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