xref: /freebsd/lib/libc/posix1e/acl_equiv_mode_np.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/errno.h>
36 #include <sys/stat.h>
37 #include <sys/acl.h>
38 
39 #include "acl_support.h"
40 
41 int
42 acl_equiv_mode_np(acl_t acl, mode_t *mode_p)
43 {
44 	mode_t ret_mode = 0;
45 
46 	if (acl == NULL) {
47 		errno = EINVAL;
48 		return (-1);
49 	}
50 
51 	/* Linux returns 0 for ACL returned by acl_init() */
52 	if (_acl_brand(acl) == ACL_BRAND_UNKNOWN && acl->ats_acl.acl_cnt == 0)
53 		return (0);
54 
55 	// TODO: Do we want to handle ACL_BRAND_NFS4 in this function? */
56 	if (_acl_brand(acl) != ACL_BRAND_POSIX)
57 		return (1);
58 
59 	for (int cur_entry = 0; cur_entry < acl->ats_acl.acl_cnt; cur_entry++) {
60 		acl_entry_t entry = &acl->ats_acl.acl_entry[cur_entry];
61 
62 		if ((entry->ae_perm & ACL_PERM_BITS) != entry->ae_perm)
63 			return (1);
64 
65 		switch (entry->ae_tag) {
66 		case ACL_USER_OBJ:
67 			if (entry->ae_perm & ACL_READ)
68 				ret_mode |= S_IRUSR;
69 			if (entry->ae_perm & ACL_WRITE)
70 				ret_mode |= S_IWUSR;
71 			if (entry->ae_perm & ACL_EXECUTE)
72 				ret_mode |= S_IXUSR;
73 			break;
74 		case ACL_GROUP_OBJ:
75 			if (entry->ae_perm & ACL_READ)
76 				ret_mode |= S_IRGRP;
77 			if (entry->ae_perm & ACL_WRITE)
78 				ret_mode |= S_IWGRP;
79 			if (entry->ae_perm & ACL_EXECUTE)
80 				ret_mode |= S_IXGRP;
81 			break;
82 		case ACL_OTHER:
83 			if (entry->ae_perm & ACL_READ)
84 				ret_mode |= S_IROTH;
85 			if (entry->ae_perm & ACL_WRITE)
86 				ret_mode |= S_IWOTH;
87 			if (entry->ae_perm & ACL_EXECUTE)
88 				ret_mode |= S_IXOTH;
89 			break;
90 		default:
91 			return (1);
92 		}
93 	}
94 
95 	if (mode_p != NULL)
96 		*mode_p = ret_mode;
97 
98 	return (0);
99 }
100