xref: /netbsd-src/bin/setfacl/mask.c (revision 9aa2a9c323eb12a08584c70d6ea91d316703d3fe)
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 */
48 int
set_acl_mask(acl_t * prev_acl,const char * filename)49 set_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