gsasl  1.10.0
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sockets.c
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1 /* sockets.c --- wrappers for Windows socket functions
2 
3  Copyright (C) 2008-2021 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 <https://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 # if GNULIB_MSVC_NOTHROW
32 # include "msvc-nothrow.h"
33 # else
34 # include <io.h>
35 # endif
36 
37 /* Get set_winsock_errno, FD_TO_SOCKET etc. */
38 # include "w32sock.h"
39 
40 static int
41 close_fd_maybe_socket (const struct fd_hook *remaining_list,
42  gl_close_fn primary,
43  int fd)
44 {
45  /* Note about multithread-safety: There is a race condition where, between
46  our calls to closesocket() and the primary close(), some other thread
47  could make system calls that allocate precisely the same HANDLE value
48  as sock; then the primary close() would call CloseHandle() on it. */
49  SOCKET sock;
50  WSANETWORKEVENTS ev;
51 
52  /* Test whether fd refers to a socket. */
53  sock = FD_TO_SOCKET (fd);
54  ev.lNetworkEvents = 0xDEADBEEF;
55  WSAEnumNetworkEvents (sock, NULL, &ev);
56  if (ev.lNetworkEvents != 0xDEADBEEF)
57  {
58  /* fd refers to a socket. */
59  /* FIXME: other applications, like squid, use an undocumented
60  _free_osfhnd free function. But this is not enough: The 'osfile'
61  flags for fd also needs to be cleared, but it is hard to access it.
62  Instead, here we just close twice the file descriptor. */
63  if (closesocket (sock))
64  {
66  return -1;
67  }
68  else
69  {
70  /* This call frees the file descriptor and does a
71  CloseHandle ((HANDLE) _get_osfhandle (fd)), which fails. */
72  _close (fd);
73  return 0;
74  }
75  }
76  else
77  /* Some other type of file descriptor. */
78  return execute_close_hooks (remaining_list, primary, fd);
79 }
80 
81 static int
82 ioctl_fd_maybe_socket (const struct fd_hook *remaining_list,
83  gl_ioctl_fn primary,
84  int fd, int request, void *arg)
85 {
86  SOCKET sock;
87  WSANETWORKEVENTS ev;
88 
89  /* Test whether fd refers to a socket. */
90  sock = FD_TO_SOCKET (fd);
91  ev.lNetworkEvents = 0xDEADBEEF;
92  WSAEnumNetworkEvents (sock, NULL, &ev);
93  if (ev.lNetworkEvents != 0xDEADBEEF)
94  {
95  /* fd refers to a socket. */
96  if (ioctlsocket (sock, request, arg) < 0)
97  {
99  return -1;
100  }
101  else
102  return 0;
103  }
104  else
105  /* Some other type of file descriptor. */
106  return execute_ioctl_hooks (remaining_list, primary, fd, request, arg);
107 }
108 
109 static struct fd_hook fd_sockets_hook;
110 
111 static int initialized_sockets_version /* = 0 */;
112 
113 #endif /* WINDOWS_SOCKETS */
114 
115 int
116 gl_sockets_startup (int version _GL_UNUSED)
117 {
118 #if WINDOWS_SOCKETS
119  if (version > initialized_sockets_version)
120  {
121  WSADATA data;
122  int err;
123 
124  err = WSAStartup (version, &data);
125  if (err != 0)
126  return 1;
127 
128  if (data.wVersion != version)
129  {
130  WSACleanup ();
131  return 2;
132  }
133 
134  if (initialized_sockets_version == 0)
135  register_fd_hook (close_fd_maybe_socket, ioctl_fd_maybe_socket,
136  &fd_sockets_hook);
137 
138  initialized_sockets_version = version;
139  }
140 #endif
141 
142  return 0;
143 }
144 
145 int
147 {
148 #if WINDOWS_SOCKETS
149  int err;
150 
151  initialized_sockets_version = 0;
152 
153  unregister_fd_hook (&fd_sockets_hook);
154 
155  err = WSACleanup ();
156  if (err != 0)
157  return 1;
158 #endif
159 
160  return 0;
161 }
int gl_sockets_startup(int version _GL_UNUSED)
Definition: sockets.c:116
int gl_sockets_cleanup(void)
Definition: sockets.c:146
#define NULL
Definition: stddef.in.h:72
#define FD_TO_SOCKET(fd)
Definition: w32sock.h:35
static void set_winsock_errno(void)
Definition: w32sock.h:39