1 files changed, 161 insertions, 0 deletions
diff --git a/gl/lib/sockets.c b/gl/lib/sockets.c
new file mode 100644
index 0000000..ca99db8
--- /dev/null
+++ b/gl/lib/sockets.c
@@ -0,0 +1,161 @@
+/* sockets.c --- wrappers for Windows socket functions
+
+   Copyright (C) 2008-2023 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Simon Josefsson */
+
+#include <config.h>
+
+/* Specification.  */
+#include "sockets.h"
+
+#if WINDOWS_SOCKETS
+
+/* This includes winsock2.h on MinGW. */
+# include <sys/socket.h>
+
+# include "fd-hook.h"
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
+
+/* Get set_winsock_errno, FD_TO_SOCKET etc. */
+# include "w32sock.h"
+
+static int
+close_fd_maybe_socket (const struct fd_hook *remaining_list,
+                       gl_close_fn primary,
+                       int fd)
+{
+  /* Note about multithread-safety: There is a race condition where, between
+     our calls to closesocket() and the primary close(), some other thread
+     could make system calls that allocate precisely the same HANDLE value
+     as sock; then the primary close() would call CloseHandle() on it.  */
+  SOCKET sock;
+  WSANETWORKEVENTS ev;
+
+  /* Test whether fd refers to a socket.  */
+  sock = FD_TO_SOCKET (fd);
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents (sock, NULL, &ev);
+  if (ev.lNetworkEvents != 0xDEADBEEF)
+    {
+      /* fd refers to a socket.  */
+      /* FIXME: other applications, like squid, use an undocumented
+         _free_osfhnd free function.  But this is not enough: The 'osfile'
+         flags for fd also needs to be cleared, but it is hard to access it.
+         Instead, here we just close twice the file descriptor.  */
+      if (closesocket (sock))
+        {
+          set_winsock_errno ();
+          return -1;
+        }
+      else
+        {
+          /* This call frees the file descriptor and does a
+             CloseHandle ((HANDLE) _get_osfhandle (fd)), which fails.  */
+          _close (fd);
+          return 0;
+        }
+    }
+  else
+    /* Some other type of file descriptor.  */
+    return execute_close_hooks (remaining_list, primary, fd);
+}
+
+static int
+ioctl_fd_maybe_socket (const struct fd_hook *remaining_list,
+                       gl_ioctl_fn primary,
+                       int fd, int request, void *arg)
+{
+  SOCKET sock;
+  WSANETWORKEVENTS ev;
+
+  /* Test whether fd refers to a socket.  */
+  sock = FD_TO_SOCKET (fd);
+  ev.lNetworkEvents = 0xDEADBEEF;
+  WSAEnumNetworkEvents (sock, NULL, &ev);
+  if (ev.lNetworkEvents != 0xDEADBEEF)
+    {
+      /* fd refers to a socket.  */
+      if (ioctlsocket (sock, request, arg) < 0)
+        {
+          set_winsock_errno ();
+          return -1;
+        }
+      else
+        return 0;
+    }
+  else
+    /* Some other type of file descriptor.  */
+    return execute_ioctl_hooks (remaining_list, primary, fd, request, arg);
+}
+
+static struct fd_hook fd_sockets_hook;
+
+static int initialized_sockets_version /* = 0 */;
+
+#endif /* WINDOWS_SOCKETS */
+
+int
+gl_sockets_startup (_GL_UNUSED int version)
+{
+#if WINDOWS_SOCKETS
+  if (version > initialized_sockets_version)
+    {
+      WSADATA data;
+      int err;
+
+      err = WSAStartup (version, &data);
+      if (err != 0)
+        return 1;
+
+      if (data.wVersion != version)
+        {
+          WSACleanup ();
+          return 2;
+        }
+
+      if (initialized_sockets_version == 0)
+        register_fd_hook (close_fd_maybe_socket, ioctl_fd_maybe_socket,
+                          &fd_sockets_hook);
+
+      initialized_sockets_version = version;
+    }
+#endif
+
+  return 0;
+}
+
+int
+gl_sockets_cleanup (void)
+{
+#if WINDOWS_SOCKETS
+  int err;
+
+  initialized_sockets_version = 0;
+
+  unregister_fd_hook (&fd_sockets_hook);
+
+  err = WSACleanup ();
+  if (err != 0)
+    return 1;
+#endif
+
+  return 0;
+}