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