
> + if (ret < 0) {
> + if (errno == EINTR) {
> + continue;
> + }
> + break;
> + }
> +
> + count -= ret;
> + buf += ret;
> + total += ret;
> + }
> +
> + return total;
> +}
> +
> void qemu_set_hw_version(const char *version)
> {
> hw_version = version;
> --
> 2.34.1
>
>
>
--
Marc-André Lureau
