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UBUNTU: Ubuntu-4.10.0-37.41
[mirror_ubuntu-zesty-kernel.git] / security / selinux / ss / services.c
1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76
77 static DEFINE_RWLOCK(policy_rwlock);
78
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82
83 /*
84 * The largest sequence number that has been used when
85 * providing an access decision to the access vector cache.
86 * The sequence number only changes when a policy change
87 * occurs.
88 */
89 static u32 latest_granting;
90
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 u32 *scontext_len);
94
95 static void context_struct_compute_av(struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd,
99 struct extended_perms *xperms);
100
101 struct selinux_mapping {
102 u16 value; /* policy value */
103 unsigned num_perms;
104 u32 perms[sizeof(u32) * 8];
105 };
106
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109
110 static int selinux_set_mapping(struct policydb *pol,
111 struct security_class_mapping *map,
112 struct selinux_mapping **out_map_p,
113 u16 *out_map_size)
114 {
115 struct selinux_mapping *out_map = NULL;
116 size_t size = sizeof(struct selinux_mapping);
117 u16 i, j;
118 unsigned k;
119 bool print_unknown_handle = false;
120
121 /* Find number of classes in the input mapping */
122 if (!map)
123 return -EINVAL;
124 i = 0;
125 while (map[i].name)
126 i++;
127
128 /* Allocate space for the class records, plus one for class zero */
129 out_map = kcalloc(++i, size, GFP_ATOMIC);
130 if (!out_map)
131 return -ENOMEM;
132
133 /* Store the raw class and permission values */
134 j = 0;
135 while (map[j].name) {
136 struct security_class_mapping *p_in = map + (j++);
137 struct selinux_mapping *p_out = out_map + j;
138
139 /* An empty class string skips ahead */
140 if (!strcmp(p_in->name, "")) {
141 p_out->num_perms = 0;
142 continue;
143 }
144
145 p_out->value = string_to_security_class(pol, p_in->name);
146 if (!p_out->value) {
147 printk(KERN_INFO
148 "SELinux: Class %s not defined in policy.\n",
149 p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 p_out->num_perms = 0;
153 print_unknown_handle = true;
154 continue;
155 }
156
157 k = 0;
158 while (p_in->perms && p_in->perms[k]) {
159 /* An empty permission string skips ahead */
160 if (!*p_in->perms[k]) {
161 k++;
162 continue;
163 }
164 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 p_in->perms[k]);
166 if (!p_out->perms[k]) {
167 printk(KERN_INFO
168 "SELinux: Permission %s in class %s not defined in policy.\n",
169 p_in->perms[k], p_in->name);
170 if (pol->reject_unknown)
171 goto err;
172 print_unknown_handle = true;
173 }
174
175 k++;
176 }
177 p_out->num_perms = k;
178 }
179
180 if (print_unknown_handle)
181 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 pol->allow_unknown ? "allowed" : "denied");
183
184 *out_map_p = out_map;
185 *out_map_size = i;
186 return 0;
187 err:
188 kfree(out_map);
189 return -EINVAL;
190 }
191
192 /*
193 * Get real, policy values from mapped values
194 */
195
196 static u16 unmap_class(u16 tclass)
197 {
198 if (tclass < current_mapping_size)
199 return current_mapping[tclass].value;
200
201 return tclass;
202 }
203
204 /*
205 * Get kernel value for class from its policy value
206 */
207 static u16 map_class(u16 pol_value)
208 {
209 u16 i;
210
211 for (i = 1; i < current_mapping_size; i++) {
212 if (current_mapping[i].value == pol_value)
213 return i;
214 }
215
216 return SECCLASS_NULL;
217 }
218
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 int allow_unknown)
221 {
222 if (tclass < current_mapping_size) {
223 unsigned i, n = current_mapping[tclass].num_perms;
224 u32 result;
225
226 for (i = 0, result = 0; i < n; i++) {
227 if (avd->allowed & current_mapping[tclass].perms[i])
228 result |= 1<<i;
229 if (allow_unknown && !current_mapping[tclass].perms[i])
230 result |= 1<<i;
231 }
232 avd->allowed = result;
233
234 for (i = 0, result = 0; i < n; i++)
235 if (avd->auditallow & current_mapping[tclass].perms[i])
236 result |= 1<<i;
237 avd->auditallow = result;
238
239 for (i = 0, result = 0; i < n; i++) {
240 if (avd->auditdeny & current_mapping[tclass].perms[i])
241 result |= 1<<i;
242 if (!allow_unknown && !current_mapping[tclass].perms[i])
243 result |= 1<<i;
244 }
245 /*
246 * In case the kernel has a bug and requests a permission
247 * between num_perms and the maximum permission number, we
248 * should audit that denial
249 */
250 for (; i < (sizeof(u32)*8); i++)
251 result |= 1<<i;
252 avd->auditdeny = result;
253 }
254 }
255
256 int security_mls_enabled(void)
257 {
258 return policydb.mls_enabled;
259 }
260
261 /*
262 * Return the boolean value of a constraint expression
263 * when it is applied to the specified source and target
264 * security contexts.
265 *
266 * xcontext is a special beast... It is used by the validatetrans rules
267 * only. For these rules, scontext is the context before the transition,
268 * tcontext is the context after the transition, and xcontext is the context
269 * of the process performing the transition. All other callers of
270 * constraint_expr_eval should pass in NULL for xcontext.
271 */
272 static int constraint_expr_eval(struct context *scontext,
273 struct context *tcontext,
274 struct context *xcontext,
275 struct constraint_expr *cexpr)
276 {
277 u32 val1, val2;
278 struct context *c;
279 struct role_datum *r1, *r2;
280 struct mls_level *l1, *l2;
281 struct constraint_expr *e;
282 int s[CEXPR_MAXDEPTH];
283 int sp = -1;
284
285 for (e = cexpr; e; e = e->next) {
286 switch (e->expr_type) {
287 case CEXPR_NOT:
288 BUG_ON(sp < 0);
289 s[sp] = !s[sp];
290 break;
291 case CEXPR_AND:
292 BUG_ON(sp < 1);
293 sp--;
294 s[sp] &= s[sp + 1];
295 break;
296 case CEXPR_OR:
297 BUG_ON(sp < 1);
298 sp--;
299 s[sp] |= s[sp + 1];
300 break;
301 case CEXPR_ATTR:
302 if (sp == (CEXPR_MAXDEPTH - 1))
303 return 0;
304 switch (e->attr) {
305 case CEXPR_USER:
306 val1 = scontext->user;
307 val2 = tcontext->user;
308 break;
309 case CEXPR_TYPE:
310 val1 = scontext->type;
311 val2 = tcontext->type;
312 break;
313 case CEXPR_ROLE:
314 val1 = scontext->role;
315 val2 = tcontext->role;
316 r1 = policydb.role_val_to_struct[val1 - 1];
317 r2 = policydb.role_val_to_struct[val2 - 1];
318 switch (e->op) {
319 case CEXPR_DOM:
320 s[++sp] = ebitmap_get_bit(&r1->dominates,
321 val2 - 1);
322 continue;
323 case CEXPR_DOMBY:
324 s[++sp] = ebitmap_get_bit(&r2->dominates,
325 val1 - 1);
326 continue;
327 case CEXPR_INCOMP:
328 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 val2 - 1) &&
330 !ebitmap_get_bit(&r2->dominates,
331 val1 - 1));
332 continue;
333 default:
334 break;
335 }
336 break;
337 case CEXPR_L1L2:
338 l1 = &(scontext->range.level[0]);
339 l2 = &(tcontext->range.level[0]);
340 goto mls_ops;
341 case CEXPR_L1H2:
342 l1 = &(scontext->range.level[0]);
343 l2 = &(tcontext->range.level[1]);
344 goto mls_ops;
345 case CEXPR_H1L2:
346 l1 = &(scontext->range.level[1]);
347 l2 = &(tcontext->range.level[0]);
348 goto mls_ops;
349 case CEXPR_H1H2:
350 l1 = &(scontext->range.level[1]);
351 l2 = &(tcontext->range.level[1]);
352 goto mls_ops;
353 case CEXPR_L1H1:
354 l1 = &(scontext->range.level[0]);
355 l2 = &(scontext->range.level[1]);
356 goto mls_ops;
357 case CEXPR_L2H2:
358 l1 = &(tcontext->range.level[0]);
359 l2 = &(tcontext->range.level[1]);
360 goto mls_ops;
361 mls_ops:
362 switch (e->op) {
363 case CEXPR_EQ:
364 s[++sp] = mls_level_eq(l1, l2);
365 continue;
366 case CEXPR_NEQ:
367 s[++sp] = !mls_level_eq(l1, l2);
368 continue;
369 case CEXPR_DOM:
370 s[++sp] = mls_level_dom(l1, l2);
371 continue;
372 case CEXPR_DOMBY:
373 s[++sp] = mls_level_dom(l2, l1);
374 continue;
375 case CEXPR_INCOMP:
376 s[++sp] = mls_level_incomp(l2, l1);
377 continue;
378 default:
379 BUG();
380 return 0;
381 }
382 break;
383 default:
384 BUG();
385 return 0;
386 }
387
388 switch (e->op) {
389 case CEXPR_EQ:
390 s[++sp] = (val1 == val2);
391 break;
392 case CEXPR_NEQ:
393 s[++sp] = (val1 != val2);
394 break;
395 default:
396 BUG();
397 return 0;
398 }
399 break;
400 case CEXPR_NAMES:
401 if (sp == (CEXPR_MAXDEPTH-1))
402 return 0;
403 c = scontext;
404 if (e->attr & CEXPR_TARGET)
405 c = tcontext;
406 else if (e->attr & CEXPR_XTARGET) {
407 c = xcontext;
408 if (!c) {
409 BUG();
410 return 0;
411 }
412 }
413 if (e->attr & CEXPR_USER)
414 val1 = c->user;
415 else if (e->attr & CEXPR_ROLE)
416 val1 = c->role;
417 else if (e->attr & CEXPR_TYPE)
418 val1 = c->type;
419 else {
420 BUG();
421 return 0;
422 }
423
424 switch (e->op) {
425 case CEXPR_EQ:
426 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 break;
428 case CEXPR_NEQ:
429 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 break;
431 default:
432 BUG();
433 return 0;
434 }
435 break;
436 default:
437 BUG();
438 return 0;
439 }
440 }
441
442 BUG_ON(sp != 0);
443 return s[0];
444 }
445
446 /*
447 * security_dump_masked_av - dumps masked permissions during
448 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449 */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 struct perm_datum *pdatum = d;
453 char **permission_names = args;
454
455 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456
457 permission_names[pdatum->value - 1] = (char *)k;
458
459 return 0;
460 }
461
462 static void security_dump_masked_av(struct context *scontext,
463 struct context *tcontext,
464 u16 tclass,
465 u32 permissions,
466 const char *reason)
467 {
468 struct common_datum *common_dat;
469 struct class_datum *tclass_dat;
470 struct audit_buffer *ab;
471 char *tclass_name;
472 char *scontext_name = NULL;
473 char *tcontext_name = NULL;
474 char *permission_names[32];
475 int index;
476 u32 length;
477 bool need_comma = false;
478
479 if (!permissions)
480 return;
481
482 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 common_dat = tclass_dat->comdatum;
485
486 /* init permission_names */
487 if (common_dat &&
488 hashtab_map(common_dat->permissions.table,
489 dump_masked_av_helper, permission_names) < 0)
490 goto out;
491
492 if (hashtab_map(tclass_dat->permissions.table,
493 dump_masked_av_helper, permission_names) < 0)
494 goto out;
495
496 /* get scontext/tcontext in text form */
497 if (context_struct_to_string(scontext,
498 &scontext_name, &length) < 0)
499 goto out;
500
501 if (context_struct_to_string(tcontext,
502 &tcontext_name, &length) < 0)
503 goto out;
504
505 /* audit a message */
506 ab = audit_log_start(current->audit_context,
507 GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 if (!ab)
509 goto out;
510
511 audit_log_format(ab, "op=security_compute_av reason=%s "
512 "scontext=%s tcontext=%s tclass=%s perms=",
513 reason, scontext_name, tcontext_name, tclass_name);
514
515 for (index = 0; index < 32; index++) {
516 u32 mask = (1 << index);
517
518 if ((mask & permissions) == 0)
519 continue;
520
521 audit_log_format(ab, "%s%s",
522 need_comma ? "," : "",
523 permission_names[index]
524 ? permission_names[index] : "????");
525 need_comma = true;
526 }
527 audit_log_end(ab);
528 out:
529 /* release scontext/tcontext */
530 kfree(tcontext_name);
531 kfree(scontext_name);
532
533 return;
534 }
535
536 /*
537 * security_boundary_permission - drops violated permissions
538 * on boundary constraint.
539 */
540 static void type_attribute_bounds_av(struct context *scontext,
541 struct context *tcontext,
542 u16 tclass,
543 struct av_decision *avd)
544 {
545 struct context lo_scontext;
546 struct context lo_tcontext, *tcontextp = tcontext;
547 struct av_decision lo_avd;
548 struct type_datum *source;
549 struct type_datum *target;
550 u32 masked = 0;
551
552 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 scontext->type - 1);
554 BUG_ON(!source);
555
556 if (!source->bounds)
557 return;
558
559 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
560 tcontext->type - 1);
561 BUG_ON(!target);
562
563 memset(&lo_avd, 0, sizeof(lo_avd));
564
565 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
566 lo_scontext.type = source->bounds;
567
568 if (target->bounds) {
569 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
570 lo_tcontext.type = target->bounds;
571 tcontextp = &lo_tcontext;
572 }
573
574 context_struct_compute_av(&lo_scontext,
575 tcontextp,
576 tclass,
577 &lo_avd,
578 NULL);
579
580 masked = ~lo_avd.allowed & avd->allowed;
581
582 if (likely(!masked))
583 return; /* no masked permission */
584
585 /* mask violated permissions */
586 avd->allowed &= ~masked;
587
588 /* audit masked permissions */
589 security_dump_masked_av(scontext, tcontext,
590 tclass, masked, "bounds");
591 }
592
593 /*
594 * flag which drivers have permissions
595 * only looking for ioctl based extended permssions
596 */
597 void services_compute_xperms_drivers(
598 struct extended_perms *xperms,
599 struct avtab_node *node)
600 {
601 unsigned int i;
602
603 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
604 /* if one or more driver has all permissions allowed */
605 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
606 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
607 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
608 /* if allowing permissions within a driver */
609 security_xperm_set(xperms->drivers.p,
610 node->datum.u.xperms->driver);
611 }
612
613 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
614 if (node->key.specified & AVTAB_XPERMS_ALLOWED)
615 xperms->len = 1;
616 }
617
618 /*
619 * Compute access vectors and extended permissions based on a context
620 * structure pair for the permissions in a particular class.
621 */
622 static void context_struct_compute_av(struct context *scontext,
623 struct context *tcontext,
624 u16 tclass,
625 struct av_decision *avd,
626 struct extended_perms *xperms)
627 {
628 struct constraint_node *constraint;
629 struct role_allow *ra;
630 struct avtab_key avkey;
631 struct avtab_node *node;
632 struct class_datum *tclass_datum;
633 struct ebitmap *sattr, *tattr;
634 struct ebitmap_node *snode, *tnode;
635 unsigned int i, j;
636
637 avd->allowed = 0;
638 avd->auditallow = 0;
639 avd->auditdeny = 0xffffffff;
640 if (xperms) {
641 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
642 xperms->len = 0;
643 }
644
645 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
646 if (printk_ratelimit())
647 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
648 return;
649 }
650
651 tclass_datum = policydb.class_val_to_struct[tclass - 1];
652
653 /*
654 * If a specific type enforcement rule was defined for
655 * this permission check, then use it.
656 */
657 avkey.target_class = tclass;
658 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
659 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
660 BUG_ON(!sattr);
661 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
662 BUG_ON(!tattr);
663 ebitmap_for_each_positive_bit(sattr, snode, i) {
664 ebitmap_for_each_positive_bit(tattr, tnode, j) {
665 avkey.source_type = i + 1;
666 avkey.target_type = j + 1;
667 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
668 node;
669 node = avtab_search_node_next(node, avkey.specified)) {
670 if (node->key.specified == AVTAB_ALLOWED)
671 avd->allowed |= node->datum.u.data;
672 else if (node->key.specified == AVTAB_AUDITALLOW)
673 avd->auditallow |= node->datum.u.data;
674 else if (node->key.specified == AVTAB_AUDITDENY)
675 avd->auditdeny &= node->datum.u.data;
676 else if (xperms && (node->key.specified & AVTAB_XPERMS))
677 services_compute_xperms_drivers(xperms, node);
678 }
679
680 /* Check conditional av table for additional permissions */
681 cond_compute_av(&policydb.te_cond_avtab, &avkey,
682 avd, xperms);
683
684 }
685 }
686
687 /*
688 * Remove any permissions prohibited by a constraint (this includes
689 * the MLS policy).
690 */
691 constraint = tclass_datum->constraints;
692 while (constraint) {
693 if ((constraint->permissions & (avd->allowed)) &&
694 !constraint_expr_eval(scontext, tcontext, NULL,
695 constraint->expr)) {
696 avd->allowed &= ~(constraint->permissions);
697 }
698 constraint = constraint->next;
699 }
700
701 /*
702 * If checking process transition permission and the
703 * role is changing, then check the (current_role, new_role)
704 * pair.
705 */
706 if (tclass == policydb.process_class &&
707 (avd->allowed & policydb.process_trans_perms) &&
708 scontext->role != tcontext->role) {
709 for (ra = policydb.role_allow; ra; ra = ra->next) {
710 if (scontext->role == ra->role &&
711 tcontext->role == ra->new_role)
712 break;
713 }
714 if (!ra)
715 avd->allowed &= ~policydb.process_trans_perms;
716 }
717
718 /*
719 * If the given source and target types have boundary
720 * constraint, lazy checks have to mask any violated
721 * permission and notice it to userspace via audit.
722 */
723 type_attribute_bounds_av(scontext, tcontext,
724 tclass, avd);
725 }
726
727 static int security_validtrans_handle_fail(struct context *ocontext,
728 struct context *ncontext,
729 struct context *tcontext,
730 u16 tclass)
731 {
732 char *o = NULL, *n = NULL, *t = NULL;
733 u32 olen, nlen, tlen;
734
735 if (context_struct_to_string(ocontext, &o, &olen))
736 goto out;
737 if (context_struct_to_string(ncontext, &n, &nlen))
738 goto out;
739 if (context_struct_to_string(tcontext, &t, &tlen))
740 goto out;
741 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
742 "op=security_validate_transition seresult=denied"
743 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
744 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
745 out:
746 kfree(o);
747 kfree(n);
748 kfree(t);
749
750 if (!selinux_enforcing)
751 return 0;
752 return -EPERM;
753 }
754
755 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
756 u16 orig_tclass, bool user)
757 {
758 struct context *ocontext;
759 struct context *ncontext;
760 struct context *tcontext;
761 struct class_datum *tclass_datum;
762 struct constraint_node *constraint;
763 u16 tclass;
764 int rc = 0;
765
766 if (!ss_initialized)
767 return 0;
768
769 read_lock(&policy_rwlock);
770
771 if (!user)
772 tclass = unmap_class(orig_tclass);
773 else
774 tclass = orig_tclass;
775
776 if (!tclass || tclass > policydb.p_classes.nprim) {
777 rc = -EINVAL;
778 goto out;
779 }
780 tclass_datum = policydb.class_val_to_struct[tclass - 1];
781
782 ocontext = sidtab_search(&sidtab, oldsid);
783 if (!ocontext) {
784 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
785 __func__, oldsid);
786 rc = -EINVAL;
787 goto out;
788 }
789
790 ncontext = sidtab_search(&sidtab, newsid);
791 if (!ncontext) {
792 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
793 __func__, newsid);
794 rc = -EINVAL;
795 goto out;
796 }
797
798 tcontext = sidtab_search(&sidtab, tasksid);
799 if (!tcontext) {
800 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
801 __func__, tasksid);
802 rc = -EINVAL;
803 goto out;
804 }
805
806 constraint = tclass_datum->validatetrans;
807 while (constraint) {
808 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
809 constraint->expr)) {
810 if (user)
811 rc = -EPERM;
812 else
813 rc = security_validtrans_handle_fail(ocontext,
814 ncontext,
815 tcontext,
816 tclass);
817 goto out;
818 }
819 constraint = constraint->next;
820 }
821
822 out:
823 read_unlock(&policy_rwlock);
824 return rc;
825 }
826
827 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
828 u16 tclass)
829 {
830 return security_compute_validatetrans(oldsid, newsid, tasksid,
831 tclass, true);
832 }
833
834 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
835 u16 orig_tclass)
836 {
837 return security_compute_validatetrans(oldsid, newsid, tasksid,
838 orig_tclass, false);
839 }
840
841 /*
842 * security_bounded_transition - check whether the given
843 * transition is directed to bounded, or not.
844 * It returns 0, if @newsid is bounded by @oldsid.
845 * Otherwise, it returns error code.
846 *
847 * @oldsid : current security identifier
848 * @newsid : destinated security identifier
849 */
850 int security_bounded_transition(u32 old_sid, u32 new_sid)
851 {
852 struct context *old_context, *new_context;
853 struct type_datum *type;
854 int index;
855 int rc;
856
857 read_lock(&policy_rwlock);
858
859 rc = -EINVAL;
860 old_context = sidtab_search(&sidtab, old_sid);
861 if (!old_context) {
862 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
863 __func__, old_sid);
864 goto out;
865 }
866
867 rc = -EINVAL;
868 new_context = sidtab_search(&sidtab, new_sid);
869 if (!new_context) {
870 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
871 __func__, new_sid);
872 goto out;
873 }
874
875 rc = 0;
876 /* type/domain unchanged */
877 if (old_context->type == new_context->type)
878 goto out;
879
880 index = new_context->type;
881 while (true) {
882 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
883 index - 1);
884 BUG_ON(!type);
885
886 /* not bounded anymore */
887 rc = -EPERM;
888 if (!type->bounds)
889 break;
890
891 /* @newsid is bounded by @oldsid */
892 rc = 0;
893 if (type->bounds == old_context->type)
894 break;
895
896 index = type->bounds;
897 }
898
899 if (rc) {
900 char *old_name = NULL;
901 char *new_name = NULL;
902 u32 length;
903
904 if (!context_struct_to_string(old_context,
905 &old_name, &length) &&
906 !context_struct_to_string(new_context,
907 &new_name, &length)) {
908 audit_log(current->audit_context,
909 GFP_ATOMIC, AUDIT_SELINUX_ERR,
910 "op=security_bounded_transition "
911 "seresult=denied "
912 "oldcontext=%s newcontext=%s",
913 old_name, new_name);
914 }
915 kfree(new_name);
916 kfree(old_name);
917 }
918 out:
919 read_unlock(&policy_rwlock);
920
921 return rc;
922 }
923
924 static void avd_init(struct av_decision *avd)
925 {
926 avd->allowed = 0;
927 avd->auditallow = 0;
928 avd->auditdeny = 0xffffffff;
929 avd->seqno = latest_granting;
930 avd->flags = 0;
931 }
932
933 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
934 struct avtab_node *node)
935 {
936 unsigned int i;
937
938 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
939 if (xpermd->driver != node->datum.u.xperms->driver)
940 return;
941 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
942 if (!security_xperm_test(node->datum.u.xperms->perms.p,
943 xpermd->driver))
944 return;
945 } else {
946 BUG();
947 }
948
949 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
950 xpermd->used |= XPERMS_ALLOWED;
951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
952 memset(xpermd->allowed->p, 0xff,
953 sizeof(xpermd->allowed->p));
954 }
955 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
956 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
957 xpermd->allowed->p[i] |=
958 node->datum.u.xperms->perms.p[i];
959 }
960 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
961 xpermd->used |= XPERMS_AUDITALLOW;
962 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
963 memset(xpermd->auditallow->p, 0xff,
964 sizeof(xpermd->auditallow->p));
965 }
966 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
967 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
968 xpermd->auditallow->p[i] |=
969 node->datum.u.xperms->perms.p[i];
970 }
971 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
972 xpermd->used |= XPERMS_DONTAUDIT;
973 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
974 memset(xpermd->dontaudit->p, 0xff,
975 sizeof(xpermd->dontaudit->p));
976 }
977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
978 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
979 xpermd->dontaudit->p[i] |=
980 node->datum.u.xperms->perms.p[i];
981 }
982 } else {
983 BUG();
984 }
985 }
986
987 void security_compute_xperms_decision(u32 ssid,
988 u32 tsid,
989 u16 orig_tclass,
990 u8 driver,
991 struct extended_perms_decision *xpermd)
992 {
993 u16 tclass;
994 struct context *scontext, *tcontext;
995 struct avtab_key avkey;
996 struct avtab_node *node;
997 struct ebitmap *sattr, *tattr;
998 struct ebitmap_node *snode, *tnode;
999 unsigned int i, j;
1000
1001 xpermd->driver = driver;
1002 xpermd->used = 0;
1003 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1004 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1005 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1006
1007 read_lock(&policy_rwlock);
1008 if (!ss_initialized)
1009 goto allow;
1010
1011 scontext = sidtab_search(&sidtab, ssid);
1012 if (!scontext) {
1013 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1014 __func__, ssid);
1015 goto out;
1016 }
1017
1018 tcontext = sidtab_search(&sidtab, tsid);
1019 if (!tcontext) {
1020 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1021 __func__, tsid);
1022 goto out;
1023 }
1024
1025 tclass = unmap_class(orig_tclass);
1026 if (unlikely(orig_tclass && !tclass)) {
1027 if (policydb.allow_unknown)
1028 goto allow;
1029 goto out;
1030 }
1031
1032
1033 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1034 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1035 goto out;
1036 }
1037
1038 avkey.target_class = tclass;
1039 avkey.specified = AVTAB_XPERMS;
1040 sattr = flex_array_get(policydb.type_attr_map_array,
1041 scontext->type - 1);
1042 BUG_ON(!sattr);
1043 tattr = flex_array_get(policydb.type_attr_map_array,
1044 tcontext->type - 1);
1045 BUG_ON(!tattr);
1046 ebitmap_for_each_positive_bit(sattr, snode, i) {
1047 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1048 avkey.source_type = i + 1;
1049 avkey.target_type = j + 1;
1050 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1051 node;
1052 node = avtab_search_node_next(node, avkey.specified))
1053 services_compute_xperms_decision(xpermd, node);
1054
1055 cond_compute_xperms(&policydb.te_cond_avtab,
1056 &avkey, xpermd);
1057 }
1058 }
1059 out:
1060 read_unlock(&policy_rwlock);
1061 return;
1062 allow:
1063 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1064 goto out;
1065 }
1066
1067 /**
1068 * security_compute_av - Compute access vector decisions.
1069 * @ssid: source security identifier
1070 * @tsid: target security identifier
1071 * @tclass: target security class
1072 * @avd: access vector decisions
1073 * @xperms: extended permissions
1074 *
1075 * Compute a set of access vector decisions based on the
1076 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1077 */
1078 void security_compute_av(u32 ssid,
1079 u32 tsid,
1080 u16 orig_tclass,
1081 struct av_decision *avd,
1082 struct extended_perms *xperms)
1083 {
1084 u16 tclass;
1085 struct context *scontext = NULL, *tcontext = NULL;
1086
1087 read_lock(&policy_rwlock);
1088 avd_init(avd);
1089 xperms->len = 0;
1090 if (!ss_initialized)
1091 goto allow;
1092
1093 scontext = sidtab_search(&sidtab, ssid);
1094 if (!scontext) {
1095 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1096 __func__, ssid);
1097 goto out;
1098 }
1099
1100 /* permissive domain? */
1101 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1102 avd->flags |= AVD_FLAGS_PERMISSIVE;
1103
1104 tcontext = sidtab_search(&sidtab, tsid);
1105 if (!tcontext) {
1106 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1107 __func__, tsid);
1108 goto out;
1109 }
1110
1111 tclass = unmap_class(orig_tclass);
1112 if (unlikely(orig_tclass && !tclass)) {
1113 if (policydb.allow_unknown)
1114 goto allow;
1115 goto out;
1116 }
1117 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1118 map_decision(orig_tclass, avd, policydb.allow_unknown);
1119 out:
1120 read_unlock(&policy_rwlock);
1121 return;
1122 allow:
1123 avd->allowed = 0xffffffff;
1124 goto out;
1125 }
1126
1127 void security_compute_av_user(u32 ssid,
1128 u32 tsid,
1129 u16 tclass,
1130 struct av_decision *avd)
1131 {
1132 struct context *scontext = NULL, *tcontext = NULL;
1133
1134 read_lock(&policy_rwlock);
1135 avd_init(avd);
1136 if (!ss_initialized)
1137 goto allow;
1138
1139 scontext = sidtab_search(&sidtab, ssid);
1140 if (!scontext) {
1141 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1142 __func__, ssid);
1143 goto out;
1144 }
1145
1146 /* permissive domain? */
1147 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1148 avd->flags |= AVD_FLAGS_PERMISSIVE;
1149
1150 tcontext = sidtab_search(&sidtab, tsid);
1151 if (!tcontext) {
1152 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1153 __func__, tsid);
1154 goto out;
1155 }
1156
1157 if (unlikely(!tclass)) {
1158 if (policydb.allow_unknown)
1159 goto allow;
1160 goto out;
1161 }
1162
1163 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1164 out:
1165 read_unlock(&policy_rwlock);
1166 return;
1167 allow:
1168 avd->allowed = 0xffffffff;
1169 goto out;
1170 }
1171
1172 /*
1173 * Write the security context string representation of
1174 * the context structure `context' into a dynamically
1175 * allocated string of the correct size. Set `*scontext'
1176 * to point to this string and set `*scontext_len' to
1177 * the length of the string.
1178 */
1179 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1180 {
1181 char *scontextp;
1182
1183 if (scontext)
1184 *scontext = NULL;
1185 *scontext_len = 0;
1186
1187 if (context->len) {
1188 *scontext_len = context->len;
1189 if (scontext) {
1190 *scontext = kstrdup(context->str, GFP_ATOMIC);
1191 if (!(*scontext))
1192 return -ENOMEM;
1193 }
1194 return 0;
1195 }
1196
1197 /* Compute the size of the context. */
1198 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1199 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1200 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1201 *scontext_len += mls_compute_context_len(context);
1202
1203 if (!scontext)
1204 return 0;
1205
1206 /* Allocate space for the context; caller must free this space. */
1207 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1208 if (!scontextp)
1209 return -ENOMEM;
1210 *scontext = scontextp;
1211
1212 /*
1213 * Copy the user name, role name and type name into the context.
1214 */
1215 scontextp += sprintf(scontextp, "%s:%s:%s",
1216 sym_name(&policydb, SYM_USERS, context->user - 1),
1217 sym_name(&policydb, SYM_ROLES, context->role - 1),
1218 sym_name(&policydb, SYM_TYPES, context->type - 1));
1219
1220 mls_sid_to_context(context, &scontextp);
1221
1222 *scontextp = 0;
1223
1224 return 0;
1225 }
1226
1227 #include "initial_sid_to_string.h"
1228
1229 const char *security_get_initial_sid_context(u32 sid)
1230 {
1231 if (unlikely(sid > SECINITSID_NUM))
1232 return NULL;
1233 return initial_sid_to_string[sid];
1234 }
1235
1236 static int security_sid_to_context_core(u32 sid, char **scontext,
1237 u32 *scontext_len, int force)
1238 {
1239 struct context *context;
1240 int rc = 0;
1241
1242 if (scontext)
1243 *scontext = NULL;
1244 *scontext_len = 0;
1245
1246 if (!ss_initialized) {
1247 if (sid <= SECINITSID_NUM) {
1248 char *scontextp;
1249
1250 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1251 if (!scontext)
1252 goto out;
1253 scontextp = kmemdup(initial_sid_to_string[sid],
1254 *scontext_len, GFP_ATOMIC);
1255 if (!scontextp) {
1256 rc = -ENOMEM;
1257 goto out;
1258 }
1259 *scontext = scontextp;
1260 goto out;
1261 }
1262 printk(KERN_ERR "SELinux: %s: called before initial "
1263 "load_policy on unknown SID %d\n", __func__, sid);
1264 rc = -EINVAL;
1265 goto out;
1266 }
1267 read_lock(&policy_rwlock);
1268 if (force)
1269 context = sidtab_search_force(&sidtab, sid);
1270 else
1271 context = sidtab_search(&sidtab, sid);
1272 if (!context) {
1273 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1274 __func__, sid);
1275 rc = -EINVAL;
1276 goto out_unlock;
1277 }
1278 rc = context_struct_to_string(context, scontext, scontext_len);
1279 out_unlock:
1280 read_unlock(&policy_rwlock);
1281 out:
1282 return rc;
1283
1284 }
1285
1286 /**
1287 * security_sid_to_context - Obtain a context for a given SID.
1288 * @sid: security identifier, SID
1289 * @scontext: security context
1290 * @scontext_len: length in bytes
1291 *
1292 * Write the string representation of the context associated with @sid
1293 * into a dynamically allocated string of the correct size. Set @scontext
1294 * to point to this string and set @scontext_len to the length of the string.
1295 */
1296 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1297 {
1298 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1299 }
1300
1301 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1302 {
1303 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1304 }
1305
1306 /*
1307 * Caveat: Mutates scontext.
1308 */
1309 static int string_to_context_struct(struct policydb *pol,
1310 struct sidtab *sidtabp,
1311 char *scontext,
1312 u32 scontext_len,
1313 struct context *ctx,
1314 u32 def_sid)
1315 {
1316 struct role_datum *role;
1317 struct type_datum *typdatum;
1318 struct user_datum *usrdatum;
1319 char *scontextp, *p, oldc;
1320 int rc = 0;
1321
1322 context_init(ctx);
1323
1324 /* Parse the security context. */
1325
1326 rc = -EINVAL;
1327 scontextp = (char *) scontext;
1328
1329 /* Extract the user. */
1330 p = scontextp;
1331 while (*p && *p != ':')
1332 p++;
1333
1334 if (*p == 0)
1335 goto out;
1336
1337 *p++ = 0;
1338
1339 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1340 if (!usrdatum)
1341 goto out;
1342
1343 ctx->user = usrdatum->value;
1344
1345 /* Extract role. */
1346 scontextp = p;
1347 while (*p && *p != ':')
1348 p++;
1349
1350 if (*p == 0)
1351 goto out;
1352
1353 *p++ = 0;
1354
1355 role = hashtab_search(pol->p_roles.table, scontextp);
1356 if (!role)
1357 goto out;
1358 ctx->role = role->value;
1359
1360 /* Extract type. */
1361 scontextp = p;
1362 while (*p && *p != ':')
1363 p++;
1364 oldc = *p;
1365 *p++ = 0;
1366
1367 typdatum = hashtab_search(pol->p_types.table, scontextp);
1368 if (!typdatum || typdatum->attribute)
1369 goto out;
1370
1371 ctx->type = typdatum->value;
1372
1373 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1374 if (rc)
1375 goto out;
1376
1377 rc = -EINVAL;
1378 if ((p - scontext) < scontext_len)
1379 goto out;
1380
1381 /* Check the validity of the new context. */
1382 if (!policydb_context_isvalid(pol, ctx))
1383 goto out;
1384 rc = 0;
1385 out:
1386 if (rc)
1387 context_destroy(ctx);
1388 return rc;
1389 }
1390
1391 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1392 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1393 int force)
1394 {
1395 char *scontext2, *str = NULL;
1396 struct context context;
1397 int rc = 0;
1398
1399 /* An empty security context is never valid. */
1400 if (!scontext_len)
1401 return -EINVAL;
1402
1403 if (!ss_initialized) {
1404 int i;
1405
1406 for (i = 1; i < SECINITSID_NUM; i++) {
1407 if (!strcmp(initial_sid_to_string[i], scontext)) {
1408 *sid = i;
1409 return 0;
1410 }
1411 }
1412 *sid = SECINITSID_KERNEL;
1413 return 0;
1414 }
1415 *sid = SECSID_NULL;
1416
1417 /* Copy the string so that we can modify the copy as we parse it. */
1418 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1419 if (!scontext2)
1420 return -ENOMEM;
1421 memcpy(scontext2, scontext, scontext_len);
1422 scontext2[scontext_len] = 0;
1423
1424 if (force) {
1425 /* Save another copy for storing in uninterpreted form */
1426 rc = -ENOMEM;
1427 str = kstrdup(scontext2, gfp_flags);
1428 if (!str)
1429 goto out;
1430 }
1431
1432 read_lock(&policy_rwlock);
1433 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1434 scontext_len, &context, def_sid);
1435 if (rc == -EINVAL && force) {
1436 context.str = str;
1437 context.len = scontext_len;
1438 str = NULL;
1439 } else if (rc)
1440 goto out_unlock;
1441 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1442 context_destroy(&context);
1443 out_unlock:
1444 read_unlock(&policy_rwlock);
1445 out:
1446 kfree(scontext2);
1447 kfree(str);
1448 return rc;
1449 }
1450
1451 /**
1452 * security_context_to_sid - Obtain a SID for a given security context.
1453 * @scontext: security context
1454 * @scontext_len: length in bytes
1455 * @sid: security identifier, SID
1456 * @gfp: context for the allocation
1457 *
1458 * Obtains a SID associated with the security context that
1459 * has the string representation specified by @scontext.
1460 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1461 * memory is available, or 0 on success.
1462 */
1463 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1464 gfp_t gfp)
1465 {
1466 return security_context_to_sid_core(scontext, scontext_len,
1467 sid, SECSID_NULL, gfp, 0);
1468 }
1469
1470 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1471 {
1472 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1473 }
1474
1475 /**
1476 * security_context_to_sid_default - Obtain a SID for a given security context,
1477 * falling back to specified default if needed.
1478 *
1479 * @scontext: security context
1480 * @scontext_len: length in bytes
1481 * @sid: security identifier, SID
1482 * @def_sid: default SID to assign on error
1483 *
1484 * Obtains a SID associated with the security context that
1485 * has the string representation specified by @scontext.
1486 * The default SID is passed to the MLS layer to be used to allow
1487 * kernel labeling of the MLS field if the MLS field is not present
1488 * (for upgrading to MLS without full relabel).
1489 * Implicitly forces adding of the context even if it cannot be mapped yet.
1490 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1491 * memory is available, or 0 on success.
1492 */
1493 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1494 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1495 {
1496 return security_context_to_sid_core(scontext, scontext_len,
1497 sid, def_sid, gfp_flags, 1);
1498 }
1499
1500 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1501 u32 *sid)
1502 {
1503 return security_context_to_sid_core(scontext, scontext_len,
1504 sid, SECSID_NULL, GFP_KERNEL, 1);
1505 }
1506
1507 static int compute_sid_handle_invalid_context(
1508 struct context *scontext,
1509 struct context *tcontext,
1510 u16 tclass,
1511 struct context *newcontext)
1512 {
1513 char *s = NULL, *t = NULL, *n = NULL;
1514 u32 slen, tlen, nlen;
1515
1516 if (context_struct_to_string(scontext, &s, &slen))
1517 goto out;
1518 if (context_struct_to_string(tcontext, &t, &tlen))
1519 goto out;
1520 if (context_struct_to_string(newcontext, &n, &nlen))
1521 goto out;
1522 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1523 "op=security_compute_sid invalid_context=%s"
1524 " scontext=%s"
1525 " tcontext=%s"
1526 " tclass=%s",
1527 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1528 out:
1529 kfree(s);
1530 kfree(t);
1531 kfree(n);
1532 if (!selinux_enforcing)
1533 return 0;
1534 return -EACCES;
1535 }
1536
1537 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1538 u32 stype, u32 ttype, u16 tclass,
1539 const char *objname)
1540 {
1541 struct filename_trans ft;
1542 struct filename_trans_datum *otype;
1543
1544 /*
1545 * Most filename trans rules are going to live in specific directories
1546 * like /dev or /var/run. This bitmap will quickly skip rule searches
1547 * if the ttype does not contain any rules.
1548 */
1549 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1550 return;
1551
1552 ft.stype = stype;
1553 ft.ttype = ttype;
1554 ft.tclass = tclass;
1555 ft.name = objname;
1556
1557 otype = hashtab_search(p->filename_trans, &ft);
1558 if (otype)
1559 newcontext->type = otype->otype;
1560 }
1561
1562 static int security_compute_sid(u32 ssid,
1563 u32 tsid,
1564 u16 orig_tclass,
1565 u32 specified,
1566 const char *objname,
1567 u32 *out_sid,
1568 bool kern)
1569 {
1570 struct class_datum *cladatum = NULL;
1571 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1572 struct role_trans *roletr = NULL;
1573 struct avtab_key avkey;
1574 struct avtab_datum *avdatum;
1575 struct avtab_node *node;
1576 u16 tclass;
1577 int rc = 0;
1578 bool sock;
1579
1580 if (!ss_initialized) {
1581 switch (orig_tclass) {
1582 case SECCLASS_PROCESS: /* kernel value */
1583 *out_sid = ssid;
1584 break;
1585 default:
1586 *out_sid = tsid;
1587 break;
1588 }
1589 goto out;
1590 }
1591
1592 context_init(&newcontext);
1593
1594 read_lock(&policy_rwlock);
1595
1596 if (kern) {
1597 tclass = unmap_class(orig_tclass);
1598 sock = security_is_socket_class(orig_tclass);
1599 } else {
1600 tclass = orig_tclass;
1601 sock = security_is_socket_class(map_class(tclass));
1602 }
1603
1604 scontext = sidtab_search(&sidtab, ssid);
1605 if (!scontext) {
1606 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1607 __func__, ssid);
1608 rc = -EINVAL;
1609 goto out_unlock;
1610 }
1611 tcontext = sidtab_search(&sidtab, tsid);
1612 if (!tcontext) {
1613 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1614 __func__, tsid);
1615 rc = -EINVAL;
1616 goto out_unlock;
1617 }
1618
1619 if (tclass && tclass <= policydb.p_classes.nprim)
1620 cladatum = policydb.class_val_to_struct[tclass - 1];
1621
1622 /* Set the user identity. */
1623 switch (specified) {
1624 case AVTAB_TRANSITION:
1625 case AVTAB_CHANGE:
1626 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1627 newcontext.user = tcontext->user;
1628 } else {
1629 /* notice this gets both DEFAULT_SOURCE and unset */
1630 /* Use the process user identity. */
1631 newcontext.user = scontext->user;
1632 }
1633 break;
1634 case AVTAB_MEMBER:
1635 /* Use the related object owner. */
1636 newcontext.user = tcontext->user;
1637 break;
1638 }
1639
1640 /* Set the role to default values. */
1641 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1642 newcontext.role = scontext->role;
1643 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1644 newcontext.role = tcontext->role;
1645 } else {
1646 if ((tclass == policydb.process_class) || (sock == true))
1647 newcontext.role = scontext->role;
1648 else
1649 newcontext.role = OBJECT_R_VAL;
1650 }
1651
1652 /* Set the type to default values. */
1653 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1654 newcontext.type = scontext->type;
1655 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1656 newcontext.type = tcontext->type;
1657 } else {
1658 if ((tclass == policydb.process_class) || (sock == true)) {
1659 /* Use the type of process. */
1660 newcontext.type = scontext->type;
1661 } else {
1662 /* Use the type of the related object. */
1663 newcontext.type = tcontext->type;
1664 }
1665 }
1666
1667 /* Look for a type transition/member/change rule. */
1668 avkey.source_type = scontext->type;
1669 avkey.target_type = tcontext->type;
1670 avkey.target_class = tclass;
1671 avkey.specified = specified;
1672 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1673
1674 /* If no permanent rule, also check for enabled conditional rules */
1675 if (!avdatum) {
1676 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1677 for (; node; node = avtab_search_node_next(node, specified)) {
1678 if (node->key.specified & AVTAB_ENABLED) {
1679 avdatum = &node->datum;
1680 break;
1681 }
1682 }
1683 }
1684
1685 if (avdatum) {
1686 /* Use the type from the type transition/member/change rule. */
1687 newcontext.type = avdatum->u.data;
1688 }
1689
1690 /* if we have a objname this is a file trans check so check those rules */
1691 if (objname)
1692 filename_compute_type(&policydb, &newcontext, scontext->type,
1693 tcontext->type, tclass, objname);
1694
1695 /* Check for class-specific changes. */
1696 if (specified & AVTAB_TRANSITION) {
1697 /* Look for a role transition rule. */
1698 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1699 if ((roletr->role == scontext->role) &&
1700 (roletr->type == tcontext->type) &&
1701 (roletr->tclass == tclass)) {
1702 /* Use the role transition rule. */
1703 newcontext.role = roletr->new_role;
1704 break;
1705 }
1706 }
1707 }
1708
1709 /* Set the MLS attributes.
1710 This is done last because it may allocate memory. */
1711 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1712 &newcontext, sock);
1713 if (rc)
1714 goto out_unlock;
1715
1716 /* Check the validity of the context. */
1717 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1718 rc = compute_sid_handle_invalid_context(scontext,
1719 tcontext,
1720 tclass,
1721 &newcontext);
1722 if (rc)
1723 goto out_unlock;
1724 }
1725 /* Obtain the sid for the context. */
1726 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1727 out_unlock:
1728 read_unlock(&policy_rwlock);
1729 context_destroy(&newcontext);
1730 out:
1731 return rc;
1732 }
1733
1734 /**
1735 * security_transition_sid - Compute the SID for a new subject/object.
1736 * @ssid: source security identifier
1737 * @tsid: target security identifier
1738 * @tclass: target security class
1739 * @out_sid: security identifier for new subject/object
1740 *
1741 * Compute a SID to use for labeling a new subject or object in the
1742 * class @tclass based on a SID pair (@ssid, @tsid).
1743 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1744 * if insufficient memory is available, or %0 if the new SID was
1745 * computed successfully.
1746 */
1747 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1748 const struct qstr *qstr, u32 *out_sid)
1749 {
1750 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1751 qstr ? qstr->name : NULL, out_sid, true);
1752 }
1753
1754 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1755 const char *objname, u32 *out_sid)
1756 {
1757 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1758 objname, out_sid, false);
1759 }
1760
1761 /**
1762 * security_member_sid - Compute the SID for member selection.
1763 * @ssid: source security identifier
1764 * @tsid: target security identifier
1765 * @tclass: target security class
1766 * @out_sid: security identifier for selected member
1767 *
1768 * Compute a SID to use when selecting a member of a polyinstantiated
1769 * object of class @tclass based on a SID pair (@ssid, @tsid).
1770 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1771 * if insufficient memory is available, or %0 if the SID was
1772 * computed successfully.
1773 */
1774 int security_member_sid(u32 ssid,
1775 u32 tsid,
1776 u16 tclass,
1777 u32 *out_sid)
1778 {
1779 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1780 out_sid, false);
1781 }
1782
1783 /**
1784 * security_change_sid - Compute the SID for object relabeling.
1785 * @ssid: source security identifier
1786 * @tsid: target security identifier
1787 * @tclass: target security class
1788 * @out_sid: security identifier for selected member
1789 *
1790 * Compute a SID to use for relabeling an object of class @tclass
1791 * based on a SID pair (@ssid, @tsid).
1792 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1793 * if insufficient memory is available, or %0 if the SID was
1794 * computed successfully.
1795 */
1796 int security_change_sid(u32 ssid,
1797 u32 tsid,
1798 u16 tclass,
1799 u32 *out_sid)
1800 {
1801 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1802 out_sid, false);
1803 }
1804
1805 /* Clone the SID into the new SID table. */
1806 static int clone_sid(u32 sid,
1807 struct context *context,
1808 void *arg)
1809 {
1810 struct sidtab *s = arg;
1811
1812 if (sid > SECINITSID_NUM)
1813 return sidtab_insert(s, sid, context);
1814 else
1815 return 0;
1816 }
1817
1818 static inline int convert_context_handle_invalid_context(struct context *context)
1819 {
1820 char *s;
1821 u32 len;
1822
1823 if (selinux_enforcing)
1824 return -EINVAL;
1825
1826 if (!context_struct_to_string(context, &s, &len)) {
1827 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1828 kfree(s);
1829 }
1830 return 0;
1831 }
1832
1833 struct convert_context_args {
1834 struct policydb *oldp;
1835 struct policydb *newp;
1836 };
1837
1838 /*
1839 * Convert the values in the security context
1840 * structure `c' from the values specified
1841 * in the policy `p->oldp' to the values specified
1842 * in the policy `p->newp'. Verify that the
1843 * context is valid under the new policy.
1844 */
1845 static int convert_context(u32 key,
1846 struct context *c,
1847 void *p)
1848 {
1849 struct convert_context_args *args;
1850 struct context oldc;
1851 struct ocontext *oc;
1852 struct mls_range *range;
1853 struct role_datum *role;
1854 struct type_datum *typdatum;
1855 struct user_datum *usrdatum;
1856 char *s;
1857 u32 len;
1858 int rc = 0;
1859
1860 if (key <= SECINITSID_NUM)
1861 goto out;
1862
1863 args = p;
1864
1865 if (c->str) {
1866 struct context ctx;
1867
1868 rc = -ENOMEM;
1869 s = kstrdup(c->str, GFP_KERNEL);
1870 if (!s)
1871 goto out;
1872
1873 rc = string_to_context_struct(args->newp, NULL, s,
1874 c->len, &ctx, SECSID_NULL);
1875 kfree(s);
1876 if (!rc) {
1877 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1878 c->str);
1879 /* Replace string with mapped representation. */
1880 kfree(c->str);
1881 memcpy(c, &ctx, sizeof(*c));
1882 goto out;
1883 } else if (rc == -EINVAL) {
1884 /* Retain string representation for later mapping. */
1885 rc = 0;
1886 goto out;
1887 } else {
1888 /* Other error condition, e.g. ENOMEM. */
1889 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1890 c->str, -rc);
1891 goto out;
1892 }
1893 }
1894
1895 rc = context_cpy(&oldc, c);
1896 if (rc)
1897 goto out;
1898
1899 /* Convert the user. */
1900 rc = -EINVAL;
1901 usrdatum = hashtab_search(args->newp->p_users.table,
1902 sym_name(args->oldp, SYM_USERS, c->user - 1));
1903 if (!usrdatum)
1904 goto bad;
1905 c->user = usrdatum->value;
1906
1907 /* Convert the role. */
1908 rc = -EINVAL;
1909 role = hashtab_search(args->newp->p_roles.table,
1910 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1911 if (!role)
1912 goto bad;
1913 c->role = role->value;
1914
1915 /* Convert the type. */
1916 rc = -EINVAL;
1917 typdatum = hashtab_search(args->newp->p_types.table,
1918 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1919 if (!typdatum)
1920 goto bad;
1921 c->type = typdatum->value;
1922
1923 /* Convert the MLS fields if dealing with MLS policies */
1924 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1925 rc = mls_convert_context(args->oldp, args->newp, c);
1926 if (rc)
1927 goto bad;
1928 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1929 /*
1930 * Switching between MLS and non-MLS policy:
1931 * free any storage used by the MLS fields in the
1932 * context for all existing entries in the sidtab.
1933 */
1934 mls_context_destroy(c);
1935 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1936 /*
1937 * Switching between non-MLS and MLS policy:
1938 * ensure that the MLS fields of the context for all
1939 * existing entries in the sidtab are filled in with a
1940 * suitable default value, likely taken from one of the
1941 * initial SIDs.
1942 */
1943 oc = args->newp->ocontexts[OCON_ISID];
1944 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1945 oc = oc->next;
1946 rc = -EINVAL;
1947 if (!oc) {
1948 printk(KERN_ERR "SELinux: unable to look up"
1949 " the initial SIDs list\n");
1950 goto bad;
1951 }
1952 range = &oc->context[0].range;
1953 rc = mls_range_set(c, range);
1954 if (rc)
1955 goto bad;
1956 }
1957
1958 /* Check the validity of the new context. */
1959 if (!policydb_context_isvalid(args->newp, c)) {
1960 rc = convert_context_handle_invalid_context(&oldc);
1961 if (rc)
1962 goto bad;
1963 }
1964
1965 context_destroy(&oldc);
1966
1967 rc = 0;
1968 out:
1969 return rc;
1970 bad:
1971 /* Map old representation to string and save it. */
1972 rc = context_struct_to_string(&oldc, &s, &len);
1973 if (rc)
1974 return rc;
1975 context_destroy(&oldc);
1976 context_destroy(c);
1977 c->str = s;
1978 c->len = len;
1979 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1980 c->str);
1981 rc = 0;
1982 goto out;
1983 }
1984
1985 static void security_load_policycaps(void)
1986 {
1987 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1988 POLICYDB_CAPABILITY_NETPEER);
1989 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1990 POLICYDB_CAPABILITY_OPENPERM);
1991 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1992 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1993 }
1994
1995 static int security_preserve_bools(struct policydb *p);
1996
1997 /**
1998 * security_load_policy - Load a security policy configuration.
1999 * @data: binary policy data
2000 * @len: length of data in bytes
2001 *
2002 * Load a new set of security policy configuration data,
2003 * validate it and convert the SID table as necessary.
2004 * This function will flush the access vector cache after
2005 * loading the new policy.
2006 */
2007 int security_load_policy(void *data, size_t len)
2008 {
2009 struct policydb *oldpolicydb, *newpolicydb;
2010 struct sidtab oldsidtab, newsidtab;
2011 struct selinux_mapping *oldmap, *map = NULL;
2012 struct convert_context_args args;
2013 u32 seqno;
2014 u16 map_size;
2015 int rc = 0;
2016 struct policy_file file = { data, len }, *fp = &file;
2017
2018 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2019 if (!oldpolicydb) {
2020 rc = -ENOMEM;
2021 goto out;
2022 }
2023 newpolicydb = oldpolicydb + 1;
2024
2025 if (!ss_initialized) {
2026 avtab_cache_init();
2027 rc = policydb_read(&policydb, fp);
2028 if (rc) {
2029 avtab_cache_destroy();
2030 goto out;
2031 }
2032
2033 policydb.len = len;
2034 rc = selinux_set_mapping(&policydb, secclass_map,
2035 &current_mapping,
2036 &current_mapping_size);
2037 if (rc) {
2038 policydb_destroy(&policydb);
2039 avtab_cache_destroy();
2040 goto out;
2041 }
2042
2043 rc = policydb_load_isids(&policydb, &sidtab);
2044 if (rc) {
2045 policydb_destroy(&policydb);
2046 avtab_cache_destroy();
2047 goto out;
2048 }
2049
2050 security_load_policycaps();
2051 ss_initialized = 1;
2052 seqno = ++latest_granting;
2053 selinux_complete_init();
2054 avc_ss_reset(seqno);
2055 selnl_notify_policyload(seqno);
2056 selinux_status_update_policyload(seqno);
2057 selinux_netlbl_cache_invalidate();
2058 selinux_xfrm_notify_policyload();
2059 goto out;
2060 }
2061
2062 #if 0
2063 sidtab_hash_eval(&sidtab, "sids");
2064 #endif
2065
2066 rc = policydb_read(newpolicydb, fp);
2067 if (rc)
2068 goto out;
2069
2070 newpolicydb->len = len;
2071 /* If switching between different policy types, log MLS status */
2072 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2073 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2074 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2075 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2076
2077 rc = policydb_load_isids(newpolicydb, &newsidtab);
2078 if (rc) {
2079 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2080 policydb_destroy(newpolicydb);
2081 goto out;
2082 }
2083
2084 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2085 if (rc)
2086 goto err;
2087
2088 rc = security_preserve_bools(newpolicydb);
2089 if (rc) {
2090 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2091 goto err;
2092 }
2093
2094 /* Clone the SID table. */
2095 sidtab_shutdown(&sidtab);
2096
2097 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2098 if (rc)
2099 goto err;
2100
2101 /*
2102 * Convert the internal representations of contexts
2103 * in the new SID table.
2104 */
2105 args.oldp = &policydb;
2106 args.newp = newpolicydb;
2107 rc = sidtab_map(&newsidtab, convert_context, &args);
2108 if (rc) {
2109 printk(KERN_ERR "SELinux: unable to convert the internal"
2110 " representation of contexts in the new SID"
2111 " table\n");
2112 goto err;
2113 }
2114
2115 /* Save the old policydb and SID table to free later. */
2116 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2117 sidtab_set(&oldsidtab, &sidtab);
2118
2119 /* Install the new policydb and SID table. */
2120 write_lock_irq(&policy_rwlock);
2121 memcpy(&policydb, newpolicydb, sizeof(policydb));
2122 sidtab_set(&sidtab, &newsidtab);
2123 security_load_policycaps();
2124 oldmap = current_mapping;
2125 current_mapping = map;
2126 current_mapping_size = map_size;
2127 seqno = ++latest_granting;
2128 write_unlock_irq(&policy_rwlock);
2129
2130 /* Free the old policydb and SID table. */
2131 policydb_destroy(oldpolicydb);
2132 sidtab_destroy(&oldsidtab);
2133 kfree(oldmap);
2134
2135 avc_ss_reset(seqno);
2136 selnl_notify_policyload(seqno);
2137 selinux_status_update_policyload(seqno);
2138 selinux_netlbl_cache_invalidate();
2139 selinux_xfrm_notify_policyload();
2140
2141 rc = 0;
2142 goto out;
2143
2144 err:
2145 kfree(map);
2146 sidtab_destroy(&newsidtab);
2147 policydb_destroy(newpolicydb);
2148
2149 out:
2150 kfree(oldpolicydb);
2151 return rc;
2152 }
2153
2154 size_t security_policydb_len(void)
2155 {
2156 size_t len;
2157
2158 read_lock(&policy_rwlock);
2159 len = policydb.len;
2160 read_unlock(&policy_rwlock);
2161
2162 return len;
2163 }
2164
2165 /**
2166 * security_port_sid - Obtain the SID for a port.
2167 * @protocol: protocol number
2168 * @port: port number
2169 * @out_sid: security identifier
2170 */
2171 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2172 {
2173 struct ocontext *c;
2174 int rc = 0;
2175
2176 read_lock(&policy_rwlock);
2177
2178 c = policydb.ocontexts[OCON_PORT];
2179 while (c) {
2180 if (c->u.port.protocol == protocol &&
2181 c->u.port.low_port <= port &&
2182 c->u.port.high_port >= port)
2183 break;
2184 c = c->next;
2185 }
2186
2187 if (c) {
2188 if (!c->sid[0]) {
2189 rc = sidtab_context_to_sid(&sidtab,
2190 &c->context[0],
2191 &c->sid[0]);
2192 if (rc)
2193 goto out;
2194 }
2195 *out_sid = c->sid[0];
2196 } else {
2197 *out_sid = SECINITSID_PORT;
2198 }
2199
2200 out:
2201 read_unlock(&policy_rwlock);
2202 return rc;
2203 }
2204
2205 /**
2206 * security_netif_sid - Obtain the SID for a network interface.
2207 * @name: interface name
2208 * @if_sid: interface SID
2209 */
2210 int security_netif_sid(char *name, u32 *if_sid)
2211 {
2212 int rc = 0;
2213 struct ocontext *c;
2214
2215 read_lock(&policy_rwlock);
2216
2217 c = policydb.ocontexts[OCON_NETIF];
2218 while (c) {
2219 if (strcmp(name, c->u.name) == 0)
2220 break;
2221 c = c->next;
2222 }
2223
2224 if (c) {
2225 if (!c->sid[0] || !c->sid[1]) {
2226 rc = sidtab_context_to_sid(&sidtab,
2227 &c->context[0],
2228 &c->sid[0]);
2229 if (rc)
2230 goto out;
2231 rc = sidtab_context_to_sid(&sidtab,
2232 &c->context[1],
2233 &c->sid[1]);
2234 if (rc)
2235 goto out;
2236 }
2237 *if_sid = c->sid[0];
2238 } else
2239 *if_sid = SECINITSID_NETIF;
2240
2241 out:
2242 read_unlock(&policy_rwlock);
2243 return rc;
2244 }
2245
2246 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2247 {
2248 int i, fail = 0;
2249
2250 for (i = 0; i < 4; i++)
2251 if (addr[i] != (input[i] & mask[i])) {
2252 fail = 1;
2253 break;
2254 }
2255
2256 return !fail;
2257 }
2258
2259 /**
2260 * security_node_sid - Obtain the SID for a node (host).
2261 * @domain: communication domain aka address family
2262 * @addrp: address
2263 * @addrlen: address length in bytes
2264 * @out_sid: security identifier
2265 */
2266 int security_node_sid(u16 domain,
2267 void *addrp,
2268 u32 addrlen,
2269 u32 *out_sid)
2270 {
2271 int rc;
2272 struct ocontext *c;
2273
2274 read_lock(&policy_rwlock);
2275
2276 switch (domain) {
2277 case AF_INET: {
2278 u32 addr;
2279
2280 rc = -EINVAL;
2281 if (addrlen != sizeof(u32))
2282 goto out;
2283
2284 addr = *((u32 *)addrp);
2285
2286 c = policydb.ocontexts[OCON_NODE];
2287 while (c) {
2288 if (c->u.node.addr == (addr & c->u.node.mask))
2289 break;
2290 c = c->next;
2291 }
2292 break;
2293 }
2294
2295 case AF_INET6:
2296 rc = -EINVAL;
2297 if (addrlen != sizeof(u64) * 2)
2298 goto out;
2299 c = policydb.ocontexts[OCON_NODE6];
2300 while (c) {
2301 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2302 c->u.node6.mask))
2303 break;
2304 c = c->next;
2305 }
2306 break;
2307
2308 default:
2309 rc = 0;
2310 *out_sid = SECINITSID_NODE;
2311 goto out;
2312 }
2313
2314 if (c) {
2315 if (!c->sid[0]) {
2316 rc = sidtab_context_to_sid(&sidtab,
2317 &c->context[0],
2318 &c->sid[0]);
2319 if (rc)
2320 goto out;
2321 }
2322 *out_sid = c->sid[0];
2323 } else {
2324 *out_sid = SECINITSID_NODE;
2325 }
2326
2327 rc = 0;
2328 out:
2329 read_unlock(&policy_rwlock);
2330 return rc;
2331 }
2332
2333 #define SIDS_NEL 25
2334
2335 /**
2336 * security_get_user_sids - Obtain reachable SIDs for a user.
2337 * @fromsid: starting SID
2338 * @username: username
2339 * @sids: array of reachable SIDs for user
2340 * @nel: number of elements in @sids
2341 *
2342 * Generate the set of SIDs for legal security contexts
2343 * for a given user that can be reached by @fromsid.
2344 * Set *@sids to point to a dynamically allocated
2345 * array containing the set of SIDs. Set *@nel to the
2346 * number of elements in the array.
2347 */
2348
2349 int security_get_user_sids(u32 fromsid,
2350 char *username,
2351 u32 **sids,
2352 u32 *nel)
2353 {
2354 struct context *fromcon, usercon;
2355 u32 *mysids = NULL, *mysids2, sid;
2356 u32 mynel = 0, maxnel = SIDS_NEL;
2357 struct user_datum *user;
2358 struct role_datum *role;
2359 struct ebitmap_node *rnode, *tnode;
2360 int rc = 0, i, j;
2361
2362 *sids = NULL;
2363 *nel = 0;
2364
2365 if (!ss_initialized)
2366 goto out;
2367
2368 read_lock(&policy_rwlock);
2369
2370 context_init(&usercon);
2371
2372 rc = -EINVAL;
2373 fromcon = sidtab_search(&sidtab, fromsid);
2374 if (!fromcon)
2375 goto out_unlock;
2376
2377 rc = -EINVAL;
2378 user = hashtab_search(policydb.p_users.table, username);
2379 if (!user)
2380 goto out_unlock;
2381
2382 usercon.user = user->value;
2383
2384 rc = -ENOMEM;
2385 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2386 if (!mysids)
2387 goto out_unlock;
2388
2389 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2390 role = policydb.role_val_to_struct[i];
2391 usercon.role = i + 1;
2392 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2393 usercon.type = j + 1;
2394
2395 if (mls_setup_user_range(fromcon, user, &usercon))
2396 continue;
2397
2398 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2399 if (rc)
2400 goto out_unlock;
2401 if (mynel < maxnel) {
2402 mysids[mynel++] = sid;
2403 } else {
2404 rc = -ENOMEM;
2405 maxnel += SIDS_NEL;
2406 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2407 if (!mysids2)
2408 goto out_unlock;
2409 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2410 kfree(mysids);
2411 mysids = mysids2;
2412 mysids[mynel++] = sid;
2413 }
2414 }
2415 }
2416 rc = 0;
2417 out_unlock:
2418 read_unlock(&policy_rwlock);
2419 if (rc || !mynel) {
2420 kfree(mysids);
2421 goto out;
2422 }
2423
2424 rc = -ENOMEM;
2425 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2426 if (!mysids2) {
2427 kfree(mysids);
2428 goto out;
2429 }
2430 for (i = 0, j = 0; i < mynel; i++) {
2431 struct av_decision dummy_avd;
2432 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2433 SECCLASS_PROCESS, /* kernel value */
2434 PROCESS__TRANSITION, AVC_STRICT,
2435 &dummy_avd);
2436 if (!rc)
2437 mysids2[j++] = mysids[i];
2438 cond_resched();
2439 }
2440 rc = 0;
2441 kfree(mysids);
2442 *sids = mysids2;
2443 *nel = j;
2444 out:
2445 return rc;
2446 }
2447
2448 /**
2449 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2450 * @fstype: filesystem type
2451 * @path: path from root of mount
2452 * @sclass: file security class
2453 * @sid: SID for path
2454 *
2455 * Obtain a SID to use for a file in a filesystem that
2456 * cannot support xattr or use a fixed labeling behavior like
2457 * transition SIDs or task SIDs.
2458 *
2459 * The caller must acquire the policy_rwlock before calling this function.
2460 */
2461 static inline int __security_genfs_sid(const char *fstype,
2462 char *path,
2463 u16 orig_sclass,
2464 u32 *sid)
2465 {
2466 int len;
2467 u16 sclass;
2468 struct genfs *genfs;
2469 struct ocontext *c;
2470 int rc, cmp = 0;
2471
2472 while (path[0] == '/' && path[1] == '/')
2473 path++;
2474
2475 sclass = unmap_class(orig_sclass);
2476 *sid = SECINITSID_UNLABELED;
2477
2478 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2479 cmp = strcmp(fstype, genfs->fstype);
2480 if (cmp <= 0)
2481 break;
2482 }
2483
2484 rc = -ENOENT;
2485 if (!genfs || cmp)
2486 goto out;
2487
2488 for (c = genfs->head; c; c = c->next) {
2489 len = strlen(c->u.name);
2490 if ((!c->v.sclass || sclass == c->v.sclass) &&
2491 (strncmp(c->u.name, path, len) == 0))
2492 break;
2493 }
2494
2495 rc = -ENOENT;
2496 if (!c)
2497 goto out;
2498
2499 if (!c->sid[0]) {
2500 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2501 if (rc)
2502 goto out;
2503 }
2504
2505 *sid = c->sid[0];
2506 rc = 0;
2507 out:
2508 return rc;
2509 }
2510
2511 /**
2512 * security_genfs_sid - Obtain a SID for a file in a filesystem
2513 * @fstype: filesystem type
2514 * @path: path from root of mount
2515 * @sclass: file security class
2516 * @sid: SID for path
2517 *
2518 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2519 * it afterward.
2520 */
2521 int security_genfs_sid(const char *fstype,
2522 char *path,
2523 u16 orig_sclass,
2524 u32 *sid)
2525 {
2526 int retval;
2527
2528 read_lock(&policy_rwlock);
2529 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2530 read_unlock(&policy_rwlock);
2531 return retval;
2532 }
2533
2534 /**
2535 * security_fs_use - Determine how to handle labeling for a filesystem.
2536 * @sb: superblock in question
2537 */
2538 int security_fs_use(struct super_block *sb)
2539 {
2540 int rc = 0;
2541 struct ocontext *c;
2542 struct superblock_security_struct *sbsec = sb->s_security;
2543 const char *fstype = sb->s_type->name;
2544
2545 read_lock(&policy_rwlock);
2546
2547 c = policydb.ocontexts[OCON_FSUSE];
2548 while (c) {
2549 if (strcmp(fstype, c->u.name) == 0)
2550 break;
2551 c = c->next;
2552 }
2553
2554 if (c) {
2555 sbsec->behavior = c->v.behavior;
2556 if (!c->sid[0]) {
2557 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2558 &c->sid[0]);
2559 if (rc)
2560 goto out;
2561 }
2562 sbsec->sid = c->sid[0];
2563 } else {
2564 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2565 &sbsec->sid);
2566 if (rc) {
2567 sbsec->behavior = SECURITY_FS_USE_NONE;
2568 rc = 0;
2569 } else {
2570 sbsec->behavior = SECURITY_FS_USE_GENFS;
2571 }
2572 }
2573
2574 out:
2575 read_unlock(&policy_rwlock);
2576 return rc;
2577 }
2578
2579 int security_get_bools(int *len, char ***names, int **values)
2580 {
2581 int i, rc;
2582
2583 read_lock(&policy_rwlock);
2584 *names = NULL;
2585 *values = NULL;
2586
2587 rc = 0;
2588 *len = policydb.p_bools.nprim;
2589 if (!*len)
2590 goto out;
2591
2592 rc = -ENOMEM;
2593 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2594 if (!*names)
2595 goto err;
2596
2597 rc = -ENOMEM;
2598 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2599 if (!*values)
2600 goto err;
2601
2602 for (i = 0; i < *len; i++) {
2603 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2604
2605 rc = -ENOMEM;
2606 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2607 if (!(*names)[i])
2608 goto err;
2609 }
2610 rc = 0;
2611 out:
2612 read_unlock(&policy_rwlock);
2613 return rc;
2614 err:
2615 if (*names) {
2616 for (i = 0; i < *len; i++)
2617 kfree((*names)[i]);
2618 }
2619 kfree(*values);
2620 goto out;
2621 }
2622
2623
2624 int security_set_bools(int len, int *values)
2625 {
2626 int i, rc;
2627 int lenp, seqno = 0;
2628 struct cond_node *cur;
2629
2630 write_lock_irq(&policy_rwlock);
2631
2632 rc = -EFAULT;
2633 lenp = policydb.p_bools.nprim;
2634 if (len != lenp)
2635 goto out;
2636
2637 for (i = 0; i < len; i++) {
2638 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2639 audit_log(current->audit_context, GFP_ATOMIC,
2640 AUDIT_MAC_CONFIG_CHANGE,
2641 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2642 sym_name(&policydb, SYM_BOOLS, i),
2643 !!values[i],
2644 policydb.bool_val_to_struct[i]->state,
2645 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2646 audit_get_sessionid(current));
2647 }
2648 if (values[i])
2649 policydb.bool_val_to_struct[i]->state = 1;
2650 else
2651 policydb.bool_val_to_struct[i]->state = 0;
2652 }
2653
2654 for (cur = policydb.cond_list; cur; cur = cur->next) {
2655 rc = evaluate_cond_node(&policydb, cur);
2656 if (rc)
2657 goto out;
2658 }
2659
2660 seqno = ++latest_granting;
2661 rc = 0;
2662 out:
2663 write_unlock_irq(&policy_rwlock);
2664 if (!rc) {
2665 avc_ss_reset(seqno);
2666 selnl_notify_policyload(seqno);
2667 selinux_status_update_policyload(seqno);
2668 selinux_xfrm_notify_policyload();
2669 }
2670 return rc;
2671 }
2672
2673 int security_get_bool_value(int index)
2674 {
2675 int rc;
2676 int len;
2677
2678 read_lock(&policy_rwlock);
2679
2680 rc = -EFAULT;
2681 len = policydb.p_bools.nprim;
2682 if (index >= len)
2683 goto out;
2684
2685 rc = policydb.bool_val_to_struct[index]->state;
2686 out:
2687 read_unlock(&policy_rwlock);
2688 return rc;
2689 }
2690
2691 static int security_preserve_bools(struct policydb *p)
2692 {
2693 int rc, nbools = 0, *bvalues = NULL, i;
2694 char **bnames = NULL;
2695 struct cond_bool_datum *booldatum;
2696 struct cond_node *cur;
2697
2698 rc = security_get_bools(&nbools, &bnames, &bvalues);
2699 if (rc)
2700 goto out;
2701 for (i = 0; i < nbools; i++) {
2702 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2703 if (booldatum)
2704 booldatum->state = bvalues[i];
2705 }
2706 for (cur = p->cond_list; cur; cur = cur->next) {
2707 rc = evaluate_cond_node(p, cur);
2708 if (rc)
2709 goto out;
2710 }
2711
2712 out:
2713 if (bnames) {
2714 for (i = 0; i < nbools; i++)
2715 kfree(bnames[i]);
2716 }
2717 kfree(bnames);
2718 kfree(bvalues);
2719 return rc;
2720 }
2721
2722 /*
2723 * security_sid_mls_copy() - computes a new sid based on the given
2724 * sid and the mls portion of mls_sid.
2725 */
2726 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2727 {
2728 struct context *context1;
2729 struct context *context2;
2730 struct context newcon;
2731 char *s;
2732 u32 len;
2733 int rc;
2734
2735 rc = 0;
2736 if (!ss_initialized || !policydb.mls_enabled) {
2737 *new_sid = sid;
2738 goto out;
2739 }
2740
2741 context_init(&newcon);
2742
2743 read_lock(&policy_rwlock);
2744
2745 rc = -EINVAL;
2746 context1 = sidtab_search(&sidtab, sid);
2747 if (!context1) {
2748 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2749 __func__, sid);
2750 goto out_unlock;
2751 }
2752
2753 rc = -EINVAL;
2754 context2 = sidtab_search(&sidtab, mls_sid);
2755 if (!context2) {
2756 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2757 __func__, mls_sid);
2758 goto out_unlock;
2759 }
2760
2761 newcon.user = context1->user;
2762 newcon.role = context1->role;
2763 newcon.type = context1->type;
2764 rc = mls_context_cpy(&newcon, context2);
2765 if (rc)
2766 goto out_unlock;
2767
2768 /* Check the validity of the new context. */
2769 if (!policydb_context_isvalid(&policydb, &newcon)) {
2770 rc = convert_context_handle_invalid_context(&newcon);
2771 if (rc) {
2772 if (!context_struct_to_string(&newcon, &s, &len)) {
2773 audit_log(current->audit_context,
2774 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2775 "op=security_sid_mls_copy "
2776 "invalid_context=%s", s);
2777 kfree(s);
2778 }
2779 goto out_unlock;
2780 }
2781 }
2782
2783 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2784 out_unlock:
2785 read_unlock(&policy_rwlock);
2786 context_destroy(&newcon);
2787 out:
2788 return rc;
2789 }
2790
2791 /**
2792 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2793 * @nlbl_sid: NetLabel SID
2794 * @nlbl_type: NetLabel labeling protocol type
2795 * @xfrm_sid: XFRM SID
2796 *
2797 * Description:
2798 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2799 * resolved into a single SID it is returned via @peer_sid and the function
2800 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2801 * returns a negative value. A table summarizing the behavior is below:
2802 *
2803 * | function return | @sid
2804 * ------------------------------+-----------------+-----------------
2805 * no peer labels | 0 | SECSID_NULL
2806 * single peer label | 0 | <peer_label>
2807 * multiple, consistent labels | 0 | <peer_label>
2808 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2809 *
2810 */
2811 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2812 u32 xfrm_sid,
2813 u32 *peer_sid)
2814 {
2815 int rc;
2816 struct context *nlbl_ctx;
2817 struct context *xfrm_ctx;
2818
2819 *peer_sid = SECSID_NULL;
2820
2821 /* handle the common (which also happens to be the set of easy) cases
2822 * right away, these two if statements catch everything involving a
2823 * single or absent peer SID/label */
2824 if (xfrm_sid == SECSID_NULL) {
2825 *peer_sid = nlbl_sid;
2826 return 0;
2827 }
2828 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2829 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2830 * is present */
2831 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2832 *peer_sid = xfrm_sid;
2833 return 0;
2834 }
2835
2836 /* we don't need to check ss_initialized here since the only way both
2837 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2838 * security server was initialized and ss_initialized was true */
2839 if (!policydb.mls_enabled)
2840 return 0;
2841
2842 read_lock(&policy_rwlock);
2843
2844 rc = -EINVAL;
2845 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2846 if (!nlbl_ctx) {
2847 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2848 __func__, nlbl_sid);
2849 goto out;
2850 }
2851 rc = -EINVAL;
2852 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2853 if (!xfrm_ctx) {
2854 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2855 __func__, xfrm_sid);
2856 goto out;
2857 }
2858 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2859 if (rc)
2860 goto out;
2861
2862 /* at present NetLabel SIDs/labels really only carry MLS
2863 * information so if the MLS portion of the NetLabel SID
2864 * matches the MLS portion of the labeled XFRM SID/label
2865 * then pass along the XFRM SID as it is the most
2866 * expressive */
2867 *peer_sid = xfrm_sid;
2868 out:
2869 read_unlock(&policy_rwlock);
2870 return rc;
2871 }
2872
2873 static int get_classes_callback(void *k, void *d, void *args)
2874 {
2875 struct class_datum *datum = d;
2876 char *name = k, **classes = args;
2877 int value = datum->value - 1;
2878
2879 classes[value] = kstrdup(name, GFP_ATOMIC);
2880 if (!classes[value])
2881 return -ENOMEM;
2882
2883 return 0;
2884 }
2885
2886 int security_get_classes(char ***classes, int *nclasses)
2887 {
2888 int rc;
2889
2890 read_lock(&policy_rwlock);
2891
2892 rc = -ENOMEM;
2893 *nclasses = policydb.p_classes.nprim;
2894 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2895 if (!*classes)
2896 goto out;
2897
2898 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2899 *classes);
2900 if (rc) {
2901 int i;
2902 for (i = 0; i < *nclasses; i++)
2903 kfree((*classes)[i]);
2904 kfree(*classes);
2905 }
2906
2907 out:
2908 read_unlock(&policy_rwlock);
2909 return rc;
2910 }
2911
2912 static int get_permissions_callback(void *k, void *d, void *args)
2913 {
2914 struct perm_datum *datum = d;
2915 char *name = k, **perms = args;
2916 int value = datum->value - 1;
2917
2918 perms[value] = kstrdup(name, GFP_ATOMIC);
2919 if (!perms[value])
2920 return -ENOMEM;
2921
2922 return 0;
2923 }
2924
2925 int security_get_permissions(char *class, char ***perms, int *nperms)
2926 {
2927 int rc, i;
2928 struct class_datum *match;
2929
2930 read_lock(&policy_rwlock);
2931
2932 rc = -EINVAL;
2933 match = hashtab_search(policydb.p_classes.table, class);
2934 if (!match) {
2935 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2936 __func__, class);
2937 goto out;
2938 }
2939
2940 rc = -ENOMEM;
2941 *nperms = match->permissions.nprim;
2942 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2943 if (!*perms)
2944 goto out;
2945
2946 if (match->comdatum) {
2947 rc = hashtab_map(match->comdatum->permissions.table,
2948 get_permissions_callback, *perms);
2949 if (rc)
2950 goto err;
2951 }
2952
2953 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2954 *perms);
2955 if (rc)
2956 goto err;
2957
2958 out:
2959 read_unlock(&policy_rwlock);
2960 return rc;
2961
2962 err:
2963 read_unlock(&policy_rwlock);
2964 for (i = 0; i < *nperms; i++)
2965 kfree((*perms)[i]);
2966 kfree(*perms);
2967 return rc;
2968 }
2969
2970 int security_get_reject_unknown(void)
2971 {
2972 return policydb.reject_unknown;
2973 }
2974
2975 int security_get_allow_unknown(void)
2976 {
2977 return policydb.allow_unknown;
2978 }
2979
2980 /**
2981 * security_policycap_supported - Check for a specific policy capability
2982 * @req_cap: capability
2983 *
2984 * Description:
2985 * This function queries the currently loaded policy to see if it supports the
2986 * capability specified by @req_cap. Returns true (1) if the capability is
2987 * supported, false (0) if it isn't supported.
2988 *
2989 */
2990 int security_policycap_supported(unsigned int req_cap)
2991 {
2992 int rc;
2993
2994 read_lock(&policy_rwlock);
2995 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2996 read_unlock(&policy_rwlock);
2997
2998 return rc;
2999 }
3000
3001 struct selinux_audit_rule {
3002 u32 au_seqno;
3003 struct context au_ctxt;
3004 };
3005
3006 void selinux_audit_rule_free(void *vrule)
3007 {
3008 struct selinux_audit_rule *rule = vrule;
3009
3010 if (rule) {
3011 context_destroy(&rule->au_ctxt);
3012 kfree(rule);
3013 }
3014 }
3015
3016 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3017 {
3018 struct selinux_audit_rule *tmprule;
3019 struct role_datum *roledatum;
3020 struct type_datum *typedatum;
3021 struct user_datum *userdatum;
3022 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3023 int rc = 0;
3024
3025 *rule = NULL;
3026
3027 if (!ss_initialized)
3028 return -EOPNOTSUPP;
3029
3030 switch (field) {
3031 case AUDIT_SUBJ_USER:
3032 case AUDIT_SUBJ_ROLE:
3033 case AUDIT_SUBJ_TYPE:
3034 case AUDIT_OBJ_USER:
3035 case AUDIT_OBJ_ROLE:
3036 case AUDIT_OBJ_TYPE:
3037 /* only 'equals' and 'not equals' fit user, role, and type */
3038 if (op != Audit_equal && op != Audit_not_equal)
3039 return -EINVAL;
3040 break;
3041 case AUDIT_SUBJ_SEN:
3042 case AUDIT_SUBJ_CLR:
3043 case AUDIT_OBJ_LEV_LOW:
3044 case AUDIT_OBJ_LEV_HIGH:
3045 /* we do not allow a range, indicated by the presence of '-' */
3046 if (strchr(rulestr, '-'))
3047 return -EINVAL;
3048 break;
3049 default:
3050 /* only the above fields are valid */
3051 return -EINVAL;
3052 }
3053
3054 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3055 if (!tmprule)
3056 return -ENOMEM;
3057
3058 context_init(&tmprule->au_ctxt);
3059
3060 read_lock(&policy_rwlock);
3061
3062 tmprule->au_seqno = latest_granting;
3063
3064 switch (field) {
3065 case AUDIT_SUBJ_USER:
3066 case AUDIT_OBJ_USER:
3067 rc = -EINVAL;
3068 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3069 if (!userdatum)
3070 goto out;
3071 tmprule->au_ctxt.user = userdatum->value;
3072 break;
3073 case AUDIT_SUBJ_ROLE:
3074 case AUDIT_OBJ_ROLE:
3075 rc = -EINVAL;
3076 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3077 if (!roledatum)
3078 goto out;
3079 tmprule->au_ctxt.role = roledatum->value;
3080 break;
3081 case AUDIT_SUBJ_TYPE:
3082 case AUDIT_OBJ_TYPE:
3083 rc = -EINVAL;
3084 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3085 if (!typedatum)
3086 goto out;
3087 tmprule->au_ctxt.type = typedatum->value;
3088 break;
3089 case AUDIT_SUBJ_SEN:
3090 case AUDIT_SUBJ_CLR:
3091 case AUDIT_OBJ_LEV_LOW:
3092 case AUDIT_OBJ_LEV_HIGH:
3093 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3094 if (rc)
3095 goto out;
3096 break;
3097 }
3098 rc = 0;
3099 out:
3100 read_unlock(&policy_rwlock);
3101
3102 if (rc) {
3103 selinux_audit_rule_free(tmprule);
3104 tmprule = NULL;
3105 }
3106
3107 *rule = tmprule;
3108
3109 return rc;
3110 }
3111
3112 /* Check to see if the rule contains any selinux fields */
3113 int selinux_audit_rule_known(struct audit_krule *rule)
3114 {
3115 int i;
3116
3117 for (i = 0; i < rule->field_count; i++) {
3118 struct audit_field *f = &rule->fields[i];
3119 switch (f->type) {
3120 case AUDIT_SUBJ_USER:
3121 case AUDIT_SUBJ_ROLE:
3122 case AUDIT_SUBJ_TYPE:
3123 case AUDIT_SUBJ_SEN:
3124 case AUDIT_SUBJ_CLR:
3125 case AUDIT_OBJ_USER:
3126 case AUDIT_OBJ_ROLE:
3127 case AUDIT_OBJ_TYPE:
3128 case AUDIT_OBJ_LEV_LOW:
3129 case AUDIT_OBJ_LEV_HIGH:
3130 return 1;
3131 }
3132 }
3133
3134 return 0;
3135 }
3136
3137 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3138 struct audit_context *actx)
3139 {
3140 struct context *ctxt;
3141 struct mls_level *level;
3142 struct selinux_audit_rule *rule = vrule;
3143 int match = 0;
3144
3145 if (unlikely(!rule)) {
3146 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3147 return -ENOENT;
3148 }
3149
3150 read_lock(&policy_rwlock);
3151
3152 if (rule->au_seqno < latest_granting) {
3153 match = -ESTALE;
3154 goto out;
3155 }
3156
3157 ctxt = sidtab_search(&sidtab, sid);
3158 if (unlikely(!ctxt)) {
3159 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3160 sid);
3161 match = -ENOENT;
3162 goto out;
3163 }
3164
3165 /* a field/op pair that is not caught here will simply fall through
3166 without a match */
3167 switch (field) {
3168 case AUDIT_SUBJ_USER:
3169 case AUDIT_OBJ_USER:
3170 switch (op) {
3171 case Audit_equal:
3172 match = (ctxt->user == rule->au_ctxt.user);
3173 break;
3174 case Audit_not_equal:
3175 match = (ctxt->user != rule->au_ctxt.user);
3176 break;
3177 }
3178 break;
3179 case AUDIT_SUBJ_ROLE:
3180 case AUDIT_OBJ_ROLE:
3181 switch (op) {
3182 case Audit_equal:
3183 match = (ctxt->role == rule->au_ctxt.role);
3184 break;
3185 case Audit_not_equal:
3186 match = (ctxt->role != rule->au_ctxt.role);
3187 break;
3188 }
3189 break;
3190 case AUDIT_SUBJ_TYPE:
3191 case AUDIT_OBJ_TYPE:
3192 switch (op) {
3193 case Audit_equal:
3194 match = (ctxt->type == rule->au_ctxt.type);
3195 break;
3196 case Audit_not_equal:
3197 match = (ctxt->type != rule->au_ctxt.type);
3198 break;
3199 }
3200 break;
3201 case AUDIT_SUBJ_SEN:
3202 case AUDIT_SUBJ_CLR:
3203 case AUDIT_OBJ_LEV_LOW:
3204 case AUDIT_OBJ_LEV_HIGH:
3205 level = ((field == AUDIT_SUBJ_SEN ||
3206 field == AUDIT_OBJ_LEV_LOW) ?
3207 &ctxt->range.level[0] : &ctxt->range.level[1]);
3208 switch (op) {
3209 case Audit_equal:
3210 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3211 level);
3212 break;
3213 case Audit_not_equal:
3214 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3215 level);
3216 break;
3217 case Audit_lt:
3218 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3219 level) &&
3220 !mls_level_eq(&rule->au_ctxt.range.level[0],
3221 level));
3222 break;
3223 case Audit_le:
3224 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3225 level);
3226 break;
3227 case Audit_gt:
3228 match = (mls_level_dom(level,
3229 &rule->au_ctxt.range.level[0]) &&
3230 !mls_level_eq(level,
3231 &rule->au_ctxt.range.level[0]));
3232 break;
3233 case Audit_ge:
3234 match = mls_level_dom(level,
3235 &rule->au_ctxt.range.level[0]);
3236 break;
3237 }
3238 }
3239
3240 out:
3241 read_unlock(&policy_rwlock);
3242 return match;
3243 }
3244
3245 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3246
3247 static int aurule_avc_callback(u32 event)
3248 {
3249 int err = 0;
3250
3251 if (event == AVC_CALLBACK_RESET && aurule_callback)
3252 err = aurule_callback();
3253 return err;
3254 }
3255
3256 static int __init aurule_init(void)
3257 {
3258 int err;
3259
3260 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3261 if (err)
3262 panic("avc_add_callback() failed, error %d\n", err);
3263
3264 return err;
3265 }
3266 __initcall(aurule_init);
3267
3268 #ifdef CONFIG_NETLABEL
3269 /**
3270 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3271 * @secattr: the NetLabel packet security attributes
3272 * @sid: the SELinux SID
3273 *
3274 * Description:
3275 * Attempt to cache the context in @ctx, which was derived from the packet in
3276 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3277 * already been initialized.
3278 *
3279 */
3280 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3281 u32 sid)
3282 {
3283 u32 *sid_cache;
3284
3285 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3286 if (sid_cache == NULL)
3287 return;
3288 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3289 if (secattr->cache == NULL) {
3290 kfree(sid_cache);
3291 return;
3292 }
3293
3294 *sid_cache = sid;
3295 secattr->cache->free = kfree;
3296 secattr->cache->data = sid_cache;
3297 secattr->flags |= NETLBL_SECATTR_CACHE;
3298 }
3299
3300 /**
3301 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3302 * @secattr: the NetLabel packet security attributes
3303 * @sid: the SELinux SID
3304 *
3305 * Description:
3306 * Convert the given NetLabel security attributes in @secattr into a
3307 * SELinux SID. If the @secattr field does not contain a full SELinux
3308 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3309 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3310 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3311 * conversion for future lookups. Returns zero on success, negative values on
3312 * failure.
3313 *
3314 */
3315 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3316 u32 *sid)
3317 {
3318 int rc;
3319 struct context *ctx;
3320 struct context ctx_new;
3321
3322 if (!ss_initialized) {
3323 *sid = SECSID_NULL;
3324 return 0;
3325 }
3326
3327 read_lock(&policy_rwlock);
3328
3329 if (secattr->flags & NETLBL_SECATTR_CACHE)
3330 *sid = *(u32 *)secattr->cache->data;
3331 else if (secattr->flags & NETLBL_SECATTR_SECID)
3332 *sid = secattr->attr.secid;
3333 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3334 rc = -EIDRM;
3335 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3336 if (ctx == NULL)
3337 goto out;
3338
3339 context_init(&ctx_new);
3340 ctx_new.user = ctx->user;
3341 ctx_new.role = ctx->role;
3342 ctx_new.type = ctx->type;
3343 mls_import_netlbl_lvl(&ctx_new, secattr);
3344 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3345 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3346 if (rc)
3347 goto out;
3348 }
3349 rc = -EIDRM;
3350 if (!mls_context_isvalid(&policydb, &ctx_new))
3351 goto out_free;
3352
3353 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3354 if (rc)
3355 goto out_free;
3356
3357 security_netlbl_cache_add(secattr, *sid);
3358
3359 ebitmap_destroy(&ctx_new.range.level[0].cat);
3360 } else
3361 *sid = SECSID_NULL;
3362
3363 read_unlock(&policy_rwlock);
3364 return 0;
3365 out_free:
3366 ebitmap_destroy(&ctx_new.range.level[0].cat);
3367 out:
3368 read_unlock(&policy_rwlock);
3369 return rc;
3370 }
3371
3372 /**
3373 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3374 * @sid: the SELinux SID
3375 * @secattr: the NetLabel packet security attributes
3376 *
3377 * Description:
3378 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3379 * Returns zero on success, negative values on failure.
3380 *
3381 */
3382 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3383 {
3384 int rc;
3385 struct context *ctx;
3386
3387 if (!ss_initialized)
3388 return 0;
3389
3390 read_lock(&policy_rwlock);
3391
3392 rc = -ENOENT;
3393 ctx = sidtab_search(&sidtab, sid);
3394 if (ctx == NULL)
3395 goto out;
3396
3397 rc = -ENOMEM;
3398 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3399 GFP_ATOMIC);
3400 if (secattr->domain == NULL)
3401 goto out;
3402
3403 secattr->attr.secid = sid;
3404 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3405 mls_export_netlbl_lvl(ctx, secattr);
3406 rc = mls_export_netlbl_cat(ctx, secattr);
3407 out:
3408 read_unlock(&policy_rwlock);
3409 return rc;
3410 }
3411 #endif /* CONFIG_NETLABEL */
3412
3413 /**
3414 * security_read_policy - read the policy.
3415 * @data: binary policy data
3416 * @len: length of data in bytes
3417 *
3418 */
3419 int security_read_policy(void **data, size_t *len)
3420 {
3421 int rc;
3422 struct policy_file fp;
3423
3424 if (!ss_initialized)
3425 return -EINVAL;
3426
3427 *len = security_policydb_len();
3428
3429 *data = vmalloc_user(*len);
3430 if (!*data)
3431 return -ENOMEM;
3432
3433 fp.data = *data;
3434 fp.len = *len;
3435
3436 read_lock(&policy_rwlock);
3437 rc = policydb_write(&policydb, &fp);
3438 read_unlock(&policy_rwlock);
3439
3440 if (rc)
3441 return rc;
3442
3443 *len = (unsigned long)fp.data - (unsigned long)*data;
3444 return 0;
3445
3446 }
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