[v4,2/4] util/qemu-sockets: Enable unix socket support on Windows

From: Bin Meng <bin.meng@windriver.com>

Support for the unix socket has existed both in BSD and Linux for the
longest time, but not on Windows. Since Windows 10 build 17063 [1],
the native support for the unix socket has come to Windows. Starting
this build, two Win32 processes can use the AF_UNIX address family
over Winsock API to communicate with each other.

[1] https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/

Signed-off-by: Xuzhou Cheng <xuzhou.cheng@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
---

Changes in v4:
- instead of introducing CONFIG_AF_UNIX, add fallback afunix.h header
  in os-win32.h, and compile the AF_UNIX stuff for all Windows hosts

Changes in v3:
- drop the run-time check afunix_available()

Changes in v2:
- move #include <afunix.h> to os-win32.h
- define WIN_BUILD_AF_UNIX only when CONFIG_WIN32

 meson.build               |  3 +++
 include/sysemu/os-win32.h | 17 +++++++++++++++++
 util/qemu-sockets.c       | 25 -------------------------
 3 files changed, 20 insertions(+), 25 deletions(-)

On Tue, Aug 2, 2022 at 12:39 PM Bin Meng <bmeng.cn@gmail.com> wrote:

> From: Bin Meng <bin.meng@windriver.com>
>
> Support for the unix socket has existed both in BSD and Linux for the
> longest time, but not on Windows. Since Windows 10 build 17063 [1],
> the native support for the unix socket has come to Windows. Starting
> this build, two Win32 processes can use the AF_UNIX address family
> over Winsock API to communicate with each other.
>
> [1] https://devblogs.microsoft.com/commandline/af_unix-comes-to-windows/
>
> 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>


> ---
>
> Changes in v4:
> - instead of introducing CONFIG_AF_UNIX, add fallback afunix.h header
>   in os-win32.h, and compile the AF_UNIX stuff for all Windows hosts
>
> Changes in v3:
> - drop the run-time check afunix_available()
>
> Changes in v2:
> - move #include <afunix.h> to os-win32.h
> - define WIN_BUILD_AF_UNIX only when CONFIG_WIN32
>
>  meson.build               |  3 +++
>  include/sysemu/os-win32.h | 17 +++++++++++++++++
>  util/qemu-sockets.c       | 25 -------------------------
>  3 files changed, 20 insertions(+), 25 deletions(-)
>
> diff --git a/meson.build b/meson.build
> index 294e9a8f32..6749223f1a 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1890,6 +1890,9 @@ config_host_data.set('HAVE_PTY_H',
> cc.has_header('pty.h'))
>  config_host_data.set('HAVE_SYS_DISK_H', cc.has_header('sys/disk.h'))
>  config_host_data.set('HAVE_SYS_IOCCOM_H', cc.has_header('sys/ioccom.h'))
>  config_host_data.set('HAVE_SYS_KCOV_H', cc.has_header('sys/kcov.h'))
> +if targetos == 'windows'
> +  config_host_data.set('HAVE_AFUNIX_H', cc.has_header('afunix.h'))
> +endif
>
>  # has_function
>  config_host_data.set('CONFIG_ACCEPT4', cc.has_function('accept4'))
> diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
> index edc3b38a57..5b38c7bd04 100644
> --- a/include/sysemu/os-win32.h
> +++ b/include/sysemu/os-win32.h
> @@ -30,6 +30,23 @@
>  #include <windows.h>
>  #include <ws2tcpip.h>
>
> +#ifdef HAVE_AFUNIX_H
> +#include <afunix.h>
> +#else
> +/*
> + * Fallback definitions of things we need in afunix.h, if not available
> from
> + * the used Windows SDK or MinGW headers.
> + */
> +#define UNIX_PATH_MAX 108
> +
> +typedef struct sockaddr_un {
> +    ADDRESS_FAMILY sun_family;
> +    char sun_path[UNIX_PATH_MAX];
> +} SOCKADDR_UN, *PSOCKADDR_UN;
> +
> +#define SIO_AF_UNIX_GETPEERPID _WSAIOR(IOC_VENDOR, 256)
> +#endif
> +
>  #ifdef __cplusplus
>  extern "C" {
>  #endif
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index 0e2298278f..83f4bd6fd2 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -880,8 +880,6 @@ static int vsock_parse(VsockSocketAddress *addr, const
> char *str,
>  }
>  #endif /* CONFIG_AF_VSOCK */
>
> -#ifndef _WIN32
> -
>  static bool saddr_is_abstract(UnixSocketAddress *saddr)
>  {
>  #ifdef CONFIG_LINUX
> @@ -1054,25 +1052,6 @@ static int unix_connect_saddr(UnixSocketAddress
> *saddr, Error **errp)
>      return -1;
>  }
>
> -#else
> -
> -static int unix_listen_saddr(UnixSocketAddress *saddr,
> -                             int num,
> -                             Error **errp)
> -{
> -    error_setg(errp, "unix sockets are not available on windows");
> -    errno = ENOTSUP;
> -    return -1;
> -}
> -
> -static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
> -{
> -    error_setg(errp, "unix sockets are not available on windows");
> -    errno = ENOTSUP;
> -    return -1;
> -}
> -#endif
> -
>  /* compatibility wrapper */
>  int unix_listen(const char *str, Error **errp)
>  {
> @@ -1335,7 +1314,6 @@ socket_sockaddr_to_address_inet(struct
> sockaddr_storage *sa,
>  }
>
>
> -#ifndef WIN32
>  static SocketAddress *
>  socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
>                                  socklen_t salen,
> @@ -1362,7 +1340,6 @@ socket_sockaddr_to_address_unix(struct
> sockaddr_storage *sa,
>      addr->u.q_unix.path = g_strndup(su->sun_path, salen);
>      return addr;
>  }
> -#endif /* WIN32 */
>
>  #ifdef CONFIG_AF_VSOCK
>  static SocketAddress *
> @@ -1394,10 +1371,8 @@ socket_sockaddr_to_address(struct sockaddr_storage
> *sa,
>      case AF_INET6:
>          return socket_sockaddr_to_address_inet(sa, salen, errp);
>
> -#ifndef WIN32
>      case AF_UNIX:
>          return socket_sockaddr_to_address_unix(sa, salen, errp);
> -#endif /* WIN32 */
>
>  #ifdef CONFIG_AF_VSOCK
>      case AF_VSOCK:
> --
> 2.34.1
>
>
>