xref: /freebsd/lib/libc/posix1e/acl_branding.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008, 2009 Edward Tomasz Napierała <trasz@FreeBSD.org>
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 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <assert.h>
33 #include <errno.h>
34 #include <sys/acl.h>
35 
36 #include "acl_support.h"
37 
38 /*
39  * An ugly detail of the implementation - fortunately not visible
40  * to the API users - is the "branding": libc needs to keep track
41  * of what "brand" ACL is: NFSv4, POSIX.1e or unknown.  It happens
42  * automatically - for example, during acl_get_file(3) ACL gets
43  * branded according to the "type" argument; during acl_set_permset
44  * ACL, if its brand is unknown it gets branded as NFSv4 if any of the
45  * NFSv4 permissions that are not valid for POSIX.1e ACL are set etc.
46  * Branding information is used for printing out the ACL (acl_to_text(3)),
47  * veryfying acl_set_whatever arguments (checking against setting
48  * bits that are valid only for NFSv4 in ACL branded as POSIX.1e) etc.
49  */
50 
51 static acl_t
52 entry2acl(acl_entry_t entry)
53 {
54 	acl_t aclp;
55 
56 	aclp = (acl_t)(((long)entry >> _ACL_T_ALIGNMENT_BITS) << _ACL_T_ALIGNMENT_BITS);
57 
58 	return (aclp);
59 }
60 
61 /*
62  * Return brand of an ACL.
63  */
64 int
65 _acl_brand(const acl_t acl)
66 {
67 
68 	return (acl->ats_brand);
69 }
70 
71 int
72 _entry_brand(const acl_entry_t entry)
73 {
74 
75 	return (_acl_brand(entry2acl(entry)));
76 }
77 
78 /*
79  * Return 1, iff branding ACL as "brand" is ok.
80  */
81 int
82 _acl_brand_may_be(const acl_t acl, int brand)
83 {
84 
85 	if (_acl_brand(acl) == ACL_BRAND_UNKNOWN)
86 		return (1);
87 
88 	if (_acl_brand(acl) == brand)
89 		return (1);
90 
91 	return (0);
92 }
93 
94 int
95 _entry_brand_may_be(const acl_entry_t entry, int brand)
96 {
97 
98 	return (_acl_brand_may_be(entry2acl(entry), brand));
99 }
100 
101 /*
102  * Brand ACL as "brand".
103  */
104 void
105 _acl_brand_as(acl_t acl, int brand)
106 {
107 
108 	assert(_acl_brand_may_be(acl, brand));
109 
110 	acl->ats_brand = brand;
111 }
112 
113 void
114 _entry_brand_as(const acl_entry_t entry, int brand)
115 {
116 
117 	_acl_brand_as(entry2acl(entry), brand);
118 }
119 
120 int
121 _acl_type_not_valid_for_acl(const acl_t acl, acl_type_t type)
122 {
123 
124 	switch (_acl_brand(acl)) {
125 	case ACL_BRAND_NFS4:
126 		if (type == ACL_TYPE_NFS4)
127 			return (0);
128 		break;
129 
130 	case ACL_BRAND_POSIX:
131 		if (type == ACL_TYPE_ACCESS || type == ACL_TYPE_DEFAULT)
132 			return (0);
133 		break;
134 
135 	case ACL_BRAND_UNKNOWN:
136 		return (0);
137 	}
138 
139 	return (-1);
140 }
141 
142 void
143 _acl_brand_from_type(acl_t acl, acl_type_t type)
144 {
145 
146 	switch (type) {
147 	case ACL_TYPE_NFS4:
148 		_acl_brand_as(acl, ACL_BRAND_NFS4);
149 		break;
150 	case ACL_TYPE_ACCESS:
151 	case ACL_TYPE_DEFAULT:
152 		_acl_brand_as(acl, ACL_BRAND_POSIX);
153 		break;
154 	default:
155 		/* XXX: What to do here? */
156 		break;
157 	}
158 }
159 
160 int
161 acl_get_brand_np(acl_t acl, int *brand_p)
162 {
163 
164 	if (acl == NULL || brand_p == NULL) {
165 		errno = EINVAL;
166 		return (-1);
167 	}
168 	*brand_p = _acl_brand(acl);
169 
170 	return (0);
171 }
172