/*
 * Copyright 2000 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "namespace.h"
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>

#include <errno.h>
#include <unistd.h>
#include "un-namespace.h"

static int _shm_in_kernel = -1;

/* Wrappers for POSIX SHM system calls in newer kernels. */
static __inline int
_shm_open(const char *path, int flags, mode_t mode)
{

    return (syscall(482, path, flags, mode));
}

static __inline int
_shm_unlink(const char *path)
{

    return (syscall(483, path));
}

int
shm_open(const char *path, int flags, mode_t mode)
{
	int fd;
	struct stat stab;

	if (_shm_in_kernel == -1)
		_shm_in_kernel = feature_present("posix_shm");
	if (_shm_in_kernel == 1)
		return (_shm_open(path, flags, mode));

	if ((flags & O_ACCMODE) == O_WRONLY)
		return (EINVAL);

	fd = _open(path, flags, mode);
	if (fd != -1) {
		if (_fstat(fd, &stab) != 0 || !S_ISREG(stab.st_mode)) {
			_close(fd);
			errno = EINVAL;
			return (-1);
		}

		if (_fcntl(fd, F_SETFL, (int)FPOSIXSHM) != 0) {
			_close(fd);
			return (-1);
		}
	}
	return (fd);
}

int
shm_unlink(const char *path)
{

	if (_shm_in_kernel == -1)
		_shm_in_kernel = feature_present("posix_shm");
	if (_shm_in_kernel == 1)
		return (_shm_unlink(path));

	return (unlink(path));
}