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e1000: update version to 7.3.20-k2
[linux-2.6/kvm.git] / security / selinux / ss / services.c
blobca9154dc5d825bea7f680de2f42b0979e4a930a6
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/rcupdate.h>
37 #include <linux/errno.h>
38 #include <linux/in.h>
39 #include <linux/sched.h>
40 #include <linux/audit.h>
41 #include <linux/mutex.h>
42 #include <net/sock.h>
43 #include <net/netlabel.h>
44
45 #include "flask.h"
46 #include "avc.h"
47 #include "avc_ss.h"
48 #include "security.h"
49 #include "context.h"
50 #include "policydb.h"
51 #include "sidtab.h"
52 #include "services.h"
53 #include "conditional.h"
54 #include "mls.h"
55 #include "objsec.h"
56 #include "selinux_netlabel.h"
57 #include "xfrm.h"
58 #include "ebitmap.h"
59
60 extern void selnl_notify_policyload(u32 seqno);
61 unsigned int policydb_loaded_version;
62
63 /*
64 * This is declared in avc.c
65 */
66 extern const struct selinux_class_perm selinux_class_perm;
67
68 static DEFINE_RWLOCK(policy_rwlock);
69 #define POLICY_RDLOCK read_lock(&policy_rwlock)
70 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
71 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
72 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
73
74 static DEFINE_MUTEX(load_mutex);
75 #define LOAD_LOCK mutex_lock(&load_mutex)
76 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
77
78 static struct sidtab sidtab;
79 struct policydb policydb;
80 int ss_initialized = 0;
81
82 /*
83 * The largest sequence number that has been used when
84 * providing an access decision to the access vector cache.
85 * The sequence number only changes when a policy change
86 * occurs.
87 */
88 static u32 latest_granting = 0;
89
90 /* Forward declaration. */
91 static int context_struct_to_string(struct context *context, char **scontext,
92 u32 *scontext_len);
93
94 /*
95 * Return the boolean value of a constraint expression
96 * when it is applied to the specified source and target
97 * security contexts.
98 *
99 * xcontext is a special beast... It is used by the validatetrans rules
100 * only. For these rules, scontext is the context before the transition,
101 * tcontext is the context after the transition, and xcontext is the context
102 * of the process performing the transition. All other callers of
103 * constraint_expr_eval should pass in NULL for xcontext.
104 */
105 static int constraint_expr_eval(struct context *scontext,
106 struct context *tcontext,
107 struct context *xcontext,
108 struct constraint_expr *cexpr)
109 {
110 u32 val1, val2;
111 struct context *c;
112 struct role_datum *r1, *r2;
113 struct mls_level *l1, *l2;
114 struct constraint_expr *e;
115 int s[CEXPR_MAXDEPTH];
116 int sp = -1;
117
118 for (e = cexpr; e; e = e->next) {
119 switch (e->expr_type) {
120 case CEXPR_NOT:
121 BUG_ON(sp < 0);
122 s[sp] = !s[sp];
123 break;
124 case CEXPR_AND:
125 BUG_ON(sp < 1);
126 sp--;
127 s[sp] &= s[sp+1];
128 break;
129 case CEXPR_OR:
130 BUG_ON(sp < 1);
131 sp--;
132 s[sp] |= s[sp+1];
133 break;
134 case CEXPR_ATTR:
135 if (sp == (CEXPR_MAXDEPTH-1))
136 return 0;
137 switch (e->attr) {
138 case CEXPR_USER:
139 val1 = scontext->user;
140 val2 = tcontext->user;
141 break;
142 case CEXPR_TYPE:
143 val1 = scontext->type;
144 val2 = tcontext->type;
145 break;
146 case CEXPR_ROLE:
147 val1 = scontext->role;
148 val2 = tcontext->role;
149 r1 = policydb.role_val_to_struct[val1 - 1];
150 r2 = policydb.role_val_to_struct[val2 - 1];
151 switch (e->op) {
152 case CEXPR_DOM:
153 s[++sp] = ebitmap_get_bit(&r1->dominates,
154 val2 - 1);
155 continue;
156 case CEXPR_DOMBY:
157 s[++sp] = ebitmap_get_bit(&r2->dominates,
158 val1 - 1);
159 continue;
160 case CEXPR_INCOMP:
161 s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
162 val2 - 1) &&
163 !ebitmap_get_bit(&r2->dominates,
164 val1 - 1) );
165 continue;
166 default:
167 break;
168 }
169 break;
170 case CEXPR_L1L2:
171 l1 = &(scontext->range.level[0]);
172 l2 = &(tcontext->range.level[0]);
173 goto mls_ops;
174 case CEXPR_L1H2:
175 l1 = &(scontext->range.level[0]);
176 l2 = &(tcontext->range.level[1]);
177 goto mls_ops;
178 case CEXPR_H1L2:
179 l1 = &(scontext->range.level[1]);
180 l2 = &(tcontext->range.level[0]);
181 goto mls_ops;
182 case CEXPR_H1H2:
183 l1 = &(scontext->range.level[1]);
184 l2 = &(tcontext->range.level[1]);
185 goto mls_ops;
186 case CEXPR_L1H1:
187 l1 = &(scontext->range.level[0]);
188 l2 = &(scontext->range.level[1]);
189 goto mls_ops;
190 case CEXPR_L2H2:
191 l1 = &(tcontext->range.level[0]);
192 l2 = &(tcontext->range.level[1]);
193 goto mls_ops;
194 mls_ops:
195 switch (e->op) {
196 case CEXPR_EQ:
197 s[++sp] = mls_level_eq(l1, l2);
198 continue;
199 case CEXPR_NEQ:
200 s[++sp] = !mls_level_eq(l1, l2);
201 continue;
202 case CEXPR_DOM:
203 s[++sp] = mls_level_dom(l1, l2);
204 continue;
205 case CEXPR_DOMBY:
206 s[++sp] = mls_level_dom(l2, l1);
207 continue;
208 case CEXPR_INCOMP:
209 s[++sp] = mls_level_incomp(l2, l1);
210 continue;
211 default:
212 BUG();
213 return 0;
214 }
215 break;
216 default:
217 BUG();
218 return 0;
219 }
220
221 switch (e->op) {
222 case CEXPR_EQ:
223 s[++sp] = (val1 == val2);
224 break;
225 case CEXPR_NEQ:
226 s[++sp] = (val1 != val2);
227 break;
228 default:
229 BUG();
230 return 0;
231 }
232 break;
233 case CEXPR_NAMES:
234 if (sp == (CEXPR_MAXDEPTH-1))
235 return 0;
236 c = scontext;
237 if (e->attr & CEXPR_TARGET)
238 c = tcontext;
239 else if (e->attr & CEXPR_XTARGET) {
240 c = xcontext;
241 if (!c) {
242 BUG();
243 return 0;
244 }
245 }
246 if (e->attr & CEXPR_USER)
247 val1 = c->user;
248 else if (e->attr & CEXPR_ROLE)
249 val1 = c->role;
250 else if (e->attr & CEXPR_TYPE)
251 val1 = c->type;
252 else {
253 BUG();
254 return 0;
255 }
256
257 switch (e->op) {
258 case CEXPR_EQ:
259 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
260 break;
261 case CEXPR_NEQ:
262 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
263 break;
264 default:
265 BUG();
266 return 0;
267 }
268 break;
269 default:
270 BUG();
271 return 0;
272 }
273 }
274
275 BUG_ON(sp != 0);
276 return s[0];
277 }
278
279 /*
280 * Compute access vectors based on a context structure pair for
281 * the permissions in a particular class.
282 */
283 static int context_struct_compute_av(struct context *scontext,
284 struct context *tcontext,
285 u16 tclass,
286 u32 requested,
287 struct av_decision *avd)
288 {
289 struct constraint_node *constraint;
290 struct role_allow *ra;
291 struct avtab_key avkey;
292 struct avtab_node *node;
293 struct class_datum *tclass_datum;
294 struct ebitmap *sattr, *tattr;
295 struct ebitmap_node *snode, *tnode;
296 unsigned int i, j;
297
298 /*
299 * Remap extended Netlink classes for old policy versions.
300 * Do this here rather than socket_type_to_security_class()
301 * in case a newer policy version is loaded, allowing sockets
302 * to remain in the correct class.
303 */
304 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
305 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
306 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
307 tclass = SECCLASS_NETLINK_SOCKET;
308
309 if (!tclass || tclass > policydb.p_classes.nprim) {
310 printk(KERN_ERR "security_compute_av: unrecognized class %d\n",
311 tclass);
312 return -EINVAL;
313 }
314 tclass_datum = policydb.class_val_to_struct[tclass - 1];
315
316 /*
317 * Initialize the access vectors to the default values.
318 */
319 avd->allowed = 0;
320 avd->decided = 0xffffffff;
321 avd->auditallow = 0;
322 avd->auditdeny = 0xffffffff;
323 avd->seqno = latest_granting;
324
325 /*
326 * If a specific type enforcement rule was defined for
327 * this permission check, then use it.
328 */
329 avkey.target_class = tclass;
330 avkey.specified = AVTAB_AV;
331 sattr = &policydb.type_attr_map[scontext->type - 1];
332 tattr = &policydb.type_attr_map[tcontext->type - 1];
333 ebitmap_for_each_bit(sattr, snode, i) {
334 if (!ebitmap_node_get_bit(snode, i))
335 continue;
336 ebitmap_for_each_bit(tattr, tnode, j) {
337 if (!ebitmap_node_get_bit(tnode, j))
338 continue;
339 avkey.source_type = i + 1;
340 avkey.target_type = j + 1;
341 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
342 node != NULL;
343 node = avtab_search_node_next(node, avkey.specified)) {
344 if (node->key.specified == AVTAB_ALLOWED)
345 avd->allowed |= node->datum.data;
346 else if (node->key.specified == AVTAB_AUDITALLOW)
347 avd->auditallow |= node->datum.data;
348 else if (node->key.specified == AVTAB_AUDITDENY)
349 avd->auditdeny &= node->datum.data;
350 }
351
352 /* Check conditional av table for additional permissions */
353 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
354
355 }
356 }
357
358 /*
359 * Remove any permissions prohibited by a constraint (this includes
360 * the MLS policy).
361 */
362 constraint = tclass_datum->constraints;
363 while (constraint) {
364 if ((constraint->permissions & (avd->allowed)) &&
365 !constraint_expr_eval(scontext, tcontext, NULL,
366 constraint->expr)) {
367 avd->allowed = (avd->allowed) & ~(constraint->permissions);
368 }
369 constraint = constraint->next;
370 }
371
372 /*
373 * If checking process transition permission and the
374 * role is changing, then check the (current_role, new_role)
375 * pair.
376 */
377 if (tclass == SECCLASS_PROCESS &&
378 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
379 scontext->role != tcontext->role) {
380 for (ra = policydb.role_allow; ra; ra = ra->next) {
381 if (scontext->role == ra->role &&
382 tcontext->role == ra->new_role)
383 break;
384 }
385 if (!ra)
386 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
387 PROCESS__DYNTRANSITION);
388 }
389
390 return 0;
391 }
392
393 static int security_validtrans_handle_fail(struct context *ocontext,
394 struct context *ncontext,
395 struct context *tcontext,
396 u16 tclass)
397 {
398 char *o = NULL, *n = NULL, *t = NULL;
399 u32 olen, nlen, tlen;
400
401 if (context_struct_to_string(ocontext, &o, &olen) < 0)
402 goto out;
403 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
404 goto out;
405 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
406 goto out;
407 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
408 "security_validate_transition: denied for"
409 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
410 o, n, t, policydb.p_class_val_to_name[tclass-1]);
411 out:
412 kfree(o);
413 kfree(n);
414 kfree(t);
415
416 if (!selinux_enforcing)
417 return 0;
418 return -EPERM;
419 }
420
421 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
422 u16 tclass)
423 {
424 struct context *ocontext;
425 struct context *ncontext;
426 struct context *tcontext;
427 struct class_datum *tclass_datum;
428 struct constraint_node *constraint;
429 int rc = 0;
430
431 if (!ss_initialized)
432 return 0;
433
434 POLICY_RDLOCK;
435
436 /*
437 * Remap extended Netlink classes for old policy versions.
438 * Do this here rather than socket_type_to_security_class()
439 * in case a newer policy version is loaded, allowing sockets
440 * to remain in the correct class.
441 */
442 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
443 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
444 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
445 tclass = SECCLASS_NETLINK_SOCKET;
446
447 if (!tclass || tclass > policydb.p_classes.nprim) {
448 printk(KERN_ERR "security_validate_transition: "
449 "unrecognized class %d\n", tclass);
450 rc = -EINVAL;
451 goto out;
452 }
453 tclass_datum = policydb.class_val_to_struct[tclass - 1];
454
455 ocontext = sidtab_search(&sidtab, oldsid);
456 if (!ocontext) {
457 printk(KERN_ERR "security_validate_transition: "
458 " unrecognized SID %d\n", oldsid);
459 rc = -EINVAL;
460 goto out;
461 }
462
463 ncontext = sidtab_search(&sidtab, newsid);
464 if (!ncontext) {
465 printk(KERN_ERR "security_validate_transition: "
466 " unrecognized SID %d\n", newsid);
467 rc = -EINVAL;
468 goto out;
469 }
470
471 tcontext = sidtab_search(&sidtab, tasksid);
472 if (!tcontext) {
473 printk(KERN_ERR "security_validate_transition: "
474 " unrecognized SID %d\n", tasksid);
475 rc = -EINVAL;
476 goto out;
477 }
478
479 constraint = tclass_datum->validatetrans;
480 while (constraint) {
481 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
482 constraint->expr)) {
483 rc = security_validtrans_handle_fail(ocontext, ncontext,
484 tcontext, tclass);
485 goto out;
486 }
487 constraint = constraint->next;
488 }
489
490 out:
491 POLICY_RDUNLOCK;
492 return rc;
493 }
494
495 /**
496 * security_compute_av - Compute access vector decisions.
497 * @ssid: source security identifier
498 * @tsid: target security identifier
499 * @tclass: target security class
500 * @requested: requested permissions
501 * @avd: access vector decisions
502 *
503 * Compute a set of access vector decisions based on the
504 * SID pair (@ssid, @tsid) for the permissions in @tclass.
505 * Return -%EINVAL if any of the parameters are invalid or %0
506 * if the access vector decisions were computed successfully.
507 */
508 int security_compute_av(u32 ssid,
509 u32 tsid,
510 u16 tclass,
511 u32 requested,
512 struct av_decision *avd)
513 {
514 struct context *scontext = NULL, *tcontext = NULL;
515 int rc = 0;
516
517 if (!ss_initialized) {
518 avd->allowed = 0xffffffff;
519 avd->decided = 0xffffffff;
520 avd->auditallow = 0;
521 avd->auditdeny = 0xffffffff;
522 avd->seqno = latest_granting;
523 return 0;
524 }
525
526 POLICY_RDLOCK;
527
528 scontext = sidtab_search(&sidtab, ssid);
529 if (!scontext) {
530 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
531 ssid);
532 rc = -EINVAL;
533 goto out;
534 }
535 tcontext = sidtab_search(&sidtab, tsid);
536 if (!tcontext) {
537 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
538 tsid);
539 rc = -EINVAL;
540 goto out;
541 }
542
543 rc = context_struct_compute_av(scontext, tcontext, tclass,
544 requested, avd);
545 out:
546 POLICY_RDUNLOCK;
547 return rc;
548 }
549
550 /*
551 * Write the security context string representation of
552 * the context structure `context' into a dynamically
553 * allocated string of the correct size. Set `*scontext'
554 * to point to this string and set `*scontext_len' to
555 * the length of the string.
556 */
557 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
558 {
559 char *scontextp;
560
561 *scontext = NULL;
562 *scontext_len = 0;
563
564 /* Compute the size of the context. */
565 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
566 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
567 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
568 *scontext_len += mls_compute_context_len(context);
569
570 /* Allocate space for the context; caller must free this space. */
571 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
572 if (!scontextp) {
573 return -ENOMEM;
574 }
575 *scontext = scontextp;
576
577 /*
578 * Copy the user name, role name and type name into the context.
579 */
580 sprintf(scontextp, "%s:%s:%s",
581 policydb.p_user_val_to_name[context->user - 1],
582 policydb.p_role_val_to_name[context->role - 1],
583 policydb.p_type_val_to_name[context->type - 1]);
584 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
585 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
586 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
587
588 mls_sid_to_context(context, &scontextp);
589
590 *scontextp = 0;
591
592 return 0;
593 }
594
595 #include "initial_sid_to_string.h"
596
597 /**
598 * security_sid_to_context - Obtain a context for a given SID.
599 * @sid: security identifier, SID
600 * @scontext: security context
601 * @scontext_len: length in bytes
602 *
603 * Write the string representation of the context associated with @sid
604 * into a dynamically allocated string of the correct size. Set @scontext
605 * to point to this string and set @scontext_len to the length of the string.
606 */
607 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
608 {
609 struct context *context;
610 int rc = 0;
611
612 if (!ss_initialized) {
613 if (sid <= SECINITSID_NUM) {
614 char *scontextp;
615
616 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
617 scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
618 if (!scontextp) {
619 rc = -ENOMEM;
620 goto out;
621 }
622 strcpy(scontextp, initial_sid_to_string[sid]);
623 *scontext = scontextp;
624 goto out;
625 }
626 printk(KERN_ERR "security_sid_to_context: called before initial "
627 "load_policy on unknown SID %d\n", sid);
628 rc = -EINVAL;
629 goto out;
630 }
631 POLICY_RDLOCK;
632 context = sidtab_search(&sidtab, sid);
633 if (!context) {
634 printk(KERN_ERR "security_sid_to_context: unrecognized SID "
635 "%d\n", sid);
636 rc = -EINVAL;
637 goto out_unlock;
638 }
639 rc = context_struct_to_string(context, scontext, scontext_len);
640 out_unlock:
641 POLICY_RDUNLOCK;
642 out:
643 return rc;
644
645 }
646
647 static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
648 {
649 char *scontext2;
650 struct context context;
651 struct role_datum *role;
652 struct type_datum *typdatum;
653 struct user_datum *usrdatum;
654 char *scontextp, *p, oldc;
655 int rc = 0;
656
657 if (!ss_initialized) {
658 int i;
659
660 for (i = 1; i < SECINITSID_NUM; i++) {
661 if (!strcmp(initial_sid_to_string[i], scontext)) {
662 *sid = i;
663 goto out;
664 }
665 }
666 *sid = SECINITSID_KERNEL;
667 goto out;
668 }
669 *sid = SECSID_NULL;
670
671 /* Copy the string so that we can modify the copy as we parse it.
672 The string should already by null terminated, but we append a
673 null suffix to the copy to avoid problems with the existing
674 attr package, which doesn't view the null terminator as part
675 of the attribute value. */
676 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
677 if (!scontext2) {
678 rc = -ENOMEM;
679 goto out;
680 }
681 memcpy(scontext2, scontext, scontext_len);
682 scontext2[scontext_len] = 0;
683
684 context_init(&context);
685 *sid = SECSID_NULL;
686
687 POLICY_RDLOCK;
688
689 /* Parse the security context. */
690
691 rc = -EINVAL;
692 scontextp = (char *) scontext2;
693
694 /* Extract the user. */
695 p = scontextp;
696 while (*p && *p != ':')
697 p++;
698
699 if (*p == 0)
700 goto out_unlock;
701
702 *p++ = 0;
703
704 usrdatum = hashtab_search(policydb.p_users.table, scontextp);
705 if (!usrdatum)
706 goto out_unlock;
707
708 context.user = usrdatum->value;
709
710 /* Extract role. */
711 scontextp = p;
712 while (*p && *p != ':')
713 p++;
714
715 if (*p == 0)
716 goto out_unlock;
717
718 *p++ = 0;
719
720 role = hashtab_search(policydb.p_roles.table, scontextp);
721 if (!role)
722 goto out_unlock;
723 context.role = role->value;
724
725 /* Extract type. */
726 scontextp = p;
727 while (*p && *p != ':')
728 p++;
729 oldc = *p;
730 *p++ = 0;
731
732 typdatum = hashtab_search(policydb.p_types.table, scontextp);
733 if (!typdatum)
734 goto out_unlock;
735
736 context.type = typdatum->value;
737
738 rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
739 if (rc)
740 goto out_unlock;
741
742 if ((p - scontext2) < scontext_len) {
743 rc = -EINVAL;
744 goto out_unlock;
745 }
746
747 /* Check the validity of the new context. */
748 if (!policydb_context_isvalid(&policydb, &context)) {
749 rc = -EINVAL;
750 goto out_unlock;
751 }
752 /* Obtain the new sid. */
753 rc = sidtab_context_to_sid(&sidtab, &context, sid);
754 out_unlock:
755 POLICY_RDUNLOCK;
756 context_destroy(&context);
757 kfree(scontext2);
758 out:
759 return rc;
760 }
761
762 /**
763 * security_context_to_sid - Obtain a SID for a given security context.
764 * @scontext: security context
765 * @scontext_len: length in bytes
766 * @sid: security identifier, SID
767 *
768 * Obtains a SID associated with the security context that
769 * has the string representation specified by @scontext.
770 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
771 * memory is available, or 0 on success.
772 */
773 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
774 {
775 return security_context_to_sid_core(scontext, scontext_len,
776 sid, SECSID_NULL);
777 }
778
779 /**
780 * security_context_to_sid_default - Obtain a SID for a given security context,
781 * falling back to specified default if needed.
782 *
783 * @scontext: security context
784 * @scontext_len: length in bytes
785 * @sid: security identifier, SID
786 * @def_sid: default SID to assign on errror
787 *
788 * Obtains a SID associated with the security context that
789 * has the string representation specified by @scontext.
790 * The default SID is passed to the MLS layer to be used to allow
791 * kernel labeling of the MLS field if the MLS field is not present
792 * (for upgrading to MLS without full relabel).
793 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
794 * memory is available, or 0 on success.
795 */
796 int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
797 {
798 return security_context_to_sid_core(scontext, scontext_len,
799 sid, def_sid);
800 }
801
802 static int compute_sid_handle_invalid_context(
803 struct context *scontext,
804 struct context *tcontext,
805 u16 tclass,
806 struct context *newcontext)
807 {
808 char *s = NULL, *t = NULL, *n = NULL;
809 u32 slen, tlen, nlen;
810
811 if (context_struct_to_string(scontext, &s, &slen) < 0)
812 goto out;
813 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
814 goto out;
815 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
816 goto out;
817 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
818 "security_compute_sid: invalid context %s"
819 " for scontext=%s"
820 " tcontext=%s"
821 " tclass=%s",
822 n, s, t, policydb.p_class_val_to_name[tclass-1]);
823 out:
824 kfree(s);
825 kfree(t);
826 kfree(n);
827 if (!selinux_enforcing)
828 return 0;
829 return -EACCES;
830 }
831
832 static int security_compute_sid(u32 ssid,
833 u32 tsid,
834 u16 tclass,
835 u32 specified,
836 u32 *out_sid)
837 {
838 struct context *scontext = NULL, *tcontext = NULL, newcontext;
839 struct role_trans *roletr = NULL;
840 struct avtab_key avkey;
841 struct avtab_datum *avdatum;
842 struct avtab_node *node;
843 int rc = 0;
844
845 if (!ss_initialized) {
846 switch (tclass) {
847 case SECCLASS_PROCESS:
848 *out_sid = ssid;
849 break;
850 default:
851 *out_sid = tsid;
852 break;
853 }
854 goto out;
855 }
856
857 context_init(&newcontext);
858
859 POLICY_RDLOCK;
860
861 scontext = sidtab_search(&sidtab, ssid);
862 if (!scontext) {
863 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
864 ssid);
865 rc = -EINVAL;
866 goto out_unlock;
867 }
868 tcontext = sidtab_search(&sidtab, tsid);
869 if (!tcontext) {
870 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
871 tsid);
872 rc = -EINVAL;
873 goto out_unlock;
874 }
875
876 /* Set the user identity. */
877 switch (specified) {
878 case AVTAB_TRANSITION:
879 case AVTAB_CHANGE:
880 /* Use the process user identity. */
881 newcontext.user = scontext->user;
882 break;
883 case AVTAB_MEMBER:
884 /* Use the related object owner. */
885 newcontext.user = tcontext->user;
886 break;
887 }
888
889 /* Set the role and type to default values. */
890 switch (tclass) {
891 case SECCLASS_PROCESS:
892 /* Use the current role and type of process. */
893 newcontext.role = scontext->role;
894 newcontext.type = scontext->type;
895 break;
896 default:
897 /* Use the well-defined object role. */
898 newcontext.role = OBJECT_R_VAL;
899 /* Use the type of the related object. */
900 newcontext.type = tcontext->type;
901 }
902
903 /* Look for a type transition/member/change rule. */
904 avkey.source_type = scontext->type;
905 avkey.target_type = tcontext->type;
906 avkey.target_class = tclass;
907 avkey.specified = specified;
908 avdatum = avtab_search(&policydb.te_avtab, &avkey);
909
910 /* If no permanent rule, also check for enabled conditional rules */
911 if(!avdatum) {
912 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
913 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
914 if (node->key.specified & AVTAB_ENABLED) {
915 avdatum = &node->datum;
916 break;
917 }
918 }
919 }
920
921 if (avdatum) {
922 /* Use the type from the type transition/member/change rule. */
923 newcontext.type = avdatum->data;
924 }
925
926 /* Check for class-specific changes. */
927 switch (tclass) {
928 case SECCLASS_PROCESS:
929 if (specified & AVTAB_TRANSITION) {
930 /* Look for a role transition rule. */
931 for (roletr = policydb.role_tr; roletr;
932 roletr = roletr->next) {
933 if (roletr->role == scontext->role &&
934 roletr->type == tcontext->type) {
935 /* Use the role transition rule. */
936 newcontext.role = roletr->new_role;
937 break;
938 }
939 }
940 }
941 break;
942 default:
943 break;
944 }
945
946 /* Set the MLS attributes.
947 This is done last because it may allocate memory. */
948 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
949 if (rc)
950 goto out_unlock;
951
952 /* Check the validity of the context. */
953 if (!policydb_context_isvalid(&policydb, &newcontext)) {
954 rc = compute_sid_handle_invalid_context(scontext,
955 tcontext,
956 tclass,
957 &newcontext);
958 if (rc)
959 goto out_unlock;
960 }
961 /* Obtain the sid for the context. */
962 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
963 out_unlock:
964 POLICY_RDUNLOCK;
965 context_destroy(&newcontext);
966 out:
967 return rc;
968 }
969
970 /**
971 * security_transition_sid - Compute the SID for a new subject/object.
972 * @ssid: source security identifier
973 * @tsid: target security identifier
974 * @tclass: target security class
975 * @out_sid: security identifier for new subject/object
976 *
977 * Compute a SID to use for labeling a new subject or object in the
978 * class @tclass based on a SID pair (@ssid, @tsid).
979 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
980 * if insufficient memory is available, or %0 if the new SID was
981 * computed successfully.
982 */
983 int security_transition_sid(u32 ssid,
984 u32 tsid,
985 u16 tclass,
986 u32 *out_sid)
987 {
988 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
989 }
990
991 /**
992 * security_member_sid - Compute the SID for member selection.
993 * @ssid: source security identifier
994 * @tsid: target security identifier
995 * @tclass: target security class
996 * @out_sid: security identifier for selected member
997 *
998 * Compute a SID to use when selecting a member of a polyinstantiated
999 * object of class @tclass based on a SID pair (@ssid, @tsid).
1000 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1001 * if insufficient memory is available, or %0 if the SID was
1002 * computed successfully.
1003 */
1004 int security_member_sid(u32 ssid,
1005 u32 tsid,
1006 u16 tclass,
1007 u32 *out_sid)
1008 {
1009 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1010 }
1011
1012 /**
1013 * security_change_sid - Compute the SID for object relabeling.
1014 * @ssid: source security identifier
1015 * @tsid: target security identifier
1016 * @tclass: target security class
1017 * @out_sid: security identifier for selected member
1018 *
1019 * Compute a SID to use for relabeling an object of class @tclass
1020 * based on a SID pair (@ssid, @tsid).
1021 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1022 * if insufficient memory is available, or %0 if the SID was
1023 * computed successfully.
1024 */
1025 int security_change_sid(u32 ssid,
1026 u32 tsid,
1027 u16 tclass,
1028 u32 *out_sid)
1029 {
1030 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1031 }
1032
1033 /*
1034 * Verify that each kernel class that is defined in the
1035 * policy is correct
1036 */
1037 static int validate_classes(struct policydb *p)
1038 {
1039 int i, j;
1040 struct class_datum *cladatum;
1041 struct perm_datum *perdatum;
1042 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1043 u16 class_val;
1044 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1045 const char *def_class, *def_perm, *pol_class;
1046 struct symtab *perms;
1047
1048 for (i = 1; i < kdefs->cts_len; i++) {
1049 def_class = kdefs->class_to_string[i];
1050 if (i > p->p_classes.nprim) {
1051 printk(KERN_INFO
1052 "security: class %s not defined in policy\n",
1053 def_class);
1054 continue;
1055 }
1056 pol_class = p->p_class_val_to_name[i-1];
1057 if (strcmp(pol_class, def_class)) {
1058 printk(KERN_ERR
1059 "security: class %d is incorrect, found %s but should be %s\n",
1060 i, pol_class, def_class);
1061 return -EINVAL;
1062 }
1063 }
1064 for (i = 0; i < kdefs->av_pts_len; i++) {
1065 class_val = kdefs->av_perm_to_string[i].tclass;
1066 perm_val = kdefs->av_perm_to_string[i].value;
1067 def_perm = kdefs->av_perm_to_string[i].name;
1068 if (class_val > p->p_classes.nprim)
1069 continue;
1070 pol_class = p->p_class_val_to_name[class_val-1];
1071 cladatum = hashtab_search(p->p_classes.table, pol_class);
1072 BUG_ON(!cladatum);
1073 perms = &cladatum->permissions;
1074 nprim = 1 << (perms->nprim - 1);
1075 if (perm_val > nprim) {
1076 printk(KERN_INFO
1077 "security: permission %s in class %s not defined in policy\n",
1078 def_perm, pol_class);
1079 continue;
1080 }
1081 perdatum = hashtab_search(perms->table, def_perm);
1082 if (perdatum == NULL) {
1083 printk(KERN_ERR
1084 "security: permission %s in class %s not found in policy\n",
1085 def_perm, pol_class);
1086 return -EINVAL;
1087 }
1088 pol_val = 1 << (perdatum->value - 1);
1089 if (pol_val != perm_val) {
1090 printk(KERN_ERR
1091 "security: permission %s in class %s has incorrect value\n",
1092 def_perm, pol_class);
1093 return -EINVAL;
1094 }
1095 }
1096 for (i = 0; i < kdefs->av_inherit_len; i++) {
1097 class_val = kdefs->av_inherit[i].tclass;
1098 if (class_val > p->p_classes.nprim)
1099 continue;
1100 pol_class = p->p_class_val_to_name[class_val-1];
1101 cladatum = hashtab_search(p->p_classes.table, pol_class);
1102 BUG_ON(!cladatum);
1103 if (!cladatum->comdatum) {
1104 printk(KERN_ERR
1105 "security: class %s should have an inherits clause but does not\n",
1106 pol_class);
1107 return -EINVAL;
1108 }
1109 tmp = kdefs->av_inherit[i].common_base;
1110 common_pts_len = 0;
1111 while (!(tmp & 0x01)) {
1112 common_pts_len++;
1113 tmp >>= 1;
1114 }
1115 perms = &cladatum->comdatum->permissions;
1116 for (j = 0; j < common_pts_len; j++) {
1117 def_perm = kdefs->av_inherit[i].common_pts[j];
1118 if (j >= perms->nprim) {
1119 printk(KERN_INFO
1120 "security: permission %s in class %s not defined in policy\n",
1121 def_perm, pol_class);
1122 continue;
1123 }
1124 perdatum = hashtab_search(perms->table, def_perm);
1125 if (perdatum == NULL) {
1126 printk(KERN_ERR
1127 "security: permission %s in class %s not found in policy\n",
1128 def_perm, pol_class);
1129 return -EINVAL;
1130 }
1131 if (perdatum->value != j + 1) {
1132 printk(KERN_ERR
1133 "security: permission %s in class %s has incorrect value\n",
1134 def_perm, pol_class);
1135 return -EINVAL;
1136 }
1137 }
1138 }
1139 return 0;
1140 }
1141
1142 /* Clone the SID into the new SID table. */
1143 static int clone_sid(u32 sid,
1144 struct context *context,
1145 void *arg)
1146 {
1147 struct sidtab *s = arg;
1148
1149 return sidtab_insert(s, sid, context);
1150 }
1151
1152 static inline int convert_context_handle_invalid_context(struct context *context)
1153 {
1154 int rc = 0;
1155
1156 if (selinux_enforcing) {
1157 rc = -EINVAL;
1158 } else {
1159 char *s;
1160 u32 len;
1161
1162 context_struct_to_string(context, &s, &len);
1163 printk(KERN_ERR "security: context %s is invalid\n", s);
1164 kfree(s);
1165 }
1166 return rc;
1167 }
1168
1169 struct convert_context_args {
1170 struct policydb *oldp;
1171 struct policydb *newp;
1172 };
1173
1174 /*
1175 * Convert the values in the security context
1176 * structure `c' from the values specified
1177 * in the policy `p->oldp' to the values specified
1178 * in the policy `p->newp'. Verify that the
1179 * context is valid under the new policy.
1180 */
1181 static int convert_context(u32 key,
1182 struct context *c,
1183 void *p)
1184 {
1185 struct convert_context_args *args;
1186 struct context oldc;
1187 struct role_datum *role;
1188 struct type_datum *typdatum;
1189 struct user_datum *usrdatum;
1190 char *s;
1191 u32 len;
1192 int rc;
1193
1194 args = p;
1195
1196 rc = context_cpy(&oldc, c);
1197 if (rc)
1198 goto out;
1199
1200 rc = -EINVAL;
1201
1202 /* Convert the user. */
1203 usrdatum = hashtab_search(args->newp->p_users.table,
1204 args->oldp->p_user_val_to_name[c->user - 1]);
1205 if (!usrdatum) {
1206 goto bad;
1207 }
1208 c->user = usrdatum->value;
1209
1210 /* Convert the role. */
1211 role = hashtab_search(args->newp->p_roles.table,
1212 args->oldp->p_role_val_to_name[c->role - 1]);
1213 if (!role) {
1214 goto bad;
1215 }
1216 c->role = role->value;
1217
1218 /* Convert the type. */
1219 typdatum = hashtab_search(args->newp->p_types.table,
1220 args->oldp->p_type_val_to_name[c->type - 1]);
1221 if (!typdatum) {
1222 goto bad;
1223 }
1224 c->type = typdatum->value;
1225
1226 rc = mls_convert_context(args->oldp, args->newp, c);
1227 if (rc)
1228 goto bad;
1229
1230 /* Check the validity of the new context. */
1231 if (!policydb_context_isvalid(args->newp, c)) {
1232 rc = convert_context_handle_invalid_context(&oldc);
1233 if (rc)
1234 goto bad;
1235 }
1236
1237 context_destroy(&oldc);
1238 out:
1239 return rc;
1240 bad:
1241 context_struct_to_string(&oldc, &s, &len);
1242 context_destroy(&oldc);
1243 printk(KERN_ERR "security: invalidating context %s\n", s);
1244 kfree(s);
1245 goto out;
1246 }
1247
1248 extern void selinux_complete_init(void);
1249
1250 /**
1251 * security_load_policy - Load a security policy configuration.
1252 * @data: binary policy data
1253 * @len: length of data in bytes
1254 *
1255 * Load a new set of security policy configuration data,
1256 * validate it and convert the SID table as necessary.
1257 * This function will flush the access vector cache after
1258 * loading the new policy.
1259 */
1260 int security_load_policy(void *data, size_t len)
1261 {
1262 struct policydb oldpolicydb, newpolicydb;
1263 struct sidtab oldsidtab, newsidtab;
1264 struct convert_context_args args;
1265 u32 seqno;
1266 int rc = 0;
1267 struct policy_file file = { data, len }, *fp = &file;
1268
1269 LOAD_LOCK;
1270
1271 if (!ss_initialized) {
1272 avtab_cache_init();
1273 if (policydb_read(&policydb, fp)) {
1274 LOAD_UNLOCK;
1275 avtab_cache_destroy();
1276 return -EINVAL;
1277 }
1278 if (policydb_load_isids(&policydb, &sidtab)) {
1279 LOAD_UNLOCK;
1280 policydb_destroy(&policydb);
1281 avtab_cache_destroy();
1282 return -EINVAL;
1283 }
1284 /* Verify that the kernel defined classes are correct. */
1285 if (validate_classes(&policydb)) {
1286 printk(KERN_ERR
1287 "security: the definition of a class is incorrect\n");
1288 LOAD_UNLOCK;
1289 sidtab_destroy(&sidtab);
1290 policydb_destroy(&policydb);
1291 avtab_cache_destroy();
1292 return -EINVAL;
1293 }
1294 policydb_loaded_version = policydb.policyvers;
1295 ss_initialized = 1;
1296 seqno = ++latest_granting;
1297 LOAD_UNLOCK;
1298 selinux_complete_init();
1299 avc_ss_reset(seqno);
1300 selnl_notify_policyload(seqno);
1301 selinux_netlbl_cache_invalidate();
1302 selinux_xfrm_notify_policyload();
1303 return 0;
1304 }
1305
1306 #if 0
1307 sidtab_hash_eval(&sidtab, "sids");
1308 #endif
1309
1310 if (policydb_read(&newpolicydb, fp)) {
1311 LOAD_UNLOCK;
1312 return -EINVAL;
1313 }
1314
1315 sidtab_init(&newsidtab);
1316
1317 /* Verify that the kernel defined classes are correct. */
1318 if (validate_classes(&newpolicydb)) {
1319 printk(KERN_ERR
1320 "security: the definition of a class is incorrect\n");
1321 rc = -EINVAL;
1322 goto err;
1323 }
1324
1325 /* Clone the SID table. */
1326 sidtab_shutdown(&sidtab);
1327 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1328 rc = -ENOMEM;
1329 goto err;
1330 }
1331
1332 /* Convert the internal representations of contexts
1333 in the new SID table and remove invalid SIDs. */
1334 args.oldp = &policydb;
1335 args.newp = &newpolicydb;
1336 sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1337
1338 /* Save the old policydb and SID table to free later. */
1339 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1340 sidtab_set(&oldsidtab, &sidtab);
1341
1342 /* Install the new policydb and SID table. */
1343 POLICY_WRLOCK;
1344 memcpy(&policydb, &newpolicydb, sizeof policydb);
1345 sidtab_set(&sidtab, &newsidtab);
1346 seqno = ++latest_granting;
1347 policydb_loaded_version = policydb.policyvers;
1348 POLICY_WRUNLOCK;
1349 LOAD_UNLOCK;
1350
1351 /* Free the old policydb and SID table. */
1352 policydb_destroy(&oldpolicydb);
1353 sidtab_destroy(&oldsidtab);
1354
1355 avc_ss_reset(seqno);
1356 selnl_notify_policyload(seqno);
1357 selinux_netlbl_cache_invalidate();
1358 selinux_xfrm_notify_policyload();
1359
1360 return 0;
1361
1362 err:
1363 LOAD_UNLOCK;
1364 sidtab_destroy(&newsidtab);
1365 policydb_destroy(&newpolicydb);
1366 return rc;
1367
1368 }
1369
1370 /**
1371 * security_port_sid - Obtain the SID for a port.
1372 * @domain: communication domain aka address family
1373 * @type: socket type
1374 * @protocol: protocol number
1375 * @port: port number
1376 * @out_sid: security identifier
1377 */
1378 int security_port_sid(u16 domain,
1379 u16 type,
1380 u8 protocol,
1381 u16 port,
1382 u32 *out_sid)
1383 {
1384 struct ocontext *c;
1385 int rc = 0;
1386
1387 POLICY_RDLOCK;
1388
1389 c = policydb.ocontexts[OCON_PORT];
1390 while (c) {
1391 if (c->u.port.protocol == protocol &&
1392 c->u.port.low_port <= port &&
1393 c->u.port.high_port >= port)
1394 break;
1395 c = c->next;
1396 }
1397
1398 if (c) {
1399 if (!c->sid[0]) {
1400 rc = sidtab_context_to_sid(&sidtab,
1401 &c->context[0],
1402 &c->sid[0]);
1403 if (rc)
1404 goto out;
1405 }
1406 *out_sid = c->sid[0];
1407 } else {
1408 *out_sid = SECINITSID_PORT;
1409 }
1410
1411 out:
1412 POLICY_RDUNLOCK;
1413 return rc;
1414 }
1415
1416 /**
1417 * security_netif_sid - Obtain the SID for a network interface.
1418 * @name: interface name
1419 * @if_sid: interface SID
1420 * @msg_sid: default SID for received packets
1421 */
1422 int security_netif_sid(char *name,
1423 u32 *if_sid,
1424 u32 *msg_sid)
1425 {
1426 int rc = 0;
1427 struct ocontext *c;
1428
1429 POLICY_RDLOCK;
1430
1431 c = policydb.ocontexts[OCON_NETIF];
1432 while (c) {
1433 if (strcmp(name, c->u.name) == 0)
1434 break;
1435 c = c->next;
1436 }
1437
1438 if (c) {
1439 if (!c->sid[0] || !c->sid[1]) {
1440 rc = sidtab_context_to_sid(&sidtab,
1441 &c->context[0],
1442 &c->sid[0]);
1443 if (rc)
1444 goto out;
1445 rc = sidtab_context_to_sid(&sidtab,
1446 &c->context[1],
1447 &c->sid[1]);
1448 if (rc)
1449 goto out;
1450 }
1451 *if_sid = c->sid[0];
1452 *msg_sid = c->sid[1];
1453 } else {
1454 *if_sid = SECINITSID_NETIF;
1455 *msg_sid = SECINITSID_NETMSG;
1456 }
1457
1458 out:
1459 POLICY_RDUNLOCK;
1460 return rc;
1461 }
1462
1463 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1464 {
1465 int i, fail = 0;
1466
1467 for(i = 0; i < 4; i++)
1468 if(addr[i] != (input[i] & mask[i])) {
1469 fail = 1;
1470 break;
1471 }
1472
1473 return !fail;
1474 }
1475
1476 /**
1477 * security_node_sid - Obtain the SID for a node (host).
1478 * @domain: communication domain aka address family
1479 * @addrp: address
1480 * @addrlen: address length in bytes
1481 * @out_sid: security identifier
1482 */
1483 int security_node_sid(u16 domain,
1484 void *addrp,
1485 u32 addrlen,
1486 u32 *out_sid)
1487 {
1488 int rc = 0;
1489 struct ocontext *c;
1490
1491 POLICY_RDLOCK;
1492
1493 switch (domain) {
1494 case AF_INET: {
1495 u32 addr;
1496
1497 if (addrlen != sizeof(u32)) {
1498 rc = -EINVAL;
1499 goto out;
1500 }
1501
1502 addr = *((u32 *)addrp);
1503
1504 c = policydb.ocontexts[OCON_NODE];
1505 while (c) {
1506 if (c->u.node.addr == (addr & c->u.node.mask))
1507 break;
1508 c = c->next;
1509 }
1510 break;
1511 }
1512
1513 case AF_INET6:
1514 if (addrlen != sizeof(u64) * 2) {
1515 rc = -EINVAL;
1516 goto out;
1517 }
1518 c = policydb.ocontexts[OCON_NODE6];
1519 while (c) {
1520 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1521 c->u.node6.mask))
1522 break;
1523 c = c->next;
1524 }
1525 break;
1526
1527 default:
1528 *out_sid = SECINITSID_NODE;
1529 goto out;
1530 }
1531
1532 if (c) {
1533 if (!c->sid[0]) {
1534 rc = sidtab_context_to_sid(&sidtab,
1535 &c->context[0],
1536 &c->sid[0]);
1537 if (rc)
1538 goto out;
1539 }
1540 *out_sid = c->sid[0];
1541 } else {
1542 *out_sid = SECINITSID_NODE;
1543 }
1544
1545 out:
1546 POLICY_RDUNLOCK;
1547 return rc;
1548 }
1549
1550 #define SIDS_NEL 25
1551
1552 /**
1553 * security_get_user_sids - Obtain reachable SIDs for a user.
1554 * @fromsid: starting SID
1555 * @username: username
1556 * @sids: array of reachable SIDs for user
1557 * @nel: number of elements in @sids
1558 *
1559 * Generate the set of SIDs for legal security contexts
1560 * for a given user that can be reached by @fromsid.
1561 * Set *@sids to point to a dynamically allocated
1562 * array containing the set of SIDs. Set *@nel to the
1563 * number of elements in the array.
1564 */
1565
1566 int security_get_user_sids(u32 fromsid,
1567 char *username,
1568 u32 **sids,
1569 u32 *nel)
1570 {
1571 struct context *fromcon, usercon;
1572 u32 *mysids, *mysids2, sid;
1573 u32 mynel = 0, maxnel = SIDS_NEL;
1574 struct user_datum *user;
1575 struct role_datum *role;
1576 struct av_decision avd;
1577 struct ebitmap_node *rnode, *tnode;
1578 int rc = 0, i, j;
1579
1580 if (!ss_initialized) {
1581 *sids = NULL;
1582 *nel = 0;
1583 goto out;
1584 }
1585
1586 POLICY_RDLOCK;
1587
1588 fromcon = sidtab_search(&sidtab, fromsid);
1589 if (!fromcon) {
1590 rc = -EINVAL;
1591 goto out_unlock;
1592 }
1593
1594 user = hashtab_search(policydb.p_users.table, username);
1595 if (!user) {
1596 rc = -EINVAL;
1597 goto out_unlock;
1598 }
1599 usercon.user = user->value;
1600
1601 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1602 if (!mysids) {
1603 rc = -ENOMEM;
1604 goto out_unlock;
1605 }
1606
1607 ebitmap_for_each_bit(&user->roles, rnode, i) {
1608 if (!ebitmap_node_get_bit(rnode, i))
1609 continue;
1610 role = policydb.role_val_to_struct[i];
1611 usercon.role = i+1;
1612 ebitmap_for_each_bit(&role->types, tnode, j) {
1613 if (!ebitmap_node_get_bit(tnode, j))
1614 continue;
1615 usercon.type = j+1;
1616
1617 if (mls_setup_user_range(fromcon, user, &usercon))
1618 continue;
1619
1620 rc = context_struct_compute_av(fromcon, &usercon,
1621 SECCLASS_PROCESS,
1622 PROCESS__TRANSITION,
1623 &avd);
1624 if (rc || !(avd.allowed & PROCESS__TRANSITION))
1625 continue;
1626 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1627 if (rc) {
1628 kfree(mysids);
1629 goto out_unlock;
1630 }
1631 if (mynel < maxnel) {
1632 mysids[mynel++] = sid;
1633 } else {
1634 maxnel += SIDS_NEL;
1635 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1636 if (!mysids2) {
1637 rc = -ENOMEM;
1638 kfree(mysids);
1639 goto out_unlock;
1640 }
1641 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1642 kfree(mysids);
1643 mysids = mysids2;
1644 mysids[mynel++] = sid;
1645 }
1646 }
1647 }
1648
1649 *sids = mysids;
1650 *nel = mynel;
1651
1652 out_unlock:
1653 POLICY_RDUNLOCK;
1654 out:
1655 return rc;
1656 }
1657
1658 /**
1659 * security_genfs_sid - Obtain a SID for a file in a filesystem
1660 * @fstype: filesystem type
1661 * @path: path from root of mount
1662 * @sclass: file security class
1663 * @sid: SID for path
1664 *
1665 * Obtain a SID to use for a file in a filesystem that
1666 * cannot support xattr or use a fixed labeling behavior like
1667 * transition SIDs or task SIDs.
1668 */
1669 int security_genfs_sid(const char *fstype,
1670 char *path,
1671 u16 sclass,
1672 u32 *sid)
1673 {
1674 int len;
1675 struct genfs *genfs;
1676 struct ocontext *c;
1677 int rc = 0, cmp = 0;
1678
1679 POLICY_RDLOCK;
1680
1681 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1682 cmp = strcmp(fstype, genfs->fstype);
1683 if (cmp <= 0)
1684 break;
1685 }
1686
1687 if (!genfs || cmp) {
1688 *sid = SECINITSID_UNLABELED;
1689 rc = -ENOENT;
1690 goto out;
1691 }
1692
1693 for (c = genfs->head; c; c = c->next) {
1694 len = strlen(c->u.name);
1695 if ((!c->v.sclass || sclass == c->v.sclass) &&
1696 (strncmp(c->u.name, path, len) == 0))
1697 break;
1698 }
1699
1700 if (!c) {
1701 *sid = SECINITSID_UNLABELED;
1702 rc = -ENOENT;
1703 goto out;
1704 }
1705
1706 if (!c->sid[0]) {
1707 rc = sidtab_context_to_sid(&sidtab,
1708 &c->context[0],
1709 &c->sid[0]);
1710 if (rc)
1711 goto out;
1712 }
1713
1714 *sid = c->sid[0];
1715 out:
1716 POLICY_RDUNLOCK;
1717 return rc;
1718 }
1719
1720 /**
1721 * security_fs_use - Determine how to handle labeling for a filesystem.
1722 * @fstype: filesystem type
1723 * @behavior: labeling behavior
1724 * @sid: SID for filesystem (superblock)
1725 */
1726 int security_fs_use(
1727 const char *fstype,
1728 unsigned int *behavior,
1729 u32 *sid)
1730 {
1731 int rc = 0;
1732 struct ocontext *c;
1733
1734 POLICY_RDLOCK;
1735
1736 c = policydb.ocontexts[OCON_FSUSE];
1737 while (c) {
1738 if (strcmp(fstype, c->u.name) == 0)
1739 break;
1740 c = c->next;
1741 }
1742
1743 if (c) {
1744 *behavior = c->v.behavior;
1745 if (!c->sid[0]) {
1746 rc = sidtab_context_to_sid(&sidtab,
1747 &c->context[0],
1748 &c->sid[0]);
1749 if (rc)
1750 goto out;
1751 }
1752 *sid = c->sid[0];
1753 } else {
1754 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1755 if (rc) {
1756 *behavior = SECURITY_FS_USE_NONE;
1757 rc = 0;
1758 } else {
1759 *behavior = SECURITY_FS_USE_GENFS;
1760 }
1761 }
1762
1763 out:
1764 POLICY_RDUNLOCK;
1765 return rc;
1766 }
1767
1768 int security_get_bools(int *len, char ***names, int **values)
1769 {
1770 int i, rc = -ENOMEM;
1771
1772 POLICY_RDLOCK;
1773 *names = NULL;
1774 *values = NULL;
1775
1776 *len = policydb.p_bools.nprim;
1777 if (!*len) {
1778 rc = 0;
1779 goto out;
1780 }
1781
1782 *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1783 if (!*names)
1784 goto err;
1785
1786 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1787 if (!*values)
1788 goto err;
1789
1790 for (i = 0; i < *len; i++) {
1791 size_t name_len;
1792 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1793 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1794 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1795 if (!(*names)[i])
1796 goto err;
1797 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1798 (*names)[i][name_len - 1] = 0;
1799 }
1800 rc = 0;
1801 out:
1802 POLICY_RDUNLOCK;
1803 return rc;
1804 err:
1805 if (*names) {
1806 for (i = 0; i < *len; i++)
1807 kfree((*names)[i]);
1808 }
1809 kfree(*values);
1810 goto out;
1811 }
1812
1813
1814 int security_set_bools(int len, int *values)
1815 {
1816 int i, rc = 0;
1817 int lenp, seqno = 0;
1818 struct cond_node *cur;
1819
1820 POLICY_WRLOCK;
1821
1822 lenp = policydb.p_bools.nprim;
1823 if (len != lenp) {
1824 rc = -EFAULT;
1825 goto out;
1826 }
1827
1828 for (i = 0; i < len; i++) {
1829 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1830 audit_log(current->audit_context, GFP_ATOMIC,
1831 AUDIT_MAC_CONFIG_CHANGE,
1832 "bool=%s val=%d old_val=%d auid=%u",
1833 policydb.p_bool_val_to_name[i],
1834 !!values[i],
1835 policydb.bool_val_to_struct[i]->state,
1836 audit_get_loginuid(current->audit_context));
1837 }
1838 if (values[i]) {
1839 policydb.bool_val_to_struct[i]->state = 1;
1840 } else {
1841 policydb.bool_val_to_struct[i]->state = 0;
1842 }
1843 }
1844
1845 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1846 rc = evaluate_cond_node(&policydb, cur);
1847 if (rc)
1848 goto out;
1849 }
1850
1851 seqno = ++latest_granting;
1852
1853 out:
1854 POLICY_WRUNLOCK;
1855 if (!rc) {
1856 avc_ss_reset(seqno);
1857 selnl_notify_policyload(seqno);
1858 selinux_xfrm_notify_policyload();
1859 }
1860 return rc;
1861 }
1862
1863 int security_get_bool_value(int bool)
1864 {
1865 int rc = 0;
1866 int len;
1867
1868 POLICY_RDLOCK;
1869
1870 len = policydb.p_bools.nprim;
1871 if (bool >= len) {
1872 rc = -EFAULT;
1873 goto out;
1874 }
1875
1876 rc = policydb.bool_val_to_struct[bool]->state;
1877 out:
1878 POLICY_RDUNLOCK;
1879 return rc;
1880 }
1881
1882 /*
1883 * security_sid_mls_copy() - computes a new sid based on the given
1884 * sid and the mls portion of mls_sid.
1885 */
1886 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1887 {
1888 struct context *context1;
1889 struct context *context2;
1890 struct context newcon;
1891 char *s;
1892 u32 len;
1893 int rc = 0;
1894
1895 if (!ss_initialized || !selinux_mls_enabled) {
1896 *new_sid = sid;
1897 goto out;
1898 }
1899
1900 context_init(&newcon);
1901
1902 POLICY_RDLOCK;
1903 context1 = sidtab_search(&sidtab, sid);
1904 if (!context1) {
1905 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1906 "%d\n", sid);
1907 rc = -EINVAL;
1908 goto out_unlock;
1909 }
1910
1911 context2 = sidtab_search(&sidtab, mls_sid);
1912 if (!context2) {
1913 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1914 "%d\n", mls_sid);
1915 rc = -EINVAL;
1916 goto out_unlock;
1917 }
1918
1919 newcon.user = context1->user;
1920 newcon.role = context1->role;
1921 newcon.type = context1->type;
1922 rc = mls_context_cpy(&newcon, context2);
1923 if (rc)
1924 goto out_unlock;
1925
1926 /* Check the validity of the new context. */
1927 if (!policydb_context_isvalid(&policydb, &newcon)) {
1928 rc = convert_context_handle_invalid_context(&newcon);
1929 if (rc)
1930 goto bad;
1931 }
1932
1933 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
1934 goto out_unlock;
1935
1936 bad:
1937 if (!context_struct_to_string(&newcon, &s, &len)) {
1938 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1939 "security_sid_mls_copy: invalid context %s", s);
1940 kfree(s);
1941 }
1942
1943 out_unlock:
1944 POLICY_RDUNLOCK;
1945 context_destroy(&newcon);
1946 out:
1947 return rc;
1948 }
1949
1950 struct selinux_audit_rule {
1951 u32 au_seqno;
1952 struct context au_ctxt;
1953 };
1954
1955 void selinux_audit_rule_free(struct selinux_audit_rule *rule)
1956 {
1957 if (rule) {
1958 context_destroy(&rule->au_ctxt);
1959 kfree(rule);
1960 }
1961 }
1962
1963 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
1964 struct selinux_audit_rule **rule)
1965 {
1966 struct selinux_audit_rule *tmprule;
1967 struct role_datum *roledatum;
1968 struct type_datum *typedatum;
1969 struct user_datum *userdatum;
1970 int rc = 0;
1971
1972 *rule = NULL;
1973
1974 if (!ss_initialized)
1975 return -ENOTSUPP;
1976
1977 switch (field) {
1978 case AUDIT_SUBJ_USER:
1979 case AUDIT_SUBJ_ROLE:
1980 case AUDIT_SUBJ_TYPE:
1981 case AUDIT_OBJ_USER:
1982 case AUDIT_OBJ_ROLE:
1983 case AUDIT_OBJ_TYPE:
1984 /* only 'equals' and 'not equals' fit user, role, and type */
1985 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
1986 return -EINVAL;
1987 break;
1988 case AUDIT_SUBJ_SEN:
1989 case AUDIT_SUBJ_CLR:
1990 case AUDIT_OBJ_LEV_LOW:
1991 case AUDIT_OBJ_LEV_HIGH:
1992 /* we do not allow a range, indicated by the presense of '-' */
1993 if (strchr(rulestr, '-'))
1994 return -EINVAL;
1995 break;
1996 default:
1997 /* only the above fields are valid */
1998 return -EINVAL;
1999 }
2000
2001 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2002 if (!tmprule)
2003 return -ENOMEM;
2004
2005 context_init(&tmprule->au_ctxt);
2006
2007 POLICY_RDLOCK;
2008
2009 tmprule->au_seqno = latest_granting;
2010
2011 switch (field) {
2012 case AUDIT_SUBJ_USER:
2013 case AUDIT_OBJ_USER:
2014 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2015 if (!userdatum)
2016 rc = -EINVAL;
2017 else
2018 tmprule->au_ctxt.user = userdatum->value;
2019 break;
2020 case AUDIT_SUBJ_ROLE:
2021 case AUDIT_OBJ_ROLE:
2022 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2023 if (!roledatum)
2024 rc = -EINVAL;
2025 else
2026 tmprule->au_ctxt.role = roledatum->value;
2027 break;
2028 case AUDIT_SUBJ_TYPE:
2029 case AUDIT_OBJ_TYPE:
2030 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2031 if (!typedatum)
2032 rc = -EINVAL;
2033 else
2034 tmprule->au_ctxt.type = typedatum->value;
2035 break;
2036 case AUDIT_SUBJ_SEN:
2037 case AUDIT_SUBJ_CLR:
2038 case AUDIT_OBJ_LEV_LOW:
2039 case AUDIT_OBJ_LEV_HIGH:
2040 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2041 break;
2042 }
2043
2044 POLICY_RDUNLOCK;
2045
2046 if (rc) {
2047 selinux_audit_rule_free(tmprule);
2048 tmprule = NULL;
2049 }
2050
2051 *rule = tmprule;
2052
2053 return rc;
2054 }
2055
2056 int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2057 struct selinux_audit_rule *rule,
2058 struct audit_context *actx)
2059 {
2060 struct context *ctxt;
2061 struct mls_level *level;
2062 int match = 0;
2063
2064 if (!rule) {
2065 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2066 "selinux_audit_rule_match: missing rule\n");
2067 return -ENOENT;
2068 }
2069
2070 POLICY_RDLOCK;
2071
2072 if (rule->au_seqno < latest_granting) {
2073 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2074 "selinux_audit_rule_match: stale rule\n");
2075 match = -ESTALE;
2076 goto out;
2077 }
2078
2079 ctxt = sidtab_search(&sidtab, sid);
2080 if (!ctxt) {
2081 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2082 "selinux_audit_rule_match: unrecognized SID %d\n",
2083 sid);
2084 match = -ENOENT;
2085 goto out;
2086 }
2087
2088 /* a field/op pair that is not caught here will simply fall through
2089 without a match */
2090 switch (field) {
2091 case AUDIT_SUBJ_USER:
2092 case AUDIT_OBJ_USER:
2093 switch (op) {
2094 case AUDIT_EQUAL:
2095 match = (ctxt->user == rule->au_ctxt.user);
2096 break;
2097 case AUDIT_NOT_EQUAL:
2098 match = (ctxt->user != rule->au_ctxt.user);
2099 break;
2100 }
2101 break;
2102 case AUDIT_SUBJ_ROLE:
2103 case AUDIT_OBJ_ROLE:
2104 switch (op) {
2105 case AUDIT_EQUAL:
2106 match = (ctxt->role == rule->au_ctxt.role);
2107 break;
2108 case AUDIT_NOT_EQUAL:
2109 match = (ctxt->role != rule->au_ctxt.role);
2110 break;
2111 }
2112 break;
2113 case AUDIT_SUBJ_TYPE:
2114 case AUDIT_OBJ_TYPE:
2115 switch (op) {
2116 case AUDIT_EQUAL:
2117 match = (ctxt->type == rule->au_ctxt.type);
2118 break;
2119 case AUDIT_NOT_EQUAL:
2120 match = (ctxt->type != rule->au_ctxt.type);
2121 break;
2122 }
2123 break;
2124 case AUDIT_SUBJ_SEN:
2125 case AUDIT_SUBJ_CLR:
2126 case AUDIT_OBJ_LEV_LOW:
2127 case AUDIT_OBJ_LEV_HIGH:
2128 level = ((field == AUDIT_SUBJ_SEN ||
2129 field == AUDIT_OBJ_LEV_LOW) ?
2130 &ctxt->range.level[0] : &ctxt->range.level[1]);
2131 switch (op) {
2132 case AUDIT_EQUAL:
2133 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2134 level);
2135 break;
2136 case AUDIT_NOT_EQUAL:
2137 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2138 level);
2139 break;
2140 case AUDIT_LESS_THAN:
2141 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2142 level) &&
2143 !mls_level_eq(&rule->au_ctxt.range.level[0],
2144 level));
2145 break;
2146 case AUDIT_LESS_THAN_OR_EQUAL:
2147 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2148 level);
2149 break;
2150 case AUDIT_GREATER_THAN:
2151 match = (mls_level_dom(level,
2152 &rule->au_ctxt.range.level[0]) &&
2153 !mls_level_eq(level,
2154 &rule->au_ctxt.range.level[0]));
2155 break;
2156 case AUDIT_GREATER_THAN_OR_EQUAL:
2157 match = mls_level_dom(level,
2158 &rule->au_ctxt.range.level[0]);
2159 break;
2160 }
2161 }
2162
2163 out:
2164 POLICY_RDUNLOCK;
2165 return match;
2166 }
2167
2168 static int (*aurule_callback)(void) = NULL;
2169
2170 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2171 u16 class, u32 perms, u32 *retained)
2172 {
2173 int err = 0;
2174
2175 if (event == AVC_CALLBACK_RESET && aurule_callback)
2176 err = aurule_callback();
2177 return err;
2178 }
2179
2180 static int __init aurule_init(void)
2181 {
2182 int err;
2183
2184 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2185 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2186 if (err)
2187 panic("avc_add_callback() failed, error %d\n", err);
2188
2189 return err;
2190 }
2191 __initcall(aurule_init);
2192
2193 void selinux_audit_set_callback(int (*callback)(void))
2194 {
2195 aurule_callback = callback;
2196 }
2197
2198 /**
2199 * security_skb_extlbl_sid - Determine the external label of a packet
2200 * @skb: the packet
2201 * @base_sid: the SELinux SID to use as a context for MLS only external labels
2202 * @sid: the packet's SID
2203 *
2204 * Description:
2205 * Check the various different forms of external packet labeling and determine
2206 * the external SID for the packet.
2207 *
2208 */
2209 void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid)
2210 {
2211 u32 xfrm_sid;
2212 u32 nlbl_sid;
2213
2214 selinux_skb_xfrm_sid(skb, &xfrm_sid);
2215 if (selinux_netlbl_skbuff_getsid(skb,
2216 (xfrm_sid == SECSID_NULL ?
2217 base_sid : xfrm_sid),
2218 &nlbl_sid) != 0)
2219 nlbl_sid = SECSID_NULL;
2220
2221 *sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
2222 }
2223
2224 #ifdef CONFIG_NETLABEL
2225 /*
2226 * This is the structure we store inside the NetLabel cache block.
2227 */
2228 #define NETLBL_CACHE(x) ((struct netlbl_cache *)(x))
2229 #define NETLBL_CACHE_T_NONE 0
2230 #define NETLBL_CACHE_T_SID 1
2231 #define NETLBL_CACHE_T_MLS 2
2232 struct netlbl_cache {
2233 u32 type;
2234 union {
2235 u32 sid;
2236 struct mls_range mls_label;
2237 } data;
2238 };
2239
2240 /**
2241 * selinux_netlbl_cache_free - Free the NetLabel cached data
2242 * @data: the data to free
2243 *
2244 * Description:
2245 * This function is intended to be used as the free() callback inside the
2246 * netlbl_lsm_cache structure.
2247 *
2248 */
2249 static void selinux_netlbl_cache_free(const void *data)
2250 {
2251 struct netlbl_cache *cache;
2252
2253 if (data == NULL)
2254 return;
2255
2256 cache = NETLBL_CACHE(data);
2257 switch (cache->type) {
2258 case NETLBL_CACHE_T_MLS:
2259 ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2260 break;
2261 }
2262 kfree(data);
2263 }
2264
2265 /**
2266 * selinux_netlbl_cache_add - Add an entry to the NetLabel cache
2267 * @skb: the packet
2268 * @ctx: the SELinux context
2269 *
2270 * Description:
2271 * Attempt to cache the context in @ctx, which was derived from the packet in
2272 * @skb, in the NetLabel subsystem cache.
2273 *
2274 */
2275 static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx)
2276 {
2277 struct netlbl_cache *cache = NULL;
2278 struct netlbl_lsm_secattr secattr;
2279
2280 netlbl_secattr_init(&secattr);
2281 secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2282 if (secattr.cache == NULL)
2283 goto netlbl_cache_add_return;
2284
2285 cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2286 if (cache == NULL)
2287 goto netlbl_cache_add_return;
2288
2289 cache->type = NETLBL_CACHE_T_MLS;
2290 if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2291 &ctx->range.level[0].cat) != 0)
2292 goto netlbl_cache_add_return;
2293 cache->data.mls_label.level[1].cat.highbit =
2294 cache->data.mls_label.level[0].cat.highbit;
2295 cache->data.mls_label.level[1].cat.node =
2296 cache->data.mls_label.level[0].cat.node;
2297 cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2298 cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2299
2300 secattr.cache->free = selinux_netlbl_cache_free;
2301 secattr.cache->data = (void *)cache;
2302 secattr.flags = NETLBL_SECATTR_CACHE;
2303
2304 netlbl_cache_add(skb, &secattr);
2305
2306 netlbl_cache_add_return:
2307 netlbl_secattr_destroy(&secattr);
2308 }
2309
2310 /**
2311 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
2312 *
2313 * Description:
2314 * Invalidate the NetLabel security attribute mapping cache.
2315 *
2316 */
2317 void selinux_netlbl_cache_invalidate(void)
2318 {
2319 netlbl_cache_invalidate();
2320 }
2321
2322 /**
2323 * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2324 * @skb: the network packet
2325 * @secattr: the NetLabel packet security attributes
2326 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2327 * @sid: the SELinux SID
2328 *
2329 * Description:
2330 * Convert the given NetLabel packet security attributes in @secattr into a
2331 * SELinux SID. If the @secattr field does not contain a full SELinux
2332 * SID/context then use the context in @base_sid as the foundation. If @skb
2333 * is not NULL attempt to cache as much data as possibile. Returns zero on
2334 * success, negative values on failure.
2335 *
2336 */
2337 static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
2338 struct netlbl_lsm_secattr *secattr,
2339 u32 base_sid,
2340 u32 *sid)
2341 {
2342 int rc = -EIDRM;
2343 struct context *ctx;
2344 struct context ctx_new;
2345 struct netlbl_cache *cache;
2346
2347 POLICY_RDLOCK;
2348
2349 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2350 cache = NETLBL_CACHE(secattr->cache->data);
2351 switch (cache->type) {
2352 case NETLBL_CACHE_T_SID:
2353 *sid = cache->data.sid;
2354 rc = 0;
2355 break;
2356 case NETLBL_CACHE_T_MLS:
2357 ctx = sidtab_search(&sidtab, base_sid);
2358 if (ctx == NULL)
2359 goto netlbl_secattr_to_sid_return;
2360
2361 ctx_new.user = ctx->user;
2362 ctx_new.role = ctx->role;
2363 ctx_new.type = ctx->type;
2364 ctx_new.range.level[0].sens =
2365 cache->data.mls_label.level[0].sens;
2366 ctx_new.range.level[0].cat.highbit =
2367 cache->data.mls_label.level[0].cat.highbit;
2368 ctx_new.range.level[0].cat.node =
2369 cache->data.mls_label.level[0].cat.node;
2370 ctx_new.range.level[1].sens =
2371 cache->data.mls_label.level[1].sens;
2372 ctx_new.range.level[1].cat.highbit =
2373 cache->data.mls_label.level[1].cat.highbit;
2374 ctx_new.range.level[1].cat.node =
2375 cache->data.mls_label.level[1].cat.node;
2376
2377 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2378 break;
2379 default:
2380 goto netlbl_secattr_to_sid_return;
2381 }
2382 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2383 ctx = sidtab_search(&sidtab, base_sid);
2384 if (ctx == NULL)
2385 goto netlbl_secattr_to_sid_return;
2386
2387 ctx_new.user = ctx->user;
2388 ctx_new.role = ctx->role;
2389 ctx_new.type = ctx->type;
2390 mls_import_netlbl_lvl(&ctx_new, secattr);
2391 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2392 if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2393 secattr->mls_cat) != 0)
2394 goto netlbl_secattr_to_sid_return;
2395 ctx_new.range.level[1].cat.highbit =
2396 ctx_new.range.level[0].cat.highbit;
2397 ctx_new.range.level[1].cat.node =
2398 ctx_new.range.level[0].cat.node;
2399 } else {
2400 ebitmap_init(&ctx_new.range.level[0].cat);
2401 ebitmap_init(&ctx_new.range.level[1].cat);
2402 }
2403 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2404 goto netlbl_secattr_to_sid_return_cleanup;
2405
2406 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2407 if (rc != 0)
2408 goto netlbl_secattr_to_sid_return_cleanup;
2409
2410 if (skb != NULL)
2411 selinux_netlbl_cache_add(skb, &ctx_new);
2412 ebitmap_destroy(&ctx_new.range.level[0].cat);
2413 } else {
2414 *sid = SECSID_NULL;
2415 rc = 0;
2416 }
2417
2418 netlbl_secattr_to_sid_return:
2419 POLICY_RDUNLOCK;
2420 return rc;
2421 netlbl_secattr_to_sid_return_cleanup:
2422 ebitmap_destroy(&ctx_new.range.level[0].cat);
2423 goto netlbl_secattr_to_sid_return;
2424 }
2425
2426 /**
2427 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
2428 * @skb: the packet
2429 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2430 * @sid: the SID
2431 *
2432 * Description:
2433 * Call the NetLabel mechanism to get the security attributes of the given
2434 * packet and use those attributes to determine the correct context/SID to
2435 * assign to the packet. Returns zero on success, negative values on failure.
2436 *
2437 */
2438 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
2439 {
2440 int rc;
2441 struct netlbl_lsm_secattr secattr;
2442
2443 netlbl_secattr_init(&secattr);
2444 rc = netlbl_skbuff_getattr(skb, &secattr);
2445 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2446 rc = selinux_netlbl_secattr_to_sid(skb,
2447 &secattr,
2448 base_sid,
2449 sid);
2450 else
2451 *sid = SECSID_NULL;
2452 netlbl_secattr_destroy(&secattr);
2453
2454 return rc;
2455 }
2456
2457 /**
2458 * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism
2459 * @sock: the socket to label
2460 * @sid: the SID to use
2461 *
2462 * Description:
2463 * Attempt to label a socket using the NetLabel mechanism using the given
2464 * SID. Returns zero values on success, negative values on failure. The
2465 * caller is responsibile for calling rcu_read_lock() before calling this
2466 * this function and rcu_read_unlock() after this function returns.
2467 *
2468 */
2469 static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
2470 {
2471 int rc = -ENOENT;
2472 struct sk_security_struct *sksec = sock->sk->sk_security;
2473 struct netlbl_lsm_secattr secattr;
2474 struct context *ctx;
2475
2476 if (!ss_initialized)
2477 return 0;
2478
2479 netlbl_secattr_init(&secattr);
2480
2481 POLICY_RDLOCK;
2482
2483 ctx = sidtab_search(&sidtab, sid);
2484 if (ctx == NULL)
2485 goto netlbl_socket_setsid_return;
2486
2487 secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2488 GFP_ATOMIC);
2489 secattr.flags |= NETLBL_SECATTR_DOMAIN;
2490 mls_export_netlbl_lvl(ctx, &secattr);
2491 rc = mls_export_netlbl_cat(ctx, &secattr);
2492 if (rc != 0)
2493 goto netlbl_socket_setsid_return;
2494
2495 rc = netlbl_socket_setattr(sock, &secattr);
2496 if (rc == 0) {
2497 spin_lock_bh(&sksec->nlbl_lock);
2498 sksec->nlbl_state = NLBL_LABELED;
2499 spin_unlock_bh(&sksec->nlbl_lock);
2500 }
2501
2502 netlbl_socket_setsid_return:
2503 POLICY_RDUNLOCK;
2504 netlbl_secattr_destroy(&secattr);
2505 return rc;
2506 }
2507
2508 /**
2509 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
2510 * @ssec: the sk_security_struct
2511 * @family: the socket family
2512 *
2513 * Description:
2514 * Called when the NetLabel state of a sk_security_struct needs to be reset.
2515 * The caller is responsibile for all the NetLabel sk_security_struct locking.
2516 *
2517 */
2518 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
2519 int family)
2520 {
2521 if (family == PF_INET)
2522 ssec->nlbl_state = NLBL_REQUIRE;
2523 else
2524 ssec->nlbl_state = NLBL_UNSET;
2525 }
2526
2527 /**
2528 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
2529 * @ssec: the sk_security_struct
2530 * @family: the socket family
2531 *
2532 * Description:
2533 * Called when a new sk_security_struct is allocated to initialize the NetLabel
2534 * fields.
2535 *
2536 */
2537 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
2538 int family)
2539 {
2540 /* No locking needed, we are the only one who has access to ssec */
2541 selinux_netlbl_sk_security_reset(ssec, family);
2542 spin_lock_init(&ssec->nlbl_lock);
2543 }
2544
2545 /**
2546 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
2547 * @ssec: the original sk_security_struct
2548 * @newssec: the cloned sk_security_struct
2549 *
2550 * Description:
2551 * Clone the NetLabel specific sk_security_struct fields from @ssec to
2552 * @newssec.
2553 *
2554 */
2555 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
2556 struct sk_security_struct *newssec)
2557 {
2558 /* We don't need to take newssec->nlbl_lock because we are the only
2559 * thread with access to newssec, but we do need to take the RCU read
2560 * lock as other threads could have access to ssec */
2561 rcu_read_lock();
2562 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
2563 newssec->sclass = ssec->sclass;
2564 rcu_read_unlock();
2565 }
2566
2567 /**
2568 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
2569 * @sock: the socket to label
2570 *
2571 * Description:
2572 * Attempt to label a socket using the NetLabel mechanism using the given
2573 * SID. Returns zero values on success, negative values on failure.
2574 *
2575 */
2576 int selinux_netlbl_socket_post_create(struct socket *sock)
2577 {
2578 int rc = 0;
2579 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2580 struct sk_security_struct *sksec = sock->sk->sk_security;
2581
2582 sksec->sclass = isec->sclass;
2583
2584 rcu_read_lock();
2585 if (sksec->nlbl_state == NLBL_REQUIRE)
2586 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2587 rcu_read_unlock();
2588
2589 return rc;
2590 }
2591
2592 /**
2593 * selinux_netlbl_sock_graft - Netlabel the new socket
2594 * @sk: the new connection
2595 * @sock: the new socket
2596 *
2597 * Description:
2598 * The connection represented by @sk is being grafted onto @sock so set the
2599 * socket's NetLabel to match the SID of @sk.
2600 *
2601 */
2602 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
2603 {
2604 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2605 struct sk_security_struct *sksec = sk->sk_security;
2606 struct netlbl_lsm_secattr secattr;
2607 u32 nlbl_peer_sid;
2608
2609 sksec->sclass = isec->sclass;
2610
2611 rcu_read_lock();
2612
2613 if (sksec->nlbl_state != NLBL_REQUIRE) {
2614 rcu_read_unlock();
2615 return;
2616 }
2617
2618 netlbl_secattr_init(&secattr);
2619 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
2620 secattr.flags != NETLBL_SECATTR_NONE &&
2621 selinux_netlbl_secattr_to_sid(NULL,
2622 &secattr,
2623 SECINITSID_UNLABELED,
2624 &nlbl_peer_sid) == 0)
2625 sksec->peer_sid = nlbl_peer_sid;
2626 netlbl_secattr_destroy(&secattr);
2627
2628 /* Try to set the NetLabel on the socket to save time later, if we fail
2629 * here we will pick up the pieces in later calls to
2630 * selinux_netlbl_inode_permission(). */
2631 selinux_netlbl_socket_setsid(sock, sksec->sid);
2632
2633 rcu_read_unlock();
2634 }
2635
2636 /**
2637 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
2638 * @inode: the file descriptor's inode
2639 * @mask: the permission mask
2640 *
2641 * Description:
2642 * Looks at a file's inode and if it is marked as a socket protected by
2643 * NetLabel then verify that the socket has been labeled, if not try to label
2644 * the socket now with the inode's SID. Returns zero on success, negative
2645 * values on failure.
2646 *
2647 */
2648 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
2649 {
2650 int rc;
2651 struct sk_security_struct *sksec;
2652 struct socket *sock;
2653
2654 if (!S_ISSOCK(inode->i_mode) ||
2655 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
2656 return 0;
2657 sock = SOCKET_I(inode);
2658 sksec = sock->sk->sk_security;
2659
2660 rcu_read_lock();
2661 if (sksec->nlbl_state != NLBL_REQUIRE) {
2662 rcu_read_unlock();
2663 return 0;
2664 }
2665 local_bh_disable();
2666 bh_lock_sock_nested(sock->sk);
2667 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2668 bh_unlock_sock(sock->sk);
2669 local_bh_enable();
2670 rcu_read_unlock();
2671
2672 return rc;
2673 }
2674
2675 /**
2676 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
2677 * @sksec: the sock's sk_security_struct
2678 * @skb: the packet
2679 * @ad: the audit data
2680 *
2681 * Description:
2682 * Fetch the NetLabel security attributes from @skb and perform an access check
2683 * against the receiving socket. Returns zero on success, negative values on
2684 * error.
2685 *
2686 */
2687 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
2688 struct sk_buff *skb,
2689 struct avc_audit_data *ad)
2690 {
2691 int rc;
2692 u32 netlbl_sid;
2693 u32 recv_perm;
2694
2695 rc = selinux_netlbl_skbuff_getsid(skb,
2696 SECINITSID_UNLABELED,
2697 &netlbl_sid);
2698 if (rc != 0)
2699 return rc;
2700
2701 if (netlbl_sid == SECSID_NULL)
2702 return 0;
2703
2704 switch (sksec->sclass) {
2705 case SECCLASS_UDP_SOCKET:
2706 recv_perm = UDP_SOCKET__RECVFROM;
2707 break;
2708 case SECCLASS_TCP_SOCKET:
2709 recv_perm = TCP_SOCKET__RECVFROM;
2710 break;
2711 default:
2712 recv_perm = RAWIP_SOCKET__RECVFROM;
2713 }
2714
2715 rc = avc_has_perm(sksec->sid,
2716 netlbl_sid,
2717 sksec->sclass,
2718 recv_perm,
2719 ad);
2720 if (rc == 0)
2721 return 0;
2722
2723 netlbl_skbuff_err(skb, rc);
2724 return rc;
2725 }
2726
2727 /**
2728 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
2729 * @sock: the socket
2730 * @level: the socket level or protocol
2731 * @optname: the socket option name
2732 *
2733 * Description:
2734 * Check the setsockopt() call and if the user is trying to replace the IP
2735 * options on a socket and a NetLabel is in place for the socket deny the
2736 * access; otherwise allow the access. Returns zero when the access is
2737 * allowed, -EACCES when denied, and other negative values on error.
2738 *
2739 */
2740 int selinux_netlbl_socket_setsockopt(struct socket *sock,
2741 int level,
2742 int optname)
2743 {
2744 int rc = 0;
2745 struct sk_security_struct *sksec = sock->sk->sk_security;
2746 struct netlbl_lsm_secattr secattr;
2747
2748 rcu_read_lock();
2749 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
2750 sksec->nlbl_state == NLBL_LABELED) {
2751 netlbl_secattr_init(&secattr);
2752 rc = netlbl_socket_getattr(sock, &secattr);
2753 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2754 rc = -EACCES;
2755 netlbl_secattr_destroy(&secattr);
2756 }
2757 rcu_read_unlock();
2758
2759 return rc;
2760 }
2761 #endif /* CONFIG_NETLABEL */
kernel-based virtual machine