This is xnu-8019. See this file in:
/*
 * Copyright (c) 2014 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */
#include <sys/cdefs.h>
#include <sys/types.h>
#include <stdarg.h>
#include <sys/fcntl.h>
#include <sys/guarded.h>

int __guarded_open_dprotected_np(const char *path,
    const guardid_t *guard, u_int guardflags, int flags, int dpclass, int dpflags, int mode);

int
guarded_open_dprotected_np(const char *path,
    const guardid_t *guard, u_int guardflags, int flags, int dpclass, int dpflags, ...)
{
	int mode = 0;

	if (flags & O_CREAT) {
		va_list ap;
		va_start(ap, dpflags);
		mode = va_arg(ap, int);
		va_end(ap);
	}
	return __guarded_open_dprotected_np(path, guard, guardflags, flags, dpclass, dpflags, mode);
}