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__FBSDID("$FreeBSD$");
40
41#include "opt_kdtrace.h"
42#include "opt_mac.h"
43
44#include <sys/param.h>
45#include <sys/kernel.h>
46#include <sys/priv.h>
47#include <sys/sdt.h>
48#include <sys/module.h>
49
50#include <security/mac/mac_framework.h>
51#include <security/mac/mac_internal.h>
52#include <security/mac/mac_policy.h>
53
54/*
55 * The MAC Framework interacts with kernel privilege checks in two ways: it
56 * may restrict the granting of privilege to a subject, and it may grant
57 * additional privileges to the subject.  Policies may implement none, one,
58 * or both of these entry points.  Restriction of privilege by any policy
59 * always overrides granting of privilege by any policy or other privilege
60 * mechanism.  See kern_priv.c:priv_check_cred() for details of the
61 * composition.
62 */
63
64MAC_CHECK_PROBE_DEFINE2(priv_check, "struct ucred *", "int");
65
66/*
67 * Restrict access to a privilege for a credential.  Return failure if any
68 * policy denies access.
69 */
70int
71mac_priv_check(struct ucred *cred, int priv)
72{
73	int error;
74
75	MAC_POLICY_CHECK_NOSLEEP(priv_check, cred, priv);
76	MAC_CHECK_PROBE2(priv_check, error, cred, priv);
77
78	return (error);
79}
80
81MAC_GRANT_PROBE_DEFINE2(priv_grant, "struct ucred *", "int");
82
83/*
84 * Grant access to a privilege for a credential.  Return success if any
85 * policy grants access.
86 */
87int
88mac_priv_grant(struct ucred *cred, int priv)
89{
90	int error;
91
92	MAC_POLICY_GRANT_NOSLEEP(priv_grant, cred, priv);
93	MAC_GRANT_PROBE2(priv_grant, error, cred, priv);
94
95	return (error);
96}
97