xref: /freebsd/bin/setfacl/mask.c (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*-
2  * Copyright (c) 2001-2002 Chris D. Faulhaber
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/types.h>
31 #include <sys/acl.h>
32 #include <sys/stat.h>
33 
34 #include <err.h>
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 
39 #include "setfacl.h"
40 
41 /* set the appropriate mask the given ACL's */
42 int
43 set_acl_mask(acl_t *prev_acl, const char *filename)
44 {
45 	acl_entry_t entry;
46 	acl_t acl;
47 	acl_tag_t tag;
48 	int entry_id;
49 
50 	entry = NULL;
51 
52 	/*
53 	 * ... if a mask entry is specified, then the permissions of the mask
54 	 * entry in the resulting ACL shall be set to the permissions in the
55 	 * specified ACL mask entry.
56 	 */
57 	if (have_mask)
58 		return (0);
59 
60 	acl = acl_dup(*prev_acl);
61 	if (acl == NULL)
62 		err(1, "%s: acl_dup() failed", filename);
63 
64 	if (!n_flag) {
65 		/*
66 		 * If no mask entry is specified and the -n option is not
67 		 * specified, then the permissions of the resulting ACL mask
68 		 * entry shall be set to the union of the permissions
69 		 * associated with all entries which belong to the file group
70 		 * class in the resulting ACL
71 		 */
72 		if (acl_calc_mask(&acl)) {
73 			warn("%s: acl_calc_mask() failed", filename);
74 			acl_free(acl);
75 			return (-1);
76 		}
77 	} else {
78 		/*
79 		 * If no mask entry is specified and the -n option is
80 		 * specified, then the permissions of the resulting ACL
81 		 * mask entry shall remain unchanged ...
82 		 */
83 
84 		entry_id = ACL_FIRST_ENTRY;
85 
86 		while (acl_get_entry(acl, entry_id, &entry) == 1) {
87 			entry_id = ACL_NEXT_ENTRY;
88 			if (acl_get_tag_type(entry, &tag) == -1)
89 				err(1, "%s: acl_get_tag_type() failed",
90 				    filename);
91 
92 			if (tag == ACL_MASK) {
93 				acl_free(acl);
94 				return (0);
95 			}
96 		}
97 
98 		/*
99 		 * If no mask entry is specified, the -n option is specified,
100 		 * and no ACL mask entry exists in the ACL associated with the
101 		 * file, then write an error message to standard error and
102 		 * continue with the next file.
103 		 */
104 		warnx("%s: warning: no mask entry", filename);
105 		acl_free(acl);
106 		return (0);
107 	}
108 
109 	acl_free(*prev_acl);
110 	*prev_acl = acl_dup(acl);
111 	acl_free(acl);
112 
113 	return (0);
114 }
115