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/* 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;
}
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