/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2001-2002 Chris D. Faulhaber
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS 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>
#if 0
__FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_perm.c 326193 2017-11-25 17:12:48Z pfg $");
#else
__RCSID("$NetBSD: acl_perm.c,v 1.1 2020/05/16 18:31:47 christos Exp $");
#endif

#include "namespace.h"
#include <sys/types.h>
#include <sys/acl.h>

#include <errno.h>
#include <string.h>

static int
_perm_is_invalid(acl_perm_t perm)
{

	/* Check if more than a single bit is set. */
	if ((perm & -perm) == perm &&
	    (perm & (ACL_POSIX1E_BITS | ACL_NFS4_PERM_BITS)) == perm)
		return (0);

	errno = EINVAL;

	return (1);
}

/*
 * acl_add_perm() (23.4.1): add the permission contained in perm to the
 * permission set permset_d
 */
int
acl_add_perm(acl_permset_t permset_d, acl_perm_t perm)
{

	if (permset_d == NULL) {
		errno = EINVAL;
		return (-1);
	}

	if (_perm_is_invalid(perm))
		return (-1);

	*permset_d |= perm;

	return (0);
}

/*
 * acl_clear_perms() (23.4.3): clear all permisions from the permission
 * set permset_d
 */
int
acl_clear_perms(acl_permset_t permset_d)
{

	if (permset_d == NULL) {
		errno = EINVAL;
		return (-1);
	}

	*permset_d = ACL_PERM_NONE;

	return (0);
}

/*
 * acl_delete_perm() (23.4.10): remove the permission in perm from the
 * permission set permset_d
 */
int
acl_delete_perm(acl_permset_t permset_d, acl_perm_t perm)
{

	if (permset_d == NULL) {
		errno = EINVAL;
		return (-1);
	}

	if (_perm_is_invalid(perm))
		return (-1);

	*permset_d &= ~perm;

	return (0);
}

int
acl_get_perm_np(acl_permset_t permset_d, acl_perm_t perm)
{

	if (permset_d == NULL) {
		errno = EINVAL;
		return (-1);
	}

	if (_perm_is_invalid(perm))
		return (-1);

	if (*permset_d & perm)
		return (1);

	return (0);
}