xref: /openbmc/linux/security/selinux/ss/services.c (revision d236d361)
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_extsockclass;
76 int selinux_policycap_alwaysnetwork;
77 int selinux_policycap_cgroupseclabel;
78 
79 static DEFINE_RWLOCK(policy_rwlock);
80 
81 static struct sidtab sidtab;
82 struct policydb policydb;
83 int ss_initialized;
84 
85 /*
86  * The largest sequence number that has been used when
87  * providing an access decision to the access vector cache.
88  * The sequence number only changes when a policy change
89  * occurs.
90  */
91 static u32 latest_granting;
92 
93 /* Forward declaration. */
94 static int context_struct_to_string(struct context *context, char **scontext,
95 				    u32 *scontext_len);
96 
97 static void context_struct_compute_av(struct context *scontext,
98 					struct context *tcontext,
99 					u16 tclass,
100 					struct av_decision *avd,
101 					struct extended_perms *xperms);
102 
103 struct selinux_mapping {
104 	u16 value; /* policy value */
105 	unsigned num_perms;
106 	u32 perms[sizeof(u32) * 8];
107 };
108 
109 static struct selinux_mapping *current_mapping;
110 static u16 current_mapping_size;
111 
112 static int selinux_set_mapping(struct policydb *pol,
113 			       struct security_class_mapping *map,
114 			       struct selinux_mapping **out_map_p,
115 			       u16 *out_map_size)
116 {
117 	struct selinux_mapping *out_map = NULL;
118 	size_t size = sizeof(struct selinux_mapping);
119 	u16 i, j;
120 	unsigned k;
121 	bool print_unknown_handle = false;
122 
123 	/* Find number of classes in the input mapping */
124 	if (!map)
125 		return -EINVAL;
126 	i = 0;
127 	while (map[i].name)
128 		i++;
129 
130 	/* Allocate space for the class records, plus one for class zero */
131 	out_map = kcalloc(++i, size, GFP_ATOMIC);
132 	if (!out_map)
133 		return -ENOMEM;
134 
135 	/* Store the raw class and permission values */
136 	j = 0;
137 	while (map[j].name) {
138 		struct security_class_mapping *p_in = map + (j++);
139 		struct selinux_mapping *p_out = out_map + j;
140 
141 		/* An empty class string skips ahead */
142 		if (!strcmp(p_in->name, "")) {
143 			p_out->num_perms = 0;
144 			continue;
145 		}
146 
147 		p_out->value = string_to_security_class(pol, p_in->name);
148 		if (!p_out->value) {
149 			printk(KERN_INFO
150 			       "SELinux:  Class %s not defined in policy.\n",
151 			       p_in->name);
152 			if (pol->reject_unknown)
153 				goto err;
154 			p_out->num_perms = 0;
155 			print_unknown_handle = true;
156 			continue;
157 		}
158 
159 		k = 0;
160 		while (p_in->perms[k]) {
161 			/* An empty permission string skips ahead */
162 			if (!*p_in->perms[k]) {
163 				k++;
164 				continue;
165 			}
166 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
167 							    p_in->perms[k]);
168 			if (!p_out->perms[k]) {
169 				printk(KERN_INFO
170 				       "SELinux:  Permission %s in class %s not defined in policy.\n",
171 				       p_in->perms[k], p_in->name);
172 				if (pol->reject_unknown)
173 					goto err;
174 				print_unknown_handle = true;
175 			}
176 
177 			k++;
178 		}
179 		p_out->num_perms = k;
180 	}
181 
182 	if (print_unknown_handle)
183 		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
184 		       pol->allow_unknown ? "allowed" : "denied");
185 
186 	*out_map_p = out_map;
187 	*out_map_size = i;
188 	return 0;
189 err:
190 	kfree(out_map);
191 	return -EINVAL;
192 }
193 
194 /*
195  * Get real, policy values from mapped values
196  */
197 
198 static u16 unmap_class(u16 tclass)
199 {
200 	if (tclass < current_mapping_size)
201 		return current_mapping[tclass].value;
202 
203 	return tclass;
204 }
205 
206 /*
207  * Get kernel value for class from its policy value
208  */
209 static u16 map_class(u16 pol_value)
210 {
211 	u16 i;
212 
213 	for (i = 1; i < current_mapping_size; i++) {
214 		if (current_mapping[i].value == pol_value)
215 			return i;
216 	}
217 
218 	return SECCLASS_NULL;
219 }
220 
221 static void map_decision(u16 tclass, struct av_decision *avd,
222 			 int allow_unknown)
223 {
224 	if (tclass < current_mapping_size) {
225 		unsigned i, n = current_mapping[tclass].num_perms;
226 		u32 result;
227 
228 		for (i = 0, result = 0; i < n; i++) {
229 			if (avd->allowed & current_mapping[tclass].perms[i])
230 				result |= 1<<i;
231 			if (allow_unknown && !current_mapping[tclass].perms[i])
232 				result |= 1<<i;
233 		}
234 		avd->allowed = result;
235 
236 		for (i = 0, result = 0; i < n; i++)
237 			if (avd->auditallow & current_mapping[tclass].perms[i])
238 				result |= 1<<i;
239 		avd->auditallow = result;
240 
241 		for (i = 0, result = 0; i < n; i++) {
242 			if (avd->auditdeny & current_mapping[tclass].perms[i])
243 				result |= 1<<i;
244 			if (!allow_unknown && !current_mapping[tclass].perms[i])
245 				result |= 1<<i;
246 		}
247 		/*
248 		 * In case the kernel has a bug and requests a permission
249 		 * between num_perms and the maximum permission number, we
250 		 * should audit that denial
251 		 */
252 		for (; i < (sizeof(u32)*8); i++)
253 			result |= 1<<i;
254 		avd->auditdeny = result;
255 	}
256 }
257 
258 int security_mls_enabled(void)
259 {
260 	return policydb.mls_enabled;
261 }
262 
263 /*
264  * Return the boolean value of a constraint expression
265  * when it is applied to the specified source and target
266  * security contexts.
267  *
268  * xcontext is a special beast...  It is used by the validatetrans rules
269  * only.  For these rules, scontext is the context before the transition,
270  * tcontext is the context after the transition, and xcontext is the context
271  * of the process performing the transition.  All other callers of
272  * constraint_expr_eval should pass in NULL for xcontext.
273  */
274 static int constraint_expr_eval(struct context *scontext,
275 				struct context *tcontext,
276 				struct context *xcontext,
277 				struct constraint_expr *cexpr)
278 {
279 	u32 val1, val2;
280 	struct context *c;
281 	struct role_datum *r1, *r2;
282 	struct mls_level *l1, *l2;
283 	struct constraint_expr *e;
284 	int s[CEXPR_MAXDEPTH];
285 	int sp = -1;
286 
287 	for (e = cexpr; e; e = e->next) {
288 		switch (e->expr_type) {
289 		case CEXPR_NOT:
290 			BUG_ON(sp < 0);
291 			s[sp] = !s[sp];
292 			break;
293 		case CEXPR_AND:
294 			BUG_ON(sp < 1);
295 			sp--;
296 			s[sp] &= s[sp + 1];
297 			break;
298 		case CEXPR_OR:
299 			BUG_ON(sp < 1);
300 			sp--;
301 			s[sp] |= s[sp + 1];
302 			break;
303 		case CEXPR_ATTR:
304 			if (sp == (CEXPR_MAXDEPTH - 1))
305 				return 0;
306 			switch (e->attr) {
307 			case CEXPR_USER:
308 				val1 = scontext->user;
309 				val2 = tcontext->user;
310 				break;
311 			case CEXPR_TYPE:
312 				val1 = scontext->type;
313 				val2 = tcontext->type;
314 				break;
315 			case CEXPR_ROLE:
316 				val1 = scontext->role;
317 				val2 = tcontext->role;
318 				r1 = policydb.role_val_to_struct[val1 - 1];
319 				r2 = policydb.role_val_to_struct[val2 - 1];
320 				switch (e->op) {
321 				case CEXPR_DOM:
322 					s[++sp] = ebitmap_get_bit(&r1->dominates,
323 								  val2 - 1);
324 					continue;
325 				case CEXPR_DOMBY:
326 					s[++sp] = ebitmap_get_bit(&r2->dominates,
327 								  val1 - 1);
328 					continue;
329 				case CEXPR_INCOMP:
330 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
331 								    val2 - 1) &&
332 						   !ebitmap_get_bit(&r2->dominates,
333 								    val1 - 1));
334 					continue;
335 				default:
336 					break;
337 				}
338 				break;
339 			case CEXPR_L1L2:
340 				l1 = &(scontext->range.level[0]);
341 				l2 = &(tcontext->range.level[0]);
342 				goto mls_ops;
343 			case CEXPR_L1H2:
344 				l1 = &(scontext->range.level[0]);
345 				l2 = &(tcontext->range.level[1]);
346 				goto mls_ops;
347 			case CEXPR_H1L2:
348 				l1 = &(scontext->range.level[1]);
349 				l2 = &(tcontext->range.level[0]);
350 				goto mls_ops;
351 			case CEXPR_H1H2:
352 				l1 = &(scontext->range.level[1]);
353 				l2 = &(tcontext->range.level[1]);
354 				goto mls_ops;
355 			case CEXPR_L1H1:
356 				l1 = &(scontext->range.level[0]);
357 				l2 = &(scontext->range.level[1]);
358 				goto mls_ops;
359 			case CEXPR_L2H2:
360 				l1 = &(tcontext->range.level[0]);
361 				l2 = &(tcontext->range.level[1]);
362 				goto mls_ops;
363 mls_ops:
364 			switch (e->op) {
365 			case CEXPR_EQ:
366 				s[++sp] = mls_level_eq(l1, l2);
367 				continue;
368 			case CEXPR_NEQ:
369 				s[++sp] = !mls_level_eq(l1, l2);
370 				continue;
371 			case CEXPR_DOM:
372 				s[++sp] = mls_level_dom(l1, l2);
373 				continue;
374 			case CEXPR_DOMBY:
375 				s[++sp] = mls_level_dom(l2, l1);
376 				continue;
377 			case CEXPR_INCOMP:
378 				s[++sp] = mls_level_incomp(l2, l1);
379 				continue;
380 			default:
381 				BUG();
382 				return 0;
383 			}
384 			break;
385 			default:
386 				BUG();
387 				return 0;
388 			}
389 
390 			switch (e->op) {
391 			case CEXPR_EQ:
392 				s[++sp] = (val1 == val2);
393 				break;
394 			case CEXPR_NEQ:
395 				s[++sp] = (val1 != val2);
396 				break;
397 			default:
398 				BUG();
399 				return 0;
400 			}
401 			break;
402 		case CEXPR_NAMES:
403 			if (sp == (CEXPR_MAXDEPTH-1))
404 				return 0;
405 			c = scontext;
406 			if (e->attr & CEXPR_TARGET)
407 				c = tcontext;
408 			else if (e->attr & CEXPR_XTARGET) {
409 				c = xcontext;
410 				if (!c) {
411 					BUG();
412 					return 0;
413 				}
414 			}
415 			if (e->attr & CEXPR_USER)
416 				val1 = c->user;
417 			else if (e->attr & CEXPR_ROLE)
418 				val1 = c->role;
419 			else if (e->attr & CEXPR_TYPE)
420 				val1 = c->type;
421 			else {
422 				BUG();
423 				return 0;
424 			}
425 
426 			switch (e->op) {
427 			case CEXPR_EQ:
428 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
429 				break;
430 			case CEXPR_NEQ:
431 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
432 				break;
433 			default:
434 				BUG();
435 				return 0;
436 			}
437 			break;
438 		default:
439 			BUG();
440 			return 0;
441 		}
442 	}
443 
444 	BUG_ON(sp != 0);
445 	return s[0];
446 }
447 
448 /*
449  * security_dump_masked_av - dumps masked permissions during
450  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
451  */
452 static int dump_masked_av_helper(void *k, void *d, void *args)
453 {
454 	struct perm_datum *pdatum = d;
455 	char **permission_names = args;
456 
457 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
458 
459 	permission_names[pdatum->value - 1] = (char *)k;
460 
461 	return 0;
462 }
463 
464 static void security_dump_masked_av(struct context *scontext,
465 				    struct context *tcontext,
466 				    u16 tclass,
467 				    u32 permissions,
468 				    const char *reason)
469 {
470 	struct common_datum *common_dat;
471 	struct class_datum *tclass_dat;
472 	struct audit_buffer *ab;
473 	char *tclass_name;
474 	char *scontext_name = NULL;
475 	char *tcontext_name = NULL;
476 	char *permission_names[32];
477 	int index;
478 	u32 length;
479 	bool need_comma = false;
480 
481 	if (!permissions)
482 		return;
483 
484 	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
485 	tclass_dat = policydb.class_val_to_struct[tclass - 1];
486 	common_dat = tclass_dat->comdatum;
487 
488 	/* init permission_names */
489 	if (common_dat &&
490 	    hashtab_map(common_dat->permissions.table,
491 			dump_masked_av_helper, permission_names) < 0)
492 		goto out;
493 
494 	if (hashtab_map(tclass_dat->permissions.table,
495 			dump_masked_av_helper, permission_names) < 0)
496 		goto out;
497 
498 	/* get scontext/tcontext in text form */
499 	if (context_struct_to_string(scontext,
500 				     &scontext_name, &length) < 0)
501 		goto out;
502 
503 	if (context_struct_to_string(tcontext,
504 				     &tcontext_name, &length) < 0)
505 		goto out;
506 
507 	/* audit a message */
508 	ab = audit_log_start(current->audit_context,
509 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
510 	if (!ab)
511 		goto out;
512 
513 	audit_log_format(ab, "op=security_compute_av reason=%s "
514 			 "scontext=%s tcontext=%s tclass=%s perms=",
515 			 reason, scontext_name, tcontext_name, tclass_name);
516 
517 	for (index = 0; index < 32; index++) {
518 		u32 mask = (1 << index);
519 
520 		if ((mask & permissions) == 0)
521 			continue;
522 
523 		audit_log_format(ab, "%s%s",
524 				 need_comma ? "," : "",
525 				 permission_names[index]
526 				 ? permission_names[index] : "????");
527 		need_comma = true;
528 	}
529 	audit_log_end(ab);
530 out:
531 	/* release scontext/tcontext */
532 	kfree(tcontext_name);
533 	kfree(scontext_name);
534 
535 	return;
536 }
537 
538 /*
539  * security_boundary_permission - drops violated permissions
540  * on boundary constraint.
541  */
542 static void type_attribute_bounds_av(struct context *scontext,
543 				     struct context *tcontext,
544 				     u16 tclass,
545 				     struct av_decision *avd)
546 {
547 	struct context lo_scontext;
548 	struct context lo_tcontext, *tcontextp = tcontext;
549 	struct av_decision lo_avd;
550 	struct type_datum *source;
551 	struct type_datum *target;
552 	u32 masked = 0;
553 
554 	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
555 				    scontext->type - 1);
556 	BUG_ON(!source);
557 
558 	if (!source->bounds)
559 		return;
560 
561 	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
562 				    tcontext->type - 1);
563 	BUG_ON(!target);
564 
565 	memset(&lo_avd, 0, sizeof(lo_avd));
566 
567 	memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
568 	lo_scontext.type = source->bounds;
569 
570 	if (target->bounds) {
571 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
572 		lo_tcontext.type = target->bounds;
573 		tcontextp = &lo_tcontext;
574 	}
575 
576 	context_struct_compute_av(&lo_scontext,
577 				  tcontextp,
578 				  tclass,
579 				  &lo_avd,
580 				  NULL);
581 
582 	masked = ~lo_avd.allowed & avd->allowed;
583 
584 	if (likely(!masked))
585 		return;		/* no masked permission */
586 
587 	/* mask violated permissions */
588 	avd->allowed &= ~masked;
589 
590 	/* audit masked permissions */
591 	security_dump_masked_av(scontext, tcontext,
592 				tclass, masked, "bounds");
593 }
594 
595 /*
596  * flag which drivers have permissions
597  * only looking for ioctl based extended permssions
598  */
599 void services_compute_xperms_drivers(
600 		struct extended_perms *xperms,
601 		struct avtab_node *node)
602 {
603 	unsigned int i;
604 
605 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
606 		/* if one or more driver has all permissions allowed */
607 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
608 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
609 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
610 		/* if allowing permissions within a driver */
611 		security_xperm_set(xperms->drivers.p,
612 					node->datum.u.xperms->driver);
613 	}
614 
615 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
616 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
617 		xperms->len = 1;
618 }
619 
620 /*
621  * Compute access vectors and extended permissions based on a context
622  * structure pair for the permissions in a particular class.
623  */
624 static void context_struct_compute_av(struct context *scontext,
625 					struct context *tcontext,
626 					u16 tclass,
627 					struct av_decision *avd,
628 					struct extended_perms *xperms)
629 {
630 	struct constraint_node *constraint;
631 	struct role_allow *ra;
632 	struct avtab_key avkey;
633 	struct avtab_node *node;
634 	struct class_datum *tclass_datum;
635 	struct ebitmap *sattr, *tattr;
636 	struct ebitmap_node *snode, *tnode;
637 	unsigned int i, j;
638 
639 	avd->allowed = 0;
640 	avd->auditallow = 0;
641 	avd->auditdeny = 0xffffffff;
642 	if (xperms) {
643 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
644 		xperms->len = 0;
645 	}
646 
647 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
648 		if (printk_ratelimit())
649 			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
650 		return;
651 	}
652 
653 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
654 
655 	/*
656 	 * If a specific type enforcement rule was defined for
657 	 * this permission check, then use it.
658 	 */
659 	avkey.target_class = tclass;
660 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
661 	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
662 	BUG_ON(!sattr);
663 	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
664 	BUG_ON(!tattr);
665 	ebitmap_for_each_positive_bit(sattr, snode, i) {
666 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
667 			avkey.source_type = i + 1;
668 			avkey.target_type = j + 1;
669 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
670 			     node;
671 			     node = avtab_search_node_next(node, avkey.specified)) {
672 				if (node->key.specified == AVTAB_ALLOWED)
673 					avd->allowed |= node->datum.u.data;
674 				else if (node->key.specified == AVTAB_AUDITALLOW)
675 					avd->auditallow |= node->datum.u.data;
676 				else if (node->key.specified == AVTAB_AUDITDENY)
677 					avd->auditdeny &= node->datum.u.data;
678 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
679 					services_compute_xperms_drivers(xperms, node);
680 			}
681 
682 			/* Check conditional av table for additional permissions */
683 			cond_compute_av(&policydb.te_cond_avtab, &avkey,
684 					avd, xperms);
685 
686 		}
687 	}
688 
689 	/*
690 	 * Remove any permissions prohibited by a constraint (this includes
691 	 * the MLS policy).
692 	 */
693 	constraint = tclass_datum->constraints;
694 	while (constraint) {
695 		if ((constraint->permissions & (avd->allowed)) &&
696 		    !constraint_expr_eval(scontext, tcontext, NULL,
697 					  constraint->expr)) {
698 			avd->allowed &= ~(constraint->permissions);
699 		}
700 		constraint = constraint->next;
701 	}
702 
703 	/*
704 	 * If checking process transition permission and the
705 	 * role is changing, then check the (current_role, new_role)
706 	 * pair.
707 	 */
708 	if (tclass == policydb.process_class &&
709 	    (avd->allowed & policydb.process_trans_perms) &&
710 	    scontext->role != tcontext->role) {
711 		for (ra = policydb.role_allow; ra; ra = ra->next) {
712 			if (scontext->role == ra->role &&
713 			    tcontext->role == ra->new_role)
714 				break;
715 		}
716 		if (!ra)
717 			avd->allowed &= ~policydb.process_trans_perms;
718 	}
719 
720 	/*
721 	 * If the given source and target types have boundary
722 	 * constraint, lazy checks have to mask any violated
723 	 * permission and notice it to userspace via audit.
724 	 */
725 	type_attribute_bounds_av(scontext, tcontext,
726 				 tclass, avd);
727 }
728 
729 static int security_validtrans_handle_fail(struct context *ocontext,
730 					   struct context *ncontext,
731 					   struct context *tcontext,
732 					   u16 tclass)
733 {
734 	char *o = NULL, *n = NULL, *t = NULL;
735 	u32 olen, nlen, tlen;
736 
737 	if (context_struct_to_string(ocontext, &o, &olen))
738 		goto out;
739 	if (context_struct_to_string(ncontext, &n, &nlen))
740 		goto out;
741 	if (context_struct_to_string(tcontext, &t, &tlen))
742 		goto out;
743 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
744 		  "op=security_validate_transition seresult=denied"
745 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
746 		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
747 out:
748 	kfree(o);
749 	kfree(n);
750 	kfree(t);
751 
752 	if (!selinux_enforcing)
753 		return 0;
754 	return -EPERM;
755 }
756 
757 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
758 					  u16 orig_tclass, bool user)
759 {
760 	struct context *ocontext;
761 	struct context *ncontext;
762 	struct context *tcontext;
763 	struct class_datum *tclass_datum;
764 	struct constraint_node *constraint;
765 	u16 tclass;
766 	int rc = 0;
767 
768 	if (!ss_initialized)
769 		return 0;
770 
771 	read_lock(&policy_rwlock);
772 
773 	if (!user)
774 		tclass = unmap_class(orig_tclass);
775 	else
776 		tclass = orig_tclass;
777 
778 	if (!tclass || tclass > policydb.p_classes.nprim) {
779 		rc = -EINVAL;
780 		goto out;
781 	}
782 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
783 
784 	ocontext = sidtab_search(&sidtab, oldsid);
785 	if (!ocontext) {
786 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
787 			__func__, oldsid);
788 		rc = -EINVAL;
789 		goto out;
790 	}
791 
792 	ncontext = sidtab_search(&sidtab, newsid);
793 	if (!ncontext) {
794 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
795 			__func__, newsid);
796 		rc = -EINVAL;
797 		goto out;
798 	}
799 
800 	tcontext = sidtab_search(&sidtab, tasksid);
801 	if (!tcontext) {
802 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
803 			__func__, tasksid);
804 		rc = -EINVAL;
805 		goto out;
806 	}
807 
808 	constraint = tclass_datum->validatetrans;
809 	while (constraint) {
810 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
811 					  constraint->expr)) {
812 			if (user)
813 				rc = -EPERM;
814 			else
815 				rc = security_validtrans_handle_fail(ocontext,
816 								     ncontext,
817 								     tcontext,
818 								     tclass);
819 			goto out;
820 		}
821 		constraint = constraint->next;
822 	}
823 
824 out:
825 	read_unlock(&policy_rwlock);
826 	return rc;
827 }
828 
829 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
830 					u16 tclass)
831 {
832 	return security_compute_validatetrans(oldsid, newsid, tasksid,
833 						tclass, true);
834 }
835 
836 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
837 				 u16 orig_tclass)
838 {
839 	return security_compute_validatetrans(oldsid, newsid, tasksid,
840 						orig_tclass, false);
841 }
842 
843 /*
844  * security_bounded_transition - check whether the given
845  * transition is directed to bounded, or not.
846  * It returns 0, if @newsid is bounded by @oldsid.
847  * Otherwise, it returns error code.
848  *
849  * @oldsid : current security identifier
850  * @newsid : destinated security identifier
851  */
852 int security_bounded_transition(u32 old_sid, u32 new_sid)
853 {
854 	struct context *old_context, *new_context;
855 	struct type_datum *type;
856 	int index;
857 	int rc;
858 
859 	read_lock(&policy_rwlock);
860 
861 	rc = -EINVAL;
862 	old_context = sidtab_search(&sidtab, old_sid);
863 	if (!old_context) {
864 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
865 		       __func__, old_sid);
866 		goto out;
867 	}
868 
869 	rc = -EINVAL;
870 	new_context = sidtab_search(&sidtab, new_sid);
871 	if (!new_context) {
872 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
873 		       __func__, new_sid);
874 		goto out;
875 	}
876 
877 	rc = 0;
878 	/* type/domain unchanged */
879 	if (old_context->type == new_context->type)
880 		goto out;
881 
882 	index = new_context->type;
883 	while (true) {
884 		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
885 					  index - 1);
886 		BUG_ON(!type);
887 
888 		/* not bounded anymore */
889 		rc = -EPERM;
890 		if (!type->bounds)
891 			break;
892 
893 		/* @newsid is bounded by @oldsid */
894 		rc = 0;
895 		if (type->bounds == old_context->type)
896 			break;
897 
898 		index = type->bounds;
899 	}
900 
901 	if (rc) {
902 		char *old_name = NULL;
903 		char *new_name = NULL;
904 		u32 length;
905 
906 		if (!context_struct_to_string(old_context,
907 					      &old_name, &length) &&
908 		    !context_struct_to_string(new_context,
909 					      &new_name, &length)) {
910 			audit_log(current->audit_context,
911 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
912 				  "op=security_bounded_transition "
913 				  "seresult=denied "
914 				  "oldcontext=%s newcontext=%s",
915 				  old_name, new_name);
916 		}
917 		kfree(new_name);
918 		kfree(old_name);
919 	}
920 out:
921 	read_unlock(&policy_rwlock);
922 
923 	return rc;
924 }
925 
926 static void avd_init(struct av_decision *avd)
927 {
928 	avd->allowed = 0;
929 	avd->auditallow = 0;
930 	avd->auditdeny = 0xffffffff;
931 	avd->seqno = latest_granting;
932 	avd->flags = 0;
933 }
934 
935 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
936 					struct avtab_node *node)
937 {
938 	unsigned int i;
939 
940 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
941 		if (xpermd->driver != node->datum.u.xperms->driver)
942 			return;
943 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
944 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
945 					xpermd->driver))
946 			return;
947 	} else {
948 		BUG();
949 	}
950 
951 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
952 		xpermd->used |= XPERMS_ALLOWED;
953 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
954 			memset(xpermd->allowed->p, 0xff,
955 					sizeof(xpermd->allowed->p));
956 		}
957 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
958 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
959 				xpermd->allowed->p[i] |=
960 					node->datum.u.xperms->perms.p[i];
961 		}
962 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
963 		xpermd->used |= XPERMS_AUDITALLOW;
964 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
965 			memset(xpermd->auditallow->p, 0xff,
966 					sizeof(xpermd->auditallow->p));
967 		}
968 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
969 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
970 				xpermd->auditallow->p[i] |=
971 					node->datum.u.xperms->perms.p[i];
972 		}
973 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
974 		xpermd->used |= XPERMS_DONTAUDIT;
975 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
976 			memset(xpermd->dontaudit->p, 0xff,
977 					sizeof(xpermd->dontaudit->p));
978 		}
979 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
980 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
981 				xpermd->dontaudit->p[i] |=
982 					node->datum.u.xperms->perms.p[i];
983 		}
984 	} else {
985 		BUG();
986 	}
987 }
988 
989 void security_compute_xperms_decision(u32 ssid,
990 				u32 tsid,
991 				u16 orig_tclass,
992 				u8 driver,
993 				struct extended_perms_decision *xpermd)
994 {
995 	u16 tclass;
996 	struct context *scontext, *tcontext;
997 	struct avtab_key avkey;
998 	struct avtab_node *node;
999 	struct ebitmap *sattr, *tattr;
1000 	struct ebitmap_node *snode, *tnode;
1001 	unsigned int i, j;
1002 
1003 	xpermd->driver = driver;
1004 	xpermd->used = 0;
1005 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1006 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1007 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1008 
1009 	read_lock(&policy_rwlock);
1010 	if (!ss_initialized)
1011 		goto allow;
1012 
1013 	scontext = sidtab_search(&sidtab, ssid);
1014 	if (!scontext) {
1015 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1016 		       __func__, ssid);
1017 		goto out;
1018 	}
1019 
1020 	tcontext = sidtab_search(&sidtab, tsid);
1021 	if (!tcontext) {
1022 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1023 		       __func__, tsid);
1024 		goto out;
1025 	}
1026 
1027 	tclass = unmap_class(orig_tclass);
1028 	if (unlikely(orig_tclass && !tclass)) {
1029 		if (policydb.allow_unknown)
1030 			goto allow;
1031 		goto out;
1032 	}
1033 
1034 
1035 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1036 		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1037 		goto out;
1038 	}
1039 
1040 	avkey.target_class = tclass;
1041 	avkey.specified = AVTAB_XPERMS;
1042 	sattr = flex_array_get(policydb.type_attr_map_array,
1043 				scontext->type - 1);
1044 	BUG_ON(!sattr);
1045 	tattr = flex_array_get(policydb.type_attr_map_array,
1046 				tcontext->type - 1);
1047 	BUG_ON(!tattr);
1048 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1049 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1050 			avkey.source_type = i + 1;
1051 			avkey.target_type = j + 1;
1052 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1053 			     node;
1054 			     node = avtab_search_node_next(node, avkey.specified))
1055 				services_compute_xperms_decision(xpermd, node);
1056 
1057 			cond_compute_xperms(&policydb.te_cond_avtab,
1058 						&avkey, xpermd);
1059 		}
1060 	}
1061 out:
1062 	read_unlock(&policy_rwlock);
1063 	return;
1064 allow:
1065 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1066 	goto out;
1067 }
1068 
1069 /**
1070  * security_compute_av - Compute access vector decisions.
1071  * @ssid: source security identifier
1072  * @tsid: target security identifier
1073  * @tclass: target security class
1074  * @avd: access vector decisions
1075  * @xperms: extended permissions
1076  *
1077  * Compute a set of access vector decisions based on the
1078  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1079  */
1080 void security_compute_av(u32 ssid,
1081 			 u32 tsid,
1082 			 u16 orig_tclass,
1083 			 struct av_decision *avd,
1084 			 struct extended_perms *xperms)
1085 {
1086 	u16 tclass;
1087 	struct context *scontext = NULL, *tcontext = NULL;
1088 
1089 	read_lock(&policy_rwlock);
1090 	avd_init(avd);
1091 	xperms->len = 0;
1092 	if (!ss_initialized)
1093 		goto allow;
1094 
1095 	scontext = sidtab_search(&sidtab, ssid);
1096 	if (!scontext) {
1097 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1098 		       __func__, ssid);
1099 		goto out;
1100 	}
1101 
1102 	/* permissive domain? */
1103 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1104 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1105 
1106 	tcontext = sidtab_search(&sidtab, tsid);
1107 	if (!tcontext) {
1108 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1109 		       __func__, tsid);
1110 		goto out;
1111 	}
1112 
1113 	tclass = unmap_class(orig_tclass);
1114 	if (unlikely(orig_tclass && !tclass)) {
1115 		if (policydb.allow_unknown)
1116 			goto allow;
1117 		goto out;
1118 	}
1119 	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1120 	map_decision(orig_tclass, avd, policydb.allow_unknown);
1121 out:
1122 	read_unlock(&policy_rwlock);
1123 	return;
1124 allow:
1125 	avd->allowed = 0xffffffff;
1126 	goto out;
1127 }
1128 
1129 void security_compute_av_user(u32 ssid,
1130 			      u32 tsid,
1131 			      u16 tclass,
1132 			      struct av_decision *avd)
1133 {
1134 	struct context *scontext = NULL, *tcontext = NULL;
1135 
1136 	read_lock(&policy_rwlock);
1137 	avd_init(avd);
1138 	if (!ss_initialized)
1139 		goto allow;
1140 
1141 	scontext = sidtab_search(&sidtab, ssid);
1142 	if (!scontext) {
1143 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1144 		       __func__, ssid);
1145 		goto out;
1146 	}
1147 
1148 	/* permissive domain? */
1149 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1150 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1151 
1152 	tcontext = sidtab_search(&sidtab, tsid);
1153 	if (!tcontext) {
1154 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1155 		       __func__, tsid);
1156 		goto out;
1157 	}
1158 
1159 	if (unlikely(!tclass)) {
1160 		if (policydb.allow_unknown)
1161 			goto allow;
1162 		goto out;
1163 	}
1164 
1165 	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1166  out:
1167 	read_unlock(&policy_rwlock);
1168 	return;
1169 allow:
1170 	avd->allowed = 0xffffffff;
1171 	goto out;
1172 }
1173 
1174 /*
1175  * Write the security context string representation of
1176  * the context structure `context' into a dynamically
1177  * allocated string of the correct size.  Set `*scontext'
1178  * to point to this string and set `*scontext_len' to
1179  * the length of the string.
1180  */
1181 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1182 {
1183 	char *scontextp;
1184 
1185 	if (scontext)
1186 		*scontext = NULL;
1187 	*scontext_len = 0;
1188 
1189 	if (context->len) {
1190 		*scontext_len = context->len;
1191 		if (scontext) {
1192 			*scontext = kstrdup(context->str, GFP_ATOMIC);
1193 			if (!(*scontext))
1194 				return -ENOMEM;
1195 		}
1196 		return 0;
1197 	}
1198 
1199 	/* Compute the size of the context. */
1200 	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1201 	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1202 	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1203 	*scontext_len += mls_compute_context_len(context);
1204 
1205 	if (!scontext)
1206 		return 0;
1207 
1208 	/* Allocate space for the context; caller must free this space. */
1209 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1210 	if (!scontextp)
1211 		return -ENOMEM;
1212 	*scontext = scontextp;
1213 
1214 	/*
1215 	 * Copy the user name, role name and type name into the context.
1216 	 */
1217 	scontextp += sprintf(scontextp, "%s:%s:%s",
1218 		sym_name(&policydb, SYM_USERS, context->user - 1),
1219 		sym_name(&policydb, SYM_ROLES, context->role - 1),
1220 		sym_name(&policydb, SYM_TYPES, context->type - 1));
1221 
1222 	mls_sid_to_context(context, &scontextp);
1223 
1224 	*scontextp = 0;
1225 
1226 	return 0;
1227 }
1228 
1229 #include "initial_sid_to_string.h"
1230 
1231 const char *security_get_initial_sid_context(u32 sid)
1232 {
1233 	if (unlikely(sid > SECINITSID_NUM))
1234 		return NULL;
1235 	return initial_sid_to_string[sid];
1236 }
1237 
1238 static int security_sid_to_context_core(u32 sid, char **scontext,
1239 					u32 *scontext_len, int force)
1240 {
1241 	struct context *context;
1242 	int rc = 0;
1243 
1244 	if (scontext)
1245 		*scontext = NULL;
1246 	*scontext_len  = 0;
1247 
1248 	if (!ss_initialized) {
1249 		if (sid <= SECINITSID_NUM) {
1250 			char *scontextp;
1251 
1252 			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1253 			if (!scontext)
1254 				goto out;
1255 			scontextp = kmemdup(initial_sid_to_string[sid],
1256 					    *scontext_len, GFP_ATOMIC);
1257 			if (!scontextp) {
1258 				rc = -ENOMEM;
1259 				goto out;
1260 			}
1261 			*scontext = scontextp;
1262 			goto out;
1263 		}
1264 		printk(KERN_ERR "SELinux: %s:  called before initial "
1265 		       "load_policy on unknown SID %d\n", __func__, sid);
1266 		rc = -EINVAL;
1267 		goto out;
1268 	}
1269 	read_lock(&policy_rwlock);
1270 	if (force)
1271 		context = sidtab_search_force(&sidtab, sid);
1272 	else
1273 		context = sidtab_search(&sidtab, sid);
1274 	if (!context) {
1275 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1276 			__func__, sid);
1277 		rc = -EINVAL;
1278 		goto out_unlock;
1279 	}
1280 	rc = context_struct_to_string(context, scontext, scontext_len);
1281 out_unlock:
1282 	read_unlock(&policy_rwlock);
1283 out:
1284 	return rc;
1285 
1286 }
1287 
1288 /**
1289  * security_sid_to_context - Obtain a context for a given SID.
1290  * @sid: security identifier, SID
1291  * @scontext: security context
1292  * @scontext_len: length in bytes
1293  *
1294  * Write the string representation of the context associated with @sid
1295  * into a dynamically allocated string of the correct size.  Set @scontext
1296  * to point to this string and set @scontext_len to the length of the string.
1297  */
1298 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1299 {
1300 	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1301 }
1302 
1303 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1304 {
1305 	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1306 }
1307 
1308 /*
1309  * Caveat:  Mutates scontext.
1310  */
1311 static int string_to_context_struct(struct policydb *pol,
1312 				    struct sidtab *sidtabp,
1313 				    char *scontext,
1314 				    u32 scontext_len,
1315 				    struct context *ctx,
1316 				    u32 def_sid)
1317 {
1318 	struct role_datum *role;
1319 	struct type_datum *typdatum;
1320 	struct user_datum *usrdatum;
1321 	char *scontextp, *p, oldc;
1322 	int rc = 0;
1323 
1324 	context_init(ctx);
1325 
1326 	/* Parse the security context. */
1327 
1328 	rc = -EINVAL;
1329 	scontextp = (char *) scontext;
1330 
1331 	/* Extract the user. */
1332 	p = scontextp;
1333 	while (*p && *p != ':')
1334 		p++;
1335 
1336 	if (*p == 0)
1337 		goto out;
1338 
1339 	*p++ = 0;
1340 
1341 	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1342 	if (!usrdatum)
1343 		goto out;
1344 
1345 	ctx->user = usrdatum->value;
1346 
1347 	/* Extract role. */
1348 	scontextp = p;
1349 	while (*p && *p != ':')
1350 		p++;
1351 
1352 	if (*p == 0)
1353 		goto out;
1354 
1355 	*p++ = 0;
1356 
1357 	role = hashtab_search(pol->p_roles.table, scontextp);
1358 	if (!role)
1359 		goto out;
1360 	ctx->role = role->value;
1361 
1362 	/* Extract type. */
1363 	scontextp = p;
1364 	while (*p && *p != ':')
1365 		p++;
1366 	oldc = *p;
1367 	*p++ = 0;
1368 
1369 	typdatum = hashtab_search(pol->p_types.table, scontextp);
1370 	if (!typdatum || typdatum->attribute)
1371 		goto out;
1372 
1373 	ctx->type = typdatum->value;
1374 
1375 	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1376 	if (rc)
1377 		goto out;
1378 
1379 	rc = -EINVAL;
1380 	if ((p - scontext) < scontext_len)
1381 		goto out;
1382 
1383 	/* Check the validity of the new context. */
1384 	if (!policydb_context_isvalid(pol, ctx))
1385 		goto out;
1386 	rc = 0;
1387 out:
1388 	if (rc)
1389 		context_destroy(ctx);
1390 	return rc;
1391 }
1392 
1393 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1394 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1395 					int force)
1396 {
1397 	char *scontext2, *str = NULL;
1398 	struct context context;
1399 	int rc = 0;
1400 
1401 	/* An empty security context is never valid. */
1402 	if (!scontext_len)
1403 		return -EINVAL;
1404 
1405 	if (!ss_initialized) {
1406 		int i;
1407 
1408 		for (i = 1; i < SECINITSID_NUM; i++) {
1409 			if (!strcmp(initial_sid_to_string[i], scontext)) {
1410 				*sid = i;
1411 				return 0;
1412 			}
1413 		}
1414 		*sid = SECINITSID_KERNEL;
1415 		return 0;
1416 	}
1417 	*sid = SECSID_NULL;
1418 
1419 	/* Copy the string so that we can modify the copy as we parse it. */
1420 	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1421 	if (!scontext2)
1422 		return -ENOMEM;
1423 	memcpy(scontext2, scontext, scontext_len);
1424 	scontext2[scontext_len] = 0;
1425 
1426 	if (force) {
1427 		/* Save another copy for storing in uninterpreted form */
1428 		rc = -ENOMEM;
1429 		str = kstrdup(scontext2, gfp_flags);
1430 		if (!str)
1431 			goto out;
1432 	}
1433 
1434 	read_lock(&policy_rwlock);
1435 	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1436 				      scontext_len, &context, def_sid);
1437 	if (rc == -EINVAL && force) {
1438 		context.str = str;
1439 		context.len = scontext_len;
1440 		str = NULL;
1441 	} else if (rc)
1442 		goto out_unlock;
1443 	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1444 	context_destroy(&context);
1445 out_unlock:
1446 	read_unlock(&policy_rwlock);
1447 out:
1448 	kfree(scontext2);
1449 	kfree(str);
1450 	return rc;
1451 }
1452 
1453 /**
1454  * security_context_to_sid - Obtain a SID for a given security context.
1455  * @scontext: security context
1456  * @scontext_len: length in bytes
1457  * @sid: security identifier, SID
1458  * @gfp: context for the allocation
1459  *
1460  * Obtains a SID associated with the security context that
1461  * has the string representation specified by @scontext.
1462  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1463  * memory is available, or 0 on success.
1464  */
1465 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1466 			    gfp_t gfp)
1467 {
1468 	return security_context_to_sid_core(scontext, scontext_len,
1469 					    sid, SECSID_NULL, gfp, 0);
1470 }
1471 
1472 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1473 {
1474 	return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1475 }
1476 
1477 /**
1478  * security_context_to_sid_default - Obtain a SID for a given security context,
1479  * falling back to specified default if needed.
1480  *
1481  * @scontext: security context
1482  * @scontext_len: length in bytes
1483  * @sid: security identifier, SID
1484  * @def_sid: default SID to assign on error
1485  *
1486  * Obtains a SID associated with the security context that
1487  * has the string representation specified by @scontext.
1488  * The default SID is passed to the MLS layer to be used to allow
1489  * kernel labeling of the MLS field if the MLS field is not present
1490  * (for upgrading to MLS without full relabel).
1491  * Implicitly forces adding of the context even if it cannot be mapped yet.
1492  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1493  * memory is available, or 0 on success.
1494  */
1495 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1496 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1497 {
1498 	return security_context_to_sid_core(scontext, scontext_len,
1499 					    sid, def_sid, gfp_flags, 1);
1500 }
1501 
1502 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1503 				  u32 *sid)
1504 {
1505 	return security_context_to_sid_core(scontext, scontext_len,
1506 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1507 }
1508 
1509 static int compute_sid_handle_invalid_context(
1510 	struct context *scontext,
1511 	struct context *tcontext,
1512 	u16 tclass,
1513 	struct context *newcontext)
1514 {
1515 	char *s = NULL, *t = NULL, *n = NULL;
1516 	u32 slen, tlen, nlen;
1517 
1518 	if (context_struct_to_string(scontext, &s, &slen))
1519 		goto out;
1520 	if (context_struct_to_string(tcontext, &t, &tlen))
1521 		goto out;
1522 	if (context_struct_to_string(newcontext, &n, &nlen))
1523 		goto out;
1524 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1525 		  "op=security_compute_sid invalid_context=%s"
1526 		  " scontext=%s"
1527 		  " tcontext=%s"
1528 		  " tclass=%s",
1529 		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1530 out:
1531 	kfree(s);
1532 	kfree(t);
1533 	kfree(n);
1534 	if (!selinux_enforcing)
1535 		return 0;
1536 	return -EACCES;
1537 }
1538 
1539 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1540 				  u32 stype, u32 ttype, u16 tclass,
1541 				  const char *objname)
1542 {
1543 	struct filename_trans ft;
1544 	struct filename_trans_datum *otype;
1545 
1546 	/*
1547 	 * Most filename trans rules are going to live in specific directories
1548 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1549 	 * if the ttype does not contain any rules.
1550 	 */
1551 	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1552 		return;
1553 
1554 	ft.stype = stype;
1555 	ft.ttype = ttype;
1556 	ft.tclass = tclass;
1557 	ft.name = objname;
1558 
1559 	otype = hashtab_search(p->filename_trans, &ft);
1560 	if (otype)
1561 		newcontext->type = otype->otype;
1562 }
1563 
1564 static int security_compute_sid(u32 ssid,
1565 				u32 tsid,
1566 				u16 orig_tclass,
1567 				u32 specified,
1568 				const char *objname,
1569 				u32 *out_sid,
1570 				bool kern)
1571 {
1572 	struct class_datum *cladatum = NULL;
1573 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1574 	struct role_trans *roletr = NULL;
1575 	struct avtab_key avkey;
1576 	struct avtab_datum *avdatum;
1577 	struct avtab_node *node;
1578 	u16 tclass;
1579 	int rc = 0;
1580 	bool sock;
1581 
1582 	if (!ss_initialized) {
1583 		switch (orig_tclass) {
1584 		case SECCLASS_PROCESS: /* kernel value */
1585 			*out_sid = ssid;
1586 			break;
1587 		default:
1588 			*out_sid = tsid;
1589 			break;
1590 		}
1591 		goto out;
1592 	}
1593 
1594 	context_init(&newcontext);
1595 
1596 	read_lock(&policy_rwlock);
1597 
1598 	if (kern) {
1599 		tclass = unmap_class(orig_tclass);
1600 		sock = security_is_socket_class(orig_tclass);
1601 	} else {
1602 		tclass = orig_tclass;
1603 		sock = security_is_socket_class(map_class(tclass));
1604 	}
1605 
1606 	scontext = sidtab_search(&sidtab, ssid);
1607 	if (!scontext) {
1608 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1609 		       __func__, ssid);
1610 		rc = -EINVAL;
1611 		goto out_unlock;
1612 	}
1613 	tcontext = sidtab_search(&sidtab, tsid);
1614 	if (!tcontext) {
1615 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1616 		       __func__, tsid);
1617 		rc = -EINVAL;
1618 		goto out_unlock;
1619 	}
1620 
1621 	if (tclass && tclass <= policydb.p_classes.nprim)
1622 		cladatum = policydb.class_val_to_struct[tclass - 1];
1623 
1624 	/* Set the user identity. */
1625 	switch (specified) {
1626 	case AVTAB_TRANSITION:
1627 	case AVTAB_CHANGE:
1628 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1629 			newcontext.user = tcontext->user;
1630 		} else {
1631 			/* notice this gets both DEFAULT_SOURCE and unset */
1632 			/* Use the process user identity. */
1633 			newcontext.user = scontext->user;
1634 		}
1635 		break;
1636 	case AVTAB_MEMBER:
1637 		/* Use the related object owner. */
1638 		newcontext.user = tcontext->user;
1639 		break;
1640 	}
1641 
1642 	/* Set the role to default values. */
1643 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1644 		newcontext.role = scontext->role;
1645 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1646 		newcontext.role = tcontext->role;
1647 	} else {
1648 		if ((tclass == policydb.process_class) || (sock == true))
1649 			newcontext.role = scontext->role;
1650 		else
1651 			newcontext.role = OBJECT_R_VAL;
1652 	}
1653 
1654 	/* Set the type to default values. */
1655 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1656 		newcontext.type = scontext->type;
1657 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1658 		newcontext.type = tcontext->type;
1659 	} else {
1660 		if ((tclass == policydb.process_class) || (sock == true)) {
1661 			/* Use the type of process. */
1662 			newcontext.type = scontext->type;
1663 		} else {
1664 			/* Use the type of the related object. */
1665 			newcontext.type = tcontext->type;
1666 		}
1667 	}
1668 
1669 	/* Look for a type transition/member/change rule. */
1670 	avkey.source_type = scontext->type;
1671 	avkey.target_type = tcontext->type;
1672 	avkey.target_class = tclass;
1673 	avkey.specified = specified;
1674 	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1675 
1676 	/* If no permanent rule, also check for enabled conditional rules */
1677 	if (!avdatum) {
1678 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1679 		for (; node; node = avtab_search_node_next(node, specified)) {
1680 			if (node->key.specified & AVTAB_ENABLED) {
1681 				avdatum = &node->datum;
1682 				break;
1683 			}
1684 		}
1685 	}
1686 
1687 	if (avdatum) {
1688 		/* Use the type from the type transition/member/change rule. */
1689 		newcontext.type = avdatum->u.data;
1690 	}
1691 
1692 	/* if we have a objname this is a file trans check so check those rules */
1693 	if (objname)
1694 		filename_compute_type(&policydb, &newcontext, scontext->type,
1695 				      tcontext->type, tclass, objname);
1696 
1697 	/* Check for class-specific changes. */
1698 	if (specified & AVTAB_TRANSITION) {
1699 		/* Look for a role transition rule. */
1700 		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1701 			if ((roletr->role == scontext->role) &&
1702 			    (roletr->type == tcontext->type) &&
1703 			    (roletr->tclass == tclass)) {
1704 				/* Use the role transition rule. */
1705 				newcontext.role = roletr->new_role;
1706 				break;
1707 			}
1708 		}
1709 	}
1710 
1711 	/* Set the MLS attributes.
1712 	   This is done last because it may allocate memory. */
1713 	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1714 			     &newcontext, sock);
1715 	if (rc)
1716 		goto out_unlock;
1717 
1718 	/* Check the validity of the context. */
1719 	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1720 		rc = compute_sid_handle_invalid_context(scontext,
1721 							tcontext,
1722 							tclass,
1723 							&newcontext);
1724 		if (rc)
1725 			goto out_unlock;
1726 	}
1727 	/* Obtain the sid for the context. */
1728 	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1729 out_unlock:
1730 	read_unlock(&policy_rwlock);
1731 	context_destroy(&newcontext);
1732 out:
1733 	return rc;
1734 }
1735 
1736 /**
1737  * security_transition_sid - Compute the SID for a new subject/object.
1738  * @ssid: source security identifier
1739  * @tsid: target security identifier
1740  * @tclass: target security class
1741  * @out_sid: security identifier for new subject/object
1742  *
1743  * Compute a SID to use for labeling a new subject or object in the
1744  * class @tclass based on a SID pair (@ssid, @tsid).
1745  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1746  * if insufficient memory is available, or %0 if the new SID was
1747  * computed successfully.
1748  */
1749 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1750 			    const struct qstr *qstr, u32 *out_sid)
1751 {
1752 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1753 				    qstr ? qstr->name : NULL, out_sid, true);
1754 }
1755 
1756 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1757 				 const char *objname, u32 *out_sid)
1758 {
1759 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1760 				    objname, out_sid, false);
1761 }
1762 
1763 /**
1764  * security_member_sid - Compute the SID for member selection.
1765  * @ssid: source security identifier
1766  * @tsid: target security identifier
1767  * @tclass: target security class
1768  * @out_sid: security identifier for selected member
1769  *
1770  * Compute a SID to use when selecting a member of a polyinstantiated
1771  * object of class @tclass based on a SID pair (@ssid, @tsid).
1772  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1773  * if insufficient memory is available, or %0 if the SID was
1774  * computed successfully.
1775  */
1776 int security_member_sid(u32 ssid,
1777 			u32 tsid,
1778 			u16 tclass,
1779 			u32 *out_sid)
1780 {
1781 	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1782 				    out_sid, false);
1783 }
1784 
1785 /**
1786  * security_change_sid - Compute the SID for object relabeling.
1787  * @ssid: source security identifier
1788  * @tsid: target security identifier
1789  * @tclass: target security class
1790  * @out_sid: security identifier for selected member
1791  *
1792  * Compute a SID to use for relabeling an object of class @tclass
1793  * based on a SID pair (@ssid, @tsid).
1794  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1795  * if insufficient memory is available, or %0 if the SID was
1796  * computed successfully.
1797  */
1798 int security_change_sid(u32 ssid,
1799 			u32 tsid,
1800 			u16 tclass,
1801 			u32 *out_sid)
1802 {
1803 	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1804 				    out_sid, false);
1805 }
1806 
1807 /* Clone the SID into the new SID table. */
1808 static int clone_sid(u32 sid,
1809 		     struct context *context,
1810 		     void *arg)
1811 {
1812 	struct sidtab *s = arg;
1813 
1814 	if (sid > SECINITSID_NUM)
1815 		return sidtab_insert(s, sid, context);
1816 	else
1817 		return 0;
1818 }
1819 
1820 static inline int convert_context_handle_invalid_context(struct context *context)
1821 {
1822 	char *s;
1823 	u32 len;
1824 
1825 	if (selinux_enforcing)
1826 		return -EINVAL;
1827 
1828 	if (!context_struct_to_string(context, &s, &len)) {
1829 		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1830 		kfree(s);
1831 	}
1832 	return 0;
1833 }
1834 
1835 struct convert_context_args {
1836 	struct policydb *oldp;
1837 	struct policydb *newp;
1838 };
1839 
1840 /*
1841  * Convert the values in the security context
1842  * structure `c' from the values specified
1843  * in the policy `p->oldp' to the values specified
1844  * in the policy `p->newp'.  Verify that the
1845  * context is valid under the new policy.
1846  */
1847 static int convert_context(u32 key,
1848 			   struct context *c,
1849 			   void *p)
1850 {
1851 	struct convert_context_args *args;
1852 	struct context oldc;
1853 	struct ocontext *oc;
1854 	struct mls_range *range;
1855 	struct role_datum *role;
1856 	struct type_datum *typdatum;
1857 	struct user_datum *usrdatum;
1858 	char *s;
1859 	u32 len;
1860 	int rc = 0;
1861 
1862 	if (key <= SECINITSID_NUM)
1863 		goto out;
1864 
1865 	args = p;
1866 
1867 	if (c->str) {
1868 		struct context ctx;
1869 
1870 		rc = -ENOMEM;
1871 		s = kstrdup(c->str, GFP_KERNEL);
1872 		if (!s)
1873 			goto out;
1874 
1875 		rc = string_to_context_struct(args->newp, NULL, s,
1876 					      c->len, &ctx, SECSID_NULL);
1877 		kfree(s);
1878 		if (!rc) {
1879 			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1880 			       c->str);
1881 			/* Replace string with mapped representation. */
1882 			kfree(c->str);
1883 			memcpy(c, &ctx, sizeof(*c));
1884 			goto out;
1885 		} else if (rc == -EINVAL) {
1886 			/* Retain string representation for later mapping. */
1887 			rc = 0;
1888 			goto out;
1889 		} else {
1890 			/* Other error condition, e.g. ENOMEM. */
1891 			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1892 			       c->str, -rc);
1893 			goto out;
1894 		}
1895 	}
1896 
1897 	rc = context_cpy(&oldc, c);
1898 	if (rc)
1899 		goto out;
1900 
1901 	/* Convert the user. */
1902 	rc = -EINVAL;
1903 	usrdatum = hashtab_search(args->newp->p_users.table,
1904 				  sym_name(args->oldp, SYM_USERS, c->user - 1));
1905 	if (!usrdatum)
1906 		goto bad;
1907 	c->user = usrdatum->value;
1908 
1909 	/* Convert the role. */
1910 	rc = -EINVAL;
1911 	role = hashtab_search(args->newp->p_roles.table,
1912 			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
1913 	if (!role)
1914 		goto bad;
1915 	c->role = role->value;
1916 
1917 	/* Convert the type. */
1918 	rc = -EINVAL;
1919 	typdatum = hashtab_search(args->newp->p_types.table,
1920 				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
1921 	if (!typdatum)
1922 		goto bad;
1923 	c->type = typdatum->value;
1924 
1925 	/* Convert the MLS fields if dealing with MLS policies */
1926 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1927 		rc = mls_convert_context(args->oldp, args->newp, c);
1928 		if (rc)
1929 			goto bad;
1930 	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1931 		/*
1932 		 * Switching between MLS and non-MLS policy:
1933 		 * free any storage used by the MLS fields in the
1934 		 * context for all existing entries in the sidtab.
1935 		 */
1936 		mls_context_destroy(c);
1937 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1938 		/*
1939 		 * Switching between non-MLS and MLS policy:
1940 		 * ensure that the MLS fields of the context for all
1941 		 * existing entries in the sidtab are filled in with a
1942 		 * suitable default value, likely taken from one of the
1943 		 * initial SIDs.
1944 		 */
1945 		oc = args->newp->ocontexts[OCON_ISID];
1946 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1947 			oc = oc->next;
1948 		rc = -EINVAL;
1949 		if (!oc) {
1950 			printk(KERN_ERR "SELinux:  unable to look up"
1951 				" the initial SIDs list\n");
1952 			goto bad;
1953 		}
1954 		range = &oc->context[0].range;
1955 		rc = mls_range_set(c, range);
1956 		if (rc)
1957 			goto bad;
1958 	}
1959 
1960 	/* Check the validity of the new context. */
1961 	if (!policydb_context_isvalid(args->newp, c)) {
1962 		rc = convert_context_handle_invalid_context(&oldc);
1963 		if (rc)
1964 			goto bad;
1965 	}
1966 
1967 	context_destroy(&oldc);
1968 
1969 	rc = 0;
1970 out:
1971 	return rc;
1972 bad:
1973 	/* Map old representation to string and save it. */
1974 	rc = context_struct_to_string(&oldc, &s, &len);
1975 	if (rc)
1976 		return rc;
1977 	context_destroy(&oldc);
1978 	context_destroy(c);
1979 	c->str = s;
1980 	c->len = len;
1981 	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1982 	       c->str);
1983 	rc = 0;
1984 	goto out;
1985 }
1986 
1987 static void security_load_policycaps(void)
1988 {
1989 	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1990 						  POLICYDB_CAPABILITY_NETPEER);
1991 	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1992 						  POLICYDB_CAPABILITY_OPENPERM);
1993 	selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
1994 					  POLICYDB_CAPABILITY_EXTSOCKCLASS);
1995 	selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1996 						  POLICYDB_CAPABILITY_ALWAYSNETWORK);
1997 	selinux_policycap_cgroupseclabel =
1998 		ebitmap_get_bit(&policydb.policycaps,
1999 				POLICYDB_CAPABILITY_CGROUPSECLABEL);
2000 }
2001 
2002 static int security_preserve_bools(struct policydb *p);
2003 
2004 /**
2005  * security_load_policy - Load a security policy configuration.
2006  * @data: binary policy data
2007  * @len: length of data in bytes
2008  *
2009  * Load a new set of security policy configuration data,
2010  * validate it and convert the SID table as necessary.
2011  * This function will flush the access vector cache after
2012  * loading the new policy.
2013  */
2014 int security_load_policy(void *data, size_t len)
2015 {
2016 	struct policydb *oldpolicydb, *newpolicydb;
2017 	struct sidtab oldsidtab, newsidtab;
2018 	struct selinux_mapping *oldmap, *map = NULL;
2019 	struct convert_context_args args;
2020 	u32 seqno;
2021 	u16 map_size;
2022 	int rc = 0;
2023 	struct policy_file file = { data, len }, *fp = &file;
2024 
2025 	oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2026 	if (!oldpolicydb) {
2027 		rc = -ENOMEM;
2028 		goto out;
2029 	}
2030 	newpolicydb = oldpolicydb + 1;
2031 
2032 	if (!ss_initialized) {
2033 		avtab_cache_init();
2034 		rc = policydb_read(&policydb, fp);
2035 		if (rc) {
2036 			avtab_cache_destroy();
2037 			goto out;
2038 		}
2039 
2040 		policydb.len = len;
2041 		rc = selinux_set_mapping(&policydb, secclass_map,
2042 					 &current_mapping,
2043 					 &current_mapping_size);
2044 		if (rc) {
2045 			policydb_destroy(&policydb);
2046 			avtab_cache_destroy();
2047 			goto out;
2048 		}
2049 
2050 		rc = policydb_load_isids(&policydb, &sidtab);
2051 		if (rc) {
2052 			policydb_destroy(&policydb);
2053 			avtab_cache_destroy();
2054 			goto out;
2055 		}
2056 
2057 		security_load_policycaps();
2058 		ss_initialized = 1;
2059 		seqno = ++latest_granting;
2060 		selinux_complete_init();
2061 		avc_ss_reset(seqno);
2062 		selnl_notify_policyload(seqno);
2063 		selinux_status_update_policyload(seqno);
2064 		selinux_netlbl_cache_invalidate();
2065 		selinux_xfrm_notify_policyload();
2066 		goto out;
2067 	}
2068 
2069 #if 0
2070 	sidtab_hash_eval(&sidtab, "sids");
2071 #endif
2072 
2073 	rc = policydb_read(newpolicydb, fp);
2074 	if (rc)
2075 		goto out;
2076 
2077 	newpolicydb->len = len;
2078 	/* If switching between different policy types, log MLS status */
2079 	if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2080 		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2081 	else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2082 		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2083 
2084 	rc = policydb_load_isids(newpolicydb, &newsidtab);
2085 	if (rc) {
2086 		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2087 		policydb_destroy(newpolicydb);
2088 		goto out;
2089 	}
2090 
2091 	rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2092 	if (rc)
2093 		goto err;
2094 
2095 	rc = security_preserve_bools(newpolicydb);
2096 	if (rc) {
2097 		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2098 		goto err;
2099 	}
2100 
2101 	/* Clone the SID table. */
2102 	sidtab_shutdown(&sidtab);
2103 
2104 	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2105 	if (rc)
2106 		goto err;
2107 
2108 	/*
2109 	 * Convert the internal representations of contexts
2110 	 * in the new SID table.
2111 	 */
2112 	args.oldp = &policydb;
2113 	args.newp = newpolicydb;
2114 	rc = sidtab_map(&newsidtab, convert_context, &args);
2115 	if (rc) {
2116 		printk(KERN_ERR "SELinux:  unable to convert the internal"
2117 			" representation of contexts in the new SID"
2118 			" table\n");
2119 		goto err;
2120 	}
2121 
2122 	/* Save the old policydb and SID table to free later. */
2123 	memcpy(oldpolicydb, &policydb, sizeof(policydb));
2124 	sidtab_set(&oldsidtab, &sidtab);
2125 
2126 	/* Install the new policydb and SID table. */
2127 	write_lock_irq(&policy_rwlock);
2128 	memcpy(&policydb, newpolicydb, sizeof(policydb));
2129 	sidtab_set(&sidtab, &newsidtab);
2130 	security_load_policycaps();
2131 	oldmap = current_mapping;
2132 	current_mapping = map;
2133 	current_mapping_size = map_size;
2134 	seqno = ++latest_granting;
2135 	write_unlock_irq(&policy_rwlock);
2136 
2137 	/* Free the old policydb and SID table. */
2138 	policydb_destroy(oldpolicydb);
2139 	sidtab_destroy(&oldsidtab);
2140 	kfree(oldmap);
2141 
2142 	avc_ss_reset(seqno);
2143 	selnl_notify_policyload(seqno);
2144 	selinux_status_update_policyload(seqno);
2145 	selinux_netlbl_cache_invalidate();
2146 	selinux_xfrm_notify_policyload();
2147 
2148 	rc = 0;
2149 	goto out;
2150 
2151 err:
2152 	kfree(map);
2153 	sidtab_destroy(&newsidtab);
2154 	policydb_destroy(newpolicydb);
2155 
2156 out:
2157 	kfree(oldpolicydb);
2158 	return rc;
2159 }
2160 
2161 size_t security_policydb_len(void)
2162 {
2163 	size_t len;
2164 
2165 	read_lock(&policy_rwlock);
2166 	len = policydb.len;
2167 	read_unlock(&policy_rwlock);
2168 
2169 	return len;
2170 }
2171 
2172 /**
2173  * security_port_sid - Obtain the SID for a port.
2174  * @protocol: protocol number
2175  * @port: port number
2176  * @out_sid: security identifier
2177  */
2178 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2179 {
2180 	struct ocontext *c;
2181 	int rc = 0;
2182 
2183 	read_lock(&policy_rwlock);
2184 
2185 	c = policydb.ocontexts[OCON_PORT];
2186 	while (c) {
2187 		if (c->u.port.protocol == protocol &&
2188 		    c->u.port.low_port <= port &&
2189 		    c->u.port.high_port >= port)
2190 			break;
2191 		c = c->next;
2192 	}
2193 
2194 	if (c) {
2195 		if (!c->sid[0]) {
2196 			rc = sidtab_context_to_sid(&sidtab,
2197 						   &c->context[0],
2198 						   &c->sid[0]);
2199 			if (rc)
2200 				goto out;
2201 		}
2202 		*out_sid = c->sid[0];
2203 	} else {
2204 		*out_sid = SECINITSID_PORT;
2205 	}
2206 
2207 out:
2208 	read_unlock(&policy_rwlock);
2209 	return rc;
2210 }
2211 
2212 /**
2213  * security_netif_sid - Obtain the SID for a network interface.
2214  * @name: interface name
2215  * @if_sid: interface SID
2216  */
2217 int security_netif_sid(char *name, u32 *if_sid)
2218 {
2219 	int rc = 0;
2220 	struct ocontext *c;
2221 
2222 	read_lock(&policy_rwlock);
2223 
2224 	c = policydb.ocontexts[OCON_NETIF];
2225 	while (c) {
2226 		if (strcmp(name, c->u.name) == 0)
2227 			break;
2228 		c = c->next;
2229 	}
2230 
2231 	if (c) {
2232 		if (!c->sid[0] || !c->sid[1]) {
2233 			rc = sidtab_context_to_sid(&sidtab,
2234 						  &c->context[0],
2235 						  &c->sid[0]);
2236 			if (rc)
2237 				goto out;
2238 			rc = sidtab_context_to_sid(&sidtab,
2239 						   &c->context[1],
2240 						   &c->sid[1]);
2241 			if (rc)
2242 				goto out;
2243 		}
2244 		*if_sid = c->sid[0];
2245 	} else
2246 		*if_sid = SECINITSID_NETIF;
2247 
2248 out:
2249 	read_unlock(&policy_rwlock);
2250 	return rc;
2251 }
2252 
2253 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2254 {
2255 	int i, fail = 0;
2256 
2257 	for (i = 0; i < 4; i++)
2258 		if (addr[i] != (input[i] & mask[i])) {
2259 			fail = 1;
2260 			break;
2261 		}
2262 
2263 	return !fail;
2264 }
2265 
2266 /**
2267  * security_node_sid - Obtain the SID for a node (host).
2268  * @domain: communication domain aka address family
2269  * @addrp: address
2270  * @addrlen: address length in bytes
2271  * @out_sid: security identifier
2272  */
2273 int security_node_sid(u16 domain,
2274 		      void *addrp,
2275 		      u32 addrlen,
2276 		      u32 *out_sid)
2277 {
2278 	int rc;
2279 	struct ocontext *c;
2280 
2281 	read_lock(&policy_rwlock);
2282 
2283 	switch (domain) {
2284 	case AF_INET: {
2285 		u32 addr;
2286 
2287 		rc = -EINVAL;
2288 		if (addrlen != sizeof(u32))
2289 			goto out;
2290 
2291 		addr = *((u32 *)addrp);
2292 
2293 		c = policydb.ocontexts[OCON_NODE];
2294 		while (c) {
2295 			if (c->u.node.addr == (addr & c->u.node.mask))
2296 				break;
2297 			c = c->next;
2298 		}
2299 		break;
2300 	}
2301 
2302 	case AF_INET6:
2303 		rc = -EINVAL;
2304 		if (addrlen != sizeof(u64) * 2)
2305 			goto out;
2306 		c = policydb.ocontexts[OCON_NODE6];
2307 		while (c) {
2308 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2309 						c->u.node6.mask))
2310 				break;
2311 			c = c->next;
2312 		}
2313 		break;
2314 
2315 	default:
2316 		rc = 0;
2317 		*out_sid = SECINITSID_NODE;
2318 		goto out;
2319 	}
2320 
2321 	if (c) {
2322 		if (!c->sid[0]) {
2323 			rc = sidtab_context_to_sid(&sidtab,
2324 						   &c->context[0],
2325 						   &c->sid[0]);
2326 			if (rc)
2327 				goto out;
2328 		}
2329 		*out_sid = c->sid[0];
2330 	} else {
2331 		*out_sid = SECINITSID_NODE;
2332 	}
2333 
2334 	rc = 0;
2335 out:
2336 	read_unlock(&policy_rwlock);
2337 	return rc;
2338 }
2339 
2340 #define SIDS_NEL 25
2341 
2342 /**
2343  * security_get_user_sids - Obtain reachable SIDs for a user.
2344  * @fromsid: starting SID
2345  * @username: username
2346  * @sids: array of reachable SIDs for user
2347  * @nel: number of elements in @sids
2348  *
2349  * Generate the set of SIDs for legal security contexts
2350  * for a given user that can be reached by @fromsid.
2351  * Set *@sids to point to a dynamically allocated
2352  * array containing the set of SIDs.  Set *@nel to the
2353  * number of elements in the array.
2354  */
2355 
2356 int security_get_user_sids(u32 fromsid,
2357 			   char *username,
2358 			   u32 **sids,
2359 			   u32 *nel)
2360 {
2361 	struct context *fromcon, usercon;
2362 	u32 *mysids = NULL, *mysids2, sid;
2363 	u32 mynel = 0, maxnel = SIDS_NEL;
2364 	struct user_datum *user;
2365 	struct role_datum *role;
2366 	struct ebitmap_node *rnode, *tnode;
2367 	int rc = 0, i, j;
2368 
2369 	*sids = NULL;
2370 	*nel = 0;
2371 
2372 	if (!ss_initialized)
2373 		goto out;
2374 
2375 	read_lock(&policy_rwlock);
2376 
2377 	context_init(&usercon);
2378 
2379 	rc = -EINVAL;
2380 	fromcon = sidtab_search(&sidtab, fromsid);
2381 	if (!fromcon)
2382 		goto out_unlock;
2383 
2384 	rc = -EINVAL;
2385 	user = hashtab_search(policydb.p_users.table, username);
2386 	if (!user)
2387 		goto out_unlock;
2388 
2389 	usercon.user = user->value;
2390 
2391 	rc = -ENOMEM;
2392 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2393 	if (!mysids)
2394 		goto out_unlock;
2395 
2396 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2397 		role = policydb.role_val_to_struct[i];
2398 		usercon.role = i + 1;
2399 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2400 			usercon.type = j + 1;
2401 
2402 			if (mls_setup_user_range(fromcon, user, &usercon))
2403 				continue;
2404 
2405 			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2406 			if (rc)
2407 				goto out_unlock;
2408 			if (mynel < maxnel) {
2409 				mysids[mynel++] = sid;
2410 			} else {
2411 				rc = -ENOMEM;
2412 				maxnel += SIDS_NEL;
2413 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2414 				if (!mysids2)
2415 					goto out_unlock;
2416 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2417 				kfree(mysids);
2418 				mysids = mysids2;
2419 				mysids[mynel++] = sid;
2420 			}
2421 		}
2422 	}
2423 	rc = 0;
2424 out_unlock:
2425 	read_unlock(&policy_rwlock);
2426 	if (rc || !mynel) {
2427 		kfree(mysids);
2428 		goto out;
2429 	}
2430 
2431 	rc = -ENOMEM;
2432 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2433 	if (!mysids2) {
2434 		kfree(mysids);
2435 		goto out;
2436 	}
2437 	for (i = 0, j = 0; i < mynel; i++) {
2438 		struct av_decision dummy_avd;
2439 		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2440 					  SECCLASS_PROCESS, /* kernel value */
2441 					  PROCESS__TRANSITION, AVC_STRICT,
2442 					  &dummy_avd);
2443 		if (!rc)
2444 			mysids2[j++] = mysids[i];
2445 		cond_resched();
2446 	}
2447 	rc = 0;
2448 	kfree(mysids);
2449 	*sids = mysids2;
2450 	*nel = j;
2451 out:
2452 	return rc;
2453 }
2454 
2455 /**
2456  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2457  * @fstype: filesystem type
2458  * @path: path from root of mount
2459  * @sclass: file security class
2460  * @sid: SID for path
2461  *
2462  * Obtain a SID to use for a file in a filesystem that
2463  * cannot support xattr or use a fixed labeling behavior like
2464  * transition SIDs or task SIDs.
2465  *
2466  * The caller must acquire the policy_rwlock before calling this function.
2467  */
2468 static inline int __security_genfs_sid(const char *fstype,
2469 				       char *path,
2470 				       u16 orig_sclass,
2471 				       u32 *sid)
2472 {
2473 	int len;
2474 	u16 sclass;
2475 	struct genfs *genfs;
2476 	struct ocontext *c;
2477 	int rc, cmp = 0;
2478 
2479 	while (path[0] == '/' && path[1] == '/')
2480 		path++;
2481 
2482 	sclass = unmap_class(orig_sclass);
2483 	*sid = SECINITSID_UNLABELED;
2484 
2485 	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2486 		cmp = strcmp(fstype, genfs->fstype);
2487 		if (cmp <= 0)
2488 			break;
2489 	}
2490 
2491 	rc = -ENOENT;
2492 	if (!genfs || cmp)
2493 		goto out;
2494 
2495 	for (c = genfs->head; c; c = c->next) {
2496 		len = strlen(c->u.name);
2497 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2498 		    (strncmp(c->u.name, path, len) == 0))
2499 			break;
2500 	}
2501 
2502 	rc = -ENOENT;
2503 	if (!c)
2504 		goto out;
2505 
2506 	if (!c->sid[0]) {
2507 		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2508 		if (rc)
2509 			goto out;
2510 	}
2511 
2512 	*sid = c->sid[0];
2513 	rc = 0;
2514 out:
2515 	return rc;
2516 }
2517 
2518 /**
2519  * security_genfs_sid - Obtain a SID for a file in a filesystem
2520  * @fstype: filesystem type
2521  * @path: path from root of mount
2522  * @sclass: file security class
2523  * @sid: SID for path
2524  *
2525  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2526  * it afterward.
2527  */
2528 int security_genfs_sid(const char *fstype,
2529 		       char *path,
2530 		       u16 orig_sclass,
2531 		       u32 *sid)
2532 {
2533 	int retval;
2534 
2535 	read_lock(&policy_rwlock);
2536 	retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2537 	read_unlock(&policy_rwlock);
2538 	return retval;
2539 }
2540 
2541 /**
2542  * security_fs_use - Determine how to handle labeling for a filesystem.
2543  * @sb: superblock in question
2544  */
2545 int security_fs_use(struct super_block *sb)
2546 {
2547 	int rc = 0;
2548 	struct ocontext *c;
2549 	struct superblock_security_struct *sbsec = sb->s_security;
2550 	const char *fstype = sb->s_type->name;
2551 
2552 	read_lock(&policy_rwlock);
2553 
2554 	c = policydb.ocontexts[OCON_FSUSE];
2555 	while (c) {
2556 		if (strcmp(fstype, c->u.name) == 0)
2557 			break;
2558 		c = c->next;
2559 	}
2560 
2561 	if (c) {
2562 		sbsec->behavior = c->v.behavior;
2563 		if (!c->sid[0]) {
2564 			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2565 						   &c->sid[0]);
2566 			if (rc)
2567 				goto out;
2568 		}
2569 		sbsec->sid = c->sid[0];
2570 	} else {
2571 		rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2572 					  &sbsec->sid);
2573 		if (rc) {
2574 			sbsec->behavior = SECURITY_FS_USE_NONE;
2575 			rc = 0;
2576 		} else {
2577 			sbsec->behavior = SECURITY_FS_USE_GENFS;
2578 		}
2579 	}
2580 
2581 out:
2582 	read_unlock(&policy_rwlock);
2583 	return rc;
2584 }
2585 
2586 int security_get_bools(int *len, char ***names, int **values)
2587 {
2588 	int i, rc;
2589 
2590 	read_lock(&policy_rwlock);
2591 	*names = NULL;
2592 	*values = NULL;
2593 
2594 	rc = 0;
2595 	*len = policydb.p_bools.nprim;
2596 	if (!*len)
2597 		goto out;
2598 
2599 	rc = -ENOMEM;
2600 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2601 	if (!*names)
2602 		goto err;
2603 
2604 	rc = -ENOMEM;
2605 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2606 	if (!*values)
2607 		goto err;
2608 
2609 	for (i = 0; i < *len; i++) {
2610 		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2611 
2612 		rc = -ENOMEM;
2613 		(*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2614 		if (!(*names)[i])
2615 			goto err;
2616 	}
2617 	rc = 0;
2618 out:
2619 	read_unlock(&policy_rwlock);
2620 	return rc;
2621 err:
2622 	if (*names) {
2623 		for (i = 0; i < *len; i++)
2624 			kfree((*names)[i]);
2625 	}
2626 	kfree(*values);
2627 	goto out;
2628 }
2629 
2630 
2631 int security_set_bools(int len, int *values)
2632 {
2633 	int i, rc;
2634 	int lenp, seqno = 0;
2635 	struct cond_node *cur;
2636 
2637 	write_lock_irq(&policy_rwlock);
2638 
2639 	rc = -EFAULT;
2640 	lenp = policydb.p_bools.nprim;
2641 	if (len != lenp)
2642 		goto out;
2643 
2644 	for (i = 0; i < len; i++) {
2645 		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2646 			audit_log(current->audit_context, GFP_ATOMIC,
2647 				AUDIT_MAC_CONFIG_CHANGE,
2648 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2649 				sym_name(&policydb, SYM_BOOLS, i),
2650 				!!values[i],
2651 				policydb.bool_val_to_struct[i]->state,
2652 				from_kuid(&init_user_ns, audit_get_loginuid(current)),
2653 				audit_get_sessionid(current));
2654 		}
2655 		if (values[i])
2656 			policydb.bool_val_to_struct[i]->state = 1;
2657 		else
2658 			policydb.bool_val_to_struct[i]->state = 0;
2659 	}
2660 
2661 	for (cur = policydb.cond_list; cur; cur = cur->next) {
2662 		rc = evaluate_cond_node(&policydb, cur);
2663 		if (rc)
2664 			goto out;
2665 	}
2666 
2667 	seqno = ++latest_granting;
2668 	rc = 0;
2669 out:
2670 	write_unlock_irq(&policy_rwlock);
2671 	if (!rc) {
2672 		avc_ss_reset(seqno);
2673 		selnl_notify_policyload(seqno);
2674 		selinux_status_update_policyload(seqno);
2675 		selinux_xfrm_notify_policyload();
2676 	}
2677 	return rc;
2678 }
2679 
2680 int security_get_bool_value(int index)
2681 {
2682 	int rc;
2683 	int len;
2684 
2685 	read_lock(&policy_rwlock);
2686 
2687 	rc = -EFAULT;
2688 	len = policydb.p_bools.nprim;
2689 	if (index >= len)
2690 		goto out;
2691 
2692 	rc = policydb.bool_val_to_struct[index]->state;
2693 out:
2694 	read_unlock(&policy_rwlock);
2695 	return rc;
2696 }
2697 
2698 static int security_preserve_bools(struct policydb *p)
2699 {
2700 	int rc, nbools = 0, *bvalues = NULL, i;
2701 	char **bnames = NULL;
2702 	struct cond_bool_datum *booldatum;
2703 	struct cond_node *cur;
2704 
2705 	rc = security_get_bools(&nbools, &bnames, &bvalues);
2706 	if (rc)
2707 		goto out;
2708 	for (i = 0; i < nbools; i++) {
2709 		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2710 		if (booldatum)
2711 			booldatum->state = bvalues[i];
2712 	}
2713 	for (cur = p->cond_list; cur; cur = cur->next) {
2714 		rc = evaluate_cond_node(p, cur);
2715 		if (rc)
2716 			goto out;
2717 	}
2718 
2719 out:
2720 	if (bnames) {
2721 		for (i = 0; i < nbools; i++)
2722 			kfree(bnames[i]);
2723 	}
2724 	kfree(bnames);
2725 	kfree(bvalues);
2726 	return rc;
2727 }
2728 
2729 /*
2730  * security_sid_mls_copy() - computes a new sid based on the given
2731  * sid and the mls portion of mls_sid.
2732  */
2733 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2734 {
2735 	struct context *context1;
2736 	struct context *context2;
2737 	struct context newcon;
2738 	char *s;
2739 	u32 len;
2740 	int rc;
2741 
2742 	rc = 0;
2743 	if (!ss_initialized || !policydb.mls_enabled) {
2744 		*new_sid = sid;
2745 		goto out;
2746 	}
2747 
2748 	context_init(&newcon);
2749 
2750 	read_lock(&policy_rwlock);
2751 
2752 	rc = -EINVAL;
2753 	context1 = sidtab_search(&sidtab, sid);
2754 	if (!context1) {
2755 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2756 			__func__, sid);
2757 		goto out_unlock;
2758 	}
2759 
2760 	rc = -EINVAL;
2761 	context2 = sidtab_search(&sidtab, mls_sid);
2762 	if (!context2) {
2763 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2764 			__func__, mls_sid);
2765 		goto out_unlock;
2766 	}
2767 
2768 	newcon.user = context1->user;
2769 	newcon.role = context1->role;
2770 	newcon.type = context1->type;
2771 	rc = mls_context_cpy(&newcon, context2);
2772 	if (rc)
2773 		goto out_unlock;
2774 
2775 	/* Check the validity of the new context. */
2776 	if (!policydb_context_isvalid(&policydb, &newcon)) {
2777 		rc = convert_context_handle_invalid_context(&newcon);
2778 		if (rc) {
2779 			if (!context_struct_to_string(&newcon, &s, &len)) {
2780 				audit_log(current->audit_context,
2781 					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
2782 					  "op=security_sid_mls_copy "
2783 					  "invalid_context=%s", s);
2784 				kfree(s);
2785 			}
2786 			goto out_unlock;
2787 		}
2788 	}
2789 
2790 	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2791 out_unlock:
2792 	read_unlock(&policy_rwlock);
2793 	context_destroy(&newcon);
2794 out:
2795 	return rc;
2796 }
2797 
2798 /**
2799  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2800  * @nlbl_sid: NetLabel SID
2801  * @nlbl_type: NetLabel labeling protocol type
2802  * @xfrm_sid: XFRM SID
2803  *
2804  * Description:
2805  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2806  * resolved into a single SID it is returned via @peer_sid and the function
2807  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2808  * returns a negative value.  A table summarizing the behavior is below:
2809  *
2810  *                                 | function return |      @sid
2811  *   ------------------------------+-----------------+-----------------
2812  *   no peer labels                |        0        |    SECSID_NULL
2813  *   single peer label             |        0        |    <peer_label>
2814  *   multiple, consistent labels   |        0        |    <peer_label>
2815  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2816  *
2817  */
2818 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2819 				 u32 xfrm_sid,
2820 				 u32 *peer_sid)
2821 {
2822 	int rc;
2823 	struct context *nlbl_ctx;
2824 	struct context *xfrm_ctx;
2825 
2826 	*peer_sid = SECSID_NULL;
2827 
2828 	/* handle the common (which also happens to be the set of easy) cases
2829 	 * right away, these two if statements catch everything involving a
2830 	 * single or absent peer SID/label */
2831 	if (xfrm_sid == SECSID_NULL) {
2832 		*peer_sid = nlbl_sid;
2833 		return 0;
2834 	}
2835 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2836 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2837 	 * is present */
2838 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2839 		*peer_sid = xfrm_sid;
2840 		return 0;
2841 	}
2842 
2843 	/* we don't need to check ss_initialized here since the only way both
2844 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2845 	 * security server was initialized and ss_initialized was true */
2846 	if (!policydb.mls_enabled)
2847 		return 0;
2848 
2849 	read_lock(&policy_rwlock);
2850 
2851 	rc = -EINVAL;
2852 	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2853 	if (!nlbl_ctx) {
2854 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2855 		       __func__, nlbl_sid);
2856 		goto out;
2857 	}
2858 	rc = -EINVAL;
2859 	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2860 	if (!xfrm_ctx) {
2861 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2862 		       __func__, xfrm_sid);
2863 		goto out;
2864 	}
2865 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2866 	if (rc)
2867 		goto out;
2868 
2869 	/* at present NetLabel SIDs/labels really only carry MLS
2870 	 * information so if the MLS portion of the NetLabel SID
2871 	 * matches the MLS portion of the labeled XFRM SID/label
2872 	 * then pass along the XFRM SID as it is the most
2873 	 * expressive */
2874 	*peer_sid = xfrm_sid;
2875 out:
2876 	read_unlock(&policy_rwlock);
2877 	return rc;
2878 }
2879 
2880 static int get_classes_callback(void *k, void *d, void *args)
2881 {
2882 	struct class_datum *datum = d;
2883 	char *name = k, **classes = args;
2884 	int value = datum->value - 1;
2885 
2886 	classes[value] = kstrdup(name, GFP_ATOMIC);
2887 	if (!classes[value])
2888 		return -ENOMEM;
2889 
2890 	return 0;
2891 }
2892 
2893 int security_get_classes(char ***classes, int *nclasses)
2894 {
2895 	int rc;
2896 
2897 	read_lock(&policy_rwlock);
2898 
2899 	rc = -ENOMEM;
2900 	*nclasses = policydb.p_classes.nprim;
2901 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2902 	if (!*classes)
2903 		goto out;
2904 
2905 	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2906 			*classes);
2907 	if (rc) {
2908 		int i;
2909 		for (i = 0; i < *nclasses; i++)
2910 			kfree((*classes)[i]);
2911 		kfree(*classes);
2912 	}
2913 
2914 out:
2915 	read_unlock(&policy_rwlock);
2916 	return rc;
2917 }
2918 
2919 static int get_permissions_callback(void *k, void *d, void *args)
2920 {
2921 	struct perm_datum *datum = d;
2922 	char *name = k, **perms = args;
2923 	int value = datum->value - 1;
2924 
2925 	perms[value] = kstrdup(name, GFP_ATOMIC);
2926 	if (!perms[value])
2927 		return -ENOMEM;
2928 
2929 	return 0;
2930 }
2931 
2932 int security_get_permissions(char *class, char ***perms, int *nperms)
2933 {
2934 	int rc, i;
2935 	struct class_datum *match;
2936 
2937 	read_lock(&policy_rwlock);
2938 
2939 	rc = -EINVAL;
2940 	match = hashtab_search(policydb.p_classes.table, class);
2941 	if (!match) {
2942 		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2943 			__func__, class);
2944 		goto out;
2945 	}
2946 
2947 	rc = -ENOMEM;
2948 	*nperms = match->permissions.nprim;
2949 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2950 	if (!*perms)
2951 		goto out;
2952 
2953 	if (match->comdatum) {
2954 		rc = hashtab_map(match->comdatum->permissions.table,
2955 				get_permissions_callback, *perms);
2956 		if (rc)
2957 			goto err;
2958 	}
2959 
2960 	rc = hashtab_map(match->permissions.table, get_permissions_callback,
2961 			*perms);
2962 	if (rc)
2963 		goto err;
2964 
2965 out:
2966 	read_unlock(&policy_rwlock);
2967 	return rc;
2968 
2969 err:
2970 	read_unlock(&policy_rwlock);
2971 	for (i = 0; i < *nperms; i++)
2972 		kfree((*perms)[i]);
2973 	kfree(*perms);
2974 	return rc;
2975 }
2976 
2977 int security_get_reject_unknown(void)
2978 {
2979 	return policydb.reject_unknown;
2980 }
2981 
2982 int security_get_allow_unknown(void)
2983 {
2984 	return policydb.allow_unknown;
2985 }
2986 
2987 /**
2988  * security_policycap_supported - Check for a specific policy capability
2989  * @req_cap: capability
2990  *
2991  * Description:
2992  * This function queries the currently loaded policy to see if it supports the
2993  * capability specified by @req_cap.  Returns true (1) if the capability is
2994  * supported, false (0) if it isn't supported.
2995  *
2996  */
2997 int security_policycap_supported(unsigned int req_cap)
2998 {
2999 	int rc;
3000 
3001 	read_lock(&policy_rwlock);
3002 	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3003 	read_unlock(&policy_rwlock);
3004 
3005 	return rc;
3006 }
3007 
3008 struct selinux_audit_rule {
3009 	u32 au_seqno;
3010 	struct context au_ctxt;
3011 };
3012 
3013 void selinux_audit_rule_free(void *vrule)
3014 {
3015 	struct selinux_audit_rule *rule = vrule;
3016 
3017 	if (rule) {
3018 		context_destroy(&rule->au_ctxt);
3019 		kfree(rule);
3020 	}
3021 }
3022 
3023 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3024 {
3025 	struct selinux_audit_rule *tmprule;
3026 	struct role_datum *roledatum;
3027 	struct type_datum *typedatum;
3028 	struct user_datum *userdatum;
3029 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3030 	int rc = 0;
3031 
3032 	*rule = NULL;
3033 
3034 	if (!ss_initialized)
3035 		return -EOPNOTSUPP;
3036 
3037 	switch (field) {
3038 	case AUDIT_SUBJ_USER:
3039 	case AUDIT_SUBJ_ROLE:
3040 	case AUDIT_SUBJ_TYPE:
3041 	case AUDIT_OBJ_USER:
3042 	case AUDIT_OBJ_ROLE:
3043 	case AUDIT_OBJ_TYPE:
3044 		/* only 'equals' and 'not equals' fit user, role, and type */
3045 		if (op != Audit_equal && op != Audit_not_equal)
3046 			return -EINVAL;
3047 		break;
3048 	case AUDIT_SUBJ_SEN:
3049 	case AUDIT_SUBJ_CLR:
3050 	case AUDIT_OBJ_LEV_LOW:
3051 	case AUDIT_OBJ_LEV_HIGH:
3052 		/* we do not allow a range, indicated by the presence of '-' */
3053 		if (strchr(rulestr, '-'))
3054 			return -EINVAL;
3055 		break;
3056 	default:
3057 		/* only the above fields are valid */
3058 		return -EINVAL;
3059 	}
3060 
3061 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3062 	if (!tmprule)
3063 		return -ENOMEM;
3064 
3065 	context_init(&tmprule->au_ctxt);
3066 
3067 	read_lock(&policy_rwlock);
3068 
3069 	tmprule->au_seqno = latest_granting;
3070 
3071 	switch (field) {
3072 	case AUDIT_SUBJ_USER:
3073 	case AUDIT_OBJ_USER:
3074 		rc = -EINVAL;
3075 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
3076 		if (!userdatum)
3077 			goto out;
3078 		tmprule->au_ctxt.user = userdatum->value;
3079 		break;
3080 	case AUDIT_SUBJ_ROLE:
3081 	case AUDIT_OBJ_ROLE:
3082 		rc = -EINVAL;
3083 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3084 		if (!roledatum)
3085 			goto out;
3086 		tmprule->au_ctxt.role = roledatum->value;
3087 		break;
3088 	case AUDIT_SUBJ_TYPE:
3089 	case AUDIT_OBJ_TYPE:
3090 		rc = -EINVAL;
3091 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
3092 		if (!typedatum)
3093 			goto out;
3094 		tmprule->au_ctxt.type = typedatum->value;
3095 		break;
3096 	case AUDIT_SUBJ_SEN:
3097 	case AUDIT_SUBJ_CLR:
3098 	case AUDIT_OBJ_LEV_LOW:
3099 	case AUDIT_OBJ_LEV_HIGH:
3100 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3101 		if (rc)
3102 			goto out;
3103 		break;
3104 	}
3105 	rc = 0;
3106 out:
3107 	read_unlock(&policy_rwlock);
3108 
3109 	if (rc) {
3110 		selinux_audit_rule_free(tmprule);
3111 		tmprule = NULL;
3112 	}
3113 
3114 	*rule = tmprule;
3115 
3116 	return rc;
3117 }
3118 
3119 /* Check to see if the rule contains any selinux fields */
3120 int selinux_audit_rule_known(struct audit_krule *rule)
3121 {
3122 	int i;
3123 
3124 	for (i = 0; i < rule->field_count; i++) {
3125 		struct audit_field *f = &rule->fields[i];
3126 		switch (f->type) {
3127 		case AUDIT_SUBJ_USER:
3128 		case AUDIT_SUBJ_ROLE:
3129 		case AUDIT_SUBJ_TYPE:
3130 		case AUDIT_SUBJ_SEN:
3131 		case AUDIT_SUBJ_CLR:
3132 		case AUDIT_OBJ_USER:
3133 		case AUDIT_OBJ_ROLE:
3134 		case AUDIT_OBJ_TYPE:
3135 		case AUDIT_OBJ_LEV_LOW:
3136 		case AUDIT_OBJ_LEV_HIGH:
3137 			return 1;
3138 		}
3139 	}
3140 
3141 	return 0;
3142 }
3143 
3144 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3145 			     struct audit_context *actx)
3146 {
3147 	struct context *ctxt;
3148 	struct mls_level *level;
3149 	struct selinux_audit_rule *rule = vrule;
3150 	int match = 0;
3151 
3152 	if (unlikely(!rule)) {
3153 		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3154 		return -ENOENT;
3155 	}
3156 
3157 	read_lock(&policy_rwlock);
3158 
3159 	if (rule->au_seqno < latest_granting) {
3160 		match = -ESTALE;
3161 		goto out;
3162 	}
3163 
3164 	ctxt = sidtab_search(&sidtab, sid);
3165 	if (unlikely(!ctxt)) {
3166 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3167 			  sid);
3168 		match = -ENOENT;
3169 		goto out;
3170 	}
3171 
3172 	/* a field/op pair that is not caught here will simply fall through
3173 	   without a match */
3174 	switch (field) {
3175 	case AUDIT_SUBJ_USER:
3176 	case AUDIT_OBJ_USER:
3177 		switch (op) {
3178 		case Audit_equal:
3179 			match = (ctxt->user == rule->au_ctxt.user);
3180 			break;
3181 		case Audit_not_equal:
3182 			match = (ctxt->user != rule->au_ctxt.user);
3183 			break;
3184 		}
3185 		break;
3186 	case AUDIT_SUBJ_ROLE:
3187 	case AUDIT_OBJ_ROLE:
3188 		switch (op) {
3189 		case Audit_equal:
3190 			match = (ctxt->role == rule->au_ctxt.role);
3191 			break;
3192 		case Audit_not_equal:
3193 			match = (ctxt->role != rule->au_ctxt.role);
3194 			break;
3195 		}
3196 		break;
3197 	case AUDIT_SUBJ_TYPE:
3198 	case AUDIT_OBJ_TYPE:
3199 		switch (op) {
3200 		case Audit_equal:
3201 			match = (ctxt->type == rule->au_ctxt.type);
3202 			break;
3203 		case Audit_not_equal:
3204 			match = (ctxt->type != rule->au_ctxt.type);
3205 			break;
3206 		}
3207 		break;
3208 	case AUDIT_SUBJ_SEN:
3209 	case AUDIT_SUBJ_CLR:
3210 	case AUDIT_OBJ_LEV_LOW:
3211 	case AUDIT_OBJ_LEV_HIGH:
3212 		level = ((field == AUDIT_SUBJ_SEN ||
3213 			  field == AUDIT_OBJ_LEV_LOW) ?
3214 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3215 		switch (op) {
3216 		case Audit_equal:
3217 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3218 					     level);
3219 			break;
3220 		case Audit_not_equal:
3221 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3222 					      level);
3223 			break;
3224 		case Audit_lt:
3225 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3226 					       level) &&
3227 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3228 					       level));
3229 			break;
3230 		case Audit_le:
3231 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3232 					      level);
3233 			break;
3234 		case Audit_gt:
3235 			match = (mls_level_dom(level,
3236 					      &rule->au_ctxt.range.level[0]) &&
3237 				 !mls_level_eq(level,
3238 					       &rule->au_ctxt.range.level[0]));
3239 			break;
3240 		case Audit_ge:
3241 			match = mls_level_dom(level,
3242 					      &rule->au_ctxt.range.level[0]);
3243 			break;
3244 		}
3245 	}
3246 
3247 out:
3248 	read_unlock(&policy_rwlock);
3249 	return match;
3250 }
3251 
3252 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3253 
3254 static int aurule_avc_callback(u32 event)
3255 {
3256 	int err = 0;
3257 
3258 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3259 		err = aurule_callback();
3260 	return err;
3261 }
3262 
3263 static int __init aurule_init(void)
3264 {
3265 	int err;
3266 
3267 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3268 	if (err)
3269 		panic("avc_add_callback() failed, error %d\n", err);
3270 
3271 	return err;
3272 }
3273 __initcall(aurule_init);
3274 
3275 #ifdef CONFIG_NETLABEL
3276 /**
3277  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3278  * @secattr: the NetLabel packet security attributes
3279  * @sid: the SELinux SID
3280  *
3281  * Description:
3282  * Attempt to cache the context in @ctx, which was derived from the packet in
3283  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3284  * already been initialized.
3285  *
3286  */
3287 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3288 				      u32 sid)
3289 {
3290 	u32 *sid_cache;
3291 
3292 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3293 	if (sid_cache == NULL)
3294 		return;
3295 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3296 	if (secattr->cache == NULL) {
3297 		kfree(sid_cache);
3298 		return;
3299 	}
3300 
3301 	*sid_cache = sid;
3302 	secattr->cache->free = kfree;
3303 	secattr->cache->data = sid_cache;
3304 	secattr->flags |= NETLBL_SECATTR_CACHE;
3305 }
3306 
3307 /**
3308  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3309  * @secattr: the NetLabel packet security attributes
3310  * @sid: the SELinux SID
3311  *
3312  * Description:
3313  * Convert the given NetLabel security attributes in @secattr into a
3314  * SELinux SID.  If the @secattr field does not contain a full SELinux
3315  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3316  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3317  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3318  * conversion for future lookups.  Returns zero on success, negative values on
3319  * failure.
3320  *
3321  */
3322 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3323 				   u32 *sid)
3324 {
3325 	int rc;
3326 	struct context *ctx;
3327 	struct context ctx_new;
3328 
3329 	if (!ss_initialized) {
3330 		*sid = SECSID_NULL;
3331 		return 0;
3332 	}
3333 
3334 	read_lock(&policy_rwlock);
3335 
3336 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3337 		*sid = *(u32 *)secattr->cache->data;
3338 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3339 		*sid = secattr->attr.secid;
3340 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3341 		rc = -EIDRM;
3342 		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3343 		if (ctx == NULL)
3344 			goto out;
3345 
3346 		context_init(&ctx_new);
3347 		ctx_new.user = ctx->user;
3348 		ctx_new.role = ctx->role;
3349 		ctx_new.type = ctx->type;
3350 		mls_import_netlbl_lvl(&ctx_new, secattr);
3351 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3352 			rc = mls_import_netlbl_cat(&ctx_new, secattr);
3353 			if (rc)
3354 				goto out;
3355 		}
3356 		rc = -EIDRM;
3357 		if (!mls_context_isvalid(&policydb, &ctx_new))
3358 			goto out_free;
3359 
3360 		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3361 		if (rc)
3362 			goto out_free;
3363 
3364 		security_netlbl_cache_add(secattr, *sid);
3365 
3366 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3367 	} else
3368 		*sid = SECSID_NULL;
3369 
3370 	read_unlock(&policy_rwlock);
3371 	return 0;
3372 out_free:
3373 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3374 out:
3375 	read_unlock(&policy_rwlock);
3376 	return rc;
3377 }
3378 
3379 /**
3380  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3381  * @sid: the SELinux SID
3382  * @secattr: the NetLabel packet security attributes
3383  *
3384  * Description:
3385  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3386  * Returns zero on success, negative values on failure.
3387  *
3388  */
3389 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3390 {
3391 	int rc;
3392 	struct context *ctx;
3393 
3394 	if (!ss_initialized)
3395 		return 0;
3396 
3397 	read_lock(&policy_rwlock);
3398 
3399 	rc = -ENOENT;
3400 	ctx = sidtab_search(&sidtab, sid);
3401 	if (ctx == NULL)
3402 		goto out;
3403 
3404 	rc = -ENOMEM;
3405 	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3406 				  GFP_ATOMIC);
3407 	if (secattr->domain == NULL)
3408 		goto out;
3409 
3410 	secattr->attr.secid = sid;
3411 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3412 	mls_export_netlbl_lvl(ctx, secattr);
3413 	rc = mls_export_netlbl_cat(ctx, secattr);
3414 out:
3415 	read_unlock(&policy_rwlock);
3416 	return rc;
3417 }
3418 #endif /* CONFIG_NETLABEL */
3419 
3420 /**
3421  * security_read_policy - read the policy.
3422  * @data: binary policy data
3423  * @len: length of data in bytes
3424  *
3425  */
3426 int security_read_policy(void **data, size_t *len)
3427 {
3428 	int rc;
3429 	struct policy_file fp;
3430 
3431 	if (!ss_initialized)
3432 		return -EINVAL;
3433 
3434 	*len = security_policydb_len();
3435 
3436 	*data = vmalloc_user(*len);
3437 	if (!*data)
3438 		return -ENOMEM;
3439 
3440 	fp.data = *data;
3441 	fp.len = *len;
3442 
3443 	read_lock(&policy_rwlock);
3444 	rc = policydb_write(&policydb, &fp);
3445 	read_unlock(&policy_rwlock);
3446 
3447 	if (rc)
3448 		return rc;
3449 
3450 	*len = (unsigned long)fp.data - (unsigned long)*data;
3451 	return 0;
3452 
3453 }
3454