1 /*
2 * Copyright (c) 2010 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*-
29 * Copyright (c) 2006 nCircle Network Security, Inc.
30 * Copyright (c) 2009 Robert N. M. Watson
31 * All rights reserved.
32 *
33 * This software was developed by Robert N. M. Watson for the TrustedBSD
34 * Project under contract to nCircle Network Security, Inc.
35 *
36 * This software was developed at the University of Cambridge Computer
37 * Laboratory with support from a grant from Google, Inc.
38 *
39 * Redistribution and use in source and binary forms, with or without
40 * modification, are permitted provided that the following conditions
41 * are met:
42 * 1. Redistributions of source code must retain the above copyright
43 * notice, this list of conditions and the following disclaimer.
44 * 2. Redistributions in binary form must reproduce the above copyright
45 * notice, this list of conditions and the following disclaimer in the
46 * documentation and/or other materials provided with the distribution.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
52 * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
53 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
54 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
55 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
56 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
57 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
58 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59 */
60
61 /*
62 * MAC checks for system privileges.
63 */
64
65 #include <sys/param.h>
66 #include <sys/kernel.h>
67
68 #include <security/mac_internal.h>
69
70 /*
71 * The MAC Framework interacts with kernel privilege checks in two ways: it
72 * may restrict the granting of privilege to a subject, and it may grant
73 * additional privileges to the subject. Policies may implement none, one,
74 * or both of these entry points. Restriction of privilege by any policy
75 * always overrides granting of privilege by any policy or other privilege
76 * mechanism. See kern_priv.c:priv_check_cred() for details of the
77 * composition.
78 */
79
80 /*
81 * Restrict access to a privilege for a credential. Return failure if any
82 * policy denies access.
83 */
84 int
mac_priv_check(kauth_cred_t cred,int priv)85 mac_priv_check(kauth_cred_t cred, int priv)
86 {
87 int error;
88
89 if (!mac_cred_check_enforce(cred)) {
90 return 0;
91 }
92
93 MAC_CHECK(priv_check, cred, priv);
94
95 return error;
96 }
97
98 /*
99 * Grant access to a privilege for a credential. Return success if any
100 * policy grants access.
101 */
102 int
mac_priv_grant(kauth_cred_t cred,int priv)103 mac_priv_grant(kauth_cred_t cred, int priv)
104 {
105 int error;
106
107 if (!mac_cred_check_enforce(cred)) {
108 return 0;
109 }
110
111 MAC_GRANT(priv_grant, cred, priv);
112
113 return error;
114 }
115