xref: /freebsd/sys/security/mac_mls/mac_mls.c (revision d086ded32300bc0f33fb1574d0bcfccfbc60881d)
1 /*-
2  * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
3  * Copyright (c) 2001, 2002, 2003 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed by Robert Watson for the TrustedBSD Project.
7  *
8  * This software was developed for the FreeBSD Project in part by Network
9  * Associates Laboratories, the Security Research Division of Network
10  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
11  * as part of the DARPA CHATS research program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $FreeBSD$
35  */
36 
37 /*
38  * Developed by the TrustedBSD Project.
39  * MLS fixed label mandatory confidentiality policy.
40  */
41 
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/acl.h>
45 #include <sys/conf.h>
46 #include <sys/extattr.h>
47 #include <sys/kernel.h>
48 #include <sys/mac.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/proc.h>
52 #include <sys/sbuf.h>
53 #include <sys/systm.h>
54 #include <sys/sysproto.h>
55 #include <sys/sysent.h>
56 #include <sys/systm.h>
57 #include <sys/vnode.h>
58 #include <sys/file.h>
59 #include <sys/socket.h>
60 #include <sys/socketvar.h>
61 #include <sys/pipe.h>
62 #include <sys/sysctl.h>
63 
64 #include <fs/devfs/devfs.h>
65 
66 #include <net/bpfdesc.h>
67 #include <net/if.h>
68 #include <net/if_types.h>
69 #include <net/if_var.h>
70 
71 #include <netinet/in.h>
72 #include <netinet/ip_var.h>
73 
74 #include <vm/vm.h>
75 
76 #include <sys/mac_policy.h>
77 
78 #include <security/mac_mls/mac_mls.h>
79 
80 SYSCTL_DECL(_security_mac);
81 
82 SYSCTL_NODE(_security_mac, OID_AUTO, mls, CTLFLAG_RW, 0,
83     "TrustedBSD mac_mls policy controls");
84 
85 static int	mac_mls_label_size = sizeof(struct mac_mls);
86 SYSCTL_INT(_security_mac_mls, OID_AUTO, label_size, CTLFLAG_RD,
87     &mac_mls_label_size, 0, "Size of struct mac_mls");
88 
89 static int	mac_mls_enabled = 1;
90 SYSCTL_INT(_security_mac_mls, OID_AUTO, enabled, CTLFLAG_RW,
91     &mac_mls_enabled, 0, "Enforce MAC/MLS policy");
92 TUNABLE_INT("security.mac.mls.enabled", &mac_mls_enabled);
93 
94 static int	destroyed_not_inited;
95 SYSCTL_INT(_security_mac_mls, OID_AUTO, destroyed_not_inited, CTLFLAG_RD,
96     &destroyed_not_inited, 0, "Count of labels destroyed but not inited");
97 
98 static int	ptys_equal = 0;
99 SYSCTL_INT(_security_mac_mls, OID_AUTO, ptys_equal, CTLFLAG_RW,
100     &ptys_equal, 0, "Label pty devices as mls/equal on create");
101 TUNABLE_INT("security.mac.mls.ptys_equal", &ptys_equal);
102 
103 static int	revocation_enabled = 0;
104 SYSCTL_INT(_security_mac_mls, OID_AUTO, revocation_enabled, CTLFLAG_RW,
105     &revocation_enabled, 0, "Revoke access to objects on relabel");
106 TUNABLE_INT("security.mac.mls.revocation_enabled", &revocation_enabled);
107 
108 static int	max_compartments = MAC_MLS_MAX_COMPARTMENTS;
109 SYSCTL_INT(_security_mac_mls, OID_AUTO, max_compartments, CTLFLAG_RD,
110     &max_compartments, 0, "Maximum compartments the policy supports");
111 
112 static int	mac_mls_slot;
113 #define	SLOT(l)	((struct mac_mls *)LABEL_TO_SLOT((l), mac_mls_slot).l_ptr)
114 
115 MALLOC_DEFINE(M_MACMLS, "mls label", "MAC/MLS labels");
116 
117 static __inline int
118 mls_bit_set_empty(u_char *set) {
119 	int i;
120 
121 	for (i = 0; i < MAC_MLS_MAX_COMPARTMENTS >> 3; i++)
122 		if (set[i] != 0)
123 			return (0);
124 	return (1);
125 }
126 
127 static struct mac_mls *
128 mls_alloc(int flag)
129 {
130 	struct mac_mls *mac_mls;
131 
132 	mac_mls = malloc(sizeof(struct mac_mls), M_MACMLS, M_ZERO | flag);
133 
134 	return (mac_mls);
135 }
136 
137 static void
138 mls_free(struct mac_mls *mac_mls)
139 {
140 
141 	if (mac_mls != NULL)
142 		free(mac_mls, M_MACMLS);
143 	else
144 		atomic_add_int(&destroyed_not_inited, 1);
145 }
146 
147 static int
148 mls_atmostflags(struct mac_mls *mac_mls, int flags)
149 {
150 
151 	if ((mac_mls->mm_flags & flags) != mac_mls->mm_flags)
152 		return (EINVAL);
153 	return (0);
154 }
155 
156 static int
157 mac_mls_dominate_element(struct mac_mls_element *a,
158     struct mac_mls_element *b)
159 {
160 	int bit;
161 
162 	switch (a->mme_type) {
163 	case MAC_MLS_TYPE_EQUAL:
164 	case MAC_MLS_TYPE_HIGH:
165 		return (1);
166 
167 	case MAC_MLS_TYPE_LOW:
168 		switch (b->mme_type) {
169 		case MAC_MLS_TYPE_LEVEL:
170 		case MAC_MLS_TYPE_HIGH:
171 			return (0);
172 
173 		case MAC_MLS_TYPE_EQUAL:
174 		case MAC_MLS_TYPE_LOW:
175 			return (1);
176 
177 		default:
178 			panic("mac_mls_dominate_element: b->mme_type invalid");
179 		}
180 
181 	case MAC_MLS_TYPE_LEVEL:
182 		switch (b->mme_type) {
183 		case MAC_MLS_TYPE_EQUAL:
184 		case MAC_MLS_TYPE_LOW:
185 			return (1);
186 
187 		case MAC_MLS_TYPE_HIGH:
188 			return (0);
189 
190 		case MAC_MLS_TYPE_LEVEL:
191 			for (bit = 1; bit <= MAC_MLS_MAX_COMPARTMENTS; bit++)
192 				if (!MAC_MLS_BIT_TEST(bit,
193 				    a->mme_compartments) &&
194 				    MAC_MLS_BIT_TEST(bit, b->mme_compartments))
195 					return (0);
196 			return (a->mme_level >= b->mme_level);
197 
198 		default:
199 			panic("mac_mls_dominate_element: b->mme_type invalid");
200 		}
201 
202 	default:
203 		panic("mac_mls_dominate_element: a->mme_type invalid");
204 	}
205 
206 	return (0);
207 }
208 
209 static int
210 mac_mls_range_in_range(struct mac_mls *rangea, struct mac_mls *rangeb)
211 {
212 
213 	return (mac_mls_dominate_element(&rangeb->mm_rangehigh,
214 	    &rangea->mm_rangehigh) &&
215 	    mac_mls_dominate_element(&rangea->mm_rangelow,
216 	    &rangeb->mm_rangelow));
217 }
218 
219 static int
220 mac_mls_single_in_range(struct mac_mls *single, struct mac_mls *range)
221 {
222 
223 	KASSERT((single->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
224 	    ("mac_mls_single_in_range: a not single"));
225 	KASSERT((range->mm_flags & MAC_MLS_FLAG_RANGE) != 0,
226 	    ("mac_mls_single_in_range: b not range"));
227 
228 	return (mac_mls_dominate_element(&range->mm_rangehigh,
229 	    &single->mm_single) &&
230 	    mac_mls_dominate_element(&single->mm_single,
231 	    &range->mm_rangelow));
232 
233 	return (1);
234 }
235 
236 static int
237 mac_mls_dominate_single(struct mac_mls *a, struct mac_mls *b)
238 {
239 	KASSERT((a->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
240 	    ("mac_mls_dominate_single: a not single"));
241 	KASSERT((b->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
242 	    ("mac_mls_dominate_single: b not single"));
243 
244 	return (mac_mls_dominate_element(&a->mm_single, &b->mm_single));
245 }
246 
247 static int
248 mac_mls_equal_element(struct mac_mls_element *a, struct mac_mls_element *b)
249 {
250 
251 	if (a->mme_type == MAC_MLS_TYPE_EQUAL ||
252 	    b->mme_type == MAC_MLS_TYPE_EQUAL)
253 		return (1);
254 
255 	return (a->mme_type == b->mme_type && a->mme_level == b->mme_level);
256 }
257 
258 static int
259 mac_mls_equal_single(struct mac_mls *a, struct mac_mls *b)
260 {
261 
262 	KASSERT((a->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
263 	    ("mac_mls_equal_single: a not single"));
264 	KASSERT((b->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
265 	    ("mac_mls_equal_single: b not single"));
266 
267 	return (mac_mls_equal_element(&a->mm_single, &b->mm_single));
268 }
269 
270 static int
271 mac_mls_contains_equal(struct mac_mls *mac_mls)
272 {
273 
274 	if (mac_mls->mm_flags & MAC_MLS_FLAG_SINGLE)
275 		if (mac_mls->mm_single.mme_type == MAC_MLS_TYPE_EQUAL)
276 			return (1);
277 
278 	if (mac_mls->mm_flags & MAC_MLS_FLAG_RANGE) {
279 		if (mac_mls->mm_rangelow.mme_type == MAC_MLS_TYPE_EQUAL)
280 			return (1);
281 		if (mac_mls->mm_rangehigh.mme_type == MAC_MLS_TYPE_EQUAL)
282 			return (1);
283 	}
284 
285 	return (0);
286 }
287 
288 static int
289 mac_mls_subject_equal_ok(struct mac_mls *mac_mls)
290 {
291 
292 	KASSERT((mac_mls->mm_flags & MAC_MLS_FLAGS_BOTH) == MAC_MLS_FLAGS_BOTH,
293 	    ("mac_mls_subject_equal_ok: subject doesn't have both labels"));
294 
295 	/* If the single is EQUAL, it's ok. */
296 	if (mac_mls->mm_single.mme_type == MAC_MLS_TYPE_EQUAL)
297 		return (0);
298 
299 	/* If either range endpoint is EQUAL, it's ok. */
300 	if (mac_mls->mm_rangelow.mme_type == MAC_MLS_TYPE_EQUAL ||
301 	    mac_mls->mm_rangehigh.mme_type == MAC_MLS_TYPE_EQUAL)
302 		return (0);
303 
304 	/* If the range is low-high, it's ok. */
305 	if (mac_mls->mm_rangelow.mme_type == MAC_MLS_TYPE_LOW &&
306 	    mac_mls->mm_rangehigh.mme_type == MAC_MLS_TYPE_HIGH)
307 		return (0);
308 
309 	/* It's not ok. */
310 	return (EPERM);
311 }
312 
313 static int
314 mac_mls_valid(struct mac_mls *mac_mls)
315 {
316 
317 	if (mac_mls->mm_flags & MAC_MLS_FLAG_SINGLE) {
318 		switch (mac_mls->mm_single.mme_type) {
319 		case MAC_MLS_TYPE_LEVEL:
320 			break;
321 
322 		case MAC_MLS_TYPE_EQUAL:
323 		case MAC_MLS_TYPE_HIGH:
324 		case MAC_MLS_TYPE_LOW:
325 			if (mac_mls->mm_single.mme_level != 0 ||
326 			    !MAC_MLS_BIT_SET_EMPTY(
327 			    mac_mls->mm_single.mme_compartments))
328 				return (EINVAL);
329 			break;
330 
331 		default:
332 			return (EINVAL);
333 		}
334 	} else {
335 		if (mac_mls->mm_single.mme_type != MAC_MLS_TYPE_UNDEF)
336 			return (EINVAL);
337 	}
338 
339 	if (mac_mls->mm_flags & MAC_MLS_FLAG_RANGE) {
340 		switch (mac_mls->mm_rangelow.mme_type) {
341 		case MAC_MLS_TYPE_LEVEL:
342 			break;
343 
344 		case MAC_MLS_TYPE_EQUAL:
345 		case MAC_MLS_TYPE_HIGH:
346 		case MAC_MLS_TYPE_LOW:
347 			if (mac_mls->mm_rangelow.mme_level != 0 ||
348 			    !MAC_MLS_BIT_SET_EMPTY(
349 			    mac_mls->mm_rangelow.mme_compartments))
350 				return (EINVAL);
351 			break;
352 
353 		default:
354 			return (EINVAL);
355 		}
356 
357 		switch (mac_mls->mm_rangehigh.mme_type) {
358 		case MAC_MLS_TYPE_LEVEL:
359 			break;
360 
361 		case MAC_MLS_TYPE_EQUAL:
362 		case MAC_MLS_TYPE_HIGH:
363 		case MAC_MLS_TYPE_LOW:
364 			if (mac_mls->mm_rangehigh.mme_level != 0 ||
365 			    !MAC_MLS_BIT_SET_EMPTY(
366 			    mac_mls->mm_rangehigh.mme_compartments))
367 				return (EINVAL);
368 			break;
369 
370 		default:
371 			return (EINVAL);
372 		}
373 		if (!mac_mls_dominate_element(&mac_mls->mm_rangehigh,
374 		    &mac_mls->mm_rangelow))
375 			return (EINVAL);
376 	} else {
377 		if (mac_mls->mm_rangelow.mme_type != MAC_MLS_TYPE_UNDEF ||
378 		    mac_mls->mm_rangehigh.mme_type != MAC_MLS_TYPE_UNDEF)
379 			return (EINVAL);
380 	}
381 
382 	return (0);
383 }
384 
385 static void
386 mac_mls_set_range(struct mac_mls *mac_mls, u_short typelow,
387     u_short levellow, u_char *compartmentslow, u_short typehigh,
388     u_short levelhigh, u_char *compartmentshigh)
389 {
390 
391 	mac_mls->mm_rangelow.mme_type = typelow;
392 	mac_mls->mm_rangelow.mme_level = levellow;
393 	if (compartmentslow != NULL)
394 		memcpy(mac_mls->mm_rangelow.mme_compartments,
395 		    compartmentslow,
396 		    sizeof(mac_mls->mm_rangelow.mme_compartments));
397 	mac_mls->mm_rangehigh.mme_type = typehigh;
398 	mac_mls->mm_rangehigh.mme_level = levelhigh;
399 	if (compartmentshigh != NULL)
400 		memcpy(mac_mls->mm_rangehigh.mme_compartments,
401 		    compartmentshigh,
402 		    sizeof(mac_mls->mm_rangehigh.mme_compartments));
403 	mac_mls->mm_flags |= MAC_MLS_FLAG_RANGE;
404 }
405 
406 static void
407 mac_mls_set_single(struct mac_mls *mac_mls, u_short type, u_short level,
408     u_char *compartments)
409 {
410 
411 	mac_mls->mm_single.mme_type = type;
412 	mac_mls->mm_single.mme_level = level;
413 	if (compartments != NULL)
414 		memcpy(mac_mls->mm_single.mme_compartments, compartments,
415 		    sizeof(mac_mls->mm_single.mme_compartments));
416 	mac_mls->mm_flags |= MAC_MLS_FLAG_SINGLE;
417 }
418 
419 static void
420 mac_mls_copy_range(struct mac_mls *labelfrom, struct mac_mls *labelto)
421 {
422 
423 	KASSERT((labelfrom->mm_flags & MAC_MLS_FLAG_RANGE) != 0,
424 	    ("mac_mls_copy_range: labelfrom not range"));
425 
426 	labelto->mm_rangelow = labelfrom->mm_rangelow;
427 	labelto->mm_rangehigh = labelfrom->mm_rangehigh;
428 	labelto->mm_flags |= MAC_MLS_FLAG_RANGE;
429 }
430 
431 static void
432 mac_mls_copy_single(struct mac_mls *labelfrom, struct mac_mls *labelto)
433 {
434 
435 	KASSERT((labelfrom->mm_flags & MAC_MLS_FLAG_SINGLE) != 0,
436 	    ("mac_mls_copy_single: labelfrom not single"));
437 
438 	labelto->mm_single = labelfrom->mm_single;
439 	labelto->mm_flags |= MAC_MLS_FLAG_SINGLE;
440 }
441 
442 static void
443 mac_mls_copy(struct mac_mls *source, struct mac_mls *dest)
444 {
445 
446 	if (source->mm_flags & MAC_MLS_FLAG_SINGLE)
447 		mac_mls_copy_single(source, dest);
448 	if (source->mm_flags & MAC_MLS_FLAG_RANGE)
449 		mac_mls_copy_range(source, dest);
450 }
451 
452 /*
453  * Policy module operations.
454  */
455 static void
456 mac_mls_destroy(struct mac_policy_conf *conf)
457 {
458 
459 }
460 
461 static void
462 mac_mls_init(struct mac_policy_conf *conf)
463 {
464 
465 }
466 
467 /*
468  * Label operations.
469  */
470 static void
471 mac_mls_init_label(struct label *label)
472 {
473 
474 	SLOT(label) = mls_alloc(M_WAITOK);
475 }
476 
477 static int
478 mac_mls_init_label_waitcheck(struct label *label, int flag)
479 {
480 
481 	SLOT(label) = mls_alloc(flag);
482 	if (SLOT(label) == NULL)
483 		return (ENOMEM);
484 
485 	return (0);
486 }
487 
488 static void
489 mac_mls_destroy_label(struct label *label)
490 {
491 
492 	mls_free(SLOT(label));
493 	SLOT(label) = NULL;
494 }
495 
496 /*
497  * mac_mls_element_to_string() accepts an sbuf and MLS element.  It
498  * converts the MLS element to a string and stores the result in the
499  * sbuf; if there isn't space in the sbuf, -1 is returned.
500  */
501 static int
502 mac_mls_element_to_string(struct sbuf *sb, struct mac_mls_element *element)
503 {
504 	int i, first;
505 
506 	switch (element->mme_type) {
507 	case MAC_MLS_TYPE_HIGH:
508 		return (sbuf_printf(sb, "high"));
509 
510 	case MAC_MLS_TYPE_LOW:
511 		return (sbuf_printf(sb, "low"));
512 
513 	case MAC_MLS_TYPE_EQUAL:
514 		return (sbuf_printf(sb, "equal"));
515 
516 	case MAC_MLS_TYPE_LEVEL:
517 		if (sbuf_printf(sb, "%d", element->mme_level) == -1)
518 			return (-1);
519 
520 		first = 1;
521 		for (i = 1; i <= MAC_MLS_MAX_COMPARTMENTS; i++) {
522 			if (MAC_MLS_BIT_TEST(i, element->mme_compartments)) {
523 				if (first) {
524 					if (sbuf_putc(sb, ':') == -1)
525 						return (-1);
526 					if (sbuf_printf(sb, "%d", i) == -1)
527 						return (-1);
528 					first = 0;
529 				} else {
530 					if (sbuf_printf(sb, "+%d", i) == -1)
531 						return (-1);
532 				}
533 			}
534 		}
535 		return (0);
536 
537 	default:
538 		panic("mac_mls_element_to_string: invalid type (%d)",
539 		    element->mme_type);
540 	}
541 }
542 
543 /*
544  * mac_mls_to_string() converts an MLS label to a string, placing the
545  * results in the passed string buffer.  It returns 0 on success,
546  * or EINVAL if there isn't room in the buffer.  The size of the
547  * string appended, leaving out the nul termination, is returned to
548  * the caller via *caller_len.  Eventually, we should expose the
549  * sbuf to the caller rather than using C strings at this layer.
550  */
551 static int
552 mac_mls_to_string(char *string, size_t size, size_t *caller_len,
553     struct mac_mls *mac_mls)
554 {
555 	struct sbuf sb;
556 
557 	sbuf_new(&sb, string, size, SBUF_FIXEDLEN);
558 
559 	if (mac_mls->mm_flags & MAC_MLS_FLAG_SINGLE) {
560 		if (mac_mls_element_to_string(&sb, &mac_mls->mm_single)
561 		    == -1)
562 			return (EINVAL);
563 	}
564 
565 	if (mac_mls->mm_flags & MAC_MLS_FLAG_RANGE) {
566 		if (sbuf_putc(&sb, '(') == -1)
567 			return (EINVAL);
568 
569 		if (mac_mls_element_to_string(&sb, &mac_mls->mm_rangelow)
570 		    == -1)
571 			return (EINVAL);
572 
573 		if (sbuf_putc(&sb, '-') == -1)
574 			return (EINVAL);
575 
576 		if (mac_mls_element_to_string(&sb, &mac_mls->mm_rangehigh)
577 		    == -1)
578 			return (EINVAL);
579 
580 		if (sbuf_putc(&sb, ')') == -1)
581 			return (EINVAL);
582 	}
583 
584 	sbuf_finish(&sb);
585 	*caller_len = strlen(string);
586 	return (0);
587 }
588 
589 static int
590 mac_mls_externalize_label(struct label *label, char *element_name,
591     char *element_data, size_t size, size_t *len, int *claimed)
592 {
593 	struct mac_mls *mac_mls;
594 	int error;
595 
596 	if (strcmp(MAC_MLS_LABEL_NAME, element_name) != 0)
597 		return (0);
598 
599 	(*claimed)++;
600 
601 	mac_mls = SLOT(label);
602 
603 	error = mac_mls_to_string(element_data, size, len, mac_mls);
604 	if (error)
605 		return (error);
606 
607 	return (0);
608 }
609 
610 static int
611 mac_mls_parse_element(struct mac_mls_element *element, char *string)
612 {
613 	char *compartment, *end, *level;
614 	int value;
615 
616 	if (strcmp(string, "high") == 0 ||
617 	    strcmp(string, "hi") == 0) {
618 		element->mme_type = MAC_MLS_TYPE_HIGH;
619 		element->mme_level = MAC_MLS_TYPE_UNDEF;
620 	} else if (strcmp(string, "low") == 0 ||
621 	    strcmp(string, "lo") == 0) {
622 		element->mme_type = MAC_MLS_TYPE_LOW;
623 		element->mme_level = MAC_MLS_TYPE_UNDEF;
624 	} else if (strcmp(string, "equal") == 0 ||
625 	    strcmp(string, "eq") == 0) {
626 		element->mme_type = MAC_MLS_TYPE_EQUAL;
627 		element->mme_level = MAC_MLS_TYPE_UNDEF;
628 	} else {
629 		element->mme_type = MAC_MLS_TYPE_LEVEL;
630 
631 		/*
632 		 * Numeric level piece of the element.
633 		 */
634 		level = strsep(&string, ":");
635 		value = strtol(level, &end, 10);
636 		if (end == level || *end != '\0')
637 			return (EINVAL);
638 		if (value < 0 || value > 65535)
639 			return (EINVAL);
640 		element->mme_level = value;
641 
642 		/*
643 		 * Optional compartment piece of the element.  If none
644 		 * are included, we assume that the label has no
645 		 * compartments.
646 		 */
647 		if (string == NULL)
648 			return (0);
649 		if (*string == '\0')
650 			return (0);
651 
652 		while ((compartment = strsep(&string, "+")) != NULL) {
653 			value = strtol(compartment, &end, 10);
654 			if (compartment == end || *end != '\0')
655 				return (EINVAL);
656 			if (value < 1 || value > MAC_MLS_MAX_COMPARTMENTS)
657 				return (EINVAL);
658 			MAC_MLS_BIT_SET(value, element->mme_compartments);
659 		}
660 	}
661 
662 	return (0);
663 }
664 
665 /*
666  * Note: destructively consumes the string, make a local copy before
667  * calling if that's a problem.
668  */
669 static int
670 mac_mls_parse(struct mac_mls *mac_mls, char *string)
671 {
672 	char *rangehigh, *rangelow, *single;
673 	int error;
674 
675 	single = strsep(&string, "(");
676 	if (*single == '\0')
677 		single = NULL;
678 
679 	if (string != NULL) {
680 		rangelow = strsep(&string, "-");
681 		if (string == NULL)
682 			return (EINVAL);
683 		rangehigh = strsep(&string, ")");
684 		if (string == NULL)
685 			return (EINVAL);
686 		if (*string != '\0')
687 			return (EINVAL);
688 	} else {
689 		rangelow = NULL;
690 		rangehigh = NULL;
691 	}
692 
693 	KASSERT((rangelow != NULL && rangehigh != NULL) ||
694 	    (rangelow == NULL && rangehigh == NULL),
695 	    ("mac_mls_parse: range mismatch"));
696 
697 	bzero(mac_mls, sizeof(*mac_mls));
698 	if (single != NULL) {
699 		error = mac_mls_parse_element(&mac_mls->mm_single, single);
700 		if (error)
701 			return (error);
702 		mac_mls->mm_flags |= MAC_MLS_FLAG_SINGLE;
703 	}
704 
705 	if (rangelow != NULL) {
706 		error = mac_mls_parse_element(&mac_mls->mm_rangelow,
707 		    rangelow);
708 		if (error)
709 			return (error);
710 		error = mac_mls_parse_element(&mac_mls->mm_rangehigh,
711 		    rangehigh);
712 		if (error)
713 			return (error);
714 		mac_mls->mm_flags |= MAC_MLS_FLAG_RANGE;
715 	}
716 
717 	error = mac_mls_valid(mac_mls);
718 	if (error)
719 		return (error);
720 
721 	return (0);
722 }
723 
724 static int
725 mac_mls_internalize_label(struct label *label, char *element_name,
726     char *element_data, int *claimed)
727 {
728 	struct mac_mls *mac_mls, mac_mls_temp;
729 	int error;
730 
731 	if (strcmp(MAC_MLS_LABEL_NAME, element_name) != 0)
732 		return (0);
733 
734 	(*claimed)++;
735 
736 	error = mac_mls_parse(&mac_mls_temp, element_data);
737 	if (error)
738 		return (error);
739 
740 	mac_mls = SLOT(label);
741 	*mac_mls = mac_mls_temp;
742 
743 	return (0);
744 }
745 
746 static void
747 mac_mls_copy_label(struct label *src, struct label *dest)
748 {
749 
750 	*SLOT(dest) = *SLOT(src);
751 }
752 
753 /*
754  * Labeling event operations: file system objects, and things that look
755  * a lot like file system objects.
756  */
757 static void
758 mac_mls_create_devfs_device(struct mount *mp, dev_t dev,
759     struct devfs_dirent *devfs_dirent, struct label *label)
760 {
761 	struct mac_mls *mac_mls;
762 	int mls_type;
763 
764 	mac_mls = SLOT(label);
765 	if (strcmp(dev->si_name, "null") == 0 ||
766 	    strcmp(dev->si_name, "zero") == 0 ||
767 	    strcmp(dev->si_name, "random") == 0 ||
768 	    strncmp(dev->si_name, "fd/", strlen("fd/")) == 0)
769 		mls_type = MAC_MLS_TYPE_EQUAL;
770 	else if (strcmp(dev->si_name, "kmem") == 0 ||
771 	    strcmp(dev->si_name, "mem") == 0)
772 		mls_type = MAC_MLS_TYPE_HIGH;
773 	else if (ptys_equal &&
774 	    (strncmp(dev->si_name, "ttyp", strlen("ttyp")) == 0 ||
775 	    strncmp(dev->si_name, "ptyp", strlen("ptyp")) == 0))
776 		mls_type = MAC_MLS_TYPE_EQUAL;
777 	else
778 		mls_type = MAC_MLS_TYPE_LOW;
779 	mac_mls_set_single(mac_mls, mls_type, 0, NULL);
780 }
781 
782 static void
783 mac_mls_create_devfs_directory(struct mount *mp, char *dirname,
784     int dirnamelen, struct devfs_dirent *devfs_dirent, struct label *label)
785 {
786 	struct mac_mls *mac_mls;
787 
788 	mac_mls = SLOT(label);
789 	mac_mls_set_single(mac_mls, MAC_MLS_TYPE_LOW, 0, NULL);
790 }
791 
792 static void
793 mac_mls_create_devfs_symlink(struct ucred *cred, struct mount *mp,
794     struct devfs_dirent *dd, struct label *ddlabel, struct devfs_dirent *de,
795     struct label *delabel)
796 {
797 	struct mac_mls *source, *dest;
798 
799 	source = SLOT(&cred->cr_label);
800 	dest = SLOT(delabel);
801 
802 	mac_mls_copy_single(source, dest);
803 }
804 
805 static void
806 mac_mls_create_mount(struct ucred *cred, struct mount *mp,
807     struct label *mntlabel, struct label *fslabel)
808 {
809 	struct mac_mls *source, *dest;
810 
811 	source = SLOT(&cred->cr_label);
812 	dest = SLOT(mntlabel);
813 	mac_mls_copy_single(source, dest);
814 	dest = SLOT(fslabel);
815 	mac_mls_copy_single(source, dest);
816 }
817 
818 static void
819 mac_mls_create_root_mount(struct ucred *cred, struct mount *mp,
820     struct label *mntlabel, struct label *fslabel)
821 {
822 	struct mac_mls *mac_mls;
823 
824 	/* Always mount root as high integrity. */
825 	mac_mls = SLOT(fslabel);
826 	mac_mls_set_single(mac_mls, MAC_MLS_TYPE_LOW, 0, NULL);
827 	mac_mls = SLOT(mntlabel);
828 	mac_mls_set_single(mac_mls, MAC_MLS_TYPE_LOW, 0, NULL);
829 }
830 
831 static void
832 mac_mls_relabel_vnode(struct ucred *cred, struct vnode *vp,
833     struct label *vnodelabel, struct label *label)
834 {
835 	struct mac_mls *source, *dest;
836 
837 	source = SLOT(label);
838 	dest = SLOT(vnodelabel);
839 
840 	mac_mls_copy(source, dest);
841 }
842 
843 static void
844 mac_mls_update_devfsdirent(struct mount *mp,
845     struct devfs_dirent *devfs_dirent, struct label *direntlabel,
846     struct vnode *vp, struct label *vnodelabel)
847 {
848 	struct mac_mls *source, *dest;
849 
850 	source = SLOT(vnodelabel);
851 	dest = SLOT(direntlabel);
852 
853 	mac_mls_copy_single(source, dest);
854 }
855 
856 static void
857 mac_mls_associate_vnode_devfs(struct mount *mp, struct label *fslabel,
858     struct devfs_dirent *de, struct label *delabel, struct vnode *vp,
859     struct label *vlabel)
860 {
861 	struct mac_mls *source, *dest;
862 
863 	source = SLOT(delabel);
864 	dest = SLOT(vlabel);
865 
866 	mac_mls_copy_single(source, dest);
867 }
868 
869 static int
870 mac_mls_associate_vnode_extattr(struct mount *mp, struct label *fslabel,
871     struct vnode *vp, struct label *vlabel)
872 {
873 	struct mac_mls temp, *source, *dest;
874 	int buflen, error;
875 
876 	source = SLOT(fslabel);
877 	dest = SLOT(vlabel);
878 
879 	buflen = sizeof(temp);
880 	bzero(&temp, buflen);
881 
882 	error = vn_extattr_get(vp, IO_NODELOCKED, MAC_MLS_EXTATTR_NAMESPACE,
883 	    MAC_MLS_EXTATTR_NAME, &buflen, (char *) &temp, curthread);
884 	if (error == ENOATTR || error == EOPNOTSUPP) {
885 		/* Fall back to the fslabel. */
886 		mac_mls_copy_single(source, dest);
887 		return (0);
888 	} else if (error)
889 		return (error);
890 
891 	if (buflen != sizeof(temp)) {
892 		printf("mac_mls_associate_vnode_extattr: bad size %d\n",
893 		    buflen);
894 		return (EPERM);
895 	}
896 	if (mac_mls_valid(&temp) != 0) {
897 		printf("mac_mls_associate_vnode_extattr: invalid\n");
898 		return (EPERM);
899 	}
900 	if ((temp.mm_flags & MAC_MLS_FLAGS_BOTH) != MAC_MLS_FLAG_SINGLE) {
901 		printf("mac_mls_associated_vnode_extattr: not single\n");
902 		return (EPERM);
903 	}
904 
905 	mac_mls_copy_single(&temp, dest);
906 	return (0);
907 }
908 
909 static void
910 mac_mls_associate_vnode_singlelabel(struct mount *mp,
911     struct label *fslabel, struct vnode *vp, struct label *vlabel)
912 {
913 	struct mac_mls *source, *dest;
914 
915 	source = SLOT(fslabel);
916 	dest = SLOT(vlabel);
917 
918 	mac_mls_copy_single(source, dest);
919 }
920 
921 static int
922 mac_mls_create_vnode_extattr(struct ucred *cred, struct mount *mp,
923     struct label *fslabel, struct vnode *dvp, struct label *dlabel,
924     struct vnode *vp, struct label *vlabel, struct componentname *cnp)
925 {
926 	struct mac_mls *source, *dest, temp;
927 	size_t buflen;
928 	int error;
929 
930 	buflen = sizeof(temp);
931 	bzero(&temp, buflen);
932 
933 	source = SLOT(&cred->cr_label);
934 	dest = SLOT(vlabel);
935 	mac_mls_copy_single(source, &temp);
936 
937 	error = vn_extattr_set(vp, IO_NODELOCKED, MAC_MLS_EXTATTR_NAMESPACE,
938 	    MAC_MLS_EXTATTR_NAME, buflen, (char *) &temp, curthread);
939 	if (error == 0)
940 		mac_mls_copy_single(source, dest);
941 	return (error);
942 }
943 
944 static int
945 mac_mls_setlabel_vnode_extattr(struct ucred *cred, struct vnode *vp,
946     struct label *vlabel, struct label *intlabel)
947 {
948 	struct mac_mls *source, temp;
949 	size_t buflen;
950 	int error;
951 
952 	buflen = sizeof(temp);
953 	bzero(&temp, buflen);
954 
955 	source = SLOT(intlabel);
956 	if ((source->mm_flags & MAC_MLS_FLAG_SINGLE) == 0)
957 		return (0);
958 
959 	mac_mls_copy_single(source, &temp);
960 
961 	error = vn_extattr_set(vp, IO_NODELOCKED, MAC_MLS_EXTATTR_NAMESPACE,
962 	    MAC_MLS_EXTATTR_NAME, buflen, (char *) &temp, curthread);
963 	return (error);
964 }
965 
966 /*
967  * Labeling event operations: IPC object.
968  */
969 static void
970 mac_mls_create_mbuf_from_socket(struct socket *so, struct label *socketlabel,
971     struct mbuf *m, struct label *mbuflabel)
972 {
973 	struct mac_mls *source, *dest;
974 
975 	source = SLOT(socketlabel);
976 	dest = SLOT(mbuflabel);
977 
978 	mac_mls_copy_single(source, dest);
979 }
980 
981 static void
982 mac_mls_create_socket(struct ucred *cred, struct socket *socket,
983     struct label *socketlabel)
984 {
985 	struct mac_mls *source, *dest;
986 
987 	source = SLOT(&cred->cr_label);
988 	dest = SLOT(socketlabel);
989 
990 	mac_mls_copy_single(source, dest);
991 }
992 
993 static void
994 mac_mls_create_pipe(struct ucred *cred, struct pipe *pipe,
995     struct label *pipelabel)
996 {
997 	struct mac_mls *source, *dest;
998 
999 	source = SLOT(&cred->cr_label);
1000 	dest = SLOT(pipelabel);
1001 
1002 	mac_mls_copy_single(source, dest);
1003 }
1004 
1005 static void
1006 mac_mls_create_socket_from_socket(struct socket *oldsocket,
1007     struct label *oldsocketlabel, struct socket *newsocket,
1008     struct label *newsocketlabel)
1009 {
1010 	struct mac_mls *source, *dest;
1011 
1012 	source = SLOT(oldsocketlabel);
1013 	dest = SLOT(newsocketlabel);
1014 
1015 	mac_mls_copy_single(source, dest);
1016 }
1017 
1018 static void
1019 mac_mls_relabel_socket(struct ucred *cred, struct socket *socket,
1020     struct label *socketlabel, struct label *newlabel)
1021 {
1022 	struct mac_mls *source, *dest;
1023 
1024 	source = SLOT(newlabel);
1025 	dest = SLOT(socketlabel);
1026 
1027 	mac_mls_copy(source, dest);
1028 }
1029 
1030 static void
1031 mac_mls_relabel_pipe(struct ucred *cred, struct pipe *pipe,
1032     struct label *pipelabel, struct label *newlabel)
1033 {
1034 	struct mac_mls *source, *dest;
1035 
1036 	source = SLOT(newlabel);
1037 	dest = SLOT(pipelabel);
1038 
1039 	mac_mls_copy(source, dest);
1040 }
1041 
1042 static void
1043 mac_mls_set_socket_peer_from_mbuf(struct mbuf *mbuf, struct label *mbuflabel,
1044     struct socket *socket, struct label *socketpeerlabel)
1045 {
1046 	struct mac_mls *source, *dest;
1047 
1048 	source = SLOT(mbuflabel);
1049 	dest = SLOT(socketpeerlabel);
1050 
1051 	mac_mls_copy_single(source, dest);
1052 }
1053 
1054 /*
1055  * Labeling event operations: network objects.
1056  */
1057 static void
1058 mac_mls_set_socket_peer_from_socket(struct socket *oldsocket,
1059     struct label *oldsocketlabel, struct socket *newsocket,
1060     struct label *newsocketpeerlabel)
1061 {
1062 	struct mac_mls *source, *dest;
1063 
1064 	source = SLOT(oldsocketlabel);
1065 	dest = SLOT(newsocketpeerlabel);
1066 
1067 	mac_mls_copy_single(source, dest);
1068 }
1069 
1070 static void
1071 mac_mls_create_bpfdesc(struct ucred *cred, struct bpf_d *bpf_d,
1072     struct label *bpflabel)
1073 {
1074 	struct mac_mls *source, *dest;
1075 
1076 	source = SLOT(&cred->cr_label);
1077 	dest = SLOT(bpflabel);
1078 
1079 	mac_mls_copy_single(source, dest);
1080 }
1081 
1082 static void
1083 mac_mls_create_ifnet(struct ifnet *ifnet, struct label *ifnetlabel)
1084 {
1085 	struct mac_mls *dest;
1086 	int type;
1087 
1088 	dest = SLOT(ifnetlabel);
1089 
1090 	if (ifnet->if_type == IFT_LOOP)
1091 		type = MAC_MLS_TYPE_EQUAL;
1092 	else
1093 		type = MAC_MLS_TYPE_LOW;
1094 
1095 	mac_mls_set_single(dest, type, 0, NULL);
1096 	mac_mls_set_range(dest, type, 0, NULL, type, 0, NULL);
1097 }
1098 
1099 static void
1100 mac_mls_create_ipq(struct mbuf *fragment, struct label *fragmentlabel,
1101     struct ipq *ipq, struct label *ipqlabel)
1102 {
1103 	struct mac_mls *source, *dest;
1104 
1105 	source = SLOT(fragmentlabel);
1106 	dest = SLOT(ipqlabel);
1107 
1108 	mac_mls_copy_single(source, dest);
1109 }
1110 
1111 static void
1112 mac_mls_create_datagram_from_ipq(struct ipq *ipq, struct label *ipqlabel,
1113     struct mbuf *datagram, struct label *datagramlabel)
1114 {
1115 	struct mac_mls *source, *dest;
1116 
1117 	source = SLOT(ipqlabel);
1118 	dest = SLOT(datagramlabel);
1119 
1120 	/* Just use the head, since we require them all to match. */
1121 	mac_mls_copy_single(source, dest);
1122 }
1123 
1124 static void
1125 mac_mls_create_fragment(struct mbuf *datagram, struct label *datagramlabel,
1126     struct mbuf *fragment, struct label *fragmentlabel)
1127 {
1128 	struct mac_mls *source, *dest;
1129 
1130 	source = SLOT(datagramlabel);
1131 	dest = SLOT(fragmentlabel);
1132 
1133 	mac_mls_copy_single(source, dest);
1134 }
1135 
1136 static void
1137 mac_mls_create_mbuf_from_mbuf(struct mbuf *oldmbuf,
1138     struct label *oldmbuflabel, struct mbuf *newmbuf,
1139     struct label *newmbuflabel)
1140 {
1141 	struct mac_mls *source, *dest;
1142 
1143 	source = SLOT(oldmbuflabel);
1144 	dest = SLOT(newmbuflabel);
1145 
1146 	/*
1147 	 * Because the source mbuf may not yet have been "created",
1148 	 * just initialized, we do a conditional copy.  Since we don't
1149 	 * allow mbufs to have ranges, do a KASSERT to make sure that
1150 	 * doesn't happen.
1151 	 */
1152 	KASSERT((source->mm_flags & MAC_MLS_FLAG_RANGE) == 0,
1153 	    ("mac_mls_create_mbuf_from_mbuf: source mbuf has range"));
1154 	mac_mls_copy(source, dest);
1155 }
1156 
1157 static void
1158 mac_mls_create_mbuf_linklayer(struct ifnet *ifnet, struct label *ifnetlabel,
1159     struct mbuf *mbuf, struct label *mbuflabel)
1160 {
1161 	struct mac_mls *dest;
1162 
1163 	dest = SLOT(mbuflabel);
1164 
1165 	mac_mls_set_single(dest, MAC_MLS_TYPE_EQUAL, 0, NULL);
1166 }
1167 
1168 static void
1169 mac_mls_create_mbuf_from_bpfdesc(struct bpf_d *bpf_d, struct label *bpflabel,
1170     struct mbuf *mbuf, struct label *mbuflabel)
1171 {
1172 	struct mac_mls *source, *dest;
1173 
1174 	source = SLOT(bpflabel);
1175 	dest = SLOT(mbuflabel);
1176 
1177 	mac_mls_copy_single(source, dest);
1178 }
1179 
1180 static void
1181 mac_mls_create_mbuf_from_ifnet(struct ifnet *ifnet, struct label *ifnetlabel,
1182     struct mbuf *m, struct label *mbuflabel)
1183 {
1184 	struct mac_mls *source, *dest;
1185 
1186 	source = SLOT(ifnetlabel);
1187 	dest = SLOT(mbuflabel);
1188 
1189 	mac_mls_copy_single(source, dest);
1190 }
1191 
1192 static void
1193 mac_mls_create_mbuf_multicast_encap(struct mbuf *oldmbuf,
1194     struct label *oldmbuflabel, struct ifnet *ifnet, struct label *ifnetlabel,
1195     struct mbuf *newmbuf, struct label *newmbuflabel)
1196 {
1197 	struct mac_mls *source, *dest;
1198 
1199 	source = SLOT(oldmbuflabel);
1200 	dest = SLOT(newmbuflabel);
1201 
1202 	mac_mls_copy_single(source, dest);
1203 }
1204 
1205 static void
1206 mac_mls_create_mbuf_netlayer(struct mbuf *oldmbuf, struct label *oldmbuflabel,
1207     struct mbuf *newmbuf, struct label *newmbuflabel)
1208 {
1209 	struct mac_mls *source, *dest;
1210 
1211 	source = SLOT(oldmbuflabel);
1212 	dest = SLOT(newmbuflabel);
1213 
1214 	mac_mls_copy_single(source, dest);
1215 }
1216 
1217 static int
1218 mac_mls_fragment_match(struct mbuf *fragment, struct label *fragmentlabel,
1219     struct ipq *ipq, struct label *ipqlabel)
1220 {
1221 	struct mac_mls *a, *b;
1222 
1223 	a = SLOT(ipqlabel);
1224 	b = SLOT(fragmentlabel);
1225 
1226 	return (mac_mls_equal_single(a, b));
1227 }
1228 
1229 static void
1230 mac_mls_relabel_ifnet(struct ucred *cred, struct ifnet *ifnet,
1231     struct label *ifnetlabel, struct label *newlabel)
1232 {
1233 	struct mac_mls *source, *dest;
1234 
1235 	source = SLOT(newlabel);
1236 	dest = SLOT(ifnetlabel);
1237 
1238 	mac_mls_copy(source, dest);
1239 }
1240 
1241 static void
1242 mac_mls_update_ipq(struct mbuf *fragment, struct label *fragmentlabel,
1243     struct ipq *ipq, struct label *ipqlabel)
1244 {
1245 
1246 	/* NOOP: we only accept matching labels, so no need to update */
1247 }
1248 
1249 /*
1250  * Labeling event operations: processes.
1251  */
1252 static void
1253 mac_mls_create_cred(struct ucred *cred_parent, struct ucred *cred_child)
1254 {
1255 	struct mac_mls *source, *dest;
1256 
1257 	source = SLOT(&cred_parent->cr_label);
1258 	dest = SLOT(&cred_child->cr_label);
1259 
1260 	mac_mls_copy_single(source, dest);
1261 	mac_mls_copy_range(source, dest);
1262 }
1263 
1264 static void
1265 mac_mls_create_proc0(struct ucred *cred)
1266 {
1267 	struct mac_mls *dest;
1268 
1269 	dest = SLOT(&cred->cr_label);
1270 
1271 	mac_mls_set_single(dest, MAC_MLS_TYPE_EQUAL, 0, NULL);
1272 	mac_mls_set_range(dest, MAC_MLS_TYPE_LOW, 0, NULL, MAC_MLS_TYPE_HIGH,
1273 	    0, NULL);
1274 }
1275 
1276 static void
1277 mac_mls_create_proc1(struct ucred *cred)
1278 {
1279 	struct mac_mls *dest;
1280 
1281 	dest = SLOT(&cred->cr_label);
1282 
1283 	mac_mls_set_single(dest, MAC_MLS_TYPE_LOW, 0, NULL);
1284 	mac_mls_set_range(dest, MAC_MLS_TYPE_LOW, 0, NULL, MAC_MLS_TYPE_HIGH,
1285 	    0, NULL);
1286 }
1287 
1288 static void
1289 mac_mls_relabel_cred(struct ucred *cred, struct label *newlabel)
1290 {
1291 	struct mac_mls *source, *dest;
1292 
1293 	source = SLOT(newlabel);
1294 	dest = SLOT(&cred->cr_label);
1295 
1296 	mac_mls_copy(source, dest);
1297 }
1298 
1299 /*
1300  * Access control checks.
1301  */
1302 static int
1303 mac_mls_check_bpfdesc_receive(struct bpf_d *bpf_d, struct label *bpflabel,
1304      struct ifnet *ifnet, struct label *ifnetlabel)
1305 {
1306 	struct mac_mls *a, *b;
1307 
1308 	if (!mac_mls_enabled)
1309 		return (0);
1310 
1311 	a = SLOT(bpflabel);
1312 	b = SLOT(ifnetlabel);
1313 
1314 	if (mac_mls_equal_single(a, b))
1315 		return (0);
1316 	return (EACCES);
1317 }
1318 
1319 static int
1320 mac_mls_check_cred_relabel(struct ucred *cred, struct label *newlabel)
1321 {
1322 	struct mac_mls *subj, *new;
1323 	int error;
1324 
1325 	subj = SLOT(&cred->cr_label);
1326 	new = SLOT(newlabel);
1327 
1328 	/*
1329 	 * If there is an MLS label update for the credential, it may be
1330 	 * an update of single, range, or both.
1331 	 */
1332 	error = mls_atmostflags(new, MAC_MLS_FLAGS_BOTH);
1333 	if (error)
1334 		return (error);
1335 
1336 	/*
1337 	 * If the MLS label is to be changed, authorize as appropriate.
1338 	 */
1339 	if (new->mm_flags & MAC_MLS_FLAGS_BOTH) {
1340 		/*
1341 		 * If the change request modifies both the MLS label single
1342 		 * and range, check that the new single will be in the
1343 		 * new range.
1344 		 */
1345 		if ((new->mm_flags & MAC_MLS_FLAGS_BOTH) ==
1346 		    MAC_MLS_FLAGS_BOTH &&
1347 		    !mac_mls_single_in_range(new, new))
1348 			return (EINVAL);
1349 
1350 		/*
1351 		 * To change the MLS single label on a credential, the
1352 		 * new single label must be in the current range.
1353 		 */
1354 		if (new->mm_flags & MAC_MLS_FLAG_SINGLE &&
1355 		    !mac_mls_single_in_range(new, subj))
1356 			return (EPERM);
1357 
1358 		/*
1359 		 * To change the MLS range label on a credential, the
1360 		 * new range must be in the current range.
1361 		 */
1362 		if (new->mm_flags & MAC_MLS_FLAG_RANGE &&
1363 		    !mac_mls_range_in_range(new, subj))
1364 			return (EPERM);
1365 
1366 		/*
1367 		 * To have EQUAL in any component of the new credential
1368 		 * MLS label, the subject must already have EQUAL in
1369 		 * their label.
1370 		 */
1371 		if (mac_mls_contains_equal(new)) {
1372 			error = mac_mls_subject_equal_ok(subj);
1373 			if (error)
1374 				return (error);
1375 		}
1376 	}
1377 
1378 	return (0);
1379 }
1380 
1381 static int
1382 mac_mls_check_cred_visible(struct ucred *u1, struct ucred *u2)
1383 {
1384 	struct mac_mls *subj, *obj;
1385 
1386 	if (!mac_mls_enabled)
1387 		return (0);
1388 
1389 	subj = SLOT(&u1->cr_label);
1390 	obj = SLOT(&u2->cr_label);
1391 
1392 	/* XXX: range */
1393 	if (!mac_mls_dominate_single(subj, obj))
1394 		return (ESRCH);
1395 
1396 	return (0);
1397 }
1398 
1399 static int
1400 mac_mls_check_ifnet_relabel(struct ucred *cred, struct ifnet *ifnet,
1401     struct label *ifnetlabel, struct label *newlabel)
1402 {
1403 	struct mac_mls *subj, *new;
1404 	int error;
1405 
1406 	subj = SLOT(&cred->cr_label);
1407 	new = SLOT(newlabel);
1408 
1409 	/*
1410 	 * If there is an MLS label update for the interface, it may
1411 	 * be an update of single, range, or both.
1412 	 */
1413 	error = mls_atmostflags(new, MAC_MLS_FLAGS_BOTH);
1414 	if (error)
1415 		return (error);
1416 
1417 	/*
1418 	 * If the MLS label is to be changed, authorize as appropriate.
1419 	 */
1420 	if (new->mm_flags & MAC_MLS_FLAGS_BOTH) {
1421 		/*
1422 		 * Rely on traditional superuser status for the MLS
1423 		 * interface relabel requirements.  XXX: This will go
1424 		 * away.
1425 		 */
1426 		error = suser_cred(cred, 0);
1427 		if (error)
1428 			return (EPERM);
1429 
1430 		/*
1431 		 * XXXMAC: Additional consistency tests regarding the single
1432 		 * and the range of the new label might be performed here.
1433 		 */
1434 	}
1435 
1436 	return (0);
1437 }
1438 
1439 static int
1440 mac_mls_check_ifnet_transmit(struct ifnet *ifnet, struct label *ifnetlabel,
1441     struct mbuf *m, struct label *mbuflabel)
1442 {
1443 	struct mac_mls *p, *i;
1444 
1445 	if (!mac_mls_enabled)
1446 		return (0);
1447 
1448 	p = SLOT(mbuflabel);
1449 	i = SLOT(ifnetlabel);
1450 
1451 	return (mac_mls_single_in_range(p, i) ? 0 : EACCES);
1452 }
1453 
1454 static int
1455 mac_mls_check_mount_stat(struct ucred *cred, struct mount *mp,
1456     struct label *mntlabel)
1457 {
1458 	struct mac_mls *subj, *obj;
1459 
1460 	if (!mac_mls_enabled)
1461 		return (0);
1462 
1463 	subj = SLOT(&cred->cr_label);
1464 	obj = SLOT(mntlabel);
1465 
1466 	if (!mac_mls_dominate_single(subj, obj))
1467 		return (EACCES);
1468 
1469 	return (0);
1470 }
1471 
1472 static int
1473 mac_mls_check_pipe_ioctl(struct ucred *cred, struct pipe *pipe,
1474     struct label *pipelabel, unsigned long cmd, void /* caddr_t */ *data)
1475 {
1476 
1477 	if(!mac_mls_enabled)
1478 		return (0);
1479 
1480 	/* XXX: This will be implemented soon... */
1481 
1482 	return (0);
1483 }
1484 
1485 static int
1486 mac_mls_check_pipe_poll(struct ucred *cred, struct pipe *pipe,
1487     struct label *pipelabel)
1488 {
1489 	struct mac_mls *subj, *obj;
1490 
1491 	if (!mac_mls_enabled)
1492 		return (0);
1493 
1494 	subj = SLOT(&cred->cr_label);
1495 	obj = SLOT((pipelabel));
1496 
1497 	if (!mac_mls_dominate_single(subj, obj))
1498 		return (EACCES);
1499 
1500 	return (0);
1501 }
1502 
1503 static int
1504 mac_mls_check_pipe_read(struct ucred *cred, struct pipe *pipe,
1505     struct label *pipelabel)
1506 {
1507 	struct mac_mls *subj, *obj;
1508 
1509 	if (!mac_mls_enabled)
1510 		return (0);
1511 
1512 	subj = SLOT(&cred->cr_label);
1513 	obj = SLOT((pipelabel));
1514 
1515 	if (!mac_mls_dominate_single(subj, obj))
1516 		return (EACCES);
1517 
1518 	return (0);
1519 }
1520 
1521 static int
1522 mac_mls_check_pipe_relabel(struct ucred *cred, struct pipe *pipe,
1523     struct label *pipelabel, struct label *newlabel)
1524 {
1525 	struct mac_mls *subj, *obj, *new;
1526 	int error;
1527 
1528 	new = SLOT(newlabel);
1529 	subj = SLOT(&cred->cr_label);
1530 	obj = SLOT(pipelabel);
1531 
1532 	/*
1533 	 * If there is an MLS label update for a pipe, it must be a
1534 	 * single update.
1535 	 */
1536 	error = mls_atmostflags(new, MAC_MLS_FLAG_SINGLE);
1537 	if (error)
1538 		return (error);
1539 
1540 	/*
1541 	 * To perform a relabel of a pipe (MLS label or not), MLS must
1542 	 * authorize the relabel.
1543 	 */
1544 	if (!mac_mls_single_in_range(obj, subj))
1545 		return (EPERM);
1546 
1547 	/*
1548 	 * If the MLS label is to be changed, authorize as appropriate.
1549 	 */
1550 	if (new->mm_flags & MAC_MLS_FLAG_SINGLE) {
1551 		/*
1552 		 * To change the MLS label on a pipe, the new pipe label
1553 		 * must be in the subject range.
1554 		 */
1555 		if (!mac_mls_single_in_range(new, subj))
1556 			return (EPERM);
1557 
1558 		/*
1559 		 * To change the MLS label on a pipe to be EQUAL, the
1560 		 * subject must have appropriate privilege.
1561 		 */
1562 		if (mac_mls_contains_equal(new)) {
1563 			error = mac_mls_subject_equal_ok(subj);
1564 			if (error)
1565 				return (error);
1566 		}
1567 	}
1568 
1569 	return (0);
1570 }
1571 
1572 static int
1573 mac_mls_check_pipe_stat(struct ucred *cred, struct pipe *pipe,
1574     struct label *pipelabel)
1575 {
1576 	struct mac_mls *subj, *obj;
1577 
1578 	if (!mac_mls_enabled)
1579 		return (0);
1580 
1581 	subj = SLOT(&cred->cr_label);
1582 	obj = SLOT((pipelabel));
1583 
1584 	if (!mac_mls_dominate_single(subj, obj))
1585 		return (EACCES);
1586 
1587 	return (0);
1588 }
1589 
1590 static int
1591 mac_mls_check_pipe_write(struct ucred *cred, struct pipe *pipe,
1592     struct label *pipelabel)
1593 {
1594 	struct mac_mls *subj, *obj;
1595 
1596 	if (!mac_mls_enabled)
1597 		return (0);
1598 
1599 	subj = SLOT(&cred->cr_label);
1600 	obj = SLOT((pipelabel));
1601 
1602 	if (!mac_mls_dominate_single(obj, subj))
1603 		return (EACCES);
1604 
1605 	return (0);
1606 }
1607 
1608 static int
1609 mac_mls_check_proc_debug(struct ucred *cred, struct proc *proc)
1610 {
1611 	struct mac_mls *subj, *obj;
1612 
1613 	if (!mac_mls_enabled)
1614 		return (0);
1615 
1616 	subj = SLOT(&cred->cr_label);
1617 	obj = SLOT(&proc->p_ucred->cr_label);
1618 
1619 	/* XXX: range checks */
1620 	if (!mac_mls_dominate_single(subj, obj))
1621 		return (ESRCH);
1622 	if (!mac_mls_dominate_single(obj, subj))
1623 		return (EACCES);
1624 
1625 	return (0);
1626 }
1627 
1628 static int
1629 mac_mls_check_proc_sched(struct ucred *cred, struct proc *proc)
1630 {
1631 	struct mac_mls *subj, *obj;
1632 
1633 	if (!mac_mls_enabled)
1634 		return (0);
1635 
1636 	subj = SLOT(&cred->cr_label);
1637 	obj = SLOT(&proc->p_ucred->cr_label);
1638 
1639 	/* XXX: range checks */
1640 	if (!mac_mls_dominate_single(subj, obj))
1641 		return (ESRCH);
1642 	if (!mac_mls_dominate_single(obj, subj))
1643 		return (EACCES);
1644 
1645 	return (0);
1646 }
1647 
1648 static int
1649 mac_mls_check_proc_signal(struct ucred *cred, struct proc *proc, int signum)
1650 {
1651 	struct mac_mls *subj, *obj;
1652 
1653 	if (!mac_mls_enabled)
1654 		return (0);
1655 
1656 	subj = SLOT(&cred->cr_label);
1657 	obj = SLOT(&proc->p_ucred->cr_label);
1658 
1659 	/* XXX: range checks */
1660 	if (!mac_mls_dominate_single(subj, obj))
1661 		return (ESRCH);
1662 	if (!mac_mls_dominate_single(obj, subj))
1663 		return (EACCES);
1664 
1665 	return (0);
1666 }
1667 
1668 static int
1669 mac_mls_check_socket_deliver(struct socket *so, struct label *socketlabel,
1670     struct mbuf *m, struct label *mbuflabel)
1671 {
1672 	struct mac_mls *p, *s;
1673 
1674 	if (!mac_mls_enabled)
1675 		return (0);
1676 
1677 	p = SLOT(mbuflabel);
1678 	s = SLOT(socketlabel);
1679 
1680 	return (mac_mls_equal_single(p, s) ? 0 : EACCES);
1681 }
1682 
1683 static int
1684 mac_mls_check_socket_relabel(struct ucred *cred, struct socket *socket,
1685     struct label *socketlabel, struct label *newlabel)
1686 {
1687 	struct mac_mls *subj, *obj, *new;
1688 	int error;
1689 
1690 	new = SLOT(newlabel);
1691 	subj = SLOT(&cred->cr_label);
1692 	obj = SLOT(socketlabel);
1693 
1694 	/*
1695 	 * If there is an MLS label update for the socket, it may be
1696 	 * an update of single.
1697 	 */
1698 	error = mls_atmostflags(new, MAC_MLS_FLAG_SINGLE);
1699 	if (error)
1700 		return (error);
1701 
1702 	/*
1703 	 * To relabel a socket, the old socket single must be in the subject
1704 	 * range.
1705 	 */
1706 	if (!mac_mls_single_in_range(obj, subj))
1707 		return (EPERM);
1708 
1709 	/*
1710 	 * If the MLS label is to be changed, authorize as appropriate.
1711 	 */
1712 	if (new->mm_flags & MAC_MLS_FLAG_SINGLE) {
1713 		/*
1714 		 * To relabel a socket, the new socket single must be in
1715 		 * the subject range.
1716 		 */
1717 		if (!mac_mls_single_in_range(new, subj))
1718 			return (EPERM);
1719 
1720 		/*
1721 		 * To change the MLS label on the socket to contain EQUAL,
1722 		 * the subject must have appropriate privilege.
1723 		 */
1724 		if (mac_mls_contains_equal(new)) {
1725 			error = mac_mls_subject_equal_ok(subj);
1726 			if (error)
1727 				return (error);
1728 		}
1729 	}
1730 
1731 	return (0);
1732 }
1733 
1734 static int
1735 mac_mls_check_socket_visible(struct ucred *cred, struct socket *socket,
1736     struct label *socketlabel)
1737 {
1738 	struct mac_mls *subj, *obj;
1739 
1740 	if (!mac_mls_enabled)
1741 		return (0);
1742 
1743 	subj = SLOT(&cred->cr_label);
1744 	obj = SLOT(socketlabel);
1745 
1746 	if (!mac_mls_dominate_single(subj, obj))
1747 		return (ENOENT);
1748 
1749 	return (0);
1750 }
1751 
1752 static int
1753 mac_mls_check_system_swapon(struct ucred *cred, struct vnode *vp,
1754     struct label *label)
1755 {
1756 	struct mac_mls *subj, *obj;
1757 
1758 	if (!mac_mls_enabled)
1759 		return (0);
1760 
1761 	subj = SLOT(&cred->cr_label);
1762 	obj = SLOT(label);
1763 
1764 	if (!mac_mls_dominate_single(obj, subj) ||
1765 	    !mac_mls_dominate_single(subj, obj))
1766 		return (EACCES);
1767 
1768 	return (0);
1769 }
1770 
1771 static int
1772 mac_mls_check_vnode_chdir(struct ucred *cred, struct vnode *dvp,
1773     struct label *dlabel)
1774 {
1775 	struct mac_mls *subj, *obj;
1776 
1777 	if (!mac_mls_enabled)
1778 		return (0);
1779 
1780 	subj = SLOT(&cred->cr_label);
1781 	obj = SLOT(dlabel);
1782 
1783 	if (!mac_mls_dominate_single(subj, obj))
1784 		return (EACCES);
1785 
1786 	return (0);
1787 }
1788 
1789 static int
1790 mac_mls_check_vnode_chroot(struct ucred *cred, struct vnode *dvp,
1791     struct label *dlabel)
1792 {
1793 	struct mac_mls *subj, *obj;
1794 
1795 	if (!mac_mls_enabled)
1796 		return (0);
1797 
1798 	subj = SLOT(&cred->cr_label);
1799 	obj = SLOT(dlabel);
1800 
1801 	if (!mac_mls_dominate_single(subj, obj))
1802 		return (EACCES);
1803 
1804 	return (0);
1805 }
1806 
1807 static int
1808 mac_mls_check_vnode_create(struct ucred *cred, struct vnode *dvp,
1809     struct label *dlabel, struct componentname *cnp, struct vattr *vap)
1810 {
1811 	struct mac_mls *subj, *obj;
1812 
1813 	if (!mac_mls_enabled)
1814 		return (0);
1815 
1816 	subj = SLOT(&cred->cr_label);
1817 	obj = SLOT(dlabel);
1818 
1819 	if (!mac_mls_dominate_single(obj, subj))
1820 		return (EACCES);
1821 
1822 	return (0);
1823 }
1824 
1825 static int
1826 mac_mls_check_vnode_delete(struct ucred *cred, struct vnode *dvp,
1827     struct label *dlabel, struct vnode *vp, struct label *label,
1828     struct componentname *cnp)
1829 {
1830 	struct mac_mls *subj, *obj;
1831 
1832 	if (!mac_mls_enabled)
1833 		return (0);
1834 
1835 	subj = SLOT(&cred->cr_label);
1836 	obj = SLOT(dlabel);
1837 
1838 	if (!mac_mls_dominate_single(obj, subj))
1839 		return (EACCES);
1840 
1841 	obj = SLOT(label);
1842 
1843 	if (!mac_mls_dominate_single(obj, subj))
1844 		return (EACCES);
1845 
1846 	return (0);
1847 }
1848 
1849 static int
1850 mac_mls_check_vnode_deleteacl(struct ucred *cred, struct vnode *vp,
1851     struct label *label, acl_type_t type)
1852 {
1853 	struct mac_mls *subj, *obj;
1854 
1855 	if (!mac_mls_enabled)
1856 		return (0);
1857 
1858 	subj = SLOT(&cred->cr_label);
1859 	obj = SLOT(label);
1860 
1861 	if (!mac_mls_dominate_single(obj, subj))
1862 		return (EACCES);
1863 
1864 	return (0);
1865 }
1866 
1867 static int
1868 mac_mls_check_vnode_exec(struct ucred *cred, struct vnode *vp,
1869     struct label *label, struct image_params *imgp,
1870     struct label *execlabel)
1871 {
1872 	struct mac_mls *subj, *obj, *exec;
1873 	int error;
1874 
1875 	if (execlabel != NULL) {
1876 		/*
1877 		 * We currently don't permit labels to be changed at
1878 		 * exec-time as part of MLS, so disallow non-NULL
1879 		 * MLS label elements in the execlabel.
1880 		 */
1881 		exec = SLOT(execlabel);
1882 		error = mls_atmostflags(exec, 0);
1883 		if (error)
1884 			return (error);
1885 	}
1886 
1887 	if (!mac_mls_enabled)
1888 		return (0);
1889 
1890 	subj = SLOT(&cred->cr_label);
1891 	obj = SLOT(label);
1892 
1893 	if (!mac_mls_dominate_single(subj, obj))
1894 		return (EACCES);
1895 
1896 	return (0);
1897 }
1898 
1899 static int
1900 mac_mls_check_vnode_getacl(struct ucred *cred, struct vnode *vp,
1901     struct label *label, acl_type_t type)
1902 {
1903 	struct mac_mls *subj, *obj;
1904 
1905 	if (!mac_mls_enabled)
1906 		return (0);
1907 
1908 	subj = SLOT(&cred->cr_label);
1909 	obj = SLOT(label);
1910 
1911 	if (!mac_mls_dominate_single(subj, obj))
1912 		return (EACCES);
1913 
1914 	return (0);
1915 }
1916 
1917 static int
1918 mac_mls_check_vnode_getextattr(struct ucred *cred, struct vnode *vp,
1919     struct label *label, int attrnamespace, const char *name, struct uio *uio)
1920 {
1921 	struct mac_mls *subj, *obj;
1922 
1923 	if (!mac_mls_enabled)
1924 		return (0);
1925 
1926 	subj = SLOT(&cred->cr_label);
1927 	obj = SLOT(label);
1928 
1929 	if (!mac_mls_dominate_single(subj, obj))
1930 		return (EACCES);
1931 
1932 	return (0);
1933 }
1934 
1935 static int
1936 mac_mls_check_vnode_link(struct ucred *cred, struct vnode *dvp,
1937     struct label *dlabel, struct vnode *vp, struct label *label,
1938     struct componentname *cnp)
1939 {
1940 	struct mac_mls *subj, *obj;
1941 
1942 	if (!mac_mls_enabled)
1943 		return (0);
1944 
1945 	subj = SLOT(&cred->cr_label);
1946 	obj = SLOT(dlabel);
1947 
1948 	if (!mac_mls_dominate_single(obj, subj))
1949 		return (EACCES);
1950 
1951 	obj = SLOT(dlabel);
1952 	if (!mac_mls_dominate_single(obj, subj))
1953 		return (EACCES);
1954 
1955 	return (0);
1956 }
1957 
1958 static int
1959 mac_mls_check_vnode_lookup(struct ucred *cred, struct vnode *dvp,
1960     struct label *dlabel, struct componentname *cnp)
1961 {
1962 	struct mac_mls *subj, *obj;
1963 
1964 	if (!mac_mls_enabled)
1965 		return (0);
1966 
1967 	subj = SLOT(&cred->cr_label);
1968 	obj = SLOT(dlabel);
1969 
1970 	if (!mac_mls_dominate_single(subj, obj))
1971 		return (EACCES);
1972 
1973 	return (0);
1974 }
1975 
1976 static int
1977 mac_mls_check_vnode_mmap(struct ucred *cred, struct vnode *vp,
1978     struct label *label, int prot)
1979 {
1980 	struct mac_mls *subj, *obj;
1981 
1982 	/*
1983 	 * Rely on the use of open()-time protections to handle
1984 	 * non-revocation cases.
1985 	 */
1986 	if (!mac_mls_enabled || !revocation_enabled)
1987 		return (0);
1988 
1989 	subj = SLOT(&cred->cr_label);
1990 	obj = SLOT(label);
1991 
1992 	if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
1993 		if (!mac_mls_dominate_single(subj, obj))
1994 			return (EACCES);
1995 	}
1996 	if (prot & VM_PROT_WRITE) {
1997 		if (!mac_mls_dominate_single(obj, subj))
1998 			return (EACCES);
1999 	}
2000 
2001 	return (0);
2002 }
2003 
2004 static int
2005 mac_mls_check_vnode_open(struct ucred *cred, struct vnode *vp,
2006     struct label *vnodelabel, int acc_mode)
2007 {
2008 	struct mac_mls *subj, *obj;
2009 
2010 	if (!mac_mls_enabled)
2011 		return (0);
2012 
2013 	subj = SLOT(&cred->cr_label);
2014 	obj = SLOT(vnodelabel);
2015 
2016 	/* XXX privilege override for admin? */
2017 	if (acc_mode & (VREAD | VEXEC | VSTAT)) {
2018 		if (!mac_mls_dominate_single(subj, obj))
2019 			return (EACCES);
2020 	}
2021 	if (acc_mode & (VWRITE | VAPPEND | VADMIN)) {
2022 		if (!mac_mls_dominate_single(obj, subj))
2023 			return (EACCES);
2024 	}
2025 
2026 	return (0);
2027 }
2028 
2029 static int
2030 mac_mls_check_vnode_poll(struct ucred *active_cred, struct ucred *file_cred,
2031     struct vnode *vp, struct label *label)
2032 {
2033 	struct mac_mls *subj, *obj;
2034 
2035 	if (!mac_mls_enabled || !revocation_enabled)
2036 		return (0);
2037 
2038 	subj = SLOT(&active_cred->cr_label);
2039 	obj = SLOT(label);
2040 
2041 	if (!mac_mls_dominate_single(subj, obj))
2042 		return (EACCES);
2043 
2044 	return (0);
2045 }
2046 
2047 static int
2048 mac_mls_check_vnode_read(struct ucred *active_cred, struct ucred *file_cred,
2049     struct vnode *vp, struct label *label)
2050 {
2051 	struct mac_mls *subj, *obj;
2052 
2053 	if (!mac_mls_enabled || !revocation_enabled)
2054 		return (0);
2055 
2056 	subj = SLOT(&active_cred->cr_label);
2057 	obj = SLOT(label);
2058 
2059 	if (!mac_mls_dominate_single(subj, obj))
2060 		return (EACCES);
2061 
2062 	return (0);
2063 }
2064 
2065 static int
2066 mac_mls_check_vnode_readdir(struct ucred *cred, struct vnode *dvp,
2067     struct label *dlabel)
2068 {
2069 	struct mac_mls *subj, *obj;
2070 
2071 	if (!mac_mls_enabled)
2072 		return (0);
2073 
2074 	subj = SLOT(&cred->cr_label);
2075 	obj = SLOT(dlabel);
2076 
2077 	if (!mac_mls_dominate_single(subj, obj))
2078 		return (EACCES);
2079 
2080 	return (0);
2081 }
2082 
2083 static int
2084 mac_mls_check_vnode_readlink(struct ucred *cred, struct vnode *vp,
2085     struct label *vnodelabel)
2086 {
2087 	struct mac_mls *subj, *obj;
2088 
2089 	if (!mac_mls_enabled)
2090 		return (0);
2091 
2092 	subj = SLOT(&cred->cr_label);
2093 	obj = SLOT(vnodelabel);
2094 
2095 	if (!mac_mls_dominate_single(subj, obj))
2096 		return (EACCES);
2097 
2098 	return (0);
2099 }
2100 
2101 static int
2102 mac_mls_check_vnode_relabel(struct ucred *cred, struct vnode *vp,
2103     struct label *vnodelabel, struct label *newlabel)
2104 {
2105 	struct mac_mls *old, *new, *subj;
2106 	int error;
2107 
2108 	old = SLOT(vnodelabel);
2109 	new = SLOT(newlabel);
2110 	subj = SLOT(&cred->cr_label);
2111 
2112 	/*
2113 	 * If there is an MLS label update for the vnode, it must be a
2114 	 * single label.
2115 	 */
2116 	error = mls_atmostflags(new, MAC_MLS_FLAG_SINGLE);
2117 	if (error)
2118 		return (error);
2119 
2120 	/*
2121 	 * To perform a relabel of the vnode (MLS label or not), MLS must
2122 	 * authorize the relabel.
2123 	 */
2124 	if (!mac_mls_single_in_range(old, subj))
2125 		return (EPERM);
2126 
2127 	/*
2128 	 * If the MLS label is to be changed, authorize as appropriate.
2129 	 */
2130 	if (new->mm_flags & MAC_MLS_FLAG_SINGLE) {
2131 		/*
2132 		 * To change the MLS label on a vnode, the new vnode label
2133 		 * must be in the subject range.
2134 		 */
2135 		if (!mac_mls_single_in_range(new, subj))
2136 			return (EPERM);
2137 
2138 		/*
2139 		 * To change the MLS label on the vnode to be EQUAL,
2140 		 * the subject must have appropriate privilege.
2141 		 */
2142 		if (mac_mls_contains_equal(new)) {
2143 			error = mac_mls_subject_equal_ok(subj);
2144 			if (error)
2145 				return (error);
2146 		}
2147 	}
2148 
2149 	return (0);
2150 }
2151 
2152 
2153 static int
2154 mac_mls_check_vnode_rename_from(struct ucred *cred, struct vnode *dvp,
2155     struct label *dlabel, struct vnode *vp, struct label *label,
2156     struct componentname *cnp)
2157 {
2158 	struct mac_mls *subj, *obj;
2159 
2160 	if (!mac_mls_enabled)
2161 		return (0);
2162 
2163 	subj = SLOT(&cred->cr_label);
2164 	obj = SLOT(dlabel);
2165 
2166 	if (!mac_mls_dominate_single(obj, subj))
2167 		return (EACCES);
2168 
2169 	obj = SLOT(label);
2170 
2171 	if (!mac_mls_dominate_single(obj, subj))
2172 		return (EACCES);
2173 
2174 	return (0);
2175 }
2176 
2177 static int
2178 mac_mls_check_vnode_rename_to(struct ucred *cred, struct vnode *dvp,
2179     struct label *dlabel, struct vnode *vp, struct label *label, int samedir,
2180     struct componentname *cnp)
2181 {
2182 	struct mac_mls *subj, *obj;
2183 
2184 	if (!mac_mls_enabled)
2185 		return (0);
2186 
2187 	subj = SLOT(&cred->cr_label);
2188 	obj = SLOT(dlabel);
2189 
2190 	if (!mac_mls_dominate_single(obj, subj))
2191 		return (EACCES);
2192 
2193 	if (vp != NULL) {
2194 		obj = SLOT(label);
2195 
2196 		if (!mac_mls_dominate_single(obj, subj))
2197 			return (EACCES);
2198 	}
2199 
2200 	return (0);
2201 }
2202 
2203 static int
2204 mac_mls_check_vnode_revoke(struct ucred *cred, struct vnode *vp,
2205     struct label *label)
2206 {
2207 	struct mac_mls *subj, *obj;
2208 
2209 	if (!mac_mls_enabled)
2210 		return (0);
2211 
2212 	subj = SLOT(&cred->cr_label);
2213 	obj = SLOT(label);
2214 
2215 	if (!mac_mls_dominate_single(obj, subj))
2216 		return (EACCES);
2217 
2218 	return (0);
2219 }
2220 
2221 static int
2222 mac_mls_check_vnode_setacl(struct ucred *cred, struct vnode *vp,
2223     struct label *label, acl_type_t type, struct acl *acl)
2224 {
2225 	struct mac_mls *subj, *obj;
2226 
2227 	if (!mac_mls_enabled)
2228 		return (0);
2229 
2230 	subj = SLOT(&cred->cr_label);
2231 	obj = SLOT(label);
2232 
2233 	if (!mac_mls_dominate_single(obj, subj))
2234 		return (EACCES);
2235 
2236 	return (0);
2237 }
2238 
2239 static int
2240 mac_mls_check_vnode_setextattr(struct ucred *cred, struct vnode *vp,
2241     struct label *vnodelabel, int attrnamespace, const char *name,
2242     struct uio *uio)
2243 {
2244 	struct mac_mls *subj, *obj;
2245 
2246 	if (!mac_mls_enabled)
2247 		return (0);
2248 
2249 	subj = SLOT(&cred->cr_label);
2250 	obj = SLOT(vnodelabel);
2251 
2252 	if (!mac_mls_dominate_single(obj, subj))
2253 		return (EACCES);
2254 
2255 	/* XXX: protect the MAC EA in a special way? */
2256 
2257 	return (0);
2258 }
2259 
2260 static int
2261 mac_mls_check_vnode_setflags(struct ucred *cred, struct vnode *vp,
2262     struct label *vnodelabel, u_long flags)
2263 {
2264 	struct mac_mls *subj, *obj;
2265 
2266 	if (!mac_mls_enabled)
2267 		return (0);
2268 
2269 	subj = SLOT(&cred->cr_label);
2270 	obj = SLOT(vnodelabel);
2271 
2272 	if (!mac_mls_dominate_single(obj, subj))
2273 		return (EACCES);
2274 
2275 	return (0);
2276 }
2277 
2278 static int
2279 mac_mls_check_vnode_setmode(struct ucred *cred, struct vnode *vp,
2280     struct label *vnodelabel, mode_t mode)
2281 {
2282 	struct mac_mls *subj, *obj;
2283 
2284 	if (!mac_mls_enabled)
2285 		return (0);
2286 
2287 	subj = SLOT(&cred->cr_label);
2288 	obj = SLOT(vnodelabel);
2289 
2290 	if (!mac_mls_dominate_single(obj, subj))
2291 		return (EACCES);
2292 
2293 	return (0);
2294 }
2295 
2296 static int
2297 mac_mls_check_vnode_setowner(struct ucred *cred, struct vnode *vp,
2298     struct label *vnodelabel, uid_t uid, gid_t gid)
2299 {
2300 	struct mac_mls *subj, *obj;
2301 
2302 	if (!mac_mls_enabled)
2303 		return (0);
2304 
2305 	subj = SLOT(&cred->cr_label);
2306 	obj = SLOT(vnodelabel);
2307 
2308 	if (!mac_mls_dominate_single(obj, subj))
2309 		return (EACCES);
2310 
2311 	return (0);
2312 }
2313 
2314 static int
2315 mac_mls_check_vnode_setutimes(struct ucred *cred, struct vnode *vp,
2316     struct label *vnodelabel, struct timespec atime, struct timespec mtime)
2317 {
2318 	struct mac_mls *subj, *obj;
2319 
2320 	if (!mac_mls_enabled)
2321 		return (0);
2322 
2323 	subj = SLOT(&cred->cr_label);
2324 	obj = SLOT(vnodelabel);
2325 
2326 	if (!mac_mls_dominate_single(obj, subj))
2327 		return (EACCES);
2328 
2329 	return (0);
2330 }
2331 
2332 static int
2333 mac_mls_check_vnode_stat(struct ucred *active_cred, struct ucred *file_cred,
2334     struct vnode *vp, struct label *vnodelabel)
2335 {
2336 	struct mac_mls *subj, *obj;
2337 
2338 	if (!mac_mls_enabled)
2339 		return (0);
2340 
2341 	subj = SLOT(&active_cred->cr_label);
2342 	obj = SLOT(vnodelabel);
2343 
2344 	if (!mac_mls_dominate_single(subj, obj))
2345 		return (EACCES);
2346 
2347 	return (0);
2348 }
2349 
2350 static int
2351 mac_mls_check_vnode_write(struct ucred *active_cred, struct ucred *file_cred,
2352     struct vnode *vp, struct label *label)
2353 {
2354 	struct mac_mls *subj, *obj;
2355 
2356 	if (!mac_mls_enabled || !revocation_enabled)
2357 		return (0);
2358 
2359 	subj = SLOT(&active_cred->cr_label);
2360 	obj = SLOT(label);
2361 
2362 	if (!mac_mls_dominate_single(obj, subj))
2363 		return (EACCES);
2364 
2365 	return (0);
2366 }
2367 
2368 static struct mac_policy_ops mac_mls_ops =
2369 {
2370 	.mpo_destroy = mac_mls_destroy,
2371 	.mpo_init = mac_mls_init,
2372 	.mpo_init_bpfdesc_label = mac_mls_init_label,
2373 	.mpo_init_cred_label = mac_mls_init_label,
2374 	.mpo_init_devfsdirent_label = mac_mls_init_label,
2375 	.mpo_init_ifnet_label = mac_mls_init_label,
2376 	.mpo_init_ipq_label = mac_mls_init_label_waitcheck,
2377 	.mpo_init_mbuf_label = mac_mls_init_label_waitcheck,
2378 	.mpo_init_mount_label = mac_mls_init_label,
2379 	.mpo_init_mount_fs_label = mac_mls_init_label,
2380 	.mpo_init_pipe_label = mac_mls_init_label,
2381 	.mpo_init_socket_label = mac_mls_init_label_waitcheck,
2382 	.mpo_init_socket_peer_label = mac_mls_init_label_waitcheck,
2383 	.mpo_init_vnode_label = mac_mls_init_label,
2384 	.mpo_destroy_bpfdesc_label = mac_mls_destroy_label,
2385 	.mpo_destroy_cred_label = mac_mls_destroy_label,
2386 	.mpo_destroy_devfsdirent_label = mac_mls_destroy_label,
2387 	.mpo_destroy_ifnet_label = mac_mls_destroy_label,
2388 	.mpo_destroy_ipq_label = mac_mls_destroy_label,
2389 	.mpo_destroy_mbuf_label = mac_mls_destroy_label,
2390 	.mpo_destroy_mount_label = mac_mls_destroy_label,
2391 	.mpo_destroy_mount_fs_label = mac_mls_destroy_label,
2392 	.mpo_destroy_pipe_label = mac_mls_destroy_label,
2393 	.mpo_destroy_socket_label = mac_mls_destroy_label,
2394 	.mpo_destroy_socket_peer_label = mac_mls_destroy_label,
2395 	.mpo_destroy_vnode_label = mac_mls_destroy_label,
2396 	.mpo_copy_mbuf_label = mac_mls_copy_label,
2397 	.mpo_copy_pipe_label = mac_mls_copy_label,
2398 	.mpo_copy_vnode_label = mac_mls_copy_label,
2399 	.mpo_externalize_cred_label = mac_mls_externalize_label,
2400 	.mpo_externalize_ifnet_label = mac_mls_externalize_label,
2401 	.mpo_externalize_pipe_label = mac_mls_externalize_label,
2402 	.mpo_externalize_socket_label = mac_mls_externalize_label,
2403 	.mpo_externalize_socket_peer_label = mac_mls_externalize_label,
2404 	.mpo_externalize_vnode_label = mac_mls_externalize_label,
2405 	.mpo_internalize_cred_label = mac_mls_internalize_label,
2406 	.mpo_internalize_ifnet_label = mac_mls_internalize_label,
2407 	.mpo_internalize_pipe_label = mac_mls_internalize_label,
2408 	.mpo_internalize_socket_label = mac_mls_internalize_label,
2409 	.mpo_internalize_vnode_label = mac_mls_internalize_label,
2410 	.mpo_create_devfs_device = mac_mls_create_devfs_device,
2411 	.mpo_create_devfs_directory = mac_mls_create_devfs_directory,
2412 	.mpo_create_devfs_symlink = mac_mls_create_devfs_symlink,
2413 	.mpo_create_mount = mac_mls_create_mount,
2414 	.mpo_create_root_mount = mac_mls_create_root_mount,
2415 	.mpo_relabel_vnode = mac_mls_relabel_vnode,
2416 	.mpo_update_devfsdirent = mac_mls_update_devfsdirent,
2417 	.mpo_associate_vnode_devfs = mac_mls_associate_vnode_devfs,
2418 	.mpo_associate_vnode_extattr = mac_mls_associate_vnode_extattr,
2419 	.mpo_associate_vnode_singlelabel = mac_mls_associate_vnode_singlelabel,
2420 	.mpo_create_vnode_extattr = mac_mls_create_vnode_extattr,
2421 	.mpo_setlabel_vnode_extattr = mac_mls_setlabel_vnode_extattr,
2422 	.mpo_create_mbuf_from_socket = mac_mls_create_mbuf_from_socket,
2423 	.mpo_create_pipe = mac_mls_create_pipe,
2424 	.mpo_create_socket = mac_mls_create_socket,
2425 	.mpo_create_socket_from_socket = mac_mls_create_socket_from_socket,
2426 	.mpo_relabel_pipe = mac_mls_relabel_pipe,
2427 	.mpo_relabel_socket = mac_mls_relabel_socket,
2428 	.mpo_set_socket_peer_from_mbuf = mac_mls_set_socket_peer_from_mbuf,
2429 	.mpo_set_socket_peer_from_socket = mac_mls_set_socket_peer_from_socket,
2430 	.mpo_create_bpfdesc = mac_mls_create_bpfdesc,
2431 	.mpo_create_datagram_from_ipq = mac_mls_create_datagram_from_ipq,
2432 	.mpo_create_fragment = mac_mls_create_fragment,
2433 	.mpo_create_ifnet = mac_mls_create_ifnet,
2434 	.mpo_create_ipq = mac_mls_create_ipq,
2435 	.mpo_create_mbuf_from_mbuf = mac_mls_create_mbuf_from_mbuf,
2436 	.mpo_create_mbuf_linklayer = mac_mls_create_mbuf_linklayer,
2437 	.mpo_create_mbuf_from_bpfdesc = mac_mls_create_mbuf_from_bpfdesc,
2438 	.mpo_create_mbuf_from_ifnet = mac_mls_create_mbuf_from_ifnet,
2439 	.mpo_create_mbuf_multicast_encap = mac_mls_create_mbuf_multicast_encap,
2440 	.mpo_create_mbuf_netlayer = mac_mls_create_mbuf_netlayer,
2441 	.mpo_fragment_match = mac_mls_fragment_match,
2442 	.mpo_relabel_ifnet = mac_mls_relabel_ifnet,
2443 	.mpo_update_ipq = mac_mls_update_ipq,
2444 	.mpo_create_cred = mac_mls_create_cred,
2445 	.mpo_create_proc0 = mac_mls_create_proc0,
2446 	.mpo_create_proc1 = mac_mls_create_proc1,
2447 	.mpo_relabel_cred = mac_mls_relabel_cred,
2448 	.mpo_check_bpfdesc_receive = mac_mls_check_bpfdesc_receive,
2449 	.mpo_check_cred_relabel = mac_mls_check_cred_relabel,
2450 	.mpo_check_cred_visible = mac_mls_check_cred_visible,
2451 	.mpo_check_ifnet_relabel = mac_mls_check_ifnet_relabel,
2452 	.mpo_check_ifnet_transmit = mac_mls_check_ifnet_transmit,
2453 	.mpo_check_mount_stat = mac_mls_check_mount_stat,
2454 	.mpo_check_pipe_ioctl = mac_mls_check_pipe_ioctl,
2455 	.mpo_check_pipe_poll = mac_mls_check_pipe_poll,
2456 	.mpo_check_pipe_read = mac_mls_check_pipe_read,
2457 	.mpo_check_pipe_relabel = mac_mls_check_pipe_relabel,
2458 	.mpo_check_pipe_stat = mac_mls_check_pipe_stat,
2459 	.mpo_check_pipe_write = mac_mls_check_pipe_write,
2460 	.mpo_check_proc_debug = mac_mls_check_proc_debug,
2461 	.mpo_check_proc_sched = mac_mls_check_proc_sched,
2462 	.mpo_check_proc_signal = mac_mls_check_proc_signal,
2463 	.mpo_check_socket_deliver = mac_mls_check_socket_deliver,
2464 	.mpo_check_socket_relabel = mac_mls_check_socket_relabel,
2465 	.mpo_check_socket_visible = mac_mls_check_socket_visible,
2466 	.mpo_check_system_swapon = mac_mls_check_system_swapon,
2467 	.mpo_check_vnode_access = mac_mls_check_vnode_open,
2468 	.mpo_check_vnode_chdir = mac_mls_check_vnode_chdir,
2469 	.mpo_check_vnode_chroot = mac_mls_check_vnode_chroot,
2470 	.mpo_check_vnode_create = mac_mls_check_vnode_create,
2471 	.mpo_check_vnode_delete = mac_mls_check_vnode_delete,
2472 	.mpo_check_vnode_deleteacl = mac_mls_check_vnode_deleteacl,
2473 	.mpo_check_vnode_exec = mac_mls_check_vnode_exec,
2474 	.mpo_check_vnode_getacl = mac_mls_check_vnode_getacl,
2475 	.mpo_check_vnode_getextattr = mac_mls_check_vnode_getextattr,
2476 	.mpo_check_vnode_link = mac_mls_check_vnode_link,
2477 	.mpo_check_vnode_lookup = mac_mls_check_vnode_lookup,
2478 	.mpo_check_vnode_mmap = mac_mls_check_vnode_mmap,
2479 	.mpo_check_vnode_mprotect = mac_mls_check_vnode_mmap,
2480 	.mpo_check_vnode_open = mac_mls_check_vnode_open,
2481 	.mpo_check_vnode_poll = mac_mls_check_vnode_poll,
2482 	.mpo_check_vnode_read = mac_mls_check_vnode_read,
2483 	.mpo_check_vnode_readdir = mac_mls_check_vnode_readdir,
2484 	.mpo_check_vnode_readlink = mac_mls_check_vnode_readlink,
2485 	.mpo_check_vnode_relabel = mac_mls_check_vnode_relabel,
2486 	.mpo_check_vnode_rename_from = mac_mls_check_vnode_rename_from,
2487 	.mpo_check_vnode_rename_to = mac_mls_check_vnode_rename_to,
2488 	.mpo_check_vnode_revoke = mac_mls_check_vnode_revoke,
2489 	.mpo_check_vnode_setacl = mac_mls_check_vnode_setacl,
2490 	.mpo_check_vnode_setextattr = mac_mls_check_vnode_setextattr,
2491 	.mpo_check_vnode_setflags = mac_mls_check_vnode_setflags,
2492 	.mpo_check_vnode_setmode = mac_mls_check_vnode_setmode,
2493 	.mpo_check_vnode_setowner = mac_mls_check_vnode_setowner,
2494 	.mpo_check_vnode_setutimes = mac_mls_check_vnode_setutimes,
2495 	.mpo_check_vnode_stat = mac_mls_check_vnode_stat,
2496 	.mpo_check_vnode_write = mac_mls_check_vnode_write,
2497 };
2498 
2499 MAC_POLICY_SET(&mac_mls_ops, mac_mls, "TrustedBSD MAC/MLS",
2500     MPC_LOADTIME_FLAG_NOTLATE | MPC_LOADTIME_FLAG_LABELMBUFS, &mac_mls_slot);
2501