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ima: extend the measurement entry specific pcr
[deliverable/linux.git] / security / selinux / ss / services.c
1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76
77 static DEFINE_RWLOCK(policy_rwlock);
78
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82
83 /*
84 * The largest sequence number that has been used when
85 * providing an access decision to the access vector cache.
86 * The sequence number only changes when a policy change
87 * occurs.
88 */
89 static u32 latest_granting;
90
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 u32 *scontext_len);
94
95 static void context_struct_compute_av(struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd,
99 struct extended_perms *xperms);
100
101 struct selinux_mapping {
102 u16 value; /* policy value */
103 unsigned num_perms;
104 u32 perms[sizeof(u32) * 8];
105 };
106
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109
110 static int selinux_set_mapping(struct policydb *pol,
111 struct security_class_mapping *map,
112 struct selinux_mapping **out_map_p,
113 u16 *out_map_size)
114 {
115 struct selinux_mapping *out_map = NULL;
116 size_t size = sizeof(struct selinux_mapping);
117 u16 i, j;
118 unsigned k;
119 bool print_unknown_handle = false;
120
121 /* Find number of classes in the input mapping */
122 if (!map)
123 return -EINVAL;
124 i = 0;
125 while (map[i].name)
126 i++;
127
128 /* Allocate space for the class records, plus one for class zero */
129 out_map = kcalloc(++i, size, GFP_ATOMIC);
130 if (!out_map)
131 return -ENOMEM;
132
133 /* Store the raw class and permission values */
134 j = 0;
135 while (map[j].name) {
136 struct security_class_mapping *p_in = map + (j++);
137 struct selinux_mapping *p_out = out_map + j;
138
139 /* An empty class string skips ahead */
140 if (!strcmp(p_in->name, "")) {
141 p_out->num_perms = 0;
142 continue;
143 }
144
145 p_out->value = string_to_security_class(pol, p_in->name);
146 if (!p_out->value) {
147 printk(KERN_INFO
148 "SELinux: Class %s not defined in policy.\n",
149 p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 p_out->num_perms = 0;
153 print_unknown_handle = true;
154 continue;
155 }
156
157 k = 0;
158 while (p_in->perms && p_in->perms[k]) {
159 /* An empty permission string skips ahead */
160 if (!*p_in->perms[k]) {
161 k++;
162 continue;
163 }
164 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 p_in->perms[k]);
166 if (!p_out->perms[k]) {
167 printk(KERN_INFO
168 "SELinux: Permission %s in class %s not defined in policy.\n",
169 p_in->perms[k], p_in->name);
170 if (pol->reject_unknown)
171 goto err;
172 print_unknown_handle = true;
173 }
174
175 k++;
176 }
177 p_out->num_perms = k;
178 }
179
180 if (print_unknown_handle)
181 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 pol->allow_unknown ? "allowed" : "denied");
183
184 *out_map_p = out_map;
185 *out_map_size = i;
186 return 0;
187 err:
188 kfree(out_map);
189 return -EINVAL;
190 }
191
192 /*
193 * Get real, policy values from mapped values
194 */
195
196 static u16 unmap_class(u16 tclass)
197 {
198 if (tclass < current_mapping_size)
199 return current_mapping[tclass].value;
200
201 return tclass;
202 }
203
204 /*
205 * Get kernel value for class from its policy value
206 */
207 static u16 map_class(u16 pol_value)
208 {
209 u16 i;
210
211 for (i = 1; i < current_mapping_size; i++) {
212 if (current_mapping[i].value == pol_value)
213 return i;
214 }
215
216 return SECCLASS_NULL;
217 }
218
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 int allow_unknown)
221 {
222 if (tclass < current_mapping_size) {
223 unsigned i, n = current_mapping[tclass].num_perms;
224 u32 result;
225
226 for (i = 0, result = 0; i < n; i++) {
227 if (avd->allowed & current_mapping[tclass].perms[i])
228 result |= 1<<i;
229 if (allow_unknown && !current_mapping[tclass].perms[i])
230 result |= 1<<i;
231 }
232 avd->allowed = result;
233
234 for (i = 0, result = 0; i < n; i++)
235 if (avd->auditallow & current_mapping[tclass].perms[i])
236 result |= 1<<i;
237 avd->auditallow = result;
238
239 for (i = 0, result = 0; i < n; i++) {
240 if (avd->auditdeny & current_mapping[tclass].perms[i])
241 result |= 1<<i;
242 if (!allow_unknown && !current_mapping[tclass].perms[i])
243 result |= 1<<i;
244 }
245 /*
246 * In case the kernel has a bug and requests a permission
247 * between num_perms and the maximum permission number, we
248 * should audit that denial
249 */
250 for (; i < (sizeof(u32)*8); i++)
251 result |= 1<<i;
252 avd->auditdeny = result;
253 }
254 }
255
256 int security_mls_enabled(void)
257 {
258 return policydb.mls_enabled;
259 }
260
261 /*
262 * Return the boolean value of a constraint expression
263 * when it is applied to the specified source and target
264 * security contexts.
265 *
266 * xcontext is a special beast... It is used by the validatetrans rules
267 * only. For these rules, scontext is the context before the transition,
268 * tcontext is the context after the transition, and xcontext is the context
269 * of the process performing the transition. All other callers of
270 * constraint_expr_eval should pass in NULL for xcontext.
271 */
272 static int constraint_expr_eval(struct context *scontext,
273 struct context *tcontext,
274 struct context *xcontext,
275 struct constraint_expr *cexpr)
276 {
277 u32 val1, val2;
278 struct context *c;
279 struct role_datum *r1, *r2;
280 struct mls_level *l1, *l2;
281 struct constraint_expr *e;
282 int s[CEXPR_MAXDEPTH];
283 int sp = -1;
284
285 for (e = cexpr; e; e = e->next) {
286 switch (e->expr_type) {
287 case CEXPR_NOT:
288 BUG_ON(sp < 0);
289 s[sp] = !s[sp];
290 break;
291 case CEXPR_AND:
292 BUG_ON(sp < 1);
293 sp--;
294 s[sp] &= s[sp + 1];
295 break;
296 case CEXPR_OR:
297 BUG_ON(sp < 1);
298 sp--;
299 s[sp] |= s[sp + 1];
300 break;
301 case CEXPR_ATTR:
302 if (sp == (CEXPR_MAXDEPTH - 1))
303 return 0;
304 switch (e->attr) {
305 case CEXPR_USER:
306 val1 = scontext->user;
307 val2 = tcontext->user;
308 break;
309 case CEXPR_TYPE:
310 val1 = scontext->type;
311 val2 = tcontext->type;
312 break;
313 case CEXPR_ROLE:
314 val1 = scontext->role;
315 val2 = tcontext->role;
316 r1 = policydb.role_val_to_struct[val1 - 1];
317 r2 = policydb.role_val_to_struct[val2 - 1];
318 switch (e->op) {
319 case CEXPR_DOM:
320 s[++sp] = ebitmap_get_bit(&r1->dominates,
321 val2 - 1);
322 continue;
323 case CEXPR_DOMBY:
324 s[++sp] = ebitmap_get_bit(&r2->dominates,
325 val1 - 1);
326 continue;
327 case CEXPR_INCOMP:
328 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 val2 - 1) &&
330 !ebitmap_get_bit(&r2->dominates,
331 val1 - 1));
332 continue;
333 default:
334 break;
335 }
336 break;
337 case CEXPR_L1L2:
338 l1 = &(scontext->range.level[0]);
339 l2 = &(tcontext->range.level[0]);
340 goto mls_ops;
341 case CEXPR_L1H2:
342 l1 = &(scontext->range.level[0]);
343 l2 = &(tcontext->range.level[1]);
344 goto mls_ops;
345 case CEXPR_H1L2:
346 l1 = &(scontext->range.level[1]);
347 l2 = &(tcontext->range.level[0]);
348 goto mls_ops;
349 case CEXPR_H1H2:
350 l1 = &(scontext->range.level[1]);
351 l2 = &(tcontext->range.level[1]);
352 goto mls_ops;
353 case CEXPR_L1H1:
354 l1 = &(scontext->range.level[0]);
355 l2 = &(scontext->range.level[1]);
356 goto mls_ops;
357 case CEXPR_L2H2:
358 l1 = &(tcontext->range.level[0]);
359 l2 = &(tcontext->range.level[1]);
360 goto mls_ops;
361 mls_ops:
362 switch (e->op) {
363 case CEXPR_EQ:
364 s[++sp] = mls_level_eq(l1, l2);
365 continue;
366 case CEXPR_NEQ:
367 s[++sp] = !mls_level_eq(l1, l2);
368 continue;
369 case CEXPR_DOM:
370 s[++sp] = mls_level_dom(l1, l2);
371 continue;
372 case CEXPR_DOMBY:
373 s[++sp] = mls_level_dom(l2, l1);
374 continue;
375 case CEXPR_INCOMP:
376 s[++sp] = mls_level_incomp(l2, l1);
377 continue;
378 default:
379 BUG();
380 return 0;
381 }
382 break;
383 default:
384 BUG();
385 return 0;
386 }
387
388 switch (e->op) {
389 case CEXPR_EQ:
390 s[++sp] = (val1 == val2);
391 break;
392 case CEXPR_NEQ:
393 s[++sp] = (val1 != val2);
394 break;
395 default:
396 BUG();
397 return 0;
398 }
399 break;
400 case CEXPR_NAMES:
401 if (sp == (CEXPR_MAXDEPTH-1))
402 return 0;
403 c = scontext;
404 if (e->attr & CEXPR_TARGET)
405 c = tcontext;
406 else if (e->attr & CEXPR_XTARGET) {
407 c = xcontext;
408 if (!c) {
409 BUG();
410 return 0;
411 }
412 }
413 if (e->attr & CEXPR_USER)
414 val1 = c->user;
415 else if (e->attr & CEXPR_ROLE)
416 val1 = c->role;
417 else if (e->attr & CEXPR_TYPE)
418 val1 = c->type;
419 else {
420 BUG();
421 return 0;
422 }
423
424 switch (e->op) {
425 case CEXPR_EQ:
426 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 break;
428 case CEXPR_NEQ:
429 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 break;
431 default:
432 BUG();
433 return 0;
434 }
435 break;
436 default:
437 BUG();
438 return 0;
439 }
440 }
441
442 BUG_ON(sp != 0);
443 return s[0];
444 }
445
446 /*
447 * security_dump_masked_av - dumps masked permissions during
448 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449 */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 struct perm_datum *pdatum = d;
453 char **permission_names = args;
454
455 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456
457 permission_names[pdatum->value - 1] = (char *)k;
458
459 return 0;
460 }
461
462 static void security_dump_masked_av(struct context *scontext,
463 struct context *tcontext,
464 u16 tclass,
465 u32 permissions,
466 const char *reason)
467 {
468 struct common_datum *common_dat;
469 struct class_datum *tclass_dat;
470 struct audit_buffer *ab;
471 char *tclass_name;
472 char *scontext_name = NULL;
473 char *tcontext_name = NULL;
474 char *permission_names[32];
475 int index;
476 u32 length;
477 bool need_comma = false;
478
479 if (!permissions)
480 return;
481
482 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 common_dat = tclass_dat->comdatum;
485
486 /* init permission_names */
487 if (common_dat &&
488 hashtab_map(common_dat->permissions.table,
489 dump_masked_av_helper, permission_names) < 0)
490 goto out;
491
492 if (hashtab_map(tclass_dat->permissions.table,
493 dump_masked_av_helper, permission_names) < 0)
494 goto out;
495
496 /* get scontext/tcontext in text form */
497 if (context_struct_to_string(scontext,
498 &scontext_name, &length) < 0)
499 goto out;
500
501 if (context_struct_to_string(tcontext,
502 &tcontext_name, &length) < 0)
503 goto out;
504
505 /* audit a message */
506 ab = audit_log_start(current->audit_context,
507 GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 if (!ab)
509 goto out;
510
511 audit_log_format(ab, "op=security_compute_av reason=%s "
512 "scontext=%s tcontext=%s tclass=%s perms=",
513 reason, scontext_name, tcontext_name, tclass_name);
514
515 for (index = 0; index < 32; index++) {
516 u32 mask = (1 << index);
517
518 if ((mask & permissions) == 0)
519 continue;
520
521 audit_log_format(ab, "%s%s",
522 need_comma ? "," : "",
523 permission_names[index]
524 ? permission_names[index] : "????");
525 need_comma = true;
526 }
527 audit_log_end(ab);
528 out:
529 /* release scontext/tcontext */
530 kfree(tcontext_name);
531 kfree(scontext_name);
532
533 return;
534 }
535
536 /*
537 * security_boundary_permission - drops violated permissions
538 * on boundary constraint.
539 */
540 static void type_attribute_bounds_av(struct context *scontext,
541 struct context *tcontext,
542 u16 tclass,
543 struct av_decision *avd)
544 {
545 struct context lo_scontext;
546 struct context lo_tcontext;
547 struct av_decision lo_avd;
548 struct type_datum *source;
549 struct type_datum *target;
550 u32 masked = 0;
551
552 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 scontext->type - 1);
554 BUG_ON(!source);
555
556 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557 tcontext->type - 1);
558 BUG_ON(!target);
559
560 if (source->bounds) {
561 memset(&lo_avd, 0, sizeof(lo_avd));
562
563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564 lo_scontext.type = source->bounds;
565
566 context_struct_compute_av(&lo_scontext,
567 tcontext,
568 tclass,
569 &lo_avd,
570 NULL);
571 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
572 return; /* no masked permission */
573 masked = ~lo_avd.allowed & avd->allowed;
574 }
575
576 if (target->bounds) {
577 memset(&lo_avd, 0, sizeof(lo_avd));
578
579 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
580 lo_tcontext.type = target->bounds;
581
582 context_struct_compute_av(scontext,
583 &lo_tcontext,
584 tclass,
585 &lo_avd,
586 NULL);
587 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
588 return; /* no masked permission */
589 masked = ~lo_avd.allowed & avd->allowed;
590 }
591
592 if (source->bounds && target->bounds) {
593 memset(&lo_avd, 0, sizeof(lo_avd));
594 /*
595 * lo_scontext and lo_tcontext are already
596 * set up.
597 */
598
599 context_struct_compute_av(&lo_scontext,
600 &lo_tcontext,
601 tclass,
602 &lo_avd,
603 NULL);
604 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
605 return; /* no masked permission */
606 masked = ~lo_avd.allowed & avd->allowed;
607 }
608
609 if (masked) {
610 /* mask violated permissions */
611 avd->allowed &= ~masked;
612
613 /* audit masked permissions */
614 security_dump_masked_av(scontext, tcontext,
615 tclass, masked, "bounds");
616 }
617 }
618
619 /*
620 * flag which drivers have permissions
621 * only looking for ioctl based extended permssions
622 */
623 void services_compute_xperms_drivers(
624 struct extended_perms *xperms,
625 struct avtab_node *node)
626 {
627 unsigned int i;
628
629 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
630 /* if one or more driver has all permissions allowed */
631 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
632 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
633 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
634 /* if allowing permissions within a driver */
635 security_xperm_set(xperms->drivers.p,
636 node->datum.u.xperms->driver);
637 }
638
639 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
640 if (node->key.specified & AVTAB_XPERMS_ALLOWED)
641 xperms->len = 1;
642 }
643
644 /*
645 * Compute access vectors and extended permissions based on a context
646 * structure pair for the permissions in a particular class.
647 */
648 static void context_struct_compute_av(struct context *scontext,
649 struct context *tcontext,
650 u16 tclass,
651 struct av_decision *avd,
652 struct extended_perms *xperms)
653 {
654 struct constraint_node *constraint;
655 struct role_allow *ra;
656 struct avtab_key avkey;
657 struct avtab_node *node;
658 struct class_datum *tclass_datum;
659 struct ebitmap *sattr, *tattr;
660 struct ebitmap_node *snode, *tnode;
661 unsigned int i, j;
662
663 avd->allowed = 0;
664 avd->auditallow = 0;
665 avd->auditdeny = 0xffffffff;
666 if (xperms) {
667 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
668 xperms->len = 0;
669 }
670
671 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
672 if (printk_ratelimit())
673 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
674 return;
675 }
676
677 tclass_datum = policydb.class_val_to_struct[tclass - 1];
678
679 /*
680 * If a specific type enforcement rule was defined for
681 * this permission check, then use it.
682 */
683 avkey.target_class = tclass;
684 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
685 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
686 BUG_ON(!sattr);
687 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
688 BUG_ON(!tattr);
689 ebitmap_for_each_positive_bit(sattr, snode, i) {
690 ebitmap_for_each_positive_bit(tattr, tnode, j) {
691 avkey.source_type = i + 1;
692 avkey.target_type = j + 1;
693 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
694 node;
695 node = avtab_search_node_next(node, avkey.specified)) {
696 if (node->key.specified == AVTAB_ALLOWED)
697 avd->allowed |= node->datum.u.data;
698 else if (node->key.specified == AVTAB_AUDITALLOW)
699 avd->auditallow |= node->datum.u.data;
700 else if (node->key.specified == AVTAB_AUDITDENY)
701 avd->auditdeny &= node->datum.u.data;
702 else if (xperms && (node->key.specified & AVTAB_XPERMS))
703 services_compute_xperms_drivers(xperms, node);
704 }
705
706 /* Check conditional av table for additional permissions */
707 cond_compute_av(&policydb.te_cond_avtab, &avkey,
708 avd, xperms);
709
710 }
711 }
712
713 /*
714 * Remove any permissions prohibited by a constraint (this includes
715 * the MLS policy).
716 */
717 constraint = tclass_datum->constraints;
718 while (constraint) {
719 if ((constraint->permissions & (avd->allowed)) &&
720 !constraint_expr_eval(scontext, tcontext, NULL,
721 constraint->expr)) {
722 avd->allowed &= ~(constraint->permissions);
723 }
724 constraint = constraint->next;
725 }
726
727 /*
728 * If checking process transition permission and the
729 * role is changing, then check the (current_role, new_role)
730 * pair.
731 */
732 if (tclass == policydb.process_class &&
733 (avd->allowed & policydb.process_trans_perms) &&
734 scontext->role != tcontext->role) {
735 for (ra = policydb.role_allow; ra; ra = ra->next) {
736 if (scontext->role == ra->role &&
737 tcontext->role == ra->new_role)
738 break;
739 }
740 if (!ra)
741 avd->allowed &= ~policydb.process_trans_perms;
742 }
743
744 /*
745 * If the given source and target types have boundary
746 * constraint, lazy checks have to mask any violated
747 * permission and notice it to userspace via audit.
748 */
749 type_attribute_bounds_av(scontext, tcontext,
750 tclass, avd);
751 }
752
753 static int security_validtrans_handle_fail(struct context *ocontext,
754 struct context *ncontext,
755 struct context *tcontext,
756 u16 tclass)
757 {
758 char *o = NULL, *n = NULL, *t = NULL;
759 u32 olen, nlen, tlen;
760
761 if (context_struct_to_string(ocontext, &o, &olen))
762 goto out;
763 if (context_struct_to_string(ncontext, &n, &nlen))
764 goto out;
765 if (context_struct_to_string(tcontext, &t, &tlen))
766 goto out;
767 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
768 "op=security_validate_transition seresult=denied"
769 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
770 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
771 out:
772 kfree(o);
773 kfree(n);
774 kfree(t);
775
776 if (!selinux_enforcing)
777 return 0;
778 return -EPERM;
779 }
780
781 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
782 u16 orig_tclass, bool user)
783 {
784 struct context *ocontext;
785 struct context *ncontext;
786 struct context *tcontext;
787 struct class_datum *tclass_datum;
788 struct constraint_node *constraint;
789 u16 tclass;
790 int rc = 0;
791
792 if (!ss_initialized)
793 return 0;
794
795 read_lock(&policy_rwlock);
796
797 if (!user)
798 tclass = unmap_class(orig_tclass);
799 else
800 tclass = orig_tclass;
801
802 if (!tclass || tclass > policydb.p_classes.nprim) {
803 rc = -EINVAL;
804 goto out;
805 }
806 tclass_datum = policydb.class_val_to_struct[tclass - 1];
807
808 ocontext = sidtab_search(&sidtab, oldsid);
809 if (!ocontext) {
810 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
811 __func__, oldsid);
812 rc = -EINVAL;
813 goto out;
814 }
815
816 ncontext = sidtab_search(&sidtab, newsid);
817 if (!ncontext) {
818 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
819 __func__, newsid);
820 rc = -EINVAL;
821 goto out;
822 }
823
824 tcontext = sidtab_search(&sidtab, tasksid);
825 if (!tcontext) {
826 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
827 __func__, tasksid);
828 rc = -EINVAL;
829 goto out;
830 }
831
832 constraint = tclass_datum->validatetrans;
833 while (constraint) {
834 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
835 constraint->expr)) {
836 if (user)
837 rc = -EPERM;
838 else
839 rc = security_validtrans_handle_fail(ocontext,
840 ncontext,
841 tcontext,
842 tclass);
843 goto out;
844 }
845 constraint = constraint->next;
846 }
847
848 out:
849 read_unlock(&policy_rwlock);
850 return rc;
851 }
852
853 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
854 u16 tclass)
855 {
856 return security_compute_validatetrans(oldsid, newsid, tasksid,
857 tclass, true);
858 }
859
860 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
861 u16 orig_tclass)
862 {
863 return security_compute_validatetrans(oldsid, newsid, tasksid,
864 orig_tclass, false);
865 }
866
867 /*
868 * security_bounded_transition - check whether the given
869 * transition is directed to bounded, or not.
870 * It returns 0, if @newsid is bounded by @oldsid.
871 * Otherwise, it returns error code.
872 *
873 * @oldsid : current security identifier
874 * @newsid : destinated security identifier
875 */
876 int security_bounded_transition(u32 old_sid, u32 new_sid)
877 {
878 struct context *old_context, *new_context;
879 struct type_datum *type;
880 int index;
881 int rc;
882
883 read_lock(&policy_rwlock);
884
885 rc = -EINVAL;
886 old_context = sidtab_search(&sidtab, old_sid);
887 if (!old_context) {
888 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
889 __func__, old_sid);
890 goto out;
891 }
892
893 rc = -EINVAL;
894 new_context = sidtab_search(&sidtab, new_sid);
895 if (!new_context) {
896 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
897 __func__, new_sid);
898 goto out;
899 }
900
901 rc = 0;
902 /* type/domain unchanged */
903 if (old_context->type == new_context->type)
904 goto out;
905
906 index = new_context->type;
907 while (true) {
908 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
909 index - 1);
910 BUG_ON(!type);
911
912 /* not bounded anymore */
913 rc = -EPERM;
914 if (!type->bounds)
915 break;
916
917 /* @newsid is bounded by @oldsid */
918 rc = 0;
919 if (type->bounds == old_context->type)
920 break;
921
922 index = type->bounds;
923 }
924
925 if (rc) {
926 char *old_name = NULL;
927 char *new_name = NULL;
928 u32 length;
929
930 if (!context_struct_to_string(old_context,
931 &old_name, &length) &&
932 !context_struct_to_string(new_context,
933 &new_name, &length)) {
934 audit_log(current->audit_context,
935 GFP_ATOMIC, AUDIT_SELINUX_ERR,
936 "op=security_bounded_transition "
937 "seresult=denied "
938 "oldcontext=%s newcontext=%s",
939 old_name, new_name);
940 }
941 kfree(new_name);
942 kfree(old_name);
943 }
944 out:
945 read_unlock(&policy_rwlock);
946
947 return rc;
948 }
949
950 static void avd_init(struct av_decision *avd)
951 {
952 avd->allowed = 0;
953 avd->auditallow = 0;
954 avd->auditdeny = 0xffffffff;
955 avd->seqno = latest_granting;
956 avd->flags = 0;
957 }
958
959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
960 struct avtab_node *node)
961 {
962 unsigned int i;
963
964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
965 if (xpermd->driver != node->datum.u.xperms->driver)
966 return;
967 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
968 if (!security_xperm_test(node->datum.u.xperms->perms.p,
969 xpermd->driver))
970 return;
971 } else {
972 BUG();
973 }
974
975 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
976 xpermd->used |= XPERMS_ALLOWED;
977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
978 memset(xpermd->allowed->p, 0xff,
979 sizeof(xpermd->allowed->p));
980 }
981 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
982 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
983 xpermd->allowed->p[i] |=
984 node->datum.u.xperms->perms.p[i];
985 }
986 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
987 xpermd->used |= XPERMS_AUDITALLOW;
988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
989 memset(xpermd->auditallow->p, 0xff,
990 sizeof(xpermd->auditallow->p));
991 }
992 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
993 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
994 xpermd->auditallow->p[i] |=
995 node->datum.u.xperms->perms.p[i];
996 }
997 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
998 xpermd->used |= XPERMS_DONTAUDIT;
999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1000 memset(xpermd->dontaudit->p, 0xff,
1001 sizeof(xpermd->dontaudit->p));
1002 }
1003 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1004 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1005 xpermd->dontaudit->p[i] |=
1006 node->datum.u.xperms->perms.p[i];
1007 }
1008 } else {
1009 BUG();
1010 }
1011 }
1012
1013 void security_compute_xperms_decision(u32 ssid,
1014 u32 tsid,
1015 u16 orig_tclass,
1016 u8 driver,
1017 struct extended_perms_decision *xpermd)
1018 {
1019 u16 tclass;
1020 struct context *scontext, *tcontext;
1021 struct avtab_key avkey;
1022 struct avtab_node *node;
1023 struct ebitmap *sattr, *tattr;
1024 struct ebitmap_node *snode, *tnode;
1025 unsigned int i, j;
1026
1027 xpermd->driver = driver;
1028 xpermd->used = 0;
1029 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1030 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1031 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1032
1033 read_lock(&policy_rwlock);
1034 if (!ss_initialized)
1035 goto allow;
1036
1037 scontext = sidtab_search(&sidtab, ssid);
1038 if (!scontext) {
1039 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1040 __func__, ssid);
1041 goto out;
1042 }
1043
1044 tcontext = sidtab_search(&sidtab, tsid);
1045 if (!tcontext) {
1046 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1047 __func__, tsid);
1048 goto out;
1049 }
1050
1051 tclass = unmap_class(orig_tclass);
1052 if (unlikely(orig_tclass && !tclass)) {
1053 if (policydb.allow_unknown)
1054 goto allow;
1055 goto out;
1056 }
1057
1058
1059 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1060 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1061 goto out;
1062 }
1063
1064 avkey.target_class = tclass;
1065 avkey.specified = AVTAB_XPERMS;
1066 sattr = flex_array_get(policydb.type_attr_map_array,
1067 scontext->type - 1);
1068 BUG_ON(!sattr);
1069 tattr = flex_array_get(policydb.type_attr_map_array,
1070 tcontext->type - 1);
1071 BUG_ON(!tattr);
1072 ebitmap_for_each_positive_bit(sattr, snode, i) {
1073 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1074 avkey.source_type = i + 1;
1075 avkey.target_type = j + 1;
1076 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1077 node;
1078 node = avtab_search_node_next(node, avkey.specified))
1079 services_compute_xperms_decision(xpermd, node);
1080
1081 cond_compute_xperms(&policydb.te_cond_avtab,
1082 &avkey, xpermd);
1083 }
1084 }
1085 out:
1086 read_unlock(&policy_rwlock);
1087 return;
1088 allow:
1089 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1090 goto out;
1091 }
1092
1093 /**
1094 * security_compute_av - Compute access vector decisions.
1095 * @ssid: source security identifier
1096 * @tsid: target security identifier
1097 * @tclass: target security class
1098 * @avd: access vector decisions
1099 * @xperms: extended permissions
1100 *
1101 * Compute a set of access vector decisions based on the
1102 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1103 */
1104 void security_compute_av(u32 ssid,
1105 u32 tsid,
1106 u16 orig_tclass,
1107 struct av_decision *avd,
1108 struct extended_perms *xperms)
1109 {
1110 u16 tclass;
1111 struct context *scontext = NULL, *tcontext = NULL;
1112
1113 read_lock(&policy_rwlock);
1114 avd_init(avd);
1115 xperms->len = 0;
1116 if (!ss_initialized)
1117 goto allow;
1118
1119 scontext = sidtab_search(&sidtab, ssid);
1120 if (!scontext) {
1121 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1122 __func__, ssid);
1123 goto out;
1124 }
1125
1126 /* permissive domain? */
1127 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1128 avd->flags |= AVD_FLAGS_PERMISSIVE;
1129
1130 tcontext = sidtab_search(&sidtab, tsid);
1131 if (!tcontext) {
1132 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1133 __func__, tsid);
1134 goto out;
1135 }
1136
1137 tclass = unmap_class(orig_tclass);
1138 if (unlikely(orig_tclass && !tclass)) {
1139 if (policydb.allow_unknown)
1140 goto allow;
1141 goto out;
1142 }
1143 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1144 map_decision(orig_tclass, avd, policydb.allow_unknown);
1145 out:
1146 read_unlock(&policy_rwlock);
1147 return;
1148 allow:
1149 avd->allowed = 0xffffffff;
1150 goto out;
1151 }
1152
1153 void security_compute_av_user(u32 ssid,
1154 u32 tsid,
1155 u16 tclass,
1156 struct av_decision *avd)
1157 {
1158 struct context *scontext = NULL, *tcontext = NULL;
1159
1160 read_lock(&policy_rwlock);
1161 avd_init(avd);
1162 if (!ss_initialized)
1163 goto allow;
1164
1165 scontext = sidtab_search(&sidtab, ssid);
1166 if (!scontext) {
1167 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1168 __func__, ssid);
1169 goto out;
1170 }
1171
1172 /* permissive domain? */
1173 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1174 avd->flags |= AVD_FLAGS_PERMISSIVE;
1175
1176 tcontext = sidtab_search(&sidtab, tsid);
1177 if (!tcontext) {
1178 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1179 __func__, tsid);
1180 goto out;
1181 }
1182
1183 if (unlikely(!tclass)) {
1184 if (policydb.allow_unknown)
1185 goto allow;
1186 goto out;
1187 }
1188
1189 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1190 out:
1191 read_unlock(&policy_rwlock);
1192 return;
1193 allow:
1194 avd->allowed = 0xffffffff;
1195 goto out;
1196 }
1197
1198 /*
1199 * Write the security context string representation of
1200 * the context structure `context' into a dynamically
1201 * allocated string of the correct size. Set `*scontext'
1202 * to point to this string and set `*scontext_len' to
1203 * the length of the string.
1204 */
1205 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1206 {
1207 char *scontextp;
1208
1209 if (scontext)
1210 *scontext = NULL;
1211 *scontext_len = 0;
1212
1213 if (context->len) {
1214 *scontext_len = context->len;
1215 if (scontext) {
1216 *scontext = kstrdup(context->str, GFP_ATOMIC);
1217 if (!(*scontext))
1218 return -ENOMEM;
1219 }
1220 return 0;
1221 }
1222
1223 /* Compute the size of the context. */
1224 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1225 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1226 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1227 *scontext_len += mls_compute_context_len(context);
1228
1229 if (!scontext)
1230 return 0;
1231
1232 /* Allocate space for the context; caller must free this space. */
1233 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1234 if (!scontextp)
1235 return -ENOMEM;
1236 *scontext = scontextp;
1237
1238 /*
1239 * Copy the user name, role name and type name into the context.
1240 */
1241 scontextp += sprintf(scontextp, "%s:%s:%s",
1242 sym_name(&policydb, SYM_USERS, context->user - 1),
1243 sym_name(&policydb, SYM_ROLES, context->role - 1),
1244 sym_name(&policydb, SYM_TYPES, context->type - 1));
1245
1246 mls_sid_to_context(context, &scontextp);
1247
1248 *scontextp = 0;
1249
1250 return 0;
1251 }
1252
1253 #include "initial_sid_to_string.h"
1254
1255 const char *security_get_initial_sid_context(u32 sid)
1256 {
1257 if (unlikely(sid > SECINITSID_NUM))
1258 return NULL;
1259 return initial_sid_to_string[sid];
1260 }
1261
1262 static int security_sid_to_context_core(u32 sid, char **scontext,
1263 u32 *scontext_len, int force)
1264 {
1265 struct context *context;
1266 int rc = 0;
1267
1268 if (scontext)
1269 *scontext = NULL;
1270 *scontext_len = 0;
1271
1272 if (!ss_initialized) {
1273 if (sid <= SECINITSID_NUM) {
1274 char *scontextp;
1275
1276 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1277 if (!scontext)
1278 goto out;
1279 scontextp = kmemdup(initial_sid_to_string[sid],
1280 *scontext_len, GFP_ATOMIC);
1281 if (!scontextp) {
1282 rc = -ENOMEM;
1283 goto out;
1284 }
1285 *scontext = scontextp;
1286 goto out;
1287 }
1288 printk(KERN_ERR "SELinux: %s: called before initial "
1289 "load_policy on unknown SID %d\n", __func__, sid);
1290 rc = -EINVAL;
1291 goto out;
1292 }
1293 read_lock(&policy_rwlock);
1294 if (force)
1295 context = sidtab_search_force(&sidtab, sid);
1296 else
1297 context = sidtab_search(&sidtab, sid);
1298 if (!context) {
1299 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1300 __func__, sid);
1301 rc = -EINVAL;
1302 goto out_unlock;
1303 }
1304 rc = context_struct_to_string(context, scontext, scontext_len);
1305 out_unlock:
1306 read_unlock(&policy_rwlock);
1307 out:
1308 return rc;
1309
1310 }
1311
1312 /**
1313 * security_sid_to_context - Obtain a context for a given SID.
1314 * @sid: security identifier, SID
1315 * @scontext: security context
1316 * @scontext_len: length in bytes
1317 *
1318 * Write the string representation of the context associated with @sid
1319 * into a dynamically allocated string of the correct size. Set @scontext
1320 * to point to this string and set @scontext_len to the length of the string.
1321 */
1322 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1323 {
1324 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1325 }
1326
1327 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1328 {
1329 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1330 }
1331
1332 /*
1333 * Caveat: Mutates scontext.
1334 */
1335 static int string_to_context_struct(struct policydb *pol,
1336 struct sidtab *sidtabp,
1337 char *scontext,
1338 u32 scontext_len,
1339 struct context *ctx,
1340 u32 def_sid)
1341 {
1342 struct role_datum *role;
1343 struct type_datum *typdatum;
1344 struct user_datum *usrdatum;
1345 char *scontextp, *p, oldc;
1346 int rc = 0;
1347
1348 context_init(ctx);
1349
1350 /* Parse the security context. */
1351
1352 rc = -EINVAL;
1353 scontextp = (char *) scontext;
1354
1355 /* Extract the user. */
1356 p = scontextp;
1357 while (*p && *p != ':')
1358 p++;
1359
1360 if (*p == 0)
1361 goto out;
1362
1363 *p++ = 0;
1364
1365 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1366 if (!usrdatum)
1367 goto out;
1368
1369 ctx->user = usrdatum->value;
1370
1371 /* Extract role. */
1372 scontextp = p;
1373 while (*p && *p != ':')
1374 p++;
1375
1376 if (*p == 0)
1377 goto out;
1378
1379 *p++ = 0;
1380
1381 role = hashtab_search(pol->p_roles.table, scontextp);
1382 if (!role)
1383 goto out;
1384 ctx->role = role->value;
1385
1386 /* Extract type. */
1387 scontextp = p;
1388 while (*p && *p != ':')
1389 p++;
1390 oldc = *p;
1391 *p++ = 0;
1392
1393 typdatum = hashtab_search(pol->p_types.table, scontextp);
1394 if (!typdatum || typdatum->attribute)
1395 goto out;
1396
1397 ctx->type = typdatum->value;
1398
1399 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1400 if (rc)
1401 goto out;
1402
1403 rc = -EINVAL;
1404 if ((p - scontext) < scontext_len)
1405 goto out;
1406
1407 /* Check the validity of the new context. */
1408 if (!policydb_context_isvalid(pol, ctx))
1409 goto out;
1410 rc = 0;
1411 out:
1412 if (rc)
1413 context_destroy(ctx);
1414 return rc;
1415 }
1416
1417 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1418 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1419 int force)
1420 {
1421 char *scontext2, *str = NULL;
1422 struct context context;
1423 int rc = 0;
1424
1425 /* An empty security context is never valid. */
1426 if (!scontext_len)
1427 return -EINVAL;
1428
1429 if (!ss_initialized) {
1430 int i;
1431
1432 for (i = 1; i < SECINITSID_NUM; i++) {
1433 if (!strcmp(initial_sid_to_string[i], scontext)) {
1434 *sid = i;
1435 return 0;
1436 }
1437 }
1438 *sid = SECINITSID_KERNEL;
1439 return 0;
1440 }
1441 *sid = SECSID_NULL;
1442
1443 /* Copy the string so that we can modify the copy as we parse it. */
1444 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1445 if (!scontext2)
1446 return -ENOMEM;
1447 memcpy(scontext2, scontext, scontext_len);
1448 scontext2[scontext_len] = 0;
1449
1450 if (force) {
1451 /* Save another copy for storing in uninterpreted form */
1452 rc = -ENOMEM;
1453 str = kstrdup(scontext2, gfp_flags);
1454 if (!str)
1455 goto out;
1456 }
1457
1458 read_lock(&policy_rwlock);
1459 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1460 scontext_len, &context, def_sid);
1461 if (rc == -EINVAL && force) {
1462 context.str = str;
1463 context.len = scontext_len;
1464 str = NULL;
1465 } else if (rc)
1466 goto out_unlock;
1467 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1468 context_destroy(&context);
1469 out_unlock:
1470 read_unlock(&policy_rwlock);
1471 out:
1472 kfree(scontext2);
1473 kfree(str);
1474 return rc;
1475 }
1476
1477 /**
1478 * security_context_to_sid - Obtain a SID for a given security context.
1479 * @scontext: security context
1480 * @scontext_len: length in bytes
1481 * @sid: security identifier, SID
1482 * @gfp: context for the allocation
1483 *
1484 * Obtains a SID associated with the security context that
1485 * has the string representation specified by @scontext.
1486 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1487 * memory is available, or 0 on success.
1488 */
1489 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1490 gfp_t gfp)
1491 {
1492 return security_context_to_sid_core(scontext, scontext_len,
1493 sid, SECSID_NULL, gfp, 0);
1494 }
1495
1496 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1497 {
1498 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1499 }
1500
1501 /**
1502 * security_context_to_sid_default - Obtain a SID for a given security context,
1503 * falling back to specified default if needed.
1504 *
1505 * @scontext: security context
1506 * @scontext_len: length in bytes
1507 * @sid: security identifier, SID
1508 * @def_sid: default SID to assign on error
1509 *
1510 * Obtains a SID associated with the security context that
1511 * has the string representation specified by @scontext.
1512 * The default SID is passed to the MLS layer to be used to allow
1513 * kernel labeling of the MLS field if the MLS field is not present
1514 * (for upgrading to MLS without full relabel).
1515 * Implicitly forces adding of the context even if it cannot be mapped yet.
1516 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1517 * memory is available, or 0 on success.
1518 */
1519 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1520 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1521 {
1522 return security_context_to_sid_core(scontext, scontext_len,
1523 sid, def_sid, gfp_flags, 1);
1524 }
1525
1526 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1527 u32 *sid)
1528 {
1529 return security_context_to_sid_core(scontext, scontext_len,
1530 sid, SECSID_NULL, GFP_KERNEL, 1);
1531 }
1532
1533 static int compute_sid_handle_invalid_context(
1534 struct context *scontext,
1535 struct context *tcontext,
1536 u16 tclass,
1537 struct context *newcontext)
1538 {
1539 char *s = NULL, *t = NULL, *n = NULL;
1540 u32 slen, tlen, nlen;
1541
1542 if (context_struct_to_string(scontext, &s, &slen))
1543 goto out;
1544 if (context_struct_to_string(tcontext, &t, &tlen))
1545 goto out;
1546 if (context_struct_to_string(newcontext, &n, &nlen))
1547 goto out;
1548 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1549 "op=security_compute_sid invalid_context=%s"
1550 " scontext=%s"
1551 " tcontext=%s"
1552 " tclass=%s",
1553 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1554 out:
1555 kfree(s);
1556 kfree(t);
1557 kfree(n);
1558 if (!selinux_enforcing)
1559 return 0;
1560 return -EACCES;
1561 }
1562
1563 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1564 u32 stype, u32 ttype, u16 tclass,
1565 const char *objname)
1566 {
1567 struct filename_trans ft;
1568 struct filename_trans_datum *otype;
1569
1570 /*
1571 * Most filename trans rules are going to live in specific directories
1572 * like /dev or /var/run. This bitmap will quickly skip rule searches
1573 * if the ttype does not contain any rules.
1574 */
1575 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1576 return;
1577
1578 ft.stype = stype;
1579 ft.ttype = ttype;
1580 ft.tclass = tclass;
1581 ft.name = objname;
1582
1583 otype = hashtab_search(p->filename_trans, &ft);
1584 if (otype)
1585 newcontext->type = otype->otype;
1586 }
1587
1588 static int security_compute_sid(u32 ssid,
1589 u32 tsid,
1590 u16 orig_tclass,
1591 u32 specified,
1592 const char *objname,
1593 u32 *out_sid,
1594 bool kern)
1595 {
1596 struct class_datum *cladatum = NULL;
1597 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1598 struct role_trans *roletr = NULL;
1599 struct avtab_key avkey;
1600 struct avtab_datum *avdatum;
1601 struct avtab_node *node;
1602 u16 tclass;
1603 int rc = 0;
1604 bool sock;
1605
1606 if (!ss_initialized) {
1607 switch (orig_tclass) {
1608 case SECCLASS_PROCESS: /* kernel value */
1609 *out_sid = ssid;
1610 break;
1611 default:
1612 *out_sid = tsid;
1613 break;
1614 }
1615 goto out;
1616 }
1617
1618 context_init(&newcontext);
1619
1620 read_lock(&policy_rwlock);
1621
1622 if (kern) {
1623 tclass = unmap_class(orig_tclass);
1624 sock = security_is_socket_class(orig_tclass);
1625 } else {
1626 tclass = orig_tclass;
1627 sock = security_is_socket_class(map_class(tclass));
1628 }
1629
1630 scontext = sidtab_search(&sidtab, ssid);
1631 if (!scontext) {
1632 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1633 __func__, ssid);
1634 rc = -EINVAL;
1635 goto out_unlock;
1636 }
1637 tcontext = sidtab_search(&sidtab, tsid);
1638 if (!tcontext) {
1639 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1640 __func__, tsid);
1641 rc = -EINVAL;
1642 goto out_unlock;
1643 }
1644
1645 if (tclass && tclass <= policydb.p_classes.nprim)
1646 cladatum = policydb.class_val_to_struct[tclass - 1];
1647
1648 /* Set the user identity. */
1649 switch (specified) {
1650 case AVTAB_TRANSITION:
1651 case AVTAB_CHANGE:
1652 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1653 newcontext.user = tcontext->user;
1654 } else {
1655 /* notice this gets both DEFAULT_SOURCE and unset */
1656 /* Use the process user identity. */
1657 newcontext.user = scontext->user;
1658 }
1659 break;
1660 case AVTAB_MEMBER:
1661 /* Use the related object owner. */
1662 newcontext.user = tcontext->user;
1663 break;
1664 }
1665
1666 /* Set the role to default values. */
1667 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1668 newcontext.role = scontext->role;
1669 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1670 newcontext.role = tcontext->role;
1671 } else {
1672 if ((tclass == policydb.process_class) || (sock == true))
1673 newcontext.role = scontext->role;
1674 else
1675 newcontext.role = OBJECT_R_VAL;
1676 }
1677
1678 /* Set the type to default values. */
1679 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1680 newcontext.type = scontext->type;
1681 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1682 newcontext.type = tcontext->type;
1683 } else {
1684 if ((tclass == policydb.process_class) || (sock == true)) {
1685 /* Use the type of process. */
1686 newcontext.type = scontext->type;
1687 } else {
1688 /* Use the type of the related object. */
1689 newcontext.type = tcontext->type;
1690 }
1691 }
1692
1693 /* Look for a type transition/member/change rule. */
1694 avkey.source_type = scontext->type;
1695 avkey.target_type = tcontext->type;
1696 avkey.target_class = tclass;
1697 avkey.specified = specified;
1698 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1699
1700 /* If no permanent rule, also check for enabled conditional rules */
1701 if (!avdatum) {
1702 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1703 for (; node; node = avtab_search_node_next(node, specified)) {
1704 if (node->key.specified & AVTAB_ENABLED) {
1705 avdatum = &node->datum;
1706 break;
1707 }
1708 }
1709 }
1710
1711 if (avdatum) {
1712 /* Use the type from the type transition/member/change rule. */
1713 newcontext.type = avdatum->u.data;
1714 }
1715
1716 /* if we have a objname this is a file trans check so check those rules */
1717 if (objname)
1718 filename_compute_type(&policydb, &newcontext, scontext->type,
1719 tcontext->type, tclass, objname);
1720
1721 /* Check for class-specific changes. */
1722 if (specified & AVTAB_TRANSITION) {
1723 /* Look for a role transition rule. */
1724 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1725 if ((roletr->role == scontext->role) &&
1726 (roletr->type == tcontext->type) &&
1727 (roletr->tclass == tclass)) {
1728 /* Use the role transition rule. */
1729 newcontext.role = roletr->new_role;
1730 break;
1731 }
1732 }
1733 }
1734
1735 /* Set the MLS attributes.
1736 This is done last because it may allocate memory. */
1737 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1738 &newcontext, sock);
1739 if (rc)
1740 goto out_unlock;
1741
1742 /* Check the validity of the context. */
1743 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1744 rc = compute_sid_handle_invalid_context(scontext,
1745 tcontext,
1746 tclass,
1747 &newcontext);
1748 if (rc)
1749 goto out_unlock;
1750 }
1751 /* Obtain the sid for the context. */
1752 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1753 out_unlock:
1754 read_unlock(&policy_rwlock);
1755 context_destroy(&newcontext);
1756 out:
1757 return rc;
1758 }
1759
1760 /**
1761 * security_transition_sid - Compute the SID for a new subject/object.
1762 * @ssid: source security identifier
1763 * @tsid: target security identifier
1764 * @tclass: target security class
1765 * @out_sid: security identifier for new subject/object
1766 *
1767 * Compute a SID to use for labeling a new subject or object in the
1768 * class @tclass based on a SID pair (@ssid, @tsid).
1769 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1770 * if insufficient memory is available, or %0 if the new SID was
1771 * computed successfully.
1772 */
1773 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1774 const struct qstr *qstr, u32 *out_sid)
1775 {
1776 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1777 qstr ? qstr->name : NULL, out_sid, true);
1778 }
1779
1780 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1781 const char *objname, u32 *out_sid)
1782 {
1783 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1784 objname, out_sid, false);
1785 }
1786
1787 /**
1788 * security_member_sid - Compute the SID for member selection.
1789 * @ssid: source security identifier
1790 * @tsid: target security identifier
1791 * @tclass: target security class
1792 * @out_sid: security identifier for selected member
1793 *
1794 * Compute a SID to use when selecting a member of a polyinstantiated
1795 * object of class @tclass based on a SID pair (@ssid, @tsid).
1796 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1797 * if insufficient memory is available, or %0 if the SID was
1798 * computed successfully.
1799 */
1800 int security_member_sid(u32 ssid,
1801 u32 tsid,
1802 u16 tclass,
1803 u32 *out_sid)
1804 {
1805 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1806 out_sid, false);
1807 }
1808
1809 /**
1810 * security_change_sid - Compute the SID for object relabeling.
1811 * @ssid: source security identifier
1812 * @tsid: target security identifier
1813 * @tclass: target security class
1814 * @out_sid: security identifier for selected member
1815 *
1816 * Compute a SID to use for relabeling an object of class @tclass
1817 * based on a SID pair (@ssid, @tsid).
1818 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1819 * if insufficient memory is available, or %0 if the SID was
1820 * computed successfully.
1821 */
1822 int security_change_sid(u32 ssid,
1823 u32 tsid,
1824 u16 tclass,
1825 u32 *out_sid)
1826 {
1827 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1828 out_sid, false);
1829 }
1830
1831 /* Clone the SID into the new SID table. */
1832 static int clone_sid(u32 sid,
1833 struct context *context,
1834 void *arg)
1835 {
1836 struct sidtab *s = arg;
1837
1838 if (sid > SECINITSID_NUM)
1839 return sidtab_insert(s, sid, context);
1840 else
1841 return 0;
1842 }
1843
1844 static inline int convert_context_handle_invalid_context(struct context *context)
1845 {
1846 char *s;
1847 u32 len;
1848
1849 if (selinux_enforcing)
1850 return -EINVAL;
1851
1852 if (!context_struct_to_string(context, &s, &len)) {
1853 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1854 kfree(s);
1855 }
1856 return 0;
1857 }
1858
1859 struct convert_context_args {
1860 struct policydb *oldp;
1861 struct policydb *newp;
1862 };
1863
1864 /*
1865 * Convert the values in the security context
1866 * structure `c' from the values specified
1867 * in the policy `p->oldp' to the values specified
1868 * in the policy `p->newp'. Verify that the
1869 * context is valid under the new policy.
1870 */
1871 static int convert_context(u32 key,
1872 struct context *c,
1873 void *p)
1874 {
1875 struct convert_context_args *args;
1876 struct context oldc;
1877 struct ocontext *oc;
1878 struct mls_range *range;
1879 struct role_datum *role;
1880 struct type_datum *typdatum;
1881 struct user_datum *usrdatum;
1882 char *s;
1883 u32 len;
1884 int rc = 0;
1885
1886 if (key <= SECINITSID_NUM)
1887 goto out;
1888
1889 args = p;
1890
1891 if (c->str) {
1892 struct context ctx;
1893
1894 rc = -ENOMEM;
1895 s = kstrdup(c->str, GFP_KERNEL);
1896 if (!s)
1897 goto out;
1898
1899 rc = string_to_context_struct(args->newp, NULL, s,
1900 c->len, &ctx, SECSID_NULL);
1901 kfree(s);
1902 if (!rc) {
1903 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1904 c->str);
1905 /* Replace string with mapped representation. */
1906 kfree(c->str);
1907 memcpy(c, &ctx, sizeof(*c));
1908 goto out;
1909 } else if (rc == -EINVAL) {
1910 /* Retain string representation for later mapping. */
1911 rc = 0;
1912 goto out;
1913 } else {
1914 /* Other error condition, e.g. ENOMEM. */
1915 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1916 c->str, -rc);
1917 goto out;
1918 }
1919 }
1920
1921 rc = context_cpy(&oldc, c);
1922 if (rc)
1923 goto out;
1924
1925 /* Convert the user. */
1926 rc = -EINVAL;
1927 usrdatum = hashtab_search(args->newp->p_users.table,
1928 sym_name(args->oldp, SYM_USERS, c->user - 1));
1929 if (!usrdatum)
1930 goto bad;
1931 c->user = usrdatum->value;
1932
1933 /* Convert the role. */
1934 rc = -EINVAL;
1935 role = hashtab_search(args->newp->p_roles.table,
1936 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1937 if (!role)
1938 goto bad;
1939 c->role = role->value;
1940
1941 /* Convert the type. */
1942 rc = -EINVAL;
1943 typdatum = hashtab_search(args->newp->p_types.table,
1944 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1945 if (!typdatum)
1946 goto bad;
1947 c->type = typdatum->value;
1948
1949 /* Convert the MLS fields if dealing with MLS policies */
1950 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1951 rc = mls_convert_context(args->oldp, args->newp, c);
1952 if (rc)
1953 goto bad;
1954 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1955 /*
1956 * Switching between MLS and non-MLS policy:
1957 * free any storage used by the MLS fields in the
1958 * context for all existing entries in the sidtab.
1959 */
1960 mls_context_destroy(c);
1961 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1962 /*
1963 * Switching between non-MLS and MLS policy:
1964 * ensure that the MLS fields of the context for all
1965 * existing entries in the sidtab are filled in with a
1966 * suitable default value, likely taken from one of the
1967 * initial SIDs.
1968 */
1969 oc = args->newp->ocontexts[OCON_ISID];
1970 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1971 oc = oc->next;
1972 rc = -EINVAL;
1973 if (!oc) {
1974 printk(KERN_ERR "SELinux: unable to look up"
1975 " the initial SIDs list\n");
1976 goto bad;
1977 }
1978 range = &oc->context[0].range;
1979 rc = mls_range_set(c, range);
1980 if (rc)
1981 goto bad;
1982 }
1983
1984 /* Check the validity of the new context. */
1985 if (!policydb_context_isvalid(args->newp, c)) {
1986 rc = convert_context_handle_invalid_context(&oldc);
1987 if (rc)
1988 goto bad;
1989 }
1990
1991 context_destroy(&oldc);
1992
1993 rc = 0;
1994 out:
1995 return rc;
1996 bad:
1997 /* Map old representation to string and save it. */
1998 rc = context_struct_to_string(&oldc, &s, &len);
1999 if (rc)
2000 return rc;
2001 context_destroy(&oldc);
2002 context_destroy(c);
2003 c->str = s;
2004 c->len = len;
2005 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
2006 c->str);
2007 rc = 0;
2008 goto out;
2009 }
2010
2011 static void security_load_policycaps(void)
2012 {
2013 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2014 POLICYDB_CAPABILITY_NETPEER);
2015 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2016 POLICYDB_CAPABILITY_OPENPERM);
2017 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2018 POLICYDB_CAPABILITY_ALWAYSNETWORK);
2019 }
2020
2021 static int security_preserve_bools(struct policydb *p);
2022
2023 /**
2024 * security_load_policy - Load a security policy configuration.
2025 * @data: binary policy data
2026 * @len: length of data in bytes
2027 *
2028 * Load a new set of security policy configuration data,
2029 * validate it and convert the SID table as necessary.
2030 * This function will flush the access vector cache after
2031 * loading the new policy.
2032 */
2033 int security_load_policy(void *data, size_t len)
2034 {
2035 struct policydb *oldpolicydb, *newpolicydb;
2036 struct sidtab oldsidtab, newsidtab;
2037 struct selinux_mapping *oldmap, *map = NULL;
2038 struct convert_context_args args;
2039 u32 seqno;
2040 u16 map_size;
2041 int rc = 0;
2042 struct policy_file file = { data, len }, *fp = &file;
2043
2044 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2045 if (!oldpolicydb) {
2046 rc = -ENOMEM;
2047 goto out;
2048 }
2049 newpolicydb = oldpolicydb + 1;
2050
2051 if (!ss_initialized) {
2052 avtab_cache_init();
2053 rc = policydb_read(&policydb, fp);
2054 if (rc) {
2055 avtab_cache_destroy();
2056 goto out;
2057 }
2058
2059 policydb.len = len;
2060 rc = selinux_set_mapping(&policydb, secclass_map,
2061 &current_mapping,
2062 &current_mapping_size);
2063 if (rc) {
2064 policydb_destroy(&policydb);
2065 avtab_cache_destroy();
2066 goto out;
2067 }
2068
2069 rc = policydb_load_isids(&policydb, &sidtab);
2070 if (rc) {
2071 policydb_destroy(&policydb);
2072 avtab_cache_destroy();
2073 goto out;
2074 }
2075
2076 security_load_policycaps();
2077 ss_initialized = 1;
2078 seqno = ++latest_granting;
2079 selinux_complete_init();
2080 avc_ss_reset(seqno);
2081 selnl_notify_policyload(seqno);
2082 selinux_status_update_policyload(seqno);
2083 selinux_netlbl_cache_invalidate();
2084 selinux_xfrm_notify_policyload();
2085 goto out;
2086 }
2087
2088 #if 0
2089 sidtab_hash_eval(&sidtab, "sids");
2090 #endif
2091
2092 rc = policydb_read(newpolicydb, fp);
2093 if (rc)
2094 goto out;
2095
2096 newpolicydb->len = len;
2097 /* If switching between different policy types, log MLS status */
2098 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2099 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2100 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2101 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2102
2103 rc = policydb_load_isids(newpolicydb, &newsidtab);
2104 if (rc) {
2105 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2106 policydb_destroy(newpolicydb);
2107 goto out;
2108 }
2109
2110 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2111 if (rc)
2112 goto err;
2113
2114 rc = security_preserve_bools(newpolicydb);
2115 if (rc) {
2116 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2117 goto err;
2118 }
2119
2120 /* Clone the SID table. */
2121 sidtab_shutdown(&sidtab);
2122
2123 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2124 if (rc)
2125 goto err;
2126
2127 /*
2128 * Convert the internal representations of contexts
2129 * in the new SID table.
2130 */
2131 args.oldp = &policydb;
2132 args.newp = newpolicydb;
2133 rc = sidtab_map(&newsidtab, convert_context, &args);
2134 if (rc) {
2135 printk(KERN_ERR "SELinux: unable to convert the internal"
2136 " representation of contexts in the new SID"
2137 " table\n");
2138 goto err;
2139 }
2140
2141 /* Save the old policydb and SID table to free later. */
2142 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2143 sidtab_set(&oldsidtab, &sidtab);
2144
2145 /* Install the new policydb and SID table. */
2146 write_lock_irq(&policy_rwlock);
2147 memcpy(&policydb, newpolicydb, sizeof(policydb));
2148 sidtab_set(&sidtab, &newsidtab);
2149 security_load_policycaps();
2150 oldmap = current_mapping;
2151 current_mapping = map;
2152 current_mapping_size = map_size;
2153 seqno = ++latest_granting;
2154 write_unlock_irq(&policy_rwlock);
2155
2156 /* Free the old policydb and SID table. */
2157 policydb_destroy(oldpolicydb);
2158 sidtab_destroy(&oldsidtab);
2159 kfree(oldmap);
2160
2161 avc_ss_reset(seqno);
2162 selnl_notify_policyload(seqno);
2163 selinux_status_update_policyload(seqno);
2164 selinux_netlbl_cache_invalidate();
2165 selinux_xfrm_notify_policyload();
2166
2167 rc = 0;
2168 goto out;
2169
2170 err:
2171 kfree(map);
2172 sidtab_destroy(&newsidtab);
2173 policydb_destroy(newpolicydb);
2174
2175 out:
2176 kfree(oldpolicydb);
2177 return rc;
2178 }
2179
2180 size_t security_policydb_len(void)
2181 {
2182 size_t len;
2183
2184 read_lock(&policy_rwlock);
2185 len = policydb.len;
2186 read_unlock(&policy_rwlock);
2187
2188 return len;
2189 }
2190
2191 /**
2192 * security_port_sid - Obtain the SID for a port.
2193 * @protocol: protocol number
2194 * @port: port number
2195 * @out_sid: security identifier
2196 */
2197 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2198 {
2199 struct ocontext *c;
2200 int rc = 0;
2201
2202 read_lock(&policy_rwlock);
2203
2204 c = policydb.ocontexts[OCON_PORT];
2205 while (c) {
2206 if (c->u.port.protocol == protocol &&
2207 c->u.port.low_port <= port &&
2208 c->u.port.high_port >= port)
2209 break;
2210 c = c->next;
2211 }
2212
2213 if (c) {
2214 if (!c->sid[0]) {
2215 rc = sidtab_context_to_sid(&sidtab,
2216 &c->context[0],
2217 &c->sid[0]);
2218 if (rc)
2219 goto out;
2220 }
2221 *out_sid = c->sid[0];
2222 } else {
2223 *out_sid = SECINITSID_PORT;
2224 }
2225
2226 out:
2227 read_unlock(&policy_rwlock);
2228 return rc;
2229 }
2230
2231 /**
2232 * security_netif_sid - Obtain the SID for a network interface.
2233 * @name: interface name
2234 * @if_sid: interface SID
2235 */
2236 int security_netif_sid(char *name, u32 *if_sid)
2237 {
2238 int rc = 0;
2239 struct ocontext *c;
2240
2241 read_lock(&policy_rwlock);
2242
2243 c = policydb.ocontexts[OCON_NETIF];
2244 while (c) {
2245 if (strcmp(name, c->u.name) == 0)
2246 break;
2247 c = c->next;
2248 }
2249
2250 if (c) {
2251 if (!c->sid[0] || !c->sid[1]) {
2252 rc = sidtab_context_to_sid(&sidtab,
2253 &c->context[0],
2254 &c->sid[0]);
2255 if (rc)
2256 goto out;
2257 rc = sidtab_context_to_sid(&sidtab,
2258 &c->context[1],
2259 &c->sid[1]);
2260 if (rc)
2261 goto out;
2262 }
2263 *if_sid = c->sid[0];
2264 } else
2265 *if_sid = SECINITSID_NETIF;
2266
2267 out:
2268 read_unlock(&policy_rwlock);
2269 return rc;
2270 }
2271
2272 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2273 {
2274 int i, fail = 0;
2275
2276 for (i = 0; i < 4; i++)
2277 if (addr[i] != (input[i] & mask[i])) {
2278 fail = 1;
2279 break;
2280 }
2281
2282 return !fail;
2283 }
2284
2285 /**
2286 * security_node_sid - Obtain the SID for a node (host).
2287 * @domain: communication domain aka address family
2288 * @addrp: address
2289 * @addrlen: address length in bytes
2290 * @out_sid: security identifier
2291 */
2292 int security_node_sid(u16 domain,
2293 void *addrp,
2294 u32 addrlen,
2295 u32 *out_sid)
2296 {
2297 int rc;
2298 struct ocontext *c;
2299
2300 read_lock(&policy_rwlock);
2301
2302 switch (domain) {
2303 case AF_INET: {
2304 u32 addr;
2305
2306 rc = -EINVAL;
2307 if (addrlen != sizeof(u32))
2308 goto out;
2309
2310 addr = *((u32 *)addrp);
2311
2312 c = policydb.ocontexts[OCON_NODE];
2313 while (c) {
2314 if (c->u.node.addr == (addr & c->u.node.mask))
2315 break;
2316 c = c->next;
2317 }
2318 break;
2319 }
2320
2321 case AF_INET6:
2322 rc = -EINVAL;
2323 if (addrlen != sizeof(u64) * 2)
2324 goto out;
2325 c = policydb.ocontexts[OCON_NODE6];
2326 while (c) {
2327 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2328 c->u.node6.mask))
2329 break;
2330 c = c->next;
2331 }
2332 break;
2333
2334 default:
2335 rc = 0;
2336 *out_sid = SECINITSID_NODE;
2337 goto out;
2338 }
2339
2340 if (c) {
2341 if (!c->sid[0]) {
2342 rc = sidtab_context_to_sid(&sidtab,
2343 &c->context[0],
2344 &c->sid[0]);
2345 if (rc)
2346 goto out;
2347 }
2348 *out_sid = c->sid[0];
2349 } else {
2350 *out_sid = SECINITSID_NODE;
2351 }
2352
2353 rc = 0;
2354 out:
2355 read_unlock(&policy_rwlock);
2356 return rc;
2357 }
2358
2359 #define SIDS_NEL 25
2360
2361 /**
2362 * security_get_user_sids - Obtain reachable SIDs for a user.
2363 * @fromsid: starting SID
2364 * @username: username
2365 * @sids: array of reachable SIDs for user
2366 * @nel: number of elements in @sids
2367 *
2368 * Generate the set of SIDs for legal security contexts
2369 * for a given user that can be reached by @fromsid.
2370 * Set *@sids to point to a dynamically allocated
2371 * array containing the set of SIDs. Set *@nel to the
2372 * number of elements in the array.
2373 */
2374
2375 int security_get_user_sids(u32 fromsid,
2376 char *username,
2377 u32 **sids,
2378 u32 *nel)
2379 {
2380 struct context *fromcon, usercon;
2381 u32 *mysids = NULL, *mysids2, sid;
2382 u32 mynel = 0, maxnel = SIDS_NEL;
2383 struct user_datum *user;
2384 struct role_datum *role;
2385 struct ebitmap_node *rnode, *tnode;
2386 int rc = 0, i, j;
2387
2388 *sids = NULL;
2389 *nel = 0;
2390
2391 if (!ss_initialized)
2392 goto out;
2393
2394 read_lock(&policy_rwlock);
2395
2396 context_init(&usercon);
2397
2398 rc = -EINVAL;
2399 fromcon = sidtab_search(&sidtab, fromsid);
2400 if (!fromcon)
2401 goto out_unlock;
2402
2403 rc = -EINVAL;
2404 user = hashtab_search(policydb.p_users.table, username);
2405 if (!user)
2406 goto out_unlock;
2407
2408 usercon.user = user->value;
2409
2410 rc = -ENOMEM;
2411 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2412 if (!mysids)
2413 goto out_unlock;
2414
2415 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2416 role = policydb.role_val_to_struct[i];
2417 usercon.role = i + 1;
2418 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2419 usercon.type = j + 1;
2420
2421 if (mls_setup_user_range(fromcon, user, &usercon))
2422 continue;
2423
2424 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2425 if (rc)
2426 goto out_unlock;
2427 if (mynel < maxnel) {
2428 mysids[mynel++] = sid;
2429 } else {
2430 rc = -ENOMEM;
2431 maxnel += SIDS_NEL;
2432 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2433 if (!mysids2)
2434 goto out_unlock;
2435 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2436 kfree(mysids);
2437 mysids = mysids2;
2438 mysids[mynel++] = sid;
2439 }
2440 }
2441 }
2442 rc = 0;
2443 out_unlock:
2444 read_unlock(&policy_rwlock);
2445 if (rc || !mynel) {
2446 kfree(mysids);
2447 goto out;
2448 }
2449
2450 rc = -ENOMEM;
2451 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2452 if (!mysids2) {
2453 kfree(mysids);
2454 goto out;
2455 }
2456 for (i = 0, j = 0; i < mynel; i++) {
2457 struct av_decision dummy_avd;
2458 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2459 SECCLASS_PROCESS, /* kernel value */
2460 PROCESS__TRANSITION, AVC_STRICT,
2461 &dummy_avd);
2462 if (!rc)
2463 mysids2[j++] = mysids[i];
2464 cond_resched();
2465 }
2466 rc = 0;
2467 kfree(mysids);
2468 *sids = mysids2;
2469 *nel = j;
2470 out:
2471 return rc;
2472 }
2473
2474 /**
2475 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2476 * @fstype: filesystem type
2477 * @path: path from root of mount
2478 * @sclass: file security class
2479 * @sid: SID for path
2480 *
2481 * Obtain a SID to use for a file in a filesystem that
2482 * cannot support xattr or use a fixed labeling behavior like
2483 * transition SIDs or task SIDs.
2484 *
2485 * The caller must acquire the policy_rwlock before calling this function.
2486 */
2487 static inline int __security_genfs_sid(const char *fstype,
2488 char *path,
2489 u16 orig_sclass,
2490 u32 *sid)
2491 {
2492 int len;
2493 u16 sclass;
2494 struct genfs *genfs;
2495 struct ocontext *c;
2496 int rc, cmp = 0;
2497
2498 while (path[0] == '/' && path[1] == '/')
2499 path++;
2500
2501 sclass = unmap_class(orig_sclass);
2502 *sid = SECINITSID_UNLABELED;
2503
2504 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2505 cmp = strcmp(fstype, genfs->fstype);
2506 if (cmp <= 0)
2507 break;
2508 }
2509
2510 rc = -ENOENT;
2511 if (!genfs || cmp)
2512 goto out;
2513
2514 for (c = genfs->head; c; c = c->next) {
2515 len = strlen(c->u.name);
2516 if ((!c->v.sclass || sclass == c->v.sclass) &&
2517 (strncmp(c->u.name, path, len) == 0))
2518 break;
2519 }
2520
2521 rc = -ENOENT;
2522 if (!c)
2523 goto out;
2524
2525 if (!c->sid[0]) {
2526 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2527 if (rc)
2528 goto out;
2529 }
2530
2531 *sid = c->sid[0];
2532 rc = 0;
2533 out:
2534 return rc;
2535 }
2536
2537 /**
2538 * security_genfs_sid - Obtain a SID for a file in a filesystem
2539 * @fstype: filesystem type
2540 * @path: path from root of mount
2541 * @sclass: file security class
2542 * @sid: SID for path
2543 *
2544 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2545 * it afterward.
2546 */
2547 int security_genfs_sid(const char *fstype,
2548 char *path,
2549 u16 orig_sclass,
2550 u32 *sid)
2551 {
2552 int retval;
2553
2554 read_lock(&policy_rwlock);
2555 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2556 read_unlock(&policy_rwlock);
2557 return retval;
2558 }
2559
2560 /**
2561 * security_fs_use - Determine how to handle labeling for a filesystem.
2562 * @sb: superblock in question
2563 */
2564 int security_fs_use(struct super_block *sb)
2565 {
2566 int rc = 0;
2567 struct ocontext *c;
2568 struct superblock_security_struct *sbsec = sb->s_security;
2569 const char *fstype = sb->s_type->name;
2570
2571 read_lock(&policy_rwlock);
2572
2573 c = policydb.ocontexts[OCON_FSUSE];
2574 while (c) {
2575 if (strcmp(fstype, c->u.name) == 0)
2576 break;
2577 c = c->next;
2578 }
2579
2580 if (c) {
2581 sbsec->behavior = c->v.behavior;
2582 if (!c->sid[0]) {
2583 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2584 &c->sid[0]);
2585 if (rc)
2586 goto out;
2587 }
2588 sbsec->sid = c->sid[0];
2589 } else {
2590 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2591 &sbsec->sid);
2592 if (rc) {
2593 sbsec->behavior = SECURITY_FS_USE_NONE;
2594 rc = 0;
2595 } else {
2596 sbsec->behavior = SECURITY_FS_USE_GENFS;
2597 }
2598 }
2599
2600 out:
2601 read_unlock(&policy_rwlock);
2602 return rc;
2603 }
2604
2605 int security_get_bools(int *len, char ***names, int **values)
2606 {
2607 int i, rc;
2608
2609 read_lock(&policy_rwlock);
2610 *names = NULL;
2611 *values = NULL;
2612
2613 rc = 0;
2614 *len = policydb.p_bools.nprim;
2615 if (!*len)
2616 goto out;
2617
2618 rc = -ENOMEM;
2619 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2620 if (!*names)
2621 goto err;
2622
2623 rc = -ENOMEM;
2624 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2625 if (!*values)
2626 goto err;
2627
2628 for (i = 0; i < *len; i++) {
2629 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2630
2631 rc = -ENOMEM;
2632 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2633 if (!(*names)[i])
2634 goto err;
2635 }
2636 rc = 0;
2637 out:
2638 read_unlock(&policy_rwlock);
2639 return rc;
2640 err:
2641 if (*names) {
2642 for (i = 0; i < *len; i++)
2643 kfree((*names)[i]);
2644 }
2645 kfree(*values);
2646 goto out;
2647 }
2648
2649
2650 int security_set_bools(int len, int *values)
2651 {
2652 int i, rc;
2653 int lenp, seqno = 0;
2654 struct cond_node *cur;
2655
2656 write_lock_irq(&policy_rwlock);
2657
2658 rc = -EFAULT;
2659 lenp = policydb.p_bools.nprim;
2660 if (len != lenp)
2661 goto out;
2662
2663 for (i = 0; i < len; i++) {
2664 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2665 audit_log(current->audit_context, GFP_ATOMIC,
2666 AUDIT_MAC_CONFIG_CHANGE,
2667 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2668 sym_name(&policydb, SYM_BOOLS, i),
2669 !!values[i],
2670 policydb.bool_val_to_struct[i]->state,
2671 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2672 audit_get_sessionid(current));
2673 }
2674 if (values[i])
2675 policydb.bool_val_to_struct[i]->state = 1;
2676 else
2677 policydb.bool_val_to_struct[i]->state = 0;
2678 }
2679
2680 for (cur = policydb.cond_list; cur; cur = cur->next) {
2681 rc = evaluate_cond_node(&policydb, cur);
2682 if (rc)
2683 goto out;
2684 }
2685
2686 seqno = ++latest_granting;
2687 rc = 0;
2688 out:
2689 write_unlock_irq(&policy_rwlock);
2690 if (!rc) {
2691 avc_ss_reset(seqno);
2692 selnl_notify_policyload(seqno);
2693 selinux_status_update_policyload(seqno);
2694 selinux_xfrm_notify_policyload();
2695 }
2696 return rc;
2697 }
2698
2699 int security_get_bool_value(int index)
2700 {
2701 int rc;
2702 int len;
2703
2704 read_lock(&policy_rwlock);
2705
2706 rc = -EFAULT;
2707 len = policydb.p_bools.nprim;
2708 if (index >= len)
2709 goto out;
2710
2711 rc = policydb.bool_val_to_struct[index]->state;
2712 out:
2713 read_unlock(&policy_rwlock);
2714 return rc;
2715 }
2716
2717 static int security_preserve_bools(struct policydb *p)
2718 {
2719 int rc, nbools = 0, *bvalues = NULL, i;
2720 char **bnames = NULL;
2721 struct cond_bool_datum *booldatum;
2722 struct cond_node *cur;
2723
2724 rc = security_get_bools(&nbools, &bnames, &bvalues);
2725 if (rc)
2726 goto out;
2727 for (i = 0; i < nbools; i++) {
2728 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2729 if (booldatum)
2730 booldatum->state = bvalues[i];
2731 }
2732 for (cur = p->cond_list; cur; cur = cur->next) {
2733 rc = evaluate_cond_node(p, cur);
2734 if (rc)
2735 goto out;
2736 }
2737
2738 out:
2739 if (bnames) {
2740 for (i = 0; i < nbools; i++)
2741 kfree(bnames[i]);
2742 }
2743 kfree(bnames);
2744 kfree(bvalues);
2745 return rc;
2746 }
2747
2748 /*
2749 * security_sid_mls_copy() - computes a new sid based on the given
2750 * sid and the mls portion of mls_sid.
2751 */
2752 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2753 {
2754 struct context *context1;
2755 struct context *context2;
2756 struct context newcon;
2757 char *s;
2758 u32 len;
2759 int rc;
2760
2761 rc = 0;
2762 if (!ss_initialized || !policydb.mls_enabled) {
2763 *new_sid = sid;
2764 goto out;
2765 }
2766
2767 context_init(&newcon);
2768
2769 read_lock(&policy_rwlock);
2770
2771 rc = -EINVAL;
2772 context1 = sidtab_search(&sidtab, sid);
2773 if (!context1) {
2774 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2775 __func__, sid);
2776 goto out_unlock;
2777 }
2778
2779 rc = -EINVAL;
2780 context2 = sidtab_search(&sidtab, mls_sid);
2781 if (!context2) {
2782 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2783 __func__, mls_sid);
2784 goto out_unlock;
2785 }
2786
2787 newcon.user = context1->user;
2788 newcon.role = context1->role;
2789 newcon.type = context1->type;
2790 rc = mls_context_cpy(&newcon, context2);
2791 if (rc)
2792 goto out_unlock;
2793
2794 /* Check the validity of the new context. */
2795 if (!policydb_context_isvalid(&policydb, &newcon)) {
2796 rc = convert_context_handle_invalid_context(&newcon);
2797 if (rc) {
2798 if (!context_struct_to_string(&newcon, &s, &len)) {
2799 audit_log(current->audit_context,
2800 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2801 "op=security_sid_mls_copy "
2802 "invalid_context=%s", s);
2803 kfree(s);
2804 }
2805 goto out_unlock;
2806 }
2807 }
2808
2809 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2810 out_unlock:
2811 read_unlock(&policy_rwlock);
2812 context_destroy(&newcon);
2813 out:
2814 return rc;
2815 }
2816
2817 /**
2818 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2819 * @nlbl_sid: NetLabel SID
2820 * @nlbl_type: NetLabel labeling protocol type
2821 * @xfrm_sid: XFRM SID
2822 *
2823 * Description:
2824 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2825 * resolved into a single SID it is returned via @peer_sid and the function
2826 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2827 * returns a negative value. A table summarizing the behavior is below:
2828 *
2829 * | function return | @sid
2830 * ------------------------------+-----------------+-----------------
2831 * no peer labels | 0 | SECSID_NULL
2832 * single peer label | 0 | <peer_label>
2833 * multiple, consistent labels | 0 | <peer_label>
2834 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2835 *
2836 */
2837 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2838 u32 xfrm_sid,
2839 u32 *peer_sid)
2840 {
2841 int rc;
2842 struct context *nlbl_ctx;
2843 struct context *xfrm_ctx;
2844
2845 *peer_sid = SECSID_NULL;
2846
2847 /* handle the common (which also happens to be the set of easy) cases
2848 * right away, these two if statements catch everything involving a
2849 * single or absent peer SID/label */
2850 if (xfrm_sid == SECSID_NULL) {
2851 *peer_sid = nlbl_sid;
2852 return 0;
2853 }
2854 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2855 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2856 * is present */
2857 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2858 *peer_sid = xfrm_sid;
2859 return 0;
2860 }
2861
2862 /* we don't need to check ss_initialized here since the only way both
2863 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2864 * security server was initialized and ss_initialized was true */
2865 if (!policydb.mls_enabled)
2866 return 0;
2867
2868 read_lock(&policy_rwlock);
2869
2870 rc = -EINVAL;
2871 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2872 if (!nlbl_ctx) {
2873 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2874 __func__, nlbl_sid);
2875 goto out;
2876 }
2877 rc = -EINVAL;
2878 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2879 if (!xfrm_ctx) {
2880 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2881 __func__, xfrm_sid);
2882 goto out;
2883 }
2884 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2885 if (rc)
2886 goto out;
2887
2888 /* at present NetLabel SIDs/labels really only carry MLS
2889 * information so if the MLS portion of the NetLabel SID
2890 * matches the MLS portion of the labeled XFRM SID/label
2891 * then pass along the XFRM SID as it is the most
2892 * expressive */
2893 *peer_sid = xfrm_sid;
2894 out:
2895 read_unlock(&policy_rwlock);
2896 return rc;
2897 }
2898
2899 static int get_classes_callback(void *k, void *d, void *args)
2900 {
2901 struct class_datum *datum = d;
2902 char *name = k, **classes = args;
2903 int value = datum->value - 1;
2904
2905 classes[value] = kstrdup(name, GFP_ATOMIC);
2906 if (!classes[value])
2907 return -ENOMEM;
2908
2909 return 0;
2910 }
2911
2912 int security_get_classes(char ***classes, int *nclasses)
2913 {
2914 int rc;
2915
2916 read_lock(&policy_rwlock);
2917
2918 rc = -ENOMEM;
2919 *nclasses = policydb.p_classes.nprim;
2920 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2921 if (!*classes)
2922 goto out;
2923
2924 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2925 *classes);
2926 if (rc) {
2927 int i;
2928 for (i = 0; i < *nclasses; i++)
2929 kfree((*classes)[i]);
2930 kfree(*classes);
2931 }
2932
2933 out:
2934 read_unlock(&policy_rwlock);
2935 return rc;
2936 }
2937
2938 static int get_permissions_callback(void *k, void *d, void *args)
2939 {
2940 struct perm_datum *datum = d;
2941 char *name = k, **perms = args;
2942 int value = datum->value - 1;
2943
2944 perms[value] = kstrdup(name, GFP_ATOMIC);
2945 if (!perms[value])
2946 return -ENOMEM;
2947
2948 return 0;
2949 }
2950
2951 int security_get_permissions(char *class, char ***perms, int *nperms)
2952 {
2953 int rc, i;
2954 struct class_datum *match;
2955
2956 read_lock(&policy_rwlock);
2957
2958 rc = -EINVAL;
2959 match = hashtab_search(policydb.p_classes.table, class);
2960 if (!match) {
2961 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2962 __func__, class);
2963 goto out;
2964 }
2965
2966 rc = -ENOMEM;
2967 *nperms = match->permissions.nprim;
2968 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2969 if (!*perms)
2970 goto out;
2971
2972 if (match->comdatum) {
2973 rc = hashtab_map(match->comdatum->permissions.table,
2974 get_permissions_callback, *perms);
2975 if (rc)
2976 goto err;
2977 }
2978
2979 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2980 *perms);
2981 if (rc)
2982 goto err;
2983
2984 out:
2985 read_unlock(&policy_rwlock);
2986 return rc;
2987
2988 err:
2989 read_unlock(&policy_rwlock);
2990 for (i = 0; i < *nperms; i++)
2991 kfree((*perms)[i]);
2992 kfree(*perms);
2993 return rc;
2994 }
2995
2996 int security_get_reject_unknown(void)
2997 {
2998 return policydb.reject_unknown;
2999 }
3000
3001 int security_get_allow_unknown(void)
3002 {
3003 return policydb.allow_unknown;
3004 }
3005
3006 /**
3007 * security_policycap_supported - Check for a specific policy capability
3008 * @req_cap: capability
3009 *
3010 * Description:
3011 * This function queries the currently loaded policy to see if it supports the
3012 * capability specified by @req_cap. Returns true (1) if the capability is
3013 * supported, false (0) if it isn't supported.
3014 *
3015 */
3016 int security_policycap_supported(unsigned int req_cap)
3017 {
3018 int rc;
3019
3020 read_lock(&policy_rwlock);
3021 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3022 read_unlock(&policy_rwlock);
3023
3024 return rc;
3025 }
3026
3027 struct selinux_audit_rule {
3028 u32 au_seqno;
3029 struct context au_ctxt;
3030 };
3031
3032 void selinux_audit_rule_free(void *vrule)
3033 {
3034 struct selinux_audit_rule *rule = vrule;
3035
3036 if (rule) {
3037 context_destroy(&rule->au_ctxt);
3038 kfree(rule);
3039 }
3040 }
3041
3042 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3043 {
3044 struct selinux_audit_rule *tmprule;
3045 struct role_datum *roledatum;
3046 struct type_datum *typedatum;
3047 struct user_datum *userdatum;
3048 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3049 int rc = 0;
3050
3051 *rule = NULL;
3052
3053 if (!ss_initialized)
3054 return -EOPNOTSUPP;
3055
3056 switch (field) {
3057 case AUDIT_SUBJ_USER:
3058 case AUDIT_SUBJ_ROLE:
3059 case AUDIT_SUBJ_TYPE:
3060 case AUDIT_OBJ_USER:
3061 case AUDIT_OBJ_ROLE:
3062 case AUDIT_OBJ_TYPE:
3063 /* only 'equals' and 'not equals' fit user, role, and type */
3064 if (op != Audit_equal && op != Audit_not_equal)
3065 return -EINVAL;
3066 break;
3067 case AUDIT_SUBJ_SEN:
3068 case AUDIT_SUBJ_CLR:
3069 case AUDIT_OBJ_LEV_LOW:
3070 case AUDIT_OBJ_LEV_HIGH:
3071 /* we do not allow a range, indicated by the presence of '-' */
3072 if (strchr(rulestr, '-'))
3073 return -EINVAL;
3074 break;
3075 default:
3076 /* only the above fields are valid */
3077 return -EINVAL;
3078 }
3079
3080 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3081 if (!tmprule)
3082 return -ENOMEM;
3083
3084 context_init(&tmprule->au_ctxt);
3085
3086 read_lock(&policy_rwlock);
3087
3088 tmprule->au_seqno = latest_granting;
3089
3090 switch (field) {
3091 case AUDIT_SUBJ_USER:
3092 case AUDIT_OBJ_USER:
3093 rc = -EINVAL;
3094 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3095 if (!userdatum)
3096 goto out;
3097 tmprule->au_ctxt.user = userdatum->value;
3098 break;
3099 case AUDIT_SUBJ_ROLE:
3100 case AUDIT_OBJ_ROLE:
3101 rc = -EINVAL;
3102 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3103 if (!roledatum)
3104 goto out;
3105 tmprule->au_ctxt.role = roledatum->value;
3106 break;
3107 case AUDIT_SUBJ_TYPE:
3108 case AUDIT_OBJ_TYPE:
3109 rc = -EINVAL;
3110 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3111 if (!typedatum)
3112 goto out;
3113 tmprule->au_ctxt.type = typedatum->value;
3114 break;
3115 case AUDIT_SUBJ_SEN:
3116 case AUDIT_SUBJ_CLR:
3117 case AUDIT_OBJ_LEV_LOW:
3118 case AUDIT_OBJ_LEV_HIGH:
3119 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3120 if (rc)
3121 goto out;
3122 break;
3123 }
3124 rc = 0;
3125 out:
3126 read_unlock(&policy_rwlock);
3127
3128 if (rc) {
3129 selinux_audit_rule_free(tmprule);
3130 tmprule = NULL;
3131 }
3132
3133 *rule = tmprule;
3134
3135 return rc;
3136 }
3137
3138 /* Check to see if the rule contains any selinux fields */
3139 int selinux_audit_rule_known(struct audit_krule *rule)
3140 {
3141 int i;
3142
3143 for (i = 0; i < rule->field_count; i++) {
3144 struct audit_field *f = &rule->fields[i];
3145 switch (f->type) {
3146 case AUDIT_SUBJ_USER:
3147 case AUDIT_SUBJ_ROLE:
3148 case AUDIT_SUBJ_TYPE:
3149 case AUDIT_SUBJ_SEN:
3150 case AUDIT_SUBJ_CLR:
3151 case AUDIT_OBJ_USER:
3152 case AUDIT_OBJ_ROLE:
3153 case AUDIT_OBJ_TYPE:
3154 case AUDIT_OBJ_LEV_LOW:
3155 case AUDIT_OBJ_LEV_HIGH:
3156 return 1;
3157 }
3158 }
3159
3160 return 0;
3161 }
3162
3163 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3164 struct audit_context *actx)
3165 {
3166 struct context *ctxt;
3167 struct mls_level *level;
3168 struct selinux_audit_rule *rule = vrule;
3169 int match = 0;
3170
3171 if (unlikely(!rule)) {
3172 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3173 return -ENOENT;
3174 }
3175
3176 read_lock(&policy_rwlock);
3177
3178 if (rule->au_seqno < latest_granting) {
3179 match = -ESTALE;
3180 goto out;
3181 }
3182
3183 ctxt = sidtab_search(&sidtab, sid);
3184 if (unlikely(!ctxt)) {
3185 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3186 sid);
3187 match = -ENOENT;
3188 goto out;
3189 }
3190
3191 /* a field/op pair that is not caught here will simply fall through
3192 without a match */
3193 switch (field) {
3194 case AUDIT_SUBJ_USER:
3195 case AUDIT_OBJ_USER:
3196 switch (op) {
3197 case Audit_equal:
3198 match = (ctxt->user == rule->au_ctxt.user);
3199 break;
3200 case Audit_not_equal:
3201 match = (ctxt->user != rule->au_ctxt.user);
3202 break;
3203 }
3204 break;
3205 case AUDIT_SUBJ_ROLE:
3206 case AUDIT_OBJ_ROLE:
3207 switch (op) {
3208 case Audit_equal:
3209 match = (ctxt->role == rule->au_ctxt.role);
3210 break;
3211 case Audit_not_equal:
3212 match = (ctxt->role != rule->au_ctxt.role);
3213 break;
3214 }
3215 break;
3216 case AUDIT_SUBJ_TYPE:
3217 case AUDIT_OBJ_TYPE:
3218 switch (op) {
3219 case Audit_equal:
3220 match = (ctxt->type == rule->au_ctxt.type);
3221 break;
3222 case Audit_not_equal:
3223 match = (ctxt->type != rule->au_ctxt.type);
3224 break;
3225 }
3226 break;
3227 case AUDIT_SUBJ_SEN:
3228 case AUDIT_SUBJ_CLR:
3229 case AUDIT_OBJ_LEV_LOW:
3230 case AUDIT_OBJ_LEV_HIGH:
3231 level = ((field == AUDIT_SUBJ_SEN ||
3232 field == AUDIT_OBJ_LEV_LOW) ?
3233 &ctxt->range.level[0] : &ctxt->range.level[1]);
3234 switch (op) {
3235 case Audit_equal:
3236 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3237 level);
3238 break;
3239 case Audit_not_equal:
3240 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3241 level);
3242 break;
3243 case Audit_lt:
3244 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3245 level) &&
3246 !mls_level_eq(&rule->au_ctxt.range.level[0],
3247 level));
3248 break;
3249 case Audit_le:
3250 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3251 level);
3252 break;
3253 case Audit_gt:
3254 match = (mls_level_dom(level,
3255 &rule->au_ctxt.range.level[0]) &&
3256 !mls_level_eq(level,
3257 &rule->au_ctxt.range.level[0]));
3258 break;
3259 case Audit_ge:
3260 match = mls_level_dom(level,
3261 &rule->au_ctxt.range.level[0]);
3262 break;
3263 }
3264 }
3265
3266 out:
3267 read_unlock(&policy_rwlock);
3268 return match;
3269 }
3270
3271 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3272
3273 static int aurule_avc_callback(u32 event)
3274 {
3275 int err = 0;
3276
3277 if (event == AVC_CALLBACK_RESET && aurule_callback)
3278 err = aurule_callback();
3279 return err;
3280 }
3281
3282 static int __init aurule_init(void)
3283 {
3284 int err;
3285
3286 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3287 if (err)
3288 panic("avc_add_callback() failed, error %d\n", err);
3289
3290 return err;
3291 }
3292 __initcall(aurule_init);
3293
3294 #ifdef CONFIG_NETLABEL
3295 /**
3296 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3297 * @secattr: the NetLabel packet security attributes
3298 * @sid: the SELinux SID
3299 *
3300 * Description:
3301 * Attempt to cache the context in @ctx, which was derived from the packet in
3302 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3303 * already been initialized.
3304 *
3305 */
3306 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3307 u32 sid)
3308 {
3309 u32 *sid_cache;
3310
3311 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3312 if (sid_cache == NULL)
3313 return;
3314 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3315 if (secattr->cache == NULL) {
3316 kfree(sid_cache);
3317 return;
3318 }
3319
3320 *sid_cache = sid;
3321 secattr->cache->free = kfree;
3322 secattr->cache->data = sid_cache;
3323 secattr->flags |= NETLBL_SECATTR_CACHE;
3324 }
3325
3326 /**
3327 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3328 * @secattr: the NetLabel packet security attributes
3329 * @sid: the SELinux SID
3330 *
3331 * Description:
3332 * Convert the given NetLabel security attributes in @secattr into a
3333 * SELinux SID. If the @secattr field does not contain a full SELinux
3334 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3335 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3336 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3337 * conversion for future lookups. Returns zero on success, negative values on
3338 * failure.
3339 *
3340 */
3341 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3342 u32 *sid)
3343 {
3344 int rc;
3345 struct context *ctx;
3346 struct context ctx_new;
3347
3348 if (!ss_initialized) {
3349 *sid = SECSID_NULL;
3350 return 0;
3351 }
3352
3353 read_lock(&policy_rwlock);
3354
3355 if (secattr->flags & NETLBL_SECATTR_CACHE)
3356 *sid = *(u32 *)secattr->cache->data;
3357 else if (secattr->flags & NETLBL_SECATTR_SECID)
3358 *sid = secattr->attr.secid;
3359 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3360 rc = -EIDRM;
3361 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3362 if (ctx == NULL)
3363 goto out;
3364
3365 context_init(&ctx_new);
3366 ctx_new.user = ctx->user;
3367 ctx_new.role = ctx->role;
3368 ctx_new.type = ctx->type;
3369 mls_import_netlbl_lvl(&ctx_new, secattr);
3370 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3371 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3372 if (rc)
3373 goto out;
3374 }
3375 rc = -EIDRM;
3376 if (!mls_context_isvalid(&policydb, &ctx_new))
3377 goto out_free;
3378
3379 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3380 if (rc)
3381 goto out_free;
3382
3383 security_netlbl_cache_add(secattr, *sid);
3384
3385 ebitmap_destroy(&ctx_new.range.level[0].cat);
3386 } else
3387 *sid = SECSID_NULL;
3388
3389 read_unlock(&policy_rwlock);
3390 return 0;
3391 out_free:
3392 ebitmap_destroy(&ctx_new.range.level[0].cat);
3393 out:
3394 read_unlock(&policy_rwlock);
3395 return rc;
3396 }
3397
3398 /**
3399 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3400 * @sid: the SELinux SID
3401 * @secattr: the NetLabel packet security attributes
3402 *
3403 * Description:
3404 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3405 * Returns zero on success, negative values on failure.
3406 *
3407 */
3408 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3409 {
3410 int rc;
3411 struct context *ctx;
3412
3413 if (!ss_initialized)
3414 return 0;
3415
3416 read_lock(&policy_rwlock);
3417
3418 rc = -ENOENT;
3419 ctx = sidtab_search(&sidtab, sid);
3420 if (ctx == NULL)
3421 goto out;
3422
3423 rc = -ENOMEM;
3424 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3425 GFP_ATOMIC);
3426 if (secattr->domain == NULL)
3427 goto out;
3428
3429 secattr->attr.secid = sid;
3430 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3431 mls_export_netlbl_lvl(ctx, secattr);
3432 rc = mls_export_netlbl_cat(ctx, secattr);
3433 out:
3434 read_unlock(&policy_rwlock);
3435 return rc;
3436 }
3437 #endif /* CONFIG_NETLABEL */
3438
3439 /**
3440 * security_read_policy - read the policy.
3441 * @data: binary policy data
3442 * @len: length of data in bytes
3443 *
3444 */
3445 int security_read_policy(void **data, size_t *len)
3446 {
3447 int rc;
3448 struct policy_file fp;
3449
3450 if (!ss_initialized)
3451 return -EINVAL;
3452
3453 *len = security_policydb_len();
3454
3455 *data = vmalloc_user(*len);
3456 if (!*data)
3457 return -ENOMEM;
3458
3459 fp.data = *data;
3460 fp.len = *len;
3461
3462 read_lock(&policy_rwlock);
3463 rc = policydb_write(&policydb, &fp);
3464 read_unlock(&policy_rwlock);
3465
3466 if (rc)
3467 return rc;
3468
3469 *len = (unsigned long)fp.data - (unsigned long)*data;
3470 return 0;
3471
3472 }
Linux kernel - Deliverables
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