1 /*-
2 * Copyright (c) 1999-2002, 2006, 2009 Robert N. M. Watson
3 * Copyright (c) 2001 Ilmar S. Habibulin
4 * Copyright (c) 2001-2005 Networks Associates Technology, Inc.
5 * Copyright (c) 2005-2006 SPARTA, Inc.
6 * Copyright (c) 2008-2009 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 developed for the FreeBSD Project in part by Network
13 * Associates Laboratories, the Security Research Division of Network
14 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
15 * as part of the DARPA CHATS research program.
16 *
17 * This software was enhanced by SPARTA ISSO under SPAWAR contract
18 * N66001-04-C-6019 ("SEFOS").
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 /*-
46 * Framework for extensible kernel access control. This file contains core
47 * kernel infrastructure for the TrustedBSD MAC Framework, including policy
48 * registration, versioning, locking, error composition operator, and system
49 * calls.
50 *
51 * The MAC Framework implements three programming interfaces:
52 *
53 * - The kernel MAC interface, defined in mac_framework.h, and invoked
54 * throughout the kernel to request security decisions, notify of security
55 * related events, etc.
56 *
57 * - The MAC policy module interface, defined in mac_policy.h, which is
58 * implemented by MAC policy modules and invoked by the MAC Framework to
59 * forward kernel security requests and notifications to policy modules.
60 *
61 * - The user MAC API, defined in mac.h, which allows user programs to query
62 * and set label state on objects.
63 *
64 * The majority of the MAC Framework implementation may be found in
65 * src/sys/security/mac. Sample policy modules may be found in
66 * src/sys/security/mac_*.
67 */
68
69 #include "opt_mac.h"
70
71 #include <sys/cdefs.h>
72 __FBSDID("$FreeBSD$");
73
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/condvar.h>
77 #include <sys/kernel.h>
78 #include <sys/lock.h>
79 #include <sys/mac.h>
80 #include <sys/module.h>
81 #include <sys/rmlock.h>
82 #include <sys/sdt.h>
83 #include <sys/sx.h>
84 #include <sys/sysctl.h>
85 #include <sys/vnode.h>
86
87 #include <security/mac/mac_framework.h>
88 #include <security/mac/mac_internal.h>
89 #include <security/mac/mac_policy.h>
90
91 /*
92 * DTrace SDT providers for MAC.
93 */
94 SDT_PROVIDER_DEFINE(mac);
95 SDT_PROVIDER_DEFINE(mac_framework);
96
97 SDT_PROBE_DEFINE2(mac, , policy, modevent, "int",
98 "struct mac_policy_conf *");
99 SDT_PROBE_DEFINE1(mac, , policy, register,
100 "struct mac_policy_conf *");
101 SDT_PROBE_DEFINE1(mac, , policy, unregister,
102 "struct mac_policy_conf *");
103
104 /*
105 * Root sysctl node for all MAC and MAC policy controls.
106 */
107 SYSCTL_NODE(_security, OID_AUTO, mac, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
108 "TrustedBSD MAC policy controls");
109
110 /*
111 * Declare that the kernel provides MAC support, version 3 (FreeBSD 7.x).
112 * This permits modules to refuse to be loaded if the necessary support isn't
113 * present, even if it's pre-boot.
114 */
115 MODULE_VERSION(kernel_mac_support, MAC_VERSION);
116
117 static unsigned int mac_version = MAC_VERSION;
118 SYSCTL_UINT(_security_mac, OID_AUTO, version, CTLFLAG_RD, &mac_version, 0,
119 "");
120
121 /*
122 * Flags for inlined checks. Note this would be best hotpatched at runtime.
123 * The following is a band-aid.
124 *
125 * Use FPFLAG for hooks running in commonly executed paths and FPFLAG_RARE
126 * for the rest.
127 */
128 #define FPFLAG(f) \
129 bool __read_frequently mac_##f##_fp_flag
130
131 #define FPFLAG_RARE(f) \
132 bool __read_mostly mac_##f##_fp_flag
133
134 FPFLAG(priv_check);
135 FPFLAG(priv_grant);
136 FPFLAG(vnode_check_lookup);
137 FPFLAG(vnode_check_open);
138 FPFLAG(vnode_check_stat);
139 FPFLAG(vnode_check_read);
140 FPFLAG(vnode_check_write);
141 FPFLAG(vnode_check_mmap);
142 FPFLAG_RARE(vnode_check_poll);
143 FPFLAG_RARE(vnode_check_rename_from);
144 FPFLAG_RARE(vnode_check_access);
145 FPFLAG_RARE(vnode_check_readlink);
146 FPFLAG_RARE(pipe_check_stat);
147 FPFLAG_RARE(pipe_check_poll);
148 FPFLAG_RARE(pipe_check_read);
149 FPFLAG_RARE(ifnet_create_mbuf);
150 FPFLAG_RARE(ifnet_check_transmit);
151
152 #undef FPFLAG
153 #undef FPFLAG_RARE
154
155 /*
156 * Labels consist of a indexed set of "slots", which are allocated policies
157 * as required. The MAC Framework maintains a bitmask of slots allocated so
158 * far to prevent reuse. Slots cannot be reused, as the MAC Framework
159 * guarantees that newly allocated slots in labels will be NULL unless
160 * otherwise initialized, and because we do not have a mechanism to garbage
161 * collect slots on policy unload. As labeled policies tend to be statically
162 * loaded during boot, and not frequently unloaded and reloaded, this is not
163 * generally an issue.
164 */
165 #if MAC_MAX_SLOTS > 32
166 #error "MAC_MAX_SLOTS too large"
167 #endif
168
169 static unsigned int mac_max_slots = MAC_MAX_SLOTS;
170 static unsigned int mac_slot_offsets_free = (1 << MAC_MAX_SLOTS) - 1;
171 SYSCTL_UINT(_security_mac, OID_AUTO, max_slots, CTLFLAG_RD, &mac_max_slots,
172 0, "");
173
174 /*
175 * Has the kernel started generating labeled objects yet? All read/write
176 * access to this variable is serialized during the boot process. Following
177 * the end of serialization, we don't update this flag; no locking.
178 */
179 static int mac_late = 0;
180
181 /*
182 * Each policy declares a mask of object types requiring labels to be
183 * allocated for them. For convenience, we combine and cache the bitwise or
184 * of the per-policy object flags to track whether we will allocate a label
185 * for an object type at run-time.
186 */
187 uint64_t mac_labeled;
188 SYSCTL_UQUAD(_security_mac, OID_AUTO, labeled, CTLFLAG_RD, &mac_labeled, 0,
189 "Mask of object types being labeled");
190
191 MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage");
192
193 /*
194 * MAC policy modules are placed in one of two lists: mac_static_policy_list,
195 * for policies that are loaded early and cannot be unloaded, and
196 * mac_policy_list, which holds policies either loaded later in the boot
197 * cycle or that may be unloaded. The static policy list does not require
198 * locks to iterate over, but the dynamic list requires synchronization.
199 * Support for dynamic policy loading can be compiled out using the
200 * MAC_STATIC kernel option.
201 *
202 * The dynamic policy list is protected by two locks: modifying the list
203 * requires both locks to be held exclusively. One of the locks,
204 * mac_policy_rm, is acquired over policy entry points that will never sleep;
205 * the other, mac_policy_rms, is acquired over policy entry points that may
206 * sleep. The former category will be used when kernel locks may be held
207 * over calls to the MAC Framework, during network processing in ithreads,
208 * etc. The latter will tend to involve potentially blocking memory
209 * allocations, extended attribute I/O, etc.
210 */
211 #ifndef MAC_STATIC
212 static struct rmlock mac_policy_rm; /* Non-sleeping entry points. */
213 static struct rmslock mac_policy_rms; /* Sleeping entry points. */
214 #endif
215
216 struct mac_policy_list_head mac_policy_list;
217 struct mac_policy_list_head mac_static_policy_list;
218 u_int mac_policy_count; /* Registered policy count. */
219
220 static void mac_policy_xlock(void);
221 static void mac_policy_xlock_assert(void);
222 static void mac_policy_xunlock(void);
223
224 void
225 mac_policy_slock_nosleep(struct rm_priotracker *tracker)
226 {
227
228 #ifndef MAC_STATIC
229 if (!mac_late)
230 return;
231
232 rm_rlock(&mac_policy_rm, tracker);
233 #endif
234 }
235
236 void
237 mac_policy_slock_sleep(void)
238 {
239
240 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
241 "mac_policy_slock_sleep");
242
243 #ifndef MAC_STATIC
244 if (!mac_late)
245 return;
246
247 rms_rlock(&mac_policy_rms);
248 #endif
249 }
250
251 void
252 mac_policy_sunlock_nosleep(struct rm_priotracker *tracker)
253 {
254
255 #ifndef MAC_STATIC
256 if (!mac_late)
257 return;
258
259 rm_runlock(&mac_policy_rm, tracker);
260 #endif
261 }
262
263 void
264 mac_policy_sunlock_sleep(void)
265 {
266
267 #ifndef MAC_STATIC
268 if (!mac_late)
269 return;
270
271 rms_runlock(&mac_policy_rms);
272 #endif
273 }
274
275 static void
276 mac_policy_xlock(void)
277 {
278
279 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
280 "mac_policy_xlock()");
281
282 #ifndef MAC_STATIC
283 if (!mac_late)
284 return;
285
286 rms_wlock(&mac_policy_rms);
287 rm_wlock(&mac_policy_rm);
288 #endif
289 }
290
291 static void
292 mac_policy_xunlock(void)
293 {
294
295 #ifndef MAC_STATIC
296 if (!mac_late)
297 return;
298
299 rm_wunlock(&mac_policy_rm);
300 rms_wunlock(&mac_policy_rms);
301 #endif
302 }
303
304 static void
305 mac_policy_xlock_assert(void)
306 {
307
308 #ifndef MAC_STATIC
309 if (!mac_late)
310 return;
311
312 rm_assert(&mac_policy_rm, RA_WLOCKED);
313 #endif
314 }
315
316 /*
317 * Initialize the MAC subsystem, including appropriate SMP locks.
318 */
319 static void
320 mac_init(void)
321 {
322
323 LIST_INIT(&mac_static_policy_list);
324 LIST_INIT(&mac_policy_list);
325 mac_labelzone_init();
326
327 #ifndef MAC_STATIC
328 rm_init_flags(&mac_policy_rm, "mac_policy_rm", RM_NOWITNESS |
329 RM_RECURSE);
330 rms_init(&mac_policy_rms, "mac_policy_rms");
331 #endif
332 }
333
334 /*
335 * For the purposes of modules that want to know if they were loaded "early",
336 * set the mac_late flag once we've processed modules either linked into the
337 * kernel, or loaded before the kernel startup.
338 */
339 static void
340 mac_late_init(void)
341 {
342
343 mac_late = 1;
344 }
345
346 /*
347 * Given a policy, derive from its set of non-NULL label init methods what
348 * object types the policy is interested in.
349 */
350 static uint64_t
351 mac_policy_getlabeled(struct mac_policy_conf *mpc)
352 {
353 uint64_t labeled;
354
355 #define MPC_FLAG(method, flag) \
356 if (mpc->mpc_ops->mpo_ ## method != NULL) \
357 labeled |= (flag); \
358
359 labeled = 0;
360 MPC_FLAG(cred_init_label, MPC_OBJECT_CRED);
361 MPC_FLAG(proc_init_label, MPC_OBJECT_PROC);
362 MPC_FLAG(vnode_init_label, MPC_OBJECT_VNODE);
363 MPC_FLAG(inpcb_init_label, MPC_OBJECT_INPCB);
364 MPC_FLAG(socket_init_label, MPC_OBJECT_SOCKET);
365 MPC_FLAG(devfs_init_label, MPC_OBJECT_DEVFS);
366 MPC_FLAG(mbuf_init_label, MPC_OBJECT_MBUF);
367 MPC_FLAG(ipq_init_label, MPC_OBJECT_IPQ);
368 MPC_FLAG(ifnet_init_label, MPC_OBJECT_IFNET);
369 MPC_FLAG(bpfdesc_init_label, MPC_OBJECT_BPFDESC);
370 MPC_FLAG(pipe_init_label, MPC_OBJECT_PIPE);
371 MPC_FLAG(mount_init_label, MPC_OBJECT_MOUNT);
372 MPC_FLAG(posixsem_init_label, MPC_OBJECT_POSIXSEM);
373 MPC_FLAG(posixshm_init_label, MPC_OBJECT_POSIXSHM);
374 MPC_FLAG(sysvmsg_init_label, MPC_OBJECT_SYSVMSG);
375 MPC_FLAG(sysvmsq_init_label, MPC_OBJECT_SYSVMSQ);
376 MPC_FLAG(sysvsem_init_label, MPC_OBJECT_SYSVSEM);
377 MPC_FLAG(sysvshm_init_label, MPC_OBJECT_SYSVSHM);
378 MPC_FLAG(syncache_init_label, MPC_OBJECT_SYNCACHE);
379 MPC_FLAG(ip6q_init_label, MPC_OBJECT_IP6Q);
380
381 #undef MPC_FLAG
382 return (labeled);
383 }
384
385 /*
386 * When policies are loaded or unloaded, walk the list of registered policies
387 * and built mac_labeled, a bitmask representing the union of all objects
388 * requiring labels across all policies.
389 */
390 static void
391 mac_policy_update(void)
392 {
393 struct mac_policy_conf *mpc;
394
395 mac_policy_xlock_assert();
396
397 mac_labeled = 0;
398 mac_policy_count = 0;
399 LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) {
400 mac_labeled |= mac_policy_getlabeled(mpc);
401 mac_policy_count++;
402 }
403 LIST_FOREACH(mpc, &mac_policy_list, mpc_list) {
404 mac_labeled |= mac_policy_getlabeled(mpc);
405 mac_policy_count++;
406 }
407
408 cache_fast_lookup_enabled_recalc();
409 }
410
411 /*
412 * There are frequently used code paths which check for rarely installed
413 * policies. Gross hack below enables doing it in a cheap manner.
414 */
415
416 #define FPO(f) (offsetof(struct mac_policy_ops, mpo_##f) / sizeof(uintptr_t))
417
418 struct mac_policy_fastpath_elem {
419 int count;
420 bool *flag;
421 size_t offset;
422 };
423
424 struct mac_policy_fastpath_elem mac_policy_fastpath_array[] = {
425 { .offset = FPO(priv_check), .flag = &mac_priv_check_fp_flag },
426 { .offset = FPO(priv_grant), .flag = &mac_priv_grant_fp_flag },
427 { .offset = FPO(vnode_check_lookup),
428 .flag = &mac_vnode_check_lookup_fp_flag },
429 { .offset = FPO(vnode_check_readlink),
430 .flag = &mac_vnode_check_readlink_fp_flag },
431 { .offset = FPO(vnode_check_open),
432 .flag = &mac_vnode_check_open_fp_flag },
433 { .offset = FPO(vnode_check_stat),
434 .flag = &mac_vnode_check_stat_fp_flag },
435 { .offset = FPO(vnode_check_read),
436 .flag = &mac_vnode_check_read_fp_flag },
437 { .offset = FPO(vnode_check_write),
438 .flag = &mac_vnode_check_write_fp_flag },
439 { .offset = FPO(vnode_check_mmap),
440 .flag = &mac_vnode_check_mmap_fp_flag },
441 { .offset = FPO(vnode_check_poll),
442 .flag = &mac_vnode_check_poll_fp_flag },
443 { .offset = FPO(vnode_check_rename_from),
444 .flag = &mac_vnode_check_rename_from_fp_flag },
445 { .offset = FPO(vnode_check_access),
446 .flag = &mac_vnode_check_access_fp_flag },
447 { .offset = FPO(pipe_check_stat),
448 .flag = &mac_pipe_check_stat_fp_flag },
449 { .offset = FPO(pipe_check_poll),
450 .flag = &mac_pipe_check_poll_fp_flag },
451 { .offset = FPO(pipe_check_read),
452 .flag = &mac_pipe_check_read_fp_flag },
453 { .offset = FPO(ifnet_create_mbuf),
454 .flag = &mac_ifnet_create_mbuf_fp_flag },
455 { .offset = FPO(ifnet_check_transmit),
456 .flag = &mac_ifnet_check_transmit_fp_flag },
457 };
458
459 static void
460 mac_policy_fastpath_enable(struct mac_policy_fastpath_elem *mpfe)
461 {
462
463 MPASS(mpfe->count >= 0);
464 mpfe->count++;
465 if (mpfe->count == 1) {
466 MPASS(*mpfe->flag == false);
467 *mpfe->flag = true;
468 }
469 }
470
471 static void
472 mac_policy_fastpath_disable(struct mac_policy_fastpath_elem *mpfe)
473 {
474
475 MPASS(mpfe->count >= 1);
476 mpfe->count--;
477 if (mpfe->count == 0) {
478 MPASS(*mpfe->flag == true);
479 *mpfe->flag = false;
480 }
481 }
482
483 static void
484 mac_policy_fastpath_register(struct mac_policy_conf *mpc)
485 {
486 struct mac_policy_fastpath_elem *mpfe;
487 uintptr_t **ops;
488 int i;
489
490 mac_policy_xlock_assert();
491
492 ops = (uintptr_t **)mpc->mpc_ops;
493 for (i = 0; i < nitems(mac_policy_fastpath_array); i++) {
494 mpfe = &mac_policy_fastpath_array[i];
495 if (ops[mpfe->offset] != NULL)
496 mac_policy_fastpath_enable(mpfe);
497 }
498 }
499
500 static void
501 mac_policy_fastpath_unregister(struct mac_policy_conf *mpc)
502 {
503 struct mac_policy_fastpath_elem *mpfe;
504 uintptr_t **ops;
505 int i;
506
507 mac_policy_xlock_assert();
508
509 ops = (uintptr_t **)mpc->mpc_ops;
510 for (i = 0; i < nitems(mac_policy_fastpath_array); i++) {
511 mpfe = &mac_policy_fastpath_array[i];
512 if (ops[mpfe->offset] != NULL)
513 mac_policy_fastpath_disable(mpfe);
514 }
515 }
516
517 #undef FPO
518
519 static int
520 mac_policy_register(struct mac_policy_conf *mpc)
521 {
522 struct mac_policy_conf *tmpc;
523 int error, slot, static_entry;
524
525 error = 0;
526
527 /*
528 * We don't technically need exclusive access while !mac_late, but
529 * hold it for assertion consistency.
530 */
531 mac_policy_xlock();
532
533 /*
534 * If the module can potentially be unloaded, or we're loading late,
535 * we have to stick it in the non-static list and pay an extra
536 * performance overhead. Otherwise, we can pay a light locking cost
537 * and stick it in the static list.
538 */
539 static_entry = (!mac_late &&
540 !(mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK));
541
542 if (static_entry) {
543 LIST_FOREACH(tmpc, &mac_static_policy_list, mpc_list) {
544 if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
545 error = EEXIST;
546 goto out;
547 }
548 }
549 } else {
550 LIST_FOREACH(tmpc, &mac_policy_list, mpc_list) {
551 if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) {
552 error = EEXIST;
553 goto out;
554 }
555 }
556 }
557 if (mpc->mpc_field_off != NULL) {
558 slot = ffs(mac_slot_offsets_free);
559 if (slot == 0) {
560 error = ENOMEM;
561 goto out;
562 }
563 slot--;
564 mac_slot_offsets_free &= ~(1 << slot);
565 *mpc->mpc_field_off = slot;
566 }
567 mpc->mpc_runtime_flags |= MPC_RUNTIME_FLAG_REGISTERED;
568
569 /*
570 * If we're loading a MAC module after the framework has initialized,
571 * it has to go into the dynamic list. If we're loading it before
572 * we've finished initializing, it can go into the static list with
573 * weaker locker requirements.
574 */
575 if (static_entry)
576 LIST_INSERT_HEAD(&mac_static_policy_list, mpc, mpc_list);
577 else
578 LIST_INSERT_HEAD(&mac_policy_list, mpc, mpc_list);
579
580 /*
581 * Per-policy initialization. Currently, this takes place under the
582 * exclusive lock, so policies must not sleep in their init method.
583 * In the future, we may want to separate "init" from "start", with
584 * "init" occurring without the lock held. Likewise, on tear-down,
585 * breaking out "stop" from "destroy".
586 */
587 if (mpc->mpc_ops->mpo_init != NULL)
588 (*(mpc->mpc_ops->mpo_init))(mpc);
589
590 mac_policy_fastpath_register(mpc);
591
592 mac_policy_update();
593
594 SDT_PROBE1(mac, , policy, register, mpc);
595 printf("Security policy loaded: %s (%s)\n", mpc->mpc_fullname,
596 mpc->mpc_name);
597
598 out:
599 mac_policy_xunlock();
600 return (error);
601 }
602
603 static int
604 mac_policy_unregister(struct mac_policy_conf *mpc)
605 {
606
607 /*
608 * If we fail the load, we may get a request to unload. Check to see
609 * if we did the run-time registration, and if not, silently succeed.
610 */
611 mac_policy_xlock();
612 if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED) == 0) {
613 mac_policy_xunlock();
614 return (0);
615 }
616 #if 0
617 /*
618 * Don't allow unloading modules with private data.
619 */
620 if (mpc->mpc_field_off != NULL) {
621 mac_policy_xunlock();
622 return (EBUSY);
623 }
624 #endif
625 /*
626 * Only allow the unload to proceed if the module is unloadable by
627 * its own definition.
628 */
629 if ((mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK) == 0) {
630 mac_policy_xunlock();
631 return (EBUSY);
632 }
633
634 mac_policy_fastpath_unregister(mpc);
635
636 if (mpc->mpc_ops->mpo_destroy != NULL)
637 (*(mpc->mpc_ops->mpo_destroy))(mpc);
638
639 LIST_REMOVE(mpc, mpc_list);
640 mpc->mpc_runtime_flags &= ~MPC_RUNTIME_FLAG_REGISTERED;
641 mac_policy_update();
642 mac_policy_xunlock();
643
644 SDT_PROBE1(mac, , policy, unregister, mpc);
645 printf("Security policy unload: %s (%s)\n", mpc->mpc_fullname,
646 mpc->mpc_name);
647
648 return (0);
649 }
650
651 /*
652 * Allow MAC policy modules to register during boot, etc.
653 */
654 int
655 mac_policy_modevent(module_t mod, int type, void *data)
656 {
657 struct mac_policy_conf *mpc;
658 int error;
659
660 error = 0;
661 mpc = (struct mac_policy_conf *) data;
662
663 #ifdef MAC_STATIC
664 if (mac_late) {
665 printf("mac_policy_modevent: MAC_STATIC and late\n");
666 return (EBUSY);
667 }
668 #endif
669
670 SDT_PROBE2(mac, , policy, modevent, type, mpc);
671 switch (type) {
672 case MOD_LOAD:
673 if (mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_NOTLATE &&
674 mac_late) {
675 printf("mac_policy_modevent: can't load %s policy "
676 "after booting\n", mpc->mpc_name);
677 error = EBUSY;
678 break;
679 }
680 error = mac_policy_register(mpc);
681 break;
682 case MOD_UNLOAD:
683 /* Don't unregister the module if it was never registered. */
684 if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED)
685 != 0)
686 error = mac_policy_unregister(mpc);
687 else
688 error = 0;
689 break;
690 default:
691 error = EOPNOTSUPP;
692 break;
693 }
694
695 return (error);
696 }
697
698 /*
699 * Define an error value precedence, and given two arguments, selects the
700 * value with the higher precedence.
701 */
702 int
703 mac_error_select(int error1, int error2)
704 {
705
706 /* Certain decision-making errors take top priority. */
707 if (error1 == EDEADLK || error2 == EDEADLK)
708 return (EDEADLK);
709
710 /* Invalid arguments should be reported where possible. */
711 if (error1 == EINVAL || error2 == EINVAL)
712 return (EINVAL);
713
714 /* Precedence goes to "visibility", with both process and file. */
715 if (error1 == ESRCH || error2 == ESRCH)
716 return (ESRCH);
717
718 if (error1 == ENOENT || error2 == ENOENT)
719 return (ENOENT);
720
721 /* Precedence goes to DAC/MAC protections. */
722 if (error1 == EACCES || error2 == EACCES)
723 return (EACCES);
724
725 /* Precedence goes to privilege. */
726 if (error1 == EPERM || error2 == EPERM)
727 return (EPERM);
728
729 /* Precedence goes to error over success; otherwise, arbitrary. */
730 if (error1 != 0)
731 return (error1);
732 return (error2);
733 }
734
735 int
736 mac_check_structmac_consistent(struct mac *mac)
737 {
738
739 /* Require that labels have a non-zero length. */
740 if (mac->m_buflen > MAC_MAX_LABEL_BUF_LEN ||
741 mac->m_buflen <= sizeof(""))
742 return (EINVAL);
743
744 return (0);
745 }
746
747 SYSINIT(mac, SI_SUB_MAC, SI_ORDER_FIRST, mac_init, NULL);
748 SYSINIT(mac_late, SI_SUB_MAC_LATE, SI_ORDER_FIRST, mac_late_init, NULL);
Cache object: 9c1a10633fb73468a2fd9282b22facb0
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