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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / security / selinux / ss / services.c
blobea7c01f4a2bf8388f27beda3e8c33d25baf7914f
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 * Added support for the policy capability bitmap
20 *
21 * Updated: Chad Sellers <csellers@tresys.com>
22 *
23 * Added validation of kernel classes and permissions
24 *
25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26 *
27 * Added support for bounds domain and audit messaged on masked permissions
28 *
29 * Updated: Guido Trentalancia <guido@trentalancia.com>
30 *
31 * Added support for runtime switching of the policy type
32 *
33 * Copyright (C) 2008, 2009 NEC Corporation
34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38 * This program is free software; you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, version 2.
41 */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <linux/flex_array.h>
54 #include <linux/vmalloc.h>
55 #include <net/netlabel.h>
56
57 #include "flask.h"
58 #include "avc.h"
59 #include "avc_ss.h"
60 #include "security.h"
61 #include "context.h"
62 #include "policydb.h"
63 #include "sidtab.h"
64 #include "services.h"
65 #include "conditional.h"
66 #include "mls.h"
67 #include "objsec.h"
68 #include "netlabel.h"
69 #include "xfrm.h"
70 #include "ebitmap.h"
71 #include "audit.h"
72
73 extern void selnl_notify_policyload(u32 seqno);
74
75 int selinux_policycap_netpeer;
76 int selinux_policycap_openperm;
77
78 static DEFINE_RWLOCK(policy_rwlock);
79
80 static struct sidtab sidtab;
81 struct policydb policydb;
82 int ss_initialized;
83
84 /*
85 * The largest sequence number that has been used when
86 * providing an access decision to the access vector cache.
87 * The sequence number only changes when a policy change
88 * occurs.
89 */
90 static u32 latest_granting;
91
92 /* Forward declaration. */
93 static int context_struct_to_string(struct context *context, char **scontext,
94 u32 *scontext_len);
95
96 static void context_struct_compute_av(struct context *scontext,
97 struct context *tcontext,
98 u16 tclass,
99 struct av_decision *avd);
100
101 struct selinux_mapping {
102 u16 value; /* policy value */
103 unsigned num_perms;
104 u32 perms[sizeof(u32) * 8];
105 };
106
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109
110 static int selinux_set_mapping(struct policydb *pol,
111 struct security_class_mapping *map,
112 struct selinux_mapping **out_map_p,
113 u16 *out_map_size)
114 {
115 struct selinux_mapping *out_map = NULL;
116 size_t size = sizeof(struct selinux_mapping);
117 u16 i, j;
118 unsigned k;
119 bool print_unknown_handle = false;
120
121 /* Find number of classes in the input mapping */
122 if (!map)
123 return -EINVAL;
124 i = 0;
125 while (map[i].name)
126 i++;
127
128 /* Allocate space for the class records, plus one for class zero */
129 out_map = kcalloc(++i, size, GFP_ATOMIC);
130 if (!out_map)
131 return -ENOMEM;
132
133 /* Store the raw class and permission values */
134 j = 0;
135 while (map[j].name) {
136 struct security_class_mapping *p_in = map + (j++);
137 struct selinux_mapping *p_out = out_map + j;
138
139 /* An empty class string skips ahead */
140 if (!strcmp(p_in->name, "")) {
141 p_out->num_perms = 0;
142 continue;
143 }
144
145 p_out->value = string_to_security_class(pol, p_in->name);
146 if (!p_out->value) {
147 printk(KERN_INFO
148 "SELinux: Class %s not defined in policy.\n",
149 p_in->name);
150 if (pol->reject_unknown)
151 goto err;
152 p_out->num_perms = 0;
153 print_unknown_handle = true;
154 continue;
155 }
156
157 k = 0;
158 while (p_in->perms && p_in->perms[k]) {
159 /* An empty permission string skips ahead */
160 if (!*p_in->perms[k]) {
161 k++;
162 continue;
163 }
164 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165 p_in->perms[k]);
166 if (!p_out->perms[k]) {
167 printk(KERN_INFO
168 "SELinux: Permission %s in class %s not defined in policy.\n",
169 p_in->perms[k], p_in->name);
170 if (pol->reject_unknown)
171 goto err;
172 print_unknown_handle = true;
173 }
174
175 k++;
176 }
177 p_out->num_perms = k;
178 }
179
180 if (print_unknown_handle)
181 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182 pol->allow_unknown ? "allowed" : "denied");
183
184 *out_map_p = out_map;
185 *out_map_size = i;
186 return 0;
187 err:
188 kfree(out_map);
189 return -EINVAL;
190 }
191
192 /*
193 * Get real, policy values from mapped values
194 */
195
196 static u16 unmap_class(u16 tclass)
197 {
198 if (tclass < current_mapping_size)
199 return current_mapping[tclass].value;
200
201 return tclass;
202 }
203
204 /*
205 * Get kernel value for class from its policy value
206 */
207 static u16 map_class(u16 pol_value)
208 {
209 u16 i;
210
211 for (i = 1; i < current_mapping_size; i++) {
212 if (current_mapping[i].value == pol_value)
213 return i;
214 }
215
216 return SECCLASS_NULL;
217 }
218
219 static void map_decision(u16 tclass, struct av_decision *avd,
220 int allow_unknown)
221 {
222 if (tclass < current_mapping_size) {
223 unsigned i, n = current_mapping[tclass].num_perms;
224 u32 result;
225
226 for (i = 0, result = 0; i < n; i++) {
227 if (avd->allowed & current_mapping[tclass].perms[i])
228 result |= 1<<i;
229 if (allow_unknown && !current_mapping[tclass].perms[i])
230 result |= 1<<i;
231 }
232 avd->allowed = result;
233
234 for (i = 0, result = 0; i < n; i++)
235 if (avd->auditallow & current_mapping[tclass].perms[i])
236 result |= 1<<i;
237 avd->auditallow = result;
238
239 for (i = 0, result = 0; i < n; i++) {
240 if (avd->auditdeny & current_mapping[tclass].perms[i])
241 result |= 1<<i;
242 if (!allow_unknown && !current_mapping[tclass].perms[i])
243 result |= 1<<i;
244 }
245 /*
246 * In case the kernel has a bug and requests a permission
247 * between num_perms and the maximum permission number, we
248 * should audit that denial
249 */
250 for (; i < (sizeof(u32)*8); i++)
251 result |= 1<<i;
252 avd->auditdeny = result;
253 }
254 }
255
256 int security_mls_enabled(void)
257 {
258 return policydb.mls_enabled;
259 }
260
261 /*
262 * Return the boolean value of a constraint expression
263 * when it is applied to the specified source and target
264 * security contexts.
265 *
266 * xcontext is a special beast... It is used by the validatetrans rules
267 * only. For these rules, scontext is the context before the transition,
268 * tcontext is the context after the transition, and xcontext is the context
269 * of the process performing the transition. All other callers of
270 * constraint_expr_eval should pass in NULL for xcontext.
271 */
272 static int constraint_expr_eval(struct context *scontext,
273 struct context *tcontext,
274 struct context *xcontext,
275 struct constraint_expr *cexpr)
276 {
277 u32 val1, val2;
278 struct context *c;
279 struct role_datum *r1, *r2;
280 struct mls_level *l1, *l2;
281 struct constraint_expr *e;
282 int s[CEXPR_MAXDEPTH];
283 int sp = -1;
284
285 for (e = cexpr; e; e = e->next) {
286 switch (e->expr_type) {
287 case CEXPR_NOT:
288 BUG_ON(sp < 0);
289 s[sp] = !s[sp];
290 break;
291 case CEXPR_AND:
292 BUG_ON(sp < 1);
293 sp--;
294 s[sp] &= s[sp + 1];
295 break;
296 case CEXPR_OR:
297 BUG_ON(sp < 1);
298 sp--;
299 s[sp] |= s[sp + 1];
300 break;
301 case CEXPR_ATTR:
302 if (sp == (CEXPR_MAXDEPTH - 1))
303 return 0;
304 switch (e->attr) {
305 case CEXPR_USER:
306 val1 = scontext->user;
307 val2 = tcontext->user;
308 break;
309 case CEXPR_TYPE:
310 val1 = scontext->type;
311 val2 = tcontext->type;
312 break;
313 case CEXPR_ROLE:
314 val1 = scontext->role;
315 val2 = tcontext->role;
316 r1 = policydb.role_val_to_struct[val1 - 1];
317 r2 = policydb.role_val_to_struct[val2 - 1];
318 switch (e->op) {
319 case CEXPR_DOM:
320 s[++sp] = ebitmap_get_bit(&r1->dominates,
321 val2 - 1);
322 continue;
323 case CEXPR_DOMBY:
324 s[++sp] = ebitmap_get_bit(&r2->dominates,
325 val1 - 1);
326 continue;
327 case CEXPR_INCOMP:
328 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329 val2 - 1) &&
330 !ebitmap_get_bit(&r2->dominates,
331 val1 - 1));
332 continue;
333 default:
334 break;
335 }
336 break;
337 case CEXPR_L1L2:
338 l1 = &(scontext->range.level[0]);
339 l2 = &(tcontext->range.level[0]);
340 goto mls_ops;
341 case CEXPR_L1H2:
342 l1 = &(scontext->range.level[0]);
343 l2 = &(tcontext->range.level[1]);
344 goto mls_ops;
345 case CEXPR_H1L2:
346 l1 = &(scontext->range.level[1]);
347 l2 = &(tcontext->range.level[0]);
348 goto mls_ops;
349 case CEXPR_H1H2:
350 l1 = &(scontext->range.level[1]);
351 l2 = &(tcontext->range.level[1]);
352 goto mls_ops;
353 case CEXPR_L1H1:
354 l1 = &(scontext->range.level[0]);
355 l2 = &(scontext->range.level[1]);
356 goto mls_ops;
357 case CEXPR_L2H2:
358 l1 = &(tcontext->range.level[0]);
359 l2 = &(tcontext->range.level[1]);
360 goto mls_ops;
361 mls_ops:
362 switch (e->op) {
363 case CEXPR_EQ:
364 s[++sp] = mls_level_eq(l1, l2);
365 continue;
366 case CEXPR_NEQ:
367 s[++sp] = !mls_level_eq(l1, l2);
368 continue;
369 case CEXPR_DOM:
370 s[++sp] = mls_level_dom(l1, l2);
371 continue;
372 case CEXPR_DOMBY:
373 s[++sp] = mls_level_dom(l2, l1);
374 continue;
375 case CEXPR_INCOMP:
376 s[++sp] = mls_level_incomp(l2, l1);
377 continue;
378 default:
379 BUG();
380 return 0;
381 }
382 break;
383 default:
384 BUG();
385 return 0;
386 }
387
388 switch (e->op) {
389 case CEXPR_EQ:
390 s[++sp] = (val1 == val2);
391 break;
392 case CEXPR_NEQ:
393 s[++sp] = (val1 != val2);
394 break;
395 default:
396 BUG();
397 return 0;
398 }
399 break;
400 case CEXPR_NAMES:
401 if (sp == (CEXPR_MAXDEPTH-1))
402 return 0;
403 c = scontext;
404 if (e->attr & CEXPR_TARGET)
405 c = tcontext;
406 else if (e->attr & CEXPR_XTARGET) {
407 c = xcontext;
408 if (!c) {
409 BUG();
410 return 0;
411 }
412 }
413 if (e->attr & CEXPR_USER)
414 val1 = c->user;
415 else if (e->attr & CEXPR_ROLE)
416 val1 = c->role;
417 else if (e->attr & CEXPR_TYPE)
418 val1 = c->type;
419 else {
420 BUG();
421 return 0;
422 }
423
424 switch (e->op) {
425 case CEXPR_EQ:
426 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427 break;
428 case CEXPR_NEQ:
429 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430 break;
431 default:
432 BUG();
433 return 0;
434 }
435 break;
436 default:
437 BUG();
438 return 0;
439 }
440 }
441
442 BUG_ON(sp != 0);
443 return s[0];
444 }
445
446 /*
447 * security_dump_masked_av - dumps masked permissions during
448 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449 */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452 struct perm_datum *pdatum = d;
453 char **permission_names = args;
454
455 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456
457 permission_names[pdatum->value - 1] = (char *)k;
458
459 return 0;
460 }
461
462 static void security_dump_masked_av(struct context *scontext,
463 struct context *tcontext,
464 u16 tclass,
465 u32 permissions,
466 const char *reason)
467 {
468 struct common_datum *common_dat;
469 struct class_datum *tclass_dat;
470 struct audit_buffer *ab;
471 char *tclass_name;
472 char *scontext_name = NULL;
473 char *tcontext_name = NULL;
474 char *permission_names[32];
475 int index;
476 u32 length;
477 bool need_comma = false;
478
479 if (!permissions)
480 return;
481
482 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483 tclass_dat = policydb.class_val_to_struct[tclass - 1];
484 common_dat = tclass_dat->comdatum;
485
486 /* init permission_names */
487 if (common_dat &&
488 hashtab_map(common_dat->permissions.table,
489 dump_masked_av_helper, permission_names) < 0)
490 goto out;
491
492 if (hashtab_map(tclass_dat->permissions.table,
493 dump_masked_av_helper, permission_names) < 0)
494 goto out;
495
496 /* get scontext/tcontext in text form */
497 if (context_struct_to_string(scontext,
498 &scontext_name, &length) < 0)
499 goto out;
500
501 if (context_struct_to_string(tcontext,
502 &tcontext_name, &length) < 0)
503 goto out;
504
505 /* audit a message */
506 ab = audit_log_start(current->audit_context,
507 GFP_ATOMIC, AUDIT_SELINUX_ERR);
508 if (!ab)
509 goto out;
510
511 audit_log_format(ab, "op=security_compute_av reason=%s "
512 "scontext=%s tcontext=%s tclass=%s perms=",
513 reason, scontext_name, tcontext_name, tclass_name);
514
515 for (index = 0; index < 32; index++) {
516 u32 mask = (1 << index);
517
518 if ((mask & permissions) == 0)
519 continue;
520
521 audit_log_format(ab, "%s%s",
522 need_comma ? "," : "",
523 permission_names[index]
524 ? permission_names[index] : "????");
525 need_comma = true;
526 }
527 audit_log_end(ab);
528 out:
529 /* release scontext/tcontext */
530 kfree(tcontext_name);
531 kfree(scontext_name);
532
533 return;
534 }
535
536 /*
537 * security_boundary_permission - drops violated permissions
538 * on boundary constraint.
539 */
540 static void type_attribute_bounds_av(struct context *scontext,
541 struct context *tcontext,
542 u16 tclass,
543 struct av_decision *avd)
544 {
545 struct context lo_scontext;
546 struct context lo_tcontext;
547 struct av_decision lo_avd;
548 struct type_datum *source;
549 struct type_datum *target;
550 u32 masked = 0;
551
552 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553 scontext->type - 1);
554 BUG_ON(!source);
555
556 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557 tcontext->type - 1);
558 BUG_ON(!target);
559
560 if (source->bounds) {
561 memset(&lo_avd, 0, sizeof(lo_avd));
562
563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564 lo_scontext.type = source->bounds;
565
566 context_struct_compute_av(&lo_scontext,
567 tcontext,
568 tclass,
569 &lo_avd);
570 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
571 return; /* no masked permission */
572 masked = ~lo_avd.allowed & avd->allowed;
573 }
574
575 if (target->bounds) {
576 memset(&lo_avd, 0, sizeof(lo_avd));
577
578 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
579 lo_tcontext.type = target->bounds;
580
581 context_struct_compute_av(scontext,
582 &lo_tcontext,
583 tclass,
584 &lo_avd);
585 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
586 return; /* no masked permission */
587 masked = ~lo_avd.allowed & avd->allowed;
588 }
589
590 if (source->bounds && target->bounds) {
591 memset(&lo_avd, 0, sizeof(lo_avd));
592 /*
593 * lo_scontext and lo_tcontext are already
594 * set up.
595 */
596
597 context_struct_compute_av(&lo_scontext,
598 &lo_tcontext,
599 tclass,
600 &lo_avd);
601 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
602 return; /* no masked permission */
603 masked = ~lo_avd.allowed & avd->allowed;
604 }
605
606 if (masked) {
607 /* mask violated permissions */
608 avd->allowed &= ~masked;
609
610 /* audit masked permissions */
611 security_dump_masked_av(scontext, tcontext,
612 tclass, masked, "bounds");
613 }
614 }
615
616 /*
617 * Compute access vectors based on a context structure pair for
618 * the permissions in a particular class.
619 */
620 static void context_struct_compute_av(struct context *scontext,
621 struct context *tcontext,
622 u16 tclass,
623 struct av_decision *avd)
624 {
625 struct constraint_node *constraint;
626 struct role_allow *ra;
627 struct avtab_key avkey;
628 struct avtab_node *node;
629 struct class_datum *tclass_datum;
630 struct ebitmap *sattr, *tattr;
631 struct ebitmap_node *snode, *tnode;
632 unsigned int i, j;
633
634 avd->allowed = 0;
635 avd->auditallow = 0;
636 avd->auditdeny = 0xffffffff;
637
638 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
639 if (printk_ratelimit())
640 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
641 return;
642 }
643
644 tclass_datum = policydb.class_val_to_struct[tclass - 1];
645
646 /*
647 * If a specific type enforcement rule was defined for
648 * this permission check, then use it.
649 */
650 avkey.target_class = tclass;
651 avkey.specified = AVTAB_AV;
652 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
653 BUG_ON(!sattr);
654 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
655 BUG_ON(!tattr);
656 ebitmap_for_each_positive_bit(sattr, snode, i) {
657 ebitmap_for_each_positive_bit(tattr, tnode, j) {
658 avkey.source_type = i + 1;
659 avkey.target_type = j + 1;
660 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
661 node;
662 node = avtab_search_node_next(node, avkey.specified)) {
663 if (node->key.specified == AVTAB_ALLOWED)
664 avd->allowed |= node->datum.data;
665 else if (node->key.specified == AVTAB_AUDITALLOW)
666 avd->auditallow |= node->datum.data;
667 else if (node->key.specified == AVTAB_AUDITDENY)
668 avd->auditdeny &= node->datum.data;
669 }
670
671 /* Check conditional av table for additional permissions */
672 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
673
674 }
675 }
676
677 /*
678 * Remove any permissions prohibited by a constraint (this includes
679 * the MLS policy).
680 */
681 constraint = tclass_datum->constraints;
682 while (constraint) {
683 if ((constraint->permissions & (avd->allowed)) &&
684 !constraint_expr_eval(scontext, tcontext, NULL,
685 constraint->expr)) {
686 avd->allowed &= ~(constraint->permissions);
687 }
688 constraint = constraint->next;
689 }
690
691 /*
692 * If checking process transition permission and the
693 * role is changing, then check the (current_role, new_role)
694 * pair.
695 */
696 if (tclass == policydb.process_class &&
697 (avd->allowed & policydb.process_trans_perms) &&
698 scontext->role != tcontext->role) {
699 for (ra = policydb.role_allow; ra; ra = ra->next) {
700 if (scontext->role == ra->role &&
701 tcontext->role == ra->new_role)
702 break;
703 }
704 if (!ra)
705 avd->allowed &= ~policydb.process_trans_perms;
706 }
707
708 /*
709 * If the given source and target types have boundary
710 * constraint, lazy checks have to mask any violated
711 * permission and notice it to userspace via audit.
712 */
713 type_attribute_bounds_av(scontext, tcontext,
714 tclass, avd);
715 }
716
717 static int security_validtrans_handle_fail(struct context *ocontext,
718 struct context *ncontext,
719 struct context *tcontext,
720 u16 tclass)
721 {
722 char *o = NULL, *n = NULL, *t = NULL;
723 u32 olen, nlen, tlen;
724
725 if (context_struct_to_string(ocontext, &o, &olen))
726 goto out;
727 if (context_struct_to_string(ncontext, &n, &nlen))
728 goto out;
729 if (context_struct_to_string(tcontext, &t, &tlen))
730 goto out;
731 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
732 "security_validate_transition: denied for"
733 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
734 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
735 out:
736 kfree(o);
737 kfree(n);
738 kfree(t);
739
740 if (!selinux_enforcing)
741 return 0;
742 return -EPERM;
743 }
744
745 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
746 u16 orig_tclass)
747 {
748 struct context *ocontext;
749 struct context *ncontext;
750 struct context *tcontext;
751 struct class_datum *tclass_datum;
752 struct constraint_node *constraint;
753 u16 tclass;
754 int rc = 0;
755
756 if (!ss_initialized)
757 return 0;
758
759 read_lock(&policy_rwlock);
760
761 tclass = unmap_class(orig_tclass);
762
763 if (!tclass || tclass > policydb.p_classes.nprim) {
764 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
765 __func__, tclass);
766 rc = -EINVAL;
767 goto out;
768 }
769 tclass_datum = policydb.class_val_to_struct[tclass - 1];
770
771 ocontext = sidtab_search(&sidtab, oldsid);
772 if (!ocontext) {
773 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
774 __func__, oldsid);
775 rc = -EINVAL;
776 goto out;
777 }
778
779 ncontext = sidtab_search(&sidtab, newsid);
780 if (!ncontext) {
781 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
782 __func__, newsid);
783 rc = -EINVAL;
784 goto out;
785 }
786
787 tcontext = sidtab_search(&sidtab, tasksid);
788 if (!tcontext) {
789 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
790 __func__, tasksid);
791 rc = -EINVAL;
792 goto out;
793 }
794
795 constraint = tclass_datum->validatetrans;
796 while (constraint) {
797 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
798 constraint->expr)) {
799 rc = security_validtrans_handle_fail(ocontext, ncontext,
800 tcontext, tclass);
801 goto out;
802 }
803 constraint = constraint->next;
804 }
805
806 out:
807 read_unlock(&policy_rwlock);
808 return rc;
809 }
810
811 /*
812 * security_bounded_transition - check whether the given
813 * transition is directed to bounded, or not.
814 * It returns 0, if @newsid is bounded by @oldsid.
815 * Otherwise, it returns error code.
816 *
817 * @oldsid : current security identifier
818 * @newsid : destinated security identifier
819 */
820 int security_bounded_transition(u32 old_sid, u32 new_sid)
821 {
822 struct context *old_context, *new_context;
823 struct type_datum *type;
824 int index;
825 int rc;
826
827 read_lock(&policy_rwlock);
828
829 rc = -EINVAL;
830 old_context = sidtab_search(&sidtab, old_sid);
831 if (!old_context) {
832 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
833 __func__, old_sid);
834 goto out;
835 }
836
837 rc = -EINVAL;
838 new_context = sidtab_search(&sidtab, new_sid);
839 if (!new_context) {
840 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
841 __func__, new_sid);
842 goto out;
843 }
844
845 rc = 0;
846 /* type/domain unchanged */
847 if (old_context->type == new_context->type)
848 goto out;
849
850 index = new_context->type;
851 while (true) {
852 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
853 index - 1);
854 BUG_ON(!type);
855
856 /* not bounded anymore */
857 rc = -EPERM;
858 if (!type->bounds)
859 break;
860
861 /* @newsid is bounded by @oldsid */
862 rc = 0;
863 if (type->bounds == old_context->type)
864 break;
865
866 index = type->bounds;
867 }
868
869 if (rc) {
870 char *old_name = NULL;
871 char *new_name = NULL;
872 u32 length;
873
874 if (!context_struct_to_string(old_context,
875 &old_name, &length) &&
876 !context_struct_to_string(new_context,
877 &new_name, &length)) {
878 audit_log(current->audit_context,
879 GFP_ATOMIC, AUDIT_SELINUX_ERR,
880 "op=security_bounded_transition "
881 "result=denied "
882 "oldcontext=%s newcontext=%s",
883 old_name, new_name);
884 }
885 kfree(new_name);
886 kfree(old_name);
887 }
888 out:
889 read_unlock(&policy_rwlock);
890
891 return rc;
892 }
893
894 static void avd_init(struct av_decision *avd)
895 {
896 avd->allowed = 0;
897 avd->auditallow = 0;
898 avd->auditdeny = 0xffffffff;
899 avd->seqno = latest_granting;
900 avd->flags = 0;
901 }
902
903
904 /**
905 * security_compute_av - Compute access vector decisions.
906 * @ssid: source security identifier
907 * @tsid: target security identifier
908 * @tclass: target security class
909 * @avd: access vector decisions
910 *
911 * Compute a set of access vector decisions based on the
912 * SID pair (@ssid, @tsid) for the permissions in @tclass.
913 */
914 void security_compute_av(u32 ssid,
915 u32 tsid,
916 u16 orig_tclass,
917 struct av_decision *avd)
918 {
919 u16 tclass;
920 struct context *scontext = NULL, *tcontext = NULL;
921
922 read_lock(&policy_rwlock);
923 avd_init(avd);
924 if (!ss_initialized)
925 goto allow;
926
927 scontext = sidtab_search(&sidtab, ssid);
928 if (!scontext) {
929 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
930 __func__, ssid);
931 goto out;
932 }
933
934 /* permissive domain? */
935 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
936 avd->flags |= AVD_FLAGS_PERMISSIVE;
937
938 tcontext = sidtab_search(&sidtab, tsid);
939 if (!tcontext) {
940 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
941 __func__, tsid);
942 goto out;
943 }
944
945 tclass = unmap_class(orig_tclass);
946 if (unlikely(orig_tclass && !tclass)) {
947 if (policydb.allow_unknown)
948 goto allow;
949 goto out;
950 }
951 context_struct_compute_av(scontext, tcontext, tclass, avd);
952 map_decision(orig_tclass, avd, policydb.allow_unknown);
953 out:
954 read_unlock(&policy_rwlock);
955 return;
956 allow:
957 avd->allowed = 0xffffffff;
958 goto out;
959 }
960
961 void security_compute_av_user(u32 ssid,
962 u32 tsid,
963 u16 tclass,
964 struct av_decision *avd)
965 {
966 struct context *scontext = NULL, *tcontext = NULL;
967
968 read_lock(&policy_rwlock);
969 avd_init(avd);
970 if (!ss_initialized)
971 goto allow;
972
973 scontext = sidtab_search(&sidtab, ssid);
974 if (!scontext) {
975 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
976 __func__, ssid);
977 goto out;
978 }
979
980 /* permissive domain? */
981 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
982 avd->flags |= AVD_FLAGS_PERMISSIVE;
983
984 tcontext = sidtab_search(&sidtab, tsid);
985 if (!tcontext) {
986 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
987 __func__, tsid);
988 goto out;
989 }
990
991 if (unlikely(!tclass)) {
992 if (policydb.allow_unknown)
993 goto allow;
994 goto out;
995 }
996
997 context_struct_compute_av(scontext, tcontext, tclass, avd);
998 out:
999 read_unlock(&policy_rwlock);
1000 return;
1001 allow:
1002 avd->allowed = 0xffffffff;
1003 goto out;
1004 }
1005
1006 /*
1007 * Write the security context string representation of
1008 * the context structure `context' into a dynamically
1009 * allocated string of the correct size. Set `*scontext'
1010 * to point to this string and set `*scontext_len' to
1011 * the length of the string.
1012 */
1013 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1014 {
1015 char *scontextp;
1016
1017 if (scontext)
1018 *scontext = NULL;
1019 *scontext_len = 0;
1020
1021 if (context->len) {
1022 *scontext_len = context->len;
1023 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024 if (!(*scontext))
1025 return -ENOMEM;
1026 return 0;
1027 }
1028
1029 /* Compute the size of the context. */
1030 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033 *scontext_len += mls_compute_context_len(context);
1034
1035 if (!scontext)
1036 return 0;
1037
1038 /* Allocate space for the context; caller must free this space. */
1039 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040 if (!scontextp)
1041 return -ENOMEM;
1042 *scontext = scontextp;
1043
1044 /*
1045 * Copy the user name, role name and type name into the context.
1046 */
1047 sprintf(scontextp, "%s:%s:%s",
1048 sym_name(&policydb, SYM_USERS, context->user - 1),
1049 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054
1055 mls_sid_to_context(context, &scontextp);
1056
1057 *scontextp = 0;
1058
1059 return 0;
1060 }
1061
1062 #include "initial_sid_to_string.h"
1063
1064 const char *security_get_initial_sid_context(u32 sid)
1065 {
1066 if (unlikely(sid > SECINITSID_NUM))
1067 return NULL;
1068 return initial_sid_to_string[sid];
1069 }
1070
1071 static int security_sid_to_context_core(u32 sid, char **scontext,
1072 u32 *scontext_len, int force)
1073 {
1074 struct context *context;
1075 int rc = 0;
1076
1077 if (scontext)
1078 *scontext = NULL;
1079 *scontext_len = 0;
1080
1081 if (!ss_initialized) {
1082 if (sid <= SECINITSID_NUM) {
1083 char *scontextp;
1084
1085 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086 if (!scontext)
1087 goto out;
1088 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089 if (!scontextp) {
1090 rc = -ENOMEM;
1091 goto out;
1092 }
1093 strcpy(scontextp, initial_sid_to_string[sid]);
1094 *scontext = scontextp;
1095 goto out;
1096 }
1097 printk(KERN_ERR "SELinux: %s: called before initial "
1098 "load_policy on unknown SID %d\n", __func__, sid);
1099 rc = -EINVAL;
1100 goto out;
1101 }
1102 read_lock(&policy_rwlock);
1103 if (force)
1104 context = sidtab_search_force(&sidtab, sid);
1105 else
1106 context = sidtab_search(&sidtab, sid);
1107 if (!context) {
1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1109 __func__, sid);
1110 rc = -EINVAL;
1111 goto out_unlock;
1112 }
1113 rc = context_struct_to_string(context, scontext, scontext_len);
1114 out_unlock:
1115 read_unlock(&policy_rwlock);
1116 out:
1117 return rc;
1118
1119 }
1120
1121 /**
1122 * security_sid_to_context - Obtain a context for a given SID.
1123 * @sid: security identifier, SID
1124 * @scontext: security context
1125 * @scontext_len: length in bytes
1126 *
1127 * Write the string representation of the context associated with @sid
1128 * into a dynamically allocated string of the correct size. Set @scontext
1129 * to point to this string and set @scontext_len to the length of the string.
1130 */
1131 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132 {
1133 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134 }
1135
1136 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137 {
1138 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139 }
1140
1141 /*
1142 * Caveat: Mutates scontext.
1143 */
1144 static int string_to_context_struct(struct policydb *pol,
1145 struct sidtab *sidtabp,
1146 char *scontext,
1147 u32 scontext_len,
1148 struct context *ctx,
1149 u32 def_sid)
1150 {
1151 struct role_datum *role;
1152 struct type_datum *typdatum;
1153 struct user_datum *usrdatum;
1154 char *scontextp, *p, oldc;
1155 int rc = 0;
1156
1157 context_init(ctx);
1158
1159 /* Parse the security context. */
1160
1161 rc = -EINVAL;
1162 scontextp = (char *) scontext;
1163
1164 /* Extract the user. */
1165 p = scontextp;
1166 while (*p && *p != ':')
1167 p++;
1168
1169 if (*p == 0)
1170 goto out;
1171
1172 *p++ = 0;
1173
1174 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175 if (!usrdatum)
1176 goto out;
1177
1178 ctx->user = usrdatum->value;
1179
1180 /* Extract role. */
1181 scontextp = p;
1182 while (*p && *p != ':')
1183 p++;
1184
1185 if (*p == 0)
1186 goto out;
1187
1188 *p++ = 0;
1189
1190 role = hashtab_search(pol->p_roles.table, scontextp);
1191 if (!role)
1192 goto out;
1193 ctx->role = role->value;
1194
1195 /* Extract type. */
1196 scontextp = p;
1197 while (*p && *p != ':')
1198 p++;
1199 oldc = *p;
1200 *p++ = 0;
1201
1202 typdatum = hashtab_search(pol->p_types.table, scontextp);
1203 if (!typdatum || typdatum->attribute)
1204 goto out;
1205
1206 ctx->type = typdatum->value;
1207
1208 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209 if (rc)
1210 goto out;
1211
1212 rc = -EINVAL;
1213 if ((p - scontext) < scontext_len)
1214 goto out;
1215
1216 /* Check the validity of the new context. */
1217 if (!policydb_context_isvalid(pol, ctx))
1218 goto out;
1219 rc = 0;
1220 out:
1221 if (rc)
1222 context_destroy(ctx);
1223 return rc;
1224 }
1225
1226 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228 int force)
1229 {
1230 char *scontext2, *str = NULL;
1231 struct context context;
1232 int rc = 0;
1233
1234 if (!ss_initialized) {
1235 int i;
1236
1237 for (i = 1; i < SECINITSID_NUM; i++) {
1238 if (!strcmp(initial_sid_to_string[i], scontext)) {
1239 *sid = i;
1240 return 0;
1241 }
1242 }
1243 *sid = SECINITSID_KERNEL;
1244 return 0;
1245 }
1246 *sid = SECSID_NULL;
1247
1248 /* Copy the string so that we can modify the copy as we parse it. */
1249 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1250 if (!scontext2)
1251 return -ENOMEM;
1252 memcpy(scontext2, scontext, scontext_len);
1253 scontext2[scontext_len] = 0;
1254
1255 if (force) {
1256 /* Save another copy for storing in uninterpreted form */
1257 rc = -ENOMEM;
1258 str = kstrdup(scontext2, gfp_flags);
1259 if (!str)
1260 goto out;
1261 }
1262
1263 read_lock(&policy_rwlock);
1264 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1265 scontext_len, &context, def_sid);
1266 if (rc == -EINVAL && force) {
1267 context.str = str;
1268 context.len = scontext_len;
1269 str = NULL;
1270 } else if (rc)
1271 goto out_unlock;
1272 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1273 context_destroy(&context);
1274 out_unlock:
1275 read_unlock(&policy_rwlock);
1276 out:
1277 kfree(scontext2);
1278 kfree(str);
1279 return rc;
1280 }
1281
1282 /**
1283 * security_context_to_sid - Obtain a SID for a given security context.
1284 * @scontext: security context
1285 * @scontext_len: length in bytes
1286 * @sid: security identifier, SID
1287 *
1288 * Obtains a SID associated with the security context that
1289 * has the string representation specified by @scontext.
1290 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1291 * memory is available, or 0 on success.
1292 */
1293 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1294 {
1295 return security_context_to_sid_core(scontext, scontext_len,
1296 sid, SECSID_NULL, GFP_KERNEL, 0);
1297 }
1298
1299 /**
1300 * security_context_to_sid_default - Obtain a SID for a given security context,
1301 * falling back to specified default if needed.
1302 *
1303 * @scontext: security context
1304 * @scontext_len: length in bytes
1305 * @sid: security identifier, SID
1306 * @def_sid: default SID to assign on error
1307 *
1308 * Obtains a SID associated with the security context that
1309 * has the string representation specified by @scontext.
1310 * The default SID is passed to the MLS layer to be used to allow
1311 * kernel labeling of the MLS field if the MLS field is not present
1312 * (for upgrading to MLS without full relabel).
1313 * Implicitly forces adding of the context even if it cannot be mapped yet.
1314 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1315 * memory is available, or 0 on success.
1316 */
1317 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1318 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1319 {
1320 return security_context_to_sid_core(scontext, scontext_len,
1321 sid, def_sid, gfp_flags, 1);
1322 }
1323
1324 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1325 u32 *sid)
1326 {
1327 return security_context_to_sid_core(scontext, scontext_len,
1328 sid, SECSID_NULL, GFP_KERNEL, 1);
1329 }
1330
1331 static int compute_sid_handle_invalid_context(
1332 struct context *scontext,
1333 struct context *tcontext,
1334 u16 tclass,
1335 struct context *newcontext)
1336 {
1337 char *s = NULL, *t = NULL, *n = NULL;
1338 u32 slen, tlen, nlen;
1339
1340 if (context_struct_to_string(scontext, &s, &slen))
1341 goto out;
1342 if (context_struct_to_string(tcontext, &t, &tlen))
1343 goto out;
1344 if (context_struct_to_string(newcontext, &n, &nlen))
1345 goto out;
1346 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1347 "security_compute_sid: invalid context %s"
1348 " for scontext=%s"
1349 " tcontext=%s"
1350 " tclass=%s",
1351 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1352 out:
1353 kfree(s);
1354 kfree(t);
1355 kfree(n);
1356 if (!selinux_enforcing)
1357 return 0;
1358 return -EACCES;
1359 }
1360
1361 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1362 u32 scon, u32 tcon, u16 tclass,
1363 const struct qstr *qstr)
1364 {
1365 struct filename_trans *ft;
1366 for (ft = p->filename_trans; ft; ft = ft->next) {
1367 if (ft->stype == scon &&
1368 ft->ttype == tcon &&
1369 ft->tclass == tclass &&
1370 !strcmp(ft->name, qstr->name)) {
1371 newcontext->type = ft->otype;
1372 return;
1373 }
1374 }
1375 }
1376
1377 static int security_compute_sid(u32 ssid,
1378 u32 tsid,
1379 u16 orig_tclass,
1380 u32 specified,
1381 const struct qstr *qstr,
1382 u32 *out_sid,
1383 bool kern)
1384 {
1385 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1386 struct role_trans *roletr = NULL;
1387 struct avtab_key avkey;
1388 struct avtab_datum *avdatum;
1389 struct avtab_node *node;
1390 u16 tclass;
1391 int rc = 0;
1392 bool sock;
1393
1394 if (!ss_initialized) {
1395 switch (orig_tclass) {
1396 case SECCLASS_PROCESS: /* kernel value */
1397 *out_sid = ssid;
1398 break;
1399 default:
1400 *out_sid = tsid;
1401 break;
1402 }
1403 goto out;
1404 }
1405
1406 context_init(&newcontext);
1407
1408 read_lock(&policy_rwlock);
1409
1410 if (kern) {
1411 tclass = unmap_class(orig_tclass);
1412 sock = security_is_socket_class(orig_tclass);
1413 } else {
1414 tclass = orig_tclass;
1415 sock = security_is_socket_class(map_class(tclass));
1416 }
1417
1418 scontext = sidtab_search(&sidtab, ssid);
1419 if (!scontext) {
1420 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1421 __func__, ssid);
1422 rc = -EINVAL;
1423 goto out_unlock;
1424 }
1425 tcontext = sidtab_search(&sidtab, tsid);
1426 if (!tcontext) {
1427 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1428 __func__, tsid);
1429 rc = -EINVAL;
1430 goto out_unlock;
1431 }
1432
1433 /* Set the user identity. */
1434 switch (specified) {
1435 case AVTAB_TRANSITION:
1436 case AVTAB_CHANGE:
1437 /* Use the process user identity. */
1438 newcontext.user = scontext->user;
1439 break;
1440 case AVTAB_MEMBER:
1441 /* Use the related object owner. */
1442 newcontext.user = tcontext->user;
1443 break;
1444 }
1445
1446 /* Set the role and type to default values. */
1447 if ((tclass == policydb.process_class) || (sock == true)) {
1448 /* Use the current role and type of process. */
1449 newcontext.role = scontext->role;
1450 newcontext.type = scontext->type;
1451 } else {
1452 /* Use the well-defined object role. */
1453 newcontext.role = OBJECT_R_VAL;
1454 /* Use the type of the related object. */
1455 newcontext.type = tcontext->type;
1456 }
1457
1458 /* Look for a type transition/member/change rule. */
1459 avkey.source_type = scontext->type;
1460 avkey.target_type = tcontext->type;
1461 avkey.target_class = tclass;
1462 avkey.specified = specified;
1463 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1464
1465 /* If no permanent rule, also check for enabled conditional rules */
1466 if (!avdatum) {
1467 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1468 for (; node; node = avtab_search_node_next(node, specified)) {
1469 if (node->key.specified & AVTAB_ENABLED) {
1470 avdatum = &node->datum;
1471 break;
1472 }
1473 }
1474 }
1475
1476 if (avdatum) {
1477 /* Use the type from the type transition/member/change rule. */
1478 newcontext.type = avdatum->data;
1479 }
1480
1481 /* if we have a qstr this is a file trans check so check those rules */
1482 if (qstr)
1483 filename_compute_type(&policydb, &newcontext, scontext->type,
1484 tcontext->type, tclass, qstr);
1485
1486 /* Check for class-specific changes. */
1487 if (tclass == policydb.process_class) {
1488 if (specified & AVTAB_TRANSITION) {
1489 /* Look for a role transition rule. */
1490 for (roletr = policydb.role_tr; roletr;
1491 roletr = roletr->next) {
1492 if (roletr->role == scontext->role &&
1493 roletr->type == tcontext->type) {
1494 /* Use the role transition rule. */
1495 newcontext.role = roletr->new_role;
1496 break;
1497 }
1498 }
1499 }
1500 }
1501
1502 /* Set the MLS attributes.
1503 This is done last because it may allocate memory. */
1504 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1505 &newcontext, sock);
1506 if (rc)
1507 goto out_unlock;
1508
1509 /* Check the validity of the context. */
1510 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1511 rc = compute_sid_handle_invalid_context(scontext,
1512 tcontext,
1513 tclass,
1514 &newcontext);
1515 if (rc)
1516 goto out_unlock;
1517 }
1518 /* Obtain the sid for the context. */
1519 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1520 out_unlock:
1521 read_unlock(&policy_rwlock);
1522 context_destroy(&newcontext);
1523 out:
1524 return rc;
1525 }
1526
1527 /**
1528 * security_transition_sid - Compute the SID for a new subject/object.
1529 * @ssid: source security identifier
1530 * @tsid: target security identifier
1531 * @tclass: target security class
1532 * @out_sid: security identifier for new subject/object
1533 *
1534 * Compute a SID to use for labeling a new subject or object in the
1535 * class @tclass based on a SID pair (@ssid, @tsid).
1536 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1537 * if insufficient memory is available, or %0 if the new SID was
1538 * computed successfully.
1539 */
1540 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1541 const struct qstr *qstr, u32 *out_sid)
1542 {
1543 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1544 qstr, out_sid, true);
1545 }
1546
1547 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid)
1548 {
1549 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1550 NULL, out_sid, false);
1551 }
1552
1553 /**
1554 * security_member_sid - Compute the SID for member selection.
1555 * @ssid: source security identifier
1556 * @tsid: target security identifier
1557 * @tclass: target security class
1558 * @out_sid: security identifier for selected member
1559 *
1560 * Compute a SID to use when selecting a member of a polyinstantiated
1561 * object of class @tclass based on a SID pair (@ssid, @tsid).
1562 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1563 * if insufficient memory is available, or %0 if the SID was
1564 * computed successfully.
1565 */
1566 int security_member_sid(u32 ssid,
1567 u32 tsid,
1568 u16 tclass,
1569 u32 *out_sid)
1570 {
1571 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1572 out_sid, false);
1573 }
1574
1575 /**
1576 * security_change_sid - Compute the SID for object relabeling.
1577 * @ssid: source security identifier
1578 * @tsid: target security identifier
1579 * @tclass: target security class
1580 * @out_sid: security identifier for selected member
1581 *
1582 * Compute a SID to use for relabeling an object of class @tclass
1583 * based on a SID pair (@ssid, @tsid).
1584 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1585 * if insufficient memory is available, or %0 if the SID was
1586 * computed successfully.
1587 */
1588 int security_change_sid(u32 ssid,
1589 u32 tsid,
1590 u16 tclass,
1591 u32 *out_sid)
1592 {
1593 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1594 out_sid, false);
1595 }
1596
1597 /* Clone the SID into the new SID table. */
1598 static int clone_sid(u32 sid,
1599 struct context *context,
1600 void *arg)
1601 {
1602 struct sidtab *s = arg;
1603
1604 if (sid > SECINITSID_NUM)
1605 return sidtab_insert(s, sid, context);
1606 else
1607 return 0;
1608 }
1609
1610 static inline int convert_context_handle_invalid_context(struct context *context)
1611 {
1612 char *s;
1613 u32 len;
1614
1615 if (selinux_enforcing)
1616 return -EINVAL;
1617
1618 if (!context_struct_to_string(context, &s, &len)) {
1619 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1620 kfree(s);
1621 }
1622 return 0;
1623 }
1624
1625 struct convert_context_args {
1626 struct policydb *oldp;
1627 struct policydb *newp;
1628 };
1629
1630 /*
1631 * Convert the values in the security context
1632 * structure `c' from the values specified
1633 * in the policy `p->oldp' to the values specified
1634 * in the policy `p->newp'. Verify that the
1635 * context is valid under the new policy.
1636 */
1637 static int convert_context(u32 key,
1638 struct context *c,
1639 void *p)
1640 {
1641 struct convert_context_args *args;
1642 struct context oldc;
1643 struct ocontext *oc;
1644 struct mls_range *range;
1645 struct role_datum *role;
1646 struct type_datum *typdatum;
1647 struct user_datum *usrdatum;
1648 char *s;
1649 u32 len;
1650 int rc = 0;
1651
1652 if (key <= SECINITSID_NUM)
1653 goto out;
1654
1655 args = p;
1656
1657 if (c->str) {
1658 struct context ctx;
1659
1660 rc = -ENOMEM;
1661 s = kstrdup(c->str, GFP_KERNEL);
1662 if (!s)
1663 goto out;
1664
1665 rc = string_to_context_struct(args->newp, NULL, s,
1666 c->len, &ctx, SECSID_NULL);
1667 kfree(s);
1668 if (!rc) {
1669 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1670 c->str);
1671 /* Replace string with mapped representation. */
1672 kfree(c->str);
1673 memcpy(c, &ctx, sizeof(*c));
1674 goto out;
1675 } else if (rc == -EINVAL) {
1676 /* Retain string representation for later mapping. */
1677 rc = 0;
1678 goto out;
1679 } else {
1680 /* Other error condition, e.g. ENOMEM. */
1681 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1682 c->str, -rc);
1683 goto out;
1684 }
1685 }
1686
1687 rc = context_cpy(&oldc, c);
1688 if (rc)
1689 goto out;
1690
1691 /* Convert the user. */
1692 rc = -EINVAL;
1693 usrdatum = hashtab_search(args->newp->p_users.table,
1694 sym_name(args->oldp, SYM_USERS, c->user - 1));
1695 if (!usrdatum)
1696 goto bad;
1697 c->user = usrdatum->value;
1698
1699 /* Convert the role. */
1700 rc = -EINVAL;
1701 role = hashtab_search(args->newp->p_roles.table,
1702 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1703 if (!role)
1704 goto bad;
1705 c->role = role->value;
1706
1707 /* Convert the type. */
1708 rc = -EINVAL;
1709 typdatum = hashtab_search(args->newp->p_types.table,
1710 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1711 if (!typdatum)
1712 goto bad;
1713 c->type = typdatum->value;
1714
1715 /* Convert the MLS fields if dealing with MLS policies */
1716 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1717 rc = mls_convert_context(args->oldp, args->newp, c);
1718 if (rc)
1719 goto bad;
1720 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1721 /*
1722 * Switching between MLS and non-MLS policy:
1723 * free any storage used by the MLS fields in the
1724 * context for all existing entries in the sidtab.
1725 */
1726 mls_context_destroy(c);
1727 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1728 /*
1729 * Switching between non-MLS and MLS policy:
1730 * ensure that the MLS fields of the context for all
1731 * existing entries in the sidtab are filled in with a
1732 * suitable default value, likely taken from one of the
1733 * initial SIDs.
1734 */
1735 oc = args->newp->ocontexts[OCON_ISID];
1736 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1737 oc = oc->next;
1738 rc = -EINVAL;
1739 if (!oc) {
1740 printk(KERN_ERR "SELinux: unable to look up"
1741 " the initial SIDs list\n");
1742 goto bad;
1743 }
1744 range = &oc->context[0].range;
1745 rc = mls_range_set(c, range);
1746 if (rc)
1747 goto bad;
1748 }
1749
1750 /* Check the validity of the new context. */
1751 if (!policydb_context_isvalid(args->newp, c)) {
1752 rc = convert_context_handle_invalid_context(&oldc);
1753 if (rc)
1754 goto bad;
1755 }
1756
1757 context_destroy(&oldc);
1758
1759 rc = 0;
1760 out:
1761 return rc;
1762 bad:
1763 /* Map old representation to string and save it. */
1764 rc = context_struct_to_string(&oldc, &s, &len);
1765 if (rc)
1766 return rc;
1767 context_destroy(&oldc);
1768 context_destroy(c);
1769 c->str = s;
1770 c->len = len;
1771 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1772 c->str);
1773 rc = 0;
1774 goto out;
1775 }
1776
1777 static void security_load_policycaps(void)
1778 {
1779 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1780 POLICYDB_CAPABILITY_NETPEER);
1781 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1782 POLICYDB_CAPABILITY_OPENPERM);
1783 }
1784
1785 extern void selinux_complete_init(void);
1786 static int security_preserve_bools(struct policydb *p);
1787
1788 /**
1789 * security_load_policy - Load a security policy configuration.
1790 * @data: binary policy data
1791 * @len: length of data in bytes
1792 *
1793 * Load a new set of security policy configuration data,
1794 * validate it and convert the SID table as necessary.
1795 * This function will flush the access vector cache after
1796 * loading the new policy.
1797 */
1798 int security_load_policy(void *data, size_t len)
1799 {
1800 struct policydb oldpolicydb, newpolicydb;
1801 struct sidtab oldsidtab, newsidtab;
1802 struct selinux_mapping *oldmap, *map = NULL;
1803 struct convert_context_args args;
1804 u32 seqno;
1805 u16 map_size;
1806 int rc = 0;
1807 struct policy_file file = { data, len }, *fp = &file;
1808
1809 if (!ss_initialized) {
1810 avtab_cache_init();
1811 rc = policydb_read(&policydb, fp);
1812 if (rc) {
1813 avtab_cache_destroy();
1814 return rc;
1815 }
1816
1817 policydb.len = len;
1818 rc = selinux_set_mapping(&policydb, secclass_map,
1819 &current_mapping,
1820 &current_mapping_size);
1821 if (rc) {
1822 policydb_destroy(&policydb);
1823 avtab_cache_destroy();
1824 return rc;
1825 }
1826
1827 rc = policydb_load_isids(&policydb, &sidtab);
1828 if (rc) {
1829 policydb_destroy(&policydb);
1830 avtab_cache_destroy();
1831 return rc;
1832 }
1833
1834 security_load_policycaps();
1835 ss_initialized = 1;
1836 seqno = ++latest_granting;
1837 selinux_complete_init();
1838 avc_ss_reset(seqno);
1839 selnl_notify_policyload(seqno);
1840 selinux_status_update_policyload(seqno);
1841 selinux_netlbl_cache_invalidate();
1842 selinux_xfrm_notify_policyload();
1843 return 0;
1844 }
1845
1846 #if 0
1847 sidtab_hash_eval(&sidtab, "sids");
1848 #endif
1849
1850 rc = policydb_read(&newpolicydb, fp);
1851 if (rc)
1852 return rc;
1853
1854 newpolicydb.len = len;
1855 /* If switching between different policy types, log MLS status */
1856 if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1857 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1858 else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1859 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1860
1861 rc = policydb_load_isids(&newpolicydb, &newsidtab);
1862 if (rc) {
1863 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1864 policydb_destroy(&newpolicydb);
1865 return rc;
1866 }
1867
1868 rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1869 if (rc)
1870 goto err;
1871
1872 rc = security_preserve_bools(&newpolicydb);
1873 if (rc) {
1874 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1875 goto err;
1876 }
1877
1878 /* Clone the SID table. */
1879 sidtab_shutdown(&sidtab);
1880
1881 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1882 if (rc)
1883 goto err;
1884
1885 /*
1886 * Convert the internal representations of contexts
1887 * in the new SID table.
1888 */
1889 args.oldp = &policydb;
1890 args.newp = &newpolicydb;
1891 rc = sidtab_map(&newsidtab, convert_context, &args);
1892 if (rc) {
1893 printk(KERN_ERR "SELinux: unable to convert the internal"
1894 " representation of contexts in the new SID"
1895 " table\n");
1896 goto err;
1897 }
1898
1899 /* Save the old policydb and SID table to free later. */
1900 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1901 sidtab_set(&oldsidtab, &sidtab);
1902
1903 /* Install the new policydb and SID table. */
1904 write_lock_irq(&policy_rwlock);
1905 memcpy(&policydb, &newpolicydb, sizeof policydb);
1906 sidtab_set(&sidtab, &newsidtab);
1907 security_load_policycaps();
1908 oldmap = current_mapping;
1909 current_mapping = map;
1910 current_mapping_size = map_size;
1911 seqno = ++latest_granting;
1912 write_unlock_irq(&policy_rwlock);
1913
1914 /* Free the old policydb and SID table. */
1915 policydb_destroy(&oldpolicydb);
1916 sidtab_destroy(&oldsidtab);
1917 kfree(oldmap);
1918
1919 avc_ss_reset(seqno);
1920 selnl_notify_policyload(seqno);
1921 selinux_status_update_policyload(seqno);
1922 selinux_netlbl_cache_invalidate();
1923 selinux_xfrm_notify_policyload();
1924
1925 return 0;
1926
1927 err:
1928 kfree(map);
1929 sidtab_destroy(&newsidtab);
1930 policydb_destroy(&newpolicydb);
1931 return rc;
1932
1933 }
1934
1935 size_t security_policydb_len(void)
1936 {
1937 size_t len;
1938
1939 read_lock(&policy_rwlock);
1940 len = policydb.len;
1941 read_unlock(&policy_rwlock);
1942
1943 return len;
1944 }
1945
1946 /**
1947 * security_port_sid - Obtain the SID for a port.
1948 * @protocol: protocol number
1949 * @port: port number
1950 * @out_sid: security identifier
1951 */
1952 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1953 {
1954 struct ocontext *c;
1955 int rc = 0;
1956
1957 read_lock(&policy_rwlock);
1958
1959 c = policydb.ocontexts[OCON_PORT];
1960 while (c) {
1961 if (c->u.port.protocol == protocol &&
1962 c->u.port.low_port <= port &&
1963 c->u.port.high_port >= port)
1964 break;
1965 c = c->next;
1966 }
1967
1968 if (c) {
1969 if (!c->sid[0]) {
1970 rc = sidtab_context_to_sid(&sidtab,
1971 &c->context[0],
1972 &c->sid[0]);
1973 if (rc)
1974 goto out;
1975 }
1976 *out_sid = c->sid[0];
1977 } else {
1978 *out_sid = SECINITSID_PORT;
1979 }
1980
1981 out:
1982 read_unlock(&policy_rwlock);
1983 return rc;
1984 }
1985
1986 /**
1987 * security_netif_sid - Obtain the SID for a network interface.
1988 * @name: interface name
1989 * @if_sid: interface SID
1990 */
1991 int security_netif_sid(char *name, u32 *if_sid)
1992 {
1993 int rc = 0;
1994 struct ocontext *c;
1995
1996 read_lock(&policy_rwlock);
1997
1998 c = policydb.ocontexts[OCON_NETIF];
1999 while (c) {
2000 if (strcmp(name, c->u.name) == 0)
2001 break;
2002 c = c->next;
2003 }
2004
2005 if (c) {
2006 if (!c->sid[0] || !c->sid[1]) {
2007 rc = sidtab_context_to_sid(&sidtab,
2008 &c->context[0],
2009 &c->sid[0]);
2010 if (rc)
2011 goto out;
2012 rc = sidtab_context_to_sid(&sidtab,
2013 &c->context[1],
2014 &c->sid[1]);
2015 if (rc)
2016 goto out;
2017 }
2018 *if_sid = c->sid[0];
2019 } else
2020 *if_sid = SECINITSID_NETIF;
2021
2022 out:
2023 read_unlock(&policy_rwlock);
2024 return rc;
2025 }
2026
2027 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2028 {
2029 int i, fail = 0;
2030
2031 for (i = 0; i < 4; i++)
2032 if (addr[i] != (input[i] & mask[i])) {
2033 fail = 1;
2034 break;
2035 }
2036
2037 return !fail;
2038 }
2039
2040 /**
2041 * security_node_sid - Obtain the SID for a node (host).
2042 * @domain: communication domain aka address family
2043 * @addrp: address
2044 * @addrlen: address length in bytes
2045 * @out_sid: security identifier
2046 */
2047 int security_node_sid(u16 domain,
2048 void *addrp,
2049 u32 addrlen,
2050 u32 *out_sid)
2051 {
2052 int rc;
2053 struct ocontext *c;
2054
2055 read_lock(&policy_rwlock);
2056
2057 switch (domain) {
2058 case AF_INET: {
2059 u32 addr;
2060
2061 rc = -EINVAL;
2062 if (addrlen != sizeof(u32))
2063 goto out;
2064
2065 addr = *((u32 *)addrp);
2066
2067 c = policydb.ocontexts[OCON_NODE];
2068 while (c) {
2069 if (c->u.node.addr == (addr & c->u.node.mask))
2070 break;
2071 c = c->next;
2072 }
2073 break;
2074 }
2075
2076 case AF_INET6:
2077 rc = -EINVAL;
2078 if (addrlen != sizeof(u64) * 2)
2079 goto out;
2080 c = policydb.ocontexts[OCON_NODE6];
2081 while (c) {
2082 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2083 c->u.node6.mask))
2084 break;
2085 c = c->next;
2086 }
2087 break;
2088
2089 default:
2090 rc = 0;
2091 *out_sid = SECINITSID_NODE;
2092 goto out;
2093 }
2094
2095 if (c) {
2096 if (!c->sid[0]) {
2097 rc = sidtab_context_to_sid(&sidtab,
2098 &c->context[0],
2099 &c->sid[0]);
2100 if (rc)
2101 goto out;
2102 }
2103 *out_sid = c->sid[0];
2104 } else {
2105 *out_sid = SECINITSID_NODE;
2106 }
2107
2108 rc = 0;
2109 out:
2110 read_unlock(&policy_rwlock);
2111 return rc;
2112 }
2113
2114 #define SIDS_NEL 25
2115
2116 /**
2117 * security_get_user_sids - Obtain reachable SIDs for a user.
2118 * @fromsid: starting SID
2119 * @username: username
2120 * @sids: array of reachable SIDs for user
2121 * @nel: number of elements in @sids
2122 *
2123 * Generate the set of SIDs for legal security contexts
2124 * for a given user that can be reached by @fromsid.
2125 * Set *@sids to point to a dynamically allocated
2126 * array containing the set of SIDs. Set *@nel to the
2127 * number of elements in the array.
2128 */
2129
2130 int security_get_user_sids(u32 fromsid,
2131 char *username,
2132 u32 **sids,
2133 u32 *nel)
2134 {
2135 struct context *fromcon, usercon;
2136 u32 *mysids = NULL, *mysids2, sid;
2137 u32 mynel = 0, maxnel = SIDS_NEL;
2138 struct user_datum *user;
2139 struct role_datum *role;
2140 struct ebitmap_node *rnode, *tnode;
2141 int rc = 0, i, j;
2142
2143 *sids = NULL;
2144 *nel = 0;
2145
2146 if (!ss_initialized)
2147 goto out;
2148
2149 read_lock(&policy_rwlock);
2150
2151 context_init(&usercon);
2152
2153 rc = -EINVAL;
2154 fromcon = sidtab_search(&sidtab, fromsid);
2155 if (!fromcon)
2156 goto out_unlock;
2157
2158 rc = -EINVAL;
2159 user = hashtab_search(policydb.p_users.table, username);
2160 if (!user)
2161 goto out_unlock;
2162
2163 usercon.user = user->value;
2164
2165 rc = -ENOMEM;
2166 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2167 if (!mysids)
2168 goto out_unlock;
2169
2170 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2171 role = policydb.role_val_to_struct[i];
2172 usercon.role = i + 1;
2173 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2174 usercon.type = j + 1;
2175
2176 if (mls_setup_user_range(fromcon, user, &usercon))
2177 continue;
2178
2179 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2180 if (rc)
2181 goto out_unlock;
2182 if (mynel < maxnel) {
2183 mysids[mynel++] = sid;
2184 } else {
2185 rc = -ENOMEM;
2186 maxnel += SIDS_NEL;
2187 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2188 if (!mysids2)
2189 goto out_unlock;
2190 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2191 kfree(mysids);
2192 mysids = mysids2;
2193 mysids[mynel++] = sid;
2194 }
2195 }
2196 }
2197 rc = 0;
2198 out_unlock:
2199 read_unlock(&policy_rwlock);
2200 if (rc || !mynel) {
2201 kfree(mysids);
2202 goto out;
2203 }
2204
2205 rc = -ENOMEM;
2206 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2207 if (!mysids2) {
2208 kfree(mysids);
2209 goto out;
2210 }
2211 for (i = 0, j = 0; i < mynel; i++) {
2212 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2213 SECCLASS_PROCESS, /* kernel value */
2214 PROCESS__TRANSITION, AVC_STRICT,
2215 NULL);
2216 if (!rc)
2217 mysids2[j++] = mysids[i];
2218 cond_resched();
2219 }
2220 rc = 0;
2221 kfree(mysids);
2222 *sids = mysids2;
2223 *nel = j;
2224 out:
2225 return rc;
2226 }
2227
2228 /**
2229 * security_genfs_sid - Obtain a SID for a file in a filesystem
2230 * @fstype: filesystem type
2231 * @path: path from root of mount
2232 * @sclass: file security class
2233 * @sid: SID for path
2234 *
2235 * Obtain a SID to use for a file in a filesystem that
2236 * cannot support xattr or use a fixed labeling behavior like
2237 * transition SIDs or task SIDs.
2238 */
2239 int security_genfs_sid(const char *fstype,
2240 char *path,
2241 u16 orig_sclass,
2242 u32 *sid)
2243 {
2244 int len;
2245 u16 sclass;
2246 struct genfs *genfs;
2247 struct ocontext *c;
2248 int rc, cmp = 0;
2249
2250 while (path[0] == '/' && path[1] == '/')
2251 path++;
2252
2253 read_lock(&policy_rwlock);
2254
2255 sclass = unmap_class(orig_sclass);
2256 *sid = SECINITSID_UNLABELED;
2257
2258 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2259 cmp = strcmp(fstype, genfs->fstype);
2260 if (cmp <= 0)
2261 break;
2262 }
2263
2264 rc = -ENOENT;
2265 if (!genfs || cmp)
2266 goto out;
2267
2268 for (c = genfs->head; c; c = c->next) {
2269 len = strlen(c->u.name);
2270 if ((!c->v.sclass || sclass == c->v.sclass) &&
2271 (strncmp(c->u.name, path, len) == 0))
2272 break;
2273 }
2274
2275 rc = -ENOENT;
2276 if (!c)
2277 goto out;
2278
2279 if (!c->sid[0]) {
2280 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2281 if (rc)
2282 goto out;
2283 }
2284
2285 *sid = c->sid[0];
2286 rc = 0;
2287 out:
2288 read_unlock(&policy_rwlock);
2289 return rc;
2290 }
2291
2292 /**
2293 * security_fs_use - Determine how to handle labeling for a filesystem.
2294 * @fstype: filesystem type
2295 * @behavior: labeling behavior
2296 * @sid: SID for filesystem (superblock)
2297 */
2298 int security_fs_use(
2299 const char *fstype,
2300 unsigned int *behavior,
2301 u32 *sid)
2302 {
2303 int rc = 0;
2304 struct ocontext *c;
2305
2306 read_lock(&policy_rwlock);
2307
2308 c = policydb.ocontexts[OCON_FSUSE];
2309 while (c) {
2310 if (strcmp(fstype, c->u.name) == 0)
2311 break;
2312 c = c->next;
2313 }
2314
2315 if (c) {
2316 *behavior = c->v.behavior;
2317 if (!c->sid[0]) {
2318 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2319 &c->sid[0]);
2320 if (rc)
2321 goto out;
2322 }
2323 *sid = c->sid[0];
2324 } else {
2325 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2326 if (rc) {
2327 *behavior = SECURITY_FS_USE_NONE;
2328 rc = 0;
2329 } else {
2330 *behavior = SECURITY_FS_USE_GENFS;
2331 }
2332 }
2333
2334 out:
2335 read_unlock(&policy_rwlock);
2336 return rc;
2337 }
2338
2339 int security_get_bools(int *len, char ***names, int **values)
2340 {
2341 int i, rc;
2342
2343 read_lock(&policy_rwlock);
2344 *names = NULL;
2345 *values = NULL;
2346
2347 rc = 0;
2348 *len = policydb.p_bools.nprim;
2349 if (!*len)
2350 goto out;
2351
2352 rc = -ENOMEM;
2353 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2354 if (!*names)
2355 goto err;
2356
2357 rc = -ENOMEM;
2358 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2359 if (!*values)
2360 goto err;
2361
2362 for (i = 0; i < *len; i++) {
2363 size_t name_len;
2364
2365 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2366 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2367
2368 rc = -ENOMEM;
2369 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2370 if (!(*names)[i])
2371 goto err;
2372
2373 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2374 (*names)[i][name_len - 1] = 0;
2375 }
2376 rc = 0;
2377 out:
2378 read_unlock(&policy_rwlock);
2379 return rc;
2380 err:
2381 if (*names) {
2382 for (i = 0; i < *len; i++)
2383 kfree((*names)[i]);
2384 }
2385 kfree(*values);
2386 goto out;
2387 }
2388
2389
2390 int security_set_bools(int len, int *values)
2391 {
2392 int i, rc;
2393 int lenp, seqno = 0;
2394 struct cond_node *cur;
2395
2396 write_lock_irq(&policy_rwlock);
2397
2398 rc = -EFAULT;
2399 lenp = policydb.p_bools.nprim;
2400 if (len != lenp)
2401 goto out;
2402
2403 for (i = 0; i < len; i++) {
2404 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2405 audit_log(current->audit_context, GFP_ATOMIC,
2406 AUDIT_MAC_CONFIG_CHANGE,
2407 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2408 sym_name(&policydb, SYM_BOOLS, i),
2409 !!values[i],
2410 policydb.bool_val_to_struct[i]->state,
2411 audit_get_loginuid(current),
2412 audit_get_sessionid(current));
2413 }
2414 if (values[i])
2415 policydb.bool_val_to_struct[i]->state = 1;
2416 else
2417 policydb.bool_val_to_struct[i]->state = 0;
2418 }
2419
2420 for (cur = policydb.cond_list; cur; cur = cur->next) {
2421 rc = evaluate_cond_node(&policydb, cur);
2422 if (rc)
2423 goto out;
2424 }
2425
2426 seqno = ++latest_granting;
2427 rc = 0;
2428 out:
2429 write_unlock_irq(&policy_rwlock);
2430 if (!rc) {
2431 avc_ss_reset(seqno);
2432 selnl_notify_policyload(seqno);
2433 selinux_status_update_policyload(seqno);
2434 selinux_xfrm_notify_policyload();
2435 }
2436 return rc;
2437 }
2438
2439 int security_get_bool_value(int bool)
2440 {
2441 int rc;
2442 int len;
2443
2444 read_lock(&policy_rwlock);
2445
2446 rc = -EFAULT;
2447 len = policydb.p_bools.nprim;
2448 if (bool >= len)
2449 goto out;
2450
2451 rc = policydb.bool_val_to_struct[bool]->state;
2452 out:
2453 read_unlock(&policy_rwlock);
2454 return rc;
2455 }
2456
2457 static int security_preserve_bools(struct policydb *p)
2458 {
2459 int rc, nbools = 0, *bvalues = NULL, i;
2460 char **bnames = NULL;
2461 struct cond_bool_datum *booldatum;
2462 struct cond_node *cur;
2463
2464 rc = security_get_bools(&nbools, &bnames, &bvalues);
2465 if (rc)
2466 goto out;
2467 for (i = 0; i < nbools; i++) {
2468 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2469 if (booldatum)
2470 booldatum->state = bvalues[i];
2471 }
2472 for (cur = p->cond_list; cur; cur = cur->next) {
2473 rc = evaluate_cond_node(p, cur);
2474 if (rc)
2475 goto out;
2476 }
2477
2478 out:
2479 if (bnames) {
2480 for (i = 0; i < nbools; i++)
2481 kfree(bnames[i]);
2482 }
2483 kfree(bnames);
2484 kfree(bvalues);
2485 return rc;
2486 }
2487
2488 /*
2489 * security_sid_mls_copy() - computes a new sid based on the given
2490 * sid and the mls portion of mls_sid.
2491 */
2492 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2493 {
2494 struct context *context1;
2495 struct context *context2;
2496 struct context newcon;
2497 char *s;
2498 u32 len;
2499 int rc;
2500
2501 rc = 0;
2502 if (!ss_initialized || !policydb.mls_enabled) {
2503 *new_sid = sid;
2504 goto out;
2505 }
2506
2507 context_init(&newcon);
2508
2509 read_lock(&policy_rwlock);
2510
2511 rc = -EINVAL;
2512 context1 = sidtab_search(&sidtab, sid);
2513 if (!context1) {
2514 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2515 __func__, sid);
2516 goto out_unlock;
2517 }
2518
2519 rc = -EINVAL;
2520 context2 = sidtab_search(&sidtab, mls_sid);
2521 if (!context2) {
2522 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2523 __func__, mls_sid);
2524 goto out_unlock;
2525 }
2526
2527 newcon.user = context1->user;
2528 newcon.role = context1->role;
2529 newcon.type = context1->type;
2530 rc = mls_context_cpy(&newcon, context2);
2531 if (rc)
2532 goto out_unlock;
2533
2534 /* Check the validity of the new context. */
2535 if (!policydb_context_isvalid(&policydb, &newcon)) {
2536 rc = convert_context_handle_invalid_context(&newcon);
2537 if (rc) {
2538 if (!context_struct_to_string(&newcon, &s, &len)) {
2539 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2540 "security_sid_mls_copy: invalid context %s", s);
2541 kfree(s);
2542 }
2543 goto out_unlock;
2544 }
2545 }
2546
2547 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2548 out_unlock:
2549 read_unlock(&policy_rwlock);
2550 context_destroy(&newcon);
2551 out:
2552 return rc;
2553 }
2554
2555 /**
2556 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2557 * @nlbl_sid: NetLabel SID
2558 * @nlbl_type: NetLabel labeling protocol type
2559 * @xfrm_sid: XFRM SID
2560 *
2561 * Description:
2562 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2563 * resolved into a single SID it is returned via @peer_sid and the function
2564 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2565 * returns a negative value. A table summarizing the behavior is below:
2566 *
2567 * | function return | @sid
2568 * ------------------------------+-----------------+-----------------
2569 * no peer labels | 0 | SECSID_NULL
2570 * single peer label | 0 | <peer_label>
2571 * multiple, consistent labels | 0 | <peer_label>
2572 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2573 *
2574 */
2575 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2576 u32 xfrm_sid,
2577 u32 *peer_sid)
2578 {
2579 int rc;
2580 struct context *nlbl_ctx;
2581 struct context *xfrm_ctx;
2582
2583 *peer_sid = SECSID_NULL;
2584
2585 /* handle the common (which also happens to be the set of easy) cases
2586 * right away, these two if statements catch everything involving a
2587 * single or absent peer SID/label */
2588 if (xfrm_sid == SECSID_NULL) {
2589 *peer_sid = nlbl_sid;
2590 return 0;
2591 }
2592 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2593 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2594 * is present */
2595 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2596 *peer_sid = xfrm_sid;
2597 return 0;
2598 }
2599
2600 /* we don't need to check ss_initialized here since the only way both
2601 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2602 * security server was initialized and ss_initialized was true */
2603 if (!policydb.mls_enabled)
2604 return 0;
2605
2606 read_lock(&policy_rwlock);
2607
2608 rc = -EINVAL;
2609 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2610 if (!nlbl_ctx) {
2611 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2612 __func__, nlbl_sid);
2613 goto out;
2614 }
2615 rc = -EINVAL;
2616 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2617 if (!xfrm_ctx) {
2618 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2619 __func__, xfrm_sid);
2620 goto out;
2621 }
2622 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2623 if (rc)
2624 goto out;
2625
2626 /* at present NetLabel SIDs/labels really only carry MLS
2627 * information so if the MLS portion of the NetLabel SID
2628 * matches the MLS portion of the labeled XFRM SID/label
2629 * then pass along the XFRM SID as it is the most
2630 * expressive */
2631 *peer_sid = xfrm_sid;
2632 out:
2633 read_unlock(&policy_rwlock);
2634 return rc;
2635 }
2636
2637 static int get_classes_callback(void *k, void *d, void *args)
2638 {
2639 struct class_datum *datum = d;
2640 char *name = k, **classes = args;
2641 int value = datum->value - 1;
2642
2643 classes[value] = kstrdup(name, GFP_ATOMIC);
2644 if (!classes[value])
2645 return -ENOMEM;
2646
2647 return 0;
2648 }
2649
2650 int security_get_classes(char ***classes, int *nclasses)
2651 {
2652 int rc;
2653
2654 read_lock(&policy_rwlock);
2655
2656 rc = -ENOMEM;
2657 *nclasses = policydb.p_classes.nprim;
2658 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2659 if (!*classes)
2660 goto out;
2661
2662 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2663 *classes);
2664 if (rc) {
2665 int i;
2666 for (i = 0; i < *nclasses; i++)
2667 kfree((*classes)[i]);
2668 kfree(*classes);
2669 }
2670
2671 out:
2672 read_unlock(&policy_rwlock);
2673 return rc;
2674 }
2675
2676 static int get_permissions_callback(void *k, void *d, void *args)
2677 {
2678 struct perm_datum *datum = d;
2679 char *name = k, **perms = args;
2680 int value = datum->value - 1;
2681
2682 perms[value] = kstrdup(name, GFP_ATOMIC);
2683 if (!perms[value])
2684 return -ENOMEM;
2685
2686 return 0;
2687 }
2688
2689 int security_get_permissions(char *class, char ***perms, int *nperms)
2690 {
2691 int rc, i;
2692 struct class_datum *match;
2693
2694 read_lock(&policy_rwlock);
2695
2696 rc = -EINVAL;
2697 match = hashtab_search(policydb.p_classes.table, class);
2698 if (!match) {
2699 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2700 __func__, class);
2701 goto out;
2702 }
2703
2704 rc = -ENOMEM;
2705 *nperms = match->permissions.nprim;
2706 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2707 if (!*perms)
2708 goto out;
2709
2710 if (match->comdatum) {
2711 rc = hashtab_map(match->comdatum->permissions.table,
2712 get_permissions_callback, *perms);
2713 if (rc)
2714 goto err;
2715 }
2716
2717 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2718 *perms);
2719 if (rc)
2720 goto err;
2721
2722 out:
2723 read_unlock(&policy_rwlock);
2724 return rc;
2725
2726 err:
2727 read_unlock(&policy_rwlock);
2728 for (i = 0; i < *nperms; i++)
2729 kfree((*perms)[i]);
2730 kfree(*perms);
2731 return rc;
2732 }
2733
2734 int security_get_reject_unknown(void)
2735 {
2736 return policydb.reject_unknown;
2737 }
2738
2739 int security_get_allow_unknown(void)
2740 {
2741 return policydb.allow_unknown;
2742 }
2743
2744 /**
2745 * security_policycap_supported - Check for a specific policy capability
2746 * @req_cap: capability
2747 *
2748 * Description:
2749 * This function queries the currently loaded policy to see if it supports the
2750 * capability specified by @req_cap. Returns true (1) if the capability is
2751 * supported, false (0) if it isn't supported.
2752 *
2753 */
2754 int security_policycap_supported(unsigned int req_cap)
2755 {
2756 int rc;
2757
2758 read_lock(&policy_rwlock);
2759 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2760 read_unlock(&policy_rwlock);
2761
2762 return rc;
2763 }
2764
2765 struct selinux_audit_rule {
2766 u32 au_seqno;
2767 struct context au_ctxt;
2768 };
2769
2770 void selinux_audit_rule_free(void *vrule)
2771 {
2772 struct selinux_audit_rule *rule = vrule;
2773
2774 if (rule) {
2775 context_destroy(&rule->au_ctxt);
2776 kfree(rule);
2777 }
2778 }
2779
2780 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2781 {
2782 struct selinux_audit_rule *tmprule;
2783 struct role_datum *roledatum;
2784 struct type_datum *typedatum;
2785 struct user_datum *userdatum;
2786 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2787 int rc = 0;
2788
2789 *rule = NULL;
2790
2791 if (!ss_initialized)
2792 return -EOPNOTSUPP;
2793
2794 switch (field) {
2795 case AUDIT_SUBJ_USER:
2796 case AUDIT_SUBJ_ROLE:
2797 case AUDIT_SUBJ_TYPE:
2798 case AUDIT_OBJ_USER:
2799 case AUDIT_OBJ_ROLE:
2800 case AUDIT_OBJ_TYPE:
2801 /* only 'equals' and 'not equals' fit user, role, and type */
2802 if (op != Audit_equal && op != Audit_not_equal)
2803 return -EINVAL;
2804 break;
2805 case AUDIT_SUBJ_SEN:
2806 case AUDIT_SUBJ_CLR:
2807 case AUDIT_OBJ_LEV_LOW:
2808 case AUDIT_OBJ_LEV_HIGH:
2809 /* we do not allow a range, indicated by the presense of '-' */
2810 if (strchr(rulestr, '-'))
2811 return -EINVAL;
2812 break;
2813 default:
2814 /* only the above fields are valid */
2815 return -EINVAL;
2816 }
2817
2818 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2819 if (!tmprule)
2820 return -ENOMEM;
2821
2822 context_init(&tmprule->au_ctxt);
2823
2824 read_lock(&policy_rwlock);
2825
2826 tmprule->au_seqno = latest_granting;
2827
2828 switch (field) {
2829 case AUDIT_SUBJ_USER:
2830 case AUDIT_OBJ_USER:
2831 rc = -EINVAL;
2832 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2833 if (!userdatum)
2834 goto out;
2835 tmprule->au_ctxt.user = userdatum->value;
2836 break;
2837 case AUDIT_SUBJ_ROLE:
2838 case AUDIT_OBJ_ROLE:
2839 rc = -EINVAL;
2840 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2841 if (!roledatum)
2842 goto out;
2843 tmprule->au_ctxt.role = roledatum->value;
2844 break;
2845 case AUDIT_SUBJ_TYPE:
2846 case AUDIT_OBJ_TYPE:
2847 rc = -EINVAL;
2848 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2849 if (!typedatum)
2850 goto out;
2851 tmprule->au_ctxt.type = typedatum->value;
2852 break;
2853 case AUDIT_SUBJ_SEN:
2854 case AUDIT_SUBJ_CLR:
2855 case AUDIT_OBJ_LEV_LOW:
2856 case AUDIT_OBJ_LEV_HIGH:
2857 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2858 if (rc)
2859 goto out;
2860 break;
2861 }
2862 rc = 0;
2863 out:
2864 read_unlock(&policy_rwlock);
2865
2866 if (rc) {
2867 selinux_audit_rule_free(tmprule);
2868 tmprule = NULL;
2869 }
2870
2871 *rule = tmprule;
2872
2873 return rc;
2874 }
2875
2876 /* Check to see if the rule contains any selinux fields */
2877 int selinux_audit_rule_known(struct audit_krule *rule)
2878 {
2879 int i;
2880
2881 for (i = 0; i < rule->field_count; i++) {
2882 struct audit_field *f = &rule->fields[i];
2883 switch (f->type) {
2884 case AUDIT_SUBJ_USER:
2885 case AUDIT_SUBJ_ROLE:
2886 case AUDIT_SUBJ_TYPE:
2887 case AUDIT_SUBJ_SEN:
2888 case AUDIT_SUBJ_CLR:
2889 case AUDIT_OBJ_USER:
2890 case AUDIT_OBJ_ROLE:
2891 case AUDIT_OBJ_TYPE:
2892 case AUDIT_OBJ_LEV_LOW:
2893 case AUDIT_OBJ_LEV_HIGH:
2894 return 1;
2895 }
2896 }
2897
2898 return 0;
2899 }
2900
2901 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2902 struct audit_context *actx)
2903 {
2904 struct context *ctxt;
2905 struct mls_level *level;
2906 struct selinux_audit_rule *rule = vrule;
2907 int match = 0;
2908
2909 if (!rule) {
2910 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2911 "selinux_audit_rule_match: missing rule\n");
2912 return -ENOENT;
2913 }
2914
2915 read_lock(&policy_rwlock);
2916
2917 if (rule->au_seqno < latest_granting) {
2918 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2919 "selinux_audit_rule_match: stale rule\n");
2920 match = -ESTALE;
2921 goto out;
2922 }
2923
2924 ctxt = sidtab_search(&sidtab, sid);
2925 if (!ctxt) {
2926 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2927 "selinux_audit_rule_match: unrecognized SID %d\n",
2928 sid);
2929 match = -ENOENT;
2930 goto out;
2931 }
2932
2933 /* a field/op pair that is not caught here will simply fall through
2934 without a match */
2935 switch (field) {
2936 case AUDIT_SUBJ_USER:
2937 case AUDIT_OBJ_USER:
2938 switch (op) {
2939 case Audit_equal:
2940 match = (ctxt->user == rule->au_ctxt.user);
2941 break;
2942 case Audit_not_equal:
2943 match = (ctxt->user != rule->au_ctxt.user);
2944 break;
2945 }
2946 break;
2947 case AUDIT_SUBJ_ROLE:
2948 case AUDIT_OBJ_ROLE:
2949 switch (op) {
2950 case Audit_equal:
2951 match = (ctxt->role == rule->au_ctxt.role);
2952 break;
2953 case Audit_not_equal:
2954 match = (ctxt->role != rule->au_ctxt.role);
2955 break;
2956 }
2957 break;
2958 case AUDIT_SUBJ_TYPE:
2959 case AUDIT_OBJ_TYPE:
2960 switch (op) {
2961 case Audit_equal:
2962 match = (ctxt->type == rule->au_ctxt.type);
2963 break;
2964 case Audit_not_equal:
2965 match = (ctxt->type != rule->au_ctxt.type);
2966 break;
2967 }
2968 break;
2969 case AUDIT_SUBJ_SEN:
2970 case AUDIT_SUBJ_CLR:
2971 case AUDIT_OBJ_LEV_LOW:
2972 case AUDIT_OBJ_LEV_HIGH:
2973 level = ((field == AUDIT_SUBJ_SEN ||
2974 field == AUDIT_OBJ_LEV_LOW) ?
2975 &ctxt->range.level[0] : &ctxt->range.level[1]);
2976 switch (op) {
2977 case Audit_equal:
2978 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2979 level);
2980 break;
2981 case Audit_not_equal:
2982 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2983 level);
2984 break;
2985 case Audit_lt:
2986 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2987 level) &&
2988 !mls_level_eq(&rule->au_ctxt.range.level[0],
2989 level));
2990 break;
2991 case Audit_le:
2992 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2993 level);
2994 break;
2995 case Audit_gt:
2996 match = (mls_level_dom(level,
2997 &rule->au_ctxt.range.level[0]) &&
2998 !mls_level_eq(level,
2999 &rule->au_ctxt.range.level[0]));
3000 break;
3001 case Audit_ge:
3002 match = mls_level_dom(level,
3003 &rule->au_ctxt.range.level[0]);
3004 break;
3005 }
3006 }
3007
3008 out:
3009 read_unlock(&policy_rwlock);
3010 return match;
3011 }
3012
3013 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3014
3015 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3016 u16 class, u32 perms, u32 *retained)
3017 {
3018 int err = 0;
3019
3020 if (event == AVC_CALLBACK_RESET && aurule_callback)
3021 err = aurule_callback();
3022 return err;
3023 }
3024
3025 static int __init aurule_init(void)
3026 {
3027 int err;
3028
3029 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3030 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3031 if (err)
3032 panic("avc_add_callback() failed, error %d\n", err);
3033
3034 return err;
3035 }
3036 __initcall(aurule_init);
3037
3038 #ifdef CONFIG_NETLABEL
3039 /**
3040 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3041 * @secattr: the NetLabel packet security attributes
3042 * @sid: the SELinux SID
3043 *
3044 * Description:
3045 * Attempt to cache the context in @ctx, which was derived from the packet in
3046 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3047 * already been initialized.
3048 *
3049 */
3050 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3051 u32 sid)
3052 {
3053 u32 *sid_cache;
3054
3055 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3056 if (sid_cache == NULL)
3057 return;
3058 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3059 if (secattr->cache == NULL) {
3060 kfree(sid_cache);
3061 return;
3062 }
3063
3064 *sid_cache = sid;
3065 secattr->cache->free = kfree;
3066 secattr->cache->data = sid_cache;
3067 secattr->flags |= NETLBL_SECATTR_CACHE;
3068 }
3069
3070 /**
3071 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3072 * @secattr: the NetLabel packet security attributes
3073 * @sid: the SELinux SID
3074 *
3075 * Description:
3076 * Convert the given NetLabel security attributes in @secattr into a
3077 * SELinux SID. If the @secattr field does not contain a full SELinux
3078 * SID/context then use SECINITSID_NETMSG as the foundation. If possibile the
3079 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3080 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3081 * conversion for future lookups. Returns zero on success, negative values on
3082 * failure.
3083 *
3084 */
3085 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3086 u32 *sid)
3087 {
3088 int rc;
3089 struct context *ctx;
3090 struct context ctx_new;
3091
3092 if (!ss_initialized) {
3093 *sid = SECSID_NULL;
3094 return 0;
3095 }
3096
3097 read_lock(&policy_rwlock);
3098
3099 if (secattr->flags & NETLBL_SECATTR_CACHE)
3100 *sid = *(u32 *)secattr->cache->data;
3101 else if (secattr->flags & NETLBL_SECATTR_SECID)
3102 *sid = secattr->attr.secid;
3103 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3104 rc = -EIDRM;
3105 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3106 if (ctx == NULL)
3107 goto out;
3108
3109 context_init(&ctx_new);
3110 ctx_new.user = ctx->user;
3111 ctx_new.role = ctx->role;
3112 ctx_new.type = ctx->type;
3113 mls_import_netlbl_lvl(&ctx_new, secattr);
3114 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3115 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3116 secattr->attr.mls.cat);
3117 if (rc)
3118 goto out;
3119 memcpy(&ctx_new.range.level[1].cat,
3120 &ctx_new.range.level[0].cat,
3121 sizeof(ctx_new.range.level[0].cat));
3122 }
3123 rc = -EIDRM;
3124 if (!mls_context_isvalid(&policydb, &ctx_new))
3125 goto out_free;
3126
3127 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3128 if (rc)
3129 goto out_free;
3130
3131 security_netlbl_cache_add(secattr, *sid);
3132
3133 ebitmap_destroy(&ctx_new.range.level[0].cat);
3134 } else
3135 *sid = SECSID_NULL;
3136
3137 read_unlock(&policy_rwlock);
3138 return 0;
3139 out_free:
3140 ebitmap_destroy(&ctx_new.range.level[0].cat);
3141 out:
3142 read_unlock(&policy_rwlock);
3143 return rc;
3144 }
3145
3146 /**
3147 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3148 * @sid: the SELinux SID
3149 * @secattr: the NetLabel packet security attributes
3150 *
3151 * Description:
3152 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3153 * Returns zero on success, negative values on failure.
3154 *
3155 */
3156 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3157 {
3158 int rc;
3159 struct context *ctx;
3160
3161 if (!ss_initialized)
3162 return 0;
3163
3164 read_lock(&policy_rwlock);
3165
3166 rc = -ENOENT;
3167 ctx = sidtab_search(&sidtab, sid);
3168 if (ctx == NULL)
3169 goto out;
3170
3171 rc = -ENOMEM;
3172 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3173 GFP_ATOMIC);
3174 if (secattr->domain == NULL)
3175 goto out;
3176
3177 secattr->attr.secid = sid;
3178 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3179 mls_export_netlbl_lvl(ctx, secattr);
3180 rc = mls_export_netlbl_cat(ctx, secattr);
3181 out:
3182 read_unlock(&policy_rwlock);
3183 return rc;
3184 }
3185 #endif /* CONFIG_NETLABEL */
3186
3187 /**
3188 * security_read_policy - read the policy.
3189 * @data: binary policy data
3190 * @len: length of data in bytes
3191 *
3192 */
3193 int security_read_policy(void **data, ssize_t *len)
3194 {
3195 int rc;
3196 struct policy_file fp;
3197
3198 if (!ss_initialized)
3199 return -EINVAL;
3200
3201 *len = security_policydb_len();
3202
3203 *data = vmalloc_user(*len);
3204 if (!*data)
3205 return -ENOMEM;
3206
3207 fp.data = *data;
3208 fp.len = *len;
3209
3210 read_lock(&policy_rwlock);
3211 rc = policydb_write(&policydb, &fp);
3212 read_unlock(&policy_rwlock);
3213
3214 if (rc)
3215 return rc;
3216
3217 *len = (unsigned long)fp.data - (unsigned long)*data;
3218 return 0;
3219
3220 }
CRIS linux kernel tree