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x86/ftrace: Add stack frame pointer to ftrace_caller
[linux/fpc-iii.git] / security / selinux / ss / services.c
blobb4aa491a0a23d8e025f00fde82b317952816773f
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_extsockclass;
76 int selinux_policycap_alwaysnetwork;
77 int selinux_policycap_cgroupseclabel;
78
79 static DEFINE_RWLOCK(policy_rwlock);
80
81 static struct sidtab sidtab;
82 struct policydb policydb;
83 int ss_initialized;
84
85 /*
86 * The largest sequence number that has been used when
87 * providing an access decision to the access vector cache.
88 * The sequence number only changes when a policy change
89 * occurs.
90 */
91 static u32 latest_granting;
92
93 /* Forward declaration. */
94 static int context_struct_to_string(struct context *context, char **scontext,
95 u32 *scontext_len);
96
97 static void context_struct_compute_av(struct context *scontext,
98 struct context *tcontext,
99 u16 tclass,
100 struct av_decision *avd,
101 struct extended_perms *xperms);
102
103 struct selinux_mapping {
104 u16 value; /* policy value */
105 unsigned num_perms;
106 u32 perms[sizeof(u32) * 8];
107 };
108
109 static struct selinux_mapping *current_mapping;
110 static u16 current_mapping_size;
111
112 static int selinux_set_mapping(struct policydb *pol,
113 struct security_class_mapping *map,
114 struct selinux_mapping **out_map_p,
115 u16 *out_map_size)
116 {
117 struct selinux_mapping *out_map = NULL;
118 size_t size = sizeof(struct selinux_mapping);
119 u16 i, j;
120 unsigned k;
121 bool print_unknown_handle = false;
122
123 /* Find number of classes in the input mapping */
124 if (!map)
125 return -EINVAL;
126 i = 0;
127 while (map[i].name)
128 i++;
129
130 /* Allocate space for the class records, plus one for class zero */
131 out_map = kcalloc(++i, size, GFP_ATOMIC);
132 if (!out_map)
133 return -ENOMEM;
134
135 /* Store the raw class and permission values */
136 j = 0;
137 while (map[j].name) {
138 struct security_class_mapping *p_in = map + (j++);
139 struct selinux_mapping *p_out = out_map + j;
140
141 /* An empty class string skips ahead */
142 if (!strcmp(p_in->name, "")) {
143 p_out->num_perms = 0;
144 continue;
145 }
146
147 p_out->value = string_to_security_class(pol, p_in->name);
148 if (!p_out->value) {
149 printk(KERN_INFO
150 "SELinux: Class %s not defined in policy.\n",
151 p_in->name);
152 if (pol->reject_unknown)
153 goto err;
154 p_out->num_perms = 0;
155 print_unknown_handle = true;
156 continue;
157 }
158
159 k = 0;
160 while (p_in->perms && p_in->perms[k]) {
161 /* An empty permission string skips ahead */
162 if (!*p_in->perms[k]) {
163 k++;
164 continue;
165 }
166 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
167 p_in->perms[k]);
168 if (!p_out->perms[k]) {
169 printk(KERN_INFO
170 "SELinux: Permission %s in class %s not defined in policy.\n",
171 p_in->perms[k], p_in->name);
172 if (pol->reject_unknown)
173 goto err;
174 print_unknown_handle = true;
175 }
176
177 k++;
178 }
179 p_out->num_perms = k;
180 }
181
182 if (print_unknown_handle)
183 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
184 pol->allow_unknown ? "allowed" : "denied");
185
186 *out_map_p = out_map;
187 *out_map_size = i;
188 return 0;
189 err:
190 kfree(out_map);
191 return -EINVAL;
192 }
193
194 /*
195 * Get real, policy values from mapped values
196 */
197
198 static u16 unmap_class(u16 tclass)
199 {
200 if (tclass < current_mapping_size)
201 return current_mapping[tclass].value;
202
203 return tclass;
204 }
205
206 /*
207 * Get kernel value for class from its policy value
208 */
209 static u16 map_class(u16 pol_value)
210 {
211 u16 i;
212
213 for (i = 1; i < current_mapping_size; i++) {
214 if (current_mapping[i].value == pol_value)
215 return i;
216 }
217
218 return SECCLASS_NULL;
219 }
220
221 static void map_decision(u16 tclass, struct av_decision *avd,
222 int allow_unknown)
223 {
224 if (tclass < current_mapping_size) {
225 unsigned i, n = current_mapping[tclass].num_perms;
226 u32 result;
227
228 for (i = 0, result = 0; i < n; i++) {
229 if (avd->allowed & current_mapping[tclass].perms[i])
230 result |= 1<<i;
231 if (allow_unknown && !current_mapping[tclass].perms[i])
232 result |= 1<<i;
233 }
234 avd->allowed = result;
235
236 for (i = 0, result = 0; i < n; i++)
237 if (avd->auditallow & current_mapping[tclass].perms[i])
238 result |= 1<<i;
239 avd->auditallow = result;
240
241 for (i = 0, result = 0; i < n; i++) {
242 if (avd->auditdeny & current_mapping[tclass].perms[i])
243 result |= 1<<i;
244 if (!allow_unknown && !current_mapping[tclass].perms[i])
245 result |= 1<<i;
246 }
247 /*
248 * In case the kernel has a bug and requests a permission
249 * between num_perms and the maximum permission number, we
250 * should audit that denial
251 */
252 for (; i < (sizeof(u32)*8); i++)
253 result |= 1<<i;
254 avd->auditdeny = result;
255 }
256 }
257
258 int security_mls_enabled(void)
259 {
260 return policydb.mls_enabled;
261 }
262
263 /*
264 * Return the boolean value of a constraint expression
265 * when it is applied to the specified source and target
266 * security contexts.
267 *
268 * xcontext is a special beast... It is used by the validatetrans rules
269 * only. For these rules, scontext is the context before the transition,
270 * tcontext is the context after the transition, and xcontext is the context
271 * of the process performing the transition. All other callers of
272 * constraint_expr_eval should pass in NULL for xcontext.
273 */
274 static int constraint_expr_eval(struct context *scontext,
275 struct context *tcontext,
276 struct context *xcontext,
277 struct constraint_expr *cexpr)
278 {
279 u32 val1, val2;
280 struct context *c;
281 struct role_datum *r1, *r2;
282 struct mls_level *l1, *l2;
283 struct constraint_expr *e;
284 int s[CEXPR_MAXDEPTH];
285 int sp = -1;
286
287 for (e = cexpr; e; e = e->next) {
288 switch (e->expr_type) {
289 case CEXPR_NOT:
290 BUG_ON(sp < 0);
291 s[sp] = !s[sp];
292 break;
293 case CEXPR_AND:
294 BUG_ON(sp < 1);
295 sp--;
296 s[sp] &= s[sp + 1];
297 break;
298 case CEXPR_OR:
299 BUG_ON(sp < 1);
300 sp--;
301 s[sp] |= s[sp + 1];
302 break;
303 case CEXPR_ATTR:
304 if (sp == (CEXPR_MAXDEPTH - 1))
305 return 0;
306 switch (e->attr) {
307 case CEXPR_USER:
308 val1 = scontext->user;
309 val2 = tcontext->user;
310 break;
311 case CEXPR_TYPE:
312 val1 = scontext->type;
313 val2 = tcontext->type;
314 break;
315 case CEXPR_ROLE:
316 val1 = scontext->role;
317 val2 = tcontext->role;
318 r1 = policydb.role_val_to_struct[val1 - 1];
319 r2 = policydb.role_val_to_struct[val2 - 1];
320 switch (e->op) {
321 case CEXPR_DOM:
322 s[++sp] = ebitmap_get_bit(&r1->dominates,
323 val2 - 1);
324 continue;
325 case CEXPR_DOMBY:
326 s[++sp] = ebitmap_get_bit(&r2->dominates,
327 val1 - 1);
328 continue;
329 case CEXPR_INCOMP:
330 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
331 val2 - 1) &&
332 !ebitmap_get_bit(&r2->dominates,
333 val1 - 1));
334 continue;
335 default:
336 break;
337 }
338 break;
339 case CEXPR_L1L2:
340 l1 = &(scontext->range.level[0]);
341 l2 = &(tcontext->range.level[0]);
342 goto mls_ops;
343 case CEXPR_L1H2:
344 l1 = &(scontext->range.level[0]);
345 l2 = &(tcontext->range.level[1]);
346 goto mls_ops;
347 case CEXPR_H1L2:
348 l1 = &(scontext->range.level[1]);
349 l2 = &(tcontext->range.level[0]);
350 goto mls_ops;
351 case CEXPR_H1H2:
352 l1 = &(scontext->range.level[1]);
353 l2 = &(tcontext->range.level[1]);
354 goto mls_ops;
355 case CEXPR_L1H1:
356 l1 = &(scontext->range.level[0]);
357 l2 = &(scontext->range.level[1]);
358 goto mls_ops;
359 case CEXPR_L2H2:
360 l1 = &(tcontext->range.level[0]);
361 l2 = &(tcontext->range.level[1]);
362 goto mls_ops;
363 mls_ops:
364 switch (e->op) {
365 case CEXPR_EQ:
366 s[++sp] = mls_level_eq(l1, l2);
367 continue;
368 case CEXPR_NEQ:
369 s[++sp] = !mls_level_eq(l1, l2);
370 continue;
371 case CEXPR_DOM:
372 s[++sp] = mls_level_dom(l1, l2);
373 continue;
374 case CEXPR_DOMBY:
375 s[++sp] = mls_level_dom(l2, l1);
376 continue;
377 case CEXPR_INCOMP:
378 s[++sp] = mls_level_incomp(l2, l1);
379 continue;
380 default:
381 BUG();
382 return 0;
383 }
384 break;
385 default:
386 BUG();
387 return 0;
388 }
389
390 switch (e->op) {
391 case CEXPR_EQ:
392 s[++sp] = (val1 == val2);
393 break;
394 case CEXPR_NEQ:
395 s[++sp] = (val1 != val2);
396 break;
397 default:
398 BUG();
399 return 0;
400 }
401 break;
402 case CEXPR_NAMES:
403 if (sp == (CEXPR_MAXDEPTH-1))
404 return 0;
405 c = scontext;
406 if (e->attr & CEXPR_TARGET)
407 c = tcontext;
408 else if (e->attr & CEXPR_XTARGET) {
409 c = xcontext;
410 if (!c) {
411 BUG();
412 return 0;
413 }
414 }
415 if (e->attr & CEXPR_USER)
416 val1 = c->user;
417 else if (e->attr & CEXPR_ROLE)
418 val1 = c->role;
419 else if (e->attr & CEXPR_TYPE)
420 val1 = c->type;
421 else {
422 BUG();
423 return 0;
424 }
425
426 switch (e->op) {
427 case CEXPR_EQ:
428 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
429 break;
430 case CEXPR_NEQ:
431 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
432 break;
433 default:
434 BUG();
435 return 0;
436 }
437 break;
438 default:
439 BUG();
440 return 0;
441 }
442 }
443
444 BUG_ON(sp != 0);
445 return s[0];
446 }
447
448 /*
449 * security_dump_masked_av - dumps masked permissions during
450 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
451 */
452 static int dump_masked_av_helper(void *k, void *d, void *args)
453 {
454 struct perm_datum *pdatum = d;
455 char **permission_names = args;
456
457 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
458
459 permission_names[pdatum->value - 1] = (char *)k;
460
461 return 0;
462 }
463
464 static void security_dump_masked_av(struct context *scontext,
465 struct context *tcontext,
466 u16 tclass,
467 u32 permissions,
468 const char *reason)
469 {
470 struct common_datum *common_dat;
471 struct class_datum *tclass_dat;
472 struct audit_buffer *ab;
473 char *tclass_name;
474 char *scontext_name = NULL;
475 char *tcontext_name = NULL;
476 char *permission_names[32];
477 int index;
478 u32 length;
479 bool need_comma = false;
480
481 if (!permissions)
482 return;
483
484 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
485 tclass_dat = policydb.class_val_to_struct[tclass - 1];
486 common_dat = tclass_dat->comdatum;
487
488 /* init permission_names */
489 if (common_dat &&
490 hashtab_map(common_dat->permissions.table,
491 dump_masked_av_helper, permission_names) < 0)
492 goto out;
493
494 if (hashtab_map(tclass_dat->permissions.table,
495 dump_masked_av_helper, permission_names) < 0)
496 goto out;
497
498 /* get scontext/tcontext in text form */
499 if (context_struct_to_string(scontext,
500 &scontext_name, &length) < 0)
501 goto out;
502
503 if (context_struct_to_string(tcontext,
504 &tcontext_name, &length) < 0)
505 goto out;
506
507 /* audit a message */
508 ab = audit_log_start(current->audit_context,
509 GFP_ATOMIC, AUDIT_SELINUX_ERR);
510 if (!ab)
511 goto out;
512
513 audit_log_format(ab, "op=security_compute_av reason=%s "
514 "scontext=%s tcontext=%s tclass=%s perms=",
515 reason, scontext_name, tcontext_name, tclass_name);
516
517 for (index = 0; index < 32; index++) {
518 u32 mask = (1 << index);
519
520 if ((mask & permissions) == 0)
521 continue;
522
523 audit_log_format(ab, "%s%s",
524 need_comma ? "," : "",
525 permission_names[index]
526 ? permission_names[index] : "????");
527 need_comma = true;
528 }
529 audit_log_end(ab);
530 out:
531 /* release scontext/tcontext */
532 kfree(tcontext_name);
533 kfree(scontext_name);
534
535 return;
536 }
537
538 /*
539 * security_boundary_permission - drops violated permissions
540 * on boundary constraint.
541 */
542 static void type_attribute_bounds_av(struct context *scontext,
543 struct context *tcontext,
544 u16 tclass,
545 struct av_decision *avd)
546 {
547 struct context lo_scontext;
548 struct context lo_tcontext, *tcontextp = tcontext;
549 struct av_decision lo_avd;
550 struct type_datum *source;
551 struct type_datum *target;
552 u32 masked = 0;
553
554 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
555 scontext->type - 1);
556 BUG_ON(!source);
557
558 if (!source->bounds)
559 return;
560
561 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
562 tcontext->type - 1);
563 BUG_ON(!target);
564
565 memset(&lo_avd, 0, sizeof(lo_avd));
566
567 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
568 lo_scontext.type = source->bounds;
569
570 if (target->bounds) {
571 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
572 lo_tcontext.type = target->bounds;
573 tcontextp = &lo_tcontext;
574 }
575
576 context_struct_compute_av(&lo_scontext,
577 tcontextp,
578 tclass,
579 &lo_avd,
580 NULL);
581
582 masked = ~lo_avd.allowed & avd->allowed;
583
584 if (likely(!masked))
585 return; /* no masked permission */
586
587 /* mask violated permissions */
588 avd->allowed &= ~masked;
589
590 /* audit masked permissions */
591 security_dump_masked_av(scontext, tcontext,
592 tclass, masked, "bounds");
593 }
594
595 /*
596 * flag which drivers have permissions
597 * only looking for ioctl based extended permssions
598 */
599 void services_compute_xperms_drivers(
600 struct extended_perms *xperms,
601 struct avtab_node *node)
602 {
603 unsigned int i;
604
605 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
606 /* if one or more driver has all permissions allowed */
607 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
608 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
609 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
610 /* if allowing permissions within a driver */
611 security_xperm_set(xperms->drivers.p,
612 node->datum.u.xperms->driver);
613 }
614
615 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
616 if (node->key.specified & AVTAB_XPERMS_ALLOWED)
617 xperms->len = 1;
618 }
619
620 /*
621 * Compute access vectors and extended permissions based on a context
622 * structure pair for the permissions in a particular class.
623 */
624 static void context_struct_compute_av(struct context *scontext,
625 struct context *tcontext,
626 u16 tclass,
627 struct av_decision *avd,
628 struct extended_perms *xperms)
629 {
630 struct constraint_node *constraint;
631 struct role_allow *ra;
632 struct avtab_key avkey;
633 struct avtab_node *node;
634 struct class_datum *tclass_datum;
635 struct ebitmap *sattr, *tattr;
636 struct ebitmap_node *snode, *tnode;
637 unsigned int i, j;
638
639 avd->allowed = 0;
640 avd->auditallow = 0;
641 avd->auditdeny = 0xffffffff;
642 if (xperms) {
643 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
644 xperms->len = 0;
645 }
646
647 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
648 if (printk_ratelimit())
649 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
650 return;
651 }
652
653 tclass_datum = policydb.class_val_to_struct[tclass - 1];
654
655 /*
656 * If a specific type enforcement rule was defined for
657 * this permission check, then use it.
658 */
659 avkey.target_class = tclass;
660 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
661 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
662 BUG_ON(!sattr);
663 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
664 BUG_ON(!tattr);
665 ebitmap_for_each_positive_bit(sattr, snode, i) {
666 ebitmap_for_each_positive_bit(tattr, tnode, j) {
667 avkey.source_type = i + 1;
668 avkey.target_type = j + 1;
669 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
670 node;
671 node = avtab_search_node_next(node, avkey.specified)) {
672 if (node->key.specified == AVTAB_ALLOWED)
673 avd->allowed |= node->datum.u.data;
674 else if (node->key.specified == AVTAB_AUDITALLOW)
675 avd->auditallow |= node->datum.u.data;
676 else if (node->key.specified == AVTAB_AUDITDENY)
677 avd->auditdeny &= node->datum.u.data;
678 else if (xperms && (node->key.specified & AVTAB_XPERMS))
679 services_compute_xperms_drivers(xperms, node);
680 }
681
682 /* Check conditional av table for additional permissions */
683 cond_compute_av(&policydb.te_cond_avtab, &avkey,
684 avd, xperms);
685
686 }
687 }
688
689 /*
690 * Remove any permissions prohibited by a constraint (this includes
691 * the MLS policy).
692 */
693 constraint = tclass_datum->constraints;
694 while (constraint) {
695 if ((constraint->permissions & (avd->allowed)) &&
696 !constraint_expr_eval(scontext, tcontext, NULL,
697 constraint->expr)) {
698 avd->allowed &= ~(constraint->permissions);
699 }
700 constraint = constraint->next;
701 }
702
703 /*
704 * If checking process transition permission and the
705 * role is changing, then check the (current_role, new_role)
706 * pair.
707 */
708 if (tclass == policydb.process_class &&
709 (avd->allowed & policydb.process_trans_perms) &&
710 scontext->role != tcontext->role) {
711 for (ra = policydb.role_allow; ra; ra = ra->next) {
712 if (scontext->role == ra->role &&
713 tcontext->role == ra->new_role)
714 break;
715 }
716 if (!ra)
717 avd->allowed &= ~policydb.process_trans_perms;
718 }
719
720 /*
721 * If the given source and target types have boundary
722 * constraint, lazy checks have to mask any violated
723 * permission and notice it to userspace via audit.
724 */
725 type_attribute_bounds_av(scontext, tcontext,
726 tclass, avd);
727 }
728
729 static int security_validtrans_handle_fail(struct context *ocontext,
730 struct context *ncontext,
731 struct context *tcontext,
732 u16 tclass)
733 {
734 char *o = NULL, *n = NULL, *t = NULL;
735 u32 olen, nlen, tlen;
736
737 if (context_struct_to_string(ocontext, &o, &olen))
738 goto out;
739 if (context_struct_to_string(ncontext, &n, &nlen))
740 goto out;
741 if (context_struct_to_string(tcontext, &t, &tlen))
742 goto out;
743 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
744 "op=security_validate_transition seresult=denied"
745 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
746 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
747 out:
748 kfree(o);
749 kfree(n);
750 kfree(t);
751
752 if (!selinux_enforcing)
753 return 0;
754 return -EPERM;
755 }
756
757 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
758 u16 orig_tclass, bool user)
759 {
760 struct context *ocontext;
761 struct context *ncontext;
762 struct context *tcontext;
763 struct class_datum *tclass_datum;
764 struct constraint_node *constraint;
765 u16 tclass;
766 int rc = 0;
767
768 if (!ss_initialized)
769 return 0;
770
771 read_lock(&policy_rwlock);
772
773 if (!user)
774 tclass = unmap_class(orig_tclass);
775 else
776 tclass = orig_tclass;
777
778 if (!tclass || tclass > policydb.p_classes.nprim) {
779 rc = -EINVAL;
780 goto out;
781 }
782 tclass_datum = policydb.class_val_to_struct[tclass - 1];
783
784 ocontext = sidtab_search(&sidtab, oldsid);
785 if (!ocontext) {
786 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
787 __func__, oldsid);
788 rc = -EINVAL;
789 goto out;
790 }
791
792 ncontext = sidtab_search(&sidtab, newsid);
793 if (!ncontext) {
794 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
795 __func__, newsid);
796 rc = -EINVAL;
797 goto out;
798 }
799
800 tcontext = sidtab_search(&sidtab, tasksid);
801 if (!tcontext) {
802 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
803 __func__, tasksid);
804 rc = -EINVAL;
805 goto out;
806 }
807
808 constraint = tclass_datum->validatetrans;
809 while (constraint) {
810 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
811 constraint->expr)) {
812 if (user)
813 rc = -EPERM;
814 else
815 rc = security_validtrans_handle_fail(ocontext,
816 ncontext,
817 tcontext,
818 tclass);
819 goto out;
820 }
821 constraint = constraint->next;
822 }
823
824 out:
825 read_unlock(&policy_rwlock);
826 return rc;
827 }
828
829 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
830 u16 tclass)
831 {
832 return security_compute_validatetrans(oldsid, newsid, tasksid,
833 tclass, true);
834 }
835
836 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
837 u16 orig_tclass)
838 {
839 return security_compute_validatetrans(oldsid, newsid, tasksid,
840 orig_tclass, false);
841 }
842
843 /*
844 * security_bounded_transition - check whether the given
845 * transition is directed to bounded, or not.
846 * It returns 0, if @newsid is bounded by @oldsid.
847 * Otherwise, it returns error code.
848 *
849 * @oldsid : current security identifier
850 * @newsid : destinated security identifier
851 */
852 int security_bounded_transition(u32 old_sid, u32 new_sid)
853 {
854 struct context *old_context, *new_context;
855 struct type_datum *type;
856 int index;
857 int rc;
858
859 read_lock(&policy_rwlock);
860
861 rc = -EINVAL;
862 old_context = sidtab_search(&sidtab, old_sid);
863 if (!old_context) {
864 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
865 __func__, old_sid);
866 goto out;
867 }
868
869 rc = -EINVAL;
870 new_context = sidtab_search(&sidtab, new_sid);
871 if (!new_context) {
872 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
873 __func__, new_sid);
874 goto out;
875 }
876
877 rc = 0;
878 /* type/domain unchanged */
879 if (old_context->type == new_context->type)
880 goto out;
881
882 index = new_context->type;
883 while (true) {
884 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
885 index - 1);
886 BUG_ON(!type);
887
888 /* not bounded anymore */
889 rc = -EPERM;
890 if (!type->bounds)
891 break;
892
893 /* @newsid is bounded by @oldsid */
894 rc = 0;
895 if (type->bounds == old_context->type)
896 break;
897
898 index = type->bounds;
899 }
900
901 if (rc) {
902 char *old_name = NULL;
903 char *new_name = NULL;
904 u32 length;
905
906 if (!context_struct_to_string(old_context,
907 &old_name, &length) &&
908 !context_struct_to_string(new_context,
909 &new_name, &length)) {
910 audit_log(current->audit_context,
911 GFP_ATOMIC, AUDIT_SELINUX_ERR,
912 "op=security_bounded_transition "
913 "seresult=denied "
914 "oldcontext=%s newcontext=%s",
915 old_name, new_name);
916 }
917 kfree(new_name);
918 kfree(old_name);
919 }
920 out:
921 read_unlock(&policy_rwlock);
922
923 return rc;
924 }
925
926 static void avd_init(struct av_decision *avd)
927 {
928 avd->allowed = 0;
929 avd->auditallow = 0;
930 avd->auditdeny = 0xffffffff;
931 avd->seqno = latest_granting;
932 avd->flags = 0;
933 }
934
935 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
936 struct avtab_node *node)
937 {
938 unsigned int i;
939
940 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
941 if (xpermd->driver != node->datum.u.xperms->driver)
942 return;
943 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
944 if (!security_xperm_test(node->datum.u.xperms->perms.p,
945 xpermd->driver))
946 return;
947 } else {
948 BUG();
949 }
950
951 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
952 xpermd->used |= XPERMS_ALLOWED;
953 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
954 memset(xpermd->allowed->p, 0xff,
955 sizeof(xpermd->allowed->p));
956 }
957 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
958 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
959 xpermd->allowed->p[i] |=
960 node->datum.u.xperms->perms.p[i];
961 }
962 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
963 xpermd->used |= XPERMS_AUDITALLOW;
964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
965 memset(xpermd->auditallow->p, 0xff,
966 sizeof(xpermd->auditallow->p));
967 }
968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
969 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
970 xpermd->auditallow->p[i] |=
971 node->datum.u.xperms->perms.p[i];
972 }
973 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
974 xpermd->used |= XPERMS_DONTAUDIT;
975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
976 memset(xpermd->dontaudit->p, 0xff,
977 sizeof(xpermd->dontaudit->p));
978 }
979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
980 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
981 xpermd->dontaudit->p[i] |=
982 node->datum.u.xperms->perms.p[i];
983 }
984 } else {
985 BUG();
986 }
987 }
988
989 void security_compute_xperms_decision(u32 ssid,
990 u32 tsid,
991 u16 orig_tclass,
992 u8 driver,
993 struct extended_perms_decision *xpermd)
994 {
995 u16 tclass;
996 struct context *scontext, *tcontext;
997 struct avtab_key avkey;
998 struct avtab_node *node;
999 struct ebitmap *sattr, *tattr;
1000 struct ebitmap_node *snode, *tnode;
1001 unsigned int i, j;
1002
1003 xpermd->driver = driver;
1004 xpermd->used = 0;
1005 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1006 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1007 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1008
1009 read_lock(&policy_rwlock);
1010 if (!ss_initialized)
1011 goto allow;
1012
1013 scontext = sidtab_search(&sidtab, ssid);
1014 if (!scontext) {
1015 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1016 __func__, ssid);
1017 goto out;
1018 }
1019
1020 tcontext = sidtab_search(&sidtab, tsid);
1021 if (!tcontext) {
1022 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1023 __func__, tsid);
1024 goto out;
1025 }
1026
1027 tclass = unmap_class(orig_tclass);
1028 if (unlikely(orig_tclass && !tclass)) {
1029 if (policydb.allow_unknown)
1030 goto allow;
1031 goto out;
1032 }
1033
1034
1035 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1036 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1037 goto out;
1038 }
1039
1040 avkey.target_class = tclass;
1041 avkey.specified = AVTAB_XPERMS;
1042 sattr = flex_array_get(policydb.type_attr_map_array,
1043 scontext->type - 1);
1044 BUG_ON(!sattr);
1045 tattr = flex_array_get(policydb.type_attr_map_array,
1046 tcontext->type - 1);
1047 BUG_ON(!tattr);
1048 ebitmap_for_each_positive_bit(sattr, snode, i) {
1049 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1050 avkey.source_type = i + 1;
1051 avkey.target_type = j + 1;
1052 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1053 node;
1054 node = avtab_search_node_next(node, avkey.specified))
1055 services_compute_xperms_decision(xpermd, node);
1056
1057 cond_compute_xperms(&policydb.te_cond_avtab,
1058 &avkey, xpermd);
1059 }
1060 }
1061 out:
1062 read_unlock(&policy_rwlock);
1063 return;
1064 allow:
1065 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1066 goto out;
1067 }
1068
1069 /**
1070 * security_compute_av - Compute access vector decisions.
1071 * @ssid: source security identifier
1072 * @tsid: target security identifier
1073 * @tclass: target security class
1074 * @avd: access vector decisions
1075 * @xperms: extended permissions
1076 *
1077 * Compute a set of access vector decisions based on the
1078 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1079 */
1080 void security_compute_av(u32 ssid,
1081 u32 tsid,
1082 u16 orig_tclass,
1083 struct av_decision *avd,
1084 struct extended_perms *xperms)
1085 {
1086 u16 tclass;
1087 struct context *scontext = NULL, *tcontext = NULL;
1088
1089 read_lock(&policy_rwlock);
1090 avd_init(avd);
1091 xperms->len = 0;
1092 if (!ss_initialized)
1093 goto allow;
1094
1095 scontext = sidtab_search(&sidtab, ssid);
1096 if (!scontext) {
1097 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1098 __func__, ssid);
1099 goto out;
1100 }
1101
1102 /* permissive domain? */
1103 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1104 avd->flags |= AVD_FLAGS_PERMISSIVE;
1105
1106 tcontext = sidtab_search(&sidtab, tsid);
1107 if (!tcontext) {
1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1109 __func__, tsid);
1110 goto out;
1111 }
1112
1113 tclass = unmap_class(orig_tclass);
1114 if (unlikely(orig_tclass && !tclass)) {
1115 if (policydb.allow_unknown)
1116 goto allow;
1117 goto out;
1118 }
1119 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1120 map_decision(orig_tclass, avd, policydb.allow_unknown);
1121 out:
1122 read_unlock(&policy_rwlock);
1123 return;
1124 allow:
1125 avd->allowed = 0xffffffff;
1126 goto out;
1127 }
1128
1129 void security_compute_av_user(u32 ssid,
1130 u32 tsid,
1131 u16 tclass,
1132 struct av_decision *avd)
1133 {
1134 struct context *scontext = NULL, *tcontext = NULL;
1135
1136 read_lock(&policy_rwlock);
1137 avd_init(avd);
1138 if (!ss_initialized)
1139 goto allow;
1140
1141 scontext = sidtab_search(&sidtab, ssid);
1142 if (!scontext) {
1143 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1144 __func__, ssid);
1145 goto out;
1146 }
1147
1148 /* permissive domain? */
1149 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1150 avd->flags |= AVD_FLAGS_PERMISSIVE;
1151
1152 tcontext = sidtab_search(&sidtab, tsid);
1153 if (!tcontext) {
1154 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1155 __func__, tsid);
1156 goto out;
1157 }
1158
1159 if (unlikely(!tclass)) {
1160 if (policydb.allow_unknown)
1161 goto allow;
1162 goto out;
1163 }
1164
1165 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1166 out:
1167 read_unlock(&policy_rwlock);
1168 return;
1169 allow:
1170 avd->allowed = 0xffffffff;
1171 goto out;
1172 }
1173
1174 /*
1175 * Write the security context string representation of
1176 * the context structure `context' into a dynamically
1177 * allocated string of the correct size. Set `*scontext'
1178 * to point to this string and set `*scontext_len' to
1179 * the length of the string.
1180 */
1181 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1182 {
1183 char *scontextp;
1184
1185 if (scontext)
1186 *scontext = NULL;
1187 *scontext_len = 0;
1188
1189 if (context->len) {
1190 *scontext_len = context->len;
1191 if (scontext) {
1192 *scontext = kstrdup(context->str, GFP_ATOMIC);
1193 if (!(*scontext))
1194 return -ENOMEM;
1195 }
1196 return 0;
1197 }
1198
1199 /* Compute the size of the context. */
1200 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1201 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1202 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1203 *scontext_len += mls_compute_context_len(context);
1204
1205 if (!scontext)
1206 return 0;
1207
1208 /* Allocate space for the context; caller must free this space. */
1209 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1210 if (!scontextp)
1211 return -ENOMEM;
1212 *scontext = scontextp;
1213
1214 /*
1215 * Copy the user name, role name and type name into the context.
1216 */
1217 scontextp += sprintf(scontextp, "%s:%s:%s",
1218 sym_name(&policydb, SYM_USERS, context->user - 1),
1219 sym_name(&policydb, SYM_ROLES, context->role - 1),
1220 sym_name(&policydb, SYM_TYPES, context->type - 1));
1221
1222 mls_sid_to_context(context, &scontextp);
1223
1224 *scontextp = 0;
1225
1226 return 0;
1227 }
1228
1229 #include "initial_sid_to_string.h"
1230
1231 const char *security_get_initial_sid_context(u32 sid)
1232 {
1233 if (unlikely(sid > SECINITSID_NUM))
1234 return NULL;
1235 return initial_sid_to_string[sid];
1236 }
1237
1238 static int security_sid_to_context_core(u32 sid, char **scontext,
1239 u32 *scontext_len, int force)
1240 {
1241 struct context *context;
1242 int rc = 0;
1243
1244 if (scontext)
1245 *scontext = NULL;
1246 *scontext_len = 0;
1247
1248 if (!ss_initialized) {
1249 if (sid <= SECINITSID_NUM) {
1250 char *scontextp;
1251
1252 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1253 if (!scontext)
1254 goto out;
1255 scontextp = kmemdup(initial_sid_to_string[sid],
1256 *scontext_len, GFP_ATOMIC);
1257 if (!scontextp) {
1258 rc = -ENOMEM;
1259 goto out;
1260 }
1261 *scontext = scontextp;
1262 goto out;
1263 }
1264 printk(KERN_ERR "SELinux: %s: called before initial "
1265 "load_policy on unknown SID %d\n", __func__, sid);
1266 rc = -EINVAL;
1267 goto out;
1268 }
1269 read_lock(&policy_rwlock);
1270 if (force)
1271 context = sidtab_search_force(&sidtab, sid);
1272 else
1273 context = sidtab_search(&sidtab, sid);
1274 if (!context) {
1275 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1276 __func__, sid);
1277 rc = -EINVAL;
1278 goto out_unlock;
1279 }
1280 rc = context_struct_to_string(context, scontext, scontext_len);
1281 out_unlock:
1282 read_unlock(&policy_rwlock);
1283 out:
1284 return rc;
1285
1286 }
1287
1288 /**
1289 * security_sid_to_context - Obtain a context for a given SID.
1290 * @sid: security identifier, SID
1291 * @scontext: security context
1292 * @scontext_len: length in bytes
1293 *
1294 * Write the string representation of the context associated with @sid
1295 * into a dynamically allocated string of the correct size. Set @scontext
1296 * to point to this string and set @scontext_len to the length of the string.
1297 */
1298 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1299 {
1300 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1301 }
1302
1303 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1304 {
1305 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1306 }
1307
1308 /*
1309 * Caveat: Mutates scontext.
1310 */
1311 static int string_to_context_struct(struct policydb *pol,
1312 struct sidtab *sidtabp,
1313 char *scontext,
1314 u32 scontext_len,
1315 struct context *ctx,
1316 u32 def_sid)
1317 {
1318 struct role_datum *role;
1319 struct type_datum *typdatum;
1320 struct user_datum *usrdatum;
1321 char *scontextp, *p, oldc;
1322 int rc = 0;
1323
1324 context_init(ctx);
1325
1326 /* Parse the security context. */
1327
1328 rc = -EINVAL;
1329 scontextp = (char *) scontext;
1330
1331 /* Extract the user. */
1332 p = scontextp;
1333 while (*p && *p != ':')
1334 p++;
1335
1336 if (*p == 0)
1337 goto out;
1338
1339 *p++ = 0;
1340
1341 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1342 if (!usrdatum)
1343 goto out;
1344
1345 ctx->user = usrdatum->value;
1346
1347 /* Extract role. */
1348 scontextp = p;
1349 while (*p && *p != ':')
1350 p++;
1351
1352 if (*p == 0)
1353 goto out;
1354
1355 *p++ = 0;
1356
1357 role = hashtab_search(pol->p_roles.table, scontextp);
1358 if (!role)
1359 goto out;
1360 ctx->role = role->value;
1361
1362 /* Extract type. */
1363 scontextp = p;
1364 while (*p && *p != ':')
1365 p++;
1366 oldc = *p;
1367 *p++ = 0;
1368
1369 typdatum = hashtab_search(pol->p_types.table, scontextp);
1370 if (!typdatum || typdatum->attribute)
1371 goto out;
1372
1373 ctx->type = typdatum->value;
1374
1375 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1376 if (rc)
1377 goto out;
1378
1379 rc = -EINVAL;
1380 if ((p - scontext) < scontext_len)
1381 goto out;
1382
1383 /* Check the validity of the new context. */
1384 if (!policydb_context_isvalid(pol, ctx))
1385 goto out;
1386 rc = 0;
1387 out:
1388 if (rc)
1389 context_destroy(ctx);
1390 return rc;
1391 }
1392
1393 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1394 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1395 int force)
1396 {
1397 char *scontext2, *str = NULL;
1398 struct context context;
1399 int rc = 0;
1400
1401 /* An empty security context is never valid. */
1402 if (!scontext_len)
1403 return -EINVAL;
1404
1405 if (!ss_initialized) {
1406 int i;
1407
1408 for (i = 1; i < SECINITSID_NUM; i++) {
1409 if (!strcmp(initial_sid_to_string[i], scontext)) {
1410 *sid = i;
1411 return 0;
1412 }
1413 }
1414 *sid = SECINITSID_KERNEL;
1415 return 0;
1416 }
1417 *sid = SECSID_NULL;
1418
1419 /* Copy the string so that we can modify the copy as we parse it. */
1420 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1421 if (!scontext2)
1422 return -ENOMEM;
1423 memcpy(scontext2, scontext, scontext_len);
1424 scontext2[scontext_len] = 0;
1425
1426 if (force) {
1427 /* Save another copy for storing in uninterpreted form */
1428 rc = -ENOMEM;
1429 str = kstrdup(scontext2, gfp_flags);
1430 if (!str)
1431 goto out;
1432 }
1433
1434 read_lock(&policy_rwlock);
1435 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1436 scontext_len, &context, def_sid);
1437 if (rc == -EINVAL && force) {
1438 context.str = str;
1439 context.len = scontext_len;
1440 str = NULL;
1441 } else if (rc)
1442 goto out_unlock;
1443 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1444 context_destroy(&context);
1445 out_unlock:
1446 read_unlock(&policy_rwlock);
1447 out:
1448 kfree(scontext2);
1449 kfree(str);
1450 return rc;
1451 }
1452
1453 /**
1454 * security_context_to_sid - Obtain a SID for a given security context.
1455 * @scontext: security context
1456 * @scontext_len: length in bytes
1457 * @sid: security identifier, SID
1458 * @gfp: context for the allocation
1459 *
1460 * Obtains a SID associated with the security context that
1461 * has the string representation specified by @scontext.
1462 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1463 * memory is available, or 0 on success.
1464 */
1465 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1466 gfp_t gfp)
1467 {
1468 return security_context_to_sid_core(scontext, scontext_len,
1469 sid, SECSID_NULL, gfp, 0);
1470 }
1471
1472 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1473 {
1474 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1475 }
1476
1477 /**
1478 * security_context_to_sid_default - Obtain a SID for a given security context,
1479 * falling back to specified default if needed.
1480 *
1481 * @scontext: security context
1482 * @scontext_len: length in bytes
1483 * @sid: security identifier, SID
1484 * @def_sid: default SID to assign on error
1485 *
1486 * Obtains a SID associated with the security context that
1487 * has the string representation specified by @scontext.
1488 * The default SID is passed to the MLS layer to be used to allow
1489 * kernel labeling of the MLS field if the MLS field is not present
1490 * (for upgrading to MLS without full relabel).
1491 * Implicitly forces adding of the context even if it cannot be mapped yet.
1492 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1493 * memory is available, or 0 on success.
1494 */
1495 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1496 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1497 {
1498 return security_context_to_sid_core(scontext, scontext_len,
1499 sid, def_sid, gfp_flags, 1);
1500 }
1501
1502 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1503 u32 *sid)
1504 {
1505 return security_context_to_sid_core(scontext, scontext_len,
1506 sid, SECSID_NULL, GFP_KERNEL, 1);
1507 }
1508
1509 static int compute_sid_handle_invalid_context(
1510 struct context *scontext,
1511 struct context *tcontext,
1512 u16 tclass,
1513 struct context *newcontext)
1514 {
1515 char *s = NULL, *t = NULL, *n = NULL;
1516 u32 slen, tlen, nlen;
1517
1518 if (context_struct_to_string(scontext, &s, &slen))
1519 goto out;
1520 if (context_struct_to_string(tcontext, &t, &tlen))
1521 goto out;
1522 if (context_struct_to_string(newcontext, &n, &nlen))
1523 goto out;
1524 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1525 "op=security_compute_sid invalid_context=%s"
1526 " scontext=%s"
1527 " tcontext=%s"
1528 " tclass=%s",
1529 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1530 out:
1531 kfree(s);
1532 kfree(t);
1533 kfree(n);
1534 if (!selinux_enforcing)
1535 return 0;
1536 return -EACCES;
1537 }
1538
1539 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1540 u32 stype, u32 ttype, u16 tclass,
1541 const char *objname)
1542 {
1543 struct filename_trans ft;
1544 struct filename_trans_datum *otype;
1545
1546 /*
1547 * Most filename trans rules are going to live in specific directories
1548 * like /dev or /var/run. This bitmap will quickly skip rule searches
1549 * if the ttype does not contain any rules.
1550 */
1551 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1552 return;
1553
1554 ft.stype = stype;
1555 ft.ttype = ttype;
1556 ft.tclass = tclass;
1557 ft.name = objname;
1558
1559 otype = hashtab_search(p->filename_trans, &ft);
1560 if (otype)
1561 newcontext->type = otype->otype;
1562 }
1563
1564 static int security_compute_sid(u32 ssid,
1565 u32 tsid,
1566 u16 orig_tclass,
1567 u32 specified,
1568 const char *objname,
1569 u32 *out_sid,
1570 bool kern)
1571 {
1572 struct class_datum *cladatum = NULL;
1573 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1574 struct role_trans *roletr = NULL;
1575 struct avtab_key avkey;
1576 struct avtab_datum *avdatum;
1577 struct avtab_node *node;
1578 u16 tclass;
1579 int rc = 0;
1580 bool sock;
1581
1582 if (!ss_initialized) {
1583 switch (orig_tclass) {
1584 case SECCLASS_PROCESS: /* kernel value */
1585 *out_sid = ssid;
1586 break;
1587 default:
1588 *out_sid = tsid;
1589 break;
1590 }
1591 goto out;
1592 }
1593
1594 context_init(&newcontext);
1595
1596 read_lock(&policy_rwlock);
1597
1598 if (kern) {
1599 tclass = unmap_class(orig_tclass);
1600 sock = security_is_socket_class(orig_tclass);
1601 } else {
1602 tclass = orig_tclass;
1603 sock = security_is_socket_class(map_class(tclass));
1604 }
1605
1606 scontext = sidtab_search(&sidtab, ssid);
1607 if (!scontext) {
1608 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1609 __func__, ssid);
1610 rc = -EINVAL;
1611 goto out_unlock;
1612 }
1613 tcontext = sidtab_search(&sidtab, tsid);
1614 if (!tcontext) {
1615 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1616 __func__, tsid);
1617 rc = -EINVAL;
1618 goto out_unlock;
1619 }
1620
1621 if (tclass && tclass <= policydb.p_classes.nprim)
1622 cladatum = policydb.class_val_to_struct[tclass - 1];
1623
1624 /* Set the user identity. */
1625 switch (specified) {
1626 case AVTAB_TRANSITION:
1627 case AVTAB_CHANGE:
1628 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1629 newcontext.user = tcontext->user;
1630 } else {
1631 /* notice this gets both DEFAULT_SOURCE and unset */
1632 /* Use the process user identity. */
1633 newcontext.user = scontext->user;
1634 }
1635 break;
1636 case AVTAB_MEMBER:
1637 /* Use the related object owner. */
1638 newcontext.user = tcontext->user;
1639 break;
1640 }
1641
1642 /* Set the role to default values. */
1643 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1644 newcontext.role = scontext->role;
1645 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1646 newcontext.role = tcontext->role;
1647 } else {
1648 if ((tclass == policydb.process_class) || (sock == true))
1649 newcontext.role = scontext->role;
1650 else
1651 newcontext.role = OBJECT_R_VAL;
1652 }
1653
1654 /* Set the type to default values. */
1655 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1656 newcontext.type = scontext->type;
1657 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1658 newcontext.type = tcontext->type;
1659 } else {
1660 if ((tclass == policydb.process_class) || (sock == true)) {
1661 /* Use the type of process. */
1662 newcontext.type = scontext->type;
1663 } else {
1664 /* Use the type of the related object. */
1665 newcontext.type = tcontext->type;
1666 }
1667 }
1668
1669 /* Look for a type transition/member/change rule. */
1670 avkey.source_type = scontext->type;
1671 avkey.target_type = tcontext->type;
1672 avkey.target_class = tclass;
1673 avkey.specified = specified;
1674 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1675
1676 /* If no permanent rule, also check for enabled conditional rules */
1677 if (!avdatum) {
1678 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1679 for (; node; node = avtab_search_node_next(node, specified)) {
1680 if (node->key.specified & AVTAB_ENABLED) {
1681 avdatum = &node->datum;
1682 break;
1683 }
1684 }
1685 }
1686
1687 if (avdatum) {
1688 /* Use the type from the type transition/member/change rule. */
1689 newcontext.type = avdatum->u.data;
1690 }
1691
1692 /* if we have a objname this is a file trans check so check those rules */
1693 if (objname)
1694 filename_compute_type(&policydb, &newcontext, scontext->type,
1695 tcontext->type, tclass, objname);
1696
1697 /* Check for class-specific changes. */
1698 if (specified & AVTAB_TRANSITION) {
1699 /* Look for a role transition rule. */
1700 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1701 if ((roletr->role == scontext->role) &&
1702 (roletr->type == tcontext->type) &&
1703 (roletr->tclass == tclass)) {
1704 /* Use the role transition rule. */
1705 newcontext.role = roletr->new_role;
1706 break;
1707 }
1708 }
1709 }
1710
1711 /* Set the MLS attributes.
1712 This is done last because it may allocate memory. */
1713 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1714 &newcontext, sock);
1715 if (rc)
1716 goto out_unlock;
1717
1718 /* Check the validity of the context. */
1719 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1720 rc = compute_sid_handle_invalid_context(scontext,
1721 tcontext,
1722 tclass,
1723 &newcontext);
1724 if (rc)
1725 goto out_unlock;
1726 }
1727 /* Obtain the sid for the context. */
1728 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1729 out_unlock:
1730 read_unlock(&policy_rwlock);
1731 context_destroy(&newcontext);
1732 out:
1733 return rc;
1734 }
1735
1736 /**
1737 * security_transition_sid - Compute the SID for a new subject/object.
1738 * @ssid: source security identifier
1739 * @tsid: target security identifier
1740 * @tclass: target security class
1741 * @out_sid: security identifier for new subject/object
1742 *
1743 * Compute a SID to use for labeling a new subject or object in the
1744 * class @tclass based on a SID pair (@ssid, @tsid).
1745 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1746 * if insufficient memory is available, or %0 if the new SID was
1747 * computed successfully.
1748 */
1749 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1750 const struct qstr *qstr, u32 *out_sid)
1751 {
1752 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1753 qstr ? qstr->name : NULL, out_sid, true);
1754 }
1755
1756 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1757 const char *objname, u32 *out_sid)
1758 {
1759 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1760 objname, out_sid, false);
1761 }
1762
1763 /**
1764 * security_member_sid - Compute the SID for member selection.
1765 * @ssid: source security identifier
1766 * @tsid: target security identifier
1767 * @tclass: target security class
1768 * @out_sid: security identifier for selected member
1769 *
1770 * Compute a SID to use when selecting a member of a polyinstantiated
1771 * object of class @tclass based on a SID pair (@ssid, @tsid).
1772 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1773 * if insufficient memory is available, or %0 if the SID was
1774 * computed successfully.
1775 */
1776 int security_member_sid(u32 ssid,
1777 u32 tsid,
1778 u16 tclass,
1779 u32 *out_sid)
1780 {
1781 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1782 out_sid, false);
1783 }
1784
1785 /**
1786 * security_change_sid - Compute the SID for object relabeling.
1787 * @ssid: source security identifier
1788 * @tsid: target security identifier
1789 * @tclass: target security class
1790 * @out_sid: security identifier for selected member
1791 *
1792 * Compute a SID to use for relabeling an object of class @tclass
1793 * based on a SID pair (@ssid, @tsid).
1794 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1795 * if insufficient memory is available, or %0 if the SID was
1796 * computed successfully.
1797 */
1798 int security_change_sid(u32 ssid,
1799 u32 tsid,
1800 u16 tclass,
1801 u32 *out_sid)
1802 {
1803 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1804 out_sid, false);
1805 }
1806
1807 /* Clone the SID into the new SID table. */
1808 static int clone_sid(u32 sid,
1809 struct context *context,
1810 void *arg)
1811 {
1812 struct sidtab *s = arg;
1813
1814 if (sid > SECINITSID_NUM)
1815 return sidtab_insert(s, sid, context);
1816 else
1817 return 0;
1818 }
1819
1820 static inline int convert_context_handle_invalid_context(struct context *context)
1821 {
1822 char *s;
1823 u32 len;
1824
1825 if (selinux_enforcing)
1826 return -EINVAL;
1827
1828 if (!context_struct_to_string(context, &s, &len)) {
1829 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1830 kfree(s);
1831 }
1832 return 0;
1833 }
1834
1835 struct convert_context_args {
1836 struct policydb *oldp;
1837 struct policydb *newp;
1838 };
1839
1840 /*
1841 * Convert the values in the security context
1842 * structure `c' from the values specified
1843 * in the policy `p->oldp' to the values specified
1844 * in the policy `p->newp'. Verify that the
1845 * context is valid under the new policy.
1846 */
1847 static int convert_context(u32 key,
1848 struct context *c,
1849 void *p)
1850 {
1851 struct convert_context_args *args;
1852 struct context oldc;
1853 struct ocontext *oc;
1854 struct mls_range *range;
1855 struct role_datum *role;
1856 struct type_datum *typdatum;
1857 struct user_datum *usrdatum;
1858 char *s;
1859 u32 len;
1860 int rc = 0;
1861
1862 if (key <= SECINITSID_NUM)
1863 goto out;
1864
1865 args = p;
1866
1867 if (c->str) {
1868 struct context ctx;
1869
1870 rc = -ENOMEM;
1871 s = kstrdup(c->str, GFP_KERNEL);
1872 if (!s)
1873 goto out;
1874
1875 rc = string_to_context_struct(args->newp, NULL, s,
1876 c->len, &ctx, SECSID_NULL);
1877 kfree(s);
1878 if (!rc) {
1879 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1880 c->str);
1881 /* Replace string with mapped representation. */
1882 kfree(c->str);
1883 memcpy(c, &ctx, sizeof(*c));
1884 goto out;
1885 } else if (rc == -EINVAL) {
1886 /* Retain string representation for later mapping. */
1887 rc = 0;
1888 goto out;
1889 } else {
1890 /* Other error condition, e.g. ENOMEM. */
1891 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1892 c->str, -rc);
1893 goto out;
1894 }
1895 }
1896
1897 rc = context_cpy(&oldc, c);
1898 if (rc)
1899 goto out;
1900
1901 /* Convert the user. */
1902 rc = -EINVAL;
1903 usrdatum = hashtab_search(args->newp->p_users.table,
1904 sym_name(args->oldp, SYM_USERS, c->user - 1));
1905 if (!usrdatum)
1906 goto bad;
1907 c->user = usrdatum->value;
1908
1909 /* Convert the role. */
1910 rc = -EINVAL;
1911 role = hashtab_search(args->newp->p_roles.table,
1912 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1913 if (!role)
1914 goto bad;
1915 c->role = role->value;
1916
1917 /* Convert the type. */
1918 rc = -EINVAL;
1919 typdatum = hashtab_search(args->newp->p_types.table,
1920 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1921 if (!typdatum)
1922 goto bad;
1923 c->type = typdatum->value;
1924
1925 /* Convert the MLS fields if dealing with MLS policies */
1926 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1927 rc = mls_convert_context(args->oldp, args->newp, c);
1928 if (rc)
1929 goto bad;
1930 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1931 /*
1932 * Switching between MLS and non-MLS policy:
1933 * free any storage used by the MLS fields in the
1934 * context for all existing entries in the sidtab.
1935 */
1936 mls_context_destroy(c);
1937 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1938 /*
1939 * Switching between non-MLS and MLS policy:
1940 * ensure that the MLS fields of the context for all
1941 * existing entries in the sidtab are filled in with a
1942 * suitable default value, likely taken from one of the
1943 * initial SIDs.
1944 */
1945 oc = args->newp->ocontexts[OCON_ISID];
1946 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1947 oc = oc->next;
1948 rc = -EINVAL;
1949 if (!oc) {
1950 printk(KERN_ERR "SELinux: unable to look up"
1951 " the initial SIDs list\n");
1952 goto bad;
1953 }
1954 range = &oc->context[0].range;
1955 rc = mls_range_set(c, range);
1956 if (rc)
1957 goto bad;
1958 }
1959
1960 /* Check the validity of the new context. */
1961 if (!policydb_context_isvalid(args->newp, c)) {
1962 rc = convert_context_handle_invalid_context(&oldc);
1963 if (rc)
1964 goto bad;
1965 }
1966
1967 context_destroy(&oldc);
1968
1969 rc = 0;
1970 out:
1971 return rc;
1972 bad:
1973 /* Map old representation to string and save it. */
1974 rc = context_struct_to_string(&oldc, &s, &len);
1975 if (rc)
1976 return rc;
1977 context_destroy(&oldc);
1978 context_destroy(c);
1979 c->str = s;
1980 c->len = len;
1981 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1982 c->str);
1983 rc = 0;
1984 goto out;
1985 }
1986
1987 static void security_load_policycaps(void)
1988 {
1989 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1990 POLICYDB_CAPABILITY_NETPEER);
1991 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1992 POLICYDB_CAPABILITY_OPENPERM);
1993 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
1994 POLICYDB_CAPABILITY_EXTSOCKCLASS);
1995 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1996 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1997 selinux_policycap_cgroupseclabel =
1998 ebitmap_get_bit(&policydb.policycaps,
1999 POLICYDB_CAPABILITY_CGROUPSECLABEL);
2000 }
2001
2002 static int security_preserve_bools(struct policydb *p);
2003
2004 /**
2005 * security_load_policy - Load a security policy configuration.
2006 * @data: binary policy data
2007 * @len: length of data in bytes
2008 *
2009 * Load a new set of security policy configuration data,
2010 * validate it and convert the SID table as necessary.
2011 * This function will flush the access vector cache after
2012 * loading the new policy.
2013 */
2014 int security_load_policy(void *data, size_t len)
2015 {
2016 struct policydb *oldpolicydb, *newpolicydb;
2017 struct sidtab oldsidtab, newsidtab;
2018 struct selinux_mapping *oldmap, *map = NULL;
2019 struct convert_context_args args;
2020 u32 seqno;
2021 u16 map_size;
2022 int rc = 0;
2023 struct policy_file file = { data, len }, *fp = &file;
2024
2025 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2026 if (!oldpolicydb) {
2027 rc = -ENOMEM;
2028 goto out;
2029 }
2030 newpolicydb = oldpolicydb + 1;
2031
2032 if (!ss_initialized) {
2033 avtab_cache_init();
2034 rc = policydb_read(&policydb, fp);
2035 if (rc) {
2036 avtab_cache_destroy();
2037 goto out;
2038 }
2039
2040 policydb.len = len;
2041 rc = selinux_set_mapping(&policydb, secclass_map,
2042 &current_mapping,
2043 &current_mapping_size);
2044 if (rc) {
2045 policydb_destroy(&policydb);
2046 avtab_cache_destroy();
2047 goto out;
2048 }
2049
2050 rc = policydb_load_isids(&policydb, &sidtab);
2051 if (rc) {
2052 policydb_destroy(&policydb);
2053 avtab_cache_destroy();
2054 goto out;
2055 }
2056
2057 security_load_policycaps();
2058 ss_initialized = 1;
2059 seqno = ++latest_granting;
2060 selinux_complete_init();
2061 avc_ss_reset(seqno);
2062 selnl_notify_policyload(seqno);
2063 selinux_status_update_policyload(seqno);
2064 selinux_netlbl_cache_invalidate();
2065 selinux_xfrm_notify_policyload();
2066 goto out;
2067 }
2068
2069 #if 0
2070 sidtab_hash_eval(&sidtab, "sids");
2071 #endif
2072
2073 rc = policydb_read(newpolicydb, fp);
2074 if (rc)
2075 goto out;
2076
2077 newpolicydb->len = len;
2078 /* If switching between different policy types, log MLS status */
2079 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2080 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2081 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2082 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2083
2084 rc = policydb_load_isids(newpolicydb, &newsidtab);
2085 if (rc) {
2086 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2087 policydb_destroy(newpolicydb);
2088 goto out;
2089 }
2090
2091 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2092 if (rc)
2093 goto err;
2094
2095 rc = security_preserve_bools(newpolicydb);
2096 if (rc) {
2097 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2098 goto err;
2099 }
2100
2101 /* Clone the SID table. */
2102 sidtab_shutdown(&sidtab);
2103
2104 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2105 if (rc)
2106 goto err;
2107
2108 /*
2109 * Convert the internal representations of contexts
2110 * in the new SID table.
2111 */
2112 args.oldp = &policydb;
2113 args.newp = newpolicydb;
2114 rc = sidtab_map(&newsidtab, convert_context, &args);
2115 if (rc) {
2116 printk(KERN_ERR "SELinux: unable to convert the internal"
2117 " representation of contexts in the new SID"
2118 " table\n");
2119 goto err;
2120 }
2121
2122 /* Save the old policydb and SID table to free later. */
2123 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2124 sidtab_set(&oldsidtab, &sidtab);
2125
2126 /* Install the new policydb and SID table. */
2127 write_lock_irq(&policy_rwlock);
2128 memcpy(&policydb, newpolicydb, sizeof(policydb));
2129 sidtab_set(&sidtab, &newsidtab);
2130 security_load_policycaps();
2131 oldmap = current_mapping;
2132 current_mapping = map;
2133 current_mapping_size = map_size;
2134 seqno = ++latest_granting;
2135 write_unlock_irq(&policy_rwlock);
2136
2137 /* Free the old policydb and SID table. */
2138 policydb_destroy(oldpolicydb);
2139 sidtab_destroy(&oldsidtab);
2140 kfree(oldmap);
2141
2142 avc_ss_reset(seqno);
2143 selnl_notify_policyload(seqno);
2144 selinux_status_update_policyload(seqno);
2145 selinux_netlbl_cache_invalidate();
2146 selinux_xfrm_notify_policyload();
2147
2148 rc = 0;
2149 goto out;
2150
2151 err:
2152 kfree(map);
2153 sidtab_destroy(&newsidtab);
2154 policydb_destroy(newpolicydb);
2155
2156 out:
2157 kfree(oldpolicydb);
2158 return rc;
2159 }
2160
2161 size_t security_policydb_len(void)
2162 {
2163 size_t len;
2164
2165 read_lock(&policy_rwlock);
2166 len = policydb.len;
2167 read_unlock(&policy_rwlock);
2168
2169 return len;
2170 }
2171
2172 /**
2173 * security_port_sid - Obtain the SID for a port.
2174 * @protocol: protocol number
2175 * @port: port number
2176 * @out_sid: security identifier
2177 */
2178 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2179 {
2180 struct ocontext *c;
2181 int rc = 0;
2182
2183 read_lock(&policy_rwlock);
2184
2185 c = policydb.ocontexts[OCON_PORT];
2186 while (c) {
2187 if (c->u.port.protocol == protocol &&
2188 c->u.port.low_port <= port &&
2189 c->u.port.high_port >= port)
2190 break;
2191 c = c->next;
2192 }
2193
2194 if (c) {
2195 if (!c->sid[0]) {
2196 rc = sidtab_context_to_sid(&sidtab,
2197 &c->context[0],
2198 &c->sid[0]);
2199 if (rc)
2200 goto out;
2201 }
2202 *out_sid = c->sid[0];
2203 } else {
2204 *out_sid = SECINITSID_PORT;
2205 }
2206
2207 out:
2208 read_unlock(&policy_rwlock);
2209 return rc;
2210 }
2211
2212 /**
2213 * security_netif_sid - Obtain the SID for a network interface.
2214 * @name: interface name
2215 * @if_sid: interface SID
2216 */
2217 int security_netif_sid(char *name, u32 *if_sid)
2218 {
2219 int rc = 0;
2220 struct ocontext *c;
2221
2222 read_lock(&policy_rwlock);
2223
2224 c = policydb.ocontexts[OCON_NETIF];
2225 while (c) {
2226 if (strcmp(name, c->u.name) == 0)
2227 break;
2228 c = c->next;
2229 }
2230
2231 if (c) {
2232 if (!c->sid[0] || !c->sid[1]) {
2233 rc = sidtab_context_to_sid(&sidtab,
2234 &c->context[0],
2235 &c->sid[0]);
2236 if (rc)
2237 goto out;
2238 rc = sidtab_context_to_sid(&sidtab,
2239 &c->context[1],
2240 &c->sid[1]);
2241 if (rc)
2242 goto out;
2243 }
2244 *if_sid = c->sid[0];
2245 } else
2246 *if_sid = SECINITSID_NETIF;
2247
2248 out:
2249 read_unlock(&policy_rwlock);
2250 return rc;
2251 }
2252
2253 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2254 {
2255 int i, fail = 0;
2256
2257 for (i = 0; i < 4; i++)
2258 if (addr[i] != (input[i] & mask[i])) {
2259 fail = 1;
2260 break;
2261 }
2262
2263 return !fail;
2264 }
2265
2266 /**
2267 * security_node_sid - Obtain the SID for a node (host).
2268 * @domain: communication domain aka address family
2269 * @addrp: address
2270 * @addrlen: address length in bytes
2271 * @out_sid: security identifier
2272 */
2273 int security_node_sid(u16 domain,
2274 void *addrp,
2275 u32 addrlen,
2276 u32 *out_sid)
2277 {
2278 int rc;
2279 struct ocontext *c;
2280
2281 read_lock(&policy_rwlock);
2282
2283 switch (domain) {
2284 case AF_INET: {
2285 u32 addr;
2286
2287 rc = -EINVAL;
2288 if (addrlen != sizeof(u32))
2289 goto out;
2290
2291 addr = *((u32 *)addrp);
2292
2293 c = policydb.ocontexts[OCON_NODE];
2294 while (c) {
2295 if (c->u.node.addr == (addr & c->u.node.mask))
2296 break;
2297 c = c->next;
2298 }
2299 break;
2300 }
2301
2302 case AF_INET6:
2303 rc = -EINVAL;
2304 if (addrlen != sizeof(u64) * 2)
2305 goto out;
2306 c = policydb.ocontexts[OCON_NODE6];
2307 while (c) {
2308 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2309 c->u.node6.mask))
2310 break;
2311 c = c->next;
2312 }
2313 break;
2314
2315 default:
2316 rc = 0;
2317 *out_sid = SECINITSID_NODE;
2318 goto out;
2319 }
2320
2321 if (c) {
2322 if (!c->sid[0]) {
2323 rc = sidtab_context_to_sid(&sidtab,
2324 &c->context[0],
2325 &c->sid[0]);
2326 if (rc)
2327 goto out;
2328 }
2329 *out_sid = c->sid[0];
2330 } else {
2331 *out_sid = SECINITSID_NODE;
2332 }
2333
2334 rc = 0;
2335 out:
2336 read_unlock(&policy_rwlock);
2337 return rc;
2338 }
2339
2340 #define SIDS_NEL 25
2341
2342 /**
2343 * security_get_user_sids - Obtain reachable SIDs for a user.
2344 * @fromsid: starting SID
2345 * @username: username
2346 * @sids: array of reachable SIDs for user
2347 * @nel: number of elements in @sids
2348 *
2349 * Generate the set of SIDs for legal security contexts
2350 * for a given user that can be reached by @fromsid.
2351 * Set *@sids to point to a dynamically allocated
2352 * array containing the set of SIDs. Set *@nel to the
2353 * number of elements in the array.
2354 */
2355
2356 int security_get_user_sids(u32 fromsid,
2357 char *username,
2358 u32 **sids,
2359 u32 *nel)
2360 {
2361 struct context *fromcon, usercon;
2362 u32 *mysids = NULL, *mysids2, sid;
2363 u32 mynel = 0, maxnel = SIDS_NEL;
2364 struct user_datum *user;
2365 struct role_datum *role;
2366 struct ebitmap_node *rnode, *tnode;
2367 int rc = 0, i, j;
2368
2369 *sids = NULL;
2370 *nel = 0;
2371
2372 if (!ss_initialized)
2373 goto out;
2374
2375 read_lock(&policy_rwlock);
2376
2377 context_init(&usercon);
2378
2379 rc = -EINVAL;
2380 fromcon = sidtab_search(&sidtab, fromsid);
2381 if (!fromcon)
2382 goto out_unlock;
2383
2384 rc = -EINVAL;
2385 user = hashtab_search(policydb.p_users.table, username);
2386 if (!user)
2387 goto out_unlock;
2388
2389 usercon.user = user->value;
2390
2391 rc = -ENOMEM;
2392 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2393 if (!mysids)
2394 goto out_unlock;
2395
2396 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2397 role = policydb.role_val_to_struct[i];
2398 usercon.role = i + 1;
2399 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2400 usercon.type = j + 1;
2401
2402 if (mls_setup_user_range(fromcon, user, &usercon))
2403 continue;
2404
2405 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2406 if (rc)
2407 goto out_unlock;
2408 if (mynel < maxnel) {
2409 mysids[mynel++] = sid;
2410 } else {
2411 rc = -ENOMEM;
2412 maxnel += SIDS_NEL;
2413 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2414 if (!mysids2)
2415 goto out_unlock;
2416 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2417 kfree(mysids);
2418 mysids = mysids2;
2419 mysids[mynel++] = sid;
2420 }
2421 }
2422 }
2423 rc = 0;
2424 out_unlock:
2425 read_unlock(&policy_rwlock);
2426 if (rc || !mynel) {
2427 kfree(mysids);
2428 goto out;
2429 }
2430
2431 rc = -ENOMEM;
2432 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2433 if (!mysids2) {
2434 kfree(mysids);
2435 goto out;
2436 }
2437 for (i = 0, j = 0; i < mynel; i++) {
2438 struct av_decision dummy_avd;
2439 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2440 SECCLASS_PROCESS, /* kernel value */
2441 PROCESS__TRANSITION, AVC_STRICT,
2442 &dummy_avd);
2443 if (!rc)
2444 mysids2[j++] = mysids[i];
2445 cond_resched();
2446 }
2447 rc = 0;
2448 kfree(mysids);
2449 *sids = mysids2;
2450 *nel = j;
2451 out:
2452 return rc;
2453 }
2454
2455 /**
2456 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2457 * @fstype: filesystem type
2458 * @path: path from root of mount
2459 * @sclass: file security class
2460 * @sid: SID for path
2461 *
2462 * Obtain a SID to use for a file in a filesystem that
2463 * cannot support xattr or use a fixed labeling behavior like
2464 * transition SIDs or task SIDs.
2465 *
2466 * The caller must acquire the policy_rwlock before calling this function.
2467 */
2468 static inline int __security_genfs_sid(const char *fstype,
2469 char *path,
2470 u16 orig_sclass,
2471 u32 *sid)
2472 {
2473 int len;
2474 u16 sclass;
2475 struct genfs *genfs;
2476 struct ocontext *c;
2477 int rc, cmp = 0;
2478
2479 while (path[0] == '/' && path[1] == '/')
2480 path++;
2481
2482 sclass = unmap_class(orig_sclass);
2483 *sid = SECINITSID_UNLABELED;
2484
2485 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2486 cmp = strcmp(fstype, genfs->fstype);
2487 if (cmp <= 0)
2488 break;
2489 }
2490
2491 rc = -ENOENT;
2492 if (!genfs || cmp)
2493 goto out;
2494
2495 for (c = genfs->head; c; c = c->next) {
2496 len = strlen(c->u.name);
2497 if ((!c->v.sclass || sclass == c->v.sclass) &&
2498 (strncmp(c->u.name, path, len) == 0))
2499 break;
2500 }
2501
2502 rc = -ENOENT;
2503 if (!c)
2504 goto out;
2505
2506 if (!c->sid[0]) {
2507 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2508 if (rc)
2509 goto out;
2510 }
2511
2512 *sid = c->sid[0];
2513 rc = 0;
2514 out:
2515 return rc;
2516 }
2517
2518 /**
2519 * security_genfs_sid - Obtain a SID for a file in a filesystem
2520 * @fstype: filesystem type
2521 * @path: path from root of mount
2522 * @sclass: file security class
2523 * @sid: SID for path
2524 *
2525 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2526 * it afterward.
2527 */
2528 int security_genfs_sid(const char *fstype,
2529 char *path,
2530 u16 orig_sclass,
2531 u32 *sid)
2532 {
2533 int retval;
2534
2535 read_lock(&policy_rwlock);
2536 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2537 read_unlock(&policy_rwlock);
2538 return retval;
2539 }
2540
2541 /**
2542 * security_fs_use - Determine how to handle labeling for a filesystem.
2543 * @sb: superblock in question
2544 */
2545 int security_fs_use(struct super_block *sb)
2546 {
2547 int rc = 0;
2548 struct ocontext *c;
2549 struct superblock_security_struct *sbsec = sb->s_security;
2550 const char *fstype = sb->s_type->name;
2551
2552 read_lock(&policy_rwlock);
2553
2554 c = policydb.ocontexts[OCON_FSUSE];
2555 while (c) {
2556 if (strcmp(fstype, c->u.name) == 0)
2557 break;
2558 c = c->next;
2559 }
2560
2561 if (c) {
2562 sbsec->behavior = c->v.behavior;
2563 if (!c->sid[0]) {
2564 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2565 &c->sid[0]);
2566 if (rc)
2567 goto out;
2568 }
2569 sbsec->sid = c->sid[0];
2570 } else {
2571 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2572 &sbsec->sid);
2573 if (rc) {
2574 sbsec->behavior = SECURITY_FS_USE_NONE;
2575 rc = 0;
2576 } else {
2577 sbsec->behavior = SECURITY_FS_USE_GENFS;
2578 }
2579 }
2580
2581 out:
2582 read_unlock(&policy_rwlock);
2583 return rc;
2584 }
2585
2586 int security_get_bools(int *len, char ***names, int **values)
2587 {
2588 int i, rc;
2589
2590 read_lock(&policy_rwlock);
2591 *names = NULL;
2592 *values = NULL;
2593
2594 rc = 0;
2595 *len = policydb.p_bools.nprim;
2596 if (!*len)
2597 goto out;
2598
2599 rc = -ENOMEM;
2600 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2601 if (!*names)
2602 goto err;
2603
2604 rc = -ENOMEM;
2605 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2606 if (!*values)
2607 goto err;
2608
2609 for (i = 0; i < *len; i++) {
2610 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2611
2612 rc = -ENOMEM;
2613 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2614 if (!(*names)[i])
2615 goto err;
2616 }
2617 rc = 0;
2618 out:
2619 read_unlock(&policy_rwlock);
2620 return rc;
2621 err:
2622 if (*names) {
2623 for (i = 0; i < *len; i++)
2624 kfree((*names)[i]);
2625 }
2626 kfree(*values);
2627 goto out;
2628 }
2629
2630
2631 int security_set_bools(int len, int *values)
2632 {
2633 int i, rc;
2634 int lenp, seqno = 0;
2635 struct cond_node *cur;
2636
2637 write_lock_irq(&policy_rwlock);
2638
2639 rc = -EFAULT;
2640 lenp = policydb.p_bools.nprim;
2641 if (len != lenp)
2642 goto out;
2643
2644 for (i = 0; i < len; i++) {
2645 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2646 audit_log(current->audit_context, GFP_ATOMIC,
2647 AUDIT_MAC_CONFIG_CHANGE,
2648 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2649 sym_name(&policydb, SYM_BOOLS, i),
2650 !!values[i],
2651 policydb.bool_val_to_struct[i]->state,
2652 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2653 audit_get_sessionid(current));
2654 }
2655 if (values[i])
2656 policydb.bool_val_to_struct[i]->state = 1;
2657 else
2658 policydb.bool_val_to_struct[i]->state = 0;
2659 }
2660
2661 for (cur = policydb.cond_list; cur; cur = cur->next) {
2662 rc = evaluate_cond_node(&policydb, cur);
2663 if (rc)
2664 goto out;
2665 }
2666
2667 seqno = ++latest_granting;
2668 rc = 0;
2669 out:
2670 write_unlock_irq(&policy_rwlock);
2671 if (!rc) {
2672 avc_ss_reset(seqno);
2673 selnl_notify_policyload(seqno);
2674 selinux_status_update_policyload(seqno);
2675 selinux_xfrm_notify_policyload();
2676 }
2677 return rc;
2678 }
2679
2680 int security_get_bool_value(int index)
2681 {
2682 int rc;
2683 int len;
2684
2685 read_lock(&policy_rwlock);
2686
2687 rc = -EFAULT;
2688 len = policydb.p_bools.nprim;
2689 if (index >= len)
2690 goto out;
2691
2692 rc = policydb.bool_val_to_struct[index]->state;
2693 out:
2694 read_unlock(&policy_rwlock);
2695 return rc;
2696 }
2697
2698 static int security_preserve_bools(struct policydb *p)
2699 {
2700 int rc, nbools = 0, *bvalues = NULL, i;
2701 char **bnames = NULL;
2702 struct cond_bool_datum *booldatum;
2703 struct cond_node *cur;
2704
2705 rc = security_get_bools(&nbools, &bnames, &bvalues);
2706 if (rc)
2707 goto out;
2708 for (i = 0; i < nbools; i++) {
2709 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2710 if (booldatum)
2711 booldatum->state = bvalues[i];
2712 }
2713 for (cur = p->cond_list; cur; cur = cur->next) {
2714 rc = evaluate_cond_node(p, cur);
2715 if (rc)
2716 goto out;
2717 }
2718
2719 out:
2720 if (bnames) {
2721 for (i = 0; i < nbools; i++)
2722 kfree(bnames[i]);
2723 }
2724 kfree(bnames);
2725 kfree(bvalues);
2726 return rc;
2727 }
2728
2729 /*
2730 * security_sid_mls_copy() - computes a new sid based on the given
2731 * sid and the mls portion of mls_sid.
2732 */
2733 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2734 {
2735 struct context *context1;
2736 struct context *context2;
2737 struct context newcon;
2738 char *s;
2739 u32 len;
2740 int rc;
2741
2742 rc = 0;
2743 if (!ss_initialized || !policydb.mls_enabled) {
2744 *new_sid = sid;
2745 goto out;
2746 }
2747
2748 context_init(&newcon);
2749
2750 read_lock(&policy_rwlock);
2751
2752 rc = -EINVAL;
2753 context1 = sidtab_search(&sidtab, sid);
2754 if (!context1) {
2755 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2756 __func__, sid);
2757 goto out_unlock;
2758 }
2759
2760 rc = -EINVAL;
2761 context2 = sidtab_search(&sidtab, mls_sid);
2762 if (!context2) {
2763 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2764 __func__, mls_sid);
2765 goto out_unlock;
2766 }
2767
2768 newcon.user = context1->user;
2769 newcon.role = context1->role;
2770 newcon.type = context1->type;
2771 rc = mls_context_cpy(&newcon, context2);
2772 if (rc)
2773 goto out_unlock;
2774
2775 /* Check the validity of the new context. */
2776 if (!policydb_context_isvalid(&policydb, &newcon)) {
2777 rc = convert_context_handle_invalid_context(&newcon);
2778 if (rc) {
2779 if (!context_struct_to_string(&newcon, &s, &len)) {
2780 audit_log(current->audit_context,
2781 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2782 "op=security_sid_mls_copy "
2783 "invalid_context=%s", s);
2784 kfree(s);
2785 }
2786 goto out_unlock;
2787 }
2788 }
2789
2790 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2791 out_unlock:
2792 read_unlock(&policy_rwlock);
2793 context_destroy(&newcon);
2794 out:
2795 return rc;
2796 }
2797
2798 /**
2799 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2800 * @nlbl_sid: NetLabel SID
2801 * @nlbl_type: NetLabel labeling protocol type
2802 * @xfrm_sid: XFRM SID
2803 *
2804 * Description:
2805 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2806 * resolved into a single SID it is returned via @peer_sid and the function
2807 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2808 * returns a negative value. A table summarizing the behavior is below:
2809 *
2810 * | function return | @sid
2811 * ------------------------------+-----------------+-----------------
2812 * no peer labels | 0 | SECSID_NULL
2813 * single peer label | 0 | <peer_label>
2814 * multiple, consistent labels | 0 | <peer_label>
2815 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2816 *
2817 */
2818 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2819 u32 xfrm_sid,
2820 u32 *peer_sid)
2821 {
2822 int rc;
2823 struct context *nlbl_ctx;
2824 struct context *xfrm_ctx;
2825
2826 *peer_sid = SECSID_NULL;
2827
2828 /* handle the common (which also happens to be the set of easy) cases
2829 * right away, these two if statements catch everything involving a
2830 * single or absent peer SID/label */
2831 if (xfrm_sid == SECSID_NULL) {
2832 *peer_sid = nlbl_sid;
2833 return 0;
2834 }
2835 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2836 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2837 * is present */
2838 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2839 *peer_sid = xfrm_sid;
2840 return 0;
2841 }
2842
2843 /* we don't need to check ss_initialized here since the only way both
2844 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2845 * security server was initialized and ss_initialized was true */
2846 if (!policydb.mls_enabled)
2847 return 0;
2848
2849 read_lock(&policy_rwlock);
2850
2851 rc = -EINVAL;
2852 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2853 if (!nlbl_ctx) {
2854 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2855 __func__, nlbl_sid);
2856 goto out;
2857 }
2858 rc = -EINVAL;
2859 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2860 if (!xfrm_ctx) {
2861 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2862 __func__, xfrm_sid);
2863 goto out;
2864 }
2865 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2866 if (rc)
2867 goto out;
2868
2869 /* at present NetLabel SIDs/labels really only carry MLS
2870 * information so if the MLS portion of the NetLabel SID
2871 * matches the MLS portion of the labeled XFRM SID/label
2872 * then pass along the XFRM SID as it is the most
2873 * expressive */
2874 *peer_sid = xfrm_sid;
2875 out:
2876 read_unlock(&policy_rwlock);
2877 return rc;
2878 }
2879
2880 static int get_classes_callback(void *k, void *d, void *args)
2881 {
2882 struct class_datum *datum = d;
2883 char *name = k, **classes = args;
2884 int value = datum->value - 1;
2885
2886 classes[value] = kstrdup(name, GFP_ATOMIC);
2887 if (!classes[value])
2888 return -ENOMEM;
2889
2890 return 0;
2891 }
2892
2893 int security_get_classes(char ***classes, int *nclasses)
2894 {
2895 int rc;
2896
2897 read_lock(&policy_rwlock);
2898
2899 rc = -ENOMEM;
2900 *nclasses = policydb.p_classes.nprim;
2901 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2902 if (!*classes)
2903 goto out;
2904
2905 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2906 *classes);
2907 if (rc) {
2908 int i;
2909 for (i = 0; i < *nclasses; i++)
2910 kfree((*classes)[i]);
2911 kfree(*classes);
2912 }
2913
2914 out:
2915 read_unlock(&policy_rwlock);
2916 return rc;
2917 }
2918
2919 static int get_permissions_callback(void *k, void *d, void *args)
2920 {
2921 struct perm_datum *datum = d;
2922 char *name = k, **perms = args;
2923 int value = datum->value - 1;
2924
2925 perms[value] = kstrdup(name, GFP_ATOMIC);
2926 if (!perms[value])
2927 return -ENOMEM;
2928
2929 return 0;
2930 }
2931
2932 int security_get_permissions(char *class, char ***perms, int *nperms)
2933 {
2934 int rc, i;
2935 struct class_datum *match;
2936
2937 read_lock(&policy_rwlock);
2938
2939 rc = -EINVAL;
2940 match = hashtab_search(policydb.p_classes.table, class);
2941 if (!match) {
2942 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2943 __func__, class);
2944 goto out;
2945 }
2946
2947 rc = -ENOMEM;
2948 *nperms = match->permissions.nprim;
2949 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2950 if (!*perms)
2951 goto out;
2952
2953 if (match->comdatum) {
2954 rc = hashtab_map(match->comdatum->permissions.table,
2955 get_permissions_callback, *perms);
2956 if (rc)
2957 goto err;
2958 }
2959
2960 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2961 *perms);
2962 if (rc)
2963 goto err;
2964
2965 out:
2966 read_unlock(&policy_rwlock);
2967 return rc;
2968
2969 err:
2970 read_unlock(&policy_rwlock);
2971 for (i = 0; i < *nperms; i++)
2972 kfree((*perms)[i]);
2973 kfree(*perms);
2974 return rc;
2975 }
2976
2977 int security_get_reject_unknown(void)
2978 {
2979 return policydb.reject_unknown;
2980 }
2981
2982 int security_get_allow_unknown(void)
2983 {
2984 return policydb.allow_unknown;
2985 }
2986
2987 /**
2988 * security_policycap_supported - Check for a specific policy capability
2989 * @req_cap: capability
2990 *
2991 * Description:
2992 * This function queries the currently loaded policy to see if it supports the
2993 * capability specified by @req_cap. Returns true (1) if the capability is
2994 * supported, false (0) if it isn't supported.
2995 *
2996 */
2997 int security_policycap_supported(unsigned int req_cap)
2998 {
2999 int rc;
3000
3001 read_lock(&policy_rwlock);
3002 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3003 read_unlock(&policy_rwlock);
3004
3005 return rc;
3006 }
3007
3008 struct selinux_audit_rule {
3009 u32 au_seqno;
3010 struct context au_ctxt;
3011 };
3012
3013 void selinux_audit_rule_free(void *vrule)
3014 {
3015 struct selinux_audit_rule *rule = vrule;
3016
3017 if (rule) {
3018 context_destroy(&rule->au_ctxt);
3019 kfree(rule);
3020 }
3021 }
3022
3023 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3024 {
3025 struct selinux_audit_rule *tmprule;
3026 struct role_datum *roledatum;
3027 struct type_datum *typedatum;
3028 struct user_datum *userdatum;
3029 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3030 int rc = 0;
3031
3032 *rule = NULL;
3033
3034 if (!ss_initialized)
3035 return -EOPNOTSUPP;
3036
3037 switch (field) {
3038 case AUDIT_SUBJ_USER:
3039 case AUDIT_SUBJ_ROLE:
3040 case AUDIT_SUBJ_TYPE:
3041 case AUDIT_OBJ_USER:
3042 case AUDIT_OBJ_ROLE:
3043 case AUDIT_OBJ_TYPE:
3044 /* only 'equals' and 'not equals' fit user, role, and type */
3045 if (op != Audit_equal && op != Audit_not_equal)
3046 return -EINVAL;
3047 break;
3048 case AUDIT_SUBJ_SEN:
3049 case AUDIT_SUBJ_CLR:
3050 case AUDIT_OBJ_LEV_LOW:
3051 case AUDIT_OBJ_LEV_HIGH:
3052 /* we do not allow a range, indicated by the presence of '-' */
3053 if (strchr(rulestr, '-'))
3054 return -EINVAL;
3055 break;
3056 default:
3057 /* only the above fields are valid */
3058 return -EINVAL;
3059 }
3060
3061 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3062 if (!tmprule)
3063 return -ENOMEM;
3064
3065 context_init(&tmprule->au_ctxt);
3066
3067 read_lock(&policy_rwlock);
3068
3069 tmprule->au_seqno = latest_granting;
3070
3071 switch (field) {
3072 case AUDIT_SUBJ_USER:
3073 case AUDIT_OBJ_USER:
3074 rc = -EINVAL;
3075 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3076 if (!userdatum)
3077 goto out;
3078 tmprule->au_ctxt.user = userdatum->value;
3079 break;
3080 case AUDIT_SUBJ_ROLE:
3081 case AUDIT_OBJ_ROLE:
3082 rc = -EINVAL;
3083 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3084 if (!roledatum)
3085 goto out;
3086 tmprule->au_ctxt.role = roledatum->value;
3087 break;
3088 case AUDIT_SUBJ_TYPE:
3089 case AUDIT_OBJ_TYPE:
3090 rc = -EINVAL;
3091 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3092 if (!typedatum)
3093 goto out;
3094 tmprule->au_ctxt.type = typedatum->value;
3095 break;
3096 case AUDIT_SUBJ_SEN:
3097 case AUDIT_SUBJ_CLR:
3098 case AUDIT_OBJ_LEV_LOW:
3099 case AUDIT_OBJ_LEV_HIGH:
3100 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3101 if (rc)
3102 goto out;
3103 break;
3104 }
3105 rc = 0;
3106 out:
3107 read_unlock(&policy_rwlock);
3108
3109 if (rc) {
3110 selinux_audit_rule_free(tmprule);
3111 tmprule = NULL;
3112 }
3113
3114 *rule = tmprule;
3115
3116 return rc;
3117 }
3118
3119 /* Check to see if the rule contains any selinux fields */
3120 int selinux_audit_rule_known(struct audit_krule *rule)
3121 {
3122 int i;
3123
3124 for (i = 0; i < rule->field_count; i++) {
3125 struct audit_field *f = &rule->fields[i];
3126 switch (f->type) {
3127 case AUDIT_SUBJ_USER:
3128 case AUDIT_SUBJ_ROLE:
3129 case AUDIT_SUBJ_TYPE:
3130 case AUDIT_SUBJ_SEN:
3131 case AUDIT_SUBJ_CLR:
3132 case AUDIT_OBJ_USER:
3133 case AUDIT_OBJ_ROLE:
3134 case AUDIT_OBJ_TYPE:
3135 case AUDIT_OBJ_LEV_LOW:
3136 case AUDIT_OBJ_LEV_HIGH:
3137 return 1;
3138 }
3139 }
3140
3141 return 0;
3142 }
3143
3144 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3145 struct audit_context *actx)
3146 {
3147 struct context *ctxt;
3148 struct mls_level *level;
3149 struct selinux_audit_rule *rule = vrule;
3150 int match = 0;
3151
3152 if (unlikely(!rule)) {
3153 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3154 return -ENOENT;
3155 }
3156
3157 read_lock(&policy_rwlock);
3158
3159 if (rule->au_seqno < latest_granting) {
3160 match = -ESTALE;
3161 goto out;
3162 }
3163
3164 ctxt = sidtab_search(&sidtab, sid);
3165 if (unlikely(!ctxt)) {
3166 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3167 sid);
3168 match = -ENOENT;
3169 goto out;
3170 }
3171
3172 /* a field/op pair that is not caught here will simply fall through
3173 without a match */
3174 switch (field) {
3175 case AUDIT_SUBJ_USER:
3176 case AUDIT_OBJ_USER:
3177 switch (op) {
3178 case Audit_equal:
3179 match = (ctxt->user == rule->au_ctxt.user);
3180 break;
3181 case Audit_not_equal:
3182 match = (ctxt->user != rule->au_ctxt.user);
3183 break;
3184 }
3185 break;
3186 case AUDIT_SUBJ_ROLE:
3187 case AUDIT_OBJ_ROLE:
3188 switch (op) {
3189 case Audit_equal:
3190 match = (ctxt->role == rule->au_ctxt.role);
3191 break;
3192 case Audit_not_equal:
3193 match = (ctxt->role != rule->au_ctxt.role);
3194 break;
3195 }
3196 break;
3197 case AUDIT_SUBJ_TYPE:
3198 case AUDIT_OBJ_TYPE:
3199 switch (op) {
3200 case Audit_equal:
3201 match = (ctxt->type == rule->au_ctxt.type);
3202 break;
3203 case Audit_not_equal:
3204 match = (ctxt->type != rule->au_ctxt.type);
3205 break;
3206 }
3207 break;
3208 case AUDIT_SUBJ_SEN:
3209 case AUDIT_SUBJ_CLR:
3210 case AUDIT_OBJ_LEV_LOW:
3211 case AUDIT_OBJ_LEV_HIGH:
3212 level = ((field == AUDIT_SUBJ_SEN ||
3213 field == AUDIT_OBJ_LEV_LOW) ?
3214 &ctxt->range.level[0] : &ctxt->range.level[1]);
3215 switch (op) {
3216 case Audit_equal:
3217 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3218 level);
3219 break;
3220 case Audit_not_equal:
3221 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3222 level);
3223 break;
3224 case Audit_lt:
3225 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3226 level) &&
3227 !mls_level_eq(&rule->au_ctxt.range.level[0],
3228 level));
3229 break;
3230 case Audit_le:
3231 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3232 level);
3233 break;
3234 case Audit_gt:
3235 match = (mls_level_dom(level,
3236 &rule->au_ctxt.range.level[0]) &&
3237 !mls_level_eq(level,
3238 &rule->au_ctxt.range.level[0]));
3239 break;
3240 case Audit_ge:
3241 match = mls_level_dom(level,
3242 &rule->au_ctxt.range.level[0]);
3243 break;
3244 }
3245 }
3246
3247 out:
3248 read_unlock(&policy_rwlock);
3249 return match;
3250 }
3251
3252 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3253
3254 static int aurule_avc_callback(u32 event)
3255 {
3256 int err = 0;
3257
3258 if (event == AVC_CALLBACK_RESET && aurule_callback)
3259 err = aurule_callback();
3260 return err;
3261 }
3262
3263 static int __init aurule_init(void)
3264 {
3265 int err;
3266
3267 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3268 if (err)
3269 panic("avc_add_callback() failed, error %d\n", err);
3270
3271 return err;
3272 }
3273 __initcall(aurule_init);
3274
3275 #ifdef CONFIG_NETLABEL
3276 /**
3277 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3278 * @secattr: the NetLabel packet security attributes
3279 * @sid: the SELinux SID
3280 *
3281 * Description:
3282 * Attempt to cache the context in @ctx, which was derived from the packet in
3283 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3284 * already been initialized.
3285 *
3286 */
3287 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3288 u32 sid)
3289 {
3290 u32 *sid_cache;
3291
3292 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3293 if (sid_cache == NULL)
3294 return;
3295 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3296 if (secattr->cache == NULL) {
3297 kfree(sid_cache);
3298 return;
3299 }
3300
3301 *sid_cache = sid;
3302 secattr->cache->free = kfree;
3303 secattr->cache->data = sid_cache;
3304 secattr->flags |= NETLBL_SECATTR_CACHE;
3305 }
3306
3307 /**
3308 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3309 * @secattr: the NetLabel packet security attributes
3310 * @sid: the SELinux SID
3311 *
3312 * Description:
3313 * Convert the given NetLabel security attributes in @secattr into a
3314 * SELinux SID. If the @secattr field does not contain a full SELinux
3315 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3316 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3317 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3318 * conversion for future lookups. Returns zero on success, negative values on
3319 * failure.
3320 *
3321 */
3322 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3323 u32 *sid)
3324 {
3325 int rc;
3326 struct context *ctx;
3327 struct context ctx_new;
3328
3329 if (!ss_initialized) {
3330 *sid = SECSID_NULL;
3331 return 0;
3332 }
3333
3334 read_lock(&policy_rwlock);
3335
3336 if (secattr->flags & NETLBL_SECATTR_CACHE)
3337 *sid = *(u32 *)secattr->cache->data;
3338 else if (secattr->flags & NETLBL_SECATTR_SECID)
3339 *sid = secattr->attr.secid;
3340 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3341 rc = -EIDRM;
3342 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3343 if (ctx == NULL)
3344 goto out;
3345
3346 context_init(&ctx_new);
3347 ctx_new.user = ctx->user;
3348 ctx_new.role = ctx->role;
3349 ctx_new.type = ctx->type;
3350 mls_import_netlbl_lvl(&ctx_new, secattr);
3351 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3352 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3353 if (rc)
3354 goto out;
3355 }
3356 rc = -EIDRM;
3357 if (!mls_context_isvalid(&policydb, &ctx_new))
3358 goto out_free;
3359
3360 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3361 if (rc)
3362 goto out_free;
3363
3364 security_netlbl_cache_add(secattr, *sid);
3365
3366 ebitmap_destroy(&ctx_new.range.level[0].cat);
3367 } else
3368 *sid = SECSID_NULL;
3369
3370 read_unlock(&policy_rwlock);
3371 return 0;
3372 out_free:
3373 ebitmap_destroy(&ctx_new.range.level[0].cat);
3374 out:
3375 read_unlock(&policy_rwlock);
3376 return rc;
3377 }
3378
3379 /**
3380 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3381 * @sid: the SELinux SID
3382 * @secattr: the NetLabel packet security attributes
3383 *
3384 * Description:
3385 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3386 * Returns zero on success, negative values on failure.
3387 *
3388 */
3389 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3390 {
3391 int rc;
3392 struct context *ctx;
3393
3394 if (!ss_initialized)
3395 return 0;
3396
3397 read_lock(&policy_rwlock);
3398
3399 rc = -ENOENT;
3400 ctx = sidtab_search(&sidtab, sid);
3401 if (ctx == NULL)
3402 goto out;
3403
3404 rc = -ENOMEM;
3405 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3406 GFP_ATOMIC);
3407 if (secattr->domain == NULL)
3408 goto out;
3409
3410 secattr->attr.secid = sid;
3411 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3412 mls_export_netlbl_lvl(ctx, secattr);
3413 rc = mls_export_netlbl_cat(ctx, secattr);
3414 out:
3415 read_unlock(&policy_rwlock);
3416 return rc;
3417 }
3418 #endif /* CONFIG_NETLABEL */
3419
3420 /**
3421 * security_read_policy - read the policy.
3422 * @data: binary policy data
3423 * @len: length of data in bytes
3424 *
3425 */
3426 int security_read_policy(void **data, size_t *len)
3427 {
3428 int rc;
3429 struct policy_file fp;
3430
3431 if (!ss_initialized)
3432 return -EINVAL;
3433
3434 *len = security_policydb_len();
3435
3436 *data = vmalloc_user(*len);
3437 if (!*data)
3438 return -ENOMEM;
3439
3440 fp.data = *data;
3441 fp.len = *len;
3442
3443 read_lock(&policy_rwlock);
3444 rc = policydb_write(&policydb, &fp);
3445 read_unlock(&policy_rwlock);
3446
3447 if (rc)
3448 return rc;
3449
3450 *len = (unsigned long)fp.data - (unsigned long)*data;
3451 return 0;
3452
3453 }
Linux with added FPC-III support