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