/* Test duplicating non-inheritable file descriptors.

   Copyright (C) 2009-2020 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program 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 General Public License for more details.

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

   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Eric Blake <ebb9@byu.net>, 2009.  */

#include <config.h>

#include "cloexec.h"

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#if defined _WIN32 && ! defined __CYGWIN__

/* Get declarations of the native Windows API functions.  */

# define WIN32_LEAN_AND_MEAN

# include <windows.h>

/* Get _get_osfhandle.  */

# if GNULIB_MSVC_NOTHROW

#  include "msvc-nothrow.h"

# else

#  include <io.h>

# endif

#endif

#include "binary-io.h"

#include "macros.h"

/* Return non-zero if FD is open and inheritable across exec/spawn.  */

static int

is_inheritable (int fd)

{

#if defined _WIN32 && ! defined __CYGWIN__

  /* On native Windows, the initial state of unassigned standard file

     descriptors is that they are open but point to an

     INVALID_HANDLE_VALUE, and there is no fcntl.  */

  HANDLE h = (HANDLE) _get_osfhandle (fd);

  DWORD flags;

  if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0)

    return 0;

  return (flags & HANDLE_FLAG_INHERIT) != 0;

#else

# ifndef F_GETFD

#  error Please port fcntl to your platform

# endif

  int i = fcntl (fd, F_GETFD);

  return 0 <= i && (i & FD_CLOEXEC) == 0;

#endif

}

#if !O_BINARY

# define setmode(f,m) zero ()

static int zero (void) { return 0; }

#endif

/* Return non-zero if FD is open in the given MODE, which is either

   O_TEXT or O_BINARY.  */

static int

is_mode (int fd, int mode)

{

  int value = setmode (fd, O_BINARY);

  setmode (fd, value);

  return mode == value;

}

int

main (void)

{

  const char *file = "test-cloexec.tmp";

  int fd = creat (file, 0600);

  int fd2;

  int bad_fd = getdtablesize ();

  /* Assume std descriptors were provided by invoker.  */

  ASSERT (STDERR_FILENO < fd);

  ASSERT (is_inheritable (fd));

  /* Normal use of set_cloexec_flag.  */

  ASSERT (set_cloexec_flag (fd, true) == 0);

#if !(defined _WIN32 && ! defined __CYGWIN__)

  ASSERT (!is_inheritable (fd));

#endif

  ASSERT (set_cloexec_flag (fd, false) == 0);

  ASSERT (is_inheritable (fd));

  /* Normal use of dup_cloexec.  */

  fd2 = dup_cloexec (fd);

  ASSERT (fd < fd2);

  ASSERT (!is_inheritable (fd2));

  ASSERT (close (fd) == 0);

  ASSERT (dup_cloexec (fd2) == fd);

  ASSERT (!is_inheritable (fd));

  ASSERT (close (fd2) == 0);

  /* On systems that distinguish between text and binary mode,

     dup_cloexec reuses the mode of the source.  */

  setmode (fd, O_BINARY);

  ASSERT (is_mode (fd, O_BINARY));

  fd2 = dup_cloexec (fd);

  ASSERT (fd < fd2);

  ASSERT (is_mode (fd2, O_BINARY));

  ASSERT (close (fd2) == 0);

  setmode (fd, O_TEXT);

  ASSERT (is_mode (fd, O_TEXT));

  fd2 = dup_cloexec (fd);

  ASSERT (fd < fd2);

  ASSERT (is_mode (fd2, O_TEXT));

  ASSERT (close (fd2) == 0);

  /* Test error handling.  */

  errno = 0;

  ASSERT (set_cloexec_flag (-1, false) == -1);

  ASSERT (errno == EBADF);

  errno = 0;

  ASSERT (set_cloexec_flag (bad_fd, false) == -1);

  ASSERT (errno == EBADF);

  errno = 0;

  ASSERT (set_cloexec_flag (fd2, false) == -1);

  ASSERT (errno == EBADF);

  errno = 0;

  ASSERT (dup_cloexec (-1) == -1);

  ASSERT (errno == EBADF);

  errno = 0;

  ASSERT (dup_cloexec (bad_fd) == -1);

  ASSERT (errno == EBADF);

  errno = 0;

  ASSERT (dup_cloexec (fd2) == -1);

  ASSERT (errno == EBADF);

  /* Clean up.  */

  ASSERT (close (fd) == 0);

  ASSERT (unlink (file) == 0);

  return 0;

}