projects / deliverable / linux.git / blob
? search:


2aa9d172dc7e73d87ccbc7f73bbc3e8ad2206e45
[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
100 struct selinux_mapping {
101 u16 value; /* policy value */
102 unsigned num_perms;
103 u32 perms[sizeof(u32) * 8];
104 };
105
106 static struct selinux_mapping *current_mapping;
107 static u16 current_mapping_size;
108
109 static int selinux_set_mapping(struct policydb *pol,
110 struct security_class_mapping *map,
111 struct selinux_mapping **out_map_p,
112 u16 *out_map_size)
113 {
114 struct selinux_mapping *out_map = NULL;
115 size_t size = sizeof(struct selinux_mapping);
116 u16 i, j;
117 unsigned k;
118 bool print_unknown_handle = false;
119
120 /* Find number of classes in the input mapping */
121 if (!map)
122 return -EINVAL;
123 i = 0;
124 while (map[i].name)
125 i++;
126
127 /* Allocate space for the class records, plus one for class zero */
128 out_map = kcalloc(++i, size, GFP_ATOMIC);
129 if (!out_map)
130 return -ENOMEM;
131
132 /* Store the raw class and permission values */
133 j = 0;
134 while (map[j].name) {
135 struct security_class_mapping *p_in = map + (j++);
136 struct selinux_mapping *p_out = out_map + j;
137
138 /* An empty class string skips ahead */
139 if (!strcmp(p_in->name, "")) {
140 p_out->num_perms = 0;
141 continue;
142 }
143
144 p_out->value = string_to_security_class(pol, p_in->name);
145 if (!p_out->value) {
146 printk(KERN_INFO
147 "SELinux: Class %s not defined in policy.\n",
148 p_in->name);
149 if (pol->reject_unknown)
150 goto err;
151 p_out->num_perms = 0;
152 print_unknown_handle = true;
153 continue;
154 }
155
156 k = 0;
157 while (p_in->perms && p_in->perms[k]) {
158 /* An empty permission string skips ahead */
159 if (!*p_in->perms[k]) {
160 k++;
161 continue;
162 }
163 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
164 p_in->perms[k]);
165 if (!p_out->perms[k]) {
166 printk(KERN_INFO
167 "SELinux: Permission %s in class %s not defined in policy.\n",
168 p_in->perms[k], p_in->name);
169 if (pol->reject_unknown)
170 goto err;
171 print_unknown_handle = true;
172 }
173
174 k++;
175 }
176 p_out->num_perms = k;
177 }
178
179 if (print_unknown_handle)
180 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
181 pol->allow_unknown ? "allowed" : "denied");
182
183 *out_map_p = out_map;
184 *out_map_size = i;
185 return 0;
186 err:
187 kfree(out_map);
188 return -EINVAL;
189 }
190
191 /*
192 * Get real, policy values from mapped values
193 */
194
195 static u16 unmap_class(u16 tclass)
196 {
197 if (tclass < current_mapping_size)
198 return current_mapping[tclass].value;
199
200 return tclass;
201 }
202
203 /*
204 * Get kernel value for class from its policy value
205 */
206 static u16 map_class(u16 pol_value)
207 {
208 u16 i;
209
210 for (i = 1; i < current_mapping_size; i++) {
211 if (current_mapping[i].value == pol_value)
212 return i;
213 }
214
215 return SECCLASS_NULL;
216 }
217
218 static void map_decision(u16 tclass, struct av_decision *avd,
219 int allow_unknown)
220 {
221 if (tclass < current_mapping_size) {
222 unsigned i, n = current_mapping[tclass].num_perms;
223 u32 result;
224
225 for (i = 0, result = 0; i < n; i++) {
226 if (avd->allowed & current_mapping[tclass].perms[i])
227 result |= 1<<i;
228 if (allow_unknown && !current_mapping[tclass].perms[i])
229 result |= 1<<i;
230 }
231 avd->allowed = result;
232
233 for (i = 0, result = 0; i < n; i++)
234 if (avd->auditallow & current_mapping[tclass].perms[i])
235 result |= 1<<i;
236 avd->auditallow = result;
237
238 for (i = 0, result = 0; i < n; i++) {
239 if (avd->auditdeny & current_mapping[tclass].perms[i])
240 result |= 1<<i;
241 if (!allow_unknown && !current_mapping[tclass].perms[i])
242 result |= 1<<i;
243 }
244 /*
245 * In case the kernel has a bug and requests a permission
246 * between num_perms and the maximum permission number, we
247 * should audit that denial
248 */
249 for (; i < (sizeof(u32)*8); i++)
250 result |= 1<<i;
251 avd->auditdeny = result;
252 }
253 }
254
255 int security_mls_enabled(void)
256 {
257 return policydb.mls_enabled;
258 }
259
260 /*
261 * Return the boolean value of a constraint expression
262 * when it is applied to the specified source and target
263 * security contexts.
264 *
265 * xcontext is a special beast... It is used by the validatetrans rules
266 * only. For these rules, scontext is the context before the transition,
267 * tcontext is the context after the transition, and xcontext is the context
268 * of the process performing the transition. All other callers of
269 * constraint_expr_eval should pass in NULL for xcontext.
270 */
271 static int constraint_expr_eval(struct context *scontext,
272 struct context *tcontext,
273 struct context *xcontext,
274 struct constraint_expr *cexpr)
275 {
276 u32 val1, val2;
277 struct context *c;
278 struct role_datum *r1, *r2;
279 struct mls_level *l1, *l2;
280 struct constraint_expr *e;
281 int s[CEXPR_MAXDEPTH];
282 int sp = -1;
283
284 for (e = cexpr; e; e = e->next) {
285 switch (e->expr_type) {
286 case CEXPR_NOT:
287 BUG_ON(sp < 0);
288 s[sp] = !s[sp];
289 break;
290 case CEXPR_AND:
291 BUG_ON(sp < 1);
292 sp--;
293 s[sp] &= s[sp + 1];
294 break;
295 case CEXPR_OR:
296 BUG_ON(sp < 1);
297 sp--;
298 s[sp] |= s[sp + 1];
299 break;
300 case CEXPR_ATTR:
301 if (sp == (CEXPR_MAXDEPTH - 1))
302 return 0;
303 switch (e->attr) {
304 case CEXPR_USER:
305 val1 = scontext->user;
306 val2 = tcontext->user;
307 break;
308 case CEXPR_TYPE:
309 val1 = scontext->type;
310 val2 = tcontext->type;
311 break;
312 case CEXPR_ROLE:
313 val1 = scontext->role;
314 val2 = tcontext->role;
315 r1 = policydb.role_val_to_struct[val1 - 1];
316 r2 = policydb.role_val_to_struct[val2 - 1];
317 switch (e->op) {
318 case CEXPR_DOM:
319 s[++sp] = ebitmap_get_bit(&r1->dominates,
320 val2 - 1);
321 continue;
322 case CEXPR_DOMBY:
323 s[++sp] = ebitmap_get_bit(&r2->dominates,
324 val1 - 1);
325 continue;
326 case CEXPR_INCOMP:
327 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
328 val2 - 1) &&
329 !ebitmap_get_bit(&r2->dominates,
330 val1 - 1));
331 continue;
332 default:
333 break;
334 }
335 break;
336 case CEXPR_L1L2:
337 l1 = &(scontext->range.level[0]);
338 l2 = &(tcontext->range.level[0]);
339 goto mls_ops;
340 case CEXPR_L1H2:
341 l1 = &(scontext->range.level[0]);
342 l2 = &(tcontext->range.level[1]);
343 goto mls_ops;
344 case CEXPR_H1L2:
345 l1 = &(scontext->range.level[1]);
346 l2 = &(tcontext->range.level[0]);
347 goto mls_ops;
348 case CEXPR_H1H2:
349 l1 = &(scontext->range.level[1]);
350 l2 = &(tcontext->range.level[1]);
351 goto mls_ops;
352 case CEXPR_L1H1:
353 l1 = &(scontext->range.level[0]);
354 l2 = &(scontext->range.level[1]);
355 goto mls_ops;
356 case CEXPR_L2H2:
357 l1 = &(tcontext->range.level[0]);
358 l2 = &(tcontext->range.level[1]);
359 goto mls_ops;
360 mls_ops:
361 switch (e->op) {
362 case CEXPR_EQ:
363 s[++sp] = mls_level_eq(l1, l2);
364 continue;
365 case CEXPR_NEQ:
366 s[++sp] = !mls_level_eq(l1, l2);
367 continue;
368 case CEXPR_DOM:
369 s[++sp] = mls_level_dom(l1, l2);
370 continue;
371 case CEXPR_DOMBY:
372 s[++sp] = mls_level_dom(l2, l1);
373 continue;
374 case CEXPR_INCOMP:
375 s[++sp] = mls_level_incomp(l2, l1);
376 continue;
377 default:
378 BUG();
379 return 0;
380 }
381 break;
382 default:
383 BUG();
384 return 0;
385 }
386
387 switch (e->op) {
388 case CEXPR_EQ:
389 s[++sp] = (val1 == val2);
390 break;
391 case CEXPR_NEQ:
392 s[++sp] = (val1 != val2);
393 break;
394 default:
395 BUG();
396 return 0;
397 }
398 break;
399 case CEXPR_NAMES:
400 if (sp == (CEXPR_MAXDEPTH-1))
401 return 0;
402 c = scontext;
403 if (e->attr & CEXPR_TARGET)
404 c = tcontext;
405 else if (e->attr & CEXPR_XTARGET) {
406 c = xcontext;
407 if (!c) {
408 BUG();
409 return 0;
410 }
411 }
412 if (e->attr & CEXPR_USER)
413 val1 = c->user;
414 else if (e->attr & CEXPR_ROLE)
415 val1 = c->role;
416 else if (e->attr & CEXPR_TYPE)
417 val1 = c->type;
418 else {
419 BUG();
420 return 0;
421 }
422
423 switch (e->op) {
424 case CEXPR_EQ:
425 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
426 break;
427 case CEXPR_NEQ:
428 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
429 break;
430 default:
431 BUG();
432 return 0;
433 }
434 break;
435 default:
436 BUG();
437 return 0;
438 }
439 }
440
441 BUG_ON(sp != 0);
442 return s[0];
443 }
444
445 /*
446 * security_dump_masked_av - dumps masked permissions during
447 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
448 */
449 static int dump_masked_av_helper(void *k, void *d, void *args)
450 {
451 struct perm_datum *pdatum = d;
452 char **permission_names = args;
453
454 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
455
456 permission_names[pdatum->value - 1] = (char *)k;
457
458 return 0;
459 }
460
461 static void security_dump_masked_av(struct context *scontext,
462 struct context *tcontext,
463 u16 tclass,
464 u32 permissions,
465 const char *reason)
466 {
467 struct common_datum *common_dat;
468 struct class_datum *tclass_dat;
469 struct audit_buffer *ab;
470 char *tclass_name;
471 char *scontext_name = NULL;
472 char *tcontext_name = NULL;
473 char *permission_names[32];
474 int index;
475 u32 length;
476 bool need_comma = false;
477
478 if (!permissions)
479 return;
480
481 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
482 tclass_dat = policydb.class_val_to_struct[tclass - 1];
483 common_dat = tclass_dat->comdatum;
484
485 /* init permission_names */
486 if (common_dat &&
487 hashtab_map(common_dat->permissions.table,
488 dump_masked_av_helper, permission_names) < 0)
489 goto out;
490
491 if (hashtab_map(tclass_dat->permissions.table,
492 dump_masked_av_helper, permission_names) < 0)
493 goto out;
494
495 /* get scontext/tcontext in text form */
496 if (context_struct_to_string(scontext,
497 &scontext_name, &length) < 0)
498 goto out;
499
500 if (context_struct_to_string(tcontext,
501 &tcontext_name, &length) < 0)
502 goto out;
503
504 /* audit a message */
505 ab = audit_log_start(current->audit_context,
506 GFP_ATOMIC, AUDIT_SELINUX_ERR);
507 if (!ab)
508 goto out;
509
510 audit_log_format(ab, "op=security_compute_av reason=%s "
511 "scontext=%s tcontext=%s tclass=%s perms=",
512 reason, scontext_name, tcontext_name, tclass_name);
513
514 for (index = 0; index < 32; index++) {
515 u32 mask = (1 << index);
516
517 if ((mask & permissions) == 0)
518 continue;
519
520 audit_log_format(ab, "%s%s",
521 need_comma ? "," : "",
522 permission_names[index]
523 ? permission_names[index] : "????");
524 need_comma = true;
525 }
526 audit_log_end(ab);
527 out:
528 /* release scontext/tcontext */
529 kfree(tcontext_name);
530 kfree(scontext_name);
531
532 return;
533 }
534
535 /*
536 * security_boundary_permission - drops violated permissions
537 * on boundary constraint.
538 */
539 static void type_attribute_bounds_av(struct context *scontext,
540 struct context *tcontext,
541 u16 tclass,
542 struct av_decision *avd)
543 {
544 struct context lo_scontext;
545 struct context lo_tcontext;
546 struct av_decision lo_avd;
547 struct type_datum *source;
548 struct type_datum *target;
549 u32 masked = 0;
550
551 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
552 scontext->type - 1);
553 BUG_ON(!source);
554
555 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
556 tcontext->type - 1);
557 BUG_ON(!target);
558
559 if (source->bounds) {
560 memset(&lo_avd, 0, sizeof(lo_avd));
561
562 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
563 lo_scontext.type = source->bounds;
564
565 context_struct_compute_av(&lo_scontext,
566 tcontext,
567 tclass,
568 &lo_avd);
569 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
570 return; /* no masked permission */
571 masked = ~lo_avd.allowed & avd->allowed;
572 }
573
574 if (target->bounds) {
575 memset(&lo_avd, 0, sizeof(lo_avd));
576
577 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
578 lo_tcontext.type = target->bounds;
579
580 context_struct_compute_av(scontext,
581 &lo_tcontext,
582 tclass,
583 &lo_avd);
584 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
585 return; /* no masked permission */
586 masked = ~lo_avd.allowed & avd->allowed;
587 }
588
589 if (source->bounds && target->bounds) {
590 memset(&lo_avd, 0, sizeof(lo_avd));
591 /*
592 * lo_scontext and lo_tcontext are already
593 * set up.
594 */
595
596 context_struct_compute_av(&lo_scontext,
597 &lo_tcontext,
598 tclass,
599 &lo_avd);
600 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
601 return; /* no masked permission */
602 masked = ~lo_avd.allowed & avd->allowed;
603 }
604
605 if (masked) {
606 /* mask violated permissions */
607 avd->allowed &= ~masked;
608
609 /* audit masked permissions */
610 security_dump_masked_av(scontext, tcontext,
611 tclass, masked, "bounds");
612 }
613 }
614
615 /*
616 * Compute access vectors based on a context structure pair for
617 * the permissions in a particular class.
618 */
619 static void context_struct_compute_av(struct context *scontext,
620 struct context *tcontext,
621 u16 tclass,
622 struct av_decision *avd)
623 {
624 struct constraint_node *constraint;
625 struct role_allow *ra;
626 struct avtab_key avkey;
627 struct avtab_node *node;
628 struct class_datum *tclass_datum;
629 struct ebitmap *sattr, *tattr;
630 struct ebitmap_node *snode, *tnode;
631 unsigned int i, j;
632
633 avd->allowed = 0;
634 avd->auditallow = 0;
635 avd->auditdeny = 0xffffffff;
636
637 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
638 if (printk_ratelimit())
639 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
640 return;
641 }
642
643 tclass_datum = policydb.class_val_to_struct[tclass - 1];
644
645 /*
646 * If a specific type enforcement rule was defined for
647 * this permission check, then use it.
648 */
649 avkey.target_class = tclass;
650 avkey.specified = AVTAB_AV;
651 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
652 BUG_ON(!sattr);
653 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
654 BUG_ON(!tattr);
655 ebitmap_for_each_positive_bit(sattr, snode, i) {
656 ebitmap_for_each_positive_bit(tattr, tnode, j) {
657 avkey.source_type = i + 1;
658 avkey.target_type = j + 1;
659 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
660 node;
661 node = avtab_search_node_next(node, avkey.specified)) {
662 if (node->key.specified == AVTAB_ALLOWED)
663 avd->allowed |= node->datum.data;
664 else if (node->key.specified == AVTAB_AUDITALLOW)
665 avd->auditallow |= node->datum.data;
666 else if (node->key.specified == AVTAB_AUDITDENY)
667 avd->auditdeny &= node->datum.data;
668 }
669
670 /* Check conditional av table for additional permissions */
671 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
672
673 }
674 }
675
676 /*
677 * Remove any permissions prohibited by a constraint (this includes
678 * the MLS policy).
679 */
680 constraint = tclass_datum->constraints;
681 while (constraint) {
682 if ((constraint->permissions & (avd->allowed)) &&
683 !constraint_expr_eval(scontext, tcontext, NULL,
684 constraint->expr)) {
685 avd->allowed &= ~(constraint->permissions);
686 }
687 constraint = constraint->next;
688 }
689
690 /*
691 * If checking process transition permission and the
692 * role is changing, then check the (current_role, new_role)
693 * pair.
694 */
695 if (tclass == policydb.process_class &&
696 (avd->allowed & policydb.process_trans_perms) &&
697 scontext->role != tcontext->role) {
698 for (ra = policydb.role_allow; ra; ra = ra->next) {
699 if (scontext->role == ra->role &&
700 tcontext->role == ra->new_role)
701 break;
702 }
703 if (!ra)
704 avd->allowed &= ~policydb.process_trans_perms;
705 }
706
707 /*
708 * If the given source and target types have boundary
709 * constraint, lazy checks have to mask any violated
710 * permission and notice it to userspace via audit.
711 */
712 type_attribute_bounds_av(scontext, tcontext,
713 tclass, avd);
714 }
715
716 static int security_validtrans_handle_fail(struct context *ocontext,
717 struct context *ncontext,
718 struct context *tcontext,
719 u16 tclass)
720 {
721 char *o = NULL, *n = NULL, *t = NULL;
722 u32 olen, nlen, tlen;
723
724 if (context_struct_to_string(ocontext, &o, &olen))
725 goto out;
726 if (context_struct_to_string(ncontext, &n, &nlen))
727 goto out;
728 if (context_struct_to_string(tcontext, &t, &tlen))
729 goto out;
730 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
731 "security_validate_transition: denied for"
732 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
733 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
734 out:
735 kfree(o);
736 kfree(n);
737 kfree(t);
738
739 if (!selinux_enforcing)
740 return 0;
741 return -EPERM;
742 }
743
744 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
745 u16 orig_tclass)
746 {
747 struct context *ocontext;
748 struct context *ncontext;
749 struct context *tcontext;
750 struct class_datum *tclass_datum;
751 struct constraint_node *constraint;
752 u16 tclass;
753 int rc = 0;
754
755 if (!ss_initialized)
756 return 0;
757
758 read_lock(&policy_rwlock);
759
760 tclass = unmap_class(orig_tclass);
761
762 if (!tclass || tclass > policydb.p_classes.nprim) {
763 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
764 __func__, tclass);
765 rc = -EINVAL;
766 goto out;
767 }
768 tclass_datum = policydb.class_val_to_struct[tclass - 1];
769
770 ocontext = sidtab_search(&sidtab, oldsid);
771 if (!ocontext) {
772 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
773 __func__, oldsid);
774 rc = -EINVAL;
775 goto out;
776 }
777
778 ncontext = sidtab_search(&sidtab, newsid);
779 if (!ncontext) {
780 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
781 __func__, newsid);
782 rc = -EINVAL;
783 goto out;
784 }
785
786 tcontext = sidtab_search(&sidtab, tasksid);
787 if (!tcontext) {
788 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
789 __func__, tasksid);
790 rc = -EINVAL;
791 goto out;
792 }
793
794 constraint = tclass_datum->validatetrans;
795 while (constraint) {
796 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
797 constraint->expr)) {
798 rc = security_validtrans_handle_fail(ocontext, ncontext,
799 tcontext, tclass);
800 goto out;
801 }
802 constraint = constraint->next;
803 }
804
805 out:
806 read_unlock(&policy_rwlock);
807 return rc;
808 }
809
810 /*
811 * security_bounded_transition - check whether the given
812 * transition is directed to bounded, or not.
813 * It returns 0, if @newsid is bounded by @oldsid.
814 * Otherwise, it returns error code.
815 *
816 * @oldsid : current security identifier
817 * @newsid : destinated security identifier
818 */
819 int security_bounded_transition(u32 old_sid, u32 new_sid)
820 {
821 struct context *old_context, *new_context;
822 struct type_datum *type;
823 int index;
824 int rc;
825
826 read_lock(&policy_rwlock);
827
828 rc = -EINVAL;
829 old_context = sidtab_search(&sidtab, old_sid);
830 if (!old_context) {
831 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
832 __func__, old_sid);
833 goto out;
834 }
835
836 rc = -EINVAL;
837 new_context = sidtab_search(&sidtab, new_sid);
838 if (!new_context) {
839 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
840 __func__, new_sid);
841 goto out;
842 }
843
844 rc = 0;
845 /* type/domain unchanged */
846 if (old_context->type == new_context->type)
847 goto out;
848
849 index = new_context->type;
850 while (true) {
851 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
852 index - 1);
853 BUG_ON(!type);
854
855 /* not bounded anymore */
856 rc = -EPERM;
857 if (!type->bounds)
858 break;
859
860 /* @newsid is bounded by @oldsid */
861 rc = 0;
862 if (type->bounds == old_context->type)
863 break;
864
865 index = type->bounds;
866 }
867
868 if (rc) {
869 char *old_name = NULL;
870 char *new_name = NULL;
871 u32 length;
872
873 if (!context_struct_to_string(old_context,
874 &old_name, &length) &&
875 !context_struct_to_string(new_context,
876 &new_name, &length)) {
877 audit_log(current->audit_context,
878 GFP_ATOMIC, AUDIT_SELINUX_ERR,
879 "op=security_bounded_transition "
880 "result=denied "
881 "oldcontext=%s newcontext=%s",
882 old_name, new_name);
883 }
884 kfree(new_name);
885 kfree(old_name);
886 }
887 out:
888 read_unlock(&policy_rwlock);
889
890 return rc;
891 }
892
893 static void avd_init(struct av_decision *avd)
894 {
895 avd->allowed = 0;
896 avd->auditallow = 0;
897 avd->auditdeny = 0xffffffff;
898 avd->seqno = latest_granting;
899 avd->flags = 0;
900 }
901
902
903 /**
904 * security_compute_av - Compute access vector decisions.
905 * @ssid: source security identifier
906 * @tsid: target security identifier
907 * @tclass: target security class
908 * @avd: access vector decisions
909 *
910 * Compute a set of access vector decisions based on the
911 * SID pair (@ssid, @tsid) for the permissions in @tclass.
912 */
913 void security_compute_av(u32 ssid,
914 u32 tsid,
915 u16 orig_tclass,
916 struct av_decision *avd)
917 {
918 u16 tclass;
919 struct context *scontext = NULL, *tcontext = NULL;
920
921 read_lock(&policy_rwlock);
922 avd_init(avd);
923 if (!ss_initialized)
924 goto allow;
925
926 scontext = sidtab_search(&sidtab, ssid);
927 if (!scontext) {
928 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
929 __func__, ssid);
930 goto out;
931 }
932
933 /* permissive domain? */
934 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
935 avd->flags |= AVD_FLAGS_PERMISSIVE;
936
937 tcontext = sidtab_search(&sidtab, tsid);
938 if (!tcontext) {
939 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
940 __func__, tsid);
941 goto out;
942 }
943
944 tclass = unmap_class(orig_tclass);
945 if (unlikely(orig_tclass && !tclass)) {
946 if (policydb.allow_unknown)
947 goto allow;
948 goto out;
949 }
950 context_struct_compute_av(scontext, tcontext, tclass, avd);
951 map_decision(orig_tclass, avd, policydb.allow_unknown);
952 out:
953 read_unlock(&policy_rwlock);
954 return;
955 allow:
956 avd->allowed = 0xffffffff;
957 goto out;
958 }
959
960 void security_compute_av_user(u32 ssid,
961 u32 tsid,
962 u16 tclass,
963 struct av_decision *avd)
964 {
965 struct context *scontext = NULL, *tcontext = NULL;
966
967 read_lock(&policy_rwlock);
968 avd_init(avd);
969 if (!ss_initialized)
970 goto allow;
971
972 scontext = sidtab_search(&sidtab, ssid);
973 if (!scontext) {
974 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
975 __func__, ssid);
976 goto out;
977 }
978
979 /* permissive domain? */
980 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
981 avd->flags |= AVD_FLAGS_PERMISSIVE;
982
983 tcontext = sidtab_search(&sidtab, tsid);
984 if (!tcontext) {
985 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
986 __func__, tsid);
987 goto out;
988 }
989
990 if (unlikely(!tclass)) {
991 if (policydb.allow_unknown)
992 goto allow;
993 goto out;
994 }
995
996 context_struct_compute_av(scontext, tcontext, tclass, avd);
997 out:
998 read_unlock(&policy_rwlock);
999 return;
1000 allow:
1001 avd->allowed = 0xffffffff;
1002 goto out;
1003 }
1004
1005 /*
1006 * Write the security context string representation of
1007 * the context structure `context' into a dynamically
1008 * allocated string of the correct size. Set `*scontext'
1009 * to point to this string and set `*scontext_len' to
1010 * the length of the string.
1011 */
1012 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1013 {
1014 char *scontextp;
1015
1016 if (scontext)
1017 *scontext = NULL;
1018 *scontext_len = 0;
1019
1020 if (context->len) {
1021 *scontext_len = context->len;
1022 if (scontext) {
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 }
1027 return 0;
1028 }
1029
1030 /* Compute the size of the context. */
1031 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1033 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1034 *scontext_len += mls_compute_context_len(context);
1035
1036 if (!scontext)
1037 return 0;
1038
1039 /* Allocate space for the context; caller must free this space. */
1040 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1041 if (!scontextp)
1042 return -ENOMEM;
1043 *scontext = scontextp;
1044
1045 /*
1046 * Copy the user name, role name and type name into the context.
1047 */
1048 sprintf(scontextp, "%s:%s:%s",
1049 sym_name(&policydb, SYM_USERS, context->user - 1),
1050 sym_name(&policydb, SYM_ROLES, context->role - 1),
1051 sym_name(&policydb, SYM_TYPES, context->type - 1));
1052 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1054 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1055
1056 mls_sid_to_context(context, &scontextp);
1057
1058 *scontextp = 0;
1059
1060 return 0;
1061 }
1062
1063 #include "initial_sid_to_string.h"
1064
1065 const char *security_get_initial_sid_context(u32 sid)
1066 {
1067 if (unlikely(sid > SECINITSID_NUM))
1068 return NULL;
1069 return initial_sid_to_string[sid];
1070 }
1071
1072 static int security_sid_to_context_core(u32 sid, char **scontext,
1073 u32 *scontext_len, int force)
1074 {
1075 struct context *context;
1076 int rc = 0;
1077
1078 if (scontext)
1079 *scontext = NULL;
1080 *scontext_len = 0;
1081
1082 if (!ss_initialized) {
1083 if (sid <= SECINITSID_NUM) {
1084 char *scontextp;
1085
1086 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1087 if (!scontext)
1088 goto out;
1089 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1090 if (!scontextp) {
1091 rc = -ENOMEM;
1092 goto out;
1093 }
1094 strcpy(scontextp, initial_sid_to_string[sid]);
1095 *scontext = scontextp;
1096 goto out;
1097 }
1098 printk(KERN_ERR "SELinux: %s: called before initial "
1099 "load_policy on unknown SID %d\n", __func__, sid);
1100 rc = -EINVAL;
1101 goto out;
1102 }
1103 read_lock(&policy_rwlock);
1104 if (force)
1105 context = sidtab_search_force(&sidtab, sid);
1106 else
1107 context = sidtab_search(&sidtab, sid);
1108 if (!context) {
1109 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1110 __func__, sid);
1111 rc = -EINVAL;
1112 goto out_unlock;
1113 }
1114 rc = context_struct_to_string(context, scontext, scontext_len);
1115 out_unlock:
1116 read_unlock(&policy_rwlock);
1117 out:
1118 return rc;
1119
1120 }
1121
1122 /**
1123 * security_sid_to_context - Obtain a context for a given SID.
1124 * @sid: security identifier, SID
1125 * @scontext: security context
1126 * @scontext_len: length in bytes
1127 *
1128 * Write the string representation of the context associated with @sid
1129 * into a dynamically allocated string of the correct size. Set @scontext
1130 * to point to this string and set @scontext_len to the length of the string.
1131 */
1132 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1133 {
1134 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1135 }
1136
1137 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1138 {
1139 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1140 }
1141
1142 /*
1143 * Caveat: Mutates scontext.
1144 */
1145 static int string_to_context_struct(struct policydb *pol,
1146 struct sidtab *sidtabp,
1147 char *scontext,
1148 u32 scontext_len,
1149 struct context *ctx,
1150 u32 def_sid)
1151 {
1152 struct role_datum *role;
1153 struct type_datum *typdatum;
1154 struct user_datum *usrdatum;
1155 char *scontextp, *p, oldc;
1156 int rc = 0;
1157
1158 context_init(ctx);
1159
1160 /* Parse the security context. */
1161
1162 rc = -EINVAL;
1163 scontextp = (char *) scontext;
1164
1165 /* Extract the user. */
1166 p = scontextp;
1167 while (*p && *p != ':')
1168 p++;
1169
1170 if (*p == 0)
1171 goto out;
1172
1173 *p++ = 0;
1174
1175 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1176 if (!usrdatum)
1177 goto out;
1178
1179 ctx->user = usrdatum->value;
1180
1181 /* Extract role. */
1182 scontextp = p;
1183 while (*p && *p != ':')
1184 p++;
1185
1186 if (*p == 0)
1187 goto out;
1188
1189 *p++ = 0;
1190
1191 role = hashtab_search(pol->p_roles.table, scontextp);
1192 if (!role)
1193 goto out;
1194 ctx->role = role->value;
1195
1196 /* Extract type. */
1197 scontextp = p;
1198 while (*p && *p != ':')
1199 p++;
1200 oldc = *p;
1201 *p++ = 0;
1202
1203 typdatum = hashtab_search(pol->p_types.table, scontextp);
1204 if (!typdatum || typdatum->attribute)
1205 goto out;
1206
1207 ctx->type = typdatum->value;
1208
1209 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1210 if (rc)
1211 goto out;
1212
1213 rc = -EINVAL;
1214 if ((p - scontext) < scontext_len)
1215 goto out;
1216
1217 /* Check the validity of the new context. */
1218 if (!policydb_context_isvalid(pol, ctx))
1219 goto out;
1220 rc = 0;
1221 out:
1222 if (rc)
1223 context_destroy(ctx);
1224 return rc;
1225 }
1226
1227 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1228 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1229 int force)
1230 {
1231 char *scontext2, *str = NULL;
1232 struct context context;
1233 int rc = 0;
1234
1235 /* An empty security context is never valid. */
1236 if (!scontext_len)
1237 return -EINVAL;
1238
1239 if (!ss_initialized) {
1240 int i;
1241
1242 for (i = 1; i < SECINITSID_NUM; i++) {
1243 if (!strcmp(initial_sid_to_string[i], scontext)) {
1244 *sid = i;
1245 return 0;
1246 }
1247 }
1248 *sid = SECINITSID_KERNEL;
1249 return 0;
1250 }
1251 *sid = SECSID_NULL;
1252
1253 /* Copy the string so that we can modify the copy as we parse it. */
1254 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1255 if (!scontext2)
1256 return -ENOMEM;
1257 memcpy(scontext2, scontext, scontext_len);
1258 scontext2[scontext_len] = 0;
1259
1260 if (force) {
1261 /* Save another copy for storing in uninterpreted form */
1262 rc = -ENOMEM;
1263 str = kstrdup(scontext2, gfp_flags);
1264 if (!str)
1265 goto out;
1266 }
1267
1268 read_lock(&policy_rwlock);
1269 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1270 scontext_len, &context, def_sid);
1271 if (rc == -EINVAL && force) {
1272 context.str = str;
1273 context.len = scontext_len;
1274 str = NULL;
1275 } else if (rc)
1276 goto out_unlock;
1277 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1278 context_destroy(&context);
1279 out_unlock:
1280 read_unlock(&policy_rwlock);
1281 out:
1282 kfree(scontext2);
1283 kfree(str);
1284 return rc;
1285 }
1286
1287 /**
1288 * security_context_to_sid - Obtain a SID for a given security context.
1289 * @scontext: security context
1290 * @scontext_len: length in bytes
1291 * @sid: security identifier, SID
1292 * @gfp: context for the allocation
1293 *
1294 * Obtains a SID associated with the security context that
1295 * has the string representation specified by @scontext.
1296 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1297 * memory is available, or 0 on success.
1298 */
1299 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1300 gfp_t gfp)
1301 {
1302 return security_context_to_sid_core(scontext, scontext_len,
1303 sid, SECSID_NULL, gfp, 0);
1304 }
1305
1306 /**
1307 * security_context_to_sid_default - Obtain a SID for a given security context,
1308 * falling back to specified default if needed.
1309 *
1310 * @scontext: security context
1311 * @scontext_len: length in bytes
1312 * @sid: security identifier, SID
1313 * @def_sid: default SID to assign on error
1314 *
1315 * Obtains a SID associated with the security context that
1316 * has the string representation specified by @scontext.
1317 * The default SID is passed to the MLS layer to be used to allow
1318 * kernel labeling of the MLS field if the MLS field is not present
1319 * (for upgrading to MLS without full relabel).
1320 * Implicitly forces adding of the context even if it cannot be mapped yet.
1321 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1322 * memory is available, or 0 on success.
1323 */
1324 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1325 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1326 {
1327 return security_context_to_sid_core(scontext, scontext_len,
1328 sid, def_sid, gfp_flags, 1);
1329 }
1330
1331 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1332 u32 *sid)
1333 {
1334 return security_context_to_sid_core(scontext, scontext_len,
1335 sid, SECSID_NULL, GFP_KERNEL, 1);
1336 }
1337
1338 static int compute_sid_handle_invalid_context(
1339 struct context *scontext,
1340 struct context *tcontext,
1341 u16 tclass,
1342 struct context *newcontext)
1343 {
1344 char *s = NULL, *t = NULL, *n = NULL;
1345 u32 slen, tlen, nlen;
1346
1347 if (context_struct_to_string(scontext, &s, &slen))
1348 goto out;
1349 if (context_struct_to_string(tcontext, &t, &tlen))
1350 goto out;
1351 if (context_struct_to_string(newcontext, &n, &nlen))
1352 goto out;
1353 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1354 "security_compute_sid: invalid context %s"
1355 " for scontext=%s"
1356 " tcontext=%s"
1357 " tclass=%s",
1358 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1359 out:
1360 kfree(s);
1361 kfree(t);
1362 kfree(n);
1363 if (!selinux_enforcing)
1364 return 0;
1365 return -EACCES;
1366 }
1367
1368 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1369 u32 stype, u32 ttype, u16 tclass,
1370 const char *objname)
1371 {
1372 struct filename_trans ft;
1373 struct filename_trans_datum *otype;
1374
1375 /*
1376 * Most filename trans rules are going to live in specific directories
1377 * like /dev or /var/run. This bitmap will quickly skip rule searches
1378 * if the ttype does not contain any rules.
1379 */
1380 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1381 return;
1382
1383 ft.stype = stype;
1384 ft.ttype = ttype;
1385 ft.tclass = tclass;
1386 ft.name = objname;
1387
1388 otype = hashtab_search(p->filename_trans, &ft);
1389 if (otype)
1390 newcontext->type = otype->otype;
1391 }
1392
1393 static int security_compute_sid(u32 ssid,
1394 u32 tsid,
1395 u16 orig_tclass,
1396 u32 specified,
1397 const char *objname,
1398 u32 *out_sid,
1399 bool kern)
1400 {
1401 struct class_datum *cladatum = NULL;
1402 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1403 struct role_trans *roletr = NULL;
1404 struct avtab_key avkey;
1405 struct avtab_datum *avdatum;
1406 struct avtab_node *node;
1407 u16 tclass;
1408 int rc = 0;
1409 bool sock;
1410
1411 if (!ss_initialized) {
1412 switch (orig_tclass) {
1413 case SECCLASS_PROCESS: /* kernel value */
1414 *out_sid = ssid;
1415 break;
1416 default:
1417 *out_sid = tsid;
1418 break;
1419 }
1420 goto out;
1421 }
1422
1423 context_init(&newcontext);
1424
1425 read_lock(&policy_rwlock);
1426
1427 if (kern) {
1428 tclass = unmap_class(orig_tclass);
1429 sock = security_is_socket_class(orig_tclass);
1430 } else {
1431 tclass = orig_tclass;
1432 sock = security_is_socket_class(map_class(tclass));
1433 }
1434
1435 scontext = sidtab_search(&sidtab, ssid);
1436 if (!scontext) {
1437 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1438 __func__, ssid);
1439 rc = -EINVAL;
1440 goto out_unlock;
1441 }
1442 tcontext = sidtab_search(&sidtab, tsid);
1443 if (!tcontext) {
1444 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1445 __func__, tsid);
1446 rc = -EINVAL;
1447 goto out_unlock;
1448 }
1449
1450 if (tclass && tclass <= policydb.p_classes.nprim)
1451 cladatum = policydb.class_val_to_struct[tclass - 1];
1452
1453 /* Set the user identity. */
1454 switch (specified) {
1455 case AVTAB_TRANSITION:
1456 case AVTAB_CHANGE:
1457 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1458 newcontext.user = tcontext->user;
1459 } else {
1460 /* notice this gets both DEFAULT_SOURCE and unset */
1461 /* Use the process user identity. */
1462 newcontext.user = scontext->user;
1463 }
1464 break;
1465 case AVTAB_MEMBER:
1466 /* Use the related object owner. */
1467 newcontext.user = tcontext->user;
1468 break;
1469 }
1470
1471 /* Set the role to default values. */
1472 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1473 newcontext.role = scontext->role;
1474 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1475 newcontext.role = tcontext->role;
1476 } else {
1477 if ((tclass == policydb.process_class) || (sock == true))
1478 newcontext.role = scontext->role;
1479 else
1480 newcontext.role = OBJECT_R_VAL;
1481 }
1482
1483 /* Set the type to default values. */
1484 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1485 newcontext.type = scontext->type;
1486 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1487 newcontext.type = tcontext->type;
1488 } else {
1489 if ((tclass == policydb.process_class) || (sock == true)) {
1490 /* Use the type of process. */
1491 newcontext.type = scontext->type;
1492 } else {
1493 /* Use the type of the related object. */
1494 newcontext.type = tcontext->type;
1495 }
1496 }
1497
1498 /* Look for a type transition/member/change rule. */
1499 avkey.source_type = scontext->type;
1500 avkey.target_type = tcontext->type;
1501 avkey.target_class = tclass;
1502 avkey.specified = specified;
1503 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1504
1505 /* If no permanent rule, also check for enabled conditional rules */
1506 if (!avdatum) {
1507 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1508 for (; node; node = avtab_search_node_next(node, specified)) {
1509 if (node->key.specified & AVTAB_ENABLED) {
1510 avdatum = &node->datum;
1511 break;
1512 }
1513 }
1514 }
1515
1516 if (avdatum) {
1517 /* Use the type from the type transition/member/change rule. */
1518 newcontext.type = avdatum->data;
1519 }
1520
1521 /* if we have a objname this is a file trans check so check those rules */
1522 if (objname)
1523 filename_compute_type(&policydb, &newcontext, scontext->type,
1524 tcontext->type, tclass, objname);
1525
1526 /* Check for class-specific changes. */
1527 if (specified & AVTAB_TRANSITION) {
1528 /* Look for a role transition rule. */
1529 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1530 if ((roletr->role == scontext->role) &&
1531 (roletr->type == tcontext->type) &&
1532 (roletr->tclass == tclass)) {
1533 /* Use the role transition rule. */
1534 newcontext.role = roletr->new_role;
1535 break;
1536 }
1537 }
1538 }
1539
1540 /* Set the MLS attributes.
1541 This is done last because it may allocate memory. */
1542 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1543 &newcontext, sock);
1544 if (rc)
1545 goto out_unlock;
1546
1547 /* Check the validity of the context. */
1548 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1549 rc = compute_sid_handle_invalid_context(scontext,
1550 tcontext,
1551 tclass,
1552 &newcontext);
1553 if (rc)
1554 goto out_unlock;
1555 }
1556 /* Obtain the sid for the context. */
1557 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1558 out_unlock:
1559 read_unlock(&policy_rwlock);
1560 context_destroy(&newcontext);
1561 out:
1562 return rc;
1563 }
1564
1565 /**
1566 * security_transition_sid - Compute the SID for a new subject/object.
1567 * @ssid: source security identifier
1568 * @tsid: target security identifier
1569 * @tclass: target security class
1570 * @out_sid: security identifier for new subject/object
1571 *
1572 * Compute a SID to use for labeling a new subject or object in the
1573 * class @tclass based on a SID pair (@ssid, @tsid).
1574 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1575 * if insufficient memory is available, or %0 if the new SID was
1576 * computed successfully.
1577 */
1578 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1579 const struct qstr *qstr, u32 *out_sid)
1580 {
1581 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1582 qstr ? qstr->name : NULL, out_sid, true);
1583 }
1584
1585 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1586 const char *objname, u32 *out_sid)
1587 {
1588 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1589 objname, out_sid, false);
1590 }
1591
1592 /**
1593 * security_member_sid - Compute the SID for member selection.
1594 * @ssid: source security identifier
1595 * @tsid: target security identifier
1596 * @tclass: target security class
1597 * @out_sid: security identifier for selected member
1598 *
1599 * Compute a SID to use when selecting a member of a polyinstantiated
1600 * object of class @tclass based on a SID pair (@ssid, @tsid).
1601 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1602 * if insufficient memory is available, or %0 if the SID was
1603 * computed successfully.
1604 */
1605 int security_member_sid(u32 ssid,
1606 u32 tsid,
1607 u16 tclass,
1608 u32 *out_sid)
1609 {
1610 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1611 out_sid, false);
1612 }
1613
1614 /**
1615 * security_change_sid - Compute the SID for object relabeling.
1616 * @ssid: source security identifier
1617 * @tsid: target security identifier
1618 * @tclass: target security class
1619 * @out_sid: security identifier for selected member
1620 *
1621 * Compute a SID to use for relabeling an object of class @tclass
1622 * based on a SID pair (@ssid, @tsid).
1623 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1624 * if insufficient memory is available, or %0 if the SID was
1625 * computed successfully.
1626 */
1627 int security_change_sid(u32 ssid,
1628 u32 tsid,
1629 u16 tclass,
1630 u32 *out_sid)
1631 {
1632 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1633 out_sid, false);
1634 }
1635
1636 /* Clone the SID into the new SID table. */
1637 static int clone_sid(u32 sid,
1638 struct context *context,
1639 void *arg)
1640 {
1641 struct sidtab *s = arg;
1642
1643 if (sid > SECINITSID_NUM)
1644 return sidtab_insert(s, sid, context);
1645 else
1646 return 0;
1647 }
1648
1649 static inline int convert_context_handle_invalid_context(struct context *context)
1650 {
1651 char *s;
1652 u32 len;
1653
1654 if (selinux_enforcing)
1655 return -EINVAL;
1656
1657 if (!context_struct_to_string(context, &s, &len)) {
1658 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1659 kfree(s);
1660 }
1661 return 0;
1662 }
1663
1664 struct convert_context_args {
1665 struct policydb *oldp;
1666 struct policydb *newp;
1667 };
1668
1669 /*
1670 * Convert the values in the security context
1671 * structure `c' from the values specified
1672 * in the policy `p->oldp' to the values specified
1673 * in the policy `p->newp'. Verify that the
1674 * context is valid under the new policy.
1675 */
1676 static int convert_context(u32 key,
1677 struct context *c,
1678 void *p)
1679 {
1680 struct convert_context_args *args;
1681 struct context oldc;
1682 struct ocontext *oc;
1683 struct mls_range *range;
1684 struct role_datum *role;
1685 struct type_datum *typdatum;
1686 struct user_datum *usrdatum;
1687 char *s;
1688 u32 len;
1689 int rc = 0;
1690
1691 if (key <= SECINITSID_NUM)
1692 goto out;
1693
1694 args = p;
1695
1696 if (c->str) {
1697 struct context ctx;
1698
1699 rc = -ENOMEM;
1700 s = kstrdup(c->str, GFP_KERNEL);
1701 if (!s)
1702 goto out;
1703
1704 rc = string_to_context_struct(args->newp, NULL, s,
1705 c->len, &ctx, SECSID_NULL);
1706 kfree(s);
1707 if (!rc) {
1708 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1709 c->str);
1710 /* Replace string with mapped representation. */
1711 kfree(c->str);
1712 memcpy(c, &ctx, sizeof(*c));
1713 goto out;
1714 } else if (rc == -EINVAL) {
1715 /* Retain string representation for later mapping. */
1716 rc = 0;
1717 goto out;
1718 } else {
1719 /* Other error condition, e.g. ENOMEM. */
1720 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1721 c->str, -rc);
1722 goto out;
1723 }
1724 }
1725
1726 rc = context_cpy(&oldc, c);
1727 if (rc)
1728 goto out;
1729
1730 /* Convert the user. */
1731 rc = -EINVAL;
1732 usrdatum = hashtab_search(args->newp->p_users.table,
1733 sym_name(args->oldp, SYM_USERS, c->user - 1));
1734 if (!usrdatum)
1735 goto bad;
1736 c->user = usrdatum->value;
1737
1738 /* Convert the role. */
1739 rc = -EINVAL;
1740 role = hashtab_search(args->newp->p_roles.table,
1741 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1742 if (!role)
1743 goto bad;
1744 c->role = role->value;
1745
1746 /* Convert the type. */
1747 rc = -EINVAL;
1748 typdatum = hashtab_search(args->newp->p_types.table,
1749 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1750 if (!typdatum)
1751 goto bad;
1752 c->type = typdatum->value;
1753
1754 /* Convert the MLS fields if dealing with MLS policies */
1755 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1756 rc = mls_convert_context(args->oldp, args->newp, c);
1757 if (rc)
1758 goto bad;
1759 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1760 /*
1761 * Switching between MLS and non-MLS policy:
1762 * free any storage used by the MLS fields in the
1763 * context for all existing entries in the sidtab.
1764 */
1765 mls_context_destroy(c);
1766 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1767 /*
1768 * Switching between non-MLS and MLS policy:
1769 * ensure that the MLS fields of the context for all
1770 * existing entries in the sidtab are filled in with a
1771 * suitable default value, likely taken from one of the
1772 * initial SIDs.
1773 */
1774 oc = args->newp->ocontexts[OCON_ISID];
1775 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1776 oc = oc->next;
1777 rc = -EINVAL;
1778 if (!oc) {
1779 printk(KERN_ERR "SELinux: unable to look up"
1780 " the initial SIDs list\n");
1781 goto bad;
1782 }
1783 range = &oc->context[0].range;
1784 rc = mls_range_set(c, range);
1785 if (rc)
1786 goto bad;
1787 }
1788
1789 /* Check the validity of the new context. */
1790 if (!policydb_context_isvalid(args->newp, c)) {
1791 rc = convert_context_handle_invalid_context(&oldc);
1792 if (rc)
1793 goto bad;
1794 }
1795
1796 context_destroy(&oldc);
1797
1798 rc = 0;
1799 out:
1800 return rc;
1801 bad:
1802 /* Map old representation to string and save it. */
1803 rc = context_struct_to_string(&oldc, &s, &len);
1804 if (rc)
1805 return rc;
1806 context_destroy(&oldc);
1807 context_destroy(c);
1808 c->str = s;
1809 c->len = len;
1810 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1811 c->str);
1812 rc = 0;
1813 goto out;
1814 }
1815
1816 static void security_load_policycaps(void)
1817 {
1818 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1819 POLICYDB_CAPABILITY_NETPEER);
1820 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1821 POLICYDB_CAPABILITY_OPENPERM);
1822 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1823 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1824 }
1825
1826 static int security_preserve_bools(struct policydb *p);
1827
1828 /**
1829 * security_load_policy - Load a security policy configuration.
1830 * @data: binary policy data
1831 * @len: length of data in bytes
1832 *
1833 * Load a new set of security policy configuration data,
1834 * validate it and convert the SID table as necessary.
1835 * This function will flush the access vector cache after
1836 * loading the new policy.
1837 */
1838 int security_load_policy(void *data, size_t len)
1839 {
1840 struct policydb *oldpolicydb, *newpolicydb;
1841 struct sidtab oldsidtab, newsidtab;
1842 struct selinux_mapping *oldmap, *map = NULL;
1843 struct convert_context_args args;
1844 u32 seqno;
1845 u16 map_size;
1846 int rc = 0;
1847 struct policy_file file = { data, len }, *fp = &file;
1848
1849 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
1850 if (!oldpolicydb) {
1851 rc = -ENOMEM;
1852 goto out;
1853 }
1854 newpolicydb = oldpolicydb + 1;
1855
1856 if (!ss_initialized) {
1857 avtab_cache_init();
1858 rc = policydb_read(&policydb, fp);
1859 if (rc) {
1860 avtab_cache_destroy();
1861 goto out;
1862 }
1863
1864 policydb.len = len;
1865 rc = selinux_set_mapping(&policydb, secclass_map,
1866 &current_mapping,
1867 &current_mapping_size);
1868 if (rc) {
1869 policydb_destroy(&policydb);
1870 avtab_cache_destroy();
1871 goto out;
1872 }
1873
1874 rc = policydb_load_isids(&policydb, &sidtab);
1875 if (rc) {
1876 policydb_destroy(&policydb);
1877 avtab_cache_destroy();
1878 goto out;
1879 }
1880
1881 security_load_policycaps();
1882 ss_initialized = 1;
1883 seqno = ++latest_granting;
1884 selinux_complete_init();
1885 avc_ss_reset(seqno);
1886 selnl_notify_policyload(seqno);
1887 selinux_status_update_policyload(seqno);
1888 selinux_netlbl_cache_invalidate();
1889 selinux_xfrm_notify_policyload();
1890 goto out;
1891 }
1892
1893 #if 0
1894 sidtab_hash_eval(&sidtab, "sids");
1895 #endif
1896
1897 rc = policydb_read(newpolicydb, fp);
1898 if (rc)
1899 goto out;
1900
1901 newpolicydb->len = len;
1902 /* If switching between different policy types, log MLS status */
1903 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
1904 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1905 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
1906 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1907
1908 rc = policydb_load_isids(newpolicydb, &newsidtab);
1909 if (rc) {
1910 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1911 policydb_destroy(newpolicydb);
1912 goto out;
1913 }
1914
1915 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
1916 if (rc)
1917 goto err;
1918
1919 rc = security_preserve_bools(newpolicydb);
1920 if (rc) {
1921 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1922 goto err;
1923 }
1924
1925 /* Clone the SID table. */
1926 sidtab_shutdown(&sidtab);
1927
1928 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1929 if (rc)
1930 goto err;
1931
1932 /*
1933 * Convert the internal representations of contexts
1934 * in the new SID table.
1935 */
1936 args.oldp = &policydb;
1937 args.newp = newpolicydb;
1938 rc = sidtab_map(&newsidtab, convert_context, &args);
1939 if (rc) {
1940 printk(KERN_ERR "SELinux: unable to convert the internal"
1941 " representation of contexts in the new SID"
1942 " table\n");
1943 goto err;
1944 }
1945
1946 /* Save the old policydb and SID table to free later. */
1947 memcpy(oldpolicydb, &policydb, sizeof(policydb));
1948 sidtab_set(&oldsidtab, &sidtab);
1949
1950 /* Install the new policydb and SID table. */
1951 write_lock_irq(&policy_rwlock);
1952 memcpy(&policydb, newpolicydb, sizeof(policydb));
1953 sidtab_set(&sidtab, &newsidtab);
1954 security_load_policycaps();
1955 oldmap = current_mapping;
1956 current_mapping = map;
1957 current_mapping_size = map_size;
1958 seqno = ++latest_granting;
1959 write_unlock_irq(&policy_rwlock);
1960
1961 /* Free the old policydb and SID table. */
1962 policydb_destroy(oldpolicydb);
1963 sidtab_destroy(&oldsidtab);
1964 kfree(oldmap);
1965
1966 avc_ss_reset(seqno);
1967 selnl_notify_policyload(seqno);
1968 selinux_status_update_policyload(seqno);
1969 selinux_netlbl_cache_invalidate();
1970 selinux_xfrm_notify_policyload();
1971
1972 rc = 0;
1973 goto out;
1974
1975 err:
1976 kfree(map);
1977 sidtab_destroy(&newsidtab);
1978 policydb_destroy(newpolicydb);
1979
1980 out:
1981 kfree(oldpolicydb);
1982 return rc;
1983 }
1984
1985 size_t security_policydb_len(void)
1986 {
1987 size_t len;
1988
1989 read_lock(&policy_rwlock);
1990 len = policydb.len;
1991 read_unlock(&policy_rwlock);
1992
1993 return len;
1994 }
1995
1996 /**
1997 * security_port_sid - Obtain the SID for a port.
1998 * @protocol: protocol number
1999 * @port: port number
2000 * @out_sid: security identifier
2001 */
2002 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2003 {
2004 struct ocontext *c;
2005 int rc = 0;
2006
2007 read_lock(&policy_rwlock);
2008
2009 c = policydb.ocontexts[OCON_PORT];
2010 while (c) {
2011 if (c->u.port.protocol == protocol &&
2012 c->u.port.low_port <= port &&
2013 c->u.port.high_port >= port)
2014 break;
2015 c = c->next;
2016 }
2017
2018 if (c) {
2019 if (!c->sid[0]) {
2020 rc = sidtab_context_to_sid(&sidtab,
2021 &c->context[0],
2022 &c->sid[0]);
2023 if (rc)
2024 goto out;
2025 }
2026 *out_sid = c->sid[0];
2027 } else {
2028 *out_sid = SECINITSID_PORT;
2029 }
2030
2031 out:
2032 read_unlock(&policy_rwlock);
2033 return rc;
2034 }
2035
2036 /**
2037 * security_netif_sid - Obtain the SID for a network interface.
2038 * @name: interface name
2039 * @if_sid: interface SID
2040 */
2041 int security_netif_sid(char *name, u32 *if_sid)
2042 {
2043 int rc = 0;
2044 struct ocontext *c;
2045
2046 read_lock(&policy_rwlock);
2047
2048 c = policydb.ocontexts[OCON_NETIF];
2049 while (c) {
2050 if (strcmp(name, c->u.name) == 0)
2051 break;
2052 c = c->next;
2053 }
2054
2055 if (c) {
2056 if (!c->sid[0] || !c->sid[1]) {
2057 rc = sidtab_context_to_sid(&sidtab,
2058 &c->context[0],
2059 &c->sid[0]);
2060 if (rc)
2061 goto out;
2062 rc = sidtab_context_to_sid(&sidtab,
2063 &c->context[1],
2064 &c->sid[1]);
2065 if (rc)
2066 goto out;
2067 }
2068 *if_sid = c->sid[0];
2069 } else
2070 *if_sid = SECINITSID_NETIF;
2071
2072 out:
2073 read_unlock(&policy_rwlock);
2074 return rc;
2075 }
2076
2077 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2078 {
2079 int i, fail = 0;
2080
2081 for (i = 0; i < 4; i++)
2082 if (addr[i] != (input[i] & mask[i])) {
2083 fail = 1;
2084 break;
2085 }
2086
2087 return !fail;
2088 }
2089
2090 /**
2091 * security_node_sid - Obtain the SID for a node (host).
2092 * @domain: communication domain aka address family
2093 * @addrp: address
2094 * @addrlen: address length in bytes
2095 * @out_sid: security identifier
2096 */
2097 int security_node_sid(u16 domain,
2098 void *addrp,
2099 u32 addrlen,
2100 u32 *out_sid)
2101 {
2102 int rc;
2103 struct ocontext *c;
2104
2105 read_lock(&policy_rwlock);
2106
2107 switch (domain) {
2108 case AF_INET: {
2109 u32 addr;
2110
2111 rc = -EINVAL;
2112 if (addrlen != sizeof(u32))
2113 goto out;
2114
2115 addr = *((u32 *)addrp);
2116
2117 c = policydb.ocontexts[OCON_NODE];
2118 while (c) {
2119 if (c->u.node.addr == (addr & c->u.node.mask))
2120 break;
2121 c = c->next;
2122 }
2123 break;
2124 }
2125
2126 case AF_INET6:
2127 rc = -EINVAL;
2128 if (addrlen != sizeof(u64) * 2)
2129 goto out;
2130 c = policydb.ocontexts[OCON_NODE6];
2131 while (c) {
2132 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2133 c->u.node6.mask))
2134 break;
2135 c = c->next;
2136 }
2137 break;
2138
2139 default:
2140 rc = 0;
2141 *out_sid = SECINITSID_NODE;
2142 goto out;
2143 }
2144
2145 if (c) {
2146 if (!c->sid[0]) {
2147 rc = sidtab_context_to_sid(&sidtab,
2148 &c->context[0],
2149 &c->sid[0]);
2150 if (rc)
2151 goto out;
2152 }
2153 *out_sid = c->sid[0];
2154 } else {
2155 *out_sid = SECINITSID_NODE;
2156 }
2157
2158 rc = 0;
2159 out:
2160 read_unlock(&policy_rwlock);
2161 return rc;
2162 }
2163
2164 #define SIDS_NEL 25
2165
2166 /**
2167 * security_get_user_sids - Obtain reachable SIDs for a user.
2168 * @fromsid: starting SID
2169 * @username: username
2170 * @sids: array of reachable SIDs for user
2171 * @nel: number of elements in @sids
2172 *
2173 * Generate the set of SIDs for legal security contexts
2174 * for a given user that can be reached by @fromsid.
2175 * Set *@sids to point to a dynamically allocated
2176 * array containing the set of SIDs. Set *@nel to the
2177 * number of elements in the array.
2178 */
2179
2180 int security_get_user_sids(u32 fromsid,
2181 char *username,
2182 u32 **sids,
2183 u32 *nel)
2184 {
2185 struct context *fromcon, usercon;
2186 u32 *mysids = NULL, *mysids2, sid;
2187 u32 mynel = 0, maxnel = SIDS_NEL;
2188 struct user_datum *user;
2189 struct role_datum *role;
2190 struct ebitmap_node *rnode, *tnode;
2191 int rc = 0, i, j;
2192
2193 *sids = NULL;
2194 *nel = 0;
2195
2196 if (!ss_initialized)
2197 goto out;
2198
2199 read_lock(&policy_rwlock);
2200
2201 context_init(&usercon);
2202
2203 rc = -EINVAL;
2204 fromcon = sidtab_search(&sidtab, fromsid);
2205 if (!fromcon)
2206 goto out_unlock;
2207
2208 rc = -EINVAL;
2209 user = hashtab_search(policydb.p_users.table, username);
2210 if (!user)
2211 goto out_unlock;
2212
2213 usercon.user = user->value;
2214
2215 rc = -ENOMEM;
2216 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2217 if (!mysids)
2218 goto out_unlock;
2219
2220 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2221 role = policydb.role_val_to_struct[i];
2222 usercon.role = i + 1;
2223 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2224 usercon.type = j + 1;
2225
2226 if (mls_setup_user_range(fromcon, user, &usercon))
2227 continue;
2228
2229 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2230 if (rc)
2231 goto out_unlock;
2232 if (mynel < maxnel) {
2233 mysids[mynel++] = sid;
2234 } else {
2235 rc = -ENOMEM;
2236 maxnel += SIDS_NEL;
2237 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2238 if (!mysids2)
2239 goto out_unlock;
2240 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2241 kfree(mysids);
2242 mysids = mysids2;
2243 mysids[mynel++] = sid;
2244 }
2245 }
2246 }
2247 rc = 0;
2248 out_unlock:
2249 read_unlock(&policy_rwlock);
2250 if (rc || !mynel) {
2251 kfree(mysids);
2252 goto out;
2253 }
2254
2255 rc = -ENOMEM;
2256 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2257 if (!mysids2) {
2258 kfree(mysids);
2259 goto out;
2260 }
2261 for (i = 0, j = 0; i < mynel; i++) {
2262 struct av_decision dummy_avd;
2263 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2264 SECCLASS_PROCESS, /* kernel value */
2265 PROCESS__TRANSITION, AVC_STRICT,
2266 &dummy_avd);
2267 if (!rc)
2268 mysids2[j++] = mysids[i];
2269 cond_resched();
2270 }
2271 rc = 0;
2272 kfree(mysids);
2273 *sids = mysids2;
2274 *nel = j;
2275 out:
2276 return rc;
2277 }
2278
2279 /**
2280 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2281 * @fstype: filesystem type
2282 * @path: path from root of mount
2283 * @sclass: file security class
2284 * @sid: SID for path
2285 *
2286 * Obtain a SID to use for a file in a filesystem that
2287 * cannot support xattr or use a fixed labeling behavior like
2288 * transition SIDs or task SIDs.
2289 *
2290 * The caller must acquire the policy_rwlock before calling this function.
2291 */
2292 static inline int __security_genfs_sid(const char *fstype,
2293 char *path,
2294 u16 orig_sclass,
2295 u32 *sid)
2296 {
2297 int len;
2298 u16 sclass;
2299 struct genfs *genfs;
2300 struct ocontext *c;
2301 int rc, cmp = 0;
2302
2303 while (path[0] == '/' && path[1] == '/')
2304 path++;
2305
2306 sclass = unmap_class(orig_sclass);
2307 *sid = SECINITSID_UNLABELED;
2308
2309 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2310 cmp = strcmp(fstype, genfs->fstype);
2311 if (cmp <= 0)
2312 break;
2313 }
2314
2315 rc = -ENOENT;
2316 if (!genfs || cmp)
2317 goto out;
2318
2319 for (c = genfs->head; c; c = c->next) {
2320 len = strlen(c->u.name);
2321 if ((!c->v.sclass || sclass == c->v.sclass) &&
2322 (strncmp(c->u.name, path, len) == 0))
2323 break;
2324 }
2325
2326 rc = -ENOENT;
2327 if (!c)
2328 goto out;
2329
2330 if (!c->sid[0]) {
2331 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2332 if (rc)
2333 goto out;
2334 }
2335
2336 *sid = c->sid[0];
2337 rc = 0;
2338 out:
2339 return rc;
2340 }
2341
2342 /**
2343 * security_genfs_sid - Obtain a SID for a file in a filesystem
2344 * @fstype: filesystem type
2345 * @path: path from root of mount
2346 * @sclass: file security class
2347 * @sid: SID for path
2348 *
2349 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2350 * it afterward.
2351 */
2352 int security_genfs_sid(const char *fstype,
2353 char *path,
2354 u16 orig_sclass,
2355 u32 *sid)
2356 {
2357 int retval;
2358
2359 read_lock(&policy_rwlock);
2360 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2361 read_unlock(&policy_rwlock);
2362 return retval;
2363 }
2364
2365 /**
2366 * security_fs_use - Determine how to handle labeling for a filesystem.
2367 * @sb: superblock in question
2368 */
2369 int security_fs_use(struct super_block *sb)
2370 {
2371 int rc = 0;
2372 struct ocontext *c;
2373 struct superblock_security_struct *sbsec = sb->s_security;
2374 const char *fstype = sb->s_type->name;
2375
2376 read_lock(&policy_rwlock);
2377
2378 c = policydb.ocontexts[OCON_FSUSE];
2379 while (c) {
2380 if (strcmp(fstype, c->u.name) == 0)
2381 break;
2382 c = c->next;
2383 }
2384
2385 if (c) {
2386 sbsec->behavior = c->v.behavior;
2387 if (!c->sid[0]) {
2388 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2389 &c->sid[0]);
2390 if (rc)
2391 goto out;
2392 }
2393 sbsec->sid = c->sid[0];
2394 } else {
2395 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2396 &sbsec->sid);
2397 if (rc) {
2398 sbsec->behavior = SECURITY_FS_USE_NONE;
2399 rc = 0;
2400 } else {
2401 sbsec->behavior = SECURITY_FS_USE_GENFS;
2402 }
2403 }
2404
2405 out:
2406 read_unlock(&policy_rwlock);
2407 return rc;
2408 }
2409
2410 int security_get_bools(int *len, char ***names, int **values)
2411 {
2412 int i, rc;
2413
2414 read_lock(&policy_rwlock);
2415 *names = NULL;
2416 *values = NULL;
2417
2418 rc = 0;
2419 *len = policydb.p_bools.nprim;
2420 if (!*len)
2421 goto out;
2422
2423 rc = -ENOMEM;
2424 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2425 if (!*names)
2426 goto err;
2427
2428 rc = -ENOMEM;
2429 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2430 if (!*values)
2431 goto err;
2432
2433 for (i = 0; i < *len; i++) {
2434 size_t name_len;
2435
2436 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2437 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2438
2439 rc = -ENOMEM;
2440 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2441 if (!(*names)[i])
2442 goto err;
2443
2444 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2445 (*names)[i][name_len - 1] = 0;
2446 }
2447 rc = 0;
2448 out:
2449 read_unlock(&policy_rwlock);
2450 return rc;
2451 err:
2452 if (*names) {
2453 for (i = 0; i < *len; i++)
2454 kfree((*names)[i]);
2455 }
2456 kfree(*values);
2457 goto out;
2458 }
2459
2460
2461 int security_set_bools(int len, int *values)
2462 {
2463 int i, rc;
2464 int lenp, seqno = 0;
2465 struct cond_node *cur;
2466
2467 write_lock_irq(&policy_rwlock);
2468
2469 rc = -EFAULT;
2470 lenp = policydb.p_bools.nprim;
2471 if (len != lenp)
2472 goto out;
2473
2474 for (i = 0; i < len; i++) {
2475 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2476 audit_log(current->audit_context, GFP_ATOMIC,
2477 AUDIT_MAC_CONFIG_CHANGE,
2478 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2479 sym_name(&policydb, SYM_BOOLS, i),
2480 !!values[i],
2481 policydb.bool_val_to_struct[i]->state,
2482 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2483 audit_get_sessionid(current));
2484 }
2485 if (values[i])
2486 policydb.bool_val_to_struct[i]->state = 1;
2487 else
2488 policydb.bool_val_to_struct[i]->state = 0;
2489 }
2490
2491 for (cur = policydb.cond_list; cur; cur = cur->next) {
2492 rc = evaluate_cond_node(&policydb, cur);
2493 if (rc)
2494 goto out;
2495 }
2496
2497 seqno = ++latest_granting;
2498 rc = 0;
2499 out:
2500 write_unlock_irq(&policy_rwlock);
2501 if (!rc) {
2502 avc_ss_reset(seqno);
2503 selnl_notify_policyload(seqno);
2504 selinux_status_update_policyload(seqno);
2505 selinux_xfrm_notify_policyload();
2506 }
2507 return rc;
2508 }
2509
2510 int security_get_bool_value(int bool)
2511 {
2512 int rc;
2513 int len;
2514
2515 read_lock(&policy_rwlock);
2516
2517 rc = -EFAULT;
2518 len = policydb.p_bools.nprim;
2519 if (bool >= len)
2520 goto out;
2521
2522 rc = policydb.bool_val_to_struct[bool]->state;
2523 out:
2524 read_unlock(&policy_rwlock);
2525 return rc;
2526 }
2527
2528 static int security_preserve_bools(struct policydb *p)
2529 {
2530 int rc, nbools = 0, *bvalues = NULL, i;
2531 char **bnames = NULL;
2532 struct cond_bool_datum *booldatum;
2533 struct cond_node *cur;
2534
2535 rc = security_get_bools(&nbools, &bnames, &bvalues);
2536 if (rc)
2537 goto out;
2538 for (i = 0; i < nbools; i++) {
2539 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2540 if (booldatum)
2541 booldatum->state = bvalues[i];
2542 }
2543 for (cur = p->cond_list; cur; cur = cur->next) {
2544 rc = evaluate_cond_node(p, cur);
2545 if (rc)
2546 goto out;
2547 }
2548
2549 out:
2550 if (bnames) {
2551 for (i = 0; i < nbools; i++)
2552 kfree(bnames[i]);
2553 }
2554 kfree(bnames);
2555 kfree(bvalues);
2556 return rc;
2557 }
2558
2559 /*
2560 * security_sid_mls_copy() - computes a new sid based on the given
2561 * sid and the mls portion of mls_sid.
2562 */
2563 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2564 {
2565 struct context *context1;
2566 struct context *context2;
2567 struct context newcon;
2568 char *s;
2569 u32 len;
2570 int rc;
2571
2572 rc = 0;
2573 if (!ss_initialized || !policydb.mls_enabled) {
2574 *new_sid = sid;
2575 goto out;
2576 }
2577
2578 context_init(&newcon);
2579
2580 read_lock(&policy_rwlock);
2581
2582 rc = -EINVAL;
2583 context1 = sidtab_search(&sidtab, sid);
2584 if (!context1) {
2585 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2586 __func__, sid);
2587 goto out_unlock;
2588 }
2589
2590 rc = -EINVAL;
2591 context2 = sidtab_search(&sidtab, mls_sid);
2592 if (!context2) {
2593 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2594 __func__, mls_sid);
2595 goto out_unlock;
2596 }
2597
2598 newcon.user = context1->user;
2599 newcon.role = context1->role;
2600 newcon.type = context1->type;
2601 rc = mls_context_cpy(&newcon, context2);
2602 if (rc)
2603 goto out_unlock;
2604
2605 /* Check the validity of the new context. */
2606 if (!policydb_context_isvalid(&policydb, &newcon)) {
2607 rc = convert_context_handle_invalid_context(&newcon);
2608 if (rc) {
2609 if (!context_struct_to_string(&newcon, &s, &len)) {
2610 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2611 "security_sid_mls_copy: invalid context %s", s);
2612 kfree(s);
2613 }
2614 goto out_unlock;
2615 }
2616 }
2617
2618 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2619 out_unlock:
2620 read_unlock(&policy_rwlock);
2621 context_destroy(&newcon);
2622 out:
2623 return rc;
2624 }
2625
2626 /**
2627 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2628 * @nlbl_sid: NetLabel SID
2629 * @nlbl_type: NetLabel labeling protocol type
2630 * @xfrm_sid: XFRM SID
2631 *
2632 * Description:
2633 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2634 * resolved into a single SID it is returned via @peer_sid and the function
2635 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2636 * returns a negative value. A table summarizing the behavior is below:
2637 *
2638 * | function return | @sid
2639 * ------------------------------+-----------------+-----------------
2640 * no peer labels | 0 | SECSID_NULL
2641 * single peer label | 0 | <peer_label>
2642 * multiple, consistent labels | 0 | <peer_label>
2643 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2644 *
2645 */
2646 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2647 u32 xfrm_sid,
2648 u32 *peer_sid)
2649 {
2650 int rc;
2651 struct context *nlbl_ctx;
2652 struct context *xfrm_ctx;
2653
2654 *peer_sid = SECSID_NULL;
2655
2656 /* handle the common (which also happens to be the set of easy) cases
2657 * right away, these two if statements catch everything involving a
2658 * single or absent peer SID/label */
2659 if (xfrm_sid == SECSID_NULL) {
2660 *peer_sid = nlbl_sid;
2661 return 0;
2662 }
2663 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2664 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2665 * is present */
2666 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2667 *peer_sid = xfrm_sid;
2668 return 0;
2669 }
2670
2671 /* we don't need to check ss_initialized here since the only way both
2672 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2673 * security server was initialized and ss_initialized was true */
2674 if (!policydb.mls_enabled)
2675 return 0;
2676
2677 read_lock(&policy_rwlock);
2678
2679 rc = -EINVAL;
2680 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2681 if (!nlbl_ctx) {
2682 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2683 __func__, nlbl_sid);
2684 goto out;
2685 }
2686 rc = -EINVAL;
2687 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2688 if (!xfrm_ctx) {
2689 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2690 __func__, xfrm_sid);
2691 goto out;
2692 }
2693 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2694 if (rc)
2695 goto out;
2696
2697 /* at present NetLabel SIDs/labels really only carry MLS
2698 * information so if the MLS portion of the NetLabel SID
2699 * matches the MLS portion of the labeled XFRM SID/label
2700 * then pass along the XFRM SID as it is the most
2701 * expressive */
2702 *peer_sid = xfrm_sid;
2703 out:
2704 read_unlock(&policy_rwlock);
2705 return rc;
2706 }
2707
2708 static int get_classes_callback(void *k, void *d, void *args)
2709 {
2710 struct class_datum *datum = d;
2711 char *name = k, **classes = args;
2712 int value = datum->value - 1;
2713
2714 classes[value] = kstrdup(name, GFP_ATOMIC);
2715 if (!classes[value])
2716 return -ENOMEM;
2717
2718 return 0;
2719 }
2720
2721 int security_get_classes(char ***classes, int *nclasses)
2722 {
2723 int rc;
2724
2725 read_lock(&policy_rwlock);
2726
2727 rc = -ENOMEM;
2728 *nclasses = policydb.p_classes.nprim;
2729 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2730 if (!*classes)
2731 goto out;
2732
2733 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2734 *classes);
2735 if (rc) {
2736 int i;
2737 for (i = 0; i < *nclasses; i++)
2738 kfree((*classes)[i]);
2739 kfree(*classes);
2740 }
2741
2742 out:
2743 read_unlock(&policy_rwlock);
2744 return rc;
2745 }
2746
2747 static int get_permissions_callback(void *k, void *d, void *args)
2748 {
2749 struct perm_datum *datum = d;
2750 char *name = k, **perms = args;
2751 int value = datum->value - 1;
2752
2753 perms[value] = kstrdup(name, GFP_ATOMIC);
2754 if (!perms[value])
2755 return -ENOMEM;
2756
2757 return 0;
2758 }
2759
2760 int security_get_permissions(char *class, char ***perms, int *nperms)
2761 {
2762 int rc, i;
2763 struct class_datum *match;
2764
2765 read_lock(&policy_rwlock);
2766
2767 rc = -EINVAL;
2768 match = hashtab_search(policydb.p_classes.table, class);
2769 if (!match) {
2770 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2771 __func__, class);
2772 goto out;
2773 }
2774
2775 rc = -ENOMEM;
2776 *nperms = match->permissions.nprim;
2777 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2778 if (!*perms)
2779 goto out;
2780
2781 if (match->comdatum) {
2782 rc = hashtab_map(match->comdatum->permissions.table,
2783 get_permissions_callback, *perms);
2784 if (rc)
2785 goto err;
2786 }
2787
2788 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2789 *perms);
2790 if (rc)
2791 goto err;
2792
2793 out:
2794 read_unlock(&policy_rwlock);
2795 return rc;
2796
2797 err:
2798 read_unlock(&policy_rwlock);
2799 for (i = 0; i < *nperms; i++)
2800 kfree((*perms)[i]);
2801 kfree(*perms);
2802 return rc;
2803 }
2804
2805 int security_get_reject_unknown(void)
2806 {
2807 return policydb.reject_unknown;
2808 }
2809
2810 int security_get_allow_unknown(void)
2811 {
2812 return policydb.allow_unknown;
2813 }
2814
2815 /**
2816 * security_policycap_supported - Check for a specific policy capability
2817 * @req_cap: capability
2818 *
2819 * Description:
2820 * This function queries the currently loaded policy to see if it supports the
2821 * capability specified by @req_cap. Returns true (1) if the capability is
2822 * supported, false (0) if it isn't supported.
2823 *
2824 */
2825 int security_policycap_supported(unsigned int req_cap)
2826 {
2827 int rc;
2828
2829 read_lock(&policy_rwlock);
2830 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2831 read_unlock(&policy_rwlock);
2832
2833 return rc;
2834 }
2835
2836 struct selinux_audit_rule {
2837 u32 au_seqno;
2838 struct context au_ctxt;
2839 };
2840
2841 void selinux_audit_rule_free(void *vrule)
2842 {
2843 struct selinux_audit_rule *rule = vrule;
2844
2845 if (rule) {
2846 context_destroy(&rule->au_ctxt);
2847 kfree(rule);
2848 }
2849 }
2850
2851 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2852 {
2853 struct selinux_audit_rule *tmprule;
2854 struct role_datum *roledatum;
2855 struct type_datum *typedatum;
2856 struct user_datum *userdatum;
2857 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2858 int rc = 0;
2859
2860 *rule = NULL;
2861
2862 if (!ss_initialized)
2863 return -EOPNOTSUPP;
2864
2865 switch (field) {
2866 case AUDIT_SUBJ_USER:
2867 case AUDIT_SUBJ_ROLE:
2868 case AUDIT_SUBJ_TYPE:
2869 case AUDIT_OBJ_USER:
2870 case AUDIT_OBJ_ROLE:
2871 case AUDIT_OBJ_TYPE:
2872 /* only 'equals' and 'not equals' fit user, role, and type */
2873 if (op != Audit_equal && op != Audit_not_equal)
2874 return -EINVAL;
2875 break;
2876 case AUDIT_SUBJ_SEN:
2877 case AUDIT_SUBJ_CLR:
2878 case AUDIT_OBJ_LEV_LOW:
2879 case AUDIT_OBJ_LEV_HIGH:
2880 /* we do not allow a range, indicated by the presence of '-' */
2881 if (strchr(rulestr, '-'))
2882 return -EINVAL;
2883 break;
2884 default:
2885 /* only the above fields are valid */
2886 return -EINVAL;
2887 }
2888
2889 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2890 if (!tmprule)
2891 return -ENOMEM;
2892
2893 context_init(&tmprule->au_ctxt);
2894
2895 read_lock(&policy_rwlock);
2896
2897 tmprule->au_seqno = latest_granting;
2898
2899 switch (field) {
2900 case AUDIT_SUBJ_USER:
2901 case AUDIT_OBJ_USER:
2902 rc = -EINVAL;
2903 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2904 if (!userdatum)
2905 goto out;
2906 tmprule->au_ctxt.user = userdatum->value;
2907 break;
2908 case AUDIT_SUBJ_ROLE:
2909 case AUDIT_OBJ_ROLE:
2910 rc = -EINVAL;
2911 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2912 if (!roledatum)
2913 goto out;
2914 tmprule->au_ctxt.role = roledatum->value;
2915 break;
2916 case AUDIT_SUBJ_TYPE:
2917 case AUDIT_OBJ_TYPE:
2918 rc = -EINVAL;
2919 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2920 if (!typedatum)
2921 goto out;
2922 tmprule->au_ctxt.type = typedatum->value;
2923 break;
2924 case AUDIT_SUBJ_SEN:
2925 case AUDIT_SUBJ_CLR:
2926 case AUDIT_OBJ_LEV_LOW:
2927 case AUDIT_OBJ_LEV_HIGH:
2928 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2929 if (rc)
2930 goto out;
2931 break;
2932 }
2933 rc = 0;
2934 out:
2935 read_unlock(&policy_rwlock);
2936
2937 if (rc) {
2938 selinux_audit_rule_free(tmprule);
2939 tmprule = NULL;
2940 }
2941
2942 *rule = tmprule;
2943
2944 return rc;
2945 }
2946
2947 /* Check to see if the rule contains any selinux fields */
2948 int selinux_audit_rule_known(struct audit_krule *rule)
2949 {
2950 int i;
2951
2952 for (i = 0; i < rule->field_count; i++) {
2953 struct audit_field *f = &rule->fields[i];
2954 switch (f->type) {
2955 case AUDIT_SUBJ_USER:
2956 case AUDIT_SUBJ_ROLE:
2957 case AUDIT_SUBJ_TYPE:
2958 case AUDIT_SUBJ_SEN:
2959 case AUDIT_SUBJ_CLR:
2960 case AUDIT_OBJ_USER:
2961 case AUDIT_OBJ_ROLE:
2962 case AUDIT_OBJ_TYPE:
2963 case AUDIT_OBJ_LEV_LOW:
2964 case AUDIT_OBJ_LEV_HIGH:
2965 return 1;
2966 }
2967 }
2968
2969 return 0;
2970 }
2971
2972 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2973 struct audit_context *actx)
2974 {
2975 struct context *ctxt;
2976 struct mls_level *level;
2977 struct selinux_audit_rule *rule = vrule;
2978 int match = 0;
2979
2980 if (unlikely(!rule)) {
2981 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
2982 return -ENOENT;
2983 }
2984
2985 read_lock(&policy_rwlock);
2986
2987 if (rule->au_seqno < latest_granting) {
2988 match = -ESTALE;
2989 goto out;
2990 }
2991
2992 ctxt = sidtab_search(&sidtab, sid);
2993 if (unlikely(!ctxt)) {
2994 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
2995 sid);
2996 match = -ENOENT;
2997 goto out;
2998 }
2999
3000 /* a field/op pair that is not caught here will simply fall through
3001 without a match */
3002 switch (field) {
3003 case AUDIT_SUBJ_USER:
3004 case AUDIT_OBJ_USER:
3005 switch (op) {
3006 case Audit_equal:
3007 match = (ctxt->user == rule->au_ctxt.user);
3008 break;
3009 case Audit_not_equal:
3010 match = (ctxt->user != rule->au_ctxt.user);
3011 break;
3012 }
3013 break;
3014 case AUDIT_SUBJ_ROLE:
3015 case AUDIT_OBJ_ROLE:
3016 switch (op) {
3017 case Audit_equal:
3018 match = (ctxt->role == rule->au_ctxt.role);
3019 break;
3020 case Audit_not_equal:
3021 match = (ctxt->role != rule->au_ctxt.role);
3022 break;
3023 }
3024 break;
3025 case AUDIT_SUBJ_TYPE:
3026 case AUDIT_OBJ_TYPE:
3027 switch (op) {
3028 case Audit_equal:
3029 match = (ctxt->type == rule->au_ctxt.type);
3030 break;
3031 case Audit_not_equal:
3032 match = (ctxt->type != rule->au_ctxt.type);
3033 break;
3034 }
3035 break;
3036 case AUDIT_SUBJ_SEN:
3037 case AUDIT_SUBJ_CLR:
3038 case AUDIT_OBJ_LEV_LOW:
3039 case AUDIT_OBJ_LEV_HIGH:
3040 level = ((field == AUDIT_SUBJ_SEN ||
3041 field == AUDIT_OBJ_LEV_LOW) ?
3042 &ctxt->range.level[0] : &ctxt->range.level[1]);
3043 switch (op) {
3044 case Audit_equal:
3045 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3046 level);
3047 break;
3048 case Audit_not_equal:
3049 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3050 level);
3051 break;
3052 case Audit_lt:
3053 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3054 level) &&
3055 !mls_level_eq(&rule->au_ctxt.range.level[0],
3056 level));
3057 break;
3058 case Audit_le:
3059 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3060 level);
3061 break;
3062 case Audit_gt:
3063 match = (mls_level_dom(level,
3064 &rule->au_ctxt.range.level[0]) &&
3065 !mls_level_eq(level,
3066 &rule->au_ctxt.range.level[0]));
3067 break;
3068 case Audit_ge:
3069 match = mls_level_dom(level,
3070 &rule->au_ctxt.range.level[0]);
3071 break;
3072 }
3073 }
3074
3075 out:
3076 read_unlock(&policy_rwlock);
3077 return match;
3078 }
3079
3080 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3081
3082 static int aurule_avc_callback(u32 event)
3083 {
3084 int err = 0;
3085
3086 if (event == AVC_CALLBACK_RESET && aurule_callback)
3087 err = aurule_callback();
3088 return err;
3089 }
3090
3091 static int __init aurule_init(void)
3092 {
3093 int err;
3094
3095 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3096 if (err)
3097 panic("avc_add_callback() failed, error %d\n", err);
3098
3099 return err;
3100 }
3101 __initcall(aurule_init);
3102
3103 #ifdef CONFIG_NETLABEL
3104 /**
3105 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3106 * @secattr: the NetLabel packet security attributes
3107 * @sid: the SELinux SID
3108 *
3109 * Description:
3110 * Attempt to cache the context in @ctx, which was derived from the packet in
3111 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3112 * already been initialized.
3113 *
3114 */
3115 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3116 u32 sid)
3117 {
3118 u32 *sid_cache;
3119
3120 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3121 if (sid_cache == NULL)
3122 return;
3123 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3124 if (secattr->cache == NULL) {
3125 kfree(sid_cache);
3126 return;
3127 }
3128
3129 *sid_cache = sid;
3130 secattr->cache->free = kfree;
3131 secattr->cache->data = sid_cache;
3132 secattr->flags |= NETLBL_SECATTR_CACHE;
3133 }
3134
3135 /**
3136 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3137 * @secattr: the NetLabel packet security attributes
3138 * @sid: the SELinux SID
3139 *
3140 * Description:
3141 * Convert the given NetLabel security attributes in @secattr into a
3142 * SELinux SID. If the @secattr field does not contain a full SELinux
3143 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3144 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3145 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3146 * conversion for future lookups. Returns zero on success, negative values on
3147 * failure.
3148 *
3149 */
3150 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3151 u32 *sid)
3152 {
3153 int rc;
3154 struct context *ctx;
3155 struct context ctx_new;
3156
3157 if (!ss_initialized) {
3158 *sid = SECSID_NULL;
3159 return 0;
3160 }
3161
3162 read_lock(&policy_rwlock);
3163
3164 if (secattr->flags & NETLBL_SECATTR_CACHE)
3165 *sid = *(u32 *)secattr->cache->data;
3166 else if (secattr->flags & NETLBL_SECATTR_SECID)
3167 *sid = secattr->attr.secid;
3168 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3169 rc = -EIDRM;
3170 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3171 if (ctx == NULL)
3172 goto out;
3173
3174 context_init(&ctx_new);
3175 ctx_new.user = ctx->user;
3176 ctx_new.role = ctx->role;
3177 ctx_new.type = ctx->type;
3178 mls_import_netlbl_lvl(&ctx_new, secattr);
3179 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3180 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3181 secattr->attr.mls.cat);
3182 if (rc)
3183 goto out;
3184 memcpy(&ctx_new.range.level[1].cat,
3185 &ctx_new.range.level[0].cat,
3186 sizeof(ctx_new.range.level[0].cat));
3187 }
3188 rc = -EIDRM;
3189 if (!mls_context_isvalid(&policydb, &ctx_new))
3190 goto out_free;
3191
3192 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3193 if (rc)
3194 goto out_free;
3195
3196 security_netlbl_cache_add(secattr, *sid);
3197
3198 ebitmap_destroy(&ctx_new.range.level[0].cat);
3199 } else
3200 *sid = SECSID_NULL;
3201
3202 read_unlock(&policy_rwlock);
3203 return 0;
3204 out_free:
3205 ebitmap_destroy(&ctx_new.range.level[0].cat);
3206 out:
3207 read_unlock(&policy_rwlock);
3208 return rc;
3209 }
3210
3211 /**
3212 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3213 * @sid: the SELinux SID
3214 * @secattr: the NetLabel packet security attributes
3215 *
3216 * Description:
3217 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3218 * Returns zero on success, negative values on failure.
3219 *
3220 */
3221 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3222 {
3223 int rc;
3224 struct context *ctx;
3225
3226 if (!ss_initialized)
3227 return 0;
3228
3229 read_lock(&policy_rwlock);
3230
3231 rc = -ENOENT;
3232 ctx = sidtab_search(&sidtab, sid);
3233 if (ctx == NULL)
3234 goto out;
3235
3236 rc = -ENOMEM;
3237 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3238 GFP_ATOMIC);
3239 if (secattr->domain == NULL)
3240 goto out;
3241
3242 secattr->attr.secid = sid;
3243 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3244 mls_export_netlbl_lvl(ctx, secattr);
3245 rc = mls_export_netlbl_cat(ctx, secattr);
3246 out:
3247 read_unlock(&policy_rwlock);
3248 return rc;
3249 }
3250 #endif /* CONFIG_NETLABEL */
3251
3252 /**
3253 * security_read_policy - read the policy.
3254 * @data: binary policy data
3255 * @len: length of data in bytes
3256 *
3257 */
3258 int security_read_policy(void **data, size_t *len)
3259 {
3260 int rc;
3261 struct policy_file fp;
3262
3263 if (!ss_initialized)
3264 return -EINVAL;
3265
3266 *len = security_policydb_len();
3267
3268 *data = vmalloc_user(*len);
3269 if (!*data)
3270 return -ENOMEM;
3271
3272 fp.data = *data;
3273 fp.len = *len;
3274
3275 read_lock(&policy_rwlock);
3276 rc = policydb_write(&policydb, &fp);
3277 read_unlock(&policy_rwlock);
3278
3279 if (rc)
3280 return rc;
3281
3282 *len = (unsigned long)fp.data - (unsigned long)*data;
3283 return 0;
3284
3285 }
Linux kernel - Deliverables
This page took 0.099079 seconds and 4 git commands to generate.