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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 | { | |
65 | set_winsock_errno (); | |
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 | { | |
98 | set_winsock_errno (); | |
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 | |
146 | gl_sockets_cleanup (void) | |
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 | } |