xref: /linux/security/selinux/ss/services.c (revision 339949be25863ac15e24659c2ab4b01185e1234a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Implementation of the security services.
4  *
5  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
6  *	     James Morris <jmorris@redhat.com>
7  *
8  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
9  *
10  *	Support for enhanced MLS infrastructure.
11  *	Support for context based audit filters.
12  *
13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
14  *
15  *	Added conditional policy language extensions
16  *
17  * Updated: Hewlett-Packard <paul@paul-moore.com>
18  *
19  *      Added support for NetLabel
20  *      Added support for the policy capability bitmap
21  *
22  * Updated: Chad Sellers <csellers@tresys.com>
23  *
24  *  Added validation of kernel classes and permissions
25  *
26  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
27  *
28  *  Added support for bounds domain and audit messaged on masked permissions
29  *
30  * Updated: Guido Trentalancia <guido@trentalancia.com>
31  *
32  *  Added support for runtime switching of the policy type
33  *
34  * Copyright (C) 2008, 2009 NEC Corporation
35  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
36  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
37  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
38  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
39  */
40 #include <linux/kernel.h>
41 #include <linux/slab.h>
42 #include <linux/string.h>
43 #include <linux/spinlock.h>
44 #include <linux/rcupdate.h>
45 #include <linux/errno.h>
46 #include <linux/in.h>
47 #include <linux/sched.h>
48 #include <linux/audit.h>
49 #include <linux/vmalloc.h>
50 #include <net/netlabel.h>
51 
52 #include "flask.h"
53 #include "avc.h"
54 #include "avc_ss.h"
55 #include "security.h"
56 #include "context.h"
57 #include "policydb.h"
58 #include "sidtab.h"
59 #include "services.h"
60 #include "conditional.h"
61 #include "mls.h"
62 #include "objsec.h"
63 #include "netlabel.h"
64 #include "xfrm.h"
65 #include "ebitmap.h"
66 #include "audit.h"
67 #include "policycap_names.h"
68 
69 static struct selinux_ss selinux_ss;
70 
71 void selinux_ss_init(struct selinux_ss **ss)
72 {
73 	rwlock_init(&selinux_ss.policy_rwlock);
74 	*ss = &selinux_ss;
75 }
76 
77 /* Forward declaration. */
78 static int context_struct_to_string(struct policydb *policydb,
79 				    struct context *context,
80 				    char **scontext,
81 				    u32 *scontext_len);
82 
83 static int sidtab_entry_to_string(struct policydb *policydb,
84 				  struct sidtab *sidtab,
85 				  struct sidtab_entry *entry,
86 				  char **scontext,
87 				  u32 *scontext_len);
88 
89 static void context_struct_compute_av(struct policydb *policydb,
90 				      struct context *scontext,
91 				      struct context *tcontext,
92 				      u16 tclass,
93 				      struct av_decision *avd,
94 				      struct extended_perms *xperms);
95 
96 static int selinux_set_mapping(struct policydb *pol,
97 			       struct security_class_mapping *map,
98 			       struct selinux_map *out_map)
99 {
100 	u16 i, j;
101 	unsigned k;
102 	bool print_unknown_handle = false;
103 
104 	/* Find number of classes in the input mapping */
105 	if (!map)
106 		return -EINVAL;
107 	i = 0;
108 	while (map[i].name)
109 		i++;
110 
111 	/* Allocate space for the class records, plus one for class zero */
112 	out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
113 	if (!out_map->mapping)
114 		return -ENOMEM;
115 
116 	/* Store the raw class and permission values */
117 	j = 0;
118 	while (map[j].name) {
119 		struct security_class_mapping *p_in = map + (j++);
120 		struct selinux_mapping *p_out = out_map->mapping + j;
121 
122 		/* An empty class string skips ahead */
123 		if (!strcmp(p_in->name, "")) {
124 			p_out->num_perms = 0;
125 			continue;
126 		}
127 
128 		p_out->value = string_to_security_class(pol, p_in->name);
129 		if (!p_out->value) {
130 			pr_info("SELinux:  Class %s not defined in policy.\n",
131 			       p_in->name);
132 			if (pol->reject_unknown)
133 				goto err;
134 			p_out->num_perms = 0;
135 			print_unknown_handle = true;
136 			continue;
137 		}
138 
139 		k = 0;
140 		while (p_in->perms[k]) {
141 			/* An empty permission string skips ahead */
142 			if (!*p_in->perms[k]) {
143 				k++;
144 				continue;
145 			}
146 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
147 							    p_in->perms[k]);
148 			if (!p_out->perms[k]) {
149 				pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
150 				       p_in->perms[k], p_in->name);
151 				if (pol->reject_unknown)
152 					goto err;
153 				print_unknown_handle = true;
154 			}
155 
156 			k++;
157 		}
158 		p_out->num_perms = k;
159 	}
160 
161 	if (print_unknown_handle)
162 		pr_info("SELinux: the above unknown classes and permissions will be %s\n",
163 		       pol->allow_unknown ? "allowed" : "denied");
164 
165 	out_map->size = i;
166 	return 0;
167 err:
168 	kfree(out_map->mapping);
169 	out_map->mapping = NULL;
170 	return -EINVAL;
171 }
172 
173 /*
174  * Get real, policy values from mapped values
175  */
176 
177 static u16 unmap_class(struct selinux_map *map, u16 tclass)
178 {
179 	if (tclass < map->size)
180 		return map->mapping[tclass].value;
181 
182 	return tclass;
183 }
184 
185 /*
186  * Get kernel value for class from its policy value
187  */
188 static u16 map_class(struct selinux_map *map, u16 pol_value)
189 {
190 	u16 i;
191 
192 	for (i = 1; i < map->size; i++) {
193 		if (map->mapping[i].value == pol_value)
194 			return i;
195 	}
196 
197 	return SECCLASS_NULL;
198 }
199 
200 static void map_decision(struct selinux_map *map,
201 			 u16 tclass, struct av_decision *avd,
202 			 int allow_unknown)
203 {
204 	if (tclass < map->size) {
205 		struct selinux_mapping *mapping = &map->mapping[tclass];
206 		unsigned int i, n = mapping->num_perms;
207 		u32 result;
208 
209 		for (i = 0, result = 0; i < n; i++) {
210 			if (avd->allowed & mapping->perms[i])
211 				result |= 1<<i;
212 			if (allow_unknown && !mapping->perms[i])
213 				result |= 1<<i;
214 		}
215 		avd->allowed = result;
216 
217 		for (i = 0, result = 0; i < n; i++)
218 			if (avd->auditallow & mapping->perms[i])
219 				result |= 1<<i;
220 		avd->auditallow = result;
221 
222 		for (i = 0, result = 0; i < n; i++) {
223 			if (avd->auditdeny & mapping->perms[i])
224 				result |= 1<<i;
225 			if (!allow_unknown && !mapping->perms[i])
226 				result |= 1<<i;
227 		}
228 		/*
229 		 * In case the kernel has a bug and requests a permission
230 		 * between num_perms and the maximum permission number, we
231 		 * should audit that denial
232 		 */
233 		for (; i < (sizeof(u32)*8); i++)
234 			result |= 1<<i;
235 		avd->auditdeny = result;
236 	}
237 }
238 
239 int security_mls_enabled(struct selinux_state *state)
240 {
241 	struct policydb *p = &state->ss->policydb;
242 
243 	return p->mls_enabled;
244 }
245 
246 /*
247  * Return the boolean value of a constraint expression
248  * when it is applied to the specified source and target
249  * security contexts.
250  *
251  * xcontext is a special beast...  It is used by the validatetrans rules
252  * only.  For these rules, scontext is the context before the transition,
253  * tcontext is the context after the transition, and xcontext is the context
254  * of the process performing the transition.  All other callers of
255  * constraint_expr_eval should pass in NULL for xcontext.
256  */
257 static int constraint_expr_eval(struct policydb *policydb,
258 				struct context *scontext,
259 				struct context *tcontext,
260 				struct context *xcontext,
261 				struct constraint_expr *cexpr)
262 {
263 	u32 val1, val2;
264 	struct context *c;
265 	struct role_datum *r1, *r2;
266 	struct mls_level *l1, *l2;
267 	struct constraint_expr *e;
268 	int s[CEXPR_MAXDEPTH];
269 	int sp = -1;
270 
271 	for (e = cexpr; e; e = e->next) {
272 		switch (e->expr_type) {
273 		case CEXPR_NOT:
274 			BUG_ON(sp < 0);
275 			s[sp] = !s[sp];
276 			break;
277 		case CEXPR_AND:
278 			BUG_ON(sp < 1);
279 			sp--;
280 			s[sp] &= s[sp + 1];
281 			break;
282 		case CEXPR_OR:
283 			BUG_ON(sp < 1);
284 			sp--;
285 			s[sp] |= s[sp + 1];
286 			break;
287 		case CEXPR_ATTR:
288 			if (sp == (CEXPR_MAXDEPTH - 1))
289 				return 0;
290 			switch (e->attr) {
291 			case CEXPR_USER:
292 				val1 = scontext->user;
293 				val2 = tcontext->user;
294 				break;
295 			case CEXPR_TYPE:
296 				val1 = scontext->type;
297 				val2 = tcontext->type;
298 				break;
299 			case CEXPR_ROLE:
300 				val1 = scontext->role;
301 				val2 = tcontext->role;
302 				r1 = policydb->role_val_to_struct[val1 - 1];
303 				r2 = policydb->role_val_to_struct[val2 - 1];
304 				switch (e->op) {
305 				case CEXPR_DOM:
306 					s[++sp] = ebitmap_get_bit(&r1->dominates,
307 								  val2 - 1);
308 					continue;
309 				case CEXPR_DOMBY:
310 					s[++sp] = ebitmap_get_bit(&r2->dominates,
311 								  val1 - 1);
312 					continue;
313 				case CEXPR_INCOMP:
314 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
315 								    val2 - 1) &&
316 						   !ebitmap_get_bit(&r2->dominates,
317 								    val1 - 1));
318 					continue;
319 				default:
320 					break;
321 				}
322 				break;
323 			case CEXPR_L1L2:
324 				l1 = &(scontext->range.level[0]);
325 				l2 = &(tcontext->range.level[0]);
326 				goto mls_ops;
327 			case CEXPR_L1H2:
328 				l1 = &(scontext->range.level[0]);
329 				l2 = &(tcontext->range.level[1]);
330 				goto mls_ops;
331 			case CEXPR_H1L2:
332 				l1 = &(scontext->range.level[1]);
333 				l2 = &(tcontext->range.level[0]);
334 				goto mls_ops;
335 			case CEXPR_H1H2:
336 				l1 = &(scontext->range.level[1]);
337 				l2 = &(tcontext->range.level[1]);
338 				goto mls_ops;
339 			case CEXPR_L1H1:
340 				l1 = &(scontext->range.level[0]);
341 				l2 = &(scontext->range.level[1]);
342 				goto mls_ops;
343 			case CEXPR_L2H2:
344 				l1 = &(tcontext->range.level[0]);
345 				l2 = &(tcontext->range.level[1]);
346 				goto mls_ops;
347 mls_ops:
348 			switch (e->op) {
349 			case CEXPR_EQ:
350 				s[++sp] = mls_level_eq(l1, l2);
351 				continue;
352 			case CEXPR_NEQ:
353 				s[++sp] = !mls_level_eq(l1, l2);
354 				continue;
355 			case CEXPR_DOM:
356 				s[++sp] = mls_level_dom(l1, l2);
357 				continue;
358 			case CEXPR_DOMBY:
359 				s[++sp] = mls_level_dom(l2, l1);
360 				continue;
361 			case CEXPR_INCOMP:
362 				s[++sp] = mls_level_incomp(l2, l1);
363 				continue;
364 			default:
365 				BUG();
366 				return 0;
367 			}
368 			break;
369 			default:
370 				BUG();
371 				return 0;
372 			}
373 
374 			switch (e->op) {
375 			case CEXPR_EQ:
376 				s[++sp] = (val1 == val2);
377 				break;
378 			case CEXPR_NEQ:
379 				s[++sp] = (val1 != val2);
380 				break;
381 			default:
382 				BUG();
383 				return 0;
384 			}
385 			break;
386 		case CEXPR_NAMES:
387 			if (sp == (CEXPR_MAXDEPTH-1))
388 				return 0;
389 			c = scontext;
390 			if (e->attr & CEXPR_TARGET)
391 				c = tcontext;
392 			else if (e->attr & CEXPR_XTARGET) {
393 				c = xcontext;
394 				if (!c) {
395 					BUG();
396 					return 0;
397 				}
398 			}
399 			if (e->attr & CEXPR_USER)
400 				val1 = c->user;
401 			else if (e->attr & CEXPR_ROLE)
402 				val1 = c->role;
403 			else if (e->attr & CEXPR_TYPE)
404 				val1 = c->type;
405 			else {
406 				BUG();
407 				return 0;
408 			}
409 
410 			switch (e->op) {
411 			case CEXPR_EQ:
412 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
413 				break;
414 			case CEXPR_NEQ:
415 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
416 				break;
417 			default:
418 				BUG();
419 				return 0;
420 			}
421 			break;
422 		default:
423 			BUG();
424 			return 0;
425 		}
426 	}
427 
428 	BUG_ON(sp != 0);
429 	return s[0];
430 }
431 
432 /*
433  * security_dump_masked_av - dumps masked permissions during
434  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
435  */
436 static int dump_masked_av_helper(void *k, void *d, void *args)
437 {
438 	struct perm_datum *pdatum = d;
439 	char **permission_names = args;
440 
441 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
442 
443 	permission_names[pdatum->value - 1] = (char *)k;
444 
445 	return 0;
446 }
447 
448 static void security_dump_masked_av(struct policydb *policydb,
449 				    struct context *scontext,
450 				    struct context *tcontext,
451 				    u16 tclass,
452 				    u32 permissions,
453 				    const char *reason)
454 {
455 	struct common_datum *common_dat;
456 	struct class_datum *tclass_dat;
457 	struct audit_buffer *ab;
458 	char *tclass_name;
459 	char *scontext_name = NULL;
460 	char *tcontext_name = NULL;
461 	char *permission_names[32];
462 	int index;
463 	u32 length;
464 	bool need_comma = false;
465 
466 	if (!permissions)
467 		return;
468 
469 	tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
470 	tclass_dat = policydb->class_val_to_struct[tclass - 1];
471 	common_dat = tclass_dat->comdatum;
472 
473 	/* init permission_names */
474 	if (common_dat &&
475 	    hashtab_map(&common_dat->permissions.table,
476 			dump_masked_av_helper, permission_names) < 0)
477 		goto out;
478 
479 	if (hashtab_map(&tclass_dat->permissions.table,
480 			dump_masked_av_helper, permission_names) < 0)
481 		goto out;
482 
483 	/* get scontext/tcontext in text form */
484 	if (context_struct_to_string(policydb, scontext,
485 				     &scontext_name, &length) < 0)
486 		goto out;
487 
488 	if (context_struct_to_string(policydb, tcontext,
489 				     &tcontext_name, &length) < 0)
490 		goto out;
491 
492 	/* audit a message */
493 	ab = audit_log_start(audit_context(),
494 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
495 	if (!ab)
496 		goto out;
497 
498 	audit_log_format(ab, "op=security_compute_av reason=%s "
499 			 "scontext=%s tcontext=%s tclass=%s perms=",
500 			 reason, scontext_name, tcontext_name, tclass_name);
501 
502 	for (index = 0; index < 32; index++) {
503 		u32 mask = (1 << index);
504 
505 		if ((mask & permissions) == 0)
506 			continue;
507 
508 		audit_log_format(ab, "%s%s",
509 				 need_comma ? "," : "",
510 				 permission_names[index]
511 				 ? permission_names[index] : "????");
512 		need_comma = true;
513 	}
514 	audit_log_end(ab);
515 out:
516 	/* release scontext/tcontext */
517 	kfree(tcontext_name);
518 	kfree(scontext_name);
519 
520 	return;
521 }
522 
523 /*
524  * security_boundary_permission - drops violated permissions
525  * on boundary constraint.
526  */
527 static void type_attribute_bounds_av(struct policydb *policydb,
528 				     struct context *scontext,
529 				     struct context *tcontext,
530 				     u16 tclass,
531 				     struct av_decision *avd)
532 {
533 	struct context lo_scontext;
534 	struct context lo_tcontext, *tcontextp = tcontext;
535 	struct av_decision lo_avd;
536 	struct type_datum *source;
537 	struct type_datum *target;
538 	u32 masked = 0;
539 
540 	source = policydb->type_val_to_struct[scontext->type - 1];
541 	BUG_ON(!source);
542 
543 	if (!source->bounds)
544 		return;
545 
546 	target = policydb->type_val_to_struct[tcontext->type - 1];
547 	BUG_ON(!target);
548 
549 	memset(&lo_avd, 0, sizeof(lo_avd));
550 
551 	memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
552 	lo_scontext.type = source->bounds;
553 
554 	if (target->bounds) {
555 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
556 		lo_tcontext.type = target->bounds;
557 		tcontextp = &lo_tcontext;
558 	}
559 
560 	context_struct_compute_av(policydb, &lo_scontext,
561 				  tcontextp,
562 				  tclass,
563 				  &lo_avd,
564 				  NULL);
565 
566 	masked = ~lo_avd.allowed & avd->allowed;
567 
568 	if (likely(!masked))
569 		return;		/* no masked permission */
570 
571 	/* mask violated permissions */
572 	avd->allowed &= ~masked;
573 
574 	/* audit masked permissions */
575 	security_dump_masked_av(policydb, scontext, tcontext,
576 				tclass, masked, "bounds");
577 }
578 
579 /*
580  * flag which drivers have permissions
581  * only looking for ioctl based extended permssions
582  */
583 void services_compute_xperms_drivers(
584 		struct extended_perms *xperms,
585 		struct avtab_node *node)
586 {
587 	unsigned int i;
588 
589 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
590 		/* if one or more driver has all permissions allowed */
591 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
592 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
593 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
594 		/* if allowing permissions within a driver */
595 		security_xperm_set(xperms->drivers.p,
596 					node->datum.u.xperms->driver);
597 	}
598 
599 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
600 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
601 		xperms->len = 1;
602 }
603 
604 /*
605  * Compute access vectors and extended permissions based on a context
606  * structure pair for the permissions in a particular class.
607  */
608 static void context_struct_compute_av(struct policydb *policydb,
609 				      struct context *scontext,
610 				      struct context *tcontext,
611 				      u16 tclass,
612 				      struct av_decision *avd,
613 				      struct extended_perms *xperms)
614 {
615 	struct constraint_node *constraint;
616 	struct role_allow *ra;
617 	struct avtab_key avkey;
618 	struct avtab_node *node;
619 	struct class_datum *tclass_datum;
620 	struct ebitmap *sattr, *tattr;
621 	struct ebitmap_node *snode, *tnode;
622 	unsigned int i, j;
623 
624 	avd->allowed = 0;
625 	avd->auditallow = 0;
626 	avd->auditdeny = 0xffffffff;
627 	if (xperms) {
628 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
629 		xperms->len = 0;
630 	}
631 
632 	if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
633 		if (printk_ratelimit())
634 			pr_warn("SELinux:  Invalid class %hu\n", tclass);
635 		return;
636 	}
637 
638 	tclass_datum = policydb->class_val_to_struct[tclass - 1];
639 
640 	/*
641 	 * If a specific type enforcement rule was defined for
642 	 * this permission check, then use it.
643 	 */
644 	avkey.target_class = tclass;
645 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
646 	sattr = &policydb->type_attr_map_array[scontext->type - 1];
647 	tattr = &policydb->type_attr_map_array[tcontext->type - 1];
648 	ebitmap_for_each_positive_bit(sattr, snode, i) {
649 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
650 			avkey.source_type = i + 1;
651 			avkey.target_type = j + 1;
652 			for (node = avtab_search_node(&policydb->te_avtab,
653 						      &avkey);
654 			     node;
655 			     node = avtab_search_node_next(node, avkey.specified)) {
656 				if (node->key.specified == AVTAB_ALLOWED)
657 					avd->allowed |= node->datum.u.data;
658 				else if (node->key.specified == AVTAB_AUDITALLOW)
659 					avd->auditallow |= node->datum.u.data;
660 				else if (node->key.specified == AVTAB_AUDITDENY)
661 					avd->auditdeny &= node->datum.u.data;
662 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
663 					services_compute_xperms_drivers(xperms, node);
664 			}
665 
666 			/* Check conditional av table for additional permissions */
667 			cond_compute_av(&policydb->te_cond_avtab, &avkey,
668 					avd, xperms);
669 
670 		}
671 	}
672 
673 	/*
674 	 * Remove any permissions prohibited by a constraint (this includes
675 	 * the MLS policy).
676 	 */
677 	constraint = tclass_datum->constraints;
678 	while (constraint) {
679 		if ((constraint->permissions & (avd->allowed)) &&
680 		    !constraint_expr_eval(policydb, scontext, tcontext, NULL,
681 					  constraint->expr)) {
682 			avd->allowed &= ~(constraint->permissions);
683 		}
684 		constraint = constraint->next;
685 	}
686 
687 	/*
688 	 * If checking process transition permission and the
689 	 * role is changing, then check the (current_role, new_role)
690 	 * pair.
691 	 */
692 	if (tclass == policydb->process_class &&
693 	    (avd->allowed & policydb->process_trans_perms) &&
694 	    scontext->role != tcontext->role) {
695 		for (ra = policydb->role_allow; ra; ra = ra->next) {
696 			if (scontext->role == ra->role &&
697 			    tcontext->role == ra->new_role)
698 				break;
699 		}
700 		if (!ra)
701 			avd->allowed &= ~policydb->process_trans_perms;
702 	}
703 
704 	/*
705 	 * If the given source and target types have boundary
706 	 * constraint, lazy checks have to mask any violated
707 	 * permission and notice it to userspace via audit.
708 	 */
709 	type_attribute_bounds_av(policydb, scontext, tcontext,
710 				 tclass, avd);
711 }
712 
713 static int security_validtrans_handle_fail(struct selinux_state *state,
714 					   struct sidtab_entry *oentry,
715 					   struct sidtab_entry *nentry,
716 					   struct sidtab_entry *tentry,
717 					   u16 tclass)
718 {
719 	struct policydb *p = &state->ss->policydb;
720 	struct sidtab *sidtab = state->ss->sidtab;
721 	char *o = NULL, *n = NULL, *t = NULL;
722 	u32 olen, nlen, tlen;
723 
724 	if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
725 		goto out;
726 	if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
727 		goto out;
728 	if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
729 		goto out;
730 	audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
731 		  "op=security_validate_transition seresult=denied"
732 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
733 		  o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
734 out:
735 	kfree(o);
736 	kfree(n);
737 	kfree(t);
738 
739 	if (!enforcing_enabled(state))
740 		return 0;
741 	return -EPERM;
742 }
743 
744 static int security_compute_validatetrans(struct selinux_state *state,
745 					  u32 oldsid, u32 newsid, u32 tasksid,
746 					  u16 orig_tclass, bool user)
747 {
748 	struct policydb *policydb;
749 	struct sidtab *sidtab;
750 	struct sidtab_entry *oentry;
751 	struct sidtab_entry *nentry;
752 	struct sidtab_entry *tentry;
753 	struct class_datum *tclass_datum;
754 	struct constraint_node *constraint;
755 	u16 tclass;
756 	int rc = 0;
757 
758 
759 	if (!selinux_initialized(state))
760 		return 0;
761 
762 	read_lock(&state->ss->policy_rwlock);
763 
764 	policydb = &state->ss->policydb;
765 	sidtab = state->ss->sidtab;
766 
767 	if (!user)
768 		tclass = unmap_class(&state->ss->map, orig_tclass);
769 	else
770 		tclass = orig_tclass;
771 
772 	if (!tclass || tclass > policydb->p_classes.nprim) {
773 		rc = -EINVAL;
774 		goto out;
775 	}
776 	tclass_datum = policydb->class_val_to_struct[tclass - 1];
777 
778 	oentry = sidtab_search_entry(sidtab, oldsid);
779 	if (!oentry) {
780 		pr_err("SELinux: %s:  unrecognized SID %d\n",
781 			__func__, oldsid);
782 		rc = -EINVAL;
783 		goto out;
784 	}
785 
786 	nentry = sidtab_search_entry(sidtab, newsid);
787 	if (!nentry) {
788 		pr_err("SELinux: %s:  unrecognized SID %d\n",
789 			__func__, newsid);
790 		rc = -EINVAL;
791 		goto out;
792 	}
793 
794 	tentry = sidtab_search_entry(sidtab, tasksid);
795 	if (!tentry) {
796 		pr_err("SELinux: %s:  unrecognized SID %d\n",
797 			__func__, tasksid);
798 		rc = -EINVAL;
799 		goto out;
800 	}
801 
802 	constraint = tclass_datum->validatetrans;
803 	while (constraint) {
804 		if (!constraint_expr_eval(policydb, &oentry->context,
805 					  &nentry->context, &tentry->context,
806 					  constraint->expr)) {
807 			if (user)
808 				rc = -EPERM;
809 			else
810 				rc = security_validtrans_handle_fail(state,
811 								     oentry,
812 								     nentry,
813 								     tentry,
814 								     tclass);
815 			goto out;
816 		}
817 		constraint = constraint->next;
818 	}
819 
820 out:
821 	read_unlock(&state->ss->policy_rwlock);
822 	return rc;
823 }
824 
825 int security_validate_transition_user(struct selinux_state *state,
826 				      u32 oldsid, u32 newsid, u32 tasksid,
827 				      u16 tclass)
828 {
829 	return security_compute_validatetrans(state, oldsid, newsid, tasksid,
830 					      tclass, true);
831 }
832 
833 int security_validate_transition(struct selinux_state *state,
834 				 u32 oldsid, u32 newsid, u32 tasksid,
835 				 u16 orig_tclass)
836 {
837 	return security_compute_validatetrans(state, oldsid, newsid, tasksid,
838 					      orig_tclass, false);
839 }
840 
841 /*
842  * security_bounded_transition - check whether the given
843  * transition is directed to bounded, or not.
844  * It returns 0, if @newsid is bounded by @oldsid.
845  * Otherwise, it returns error code.
846  *
847  * @oldsid : current security identifier
848  * @newsid : destinated security identifier
849  */
850 int security_bounded_transition(struct selinux_state *state,
851 				u32 old_sid, u32 new_sid)
852 {
853 	struct policydb *policydb;
854 	struct sidtab *sidtab;
855 	struct sidtab_entry *old_entry, *new_entry;
856 	struct type_datum *type;
857 	int index;
858 	int rc;
859 
860 	if (!selinux_initialized(state))
861 		return 0;
862 
863 	read_lock(&state->ss->policy_rwlock);
864 
865 	policydb = &state->ss->policydb;
866 	sidtab = state->ss->sidtab;
867 
868 	rc = -EINVAL;
869 	old_entry = sidtab_search_entry(sidtab, old_sid);
870 	if (!old_entry) {
871 		pr_err("SELinux: %s: unrecognized SID %u\n",
872 		       __func__, old_sid);
873 		goto out;
874 	}
875 
876 	rc = -EINVAL;
877 	new_entry = sidtab_search_entry(sidtab, new_sid);
878 	if (!new_entry) {
879 		pr_err("SELinux: %s: unrecognized SID %u\n",
880 		       __func__, new_sid);
881 		goto out;
882 	}
883 
884 	rc = 0;
885 	/* type/domain unchanged */
886 	if (old_entry->context.type == new_entry->context.type)
887 		goto out;
888 
889 	index = new_entry->context.type;
890 	while (true) {
891 		type = policydb->type_val_to_struct[index - 1];
892 		BUG_ON(!type);
893 
894 		/* not bounded anymore */
895 		rc = -EPERM;
896 		if (!type->bounds)
897 			break;
898 
899 		/* @newsid is bounded by @oldsid */
900 		rc = 0;
901 		if (type->bounds == old_entry->context.type)
902 			break;
903 
904 		index = type->bounds;
905 	}
906 
907 	if (rc) {
908 		char *old_name = NULL;
909 		char *new_name = NULL;
910 		u32 length;
911 
912 		if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
913 					    &old_name, &length) &&
914 		    !sidtab_entry_to_string(policydb, sidtab, new_entry,
915 					    &new_name, &length)) {
916 			audit_log(audit_context(),
917 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
918 				  "op=security_bounded_transition "
919 				  "seresult=denied "
920 				  "oldcontext=%s newcontext=%s",
921 				  old_name, new_name);
922 		}
923 		kfree(new_name);
924 		kfree(old_name);
925 	}
926 out:
927 	read_unlock(&state->ss->policy_rwlock);
928 
929 	return rc;
930 }
931 
932 static void avd_init(struct selinux_state *state, struct av_decision *avd)
933 {
934 	avd->allowed = 0;
935 	avd->auditallow = 0;
936 	avd->auditdeny = 0xffffffff;
937 	avd->seqno = state->ss->latest_granting;
938 	avd->flags = 0;
939 }
940 
941 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
942 					struct avtab_node *node)
943 {
944 	unsigned int i;
945 
946 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
947 		if (xpermd->driver != node->datum.u.xperms->driver)
948 			return;
949 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
950 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
951 					xpermd->driver))
952 			return;
953 	} else {
954 		BUG();
955 	}
956 
957 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
958 		xpermd->used |= XPERMS_ALLOWED;
959 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
960 			memset(xpermd->allowed->p, 0xff,
961 					sizeof(xpermd->allowed->p));
962 		}
963 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
964 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
965 				xpermd->allowed->p[i] |=
966 					node->datum.u.xperms->perms.p[i];
967 		}
968 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
969 		xpermd->used |= XPERMS_AUDITALLOW;
970 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
971 			memset(xpermd->auditallow->p, 0xff,
972 					sizeof(xpermd->auditallow->p));
973 		}
974 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
975 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
976 				xpermd->auditallow->p[i] |=
977 					node->datum.u.xperms->perms.p[i];
978 		}
979 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
980 		xpermd->used |= XPERMS_DONTAUDIT;
981 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
982 			memset(xpermd->dontaudit->p, 0xff,
983 					sizeof(xpermd->dontaudit->p));
984 		}
985 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
986 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
987 				xpermd->dontaudit->p[i] |=
988 					node->datum.u.xperms->perms.p[i];
989 		}
990 	} else {
991 		BUG();
992 	}
993 }
994 
995 void security_compute_xperms_decision(struct selinux_state *state,
996 				      u32 ssid,
997 				      u32 tsid,
998 				      u16 orig_tclass,
999 				      u8 driver,
1000 				      struct extended_perms_decision *xpermd)
1001 {
1002 	struct policydb *policydb;
1003 	struct sidtab *sidtab;
1004 	u16 tclass;
1005 	struct context *scontext, *tcontext;
1006 	struct avtab_key avkey;
1007 	struct avtab_node *node;
1008 	struct ebitmap *sattr, *tattr;
1009 	struct ebitmap_node *snode, *tnode;
1010 	unsigned int i, j;
1011 
1012 	xpermd->driver = driver;
1013 	xpermd->used = 0;
1014 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1015 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1016 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1017 
1018 	read_lock(&state->ss->policy_rwlock);
1019 	if (!selinux_initialized(state))
1020 		goto allow;
1021 
1022 	policydb = &state->ss->policydb;
1023 	sidtab = state->ss->sidtab;
1024 
1025 	scontext = sidtab_search(sidtab, ssid);
1026 	if (!scontext) {
1027 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1028 		       __func__, ssid);
1029 		goto out;
1030 	}
1031 
1032 	tcontext = sidtab_search(sidtab, tsid);
1033 	if (!tcontext) {
1034 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1035 		       __func__, tsid);
1036 		goto out;
1037 	}
1038 
1039 	tclass = unmap_class(&state->ss->map, orig_tclass);
1040 	if (unlikely(orig_tclass && !tclass)) {
1041 		if (policydb->allow_unknown)
1042 			goto allow;
1043 		goto out;
1044 	}
1045 
1046 
1047 	if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1048 		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1049 		goto out;
1050 	}
1051 
1052 	avkey.target_class = tclass;
1053 	avkey.specified = AVTAB_XPERMS;
1054 	sattr = &policydb->type_attr_map_array[scontext->type - 1];
1055 	tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1056 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1057 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1058 			avkey.source_type = i + 1;
1059 			avkey.target_type = j + 1;
1060 			for (node = avtab_search_node(&policydb->te_avtab,
1061 						      &avkey);
1062 			     node;
1063 			     node = avtab_search_node_next(node, avkey.specified))
1064 				services_compute_xperms_decision(xpermd, node);
1065 
1066 			cond_compute_xperms(&policydb->te_cond_avtab,
1067 						&avkey, xpermd);
1068 		}
1069 	}
1070 out:
1071 	read_unlock(&state->ss->policy_rwlock);
1072 	return;
1073 allow:
1074 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1075 	goto out;
1076 }
1077 
1078 /**
1079  * security_compute_av - Compute access vector decisions.
1080  * @ssid: source security identifier
1081  * @tsid: target security identifier
1082  * @tclass: target security class
1083  * @avd: access vector decisions
1084  * @xperms: extended permissions
1085  *
1086  * Compute a set of access vector decisions based on the
1087  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1088  */
1089 void security_compute_av(struct selinux_state *state,
1090 			 u32 ssid,
1091 			 u32 tsid,
1092 			 u16 orig_tclass,
1093 			 struct av_decision *avd,
1094 			 struct extended_perms *xperms)
1095 {
1096 	struct policydb *policydb;
1097 	struct sidtab *sidtab;
1098 	u16 tclass;
1099 	struct context *scontext = NULL, *tcontext = NULL;
1100 
1101 	read_lock(&state->ss->policy_rwlock);
1102 	avd_init(state, avd);
1103 	xperms->len = 0;
1104 	if (!selinux_initialized(state))
1105 		goto allow;
1106 
1107 	policydb = &state->ss->policydb;
1108 	sidtab = state->ss->sidtab;
1109 
1110 	scontext = sidtab_search(sidtab, ssid);
1111 	if (!scontext) {
1112 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1113 		       __func__, ssid);
1114 		goto out;
1115 	}
1116 
1117 	/* permissive domain? */
1118 	if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1119 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1120 
1121 	tcontext = sidtab_search(sidtab, tsid);
1122 	if (!tcontext) {
1123 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1124 		       __func__, tsid);
1125 		goto out;
1126 	}
1127 
1128 	tclass = unmap_class(&state->ss->map, orig_tclass);
1129 	if (unlikely(orig_tclass && !tclass)) {
1130 		if (policydb->allow_unknown)
1131 			goto allow;
1132 		goto out;
1133 	}
1134 	context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1135 				  xperms);
1136 	map_decision(&state->ss->map, orig_tclass, avd,
1137 		     policydb->allow_unknown);
1138 out:
1139 	read_unlock(&state->ss->policy_rwlock);
1140 	return;
1141 allow:
1142 	avd->allowed = 0xffffffff;
1143 	goto out;
1144 }
1145 
1146 void security_compute_av_user(struct selinux_state *state,
1147 			      u32 ssid,
1148 			      u32 tsid,
1149 			      u16 tclass,
1150 			      struct av_decision *avd)
1151 {
1152 	struct policydb *policydb;
1153 	struct sidtab *sidtab;
1154 	struct context *scontext = NULL, *tcontext = NULL;
1155 
1156 	read_lock(&state->ss->policy_rwlock);
1157 	avd_init(state, avd);
1158 	if (!selinux_initialized(state))
1159 		goto allow;
1160 
1161 	policydb = &state->ss->policydb;
1162 	sidtab = state->ss->sidtab;
1163 
1164 	scontext = sidtab_search(sidtab, ssid);
1165 	if (!scontext) {
1166 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1167 		       __func__, ssid);
1168 		goto out;
1169 	}
1170 
1171 	/* permissive domain? */
1172 	if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1173 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1174 
1175 	tcontext = sidtab_search(sidtab, tsid);
1176 	if (!tcontext) {
1177 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1178 		       __func__, tsid);
1179 		goto out;
1180 	}
1181 
1182 	if (unlikely(!tclass)) {
1183 		if (policydb->allow_unknown)
1184 			goto allow;
1185 		goto out;
1186 	}
1187 
1188 	context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1189 				  NULL);
1190  out:
1191 	read_unlock(&state->ss->policy_rwlock);
1192 	return;
1193 allow:
1194 	avd->allowed = 0xffffffff;
1195 	goto out;
1196 }
1197 
1198 /*
1199  * Write the security context string representation of
1200  * the context structure `context' into a dynamically
1201  * allocated string of the correct size.  Set `*scontext'
1202  * to point to this string and set `*scontext_len' to
1203  * the length of the string.
1204  */
1205 static int context_struct_to_string(struct policydb *p,
1206 				    struct context *context,
1207 				    char **scontext, u32 *scontext_len)
1208 {
1209 	char *scontextp;
1210 
1211 	if (scontext)
1212 		*scontext = NULL;
1213 	*scontext_len = 0;
1214 
1215 	if (context->len) {
1216 		*scontext_len = context->len;
1217 		if (scontext) {
1218 			*scontext = kstrdup(context->str, GFP_ATOMIC);
1219 			if (!(*scontext))
1220 				return -ENOMEM;
1221 		}
1222 		return 0;
1223 	}
1224 
1225 	/* Compute the size of the context. */
1226 	*scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1227 	*scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1228 	*scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1229 	*scontext_len += mls_compute_context_len(p, context);
1230 
1231 	if (!scontext)
1232 		return 0;
1233 
1234 	/* Allocate space for the context; caller must free this space. */
1235 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1236 	if (!scontextp)
1237 		return -ENOMEM;
1238 	*scontext = scontextp;
1239 
1240 	/*
1241 	 * Copy the user name, role name and type name into the context.
1242 	 */
1243 	scontextp += sprintf(scontextp, "%s:%s:%s",
1244 		sym_name(p, SYM_USERS, context->user - 1),
1245 		sym_name(p, SYM_ROLES, context->role - 1),
1246 		sym_name(p, SYM_TYPES, context->type - 1));
1247 
1248 	mls_sid_to_context(p, context, &scontextp);
1249 
1250 	*scontextp = 0;
1251 
1252 	return 0;
1253 }
1254 
1255 static int sidtab_entry_to_string(struct policydb *p,
1256 				  struct sidtab *sidtab,
1257 				  struct sidtab_entry *entry,
1258 				  char **scontext, u32 *scontext_len)
1259 {
1260 	int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1261 
1262 	if (rc != -ENOENT)
1263 		return rc;
1264 
1265 	rc = context_struct_to_string(p, &entry->context, scontext,
1266 				      scontext_len);
1267 	if (!rc && scontext)
1268 		sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1269 	return rc;
1270 }
1271 
1272 #include "initial_sid_to_string.h"
1273 
1274 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1275 {
1276 	int rc;
1277 
1278 	if (!selinux_initialized(state)) {
1279 		pr_err("SELinux: %s:  called before initial load_policy\n",
1280 		       __func__);
1281 		return -EINVAL;
1282 	}
1283 
1284 	read_lock(&state->ss->policy_rwlock);
1285 	rc = sidtab_hash_stats(state->ss->sidtab, page);
1286 	read_unlock(&state->ss->policy_rwlock);
1287 
1288 	return rc;
1289 }
1290 
1291 const char *security_get_initial_sid_context(u32 sid)
1292 {
1293 	if (unlikely(sid > SECINITSID_NUM))
1294 		return NULL;
1295 	return initial_sid_to_string[sid];
1296 }
1297 
1298 static int security_sid_to_context_core(struct selinux_state *state,
1299 					u32 sid, char **scontext,
1300 					u32 *scontext_len, int force,
1301 					int only_invalid)
1302 {
1303 	struct policydb *policydb;
1304 	struct sidtab *sidtab;
1305 	struct sidtab_entry *entry;
1306 	int rc = 0;
1307 
1308 	if (scontext)
1309 		*scontext = NULL;
1310 	*scontext_len  = 0;
1311 
1312 	if (!selinux_initialized(state)) {
1313 		if (sid <= SECINITSID_NUM) {
1314 			char *scontextp;
1315 			const char *s = initial_sid_to_string[sid];
1316 
1317 			if (!s)
1318 				return -EINVAL;
1319 			*scontext_len = strlen(s) + 1;
1320 			if (!scontext)
1321 				return 0;
1322 			scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1323 			if (!scontextp)
1324 				return -ENOMEM;
1325 			*scontext = scontextp;
1326 			return 0;
1327 		}
1328 		pr_err("SELinux: %s:  called before initial "
1329 		       "load_policy on unknown SID %d\n", __func__, sid);
1330 		return -EINVAL;
1331 	}
1332 	read_lock(&state->ss->policy_rwlock);
1333 	policydb = &state->ss->policydb;
1334 	sidtab = state->ss->sidtab;
1335 
1336 	if (force)
1337 		entry = sidtab_search_entry_force(sidtab, sid);
1338 	else
1339 		entry = sidtab_search_entry(sidtab, sid);
1340 	if (!entry) {
1341 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1342 			__func__, sid);
1343 		rc = -EINVAL;
1344 		goto out_unlock;
1345 	}
1346 	if (only_invalid && !entry->context.len)
1347 		goto out_unlock;
1348 
1349 	rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1350 				    scontext_len);
1351 
1352 out_unlock:
1353 	read_unlock(&state->ss->policy_rwlock);
1354 	return rc;
1355 
1356 }
1357 
1358 /**
1359  * security_sid_to_context - Obtain a context for a given SID.
1360  * @sid: security identifier, SID
1361  * @scontext: security context
1362  * @scontext_len: length in bytes
1363  *
1364  * Write the string representation of the context associated with @sid
1365  * into a dynamically allocated string of the correct size.  Set @scontext
1366  * to point to this string and set @scontext_len to the length of the string.
1367  */
1368 int security_sid_to_context(struct selinux_state *state,
1369 			    u32 sid, char **scontext, u32 *scontext_len)
1370 {
1371 	return security_sid_to_context_core(state, sid, scontext,
1372 					    scontext_len, 0, 0);
1373 }
1374 
1375 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1376 				  char **scontext, u32 *scontext_len)
1377 {
1378 	return security_sid_to_context_core(state, sid, scontext,
1379 					    scontext_len, 1, 0);
1380 }
1381 
1382 /**
1383  * security_sid_to_context_inval - Obtain a context for a given SID if it
1384  *                                 is invalid.
1385  * @sid: security identifier, SID
1386  * @scontext: security context
1387  * @scontext_len: length in bytes
1388  *
1389  * Write the string representation of the context associated with @sid
1390  * into a dynamically allocated string of the correct size, but only if the
1391  * context is invalid in the current policy.  Set @scontext to point to
1392  * this string (or NULL if the context is valid) and set @scontext_len to
1393  * the length of the string (or 0 if the context is valid).
1394  */
1395 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1396 				  char **scontext, u32 *scontext_len)
1397 {
1398 	return security_sid_to_context_core(state, sid, scontext,
1399 					    scontext_len, 1, 1);
1400 }
1401 
1402 /*
1403  * Caveat:  Mutates scontext.
1404  */
1405 static int string_to_context_struct(struct policydb *pol,
1406 				    struct sidtab *sidtabp,
1407 				    char *scontext,
1408 				    struct context *ctx,
1409 				    u32 def_sid)
1410 {
1411 	struct role_datum *role;
1412 	struct type_datum *typdatum;
1413 	struct user_datum *usrdatum;
1414 	char *scontextp, *p, oldc;
1415 	int rc = 0;
1416 
1417 	context_init(ctx);
1418 
1419 	/* Parse the security context. */
1420 
1421 	rc = -EINVAL;
1422 	scontextp = (char *) scontext;
1423 
1424 	/* Extract the user. */
1425 	p = scontextp;
1426 	while (*p && *p != ':')
1427 		p++;
1428 
1429 	if (*p == 0)
1430 		goto out;
1431 
1432 	*p++ = 0;
1433 
1434 	usrdatum = symtab_search(&pol->p_users, scontextp);
1435 	if (!usrdatum)
1436 		goto out;
1437 
1438 	ctx->user = usrdatum->value;
1439 
1440 	/* Extract role. */
1441 	scontextp = p;
1442 	while (*p && *p != ':')
1443 		p++;
1444 
1445 	if (*p == 0)
1446 		goto out;
1447 
1448 	*p++ = 0;
1449 
1450 	role = symtab_search(&pol->p_roles, scontextp);
1451 	if (!role)
1452 		goto out;
1453 	ctx->role = role->value;
1454 
1455 	/* Extract type. */
1456 	scontextp = p;
1457 	while (*p && *p != ':')
1458 		p++;
1459 	oldc = *p;
1460 	*p++ = 0;
1461 
1462 	typdatum = symtab_search(&pol->p_types, scontextp);
1463 	if (!typdatum || typdatum->attribute)
1464 		goto out;
1465 
1466 	ctx->type = typdatum->value;
1467 
1468 	rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1469 	if (rc)
1470 		goto out;
1471 
1472 	/* Check the validity of the new context. */
1473 	rc = -EINVAL;
1474 	if (!policydb_context_isvalid(pol, ctx))
1475 		goto out;
1476 	rc = 0;
1477 out:
1478 	if (rc)
1479 		context_destroy(ctx);
1480 	return rc;
1481 }
1482 
1483 static int security_context_to_sid_core(struct selinux_state *state,
1484 					const char *scontext, u32 scontext_len,
1485 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1486 					int force)
1487 {
1488 	struct policydb *policydb;
1489 	struct sidtab *sidtab;
1490 	char *scontext2, *str = NULL;
1491 	struct context context;
1492 	int rc = 0;
1493 
1494 	/* An empty security context is never valid. */
1495 	if (!scontext_len)
1496 		return -EINVAL;
1497 
1498 	/* Copy the string to allow changes and ensure a NUL terminator */
1499 	scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1500 	if (!scontext2)
1501 		return -ENOMEM;
1502 
1503 	if (!selinux_initialized(state)) {
1504 		int i;
1505 
1506 		for (i = 1; i < SECINITSID_NUM; i++) {
1507 			const char *s = initial_sid_to_string[i];
1508 
1509 			if (s && !strcmp(s, scontext2)) {
1510 				*sid = i;
1511 				goto out;
1512 			}
1513 		}
1514 		*sid = SECINITSID_KERNEL;
1515 		goto out;
1516 	}
1517 	*sid = SECSID_NULL;
1518 
1519 	if (force) {
1520 		/* Save another copy for storing in uninterpreted form */
1521 		rc = -ENOMEM;
1522 		str = kstrdup(scontext2, gfp_flags);
1523 		if (!str)
1524 			goto out;
1525 	}
1526 	read_lock(&state->ss->policy_rwlock);
1527 	policydb = &state->ss->policydb;
1528 	sidtab = state->ss->sidtab;
1529 	rc = string_to_context_struct(policydb, sidtab, scontext2,
1530 				      &context, def_sid);
1531 	if (rc == -EINVAL && force) {
1532 		context.str = str;
1533 		context.len = strlen(str) + 1;
1534 		str = NULL;
1535 	} else if (rc)
1536 		goto out_unlock;
1537 	rc = sidtab_context_to_sid(sidtab, &context, sid);
1538 	context_destroy(&context);
1539 out_unlock:
1540 	read_unlock(&state->ss->policy_rwlock);
1541 out:
1542 	kfree(scontext2);
1543 	kfree(str);
1544 	return rc;
1545 }
1546 
1547 /**
1548  * security_context_to_sid - Obtain a SID for a given security context.
1549  * @scontext: security context
1550  * @scontext_len: length in bytes
1551  * @sid: security identifier, SID
1552  * @gfp: context for the allocation
1553  *
1554  * Obtains a SID associated with the security context that
1555  * has the string representation specified by @scontext.
1556  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1557  * memory is available, or 0 on success.
1558  */
1559 int security_context_to_sid(struct selinux_state *state,
1560 			    const char *scontext, u32 scontext_len, u32 *sid,
1561 			    gfp_t gfp)
1562 {
1563 	return security_context_to_sid_core(state, scontext, scontext_len,
1564 					    sid, SECSID_NULL, gfp, 0);
1565 }
1566 
1567 int security_context_str_to_sid(struct selinux_state *state,
1568 				const char *scontext, u32 *sid, gfp_t gfp)
1569 {
1570 	return security_context_to_sid(state, scontext, strlen(scontext),
1571 				       sid, gfp);
1572 }
1573 
1574 /**
1575  * security_context_to_sid_default - Obtain a SID for a given security context,
1576  * falling back to specified default if needed.
1577  *
1578  * @scontext: security context
1579  * @scontext_len: length in bytes
1580  * @sid: security identifier, SID
1581  * @def_sid: default SID to assign on error
1582  *
1583  * Obtains a SID associated with the security context that
1584  * has the string representation specified by @scontext.
1585  * The default SID is passed to the MLS layer to be used to allow
1586  * kernel labeling of the MLS field if the MLS field is not present
1587  * (for upgrading to MLS without full relabel).
1588  * Implicitly forces adding of the context even if it cannot be mapped yet.
1589  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1590  * memory is available, or 0 on success.
1591  */
1592 int security_context_to_sid_default(struct selinux_state *state,
1593 				    const char *scontext, u32 scontext_len,
1594 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1595 {
1596 	return security_context_to_sid_core(state, scontext, scontext_len,
1597 					    sid, def_sid, gfp_flags, 1);
1598 }
1599 
1600 int security_context_to_sid_force(struct selinux_state *state,
1601 				  const char *scontext, u32 scontext_len,
1602 				  u32 *sid)
1603 {
1604 	return security_context_to_sid_core(state, scontext, scontext_len,
1605 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1606 }
1607 
1608 static int compute_sid_handle_invalid_context(
1609 	struct selinux_state *state,
1610 	struct sidtab_entry *sentry,
1611 	struct sidtab_entry *tentry,
1612 	u16 tclass,
1613 	struct context *newcontext)
1614 {
1615 	struct policydb *policydb = &state->ss->policydb;
1616 	struct sidtab *sidtab = state->ss->sidtab;
1617 	char *s = NULL, *t = NULL, *n = NULL;
1618 	u32 slen, tlen, nlen;
1619 	struct audit_buffer *ab;
1620 
1621 	if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1622 		goto out;
1623 	if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1624 		goto out;
1625 	if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1626 		goto out;
1627 	ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1628 	audit_log_format(ab,
1629 			 "op=security_compute_sid invalid_context=");
1630 	/* no need to record the NUL with untrusted strings */
1631 	audit_log_n_untrustedstring(ab, n, nlen - 1);
1632 	audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1633 			 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1634 	audit_log_end(ab);
1635 out:
1636 	kfree(s);
1637 	kfree(t);
1638 	kfree(n);
1639 	if (!enforcing_enabled(state))
1640 		return 0;
1641 	return -EACCES;
1642 }
1643 
1644 static void filename_compute_type(struct policydb *policydb,
1645 				  struct context *newcontext,
1646 				  u32 stype, u32 ttype, u16 tclass,
1647 				  const char *objname)
1648 {
1649 	struct filename_trans_key ft;
1650 	struct filename_trans_datum *datum;
1651 
1652 	/*
1653 	 * Most filename trans rules are going to live in specific directories
1654 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1655 	 * if the ttype does not contain any rules.
1656 	 */
1657 	if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1658 		return;
1659 
1660 	ft.ttype = ttype;
1661 	ft.tclass = tclass;
1662 	ft.name = objname;
1663 
1664 	datum = policydb_filenametr_search(policydb, &ft);
1665 	while (datum) {
1666 		if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1667 			newcontext->type = datum->otype;
1668 			return;
1669 		}
1670 		datum = datum->next;
1671 	}
1672 }
1673 
1674 static int security_compute_sid(struct selinux_state *state,
1675 				u32 ssid,
1676 				u32 tsid,
1677 				u16 orig_tclass,
1678 				u32 specified,
1679 				const char *objname,
1680 				u32 *out_sid,
1681 				bool kern)
1682 {
1683 	struct policydb *policydb;
1684 	struct sidtab *sidtab;
1685 	struct class_datum *cladatum = NULL;
1686 	struct context *scontext, *tcontext, newcontext;
1687 	struct sidtab_entry *sentry, *tentry;
1688 	struct avtab_key avkey;
1689 	struct avtab_datum *avdatum;
1690 	struct avtab_node *node;
1691 	u16 tclass;
1692 	int rc = 0;
1693 	bool sock;
1694 
1695 	if (!selinux_initialized(state)) {
1696 		switch (orig_tclass) {
1697 		case SECCLASS_PROCESS: /* kernel value */
1698 			*out_sid = ssid;
1699 			break;
1700 		default:
1701 			*out_sid = tsid;
1702 			break;
1703 		}
1704 		goto out;
1705 	}
1706 
1707 	context_init(&newcontext);
1708 
1709 	read_lock(&state->ss->policy_rwlock);
1710 
1711 	if (kern) {
1712 		tclass = unmap_class(&state->ss->map, orig_tclass);
1713 		sock = security_is_socket_class(orig_tclass);
1714 	} else {
1715 		tclass = orig_tclass;
1716 		sock = security_is_socket_class(map_class(&state->ss->map,
1717 							  tclass));
1718 	}
1719 
1720 	policydb = &state->ss->policydb;
1721 	sidtab = state->ss->sidtab;
1722 
1723 	sentry = sidtab_search_entry(sidtab, ssid);
1724 	if (!sentry) {
1725 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1726 		       __func__, ssid);
1727 		rc = -EINVAL;
1728 		goto out_unlock;
1729 	}
1730 	tentry = sidtab_search_entry(sidtab, tsid);
1731 	if (!tentry) {
1732 		pr_err("SELinux: %s:  unrecognized SID %d\n",
1733 		       __func__, tsid);
1734 		rc = -EINVAL;
1735 		goto out_unlock;
1736 	}
1737 
1738 	scontext = &sentry->context;
1739 	tcontext = &tentry->context;
1740 
1741 	if (tclass && tclass <= policydb->p_classes.nprim)
1742 		cladatum = policydb->class_val_to_struct[tclass - 1];
1743 
1744 	/* Set the user identity. */
1745 	switch (specified) {
1746 	case AVTAB_TRANSITION:
1747 	case AVTAB_CHANGE:
1748 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1749 			newcontext.user = tcontext->user;
1750 		} else {
1751 			/* notice this gets both DEFAULT_SOURCE and unset */
1752 			/* Use the process user identity. */
1753 			newcontext.user = scontext->user;
1754 		}
1755 		break;
1756 	case AVTAB_MEMBER:
1757 		/* Use the related object owner. */
1758 		newcontext.user = tcontext->user;
1759 		break;
1760 	}
1761 
1762 	/* Set the role to default values. */
1763 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1764 		newcontext.role = scontext->role;
1765 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1766 		newcontext.role = tcontext->role;
1767 	} else {
1768 		if ((tclass == policydb->process_class) || sock)
1769 			newcontext.role = scontext->role;
1770 		else
1771 			newcontext.role = OBJECT_R_VAL;
1772 	}
1773 
1774 	/* Set the type to default values. */
1775 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1776 		newcontext.type = scontext->type;
1777 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1778 		newcontext.type = tcontext->type;
1779 	} else {
1780 		if ((tclass == policydb->process_class) || sock) {
1781 			/* Use the type of process. */
1782 			newcontext.type = scontext->type;
1783 		} else {
1784 			/* Use the type of the related object. */
1785 			newcontext.type = tcontext->type;
1786 		}
1787 	}
1788 
1789 	/* Look for a type transition/member/change rule. */
1790 	avkey.source_type = scontext->type;
1791 	avkey.target_type = tcontext->type;
1792 	avkey.target_class = tclass;
1793 	avkey.specified = specified;
1794 	avdatum = avtab_search(&policydb->te_avtab, &avkey);
1795 
1796 	/* If no permanent rule, also check for enabled conditional rules */
1797 	if (!avdatum) {
1798 		node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1799 		for (; node; node = avtab_search_node_next(node, specified)) {
1800 			if (node->key.specified & AVTAB_ENABLED) {
1801 				avdatum = &node->datum;
1802 				break;
1803 			}
1804 		}
1805 	}
1806 
1807 	if (avdatum) {
1808 		/* Use the type from the type transition/member/change rule. */
1809 		newcontext.type = avdatum->u.data;
1810 	}
1811 
1812 	/* if we have a objname this is a file trans check so check those rules */
1813 	if (objname)
1814 		filename_compute_type(policydb, &newcontext, scontext->type,
1815 				      tcontext->type, tclass, objname);
1816 
1817 	/* Check for class-specific changes. */
1818 	if (specified & AVTAB_TRANSITION) {
1819 		/* Look for a role transition rule. */
1820 		struct role_trans_datum *rtd;
1821 		struct role_trans_key rtk = {
1822 			.role = scontext->role,
1823 			.type = tcontext->type,
1824 			.tclass = tclass,
1825 		};
1826 
1827 		rtd = policydb_roletr_search(policydb, &rtk);
1828 		if (rtd)
1829 			newcontext.role = rtd->new_role;
1830 	}
1831 
1832 	/* Set the MLS attributes.
1833 	   This is done last because it may allocate memory. */
1834 	rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1835 			     &newcontext, sock);
1836 	if (rc)
1837 		goto out_unlock;
1838 
1839 	/* Check the validity of the context. */
1840 	if (!policydb_context_isvalid(policydb, &newcontext)) {
1841 		rc = compute_sid_handle_invalid_context(state, sentry, tentry,
1842 							tclass, &newcontext);
1843 		if (rc)
1844 			goto out_unlock;
1845 	}
1846 	/* Obtain the sid for the context. */
1847 	rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1848 out_unlock:
1849 	read_unlock(&state->ss->policy_rwlock);
1850 	context_destroy(&newcontext);
1851 out:
1852 	return rc;
1853 }
1854 
1855 /**
1856  * security_transition_sid - Compute the SID for a new subject/object.
1857  * @ssid: source security identifier
1858  * @tsid: target security identifier
1859  * @tclass: target security class
1860  * @out_sid: security identifier for new subject/object
1861  *
1862  * Compute a SID to use for labeling a new subject or object in the
1863  * class @tclass based on a SID pair (@ssid, @tsid).
1864  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1865  * if insufficient memory is available, or %0 if the new SID was
1866  * computed successfully.
1867  */
1868 int security_transition_sid(struct selinux_state *state,
1869 			    u32 ssid, u32 tsid, u16 tclass,
1870 			    const struct qstr *qstr, u32 *out_sid)
1871 {
1872 	return security_compute_sid(state, ssid, tsid, tclass,
1873 				    AVTAB_TRANSITION,
1874 				    qstr ? qstr->name : NULL, out_sid, true);
1875 }
1876 
1877 int security_transition_sid_user(struct selinux_state *state,
1878 				 u32 ssid, u32 tsid, u16 tclass,
1879 				 const char *objname, u32 *out_sid)
1880 {
1881 	return security_compute_sid(state, ssid, tsid, tclass,
1882 				    AVTAB_TRANSITION,
1883 				    objname, out_sid, false);
1884 }
1885 
1886 /**
1887  * security_member_sid - Compute the SID for member selection.
1888  * @ssid: source security identifier
1889  * @tsid: target security identifier
1890  * @tclass: target security class
1891  * @out_sid: security identifier for selected member
1892  *
1893  * Compute a SID to use when selecting a member of a polyinstantiated
1894  * object of class @tclass based on a SID pair (@ssid, @tsid).
1895  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1896  * if insufficient memory is available, or %0 if the SID was
1897  * computed successfully.
1898  */
1899 int security_member_sid(struct selinux_state *state,
1900 			u32 ssid,
1901 			u32 tsid,
1902 			u16 tclass,
1903 			u32 *out_sid)
1904 {
1905 	return security_compute_sid(state, ssid, tsid, tclass,
1906 				    AVTAB_MEMBER, NULL,
1907 				    out_sid, false);
1908 }
1909 
1910 /**
1911  * security_change_sid - Compute the SID for object relabeling.
1912  * @ssid: source security identifier
1913  * @tsid: target security identifier
1914  * @tclass: target security class
1915  * @out_sid: security identifier for selected member
1916  *
1917  * Compute a SID to use for relabeling an object of class @tclass
1918  * based on a SID pair (@ssid, @tsid).
1919  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1920  * if insufficient memory is available, or %0 if the SID was
1921  * computed successfully.
1922  */
1923 int security_change_sid(struct selinux_state *state,
1924 			u32 ssid,
1925 			u32 tsid,
1926 			u16 tclass,
1927 			u32 *out_sid)
1928 {
1929 	return security_compute_sid(state,
1930 				    ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1931 				    out_sid, false);
1932 }
1933 
1934 static inline int convert_context_handle_invalid_context(
1935 	struct selinux_state *state,
1936 	struct context *context)
1937 {
1938 	struct policydb *policydb = &state->ss->policydb;
1939 	char *s;
1940 	u32 len;
1941 
1942 	if (enforcing_enabled(state))
1943 		return -EINVAL;
1944 
1945 	if (!context_struct_to_string(policydb, context, &s, &len)) {
1946 		pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
1947 			s);
1948 		kfree(s);
1949 	}
1950 	return 0;
1951 }
1952 
1953 struct convert_context_args {
1954 	struct selinux_state *state;
1955 	struct policydb *oldp;
1956 	struct policydb *newp;
1957 };
1958 
1959 /*
1960  * Convert the values in the security context
1961  * structure `oldc' from the values specified
1962  * in the policy `p->oldp' to the values specified
1963  * in the policy `p->newp', storing the new context
1964  * in `newc'.  Verify that the context is valid
1965  * under the new policy.
1966  */
1967 static int convert_context(struct context *oldc, struct context *newc, void *p)
1968 {
1969 	struct convert_context_args *args;
1970 	struct ocontext *oc;
1971 	struct role_datum *role;
1972 	struct type_datum *typdatum;
1973 	struct user_datum *usrdatum;
1974 	char *s;
1975 	u32 len;
1976 	int rc;
1977 
1978 	args = p;
1979 
1980 	if (oldc->str) {
1981 		s = kstrdup(oldc->str, GFP_KERNEL);
1982 		if (!s)
1983 			return -ENOMEM;
1984 
1985 		rc = string_to_context_struct(args->newp, NULL, s,
1986 					      newc, SECSID_NULL);
1987 		if (rc == -EINVAL) {
1988 			/*
1989 			 * Retain string representation for later mapping.
1990 			 *
1991 			 * IMPORTANT: We need to copy the contents of oldc->str
1992 			 * back into s again because string_to_context_struct()
1993 			 * may have garbled it.
1994 			 */
1995 			memcpy(s, oldc->str, oldc->len);
1996 			context_init(newc);
1997 			newc->str = s;
1998 			newc->len = oldc->len;
1999 			return 0;
2000 		}
2001 		kfree(s);
2002 		if (rc) {
2003 			/* Other error condition, e.g. ENOMEM. */
2004 			pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2005 			       oldc->str, -rc);
2006 			return rc;
2007 		}
2008 		pr_info("SELinux:  Context %s became valid (mapped).\n",
2009 			oldc->str);
2010 		return 0;
2011 	}
2012 
2013 	context_init(newc);
2014 
2015 	/* Convert the user. */
2016 	rc = -EINVAL;
2017 	usrdatum = symtab_search(&args->newp->p_users,
2018 				 sym_name(args->oldp,
2019 					  SYM_USERS, oldc->user - 1));
2020 	if (!usrdatum)
2021 		goto bad;
2022 	newc->user = usrdatum->value;
2023 
2024 	/* Convert the role. */
2025 	rc = -EINVAL;
2026 	role = symtab_search(&args->newp->p_roles,
2027 			     sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2028 	if (!role)
2029 		goto bad;
2030 	newc->role = role->value;
2031 
2032 	/* Convert the type. */
2033 	rc = -EINVAL;
2034 	typdatum = symtab_search(&args->newp->p_types,
2035 				 sym_name(args->oldp,
2036 					  SYM_TYPES, oldc->type - 1));
2037 	if (!typdatum)
2038 		goto bad;
2039 	newc->type = typdatum->value;
2040 
2041 	/* Convert the MLS fields if dealing with MLS policies */
2042 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2043 		rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2044 		if (rc)
2045 			goto bad;
2046 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2047 		/*
2048 		 * Switching between non-MLS and MLS policy:
2049 		 * ensure that the MLS fields of the context for all
2050 		 * existing entries in the sidtab are filled in with a
2051 		 * suitable default value, likely taken from one of the
2052 		 * initial SIDs.
2053 		 */
2054 		oc = args->newp->ocontexts[OCON_ISID];
2055 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2056 			oc = oc->next;
2057 		rc = -EINVAL;
2058 		if (!oc) {
2059 			pr_err("SELinux:  unable to look up"
2060 				" the initial SIDs list\n");
2061 			goto bad;
2062 		}
2063 		rc = mls_range_set(newc, &oc->context[0].range);
2064 		if (rc)
2065 			goto bad;
2066 	}
2067 
2068 	/* Check the validity of the new context. */
2069 	if (!policydb_context_isvalid(args->newp, newc)) {
2070 		rc = convert_context_handle_invalid_context(args->state, oldc);
2071 		if (rc)
2072 			goto bad;
2073 	}
2074 
2075 	return 0;
2076 bad:
2077 	/* Map old representation to string and save it. */
2078 	rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2079 	if (rc)
2080 		return rc;
2081 	context_destroy(newc);
2082 	newc->str = s;
2083 	newc->len = len;
2084 	pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2085 		newc->str);
2086 	return 0;
2087 }
2088 
2089 static void security_load_policycaps(struct selinux_state *state)
2090 {
2091 	struct policydb *p = &state->ss->policydb;
2092 	unsigned int i;
2093 	struct ebitmap_node *node;
2094 
2095 	for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2096 		state->policycap[i] = ebitmap_get_bit(&p->policycaps, i);
2097 
2098 	for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2099 		pr_info("SELinux:  policy capability %s=%d\n",
2100 			selinux_policycap_names[i],
2101 			ebitmap_get_bit(&p->policycaps, i));
2102 
2103 	ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2104 		if (i >= ARRAY_SIZE(selinux_policycap_names))
2105 			pr_info("SELinux:  unknown policy capability %u\n",
2106 				i);
2107 	}
2108 }
2109 
2110 static int security_preserve_bools(struct selinux_state *state,
2111 				   struct policydb *newpolicydb);
2112 
2113 /**
2114  * security_load_policy - Load a security policy configuration.
2115  * @data: binary policy data
2116  * @len: length of data in bytes
2117  *
2118  * Load a new set of security policy configuration data,
2119  * validate it and convert the SID table as necessary.
2120  * This function will flush the access vector cache after
2121  * loading the new policy.
2122  */
2123 int security_load_policy(struct selinux_state *state, void *data, size_t len)
2124 {
2125 	struct policydb *policydb;
2126 	struct sidtab *oldsidtab, *newsidtab;
2127 	struct policydb *oldpolicydb, *newpolicydb;
2128 	struct selinux_mapping *oldmapping;
2129 	struct selinux_map newmap;
2130 	struct sidtab_convert_params convert_params;
2131 	struct convert_context_args args;
2132 	u32 seqno;
2133 	int rc = 0;
2134 	struct policy_file file = { data, len }, *fp = &file;
2135 
2136 	policydb = &state->ss->policydb;
2137 
2138 	newsidtab = kmalloc(sizeof(*newsidtab), GFP_KERNEL);
2139 	if (!newsidtab)
2140 		return -ENOMEM;
2141 
2142 	if (!selinux_initialized(state)) {
2143 		rc = policydb_read(policydb, fp);
2144 		if (rc) {
2145 			kfree(newsidtab);
2146 			return rc;
2147 		}
2148 
2149 		policydb->len = len;
2150 		rc = selinux_set_mapping(policydb, secclass_map,
2151 					 &state->ss->map);
2152 		if (rc) {
2153 			kfree(newsidtab);
2154 			policydb_destroy(policydb);
2155 			return rc;
2156 		}
2157 
2158 		rc = policydb_load_isids(policydb, newsidtab);
2159 		if (rc) {
2160 			kfree(newsidtab);
2161 			policydb_destroy(policydb);
2162 			return rc;
2163 		}
2164 
2165 		state->ss->sidtab = newsidtab;
2166 		security_load_policycaps(state);
2167 		selinux_mark_initialized(state);
2168 		seqno = ++state->ss->latest_granting;
2169 		selinux_complete_init();
2170 		avc_ss_reset(state->avc, seqno);
2171 		selnl_notify_policyload(seqno);
2172 		selinux_status_update_policyload(state, seqno);
2173 		selinux_netlbl_cache_invalidate();
2174 		selinux_xfrm_notify_policyload();
2175 		return 0;
2176 	}
2177 
2178 	oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL);
2179 	if (!oldpolicydb) {
2180 		kfree(newsidtab);
2181 		return -ENOMEM;
2182 	}
2183 	newpolicydb = oldpolicydb + 1;
2184 
2185 	rc = policydb_read(newpolicydb, fp);
2186 	if (rc) {
2187 		kfree(newsidtab);
2188 		goto out;
2189 	}
2190 
2191 	newpolicydb->len = len;
2192 	/* If switching between different policy types, log MLS status */
2193 	if (policydb->mls_enabled && !newpolicydb->mls_enabled)
2194 		pr_info("SELinux: Disabling MLS support...\n");
2195 	else if (!policydb->mls_enabled && newpolicydb->mls_enabled)
2196 		pr_info("SELinux: Enabling MLS support...\n");
2197 
2198 	rc = policydb_load_isids(newpolicydb, newsidtab);
2199 	if (rc) {
2200 		pr_err("SELinux:  unable to load the initial SIDs\n");
2201 		policydb_destroy(newpolicydb);
2202 		kfree(newsidtab);
2203 		goto out;
2204 	}
2205 
2206 	rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap);
2207 	if (rc)
2208 		goto err;
2209 
2210 	rc = security_preserve_bools(state, newpolicydb);
2211 	if (rc) {
2212 		pr_err("SELinux:  unable to preserve booleans\n");
2213 		goto err;
2214 	}
2215 
2216 	oldsidtab = state->ss->sidtab;
2217 
2218 	/*
2219 	 * Convert the internal representations of contexts
2220 	 * in the new SID table.
2221 	 */
2222 	args.state = state;
2223 	args.oldp = policydb;
2224 	args.newp = newpolicydb;
2225 
2226 	convert_params.func = convert_context;
2227 	convert_params.args = &args;
2228 	convert_params.target = newsidtab;
2229 
2230 	rc = sidtab_convert(oldsidtab, &convert_params);
2231 	if (rc) {
2232 		pr_err("SELinux:  unable to convert the internal"
2233 			" representation of contexts in the new SID"
2234 			" table\n");
2235 		goto err;
2236 	}
2237 
2238 	/* Save the old policydb and SID table to free later. */
2239 	memcpy(oldpolicydb, policydb, sizeof(*policydb));
2240 
2241 	/* Install the new policydb and SID table. */
2242 	write_lock_irq(&state->ss->policy_rwlock);
2243 	memcpy(policydb, newpolicydb, sizeof(*policydb));
2244 	state->ss->sidtab = newsidtab;
2245 	security_load_policycaps(state);
2246 	oldmapping = state->ss->map.mapping;
2247 	state->ss->map.mapping = newmap.mapping;
2248 	state->ss->map.size = newmap.size;
2249 	seqno = ++state->ss->latest_granting;
2250 	write_unlock_irq(&state->ss->policy_rwlock);
2251 
2252 	/* Free the old policydb and SID table. */
2253 	policydb_destroy(oldpolicydb);
2254 	sidtab_destroy(oldsidtab);
2255 	kfree(oldsidtab);
2256 	kfree(oldmapping);
2257 
2258 	avc_ss_reset(state->avc, seqno);
2259 	selnl_notify_policyload(seqno);
2260 	selinux_status_update_policyload(state, seqno);
2261 	selinux_netlbl_cache_invalidate();
2262 	selinux_xfrm_notify_policyload();
2263 
2264 	rc = 0;
2265 	goto out;
2266 
2267 err:
2268 	kfree(newmap.mapping);
2269 	sidtab_destroy(newsidtab);
2270 	kfree(newsidtab);
2271 	policydb_destroy(newpolicydb);
2272 
2273 out:
2274 	kfree(oldpolicydb);
2275 	return rc;
2276 }
2277 
2278 size_t security_policydb_len(struct selinux_state *state)
2279 {
2280 	struct policydb *p = &state->ss->policydb;
2281 	size_t len;
2282 
2283 	read_lock(&state->ss->policy_rwlock);
2284 	len = p->len;
2285 	read_unlock(&state->ss->policy_rwlock);
2286 
2287 	return len;
2288 }
2289 
2290 /**
2291  * security_port_sid - Obtain the SID for a port.
2292  * @protocol: protocol number
2293  * @port: port number
2294  * @out_sid: security identifier
2295  */
2296 int security_port_sid(struct selinux_state *state,
2297 		      u8 protocol, u16 port, u32 *out_sid)
2298 {
2299 	struct policydb *policydb;
2300 	struct sidtab *sidtab;
2301 	struct ocontext *c;
2302 	int rc = 0;
2303 
2304 	read_lock(&state->ss->policy_rwlock);
2305 
2306 	policydb = &state->ss->policydb;
2307 	sidtab = state->ss->sidtab;
2308 
2309 	c = policydb->ocontexts[OCON_PORT];
2310 	while (c) {
2311 		if (c->u.port.protocol == protocol &&
2312 		    c->u.port.low_port <= port &&
2313 		    c->u.port.high_port >= port)
2314 			break;
2315 		c = c->next;
2316 	}
2317 
2318 	if (c) {
2319 		if (!c->sid[0]) {
2320 			rc = sidtab_context_to_sid(sidtab, &c->context[0],
2321 						   &c->sid[0]);
2322 			if (rc)
2323 				goto out;
2324 		}
2325 		*out_sid = c->sid[0];
2326 	} else {
2327 		*out_sid = SECINITSID_PORT;
2328 	}
2329 
2330 out:
2331 	read_unlock(&state->ss->policy_rwlock);
2332 	return rc;
2333 }
2334 
2335 /**
2336  * security_pkey_sid - Obtain the SID for a pkey.
2337  * @subnet_prefix: Subnet Prefix
2338  * @pkey_num: pkey number
2339  * @out_sid: security identifier
2340  */
2341 int security_ib_pkey_sid(struct selinux_state *state,
2342 			 u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2343 {
2344 	struct policydb *policydb;
2345 	struct sidtab *sidtab;
2346 	struct ocontext *c;
2347 	int rc = 0;
2348 
2349 	read_lock(&state->ss->policy_rwlock);
2350 
2351 	policydb = &state->ss->policydb;
2352 	sidtab = state->ss->sidtab;
2353 
2354 	c = policydb->ocontexts[OCON_IBPKEY];
2355 	while (c) {
2356 		if (c->u.ibpkey.low_pkey <= pkey_num &&
2357 		    c->u.ibpkey.high_pkey >= pkey_num &&
2358 		    c->u.ibpkey.subnet_prefix == subnet_prefix)
2359 			break;
2360 
2361 		c = c->next;
2362 	}
2363 
2364 	if (c) {
2365 		if (!c->sid[0]) {
2366 			rc = sidtab_context_to_sid(sidtab,
2367 						   &c->context[0],
2368 						   &c->sid[0]);
2369 			if (rc)
2370 				goto out;
2371 		}
2372 		*out_sid = c->sid[0];
2373 	} else
2374 		*out_sid = SECINITSID_UNLABELED;
2375 
2376 out:
2377 	read_unlock(&state->ss->policy_rwlock);
2378 	return rc;
2379 }
2380 
2381 /**
2382  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2383  * @dev_name: device name
2384  * @port: port number
2385  * @out_sid: security identifier
2386  */
2387 int security_ib_endport_sid(struct selinux_state *state,
2388 			    const char *dev_name, u8 port_num, u32 *out_sid)
2389 {
2390 	struct policydb *policydb;
2391 	struct sidtab *sidtab;
2392 	struct ocontext *c;
2393 	int rc = 0;
2394 
2395 	read_lock(&state->ss->policy_rwlock);
2396 
2397 	policydb = &state->ss->policydb;
2398 	sidtab = state->ss->sidtab;
2399 
2400 	c = policydb->ocontexts[OCON_IBENDPORT];
2401 	while (c) {
2402 		if (c->u.ibendport.port == port_num &&
2403 		    !strncmp(c->u.ibendport.dev_name,
2404 			     dev_name,
2405 			     IB_DEVICE_NAME_MAX))
2406 			break;
2407 
2408 		c = c->next;
2409 	}
2410 
2411 	if (c) {
2412 		if (!c->sid[0]) {
2413 			rc = sidtab_context_to_sid(sidtab, &c->context[0],
2414 						   &c->sid[0]);
2415 			if (rc)
2416 				goto out;
2417 		}
2418 		*out_sid = c->sid[0];
2419 	} else
2420 		*out_sid = SECINITSID_UNLABELED;
2421 
2422 out:
2423 	read_unlock(&state->ss->policy_rwlock);
2424 	return rc;
2425 }
2426 
2427 /**
2428  * security_netif_sid - Obtain the SID for a network interface.
2429  * @name: interface name
2430  * @if_sid: interface SID
2431  */
2432 int security_netif_sid(struct selinux_state *state,
2433 		       char *name, u32 *if_sid)
2434 {
2435 	struct policydb *policydb;
2436 	struct sidtab *sidtab;
2437 	int rc = 0;
2438 	struct ocontext *c;
2439 
2440 	read_lock(&state->ss->policy_rwlock);
2441 
2442 	policydb = &state->ss->policydb;
2443 	sidtab = state->ss->sidtab;
2444 
2445 	c = policydb->ocontexts[OCON_NETIF];
2446 	while (c) {
2447 		if (strcmp(name, c->u.name) == 0)
2448 			break;
2449 		c = c->next;
2450 	}
2451 
2452 	if (c) {
2453 		if (!c->sid[0] || !c->sid[1]) {
2454 			rc = sidtab_context_to_sid(sidtab, &c->context[0],
2455 						   &c->sid[0]);
2456 			if (rc)
2457 				goto out;
2458 			rc = sidtab_context_to_sid(sidtab, &c->context[1],
2459 						   &c->sid[1]);
2460 			if (rc)
2461 				goto out;
2462 		}
2463 		*if_sid = c->sid[0];
2464 	} else
2465 		*if_sid = SECINITSID_NETIF;
2466 
2467 out:
2468 	read_unlock(&state->ss->policy_rwlock);
2469 	return rc;
2470 }
2471 
2472 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2473 {
2474 	int i, fail = 0;
2475 
2476 	for (i = 0; i < 4; i++)
2477 		if (addr[i] != (input[i] & mask[i])) {
2478 			fail = 1;
2479 			break;
2480 		}
2481 
2482 	return !fail;
2483 }
2484 
2485 /**
2486  * security_node_sid - Obtain the SID for a node (host).
2487  * @domain: communication domain aka address family
2488  * @addrp: address
2489  * @addrlen: address length in bytes
2490  * @out_sid: security identifier
2491  */
2492 int security_node_sid(struct selinux_state *state,
2493 		      u16 domain,
2494 		      void *addrp,
2495 		      u32 addrlen,
2496 		      u32 *out_sid)
2497 {
2498 	struct policydb *policydb;
2499 	struct sidtab *sidtab;
2500 	int rc;
2501 	struct ocontext *c;
2502 
2503 	read_lock(&state->ss->policy_rwlock);
2504 
2505 	policydb = &state->ss->policydb;
2506 	sidtab = state->ss->sidtab;
2507 
2508 	switch (domain) {
2509 	case AF_INET: {
2510 		u32 addr;
2511 
2512 		rc = -EINVAL;
2513 		if (addrlen != sizeof(u32))
2514 			goto out;
2515 
2516 		addr = *((u32 *)addrp);
2517 
2518 		c = policydb->ocontexts[OCON_NODE];
2519 		while (c) {
2520 			if (c->u.node.addr == (addr & c->u.node.mask))
2521 				break;
2522 			c = c->next;
2523 		}
2524 		break;
2525 	}
2526 
2527 	case AF_INET6:
2528 		rc = -EINVAL;
2529 		if (addrlen != sizeof(u64) * 2)
2530 			goto out;
2531 		c = policydb->ocontexts[OCON_NODE6];
2532 		while (c) {
2533 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2534 						c->u.node6.mask))
2535 				break;
2536 			c = c->next;
2537 		}
2538 		break;
2539 
2540 	default:
2541 		rc = 0;
2542 		*out_sid = SECINITSID_NODE;
2543 		goto out;
2544 	}
2545 
2546 	if (c) {
2547 		if (!c->sid[0]) {
2548 			rc = sidtab_context_to_sid(sidtab,
2549 						   &c->context[0],
2550 						   &c->sid[0]);
2551 			if (rc)
2552 				goto out;
2553 		}
2554 		*out_sid = c->sid[0];
2555 	} else {
2556 		*out_sid = SECINITSID_NODE;
2557 	}
2558 
2559 	rc = 0;
2560 out:
2561 	read_unlock(&state->ss->policy_rwlock);
2562 	return rc;
2563 }
2564 
2565 #define SIDS_NEL 25
2566 
2567 /**
2568  * security_get_user_sids - Obtain reachable SIDs for a user.
2569  * @fromsid: starting SID
2570  * @username: username
2571  * @sids: array of reachable SIDs for user
2572  * @nel: number of elements in @sids
2573  *
2574  * Generate the set of SIDs for legal security contexts
2575  * for a given user that can be reached by @fromsid.
2576  * Set *@sids to point to a dynamically allocated
2577  * array containing the set of SIDs.  Set *@nel to the
2578  * number of elements in the array.
2579  */
2580 
2581 int security_get_user_sids(struct selinux_state *state,
2582 			   u32 fromsid,
2583 			   char *username,
2584 			   u32 **sids,
2585 			   u32 *nel)
2586 {
2587 	struct policydb *policydb;
2588 	struct sidtab *sidtab;
2589 	struct context *fromcon, usercon;
2590 	u32 *mysids = NULL, *mysids2, sid;
2591 	u32 mynel = 0, maxnel = SIDS_NEL;
2592 	struct user_datum *user;
2593 	struct role_datum *role;
2594 	struct ebitmap_node *rnode, *tnode;
2595 	int rc = 0, i, j;
2596 
2597 	*sids = NULL;
2598 	*nel = 0;
2599 
2600 	if (!selinux_initialized(state))
2601 		goto out;
2602 
2603 	read_lock(&state->ss->policy_rwlock);
2604 
2605 	policydb = &state->ss->policydb;
2606 	sidtab = state->ss->sidtab;
2607 
2608 	context_init(&usercon);
2609 
2610 	rc = -EINVAL;
2611 	fromcon = sidtab_search(sidtab, fromsid);
2612 	if (!fromcon)
2613 		goto out_unlock;
2614 
2615 	rc = -EINVAL;
2616 	user = symtab_search(&policydb->p_users, username);
2617 	if (!user)
2618 		goto out_unlock;
2619 
2620 	usercon.user = user->value;
2621 
2622 	rc = -ENOMEM;
2623 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2624 	if (!mysids)
2625 		goto out_unlock;
2626 
2627 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2628 		role = policydb->role_val_to_struct[i];
2629 		usercon.role = i + 1;
2630 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2631 			usercon.type = j + 1;
2632 
2633 			if (mls_setup_user_range(policydb, fromcon, user,
2634 						 &usercon))
2635 				continue;
2636 
2637 			rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2638 			if (rc)
2639 				goto out_unlock;
2640 			if (mynel < maxnel) {
2641 				mysids[mynel++] = sid;
2642 			} else {
2643 				rc = -ENOMEM;
2644 				maxnel += SIDS_NEL;
2645 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2646 				if (!mysids2)
2647 					goto out_unlock;
2648 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2649 				kfree(mysids);
2650 				mysids = mysids2;
2651 				mysids[mynel++] = sid;
2652 			}
2653 		}
2654 	}
2655 	rc = 0;
2656 out_unlock:
2657 	read_unlock(&state->ss->policy_rwlock);
2658 	if (rc || !mynel) {
2659 		kfree(mysids);
2660 		goto out;
2661 	}
2662 
2663 	rc = -ENOMEM;
2664 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2665 	if (!mysids2) {
2666 		kfree(mysids);
2667 		goto out;
2668 	}
2669 	for (i = 0, j = 0; i < mynel; i++) {
2670 		struct av_decision dummy_avd;
2671 		rc = avc_has_perm_noaudit(state,
2672 					  fromsid, mysids[i],
2673 					  SECCLASS_PROCESS, /* kernel value */
2674 					  PROCESS__TRANSITION, AVC_STRICT,
2675 					  &dummy_avd);
2676 		if (!rc)
2677 			mysids2[j++] = mysids[i];
2678 		cond_resched();
2679 	}
2680 	rc = 0;
2681 	kfree(mysids);
2682 	*sids = mysids2;
2683 	*nel = j;
2684 out:
2685 	return rc;
2686 }
2687 
2688 /**
2689  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2690  * @fstype: filesystem type
2691  * @path: path from root of mount
2692  * @sclass: file security class
2693  * @sid: SID for path
2694  *
2695  * Obtain a SID to use for a file in a filesystem that
2696  * cannot support xattr or use a fixed labeling behavior like
2697  * transition SIDs or task SIDs.
2698  *
2699  * The caller must acquire the policy_rwlock before calling this function.
2700  */
2701 static inline int __security_genfs_sid(struct selinux_state *state,
2702 				       const char *fstype,
2703 				       char *path,
2704 				       u16 orig_sclass,
2705 				       u32 *sid)
2706 {
2707 	struct policydb *policydb = &state->ss->policydb;
2708 	struct sidtab *sidtab = state->ss->sidtab;
2709 	int len;
2710 	u16 sclass;
2711 	struct genfs *genfs;
2712 	struct ocontext *c;
2713 	int rc, cmp = 0;
2714 
2715 	while (path[0] == '/' && path[1] == '/')
2716 		path++;
2717 
2718 	sclass = unmap_class(&state->ss->map, orig_sclass);
2719 	*sid = SECINITSID_UNLABELED;
2720 
2721 	for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2722 		cmp = strcmp(fstype, genfs->fstype);
2723 		if (cmp <= 0)
2724 			break;
2725 	}
2726 
2727 	rc = -ENOENT;
2728 	if (!genfs || cmp)
2729 		goto out;
2730 
2731 	for (c = genfs->head; c; c = c->next) {
2732 		len = strlen(c->u.name);
2733 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2734 		    (strncmp(c->u.name, path, len) == 0))
2735 			break;
2736 	}
2737 
2738 	rc = -ENOENT;
2739 	if (!c)
2740 		goto out;
2741 
2742 	if (!c->sid[0]) {
2743 		rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
2744 		if (rc)
2745 			goto out;
2746 	}
2747 
2748 	*sid = c->sid[0];
2749 	rc = 0;
2750 out:
2751 	return rc;
2752 }
2753 
2754 /**
2755  * security_genfs_sid - Obtain a SID for a file in a filesystem
2756  * @fstype: filesystem type
2757  * @path: path from root of mount
2758  * @sclass: file security class
2759  * @sid: SID for path
2760  *
2761  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2762  * it afterward.
2763  */
2764 int security_genfs_sid(struct selinux_state *state,
2765 		       const char *fstype,
2766 		       char *path,
2767 		       u16 orig_sclass,
2768 		       u32 *sid)
2769 {
2770 	int retval;
2771 
2772 	read_lock(&state->ss->policy_rwlock);
2773 	retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid);
2774 	read_unlock(&state->ss->policy_rwlock);
2775 	return retval;
2776 }
2777 
2778 /**
2779  * security_fs_use - Determine how to handle labeling for a filesystem.
2780  * @sb: superblock in question
2781  */
2782 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2783 {
2784 	struct policydb *policydb;
2785 	struct sidtab *sidtab;
2786 	int rc = 0;
2787 	struct ocontext *c;
2788 	struct superblock_security_struct *sbsec = sb->s_security;
2789 	const char *fstype = sb->s_type->name;
2790 
2791 	read_lock(&state->ss->policy_rwlock);
2792 
2793 	policydb = &state->ss->policydb;
2794 	sidtab = state->ss->sidtab;
2795 
2796 	c = policydb->ocontexts[OCON_FSUSE];
2797 	while (c) {
2798 		if (strcmp(fstype, c->u.name) == 0)
2799 			break;
2800 		c = c->next;
2801 	}
2802 
2803 	if (c) {
2804 		sbsec->behavior = c->v.behavior;
2805 		if (!c->sid[0]) {
2806 			rc = sidtab_context_to_sid(sidtab, &c->context[0],
2807 						   &c->sid[0]);
2808 			if (rc)
2809 				goto out;
2810 		}
2811 		sbsec->sid = c->sid[0];
2812 	} else {
2813 		rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR,
2814 					  &sbsec->sid);
2815 		if (rc) {
2816 			sbsec->behavior = SECURITY_FS_USE_NONE;
2817 			rc = 0;
2818 		} else {
2819 			sbsec->behavior = SECURITY_FS_USE_GENFS;
2820 		}
2821 	}
2822 
2823 out:
2824 	read_unlock(&state->ss->policy_rwlock);
2825 	return rc;
2826 }
2827 
2828 int security_get_bools(struct selinux_state *state,
2829 		       u32 *len, char ***names, int **values)
2830 {
2831 	struct policydb *policydb;
2832 	u32 i;
2833 	int rc;
2834 
2835 	if (!selinux_initialized(state)) {
2836 		*len = 0;
2837 		*names = NULL;
2838 		*values = NULL;
2839 		return 0;
2840 	}
2841 
2842 	read_lock(&state->ss->policy_rwlock);
2843 
2844 	policydb = &state->ss->policydb;
2845 
2846 	*names = NULL;
2847 	*values = NULL;
2848 
2849 	rc = 0;
2850 	*len = policydb->p_bools.nprim;
2851 	if (!*len)
2852 		goto out;
2853 
2854 	rc = -ENOMEM;
2855 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2856 	if (!*names)
2857 		goto err;
2858 
2859 	rc = -ENOMEM;
2860 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2861 	if (!*values)
2862 		goto err;
2863 
2864 	for (i = 0; i < *len; i++) {
2865 		(*values)[i] = policydb->bool_val_to_struct[i]->state;
2866 
2867 		rc = -ENOMEM;
2868 		(*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
2869 				      GFP_ATOMIC);
2870 		if (!(*names)[i])
2871 			goto err;
2872 	}
2873 	rc = 0;
2874 out:
2875 	read_unlock(&state->ss->policy_rwlock);
2876 	return rc;
2877 err:
2878 	if (*names) {
2879 		for (i = 0; i < *len; i++)
2880 			kfree((*names)[i]);
2881 		kfree(*names);
2882 	}
2883 	kfree(*values);
2884 	*len = 0;
2885 	*names = NULL;
2886 	*values = NULL;
2887 	goto out;
2888 }
2889 
2890 
2891 int security_set_bools(struct selinux_state *state, u32 len, int *values)
2892 {
2893 	struct policydb *policydb;
2894 	int rc;
2895 	u32 i, lenp, seqno = 0;
2896 
2897 	write_lock_irq(&state->ss->policy_rwlock);
2898 
2899 	policydb = &state->ss->policydb;
2900 
2901 	rc = -EFAULT;
2902 	lenp = policydb->p_bools.nprim;
2903 	if (len != lenp)
2904 		goto out;
2905 
2906 	for (i = 0; i < len; i++) {
2907 		if (!!values[i] != policydb->bool_val_to_struct[i]->state) {
2908 			audit_log(audit_context(), GFP_ATOMIC,
2909 				AUDIT_MAC_CONFIG_CHANGE,
2910 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2911 				sym_name(policydb, SYM_BOOLS, i),
2912 				!!values[i],
2913 				policydb->bool_val_to_struct[i]->state,
2914 				from_kuid(&init_user_ns, audit_get_loginuid(current)),
2915 				audit_get_sessionid(current));
2916 		}
2917 		if (values[i])
2918 			policydb->bool_val_to_struct[i]->state = 1;
2919 		else
2920 			policydb->bool_val_to_struct[i]->state = 0;
2921 	}
2922 
2923 	evaluate_cond_nodes(policydb);
2924 
2925 	seqno = ++state->ss->latest_granting;
2926 	rc = 0;
2927 out:
2928 	write_unlock_irq(&state->ss->policy_rwlock);
2929 	if (!rc) {
2930 		avc_ss_reset(state->avc, seqno);
2931 		selnl_notify_policyload(seqno);
2932 		selinux_status_update_policyload(state, seqno);
2933 		selinux_xfrm_notify_policyload();
2934 	}
2935 	return rc;
2936 }
2937 
2938 int security_get_bool_value(struct selinux_state *state,
2939 			    u32 index)
2940 {
2941 	struct policydb *policydb;
2942 	int rc;
2943 	u32 len;
2944 
2945 	read_lock(&state->ss->policy_rwlock);
2946 
2947 	policydb = &state->ss->policydb;
2948 
2949 	rc = -EFAULT;
2950 	len = policydb->p_bools.nprim;
2951 	if (index >= len)
2952 		goto out;
2953 
2954 	rc = policydb->bool_val_to_struct[index]->state;
2955 out:
2956 	read_unlock(&state->ss->policy_rwlock);
2957 	return rc;
2958 }
2959 
2960 static int security_preserve_bools(struct selinux_state *state,
2961 				   struct policydb *policydb)
2962 {
2963 	int rc, *bvalues = NULL;
2964 	char **bnames = NULL;
2965 	struct cond_bool_datum *booldatum;
2966 	u32 i, nbools = 0;
2967 
2968 	rc = security_get_bools(state, &nbools, &bnames, &bvalues);
2969 	if (rc)
2970 		goto out;
2971 	for (i = 0; i < nbools; i++) {
2972 		booldatum = symtab_search(&policydb->p_bools, bnames[i]);
2973 		if (booldatum)
2974 			booldatum->state = bvalues[i];
2975 	}
2976 	evaluate_cond_nodes(policydb);
2977 
2978 out:
2979 	if (bnames) {
2980 		for (i = 0; i < nbools; i++)
2981 			kfree(bnames[i]);
2982 	}
2983 	kfree(bnames);
2984 	kfree(bvalues);
2985 	return rc;
2986 }
2987 
2988 /*
2989  * security_sid_mls_copy() - computes a new sid based on the given
2990  * sid and the mls portion of mls_sid.
2991  */
2992 int security_sid_mls_copy(struct selinux_state *state,
2993 			  u32 sid, u32 mls_sid, u32 *new_sid)
2994 {
2995 	struct policydb *policydb = &state->ss->policydb;
2996 	struct sidtab *sidtab = state->ss->sidtab;
2997 	struct context *context1;
2998 	struct context *context2;
2999 	struct context newcon;
3000 	char *s;
3001 	u32 len;
3002 	int rc;
3003 
3004 	rc = 0;
3005 	if (!selinux_initialized(state) || !policydb->mls_enabled) {
3006 		*new_sid = sid;
3007 		goto out;
3008 	}
3009 
3010 	context_init(&newcon);
3011 
3012 	read_lock(&state->ss->policy_rwlock);
3013 
3014 	rc = -EINVAL;
3015 	context1 = sidtab_search(sidtab, sid);
3016 	if (!context1) {
3017 		pr_err("SELinux: %s:  unrecognized SID %d\n",
3018 			__func__, sid);
3019 		goto out_unlock;
3020 	}
3021 
3022 	rc = -EINVAL;
3023 	context2 = sidtab_search(sidtab, mls_sid);
3024 	if (!context2) {
3025 		pr_err("SELinux: %s:  unrecognized SID %d\n",
3026 			__func__, mls_sid);
3027 		goto out_unlock;
3028 	}
3029 
3030 	newcon.user = context1->user;
3031 	newcon.role = context1->role;
3032 	newcon.type = context1->type;
3033 	rc = mls_context_cpy(&newcon, context2);
3034 	if (rc)
3035 		goto out_unlock;
3036 
3037 	/* Check the validity of the new context. */
3038 	if (!policydb_context_isvalid(policydb, &newcon)) {
3039 		rc = convert_context_handle_invalid_context(state, &newcon);
3040 		if (rc) {
3041 			if (!context_struct_to_string(policydb, &newcon, &s,
3042 						      &len)) {
3043 				struct audit_buffer *ab;
3044 
3045 				ab = audit_log_start(audit_context(),
3046 						     GFP_ATOMIC,
3047 						     AUDIT_SELINUX_ERR);
3048 				audit_log_format(ab,
3049 						 "op=security_sid_mls_copy invalid_context=");
3050 				/* don't record NUL with untrusted strings */
3051 				audit_log_n_untrustedstring(ab, s, len - 1);
3052 				audit_log_end(ab);
3053 				kfree(s);
3054 			}
3055 			goto out_unlock;
3056 		}
3057 	}
3058 	rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3059 out_unlock:
3060 	read_unlock(&state->ss->policy_rwlock);
3061 	context_destroy(&newcon);
3062 out:
3063 	return rc;
3064 }
3065 
3066 /**
3067  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3068  * @nlbl_sid: NetLabel SID
3069  * @nlbl_type: NetLabel labeling protocol type
3070  * @xfrm_sid: XFRM SID
3071  *
3072  * Description:
3073  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3074  * resolved into a single SID it is returned via @peer_sid and the function
3075  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3076  * returns a negative value.  A table summarizing the behavior is below:
3077  *
3078  *                                 | function return |      @sid
3079  *   ------------------------------+-----------------+-----------------
3080  *   no peer labels                |        0        |    SECSID_NULL
3081  *   single peer label             |        0        |    <peer_label>
3082  *   multiple, consistent labels   |        0        |    <peer_label>
3083  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3084  *
3085  */
3086 int security_net_peersid_resolve(struct selinux_state *state,
3087 				 u32 nlbl_sid, u32 nlbl_type,
3088 				 u32 xfrm_sid,
3089 				 u32 *peer_sid)
3090 {
3091 	struct policydb *policydb = &state->ss->policydb;
3092 	struct sidtab *sidtab = state->ss->sidtab;
3093 	int rc;
3094 	struct context *nlbl_ctx;
3095 	struct context *xfrm_ctx;
3096 
3097 	*peer_sid = SECSID_NULL;
3098 
3099 	/* handle the common (which also happens to be the set of easy) cases
3100 	 * right away, these two if statements catch everything involving a
3101 	 * single or absent peer SID/label */
3102 	if (xfrm_sid == SECSID_NULL) {
3103 		*peer_sid = nlbl_sid;
3104 		return 0;
3105 	}
3106 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3107 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3108 	 * is present */
3109 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3110 		*peer_sid = xfrm_sid;
3111 		return 0;
3112 	}
3113 
3114 	/*
3115 	 * We don't need to check initialized here since the only way both
3116 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3117 	 * security server was initialized and state->initialized was true.
3118 	 */
3119 	if (!policydb->mls_enabled)
3120 		return 0;
3121 
3122 	read_lock(&state->ss->policy_rwlock);
3123 
3124 	rc = -EINVAL;
3125 	nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3126 	if (!nlbl_ctx) {
3127 		pr_err("SELinux: %s:  unrecognized SID %d\n",
3128 		       __func__, nlbl_sid);
3129 		goto out;
3130 	}
3131 	rc = -EINVAL;
3132 	xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3133 	if (!xfrm_ctx) {
3134 		pr_err("SELinux: %s:  unrecognized SID %d\n",
3135 		       __func__, xfrm_sid);
3136 		goto out;
3137 	}
3138 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3139 	if (rc)
3140 		goto out;
3141 
3142 	/* at present NetLabel SIDs/labels really only carry MLS
3143 	 * information so if the MLS portion of the NetLabel SID
3144 	 * matches the MLS portion of the labeled XFRM SID/label
3145 	 * then pass along the XFRM SID as it is the most
3146 	 * expressive */
3147 	*peer_sid = xfrm_sid;
3148 out:
3149 	read_unlock(&state->ss->policy_rwlock);
3150 	return rc;
3151 }
3152 
3153 static int get_classes_callback(void *k, void *d, void *args)
3154 {
3155 	struct class_datum *datum = d;
3156 	char *name = k, **classes = args;
3157 	int value = datum->value - 1;
3158 
3159 	classes[value] = kstrdup(name, GFP_ATOMIC);
3160 	if (!classes[value])
3161 		return -ENOMEM;
3162 
3163 	return 0;
3164 }
3165 
3166 int security_get_classes(struct selinux_state *state,
3167 			 char ***classes, int *nclasses)
3168 {
3169 	struct policydb *policydb = &state->ss->policydb;
3170 	int rc;
3171 
3172 	if (!selinux_initialized(state)) {
3173 		*nclasses = 0;
3174 		*classes = NULL;
3175 		return 0;
3176 	}
3177 
3178 	read_lock(&state->ss->policy_rwlock);
3179 
3180 	rc = -ENOMEM;
3181 	*nclasses = policydb->p_classes.nprim;
3182 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3183 	if (!*classes)
3184 		goto out;
3185 
3186 	rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3187 			 *classes);
3188 	if (rc) {
3189 		int i;
3190 		for (i = 0; i < *nclasses; i++)
3191 			kfree((*classes)[i]);
3192 		kfree(*classes);
3193 	}
3194 
3195 out:
3196 	read_unlock(&state->ss->policy_rwlock);
3197 	return rc;
3198 }
3199 
3200 static int get_permissions_callback(void *k, void *d, void *args)
3201 {
3202 	struct perm_datum *datum = d;
3203 	char *name = k, **perms = args;
3204 	int value = datum->value - 1;
3205 
3206 	perms[value] = kstrdup(name, GFP_ATOMIC);
3207 	if (!perms[value])
3208 		return -ENOMEM;
3209 
3210 	return 0;
3211 }
3212 
3213 int security_get_permissions(struct selinux_state *state,
3214 			     char *class, char ***perms, int *nperms)
3215 {
3216 	struct policydb *policydb = &state->ss->policydb;
3217 	int rc, i;
3218 	struct class_datum *match;
3219 
3220 	read_lock(&state->ss->policy_rwlock);
3221 
3222 	rc = -EINVAL;
3223 	match = symtab_search(&policydb->p_classes, class);
3224 	if (!match) {
3225 		pr_err("SELinux: %s:  unrecognized class %s\n",
3226 			__func__, class);
3227 		goto out;
3228 	}
3229 
3230 	rc = -ENOMEM;
3231 	*nperms = match->permissions.nprim;
3232 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3233 	if (!*perms)
3234 		goto out;
3235 
3236 	if (match->comdatum) {
3237 		rc = hashtab_map(&match->comdatum->permissions.table,
3238 				 get_permissions_callback, *perms);
3239 		if (rc)
3240 			goto err;
3241 	}
3242 
3243 	rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3244 			 *perms);
3245 	if (rc)
3246 		goto err;
3247 
3248 out:
3249 	read_unlock(&state->ss->policy_rwlock);
3250 	return rc;
3251 
3252 err:
3253 	read_unlock(&state->ss->policy_rwlock);
3254 	for (i = 0; i < *nperms; i++)
3255 		kfree((*perms)[i]);
3256 	kfree(*perms);
3257 	return rc;
3258 }
3259 
3260 int security_get_reject_unknown(struct selinux_state *state)
3261 {
3262 	return state->ss->policydb.reject_unknown;
3263 }
3264 
3265 int security_get_allow_unknown(struct selinux_state *state)
3266 {
3267 	return state->ss->policydb.allow_unknown;
3268 }
3269 
3270 /**
3271  * security_policycap_supported - Check for a specific policy capability
3272  * @req_cap: capability
3273  *
3274  * Description:
3275  * This function queries the currently loaded policy to see if it supports the
3276  * capability specified by @req_cap.  Returns true (1) if the capability is
3277  * supported, false (0) if it isn't supported.
3278  *
3279  */
3280 int security_policycap_supported(struct selinux_state *state,
3281 				 unsigned int req_cap)
3282 {
3283 	struct policydb *policydb = &state->ss->policydb;
3284 	int rc;
3285 
3286 	read_lock(&state->ss->policy_rwlock);
3287 	rc = ebitmap_get_bit(&policydb->policycaps, req_cap);
3288 	read_unlock(&state->ss->policy_rwlock);
3289 
3290 	return rc;
3291 }
3292 
3293 struct selinux_audit_rule {
3294 	u32 au_seqno;
3295 	struct context au_ctxt;
3296 };
3297 
3298 void selinux_audit_rule_free(void *vrule)
3299 {
3300 	struct selinux_audit_rule *rule = vrule;
3301 
3302 	if (rule) {
3303 		context_destroy(&rule->au_ctxt);
3304 		kfree(rule);
3305 	}
3306 }
3307 
3308 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3309 {
3310 	struct selinux_state *state = &selinux_state;
3311 	struct policydb *policydb = &state->ss->policydb;
3312 	struct selinux_audit_rule *tmprule;
3313 	struct role_datum *roledatum;
3314 	struct type_datum *typedatum;
3315 	struct user_datum *userdatum;
3316 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3317 	int rc = 0;
3318 
3319 	*rule = NULL;
3320 
3321 	if (!selinux_initialized(state))
3322 		return -EOPNOTSUPP;
3323 
3324 	switch (field) {
3325 	case AUDIT_SUBJ_USER:
3326 	case AUDIT_SUBJ_ROLE:
3327 	case AUDIT_SUBJ_TYPE:
3328 	case AUDIT_OBJ_USER:
3329 	case AUDIT_OBJ_ROLE:
3330 	case AUDIT_OBJ_TYPE:
3331 		/* only 'equals' and 'not equals' fit user, role, and type */
3332 		if (op != Audit_equal && op != Audit_not_equal)
3333 			return -EINVAL;
3334 		break;
3335 	case AUDIT_SUBJ_SEN:
3336 	case AUDIT_SUBJ_CLR:
3337 	case AUDIT_OBJ_LEV_LOW:
3338 	case AUDIT_OBJ_LEV_HIGH:
3339 		/* we do not allow a range, indicated by the presence of '-' */
3340 		if (strchr(rulestr, '-'))
3341 			return -EINVAL;
3342 		break;
3343 	default:
3344 		/* only the above fields are valid */
3345 		return -EINVAL;
3346 	}
3347 
3348 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3349 	if (!tmprule)
3350 		return -ENOMEM;
3351 
3352 	context_init(&tmprule->au_ctxt);
3353 
3354 	read_lock(&state->ss->policy_rwlock);
3355 
3356 	tmprule->au_seqno = state->ss->latest_granting;
3357 
3358 	switch (field) {
3359 	case AUDIT_SUBJ_USER:
3360 	case AUDIT_OBJ_USER:
3361 		rc = -EINVAL;
3362 		userdatum = symtab_search(&policydb->p_users, rulestr);
3363 		if (!userdatum)
3364 			goto out;
3365 		tmprule->au_ctxt.user = userdatum->value;
3366 		break;
3367 	case AUDIT_SUBJ_ROLE:
3368 	case AUDIT_OBJ_ROLE:
3369 		rc = -EINVAL;
3370 		roledatum = symtab_search(&policydb->p_roles, rulestr);
3371 		if (!roledatum)
3372 			goto out;
3373 		tmprule->au_ctxt.role = roledatum->value;
3374 		break;
3375 	case AUDIT_SUBJ_TYPE:
3376 	case AUDIT_OBJ_TYPE:
3377 		rc = -EINVAL;
3378 		typedatum = symtab_search(&policydb->p_types, rulestr);
3379 		if (!typedatum)
3380 			goto out;
3381 		tmprule->au_ctxt.type = typedatum->value;
3382 		break;
3383 	case AUDIT_SUBJ_SEN:
3384 	case AUDIT_SUBJ_CLR:
3385 	case AUDIT_OBJ_LEV_LOW:
3386 	case AUDIT_OBJ_LEV_HIGH:
3387 		rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3388 				     GFP_ATOMIC);
3389 		if (rc)
3390 			goto out;
3391 		break;
3392 	}
3393 	rc = 0;
3394 out:
3395 	read_unlock(&state->ss->policy_rwlock);
3396 
3397 	if (rc) {
3398 		selinux_audit_rule_free(tmprule);
3399 		tmprule = NULL;
3400 	}
3401 
3402 	*rule = tmprule;
3403 
3404 	return rc;
3405 }
3406 
3407 /* Check to see if the rule contains any selinux fields */
3408 int selinux_audit_rule_known(struct audit_krule *rule)
3409 {
3410 	int i;
3411 
3412 	for (i = 0; i < rule->field_count; i++) {
3413 		struct audit_field *f = &rule->fields[i];
3414 		switch (f->type) {
3415 		case AUDIT_SUBJ_USER:
3416 		case AUDIT_SUBJ_ROLE:
3417 		case AUDIT_SUBJ_TYPE:
3418 		case AUDIT_SUBJ_SEN:
3419 		case AUDIT_SUBJ_CLR:
3420 		case AUDIT_OBJ_USER:
3421 		case AUDIT_OBJ_ROLE:
3422 		case AUDIT_OBJ_TYPE:
3423 		case AUDIT_OBJ_LEV_LOW:
3424 		case AUDIT_OBJ_LEV_HIGH:
3425 			return 1;
3426 		}
3427 	}
3428 
3429 	return 0;
3430 }
3431 
3432 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3433 {
3434 	struct selinux_state *state = &selinux_state;
3435 	struct context *ctxt;
3436 	struct mls_level *level;
3437 	struct selinux_audit_rule *rule = vrule;
3438 	int match = 0;
3439 
3440 	if (unlikely(!rule)) {
3441 		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3442 		return -ENOENT;
3443 	}
3444 
3445 	read_lock(&state->ss->policy_rwlock);
3446 
3447 	if (rule->au_seqno < state->ss->latest_granting) {
3448 		match = -ESTALE;
3449 		goto out;
3450 	}
3451 
3452 	ctxt = sidtab_search(state->ss->sidtab, sid);
3453 	if (unlikely(!ctxt)) {
3454 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3455 			  sid);
3456 		match = -ENOENT;
3457 		goto out;
3458 	}
3459 
3460 	/* a field/op pair that is not caught here will simply fall through
3461 	   without a match */
3462 	switch (field) {
3463 	case AUDIT_SUBJ_USER:
3464 	case AUDIT_OBJ_USER:
3465 		switch (op) {
3466 		case Audit_equal:
3467 			match = (ctxt->user == rule->au_ctxt.user);
3468 			break;
3469 		case Audit_not_equal:
3470 			match = (ctxt->user != rule->au_ctxt.user);
3471 			break;
3472 		}
3473 		break;
3474 	case AUDIT_SUBJ_ROLE:
3475 	case AUDIT_OBJ_ROLE:
3476 		switch (op) {
3477 		case Audit_equal:
3478 			match = (ctxt->role == rule->au_ctxt.role);
3479 			break;
3480 		case Audit_not_equal:
3481 			match = (ctxt->role != rule->au_ctxt.role);
3482 			break;
3483 		}
3484 		break;
3485 	case AUDIT_SUBJ_TYPE:
3486 	case AUDIT_OBJ_TYPE:
3487 		switch (op) {
3488 		case Audit_equal:
3489 			match = (ctxt->type == rule->au_ctxt.type);
3490 			break;
3491 		case Audit_not_equal:
3492 			match = (ctxt->type != rule->au_ctxt.type);
3493 			break;
3494 		}
3495 		break;
3496 	case AUDIT_SUBJ_SEN:
3497 	case AUDIT_SUBJ_CLR:
3498 	case AUDIT_OBJ_LEV_LOW:
3499 	case AUDIT_OBJ_LEV_HIGH:
3500 		level = ((field == AUDIT_SUBJ_SEN ||
3501 			  field == AUDIT_OBJ_LEV_LOW) ?
3502 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3503 		switch (op) {
3504 		case Audit_equal:
3505 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3506 					     level);
3507 			break;
3508 		case Audit_not_equal:
3509 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3510 					      level);
3511 			break;
3512 		case Audit_lt:
3513 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3514 					       level) &&
3515 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3516 					       level));
3517 			break;
3518 		case Audit_le:
3519 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3520 					      level);
3521 			break;
3522 		case Audit_gt:
3523 			match = (mls_level_dom(level,
3524 					      &rule->au_ctxt.range.level[0]) &&
3525 				 !mls_level_eq(level,
3526 					       &rule->au_ctxt.range.level[0]));
3527 			break;
3528 		case Audit_ge:
3529 			match = mls_level_dom(level,
3530 					      &rule->au_ctxt.range.level[0]);
3531 			break;
3532 		}
3533 	}
3534 
3535 out:
3536 	read_unlock(&state->ss->policy_rwlock);
3537 	return match;
3538 }
3539 
3540 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3541 
3542 static int aurule_avc_callback(u32 event)
3543 {
3544 	int err = 0;
3545 
3546 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3547 		err = aurule_callback();
3548 	return err;
3549 }
3550 
3551 static int __init aurule_init(void)
3552 {
3553 	int err;
3554 
3555 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3556 	if (err)
3557 		panic("avc_add_callback() failed, error %d\n", err);
3558 
3559 	return err;
3560 }
3561 __initcall(aurule_init);
3562 
3563 #ifdef CONFIG_NETLABEL
3564 /**
3565  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3566  * @secattr: the NetLabel packet security attributes
3567  * @sid: the SELinux SID
3568  *
3569  * Description:
3570  * Attempt to cache the context in @ctx, which was derived from the packet in
3571  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3572  * already been initialized.
3573  *
3574  */
3575 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3576 				      u32 sid)
3577 {
3578 	u32 *sid_cache;
3579 
3580 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3581 	if (sid_cache == NULL)
3582 		return;
3583 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3584 	if (secattr->cache == NULL) {
3585 		kfree(sid_cache);
3586 		return;
3587 	}
3588 
3589 	*sid_cache = sid;
3590 	secattr->cache->free = kfree;
3591 	secattr->cache->data = sid_cache;
3592 	secattr->flags |= NETLBL_SECATTR_CACHE;
3593 }
3594 
3595 /**
3596  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3597  * @secattr: the NetLabel packet security attributes
3598  * @sid: the SELinux SID
3599  *
3600  * Description:
3601  * Convert the given NetLabel security attributes in @secattr into a
3602  * SELinux SID.  If the @secattr field does not contain a full SELinux
3603  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3604  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3605  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3606  * conversion for future lookups.  Returns zero on success, negative values on
3607  * failure.
3608  *
3609  */
3610 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3611 				   struct netlbl_lsm_secattr *secattr,
3612 				   u32 *sid)
3613 {
3614 	struct policydb *policydb = &state->ss->policydb;
3615 	struct sidtab *sidtab = state->ss->sidtab;
3616 	int rc;
3617 	struct context *ctx;
3618 	struct context ctx_new;
3619 
3620 	if (!selinux_initialized(state)) {
3621 		*sid = SECSID_NULL;
3622 		return 0;
3623 	}
3624 
3625 	read_lock(&state->ss->policy_rwlock);
3626 
3627 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3628 		*sid = *(u32 *)secattr->cache->data;
3629 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3630 		*sid = secattr->attr.secid;
3631 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3632 		rc = -EIDRM;
3633 		ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3634 		if (ctx == NULL)
3635 			goto out;
3636 
3637 		context_init(&ctx_new);
3638 		ctx_new.user = ctx->user;
3639 		ctx_new.role = ctx->role;
3640 		ctx_new.type = ctx->type;
3641 		mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3642 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3643 			rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3644 			if (rc)
3645 				goto out;
3646 		}
3647 		rc = -EIDRM;
3648 		if (!mls_context_isvalid(policydb, &ctx_new))
3649 			goto out_free;
3650 
3651 		rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3652 		if (rc)
3653 			goto out_free;
3654 
3655 		security_netlbl_cache_add(secattr, *sid);
3656 
3657 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3658 	} else
3659 		*sid = SECSID_NULL;
3660 
3661 	read_unlock(&state->ss->policy_rwlock);
3662 	return 0;
3663 out_free:
3664 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3665 out:
3666 	read_unlock(&state->ss->policy_rwlock);
3667 	return rc;
3668 }
3669 
3670 /**
3671  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3672  * @sid: the SELinux SID
3673  * @secattr: the NetLabel packet security attributes
3674  *
3675  * Description:
3676  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3677  * Returns zero on success, negative values on failure.
3678  *
3679  */
3680 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3681 				   u32 sid, struct netlbl_lsm_secattr *secattr)
3682 {
3683 	struct policydb *policydb = &state->ss->policydb;
3684 	int rc;
3685 	struct context *ctx;
3686 
3687 	if (!selinux_initialized(state))
3688 		return 0;
3689 
3690 	read_lock(&state->ss->policy_rwlock);
3691 
3692 	rc = -ENOENT;
3693 	ctx = sidtab_search(state->ss->sidtab, sid);
3694 	if (ctx == NULL)
3695 		goto out;
3696 
3697 	rc = -ENOMEM;
3698 	secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3699 				  GFP_ATOMIC);
3700 	if (secattr->domain == NULL)
3701 		goto out;
3702 
3703 	secattr->attr.secid = sid;
3704 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3705 	mls_export_netlbl_lvl(policydb, ctx, secattr);
3706 	rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3707 out:
3708 	read_unlock(&state->ss->policy_rwlock);
3709 	return rc;
3710 }
3711 #endif /* CONFIG_NETLABEL */
3712 
3713 /**
3714  * security_read_policy - read the policy.
3715  * @data: binary policy data
3716  * @len: length of data in bytes
3717  *
3718  */
3719 int security_read_policy(struct selinux_state *state,
3720 			 void **data, size_t *len)
3721 {
3722 	struct policydb *policydb = &state->ss->policydb;
3723 	int rc;
3724 	struct policy_file fp;
3725 
3726 	if (!selinux_initialized(state))
3727 		return -EINVAL;
3728 
3729 	*len = security_policydb_len(state);
3730 
3731 	*data = vmalloc_user(*len);
3732 	if (!*data)
3733 		return -ENOMEM;
3734 
3735 	fp.data = *data;
3736 	fp.len = *len;
3737 
3738 	read_lock(&state->ss->policy_rwlock);
3739 	rc = policydb_write(policydb, &fp);
3740 	read_unlock(&state->ss->policy_rwlock);
3741 
3742 	if (rc)
3743 		return rc;
3744 
3745 	*len = (unsigned long)fp.data - (unsigned long)*data;
3746 	return 0;
3747 
3748 }
3749