xref: /freebsd/bin/setfacl/mask.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/types.h>
28 #include <sys/acl.h>
29 #include <sys/stat.h>
30 
31 #include <err.h>
32 
33 #include "setfacl.h"
34 
35 /* set the appropriate mask the given ACL's */
36 int
37 set_acl_mask(acl_t *prev_acl, const char *filename)
38 {
39 	acl_entry_t entry;
40 	acl_t acl;
41 	acl_tag_t tag;
42 	int entry_id;
43 
44 	entry = NULL;
45 
46 	/*
47 	 * ... if a mask entry is specified, then the permissions of the mask
48 	 * entry in the resulting ACL shall be set to the permissions in the
49 	 * specified ACL mask entry.
50 	 */
51 	if (have_mask)
52 		return (0);
53 
54 	acl = acl_dup(*prev_acl);
55 	if (acl == NULL)
56 		err(1, "%s: acl_dup() failed", filename);
57 
58 	if (!n_flag) {
59 		/*
60 		 * If no mask entry is specified and the -n option is not
61 		 * specified, then the permissions of the resulting ACL mask
62 		 * entry shall be set to the union of the permissions
63 		 * associated with all entries which belong to the file group
64 		 * class in the resulting ACL
65 		 */
66 		if (acl_calc_mask(&acl)) {
67 			warn("%s: acl_calc_mask() failed", filename);
68 			acl_free(acl);
69 			return (-1);
70 		}
71 	} else {
72 		/*
73 		 * If no mask entry is specified and the -n option is
74 		 * specified, then the permissions of the resulting ACL
75 		 * mask entry shall remain unchanged ...
76 		 */
77 
78 		entry_id = ACL_FIRST_ENTRY;
79 
80 		while (acl_get_entry(acl, entry_id, &entry) == 1) {
81 			entry_id = ACL_NEXT_ENTRY;
82 			if (acl_get_tag_type(entry, &tag) == -1)
83 				err(1, "%s: acl_get_tag_type() failed",
84 				    filename);
85 
86 			if (tag == ACL_MASK) {
87 				acl_free(acl);
88 				return (0);
89 			}
90 		}
91 
92 		/*
93 		 * If no mask entry is specified, the -n option is specified,
94 		 * and no ACL mask entry exists in the ACL associated with the
95 		 * file, then write an error message to standard error and
96 		 * continue with the next file.
97 		 */
98 		warnx("%s: warning: no mask entry", filename);
99 		acl_free(acl);
100 		return (0);
101 	}
102 
103 	acl_free(*prev_acl);
104 	*prev_acl = acl_dup(acl);
105 	acl_free(acl);
106 
107 	return (0);
108 }
109