xref: /freebsd/sys/security/mac/mac_posix_sem.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
1 /*-
2  * Copyright (c) 2003-2005 SPARTA, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project in part by Network
6  * Associates Laboratories, the Security Research Division of Network
7  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
8  * as part of the DARPA CHATS research program.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_mac.h"
36 #include "opt_posix.h"
37 
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mac.h>
42 #include <sys/module.h>
43 #include <sys/systm.h>
44 #include <sys/sysctl.h>
45 
46 #include <posix4/ksem.h>
47 
48 #include <sys/mac_policy.h>
49 
50 #include <security/mac/mac_internal.h>
51 
52 static int	mac_enforce_posix_sem = 1;
53 SYSCTL_INT(_security_mac, OID_AUTO, enforce_posix_sem, CTLFLAG_RW,
54     &mac_enforce_posix_sem, 0, "Enforce MAC policy on global POSIX semaphores");
55 TUNABLE_INT("security.mac.enforce_posix_sem", &mac_enforce_posix_sem);
56 
57 #ifdef MAC_DEBUG
58 static unsigned int nmacposixsems;
59 SYSCTL_UINT(_security_mac_debug_counters, OID_AUTO, posix_sems, CTLFLAG_RD,
60     &nmacposixsems, 0, "number of posix global semaphores inuse");
61 #endif
62 
63 static struct label *
64 mac_posix_sem_label_alloc(void)
65 {
66 	struct label *label;
67 
68 	label = mac_labelzone_alloc(M_WAITOK);
69 	MAC_PERFORM(init_posix_sem_label, label);
70 	MAC_DEBUG_COUNTER_INC(&nmacposixsems);
71 	return (label);
72 }
73 
74 void
75 mac_init_posix_sem(struct ksem *ksemptr)
76 {
77 
78 	ksemptr->ks_label = mac_posix_sem_label_alloc();
79 }
80 
81 static void
82 mac_posix_sem_label_free(struct label *label)
83 {
84 
85 	MAC_PERFORM(destroy_posix_sem_label, label);
86 	MAC_DEBUG_COUNTER_DEC(&nmacposixsems);
87 }
88 
89 void
90 mac_destroy_posix_sem(struct ksem *ksemptr)
91 {
92 
93 	mac_posix_sem_label_free(ksemptr->ks_label);
94 	ksemptr->ks_label = NULL;
95 }
96 
97 void
98 mac_create_posix_sem(struct ucred *cred, struct ksem *ksemptr)
99 {
100 
101 	MAC_PERFORM(create_posix_sem, cred, ksemptr, ksemptr->ks_label);
102 }
103 
104 int
105 mac_check_posix_sem_destroy(struct ucred *cred, struct ksem *ksemptr)
106 {
107 	int error;
108 
109 	if (!mac_enforce_posix_sem)
110 		return (0);
111 
112 	MAC_CHECK(check_posix_sem_destroy, cred, ksemptr, ksemptr->ks_label);
113 
114 	return(error);
115 }
116 
117 int
118 mac_check_posix_sem_open(struct ucred *cred, struct ksem *ksemptr)
119 {
120 	int error;
121 
122 	if (!mac_enforce_posix_sem)
123 		return (0);
124 
125 	MAC_CHECK(check_posix_sem_open, cred, ksemptr, ksemptr->ks_label);
126 
127 	return(error);
128 }
129 
130 int
131 mac_check_posix_sem_getvalue(struct ucred *cred, struct ksem *ksemptr)
132 {
133 	int error;
134 
135 	if (!mac_enforce_posix_sem)
136 		return (0);
137 
138 	MAC_CHECK(check_posix_sem_getvalue, cred, ksemptr,
139 	    ksemptr->ks_label);
140 
141 	return(error);
142 }
143 
144 int
145 mac_check_posix_sem_post(struct ucred *cred, struct ksem *ksemptr)
146 {
147 	int error;
148 
149 	if (!mac_enforce_posix_sem)
150 		return (0);
151 
152 	MAC_CHECK(check_posix_sem_post, cred, ksemptr, ksemptr->ks_label);
153 
154 	return(error);
155 }
156 
157 int
158 mac_check_posix_sem_unlink(struct ucred *cred, struct ksem *ksemptr)
159 {
160 	int error;
161 
162 	if (!mac_enforce_posix_sem)
163 		return (0);
164 
165 	MAC_CHECK(check_posix_sem_unlink, cred, ksemptr, ksemptr->ks_label);
166 
167 	return(error);
168 }
169 
170 int
171 mac_check_posix_sem_wait(struct ucred *cred, struct ksem *ksemptr)
172 {
173 	int error;
174 
175 	if (!mac_enforce_posix_sem)
176 		return (0);
177 
178 	MAC_CHECK(check_posix_sem_wait, cred, ksemptr, ksemptr->ks_label);
179 
180 	return(error);
181 }
182