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of: MSI: Simplify irqdomain lookup
[linux/fpc-iii.git] / security / selinux / ss / services.c
blobebb5eb3c318c789922da4851b1b0507f28e7f831
1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul@paul-moore.com>
17 *
18 * Added support for NetLabel
19 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75 int selinux_policycap_alwaysnetwork;
76
77 static DEFINE_RWLOCK(policy_rwlock);
78
79 static struct sidtab sidtab;
80 struct policydb policydb;
81 int ss_initialized;
82
83 /*
84 * The largest sequence number that has been used when
85 * providing an access decision to the access vector cache.
86 * The sequence number only changes when a policy change
87 * occurs.
88 */
89 static u32 latest_granting;
90
91 /* Forward declaration. */
92 static int context_struct_to_string(struct context *context, char **scontext,
93 u32 *scontext_len);
94
95 static void context_struct_compute_av(struct context *scontext,
96 struct context *tcontext,
97 u16 tclass,
98 struct av_decision *avd,
99 struct extended_perms *xperms);
100
101 struct selinux_mapping {
102 u16 value; /* policy value */
103 unsigned num_perms;
104 u32 perms[sizeof(u32) * 8];
105 };
106
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109
110 static int selinux_set_mapping(struct policydb *pol,
111 struct security_class_mapping *map,
112 struct selinux_mapping **out_map_p,
113 u16 *out_map_size)
114 {
115 struct selinux_mapping *out_map = NULL;
116 size_t size = sizeof(struct selinux_mapping);
117 u16 i, j;
118 unsigned k;
119 bool print_unknown_handle = false;
120
121 /* Find number of classes in the input mapping */
122 if (!map)
123 return -EINVAL;
124 i = 0;
125 while (map[i].name)
126 i++;
127
128 /* Allocate space for the class records, plus one for class zero */
129 out_map = kcalloc(++i, size, GFP_ATOMIC);
130 if (!out_map)
131 return -ENOMEM;
132
133 /* Store the raw class and permission values */
134 j = 0;
135 while (map[j].name) {
136 struct security_class_mapping *p_in = map + (j++);
137 struct selinux_mapping *p_out = out_map + j;
138
139 /* An empty class string skips ahead */
140 if (!strcmp(p_in->name, "")) {
141 p_out->num_perms = 0;
142 continue;
143 }
144
145 p_out->value = string_to_security_class(pol, p_in->name);
146 if (!p_out->value) {
147 printk(KERN_INFO
148 "SELinux: Class %s not defined in policy.\n",
149 p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 p_out->num_perms = 0;
153 print_unknown_handle = true;
154 continue;
155 }
156
157 k = 0;
158 while (p_in->perms && p_in->perms[k]) {
159 /* An empty permission string skips ahead */
160 if (!*p_in->perms[k]) {
161 k++;
162 continue;
163 }
164 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 p_in->perms[k]);
166 if (!p_out->perms[k]) {
167 printk(KERN_INFO
168 "SELinux: Permission %s in class %s not defined in policy.\n",
169 p_in->perms[k], p_in->name);
170 if (pol->reject_unknown)
171 goto err;
172 print_unknown_handle = true;
173 }
174
175 k++;
176 }
177 p_out->num_perms = k;
178 }
179
180 if (print_unknown_handle)
181 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 pol->allow_unknown ? "allowed" : "denied");
183
184 *out_map_p = out_map;
185 *out_map_size = i;
186 return 0;
187 err:
188 kfree(out_map);
189 return -EINVAL;
190 }
191
192 /*
193 * Get real, policy values from mapped values
194 */
195
196 static u16 unmap_class(u16 tclass)
197 {
198 if (tclass < current_mapping_size)
199 return current_mapping[tclass].value;
200
201 return tclass;
202 }
203
204 /*
205 * Get kernel value for class from its policy value
206 */
207 static u16 map_class(u16 pol_value)
208 {
209 u16 i;
210
211 for (i = 1; i < current_mapping_size; i++) {
212 if (current_mapping[i].value == pol_value)
213 return i;
214 }
215
216 return SECCLASS_NULL;
217 }
218
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 int allow_unknown)
221 {
222 if (tclass < current_mapping_size) {
223 unsigned i, n = current_mapping[tclass].num_perms;
224 u32 result;
225
226 for (i = 0, result = 0; i < n; i++) {
227 if (avd->allowed & current_mapping[tclass].perms[i])
228 result |= 1<<i;
229 if (allow_unknown && !current_mapping[tclass].perms[i])
230 result |= 1<<i;
231 }
232 avd->allowed = result;
233
234 for (i = 0, result = 0; i < n; i++)
235 if (avd->auditallow & current_mapping[tclass].perms[i])
236 result |= 1<<i;
237 avd->auditallow = result;
238
239 for (i = 0, result = 0; i < n; i++) {
240 if (avd->auditdeny & current_mapping[tclass].perms[i])
241 result |= 1<<i;
242 if (!allow_unknown && !current_mapping[tclass].perms[i])
243 result |= 1<<i;
244 }
245 /*
246 * In case the kernel has a bug and requests a permission
247 * between num_perms and the maximum permission number, we
248 * should audit that denial
249 */
250 for (; i < (sizeof(u32)*8); i++)
251 result |= 1<<i;
252 avd->auditdeny = result;
253 }
254 }
255
256 int security_mls_enabled(void)
257 {
258 return policydb.mls_enabled;
259 }
260
261 /*
262 * Return the boolean value of a constraint expression
263 * when it is applied to the specified source and target
264 * security contexts.
265 *
266 * xcontext is a special beast... It is used by the validatetrans rules
267 * only. For these rules, scontext is the context before the transition,
268 * tcontext is the context after the transition, and xcontext is the context
269 * of the process performing the transition. All other callers of
270 * constraint_expr_eval should pass in NULL for xcontext.
271 */
272 static int constraint_expr_eval(struct context *scontext,
273 struct context *tcontext,
274 struct context *xcontext,
275 struct constraint_expr *cexpr)
276 {
277 u32 val1, val2;
278 struct context *c;
279 struct role_datum *r1, *r2;
280 struct mls_level *l1, *l2;
281 struct constraint_expr *e;
282 int s[CEXPR_MAXDEPTH];
283 int sp = -1;
284
285 for (e = cexpr; e; e = e->next) {
286 switch (e->expr_type) {
287 case CEXPR_NOT:
288 BUG_ON(sp < 0);
289 s[sp] = !s[sp];
290 break;
291 case CEXPR_AND:
292 BUG_ON(sp < 1);
293 sp--;
294 s[sp] &= s[sp + 1];
295 break;
296 case CEXPR_OR:
297 BUG_ON(sp < 1);
298 sp--;
299 s[sp] |= s[sp + 1];
300 break;
301 case CEXPR_ATTR:
302 if (sp == (CEXPR_MAXDEPTH - 1))
303 return 0;
304 switch (e->attr) {
305 case CEXPR_USER:
306 val1 = scontext->user;
307 val2 = tcontext->user;
308 break;
309 case CEXPR_TYPE:
310 val1 = scontext->type;
311 val2 = tcontext->type;
312 break;
313 case CEXPR_ROLE:
314 val1 = scontext->role;
315 val2 = tcontext->role;
316 r1 = policydb.role_val_to_struct[val1 - 1];
317 r2 = policydb.role_val_to_struct[val2 - 1];
318 switch (e->op) {
319 case CEXPR_DOM:
320 s[++sp] = ebitmap_get_bit(&r1->dominates,
321 val2 - 1);
322 continue;
323 case CEXPR_DOMBY:
324 s[++sp] = ebitmap_get_bit(&r2->dominates,
325 val1 - 1);
326 continue;
327 case CEXPR_INCOMP:
328 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 val2 - 1) &&
330 !ebitmap_get_bit(&r2->dominates,
331 val1 - 1));
332 continue;
333 default:
334 break;
335 }
336 break;
337 case CEXPR_L1L2:
338 l1 = &(scontext->range.level[0]);
339 l2 = &(tcontext->range.level[0]);
340 goto mls_ops;
341 case CEXPR_L1H2:
342 l1 = &(scontext->range.level[0]);
343 l2 = &(tcontext->range.level[1]);
344 goto mls_ops;
345 case CEXPR_H1L2:
346 l1 = &(scontext->range.level[1]);
347 l2 = &(tcontext->range.level[0]);
348 goto mls_ops;
349 case CEXPR_H1H2:
350 l1 = &(scontext->range.level[1]);
351 l2 = &(tcontext->range.level[1]);
352 goto mls_ops;
353 case CEXPR_L1H1:
354 l1 = &(scontext->range.level[0]);
355 l2 = &(scontext->range.level[1]);
356 goto mls_ops;
357 case CEXPR_L2H2:
358 l1 = &(tcontext->range.level[0]);
359 l2 = &(tcontext->range.level[1]);
360 goto mls_ops;
361 mls_ops:
362 switch (e->op) {
363 case CEXPR_EQ:
364 s[++sp] = mls_level_eq(l1, l2);
365 continue;
366 case CEXPR_NEQ:
367 s[++sp] = !mls_level_eq(l1, l2);
368 continue;
369 case CEXPR_DOM:
370 s[++sp] = mls_level_dom(l1, l2);
371 continue;
372 case CEXPR_DOMBY:
373 s[++sp] = mls_level_dom(l2, l1);
374 continue;
375 case CEXPR_INCOMP:
376 s[++sp] = mls_level_incomp(l2, l1);
377 continue;
378 default:
379 BUG();
380 return 0;
381 }
382 break;
383 default:
384 BUG();
385 return 0;
386 }
387
388 switch (e->op) {
389 case CEXPR_EQ:
390 s[++sp] = (val1 == val2);
391 break;
392 case CEXPR_NEQ:
393 s[++sp] = (val1 != val2);
394 break;
395 default:
396 BUG();
397 return 0;
398 }
399 break;
400 case CEXPR_NAMES:
401 if (sp == (CEXPR_MAXDEPTH-1))
402 return 0;
403 c = scontext;
404 if (e->attr & CEXPR_TARGET)
405 c = tcontext;
406 else if (e->attr & CEXPR_XTARGET) {
407 c = xcontext;
408 if (!c) {
409 BUG();
410 return 0;
411 }
412 }
413 if (e->attr & CEXPR_USER)
414 val1 = c->user;
415 else if (e->attr & CEXPR_ROLE)
416 val1 = c->role;
417 else if (e->attr & CEXPR_TYPE)
418 val1 = c->type;
419 else {
420 BUG();
421 return 0;
422 }
423
424 switch (e->op) {
425 case CEXPR_EQ:
426 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 break;
428 case CEXPR_NEQ:
429 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 break;
431 default:
432 BUG();
433 return 0;
434 }
435 break;
436 default:
437 BUG();
438 return 0;
439 }
440 }
441
442 BUG_ON(sp != 0);
443 return s[0];
444 }
445
446 /*
447 * security_dump_masked_av - dumps masked permissions during
448 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449 */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 struct perm_datum *pdatum = d;
453 char **permission_names = args;
454
455 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456
457 permission_names[pdatum->value - 1] = (char *)k;
458
459 return 0;
460 }
461
462 static void security_dump_masked_av(struct context *scontext,
463 struct context *tcontext,
464 u16 tclass,
465 u32 permissions,
466 const char *reason)
467 {
468 struct common_datum *common_dat;
469 struct class_datum *tclass_dat;
470 struct audit_buffer *ab;
471 char *tclass_name;
472 char *scontext_name = NULL;
473 char *tcontext_name = NULL;
474 char *permission_names[32];
475 int index;
476 u32 length;
477 bool need_comma = false;
478
479 if (!permissions)
480 return;
481
482 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 common_dat = tclass_dat->comdatum;
485
486 /* init permission_names */
487 if (common_dat &&
488 hashtab_map(common_dat->permissions.table,
489 dump_masked_av_helper, permission_names) < 0)
490 goto out;
491
492 if (hashtab_map(tclass_dat->permissions.table,
493 dump_masked_av_helper, permission_names) < 0)
494 goto out;
495
496 /* get scontext/tcontext in text form */
497 if (context_struct_to_string(scontext,
498 &scontext_name, &length) < 0)
499 goto out;
500
501 if (context_struct_to_string(tcontext,
502 &tcontext_name, &length) < 0)
503 goto out;
504
505 /* audit a message */
506 ab = audit_log_start(current->audit_context,
507 GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 if (!ab)
509 goto out;
510
511 audit_log_format(ab, "op=security_compute_av reason=%s "
512 "scontext=%s tcontext=%s tclass=%s perms=",
513 reason, scontext_name, tcontext_name, tclass_name);
514
515 for (index = 0; index < 32; index++) {
516 u32 mask = (1 << index);
517
518 if ((mask & permissions) == 0)
519 continue;
520
521 audit_log_format(ab, "%s%s",
522 need_comma ? "," : "",
523 permission_names[index]
524 ? permission_names[index] : "????");
525 need_comma = true;
526 }
527 audit_log_end(ab);
528 out:
529 /* release scontext/tcontext */
530 kfree(tcontext_name);
531 kfree(scontext_name);
532
533 return;
534 }
535
536 /*
537 * security_boundary_permission - drops violated permissions
538 * on boundary constraint.
539 */
540 static void type_attribute_bounds_av(struct context *scontext,
541 struct context *tcontext,
542 u16 tclass,
543 struct av_decision *avd)
544 {
545 struct context lo_scontext;
546 struct context lo_tcontext;
547 struct av_decision lo_avd;
548 struct type_datum *source;
549 struct type_datum *target;
550 u32 masked = 0;
551
552 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 scontext->type - 1);
554 BUG_ON(!source);
555
556 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557 tcontext->type - 1);
558 BUG_ON(!target);
559
560 if (source->bounds) {
561 memset(&lo_avd, 0, sizeof(lo_avd));
562
563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564 lo_scontext.type = source->bounds;
565
566 context_struct_compute_av(&lo_scontext,
567 tcontext,
568 tclass,
569 &lo_avd,
570 NULL);
571 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
572 return; /* no masked permission */
573 masked = ~lo_avd.allowed & avd->allowed;
574 }
575
576 if (target->bounds) {
577 memset(&lo_avd, 0, sizeof(lo_avd));
578
579 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
580 lo_tcontext.type = target->bounds;
581
582 context_struct_compute_av(scontext,
583 &lo_tcontext,
584 tclass,
585 &lo_avd,
586 NULL);
587 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
588 return; /* no masked permission */
589 masked = ~lo_avd.allowed & avd->allowed;
590 }
591
592 if (source->bounds && target->bounds) {
593 memset(&lo_avd, 0, sizeof(lo_avd));
594 /*
595 * lo_scontext and lo_tcontext are already
596 * set up.
597 */
598
599 context_struct_compute_av(&lo_scontext,
600 &lo_tcontext,
601 tclass,
602 &lo_avd,
603 NULL);
604 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
605 return; /* no masked permission */
606 masked = ~lo_avd.allowed & avd->allowed;
607 }
608
609 if (masked) {
610 /* mask violated permissions */
611 avd->allowed &= ~masked;
612
613 /* audit masked permissions */
614 security_dump_masked_av(scontext, tcontext,
615 tclass, masked, "bounds");
616 }
617 }
618
619 /*
620 * flag which drivers have permissions
621 * only looking for ioctl based extended permssions
622 */
623 void services_compute_xperms_drivers(
624 struct extended_perms *xperms,
625 struct avtab_node *node)
626 {
627 unsigned int i;
628
629 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
630 /* if one or more driver has all permissions allowed */
631 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
632 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
633 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
634 /* if allowing permissions within a driver */
635 security_xperm_set(xperms->drivers.p,
636 node->datum.u.xperms->driver);
637 }
638
639 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
640 if (node->key.specified & AVTAB_XPERMS_ALLOWED)
641 xperms->len = 1;
642 }
643
644 /*
645 * Compute access vectors and extended permissions based on a context
646 * structure pair for the permissions in a particular class.
647 */
648 static void context_struct_compute_av(struct context *scontext,
649 struct context *tcontext,
650 u16 tclass,
651 struct av_decision *avd,
652 struct extended_perms *xperms)
653 {
654 struct constraint_node *constraint;
655 struct role_allow *ra;
656 struct avtab_key avkey;
657 struct avtab_node *node;
658 struct class_datum *tclass_datum;
659 struct ebitmap *sattr, *tattr;
660 struct ebitmap_node *snode, *tnode;
661 unsigned int i, j;
662
663 avd->allowed = 0;
664 avd->auditallow = 0;
665 avd->auditdeny = 0xffffffff;
666 if (xperms) {
667 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
668 xperms->len = 0;
669 }
670
671 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
672 if (printk_ratelimit())
673 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
674 return;
675 }
676
677 tclass_datum = policydb.class_val_to_struct[tclass - 1];
678
679 /*
680 * If a specific type enforcement rule was defined for
681 * this permission check, then use it.
682 */
683 avkey.target_class = tclass;
684 avkey.specified = AVTAB_AV | AVTAB_XPERMS;
685 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
686 BUG_ON(!sattr);
687 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
688 BUG_ON(!tattr);
689 ebitmap_for_each_positive_bit(sattr, snode, i) {
690 ebitmap_for_each_positive_bit(tattr, tnode, j) {
691 avkey.source_type = i + 1;
692 avkey.target_type = j + 1;
693 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
694 node;
695 node = avtab_search_node_next(node, avkey.specified)) {
696 if (node->key.specified == AVTAB_ALLOWED)
697 avd->allowed |= node->datum.u.data;
698 else if (node->key.specified == AVTAB_AUDITALLOW)
699 avd->auditallow |= node->datum.u.data;
700 else if (node->key.specified == AVTAB_AUDITDENY)
701 avd->auditdeny &= node->datum.u.data;
702 else if (xperms && (node->key.specified & AVTAB_XPERMS))
703 services_compute_xperms_drivers(xperms, node);
704 }
705
706 /* Check conditional av table for additional permissions */
707 cond_compute_av(&policydb.te_cond_avtab, &avkey,
708 avd, xperms);
709
710 }
711 }
712
713 /*
714 * Remove any permissions prohibited by a constraint (this includes
715 * the MLS policy).
716 */
717 constraint = tclass_datum->constraints;
718 while (constraint) {
719 if ((constraint->permissions & (avd->allowed)) &&
720 !constraint_expr_eval(scontext, tcontext, NULL,
721 constraint->expr)) {
722 avd->allowed &= ~(constraint->permissions);
723 }
724 constraint = constraint->next;
725 }
726
727 /*
728 * If checking process transition permission and the
729 * role is changing, then check the (current_role, new_role)
730 * pair.
731 */
732 if (tclass == policydb.process_class &&
733 (avd->allowed & policydb.process_trans_perms) &&
734 scontext->role != tcontext->role) {
735 for (ra = policydb.role_allow; ra; ra = ra->next) {
736 if (scontext->role == ra->role &&
737 tcontext->role == ra->new_role)
738 break;
739 }
740 if (!ra)
741 avd->allowed &= ~policydb.process_trans_perms;
742 }
743
744 /*
745 * If the given source and target types have boundary
746 * constraint, lazy checks have to mask any violated
747 * permission and notice it to userspace via audit.
748 */
749 type_attribute_bounds_av(scontext, tcontext,
750 tclass, avd);
751 }
752
753 static int security_validtrans_handle_fail(struct context *ocontext,
754 struct context *ncontext,
755 struct context *tcontext,
756 u16 tclass)
757 {
758 char *o = NULL, *n = NULL, *t = NULL;
759 u32 olen, nlen, tlen;
760
761 if (context_struct_to_string(ocontext, &o, &olen))
762 goto out;
763 if (context_struct_to_string(ncontext, &n, &nlen))
764 goto out;
765 if (context_struct_to_string(tcontext, &t, &tlen))
766 goto out;
767 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
768 "op=security_validate_transition seresult=denied"
769 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
770 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
771 out:
772 kfree(o);
773 kfree(n);
774 kfree(t);
775
776 if (!selinux_enforcing)
777 return 0;
778 return -EPERM;
779 }
780
781 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
782 u16 orig_tclass)
783 {
784 struct context *ocontext;
785 struct context *ncontext;
786 struct context *tcontext;
787 struct class_datum *tclass_datum;
788 struct constraint_node *constraint;
789 u16 tclass;
790 int rc = 0;
791
792 if (!ss_initialized)
793 return 0;
794
795 read_lock(&policy_rwlock);
796
797 tclass = unmap_class(orig_tclass);
798
799 if (!tclass || tclass > policydb.p_classes.nprim) {
800 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
801 __func__, tclass);
802 rc = -EINVAL;
803 goto out;
804 }
805 tclass_datum = policydb.class_val_to_struct[tclass - 1];
806
807 ocontext = sidtab_search(&sidtab, oldsid);
808 if (!ocontext) {
809 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
810 __func__, oldsid);
811 rc = -EINVAL;
812 goto out;
813 }
814
815 ncontext = sidtab_search(&sidtab, newsid);
816 if (!ncontext) {
817 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
818 __func__, newsid);
819 rc = -EINVAL;
820 goto out;
821 }
822
823 tcontext = sidtab_search(&sidtab, tasksid);
824 if (!tcontext) {
825 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
826 __func__, tasksid);
827 rc = -EINVAL;
828 goto out;
829 }
830
831 constraint = tclass_datum->validatetrans;
832 while (constraint) {
833 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
834 constraint->expr)) {
835 rc = security_validtrans_handle_fail(ocontext, ncontext,
836 tcontext, tclass);
837 goto out;
838 }
839 constraint = constraint->next;
840 }
841
842 out:
843 read_unlock(&policy_rwlock);
844 return rc;
845 }
846
847 /*
848 * security_bounded_transition - check whether the given
849 * transition is directed to bounded, or not.
850 * It returns 0, if @newsid is bounded by @oldsid.
851 * Otherwise, it returns error code.
852 *
853 * @oldsid : current security identifier
854 * @newsid : destinated security identifier
855 */
856 int security_bounded_transition(u32 old_sid, u32 new_sid)
857 {
858 struct context *old_context, *new_context;
859 struct type_datum *type;
860 int index;
861 int rc;
862
863 read_lock(&policy_rwlock);
864
865 rc = -EINVAL;
866 old_context = sidtab_search(&sidtab, old_sid);
867 if (!old_context) {
868 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
869 __func__, old_sid);
870 goto out;
871 }
872
873 rc = -EINVAL;
874 new_context = sidtab_search(&sidtab, new_sid);
875 if (!new_context) {
876 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
877 __func__, new_sid);
878 goto out;
879 }
880
881 rc = 0;
882 /* type/domain unchanged */
883 if (old_context->type == new_context->type)
884 goto out;
885
886 index = new_context->type;
887 while (true) {
888 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
889 index - 1);
890 BUG_ON(!type);
891
892 /* not bounded anymore */
893 rc = -EPERM;
894 if (!type->bounds)
895 break;
896
897 /* @newsid is bounded by @oldsid */
898 rc = 0;
899 if (type->bounds == old_context->type)
900 break;
901
902 index = type->bounds;
903 }
904
905 if (rc) {
906 char *old_name = NULL;
907 char *new_name = NULL;
908 u32 length;
909
910 if (!context_struct_to_string(old_context,
911 &old_name, &length) &&
912 !context_struct_to_string(new_context,
913 &new_name, &length)) {
914 audit_log(current->audit_context,
915 GFP_ATOMIC, AUDIT_SELINUX_ERR,
916 "op=security_bounded_transition "
917 "seresult=denied "
918 "oldcontext=%s newcontext=%s",
919 old_name, new_name);
920 }
921 kfree(new_name);
922 kfree(old_name);
923 }
924 out:
925 read_unlock(&policy_rwlock);
926
927 return rc;
928 }
929
930 static void avd_init(struct av_decision *avd)
931 {
932 avd->allowed = 0;
933 avd->auditallow = 0;
934 avd->auditdeny = 0xffffffff;
935 avd->seqno = latest_granting;
936 avd->flags = 0;
937 }
938
939 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
940 struct avtab_node *node)
941 {
942 unsigned int i;
943
944 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
945 if (xpermd->driver != node->datum.u.xperms->driver)
946 return;
947 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
948 if (!security_xperm_test(node->datum.u.xperms->perms.p,
949 xpermd->driver))
950 return;
951 } else {
952 BUG();
953 }
954
955 if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
956 xpermd->used |= XPERMS_ALLOWED;
957 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
958 memset(xpermd->allowed->p, 0xff,
959 sizeof(xpermd->allowed->p));
960 }
961 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
962 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
963 xpermd->allowed->p[i] |=
964 node->datum.u.xperms->perms.p[i];
965 }
966 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
967 xpermd->used |= XPERMS_AUDITALLOW;
968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
969 memset(xpermd->auditallow->p, 0xff,
970 sizeof(xpermd->auditallow->p));
971 }
972 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
973 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
974 xpermd->auditallow->p[i] |=
975 node->datum.u.xperms->perms.p[i];
976 }
977 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
978 xpermd->used |= XPERMS_DONTAUDIT;
979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
980 memset(xpermd->dontaudit->p, 0xff,
981 sizeof(xpermd->dontaudit->p));
982 }
983 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
984 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
985 xpermd->dontaudit->p[i] |=
986 node->datum.u.xperms->perms.p[i];
987 }
988 } else {
989 BUG();
990 }
991 }
992
993 void security_compute_xperms_decision(u32 ssid,
994 u32 tsid,
995 u16 orig_tclass,
996 u8 driver,
997 struct extended_perms_decision *xpermd)
998 {
999 u16 tclass;
1000 struct context *scontext, *tcontext;
1001 struct avtab_key avkey;
1002 struct avtab_node *node;
1003 struct ebitmap *sattr, *tattr;
1004 struct ebitmap_node *snode, *tnode;
1005 unsigned int i, j;
1006
1007 xpermd->driver = driver;
1008 xpermd->used = 0;
1009 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1010 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1011 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1012
1013 read_lock(&policy_rwlock);
1014 if (!ss_initialized)
1015 goto allow;
1016
1017 scontext = sidtab_search(&sidtab, ssid);
1018 if (!scontext) {
1019 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1020 __func__, ssid);
1021 goto out;
1022 }
1023
1024 tcontext = sidtab_search(&sidtab, tsid);
1025 if (!tcontext) {
1026 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1027 __func__, tsid);
1028 goto out;
1029 }
1030
1031 tclass = unmap_class(orig_tclass);
1032 if (unlikely(orig_tclass && !tclass)) {
1033 if (policydb.allow_unknown)
1034 goto allow;
1035 goto out;
1036 }
1037
1038
1039 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1040 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass);
1041 goto out;
1042 }
1043
1044 avkey.target_class = tclass;
1045 avkey.specified = AVTAB_XPERMS;
1046 sattr = flex_array_get(policydb.type_attr_map_array,
1047 scontext->type - 1);
1048 BUG_ON(!sattr);
1049 tattr = flex_array_get(policydb.type_attr_map_array,
1050 tcontext->type - 1);
1051 BUG_ON(!tattr);
1052 ebitmap_for_each_positive_bit(sattr, snode, i) {
1053 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1054 avkey.source_type = i + 1;
1055 avkey.target_type = j + 1;
1056 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1057 node;
1058 node = avtab_search_node_next(node, avkey.specified))
1059 services_compute_xperms_decision(xpermd, node);
1060
1061 cond_compute_xperms(&policydb.te_cond_avtab,
1062 &avkey, xpermd);
1063 }
1064 }
1065 out:
1066 read_unlock(&policy_rwlock);
1067 return;
1068 allow:
1069 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1070 goto out;
1071 }
1072
1073 /**
1074 * security_compute_av - Compute access vector decisions.
1075 * @ssid: source security identifier
1076 * @tsid: target security identifier
1077 * @tclass: target security class
1078 * @avd: access vector decisions
1079 * @xperms: extended permissions
1080 *
1081 * Compute a set of access vector decisions based on the
1082 * SID pair (@ssid, @tsid) for the permissions in @tclass.
1083 */
1084 void security_compute_av(u32 ssid,
1085 u32 tsid,
1086 u16 orig_tclass,
1087 struct av_decision *avd,
1088 struct extended_perms *xperms)
1089 {
1090 u16 tclass;
1091 struct context *scontext = NULL, *tcontext = NULL;
1092
1093 read_lock(&policy_rwlock);
1094 avd_init(avd);
1095 xperms->len = 0;
1096 if (!ss_initialized)
1097 goto allow;
1098
1099 scontext = sidtab_search(&sidtab, ssid);
1100 if (!scontext) {
1101 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1102 __func__, ssid);
1103 goto out;
1104 }
1105
1106 /* permissive domain? */
1107 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1108 avd->flags |= AVD_FLAGS_PERMISSIVE;
1109
1110 tcontext = sidtab_search(&sidtab, tsid);
1111 if (!tcontext) {
1112 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1113 __func__, tsid);
1114 goto out;
1115 }
1116
1117 tclass = unmap_class(orig_tclass);
1118 if (unlikely(orig_tclass && !tclass)) {
1119 if (policydb.allow_unknown)
1120 goto allow;
1121 goto out;
1122 }
1123 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1124 map_decision(orig_tclass, avd, policydb.allow_unknown);
1125 out:
1126 read_unlock(&policy_rwlock);
1127 return;
1128 allow:
1129 avd->allowed = 0xffffffff;
1130 goto out;
1131 }
1132
1133 void security_compute_av_user(u32 ssid,
1134 u32 tsid,
1135 u16 tclass,
1136 struct av_decision *avd)
1137 {
1138 struct context *scontext = NULL, *tcontext = NULL;
1139
1140 read_lock(&policy_rwlock);
1141 avd_init(avd);
1142 if (!ss_initialized)
1143 goto allow;
1144
1145 scontext = sidtab_search(&sidtab, ssid);
1146 if (!scontext) {
1147 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1148 __func__, ssid);
1149 goto out;
1150 }
1151
1152 /* permissive domain? */
1153 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1154 avd->flags |= AVD_FLAGS_PERMISSIVE;
1155
1156 tcontext = sidtab_search(&sidtab, tsid);
1157 if (!tcontext) {
1158 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1159 __func__, tsid);
1160 goto out;
1161 }
1162
1163 if (unlikely(!tclass)) {
1164 if (policydb.allow_unknown)
1165 goto allow;
1166 goto out;
1167 }
1168
1169 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1170 out:
1171 read_unlock(&policy_rwlock);
1172 return;
1173 allow:
1174 avd->allowed = 0xffffffff;
1175 goto out;
1176 }
1177
1178 /*
1179 * Write the security context string representation of
1180 * the context structure `context' into a dynamically
1181 * allocated string of the correct size. Set `*scontext'
1182 * to point to this string and set `*scontext_len' to
1183 * the length of the string.
1184 */
1185 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1186 {
1187 char *scontextp;
1188
1189 if (scontext)
1190 *scontext = NULL;
1191 *scontext_len = 0;
1192
1193 if (context->len) {
1194 *scontext_len = context->len;
1195 if (scontext) {
1196 *scontext = kstrdup(context->str, GFP_ATOMIC);
1197 if (!(*scontext))
1198 return -ENOMEM;
1199 }
1200 return 0;
1201 }
1202
1203 /* Compute the size of the context. */
1204 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1205 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1206 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1207 *scontext_len += mls_compute_context_len(context);
1208
1209 if (!scontext)
1210 return 0;
1211
1212 /* Allocate space for the context; caller must free this space. */
1213 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1214 if (!scontextp)
1215 return -ENOMEM;
1216 *scontext = scontextp;
1217
1218 /*
1219 * Copy the user name, role name and type name into the context.
1220 */
1221 scontextp += sprintf(scontextp, "%s:%s:%s",
1222 sym_name(&policydb, SYM_USERS, context->user - 1),
1223 sym_name(&policydb, SYM_ROLES, context->role - 1),
1224 sym_name(&policydb, SYM_TYPES, context->type - 1));
1225
1226 mls_sid_to_context(context, &scontextp);
1227
1228 *scontextp = 0;
1229
1230 return 0;
1231 }
1232
1233 #include "initial_sid_to_string.h"
1234
1235 const char *security_get_initial_sid_context(u32 sid)
1236 {
1237 if (unlikely(sid > SECINITSID_NUM))
1238 return NULL;
1239 return initial_sid_to_string[sid];
1240 }
1241
1242 static int security_sid_to_context_core(u32 sid, char **scontext,
1243 u32 *scontext_len, int force)
1244 {
1245 struct context *context;
1246 int rc = 0;
1247
1248 if (scontext)
1249 *scontext = NULL;
1250 *scontext_len = 0;
1251
1252 if (!ss_initialized) {
1253 if (sid <= SECINITSID_NUM) {
1254 char *scontextp;
1255
1256 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1257 if (!scontext)
1258 goto out;
1259 scontextp = kmemdup(initial_sid_to_string[sid],
1260 *scontext_len, GFP_ATOMIC);
1261 if (!scontextp) {
1262 rc = -ENOMEM;
1263 goto out;
1264 }
1265 *scontext = scontextp;
1266 goto out;
1267 }
1268 printk(KERN_ERR "SELinux: %s: called before initial "
1269 "load_policy on unknown SID %d\n", __func__, sid);
1270 rc = -EINVAL;
1271 goto out;
1272 }
1273 read_lock(&policy_rwlock);
1274 if (force)
1275 context = sidtab_search_force(&sidtab, sid);
1276 else
1277 context = sidtab_search(&sidtab, sid);
1278 if (!context) {
1279 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1280 __func__, sid);
1281 rc = -EINVAL;
1282 goto out_unlock;
1283 }
1284 rc = context_struct_to_string(context, scontext, scontext_len);
1285 out_unlock:
1286 read_unlock(&policy_rwlock);
1287 out:
1288 return rc;
1289
1290 }
1291
1292 /**
1293 * security_sid_to_context - Obtain a context for a given SID.
1294 * @sid: security identifier, SID
1295 * @scontext: security context
1296 * @scontext_len: length in bytes
1297 *
1298 * Write the string representation of the context associated with @sid
1299 * into a dynamically allocated string of the correct size. Set @scontext
1300 * to point to this string and set @scontext_len to the length of the string.
1301 */
1302 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1303 {
1304 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1305 }
1306
1307 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1308 {
1309 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1310 }
1311
1312 /*
1313 * Caveat: Mutates scontext.
1314 */
1315 static int string_to_context_struct(struct policydb *pol,
1316 struct sidtab *sidtabp,
1317 char *scontext,
1318 u32 scontext_len,
1319 struct context *ctx,
1320 u32 def_sid)
1321 {
1322 struct role_datum *role;
1323 struct type_datum *typdatum;
1324 struct user_datum *usrdatum;
1325 char *scontextp, *p, oldc;
1326 int rc = 0;
1327
1328 context_init(ctx);
1329
1330 /* Parse the security context. */
1331
1332 rc = -EINVAL;
1333 scontextp = (char *) scontext;
1334
1335 /* Extract the user. */
1336 p = scontextp;
1337 while (*p && *p != ':')
1338 p++;
1339
1340 if (*p == 0)
1341 goto out;
1342
1343 *p++ = 0;
1344
1345 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1346 if (!usrdatum)
1347 goto out;
1348
1349 ctx->user = usrdatum->value;
1350
1351 /* Extract role. */
1352 scontextp = p;
1353 while (*p && *p != ':')
1354 p++;
1355
1356 if (*p == 0)
1357 goto out;
1358
1359 *p++ = 0;
1360
1361 role = hashtab_search(pol->p_roles.table, scontextp);
1362 if (!role)
1363 goto out;
1364 ctx->role = role->value;
1365
1366 /* Extract type. */
1367 scontextp = p;
1368 while (*p && *p != ':')
1369 p++;
1370 oldc = *p;
1371 *p++ = 0;
1372
1373 typdatum = hashtab_search(pol->p_types.table, scontextp);
1374 if (!typdatum || typdatum->attribute)
1375 goto out;
1376
1377 ctx->type = typdatum->value;
1378
1379 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1380 if (rc)
1381 goto out;
1382
1383 rc = -EINVAL;
1384 if ((p - scontext) < scontext_len)
1385 goto out;
1386
1387 /* Check the validity of the new context. */
1388 if (!policydb_context_isvalid(pol, ctx))
1389 goto out;
1390 rc = 0;
1391 out:
1392 if (rc)
1393 context_destroy(ctx);
1394 return rc;
1395 }
1396
1397 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1398 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1399 int force)
1400 {
1401 char *scontext2, *str = NULL;
1402 struct context context;
1403 int rc = 0;
1404
1405 /* An empty security context is never valid. */
1406 if (!scontext_len)
1407 return -EINVAL;
1408
1409 if (!ss_initialized) {
1410 int i;
1411
1412 for (i = 1; i < SECINITSID_NUM; i++) {
1413 if (!strcmp(initial_sid_to_string[i], scontext)) {
1414 *sid = i;
1415 return 0;
1416 }
1417 }
1418 *sid = SECINITSID_KERNEL;
1419 return 0;
1420 }
1421 *sid = SECSID_NULL;
1422
1423 /* Copy the string so that we can modify the copy as we parse it. */
1424 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1425 if (!scontext2)
1426 return -ENOMEM;
1427 memcpy(scontext2, scontext, scontext_len);
1428 scontext2[scontext_len] = 0;
1429
1430 if (force) {
1431 /* Save another copy for storing in uninterpreted form */
1432 rc = -ENOMEM;
1433 str = kstrdup(scontext2, gfp_flags);
1434 if (!str)
1435 goto out;
1436 }
1437
1438 read_lock(&policy_rwlock);
1439 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1440 scontext_len, &context, def_sid);
1441 if (rc == -EINVAL && force) {
1442 context.str = str;
1443 context.len = scontext_len;
1444 str = NULL;
1445 } else if (rc)
1446 goto out_unlock;
1447 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1448 context_destroy(&context);
1449 out_unlock:
1450 read_unlock(&policy_rwlock);
1451 out:
1452 kfree(scontext2);
1453 kfree(str);
1454 return rc;
1455 }
1456
1457 /**
1458 * security_context_to_sid - Obtain a SID for a given security context.
1459 * @scontext: security context
1460 * @scontext_len: length in bytes
1461 * @sid: security identifier, SID
1462 * @gfp: context for the allocation
1463 *
1464 * Obtains a SID associated with the security context that
1465 * has the string representation specified by @scontext.
1466 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1467 * memory is available, or 0 on success.
1468 */
1469 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1470 gfp_t gfp)
1471 {
1472 return security_context_to_sid_core(scontext, scontext_len,
1473 sid, SECSID_NULL, gfp, 0);
1474 }
1475
1476 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1477 {
1478 return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1479 }
1480
1481 /**
1482 * security_context_to_sid_default - Obtain a SID for a given security context,
1483 * falling back to specified default if needed.
1484 *
1485 * @scontext: security context
1486 * @scontext_len: length in bytes
1487 * @sid: security identifier, SID
1488 * @def_sid: default SID to assign on error
1489 *
1490 * Obtains a SID associated with the security context that
1491 * has the string representation specified by @scontext.
1492 * The default SID is passed to the MLS layer to be used to allow
1493 * kernel labeling of the MLS field if the MLS field is not present
1494 * (for upgrading to MLS without full relabel).
1495 * Implicitly forces adding of the context even if it cannot be mapped yet.
1496 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1497 * memory is available, or 0 on success.
1498 */
1499 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1500 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1501 {
1502 return security_context_to_sid_core(scontext, scontext_len,
1503 sid, def_sid, gfp_flags, 1);
1504 }
1505
1506 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1507 u32 *sid)
1508 {
1509 return security_context_to_sid_core(scontext, scontext_len,
1510 sid, SECSID_NULL, GFP_KERNEL, 1);
1511 }
1512
1513 static int compute_sid_handle_invalid_context(
1514 struct context *scontext,
1515 struct context *tcontext,
1516 u16 tclass,
1517 struct context *newcontext)
1518 {
1519 char *s = NULL, *t = NULL, *n = NULL;
1520 u32 slen, tlen, nlen;
1521
1522 if (context_struct_to_string(scontext, &s, &slen))
1523 goto out;
1524 if (context_struct_to_string(tcontext, &t, &tlen))
1525 goto out;
1526 if (context_struct_to_string(newcontext, &n, &nlen))
1527 goto out;
1528 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1529 "op=security_compute_sid invalid_context=%s"
1530 " scontext=%s"
1531 " tcontext=%s"
1532 " tclass=%s",
1533 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1534 out:
1535 kfree(s);
1536 kfree(t);
1537 kfree(n);
1538 if (!selinux_enforcing)
1539 return 0;
1540 return -EACCES;
1541 }
1542
1543 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1544 u32 stype, u32 ttype, u16 tclass,
1545 const char *objname)
1546 {
1547 struct filename_trans ft;
1548 struct filename_trans_datum *otype;
1549
1550 /*
1551 * Most filename trans rules are going to live in specific directories
1552 * like /dev or /var/run. This bitmap will quickly skip rule searches
1553 * if the ttype does not contain any rules.
1554 */
1555 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1556 return;
1557
1558 ft.stype = stype;
1559 ft.ttype = ttype;
1560 ft.tclass = tclass;
1561 ft.name = objname;
1562
1563 otype = hashtab_search(p->filename_trans, &ft);
1564 if (otype)
1565 newcontext->type = otype->otype;
1566 }
1567
1568 static int security_compute_sid(u32 ssid,
1569 u32 tsid,
1570 u16 orig_tclass,
1571 u32 specified,
1572 const char *objname,
1573 u32 *out_sid,
1574 bool kern)
1575 {
1576 struct class_datum *cladatum = NULL;
1577 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1578 struct role_trans *roletr = NULL;
1579 struct avtab_key avkey;
1580 struct avtab_datum *avdatum;
1581 struct avtab_node *node;
1582 u16 tclass;
1583 int rc = 0;
1584 bool sock;
1585
1586 if (!ss_initialized) {
1587 switch (orig_tclass) {
1588 case SECCLASS_PROCESS: /* kernel value */
1589 *out_sid = ssid;
1590 break;
1591 default:
1592 *out_sid = tsid;
1593 break;
1594 }
1595 goto out;
1596 }
1597
1598 context_init(&newcontext);
1599
1600 read_lock(&policy_rwlock);
1601
1602 if (kern) {
1603 tclass = unmap_class(orig_tclass);
1604 sock = security_is_socket_class(orig_tclass);
1605 } else {
1606 tclass = orig_tclass;
1607 sock = security_is_socket_class(map_class(tclass));
1608 }
1609
1610 scontext = sidtab_search(&sidtab, ssid);
1611 if (!scontext) {
1612 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1613 __func__, ssid);
1614 rc = -EINVAL;
1615 goto out_unlock;
1616 }
1617 tcontext = sidtab_search(&sidtab, tsid);
1618 if (!tcontext) {
1619 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1620 __func__, tsid);
1621 rc = -EINVAL;
1622 goto out_unlock;
1623 }
1624
1625 if (tclass && tclass <= policydb.p_classes.nprim)
1626 cladatum = policydb.class_val_to_struct[tclass - 1];
1627
1628 /* Set the user identity. */
1629 switch (specified) {
1630 case AVTAB_TRANSITION:
1631 case AVTAB_CHANGE:
1632 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1633 newcontext.user = tcontext->user;
1634 } else {
1635 /* notice this gets both DEFAULT_SOURCE and unset */
1636 /* Use the process user identity. */
1637 newcontext.user = scontext->user;
1638 }
1639 break;
1640 case AVTAB_MEMBER:
1641 /* Use the related object owner. */
1642 newcontext.user = tcontext->user;
1643 break;
1644 }
1645
1646 /* Set the role to default values. */
1647 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1648 newcontext.role = scontext->role;
1649 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1650 newcontext.role = tcontext->role;
1651 } else {
1652 if ((tclass == policydb.process_class) || (sock == true))
1653 newcontext.role = scontext->role;
1654 else
1655 newcontext.role = OBJECT_R_VAL;
1656 }
1657
1658 /* Set the type to default values. */
1659 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1660 newcontext.type = scontext->type;
1661 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1662 newcontext.type = tcontext->type;
1663 } else {
1664 if ((tclass == policydb.process_class) || (sock == true)) {
1665 /* Use the type of process. */
1666 newcontext.type = scontext->type;
1667 } else {
1668 /* Use the type of the related object. */
1669 newcontext.type = tcontext->type;
1670 }
1671 }
1672
1673 /* Look for a type transition/member/change rule. */
1674 avkey.source_type = scontext->type;
1675 avkey.target_type = tcontext->type;
1676 avkey.target_class = tclass;
1677 avkey.specified = specified;
1678 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1679
1680 /* If no permanent rule, also check for enabled conditional rules */
1681 if (!avdatum) {
1682 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1683 for (; node; node = avtab_search_node_next(node, specified)) {
1684 if (node->key.specified & AVTAB_ENABLED) {
1685 avdatum = &node->datum;
1686 break;
1687 }
1688 }
1689 }
1690
1691 if (avdatum) {
1692 /* Use the type from the type transition/member/change rule. */
1693 newcontext.type = avdatum->u.data;
1694 }
1695
1696 /* if we have a objname this is a file trans check so check those rules */
1697 if (objname)
1698 filename_compute_type(&policydb, &newcontext, scontext->type,
1699 tcontext->type, tclass, objname);
1700
1701 /* Check for class-specific changes. */
1702 if (specified & AVTAB_TRANSITION) {
1703 /* Look for a role transition rule. */
1704 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1705 if ((roletr->role == scontext->role) &&
1706 (roletr->type == tcontext->type) &&
1707 (roletr->tclass == tclass)) {
1708 /* Use the role transition rule. */
1709 newcontext.role = roletr->new_role;
1710 break;
1711 }
1712 }
1713 }
1714
1715 /* Set the MLS attributes.
1716 This is done last because it may allocate memory. */
1717 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1718 &newcontext, sock);
1719 if (rc)
1720 goto out_unlock;
1721
1722 /* Check the validity of the context. */
1723 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1724 rc = compute_sid_handle_invalid_context(scontext,
1725 tcontext,
1726 tclass,
1727 &newcontext);
1728 if (rc)
1729 goto out_unlock;
1730 }
1731 /* Obtain the sid for the context. */
1732 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1733 out_unlock:
1734 read_unlock(&policy_rwlock);
1735 context_destroy(&newcontext);
1736 out:
1737 return rc;
1738 }
1739
1740 /**
1741 * security_transition_sid - Compute the SID for a new subject/object.
1742 * @ssid: source security identifier
1743 * @tsid: target security identifier
1744 * @tclass: target security class
1745 * @out_sid: security identifier for new subject/object
1746 *
1747 * Compute a SID to use for labeling a new subject or object in the
1748 * class @tclass based on a SID pair (@ssid, @tsid).
1749 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1750 * if insufficient memory is available, or %0 if the new SID was
1751 * computed successfully.
1752 */
1753 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1754 const struct qstr *qstr, u32 *out_sid)
1755 {
1756 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1757 qstr ? qstr->name : NULL, out_sid, true);
1758 }
1759
1760 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1761 const char *objname, u32 *out_sid)
1762 {
1763 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1764 objname, out_sid, false);
1765 }
1766
1767 /**
1768 * security_member_sid - Compute the SID for member selection.
1769 * @ssid: source security identifier
1770 * @tsid: target security identifier
1771 * @tclass: target security class
1772 * @out_sid: security identifier for selected member
1773 *
1774 * Compute a SID to use when selecting a member of a polyinstantiated
1775 * object of class @tclass based on a SID pair (@ssid, @tsid).
1776 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1777 * if insufficient memory is available, or %0 if the SID was
1778 * computed successfully.
1779 */
1780 int security_member_sid(u32 ssid,
1781 u32 tsid,
1782 u16 tclass,
1783 u32 *out_sid)
1784 {
1785 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1786 out_sid, false);
1787 }
1788
1789 /**
1790 * security_change_sid - Compute the SID for object relabeling.
1791 * @ssid: source security identifier
1792 * @tsid: target security identifier
1793 * @tclass: target security class
1794 * @out_sid: security identifier for selected member
1795 *
1796 * Compute a SID to use for relabeling an object of class @tclass
1797 * based on a SID pair (@ssid, @tsid).
1798 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1799 * if insufficient memory is available, or %0 if the SID was
1800 * computed successfully.
1801 */
1802 int security_change_sid(u32 ssid,
1803 u32 tsid,
1804 u16 tclass,
1805 u32 *out_sid)
1806 {
1807 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1808 out_sid, false);
1809 }
1810
1811 /* Clone the SID into the new SID table. */
1812 static int clone_sid(u32 sid,
1813 struct context *context,
1814 void *arg)
1815 {
1816 struct sidtab *s = arg;
1817
1818 if (sid > SECINITSID_NUM)
1819 return sidtab_insert(s, sid, context);
1820 else
1821 return 0;
1822 }
1823
1824 static inline int convert_context_handle_invalid_context(struct context *context)
1825 {
1826 char *s;
1827 u32 len;
1828
1829 if (selinux_enforcing)
1830 return -EINVAL;
1831
1832 if (!context_struct_to_string(context, &s, &len)) {
1833 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1834 kfree(s);
1835 }
1836 return 0;
1837 }
1838
1839 struct convert_context_args {
1840 struct policydb *oldp;
1841 struct policydb *newp;
1842 };
1843
1844 /*
1845 * Convert the values in the security context
1846 * structure `c' from the values specified
1847 * in the policy `p->oldp' to the values specified
1848 * in the policy `p->newp'. Verify that the
1849 * context is valid under the new policy.
1850 */
1851 static int convert_context(u32 key,
1852 struct context *c,
1853 void *p)
1854 {
1855 struct convert_context_args *args;
1856 struct context oldc;
1857 struct ocontext *oc;
1858 struct mls_range *range;
1859 struct role_datum *role;
1860 struct type_datum *typdatum;
1861 struct user_datum *usrdatum;
1862 char *s;
1863 u32 len;
1864 int rc = 0;
1865
1866 if (key <= SECINITSID_NUM)
1867 goto out;
1868
1869 args = p;
1870
1871 if (c->str) {
1872 struct context ctx;
1873
1874 rc = -ENOMEM;
1875 s = kstrdup(c->str, GFP_KERNEL);
1876 if (!s)
1877 goto out;
1878
1879 rc = string_to_context_struct(args->newp, NULL, s,
1880 c->len, &ctx, SECSID_NULL);
1881 kfree(s);
1882 if (!rc) {
1883 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1884 c->str);
1885 /* Replace string with mapped representation. */
1886 kfree(c->str);
1887 memcpy(c, &ctx, sizeof(*c));
1888 goto out;
1889 } else if (rc == -EINVAL) {
1890 /* Retain string representation for later mapping. */
1891 rc = 0;
1892 goto out;
1893 } else {
1894 /* Other error condition, e.g. ENOMEM. */
1895 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1896 c->str, -rc);
1897 goto out;
1898 }
1899 }
1900
1901 rc = context_cpy(&oldc, c);
1902 if (rc)
1903 goto out;
1904
1905 /* Convert the user. */
1906 rc = -EINVAL;
1907 usrdatum = hashtab_search(args->newp->p_users.table,
1908 sym_name(args->oldp, SYM_USERS, c->user - 1));
1909 if (!usrdatum)
1910 goto bad;
1911 c->user = usrdatum->value;
1912
1913 /* Convert the role. */
1914 rc = -EINVAL;
1915 role = hashtab_search(args->newp->p_roles.table,
1916 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1917 if (!role)
1918 goto bad;
1919 c->role = role->value;
1920
1921 /* Convert the type. */
1922 rc = -EINVAL;
1923 typdatum = hashtab_search(args->newp->p_types.table,
1924 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1925 if (!typdatum)
1926 goto bad;
1927 c->type = typdatum->value;
1928
1929 /* Convert the MLS fields if dealing with MLS policies */
1930 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1931 rc = mls_convert_context(args->oldp, args->newp, c);
1932 if (rc)
1933 goto bad;
1934 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1935 /*
1936 * Switching between MLS and non-MLS policy:
1937 * free any storage used by the MLS fields in the
1938 * context for all existing entries in the sidtab.
1939 */
1940 mls_context_destroy(c);
1941 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1942 /*
1943 * Switching between non-MLS and MLS policy:
1944 * ensure that the MLS fields of the context for all
1945 * existing entries in the sidtab are filled in with a
1946 * suitable default value, likely taken from one of the
1947 * initial SIDs.
1948 */
1949 oc = args->newp->ocontexts[OCON_ISID];
1950 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1951 oc = oc->next;
1952 rc = -EINVAL;
1953 if (!oc) {
1954 printk(KERN_ERR "SELinux: unable to look up"
1955 " the initial SIDs list\n");
1956 goto bad;
1957 }
1958 range = &oc->context[0].range;
1959 rc = mls_range_set(c, range);
1960 if (rc)
1961 goto bad;
1962 }
1963
1964 /* Check the validity of the new context. */
1965 if (!policydb_context_isvalid(args->newp, c)) {
1966 rc = convert_context_handle_invalid_context(&oldc);
1967 if (rc)
1968 goto bad;
1969 }
1970
1971 context_destroy(&oldc);
1972
1973 rc = 0;
1974 out:
1975 return rc;
1976 bad:
1977 /* Map old representation to string and save it. */
1978 rc = context_struct_to_string(&oldc, &s, &len);
1979 if (rc)
1980 return rc;
1981 context_destroy(&oldc);
1982 context_destroy(c);
1983 c->str = s;
1984 c->len = len;
1985 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1986 c->str);
1987 rc = 0;
1988 goto out;
1989 }
1990
1991 static void security_load_policycaps(void)
1992 {
1993 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1994 POLICYDB_CAPABILITY_NETPEER);
1995 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1996 POLICYDB_CAPABILITY_OPENPERM);
1997 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1998 POLICYDB_CAPABILITY_ALWAYSNETWORK);
1999 }
2000
2001 static int security_preserve_bools(struct policydb *p);
2002
2003 /**
2004 * security_load_policy - Load a security policy configuration.
2005 * @data: binary policy data
2006 * @len: length of data in bytes
2007 *
2008 * Load a new set of security policy configuration data,
2009 * validate it and convert the SID table as necessary.
2010 * This function will flush the access vector cache after
2011 * loading the new policy.
2012 */
2013 int security_load_policy(void *data, size_t len)
2014 {
2015 struct policydb *oldpolicydb, *newpolicydb;
2016 struct sidtab oldsidtab, newsidtab;
2017 struct selinux_mapping *oldmap, *map = NULL;
2018 struct convert_context_args args;
2019 u32 seqno;
2020 u16 map_size;
2021 int rc = 0;
2022 struct policy_file file = { data, len }, *fp = &file;
2023
2024 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2025 if (!oldpolicydb) {
2026 rc = -ENOMEM;
2027 goto out;
2028 }
2029 newpolicydb = oldpolicydb + 1;
2030
2031 if (!ss_initialized) {
2032 avtab_cache_init();
2033 rc = policydb_read(&policydb, fp);
2034 if (rc) {
2035 avtab_cache_destroy();
2036 goto out;
2037 }
2038
2039 policydb.len = len;
2040 rc = selinux_set_mapping(&policydb, secclass_map,
2041 &current_mapping,
2042 &current_mapping_size);
2043 if (rc) {
2044 policydb_destroy(&policydb);
2045 avtab_cache_destroy();
2046 goto out;
2047 }
2048
2049 rc = policydb_load_isids(&policydb, &sidtab);
2050 if (rc) {
2051 policydb_destroy(&policydb);
2052 avtab_cache_destroy();
2053 goto out;
2054 }
2055
2056 security_load_policycaps();
2057 ss_initialized = 1;
2058 seqno = ++latest_granting;
2059 selinux_complete_init();
2060 avc_ss_reset(seqno);
2061 selnl_notify_policyload(seqno);
2062 selinux_status_update_policyload(seqno);
2063 selinux_netlbl_cache_invalidate();
2064 selinux_xfrm_notify_policyload();
2065 goto out;
2066 }
2067
2068 #if 0
2069 sidtab_hash_eval(&sidtab, "sids");
2070 #endif
2071
2072 rc = policydb_read(newpolicydb, fp);
2073 if (rc)
2074 goto out;
2075
2076 newpolicydb->len = len;
2077 /* If switching between different policy types, log MLS status */
2078 if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2079 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2080 else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2081 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2082
2083 rc = policydb_load_isids(newpolicydb, &newsidtab);
2084 if (rc) {
2085 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
2086 policydb_destroy(newpolicydb);
2087 goto out;
2088 }
2089
2090 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2091 if (rc)
2092 goto err;
2093
2094 rc = security_preserve_bools(newpolicydb);
2095 if (rc) {
2096 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
2097 goto err;
2098 }
2099
2100 /* Clone the SID table. */
2101 sidtab_shutdown(&sidtab);
2102
2103 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2104 if (rc)
2105 goto err;
2106
2107 /*
2108 * Convert the internal representations of contexts
2109 * in the new SID table.
2110 */
2111 args.oldp = &policydb;
2112 args.newp = newpolicydb;
2113 rc = sidtab_map(&newsidtab, convert_context, &args);
2114 if (rc) {
2115 printk(KERN_ERR "SELinux: unable to convert the internal"
2116 " representation of contexts in the new SID"
2117 " table\n");
2118 goto err;
2119 }
2120
2121 /* Save the old policydb and SID table to free later. */
2122 memcpy(oldpolicydb, &policydb, sizeof(policydb));
2123 sidtab_set(&oldsidtab, &sidtab);
2124
2125 /* Install the new policydb and SID table. */
2126 write_lock_irq(&policy_rwlock);
2127 memcpy(&policydb, newpolicydb, sizeof(policydb));
2128 sidtab_set(&sidtab, &newsidtab);
2129 security_load_policycaps();
2130 oldmap = current_mapping;
2131 current_mapping = map;
2132 current_mapping_size = map_size;
2133 seqno = ++latest_granting;
2134 write_unlock_irq(&policy_rwlock);
2135
2136 /* Free the old policydb and SID table. */
2137 policydb_destroy(oldpolicydb);
2138 sidtab_destroy(&oldsidtab);
2139 kfree(oldmap);
2140
2141 avc_ss_reset(seqno);
2142 selnl_notify_policyload(seqno);
2143 selinux_status_update_policyload(seqno);
2144 selinux_netlbl_cache_invalidate();
2145 selinux_xfrm_notify_policyload();
2146
2147 rc = 0;
2148 goto out;
2149
2150 err:
2151 kfree(map);
2152 sidtab_destroy(&newsidtab);
2153 policydb_destroy(newpolicydb);
2154
2155 out:
2156 kfree(oldpolicydb);
2157 return rc;
2158 }
2159
2160 size_t security_policydb_len(void)
2161 {
2162 size_t len;
2163
2164 read_lock(&policy_rwlock);
2165 len = policydb.len;
2166 read_unlock(&policy_rwlock);
2167
2168 return len;
2169 }
2170
2171 /**
2172 * security_port_sid - Obtain the SID for a port.
2173 * @protocol: protocol number
2174 * @port: port number
2175 * @out_sid: security identifier
2176 */
2177 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2178 {
2179 struct ocontext *c;
2180 int rc = 0;
2181
2182 read_lock(&policy_rwlock);
2183
2184 c = policydb.ocontexts[OCON_PORT];
2185 while (c) {
2186 if (c->u.port.protocol == protocol &&
2187 c->u.port.low_port <= port &&
2188 c->u.port.high_port >= port)
2189 break;
2190 c = c->next;
2191 }
2192
2193 if (c) {
2194 if (!c->sid[0]) {
2195 rc = sidtab_context_to_sid(&sidtab,
2196 &c->context[0],
2197 &c->sid[0]);
2198 if (rc)
2199 goto out;
2200 }
2201 *out_sid = c->sid[0];
2202 } else {
2203 *out_sid = SECINITSID_PORT;
2204 }
2205
2206 out:
2207 read_unlock(&policy_rwlock);
2208 return rc;
2209 }
2210
2211 /**
2212 * security_netif_sid - Obtain the SID for a network interface.
2213 * @name: interface name
2214 * @if_sid: interface SID
2215 */
2216 int security_netif_sid(char *name, u32 *if_sid)
2217 {
2218 int rc = 0;
2219 struct ocontext *c;
2220
2221 read_lock(&policy_rwlock);
2222
2223 c = policydb.ocontexts[OCON_NETIF];
2224 while (c) {
2225 if (strcmp(name, c->u.name) == 0)
2226 break;
2227 c = c->next;
2228 }
2229
2230 if (c) {
2231 if (!c->sid[0] || !c->sid[1]) {
2232 rc = sidtab_context_to_sid(&sidtab,
2233 &c->context[0],
2234 &c->sid[0]);
2235 if (rc)
2236 goto out;
2237 rc = sidtab_context_to_sid(&sidtab,
2238 &c->context[1],
2239 &c->sid[1]);
2240 if (rc)
2241 goto out;
2242 }
2243 *if_sid = c->sid[0];
2244 } else
2245 *if_sid = SECINITSID_NETIF;
2246
2247 out:
2248 read_unlock(&policy_rwlock);
2249 return rc;
2250 }
2251
2252 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2253 {
2254 int i, fail = 0;
2255
2256 for (i = 0; i < 4; i++)
2257 if (addr[i] != (input[i] & mask[i])) {
2258 fail = 1;
2259 break;
2260 }
2261
2262 return !fail;
2263 }
2264
2265 /**
2266 * security_node_sid - Obtain the SID for a node (host).
2267 * @domain: communication domain aka address family
2268 * @addrp: address
2269 * @addrlen: address length in bytes
2270 * @out_sid: security identifier
2271 */
2272 int security_node_sid(u16 domain,
2273 void *addrp,
2274 u32 addrlen,
2275 u32 *out_sid)
2276 {
2277 int rc;
2278 struct ocontext *c;
2279
2280 read_lock(&policy_rwlock);
2281
2282 switch (domain) {
2283 case AF_INET: {
2284 u32 addr;
2285
2286 rc = -EINVAL;
2287 if (addrlen != sizeof(u32))
2288 goto out;
2289
2290 addr = *((u32 *)addrp);
2291
2292 c = policydb.ocontexts[OCON_NODE];
2293 while (c) {
2294 if (c->u.node.addr == (addr & c->u.node.mask))
2295 break;
2296 c = c->next;
2297 }
2298 break;
2299 }
2300
2301 case AF_INET6:
2302 rc = -EINVAL;
2303 if (addrlen != sizeof(u64) * 2)
2304 goto out;
2305 c = policydb.ocontexts[OCON_NODE6];
2306 while (c) {
2307 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2308 c->u.node6.mask))
2309 break;
2310 c = c->next;
2311 }
2312 break;
2313
2314 default:
2315 rc = 0;
2316 *out_sid = SECINITSID_NODE;
2317 goto out;
2318 }
2319
2320 if (c) {
2321 if (!c->sid[0]) {
2322 rc = sidtab_context_to_sid(&sidtab,
2323 &c->context[0],
2324 &c->sid[0]);
2325 if (rc)
2326 goto out;
2327 }
2328 *out_sid = c->sid[0];
2329 } else {
2330 *out_sid = SECINITSID_NODE;
2331 }
2332
2333 rc = 0;
2334 out:
2335 read_unlock(&policy_rwlock);
2336 return rc;
2337 }
2338
2339 #define SIDS_NEL 25
2340
2341 /**
2342 * security_get_user_sids - Obtain reachable SIDs for a user.
2343 * @fromsid: starting SID
2344 * @username: username
2345 * @sids: array of reachable SIDs for user
2346 * @nel: number of elements in @sids
2347 *
2348 * Generate the set of SIDs for legal security contexts
2349 * for a given user that can be reached by @fromsid.
2350 * Set *@sids to point to a dynamically allocated
2351 * array containing the set of SIDs. Set *@nel to the
2352 * number of elements in the array.
2353 */
2354
2355 int security_get_user_sids(u32 fromsid,
2356 char *username,
2357 u32 **sids,
2358 u32 *nel)
2359 {
2360 struct context *fromcon, usercon;
2361 u32 *mysids = NULL, *mysids2, sid;
2362 u32 mynel = 0, maxnel = SIDS_NEL;
2363 struct user_datum *user;
2364 struct role_datum *role;
2365 struct ebitmap_node *rnode, *tnode;
2366 int rc = 0, i, j;
2367
2368 *sids = NULL;
2369 *nel = 0;
2370
2371 if (!ss_initialized)
2372 goto out;
2373
2374 read_lock(&policy_rwlock);
2375
2376 context_init(&usercon);
2377
2378 rc = -EINVAL;
2379 fromcon = sidtab_search(&sidtab, fromsid);
2380 if (!fromcon)
2381 goto out_unlock;
2382
2383 rc = -EINVAL;
2384 user = hashtab_search(policydb.p_users.table, username);
2385 if (!user)
2386 goto out_unlock;
2387
2388 usercon.user = user->value;
2389
2390 rc = -ENOMEM;
2391 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2392 if (!mysids)
2393 goto out_unlock;
2394
2395 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2396 role = policydb.role_val_to_struct[i];
2397 usercon.role = i + 1;
2398 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2399 usercon.type = j + 1;
2400
2401 if (mls_setup_user_range(fromcon, user, &usercon))
2402 continue;
2403
2404 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2405 if (rc)
2406 goto out_unlock;
2407 if (mynel < maxnel) {
2408 mysids[mynel++] = sid;
2409 } else {
2410 rc = -ENOMEM;
2411 maxnel += SIDS_NEL;
2412 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2413 if (!mysids2)
2414 goto out_unlock;
2415 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2416 kfree(mysids);
2417 mysids = mysids2;
2418 mysids[mynel++] = sid;
2419 }
2420 }
2421 }
2422 rc = 0;
2423 out_unlock:
2424 read_unlock(&policy_rwlock);
2425 if (rc || !mynel) {
2426 kfree(mysids);
2427 goto out;
2428 }
2429
2430 rc = -ENOMEM;
2431 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2432 if (!mysids2) {
2433 kfree(mysids);
2434 goto out;
2435 }
2436 for (i = 0, j = 0; i < mynel; i++) {
2437 struct av_decision dummy_avd;
2438 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2439 SECCLASS_PROCESS, /* kernel value */
2440 PROCESS__TRANSITION, AVC_STRICT,
2441 &dummy_avd);
2442 if (!rc)
2443 mysids2[j++] = mysids[i];
2444 cond_resched();
2445 }
2446 rc = 0;
2447 kfree(mysids);
2448 *sids = mysids2;
2449 *nel = j;
2450 out:
2451 return rc;
2452 }
2453
2454 /**
2455 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2456 * @fstype: filesystem type
2457 * @path: path from root of mount
2458 * @sclass: file security class
2459 * @sid: SID for path
2460 *
2461 * Obtain a SID to use for a file in a filesystem that
2462 * cannot support xattr or use a fixed labeling behavior like
2463 * transition SIDs or task SIDs.
2464 *
2465 * The caller must acquire the policy_rwlock before calling this function.
2466 */
2467 static inline int __security_genfs_sid(const char *fstype,
2468 char *path,
2469 u16 orig_sclass,
2470 u32 *sid)
2471 {
2472 int len;
2473 u16 sclass;
2474 struct genfs *genfs;
2475 struct ocontext *c;
2476 int rc, cmp = 0;
2477
2478 while (path[0] == '/' && path[1] == '/')
2479 path++;
2480
2481 sclass = unmap_class(orig_sclass);
2482 *sid = SECINITSID_UNLABELED;
2483
2484 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2485 cmp = strcmp(fstype, genfs->fstype);
2486 if (cmp <= 0)
2487 break;
2488 }
2489
2490 rc = -ENOENT;
2491 if (!genfs || cmp)
2492 goto out;
2493
2494 for (c = genfs->head; c; c = c->next) {
2495 len = strlen(c->u.name);
2496 if ((!c->v.sclass || sclass == c->v.sclass) &&
2497 (strncmp(c->u.name, path, len) == 0))
2498 break;
2499 }
2500
2501 rc = -ENOENT;
2502 if (!c)
2503 goto out;
2504
2505 if (!c->sid[0]) {
2506 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2507 if (rc)
2508 goto out;
2509 }
2510
2511 *sid = c->sid[0];
2512 rc = 0;
2513 out:
2514 return rc;
2515 }
2516
2517 /**
2518 * security_genfs_sid - Obtain a SID for a file in a filesystem
2519 * @fstype: filesystem type
2520 * @path: path from root of mount
2521 * @sclass: file security class
2522 * @sid: SID for path
2523 *
2524 * Acquire policy_rwlock before calling __security_genfs_sid() and release
2525 * it afterward.
2526 */
2527 int security_genfs_sid(const char *fstype,
2528 char *path,
2529 u16 orig_sclass,
2530 u32 *sid)
2531 {
2532 int retval;
2533
2534 read_lock(&policy_rwlock);
2535 retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2536 read_unlock(&policy_rwlock);
2537 return retval;
2538 }
2539
2540 /**
2541 * security_fs_use - Determine how to handle labeling for a filesystem.
2542 * @sb: superblock in question
2543 */
2544 int security_fs_use(struct super_block *sb)
2545 {
2546 int rc = 0;
2547 struct ocontext *c;
2548 struct superblock_security_struct *sbsec = sb->s_security;
2549 const char *fstype = sb->s_type->name;
2550
2551 read_lock(&policy_rwlock);
2552
2553 c = policydb.ocontexts[OCON_FSUSE];
2554 while (c) {
2555 if (strcmp(fstype, c->u.name) == 0)
2556 break;
2557 c = c->next;
2558 }
2559
2560 if (c) {
2561 sbsec->behavior = c->v.behavior;
2562 if (!c->sid[0]) {
2563 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2564 &c->sid[0]);
2565 if (rc)
2566 goto out;
2567 }
2568 sbsec->sid = c->sid[0];
2569 } else {
2570 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2571 &sbsec->sid);
2572 if (rc) {
2573 sbsec->behavior = SECURITY_FS_USE_NONE;
2574 rc = 0;
2575 } else {
2576 sbsec->behavior = SECURITY_FS_USE_GENFS;
2577 }
2578 }
2579
2580 out:
2581 read_unlock(&policy_rwlock);
2582 return rc;
2583 }
2584
2585 int security_get_bools(int *len, char ***names, int **values)
2586 {
2587 int i, rc;
2588
2589 read_lock(&policy_rwlock);
2590 *names = NULL;
2591 *values = NULL;
2592
2593 rc = 0;
2594 *len = policydb.p_bools.nprim;
2595 if (!*len)
2596 goto out;
2597
2598 rc = -ENOMEM;
2599 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2600 if (!*names)
2601 goto err;
2602
2603 rc = -ENOMEM;
2604 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2605 if (!*values)
2606 goto err;
2607
2608 for (i = 0; i < *len; i++) {
2609 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2610
2611 rc = -ENOMEM;
2612 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2613 if (!(*names)[i])
2614 goto err;
2615 }
2616 rc = 0;
2617 out:
2618 read_unlock(&policy_rwlock);
2619 return rc;
2620 err:
2621 if (*names) {
2622 for (i = 0; i < *len; i++)
2623 kfree((*names)[i]);
2624 }
2625 kfree(*values);
2626 goto out;
2627 }
2628
2629
2630 int security_set_bools(int len, int *values)
2631 {
2632 int i, rc;
2633 int lenp, seqno = 0;
2634 struct cond_node *cur;
2635
2636 write_lock_irq(&policy_rwlock);
2637
2638 rc = -EFAULT;
2639 lenp = policydb.p_bools.nprim;
2640 if (len != lenp)
2641 goto out;
2642
2643 for (i = 0; i < len; i++) {
2644 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2645 audit_log(current->audit_context, GFP_ATOMIC,
2646 AUDIT_MAC_CONFIG_CHANGE,
2647 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2648 sym_name(&policydb, SYM_BOOLS, i),
2649 !!values[i],
2650 policydb.bool_val_to_struct[i]->state,
2651 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2652 audit_get_sessionid(current));
2653 }
2654 if (values[i])
2655 policydb.bool_val_to_struct[i]->state = 1;
2656 else
2657 policydb.bool_val_to_struct[i]->state = 0;
2658 }
2659
2660 for (cur = policydb.cond_list; cur; cur = cur->next) {
2661 rc = evaluate_cond_node(&policydb, cur);
2662 if (rc)
2663 goto out;
2664 }
2665
2666 seqno = ++latest_granting;
2667 rc = 0;
2668 out:
2669 write_unlock_irq(&policy_rwlock);
2670 if (!rc) {
2671 avc_ss_reset(seqno);
2672 selnl_notify_policyload(seqno);
2673 selinux_status_update_policyload(seqno);
2674 selinux_xfrm_notify_policyload();
2675 }
2676 return rc;
2677 }
2678
2679 int security_get_bool_value(int bool)
2680 {
2681 int rc;
2682 int len;
2683
2684 read_lock(&policy_rwlock);
2685
2686 rc = -EFAULT;
2687 len = policydb.p_bools.nprim;
2688 if (bool >= len)
2689 goto out;
2690
2691 rc = policydb.bool_val_to_struct[bool]->state;
2692 out:
2693 read_unlock(&policy_rwlock);
2694 return rc;
2695 }
2696
2697 static int security_preserve_bools(struct policydb *p)
2698 {
2699 int rc, nbools = 0, *bvalues = NULL, i;
2700 char **bnames = NULL;
2701 struct cond_bool_datum *booldatum;
2702 struct cond_node *cur;
2703
2704 rc = security_get_bools(&nbools, &bnames, &bvalues);
2705 if (rc)
2706 goto out;
2707 for (i = 0; i < nbools; i++) {
2708 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2709 if (booldatum)
2710 booldatum->state = bvalues[i];
2711 }
2712 for (cur = p->cond_list; cur; cur = cur->next) {
2713 rc = evaluate_cond_node(p, cur);
2714 if (rc)
2715 goto out;
2716 }
2717
2718 out:
2719 if (bnames) {
2720 for (i = 0; i < nbools; i++)
2721 kfree(bnames[i]);
2722 }
2723 kfree(bnames);
2724 kfree(bvalues);
2725 return rc;
2726 }
2727
2728 /*
2729 * security_sid_mls_copy() - computes a new sid based on the given
2730 * sid and the mls portion of mls_sid.
2731 */
2732 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2733 {
2734 struct context *context1;
2735 struct context *context2;
2736 struct context newcon;
2737 char *s;
2738 u32 len;
2739 int rc;
2740
2741 rc = 0;
2742 if (!ss_initialized || !policydb.mls_enabled) {
2743 *new_sid = sid;
2744 goto out;
2745 }
2746
2747 context_init(&newcon);
2748
2749 read_lock(&policy_rwlock);
2750
2751 rc = -EINVAL;
2752 context1 = sidtab_search(&sidtab, sid);
2753 if (!context1) {
2754 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2755 __func__, sid);
2756 goto out_unlock;
2757 }
2758
2759 rc = -EINVAL;
2760 context2 = sidtab_search(&sidtab, mls_sid);
2761 if (!context2) {
2762 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2763 __func__, mls_sid);
2764 goto out_unlock;
2765 }
2766
2767 newcon.user = context1->user;
2768 newcon.role = context1->role;
2769 newcon.type = context1->type;
2770 rc = mls_context_cpy(&newcon, context2);
2771 if (rc)
2772 goto out_unlock;
2773
2774 /* Check the validity of the new context. */
2775 if (!policydb_context_isvalid(&policydb, &newcon)) {
2776 rc = convert_context_handle_invalid_context(&newcon);
2777 if (rc) {
2778 if (!context_struct_to_string(&newcon, &s, &len)) {
2779 audit_log(current->audit_context,
2780 GFP_ATOMIC, AUDIT_SELINUX_ERR,
2781 "op=security_sid_mls_copy "
2782 "invalid_context=%s", s);
2783 kfree(s);
2784 }
2785 goto out_unlock;
2786 }
2787 }
2788
2789 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2790 out_unlock:
2791 read_unlock(&policy_rwlock);
2792 context_destroy(&newcon);
2793 out:
2794 return rc;
2795 }
2796
2797 /**
2798 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2799 * @nlbl_sid: NetLabel SID
2800 * @nlbl_type: NetLabel labeling protocol type
2801 * @xfrm_sid: XFRM SID
2802 *
2803 * Description:
2804 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2805 * resolved into a single SID it is returned via @peer_sid and the function
2806 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2807 * returns a negative value. A table summarizing the behavior is below:
2808 *
2809 * | function return | @sid
2810 * ------------------------------+-----------------+-----------------
2811 * no peer labels | 0 | SECSID_NULL
2812 * single peer label | 0 | <peer_label>
2813 * multiple, consistent labels | 0 | <peer_label>
2814 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2815 *
2816 */
2817 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2818 u32 xfrm_sid,
2819 u32 *peer_sid)
2820 {
2821 int rc;
2822 struct context *nlbl_ctx;
2823 struct context *xfrm_ctx;
2824
2825 *peer_sid = SECSID_NULL;
2826
2827 /* handle the common (which also happens to be the set of easy) cases
2828 * right away, these two if statements catch everything involving a
2829 * single or absent peer SID/label */
2830 if (xfrm_sid == SECSID_NULL) {
2831 *peer_sid = nlbl_sid;
2832 return 0;
2833 }
2834 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2835 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2836 * is present */
2837 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2838 *peer_sid = xfrm_sid;
2839 return 0;
2840 }
2841
2842 /* we don't need to check ss_initialized here since the only way both
2843 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2844 * security server was initialized and ss_initialized was true */
2845 if (!policydb.mls_enabled)
2846 return 0;
2847
2848 read_lock(&policy_rwlock);
2849
2850 rc = -EINVAL;
2851 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2852 if (!nlbl_ctx) {
2853 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2854 __func__, nlbl_sid);
2855 goto out;
2856 }
2857 rc = -EINVAL;
2858 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2859 if (!xfrm_ctx) {
2860 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2861 __func__, xfrm_sid);
2862 goto out;
2863 }
2864 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2865 if (rc)
2866 goto out;
2867
2868 /* at present NetLabel SIDs/labels really only carry MLS
2869 * information so if the MLS portion of the NetLabel SID
2870 * matches the MLS portion of the labeled XFRM SID/label
2871 * then pass along the XFRM SID as it is the most
2872 * expressive */
2873 *peer_sid = xfrm_sid;
2874 out:
2875 read_unlock(&policy_rwlock);
2876 return rc;
2877 }
2878
2879 static int get_classes_callback(void *k, void *d, void *args)
2880 {
2881 struct class_datum *datum = d;
2882 char *name = k, **classes = args;
2883 int value = datum->value - 1;
2884
2885 classes[value] = kstrdup(name, GFP_ATOMIC);
2886 if (!classes[value])
2887 return -ENOMEM;
2888
2889 return 0;
2890 }
2891
2892 int security_get_classes(char ***classes, int *nclasses)
2893 {
2894 int rc;
2895
2896 read_lock(&policy_rwlock);
2897
2898 rc = -ENOMEM;
2899 *nclasses = policydb.p_classes.nprim;
2900 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2901 if (!*classes)
2902 goto out;
2903
2904 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2905 *classes);
2906 if (rc) {
2907 int i;
2908 for (i = 0; i < *nclasses; i++)
2909 kfree((*classes)[i]);
2910 kfree(*classes);
2911 }
2912
2913 out:
2914 read_unlock(&policy_rwlock);
2915 return rc;
2916 }
2917
2918 static int get_permissions_callback(void *k, void *d, void *args)
2919 {
2920 struct perm_datum *datum = d;
2921 char *name = k, **perms = args;
2922 int value = datum->value - 1;
2923
2924 perms[value] = kstrdup(name, GFP_ATOMIC);
2925 if (!perms[value])
2926 return -ENOMEM;
2927
2928 return 0;
2929 }
2930
2931 int security_get_permissions(char *class, char ***perms, int *nperms)
2932 {
2933 int rc, i;
2934 struct class_datum *match;
2935
2936 read_lock(&policy_rwlock);
2937
2938 rc = -EINVAL;
2939 match = hashtab_search(policydb.p_classes.table, class);
2940 if (!match) {
2941 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2942 __func__, class);
2943 goto out;
2944 }
2945
2946 rc = -ENOMEM;
2947 *nperms = match->permissions.nprim;
2948 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2949 if (!*perms)
2950 goto out;
2951
2952 if (match->comdatum) {
2953 rc = hashtab_map(match->comdatum->permissions.table,
2954 get_permissions_callback, *perms);
2955 if (rc)
2956 goto err;
2957 }
2958
2959 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2960 *perms);
2961 if (rc)
2962 goto err;
2963
2964 out:
2965 read_unlock(&policy_rwlock);
2966 return rc;
2967
2968 err:
2969 read_unlock(&policy_rwlock);
2970 for (i = 0; i < *nperms; i++)
2971 kfree((*perms)[i]);
2972 kfree(*perms);
2973 return rc;
2974 }
2975
2976 int security_get_reject_unknown(void)
2977 {
2978 return policydb.reject_unknown;
2979 }
2980
2981 int security_get_allow_unknown(void)
2982 {
2983 return policydb.allow_unknown;
2984 }
2985
2986 /**
2987 * security_policycap_supported - Check for a specific policy capability
2988 * @req_cap: capability
2989 *
2990 * Description:
2991 * This function queries the currently loaded policy to see if it supports the
2992 * capability specified by @req_cap. Returns true (1) if the capability is
2993 * supported, false (0) if it isn't supported.
2994 *
2995 */
2996 int security_policycap_supported(unsigned int req_cap)
2997 {
2998 int rc;
2999
3000 read_lock(&policy_rwlock);
3001 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3002 read_unlock(&policy_rwlock);
3003
3004 return rc;
3005 }
3006
3007 struct selinux_audit_rule {
3008 u32 au_seqno;
3009 struct context au_ctxt;
3010 };
3011
3012 void selinux_audit_rule_free(void *vrule)
3013 {
3014 struct selinux_audit_rule *rule = vrule;
3015
3016 if (rule) {
3017 context_destroy(&rule->au_ctxt);
3018 kfree(rule);
3019 }
3020 }
3021
3022 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3023 {
3024 struct selinux_audit_rule *tmprule;
3025 struct role_datum *roledatum;
3026 struct type_datum *typedatum;
3027 struct user_datum *userdatum;
3028 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3029 int rc = 0;
3030
3031 *rule = NULL;
3032
3033 if (!ss_initialized)
3034 return -EOPNOTSUPP;
3035
3036 switch (field) {
3037 case AUDIT_SUBJ_USER:
3038 case AUDIT_SUBJ_ROLE:
3039 case AUDIT_SUBJ_TYPE:
3040 case AUDIT_OBJ_USER:
3041 case AUDIT_OBJ_ROLE:
3042 case AUDIT_OBJ_TYPE:
3043 /* only 'equals' and 'not equals' fit user, role, and type */
3044 if (op != Audit_equal && op != Audit_not_equal)
3045 return -EINVAL;
3046 break;
3047 case AUDIT_SUBJ_SEN:
3048 case AUDIT_SUBJ_CLR:
3049 case AUDIT_OBJ_LEV_LOW:
3050 case AUDIT_OBJ_LEV_HIGH:
3051 /* we do not allow a range, indicated by the presence of '-' */
3052 if (strchr(rulestr, '-'))
3053 return -EINVAL;
3054 break;
3055 default:
3056 /* only the above fields are valid */
3057 return -EINVAL;
3058 }
3059
3060 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3061 if (!tmprule)
3062 return -ENOMEM;
3063
3064 context_init(&tmprule->au_ctxt);
3065
3066 read_lock(&policy_rwlock);
3067
3068 tmprule->au_seqno = latest_granting;
3069
3070 switch (field) {
3071 case AUDIT_SUBJ_USER:
3072 case AUDIT_OBJ_USER:
3073 rc = -EINVAL;
3074 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3075 if (!userdatum)
3076 goto out;
3077 tmprule->au_ctxt.user = userdatum->value;
3078 break;
3079 case AUDIT_SUBJ_ROLE:
3080 case AUDIT_OBJ_ROLE:
3081 rc = -EINVAL;
3082 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3083 if (!roledatum)
3084 goto out;
3085 tmprule->au_ctxt.role = roledatum->value;
3086 break;
3087 case AUDIT_SUBJ_TYPE:
3088 case AUDIT_OBJ_TYPE:
3089 rc = -EINVAL;
3090 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3091 if (!typedatum)
3092 goto out;
3093 tmprule->au_ctxt.type = typedatum->value;
3094 break;
3095 case AUDIT_SUBJ_SEN:
3096 case AUDIT_SUBJ_CLR:
3097 case AUDIT_OBJ_LEV_LOW:
3098 case AUDIT_OBJ_LEV_HIGH:
3099 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3100 if (rc)
3101 goto out;
3102 break;
3103 }
3104 rc = 0;
3105 out:
3106 read_unlock(&policy_rwlock);
3107
3108 if (rc) {
3109 selinux_audit_rule_free(tmprule);
3110 tmprule = NULL;
3111 }
3112
3113 *rule = tmprule;
3114
3115 return rc;
3116 }
3117
3118 /* Check to see if the rule contains any selinux fields */
3119 int selinux_audit_rule_known(struct audit_krule *rule)
3120 {
3121 int i;
3122
3123 for (i = 0; i < rule->field_count; i++) {
3124 struct audit_field *f = &rule->fields[i];
3125 switch (f->type) {
3126 case AUDIT_SUBJ_USER:
3127 case AUDIT_SUBJ_ROLE:
3128 case AUDIT_SUBJ_TYPE:
3129 case AUDIT_SUBJ_SEN:
3130 case AUDIT_SUBJ_CLR:
3131 case AUDIT_OBJ_USER:
3132 case AUDIT_OBJ_ROLE:
3133 case AUDIT_OBJ_TYPE:
3134 case AUDIT_OBJ_LEV_LOW:
3135 case AUDIT_OBJ_LEV_HIGH:
3136 return 1;
3137 }
3138 }
3139
3140 return 0;
3141 }
3142
3143 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3144 struct audit_context *actx)
3145 {
3146 struct context *ctxt;
3147 struct mls_level *level;
3148 struct selinux_audit_rule *rule = vrule;
3149 int match = 0;
3150
3151 if (unlikely(!rule)) {
3152 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3153 return -ENOENT;
3154 }
3155
3156 read_lock(&policy_rwlock);
3157
3158 if (rule->au_seqno < latest_granting) {
3159 match = -ESTALE;
3160 goto out;
3161 }
3162
3163 ctxt = sidtab_search(&sidtab, sid);
3164 if (unlikely(!ctxt)) {
3165 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3166 sid);
3167 match = -ENOENT;
3168 goto out;
3169 }
3170
3171 /* a field/op pair that is not caught here will simply fall through
3172 without a match */
3173 switch (field) {
3174 case AUDIT_SUBJ_USER:
3175 case AUDIT_OBJ_USER:
3176 switch (op) {
3177 case Audit_equal:
3178 match = (ctxt->user == rule->au_ctxt.user);
3179 break;
3180 case Audit_not_equal:
3181 match = (ctxt->user != rule->au_ctxt.user);
3182 break;
3183 }
3184 break;
3185 case AUDIT_SUBJ_ROLE:
3186 case AUDIT_OBJ_ROLE:
3187 switch (op) {
3188 case Audit_equal:
3189 match = (ctxt->role == rule->au_ctxt.role);
3190 break;
3191 case Audit_not_equal:
3192 match = (ctxt->role != rule->au_ctxt.role);
3193 break;
3194 }
3195 break;
3196 case AUDIT_SUBJ_TYPE:
3197 case AUDIT_OBJ_TYPE:
3198 switch (op) {
3199 case Audit_equal:
3200 match = (ctxt->type == rule->au_ctxt.type);
3201 break;
3202 case Audit_not_equal:
3203 match = (ctxt->type != rule->au_ctxt.type);
3204 break;
3205 }
3206 break;
3207 case AUDIT_SUBJ_SEN:
3208 case AUDIT_SUBJ_CLR:
3209 case AUDIT_OBJ_LEV_LOW:
3210 case AUDIT_OBJ_LEV_HIGH:
3211 level = ((field == AUDIT_SUBJ_SEN ||
3212 field == AUDIT_OBJ_LEV_LOW) ?
3213 &ctxt->range.level[0] : &ctxt->range.level[1]);
3214 switch (op) {
3215 case Audit_equal:
3216 match = mls_level_eq(&rule->au_ctxt.range.level[0],
3217 level);
3218 break;
3219 case Audit_not_equal:
3220 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3221 level);
3222 break;
3223 case Audit_lt:
3224 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3225 level) &&
3226 !mls_level_eq(&rule->au_ctxt.range.level[0],
3227 level));
3228 break;
3229 case Audit_le:
3230 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3231 level);
3232 break;
3233 case Audit_gt:
3234 match = (mls_level_dom(level,
3235 &rule->au_ctxt.range.level[0]) &&
3236 !mls_level_eq(level,
3237 &rule->au_ctxt.range.level[0]));
3238 break;
3239 case Audit_ge:
3240 match = mls_level_dom(level,
3241 &rule->au_ctxt.range.level[0]);
3242 break;
3243 }
3244 }
3245
3246 out:
3247 read_unlock(&policy_rwlock);
3248 return match;
3249 }
3250
3251 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3252
3253 static int aurule_avc_callback(u32 event)
3254 {
3255 int err = 0;
3256
3257 if (event == AVC_CALLBACK_RESET && aurule_callback)
3258 err = aurule_callback();
3259 return err;
3260 }
3261
3262 static int __init aurule_init(void)
3263 {
3264 int err;
3265
3266 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3267 if (err)
3268 panic("avc_add_callback() failed, error %d\n", err);
3269
3270 return err;
3271 }
3272 __initcall(aurule_init);
3273
3274 #ifdef CONFIG_NETLABEL
3275 /**
3276 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3277 * @secattr: the NetLabel packet security attributes
3278 * @sid: the SELinux SID
3279 *
3280 * Description:
3281 * Attempt to cache the context in @ctx, which was derived from the packet in
3282 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3283 * already been initialized.
3284 *
3285 */
3286 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3287 u32 sid)
3288 {
3289 u32 *sid_cache;
3290
3291 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3292 if (sid_cache == NULL)
3293 return;
3294 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3295 if (secattr->cache == NULL) {
3296 kfree(sid_cache);
3297 return;
3298 }
3299
3300 *sid_cache = sid;
3301 secattr->cache->free = kfree;
3302 secattr->cache->data = sid_cache;
3303 secattr->flags |= NETLBL_SECATTR_CACHE;
3304 }
3305
3306 /**
3307 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3308 * @secattr: the NetLabel packet security attributes
3309 * @sid: the SELinux SID
3310 *
3311 * Description:
3312 * Convert the given NetLabel security attributes in @secattr into a
3313 * SELinux SID. If the @secattr field does not contain a full SELinux
3314 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3315 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3316 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3317 * conversion for future lookups. Returns zero on success, negative values on
3318 * failure.
3319 *
3320 */
3321 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3322 u32 *sid)
3323 {
3324 int rc;
3325 struct context *ctx;
3326 struct context ctx_new;
3327
3328 if (!ss_initialized) {
3329 *sid = SECSID_NULL;
3330 return 0;
3331 }
3332
3333 read_lock(&policy_rwlock);
3334
3335 if (secattr->flags & NETLBL_SECATTR_CACHE)
3336 *sid = *(u32 *)secattr->cache->data;
3337 else if (secattr->flags & NETLBL_SECATTR_SECID)
3338 *sid = secattr->attr.secid;
3339 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3340 rc = -EIDRM;
3341 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3342 if (ctx == NULL)
3343 goto out;
3344
3345 context_init(&ctx_new);
3346 ctx_new.user = ctx->user;
3347 ctx_new.role = ctx->role;
3348 ctx_new.type = ctx->type;
3349 mls_import_netlbl_lvl(&ctx_new, secattr);
3350 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3351 rc = mls_import_netlbl_cat(&ctx_new, secattr);
3352 if (rc)
3353 goto out;
3354 }
3355 rc = -EIDRM;
3356 if (!mls_context_isvalid(&policydb, &ctx_new))
3357 goto out_free;
3358
3359 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3360 if (rc)
3361 goto out_free;
3362
3363 security_netlbl_cache_add(secattr, *sid);
3364
3365 ebitmap_destroy(&ctx_new.range.level[0].cat);
3366 } else
3367 *sid = SECSID_NULL;
3368
3369 read_unlock(&policy_rwlock);
3370 return 0;
3371 out_free:
3372 ebitmap_destroy(&ctx_new.range.level[0].cat);
3373 out:
3374 read_unlock(&policy_rwlock);
3375 return rc;
3376 }
3377
3378 /**
3379 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3380 * @sid: the SELinux SID
3381 * @secattr: the NetLabel packet security attributes
3382 *
3383 * Description:
3384 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3385 * Returns zero on success, negative values on failure.
3386 *
3387 */
3388 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3389 {
3390 int rc;
3391 struct context *ctx;
3392
3393 if (!ss_initialized)
3394 return 0;
3395
3396 read_lock(&policy_rwlock);
3397
3398 rc = -ENOENT;
3399 ctx = sidtab_search(&sidtab, sid);
3400 if (ctx == NULL)
3401 goto out;
3402
3403 rc = -ENOMEM;
3404 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3405 GFP_ATOMIC);
3406 if (secattr->domain == NULL)
3407 goto out;
3408
3409 secattr->attr.secid = sid;
3410 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3411 mls_export_netlbl_lvl(ctx, secattr);
3412 rc = mls_export_netlbl_cat(ctx, secattr);
3413 out:
3414 read_unlock(&policy_rwlock);
3415 return rc;
3416 }
3417 #endif /* CONFIG_NETLABEL */
3418
3419 /**
3420 * security_read_policy - read the policy.
3421 * @data: binary policy data
3422 * @len: length of data in bytes
3423 *
3424 */
3425 int security_read_policy(void **data, size_t *len)
3426 {
3427 int rc;
3428 struct policy_file fp;
3429
3430 if (!ss_initialized)
3431 return -EINVAL;
3432
3433 *len = security_policydb_len();
3434
3435 *data = vmalloc_user(*len);
3436 if (!*data)
3437 return -ENOMEM;
3438
3439 fp.data = *data;
3440 fp.len = *len;
3441
3442 read_lock(&policy_rwlock);
3443 rc = policydb_write(&policydb, &fp);
3444 read_unlock(&policy_rwlock);
3445
3446 if (rc)
3447 return rc;
3448
3449 *len = (unsigned long)fp.data - (unsigned long)*data;
3450 return 0;
3451
3452 }
Linux with added FPC-III support