1 /*-
2 * Copyright (c) 1999-2002, 2009, 2019 Robert N. M. Watson
3 * Copyright (c) 2001 Ilmar S. Habibulin
4 * Copyright (c) 2001-2004 Networks Associates Technology, Inc.
5 * Copyright (c) 2006 SPARTA, Inc.
6 * Copyright (c) 2008 Apple Inc.
7 * All rights reserved.
8 *
9 * This software was developed by Robert Watson and Ilmar Habibulin for the
10 * TrustedBSD Project.
11 *
12 * This software was enhanced by SPARTA ISSO under SPAWAR contract
13 * N66001-04-C-6019 ("SEFOS").
14 *
15 * This software was developed for the FreeBSD Project in part by Network
16 * Associates Laboratories, the Security Research Division of Network
17 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
18 * as part of the DARPA CHATS research program.
19 *
20 * This software was developed at the University of Cambridge Computer
21 * Laboratory with support from a grant from Google, Inc.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the above copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * SUCH DAMAGE.
43 */
44
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47
48 #include "opt_mac.h"
49
50 #include <sys/param.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mutex.h>
55 #include <sys/mac.h>
56 #include <sys/priv.h>
57 #include <sys/sbuf.h>
58 #include <sys/sdt.h>
59 #include <sys/systm.h>
60 #include <sys/mount.h>
61 #include <sys/file.h>
62 #include <sys/namei.h>
63 #include <sys/protosw.h>
64 #include <sys/socket.h>
65 #include <sys/socketvar.h>
66 #include <sys/sysctl.h>
67
68 #include <net/bpfdesc.h>
69 #include <net/if.h>
70 #include <net/if_var.h>
71
72 #include <security/mac/mac_framework.h>
73 #include <security/mac/mac_internal.h>
74 #include <security/mac/mac_policy.h>
75
76 /*
77 * XXXRW: struct ifnet locking is incomplete in the network code, so we use
78 * our own global mutex for struct ifnet. Non-ideal, but should help in the
79 * SMP environment.
80 *
81 * This lock is acquired only if a loaded policy is using ifnet labeling.
82 * This should not ever change during a MAC policy check, itself, but could
83 * change during setup/return from a check, so we have to condition unlock on
84 * previous lock.
85 */
86 struct mtx mac_ifnet_mtx;
87 MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
88
89 /*
90 * Retrieve the label associated with an mbuf by searching for the tag.
91 * Depending on the value of mac_labelmbufs, it's possible that a label will
92 * not be present, in which case NULL is returned. Policies must handle the
93 * possibility of an mbuf not having label storage if they do not enforce
94 * early loading.
95 */
96 struct label *
97 mac_mbuf_to_label(struct mbuf *m)
98 {
99 struct m_tag *tag;
100 struct label *label;
101
102 if (m == NULL)
103 return (NULL);
104 tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL);
105 if (tag == NULL)
106 return (NULL);
107 label = (struct label *)(tag+1);
108 return (label);
109 }
110
111 static struct label *
112 mac_bpfdesc_label_alloc(void)
113 {
114 struct label *label;
115
116 label = mac_labelzone_alloc(M_WAITOK);
117 MAC_POLICY_PERFORM(bpfdesc_init_label, label);
118 return (label);
119 }
120
121 void
122 mac_bpfdesc_init(struct bpf_d *d)
123 {
124
125 if (mac_labeled & MPC_OBJECT_BPFDESC)
126 d->bd_label = mac_bpfdesc_label_alloc();
127 else
128 d->bd_label = NULL;
129 }
130
131 static struct label *
132 mac_ifnet_label_alloc(void)
133 {
134 struct label *label;
135
136 label = mac_labelzone_alloc(M_WAITOK);
137 MAC_POLICY_PERFORM(ifnet_init_label, label);
138 return (label);
139 }
140
141 void
142 mac_ifnet_init(struct ifnet *ifp)
143 {
144
145 if (mac_labeled & MPC_OBJECT_IFNET)
146 ifp->if_label = mac_ifnet_label_alloc();
147 else
148 ifp->if_label = NULL;
149 }
150
151 int
152 mac_mbuf_tag_init(struct m_tag *tag, int flag)
153 {
154 struct label *label;
155 int error;
156
157 label = (struct label *) (tag + 1);
158 mac_init_label(label);
159
160 if (flag & M_WAITOK)
161 MAC_POLICY_CHECK(mbuf_init_label, label, flag);
162 else
163 MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag);
164 if (error) {
165 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
166 mac_destroy_label(label);
167 }
168 return (error);
169 }
170
171 int
172 mac_mbuf_init(struct mbuf *m, int flag)
173 {
174 struct m_tag *tag;
175 int error;
176
177 M_ASSERTPKTHDR(m);
178
179 if (mac_labeled & MPC_OBJECT_MBUF) {
180 tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
181 flag);
182 if (tag == NULL)
183 return (ENOMEM);
184 error = mac_mbuf_tag_init(tag, flag);
185 if (error) {
186 m_tag_free(tag);
187 return (error);
188 }
189 m_tag_prepend(m, tag);
190 }
191 return (0);
192 }
193
194 static void
195 mac_bpfdesc_label_free(struct label *label)
196 {
197
198 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label);
199 mac_labelzone_free(label);
200 }
201
202 void
203 mac_bpfdesc_destroy(struct bpf_d *d)
204 {
205
206 if (d->bd_label != NULL) {
207 mac_bpfdesc_label_free(d->bd_label);
208 d->bd_label = NULL;
209 }
210 }
211
212 static void
213 mac_ifnet_label_free(struct label *label)
214 {
215
216 MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label);
217 mac_labelzone_free(label);
218 }
219
220 void
221 mac_ifnet_destroy(struct ifnet *ifp)
222 {
223
224 if (ifp->if_label != NULL) {
225 mac_ifnet_label_free(ifp->if_label);
226 ifp->if_label = NULL;
227 }
228 }
229
230 void
231 mac_mbuf_tag_destroy(struct m_tag *tag)
232 {
233 struct label *label;
234
235 label = (struct label *)(tag+1);
236
237 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
238 mac_destroy_label(label);
239 }
240
241 /*
242 * mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which
243 * case the labels must also be duplicated.
244 */
245 void
246 mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest)
247 {
248 struct label *src_label, *dest_label;
249
250 src_label = (struct label *)(src+1);
251 dest_label = (struct label *)(dest+1);
252
253 /*
254 * mac_mbuf_tag_init() is called on the target tag in m_tag_copy(),
255 * so we don't need to call it here.
256 */
257 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
258 }
259
260 void
261 mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to)
262 {
263 struct label *src_label, *dest_label;
264
265 if (mac_policy_count == 0)
266 return;
267
268 src_label = mac_mbuf_to_label(m_from);
269 dest_label = mac_mbuf_to_label(m_to);
270
271 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
272 }
273
274 static void
275 mac_ifnet_copy_label(struct label *src, struct label *dest)
276 {
277
278 MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest);
279 }
280
281 static int
282 mac_ifnet_externalize_label(struct label *label, char *elements,
283 char *outbuf, size_t outbuflen)
284 {
285 int error;
286
287 MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
288
289 return (error);
290 }
291
292 static int
293 mac_ifnet_internalize_label(struct label *label, char *string)
294 {
295 int error;
296
297 MAC_POLICY_INTERNALIZE(ifnet, label, string);
298
299 return (error);
300 }
301
302 void
303 mac_ifnet_create(struct ifnet *ifp)
304 {
305 int locked;
306
307 if (mac_policy_count == 0)
308 return;
309
310 MAC_IFNET_LOCK(ifp, locked);
311 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, ifp->if_label);
312 MAC_IFNET_UNLOCK(ifp, locked);
313 }
314
315 void
316 mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d)
317 {
318
319 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label);
320 }
321
322 void
323 mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m)
324 {
325 struct label *label;
326
327 /* Assume reader lock is enough. */
328 BPFD_LOCK_ASSERT(d);
329
330 if (mac_policy_count == 0)
331 return;
332
333 label = mac_mbuf_to_label(m);
334
335 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m,
336 label);
337 }
338
339 void
340 mac_ifnet_create_mbuf(struct ifnet *ifp, struct mbuf *m)
341 {
342 struct label *label;
343 int locked;
344
345 if (mac_policy_count == 0)
346 return;
347
348 label = mac_mbuf_to_label(m);
349
350 MAC_IFNET_LOCK(ifp, locked);
351 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, ifp->if_label, m,
352 label);
353 MAC_IFNET_UNLOCK(ifp, locked);
354 }
355
356 MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *",
357 "struct ifnet *");
358
359 int
360 mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp)
361 {
362 int error, locked;
363
364 /* Assume reader lock is enough. */
365 BPFD_LOCK_ASSERT(d);
366
367 if (mac_policy_count == 0)
368 return (0);
369
370 MAC_IFNET_LOCK(ifp, locked);
371 MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp,
372 ifp->if_label);
373 MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp);
374 MAC_IFNET_UNLOCK(ifp, locked);
375
376 return (error);
377 }
378
379 MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *",
380 "struct mbuf *");
381
382 int
383 mac_ifnet_check_transmit(struct ifnet *ifp, struct mbuf *m)
384 {
385 struct label *label;
386 int error, locked;
387
388 M_ASSERTPKTHDR(m);
389
390 if (mac_policy_count == 0)
391 return (0);
392
393 label = mac_mbuf_to_label(m);
394
395 MAC_IFNET_LOCK(ifp, locked);
396 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, ifp->if_label, m,
397 label);
398 MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m);
399 MAC_IFNET_UNLOCK(ifp, locked);
400
401 return (error);
402 }
403
404 int
405 mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr,
406 struct ifnet *ifp)
407 {
408 char *elements, *buffer;
409 struct label *intlabel;
410 struct mac mac;
411 int error, locked;
412
413 if (!(mac_labeled & MPC_OBJECT_IFNET))
414 return (EINVAL);
415
416 error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
417 if (error)
418 return (error);
419
420 error = mac_check_structmac_consistent(&mac);
421 if (error)
422 return (error);
423
424 elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
425 error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
426 if (error) {
427 free(elements, M_MACTEMP);
428 return (error);
429 }
430
431 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
432 intlabel = mac_ifnet_label_alloc();
433 MAC_IFNET_LOCK(ifp, locked);
434 mac_ifnet_copy_label(ifp->if_label, intlabel);
435 MAC_IFNET_UNLOCK(ifp, locked);
436 error = mac_ifnet_externalize_label(intlabel, elements, buffer,
437 mac.m_buflen);
438 mac_ifnet_label_free(intlabel);
439 if (error == 0)
440 error = copyout(buffer, mac.m_string, strlen(buffer)+1);
441
442 free(buffer, M_MACTEMP);
443 free(elements, M_MACTEMP);
444
445 return (error);
446 }
447
448 int
449 mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp)
450 {
451 struct label *intlabel;
452 struct mac mac;
453 char *buffer;
454 int error, locked;
455
456 if (!(mac_labeled & MPC_OBJECT_IFNET))
457 return (EINVAL);
458
459 error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
460 if (error)
461 return (error);
462
463 error = mac_check_structmac_consistent(&mac);
464 if (error)
465 return (error);
466
467 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
468 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
469 if (error) {
470 free(buffer, M_MACTEMP);
471 return (error);
472 }
473
474 intlabel = mac_ifnet_label_alloc();
475 error = mac_ifnet_internalize_label(intlabel, buffer);
476 free(buffer, M_MACTEMP);
477 if (error) {
478 mac_ifnet_label_free(intlabel);
479 return (error);
480 }
481
482 /*
483 * XXX: Note that this is a redundant privilege check, since policies
484 * impose this check themselves if required by the policy
485 * Eventually, this should go away.
486 */
487 error = priv_check_cred(cred, PRIV_NET_SETIFMAC);
488 if (error) {
489 mac_ifnet_label_free(intlabel);
490 return (error);
491 }
492
493 MAC_IFNET_LOCK(ifp, locked);
494 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp,
495 ifp->if_label, intlabel);
496 if (error) {
497 MAC_IFNET_UNLOCK(ifp, locked);
498 mac_ifnet_label_free(intlabel);
499 return (error);
500 }
501
502 MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, ifp->if_label,
503 intlabel);
504 MAC_IFNET_UNLOCK(ifp, locked);
505
506 mac_ifnet_label_free(intlabel);
507 return (0);
508 }
Cache object: 91fbb10679661d8b19cfe6b9c222c317
|