1/* $NetBSD: flock.c,v 1.2 2017/01/28 21:31:50 christos Exp $ */ 2 3/* 4 * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska H��gskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include <config.h> 37 38#ifndef HAVE_FLOCK 39 40#include <krb5/roken.h> 41 42#define OP_MASK (LOCK_SH | LOCK_EX | LOCK_UN) 43 44 45ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL 46rk_flock(int fd, int operation) 47{ 48#if defined(HAVE_FCNTL) && defined(F_SETLK) 49 struct flock arg; 50 int code, cmd; 51 52 arg.l_whence = SEEK_SET; 53 arg.l_start = 0; 54 arg.l_len = 0; /* means to EOF */ 55 56 if (operation & LOCK_NB) 57 cmd = F_SETLK; 58 else 59 cmd = F_SETLKW; /* Blocking */ 60 61 switch (operation & OP_MASK) { 62 case LOCK_UN: 63 arg.l_type = F_UNLCK; 64 code = fcntl(fd, F_SETLK, &arg); 65 break; 66 case LOCK_SH: 67 arg.l_type = F_RDLCK; 68 code = fcntl(fd, cmd, &arg); 69 break; 70 case LOCK_EX: 71 arg.l_type = F_WRLCK; 72 code = fcntl(fd, cmd, &arg); 73 break; 74 default: 75 errno = EINVAL; 76 code = -1; 77 break; 78 } 79 return code; 80 81#elif defined(_WIN32) 82 /* Windows */ 83 84#define FLOCK_OFFSET_LOW 0 85#define FLOCK_OFFSET_HIGH 0 86#define FLOCK_LENGTH_LOW 0x00000000 87#define FLOCK_LENGTH_HIGH 0x80000000 88 89 HANDLE hFile; 90 OVERLAPPED ov; 91 BOOL rv = FALSE; 92 DWORD f = 0; 93 94 hFile = (HANDLE) _get_osfhandle(fd); 95 if (hFile == NULL || hFile == INVALID_HANDLE_VALUE) { 96 _set_errno(EBADF); 97 return -1; 98 } 99 100 ZeroMemory(&ov, sizeof(ov)); 101 ov.hEvent = NULL; 102 ov.Offset = FLOCK_OFFSET_LOW; 103 ov.OffsetHigh = FLOCK_OFFSET_HIGH; 104 105 if (operation & LOCK_NB) 106 f = LOCKFILE_FAIL_IMMEDIATELY; 107 108 switch (operation & OP_MASK) { 109 case LOCK_UN: /* Unlock */ 110 rv = UnlockFileEx(hFile, 0, 111 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH, &ov); 112 break; 113 114 case LOCK_SH: /* Shared lock */ 115 rv = LockFileEx(hFile, f, 0, 116 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH, &ov); 117 break; 118 119 case LOCK_EX: /* Exclusive lock */ 120 rv = LockFileEx(hFile, f|LOCKFILE_EXCLUSIVE_LOCK, 0, 121 FLOCK_LENGTH_LOW, FLOCK_LENGTH_HIGH, 122 &ov); 123 break; 124 125 default: 126 _set_errno(EINVAL); 127 return -1; 128 } 129 130 if (!rv) { 131 switch (GetLastError()) { 132 case ERROR_SHARING_VIOLATION: 133 case ERROR_LOCK_VIOLATION: 134 case ERROR_IO_PENDING: 135 _set_errno(EWOULDBLOCK); 136 break; 137 138 case ERROR_ACCESS_DENIED: 139 _set_errno(EACCES); 140 break; 141 142 default: 143 _set_errno(ENOLCK); 144 } 145 return -1; 146 } 147 148 return 0; 149 150#else 151 return -1; 152#endif 153} 154 155#endif 156 157