xref: /openbmc/linux/security/selinux/ss/services.c (revision f3a8b664)
1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5  *	     James Morris <jmorris@redhat.com>
6  *
7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8  *
9  *	Support for enhanced MLS infrastructure.
10  *	Support for context based audit filters.
11  *
12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  *	Added conditional policy language extensions
15  *
16  * Updated: Hewlett-Packard <paul@paul-moore.com>
17  *
18  *      Added support for NetLabel
19  *      Added support for the policy capability bitmap
20  *
21  * Updated: Chad Sellers <csellers@tresys.com>
22  *
23  *  Added validation of kernel classes and permissions
24  *
25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26  *
27  *  Added support for bounds domain and audit messaged on masked permissions
28  *
29  * Updated: Guido Trentalancia <guido@trentalancia.com>
30  *
31  *  Added support for runtime switching of the policy type
32  *
33  * Copyright (C) 2008, 2009 NEC Corporation
34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38  *	This program is free software; you can redistribute it and/or modify
39  *	it under the terms of the GNU General Public License as published by
40  *	the Free Software Foundation, version 2.
41  */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56 
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72 
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76 
77 static DEFINE_RWLOCK(policy_rwlock);
78 
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82 
83 /*
84  * The largest sequence number that has been used when
85  * providing an access decision to the access vector cache.
86  * The sequence number only changes when a policy change
87  * occurs.
88  */
89 static u32 latest_granting;
90 
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 				    u32 *scontext_len);
94 
95 static void context_struct_compute_av(struct context *scontext,
96 					struct context *tcontext,
97 					u16 tclass,
98 					struct av_decision *avd,
99 					struct extended_perms *xperms);
100 
101 struct selinux_mapping {
102 	u16 value; /* policy value */
103 	unsigned num_perms;
104 	u32 perms[sizeof(u32) * 8];
105 };
106 
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109 
110 static int selinux_set_mapping(struct policydb *pol,
111 			       struct security_class_mapping *map,
112 			       struct selinux_mapping **out_map_p,
113 			       u16 *out_map_size)
114 {
115 	struct selinux_mapping *out_map = NULL;
116 	size_t size = sizeof(struct selinux_mapping);
117 	u16 i, j;
118 	unsigned k;
119 	bool print_unknown_handle = false;
120 
121 	/* Find number of classes in the input mapping */
122 	if (!map)
123 		return -EINVAL;
124 	i = 0;
125 	while (map[i].name)
126 		i++;
127 
128 	/* Allocate space for the class records, plus one for class zero */
129 	out_map = kcalloc(++i, size, GFP_ATOMIC);
130 	if (!out_map)
131 		return -ENOMEM;
132 
133 	/* Store the raw class and permission values */
134 	j = 0;
135 	while (map[j].name) {
136 		struct security_class_mapping *p_in = map + (j++);
137 		struct selinux_mapping *p_out = out_map + j;
138 
139 		/* An empty class string skips ahead */
140 		if (!strcmp(p_in->name, "")) {
141 			p_out->num_perms = 0;
142 			continue;
143 		}
144 
145 		p_out->value = string_to_security_class(pol, p_in->name);
146 		if (!p_out->value) {
147 			printk(KERN_INFO
148 			       "SELinux:  Class %s not defined in policy.\n",
149 			       p_in->name);
150 			if (pol->reject_unknown)
151 				goto err;
152 			p_out->num_perms = 0;
153 			print_unknown_handle = true;
154 			continue;
155 		}
156 
157 		k = 0;
158 		while (p_in->perms && p_in->perms[k]) {
159 			/* An empty permission string skips ahead */
160 			if (!*p_in->perms[k]) {
161 				k++;
162 				continue;
163 			}
164 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 							    p_in->perms[k]);
166 			if (!p_out->perms[k]) {
167 				printk(KERN_INFO
168 				       "SELinux:  Permission %s in class %s not defined in policy.\n",
169 				       p_in->perms[k], p_in->name);
170 				if (pol->reject_unknown)
171 					goto err;
172 				print_unknown_handle = true;
173 			}
174 
175 			k++;
176 		}
177 		p_out->num_perms = k;
178 	}
179 
180 	if (print_unknown_handle)
181 		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 		       pol->allow_unknown ? "allowed" : "denied");
183 
184 	*out_map_p = out_map;
185 	*out_map_size = i;
186 	return 0;
187 err:
188 	kfree(out_map);
189 	return -EINVAL;
190 }
191 
192 /*
193  * Get real, policy values from mapped values
194  */
195 
196 static u16 unmap_class(u16 tclass)
197 {
198 	if (tclass < current_mapping_size)
199 		return current_mapping[tclass].value;
200 
201 	return tclass;
202 }
203 
204 /*
205  * Get kernel value for class from its policy value
206  */
207 static u16 map_class(u16 pol_value)
208 {
209 	u16 i;
210 
211 	for (i = 1; i < current_mapping_size; i++) {
212 		if (current_mapping[i].value == pol_value)
213 			return i;
214 	}
215 
216 	return SECCLASS_NULL;
217 }
218 
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 			 int allow_unknown)
221 {
222 	if (tclass < current_mapping_size) {
223 		unsigned i, n = current_mapping[tclass].num_perms;
224 		u32 result;
225 
226 		for (i = 0, result = 0; i < n; i++) {
227 			if (avd->allowed & current_mapping[tclass].perms[i])
228 				result |= 1<<i;
229 			if (allow_unknown && !current_mapping[tclass].perms[i])
230 				result |= 1<<i;
231 		}
232 		avd->allowed = result;
233 
234 		for (i = 0, result = 0; i < n; i++)
235 			if (avd->auditallow & current_mapping[tclass].perms[i])
236 				result |= 1<<i;
237 		avd->auditallow = result;
238 
239 		for (i = 0, result = 0; i < n; i++) {
240 			if (avd->auditdeny & current_mapping[tclass].perms[i])
241 				result |= 1<<i;
242 			if (!allow_unknown && !current_mapping[tclass].perms[i])
243 				result |= 1<<i;
244 		}
245 		/*
246 		 * In case the kernel has a bug and requests a permission
247 		 * between num_perms and the maximum permission number, we
248 		 * should audit that denial
249 		 */
250 		for (; i < (sizeof(u32)*8); i++)
251 			result |= 1<<i;
252 		avd->auditdeny = result;
253 	}
254 }
255 
256 int security_mls_enabled(void)
257 {
258 	return policydb.mls_enabled;
259 }
260 
261 /*
262  * Return the boolean value of a constraint expression
263  * when it is applied to the specified source and target
264  * security contexts.
265  *
266  * xcontext is a special beast...  It is used by the validatetrans rules
267  * only.  For these rules, scontext is the context before the transition,
268  * tcontext is the context after the transition, and xcontext is the context
269  * of the process performing the transition.  All other callers of
270  * constraint_expr_eval should pass in NULL for xcontext.
271  */
272 static int constraint_expr_eval(struct context *scontext,
273 				struct context *tcontext,
274 				struct context *xcontext,
275 				struct constraint_expr *cexpr)
276 {
277 	u32 val1, val2;
278 	struct context *c;
279 	struct role_datum *r1, *r2;
280 	struct mls_level *l1, *l2;
281 	struct constraint_expr *e;
282 	int s[CEXPR_MAXDEPTH];
283 	int sp = -1;
284 
285 	for (e = cexpr; e; e = e->next) {
286 		switch (e->expr_type) {
287 		case CEXPR_NOT:
288 			BUG_ON(sp < 0);
289 			s[sp] = !s[sp];
290 			break;
291 		case CEXPR_AND:
292 			BUG_ON(sp < 1);
293 			sp--;
294 			s[sp] &= s[sp + 1];
295 			break;
296 		case CEXPR_OR:
297 			BUG_ON(sp < 1);
298 			sp--;
299 			s[sp] |= s[sp + 1];
300 			break;
301 		case CEXPR_ATTR:
302 			if (sp == (CEXPR_MAXDEPTH - 1))
303 				return 0;
304 			switch (e->attr) {
305 			case CEXPR_USER:
306 				val1 = scontext->user;
307 				val2 = tcontext->user;
308 				break;
309 			case CEXPR_TYPE:
310 				val1 = scontext->type;
311 				val2 = tcontext->type;
312 				break;
313 			case CEXPR_ROLE:
314 				val1 = scontext->role;
315 				val2 = tcontext->role;
316 				r1 = policydb.role_val_to_struct[val1 - 1];
317 				r2 = policydb.role_val_to_struct[val2 - 1];
318 				switch (e->op) {
319 				case CEXPR_DOM:
320 					s[++sp] = ebitmap_get_bit(&r1->dominates,
321 								  val2 - 1);
322 					continue;
323 				case CEXPR_DOMBY:
324 					s[++sp] = ebitmap_get_bit(&r2->dominates,
325 								  val1 - 1);
326 					continue;
327 				case CEXPR_INCOMP:
328 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 								    val2 - 1) &&
330 						   !ebitmap_get_bit(&r2->dominates,
331 								    val1 - 1));
332 					continue;
333 				default:
334 					break;
335 				}
336 				break;
337 			case CEXPR_L1L2:
338 				l1 = &(scontext->range.level[0]);
339 				l2 = &(tcontext->range.level[0]);
340 				goto mls_ops;
341 			case CEXPR_L1H2:
342 				l1 = &(scontext->range.level[0]);
343 				l2 = &(tcontext->range.level[1]);
344 				goto mls_ops;
345 			case CEXPR_H1L2:
346 				l1 = &(scontext->range.level[1]);
347 				l2 = &(tcontext->range.level[0]);
348 				goto mls_ops;
349 			case CEXPR_H1H2:
350 				l1 = &(scontext->range.level[1]);
351 				l2 = &(tcontext->range.level[1]);
352 				goto mls_ops;
353 			case CEXPR_L1H1:
354 				l1 = &(scontext->range.level[0]);
355 				l2 = &(scontext->range.level[1]);
356 				goto mls_ops;
357 			case CEXPR_L2H2:
358 				l1 = &(tcontext->range.level[0]);
359 				l2 = &(tcontext->range.level[1]);
360 				goto mls_ops;
361 mls_ops:
362 			switch (e->op) {
363 			case CEXPR_EQ:
364 				s[++sp] = mls_level_eq(l1, l2);
365 				continue;
366 			case CEXPR_NEQ:
367 				s[++sp] = !mls_level_eq(l1, l2);
368 				continue;
369 			case CEXPR_DOM:
370 				s[++sp] = mls_level_dom(l1, l2);
371 				continue;
372 			case CEXPR_DOMBY:
373 				s[++sp] = mls_level_dom(l2, l1);
374 				continue;
375 			case CEXPR_INCOMP:
376 				s[++sp] = mls_level_incomp(l2, l1);
377 				continue;
378 			default:
379 				BUG();
380 				return 0;
381 			}
382 			break;
383 			default:
384 				BUG();
385 				return 0;
386 			}
387 
388 			switch (e->op) {
389 			case CEXPR_EQ:
390 				s[++sp] = (val1 == val2);
391 				break;
392 			case CEXPR_NEQ:
393 				s[++sp] = (val1 != val2);
394 				break;
395 			default:
396 				BUG();
397 				return 0;
398 			}
399 			break;
400 		case CEXPR_NAMES:
401 			if (sp == (CEXPR_MAXDEPTH-1))
402 				return 0;
403 			c = scontext;
404 			if (e->attr & CEXPR_TARGET)
405 				c = tcontext;
406 			else if (e->attr & CEXPR_XTARGET) {
407 				c = xcontext;
408 				if (!c) {
409 					BUG();
410 					return 0;
411 				}
412 			}
413 			if (e->attr & CEXPR_USER)
414 				val1 = c->user;
415 			else if (e->attr & CEXPR_ROLE)
416 				val1 = c->role;
417 			else if (e->attr & CEXPR_TYPE)
418 				val1 = c->type;
419 			else {
420 				BUG();
421 				return 0;
422 			}
423 
424 			switch (e->op) {
425 			case CEXPR_EQ:
426 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 				break;
428 			case CEXPR_NEQ:
429 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 				break;
431 			default:
432 				BUG();
433 				return 0;
434 			}
435 			break;
436 		default:
437 			BUG();
438 			return 0;
439 		}
440 	}
441 
442 	BUG_ON(sp != 0);
443 	return s[0];
444 }
445 
446 /*
447  * security_dump_masked_av - dumps masked permissions during
448  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449  */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 	struct perm_datum *pdatum = d;
453 	char **permission_names = args;
454 
455 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456 
457 	permission_names[pdatum->value - 1] = (char *)k;
458 
459 	return 0;
460 }
461 
462 static void security_dump_masked_av(struct context *scontext,
463 				    struct context *tcontext,
464 				    u16 tclass,
465 				    u32 permissions,
466 				    const char *reason)
467 {
468 	struct common_datum *common_dat;
469 	struct class_datum *tclass_dat;
470 	struct audit_buffer *ab;
471 	char *tclass_name;
472 	char *scontext_name = NULL;
473 	char *tcontext_name = NULL;
474 	char *permission_names[32];
475 	int index;
476 	u32 length;
477 	bool need_comma = false;
478 
479 	if (!permissions)
480 		return;
481 
482 	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 	tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 	common_dat = tclass_dat->comdatum;
485 
486 	/* init permission_names */
487 	if (common_dat &&
488 	    hashtab_map(common_dat->permissions.table,
489 			dump_masked_av_helper, permission_names) < 0)
490 		goto out;
491 
492 	if (hashtab_map(tclass_dat->permissions.table,
493 			dump_masked_av_helper, permission_names) < 0)
494 		goto out;
495 
496 	/* get scontext/tcontext in text form */
497 	if (context_struct_to_string(scontext,
498 				     &scontext_name, &length) < 0)
499 		goto out;
500 
501 	if (context_struct_to_string(tcontext,
502 				     &tcontext_name, &length) < 0)
503 		goto out;
504 
505 	/* audit a message */
506 	ab = audit_log_start(current->audit_context,
507 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 	if (!ab)
509 		goto out;
510 
511 	audit_log_format(ab, "op=security_compute_av reason=%s "
512 			 "scontext=%s tcontext=%s tclass=%s perms=",
513 			 reason, scontext_name, tcontext_name, tclass_name);
514 
515 	for (index = 0; index < 32; index++) {
516 		u32 mask = (1 << index);
517 
518 		if ((mask & permissions) == 0)
519 			continue;
520 
521 		audit_log_format(ab, "%s%s",
522 				 need_comma ? "," : "",
523 				 permission_names[index]
524 				 ? permission_names[index] : "????");
525 		need_comma = true;
526 	}
527 	audit_log_end(ab);
528 out:
529 	/* release scontext/tcontext */
530 	kfree(tcontext_name);
531 	kfree(scontext_name);
532 
533 	return;
534 }
535 
536 /*
537  * security_boundary_permission - drops violated permissions
538  * on boundary constraint.
539  */
540 static void type_attribute_bounds_av(struct context *scontext,
541 				     struct context *tcontext,
542 				     u16 tclass,
543 				     struct av_decision *avd)
544 {
545 	struct context lo_scontext;
546 	struct context lo_tcontext, *tcontextp = tcontext;
547 	struct av_decision lo_avd;
548 	struct type_datum *source;
549 	struct type_datum *target;
550 	u32 masked = 0;
551 
552 	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 				    scontext->type - 1);
554 	BUG_ON(!source);
555 
556 	if (!source->bounds)
557 		return;
558 
559 	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
560 				    tcontext->type - 1);
561 	BUG_ON(!target);
562 
563 	memset(&lo_avd, 0, sizeof(lo_avd));
564 
565 	memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
566 	lo_scontext.type = source->bounds;
567 
568 	if (target->bounds) {
569 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
570 		lo_tcontext.type = target->bounds;
571 		tcontextp = &lo_tcontext;
572 	}
573 
574 	context_struct_compute_av(&lo_scontext,
575 				  tcontextp,
576 				  tclass,
577 				  &lo_avd,
578 				  NULL);
579 
580 	masked = ~lo_avd.allowed & avd->allowed;
581 
582 	if (likely(!masked))
583 		return;		/* no masked permission */
584 
585 	/* mask violated permissions */
586 	avd->allowed &= ~masked;
587 
588 	/* audit masked permissions */
589 	security_dump_masked_av(scontext, tcontext,
590 				tclass, masked, "bounds");
591 }
592 
593 /*
594  * flag which drivers have permissions
595  * only looking for ioctl based extended permssions
596  */
597 void services_compute_xperms_drivers(
598 		struct extended_perms *xperms,
599 		struct avtab_node *node)
600 {
601 	unsigned int i;
602 
603 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
604 		/* if one or more driver has all permissions allowed */
605 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
606 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
607 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
608 		/* if allowing permissions within a driver */
609 		security_xperm_set(xperms->drivers.p,
610 					node->datum.u.xperms->driver);
611 	}
612 
613 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
614 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
615 		xperms->len = 1;
616 }
617 
618 /*
619  * Compute access vectors and extended permissions based on a context
620  * structure pair for the permissions in a particular class.
621  */
622 static void context_struct_compute_av(struct context *scontext,
623 					struct context *tcontext,
624 					u16 tclass,
625 					struct av_decision *avd,
626 					struct extended_perms *xperms)
627 {
628 	struct constraint_node *constraint;
629 	struct role_allow *ra;
630 	struct avtab_key avkey;
631 	struct avtab_node *node;
632 	struct class_datum *tclass_datum;
633 	struct ebitmap *sattr, *tattr;
634 	struct ebitmap_node *snode, *tnode;
635 	unsigned int i, j;
636 
637 	avd->allowed = 0;
638 	avd->auditallow = 0;
639 	avd->auditdeny = 0xffffffff;
640 	if (xperms) {
641 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
642 		xperms->len = 0;
643 	}
644 
645 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
646 		if (printk_ratelimit())
647 			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
648 		return;
649 	}
650 
651 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
652 
653 	/*
654 	 * If a specific type enforcement rule was defined for
655 	 * this permission check, then use it.
656 	 */
657 	avkey.target_class = tclass;
658 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
659 	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
660 	BUG_ON(!sattr);
661 	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
662 	BUG_ON(!tattr);
663 	ebitmap_for_each_positive_bit(sattr, snode, i) {
664 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
665 			avkey.source_type = i + 1;
666 			avkey.target_type = j + 1;
667 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
668 			     node;
669 			     node = avtab_search_node_next(node, avkey.specified)) {
670 				if (node->key.specified == AVTAB_ALLOWED)
671 					avd->allowed |= node->datum.u.data;
672 				else if (node->key.specified == AVTAB_AUDITALLOW)
673 					avd->auditallow |= node->datum.u.data;
674 				else if (node->key.specified == AVTAB_AUDITDENY)
675 					avd->auditdeny &= node->datum.u.data;
676 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
677 					services_compute_xperms_drivers(xperms, node);
678 			}
679 
680 			/* Check conditional av table for additional permissions */
681 			cond_compute_av(&policydb.te_cond_avtab, &avkey,
682 					avd, xperms);
683 
684 		}
685 	}
686 
687 	/*
688 	 * Remove any permissions prohibited by a constraint (this includes
689 	 * the MLS policy).
690 	 */
691 	constraint = tclass_datum->constraints;
692 	while (constraint) {
693 		if ((constraint->permissions & (avd->allowed)) &&
694 		    !constraint_expr_eval(scontext, tcontext, NULL,
695 					  constraint->expr)) {
696 			avd->allowed &= ~(constraint->permissions);
697 		}
698 		constraint = constraint->next;
699 	}
700 
701 	/*
702 	 * If checking process transition permission and the
703 	 * role is changing, then check the (current_role, new_role)
704 	 * pair.
705 	 */
706 	if (tclass == policydb.process_class &&
707 	    (avd->allowed & policydb.process_trans_perms) &&
708 	    scontext->role != tcontext->role) {
709 		for (ra = policydb.role_allow; ra; ra = ra->next) {
710 			if (scontext->role == ra->role &&
711 			    tcontext->role == ra->new_role)
712 				break;
713 		}
714 		if (!ra)
715 			avd->allowed &= ~policydb.process_trans_perms;
716 	}
717 
718 	/*
719 	 * If the given source and target types have boundary
720 	 * constraint, lazy checks have to mask any violated
721 	 * permission and notice it to userspace via audit.
722 	 */
723 	type_attribute_bounds_av(scontext, tcontext,
724 				 tclass, avd);
725 }
726 
727 static int security_validtrans_handle_fail(struct context *ocontext,
728 					   struct context *ncontext,
729 					   struct context *tcontext,
730 					   u16 tclass)
731 {
732 	char *o = NULL, *n = NULL, *t = NULL;
733 	u32 olen, nlen, tlen;
734 
735 	if (context_struct_to_string(ocontext, &o, &olen))
736 		goto out;
737 	if (context_struct_to_string(ncontext, &n, &nlen))
738 		goto out;
739 	if (context_struct_to_string(tcontext, &t, &tlen))
740 		goto out;
741 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
742 		  "op=security_validate_transition seresult=denied"
743 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
744 		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
745 out:
746 	kfree(o);
747 	kfree(n);
748 	kfree(t);
749 
750 	if (!selinux_enforcing)
751 		return 0;
752 	return -EPERM;
753 }
754 
755 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
756 					  u16 orig_tclass, bool user)
757 {
758 	struct context *ocontext;
759 	struct context *ncontext;
760 	struct context *tcontext;
761 	struct class_datum *tclass_datum;
762 	struct constraint_node *constraint;
763 	u16 tclass;
764 	int rc = 0;
765 
766 	if (!ss_initialized)
767 		return 0;
768 
769 	read_lock(&policy_rwlock);
770 
771 	if (!user)
772 		tclass = unmap_class(orig_tclass);
773 	else
774 		tclass = orig_tclass;
775 
776 	if (!tclass || tclass > policydb.p_classes.nprim) {
777 		rc = -EINVAL;
778 		goto out;
779 	}
780 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
781 
782 	ocontext = sidtab_search(&sidtab, oldsid);
783 	if (!ocontext) {
784 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
785 			__func__, oldsid);
786 		rc = -EINVAL;
787 		goto out;
788 	}
789 
790 	ncontext = sidtab_search(&sidtab, newsid);
791 	if (!ncontext) {
792 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
793 			__func__, newsid);
794 		rc = -EINVAL;
795 		goto out;
796 	}
797 
798 	tcontext = sidtab_search(&sidtab, tasksid);
799 	if (!tcontext) {
800 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
801 			__func__, tasksid);
802 		rc = -EINVAL;
803 		goto out;
804 	}
805 
806 	constraint = tclass_datum->validatetrans;
807 	while (constraint) {
808 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
809 					  constraint->expr)) {
810 			if (user)
811 				rc = -EPERM;
812 			else
813 				rc = security_validtrans_handle_fail(ocontext,
814 								     ncontext,
815 								     tcontext,
816 								     tclass);
817 			goto out;
818 		}
819 		constraint = constraint->next;
820 	}
821 
822 out:
823 	read_unlock(&policy_rwlock);
824 	return rc;
825 }
826 
827 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
828 					u16 tclass)
829 {
830 	return security_compute_validatetrans(oldsid, newsid, tasksid,
831 						tclass, true);
832 }
833 
834 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
835 				 u16 orig_tclass)
836 {
837 	return security_compute_validatetrans(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(u32 old_sid, u32 new_sid)
851 {
852 	struct context *old_context, *new_context;
853 	struct type_datum *type;
854 	int index;
855 	int rc;
856 
857 	read_lock(&policy_rwlock);
858 
859 	rc = -EINVAL;
860 	old_context = sidtab_search(&sidtab, old_sid);
861 	if (!old_context) {
862 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
863 		       __func__, old_sid);
864 		goto out;
865 	}
866 
867 	rc = -EINVAL;
868 	new_context = sidtab_search(&sidtab, new_sid);
869 	if (!new_context) {
870 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
871 		       __func__, new_sid);
872 		goto out;
873 	}
874 
875 	rc = 0;
876 	/* type/domain unchanged */
877 	if (old_context->type == new_context->type)
878 		goto out;
879 
880 	index = new_context->type;
881 	while (true) {
882 		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
883 					  index - 1);
884 		BUG_ON(!type);
885 
886 		/* not bounded anymore */
887 		rc = -EPERM;
888 		if (!type->bounds)
889 			break;
890 
891 		/* @newsid is bounded by @oldsid */
892 		rc = 0;
893 		if (type->bounds == old_context->type)
894 			break;
895 
896 		index = type->bounds;
897 	}
898 
899 	if (rc) {
900 		char *old_name = NULL;
901 		char *new_name = NULL;
902 		u32 length;
903 
904 		if (!context_struct_to_string(old_context,
905 					      &old_name, &length) &&
906 		    !context_struct_to_string(new_context,
907 					      &new_name, &length)) {
908 			audit_log(current->audit_context,
909 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
910 				  "op=security_bounded_transition "
911 				  "seresult=denied "
912 				  "oldcontext=%s newcontext=%s",
913 				  old_name, new_name);
914 		}
915 		kfree(new_name);
916 		kfree(old_name);
917 	}
918 out:
919 	read_unlock(&policy_rwlock);
920 
921 	return rc;
922 }
923 
924 static void avd_init(struct av_decision *avd)
925 {
926 	avd->allowed = 0;
927 	avd->auditallow = 0;
928 	avd->auditdeny = 0xffffffff;
929 	avd->seqno = latest_granting;
930 	avd->flags = 0;
931 }
932 
933 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
934 					struct avtab_node *node)
935 {
936 	unsigned int i;
937 
938 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
939 		if (xpermd->driver != node->datum.u.xperms->driver)
940 			return;
941 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
942 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
943 					xpermd->driver))
944 			return;
945 	} else {
946 		BUG();
947 	}
948 
949 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
950 		xpermd->used |= XPERMS_ALLOWED;
951 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
952 			memset(xpermd->allowed->p, 0xff,
953 					sizeof(xpermd->allowed->p));
954 		}
955 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
956 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
957 				xpermd->allowed->p[i] |=
958 					node->datum.u.xperms->perms.p[i];
959 		}
960 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
961 		xpermd->used |= XPERMS_AUDITALLOW;
962 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
963 			memset(xpermd->auditallow->p, 0xff,
964 					sizeof(xpermd->auditallow->p));
965 		}
966 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
967 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
968 				xpermd->auditallow->p[i] |=
969 					node->datum.u.xperms->perms.p[i];
970 		}
971 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
972 		xpermd->used |= XPERMS_DONTAUDIT;
973 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
974 			memset(xpermd->dontaudit->p, 0xff,
975 					sizeof(xpermd->dontaudit->p));
976 		}
977 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
978 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
979 				xpermd->dontaudit->p[i] |=
980 					node->datum.u.xperms->perms.p[i];
981 		}
982 	} else {
983 		BUG();
984 	}
985 }
986 
987 void security_compute_xperms_decision(u32 ssid,
988 				u32 tsid,
989 				u16 orig_tclass,
990 				u8 driver,
991 				struct extended_perms_decision *xpermd)
992 {
993 	u16 tclass;
994 	struct context *scontext, *tcontext;
995 	struct avtab_key avkey;
996 	struct avtab_node *node;
997 	struct ebitmap *sattr, *tattr;
998 	struct ebitmap_node *snode, *tnode;
999 	unsigned int i, j;
1000 
1001 	xpermd->driver = driver;
1002 	xpermd->used = 0;
1003 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1004 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1005 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1006 
1007 	read_lock(&policy_rwlock);
1008 	if (!ss_initialized)
1009 		goto allow;
1010 
1011 	scontext = sidtab_search(&sidtab, ssid);
1012 	if (!scontext) {
1013 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1014 		       __func__, ssid);
1015 		goto out;
1016 	}
1017 
1018 	tcontext = sidtab_search(&sidtab, tsid);
1019 	if (!tcontext) {
1020 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1021 		       __func__, tsid);
1022 		goto out;
1023 	}
1024 
1025 	tclass = unmap_class(orig_tclass);
1026 	if (unlikely(orig_tclass && !tclass)) {
1027 		if (policydb.allow_unknown)
1028 			goto allow;
1029 		goto out;
1030 	}
1031 
1032 
1033 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1034 		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1035 		goto out;
1036 	}
1037 
1038 	avkey.target_class = tclass;
1039 	avkey.specified = AVTAB_XPERMS;
1040 	sattr = flex_array_get(policydb.type_attr_map_array,
1041 				scontext->type - 1);
1042 	BUG_ON(!sattr);
1043 	tattr = flex_array_get(policydb.type_attr_map_array,
1044 				tcontext->type - 1);
1045 	BUG_ON(!tattr);
1046 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1047 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1048 			avkey.source_type = i + 1;
1049 			avkey.target_type = j + 1;
1050 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1051 			     node;
1052 			     node = avtab_search_node_next(node, avkey.specified))
1053 				services_compute_xperms_decision(xpermd, node);
1054 
1055 			cond_compute_xperms(&policydb.te_cond_avtab,
1056 						&avkey, xpermd);
1057 		}
1058 	}
1059 out:
1060 	read_unlock(&policy_rwlock);
1061 	return;
1062 allow:
1063 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1064 	goto out;
1065 }
1066 
1067 /**
1068  * security_compute_av - Compute access vector decisions.
1069  * @ssid: source security identifier
1070  * @tsid: target security identifier
1071  * @tclass: target security class
1072  * @avd: access vector decisions
1073  * @xperms: extended permissions
1074  *
1075  * Compute a set of access vector decisions based on the
1076  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1077  */
1078 void security_compute_av(u32 ssid,
1079 			 u32 tsid,
1080 			 u16 orig_tclass,
1081 			 struct av_decision *avd,
1082 			 struct extended_perms *xperms)
1083 {
1084 	u16 tclass;
1085 	struct context *scontext = NULL, *tcontext = NULL;
1086 
1087 	read_lock(&policy_rwlock);
1088 	avd_init(avd);
1089 	xperms->len = 0;
1090 	if (!ss_initialized)
1091 		goto allow;
1092 
1093 	scontext = sidtab_search(&sidtab, ssid);
1094 	if (!scontext) {
1095 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1096 		       __func__, ssid);
1097 		goto out;
1098 	}
1099 
1100 	/* permissive domain? */
1101 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1102 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1103 
1104 	tcontext = sidtab_search(&sidtab, tsid);
1105 	if (!tcontext) {
1106 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1107 		       __func__, tsid);
1108 		goto out;
1109 	}
1110 
1111 	tclass = unmap_class(orig_tclass);
1112 	if (unlikely(orig_tclass && !tclass)) {
1113 		if (policydb.allow_unknown)
1114 			goto allow;
1115 		goto out;
1116 	}
1117 	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1118 	map_decision(orig_tclass, avd, policydb.allow_unknown);
1119 out:
1120 	read_unlock(&policy_rwlock);
1121 	return;
1122 allow:
1123 	avd->allowed = 0xffffffff;
1124 	goto out;
1125 }
1126 
1127 void security_compute_av_user(u32 ssid,
1128 			      u32 tsid,
1129 			      u16 tclass,
1130 			      struct av_decision *avd)
1131 {
1132 	struct context *scontext = NULL, *tcontext = NULL;
1133 
1134 	read_lock(&policy_rwlock);
1135 	avd_init(avd);
1136 	if (!ss_initialized)
1137 		goto allow;
1138 
1139 	scontext = sidtab_search(&sidtab, ssid);
1140 	if (!scontext) {
1141 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1142 		       __func__, ssid);
1143 		goto out;
1144 	}
1145 
1146 	/* permissive domain? */
1147 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1148 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1149 
1150 	tcontext = sidtab_search(&sidtab, tsid);
1151 	if (!tcontext) {
1152 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1153 		       __func__, tsid);
1154 		goto out;
1155 	}
1156 
1157 	if (unlikely(!tclass)) {
1158 		if (policydb.allow_unknown)
1159 			goto allow;
1160 		goto out;
1161 	}
1162 
1163 	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1164  out:
1165 	read_unlock(&policy_rwlock);
1166 	return;
1167 allow:
1168 	avd->allowed = 0xffffffff;
1169 	goto out;
1170 }
1171 
1172 /*
1173  * Write the security context string representation of
1174  * the context structure `context' into a dynamically
1175  * allocated string of the correct size.  Set `*scontext'
1176  * to point to this string and set `*scontext_len' to
1177  * the length of the string.
1178  */
1179 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1180 {
1181 	char *scontextp;
1182 
1183 	if (scontext)
1184 		*scontext = NULL;
1185 	*scontext_len = 0;
1186 
1187 	if (context->len) {
1188 		*scontext_len = context->len;
1189 		if (scontext) {
1190 			*scontext = kstrdup(context->str, GFP_ATOMIC);
1191 			if (!(*scontext))
1192 				return -ENOMEM;
1193 		}
1194 		return 0;
1195 	}
1196 
1197 	/* Compute the size of the context. */
1198 	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1199 	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1200 	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1201 	*scontext_len += mls_compute_context_len(context);
1202 
1203 	if (!scontext)
1204 		return 0;
1205 
1206 	/* Allocate space for the context; caller must free this space. */
1207 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1208 	if (!scontextp)
1209 		return -ENOMEM;
1210 	*scontext = scontextp;
1211 
1212 	/*
1213 	 * Copy the user name, role name and type name into the context.
1214 	 */
1215 	scontextp += sprintf(scontextp, "%s:%s:%s",
1216 		sym_name(&policydb, SYM_USERS, context->user - 1),
1217 		sym_name(&policydb, SYM_ROLES, context->role - 1),
1218 		sym_name(&policydb, SYM_TYPES, context->type - 1));
1219 
1220 	mls_sid_to_context(context, &scontextp);
1221 
1222 	*scontextp = 0;
1223 
1224 	return 0;
1225 }
1226 
1227 #include "initial_sid_to_string.h"
1228 
1229 const char *security_get_initial_sid_context(u32 sid)
1230 {
1231 	if (unlikely(sid > SECINITSID_NUM))
1232 		return NULL;
1233 	return initial_sid_to_string[sid];
1234 }
1235 
1236 static int security_sid_to_context_core(u32 sid, char **scontext,
1237 					u32 *scontext_len, int force)
1238 {
1239 	struct context *context;
1240 	int rc = 0;
1241 
1242 	if (scontext)
1243 		*scontext = NULL;
1244 	*scontext_len  = 0;
1245 
1246 	if (!ss_initialized) {
1247 		if (sid <= SECINITSID_NUM) {
1248 			char *scontextp;
1249 
1250 			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1251 			if (!scontext)
1252 				goto out;
1253 			scontextp = kmemdup(initial_sid_to_string[sid],
1254 					    *scontext_len, GFP_ATOMIC);
1255 			if (!scontextp) {
1256 				rc = -ENOMEM;
1257 				goto out;
1258 			}
1259 			*scontext = scontextp;
1260 			goto out;
1261 		}
1262 		printk(KERN_ERR "SELinux: %s:  called before initial "
1263 		       "load_policy on unknown SID %d\n", __func__, sid);
1264 		rc = -EINVAL;
1265 		goto out;
1266 	}
1267 	read_lock(&policy_rwlock);
1268 	if (force)
1269 		context = sidtab_search_force(&sidtab, sid);
1270 	else
1271 		context = sidtab_search(&sidtab, sid);
1272 	if (!context) {
1273 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1274 			__func__, sid);
1275 		rc = -EINVAL;
1276 		goto out_unlock;
1277 	}
1278 	rc = context_struct_to_string(context, scontext, scontext_len);
1279 out_unlock:
1280 	read_unlock(&policy_rwlock);
1281 out:
1282 	return rc;
1283 
1284 }
1285 
1286 /**
1287  * security_sid_to_context - Obtain a context for a given SID.
1288  * @sid: security identifier, SID
1289  * @scontext: security context
1290  * @scontext_len: length in bytes
1291  *
1292  * Write the string representation of the context associated with @sid
1293  * into a dynamically allocated string of the correct size.  Set @scontext
1294  * to point to this string and set @scontext_len to the length of the string.
1295  */
1296 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1297 {
1298 	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1299 }
1300 
1301 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1302 {
1303 	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1304 }
1305 
1306 /*
1307  * Caveat:  Mutates scontext.
1308  */
1309 static int string_to_context_struct(struct policydb *pol,
1310 				    struct sidtab *sidtabp,
1311 				    char *scontext,
1312 				    u32 scontext_len,
1313 				    struct context *ctx,
1314 				    u32 def_sid)
1315 {
1316 	struct role_datum *role;
1317 	struct type_datum *typdatum;
1318 	struct user_datum *usrdatum;
1319 	char *scontextp, *p, oldc;
1320 	int rc = 0;
1321 
1322 	context_init(ctx);
1323 
1324 	/* Parse the security context. */
1325 
1326 	rc = -EINVAL;
1327 	scontextp = (char *) scontext;
1328 
1329 	/* Extract the user. */
1330 	p = scontextp;
1331 	while (*p && *p != ':')
1332 		p++;
1333 
1334 	if (*p == 0)
1335 		goto out;
1336 
1337 	*p++ = 0;
1338 
1339 	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1340 	if (!usrdatum)
1341 		goto out;
1342 
1343 	ctx->user = usrdatum->value;
1344 
1345 	/* Extract role. */
1346 	scontextp = p;
1347 	while (*p && *p != ':')
1348 		p++;
1349 
1350 	if (*p == 0)
1351 		goto out;
1352 
1353 	*p++ = 0;
1354 
1355 	role = hashtab_search(pol->p_roles.table, scontextp);
1356 	if (!role)
1357 		goto out;
1358 	ctx->role = role->value;
1359 
1360 	/* Extract type. */
1361 	scontextp = p;
1362 	while (*p && *p != ':')
1363 		p++;
1364 	oldc = *p;
1365 	*p++ = 0;
1366 
1367 	typdatum = hashtab_search(pol->p_types.table, scontextp);
1368 	if (!typdatum || typdatum->attribute)
1369 		goto out;
1370 
1371 	ctx->type = typdatum->value;
1372 
1373 	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1374 	if (rc)
1375 		goto out;
1376 
1377 	rc = -EINVAL;
1378 	if ((p - scontext) < scontext_len)
1379 		goto out;
1380 
1381 	/* Check the validity of the new context. */
1382 	if (!policydb_context_isvalid(pol, ctx))
1383 		goto out;
1384 	rc = 0;
1385 out:
1386 	if (rc)
1387 		context_destroy(ctx);
1388 	return rc;
1389 }
1390 
1391 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1392 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1393 					int force)
1394 {
1395 	char *scontext2, *str = NULL;
1396 	struct context context;
1397 	int rc = 0;
1398 
1399 	/* An empty security context is never valid. */
1400 	if (!scontext_len)
1401 		return -EINVAL;
1402 
1403 	if (!ss_initialized) {
1404 		int i;
1405 
1406 		for (i = 1; i < SECINITSID_NUM; i++) {
1407 			if (!strcmp(initial_sid_to_string[i], scontext)) {
1408 				*sid = i;
1409 				return 0;
1410 			}
1411 		}
1412 		*sid = SECINITSID_KERNEL;
1413 		return 0;
1414 	}
1415 	*sid = SECSID_NULL;
1416 
1417 	/* Copy the string so that we can modify the copy as we parse it. */
1418 	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1419 	if (!scontext2)
1420 		return -ENOMEM;
1421 	memcpy(scontext2, scontext, scontext_len);
1422 	scontext2[scontext_len] = 0;
1423 
1424 	if (force) {
1425 		/* Save another copy for storing in uninterpreted form */
1426 		rc = -ENOMEM;
1427 		str = kstrdup(scontext2, gfp_flags);
1428 		if (!str)
1429 			goto out;
1430 	}
1431 
1432 	read_lock(&policy_rwlock);
1433 	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1434 				      scontext_len, &context, def_sid);
1435 	if (rc == -EINVAL && force) {
1436 		context.str = str;
1437 		context.len = scontext_len;
1438 		str = NULL;
1439 	} else if (rc)
1440 		goto out_unlock;
1441 	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1442 	context_destroy(&context);
1443 out_unlock:
1444 	read_unlock(&policy_rwlock);
1445 out:
1446 	kfree(scontext2);
1447 	kfree(str);
1448 	return rc;
1449 }
1450 
1451 /**
1452  * security_context_to_sid - Obtain a SID for a given security context.
1453  * @scontext: security context
1454  * @scontext_len: length in bytes
1455  * @sid: security identifier, SID
1456  * @gfp: context for the allocation
1457  *
1458  * Obtains a SID associated with the security context that
1459  * has the string representation specified by @scontext.
1460  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1461  * memory is available, or 0 on success.
1462  */
1463 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1464 			    gfp_t gfp)
1465 {
1466 	return security_context_to_sid_core(scontext, scontext_len,
1467 					    sid, SECSID_NULL, gfp, 0);
1468 }
1469 
1470 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1471 {
1472 	return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1473 }
1474 
1475 /**
1476  * security_context_to_sid_default - Obtain a SID for a given security context,
1477  * falling back to specified default if needed.
1478  *
1479  * @scontext: security context
1480  * @scontext_len: length in bytes
1481  * @sid: security identifier, SID
1482  * @def_sid: default SID to assign on error
1483  *
1484  * Obtains a SID associated with the security context that
1485  * has the string representation specified by @scontext.
1486  * The default SID is passed to the MLS layer to be used to allow
1487  * kernel labeling of the MLS field if the MLS field is not present
1488  * (for upgrading to MLS without full relabel).
1489  * Implicitly forces adding of the context even if it cannot be mapped yet.
1490  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1491  * memory is available, or 0 on success.
1492  */
1493 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1494 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1495 {
1496 	return security_context_to_sid_core(scontext, scontext_len,
1497 					    sid, def_sid, gfp_flags, 1);
1498 }
1499 
1500 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1501 				  u32 *sid)
1502 {
1503 	return security_context_to_sid_core(scontext, scontext_len,
1504 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1505 }
1506 
1507 static int compute_sid_handle_invalid_context(
1508 	struct context *scontext,
1509 	struct context *tcontext,
1510 	u16 tclass,
1511 	struct context *newcontext)
1512 {
1513 	char *s = NULL, *t = NULL, *n = NULL;
1514 	u32 slen, tlen, nlen;
1515 
1516 	if (context_struct_to_string(scontext, &s, &slen))
1517 		goto out;
1518 	if (context_struct_to_string(tcontext, &t, &tlen))
1519 		goto out;
1520 	if (context_struct_to_string(newcontext, &n, &nlen))
1521 		goto out;
1522 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1523 		  "op=security_compute_sid invalid_context=%s"
1524 		  " scontext=%s"
1525 		  " tcontext=%s"
1526 		  " tclass=%s",
1527 		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1528 out:
1529 	kfree(s);
1530 	kfree(t);
1531 	kfree(n);
1532 	if (!selinux_enforcing)
1533 		return 0;
1534 	return -EACCES;
1535 }
1536 
1537 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1538 				  u32 stype, u32 ttype, u16 tclass,
1539 				  const char *objname)
1540 {
1541 	struct filename_trans ft;
1542 	struct filename_trans_datum *otype;
1543 
1544 	/*
1545 	 * Most filename trans rules are going to live in specific directories
1546 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1547 	 * if the ttype does not contain any rules.
1548 	 */
1549 	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1550 		return;
1551 
1552 	ft.stype = stype;
1553 	ft.ttype = ttype;
1554 	ft.tclass = tclass;
1555 	ft.name = objname;
1556 
1557 	otype = hashtab_search(p->filename_trans, &ft);
1558 	if (otype)
1559 		newcontext->type = otype->otype;
1560 }
1561 
1562 static int security_compute_sid(u32 ssid,
1563 				u32 tsid,
1564 				u16 orig_tclass,
1565 				u32 specified,
1566 				const char *objname,
1567 				u32 *out_sid,
1568 				bool kern)
1569 {
1570 	struct class_datum *cladatum = NULL;
1571 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1572 	struct role_trans *roletr = NULL;
1573 	struct avtab_key avkey;
1574 	struct avtab_datum *avdatum;
1575 	struct avtab_node *node;
1576 	u16 tclass;
1577 	int rc = 0;
1578 	bool sock;
1579 
1580 	if (!ss_initialized) {
1581 		switch (orig_tclass) {
1582 		case SECCLASS_PROCESS: /* kernel value */
1583 			*out_sid = ssid;
1584 			break;
1585 		default:
1586 			*out_sid = tsid;
1587 			break;
1588 		}
1589 		goto out;
1590 	}
1591 
1592 	context_init(&newcontext);
1593 
1594 	read_lock(&policy_rwlock);
1595 
1596 	if (kern) {
1597 		tclass = unmap_class(orig_tclass);
1598 		sock = security_is_socket_class(orig_tclass);
1599 	} else {
1600 		tclass = orig_tclass;
1601 		sock = security_is_socket_class(map_class(tclass));
1602 	}
1603 
1604 	scontext = sidtab_search(&sidtab, ssid);
1605 	if (!scontext) {
1606 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1607 		       __func__, ssid);
1608 		rc = -EINVAL;
1609 		goto out_unlock;
1610 	}
1611 	tcontext = sidtab_search(&sidtab, tsid);
1612 	if (!tcontext) {
1613 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1614 		       __func__, tsid);
1615 		rc = -EINVAL;
1616 		goto out_unlock;
1617 	}
1618 
1619 	if (tclass && tclass <= policydb.p_classes.nprim)
1620 		cladatum = policydb.class_val_to_struct[tclass - 1];
1621 
1622 	/* Set the user identity. */
1623 	switch (specified) {
1624 	case AVTAB_TRANSITION:
1625 	case AVTAB_CHANGE:
1626 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1627 			newcontext.user = tcontext->user;
1628 		} else {
1629 			/* notice this gets both DEFAULT_SOURCE and unset */
1630 			/* Use the process user identity. */
1631 			newcontext.user = scontext->user;
1632 		}
1633 		break;
1634 	case AVTAB_MEMBER:
1635 		/* Use the related object owner. */
1636 		newcontext.user = tcontext->user;
1637 		break;
1638 	}
1639 
1640 	/* Set the role to default values. */
1641 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1642 		newcontext.role = scontext->role;
1643 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1644 		newcontext.role = tcontext->role;
1645 	} else {
1646 		if ((tclass == policydb.process_class) || (sock == true))
1647 			newcontext.role = scontext->role;
1648 		else
1649 			newcontext.role = OBJECT_R_VAL;
1650 	}
1651 
1652 	/* Set the type to default values. */
1653 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1654 		newcontext.type = scontext->type;
1655 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1656 		newcontext.type = tcontext->type;
1657 	} else {
1658 		if ((tclass == policydb.process_class) || (sock == true)) {
1659 			/* Use the type of process. */
1660 			newcontext.type = scontext->type;
1661 		} else {
1662 			/* Use the type of the related object. */
1663 			newcontext.type = tcontext->type;
1664 		}
1665 	}
1666 
1667 	/* Look for a type transition/member/change rule. */
1668 	avkey.source_type = scontext->type;
1669 	avkey.target_type = tcontext->type;
1670 	avkey.target_class = tclass;
1671 	avkey.specified = specified;
1672 	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1673 
1674 	/* If no permanent rule, also check for enabled conditional rules */
1675 	if (!avdatum) {
1676 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1677 		for (; node; node = avtab_search_node_next(node, specified)) {
1678 			if (node->key.specified & AVTAB_ENABLED) {
1679 				avdatum = &node->datum;
1680 				break;
1681 			}
1682 		}
1683 	}
1684 
1685 	if (avdatum) {
1686 		/* Use the type from the type transition/member/change rule. */
1687 		newcontext.type = avdatum->u.data;
1688 	}
1689 
1690 	/* if we have a objname this is a file trans check so check those rules */
1691 	if (objname)
1692 		filename_compute_type(&policydb, &newcontext, scontext->type,
1693 				      tcontext->type, tclass, objname);
1694 
1695 	/* Check for class-specific changes. */
1696 	if (specified & AVTAB_TRANSITION) {
1697 		/* Look for a role transition rule. */
1698 		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1699 			if ((roletr->role == scontext->role) &&
1700 			    (roletr->type == tcontext->type) &&
1701 			    (roletr->tclass == tclass)) {
1702 				/* Use the role transition rule. */
1703 				newcontext.role = roletr->new_role;
1704 				break;
1705 			}
1706 		}
1707 	}
1708 
1709 	/* Set the MLS attributes.
1710 	   This is done last because it may allocate memory. */
1711 	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1712 			     &newcontext, sock);
1713 	if (rc)
1714 		goto out_unlock;
1715 
1716 	/* Check the validity of the context. */
1717 	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1718 		rc = compute_sid_handle_invalid_context(scontext,
1719 							tcontext,
1720 							tclass,
1721 							&newcontext);
1722 		if (rc)
1723 			goto out_unlock;
1724 	}
1725 	/* Obtain the sid for the context. */
1726 	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1727 out_unlock:
1728 	read_unlock(&policy_rwlock);
1729 	context_destroy(&newcontext);
1730 out:
1731 	return rc;
1732 }
1733 
1734 /**
1735  * security_transition_sid - Compute the SID for a new subject/object.
1736  * @ssid: source security identifier
1737  * @tsid: target security identifier
1738  * @tclass: target security class
1739  * @out_sid: security identifier for new subject/object
1740  *
1741  * Compute a SID to use for labeling a new subject or object in the
1742  * class @tclass based on a SID pair (@ssid, @tsid).
1743  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1744  * if insufficient memory is available, or %0 if the new SID was
1745  * computed successfully.
1746  */
1747 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1748 			    const struct qstr *qstr, u32 *out_sid)
1749 {
1750 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1751 				    qstr ? qstr->name : NULL, out_sid, true);
1752 }
1753 
1754 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1755 				 const char *objname, u32 *out_sid)
1756 {
1757 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1758 				    objname, out_sid, false);
1759 }
1760 
1761 /**
1762  * security_member_sid - Compute the SID for member selection.
1763  * @ssid: source security identifier
1764  * @tsid: target security identifier
1765  * @tclass: target security class
1766  * @out_sid: security identifier for selected member
1767  *
1768  * Compute a SID to use when selecting a member of a polyinstantiated
1769  * object of class @tclass based on a SID pair (@ssid, @tsid).
1770  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1771  * if insufficient memory is available, or %0 if the SID was
1772  * computed successfully.
1773  */
1774 int security_member_sid(u32 ssid,
1775 			u32 tsid,
1776 			u16 tclass,
1777 			u32 *out_sid)
1778 {
1779 	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1780 				    out_sid, false);
1781 }
1782 
1783 /**
1784  * security_change_sid - Compute the SID for object relabeling.
1785  * @ssid: source security identifier
1786  * @tsid: target security identifier
1787  * @tclass: target security class
1788  * @out_sid: security identifier for selected member
1789  *
1790  * Compute a SID to use for relabeling an object of class @tclass
1791  * based on a SID pair (@ssid, @tsid).
1792  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1793  * if insufficient memory is available, or %0 if the SID was
1794  * computed successfully.
1795  */
1796 int security_change_sid(u32 ssid,
1797 			u32 tsid,
1798 			u16 tclass,
1799 			u32 *out_sid)
1800 {
1801 	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1802 				    out_sid, false);
1803 }
1804 
1805 /* Clone the SID into the new SID table. */
1806 static int clone_sid(u32 sid,
1807 		     struct context *context,
1808 		     void *arg)
1809 {
1810 	struct sidtab *s = arg;
1811 
1812 	if (sid > SECINITSID_NUM)
1813 		return sidtab_insert(s, sid, context);
1814 	else
1815 		return 0;
1816 }
1817 
1818 static inline int convert_context_handle_invalid_context(struct context *context)
1819 {
1820 	char *s;
1821 	u32 len;
1822 
1823 	if (selinux_enforcing)
1824 		return -EINVAL;
1825 
1826 	if (!context_struct_to_string(context, &s, &len)) {
1827 		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1828 		kfree(s);
1829 	}
1830 	return 0;
1831 }
1832 
1833 struct convert_context_args {
1834 	struct policydb *oldp;
1835 	struct policydb *newp;
1836 };
1837 
1838 /*
1839  * Convert the values in the security context
1840  * structure `c' from the values specified
1841  * in the policy `p->oldp' to the values specified
1842  * in the policy `p->newp'.  Verify that the
1843  * context is valid under the new policy.
1844  */
1845 static int convert_context(u32 key,
1846 			   struct context *c,
1847 			   void *p)
1848 {
1849 	struct convert_context_args *args;
1850 	struct context oldc;
1851 	struct ocontext *oc;
1852 	struct mls_range *range;
1853 	struct role_datum *role;
1854 	struct type_datum *typdatum;
1855 	struct user_datum *usrdatum;
1856 	char *s;
1857 	u32 len;
1858 	int rc = 0;
1859 
1860 	if (key <= SECINITSID_NUM)
1861 		goto out;
1862 
1863 	args = p;
1864 
1865 	if (c->str) {
1866 		struct context ctx;
1867 
1868 		rc = -ENOMEM;
1869 		s = kstrdup(c->str, GFP_KERNEL);
1870 		if (!s)
1871 			goto out;
1872 
1873 		rc = string_to_context_struct(args->newp, NULL, s,
1874 					      c->len, &ctx, SECSID_NULL);
1875 		kfree(s);
1876 		if (!rc) {
1877 			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1878 			       c->str);
1879 			/* Replace string with mapped representation. */
1880 			kfree(c->str);
1881 			memcpy(c, &ctx, sizeof(*c));
1882 			goto out;
1883 		} else if (rc == -EINVAL) {
1884 			/* Retain string representation for later mapping. */
1885 			rc = 0;
1886 			goto out;
1887 		} else {
1888 			/* Other error condition, e.g. ENOMEM. */
1889 			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1890 			       c->str, -rc);
1891 			goto out;
1892 		}
1893 	}
1894 
1895 	rc = context_cpy(&oldc, c);
1896 	if (rc)
1897 		goto out;
1898 
1899 	/* Convert the user. */
1900 	rc = -EINVAL;
1901 	usrdatum = hashtab_search(args->newp->p_users.table,
1902 				  sym_name(args->oldp, SYM_USERS, c->user - 1));
1903 	if (!usrdatum)
1904 		goto bad;
1905 	c->user = usrdatum->value;
1906 
1907 	/* Convert the role. */
1908 	rc = -EINVAL;
1909 	role = hashtab_search(args->newp->p_roles.table,
1910 			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
1911 	if (!role)
1912 		goto bad;
1913 	c->role = role->value;
1914 
1915 	/* Convert the type. */
1916 	rc = -EINVAL;
1917 	typdatum = hashtab_search(args->newp->p_types.table,
1918 				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
1919 	if (!typdatum)
1920 		goto bad;
1921 	c->type = typdatum->value;
1922 
1923 	/* Convert the MLS fields if dealing with MLS policies */
1924 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1925 		rc = mls_convert_context(args->oldp, args->newp, c);
1926 		if (rc)
1927 			goto bad;
1928 	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1929 		/*
1930 		 * Switching between MLS and non-MLS policy:
1931 		 * free any storage used by the MLS fields in the
1932 		 * context for all existing entries in the sidtab.
1933 		 */
1934 		mls_context_destroy(c);
1935 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1936 		/*
1937 		 * Switching between non-MLS and MLS policy:
1938 		 * ensure that the MLS fields of the context for all
1939 		 * existing entries in the sidtab are filled in with a
1940 		 * suitable default value, likely taken from one of the
1941 		 * initial SIDs.
1942 		 */
1943 		oc = args->newp->ocontexts[OCON_ISID];
1944 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1945 			oc = oc->next;
1946 		rc = -EINVAL;
1947 		if (!oc) {
1948 			printk(KERN_ERR "SELinux:  unable to look up"
1949 				" the initial SIDs list\n");
1950 			goto bad;
1951 		}
1952 		range = &oc->context[0].range;
1953 		rc = mls_range_set(c, range);
1954 		if (rc)
1955 			goto bad;
1956 	}
1957 
1958 	/* Check the validity of the new context. */
1959 	if (!policydb_context_isvalid(args->newp, c)) {
1960 		rc = convert_context_handle_invalid_context(&oldc);
1961 		if (rc)
1962 			goto bad;
1963 	}
1964 
1965 	context_destroy(&oldc);
1966 
1967 	rc = 0;
1968 out:
1969 	return rc;
1970 bad:
1971 	/* Map old representation to string and save it. */
1972 	rc = context_struct_to_string(&oldc, &s, &len);
1973 	if (rc)
1974 		return rc;
1975 	context_destroy(&oldc);
1976 	context_destroy(c);
1977 	c->str = s;
1978 	c->len = len;
1979 	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1980 	       c->str);
1981 	rc = 0;
1982 	goto out;
1983 }
1984 
1985 static void security_load_policycaps(void)
1986 {
1987 	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1988 						  POLICYDB_CAPABILITY_NETPEER);
1989 	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1990 						  POLICYDB_CAPABILITY_OPENPERM);
1991 	selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1992 						  POLICYDB_CAPABILITY_ALWAYSNETWORK);
1993 }
1994 
1995 static int security_preserve_bools(struct policydb *p);
1996 
1997 /**
1998  * security_load_policy - Load a security policy configuration.
1999  * @data: binary policy data
2000  * @len: length of data in bytes
2001  *
2002  * Load a new set of security policy configuration data,
2003  * validate it and convert the SID table as necessary.
2004  * This function will flush the access vector cache after
2005  * loading the new policy.
2006  */
2007 int security_load_policy(void *data, size_t len)
2008 {
2009 	struct policydb *oldpolicydb, *newpolicydb;
2010 	struct sidtab oldsidtab, newsidtab;
2011 	struct selinux_mapping *oldmap, *map = NULL;
2012 	struct convert_context_args args;
2013 	u32 seqno;
2014 	u16 map_size;
2015 	int rc = 0;
2016 	struct policy_file file = { data, len }, *fp = &file;
2017 
2018 	oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2019 	if (!oldpolicydb) {
2020 		rc = -ENOMEM;
2021 		goto out;
2022 	}
2023 	newpolicydb = oldpolicydb + 1;
2024 
2025 	if (!ss_initialized) {
2026 		avtab_cache_init();
2027 		rc = policydb_read(&policydb, fp);
2028 		if (rc) {
2029 			avtab_cache_destroy();
2030 			goto out;
2031 		}
2032 
2033 		policydb.len = len;
2034 		rc = selinux_set_mapping(&policydb, secclass_map,
2035 					 &current_mapping,
2036 					 &current_mapping_size);
2037 		if (rc) {
2038 			policydb_destroy(&policydb);
2039 			avtab_cache_destroy();
2040 			goto out;
2041 		}
2042 
2043 		rc = policydb_load_isids(&policydb, &sidtab);
2044 		if (rc) {
2045 			policydb_destroy(&policydb);
2046 			avtab_cache_destroy();
2047 			goto out;
2048 		}
2049 
2050 		security_load_policycaps();
2051 		ss_initialized = 1;
2052 		seqno = ++latest_granting;
2053 		selinux_complete_init();
2054 		avc_ss_reset(seqno);
2055 		selnl_notify_policyload(seqno);
2056 		selinux_status_update_policyload(seqno);
2057 		selinux_netlbl_cache_invalidate();
2058 		selinux_xfrm_notify_policyload();
2059 		goto out;
2060 	}
2061 
2062 #if 0
2063 	sidtab_hash_eval(&sidtab, "sids");
2064 #endif
2065 
2066 	rc = policydb_read(newpolicydb, fp);
2067 	if (rc)
2068 		goto out;
2069 
2070 	newpolicydb->len = len;
2071 	/* If switching between different policy types, log MLS status */
2072 	if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2073 		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2074 	else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2075 		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2076 
2077 	rc = policydb_load_isids(newpolicydb, &newsidtab);
2078 	if (rc) {
2079 		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2080 		policydb_destroy(newpolicydb);
2081 		goto out;
2082 	}
2083 
2084 	rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2085 	if (rc)
2086 		goto err;
2087 
2088 	rc = security_preserve_bools(newpolicydb);
2089 	if (rc) {
2090 		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2091 		goto err;
2092 	}
2093 
2094 	/* Clone the SID table. */
2095 	sidtab_shutdown(&sidtab);
2096 
2097 	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2098 	if (rc)
2099 		goto err;
2100 
2101 	/*
2102 	 * Convert the internal representations of contexts
2103 	 * in the new SID table.
2104 	 */
2105 	args.oldp = &policydb;
2106 	args.newp = newpolicydb;
2107 	rc = sidtab_map(&newsidtab, convert_context, &args);
2108 	if (rc) {
2109 		printk(KERN_ERR "SELinux:  unable to convert the internal"
2110 			" representation of contexts in the new SID"
2111 			" table\n");
2112 		goto err;
2113 	}
2114 
2115 	/* Save the old policydb and SID table to free later. */
2116 	memcpy(oldpolicydb, &policydb, sizeof(policydb));
2117 	sidtab_set(&oldsidtab, &sidtab);
2118 
2119 	/* Install the new policydb and SID table. */
2120 	write_lock_irq(&policy_rwlock);
2121 	memcpy(&policydb, newpolicydb, sizeof(policydb));
2122 	sidtab_set(&sidtab, &newsidtab);
2123 	security_load_policycaps();
2124 	oldmap = current_mapping;
2125 	current_mapping = map;
2126 	current_mapping_size = map_size;
2127 	seqno = ++latest_granting;
2128 	write_unlock_irq(&policy_rwlock);
2129 
2130 	/* Free the old policydb and SID table. */
2131 	policydb_destroy(oldpolicydb);
2132 	sidtab_destroy(&oldsidtab);
2133 	kfree(oldmap);
2134 
2135 	avc_ss_reset(seqno);
2136 	selnl_notify_policyload(seqno);
2137 	selinux_status_update_policyload(seqno);
2138 	selinux_netlbl_cache_invalidate();
2139 	selinux_xfrm_notify_policyload();
2140 
2141 	rc = 0;
2142 	goto out;
2143 
2144 err:
2145 	kfree(map);
2146 	sidtab_destroy(&newsidtab);
2147 	policydb_destroy(newpolicydb);
2148 
2149 out:
2150 	kfree(oldpolicydb);
2151 	return rc;
2152 }
2153 
2154 size_t security_policydb_len(void)
2155 {
2156 	size_t len;
2157 
2158 	read_lock(&policy_rwlock);
2159 	len = policydb.len;
2160 	read_unlock(&policy_rwlock);
2161 
2162 	return len;
2163 }
2164 
2165 /**
2166  * security_port_sid - Obtain the SID for a port.
2167  * @protocol: protocol number
2168  * @port: port number
2169  * @out_sid: security identifier
2170  */
2171 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2172 {
2173 	struct ocontext *c;
2174 	int rc = 0;
2175 
2176 	read_lock(&policy_rwlock);
2177 
2178 	c = policydb.ocontexts[OCON_PORT];
2179 	while (c) {
2180 		if (c->u.port.protocol == protocol &&
2181 		    c->u.port.low_port <= port &&
2182 		    c->u.port.high_port >= port)
2183 			break;
2184 		c = c->next;
2185 	}
2186 
2187 	if (c) {
2188 		if (!c->sid[0]) {
2189 			rc = sidtab_context_to_sid(&sidtab,
2190 						   &c->context[0],
2191 						   &c->sid[0]);
2192 			if (rc)
2193 				goto out;
2194 		}
2195 		*out_sid = c->sid[0];
2196 	} else {
2197 		*out_sid = SECINITSID_PORT;
2198 	}
2199 
2200 out:
2201 	read_unlock(&policy_rwlock);
2202 	return rc;
2203 }
2204 
2205 /**
2206  * security_netif_sid - Obtain the SID for a network interface.
2207  * @name: interface name
2208  * @if_sid: interface SID
2209  */
2210 int security_netif_sid(char *name, u32 *if_sid)
2211 {
2212 	int rc = 0;
2213 	struct ocontext *c;
2214 
2215 	read_lock(&policy_rwlock);
2216 
2217 	c = policydb.ocontexts[OCON_NETIF];
2218 	while (c) {
2219 		if (strcmp(name, c->u.name) == 0)
2220 			break;
2221 		c = c->next;
2222 	}
2223 
2224 	if (c) {
2225 		if (!c->sid[0] || !c->sid[1]) {
2226 			rc = sidtab_context_to_sid(&sidtab,
2227 						  &c->context[0],
2228 						  &c->sid[0]);
2229 			if (rc)
2230 				goto out;
2231 			rc = sidtab_context_to_sid(&sidtab,
2232 						   &c->context[1],
2233 						   &c->sid[1]);
2234 			if (rc)
2235 				goto out;
2236 		}
2237 		*if_sid = c->sid[0];
2238 	} else
2239 		*if_sid = SECINITSID_NETIF;
2240 
2241 out:
2242 	read_unlock(&policy_rwlock);
2243 	return rc;
2244 }
2245 
2246 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2247 {
2248 	int i, fail = 0;
2249 
2250 	for (i = 0; i < 4; i++)
2251 		if (addr[i] != (input[i] & mask[i])) {
2252 			fail = 1;
2253 			break;
2254 		}
2255 
2256 	return !fail;
2257 }
2258 
2259 /**
2260  * security_node_sid - Obtain the SID for a node (host).
2261  * @domain: communication domain aka address family
2262  * @addrp: address
2263  * @addrlen: address length in bytes
2264  * @out_sid: security identifier
2265  */
2266 int security_node_sid(u16 domain,
2267 		      void *addrp,
2268 		      u32 addrlen,
2269 		      u32 *out_sid)
2270 {
2271 	int rc;
2272 	struct ocontext *c;
2273 
2274 	read_lock(&policy_rwlock);
2275 
2276 	switch (domain) {
2277 	case AF_INET: {
2278 		u32 addr;
2279 
2280 		rc = -EINVAL;
2281 		if (addrlen != sizeof(u32))
2282 			goto out;
2283 
2284 		addr = *((u32 *)addrp);
2285 
2286 		c = policydb.ocontexts[OCON_NODE];
2287 		while (c) {
2288 			if (c->u.node.addr == (addr & c->u.node.mask))
2289 				break;
2290 			c = c->next;
2291 		}
2292 		break;
2293 	}
2294 
2295 	case AF_INET6:
2296 		rc = -EINVAL;
2297 		if (addrlen != sizeof(u64) * 2)
2298 			goto out;
2299 		c = policydb.ocontexts[OCON_NODE6];
2300 		while (c) {
2301 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2302 						c->u.node6.mask))
2303 				break;
2304 			c = c->next;
2305 		}
2306 		break;
2307 
2308 	default:
2309 		rc = 0;
2310 		*out_sid = SECINITSID_NODE;
2311 		goto out;
2312 	}
2313 
2314 	if (c) {
2315 		if (!c->sid[0]) {
2316 			rc = sidtab_context_to_sid(&sidtab,
2317 						   &c->context[0],
2318 						   &c->sid[0]);
2319 			if (rc)
2320 				goto out;
2321 		}
2322 		*out_sid = c->sid[0];
2323 	} else {
2324 		*out_sid = SECINITSID_NODE;
2325 	}
2326 
2327 	rc = 0;
2328 out:
2329 	read_unlock(&policy_rwlock);
2330 	return rc;
2331 }
2332 
2333 #define SIDS_NEL 25
2334 
2335 /**
2336  * security_get_user_sids - Obtain reachable SIDs for a user.
2337  * @fromsid: starting SID
2338  * @username: username
2339  * @sids: array of reachable SIDs for user
2340  * @nel: number of elements in @sids
2341  *
2342  * Generate the set of SIDs for legal security contexts
2343  * for a given user that can be reached by @fromsid.
2344  * Set *@sids to point to a dynamically allocated
2345  * array containing the set of SIDs.  Set *@nel to the
2346  * number of elements in the array.
2347  */
2348 
2349 int security_get_user_sids(u32 fromsid,
2350 			   char *username,
2351 			   u32 **sids,
2352 			   u32 *nel)
2353 {
2354 	struct context *fromcon, usercon;
2355 	u32 *mysids = NULL, *mysids2, sid;
2356 	u32 mynel = 0, maxnel = SIDS_NEL;
2357 	struct user_datum *user;
2358 	struct role_datum *role;
2359 	struct ebitmap_node *rnode, *tnode;
2360 	int rc = 0, i, j;
2361 
2362 	*sids = NULL;
2363 	*nel = 0;
2364 
2365 	if (!ss_initialized)
2366 		goto out;
2367 
2368 	read_lock(&policy_rwlock);
2369 
2370 	context_init(&usercon);
2371 
2372 	rc = -EINVAL;
2373 	fromcon = sidtab_search(&sidtab, fromsid);
2374 	if (!fromcon)
2375 		goto out_unlock;
2376 
2377 	rc = -EINVAL;
2378 	user = hashtab_search(policydb.p_users.table, username);
2379 	if (!user)
2380 		goto out_unlock;
2381 
2382 	usercon.user = user->value;
2383 
2384 	rc = -ENOMEM;
2385 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2386 	if (!mysids)
2387 		goto out_unlock;
2388 
2389 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2390 		role = policydb.role_val_to_struct[i];
2391 		usercon.role = i + 1;
2392 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2393 			usercon.type = j + 1;
2394 
2395 			if (mls_setup_user_range(fromcon, user, &usercon))
2396 				continue;
2397 
2398 			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2399 			if (rc)
2400 				goto out_unlock;
2401 			if (mynel < maxnel) {
2402 				mysids[mynel++] = sid;
2403 			} else {
2404 				rc = -ENOMEM;
2405 				maxnel += SIDS_NEL;
2406 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2407 				if (!mysids2)
2408 					goto out_unlock;
2409 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2410 				kfree(mysids);
2411 				mysids = mysids2;
2412 				mysids[mynel++] = sid;
2413 			}
2414 		}
2415 	}
2416 	rc = 0;
2417 out_unlock:
2418 	read_unlock(&policy_rwlock);
2419 	if (rc || !mynel) {
2420 		kfree(mysids);
2421 		goto out;
2422 	}
2423 
2424 	rc = -ENOMEM;
2425 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2426 	if (!mysids2) {
2427 		kfree(mysids);
2428 		goto out;
2429 	}
2430 	for (i = 0, j = 0; i < mynel; i++) {
2431 		struct av_decision dummy_avd;
2432 		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2433 					  SECCLASS_PROCESS, /* kernel value */
2434 					  PROCESS__TRANSITION, AVC_STRICT,
2435 					  &dummy_avd);
2436 		if (!rc)
2437 			mysids2[j++] = mysids[i];
2438 		cond_resched();
2439 	}
2440 	rc = 0;
2441 	kfree(mysids);
2442 	*sids = mysids2;
2443 	*nel = j;
2444 out:
2445 	return rc;
2446 }
2447 
2448 /**
2449  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2450  * @fstype: filesystem type
2451  * @path: path from root of mount
2452  * @sclass: file security class
2453  * @sid: SID for path
2454  *
2455  * Obtain a SID to use for a file in a filesystem that
2456  * cannot support xattr or use a fixed labeling behavior like
2457  * transition SIDs or task SIDs.
2458  *
2459  * The caller must acquire the policy_rwlock before calling this function.
2460  */
2461 static inline int __security_genfs_sid(const char *fstype,
2462 				       char *path,
2463 				       u16 orig_sclass,
2464 				       u32 *sid)
2465 {
2466 	int len;
2467 	u16 sclass;
2468 	struct genfs *genfs;
2469 	struct ocontext *c;
2470 	int rc, cmp = 0;
2471 
2472 	while (path[0] == '/' && path[1] == '/')
2473 		path++;
2474 
2475 	sclass = unmap_class(orig_sclass);
2476 	*sid = SECINITSID_UNLABELED;
2477 
2478 	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2479 		cmp = strcmp(fstype, genfs->fstype);
2480 		if (cmp <= 0)
2481 			break;
2482 	}
2483 
2484 	rc = -ENOENT;
2485 	if (!genfs || cmp)
2486 		goto out;
2487 
2488 	for (c = genfs->head; c; c = c->next) {
2489 		len = strlen(c->u.name);
2490 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2491 		    (strncmp(c->u.name, path, len) == 0))
2492 			break;
2493 	}
2494 
2495 	rc = -ENOENT;
2496 	if (!c)
2497 		goto out;
2498 
2499 	if (!c->sid[0]) {
2500 		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2501 		if (rc)
2502 			goto out;
2503 	}
2504 
2505 	*sid = c->sid[0];
2506 	rc = 0;
2507 out:
2508 	return rc;
2509 }
2510 
2511 /**
2512  * security_genfs_sid - Obtain a SID for a file in a filesystem
2513  * @fstype: filesystem type
2514  * @path: path from root of mount
2515  * @sclass: file security class
2516  * @sid: SID for path
2517  *
2518  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2519  * it afterward.
2520  */
2521 int security_genfs_sid(const char *fstype,
2522 		       char *path,
2523 		       u16 orig_sclass,
2524 		       u32 *sid)
2525 {
2526 	int retval;
2527 
2528 	read_lock(&policy_rwlock);
2529 	retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2530 	read_unlock(&policy_rwlock);
2531 	return retval;
2532 }
2533 
2534 /**
2535  * security_fs_use - Determine how to handle labeling for a filesystem.
2536  * @sb: superblock in question
2537  */
2538 int security_fs_use(struct super_block *sb)
2539 {
2540 	int rc = 0;
2541 	struct ocontext *c;
2542 	struct superblock_security_struct *sbsec = sb->s_security;
2543 	const char *fstype = sb->s_type->name;
2544 
2545 	read_lock(&policy_rwlock);
2546 
2547 	c = policydb.ocontexts[OCON_FSUSE];
2548 	while (c) {
2549 		if (strcmp(fstype, c->u.name) == 0)
2550 			break;
2551 		c = c->next;
2552 	}
2553 
2554 	if (c) {
2555 		sbsec->behavior = c->v.behavior;
2556 		if (!c->sid[0]) {
2557 			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2558 						   &c->sid[0]);
2559 			if (rc)
2560 				goto out;
2561 		}
2562 		sbsec->sid = c->sid[0];
2563 	} else {
2564 		rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2565 					  &sbsec->sid);
2566 		if (rc) {
2567 			sbsec->behavior = SECURITY_FS_USE_NONE;
2568 			rc = 0;
2569 		} else {
2570 			sbsec->behavior = SECURITY_FS_USE_GENFS;
2571 		}
2572 	}
2573 
2574 out:
2575 	read_unlock(&policy_rwlock);
2576 	return rc;
2577 }
2578 
2579 int security_get_bools(int *len, char ***names, int **values)
2580 {
2581 	int i, rc;
2582 
2583 	read_lock(&policy_rwlock);
2584 	*names = NULL;
2585 	*values = NULL;
2586 
2587 	rc = 0;
2588 	*len = policydb.p_bools.nprim;
2589 	if (!*len)
2590 		goto out;
2591 
2592 	rc = -ENOMEM;
2593 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2594 	if (!*names)
2595 		goto err;
2596 
2597 	rc = -ENOMEM;
2598 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2599 	if (!*values)
2600 		goto err;
2601 
2602 	for (i = 0; i < *len; i++) {
2603 		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2604 
2605 		rc = -ENOMEM;
2606 		(*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2607 		if (!(*names)[i])
2608 			goto err;
2609 	}
2610 	rc = 0;
2611 out:
2612 	read_unlock(&policy_rwlock);
2613 	return rc;
2614 err:
2615 	if (*names) {
2616 		for (i = 0; i < *len; i++)
2617 			kfree((*names)[i]);
2618 	}
2619 	kfree(*values);
2620 	goto out;
2621 }
2622 
2623 
2624 int security_set_bools(int len, int *values)
2625 {
2626 	int i, rc;
2627 	int lenp, seqno = 0;
2628 	struct cond_node *cur;
2629 
2630 	write_lock_irq(&policy_rwlock);
2631 
2632 	rc = -EFAULT;
2633 	lenp = policydb.p_bools.nprim;
2634 	if (len != lenp)
2635 		goto out;
2636 
2637 	for (i = 0; i < len; i++) {
2638 		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2639 			audit_log(current->audit_context, GFP_ATOMIC,
2640 				AUDIT_MAC_CONFIG_CHANGE,
2641 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2642 				sym_name(&policydb, SYM_BOOLS, i),
2643 				!!values[i],
2644 				policydb.bool_val_to_struct[i]->state,
2645 				from_kuid(&init_user_ns, audit_get_loginuid(current)),
2646 				audit_get_sessionid(current));
2647 		}
2648 		if (values[i])
2649 			policydb.bool_val_to_struct[i]->state = 1;
2650 		else
2651 			policydb.bool_val_to_struct[i]->state = 0;
2652 	}
2653 
2654 	for (cur = policydb.cond_list; cur; cur = cur->next) {
2655 		rc = evaluate_cond_node(&policydb, cur);
2656 		if (rc)
2657 			goto out;
2658 	}
2659 
2660 	seqno = ++latest_granting;
2661 	rc = 0;
2662 out:
2663 	write_unlock_irq(&policy_rwlock);
2664 	if (!rc) {
2665 		avc_ss_reset(seqno);
2666 		selnl_notify_policyload(seqno);
2667 		selinux_status_update_policyload(seqno);
2668 		selinux_xfrm_notify_policyload();
2669 	}
2670 	return rc;
2671 }
2672 
2673 int security_get_bool_value(int index)
2674 {
2675 	int rc;
2676 	int len;
2677 
2678 	read_lock(&policy_rwlock);
2679 
2680 	rc = -EFAULT;
2681 	len = policydb.p_bools.nprim;
2682 	if (index >= len)
2683 		goto out;
2684 
2685 	rc = policydb.bool_val_to_struct[index]->state;
2686 out:
2687 	read_unlock(&policy_rwlock);
2688 	return rc;
2689 }
2690 
2691 static int security_preserve_bools(struct policydb *p)
2692 {
2693 	int rc, nbools = 0, *bvalues = NULL, i;
2694 	char **bnames = NULL;
2695 	struct cond_bool_datum *booldatum;
2696 	struct cond_node *cur;
2697 
2698 	rc = security_get_bools(&nbools, &bnames, &bvalues);
2699 	if (rc)
2700 		goto out;
2701 	for (i = 0; i < nbools; i++) {
2702 		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2703 		if (booldatum)
2704 			booldatum->state = bvalues[i];
2705 	}
2706 	for (cur = p->cond_list; cur; cur = cur->next) {
2707 		rc = evaluate_cond_node(p, cur);
2708 		if (rc)
2709 			goto out;
2710 	}
2711 
2712 out:
2713 	if (bnames) {
2714 		for (i = 0; i < nbools; i++)
2715 			kfree(bnames[i]);
2716 	}
2717 	kfree(bnames);
2718 	kfree(bvalues);
2719 	return rc;
2720 }
2721 
2722 /*
2723  * security_sid_mls_copy() - computes a new sid based on the given
2724  * sid and the mls portion of mls_sid.
2725  */
2726 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2727 {
2728 	struct context *context1;
2729 	struct context *context2;
2730 	struct context newcon;
2731 	char *s;
2732 	u32 len;
2733 	int rc;
2734 
2735 	rc = 0;
2736 	if (!ss_initialized || !policydb.mls_enabled) {
2737 		*new_sid = sid;
2738 		goto out;
2739 	}
2740 
2741 	context_init(&newcon);
2742 
2743 	read_lock(&policy_rwlock);
2744 
2745 	rc = -EINVAL;
2746 	context1 = sidtab_search(&sidtab, sid);
2747 	if (!context1) {
2748 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2749 			__func__, sid);
2750 		goto out_unlock;
2751 	}
2752 
2753 	rc = -EINVAL;
2754 	context2 = sidtab_search(&sidtab, mls_sid);
2755 	if (!context2) {
2756 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2757 			__func__, mls_sid);
2758 		goto out_unlock;
2759 	}
2760 
2761 	newcon.user = context1->user;
2762 	newcon.role = context1->role;
2763 	newcon.type = context1->type;
2764 	rc = mls_context_cpy(&newcon, context2);
2765 	if (rc)
2766 		goto out_unlock;
2767 
2768 	/* Check the validity of the new context. */
2769 	if (!policydb_context_isvalid(&policydb, &newcon)) {
2770 		rc = convert_context_handle_invalid_context(&newcon);
2771 		if (rc) {
2772 			if (!context_struct_to_string(&newcon, &s, &len)) {
2773 				audit_log(current->audit_context,
2774 					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
2775 					  "op=security_sid_mls_copy "
2776 					  "invalid_context=%s", s);
2777 				kfree(s);
2778 			}
2779 			goto out_unlock;
2780 		}
2781 	}
2782 
2783 	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2784 out_unlock:
2785 	read_unlock(&policy_rwlock);
2786 	context_destroy(&newcon);
2787 out:
2788 	return rc;
2789 }
2790 
2791 /**
2792  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2793  * @nlbl_sid: NetLabel SID
2794  * @nlbl_type: NetLabel labeling protocol type
2795  * @xfrm_sid: XFRM SID
2796  *
2797  * Description:
2798  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2799  * resolved into a single SID it is returned via @peer_sid and the function
2800  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2801  * returns a negative value.  A table summarizing the behavior is below:
2802  *
2803  *                                 | function return |      @sid
2804  *   ------------------------------+-----------------+-----------------
2805  *   no peer labels                |        0        |    SECSID_NULL
2806  *   single peer label             |        0        |    <peer_label>
2807  *   multiple, consistent labels   |        0        |    <peer_label>
2808  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2809  *
2810  */
2811 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2812 				 u32 xfrm_sid,
2813 				 u32 *peer_sid)
2814 {
2815 	int rc;
2816 	struct context *nlbl_ctx;
2817 	struct context *xfrm_ctx;
2818 
2819 	*peer_sid = SECSID_NULL;
2820 
2821 	/* handle the common (which also happens to be the set of easy) cases
2822 	 * right away, these two if statements catch everything involving a
2823 	 * single or absent peer SID/label */
2824 	if (xfrm_sid == SECSID_NULL) {
2825 		*peer_sid = nlbl_sid;
2826 		return 0;
2827 	}
2828 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2829 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2830 	 * is present */
2831 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2832 		*peer_sid = xfrm_sid;
2833 		return 0;
2834 	}
2835 
2836 	/* we don't need to check ss_initialized here since the only way both
2837 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2838 	 * security server was initialized and ss_initialized was true */
2839 	if (!policydb.mls_enabled)
2840 		return 0;
2841 
2842 	read_lock(&policy_rwlock);
2843 
2844 	rc = -EINVAL;
2845 	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2846 	if (!nlbl_ctx) {
2847 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2848 		       __func__, nlbl_sid);
2849 		goto out;
2850 	}
2851 	rc = -EINVAL;
2852 	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2853 	if (!xfrm_ctx) {
2854 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2855 		       __func__, xfrm_sid);
2856 		goto out;
2857 	}
2858 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2859 	if (rc)
2860 		goto out;
2861 
2862 	/* at present NetLabel SIDs/labels really only carry MLS
2863 	 * information so if the MLS portion of the NetLabel SID
2864 	 * matches the MLS portion of the labeled XFRM SID/label
2865 	 * then pass along the XFRM SID as it is the most
2866 	 * expressive */
2867 	*peer_sid = xfrm_sid;
2868 out:
2869 	read_unlock(&policy_rwlock);
2870 	return rc;
2871 }
2872 
2873 static int get_classes_callback(void *k, void *d, void *args)
2874 {
2875 	struct class_datum *datum = d;
2876 	char *name = k, **classes = args;
2877 	int value = datum->value - 1;
2878 
2879 	classes[value] = kstrdup(name, GFP_ATOMIC);
2880 	if (!classes[value])
2881 		return -ENOMEM;
2882 
2883 	return 0;
2884 }
2885 
2886 int security_get_classes(char ***classes, int *nclasses)
2887 {
2888 	int rc;
2889 
2890 	read_lock(&policy_rwlock);
2891 
2892 	rc = -ENOMEM;
2893 	*nclasses = policydb.p_classes.nprim;
2894 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2895 	if (!*classes)
2896 		goto out;
2897 
2898 	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2899 			*classes);
2900 	if (rc) {
2901 		int i;
2902 		for (i = 0; i < *nclasses; i++)
2903 			kfree((*classes)[i]);
2904 		kfree(*classes);
2905 	}
2906 
2907 out:
2908 	read_unlock(&policy_rwlock);
2909 	return rc;
2910 }
2911 
2912 static int get_permissions_callback(void *k, void *d, void *args)
2913 {
2914 	struct perm_datum *datum = d;
2915 	char *name = k, **perms = args;
2916 	int value = datum->value - 1;
2917 
2918 	perms[value] = kstrdup(name, GFP_ATOMIC);
2919 	if (!perms[value])
2920 		return -ENOMEM;
2921 
2922 	return 0;
2923 }
2924 
2925 int security_get_permissions(char *class, char ***perms, int *nperms)
2926 {
2927 	int rc, i;
2928 	struct class_datum *match;
2929 
2930 	read_lock(&policy_rwlock);
2931 
2932 	rc = -EINVAL;
2933 	match = hashtab_search(policydb.p_classes.table, class);
2934 	if (!match) {
2935 		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2936 			__func__, class);
2937 		goto out;
2938 	}
2939 
2940 	rc = -ENOMEM;
2941 	*nperms = match->permissions.nprim;
2942 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2943 	if (!*perms)
2944 		goto out;
2945 
2946 	if (match->comdatum) {
2947 		rc = hashtab_map(match->comdatum->permissions.table,
2948 				get_permissions_callback, *perms);
2949 		if (rc)
2950 			goto err;
2951 	}
2952 
2953 	rc = hashtab_map(match->permissions.table, get_permissions_callback,
2954 			*perms);
2955 	if (rc)
2956 		goto err;
2957 
2958 out:
2959 	read_unlock(&policy_rwlock);
2960 	return rc;
2961 
2962 err:
2963 	read_unlock(&policy_rwlock);
2964 	for (i = 0; i < *nperms; i++)
2965 		kfree((*perms)[i]);
2966 	kfree(*perms);
2967 	return rc;
2968 }
2969 
2970 int security_get_reject_unknown(void)
2971 {
2972 	return policydb.reject_unknown;
2973 }
2974 
2975 int security_get_allow_unknown(void)
2976 {
2977 	return policydb.allow_unknown;
2978 }
2979 
2980 /**
2981  * security_policycap_supported - Check for a specific policy capability
2982  * @req_cap: capability
2983  *
2984  * Description:
2985  * This function queries the currently loaded policy to see if it supports the
2986  * capability specified by @req_cap.  Returns true (1) if the capability is
2987  * supported, false (0) if it isn't supported.
2988  *
2989  */
2990 int security_policycap_supported(unsigned int req_cap)
2991 {
2992 	int rc;
2993 
2994 	read_lock(&policy_rwlock);
2995 	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2996 	read_unlock(&policy_rwlock);
2997 
2998 	return rc;
2999 }
3000 
3001 struct selinux_audit_rule {
3002 	u32 au_seqno;
3003 	struct context au_ctxt;
3004 };
3005 
3006 void selinux_audit_rule_free(void *vrule)
3007 {
3008 	struct selinux_audit_rule *rule = vrule;
3009 
3010 	if (rule) {
3011 		context_destroy(&rule->au_ctxt);
3012 		kfree(rule);
3013 	}
3014 }
3015 
3016 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3017 {
3018 	struct selinux_audit_rule *tmprule;
3019 	struct role_datum *roledatum;
3020 	struct type_datum *typedatum;
3021 	struct user_datum *userdatum;
3022 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3023 	int rc = 0;
3024 
3025 	*rule = NULL;
3026 
3027 	if (!ss_initialized)
3028 		return -EOPNOTSUPP;
3029 
3030 	switch (field) {
3031 	case AUDIT_SUBJ_USER:
3032 	case AUDIT_SUBJ_ROLE:
3033 	case AUDIT_SUBJ_TYPE:
3034 	case AUDIT_OBJ_USER:
3035 	case AUDIT_OBJ_ROLE:
3036 	case AUDIT_OBJ_TYPE:
3037 		/* only 'equals' and 'not equals' fit user, role, and type */
3038 		if (op != Audit_equal && op != Audit_not_equal)
3039 			return -EINVAL;
3040 		break;
3041 	case AUDIT_SUBJ_SEN:
3042 	case AUDIT_SUBJ_CLR:
3043 	case AUDIT_OBJ_LEV_LOW:
3044 	case AUDIT_OBJ_LEV_HIGH:
3045 		/* we do not allow a range, indicated by the presence of '-' */
3046 		if (strchr(rulestr, '-'))
3047 			return -EINVAL;
3048 		break;
3049 	default:
3050 		/* only the above fields are valid */
3051 		return -EINVAL;
3052 	}
3053 
3054 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3055 	if (!tmprule)
3056 		return -ENOMEM;
3057 
3058 	context_init(&tmprule->au_ctxt);
3059 
3060 	read_lock(&policy_rwlock);
3061 
3062 	tmprule->au_seqno = latest_granting;
3063 
3064 	switch (field) {
3065 	case AUDIT_SUBJ_USER:
3066 	case AUDIT_OBJ_USER:
3067 		rc = -EINVAL;
3068 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
3069 		if (!userdatum)
3070 			goto out;
3071 		tmprule->au_ctxt.user = userdatum->value;
3072 		break;
3073 	case AUDIT_SUBJ_ROLE:
3074 	case AUDIT_OBJ_ROLE:
3075 		rc = -EINVAL;
3076 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3077 		if (!roledatum)
3078 			goto out;
3079 		tmprule->au_ctxt.role = roledatum->value;
3080 		break;
3081 	case AUDIT_SUBJ_TYPE:
3082 	case AUDIT_OBJ_TYPE:
3083 		rc = -EINVAL;
3084 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
3085 		if (!typedatum)
3086 			goto out;
3087 		tmprule->au_ctxt.type = typedatum->value;
3088 		break;
3089 	case AUDIT_SUBJ_SEN:
3090 	case AUDIT_SUBJ_CLR:
3091 	case AUDIT_OBJ_LEV_LOW:
3092 	case AUDIT_OBJ_LEV_HIGH:
3093 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3094 		if (rc)
3095 			goto out;
3096 		break;
3097 	}
3098 	rc = 0;
3099 out:
3100 	read_unlock(&policy_rwlock);
3101 
3102 	if (rc) {
3103 		selinux_audit_rule_free(tmprule);
3104 		tmprule = NULL;
3105 	}
3106 
3107 	*rule = tmprule;
3108 
3109 	return rc;
3110 }
3111 
3112 /* Check to see if the rule contains any selinux fields */
3113 int selinux_audit_rule_known(struct audit_krule *rule)
3114 {
3115 	int i;
3116 
3117 	for (i = 0; i < rule->field_count; i++) {
3118 		struct audit_field *f = &rule->fields[i];
3119 		switch (f->type) {
3120 		case AUDIT_SUBJ_USER:
3121 		case AUDIT_SUBJ_ROLE:
3122 		case AUDIT_SUBJ_TYPE:
3123 		case AUDIT_SUBJ_SEN:
3124 		case AUDIT_SUBJ_CLR:
3125 		case AUDIT_OBJ_USER:
3126 		case AUDIT_OBJ_ROLE:
3127 		case AUDIT_OBJ_TYPE:
3128 		case AUDIT_OBJ_LEV_LOW:
3129 		case AUDIT_OBJ_LEV_HIGH:
3130 			return 1;
3131 		}
3132 	}
3133 
3134 	return 0;
3135 }
3136 
3137 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3138 			     struct audit_context *actx)
3139 {
3140 	struct context *ctxt;
3141 	struct mls_level *level;
3142 	struct selinux_audit_rule *rule = vrule;
3143 	int match = 0;
3144 
3145 	if (unlikely(!rule)) {
3146 		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3147 		return -ENOENT;
3148 	}
3149 
3150 	read_lock(&policy_rwlock);
3151 
3152 	if (rule->au_seqno < latest_granting) {
3153 		match = -ESTALE;
3154 		goto out;
3155 	}
3156 
3157 	ctxt = sidtab_search(&sidtab, sid);
3158 	if (unlikely(!ctxt)) {
3159 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3160 			  sid);
3161 		match = -ENOENT;
3162 		goto out;
3163 	}
3164 
3165 	/* a field/op pair that is not caught here will simply fall through
3166 	   without a match */
3167 	switch (field) {
3168 	case AUDIT_SUBJ_USER:
3169 	case AUDIT_OBJ_USER:
3170 		switch (op) {
3171 		case Audit_equal:
3172 			match = (ctxt->user == rule->au_ctxt.user);
3173 			break;
3174 		case Audit_not_equal:
3175 			match = (ctxt->user != rule->au_ctxt.user);
3176 			break;
3177 		}
3178 		break;
3179 	case AUDIT_SUBJ_ROLE:
3180 	case AUDIT_OBJ_ROLE:
3181 		switch (op) {
3182 		case Audit_equal:
3183 			match = (ctxt->role == rule->au_ctxt.role);
3184 			break;
3185 		case Audit_not_equal:
3186 			match = (ctxt->role != rule->au_ctxt.role);
3187 			break;
3188 		}
3189 		break;
3190 	case AUDIT_SUBJ_TYPE:
3191 	case AUDIT_OBJ_TYPE:
3192 		switch (op) {
3193 		case Audit_equal:
3194 			match = (ctxt->type == rule->au_ctxt.type);
3195 			break;
3196 		case Audit_not_equal:
3197 			match = (ctxt->type != rule->au_ctxt.type);
3198 			break;
3199 		}
3200 		break;
3201 	case AUDIT_SUBJ_SEN:
3202 	case AUDIT_SUBJ_CLR:
3203 	case AUDIT_OBJ_LEV_LOW:
3204 	case AUDIT_OBJ_LEV_HIGH:
3205 		level = ((field == AUDIT_SUBJ_SEN ||
3206 			  field == AUDIT_OBJ_LEV_LOW) ?
3207 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3208 		switch (op) {
3209 		case Audit_equal:
3210 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3211 					     level);
3212 			break;
3213 		case Audit_not_equal:
3214 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3215 					      level);
3216 			break;
3217 		case Audit_lt:
3218 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3219 					       level) &&
3220 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3221 					       level));
3222 			break;
3223 		case Audit_le:
3224 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3225 					      level);
3226 			break;
3227 		case Audit_gt:
3228 			match = (mls_level_dom(level,
3229 					      &rule->au_ctxt.range.level[0]) &&
3230 				 !mls_level_eq(level,
3231 					       &rule->au_ctxt.range.level[0]));
3232 			break;
3233 		case Audit_ge:
3234 			match = mls_level_dom(level,
3235 					      &rule->au_ctxt.range.level[0]);
3236 			break;
3237 		}
3238 	}
3239 
3240 out:
3241 	read_unlock(&policy_rwlock);
3242 	return match;
3243 }
3244 
3245 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3246 
3247 static int aurule_avc_callback(u32 event)
3248 {
3249 	int err = 0;
3250 
3251 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3252 		err = aurule_callback();
3253 	return err;
3254 }
3255 
3256 static int __init aurule_init(void)
3257 {
3258 	int err;
3259 
3260 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3261 	if (err)
3262 		panic("avc_add_callback() failed, error %d\n", err);
3263 
3264 	return err;
3265 }
3266 __initcall(aurule_init);
3267 
3268 #ifdef CONFIG_NETLABEL
3269 /**
3270  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3271  * @secattr: the NetLabel packet security attributes
3272  * @sid: the SELinux SID
3273  *
3274  * Description:
3275  * Attempt to cache the context in @ctx, which was derived from the packet in
3276  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3277  * already been initialized.
3278  *
3279  */
3280 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3281 				      u32 sid)
3282 {
3283 	u32 *sid_cache;
3284 
3285 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3286 	if (sid_cache == NULL)
3287 		return;
3288 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3289 	if (secattr->cache == NULL) {
3290 		kfree(sid_cache);
3291 		return;
3292 	}
3293 
3294 	*sid_cache = sid;
3295 	secattr->cache->free = kfree;
3296 	secattr->cache->data = sid_cache;
3297 	secattr->flags |= NETLBL_SECATTR_CACHE;
3298 }
3299 
3300 /**
3301  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3302  * @secattr: the NetLabel packet security attributes
3303  * @sid: the SELinux SID
3304  *
3305  * Description:
3306  * Convert the given NetLabel security attributes in @secattr into a
3307  * SELinux SID.  If the @secattr field does not contain a full SELinux
3308  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3309  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3310  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3311  * conversion for future lookups.  Returns zero on success, negative values on
3312  * failure.
3313  *
3314  */
3315 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3316 				   u32 *sid)
3317 {
3318 	int rc;
3319 	struct context *ctx;
3320 	struct context ctx_new;
3321 
3322 	if (!ss_initialized) {
3323 		*sid = SECSID_NULL;
3324 		return 0;
3325 	}
3326 
3327 	read_lock(&policy_rwlock);
3328 
3329 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3330 		*sid = *(u32 *)secattr->cache->data;
3331 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3332 		*sid = secattr->attr.secid;
3333 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3334 		rc = -EIDRM;
3335 		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3336 		if (ctx == NULL)
3337 			goto out;
3338 
3339 		context_init(&ctx_new);
3340 		ctx_new.user = ctx->user;
3341 		ctx_new.role = ctx->role;
3342 		ctx_new.type = ctx->type;
3343 		mls_import_netlbl_lvl(&ctx_new, secattr);
3344 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3345 			rc = mls_import_netlbl_cat(&ctx_new, secattr);
3346 			if (rc)
3347 				goto out;
3348 		}
3349 		rc = -EIDRM;
3350 		if (!mls_context_isvalid(&policydb, &ctx_new))
3351 			goto out_free;
3352 
3353 		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3354 		if (rc)
3355 			goto out_free;
3356 
3357 		security_netlbl_cache_add(secattr, *sid);
3358 
3359 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3360 	} else
3361 		*sid = SECSID_NULL;
3362 
3363 	read_unlock(&policy_rwlock);
3364 	return 0;
3365 out_free:
3366 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3367 out:
3368 	read_unlock(&policy_rwlock);
3369 	return rc;
3370 }
3371 
3372 /**
3373  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3374  * @sid: the SELinux SID
3375  * @secattr: the NetLabel packet security attributes
3376  *
3377  * Description:
3378  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3379  * Returns zero on success, negative values on failure.
3380  *
3381  */
3382 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3383 {
3384 	int rc;
3385 	struct context *ctx;
3386 
3387 	if (!ss_initialized)
3388 		return 0;
3389 
3390 	read_lock(&policy_rwlock);
3391 
3392 	rc = -ENOENT;
3393 	ctx = sidtab_search(&sidtab, sid);
3394 	if (ctx == NULL)
3395 		goto out;
3396 
3397 	rc = -ENOMEM;
3398 	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3399 				  GFP_ATOMIC);
3400 	if (secattr->domain == NULL)
3401 		goto out;
3402 
3403 	secattr->attr.secid = sid;
3404 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3405 	mls_export_netlbl_lvl(ctx, secattr);
3406 	rc = mls_export_netlbl_cat(ctx, secattr);
3407 out:
3408 	read_unlock(&policy_rwlock);
3409 	return rc;
3410 }
3411 #endif /* CONFIG_NETLABEL */
3412 
3413 /**
3414  * security_read_policy - read the policy.
3415  * @data: binary policy data
3416  * @len: length of data in bytes
3417  *
3418  */
3419 int security_read_policy(void **data, size_t *len)
3420 {
3421 	int rc;
3422 	struct policy_file fp;
3423 
3424 	if (!ss_initialized)
3425 		return -EINVAL;
3426 
3427 	*len = security_policydb_len();
3428 
3429 	*data = vmalloc_user(*len);
3430 	if (!*data)
3431 		return -ENOMEM;
3432 
3433 	fp.data = *data;
3434 	fp.len = *len;
3435 
3436 	read_lock(&policy_rwlock);
3437 	rc = policydb_write(&policydb, &fp);
3438 	read_unlock(&policy_rwlock);
3439 
3440 	if (rc)
3441 		return rc;
3442 
3443 	*len = (unsigned long)fp.data - (unsigned long)*data;
3444 	return 0;
3445 
3446 }
3447