xref: /openbmc/linux/security/selinux/ss/services.c (revision a8da474e)
1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5  *	     James Morris <jmorris@redhat.com>
6  *
7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8  *
9  *	Support for enhanced MLS infrastructure.
10  *	Support for context based audit filters.
11  *
12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  *	Added conditional policy language extensions
15  *
16  * Updated: Hewlett-Packard <paul@paul-moore.com>
17  *
18  *      Added support for NetLabel
19  *      Added support for the policy capability bitmap
20  *
21  * Updated: Chad Sellers <csellers@tresys.com>
22  *
23  *  Added validation of kernel classes and permissions
24  *
25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26  *
27  *  Added support for bounds domain and audit messaged on masked permissions
28  *
29  * Updated: Guido Trentalancia <guido@trentalancia.com>
30  *
31  *  Added support for runtime switching of the policy type
32  *
33  * Copyright (C) 2008, 2009 NEC Corporation
34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38  *	This program is free software; you can redistribute it and/or modify
39  *	it under the terms of the GNU General Public License as published by
40  *	the Free Software Foundation, version 2.
41  */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56 
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72 
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76 
77 static DEFINE_RWLOCK(policy_rwlock);
78 
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82 
83 /*
84  * The largest sequence number that has been used when
85  * providing an access decision to the access vector cache.
86  * The sequence number only changes when a policy change
87  * occurs.
88  */
89 static u32 latest_granting;
90 
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 				    u32 *scontext_len);
94 
95 static void context_struct_compute_av(struct context *scontext,
96 					struct context *tcontext,
97 					u16 tclass,
98 					struct av_decision *avd,
99 					struct extended_perms *xperms);
100 
101 struct selinux_mapping {
102 	u16 value; /* policy value */
103 	unsigned num_perms;
104 	u32 perms[sizeof(u32) * 8];
105 };
106 
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109 
110 static int selinux_set_mapping(struct policydb *pol,
111 			       struct security_class_mapping *map,
112 			       struct selinux_mapping **out_map_p,
113 			       u16 *out_map_size)
114 {
115 	struct selinux_mapping *out_map = NULL;
116 	size_t size = sizeof(struct selinux_mapping);
117 	u16 i, j;
118 	unsigned k;
119 	bool print_unknown_handle = false;
120 
121 	/* Find number of classes in the input mapping */
122 	if (!map)
123 		return -EINVAL;
124 	i = 0;
125 	while (map[i].name)
126 		i++;
127 
128 	/* Allocate space for the class records, plus one for class zero */
129 	out_map = kcalloc(++i, size, GFP_ATOMIC);
130 	if (!out_map)
131 		return -ENOMEM;
132 
133 	/* Store the raw class and permission values */
134 	j = 0;
135 	while (map[j].name) {
136 		struct security_class_mapping *p_in = map + (j++);
137 		struct selinux_mapping *p_out = out_map + j;
138 
139 		/* An empty class string skips ahead */
140 		if (!strcmp(p_in->name, "")) {
141 			p_out->num_perms = 0;
142 			continue;
143 		}
144 
145 		p_out->value = string_to_security_class(pol, p_in->name);
146 		if (!p_out->value) {
147 			printk(KERN_INFO
148 			       "SELinux:  Class %s not defined in policy.\n",
149 			       p_in->name);
150 			if (pol->reject_unknown)
151 				goto err;
152 			p_out->num_perms = 0;
153 			print_unknown_handle = true;
154 			continue;
155 		}
156 
157 		k = 0;
158 		while (p_in->perms && p_in->perms[k]) {
159 			/* An empty permission string skips ahead */
160 			if (!*p_in->perms[k]) {
161 				k++;
162 				continue;
163 			}
164 			p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 							    p_in->perms[k]);
166 			if (!p_out->perms[k]) {
167 				printk(KERN_INFO
168 				       "SELinux:  Permission %s in class %s not defined in policy.\n",
169 				       p_in->perms[k], p_in->name);
170 				if (pol->reject_unknown)
171 					goto err;
172 				print_unknown_handle = true;
173 			}
174 
175 			k++;
176 		}
177 		p_out->num_perms = k;
178 	}
179 
180 	if (print_unknown_handle)
181 		printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 		       pol->allow_unknown ? "allowed" : "denied");
183 
184 	*out_map_p = out_map;
185 	*out_map_size = i;
186 	return 0;
187 err:
188 	kfree(out_map);
189 	return -EINVAL;
190 }
191 
192 /*
193  * Get real, policy values from mapped values
194  */
195 
196 static u16 unmap_class(u16 tclass)
197 {
198 	if (tclass < current_mapping_size)
199 		return current_mapping[tclass].value;
200 
201 	return tclass;
202 }
203 
204 /*
205  * Get kernel value for class from its policy value
206  */
207 static u16 map_class(u16 pol_value)
208 {
209 	u16 i;
210 
211 	for (i = 1; i < current_mapping_size; i++) {
212 		if (current_mapping[i].value == pol_value)
213 			return i;
214 	}
215 
216 	return SECCLASS_NULL;
217 }
218 
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 			 int allow_unknown)
221 {
222 	if (tclass < current_mapping_size) {
223 		unsigned i, n = current_mapping[tclass].num_perms;
224 		u32 result;
225 
226 		for (i = 0, result = 0; i < n; i++) {
227 			if (avd->allowed & current_mapping[tclass].perms[i])
228 				result |= 1<<i;
229 			if (allow_unknown && !current_mapping[tclass].perms[i])
230 				result |= 1<<i;
231 		}
232 		avd->allowed = result;
233 
234 		for (i = 0, result = 0; i < n; i++)
235 			if (avd->auditallow & current_mapping[tclass].perms[i])
236 				result |= 1<<i;
237 		avd->auditallow = result;
238 
239 		for (i = 0, result = 0; i < n; i++) {
240 			if (avd->auditdeny & current_mapping[tclass].perms[i])
241 				result |= 1<<i;
242 			if (!allow_unknown && !current_mapping[tclass].perms[i])
243 				result |= 1<<i;
244 		}
245 		/*
246 		 * In case the kernel has a bug and requests a permission
247 		 * between num_perms and the maximum permission number, we
248 		 * should audit that denial
249 		 */
250 		for (; i < (sizeof(u32)*8); i++)
251 			result |= 1<<i;
252 		avd->auditdeny = result;
253 	}
254 }
255 
256 int security_mls_enabled(void)
257 {
258 	return policydb.mls_enabled;
259 }
260 
261 /*
262  * Return the boolean value of a constraint expression
263  * when it is applied to the specified source and target
264  * security contexts.
265  *
266  * xcontext is a special beast...  It is used by the validatetrans rules
267  * only.  For these rules, scontext is the context before the transition,
268  * tcontext is the context after the transition, and xcontext is the context
269  * of the process performing the transition.  All other callers of
270  * constraint_expr_eval should pass in NULL for xcontext.
271  */
272 static int constraint_expr_eval(struct context *scontext,
273 				struct context *tcontext,
274 				struct context *xcontext,
275 				struct constraint_expr *cexpr)
276 {
277 	u32 val1, val2;
278 	struct context *c;
279 	struct role_datum *r1, *r2;
280 	struct mls_level *l1, *l2;
281 	struct constraint_expr *e;
282 	int s[CEXPR_MAXDEPTH];
283 	int sp = -1;
284 
285 	for (e = cexpr; e; e = e->next) {
286 		switch (e->expr_type) {
287 		case CEXPR_NOT:
288 			BUG_ON(sp < 0);
289 			s[sp] = !s[sp];
290 			break;
291 		case CEXPR_AND:
292 			BUG_ON(sp < 1);
293 			sp--;
294 			s[sp] &= s[sp + 1];
295 			break;
296 		case CEXPR_OR:
297 			BUG_ON(sp < 1);
298 			sp--;
299 			s[sp] |= s[sp + 1];
300 			break;
301 		case CEXPR_ATTR:
302 			if (sp == (CEXPR_MAXDEPTH - 1))
303 				return 0;
304 			switch (e->attr) {
305 			case CEXPR_USER:
306 				val1 = scontext->user;
307 				val2 = tcontext->user;
308 				break;
309 			case CEXPR_TYPE:
310 				val1 = scontext->type;
311 				val2 = tcontext->type;
312 				break;
313 			case CEXPR_ROLE:
314 				val1 = scontext->role;
315 				val2 = tcontext->role;
316 				r1 = policydb.role_val_to_struct[val1 - 1];
317 				r2 = policydb.role_val_to_struct[val2 - 1];
318 				switch (e->op) {
319 				case CEXPR_DOM:
320 					s[++sp] = ebitmap_get_bit(&r1->dominates,
321 								  val2 - 1);
322 					continue;
323 				case CEXPR_DOMBY:
324 					s[++sp] = ebitmap_get_bit(&r2->dominates,
325 								  val1 - 1);
326 					continue;
327 				case CEXPR_INCOMP:
328 					s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 								    val2 - 1) &&
330 						   !ebitmap_get_bit(&r2->dominates,
331 								    val1 - 1));
332 					continue;
333 				default:
334 					break;
335 				}
336 				break;
337 			case CEXPR_L1L2:
338 				l1 = &(scontext->range.level[0]);
339 				l2 = &(tcontext->range.level[0]);
340 				goto mls_ops;
341 			case CEXPR_L1H2:
342 				l1 = &(scontext->range.level[0]);
343 				l2 = &(tcontext->range.level[1]);
344 				goto mls_ops;
345 			case CEXPR_H1L2:
346 				l1 = &(scontext->range.level[1]);
347 				l2 = &(tcontext->range.level[0]);
348 				goto mls_ops;
349 			case CEXPR_H1H2:
350 				l1 = &(scontext->range.level[1]);
351 				l2 = &(tcontext->range.level[1]);
352 				goto mls_ops;
353 			case CEXPR_L1H1:
354 				l1 = &(scontext->range.level[0]);
355 				l2 = &(scontext->range.level[1]);
356 				goto mls_ops;
357 			case CEXPR_L2H2:
358 				l1 = &(tcontext->range.level[0]);
359 				l2 = &(tcontext->range.level[1]);
360 				goto mls_ops;
361 mls_ops:
362 			switch (e->op) {
363 			case CEXPR_EQ:
364 				s[++sp] = mls_level_eq(l1, l2);
365 				continue;
366 			case CEXPR_NEQ:
367 				s[++sp] = !mls_level_eq(l1, l2);
368 				continue;
369 			case CEXPR_DOM:
370 				s[++sp] = mls_level_dom(l1, l2);
371 				continue;
372 			case CEXPR_DOMBY:
373 				s[++sp] = mls_level_dom(l2, l1);
374 				continue;
375 			case CEXPR_INCOMP:
376 				s[++sp] = mls_level_incomp(l2, l1);
377 				continue;
378 			default:
379 				BUG();
380 				return 0;
381 			}
382 			break;
383 			default:
384 				BUG();
385 				return 0;
386 			}
387 
388 			switch (e->op) {
389 			case CEXPR_EQ:
390 				s[++sp] = (val1 == val2);
391 				break;
392 			case CEXPR_NEQ:
393 				s[++sp] = (val1 != val2);
394 				break;
395 			default:
396 				BUG();
397 				return 0;
398 			}
399 			break;
400 		case CEXPR_NAMES:
401 			if (sp == (CEXPR_MAXDEPTH-1))
402 				return 0;
403 			c = scontext;
404 			if (e->attr & CEXPR_TARGET)
405 				c = tcontext;
406 			else if (e->attr & CEXPR_XTARGET) {
407 				c = xcontext;
408 				if (!c) {
409 					BUG();
410 					return 0;
411 				}
412 			}
413 			if (e->attr & CEXPR_USER)
414 				val1 = c->user;
415 			else if (e->attr & CEXPR_ROLE)
416 				val1 = c->role;
417 			else if (e->attr & CEXPR_TYPE)
418 				val1 = c->type;
419 			else {
420 				BUG();
421 				return 0;
422 			}
423 
424 			switch (e->op) {
425 			case CEXPR_EQ:
426 				s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 				break;
428 			case CEXPR_NEQ:
429 				s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 				break;
431 			default:
432 				BUG();
433 				return 0;
434 			}
435 			break;
436 		default:
437 			BUG();
438 			return 0;
439 		}
440 	}
441 
442 	BUG_ON(sp != 0);
443 	return s[0];
444 }
445 
446 /*
447  * security_dump_masked_av - dumps masked permissions during
448  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449  */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 	struct perm_datum *pdatum = d;
453 	char **permission_names = args;
454 
455 	BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456 
457 	permission_names[pdatum->value - 1] = (char *)k;
458 
459 	return 0;
460 }
461 
462 static void security_dump_masked_av(struct context *scontext,
463 				    struct context *tcontext,
464 				    u16 tclass,
465 				    u32 permissions,
466 				    const char *reason)
467 {
468 	struct common_datum *common_dat;
469 	struct class_datum *tclass_dat;
470 	struct audit_buffer *ab;
471 	char *tclass_name;
472 	char *scontext_name = NULL;
473 	char *tcontext_name = NULL;
474 	char *permission_names[32];
475 	int index;
476 	u32 length;
477 	bool need_comma = false;
478 
479 	if (!permissions)
480 		return;
481 
482 	tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 	tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 	common_dat = tclass_dat->comdatum;
485 
486 	/* init permission_names */
487 	if (common_dat &&
488 	    hashtab_map(common_dat->permissions.table,
489 			dump_masked_av_helper, permission_names) < 0)
490 		goto out;
491 
492 	if (hashtab_map(tclass_dat->permissions.table,
493 			dump_masked_av_helper, permission_names) < 0)
494 		goto out;
495 
496 	/* get scontext/tcontext in text form */
497 	if (context_struct_to_string(scontext,
498 				     &scontext_name, &length) < 0)
499 		goto out;
500 
501 	if (context_struct_to_string(tcontext,
502 				     &tcontext_name, &length) < 0)
503 		goto out;
504 
505 	/* audit a message */
506 	ab = audit_log_start(current->audit_context,
507 			     GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 	if (!ab)
509 		goto out;
510 
511 	audit_log_format(ab, "op=security_compute_av reason=%s "
512 			 "scontext=%s tcontext=%s tclass=%s perms=",
513 			 reason, scontext_name, tcontext_name, tclass_name);
514 
515 	for (index = 0; index < 32; index++) {
516 		u32 mask = (1 << index);
517 
518 		if ((mask & permissions) == 0)
519 			continue;
520 
521 		audit_log_format(ab, "%s%s",
522 				 need_comma ? "," : "",
523 				 permission_names[index]
524 				 ? permission_names[index] : "????");
525 		need_comma = true;
526 	}
527 	audit_log_end(ab);
528 out:
529 	/* release scontext/tcontext */
530 	kfree(tcontext_name);
531 	kfree(scontext_name);
532 
533 	return;
534 }
535 
536 /*
537  * security_boundary_permission - drops violated permissions
538  * on boundary constraint.
539  */
540 static void type_attribute_bounds_av(struct context *scontext,
541 				     struct context *tcontext,
542 				     u16 tclass,
543 				     struct av_decision *avd)
544 {
545 	struct context lo_scontext;
546 	struct context lo_tcontext;
547 	struct av_decision lo_avd;
548 	struct type_datum *source;
549 	struct type_datum *target;
550 	u32 masked = 0;
551 
552 	source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 				    scontext->type - 1);
554 	BUG_ON(!source);
555 
556 	target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557 				    tcontext->type - 1);
558 	BUG_ON(!target);
559 
560 	if (source->bounds) {
561 		memset(&lo_avd, 0, sizeof(lo_avd));
562 
563 		memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564 		lo_scontext.type = source->bounds;
565 
566 		context_struct_compute_av(&lo_scontext,
567 					  tcontext,
568 					  tclass,
569 					  &lo_avd,
570 					  NULL);
571 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
572 			return;		/* no masked permission */
573 		masked = ~lo_avd.allowed & avd->allowed;
574 	}
575 
576 	if (target->bounds) {
577 		memset(&lo_avd, 0, sizeof(lo_avd));
578 
579 		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
580 		lo_tcontext.type = target->bounds;
581 
582 		context_struct_compute_av(scontext,
583 					  &lo_tcontext,
584 					  tclass,
585 					  &lo_avd,
586 					  NULL);
587 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
588 			return;		/* no masked permission */
589 		masked = ~lo_avd.allowed & avd->allowed;
590 	}
591 
592 	if (source->bounds && target->bounds) {
593 		memset(&lo_avd, 0, sizeof(lo_avd));
594 		/*
595 		 * lo_scontext and lo_tcontext are already
596 		 * set up.
597 		 */
598 
599 		context_struct_compute_av(&lo_scontext,
600 					  &lo_tcontext,
601 					  tclass,
602 					  &lo_avd,
603 					  NULL);
604 		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
605 			return;		/* no masked permission */
606 		masked = ~lo_avd.allowed & avd->allowed;
607 	}
608 
609 	if (masked) {
610 		/* mask violated permissions */
611 		avd->allowed &= ~masked;
612 
613 		/* audit masked permissions */
614 		security_dump_masked_av(scontext, tcontext,
615 					tclass, masked, "bounds");
616 	}
617 }
618 
619 /*
620  * flag which drivers have permissions
621  * only looking for ioctl based extended permssions
622  */
623 void services_compute_xperms_drivers(
624 		struct extended_perms *xperms,
625 		struct avtab_node *node)
626 {
627 	unsigned int i;
628 
629 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
630 		/* if one or more driver has all permissions allowed */
631 		for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
632 			xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
633 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
634 		/* if allowing permissions within a driver */
635 		security_xperm_set(xperms->drivers.p,
636 					node->datum.u.xperms->driver);
637 	}
638 
639 	/* If no ioctl commands are allowed, ignore auditallow and auditdeny */
640 	if (node->key.specified & AVTAB_XPERMS_ALLOWED)
641 		xperms->len = 1;
642 }
643 
644 /*
645  * Compute access vectors and extended permissions based on a context
646  * structure pair for the permissions in a particular class.
647  */
648 static void context_struct_compute_av(struct context *scontext,
649 					struct context *tcontext,
650 					u16 tclass,
651 					struct av_decision *avd,
652 					struct extended_perms *xperms)
653 {
654 	struct constraint_node *constraint;
655 	struct role_allow *ra;
656 	struct avtab_key avkey;
657 	struct avtab_node *node;
658 	struct class_datum *tclass_datum;
659 	struct ebitmap *sattr, *tattr;
660 	struct ebitmap_node *snode, *tnode;
661 	unsigned int i, j;
662 
663 	avd->allowed = 0;
664 	avd->auditallow = 0;
665 	avd->auditdeny = 0xffffffff;
666 	if (xperms) {
667 		memset(&xperms->drivers, 0, sizeof(xperms->drivers));
668 		xperms->len = 0;
669 	}
670 
671 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
672 		if (printk_ratelimit())
673 			printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
674 		return;
675 	}
676 
677 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
678 
679 	/*
680 	 * If a specific type enforcement rule was defined for
681 	 * this permission check, then use it.
682 	 */
683 	avkey.target_class = tclass;
684 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
685 	sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
686 	BUG_ON(!sattr);
687 	tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
688 	BUG_ON(!tattr);
689 	ebitmap_for_each_positive_bit(sattr, snode, i) {
690 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
691 			avkey.source_type = i + 1;
692 			avkey.target_type = j + 1;
693 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
694 			     node;
695 			     node = avtab_search_node_next(node, avkey.specified)) {
696 				if (node->key.specified == AVTAB_ALLOWED)
697 					avd->allowed |= node->datum.u.data;
698 				else if (node->key.specified == AVTAB_AUDITALLOW)
699 					avd->auditallow |= node->datum.u.data;
700 				else if (node->key.specified == AVTAB_AUDITDENY)
701 					avd->auditdeny &= node->datum.u.data;
702 				else if (xperms && (node->key.specified & AVTAB_XPERMS))
703 					services_compute_xperms_drivers(xperms, node);
704 			}
705 
706 			/* Check conditional av table for additional permissions */
707 			cond_compute_av(&policydb.te_cond_avtab, &avkey,
708 					avd, xperms);
709 
710 		}
711 	}
712 
713 	/*
714 	 * Remove any permissions prohibited by a constraint (this includes
715 	 * the MLS policy).
716 	 */
717 	constraint = tclass_datum->constraints;
718 	while (constraint) {
719 		if ((constraint->permissions & (avd->allowed)) &&
720 		    !constraint_expr_eval(scontext, tcontext, NULL,
721 					  constraint->expr)) {
722 			avd->allowed &= ~(constraint->permissions);
723 		}
724 		constraint = constraint->next;
725 	}
726 
727 	/*
728 	 * If checking process transition permission and the
729 	 * role is changing, then check the (current_role, new_role)
730 	 * pair.
731 	 */
732 	if (tclass == policydb.process_class &&
733 	    (avd->allowed & policydb.process_trans_perms) &&
734 	    scontext->role != tcontext->role) {
735 		for (ra = policydb.role_allow; ra; ra = ra->next) {
736 			if (scontext->role == ra->role &&
737 			    tcontext->role == ra->new_role)
738 				break;
739 		}
740 		if (!ra)
741 			avd->allowed &= ~policydb.process_trans_perms;
742 	}
743 
744 	/*
745 	 * If the given source and target types have boundary
746 	 * constraint, lazy checks have to mask any violated
747 	 * permission and notice it to userspace via audit.
748 	 */
749 	type_attribute_bounds_av(scontext, tcontext,
750 				 tclass, avd);
751 }
752 
753 static int security_validtrans_handle_fail(struct context *ocontext,
754 					   struct context *ncontext,
755 					   struct context *tcontext,
756 					   u16 tclass)
757 {
758 	char *o = NULL, *n = NULL, *t = NULL;
759 	u32 olen, nlen, tlen;
760 
761 	if (context_struct_to_string(ocontext, &o, &olen))
762 		goto out;
763 	if (context_struct_to_string(ncontext, &n, &nlen))
764 		goto out;
765 	if (context_struct_to_string(tcontext, &t, &tlen))
766 		goto out;
767 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
768 		  "op=security_validate_transition seresult=denied"
769 		  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
770 		  o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
771 out:
772 	kfree(o);
773 	kfree(n);
774 	kfree(t);
775 
776 	if (!selinux_enforcing)
777 		return 0;
778 	return -EPERM;
779 }
780 
781 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
782 				 u16 orig_tclass)
783 {
784 	struct context *ocontext;
785 	struct context *ncontext;
786 	struct context *tcontext;
787 	struct class_datum *tclass_datum;
788 	struct constraint_node *constraint;
789 	u16 tclass;
790 	int rc = 0;
791 
792 	if (!ss_initialized)
793 		return 0;
794 
795 	read_lock(&policy_rwlock);
796 
797 	tclass = unmap_class(orig_tclass);
798 
799 	if (!tclass || tclass > policydb.p_classes.nprim) {
800 		printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
801 			__func__, tclass);
802 		rc = -EINVAL;
803 		goto out;
804 	}
805 	tclass_datum = policydb.class_val_to_struct[tclass - 1];
806 
807 	ocontext = sidtab_search(&sidtab, oldsid);
808 	if (!ocontext) {
809 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
810 			__func__, oldsid);
811 		rc = -EINVAL;
812 		goto out;
813 	}
814 
815 	ncontext = sidtab_search(&sidtab, newsid);
816 	if (!ncontext) {
817 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
818 			__func__, newsid);
819 		rc = -EINVAL;
820 		goto out;
821 	}
822 
823 	tcontext = sidtab_search(&sidtab, tasksid);
824 	if (!tcontext) {
825 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
826 			__func__, tasksid);
827 		rc = -EINVAL;
828 		goto out;
829 	}
830 
831 	constraint = tclass_datum->validatetrans;
832 	while (constraint) {
833 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
834 					  constraint->expr)) {
835 			rc = security_validtrans_handle_fail(ocontext, ncontext,
836 							     tcontext, tclass);
837 			goto out;
838 		}
839 		constraint = constraint->next;
840 	}
841 
842 out:
843 	read_unlock(&policy_rwlock);
844 	return rc;
845 }
846 
847 /*
848  * security_bounded_transition - check whether the given
849  * transition is directed to bounded, or not.
850  * It returns 0, if @newsid is bounded by @oldsid.
851  * Otherwise, it returns error code.
852  *
853  * @oldsid : current security identifier
854  * @newsid : destinated security identifier
855  */
856 int security_bounded_transition(u32 old_sid, u32 new_sid)
857 {
858 	struct context *old_context, *new_context;
859 	struct type_datum *type;
860 	int index;
861 	int rc;
862 
863 	read_lock(&policy_rwlock);
864 
865 	rc = -EINVAL;
866 	old_context = sidtab_search(&sidtab, old_sid);
867 	if (!old_context) {
868 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
869 		       __func__, old_sid);
870 		goto out;
871 	}
872 
873 	rc = -EINVAL;
874 	new_context = sidtab_search(&sidtab, new_sid);
875 	if (!new_context) {
876 		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
877 		       __func__, new_sid);
878 		goto out;
879 	}
880 
881 	rc = 0;
882 	/* type/domain unchanged */
883 	if (old_context->type == new_context->type)
884 		goto out;
885 
886 	index = new_context->type;
887 	while (true) {
888 		type = flex_array_get_ptr(policydb.type_val_to_struct_array,
889 					  index - 1);
890 		BUG_ON(!type);
891 
892 		/* not bounded anymore */
893 		rc = -EPERM;
894 		if (!type->bounds)
895 			break;
896 
897 		/* @newsid is bounded by @oldsid */
898 		rc = 0;
899 		if (type->bounds == old_context->type)
900 			break;
901 
902 		index = type->bounds;
903 	}
904 
905 	if (rc) {
906 		char *old_name = NULL;
907 		char *new_name = NULL;
908 		u32 length;
909 
910 		if (!context_struct_to_string(old_context,
911 					      &old_name, &length) &&
912 		    !context_struct_to_string(new_context,
913 					      &new_name, &length)) {
914 			audit_log(current->audit_context,
915 				  GFP_ATOMIC, AUDIT_SELINUX_ERR,
916 				  "op=security_bounded_transition "
917 				  "seresult=denied "
918 				  "oldcontext=%s newcontext=%s",
919 				  old_name, new_name);
920 		}
921 		kfree(new_name);
922 		kfree(old_name);
923 	}
924 out:
925 	read_unlock(&policy_rwlock);
926 
927 	return rc;
928 }
929 
930 static void avd_init(struct av_decision *avd)
931 {
932 	avd->allowed = 0;
933 	avd->auditallow = 0;
934 	avd->auditdeny = 0xffffffff;
935 	avd->seqno = latest_granting;
936 	avd->flags = 0;
937 }
938 
939 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
940 					struct avtab_node *node)
941 {
942 	unsigned int i;
943 
944 	if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
945 		if (xpermd->driver != node->datum.u.xperms->driver)
946 			return;
947 	} else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
948 		if (!security_xperm_test(node->datum.u.xperms->perms.p,
949 					xpermd->driver))
950 			return;
951 	} else {
952 		BUG();
953 	}
954 
955 	if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
956 		xpermd->used |= XPERMS_ALLOWED;
957 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
958 			memset(xpermd->allowed->p, 0xff,
959 					sizeof(xpermd->allowed->p));
960 		}
961 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
962 			for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
963 				xpermd->allowed->p[i] |=
964 					node->datum.u.xperms->perms.p[i];
965 		}
966 	} else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
967 		xpermd->used |= XPERMS_AUDITALLOW;
968 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
969 			memset(xpermd->auditallow->p, 0xff,
970 					sizeof(xpermd->auditallow->p));
971 		}
972 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
973 			for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
974 				xpermd->auditallow->p[i] |=
975 					node->datum.u.xperms->perms.p[i];
976 		}
977 	} else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
978 		xpermd->used |= XPERMS_DONTAUDIT;
979 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
980 			memset(xpermd->dontaudit->p, 0xff,
981 					sizeof(xpermd->dontaudit->p));
982 		}
983 		if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
984 			for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
985 				xpermd->dontaudit->p[i] |=
986 					node->datum.u.xperms->perms.p[i];
987 		}
988 	} else {
989 		BUG();
990 	}
991 }
992 
993 void security_compute_xperms_decision(u32 ssid,
994 				u32 tsid,
995 				u16 orig_tclass,
996 				u8 driver,
997 				struct extended_perms_decision *xpermd)
998 {
999 	u16 tclass;
1000 	struct context *scontext, *tcontext;
1001 	struct avtab_key avkey;
1002 	struct avtab_node *node;
1003 	struct ebitmap *sattr, *tattr;
1004 	struct ebitmap_node *snode, *tnode;
1005 	unsigned int i, j;
1006 
1007 	xpermd->driver = driver;
1008 	xpermd->used = 0;
1009 	memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1010 	memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1011 	memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1012 
1013 	read_lock(&policy_rwlock);
1014 	if (!ss_initialized)
1015 		goto allow;
1016 
1017 	scontext = sidtab_search(&sidtab, ssid);
1018 	if (!scontext) {
1019 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1020 		       __func__, ssid);
1021 		goto out;
1022 	}
1023 
1024 	tcontext = sidtab_search(&sidtab, tsid);
1025 	if (!tcontext) {
1026 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1027 		       __func__, tsid);
1028 		goto out;
1029 	}
1030 
1031 	tclass = unmap_class(orig_tclass);
1032 	if (unlikely(orig_tclass && !tclass)) {
1033 		if (policydb.allow_unknown)
1034 			goto allow;
1035 		goto out;
1036 	}
1037 
1038 
1039 	if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1040 		pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1041 		goto out;
1042 	}
1043 
1044 	avkey.target_class = tclass;
1045 	avkey.specified = AVTAB_XPERMS;
1046 	sattr = flex_array_get(policydb.type_attr_map_array,
1047 				scontext->type - 1);
1048 	BUG_ON(!sattr);
1049 	tattr = flex_array_get(policydb.type_attr_map_array,
1050 				tcontext->type - 1);
1051 	BUG_ON(!tattr);
1052 	ebitmap_for_each_positive_bit(sattr, snode, i) {
1053 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
1054 			avkey.source_type = i + 1;
1055 			avkey.target_type = j + 1;
1056 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1057 			     node;
1058 			     node = avtab_search_node_next(node, avkey.specified))
1059 				services_compute_xperms_decision(xpermd, node);
1060 
1061 			cond_compute_xperms(&policydb.te_cond_avtab,
1062 						&avkey, xpermd);
1063 		}
1064 	}
1065 out:
1066 	read_unlock(&policy_rwlock);
1067 	return;
1068 allow:
1069 	memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1070 	goto out;
1071 }
1072 
1073 /**
1074  * security_compute_av - Compute access vector decisions.
1075  * @ssid: source security identifier
1076  * @tsid: target security identifier
1077  * @tclass: target security class
1078  * @avd: access vector decisions
1079  * @xperms: extended permissions
1080  *
1081  * Compute a set of access vector decisions based on the
1082  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1083  */
1084 void security_compute_av(u32 ssid,
1085 			 u32 tsid,
1086 			 u16 orig_tclass,
1087 			 struct av_decision *avd,
1088 			 struct extended_perms *xperms)
1089 {
1090 	u16 tclass;
1091 	struct context *scontext = NULL, *tcontext = NULL;
1092 
1093 	read_lock(&policy_rwlock);
1094 	avd_init(avd);
1095 	xperms->len = 0;
1096 	if (!ss_initialized)
1097 		goto allow;
1098 
1099 	scontext = sidtab_search(&sidtab, ssid);
1100 	if (!scontext) {
1101 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1102 		       __func__, ssid);
1103 		goto out;
1104 	}
1105 
1106 	/* permissive domain? */
1107 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1108 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1109 
1110 	tcontext = sidtab_search(&sidtab, tsid);
1111 	if (!tcontext) {
1112 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1113 		       __func__, tsid);
1114 		goto out;
1115 	}
1116 
1117 	tclass = unmap_class(orig_tclass);
1118 	if (unlikely(orig_tclass && !tclass)) {
1119 		if (policydb.allow_unknown)
1120 			goto allow;
1121 		goto out;
1122 	}
1123 	context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1124 	map_decision(orig_tclass, avd, policydb.allow_unknown);
1125 out:
1126 	read_unlock(&policy_rwlock);
1127 	return;
1128 allow:
1129 	avd->allowed = 0xffffffff;
1130 	goto out;
1131 }
1132 
1133 void security_compute_av_user(u32 ssid,
1134 			      u32 tsid,
1135 			      u16 tclass,
1136 			      struct av_decision *avd)
1137 {
1138 	struct context *scontext = NULL, *tcontext = NULL;
1139 
1140 	read_lock(&policy_rwlock);
1141 	avd_init(avd);
1142 	if (!ss_initialized)
1143 		goto allow;
1144 
1145 	scontext = sidtab_search(&sidtab, ssid);
1146 	if (!scontext) {
1147 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1148 		       __func__, ssid);
1149 		goto out;
1150 	}
1151 
1152 	/* permissive domain? */
1153 	if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1154 		avd->flags |= AVD_FLAGS_PERMISSIVE;
1155 
1156 	tcontext = sidtab_search(&sidtab, tsid);
1157 	if (!tcontext) {
1158 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1159 		       __func__, tsid);
1160 		goto out;
1161 	}
1162 
1163 	if (unlikely(!tclass)) {
1164 		if (policydb.allow_unknown)
1165 			goto allow;
1166 		goto out;
1167 	}
1168 
1169 	context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1170  out:
1171 	read_unlock(&policy_rwlock);
1172 	return;
1173 allow:
1174 	avd->allowed = 0xffffffff;
1175 	goto out;
1176 }
1177 
1178 /*
1179  * Write the security context string representation of
1180  * the context structure `context' into a dynamically
1181  * allocated string of the correct size.  Set `*scontext'
1182  * to point to this string and set `*scontext_len' to
1183  * the length of the string.
1184  */
1185 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1186 {
1187 	char *scontextp;
1188 
1189 	if (scontext)
1190 		*scontext = NULL;
1191 	*scontext_len = 0;
1192 
1193 	if (context->len) {
1194 		*scontext_len = context->len;
1195 		if (scontext) {
1196 			*scontext = kstrdup(context->str, GFP_ATOMIC);
1197 			if (!(*scontext))
1198 				return -ENOMEM;
1199 		}
1200 		return 0;
1201 	}
1202 
1203 	/* Compute the size of the context. */
1204 	*scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1205 	*scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1206 	*scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1207 	*scontext_len += mls_compute_context_len(context);
1208 
1209 	if (!scontext)
1210 		return 0;
1211 
1212 	/* Allocate space for the context; caller must free this space. */
1213 	scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1214 	if (!scontextp)
1215 		return -ENOMEM;
1216 	*scontext = scontextp;
1217 
1218 	/*
1219 	 * Copy the user name, role name and type name into the context.
1220 	 */
1221 	scontextp += sprintf(scontextp, "%s:%s:%s",
1222 		sym_name(&policydb, SYM_USERS, context->user - 1),
1223 		sym_name(&policydb, SYM_ROLES, context->role - 1),
1224 		sym_name(&policydb, SYM_TYPES, context->type - 1));
1225 
1226 	mls_sid_to_context(context, &scontextp);
1227 
1228 	*scontextp = 0;
1229 
1230 	return 0;
1231 }
1232 
1233 #include "initial_sid_to_string.h"
1234 
1235 const char *security_get_initial_sid_context(u32 sid)
1236 {
1237 	if (unlikely(sid > SECINITSID_NUM))
1238 		return NULL;
1239 	return initial_sid_to_string[sid];
1240 }
1241 
1242 static int security_sid_to_context_core(u32 sid, char **scontext,
1243 					u32 *scontext_len, int force)
1244 {
1245 	struct context *context;
1246 	int rc = 0;
1247 
1248 	if (scontext)
1249 		*scontext = NULL;
1250 	*scontext_len  = 0;
1251 
1252 	if (!ss_initialized) {
1253 		if (sid <= SECINITSID_NUM) {
1254 			char *scontextp;
1255 
1256 			*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1257 			if (!scontext)
1258 				goto out;
1259 			scontextp = kmemdup(initial_sid_to_string[sid],
1260 					    *scontext_len, GFP_ATOMIC);
1261 			if (!scontextp) {
1262 				rc = -ENOMEM;
1263 				goto out;
1264 			}
1265 			*scontext = scontextp;
1266 			goto out;
1267 		}
1268 		printk(KERN_ERR "SELinux: %s:  called before initial "
1269 		       "load_policy on unknown SID %d\n", __func__, sid);
1270 		rc = -EINVAL;
1271 		goto out;
1272 	}
1273 	read_lock(&policy_rwlock);
1274 	if (force)
1275 		context = sidtab_search_force(&sidtab, sid);
1276 	else
1277 		context = sidtab_search(&sidtab, sid);
1278 	if (!context) {
1279 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1280 			__func__, sid);
1281 		rc = -EINVAL;
1282 		goto out_unlock;
1283 	}
1284 	rc = context_struct_to_string(context, scontext, scontext_len);
1285 out_unlock:
1286 	read_unlock(&policy_rwlock);
1287 out:
1288 	return rc;
1289 
1290 }
1291 
1292 /**
1293  * security_sid_to_context - Obtain a context for a given SID.
1294  * @sid: security identifier, SID
1295  * @scontext: security context
1296  * @scontext_len: length in bytes
1297  *
1298  * Write the string representation of the context associated with @sid
1299  * into a dynamically allocated string of the correct size.  Set @scontext
1300  * to point to this string and set @scontext_len to the length of the string.
1301  */
1302 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1303 {
1304 	return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1305 }
1306 
1307 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1308 {
1309 	return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1310 }
1311 
1312 /*
1313  * Caveat:  Mutates scontext.
1314  */
1315 static int string_to_context_struct(struct policydb *pol,
1316 				    struct sidtab *sidtabp,
1317 				    char *scontext,
1318 				    u32 scontext_len,
1319 				    struct context *ctx,
1320 				    u32 def_sid)
1321 {
1322 	struct role_datum *role;
1323 	struct type_datum *typdatum;
1324 	struct user_datum *usrdatum;
1325 	char *scontextp, *p, oldc;
1326 	int rc = 0;
1327 
1328 	context_init(ctx);
1329 
1330 	/* Parse the security context. */
1331 
1332 	rc = -EINVAL;
1333 	scontextp = (char *) scontext;
1334 
1335 	/* Extract the user. */
1336 	p = scontextp;
1337 	while (*p && *p != ':')
1338 		p++;
1339 
1340 	if (*p == 0)
1341 		goto out;
1342 
1343 	*p++ = 0;
1344 
1345 	usrdatum = hashtab_search(pol->p_users.table, scontextp);
1346 	if (!usrdatum)
1347 		goto out;
1348 
1349 	ctx->user = usrdatum->value;
1350 
1351 	/* Extract role. */
1352 	scontextp = p;
1353 	while (*p && *p != ':')
1354 		p++;
1355 
1356 	if (*p == 0)
1357 		goto out;
1358 
1359 	*p++ = 0;
1360 
1361 	role = hashtab_search(pol->p_roles.table, scontextp);
1362 	if (!role)
1363 		goto out;
1364 	ctx->role = role->value;
1365 
1366 	/* Extract type. */
1367 	scontextp = p;
1368 	while (*p && *p != ':')
1369 		p++;
1370 	oldc = *p;
1371 	*p++ = 0;
1372 
1373 	typdatum = hashtab_search(pol->p_types.table, scontextp);
1374 	if (!typdatum || typdatum->attribute)
1375 		goto out;
1376 
1377 	ctx->type = typdatum->value;
1378 
1379 	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1380 	if (rc)
1381 		goto out;
1382 
1383 	rc = -EINVAL;
1384 	if ((p - scontext) < scontext_len)
1385 		goto out;
1386 
1387 	/* Check the validity of the new context. */
1388 	if (!policydb_context_isvalid(pol, ctx))
1389 		goto out;
1390 	rc = 0;
1391 out:
1392 	if (rc)
1393 		context_destroy(ctx);
1394 	return rc;
1395 }
1396 
1397 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1398 					u32 *sid, u32 def_sid, gfp_t gfp_flags,
1399 					int force)
1400 {
1401 	char *scontext2, *str = NULL;
1402 	struct context context;
1403 	int rc = 0;
1404 
1405 	/* An empty security context is never valid. */
1406 	if (!scontext_len)
1407 		return -EINVAL;
1408 
1409 	if (!ss_initialized) {
1410 		int i;
1411 
1412 		for (i = 1; i < SECINITSID_NUM; i++) {
1413 			if (!strcmp(initial_sid_to_string[i], scontext)) {
1414 				*sid = i;
1415 				return 0;
1416 			}
1417 		}
1418 		*sid = SECINITSID_KERNEL;
1419 		return 0;
1420 	}
1421 	*sid = SECSID_NULL;
1422 
1423 	/* Copy the string so that we can modify the copy as we parse it. */
1424 	scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1425 	if (!scontext2)
1426 		return -ENOMEM;
1427 	memcpy(scontext2, scontext, scontext_len);
1428 	scontext2[scontext_len] = 0;
1429 
1430 	if (force) {
1431 		/* Save another copy for storing in uninterpreted form */
1432 		rc = -ENOMEM;
1433 		str = kstrdup(scontext2, gfp_flags);
1434 		if (!str)
1435 			goto out;
1436 	}
1437 
1438 	read_lock(&policy_rwlock);
1439 	rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1440 				      scontext_len, &context, def_sid);
1441 	if (rc == -EINVAL && force) {
1442 		context.str = str;
1443 		context.len = scontext_len;
1444 		str = NULL;
1445 	} else if (rc)
1446 		goto out_unlock;
1447 	rc = sidtab_context_to_sid(&sidtab, &context, sid);
1448 	context_destroy(&context);
1449 out_unlock:
1450 	read_unlock(&policy_rwlock);
1451 out:
1452 	kfree(scontext2);
1453 	kfree(str);
1454 	return rc;
1455 }
1456 
1457 /**
1458  * security_context_to_sid - Obtain a SID for a given security context.
1459  * @scontext: security context
1460  * @scontext_len: length in bytes
1461  * @sid: security identifier, SID
1462  * @gfp: context for the allocation
1463  *
1464  * Obtains a SID associated with the security context that
1465  * has the string representation specified by @scontext.
1466  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1467  * memory is available, or 0 on success.
1468  */
1469 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1470 			    gfp_t gfp)
1471 {
1472 	return security_context_to_sid_core(scontext, scontext_len,
1473 					    sid, SECSID_NULL, gfp, 0);
1474 }
1475 
1476 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1477 {
1478 	return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1479 }
1480 
1481 /**
1482  * security_context_to_sid_default - Obtain a SID for a given security context,
1483  * falling back to specified default if needed.
1484  *
1485  * @scontext: security context
1486  * @scontext_len: length in bytes
1487  * @sid: security identifier, SID
1488  * @def_sid: default SID to assign on error
1489  *
1490  * Obtains a SID associated with the security context that
1491  * has the string representation specified by @scontext.
1492  * The default SID is passed to the MLS layer to be used to allow
1493  * kernel labeling of the MLS field if the MLS field is not present
1494  * (for upgrading to MLS without full relabel).
1495  * Implicitly forces adding of the context even if it cannot be mapped yet.
1496  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1497  * memory is available, or 0 on success.
1498  */
1499 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1500 				    u32 *sid, u32 def_sid, gfp_t gfp_flags)
1501 {
1502 	return security_context_to_sid_core(scontext, scontext_len,
1503 					    sid, def_sid, gfp_flags, 1);
1504 }
1505 
1506 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1507 				  u32 *sid)
1508 {
1509 	return security_context_to_sid_core(scontext, scontext_len,
1510 					    sid, SECSID_NULL, GFP_KERNEL, 1);
1511 }
1512 
1513 static int compute_sid_handle_invalid_context(
1514 	struct context *scontext,
1515 	struct context *tcontext,
1516 	u16 tclass,
1517 	struct context *newcontext)
1518 {
1519 	char *s = NULL, *t = NULL, *n = NULL;
1520 	u32 slen, tlen, nlen;
1521 
1522 	if (context_struct_to_string(scontext, &s, &slen))
1523 		goto out;
1524 	if (context_struct_to_string(tcontext, &t, &tlen))
1525 		goto out;
1526 	if (context_struct_to_string(newcontext, &n, &nlen))
1527 		goto out;
1528 	audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1529 		  "op=security_compute_sid invalid_context=%s"
1530 		  " scontext=%s"
1531 		  " tcontext=%s"
1532 		  " tclass=%s",
1533 		  n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1534 out:
1535 	kfree(s);
1536 	kfree(t);
1537 	kfree(n);
1538 	if (!selinux_enforcing)
1539 		return 0;
1540 	return -EACCES;
1541 }
1542 
1543 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1544 				  u32 stype, u32 ttype, u16 tclass,
1545 				  const char *objname)
1546 {
1547 	struct filename_trans ft;
1548 	struct filename_trans_datum *otype;
1549 
1550 	/*
1551 	 * Most filename trans rules are going to live in specific directories
1552 	 * like /dev or /var/run.  This bitmap will quickly skip rule searches
1553 	 * if the ttype does not contain any rules.
1554 	 */
1555 	if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1556 		return;
1557 
1558 	ft.stype = stype;
1559 	ft.ttype = ttype;
1560 	ft.tclass = tclass;
1561 	ft.name = objname;
1562 
1563 	otype = hashtab_search(p->filename_trans, &ft);
1564 	if (otype)
1565 		newcontext->type = otype->otype;
1566 }
1567 
1568 static int security_compute_sid(u32 ssid,
1569 				u32 tsid,
1570 				u16 orig_tclass,
1571 				u32 specified,
1572 				const char *objname,
1573 				u32 *out_sid,
1574 				bool kern)
1575 {
1576 	struct class_datum *cladatum = NULL;
1577 	struct context *scontext = NULL, *tcontext = NULL, newcontext;
1578 	struct role_trans *roletr = NULL;
1579 	struct avtab_key avkey;
1580 	struct avtab_datum *avdatum;
1581 	struct avtab_node *node;
1582 	u16 tclass;
1583 	int rc = 0;
1584 	bool sock;
1585 
1586 	if (!ss_initialized) {
1587 		switch (orig_tclass) {
1588 		case SECCLASS_PROCESS: /* kernel value */
1589 			*out_sid = ssid;
1590 			break;
1591 		default:
1592 			*out_sid = tsid;
1593 			break;
1594 		}
1595 		goto out;
1596 	}
1597 
1598 	context_init(&newcontext);
1599 
1600 	read_lock(&policy_rwlock);
1601 
1602 	if (kern) {
1603 		tclass = unmap_class(orig_tclass);
1604 		sock = security_is_socket_class(orig_tclass);
1605 	} else {
1606 		tclass = orig_tclass;
1607 		sock = security_is_socket_class(map_class(tclass));
1608 	}
1609 
1610 	scontext = sidtab_search(&sidtab, ssid);
1611 	if (!scontext) {
1612 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1613 		       __func__, ssid);
1614 		rc = -EINVAL;
1615 		goto out_unlock;
1616 	}
1617 	tcontext = sidtab_search(&sidtab, tsid);
1618 	if (!tcontext) {
1619 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1620 		       __func__, tsid);
1621 		rc = -EINVAL;
1622 		goto out_unlock;
1623 	}
1624 
1625 	if (tclass && tclass <= policydb.p_classes.nprim)
1626 		cladatum = policydb.class_val_to_struct[tclass - 1];
1627 
1628 	/* Set the user identity. */
1629 	switch (specified) {
1630 	case AVTAB_TRANSITION:
1631 	case AVTAB_CHANGE:
1632 		if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1633 			newcontext.user = tcontext->user;
1634 		} else {
1635 			/* notice this gets both DEFAULT_SOURCE and unset */
1636 			/* Use the process user identity. */
1637 			newcontext.user = scontext->user;
1638 		}
1639 		break;
1640 	case AVTAB_MEMBER:
1641 		/* Use the related object owner. */
1642 		newcontext.user = tcontext->user;
1643 		break;
1644 	}
1645 
1646 	/* Set the role to default values. */
1647 	if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1648 		newcontext.role = scontext->role;
1649 	} else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1650 		newcontext.role = tcontext->role;
1651 	} else {
1652 		if ((tclass == policydb.process_class) || (sock == true))
1653 			newcontext.role = scontext->role;
1654 		else
1655 			newcontext.role = OBJECT_R_VAL;
1656 	}
1657 
1658 	/* Set the type to default values. */
1659 	if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1660 		newcontext.type = scontext->type;
1661 	} else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1662 		newcontext.type = tcontext->type;
1663 	} else {
1664 		if ((tclass == policydb.process_class) || (sock == true)) {
1665 			/* Use the type of process. */
1666 			newcontext.type = scontext->type;
1667 		} else {
1668 			/* Use the type of the related object. */
1669 			newcontext.type = tcontext->type;
1670 		}
1671 	}
1672 
1673 	/* Look for a type transition/member/change rule. */
1674 	avkey.source_type = scontext->type;
1675 	avkey.target_type = tcontext->type;
1676 	avkey.target_class = tclass;
1677 	avkey.specified = specified;
1678 	avdatum = avtab_search(&policydb.te_avtab, &avkey);
1679 
1680 	/* If no permanent rule, also check for enabled conditional rules */
1681 	if (!avdatum) {
1682 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1683 		for (; node; node = avtab_search_node_next(node, specified)) {
1684 			if (node->key.specified & AVTAB_ENABLED) {
1685 				avdatum = &node->datum;
1686 				break;
1687 			}
1688 		}
1689 	}
1690 
1691 	if (avdatum) {
1692 		/* Use the type from the type transition/member/change rule. */
1693 		newcontext.type = avdatum->u.data;
1694 	}
1695 
1696 	/* if we have a objname this is a file trans check so check those rules */
1697 	if (objname)
1698 		filename_compute_type(&policydb, &newcontext, scontext->type,
1699 				      tcontext->type, tclass, objname);
1700 
1701 	/* Check for class-specific changes. */
1702 	if (specified & AVTAB_TRANSITION) {
1703 		/* Look for a role transition rule. */
1704 		for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1705 			if ((roletr->role == scontext->role) &&
1706 			    (roletr->type == tcontext->type) &&
1707 			    (roletr->tclass == tclass)) {
1708 				/* Use the role transition rule. */
1709 				newcontext.role = roletr->new_role;
1710 				break;
1711 			}
1712 		}
1713 	}
1714 
1715 	/* Set the MLS attributes.
1716 	   This is done last because it may allocate memory. */
1717 	rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1718 			     &newcontext, sock);
1719 	if (rc)
1720 		goto out_unlock;
1721 
1722 	/* Check the validity of the context. */
1723 	if (!policydb_context_isvalid(&policydb, &newcontext)) {
1724 		rc = compute_sid_handle_invalid_context(scontext,
1725 							tcontext,
1726 							tclass,
1727 							&newcontext);
1728 		if (rc)
1729 			goto out_unlock;
1730 	}
1731 	/* Obtain the sid for the context. */
1732 	rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1733 out_unlock:
1734 	read_unlock(&policy_rwlock);
1735 	context_destroy(&newcontext);
1736 out:
1737 	return rc;
1738 }
1739 
1740 /**
1741  * security_transition_sid - Compute the SID for a new subject/object.
1742  * @ssid: source security identifier
1743  * @tsid: target security identifier
1744  * @tclass: target security class
1745  * @out_sid: security identifier for new subject/object
1746  *
1747  * Compute a SID to use for labeling a new subject or object in the
1748  * class @tclass based on a SID pair (@ssid, @tsid).
1749  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1750  * if insufficient memory is available, or %0 if the new SID was
1751  * computed successfully.
1752  */
1753 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1754 			    const struct qstr *qstr, u32 *out_sid)
1755 {
1756 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1757 				    qstr ? qstr->name : NULL, out_sid, true);
1758 }
1759 
1760 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1761 				 const char *objname, u32 *out_sid)
1762 {
1763 	return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1764 				    objname, out_sid, false);
1765 }
1766 
1767 /**
1768  * security_member_sid - Compute the SID for member selection.
1769  * @ssid: source security identifier
1770  * @tsid: target security identifier
1771  * @tclass: target security class
1772  * @out_sid: security identifier for selected member
1773  *
1774  * Compute a SID to use when selecting a member of a polyinstantiated
1775  * object of class @tclass based on a SID pair (@ssid, @tsid).
1776  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1777  * if insufficient memory is available, or %0 if the SID was
1778  * computed successfully.
1779  */
1780 int security_member_sid(u32 ssid,
1781 			u32 tsid,
1782 			u16 tclass,
1783 			u32 *out_sid)
1784 {
1785 	return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1786 				    out_sid, false);
1787 }
1788 
1789 /**
1790  * security_change_sid - Compute the SID for object relabeling.
1791  * @ssid: source security identifier
1792  * @tsid: target security identifier
1793  * @tclass: target security class
1794  * @out_sid: security identifier for selected member
1795  *
1796  * Compute a SID to use for relabeling an object of class @tclass
1797  * based on a SID pair (@ssid, @tsid).
1798  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1799  * if insufficient memory is available, or %0 if the SID was
1800  * computed successfully.
1801  */
1802 int security_change_sid(u32 ssid,
1803 			u32 tsid,
1804 			u16 tclass,
1805 			u32 *out_sid)
1806 {
1807 	return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1808 				    out_sid, false);
1809 }
1810 
1811 /* Clone the SID into the new SID table. */
1812 static int clone_sid(u32 sid,
1813 		     struct context *context,
1814 		     void *arg)
1815 {
1816 	struct sidtab *s = arg;
1817 
1818 	if (sid > SECINITSID_NUM)
1819 		return sidtab_insert(s, sid, context);
1820 	else
1821 		return 0;
1822 }
1823 
1824 static inline int convert_context_handle_invalid_context(struct context *context)
1825 {
1826 	char *s;
1827 	u32 len;
1828 
1829 	if (selinux_enforcing)
1830 		return -EINVAL;
1831 
1832 	if (!context_struct_to_string(context, &s, &len)) {
1833 		printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1834 		kfree(s);
1835 	}
1836 	return 0;
1837 }
1838 
1839 struct convert_context_args {
1840 	struct policydb *oldp;
1841 	struct policydb *newp;
1842 };
1843 
1844 /*
1845  * Convert the values in the security context
1846  * structure `c' from the values specified
1847  * in the policy `p->oldp' to the values specified
1848  * in the policy `p->newp'.  Verify that the
1849  * context is valid under the new policy.
1850  */
1851 static int convert_context(u32 key,
1852 			   struct context *c,
1853 			   void *p)
1854 {
1855 	struct convert_context_args *args;
1856 	struct context oldc;
1857 	struct ocontext *oc;
1858 	struct mls_range *range;
1859 	struct role_datum *role;
1860 	struct type_datum *typdatum;
1861 	struct user_datum *usrdatum;
1862 	char *s;
1863 	u32 len;
1864 	int rc = 0;
1865 
1866 	if (key <= SECINITSID_NUM)
1867 		goto out;
1868 
1869 	args = p;
1870 
1871 	if (c->str) {
1872 		struct context ctx;
1873 
1874 		rc = -ENOMEM;
1875 		s = kstrdup(c->str, GFP_KERNEL);
1876 		if (!s)
1877 			goto out;
1878 
1879 		rc = string_to_context_struct(args->newp, NULL, s,
1880 					      c->len, &ctx, SECSID_NULL);
1881 		kfree(s);
1882 		if (!rc) {
1883 			printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1884 			       c->str);
1885 			/* Replace string with mapped representation. */
1886 			kfree(c->str);
1887 			memcpy(c, &ctx, sizeof(*c));
1888 			goto out;
1889 		} else if (rc == -EINVAL) {
1890 			/* Retain string representation for later mapping. */
1891 			rc = 0;
1892 			goto out;
1893 		} else {
1894 			/* Other error condition, e.g. ENOMEM. */
1895 			printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1896 			       c->str, -rc);
1897 			goto out;
1898 		}
1899 	}
1900 
1901 	rc = context_cpy(&oldc, c);
1902 	if (rc)
1903 		goto out;
1904 
1905 	/* Convert the user. */
1906 	rc = -EINVAL;
1907 	usrdatum = hashtab_search(args->newp->p_users.table,
1908 				  sym_name(args->oldp, SYM_USERS, c->user - 1));
1909 	if (!usrdatum)
1910 		goto bad;
1911 	c->user = usrdatum->value;
1912 
1913 	/* Convert the role. */
1914 	rc = -EINVAL;
1915 	role = hashtab_search(args->newp->p_roles.table,
1916 			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
1917 	if (!role)
1918 		goto bad;
1919 	c->role = role->value;
1920 
1921 	/* Convert the type. */
1922 	rc = -EINVAL;
1923 	typdatum = hashtab_search(args->newp->p_types.table,
1924 				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
1925 	if (!typdatum)
1926 		goto bad;
1927 	c->type = typdatum->value;
1928 
1929 	/* Convert the MLS fields if dealing with MLS policies */
1930 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1931 		rc = mls_convert_context(args->oldp, args->newp, c);
1932 		if (rc)
1933 			goto bad;
1934 	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1935 		/*
1936 		 * Switching between MLS and non-MLS policy:
1937 		 * free any storage used by the MLS fields in the
1938 		 * context for all existing entries in the sidtab.
1939 		 */
1940 		mls_context_destroy(c);
1941 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1942 		/*
1943 		 * Switching between non-MLS and MLS policy:
1944 		 * ensure that the MLS fields of the context for all
1945 		 * existing entries in the sidtab are filled in with a
1946 		 * suitable default value, likely taken from one of the
1947 		 * initial SIDs.
1948 		 */
1949 		oc = args->newp->ocontexts[OCON_ISID];
1950 		while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1951 			oc = oc->next;
1952 		rc = -EINVAL;
1953 		if (!oc) {
1954 			printk(KERN_ERR "SELinux:  unable to look up"
1955 				" the initial SIDs list\n");
1956 			goto bad;
1957 		}
1958 		range = &oc->context[0].range;
1959 		rc = mls_range_set(c, range);
1960 		if (rc)
1961 			goto bad;
1962 	}
1963 
1964 	/* Check the validity of the new context. */
1965 	if (!policydb_context_isvalid(args->newp, c)) {
1966 		rc = convert_context_handle_invalid_context(&oldc);
1967 		if (rc)
1968 			goto bad;
1969 	}
1970 
1971 	context_destroy(&oldc);
1972 
1973 	rc = 0;
1974 out:
1975 	return rc;
1976 bad:
1977 	/* Map old representation to string and save it. */
1978 	rc = context_struct_to_string(&oldc, &s, &len);
1979 	if (rc)
1980 		return rc;
1981 	context_destroy(&oldc);
1982 	context_destroy(c);
1983 	c->str = s;
1984 	c->len = len;
1985 	printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1986 	       c->str);
1987 	rc = 0;
1988 	goto out;
1989 }
1990 
1991 static void security_load_policycaps(void)
1992 {
1993 	selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1994 						  POLICYDB_CAPABILITY_NETPEER);
1995 	selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1996 						  POLICYDB_CAPABILITY_OPENPERM);
1997 	selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1998 						  POLICYDB_CAPABILITY_ALWAYSNETWORK);
1999 }
2000 
2001 static int security_preserve_bools(struct policydb *p);
2002 
2003 /**
2004  * security_load_policy - Load a security policy configuration.
2005  * @data: binary policy data
2006  * @len: length of data in bytes
2007  *
2008  * Load a new set of security policy configuration data,
2009  * validate it and convert the SID table as necessary.
2010  * This function will flush the access vector cache after
2011  * loading the new policy.
2012  */
2013 int security_load_policy(void *data, size_t len)
2014 {
2015 	struct policydb *oldpolicydb, *newpolicydb;
2016 	struct sidtab oldsidtab, newsidtab;
2017 	struct selinux_mapping *oldmap, *map = NULL;
2018 	struct convert_context_args args;
2019 	u32 seqno;
2020 	u16 map_size;
2021 	int rc = 0;
2022 	struct policy_file file = { data, len }, *fp = &file;
2023 
2024 	oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2025 	if (!oldpolicydb) {
2026 		rc = -ENOMEM;
2027 		goto out;
2028 	}
2029 	newpolicydb = oldpolicydb + 1;
2030 
2031 	if (!ss_initialized) {
2032 		avtab_cache_init();
2033 		rc = policydb_read(&policydb, fp);
2034 		if (rc) {
2035 			avtab_cache_destroy();
2036 			goto out;
2037 		}
2038 
2039 		policydb.len = len;
2040 		rc = selinux_set_mapping(&policydb, secclass_map,
2041 					 &current_mapping,
2042 					 &current_mapping_size);
2043 		if (rc) {
2044 			policydb_destroy(&policydb);
2045 			avtab_cache_destroy();
2046 			goto out;
2047 		}
2048 
2049 		rc = policydb_load_isids(&policydb, &sidtab);
2050 		if (rc) {
2051 			policydb_destroy(&policydb);
2052 			avtab_cache_destroy();
2053 			goto out;
2054 		}
2055 
2056 		security_load_policycaps();
2057 		ss_initialized = 1;
2058 		seqno = ++latest_granting;
2059 		selinux_complete_init();
2060 		avc_ss_reset(seqno);
2061 		selnl_notify_policyload(seqno);
2062 		selinux_status_update_policyload(seqno);
2063 		selinux_netlbl_cache_invalidate();
2064 		selinux_xfrm_notify_policyload();
2065 		goto out;
2066 	}
2067 
2068 #if 0
2069 	sidtab_hash_eval(&sidtab, "sids");
2070 #endif
2071 
2072 	rc = policydb_read(newpolicydb, fp);
2073 	if (rc)
2074 		goto out;
2075 
2076 	newpolicydb->len = len;
2077 	/* If switching between different policy types, log MLS status */
2078 	if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2079 		printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2080 	else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2081 		printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2082 
2083 	rc = policydb_load_isids(newpolicydb, &newsidtab);
2084 	if (rc) {
2085 		printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2086 		policydb_destroy(newpolicydb);
2087 		goto out;
2088 	}
2089 
2090 	rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2091 	if (rc)
2092 		goto err;
2093 
2094 	rc = security_preserve_bools(newpolicydb);
2095 	if (rc) {
2096 		printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2097 		goto err;
2098 	}
2099 
2100 	/* Clone the SID table. */
2101 	sidtab_shutdown(&sidtab);
2102 
2103 	rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2104 	if (rc)
2105 		goto err;
2106 
2107 	/*
2108 	 * Convert the internal representations of contexts
2109 	 * in the new SID table.
2110 	 */
2111 	args.oldp = &policydb;
2112 	args.newp = newpolicydb;
2113 	rc = sidtab_map(&newsidtab, convert_context, &args);
2114 	if (rc) {
2115 		printk(KERN_ERR "SELinux:  unable to convert the internal"
2116 			" representation of contexts in the new SID"
2117 			" table\n");
2118 		goto err;
2119 	}
2120 
2121 	/* Save the old policydb and SID table to free later. */
2122 	memcpy(oldpolicydb, &policydb, sizeof(policydb));
2123 	sidtab_set(&oldsidtab, &sidtab);
2124 
2125 	/* Install the new policydb and SID table. */
2126 	write_lock_irq(&policy_rwlock);
2127 	memcpy(&policydb, newpolicydb, sizeof(policydb));
2128 	sidtab_set(&sidtab, &newsidtab);
2129 	security_load_policycaps();
2130 	oldmap = current_mapping;
2131 	current_mapping = map;
2132 	current_mapping_size = map_size;
2133 	seqno = ++latest_granting;
2134 	write_unlock_irq(&policy_rwlock);
2135 
2136 	/* Free the old policydb and SID table. */
2137 	policydb_destroy(oldpolicydb);
2138 	sidtab_destroy(&oldsidtab);
2139 	kfree(oldmap);
2140 
2141 	avc_ss_reset(seqno);
2142 	selnl_notify_policyload(seqno);
2143 	selinux_status_update_policyload(seqno);
2144 	selinux_netlbl_cache_invalidate();
2145 	selinux_xfrm_notify_policyload();
2146 
2147 	rc = 0;
2148 	goto out;
2149 
2150 err:
2151 	kfree(map);
2152 	sidtab_destroy(&newsidtab);
2153 	policydb_destroy(newpolicydb);
2154 
2155 out:
2156 	kfree(oldpolicydb);
2157 	return rc;
2158 }
2159 
2160 size_t security_policydb_len(void)
2161 {
2162 	size_t len;
2163 
2164 	read_lock(&policy_rwlock);
2165 	len = policydb.len;
2166 	read_unlock(&policy_rwlock);
2167 
2168 	return len;
2169 }
2170 
2171 /**
2172  * security_port_sid - Obtain the SID for a port.
2173  * @protocol: protocol number
2174  * @port: port number
2175  * @out_sid: security identifier
2176  */
2177 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2178 {
2179 	struct ocontext *c;
2180 	int rc = 0;
2181 
2182 	read_lock(&policy_rwlock);
2183 
2184 	c = policydb.ocontexts[OCON_PORT];
2185 	while (c) {
2186 		if (c->u.port.protocol == protocol &&
2187 		    c->u.port.low_port <= port &&
2188 		    c->u.port.high_port >= port)
2189 			break;
2190 		c = c->next;
2191 	}
2192 
2193 	if (c) {
2194 		if (!c->sid[0]) {
2195 			rc = sidtab_context_to_sid(&sidtab,
2196 						   &c->context[0],
2197 						   &c->sid[0]);
2198 			if (rc)
2199 				goto out;
2200 		}
2201 		*out_sid = c->sid[0];
2202 	} else {
2203 		*out_sid = SECINITSID_PORT;
2204 	}
2205 
2206 out:
2207 	read_unlock(&policy_rwlock);
2208 	return rc;
2209 }
2210 
2211 /**
2212  * security_netif_sid - Obtain the SID for a network interface.
2213  * @name: interface name
2214  * @if_sid: interface SID
2215  */
2216 int security_netif_sid(char *name, u32 *if_sid)
2217 {
2218 	int rc = 0;
2219 	struct ocontext *c;
2220 
2221 	read_lock(&policy_rwlock);
2222 
2223 	c = policydb.ocontexts[OCON_NETIF];
2224 	while (c) {
2225 		if (strcmp(name, c->u.name) == 0)
2226 			break;
2227 		c = c->next;
2228 	}
2229 
2230 	if (c) {
2231 		if (!c->sid[0] || !c->sid[1]) {
2232 			rc = sidtab_context_to_sid(&sidtab,
2233 						  &c->context[0],
2234 						  &c->sid[0]);
2235 			if (rc)
2236 				goto out;
2237 			rc = sidtab_context_to_sid(&sidtab,
2238 						   &c->context[1],
2239 						   &c->sid[1]);
2240 			if (rc)
2241 				goto out;
2242 		}
2243 		*if_sid = c->sid[0];
2244 	} else
2245 		*if_sid = SECINITSID_NETIF;
2246 
2247 out:
2248 	read_unlock(&policy_rwlock);
2249 	return rc;
2250 }
2251 
2252 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2253 {
2254 	int i, fail = 0;
2255 
2256 	for (i = 0; i < 4; i++)
2257 		if (addr[i] != (input[i] & mask[i])) {
2258 			fail = 1;
2259 			break;
2260 		}
2261 
2262 	return !fail;
2263 }
2264 
2265 /**
2266  * security_node_sid - Obtain the SID for a node (host).
2267  * @domain: communication domain aka address family
2268  * @addrp: address
2269  * @addrlen: address length in bytes
2270  * @out_sid: security identifier
2271  */
2272 int security_node_sid(u16 domain,
2273 		      void *addrp,
2274 		      u32 addrlen,
2275 		      u32 *out_sid)
2276 {
2277 	int rc;
2278 	struct ocontext *c;
2279 
2280 	read_lock(&policy_rwlock);
2281 
2282 	switch (domain) {
2283 	case AF_INET: {
2284 		u32 addr;
2285 
2286 		rc = -EINVAL;
2287 		if (addrlen != sizeof(u32))
2288 			goto out;
2289 
2290 		addr = *((u32 *)addrp);
2291 
2292 		c = policydb.ocontexts[OCON_NODE];
2293 		while (c) {
2294 			if (c->u.node.addr == (addr & c->u.node.mask))
2295 				break;
2296 			c = c->next;
2297 		}
2298 		break;
2299 	}
2300 
2301 	case AF_INET6:
2302 		rc = -EINVAL;
2303 		if (addrlen != sizeof(u64) * 2)
2304 			goto out;
2305 		c = policydb.ocontexts[OCON_NODE6];
2306 		while (c) {
2307 			if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2308 						c->u.node6.mask))
2309 				break;
2310 			c = c->next;
2311 		}
2312 		break;
2313 
2314 	default:
2315 		rc = 0;
2316 		*out_sid = SECINITSID_NODE;
2317 		goto out;
2318 	}
2319 
2320 	if (c) {
2321 		if (!c->sid[0]) {
2322 			rc = sidtab_context_to_sid(&sidtab,
2323 						   &c->context[0],
2324 						   &c->sid[0]);
2325 			if (rc)
2326 				goto out;
2327 		}
2328 		*out_sid = c->sid[0];
2329 	} else {
2330 		*out_sid = SECINITSID_NODE;
2331 	}
2332 
2333 	rc = 0;
2334 out:
2335 	read_unlock(&policy_rwlock);
2336 	return rc;
2337 }
2338 
2339 #define SIDS_NEL 25
2340 
2341 /**
2342  * security_get_user_sids - Obtain reachable SIDs for a user.
2343  * @fromsid: starting SID
2344  * @username: username
2345  * @sids: array of reachable SIDs for user
2346  * @nel: number of elements in @sids
2347  *
2348  * Generate the set of SIDs for legal security contexts
2349  * for a given user that can be reached by @fromsid.
2350  * Set *@sids to point to a dynamically allocated
2351  * array containing the set of SIDs.  Set *@nel to the
2352  * number of elements in the array.
2353  */
2354 
2355 int security_get_user_sids(u32 fromsid,
2356 			   char *username,
2357 			   u32 **sids,
2358 			   u32 *nel)
2359 {
2360 	struct context *fromcon, usercon;
2361 	u32 *mysids = NULL, *mysids2, sid;
2362 	u32 mynel = 0, maxnel = SIDS_NEL;
2363 	struct user_datum *user;
2364 	struct role_datum *role;
2365 	struct ebitmap_node *rnode, *tnode;
2366 	int rc = 0, i, j;
2367 
2368 	*sids = NULL;
2369 	*nel = 0;
2370 
2371 	if (!ss_initialized)
2372 		goto out;
2373 
2374 	read_lock(&policy_rwlock);
2375 
2376 	context_init(&usercon);
2377 
2378 	rc = -EINVAL;
2379 	fromcon = sidtab_search(&sidtab, fromsid);
2380 	if (!fromcon)
2381 		goto out_unlock;
2382 
2383 	rc = -EINVAL;
2384 	user = hashtab_search(policydb.p_users.table, username);
2385 	if (!user)
2386 		goto out_unlock;
2387 
2388 	usercon.user = user->value;
2389 
2390 	rc = -ENOMEM;
2391 	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2392 	if (!mysids)
2393 		goto out_unlock;
2394 
2395 	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2396 		role = policydb.role_val_to_struct[i];
2397 		usercon.role = i + 1;
2398 		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2399 			usercon.type = j + 1;
2400 
2401 			if (mls_setup_user_range(fromcon, user, &usercon))
2402 				continue;
2403 
2404 			rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2405 			if (rc)
2406 				goto out_unlock;
2407 			if (mynel < maxnel) {
2408 				mysids[mynel++] = sid;
2409 			} else {
2410 				rc = -ENOMEM;
2411 				maxnel += SIDS_NEL;
2412 				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2413 				if (!mysids2)
2414 					goto out_unlock;
2415 				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2416 				kfree(mysids);
2417 				mysids = mysids2;
2418 				mysids[mynel++] = sid;
2419 			}
2420 		}
2421 	}
2422 	rc = 0;
2423 out_unlock:
2424 	read_unlock(&policy_rwlock);
2425 	if (rc || !mynel) {
2426 		kfree(mysids);
2427 		goto out;
2428 	}
2429 
2430 	rc = -ENOMEM;
2431 	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2432 	if (!mysids2) {
2433 		kfree(mysids);
2434 		goto out;
2435 	}
2436 	for (i = 0, j = 0; i < mynel; i++) {
2437 		struct av_decision dummy_avd;
2438 		rc = avc_has_perm_noaudit(fromsid, mysids[i],
2439 					  SECCLASS_PROCESS, /* kernel value */
2440 					  PROCESS__TRANSITION, AVC_STRICT,
2441 					  &dummy_avd);
2442 		if (!rc)
2443 			mysids2[j++] = mysids[i];
2444 		cond_resched();
2445 	}
2446 	rc = 0;
2447 	kfree(mysids);
2448 	*sids = mysids2;
2449 	*nel = j;
2450 out:
2451 	return rc;
2452 }
2453 
2454 /**
2455  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2456  * @fstype: filesystem type
2457  * @path: path from root of mount
2458  * @sclass: file security class
2459  * @sid: SID for path
2460  *
2461  * Obtain a SID to use for a file in a filesystem that
2462  * cannot support xattr or use a fixed labeling behavior like
2463  * transition SIDs or task SIDs.
2464  *
2465  * The caller must acquire the policy_rwlock before calling this function.
2466  */
2467 static inline int __security_genfs_sid(const char *fstype,
2468 				       char *path,
2469 				       u16 orig_sclass,
2470 				       u32 *sid)
2471 {
2472 	int len;
2473 	u16 sclass;
2474 	struct genfs *genfs;
2475 	struct ocontext *c;
2476 	int rc, cmp = 0;
2477 
2478 	while (path[0] == '/' && path[1] == '/')
2479 		path++;
2480 
2481 	sclass = unmap_class(orig_sclass);
2482 	*sid = SECINITSID_UNLABELED;
2483 
2484 	for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2485 		cmp = strcmp(fstype, genfs->fstype);
2486 		if (cmp <= 0)
2487 			break;
2488 	}
2489 
2490 	rc = -ENOENT;
2491 	if (!genfs || cmp)
2492 		goto out;
2493 
2494 	for (c = genfs->head; c; c = c->next) {
2495 		len = strlen(c->u.name);
2496 		if ((!c->v.sclass || sclass == c->v.sclass) &&
2497 		    (strncmp(c->u.name, path, len) == 0))
2498 			break;
2499 	}
2500 
2501 	rc = -ENOENT;
2502 	if (!c)
2503 		goto out;
2504 
2505 	if (!c->sid[0]) {
2506 		rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2507 		if (rc)
2508 			goto out;
2509 	}
2510 
2511 	*sid = c->sid[0];
2512 	rc = 0;
2513 out:
2514 	return rc;
2515 }
2516 
2517 /**
2518  * security_genfs_sid - Obtain a SID for a file in a filesystem
2519  * @fstype: filesystem type
2520  * @path: path from root of mount
2521  * @sclass: file security class
2522  * @sid: SID for path
2523  *
2524  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2525  * it afterward.
2526  */
2527 int security_genfs_sid(const char *fstype,
2528 		       char *path,
2529 		       u16 orig_sclass,
2530 		       u32 *sid)
2531 {
2532 	int retval;
2533 
2534 	read_lock(&policy_rwlock);
2535 	retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2536 	read_unlock(&policy_rwlock);
2537 	return retval;
2538 }
2539 
2540 /**
2541  * security_fs_use - Determine how to handle labeling for a filesystem.
2542  * @sb: superblock in question
2543  */
2544 int security_fs_use(struct super_block *sb)
2545 {
2546 	int rc = 0;
2547 	struct ocontext *c;
2548 	struct superblock_security_struct *sbsec = sb->s_security;
2549 	const char *fstype = sb->s_type->name;
2550 
2551 	read_lock(&policy_rwlock);
2552 
2553 	c = policydb.ocontexts[OCON_FSUSE];
2554 	while (c) {
2555 		if (strcmp(fstype, c->u.name) == 0)
2556 			break;
2557 		c = c->next;
2558 	}
2559 
2560 	if (c) {
2561 		sbsec->behavior = c->v.behavior;
2562 		if (!c->sid[0]) {
2563 			rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2564 						   &c->sid[0]);
2565 			if (rc)
2566 				goto out;
2567 		}
2568 		sbsec->sid = c->sid[0];
2569 	} else {
2570 		rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2571 					  &sbsec->sid);
2572 		if (rc) {
2573 			sbsec->behavior = SECURITY_FS_USE_NONE;
2574 			rc = 0;
2575 		} else {
2576 			sbsec->behavior = SECURITY_FS_USE_GENFS;
2577 		}
2578 	}
2579 
2580 out:
2581 	read_unlock(&policy_rwlock);
2582 	return rc;
2583 }
2584 
2585 int security_get_bools(int *len, char ***names, int **values)
2586 {
2587 	int i, rc;
2588 
2589 	read_lock(&policy_rwlock);
2590 	*names = NULL;
2591 	*values = NULL;
2592 
2593 	rc = 0;
2594 	*len = policydb.p_bools.nprim;
2595 	if (!*len)
2596 		goto out;
2597 
2598 	rc = -ENOMEM;
2599 	*names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2600 	if (!*names)
2601 		goto err;
2602 
2603 	rc = -ENOMEM;
2604 	*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2605 	if (!*values)
2606 		goto err;
2607 
2608 	for (i = 0; i < *len; i++) {
2609 		(*values)[i] = policydb.bool_val_to_struct[i]->state;
2610 
2611 		rc = -ENOMEM;
2612 		(*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2613 		if (!(*names)[i])
2614 			goto err;
2615 	}
2616 	rc = 0;
2617 out:
2618 	read_unlock(&policy_rwlock);
2619 	return rc;
2620 err:
2621 	if (*names) {
2622 		for (i = 0; i < *len; i++)
2623 			kfree((*names)[i]);
2624 	}
2625 	kfree(*values);
2626 	goto out;
2627 }
2628 
2629 
2630 int security_set_bools(int len, int *values)
2631 {
2632 	int i, rc;
2633 	int lenp, seqno = 0;
2634 	struct cond_node *cur;
2635 
2636 	write_lock_irq(&policy_rwlock);
2637 
2638 	rc = -EFAULT;
2639 	lenp = policydb.p_bools.nprim;
2640 	if (len != lenp)
2641 		goto out;
2642 
2643 	for (i = 0; i < len; i++) {
2644 		if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2645 			audit_log(current->audit_context, GFP_ATOMIC,
2646 				AUDIT_MAC_CONFIG_CHANGE,
2647 				"bool=%s val=%d old_val=%d auid=%u ses=%u",
2648 				sym_name(&policydb, SYM_BOOLS, i),
2649 				!!values[i],
2650 				policydb.bool_val_to_struct[i]->state,
2651 				from_kuid(&init_user_ns, audit_get_loginuid(current)),
2652 				audit_get_sessionid(current));
2653 		}
2654 		if (values[i])
2655 			policydb.bool_val_to_struct[i]->state = 1;
2656 		else
2657 			policydb.bool_val_to_struct[i]->state = 0;
2658 	}
2659 
2660 	for (cur = policydb.cond_list; cur; cur = cur->next) {
2661 		rc = evaluate_cond_node(&policydb, cur);
2662 		if (rc)
2663 			goto out;
2664 	}
2665 
2666 	seqno = ++latest_granting;
2667 	rc = 0;
2668 out:
2669 	write_unlock_irq(&policy_rwlock);
2670 	if (!rc) {
2671 		avc_ss_reset(seqno);
2672 		selnl_notify_policyload(seqno);
2673 		selinux_status_update_policyload(seqno);
2674 		selinux_xfrm_notify_policyload();
2675 	}
2676 	return rc;
2677 }
2678 
2679 int security_get_bool_value(int bool)
2680 {
2681 	int rc;
2682 	int len;
2683 
2684 	read_lock(&policy_rwlock);
2685 
2686 	rc = -EFAULT;
2687 	len = policydb.p_bools.nprim;
2688 	if (bool >= len)
2689 		goto out;
2690 
2691 	rc = policydb.bool_val_to_struct[bool]->state;
2692 out:
2693 	read_unlock(&policy_rwlock);
2694 	return rc;
2695 }
2696 
2697 static int security_preserve_bools(struct policydb *p)
2698 {
2699 	int rc, nbools = 0, *bvalues = NULL, i;
2700 	char **bnames = NULL;
2701 	struct cond_bool_datum *booldatum;
2702 	struct cond_node *cur;
2703 
2704 	rc = security_get_bools(&nbools, &bnames, &bvalues);
2705 	if (rc)
2706 		goto out;
2707 	for (i = 0; i < nbools; i++) {
2708 		booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2709 		if (booldatum)
2710 			booldatum->state = bvalues[i];
2711 	}
2712 	for (cur = p->cond_list; cur; cur = cur->next) {
2713 		rc = evaluate_cond_node(p, cur);
2714 		if (rc)
2715 			goto out;
2716 	}
2717 
2718 out:
2719 	if (bnames) {
2720 		for (i = 0; i < nbools; i++)
2721 			kfree(bnames[i]);
2722 	}
2723 	kfree(bnames);
2724 	kfree(bvalues);
2725 	return rc;
2726 }
2727 
2728 /*
2729  * security_sid_mls_copy() - computes a new sid based on the given
2730  * sid and the mls portion of mls_sid.
2731  */
2732 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2733 {
2734 	struct context *context1;
2735 	struct context *context2;
2736 	struct context newcon;
2737 	char *s;
2738 	u32 len;
2739 	int rc;
2740 
2741 	rc = 0;
2742 	if (!ss_initialized || !policydb.mls_enabled) {
2743 		*new_sid = sid;
2744 		goto out;
2745 	}
2746 
2747 	context_init(&newcon);
2748 
2749 	read_lock(&policy_rwlock);
2750 
2751 	rc = -EINVAL;
2752 	context1 = sidtab_search(&sidtab, sid);
2753 	if (!context1) {
2754 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2755 			__func__, sid);
2756 		goto out_unlock;
2757 	}
2758 
2759 	rc = -EINVAL;
2760 	context2 = sidtab_search(&sidtab, mls_sid);
2761 	if (!context2) {
2762 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2763 			__func__, mls_sid);
2764 		goto out_unlock;
2765 	}
2766 
2767 	newcon.user = context1->user;
2768 	newcon.role = context1->role;
2769 	newcon.type = context1->type;
2770 	rc = mls_context_cpy(&newcon, context2);
2771 	if (rc)
2772 		goto out_unlock;
2773 
2774 	/* Check the validity of the new context. */
2775 	if (!policydb_context_isvalid(&policydb, &newcon)) {
2776 		rc = convert_context_handle_invalid_context(&newcon);
2777 		if (rc) {
2778 			if (!context_struct_to_string(&newcon, &s, &len)) {
2779 				audit_log(current->audit_context,
2780 					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
2781 					  "op=security_sid_mls_copy "
2782 					  "invalid_context=%s", s);
2783 				kfree(s);
2784 			}
2785 			goto out_unlock;
2786 		}
2787 	}
2788 
2789 	rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2790 out_unlock:
2791 	read_unlock(&policy_rwlock);
2792 	context_destroy(&newcon);
2793 out:
2794 	return rc;
2795 }
2796 
2797 /**
2798  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2799  * @nlbl_sid: NetLabel SID
2800  * @nlbl_type: NetLabel labeling protocol type
2801  * @xfrm_sid: XFRM SID
2802  *
2803  * Description:
2804  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2805  * resolved into a single SID it is returned via @peer_sid and the function
2806  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2807  * returns a negative value.  A table summarizing the behavior is below:
2808  *
2809  *                                 | function return |      @sid
2810  *   ------------------------------+-----------------+-----------------
2811  *   no peer labels                |        0        |    SECSID_NULL
2812  *   single peer label             |        0        |    <peer_label>
2813  *   multiple, consistent labels   |        0        |    <peer_label>
2814  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2815  *
2816  */
2817 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2818 				 u32 xfrm_sid,
2819 				 u32 *peer_sid)
2820 {
2821 	int rc;
2822 	struct context *nlbl_ctx;
2823 	struct context *xfrm_ctx;
2824 
2825 	*peer_sid = SECSID_NULL;
2826 
2827 	/* handle the common (which also happens to be the set of easy) cases
2828 	 * right away, these two if statements catch everything involving a
2829 	 * single or absent peer SID/label */
2830 	if (xfrm_sid == SECSID_NULL) {
2831 		*peer_sid = nlbl_sid;
2832 		return 0;
2833 	}
2834 	/* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2835 	 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2836 	 * is present */
2837 	if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2838 		*peer_sid = xfrm_sid;
2839 		return 0;
2840 	}
2841 
2842 	/* we don't need to check ss_initialized here since the only way both
2843 	 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2844 	 * security server was initialized and ss_initialized was true */
2845 	if (!policydb.mls_enabled)
2846 		return 0;
2847 
2848 	read_lock(&policy_rwlock);
2849 
2850 	rc = -EINVAL;
2851 	nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2852 	if (!nlbl_ctx) {
2853 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2854 		       __func__, nlbl_sid);
2855 		goto out;
2856 	}
2857 	rc = -EINVAL;
2858 	xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2859 	if (!xfrm_ctx) {
2860 		printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2861 		       __func__, xfrm_sid);
2862 		goto out;
2863 	}
2864 	rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2865 	if (rc)
2866 		goto out;
2867 
2868 	/* at present NetLabel SIDs/labels really only carry MLS
2869 	 * information so if the MLS portion of the NetLabel SID
2870 	 * matches the MLS portion of the labeled XFRM SID/label
2871 	 * then pass along the XFRM SID as it is the most
2872 	 * expressive */
2873 	*peer_sid = xfrm_sid;
2874 out:
2875 	read_unlock(&policy_rwlock);
2876 	return rc;
2877 }
2878 
2879 static int get_classes_callback(void *k, void *d, void *args)
2880 {
2881 	struct class_datum *datum = d;
2882 	char *name = k, **classes = args;
2883 	int value = datum->value - 1;
2884 
2885 	classes[value] = kstrdup(name, GFP_ATOMIC);
2886 	if (!classes[value])
2887 		return -ENOMEM;
2888 
2889 	return 0;
2890 }
2891 
2892 int security_get_classes(char ***classes, int *nclasses)
2893 {
2894 	int rc;
2895 
2896 	read_lock(&policy_rwlock);
2897 
2898 	rc = -ENOMEM;
2899 	*nclasses = policydb.p_classes.nprim;
2900 	*classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2901 	if (!*classes)
2902 		goto out;
2903 
2904 	rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2905 			*classes);
2906 	if (rc) {
2907 		int i;
2908 		for (i = 0; i < *nclasses; i++)
2909 			kfree((*classes)[i]);
2910 		kfree(*classes);
2911 	}
2912 
2913 out:
2914 	read_unlock(&policy_rwlock);
2915 	return rc;
2916 }
2917 
2918 static int get_permissions_callback(void *k, void *d, void *args)
2919 {
2920 	struct perm_datum *datum = d;
2921 	char *name = k, **perms = args;
2922 	int value = datum->value - 1;
2923 
2924 	perms[value] = kstrdup(name, GFP_ATOMIC);
2925 	if (!perms[value])
2926 		return -ENOMEM;
2927 
2928 	return 0;
2929 }
2930 
2931 int security_get_permissions(char *class, char ***perms, int *nperms)
2932 {
2933 	int rc, i;
2934 	struct class_datum *match;
2935 
2936 	read_lock(&policy_rwlock);
2937 
2938 	rc = -EINVAL;
2939 	match = hashtab_search(policydb.p_classes.table, class);
2940 	if (!match) {
2941 		printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2942 			__func__, class);
2943 		goto out;
2944 	}
2945 
2946 	rc = -ENOMEM;
2947 	*nperms = match->permissions.nprim;
2948 	*perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2949 	if (!*perms)
2950 		goto out;
2951 
2952 	if (match->comdatum) {
2953 		rc = hashtab_map(match->comdatum->permissions.table,
2954 				get_permissions_callback, *perms);
2955 		if (rc)
2956 			goto err;
2957 	}
2958 
2959 	rc = hashtab_map(match->permissions.table, get_permissions_callback,
2960 			*perms);
2961 	if (rc)
2962 		goto err;
2963 
2964 out:
2965 	read_unlock(&policy_rwlock);
2966 	return rc;
2967 
2968 err:
2969 	read_unlock(&policy_rwlock);
2970 	for (i = 0; i < *nperms; i++)
2971 		kfree((*perms)[i]);
2972 	kfree(*perms);
2973 	return rc;
2974 }
2975 
2976 int security_get_reject_unknown(void)
2977 {
2978 	return policydb.reject_unknown;
2979 }
2980 
2981 int security_get_allow_unknown(void)
2982 {
2983 	return policydb.allow_unknown;
2984 }
2985 
2986 /**
2987  * security_policycap_supported - Check for a specific policy capability
2988  * @req_cap: capability
2989  *
2990  * Description:
2991  * This function queries the currently loaded policy to see if it supports the
2992  * capability specified by @req_cap.  Returns true (1) if the capability is
2993  * supported, false (0) if it isn't supported.
2994  *
2995  */
2996 int security_policycap_supported(unsigned int req_cap)
2997 {
2998 	int rc;
2999 
3000 	read_lock(&policy_rwlock);
3001 	rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3002 	read_unlock(&policy_rwlock);
3003 
3004 	return rc;
3005 }
3006 
3007 struct selinux_audit_rule {
3008 	u32 au_seqno;
3009 	struct context au_ctxt;
3010 };
3011 
3012 void selinux_audit_rule_free(void *vrule)
3013 {
3014 	struct selinux_audit_rule *rule = vrule;
3015 
3016 	if (rule) {
3017 		context_destroy(&rule->au_ctxt);
3018 		kfree(rule);
3019 	}
3020 }
3021 
3022 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3023 {
3024 	struct selinux_audit_rule *tmprule;
3025 	struct role_datum *roledatum;
3026 	struct type_datum *typedatum;
3027 	struct user_datum *userdatum;
3028 	struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3029 	int rc = 0;
3030 
3031 	*rule = NULL;
3032 
3033 	if (!ss_initialized)
3034 		return -EOPNOTSUPP;
3035 
3036 	switch (field) {
3037 	case AUDIT_SUBJ_USER:
3038 	case AUDIT_SUBJ_ROLE:
3039 	case AUDIT_SUBJ_TYPE:
3040 	case AUDIT_OBJ_USER:
3041 	case AUDIT_OBJ_ROLE:
3042 	case AUDIT_OBJ_TYPE:
3043 		/* only 'equals' and 'not equals' fit user, role, and type */
3044 		if (op != Audit_equal && op != Audit_not_equal)
3045 			return -EINVAL;
3046 		break;
3047 	case AUDIT_SUBJ_SEN:
3048 	case AUDIT_SUBJ_CLR:
3049 	case AUDIT_OBJ_LEV_LOW:
3050 	case AUDIT_OBJ_LEV_HIGH:
3051 		/* we do not allow a range, indicated by the presence of '-' */
3052 		if (strchr(rulestr, '-'))
3053 			return -EINVAL;
3054 		break;
3055 	default:
3056 		/* only the above fields are valid */
3057 		return -EINVAL;
3058 	}
3059 
3060 	tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3061 	if (!tmprule)
3062 		return -ENOMEM;
3063 
3064 	context_init(&tmprule->au_ctxt);
3065 
3066 	read_lock(&policy_rwlock);
3067 
3068 	tmprule->au_seqno = latest_granting;
3069 
3070 	switch (field) {
3071 	case AUDIT_SUBJ_USER:
3072 	case AUDIT_OBJ_USER:
3073 		rc = -EINVAL;
3074 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
3075 		if (!userdatum)
3076 			goto out;
3077 		tmprule->au_ctxt.user = userdatum->value;
3078 		break;
3079 	case AUDIT_SUBJ_ROLE:
3080 	case AUDIT_OBJ_ROLE:
3081 		rc = -EINVAL;
3082 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3083 		if (!roledatum)
3084 			goto out;
3085 		tmprule->au_ctxt.role = roledatum->value;
3086 		break;
3087 	case AUDIT_SUBJ_TYPE:
3088 	case AUDIT_OBJ_TYPE:
3089 		rc = -EINVAL;
3090 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
3091 		if (!typedatum)
3092 			goto out;
3093 		tmprule->au_ctxt.type = typedatum->value;
3094 		break;
3095 	case AUDIT_SUBJ_SEN:
3096 	case AUDIT_SUBJ_CLR:
3097 	case AUDIT_OBJ_LEV_LOW:
3098 	case AUDIT_OBJ_LEV_HIGH:
3099 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3100 		if (rc)
3101 			goto out;
3102 		break;
3103 	}
3104 	rc = 0;
3105 out:
3106 	read_unlock(&policy_rwlock);
3107 
3108 	if (rc) {
3109 		selinux_audit_rule_free(tmprule);
3110 		tmprule = NULL;
3111 	}
3112 
3113 	*rule = tmprule;
3114 
3115 	return rc;
3116 }
3117 
3118 /* Check to see if the rule contains any selinux fields */
3119 int selinux_audit_rule_known(struct audit_krule *rule)
3120 {
3121 	int i;
3122 
3123 	for (i = 0; i < rule->field_count; i++) {
3124 		struct audit_field *f = &rule->fields[i];
3125 		switch (f->type) {
3126 		case AUDIT_SUBJ_USER:
3127 		case AUDIT_SUBJ_ROLE:
3128 		case AUDIT_SUBJ_TYPE:
3129 		case AUDIT_SUBJ_SEN:
3130 		case AUDIT_SUBJ_CLR:
3131 		case AUDIT_OBJ_USER:
3132 		case AUDIT_OBJ_ROLE:
3133 		case AUDIT_OBJ_TYPE:
3134 		case AUDIT_OBJ_LEV_LOW:
3135 		case AUDIT_OBJ_LEV_HIGH:
3136 			return 1;
3137 		}
3138 	}
3139 
3140 	return 0;
3141 }
3142 
3143 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3144 			     struct audit_context *actx)
3145 {
3146 	struct context *ctxt;
3147 	struct mls_level *level;
3148 	struct selinux_audit_rule *rule = vrule;
3149 	int match = 0;
3150 
3151 	if (unlikely(!rule)) {
3152 		WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3153 		return -ENOENT;
3154 	}
3155 
3156 	read_lock(&policy_rwlock);
3157 
3158 	if (rule->au_seqno < latest_granting) {
3159 		match = -ESTALE;
3160 		goto out;
3161 	}
3162 
3163 	ctxt = sidtab_search(&sidtab, sid);
3164 	if (unlikely(!ctxt)) {
3165 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3166 			  sid);
3167 		match = -ENOENT;
3168 		goto out;
3169 	}
3170 
3171 	/* a field/op pair that is not caught here will simply fall through
3172 	   without a match */
3173 	switch (field) {
3174 	case AUDIT_SUBJ_USER:
3175 	case AUDIT_OBJ_USER:
3176 		switch (op) {
3177 		case Audit_equal:
3178 			match = (ctxt->user == rule->au_ctxt.user);
3179 			break;
3180 		case Audit_not_equal:
3181 			match = (ctxt->user != rule->au_ctxt.user);
3182 			break;
3183 		}
3184 		break;
3185 	case AUDIT_SUBJ_ROLE:
3186 	case AUDIT_OBJ_ROLE:
3187 		switch (op) {
3188 		case Audit_equal:
3189 			match = (ctxt->role == rule->au_ctxt.role);
3190 			break;
3191 		case Audit_not_equal:
3192 			match = (ctxt->role != rule->au_ctxt.role);
3193 			break;
3194 		}
3195 		break;
3196 	case AUDIT_SUBJ_TYPE:
3197 	case AUDIT_OBJ_TYPE:
3198 		switch (op) {
3199 		case Audit_equal:
3200 			match = (ctxt->type == rule->au_ctxt.type);
3201 			break;
3202 		case Audit_not_equal:
3203 			match = (ctxt->type != rule->au_ctxt.type);
3204 			break;
3205 		}
3206 		break;
3207 	case AUDIT_SUBJ_SEN:
3208 	case AUDIT_SUBJ_CLR:
3209 	case AUDIT_OBJ_LEV_LOW:
3210 	case AUDIT_OBJ_LEV_HIGH:
3211 		level = ((field == AUDIT_SUBJ_SEN ||
3212 			  field == AUDIT_OBJ_LEV_LOW) ?
3213 			 &ctxt->range.level[0] : &ctxt->range.level[1]);
3214 		switch (op) {
3215 		case Audit_equal:
3216 			match = mls_level_eq(&rule->au_ctxt.range.level[0],
3217 					     level);
3218 			break;
3219 		case Audit_not_equal:
3220 			match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3221 					      level);
3222 			break;
3223 		case Audit_lt:
3224 			match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3225 					       level) &&
3226 				 !mls_level_eq(&rule->au_ctxt.range.level[0],
3227 					       level));
3228 			break;
3229 		case Audit_le:
3230 			match = mls_level_dom(&rule->au_ctxt.range.level[0],
3231 					      level);
3232 			break;
3233 		case Audit_gt:
3234 			match = (mls_level_dom(level,
3235 					      &rule->au_ctxt.range.level[0]) &&
3236 				 !mls_level_eq(level,
3237 					       &rule->au_ctxt.range.level[0]));
3238 			break;
3239 		case Audit_ge:
3240 			match = mls_level_dom(level,
3241 					      &rule->au_ctxt.range.level[0]);
3242 			break;
3243 		}
3244 	}
3245 
3246 out:
3247 	read_unlock(&policy_rwlock);
3248 	return match;
3249 }
3250 
3251 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3252 
3253 static int aurule_avc_callback(u32 event)
3254 {
3255 	int err = 0;
3256 
3257 	if (event == AVC_CALLBACK_RESET && aurule_callback)
3258 		err = aurule_callback();
3259 	return err;
3260 }
3261 
3262 static int __init aurule_init(void)
3263 {
3264 	int err;
3265 
3266 	err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3267 	if (err)
3268 		panic("avc_add_callback() failed, error %d\n", err);
3269 
3270 	return err;
3271 }
3272 __initcall(aurule_init);
3273 
3274 #ifdef CONFIG_NETLABEL
3275 /**
3276  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3277  * @secattr: the NetLabel packet security attributes
3278  * @sid: the SELinux SID
3279  *
3280  * Description:
3281  * Attempt to cache the context in @ctx, which was derived from the packet in
3282  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3283  * already been initialized.
3284  *
3285  */
3286 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3287 				      u32 sid)
3288 {
3289 	u32 *sid_cache;
3290 
3291 	sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3292 	if (sid_cache == NULL)
3293 		return;
3294 	secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3295 	if (secattr->cache == NULL) {
3296 		kfree(sid_cache);
3297 		return;
3298 	}
3299 
3300 	*sid_cache = sid;
3301 	secattr->cache->free = kfree;
3302 	secattr->cache->data = sid_cache;
3303 	secattr->flags |= NETLBL_SECATTR_CACHE;
3304 }
3305 
3306 /**
3307  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3308  * @secattr: the NetLabel packet security attributes
3309  * @sid: the SELinux SID
3310  *
3311  * Description:
3312  * Convert the given NetLabel security attributes in @secattr into a
3313  * SELinux SID.  If the @secattr field does not contain a full SELinux
3314  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3315  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3316  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3317  * conversion for future lookups.  Returns zero on success, negative values on
3318  * failure.
3319  *
3320  */
3321 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3322 				   u32 *sid)
3323 {
3324 	int rc;
3325 	struct context *ctx;
3326 	struct context ctx_new;
3327 
3328 	if (!ss_initialized) {
3329 		*sid = SECSID_NULL;
3330 		return 0;
3331 	}
3332 
3333 	read_lock(&policy_rwlock);
3334 
3335 	if (secattr->flags & NETLBL_SECATTR_CACHE)
3336 		*sid = *(u32 *)secattr->cache->data;
3337 	else if (secattr->flags & NETLBL_SECATTR_SECID)
3338 		*sid = secattr->attr.secid;
3339 	else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3340 		rc = -EIDRM;
3341 		ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3342 		if (ctx == NULL)
3343 			goto out;
3344 
3345 		context_init(&ctx_new);
3346 		ctx_new.user = ctx->user;
3347 		ctx_new.role = ctx->role;
3348 		ctx_new.type = ctx->type;
3349 		mls_import_netlbl_lvl(&ctx_new, secattr);
3350 		if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3351 			rc = mls_import_netlbl_cat(&ctx_new, secattr);
3352 			if (rc)
3353 				goto out;
3354 		}
3355 		rc = -EIDRM;
3356 		if (!mls_context_isvalid(&policydb, &ctx_new))
3357 			goto out_free;
3358 
3359 		rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3360 		if (rc)
3361 			goto out_free;
3362 
3363 		security_netlbl_cache_add(secattr, *sid);
3364 
3365 		ebitmap_destroy(&ctx_new.range.level[0].cat);
3366 	} else
3367 		*sid = SECSID_NULL;
3368 
3369 	read_unlock(&policy_rwlock);
3370 	return 0;
3371 out_free:
3372 	ebitmap_destroy(&ctx_new.range.level[0].cat);
3373 out:
3374 	read_unlock(&policy_rwlock);
3375 	return rc;
3376 }
3377 
3378 /**
3379  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3380  * @sid: the SELinux SID
3381  * @secattr: the NetLabel packet security attributes
3382  *
3383  * Description:
3384  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3385  * Returns zero on success, negative values on failure.
3386  *
3387  */
3388 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3389 {
3390 	int rc;
3391 	struct context *ctx;
3392 
3393 	if (!ss_initialized)
3394 		return 0;
3395 
3396 	read_lock(&policy_rwlock);
3397 
3398 	rc = -ENOENT;
3399 	ctx = sidtab_search(&sidtab, sid);
3400 	if (ctx == NULL)
3401 		goto out;
3402 
3403 	rc = -ENOMEM;
3404 	secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3405 				  GFP_ATOMIC);
3406 	if (secattr->domain == NULL)
3407 		goto out;
3408 
3409 	secattr->attr.secid = sid;
3410 	secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3411 	mls_export_netlbl_lvl(ctx, secattr);
3412 	rc = mls_export_netlbl_cat(ctx, secattr);
3413 out:
3414 	read_unlock(&policy_rwlock);
3415 	return rc;
3416 }
3417 #endif /* CONFIG_NETLABEL */
3418 
3419 /**
3420  * security_read_policy - read the policy.
3421  * @data: binary policy data
3422  * @len: length of data in bytes
3423  *
3424  */
3425 int security_read_policy(void **data, size_t *len)
3426 {
3427 	int rc;
3428 	struct policy_file fp;
3429 
3430 	if (!ss_initialized)
3431 		return -EINVAL;
3432 
3433 	*len = security_policydb_len();
3434 
3435 	*data = vmalloc_user(*len);
3436 	if (!*data)
3437 		return -ENOMEM;
3438 
3439 	fp.data = *data;
3440 	fp.len = *len;
3441 
3442 	read_lock(&policy_rwlock);
3443 	rc = policydb_write(&policydb, &fp);
3444 	read_unlock(&policy_rwlock);
3445 
3446 	if (rc)
3447 		return rc;
3448 
3449 	*len = (unsigned long)fp.data - (unsigned long)*data;
3450 	return 0;
3451 
3452 }
3453