Blame libio/oldiofdopen.c

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/* Copyright (C) 1993-2018 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <http://www.gnu.org/licenses/>.
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   As a special exception, if you link the code in this file with
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   files compiled with a GNU compiler to produce an executable,
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   that does not cause the resulting executable to be covered by
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   the GNU Lesser General Public License.  This exception does not
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   however invalidate any other reasons why the executable file
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   might be covered by the GNU Lesser General Public License.
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   This exception applies to code released by its copyright holders
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   in files containing the exception.  */
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#include <shlib-compat.h>
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#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
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#define _IO_USE_OLD_IO_FILE
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#include <stdlib.h>
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#include "libioP.h"
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#include <fcntl.h>
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FILE *
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attribute_compat_text_section
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_IO_old_fdopen (int fd, const char *mode)
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{
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  int read_write;
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  int posix_mode = 0;
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  struct locked_FILE
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  {
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    struct _IO_FILE_complete_plus fp;
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#ifdef _IO_MTSAFE_IO
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    _IO_lock_t lock;
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#endif
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  } *new_f;
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  int fd_flags;
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  switch (*mode++)
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    {
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    case 'r':
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      read_write = _IO_NO_WRITES;
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      break;
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    case 'w':
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      read_write = _IO_NO_READS;
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      break;
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    case 'a':
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      posix_mode = O_APPEND;
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      read_write = _IO_NO_READS|_IO_IS_APPENDING;
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      break;
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    default:
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      __set_errno (EINVAL);
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      return NULL;
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  }
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  if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
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    read_write &= _IO_IS_APPENDING;
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  fd_flags = __fcntl (fd, F_GETFL);
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  if (fd_flags == -1
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      || ((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES))
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      || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS)))
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    return NULL;
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  /* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b)
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     [System Application Program Interface (API) Amendment 1:
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     Realtime Extensions], Rationale B.8.3.3
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     Open a Stream on a File Descriptor says:
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         Although not explicitly required by POSIX.1, a good
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         implementation of append ("a") mode would cause the
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         O_APPEND flag to be set.
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     (Historical implementations [such as Solaris2] do a one-time
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     seek in fdopen.)
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     However, we do not turn O_APPEND off if the mode is "w" (even
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     though that would seem consistent) because that would be more
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     likely to break historical programs.
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     */
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  if ((posix_mode & O_APPEND) && !(fd_flags & O_APPEND))
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    {
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      if (__fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1)
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	return NULL;
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    }
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  new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
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  if (new_f == NULL)
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    return NULL;
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#ifdef _IO_MTSAFE_IO
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  new_f->fp.file._file._lock = &new_f->lock;
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#endif
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  _IO_old_init (&new_f->fp.file._file, 0);
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  _IO_JUMPS_FILE_plus (&new_f->fp) = &_IO_old_file_jumps;
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  _IO_old_file_init_internal ((struct _IO_FILE_plus *) &new_f->fp);
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  if (_IO_old_file_attach (&new_f->fp.file._file, fd) == NULL)
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    {
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      _IO_un_link ((struct _IO_FILE_plus *) &new_f->fp);
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      free (new_f);
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      return NULL;
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    }
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  new_f->fp.file._file._flags &= ~_IO_DELETE_DONT_CLOSE;
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  _IO_mask_flags (&new_f->fp.file._file, read_write,
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		  _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
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  return (FILE *) &new_f->fp;
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}
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strong_alias (_IO_old_fdopen, __old_fdopen)
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compat_symbol (libc, _IO_old_fdopen, _IO_fdopen, GLIBC_2_0);
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compat_symbol (libc, __old_fdopen, fdopen, GLIBC_2_0);
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#endif