/* Copyright (C) 1993-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.

   As a special exception, if you link the code in this file with

   files compiled with a GNU compiler to produce an executable,

   that does not cause the resulting executable to be covered by

   the GNU Lesser General Public License.  This exception does not

   however invalidate any other reasons why the executable file

   might be covered by the GNU Lesser General Public License.

   This exception applies to code released by its copyright holders

   in files containing the exception.  */

#include <stdlib.h>

#include "libioP.h"

#include <fcntl.h>

#include <shlib-compat.h>

FILE *

_IO_new_fdopen (int fd, const char *mode)

{

  int read_write;

  struct locked_FILE

  {

    struct _IO_FILE_plus fp;

#ifdef _IO_MTSAFE_IO

    _IO_lock_t lock;

#endif

    struct _IO_wide_data wd;

  } *new_f;

  int i;

  int use_mmap = 0;

  /* Decide whether we modify the offset of the file we attach to and seek to

     the end of file.  We only do this if the mode is 'a' and if the file

     descriptor did not have O_APPEND in its flags already.  */

  bool do_seek = false;

  switch (*mode)

    {

    case 'r':

      read_write = _IO_NO_WRITES;

      break;

    case 'w':

      read_write = _IO_NO_READS;

      break;

    case 'a':

      read_write = _IO_NO_READS|_IO_IS_APPENDING;

      break;

    default:

      __set_errno (EINVAL);

      return NULL;

  }

  for (i = 1; i < 5; ++i)

    {

      switch (*++mode)

	{

	case '\0':

	  break;

	case '+':

	  read_write &= _IO_IS_APPENDING;

	  break;

	case 'm':

	  use_mmap = 1;

	  continue;

	case 'x':

	case 'b':

	default:

	  /* Ignore */

	  continue;

	}

      break;

    }

  int fd_flags = __fcntl (fd, F_GETFL);

  if (fd_flags == -1)

    return NULL;

  if (((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES))

      || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS)))

    {

      __set_errno (EINVAL);

      return NULL;

    }

  /* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b)

     [System Application Program Interface (API) Amendment 1:

     Realtime Extensions], Rationale B.8.3.3

     Open a Stream on a File Descriptor says:

	 Although not explicitly required by POSIX.1, a good

	 implementation of append ("a") mode would cause the

	 O_APPEND flag to be set.

     (Historical implementations [such as Solaris2] do a one-time

     seek in fdopen.)

     However, we do not turn O_APPEND off if the mode is "w" (even

     though that would seem consistent) because that would be more

     likely to break historical programs.

     */

  if ((read_write & _IO_IS_APPENDING) && !(fd_flags & O_APPEND))

    {

      do_seek = true;

      if (__fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1)

	return NULL;

    }

  new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));

  if (new_f == NULL)

    return NULL;

#ifdef _IO_MTSAFE_IO

  new_f->fp.file._lock = &new_f->lock;

#endif

  _IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd,

#if _G_HAVE_MMAP

	       (use_mmap && (read_write & _IO_NO_WRITES))

	       ? &_IO_wfile_jumps_maybe_mmap :

#endif

	       &_IO_wfile_jumps);

  _IO_JUMPS (&new_f->fp) =

#if _G_HAVE_MMAP

    (use_mmap && (read_write & _IO_NO_WRITES)) ? &_IO_file_jumps_maybe_mmap :

#endif

      &_IO_file_jumps;

  _IO_new_file_init_internal (&new_f->fp);

  /* We only need to record the fd because _IO_file_init_internal will

     have unset the offset.  It is important to unset the cached

     offset because the real offset in the file could change between

     now and when the handle is activated and we would then mislead

     ftell into believing that we have a valid offset.  */

  new_f->fp.file._fileno = fd;

  new_f->fp.file._flags &= ~_IO_DELETE_DONT_CLOSE;

  _IO_mask_flags (&new_f->fp.file, read_write,

		  _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);

  /* For append mode, set the file offset to the end of the file if we added

     O_APPEND to the file descriptor flags.  Don't update the offset cache

     though, since the file handle is not active.  */

  if (do_seek && ((read_write & (_IO_IS_APPENDING | _IO_NO_READS))

		  == (_IO_IS_APPENDING | _IO_NO_READS)))

    {

      off64_t new_pos = _IO_SYSSEEK (&new_f->fp.file, 0, _IO_seek_end);

      if (new_pos == _IO_pos_BAD && errno != ESPIPE)

	return NULL;

    }

  return &new_f->fp.file;

}

libc_hidden_ver (_IO_new_fdopen, _IO_fdopen)

strong_alias (_IO_new_fdopen, __new_fdopen)

versioned_symbol (libc, _IO_new_fdopen, _IO_fdopen, GLIBC_2_1);

versioned_symbol (libc, __new_fdopen, fdopen, GLIBC_2_1);