xref: /freebsd/lib/libc/posix1e/acl_from_mode_np.c (revision 7c43148a974877188a930e4078a164f83da8e652)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/types.h>
33 #include <sys/param.h>
34 #include <sys/acl.h>
35 #include <sys/stat.h>
36 
37 /*
38  * return an ACL corresponding to the permissions
39  * contained in mode_t
40  */
41 acl_t
42 acl_from_mode_np(const mode_t mode)
43 {
44 	acl_t acl;
45 	acl_entry_t entry;
46 	acl_permset_t perms;
47 
48 	/* create the ACL */
49 	acl = acl_init(3);
50 	/* here and below, the only possible reason to fail is ENOMEM, so
51 	 * no need to set errno again
52 	 */
53 	if (acl == NULL)
54 		return (NULL);
55 
56 	/* First entry: ACL_USER_OBJ */
57 	if (acl_create_entry(&acl, &entry) == -1)
58 		return (NULL);
59 	/* TODO: need to handle error there and below? */
60 	acl_set_tag_type(entry, ACL_USER_OBJ);
61 
62 	acl_get_permset(entry, &perms);
63 	acl_clear_perms(perms);
64 
65 	/* calculate user mode */
66 	if (mode & S_IRUSR)
67 		acl_add_perm(perms, ACL_READ);
68 	if (mode & S_IWUSR)
69 		acl_add_perm(perms, ACL_WRITE);
70 	if (mode & S_IXUSR)
71 		acl_add_perm(perms, ACL_EXECUTE);
72 
73 	acl_set_permset(entry, perms);
74 
75 	/* Second entry: ACL_GROUP_OBJ */
76 	if (acl_create_entry(&acl, &entry) == -1)
77 		return (NULL);
78 	acl_set_tag_type(entry, ACL_GROUP_OBJ);
79 
80 	acl_get_permset(entry, &perms);
81 	acl_clear_perms(perms);
82 
83 	/* calculate group mode */
84 	if (mode & S_IRGRP)
85 		acl_add_perm(perms, ACL_READ);
86 	if (mode & S_IWGRP)
87 		acl_add_perm(perms, ACL_WRITE);
88 	if (mode & S_IXGRP)
89 		acl_add_perm(perms, ACL_EXECUTE);
90 
91 	acl_set_permset(entry, perms);
92 
93 	/* Third entry: ACL_OTHER */
94 	if (acl_create_entry(&acl, &entry) == -1)
95 		return (NULL);
96 	acl_set_tag_type(entry, ACL_OTHER);
97 
98 	acl_get_permset(entry, &perms);
99 	acl_clear_perms(perms);
100 
101 	/* calculate other mode */
102 	if (mode & S_IROTH)
103 		acl_add_perm(perms, ACL_READ);
104 	if (mode & S_IWOTH)
105 		acl_add_perm(perms, ACL_WRITE);
106 	if (mode & S_IXOTH)
107 		acl_add_perm(perms, ACL_EXECUTE);
108 
109 	acl_set_permset(entry, perms);
110 
111 	return (acl);
112 }
113