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/* sockets.c --- wrappers for Windows socket functions
Copyright (C) 2008-2020 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU 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 (int version _GL_UNUSED)
{
#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;
}
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