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/******************************************************************************

*                                                                             *

* License Agreement                                                           *

*                                                                             *

* Copyright (c) 2004 Altera Corporation, San Jose, California, USA.           *

* All rights reserved.                                                        *

*                                                                             *

* Permission is hereby granted, free of charge, to any person obtaining a     *

* copy of this software and associated documentation files (the "Software"),  *

* to deal in the Software without restriction, including without limitation   *

* the rights to use, copy, modify, merge, publish, distribute, sublicense,    *

* and/or sell copies of the Software, and to permit persons to whom the       *

* Software is furnished to do so, subject to the following conditions:        *

*                                                                             *

* The above copyright notice and this permission notice shall be included in  *

* all copies or substantial portions of the Software.                         *

*                                                                             *

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  *

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    *

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *

* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER      *

* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING     *

* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER         *

* DEALINGS IN THE SOFTWARE.                                                   *

*                                                                             *

* This agreement shall be governed in all respects by the laws of the State   *

* of California and by the laws of the United States of America.              *

*                                                                             *

* Altera does not recommend, suggest or require that this reference design    *

* file be used in conjunction or combination with any other product.          *

******************************************************************************/

#include <unistd.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdarg.h>

#include "sys/alt_errno.h"

#include "priv/alt_file.h"

#include "alt_types.h"

#include "os/alt_syscall.h"

#define ALT_FCNTL_FLAGS_MASK ((alt_u32) (O_APPEND | O_NONBLOCK))

/*

 * fcntl() is a limited implementation of the standard fcntl() system call.

 * It can be used to change the state of the flags associated with an open

 * file descriptor. Normally these flags are set during the call to

 * open(). It is anticipated that the main use of this function will be to

 * change the state of a device from blocking to non-blocking (where this is

 * supported).

 *

 * The input argument "fd" is the file descriptor to be manipulated. "cmd"

 * is the command to execute. This can be either F_GETFL (return the

 * current value of the flags) or F_SETFL (set the value of the flags).

 *

 * If "cmd" is F_SETFL then the argument "arg" is the new value of flags,

 * otherwise "arg" is ignored. Only the flags: O_APPEND and O_NONBLOCK

 * can be updated by a call to fcntl(). All other flags remain

 * unchanged.

 *

 * ALT_FCNTL is mapped onto the fcntl() system call in alt_syscall.h

 */

int ALT_FCNTL (int file, int cmd, ...)

{

  alt_fd*  fd;

  long     flags;

  va_list  argp;

  /*

   * A common error case is that when the file descriptor was created, the call

   * to open() failed resulting in a negative file descriptor. This is trapped

   * below so that we don't try and process an invalid file descriptor.

   */

  fd = (file < 0) ? NULL : &alt_fd_list[file];

  if (fd)

  {

    switch (cmd)

    {

    case F_GETFL:

      return fd->fd_flags & ~((alt_u32) ALT_FD_FLAGS_MASK);

    case F_SETFL:

      va_start(argp, cmd);

      flags = va_arg(argp, long);

      fd->fd_flags &= ~ALT_FCNTL_FLAGS_MASK;

      fd->fd_flags |= (flags & ALT_FCNTL_FLAGS_MASK);

      va_end(argp);

      return 0;

    default:

      ALT_ERRNO = EINVAL;

      return -1;

    }

  }

  ALT_ERRNO = EBADFD;

  return -1;

}