xref: /freebsd/lib/libc/posix1e/acl_equiv_mode_np.c (revision 5c8e8e82aeaf3aa788acdd6cfca30ef09094230d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 Gleb Popov
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  * acl_equiv_mode_np: Check if an ACL can be represented as a mode_t.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/errno.h>
38 #include <sys/stat.h>
39 #include <sys/acl.h>
40 
41 #include "acl_support.h"
42 
43 int
44 acl_equiv_mode_np(acl_t acl, mode_t *mode_p)
45 {
46 	mode_t ret_mode = 0;
47 
48 	if (acl == NULL) {
49 		errno = EINVAL;
50 		return (-1);
51 	}
52 
53 	/* Linux returns 0 for ACL returned by acl_init() */
54 	if (_acl_brand(acl) == ACL_BRAND_UNKNOWN && acl->ats_acl.acl_cnt == 0)
55 		return (0);
56 
57 	// TODO: Do we want to handle ACL_BRAND_NFS4 in this function? */
58 	if (_acl_brand(acl) != ACL_BRAND_POSIX)
59 		return (1);
60 
61 	for (int cur_entry = 0; cur_entry < acl->ats_acl.acl_cnt; cur_entry++) {
62 		acl_entry_t entry = &acl->ats_acl.acl_entry[cur_entry];
63 
64 		if ((entry->ae_perm & ACL_PERM_BITS) != entry->ae_perm)
65 			return (1);
66 
67 		switch (entry->ae_tag) {
68 		case ACL_USER_OBJ:
69 			if (entry->ae_perm & ACL_READ)
70 				ret_mode |= S_IRUSR;
71 			if (entry->ae_perm & ACL_WRITE)
72 				ret_mode |= S_IWUSR;
73 			if (entry->ae_perm & ACL_EXECUTE)
74 				ret_mode |= S_IXUSR;
75 			break;
76 		case ACL_GROUP_OBJ:
77 			if (entry->ae_perm & ACL_READ)
78 				ret_mode |= S_IRGRP;
79 			if (entry->ae_perm & ACL_WRITE)
80 				ret_mode |= S_IWGRP;
81 			if (entry->ae_perm & ACL_EXECUTE)
82 				ret_mode |= S_IXGRP;
83 			break;
84 		case ACL_OTHER:
85 			if (entry->ae_perm & ACL_READ)
86 				ret_mode |= S_IROTH;
87 			if (entry->ae_perm & ACL_WRITE)
88 				ret_mode |= S_IWOTH;
89 			if (entry->ae_perm & ACL_EXECUTE)
90 				ret_mode |= S_IXOTH;
91 			break;
92 		default:
93 			return (1);
94 		}
95 	}
96 
97 	if (mode_p != NULL)
98 		*mode_p = ret_mode;
99 
100 	return (0);
101 }
102