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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.moore@hp.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 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
26 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
27 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
28 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
29 * This program is free software; you can redistribute it and/or modify
30 * it under the terms of the GNU General Public License as published by
31 * the Free Software Foundation, version 2.
32 */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/string.h>
36 #include <linux/spinlock.h>
37 #include <linux/rcupdate.h>
38 #include <linux/errno.h>
39 #include <linux/in.h>
40 #include <linux/sched.h>
41 #include <linux/audit.h>
42 #include <linux/mutex.h>
43 #include <linux/selinux.h>
44 #include <net/netlabel.h>
45
46 #include "flask.h"
47 #include "avc.h"
48 #include "avc_ss.h"
49 #include "security.h"
50 #include "context.h"
51 #include "policydb.h"
52 #include "sidtab.h"
53 #include "services.h"
54 #include "conditional.h"
55 #include "mls.h"
56 #include "objsec.h"
57 #include "netlabel.h"
58 #include "xfrm.h"
59 #include "ebitmap.h"
60 #include "audit.h"
61
62 extern void selnl_notify_policyload(u32 seqno);
63 unsigned int policydb_loaded_version;
64
65 int selinux_policycap_netpeer;
66 int selinux_policycap_openperm;
67
68 /*
69 * This is declared in avc.c
70 */
71 extern const struct selinux_class_perm selinux_class_perm;
72
73 static DEFINE_RWLOCK(policy_rwlock);
74 #define POLICY_RDLOCK read_lock(&policy_rwlock)
75 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
76 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
77 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
78
79 static DEFINE_MUTEX(load_mutex);
80 #define LOAD_LOCK mutex_lock(&load_mutex)
81 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
82
83 static struct sidtab sidtab;
84 struct policydb policydb;
85 int ss_initialized;
86
87 /*
88 * The largest sequence number that has been used when
89 * providing an access decision to the access vector cache.
90 * The sequence number only changes when a policy change
91 * occurs.
92 */
93 static u32 latest_granting;
94
95 /* Forward declaration. */
96 static int context_struct_to_string(struct context *context, char **scontext,
97 u32 *scontext_len);
98
99 /*
100 * Return the boolean value of a constraint expression
101 * when it is applied to the specified source and target
102 * security contexts.
103 *
104 * xcontext is a special beast... It is used by the validatetrans rules
105 * only. For these rules, scontext is the context before the transition,
106 * tcontext is the context after the transition, and xcontext is the context
107 * of the process performing the transition. All other callers of
108 * constraint_expr_eval should pass in NULL for xcontext.
109 */
110 static int constraint_expr_eval(struct context *scontext,
111 struct context *tcontext,
112 struct context *xcontext,
113 struct constraint_expr *cexpr)
114 {
115 u32 val1, val2;
116 struct context *c;
117 struct role_datum *r1, *r2;
118 struct mls_level *l1, *l2;
119 struct constraint_expr *e;
120 int s[CEXPR_MAXDEPTH];
121 int sp = -1;
122
123 for (e = cexpr; e; e = e->next) {
124 switch (e->expr_type) {
125 case CEXPR_NOT:
126 BUG_ON(sp < 0);
127 s[sp] = !s[sp];
128 break;
129 case CEXPR_AND:
130 BUG_ON(sp < 1);
131 sp--;
132 s[sp] &= s[sp+1];
133 break;
134 case CEXPR_OR:
135 BUG_ON(sp < 1);
136 sp--;
137 s[sp] |= s[sp+1];
138 break;
139 case CEXPR_ATTR:
140 if (sp == (CEXPR_MAXDEPTH-1))
141 return 0;
142 switch (e->attr) {
143 case CEXPR_USER:
144 val1 = scontext->user;
145 val2 = tcontext->user;
146 break;
147 case CEXPR_TYPE:
148 val1 = scontext->type;
149 val2 = tcontext->type;
150 break;
151 case CEXPR_ROLE:
152 val1 = scontext->role;
153 val2 = tcontext->role;
154 r1 = policydb.role_val_to_struct[val1 - 1];
155 r2 = policydb.role_val_to_struct[val2 - 1];
156 switch (e->op) {
157 case CEXPR_DOM:
158 s[++sp] = ebitmap_get_bit(&r1->dominates,
159 val2 - 1);
160 continue;
161 case CEXPR_DOMBY:
162 s[++sp] = ebitmap_get_bit(&r2->dominates,
163 val1 - 1);
164 continue;
165 case CEXPR_INCOMP:
166 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
167 val2 - 1) &&
168 !ebitmap_get_bit(&r2->dominates,
169 val1 - 1));
170 continue;
171 default:
172 break;
173 }
174 break;
175 case CEXPR_L1L2:
176 l1 = &(scontext->range.level[0]);
177 l2 = &(tcontext->range.level[0]);
178 goto mls_ops;
179 case CEXPR_L1H2:
180 l1 = &(scontext->range.level[0]);
181 l2 = &(tcontext->range.level[1]);
182 goto mls_ops;
183 case CEXPR_H1L2:
184 l1 = &(scontext->range.level[1]);
185 l2 = &(tcontext->range.level[0]);
186 goto mls_ops;
187 case CEXPR_H1H2:
188 l1 = &(scontext->range.level[1]);
189 l2 = &(tcontext->range.level[1]);
190 goto mls_ops;
191 case CEXPR_L1H1:
192 l1 = &(scontext->range.level[0]);
193 l2 = &(scontext->range.level[1]);
194 goto mls_ops;
195 case CEXPR_L2H2:
196 l1 = &(tcontext->range.level[0]);
197 l2 = &(tcontext->range.level[1]);
198 goto mls_ops;
199 mls_ops:
200 switch (e->op) {
201 case CEXPR_EQ:
202 s[++sp] = mls_level_eq(l1, l2);
203 continue;
204 case CEXPR_NEQ:
205 s[++sp] = !mls_level_eq(l1, l2);
206 continue;
207 case CEXPR_DOM:
208 s[++sp] = mls_level_dom(l1, l2);
209 continue;
210 case CEXPR_DOMBY:
211 s[++sp] = mls_level_dom(l2, l1);
212 continue;
213 case CEXPR_INCOMP:
214 s[++sp] = mls_level_incomp(l2, l1);
215 continue;
216 default:
217 BUG();
218 return 0;
219 }
220 break;
221 default:
222 BUG();
223 return 0;
224 }
225
226 switch (e->op) {
227 case CEXPR_EQ:
228 s[++sp] = (val1 == val2);
229 break;
230 case CEXPR_NEQ:
231 s[++sp] = (val1 != val2);
232 break;
233 default:
234 BUG();
235 return 0;
236 }
237 break;
238 case CEXPR_NAMES:
239 if (sp == (CEXPR_MAXDEPTH-1))
240 return 0;
241 c = scontext;
242 if (e->attr & CEXPR_TARGET)
243 c = tcontext;
244 else if (e->attr & CEXPR_XTARGET) {
245 c = xcontext;
246 if (!c) {
247 BUG();
248 return 0;
249 }
250 }
251 if (e->attr & CEXPR_USER)
252 val1 = c->user;
253 else if (e->attr & CEXPR_ROLE)
254 val1 = c->role;
255 else if (e->attr & CEXPR_TYPE)
256 val1 = c->type;
257 else {
258 BUG();
259 return 0;
260 }
261
262 switch (e->op) {
263 case CEXPR_EQ:
264 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
265 break;
266 case CEXPR_NEQ:
267 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
268 break;
269 default:
270 BUG();
271 return 0;
272 }
273 break;
274 default:
275 BUG();
276 return 0;
277 }
278 }
279
280 BUG_ON(sp != 0);
281 return s[0];
282 }
283
284 /*
285 * Compute access vectors based on a context structure pair for
286 * the permissions in a particular class.
287 */
288 static int context_struct_compute_av(struct context *scontext,
289 struct context *tcontext,
290 u16 tclass,
291 u32 requested,
292 struct av_decision *avd)
293 {
294 struct constraint_node *constraint;
295 struct role_allow *ra;
296 struct avtab_key avkey;
297 struct avtab_node *node;
298 struct class_datum *tclass_datum;
299 struct ebitmap *sattr, *tattr;
300 struct ebitmap_node *snode, *tnode;
301 const struct selinux_class_perm *kdefs = &selinux_class_perm;
302 unsigned int i, j;
303
304 /*
305 * Remap extended Netlink classes for old policy versions.
306 * Do this here rather than socket_type_to_security_class()
307 * in case a newer policy version is loaded, allowing sockets
308 * to remain in the correct class.
309 */
310 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
311 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
312 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
313 tclass = SECCLASS_NETLINK_SOCKET;
314
315 /*
316 * Initialize the access vectors to the default values.
317 */
318 avd->allowed = 0;
319 avd->decided = 0xffffffff;
320 avd->auditallow = 0;
321 avd->auditdeny = 0xffffffff;
322 avd->seqno = latest_granting;
323
324 /*
325 * Check for all the invalid cases.
326 * - tclass 0
327 * - tclass > policy and > kernel
328 * - tclass > policy but is a userspace class
329 * - tclass > policy but we do not allow unknowns
330 */
331 if (unlikely(!tclass))
332 goto inval_class;
333 if (unlikely(tclass > policydb.p_classes.nprim))
334 if (tclass > kdefs->cts_len ||
335 !kdefs->class_to_string[tclass - 1] ||
336 !policydb.allow_unknown)
337 goto inval_class;
338
339 /*
340 * Kernel class and we allow unknown so pad the allow decision
341 * the pad will be all 1 for unknown classes.
342 */
343 if (tclass <= kdefs->cts_len && policydb.allow_unknown)
344 avd->allowed = policydb.undefined_perms[tclass - 1];
345
346 /*
347 * Not in policy. Since decision is completed (all 1 or all 0) return.
348 */
349 if (unlikely(tclass > policydb.p_classes.nprim))
350 return 0;
351
352 tclass_datum = policydb.class_val_to_struct[tclass - 1];
353
354 /*
355 * If a specific type enforcement rule was defined for
356 * this permission check, then use it.
357 */
358 avkey.target_class = tclass;
359 avkey.specified = AVTAB_AV;
360 sattr = &policydb.type_attr_map[scontext->type - 1];
361 tattr = &policydb.type_attr_map[tcontext->type - 1];
362 ebitmap_for_each_positive_bit(sattr, snode, i) {
363 ebitmap_for_each_positive_bit(tattr, tnode, j) {
364 avkey.source_type = i + 1;
365 avkey.target_type = j + 1;
366 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
367 node != NULL;
368 node = avtab_search_node_next(node, avkey.specified)) {
369 if (node->key.specified == AVTAB_ALLOWED)
370 avd->allowed |= node->datum.data;
371 else if (node->key.specified == AVTAB_AUDITALLOW)
372 avd->auditallow |= node->datum.data;
373 else if (node->key.specified == AVTAB_AUDITDENY)
374 avd->auditdeny &= node->datum.data;
375 }
376
377 /* Check conditional av table for additional permissions */
378 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
379
380 }
381 }
382
383 /*
384 * Remove any permissions prohibited by a constraint (this includes
385 * the MLS policy).
386 */
387 constraint = tclass_datum->constraints;
388 while (constraint) {
389 if ((constraint->permissions & (avd->allowed)) &&
390 !constraint_expr_eval(scontext, tcontext, NULL,
391 constraint->expr)) {
392 avd->allowed = (avd->allowed) & ~(constraint->permissions);
393 }
394 constraint = constraint->next;
395 }
396
397 /*
398 * If checking process transition permission and the
399 * role is changing, then check the (current_role, new_role)
400 * pair.
401 */
402 if (tclass == SECCLASS_PROCESS &&
403 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
404 scontext->role != tcontext->role) {
405 for (ra = policydb.role_allow; ra; ra = ra->next) {
406 if (scontext->role == ra->role &&
407 tcontext->role == ra->new_role)
408 break;
409 }
410 if (!ra)
411 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
412 PROCESS__DYNTRANSITION);
413 }
414
415 return 0;
416
417 inval_class:
418 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n", __func__,
419 tclass);
420 return -EINVAL;
421 }
422
423 /*
424 * Given a sid find if the type has the permissive flag set
425 */
426 int security_permissive_sid(u32 sid)
427 {
428 struct context *context;
429 u32 type;
430 int rc;
431
432 POLICY_RDLOCK;
433
434 context = sidtab_search(&sidtab, sid);
435 BUG_ON(!context);
436
437 type = context->type;
438 /*
439 * we are intentionally using type here, not type-1, the 0th bit may
440 * someday indicate that we are globally setting permissive in policy.
441 */
442 rc = ebitmap_get_bit(&policydb.permissive_map, type);
443
444 POLICY_RDUNLOCK;
445 return rc;
446 }
447
448 static int security_validtrans_handle_fail(struct context *ocontext,
449 struct context *ncontext,
450 struct context *tcontext,
451 u16 tclass)
452 {
453 char *o = NULL, *n = NULL, *t = NULL;
454 u32 olen, nlen, tlen;
455
456 if (context_struct_to_string(ocontext, &o, &olen) < 0)
457 goto out;
458 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
459 goto out;
460 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
461 goto out;
462 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
463 "security_validate_transition: denied for"
464 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
465 o, n, t, policydb.p_class_val_to_name[tclass-1]);
466 out:
467 kfree(o);
468 kfree(n);
469 kfree(t);
470
471 if (!selinux_enforcing)
472 return 0;
473 return -EPERM;
474 }
475
476 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
477 u16 tclass)
478 {
479 struct context *ocontext;
480 struct context *ncontext;
481 struct context *tcontext;
482 struct class_datum *tclass_datum;
483 struct constraint_node *constraint;
484 int rc = 0;
485
486 if (!ss_initialized)
487 return 0;
488
489 POLICY_RDLOCK;
490
491 /*
492 * Remap extended Netlink classes for old policy versions.
493 * Do this here rather than socket_type_to_security_class()
494 * in case a newer policy version is loaded, allowing sockets
495 * to remain in the correct class.
496 */
497 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
498 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
499 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
500 tclass = SECCLASS_NETLINK_SOCKET;
501
502 if (!tclass || tclass > policydb.p_classes.nprim) {
503 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
504 __func__, tclass);
505 rc = -EINVAL;
506 goto out;
507 }
508 tclass_datum = policydb.class_val_to_struct[tclass - 1];
509
510 ocontext = sidtab_search(&sidtab, oldsid);
511 if (!ocontext) {
512 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
513 __func__, oldsid);
514 rc = -EINVAL;
515 goto out;
516 }
517
518 ncontext = sidtab_search(&sidtab, newsid);
519 if (!ncontext) {
520 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
521 __func__, newsid);
522 rc = -EINVAL;
523 goto out;
524 }
525
526 tcontext = sidtab_search(&sidtab, tasksid);
527 if (!tcontext) {
528 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
529 __func__, tasksid);
530 rc = -EINVAL;
531 goto out;
532 }
533
534 constraint = tclass_datum->validatetrans;
535 while (constraint) {
536 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
537 constraint->expr)) {
538 rc = security_validtrans_handle_fail(ocontext, ncontext,
539 tcontext, tclass);
540 goto out;
541 }
542 constraint = constraint->next;
543 }
544
545 out:
546 POLICY_RDUNLOCK;
547 return rc;
548 }
549
550 /**
551 * security_compute_av - Compute access vector decisions.
552 * @ssid: source security identifier
553 * @tsid: target security identifier
554 * @tclass: target security class
555 * @requested: requested permissions
556 * @avd: access vector decisions
557 *
558 * Compute a set of access vector decisions based on the
559 * SID pair (@ssid, @tsid) for the permissions in @tclass.
560 * Return -%EINVAL if any of the parameters are invalid or %0
561 * if the access vector decisions were computed successfully.
562 */
563 int security_compute_av(u32 ssid,
564 u32 tsid,
565 u16 tclass,
566 u32 requested,
567 struct av_decision *avd)
568 {
569 struct context *scontext = NULL, *tcontext = NULL;
570 int rc = 0;
571
572 if (!ss_initialized) {
573 avd->allowed = 0xffffffff;
574 avd->decided = 0xffffffff;
575 avd->auditallow = 0;
576 avd->auditdeny = 0xffffffff;
577 avd->seqno = latest_granting;
578 return 0;
579 }
580
581 POLICY_RDLOCK;
582
583 scontext = sidtab_search(&sidtab, ssid);
584 if (!scontext) {
585 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
586 __func__, ssid);
587 rc = -EINVAL;
588 goto out;
589 }
590 tcontext = sidtab_search(&sidtab, tsid);
591 if (!tcontext) {
592 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
593 __func__, tsid);
594 rc = -EINVAL;
595 goto out;
596 }
597
598 rc = context_struct_compute_av(scontext, tcontext, tclass,
599 requested, avd);
600 out:
601 POLICY_RDUNLOCK;
602 return rc;
603 }
604
605 /*
606 * Write the security context string representation of
607 * the context structure `context' into a dynamically
608 * allocated string of the correct size. Set `*scontext'
609 * to point to this string and set `*scontext_len' to
610 * the length of the string.
611 */
612 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
613 {
614 char *scontextp;
615
616 *scontext = NULL;
617 *scontext_len = 0;
618
619 if (context->len) {
620 *scontext_len = context->len;
621 *scontext = kstrdup(context->str, GFP_ATOMIC);
622 if (!(*scontext))
623 return -ENOMEM;
624 return 0;
625 }
626
627 /* Compute the size of the context. */
628 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
629 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
630 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
631 *scontext_len += mls_compute_context_len(context);
632
633 /* Allocate space for the context; caller must free this space. */
634 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
635 if (!scontextp)
636 return -ENOMEM;
637 *scontext = scontextp;
638
639 /*
640 * Copy the user name, role name and type name into the context.
641 */
642 sprintf(scontextp, "%s:%s:%s",
643 policydb.p_user_val_to_name[context->user - 1],
644 policydb.p_role_val_to_name[context->role - 1],
645 policydb.p_type_val_to_name[context->type - 1]);
646 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
647 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
648 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
649
650 mls_sid_to_context(context, &scontextp);
651
652 *scontextp = 0;
653
654 return 0;
655 }
656
657 #include "initial_sid_to_string.h"
658
659 const char *security_get_initial_sid_context(u32 sid)
660 {
661 if (unlikely(sid > SECINITSID_NUM))
662 return NULL;
663 return initial_sid_to_string[sid];
664 }
665
666 static int security_sid_to_context_core(u32 sid, char **scontext,
667 u32 *scontext_len, int force)
668 {
669 struct context *context;
670 int rc = 0;
671
672 *scontext = NULL;
673 *scontext_len = 0;
674
675 if (!ss_initialized) {
676 if (sid <= SECINITSID_NUM) {
677 char *scontextp;
678
679 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
680 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
681 if (!scontextp) {
682 rc = -ENOMEM;
683 goto out;
684 }
685 strcpy(scontextp, initial_sid_to_string[sid]);
686 *scontext = scontextp;
687 goto out;
688 }
689 printk(KERN_ERR "SELinux: %s: called before initial "
690 "load_policy on unknown SID %d\n", __func__, sid);
691 rc = -EINVAL;
692 goto out;
693 }
694 POLICY_RDLOCK;
695 if (force)
696 context = sidtab_search_force(&sidtab, sid);
697 else
698 context = sidtab_search(&sidtab, sid);
699 if (!context) {
700 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
701 __func__, sid);
702 rc = -EINVAL;
703 goto out_unlock;
704 }
705 rc = context_struct_to_string(context, scontext, scontext_len);
706 out_unlock:
707 POLICY_RDUNLOCK;
708 out:
709 return rc;
710
711 }
712
713 /**
714 * security_sid_to_context - Obtain a context for a given SID.
715 * @sid: security identifier, SID
716 * @scontext: security context
717 * @scontext_len: length in bytes
718 *
719 * Write the string representation of the context associated with @sid
720 * into a dynamically allocated string of the correct size. Set @scontext
721 * to point to this string and set @scontext_len to the length of the string.
722 */
723 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
724 {
725 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
726 }
727
728 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
729 {
730 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
731 }
732
733 static int string_to_context_struct(struct policydb *pol,
734 struct sidtab *sidtabp,
735 const char *scontext,
736 u32 scontext_len,
737 struct context *ctx,
738 u32 def_sid,
739 gfp_t gfp_flags)
740 {
741 char *scontext2 = NULL;
742 struct role_datum *role;
743 struct type_datum *typdatum;
744 struct user_datum *usrdatum;
745 char *scontextp, *p, oldc;
746 int rc = 0;
747
748 context_init(ctx);
749
750 /* Copy the string so that we can modify the copy as we parse it. */
751 scontext2 = kmalloc(scontext_len+1, gfp_flags);
752 if (!scontext2) {
753 rc = -ENOMEM;
754 goto out;
755 }
756 memcpy(scontext2, scontext, scontext_len);
757 scontext2[scontext_len] = 0;
758
759 /* Parse the security context. */
760
761 rc = -EINVAL;
762 scontextp = (char *) scontext2;
763
764 /* Extract the user. */
765 p = scontextp;
766 while (*p && *p != ':')
767 p++;
768
769 if (*p == 0)
770 goto out;
771
772 *p++ = 0;
773
774 usrdatum = hashtab_search(pol->p_users.table, scontextp);
775 if (!usrdatum)
776 goto out;
777
778 ctx->user = usrdatum->value;
779
780 /* Extract role. */
781 scontextp = p;
782 while (*p && *p != ':')
783 p++;
784
785 if (*p == 0)
786 goto out;
787
788 *p++ = 0;
789
790 role = hashtab_search(pol->p_roles.table, scontextp);
791 if (!role)
792 goto out;
793 ctx->role = role->value;
794
795 /* Extract type. */
796 scontextp = p;
797 while (*p && *p != ':')
798 p++;
799 oldc = *p;
800 *p++ = 0;
801
802 typdatum = hashtab_search(pol->p_types.table, scontextp);
803 if (!typdatum)
804 goto out;
805
806 ctx->type = typdatum->value;
807
808 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
809 if (rc)
810 goto out;
811
812 if ((p - scontext2) < scontext_len) {
813 rc = -EINVAL;
814 goto out;
815 }
816
817 /* Check the validity of the new context. */
818 if (!policydb_context_isvalid(pol, ctx)) {
819 rc = -EINVAL;
820 context_destroy(ctx);
821 goto out;
822 }
823 rc = 0;
824 out:
825 kfree(scontext2);
826 return rc;
827 }
828
829 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
830 u32 *sid, u32 def_sid, gfp_t gfp_flags,
831 int force)
832 {
833 struct context context;
834 int rc = 0;
835
836 if (!ss_initialized) {
837 int i;
838
839 for (i = 1; i < SECINITSID_NUM; i++) {
840 if (!strcmp(initial_sid_to_string[i], scontext)) {
841 *sid = i;
842 goto out;
843 }
844 }
845 *sid = SECINITSID_KERNEL;
846 goto out;
847 }
848 *sid = SECSID_NULL;
849
850 POLICY_RDLOCK;
851 rc = string_to_context_struct(&policydb, &sidtab,
852 scontext, scontext_len,
853 &context, def_sid, gfp_flags);
854 if (rc == -EINVAL && force) {
855 context.str = kmalloc(scontext_len+1, gfp_flags);
856 if (!context.str) {
857 rc = -ENOMEM;
858 goto out;
859 }
860 memcpy(context.str, scontext, scontext_len);
861 context.str[scontext_len] = 0;
862 context.len = scontext_len;
863 } else if (rc)
864 goto out;
865 rc = sidtab_context_to_sid(&sidtab, &context, sid);
866 if (rc)
867 context_destroy(&context);
868 out:
869 POLICY_RDUNLOCK;
870 return rc;
871 }
872
873 /**
874 * security_context_to_sid - Obtain a SID for a given security context.
875 * @scontext: security context
876 * @scontext_len: length in bytes
877 * @sid: security identifier, SID
878 *
879 * Obtains a SID associated with the security context that
880 * has the string representation specified by @scontext.
881 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
882 * memory is available, or 0 on success.
883 */
884 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
885 {
886 return security_context_to_sid_core(scontext, scontext_len,
887 sid, SECSID_NULL, GFP_KERNEL, 0);
888 }
889
890 /**
891 * security_context_to_sid_default - Obtain a SID for a given security context,
892 * falling back to specified default if needed.
893 *
894 * @scontext: security context
895 * @scontext_len: length in bytes
896 * @sid: security identifier, SID
897 * @def_sid: default SID to assign on error
898 *
899 * Obtains a SID associated with the security context that
900 * has the string representation specified by @scontext.
901 * The default SID is passed to the MLS layer to be used to allow
902 * kernel labeling of the MLS field if the MLS field is not present
903 * (for upgrading to MLS without full relabel).
904 * Implicitly forces adding of the context even if it cannot be mapped yet.
905 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
906 * memory is available, or 0 on success.
907 */
908 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
909 u32 *sid, u32 def_sid, gfp_t gfp_flags)
910 {
911 return security_context_to_sid_core(scontext, scontext_len,
912 sid, def_sid, gfp_flags, 1);
913 }
914
915 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
916 u32 *sid)
917 {
918 return security_context_to_sid_core(scontext, scontext_len,
919 sid, SECSID_NULL, GFP_KERNEL, 1);
920 }
921
922 static int compute_sid_handle_invalid_context(
923 struct context *scontext,
924 struct context *tcontext,
925 u16 tclass,
926 struct context *newcontext)
927 {
928 char *s = NULL, *t = NULL, *n = NULL;
929 u32 slen, tlen, nlen;
930
931 if (context_struct_to_string(scontext, &s, &slen) < 0)
932 goto out;
933 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
934 goto out;
935 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
936 goto out;
937 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
938 "security_compute_sid: invalid context %s"
939 " for scontext=%s"
940 " tcontext=%s"
941 " tclass=%s",
942 n, s, t, policydb.p_class_val_to_name[tclass-1]);
943 out:
944 kfree(s);
945 kfree(t);
946 kfree(n);
947 if (!selinux_enforcing)
948 return 0;
949 return -EACCES;
950 }
951
952 static int security_compute_sid(u32 ssid,
953 u32 tsid,
954 u16 tclass,
955 u32 specified,
956 u32 *out_sid)
957 {
958 struct context *scontext = NULL, *tcontext = NULL, newcontext;
959 struct role_trans *roletr = NULL;
960 struct avtab_key avkey;
961 struct avtab_datum *avdatum;
962 struct avtab_node *node;
963 int rc = 0;
964
965 if (!ss_initialized) {
966 switch (tclass) {
967 case SECCLASS_PROCESS:
968 *out_sid = ssid;
969 break;
970 default:
971 *out_sid = tsid;
972 break;
973 }
974 goto out;
975 }
976
977 context_init(&newcontext);
978
979 POLICY_RDLOCK;
980
981 scontext = sidtab_search(&sidtab, ssid);
982 if (!scontext) {
983 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
984 __func__, ssid);
985 rc = -EINVAL;
986 goto out_unlock;
987 }
988 tcontext = sidtab_search(&sidtab, tsid);
989 if (!tcontext) {
990 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
991 __func__, tsid);
992 rc = -EINVAL;
993 goto out_unlock;
994 }
995
996 /* Set the user identity. */
997 switch (specified) {
998 case AVTAB_TRANSITION:
999 case AVTAB_CHANGE:
1000 /* Use the process user identity. */
1001 newcontext.user = scontext->user;
1002 break;
1003 case AVTAB_MEMBER:
1004 /* Use the related object owner. */
1005 newcontext.user = tcontext->user;
1006 break;
1007 }
1008
1009 /* Set the role and type to default values. */
1010 switch (tclass) {
1011 case SECCLASS_PROCESS:
1012 /* Use the current role and type of process. */
1013 newcontext.role = scontext->role;
1014 newcontext.type = scontext->type;
1015 break;
1016 default:
1017 /* Use the well-defined object role. */
1018 newcontext.role = OBJECT_R_VAL;
1019 /* Use the type of the related object. */
1020 newcontext.type = tcontext->type;
1021 }
1022
1023 /* Look for a type transition/member/change rule. */
1024 avkey.source_type = scontext->type;
1025 avkey.target_type = tcontext->type;
1026 avkey.target_class = tclass;
1027 avkey.specified = specified;
1028 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1029
1030 /* If no permanent rule, also check for enabled conditional rules */
1031 if (!avdatum) {
1032 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1033 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
1034 if (node->key.specified & AVTAB_ENABLED) {
1035 avdatum = &node->datum;
1036 break;
1037 }
1038 }
1039 }
1040
1041 if (avdatum) {
1042 /* Use the type from the type transition/member/change rule. */
1043 newcontext.type = avdatum->data;
1044 }
1045
1046 /* Check for class-specific changes. */
1047 switch (tclass) {
1048 case SECCLASS_PROCESS:
1049 if (specified & AVTAB_TRANSITION) {
1050 /* Look for a role transition rule. */
1051 for (roletr = policydb.role_tr; roletr;
1052 roletr = roletr->next) {
1053 if (roletr->role == scontext->role &&
1054 roletr->type == tcontext->type) {
1055 /* Use the role transition rule. */
1056 newcontext.role = roletr->new_role;
1057 break;
1058 }
1059 }
1060 }
1061 break;
1062 default:
1063 break;
1064 }
1065
1066 /* Set the MLS attributes.
1067 This is done last because it may allocate memory. */
1068 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1069 if (rc)
1070 goto out_unlock;
1071
1072 /* Check the validity of the context. */
1073 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1074 rc = compute_sid_handle_invalid_context(scontext,
1075 tcontext,
1076 tclass,
1077 &newcontext);
1078 if (rc)
1079 goto out_unlock;
1080 }
1081 /* Obtain the sid for the context. */
1082 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1083 out_unlock:
1084 POLICY_RDUNLOCK;
1085 context_destroy(&newcontext);
1086 out:
1087 return rc;
1088 }
1089
1090 /**
1091 * security_transition_sid - Compute the SID for a new subject/object.
1092 * @ssid: source security identifier
1093 * @tsid: target security identifier
1094 * @tclass: target security class
1095 * @out_sid: security identifier for new subject/object
1096 *
1097 * Compute a SID to use for labeling a new subject or object in the
1098 * class @tclass based on a SID pair (@ssid, @tsid).
1099 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1100 * if insufficient memory is available, or %0 if the new SID was
1101 * computed successfully.
1102 */
1103 int security_transition_sid(u32 ssid,
1104 u32 tsid,
1105 u16 tclass,
1106 u32 *out_sid)
1107 {
1108 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1109 }
1110
1111 /**
1112 * security_member_sid - Compute the SID for member selection.
1113 * @ssid: source security identifier
1114 * @tsid: target security identifier
1115 * @tclass: target security class
1116 * @out_sid: security identifier for selected member
1117 *
1118 * Compute a SID to use when selecting a member of a polyinstantiated
1119 * object of class @tclass based on a SID pair (@ssid, @tsid).
1120 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1121 * if insufficient memory is available, or %0 if the SID was
1122 * computed successfully.
1123 */
1124 int security_member_sid(u32 ssid,
1125 u32 tsid,
1126 u16 tclass,
1127 u32 *out_sid)
1128 {
1129 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1130 }
1131
1132 /**
1133 * security_change_sid - Compute the SID for object relabeling.
1134 * @ssid: source security identifier
1135 * @tsid: target security identifier
1136 * @tclass: target security class
1137 * @out_sid: security identifier for selected member
1138 *
1139 * Compute a SID to use for relabeling an object of class @tclass
1140 * based on a SID pair (@ssid, @tsid).
1141 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1142 * if insufficient memory is available, or %0 if the SID was
1143 * computed successfully.
1144 */
1145 int security_change_sid(u32 ssid,
1146 u32 tsid,
1147 u16 tclass,
1148 u32 *out_sid)
1149 {
1150 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1151 }
1152
1153 /*
1154 * Verify that each kernel class that is defined in the
1155 * policy is correct
1156 */
1157 static int validate_classes(struct policydb *p)
1158 {
1159 int i, j;
1160 struct class_datum *cladatum;
1161 struct perm_datum *perdatum;
1162 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1163 u16 class_val;
1164 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1165 const char *def_class, *def_perm, *pol_class;
1166 struct symtab *perms;
1167
1168 if (p->allow_unknown) {
1169 u32 num_classes = kdefs->cts_len;
1170 p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1171 if (!p->undefined_perms)
1172 return -ENOMEM;
1173 }
1174
1175 for (i = 1; i < kdefs->cts_len; i++) {
1176 def_class = kdefs->class_to_string[i];
1177 if (!def_class)
1178 continue;
1179 if (i > p->p_classes.nprim) {
1180 printk(KERN_INFO
1181 "SELinux: class %s not defined in policy\n",
1182 def_class);
1183 if (p->reject_unknown)
1184 return -EINVAL;
1185 if (p->allow_unknown)
1186 p->undefined_perms[i-1] = ~0U;
1187 continue;
1188 }
1189 pol_class = p->p_class_val_to_name[i-1];
1190 if (strcmp(pol_class, def_class)) {
1191 printk(KERN_ERR
1192 "SELinux: class %d is incorrect, found %s but should be %s\n",
1193 i, pol_class, def_class);
1194 return -EINVAL;
1195 }
1196 }
1197 for (i = 0; i < kdefs->av_pts_len; i++) {
1198 class_val = kdefs->av_perm_to_string[i].tclass;
1199 perm_val = kdefs->av_perm_to_string[i].value;
1200 def_perm = kdefs->av_perm_to_string[i].name;
1201 if (class_val > p->p_classes.nprim)
1202 continue;
1203 pol_class = p->p_class_val_to_name[class_val-1];
1204 cladatum = hashtab_search(p->p_classes.table, pol_class);
1205 BUG_ON(!cladatum);
1206 perms = &cladatum->permissions;
1207 nprim = 1 << (perms->nprim - 1);
1208 if (perm_val > nprim) {
1209 printk(KERN_INFO
1210 "SELinux: permission %s in class %s not defined in policy\n",
1211 def_perm, pol_class);
1212 if (p->reject_unknown)
1213 return -EINVAL;
1214 if (p->allow_unknown)
1215 p->undefined_perms[class_val-1] |= perm_val;
1216 continue;
1217 }
1218 perdatum = hashtab_search(perms->table, def_perm);
1219 if (perdatum == NULL) {
1220 printk(KERN_ERR
1221 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1222 def_perm, pol_class);
1223 return -EINVAL;
1224 }
1225 pol_val = 1 << (perdatum->value - 1);
1226 if (pol_val != perm_val) {
1227 printk(KERN_ERR
1228 "SELinux: permission %s in class %s has incorrect value\n",
1229 def_perm, pol_class);
1230 return -EINVAL;
1231 }
1232 }
1233 for (i = 0; i < kdefs->av_inherit_len; i++) {
1234 class_val = kdefs->av_inherit[i].tclass;
1235 if (class_val > p->p_classes.nprim)
1236 continue;
1237 pol_class = p->p_class_val_to_name[class_val-1];
1238 cladatum = hashtab_search(p->p_classes.table, pol_class);
1239 BUG_ON(!cladatum);
1240 if (!cladatum->comdatum) {
1241 printk(KERN_ERR
1242 "SELinux: class %s should have an inherits clause but does not\n",
1243 pol_class);
1244 return -EINVAL;
1245 }
1246 tmp = kdefs->av_inherit[i].common_base;
1247 common_pts_len = 0;
1248 while (!(tmp & 0x01)) {
1249 common_pts_len++;
1250 tmp >>= 1;
1251 }
1252 perms = &cladatum->comdatum->permissions;
1253 for (j = 0; j < common_pts_len; j++) {
1254 def_perm = kdefs->av_inherit[i].common_pts[j];
1255 if (j >= perms->nprim) {
1256 printk(KERN_INFO
1257 "SELinux: permission %s in class %s not defined in policy\n",
1258 def_perm, pol_class);
1259 if (p->reject_unknown)
1260 return -EINVAL;
1261 if (p->allow_unknown)
1262 p->undefined_perms[class_val-1] |= (1 << j);
1263 continue;
1264 }
1265 perdatum = hashtab_search(perms->table, def_perm);
1266 if (perdatum == NULL) {
1267 printk(KERN_ERR
1268 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1269 def_perm, pol_class);
1270 return -EINVAL;
1271 }
1272 if (perdatum->value != j + 1) {
1273 printk(KERN_ERR
1274 "SELinux: permission %s in class %s has incorrect value\n",
1275 def_perm, pol_class);
1276 return -EINVAL;
1277 }
1278 }
1279 }
1280 return 0;
1281 }
1282
1283 /* Clone the SID into the new SID table. */
1284 static int clone_sid(u32 sid,
1285 struct context *context,
1286 void *arg)
1287 {
1288 struct sidtab *s = arg;
1289
1290 return sidtab_insert(s, sid, context);
1291 }
1292
1293 static inline int convert_context_handle_invalid_context(struct context *context)
1294 {
1295 int rc = 0;
1296
1297 if (selinux_enforcing) {
1298 rc = -EINVAL;
1299 } else {
1300 char *s;
1301 u32 len;
1302
1303 if (!context_struct_to_string(context, &s, &len)) {
1304 printk(KERN_WARNING
1305 "SELinux: Context %s would be invalid if enforcing\n",
1306 s);
1307 kfree(s);
1308 }
1309 }
1310 return rc;
1311 }
1312
1313 struct convert_context_args {
1314 struct policydb *oldp;
1315 struct policydb *newp;
1316 };
1317
1318 /*
1319 * Convert the values in the security context
1320 * structure `c' from the values specified
1321 * in the policy `p->oldp' to the values specified
1322 * in the policy `p->newp'. Verify that the
1323 * context is valid under the new policy.
1324 */
1325 static int convert_context(u32 key,
1326 struct context *c,
1327 void *p)
1328 {
1329 struct convert_context_args *args;
1330 struct context oldc;
1331 struct role_datum *role;
1332 struct type_datum *typdatum;
1333 struct user_datum *usrdatum;
1334 char *s;
1335 u32 len;
1336 int rc;
1337
1338 args = p;
1339
1340 if (c->str) {
1341 struct context ctx;
1342 rc = string_to_context_struct(args->newp, NULL, c->str,
1343 c->len, &ctx, SECSID_NULL,
1344 GFP_KERNEL);
1345 if (!rc) {
1346 printk(KERN_INFO
1347 "SELinux: Context %s became valid (mapped).\n",
1348 c->str);
1349 /* Replace string with mapped representation. */
1350 kfree(c->str);
1351 memcpy(c, &ctx, sizeof(*c));
1352 goto out;
1353 } else if (rc == -EINVAL) {
1354 /* Retain string representation for later mapping. */
1355 rc = 0;
1356 goto out;
1357 } else {
1358 /* Other error condition, e.g. ENOMEM. */
1359 printk(KERN_ERR
1360 "SELinux: Unable to map context %s, rc = %d.\n",
1361 c->str, -rc);
1362 goto out;
1363 }
1364 }
1365
1366 rc = context_cpy(&oldc, c);
1367 if (rc)
1368 goto out;
1369
1370 rc = -EINVAL;
1371
1372 /* Convert the user. */
1373 usrdatum = hashtab_search(args->newp->p_users.table,
1374 args->oldp->p_user_val_to_name[c->user - 1]);
1375 if (!usrdatum)
1376 goto bad;
1377 c->user = usrdatum->value;
1378
1379 /* Convert the role. */
1380 role = hashtab_search(args->newp->p_roles.table,
1381 args->oldp->p_role_val_to_name[c->role - 1]);
1382 if (!role)
1383 goto bad;
1384 c->role = role->value;
1385
1386 /* Convert the type. */
1387 typdatum = hashtab_search(args->newp->p_types.table,
1388 args->oldp->p_type_val_to_name[c->type - 1]);
1389 if (!typdatum)
1390 goto bad;
1391 c->type = typdatum->value;
1392
1393 rc = mls_convert_context(args->oldp, args->newp, c);
1394 if (rc)
1395 goto bad;
1396
1397 /* Check the validity of the new context. */
1398 if (!policydb_context_isvalid(args->newp, c)) {
1399 rc = convert_context_handle_invalid_context(&oldc);
1400 if (rc)
1401 goto bad;
1402 }
1403
1404 context_destroy(&oldc);
1405 rc = 0;
1406 out:
1407 return rc;
1408 bad:
1409 /* Map old representation to string and save it. */
1410 if (context_struct_to_string(&oldc, &s, &len))
1411 return -ENOMEM;
1412 context_destroy(&oldc);
1413 context_destroy(c);
1414 c->str = s;
1415 c->len = len;
1416 printk(KERN_INFO
1417 "SELinux: Context %s became invalid (unmapped).\n",
1418 c->str);
1419 rc = 0;
1420 goto out;
1421 }
1422
1423 static void security_load_policycaps(void)
1424 {
1425 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1426 POLICYDB_CAPABILITY_NETPEER);
1427 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1428 POLICYDB_CAPABILITY_OPENPERM);
1429 }
1430
1431 extern void selinux_complete_init(void);
1432 static int security_preserve_bools(struct policydb *p);
1433
1434 /**
1435 * security_load_policy - Load a security policy configuration.
1436 * @data: binary policy data
1437 * @len: length of data in bytes
1438 *
1439 * Load a new set of security policy configuration data,
1440 * validate it and convert the SID table as necessary.
1441 * This function will flush the access vector cache after
1442 * loading the new policy.
1443 */
1444 int security_load_policy(void *data, size_t len)
1445 {
1446 struct policydb oldpolicydb, newpolicydb;
1447 struct sidtab oldsidtab, newsidtab;
1448 struct convert_context_args args;
1449 u32 seqno;
1450 int rc = 0;
1451 struct policy_file file = { data, len }, *fp = &file;
1452
1453 LOAD_LOCK;
1454
1455 if (!ss_initialized) {
1456 avtab_cache_init();
1457 if (policydb_read(&policydb, fp)) {
1458 LOAD_UNLOCK;
1459 avtab_cache_destroy();
1460 return -EINVAL;
1461 }
1462 if (policydb_load_isids(&policydb, &sidtab)) {
1463 LOAD_UNLOCK;
1464 policydb_destroy(&policydb);
1465 avtab_cache_destroy();
1466 return -EINVAL;
1467 }
1468 /* Verify that the kernel defined classes are correct. */
1469 if (validate_classes(&policydb)) {
1470 printk(KERN_ERR
1471 "SELinux: the definition of a class is incorrect\n");
1472 LOAD_UNLOCK;
1473 sidtab_destroy(&sidtab);
1474 policydb_destroy(&policydb);
1475 avtab_cache_destroy();
1476 return -EINVAL;
1477 }
1478 security_load_policycaps();
1479 policydb_loaded_version = policydb.policyvers;
1480 ss_initialized = 1;
1481 seqno = ++latest_granting;
1482 LOAD_UNLOCK;
1483 selinux_complete_init();
1484 avc_ss_reset(seqno);
1485 selnl_notify_policyload(seqno);
1486 selinux_netlbl_cache_invalidate();
1487 selinux_xfrm_notify_policyload();
1488 return 0;
1489 }
1490
1491 #if 0
1492 sidtab_hash_eval(&sidtab, "sids");
1493 #endif
1494
1495 if (policydb_read(&newpolicydb, fp)) {
1496 LOAD_UNLOCK;
1497 return -EINVAL;
1498 }
1499
1500 if (sidtab_init(&newsidtab)) {
1501 LOAD_UNLOCK;
1502 policydb_destroy(&newpolicydb);
1503 return -ENOMEM;
1504 }
1505
1506 /* Verify that the kernel defined classes are correct. */
1507 if (validate_classes(&newpolicydb)) {
1508 printk(KERN_ERR
1509 "SELinux: the definition of a class is incorrect\n");
1510 rc = -EINVAL;
1511 goto err;
1512 }
1513
1514 rc = security_preserve_bools(&newpolicydb);
1515 if (rc) {
1516 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1517 goto err;
1518 }
1519
1520 /* Clone the SID table. */
1521 sidtab_shutdown(&sidtab);
1522 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1523 rc = -ENOMEM;
1524 goto err;
1525 }
1526
1527 /*
1528 * Convert the internal representations of contexts
1529 * in the new SID table.
1530 */
1531 args.oldp = &policydb;
1532 args.newp = &newpolicydb;
1533 rc = sidtab_map(&newsidtab, convert_context, &args);
1534 if (rc)
1535 goto err;
1536
1537 /* Save the old policydb and SID table to free later. */
1538 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1539 sidtab_set(&oldsidtab, &sidtab);
1540
1541 /* Install the new policydb and SID table. */
1542 POLICY_WRLOCK;
1543 memcpy(&policydb, &newpolicydb, sizeof policydb);
1544 sidtab_set(&sidtab, &newsidtab);
1545 security_load_policycaps();
1546 seqno = ++latest_granting;
1547 policydb_loaded_version = policydb.policyvers;
1548 POLICY_WRUNLOCK;
1549 LOAD_UNLOCK;
1550
1551 /* Free the old policydb and SID table. */
1552 policydb_destroy(&oldpolicydb);
1553 sidtab_destroy(&oldsidtab);
1554
1555 avc_ss_reset(seqno);
1556 selnl_notify_policyload(seqno);
1557 selinux_netlbl_cache_invalidate();
1558 selinux_xfrm_notify_policyload();
1559
1560 return 0;
1561
1562 err:
1563 LOAD_UNLOCK;
1564 sidtab_destroy(&newsidtab);
1565 policydb_destroy(&newpolicydb);
1566 return rc;
1567
1568 }
1569
1570 /**
1571 * security_port_sid - Obtain the SID for a port.
1572 * @protocol: protocol number
1573 * @port: port number
1574 * @out_sid: security identifier
1575 */
1576 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1577 {
1578 struct ocontext *c;
1579 int rc = 0;
1580
1581 POLICY_RDLOCK;
1582
1583 c = policydb.ocontexts[OCON_PORT];
1584 while (c) {
1585 if (c->u.port.protocol == protocol &&
1586 c->u.port.low_port <= port &&
1587 c->u.port.high_port >= port)
1588 break;
1589 c = c->next;
1590 }
1591
1592 if (c) {
1593 if (!c->sid[0]) {
1594 rc = sidtab_context_to_sid(&sidtab,
1595 &c->context[0],
1596 &c->sid[0]);
1597 if (rc)
1598 goto out;
1599 }
1600 *out_sid = c->sid[0];
1601 } else {
1602 *out_sid = SECINITSID_PORT;
1603 }
1604
1605 out:
1606 POLICY_RDUNLOCK;
1607 return rc;
1608 }
1609
1610 /**
1611 * security_netif_sid - Obtain the SID for a network interface.
1612 * @name: interface name
1613 * @if_sid: interface SID
1614 */
1615 int security_netif_sid(char *name, u32 *if_sid)
1616 {
1617 int rc = 0;
1618 struct ocontext *c;
1619
1620 POLICY_RDLOCK;
1621
1622 c = policydb.ocontexts[OCON_NETIF];
1623 while (c) {
1624 if (strcmp(name, c->u.name) == 0)
1625 break;
1626 c = c->next;
1627 }
1628
1629 if (c) {
1630 if (!c->sid[0] || !c->sid[1]) {
1631 rc = sidtab_context_to_sid(&sidtab,
1632 &c->context[0],
1633 &c->sid[0]);
1634 if (rc)
1635 goto out;
1636 rc = sidtab_context_to_sid(&sidtab,
1637 &c->context[1],
1638 &c->sid[1]);
1639 if (rc)
1640 goto out;
1641 }
1642 *if_sid = c->sid[0];
1643 } else
1644 *if_sid = SECINITSID_NETIF;
1645
1646 out:
1647 POLICY_RDUNLOCK;
1648 return rc;
1649 }
1650
1651 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1652 {
1653 int i, fail = 0;
1654
1655 for (i = 0; i < 4; i++)
1656 if (addr[i] != (input[i] & mask[i])) {
1657 fail = 1;
1658 break;
1659 }
1660
1661 return !fail;
1662 }
1663
1664 /**
1665 * security_node_sid - Obtain the SID for a node (host).
1666 * @domain: communication domain aka address family
1667 * @addrp: address
1668 * @addrlen: address length in bytes
1669 * @out_sid: security identifier
1670 */
1671 int security_node_sid(u16 domain,
1672 void *addrp,
1673 u32 addrlen,
1674 u32 *out_sid)
1675 {
1676 int rc = 0;
1677 struct ocontext *c;
1678
1679 POLICY_RDLOCK;
1680
1681 switch (domain) {
1682 case AF_INET: {
1683 u32 addr;
1684
1685 if (addrlen != sizeof(u32)) {
1686 rc = -EINVAL;
1687 goto out;
1688 }
1689
1690 addr = *((u32 *)addrp);
1691
1692 c = policydb.ocontexts[OCON_NODE];
1693 while (c) {
1694 if (c->u.node.addr == (addr & c->u.node.mask))
1695 break;
1696 c = c->next;
1697 }
1698 break;
1699 }
1700
1701 case AF_INET6:
1702 if (addrlen != sizeof(u64) * 2) {
1703 rc = -EINVAL;
1704 goto out;
1705 }
1706 c = policydb.ocontexts[OCON_NODE6];
1707 while (c) {
1708 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1709 c->u.node6.mask))
1710 break;
1711 c = c->next;
1712 }
1713 break;
1714
1715 default:
1716 *out_sid = SECINITSID_NODE;
1717 goto out;
1718 }
1719
1720 if (c) {
1721 if (!c->sid[0]) {
1722 rc = sidtab_context_to_sid(&sidtab,
1723 &c->context[0],
1724 &c->sid[0]);
1725 if (rc)
1726 goto out;
1727 }
1728 *out_sid = c->sid[0];
1729 } else {
1730 *out_sid = SECINITSID_NODE;
1731 }
1732
1733 out:
1734 POLICY_RDUNLOCK;
1735 return rc;
1736 }
1737
1738 #define SIDS_NEL 25
1739
1740 /**
1741 * security_get_user_sids - Obtain reachable SIDs for a user.
1742 * @fromsid: starting SID
1743 * @username: username
1744 * @sids: array of reachable SIDs for user
1745 * @nel: number of elements in @sids
1746 *
1747 * Generate the set of SIDs for legal security contexts
1748 * for a given user that can be reached by @fromsid.
1749 * Set *@sids to point to a dynamically allocated
1750 * array containing the set of SIDs. Set *@nel to the
1751 * number of elements in the array.
1752 */
1753
1754 int security_get_user_sids(u32 fromsid,
1755 char *username,
1756 u32 **sids,
1757 u32 *nel)
1758 {
1759 struct context *fromcon, usercon;
1760 u32 *mysids = NULL, *mysids2, sid;
1761 u32 mynel = 0, maxnel = SIDS_NEL;
1762 struct user_datum *user;
1763 struct role_datum *role;
1764 struct ebitmap_node *rnode, *tnode;
1765 int rc = 0, i, j;
1766
1767 *sids = NULL;
1768 *nel = 0;
1769
1770 if (!ss_initialized)
1771 goto out;
1772
1773 POLICY_RDLOCK;
1774
1775 context_init(&usercon);
1776
1777 fromcon = sidtab_search(&sidtab, fromsid);
1778 if (!fromcon) {
1779 rc = -EINVAL;
1780 goto out_unlock;
1781 }
1782
1783 user = hashtab_search(policydb.p_users.table, username);
1784 if (!user) {
1785 rc = -EINVAL;
1786 goto out_unlock;
1787 }
1788 usercon.user = user->value;
1789
1790 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1791 if (!mysids) {
1792 rc = -ENOMEM;
1793 goto out_unlock;
1794 }
1795
1796 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1797 role = policydb.role_val_to_struct[i];
1798 usercon.role = i+1;
1799 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1800 usercon.type = j+1;
1801
1802 if (mls_setup_user_range(fromcon, user, &usercon))
1803 continue;
1804
1805 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1806 if (rc)
1807 goto out_unlock;
1808 if (mynel < maxnel) {
1809 mysids[mynel++] = sid;
1810 } else {
1811 maxnel += SIDS_NEL;
1812 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1813 if (!mysids2) {
1814 rc = -ENOMEM;
1815 goto out_unlock;
1816 }
1817 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1818 kfree(mysids);
1819 mysids = mysids2;
1820 mysids[mynel++] = sid;
1821 }
1822 }
1823 }
1824
1825 out_unlock:
1826 POLICY_RDUNLOCK;
1827 if (rc || !mynel) {
1828 kfree(mysids);
1829 goto out;
1830 }
1831
1832 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1833 if (!mysids2) {
1834 rc = -ENOMEM;
1835 kfree(mysids);
1836 goto out;
1837 }
1838 for (i = 0, j = 0; i < mynel; i++) {
1839 rc = avc_has_perm_noaudit(fromsid, mysids[i],
1840 SECCLASS_PROCESS,
1841 PROCESS__TRANSITION, AVC_STRICT,
1842 NULL);
1843 if (!rc)
1844 mysids2[j++] = mysids[i];
1845 cond_resched();
1846 }
1847 rc = 0;
1848 kfree(mysids);
1849 *sids = mysids2;
1850 *nel = j;
1851 out:
1852 return rc;
1853 }
1854
1855 /**
1856 * security_genfs_sid - Obtain a SID for a file in a filesystem
1857 * @fstype: filesystem type
1858 * @path: path from root of mount
1859 * @sclass: file security class
1860 * @sid: SID for path
1861 *
1862 * Obtain a SID to use for a file in a filesystem that
1863 * cannot support xattr or use a fixed labeling behavior like
1864 * transition SIDs or task SIDs.
1865 */
1866 int security_genfs_sid(const char *fstype,
1867 char *path,
1868 u16 sclass,
1869 u32 *sid)
1870 {
1871 int len;
1872 struct genfs *genfs;
1873 struct ocontext *c;
1874 int rc = 0, cmp = 0;
1875
1876 while (path[0] == '/' && path[1] == '/')
1877 path++;
1878
1879 POLICY_RDLOCK;
1880
1881 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1882 cmp = strcmp(fstype, genfs->fstype);
1883 if (cmp <= 0)
1884 break;
1885 }
1886
1887 if (!genfs || cmp) {
1888 *sid = SECINITSID_UNLABELED;
1889 rc = -ENOENT;
1890 goto out;
1891 }
1892
1893 for (c = genfs->head; c; c = c->next) {
1894 len = strlen(c->u.name);
1895 if ((!c->v.sclass || sclass == c->v.sclass) &&
1896 (strncmp(c->u.name, path, len) == 0))
1897 break;
1898 }
1899
1900 if (!c) {
1901 *sid = SECINITSID_UNLABELED;
1902 rc = -ENOENT;
1903 goto out;
1904 }
1905
1906 if (!c->sid[0]) {
1907 rc = sidtab_context_to_sid(&sidtab,
1908 &c->context[0],
1909 &c->sid[0]);
1910 if (rc)
1911 goto out;
1912 }
1913
1914 *sid = c->sid[0];
1915 out:
1916 POLICY_RDUNLOCK;
1917 return rc;
1918 }
1919
1920 /**
1921 * security_fs_use - Determine how to handle labeling for a filesystem.
1922 * @fstype: filesystem type
1923 * @behavior: labeling behavior
1924 * @sid: SID for filesystem (superblock)
1925 */
1926 int security_fs_use(
1927 const char *fstype,
1928 unsigned int *behavior,
1929 u32 *sid)
1930 {
1931 int rc = 0;
1932 struct ocontext *c;
1933
1934 POLICY_RDLOCK;
1935
1936 c = policydb.ocontexts[OCON_FSUSE];
1937 while (c) {
1938 if (strcmp(fstype, c->u.name) == 0)
1939 break;
1940 c = c->next;
1941 }
1942
1943 if (c) {
1944 *behavior = c->v.behavior;
1945 if (!c->sid[0]) {
1946 rc = sidtab_context_to_sid(&sidtab,
1947 &c->context[0],
1948 &c->sid[0]);
1949 if (rc)
1950 goto out;
1951 }
1952 *sid = c->sid[0];
1953 } else {
1954 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1955 if (rc) {
1956 *behavior = SECURITY_FS_USE_NONE;
1957 rc = 0;
1958 } else {
1959 *behavior = SECURITY_FS_USE_GENFS;
1960 }
1961 }
1962
1963 out:
1964 POLICY_RDUNLOCK;
1965 return rc;
1966 }
1967
1968 int security_get_bools(int *len, char ***names, int **values)
1969 {
1970 int i, rc = -ENOMEM;
1971
1972 POLICY_RDLOCK;
1973 *names = NULL;
1974 *values = NULL;
1975
1976 *len = policydb.p_bools.nprim;
1977 if (!*len) {
1978 rc = 0;
1979 goto out;
1980 }
1981
1982 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
1983 if (!*names)
1984 goto err;
1985
1986 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1987 if (!*values)
1988 goto err;
1989
1990 for (i = 0; i < *len; i++) {
1991 size_t name_len;
1992 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1993 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1994 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1995 if (!(*names)[i])
1996 goto err;
1997 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1998 (*names)[i][name_len - 1] = 0;
1999 }
2000 rc = 0;
2001 out:
2002 POLICY_RDUNLOCK;
2003 return rc;
2004 err:
2005 if (*names) {
2006 for (i = 0; i < *len; i++)
2007 kfree((*names)[i]);
2008 }
2009 kfree(*values);
2010 goto out;
2011 }
2012
2013
2014 int security_set_bools(int len, int *values)
2015 {
2016 int i, rc = 0;
2017 int lenp, seqno = 0;
2018 struct cond_node *cur;
2019
2020 POLICY_WRLOCK;
2021
2022 lenp = policydb.p_bools.nprim;
2023 if (len != lenp) {
2024 rc = -EFAULT;
2025 goto out;
2026 }
2027
2028 for (i = 0; i < len; i++) {
2029 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2030 audit_log(current->audit_context, GFP_ATOMIC,
2031 AUDIT_MAC_CONFIG_CHANGE,
2032 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2033 policydb.p_bool_val_to_name[i],
2034 !!values[i],
2035 policydb.bool_val_to_struct[i]->state,
2036 audit_get_loginuid(current),
2037 audit_get_sessionid(current));
2038 }
2039 if (values[i])
2040 policydb.bool_val_to_struct[i]->state = 1;
2041 else
2042 policydb.bool_val_to_struct[i]->state = 0;
2043 }
2044
2045 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
2046 rc = evaluate_cond_node(&policydb, cur);
2047 if (rc)
2048 goto out;
2049 }
2050
2051 seqno = ++latest_granting;
2052
2053 out:
2054 POLICY_WRUNLOCK;
2055 if (!rc) {
2056 avc_ss_reset(seqno);
2057 selnl_notify_policyload(seqno);
2058 selinux_xfrm_notify_policyload();
2059 }
2060 return rc;
2061 }
2062
2063 int security_get_bool_value(int bool)
2064 {
2065 int rc = 0;
2066 int len;
2067
2068 POLICY_RDLOCK;
2069
2070 len = policydb.p_bools.nprim;
2071 if (bool >= len) {
2072 rc = -EFAULT;
2073 goto out;
2074 }
2075
2076 rc = policydb.bool_val_to_struct[bool]->state;
2077 out:
2078 POLICY_RDUNLOCK;
2079 return rc;
2080 }
2081
2082 static int security_preserve_bools(struct policydb *p)
2083 {
2084 int rc, nbools = 0, *bvalues = NULL, i;
2085 char **bnames = NULL;
2086 struct cond_bool_datum *booldatum;
2087 struct cond_node *cur;
2088
2089 rc = security_get_bools(&nbools, &bnames, &bvalues);
2090 if (rc)
2091 goto out;
2092 for (i = 0; i < nbools; i++) {
2093 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2094 if (booldatum)
2095 booldatum->state = bvalues[i];
2096 }
2097 for (cur = p->cond_list; cur != NULL; cur = cur->next) {
2098 rc = evaluate_cond_node(p, cur);
2099 if (rc)
2100 goto out;
2101 }
2102
2103 out:
2104 if (bnames) {
2105 for (i = 0; i < nbools; i++)
2106 kfree(bnames[i]);
2107 }
2108 kfree(bnames);
2109 kfree(bvalues);
2110 return rc;
2111 }
2112
2113 /*
2114 * security_sid_mls_copy() - computes a new sid based on the given
2115 * sid and the mls portion of mls_sid.
2116 */
2117 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2118 {
2119 struct context *context1;
2120 struct context *context2;
2121 struct context newcon;
2122 char *s;
2123 u32 len;
2124 int rc = 0;
2125
2126 if (!ss_initialized || !selinux_mls_enabled) {
2127 *new_sid = sid;
2128 goto out;
2129 }
2130
2131 context_init(&newcon);
2132
2133 POLICY_RDLOCK;
2134 context1 = sidtab_search(&sidtab, sid);
2135 if (!context1) {
2136 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2137 __func__, sid);
2138 rc = -EINVAL;
2139 goto out_unlock;
2140 }
2141
2142 context2 = sidtab_search(&sidtab, mls_sid);
2143 if (!context2) {
2144 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2145 __func__, mls_sid);
2146 rc = -EINVAL;
2147 goto out_unlock;
2148 }
2149
2150 newcon.user = context1->user;
2151 newcon.role = context1->role;
2152 newcon.type = context1->type;
2153 rc = mls_context_cpy(&newcon, context2);
2154 if (rc)
2155 goto out_unlock;
2156
2157 /* Check the validity of the new context. */
2158 if (!policydb_context_isvalid(&policydb, &newcon)) {
2159 rc = convert_context_handle_invalid_context(&newcon);
2160 if (rc)
2161 goto bad;
2162 }
2163
2164 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2165 goto out_unlock;
2166
2167 bad:
2168 if (!context_struct_to_string(&newcon, &s, &len)) {
2169 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2170 "security_sid_mls_copy: invalid context %s", s);
2171 kfree(s);
2172 }
2173
2174 out_unlock:
2175 POLICY_RDUNLOCK;
2176 context_destroy(&newcon);
2177 out:
2178 return rc;
2179 }
2180
2181 /**
2182 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2183 * @nlbl_sid: NetLabel SID
2184 * @nlbl_type: NetLabel labeling protocol type
2185 * @xfrm_sid: XFRM SID
2186 *
2187 * Description:
2188 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2189 * resolved into a single SID it is returned via @peer_sid and the function
2190 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2191 * returns a negative value. A table summarizing the behavior is below:
2192 *
2193 * | function return | @sid
2194 * ------------------------------+-----------------+-----------------
2195 * no peer labels | 0 | SECSID_NULL
2196 * single peer label | 0 | <peer_label>
2197 * multiple, consistent labels | 0 | <peer_label>
2198 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2199 *
2200 */
2201 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2202 u32 xfrm_sid,
2203 u32 *peer_sid)
2204 {
2205 int rc;
2206 struct context *nlbl_ctx;
2207 struct context *xfrm_ctx;
2208
2209 /* handle the common (which also happens to be the set of easy) cases
2210 * right away, these two if statements catch everything involving a
2211 * single or absent peer SID/label */
2212 if (xfrm_sid == SECSID_NULL) {
2213 *peer_sid = nlbl_sid;
2214 return 0;
2215 }
2216 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2217 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2218 * is present */
2219 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2220 *peer_sid = xfrm_sid;
2221 return 0;
2222 }
2223
2224 /* we don't need to check ss_initialized here since the only way both
2225 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2226 * security server was initialized and ss_initialized was true */
2227 if (!selinux_mls_enabled) {
2228 *peer_sid = SECSID_NULL;
2229 return 0;
2230 }
2231
2232 POLICY_RDLOCK;
2233
2234 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2235 if (!nlbl_ctx) {
2236 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2237 __func__, nlbl_sid);
2238 rc = -EINVAL;
2239 goto out_slowpath;
2240 }
2241 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2242 if (!xfrm_ctx) {
2243 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2244 __func__, xfrm_sid);
2245 rc = -EINVAL;
2246 goto out_slowpath;
2247 }
2248 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2249
2250 out_slowpath:
2251 POLICY_RDUNLOCK;
2252 if (rc == 0)
2253 /* at present NetLabel SIDs/labels really only carry MLS
2254 * information so if the MLS portion of the NetLabel SID
2255 * matches the MLS portion of the labeled XFRM SID/label
2256 * then pass along the XFRM SID as it is the most
2257 * expressive */
2258 *peer_sid = xfrm_sid;
2259 else
2260 *peer_sid = SECSID_NULL;
2261 return rc;
2262 }
2263
2264 static int get_classes_callback(void *k, void *d, void *args)
2265 {
2266 struct class_datum *datum = d;
2267 char *name = k, **classes = args;
2268 int value = datum->value - 1;
2269
2270 classes[value] = kstrdup(name, GFP_ATOMIC);
2271 if (!classes[value])
2272 return -ENOMEM;
2273
2274 return 0;
2275 }
2276
2277 int security_get_classes(char ***classes, int *nclasses)
2278 {
2279 int rc = -ENOMEM;
2280
2281 POLICY_RDLOCK;
2282
2283 *nclasses = policydb.p_classes.nprim;
2284 *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2285 if (!*classes)
2286 goto out;
2287
2288 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2289 *classes);
2290 if (rc < 0) {
2291 int i;
2292 for (i = 0; i < *nclasses; i++)
2293 kfree((*classes)[i]);
2294 kfree(*classes);
2295 }
2296
2297 out:
2298 POLICY_RDUNLOCK;
2299 return rc;
2300 }
2301
2302 static int get_permissions_callback(void *k, void *d, void *args)
2303 {
2304 struct perm_datum *datum = d;
2305 char *name = k, **perms = args;
2306 int value = datum->value - 1;
2307
2308 perms[value] = kstrdup(name, GFP_ATOMIC);
2309 if (!perms[value])
2310 return -ENOMEM;
2311
2312 return 0;
2313 }
2314
2315 int security_get_permissions(char *class, char ***perms, int *nperms)
2316 {
2317 int rc = -ENOMEM, i;
2318 struct class_datum *match;
2319
2320 POLICY_RDLOCK;
2321
2322 match = hashtab_search(policydb.p_classes.table, class);
2323 if (!match) {
2324 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2325 __func__, class);
2326 rc = -EINVAL;
2327 goto out;
2328 }
2329
2330 *nperms = match->permissions.nprim;
2331 *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2332 if (!*perms)
2333 goto out;
2334
2335 if (match->comdatum) {
2336 rc = hashtab_map(match->comdatum->permissions.table,
2337 get_permissions_callback, *perms);
2338 if (rc < 0)
2339 goto err;
2340 }
2341
2342 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2343 *perms);
2344 if (rc < 0)
2345 goto err;
2346
2347 out:
2348 POLICY_RDUNLOCK;
2349 return rc;
2350
2351 err:
2352 POLICY_RDUNLOCK;
2353 for (i = 0; i < *nperms; i++)
2354 kfree((*perms)[i]);
2355 kfree(*perms);
2356 return rc;
2357 }
2358
2359 int security_get_reject_unknown(void)
2360 {
2361 return policydb.reject_unknown;
2362 }
2363
2364 int security_get_allow_unknown(void)
2365 {
2366 return policydb.allow_unknown;
2367 }
2368
2369 /**
2370 * security_policycap_supported - Check for a specific policy capability
2371 * @req_cap: capability
2372 *
2373 * Description:
2374 * This function queries the currently loaded policy to see if it supports the
2375 * capability specified by @req_cap. Returns true (1) if the capability is
2376 * supported, false (0) if it isn't supported.
2377 *
2378 */
2379 int security_policycap_supported(unsigned int req_cap)
2380 {
2381 int rc;
2382
2383 POLICY_RDLOCK;
2384 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2385 POLICY_RDUNLOCK;
2386
2387 return rc;
2388 }
2389
2390 struct selinux_audit_rule {
2391 u32 au_seqno;
2392 struct context au_ctxt;
2393 };
2394
2395 void selinux_audit_rule_free(void *vrule)
2396 {
2397 struct selinux_audit_rule *rule = vrule;
2398
2399 if (rule) {
2400 context_destroy(&rule->au_ctxt);
2401 kfree(rule);
2402 }
2403 }
2404
2405 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2406 {
2407 struct selinux_audit_rule *tmprule;
2408 struct role_datum *roledatum;
2409 struct type_datum *typedatum;
2410 struct user_datum *userdatum;
2411 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2412 int rc = 0;
2413
2414 *rule = NULL;
2415
2416 if (!ss_initialized)
2417 return -EOPNOTSUPP;
2418
2419 switch (field) {
2420 case AUDIT_SUBJ_USER:
2421 case AUDIT_SUBJ_ROLE:
2422 case AUDIT_SUBJ_TYPE:
2423 case AUDIT_OBJ_USER:
2424 case AUDIT_OBJ_ROLE:
2425 case AUDIT_OBJ_TYPE:
2426 /* only 'equals' and 'not equals' fit user, role, and type */
2427 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2428 return -EINVAL;
2429 break;
2430 case AUDIT_SUBJ_SEN:
2431 case AUDIT_SUBJ_CLR:
2432 case AUDIT_OBJ_LEV_LOW:
2433 case AUDIT_OBJ_LEV_HIGH:
2434 /* we do not allow a range, indicated by the presense of '-' */
2435 if (strchr(rulestr, '-'))
2436 return -EINVAL;
2437 break;
2438 default:
2439 /* only the above fields are valid */
2440 return -EINVAL;
2441 }
2442
2443 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2444 if (!tmprule)
2445 return -ENOMEM;
2446
2447 context_init(&tmprule->au_ctxt);
2448
2449 POLICY_RDLOCK;
2450
2451 tmprule->au_seqno = latest_granting;
2452
2453 switch (field) {
2454 case AUDIT_SUBJ_USER:
2455 case AUDIT_OBJ_USER:
2456 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2457 if (!userdatum)
2458 rc = -EINVAL;
2459 else
2460 tmprule->au_ctxt.user = userdatum->value;
2461 break;
2462 case AUDIT_SUBJ_ROLE:
2463 case AUDIT_OBJ_ROLE:
2464 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2465 if (!roledatum)
2466 rc = -EINVAL;
2467 else
2468 tmprule->au_ctxt.role = roledatum->value;
2469 break;
2470 case AUDIT_SUBJ_TYPE:
2471 case AUDIT_OBJ_TYPE:
2472 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2473 if (!typedatum)
2474 rc = -EINVAL;
2475 else
2476 tmprule->au_ctxt.type = typedatum->value;
2477 break;
2478 case AUDIT_SUBJ_SEN:
2479 case AUDIT_SUBJ_CLR:
2480 case AUDIT_OBJ_LEV_LOW:
2481 case AUDIT_OBJ_LEV_HIGH:
2482 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2483 break;
2484 }
2485
2486 POLICY_RDUNLOCK;
2487
2488 if (rc) {
2489 selinux_audit_rule_free(tmprule);
2490 tmprule = NULL;
2491 }
2492
2493 *rule = tmprule;
2494
2495 return rc;
2496 }
2497
2498 /* Check to see if the rule contains any selinux fields */
2499 int selinux_audit_rule_known(struct audit_krule *rule)
2500 {
2501 int i;
2502
2503 for (i = 0; i < rule->field_count; i++) {
2504 struct audit_field *f = &rule->fields[i];
2505 switch (f->type) {
2506 case AUDIT_SUBJ_USER:
2507 case AUDIT_SUBJ_ROLE:
2508 case AUDIT_SUBJ_TYPE:
2509 case AUDIT_SUBJ_SEN:
2510 case AUDIT_SUBJ_CLR:
2511 case AUDIT_OBJ_USER:
2512 case AUDIT_OBJ_ROLE:
2513 case AUDIT_OBJ_TYPE:
2514 case AUDIT_OBJ_LEV_LOW:
2515 case AUDIT_OBJ_LEV_HIGH:
2516 return 1;
2517 }
2518 }
2519
2520 return 0;
2521 }
2522
2523 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2524 struct audit_context *actx)
2525 {
2526 struct context *ctxt;
2527 struct mls_level *level;
2528 struct selinux_audit_rule *rule = vrule;
2529 int match = 0;
2530
2531 if (!rule) {
2532 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2533 "selinux_audit_rule_match: missing rule\n");
2534 return -ENOENT;
2535 }
2536
2537 POLICY_RDLOCK;
2538
2539 if (rule->au_seqno < latest_granting) {
2540 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2541 "selinux_audit_rule_match: stale rule\n");
2542 match = -ESTALE;
2543 goto out;
2544 }
2545
2546 ctxt = sidtab_search(&sidtab, sid);
2547 if (!ctxt) {
2548 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2549 "selinux_audit_rule_match: unrecognized SID %d\n",
2550 sid);
2551 match = -ENOENT;
2552 goto out;
2553 }
2554
2555 /* a field/op pair that is not caught here will simply fall through
2556 without a match */
2557 switch (field) {
2558 case AUDIT_SUBJ_USER:
2559 case AUDIT_OBJ_USER:
2560 switch (op) {
2561 case AUDIT_EQUAL:
2562 match = (ctxt->user == rule->au_ctxt.user);
2563 break;
2564 case AUDIT_NOT_EQUAL:
2565 match = (ctxt->user != rule->au_ctxt.user);
2566 break;
2567 }
2568 break;
2569 case AUDIT_SUBJ_ROLE:
2570 case AUDIT_OBJ_ROLE:
2571 switch (op) {
2572 case AUDIT_EQUAL:
2573 match = (ctxt->role == rule->au_ctxt.role);
2574 break;
2575 case AUDIT_NOT_EQUAL:
2576 match = (ctxt->role != rule->au_ctxt.role);
2577 break;
2578 }
2579 break;
2580 case AUDIT_SUBJ_TYPE:
2581 case AUDIT_OBJ_TYPE:
2582 switch (op) {
2583 case AUDIT_EQUAL:
2584 match = (ctxt->type == rule->au_ctxt.type);
2585 break;
2586 case AUDIT_NOT_EQUAL:
2587 match = (ctxt->type != rule->au_ctxt.type);
2588 break;
2589 }
2590 break;
2591 case AUDIT_SUBJ_SEN:
2592 case AUDIT_SUBJ_CLR:
2593 case AUDIT_OBJ_LEV_LOW:
2594 case AUDIT_OBJ_LEV_HIGH:
2595 level = ((field == AUDIT_SUBJ_SEN ||
2596 field == AUDIT_OBJ_LEV_LOW) ?
2597 &ctxt->range.level[0] : &ctxt->range.level[1]);
2598 switch (op) {
2599 case AUDIT_EQUAL:
2600 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2601 level);
2602 break;
2603 case AUDIT_NOT_EQUAL:
2604 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2605 level);
2606 break;
2607 case AUDIT_LESS_THAN:
2608 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2609 level) &&
2610 !mls_level_eq(&rule->au_ctxt.range.level[0],
2611 level));
2612 break;
2613 case AUDIT_LESS_THAN_OR_EQUAL:
2614 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2615 level);
2616 break;
2617 case AUDIT_GREATER_THAN:
2618 match = (mls_level_dom(level,
2619 &rule->au_ctxt.range.level[0]) &&
2620 !mls_level_eq(level,
2621 &rule->au_ctxt.range.level[0]));
2622 break;
2623 case AUDIT_GREATER_THAN_OR_EQUAL:
2624 match = mls_level_dom(level,
2625 &rule->au_ctxt.range.level[0]);
2626 break;
2627 }
2628 }
2629
2630 out:
2631 POLICY_RDUNLOCK;
2632 return match;
2633 }
2634
2635 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2636
2637 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2638 u16 class, u32 perms, u32 *retained)
2639 {
2640 int err = 0;
2641
2642 if (event == AVC_CALLBACK_RESET && aurule_callback)
2643 err = aurule_callback();
2644 return err;
2645 }
2646
2647 static int __init aurule_init(void)
2648 {
2649 int err;
2650
2651 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2652 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2653 if (err)
2654 panic("avc_add_callback() failed, error %d\n", err);
2655
2656 return err;
2657 }
2658 __initcall(aurule_init);
2659
2660 #ifdef CONFIG_NETLABEL
2661 /**
2662 * security_netlbl_cache_add - Add an entry to the NetLabel cache
2663 * @secattr: the NetLabel packet security attributes
2664 * @sid: the SELinux SID
2665 *
2666 * Description:
2667 * Attempt to cache the context in @ctx, which was derived from the packet in
2668 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
2669 * already been initialized.
2670 *
2671 */
2672 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2673 u32 sid)
2674 {
2675 u32 *sid_cache;
2676
2677 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2678 if (sid_cache == NULL)
2679 return;
2680 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2681 if (secattr->cache == NULL) {
2682 kfree(sid_cache);
2683 return;
2684 }
2685
2686 *sid_cache = sid;
2687 secattr->cache->free = kfree;
2688 secattr->cache->data = sid_cache;
2689 secattr->flags |= NETLBL_SECATTR_CACHE;
2690 }
2691
2692 /**
2693 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2694 * @secattr: the NetLabel packet security attributes
2695 * @sid: the SELinux SID
2696 *
2697 * Description:
2698 * Convert the given NetLabel security attributes in @secattr into a
2699 * SELinux SID. If the @secattr field does not contain a full SELinux
2700 * SID/context then use SECINITSID_NETMSG as the foundation. If possibile the
2701 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2702 * allow the @secattr to be used by NetLabel to cache the secattr to SID
2703 * conversion for future lookups. Returns zero on success, negative values on
2704 * failure.
2705 *
2706 */
2707 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2708 u32 *sid)
2709 {
2710 int rc = -EIDRM;
2711 struct context *ctx;
2712 struct context ctx_new;
2713
2714 if (!ss_initialized) {
2715 *sid = SECSID_NULL;
2716 return 0;
2717 }
2718
2719 POLICY_RDLOCK;
2720
2721 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2722 *sid = *(u32 *)secattr->cache->data;
2723 rc = 0;
2724 } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2725 *sid = secattr->attr.secid;
2726 rc = 0;
2727 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2728 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2729 if (ctx == NULL)
2730 goto netlbl_secattr_to_sid_return;
2731
2732 ctx_new.user = ctx->user;
2733 ctx_new.role = ctx->role;
2734 ctx_new.type = ctx->type;
2735 mls_import_netlbl_lvl(&ctx_new, secattr);
2736 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2737 if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2738 secattr->attr.mls.cat) != 0)
2739 goto netlbl_secattr_to_sid_return;
2740 ctx_new.range.level[1].cat.highbit =
2741 ctx_new.range.level[0].cat.highbit;
2742 ctx_new.range.level[1].cat.node =
2743 ctx_new.range.level[0].cat.node;
2744 } else {
2745 ebitmap_init(&ctx_new.range.level[0].cat);
2746 ebitmap_init(&ctx_new.range.level[1].cat);
2747 }
2748 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2749 goto netlbl_secattr_to_sid_return_cleanup;
2750
2751 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2752 if (rc != 0)
2753 goto netlbl_secattr_to_sid_return_cleanup;
2754
2755 security_netlbl_cache_add(secattr, *sid);
2756
2757 ebitmap_destroy(&ctx_new.range.level[0].cat);
2758 } else {
2759 *sid = SECSID_NULL;
2760 rc = 0;
2761 }
2762
2763 netlbl_secattr_to_sid_return:
2764 POLICY_RDUNLOCK;
2765 return rc;
2766 netlbl_secattr_to_sid_return_cleanup:
2767 ebitmap_destroy(&ctx_new.range.level[0].cat);
2768 goto netlbl_secattr_to_sid_return;
2769 }
2770
2771 /**
2772 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2773 * @sid: the SELinux SID
2774 * @secattr: the NetLabel packet security attributes
2775 *
2776 * Description:
2777 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2778 * Returns zero on success, negative values on failure.
2779 *
2780 */
2781 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2782 {
2783 int rc = -ENOENT;
2784 struct context *ctx;
2785
2786 if (!ss_initialized)
2787 return 0;
2788
2789 POLICY_RDLOCK;
2790 ctx = sidtab_search(&sidtab, sid);
2791 if (ctx == NULL)
2792 goto netlbl_sid_to_secattr_failure;
2793 secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2794 GFP_ATOMIC);
2795 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY;
2796 mls_export_netlbl_lvl(ctx, secattr);
2797 rc = mls_export_netlbl_cat(ctx, secattr);
2798 if (rc != 0)
2799 goto netlbl_sid_to_secattr_failure;
2800 POLICY_RDUNLOCK;
2801
2802 return 0;
2803
2804 netlbl_sid_to_secattr_failure:
2805 POLICY_RDUNLOCK;
2806 return rc;
2807 }
2808 #endif /* CONFIG_NETLABEL */
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