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Merge branch 'linus' into core/softlockup
[mirror_ubuntu-hirsute-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 #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
75 static struct sidtab sidtab;
76 struct policydb policydb;
77 int ss_initialized;
78
79 /*
80 * The largest sequence number that has been used when
81 * providing an access decision to the access vector cache.
82 * The sequence number only changes when a policy change
83 * occurs.
84 */
85 static u32 latest_granting;
86
87 /* Forward declaration. */
88 static int context_struct_to_string(struct context *context, char **scontext,
89 u32 *scontext_len);
90
91 /*
92 * Return the boolean value of a constraint expression
93 * when it is applied to the specified source and target
94 * security contexts.
95 *
96 * xcontext is a special beast... It is used by the validatetrans rules
97 * only. For these rules, scontext is the context before the transition,
98 * tcontext is the context after the transition, and xcontext is the context
99 * of the process performing the transition. All other callers of
100 * constraint_expr_eval should pass in NULL for xcontext.
101 */
102 static int constraint_expr_eval(struct context *scontext,
103 struct context *tcontext,
104 struct context *xcontext,
105 struct constraint_expr *cexpr)
106 {
107 u32 val1, val2;
108 struct context *c;
109 struct role_datum *r1, *r2;
110 struct mls_level *l1, *l2;
111 struct constraint_expr *e;
112 int s[CEXPR_MAXDEPTH];
113 int sp = -1;
114
115 for (e = cexpr; e; e = e->next) {
116 switch (e->expr_type) {
117 case CEXPR_NOT:
118 BUG_ON(sp < 0);
119 s[sp] = !s[sp];
120 break;
121 case CEXPR_AND:
122 BUG_ON(sp < 1);
123 sp--;
124 s[sp] &= s[sp+1];
125 break;
126 case CEXPR_OR:
127 BUG_ON(sp < 1);
128 sp--;
129 s[sp] |= s[sp+1];
130 break;
131 case CEXPR_ATTR:
132 if (sp == (CEXPR_MAXDEPTH-1))
133 return 0;
134 switch (e->attr) {
135 case CEXPR_USER:
136 val1 = scontext->user;
137 val2 = tcontext->user;
138 break;
139 case CEXPR_TYPE:
140 val1 = scontext->type;
141 val2 = tcontext->type;
142 break;
143 case CEXPR_ROLE:
144 val1 = scontext->role;
145 val2 = tcontext->role;
146 r1 = policydb.role_val_to_struct[val1 - 1];
147 r2 = policydb.role_val_to_struct[val2 - 1];
148 switch (e->op) {
149 case CEXPR_DOM:
150 s[++sp] = ebitmap_get_bit(&r1->dominates,
151 val2 - 1);
152 continue;
153 case CEXPR_DOMBY:
154 s[++sp] = ebitmap_get_bit(&r2->dominates,
155 val1 - 1);
156 continue;
157 case CEXPR_INCOMP:
158 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
159 val2 - 1) &&
160 !ebitmap_get_bit(&r2->dominates,
161 val1 - 1));
162 continue;
163 default:
164 break;
165 }
166 break;
167 case CEXPR_L1L2:
168 l1 = &(scontext->range.level[0]);
169 l2 = &(tcontext->range.level[0]);
170 goto mls_ops;
171 case CEXPR_L1H2:
172 l1 = &(scontext->range.level[0]);
173 l2 = &(tcontext->range.level[1]);
174 goto mls_ops;
175 case CEXPR_H1L2:
176 l1 = &(scontext->range.level[1]);
177 l2 = &(tcontext->range.level[0]);
178 goto mls_ops;
179 case CEXPR_H1H2:
180 l1 = &(scontext->range.level[1]);
181 l2 = &(tcontext->range.level[1]);
182 goto mls_ops;
183 case CEXPR_L1H1:
184 l1 = &(scontext->range.level[0]);
185 l2 = &(scontext->range.level[1]);
186 goto mls_ops;
187 case CEXPR_L2H2:
188 l1 = &(tcontext->range.level[0]);
189 l2 = &(tcontext->range.level[1]);
190 goto mls_ops;
191 mls_ops:
192 switch (e->op) {
193 case CEXPR_EQ:
194 s[++sp] = mls_level_eq(l1, l2);
195 continue;
196 case CEXPR_NEQ:
197 s[++sp] = !mls_level_eq(l1, l2);
198 continue;
199 case CEXPR_DOM:
200 s[++sp] = mls_level_dom(l1, l2);
201 continue;
202 case CEXPR_DOMBY:
203 s[++sp] = mls_level_dom(l2, l1);
204 continue;
205 case CEXPR_INCOMP:
206 s[++sp] = mls_level_incomp(l2, l1);
207 continue;
208 default:
209 BUG();
210 return 0;
211 }
212 break;
213 default:
214 BUG();
215 return 0;
216 }
217
218 switch (e->op) {
219 case CEXPR_EQ:
220 s[++sp] = (val1 == val2);
221 break;
222 case CEXPR_NEQ:
223 s[++sp] = (val1 != val2);
224 break;
225 default:
226 BUG();
227 return 0;
228 }
229 break;
230 case CEXPR_NAMES:
231 if (sp == (CEXPR_MAXDEPTH-1))
232 return 0;
233 c = scontext;
234 if (e->attr & CEXPR_TARGET)
235 c = tcontext;
236 else if (e->attr & CEXPR_XTARGET) {
237 c = xcontext;
238 if (!c) {
239 BUG();
240 return 0;
241 }
242 }
243 if (e->attr & CEXPR_USER)
244 val1 = c->user;
245 else if (e->attr & CEXPR_ROLE)
246 val1 = c->role;
247 else if (e->attr & CEXPR_TYPE)
248 val1 = c->type;
249 else {
250 BUG();
251 return 0;
252 }
253
254 switch (e->op) {
255 case CEXPR_EQ:
256 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
257 break;
258 case CEXPR_NEQ:
259 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
260 break;
261 default:
262 BUG();
263 return 0;
264 }
265 break;
266 default:
267 BUG();
268 return 0;
269 }
270 }
271
272 BUG_ON(sp != 0);
273 return s[0];
274 }
275
276 /*
277 * Compute access vectors based on a context structure pair for
278 * the permissions in a particular class.
279 */
280 static int context_struct_compute_av(struct context *scontext,
281 struct context *tcontext,
282 u16 tclass,
283 u32 requested,
284 struct av_decision *avd)
285 {
286 struct constraint_node *constraint;
287 struct role_allow *ra;
288 struct avtab_key avkey;
289 struct avtab_node *node;
290 struct class_datum *tclass_datum;
291 struct ebitmap *sattr, *tattr;
292 struct ebitmap_node *snode, *tnode;
293 const struct selinux_class_perm *kdefs = &selinux_class_perm;
294 unsigned int i, j;
295
296 /*
297 * Remap extended Netlink classes for old policy versions.
298 * Do this here rather than socket_type_to_security_class()
299 * in case a newer policy version is loaded, allowing sockets
300 * to remain in the correct class.
301 */
302 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
303 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
304 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
305 tclass = SECCLASS_NETLINK_SOCKET;
306
307 /*
308 * Initialize the access vectors to the default values.
309 */
310 avd->allowed = 0;
311 avd->decided = 0xffffffff;
312 avd->auditallow = 0;
313 avd->auditdeny = 0xffffffff;
314 avd->seqno = latest_granting;
315
316 /*
317 * Check for all the invalid cases.
318 * - tclass 0
319 * - tclass > policy and > kernel
320 * - tclass > policy but is a userspace class
321 * - tclass > policy but we do not allow unknowns
322 */
323 if (unlikely(!tclass))
324 goto inval_class;
325 if (unlikely(tclass > policydb.p_classes.nprim))
326 if (tclass > kdefs->cts_len ||
327 !kdefs->class_to_string[tclass] ||
328 !policydb.allow_unknown)
329 goto inval_class;
330
331 /*
332 * Kernel class and we allow unknown so pad the allow decision
333 * the pad will be all 1 for unknown classes.
334 */
335 if (tclass <= kdefs->cts_len && policydb.allow_unknown)
336 avd->allowed = policydb.undefined_perms[tclass - 1];
337
338 /*
339 * Not in policy. Since decision is completed (all 1 or all 0) return.
340 */
341 if (unlikely(tclass > policydb.p_classes.nprim))
342 return 0;
343
344 tclass_datum = policydb.class_val_to_struct[tclass - 1];
345
346 /*
347 * If a specific type enforcement rule was defined for
348 * this permission check, then use it.
349 */
350 avkey.target_class = tclass;
351 avkey.specified = AVTAB_AV;
352 sattr = &policydb.type_attr_map[scontext->type - 1];
353 tattr = &policydb.type_attr_map[tcontext->type - 1];
354 ebitmap_for_each_positive_bit(sattr, snode, i) {
355 ebitmap_for_each_positive_bit(tattr, tnode, j) {
356 avkey.source_type = i + 1;
357 avkey.target_type = j + 1;
358 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
359 node != NULL;
360 node = avtab_search_node_next(node, avkey.specified)) {
361 if (node->key.specified == AVTAB_ALLOWED)
362 avd->allowed |= node->datum.data;
363 else if (node->key.specified == AVTAB_AUDITALLOW)
364 avd->auditallow |= node->datum.data;
365 else if (node->key.specified == AVTAB_AUDITDENY)
366 avd->auditdeny &= node->datum.data;
367 }
368
369 /* Check conditional av table for additional permissions */
370 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
371
372 }
373 }
374
375 /*
376 * Remove any permissions prohibited by a constraint (this includes
377 * the MLS policy).
378 */
379 constraint = tclass_datum->constraints;
380 while (constraint) {
381 if ((constraint->permissions & (avd->allowed)) &&
382 !constraint_expr_eval(scontext, tcontext, NULL,
383 constraint->expr)) {
384 avd->allowed = (avd->allowed) & ~(constraint->permissions);
385 }
386 constraint = constraint->next;
387 }
388
389 /*
390 * If checking process transition permission and the
391 * role is changing, then check the (current_role, new_role)
392 * pair.
393 */
394 if (tclass == SECCLASS_PROCESS &&
395 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
396 scontext->role != tcontext->role) {
397 for (ra = policydb.role_allow; ra; ra = ra->next) {
398 if (scontext->role == ra->role &&
399 tcontext->role == ra->new_role)
400 break;
401 }
402 if (!ra)
403 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
404 PROCESS__DYNTRANSITION);
405 }
406
407 return 0;
408
409 inval_class:
410 if (!tclass || tclass > kdefs->cts_len ||
411 !kdefs->class_to_string[tclass]) {
412 if (printk_ratelimit())
413 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
414 __func__, tclass);
415 return -EINVAL;
416 }
417
418 /*
419 * Known to the kernel, but not to the policy.
420 * Handle as a denial (allowed is 0).
421 */
422 return 0;
423 }
424
425 /*
426 * Given a sid find if the type has the permissive flag set
427 */
428 int security_permissive_sid(u32 sid)
429 {
430 struct context *context;
431 u32 type;
432 int rc;
433
434 read_lock(&policy_rwlock);
435
436 context = sidtab_search(&sidtab, sid);
437 BUG_ON(!context);
438
439 type = context->type;
440 /*
441 * we are intentionally using type here, not type-1, the 0th bit may
442 * someday indicate that we are globally setting permissive in policy.
443 */
444 rc = ebitmap_get_bit(&policydb.permissive_map, type);
445
446 read_unlock(&policy_rwlock);
447 return rc;
448 }
449
450 static int security_validtrans_handle_fail(struct context *ocontext,
451 struct context *ncontext,
452 struct context *tcontext,
453 u16 tclass)
454 {
455 char *o = NULL, *n = NULL, *t = NULL;
456 u32 olen, nlen, tlen;
457
458 if (context_struct_to_string(ocontext, &o, &olen) < 0)
459 goto out;
460 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
461 goto out;
462 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
463 goto out;
464 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
465 "security_validate_transition: denied for"
466 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
467 o, n, t, policydb.p_class_val_to_name[tclass-1]);
468 out:
469 kfree(o);
470 kfree(n);
471 kfree(t);
472
473 if (!selinux_enforcing)
474 return 0;
475 return -EPERM;
476 }
477
478 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
479 u16 tclass)
480 {
481 struct context *ocontext;
482 struct context *ncontext;
483 struct context *tcontext;
484 struct class_datum *tclass_datum;
485 struct constraint_node *constraint;
486 int rc = 0;
487
488 if (!ss_initialized)
489 return 0;
490
491 read_lock(&policy_rwlock);
492
493 /*
494 * Remap extended Netlink classes for old policy versions.
495 * Do this here rather than socket_type_to_security_class()
496 * in case a newer policy version is loaded, allowing sockets
497 * to remain in the correct class.
498 */
499 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
500 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
501 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
502 tclass = SECCLASS_NETLINK_SOCKET;
503
504 if (!tclass || tclass > policydb.p_classes.nprim) {
505 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
506 __func__, tclass);
507 rc = -EINVAL;
508 goto out;
509 }
510 tclass_datum = policydb.class_val_to_struct[tclass - 1];
511
512 ocontext = sidtab_search(&sidtab, oldsid);
513 if (!ocontext) {
514 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
515 __func__, oldsid);
516 rc = -EINVAL;
517 goto out;
518 }
519
520 ncontext = sidtab_search(&sidtab, newsid);
521 if (!ncontext) {
522 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
523 __func__, newsid);
524 rc = -EINVAL;
525 goto out;
526 }
527
528 tcontext = sidtab_search(&sidtab, tasksid);
529 if (!tcontext) {
530 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
531 __func__, tasksid);
532 rc = -EINVAL;
533 goto out;
534 }
535
536 constraint = tclass_datum->validatetrans;
537 while (constraint) {
538 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
539 constraint->expr)) {
540 rc = security_validtrans_handle_fail(ocontext, ncontext,
541 tcontext, tclass);
542 goto out;
543 }
544 constraint = constraint->next;
545 }
546
547 out:
548 read_unlock(&policy_rwlock);
549 return rc;
550 }
551
552 /**
553 * security_compute_av - Compute access vector decisions.
554 * @ssid: source security identifier
555 * @tsid: target security identifier
556 * @tclass: target security class
557 * @requested: requested permissions
558 * @avd: access vector decisions
559 *
560 * Compute a set of access vector decisions based on the
561 * SID pair (@ssid, @tsid) for the permissions in @tclass.
562 * Return -%EINVAL if any of the parameters are invalid or %0
563 * if the access vector decisions were computed successfully.
564 */
565 int security_compute_av(u32 ssid,
566 u32 tsid,
567 u16 tclass,
568 u32 requested,
569 struct av_decision *avd)
570 {
571 struct context *scontext = NULL, *tcontext = NULL;
572 int rc = 0;
573
574 if (!ss_initialized) {
575 avd->allowed = 0xffffffff;
576 avd->decided = 0xffffffff;
577 avd->auditallow = 0;
578 avd->auditdeny = 0xffffffff;
579 avd->seqno = latest_granting;
580 return 0;
581 }
582
583 read_lock(&policy_rwlock);
584
585 scontext = sidtab_search(&sidtab, ssid);
586 if (!scontext) {
587 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
588 __func__, ssid);
589 rc = -EINVAL;
590 goto out;
591 }
592 tcontext = sidtab_search(&sidtab, tsid);
593 if (!tcontext) {
594 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
595 __func__, tsid);
596 rc = -EINVAL;
597 goto out;
598 }
599
600 rc = context_struct_compute_av(scontext, tcontext, tclass,
601 requested, avd);
602 out:
603 read_unlock(&policy_rwlock);
604 return rc;
605 }
606
607 /*
608 * Write the security context string representation of
609 * the context structure `context' into a dynamically
610 * allocated string of the correct size. Set `*scontext'
611 * to point to this string and set `*scontext_len' to
612 * the length of the string.
613 */
614 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
615 {
616 char *scontextp;
617
618 *scontext = NULL;
619 *scontext_len = 0;
620
621 if (context->len) {
622 *scontext_len = context->len;
623 *scontext = kstrdup(context->str, GFP_ATOMIC);
624 if (!(*scontext))
625 return -ENOMEM;
626 return 0;
627 }
628
629 /* Compute the size of the context. */
630 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
631 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
632 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
633 *scontext_len += mls_compute_context_len(context);
634
635 /* Allocate space for the context; caller must free this space. */
636 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
637 if (!scontextp)
638 return -ENOMEM;
639 *scontext = scontextp;
640
641 /*
642 * Copy the user name, role name and type name into the context.
643 */
644 sprintf(scontextp, "%s:%s:%s",
645 policydb.p_user_val_to_name[context->user - 1],
646 policydb.p_role_val_to_name[context->role - 1],
647 policydb.p_type_val_to_name[context->type - 1]);
648 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
649 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
650 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
651
652 mls_sid_to_context(context, &scontextp);
653
654 *scontextp = 0;
655
656 return 0;
657 }
658
659 #include "initial_sid_to_string.h"
660
661 const char *security_get_initial_sid_context(u32 sid)
662 {
663 if (unlikely(sid > SECINITSID_NUM))
664 return NULL;
665 return initial_sid_to_string[sid];
666 }
667
668 static int security_sid_to_context_core(u32 sid, char **scontext,
669 u32 *scontext_len, int force)
670 {
671 struct context *context;
672 int rc = 0;
673
674 *scontext = NULL;
675 *scontext_len = 0;
676
677 if (!ss_initialized) {
678 if (sid <= SECINITSID_NUM) {
679 char *scontextp;
680
681 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
682 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
683 if (!scontextp) {
684 rc = -ENOMEM;
685 goto out;
686 }
687 strcpy(scontextp, initial_sid_to_string[sid]);
688 *scontext = scontextp;
689 goto out;
690 }
691 printk(KERN_ERR "SELinux: %s: called before initial "
692 "load_policy on unknown SID %d\n", __func__, sid);
693 rc = -EINVAL;
694 goto out;
695 }
696 read_lock(&policy_rwlock);
697 if (force)
698 context = sidtab_search_force(&sidtab, sid);
699 else
700 context = sidtab_search(&sidtab, sid);
701 if (!context) {
702 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
703 __func__, sid);
704 rc = -EINVAL;
705 goto out_unlock;
706 }
707 rc = context_struct_to_string(context, scontext, scontext_len);
708 out_unlock:
709 read_unlock(&policy_rwlock);
710 out:
711 return rc;
712
713 }
714
715 /**
716 * security_sid_to_context - Obtain a context for a given SID.
717 * @sid: security identifier, SID
718 * @scontext: security context
719 * @scontext_len: length in bytes
720 *
721 * Write the string representation of the context associated with @sid
722 * into a dynamically allocated string of the correct size. Set @scontext
723 * to point to this string and set @scontext_len to the length of the string.
724 */
725 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
726 {
727 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
728 }
729
730 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
731 {
732 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
733 }
734
735 /*
736 * Caveat: Mutates scontext.
737 */
738 static int string_to_context_struct(struct policydb *pol,
739 struct sidtab *sidtabp,
740 char *scontext,
741 u32 scontext_len,
742 struct context *ctx,
743 u32 def_sid)
744 {
745 struct role_datum *role;
746 struct type_datum *typdatum;
747 struct user_datum *usrdatum;
748 char *scontextp, *p, oldc;
749 int rc = 0;
750
751 context_init(ctx);
752
753 /* Parse the security context. */
754
755 rc = -EINVAL;
756 scontextp = (char *) scontext;
757
758 /* Extract the user. */
759 p = scontextp;
760 while (*p && *p != ':')
761 p++;
762
763 if (*p == 0)
764 goto out;
765
766 *p++ = 0;
767
768 usrdatum = hashtab_search(pol->p_users.table, scontextp);
769 if (!usrdatum)
770 goto out;
771
772 ctx->user = usrdatum->value;
773
774 /* Extract role. */
775 scontextp = p;
776 while (*p && *p != ':')
777 p++;
778
779 if (*p == 0)
780 goto out;
781
782 *p++ = 0;
783
784 role = hashtab_search(pol->p_roles.table, scontextp);
785 if (!role)
786 goto out;
787 ctx->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(pol->p_types.table, scontextp);
797 if (!typdatum)
798 goto out;
799
800 ctx->type = typdatum->value;
801
802 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
803 if (rc)
804 goto out;
805
806 if ((p - scontext) < scontext_len) {
807 rc = -EINVAL;
808 goto out;
809 }
810
811 /* Check the validity of the new context. */
812 if (!policydb_context_isvalid(pol, ctx)) {
813 rc = -EINVAL;
814 context_destroy(ctx);
815 goto out;
816 }
817 rc = 0;
818 out:
819 return rc;
820 }
821
822 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
823 u32 *sid, u32 def_sid, gfp_t gfp_flags,
824 int force)
825 {
826 char *scontext2, *str = NULL;
827 struct context context;
828 int rc = 0;
829
830 if (!ss_initialized) {
831 int i;
832
833 for (i = 1; i < SECINITSID_NUM; i++) {
834 if (!strcmp(initial_sid_to_string[i], scontext)) {
835 *sid = i;
836 return 0;
837 }
838 }
839 *sid = SECINITSID_KERNEL;
840 return 0;
841 }
842 *sid = SECSID_NULL;
843
844 /* Copy the string so that we can modify the copy as we parse it. */
845 scontext2 = kmalloc(scontext_len+1, gfp_flags);
846 if (!scontext2)
847 return -ENOMEM;
848 memcpy(scontext2, scontext, scontext_len);
849 scontext2[scontext_len] = 0;
850
851 if (force) {
852 /* Save another copy for storing in uninterpreted form */
853 str = kstrdup(scontext2, gfp_flags);
854 if (!str) {
855 kfree(scontext2);
856 return -ENOMEM;
857 }
858 }
859
860 read_lock(&policy_rwlock);
861 rc = string_to_context_struct(&policydb, &sidtab,
862 scontext2, scontext_len,
863 &context, def_sid);
864 if (rc == -EINVAL && force) {
865 context.str = str;
866 context.len = scontext_len;
867 str = NULL;
868 } else if (rc)
869 goto out;
870 rc = sidtab_context_to_sid(&sidtab, &context, sid);
871 if (rc)
872 context_destroy(&context);
873 out:
874 read_unlock(&policy_rwlock);
875 kfree(scontext2);
876 kfree(str);
877 return rc;
878 }
879
880 /**
881 * security_context_to_sid - Obtain a SID for a given security context.
882 * @scontext: security context
883 * @scontext_len: length in bytes
884 * @sid: security identifier, SID
885 *
886 * Obtains a SID associated with the security context that
887 * has the string representation specified by @scontext.
888 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
889 * memory is available, or 0 on success.
890 */
891 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
892 {
893 return security_context_to_sid_core(scontext, scontext_len,
894 sid, SECSID_NULL, GFP_KERNEL, 0);
895 }
896
897 /**
898 * security_context_to_sid_default - Obtain a SID for a given security context,
899 * falling back to specified default if needed.
900 *
901 * @scontext: security context
902 * @scontext_len: length in bytes
903 * @sid: security identifier, SID
904 * @def_sid: default SID to assign on error
905 *
906 * Obtains a SID associated with the security context that
907 * has the string representation specified by @scontext.
908 * The default SID is passed to the MLS layer to be used to allow
909 * kernel labeling of the MLS field if the MLS field is not present
910 * (for upgrading to MLS without full relabel).
911 * Implicitly forces adding of the context even if it cannot be mapped yet.
912 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
913 * memory is available, or 0 on success.
914 */
915 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
916 u32 *sid, u32 def_sid, gfp_t gfp_flags)
917 {
918 return security_context_to_sid_core(scontext, scontext_len,
919 sid, def_sid, gfp_flags, 1);
920 }
921
922 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
923 u32 *sid)
924 {
925 return security_context_to_sid_core(scontext, scontext_len,
926 sid, SECSID_NULL, GFP_KERNEL, 1);
927 }
928
929 static int compute_sid_handle_invalid_context(
930 struct context *scontext,
931 struct context *tcontext,
932 u16 tclass,
933 struct context *newcontext)
934 {
935 char *s = NULL, *t = NULL, *n = NULL;
936 u32 slen, tlen, nlen;
937
938 if (context_struct_to_string(scontext, &s, &slen) < 0)
939 goto out;
940 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
941 goto out;
942 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
943 goto out;
944 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
945 "security_compute_sid: invalid context %s"
946 " for scontext=%s"
947 " tcontext=%s"
948 " tclass=%s",
949 n, s, t, policydb.p_class_val_to_name[tclass-1]);
950 out:
951 kfree(s);
952 kfree(t);
953 kfree(n);
954 if (!selinux_enforcing)
955 return 0;
956 return -EACCES;
957 }
958
959 static int security_compute_sid(u32 ssid,
960 u32 tsid,
961 u16 tclass,
962 u32 specified,
963 u32 *out_sid)
964 {
965 struct context *scontext = NULL, *tcontext = NULL, newcontext;
966 struct role_trans *roletr = NULL;
967 struct avtab_key avkey;
968 struct avtab_datum *avdatum;
969 struct avtab_node *node;
970 int rc = 0;
971
972 if (!ss_initialized) {
973 switch (tclass) {
974 case SECCLASS_PROCESS:
975 *out_sid = ssid;
976 break;
977 default:
978 *out_sid = tsid;
979 break;
980 }
981 goto out;
982 }
983
984 context_init(&newcontext);
985
986 read_lock(&policy_rwlock);
987
988 scontext = sidtab_search(&sidtab, ssid);
989 if (!scontext) {
990 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
991 __func__, ssid);
992 rc = -EINVAL;
993 goto out_unlock;
994 }
995 tcontext = sidtab_search(&sidtab, tsid);
996 if (!tcontext) {
997 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
998 __func__, tsid);
999 rc = -EINVAL;
1000 goto out_unlock;
1001 }
1002
1003 /* Set the user identity. */
1004 switch (specified) {
1005 case AVTAB_TRANSITION:
1006 case AVTAB_CHANGE:
1007 /* Use the process user identity. */
1008 newcontext.user = scontext->user;
1009 break;
1010 case AVTAB_MEMBER:
1011 /* Use the related object owner. */
1012 newcontext.user = tcontext->user;
1013 break;
1014 }
1015
1016 /* Set the role and type to default values. */
1017 switch (tclass) {
1018 case SECCLASS_PROCESS:
1019 /* Use the current role and type of process. */
1020 newcontext.role = scontext->role;
1021 newcontext.type = scontext->type;
1022 break;
1023 default:
1024 /* Use the well-defined object role. */
1025 newcontext.role = OBJECT_R_VAL;
1026 /* Use the type of the related object. */
1027 newcontext.type = tcontext->type;
1028 }
1029
1030 /* Look for a type transition/member/change rule. */
1031 avkey.source_type = scontext->type;
1032 avkey.target_type = tcontext->type;
1033 avkey.target_class = tclass;
1034 avkey.specified = specified;
1035 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1036
1037 /* If no permanent rule, also check for enabled conditional rules */
1038 if (!avdatum) {
1039 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1040 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
1041 if (node->key.specified & AVTAB_ENABLED) {
1042 avdatum = &node->datum;
1043 break;
1044 }
1045 }
1046 }
1047
1048 if (avdatum) {
1049 /* Use the type from the type transition/member/change rule. */
1050 newcontext.type = avdatum->data;
1051 }
1052
1053 /* Check for class-specific changes. */
1054 switch (tclass) {
1055 case SECCLASS_PROCESS:
1056 if (specified & AVTAB_TRANSITION) {
1057 /* Look for a role transition rule. */
1058 for (roletr = policydb.role_tr; roletr;
1059 roletr = roletr->next) {
1060 if (roletr->role == scontext->role &&
1061 roletr->type == tcontext->type) {
1062 /* Use the role transition rule. */
1063 newcontext.role = roletr->new_role;
1064 break;
1065 }
1066 }
1067 }
1068 break;
1069 default:
1070 break;
1071 }
1072
1073 /* Set the MLS attributes.
1074 This is done last because it may allocate memory. */
1075 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1076 if (rc)
1077 goto out_unlock;
1078
1079 /* Check the validity of the context. */
1080 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1081 rc = compute_sid_handle_invalid_context(scontext,
1082 tcontext,
1083 tclass,
1084 &newcontext);
1085 if (rc)
1086 goto out_unlock;
1087 }
1088 /* Obtain the sid for the context. */
1089 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1090 out_unlock:
1091 read_unlock(&policy_rwlock);
1092 context_destroy(&newcontext);
1093 out:
1094 return rc;
1095 }
1096
1097 /**
1098 * security_transition_sid - Compute the SID for a new subject/object.
1099 * @ssid: source security identifier
1100 * @tsid: target security identifier
1101 * @tclass: target security class
1102 * @out_sid: security identifier for new subject/object
1103 *
1104 * Compute a SID to use for labeling a new subject or object in the
1105 * class @tclass based on a SID pair (@ssid, @tsid).
1106 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1107 * if insufficient memory is available, or %0 if the new SID was
1108 * computed successfully.
1109 */
1110 int security_transition_sid(u32 ssid,
1111 u32 tsid,
1112 u16 tclass,
1113 u32 *out_sid)
1114 {
1115 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1116 }
1117
1118 /**
1119 * security_member_sid - Compute the SID for member selection.
1120 * @ssid: source security identifier
1121 * @tsid: target security identifier
1122 * @tclass: target security class
1123 * @out_sid: security identifier for selected member
1124 *
1125 * Compute a SID to use when selecting a member of a polyinstantiated
1126 * object of class @tclass based on a SID pair (@ssid, @tsid).
1127 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1128 * if insufficient memory is available, or %0 if the SID was
1129 * computed successfully.
1130 */
1131 int security_member_sid(u32 ssid,
1132 u32 tsid,
1133 u16 tclass,
1134 u32 *out_sid)
1135 {
1136 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1137 }
1138
1139 /**
1140 * security_change_sid - Compute the SID for object relabeling.
1141 * @ssid: source security identifier
1142 * @tsid: target security identifier
1143 * @tclass: target security class
1144 * @out_sid: security identifier for selected member
1145 *
1146 * Compute a SID to use for relabeling an object of class @tclass
1147 * based on a SID pair (@ssid, @tsid).
1148 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1149 * if insufficient memory is available, or %0 if the SID was
1150 * computed successfully.
1151 */
1152 int security_change_sid(u32 ssid,
1153 u32 tsid,
1154 u16 tclass,
1155 u32 *out_sid)
1156 {
1157 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1158 }
1159
1160 /*
1161 * Verify that each kernel class that is defined in the
1162 * policy is correct
1163 */
1164 static int validate_classes(struct policydb *p)
1165 {
1166 int i, j;
1167 struct class_datum *cladatum;
1168 struct perm_datum *perdatum;
1169 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1170 u16 class_val;
1171 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1172 const char *def_class, *def_perm, *pol_class;
1173 struct symtab *perms;
1174 bool print_unknown_handle = 0;
1175
1176 if (p->allow_unknown) {
1177 u32 num_classes = kdefs->cts_len;
1178 p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1179 if (!p->undefined_perms)
1180 return -ENOMEM;
1181 }
1182
1183 for (i = 1; i < kdefs->cts_len; i++) {
1184 def_class = kdefs->class_to_string[i];
1185 if (!def_class)
1186 continue;
1187 if (i > p->p_classes.nprim) {
1188 printk(KERN_INFO
1189 "SELinux: class %s not defined in policy\n",
1190 def_class);
1191 if (p->reject_unknown)
1192 return -EINVAL;
1193 if (p->allow_unknown)
1194 p->undefined_perms[i-1] = ~0U;
1195 print_unknown_handle = 1;
1196 continue;
1197 }
1198 pol_class = p->p_class_val_to_name[i-1];
1199 if (strcmp(pol_class, def_class)) {
1200 printk(KERN_ERR
1201 "SELinux: class %d is incorrect, found %s but should be %s\n",
1202 i, pol_class, def_class);
1203 return -EINVAL;
1204 }
1205 }
1206 for (i = 0; i < kdefs->av_pts_len; i++) {
1207 class_val = kdefs->av_perm_to_string[i].tclass;
1208 perm_val = kdefs->av_perm_to_string[i].value;
1209 def_perm = kdefs->av_perm_to_string[i].name;
1210 if (class_val > p->p_classes.nprim)
1211 continue;
1212 pol_class = p->p_class_val_to_name[class_val-1];
1213 cladatum = hashtab_search(p->p_classes.table, pol_class);
1214 BUG_ON(!cladatum);
1215 perms = &cladatum->permissions;
1216 nprim = 1 << (perms->nprim - 1);
1217 if (perm_val > nprim) {
1218 printk(KERN_INFO
1219 "SELinux: permission %s in class %s not defined in policy\n",
1220 def_perm, pol_class);
1221 if (p->reject_unknown)
1222 return -EINVAL;
1223 if (p->allow_unknown)
1224 p->undefined_perms[class_val-1] |= perm_val;
1225 print_unknown_handle = 1;
1226 continue;
1227 }
1228 perdatum = hashtab_search(perms->table, def_perm);
1229 if (perdatum == NULL) {
1230 printk(KERN_ERR
1231 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1232 def_perm, pol_class);
1233 return -EINVAL;
1234 }
1235 pol_val = 1 << (perdatum->value - 1);
1236 if (pol_val != perm_val) {
1237 printk(KERN_ERR
1238 "SELinux: permission %s in class %s has incorrect value\n",
1239 def_perm, pol_class);
1240 return -EINVAL;
1241 }
1242 }
1243 for (i = 0; i < kdefs->av_inherit_len; i++) {
1244 class_val = kdefs->av_inherit[i].tclass;
1245 if (class_val > p->p_classes.nprim)
1246 continue;
1247 pol_class = p->p_class_val_to_name[class_val-1];
1248 cladatum = hashtab_search(p->p_classes.table, pol_class);
1249 BUG_ON(!cladatum);
1250 if (!cladatum->comdatum) {
1251 printk(KERN_ERR
1252 "SELinux: class %s should have an inherits clause but does not\n",
1253 pol_class);
1254 return -EINVAL;
1255 }
1256 tmp = kdefs->av_inherit[i].common_base;
1257 common_pts_len = 0;
1258 while (!(tmp & 0x01)) {
1259 common_pts_len++;
1260 tmp >>= 1;
1261 }
1262 perms = &cladatum->comdatum->permissions;
1263 for (j = 0; j < common_pts_len; j++) {
1264 def_perm = kdefs->av_inherit[i].common_pts[j];
1265 if (j >= perms->nprim) {
1266 printk(KERN_INFO
1267 "SELinux: permission %s in class %s not defined in policy\n",
1268 def_perm, pol_class);
1269 if (p->reject_unknown)
1270 return -EINVAL;
1271 if (p->allow_unknown)
1272 p->undefined_perms[class_val-1] |= (1 << j);
1273 print_unknown_handle = 1;
1274 continue;
1275 }
1276 perdatum = hashtab_search(perms->table, def_perm);
1277 if (perdatum == NULL) {
1278 printk(KERN_ERR
1279 "SELinux: permission %s in class %s not found in policy, bad policy\n",
1280 def_perm, pol_class);
1281 return -EINVAL;
1282 }
1283 if (perdatum->value != j + 1) {
1284 printk(KERN_ERR
1285 "SELinux: permission %s in class %s has incorrect value\n",
1286 def_perm, pol_class);
1287 return -EINVAL;
1288 }
1289 }
1290 }
1291 if (print_unknown_handle)
1292 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
1293 (security_get_allow_unknown() ? "allowed" : "denied"));
1294 return 0;
1295 }
1296
1297 /* Clone the SID into the new SID table. */
1298 static int clone_sid(u32 sid,
1299 struct context *context,
1300 void *arg)
1301 {
1302 struct sidtab *s = arg;
1303
1304 return sidtab_insert(s, sid, context);
1305 }
1306
1307 static inline int convert_context_handle_invalid_context(struct context *context)
1308 {
1309 int rc = 0;
1310
1311 if (selinux_enforcing) {
1312 rc = -EINVAL;
1313 } else {
1314 char *s;
1315 u32 len;
1316
1317 if (!context_struct_to_string(context, &s, &len)) {
1318 printk(KERN_WARNING
1319 "SELinux: Context %s would be invalid if enforcing\n",
1320 s);
1321 kfree(s);
1322 }
1323 }
1324 return rc;
1325 }
1326
1327 struct convert_context_args {
1328 struct policydb *oldp;
1329 struct policydb *newp;
1330 };
1331
1332 /*
1333 * Convert the values in the security context
1334 * structure `c' from the values specified
1335 * in the policy `p->oldp' to the values specified
1336 * in the policy `p->newp'. Verify that the
1337 * context is valid under the new policy.
1338 */
1339 static int convert_context(u32 key,
1340 struct context *c,
1341 void *p)
1342 {
1343 struct convert_context_args *args;
1344 struct context oldc;
1345 struct role_datum *role;
1346 struct type_datum *typdatum;
1347 struct user_datum *usrdatum;
1348 char *s;
1349 u32 len;
1350 int rc;
1351
1352 args = p;
1353
1354 if (c->str) {
1355 struct context ctx;
1356 s = kstrdup(c->str, GFP_KERNEL);
1357 if (!s) {
1358 rc = -ENOMEM;
1359 goto out;
1360 }
1361 rc = string_to_context_struct(args->newp, NULL, s,
1362 c->len, &ctx, SECSID_NULL);
1363 kfree(s);
1364 if (!rc) {
1365 printk(KERN_INFO
1366 "SELinux: Context %s became valid (mapped).\n",
1367 c->str);
1368 /* Replace string with mapped representation. */
1369 kfree(c->str);
1370 memcpy(c, &ctx, sizeof(*c));
1371 goto out;
1372 } else if (rc == -EINVAL) {
1373 /* Retain string representation for later mapping. */
1374 rc = 0;
1375 goto out;
1376 } else {
1377 /* Other error condition, e.g. ENOMEM. */
1378 printk(KERN_ERR
1379 "SELinux: Unable to map context %s, rc = %d.\n",
1380 c->str, -rc);
1381 goto out;
1382 }
1383 }
1384
1385 rc = context_cpy(&oldc, c);
1386 if (rc)
1387 goto out;
1388
1389 rc = -EINVAL;
1390
1391 /* Convert the user. */
1392 usrdatum = hashtab_search(args->newp->p_users.table,
1393 args->oldp->p_user_val_to_name[c->user - 1]);
1394 if (!usrdatum)
1395 goto bad;
1396 c->user = usrdatum->value;
1397
1398 /* Convert the role. */
1399 role = hashtab_search(args->newp->p_roles.table,
1400 args->oldp->p_role_val_to_name[c->role - 1]);
1401 if (!role)
1402 goto bad;
1403 c->role = role->value;
1404
1405 /* Convert the type. */
1406 typdatum = hashtab_search(args->newp->p_types.table,
1407 args->oldp->p_type_val_to_name[c->type - 1]);
1408 if (!typdatum)
1409 goto bad;
1410 c->type = typdatum->value;
1411
1412 rc = mls_convert_context(args->oldp, args->newp, c);
1413 if (rc)
1414 goto bad;
1415
1416 /* Check the validity of the new context. */
1417 if (!policydb_context_isvalid(args->newp, c)) {
1418 rc = convert_context_handle_invalid_context(&oldc);
1419 if (rc)
1420 goto bad;
1421 }
1422
1423 context_destroy(&oldc);
1424 rc = 0;
1425 out:
1426 return rc;
1427 bad:
1428 /* Map old representation to string and save it. */
1429 if (context_struct_to_string(&oldc, &s, &len))
1430 return -ENOMEM;
1431 context_destroy(&oldc);
1432 context_destroy(c);
1433 c->str = s;
1434 c->len = len;
1435 printk(KERN_INFO
1436 "SELinux: Context %s became invalid (unmapped).\n",
1437 c->str);
1438 rc = 0;
1439 goto out;
1440 }
1441
1442 static void security_load_policycaps(void)
1443 {
1444 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1445 POLICYDB_CAPABILITY_NETPEER);
1446 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1447 POLICYDB_CAPABILITY_OPENPERM);
1448 }
1449
1450 extern void selinux_complete_init(void);
1451 static int security_preserve_bools(struct policydb *p);
1452
1453 /**
1454 * security_load_policy - Load a security policy configuration.
1455 * @data: binary policy data
1456 * @len: length of data in bytes
1457 *
1458 * Load a new set of security policy configuration data,
1459 * validate it and convert the SID table as necessary.
1460 * This function will flush the access vector cache after
1461 * loading the new policy.
1462 */
1463 int security_load_policy(void *data, size_t len)
1464 {
1465 struct policydb oldpolicydb, newpolicydb;
1466 struct sidtab oldsidtab, newsidtab;
1467 struct convert_context_args args;
1468 u32 seqno;
1469 int rc = 0;
1470 struct policy_file file = { data, len }, *fp = &file;
1471
1472 if (!ss_initialized) {
1473 avtab_cache_init();
1474 if (policydb_read(&policydb, fp)) {
1475 avtab_cache_destroy();
1476 return -EINVAL;
1477 }
1478 if (policydb_load_isids(&policydb, &sidtab)) {
1479 policydb_destroy(&policydb);
1480 avtab_cache_destroy();
1481 return -EINVAL;
1482 }
1483 /* Verify that the kernel defined classes are correct. */
1484 if (validate_classes(&policydb)) {
1485 printk(KERN_ERR
1486 "SELinux: the definition of a class is incorrect\n");
1487 sidtab_destroy(&sidtab);
1488 policydb_destroy(&policydb);
1489 avtab_cache_destroy();
1490 return -EINVAL;
1491 }
1492 security_load_policycaps();
1493 policydb_loaded_version = policydb.policyvers;
1494 ss_initialized = 1;
1495 seqno = ++latest_granting;
1496 selinux_complete_init();
1497 avc_ss_reset(seqno);
1498 selnl_notify_policyload(seqno);
1499 selinux_netlbl_cache_invalidate();
1500 selinux_xfrm_notify_policyload();
1501 return 0;
1502 }
1503
1504 #if 0
1505 sidtab_hash_eval(&sidtab, "sids");
1506 #endif
1507
1508 if (policydb_read(&newpolicydb, fp))
1509 return -EINVAL;
1510
1511 if (sidtab_init(&newsidtab)) {
1512 policydb_destroy(&newpolicydb);
1513 return -ENOMEM;
1514 }
1515
1516 /* Verify that the kernel defined classes are correct. */
1517 if (validate_classes(&newpolicydb)) {
1518 printk(KERN_ERR
1519 "SELinux: the definition of a class is incorrect\n");
1520 rc = -EINVAL;
1521 goto err;
1522 }
1523
1524 rc = security_preserve_bools(&newpolicydb);
1525 if (rc) {
1526 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1527 goto err;
1528 }
1529
1530 /* Clone the SID table. */
1531 sidtab_shutdown(&sidtab);
1532 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1533 rc = -ENOMEM;
1534 goto err;
1535 }
1536
1537 /*
1538 * Convert the internal representations of contexts
1539 * in the new SID table.
1540 */
1541 args.oldp = &policydb;
1542 args.newp = &newpolicydb;
1543 rc = sidtab_map(&newsidtab, convert_context, &args);
1544 if (rc)
1545 goto err;
1546
1547 /* Save the old policydb and SID table to free later. */
1548 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1549 sidtab_set(&oldsidtab, &sidtab);
1550
1551 /* Install the new policydb and SID table. */
1552 write_lock_irq(&policy_rwlock);
1553 memcpy(&policydb, &newpolicydb, sizeof policydb);
1554 sidtab_set(&sidtab, &newsidtab);
1555 security_load_policycaps();
1556 seqno = ++latest_granting;
1557 policydb_loaded_version = policydb.policyvers;
1558 write_unlock_irq(&policy_rwlock);
1559
1560 /* Free the old policydb and SID table. */
1561 policydb_destroy(&oldpolicydb);
1562 sidtab_destroy(&oldsidtab);
1563
1564 avc_ss_reset(seqno);
1565 selnl_notify_policyload(seqno);
1566 selinux_netlbl_cache_invalidate();
1567 selinux_xfrm_notify_policyload();
1568
1569 return 0;
1570
1571 err:
1572 sidtab_destroy(&newsidtab);
1573 policydb_destroy(&newpolicydb);
1574 return rc;
1575
1576 }
1577
1578 /**
1579 * security_port_sid - Obtain the SID for a port.
1580 * @protocol: protocol number
1581 * @port: port number
1582 * @out_sid: security identifier
1583 */
1584 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1585 {
1586 struct ocontext *c;
1587 int rc = 0;
1588
1589 read_lock(&policy_rwlock);
1590
1591 c = policydb.ocontexts[OCON_PORT];
1592 while (c) {
1593 if (c->u.port.protocol == protocol &&
1594 c->u.port.low_port <= port &&
1595 c->u.port.high_port >= port)
1596 break;
1597 c = c->next;
1598 }
1599
1600 if (c) {
1601 if (!c->sid[0]) {
1602 rc = sidtab_context_to_sid(&sidtab,
1603 &c->context[0],
1604 &c->sid[0]);
1605 if (rc)
1606 goto out;
1607 }
1608 *out_sid = c->sid[0];
1609 } else {
1610 *out_sid = SECINITSID_PORT;
1611 }
1612
1613 out:
1614 read_unlock(&policy_rwlock);
1615 return rc;
1616 }
1617
1618 /**
1619 * security_netif_sid - Obtain the SID for a network interface.
1620 * @name: interface name
1621 * @if_sid: interface SID
1622 */
1623 int security_netif_sid(char *name, u32 *if_sid)
1624 {
1625 int rc = 0;
1626 struct ocontext *c;
1627
1628 read_lock(&policy_rwlock);
1629
1630 c = policydb.ocontexts[OCON_NETIF];
1631 while (c) {
1632 if (strcmp(name, c->u.name) == 0)
1633 break;
1634 c = c->next;
1635 }
1636
1637 if (c) {
1638 if (!c->sid[0] || !c->sid[1]) {
1639 rc = sidtab_context_to_sid(&sidtab,
1640 &c->context[0],
1641 &c->sid[0]);
1642 if (rc)
1643 goto out;
1644 rc = sidtab_context_to_sid(&sidtab,
1645 &c->context[1],
1646 &c->sid[1]);
1647 if (rc)
1648 goto out;
1649 }
1650 *if_sid = c->sid[0];
1651 } else
1652 *if_sid = SECINITSID_NETIF;
1653
1654 out:
1655 read_unlock(&policy_rwlock);
1656 return rc;
1657 }
1658
1659 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1660 {
1661 int i, fail = 0;
1662
1663 for (i = 0; i < 4; i++)
1664 if (addr[i] != (input[i] & mask[i])) {
1665 fail = 1;
1666 break;
1667 }
1668
1669 return !fail;
1670 }
1671
1672 /**
1673 * security_node_sid - Obtain the SID for a node (host).
1674 * @domain: communication domain aka address family
1675 * @addrp: address
1676 * @addrlen: address length in bytes
1677 * @out_sid: security identifier
1678 */
1679 int security_node_sid(u16 domain,
1680 void *addrp,
1681 u32 addrlen,
1682 u32 *out_sid)
1683 {
1684 int rc = 0;
1685 struct ocontext *c;
1686
1687 read_lock(&policy_rwlock);
1688
1689 switch (domain) {
1690 case AF_INET: {
1691 u32 addr;
1692
1693 if (addrlen != sizeof(u32)) {
1694 rc = -EINVAL;
1695 goto out;
1696 }
1697
1698 addr = *((u32 *)addrp);
1699
1700 c = policydb.ocontexts[OCON_NODE];
1701 while (c) {
1702 if (c->u.node.addr == (addr & c->u.node.mask))
1703 break;
1704 c = c->next;
1705 }
1706 break;
1707 }
1708
1709 case AF_INET6:
1710 if (addrlen != sizeof(u64) * 2) {
1711 rc = -EINVAL;
1712 goto out;
1713 }
1714 c = policydb.ocontexts[OCON_NODE6];
1715 while (c) {
1716 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1717 c->u.node6.mask))
1718 break;
1719 c = c->next;
1720 }
1721 break;
1722
1723 default:
1724 *out_sid = SECINITSID_NODE;
1725 goto out;
1726 }
1727
1728 if (c) {
1729 if (!c->sid[0]) {
1730 rc = sidtab_context_to_sid(&sidtab,
1731 &c->context[0],
1732 &c->sid[0]);
1733 if (rc)
1734 goto out;
1735 }
1736 *out_sid = c->sid[0];
1737 } else {
1738 *out_sid = SECINITSID_NODE;
1739 }
1740
1741 out:
1742 read_unlock(&policy_rwlock);
1743 return rc;
1744 }
1745
1746 #define SIDS_NEL 25
1747
1748 /**
1749 * security_get_user_sids - Obtain reachable SIDs for a user.
1750 * @fromsid: starting SID
1751 * @username: username
1752 * @sids: array of reachable SIDs for user
1753 * @nel: number of elements in @sids
1754 *
1755 * Generate the set of SIDs for legal security contexts
1756 * for a given user that can be reached by @fromsid.
1757 * Set *@sids to point to a dynamically allocated
1758 * array containing the set of SIDs. Set *@nel to the
1759 * number of elements in the array.
1760 */
1761
1762 int security_get_user_sids(u32 fromsid,
1763 char *username,
1764 u32 **sids,
1765 u32 *nel)
1766 {
1767 struct context *fromcon, usercon;
1768 u32 *mysids = NULL, *mysids2, sid;
1769 u32 mynel = 0, maxnel = SIDS_NEL;
1770 struct user_datum *user;
1771 struct role_datum *role;
1772 struct ebitmap_node *rnode, *tnode;
1773 int rc = 0, i, j;
1774
1775 *sids = NULL;
1776 *nel = 0;
1777
1778 if (!ss_initialized)
1779 goto out;
1780
1781 read_lock(&policy_rwlock);
1782
1783 context_init(&usercon);
1784
1785 fromcon = sidtab_search(&sidtab, fromsid);
1786 if (!fromcon) {
1787 rc = -EINVAL;
1788 goto out_unlock;
1789 }
1790
1791 user = hashtab_search(policydb.p_users.table, username);
1792 if (!user) {
1793 rc = -EINVAL;
1794 goto out_unlock;
1795 }
1796 usercon.user = user->value;
1797
1798 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1799 if (!mysids) {
1800 rc = -ENOMEM;
1801 goto out_unlock;
1802 }
1803
1804 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1805 role = policydb.role_val_to_struct[i];
1806 usercon.role = i+1;
1807 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1808 usercon.type = j+1;
1809
1810 if (mls_setup_user_range(fromcon, user, &usercon))
1811 continue;
1812
1813 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1814 if (rc)
1815 goto out_unlock;
1816 if (mynel < maxnel) {
1817 mysids[mynel++] = sid;
1818 } else {
1819 maxnel += SIDS_NEL;
1820 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1821 if (!mysids2) {
1822 rc = -ENOMEM;
1823 goto out_unlock;
1824 }
1825 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1826 kfree(mysids);
1827 mysids = mysids2;
1828 mysids[mynel++] = sid;
1829 }
1830 }
1831 }
1832
1833 out_unlock:
1834 read_unlock(&policy_rwlock);
1835 if (rc || !mynel) {
1836 kfree(mysids);
1837 goto out;
1838 }
1839
1840 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1841 if (!mysids2) {
1842 rc = -ENOMEM;
1843 kfree(mysids);
1844 goto out;
1845 }
1846 for (i = 0, j = 0; i < mynel; i++) {
1847 rc = avc_has_perm_noaudit(fromsid, mysids[i],
1848 SECCLASS_PROCESS,
1849 PROCESS__TRANSITION, AVC_STRICT,
1850 NULL);
1851 if (!rc)
1852 mysids2[j++] = mysids[i];
1853 cond_resched();
1854 }
1855 rc = 0;
1856 kfree(mysids);
1857 *sids = mysids2;
1858 *nel = j;
1859 out:
1860 return rc;
1861 }
1862
1863 /**
1864 * security_genfs_sid - Obtain a SID for a file in a filesystem
1865 * @fstype: filesystem type
1866 * @path: path from root of mount
1867 * @sclass: file security class
1868 * @sid: SID for path
1869 *
1870 * Obtain a SID to use for a file in a filesystem that
1871 * cannot support xattr or use a fixed labeling behavior like
1872 * transition SIDs or task SIDs.
1873 */
1874 int security_genfs_sid(const char *fstype,
1875 char *path,
1876 u16 sclass,
1877 u32 *sid)
1878 {
1879 int len;
1880 struct genfs *genfs;
1881 struct ocontext *c;
1882 int rc = 0, cmp = 0;
1883
1884 while (path[0] == '/' && path[1] == '/')
1885 path++;
1886
1887 read_lock(&policy_rwlock);
1888
1889 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1890 cmp = strcmp(fstype, genfs->fstype);
1891 if (cmp <= 0)
1892 break;
1893 }
1894
1895 if (!genfs || cmp) {
1896 *sid = SECINITSID_UNLABELED;
1897 rc = -ENOENT;
1898 goto out;
1899 }
1900
1901 for (c = genfs->head; c; c = c->next) {
1902 len = strlen(c->u.name);
1903 if ((!c->v.sclass || sclass == c->v.sclass) &&
1904 (strncmp(c->u.name, path, len) == 0))
1905 break;
1906 }
1907
1908 if (!c) {
1909 *sid = SECINITSID_UNLABELED;
1910 rc = -ENOENT;
1911 goto out;
1912 }
1913
1914 if (!c->sid[0]) {
1915 rc = sidtab_context_to_sid(&sidtab,
1916 &c->context[0],
1917 &c->sid[0]);
1918 if (rc)
1919 goto out;
1920 }
1921
1922 *sid = c->sid[0];
1923 out:
1924 read_unlock(&policy_rwlock);
1925 return rc;
1926 }
1927
1928 /**
1929 * security_fs_use - Determine how to handle labeling for a filesystem.
1930 * @fstype: filesystem type
1931 * @behavior: labeling behavior
1932 * @sid: SID for filesystem (superblock)
1933 */
1934 int security_fs_use(
1935 const char *fstype,
1936 unsigned int *behavior,
1937 u32 *sid)
1938 {
1939 int rc = 0;
1940 struct ocontext *c;
1941
1942 read_lock(&policy_rwlock);
1943
1944 c = policydb.ocontexts[OCON_FSUSE];
1945 while (c) {
1946 if (strcmp(fstype, c->u.name) == 0)
1947 break;
1948 c = c->next;
1949 }
1950
1951 if (c) {
1952 *behavior = c->v.behavior;
1953 if (!c->sid[0]) {
1954 rc = sidtab_context_to_sid(&sidtab,
1955 &c->context[0],
1956 &c->sid[0]);
1957 if (rc)
1958 goto out;
1959 }
1960 *sid = c->sid[0];
1961 } else {
1962 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1963 if (rc) {
1964 *behavior = SECURITY_FS_USE_NONE;
1965 rc = 0;
1966 } else {
1967 *behavior = SECURITY_FS_USE_GENFS;
1968 }
1969 }
1970
1971 out:
1972 read_unlock(&policy_rwlock);
1973 return rc;
1974 }
1975
1976 int security_get_bools(int *len, char ***names, int **values)
1977 {
1978 int i, rc = -ENOMEM;
1979
1980 read_lock(&policy_rwlock);
1981 *names = NULL;
1982 *values = NULL;
1983
1984 *len = policydb.p_bools.nprim;
1985 if (!*len) {
1986 rc = 0;
1987 goto out;
1988 }
1989
1990 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
1991 if (!*names)
1992 goto err;
1993
1994 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1995 if (!*values)
1996 goto err;
1997
1998 for (i = 0; i < *len; i++) {
1999 size_t name_len;
2000 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2001 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2002 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2003 if (!(*names)[i])
2004 goto err;
2005 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2006 (*names)[i][name_len - 1] = 0;
2007 }
2008 rc = 0;
2009 out:
2010 read_unlock(&policy_rwlock);
2011 return rc;
2012 err:
2013 if (*names) {
2014 for (i = 0; i < *len; i++)
2015 kfree((*names)[i]);
2016 }
2017 kfree(*values);
2018 goto out;
2019 }
2020
2021
2022 int security_set_bools(int len, int *values)
2023 {
2024 int i, rc = 0;
2025 int lenp, seqno = 0;
2026 struct cond_node *cur;
2027
2028 write_lock_irq(&policy_rwlock);
2029
2030 lenp = policydb.p_bools.nprim;
2031 if (len != lenp) {
2032 rc = -EFAULT;
2033 goto out;
2034 }
2035
2036 for (i = 0; i < len; i++) {
2037 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2038 audit_log(current->audit_context, GFP_ATOMIC,
2039 AUDIT_MAC_CONFIG_CHANGE,
2040 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2041 policydb.p_bool_val_to_name[i],
2042 !!values[i],
2043 policydb.bool_val_to_struct[i]->state,
2044 audit_get_loginuid(current),
2045 audit_get_sessionid(current));
2046 }
2047 if (values[i])
2048 policydb.bool_val_to_struct[i]->state = 1;
2049 else
2050 policydb.bool_val_to_struct[i]->state = 0;
2051 }
2052
2053 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
2054 rc = evaluate_cond_node(&policydb, cur);
2055 if (rc)
2056 goto out;
2057 }
2058
2059 seqno = ++latest_granting;
2060
2061 out:
2062 write_unlock_irq(&policy_rwlock);
2063 if (!rc) {
2064 avc_ss_reset(seqno);
2065 selnl_notify_policyload(seqno);
2066 selinux_xfrm_notify_policyload();
2067 }
2068 return rc;
2069 }
2070
2071 int security_get_bool_value(int bool)
2072 {
2073 int rc = 0;
2074 int len;
2075
2076 read_lock(&policy_rwlock);
2077
2078 len = policydb.p_bools.nprim;
2079 if (bool >= len) {
2080 rc = -EFAULT;
2081 goto out;
2082 }
2083
2084 rc = policydb.bool_val_to_struct[bool]->state;
2085 out:
2086 read_unlock(&policy_rwlock);
2087 return rc;
2088 }
2089
2090 static int security_preserve_bools(struct policydb *p)
2091 {
2092 int rc, nbools = 0, *bvalues = NULL, i;
2093 char **bnames = NULL;
2094 struct cond_bool_datum *booldatum;
2095 struct cond_node *cur;
2096
2097 rc = security_get_bools(&nbools, &bnames, &bvalues);
2098 if (rc)
2099 goto out;
2100 for (i = 0; i < nbools; i++) {
2101 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2102 if (booldatum)
2103 booldatum->state = bvalues[i];
2104 }
2105 for (cur = p->cond_list; cur != NULL; cur = cur->next) {
2106 rc = evaluate_cond_node(p, cur);
2107 if (rc)
2108 goto out;
2109 }
2110
2111 out:
2112 if (bnames) {
2113 for (i = 0; i < nbools; i++)
2114 kfree(bnames[i]);
2115 }
2116 kfree(bnames);
2117 kfree(bvalues);
2118 return rc;
2119 }
2120
2121 /*
2122 * security_sid_mls_copy() - computes a new sid based on the given
2123 * sid and the mls portion of mls_sid.
2124 */
2125 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2126 {
2127 struct context *context1;
2128 struct context *context2;
2129 struct context newcon;
2130 char *s;
2131 u32 len;
2132 int rc = 0;
2133
2134 if (!ss_initialized || !selinux_mls_enabled) {
2135 *new_sid = sid;
2136 goto out;
2137 }
2138
2139 context_init(&newcon);
2140
2141 read_lock(&policy_rwlock);
2142 context1 = sidtab_search(&sidtab, sid);
2143 if (!context1) {
2144 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2145 __func__, sid);
2146 rc = -EINVAL;
2147 goto out_unlock;
2148 }
2149
2150 context2 = sidtab_search(&sidtab, mls_sid);
2151 if (!context2) {
2152 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2153 __func__, mls_sid);
2154 rc = -EINVAL;
2155 goto out_unlock;
2156 }
2157
2158 newcon.user = context1->user;
2159 newcon.role = context1->role;
2160 newcon.type = context1->type;
2161 rc = mls_context_cpy(&newcon, context2);
2162 if (rc)
2163 goto out_unlock;
2164
2165 /* Check the validity of the new context. */
2166 if (!policydb_context_isvalid(&policydb, &newcon)) {
2167 rc = convert_context_handle_invalid_context(&newcon);
2168 if (rc)
2169 goto bad;
2170 }
2171
2172 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2173 goto out_unlock;
2174
2175 bad:
2176 if (!context_struct_to_string(&newcon, &s, &len)) {
2177 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2178 "security_sid_mls_copy: invalid context %s", s);
2179 kfree(s);
2180 }
2181
2182 out_unlock:
2183 read_unlock(&policy_rwlock);
2184 context_destroy(&newcon);
2185 out:
2186 return rc;
2187 }
2188
2189 /**
2190 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2191 * @nlbl_sid: NetLabel SID
2192 * @nlbl_type: NetLabel labeling protocol type
2193 * @xfrm_sid: XFRM SID
2194 *
2195 * Description:
2196 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2197 * resolved into a single SID it is returned via @peer_sid and the function
2198 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2199 * returns a negative value. A table summarizing the behavior is below:
2200 *
2201 * | function return | @sid
2202 * ------------------------------+-----------------+-----------------
2203 * no peer labels | 0 | SECSID_NULL
2204 * single peer label | 0 | <peer_label>
2205 * multiple, consistent labels | 0 | <peer_label>
2206 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2207 *
2208 */
2209 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2210 u32 xfrm_sid,
2211 u32 *peer_sid)
2212 {
2213 int rc;
2214 struct context *nlbl_ctx;
2215 struct context *xfrm_ctx;
2216
2217 /* handle the common (which also happens to be the set of easy) cases
2218 * right away, these two if statements catch everything involving a
2219 * single or absent peer SID/label */
2220 if (xfrm_sid == SECSID_NULL) {
2221 *peer_sid = nlbl_sid;
2222 return 0;
2223 }
2224 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2225 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2226 * is present */
2227 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2228 *peer_sid = xfrm_sid;
2229 return 0;
2230 }
2231
2232 /* we don't need to check ss_initialized here since the only way both
2233 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2234 * security server was initialized and ss_initialized was true */
2235 if (!selinux_mls_enabled) {
2236 *peer_sid = SECSID_NULL;
2237 return 0;
2238 }
2239
2240 read_lock(&policy_rwlock);
2241
2242 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2243 if (!nlbl_ctx) {
2244 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2245 __func__, nlbl_sid);
2246 rc = -EINVAL;
2247 goto out_slowpath;
2248 }
2249 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2250 if (!xfrm_ctx) {
2251 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2252 __func__, xfrm_sid);
2253 rc = -EINVAL;
2254 goto out_slowpath;
2255 }
2256 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2257
2258 out_slowpath:
2259 read_unlock(&policy_rwlock);
2260 if (rc == 0)
2261 /* at present NetLabel SIDs/labels really only carry MLS
2262 * information so if the MLS portion of the NetLabel SID
2263 * matches the MLS portion of the labeled XFRM SID/label
2264 * then pass along the XFRM SID as it is the most
2265 * expressive */
2266 *peer_sid = xfrm_sid;
2267 else
2268 *peer_sid = SECSID_NULL;
2269 return rc;
2270 }
2271
2272 static int get_classes_callback(void *k, void *d, void *args)
2273 {
2274 struct class_datum *datum = d;
2275 char *name = k, **classes = args;
2276 int value = datum->value - 1;
2277
2278 classes[value] = kstrdup(name, GFP_ATOMIC);
2279 if (!classes[value])
2280 return -ENOMEM;
2281
2282 return 0;
2283 }
2284
2285 int security_get_classes(char ***classes, int *nclasses)
2286 {
2287 int rc = -ENOMEM;
2288
2289 read_lock(&policy_rwlock);
2290
2291 *nclasses = policydb.p_classes.nprim;
2292 *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2293 if (!*classes)
2294 goto out;
2295
2296 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2297 *classes);
2298 if (rc < 0) {
2299 int i;
2300 for (i = 0; i < *nclasses; i++)
2301 kfree((*classes)[i]);
2302 kfree(*classes);
2303 }
2304
2305 out:
2306 read_unlock(&policy_rwlock);
2307 return rc;
2308 }
2309
2310 static int get_permissions_callback(void *k, void *d, void *args)
2311 {
2312 struct perm_datum *datum = d;
2313 char *name = k, **perms = args;
2314 int value = datum->value - 1;
2315
2316 perms[value] = kstrdup(name, GFP_ATOMIC);
2317 if (!perms[value])
2318 return -ENOMEM;
2319
2320 return 0;
2321 }
2322
2323 int security_get_permissions(char *class, char ***perms, int *nperms)
2324 {
2325 int rc = -ENOMEM, i;
2326 struct class_datum *match;
2327
2328 read_lock(&policy_rwlock);
2329
2330 match = hashtab_search(policydb.p_classes.table, class);
2331 if (!match) {
2332 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2333 __func__, class);
2334 rc = -EINVAL;
2335 goto out;
2336 }
2337
2338 *nperms = match->permissions.nprim;
2339 *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2340 if (!*perms)
2341 goto out;
2342
2343 if (match->comdatum) {
2344 rc = hashtab_map(match->comdatum->permissions.table,
2345 get_permissions_callback, *perms);
2346 if (rc < 0)
2347 goto err;
2348 }
2349
2350 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2351 *perms);
2352 if (rc < 0)
2353 goto err;
2354
2355 out:
2356 read_unlock(&policy_rwlock);
2357 return rc;
2358
2359 err:
2360 read_unlock(&policy_rwlock);
2361 for (i = 0; i < *nperms; i++)
2362 kfree((*perms)[i]);
2363 kfree(*perms);
2364 return rc;
2365 }
2366
2367 int security_get_reject_unknown(void)
2368 {
2369 return policydb.reject_unknown;
2370 }
2371
2372 int security_get_allow_unknown(void)
2373 {
2374 return policydb.allow_unknown;
2375 }
2376
2377 /**
2378 * security_policycap_supported - Check for a specific policy capability
2379 * @req_cap: capability
2380 *
2381 * Description:
2382 * This function queries the currently loaded policy to see if it supports the
2383 * capability specified by @req_cap. Returns true (1) if the capability is
2384 * supported, false (0) if it isn't supported.
2385 *
2386 */
2387 int security_policycap_supported(unsigned int req_cap)
2388 {
2389 int rc;
2390
2391 read_lock(&policy_rwlock);
2392 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2393 read_unlock(&policy_rwlock);
2394
2395 return rc;
2396 }
2397
2398 struct selinux_audit_rule {
2399 u32 au_seqno;
2400 struct context au_ctxt;
2401 };
2402
2403 void selinux_audit_rule_free(void *vrule)
2404 {
2405 struct selinux_audit_rule *rule = vrule;
2406
2407 if (rule) {
2408 context_destroy(&rule->au_ctxt);
2409 kfree(rule);
2410 }
2411 }
2412
2413 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2414 {
2415 struct selinux_audit_rule *tmprule;
2416 struct role_datum *roledatum;
2417 struct type_datum *typedatum;
2418 struct user_datum *userdatum;
2419 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2420 int rc = 0;
2421
2422 *rule = NULL;
2423
2424 if (!ss_initialized)
2425 return -EOPNOTSUPP;
2426
2427 switch (field) {
2428 case AUDIT_SUBJ_USER:
2429 case AUDIT_SUBJ_ROLE:
2430 case AUDIT_SUBJ_TYPE:
2431 case AUDIT_OBJ_USER:
2432 case AUDIT_OBJ_ROLE:
2433 case AUDIT_OBJ_TYPE:
2434 /* only 'equals' and 'not equals' fit user, role, and type */
2435 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2436 return -EINVAL;
2437 break;
2438 case AUDIT_SUBJ_SEN:
2439 case AUDIT_SUBJ_CLR:
2440 case AUDIT_OBJ_LEV_LOW:
2441 case AUDIT_OBJ_LEV_HIGH:
2442 /* we do not allow a range, indicated by the presense of '-' */
2443 if (strchr(rulestr, '-'))
2444 return -EINVAL;
2445 break;
2446 default:
2447 /* only the above fields are valid */
2448 return -EINVAL;
2449 }
2450
2451 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2452 if (!tmprule)
2453 return -ENOMEM;
2454
2455 context_init(&tmprule->au_ctxt);
2456
2457 read_lock(&policy_rwlock);
2458
2459 tmprule->au_seqno = latest_granting;
2460
2461 switch (field) {
2462 case AUDIT_SUBJ_USER:
2463 case AUDIT_OBJ_USER:
2464 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2465 if (!userdatum)
2466 rc = -EINVAL;
2467 else
2468 tmprule->au_ctxt.user = userdatum->value;
2469 break;
2470 case AUDIT_SUBJ_ROLE:
2471 case AUDIT_OBJ_ROLE:
2472 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2473 if (!roledatum)
2474 rc = -EINVAL;
2475 else
2476 tmprule->au_ctxt.role = roledatum->value;
2477 break;
2478 case AUDIT_SUBJ_TYPE:
2479 case AUDIT_OBJ_TYPE:
2480 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2481 if (!typedatum)
2482 rc = -EINVAL;
2483 else
2484 tmprule->au_ctxt.type = typedatum->value;
2485 break;
2486 case AUDIT_SUBJ_SEN:
2487 case AUDIT_SUBJ_CLR:
2488 case AUDIT_OBJ_LEV_LOW:
2489 case AUDIT_OBJ_LEV_HIGH:
2490 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2491 break;
2492 }
2493
2494 read_unlock(&policy_rwlock);
2495
2496 if (rc) {
2497 selinux_audit_rule_free(tmprule);
2498 tmprule = NULL;
2499 }
2500
2501 *rule = tmprule;
2502
2503 return rc;
2504 }
2505
2506 /* Check to see if the rule contains any selinux fields */
2507 int selinux_audit_rule_known(struct audit_krule *rule)
2508 {
2509 int i;
2510
2511 for (i = 0; i < rule->field_count; i++) {
2512 struct audit_field *f = &rule->fields[i];
2513 switch (f->type) {
2514 case AUDIT_SUBJ_USER:
2515 case AUDIT_SUBJ_ROLE:
2516 case AUDIT_SUBJ_TYPE:
2517 case AUDIT_SUBJ_SEN:
2518 case AUDIT_SUBJ_CLR:
2519 case AUDIT_OBJ_USER:
2520 case AUDIT_OBJ_ROLE:
2521 case AUDIT_OBJ_TYPE:
2522 case AUDIT_OBJ_LEV_LOW:
2523 case AUDIT_OBJ_LEV_HIGH:
2524 return 1;
2525 }
2526 }
2527
2528 return 0;
2529 }
2530
2531 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2532 struct audit_context *actx)
2533 {
2534 struct context *ctxt;
2535 struct mls_level *level;
2536 struct selinux_audit_rule *rule = vrule;
2537 int match = 0;
2538
2539 if (!rule) {
2540 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2541 "selinux_audit_rule_match: missing rule\n");
2542 return -ENOENT;
2543 }
2544
2545 read_lock(&policy_rwlock);
2546
2547 if (rule->au_seqno < latest_granting) {
2548 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2549 "selinux_audit_rule_match: stale rule\n");
2550 match = -ESTALE;
2551 goto out;
2552 }
2553
2554 ctxt = sidtab_search(&sidtab, sid);
2555 if (!ctxt) {
2556 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2557 "selinux_audit_rule_match: unrecognized SID %d\n",
2558 sid);
2559 match = -ENOENT;
2560 goto out;
2561 }
2562
2563 /* a field/op pair that is not caught here will simply fall through
2564 without a match */
2565 switch (field) {
2566 case AUDIT_SUBJ_USER:
2567 case AUDIT_OBJ_USER:
2568 switch (op) {
2569 case AUDIT_EQUAL:
2570 match = (ctxt->user == rule->au_ctxt.user);
2571 break;
2572 case AUDIT_NOT_EQUAL:
2573 match = (ctxt->user != rule->au_ctxt.user);
2574 break;
2575 }
2576 break;
2577 case AUDIT_SUBJ_ROLE:
2578 case AUDIT_OBJ_ROLE:
2579 switch (op) {
2580 case AUDIT_EQUAL:
2581 match = (ctxt->role == rule->au_ctxt.role);
2582 break;
2583 case AUDIT_NOT_EQUAL:
2584 match = (ctxt->role != rule->au_ctxt.role);
2585 break;
2586 }
2587 break;
2588 case AUDIT_SUBJ_TYPE:
2589 case AUDIT_OBJ_TYPE:
2590 switch (op) {
2591 case AUDIT_EQUAL:
2592 match = (ctxt->type == rule->au_ctxt.type);
2593 break;
2594 case AUDIT_NOT_EQUAL:
2595 match = (ctxt->type != rule->au_ctxt.type);
2596 break;
2597 }
2598 break;
2599 case AUDIT_SUBJ_SEN:
2600 case AUDIT_SUBJ_CLR:
2601 case AUDIT_OBJ_LEV_LOW:
2602 case AUDIT_OBJ_LEV_HIGH:
2603 level = ((field == AUDIT_SUBJ_SEN ||
2604 field == AUDIT_OBJ_LEV_LOW) ?
2605 &ctxt->range.level[0] : &ctxt->range.level[1]);
2606 switch (op) {
2607 case AUDIT_EQUAL:
2608 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2609 level);
2610 break;
2611 case AUDIT_NOT_EQUAL:
2612 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2613 level);
2614 break;
2615 case AUDIT_LESS_THAN:
2616 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2617 level) &&
2618 !mls_level_eq(&rule->au_ctxt.range.level[0],
2619 level));
2620 break;
2621 case AUDIT_LESS_THAN_OR_EQUAL:
2622 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2623 level);
2624 break;
2625 case AUDIT_GREATER_THAN:
2626 match = (mls_level_dom(level,
2627 &rule->au_ctxt.range.level[0]) &&
2628 !mls_level_eq(level,
2629 &rule->au_ctxt.range.level[0]));
2630 break;
2631 case AUDIT_GREATER_THAN_OR_EQUAL:
2632 match = mls_level_dom(level,
2633 &rule->au_ctxt.range.level[0]);
2634 break;
2635 }
2636 }
2637
2638 out:
2639 read_unlock(&policy_rwlock);
2640 return match;
2641 }
2642
2643 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2644
2645 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2646 u16 class, u32 perms, u32 *retained)
2647 {
2648 int err = 0;
2649
2650 if (event == AVC_CALLBACK_RESET && aurule_callback)
2651 err = aurule_callback();
2652 return err;
2653 }
2654
2655 static int __init aurule_init(void)
2656 {
2657 int err;
2658
2659 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2660 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2661 if (err)
2662 panic("avc_add_callback() failed, error %d\n", err);
2663
2664 return err;
2665 }
2666 __initcall(aurule_init);
2667
2668 #ifdef CONFIG_NETLABEL
2669 /**
2670 * security_netlbl_cache_add - Add an entry to the NetLabel cache
2671 * @secattr: the NetLabel packet security attributes
2672 * @sid: the SELinux SID
2673 *
2674 * Description:
2675 * Attempt to cache the context in @ctx, which was derived from the packet in
2676 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
2677 * already been initialized.
2678 *
2679 */
2680 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2681 u32 sid)
2682 {
2683 u32 *sid_cache;
2684
2685 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2686 if (sid_cache == NULL)
2687 return;
2688 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2689 if (secattr->cache == NULL) {
2690 kfree(sid_cache);
2691 return;
2692 }
2693
2694 *sid_cache = sid;
2695 secattr->cache->free = kfree;
2696 secattr->cache->data = sid_cache;
2697 secattr->flags |= NETLBL_SECATTR_CACHE;
2698 }
2699
2700 /**
2701 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2702 * @secattr: the NetLabel packet security attributes
2703 * @sid: the SELinux SID
2704 *
2705 * Description:
2706 * Convert the given NetLabel security attributes in @secattr into a
2707 * SELinux SID. If the @secattr field does not contain a full SELinux
2708 * SID/context then use SECINITSID_NETMSG as the foundation. If possibile the
2709 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2710 * allow the @secattr to be used by NetLabel to cache the secattr to SID
2711 * conversion for future lookups. Returns zero on success, negative values on
2712 * failure.
2713 *
2714 */
2715 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2716 u32 *sid)
2717 {
2718 int rc = -EIDRM;
2719 struct context *ctx;
2720 struct context ctx_new;
2721
2722 if (!ss_initialized) {
2723 *sid = SECSID_NULL;
2724 return 0;
2725 }
2726
2727 read_lock(&policy_rwlock);
2728
2729 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2730 *sid = *(u32 *)secattr->cache->data;
2731 rc = 0;
2732 } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2733 *sid = secattr->attr.secid;
2734 rc = 0;
2735 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2736 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2737 if (ctx == NULL)
2738 goto netlbl_secattr_to_sid_return;
2739
2740 ctx_new.user = ctx->user;
2741 ctx_new.role = ctx->role;
2742 ctx_new.type = ctx->type;
2743 mls_import_netlbl_lvl(&ctx_new, secattr);
2744 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2745 if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2746 secattr->attr.mls.cat) != 0)
2747 goto netlbl_secattr_to_sid_return;
2748 ctx_new.range.level[1].cat.highbit =
2749 ctx_new.range.level[0].cat.highbit;
2750 ctx_new.range.level[1].cat.node =
2751 ctx_new.range.level[0].cat.node;
2752 } else {
2753 ebitmap_init(&ctx_new.range.level[0].cat);
2754 ebitmap_init(&ctx_new.range.level[1].cat);
2755 }
2756 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2757 goto netlbl_secattr_to_sid_return_cleanup;
2758
2759 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2760 if (rc != 0)
2761 goto netlbl_secattr_to_sid_return_cleanup;
2762
2763 security_netlbl_cache_add(secattr, *sid);
2764
2765 ebitmap_destroy(&ctx_new.range.level[0].cat);
2766 } else {
2767 *sid = SECSID_NULL;
2768 rc = 0;
2769 }
2770
2771 netlbl_secattr_to_sid_return:
2772 read_unlock(&policy_rwlock);
2773 return rc;
2774 netlbl_secattr_to_sid_return_cleanup:
2775 ebitmap_destroy(&ctx_new.range.level[0].cat);
2776 goto netlbl_secattr_to_sid_return;
2777 }
2778
2779 /**
2780 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2781 * @sid: the SELinux SID
2782 * @secattr: the NetLabel packet security attributes
2783 *
2784 * Description:
2785 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2786 * Returns zero on success, negative values on failure.
2787 *
2788 */
2789 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2790 {
2791 int rc = -ENOENT;
2792 struct context *ctx;
2793
2794 if (!ss_initialized)
2795 return 0;
2796
2797 read_lock(&policy_rwlock);
2798 ctx = sidtab_search(&sidtab, sid);
2799 if (ctx == NULL)
2800 goto netlbl_sid_to_secattr_failure;
2801 secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2802 GFP_ATOMIC);
2803 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY;
2804 mls_export_netlbl_lvl(ctx, secattr);
2805 rc = mls_export_netlbl_cat(ctx, secattr);
2806 if (rc != 0)
2807 goto netlbl_sid_to_secattr_failure;
2808 read_unlock(&policy_rwlock);
2809
2810 return 0;
2811
2812 netlbl_sid_to_secattr_failure:
2813 read_unlock(&policy_rwlock);
2814 return rc;
2815 }
2816 #endif /* CONFIG_NETLABEL */
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