[PATCH v3 2/4] util/qemu-sockets: Enable unix socket support on Windows

[Bin Meng <bmeng.cn@gmail.com>]

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 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               |  6 ++++++
 include/sysemu/os-win32.h |  4 ++++
 util/qemu-sockets.c       | 14 +++++++-------
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/meson.build b/meson.build
index 294e9a8f32..3663b925d4 100644
--- a/meson.build
+++ b/meson.build
@@ -2327,6 +2327,12 @@ have_afalg = get_option('crypto_afalg') \
   '''), error_message: 'AF_ALG requested but could not be detected').allowed()
 config_host_data.set('CONFIG_AF_ALG', have_afalg)
 
+if targetos != 'windows'
+  config_host_data.set('CONFIG_AF_UNIX', true)
+else
+  config_host_data.set('CONFIG_AF_UNIX', cc.has_header('afunix.h'))
+endif
+
 config_host_data.set('CONFIG_AF_VSOCK', cc.has_header_symbol(
   'linux/vm_sockets.h', 'AF_VSOCK',
   prefix: '#include <sys/socket.h>',
diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
index edc3b38a57..cebf260694 100644
--- a/include/sysemu/os-win32.h
+++ b/include/sysemu/os-win32.h
@@ -30,6 +30,10 @@
 #include <windows.h>
 #include <ws2tcpip.h>
 
+#ifdef CONFIG_AF_UNIX
+# include <afunix.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 0e2298278f..f9892506de 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -880,7 +880,7 @@ static int vsock_parse(VsockSocketAddress *addr, const char *str,
 }
 #endif /* CONFIG_AF_VSOCK */
 
-#ifndef _WIN32
+#ifdef CONFIG_AF_UNIX
 
 static bool saddr_is_abstract(UnixSocketAddress *saddr)
 {
@@ -1060,14 +1060,14 @@ static int unix_listen_saddr(UnixSocketAddress *saddr,
                              int num,
                              Error **errp)
 {
-    error_setg(errp, "unix sockets are not available on windows");
+    error_setg(errp, "unix sockets are not available on your host");
     errno = ENOTSUP;
     return -1;
 }
 
 static int unix_connect_saddr(UnixSocketAddress *saddr, Error **errp)
 {
-    error_setg(errp, "unix sockets are not available on windows");
+    error_setg(errp, "unix sockets are not available on your host");
     errno = ENOTSUP;
     return -1;
 }
@@ -1335,7 +1335,7 @@ socket_sockaddr_to_address_inet(struct sockaddr_storage *sa,
 }
 
 
-#ifndef WIN32
+#ifdef CONFIG_AF_UNIX
 static SocketAddress *
 socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
                                 socklen_t salen,
@@ -1362,7 +1362,7 @@ socket_sockaddr_to_address_unix(struct sockaddr_storage *sa,
     addr->u.q_unix.path = g_strndup(su->sun_path, salen);
     return addr;
 }
-#endif /* WIN32 */
+#endif /* CONFIG_AF_UNIX */
 
 #ifdef CONFIG_AF_VSOCK
 static SocketAddress *
@@ -1394,10 +1394,10 @@ socket_sockaddr_to_address(struct sockaddr_storage *sa,
     case AF_INET6:
         return socket_sockaddr_to_address_inet(sa, salen, errp);
 
-#ifndef WIN32
+#ifdef CONFIG_AF_UNIX
     case AF_UNIX:
         return socket_sockaddr_to_address_unix(sa, salen, errp);
-#endif /* WIN32 */
+#endif
 
 #ifdef CONFIG_AF_VSOCK
     case AF_VSOCK:
-- 
2.34.1