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SELinux: peer secid consolidation for external network labeling
[linux-2.6.22.y-op.git] / security / selinux / ss / services.c
blobb43dd803fd5e513cdc0abd4ece30201d273c6657
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
59 extern void selnl_notify_policyload(u32 seqno);
60 unsigned int policydb_loaded_version;
61
62 /*
63 * This is declared in avc.c
64 */
65 extern const struct selinux_class_perm selinux_class_perm;
66
67 static DEFINE_RWLOCK(policy_rwlock);
68 #define POLICY_RDLOCK read_lock(&policy_rwlock)
69 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
70 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
71 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
72
73 static DEFINE_MUTEX(load_mutex);
74 #define LOAD_LOCK mutex_lock(&load_mutex)
75 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
76
77 static struct sidtab sidtab;
78 struct policydb policydb;
79 int ss_initialized = 0;
80
81 /*
82 * The largest sequence number that has been used when
83 * providing an access decision to the access vector cache.
84 * The sequence number only changes when a policy change
85 * occurs.
86 */
87 static u32 latest_granting = 0;
88
89 /* Forward declaration. */
90 static int context_struct_to_string(struct context *context, char **scontext,
91 u32 *scontext_len);
92
93 /*
94 * Return the boolean value of a constraint expression
95 * when it is applied to the specified source and target
96 * security contexts.
97 *
98 * xcontext is a special beast... It is used by the validatetrans rules
99 * only. For these rules, scontext is the context before the transition,
100 * tcontext is the context after the transition, and xcontext is the context
101 * of the process performing the transition. All other callers of
102 * constraint_expr_eval should pass in NULL for xcontext.
103 */
104 static int constraint_expr_eval(struct context *scontext,
105 struct context *tcontext,
106 struct context *xcontext,
107 struct constraint_expr *cexpr)
108 {
109 u32 val1, val2;
110 struct context *c;
111 struct role_datum *r1, *r2;
112 struct mls_level *l1, *l2;
113 struct constraint_expr *e;
114 int s[CEXPR_MAXDEPTH];
115 int sp = -1;
116
117 for (e = cexpr; e; e = e->next) {
118 switch (e->expr_type) {
119 case CEXPR_NOT:
120 BUG_ON(sp < 0);
121 s[sp] = !s[sp];
122 break;
123 case CEXPR_AND:
124 BUG_ON(sp < 1);
125 sp--;
126 s[sp] &= s[sp+1];
127 break;
128 case CEXPR_OR:
129 BUG_ON(sp < 1);
130 sp--;
131 s[sp] |= s[sp+1];
132 break;
133 case CEXPR_ATTR:
134 if (sp == (CEXPR_MAXDEPTH-1))
135 return 0;
136 switch (e->attr) {
137 case CEXPR_USER:
138 val1 = scontext->user;
139 val2 = tcontext->user;
140 break;
141 case CEXPR_TYPE:
142 val1 = scontext->type;
143 val2 = tcontext->type;
144 break;
145 case CEXPR_ROLE:
146 val1 = scontext->role;
147 val2 = tcontext->role;
148 r1 = policydb.role_val_to_struct[val1 - 1];
149 r2 = policydb.role_val_to_struct[val2 - 1];
150 switch (e->op) {
151 case CEXPR_DOM:
152 s[++sp] = ebitmap_get_bit(&r1->dominates,
153 val2 - 1);
154 continue;
155 case CEXPR_DOMBY:
156 s[++sp] = ebitmap_get_bit(&r2->dominates,
157 val1 - 1);
158 continue;
159 case CEXPR_INCOMP:
160 s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
161 val2 - 1) &&
162 !ebitmap_get_bit(&r2->dominates,
163 val1 - 1) );
164 continue;
165 default:
166 break;
167 }
168 break;
169 case CEXPR_L1L2:
170 l1 = &(scontext->range.level[0]);
171 l2 = &(tcontext->range.level[0]);
172 goto mls_ops;
173 case CEXPR_L1H2:
174 l1 = &(scontext->range.level[0]);
175 l2 = &(tcontext->range.level[1]);
176 goto mls_ops;
177 case CEXPR_H1L2:
178 l1 = &(scontext->range.level[1]);
179 l2 = &(tcontext->range.level[0]);
180 goto mls_ops;
181 case CEXPR_H1H2:
182 l1 = &(scontext->range.level[1]);
183 l2 = &(tcontext->range.level[1]);
184 goto mls_ops;
185 case CEXPR_L1H1:
186 l1 = &(scontext->range.level[0]);
187 l2 = &(scontext->range.level[1]);
188 goto mls_ops;
189 case CEXPR_L2H2:
190 l1 = &(tcontext->range.level[0]);
191 l2 = &(tcontext->range.level[1]);
192 goto mls_ops;
193 mls_ops:
194 switch (e->op) {
195 case CEXPR_EQ:
196 s[++sp] = mls_level_eq(l1, l2);
197 continue;
198 case CEXPR_NEQ:
199 s[++sp] = !mls_level_eq(l1, l2);
200 continue;
201 case CEXPR_DOM:
202 s[++sp] = mls_level_dom(l1, l2);
203 continue;
204 case CEXPR_DOMBY:
205 s[++sp] = mls_level_dom(l2, l1);
206 continue;
207 case CEXPR_INCOMP:
208 s[++sp] = mls_level_incomp(l2, l1);
209 continue;
210 default:
211 BUG();
212 return 0;
213 }
214 break;
215 default:
216 BUG();
217 return 0;
218 }
219
220 switch (e->op) {
221 case CEXPR_EQ:
222 s[++sp] = (val1 == val2);
223 break;
224 case CEXPR_NEQ:
225 s[++sp] = (val1 != val2);
226 break;
227 default:
228 BUG();
229 return 0;
230 }
231 break;
232 case CEXPR_NAMES:
233 if (sp == (CEXPR_MAXDEPTH-1))
234 return 0;
235 c = scontext;
236 if (e->attr & CEXPR_TARGET)
237 c = tcontext;
238 else if (e->attr & CEXPR_XTARGET) {
239 c = xcontext;
240 if (!c) {
241 BUG();
242 return 0;
243 }
244 }
245 if (e->attr & CEXPR_USER)
246 val1 = c->user;
247 else if (e->attr & CEXPR_ROLE)
248 val1 = c->role;
249 else if (e->attr & CEXPR_TYPE)
250 val1 = c->type;
251 else {
252 BUG();
253 return 0;
254 }
255
256 switch (e->op) {
257 case CEXPR_EQ:
258 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
259 break;
260 case CEXPR_NEQ:
261 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
262 break;
263 default:
264 BUG();
265 return 0;
266 }
267 break;
268 default:
269 BUG();
270 return 0;
271 }
272 }
273
274 BUG_ON(sp != 0);
275 return s[0];
276 }
277
278 /*
279 * Compute access vectors based on a context structure pair for
280 * the permissions in a particular class.
281 */
282 static int context_struct_compute_av(struct context *scontext,
283 struct context *tcontext,
284 u16 tclass,
285 u32 requested,
286 struct av_decision *avd)
287 {
288 struct constraint_node *constraint;
289 struct role_allow *ra;
290 struct avtab_key avkey;
291 struct avtab_node *node;
292 struct class_datum *tclass_datum;
293 struct ebitmap *sattr, *tattr;
294 struct ebitmap_node *snode, *tnode;
295 unsigned int i, j;
296
297 /*
298 * Remap extended Netlink classes for old policy versions.
299 * Do this here rather than socket_type_to_security_class()
300 * in case a newer policy version is loaded, allowing sockets
301 * to remain in the correct class.
302 */
303 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
304 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
305 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
306 tclass = SECCLASS_NETLINK_SOCKET;
307
308 if (!tclass || tclass > policydb.p_classes.nprim) {
309 printk(KERN_ERR "security_compute_av: unrecognized class %d\n",
310 tclass);
311 return -EINVAL;
312 }
313 tclass_datum = policydb.class_val_to_struct[tclass - 1];
314
315 /*
316 * Initialize the access vectors to the default values.
317 */
318 avd->allowed = 0;
319 avd->decided = 0xffffffff;
320 avd->auditallow = 0;
321 avd->auditdeny = 0xffffffff;
322 avd->seqno = latest_granting;
323
324 /*
325 * If a specific type enforcement rule was defined for
326 * this permission check, then use it.
327 */
328 avkey.target_class = tclass;
329 avkey.specified = AVTAB_AV;
330 sattr = &policydb.type_attr_map[scontext->type - 1];
331 tattr = &policydb.type_attr_map[tcontext->type - 1];
332 ebitmap_for_each_bit(sattr, snode, i) {
333 if (!ebitmap_node_get_bit(snode, i))
334 continue;
335 ebitmap_for_each_bit(tattr, tnode, j) {
336 if (!ebitmap_node_get_bit(tnode, j))
337 continue;
338 avkey.source_type = i + 1;
339 avkey.target_type = j + 1;
340 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
341 node != NULL;
342 node = avtab_search_node_next(node, avkey.specified)) {
343 if (node->key.specified == AVTAB_ALLOWED)
344 avd->allowed |= node->datum.data;
345 else if (node->key.specified == AVTAB_AUDITALLOW)
346 avd->auditallow |= node->datum.data;
347 else if (node->key.specified == AVTAB_AUDITDENY)
348 avd->auditdeny &= node->datum.data;
349 }
350
351 /* Check conditional av table for additional permissions */
352 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
353
354 }
355 }
356
357 /*
358 * Remove any permissions prohibited by a constraint (this includes
359 * the MLS policy).
360 */
361 constraint = tclass_datum->constraints;
362 while (constraint) {
363 if ((constraint->permissions & (avd->allowed)) &&
364 !constraint_expr_eval(scontext, tcontext, NULL,
365 constraint->expr)) {
366 avd->allowed = (avd->allowed) & ~(constraint->permissions);
367 }
368 constraint = constraint->next;
369 }
370
371 /*
372 * If checking process transition permission and the
373 * role is changing, then check the (current_role, new_role)
374 * pair.
375 */
376 if (tclass == SECCLASS_PROCESS &&
377 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
378 scontext->role != tcontext->role) {
379 for (ra = policydb.role_allow; ra; ra = ra->next) {
380 if (scontext->role == ra->role &&
381 tcontext->role == ra->new_role)
382 break;
383 }
384 if (!ra)
385 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
386 PROCESS__DYNTRANSITION);
387 }
388
389 return 0;
390 }
391
392 static int security_validtrans_handle_fail(struct context *ocontext,
393 struct context *ncontext,
394 struct context *tcontext,
395 u16 tclass)
396 {
397 char *o = NULL, *n = NULL, *t = NULL;
398 u32 olen, nlen, tlen;
399
400 if (context_struct_to_string(ocontext, &o, &olen) < 0)
401 goto out;
402 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
403 goto out;
404 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
405 goto out;
406 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
407 "security_validate_transition: denied for"
408 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
409 o, n, t, policydb.p_class_val_to_name[tclass-1]);
410 out:
411 kfree(o);
412 kfree(n);
413 kfree(t);
414
415 if (!selinux_enforcing)
416 return 0;
417 return -EPERM;
418 }
419
420 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
421 u16 tclass)
422 {
423 struct context *ocontext;
424 struct context *ncontext;
425 struct context *tcontext;
426 struct class_datum *tclass_datum;
427 struct constraint_node *constraint;
428 int rc = 0;
429
430 if (!ss_initialized)
431 return 0;
432
433 POLICY_RDLOCK;
434
435 /*
436 * Remap extended Netlink classes for old policy versions.
437 * Do this here rather than socket_type_to_security_class()
438 * in case a newer policy version is loaded, allowing sockets
439 * to remain in the correct class.
440 */
441 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
442 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
443 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
444 tclass = SECCLASS_NETLINK_SOCKET;
445
446 if (!tclass || tclass > policydb.p_classes.nprim) {
447 printk(KERN_ERR "security_validate_transition: "
448 "unrecognized class %d\n", tclass);
449 rc = -EINVAL;
450 goto out;
451 }
452 tclass_datum = policydb.class_val_to_struct[tclass - 1];
453
454 ocontext = sidtab_search(&sidtab, oldsid);
455 if (!ocontext) {
456 printk(KERN_ERR "security_validate_transition: "
457 " unrecognized SID %d\n", oldsid);
458 rc = -EINVAL;
459 goto out;
460 }
461
462 ncontext = sidtab_search(&sidtab, newsid);
463 if (!ncontext) {
464 printk(KERN_ERR "security_validate_transition: "
465 " unrecognized SID %d\n", newsid);
466 rc = -EINVAL;
467 goto out;
468 }
469
470 tcontext = sidtab_search(&sidtab, tasksid);
471 if (!tcontext) {
472 printk(KERN_ERR "security_validate_transition: "
473 " unrecognized SID %d\n", tasksid);
474 rc = -EINVAL;
475 goto out;
476 }
477
478 constraint = tclass_datum->validatetrans;
479 while (constraint) {
480 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
481 constraint->expr)) {
482 rc = security_validtrans_handle_fail(ocontext, ncontext,
483 tcontext, tclass);
484 goto out;
485 }
486 constraint = constraint->next;
487 }
488
489 out:
490 POLICY_RDUNLOCK;
491 return rc;
492 }
493
494 /**
495 * security_compute_av - Compute access vector decisions.
496 * @ssid: source security identifier
497 * @tsid: target security identifier
498 * @tclass: target security class
499 * @requested: requested permissions
500 * @avd: access vector decisions
501 *
502 * Compute a set of access vector decisions based on the
503 * SID pair (@ssid, @tsid) for the permissions in @tclass.
504 * Return -%EINVAL if any of the parameters are invalid or %0
505 * if the access vector decisions were computed successfully.
506 */
507 int security_compute_av(u32 ssid,
508 u32 tsid,
509 u16 tclass,
510 u32 requested,
511 struct av_decision *avd)
512 {
513 struct context *scontext = NULL, *tcontext = NULL;
514 int rc = 0;
515
516 if (!ss_initialized) {
517 avd->allowed = 0xffffffff;
518 avd->decided = 0xffffffff;
519 avd->auditallow = 0;
520 avd->auditdeny = 0xffffffff;
521 avd->seqno = latest_granting;
522 return 0;
523 }
524
525 POLICY_RDLOCK;
526
527 scontext = sidtab_search(&sidtab, ssid);
528 if (!scontext) {
529 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
530 ssid);
531 rc = -EINVAL;
532 goto out;
533 }
534 tcontext = sidtab_search(&sidtab, tsid);
535 if (!tcontext) {
536 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
537 tsid);
538 rc = -EINVAL;
539 goto out;
540 }
541
542 rc = context_struct_compute_av(scontext, tcontext, tclass,
543 requested, avd);
544 out:
545 POLICY_RDUNLOCK;
546 return rc;
547 }
548
549 /*
550 * Write the security context string representation of
551 * the context structure `context' into a dynamically
552 * allocated string of the correct size. Set `*scontext'
553 * to point to this string and set `*scontext_len' to
554 * the length of the string.
555 */
556 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
557 {
558 char *scontextp;
559
560 *scontext = NULL;
561 *scontext_len = 0;
562
563 /* Compute the size of the context. */
564 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
565 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
566 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
567 *scontext_len += mls_compute_context_len(context);
568
569 /* Allocate space for the context; caller must free this space. */
570 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
571 if (!scontextp) {
572 return -ENOMEM;
573 }
574 *scontext = scontextp;
575
576 /*
577 * Copy the user name, role name and type name into the context.
578 */
579 sprintf(scontextp, "%s:%s:%s",
580 policydb.p_user_val_to_name[context->user - 1],
581 policydb.p_role_val_to_name[context->role - 1],
582 policydb.p_type_val_to_name[context->type - 1]);
583 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
584 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
585 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
586
587 mls_sid_to_context(context, &scontextp);
588
589 *scontextp = 0;
590
591 return 0;
592 }
593
594 #include "initial_sid_to_string.h"
595
596 /**
597 * security_sid_to_context - Obtain a context for a given SID.
598 * @sid: security identifier, SID
599 * @scontext: security context
600 * @scontext_len: length in bytes
601 *
602 * Write the string representation of the context associated with @sid
603 * into a dynamically allocated string of the correct size. Set @scontext
604 * to point to this string and set @scontext_len to the length of the string.
605 */
606 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
607 {
608 struct context *context;
609 int rc = 0;
610
611 if (!ss_initialized) {
612 if (sid <= SECINITSID_NUM) {
613 char *scontextp;
614
615 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
616 scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
617 if (!scontextp) {
618 rc = -ENOMEM;
619 goto out;
620 }
621 strcpy(scontextp, initial_sid_to_string[sid]);
622 *scontext = scontextp;
623 goto out;
624 }
625 printk(KERN_ERR "security_sid_to_context: called before initial "
626 "load_policy on unknown SID %d\n", sid);
627 rc = -EINVAL;
628 goto out;
629 }
630 POLICY_RDLOCK;
631 context = sidtab_search(&sidtab, sid);
632 if (!context) {
633 printk(KERN_ERR "security_sid_to_context: unrecognized SID "
634 "%d\n", sid);
635 rc = -EINVAL;
636 goto out_unlock;
637 }
638 rc = context_struct_to_string(context, scontext, scontext_len);
639 out_unlock:
640 POLICY_RDUNLOCK;
641 out:
642 return rc;
643
644 }
645
646 static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
647 {
648 char *scontext2;
649 struct context context;
650 struct role_datum *role;
651 struct type_datum *typdatum;
652 struct user_datum *usrdatum;
653 char *scontextp, *p, oldc;
654 int rc = 0;
655
656 if (!ss_initialized) {
657 int i;
658
659 for (i = 1; i < SECINITSID_NUM; i++) {
660 if (!strcmp(initial_sid_to_string[i], scontext)) {
661 *sid = i;
662 goto out;
663 }
664 }
665 *sid = SECINITSID_KERNEL;
666 goto out;
667 }
668 *sid = SECSID_NULL;
669
670 /* Copy the string so that we can modify the copy as we parse it.
671 The string should already by null terminated, but we append a
672 null suffix to the copy to avoid problems with the existing
673 attr package, which doesn't view the null terminator as part
674 of the attribute value. */
675 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
676 if (!scontext2) {
677 rc = -ENOMEM;
678 goto out;
679 }
680 memcpy(scontext2, scontext, scontext_len);
681 scontext2[scontext_len] = 0;
682
683 context_init(&context);
684 *sid = SECSID_NULL;
685
686 POLICY_RDLOCK;
687
688 /* Parse the security context. */
689
690 rc = -EINVAL;
691 scontextp = (char *) scontext2;
692
693 /* Extract the user. */
694 p = scontextp;
695 while (*p && *p != ':')
696 p++;
697
698 if (*p == 0)
699 goto out_unlock;
700
701 *p++ = 0;
702
703 usrdatum = hashtab_search(policydb.p_users.table, scontextp);
704 if (!usrdatum)
705 goto out_unlock;
706
707 context.user = usrdatum->value;
708
709 /* Extract role. */
710 scontextp = p;
711 while (*p && *p != ':')
712 p++;
713
714 if (*p == 0)
715 goto out_unlock;
716
717 *p++ = 0;
718
719 role = hashtab_search(policydb.p_roles.table, scontextp);
720 if (!role)
721 goto out_unlock;
722 context.role = role->value;
723
724 /* Extract type. */
725 scontextp = p;
726 while (*p && *p != ':')
727 p++;
728 oldc = *p;
729 *p++ = 0;
730
731 typdatum = hashtab_search(policydb.p_types.table, scontextp);
732 if (!typdatum)
733 goto out_unlock;
734
735 context.type = typdatum->value;
736
737 rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
738 if (rc)
739 goto out_unlock;
740
741 if ((p - scontext2) < scontext_len) {
742 rc = -EINVAL;
743 goto out_unlock;
744 }
745
746 /* Check the validity of the new context. */
747 if (!policydb_context_isvalid(&policydb, &context)) {
748 rc = -EINVAL;
749 goto out_unlock;
750 }
751 /* Obtain the new sid. */
752 rc = sidtab_context_to_sid(&sidtab, &context, sid);
753 out_unlock:
754 POLICY_RDUNLOCK;
755 context_destroy(&context);
756 kfree(scontext2);
757 out:
758 return rc;
759 }
760
761 /**
762 * security_context_to_sid - Obtain a SID for a given security context.
763 * @scontext: security context
764 * @scontext_len: length in bytes
765 * @sid: security identifier, SID
766 *
767 * Obtains a SID associated with the security context that
768 * has the string representation specified by @scontext.
769 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
770 * memory is available, or 0 on success.
771 */
772 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
773 {
774 return security_context_to_sid_core(scontext, scontext_len,
775 sid, SECSID_NULL);
776 }
777
778 /**
779 * security_context_to_sid_default - Obtain a SID for a given security context,
780 * falling back to specified default if needed.
781 *
782 * @scontext: security context
783 * @scontext_len: length in bytes
784 * @sid: security identifier, SID
785 * @def_sid: default SID to assign on errror
786 *
787 * Obtains a SID associated with the security context that
788 * has the string representation specified by @scontext.
789 * The default SID is passed to the MLS layer to be used to allow
790 * kernel labeling of the MLS field if the MLS field is not present
791 * (for upgrading to MLS without full relabel).
792 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
793 * memory is available, or 0 on success.
794 */
795 int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
796 {
797 return security_context_to_sid_core(scontext, scontext_len,
798 sid, def_sid);
799 }
800
801 static int compute_sid_handle_invalid_context(
802 struct context *scontext,
803 struct context *tcontext,
804 u16 tclass,
805 struct context *newcontext)
806 {
807 char *s = NULL, *t = NULL, *n = NULL;
808 u32 slen, tlen, nlen;
809
810 if (context_struct_to_string(scontext, &s, &slen) < 0)
811 goto out;
812 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
813 goto out;
814 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
815 goto out;
816 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
817 "security_compute_sid: invalid context %s"
818 " for scontext=%s"
819 " tcontext=%s"
820 " tclass=%s",
821 n, s, t, policydb.p_class_val_to_name[tclass-1]);
822 out:
823 kfree(s);
824 kfree(t);
825 kfree(n);
826 if (!selinux_enforcing)
827 return 0;
828 return -EACCES;
829 }
830
831 static int security_compute_sid(u32 ssid,
832 u32 tsid,
833 u16 tclass,
834 u32 specified,
835 u32 *out_sid)
836 {
837 struct context *scontext = NULL, *tcontext = NULL, newcontext;
838 struct role_trans *roletr = NULL;
839 struct avtab_key avkey;
840 struct avtab_datum *avdatum;
841 struct avtab_node *node;
842 int rc = 0;
843
844 if (!ss_initialized) {
845 switch (tclass) {
846 case SECCLASS_PROCESS:
847 *out_sid = ssid;
848 break;
849 default:
850 *out_sid = tsid;
851 break;
852 }
853 goto out;
854 }
855
856 context_init(&newcontext);
857
858 POLICY_RDLOCK;
859
860 scontext = sidtab_search(&sidtab, ssid);
861 if (!scontext) {
862 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
863 ssid);
864 rc = -EINVAL;
865 goto out_unlock;
866 }
867 tcontext = sidtab_search(&sidtab, tsid);
868 if (!tcontext) {
869 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
870 tsid);
871 rc = -EINVAL;
872 goto out_unlock;
873 }
874
875 /* Set the user identity. */
876 switch (specified) {
877 case AVTAB_TRANSITION:
878 case AVTAB_CHANGE:
879 /* Use the process user identity. */
880 newcontext.user = scontext->user;
881 break;
882 case AVTAB_MEMBER:
883 /* Use the related object owner. */
884 newcontext.user = tcontext->user;
885 break;
886 }
887
888 /* Set the role and type to default values. */
889 switch (tclass) {
890 case SECCLASS_PROCESS:
891 /* Use the current role and type of process. */
892 newcontext.role = scontext->role;
893 newcontext.type = scontext->type;
894 break;
895 default:
896 /* Use the well-defined object role. */
897 newcontext.role = OBJECT_R_VAL;
898 /* Use the type of the related object. */
899 newcontext.type = tcontext->type;
900 }
901
902 /* Look for a type transition/member/change rule. */
903 avkey.source_type = scontext->type;
904 avkey.target_type = tcontext->type;
905 avkey.target_class = tclass;
906 avkey.specified = specified;
907 avdatum = avtab_search(&policydb.te_avtab, &avkey);
908
909 /* If no permanent rule, also check for enabled conditional rules */
910 if(!avdatum) {
911 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
912 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
913 if (node->key.specified & AVTAB_ENABLED) {
914 avdatum = &node->datum;
915 break;
916 }
917 }
918 }
919
920 if (avdatum) {
921 /* Use the type from the type transition/member/change rule. */
922 newcontext.type = avdatum->data;
923 }
924
925 /* Check for class-specific changes. */
926 switch (tclass) {
927 case SECCLASS_PROCESS:
928 if (specified & AVTAB_TRANSITION) {
929 /* Look for a role transition rule. */
930 for (roletr = policydb.role_tr; roletr;
931 roletr = roletr->next) {
932 if (roletr->role == scontext->role &&
933 roletr->type == tcontext->type) {
934 /* Use the role transition rule. */
935 newcontext.role = roletr->new_role;
936 break;
937 }
938 }
939 }
940 break;
941 default:
942 break;
943 }
944
945 /* Set the MLS attributes.
946 This is done last because it may allocate memory. */
947 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
948 if (rc)
949 goto out_unlock;
950
951 /* Check the validity of the context. */
952 if (!policydb_context_isvalid(&policydb, &newcontext)) {
953 rc = compute_sid_handle_invalid_context(scontext,
954 tcontext,
955 tclass,
956 &newcontext);
957 if (rc)
958 goto out_unlock;
959 }
960 /* Obtain the sid for the context. */
961 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
962 out_unlock:
963 POLICY_RDUNLOCK;
964 context_destroy(&newcontext);
965 out:
966 return rc;
967 }
968
969 /**
970 * security_transition_sid - Compute the SID for a new subject/object.
971 * @ssid: source security identifier
972 * @tsid: target security identifier
973 * @tclass: target security class
974 * @out_sid: security identifier for new subject/object
975 *
976 * Compute a SID to use for labeling a new subject or object in the
977 * class @tclass based on a SID pair (@ssid, @tsid).
978 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
979 * if insufficient memory is available, or %0 if the new SID was
980 * computed successfully.
981 */
982 int security_transition_sid(u32 ssid,
983 u32 tsid,
984 u16 tclass,
985 u32 *out_sid)
986 {
987 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
988 }
989
990 /**
991 * security_member_sid - Compute the SID for member selection.
992 * @ssid: source security identifier
993 * @tsid: target security identifier
994 * @tclass: target security class
995 * @out_sid: security identifier for selected member
996 *
997 * Compute a SID to use when selecting a member of a polyinstantiated
998 * object of class @tclass based on a SID pair (@ssid, @tsid).
999 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1000 * if insufficient memory is available, or %0 if the SID was
1001 * computed successfully.
1002 */
1003 int security_member_sid(u32 ssid,
1004 u32 tsid,
1005 u16 tclass,
1006 u32 *out_sid)
1007 {
1008 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1009 }
1010
1011 /**
1012 * security_change_sid - Compute the SID for object relabeling.
1013 * @ssid: source security identifier
1014 * @tsid: target security identifier
1015 * @tclass: target security class
1016 * @out_sid: security identifier for selected member
1017 *
1018 * Compute a SID to use for relabeling an object of class @tclass
1019 * based on a SID pair (@ssid, @tsid).
1020 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1021 * if insufficient memory is available, or %0 if the SID was
1022 * computed successfully.
1023 */
1024 int security_change_sid(u32 ssid,
1025 u32 tsid,
1026 u16 tclass,
1027 u32 *out_sid)
1028 {
1029 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1030 }
1031
1032 /*
1033 * Verify that each kernel class that is defined in the
1034 * policy is correct
1035 */
1036 static int validate_classes(struct policydb *p)
1037 {
1038 int i, j;
1039 struct class_datum *cladatum;
1040 struct perm_datum *perdatum;
1041 u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1042 u16 class_val;
1043 const struct selinux_class_perm *kdefs = &selinux_class_perm;
1044 const char *def_class, *def_perm, *pol_class;
1045 struct symtab *perms;
1046
1047 for (i = 1; i < kdefs->cts_len; i++) {
1048 def_class = kdefs->class_to_string[i];
1049 if (i > p->p_classes.nprim) {
1050 printk(KERN_INFO
1051 "security: class %s not defined in policy\n",
1052 def_class);
1053 continue;
1054 }
1055 pol_class = p->p_class_val_to_name[i-1];
1056 if (strcmp(pol_class, def_class)) {
1057 printk(KERN_ERR
1058 "security: class %d is incorrect, found %s but should be %s\n",
1059 i, pol_class, def_class);
1060 return -EINVAL;
1061 }
1062 }
1063 for (i = 0; i < kdefs->av_pts_len; i++) {
1064 class_val = kdefs->av_perm_to_string[i].tclass;
1065 perm_val = kdefs->av_perm_to_string[i].value;
1066 def_perm = kdefs->av_perm_to_string[i].name;
1067 if (class_val > p->p_classes.nprim)
1068 continue;
1069 pol_class = p->p_class_val_to_name[class_val-1];
1070 cladatum = hashtab_search(p->p_classes.table, pol_class);
1071 BUG_ON(!cladatum);
1072 perms = &cladatum->permissions;
1073 nprim = 1 << (perms->nprim - 1);
1074 if (perm_val > nprim) {
1075 printk(KERN_INFO
1076 "security: permission %s in class %s not defined in policy\n",
1077 def_perm, pol_class);
1078 continue;
1079 }
1080 perdatum = hashtab_search(perms->table, def_perm);
1081 if (perdatum == NULL) {
1082 printk(KERN_ERR
1083 "security: permission %s in class %s not found in policy\n",
1084 def_perm, pol_class);
1085 return -EINVAL;
1086 }
1087 pol_val = 1 << (perdatum->value - 1);
1088 if (pol_val != perm_val) {
1089 printk(KERN_ERR
1090 "security: permission %s in class %s has incorrect value\n",
1091 def_perm, pol_class);
1092 return -EINVAL;
1093 }
1094 }
1095 for (i = 0; i < kdefs->av_inherit_len; i++) {
1096 class_val = kdefs->av_inherit[i].tclass;
1097 if (class_val > p->p_classes.nprim)
1098 continue;
1099 pol_class = p->p_class_val_to_name[class_val-1];
1100 cladatum = hashtab_search(p->p_classes.table, pol_class);
1101 BUG_ON(!cladatum);
1102 if (!cladatum->comdatum) {
1103 printk(KERN_ERR
1104 "security: class %s should have an inherits clause but does not\n",
1105 pol_class);
1106 return -EINVAL;
1107 }
1108 tmp = kdefs->av_inherit[i].common_base;
1109 common_pts_len = 0;
1110 while (!(tmp & 0x01)) {
1111 common_pts_len++;
1112 tmp >>= 1;
1113 }
1114 perms = &cladatum->comdatum->permissions;
1115 for (j = 0; j < common_pts_len; j++) {
1116 def_perm = kdefs->av_inherit[i].common_pts[j];
1117 if (j >= perms->nprim) {
1118 printk(KERN_INFO
1119 "security: permission %s in class %s not defined in policy\n",
1120 def_perm, pol_class);
1121 continue;
1122 }
1123 perdatum = hashtab_search(perms->table, def_perm);
1124 if (perdatum == NULL) {
1125 printk(KERN_ERR
1126 "security: permission %s in class %s not found in policy\n",
1127 def_perm, pol_class);
1128 return -EINVAL;
1129 }
1130 if (perdatum->value != j + 1) {
1131 printk(KERN_ERR
1132 "security: permission %s in class %s has incorrect value\n",
1133 def_perm, pol_class);
1134 return -EINVAL;
1135 }
1136 }
1137 }
1138 return 0;
1139 }
1140
1141 /* Clone the SID into the new SID table. */
1142 static int clone_sid(u32 sid,
1143 struct context *context,
1144 void *arg)
1145 {
1146 struct sidtab *s = arg;
1147
1148 return sidtab_insert(s, sid, context);
1149 }
1150
1151 static inline int convert_context_handle_invalid_context(struct context *context)
1152 {
1153 int rc = 0;
1154
1155 if (selinux_enforcing) {
1156 rc = -EINVAL;
1157 } else {
1158 char *s;
1159 u32 len;
1160
1161 context_struct_to_string(context, &s, &len);
1162 printk(KERN_ERR "security: context %s is invalid\n", s);
1163 kfree(s);
1164 }
1165 return rc;
1166 }
1167
1168 struct convert_context_args {
1169 struct policydb *oldp;
1170 struct policydb *newp;
1171 };
1172
1173 /*
1174 * Convert the values in the security context
1175 * structure `c' from the values specified
1176 * in the policy `p->oldp' to the values specified
1177 * in the policy `p->newp'. Verify that the
1178 * context is valid under the new policy.
1179 */
1180 static int convert_context(u32 key,
1181 struct context *c,
1182 void *p)
1183 {
1184 struct convert_context_args *args;
1185 struct context oldc;
1186 struct role_datum *role;
1187 struct type_datum *typdatum;
1188 struct user_datum *usrdatum;
1189 char *s;
1190 u32 len;
1191 int rc;
1192
1193 args = p;
1194
1195 rc = context_cpy(&oldc, c);
1196 if (rc)
1197 goto out;
1198
1199 rc = -EINVAL;
1200
1201 /* Convert the user. */
1202 usrdatum = hashtab_search(args->newp->p_users.table,
1203 args->oldp->p_user_val_to_name[c->user - 1]);
1204 if (!usrdatum) {
1205 goto bad;
1206 }
1207 c->user = usrdatum->value;
1208
1209 /* Convert the role. */
1210 role = hashtab_search(args->newp->p_roles.table,
1211 args->oldp->p_role_val_to_name[c->role - 1]);
1212 if (!role) {
1213 goto bad;
1214 }
1215 c->role = role->value;
1216
1217 /* Convert the type. */
1218 typdatum = hashtab_search(args->newp->p_types.table,
1219 args->oldp->p_type_val_to_name[c->type - 1]);
1220 if (!typdatum) {
1221 goto bad;
1222 }
1223 c->type = typdatum->value;
1224
1225 rc = mls_convert_context(args->oldp, args->newp, c);
1226 if (rc)
1227 goto bad;
1228
1229 /* Check the validity of the new context. */
1230 if (!policydb_context_isvalid(args->newp, c)) {
1231 rc = convert_context_handle_invalid_context(&oldc);
1232 if (rc)
1233 goto bad;
1234 }
1235
1236 context_destroy(&oldc);
1237 out:
1238 return rc;
1239 bad:
1240 context_struct_to_string(&oldc, &s, &len);
1241 context_destroy(&oldc);
1242 printk(KERN_ERR "security: invalidating context %s\n", s);
1243 kfree(s);
1244 goto out;
1245 }
1246
1247 extern void selinux_complete_init(void);
1248
1249 /**
1250 * security_load_policy - Load a security policy configuration.
1251 * @data: binary policy data
1252 * @len: length of data in bytes
1253 *
1254 * Load a new set of security policy configuration data,
1255 * validate it and convert the SID table as necessary.
1256 * This function will flush the access vector cache after
1257 * loading the new policy.
1258 */
1259 int security_load_policy(void *data, size_t len)
1260 {
1261 struct policydb oldpolicydb, newpolicydb;
1262 struct sidtab oldsidtab, newsidtab;
1263 struct convert_context_args args;
1264 u32 seqno;
1265 int rc = 0;
1266 struct policy_file file = { data, len }, *fp = &file;
1267
1268 LOAD_LOCK;
1269
1270 if (!ss_initialized) {
1271 avtab_cache_init();
1272 if (policydb_read(&policydb, fp)) {
1273 LOAD_UNLOCK;
1274 avtab_cache_destroy();
1275 return -EINVAL;
1276 }
1277 if (policydb_load_isids(&policydb, &sidtab)) {
1278 LOAD_UNLOCK;
1279 policydb_destroy(&policydb);
1280 avtab_cache_destroy();
1281 return -EINVAL;
1282 }
1283 /* Verify that the kernel defined classes are correct. */
1284 if (validate_classes(&policydb)) {
1285 printk(KERN_ERR
1286 "security: the definition of a class is incorrect\n");
1287 LOAD_UNLOCK;
1288 sidtab_destroy(&sidtab);
1289 policydb_destroy(&policydb);
1290 avtab_cache_destroy();
1291 return -EINVAL;
1292 }
1293 policydb_loaded_version = policydb.policyvers;
1294 ss_initialized = 1;
1295 seqno = ++latest_granting;
1296 LOAD_UNLOCK;
1297 selinux_complete_init();
1298 avc_ss_reset(seqno);
1299 selnl_notify_policyload(seqno);
1300 selinux_netlbl_cache_invalidate();
1301 return 0;
1302 }
1303
1304 #if 0
1305 sidtab_hash_eval(&sidtab, "sids");
1306 #endif
1307
1308 if (policydb_read(&newpolicydb, fp)) {
1309 LOAD_UNLOCK;
1310 return -EINVAL;
1311 }
1312
1313 sidtab_init(&newsidtab);
1314
1315 /* Verify that the kernel defined classes are correct. */
1316 if (validate_classes(&newpolicydb)) {
1317 printk(KERN_ERR
1318 "security: the definition of a class is incorrect\n");
1319 rc = -EINVAL;
1320 goto err;
1321 }
1322
1323 /* Clone the SID table. */
1324 sidtab_shutdown(&sidtab);
1325 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1326 rc = -ENOMEM;
1327 goto err;
1328 }
1329
1330 /* Convert the internal representations of contexts
1331 in the new SID table and remove invalid SIDs. */
1332 args.oldp = &policydb;
1333 args.newp = &newpolicydb;
1334 sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1335
1336 /* Save the old policydb and SID table to free later. */
1337 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1338 sidtab_set(&oldsidtab, &sidtab);
1339
1340 /* Install the new policydb and SID table. */
1341 POLICY_WRLOCK;
1342 memcpy(&policydb, &newpolicydb, sizeof policydb);
1343 sidtab_set(&sidtab, &newsidtab);
1344 seqno = ++latest_granting;
1345 policydb_loaded_version = policydb.policyvers;
1346 POLICY_WRUNLOCK;
1347 LOAD_UNLOCK;
1348
1349 /* Free the old policydb and SID table. */
1350 policydb_destroy(&oldpolicydb);
1351 sidtab_destroy(&oldsidtab);
1352
1353 avc_ss_reset(seqno);
1354 selnl_notify_policyload(seqno);
1355 selinux_netlbl_cache_invalidate();
1356
1357 return 0;
1358
1359 err:
1360 LOAD_UNLOCK;
1361 sidtab_destroy(&newsidtab);
1362 policydb_destroy(&newpolicydb);
1363 return rc;
1364
1365 }
1366
1367 /**
1368 * security_port_sid - Obtain the SID for a port.
1369 * @domain: communication domain aka address family
1370 * @type: socket type
1371 * @protocol: protocol number
1372 * @port: port number
1373 * @out_sid: security identifier
1374 */
1375 int security_port_sid(u16 domain,
1376 u16 type,
1377 u8 protocol,
1378 u16 port,
1379 u32 *out_sid)
1380 {
1381 struct ocontext *c;
1382 int rc = 0;
1383
1384 POLICY_RDLOCK;
1385
1386 c = policydb.ocontexts[OCON_PORT];
1387 while (c) {
1388 if (c->u.port.protocol == protocol &&
1389 c->u.port.low_port <= port &&
1390 c->u.port.high_port >= port)
1391 break;
1392 c = c->next;
1393 }
1394
1395 if (c) {
1396 if (!c->sid[0]) {
1397 rc = sidtab_context_to_sid(&sidtab,
1398 &c->context[0],
1399 &c->sid[0]);
1400 if (rc)
1401 goto out;
1402 }
1403 *out_sid = c->sid[0];
1404 } else {
1405 *out_sid = SECINITSID_PORT;
1406 }
1407
1408 out:
1409 POLICY_RDUNLOCK;
1410 return rc;
1411 }
1412
1413 /**
1414 * security_netif_sid - Obtain the SID for a network interface.
1415 * @name: interface name
1416 * @if_sid: interface SID
1417 * @msg_sid: default SID for received packets
1418 */
1419 int security_netif_sid(char *name,
1420 u32 *if_sid,
1421 u32 *msg_sid)
1422 {
1423 int rc = 0;
1424 struct ocontext *c;
1425
1426 POLICY_RDLOCK;
1427
1428 c = policydb.ocontexts[OCON_NETIF];
1429 while (c) {
1430 if (strcmp(name, c->u.name) == 0)
1431 break;
1432 c = c->next;
1433 }
1434
1435 if (c) {
1436 if (!c->sid[0] || !c->sid[1]) {
1437 rc = sidtab_context_to_sid(&sidtab,
1438 &c->context[0],
1439 &c->sid[0]);
1440 if (rc)
1441 goto out;
1442 rc = sidtab_context_to_sid(&sidtab,
1443 &c->context[1],
1444 &c->sid[1]);
1445 if (rc)
1446 goto out;
1447 }
1448 *if_sid = c->sid[0];
1449 *msg_sid = c->sid[1];
1450 } else {
1451 *if_sid = SECINITSID_NETIF;
1452 *msg_sid = SECINITSID_NETMSG;
1453 }
1454
1455 out:
1456 POLICY_RDUNLOCK;
1457 return rc;
1458 }
1459
1460 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1461 {
1462 int i, fail = 0;
1463
1464 for(i = 0; i < 4; i++)
1465 if(addr[i] != (input[i] & mask[i])) {
1466 fail = 1;
1467 break;
1468 }
1469
1470 return !fail;
1471 }
1472
1473 /**
1474 * security_node_sid - Obtain the SID for a node (host).
1475 * @domain: communication domain aka address family
1476 * @addrp: address
1477 * @addrlen: address length in bytes
1478 * @out_sid: security identifier
1479 */
1480 int security_node_sid(u16 domain,
1481 void *addrp,
1482 u32 addrlen,
1483 u32 *out_sid)
1484 {
1485 int rc = 0;
1486 struct ocontext *c;
1487
1488 POLICY_RDLOCK;
1489
1490 switch (domain) {
1491 case AF_INET: {
1492 u32 addr;
1493
1494 if (addrlen != sizeof(u32)) {
1495 rc = -EINVAL;
1496 goto out;
1497 }
1498
1499 addr = *((u32 *)addrp);
1500
1501 c = policydb.ocontexts[OCON_NODE];
1502 while (c) {
1503 if (c->u.node.addr == (addr & c->u.node.mask))
1504 break;
1505 c = c->next;
1506 }
1507 break;
1508 }
1509
1510 case AF_INET6:
1511 if (addrlen != sizeof(u64) * 2) {
1512 rc = -EINVAL;
1513 goto out;
1514 }
1515 c = policydb.ocontexts[OCON_NODE6];
1516 while (c) {
1517 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1518 c->u.node6.mask))
1519 break;
1520 c = c->next;
1521 }
1522 break;
1523
1524 default:
1525 *out_sid = SECINITSID_NODE;
1526 goto out;
1527 }
1528
1529 if (c) {
1530 if (!c->sid[0]) {
1531 rc = sidtab_context_to_sid(&sidtab,
1532 &c->context[0],
1533 &c->sid[0]);
1534 if (rc)
1535 goto out;
1536 }
1537 *out_sid = c->sid[0];
1538 } else {
1539 *out_sid = SECINITSID_NODE;
1540 }
1541
1542 out:
1543 POLICY_RDUNLOCK;
1544 return rc;
1545 }
1546
1547 #define SIDS_NEL 25
1548
1549 /**
1550 * security_get_user_sids - Obtain reachable SIDs for a user.
1551 * @fromsid: starting SID
1552 * @username: username
1553 * @sids: array of reachable SIDs for user
1554 * @nel: number of elements in @sids
1555 *
1556 * Generate the set of SIDs for legal security contexts
1557 * for a given user that can be reached by @fromsid.
1558 * Set *@sids to point to a dynamically allocated
1559 * array containing the set of SIDs. Set *@nel to the
1560 * number of elements in the array.
1561 */
1562
1563 int security_get_user_sids(u32 fromsid,
1564 char *username,
1565 u32 **sids,
1566 u32 *nel)
1567 {
1568 struct context *fromcon, usercon;
1569 u32 *mysids, *mysids2, sid;
1570 u32 mynel = 0, maxnel = SIDS_NEL;
1571 struct user_datum *user;
1572 struct role_datum *role;
1573 struct av_decision avd;
1574 struct ebitmap_node *rnode, *tnode;
1575 int rc = 0, i, j;
1576
1577 if (!ss_initialized) {
1578 *sids = NULL;
1579 *nel = 0;
1580 goto out;
1581 }
1582
1583 POLICY_RDLOCK;
1584
1585 fromcon = sidtab_search(&sidtab, fromsid);
1586 if (!fromcon) {
1587 rc = -EINVAL;
1588 goto out_unlock;
1589 }
1590
1591 user = hashtab_search(policydb.p_users.table, username);
1592 if (!user) {
1593 rc = -EINVAL;
1594 goto out_unlock;
1595 }
1596 usercon.user = user->value;
1597
1598 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1599 if (!mysids) {
1600 rc = -ENOMEM;
1601 goto out_unlock;
1602 }
1603
1604 ebitmap_for_each_bit(&user->roles, rnode, i) {
1605 if (!ebitmap_node_get_bit(rnode, i))
1606 continue;
1607 role = policydb.role_val_to_struct[i];
1608 usercon.role = i+1;
1609 ebitmap_for_each_bit(&role->types, tnode, j) {
1610 if (!ebitmap_node_get_bit(tnode, j))
1611 continue;
1612 usercon.type = j+1;
1613
1614 if (mls_setup_user_range(fromcon, user, &usercon))
1615 continue;
1616
1617 rc = context_struct_compute_av(fromcon, &usercon,
1618 SECCLASS_PROCESS,
1619 PROCESS__TRANSITION,
1620 &avd);
1621 if (rc || !(avd.allowed & PROCESS__TRANSITION))
1622 continue;
1623 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1624 if (rc) {
1625 kfree(mysids);
1626 goto out_unlock;
1627 }
1628 if (mynel < maxnel) {
1629 mysids[mynel++] = sid;
1630 } else {
1631 maxnel += SIDS_NEL;
1632 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1633 if (!mysids2) {
1634 rc = -ENOMEM;
1635 kfree(mysids);
1636 goto out_unlock;
1637 }
1638 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1639 kfree(mysids);
1640 mysids = mysids2;
1641 mysids[mynel++] = sid;
1642 }
1643 }
1644 }
1645
1646 *sids = mysids;
1647 *nel = mynel;
1648
1649 out_unlock:
1650 POLICY_RDUNLOCK;
1651 out:
1652 return rc;
1653 }
1654
1655 /**
1656 * security_genfs_sid - Obtain a SID for a file in a filesystem
1657 * @fstype: filesystem type
1658 * @path: path from root of mount
1659 * @sclass: file security class
1660 * @sid: SID for path
1661 *
1662 * Obtain a SID to use for a file in a filesystem that
1663 * cannot support xattr or use a fixed labeling behavior like
1664 * transition SIDs or task SIDs.
1665 */
1666 int security_genfs_sid(const char *fstype,
1667 char *path,
1668 u16 sclass,
1669 u32 *sid)
1670 {
1671 int len;
1672 struct genfs *genfs;
1673 struct ocontext *c;
1674 int rc = 0, cmp = 0;
1675
1676 POLICY_RDLOCK;
1677
1678 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1679 cmp = strcmp(fstype, genfs->fstype);
1680 if (cmp <= 0)
1681 break;
1682 }
1683
1684 if (!genfs || cmp) {
1685 *sid = SECINITSID_UNLABELED;
1686 rc = -ENOENT;
1687 goto out;
1688 }
1689
1690 for (c = genfs->head; c; c = c->next) {
1691 len = strlen(c->u.name);
1692 if ((!c->v.sclass || sclass == c->v.sclass) &&
1693 (strncmp(c->u.name, path, len) == 0))
1694 break;
1695 }
1696
1697 if (!c) {
1698 *sid = SECINITSID_UNLABELED;
1699 rc = -ENOENT;
1700 goto out;
1701 }
1702
1703 if (!c->sid[0]) {
1704 rc = sidtab_context_to_sid(&sidtab,
1705 &c->context[0],
1706 &c->sid[0]);
1707 if (rc)
1708 goto out;
1709 }
1710
1711 *sid = c->sid[0];
1712 out:
1713 POLICY_RDUNLOCK;
1714 return rc;
1715 }
1716
1717 /**
1718 * security_fs_use - Determine how to handle labeling for a filesystem.
1719 * @fstype: filesystem type
1720 * @behavior: labeling behavior
1721 * @sid: SID for filesystem (superblock)
1722 */
1723 int security_fs_use(
1724 const char *fstype,
1725 unsigned int *behavior,
1726 u32 *sid)
1727 {
1728 int rc = 0;
1729 struct ocontext *c;
1730
1731 POLICY_RDLOCK;
1732
1733 c = policydb.ocontexts[OCON_FSUSE];
1734 while (c) {
1735 if (strcmp(fstype, c->u.name) == 0)
1736 break;
1737 c = c->next;
1738 }
1739
1740 if (c) {
1741 *behavior = c->v.behavior;
1742 if (!c->sid[0]) {
1743 rc = sidtab_context_to_sid(&sidtab,
1744 &c->context[0],
1745 &c->sid[0]);
1746 if (rc)
1747 goto out;
1748 }
1749 *sid = c->sid[0];
1750 } else {
1751 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1752 if (rc) {
1753 *behavior = SECURITY_FS_USE_NONE;
1754 rc = 0;
1755 } else {
1756 *behavior = SECURITY_FS_USE_GENFS;
1757 }
1758 }
1759
1760 out:
1761 POLICY_RDUNLOCK;
1762 return rc;
1763 }
1764
1765 int security_get_bools(int *len, char ***names, int **values)
1766 {
1767 int i, rc = -ENOMEM;
1768
1769 POLICY_RDLOCK;
1770 *names = NULL;
1771 *values = NULL;
1772
1773 *len = policydb.p_bools.nprim;
1774 if (!*len) {
1775 rc = 0;
1776 goto out;
1777 }
1778
1779 *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1780 if (!*names)
1781 goto err;
1782
1783 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1784 if (!*values)
1785 goto err;
1786
1787 for (i = 0; i < *len; i++) {
1788 size_t name_len;
1789 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1790 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1791 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1792 if (!(*names)[i])
1793 goto err;
1794 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1795 (*names)[i][name_len - 1] = 0;
1796 }
1797 rc = 0;
1798 out:
1799 POLICY_RDUNLOCK;
1800 return rc;
1801 err:
1802 if (*names) {
1803 for (i = 0; i < *len; i++)
1804 kfree((*names)[i]);
1805 }
1806 kfree(*values);
1807 goto out;
1808 }
1809
1810
1811 int security_set_bools(int len, int *values)
1812 {
1813 int i, rc = 0;
1814 int lenp, seqno = 0;
1815 struct cond_node *cur;
1816
1817 POLICY_WRLOCK;
1818
1819 lenp = policydb.p_bools.nprim;
1820 if (len != lenp) {
1821 rc = -EFAULT;
1822 goto out;
1823 }
1824
1825 for (i = 0; i < len; i++) {
1826 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1827 audit_log(current->audit_context, GFP_ATOMIC,
1828 AUDIT_MAC_CONFIG_CHANGE,
1829 "bool=%s val=%d old_val=%d auid=%u",
1830 policydb.p_bool_val_to_name[i],
1831 !!values[i],
1832 policydb.bool_val_to_struct[i]->state,
1833 audit_get_loginuid(current->audit_context));
1834 }
1835 if (values[i]) {
1836 policydb.bool_val_to_struct[i]->state = 1;
1837 } else {
1838 policydb.bool_val_to_struct[i]->state = 0;
1839 }
1840 }
1841
1842 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1843 rc = evaluate_cond_node(&policydb, cur);
1844 if (rc)
1845 goto out;
1846 }
1847
1848 seqno = ++latest_granting;
1849
1850 out:
1851 POLICY_WRUNLOCK;
1852 if (!rc) {
1853 avc_ss_reset(seqno);
1854 selnl_notify_policyload(seqno);
1855 }
1856 return rc;
1857 }
1858
1859 int security_get_bool_value(int bool)
1860 {
1861 int rc = 0;
1862 int len;
1863
1864 POLICY_RDLOCK;
1865
1866 len = policydb.p_bools.nprim;
1867 if (bool >= len) {
1868 rc = -EFAULT;
1869 goto out;
1870 }
1871
1872 rc = policydb.bool_val_to_struct[bool]->state;
1873 out:
1874 POLICY_RDUNLOCK;
1875 return rc;
1876 }
1877
1878 /*
1879 * security_sid_mls_copy() - computes a new sid based on the given
1880 * sid and the mls portion of mls_sid.
1881 */
1882 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1883 {
1884 struct context *context1;
1885 struct context *context2;
1886 struct context newcon;
1887 char *s;
1888 u32 len;
1889 int rc = 0;
1890
1891 if (!ss_initialized || !selinux_mls_enabled) {
1892 *new_sid = sid;
1893 goto out;
1894 }
1895
1896 context_init(&newcon);
1897
1898 POLICY_RDLOCK;
1899 context1 = sidtab_search(&sidtab, sid);
1900 if (!context1) {
1901 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1902 "%d\n", sid);
1903 rc = -EINVAL;
1904 goto out_unlock;
1905 }
1906
1907 context2 = sidtab_search(&sidtab, mls_sid);
1908 if (!context2) {
1909 printk(KERN_ERR "security_sid_mls_copy: unrecognized SID "
1910 "%d\n", mls_sid);
1911 rc = -EINVAL;
1912 goto out_unlock;
1913 }
1914
1915 newcon.user = context1->user;
1916 newcon.role = context1->role;
1917 newcon.type = context1->type;
1918 rc = mls_copy_context(&newcon, context2);
1919 if (rc)
1920 goto out_unlock;
1921
1922
1923 /* Check the validity of the new context. */
1924 if (!policydb_context_isvalid(&policydb, &newcon)) {
1925 rc = convert_context_handle_invalid_context(&newcon);
1926 if (rc)
1927 goto bad;
1928 }
1929
1930 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
1931 goto out_unlock;
1932
1933 bad:
1934 if (!context_struct_to_string(&newcon, &s, &len)) {
1935 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1936 "security_sid_mls_copy: invalid context %s", s);
1937 kfree(s);
1938 }
1939
1940 out_unlock:
1941 POLICY_RDUNLOCK;
1942 context_destroy(&newcon);
1943 out:
1944 return rc;
1945 }
1946
1947 struct selinux_audit_rule {
1948 u32 au_seqno;
1949 struct context au_ctxt;
1950 };
1951
1952 void selinux_audit_rule_free(struct selinux_audit_rule *rule)
1953 {
1954 if (rule) {
1955 context_destroy(&rule->au_ctxt);
1956 kfree(rule);
1957 }
1958 }
1959
1960 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
1961 struct selinux_audit_rule **rule)
1962 {
1963 struct selinux_audit_rule *tmprule;
1964 struct role_datum *roledatum;
1965 struct type_datum *typedatum;
1966 struct user_datum *userdatum;
1967 int rc = 0;
1968
1969 *rule = NULL;
1970
1971 if (!ss_initialized)
1972 return -ENOTSUPP;
1973
1974 switch (field) {
1975 case AUDIT_SUBJ_USER:
1976 case AUDIT_SUBJ_ROLE:
1977 case AUDIT_SUBJ_TYPE:
1978 case AUDIT_OBJ_USER:
1979 case AUDIT_OBJ_ROLE:
1980 case AUDIT_OBJ_TYPE:
1981 /* only 'equals' and 'not equals' fit user, role, and type */
1982 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
1983 return -EINVAL;
1984 break;
1985 case AUDIT_SUBJ_SEN:
1986 case AUDIT_SUBJ_CLR:
1987 case AUDIT_OBJ_LEV_LOW:
1988 case AUDIT_OBJ_LEV_HIGH:
1989 /* we do not allow a range, indicated by the presense of '-' */
1990 if (strchr(rulestr, '-'))
1991 return -EINVAL;
1992 break;
1993 default:
1994 /* only the above fields are valid */
1995 return -EINVAL;
1996 }
1997
1998 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
1999 if (!tmprule)
2000 return -ENOMEM;
2001
2002 context_init(&tmprule->au_ctxt);
2003
2004 POLICY_RDLOCK;
2005
2006 tmprule->au_seqno = latest_granting;
2007
2008 switch (field) {
2009 case AUDIT_SUBJ_USER:
2010 case AUDIT_OBJ_USER:
2011 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2012 if (!userdatum)
2013 rc = -EINVAL;
2014 else
2015 tmprule->au_ctxt.user = userdatum->value;
2016 break;
2017 case AUDIT_SUBJ_ROLE:
2018 case AUDIT_OBJ_ROLE:
2019 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2020 if (!roledatum)
2021 rc = -EINVAL;
2022 else
2023 tmprule->au_ctxt.role = roledatum->value;
2024 break;
2025 case AUDIT_SUBJ_TYPE:
2026 case AUDIT_OBJ_TYPE:
2027 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2028 if (!typedatum)
2029 rc = -EINVAL;
2030 else
2031 tmprule->au_ctxt.type = typedatum->value;
2032 break;
2033 case AUDIT_SUBJ_SEN:
2034 case AUDIT_SUBJ_CLR:
2035 case AUDIT_OBJ_LEV_LOW:
2036 case AUDIT_OBJ_LEV_HIGH:
2037 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2038 break;
2039 }
2040
2041 POLICY_RDUNLOCK;
2042
2043 if (rc) {
2044 selinux_audit_rule_free(tmprule);
2045 tmprule = NULL;
2046 }
2047
2048 *rule = tmprule;
2049
2050 return rc;
2051 }
2052
2053 int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2054 struct selinux_audit_rule *rule,
2055 struct audit_context *actx)
2056 {
2057 struct context *ctxt;
2058 struct mls_level *level;
2059 int match = 0;
2060
2061 if (!rule) {
2062 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2063 "selinux_audit_rule_match: missing rule\n");
2064 return -ENOENT;
2065 }
2066
2067 POLICY_RDLOCK;
2068
2069 if (rule->au_seqno < latest_granting) {
2070 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2071 "selinux_audit_rule_match: stale rule\n");
2072 match = -ESTALE;
2073 goto out;
2074 }
2075
2076 ctxt = sidtab_search(&sidtab, sid);
2077 if (!ctxt) {
2078 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2079 "selinux_audit_rule_match: unrecognized SID %d\n",
2080 sid);
2081 match = -ENOENT;
2082 goto out;
2083 }
2084
2085 /* a field/op pair that is not caught here will simply fall through
2086 without a match */
2087 switch (field) {
2088 case AUDIT_SUBJ_USER:
2089 case AUDIT_OBJ_USER:
2090 switch (op) {
2091 case AUDIT_EQUAL:
2092 match = (ctxt->user == rule->au_ctxt.user);
2093 break;
2094 case AUDIT_NOT_EQUAL:
2095 match = (ctxt->user != rule->au_ctxt.user);
2096 break;
2097 }
2098 break;
2099 case AUDIT_SUBJ_ROLE:
2100 case AUDIT_OBJ_ROLE:
2101 switch (op) {
2102 case AUDIT_EQUAL:
2103 match = (ctxt->role == rule->au_ctxt.role);
2104 break;
2105 case AUDIT_NOT_EQUAL:
2106 match = (ctxt->role != rule->au_ctxt.role);
2107 break;
2108 }
2109 break;
2110 case AUDIT_SUBJ_TYPE:
2111 case AUDIT_OBJ_TYPE:
2112 switch (op) {
2113 case AUDIT_EQUAL:
2114 match = (ctxt->type == rule->au_ctxt.type);
2115 break;
2116 case AUDIT_NOT_EQUAL:
2117 match = (ctxt->type != rule->au_ctxt.type);
2118 break;
2119 }
2120 break;
2121 case AUDIT_SUBJ_SEN:
2122 case AUDIT_SUBJ_CLR:
2123 case AUDIT_OBJ_LEV_LOW:
2124 case AUDIT_OBJ_LEV_HIGH:
2125 level = ((field == AUDIT_SUBJ_SEN ||
2126 field == AUDIT_OBJ_LEV_LOW) ?
2127 &ctxt->range.level[0] : &ctxt->range.level[1]);
2128 switch (op) {
2129 case AUDIT_EQUAL:
2130 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2131 level);
2132 break;
2133 case AUDIT_NOT_EQUAL:
2134 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2135 level);
2136 break;
2137 case AUDIT_LESS_THAN:
2138 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2139 level) &&
2140 !mls_level_eq(&rule->au_ctxt.range.level[0],
2141 level));
2142 break;
2143 case AUDIT_LESS_THAN_OR_EQUAL:
2144 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2145 level);
2146 break;
2147 case AUDIT_GREATER_THAN:
2148 match = (mls_level_dom(level,
2149 &rule->au_ctxt.range.level[0]) &&
2150 !mls_level_eq(level,
2151 &rule->au_ctxt.range.level[0]));
2152 break;
2153 case AUDIT_GREATER_THAN_OR_EQUAL:
2154 match = mls_level_dom(level,
2155 &rule->au_ctxt.range.level[0]);
2156 break;
2157 }
2158 }
2159
2160 out:
2161 POLICY_RDUNLOCK;
2162 return match;
2163 }
2164
2165 static int (*aurule_callback)(void) = NULL;
2166
2167 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2168 u16 class, u32 perms, u32 *retained)
2169 {
2170 int err = 0;
2171
2172 if (event == AVC_CALLBACK_RESET && aurule_callback)
2173 err = aurule_callback();
2174 return err;
2175 }
2176
2177 static int __init aurule_init(void)
2178 {
2179 int err;
2180
2181 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2182 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2183 if (err)
2184 panic("avc_add_callback() failed, error %d\n", err);
2185
2186 return err;
2187 }
2188 __initcall(aurule_init);
2189
2190 void selinux_audit_set_callback(int (*callback)(void))
2191 {
2192 aurule_callback = callback;
2193 }
2194
2195 /**
2196 * security_skb_extlbl_sid - Determine the external label of a packet
2197 * @skb: the packet
2198 * @base_sid: the SELinux SID to use as a context for MLS only external labels
2199 * @sid: the packet's SID
2200 *
2201 * Description:
2202 * Check the various different forms of external packet labeling and determine
2203 * the external SID for the packet.
2204 *
2205 */
2206 void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid)
2207 {
2208 u32 xfrm_sid;
2209 u32 nlbl_sid;
2210
2211 selinux_skb_xfrm_sid(skb, &xfrm_sid);
2212 if (selinux_netlbl_skbuff_getsid(skb,
2213 (xfrm_sid == SECSID_NULL ?
2214 base_sid : xfrm_sid),
2215 &nlbl_sid) != 0)
2216 nlbl_sid = SECSID_NULL;
2217
2218 *sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
2219 }
2220
2221 #ifdef CONFIG_NETLABEL
2222 /*
2223 * This is the structure we store inside the NetLabel cache block.
2224 */
2225 #define NETLBL_CACHE(x) ((struct netlbl_cache *)(x))
2226 #define NETLBL_CACHE_T_NONE 0
2227 #define NETLBL_CACHE_T_SID 1
2228 #define NETLBL_CACHE_T_MLS 2
2229 struct netlbl_cache {
2230 u32 type;
2231 union {
2232 u32 sid;
2233 struct mls_range mls_label;
2234 } data;
2235 };
2236
2237 /**
2238 * selinux_netlbl_cache_free - Free the NetLabel cached data
2239 * @data: the data to free
2240 *
2241 * Description:
2242 * This function is intended to be used as the free() callback inside the
2243 * netlbl_lsm_cache structure.
2244 *
2245 */
2246 static void selinux_netlbl_cache_free(const void *data)
2247 {
2248 struct netlbl_cache *cache;
2249
2250 if (data == NULL)
2251 return;
2252
2253 cache = NETLBL_CACHE(data);
2254 switch (cache->type) {
2255 case NETLBL_CACHE_T_MLS:
2256 ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2257 break;
2258 }
2259 kfree(data);
2260 }
2261
2262 /**
2263 * selinux_netlbl_cache_add - Add an entry to the NetLabel cache
2264 * @skb: the packet
2265 * @ctx: the SELinux context
2266 *
2267 * Description:
2268 * Attempt to cache the context in @ctx, which was derived from the packet in
2269 * @skb, in the NetLabel subsystem cache.
2270 *
2271 */
2272 static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx)
2273 {
2274 struct netlbl_cache *cache = NULL;
2275 struct netlbl_lsm_secattr secattr;
2276
2277 netlbl_secattr_init(&secattr);
2278 secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2279 if (secattr.cache == NULL)
2280 goto netlbl_cache_add_return;
2281
2282 cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2283 if (cache == NULL)
2284 goto netlbl_cache_add_return;
2285
2286 cache->type = NETLBL_CACHE_T_MLS;
2287 if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2288 &ctx->range.level[0].cat) != 0)
2289 goto netlbl_cache_add_return;
2290 cache->data.mls_label.level[1].cat.highbit =
2291 cache->data.mls_label.level[0].cat.highbit;
2292 cache->data.mls_label.level[1].cat.node =
2293 cache->data.mls_label.level[0].cat.node;
2294 cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2295 cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2296
2297 secattr.cache->free = selinux_netlbl_cache_free;
2298 secattr.cache->data = (void *)cache;
2299 secattr.flags = NETLBL_SECATTR_CACHE;
2300
2301 netlbl_cache_add(skb, &secattr);
2302
2303 netlbl_cache_add_return:
2304 netlbl_secattr_destroy(&secattr);
2305 }
2306
2307 /**
2308 * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
2309 *
2310 * Description:
2311 * Invalidate the NetLabel security attribute mapping cache.
2312 *
2313 */
2314 void selinux_netlbl_cache_invalidate(void)
2315 {
2316 netlbl_cache_invalidate();
2317 }
2318
2319 /**
2320 * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2321 * @skb: the network packet
2322 * @secattr: the NetLabel packet security attributes
2323 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2324 * @sid: the SELinux SID
2325 *
2326 * Description:
2327 * Convert the given NetLabel packet security attributes in @secattr into a
2328 * SELinux SID. If the @secattr field does not contain a full SELinux
2329 * SID/context then use the context in @base_sid as the foundation. If @skb
2330 * is not NULL attempt to cache as much data as possibile. Returns zero on
2331 * success, negative values on failure.
2332 *
2333 */
2334 static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
2335 struct netlbl_lsm_secattr *secattr,
2336 u32 base_sid,
2337 u32 *sid)
2338 {
2339 int rc = -EIDRM;
2340 struct context *ctx;
2341 struct context ctx_new;
2342 struct netlbl_cache *cache;
2343
2344 POLICY_RDLOCK;
2345
2346 if (secattr->flags & NETLBL_SECATTR_CACHE) {
2347 cache = NETLBL_CACHE(secattr->cache->data);
2348 switch (cache->type) {
2349 case NETLBL_CACHE_T_SID:
2350 *sid = cache->data.sid;
2351 rc = 0;
2352 break;
2353 case NETLBL_CACHE_T_MLS:
2354 ctx = sidtab_search(&sidtab, base_sid);
2355 if (ctx == NULL)
2356 goto netlbl_secattr_to_sid_return;
2357
2358 ctx_new.user = ctx->user;
2359 ctx_new.role = ctx->role;
2360 ctx_new.type = ctx->type;
2361 ctx_new.range.level[0].sens =
2362 cache->data.mls_label.level[0].sens;
2363 ctx_new.range.level[0].cat.highbit =
2364 cache->data.mls_label.level[0].cat.highbit;
2365 ctx_new.range.level[0].cat.node =
2366 cache->data.mls_label.level[0].cat.node;
2367 ctx_new.range.level[1].sens =
2368 cache->data.mls_label.level[1].sens;
2369 ctx_new.range.level[1].cat.highbit =
2370 cache->data.mls_label.level[1].cat.highbit;
2371 ctx_new.range.level[1].cat.node =
2372 cache->data.mls_label.level[1].cat.node;
2373
2374 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2375 break;
2376 default:
2377 goto netlbl_secattr_to_sid_return;
2378 }
2379 } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2380 ctx = sidtab_search(&sidtab, base_sid);
2381 if (ctx == NULL)
2382 goto netlbl_secattr_to_sid_return;
2383
2384 ctx_new.user = ctx->user;
2385 ctx_new.role = ctx->role;
2386 ctx_new.type = ctx->type;
2387 mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl);
2388 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2389 if (mls_import_cat(&ctx_new,
2390 secattr->mls_cat,
2391 secattr->mls_cat_len,
2392 NULL,
2393 0) != 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 mls_export_lvl(ctx, &secattr.mls_lvl, NULL);
2490 rc = mls_export_cat(ctx,
2491 &secattr.mls_cat,
2492 &secattr.mls_cat_len,
2493 NULL,
2494 NULL);
2495 if (rc != 0)
2496 goto netlbl_socket_setsid_return;
2497
2498 secattr.flags |= NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
2499 if (secattr.mls_cat)
2500 secattr.flags |= NETLBL_SECATTR_MLS_CAT;
2501
2502 rc = netlbl_socket_setattr(sock, &secattr);
2503 if (rc == 0) {
2504 spin_lock(&sksec->nlbl_lock);
2505 sksec->nlbl_state = NLBL_LABELED;
2506 spin_unlock(&sksec->nlbl_lock);
2507 }
2508
2509 netlbl_socket_setsid_return:
2510 POLICY_RDUNLOCK;
2511 netlbl_secattr_destroy(&secattr);
2512 return rc;
2513 }
2514
2515 /**
2516 * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
2517 * @ssec: the sk_security_struct
2518 * @family: the socket family
2519 *
2520 * Description:
2521 * Called when the NetLabel state of a sk_security_struct needs to be reset.
2522 * The caller is responsibile for all the NetLabel sk_security_struct locking.
2523 *
2524 */
2525 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
2526 int family)
2527 {
2528 if (family == PF_INET)
2529 ssec->nlbl_state = NLBL_REQUIRE;
2530 else
2531 ssec->nlbl_state = NLBL_UNSET;
2532 }
2533
2534 /**
2535 * selinux_netlbl_sk_security_init - Setup the NetLabel fields
2536 * @ssec: the sk_security_struct
2537 * @family: the socket family
2538 *
2539 * Description:
2540 * Called when a new sk_security_struct is allocated to initialize the NetLabel
2541 * fields.
2542 *
2543 */
2544 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
2545 int family)
2546 {
2547 /* No locking needed, we are the only one who has access to ssec */
2548 selinux_netlbl_sk_security_reset(ssec, family);
2549 spin_lock_init(&ssec->nlbl_lock);
2550 }
2551
2552 /**
2553 * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
2554 * @ssec: the original sk_security_struct
2555 * @newssec: the cloned sk_security_struct
2556 *
2557 * Description:
2558 * Clone the NetLabel specific sk_security_struct fields from @ssec to
2559 * @newssec.
2560 *
2561 */
2562 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
2563 struct sk_security_struct *newssec)
2564 {
2565 /* We don't need to take newssec->nlbl_lock because we are the only
2566 * thread with access to newssec, but we do need to take the RCU read
2567 * lock as other threads could have access to ssec */
2568 rcu_read_lock();
2569 selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
2570 newssec->sclass = ssec->sclass;
2571 rcu_read_unlock();
2572 }
2573
2574 /**
2575 * selinux_netlbl_socket_post_create - Label a socket using NetLabel
2576 * @sock: the socket to label
2577 *
2578 * Description:
2579 * Attempt to label a socket using the NetLabel mechanism using the given
2580 * SID. Returns zero values on success, negative values on failure.
2581 *
2582 */
2583 int selinux_netlbl_socket_post_create(struct socket *sock)
2584 {
2585 int rc = 0;
2586 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2587 struct sk_security_struct *sksec = sock->sk->sk_security;
2588
2589 sksec->sclass = isec->sclass;
2590
2591 rcu_read_lock();
2592 if (sksec->nlbl_state == NLBL_REQUIRE)
2593 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2594 rcu_read_unlock();
2595
2596 return rc;
2597 }
2598
2599 /**
2600 * selinux_netlbl_sock_graft - Netlabel the new socket
2601 * @sk: the new connection
2602 * @sock: the new socket
2603 *
2604 * Description:
2605 * The connection represented by @sk is being grafted onto @sock so set the
2606 * socket's NetLabel to match the SID of @sk.
2607 *
2608 */
2609 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
2610 {
2611 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2612 struct sk_security_struct *sksec = sk->sk_security;
2613 struct netlbl_lsm_secattr secattr;
2614 u32 nlbl_peer_sid;
2615
2616 sksec->sclass = isec->sclass;
2617
2618 rcu_read_lock();
2619
2620 if (sksec->nlbl_state != NLBL_REQUIRE) {
2621 rcu_read_unlock();
2622 return;
2623 }
2624
2625 netlbl_secattr_init(&secattr);
2626 if (netlbl_sock_getattr(sk, &secattr) == 0 &&
2627 secattr.flags != NETLBL_SECATTR_NONE &&
2628 selinux_netlbl_secattr_to_sid(NULL,
2629 &secattr,
2630 SECINITSID_UNLABELED,
2631 &nlbl_peer_sid) == 0)
2632 sksec->peer_sid = nlbl_peer_sid;
2633 netlbl_secattr_destroy(&secattr);
2634
2635 /* Try to set the NetLabel on the socket to save time later, if we fail
2636 * here we will pick up the pieces in later calls to
2637 * selinux_netlbl_inode_permission(). */
2638 selinux_netlbl_socket_setsid(sock, sksec->sid);
2639
2640 rcu_read_unlock();
2641 }
2642
2643 /**
2644 * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
2645 * @inode: the file descriptor's inode
2646 * @mask: the permission mask
2647 *
2648 * Description:
2649 * Looks at a file's inode and if it is marked as a socket protected by
2650 * NetLabel then verify that the socket has been labeled, if not try to label
2651 * the socket now with the inode's SID. Returns zero on success, negative
2652 * values on failure.
2653 *
2654 */
2655 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
2656 {
2657 int rc;
2658 struct sk_security_struct *sksec;
2659 struct socket *sock;
2660
2661 if (!S_ISSOCK(inode->i_mode) ||
2662 ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
2663 return 0;
2664 sock = SOCKET_I(inode);
2665 sksec = sock->sk->sk_security;
2666
2667 rcu_read_lock();
2668 if (sksec->nlbl_state != NLBL_REQUIRE) {
2669 rcu_read_unlock();
2670 return 0;
2671 }
2672 lock_sock(sock->sk);
2673 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2674 release_sock(sock->sk);
2675 rcu_read_unlock();
2676
2677 return rc;
2678 }
2679
2680 /**
2681 * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
2682 * @sksec: the sock's sk_security_struct
2683 * @skb: the packet
2684 * @ad: the audit data
2685 *
2686 * Description:
2687 * Fetch the NetLabel security attributes from @skb and perform an access check
2688 * against the receiving socket. Returns zero on success, negative values on
2689 * error.
2690 *
2691 */
2692 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
2693 struct sk_buff *skb,
2694 struct avc_audit_data *ad)
2695 {
2696 int rc;
2697 u32 netlbl_sid;
2698 u32 recv_perm;
2699
2700 rc = selinux_netlbl_skbuff_getsid(skb,
2701 SECINITSID_UNLABELED,
2702 &netlbl_sid);
2703 if (rc != 0)
2704 return rc;
2705
2706 if (netlbl_sid == SECSID_NULL)
2707 return 0;
2708
2709 switch (sksec->sclass) {
2710 case SECCLASS_UDP_SOCKET:
2711 recv_perm = UDP_SOCKET__RECVFROM;
2712 break;
2713 case SECCLASS_TCP_SOCKET:
2714 recv_perm = TCP_SOCKET__RECVFROM;
2715 break;
2716 default:
2717 recv_perm = RAWIP_SOCKET__RECVFROM;
2718 }
2719
2720 rc = avc_has_perm(sksec->sid,
2721 netlbl_sid,
2722 sksec->sclass,
2723 recv_perm,
2724 ad);
2725 if (rc == 0)
2726 return 0;
2727
2728 netlbl_skbuff_err(skb, rc);
2729 return rc;
2730 }
2731
2732 /**
2733 * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
2734 * @sock: the socket
2735 * @level: the socket level or protocol
2736 * @optname: the socket option name
2737 *
2738 * Description:
2739 * Check the setsockopt() call and if the user is trying to replace the IP
2740 * options on a socket and a NetLabel is in place for the socket deny the
2741 * access; otherwise allow the access. Returns zero when the access is
2742 * allowed, -EACCES when denied, and other negative values on error.
2743 *
2744 */
2745 int selinux_netlbl_socket_setsockopt(struct socket *sock,
2746 int level,
2747 int optname)
2748 {
2749 int rc = 0;
2750 struct sk_security_struct *sksec = sock->sk->sk_security;
2751 struct netlbl_lsm_secattr secattr;
2752
2753 rcu_read_lock();
2754 if (level == IPPROTO_IP && optname == IP_OPTIONS &&
2755 sksec->nlbl_state == NLBL_LABELED) {
2756 netlbl_secattr_init(&secattr);
2757 rc = netlbl_socket_getattr(sock, &secattr);
2758 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2759 rc = -EACCES;
2760 netlbl_secattr_destroy(&secattr);
2761 }
2762 rcu_read_unlock();
2763
2764 return rc;
2765 }
2766 #endif /* CONFIG_NETLABEL */
linux v2.6.22.y-op