1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
|
/*-
* Copyright (c) 1999-2002 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2004 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin for the
* TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mac.h>
#include <sys/priv.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/mac_policy.h>
#include <net/bpfdesc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
/*
* XXXRW: struct ifnet locking is incomplete in the network code, so we use
* our own global mutex for struct ifnet. Non-ideal, but should help in the
* SMP environment.
*/
static struct mtx mac_ifnet_mtx;
MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
#define MAC_IFNET_LOCK(ifp) mtx_lock(&mac_ifnet_mtx)
#define MAC_IFNET_UNLOCK(ifp) mtx_unlock(&mac_ifnet_mtx)
/*
* XXXRW: In order to use the MAC label UMA zone for all label allocations,
* we simply store a pointer to a UMA-allocated label in the mbuf tag. This
* is inefficient and should likely change to using a label embedded in the
* tag.
*/
/*
* Retrieve the label associated with an mbuf by searching for the tag.
* Depending on the value of mac_labelmbufs, it's possible that a label will
* not be present, in which case NULL is returned. Policies must handle the
* possibility of an mbuf not having label storage if they do not enforce
* early loading.
*/
struct label *
mac_mbuf_to_label(struct mbuf *mbuf)
{
struct m_tag *tag;
struct label *label;
if (mbuf == NULL)
return (NULL);
tag = m_tag_find(mbuf, PACKET_TAG_MACLABEL, NULL);
if (tag == NULL)
return (NULL);
label = (struct label *)(tag+1);
return (label);
}
static struct label *
mac_bpfdesc_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_PERFORM(init_bpfdesc_label, label);
return (label);
}
void
mac_init_bpfdesc(struct bpf_d *bpf_d)
{
bpf_d->bd_label = mac_bpfdesc_label_alloc();
}
static struct label *
mac_ifnet_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_PERFORM(init_ifnet_label, label);
return (label);
}
void
mac_init_ifnet(struct ifnet *ifp)
{
ifp->if_label = mac_ifnet_label_alloc();
}
int
mac_init_mbuf_tag(struct m_tag *tag, int flag)
{
struct label *label;
int error;
label = (struct label *) (tag + 1);
mac_init_label(label);
MAC_CHECK(init_mbuf_label, label, flag);
if (error) {
MAC_PERFORM(destroy_mbuf_label, label);
mac_destroy_label(label);
}
return (error);
}
int
mac_init_mbuf(struct mbuf *m, int flag)
{
struct m_tag *tag;
int error;
M_ASSERTPKTHDR(m);
#ifndef MAC_ALWAYS_LABEL_MBUF
/*
* If conditionally allocating mbuf labels, don't allocate unless
* they are required.
*/
if (!mac_labelmbufs)
return (0);
#endif
tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
flag);
if (tag == NULL)
return (ENOMEM);
error = mac_init_mbuf_tag(tag, flag);
if (error) {
m_tag_free(tag);
return (error);
}
m_tag_prepend(m, tag);
return (0);
}
static void
mac_bpfdesc_label_free(struct label *label)
{
MAC_PERFORM(destroy_bpfdesc_label, label);
mac_labelzone_free(label);
}
void
mac_destroy_bpfdesc(struct bpf_d *bpf_d)
{
mac_bpfdesc_label_free(bpf_d->bd_label);
bpf_d->bd_label = NULL;
}
static void
mac_ifnet_label_free(struct label *label)
{
MAC_PERFORM(destroy_ifnet_label, label);
mac_labelzone_free(label);
}
void
mac_destroy_ifnet(struct ifnet *ifp)
{
mac_ifnet_label_free(ifp->if_label);
ifp->if_label = NULL;
}
void
mac_destroy_mbuf_tag(struct m_tag *tag)
{
struct label *label;
label = (struct label *)(tag+1);
MAC_PERFORM(destroy_mbuf_label, label);
mac_destroy_label(label);
}
/*
* mac_copy_mbuf_tag is called when an mbuf header is duplicated, in which
* case the labels must also be duplicated.
*/
void
mac_copy_mbuf_tag(struct m_tag *src, struct m_tag *dest)
{
struct label *src_label, *dest_label;
src_label = (struct label *)(src+1);
dest_label = (struct label *)(dest+1);
/*
* mac_init_mbuf_tag() is called on the target tag in m_tag_copy(),
* so we don't need to call it here.
*/
MAC_PERFORM(copy_mbuf_label, src_label, dest_label);
}
void
mac_copy_mbuf(struct mbuf *m_from, struct mbuf *m_to)
{
struct label *src_label, *dest_label;
src_label = mac_mbuf_to_label(m_from);
dest_label = mac_mbuf_to_label(m_to);
MAC_PERFORM(copy_mbuf_label, src_label, dest_label);
}
static void
mac_copy_ifnet_label(struct label *src, struct label *dest)
{
MAC_PERFORM(copy_ifnet_label, src, dest);
}
static int
mac_externalize_ifnet_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen)
{
int error;
MAC_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
return (error);
}
static int
mac_internalize_ifnet_label(struct label *label, char *string)
{
int error;
MAC_INTERNALIZE(ifnet, label, string);
return (error);
}
void
mac_create_ifnet(struct ifnet *ifnet)
{
MAC_IFNET_LOCK(ifnet);
MAC_PERFORM(create_ifnet, ifnet, ifnet->if_label);
MAC_IFNET_UNLOCK(ifnet);
}
void
mac_create_bpfdesc(struct ucred *cred, struct bpf_d *bpf_d)
{
MAC_PERFORM(create_bpfdesc, cred, bpf_d, bpf_d->bd_label);
}
void
mac_create_mbuf_from_bpfdesc(struct bpf_d *bpf_d, struct mbuf *mbuf)
{
struct label *label;
BPFD_LOCK_ASSERT(bpf_d);
label = mac_mbuf_to_label(mbuf);
MAC_PERFORM(create_mbuf_from_bpfdesc, bpf_d, bpf_d->bd_label, mbuf,
label);
}
void
mac_create_mbuf_linklayer(struct ifnet *ifnet, struct mbuf *mbuf)
{
struct label *label;
label = mac_mbuf_to_label(mbuf);
MAC_IFNET_LOCK(ifnet);
MAC_PERFORM(create_mbuf_linklayer, ifnet, ifnet->if_label, mbuf,
label);
MAC_IFNET_UNLOCK(ifnet);
}
void
mac_create_mbuf_from_ifnet(struct ifnet *ifnet, struct mbuf *mbuf)
{
struct label *label;
label = mac_mbuf_to_label(mbuf);
MAC_IFNET_LOCK(ifnet);
MAC_PERFORM(create_mbuf_from_ifnet, ifnet, ifnet->if_label, mbuf,
label);
MAC_IFNET_UNLOCK(ifnet);
}
void
mac_create_mbuf_multicast_encap(struct mbuf *oldmbuf, struct ifnet *ifnet,
struct mbuf *newmbuf)
{
struct label *oldmbuflabel, *newmbuflabel;
oldmbuflabel = mac_mbuf_to_label(oldmbuf);
newmbuflabel = mac_mbuf_to_label(newmbuf);
MAC_IFNET_LOCK(ifnet);
MAC_PERFORM(create_mbuf_multicast_encap, oldmbuf, oldmbuflabel,
ifnet, ifnet->if_label, newmbuf, newmbuflabel);
MAC_IFNET_UNLOCK(ifnet);
}
void
mac_create_mbuf_netlayer(struct mbuf *oldmbuf, struct mbuf *newmbuf)
{
struct label *oldmbuflabel, *newmbuflabel;
oldmbuflabel = mac_mbuf_to_label(oldmbuf);
newmbuflabel = mac_mbuf_to_label(newmbuf);
MAC_PERFORM(create_mbuf_netlayer, oldmbuf, oldmbuflabel, newmbuf,
newmbuflabel);
}
int
mac_check_bpfdesc_receive(struct bpf_d *bpf_d, struct ifnet *ifnet)
{
int error;
BPFD_LOCK_ASSERT(bpf_d);
MAC_IFNET_LOCK(ifnet);
MAC_CHECK(check_bpfdesc_receive, bpf_d, bpf_d->bd_label, ifnet,
ifnet->if_label);
MAC_IFNET_UNLOCK(ifnet);
return (error);
}
int
mac_check_ifnet_transmit(struct ifnet *ifnet, struct mbuf *mbuf)
{
struct label *label;
int error;
M_ASSERTPKTHDR(mbuf);
label = mac_mbuf_to_label(mbuf);
MAC_IFNET_LOCK(ifnet);
MAC_CHECK(check_ifnet_transmit, ifnet, ifnet->if_label, mbuf,
label);
MAC_IFNET_UNLOCK(ifnet);
return (error);
}
int
mac_ioctl_ifnet_get(struct ucred *cred, struct ifreq *ifr,
struct ifnet *ifnet)
{
char *elements, *buffer;
struct label *intlabel;
struct mac mac;
int error;
error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
intlabel = mac_ifnet_label_alloc();
MAC_IFNET_LOCK(ifnet);
mac_copy_ifnet_label(ifnet->if_label, intlabel);
MAC_IFNET_UNLOCK(ifnet);
error = mac_externalize_ifnet_label(intlabel, elements, buffer,
mac.m_buflen);
mac_ifnet_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
mac_ioctl_ifnet_set(struct ucred *cred, struct ifreq *ifr,
struct ifnet *ifnet)
{
struct label *intlabel;
struct mac mac;
char *buffer;
int error;
error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_ifnet_label_alloc();
error = mac_internalize_ifnet_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error) {
mac_ifnet_label_free(intlabel);
return (error);
}
/*
* XXX: Note that this is a redundant privilege check, since policies
* impose this check themselves if required by the policy
* Eventually, this should go away.
*/
error = priv_check_cred(cred, PRIV_NET_SETIFMAC, 0);
if (error) {
mac_ifnet_label_free(intlabel);
return (error);
}
MAC_IFNET_LOCK(ifnet);
MAC_CHECK(check_ifnet_relabel, cred, ifnet, ifnet->if_label,
intlabel);
if (error) {
MAC_IFNET_UNLOCK(ifnet);
mac_ifnet_label_free(intlabel);
return (error);
}
MAC_PERFORM(relabel_ifnet, cred, ifnet, ifnet->if_label, intlabel);
MAC_IFNET_UNLOCK(ifnet);
mac_ifnet_label_free(intlabel);
return (0);
}
|