uspace/lib/posix/source/fcntl.c

   1 /*
   2  * Copyright (c) 2011 Petr Koupy
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup libposix
  30  * @{
  31  */
  32 /** @file File control.
  33  */
  34
  35 #define LIBPOSIX_INTERNAL
  36 #define __POSIX_DEF__(x) posix_##x
  37
  38 #include "internal/common.h"
  39 #include "posix/fcntl.h"
  40
  41 #include "libc/vfs/vfs.h"
  42 #include "posix/errno.h"
  43
  44 /**
  45  * Performs set of operations on the opened files.
  46  *
  47  * @param fd File descriptor of the opened file.
  48  * @param cmd Operation to carry out.
  49  * @return Non-negative on success. Might have special meaning corresponding
  50  *     to the requested operation.
  51  */
  52 int posix_fcntl(int fd, int cmd, ...)
  53 {
  54         int flags;
  55
  56         switch (cmd) {
  57         case F_DUPFD:
  58         case F_DUPFD_CLOEXEC:
  59                 /* VFS currently does not provide the functionality to duplicate
  60                  * opened file descriptor. */
  61                 // FIXME: implement this once dup() is available
  62                 errno = ENOTSUP;
  63                 return -1;
  64         case F_GETFD:
  65                 /* FD_CLOEXEC is not supported. There are no other flags. */
  66                 return 0;
  67         case F_SETFD:
  68                 /* FD_CLOEXEC is not supported. Ignore arguments and report success. */
  69                 return 0;
  70         case F_GETFL:
  71                 /* File status flags (i.e. O_APPEND) are currently private to the
  72                  * VFS server so it cannot be easily retrieved. */
  73                 flags = 0;
  74                 /* File access flags are currently not supported for file descriptors.
  75                  * Provide full access. */
  76                 flags |= O_RDWR;
  77                 return flags;
  78         case F_SETFL:
  79                 /* File access flags are currently not supported for file descriptors.
  80                  * Ignore arguments and report success. */
  81                 return 0;
  82         case F_GETOWN:
  83         case F_SETOWN:
  84         case F_GETLK:
  85         case F_SETLK:
  86         case F_SETLKW:
  87                 /* Signals (SIGURG) and file locks are not supported. */
  88                 errno = ENOTSUP;
  89                 return -1;
  90         default:
  91                 /* Unknown command */
  92                 errno = EINVAL;
  93                 return -1;
  94         }
  95 }
  96
  97 /**
  98  * Open, possibly create, a file.
  99  *
 100  * @param pathname Path to the file.
 101  * @param posix_flags Access mode flags.
 102  */
 103 int posix_open(const char *pathname, int posix_flags, ...)
 104 {
 105         int rc;
 106         posix_mode_t posix_mode = 0;
 107         if (posix_flags & O_CREAT) {
 108                 va_list args;
 109                 va_start(args, posix_flags);
 110                 posix_mode = va_arg(args, posix_mode_t);
 111                 va_end(args);
 112                 (void) posix_mode;
 113         }
 114
 115         if (((posix_flags & (O_RDONLY | O_WRONLY | O_RDWR)) == 0) ||
 116             ((posix_flags & (O_RDONLY | O_WRONLY)) == (O_RDONLY | O_WRONLY)) ||
 117             ((posix_flags & (O_RDONLY | O_RDWR)) == (O_RDONLY | O_RDWR)) ||
 118             ((posix_flags & (O_WRONLY | O_RDWR)) == (O_WRONLY | O_RDWR))) {
 119                 errno = EINVAL;
 120                 return -1;
 121         }
 122
 123         int flags = WALK_REGULAR;
 124         if (posix_flags & O_CREAT) {
 125                 if (posix_flags & O_EXCL)
 126                         flags |= WALK_MUST_CREATE;
 127                 else
 128                         flags |= WALK_MAY_CREATE;
 129         }
 130
 131         int mode =
 132             ((posix_flags & O_RDWR) ? MODE_READ | MODE_WRITE : 0) |
 133             ((posix_flags & O_RDONLY) ? MODE_READ : 0) |
 134             ((posix_flags & O_WRONLY) ? MODE_WRITE : 0) |
 135             ((posix_flags & O_APPEND) ? MODE_APPEND : 0);
 136
 137         int file = rcerrno(vfs_lookup, pathname, flags);
 138         if (file < 0)
 139                 return -1;
 140
 141         rc = rcerrno(vfs_open, file, mode);
 142         if (rc != EOK) {
 143                 vfs_put(file);
 144                 return -1;
 145         }
 146
 147         if (posix_flags & O_TRUNC) {
 148                 if (posix_flags & (O_RDWR | O_WRONLY)) {
 149                         rc = rcerrno(vfs_resize, file, 0);
 150                         if (rc != EOK) {
 151                                 vfs_put(file);
 152                                 return -1;
 153                         }
 154                 }
 155         }
 156
 157         return file;
 158 }
 159
 160 /** @}
 161  */
 162