xref: /freebsd/lib/libc/posix1e/acl_from_mode_np.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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/cdefs.h>
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/acl.h>
36 #include <sys/stat.h>
37 
38 /*
39  * return an ACL corresponding to the permissions
40  * contained in mode_t
41  */
42 acl_t
43 acl_from_mode_np(const mode_t mode)
44 {
45 	acl_t acl;
46 	acl_entry_t entry;
47 	acl_permset_t perms;
48 
49 	/* create the ACL */
50 	acl = acl_init(3);
51 	/* here and below, the only possible reason to fail is ENOMEM, so
52 	 * no need to set errno again
53 	 */
54 	if (acl == NULL)
55 		return (NULL);
56 
57 	/* First entry: ACL_USER_OBJ */
58 	if (acl_create_entry(&acl, &entry) == -1)
59 		return (NULL);
60 	/* TODO: need to handle error there and below? */
61 	acl_set_tag_type(entry, ACL_USER_OBJ);
62 
63 	acl_get_permset(entry, &perms);
64 	acl_clear_perms(perms);
65 
66 	/* calculate user mode */
67 	if (mode & S_IRUSR)
68 		acl_add_perm(perms, ACL_READ);
69 	if (mode & S_IWUSR)
70 		acl_add_perm(perms, ACL_WRITE);
71 	if (mode & S_IXUSR)
72 		acl_add_perm(perms, ACL_EXECUTE);
73 
74 	acl_set_permset(entry, perms);
75 
76 	/* Second entry: ACL_GROUP_OBJ */
77 	if (acl_create_entry(&acl, &entry) == -1)
78 		return (NULL);
79 	acl_set_tag_type(entry, ACL_GROUP_OBJ);
80 
81 	acl_get_permset(entry, &perms);
82 	acl_clear_perms(perms);
83 
84 	/* calculate group mode */
85 	if (mode & S_IRGRP)
86 		acl_add_perm(perms, ACL_READ);
87 	if (mode & S_IWGRP)
88 		acl_add_perm(perms, ACL_WRITE);
89 	if (mode & S_IXGRP)
90 		acl_add_perm(perms, ACL_EXECUTE);
91 
92 	acl_set_permset(entry, perms);
93 
94 	/* Third entry: ACL_OTHER */
95 	if (acl_create_entry(&acl, &entry) == -1)
96 		return (NULL);
97 	acl_set_tag_type(entry, ACL_OTHER);
98 
99 	acl_get_permset(entry, &perms);
100 	acl_clear_perms(perms);
101 
102 	/* calculate other mode */
103 	if (mode & S_IROTH)
104 		acl_add_perm(perms, ACL_READ);
105 	if (mode & S_IWOTH)
106 		acl_add_perm(perms, ACL_WRITE);
107 	if (mode & S_IXOTH)
108 		acl_add_perm(perms, ACL_EXECUTE);
109 
110 	acl_set_permset(entry, perms);
111 
112 	return (acl);
113 }
114