1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2001-2002 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 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 #include <sys/types.h>
31 #include "namespace.h"
32 #include <sys/acl.h>
33 #include "un-namespace.h"
34
35 #include <errno.h>
36 #include <stdio.h>
37
38 #include "acl_support.h"
39
40 /*
41 * acl_calc_mask() (23.4.2): calculate and set the permissions
42 * associated with the ACL_MASK ACL entry. If the ACL already
43 * contains an ACL_MASK entry, its permissions shall be
44 * overwritten; if not, one shall be added.
45 */
46 int
acl_calc_mask(acl_t * acl_p)47 acl_calc_mask(acl_t *acl_p)
48 {
49 struct acl *acl_int, *acl_int_new;
50 acl_t acl_new;
51 int i, mask_mode, mask_num;
52
53 /*
54 * (23.4.2.4) requires acl_p to point to a pointer to a valid ACL.
55 * Since one of the primary reasons to use this function would be
56 * to calculate the appropriate mask to obtain a valid ACL, we only
57 * perform sanity checks here and validate the ACL prior to
58 * returning.
59 */
60 if (acl_p == NULL || *acl_p == NULL) {
61 errno = EINVAL;
62 return (-1);
63 }
64
65 if (!_acl_brand_may_be(*acl_p, ACL_BRAND_POSIX)) {
66 errno = EINVAL;
67 return (-1);
68 }
69 _acl_brand_as(*acl_p, ACL_BRAND_POSIX);
70
71 acl_int = &(*acl_p)->ats_acl;
72 if ((acl_int->acl_cnt < 3) || (acl_int->acl_cnt > ACL_MAX_ENTRIES)) {
73 errno = EINVAL;
74 return (-1);
75 }
76
77 acl_new = acl_dup(*acl_p);
78 if (acl_new == NULL)
79 return (-1);
80 acl_int_new = &acl_new->ats_acl;
81
82 mask_mode = 0;
83 mask_num = -1;
84
85 /* gather permissions and find a mask entry */
86 for (i = 0; i < acl_int_new->acl_cnt; i++) {
87 switch(acl_int_new->acl_entry[i].ae_tag) {
88 case ACL_USER:
89 case ACL_GROUP:
90 case ACL_GROUP_OBJ:
91 mask_mode |=
92 acl_int_new->acl_entry[i].ae_perm & ACL_PERM_BITS;
93 break;
94 case ACL_MASK:
95 mask_num = i;
96 break;
97 }
98 }
99
100 /* if a mask entry already exists, overwrite the perms */
101 if (mask_num != -1)
102 acl_int_new->acl_entry[mask_num].ae_perm = mask_mode;
103 else {
104 /* if no mask exists, check acl_cnt... */
105 if (acl_int_new->acl_cnt == ACL_MAX_ENTRIES) {
106 errno = ENOMEM;
107 acl_free(acl_new);
108 return (-1);
109 }
110 /* ...and add the mask entry */
111 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_tag = ACL_MASK;
112 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_id =
113 ACL_UNDEFINED_ID;
114 acl_int_new->acl_entry[acl_int_new->acl_cnt].ae_perm =
115 mask_mode;
116 acl_int_new->acl_cnt++;
117 }
118
119 if (acl_valid(acl_new) == -1) {
120 errno = EINVAL;
121 acl_free(acl_new);
122 return (-1);
123 }
124
125 **acl_p = *acl_new;
126 acl_free(acl_new);
127
128 return (0);
129 }
130