blob: 61492485de84503f4ba87fff57326a3efde187a9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
11 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
12 *
13 * Added conditional policy language extensions
14 *
15 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
17 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation, version 2.
21 */
22#include <linux/kernel.h>
23#include <linux/slab.h>
24#include <linux/string.h>
25#include <linux/spinlock.h>
26#include <linux/errno.h>
27#include <linux/in.h>
28#include <linux/sched.h>
29#include <linux/audit.h>
Ingo Molnarbb003072006-03-22 00:09:14 -080030#include <linux/mutex.h>
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include "flask.h"
33#include "avc.h"
34#include "avc_ss.h"
35#include "security.h"
36#include "context.h"
37#include "policydb.h"
38#include "sidtab.h"
39#include "services.h"
40#include "conditional.h"
41#include "mls.h"
42
43extern void selnl_notify_policyload(u32 seqno);
44unsigned int policydb_loaded_version;
45
46static DEFINE_RWLOCK(policy_rwlock);
47#define POLICY_RDLOCK read_lock(&policy_rwlock)
48#define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
49#define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
50#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
51
Ingo Molnarbb003072006-03-22 00:09:14 -080052static DEFINE_MUTEX(load_mutex);
53#define LOAD_LOCK mutex_lock(&load_mutex)
54#define LOAD_UNLOCK mutex_unlock(&load_mutex)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56static struct sidtab sidtab;
57struct policydb policydb;
58int ss_initialized = 0;
59
60/*
61 * The largest sequence number that has been used when
62 * providing an access decision to the access vector cache.
63 * The sequence number only changes when a policy change
64 * occurs.
65 */
66static u32 latest_granting = 0;
67
68/* Forward declaration. */
69static int context_struct_to_string(struct context *context, char **scontext,
70 u32 *scontext_len);
71
72/*
73 * Return the boolean value of a constraint expression
74 * when it is applied to the specified source and target
75 * security contexts.
76 *
77 * xcontext is a special beast... It is used by the validatetrans rules
78 * only. For these rules, scontext is the context before the transition,
79 * tcontext is the context after the transition, and xcontext is the context
80 * of the process performing the transition. All other callers of
81 * constraint_expr_eval should pass in NULL for xcontext.
82 */
83static int constraint_expr_eval(struct context *scontext,
84 struct context *tcontext,
85 struct context *xcontext,
86 struct constraint_expr *cexpr)
87{
88 u32 val1, val2;
89 struct context *c;
90 struct role_datum *r1, *r2;
91 struct mls_level *l1, *l2;
92 struct constraint_expr *e;
93 int s[CEXPR_MAXDEPTH];
94 int sp = -1;
95
96 for (e = cexpr; e; e = e->next) {
97 switch (e->expr_type) {
98 case CEXPR_NOT:
99 BUG_ON(sp < 0);
100 s[sp] = !s[sp];
101 break;
102 case CEXPR_AND:
103 BUG_ON(sp < 1);
104 sp--;
105 s[sp] &= s[sp+1];
106 break;
107 case CEXPR_OR:
108 BUG_ON(sp < 1);
109 sp--;
110 s[sp] |= s[sp+1];
111 break;
112 case CEXPR_ATTR:
113 if (sp == (CEXPR_MAXDEPTH-1))
114 return 0;
115 switch (e->attr) {
116 case CEXPR_USER:
117 val1 = scontext->user;
118 val2 = tcontext->user;
119 break;
120 case CEXPR_TYPE:
121 val1 = scontext->type;
122 val2 = tcontext->type;
123 break;
124 case CEXPR_ROLE:
125 val1 = scontext->role;
126 val2 = tcontext->role;
127 r1 = policydb.role_val_to_struct[val1 - 1];
128 r2 = policydb.role_val_to_struct[val2 - 1];
129 switch (e->op) {
130 case CEXPR_DOM:
131 s[++sp] = ebitmap_get_bit(&r1->dominates,
132 val2 - 1);
133 continue;
134 case CEXPR_DOMBY:
135 s[++sp] = ebitmap_get_bit(&r2->dominates,
136 val1 - 1);
137 continue;
138 case CEXPR_INCOMP:
139 s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
140 val2 - 1) &&
141 !ebitmap_get_bit(&r2->dominates,
142 val1 - 1) );
143 continue;
144 default:
145 break;
146 }
147 break;
148 case CEXPR_L1L2:
149 l1 = &(scontext->range.level[0]);
150 l2 = &(tcontext->range.level[0]);
151 goto mls_ops;
152 case CEXPR_L1H2:
153 l1 = &(scontext->range.level[0]);
154 l2 = &(tcontext->range.level[1]);
155 goto mls_ops;
156 case CEXPR_H1L2:
157 l1 = &(scontext->range.level[1]);
158 l2 = &(tcontext->range.level[0]);
159 goto mls_ops;
160 case CEXPR_H1H2:
161 l1 = &(scontext->range.level[1]);
162 l2 = &(tcontext->range.level[1]);
163 goto mls_ops;
164 case CEXPR_L1H1:
165 l1 = &(scontext->range.level[0]);
166 l2 = &(scontext->range.level[1]);
167 goto mls_ops;
168 case CEXPR_L2H2:
169 l1 = &(tcontext->range.level[0]);
170 l2 = &(tcontext->range.level[1]);
171 goto mls_ops;
172mls_ops:
173 switch (e->op) {
174 case CEXPR_EQ:
175 s[++sp] = mls_level_eq(l1, l2);
176 continue;
177 case CEXPR_NEQ:
178 s[++sp] = !mls_level_eq(l1, l2);
179 continue;
180 case CEXPR_DOM:
181 s[++sp] = mls_level_dom(l1, l2);
182 continue;
183 case CEXPR_DOMBY:
184 s[++sp] = mls_level_dom(l2, l1);
185 continue;
186 case CEXPR_INCOMP:
187 s[++sp] = mls_level_incomp(l2, l1);
188 continue;
189 default:
190 BUG();
191 return 0;
192 }
193 break;
194 default:
195 BUG();
196 return 0;
197 }
198
199 switch (e->op) {
200 case CEXPR_EQ:
201 s[++sp] = (val1 == val2);
202 break;
203 case CEXPR_NEQ:
204 s[++sp] = (val1 != val2);
205 break;
206 default:
207 BUG();
208 return 0;
209 }
210 break;
211 case CEXPR_NAMES:
212 if (sp == (CEXPR_MAXDEPTH-1))
213 return 0;
214 c = scontext;
215 if (e->attr & CEXPR_TARGET)
216 c = tcontext;
217 else if (e->attr & CEXPR_XTARGET) {
218 c = xcontext;
219 if (!c) {
220 BUG();
221 return 0;
222 }
223 }
224 if (e->attr & CEXPR_USER)
225 val1 = c->user;
226 else if (e->attr & CEXPR_ROLE)
227 val1 = c->role;
228 else if (e->attr & CEXPR_TYPE)
229 val1 = c->type;
230 else {
231 BUG();
232 return 0;
233 }
234
235 switch (e->op) {
236 case CEXPR_EQ:
237 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
238 break;
239 case CEXPR_NEQ:
240 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
241 break;
242 default:
243 BUG();
244 return 0;
245 }
246 break;
247 default:
248 BUG();
249 return 0;
250 }
251 }
252
253 BUG_ON(sp != 0);
254 return s[0];
255}
256
257/*
258 * Compute access vectors based on a context structure pair for
259 * the permissions in a particular class.
260 */
261static int context_struct_compute_av(struct context *scontext,
262 struct context *tcontext,
263 u16 tclass,
264 u32 requested,
265 struct av_decision *avd)
266{
267 struct constraint_node *constraint;
268 struct role_allow *ra;
269 struct avtab_key avkey;
Stephen Smalley782ebb92005-09-03 15:55:16 -0700270 struct avtab_node *node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 struct class_datum *tclass_datum;
Stephen Smalley782ebb92005-09-03 15:55:16 -0700272 struct ebitmap *sattr, *tattr;
273 struct ebitmap_node *snode, *tnode;
274 unsigned int i, j;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276 /*
277 * Remap extended Netlink classes for old policy versions.
278 * Do this here rather than socket_type_to_security_class()
279 * in case a newer policy version is loaded, allowing sockets
280 * to remain in the correct class.
281 */
282 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
283 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
284 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
285 tclass = SECCLASS_NETLINK_SOCKET;
286
287 if (!tclass || tclass > policydb.p_classes.nprim) {
288 printk(KERN_ERR "security_compute_av: unrecognized class %d\n",
289 tclass);
290 return -EINVAL;
291 }
292 tclass_datum = policydb.class_val_to_struct[tclass - 1];
293
294 /*
295 * Initialize the access vectors to the default values.
296 */
297 avd->allowed = 0;
298 avd->decided = 0xffffffff;
299 avd->auditallow = 0;
300 avd->auditdeny = 0xffffffff;
301 avd->seqno = latest_granting;
302
303 /*
304 * If a specific type enforcement rule was defined for
305 * this permission check, then use it.
306 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 avkey.target_class = tclass;
Stephen Smalley782ebb92005-09-03 15:55:16 -0700308 avkey.specified = AVTAB_AV;
309 sattr = &policydb.type_attr_map[scontext->type - 1];
310 tattr = &policydb.type_attr_map[tcontext->type - 1];
311 ebitmap_for_each_bit(sattr, snode, i) {
312 if (!ebitmap_node_get_bit(snode, i))
313 continue;
314 ebitmap_for_each_bit(tattr, tnode, j) {
315 if (!ebitmap_node_get_bit(tnode, j))
316 continue;
317 avkey.source_type = i + 1;
318 avkey.target_type = j + 1;
319 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
320 node != NULL;
321 node = avtab_search_node_next(node, avkey.specified)) {
322 if (node->key.specified == AVTAB_ALLOWED)
323 avd->allowed |= node->datum.data;
324 else if (node->key.specified == AVTAB_AUDITALLOW)
325 avd->auditallow |= node->datum.data;
326 else if (node->key.specified == AVTAB_AUDITDENY)
327 avd->auditdeny &= node->datum.data;
328 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Stephen Smalley782ebb92005-09-03 15:55:16 -0700330 /* Check conditional av table for additional permissions */
331 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
332
333 }
334 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
336 /*
337 * Remove any permissions prohibited by a constraint (this includes
338 * the MLS policy).
339 */
340 constraint = tclass_datum->constraints;
341 while (constraint) {
342 if ((constraint->permissions & (avd->allowed)) &&
343 !constraint_expr_eval(scontext, tcontext, NULL,
344 constraint->expr)) {
345 avd->allowed = (avd->allowed) & ~(constraint->permissions);
346 }
347 constraint = constraint->next;
348 }
349
350 /*
351 * If checking process transition permission and the
352 * role is changing, then check the (current_role, new_role)
353 * pair.
354 */
355 if (tclass == SECCLASS_PROCESS &&
356 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
357 scontext->role != tcontext->role) {
358 for (ra = policydb.role_allow; ra; ra = ra->next) {
359 if (scontext->role == ra->role &&
360 tcontext->role == ra->new_role)
361 break;
362 }
363 if (!ra)
364 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
365 PROCESS__DYNTRANSITION);
366 }
367
368 return 0;
369}
370
371static int security_validtrans_handle_fail(struct context *ocontext,
372 struct context *ncontext,
373 struct context *tcontext,
374 u16 tclass)
375{
376 char *o = NULL, *n = NULL, *t = NULL;
377 u32 olen, nlen, tlen;
378
379 if (context_struct_to_string(ocontext, &o, &olen) < 0)
380 goto out;
381 if (context_struct_to_string(ncontext, &n, &nlen) < 0)
382 goto out;
383 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
384 goto out;
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100385 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 "security_validate_transition: denied for"
387 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
388 o, n, t, policydb.p_class_val_to_name[tclass-1]);
389out:
390 kfree(o);
391 kfree(n);
392 kfree(t);
393
394 if (!selinux_enforcing)
395 return 0;
396 return -EPERM;
397}
398
399int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
400 u16 tclass)
401{
402 struct context *ocontext;
403 struct context *ncontext;
404 struct context *tcontext;
405 struct class_datum *tclass_datum;
406 struct constraint_node *constraint;
407 int rc = 0;
408
409 if (!ss_initialized)
410 return 0;
411
412 POLICY_RDLOCK;
413
414 /*
415 * Remap extended Netlink classes for old policy versions.
416 * Do this here rather than socket_type_to_security_class()
417 * in case a newer policy version is loaded, allowing sockets
418 * to remain in the correct class.
419 */
420 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
421 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
422 tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
423 tclass = SECCLASS_NETLINK_SOCKET;
424
425 if (!tclass || tclass > policydb.p_classes.nprim) {
426 printk(KERN_ERR "security_validate_transition: "
427 "unrecognized class %d\n", tclass);
428 rc = -EINVAL;
429 goto out;
430 }
431 tclass_datum = policydb.class_val_to_struct[tclass - 1];
432
433 ocontext = sidtab_search(&sidtab, oldsid);
434 if (!ocontext) {
435 printk(KERN_ERR "security_validate_transition: "
436 " unrecognized SID %d\n", oldsid);
437 rc = -EINVAL;
438 goto out;
439 }
440
441 ncontext = sidtab_search(&sidtab, newsid);
442 if (!ncontext) {
443 printk(KERN_ERR "security_validate_transition: "
444 " unrecognized SID %d\n", newsid);
445 rc = -EINVAL;
446 goto out;
447 }
448
449 tcontext = sidtab_search(&sidtab, tasksid);
450 if (!tcontext) {
451 printk(KERN_ERR "security_validate_transition: "
452 " unrecognized SID %d\n", tasksid);
453 rc = -EINVAL;
454 goto out;
455 }
456
457 constraint = tclass_datum->validatetrans;
458 while (constraint) {
459 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
460 constraint->expr)) {
461 rc = security_validtrans_handle_fail(ocontext, ncontext,
462 tcontext, tclass);
463 goto out;
464 }
465 constraint = constraint->next;
466 }
467
468out:
469 POLICY_RDUNLOCK;
470 return rc;
471}
472
473/**
474 * security_compute_av - Compute access vector decisions.
475 * @ssid: source security identifier
476 * @tsid: target security identifier
477 * @tclass: target security class
478 * @requested: requested permissions
479 * @avd: access vector decisions
480 *
481 * Compute a set of access vector decisions based on the
482 * SID pair (@ssid, @tsid) for the permissions in @tclass.
483 * Return -%EINVAL if any of the parameters are invalid or %0
484 * if the access vector decisions were computed successfully.
485 */
486int security_compute_av(u32 ssid,
487 u32 tsid,
488 u16 tclass,
489 u32 requested,
490 struct av_decision *avd)
491{
492 struct context *scontext = NULL, *tcontext = NULL;
493 int rc = 0;
494
495 if (!ss_initialized) {
Stephen Smalley4c443d12005-05-16 21:53:52 -0700496 avd->allowed = 0xffffffff;
497 avd->decided = 0xffffffff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 avd->auditallow = 0;
499 avd->auditdeny = 0xffffffff;
500 avd->seqno = latest_granting;
501 return 0;
502 }
503
504 POLICY_RDLOCK;
505
506 scontext = sidtab_search(&sidtab, ssid);
507 if (!scontext) {
508 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
509 ssid);
510 rc = -EINVAL;
511 goto out;
512 }
513 tcontext = sidtab_search(&sidtab, tsid);
514 if (!tcontext) {
515 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
516 tsid);
517 rc = -EINVAL;
518 goto out;
519 }
520
521 rc = context_struct_compute_av(scontext, tcontext, tclass,
522 requested, avd);
523out:
524 POLICY_RDUNLOCK;
525 return rc;
526}
527
528/*
529 * Write the security context string representation of
530 * the context structure `context' into a dynamically
531 * allocated string of the correct size. Set `*scontext'
532 * to point to this string and set `*scontext_len' to
533 * the length of the string.
534 */
535static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
536{
537 char *scontextp;
538
539 *scontext = NULL;
540 *scontext_len = 0;
541
542 /* Compute the size of the context. */
543 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
544 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
545 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
546 *scontext_len += mls_compute_context_len(context);
547
548 /* Allocate space for the context; caller must free this space. */
549 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
550 if (!scontextp) {
551 return -ENOMEM;
552 }
553 *scontext = scontextp;
554
555 /*
556 * Copy the user name, role name and type name into the context.
557 */
558 sprintf(scontextp, "%s:%s:%s",
559 policydb.p_user_val_to_name[context->user - 1],
560 policydb.p_role_val_to_name[context->role - 1],
561 policydb.p_type_val_to_name[context->type - 1]);
562 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
563 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
564 1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
565
566 mls_sid_to_context(context, &scontextp);
567
568 *scontextp = 0;
569
570 return 0;
571}
572
573#include "initial_sid_to_string.h"
574
575/**
576 * security_sid_to_context - Obtain a context for a given SID.
577 * @sid: security identifier, SID
578 * @scontext: security context
579 * @scontext_len: length in bytes
580 *
581 * Write the string representation of the context associated with @sid
582 * into a dynamically allocated string of the correct size. Set @scontext
583 * to point to this string and set @scontext_len to the length of the string.
584 */
585int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
586{
587 struct context *context;
588 int rc = 0;
589
590 if (!ss_initialized) {
591 if (sid <= SECINITSID_NUM) {
592 char *scontextp;
593
594 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
595 scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
596 strcpy(scontextp, initial_sid_to_string[sid]);
597 *scontext = scontextp;
598 goto out;
599 }
600 printk(KERN_ERR "security_sid_to_context: called before initial "
601 "load_policy on unknown SID %d\n", sid);
602 rc = -EINVAL;
603 goto out;
604 }
605 POLICY_RDLOCK;
606 context = sidtab_search(&sidtab, sid);
607 if (!context) {
608 printk(KERN_ERR "security_sid_to_context: unrecognized SID "
609 "%d\n", sid);
610 rc = -EINVAL;
611 goto out_unlock;
612 }
613 rc = context_struct_to_string(context, scontext, scontext_len);
614out_unlock:
615 POLICY_RDUNLOCK;
616out:
617 return rc;
618
619}
620
James Morrisf5c1d5b2005-07-28 01:07:37 -0700621static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622{
623 char *scontext2;
624 struct context context;
625 struct role_datum *role;
626 struct type_datum *typdatum;
627 struct user_datum *usrdatum;
628 char *scontextp, *p, oldc;
629 int rc = 0;
630
631 if (!ss_initialized) {
632 int i;
633
634 for (i = 1; i < SECINITSID_NUM; i++) {
635 if (!strcmp(initial_sid_to_string[i], scontext)) {
636 *sid = i;
637 goto out;
638 }
639 }
640 *sid = SECINITSID_KERNEL;
641 goto out;
642 }
643 *sid = SECSID_NULL;
644
645 /* Copy the string so that we can modify the copy as we parse it.
646 The string should already by null terminated, but we append a
647 null suffix to the copy to avoid problems with the existing
648 attr package, which doesn't view the null terminator as part
649 of the attribute value. */
650 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
651 if (!scontext2) {
652 rc = -ENOMEM;
653 goto out;
654 }
655 memcpy(scontext2, scontext, scontext_len);
656 scontext2[scontext_len] = 0;
657
658 context_init(&context);
659 *sid = SECSID_NULL;
660
661 POLICY_RDLOCK;
662
663 /* Parse the security context. */
664
665 rc = -EINVAL;
666 scontextp = (char *) scontext2;
667
668 /* Extract the user. */
669 p = scontextp;
670 while (*p && *p != ':')
671 p++;
672
673 if (*p == 0)
674 goto out_unlock;
675
676 *p++ = 0;
677
678 usrdatum = hashtab_search(policydb.p_users.table, scontextp);
679 if (!usrdatum)
680 goto out_unlock;
681
682 context.user = usrdatum->value;
683
684 /* Extract role. */
685 scontextp = p;
686 while (*p && *p != ':')
687 p++;
688
689 if (*p == 0)
690 goto out_unlock;
691
692 *p++ = 0;
693
694 role = hashtab_search(policydb.p_roles.table, scontextp);
695 if (!role)
696 goto out_unlock;
697 context.role = role->value;
698
699 /* Extract type. */
700 scontextp = p;
701 while (*p && *p != ':')
702 p++;
703 oldc = *p;
704 *p++ = 0;
705
706 typdatum = hashtab_search(policydb.p_types.table, scontextp);
707 if (!typdatum)
708 goto out_unlock;
709
710 context.type = typdatum->value;
711
James Morrisf5c1d5b2005-07-28 01:07:37 -0700712 rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (rc)
714 goto out_unlock;
715
716 if ((p - scontext2) < scontext_len) {
717 rc = -EINVAL;
718 goto out_unlock;
719 }
720
721 /* Check the validity of the new context. */
722 if (!policydb_context_isvalid(&policydb, &context)) {
723 rc = -EINVAL;
724 goto out_unlock;
725 }
726 /* Obtain the new sid. */
727 rc = sidtab_context_to_sid(&sidtab, &context, sid);
728out_unlock:
729 POLICY_RDUNLOCK;
730 context_destroy(&context);
731 kfree(scontext2);
732out:
733 return rc;
734}
735
James Morrisf5c1d5b2005-07-28 01:07:37 -0700736/**
737 * security_context_to_sid - Obtain a SID for a given security context.
738 * @scontext: security context
739 * @scontext_len: length in bytes
740 * @sid: security identifier, SID
741 *
742 * Obtains a SID associated with the security context that
743 * has the string representation specified by @scontext.
744 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
745 * memory is available, or 0 on success.
746 */
747int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
748{
749 return security_context_to_sid_core(scontext, scontext_len,
750 sid, SECSID_NULL);
751}
752
753/**
754 * security_context_to_sid_default - Obtain a SID for a given security context,
755 * falling back to specified default if needed.
756 *
757 * @scontext: security context
758 * @scontext_len: length in bytes
759 * @sid: security identifier, SID
760 * @def_sid: default SID to assign on errror
761 *
762 * Obtains a SID associated with the security context that
763 * has the string representation specified by @scontext.
764 * The default SID is passed to the MLS layer to be used to allow
765 * kernel labeling of the MLS field if the MLS field is not present
766 * (for upgrading to MLS without full relabel).
767 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
768 * memory is available, or 0 on success.
769 */
770int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
771{
772 return security_context_to_sid_core(scontext, scontext_len,
773 sid, def_sid);
774}
775
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776static int compute_sid_handle_invalid_context(
777 struct context *scontext,
778 struct context *tcontext,
779 u16 tclass,
780 struct context *newcontext)
781{
782 char *s = NULL, *t = NULL, *n = NULL;
783 u32 slen, tlen, nlen;
784
785 if (context_struct_to_string(scontext, &s, &slen) < 0)
786 goto out;
787 if (context_struct_to_string(tcontext, &t, &tlen) < 0)
788 goto out;
789 if (context_struct_to_string(newcontext, &n, &nlen) < 0)
790 goto out;
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100791 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 "security_compute_sid: invalid context %s"
793 " for scontext=%s"
794 " tcontext=%s"
795 " tclass=%s",
796 n, s, t, policydb.p_class_val_to_name[tclass-1]);
797out:
798 kfree(s);
799 kfree(t);
800 kfree(n);
801 if (!selinux_enforcing)
802 return 0;
803 return -EACCES;
804}
805
806static int security_compute_sid(u32 ssid,
807 u32 tsid,
808 u16 tclass,
809 u32 specified,
810 u32 *out_sid)
811{
812 struct context *scontext = NULL, *tcontext = NULL, newcontext;
813 struct role_trans *roletr = NULL;
814 struct avtab_key avkey;
815 struct avtab_datum *avdatum;
816 struct avtab_node *node;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 int rc = 0;
818
819 if (!ss_initialized) {
820 switch (tclass) {
821 case SECCLASS_PROCESS:
822 *out_sid = ssid;
823 break;
824 default:
825 *out_sid = tsid;
826 break;
827 }
828 goto out;
829 }
830
831 POLICY_RDLOCK;
832
833 scontext = sidtab_search(&sidtab, ssid);
834 if (!scontext) {
835 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
836 ssid);
837 rc = -EINVAL;
838 goto out_unlock;
839 }
840 tcontext = sidtab_search(&sidtab, tsid);
841 if (!tcontext) {
842 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
843 tsid);
844 rc = -EINVAL;
845 goto out_unlock;
846 }
847
848 context_init(&newcontext);
849
850 /* Set the user identity. */
851 switch (specified) {
852 case AVTAB_TRANSITION:
853 case AVTAB_CHANGE:
854 /* Use the process user identity. */
855 newcontext.user = scontext->user;
856 break;
857 case AVTAB_MEMBER:
858 /* Use the related object owner. */
859 newcontext.user = tcontext->user;
860 break;
861 }
862
863 /* Set the role and type to default values. */
864 switch (tclass) {
865 case SECCLASS_PROCESS:
866 /* Use the current role and type of process. */
867 newcontext.role = scontext->role;
868 newcontext.type = scontext->type;
869 break;
870 default:
871 /* Use the well-defined object role. */
872 newcontext.role = OBJECT_R_VAL;
873 /* Use the type of the related object. */
874 newcontext.type = tcontext->type;
875 }
876
877 /* Look for a type transition/member/change rule. */
878 avkey.source_type = scontext->type;
879 avkey.target_type = tcontext->type;
880 avkey.target_class = tclass;
Stephen Smalley782ebb92005-09-03 15:55:16 -0700881 avkey.specified = specified;
882 avdatum = avtab_search(&policydb.te_avtab, &avkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 /* If no permanent rule, also check for enabled conditional rules */
885 if(!avdatum) {
Stephen Smalley782ebb92005-09-03 15:55:16 -0700886 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
Stephen Smalley782ebb92005-09-03 15:55:16 -0700888 if (node->key.specified & AVTAB_ENABLED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 avdatum = &node->datum;
890 break;
891 }
892 }
893 }
894
Stephen Smalley782ebb92005-09-03 15:55:16 -0700895 if (avdatum) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 /* Use the type from the type transition/member/change rule. */
Stephen Smalley782ebb92005-09-03 15:55:16 -0700897 newcontext.type = avdatum->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 }
899
900 /* Check for class-specific changes. */
901 switch (tclass) {
902 case SECCLASS_PROCESS:
903 if (specified & AVTAB_TRANSITION) {
904 /* Look for a role transition rule. */
905 for (roletr = policydb.role_tr; roletr;
906 roletr = roletr->next) {
907 if (roletr->role == scontext->role &&
908 roletr->type == tcontext->type) {
909 /* Use the role transition rule. */
910 newcontext.role = roletr->new_role;
911 break;
912 }
913 }
914 }
915 break;
916 default:
917 break;
918 }
919
920 /* Set the MLS attributes.
921 This is done last because it may allocate memory. */
922 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
923 if (rc)
924 goto out_unlock;
925
926 /* Check the validity of the context. */
927 if (!policydb_context_isvalid(&policydb, &newcontext)) {
928 rc = compute_sid_handle_invalid_context(scontext,
929 tcontext,
930 tclass,
931 &newcontext);
932 if (rc)
933 goto out_unlock;
934 }
935 /* Obtain the sid for the context. */
936 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
937out_unlock:
938 POLICY_RDUNLOCK;
939 context_destroy(&newcontext);
940out:
941 return rc;
942}
943
944/**
945 * security_transition_sid - Compute the SID for a new subject/object.
946 * @ssid: source security identifier
947 * @tsid: target security identifier
948 * @tclass: target security class
949 * @out_sid: security identifier for new subject/object
950 *
951 * Compute a SID to use for labeling a new subject or object in the
952 * class @tclass based on a SID pair (@ssid, @tsid).
953 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
954 * if insufficient memory is available, or %0 if the new SID was
955 * computed successfully.
956 */
957int security_transition_sid(u32 ssid,
958 u32 tsid,
959 u16 tclass,
960 u32 *out_sid)
961{
962 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
963}
964
965/**
966 * security_member_sid - Compute the SID for member selection.
967 * @ssid: source security identifier
968 * @tsid: target security identifier
969 * @tclass: target security class
970 * @out_sid: security identifier for selected member
971 *
972 * Compute a SID to use when selecting a member of a polyinstantiated
973 * object of class @tclass based on a SID pair (@ssid, @tsid).
974 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
975 * if insufficient memory is available, or %0 if the SID was
976 * computed successfully.
977 */
978int security_member_sid(u32 ssid,
979 u32 tsid,
980 u16 tclass,
981 u32 *out_sid)
982{
983 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
984}
985
986/**
987 * security_change_sid - Compute the SID for object relabeling.
988 * @ssid: source security identifier
989 * @tsid: target security identifier
990 * @tclass: target security class
991 * @out_sid: security identifier for selected member
992 *
993 * Compute a SID to use for relabeling an object of class @tclass
994 * based on a SID pair (@ssid, @tsid).
995 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
996 * if insufficient memory is available, or %0 if the SID was
997 * computed successfully.
998 */
999int security_change_sid(u32 ssid,
1000 u32 tsid,
1001 u16 tclass,
1002 u32 *out_sid)
1003{
1004 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1005}
1006
1007/*
1008 * Verify that each permission that is defined under the
1009 * existing policy is still defined with the same value
1010 * in the new policy.
1011 */
1012static int validate_perm(void *key, void *datum, void *p)
1013{
1014 struct hashtab *h;
1015 struct perm_datum *perdatum, *perdatum2;
1016 int rc = 0;
1017
1018
1019 h = p;
1020 perdatum = datum;
1021
1022 perdatum2 = hashtab_search(h, key);
1023 if (!perdatum2) {
1024 printk(KERN_ERR "security: permission %s disappeared",
1025 (char *)key);
1026 rc = -ENOENT;
1027 goto out;
1028 }
1029 if (perdatum->value != perdatum2->value) {
1030 printk(KERN_ERR "security: the value of permission %s changed",
1031 (char *)key);
1032 rc = -EINVAL;
1033 }
1034out:
1035 return rc;
1036}
1037
1038/*
1039 * Verify that each class that is defined under the
1040 * existing policy is still defined with the same
1041 * attributes in the new policy.
1042 */
1043static int validate_class(void *key, void *datum, void *p)
1044{
1045 struct policydb *newp;
1046 struct class_datum *cladatum, *cladatum2;
1047 int rc;
1048
1049 newp = p;
1050 cladatum = datum;
1051
1052 cladatum2 = hashtab_search(newp->p_classes.table, key);
1053 if (!cladatum2) {
1054 printk(KERN_ERR "security: class %s disappeared\n",
1055 (char *)key);
1056 rc = -ENOENT;
1057 goto out;
1058 }
1059 if (cladatum->value != cladatum2->value) {
1060 printk(KERN_ERR "security: the value of class %s changed\n",
1061 (char *)key);
1062 rc = -EINVAL;
1063 goto out;
1064 }
1065 if ((cladatum->comdatum && !cladatum2->comdatum) ||
1066 (!cladatum->comdatum && cladatum2->comdatum)) {
1067 printk(KERN_ERR "security: the inherits clause for the access "
1068 "vector definition for class %s changed\n", (char *)key);
1069 rc = -EINVAL;
1070 goto out;
1071 }
1072 if (cladatum->comdatum) {
1073 rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm,
1074 cladatum2->comdatum->permissions.table);
1075 if (rc) {
1076 printk(" in the access vector definition for class "
1077 "%s\n", (char *)key);
1078 goto out;
1079 }
1080 }
1081 rc = hashtab_map(cladatum->permissions.table, validate_perm,
1082 cladatum2->permissions.table);
1083 if (rc)
1084 printk(" in access vector definition for class %s\n",
1085 (char *)key);
1086out:
1087 return rc;
1088}
1089
1090/* Clone the SID into the new SID table. */
1091static int clone_sid(u32 sid,
1092 struct context *context,
1093 void *arg)
1094{
1095 struct sidtab *s = arg;
1096
1097 return sidtab_insert(s, sid, context);
1098}
1099
1100static inline int convert_context_handle_invalid_context(struct context *context)
1101{
1102 int rc = 0;
1103
1104 if (selinux_enforcing) {
1105 rc = -EINVAL;
1106 } else {
1107 char *s;
1108 u32 len;
1109
1110 context_struct_to_string(context, &s, &len);
1111 printk(KERN_ERR "security: context %s is invalid\n", s);
1112 kfree(s);
1113 }
1114 return rc;
1115}
1116
1117struct convert_context_args {
1118 struct policydb *oldp;
1119 struct policydb *newp;
1120};
1121
1122/*
1123 * Convert the values in the security context
1124 * structure `c' from the values specified
1125 * in the policy `p->oldp' to the values specified
1126 * in the policy `p->newp'. Verify that the
1127 * context is valid under the new policy.
1128 */
1129static int convert_context(u32 key,
1130 struct context *c,
1131 void *p)
1132{
1133 struct convert_context_args *args;
1134 struct context oldc;
1135 struct role_datum *role;
1136 struct type_datum *typdatum;
1137 struct user_datum *usrdatum;
1138 char *s;
1139 u32 len;
1140 int rc;
1141
1142 args = p;
1143
1144 rc = context_cpy(&oldc, c);
1145 if (rc)
1146 goto out;
1147
1148 rc = -EINVAL;
1149
1150 /* Convert the user. */
1151 usrdatum = hashtab_search(args->newp->p_users.table,
1152 args->oldp->p_user_val_to_name[c->user - 1]);
1153 if (!usrdatum) {
1154 goto bad;
1155 }
1156 c->user = usrdatum->value;
1157
1158 /* Convert the role. */
1159 role = hashtab_search(args->newp->p_roles.table,
1160 args->oldp->p_role_val_to_name[c->role - 1]);
1161 if (!role) {
1162 goto bad;
1163 }
1164 c->role = role->value;
1165
1166 /* Convert the type. */
1167 typdatum = hashtab_search(args->newp->p_types.table,
1168 args->oldp->p_type_val_to_name[c->type - 1]);
1169 if (!typdatum) {
1170 goto bad;
1171 }
1172 c->type = typdatum->value;
1173
1174 rc = mls_convert_context(args->oldp, args->newp, c);
1175 if (rc)
1176 goto bad;
1177
1178 /* Check the validity of the new context. */
1179 if (!policydb_context_isvalid(args->newp, c)) {
1180 rc = convert_context_handle_invalid_context(&oldc);
1181 if (rc)
1182 goto bad;
1183 }
1184
1185 context_destroy(&oldc);
1186out:
1187 return rc;
1188bad:
1189 context_struct_to_string(&oldc, &s, &len);
1190 context_destroy(&oldc);
1191 printk(KERN_ERR "security: invalidating context %s\n", s);
1192 kfree(s);
1193 goto out;
1194}
1195
1196extern void selinux_complete_init(void);
1197
1198/**
1199 * security_load_policy - Load a security policy configuration.
1200 * @data: binary policy data
1201 * @len: length of data in bytes
1202 *
1203 * Load a new set of security policy configuration data,
1204 * validate it and convert the SID table as necessary.
1205 * This function will flush the access vector cache after
1206 * loading the new policy.
1207 */
1208int security_load_policy(void *data, size_t len)
1209{
1210 struct policydb oldpolicydb, newpolicydb;
1211 struct sidtab oldsidtab, newsidtab;
1212 struct convert_context_args args;
1213 u32 seqno;
1214 int rc = 0;
1215 struct policy_file file = { data, len }, *fp = &file;
1216
1217 LOAD_LOCK;
1218
1219 if (!ss_initialized) {
1220 avtab_cache_init();
1221 if (policydb_read(&policydb, fp)) {
1222 LOAD_UNLOCK;
1223 avtab_cache_destroy();
1224 return -EINVAL;
1225 }
1226 if (policydb_load_isids(&policydb, &sidtab)) {
1227 LOAD_UNLOCK;
1228 policydb_destroy(&policydb);
1229 avtab_cache_destroy();
1230 return -EINVAL;
1231 }
1232 policydb_loaded_version = policydb.policyvers;
1233 ss_initialized = 1;
Stephen Smalley4c443d12005-05-16 21:53:52 -07001234 seqno = ++latest_granting;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 LOAD_UNLOCK;
1236 selinux_complete_init();
Stephen Smalley4c443d12005-05-16 21:53:52 -07001237 avc_ss_reset(seqno);
1238 selnl_notify_policyload(seqno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 return 0;
1240 }
1241
1242#if 0
1243 sidtab_hash_eval(&sidtab, "sids");
1244#endif
1245
1246 if (policydb_read(&newpolicydb, fp)) {
1247 LOAD_UNLOCK;
1248 return -EINVAL;
1249 }
1250
1251 sidtab_init(&newsidtab);
1252
1253 /* Verify that the existing classes did not change. */
1254 if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) {
1255 printk(KERN_ERR "security: the definition of an existing "
1256 "class changed\n");
1257 rc = -EINVAL;
1258 goto err;
1259 }
1260
1261 /* Clone the SID table. */
1262 sidtab_shutdown(&sidtab);
1263 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1264 rc = -ENOMEM;
1265 goto err;
1266 }
1267
1268 /* Convert the internal representations of contexts
1269 in the new SID table and remove invalid SIDs. */
1270 args.oldp = &policydb;
1271 args.newp = &newpolicydb;
1272 sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1273
1274 /* Save the old policydb and SID table to free later. */
1275 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1276 sidtab_set(&oldsidtab, &sidtab);
1277
1278 /* Install the new policydb and SID table. */
1279 POLICY_WRLOCK;
1280 memcpy(&policydb, &newpolicydb, sizeof policydb);
1281 sidtab_set(&sidtab, &newsidtab);
1282 seqno = ++latest_granting;
1283 policydb_loaded_version = policydb.policyvers;
1284 POLICY_WRUNLOCK;
1285 LOAD_UNLOCK;
1286
1287 /* Free the old policydb and SID table. */
1288 policydb_destroy(&oldpolicydb);
1289 sidtab_destroy(&oldsidtab);
1290
1291 avc_ss_reset(seqno);
1292 selnl_notify_policyload(seqno);
1293
1294 return 0;
1295
1296err:
1297 LOAD_UNLOCK;
1298 sidtab_destroy(&newsidtab);
1299 policydb_destroy(&newpolicydb);
1300 return rc;
1301
1302}
1303
1304/**
1305 * security_port_sid - Obtain the SID for a port.
1306 * @domain: communication domain aka address family
1307 * @type: socket type
1308 * @protocol: protocol number
1309 * @port: port number
1310 * @out_sid: security identifier
1311 */
1312int security_port_sid(u16 domain,
1313 u16 type,
1314 u8 protocol,
1315 u16 port,
1316 u32 *out_sid)
1317{
1318 struct ocontext *c;
1319 int rc = 0;
1320
1321 POLICY_RDLOCK;
1322
1323 c = policydb.ocontexts[OCON_PORT];
1324 while (c) {
1325 if (c->u.port.protocol == protocol &&
1326 c->u.port.low_port <= port &&
1327 c->u.port.high_port >= port)
1328 break;
1329 c = c->next;
1330 }
1331
1332 if (c) {
1333 if (!c->sid[0]) {
1334 rc = sidtab_context_to_sid(&sidtab,
1335 &c->context[0],
1336 &c->sid[0]);
1337 if (rc)
1338 goto out;
1339 }
1340 *out_sid = c->sid[0];
1341 } else {
1342 *out_sid = SECINITSID_PORT;
1343 }
1344
1345out:
1346 POLICY_RDUNLOCK;
1347 return rc;
1348}
1349
1350/**
1351 * security_netif_sid - Obtain the SID for a network interface.
1352 * @name: interface name
1353 * @if_sid: interface SID
1354 * @msg_sid: default SID for received packets
1355 */
1356int security_netif_sid(char *name,
1357 u32 *if_sid,
1358 u32 *msg_sid)
1359{
1360 int rc = 0;
1361 struct ocontext *c;
1362
1363 POLICY_RDLOCK;
1364
1365 c = policydb.ocontexts[OCON_NETIF];
1366 while (c) {
1367 if (strcmp(name, c->u.name) == 0)
1368 break;
1369 c = c->next;
1370 }
1371
1372 if (c) {
1373 if (!c->sid[0] || !c->sid[1]) {
1374 rc = sidtab_context_to_sid(&sidtab,
1375 &c->context[0],
1376 &c->sid[0]);
1377 if (rc)
1378 goto out;
1379 rc = sidtab_context_to_sid(&sidtab,
1380 &c->context[1],
1381 &c->sid[1]);
1382 if (rc)
1383 goto out;
1384 }
1385 *if_sid = c->sid[0];
1386 *msg_sid = c->sid[1];
1387 } else {
1388 *if_sid = SECINITSID_NETIF;
1389 *msg_sid = SECINITSID_NETMSG;
1390 }
1391
1392out:
1393 POLICY_RDUNLOCK;
1394 return rc;
1395}
1396
1397static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1398{
1399 int i, fail = 0;
1400
1401 for(i = 0; i < 4; i++)
1402 if(addr[i] != (input[i] & mask[i])) {
1403 fail = 1;
1404 break;
1405 }
1406
1407 return !fail;
1408}
1409
1410/**
1411 * security_node_sid - Obtain the SID for a node (host).
1412 * @domain: communication domain aka address family
1413 * @addrp: address
1414 * @addrlen: address length in bytes
1415 * @out_sid: security identifier
1416 */
1417int security_node_sid(u16 domain,
1418 void *addrp,
1419 u32 addrlen,
1420 u32 *out_sid)
1421{
1422 int rc = 0;
1423 struct ocontext *c;
1424
1425 POLICY_RDLOCK;
1426
1427 switch (domain) {
1428 case AF_INET: {
1429 u32 addr;
1430
1431 if (addrlen != sizeof(u32)) {
1432 rc = -EINVAL;
1433 goto out;
1434 }
1435
1436 addr = *((u32 *)addrp);
1437
1438 c = policydb.ocontexts[OCON_NODE];
1439 while (c) {
1440 if (c->u.node.addr == (addr & c->u.node.mask))
1441 break;
1442 c = c->next;
1443 }
1444 break;
1445 }
1446
1447 case AF_INET6:
1448 if (addrlen != sizeof(u64) * 2) {
1449 rc = -EINVAL;
1450 goto out;
1451 }
1452 c = policydb.ocontexts[OCON_NODE6];
1453 while (c) {
1454 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1455 c->u.node6.mask))
1456 break;
1457 c = c->next;
1458 }
1459 break;
1460
1461 default:
1462 *out_sid = SECINITSID_NODE;
1463 goto out;
1464 }
1465
1466 if (c) {
1467 if (!c->sid[0]) {
1468 rc = sidtab_context_to_sid(&sidtab,
1469 &c->context[0],
1470 &c->sid[0]);
1471 if (rc)
1472 goto out;
1473 }
1474 *out_sid = c->sid[0];
1475 } else {
1476 *out_sid = SECINITSID_NODE;
1477 }
1478
1479out:
1480 POLICY_RDUNLOCK;
1481 return rc;
1482}
1483
1484#define SIDS_NEL 25
1485
1486/**
1487 * security_get_user_sids - Obtain reachable SIDs for a user.
1488 * @fromsid: starting SID
1489 * @username: username
1490 * @sids: array of reachable SIDs for user
1491 * @nel: number of elements in @sids
1492 *
1493 * Generate the set of SIDs for legal security contexts
1494 * for a given user that can be reached by @fromsid.
1495 * Set *@sids to point to a dynamically allocated
1496 * array containing the set of SIDs. Set *@nel to the
1497 * number of elements in the array.
1498 */
1499
1500int security_get_user_sids(u32 fromsid,
1501 char *username,
1502 u32 **sids,
1503 u32 *nel)
1504{
1505 struct context *fromcon, usercon;
1506 u32 *mysids, *mysids2, sid;
1507 u32 mynel = 0, maxnel = SIDS_NEL;
1508 struct user_datum *user;
1509 struct role_datum *role;
1510 struct av_decision avd;
Stephen Smalley782ebb92005-09-03 15:55:16 -07001511 struct ebitmap_node *rnode, *tnode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 int rc = 0, i, j;
1513
1514 if (!ss_initialized) {
1515 *sids = NULL;
1516 *nel = 0;
1517 goto out;
1518 }
1519
1520 POLICY_RDLOCK;
1521
1522 fromcon = sidtab_search(&sidtab, fromsid);
1523 if (!fromcon) {
1524 rc = -EINVAL;
1525 goto out_unlock;
1526 }
1527
1528 user = hashtab_search(policydb.p_users.table, username);
1529 if (!user) {
1530 rc = -EINVAL;
1531 goto out_unlock;
1532 }
1533 usercon.user = user->value;
1534
James Morris89d155e2005-10-30 14:59:21 -08001535 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 if (!mysids) {
1537 rc = -ENOMEM;
1538 goto out_unlock;
1539 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540
Stephen Smalley782ebb92005-09-03 15:55:16 -07001541 ebitmap_for_each_bit(&user->roles, rnode, i) {
1542 if (!ebitmap_node_get_bit(rnode, i))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001543 continue;
1544 role = policydb.role_val_to_struct[i];
1545 usercon.role = i+1;
Stephen Smalley782ebb92005-09-03 15:55:16 -07001546 ebitmap_for_each_bit(&role->types, tnode, j) {
1547 if (!ebitmap_node_get_bit(tnode, j))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 continue;
1549 usercon.type = j+1;
1550
1551 if (mls_setup_user_range(fromcon, user, &usercon))
1552 continue;
1553
1554 rc = context_struct_compute_av(fromcon, &usercon,
1555 SECCLASS_PROCESS,
1556 PROCESS__TRANSITION,
1557 &avd);
1558 if (rc || !(avd.allowed & PROCESS__TRANSITION))
1559 continue;
1560 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1561 if (rc) {
1562 kfree(mysids);
1563 goto out_unlock;
1564 }
1565 if (mynel < maxnel) {
1566 mysids[mynel++] = sid;
1567 } else {
1568 maxnel += SIDS_NEL;
James Morris89d155e2005-10-30 14:59:21 -08001569 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570 if (!mysids2) {
1571 rc = -ENOMEM;
1572 kfree(mysids);
1573 goto out_unlock;
1574 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001575 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1576 kfree(mysids);
1577 mysids = mysids2;
1578 mysids[mynel++] = sid;
1579 }
1580 }
1581 }
1582
1583 *sids = mysids;
1584 *nel = mynel;
1585
1586out_unlock:
1587 POLICY_RDUNLOCK;
1588out:
1589 return rc;
1590}
1591
1592/**
1593 * security_genfs_sid - Obtain a SID for a file in a filesystem
1594 * @fstype: filesystem type
1595 * @path: path from root of mount
1596 * @sclass: file security class
1597 * @sid: SID for path
1598 *
1599 * Obtain a SID to use for a file in a filesystem that
1600 * cannot support xattr or use a fixed labeling behavior like
1601 * transition SIDs or task SIDs.
1602 */
1603int security_genfs_sid(const char *fstype,
1604 char *path,
1605 u16 sclass,
1606 u32 *sid)
1607{
1608 int len;
1609 struct genfs *genfs;
1610 struct ocontext *c;
1611 int rc = 0, cmp = 0;
1612
1613 POLICY_RDLOCK;
1614
1615 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1616 cmp = strcmp(fstype, genfs->fstype);
1617 if (cmp <= 0)
1618 break;
1619 }
1620
1621 if (!genfs || cmp) {
1622 *sid = SECINITSID_UNLABELED;
1623 rc = -ENOENT;
1624 goto out;
1625 }
1626
1627 for (c = genfs->head; c; c = c->next) {
1628 len = strlen(c->u.name);
1629 if ((!c->v.sclass || sclass == c->v.sclass) &&
1630 (strncmp(c->u.name, path, len) == 0))
1631 break;
1632 }
1633
1634 if (!c) {
1635 *sid = SECINITSID_UNLABELED;
1636 rc = -ENOENT;
1637 goto out;
1638 }
1639
1640 if (!c->sid[0]) {
1641 rc = sidtab_context_to_sid(&sidtab,
1642 &c->context[0],
1643 &c->sid[0]);
1644 if (rc)
1645 goto out;
1646 }
1647
1648 *sid = c->sid[0];
1649out:
1650 POLICY_RDUNLOCK;
1651 return rc;
1652}
1653
1654/**
1655 * security_fs_use - Determine how to handle labeling for a filesystem.
1656 * @fstype: filesystem type
1657 * @behavior: labeling behavior
1658 * @sid: SID for filesystem (superblock)
1659 */
1660int security_fs_use(
1661 const char *fstype,
1662 unsigned int *behavior,
1663 u32 *sid)
1664{
1665 int rc = 0;
1666 struct ocontext *c;
1667
1668 POLICY_RDLOCK;
1669
1670 c = policydb.ocontexts[OCON_FSUSE];
1671 while (c) {
1672 if (strcmp(fstype, c->u.name) == 0)
1673 break;
1674 c = c->next;
1675 }
1676
1677 if (c) {
1678 *behavior = c->v.behavior;
1679 if (!c->sid[0]) {
1680 rc = sidtab_context_to_sid(&sidtab,
1681 &c->context[0],
1682 &c->sid[0]);
1683 if (rc)
1684 goto out;
1685 }
1686 *sid = c->sid[0];
1687 } else {
1688 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1689 if (rc) {
1690 *behavior = SECURITY_FS_USE_NONE;
1691 rc = 0;
1692 } else {
1693 *behavior = SECURITY_FS_USE_GENFS;
1694 }
1695 }
1696
1697out:
1698 POLICY_RDUNLOCK;
1699 return rc;
1700}
1701
1702int security_get_bools(int *len, char ***names, int **values)
1703{
1704 int i, rc = -ENOMEM;
1705
1706 POLICY_RDLOCK;
1707 *names = NULL;
1708 *values = NULL;
1709
1710 *len = policydb.p_bools.nprim;
1711 if (!*len) {
1712 rc = 0;
1713 goto out;
1714 }
1715
Jesper Juhle0795cf2006-01-09 20:54:46 -08001716 *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 if (!*names)
1718 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719
Jesper Juhle0795cf2006-01-09 20:54:46 -08001720 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721 if (!*values)
1722 goto err;
1723
1724 for (i = 0; i < *len; i++) {
1725 size_t name_len;
1726 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1727 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
Jesper Juhle0795cf2006-01-09 20:54:46 -08001728 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 if (!(*names)[i])
1730 goto err;
1731 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1732 (*names)[i][name_len - 1] = 0;
1733 }
1734 rc = 0;
1735out:
1736 POLICY_RDUNLOCK;
1737 return rc;
1738err:
1739 if (*names) {
1740 for (i = 0; i < *len; i++)
Jesper Juhl9a5f04b2005-06-25 14:58:51 -07001741 kfree((*names)[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 }
Jesper Juhl9a5f04b2005-06-25 14:58:51 -07001743 kfree(*values);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 goto out;
1745}
1746
1747
1748int security_set_bools(int len, int *values)
1749{
1750 int i, rc = 0;
1751 int lenp, seqno = 0;
1752 struct cond_node *cur;
1753
1754 POLICY_WRLOCK;
1755
1756 lenp = policydb.p_bools.nprim;
1757 if (len != lenp) {
1758 rc = -EFAULT;
1759 goto out;
1760 }
1761
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762 for (i = 0; i < len; i++) {
Steve Grubbaf601e42006-01-04 14:08:39 +00001763 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1764 audit_log(current->audit_context, GFP_ATOMIC,
1765 AUDIT_MAC_CONFIG_CHANGE,
1766 "bool=%s val=%d old_val=%d auid=%u",
1767 policydb.p_bool_val_to_name[i],
1768 !!values[i],
1769 policydb.bool_val_to_struct[i]->state,
1770 audit_get_loginuid(current->audit_context));
1771 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 if (values[i]) {
1773 policydb.bool_val_to_struct[i]->state = 1;
1774 } else {
1775 policydb.bool_val_to_struct[i]->state = 0;
1776 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778
1779 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1780 rc = evaluate_cond_node(&policydb, cur);
1781 if (rc)
1782 goto out;
1783 }
1784
1785 seqno = ++latest_granting;
1786
1787out:
1788 POLICY_WRUNLOCK;
1789 if (!rc) {
1790 avc_ss_reset(seqno);
1791 selnl_notify_policyload(seqno);
1792 }
1793 return rc;
1794}
1795
1796int security_get_bool_value(int bool)
1797{
1798 int rc = 0;
1799 int len;
1800
1801 POLICY_RDLOCK;
1802
1803 len = policydb.p_bools.nprim;
1804 if (bool >= len) {
1805 rc = -EFAULT;
1806 goto out;
1807 }
1808
1809 rc = policydb.bool_val_to_struct[bool]->state;
1810out:
1811 POLICY_RDUNLOCK;
1812 return rc;
1813}