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 | * Redistribution and use in source and binary forms, with or without |
37 | * modification, are permitted provided that the following conditions |
38 | * are met: |
39 | * 1. Redistributions of source code must retain the above copyright |
40 | * notice, this list of conditions and the following disclaimer. |
41 | * 2. Redistributions in binary form must reproduce the above copyright |
42 | * notice, this list of conditions and the following disclaimer in the |
43 | * documentation and/or other materials provided with the distribution. |
44 | * |
45 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
46 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
47 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
48 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY, |
49 | * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
50 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED |
51 | * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
52 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
53 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
54 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
55 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
56 | */ |
57 | |
58 | #include <sys/cdefs.h> |
59 | |
60 | #include <sys/param.h> |
61 | #include <sys/kernel.h> |
62 | #include <sys/priv.h> |
63 | #include <sys/proc.h> |
64 | #include <sys/systm.h> |
65 | #include <sys/kauth.h> |
66 | |
67 | #if CONFIG_MACF |
68 | #include <security/mac_framework.h> |
69 | #endif |
70 | |
71 | int proc_check_footprint_priv(void); |
72 | |
73 | /* |
74 | * Check a credential for privilege. Lots of good reasons to deny privilege; |
75 | * only a few to grant it. |
76 | */ |
77 | int |
78 | priv_check_cred(kauth_cred_t cred, int priv, int flags) |
79 | { |
80 | #if !CONFIG_MACF |
81 | #pragma unused(priv) |
82 | #endif |
83 | int error; |
84 | |
85 | /* |
86 | * We first evaluate policies that may deny the granting of |
87 | * privilege unilaterally. |
88 | */ |
89 | #if CONFIG_MACF |
90 | error = mac_priv_check(cred, priv); |
91 | if (error) { |
92 | goto out; |
93 | } |
94 | #endif |
95 | |
96 | /* Only grant all privileges to root if DEFAULT_UNPRIVELEGED flag is NOT set. */ |
97 | if (!(flags & PRIVCHECK_DEFAULT_UNPRIVILEGED_FLAG)) { |
98 | /* |
99 | * Having determined if privilege is restricted by various policies, |
100 | * now determine if privilege is granted. At this point, any policy |
101 | * may grant privilege. For now, we allow short-circuit boolean |
102 | * evaluation, so may not call all policies. Perhaps we should. |
103 | */ |
104 | if (kauth_cred_getuid(cred: cred) == 0) { |
105 | error = 0; |
106 | goto out; |
107 | } |
108 | } |
109 | |
110 | /* |
111 | * Now check with MAC, if enabled, to see if a policy module grants |
112 | * privilege. |
113 | */ |
114 | #if CONFIG_MACF |
115 | if (mac_priv_grant(cred, priv) == 0) { |
116 | error = 0; |
117 | goto out; |
118 | } |
119 | #endif |
120 | |
121 | /* |
122 | * The default is deny, so if no policies have granted it, reject |
123 | * with a privilege error here. |
124 | */ |
125 | error = EPERM; |
126 | out: |
127 | return error; |
128 | } |
129 | |
130 | int |
131 | (void) |
132 | { |
133 | return priv_check_cred(cred: kauth_cred_get(), PRIV_VM_FOOTPRINT_LIMIT, flags: 0); |
134 | } |
135 | |