xref: /freebsd/sys/security/mac/mac_label.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * Copyright (c) 2003-2004 Networks Associates Technology, Inc.
3  * Copyright (c) 2007 Robert N. M. Watson
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project in part by Network
7  * Associates Laboratories, the Security Research Division of Network
8  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
9  * as part of the DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 #include "opt_mac.h"
35 
36 #include <sys/param.h>
37 #include <sys/module.h>
38 #include <sys/sysctl.h>
39 #include <sys/systm.h>
40 
41 #include <vm/uma.h>
42 
43 #include <security/mac/mac_framework.h>
44 #include <security/mac/mac_internal.h>
45 #include <security/mac/mac_policy.h>
46 
47 /*
48  * zone_label is the UMA zone from which most labels are allocated.  Label
49  * structures are initialized to zero bytes so that policies see a NULL/0
50  * slot on first use, even if the policy is loaded after the label is
51  * allocated for an object.
52  */
53 static uma_zone_t	zone_label;
54 
55 static int	mac_labelzone_ctor(void *mem, int size, void *arg, int flags);
56 static void	mac_labelzone_dtor(void *mem, int size, void *arg);
57 
58 void
59 mac_labelzone_init(void)
60 {
61 
62 	zone_label = uma_zcreate("MAC labels", sizeof(struct label),
63 	    mac_labelzone_ctor, mac_labelzone_dtor, NULL, NULL,
64 	    UMA_ALIGN_PTR, 0);
65 }
66 
67 /*
68  * mac_init_label() and mac_destroy_label() are exported so that they can be
69  * used in mbuf tag initialization, where labels are not slab allocated from
70  * the zone_label zone.
71  */
72 void
73 mac_init_label(struct label *label)
74 {
75 
76 	bzero(label, sizeof(*label));
77 	label->l_flags = MAC_FLAG_INITIALIZED;
78 }
79 
80 void
81 mac_destroy_label(struct label *label)
82 {
83 
84 	KASSERT(label->l_flags & MAC_FLAG_INITIALIZED,
85 	    ("destroying uninitialized label"));
86 
87 #ifdef DIAGNOSTIC
88 	bzero(label, sizeof(*label));
89 #else
90 	label->l_flags &= ~MAC_FLAG_INITIALIZED;
91 #endif
92 }
93 
94 static int
95 mac_labelzone_ctor(void *mem, int size, void *arg, int flags)
96 {
97 	struct label *label;
98 
99 	KASSERT(size == sizeof(*label), ("mac_labelzone_ctor: wrong size\n"));
100 	label = mem;
101 	mac_init_label(label);
102 	return (0);
103 }
104 
105 static void
106 mac_labelzone_dtor(void *mem, int size, void *arg)
107 {
108 	struct label *label;
109 
110 	KASSERT(size == sizeof(*label), ("mac_labelzone_dtor: wrong size\n"));
111 	label = mem;
112 	mac_destroy_label(label);
113 }
114 
115 struct label *
116 mac_labelzone_alloc(int flags)
117 {
118 
119 	return (uma_zalloc(zone_label, flags));
120 }
121 
122 void
123 mac_labelzone_free(struct label *label)
124 {
125 
126 	uma_zfree(zone_label, label);
127 }
128 
129 /*
130  * Functions used by policy modules to get and set label values.
131  */
132 intptr_t
133 mac_label_get(struct label *l, int slot)
134 {
135 
136 	KASSERT(l != NULL, ("mac_label_get: NULL label"));
137 
138 	return (l->l_perpolicy[slot]);
139 }
140 
141 void
142 mac_label_set(struct label *l, int slot, intptr_t v)
143 {
144 
145 	KASSERT(l != NULL, ("mac_label_set: NULL label"));
146 
147 	l->l_perpolicy[slot] = v;
148 }
149