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: releng/10.0/sys/security/mac/mac_net.c 233937 2012-04-06 06:53:58Z melifaro $");
47
48 #include "opt_kdtrace.h"
49 #include "opt_mac.h"
50
51 #include <sys/param.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/mutex.h>
56 #include <sys/mac.h>
57 #include <sys/priv.h>
58 #include <sys/sbuf.h>
59 #include <sys/sdt.h>
60 #include <sys/systm.h>
61 #include <sys/mount.h>
62 #include <sys/file.h>
63 #include <sys/namei.h>
64 #include <sys/protosw.h>
65 #include <sys/socket.h>
66 #include <sys/socketvar.h>
67 #include <sys/sysctl.h>
68
69 #include <net/bpfdesc.h>
70 #include <net/if.h>
71 #include <net/if_var.h>
72
73 #include <security/mac/mac_framework.h>
74 #include <security/mac/mac_internal.h>
75 #include <security/mac/mac_policy.h>
76
77 /*
78 * XXXRW: struct ifnet locking is incomplete in the network code, so we use
79 * our own global mutex for struct ifnet. Non-ideal, but should help in the
80 * SMP environment.
81 */
82 struct mtx mac_ifnet_mtx;
83 MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
84
85 /*
86 * Retrieve the label associated with an mbuf by searching for the tag.
87 * Depending on the value of mac_labelmbufs, it's possible that a label will
88 * not be present, in which case NULL is returned. Policies must handle the
89 * possibility of an mbuf not having label storage if they do not enforce
90 * early loading.
91 */
92 struct label *
93 mac_mbuf_to_label(struct mbuf *m)
94 {
95 struct m_tag *tag;
96 struct label *label;
97
98 if (m == NULL)
99 return (NULL);
100 tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL);
101 if (tag == NULL)
102 return (NULL);
103 label = (struct label *)(tag+1);
104 return (label);
105 }
106
107 static struct label *
108 mac_bpfdesc_label_alloc(void)
109 {
110 struct label *label;
111
112 label = mac_labelzone_alloc(M_WAITOK);
113 MAC_POLICY_PERFORM(bpfdesc_init_label, label);
114 return (label);
115 }
116
117 void
118 mac_bpfdesc_init(struct bpf_d *d)
119 {
120
121 if (mac_labeled & MPC_OBJECT_BPFDESC)
122 d->bd_label = mac_bpfdesc_label_alloc();
123 else
124 d->bd_label = NULL;
125 }
126
127 static struct label *
128 mac_ifnet_label_alloc(void)
129 {
130 struct label *label;
131
132 label = mac_labelzone_alloc(M_WAITOK);
133 MAC_POLICY_PERFORM(ifnet_init_label, label);
134 return (label);
135 }
136
137 void
138 mac_ifnet_init(struct ifnet *ifp)
139 {
140
141 if (mac_labeled & MPC_OBJECT_IFNET)
142 ifp->if_label = mac_ifnet_label_alloc();
143 else
144 ifp->if_label = NULL;
145 }
146
147 int
148 mac_mbuf_tag_init(struct m_tag *tag, int flag)
149 {
150 struct label *label;
151 int error;
152
153 label = (struct label *) (tag + 1);
154 mac_init_label(label);
155
156 if (flag & M_WAITOK)
157 MAC_POLICY_CHECK(mbuf_init_label, label, flag);
158 else
159 MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag);
160 if (error) {
161 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
162 mac_destroy_label(label);
163 }
164 return (error);
165 }
166
167 int
168 mac_mbuf_init(struct mbuf *m, int flag)
169 {
170 struct m_tag *tag;
171 int error;
172
173 M_ASSERTPKTHDR(m);
174
175 if (mac_labeled & MPC_OBJECT_MBUF) {
176 tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
177 flag);
178 if (tag == NULL)
179 return (ENOMEM);
180 error = mac_mbuf_tag_init(tag, flag);
181 if (error) {
182 m_tag_free(tag);
183 return (error);
184 }
185 m_tag_prepend(m, tag);
186 }
187 return (0);
188 }
189
190 static void
191 mac_bpfdesc_label_free(struct label *label)
192 {
193
194 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label);
195 mac_labelzone_free(label);
196 }
197
198 void
199 mac_bpfdesc_destroy(struct bpf_d *d)
200 {
201
202 if (d->bd_label != NULL) {
203 mac_bpfdesc_label_free(d->bd_label);
204 d->bd_label = NULL;
205 }
206 }
207
208 static void
209 mac_ifnet_label_free(struct label *label)
210 {
211
212 MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label);
213 mac_labelzone_free(label);
214 }
215
216 void
217 mac_ifnet_destroy(struct ifnet *ifp)
218 {
219
220 if (ifp->if_label != NULL) {
221 mac_ifnet_label_free(ifp->if_label);
222 ifp->if_label = NULL;
223 }
224 }
225
226 void
227 mac_mbuf_tag_destroy(struct m_tag *tag)
228 {
229 struct label *label;
230
231 label = (struct label *)(tag+1);
232
233 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
234 mac_destroy_label(label);
235 }
236
237 /*
238 * mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which
239 * case the labels must also be duplicated.
240 */
241 void
242 mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest)
243 {
244 struct label *src_label, *dest_label;
245
246 src_label = (struct label *)(src+1);
247 dest_label = (struct label *)(dest+1);
248
249 /*
250 * mac_mbuf_tag_init() is called on the target tag in m_tag_copy(),
251 * so we don't need to call it here.
252 */
253 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
254 }
255
256 void
257 mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to)
258 {
259 struct label *src_label, *dest_label;
260
261 if (mac_policy_count == 0)
262 return;
263
264 src_label = mac_mbuf_to_label(m_from);
265 dest_label = mac_mbuf_to_label(m_to);
266
267 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
268 }
269
270 static void
271 mac_ifnet_copy_label(struct label *src, struct label *dest)
272 {
273
274 MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest);
275 }
276
277 static int
278 mac_ifnet_externalize_label(struct label *label, char *elements,
279 char *outbuf, size_t outbuflen)
280 {
281 int error;
282
283 MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
284
285 return (error);
286 }
287
288 static int
289 mac_ifnet_internalize_label(struct label *label, char *string)
290 {
291 int error;
292
293 MAC_POLICY_INTERNALIZE(ifnet, label, string);
294
295 return (error);
296 }
297
298 void
299 mac_ifnet_create(struct ifnet *ifp)
300 {
301
302 if (mac_policy_count == 0)
303 return;
304
305 MAC_IFNET_LOCK(ifp);
306 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, ifp->if_label);
307 MAC_IFNET_UNLOCK(ifp);
308 }
309
310 void
311 mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d)
312 {
313
314 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label);
315 }
316
317 void
318 mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m)
319 {
320 struct label *label;
321
322 /* Assume reader lock is enough. */
323 BPFD_LOCK_ASSERT(d);
324
325 if (mac_policy_count == 0)
326 return;
327
328 label = mac_mbuf_to_label(m);
329
330 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m,
331 label);
332 }
333
334 void
335 mac_ifnet_create_mbuf(struct ifnet *ifp, struct mbuf *m)
336 {
337 struct label *label;
338
339 if (mac_policy_count == 0)
340 return;
341
342 label = mac_mbuf_to_label(m);
343
344 MAC_IFNET_LOCK(ifp);
345 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, ifp->if_label, m,
346 label);
347 MAC_IFNET_UNLOCK(ifp);
348 }
349
350 MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *",
351 "struct ifnet *");
352
353 int
354 mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp)
355 {
356 int error;
357
358 /* Assume reader lock is enough. */
359 BPFD_LOCK_ASSERT(d);
360
361 if (mac_policy_count == 0)
362 return (0);
363
364 MAC_IFNET_LOCK(ifp);
365 MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp,
366 ifp->if_label);
367 MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp);
368 MAC_IFNET_UNLOCK(ifp);
369
370 return (error);
371 }
372
373 MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *",
374 "struct mbuf *");
375
376 int
377 mac_ifnet_check_transmit(struct ifnet *ifp, struct mbuf *m)
378 {
379 struct label *label;
380 int error;
381
382 M_ASSERTPKTHDR(m);
383
384 if (mac_policy_count == 0)
385 return (0);
386
387 label = mac_mbuf_to_label(m);
388
389 MAC_IFNET_LOCK(ifp);
390 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, ifp->if_label, m,
391 label);
392 MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m);
393 MAC_IFNET_UNLOCK(ifp);
394
395 return (error);
396 }
397
398 int
399 mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr,
400 struct ifnet *ifp)
401 {
402 char *elements, *buffer;
403 struct label *intlabel;
404 struct mac mac;
405 int error;
406
407 if (!(mac_labeled & MPC_OBJECT_IFNET))
408 return (EINVAL);
409
410 error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
411 if (error)
412 return (error);
413
414 error = mac_check_structmac_consistent(&mac);
415 if (error)
416 return (error);
417
418 elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
419 error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
420 if (error) {
421 free(elements, M_MACTEMP);
422 return (error);
423 }
424
425 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
426 intlabel = mac_ifnet_label_alloc();
427 MAC_IFNET_LOCK(ifp);
428 mac_ifnet_copy_label(ifp->if_label, intlabel);
429 MAC_IFNET_UNLOCK(ifp);
430 error = mac_ifnet_externalize_label(intlabel, elements, buffer,
431 mac.m_buflen);
432 mac_ifnet_label_free(intlabel);
433 if (error == 0)
434 error = copyout(buffer, mac.m_string, strlen(buffer)+1);
435
436 free(buffer, M_MACTEMP);
437 free(elements, M_MACTEMP);
438
439 return (error);
440 }
441
442 int
443 mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp)
444 {
445 struct label *intlabel;
446 struct mac mac;
447 char *buffer;
448 int error;
449
450 if (!(mac_labeled & MPC_OBJECT_IFNET))
451 return (EINVAL);
452
453 error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac));
454 if (error)
455 return (error);
456
457 error = mac_check_structmac_consistent(&mac);
458 if (error)
459 return (error);
460
461 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
462 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
463 if (error) {
464 free(buffer, M_MACTEMP);
465 return (error);
466 }
467
468 intlabel = mac_ifnet_label_alloc();
469 error = mac_ifnet_internalize_label(intlabel, buffer);
470 free(buffer, M_MACTEMP);
471 if (error) {
472 mac_ifnet_label_free(intlabel);
473 return (error);
474 }
475
476 /*
477 * XXX: Note that this is a redundant privilege check, since policies
478 * impose this check themselves if required by the policy
479 * Eventually, this should go away.
480 */
481 error = priv_check_cred(cred, PRIV_NET_SETIFMAC, 0);
482 if (error) {
483 mac_ifnet_label_free(intlabel);
484 return (error);
485 }
486
487 MAC_IFNET_LOCK(ifp);
488 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp,
489 ifp->if_label, intlabel);
490 if (error) {
491 MAC_IFNET_UNLOCK(ifp);
492 mac_ifnet_label_free(intlabel);
493 return (error);
494 }
495
496 MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, ifp->if_label,
497 intlabel);
498 MAC_IFNET_UNLOCK(ifp);
499
500 mac_ifnet_label_free(intlabel);
501 return (0);
502 }
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