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1f5bbb246d28a84333340d46df44f3ef9cfb858c
[deliverable/linux.git] / security / selinux / ss / services.c
1 /*
2 * Implementation of the security services.
3 *
4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5 * James Morris <jmorris@redhat.com>
6 *
7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8 *
9 * Support for enhanced MLS infrastructure.
10 * Support for context based audit filters.
11 *
12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13 *
14 * Added conditional policy language extensions
15 *
16 * Updated: Hewlett-Packard <paul.moore@hp.com>
17 *
18 * Added support for NetLabel
19 *
20 * Updated: Chad Sellers <csellers@tresys.com>
21 *
22 * Added validation of kernel classes and permissions
23 *
24 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
25 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
26 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
27 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
28 * This program is free software; you can redistribute it and/or modify
29 * it under the terms of the GNU General Public License as published by
30 * the Free Software Foundation, version 2.
31 */
32 #include <linux/kernel.h>
33 #include <linux/slab.h>
34 #include <linux/string.h>
35 #include <linux/spinlock.h>
36 #include <linux/errno.h>
37 #include <linux/in.h>
38 #include <linux/sched.h>
39 #include <linux/audit.h>
40 #include <linux/mutex.h>
41 #include <net/sock.h>
42 #include <net/netlabel.h>
43
44 #include "flask.h"
45 #include "avc.h"
46 #include "avc_ss.h"
47 #include "security.h"
48 #include "context.h"
49 #include "policydb.h"
50 #include "sidtab.h"
51 #include "services.h"
52 #include "conditional.h"
53 #include "mls.h"
54 #include "objsec.h"
55 #include "selinux_netlabel.h"
56
57 extern void selnl_notify_policyload(u32 seqno);
58 unsigned int policydb_loaded_version;
59
60 /*
61 * This is declared in avc.c
62 */
63 extern const struct selinux_class_perm selinux_class_perm;
64
65 static DEFINE_RWLOCK(policy_rwlock);
66 #define POLICY_RDLOCK read_lock(&policy_rwlock)
67 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
68 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
69 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
70
71 static DEFINE_MUTEX(load_mutex);
72 #define LOAD_LOCK mutex_lock(&load_mutex)
73 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
74
75 static struct sidtab sidtab;
76 struct policydb policydb;
77 int ss_initialized = 0;
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 = 0;
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 unsigned int i, j;
294
295 /*
296 * Remap extended Netlink classes for old policy versions.
297 * Do this here rather than socket_type_to_security_class()
298 * in case a newer policy version is loaded, allowing sockets
299 * to remain in the correct class.
300 */
301 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
302 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
303 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
304 tclass = SECCLASS_NETLINK_SOCKET;
305
306 if (!tclass || tclass > policydb.p_classes.nprim) {
307 printk(KERN_ERR "security_compute_av: unrecognized class %d\n",
308 tclass);
309 return -EINVAL;
310 }
311 tclass_datum = policydb.class_val_to_struct[tclass - 1];
312
313 /*
314 * Initialize the access vectors to the default values.
315 */
316 avd->allowed = 0;
317 avd->decided = 0xffffffff;
318 avd->auditallow = 0;
319 avd->auditdeny = 0xffffffff;
320 avd->seqno = latest_granting;
321
322 /*
323 * If a specific type enforcement rule was defined for
324 * this permission check, then use it.
325 */
326 avkey.target_class = tclass;
327 avkey.specified = AVTAB_AV;
328 sattr = &policydb.type_attr_map[scontext->type - 1];
329 tattr = &policydb.type_attr_map[tcontext->type - 1];
330 ebitmap_for_each_bit(sattr, snode, i) {
331 if (!ebitmap_node_get_bit(snode, i))
332 continue;
333 ebitmap_for_each_bit(tattr, tnode, j) {
334 if (!ebitmap_node_get_bit(tnode, j))
335 continue;
336 avkey.source_type = i + 1;
337 avkey.target_type = j + 1;
338 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
339 node != NULL;
340 node = avtab_search_node_next(node, avkey.specified)) {
341 if (node->key.specified == AVTAB_ALLOWED)
342 avd->allowed |= node->datum.data;
343 else if (node->key.specified == AVTAB_AUDITALLOW)
344 avd->auditallow |= node->datum.data;
345 else if (node->key.specified == AVTAB_AUDITDENY)
346 avd->auditdeny &= node->datum.data;
347 }
348
349 /* Check conditional av table for additional permissions */
350 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
351
352 }
353 }
354
355 /*
356 * Remove any permissions prohibited by a constraint (this includes
357 * the MLS policy).
358 */
359 constraint = tclass_datum->constraints;
360 while (constraint) {
361 if ((constraint->permissions & (avd->allowed)) &&
362 !constraint_expr_eval(scontext, tcontext, NULL,
363 constraint->expr)) {
364 avd->allowed = (avd->allowed) & ~(constraint->permissions);
365 }
366 constraint = constraint->next;
367 }
368
369 /*
370 * If checking process transition permission and the
371 * role is changing, then check the (current_role, new_role)
372 * pair.
373 */
374 if (tclass == SECCLASS_PROCESS &&
375 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
376 scontext->role != tcontext->role) {
377 for (ra = policydb.role_allow; ra; ra = ra->next) {
378 if (scontext->role == ra->role &&
379 tcontext->role == ra->new_role)
380 break;
381 }
382 if (!ra)
383 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
384 PROCESS__DYNTRANSITION);
385 }
386
387 return 0;
388 }
389
390 static int security_validtrans_handle_fail(struct context *ocontext,
391 struct context *ncontext,
392 struct context *tcontext,
393 u16 tclass)
394 {
395 char *o = NULL, *n = NULL, *t = NULL;
396 u32 olen, nlen, tlen;
397
398 if (context_struct_to_string(ocontext, &o, &olen) < 0)
399 goto out;
400 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
401 goto out;
402 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
403 goto out;
404 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
405 "security_validate_transition: denied for"
406 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
407 o, n, t, policydb.p_class_val_to_name[tclass-1]);
408 out:
409 kfree(o);
410 kfree(n);
411 kfree(t);
412
413 if (!selinux_enforcing)
414 return 0;
415 return -EPERM;
416 }
417
418 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
419 u16 tclass)
420 {
421 struct context *ocontext;
422 struct context *ncontext;
423 struct context *tcontext;
424 struct class_datum *tclass_datum;
425 struct constraint_node *constraint;
426 int rc = 0;
427
428 if (!ss_initialized)
429 return 0;
430
431 POLICY_RDLOCK;
432
433 /*
434 * Remap extended Netlink classes for old policy versions.
435 * Do this here rather than socket_type_to_security_class()
436 * in case a newer policy version is loaded, allowing sockets
437 * to remain in the correct class.
438 */
439 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
440 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
441 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
442 tclass = SECCLASS_NETLINK_SOCKET;
443
444 if (!tclass || tclass > policydb.p_classes.nprim) {
445 printk(KERN_ERR "security_validate_transition: "
446 "unrecognized class %d\n", tclass);
447 rc = -EINVAL;
448 goto out;
449 }
450 tclass_datum = policydb.class_val_to_struct[tclass - 1];
451
452 ocontext = sidtab_search(&sidtab, oldsid);
453 if (!ocontext) {
454 printk(KERN_ERR "security_validate_transition: "
455 " unrecognized SID %d\n", oldsid);
456 rc = -EINVAL;
457 goto out;
458 }
459
460 ncontext = sidtab_search(&sidtab, newsid);
461 if (!ncontext) {
462 printk(KERN_ERR "security_validate_transition: "
463 " unrecognized SID %d\n", newsid);
464 rc = -EINVAL;
465 goto out;
466 }
467
468 tcontext = sidtab_search(&sidtab, tasksid);
469 if (!tcontext) {
470 printk(KERN_ERR "security_validate_transition: "
471 " unrecognized SID %d\n", tasksid);
472 rc = -EINVAL;
473 goto out;
474 }
475
476 constraint = tclass_datum->validatetrans;
477 while (constraint) {
478 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
479 constraint->expr)) {
480 rc = security_validtrans_handle_fail(ocontext, ncontext,
481 tcontext, tclass);
482 goto out;
483 }
484 constraint = constraint->next;
485 }
486
487 out:
488 POLICY_RDUNLOCK;
489 return rc;
490 }
491
492 /**
493 * security_compute_av - Compute access vector decisions.
494 * @ssid: source security identifier
495 * @tsid: target security identifier
496 * @tclass: target security class
497 * @requested: requested permissions
498 * @avd: access vector decisions
499 *
500 * Compute a set of access vector decisions based on the
501 * SID pair (@ssid, @tsid) for the permissions in @tclass.
502 * Return -%EINVAL if any of the parameters are invalid or %0
503 * if the access vector decisions were computed successfully.
504 */
505 int security_compute_av(u32 ssid,
506 u32 tsid,
507 u16 tclass,
508 u32 requested,
509 struct av_decision *avd)
510 {
511 struct context *scontext = NULL, *tcontext = NULL;
512 int rc = 0;
513
514 if (!ss_initialized) {
515 avd->allowed = 0xffffffff;
516 avd->decided = 0xffffffff;
517 avd->auditallow = 0;
518 avd->auditdeny = 0xffffffff;
519 avd->seqno = latest_granting;
520 return 0;
521 }
522
523 POLICY_RDLOCK;
524
525 scontext = sidtab_search(&sidtab, ssid);
526 if (!scontext) {
527 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
528 ssid);
529 rc = -EINVAL;
530 goto out;
531 }
532 tcontext = sidtab_search(&sidtab, tsid);
533 if (!tcontext) {
534 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
535 tsid);
536 rc = -EINVAL;
537 goto out;
538 }
539
540 rc = context_struct_compute_av(scontext, tcontext, tclass,
541 requested, avd);
542 out:
543 POLICY_RDUNLOCK;
544 return rc;
545 }
546
547 /*
548 * Write the security context string representation of
549 * the context structure `context' into a dynamically
550 * allocated string of the correct size. Set `*scontext'
551 * to point to this string and set `*scontext_len' to
552 * the length of the string.
553 */
554 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
555 {
556 char *scontextp;
557
558 *scontext = NULL;
559 *scontext_len = 0;
560
561 /* Compute the size of the context. */
562 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
563 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
564 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
565 *scontext_len += mls_compute_context_len(context);
566
567 /* Allocate space for the context; caller must free this space. */
568 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
569 if (!scontextp) {
570 return -ENOMEM;
571 }
572 *scontext = scontextp;
573
574 /*
575 * Copy the user name, role name and type name into the context.
576 */
577 sprintf(scontextp, "%s:%s:%s",
578 policydb.p_user_val_to_name[context->user - 1],
579 policydb.p_role_val_to_name[context->role - 1],
580 policydb.p_type_val_to_name[context->type - 1]);
581 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
582 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
583 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
584
585 mls_sid_to_context(context, &scontextp);
586
587 *scontextp = 0;
588
589 return 0;
590 }
591
592 #include "initial_sid_to_string.h"
593
594 /**
595 * security_sid_to_context - Obtain a context for a given SID.
596 * @sid: security identifier, SID
597 * @scontext: security context
598 * @scontext_len: length in bytes
599 *
600 * Write the string representation of the context associated with @sid
601 * into a dynamically allocated string of the correct size. Set @scontext
602 * to point to this string and set @scontext_len to the length of the string.
603 */
604 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
605 {
606 struct context *context;
607 int rc = 0;
608
609 if (!ss_initialized) {
610 if (sid <= SECINITSID_NUM) {
611 char *scontextp;
612
613 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
614 scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
615 if (!scontextp) {
616 rc = -ENOMEM;
617 goto out;
618 }
619 strcpy(scontextp, initial_sid_to_string[sid]);
620 *scontext = scontextp;
621 goto out;
622 }
623 printk(KERN_ERR "security_sid_to_context: called before initial "
624 "load_policy on unknown SID %d\n", sid);
625 rc = -EINVAL;
626 goto out;
627 }
628 POLICY_RDLOCK;
629 context = sidtab_search(&sidtab, sid);
630 if (!context) {
631 printk(KERN_ERR "security_sid_to_context: unrecognized SID "
632 "%d\n", sid);
633 rc = -EINVAL;
634 goto out_unlock;
635 }
636 rc = context_struct_to_string(context, scontext, scontext_len);
637 out_unlock:
638 POLICY_RDUNLOCK;
639 out:
640 return rc;
641
642 }
643
644 static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
645 {
646 char *scontext2;
647 struct context context;
648 struct role_datum *role;
649 struct type_datum *typdatum;
650 struct user_datum *usrdatum;
651 char *scontextp, *p, oldc;
652 int rc = 0;
653
654 if (!ss_initialized) {
655 int i;
656
657 for (i = 1; i < SECINITSID_NUM; i++) {
658 if (!strcmp(initial_sid_to_string[i], scontext)) {
659 *sid = i;
660 goto out;
661 }
662 }
663 *sid = SECINITSID_KERNEL;
664 goto out;
665 }
666 *sid = SECSID_NULL;
667
668 /* Copy the string so that we can modify the copy as we parse it.
669 The string should already by null terminated, but we append a
670 null suffix to the copy to avoid problems with the existing
671 attr package, which doesn't view the null terminator as part
672 of the attribute value. */
673 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
674 if (!scontext2) {
675 rc = -ENOMEM;
676 goto out;
677 }
678 memcpy(scontext2, scontext, scontext_len);
679 scontext2[scontext_len] = 0;
680
681 context_init(&context);
682 *sid = SECSID_NULL;
683
684 POLICY_RDLOCK;
685
686 /* Parse the security context. */
687
688 rc = -EINVAL;
689 scontextp = (char *) scontext2;
690
691 /* Extract the user. */
692 p = scontextp;
693 while (*p && *p != ':')
694 p++;
695
696 if (*p == 0)
697 goto out_unlock;
698
699 *p++ = 0;
700
701 usrdatum = hashtab_search(policydb.p_users.table, scontextp);
702 if (!usrdatum)
703 goto out_unlock;
704
705 context.user = usrdatum->value;
706
707 /* Extract role. */
708 scontextp = p;
709 while (*p && *p != ':')
710 p++;
711
712 if (*p == 0)
713 goto out_unlock;
714
715 *p++ = 0;
716
717 role = hashtab_search(policydb.p_roles.table, scontextp);
718 if (!role)
719 goto out_unlock;
720 context.role = role->value;
721
722 /* Extract type. */
723 scontextp = p;
724 while (*p && *p != ':')
725 p++;
726 oldc = *p;
727 *p++ = 0;
728
729 typdatum = hashtab_search(policydb.p_types.table, scontextp);
730 if (!typdatum)
731 goto out_unlock;
732
733 context.type = typdatum->value;
734
735 rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
736 if (rc)
737 goto out_unlock;
738
739 if ((p - scontext2) < scontext_len) {
740 rc = -EINVAL;
741 goto out_unlock;
742 }
743
744 /* Check the validity of the new context. */
745 if (!policydb_context_isvalid(&policydb, &context)) {
746 rc = -EINVAL;
747 goto out_unlock;
748 }
749 /* Obtain the new sid. */
750 rc = sidtab_context_to_sid(&sidtab, &context, sid);
751 out_unlock:
752 POLICY_RDUNLOCK;
753 context_destroy(&context);
754 kfree(scontext2);
755 out:
756 return rc;
757 }
758
759 /**
760 * security_context_to_sid - Obtain a SID for a given security context.
761 * @scontext: security context
762 * @scontext_len: length in bytes
763 * @sid: security identifier, SID
764 *
765 * Obtains a SID associated with the security context that
766 * has the string representation specified by @scontext.
767 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
768 * memory is available, or 0 on success.
769 */
770 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
771 {
772 return security_context_to_sid_core(scontext, scontext_len,
773 sid, SECSID_NULL);
774 }
775
776 /**
777 * security_context_to_sid_default - Obtain a SID for a given security context,
778 * falling back to specified default if needed.
779 *
780 * @scontext: security context
781 * @scontext_len: length in bytes
782 * @sid: security identifier, SID
783 * @def_sid: default SID to assign on errror
784 *
785 * Obtains a SID associated with the security context that
786 * has the string representation specified by @scontext.
787 * The default SID is passed to the MLS layer to be used to allow
788 * kernel labeling of the MLS field if the MLS field is not present
789 * (for upgrading to MLS without full relabel).
790 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
791 * memory is available, or 0 on success.
792 */
793 int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
794 {
795 return security_context_to_sid_core(scontext, scontext_len,
796 sid, def_sid);
797 }
798
799 static int compute_sid_handle_invalid_context(
800 struct context *scontext,
801 struct context *tcontext,
802 u16 tclass,
803 struct context *newcontext)
804 {
805 char *s = NULL, *t = NULL, *n = NULL;
806 u32 slen, tlen, nlen;
807
808 if (context_struct_to_string(scontext, &s, &slen) < 0)
809 goto out;
810 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
811 goto out;
812 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
813 goto out;
814 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
815 "security_compute_sid: invalid context %s"
816 " for scontext=%s"
817 " tcontext=%s"
818 " tclass=%s",
819 n, s, t, policydb.p_class_val_to_name[tclass-1]);
820 out:
821 kfree(s);
822 kfree(t);
823 kfree(n);
824 if (!selinux_enforcing)
825 return 0;
826 return -EACCES;
827 }
828
829 static int security_compute_sid(u32 ssid,
830 u32 tsid,
831 u16 tclass,
832 u32 specified,
833 u32 *out_sid)
834 {
835 struct context *scontext = NULL, *tcontext = NULL, newcontext;
836 struct role_trans *roletr = NULL;
837 struct avtab_key avkey;
838 struct avtab_datum *avdatum;
839 struct avtab_node *node;
840 int rc = 0;
841
842 if (!ss_initialized) {
843 switch (tclass) {
844 case SECCLASS_PROCESS:
845 *out_sid = ssid;
846 break;
847 default:
848 *out_sid = tsid;
849 break;
850 }
851 goto out;
852 }
853
854 context_init(&newcontext);
855
856 POLICY_RDLOCK;
857
858 scontext = sidtab_search(&sidtab, ssid);
859 if (!scontext) {
860 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
861 ssid);
862 rc = -EINVAL;
863 goto out_unlock;
864 }
865 tcontext = sidtab_search(&sidtab, tsid);
866 if (!tcontext) {
867 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
868 tsid);
869 rc = -EINVAL;
870 goto out_unlock;
871 }
872
873 /* Set the user identity. */
874 switch (specified) {
875 case AVTAB_TRANSITION:
876 case AVTAB_CHANGE:
877 /* Use the process user identity. */
878 newcontext.user = scontext->user;
879 break;
880 case AVTAB_MEMBER:
881 /* Use the related object owner. */
882 newcontext.user = tcontext->user;
883 break;
884 }
885
886 /* Set the role and type to default values. */
887 switch (tclass) {
888 case SECCLASS_PROCESS:
889 /* Use the current role and type of process. */
890 newcontext.role = scontext->role;
891 newcontext.type = scontext->type;
892 break;
893 default:
894 /* Use the well-defined object role. */
895 newcontext.role = OBJECT_R_VAL;
896 /* Use the type of the related object. */
897 newcontext.type = tcontext->type;
898 }
899
900 /* Look for a type transition/member/change rule. */
901 avkey.source_type = scontext->type;
902 avkey.target_type = tcontext->type;
903 avkey.target_class = tclass;
904 avkey.specified = specified;
905 avdatum = avtab_search(&policydb.te_avtab, &avkey);
906
907 /* If no permanent rule, also check for enabled conditional rules */
908 if(!avdatum) {
909 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
910 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
911 if (node->key.specified & AVTAB_ENABLED) {
912 avdatum = &node->datum;
913 break;
914 }
915 }
916 }
917
918 if (avdatum) {
919 /* Use the type from the type transition/member/change rule. */
920 newcontext.type = avdatum->data;
921 }
922
923 /* Check for class-specific changes. */
924 switch (tclass) {
925 case SECCLASS_PROCESS:
926 if (specified & AVTAB_TRANSITION) {
927 /* Look for a role transition rule. */
928 for (roletr = policydb.role_tr; roletr;
929 roletr = roletr->next) {
930 if (roletr->role == scontext->role &&
931 roletr->type == tcontext->type) {
932 /* Use the role transition rule. */
933 newcontext.role = roletr->new_role;
934 break;
935 }
936 }
937 }
938 break;
939 default:
940 break;
941 }
942
943 /* Set the MLS attributes.
944 This is done last because it may allocate memory. */
945 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
946 if (rc)
947 goto out_unlock;
948
949 /* Check the validity of the context. */
950 if (!policydb_context_isvalid(&policydb, &newcontext)) {
951 rc = compute_sid_handle_invalid_context(scontext,
952 tcontext,
953 tclass,
954 &newcontext);
955 if (rc)
956 goto out_unlock;
957 }
958 /* Obtain the sid for the context. */
959 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
960 out_unlock:
961 POLICY_RDUNLOCK;
962 context_destroy(&newcontext);
963 out:
964 return rc;
965 }
966
967 /**
968 * security_transition_sid - Compute the SID for a new subject/object.
969 * @ssid: source security identifier
970 * @tsid: target security identifier
971 * @tclass: target security class
972 * @out_sid: security identifier for new subject/object
973 *
974 * Compute a SID to use for labeling a new subject or object in the
975 * class @tclass based on a SID pair (@ssid, @tsid).
976 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
977 * if insufficient memory is available, or %0 if the new SID was
978 * computed successfully.
979 */
980 int security_transition_sid(u32 ssid,
981 u32 tsid,
982 u16 tclass,
983 u32 *out_sid)
984 {
985 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
986 }
987
988 /**
989 * security_member_sid - Compute the SID for member selection.
990 * @ssid: source security identifier
991 * @tsid: target security identifier
992 * @tclass: target security class
993 * @out_sid: security identifier for selected member
994 *
995 * Compute a SID to use when selecting a member of a polyinstantiated
996 * object of class @tclass based on a SID pair (@ssid, @tsid).
997 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
998 * if insufficient memory is available, or %0 if the SID was
999 * computed successfully.
1000 */
1001 int security_member_sid(u32 ssid,
1002 u32 tsid,
1003 u16 tclass,
1004 u32 *out_sid)
1005 {
1006 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1007 }
1008
1009 /**
1010 * security_change_sid - Compute the SID for object relabeling.
1011 * @ssid: source security identifier
1012 * @tsid: target security identifier
1013 * @tclass: target security class
1014 * @out_sid: security identifier for selected member
1015 *
1016 * Compute a SID to use for relabeling an object of class @tclass
1017 * based on a SID pair (@ssid, @tsid).
1018 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1019 * if insufficient memory is available, or %0 if the SID was
1020 * computed successfully.
1021 */
1022 int security_change_sid(u32 ssid,
1023 u32 tsid,
1024 u16 tclass,
1025 u32 *out_sid)
1026 {
1027 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1028 }
1029
1030 /*
1031 * Verify that each kernel class that is defined in the
1032 * policy is correct
1033 */
1034 static int validate_classes(struct policydb *p)
1035 {
1036 int i, j;
1037 struct class_datum *cladatum;
1038 struct perm_datum *perdatum;
1039 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1040 u16 class_val;
1041 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1042 const char *def_class, *def_perm, *pol_class;
1043 struct symtab *perms;
1044
1045 for (i = 1; i < kdefs->cts_len; i++) {
1046 def_class = kdefs->class_to_string[i];
1047 if (i > p->p_classes.nprim) {
1048 printk(KERN_INFO
1049 "security: class %s not defined in policy\n",
1050 def_class);
1051 continue;
1052 }
1053 pol_class = p->p_class_val_to_name[i-1];
1054 if (strcmp(pol_class, def_class)) {
1055 printk(KERN_ERR
1056 "security: class %d is incorrect, found %s but should be %s\n",
1057 i, pol_class, def_class);
1058 return -EINVAL;
1059 }
1060 }
1061 for (i = 0; i < kdefs->av_pts_len; i++) {
1062 class_val = kdefs->av_perm_to_string[i].tclass;
1063 perm_val = kdefs->av_perm_to_string[i].value;
1064 def_perm = kdefs->av_perm_to_string[i].name;
1065 if (class_val > p->p_classes.nprim)
1066 continue;
1067 pol_class = p->p_class_val_to_name[class_val-1];
1068 cladatum = hashtab_search(p->p_classes.table, pol_class);
1069 BUG_ON(!cladatum);
1070 perms = &cladatum->permissions;
1071 nprim = 1 << (perms->nprim - 1);
1072 if (perm_val > nprim) {
1073 printk(KERN_INFO
1074 "security: permission %s in class %s not defined in policy\n",
1075 def_perm, pol_class);
1076 continue;
1077 }
1078 perdatum = hashtab_search(perms->table, def_perm);
1079 if (perdatum == NULL) {
1080 printk(KERN_ERR
1081 "security: permission %s in class %s not found in policy\n",
1082 def_perm, pol_class);
1083 return -EINVAL;
1084 }
1085 pol_val = 1 << (perdatum->value - 1);
1086 if (pol_val != perm_val) {
1087 printk(KERN_ERR
1088 "security: permission %s in class %s has incorrect value\n",
1089 def_perm, pol_class);
1090 return -EINVAL;
1091 }
1092 }
1093 for (i = 0; i < kdefs->av_inherit_len; i++) {
1094 class_val = kdefs->av_inherit[i].tclass;
1095 if (class_val > p->p_classes.nprim)
1096 continue;
1097 pol_class = p->p_class_val_to_name[class_val-1];
1098 cladatum = hashtab_search(p->p_classes.table, pol_class);
1099 BUG_ON(!cladatum);
1100 if (!cladatum->comdatum) {
1101 printk(KERN_ERR
1102 "security: class %s should have an inherits clause but does not\n",
1103 pol_class);
1104 return -EINVAL;
1105 }
1106 tmp = kdefs->av_inherit[i].common_base;
1107 common_pts_len = 0;
1108 while (!(tmp & 0x01)) {
1109 common_pts_len++;
1110 tmp >>= 1;
1111 }
1112 perms = &cladatum->comdatum->permissions;
1113 for (j = 0; j < common_pts_len; j++) {
1114 def_perm = kdefs->av_inherit[i].common_pts[j];
1115 if (j >= perms->nprim) {
1116 printk(KERN_INFO
1117 "security: permission %s in class %s not defined in policy\n",
1118 def_perm, pol_class);
1119 continue;
1120 }
1121 perdatum = hashtab_search(perms->table, def_perm);
1122 if (perdatum == NULL) {
1123 printk(KERN_ERR
1124 "security: permission %s in class %s not found in policy\n",
1125 def_perm, pol_class);
1126 return -EINVAL;
1127 }
1128 if (perdatum->value != j + 1) {
1129 printk(KERN_ERR
1130 "security: permission %s in class %s has incorrect value\n",
1131 def_perm, pol_class);
1132 return -EINVAL;
1133 }
1134 }
1135 }
1136 return 0;
1137 }
1138
1139 /* Clone the SID into the new SID table. */
1140 static int clone_sid(u32 sid,
1141 struct context *context,
1142 void *arg)
1143 {
1144 struct sidtab *s = arg;
1145
1146 return sidtab_insert(s, sid, context);
1147 }
1148
1149 static inline int convert_context_handle_invalid_context(struct context *context)
1150 {
1151 int rc = 0;
1152
1153 if (selinux_enforcing) {
1154 rc = -EINVAL;
1155 } else {
1156 char *s;
1157 u32 len;
1158
1159 context_struct_to_string(context, &s, &len);
1160 printk(KERN_ERR "security: context %s is invalid\n", s);
1161 kfree(s);
1162 }
1163 return rc;
1164 }
1165
1166 struct convert_context_args {
1167 struct policydb *oldp;
1168 struct policydb *newp;
1169 };
1170
1171 /*
1172 * Convert the values in the security context
1173 * structure `c' from the values specified
1174 * in the policy `p->oldp' to the values specified
1175 * in the policy `p->newp'. Verify that the
1176 * context is valid under the new policy.
1177 */
1178 static int convert_context(u32 key,
1179 struct context *c,
1180 void *p)
1181 {
1182 struct convert_context_args *args;
1183 struct context oldc;
1184 struct role_datum *role;
1185 struct type_datum *typdatum;
1186 struct user_datum *usrdatum;
1187 char *s;
1188 u32 len;
1189 int rc;
1190
1191 args = p;
1192
1193 rc = context_cpy(&oldc, c);
1194 if (rc)
1195 goto out;
1196
1197 rc = -EINVAL;
1198
1199 /* Convert the user. */
1200 usrdatum = hashtab_search(args->newp->p_users.table,
1201 args->oldp->p_user_val_to_name[c->user - 1]);
1202 if (!usrdatum) {
1203 goto bad;
1204 }
1205 c->user = usrdatum->value;
1206
1207 /* Convert the role. */
1208 role = hashtab_search(args->newp->p_roles.table,
1209 args->oldp->p_role_val_to_name[c->role - 1]);
1210 if (!role) {
1211 goto bad;
1212 }
1213 c->role = role->value;
1214
1215 /* Convert the type. */
1216 typdatum = hashtab_search(args->newp->p_types.table,
1217 args->oldp->p_type_val_to_name[c->type - 1]);
1218 if (!typdatum) {
1219 goto bad;
1220 }
1221 c->type = typdatum->value;
1222
1223 rc = mls_convert_context(args->oldp, args->newp, c);
1224 if (rc)
1225 goto bad;
1226
1227 /* Check the validity of the new context. */
1228 if (!policydb_context_isvalid(args->newp, c)) {
1229 rc = convert_context_handle_invalid_context(&oldc);
1230 if (rc)
1231 goto bad;
1232 }
1233
1234 context_destroy(&oldc);
1235 out:
1236 return rc;
1237 bad:
1238 context_struct_to_string(&oldc, &s, &len);
1239 context_destroy(&oldc);
1240 printk(KERN_ERR "security: invalidating context %s\n", s);
1241 kfree(s);
1242 goto out;
1243 }
1244
1245 extern void selinux_complete_init(void);
1246
1247 /**
1248 * security_load_policy - Load a security policy configuration.
1249 * @data: binary policy data
1250 * @len: length of data in bytes
1251 *
1252 * Load a new set of security policy configuration data,
1253 * validate it and convert the SID table as necessary.
1254 * This function will flush the access vector cache after
1255 * loading the new policy.
1256 */
1257 int security_load_policy(void *data, size_t len)
1258 {
1259 struct policydb oldpolicydb, newpolicydb;
1260 struct sidtab oldsidtab, newsidtab;
1261 struct convert_context_args args;
1262 u32 seqno;
1263 int rc = 0;
1264 struct policy_file file = { data, len }, *fp = &file;
1265
1266 LOAD_LOCK;
1267
1268 if (!ss_initialized) {
1269 avtab_cache_init();
1270 if (policydb_read(&policydb, fp)) {
1271 LOAD_UNLOCK;
1272 avtab_cache_destroy();
1273 return -EINVAL;
1274 }
1275 if (policydb_load_isids(&policydb, &sidtab)) {
1276 LOAD_UNLOCK;
1277 policydb_destroy(&policydb);
1278 avtab_cache_destroy();
1279 return -EINVAL;
1280 }
1281 /* Verify that the kernel defined classes are correct. */
1282 if (validate_classes(&policydb)) {
1283 printk(KERN_ERR
1284 "security: the definition of a class is incorrect\n");
1285 LOAD_UNLOCK;
1286 sidtab_destroy(&sidtab);
1287 policydb_destroy(&policydb);
1288 avtab_cache_destroy();
1289 return -EINVAL;
1290 }
1291 policydb_loaded_version = policydb.policyvers;
1292 ss_initialized = 1;
1293 seqno = ++latest_granting;
1294 LOAD_UNLOCK;
1295 selinux_complete_init();
1296 avc_ss_reset(seqno);
1297 selnl_notify_policyload(seqno);
1298 selinux_netlbl_cache_invalidate();
1299 return 0;
1300 }
1301
1302 #if 0
1303 sidtab_hash_eval(&sidtab, "sids");
1304 #endif
1305
1306 if (policydb_read(&newpolicydb, fp)) {
1307 LOAD_UNLOCK;
1308 return -EINVAL;
1309 }
1310
1311 sidtab_init(&newsidtab);
1312
1313 /* Verify that the kernel defined classes are correct. */
1314 if (validate_classes(&newpolicydb)) {
1315 printk(KERN_ERR
1316 "security: the definition of a class is incorrect\n");
1317 rc = -EINVAL;
1318 goto err;
1319 }
1320
1321 /* Clone the SID table. */
1322 sidtab_shutdown(&sidtab);
1323 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1324 rc = -ENOMEM;
1325 goto err;
1326 }
1327
1328 /* Convert the internal representations of contexts
1329 in the new SID table and remove invalid SIDs. */
1330 args.oldp = &policydb;
1331 args.newp = &newpolicydb;
1332 sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1333
1334 /* Save the old policydb and SID table to free later. */
1335 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1336 sidtab_set(&oldsidtab, &sidtab);
1337
1338 /* Install the new policydb and SID table. */
1339 POLICY_WRLOCK;
1340 memcpy(&policydb, &newpolicydb, sizeof policydb);
1341 sidtab_set(&sidtab, &newsidtab);
1342 seqno = ++latest_granting;
1343 policydb_loaded_version = policydb.policyvers;
1344 POLICY_WRUNLOCK;
1345 LOAD_UNLOCK;
1346
1347 /* Free the old policydb and SID table. */
1348 policydb_destroy(&oldpolicydb);
1349 sidtab_destroy(&oldsidtab);
1350
1351 avc_ss_reset(seqno);
1352 selnl_notify_policyload(seqno);
1353 selinux_netlbl_cache_invalidate();
1354
1355 return 0;
1356
1357 err:
1358 LOAD_UNLOCK;
1359 sidtab_destroy(&newsidtab);
1360 policydb_destroy(&newpolicydb);
1361 return rc;
1362
1363 }
1364
1365 /**
1366 * security_port_sid - Obtain the SID for a port.
1367 * @domain: communication domain aka address family
1368 * @type: socket type
1369 * @protocol: protocol number
1370 * @port: port number
1371 * @out_sid: security identifier
1372 */
1373 int security_port_sid(u16 domain,
1374 u16 type,
1375 u8 protocol,
1376 u16 port,
1377 u32 *out_sid)
1378 {
1379 struct ocontext *c;
1380 int rc = 0;
1381
1382 POLICY_RDLOCK;
1383
1384 c = policydb.ocontexts[OCON_PORT];
1385 while (c) {
1386 if (c->u.port.protocol == protocol &&
1387 c->u.port.low_port <= port &&
1388 c->u.port.high_port >= port)
1389 break;
1390 c = c->next;
1391 }
1392
1393 if (c) {
1394 if (!c->sid[0]) {
1395 rc = sidtab_context_to_sid(&sidtab,
1396 &c->context[0],
1397 &c->sid[0]);
1398 if (rc)
1399 goto out;
1400 }
1401 *out_sid = c->sid[0];
1402 } else {
1403 *out_sid = SECINITSID_PORT;
1404 }
1405
1406 out:
1407 POLICY_RDUNLOCK;
1408 return rc;
1409 }
1410
1411 /**
1412 * security_netif_sid - Obtain the SID for a network interface.
1413 * @name: interface name
1414 * @if_sid: interface SID
1415 * @msg_sid: default SID for received packets
1416 */
1417 int security_netif_sid(char *name,
1418 u32 *if_sid,
1419 u32 *msg_sid)
1420 {
1421 int rc = 0;
1422 struct ocontext *c;
1423
1424 POLICY_RDLOCK;
1425
1426 c = policydb.ocontexts[OCON_NETIF];
1427 while (c) {
1428 if (strcmp(name, c->u.name) == 0)
1429 break;
1430 c = c->next;
1431 }
1432
1433 if (c) {
1434 if (!c->sid[0] || !c->sid[1]) {
1435 rc = sidtab_context_to_sid(&sidtab,
1436 &c->context[0],
1437 &c->sid[0]);
1438 if (rc)
1439 goto out;
1440 rc = sidtab_context_to_sid(&sidtab,
1441 &c->context[1],
1442 &c->sid[1]);
1443 if (rc)
1444 goto out;
1445 }
1446 *if_sid = c->sid[0];
1447 *msg_sid = c->sid[1];
1448 } else {
1449 *if_sid = SECINITSID_NETIF;
1450 *msg_sid = SECINITSID_NETMSG;
1451 }
1452
1453 out:
1454 POLICY_RDUNLOCK;
1455 return rc;
1456 }
1457
1458 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1459 {
1460 int i, fail = 0;
1461
1462 for(i = 0; i < 4; i++)
1463 if(addr[i] != (input[i] & mask[i])) {
1464 fail = 1;
1465 break;
1466 }
1467
1468 return !fail;
1469 }
1470
1471 /**
1472 * security_node_sid - Obtain the SID for a node (host).
1473 * @domain: communication domain aka address family
1474 * @addrp: address
1475 * @addrlen: address length in bytes
1476 * @out_sid: security identifier
1477 */
1478 int security_node_sid(u16 domain,
1479 void *addrp,
1480 u32 addrlen,
1481 u32 *out_sid)
1482 {
1483 int rc = 0;
1484 struct ocontext *c;
1485
1486 POLICY_RDLOCK;
1487
1488 switch (domain) {
1489 case AF_INET: {
1490 u32 addr;
1491
1492 if (addrlen != sizeof(u32)) {
1493 rc = -EINVAL;
1494 goto out;
1495 }
1496
1497 addr = *((u32 *)addrp);
1498
1499 c = policydb.ocontexts[OCON_NODE];
1500 while (c) {
1501 if (c->u.node.addr == (addr & c->u.node.mask))
1502 break;
1503 c = c->next;
1504 }
1505 break;
1506 }
1507
1508 case AF_INET6:
1509 if (addrlen != sizeof(u64) * 2) {
1510 rc = -EINVAL;
1511 goto out;
1512 }
1513 c = policydb.ocontexts[OCON_NODE6];
1514 while (c) {
1515 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1516 c->u.node6.mask))
1517 break;
1518 c = c->next;
1519 }
1520 break;
1521
1522 default:
1523 *out_sid = SECINITSID_NODE;
1524 goto out;
1525 }
1526
1527 if (c) {
1528 if (!c->sid[0]) {
1529 rc = sidtab_context_to_sid(&sidtab,
1530 &c->context[0],
1531 &c->sid[0]);
1532 if (rc)
1533 goto out;
1534 }
1535 *out_sid = c->sid[0];
1536 } else {
1537 *out_sid = SECINITSID_NODE;
1538 }
1539
1540 out:
1541 POLICY_RDUNLOCK;
1542 return rc;
1543 }
1544
1545 #define SIDS_NEL 25
1546
1547 /**
1548 * security_get_user_sids - Obtain reachable SIDs for a user.
1549 * @fromsid: starting SID
1550 * @username: username
1551 * @sids: array of reachable SIDs for user
1552 * @nel: number of elements in @sids
1553 *
1554 * Generate the set of SIDs for legal security contexts
1555 * for a given user that can be reached by @fromsid.
1556 * Set *@sids to point to a dynamically allocated
1557 * array containing the set of SIDs. Set *@nel to the
1558 * number of elements in the array.
1559 */
1560
1561 int security_get_user_sids(u32 fromsid,
1562 char *username,
1563 u32 **sids,
1564 u32 *nel)
1565 {
1566 struct context *fromcon, usercon;
1567 u32 *mysids, *mysids2, sid;
1568 u32 mynel = 0, maxnel = SIDS_NEL;
1569 struct user_datum *user;
1570 struct role_datum *role;
1571 struct av_decision avd;
1572 struct ebitmap_node *rnode, *tnode;
1573 int rc = 0, i, j;
1574
1575 if (!ss_initialized) {
1576 *sids = NULL;
1577 *nel = 0;
1578 goto out;
1579 }
1580
1581 POLICY_RDLOCK;
1582
1583 fromcon = sidtab_search(&sidtab, fromsid);
1584 if (!fromcon) {
1585 rc = -EINVAL;
1586 goto out_unlock;
1587 }
1588
1589 user = hashtab_search(policydb.p_users.table, username);
1590 if (!user) {
1591 rc = -EINVAL;
1592 goto out_unlock;
1593 }
1594 usercon.user = user->value;
1595
1596 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1597 if (!mysids) {
1598 rc = -ENOMEM;
1599 goto out_unlock;
1600 }
1601
1602 ebitmap_for_each_bit(&user->roles, rnode, i) {
1603 if (!ebitmap_node_get_bit(rnode, i))
1604 continue;
1605 role = policydb.role_val_to_struct[i];
1606 usercon.role = i+1;
1607 ebitmap_for_each_bit(&role->types, tnode, j) {
1608 if (!ebitmap_node_get_bit(tnode, j))
1609 continue;
1610 usercon.type = j+1;
1611
1612 if (mls_setup_user_range(fromcon, user, &usercon))
1613 continue;
1614
1615 rc = context_struct_compute_av(fromcon, &usercon,
1616 SECCLASS_PROCESS,
1617 PROCESS__TRANSITION,
1618 &avd);
1619 if (rc || !(avd.allowed & PROCESS__TRANSITION))
1620 continue;
1621 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1622 if (rc) {
1623 kfree(mysids);
1624 goto out_unlock;
1625 }
1626 if (mynel < maxnel) {
1627 mysids[mynel++] = sid;
1628 } else {
1629 maxnel += SIDS_NEL;
1630 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1631 if (!mysids2) {
1632 rc = -ENOMEM;
1633 kfree(mysids);
1634 goto out_unlock;
1635 }
1636 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1637 kfree(mysids);
1638 mysids = mysids2;
1639 mysids[mynel++] = sid;
1640 }
1641 }
1642 }
1643
1644 *sids = mysids;
1645 *nel = mynel;
1646
1647 out_unlock:
1648 POLICY_RDUNLOCK;
1649 out:
1650 return rc;
1651 }
1652
1653 /**
1654 * security_genfs_sid - Obtain a SID for a file in a filesystem
1655 * @fstype: filesystem type
1656 * @path: path from root of mount
1657 * @sclass: file security class
1658 * @sid: SID for path
1659 *
1660 * Obtain a SID to use for a file in a filesystem that
1661 * cannot support xattr or use a fixed labeling behavior like
1662 * transition SIDs or task SIDs.
1663 */
1664 int security_genfs_sid(const char *fstype,
1665 char *path,
1666 u16 sclass,
1667 u32 *sid)
1668 {
1669 int len;
1670 struct genfs *genfs;
1671 struct ocontext *c;
1672 int rc = 0, cmp = 0;
1673
1674 POLICY_RDLOCK;
1675
1676 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1677 cmp = strcmp(fstype, genfs->fstype);
1678 if (cmp <= 0)
1679 break;
1680 }
1681
1682 if (!genfs || cmp) {
1683 *sid = SECINITSID_UNLABELED;
1684 rc = -ENOENT;
1685 goto out;
1686 }
1687
1688 for (c = genfs->head; c; c = c->next) {
1689 len = strlen(c->u.name);
1690 if ((!c->v.sclass || sclass == c->v.sclass) &&
1691 (strncmp(c->u.name, path, len) == 0))
1692 break;
1693 }
1694
1695 if (!c) {
1696 *sid = SECINITSID_UNLABELED;
1697 rc = -ENOENT;
1698 goto out;
1699 }
1700
1701 if (!c->sid[0]) {
1702 rc = sidtab_context_to_sid(&sidtab,
1703 &c->context[0],
1704 &c->sid[0]);
1705 if (rc)
1706 goto out;
1707 }
1708
1709 *sid = c->sid[0];
1710 out:
1711 POLICY_RDUNLOCK;
1712 return rc;
1713 }
1714
1715 /**
1716 * security_fs_use - Determine how to handle labeling for a filesystem.
1717 * @fstype: filesystem type
1718 * @behavior: labeling behavior
1719 * @sid: SID for filesystem (superblock)
1720 */
1721 int security_fs_use(
1722 const char *fstype,
1723 unsigned int *behavior,
1724 u32 *sid)
1725 {
1726 int rc = 0;
1727 struct ocontext *c;
1728
1729 POLICY_RDLOCK;
1730
1731 c = policydb.ocontexts[OCON_FSUSE];
1732 while (c) {
1733 if (strcmp(fstype, c->u.name) == 0)
1734 break;
1735 c = c->next;
1736 }
1737
1738 if (c) {
1739 *behavior = c->v.behavior;
1740 if (!c->sid[0]) {
1741 rc = sidtab_context_to_sid(&sidtab,
1742 &c->context[0],
1743 &c->sid[0]);
1744 if (rc)
1745 goto out;
1746 }
1747 *sid = c->sid[0];
1748 } else {
1749 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1750 if (rc) {
1751 *behavior = SECURITY_FS_USE_NONE;
1752 rc = 0;
1753 } else {
1754 *behavior = SECURITY_FS_USE_GENFS;
1755 }
1756 }
1757
1758 out:
1759 POLICY_RDUNLOCK;
1760 return rc;
1761 }
1762
1763 int security_get_bools(int *len, char ***names, int **values)
1764 {
1765 int i, rc = -ENOMEM;
1766
1767 POLICY_RDLOCK;
1768 *names = NULL;
1769 *values = NULL;
1770
1771 *len = policydb.p_bools.nprim;
1772 if (!*len) {
1773 rc = 0;
1774 goto out;
1775 }
1776
1777 *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1778 if (!*names)
1779 goto err;
1780
1781 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1782 if (!*values)
1783 goto err;
1784
1785 for (i = 0; i < *len; i++) {
1786 size_t name_len;
1787 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1788 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1789 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1790 if (!(*names)[i])
1791 goto err;
1792 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1793 (*names)[i][name_len - 1] = 0;
1794 }
1795 rc = 0;
1796 out:
1797 POLICY_RDUNLOCK;
1798 return rc;
1799 err:
1800 if (*names) {
1801 for (i = 0; i < *len; i++)
1802 kfree((*names)[i]);
1803 }
1804 kfree(*values);
1805 goto out;
1806 }
1807
1808
1809 int security_set_bools(int len, int *values)
1810 {
1811 int i, rc = 0;
1812 int lenp, seqno = 0;
1813 struct cond_node *cur;
1814
1815 POLICY_WRLOCK;
1816
1817 lenp = policydb.p_bools.nprim;
1818 if (len != lenp) {
1819 rc = -EFAULT;
1820 goto out;
1821 }
1822
1823 for (i = 0; i < len; i++) {
1824 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1825 audit_log(current->audit_context, GFP_ATOMIC,
1826 AUDIT_MAC_CONFIG_CHANGE,
1827 "bool=%s val=%d old_val=%d auid=%u",
1828 policydb.p_bool_val_to_name[i],
1829 !!values[i],
1830 policydb.bool_val_to_struct[i]->state,
1831 audit_get_loginuid(current->audit_context));
1832 }
1833 if (values[i]) {
1834 policydb.bool_val_to_struct[i]->state = 1;
1835 } else {
1836 policydb.bool_val_to_struct[i]->state = 0;
1837 }
1838 }
1839
1840 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1841 rc = evaluate_cond_node(&policydb, cur);
1842 if (rc)
1843 goto out;
1844 }
1845
1846 seqno = ++latest_granting;
1847
1848 out:
1849 POLICY_WRUNLOCK;
1850 if (!rc) {
1851 avc_ss_reset(seqno);
1852 selnl_notify_policyload(seqno);
1853 }
1854 return rc;
1855 }
1856
1857 int security_get_bool_value(int bool)
1858 {
1859 int rc = 0;
1860 int len;
1861
1862 POLICY_RDLOCK;
1863
1864 len = policydb.p_bools.nprim;
1865 if (bool >= len) {
1866 rc = -EFAULT;
1867 goto out;
1868 }
1869
1870 rc = policydb.bool_val_to_struct[bool]->state;
1871 out:
1872 POLICY_RDUNLOCK;
1873 return rc;
1874 }
1875
1876 /*
1877 * security_sid_mls_copy() - computes a new sid based on the given
1878 * sid and the mls portion of mls_sid.
1879 */
1880 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1881 {
1882 struct context *context1;
1883 struct context *context2;
1884 struct context newcon;
1885 char *s;
1886 u32 len;
1887 int rc = 0;
1888
1889 if (!ss_initialized || !selinux_mls_enabled) {
1890 *new_sid = sid;
1891 goto out;
1892 }
1893
1894 context_init(&newcon);
1895
1896 POLICY_RDLOCK;
1897 context1 = sidtab_search(&sidtab, sid);
1898 if (!context1) {
1899 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1900 "%d\n", sid);
1901 rc = -EINVAL;
1902 goto out_unlock;
1903 }
1904
1905 context2 = sidtab_search(&sidtab, mls_sid);
1906 if (!context2) {
1907 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1908 "%d\n", mls_sid);
1909 rc = -EINVAL;
1910 goto out_unlock;
1911 }
1912
1913 newcon.user = context1->user;
1914 newcon.role = context1->role;
1915 newcon.type = context1->type;
1916 rc = mls_copy_context(&newcon, context2);
1917 if (rc)
1918 goto out_unlock;
1919
1920
1921 /* Check the validity of the new context. */
1922 if (!policydb_context_isvalid(&policydb, &newcon)) {
1923 rc = convert_context_handle_invalid_context(&newcon);
1924 if (rc)
1925 goto bad;
1926 }
1927
1928 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
1929 goto out_unlock;
1930
1931 bad:
1932 if (!context_struct_to_string(&newcon, &s, &len)) {
1933 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1934 "security_sid_mls_copy: invalid context %s", s);
1935 kfree(s);
1936 }
1937
1938 out_unlock:
1939 POLICY_RDUNLOCK;
1940 context_destroy(&newcon);
1941 out:
1942 return rc;
1943 }
1944
1945 struct selinux_audit_rule {
1946 u32 au_seqno;
1947 struct context au_ctxt;
1948 };
1949
1950 void selinux_audit_rule_free(struct selinux_audit_rule *rule)
1951 {
1952 if (rule) {
1953 context_destroy(&rule->au_ctxt);
1954 kfree(rule);
1955 }
1956 }
1957
1958 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
1959 struct selinux_audit_rule **rule)
1960 {
1961 struct selinux_audit_rule *tmprule;
1962 struct role_datum *roledatum;
1963 struct type_datum *typedatum;
1964 struct user_datum *userdatum;
1965 int rc = 0;
1966
1967 *rule = NULL;
1968
1969 if (!ss_initialized)
1970 return -ENOTSUPP;
1971
1972 switch (field) {
1973 case AUDIT_SUBJ_USER:
1974 case AUDIT_SUBJ_ROLE:
1975 case AUDIT_SUBJ_TYPE:
1976 case AUDIT_OBJ_USER:
1977 case AUDIT_OBJ_ROLE:
1978 case AUDIT_OBJ_TYPE:
1979 /* only 'equals' and 'not equals' fit user, role, and type */
1980 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
1981 return -EINVAL;
1982 break;
1983 case AUDIT_SUBJ_SEN:
1984 case AUDIT_SUBJ_CLR:
1985 case AUDIT_OBJ_LEV_LOW:
1986 case AUDIT_OBJ_LEV_HIGH:
1987 /* we do not allow a range, indicated by the presense of '-' */
1988 if (strchr(rulestr, '-'))
1989 return -EINVAL;
1990 break;
1991 default:
1992 /* only the above fields are valid */
1993 return -EINVAL;
1994 }
1995
1996 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
1997 if (!tmprule)
1998 return -ENOMEM;
1999
2000 context_init(&tmprule->au_ctxt);
2001
2002 POLICY_RDLOCK;
2003
2004 tmprule->au_seqno = latest_granting;
2005
2006 switch (field) {
2007 case AUDIT_SUBJ_USER:
2008 case AUDIT_OBJ_USER:
2009 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2010 if (!userdatum)
2011 rc = -EINVAL;
2012 else
2013 tmprule->au_ctxt.user = userdatum->value;
2014 break;
2015 case AUDIT_SUBJ_ROLE:
2016 case AUDIT_OBJ_ROLE:
2017 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2018 if (!roledatum)
2019 rc = -EINVAL;
2020 else
2021 tmprule->au_ctxt.role = roledatum->value;
2022 break;
2023 case AUDIT_SUBJ_TYPE:
2024 case AUDIT_OBJ_TYPE:
2025 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2026 if (!typedatum)
2027 rc = -EINVAL;
2028 else
2029 tmprule->au_ctxt.type = typedatum->value;
2030 break;
2031 case AUDIT_SUBJ_SEN:
2032 case AUDIT_SUBJ_CLR:
2033 case AUDIT_OBJ_LEV_LOW:
2034 case AUDIT_OBJ_LEV_HIGH:
2035 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2036 break;
2037 }
2038
2039 POLICY_RDUNLOCK;
2040
2041 if (rc) {
2042 selinux_audit_rule_free(tmprule);
2043 tmprule = NULL;
2044 }
2045
2046 *rule = tmprule;
2047
2048 return rc;
2049 }
2050
2051 int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2052 struct selinux_audit_rule *rule,
2053 struct audit_context *actx)
2054 {
2055 struct context *ctxt;
2056 struct mls_level *level;
2057 int match = 0;
2058
2059 if (!rule) {
2060 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2061 "selinux_audit_rule_match: missing rule\n");
2062 return -ENOENT;
2063 }
2064
2065 POLICY_RDLOCK;
2066
2067 if (rule->au_seqno < latest_granting) {
2068 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2069 "selinux_audit_rule_match: stale rule\n");
2070 match = -ESTALE;
2071 goto out;
2072 }
2073
2074 ctxt = sidtab_search(&sidtab, sid);
2075 if (!ctxt) {
2076 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2077 "selinux_audit_rule_match: unrecognized SID %d\n",
2078 sid);
2079 match = -ENOENT;
2080 goto out;
2081 }
2082
2083 /* a field/op pair that is not caught here will simply fall through
2084 without a match */
2085 switch (field) {
2086 case AUDIT_SUBJ_USER:
2087 case AUDIT_OBJ_USER:
2088 switch (op) {
2089 case AUDIT_EQUAL:
2090 match = (ctxt->user == rule->au_ctxt.user);
2091 break;
2092 case AUDIT_NOT_EQUAL:
2093 match = (ctxt->user != rule->au_ctxt.user);
2094 break;
2095 }
2096 break;
2097 case AUDIT_SUBJ_ROLE:
2098 case AUDIT_OBJ_ROLE:
2099 switch (op) {
2100 case AUDIT_EQUAL:
2101 match = (ctxt->role == rule->au_ctxt.role);
2102 break;
2103 case AUDIT_NOT_EQUAL:
2104 match = (ctxt->role != rule->au_ctxt.role);
2105 break;
2106 }
2107 break;
2108 case AUDIT_SUBJ_TYPE:
2109 case AUDIT_OBJ_TYPE:
2110 switch (op) {
2111 case AUDIT_EQUAL:
2112 match = (ctxt->type == rule->au_ctxt.type);
2113 break;
2114 case AUDIT_NOT_EQUAL:
2115 match = (ctxt->type != rule->au_ctxt.type);
2116 break;
2117 }
2118 break;
2119 case AUDIT_SUBJ_SEN:
2120 case AUDIT_SUBJ_CLR:
2121 case AUDIT_OBJ_LEV_LOW:
2122 case AUDIT_OBJ_LEV_HIGH:
2123 level = ((field == AUDIT_SUBJ_SEN ||
2124 field == AUDIT_OBJ_LEV_LOW) ?
2125 &ctxt->range.level[0] : &ctxt->range.level[1]);
2126 switch (op) {
2127 case AUDIT_EQUAL:
2128 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2129 level);
2130 break;
2131 case AUDIT_NOT_EQUAL:
2132 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2133 level);
2134 break;
2135 case AUDIT_LESS_THAN:
2136 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2137 level) &&
2138 !mls_level_eq(&rule->au_ctxt.range.level[0],
2139 level));
2140 break;
2141 case AUDIT_LESS_THAN_OR_EQUAL:
2142 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2143 level);
2144 break;
2145 case AUDIT_GREATER_THAN:
2146 match = (mls_level_dom(level,
2147 &rule->au_ctxt.range.level[0]) &&
2148 !mls_level_eq(level,
2149 &rule->au_ctxt.range.level[0]));
2150 break;
2151 case AUDIT_GREATER_THAN_OR_EQUAL:
2152 match = mls_level_dom(level,
2153 &rule->au_ctxt.range.level[0]);
2154 break;
2155 }
2156 }
2157
2158 out:
2159 POLICY_RDUNLOCK;
2160 return match;
2161 }
2162
2163 static int (*aurule_callback)(void) = NULL;
2164
2165 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2166 u16 class, u32 perms, u32 *retained)
2167 {
2168 int err = 0;
2169
2170 if (event == AVC_CALLBACK_RESET && aurule_callback)
2171 err = aurule_callback();
2172 return err;
2173 }
2174
2175 static int __init aurule_init(void)
2176 {
2177 int err;
2178
2179 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2180 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2181 if (err)
2182 panic("avc_add_callback() failed, error %d\n", err);
2183
2184 return err;
2185 }
2186 __initcall(aurule_init);
2187
2188 void selinux_audit_set_callback(int (*callback)(void))
2189 {
2190 aurule_callback = callback;
2191 }
2192
2193 #ifdef CONFIG_NETLABEL
2194 /*
2195 * This is the structure we store inside the NetLabel cache block.
2196 */
2197 #define NETLBL_CACHE(x) ((struct netlbl_cache *)(x))
2198 #define NETLBL_CACHE_T_NONE 0
2199 #define NETLBL_CACHE_T_SID 1
2200 #define NETLBL_CACHE_T_MLS 2
2201 struct netlbl_cache {
2202 u32 type;
2203 union {
2204 u32 sid;
2205 struct mls_range mls_label;
2206 } data;
2207 };
2208
2209 /**
2210 * selinux_netlbl_cache_free - Free the NetLabel cached data
2211 * @data: the data to free
2212 *
2213 * Description:
2214 * This function is intended to be used as the free() callback inside the
2215 * netlbl_lsm_cache structure.
2216 *
2217 */
2218 static void selinux_netlbl_cache_free(const void *data)
2219 {
2220 struct netlbl_cache *cache;
2221
2222 if (data == NULL)
2223 return;
2224
2225 cache = NETLBL_CACHE(data);
2226 switch (cache->type) {
2227 case NETLBL_CACHE_T_MLS:
2228 ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2229 break;
2230 }
2231 kfree(data);
2232 }
2233
2234 /**
2235 * selinux_netlbl_cache_add - Add an entry to the NetLabel cache
2236 * @skb: the packet
2237 * @ctx: the SELinux context
2238 *
2239 * Description:
2240 * Attempt to cache the context in @ctx, which was derived from the packet in
2241 * @skb, in the NetLabel subsystem cache.
2242 *
2243 */
2244 static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx)
2245 {
2246 struct netlbl_cache *cache = NULL;
2247 struct netlbl_lsm_secattr secattr;
2248
2249 netlbl_secattr_init(&secattr);
2250 secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2251 if (secattr.cache == NULL)
2252 goto netlbl_cache_add_return;
2253
2254 cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2255 if (cache == NULL)
2256 goto netlbl_cache_add_return;
2257
2258 cache->type = NETLBL_CACHE_T_MLS;
2259 if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2260 &ctx->range.level[0].cat) != 0)
2261 goto netlbl_cache_add_return;
2262 cache->data.mls_label.level[1].cat.highbit =
2263 cache->data.mls_label.level[0].cat.highbit;
2264 cache->data.mls_label.level[1].cat.node =
2265 cache->data.mls_label.level[0].cat.node;
2266 cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2267 cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2268
2269 secattr.cache->free = selinux_netlbl_cache_free;
2270 secattr.cache->data = (void *)cache;
2271 secattr.flags = NETLBL_SECATTR_CACHE;
2272
2273 netlbl_cache_add(skb, &secattr);
2274
2275 netlbl_cache_add_return:
2276 netlbl_secattr_destroy(&secattr);
2277 }
2278
2279 /**
2280 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
2281 *
2282 * Description:
2283 * Invalidate the NetLabel security attribute mapping cache.
2284 *
2285 */
2286 void selinux_netlbl_cache_invalidate(void)
2287 {
2288 netlbl_cache_invalidate();
2289 }
2290
2291 /**
2292 * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2293 * @skb: the network packet
2294 * @secattr: the NetLabel packet security attributes
2295 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2296 * @sid: the SELinux SID
2297 *
2298 * Description:
2299 * Convert the given NetLabel packet security attributes in @secattr into a
2300 * SELinux SID. If the @secattr field does not contain a full SELinux
2301 * SID/context then use the context in @base_sid as the foundation. If @skb
2302 * is not NULL attempt to cache as much data as possibile. Returns zero on
2303 * success, negative values on failure.
2304 *
2305 */
2306 static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
2307 struct netlbl_lsm_secattr *secattr,
2308 u32 base_sid,
2309 u32 *sid)
2310 {
2311 int rc = -EIDRM;
2312 struct context *ctx;
2313 struct context ctx_new;
2314 struct netlbl_cache *cache;
2315
2316 POLICY_RDLOCK;
2317
2318 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2319 cache = NETLBL_CACHE(secattr->cache->data);
2320 switch (cache->type) {
2321 case NETLBL_CACHE_T_SID:
2322 *sid = cache->data.sid;
2323 rc = 0;
2324 break;
2325 case NETLBL_CACHE_T_MLS:
2326 ctx = sidtab_search(&sidtab, base_sid);
2327 if (ctx == NULL)
2328 goto netlbl_secattr_to_sid_return;
2329
2330 ctx_new.user = ctx->user;
2331 ctx_new.role = ctx->role;
2332 ctx_new.type = ctx->type;
2333 ctx_new.range.level[0].sens =
2334 cache->data.mls_label.level[0].sens;
2335 ctx_new.range.level[0].cat.highbit =
2336 cache->data.mls_label.level[0].cat.highbit;
2337 ctx_new.range.level[0].cat.node =
2338 cache->data.mls_label.level[0].cat.node;
2339 ctx_new.range.level[1].sens =
2340 cache->data.mls_label.level[1].sens;
2341 ctx_new.range.level[1].cat.highbit =
2342 cache->data.mls_label.level[1].cat.highbit;
2343 ctx_new.range.level[1].cat.node =
2344 cache->data.mls_label.level[1].cat.node;
2345
2346 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2347 break;
2348 default:
2349 goto netlbl_secattr_to_sid_return;
2350 }
2351 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2352 ctx = sidtab_search(&sidtab, base_sid);
2353 if (ctx == NULL)
2354 goto netlbl_secattr_to_sid_return;
2355
2356 ctx_new.user = ctx->user;
2357 ctx_new.role = ctx->role;
2358 ctx_new.type = ctx->type;
2359 mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl);
2360 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2361 if (mls_import_cat(&ctx_new,
2362 secattr->mls_cat,
2363 secattr->mls_cat_len,
2364 NULL,
2365 0) != 0)
2366 goto netlbl_secattr_to_sid_return;
2367 ctx_new.range.level[1].cat.highbit =
2368 ctx_new.range.level[0].cat.highbit;
2369 ctx_new.range.level[1].cat.node =
2370 ctx_new.range.level[0].cat.node;
2371 } else {
2372 ebitmap_init(&ctx_new.range.level[0].cat);
2373 ebitmap_init(&ctx_new.range.level[1].cat);
2374 }
2375 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2376 goto netlbl_secattr_to_sid_return_cleanup;
2377
2378 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2379 if (rc != 0)
2380 goto netlbl_secattr_to_sid_return_cleanup;
2381
2382 if (skb != NULL)
2383 selinux_netlbl_cache_add(skb, &ctx_new);
2384 ebitmap_destroy(&ctx_new.range.level[0].cat);
2385 } else {
2386 *sid = SECSID_NULL;
2387 rc = 0;
2388 }
2389
2390 netlbl_secattr_to_sid_return:
2391 POLICY_RDUNLOCK;
2392 return rc;
2393 netlbl_secattr_to_sid_return_cleanup:
2394 ebitmap_destroy(&ctx_new.range.level[0].cat);
2395 goto netlbl_secattr_to_sid_return;
2396 }
2397
2398 /**
2399 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
2400 * @skb: the packet
2401 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2402 * @sid: the SID
2403 *
2404 * Description:
2405 * Call the NetLabel mechanism to get the security attributes of the given
2406 * packet and use those attributes to determine the correct context/SID to
2407 * assign to the packet. Returns zero on success, negative values on failure.
2408 *
2409 */
2410 static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
2411 u32 base_sid,
2412 u32 *sid)
2413 {
2414 int rc;
2415 struct netlbl_lsm_secattr secattr;
2416
2417 netlbl_secattr_init(&secattr);
2418 rc = netlbl_skbuff_getattr(skb, &secattr);
2419 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2420 rc = selinux_netlbl_secattr_to_sid(skb,
2421 &secattr,
2422 base_sid,
2423 sid);
2424 else
2425 *sid = SECSID_NULL;
2426 netlbl_secattr_destroy(&secattr);
2427
2428 return rc;
2429 }
2430
2431 /**
2432 * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism
2433 * @sock: the socket to label
2434 * @sid: the SID to use
2435 *
2436 * Description:
2437 * Attempt to label a socket using the NetLabel mechanism using the given
2438 * SID. Returns zero values on success, negative values on failure.
2439 *
2440 */
2441 static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
2442 {
2443 int rc = -ENOENT;
2444 struct sk_security_struct *sksec = sock->sk->sk_security;
2445 struct netlbl_lsm_secattr secattr;
2446 struct context *ctx;
2447
2448 if (!ss_initialized)
2449 return 0;
2450
2451 netlbl_secattr_init(&secattr);
2452
2453 POLICY_RDLOCK;
2454
2455 ctx = sidtab_search(&sidtab, sid);
2456 if (ctx == NULL)
2457 goto netlbl_socket_setsid_return;
2458
2459 secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2460 GFP_ATOMIC);
2461 mls_export_lvl(ctx, &secattr.mls_lvl, NULL);
2462 rc = mls_export_cat(ctx,
2463 &secattr.mls_cat,
2464 &secattr.mls_cat_len,
2465 NULL,
2466 NULL);
2467 if (rc != 0)
2468 goto netlbl_socket_setsid_return;
2469
2470 secattr.flags |= NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
2471 if (secattr.mls_cat)
2472 secattr.flags |= NETLBL_SECATTR_MLS_CAT;
2473
2474 rc = netlbl_socket_setattr(sock, &secattr);
2475 if (rc == 0)
2476 sksec->nlbl_state = NLBL_LABELED;
2477
2478 netlbl_socket_setsid_return:
2479 POLICY_RDUNLOCK;
2480 netlbl_secattr_destroy(&secattr);
2481 return rc;
2482 }
2483
2484 /**
2485 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
2486 * @ssec: the sk_security_struct
2487 * @family: the socket family
2488 *
2489 * Description:
2490 * Called when a new sk_security_struct is allocated to initialize the NetLabel
2491 * fields.
2492 *
2493 */
2494 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
2495 int family)
2496 {
2497 if (family == PF_INET)
2498 ssec->nlbl_state = NLBL_REQUIRE;
2499 else
2500 ssec->nlbl_state = NLBL_UNSET;
2501 }
2502
2503 /**
2504 * selinux_netlbl_sk_clone_security - Copy the NetLabel fields
2505 * @ssec: the original sk_security_struct
2506 * @newssec: the cloned sk_security_struct
2507 *
2508 * Description:
2509 * Clone the NetLabel specific sk_security_struct fields from @ssec to
2510 * @newssec.
2511 *
2512 */
2513 void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec,
2514 struct sk_security_struct *newssec)
2515 {
2516 newssec->sclass = ssec->sclass;
2517 if (ssec->nlbl_state != NLBL_UNSET)
2518 newssec->nlbl_state = NLBL_REQUIRE;
2519 else
2520 newssec->nlbl_state = NLBL_UNSET;
2521 }
2522
2523 /**
2524 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
2525 * @sock: the socket to label
2526 * @sock_family: the socket family
2527 * @sid: the SID to use
2528 *
2529 * Description:
2530 * Attempt to label a socket using the NetLabel mechanism using the given
2531 * SID. Returns zero values on success, negative values on failure.
2532 *
2533 */
2534 int selinux_netlbl_socket_post_create(struct socket *sock,
2535 int sock_family,
2536 u32 sid)
2537 {
2538 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2539 struct sk_security_struct *sksec = sock->sk->sk_security;
2540
2541 sksec->sclass = isec->sclass;
2542
2543 if (sock_family != PF_INET)
2544 return 0;
2545
2546 sksec->nlbl_state = NLBL_REQUIRE;
2547 return selinux_netlbl_socket_setsid(sock, sid);
2548 }
2549
2550 /**
2551 * selinux_netlbl_sock_graft - Netlabel the new socket
2552 * @sk: the new connection
2553 * @sock: the new socket
2554 *
2555 * Description:
2556 * The connection represented by @sk is being grafted onto @sock so set the
2557 * socket's NetLabel to match the SID of @sk.
2558 *
2559 */
2560 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
2561 {
2562 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2563 struct sk_security_struct *sksec = sk->sk_security;
2564 struct netlbl_lsm_secattr secattr;
2565 u32 nlbl_peer_sid;
2566
2567 sksec->sclass = isec->sclass;
2568
2569 if (sk->sk_family != PF_INET)
2570 return;
2571
2572 netlbl_secattr_init(&secattr);
2573 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
2574 secattr.flags != NETLBL_SECATTR_NONE &&
2575 selinux_netlbl_secattr_to_sid(NULL,
2576 &secattr,
2577 SECINITSID_UNLABELED,
2578 &nlbl_peer_sid) == 0)
2579 sksec->peer_sid = nlbl_peer_sid;
2580 netlbl_secattr_destroy(&secattr);
2581
2582 sksec->nlbl_state = NLBL_REQUIRE;
2583
2584 /* Try to set the NetLabel on the socket to save time later, if we fail
2585 * here we will pick up the pieces in later calls to
2586 * selinux_netlbl_inode_permission(). */
2587 selinux_netlbl_socket_setsid(sock, sksec->sid);
2588 }
2589
2590 /**
2591 * selinux_netlbl_inet_conn_request - Handle a new connection request
2592 * @skb: the packet
2593 * @sock_sid: the SID of the parent socket
2594 *
2595 * Description:
2596 * If present, use the security attributes of the packet in @skb and the
2597 * parent sock's SID to arrive at a SID for the new child sock. Returns the
2598 * SID of the connection or SECSID_NULL on failure.
2599 *
2600 */
2601 u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid)
2602 {
2603 int rc;
2604 u32 peer_sid;
2605
2606 rc = selinux_netlbl_skbuff_getsid(skb, sock_sid, &peer_sid);
2607 if (rc != 0)
2608 return SECSID_NULL;
2609
2610 return peer_sid;
2611 }
2612
2613 /**
2614 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
2615 * @inode: the file descriptor's inode
2616 * @mask: the permission mask
2617 *
2618 * Description:
2619 * Looks at a file's inode and if it is marked as a socket protected by
2620 * NetLabel then verify that the socket has been labeled, if not try to label
2621 * the socket now with the inode's SID. Returns zero on success, negative
2622 * values on failure.
2623 *
2624 */
2625 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
2626 {
2627 int rc;
2628 struct inode_security_struct *isec;
2629 struct sk_security_struct *sksec;
2630 struct socket *sock;
2631
2632 if (!S_ISSOCK(inode->i_mode))
2633 return 0;
2634
2635 sock = SOCKET_I(inode);
2636 isec = inode->i_security;
2637 sksec = sock->sk->sk_security;
2638 mutex_lock(&isec->lock);
2639 if (unlikely(sksec->nlbl_state == NLBL_REQUIRE &&
2640 (mask & (MAY_WRITE | MAY_APPEND)))) {
2641 lock_sock(sock->sk);
2642 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2643 release_sock(sock->sk);
2644 } else
2645 rc = 0;
2646 mutex_unlock(&isec->lock);
2647
2648 return rc;
2649 }
2650
2651 /**
2652 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
2653 * @sksec: the sock's sk_security_struct
2654 * @skb: the packet
2655 * @ad: the audit data
2656 *
2657 * Description:
2658 * Fetch the NetLabel security attributes from @skb and perform an access check
2659 * against the receiving socket. Returns zero on success, negative values on
2660 * error.
2661 *
2662 */
2663 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
2664 struct sk_buff *skb,
2665 struct avc_audit_data *ad)
2666 {
2667 int rc;
2668 u32 netlbl_sid;
2669 u32 recv_perm;
2670
2671 rc = selinux_netlbl_skbuff_getsid(skb,
2672 SECINITSID_UNLABELED,
2673 &netlbl_sid);
2674 if (rc != 0)
2675 return rc;
2676
2677 if (netlbl_sid == SECSID_NULL)
2678 return 0;
2679
2680 switch (sksec->sclass) {
2681 case SECCLASS_UDP_SOCKET:
2682 recv_perm = UDP_SOCKET__RECVFROM;
2683 break;
2684 case SECCLASS_TCP_SOCKET:
2685 recv_perm = TCP_SOCKET__RECVFROM;
2686 break;
2687 default:
2688 recv_perm = RAWIP_SOCKET__RECVFROM;
2689 }
2690
2691 rc = avc_has_perm(sksec->sid,
2692 netlbl_sid,
2693 sksec->sclass,
2694 recv_perm,
2695 ad);
2696 if (rc == 0)
2697 return 0;
2698
2699 netlbl_skbuff_err(skb, rc);
2700 return rc;
2701 }
2702
2703 /**
2704 * selinux_netlbl_socket_getpeersec_stream - Return the connected peer's SID
2705 * @sock: the socket
2706 *
2707 * Description:
2708 * Examine @sock to find the connected peer's SID. Returns the SID on success
2709 * or SECSID_NULL on error.
2710 *
2711 */
2712 u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
2713 {
2714 struct sk_security_struct *sksec = sock->sk->sk_security;
2715 return sksec->peer_sid;
2716 }
2717
2718 /**
2719 * selinux_netlbl_socket_getpeersec_dgram - Return the SID of a NetLabel packet
2720 * @skb: the packet
2721 *
2722 * Description:
2723 * Examine @skb to find the SID assigned to it by NetLabel. Returns the SID on
2724 * success, SECSID_NULL on error.
2725 *
2726 */
2727 u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
2728 {
2729 int peer_sid;
2730
2731 if (selinux_netlbl_skbuff_getsid(skb,
2732 SECINITSID_UNLABELED,
2733 &peer_sid) != 0)
2734 return SECSID_NULL;
2735
2736 return peer_sid;
2737 }
2738
2739 /**
2740 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
2741 * @sock: the socket
2742 * @level: the socket level or protocol
2743 * @optname: the socket option name
2744 *
2745 * Description:
2746 * Check the setsockopt() call and if the user is trying to replace the IP
2747 * options on a socket and a NetLabel is in place for the socket deny the
2748 * access; otherwise allow the access. Returns zero when the access is
2749 * allowed, -EACCES when denied, and other negative values on error.
2750 *
2751 */
2752 int selinux_netlbl_socket_setsockopt(struct socket *sock,
2753 int level,
2754 int optname)
2755 {
2756 int rc = 0;
2757 struct inode *inode = SOCK_INODE(sock);
2758 struct sk_security_struct *sksec = sock->sk->sk_security;
2759 struct inode_security_struct *isec = inode->i_security;
2760 struct netlbl_lsm_secattr secattr;
2761
2762 mutex_lock(&isec->lock);
2763 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
2764 sksec->nlbl_state == NLBL_LABELED) {
2765 netlbl_secattr_init(&secattr);
2766 rc = netlbl_socket_getattr(sock, &secattr);
2767 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2768 rc = -EACCES;
2769 netlbl_secattr_destroy(&secattr);
2770 }
2771 mutex_unlock(&isec->lock);
2772
2773 return rc;
2774 }
2775 #endif /* CONFIG_NETLABEL */
Linux kernel - Deliverables
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