mac_partition.c revision 106648 
1/*-
2 * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
3 * Copyright (c) 2001, 2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed by Robert Watson for the TrustedBSD Project.
7 *
8 * This software was developed for the FreeBSD Project in part by Network
9 * Associates Laboratories, the Security Research Division of Network
10 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
11 * as part of the DARPA CHATS research program.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $FreeBSD: head/sys/security/mac_partition/mac_partition.c 106648 2002-11-08 18:04:36Z rwatson $
35 */
36
37/*
38 * Developed by the TrustedBSD Project.
39 * Experiment with a partition-like model.
40 */
41
42#include <sys/types.h>
43#include <sys/param.h>
44#include <sys/conf.h>
45#include <sys/kernel.h>
46#include <sys/mac.h>
47#include <sys/mount.h>
48#include <sys/proc.h>
49#include <sys/systm.h>
50#include <sys/sysproto.h>
51#include <sys/sysent.h>
52#include <sys/vnode.h>
53#include <sys/file.h>
54#include <sys/socket.h>
55#include <sys/socketvar.h>
56#include <sys/sysctl.h>
57
58#include <fs/devfs/devfs.h>
59
60#include <net/bpfdesc.h>
61#include <net/if.h>
62#include <net/if_types.h>
63#include <net/if_var.h>
64
65#include <vm/vm.h>
66
67#include <sys/mac_policy.h>
68
69#include <security/mac_partition/mac_partition.h>
70
71SYSCTL_DECL(_security_mac);
72
73SYSCTL_NODE(_security_mac, OID_AUTO, partition, CTLFLAG_RW, 0,
74    "TrustedBSD mac_partition policy controls");
75
76static int	mac_partition_enabled = 1;
77SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW,
78    &mac_partition_enabled, 0, "Enforce partition policy");
79
80static int	partition_slot;
81#define	SLOT(l)	(LABEL_TO_SLOT((l), partition_slot).l_long)
82
83static void
84mac_partition_init(struct mac_policy_conf *conf)
85{
86
87}
88
89static void
90mac_partition_init_label(struct label *label)
91{
92
93	SLOT(label) = 0;
94}
95
96static void
97mac_partition_destroy_label(struct label *label)
98{
99
100	SLOT(label) = 0;
101}
102
103static int
104mac_partition_externalize_label(struct label *label, char *element_name,
105    char *element_data, size_t size, size_t *len, int *claimed)
106{
107
108	if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
109		return (0);
110
111	(*claimed)++;
112	*len = snprintf(element_data, size, "%ld", SLOT(label));
113	return (0);
114}
115
116static int
117mac_partition_internalize_label(struct label *label, char *element_name,
118    char *element_data, int *claimed)
119{
120
121	if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
122		return (0);
123
124	(*claimed)++;
125	SLOT(label) = strtol(element_data, NULL, 10);
126	return (0);
127}
128
129static void
130mac_partition_create_cred(struct ucred *cred_parent, struct ucred *cred_child)
131{
132
133	SLOT(&cred_child->cr_label) = SLOT(&cred_parent->cr_label);
134}
135
136static void
137mac_partition_create_proc0(struct ucred *cred)
138{
139
140	SLOT(&cred->cr_label) = 0;
141}
142
143static void
144mac_partition_create_proc1(struct ucred *cred)
145{
146
147	SLOT(&cred->cr_label) = 0;
148}
149
150static void
151mac_partition_relabel_cred(struct ucred *cred, struct label *newlabel)
152{
153
154	if (SLOT(newlabel) != 0)
155		SLOT(&cred->cr_label) = SLOT(newlabel);
156}
157
158static int
159label_on_label(struct label *subject, struct label *object)
160{
161
162	if (mac_partition_enabled == 0)
163		return (0);
164
165	if (SLOT(subject) == 0)
166		return (0);
167
168	if (SLOT(subject) == SLOT(object))
169		return (0);
170
171	return (EPERM);
172}
173
174static int
175mac_partition_check_cred_relabel(struct ucred *cred, struct label *newlabel)
176{
177	int error;
178
179	error = 0;
180
181	/* Treat "0" as a no-op request. */
182	if (SLOT(newlabel) != 0) {
183		/*
184		 * Require BSD privilege in order to change the partition.
185		 * Originally we also required that the process not be
186		 * in a partition in the first place, but this didn't
187		 * interact well with sendmail.
188		 */
189		error = suser_cred(cred, 0);
190	}
191
192	return (error);
193}
194
195static int
196mac_partition_check_cred_visible(struct ucred *u1, struct ucred *u2)
197{
198	int error;
199
200	error = label_on_label(&u1->cr_label, &u2->cr_label);
201
202	return (error == 0 ? 0 : ESRCH);
203}
204
205static int
206mac_partition_check_proc_debug(struct ucred *cred, struct proc *proc)
207{
208	int error;
209
210	error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
211
212	return (error ? ESRCH : 0);
213}
214
215static int
216mac_partition_check_proc_sched(struct ucred *cred, struct proc *proc)
217{
218	int error;
219
220	error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
221
222	return (error ? ESRCH : 0);
223}
224
225static int
226mac_partition_check_proc_signal(struct ucred *cred, struct proc *proc,
227    int signum)
228{
229	int error;
230
231	error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
232
233	return (error ? ESRCH : 0);
234}
235
236static int
237mac_partition_check_socket_visible(struct ucred *cred, struct socket *socket,
238    struct label *socketlabel)
239{
240	int error;
241
242	error = label_on_label(&cred->cr_label, socketlabel);
243
244	return (error ? ENOENT : 0);
245}
246
247static int
248mac_partition_check_vnode_exec(struct ucred *cred, struct vnode *vp,
249    struct label *label, struct image_params *imgp, struct label *execlabel)
250{
251
252	if (execlabel != NULL) {
253		/*
254		 * We currently don't permit labels to be changed at
255		 * exec-time as part of the partition model, so disallow
256		 * non-NULL partition label changes in execlabel.
257		 */
258		if (SLOT(execlabel) != 0)
259			return (EINVAL);
260	}
261
262	return (0);
263}
264
265static struct mac_policy_ops mac_partition_ops =
266{
267	.mpo_init = mac_partition_init,
268	.mpo_init_cred_label = mac_partition_init_label,
269	.mpo_destroy_cred_label = mac_partition_destroy_label,
270	.mpo_externalize_cred_label = mac_partition_externalize_label,
271	.mpo_internalize_cred_label = mac_partition_internalize_label,
272	.mpo_create_cred = mac_partition_create_cred,
273	.mpo_create_proc0 = mac_partition_create_proc0,
274	.mpo_create_proc1 = mac_partition_create_proc1,
275	.mpo_relabel_cred = mac_partition_relabel_cred,
276	.mpo_check_cred_relabel = mac_partition_check_cred_relabel,
277	.mpo_check_cred_visible = mac_partition_check_cred_visible,
278	.mpo_check_proc_debug = mac_partition_check_proc_debug,
279	.mpo_check_proc_sched = mac_partition_check_proc_sched,
280	.mpo_check_proc_signal = mac_partition_check_proc_signal,
281	.mpo_check_socket_visible = mac_partition_check_socket_visible,
282	.mpo_check_vnode_exec = mac_partition_check_vnode_exec,
283};
284
285MAC_POLICY_SET(&mac_partition_ops, trustedbsd_mac_partition,
286    "TrustedBSD MAC/Partition", MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot);
287