1 /*-
2 * Copyright (c) 1999-2002, 2009 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 struct mtx mac_ifnet_mtx;
82 MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
83
84 /*
85 * Retrieve the label associated with an mbuf by searching for the tag.
86 * Depending on the value of mac_labelmbufs, it's possible that a label will
87 * not be present, in which case NULL is returned. Policies must handle the
88 * possibility of an mbuf not having label storage if they do not enforce
89 * early loading.
90 */
91 struct label *
92 mac_mbuf_to_label(struct mbuf *m)
93 {
94 struct m_tag *tag;
95 struct label *label;
96
97 if (m == NULL)
98 return (NULL);
99 tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL);
100 if (tag == NULL)
101 return (NULL);
102 label = (struct label *)(tag+1);
103 return (label);
104 }
105
106 static struct label *
107 mac_bpfdesc_label_alloc(void)
108 {
109 struct label *label;
110
111 label = mac_labelzone_alloc(M_WAITOK);
112 MAC_POLICY_PERFORM(bpfdesc_init_label, label);
113 return (label);
114 }
115
116 void
117 mac_bpfdesc_init(struct bpf_d *d)
118 {
119
120 if (mac_labeled & MPC_OBJECT_BPFDESC)
121 d->bd_label = mac_bpfdesc_label_alloc();
122 else
123 d->bd_label = NULL;
124 }
125
126 static struct label *
127 mac_ifnet_label_alloc(void)
128 {
129 struct label *label;
130
131 label = mac_labelzone_alloc(M_WAITOK);
132 MAC_POLICY_PERFORM(ifnet_init_label, label);
133 return (label);
134 }
135
136 void
137 mac_ifnet_init(struct ifnet *ifp)
138 {
139
140 if (mac_labeled & MPC_OBJECT_IFNET)
141 ifp->if_label = mac_ifnet_label_alloc();
142 else
143 ifp->if_label = NULL;
144 }
145
146 int
147 mac_mbuf_tag_init(struct m_tag *tag, int flag)
148 {
149 struct label *label;
150 int error;
151
152 label = (struct label *) (tag + 1);
153 mac_init_label(label);
154
155 if (flag & M_WAITOK)
156 MAC_POLICY_CHECK(mbuf_init_label, label, flag);
157 else
158 MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag);
159 if (error) {
160 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
161 mac_destroy_label(label);
162 }
163 return (error);
164 }
165
166 int
167 mac_mbuf_init(struct mbuf *m, int flag)
168 {
169 struct m_tag *tag;
170 int error;
171
172 M_ASSERTPKTHDR(m);
173
174 if (mac_labeled & MPC_OBJECT_MBUF) {
175 tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
176 flag);
177 if (tag == NULL)
178 return (ENOMEM);
179 error = mac_mbuf_tag_init(tag, flag);
180 if (error) {
181 m_tag_free(tag);
182 return (error);
183 }
184 m_tag_prepend(m, tag);
185 }
186 return (0);
187 }
188
189 static void
190 mac_bpfdesc_label_free(struct label *label)
191 {
192
193 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label);
194 mac_labelzone_free(label);
195 }
196
197 void
198 mac_bpfdesc_destroy(struct bpf_d *d)
199 {
200
201 if (d->bd_label != NULL) {
202 mac_bpfdesc_label_free(d->bd_label);
203 d->bd_label = NULL;
204 }
205 }
206
207 static void
208 mac_ifnet_label_free(struct label *label)
209 {
210
211 MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label);
212 mac_labelzone_free(label);
213 }
214
215 void
216 mac_ifnet_destroy(struct ifnet *ifp)
217 {
218
219 if (ifp->if_label != NULL) {
220 mac_ifnet_label_free(ifp->if_label);
221 ifp->if_label = NULL;
222 }
223 }
224
225 void
226 mac_mbuf_tag_destroy(struct m_tag *tag)
227 {
228 struct label *label;
229
230 label = (struct label *)(tag+1);
231
232 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
233 mac_destroy_label(label);
234 }
235
236 /*
237 * mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which
238 * case the labels must also be duplicated.
239 */
240 void
241 mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest)
242 {
243 struct label *src_label, *dest_label;
244
245 src_label = (struct label *)(src+1);
246 dest_label = (struct label *)(dest+1);
247
248 /*
249 * mac_mbuf_tag_init() is called on the target tag in m_tag_copy(),
250 * so we don't need to call it here.
251 */
252 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
253 }
254
255 void
256 mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to)
257 {
258 struct label *src_label, *dest_label;
259
260 if (mac_policy_count == 0)
261 return;
262
263 src_label = mac_mbuf_to_label(m_from);
264 dest_label = mac_mbuf_to_label(m_to);
265
266 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
267 }
268
269 static void
270 mac_ifnet_copy_label(struct label *src, struct label *dest)
271 {
272
273 MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest);
274 }
275
276 static int
277 mac_ifnet_externalize_label(struct label *label, char *elements,
278 char *outbuf, size_t outbuflen)
279 {
280 int error;
281
282 MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
283
284 return (error);
285 }
286
287 static int
288 mac_ifnet_internalize_label(struct label *label, char *string)
289 {
290 int error;
291
292 MAC_POLICY_INTERNALIZE(ifnet, label, string);
293
294 return (error);
295 }
296
297 void
298 mac_ifnet_create(struct ifnet *ifp)
299 {
300
301 if (mac_policy_count == 0)
302 return;
303
304 MAC_IFNET_LOCK(ifp);
305 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, ifp->if_label);
306 MAC_IFNET_UNLOCK(ifp);
307 }
308
309 void
310 mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d)
311 {
312
313 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label);
314 }
315
316 void
317 mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m)
318 {
319 struct label *label;
320
321 /* Assume reader lock is enough. */
322 BPFD_LOCK_ASSERT(d);
323
324 if (mac_policy_count == 0)
325 return;
326
327 label = mac_mbuf_to_label(m);
328
329 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m,
330 label);
331 }
332
333 void
334 mac_ifnet_create_mbuf(struct ifnet *ifp, struct mbuf *m)
335 {
336 struct label *label;
337
338 if (mac_policy_count == 0)
339 return;
340
341 label = mac_mbuf_to_label(m);
342
343 MAC_IFNET_LOCK(ifp);
344 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, ifp->if_label, m,
345 label);
346 MAC_IFNET_UNLOCK(ifp);
347 }
348
349 MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *",
350 "struct ifnet *");
351
352 int
353 mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp)
354 {
355 int error;
356
357 /* Assume reader lock is enough. */
358 BPFD_LOCK_ASSERT(d);
359
360 if (mac_policy_count == 0)
361 return (0);
362
363 MAC_IFNET_LOCK(ifp);
364 MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp,
365 ifp->if_label);
366 MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp);
367 MAC_IFNET_UNLOCK(ifp);
368
369 return (error);
370 }
371
372 MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *",
373 "struct mbuf *");
374
375 int
376 mac_ifnet_check_transmit(struct ifnet *ifp, struct mbuf *m)
377 {
378 struct label *label;
379 int error;
380
381 M_ASSERTPKTHDR(m);
382
383 if (mac_policy_count == 0)
384 return (0);
385
386 label = mac_mbuf_to_label(m);
387
388 MAC_IFNET_LOCK(ifp);
389 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, ifp->if_label, m,
390 label);
391 MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m);
392 MAC_IFNET_UNLOCK(ifp);
393
394 return (error);
395 }
396
397 int
398 mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr,
399 struct ifnet *ifp)
400 {
401 char *elements, *buffer;
402 struct label *intlabel;
403 struct mac mac;
404 int error;
405
406 if (!(mac_labeled & MPC_OBJECT_IFNET))
407 return (EINVAL);
408
409 error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
410 if (error)
411 return (error);
412
413 error = mac_check_structmac_consistent(&mac);
414 if (error)
415 return (error);
416
417 elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
418 error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
419 if (error) {
420 free(elements, M_MACTEMP);
421 return (error);
422 }
423
424 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
425 intlabel = mac_ifnet_label_alloc();
426 MAC_IFNET_LOCK(ifp);
427 mac_ifnet_copy_label(ifp->if_label, intlabel);
428 MAC_IFNET_UNLOCK(ifp);
429 error = mac_ifnet_externalize_label(intlabel, elements, buffer,
430 mac.m_buflen);
431 mac_ifnet_label_free(intlabel);
432 if (error == 0)
433 error = copyout(buffer, mac.m_string, strlen(buffer)+1);
434
435 free(buffer, M_MACTEMP);
436 free(elements, M_MACTEMP);
437
438 return (error);
439 }
440
441 int
442 mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp)
443 {
444 struct label *intlabel;
445 struct mac mac;
446 char *buffer;
447 int error;
448
449 if (!(mac_labeled & MPC_OBJECT_IFNET))
450 return (EINVAL);
451
452 error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
453 if (error)
454 return (error);
455
456 error = mac_check_structmac_consistent(&mac);
457 if (error)
458 return (error);
459
460 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
461 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
462 if (error) {
463 free(buffer, M_MACTEMP);
464 return (error);
465 }
466
467 intlabel = mac_ifnet_label_alloc();
468 error = mac_ifnet_internalize_label(intlabel, buffer);
469 free(buffer, M_MACTEMP);
470 if (error) {
471 mac_ifnet_label_free(intlabel);
472 return (error);
473 }
474
475 /*
476 * XXX: Note that this is a redundant privilege check, since policies
477 * impose this check themselves if required by the policy
478 * Eventually, this should go away.
479 */
480 error = priv_check_cred(cred, PRIV_NET_SETIFMAC, 0);
481 if (error) {
482 mac_ifnet_label_free(intlabel);
483 return (error);
484 }
485
486 MAC_IFNET_LOCK(ifp);
487 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp,
488 ifp->if_label, intlabel);
489 if (error) {
490 MAC_IFNET_UNLOCK(ifp);
491 mac_ifnet_label_free(intlabel);
492 return (error);
493 }
494
495 MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, ifp->if_label,
496 intlabel);
497 MAC_IFNET_UNLOCK(ifp);
498
499 mac_ifnet_label_free(intlabel);
500 return (0);
501 }
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