xref: /freebsd/bin/setfacl/mask.c (revision 89e3d5671ba13dceca272d5b159c9bd805f3f504)
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 
36 #include "setfacl.h"
37 
38 /* set the appropriate mask the given ACL's */
39 int
40 set_acl_mask(acl_t *prev_acl, const char *filename)
41 {
42 	acl_entry_t entry;
43 	acl_t acl;
44 	acl_tag_t tag;
45 	int entry_id;
46 
47 	entry = NULL;
48 
49 	/*
50 	 * ... if a mask entry is specified, then the permissions of the mask
51 	 * entry in the resulting ACL shall be set to the permissions in the
52 	 * specified ACL mask entry.
53 	 */
54 	if (have_mask)
55 		return (0);
56 
57 	acl = acl_dup(*prev_acl);
58 	if (acl == NULL)
59 		err(1, "%s: acl_dup() failed", filename);
60 
61 	if (!n_flag) {
62 		/*
63 		 * If no mask entry is specified and the -n option is not
64 		 * specified, then the permissions of the resulting ACL mask
65 		 * entry shall be set to the union of the permissions
66 		 * associated with all entries which belong to the file group
67 		 * class in the resulting ACL
68 		 */
69 		if (acl_calc_mask(&acl)) {
70 			warn("%s: acl_calc_mask() failed", filename);
71 			acl_free(acl);
72 			return (-1);
73 		}
74 	} else {
75 		/*
76 		 * If no mask entry is specified and the -n option is
77 		 * specified, then the permissions of the resulting ACL
78 		 * mask entry shall remain unchanged ...
79 		 */
80 
81 		entry_id = ACL_FIRST_ENTRY;
82 
83 		while (acl_get_entry(acl, entry_id, &entry) == 1) {
84 			entry_id = ACL_NEXT_ENTRY;
85 			if (acl_get_tag_type(entry, &tag) == -1)
86 				err(1, "%s: acl_get_tag_type() failed",
87 				    filename);
88 
89 			if (tag == ACL_MASK) {
90 				acl_free(acl);
91 				return (0);
92 			}
93 		}
94 
95 		/*
96 		 * If no mask entry is specified, the -n option is specified,
97 		 * and no ACL mask entry exists in the ACL associated with the
98 		 * file, then write an error message to standard error and
99 		 * continue with the next file.
100 		 */
101 		warnx("%s: warning: no mask entry", filename);
102 		acl_free(acl);
103 		return (0);
104 	}
105 
106 	acl_free(*prev_acl);
107 	*prev_acl = acl_dup(acl);
108 	acl_free(acl);
109 
110 	return (0);
111 }
112