?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
sync hh.org
[hh.org.git] / security / selinux / ss / services.c
blobbdb7070dd3dc3d7477429e946283071625e70bd6
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 return 0;
1303 }
1304
1305 #if 0
1306 sidtab_hash_eval(&sidtab, "sids");
1307 #endif
1308
1309 if (policydb_read(&newpolicydb, fp)) {
1310 LOAD_UNLOCK;
1311 return -EINVAL;
1312 }
1313
1314 sidtab_init(&newsidtab);
1315
1316 /* Verify that the kernel defined classes are correct. */
1317 if (validate_classes(&newpolicydb)) {
1318 printk(KERN_ERR
1319 "security: the definition of a class is incorrect\n");
1320 rc = -EINVAL;
1321 goto err;
1322 }
1323
1324 /* Clone the SID table. */
1325 sidtab_shutdown(&sidtab);
1326 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1327 rc = -ENOMEM;
1328 goto err;
1329 }
1330
1331 /* Convert the internal representations of contexts
1332 in the new SID table and remove invalid SIDs. */
1333 args.oldp = &policydb;
1334 args.newp = &newpolicydb;
1335 sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1336
1337 /* Save the old policydb and SID table to free later. */
1338 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1339 sidtab_set(&oldsidtab, &sidtab);
1340
1341 /* Install the new policydb and SID table. */
1342 POLICY_WRLOCK;
1343 memcpy(&policydb, &newpolicydb, sizeof policydb);
1344 sidtab_set(&sidtab, &newsidtab);
1345 seqno = ++latest_granting;
1346 policydb_loaded_version = policydb.policyvers;
1347 POLICY_WRUNLOCK;
1348 LOAD_UNLOCK;
1349
1350 /* Free the old policydb and SID table. */
1351 policydb_destroy(&oldpolicydb);
1352 sidtab_destroy(&oldsidtab);
1353
1354 avc_ss_reset(seqno);
1355 selnl_notify_policyload(seqno);
1356 selinux_netlbl_cache_invalidate();
1357
1358 return 0;
1359
1360 err:
1361 LOAD_UNLOCK;
1362 sidtab_destroy(&newsidtab);
1363 policydb_destroy(&newpolicydb);
1364 return rc;
1365
1366 }
1367
1368 /**
1369 * security_port_sid - Obtain the SID for a port.
1370 * @domain: communication domain aka address family
1371 * @type: socket type
1372 * @protocol: protocol number
1373 * @port: port number
1374 * @out_sid: security identifier
1375 */
1376 int security_port_sid(u16 domain,
1377 u16 type,
1378 u8 protocol,
1379 u16 port,
1380 u32 *out_sid)
1381 {
1382 struct ocontext *c;
1383 int rc = 0;
1384
1385 POLICY_RDLOCK;
1386
1387 c = policydb.ocontexts[OCON_PORT];
1388 while (c) {
1389 if (c->u.port.protocol == protocol &&
1390 c->u.port.low_port <= port &&
1391 c->u.port.high_port >= port)
1392 break;
1393 c = c->next;
1394 }
1395
1396 if (c) {
1397 if (!c->sid[0]) {
1398 rc = sidtab_context_to_sid(&sidtab,
1399 &c->context[0],
1400 &c->sid[0]);
1401 if (rc)
1402 goto out;
1403 }
1404 *out_sid = c->sid[0];
1405 } else {
1406 *out_sid = SECINITSID_PORT;
1407 }
1408
1409 out:
1410 POLICY_RDUNLOCK;
1411 return rc;
1412 }
1413
1414 /**
1415 * security_netif_sid - Obtain the SID for a network interface.
1416 * @name: interface name
1417 * @if_sid: interface SID
1418 * @msg_sid: default SID for received packets
1419 */
1420 int security_netif_sid(char *name,
1421 u32 *if_sid,
1422 u32 *msg_sid)
1423 {
1424 int rc = 0;
1425 struct ocontext *c;
1426
1427 POLICY_RDLOCK;
1428
1429 c = policydb.ocontexts[OCON_NETIF];
1430 while (c) {
1431 if (strcmp(name, c->u.name) == 0)
1432 break;
1433 c = c->next;
1434 }
1435
1436 if (c) {
1437 if (!c->sid[0] || !c->sid[1]) {
1438 rc = sidtab_context_to_sid(&sidtab,
1439 &c->context[0],
1440 &c->sid[0]);
1441 if (rc)
1442 goto out;
1443 rc = sidtab_context_to_sid(&sidtab,
1444 &c->context[1],
1445 &c->sid[1]);
1446 if (rc)
1447 goto out;
1448 }
1449 *if_sid = c->sid[0];
1450 *msg_sid = c->sid[1];
1451 } else {
1452 *if_sid = SECINITSID_NETIF;
1453 *msg_sid = SECINITSID_NETMSG;
1454 }
1455
1456 out:
1457 POLICY_RDUNLOCK;
1458 return rc;
1459 }
1460
1461 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1462 {
1463 int i, fail = 0;
1464
1465 for(i = 0; i < 4; i++)
1466 if(addr[i] != (input[i] & mask[i])) {
1467 fail = 1;
1468 break;
1469 }
1470
1471 return !fail;
1472 }
1473
1474 /**
1475 * security_node_sid - Obtain the SID for a node (host).
1476 * @domain: communication domain aka address family
1477 * @addrp: address
1478 * @addrlen: address length in bytes
1479 * @out_sid: security identifier
1480 */
1481 int security_node_sid(u16 domain,
1482 void *addrp,
1483 u32 addrlen,
1484 u32 *out_sid)
1485 {
1486 int rc = 0;
1487 struct ocontext *c;
1488
1489 POLICY_RDLOCK;
1490
1491 switch (domain) {
1492 case AF_INET: {
1493 u32 addr;
1494
1495 if (addrlen != sizeof(u32)) {
1496 rc = -EINVAL;
1497 goto out;
1498 }
1499
1500 addr = *((u32 *)addrp);
1501
1502 c = policydb.ocontexts[OCON_NODE];
1503 while (c) {
1504 if (c->u.node.addr == (addr & c->u.node.mask))
1505 break;
1506 c = c->next;
1507 }
1508 break;
1509 }
1510
1511 case AF_INET6:
1512 if (addrlen != sizeof(u64) * 2) {
1513 rc = -EINVAL;
1514 goto out;
1515 }
1516 c = policydb.ocontexts[OCON_NODE6];
1517 while (c) {
1518 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1519 c->u.node6.mask))
1520 break;
1521 c = c->next;
1522 }
1523 break;
1524
1525 default:
1526 *out_sid = SECINITSID_NODE;
1527 goto out;
1528 }
1529
1530 if (c) {
1531 if (!c->sid[0]) {
1532 rc = sidtab_context_to_sid(&sidtab,
1533 &c->context[0],
1534 &c->sid[0]);
1535 if (rc)
1536 goto out;
1537 }
1538 *out_sid = c->sid[0];
1539 } else {
1540 *out_sid = SECINITSID_NODE;
1541 }
1542
1543 out:
1544 POLICY_RDUNLOCK;
1545 return rc;
1546 }
1547
1548 #define SIDS_NEL 25
1549
1550 /**
1551 * security_get_user_sids - Obtain reachable SIDs for a user.
1552 * @fromsid: starting SID
1553 * @username: username
1554 * @sids: array of reachable SIDs for user
1555 * @nel: number of elements in @sids
1556 *
1557 * Generate the set of SIDs for legal security contexts
1558 * for a given user that can be reached by @fromsid.
1559 * Set *@sids to point to a dynamically allocated
1560 * array containing the set of SIDs. Set *@nel to the
1561 * number of elements in the array.
1562 */
1563
1564 int security_get_user_sids(u32 fromsid,
1565 char *username,
1566 u32 **sids,
1567 u32 *nel)
1568 {
1569 struct context *fromcon, usercon;
1570 u32 *mysids, *mysids2, sid;
1571 u32 mynel = 0, maxnel = SIDS_NEL;
1572 struct user_datum *user;
1573 struct role_datum *role;
1574 struct av_decision avd;
1575 struct ebitmap_node *rnode, *tnode;
1576 int rc = 0, i, j;
1577
1578 if (!ss_initialized) {
1579 *sids = NULL;
1580 *nel = 0;
1581 goto out;
1582 }
1583
1584 POLICY_RDLOCK;
1585
1586 fromcon = sidtab_search(&sidtab, fromsid);
1587 if (!fromcon) {
1588 rc = -EINVAL;
1589 goto out_unlock;
1590 }
1591
1592 user = hashtab_search(policydb.p_users.table, username);
1593 if (!user) {
1594 rc = -EINVAL;
1595 goto out_unlock;
1596 }
1597 usercon.user = user->value;
1598
1599 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1600 if (!mysids) {
1601 rc = -ENOMEM;
1602 goto out_unlock;
1603 }
1604
1605 ebitmap_for_each_bit(&user->roles, rnode, i) {
1606 if (!ebitmap_node_get_bit(rnode, i))
1607 continue;
1608 role = policydb.role_val_to_struct[i];
1609 usercon.role = i+1;
1610 ebitmap_for_each_bit(&role->types, tnode, j) {
1611 if (!ebitmap_node_get_bit(tnode, j))
1612 continue;
1613 usercon.type = j+1;
1614
1615 if (mls_setup_user_range(fromcon, user, &usercon))
1616 continue;
1617
1618 rc = context_struct_compute_av(fromcon, &usercon,
1619 SECCLASS_PROCESS,
1620 PROCESS__TRANSITION,
1621 &avd);
1622 if (rc || !(avd.allowed & PROCESS__TRANSITION))
1623 continue;
1624 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1625 if (rc) {
1626 kfree(mysids);
1627 goto out_unlock;
1628 }
1629 if (mynel < maxnel) {
1630 mysids[mynel++] = sid;
1631 } else {
1632 maxnel += SIDS_NEL;
1633 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1634 if (!mysids2) {
1635 rc = -ENOMEM;
1636 kfree(mysids);
1637 goto out_unlock;
1638 }
1639 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1640 kfree(mysids);
1641 mysids = mysids2;
1642 mysids[mynel++] = sid;
1643 }
1644 }
1645 }
1646
1647 *sids = mysids;
1648 *nel = mynel;
1649
1650 out_unlock:
1651 POLICY_RDUNLOCK;
1652 out:
1653 return rc;
1654 }
1655
1656 /**
1657 * security_genfs_sid - Obtain a SID for a file in a filesystem
1658 * @fstype: filesystem type
1659 * @path: path from root of mount
1660 * @sclass: file security class
1661 * @sid: SID for path
1662 *
1663 * Obtain a SID to use for a file in a filesystem that
1664 * cannot support xattr or use a fixed labeling behavior like
1665 * transition SIDs or task SIDs.
1666 */
1667 int security_genfs_sid(const char *fstype,
1668 char *path,
1669 u16 sclass,
1670 u32 *sid)
1671 {
1672 int len;
1673 struct genfs *genfs;
1674 struct ocontext *c;
1675 int rc = 0, cmp = 0;
1676
1677 POLICY_RDLOCK;
1678
1679 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1680 cmp = strcmp(fstype, genfs->fstype);
1681 if (cmp <= 0)
1682 break;
1683 }
1684
1685 if (!genfs || cmp) {
1686 *sid = SECINITSID_UNLABELED;
1687 rc = -ENOENT;
1688 goto out;
1689 }
1690
1691 for (c = genfs->head; c; c = c->next) {
1692 len = strlen(c->u.name);
1693 if ((!c->v.sclass || sclass == c->v.sclass) &&
1694 (strncmp(c->u.name, path, len) == 0))
1695 break;
1696 }
1697
1698 if (!c) {
1699 *sid = SECINITSID_UNLABELED;
1700 rc = -ENOENT;
1701 goto out;
1702 }
1703
1704 if (!c->sid[0]) {
1705 rc = sidtab_context_to_sid(&sidtab,
1706 &c->context[0],
1707 &c->sid[0]);
1708 if (rc)
1709 goto out;
1710 }
1711
1712 *sid = c->sid[0];
1713 out:
1714 POLICY_RDUNLOCK;
1715 return rc;
1716 }
1717
1718 /**
1719 * security_fs_use - Determine how to handle labeling for a filesystem.
1720 * @fstype: filesystem type
1721 * @behavior: labeling behavior
1722 * @sid: SID for filesystem (superblock)
1723 */
1724 int security_fs_use(
1725 const char *fstype,
1726 unsigned int *behavior,
1727 u32 *sid)
1728 {
1729 int rc = 0;
1730 struct ocontext *c;
1731
1732 POLICY_RDLOCK;
1733
1734 c = policydb.ocontexts[OCON_FSUSE];
1735 while (c) {
1736 if (strcmp(fstype, c->u.name) == 0)
1737 break;
1738 c = c->next;
1739 }
1740
1741 if (c) {
1742 *behavior = c->v.behavior;
1743 if (!c->sid[0]) {
1744 rc = sidtab_context_to_sid(&sidtab,
1745 &c->context[0],
1746 &c->sid[0]);
1747 if (rc)
1748 goto out;
1749 }
1750 *sid = c->sid[0];
1751 } else {
1752 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1753 if (rc) {
1754 *behavior = SECURITY_FS_USE_NONE;
1755 rc = 0;
1756 } else {
1757 *behavior = SECURITY_FS_USE_GENFS;
1758 }
1759 }
1760
1761 out:
1762 POLICY_RDUNLOCK;
1763 return rc;
1764 }
1765
1766 int security_get_bools(int *len, char ***names, int **values)
1767 {
1768 int i, rc = -ENOMEM;
1769
1770 POLICY_RDLOCK;
1771 *names = NULL;
1772 *values = NULL;
1773
1774 *len = policydb.p_bools.nprim;
1775 if (!*len) {
1776 rc = 0;
1777 goto out;
1778 }
1779
1780 *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1781 if (!*names)
1782 goto err;
1783
1784 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1785 if (!*values)
1786 goto err;
1787
1788 for (i = 0; i < *len; i++) {
1789 size_t name_len;
1790 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1791 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1792 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1793 if (!(*names)[i])
1794 goto err;
1795 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1796 (*names)[i][name_len - 1] = 0;
1797 }
1798 rc = 0;
1799 out:
1800 POLICY_RDUNLOCK;
1801 return rc;
1802 err:
1803 if (*names) {
1804 for (i = 0; i < *len; i++)
1805 kfree((*names)[i]);
1806 }
1807 kfree(*values);
1808 goto out;
1809 }
1810
1811
1812 int security_set_bools(int len, int *values)
1813 {
1814 int i, rc = 0;
1815 int lenp, seqno = 0;
1816 struct cond_node *cur;
1817
1818 POLICY_WRLOCK;
1819
1820 lenp = policydb.p_bools.nprim;
1821 if (len != lenp) {
1822 rc = -EFAULT;
1823 goto out;
1824 }
1825
1826 for (i = 0; i < len; i++) {
1827 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1828 audit_log(current->audit_context, GFP_ATOMIC,
1829 AUDIT_MAC_CONFIG_CHANGE,
1830 "bool=%s val=%d old_val=%d auid=%u",
1831 policydb.p_bool_val_to_name[i],
1832 !!values[i],
1833 policydb.bool_val_to_struct[i]->state,
1834 audit_get_loginuid(current->audit_context));
1835 }
1836 if (values[i]) {
1837 policydb.bool_val_to_struct[i]->state = 1;
1838 } else {
1839 policydb.bool_val_to_struct[i]->state = 0;
1840 }
1841 }
1842
1843 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1844 rc = evaluate_cond_node(&policydb, cur);
1845 if (rc)
1846 goto out;
1847 }
1848
1849 seqno = ++latest_granting;
1850
1851 out:
1852 POLICY_WRUNLOCK;
1853 if (!rc) {
1854 avc_ss_reset(seqno);
1855 selnl_notify_policyload(seqno);
1856 }
1857 return rc;
1858 }
1859
1860 int security_get_bool_value(int bool)
1861 {
1862 int rc = 0;
1863 int len;
1864
1865 POLICY_RDLOCK;
1866
1867 len = policydb.p_bools.nprim;
1868 if (bool >= len) {
1869 rc = -EFAULT;
1870 goto out;
1871 }
1872
1873 rc = policydb.bool_val_to_struct[bool]->state;
1874 out:
1875 POLICY_RDUNLOCK;
1876 return rc;
1877 }
1878
1879 /*
1880 * security_sid_mls_copy() - computes a new sid based on the given
1881 * sid and the mls portion of mls_sid.
1882 */
1883 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1884 {
1885 struct context *context1;
1886 struct context *context2;
1887 struct context newcon;
1888 char *s;
1889 u32 len;
1890 int rc = 0;
1891
1892 if (!ss_initialized || !selinux_mls_enabled) {
1893 *new_sid = sid;
1894 goto out;
1895 }
1896
1897 context_init(&newcon);
1898
1899 POLICY_RDLOCK;
1900 context1 = sidtab_search(&sidtab, sid);
1901 if (!context1) {
1902 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1903 "%d\n", sid);
1904 rc = -EINVAL;
1905 goto out_unlock;
1906 }
1907
1908 context2 = sidtab_search(&sidtab, mls_sid);
1909 if (!context2) {
1910 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1911 "%d\n", mls_sid);
1912 rc = -EINVAL;
1913 goto out_unlock;
1914 }
1915
1916 newcon.user = context1->user;
1917 newcon.role = context1->role;
1918 newcon.type = context1->type;
1919 rc = mls_copy_context(&newcon, context2);
1920 if (rc)
1921 goto out_unlock;
1922
1923
1924 /* Check the validity of the new context. */
1925 if (!policydb_context_isvalid(&policydb, &newcon)) {
1926 rc = convert_context_handle_invalid_context(&newcon);
1927 if (rc)
1928 goto bad;
1929 }
1930
1931 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
1932 goto out_unlock;
1933
1934 bad:
1935 if (!context_struct_to_string(&newcon, &s, &len)) {
1936 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1937 "security_sid_mls_copy: invalid context %s", s);
1938 kfree(s);
1939 }
1940
1941 out_unlock:
1942 POLICY_RDUNLOCK;
1943 context_destroy(&newcon);
1944 out:
1945 return rc;
1946 }
1947
1948 struct selinux_audit_rule {
1949 u32 au_seqno;
1950 struct context au_ctxt;
1951 };
1952
1953 void selinux_audit_rule_free(struct selinux_audit_rule *rule)
1954 {
1955 if (rule) {
1956 context_destroy(&rule->au_ctxt);
1957 kfree(rule);
1958 }
1959 }
1960
1961 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
1962 struct selinux_audit_rule **rule)
1963 {
1964 struct selinux_audit_rule *tmprule;
1965 struct role_datum *roledatum;
1966 struct type_datum *typedatum;
1967 struct user_datum *userdatum;
1968 int rc = 0;
1969
1970 *rule = NULL;
1971
1972 if (!ss_initialized)
1973 return -ENOTSUPP;
1974
1975 switch (field) {
1976 case AUDIT_SUBJ_USER:
1977 case AUDIT_SUBJ_ROLE:
1978 case AUDIT_SUBJ_TYPE:
1979 case AUDIT_OBJ_USER:
1980 case AUDIT_OBJ_ROLE:
1981 case AUDIT_OBJ_TYPE:
1982 /* only 'equals' and 'not equals' fit user, role, and type */
1983 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
1984 return -EINVAL;
1985 break;
1986 case AUDIT_SUBJ_SEN:
1987 case AUDIT_SUBJ_CLR:
1988 case AUDIT_OBJ_LEV_LOW:
1989 case AUDIT_OBJ_LEV_HIGH:
1990 /* we do not allow a range, indicated by the presense of '-' */
1991 if (strchr(rulestr, '-'))
1992 return -EINVAL;
1993 break;
1994 default:
1995 /* only the above fields are valid */
1996 return -EINVAL;
1997 }
1998
1999 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2000 if (!tmprule)
2001 return -ENOMEM;
2002
2003 context_init(&tmprule->au_ctxt);
2004
2005 POLICY_RDLOCK;
2006
2007 tmprule->au_seqno = latest_granting;
2008
2009 switch (field) {
2010 case AUDIT_SUBJ_USER:
2011 case AUDIT_OBJ_USER:
2012 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2013 if (!userdatum)
2014 rc = -EINVAL;
2015 else
2016 tmprule->au_ctxt.user = userdatum->value;
2017 break;
2018 case AUDIT_SUBJ_ROLE:
2019 case AUDIT_OBJ_ROLE:
2020 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2021 if (!roledatum)
2022 rc = -EINVAL;
2023 else
2024 tmprule->au_ctxt.role = roledatum->value;
2025 break;
2026 case AUDIT_SUBJ_TYPE:
2027 case AUDIT_OBJ_TYPE:
2028 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2029 if (!typedatum)
2030 rc = -EINVAL;
2031 else
2032 tmprule->au_ctxt.type = typedatum->value;
2033 break;
2034 case AUDIT_SUBJ_SEN:
2035 case AUDIT_SUBJ_CLR:
2036 case AUDIT_OBJ_LEV_LOW:
2037 case AUDIT_OBJ_LEV_HIGH:
2038 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2039 break;
2040 }
2041
2042 POLICY_RDUNLOCK;
2043
2044 if (rc) {
2045 selinux_audit_rule_free(tmprule);
2046 tmprule = NULL;
2047 }
2048
2049 *rule = tmprule;
2050
2051 return rc;
2052 }
2053
2054 int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2055 struct selinux_audit_rule *rule,
2056 struct audit_context *actx)
2057 {
2058 struct context *ctxt;
2059 struct mls_level *level;
2060 int match = 0;
2061
2062 if (!rule) {
2063 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2064 "selinux_audit_rule_match: missing rule\n");
2065 return -ENOENT;
2066 }
2067
2068 POLICY_RDLOCK;
2069
2070 if (rule->au_seqno < latest_granting) {
2071 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2072 "selinux_audit_rule_match: stale rule\n");
2073 match = -ESTALE;
2074 goto out;
2075 }
2076
2077 ctxt = sidtab_search(&sidtab, sid);
2078 if (!ctxt) {
2079 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2080 "selinux_audit_rule_match: unrecognized SID %d\n",
2081 sid);
2082 match = -ENOENT;
2083 goto out;
2084 }
2085
2086 /* a field/op pair that is not caught here will simply fall through
2087 without a match */
2088 switch (field) {
2089 case AUDIT_SUBJ_USER:
2090 case AUDIT_OBJ_USER:
2091 switch (op) {
2092 case AUDIT_EQUAL:
2093 match = (ctxt->user == rule->au_ctxt.user);
2094 break;
2095 case AUDIT_NOT_EQUAL:
2096 match = (ctxt->user != rule->au_ctxt.user);
2097 break;
2098 }
2099 break;
2100 case AUDIT_SUBJ_ROLE:
2101 case AUDIT_OBJ_ROLE:
2102 switch (op) {
2103 case AUDIT_EQUAL:
2104 match = (ctxt->role == rule->au_ctxt.role);
2105 break;
2106 case AUDIT_NOT_EQUAL:
2107 match = (ctxt->role != rule->au_ctxt.role);
2108 break;
2109 }
2110 break;
2111 case AUDIT_SUBJ_TYPE:
2112 case AUDIT_OBJ_TYPE:
2113 switch (op) {
2114 case AUDIT_EQUAL:
2115 match = (ctxt->type == rule->au_ctxt.type);
2116 break;
2117 case AUDIT_NOT_EQUAL:
2118 match = (ctxt->type != rule->au_ctxt.type);
2119 break;
2120 }
2121 break;
2122 case AUDIT_SUBJ_SEN:
2123 case AUDIT_SUBJ_CLR:
2124 case AUDIT_OBJ_LEV_LOW:
2125 case AUDIT_OBJ_LEV_HIGH:
2126 level = ((field == AUDIT_SUBJ_SEN ||
2127 field == AUDIT_OBJ_LEV_LOW) ?
2128 &ctxt->range.level[0] : &ctxt->range.level[1]);
2129 switch (op) {
2130 case AUDIT_EQUAL:
2131 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2132 level);
2133 break;
2134 case AUDIT_NOT_EQUAL:
2135 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2136 level);
2137 break;
2138 case AUDIT_LESS_THAN:
2139 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2140 level) &&
2141 !mls_level_eq(&rule->au_ctxt.range.level[0],
2142 level));
2143 break;
2144 case AUDIT_LESS_THAN_OR_EQUAL:
2145 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2146 level);
2147 break;
2148 case AUDIT_GREATER_THAN:
2149 match = (mls_level_dom(level,
2150 &rule->au_ctxt.range.level[0]) &&
2151 !mls_level_eq(level,
2152 &rule->au_ctxt.range.level[0]));
2153 break;
2154 case AUDIT_GREATER_THAN_OR_EQUAL:
2155 match = mls_level_dom(level,
2156 &rule->au_ctxt.range.level[0]);
2157 break;
2158 }
2159 }
2160
2161 out:
2162 POLICY_RDUNLOCK;
2163 return match;
2164 }
2165
2166 static int (*aurule_callback)(void) = NULL;
2167
2168 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2169 u16 class, u32 perms, u32 *retained)
2170 {
2171 int err = 0;
2172
2173 if (event == AVC_CALLBACK_RESET && aurule_callback)
2174 err = aurule_callback();
2175 return err;
2176 }
2177
2178 static int __init aurule_init(void)
2179 {
2180 int err;
2181
2182 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2183 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2184 if (err)
2185 panic("avc_add_callback() failed, error %d\n", err);
2186
2187 return err;
2188 }
2189 __initcall(aurule_init);
2190
2191 void selinux_audit_set_callback(int (*callback)(void))
2192 {
2193 aurule_callback = callback;
2194 }
2195
2196 /**
2197 * security_skb_extlbl_sid - Determine the external label of a packet
2198 * @skb: the packet
2199 * @base_sid: the SELinux SID to use as a context for MLS only external labels
2200 * @sid: the packet's SID
2201 *
2202 * Description:
2203 * Check the various different forms of external packet labeling and determine
2204 * the external SID for the packet.
2205 *
2206 */
2207 void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid)
2208 {
2209 u32 xfrm_sid;
2210 u32 nlbl_sid;
2211
2212 selinux_skb_xfrm_sid(skb, &xfrm_sid);
2213 if (selinux_netlbl_skbuff_getsid(skb,
2214 (xfrm_sid == SECSID_NULL ?
2215 base_sid : xfrm_sid),
2216 &nlbl_sid) != 0)
2217 nlbl_sid = SECSID_NULL;
2218
2219 *sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
2220 }
2221
2222 #ifdef CONFIG_NETLABEL
2223 /*
2224 * This is the structure we store inside the NetLabel cache block.
2225 */
2226 #define NETLBL_CACHE(x) ((struct netlbl_cache *)(x))
2227 #define NETLBL_CACHE_T_NONE 0
2228 #define NETLBL_CACHE_T_SID 1
2229 #define NETLBL_CACHE_T_MLS 2
2230 struct netlbl_cache {
2231 u32 type;
2232 union {
2233 u32 sid;
2234 struct mls_range mls_label;
2235 } data;
2236 };
2237
2238 /**
2239 * selinux_netlbl_cache_free - Free the NetLabel cached data
2240 * @data: the data to free
2241 *
2242 * Description:
2243 * This function is intended to be used as the free() callback inside the
2244 * netlbl_lsm_cache structure.
2245 *
2246 */
2247 static void selinux_netlbl_cache_free(const void *data)
2248 {
2249 struct netlbl_cache *cache;
2250
2251 if (data == NULL)
2252 return;
2253
2254 cache = NETLBL_CACHE(data);
2255 switch (cache->type) {
2256 case NETLBL_CACHE_T_MLS:
2257 ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2258 break;
2259 }
2260 kfree(data);
2261 }
2262
2263 /**
2264 * selinux_netlbl_cache_add - Add an entry to the NetLabel cache
2265 * @skb: the packet
2266 * @ctx: the SELinux context
2267 *
2268 * Description:
2269 * Attempt to cache the context in @ctx, which was derived from the packet in
2270 * @skb, in the NetLabel subsystem cache.
2271 *
2272 */
2273 static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx)
2274 {
2275 struct netlbl_cache *cache = NULL;
2276 struct netlbl_lsm_secattr secattr;
2277
2278 netlbl_secattr_init(&secattr);
2279 secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2280 if (secattr.cache == NULL)
2281 goto netlbl_cache_add_return;
2282
2283 cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2284 if (cache == NULL)
2285 goto netlbl_cache_add_return;
2286
2287 cache->type = NETLBL_CACHE_T_MLS;
2288 if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2289 &ctx->range.level[0].cat) != 0)
2290 goto netlbl_cache_add_return;
2291 cache->data.mls_label.level[1].cat.highbit =
2292 cache->data.mls_label.level[0].cat.highbit;
2293 cache->data.mls_label.level[1].cat.node =
2294 cache->data.mls_label.level[0].cat.node;
2295 cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2296 cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2297
2298 secattr.cache->free = selinux_netlbl_cache_free;
2299 secattr.cache->data = (void *)cache;
2300 secattr.flags = NETLBL_SECATTR_CACHE;
2301
2302 netlbl_cache_add(skb, &secattr);
2303
2304 netlbl_cache_add_return:
2305 netlbl_secattr_destroy(&secattr);
2306 }
2307
2308 /**
2309 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
2310 *
2311 * Description:
2312 * Invalidate the NetLabel security attribute mapping cache.
2313 *
2314 */
2315 void selinux_netlbl_cache_invalidate(void)
2316 {
2317 netlbl_cache_invalidate();
2318 }
2319
2320 /**
2321 * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2322 * @skb: the network packet
2323 * @secattr: the NetLabel packet security attributes
2324 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2325 * @sid: the SELinux SID
2326 *
2327 * Description:
2328 * Convert the given NetLabel packet security attributes in @secattr into a
2329 * SELinux SID. If the @secattr field does not contain a full SELinux
2330 * SID/context then use the context in @base_sid as the foundation. If @skb
2331 * is not NULL attempt to cache as much data as possibile. Returns zero on
2332 * success, negative values on failure.
2333 *
2334 */
2335 static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
2336 struct netlbl_lsm_secattr *secattr,
2337 u32 base_sid,
2338 u32 *sid)
2339 {
2340 int rc = -EIDRM;
2341 struct context *ctx;
2342 struct context ctx_new;
2343 struct netlbl_cache *cache;
2344
2345 POLICY_RDLOCK;
2346
2347 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2348 cache = NETLBL_CACHE(secattr->cache->data);
2349 switch (cache->type) {
2350 case NETLBL_CACHE_T_SID:
2351 *sid = cache->data.sid;
2352 rc = 0;
2353 break;
2354 case NETLBL_CACHE_T_MLS:
2355 ctx = sidtab_search(&sidtab, base_sid);
2356 if (ctx == NULL)
2357 goto netlbl_secattr_to_sid_return;
2358
2359 ctx_new.user = ctx->user;
2360 ctx_new.role = ctx->role;
2361 ctx_new.type = ctx->type;
2362 ctx_new.range.level[0].sens =
2363 cache->data.mls_label.level[0].sens;
2364 ctx_new.range.level[0].cat.highbit =
2365 cache->data.mls_label.level[0].cat.highbit;
2366 ctx_new.range.level[0].cat.node =
2367 cache->data.mls_label.level[0].cat.node;
2368 ctx_new.range.level[1].sens =
2369 cache->data.mls_label.level[1].sens;
2370 ctx_new.range.level[1].cat.highbit =
2371 cache->data.mls_label.level[1].cat.highbit;
2372 ctx_new.range.level[1].cat.node =
2373 cache->data.mls_label.level[1].cat.node;
2374
2375 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2376 break;
2377 default:
2378 goto netlbl_secattr_to_sid_return;
2379 }
2380 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2381 ctx = sidtab_search(&sidtab, base_sid);
2382 if (ctx == NULL)
2383 goto netlbl_secattr_to_sid_return;
2384
2385 ctx_new.user = ctx->user;
2386 ctx_new.role = ctx->role;
2387 ctx_new.type = ctx->type;
2388 mls_import_netlbl_lvl(&ctx_new, secattr);
2389 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2390 if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2391 secattr->mls_cat) != 0)
2392 goto netlbl_secattr_to_sid_return;
2393 ctx_new.range.level[1].cat.highbit =
2394 ctx_new.range.level[0].cat.highbit;
2395 ctx_new.range.level[1].cat.node =
2396 ctx_new.range.level[0].cat.node;
2397 } else {
2398 ebitmap_init(&ctx_new.range.level[0].cat);
2399 ebitmap_init(&ctx_new.range.level[1].cat);
2400 }
2401 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2402 goto netlbl_secattr_to_sid_return_cleanup;
2403
2404 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2405 if (rc != 0)
2406 goto netlbl_secattr_to_sid_return_cleanup;
2407
2408 if (skb != NULL)
2409 selinux_netlbl_cache_add(skb, &ctx_new);
2410 ebitmap_destroy(&ctx_new.range.level[0].cat);
2411 } else {
2412 *sid = SECSID_NULL;
2413 rc = 0;
2414 }
2415
2416 netlbl_secattr_to_sid_return:
2417 POLICY_RDUNLOCK;
2418 return rc;
2419 netlbl_secattr_to_sid_return_cleanup:
2420 ebitmap_destroy(&ctx_new.range.level[0].cat);
2421 goto netlbl_secattr_to_sid_return;
2422 }
2423
2424 /**
2425 * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
2426 * @skb: the packet
2427 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2428 * @sid: the SID
2429 *
2430 * Description:
2431 * Call the NetLabel mechanism to get the security attributes of the given
2432 * packet and use those attributes to determine the correct context/SID to
2433 * assign to the packet. Returns zero on success, negative values on failure.
2434 *
2435 */
2436 int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
2437 {
2438 int rc;
2439 struct netlbl_lsm_secattr secattr;
2440
2441 netlbl_secattr_init(&secattr);
2442 rc = netlbl_skbuff_getattr(skb, &secattr);
2443 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2444 rc = selinux_netlbl_secattr_to_sid(skb,
2445 &secattr,
2446 base_sid,
2447 sid);
2448 else
2449 *sid = SECSID_NULL;
2450 netlbl_secattr_destroy(&secattr);
2451
2452 return rc;
2453 }
2454
2455 /**
2456 * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism
2457 * @sock: the socket to label
2458 * @sid: the SID to use
2459 *
2460 * Description:
2461 * Attempt to label a socket using the NetLabel mechanism using the given
2462 * SID. Returns zero values on success, negative values on failure. The
2463 * caller is responsibile for calling rcu_read_lock() before calling this
2464 * this function and rcu_read_unlock() after this function returns.
2465 *
2466 */
2467 static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
2468 {
2469 int rc = -ENOENT;
2470 struct sk_security_struct *sksec = sock->sk->sk_security;
2471 struct netlbl_lsm_secattr secattr;
2472 struct context *ctx;
2473
2474 if (!ss_initialized)
2475 return 0;
2476
2477 netlbl_secattr_init(&secattr);
2478
2479 POLICY_RDLOCK;
2480
2481 ctx = sidtab_search(&sidtab, sid);
2482 if (ctx == NULL)
2483 goto netlbl_socket_setsid_return;
2484
2485 secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2486 GFP_ATOMIC);
2487 secattr.flags |= NETLBL_SECATTR_DOMAIN;
2488 mls_export_netlbl_lvl(ctx, &secattr);
2489 rc = mls_export_netlbl_cat(ctx, &secattr);
2490 if (rc != 0)
2491 goto netlbl_socket_setsid_return;
2492
2493 rc = netlbl_socket_setattr(sock, &secattr);
2494 if (rc == 0) {
2495 spin_lock(&sksec->nlbl_lock);
2496 sksec->nlbl_state = NLBL_LABELED;
2497 spin_unlock(&sksec->nlbl_lock);
2498 }
2499
2500 netlbl_socket_setsid_return:
2501 POLICY_RDUNLOCK;
2502 netlbl_secattr_destroy(&secattr);
2503 return rc;
2504 }
2505
2506 /**
2507 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
2508 * @ssec: the sk_security_struct
2509 * @family: the socket family
2510 *
2511 * Description:
2512 * Called when the NetLabel state of a sk_security_struct needs to be reset.
2513 * The caller is responsibile for all the NetLabel sk_security_struct locking.
2514 *
2515 */
2516 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
2517 int family)
2518 {
2519 if (family == PF_INET)
2520 ssec->nlbl_state = NLBL_REQUIRE;
2521 else
2522 ssec->nlbl_state = NLBL_UNSET;
2523 }
2524
2525 /**
2526 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
2527 * @ssec: the sk_security_struct
2528 * @family: the socket family
2529 *
2530 * Description:
2531 * Called when a new sk_security_struct is allocated to initialize the NetLabel
2532 * fields.
2533 *
2534 */
2535 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
2536 int family)
2537 {
2538 /* No locking needed, we are the only one who has access to ssec */
2539 selinux_netlbl_sk_security_reset(ssec, family);
2540 spin_lock_init(&ssec->nlbl_lock);
2541 }
2542
2543 /**
2544 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
2545 * @ssec: the original sk_security_struct
2546 * @newssec: the cloned sk_security_struct
2547 *
2548 * Description:
2549 * Clone the NetLabel specific sk_security_struct fields from @ssec to
2550 * @newssec.
2551 *
2552 */
2553 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
2554 struct sk_security_struct *newssec)
2555 {
2556 /* We don't need to take newssec->nlbl_lock because we are the only
2557 * thread with access to newssec, but we do need to take the RCU read
2558 * lock as other threads could have access to ssec */
2559 rcu_read_lock();
2560 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
2561 newssec->sclass = ssec->sclass;
2562 rcu_read_unlock();
2563 }
2564
2565 /**
2566 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
2567 * @sock: the socket to label
2568 *
2569 * Description:
2570 * Attempt to label a socket using the NetLabel mechanism using the given
2571 * SID. Returns zero values on success, negative values on failure.
2572 *
2573 */
2574 int selinux_netlbl_socket_post_create(struct socket *sock)
2575 {
2576 int rc = 0;
2577 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2578 struct sk_security_struct *sksec = sock->sk->sk_security;
2579
2580 sksec->sclass = isec->sclass;
2581
2582 rcu_read_lock();
2583 if (sksec->nlbl_state == NLBL_REQUIRE)
2584 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2585 rcu_read_unlock();
2586
2587 return rc;
2588 }
2589
2590 /**
2591 * selinux_netlbl_sock_graft - Netlabel the new socket
2592 * @sk: the new connection
2593 * @sock: the new socket
2594 *
2595 * Description:
2596 * The connection represented by @sk is being grafted onto @sock so set the
2597 * socket's NetLabel to match the SID of @sk.
2598 *
2599 */
2600 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
2601 {
2602 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2603 struct sk_security_struct *sksec = sk->sk_security;
2604 struct netlbl_lsm_secattr secattr;
2605 u32 nlbl_peer_sid;
2606
2607 sksec->sclass = isec->sclass;
2608
2609 rcu_read_lock();
2610
2611 if (sksec->nlbl_state != NLBL_REQUIRE) {
2612 rcu_read_unlock();
2613 return;
2614 }
2615
2616 netlbl_secattr_init(&secattr);
2617 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
2618 secattr.flags != NETLBL_SECATTR_NONE &&
2619 selinux_netlbl_secattr_to_sid(NULL,
2620 &secattr,
2621 SECINITSID_UNLABELED,
2622 &nlbl_peer_sid) == 0)
2623 sksec->peer_sid = nlbl_peer_sid;
2624 netlbl_secattr_destroy(&secattr);
2625
2626 /* Try to set the NetLabel on the socket to save time later, if we fail
2627 * here we will pick up the pieces in later calls to
2628 * selinux_netlbl_inode_permission(). */
2629 selinux_netlbl_socket_setsid(sock, sksec->sid);
2630
2631 rcu_read_unlock();
2632 }
2633
2634 /**
2635 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
2636 * @inode: the file descriptor's inode
2637 * @mask: the permission mask
2638 *
2639 * Description:
2640 * Looks at a file's inode and if it is marked as a socket protected by
2641 * NetLabel then verify that the socket has been labeled, if not try to label
2642 * the socket now with the inode's SID. Returns zero on success, negative
2643 * values on failure.
2644 *
2645 */
2646 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
2647 {
2648 int rc;
2649 struct sk_security_struct *sksec;
2650 struct socket *sock;
2651
2652 if (!S_ISSOCK(inode->i_mode) ||
2653 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
2654 return 0;
2655 sock = SOCKET_I(inode);
2656 sksec = sock->sk->sk_security;
2657
2658 rcu_read_lock();
2659 if (sksec->nlbl_state != NLBL_REQUIRE) {
2660 rcu_read_unlock();
2661 return 0;
2662 }
2663 lock_sock(sock->sk);
2664 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2665 release_sock(sock->sk);
2666 rcu_read_unlock();
2667
2668 return rc;
2669 }
2670
2671 /**
2672 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
2673 * @sksec: the sock's sk_security_struct
2674 * @skb: the packet
2675 * @ad: the audit data
2676 *
2677 * Description:
2678 * Fetch the NetLabel security attributes from @skb and perform an access check
2679 * against the receiving socket. Returns zero on success, negative values on
2680 * error.
2681 *
2682 */
2683 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
2684 struct sk_buff *skb,
2685 struct avc_audit_data *ad)
2686 {
2687 int rc;
2688 u32 netlbl_sid;
2689 u32 recv_perm;
2690
2691 rc = selinux_netlbl_skbuff_getsid(skb,
2692 SECINITSID_UNLABELED,
2693 &netlbl_sid);
2694 if (rc != 0)
2695 return rc;
2696
2697 if (netlbl_sid == SECSID_NULL)
2698 return 0;
2699
2700 switch (sksec->sclass) {
2701 case SECCLASS_UDP_SOCKET:
2702 recv_perm = UDP_SOCKET__RECVFROM;
2703 break;
2704 case SECCLASS_TCP_SOCKET:
2705 recv_perm = TCP_SOCKET__RECVFROM;
2706 break;
2707 default:
2708 recv_perm = RAWIP_SOCKET__RECVFROM;
2709 }
2710
2711 rc = avc_has_perm(sksec->sid,
2712 netlbl_sid,
2713 sksec->sclass,
2714 recv_perm,
2715 ad);
2716 if (rc == 0)
2717 return 0;
2718
2719 netlbl_skbuff_err(skb, rc);
2720 return rc;
2721 }
2722
2723 /**
2724 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
2725 * @sock: the socket
2726 * @level: the socket level or protocol
2727 * @optname: the socket option name
2728 *
2729 * Description:
2730 * Check the setsockopt() call and if the user is trying to replace the IP
2731 * options on a socket and a NetLabel is in place for the socket deny the
2732 * access; otherwise allow the access. Returns zero when the access is
2733 * allowed, -EACCES when denied, and other negative values on error.
2734 *
2735 */
2736 int selinux_netlbl_socket_setsockopt(struct socket *sock,
2737 int level,
2738 int optname)
2739 {
2740 int rc = 0;
2741 struct sk_security_struct *sksec = sock->sk->sk_security;
2742 struct netlbl_lsm_secattr secattr;
2743
2744 rcu_read_lock();
2745 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
2746 sksec->nlbl_state == NLBL_LABELED) {
2747 netlbl_secattr_init(&secattr);
2748 rc = netlbl_socket_getattr(sock, &secattr);
2749 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2750 rc = -EACCES;
2751 netlbl_secattr_destroy(&secattr);
2752 }
2753 rcu_read_unlock();
2754
2755 return rc;
2756 }
2757 #endif /* CONFIG_NETLABEL */
hh.org GIT migration