1 /*-
2 * Copyright (c) 2006 nCircle Network Security, Inc.
3 * Copyright (c) 2009 Robert N. M. Watson
4 * All rights reserved.
5 *
6 * This software was developed by Robert N. M. Watson for the TrustedBSD
7 * Project under contract to nCircle Network Security, Inc.
8 *
9 * This software was developed at the University of Cambridge Computer
10 * Laboratory with support from a grant from Google, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
25 * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
27 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 /*
35 * MAC checks for system privileges.
36 */
37
38 #include "sys/cdefs.h"
39 #include "opt_mac.h"
40
41 #include <sys/param.h>
42 #include <sys/kernel.h>
43 #include <sys/priv.h>
44 #include <sys/sdt.h>
45 #include <sys/module.h>
46
47 #include <security/mac/mac_framework.h>
48 #include <security/mac/mac_internal.h>
49 #include <security/mac/mac_policy.h>
50
51 /*
52 * The MAC Framework interacts with kernel privilege checks in two ways: it
53 * may restrict the granting of privilege to a subject, and it may grant
54 * additional privileges to the subject. Policies may implement none, one,
55 * or both of these entry points. Restriction of privilege by any policy
56 * always overrides granting of privilege by any policy or other privilege
57 * mechanism. See kern_priv.c:priv_check_cred() for details of the
58 * composition.
59 */
60
61 MAC_CHECK_PROBE_DEFINE2(priv_check, "struct ucred *", "int");
62
63 /*
64 * Restrict access to a privilege for a credential. Return failure if any
65 * policy denies access.
66 */
67 int
mac_priv_check_impl(struct ucred * cred,int priv)68 mac_priv_check_impl(struct ucred *cred, int priv)
69 {
70 int error;
71
72 MAC_POLICY_CHECK_NOSLEEP(priv_check, cred, priv);
73 MAC_CHECK_PROBE2(priv_check, error, cred, priv);
74
75 return (error);
76 }
77
78 MAC_GRANT_PROBE_DEFINE2(priv_grant, "struct ucred *", "int");
79
80 /*
81 * Grant access to a privilege for a credential. Return success if any
82 * policy grants access.
83 */
84 int
mac_priv_grant_impl(struct ucred * cred,int priv)85 mac_priv_grant_impl(struct ucred *cred, int priv)
86 {
87 int error;
88
89 MAC_POLICY_GRANT_NOSLEEP(priv_grant, cred, priv);
90 MAC_GRANT_PROBE2(priv_grant, error, cred, priv);
91
92 return (error);
93 }
94