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