xref: /freebsd/lib/libc/posix1e/acl_from_mode_np.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 Robert N M Watson, Gleb Popov
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  * acl_from_mode_np: Create an ACL from a mode_t.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/acl.h>
38 #include <sys/stat.h>
39 
40 /*
41  * return an ACL corresponding to the permissions
42  * contained in mode_t
43  */
44 acl_t
45 acl_from_mode_np(const mode_t mode)
46 {
47 	acl_t acl;
48 	acl_entry_t entry;
49 	acl_permset_t perms;
50 
51 	/* create the ACL */
52 	acl = acl_init(3);
53 	/* here and below, the only possible reason to fail is ENOMEM, so
54 	 * no need to set errno again
55 	 */
56 	if (acl == NULL)
57 		return (NULL);
58 
59 	/* First entry: ACL_USER_OBJ */
60 	if (acl_create_entry(&acl, &entry) == -1)
61 		return (NULL);
62 	/* TODO: need to handle error there and below? */
63 	acl_set_tag_type(entry, ACL_USER_OBJ);
64 
65 	acl_get_permset(entry, &perms);
66 	acl_clear_perms(perms);
67 
68 	/* calculate user mode */
69 	if (mode & S_IRUSR)
70 		acl_add_perm(perms, ACL_READ);
71 	if (mode & S_IWUSR)
72 		acl_add_perm(perms, ACL_WRITE);
73 	if (mode & S_IXUSR)
74 		acl_add_perm(perms, ACL_EXECUTE);
75 
76 	acl_set_permset(entry, perms);
77 
78 	/* Second entry: ACL_GROUP_OBJ */
79 	if (acl_create_entry(&acl, &entry) == -1)
80 		return (NULL);
81 	acl_set_tag_type(entry, ACL_GROUP_OBJ);
82 
83 	acl_get_permset(entry, &perms);
84 	acl_clear_perms(perms);
85 
86 	/* calculate group mode */
87 	if (mode & S_IRGRP)
88 		acl_add_perm(perms, ACL_READ);
89 	if (mode & S_IWGRP)
90 		acl_add_perm(perms, ACL_WRITE);
91 	if (mode & S_IXGRP)
92 		acl_add_perm(perms, ACL_EXECUTE);
93 
94 	acl_set_permset(entry, perms);
95 
96 	/* Third entry: ACL_OTHER */
97 	if (acl_create_entry(&acl, &entry) == -1)
98 		return (NULL);
99 	acl_set_tag_type(entry, ACL_OTHER);
100 
101 	acl_get_permset(entry, &perms);
102 	acl_clear_perms(perms);
103 
104 	/* calculate other mode */
105 	if (mode & S_IROTH)
106 		acl_add_perm(perms, ACL_READ);
107 	if (mode & S_IWOTH)
108 		acl_add_perm(perms, ACL_WRITE);
109 	if (mode & S_IXOTH)
110 		acl_add_perm(perms, ACL_EXECUTE);
111 
112 	acl_set_permset(entry, perms);
113 
114 	return (acl);
115 }
116