1/* sockets.c --- wrappers for Windows socket functions
2
3   Copyright (C) 2008-2014 Free Software Foundation, Inc.
4
5   This program is free software: you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18/* Written by Simon Josefsson */
19
20#include <config.h>
21
22/* Specification.  */
23#include "sockets.h"
24
25#if WINDOWS_SOCKETS
26
27/* This includes winsock2.h on MinGW. */
28# include <sys/socket.h>
29
30# include "fd-hook.h"
31# include "msvc-nothrow.h"
32
33/* Get set_winsock_errno, FD_TO_SOCKET etc. */
34# include "w32sock.h"
35
36static int
37close_fd_maybe_socket (const struct fd_hook *remaining_list,
38                       gl_close_fn primary,
39                       int fd)
40{
41  /* Note about multithread-safety: There is a race condition where, between
42     our calls to closesocket() and the primary close(), some other thread
43     could make system calls that allocate precisely the same HANDLE value
44     as sock; then the primary close() would call CloseHandle() on it.  */
45  SOCKET sock;
46  WSANETWORKEVENTS ev;
47
48  /* Test whether fd refers to a socket.  */
49  sock = FD_TO_SOCKET (fd);
50  ev.lNetworkEvents = 0xDEADBEEF;
51  WSAEnumNetworkEvents (sock, NULL, &ev);
52  if (ev.lNetworkEvents != 0xDEADBEEF)
53    {
54      /* fd refers to a socket.  */
55      /* FIXME: other applications, like squid, use an undocumented
56         _free_osfhnd free function.  But this is not enough: The 'osfile'
57         flags for fd also needs to be cleared, but it is hard to access it.
58         Instead, here we just close twice the file descriptor.  */
59      if (closesocket (sock))
60        {
61          set_winsock_errno ();
62          return -1;
63        }
64      else
65        {
66          /* This call frees the file descriptor and does a
67             CloseHandle ((HANDLE) _get_osfhandle (fd)), which fails.  */
68          _close (fd);
69          return 0;
70        }
71    }
72  else
73    /* Some other type of file descriptor.  */
74    return execute_close_hooks (remaining_list, primary, fd);
75}
76
77static int
78ioctl_fd_maybe_socket (const struct fd_hook *remaining_list,
79                       gl_ioctl_fn primary,
80                       int fd, int request, void *arg)
81{
82  SOCKET sock;
83  WSANETWORKEVENTS ev;
84
85  /* Test whether fd refers to a socket.  */
86  sock = FD_TO_SOCKET (fd);
87  ev.lNetworkEvents = 0xDEADBEEF;
88  WSAEnumNetworkEvents (sock, NULL, &ev);
89  if (ev.lNetworkEvents != 0xDEADBEEF)
90    {
91      /* fd refers to a socket.  */
92      if (ioctlsocket (sock, request, arg) < 0)
93        {
94          set_winsock_errno ();
95          return -1;
96        }
97      else
98        return 0;
99    }
100  else
101    /* Some other type of file descriptor.  */
102    return execute_ioctl_hooks (remaining_list, primary, fd, request, arg);
103}
104
105static struct fd_hook fd_sockets_hook;
106
107static int initialized_sockets_version /* = 0 */;
108
109#endif /* WINDOWS_SOCKETS */
110
111int
112gl_sockets_startup (int version _GL_UNUSED)
113{
114#if WINDOWS_SOCKETS
115  if (version > initialized_sockets_version)
116    {
117      WSADATA data;
118      int err;
119
120      err = WSAStartup (version, &data);
121      if (err != 0)
122        return 1;
123
124      if (data.wVersion < version)
125        return 2;
126
127      if (initialized_sockets_version == 0)
128        register_fd_hook (close_fd_maybe_socket, ioctl_fd_maybe_socket,
129                          &fd_sockets_hook);
130
131      initialized_sockets_version = version;
132    }
133#endif
134
135  return 0;
136}
137
138int
139gl_sockets_cleanup (void)
140{
141#if WINDOWS_SOCKETS
142  int err;
143
144  initialized_sockets_version = 0;
145
146  unregister_fd_hook (&fd_sockets_hook);
147
148  err = WSACleanup ();
149  if (err != 0)
150    return 1;
151#endif
152
153  return 0;
154}
155