crypto/external/bsd/heimdal/dist/lib/roken/flock.c

   1 /*      $NetBSD: flock.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $      */
   2
   3 /*
   4  * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
   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
  45 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
  46 rk_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