]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - security/selinux/ss/services.c
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'v3.13' into for-3.15
[mirror_ubuntu-artful-kernel.git] / security / selinux / ss / services.c
1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76
77 static DEFINE_RWLOCK(policy_rwlock);
78
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82
83 /*
84 * The largest sequence number that has been used when
85 * providing an access decision to the access vector cache.
86 * The sequence number only changes when a policy change
87 * occurs.
88 */
89 static u32 latest_granting;
90
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 u32 *scontext_len);
94
95 static void context_struct_compute_av(struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd);
99
100 struct selinux_mapping {
101 u16 value; /* policy value */
102 unsigned num_perms;
103 u32 perms[sizeof(u32) * 8];
104 };
105
106 static struct selinux_mapping *current_mapping;
107 static u16 current_mapping_size;
108
109 static int selinux_set_mapping(struct policydb *pol,
110 struct security_class_mapping *map,
111 struct selinux_mapping **out_map_p,
112 u16 *out_map_size)
113 {
114 struct selinux_mapping *out_map = NULL;
115 size_t size = sizeof(struct selinux_mapping);
116 u16 i, j;
117 unsigned k;
118 bool print_unknown_handle = false;
119
120 /* Find number of classes in the input mapping */
121 if (!map)
122 return -EINVAL;
123 i = 0;
124 while (map[i].name)
125 i++;
126
127 /* Allocate space for the class records, plus one for class zero */
128 out_map = kcalloc(++i, size, GFP_ATOMIC);
129 if (!out_map)
130 return -ENOMEM;
131
132 /* Store the raw class and permission values */
133 j = 0;
134 while (map[j].name) {
135 struct security_class_mapping *p_in = map + (j++);
136 struct selinux_mapping *p_out = out_map + j;
137
138 /* An empty class string skips ahead */
139 if (!strcmp(p_in->name, "")) {
140 p_out->num_perms = 0;
141 continue;
142 }
143
144 p_out->value = string_to_security_class(pol, p_in->name);
145 if (!p_out->value) {
146 printk(KERN_INFO
147 "SELinux: Class %s not defined in policy.\n",
148 p_in->name);
149 if (pol->reject_unknown)
150 goto err;
151 p_out->num_perms = 0;
152 print_unknown_handle = true;
153 continue;
154 }
155
156 k = 0;
157 while (p_in->perms && p_in->perms[k]) {
158 /* An empty permission string skips ahead */
159 if (!*p_in->perms[k]) {
160 k++;
161 continue;
162 }
163 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
164 p_in->perms[k]);
165 if (!p_out->perms[k]) {
166 printk(KERN_INFO
167 "SELinux: Permission %s in class %s not defined in policy.\n",
168 p_in->perms[k], p_in->name);
169 if (pol->reject_unknown)
170 goto err;
171 print_unknown_handle = true;
172 }
173
174 k++;
175 }
176 p_out->num_perms = k;
177 }
178
179 if (print_unknown_handle)
180 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
181 pol->allow_unknown ? "allowed" : "denied");
182
183 *out_map_p = out_map;
184 *out_map_size = i;
185 return 0;
186 err:
187 kfree(out_map);
188 return -EINVAL;
189 }
190
191 /*
192 * Get real, policy values from mapped values
193 */
194
195 static u16 unmap_class(u16 tclass)
196 {
197 if (tclass < current_mapping_size)
198 return current_mapping[tclass].value;
199
200 return tclass;
201 }
202
203 /*
204 * Get kernel value for class from its policy value
205 */
206 static u16 map_class(u16 pol_value)
207 {
208 u16 i;
209
210 for (i = 1; i < current_mapping_size; i++) {
211 if (current_mapping[i].value == pol_value)
212 return i;
213 }
214
215 return SECCLASS_NULL;
216 }
217
218 static void map_decision(u16 tclass, struct av_decision *avd,
219 int allow_unknown)
220 {
221 if (tclass < current_mapping_size) {
222 unsigned i, n = current_mapping[tclass].num_perms;
223 u32 result;
224
225 for (i = 0, result = 0; i < n; i++) {
226 if (avd->allowed & current_mapping[tclass].perms[i])
227 result |= 1<<i;
228 if (allow_unknown && !current_mapping[tclass].perms[i])
229 result |= 1<<i;
230 }
231 avd->allowed = result;
232
233 for (i = 0, result = 0; i < n; i++)
234 if (avd->auditallow & current_mapping[tclass].perms[i])
235 result |= 1<<i;
236 avd->auditallow = result;
237
238 for (i = 0, result = 0; i < n; i++) {
239 if (avd->auditdeny & current_mapping[tclass].perms[i])
240 result |= 1<<i;
241 if (!allow_unknown && !current_mapping[tclass].perms[i])
242 result |= 1<<i;
243 }
244 /*
245 * In case the kernel has a bug and requests a permission
246 * between num_perms and the maximum permission number, we
247 * should audit that denial
248 */
249 for (; i < (sizeof(u32)*8); i++)
250 result |= 1<<i;
251 avd->auditdeny = result;
252 }
253 }
254
255 int security_mls_enabled(void)
256 {
257 return policydb.mls_enabled;
258 }
259
260 /*
261 * Return the boolean value of a constraint expression
262 * when it is applied to the specified source and target
263 * security contexts.
264 *
265 * xcontext is a special beast... It is used by the validatetrans rules
266 * only. For these rules, scontext is the context before the transition,
267 * tcontext is the context after the transition, and xcontext is the context
268 * of the process performing the transition. All other callers of
269 * constraint_expr_eval should pass in NULL for xcontext.
270 */
271 static int constraint_expr_eval(struct context *scontext,
272 struct context *tcontext,
273 struct context *xcontext,
274 struct constraint_expr *cexpr)
275 {
276 u32 val1, val2;
277 struct context *c;
278 struct role_datum *r1, *r2;
279 struct mls_level *l1, *l2;
280 struct constraint_expr *e;
281 int s[CEXPR_MAXDEPTH];
282 int sp = -1;
283
284 for (e = cexpr; e; e = e->next) {
285 switch (e->expr_type) {
286 case CEXPR_NOT:
287 BUG_ON(sp < 0);
288 s[sp] = !s[sp];
289 break;
290 case CEXPR_AND:
291 BUG_ON(sp < 1);
292 sp--;
293 s[sp] &= s[sp + 1];
294 break;
295 case CEXPR_OR:
296 BUG_ON(sp < 1);
297 sp--;
298 s[sp] |= s[sp + 1];
299 break;
300 case CEXPR_ATTR:
301 if (sp == (CEXPR_MAXDEPTH - 1))
302 return 0;
303 switch (e->attr) {
304 case CEXPR_USER:
305 val1 = scontext->user;
306 val2 = tcontext->user;
307 break;
308 case CEXPR_TYPE:
309 val1 = scontext->type;
310 val2 = tcontext->type;
311 break;
312 case CEXPR_ROLE:
313 val1 = scontext->role;
314 val2 = tcontext->role;
315 r1 = policydb.role_val_to_struct[val1 - 1];
316 r2 = policydb.role_val_to_struct[val2 - 1];
317 switch (e->op) {
318 case CEXPR_DOM:
319 s[++sp] = ebitmap_get_bit(&r1->dominates,
320 val2 - 1);
321 continue;
322 case CEXPR_DOMBY:
323 s[++sp] = ebitmap_get_bit(&r2->dominates,
324 val1 - 1);
325 continue;
326 case CEXPR_INCOMP:
327 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
328 val2 - 1) &&
329 !ebitmap_get_bit(&r2->dominates,
330 val1 - 1));
331 continue;
332 default:
333 break;
334 }
335 break;
336 case CEXPR_L1L2:
337 l1 = &(scontext->range.level[0]);
338 l2 = &(tcontext->range.level[0]);
339 goto mls_ops;
340 case CEXPR_L1H2:
341 l1 = &(scontext->range.level[0]);
342 l2 = &(tcontext->range.level[1]);
343 goto mls_ops;
344 case CEXPR_H1L2:
345 l1 = &(scontext->range.level[1]);
346 l2 = &(tcontext->range.level[0]);
347 goto mls_ops;
348 case CEXPR_H1H2:
349 l1 = &(scontext->range.level[1]);
350 l2 = &(tcontext->range.level[1]);
351 goto mls_ops;
352 case CEXPR_L1H1:
353 l1 = &(scontext->range.level[0]);
354 l2 = &(scontext->range.level[1]);
355 goto mls_ops;
356 case CEXPR_L2H2:
357 l1 = &(tcontext->range.level[0]);
358 l2 = &(tcontext->range.level[1]);
359 goto mls_ops;
360 mls_ops:
361 switch (e->op) {
362 case CEXPR_EQ:
363 s[++sp] = mls_level_eq(l1, l2);
364 continue;
365 case CEXPR_NEQ:
366 s[++sp] = !mls_level_eq(l1, l2);
367 continue;
368 case CEXPR_DOM:
369 s[++sp] = mls_level_dom(l1, l2);
370 continue;
371 case CEXPR_DOMBY:
372 s[++sp] = mls_level_dom(l2, l1);
373 continue;
374 case CEXPR_INCOMP:
375 s[++sp] = mls_level_incomp(l2, l1);
376 continue;
377 default:
378 BUG();
379 return 0;
380 }
381 break;
382 default:
383 BUG();
384 return 0;
385 }
386
387 switch (e->op) {
388 case CEXPR_EQ:
389 s[++sp] = (val1 == val2);
390 break;
391 case CEXPR_NEQ:
392 s[++sp] = (val1 != val2);
393 break;
394 default:
395 BUG();
396 return 0;
397 }
398 break;
399 case CEXPR_NAMES:
400 if (sp == (CEXPR_MAXDEPTH-1))
401 return 0;
402 c = scontext;
403 if (e->attr & CEXPR_TARGET)
404 c = tcontext;
405 else if (e->attr & CEXPR_XTARGET) {
406 c = xcontext;
407 if (!c) {
408 BUG();
409 return 0;
410 }
411 }
412 if (e->attr & CEXPR_USER)
413 val1 = c->user;
414 else if (e->attr & CEXPR_ROLE)
415 val1 = c->role;
416 else if (e->attr & CEXPR_TYPE)
417 val1 = c->type;
418 else {
419 BUG();
420 return 0;
421 }
422
423 switch (e->op) {
424 case CEXPR_EQ:
425 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
426 break;
427 case CEXPR_NEQ:
428 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
429 break;
430 default:
431 BUG();
432 return 0;
433 }
434 break;
435 default:
436 BUG();
437 return 0;
438 }
439 }
440
441 BUG_ON(sp != 0);
442 return s[0];
443 }
444
445 /*
446 * security_dump_masked_av - dumps masked permissions during
447 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
448 */
449 static int dump_masked_av_helper(void *k, void *d, void *args)
450 {
451 struct perm_datum *pdatum = d;
452 char **permission_names = args;
453
454 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
455
456 permission_names[pdatum->value - 1] = (char *)k;
457
458 return 0;
459 }
460
461 static void security_dump_masked_av(struct context *scontext,
462 struct context *tcontext,
463 u16 tclass,
464 u32 permissions,
465 const char *reason)
466 {
467 struct common_datum *common_dat;
468 struct class_datum *tclass_dat;
469 struct audit_buffer *ab;
470 char *tclass_name;
471 char *scontext_name = NULL;
472 char *tcontext_name = NULL;
473 char *permission_names[32];
474 int index;
475 u32 length;
476 bool need_comma = false;
477
478 if (!permissions)
479 return;
480
481 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
482 tclass_dat = policydb.class_val_to_struct[tclass - 1];
483 common_dat = tclass_dat->comdatum;
484
485 /* init permission_names */
486 if (common_dat &&
487 hashtab_map(common_dat->permissions.table,
488 dump_masked_av_helper, permission_names) < 0)
489 goto out;
490
491 if (hashtab_map(tclass_dat->permissions.table,
492 dump_masked_av_helper, permission_names) < 0)
493 goto out;
494
495 /* get scontext/tcontext in text form */
496 if (context_struct_to_string(scontext,
497 &scontext_name, &length) < 0)
498 goto out;
499
500 if (context_struct_to_string(tcontext,
501 &tcontext_name, &length) < 0)
502 goto out;
503
504 /* audit a message */
505 ab = audit_log_start(current->audit_context,
506 GFP_ATOMIC, AUDIT_SELINUX_ERR);
507 if (!ab)
508 goto out;
509
510 audit_log_format(ab, "op=security_compute_av reason=%s "
511 "scontext=%s tcontext=%s tclass=%s perms=",
512 reason, scontext_name, tcontext_name, tclass_name);
513
514 for (index = 0; index < 32; index++) {
515 u32 mask = (1 << index);
516
517 if ((mask & permissions) == 0)
518 continue;
519
520 audit_log_format(ab, "%s%s",
521 need_comma ? "," : "",
522 permission_names[index]
523 ? permission_names[index] : "????");
524 need_comma = true;
525 }
526 audit_log_end(ab);
527 out:
528 /* release scontext/tcontext */
529 kfree(tcontext_name);
530 kfree(scontext_name);
531
532 return;
533 }
534
535 /*
536 * security_boundary_permission - drops violated permissions
537 * on boundary constraint.
538 */
539 static void type_attribute_bounds_av(struct context *scontext,
540 struct context *tcontext,
541 u16 tclass,
542 struct av_decision *avd)
543 {
544 struct context lo_scontext;
545 struct context lo_tcontext;
546 struct av_decision lo_avd;
547 struct type_datum *source;
548 struct type_datum *target;
549 u32 masked = 0;
550
551 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
552 scontext->type - 1);
553 BUG_ON(!source);
554
555 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
556 tcontext->type - 1);
557 BUG_ON(!target);
558
559 if (source->bounds) {
560 memset(&lo_avd, 0, sizeof(lo_avd));
561
562 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
563 lo_scontext.type = source->bounds;
564
565 context_struct_compute_av(&lo_scontext,
566 tcontext,
567 tclass,
568 &lo_avd);
569 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
570 return; /* no masked permission */
571 masked = ~lo_avd.allowed & avd->allowed;
572 }
573
574 if (target->bounds) {
575 memset(&lo_avd, 0, sizeof(lo_avd));
576
577 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
578 lo_tcontext.type = target->bounds;
579
580 context_struct_compute_av(scontext,
581 &lo_tcontext,
582 tclass,
583 &lo_avd);
584 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
585 return; /* no masked permission */
586 masked = ~lo_avd.allowed & avd->allowed;
587 }
588
589 if (source->bounds && target->bounds) {
590 memset(&lo_avd, 0, sizeof(lo_avd));
591 /*
592 * lo_scontext and lo_tcontext are already
593 * set up.
594 */
595
596 context_struct_compute_av(&lo_scontext,
597 &lo_tcontext,
598 tclass,
599 &lo_avd);
600 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
601 return; /* no masked permission */
602 masked = ~lo_avd.allowed & avd->allowed;
603 }
604
605 if (masked) {
606 /* mask violated permissions */
607 avd->allowed &= ~masked;
608
609 /* audit masked permissions */
610 security_dump_masked_av(scontext, tcontext,
611 tclass, masked, "bounds");
612 }
613 }
614
615 /*
616 * Compute access vectors based on a context structure pair for
617 * the permissions in a particular class.
618 */
619 static void context_struct_compute_av(struct context *scontext,
620 struct context *tcontext,
621 u16 tclass,
622 struct av_decision *avd)
623 {
624 struct constraint_node *constraint;
625 struct role_allow *ra;
626 struct avtab_key avkey;
627 struct avtab_node *node;
628 struct class_datum *tclass_datum;
629 struct ebitmap *sattr, *tattr;
630 struct ebitmap_node *snode, *tnode;
631 unsigned int i, j;
632
633 avd->allowed = 0;
634 avd->auditallow = 0;
635 avd->auditdeny = 0xffffffff;
636
637 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
638 if (printk_ratelimit())
639 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
640 return;
641 }
642
643 tclass_datum = policydb.class_val_to_struct[tclass - 1];
644
645 /*
646 * If a specific type enforcement rule was defined for
647 * this permission check, then use it.
648 */
649 avkey.target_class = tclass;
650 avkey.specified = AVTAB_AV;
651 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
652 BUG_ON(!sattr);
653 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
654 BUG_ON(!tattr);
655 ebitmap_for_each_positive_bit(sattr, snode, i) {
656 ebitmap_for_each_positive_bit(tattr, tnode, j) {
657 avkey.source_type = i + 1;
658 avkey.target_type = j + 1;
659 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
660 node;
661 node = avtab_search_node_next(node, avkey.specified)) {
662 if (node->key.specified == AVTAB_ALLOWED)
663 avd->allowed |= node->datum.data;
664 else if (node->key.specified == AVTAB_AUDITALLOW)
665 avd->auditallow |= node->datum.data;
666 else if (node->key.specified == AVTAB_AUDITDENY)
667 avd->auditdeny &= node->datum.data;
668 }
669
670 /* Check conditional av table for additional permissions */
671 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
672
673 }
674 }
675
676 /*
677 * Remove any permissions prohibited by a constraint (this includes
678 * the MLS policy).
679 */
680 constraint = tclass_datum->constraints;
681 while (constraint) {
682 if ((constraint->permissions & (avd->allowed)) &&
683 !constraint_expr_eval(scontext, tcontext, NULL,
684 constraint->expr)) {
685 avd->allowed &= ~(constraint->permissions);
686 }
687 constraint = constraint->next;
688 }
689
690 /*
691 * If checking process transition permission and the
692 * role is changing, then check the (current_role, new_role)
693 * pair.
694 */
695 if (tclass == policydb.process_class &&
696 (avd->allowed & policydb.process_trans_perms) &&
697 scontext->role != tcontext->role) {
698 for (ra = policydb.role_allow; ra; ra = ra->next) {
699 if (scontext->role == ra->role &&
700 tcontext->role == ra->new_role)
701 break;
702 }
703 if (!ra)
704 avd->allowed &= ~policydb.process_trans_perms;
705 }
706
707 /*
708 * If the given source and target types have boundary
709 * constraint, lazy checks have to mask any violated
710 * permission and notice it to userspace via audit.
711 */
712 type_attribute_bounds_av(scontext, tcontext,
713 tclass, avd);
714 }
715
716 static int security_validtrans_handle_fail(struct context *ocontext,
717 struct context *ncontext,
718 struct context *tcontext,
719 u16 tclass)
720 {
721 char *o = NULL, *n = NULL, *t = NULL;
722 u32 olen, nlen, tlen;
723
724 if (context_struct_to_string(ocontext, &o, &olen))
725 goto out;
726 if (context_struct_to_string(ncontext, &n, &nlen))
727 goto out;
728 if (context_struct_to_string(tcontext, &t, &tlen))
729 goto out;
730 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
731 "security_validate_transition: denied for"
732 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
733 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
734 out:
735 kfree(o);
736 kfree(n);
737 kfree(t);
738
739 if (!selinux_enforcing)
740 return 0;
741 return -EPERM;
742 }
743
744 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
745 u16 orig_tclass)
746 {
747 struct context *ocontext;
748 struct context *ncontext;
749 struct context *tcontext;
750 struct class_datum *tclass_datum;
751 struct constraint_node *constraint;
752 u16 tclass;
753 int rc = 0;
754
755 if (!ss_initialized)
756 return 0;
757
758 read_lock(&policy_rwlock);
759
760 tclass = unmap_class(orig_tclass);
761
762 if (!tclass || tclass > policydb.p_classes.nprim) {
763 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
764 __func__, tclass);
765 rc = -EINVAL;
766 goto out;
767 }
768 tclass_datum = policydb.class_val_to_struct[tclass - 1];
769
770 ocontext = sidtab_search(&sidtab, oldsid);
771 if (!ocontext) {
772 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
773 __func__, oldsid);
774 rc = -EINVAL;
775 goto out;
776 }
777
778 ncontext = sidtab_search(&sidtab, newsid);
779 if (!ncontext) {
780 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
781 __func__, newsid);
782 rc = -EINVAL;
783 goto out;
784 }
785
786 tcontext = sidtab_search(&sidtab, tasksid);
787 if (!tcontext) {
788 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
789 __func__, tasksid);
790 rc = -EINVAL;
791 goto out;
792 }
793
794 constraint = tclass_datum->validatetrans;
795 while (constraint) {
796 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
797 constraint->expr)) {
798 rc = security_validtrans_handle_fail(ocontext, ncontext,
799 tcontext, tclass);
800 goto out;
801 }
802 constraint = constraint->next;
803 }
804
805 out:
806 read_unlock(&policy_rwlock);
807 return rc;
808 }
809
810 /*
811 * security_bounded_transition - check whether the given
812 * transition is directed to bounded, or not.
813 * It returns 0, if @newsid is bounded by @oldsid.
814 * Otherwise, it returns error code.
815 *
816 * @oldsid : current security identifier
817 * @newsid : destinated security identifier
818 */
819 int security_bounded_transition(u32 old_sid, u32 new_sid)
820 {
821 struct context *old_context, *new_context;
822 struct type_datum *type;
823 int index;
824 int rc;
825
826 read_lock(&policy_rwlock);
827
828 rc = -EINVAL;
829 old_context = sidtab_search(&sidtab, old_sid);
830 if (!old_context) {
831 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
832 __func__, old_sid);
833 goto out;
834 }
835
836 rc = -EINVAL;
837 new_context = sidtab_search(&sidtab, new_sid);
838 if (!new_context) {
839 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
840 __func__, new_sid);
841 goto out;
842 }
843
844 rc = 0;
845 /* type/domain unchanged */
846 if (old_context->type == new_context->type)
847 goto out;
848
849 index = new_context->type;
850 while (true) {
851 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
852 index - 1);
853 BUG_ON(!type);
854
855 /* not bounded anymore */
856 rc = -EPERM;
857 if (!type->bounds)
858 break;
859
860 /* @newsid is bounded by @oldsid */
861 rc = 0;
862 if (type->bounds == old_context->type)
863 break;
864
865 index = type->bounds;
866 }
867
868 if (rc) {
869 char *old_name = NULL;
870 char *new_name = NULL;
871 u32 length;
872
873 if (!context_struct_to_string(old_context,
874 &old_name, &length) &&
875 !context_struct_to_string(new_context,
876 &new_name, &length)) {
877 audit_log(current->audit_context,
878 GFP_ATOMIC, AUDIT_SELINUX_ERR,
879 "op=security_bounded_transition "
880 "result=denied "
881 "oldcontext=%s newcontext=%s",
882 old_name, new_name);
883 }
884 kfree(new_name);
885 kfree(old_name);
886 }
887 out:
888 read_unlock(&policy_rwlock);
889
890 return rc;
891 }
892
893 static void avd_init(struct av_decision *avd)
894 {
895 avd->allowed = 0;
896 avd->auditallow = 0;
897 avd->auditdeny = 0xffffffff;
898 avd->seqno = latest_granting;
899 avd->flags = 0;
900 }
901
902
903 /**
904 * security_compute_av - Compute access vector decisions.
905 * @ssid: source security identifier
906 * @tsid: target security identifier
907 * @tclass: target security class
908 * @avd: access vector decisions
909 *
910 * Compute a set of access vector decisions based on the
911 * SID pair (@ssid, @tsid) for the permissions in @tclass.
912 */
913 void security_compute_av(u32 ssid,
914 u32 tsid,
915 u16 orig_tclass,
916 struct av_decision *avd)
917 {
918 u16 tclass;
919 struct context *scontext = NULL, *tcontext = NULL;
920
921 read_lock(&policy_rwlock);
922 avd_init(avd);
923 if (!ss_initialized)
924 goto allow;
925
926 scontext = sidtab_search(&sidtab, ssid);
927 if (!scontext) {
928 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
929 __func__, ssid);
930 goto out;
931 }
932
933 /* permissive domain? */
934 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
935 avd->flags |= AVD_FLAGS_PERMISSIVE;
936
937 tcontext = sidtab_search(&sidtab, tsid);
938 if (!tcontext) {
939 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
940 __func__, tsid);
941 goto out;
942 }
943
944 tclass = unmap_class(orig_tclass);
945 if (unlikely(orig_tclass && !tclass)) {
946 if (policydb.allow_unknown)
947 goto allow;
948 goto out;
949 }
950 context_struct_compute_av(scontext, tcontext, tclass, avd);
951 map_decision(orig_tclass, avd, policydb.allow_unknown);
952 out:
953 read_unlock(&policy_rwlock);
954 return;
955 allow:
956 avd->allowed = 0xffffffff;
957 goto out;
958 }
959
960 void security_compute_av_user(u32 ssid,
961 u32 tsid,
962 u16 tclass,
963 struct av_decision *avd)
964 {
965 struct context *scontext = NULL, *tcontext = NULL;
966
967 read_lock(&policy_rwlock);
968 avd_init(avd);
969 if (!ss_initialized)
970 goto allow;
971
972 scontext = sidtab_search(&sidtab, ssid);
973 if (!scontext) {
974 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
975 __func__, ssid);
976 goto out;
977 }
978
979 /* permissive domain? */
980 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
981 avd->flags |= AVD_FLAGS_PERMISSIVE;
982
983 tcontext = sidtab_search(&sidtab, tsid);
984 if (!tcontext) {
985 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
986 __func__, tsid);
987 goto out;
988 }
989
990 if (unlikely(!tclass)) {
991 if (policydb.allow_unknown)
992 goto allow;
993 goto out;
994 }
995
996 context_struct_compute_av(scontext, tcontext, tclass, avd);
997 out:
998 read_unlock(&policy_rwlock);
999 return;
1000 allow:
1001 avd->allowed = 0xffffffff;
1002 goto out;
1003 }
1004
1005 /*
1006 * Write the security context string representation of
1007 * the context structure `context' into a dynamically
1008 * allocated string of the correct size. Set `*scontext'
1009 * to point to this string and set `*scontext_len' to
1010 * the length of the string.
1011 */
1012 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1013 {
1014 char *scontextp;
1015
1016 if (scontext)
1017 *scontext = NULL;
1018 *scontext_len = 0;
1019
1020 if (context->len) {
1021 *scontext_len = context->len;
1022 if (scontext) {
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 }
1027 return 0;
1028 }
1029
1030 /* Compute the size of the context. */
1031 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1033 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1034 *scontext_len += mls_compute_context_len(context);
1035
1036 if (!scontext)
1037 return 0;
1038
1039 /* Allocate space for the context; caller must free this space. */
1040 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1041 if (!scontextp)
1042 return -ENOMEM;
1043 *scontext = scontextp;
1044
1045 /*
1046 * Copy the user name, role name and type name into the context.
1047 */
1048 sprintf(scontextp, "%s:%s:%s",
1049 sym_name(&policydb, SYM_USERS, context->user - 1),
1050 sym_name(&policydb, SYM_ROLES, context->role - 1),
1051 sym_name(&policydb, SYM_TYPES, context->type - 1));
1052 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1054 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1055
1056 mls_sid_to_context(context, &scontextp);
1057
1058 *scontextp = 0;
1059
1060 return 0;
1061 }
1062
1063 #include "initial_sid_to_string.h"
1064
1065 const char *security_get_initial_sid_context(u32 sid)
1066 {
1067 if (unlikely(sid > SECINITSID_NUM))
1068 return NULL;
1069 return initial_sid_to_string[sid];
1070 }
1071
1072 static int security_sid_to_context_core(u32 sid, char **scontext,
1073 u32 *scontext_len, int force)
1074 {
1075 struct context *context;
1076 int rc = 0;
1077
1078 if (scontext)
1079 *scontext = NULL;
1080 *scontext_len = 0;
1081
1082 if (!ss_initialized) {
1083 if (sid <= SECINITSID_NUM) {
1084 char *scontextp;
1085
1086 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1087 if (!scontext)
1088 goto out;
1089 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1090 if (!scontextp) {
1091 rc = -ENOMEM;
1092 goto out;
1093 }
1094 strcpy(scontextp, initial_sid_to_string[sid]);
1095 *scontext = scontextp;
1096 goto out;
1097 }
1098 printk(KERN_ERR "SELinux: %s: called before initial "
1099 "load_policy on unknown SID %d\n", __func__, sid);
1100 rc = -EINVAL;
1101 goto out;
1102 }
1103 read_lock(&policy_rwlock);
1104 if (force)
1105 context = sidtab_search_force(&sidtab, sid);
1106 else
1107 context = sidtab_search(&sidtab, sid);
1108 if (!context) {
1109 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1110 __func__, sid);
1111 rc = -EINVAL;
1112 goto out_unlock;
1113 }
1114 rc = context_struct_to_string(context, scontext, scontext_len);
1115 out_unlock:
1116 read_unlock(&policy_rwlock);
1117 out:
1118 return rc;
1119
1120 }
1121
1122 /**
1123 * security_sid_to_context - Obtain a context for a given SID.
1124 * @sid: security identifier, SID
1125 * @scontext: security context
1126 * @scontext_len: length in bytes
1127 *
1128 * Write the string representation of the context associated with @sid
1129 * into a dynamically allocated string of the correct size. Set @scontext
1130 * to point to this string and set @scontext_len to the length of the string.
1131 */
1132 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1133 {
1134 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1135 }
1136
1137 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1138 {
1139 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1140 }
1141
1142 /*
1143 * Caveat: Mutates scontext.
1144 */
1145 static int string_to_context_struct(struct policydb *pol,
1146 struct sidtab *sidtabp,
1147 char *scontext,
1148 u32 scontext_len,
1149 struct context *ctx,
1150 u32 def_sid)
1151 {
1152 struct role_datum *role;
1153 struct type_datum *typdatum;
1154 struct user_datum *usrdatum;
1155 char *scontextp, *p, oldc;
1156 int rc = 0;
1157
1158 context_init(ctx);
1159
1160 /* Parse the security context. */
1161
1162 rc = -EINVAL;
1163 scontextp = (char *) scontext;
1164
1165 /* Extract the user. */
1166 p = scontextp;
1167 while (*p && *p != ':')
1168 p++;
1169
1170 if (*p == 0)
1171 goto out;
1172
1173 *p++ = 0;
1174
1175 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1176 if (!usrdatum)
1177 goto out;
1178
1179 ctx->user = usrdatum->value;
1180
1181 /* Extract role. */
1182 scontextp = p;
1183 while (*p && *p != ':')
1184 p++;
1185
1186 if (*p == 0)
1187 goto out;
1188
1189 *p++ = 0;
1190
1191 role = hashtab_search(pol->p_roles.table, scontextp);
1192 if (!role)
1193 goto out;
1194 ctx->role = role->value;
1195
1196 /* Extract type. */
1197 scontextp = p;
1198 while (*p && *p != ':')
1199 p++;
1200 oldc = *p;
1201 *p++ = 0;
1202
1203 typdatum = hashtab_search(pol->p_types.table, scontextp);
1204 if (!typdatum || typdatum->attribute)
1205 goto out;
1206
1207 ctx->type = typdatum->value;
1208
1209 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1210 if (rc)
1211 goto out;
1212
1213 rc = -EINVAL;
1214 if ((p - scontext) < scontext_len)
1215 goto out;
1216
1217 /* Check the validity of the new context. */
1218 if (!policydb_context_isvalid(pol, ctx))
1219 goto out;
1220 rc = 0;
1221 out:
1222 if (rc)
1223 context_destroy(ctx);
1224 return rc;
1225 }
1226
1227 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1228 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1229 int force)
1230 {
1231 char *scontext2, *str = NULL;
1232 struct context context;
1233 int rc = 0;
1234
1235 if (!ss_initialized) {
1236 int i;
1237
1238 for (i = 1; i < SECINITSID_NUM; i++) {
1239 if (!strcmp(initial_sid_to_string[i], scontext)) {
1240 *sid = i;
1241 return 0;
1242 }
1243 }
1244 *sid = SECINITSID_KERNEL;
1245 return 0;
1246 }
1247 *sid = SECSID_NULL;
1248
1249 /* Copy the string so that we can modify the copy as we parse it. */
1250 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1251 if (!scontext2)
1252 return -ENOMEM;
1253 memcpy(scontext2, scontext, scontext_len);
1254 scontext2[scontext_len] = 0;
1255
1256 if (force) {
1257 /* Save another copy for storing in uninterpreted form */
1258 rc = -ENOMEM;
1259 str = kstrdup(scontext2, gfp_flags);
1260 if (!str)
1261 goto out;
1262 }
1263
1264 read_lock(&policy_rwlock);
1265 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1266 scontext_len, &context, def_sid);
1267 if (rc == -EINVAL && force) {
1268 context.str = str;
1269 context.len = scontext_len;
1270 str = NULL;
1271 } else if (rc)
1272 goto out_unlock;
1273 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1274 context_destroy(&context);
1275 out_unlock:
1276 read_unlock(&policy_rwlock);
1277 out:
1278 kfree(scontext2);
1279 kfree(str);
1280 return rc;
1281 }
1282
1283 /**
1284 * security_context_to_sid - Obtain a SID for a given security context.
1285 * @scontext: security context
1286 * @scontext_len: length in bytes
1287 * @sid: security identifier, SID
1288 *
1289 * Obtains a SID associated with the security context that
1290 * has the string representation specified by @scontext.
1291 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1292 * memory is available, or 0 on success.
1293 */
1294 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1295 {
1296 return security_context_to_sid_core(scontext, scontext_len,
1297 sid, SECSID_NULL, GFP_KERNEL, 0);
1298 }
1299
1300 /**
1301 * security_context_to_sid_default - Obtain a SID for a given security context,
1302 * falling back to specified default if needed.
1303 *
1304 * @scontext: security context
1305 * @scontext_len: length in bytes
1306 * @sid: security identifier, SID
1307 * @def_sid: default SID to assign on error
1308 *
1309 * Obtains a SID associated with the security context that
1310 * has the string representation specified by @scontext.
1311 * The default SID is passed to the MLS layer to be used to allow
1312 * kernel labeling of the MLS field if the MLS field is not present
1313 * (for upgrading to MLS without full relabel).
1314 * Implicitly forces adding of the context even if it cannot be mapped yet.
1315 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1316 * memory is available, or 0 on success.
1317 */
1318 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1319 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1320 {
1321 return security_context_to_sid_core(scontext, scontext_len,
1322 sid, def_sid, gfp_flags, 1);
1323 }
1324
1325 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1326 u32 *sid)
1327 {
1328 return security_context_to_sid_core(scontext, scontext_len,
1329 sid, SECSID_NULL, GFP_KERNEL, 1);
1330 }
1331
1332 static int compute_sid_handle_invalid_context(
1333 struct context *scontext,
1334 struct context *tcontext,
1335 u16 tclass,
1336 struct context *newcontext)
1337 {
1338 char *s = NULL, *t = NULL, *n = NULL;
1339 u32 slen, tlen, nlen;
1340
1341 if (context_struct_to_string(scontext, &s, &slen))
1342 goto out;
1343 if (context_struct_to_string(tcontext, &t, &tlen))
1344 goto out;
1345 if (context_struct_to_string(newcontext, &n, &nlen))
1346 goto out;
1347 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1348 "security_compute_sid: invalid context %s"
1349 " for scontext=%s"
1350 " tcontext=%s"
1351 " tclass=%s",
1352 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1353 out:
1354 kfree(s);
1355 kfree(t);
1356 kfree(n);
1357 if (!selinux_enforcing)
1358 return 0;
1359 return -EACCES;
1360 }
1361
1362 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1363 u32 stype, u32 ttype, u16 tclass,
1364 const char *objname)
1365 {
1366 struct filename_trans ft;
1367 struct filename_trans_datum *otype;
1368
1369 /*
1370 * Most filename trans rules are going to live in specific directories
1371 * like /dev or /var/run. This bitmap will quickly skip rule searches
1372 * if the ttype does not contain any rules.
1373 */
1374 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1375 return;
1376
1377 ft.stype = stype;
1378 ft.ttype = ttype;
1379 ft.tclass = tclass;
1380 ft.name = objname;
1381
1382 otype = hashtab_search(p->filename_trans, &ft);
1383 if (otype)
1384 newcontext->type = otype->otype;
1385 }
1386
1387 static int security_compute_sid(u32 ssid,
1388 u32 tsid,
1389 u16 orig_tclass,
1390 u32 specified,
1391 const char *objname,
1392 u32 *out_sid,
1393 bool kern)
1394 {
1395 struct class_datum *cladatum = NULL;
1396 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1397 struct role_trans *roletr = NULL;
1398 struct avtab_key avkey;
1399 struct avtab_datum *avdatum;
1400 struct avtab_node *node;
1401 u16 tclass;
1402 int rc = 0;
1403 bool sock;
1404
1405 if (!ss_initialized) {
1406 switch (orig_tclass) {
1407 case SECCLASS_PROCESS: /* kernel value */
1408 *out_sid = ssid;
1409 break;
1410 default:
1411 *out_sid = tsid;
1412 break;
1413 }
1414 goto out;
1415 }
1416
1417 context_init(&newcontext);
1418
1419 read_lock(&policy_rwlock);
1420
1421 if (kern) {
1422 tclass = unmap_class(orig_tclass);
1423 sock = security_is_socket_class(orig_tclass);
1424 } else {
1425 tclass = orig_tclass;
1426 sock = security_is_socket_class(map_class(tclass));
1427 }
1428
1429 scontext = sidtab_search(&sidtab, ssid);
1430 if (!scontext) {
1431 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1432 __func__, ssid);
1433 rc = -EINVAL;
1434 goto out_unlock;
1435 }
1436 tcontext = sidtab_search(&sidtab, tsid);
1437 if (!tcontext) {
1438 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1439 __func__, tsid);
1440 rc = -EINVAL;
1441 goto out_unlock;
1442 }
1443
1444 if (tclass && tclass <= policydb.p_classes.nprim)
1445 cladatum = policydb.class_val_to_struct[tclass - 1];
1446
1447 /* Set the user identity. */
1448 switch (specified) {
1449 case AVTAB_TRANSITION:
1450 case AVTAB_CHANGE:
1451 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1452 newcontext.user = tcontext->user;
1453 } else {
1454 /* notice this gets both DEFAULT_SOURCE and unset */
1455 /* Use the process user identity. */
1456 newcontext.user = scontext->user;
1457 }
1458 break;
1459 case AVTAB_MEMBER:
1460 /* Use the related object owner. */
1461 newcontext.user = tcontext->user;
1462 break;
1463 }
1464
1465 /* Set the role to default values. */
1466 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1467 newcontext.role = scontext->role;
1468 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1469 newcontext.role = tcontext->role;
1470 } else {
1471 if ((tclass == policydb.process_class) || (sock == true))
1472 newcontext.role = scontext->role;
1473 else
1474 newcontext.role = OBJECT_R_VAL;
1475 }
1476
1477 /* Set the type to default values. */
1478 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1479 newcontext.type = scontext->type;
1480 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1481 newcontext.type = tcontext->type;
1482 } else {
1483 if ((tclass == policydb.process_class) || (sock == true)) {
1484 /* Use the type of process. */
1485 newcontext.type = scontext->type;
1486 } else {
1487 /* Use the type of the related object. */
1488 newcontext.type = tcontext->type;
1489 }
1490 }
1491
1492 /* Look for a type transition/member/change rule. */
1493 avkey.source_type = scontext->type;
1494 avkey.target_type = tcontext->type;
1495 avkey.target_class = tclass;
1496 avkey.specified = specified;
1497 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1498
1499 /* If no permanent rule, also check for enabled conditional rules */
1500 if (!avdatum) {
1501 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1502 for (; node; node = avtab_search_node_next(node, specified)) {
1503 if (node->key.specified & AVTAB_ENABLED) {
1504 avdatum = &node->datum;
1505 break;
1506 }
1507 }
1508 }
1509
1510 if (avdatum) {
1511 /* Use the type from the type transition/member/change rule. */
1512 newcontext.type = avdatum->data;
1513 }
1514
1515 /* if we have a objname this is a file trans check so check those rules */
1516 if (objname)
1517 filename_compute_type(&policydb, &newcontext, scontext->type,
1518 tcontext->type, tclass, objname);
1519
1520 /* Check for class-specific changes. */
1521 if (specified & AVTAB_TRANSITION) {
1522 /* Look for a role transition rule. */
1523 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1524 if ((roletr->role == scontext->role) &&
1525 (roletr->type == tcontext->type) &&
1526 (roletr->tclass == tclass)) {
1527 /* Use the role transition rule. */
1528 newcontext.role = roletr->new_role;
1529 break;
1530 }
1531 }
1532 }
1533
1534 /* Set the MLS attributes.
1535 This is done last because it may allocate memory. */
1536 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1537 &newcontext, sock);
1538 if (rc)
1539 goto out_unlock;
1540
1541 /* Check the validity of the context. */
1542 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1543 rc = compute_sid_handle_invalid_context(scontext,
1544 tcontext,
1545 tclass,
1546 &newcontext);
1547 if (rc)
1548 goto out_unlock;
1549 }
1550 /* Obtain the sid for the context. */
1551 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1552 out_unlock:
1553 read_unlock(&policy_rwlock);
1554 context_destroy(&newcontext);
1555 out:
1556 return rc;
1557 }
1558
1559 /**
1560 * security_transition_sid - Compute the SID for a new subject/object.
1561 * @ssid: source security identifier
1562 * @tsid: target security identifier
1563 * @tclass: target security class
1564 * @out_sid: security identifier for new subject/object
1565 *
1566 * Compute a SID to use for labeling a new subject or object in the
1567 * class @tclass based on a SID pair (@ssid, @tsid).
1568 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1569 * if insufficient memory is available, or %0 if the new SID was
1570 * computed successfully.
1571 */
1572 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1573 const struct qstr *qstr, u32 *out_sid)
1574 {
1575 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1576 qstr ? qstr->name : NULL, out_sid, true);
1577 }
1578
1579 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1580 const char *objname, u32 *out_sid)
1581 {
1582 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1583 objname, out_sid, false);
1584 }
1585
1586 /**
1587 * security_member_sid - Compute the SID for member selection.
1588 * @ssid: source security identifier
1589 * @tsid: target security identifier
1590 * @tclass: target security class
1591 * @out_sid: security identifier for selected member
1592 *
1593 * Compute a SID to use when selecting a member of a polyinstantiated
1594 * object of class @tclass based on a SID pair (@ssid, @tsid).
1595 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1596 * if insufficient memory is available, or %0 if the SID was
1597 * computed successfully.
1598 */
1599 int security_member_sid(u32 ssid,
1600 u32 tsid,
1601 u16 tclass,
1602 u32 *out_sid)
1603 {
1604 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1605 out_sid, false);
1606 }
1607
1608 /**
1609 * security_change_sid - Compute the SID for object relabeling.
1610 * @ssid: source security identifier
1611 * @tsid: target security identifier
1612 * @tclass: target security class
1613 * @out_sid: security identifier for selected member
1614 *
1615 * Compute a SID to use for relabeling an object of class @tclass
1616 * based on a SID pair (@ssid, @tsid).
1617 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1618 * if insufficient memory is available, or %0 if the SID was
1619 * computed successfully.
1620 */
1621 int security_change_sid(u32 ssid,
1622 u32 tsid,
1623 u16 tclass,
1624 u32 *out_sid)
1625 {
1626 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1627 out_sid, false);
1628 }
1629
1630 /* Clone the SID into the new SID table. */
1631 static int clone_sid(u32 sid,
1632 struct context *context,
1633 void *arg)
1634 {
1635 struct sidtab *s = arg;
1636
1637 if (sid > SECINITSID_NUM)
1638 return sidtab_insert(s, sid, context);
1639 else
1640 return 0;
1641 }
1642
1643 static inline int convert_context_handle_invalid_context(struct context *context)
1644 {
1645 char *s;
1646 u32 len;
1647
1648 if (selinux_enforcing)
1649 return -EINVAL;
1650
1651 if (!context_struct_to_string(context, &s, &len)) {
1652 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1653 kfree(s);
1654 }
1655 return 0;
1656 }
1657
1658 struct convert_context_args {
1659 struct policydb *oldp;
1660 struct policydb *newp;
1661 };
1662
1663 /*
1664 * Convert the values in the security context
1665 * structure `c' from the values specified
1666 * in the policy `p->oldp' to the values specified
1667 * in the policy `p->newp'. Verify that the
1668 * context is valid under the new policy.
1669 */
1670 static int convert_context(u32 key,
1671 struct context *c,
1672 void *p)
1673 {
1674 struct convert_context_args *args;
1675 struct context oldc;
1676 struct ocontext *oc;
1677 struct mls_range *range;
1678 struct role_datum *role;
1679 struct type_datum *typdatum;
1680 struct user_datum *usrdatum;
1681 char *s;
1682 u32 len;
1683 int rc = 0;
1684
1685 if (key <= SECINITSID_NUM)
1686 goto out;
1687
1688 args = p;
1689
1690 if (c->str) {
1691 struct context ctx;
1692
1693 rc = -ENOMEM;
1694 s = kstrdup(c->str, GFP_KERNEL);
1695 if (!s)
1696 goto out;
1697
1698 rc = string_to_context_struct(args->newp, NULL, s,
1699 c->len, &ctx, SECSID_NULL);
1700 kfree(s);
1701 if (!rc) {
1702 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1703 c->str);
1704 /* Replace string with mapped representation. */
1705 kfree(c->str);
1706 memcpy(c, &ctx, sizeof(*c));
1707 goto out;
1708 } else if (rc == -EINVAL) {
1709 /* Retain string representation for later mapping. */
1710 rc = 0;
1711 goto out;
1712 } else {
1713 /* Other error condition, e.g. ENOMEM. */
1714 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1715 c->str, -rc);
1716 goto out;
1717 }
1718 }
1719
1720 rc = context_cpy(&oldc, c);
1721 if (rc)
1722 goto out;
1723
1724 /* Convert the user. */
1725 rc = -EINVAL;
1726 usrdatum = hashtab_search(args->newp->p_users.table,
1727 sym_name(args->oldp, SYM_USERS, c->user - 1));
1728 if (!usrdatum)
1729 goto bad;
1730 c->user = usrdatum->value;
1731
1732 /* Convert the role. */
1733 rc = -EINVAL;
1734 role = hashtab_search(args->newp->p_roles.table,
1735 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1736 if (!role)
1737 goto bad;
1738 c->role = role->value;
1739
1740 /* Convert the type. */
1741 rc = -EINVAL;
1742 typdatum = hashtab_search(args->newp->p_types.table,
1743 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1744 if (!typdatum)
1745 goto bad;
1746 c->type = typdatum->value;
1747
1748 /* Convert the MLS fields if dealing with MLS policies */
1749 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1750 rc = mls_convert_context(args->oldp, args->newp, c);
1751 if (rc)
1752 goto bad;
1753 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1754 /*
1755 * Switching between MLS and non-MLS policy:
1756 * free any storage used by the MLS fields in the
1757 * context for all existing entries in the sidtab.
1758 */
1759 mls_context_destroy(c);
1760 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1761 /*
1762 * Switching between non-MLS and MLS policy:
1763 * ensure that the MLS fields of the context for all
1764 * existing entries in the sidtab are filled in with a
1765 * suitable default value, likely taken from one of the
1766 * initial SIDs.
1767 */
1768 oc = args->newp->ocontexts[OCON_ISID];
1769 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1770 oc = oc->next;
1771 rc = -EINVAL;
1772 if (!oc) {
1773 printk(KERN_ERR "SELinux: unable to look up"
1774 " the initial SIDs list\n");
1775 goto bad;
1776 }
1777 range = &oc->context[0].range;
1778 rc = mls_range_set(c, range);
1779 if (rc)
1780 goto bad;
1781 }
1782
1783 /* Check the validity of the new context. */
1784 if (!policydb_context_isvalid(args->newp, c)) {
1785 rc = convert_context_handle_invalid_context(&oldc);
1786 if (rc)
1787 goto bad;
1788 }
1789
1790 context_destroy(&oldc);
1791
1792 rc = 0;
1793 out:
1794 return rc;
1795 bad:
1796 /* Map old representation to string and save it. */
1797 rc = context_struct_to_string(&oldc, &s, &len);
1798 if (rc)
1799 return rc;
1800 context_destroy(&oldc);
1801 context_destroy(c);
1802 c->str = s;
1803 c->len = len;
1804 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1805 c->str);
1806 rc = 0;
1807 goto out;
1808 }
1809
1810 static void security_load_policycaps(void)
1811 {
1812 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1813 POLICYDB_CAPABILITY_NETPEER);
1814 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1815 POLICYDB_CAPABILITY_OPENPERM);
1816 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1817 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1818 }
1819
1820 static int security_preserve_bools(struct policydb *p);
1821
1822 /**
1823 * security_load_policy - Load a security policy configuration.
1824 * @data: binary policy data
1825 * @len: length of data in bytes
1826 *
1827 * Load a new set of security policy configuration data,
1828 * validate it and convert the SID table as necessary.
1829 * This function will flush the access vector cache after
1830 * loading the new policy.
1831 */
1832 int security_load_policy(void *data, size_t len)
1833 {
1834 struct policydb oldpolicydb, newpolicydb;
1835 struct sidtab oldsidtab, newsidtab;
1836 struct selinux_mapping *oldmap, *map = NULL;
1837 struct convert_context_args args;
1838 u32 seqno;
1839 u16 map_size;
1840 int rc = 0;
1841 struct policy_file file = { data, len }, *fp = &file;
1842
1843 if (!ss_initialized) {
1844 avtab_cache_init();
1845 rc = policydb_read(&policydb, fp);
1846 if (rc) {
1847 avtab_cache_destroy();
1848 return rc;
1849 }
1850
1851 policydb.len = len;
1852 rc = selinux_set_mapping(&policydb, secclass_map,
1853 &current_mapping,
1854 &current_mapping_size);
1855 if (rc) {
1856 policydb_destroy(&policydb);
1857 avtab_cache_destroy();
1858 return rc;
1859 }
1860
1861 rc = policydb_load_isids(&policydb, &sidtab);
1862 if (rc) {
1863 policydb_destroy(&policydb);
1864 avtab_cache_destroy();
1865 return rc;
1866 }
1867
1868 security_load_policycaps();
1869 ss_initialized = 1;
1870 seqno = ++latest_granting;
1871 selinux_complete_init();
1872 avc_ss_reset(seqno);
1873 selnl_notify_policyload(seqno);
1874 selinux_status_update_policyload(seqno);
1875 selinux_netlbl_cache_invalidate();
1876 selinux_xfrm_notify_policyload();
1877 return 0;
1878 }
1879
1880 #if 0
1881 sidtab_hash_eval(&sidtab, "sids");
1882 #endif
1883
1884 rc = policydb_read(&newpolicydb, fp);
1885 if (rc)
1886 return rc;
1887
1888 newpolicydb.len = len;
1889 /* If switching between different policy types, log MLS status */
1890 if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1891 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1892 else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1893 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1894
1895 rc = policydb_load_isids(&newpolicydb, &newsidtab);
1896 if (rc) {
1897 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1898 policydb_destroy(&newpolicydb);
1899 return rc;
1900 }
1901
1902 rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1903 if (rc)
1904 goto err;
1905
1906 rc = security_preserve_bools(&newpolicydb);
1907 if (rc) {
1908 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1909 goto err;
1910 }
1911
1912 /* Clone the SID table. */
1913 sidtab_shutdown(&sidtab);
1914
1915 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1916 if (rc)
1917 goto err;
1918
1919 /*
1920 * Convert the internal representations of contexts
1921 * in the new SID table.
1922 */
1923 args.oldp = &policydb;
1924 args.newp = &newpolicydb;
1925 rc = sidtab_map(&newsidtab, convert_context, &args);
1926 if (rc) {
1927 printk(KERN_ERR "SELinux: unable to convert the internal"
1928 " representation of contexts in the new SID"
1929 " table\n");
1930 goto err;
1931 }
1932
1933 /* Save the old policydb and SID table to free later. */
1934 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1935 sidtab_set(&oldsidtab, &sidtab);
1936
1937 /* Install the new policydb and SID table. */
1938 write_lock_irq(&policy_rwlock);
1939 memcpy(&policydb, &newpolicydb, sizeof policydb);
1940 sidtab_set(&sidtab, &newsidtab);
1941 security_load_policycaps();
1942 oldmap = current_mapping;
1943 current_mapping = map;
1944 current_mapping_size = map_size;
1945 seqno = ++latest_granting;
1946 write_unlock_irq(&policy_rwlock);
1947
1948 /* Free the old policydb and SID table. */
1949 policydb_destroy(&oldpolicydb);
1950 sidtab_destroy(&oldsidtab);
1951 kfree(oldmap);
1952
1953 avc_ss_reset(seqno);
1954 selnl_notify_policyload(seqno);
1955 selinux_status_update_policyload(seqno);
1956 selinux_netlbl_cache_invalidate();
1957 selinux_xfrm_notify_policyload();
1958
1959 return 0;
1960
1961 err:
1962 kfree(map);
1963 sidtab_destroy(&newsidtab);
1964 policydb_destroy(&newpolicydb);
1965 return rc;
1966
1967 }
1968
1969 size_t security_policydb_len(void)
1970 {
1971 size_t len;
1972
1973 read_lock(&policy_rwlock);
1974 len = policydb.len;
1975 read_unlock(&policy_rwlock);
1976
1977 return len;
1978 }
1979
1980 /**
1981 * security_port_sid - Obtain the SID for a port.
1982 * @protocol: protocol number
1983 * @port: port number
1984 * @out_sid: security identifier
1985 */
1986 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1987 {
1988 struct ocontext *c;
1989 int rc = 0;
1990
1991 read_lock(&policy_rwlock);
1992
1993 c = policydb.ocontexts[OCON_PORT];
1994 while (c) {
1995 if (c->u.port.protocol == protocol &&
1996 c->u.port.low_port <= port &&
1997 c->u.port.high_port >= port)
1998 break;
1999 c = c->next;
2000 }
2001
2002 if (c) {
2003 if (!c->sid[0]) {
2004 rc = sidtab_context_to_sid(&sidtab,
2005 &c->context[0],
2006 &c->sid[0]);
2007 if (rc)
2008 goto out;
2009 }
2010 *out_sid = c->sid[0];
2011 } else {
2012 *out_sid = SECINITSID_PORT;
2013 }
2014
2015 out:
2016 read_unlock(&policy_rwlock);
2017 return rc;
2018 }
2019
2020 /**
2021 * security_netif_sid - Obtain the SID for a network interface.
2022 * @name: interface name
2023 * @if_sid: interface SID
2024 */
2025 int security_netif_sid(char *name, u32 *if_sid)
2026 {
2027 int rc = 0;
2028 struct ocontext *c;
2029
2030 read_lock(&policy_rwlock);
2031
2032 c = policydb.ocontexts[OCON_NETIF];
2033 while (c) {
2034 if (strcmp(name, c->u.name) == 0)
2035 break;
2036 c = c->next;
2037 }
2038
2039 if (c) {
2040 if (!c->sid[0] || !c->sid[1]) {
2041 rc = sidtab_context_to_sid(&sidtab,
2042 &c->context[0],
2043 &c->sid[0]);
2044 if (rc)
2045 goto out;
2046 rc = sidtab_context_to_sid(&sidtab,
2047 &c->context[1],
2048 &c->sid[1]);
2049 if (rc)
2050 goto out;
2051 }
2052 *if_sid = c->sid[0];
2053 } else
2054 *if_sid = SECINITSID_NETIF;
2055
2056 out:
2057 read_unlock(&policy_rwlock);
2058 return rc;
2059 }
2060
2061 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2062 {
2063 int i, fail = 0;
2064
2065 for (i = 0; i < 4; i++)
2066 if (addr[i] != (input[i] & mask[i])) {
2067 fail = 1;
2068 break;
2069 }
2070
2071 return !fail;
2072 }
2073
2074 /**
2075 * security_node_sid - Obtain the SID for a node (host).
2076 * @domain: communication domain aka address family
2077 * @addrp: address
2078 * @addrlen: address length in bytes
2079 * @out_sid: security identifier
2080 */
2081 int security_node_sid(u16 domain,
2082 void *addrp,
2083 u32 addrlen,
2084 u32 *out_sid)
2085 {
2086 int rc;
2087 struct ocontext *c;
2088
2089 read_lock(&policy_rwlock);
2090
2091 switch (domain) {
2092 case AF_INET: {
2093 u32 addr;
2094
2095 rc = -EINVAL;
2096 if (addrlen != sizeof(u32))
2097 goto out;
2098
2099 addr = *((u32 *)addrp);
2100
2101 c = policydb.ocontexts[OCON_NODE];
2102 while (c) {
2103 if (c->u.node.addr == (addr & c->u.node.mask))
2104 break;
2105 c = c->next;
2106 }
2107 break;
2108 }
2109
2110 case AF_INET6:
2111 rc = -EINVAL;
2112 if (addrlen != sizeof(u64) * 2)
2113 goto out;
2114 c = policydb.ocontexts[OCON_NODE6];
2115 while (c) {
2116 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2117 c->u.node6.mask))
2118 break;
2119 c = c->next;
2120 }
2121 break;
2122
2123 default:
2124 rc = 0;
2125 *out_sid = SECINITSID_NODE;
2126 goto out;
2127 }
2128
2129 if (c) {
2130 if (!c->sid[0]) {
2131 rc = sidtab_context_to_sid(&sidtab,
2132 &c->context[0],
2133 &c->sid[0]);
2134 if (rc)
2135 goto out;
2136 }
2137 *out_sid = c->sid[0];
2138 } else {
2139 *out_sid = SECINITSID_NODE;
2140 }
2141
2142 rc = 0;
2143 out:
2144 read_unlock(&policy_rwlock);
2145 return rc;
2146 }
2147
2148 #define SIDS_NEL 25
2149
2150 /**
2151 * security_get_user_sids - Obtain reachable SIDs for a user.
2152 * @fromsid: starting SID
2153 * @username: username
2154 * @sids: array of reachable SIDs for user
2155 * @nel: number of elements in @sids
2156 *
2157 * Generate the set of SIDs for legal security contexts
2158 * for a given user that can be reached by @fromsid.
2159 * Set *@sids to point to a dynamically allocated
2160 * array containing the set of SIDs. Set *@nel to the
2161 * number of elements in the array.
2162 */
2163
2164 int security_get_user_sids(u32 fromsid,
2165 char *username,
2166 u32 **sids,
2167 u32 *nel)
2168 {
2169 struct context *fromcon, usercon;
2170 u32 *mysids = NULL, *mysids2, sid;
2171 u32 mynel = 0, maxnel = SIDS_NEL;
2172 struct user_datum *user;
2173 struct role_datum *role;
2174 struct ebitmap_node *rnode, *tnode;
2175 int rc = 0, i, j;
2176
2177 *sids = NULL;
2178 *nel = 0;
2179
2180 if (!ss_initialized)
2181 goto out;
2182
2183 read_lock(&policy_rwlock);
2184
2185 context_init(&usercon);
2186
2187 rc = -EINVAL;
2188 fromcon = sidtab_search(&sidtab, fromsid);
2189 if (!fromcon)
2190 goto out_unlock;
2191
2192 rc = -EINVAL;
2193 user = hashtab_search(policydb.p_users.table, username);
2194 if (!user)
2195 goto out_unlock;
2196
2197 usercon.user = user->value;
2198
2199 rc = -ENOMEM;
2200 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2201 if (!mysids)
2202 goto out_unlock;
2203
2204 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2205 role = policydb.role_val_to_struct[i];
2206 usercon.role = i + 1;
2207 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2208 usercon.type = j + 1;
2209
2210 if (mls_setup_user_range(fromcon, user, &usercon))
2211 continue;
2212
2213 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2214 if (rc)
2215 goto out_unlock;
2216 if (mynel < maxnel) {
2217 mysids[mynel++] = sid;
2218 } else {
2219 rc = -ENOMEM;
2220 maxnel += SIDS_NEL;
2221 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2222 if (!mysids2)
2223 goto out_unlock;
2224 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2225 kfree(mysids);
2226 mysids = mysids2;
2227 mysids[mynel++] = sid;
2228 }
2229 }
2230 }
2231 rc = 0;
2232 out_unlock:
2233 read_unlock(&policy_rwlock);
2234 if (rc || !mynel) {
2235 kfree(mysids);
2236 goto out;
2237 }
2238
2239 rc = -ENOMEM;
2240 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2241 if (!mysids2) {
2242 kfree(mysids);
2243 goto out;
2244 }
2245 for (i = 0, j = 0; i < mynel; i++) {
2246 struct av_decision dummy_avd;
2247 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2248 SECCLASS_PROCESS, /* kernel value */
2249 PROCESS__TRANSITION, AVC_STRICT,
2250 &dummy_avd);
2251 if (!rc)
2252 mysids2[j++] = mysids[i];
2253 cond_resched();
2254 }
2255 rc = 0;
2256 kfree(mysids);
2257 *sids = mysids2;
2258 *nel = j;
2259 out:
2260 return rc;
2261 }
2262
2263 /**
2264 * security_genfs_sid - Obtain a SID for a file in a filesystem
2265 * @fstype: filesystem type
2266 * @path: path from root of mount
2267 * @sclass: file security class
2268 * @sid: SID for path
2269 *
2270 * Obtain a SID to use for a file in a filesystem that
2271 * cannot support xattr or use a fixed labeling behavior like
2272 * transition SIDs or task SIDs.
2273 */
2274 int security_genfs_sid(const char *fstype,
2275 char *path,
2276 u16 orig_sclass,
2277 u32 *sid)
2278 {
2279 int len;
2280 u16 sclass;
2281 struct genfs *genfs;
2282 struct ocontext *c;
2283 int rc, cmp = 0;
2284
2285 while (path[0] == '/' && path[1] == '/')
2286 path++;
2287
2288 read_lock(&policy_rwlock);
2289
2290 sclass = unmap_class(orig_sclass);
2291 *sid = SECINITSID_UNLABELED;
2292
2293 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2294 cmp = strcmp(fstype, genfs->fstype);
2295 if (cmp <= 0)
2296 break;
2297 }
2298
2299 rc = -ENOENT;
2300 if (!genfs || cmp)
2301 goto out;
2302
2303 for (c = genfs->head; c; c = c->next) {
2304 len = strlen(c->u.name);
2305 if ((!c->v.sclass || sclass == c->v.sclass) &&
2306 (strncmp(c->u.name, path, len) == 0))
2307 break;
2308 }
2309
2310 rc = -ENOENT;
2311 if (!c)
2312 goto out;
2313
2314 if (!c->sid[0]) {
2315 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2316 if (rc)
2317 goto out;
2318 }
2319
2320 *sid = c->sid[0];
2321 rc = 0;
2322 out:
2323 read_unlock(&policy_rwlock);
2324 return rc;
2325 }
2326
2327 /**
2328 * security_fs_use - Determine how to handle labeling for a filesystem.
2329 * @sb: superblock in question
2330 */
2331 int security_fs_use(struct super_block *sb)
2332 {
2333 int rc = 0;
2334 struct ocontext *c;
2335 struct superblock_security_struct *sbsec = sb->s_security;
2336 const char *fstype = sb->s_type->name;
2337
2338 read_lock(&policy_rwlock);
2339
2340 c = policydb.ocontexts[OCON_FSUSE];
2341 while (c) {
2342 if (strcmp(fstype, c->u.name) == 0)
2343 break;
2344 c = c->next;
2345 }
2346
2347 if (c) {
2348 sbsec->behavior = c->v.behavior;
2349 if (!c->sid[0]) {
2350 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2351 &c->sid[0]);
2352 if (rc)
2353 goto out;
2354 }
2355 sbsec->sid = c->sid[0];
2356 } else {
2357 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, &sbsec->sid);
2358 if (rc) {
2359 sbsec->behavior = SECURITY_FS_USE_NONE;
2360 rc = 0;
2361 } else {
2362 sbsec->behavior = SECURITY_FS_USE_GENFS;
2363 }
2364 }
2365
2366 out:
2367 read_unlock(&policy_rwlock);
2368 return rc;
2369 }
2370
2371 int security_get_bools(int *len, char ***names, int **values)
2372 {
2373 int i, rc;
2374
2375 read_lock(&policy_rwlock);
2376 *names = NULL;
2377 *values = NULL;
2378
2379 rc = 0;
2380 *len = policydb.p_bools.nprim;
2381 if (!*len)
2382 goto out;
2383
2384 rc = -ENOMEM;
2385 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2386 if (!*names)
2387 goto err;
2388
2389 rc = -ENOMEM;
2390 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2391 if (!*values)
2392 goto err;
2393
2394 for (i = 0; i < *len; i++) {
2395 size_t name_len;
2396
2397 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2398 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2399
2400 rc = -ENOMEM;
2401 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2402 if (!(*names)[i])
2403 goto err;
2404
2405 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2406 (*names)[i][name_len - 1] = 0;
2407 }
2408 rc = 0;
2409 out:
2410 read_unlock(&policy_rwlock);
2411 return rc;
2412 err:
2413 if (*names) {
2414 for (i = 0; i < *len; i++)
2415 kfree((*names)[i]);
2416 }
2417 kfree(*values);
2418 goto out;
2419 }
2420
2421
2422 int security_set_bools(int len, int *values)
2423 {
2424 int i, rc;
2425 int lenp, seqno = 0;
2426 struct cond_node *cur;
2427
2428 write_lock_irq(&policy_rwlock);
2429
2430 rc = -EFAULT;
2431 lenp = policydb.p_bools.nprim;
2432 if (len != lenp)
2433 goto out;
2434
2435 for (i = 0; i < len; i++) {
2436 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2437 audit_log(current->audit_context, GFP_ATOMIC,
2438 AUDIT_MAC_CONFIG_CHANGE,
2439 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2440 sym_name(&policydb, SYM_BOOLS, i),
2441 !!values[i],
2442 policydb.bool_val_to_struct[i]->state,
2443 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2444 audit_get_sessionid(current));
2445 }
2446 if (values[i])
2447 policydb.bool_val_to_struct[i]->state = 1;
2448 else
2449 policydb.bool_val_to_struct[i]->state = 0;
2450 }
2451
2452 for (cur = policydb.cond_list; cur; cur = cur->next) {
2453 rc = evaluate_cond_node(&policydb, cur);
2454 if (rc)
2455 goto out;
2456 }
2457
2458 seqno = ++latest_granting;
2459 rc = 0;
2460 out:
2461 write_unlock_irq(&policy_rwlock);
2462 if (!rc) {
2463 avc_ss_reset(seqno);
2464 selnl_notify_policyload(seqno);
2465 selinux_status_update_policyload(seqno);
2466 selinux_xfrm_notify_policyload();
2467 }
2468 return rc;
2469 }
2470
2471 int security_get_bool_value(int bool)
2472 {
2473 int rc;
2474 int len;
2475
2476 read_lock(&policy_rwlock);
2477
2478 rc = -EFAULT;
2479 len = policydb.p_bools.nprim;
2480 if (bool >= len)
2481 goto out;
2482
2483 rc = policydb.bool_val_to_struct[bool]->state;
2484 out:
2485 read_unlock(&policy_rwlock);
2486 return rc;
2487 }
2488
2489 static int security_preserve_bools(struct policydb *p)
2490 {
2491 int rc, nbools = 0, *bvalues = NULL, i;
2492 char **bnames = NULL;
2493 struct cond_bool_datum *booldatum;
2494 struct cond_node *cur;
2495
2496 rc = security_get_bools(&nbools, &bnames, &bvalues);
2497 if (rc)
2498 goto out;
2499 for (i = 0; i < nbools; i++) {
2500 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2501 if (booldatum)
2502 booldatum->state = bvalues[i];
2503 }
2504 for (cur = p->cond_list; cur; cur = cur->next) {
2505 rc = evaluate_cond_node(p, cur);
2506 if (rc)
2507 goto out;
2508 }
2509
2510 out:
2511 if (bnames) {
2512 for (i = 0; i < nbools; i++)
2513 kfree(bnames[i]);
2514 }
2515 kfree(bnames);
2516 kfree(bvalues);
2517 return rc;
2518 }
2519
2520 /*
2521 * security_sid_mls_copy() - computes a new sid based on the given
2522 * sid and the mls portion of mls_sid.
2523 */
2524 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2525 {
2526 struct context *context1;
2527 struct context *context2;
2528 struct context newcon;
2529 char *s;
2530 u32 len;
2531 int rc;
2532
2533 rc = 0;
2534 if (!ss_initialized || !policydb.mls_enabled) {
2535 *new_sid = sid;
2536 goto out;
2537 }
2538
2539 context_init(&newcon);
2540
2541 read_lock(&policy_rwlock);
2542
2543 rc = -EINVAL;
2544 context1 = sidtab_search(&sidtab, sid);
2545 if (!context1) {
2546 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2547 __func__, sid);
2548 goto out_unlock;
2549 }
2550
2551 rc = -EINVAL;
2552 context2 = sidtab_search(&sidtab, mls_sid);
2553 if (!context2) {
2554 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2555 __func__, mls_sid);
2556 goto out_unlock;
2557 }
2558
2559 newcon.user = context1->user;
2560 newcon.role = context1->role;
2561 newcon.type = context1->type;
2562 rc = mls_context_cpy(&newcon, context2);
2563 if (rc)
2564 goto out_unlock;
2565
2566 /* Check the validity of the new context. */
2567 if (!policydb_context_isvalid(&policydb, &newcon)) {
2568 rc = convert_context_handle_invalid_context(&newcon);
2569 if (rc) {
2570 if (!context_struct_to_string(&newcon, &s, &len)) {
2571 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2572 "security_sid_mls_copy: invalid context %s", s);
2573 kfree(s);
2574 }
2575 goto out_unlock;
2576 }
2577 }
2578
2579 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2580 out_unlock:
2581 read_unlock(&policy_rwlock);
2582 context_destroy(&newcon);
2583 out:
2584 return rc;
2585 }
2586
2587 /**
2588 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2589 * @nlbl_sid: NetLabel SID
2590 * @nlbl_type: NetLabel labeling protocol type
2591 * @xfrm_sid: XFRM SID
2592 *
2593 * Description:
2594 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2595 * resolved into a single SID it is returned via @peer_sid and the function
2596 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2597 * returns a negative value. A table summarizing the behavior is below:
2598 *
2599 * | function return | @sid
2600 * ------------------------------+-----------------+-----------------
2601 * no peer labels | 0 | SECSID_NULL
2602 * single peer label | 0 | <peer_label>
2603 * multiple, consistent labels | 0 | <peer_label>
2604 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2605 *
2606 */
2607 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2608 u32 xfrm_sid,
2609 u32 *peer_sid)
2610 {
2611 int rc;
2612 struct context *nlbl_ctx;
2613 struct context *xfrm_ctx;
2614
2615 *peer_sid = SECSID_NULL;
2616
2617 /* handle the common (which also happens to be the set of easy) cases
2618 * right away, these two if statements catch everything involving a
2619 * single or absent peer SID/label */
2620 if (xfrm_sid == SECSID_NULL) {
2621 *peer_sid = nlbl_sid;
2622 return 0;
2623 }
2624 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2625 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2626 * is present */
2627 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2628 *peer_sid = xfrm_sid;
2629 return 0;
2630 }
2631
2632 /* we don't need to check ss_initialized here since the only way both
2633 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2634 * security server was initialized and ss_initialized was true */
2635 if (!policydb.mls_enabled)
2636 return 0;
2637
2638 read_lock(&policy_rwlock);
2639
2640 rc = -EINVAL;
2641 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2642 if (!nlbl_ctx) {
2643 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2644 __func__, nlbl_sid);
2645 goto out;
2646 }
2647 rc = -EINVAL;
2648 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2649 if (!xfrm_ctx) {
2650 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2651 __func__, xfrm_sid);
2652 goto out;
2653 }
2654 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2655 if (rc)
2656 goto out;
2657
2658 /* at present NetLabel SIDs/labels really only carry MLS
2659 * information so if the MLS portion of the NetLabel SID
2660 * matches the MLS portion of the labeled XFRM SID/label
2661 * then pass along the XFRM SID as it is the most
2662 * expressive */
2663 *peer_sid = xfrm_sid;
2664 out:
2665 read_unlock(&policy_rwlock);
2666 return rc;
2667 }
2668
2669 static int get_classes_callback(void *k, void *d, void *args)
2670 {
2671 struct class_datum *datum = d;
2672 char *name = k, **classes = args;
2673 int value = datum->value - 1;
2674
2675 classes[value] = kstrdup(name, GFP_ATOMIC);
2676 if (!classes[value])
2677 return -ENOMEM;
2678
2679 return 0;
2680 }
2681
2682 int security_get_classes(char ***classes, int *nclasses)
2683 {
2684 int rc;
2685
2686 read_lock(&policy_rwlock);
2687
2688 rc = -ENOMEM;
2689 *nclasses = policydb.p_classes.nprim;
2690 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2691 if (!*classes)
2692 goto out;
2693
2694 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2695 *classes);
2696 if (rc) {
2697 int i;
2698 for (i = 0; i < *nclasses; i++)
2699 kfree((*classes)[i]);
2700 kfree(*classes);
2701 }
2702
2703 out:
2704 read_unlock(&policy_rwlock);
2705 return rc;
2706 }
2707
2708 static int get_permissions_callback(void *k, void *d, void *args)
2709 {
2710 struct perm_datum *datum = d;
2711 char *name = k, **perms = args;
2712 int value = datum->value - 1;
2713
2714 perms[value] = kstrdup(name, GFP_ATOMIC);
2715 if (!perms[value])
2716 return -ENOMEM;
2717
2718 return 0;
2719 }
2720
2721 int security_get_permissions(char *class, char ***perms, int *nperms)
2722 {
2723 int rc, i;
2724 struct class_datum *match;
2725
2726 read_lock(&policy_rwlock);
2727
2728 rc = -EINVAL;
2729 match = hashtab_search(policydb.p_classes.table, class);
2730 if (!match) {
2731 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2732 __func__, class);
2733 goto out;
2734 }
2735
2736 rc = -ENOMEM;
2737 *nperms = match->permissions.nprim;
2738 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2739 if (!*perms)
2740 goto out;
2741
2742 if (match->comdatum) {
2743 rc = hashtab_map(match->comdatum->permissions.table,
2744 get_permissions_callback, *perms);
2745 if (rc)
2746 goto err;
2747 }
2748
2749 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2750 *perms);
2751 if (rc)
2752 goto err;
2753
2754 out:
2755 read_unlock(&policy_rwlock);
2756 return rc;
2757
2758 err:
2759 read_unlock(&policy_rwlock);
2760 for (i = 0; i < *nperms; i++)
2761 kfree((*perms)[i]);
2762 kfree(*perms);
2763 return rc;
2764 }
2765
2766 int security_get_reject_unknown(void)
2767 {
2768 return policydb.reject_unknown;
2769 }
2770
2771 int security_get_allow_unknown(void)
2772 {
2773 return policydb.allow_unknown;
2774 }
2775
2776 /**
2777 * security_policycap_supported - Check for a specific policy capability
2778 * @req_cap: capability
2779 *
2780 * Description:
2781 * This function queries the currently loaded policy to see if it supports the
2782 * capability specified by @req_cap. Returns true (1) if the capability is
2783 * supported, false (0) if it isn't supported.
2784 *
2785 */
2786 int security_policycap_supported(unsigned int req_cap)
2787 {
2788 int rc;
2789
2790 read_lock(&policy_rwlock);
2791 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2792 read_unlock(&policy_rwlock);
2793
2794 return rc;
2795 }
2796
2797 struct selinux_audit_rule {
2798 u32 au_seqno;
2799 struct context au_ctxt;
2800 };
2801
2802 void selinux_audit_rule_free(void *vrule)
2803 {
2804 struct selinux_audit_rule *rule = vrule;
2805
2806 if (rule) {
2807 context_destroy(&rule->au_ctxt);
2808 kfree(rule);
2809 }
2810 }
2811
2812 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2813 {
2814 struct selinux_audit_rule *tmprule;
2815 struct role_datum *roledatum;
2816 struct type_datum *typedatum;
2817 struct user_datum *userdatum;
2818 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2819 int rc = 0;
2820
2821 *rule = NULL;
2822
2823 if (!ss_initialized)
2824 return -EOPNOTSUPP;
2825
2826 switch (field) {
2827 case AUDIT_SUBJ_USER:
2828 case AUDIT_SUBJ_ROLE:
2829 case AUDIT_SUBJ_TYPE:
2830 case AUDIT_OBJ_USER:
2831 case AUDIT_OBJ_ROLE:
2832 case AUDIT_OBJ_TYPE:
2833 /* only 'equals' and 'not equals' fit user, role, and type */
2834 if (op != Audit_equal && op != Audit_not_equal)
2835 return -EINVAL;
2836 break;
2837 case AUDIT_SUBJ_SEN:
2838 case AUDIT_SUBJ_CLR:
2839 case AUDIT_OBJ_LEV_LOW:
2840 case AUDIT_OBJ_LEV_HIGH:
2841 /* we do not allow a range, indicated by the presence of '-' */
2842 if (strchr(rulestr, '-'))
2843 return -EINVAL;
2844 break;
2845 default:
2846 /* only the above fields are valid */
2847 return -EINVAL;
2848 }
2849
2850 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2851 if (!tmprule)
2852 return -ENOMEM;
2853
2854 context_init(&tmprule->au_ctxt);
2855
2856 read_lock(&policy_rwlock);
2857
2858 tmprule->au_seqno = latest_granting;
2859
2860 switch (field) {
2861 case AUDIT_SUBJ_USER:
2862 case AUDIT_OBJ_USER:
2863 rc = -EINVAL;
2864 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2865 if (!userdatum)
2866 goto out;
2867 tmprule->au_ctxt.user = userdatum->value;
2868 break;
2869 case AUDIT_SUBJ_ROLE:
2870 case AUDIT_OBJ_ROLE:
2871 rc = -EINVAL;
2872 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2873 if (!roledatum)
2874 goto out;
2875 tmprule->au_ctxt.role = roledatum->value;
2876 break;
2877 case AUDIT_SUBJ_TYPE:
2878 case AUDIT_OBJ_TYPE:
2879 rc = -EINVAL;
2880 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2881 if (!typedatum)
2882 goto out;
2883 tmprule->au_ctxt.type = typedatum->value;
2884 break;
2885 case AUDIT_SUBJ_SEN:
2886 case AUDIT_SUBJ_CLR:
2887 case AUDIT_OBJ_LEV_LOW:
2888 case AUDIT_OBJ_LEV_HIGH:
2889 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2890 if (rc)
2891 goto out;
2892 break;
2893 }
2894 rc = 0;
2895 out:
2896 read_unlock(&policy_rwlock);
2897
2898 if (rc) {
2899 selinux_audit_rule_free(tmprule);
2900 tmprule = NULL;
2901 }
2902
2903 *rule = tmprule;
2904
2905 return rc;
2906 }
2907
2908 /* Check to see if the rule contains any selinux fields */
2909 int selinux_audit_rule_known(struct audit_krule *rule)
2910 {
2911 int i;
2912
2913 for (i = 0; i < rule->field_count; i++) {
2914 struct audit_field *f = &rule->fields[i];
2915 switch (f->type) {
2916 case AUDIT_SUBJ_USER:
2917 case AUDIT_SUBJ_ROLE:
2918 case AUDIT_SUBJ_TYPE:
2919 case AUDIT_SUBJ_SEN:
2920 case AUDIT_SUBJ_CLR:
2921 case AUDIT_OBJ_USER:
2922 case AUDIT_OBJ_ROLE:
2923 case AUDIT_OBJ_TYPE:
2924 case AUDIT_OBJ_LEV_LOW:
2925 case AUDIT_OBJ_LEV_HIGH:
2926 return 1;
2927 }
2928 }
2929
2930 return 0;
2931 }
2932
2933 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2934 struct audit_context *actx)
2935 {
2936 struct context *ctxt;
2937 struct mls_level *level;
2938 struct selinux_audit_rule *rule = vrule;
2939 int match = 0;
2940
2941 if (unlikely(!rule)) {
2942 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
2943 return -ENOENT;
2944 }
2945
2946 read_lock(&policy_rwlock);
2947
2948 if (rule->au_seqno < latest_granting) {
2949 match = -ESTALE;
2950 goto out;
2951 }
2952
2953 ctxt = sidtab_search(&sidtab, sid);
2954 if (unlikely(!ctxt)) {
2955 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
2956 sid);
2957 match = -ENOENT;
2958 goto out;
2959 }
2960
2961 /* a field/op pair that is not caught here will simply fall through
2962 without a match */
2963 switch (field) {
2964 case AUDIT_SUBJ_USER:
2965 case AUDIT_OBJ_USER:
2966 switch (op) {
2967 case Audit_equal:
2968 match = (ctxt->user == rule->au_ctxt.user);
2969 break;
2970 case Audit_not_equal:
2971 match = (ctxt->user != rule->au_ctxt.user);
2972 break;
2973 }
2974 break;
2975 case AUDIT_SUBJ_ROLE:
2976 case AUDIT_OBJ_ROLE:
2977 switch (op) {
2978 case Audit_equal:
2979 match = (ctxt->role == rule->au_ctxt.role);
2980 break;
2981 case Audit_not_equal:
2982 match = (ctxt->role != rule->au_ctxt.role);
2983 break;
2984 }
2985 break;
2986 case AUDIT_SUBJ_TYPE:
2987 case AUDIT_OBJ_TYPE:
2988 switch (op) {
2989 case Audit_equal:
2990 match = (ctxt->type == rule->au_ctxt.type);
2991 break;
2992 case Audit_not_equal:
2993 match = (ctxt->type != rule->au_ctxt.type);
2994 break;
2995 }
2996 break;
2997 case AUDIT_SUBJ_SEN:
2998 case AUDIT_SUBJ_CLR:
2999 case AUDIT_OBJ_LEV_LOW:
3000 case AUDIT_OBJ_LEV_HIGH:
3001 level = ((field == AUDIT_SUBJ_SEN ||
3002 field == AUDIT_OBJ_LEV_LOW) ?
3003 &ctxt->range.level[0] : &ctxt->range.level[1]);
3004 switch (op) {
3005 case Audit_equal:
3006 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3007 level);
3008 break;
3009 case Audit_not_equal:
3010 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3011 level);
3012 break;
3013 case Audit_lt:
3014 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3015 level) &&
3016 !mls_level_eq(&rule->au_ctxt.range.level[0],
3017 level));
3018 break;
3019 case Audit_le:
3020 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3021 level);
3022 break;
3023 case Audit_gt:
3024 match = (mls_level_dom(level,
3025 &rule->au_ctxt.range.level[0]) &&
3026 !mls_level_eq(level,
3027 &rule->au_ctxt.range.level[0]));
3028 break;
3029 case Audit_ge:
3030 match = mls_level_dom(level,
3031 &rule->au_ctxt.range.level[0]);
3032 break;
3033 }
3034 }
3035
3036 out:
3037 read_unlock(&policy_rwlock);
3038 return match;
3039 }
3040
3041 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3042
3043 static int aurule_avc_callback(u32 event)
3044 {
3045 int err = 0;
3046
3047 if (event == AVC_CALLBACK_RESET && aurule_callback)
3048 err = aurule_callback();
3049 return err;
3050 }
3051
3052 static int __init aurule_init(void)
3053 {
3054 int err;
3055
3056 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3057 if (err)
3058 panic("avc_add_callback() failed, error %d\n", err);
3059
3060 return err;
3061 }
3062 __initcall(aurule_init);
3063
3064 #ifdef CONFIG_NETLABEL
3065 /**
3066 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3067 * @secattr: the NetLabel packet security attributes
3068 * @sid: the SELinux SID
3069 *
3070 * Description:
3071 * Attempt to cache the context in @ctx, which was derived from the packet in
3072 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3073 * already been initialized.
3074 *
3075 */
3076 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3077 u32 sid)
3078 {
3079 u32 *sid_cache;
3080
3081 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3082 if (sid_cache == NULL)
3083 return;
3084 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3085 if (secattr->cache == NULL) {
3086 kfree(sid_cache);
3087 return;
3088 }
3089
3090 *sid_cache = sid;
3091 secattr->cache->free = kfree;
3092 secattr->cache->data = sid_cache;
3093 secattr->flags |= NETLBL_SECATTR_CACHE;
3094 }
3095
3096 /**
3097 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3098 * @secattr: the NetLabel packet security attributes
3099 * @sid: the SELinux SID
3100 *
3101 * Description:
3102 * Convert the given NetLabel security attributes in @secattr into a
3103 * SELinux SID. If the @secattr field does not contain a full SELinux
3104 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3105 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3106 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3107 * conversion for future lookups. Returns zero on success, negative values on
3108 * failure.
3109 *
3110 */
3111 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3112 u32 *sid)
3113 {
3114 int rc;
3115 struct context *ctx;
3116 struct context ctx_new;
3117
3118 if (!ss_initialized) {
3119 *sid = SECSID_NULL;
3120 return 0;
3121 }
3122
3123 read_lock(&policy_rwlock);
3124
3125 if (secattr->flags & NETLBL_SECATTR_CACHE)
3126 *sid = *(u32 *)secattr->cache->data;
3127 else if (secattr->flags & NETLBL_SECATTR_SECID)
3128 *sid = secattr->attr.secid;
3129 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3130 rc = -EIDRM;
3131 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3132 if (ctx == NULL)
3133 goto out;
3134
3135 context_init(&ctx_new);
3136 ctx_new.user = ctx->user;
3137 ctx_new.role = ctx->role;
3138 ctx_new.type = ctx->type;
3139 mls_import_netlbl_lvl(&ctx_new, secattr);
3140 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3141 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3142 secattr->attr.mls.cat);
3143 if (rc)
3144 goto out;
3145 memcpy(&ctx_new.range.level[1].cat,
3146 &ctx_new.range.level[0].cat,
3147 sizeof(ctx_new.range.level[0].cat));
3148 }
3149 rc = -EIDRM;
3150 if (!mls_context_isvalid(&policydb, &ctx_new))
3151 goto out_free;
3152
3153 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3154 if (rc)
3155 goto out_free;
3156
3157 security_netlbl_cache_add(secattr, *sid);
3158
3159 ebitmap_destroy(&ctx_new.range.level[0].cat);
3160 } else
3161 *sid = SECSID_NULL;
3162
3163 read_unlock(&policy_rwlock);
3164 return 0;
3165 out_free:
3166 ebitmap_destroy(&ctx_new.range.level[0].cat);
3167 out:
3168 read_unlock(&policy_rwlock);
3169 return rc;
3170 }
3171
3172 /**
3173 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3174 * @sid: the SELinux SID
3175 * @secattr: the NetLabel packet security attributes
3176 *
3177 * Description:
3178 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3179 * Returns zero on success, negative values on failure.
3180 *
3181 */
3182 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3183 {
3184 int rc;
3185 struct context *ctx;
3186
3187 if (!ss_initialized)
3188 return 0;
3189
3190 read_lock(&policy_rwlock);
3191
3192 rc = -ENOENT;
3193 ctx = sidtab_search(&sidtab, sid);
3194 if (ctx == NULL)
3195 goto out;
3196
3197 rc = -ENOMEM;
3198 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3199 GFP_ATOMIC);
3200 if (secattr->domain == NULL)
3201 goto out;
3202
3203 secattr->attr.secid = sid;
3204 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3205 mls_export_netlbl_lvl(ctx, secattr);
3206 rc = mls_export_netlbl_cat(ctx, secattr);
3207 out:
3208 read_unlock(&policy_rwlock);
3209 return rc;
3210 }
3211 #endif /* CONFIG_NETLABEL */
3212
3213 /**
3214 * security_read_policy - read the policy.
3215 * @data: binary policy data
3216 * @len: length of data in bytes
3217 *
3218 */
3219 int security_read_policy(void **data, size_t *len)
3220 {
3221 int rc;
3222 struct policy_file fp;
3223
3224 if (!ss_initialized)
3225 return -EINVAL;
3226
3227 *len = security_policydb_len();
3228
3229 *data = vmalloc_user(*len);
3230 if (!*data)
3231 return -ENOMEM;
3232
3233 fp.data = *data;
3234 fp.len = *len;
3235
3236 read_lock(&policy_rwlock);
3237 rc = policydb_write(&policydb, &fp);
3238 read_unlock(&policy_rwlock);
3239
3240 if (rc)
3241 return rc;
3242
3243 *len = (unsigned long)fp.data - (unsigned long)*data;
3244 return 0;
3245
3246 }
Ubuntu Artful kernel mirror