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[mirror_ubuntu-bionic-kernel.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 extern void selnl_notify_policyload(u32 seqno);
74
75 int selinux_policycap_netpeer;
76 int selinux_policycap_openperm;
77
78 static DEFINE_RWLOCK(policy_rwlock);
79
80 static struct sidtab sidtab;
81 struct policydb policydb;
82 int ss_initialized;
83
84 /*
85 * The largest sequence number that has been used when
86 * providing an access decision to the access vector cache.
87 * The sequence number only changes when a policy change
88 * occurs.
89 */
90 static u32 latest_granting;
91
92 /* Forward declaration. */
93 static int context_struct_to_string(struct context *context, char **scontext,
94 u32 *scontext_len);
95
96 static void context_struct_compute_av(struct context *scontext,
97 struct context *tcontext,
98 u16 tclass,
99 struct av_decision *avd);
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 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
571 return; /* no masked permission */
572 masked = ~lo_avd.allowed & avd->allowed;
573 }
574
575 if (target->bounds) {
576 memset(&lo_avd, 0, sizeof(lo_avd));
577
578 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
579 lo_tcontext.type = target->bounds;
580
581 context_struct_compute_av(scontext,
582 &lo_tcontext,
583 tclass,
584 &lo_avd);
585 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
586 return; /* no masked permission */
587 masked = ~lo_avd.allowed & avd->allowed;
588 }
589
590 if (source->bounds && target->bounds) {
591 memset(&lo_avd, 0, sizeof(lo_avd));
592 /*
593 * lo_scontext and lo_tcontext are already
594 * set up.
595 */
596
597 context_struct_compute_av(&lo_scontext,
598 &lo_tcontext,
599 tclass,
600 &lo_avd);
601 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
602 return; /* no masked permission */
603 masked = ~lo_avd.allowed & avd->allowed;
604 }
605
606 if (masked) {
607 /* mask violated permissions */
608 avd->allowed &= ~masked;
609
610 /* audit masked permissions */
611 security_dump_masked_av(scontext, tcontext,
612 tclass, masked, "bounds");
613 }
614 }
615
616 /*
617 * Compute access vectors based on a context structure pair for
618 * the permissions in a particular class.
619 */
620 static void context_struct_compute_av(struct context *scontext,
621 struct context *tcontext,
622 u16 tclass,
623 struct av_decision *avd)
624 {
625 struct constraint_node *constraint;
626 struct role_allow *ra;
627 struct avtab_key avkey;
628 struct avtab_node *node;
629 struct class_datum *tclass_datum;
630 struct ebitmap *sattr, *tattr;
631 struct ebitmap_node *snode, *tnode;
632 unsigned int i, j;
633
634 avd->allowed = 0;
635 avd->auditallow = 0;
636 avd->auditdeny = 0xffffffff;
637
638 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
639 if (printk_ratelimit())
640 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
641 return;
642 }
643
644 tclass_datum = policydb.class_val_to_struct[tclass - 1];
645
646 /*
647 * If a specific type enforcement rule was defined for
648 * this permission check, then use it.
649 */
650 avkey.target_class = tclass;
651 avkey.specified = AVTAB_AV;
652 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
653 BUG_ON(!sattr);
654 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
655 BUG_ON(!tattr);
656 ebitmap_for_each_positive_bit(sattr, snode, i) {
657 ebitmap_for_each_positive_bit(tattr, tnode, j) {
658 avkey.source_type = i + 1;
659 avkey.target_type = j + 1;
660 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
661 node;
662 node = avtab_search_node_next(node, avkey.specified)) {
663 if (node->key.specified == AVTAB_ALLOWED)
664 avd->allowed |= node->datum.data;
665 else if (node->key.specified == AVTAB_AUDITALLOW)
666 avd->auditallow |= node->datum.data;
667 else if (node->key.specified == AVTAB_AUDITDENY)
668 avd->auditdeny &= node->datum.data;
669 }
670
671 /* Check conditional av table for additional permissions */
672 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
673
674 }
675 }
676
677 /*
678 * Remove any permissions prohibited by a constraint (this includes
679 * the MLS policy).
680 */
681 constraint = tclass_datum->constraints;
682 while (constraint) {
683 if ((constraint->permissions & (avd->allowed)) &&
684 !constraint_expr_eval(scontext, tcontext, NULL,
685 constraint->expr)) {
686 avd->allowed &= ~(constraint->permissions);
687 }
688 constraint = constraint->next;
689 }
690
691 /*
692 * If checking process transition permission and the
693 * role is changing, then check the (current_role, new_role)
694 * pair.
695 */
696 if (tclass == policydb.process_class &&
697 (avd->allowed & policydb.process_trans_perms) &&
698 scontext->role != tcontext->role) {
699 for (ra = policydb.role_allow; ra; ra = ra->next) {
700 if (scontext->role == ra->role &&
701 tcontext->role == ra->new_role)
702 break;
703 }
704 if (!ra)
705 avd->allowed &= ~policydb.process_trans_perms;
706 }
707
708 /*
709 * If the given source and target types have boundary
710 * constraint, lazy checks have to mask any violated
711 * permission and notice it to userspace via audit.
712 */
713 type_attribute_bounds_av(scontext, tcontext,
714 tclass, avd);
715 }
716
717 static int security_validtrans_handle_fail(struct context *ocontext,
718 struct context *ncontext,
719 struct context *tcontext,
720 u16 tclass)
721 {
722 char *o = NULL, *n = NULL, *t = NULL;
723 u32 olen, nlen, tlen;
724
725 if (context_struct_to_string(ocontext, &o, &olen))
726 goto out;
727 if (context_struct_to_string(ncontext, &n, &nlen))
728 goto out;
729 if (context_struct_to_string(tcontext, &t, &tlen))
730 goto out;
731 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
732 "security_validate_transition: denied for"
733 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
734 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
735 out:
736 kfree(o);
737 kfree(n);
738 kfree(t);
739
740 if (!selinux_enforcing)
741 return 0;
742 return -EPERM;
743 }
744
745 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
746 u16 orig_tclass)
747 {
748 struct context *ocontext;
749 struct context *ncontext;
750 struct context *tcontext;
751 struct class_datum *tclass_datum;
752 struct constraint_node *constraint;
753 u16 tclass;
754 int rc = 0;
755
756 if (!ss_initialized)
757 return 0;
758
759 read_lock(&policy_rwlock);
760
761 tclass = unmap_class(orig_tclass);
762
763 if (!tclass || tclass > policydb.p_classes.nprim) {
764 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
765 __func__, tclass);
766 rc = -EINVAL;
767 goto out;
768 }
769 tclass_datum = policydb.class_val_to_struct[tclass - 1];
770
771 ocontext = sidtab_search(&sidtab, oldsid);
772 if (!ocontext) {
773 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
774 __func__, oldsid);
775 rc = -EINVAL;
776 goto out;
777 }
778
779 ncontext = sidtab_search(&sidtab, newsid);
780 if (!ncontext) {
781 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
782 __func__, newsid);
783 rc = -EINVAL;
784 goto out;
785 }
786
787 tcontext = sidtab_search(&sidtab, tasksid);
788 if (!tcontext) {
789 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
790 __func__, tasksid);
791 rc = -EINVAL;
792 goto out;
793 }
794
795 constraint = tclass_datum->validatetrans;
796 while (constraint) {
797 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
798 constraint->expr)) {
799 rc = security_validtrans_handle_fail(ocontext, ncontext,
800 tcontext, tclass);
801 goto out;
802 }
803 constraint = constraint->next;
804 }
805
806 out:
807 read_unlock(&policy_rwlock);
808 return rc;
809 }
810
811 /*
812 * security_bounded_transition - check whether the given
813 * transition is directed to bounded, or not.
814 * It returns 0, if @newsid is bounded by @oldsid.
815 * Otherwise, it returns error code.
816 *
817 * @oldsid : current security identifier
818 * @newsid : destinated security identifier
819 */
820 int security_bounded_transition(u32 old_sid, u32 new_sid)
821 {
822 struct context *old_context, *new_context;
823 struct type_datum *type;
824 int index;
825 int rc;
826
827 read_lock(&policy_rwlock);
828
829 rc = -EINVAL;
830 old_context = sidtab_search(&sidtab, old_sid);
831 if (!old_context) {
832 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
833 __func__, old_sid);
834 goto out;
835 }
836
837 rc = -EINVAL;
838 new_context = sidtab_search(&sidtab, new_sid);
839 if (!new_context) {
840 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
841 __func__, new_sid);
842 goto out;
843 }
844
845 rc = 0;
846 /* type/domain unchanged */
847 if (old_context->type == new_context->type)
848 goto out;
849
850 index = new_context->type;
851 while (true) {
852 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
853 index - 1);
854 BUG_ON(!type);
855
856 /* not bounded anymore */
857 rc = -EPERM;
858 if (!type->bounds)
859 break;
860
861 /* @newsid is bounded by @oldsid */
862 rc = 0;
863 if (type->bounds == old_context->type)
864 break;
865
866 index = type->bounds;
867 }
868
869 if (rc) {
870 char *old_name = NULL;
871 char *new_name = NULL;
872 u32 length;
873
874 if (!context_struct_to_string(old_context,
875 &old_name, &length) &&
876 !context_struct_to_string(new_context,
877 &new_name, &length)) {
878 audit_log(current->audit_context,
879 GFP_ATOMIC, AUDIT_SELINUX_ERR,
880 "op=security_bounded_transition "
881 "result=denied "
882 "oldcontext=%s newcontext=%s",
883 old_name, new_name);
884 }
885 kfree(new_name);
886 kfree(old_name);
887 }
888 out:
889 read_unlock(&policy_rwlock);
890
891 return rc;
892 }
893
894 static void avd_init(struct av_decision *avd)
895 {
896 avd->allowed = 0;
897 avd->auditallow = 0;
898 avd->auditdeny = 0xffffffff;
899 avd->seqno = latest_granting;
900 avd->flags = 0;
901 }
902
903
904 /**
905 * security_compute_av - Compute access vector decisions.
906 * @ssid: source security identifier
907 * @tsid: target security identifier
908 * @tclass: target security class
909 * @avd: access vector decisions
910 *
911 * Compute a set of access vector decisions based on the
912 * SID pair (@ssid, @tsid) for the permissions in @tclass.
913 */
914 void security_compute_av(u32 ssid,
915 u32 tsid,
916 u16 orig_tclass,
917 struct av_decision *avd)
918 {
919 u16 tclass;
920 struct context *scontext = NULL, *tcontext = NULL;
921
922 read_lock(&policy_rwlock);
923 avd_init(avd);
924 if (!ss_initialized)
925 goto allow;
926
927 scontext = sidtab_search(&sidtab, ssid);
928 if (!scontext) {
929 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
930 __func__, ssid);
931 goto out;
932 }
933
934 /* permissive domain? */
935 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
936 avd->flags |= AVD_FLAGS_PERMISSIVE;
937
938 tcontext = sidtab_search(&sidtab, tsid);
939 if (!tcontext) {
940 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
941 __func__, tsid);
942 goto out;
943 }
944
945 tclass = unmap_class(orig_tclass);
946 if (unlikely(orig_tclass && !tclass)) {
947 if (policydb.allow_unknown)
948 goto allow;
949 goto out;
950 }
951 context_struct_compute_av(scontext, tcontext, tclass, avd);
952 map_decision(orig_tclass, avd, policydb.allow_unknown);
953 out:
954 read_unlock(&policy_rwlock);
955 return;
956 allow:
957 avd->allowed = 0xffffffff;
958 goto out;
959 }
960
961 void security_compute_av_user(u32 ssid,
962 u32 tsid,
963 u16 tclass,
964 struct av_decision *avd)
965 {
966 struct context *scontext = NULL, *tcontext = NULL;
967
968 read_lock(&policy_rwlock);
969 avd_init(avd);
970 if (!ss_initialized)
971 goto allow;
972
973 scontext = sidtab_search(&sidtab, ssid);
974 if (!scontext) {
975 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
976 __func__, ssid);
977 goto out;
978 }
979
980 /* permissive domain? */
981 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
982 avd->flags |= AVD_FLAGS_PERMISSIVE;
983
984 tcontext = sidtab_search(&sidtab, tsid);
985 if (!tcontext) {
986 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
987 __func__, tsid);
988 goto out;
989 }
990
991 if (unlikely(!tclass)) {
992 if (policydb.allow_unknown)
993 goto allow;
994 goto out;
995 }
996
997 context_struct_compute_av(scontext, tcontext, tclass, avd);
998 out:
999 read_unlock(&policy_rwlock);
1000 return;
1001 allow:
1002 avd->allowed = 0xffffffff;
1003 goto out;
1004 }
1005
1006 /*
1007 * Write the security context string representation of
1008 * the context structure `context' into a dynamically
1009 * allocated string of the correct size. Set `*scontext'
1010 * to point to this string and set `*scontext_len' to
1011 * the length of the string.
1012 */
1013 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1014 {
1015 char *scontextp;
1016
1017 if (scontext)
1018 *scontext = NULL;
1019 *scontext_len = 0;
1020
1021 if (context->len) {
1022 *scontext_len = context->len;
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 return 0;
1027 }
1028
1029 /* Compute the size of the context. */
1030 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033 *scontext_len += mls_compute_context_len(context);
1034
1035 if (!scontext)
1036 return 0;
1037
1038 /* Allocate space for the context; caller must free this space. */
1039 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040 if (!scontextp)
1041 return -ENOMEM;
1042 *scontext = scontextp;
1043
1044 /*
1045 * Copy the user name, role name and type name into the context.
1046 */
1047 sprintf(scontextp, "%s:%s:%s",
1048 sym_name(&policydb, SYM_USERS, context->user - 1),
1049 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054
1055 mls_sid_to_context(context, &scontextp);
1056
1057 *scontextp = 0;
1058
1059 return 0;
1060 }
1061
1062 #include "initial_sid_to_string.h"
1063
1064 const char *security_get_initial_sid_context(u32 sid)
1065 {
1066 if (unlikely(sid > SECINITSID_NUM))
1067 return NULL;
1068 return initial_sid_to_string[sid];
1069 }
1070
1071 static int security_sid_to_context_core(u32 sid, char **scontext,
1072 u32 *scontext_len, int force)
1073 {
1074 struct context *context;
1075 int rc = 0;
1076
1077 if (scontext)
1078 *scontext = NULL;
1079 *scontext_len = 0;
1080
1081 if (!ss_initialized) {
1082 if (sid <= SECINITSID_NUM) {
1083 char *scontextp;
1084
1085 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086 if (!scontext)
1087 goto out;
1088 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089 if (!scontextp) {
1090 rc = -ENOMEM;
1091 goto out;
1092 }
1093 strcpy(scontextp, initial_sid_to_string[sid]);
1094 *scontext = scontextp;
1095 goto out;
1096 }
1097 printk(KERN_ERR "SELinux: %s: called before initial "
1098 "load_policy on unknown SID %d\n", __func__, sid);
1099 rc = -EINVAL;
1100 goto out;
1101 }
1102 read_lock(&policy_rwlock);
1103 if (force)
1104 context = sidtab_search_force(&sidtab, sid);
1105 else
1106 context = sidtab_search(&sidtab, sid);
1107 if (!context) {
1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1109 __func__, sid);
1110 rc = -EINVAL;
1111 goto out_unlock;
1112 }
1113 rc = context_struct_to_string(context, scontext, scontext_len);
1114 out_unlock:
1115 read_unlock(&policy_rwlock);
1116 out:
1117 return rc;
1118
1119 }
1120
1121 /**
1122 * security_sid_to_context - Obtain a context for a given SID.
1123 * @sid: security identifier, SID
1124 * @scontext: security context
1125 * @scontext_len: length in bytes
1126 *
1127 * Write the string representation of the context associated with @sid
1128 * into a dynamically allocated string of the correct size. Set @scontext
1129 * to point to this string and set @scontext_len to the length of the string.
1130 */
1131 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132 {
1133 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134 }
1135
1136 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137 {
1138 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139 }
1140
1141 /*
1142 * Caveat: Mutates scontext.
1143 */
1144 static int string_to_context_struct(struct policydb *pol,
1145 struct sidtab *sidtabp,
1146 char *scontext,
1147 u32 scontext_len,
1148 struct context *ctx,
1149 u32 def_sid)
1150 {
1151 struct role_datum *role;
1152 struct type_datum *typdatum;
1153 struct user_datum *usrdatum;
1154 char *scontextp, *p, oldc;
1155 int rc = 0;
1156
1157 context_init(ctx);
1158
1159 /* Parse the security context. */
1160
1161 rc = -EINVAL;
1162 scontextp = (char *) scontext;
1163
1164 /* Extract the user. */
1165 p = scontextp;
1166 while (*p && *p != ':')
1167 p++;
1168
1169 if (*p == 0)
1170 goto out;
1171
1172 *p++ = 0;
1173
1174 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175 if (!usrdatum)
1176 goto out;
1177
1178 ctx->user = usrdatum->value;
1179
1180 /* Extract role. */
1181 scontextp = p;
1182 while (*p && *p != ':')
1183 p++;
1184
1185 if (*p == 0)
1186 goto out;
1187
1188 *p++ = 0;
1189
1190 role = hashtab_search(pol->p_roles.table, scontextp);
1191 if (!role)
1192 goto out;
1193 ctx->role = role->value;
1194
1195 /* Extract type. */
1196 scontextp = p;
1197 while (*p && *p != ':')
1198 p++;
1199 oldc = *p;
1200 *p++ = 0;
1201
1202 typdatum = hashtab_search(pol->p_types.table, scontextp);
1203 if (!typdatum || typdatum->attribute)
1204 goto out;
1205
1206 ctx->type = typdatum->value;
1207
1208 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209 if (rc)
1210 goto out;
1211
1212 rc = -EINVAL;
1213 if ((p - scontext) < scontext_len)
1214 goto out;
1215
1216 /* Check the validity of the new context. */
1217 if (!policydb_context_isvalid(pol, ctx))
1218 goto out;
1219 rc = 0;
1220 out:
1221 if (rc)
1222 context_destroy(ctx);
1223 return rc;
1224 }
1225
1226 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228 int force)
1229 {
1230 char *scontext2, *str = NULL;
1231 struct context context;
1232 int rc = 0;
1233
1234 if (!ss_initialized) {
1235 int i;
1236
1237 for (i = 1; i < SECINITSID_NUM; i++) {
1238 if (!strcmp(initial_sid_to_string[i], scontext)) {
1239 *sid = i;
1240 return 0;
1241 }
1242 }
1243 *sid = SECINITSID_KERNEL;
1244 return 0;
1245 }
1246 *sid = SECSID_NULL;
1247
1248 /* Copy the string so that we can modify the copy as we parse it. */
1249 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1250 if (!scontext2)
1251 return -ENOMEM;
1252 memcpy(scontext2, scontext, scontext_len);
1253 scontext2[scontext_len] = 0;
1254
1255 if (force) {
1256 /* Save another copy for storing in uninterpreted form */
1257 rc = -ENOMEM;
1258 str = kstrdup(scontext2, gfp_flags);
1259 if (!str)
1260 goto out;
1261 }
1262
1263 read_lock(&policy_rwlock);
1264 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1265 scontext_len, &context, def_sid);
1266 if (rc == -EINVAL && force) {
1267 context.str = str;
1268 context.len = scontext_len;
1269 str = NULL;
1270 } else if (rc)
1271 goto out_unlock;
1272 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1273 context_destroy(&context);
1274 out_unlock:
1275 read_unlock(&policy_rwlock);
1276 out:
1277 kfree(scontext2);
1278 kfree(str);
1279 return rc;
1280 }
1281
1282 /**
1283 * security_context_to_sid - Obtain a SID for a given security context.
1284 * @scontext: security context
1285 * @scontext_len: length in bytes
1286 * @sid: security identifier, SID
1287 *
1288 * Obtains a SID associated with the security context that
1289 * has the string representation specified by @scontext.
1290 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1291 * memory is available, or 0 on success.
1292 */
1293 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1294 {
1295 return security_context_to_sid_core(scontext, scontext_len,
1296 sid, SECSID_NULL, GFP_KERNEL, 0);
1297 }
1298
1299 /**
1300 * security_context_to_sid_default - Obtain a SID for a given security context,
1301 * falling back to specified default if needed.
1302 *
1303 * @scontext: security context
1304 * @scontext_len: length in bytes
1305 * @sid: security identifier, SID
1306 * @def_sid: default SID to assign on error
1307 *
1308 * Obtains a SID associated with the security context that
1309 * has the string representation specified by @scontext.
1310 * The default SID is passed to the MLS layer to be used to allow
1311 * kernel labeling of the MLS field if the MLS field is not present
1312 * (for upgrading to MLS without full relabel).
1313 * Implicitly forces adding of the context even if it cannot be mapped yet.
1314 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1315 * memory is available, or 0 on success.
1316 */
1317 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1318 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1319 {
1320 return security_context_to_sid_core(scontext, scontext_len,
1321 sid, def_sid, gfp_flags, 1);
1322 }
1323
1324 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1325 u32 *sid)
1326 {
1327 return security_context_to_sid_core(scontext, scontext_len,
1328 sid, SECSID_NULL, GFP_KERNEL, 1);
1329 }
1330
1331 static int compute_sid_handle_invalid_context(
1332 struct context *scontext,
1333 struct context *tcontext,
1334 u16 tclass,
1335 struct context *newcontext)
1336 {
1337 char *s = NULL, *t = NULL, *n = NULL;
1338 u32 slen, tlen, nlen;
1339
1340 if (context_struct_to_string(scontext, &s, &slen))
1341 goto out;
1342 if (context_struct_to_string(tcontext, &t, &tlen))
1343 goto out;
1344 if (context_struct_to_string(newcontext, &n, &nlen))
1345 goto out;
1346 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1347 "security_compute_sid: invalid context %s"
1348 " for scontext=%s"
1349 " tcontext=%s"
1350 " tclass=%s",
1351 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1352 out:
1353 kfree(s);
1354 kfree(t);
1355 kfree(n);
1356 if (!selinux_enforcing)
1357 return 0;
1358 return -EACCES;
1359 }
1360
1361 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1362 u32 stype, u32 ttype, u16 tclass,
1363 const char *objname)
1364 {
1365 struct filename_trans ft;
1366 struct filename_trans_datum *otype;
1367
1368 /*
1369 * Most filename trans rules are going to live in specific directories
1370 * like /dev or /var/run. This bitmap will quickly skip rule searches
1371 * if the ttype does not contain any rules.
1372 */
1373 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1374 return;
1375
1376 ft.stype = stype;
1377 ft.ttype = ttype;
1378 ft.tclass = tclass;
1379 ft.name = objname;
1380
1381 otype = hashtab_search(p->filename_trans, &ft);
1382 if (otype)
1383 newcontext->type = otype->otype;
1384 }
1385
1386 static int security_compute_sid(u32 ssid,
1387 u32 tsid,
1388 u16 orig_tclass,
1389 u32 specified,
1390 const char *objname,
1391 u32 *out_sid,
1392 bool kern)
1393 {
1394 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1395 struct role_trans *roletr = NULL;
1396 struct avtab_key avkey;
1397 struct avtab_datum *avdatum;
1398 struct avtab_node *node;
1399 u16 tclass;
1400 int rc = 0;
1401 bool sock;
1402
1403 if (!ss_initialized) {
1404 switch (orig_tclass) {
1405 case SECCLASS_PROCESS: /* kernel value */
1406 *out_sid = ssid;
1407 break;
1408 default:
1409 *out_sid = tsid;
1410 break;
1411 }
1412 goto out;
1413 }
1414
1415 context_init(&newcontext);
1416
1417 read_lock(&policy_rwlock);
1418
1419 if (kern) {
1420 tclass = unmap_class(orig_tclass);
1421 sock = security_is_socket_class(orig_tclass);
1422 } else {
1423 tclass = orig_tclass;
1424 sock = security_is_socket_class(map_class(tclass));
1425 }
1426
1427 scontext = sidtab_search(&sidtab, ssid);
1428 if (!scontext) {
1429 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1430 __func__, ssid);
1431 rc = -EINVAL;
1432 goto out_unlock;
1433 }
1434 tcontext = sidtab_search(&sidtab, tsid);
1435 if (!tcontext) {
1436 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1437 __func__, tsid);
1438 rc = -EINVAL;
1439 goto out_unlock;
1440 }
1441
1442 /* Set the user identity. */
1443 switch (specified) {
1444 case AVTAB_TRANSITION:
1445 case AVTAB_CHANGE:
1446 /* Use the process user identity. */
1447 newcontext.user = scontext->user;
1448 break;
1449 case AVTAB_MEMBER:
1450 /* Use the related object owner. */
1451 newcontext.user = tcontext->user;
1452 break;
1453 }
1454
1455 /* Set the role and type to default values. */
1456 if ((tclass == policydb.process_class) || (sock == true)) {
1457 /* Use the current role and type of process. */
1458 newcontext.role = scontext->role;
1459 newcontext.type = scontext->type;
1460 } else {
1461 /* Use the well-defined object role. */
1462 newcontext.role = OBJECT_R_VAL;
1463 /* Use the type of the related object. */
1464 newcontext.type = tcontext->type;
1465 }
1466
1467 /* Look for a type transition/member/change rule. */
1468 avkey.source_type = scontext->type;
1469 avkey.target_type = tcontext->type;
1470 avkey.target_class = tclass;
1471 avkey.specified = specified;
1472 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1473
1474 /* If no permanent rule, also check for enabled conditional rules */
1475 if (!avdatum) {
1476 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1477 for (; node; node = avtab_search_node_next(node, specified)) {
1478 if (node->key.specified & AVTAB_ENABLED) {
1479 avdatum = &node->datum;
1480 break;
1481 }
1482 }
1483 }
1484
1485 if (avdatum) {
1486 /* Use the type from the type transition/member/change rule. */
1487 newcontext.type = avdatum->data;
1488 }
1489
1490 /* if we have a objname this is a file trans check so check those rules */
1491 if (objname)
1492 filename_compute_type(&policydb, &newcontext, scontext->type,
1493 tcontext->type, tclass, objname);
1494
1495 /* Check for class-specific changes. */
1496 if (specified & AVTAB_TRANSITION) {
1497 /* Look for a role transition rule. */
1498 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1499 if ((roletr->role == scontext->role) &&
1500 (roletr->type == tcontext->type) &&
1501 (roletr->tclass == tclass)) {
1502 /* Use the role transition rule. */
1503 newcontext.role = roletr->new_role;
1504 break;
1505 }
1506 }
1507 }
1508
1509 /* Set the MLS attributes.
1510 This is done last because it may allocate memory. */
1511 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1512 &newcontext, sock);
1513 if (rc)
1514 goto out_unlock;
1515
1516 /* Check the validity of the context. */
1517 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1518 rc = compute_sid_handle_invalid_context(scontext,
1519 tcontext,
1520 tclass,
1521 &newcontext);
1522 if (rc)
1523 goto out_unlock;
1524 }
1525 /* Obtain the sid for the context. */
1526 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1527 out_unlock:
1528 read_unlock(&policy_rwlock);
1529 context_destroy(&newcontext);
1530 out:
1531 return rc;
1532 }
1533
1534 /**
1535 * security_transition_sid - Compute the SID for a new subject/object.
1536 * @ssid: source security identifier
1537 * @tsid: target security identifier
1538 * @tclass: target security class
1539 * @out_sid: security identifier for new subject/object
1540 *
1541 * Compute a SID to use for labeling a new subject or object in the
1542 * class @tclass based on a SID pair (@ssid, @tsid).
1543 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1544 * if insufficient memory is available, or %0 if the new SID was
1545 * computed successfully.
1546 */
1547 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1548 const struct qstr *qstr, u32 *out_sid)
1549 {
1550 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1551 qstr ? qstr->name : NULL, out_sid, true);
1552 }
1553
1554 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1555 const char *objname, u32 *out_sid)
1556 {
1557 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1558 objname, out_sid, false);
1559 }
1560
1561 /**
1562 * security_member_sid - Compute the SID for member selection.
1563 * @ssid: source security identifier
1564 * @tsid: target security identifier
1565 * @tclass: target security class
1566 * @out_sid: security identifier for selected member
1567 *
1568 * Compute a SID to use when selecting a member of a polyinstantiated
1569 * object of class @tclass based on a SID pair (@ssid, @tsid).
1570 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1571 * if insufficient memory is available, or %0 if the SID was
1572 * computed successfully.
1573 */
1574 int security_member_sid(u32 ssid,
1575 u32 tsid,
1576 u16 tclass,
1577 u32 *out_sid)
1578 {
1579 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1580 out_sid, false);
1581 }
1582
1583 /**
1584 * security_change_sid - Compute the SID for object relabeling.
1585 * @ssid: source security identifier
1586 * @tsid: target security identifier
1587 * @tclass: target security class
1588 * @out_sid: security identifier for selected member
1589 *
1590 * Compute a SID to use for relabeling an object of class @tclass
1591 * based on a SID pair (@ssid, @tsid).
1592 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1593 * if insufficient memory is available, or %0 if the SID was
1594 * computed successfully.
1595 */
1596 int security_change_sid(u32 ssid,
1597 u32 tsid,
1598 u16 tclass,
1599 u32 *out_sid)
1600 {
1601 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1602 out_sid, false);
1603 }
1604
1605 /* Clone the SID into the new SID table. */
1606 static int clone_sid(u32 sid,
1607 struct context *context,
1608 void *arg)
1609 {
1610 struct sidtab *s = arg;
1611
1612 if (sid > SECINITSID_NUM)
1613 return sidtab_insert(s, sid, context);
1614 else
1615 return 0;
1616 }
1617
1618 static inline int convert_context_handle_invalid_context(struct context *context)
1619 {
1620 char *s;
1621 u32 len;
1622
1623 if (selinux_enforcing)
1624 return -EINVAL;
1625
1626 if (!context_struct_to_string(context, &s, &len)) {
1627 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1628 kfree(s);
1629 }
1630 return 0;
1631 }
1632
1633 struct convert_context_args {
1634 struct policydb *oldp;
1635 struct policydb *newp;
1636 };
1637
1638 /*
1639 * Convert the values in the security context
1640 * structure `c' from the values specified
1641 * in the policy `p->oldp' to the values specified
1642 * in the policy `p->newp'. Verify that the
1643 * context is valid under the new policy.
1644 */
1645 static int convert_context(u32 key,
1646 struct context *c,
1647 void *p)
1648 {
1649 struct convert_context_args *args;
1650 struct context oldc;
1651 struct ocontext *oc;
1652 struct mls_range *range;
1653 struct role_datum *role;
1654 struct type_datum *typdatum;
1655 struct user_datum *usrdatum;
1656 char *s;
1657 u32 len;
1658 int rc = 0;
1659
1660 if (key <= SECINITSID_NUM)
1661 goto out;
1662
1663 args = p;
1664
1665 if (c->str) {
1666 struct context ctx;
1667
1668 rc = -ENOMEM;
1669 s = kstrdup(c->str, GFP_KERNEL);
1670 if (!s)
1671 goto out;
1672
1673 rc = string_to_context_struct(args->newp, NULL, s,
1674 c->len, &ctx, SECSID_NULL);
1675 kfree(s);
1676 if (!rc) {
1677 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1678 c->str);
1679 /* Replace string with mapped representation. */
1680 kfree(c->str);
1681 memcpy(c, &ctx, sizeof(*c));
1682 goto out;
1683 } else if (rc == -EINVAL) {
1684 /* Retain string representation for later mapping. */
1685 rc = 0;
1686 goto out;
1687 } else {
1688 /* Other error condition, e.g. ENOMEM. */
1689 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1690 c->str, -rc);
1691 goto out;
1692 }
1693 }
1694
1695 rc = context_cpy(&oldc, c);
1696 if (rc)
1697 goto out;
1698
1699 /* Convert the user. */
1700 rc = -EINVAL;
1701 usrdatum = hashtab_search(args->newp->p_users.table,
1702 sym_name(args->oldp, SYM_USERS, c->user - 1));
1703 if (!usrdatum)
1704 goto bad;
1705 c->user = usrdatum->value;
1706
1707 /* Convert the role. */
1708 rc = -EINVAL;
1709 role = hashtab_search(args->newp->p_roles.table,
1710 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1711 if (!role)
1712 goto bad;
1713 c->role = role->value;
1714
1715 /* Convert the type. */
1716 rc = -EINVAL;
1717 typdatum = hashtab_search(args->newp->p_types.table,
1718 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1719 if (!typdatum)
1720 goto bad;
1721 c->type = typdatum->value;
1722
1723 /* Convert the MLS fields if dealing with MLS policies */
1724 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1725 rc = mls_convert_context(args->oldp, args->newp, c);
1726 if (rc)
1727 goto bad;
1728 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1729 /*
1730 * Switching between MLS and non-MLS policy:
1731 * free any storage used by the MLS fields in the
1732 * context for all existing entries in the sidtab.
1733 */
1734 mls_context_destroy(c);
1735 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1736 /*
1737 * Switching between non-MLS and MLS policy:
1738 * ensure that the MLS fields of the context for all
1739 * existing entries in the sidtab are filled in with a
1740 * suitable default value, likely taken from one of the
1741 * initial SIDs.
1742 */
1743 oc = args->newp->ocontexts[OCON_ISID];
1744 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1745 oc = oc->next;
1746 rc = -EINVAL;
1747 if (!oc) {
1748 printk(KERN_ERR "SELinux: unable to look up"
1749 " the initial SIDs list\n");
1750 goto bad;
1751 }
1752 range = &oc->context[0].range;
1753 rc = mls_range_set(c, range);
1754 if (rc)
1755 goto bad;
1756 }
1757
1758 /* Check the validity of the new context. */
1759 if (!policydb_context_isvalid(args->newp, c)) {
1760 rc = convert_context_handle_invalid_context(&oldc);
1761 if (rc)
1762 goto bad;
1763 }
1764
1765 context_destroy(&oldc);
1766
1767 rc = 0;
1768 out:
1769 return rc;
1770 bad:
1771 /* Map old representation to string and save it. */
1772 rc = context_struct_to_string(&oldc, &s, &len);
1773 if (rc)
1774 return rc;
1775 context_destroy(&oldc);
1776 context_destroy(c);
1777 c->str = s;
1778 c->len = len;
1779 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1780 c->str);
1781 rc = 0;
1782 goto out;
1783 }
1784
1785 static void security_load_policycaps(void)
1786 {
1787 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1788 POLICYDB_CAPABILITY_NETPEER);
1789 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1790 POLICYDB_CAPABILITY_OPENPERM);
1791 }
1792
1793 extern void selinux_complete_init(void);
1794 static int security_preserve_bools(struct policydb *p);
1795
1796 /**
1797 * security_load_policy - Load a security policy configuration.
1798 * @data: binary policy data
1799 * @len: length of data in bytes
1800 *
1801 * Load a new set of security policy configuration data,
1802 * validate it and convert the SID table as necessary.
1803 * This function will flush the access vector cache after
1804 * loading the new policy.
1805 */
1806 int security_load_policy(void *data, size_t len)
1807 {
1808 struct policydb oldpolicydb, newpolicydb;
1809 struct sidtab oldsidtab, newsidtab;
1810 struct selinux_mapping *oldmap, *map = NULL;
1811 struct convert_context_args args;
1812 u32 seqno;
1813 u16 map_size;
1814 int rc = 0;
1815 struct policy_file file = { data, len }, *fp = &file;
1816
1817 if (!ss_initialized) {
1818 avtab_cache_init();
1819 rc = policydb_read(&policydb, fp);
1820 if (rc) {
1821 avtab_cache_destroy();
1822 return rc;
1823 }
1824
1825 policydb.len = len;
1826 rc = selinux_set_mapping(&policydb, secclass_map,
1827 &current_mapping,
1828 &current_mapping_size);
1829 if (rc) {
1830 policydb_destroy(&policydb);
1831 avtab_cache_destroy();
1832 return rc;
1833 }
1834
1835 rc = policydb_load_isids(&policydb, &sidtab);
1836 if (rc) {
1837 policydb_destroy(&policydb);
1838 avtab_cache_destroy();
1839 return rc;
1840 }
1841
1842 security_load_policycaps();
1843 ss_initialized = 1;
1844 seqno = ++latest_granting;
1845 selinux_complete_init();
1846 avc_ss_reset(seqno);
1847 selnl_notify_policyload(seqno);
1848 selinux_status_update_policyload(seqno);
1849 selinux_netlbl_cache_invalidate();
1850 selinux_xfrm_notify_policyload();
1851 return 0;
1852 }
1853
1854 #if 0
1855 sidtab_hash_eval(&sidtab, "sids");
1856 #endif
1857
1858 rc = policydb_read(&newpolicydb, fp);
1859 if (rc)
1860 return rc;
1861
1862 newpolicydb.len = len;
1863 /* If switching between different policy types, log MLS status */
1864 if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1865 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1866 else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1867 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1868
1869 rc = policydb_load_isids(&newpolicydb, &newsidtab);
1870 if (rc) {
1871 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1872 policydb_destroy(&newpolicydb);
1873 return rc;
1874 }
1875
1876 rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1877 if (rc)
1878 goto err;
1879
1880 rc = security_preserve_bools(&newpolicydb);
1881 if (rc) {
1882 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1883 goto err;
1884 }
1885
1886 /* Clone the SID table. */
1887 sidtab_shutdown(&sidtab);
1888
1889 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1890 if (rc)
1891 goto err;
1892
1893 /*
1894 * Convert the internal representations of contexts
1895 * in the new SID table.
1896 */
1897 args.oldp = &policydb;
1898 args.newp = &newpolicydb;
1899 rc = sidtab_map(&newsidtab, convert_context, &args);
1900 if (rc) {
1901 printk(KERN_ERR "SELinux: unable to convert the internal"
1902 " representation of contexts in the new SID"
1903 " table\n");
1904 goto err;
1905 }
1906
1907 /* Save the old policydb and SID table to free later. */
1908 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1909 sidtab_set(&oldsidtab, &sidtab);
1910
1911 /* Install the new policydb and SID table. */
1912 write_lock_irq(&policy_rwlock);
1913 memcpy(&policydb, &newpolicydb, sizeof policydb);
1914 sidtab_set(&sidtab, &newsidtab);
1915 security_load_policycaps();
1916 oldmap = current_mapping;
1917 current_mapping = map;
1918 current_mapping_size = map_size;
1919 seqno = ++latest_granting;
1920 write_unlock_irq(&policy_rwlock);
1921
1922 /* Free the old policydb and SID table. */
1923 policydb_destroy(&oldpolicydb);
1924 sidtab_destroy(&oldsidtab);
1925 kfree(oldmap);
1926
1927 avc_ss_reset(seqno);
1928 selnl_notify_policyload(seqno);
1929 selinux_status_update_policyload(seqno);
1930 selinux_netlbl_cache_invalidate();
1931 selinux_xfrm_notify_policyload();
1932
1933 return 0;
1934
1935 err:
1936 kfree(map);
1937 sidtab_destroy(&newsidtab);
1938 policydb_destroy(&newpolicydb);
1939 return rc;
1940
1941 }
1942
1943 size_t security_policydb_len(void)
1944 {
1945 size_t len;
1946
1947 read_lock(&policy_rwlock);
1948 len = policydb.len;
1949 read_unlock(&policy_rwlock);
1950
1951 return len;
1952 }
1953
1954 /**
1955 * security_port_sid - Obtain the SID for a port.
1956 * @protocol: protocol number
1957 * @port: port number
1958 * @out_sid: security identifier
1959 */
1960 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1961 {
1962 struct ocontext *c;
1963 int rc = 0;
1964
1965 read_lock(&policy_rwlock);
1966
1967 c = policydb.ocontexts[OCON_PORT];
1968 while (c) {
1969 if (c->u.port.protocol == protocol &&
1970 c->u.port.low_port <= port &&
1971 c->u.port.high_port >= port)
1972 break;
1973 c = c->next;
1974 }
1975
1976 if (c) {
1977 if (!c->sid[0]) {
1978 rc = sidtab_context_to_sid(&sidtab,
1979 &c->context[0],
1980 &c->sid[0]);
1981 if (rc)
1982 goto out;
1983 }
1984 *out_sid = c->sid[0];
1985 } else {
1986 *out_sid = SECINITSID_PORT;
1987 }
1988
1989 out:
1990 read_unlock(&policy_rwlock);
1991 return rc;
1992 }
1993
1994 /**
1995 * security_netif_sid - Obtain the SID for a network interface.
1996 * @name: interface name
1997 * @if_sid: interface SID
1998 */
1999 int security_netif_sid(char *name, u32 *if_sid)
2000 {
2001 int rc = 0;
2002 struct ocontext *c;
2003
2004 read_lock(&policy_rwlock);
2005
2006 c = policydb.ocontexts[OCON_NETIF];
2007 while (c) {
2008 if (strcmp(name, c->u.name) == 0)
2009 break;
2010 c = c->next;
2011 }
2012
2013 if (c) {
2014 if (!c->sid[0] || !c->sid[1]) {
2015 rc = sidtab_context_to_sid(&sidtab,
2016 &c->context[0],
2017 &c->sid[0]);
2018 if (rc)
2019 goto out;
2020 rc = sidtab_context_to_sid(&sidtab,
2021 &c->context[1],
2022 &c->sid[1]);
2023 if (rc)
2024 goto out;
2025 }
2026 *if_sid = c->sid[0];
2027 } else
2028 *if_sid = SECINITSID_NETIF;
2029
2030 out:
2031 read_unlock(&policy_rwlock);
2032 return rc;
2033 }
2034
2035 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2036 {
2037 int i, fail = 0;
2038
2039 for (i = 0; i < 4; i++)
2040 if (addr[i] != (input[i] & mask[i])) {
2041 fail = 1;
2042 break;
2043 }
2044
2045 return !fail;
2046 }
2047
2048 /**
2049 * security_node_sid - Obtain the SID for a node (host).
2050 * @domain: communication domain aka address family
2051 * @addrp: address
2052 * @addrlen: address length in bytes
2053 * @out_sid: security identifier
2054 */
2055 int security_node_sid(u16 domain,
2056 void *addrp,
2057 u32 addrlen,
2058 u32 *out_sid)
2059 {
2060 int rc;
2061 struct ocontext *c;
2062
2063 read_lock(&policy_rwlock);
2064
2065 switch (domain) {
2066 case AF_INET: {
2067 u32 addr;
2068
2069 rc = -EINVAL;
2070 if (addrlen != sizeof(u32))
2071 goto out;
2072
2073 addr = *((u32 *)addrp);
2074
2075 c = policydb.ocontexts[OCON_NODE];
2076 while (c) {
2077 if (c->u.node.addr == (addr & c->u.node.mask))
2078 break;
2079 c = c->next;
2080 }
2081 break;
2082 }
2083
2084 case AF_INET6:
2085 rc = -EINVAL;
2086 if (addrlen != sizeof(u64) * 2)
2087 goto out;
2088 c = policydb.ocontexts[OCON_NODE6];
2089 while (c) {
2090 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2091 c->u.node6.mask))
2092 break;
2093 c = c->next;
2094 }
2095 break;
2096
2097 default:
2098 rc = 0;
2099 *out_sid = SECINITSID_NODE;
2100 goto out;
2101 }
2102
2103 if (c) {
2104 if (!c->sid[0]) {
2105 rc = sidtab_context_to_sid(&sidtab,
2106 &c->context[0],
2107 &c->sid[0]);
2108 if (rc)
2109 goto out;
2110 }
2111 *out_sid = c->sid[0];
2112 } else {
2113 *out_sid = SECINITSID_NODE;
2114 }
2115
2116 rc = 0;
2117 out:
2118 read_unlock(&policy_rwlock);
2119 return rc;
2120 }
2121
2122 #define SIDS_NEL 25
2123
2124 /**
2125 * security_get_user_sids - Obtain reachable SIDs for a user.
2126 * @fromsid: starting SID
2127 * @username: username
2128 * @sids: array of reachable SIDs for user
2129 * @nel: number of elements in @sids
2130 *
2131 * Generate the set of SIDs for legal security contexts
2132 * for a given user that can be reached by @fromsid.
2133 * Set *@sids to point to a dynamically allocated
2134 * array containing the set of SIDs. Set *@nel to the
2135 * number of elements in the array.
2136 */
2137
2138 int security_get_user_sids(u32 fromsid,
2139 char *username,
2140 u32 **sids,
2141 u32 *nel)
2142 {
2143 struct context *fromcon, usercon;
2144 u32 *mysids = NULL, *mysids2, sid;
2145 u32 mynel = 0, maxnel = SIDS_NEL;
2146 struct user_datum *user;
2147 struct role_datum *role;
2148 struct ebitmap_node *rnode, *tnode;
2149 int rc = 0, i, j;
2150
2151 *sids = NULL;
2152 *nel = 0;
2153
2154 if (!ss_initialized)
2155 goto out;
2156
2157 read_lock(&policy_rwlock);
2158
2159 context_init(&usercon);
2160
2161 rc = -EINVAL;
2162 fromcon = sidtab_search(&sidtab, fromsid);
2163 if (!fromcon)
2164 goto out_unlock;
2165
2166 rc = -EINVAL;
2167 user = hashtab_search(policydb.p_users.table, username);
2168 if (!user)
2169 goto out_unlock;
2170
2171 usercon.user = user->value;
2172
2173 rc = -ENOMEM;
2174 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2175 if (!mysids)
2176 goto out_unlock;
2177
2178 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2179 role = policydb.role_val_to_struct[i];
2180 usercon.role = i + 1;
2181 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2182 usercon.type = j + 1;
2183
2184 if (mls_setup_user_range(fromcon, user, &usercon))
2185 continue;
2186
2187 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2188 if (rc)
2189 goto out_unlock;
2190 if (mynel < maxnel) {
2191 mysids[mynel++] = sid;
2192 } else {
2193 rc = -ENOMEM;
2194 maxnel += SIDS_NEL;
2195 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2196 if (!mysids2)
2197 goto out_unlock;
2198 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2199 kfree(mysids);
2200 mysids = mysids2;
2201 mysids[mynel++] = sid;
2202 }
2203 }
2204 }
2205 rc = 0;
2206 out_unlock:
2207 read_unlock(&policy_rwlock);
2208 if (rc || !mynel) {
2209 kfree(mysids);
2210 goto out;
2211 }
2212
2213 rc = -ENOMEM;
2214 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2215 if (!mysids2) {
2216 kfree(mysids);
2217 goto out;
2218 }
2219 for (i = 0, j = 0; i < mynel; i++) {
2220 struct av_decision dummy_avd;
2221 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2222 SECCLASS_PROCESS, /* kernel value */
2223 PROCESS__TRANSITION, AVC_STRICT,
2224 &dummy_avd);
2225 if (!rc)
2226 mysids2[j++] = mysids[i];
2227 cond_resched();
2228 }
2229 rc = 0;
2230 kfree(mysids);
2231 *sids = mysids2;
2232 *nel = j;
2233 out:
2234 return rc;
2235 }
2236
2237 /**
2238 * security_genfs_sid - Obtain a SID for a file in a filesystem
2239 * @fstype: filesystem type
2240 * @path: path from root of mount
2241 * @sclass: file security class
2242 * @sid: SID for path
2243 *
2244 * Obtain a SID to use for a file in a filesystem that
2245 * cannot support xattr or use a fixed labeling behavior like
2246 * transition SIDs or task SIDs.
2247 */
2248 int security_genfs_sid(const char *fstype,
2249 char *path,
2250 u16 orig_sclass,
2251 u32 *sid)
2252 {
2253 int len;
2254 u16 sclass;
2255 struct genfs *genfs;
2256 struct ocontext *c;
2257 int rc, cmp = 0;
2258
2259 while (path[0] == '/' && path[1] == '/')
2260 path++;
2261
2262 read_lock(&policy_rwlock);
2263
2264 sclass = unmap_class(orig_sclass);
2265 *sid = SECINITSID_UNLABELED;
2266
2267 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2268 cmp = strcmp(fstype, genfs->fstype);
2269 if (cmp <= 0)
2270 break;
2271 }
2272
2273 rc = -ENOENT;
2274 if (!genfs || cmp)
2275 goto out;
2276
2277 for (c = genfs->head; c; c = c->next) {
2278 len = strlen(c->u.name);
2279 if ((!c->v.sclass || sclass == c->v.sclass) &&
2280 (strncmp(c->u.name, path, len) == 0))
2281 break;
2282 }
2283
2284 rc = -ENOENT;
2285 if (!c)
2286 goto out;
2287
2288 if (!c->sid[0]) {
2289 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2290 if (rc)
2291 goto out;
2292 }
2293
2294 *sid = c->sid[0];
2295 rc = 0;
2296 out:
2297 read_unlock(&policy_rwlock);
2298 return rc;
2299 }
2300
2301 /**
2302 * security_fs_use - Determine how to handle labeling for a filesystem.
2303 * @fstype: filesystem type
2304 * @behavior: labeling behavior
2305 * @sid: SID for filesystem (superblock)
2306 */
2307 int security_fs_use(
2308 const char *fstype,
2309 unsigned int *behavior,
2310 u32 *sid)
2311 {
2312 int rc = 0;
2313 struct ocontext *c;
2314
2315 read_lock(&policy_rwlock);
2316
2317 c = policydb.ocontexts[OCON_FSUSE];
2318 while (c) {
2319 if (strcmp(fstype, c->u.name) == 0)
2320 break;
2321 c = c->next;
2322 }
2323
2324 if (c) {
2325 *behavior = c->v.behavior;
2326 if (!c->sid[0]) {
2327 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2328 &c->sid[0]);
2329 if (rc)
2330 goto out;
2331 }
2332 *sid = c->sid[0];
2333 } else {
2334 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2335 if (rc) {
2336 *behavior = SECURITY_FS_USE_NONE;
2337 rc = 0;
2338 } else {
2339 *behavior = SECURITY_FS_USE_GENFS;
2340 }
2341 }
2342
2343 out:
2344 read_unlock(&policy_rwlock);
2345 return rc;
2346 }
2347
2348 int security_get_bools(int *len, char ***names, int **values)
2349 {
2350 int i, rc;
2351
2352 read_lock(&policy_rwlock);
2353 *names = NULL;
2354 *values = NULL;
2355
2356 rc = 0;
2357 *len = policydb.p_bools.nprim;
2358 if (!*len)
2359 goto out;
2360
2361 rc = -ENOMEM;
2362 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2363 if (!*names)
2364 goto err;
2365
2366 rc = -ENOMEM;
2367 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2368 if (!*values)
2369 goto err;
2370
2371 for (i = 0; i < *len; i++) {
2372 size_t name_len;
2373
2374 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2375 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2376
2377 rc = -ENOMEM;
2378 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2379 if (!(*names)[i])
2380 goto err;
2381
2382 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2383 (*names)[i][name_len - 1] = 0;
2384 }
2385 rc = 0;
2386 out:
2387 read_unlock(&policy_rwlock);
2388 return rc;
2389 err:
2390 if (*names) {
2391 for (i = 0; i < *len; i++)
2392 kfree((*names)[i]);
2393 }
2394 kfree(*values);
2395 goto out;
2396 }
2397
2398
2399 int security_set_bools(int len, int *values)
2400 {
2401 int i, rc;
2402 int lenp, seqno = 0;
2403 struct cond_node *cur;
2404
2405 write_lock_irq(&policy_rwlock);
2406
2407 rc = -EFAULT;
2408 lenp = policydb.p_bools.nprim;
2409 if (len != lenp)
2410 goto out;
2411
2412 for (i = 0; i < len; i++) {
2413 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2414 audit_log(current->audit_context, GFP_ATOMIC,
2415 AUDIT_MAC_CONFIG_CHANGE,
2416 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2417 sym_name(&policydb, SYM_BOOLS, i),
2418 !!values[i],
2419 policydb.bool_val_to_struct[i]->state,
2420 audit_get_loginuid(current),
2421 audit_get_sessionid(current));
2422 }
2423 if (values[i])
2424 policydb.bool_val_to_struct[i]->state = 1;
2425 else
2426 policydb.bool_val_to_struct[i]->state = 0;
2427 }
2428
2429 for (cur = policydb.cond_list; cur; cur = cur->next) {
2430 rc = evaluate_cond_node(&policydb, cur);
2431 if (rc)
2432 goto out;
2433 }
2434
2435 seqno = ++latest_granting;
2436 rc = 0;
2437 out:
2438 write_unlock_irq(&policy_rwlock);
2439 if (!rc) {
2440 avc_ss_reset(seqno);
2441 selnl_notify_policyload(seqno);
2442 selinux_status_update_policyload(seqno);
2443 selinux_xfrm_notify_policyload();
2444 }
2445 return rc;
2446 }
2447
2448 int security_get_bool_value(int bool)
2449 {
2450 int rc;
2451 int len;
2452
2453 read_lock(&policy_rwlock);
2454
2455 rc = -EFAULT;
2456 len = policydb.p_bools.nprim;
2457 if (bool >= len)
2458 goto out;
2459
2460 rc = policydb.bool_val_to_struct[bool]->state;
2461 out:
2462 read_unlock(&policy_rwlock);
2463 return rc;
2464 }
2465
2466 static int security_preserve_bools(struct policydb *p)
2467 {
2468 int rc, nbools = 0, *bvalues = NULL, i;
2469 char **bnames = NULL;
2470 struct cond_bool_datum *booldatum;
2471 struct cond_node *cur;
2472
2473 rc = security_get_bools(&nbools, &bnames, &bvalues);
2474 if (rc)
2475 goto out;
2476 for (i = 0; i < nbools; i++) {
2477 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2478 if (booldatum)
2479 booldatum->state = bvalues[i];
2480 }
2481 for (cur = p->cond_list; cur; cur = cur->next) {
2482 rc = evaluate_cond_node(p, cur);
2483 if (rc)
2484 goto out;
2485 }
2486
2487 out:
2488 if (bnames) {
2489 for (i = 0; i < nbools; i++)
2490 kfree(bnames[i]);
2491 }
2492 kfree(bnames);
2493 kfree(bvalues);
2494 return rc;
2495 }
2496
2497 /*
2498 * security_sid_mls_copy() - computes a new sid based on the given
2499 * sid and the mls portion of mls_sid.
2500 */
2501 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2502 {
2503 struct context *context1;
2504 struct context *context2;
2505 struct context newcon;
2506 char *s;
2507 u32 len;
2508 int rc;
2509
2510 rc = 0;
2511 if (!ss_initialized || !policydb.mls_enabled) {
2512 *new_sid = sid;
2513 goto out;
2514 }
2515
2516 context_init(&newcon);
2517
2518 read_lock(&policy_rwlock);
2519
2520 rc = -EINVAL;
2521 context1 = sidtab_search(&sidtab, sid);
2522 if (!context1) {
2523 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2524 __func__, sid);
2525 goto out_unlock;
2526 }
2527
2528 rc = -EINVAL;
2529 context2 = sidtab_search(&sidtab, mls_sid);
2530 if (!context2) {
2531 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2532 __func__, mls_sid);
2533 goto out_unlock;
2534 }
2535
2536 newcon.user = context1->user;
2537 newcon.role = context1->role;
2538 newcon.type = context1->type;
2539 rc = mls_context_cpy(&newcon, context2);
2540 if (rc)
2541 goto out_unlock;
2542
2543 /* Check the validity of the new context. */
2544 if (!policydb_context_isvalid(&policydb, &newcon)) {
2545 rc = convert_context_handle_invalid_context(&newcon);
2546 if (rc) {
2547 if (!context_struct_to_string(&newcon, &s, &len)) {
2548 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2549 "security_sid_mls_copy: invalid context %s", s);
2550 kfree(s);
2551 }
2552 goto out_unlock;
2553 }
2554 }
2555
2556 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2557 out_unlock:
2558 read_unlock(&policy_rwlock);
2559 context_destroy(&newcon);
2560 out:
2561 return rc;
2562 }
2563
2564 /**
2565 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2566 * @nlbl_sid: NetLabel SID
2567 * @nlbl_type: NetLabel labeling protocol type
2568 * @xfrm_sid: XFRM SID
2569 *
2570 * Description:
2571 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2572 * resolved into a single SID it is returned via @peer_sid and the function
2573 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2574 * returns a negative value. A table summarizing the behavior is below:
2575 *
2576 * | function return | @sid
2577 * ------------------------------+-----------------+-----------------
2578 * no peer labels | 0 | SECSID_NULL
2579 * single peer label | 0 | <peer_label>
2580 * multiple, consistent labels | 0 | <peer_label>
2581 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2582 *
2583 */
2584 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2585 u32 xfrm_sid,
2586 u32 *peer_sid)
2587 {
2588 int rc;
2589 struct context *nlbl_ctx;
2590 struct context *xfrm_ctx;
2591
2592 *peer_sid = SECSID_NULL;
2593
2594 /* handle the common (which also happens to be the set of easy) cases
2595 * right away, these two if statements catch everything involving a
2596 * single or absent peer SID/label */
2597 if (xfrm_sid == SECSID_NULL) {
2598 *peer_sid = nlbl_sid;
2599 return 0;
2600 }
2601 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2602 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2603 * is present */
2604 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2605 *peer_sid = xfrm_sid;
2606 return 0;
2607 }
2608
2609 /* we don't need to check ss_initialized here since the only way both
2610 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2611 * security server was initialized and ss_initialized was true */
2612 if (!policydb.mls_enabled)
2613 return 0;
2614
2615 read_lock(&policy_rwlock);
2616
2617 rc = -EINVAL;
2618 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2619 if (!nlbl_ctx) {
2620 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2621 __func__, nlbl_sid);
2622 goto out;
2623 }
2624 rc = -EINVAL;
2625 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2626 if (!xfrm_ctx) {
2627 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2628 __func__, xfrm_sid);
2629 goto out;
2630 }
2631 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2632 if (rc)
2633 goto out;
2634
2635 /* at present NetLabel SIDs/labels really only carry MLS
2636 * information so if the MLS portion of the NetLabel SID
2637 * matches the MLS portion of the labeled XFRM SID/label
2638 * then pass along the XFRM SID as it is the most
2639 * expressive */
2640 *peer_sid = xfrm_sid;
2641 out:
2642 read_unlock(&policy_rwlock);
2643 return rc;
2644 }
2645
2646 static int get_classes_callback(void *k, void *d, void *args)
2647 {
2648 struct class_datum *datum = d;
2649 char *name = k, **classes = args;
2650 int value = datum->value - 1;
2651
2652 classes[value] = kstrdup(name, GFP_ATOMIC);
2653 if (!classes[value])
2654 return -ENOMEM;
2655
2656 return 0;
2657 }
2658
2659 int security_get_classes(char ***classes, int *nclasses)
2660 {
2661 int rc;
2662
2663 read_lock(&policy_rwlock);
2664
2665 rc = -ENOMEM;
2666 *nclasses = policydb.p_classes.nprim;
2667 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2668 if (!*classes)
2669 goto out;
2670
2671 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2672 *classes);
2673 if (rc) {
2674 int i;
2675 for (i = 0; i < *nclasses; i++)
2676 kfree((*classes)[i]);
2677 kfree(*classes);
2678 }
2679
2680 out:
2681 read_unlock(&policy_rwlock);
2682 return rc;
2683 }
2684
2685 static int get_permissions_callback(void *k, void *d, void *args)
2686 {
2687 struct perm_datum *datum = d;
2688 char *name = k, **perms = args;
2689 int value = datum->value - 1;
2690
2691 perms[value] = kstrdup(name, GFP_ATOMIC);
2692 if (!perms[value])
2693 return -ENOMEM;
2694
2695 return 0;
2696 }
2697
2698 int security_get_permissions(char *class, char ***perms, int *nperms)
2699 {
2700 int rc, i;
2701 struct class_datum *match;
2702
2703 read_lock(&policy_rwlock);
2704
2705 rc = -EINVAL;
2706 match = hashtab_search(policydb.p_classes.table, class);
2707 if (!match) {
2708 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2709 __func__, class);
2710 goto out;
2711 }
2712
2713 rc = -ENOMEM;
2714 *nperms = match->permissions.nprim;
2715 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2716 if (!*perms)
2717 goto out;
2718
2719 if (match->comdatum) {
2720 rc = hashtab_map(match->comdatum->permissions.table,
2721 get_permissions_callback, *perms);
2722 if (rc)
2723 goto err;
2724 }
2725
2726 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2727 *perms);
2728 if (rc)
2729 goto err;
2730
2731 out:
2732 read_unlock(&policy_rwlock);
2733 return rc;
2734
2735 err:
2736 read_unlock(&policy_rwlock);
2737 for (i = 0; i < *nperms; i++)
2738 kfree((*perms)[i]);
2739 kfree(*perms);
2740 return rc;
2741 }
2742
2743 int security_get_reject_unknown(void)
2744 {
2745 return policydb.reject_unknown;
2746 }
2747
2748 int security_get_allow_unknown(void)
2749 {
2750 return policydb.allow_unknown;
2751 }
2752
2753 /**
2754 * security_policycap_supported - Check for a specific policy capability
2755 * @req_cap: capability
2756 *
2757 * Description:
2758 * This function queries the currently loaded policy to see if it supports the
2759 * capability specified by @req_cap. Returns true (1) if the capability is
2760 * supported, false (0) if it isn't supported.
2761 *
2762 */
2763 int security_policycap_supported(unsigned int req_cap)
2764 {
2765 int rc;
2766
2767 read_lock(&policy_rwlock);
2768 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2769 read_unlock(&policy_rwlock);
2770
2771 return rc;
2772 }
2773
2774 struct selinux_audit_rule {
2775 u32 au_seqno;
2776 struct context au_ctxt;
2777 };
2778
2779 void selinux_audit_rule_free(void *vrule)
2780 {
2781 struct selinux_audit_rule *rule = vrule;
2782
2783 if (rule) {
2784 context_destroy(&rule->au_ctxt);
2785 kfree(rule);
2786 }
2787 }
2788
2789 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2790 {
2791 struct selinux_audit_rule *tmprule;
2792 struct role_datum *roledatum;
2793 struct type_datum *typedatum;
2794 struct user_datum *userdatum;
2795 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2796 int rc = 0;
2797
2798 *rule = NULL;
2799
2800 if (!ss_initialized)
2801 return -EOPNOTSUPP;
2802
2803 switch (field) {
2804 case AUDIT_SUBJ_USER:
2805 case AUDIT_SUBJ_ROLE:
2806 case AUDIT_SUBJ_TYPE:
2807 case AUDIT_OBJ_USER:
2808 case AUDIT_OBJ_ROLE:
2809 case AUDIT_OBJ_TYPE:
2810 /* only 'equals' and 'not equals' fit user, role, and type */
2811 if (op != Audit_equal && op != Audit_not_equal)
2812 return -EINVAL;
2813 break;
2814 case AUDIT_SUBJ_SEN:
2815 case AUDIT_SUBJ_CLR:
2816 case AUDIT_OBJ_LEV_LOW:
2817 case AUDIT_OBJ_LEV_HIGH:
2818 /* we do not allow a range, indicated by the presence of '-' */
2819 if (strchr(rulestr, '-'))
2820 return -EINVAL;
2821 break;
2822 default:
2823 /* only the above fields are valid */
2824 return -EINVAL;
2825 }
2826
2827 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2828 if (!tmprule)
2829 return -ENOMEM;
2830
2831 context_init(&tmprule->au_ctxt);
2832
2833 read_lock(&policy_rwlock);
2834
2835 tmprule->au_seqno = latest_granting;
2836
2837 switch (field) {
2838 case AUDIT_SUBJ_USER:
2839 case AUDIT_OBJ_USER:
2840 rc = -EINVAL;
2841 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2842 if (!userdatum)
2843 goto out;
2844 tmprule->au_ctxt.user = userdatum->value;
2845 break;
2846 case AUDIT_SUBJ_ROLE:
2847 case AUDIT_OBJ_ROLE:
2848 rc = -EINVAL;
2849 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2850 if (!roledatum)
2851 goto out;
2852 tmprule->au_ctxt.role = roledatum->value;
2853 break;
2854 case AUDIT_SUBJ_TYPE:
2855 case AUDIT_OBJ_TYPE:
2856 rc = -EINVAL;
2857 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2858 if (!typedatum)
2859 goto out;
2860 tmprule->au_ctxt.type = typedatum->value;
2861 break;
2862 case AUDIT_SUBJ_SEN:
2863 case AUDIT_SUBJ_CLR:
2864 case AUDIT_OBJ_LEV_LOW:
2865 case AUDIT_OBJ_LEV_HIGH:
2866 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2867 if (rc)
2868 goto out;
2869 break;
2870 }
2871 rc = 0;
2872 out:
2873 read_unlock(&policy_rwlock);
2874
2875 if (rc) {
2876 selinux_audit_rule_free(tmprule);
2877 tmprule = NULL;
2878 }
2879
2880 *rule = tmprule;
2881
2882 return rc;
2883 }
2884
2885 /* Check to see if the rule contains any selinux fields */
2886 int selinux_audit_rule_known(struct audit_krule *rule)
2887 {
2888 int i;
2889
2890 for (i = 0; i < rule->field_count; i++) {
2891 struct audit_field *f = &rule->fields[i];
2892 switch (f->type) {
2893 case AUDIT_SUBJ_USER:
2894 case AUDIT_SUBJ_ROLE:
2895 case AUDIT_SUBJ_TYPE:
2896 case AUDIT_SUBJ_SEN:
2897 case AUDIT_SUBJ_CLR:
2898 case AUDIT_OBJ_USER:
2899 case AUDIT_OBJ_ROLE:
2900 case AUDIT_OBJ_TYPE:
2901 case AUDIT_OBJ_LEV_LOW:
2902 case AUDIT_OBJ_LEV_HIGH:
2903 return 1;
2904 }
2905 }
2906
2907 return 0;
2908 }
2909
2910 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2911 struct audit_context *actx)
2912 {
2913 struct context *ctxt;
2914 struct mls_level *level;
2915 struct selinux_audit_rule *rule = vrule;
2916 int match = 0;
2917
2918 if (!rule) {
2919 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2920 "selinux_audit_rule_match: missing rule\n");
2921 return -ENOENT;
2922 }
2923
2924 read_lock(&policy_rwlock);
2925
2926 if (rule->au_seqno < latest_granting) {
2927 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2928 "selinux_audit_rule_match: stale rule\n");
2929 match = -ESTALE;
2930 goto out;
2931 }
2932
2933 ctxt = sidtab_search(&sidtab, sid);
2934 if (!ctxt) {
2935 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2936 "selinux_audit_rule_match: unrecognized SID %d\n",
2937 sid);
2938 match = -ENOENT;
2939 goto out;
2940 }
2941
2942 /* a field/op pair that is not caught here will simply fall through
2943 without a match */
2944 switch (field) {
2945 case AUDIT_SUBJ_USER:
2946 case AUDIT_OBJ_USER:
2947 switch (op) {
2948 case Audit_equal:
2949 match = (ctxt->user == rule->au_ctxt.user);
2950 break;
2951 case Audit_not_equal:
2952 match = (ctxt->user != rule->au_ctxt.user);
2953 break;
2954 }
2955 break;
2956 case AUDIT_SUBJ_ROLE:
2957 case AUDIT_OBJ_ROLE:
2958 switch (op) {
2959 case Audit_equal:
2960 match = (ctxt->role == rule->au_ctxt.role);
2961 break;
2962 case Audit_not_equal:
2963 match = (ctxt->role != rule->au_ctxt.role);
2964 break;
2965 }
2966 break;
2967 case AUDIT_SUBJ_TYPE:
2968 case AUDIT_OBJ_TYPE:
2969 switch (op) {
2970 case Audit_equal:
2971 match = (ctxt->type == rule->au_ctxt.type);
2972 break;
2973 case Audit_not_equal:
2974 match = (ctxt->type != rule->au_ctxt.type);
2975 break;
2976 }
2977 break;
2978 case AUDIT_SUBJ_SEN:
2979 case AUDIT_SUBJ_CLR:
2980 case AUDIT_OBJ_LEV_LOW:
2981 case AUDIT_OBJ_LEV_HIGH:
2982 level = ((field == AUDIT_SUBJ_SEN ||
2983 field == AUDIT_OBJ_LEV_LOW) ?
2984 &ctxt->range.level[0] : &ctxt->range.level[1]);
2985 switch (op) {
2986 case Audit_equal:
2987 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2988 level);
2989 break;
2990 case Audit_not_equal:
2991 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2992 level);
2993 break;
2994 case Audit_lt:
2995 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2996 level) &&
2997 !mls_level_eq(&rule->au_ctxt.range.level[0],
2998 level));
2999 break;
3000 case Audit_le:
3001 match = mls_level_dom(&rule->au_ctxt.range.level[0],
3002 level);
3003 break;
3004 case Audit_gt:
3005 match = (mls_level_dom(level,
3006 &rule->au_ctxt.range.level[0]) &&
3007 !mls_level_eq(level,
3008 &rule->au_ctxt.range.level[0]));
3009 break;
3010 case Audit_ge:
3011 match = mls_level_dom(level,
3012 &rule->au_ctxt.range.level[0]);
3013 break;
3014 }
3015 }
3016
3017 out:
3018 read_unlock(&policy_rwlock);
3019 return match;
3020 }
3021
3022 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3023
3024 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3025 u16 class, u32 perms, u32 *retained)
3026 {
3027 int err = 0;
3028
3029 if (event == AVC_CALLBACK_RESET && aurule_callback)
3030 err = aurule_callback();
3031 return err;
3032 }
3033
3034 static int __init aurule_init(void)
3035 {
3036 int err;
3037
3038 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3039 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3040 if (err)
3041 panic("avc_add_callback() failed, error %d\n", err);
3042
3043 return err;
3044 }
3045 __initcall(aurule_init);
3046
3047 #ifdef CONFIG_NETLABEL
3048 /**
3049 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3050 * @secattr: the NetLabel packet security attributes
3051 * @sid: the SELinux SID
3052 *
3053 * Description:
3054 * Attempt to cache the context in @ctx, which was derived from the packet in
3055 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3056 * already been initialized.
3057 *
3058 */
3059 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3060 u32 sid)
3061 {
3062 u32 *sid_cache;
3063
3064 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3065 if (sid_cache == NULL)
3066 return;
3067 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3068 if (secattr->cache == NULL) {
3069 kfree(sid_cache);
3070 return;
3071 }
3072
3073 *sid_cache = sid;
3074 secattr->cache->free = kfree;
3075 secattr->cache->data = sid_cache;
3076 secattr->flags |= NETLBL_SECATTR_CACHE;
3077 }
3078
3079 /**
3080 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3081 * @secattr: the NetLabel packet security attributes
3082 * @sid: the SELinux SID
3083 *
3084 * Description:
3085 * Convert the given NetLabel security attributes in @secattr into a
3086 * SELinux SID. If the @secattr field does not contain a full SELinux
3087 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3088 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3089 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3090 * conversion for future lookups. Returns zero on success, negative values on
3091 * failure.
3092 *
3093 */
3094 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3095 u32 *sid)
3096 {
3097 int rc;
3098 struct context *ctx;
3099 struct context ctx_new;
3100
3101 if (!ss_initialized) {
3102 *sid = SECSID_NULL;
3103 return 0;
3104 }
3105
3106 read_lock(&policy_rwlock);
3107
3108 if (secattr->flags & NETLBL_SECATTR_CACHE)
3109 *sid = *(u32 *)secattr->cache->data;
3110 else if (secattr->flags & NETLBL_SECATTR_SECID)
3111 *sid = secattr->attr.secid;
3112 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3113 rc = -EIDRM;
3114 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3115 if (ctx == NULL)
3116 goto out;
3117
3118 context_init(&ctx_new);
3119 ctx_new.user = ctx->user;
3120 ctx_new.role = ctx->role;
3121 ctx_new.type = ctx->type;
3122 mls_import_netlbl_lvl(&ctx_new, secattr);
3123 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3124 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3125 secattr->attr.mls.cat);
3126 if (rc)
3127 goto out;
3128 memcpy(&ctx_new.range.level[1].cat,
3129 &ctx_new.range.level[0].cat,
3130 sizeof(ctx_new.range.level[0].cat));
3131 }
3132 rc = -EIDRM;
3133 if (!mls_context_isvalid(&policydb, &ctx_new))
3134 goto out_free;
3135
3136 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3137 if (rc)
3138 goto out_free;
3139
3140 security_netlbl_cache_add(secattr, *sid);
3141
3142 ebitmap_destroy(&ctx_new.range.level[0].cat);
3143 } else
3144 *sid = SECSID_NULL;
3145
3146 read_unlock(&policy_rwlock);
3147 return 0;
3148 out_free:
3149 ebitmap_destroy(&ctx_new.range.level[0].cat);
3150 out:
3151 read_unlock(&policy_rwlock);
3152 return rc;
3153 }
3154
3155 /**
3156 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3157 * @sid: the SELinux SID
3158 * @secattr: the NetLabel packet security attributes
3159 *
3160 * Description:
3161 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3162 * Returns zero on success, negative values on failure.
3163 *
3164 */
3165 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3166 {
3167 int rc;
3168 struct context *ctx;
3169
3170 if (!ss_initialized)
3171 return 0;
3172
3173 read_lock(&policy_rwlock);
3174
3175 rc = -ENOENT;
3176 ctx = sidtab_search(&sidtab, sid);
3177 if (ctx == NULL)
3178 goto out;
3179
3180 rc = -ENOMEM;
3181 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3182 GFP_ATOMIC);
3183 if (secattr->domain == NULL)
3184 goto out;
3185
3186 secattr->attr.secid = sid;
3187 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3188 mls_export_netlbl_lvl(ctx, secattr);
3189 rc = mls_export_netlbl_cat(ctx, secattr);
3190 out:
3191 read_unlock(&policy_rwlock);
3192 return rc;
3193 }
3194 #endif /* CONFIG_NETLABEL */
3195
3196 /**
3197 * security_read_policy - read the policy.
3198 * @data: binary policy data
3199 * @len: length of data in bytes
3200 *
3201 */
3202 int security_read_policy(void **data, size_t *len)
3203 {
3204 int rc;
3205 struct policy_file fp;
3206
3207 if (!ss_initialized)
3208 return -EINVAL;
3209
3210 *len = security_policydb_len();
3211
3212 *data = vmalloc_user(*len);
3213 if (!*data)
3214 return -ENOMEM;
3215
3216 fp.data = *data;
3217 fp.len = *len;
3218
3219 read_lock(&policy_rwlock);
3220 rc = policydb_write(&policydb, &fp);
3221 read_unlock(&policy_rwlock);
3222
3223 if (rc)
3224 return rc;
3225
3226 *len = (unsigned long)fp.data - (unsigned long)*data;
3227 return 0;
3228
3229 }
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