1 /* sockets.c --- wrappers for Windows socket functions 2 3 Copyright (C) 2008-2022 Free Software Foundation, Inc. 4 5 This file is free software: you can redistribute it and/or modify 6 it under the terms of the GNU Lesser General Public License as 7 published by the Free Software Foundation; either version 2.1 of the 8 License, or (at your option) any later version. 9 10 This file 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 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser 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 (_GL_UNUSED int version) 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 } 162