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