/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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 THE 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/types.h>
#include <sys/acl.h>
#include <sys/stat.h>

#include <err.h>

#include "setfacl.h"

/* set the appropriate mask the given ACL's */
int
set_acl_mask(acl_t *prev_acl, const char *filename)
{
        acl_entry_t entry;
        acl_t acl;
        acl_tag_t tag;
        int entry_id;

        entry = NULL;

        /*
         * ... if a mask entry is specified, then the permissions of the mask
         * entry in the resulting ACL shall be set to the permissions in the
         * specified ACL mask entry.
         */
        if (have_mask)
                return (0);

        acl = acl_dup(*prev_acl);
        if (acl == NULL)
                err(1, "%s: acl_dup() failed", filename);

        if (!n_flag) {
                /*
                 * If no mask entry is specified and the -n option is not
                 * specified, then the permissions of the resulting ACL mask
                 * entry shall be set to the union of the permissions
                 * associated with all entries which belong to the file group
                 * class in the resulting ACL
                 */
                if (acl_calc_mask(&acl)) {
                        warn("%s: acl_calc_mask() failed", filename);
                        acl_free(acl);
                        return (-1);
                }
        } else {
                /*
                 * If no mask entry is specified and the -n option is
                 * specified, then the permissions of the resulting ACL
                 * mask entry shall remain unchanged ...
                 */

                entry_id = ACL_FIRST_ENTRY;

                while (acl_get_entry(acl, entry_id, &entry) == 1) {
                        entry_id = ACL_NEXT_ENTRY;
                        if (acl_get_tag_type(entry, &tag) == -1)
                                err(1, "%s: acl_get_tag_type() failed",
                                    filename);

                        if (tag == ACL_MASK) {
                                acl_free(acl);
                                return (0);
                        }
                }

                /*
                 * If no mask entry is specified, the -n option is specified,
                 * and no ACL mask entry exists in the ACL associated with the
                 * file, then write an error message to standard error and
                 * continue with the next file.
                 */
                warnx("%s: warning: no mask entry", filename);
                acl_free(acl);
                return (0);
        }

        acl_free(*prev_acl);
        *prev_acl = acl_dup(acl);
        acl_free(acl);

        return (0);
}