acl_branding.c revision 331722 
1/*-
2 * Copyright (c) 2008, 2009 Edward Tomasz Napiera��a <trasz@FreeBSD.org>
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/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/lib/libc/posix1e/acl_branding.c 331722 2018-03-29 02:50:57Z eadler $");
29
30#include <assert.h>
31#include <errno.h>
32#include <sys/acl.h>
33
34#include "acl_support.h"
35
36/*
37 * An ugly detail of the implementation - fortunately not visible
38 * to the API users - is the "branding": libc needs to keep track
39 * of what "brand" ACL is: NFSv4, POSIX.1e or unknown.  It happens
40 * automatically - for example, during acl_get_file(3) ACL gets
41 * branded according to the "type" argument; during acl_set_permset
42 * ACL, if its brand is unknown it gets branded as NFSv4 if any of the
43 * NFSv4 permissions that are not valid for POSIX.1e ACL are set etc.
44 * Branding information is used for printing out the ACL (acl_to_text(3)),
45 * veryfying acl_set_whatever arguments (checking against setting
46 * bits that are valid only for NFSv4 in ACL branded as POSIX.1e) etc.
47 */
48
49static acl_t
50entry2acl(acl_entry_t entry)
51{
52	acl_t aclp;
53
54	aclp = (acl_t)(((long)entry >> _ACL_T_ALIGNMENT_BITS) << _ACL_T_ALIGNMENT_BITS);
55
56	return (aclp);
57}
58
59/*
60 * Return brand of an ACL.
61 */
62int
63_acl_brand(const acl_t acl)
64{
65
66	return (acl->ats_brand);
67}
68
69int
70_entry_brand(const acl_entry_t entry)
71{
72
73	return (_acl_brand(entry2acl(entry)));
74}
75
76/*
77 * Return 1, iff branding ACL as "brand" is ok.
78 */
79int
80_acl_brand_may_be(const acl_t acl, int brand)
81{
82
83	if (_acl_brand(acl) == ACL_BRAND_UNKNOWN)
84		return (1);
85
86	if (_acl_brand(acl) == brand)
87		return (1);
88
89	return (0);
90}
91
92int
93_entry_brand_may_be(const acl_entry_t entry, int brand)
94{
95
96	return (_acl_brand_may_be(entry2acl(entry), brand));
97}
98
99/*
100 * Brand ACL as "brand".
101 */
102void
103_acl_brand_as(acl_t acl, int brand)
104{
105
106	assert(_acl_brand_may_be(acl, brand));
107
108	acl->ats_brand = brand;
109}
110
111void
112_entry_brand_as(const acl_entry_t entry, int brand)
113{
114
115	_acl_brand_as(entry2acl(entry), brand);
116}
117
118int
119_acl_type_not_valid_for_acl(const acl_t acl, acl_type_t type)
120{
121
122	switch (_acl_brand(acl)) {
123	case ACL_BRAND_NFS4:
124		if (type == ACL_TYPE_NFS4)
125			return (0);
126		break;
127
128	case ACL_BRAND_POSIX:
129		if (type == ACL_TYPE_ACCESS || type == ACL_TYPE_DEFAULT)
130			return (0);
131		break;
132
133	case ACL_BRAND_UNKNOWN:
134		return (0);
135	}
136
137	return (-1);
138}
139
140void
141_acl_brand_from_type(acl_t acl, acl_type_t type)
142{
143
144	switch (type) {
145	case ACL_TYPE_NFS4:
146		_acl_brand_as(acl, ACL_BRAND_NFS4);
147		break;
148	case ACL_TYPE_ACCESS:
149	case ACL_TYPE_DEFAULT:
150		_acl_brand_as(acl, ACL_BRAND_POSIX);
151		break;
152	default:
153		/* XXX: What to do here? */
154		break;
155	}
156}
157
158int
159acl_get_brand_np(acl_t acl, int *brand_p)
160{
161
162	if (acl == NULL || brand_p == NULL) {
163		errno = EINVAL;
164		return (-1);
165	}
166	*brand_p = _acl_brand(acl);
167
168	return (0);
169}
170