1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2001 Chris D. Faulhaber
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 <errno.h>
30 #include <stdio.h>
31 #include <assert.h>
32 #include <sys/acl.h>
33 #include <sys/stat.h>
34
35 #include "acl_support.h"
36
37 /*
38 * These routines from sys/kern/subr_acl_nfs4.c are used by both kernel
39 * and libc.
40 */
41 void acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp);
42 void acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int file_owner_id,
43 int canonical_six);
44
45 static acl_t
_nfs4_acl_strip_np(const acl_t aclp,int canonical_six)46 _nfs4_acl_strip_np(const acl_t aclp, int canonical_six)
47 {
48 acl_t newacl;
49 mode_t mode = 0;
50
51 newacl = acl_init(ACL_MAX_ENTRIES);
52 if (newacl == NULL) {
53 errno = ENOMEM;
54 return (NULL);
55 }
56
57 _acl_brand_as(newacl, ACL_BRAND_NFS4);
58
59 acl_nfs4_sync_mode_from_acl(&mode, &(aclp->ats_acl));
60 acl_nfs4_trivial_from_mode_libc(&(newacl->ats_acl), mode, canonical_six);
61
62 return (newacl);
63 }
64
65 static acl_t
_posix1e_acl_strip_np(const acl_t aclp,int recalculate_mask)66 _posix1e_acl_strip_np(const acl_t aclp, int recalculate_mask)
67 {
68 acl_t acl_new, acl_old;
69 acl_entry_t entry, entry_new;
70 acl_tag_t tag;
71 int entry_id, have_mask_entry;
72
73 assert(_acl_brand(aclp) == ACL_BRAND_POSIX);
74
75 acl_old = acl_dup(aclp);
76 if (acl_old == NULL)
77 return (NULL);
78
79 assert(_acl_brand(acl_old) == ACL_BRAND_POSIX);
80
81 have_mask_entry = 0;
82 acl_new = acl_init(ACL_MAX_ENTRIES);
83 if (acl_new == NULL) {
84 acl_free(acl_old);
85 return (NULL);
86 }
87 tag = ACL_UNDEFINED_TAG;
88
89 /* only save the default user/group/other entries */
90 entry_id = ACL_FIRST_ENTRY;
91 while (acl_get_entry(acl_old, entry_id, &entry) == 1) {
92 entry_id = ACL_NEXT_ENTRY;
93
94 assert(_entry_brand(entry) == ACL_BRAND_POSIX);
95
96 if (acl_get_tag_type(entry, &tag) == -1)
97 goto fail;
98
99 switch(tag) {
100 case ACL_USER_OBJ:
101 case ACL_GROUP_OBJ:
102 case ACL_OTHER:
103 if (acl_create_entry(&acl_new, &entry_new) == -1)
104 goto fail;
105 if (acl_copy_entry(entry_new, entry) == -1)
106 goto fail;
107 assert(_entry_brand(entry_new) == ACL_BRAND_POSIX);
108 break;
109 case ACL_MASK:
110 have_mask_entry = 1;
111 break;
112 default:
113 break;
114 }
115 }
116
117 assert(_acl_brand(acl_new) == ACL_BRAND_POSIX);
118
119 if (have_mask_entry && recalculate_mask) {
120 if (acl_calc_mask(&acl_new) == -1)
121 goto fail;
122 }
123
124 return (acl_new);
125
126 fail:
127 acl_free(acl_new);
128 acl_free(acl_old);
129
130 return (NULL);
131 }
132
133 acl_t
acl_strip_np(const acl_t aclp,int recalculate_mask)134 acl_strip_np(const acl_t aclp, int recalculate_mask)
135 {
136 switch (_acl_brand(aclp)) {
137 case ACL_BRAND_NFS4:
138 return (_nfs4_acl_strip_np(aclp, 0));
139
140 case ACL_BRAND_POSIX:
141 return (_posix1e_acl_strip_np(aclp, recalculate_mask));
142
143 default:
144 errno = EINVAL;
145 return (NULL);
146 }
147 }
148
149 /*
150 * Return 1, if ACL is trivial, 0 otherwise.
151 *
152 * ACL is trivial, iff its meaning could be fully expressed using just file
153 * mode. In other words, ACL is trivial iff it doesn't have "+" to the right
154 * of the mode bits in "ls -l" output ;-)
155 */
156 int
acl_is_trivial_np(const acl_t aclp,int * trivialp)157 acl_is_trivial_np(const acl_t aclp, int *trivialp)
158 {
159 acl_t tmpacl;
160 int differs;
161
162 if (aclp == NULL || trivialp == NULL) {
163 errno = EINVAL;
164 return (-1);
165 }
166
167 switch (_acl_brand(aclp)) {
168 case ACL_BRAND_POSIX:
169 if (aclp->ats_acl.acl_cnt == 3)
170 *trivialp = 1;
171 else
172 *trivialp = 0;
173
174 return (0);
175
176 case ACL_BRAND_NFS4:
177 /*
178 * If the ACL has more than canonical six entries,
179 * it's non trivial by definition.
180 */
181 if (aclp->ats_acl.acl_cnt > 6) {
182 *trivialp = 0;
183 return (0);
184 }
185
186 /*
187 * Calculate trivial ACL - using acl_strip_np(3) - and compare
188 * with the original.
189 */
190 tmpacl = _nfs4_acl_strip_np(aclp, 0);
191 if (tmpacl == NULL)
192 return (-1);
193
194 differs = _acl_differs(aclp, tmpacl);
195 acl_free(tmpacl);
196
197 if (differs == 0) {
198 *trivialp = 1;
199 return (0);
200 }
201
202 /*
203 * Try again with an old-style, "canonical six" trivial ACL.
204 */
205 tmpacl = _nfs4_acl_strip_np(aclp, 1);
206 if (tmpacl == NULL)
207 return (-1);
208
209 differs = _acl_differs(aclp, tmpacl);
210 acl_free(tmpacl);
211
212 if (differs)
213 *trivialp = 0;
214 else
215 *trivialp = 1;
216
217 return (0);
218
219 default:
220 errno = EINVAL;
221 return (-1);
222 }
223 }
224