1/*	$NetBSD: mask.c,v 1.1 2020/05/16 18:31:45 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2001-2002 Chris D. Faulhaber
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30#if 0
31__FBSDID("$FreeBSD: head/bin/setfacl/mask.c 333065 2018-04-27 15:25:24Z emaste $");
32#else
33__RCSID("$NetBSD: mask.c,v 1.1 2020/05/16 18:31:45 christos Exp $");
34#endif
35
36#include <sys/types.h>
37#include <sys/acl.h>
38#include <sys/stat.h>
39
40#include <err.h>
41#include <errno.h>
42#include <stdio.h>
43#include <stdlib.h>
44
45#include "setfacl.h"
46
47/* set the appropriate mask the given ACL's */
48int
49set_acl_mask(acl_t *prev_acl, const char *filename)
50{
51	acl_entry_t entry;
52	acl_t acl;
53	acl_tag_t tag;
54	int entry_id;
55
56	entry = NULL;
57
58	/*
59	 * ... if a mask entry is specified, then the permissions of the mask
60	 * entry in the resulting ACL shall be set to the permissions in the
61	 * specified ACL mask entry.
62	 */
63	if (have_mask)
64		return (0);
65
66	acl = acl_dup(*prev_acl);
67	if (acl == NULL)
68		err(1, "%s: acl_dup() failed", filename);
69
70	if (!n_flag) {
71		/*
72		 * If no mask entry is specified and the -n option is not
73		 * specified, then the permissions of the resulting ACL mask
74		 * entry shall be set to the union of the permissions
75		 * associated with all entries which belong to the file group
76		 * class in the resulting ACL
77		 */
78		if (acl_calc_mask(&acl)) {
79			warn("%s: acl_calc_mask() failed", filename);
80			acl_free(acl);
81			return (-1);
82		}
83	} else {
84		/*
85		 * If no mask entry is specified and the -n option is
86		 * specified, then the permissions of the resulting ACL
87		 * mask entry shall remain unchanged ...
88		 */
89
90		entry_id = ACL_FIRST_ENTRY;
91
92		while (acl_get_entry(acl, entry_id, &entry) == 1) {
93			entry_id = ACL_NEXT_ENTRY;
94			if (acl_get_tag_type(entry, &tag) == -1)
95				err(1, "%s: acl_get_tag_type() failed",
96				    filename);
97
98			if (tag == ACL_MASK) {
99				acl_free(acl);
100				return (0);
101			}
102		}
103
104		/*
105		 * If no mask entry is specified, the -n option is specified,
106		 * and no ACL mask entry exists in the ACL associated with the
107		 * file, then write an error message to standard error and
108		 * continue with the next file.
109		 */
110		warnx("%s: warning: no mask entry", filename);
111		acl_free(acl);
112		return (0);
113	}
114
115	acl_free(*prev_acl);
116	*prev_acl = acl_dup(acl);
117	acl_free(acl);
118
119	return (0);
120}
121