glib/win32: introduce private g_win32_handle_is_socket()

Used in following commits, including in some GIO experiments.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

4 files changed, 24 insertions, 0 deletions

diff --git a/glib/glib-init.h b/glib/glib-init.h
index b01d256b9..73e186199 100644
--- a/glib/glib-init.h
+++ b/glib/glib-init.h
@@ -44,6 +44,7 @@ gboolean _g_win32_call_rtl_version (OSVERSIONINFOEXW *info);
 extern HMODULE glib_dll;
 gchar *g_win32_find_helper_executable_path (const gchar *process_name, void *dll_handle);
 int g_win32_reopen_noninherited (int fd, int mode, GError **err);
+gboolean g_win32_handle_is_socket (void *h);
 
 #endif
 
diff --git a/glib/glib-private.c b/glib/glib-private.c
index 357a43a30..321efc1d6 100644
--- a/glib/glib-private.c
+++ b/glib/glib-private.c
@@ -56,6 +56,7 @@ glib__private__ (void)
     g_win32_fstat,
     g_win32_find_helper_executable_path,
     g_win32_reopen_noninherited,
+    g_win32_handle_is_socket,
 #endif
   };
 
diff --git a/glib/glib-private.h b/glib/glib-private.h
index 787f8f1fa..39b7c0a8e 100644
--- a/glib/glib-private.h
+++ b/glib/glib-private.h
@@ -175,6 +175,9 @@ typedef struct {
   int                   (* g_win32_reopen_noninherited) (int      fd,
                                                          int      mode,
                                                          GError **err);
+
+  gboolean              (* g_win32_handle_is_socket)    (void *handle);
+
 #endif
 
 
diff --git a/glib/gwin32.c b/glib/gwin32.c
index a4ed386ba..c0e1d7f3f 100644
--- a/glib/gwin32.c
+++ b/glib/gwin32.c
@@ -1451,6 +1451,25 @@ g_win32_find_helper_executable_path (const gchar *executable_name, void *dll_han
 }
 
 /*
+ * g_win32_handle_is_socket:
+ * @h: a win32 HANDLE
+ *
+ * Returns: %TRUE if the handle is a `SOCKET`.
+ */
+gboolean
+g_win32_handle_is_socket (HANDLE h)
+{
+  int option = 0;
+  int optlen = sizeof (option);
+
+  /* according to: https://stackoverflow.com/a/50981652/1277510, this is reasonable */
+  if (getsockopt ((SOCKET) h, SOL_SOCKET, SO_DEBUG, (char *) &option, &optlen) == SOCKET_ERROR)
+    return FALSE;
+
+  return TRUE;
+}
+
+/*
  * g_win32_reopen_noninherited:
  * @fd: (transfer full): A file descriptor
  * @mode: _open_osfhandle flags