xref: /freebsd/bin/setfacl/mask.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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 #include <sys/types.h>
29 #include <sys/acl.h>
30 #include <sys/stat.h>
31 
32 #include <err.h>
33 
34 #include "setfacl.h"
35 
36 /* set the appropriate mask the given ACL's */
37 int
38 set_acl_mask(acl_t *prev_acl, const char *filename)
39 {
40 	acl_entry_t entry;
41 	acl_t acl;
42 	acl_tag_t tag;
43 	int entry_id;
44 
45 	entry = NULL;
46 
47 	/*
48 	 * ... if a mask entry is specified, then the permissions of the mask
49 	 * entry in the resulting ACL shall be set to the permissions in the
50 	 * specified ACL mask entry.
51 	 */
52 	if (have_mask)
53 		return (0);
54 
55 	acl = acl_dup(*prev_acl);
56 	if (acl == NULL)
57 		err(1, "%s: acl_dup() failed", filename);
58 
59 	if (!n_flag) {
60 		/*
61 		 * If no mask entry is specified and the -n option is not
62 		 * specified, then the permissions of the resulting ACL mask
63 		 * entry shall be set to the union of the permissions
64 		 * associated with all entries which belong to the file group
65 		 * class in the resulting ACL
66 		 */
67 		if (acl_calc_mask(&acl)) {
68 			warn("%s: acl_calc_mask() failed", filename);
69 			acl_free(acl);
70 			return (-1);
71 		}
72 	} else {
73 		/*
74 		 * If no mask entry is specified and the -n option is
75 		 * specified, then the permissions of the resulting ACL
76 		 * mask entry shall remain unchanged ...
77 		 */
78 
79 		entry_id = ACL_FIRST_ENTRY;
80 
81 		while (acl_get_entry(acl, entry_id, &entry) == 1) {
82 			entry_id = ACL_NEXT_ENTRY;
83 			if (acl_get_tag_type(entry, &tag) == -1)
84 				err(1, "%s: acl_get_tag_type() failed",
85 				    filename);
86 
87 			if (tag == ACL_MASK) {
88 				acl_free(acl);
89 				return (0);
90 			}
91 		}
92 
93 		/*
94 		 * If no mask entry is specified, the -n option is specified,
95 		 * and no ACL mask entry exists in the ACL associated with the
96 		 * file, then write an error message to standard error and
97 		 * continue with the next file.
98 		 */
99 		warnx("%s: warning: no mask entry", filename);
100 		acl_free(acl);
101 		return (0);
102 	}
103 
104 	acl_free(*prev_acl);
105 	*prev_acl = acl_dup(acl);
106 	acl_free(acl);
107 
108 	return (0);
109 }
110