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cgroup: fix an off-by-one bug which may trigger BUG_ON()
[linux/fpc-iii.git] / security / selinux / ss / services.c
blob185f849a26f6049a71fccf197cf5233ece3e3a99
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@paul-moore.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 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75
76 static DEFINE_RWLOCK(policy_rwlock);
77
78 static struct sidtab sidtab;
79 struct policydb policydb;
80 int ss_initialized;
81
82 /*
83 * The largest sequence number that has been used when
84 * providing an access decision to the access vector cache.
85 * The sequence number only changes when a policy change
86 * occurs.
87 */
88 static u32 latest_granting;
89
90 /* Forward declaration. */
91 static int context_struct_to_string(struct context *context, char **scontext,
92 u32 *scontext_len);
93
94 static void context_struct_compute_av(struct context *scontext,
95 struct context *tcontext,
96 u16 tclass,
97 struct av_decision *avd);
98
99 struct selinux_mapping {
100 u16 value; /* policy value */
101 unsigned num_perms;
102 u32 perms[sizeof(u32) * 8];
103 };
104
105 static struct selinux_mapping *current_mapping;
106 static u16 current_mapping_size;
107
108 static int selinux_set_mapping(struct policydb *pol,
109 struct security_class_mapping *map,
110 struct selinux_mapping **out_map_p,
111 u16 *out_map_size)
112 {
113 struct selinux_mapping *out_map = NULL;
114 size_t size = sizeof(struct selinux_mapping);
115 u16 i, j;
116 unsigned k;
117 bool print_unknown_handle = false;
118
119 /* Find number of classes in the input mapping */
120 if (!map)
121 return -EINVAL;
122 i = 0;
123 while (map[i].name)
124 i++;
125
126 /* Allocate space for the class records, plus one for class zero */
127 out_map = kcalloc(++i, size, GFP_ATOMIC);
128 if (!out_map)
129 return -ENOMEM;
130
131 /* Store the raw class and permission values */
132 j = 0;
133 while (map[j].name) {
134 struct security_class_mapping *p_in = map + (j++);
135 struct selinux_mapping *p_out = out_map + j;
136
137 /* An empty class string skips ahead */
138 if (!strcmp(p_in->name, "")) {
139 p_out->num_perms = 0;
140 continue;
141 }
142
143 p_out->value = string_to_security_class(pol, p_in->name);
144 if (!p_out->value) {
145 printk(KERN_INFO
146 "SELinux: Class %s not defined in policy.\n",
147 p_in->name);
148 if (pol->reject_unknown)
149 goto err;
150 p_out->num_perms = 0;
151 print_unknown_handle = true;
152 continue;
153 }
154
155 k = 0;
156 while (p_in->perms && p_in->perms[k]) {
157 /* An empty permission string skips ahead */
158 if (!*p_in->perms[k]) {
159 k++;
160 continue;
161 }
162 p_out->perms[k] = string_to_av_perm(pol, p_out->value,
163 p_in->perms[k]);
164 if (!p_out->perms[k]) {
165 printk(KERN_INFO
166 "SELinux: Permission %s in class %s not defined in policy.\n",
167 p_in->perms[k], p_in->name);
168 if (pol->reject_unknown)
169 goto err;
170 print_unknown_handle = true;
171 }
172
173 k++;
174 }
175 p_out->num_perms = k;
176 }
177
178 if (print_unknown_handle)
179 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
180 pol->allow_unknown ? "allowed" : "denied");
181
182 *out_map_p = out_map;
183 *out_map_size = i;
184 return 0;
185 err:
186 kfree(out_map);
187 return -EINVAL;
188 }
189
190 /*
191 * Get real, policy values from mapped values
192 */
193
194 static u16 unmap_class(u16 tclass)
195 {
196 if (tclass < current_mapping_size)
197 return current_mapping[tclass].value;
198
199 return tclass;
200 }
201
202 /*
203 * Get kernel value for class from its policy value
204 */
205 static u16 map_class(u16 pol_value)
206 {
207 u16 i;
208
209 for (i = 1; i < current_mapping_size; i++) {
210 if (current_mapping[i].value == pol_value)
211 return i;
212 }
213
214 return SECCLASS_NULL;
215 }
216
217 static void map_decision(u16 tclass, struct av_decision *avd,
218 int allow_unknown)
219 {
220 if (tclass < current_mapping_size) {
221 unsigned i, n = current_mapping[tclass].num_perms;
222 u32 result;
223
224 for (i = 0, result = 0; i < n; i++) {
225 if (avd->allowed & current_mapping[tclass].perms[i])
226 result |= 1<<i;
227 if (allow_unknown && !current_mapping[tclass].perms[i])
228 result |= 1<<i;
229 }
230 avd->allowed = result;
231
232 for (i = 0, result = 0; i < n; i++)
233 if (avd->auditallow & current_mapping[tclass].perms[i])
234 result |= 1<<i;
235 avd->auditallow = result;
236
237 for (i = 0, result = 0; i < n; i++) {
238 if (avd->auditdeny & current_mapping[tclass].perms[i])
239 result |= 1<<i;
240 if (!allow_unknown && !current_mapping[tclass].perms[i])
241 result |= 1<<i;
242 }
243 /*
244 * In case the kernel has a bug and requests a permission
245 * between num_perms and the maximum permission number, we
246 * should audit that denial
247 */
248 for (; i < (sizeof(u32)*8); i++)
249 result |= 1<<i;
250 avd->auditdeny = result;
251 }
252 }
253
254 int security_mls_enabled(void)
255 {
256 return policydb.mls_enabled;
257 }
258
259 /*
260 * Return the boolean value of a constraint expression
261 * when it is applied to the specified source and target
262 * security contexts.
263 *
264 * xcontext is a special beast... It is used by the validatetrans rules
265 * only. For these rules, scontext is the context before the transition,
266 * tcontext is the context after the transition, and xcontext is the context
267 * of the process performing the transition. All other callers of
268 * constraint_expr_eval should pass in NULL for xcontext.
269 */
270 static int constraint_expr_eval(struct context *scontext,
271 struct context *tcontext,
272 struct context *xcontext,
273 struct constraint_expr *cexpr)
274 {
275 u32 val1, val2;
276 struct context *c;
277 struct role_datum *r1, *r2;
278 struct mls_level *l1, *l2;
279 struct constraint_expr *e;
280 int s[CEXPR_MAXDEPTH];
281 int sp = -1;
282
283 for (e = cexpr; e; e = e->next) {
284 switch (e->expr_type) {
285 case CEXPR_NOT:
286 BUG_ON(sp < 0);
287 s[sp] = !s[sp];
288 break;
289 case CEXPR_AND:
290 BUG_ON(sp < 1);
291 sp--;
292 s[sp] &= s[sp + 1];
293 break;
294 case CEXPR_OR:
295 BUG_ON(sp < 1);
296 sp--;
297 s[sp] |= s[sp + 1];
298 break;
299 case CEXPR_ATTR:
300 if (sp == (CEXPR_MAXDEPTH - 1))
301 return 0;
302 switch (e->attr) {
303 case CEXPR_USER:
304 val1 = scontext->user;
305 val2 = tcontext->user;
306 break;
307 case CEXPR_TYPE:
308 val1 = scontext->type;
309 val2 = tcontext->type;
310 break;
311 case CEXPR_ROLE:
312 val1 = scontext->role;
313 val2 = tcontext->role;
314 r1 = policydb.role_val_to_struct[val1 - 1];
315 r2 = policydb.role_val_to_struct[val2 - 1];
316 switch (e->op) {
317 case CEXPR_DOM:
318 s[++sp] = ebitmap_get_bit(&r1->dominates,
319 val2 - 1);
320 continue;
321 case CEXPR_DOMBY:
322 s[++sp] = ebitmap_get_bit(&r2->dominates,
323 val1 - 1);
324 continue;
325 case CEXPR_INCOMP:
326 s[++sp] = (!ebitmap_get_bit(&r1->dominates,
327 val2 - 1) &&
328 !ebitmap_get_bit(&r2->dominates,
329 val1 - 1));
330 continue;
331 default:
332 break;
333 }
334 break;
335 case CEXPR_L1L2:
336 l1 = &(scontext->range.level[0]);
337 l2 = &(tcontext->range.level[0]);
338 goto mls_ops;
339 case CEXPR_L1H2:
340 l1 = &(scontext->range.level[0]);
341 l2 = &(tcontext->range.level[1]);
342 goto mls_ops;
343 case CEXPR_H1L2:
344 l1 = &(scontext->range.level[1]);
345 l2 = &(tcontext->range.level[0]);
346 goto mls_ops;
347 case CEXPR_H1H2:
348 l1 = &(scontext->range.level[1]);
349 l2 = &(tcontext->range.level[1]);
350 goto mls_ops;
351 case CEXPR_L1H1:
352 l1 = &(scontext->range.level[0]);
353 l2 = &(scontext->range.level[1]);
354 goto mls_ops;
355 case CEXPR_L2H2:
356 l1 = &(tcontext->range.level[0]);
357 l2 = &(tcontext->range.level[1]);
358 goto mls_ops;
359 mls_ops:
360 switch (e->op) {
361 case CEXPR_EQ:
362 s[++sp] = mls_level_eq(l1, l2);
363 continue;
364 case CEXPR_NEQ:
365 s[++sp] = !mls_level_eq(l1, l2);
366 continue;
367 case CEXPR_DOM:
368 s[++sp] = mls_level_dom(l1, l2);
369 continue;
370 case CEXPR_DOMBY:
371 s[++sp] = mls_level_dom(l2, l1);
372 continue;
373 case CEXPR_INCOMP:
374 s[++sp] = mls_level_incomp(l2, l1);
375 continue;
376 default:
377 BUG();
378 return 0;
379 }
380 break;
381 default:
382 BUG();
383 return 0;
384 }
385
386 switch (e->op) {
387 case CEXPR_EQ:
388 s[++sp] = (val1 == val2);
389 break;
390 case CEXPR_NEQ:
391 s[++sp] = (val1 != val2);
392 break;
393 default:
394 BUG();
395 return 0;
396 }
397 break;
398 case CEXPR_NAMES:
399 if (sp == (CEXPR_MAXDEPTH-1))
400 return 0;
401 c = scontext;
402 if (e->attr & CEXPR_TARGET)
403 c = tcontext;
404 else if (e->attr & CEXPR_XTARGET) {
405 c = xcontext;
406 if (!c) {
407 BUG();
408 return 0;
409 }
410 }
411 if (e->attr & CEXPR_USER)
412 val1 = c->user;
413 else if (e->attr & CEXPR_ROLE)
414 val1 = c->role;
415 else if (e->attr & CEXPR_TYPE)
416 val1 = c->type;
417 else {
418 BUG();
419 return 0;
420 }
421
422 switch (e->op) {
423 case CEXPR_EQ:
424 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
425 break;
426 case CEXPR_NEQ:
427 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
428 break;
429 default:
430 BUG();
431 return 0;
432 }
433 break;
434 default:
435 BUG();
436 return 0;
437 }
438 }
439
440 BUG_ON(sp != 0);
441 return s[0];
442 }
443
444 /*
445 * security_dump_masked_av - dumps masked permissions during
446 * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
447 */
448 static int dump_masked_av_helper(void *k, void *d, void *args)
449 {
450 struct perm_datum *pdatum = d;
451 char **permission_names = args;
452
453 BUG_ON(pdatum->value < 1 || pdatum->value > 32);
454
455 permission_names[pdatum->value - 1] = (char *)k;
456
457 return 0;
458 }
459
460 static void security_dump_masked_av(struct context *scontext,
461 struct context *tcontext,
462 u16 tclass,
463 u32 permissions,
464 const char *reason)
465 {
466 struct common_datum *common_dat;
467 struct class_datum *tclass_dat;
468 struct audit_buffer *ab;
469 char *tclass_name;
470 char *scontext_name = NULL;
471 char *tcontext_name = NULL;
472 char *permission_names[32];
473 int index;
474 u32 length;
475 bool need_comma = false;
476
477 if (!permissions)
478 return;
479
480 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
481 tclass_dat = policydb.class_val_to_struct[tclass - 1];
482 common_dat = tclass_dat->comdatum;
483
484 /* init permission_names */
485 if (common_dat &&
486 hashtab_map(common_dat->permissions.table,
487 dump_masked_av_helper, permission_names) < 0)
488 goto out;
489
490 if (hashtab_map(tclass_dat->permissions.table,
491 dump_masked_av_helper, permission_names) < 0)
492 goto out;
493
494 /* get scontext/tcontext in text form */
495 if (context_struct_to_string(scontext,
496 &scontext_name, &length) < 0)
497 goto out;
498
499 if (context_struct_to_string(tcontext,
500 &tcontext_name, &length) < 0)
501 goto out;
502
503 /* audit a message */
504 ab = audit_log_start(current->audit_context,
505 GFP_ATOMIC, AUDIT_SELINUX_ERR);
506 if (!ab)
507 goto out;
508
509 audit_log_format(ab, "op=security_compute_av reason=%s "
510 "scontext=%s tcontext=%s tclass=%s perms=",
511 reason, scontext_name, tcontext_name, tclass_name);
512
513 for (index = 0; index < 32; index++) {
514 u32 mask = (1 << index);
515
516 if ((mask & permissions) == 0)
517 continue;
518
519 audit_log_format(ab, "%s%s",
520 need_comma ? "," : "",
521 permission_names[index]
522 ? permission_names[index] : "????");
523 need_comma = true;
524 }
525 audit_log_end(ab);
526 out:
527 /* release scontext/tcontext */
528 kfree(tcontext_name);
529 kfree(scontext_name);
530
531 return;
532 }
533
534 /*
535 * security_boundary_permission - drops violated permissions
536 * on boundary constraint.
537 */
538 static void type_attribute_bounds_av(struct context *scontext,
539 struct context *tcontext,
540 u16 tclass,
541 struct av_decision *avd)
542 {
543 struct context lo_scontext;
544 struct context lo_tcontext;
545 struct av_decision lo_avd;
546 struct type_datum *source;
547 struct type_datum *target;
548 u32 masked = 0;
549
550 source = flex_array_get_ptr(policydb.type_val_to_struct_array,
551 scontext->type - 1);
552 BUG_ON(!source);
553
554 target = flex_array_get_ptr(policydb.type_val_to_struct_array,
555 tcontext->type - 1);
556 BUG_ON(!target);
557
558 if (source->bounds) {
559 memset(&lo_avd, 0, sizeof(lo_avd));
560
561 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
562 lo_scontext.type = source->bounds;
563
564 context_struct_compute_av(&lo_scontext,
565 tcontext,
566 tclass,
567 &lo_avd);
568 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
569 return; /* no masked permission */
570 masked = ~lo_avd.allowed & avd->allowed;
571 }
572
573 if (target->bounds) {
574 memset(&lo_avd, 0, sizeof(lo_avd));
575
576 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
577 lo_tcontext.type = target->bounds;
578
579 context_struct_compute_av(scontext,
580 &lo_tcontext,
581 tclass,
582 &lo_avd);
583 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
584 return; /* no masked permission */
585 masked = ~lo_avd.allowed & avd->allowed;
586 }
587
588 if (source->bounds && target->bounds) {
589 memset(&lo_avd, 0, sizeof(lo_avd));
590 /*
591 * lo_scontext and lo_tcontext are already
592 * set up.
593 */
594
595 context_struct_compute_av(&lo_scontext,
596 &lo_tcontext,
597 tclass,
598 &lo_avd);
599 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
600 return; /* no masked permission */
601 masked = ~lo_avd.allowed & avd->allowed;
602 }
603
604 if (masked) {
605 /* mask violated permissions */
606 avd->allowed &= ~masked;
607
608 /* audit masked permissions */
609 security_dump_masked_av(scontext, tcontext,
610 tclass, masked, "bounds");
611 }
612 }
613
614 /*
615 * Compute access vectors based on a context structure pair for
616 * the permissions in a particular class.
617 */
618 static void context_struct_compute_av(struct context *scontext,
619 struct context *tcontext,
620 u16 tclass,
621 struct av_decision *avd)
622 {
623 struct constraint_node *constraint;
624 struct role_allow *ra;
625 struct avtab_key avkey;
626 struct avtab_node *node;
627 struct class_datum *tclass_datum;
628 struct ebitmap *sattr, *tattr;
629 struct ebitmap_node *snode, *tnode;
630 unsigned int i, j;
631
632 avd->allowed = 0;
633 avd->auditallow = 0;
634 avd->auditdeny = 0xffffffff;
635
636 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
637 if (printk_ratelimit())
638 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass);
639 return;
640 }
641
642 tclass_datum = policydb.class_val_to_struct[tclass - 1];
643
644 /*
645 * If a specific type enforcement rule was defined for
646 * this permission check, then use it.
647 */
648 avkey.target_class = tclass;
649 avkey.specified = AVTAB_AV;
650 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
651 BUG_ON(!sattr);
652 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
653 BUG_ON(!tattr);
654 ebitmap_for_each_positive_bit(sattr, snode, i) {
655 ebitmap_for_each_positive_bit(tattr, tnode, j) {
656 avkey.source_type = i + 1;
657 avkey.target_type = j + 1;
658 for (node = avtab_search_node(&policydb.te_avtab, &avkey);
659 node;
660 node = avtab_search_node_next(node, avkey.specified)) {
661 if (node->key.specified == AVTAB_ALLOWED)
662 avd->allowed |= node->datum.data;
663 else if (node->key.specified == AVTAB_AUDITALLOW)
664 avd->auditallow |= node->datum.data;
665 else if (node->key.specified == AVTAB_AUDITDENY)
666 avd->auditdeny &= node->datum.data;
667 }
668
669 /* Check conditional av table for additional permissions */
670 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
671
672 }
673 }
674
675 /*
676 * Remove any permissions prohibited by a constraint (this includes
677 * the MLS policy).
678 */
679 constraint = tclass_datum->constraints;
680 while (constraint) {
681 if ((constraint->permissions & (avd->allowed)) &&
682 !constraint_expr_eval(scontext, tcontext, NULL,
683 constraint->expr)) {
684 avd->allowed &= ~(constraint->permissions);
685 }
686 constraint = constraint->next;
687 }
688
689 /*
690 * If checking process transition permission and the
691 * role is changing, then check the (current_role, new_role)
692 * pair.
693 */
694 if (tclass == policydb.process_class &&
695 (avd->allowed & policydb.process_trans_perms) &&
696 scontext->role != tcontext->role) {
697 for (ra = policydb.role_allow; ra; ra = ra->next) {
698 if (scontext->role == ra->role &&
699 tcontext->role == ra->new_role)
700 break;
701 }
702 if (!ra)
703 avd->allowed &= ~policydb.process_trans_perms;
704 }
705
706 /*
707 * If the given source and target types have boundary
708 * constraint, lazy checks have to mask any violated
709 * permission and notice it to userspace via audit.
710 */
711 type_attribute_bounds_av(scontext, tcontext,
712 tclass, avd);
713 }
714
715 static int security_validtrans_handle_fail(struct context *ocontext,
716 struct context *ncontext,
717 struct context *tcontext,
718 u16 tclass)
719 {
720 char *o = NULL, *n = NULL, *t = NULL;
721 u32 olen, nlen, tlen;
722
723 if (context_struct_to_string(ocontext, &o, &olen))
724 goto out;
725 if (context_struct_to_string(ncontext, &n, &nlen))
726 goto out;
727 if (context_struct_to_string(tcontext, &t, &tlen))
728 goto out;
729 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
730 "security_validate_transition: denied for"
731 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
732 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
733 out:
734 kfree(o);
735 kfree(n);
736 kfree(t);
737
738 if (!selinux_enforcing)
739 return 0;
740 return -EPERM;
741 }
742
743 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
744 u16 orig_tclass)
745 {
746 struct context *ocontext;
747 struct context *ncontext;
748 struct context *tcontext;
749 struct class_datum *tclass_datum;
750 struct constraint_node *constraint;
751 u16 tclass;
752 int rc = 0;
753
754 if (!ss_initialized)
755 return 0;
756
757 read_lock(&policy_rwlock);
758
759 tclass = unmap_class(orig_tclass);
760
761 if (!tclass || tclass > policydb.p_classes.nprim) {
762 printk(KERN_ERR "SELinux: %s: unrecognized class %d\n",
763 __func__, tclass);
764 rc = -EINVAL;
765 goto out;
766 }
767 tclass_datum = policydb.class_val_to_struct[tclass - 1];
768
769 ocontext = sidtab_search(&sidtab, oldsid);
770 if (!ocontext) {
771 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
772 __func__, oldsid);
773 rc = -EINVAL;
774 goto out;
775 }
776
777 ncontext = sidtab_search(&sidtab, newsid);
778 if (!ncontext) {
779 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
780 __func__, newsid);
781 rc = -EINVAL;
782 goto out;
783 }
784
785 tcontext = sidtab_search(&sidtab, tasksid);
786 if (!tcontext) {
787 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
788 __func__, tasksid);
789 rc = -EINVAL;
790 goto out;
791 }
792
793 constraint = tclass_datum->validatetrans;
794 while (constraint) {
795 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
796 constraint->expr)) {
797 rc = security_validtrans_handle_fail(ocontext, ncontext,
798 tcontext, tclass);
799 goto out;
800 }
801 constraint = constraint->next;
802 }
803
804 out:
805 read_unlock(&policy_rwlock);
806 return rc;
807 }
808
809 /*
810 * security_bounded_transition - check whether the given
811 * transition is directed to bounded, or not.
812 * It returns 0, if @newsid is bounded by @oldsid.
813 * Otherwise, it returns error code.
814 *
815 * @oldsid : current security identifier
816 * @newsid : destinated security identifier
817 */
818 int security_bounded_transition(u32 old_sid, u32 new_sid)
819 {
820 struct context *old_context, *new_context;
821 struct type_datum *type;
822 int index;
823 int rc;
824
825 read_lock(&policy_rwlock);
826
827 rc = -EINVAL;
828 old_context = sidtab_search(&sidtab, old_sid);
829 if (!old_context) {
830 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
831 __func__, old_sid);
832 goto out;
833 }
834
835 rc = -EINVAL;
836 new_context = sidtab_search(&sidtab, new_sid);
837 if (!new_context) {
838 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
839 __func__, new_sid);
840 goto out;
841 }
842
843 rc = 0;
844 /* type/domain unchanged */
845 if (old_context->type == new_context->type)
846 goto out;
847
848 index = new_context->type;
849 while (true) {
850 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
851 index - 1);
852 BUG_ON(!type);
853
854 /* not bounded anymore */
855 rc = -EPERM;
856 if (!type->bounds)
857 break;
858
859 /* @newsid is bounded by @oldsid */
860 rc = 0;
861 if (type->bounds == old_context->type)
862 break;
863
864 index = type->bounds;
865 }
866
867 if (rc) {
868 char *old_name = NULL;
869 char *new_name = NULL;
870 u32 length;
871
872 if (!context_struct_to_string(old_context,
873 &old_name, &length) &&
874 !context_struct_to_string(new_context,
875 &new_name, &length)) {
876 audit_log(current->audit_context,
877 GFP_ATOMIC, AUDIT_SELINUX_ERR,
878 "op=security_bounded_transition "
879 "result=denied "
880 "oldcontext=%s newcontext=%s",
881 old_name, new_name);
882 }
883 kfree(new_name);
884 kfree(old_name);
885 }
886 out:
887 read_unlock(&policy_rwlock);
888
889 return rc;
890 }
891
892 static void avd_init(struct av_decision *avd)
893 {
894 avd->allowed = 0;
895 avd->auditallow = 0;
896 avd->auditdeny = 0xffffffff;
897 avd->seqno = latest_granting;
898 avd->flags = 0;
899 }
900
901
902 /**
903 * security_compute_av - Compute access vector decisions.
904 * @ssid: source security identifier
905 * @tsid: target security identifier
906 * @tclass: target security class
907 * @avd: access vector decisions
908 *
909 * Compute a set of access vector decisions based on the
910 * SID pair (@ssid, @tsid) for the permissions in @tclass.
911 */
912 void security_compute_av(u32 ssid,
913 u32 tsid,
914 u16 orig_tclass,
915 struct av_decision *avd)
916 {
917 u16 tclass;
918 struct context *scontext = NULL, *tcontext = NULL;
919
920 read_lock(&policy_rwlock);
921 avd_init(avd);
922 if (!ss_initialized)
923 goto allow;
924
925 scontext = sidtab_search(&sidtab, ssid);
926 if (!scontext) {
927 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
928 __func__, ssid);
929 goto out;
930 }
931
932 /* permissive domain? */
933 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
934 avd->flags |= AVD_FLAGS_PERMISSIVE;
935
936 tcontext = sidtab_search(&sidtab, tsid);
937 if (!tcontext) {
938 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
939 __func__, tsid);
940 goto out;
941 }
942
943 tclass = unmap_class(orig_tclass);
944 if (unlikely(orig_tclass && !tclass)) {
945 if (policydb.allow_unknown)
946 goto allow;
947 goto out;
948 }
949 context_struct_compute_av(scontext, tcontext, tclass, avd);
950 map_decision(orig_tclass, avd, policydb.allow_unknown);
951 out:
952 read_unlock(&policy_rwlock);
953 return;
954 allow:
955 avd->allowed = 0xffffffff;
956 goto out;
957 }
958
959 void security_compute_av_user(u32 ssid,
960 u32 tsid,
961 u16 tclass,
962 struct av_decision *avd)
963 {
964 struct context *scontext = NULL, *tcontext = NULL;
965
966 read_lock(&policy_rwlock);
967 avd_init(avd);
968 if (!ss_initialized)
969 goto allow;
970
971 scontext = sidtab_search(&sidtab, ssid);
972 if (!scontext) {
973 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
974 __func__, ssid);
975 goto out;
976 }
977
978 /* permissive domain? */
979 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
980 avd->flags |= AVD_FLAGS_PERMISSIVE;
981
982 tcontext = sidtab_search(&sidtab, tsid);
983 if (!tcontext) {
984 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
985 __func__, tsid);
986 goto out;
987 }
988
989 if (unlikely(!tclass)) {
990 if (policydb.allow_unknown)
991 goto allow;
992 goto out;
993 }
994
995 context_struct_compute_av(scontext, tcontext, tclass, avd);
996 out:
997 read_unlock(&policy_rwlock);
998 return;
999 allow:
1000 avd->allowed = 0xffffffff;
1001 goto out;
1002 }
1003
1004 /*
1005 * Write the security context string representation of
1006 * the context structure `context' into a dynamically
1007 * allocated string of the correct size. Set `*scontext'
1008 * to point to this string and set `*scontext_len' to
1009 * the length of the string.
1010 */
1011 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1012 {
1013 char *scontextp;
1014
1015 if (scontext)
1016 *scontext = NULL;
1017 *scontext_len = 0;
1018
1019 if (context->len) {
1020 *scontext_len = context->len;
1021 *scontext = kstrdup(context->str, GFP_ATOMIC);
1022 if (!(*scontext))
1023 return -ENOMEM;
1024 return 0;
1025 }
1026
1027 /* Compute the size of the context. */
1028 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1029 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1030 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1031 *scontext_len += mls_compute_context_len(context);
1032
1033 if (!scontext)
1034 return 0;
1035
1036 /* Allocate space for the context; caller must free this space. */
1037 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1038 if (!scontextp)
1039 return -ENOMEM;
1040 *scontext = scontextp;
1041
1042 /*
1043 * Copy the user name, role name and type name into the context.
1044 */
1045 sprintf(scontextp, "%s:%s:%s",
1046 sym_name(&policydb, SYM_USERS, context->user - 1),
1047 sym_name(&policydb, SYM_ROLES, context->role - 1),
1048 sym_name(&policydb, SYM_TYPES, context->type - 1));
1049 scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1050 1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1051 1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1052
1053 mls_sid_to_context(context, &scontextp);
1054
1055 *scontextp = 0;
1056
1057 return 0;
1058 }
1059
1060 #include "initial_sid_to_string.h"
1061
1062 const char *security_get_initial_sid_context(u32 sid)
1063 {
1064 if (unlikely(sid > SECINITSID_NUM))
1065 return NULL;
1066 return initial_sid_to_string[sid];
1067 }
1068
1069 static int security_sid_to_context_core(u32 sid, char **scontext,
1070 u32 *scontext_len, int force)
1071 {
1072 struct context *context;
1073 int rc = 0;
1074
1075 if (scontext)
1076 *scontext = NULL;
1077 *scontext_len = 0;
1078
1079 if (!ss_initialized) {
1080 if (sid <= SECINITSID_NUM) {
1081 char *scontextp;
1082
1083 *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1084 if (!scontext)
1085 goto out;
1086 scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1087 if (!scontextp) {
1088 rc = -ENOMEM;
1089 goto out;
1090 }
1091 strcpy(scontextp, initial_sid_to_string[sid]);
1092 *scontext = scontextp;
1093 goto out;
1094 }
1095 printk(KERN_ERR "SELinux: %s: called before initial "
1096 "load_policy on unknown SID %d\n", __func__, sid);
1097 rc = -EINVAL;
1098 goto out;
1099 }
1100 read_lock(&policy_rwlock);
1101 if (force)
1102 context = sidtab_search_force(&sidtab, sid);
1103 else
1104 context = sidtab_search(&sidtab, sid);
1105 if (!context) {
1106 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1107 __func__, sid);
1108 rc = -EINVAL;
1109 goto out_unlock;
1110 }
1111 rc = context_struct_to_string(context, scontext, scontext_len);
1112 out_unlock:
1113 read_unlock(&policy_rwlock);
1114 out:
1115 return rc;
1116
1117 }
1118
1119 /**
1120 * security_sid_to_context - Obtain a context for a given SID.
1121 * @sid: security identifier, SID
1122 * @scontext: security context
1123 * @scontext_len: length in bytes
1124 *
1125 * Write the string representation of the context associated with @sid
1126 * into a dynamically allocated string of the correct size. Set @scontext
1127 * to point to this string and set @scontext_len to the length of the string.
1128 */
1129 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1130 {
1131 return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1132 }
1133
1134 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1135 {
1136 return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1137 }
1138
1139 /*
1140 * Caveat: Mutates scontext.
1141 */
1142 static int string_to_context_struct(struct policydb *pol,
1143 struct sidtab *sidtabp,
1144 char *scontext,
1145 u32 scontext_len,
1146 struct context *ctx,
1147 u32 def_sid)
1148 {
1149 struct role_datum *role;
1150 struct type_datum *typdatum;
1151 struct user_datum *usrdatum;
1152 char *scontextp, *p, oldc;
1153 int rc = 0;
1154
1155 context_init(ctx);
1156
1157 /* Parse the security context. */
1158
1159 rc = -EINVAL;
1160 scontextp = (char *) scontext;
1161
1162 /* Extract the user. */
1163 p = scontextp;
1164 while (*p && *p != ':')
1165 p++;
1166
1167 if (*p == 0)
1168 goto out;
1169
1170 *p++ = 0;
1171
1172 usrdatum = hashtab_search(pol->p_users.table, scontextp);
1173 if (!usrdatum)
1174 goto out;
1175
1176 ctx->user = usrdatum->value;
1177
1178 /* Extract role. */
1179 scontextp = p;
1180 while (*p && *p != ':')
1181 p++;
1182
1183 if (*p == 0)
1184 goto out;
1185
1186 *p++ = 0;
1187
1188 role = hashtab_search(pol->p_roles.table, scontextp);
1189 if (!role)
1190 goto out;
1191 ctx->role = role->value;
1192
1193 /* Extract type. */
1194 scontextp = p;
1195 while (*p && *p != ':')
1196 p++;
1197 oldc = *p;
1198 *p++ = 0;
1199
1200 typdatum = hashtab_search(pol->p_types.table, scontextp);
1201 if (!typdatum || typdatum->attribute)
1202 goto out;
1203
1204 ctx->type = typdatum->value;
1205
1206 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1207 if (rc)
1208 goto out;
1209
1210 rc = -EINVAL;
1211 if ((p - scontext) < scontext_len)
1212 goto out;
1213
1214 /* Check the validity of the new context. */
1215 if (!policydb_context_isvalid(pol, ctx))
1216 goto out;
1217 rc = 0;
1218 out:
1219 if (rc)
1220 context_destroy(ctx);
1221 return rc;
1222 }
1223
1224 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1225 u32 *sid, u32 def_sid, gfp_t gfp_flags,
1226 int force)
1227 {
1228 char *scontext2, *str = NULL;
1229 struct context context;
1230 int rc = 0;
1231
1232 if (!ss_initialized) {
1233 int i;
1234
1235 for (i = 1; i < SECINITSID_NUM; i++) {
1236 if (!strcmp(initial_sid_to_string[i], scontext)) {
1237 *sid = i;
1238 return 0;
1239 }
1240 }
1241 *sid = SECINITSID_KERNEL;
1242 return 0;
1243 }
1244 *sid = SECSID_NULL;
1245
1246 /* Copy the string so that we can modify the copy as we parse it. */
1247 scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1248 if (!scontext2)
1249 return -ENOMEM;
1250 memcpy(scontext2, scontext, scontext_len);
1251 scontext2[scontext_len] = 0;
1252
1253 if (force) {
1254 /* Save another copy for storing in uninterpreted form */
1255 rc = -ENOMEM;
1256 str = kstrdup(scontext2, gfp_flags);
1257 if (!str)
1258 goto out;
1259 }
1260
1261 read_lock(&policy_rwlock);
1262 rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1263 scontext_len, &context, def_sid);
1264 if (rc == -EINVAL && force) {
1265 context.str = str;
1266 context.len = scontext_len;
1267 str = NULL;
1268 } else if (rc)
1269 goto out_unlock;
1270 rc = sidtab_context_to_sid(&sidtab, &context, sid);
1271 context_destroy(&context);
1272 out_unlock:
1273 read_unlock(&policy_rwlock);
1274 out:
1275 kfree(scontext2);
1276 kfree(str);
1277 return rc;
1278 }
1279
1280 /**
1281 * security_context_to_sid - Obtain a SID for a given security context.
1282 * @scontext: security context
1283 * @scontext_len: length in bytes
1284 * @sid: security identifier, SID
1285 *
1286 * Obtains a SID associated with the security context that
1287 * has the string representation specified by @scontext.
1288 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1289 * memory is available, or 0 on success.
1290 */
1291 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1292 {
1293 return security_context_to_sid_core(scontext, scontext_len,
1294 sid, SECSID_NULL, GFP_KERNEL, 0);
1295 }
1296
1297 /**
1298 * security_context_to_sid_default - Obtain a SID for a given security context,
1299 * falling back to specified default if needed.
1300 *
1301 * @scontext: security context
1302 * @scontext_len: length in bytes
1303 * @sid: security identifier, SID
1304 * @def_sid: default SID to assign on error
1305 *
1306 * Obtains a SID associated with the security context that
1307 * has the string representation specified by @scontext.
1308 * The default SID is passed to the MLS layer to be used to allow
1309 * kernel labeling of the MLS field if the MLS field is not present
1310 * (for upgrading to MLS without full relabel).
1311 * Implicitly forces adding of the context even if it cannot be mapped yet.
1312 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1313 * memory is available, or 0 on success.
1314 */
1315 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1316 u32 *sid, u32 def_sid, gfp_t gfp_flags)
1317 {
1318 return security_context_to_sid_core(scontext, scontext_len,
1319 sid, def_sid, gfp_flags, 1);
1320 }
1321
1322 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1323 u32 *sid)
1324 {
1325 return security_context_to_sid_core(scontext, scontext_len,
1326 sid, SECSID_NULL, GFP_KERNEL, 1);
1327 }
1328
1329 static int compute_sid_handle_invalid_context(
1330 struct context *scontext,
1331 struct context *tcontext,
1332 u16 tclass,
1333 struct context *newcontext)
1334 {
1335 char *s = NULL, *t = NULL, *n = NULL;
1336 u32 slen, tlen, nlen;
1337
1338 if (context_struct_to_string(scontext, &s, &slen))
1339 goto out;
1340 if (context_struct_to_string(tcontext, &t, &tlen))
1341 goto out;
1342 if (context_struct_to_string(newcontext, &n, &nlen))
1343 goto out;
1344 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1345 "security_compute_sid: invalid context %s"
1346 " for scontext=%s"
1347 " tcontext=%s"
1348 " tclass=%s",
1349 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1350 out:
1351 kfree(s);
1352 kfree(t);
1353 kfree(n);
1354 if (!selinux_enforcing)
1355 return 0;
1356 return -EACCES;
1357 }
1358
1359 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1360 u32 stype, u32 ttype, u16 tclass,
1361 const char *objname)
1362 {
1363 struct filename_trans ft;
1364 struct filename_trans_datum *otype;
1365
1366 /*
1367 * Most filename trans rules are going to live in specific directories
1368 * like /dev or /var/run. This bitmap will quickly skip rule searches
1369 * if the ttype does not contain any rules.
1370 */
1371 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1372 return;
1373
1374 ft.stype = stype;
1375 ft.ttype = ttype;
1376 ft.tclass = tclass;
1377 ft.name = objname;
1378
1379 otype = hashtab_search(p->filename_trans, &ft);
1380 if (otype)
1381 newcontext->type = otype->otype;
1382 }
1383
1384 static int security_compute_sid(u32 ssid,
1385 u32 tsid,
1386 u16 orig_tclass,
1387 u32 specified,
1388 const char *objname,
1389 u32 *out_sid,
1390 bool kern)
1391 {
1392 struct context *scontext = NULL, *tcontext = NULL, newcontext;
1393 struct role_trans *roletr = NULL;
1394 struct avtab_key avkey;
1395 struct avtab_datum *avdatum;
1396 struct avtab_node *node;
1397 u16 tclass;
1398 int rc = 0;
1399 bool sock;
1400
1401 if (!ss_initialized) {
1402 switch (orig_tclass) {
1403 case SECCLASS_PROCESS: /* kernel value */
1404 *out_sid = ssid;
1405 break;
1406 default:
1407 *out_sid = tsid;
1408 break;
1409 }
1410 goto out;
1411 }
1412
1413 context_init(&newcontext);
1414
1415 read_lock(&policy_rwlock);
1416
1417 if (kern) {
1418 tclass = unmap_class(orig_tclass);
1419 sock = security_is_socket_class(orig_tclass);
1420 } else {
1421 tclass = orig_tclass;
1422 sock = security_is_socket_class(map_class(tclass));
1423 }
1424
1425 scontext = sidtab_search(&sidtab, ssid);
1426 if (!scontext) {
1427 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1428 __func__, ssid);
1429 rc = -EINVAL;
1430 goto out_unlock;
1431 }
1432 tcontext = sidtab_search(&sidtab, tsid);
1433 if (!tcontext) {
1434 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
1435 __func__, tsid);
1436 rc = -EINVAL;
1437 goto out_unlock;
1438 }
1439
1440 /* Set the user identity. */
1441 switch (specified) {
1442 case AVTAB_TRANSITION:
1443 case AVTAB_CHANGE:
1444 /* Use the process user identity. */
1445 newcontext.user = scontext->user;
1446 break;
1447 case AVTAB_MEMBER:
1448 /* Use the related object owner. */
1449 newcontext.user = tcontext->user;
1450 break;
1451 }
1452
1453 /* Set the role and type to default values. */
1454 if ((tclass == policydb.process_class) || (sock == true)) {
1455 /* Use the current role and type of process. */
1456 newcontext.role = scontext->role;
1457 newcontext.type = scontext->type;
1458 } else {
1459 /* Use the well-defined object role. */
1460 newcontext.role = OBJECT_R_VAL;
1461 /* Use the type of the related object. */
1462 newcontext.type = tcontext->type;
1463 }
1464
1465 /* Look for a type transition/member/change rule. */
1466 avkey.source_type = scontext->type;
1467 avkey.target_type = tcontext->type;
1468 avkey.target_class = tclass;
1469 avkey.specified = specified;
1470 avdatum = avtab_search(&policydb.te_avtab, &avkey);
1471
1472 /* If no permanent rule, also check for enabled conditional rules */
1473 if (!avdatum) {
1474 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1475 for (; node; node = avtab_search_node_next(node, specified)) {
1476 if (node->key.specified & AVTAB_ENABLED) {
1477 avdatum = &node->datum;
1478 break;
1479 }
1480 }
1481 }
1482
1483 if (avdatum) {
1484 /* Use the type from the type transition/member/change rule. */
1485 newcontext.type = avdatum->data;
1486 }
1487
1488 /* if we have a objname this is a file trans check so check those rules */
1489 if (objname)
1490 filename_compute_type(&policydb, &newcontext, scontext->type,
1491 tcontext->type, tclass, objname);
1492
1493 /* Check for class-specific changes. */
1494 if (specified & AVTAB_TRANSITION) {
1495 /* Look for a role transition rule. */
1496 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1497 if ((roletr->role == scontext->role) &&
1498 (roletr->type == tcontext->type) &&
1499 (roletr->tclass == tclass)) {
1500 /* Use the role transition rule. */
1501 newcontext.role = roletr->new_role;
1502 break;
1503 }
1504 }
1505 }
1506
1507 /* Set the MLS attributes.
1508 This is done last because it may allocate memory. */
1509 rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1510 &newcontext, sock);
1511 if (rc)
1512 goto out_unlock;
1513
1514 /* Check the validity of the context. */
1515 if (!policydb_context_isvalid(&policydb, &newcontext)) {
1516 rc = compute_sid_handle_invalid_context(scontext,
1517 tcontext,
1518 tclass,
1519 &newcontext);
1520 if (rc)
1521 goto out_unlock;
1522 }
1523 /* Obtain the sid for the context. */
1524 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1525 out_unlock:
1526 read_unlock(&policy_rwlock);
1527 context_destroy(&newcontext);
1528 out:
1529 return rc;
1530 }
1531
1532 /**
1533 * security_transition_sid - Compute the SID for a new subject/object.
1534 * @ssid: source security identifier
1535 * @tsid: target security identifier
1536 * @tclass: target security class
1537 * @out_sid: security identifier for new subject/object
1538 *
1539 * Compute a SID to use for labeling a new subject or object in the
1540 * class @tclass based on a SID pair (@ssid, @tsid).
1541 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1542 * if insufficient memory is available, or %0 if the new SID was
1543 * computed successfully.
1544 */
1545 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1546 const struct qstr *qstr, u32 *out_sid)
1547 {
1548 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1549 qstr ? qstr->name : NULL, out_sid, true);
1550 }
1551
1552 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1553 const char *objname, u32 *out_sid)
1554 {
1555 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1556 objname, out_sid, false);
1557 }
1558
1559 /**
1560 * security_member_sid - Compute the SID for member selection.
1561 * @ssid: source security identifier
1562 * @tsid: target security identifier
1563 * @tclass: target security class
1564 * @out_sid: security identifier for selected member
1565 *
1566 * Compute a SID to use when selecting a member of a polyinstantiated
1567 * object of class @tclass based on a SID pair (@ssid, @tsid).
1568 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1569 * if insufficient memory is available, or %0 if the SID was
1570 * computed successfully.
1571 */
1572 int security_member_sid(u32 ssid,
1573 u32 tsid,
1574 u16 tclass,
1575 u32 *out_sid)
1576 {
1577 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1578 out_sid, false);
1579 }
1580
1581 /**
1582 * security_change_sid - Compute the SID for object relabeling.
1583 * @ssid: source security identifier
1584 * @tsid: target security identifier
1585 * @tclass: target security class
1586 * @out_sid: security identifier for selected member
1587 *
1588 * Compute a SID to use for relabeling an object of class @tclass
1589 * based on a SID pair (@ssid, @tsid).
1590 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1591 * if insufficient memory is available, or %0 if the SID was
1592 * computed successfully.
1593 */
1594 int security_change_sid(u32 ssid,
1595 u32 tsid,
1596 u16 tclass,
1597 u32 *out_sid)
1598 {
1599 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1600 out_sid, false);
1601 }
1602
1603 /* Clone the SID into the new SID table. */
1604 static int clone_sid(u32 sid,
1605 struct context *context,
1606 void *arg)
1607 {
1608 struct sidtab *s = arg;
1609
1610 if (sid > SECINITSID_NUM)
1611 return sidtab_insert(s, sid, context);
1612 else
1613 return 0;
1614 }
1615
1616 static inline int convert_context_handle_invalid_context(struct context *context)
1617 {
1618 char *s;
1619 u32 len;
1620
1621 if (selinux_enforcing)
1622 return -EINVAL;
1623
1624 if (!context_struct_to_string(context, &s, &len)) {
1625 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s);
1626 kfree(s);
1627 }
1628 return 0;
1629 }
1630
1631 struct convert_context_args {
1632 struct policydb *oldp;
1633 struct policydb *newp;
1634 };
1635
1636 /*
1637 * Convert the values in the security context
1638 * structure `c' from the values specified
1639 * in the policy `p->oldp' to the values specified
1640 * in the policy `p->newp'. Verify that the
1641 * context is valid under the new policy.
1642 */
1643 static int convert_context(u32 key,
1644 struct context *c,
1645 void *p)
1646 {
1647 struct convert_context_args *args;
1648 struct context oldc;
1649 struct ocontext *oc;
1650 struct mls_range *range;
1651 struct role_datum *role;
1652 struct type_datum *typdatum;
1653 struct user_datum *usrdatum;
1654 char *s;
1655 u32 len;
1656 int rc = 0;
1657
1658 if (key <= SECINITSID_NUM)
1659 goto out;
1660
1661 args = p;
1662
1663 if (c->str) {
1664 struct context ctx;
1665
1666 rc = -ENOMEM;
1667 s = kstrdup(c->str, GFP_KERNEL);
1668 if (!s)
1669 goto out;
1670
1671 rc = string_to_context_struct(args->newp, NULL, s,
1672 c->len, &ctx, SECSID_NULL);
1673 kfree(s);
1674 if (!rc) {
1675 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n",
1676 c->str);
1677 /* Replace string with mapped representation. */
1678 kfree(c->str);
1679 memcpy(c, &ctx, sizeof(*c));
1680 goto out;
1681 } else if (rc == -EINVAL) {
1682 /* Retain string representation for later mapping. */
1683 rc = 0;
1684 goto out;
1685 } else {
1686 /* Other error condition, e.g. ENOMEM. */
1687 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n",
1688 c->str, -rc);
1689 goto out;
1690 }
1691 }
1692
1693 rc = context_cpy(&oldc, c);
1694 if (rc)
1695 goto out;
1696
1697 /* Convert the user. */
1698 rc = -EINVAL;
1699 usrdatum = hashtab_search(args->newp->p_users.table,
1700 sym_name(args->oldp, SYM_USERS, c->user - 1));
1701 if (!usrdatum)
1702 goto bad;
1703 c->user = usrdatum->value;
1704
1705 /* Convert the role. */
1706 rc = -EINVAL;
1707 role = hashtab_search(args->newp->p_roles.table,
1708 sym_name(args->oldp, SYM_ROLES, c->role - 1));
1709 if (!role)
1710 goto bad;
1711 c->role = role->value;
1712
1713 /* Convert the type. */
1714 rc = -EINVAL;
1715 typdatum = hashtab_search(args->newp->p_types.table,
1716 sym_name(args->oldp, SYM_TYPES, c->type - 1));
1717 if (!typdatum)
1718 goto bad;
1719 c->type = typdatum->value;
1720
1721 /* Convert the MLS fields if dealing with MLS policies */
1722 if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1723 rc = mls_convert_context(args->oldp, args->newp, c);
1724 if (rc)
1725 goto bad;
1726 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1727 /*
1728 * Switching between MLS and non-MLS policy:
1729 * free any storage used by the MLS fields in the
1730 * context for all existing entries in the sidtab.
1731 */
1732 mls_context_destroy(c);
1733 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1734 /*
1735 * Switching between non-MLS and MLS policy:
1736 * ensure that the MLS fields of the context for all
1737 * existing entries in the sidtab are filled in with a
1738 * suitable default value, likely taken from one of the
1739 * initial SIDs.
1740 */
1741 oc = args->newp->ocontexts[OCON_ISID];
1742 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1743 oc = oc->next;
1744 rc = -EINVAL;
1745 if (!oc) {
1746 printk(KERN_ERR "SELinux: unable to look up"
1747 " the initial SIDs list\n");
1748 goto bad;
1749 }
1750 range = &oc->context[0].range;
1751 rc = mls_range_set(c, range);
1752 if (rc)
1753 goto bad;
1754 }
1755
1756 /* Check the validity of the new context. */
1757 if (!policydb_context_isvalid(args->newp, c)) {
1758 rc = convert_context_handle_invalid_context(&oldc);
1759 if (rc)
1760 goto bad;
1761 }
1762
1763 context_destroy(&oldc);
1764
1765 rc = 0;
1766 out:
1767 return rc;
1768 bad:
1769 /* Map old representation to string and save it. */
1770 rc = context_struct_to_string(&oldc, &s, &len);
1771 if (rc)
1772 return rc;
1773 context_destroy(&oldc);
1774 context_destroy(c);
1775 c->str = s;
1776 c->len = len;
1777 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n",
1778 c->str);
1779 rc = 0;
1780 goto out;
1781 }
1782
1783 static void security_load_policycaps(void)
1784 {
1785 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1786 POLICYDB_CAPABILITY_NETPEER);
1787 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1788 POLICYDB_CAPABILITY_OPENPERM);
1789 }
1790
1791 static int security_preserve_bools(struct policydb *p);
1792
1793 /**
1794 * security_load_policy - Load a security policy configuration.
1795 * @data: binary policy data
1796 * @len: length of data in bytes
1797 *
1798 * Load a new set of security policy configuration data,
1799 * validate it and convert the SID table as necessary.
1800 * This function will flush the access vector cache after
1801 * loading the new policy.
1802 */
1803 int security_load_policy(void *data, size_t len)
1804 {
1805 struct policydb oldpolicydb, newpolicydb;
1806 struct sidtab oldsidtab, newsidtab;
1807 struct selinux_mapping *oldmap, *map = NULL;
1808 struct convert_context_args args;
1809 u32 seqno;
1810 u16 map_size;
1811 int rc = 0;
1812 struct policy_file file = { data, len }, *fp = &file;
1813
1814 if (!ss_initialized) {
1815 avtab_cache_init();
1816 rc = policydb_read(&policydb, fp);
1817 if (rc) {
1818 avtab_cache_destroy();
1819 return rc;
1820 }
1821
1822 policydb.len = len;
1823 rc = selinux_set_mapping(&policydb, secclass_map,
1824 &current_mapping,
1825 &current_mapping_size);
1826 if (rc) {
1827 policydb_destroy(&policydb);
1828 avtab_cache_destroy();
1829 return rc;
1830 }
1831
1832 rc = policydb_load_isids(&policydb, &sidtab);
1833 if (rc) {
1834 policydb_destroy(&policydb);
1835 avtab_cache_destroy();
1836 return rc;
1837 }
1838
1839 security_load_policycaps();
1840 ss_initialized = 1;
1841 seqno = ++latest_granting;
1842 selinux_complete_init();
1843 avc_ss_reset(seqno);
1844 selnl_notify_policyload(seqno);
1845 selinux_status_update_policyload(seqno);
1846 selinux_netlbl_cache_invalidate();
1847 selinux_xfrm_notify_policyload();
1848 return 0;
1849 }
1850
1851 #if 0
1852 sidtab_hash_eval(&sidtab, "sids");
1853 #endif
1854
1855 rc = policydb_read(&newpolicydb, fp);
1856 if (rc)
1857 return rc;
1858
1859 newpolicydb.len = len;
1860 /* If switching between different policy types, log MLS status */
1861 if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1862 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1863 else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1864 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1865
1866 rc = policydb_load_isids(&newpolicydb, &newsidtab);
1867 if (rc) {
1868 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n");
1869 policydb_destroy(&newpolicydb);
1870 return rc;
1871 }
1872
1873 rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1874 if (rc)
1875 goto err;
1876
1877 rc = security_preserve_bools(&newpolicydb);
1878 if (rc) {
1879 printk(KERN_ERR "SELinux: unable to preserve booleans\n");
1880 goto err;
1881 }
1882
1883 /* Clone the SID table. */
1884 sidtab_shutdown(&sidtab);
1885
1886 rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1887 if (rc)
1888 goto err;
1889
1890 /*
1891 * Convert the internal representations of contexts
1892 * in the new SID table.
1893 */
1894 args.oldp = &policydb;
1895 args.newp = &newpolicydb;
1896 rc = sidtab_map(&newsidtab, convert_context, &args);
1897 if (rc) {
1898 printk(KERN_ERR "SELinux: unable to convert the internal"
1899 " representation of contexts in the new SID"
1900 " table\n");
1901 goto err;
1902 }
1903
1904 /* Save the old policydb and SID table to free later. */
1905 memcpy(&oldpolicydb, &policydb, sizeof policydb);
1906 sidtab_set(&oldsidtab, &sidtab);
1907
1908 /* Install the new policydb and SID table. */
1909 write_lock_irq(&policy_rwlock);
1910 memcpy(&policydb, &newpolicydb, sizeof policydb);
1911 sidtab_set(&sidtab, &newsidtab);
1912 security_load_policycaps();
1913 oldmap = current_mapping;
1914 current_mapping = map;
1915 current_mapping_size = map_size;
1916 seqno = ++latest_granting;
1917 write_unlock_irq(&policy_rwlock);
1918
1919 /* Free the old policydb and SID table. */
1920 policydb_destroy(&oldpolicydb);
1921 sidtab_destroy(&oldsidtab);
1922 kfree(oldmap);
1923
1924 avc_ss_reset(seqno);
1925 selnl_notify_policyload(seqno);
1926 selinux_status_update_policyload(seqno);
1927 selinux_netlbl_cache_invalidate();
1928 selinux_xfrm_notify_policyload();
1929
1930 return 0;
1931
1932 err:
1933 kfree(map);
1934 sidtab_destroy(&newsidtab);
1935 policydb_destroy(&newpolicydb);
1936 return rc;
1937
1938 }
1939
1940 size_t security_policydb_len(void)
1941 {
1942 size_t len;
1943
1944 read_lock(&policy_rwlock);
1945 len = policydb.len;
1946 read_unlock(&policy_rwlock);
1947
1948 return len;
1949 }
1950
1951 /**
1952 * security_port_sid - Obtain the SID for a port.
1953 * @protocol: protocol number
1954 * @port: port number
1955 * @out_sid: security identifier
1956 */
1957 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1958 {
1959 struct ocontext *c;
1960 int rc = 0;
1961
1962 read_lock(&policy_rwlock);
1963
1964 c = policydb.ocontexts[OCON_PORT];
1965 while (c) {
1966 if (c->u.port.protocol == protocol &&
1967 c->u.port.low_port <= port &&
1968 c->u.port.high_port >= port)
1969 break;
1970 c = c->next;
1971 }
1972
1973 if (c) {
1974 if (!c->sid[0]) {
1975 rc = sidtab_context_to_sid(&sidtab,
1976 &c->context[0],
1977 &c->sid[0]);
1978 if (rc)
1979 goto out;
1980 }
1981 *out_sid = c->sid[0];
1982 } else {
1983 *out_sid = SECINITSID_PORT;
1984 }
1985
1986 out:
1987 read_unlock(&policy_rwlock);
1988 return rc;
1989 }
1990
1991 /**
1992 * security_netif_sid - Obtain the SID for a network interface.
1993 * @name: interface name
1994 * @if_sid: interface SID
1995 */
1996 int security_netif_sid(char *name, u32 *if_sid)
1997 {
1998 int rc = 0;
1999 struct ocontext *c;
2000
2001 read_lock(&policy_rwlock);
2002
2003 c = policydb.ocontexts[OCON_NETIF];
2004 while (c) {
2005 if (strcmp(name, c->u.name) == 0)
2006 break;
2007 c = c->next;
2008 }
2009
2010 if (c) {
2011 if (!c->sid[0] || !c->sid[1]) {
2012 rc = sidtab_context_to_sid(&sidtab,
2013 &c->context[0],
2014 &c->sid[0]);
2015 if (rc)
2016 goto out;
2017 rc = sidtab_context_to_sid(&sidtab,
2018 &c->context[1],
2019 &c->sid[1]);
2020 if (rc)
2021 goto out;
2022 }
2023 *if_sid = c->sid[0];
2024 } else
2025 *if_sid = SECINITSID_NETIF;
2026
2027 out:
2028 read_unlock(&policy_rwlock);
2029 return rc;
2030 }
2031
2032 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2033 {
2034 int i, fail = 0;
2035
2036 for (i = 0; i < 4; i++)
2037 if (addr[i] != (input[i] & mask[i])) {
2038 fail = 1;
2039 break;
2040 }
2041
2042 return !fail;
2043 }
2044
2045 /**
2046 * security_node_sid - Obtain the SID for a node (host).
2047 * @domain: communication domain aka address family
2048 * @addrp: address
2049 * @addrlen: address length in bytes
2050 * @out_sid: security identifier
2051 */
2052 int security_node_sid(u16 domain,
2053 void *addrp,
2054 u32 addrlen,
2055 u32 *out_sid)
2056 {
2057 int rc;
2058 struct ocontext *c;
2059
2060 read_lock(&policy_rwlock);
2061
2062 switch (domain) {
2063 case AF_INET: {
2064 u32 addr;
2065
2066 rc = -EINVAL;
2067 if (addrlen != sizeof(u32))
2068 goto out;
2069
2070 addr = *((u32 *)addrp);
2071
2072 c = policydb.ocontexts[OCON_NODE];
2073 while (c) {
2074 if (c->u.node.addr == (addr & c->u.node.mask))
2075 break;
2076 c = c->next;
2077 }
2078 break;
2079 }
2080
2081 case AF_INET6:
2082 rc = -EINVAL;
2083 if (addrlen != sizeof(u64) * 2)
2084 goto out;
2085 c = policydb.ocontexts[OCON_NODE6];
2086 while (c) {
2087 if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2088 c->u.node6.mask))
2089 break;
2090 c = c->next;
2091 }
2092 break;
2093
2094 default:
2095 rc = 0;
2096 *out_sid = SECINITSID_NODE;
2097 goto out;
2098 }
2099
2100 if (c) {
2101 if (!c->sid[0]) {
2102 rc = sidtab_context_to_sid(&sidtab,
2103 &c->context[0],
2104 &c->sid[0]);
2105 if (rc)
2106 goto out;
2107 }
2108 *out_sid = c->sid[0];
2109 } else {
2110 *out_sid = SECINITSID_NODE;
2111 }
2112
2113 rc = 0;
2114 out:
2115 read_unlock(&policy_rwlock);
2116 return rc;
2117 }
2118
2119 #define SIDS_NEL 25
2120
2121 /**
2122 * security_get_user_sids - Obtain reachable SIDs for a user.
2123 * @fromsid: starting SID
2124 * @username: username
2125 * @sids: array of reachable SIDs for user
2126 * @nel: number of elements in @sids
2127 *
2128 * Generate the set of SIDs for legal security contexts
2129 * for a given user that can be reached by @fromsid.
2130 * Set *@sids to point to a dynamically allocated
2131 * array containing the set of SIDs. Set *@nel to the
2132 * number of elements in the array.
2133 */
2134
2135 int security_get_user_sids(u32 fromsid,
2136 char *username,
2137 u32 **sids,
2138 u32 *nel)
2139 {
2140 struct context *fromcon, usercon;
2141 u32 *mysids = NULL, *mysids2, sid;
2142 u32 mynel = 0, maxnel = SIDS_NEL;
2143 struct user_datum *user;
2144 struct role_datum *role;
2145 struct ebitmap_node *rnode, *tnode;
2146 int rc = 0, i, j;
2147
2148 *sids = NULL;
2149 *nel = 0;
2150
2151 if (!ss_initialized)
2152 goto out;
2153
2154 read_lock(&policy_rwlock);
2155
2156 context_init(&usercon);
2157
2158 rc = -EINVAL;
2159 fromcon = sidtab_search(&sidtab, fromsid);
2160 if (!fromcon)
2161 goto out_unlock;
2162
2163 rc = -EINVAL;
2164 user = hashtab_search(policydb.p_users.table, username);
2165 if (!user)
2166 goto out_unlock;
2167
2168 usercon.user = user->value;
2169
2170 rc = -ENOMEM;
2171 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2172 if (!mysids)
2173 goto out_unlock;
2174
2175 ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2176 role = policydb.role_val_to_struct[i];
2177 usercon.role = i + 1;
2178 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2179 usercon.type = j + 1;
2180
2181 if (mls_setup_user_range(fromcon, user, &usercon))
2182 continue;
2183
2184 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2185 if (rc)
2186 goto out_unlock;
2187 if (mynel < maxnel) {
2188 mysids[mynel++] = sid;
2189 } else {
2190 rc = -ENOMEM;
2191 maxnel += SIDS_NEL;
2192 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2193 if (!mysids2)
2194 goto out_unlock;
2195 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2196 kfree(mysids);
2197 mysids = mysids2;
2198 mysids[mynel++] = sid;
2199 }
2200 }
2201 }
2202 rc = 0;
2203 out_unlock:
2204 read_unlock(&policy_rwlock);
2205 if (rc || !mynel) {
2206 kfree(mysids);
2207 goto out;
2208 }
2209
2210 rc = -ENOMEM;
2211 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2212 if (!mysids2) {
2213 kfree(mysids);
2214 goto out;
2215 }
2216 for (i = 0, j = 0; i < mynel; i++) {
2217 struct av_decision dummy_avd;
2218 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2219 SECCLASS_PROCESS, /* kernel value */
2220 PROCESS__TRANSITION, AVC_STRICT,
2221 &dummy_avd);
2222 if (!rc)
2223 mysids2[j++] = mysids[i];
2224 cond_resched();
2225 }
2226 rc = 0;
2227 kfree(mysids);
2228 *sids = mysids2;
2229 *nel = j;
2230 out:
2231 return rc;
2232 }
2233
2234 /**
2235 * security_genfs_sid - Obtain a SID for a file in a filesystem
2236 * @fstype: filesystem type
2237 * @path: path from root of mount
2238 * @sclass: file security class
2239 * @sid: SID for path
2240 *
2241 * Obtain a SID to use for a file in a filesystem that
2242 * cannot support xattr or use a fixed labeling behavior like
2243 * transition SIDs or task SIDs.
2244 */
2245 int security_genfs_sid(const char *fstype,
2246 char *path,
2247 u16 orig_sclass,
2248 u32 *sid)
2249 {
2250 int len;
2251 u16 sclass;
2252 struct genfs *genfs;
2253 struct ocontext *c;
2254 int rc, cmp = 0;
2255
2256 while (path[0] == '/' && path[1] == '/')
2257 path++;
2258
2259 read_lock(&policy_rwlock);
2260
2261 sclass = unmap_class(orig_sclass);
2262 *sid = SECINITSID_UNLABELED;
2263
2264 for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2265 cmp = strcmp(fstype, genfs->fstype);
2266 if (cmp <= 0)
2267 break;
2268 }
2269
2270 rc = -ENOENT;
2271 if (!genfs || cmp)
2272 goto out;
2273
2274 for (c = genfs->head; c; c = c->next) {
2275 len = strlen(c->u.name);
2276 if ((!c->v.sclass || sclass == c->v.sclass) &&
2277 (strncmp(c->u.name, path, len) == 0))
2278 break;
2279 }
2280
2281 rc = -ENOENT;
2282 if (!c)
2283 goto out;
2284
2285 if (!c->sid[0]) {
2286 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2287 if (rc)
2288 goto out;
2289 }
2290
2291 *sid = c->sid[0];
2292 rc = 0;
2293 out:
2294 read_unlock(&policy_rwlock);
2295 return rc;
2296 }
2297
2298 /**
2299 * security_fs_use - Determine how to handle labeling for a filesystem.
2300 * @fstype: filesystem type
2301 * @behavior: labeling behavior
2302 * @sid: SID for filesystem (superblock)
2303 */
2304 int security_fs_use(
2305 const char *fstype,
2306 unsigned int *behavior,
2307 u32 *sid)
2308 {
2309 int rc = 0;
2310 struct ocontext *c;
2311
2312 read_lock(&policy_rwlock);
2313
2314 c = policydb.ocontexts[OCON_FSUSE];
2315 while (c) {
2316 if (strcmp(fstype, c->u.name) == 0)
2317 break;
2318 c = c->next;
2319 }
2320
2321 if (c) {
2322 *behavior = c->v.behavior;
2323 if (!c->sid[0]) {
2324 rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2325 &c->sid[0]);
2326 if (rc)
2327 goto out;
2328 }
2329 *sid = c->sid[0];
2330 } else {
2331 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2332 if (rc) {
2333 *behavior = SECURITY_FS_USE_NONE;
2334 rc = 0;
2335 } else {
2336 *behavior = SECURITY_FS_USE_GENFS;
2337 }
2338 }
2339
2340 out:
2341 read_unlock(&policy_rwlock);
2342 return rc;
2343 }
2344
2345 int security_get_bools(int *len, char ***names, int **values)
2346 {
2347 int i, rc;
2348
2349 read_lock(&policy_rwlock);
2350 *names = NULL;
2351 *values = NULL;
2352
2353 rc = 0;
2354 *len = policydb.p_bools.nprim;
2355 if (!*len)
2356 goto out;
2357
2358 rc = -ENOMEM;
2359 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2360 if (!*names)
2361 goto err;
2362
2363 rc = -ENOMEM;
2364 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2365 if (!*values)
2366 goto err;
2367
2368 for (i = 0; i < *len; i++) {
2369 size_t name_len;
2370
2371 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2372 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2373
2374 rc = -ENOMEM;
2375 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2376 if (!(*names)[i])
2377 goto err;
2378
2379 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2380 (*names)[i][name_len - 1] = 0;
2381 }
2382 rc = 0;
2383 out:
2384 read_unlock(&policy_rwlock);
2385 return rc;
2386 err:
2387 if (*names) {
2388 for (i = 0; i < *len; i++)
2389 kfree((*names)[i]);
2390 }
2391 kfree(*values);
2392 goto out;
2393 }
2394
2395
2396 int security_set_bools(int len, int *values)
2397 {
2398 int i, rc;
2399 int lenp, seqno = 0;
2400 struct cond_node *cur;
2401
2402 write_lock_irq(&policy_rwlock);
2403
2404 rc = -EFAULT;
2405 lenp = policydb.p_bools.nprim;
2406 if (len != lenp)
2407 goto out;
2408
2409 for (i = 0; i < len; i++) {
2410 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2411 audit_log(current->audit_context, GFP_ATOMIC,
2412 AUDIT_MAC_CONFIG_CHANGE,
2413 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2414 sym_name(&policydb, SYM_BOOLS, i),
2415 !!values[i],
2416 policydb.bool_val_to_struct[i]->state,
2417 audit_get_loginuid(current),
2418 audit_get_sessionid(current));
2419 }
2420 if (values[i])
2421 policydb.bool_val_to_struct[i]->state = 1;
2422 else
2423 policydb.bool_val_to_struct[i]->state = 0;
2424 }
2425
2426 for (cur = policydb.cond_list; cur; cur = cur->next) {
2427 rc = evaluate_cond_node(&policydb, cur);
2428 if (rc)
2429 goto out;
2430 }
2431
2432 seqno = ++latest_granting;
2433 rc = 0;
2434 out:
2435 write_unlock_irq(&policy_rwlock);
2436 if (!rc) {
2437 avc_ss_reset(seqno);
2438 selnl_notify_policyload(seqno);
2439 selinux_status_update_policyload(seqno);
2440 selinux_xfrm_notify_policyload();
2441 }
2442 return rc;
2443 }
2444
2445 int security_get_bool_value(int bool)
2446 {
2447 int rc;
2448 int len;
2449
2450 read_lock(&policy_rwlock);
2451
2452 rc = -EFAULT;
2453 len = policydb.p_bools.nprim;
2454 if (bool >= len)
2455 goto out;
2456
2457 rc = policydb.bool_val_to_struct[bool]->state;
2458 out:
2459 read_unlock(&policy_rwlock);
2460 return rc;
2461 }
2462
2463 static int security_preserve_bools(struct policydb *p)
2464 {
2465 int rc, nbools = 0, *bvalues = NULL, i;
2466 char **bnames = NULL;
2467 struct cond_bool_datum *booldatum;
2468 struct cond_node *cur;
2469
2470 rc = security_get_bools(&nbools, &bnames, &bvalues);
2471 if (rc)
2472 goto out;
2473 for (i = 0; i < nbools; i++) {
2474 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2475 if (booldatum)
2476 booldatum->state = bvalues[i];
2477 }
2478 for (cur = p->cond_list; cur; cur = cur->next) {
2479 rc = evaluate_cond_node(p, cur);
2480 if (rc)
2481 goto out;
2482 }
2483
2484 out:
2485 if (bnames) {
2486 for (i = 0; i < nbools; i++)
2487 kfree(bnames[i]);
2488 }
2489 kfree(bnames);
2490 kfree(bvalues);
2491 return rc;
2492 }
2493
2494 /*
2495 * security_sid_mls_copy() - computes a new sid based on the given
2496 * sid and the mls portion of mls_sid.
2497 */
2498 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2499 {
2500 struct context *context1;
2501 struct context *context2;
2502 struct context newcon;
2503 char *s;
2504 u32 len;
2505 int rc;
2506
2507 rc = 0;
2508 if (!ss_initialized || !policydb.mls_enabled) {
2509 *new_sid = sid;
2510 goto out;
2511 }
2512
2513 context_init(&newcon);
2514
2515 read_lock(&policy_rwlock);
2516
2517 rc = -EINVAL;
2518 context1 = sidtab_search(&sidtab, sid);
2519 if (!context1) {
2520 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2521 __func__, sid);
2522 goto out_unlock;
2523 }
2524
2525 rc = -EINVAL;
2526 context2 = sidtab_search(&sidtab, mls_sid);
2527 if (!context2) {
2528 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2529 __func__, mls_sid);
2530 goto out_unlock;
2531 }
2532
2533 newcon.user = context1->user;
2534 newcon.role = context1->role;
2535 newcon.type = context1->type;
2536 rc = mls_context_cpy(&newcon, context2);
2537 if (rc)
2538 goto out_unlock;
2539
2540 /* Check the validity of the new context. */
2541 if (!policydb_context_isvalid(&policydb, &newcon)) {
2542 rc = convert_context_handle_invalid_context(&newcon);
2543 if (rc) {
2544 if (!context_struct_to_string(&newcon, &s, &len)) {
2545 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2546 "security_sid_mls_copy: invalid context %s", s);
2547 kfree(s);
2548 }
2549 goto out_unlock;
2550 }
2551 }
2552
2553 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2554 out_unlock:
2555 read_unlock(&policy_rwlock);
2556 context_destroy(&newcon);
2557 out:
2558 return rc;
2559 }
2560
2561 /**
2562 * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2563 * @nlbl_sid: NetLabel SID
2564 * @nlbl_type: NetLabel labeling protocol type
2565 * @xfrm_sid: XFRM SID
2566 *
2567 * Description:
2568 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2569 * resolved into a single SID it is returned via @peer_sid and the function
2570 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function
2571 * returns a negative value. A table summarizing the behavior is below:
2572 *
2573 * | function return | @sid
2574 * ------------------------------+-----------------+-----------------
2575 * no peer labels | 0 | SECSID_NULL
2576 * single peer label | 0 | <peer_label>
2577 * multiple, consistent labels | 0 | <peer_label>
2578 * multiple, inconsistent labels | -<errno> | SECSID_NULL
2579 *
2580 */
2581 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2582 u32 xfrm_sid,
2583 u32 *peer_sid)
2584 {
2585 int rc;
2586 struct context *nlbl_ctx;
2587 struct context *xfrm_ctx;
2588
2589 *peer_sid = SECSID_NULL;
2590
2591 /* handle the common (which also happens to be the set of easy) cases
2592 * right away, these two if statements catch everything involving a
2593 * single or absent peer SID/label */
2594 if (xfrm_sid == SECSID_NULL) {
2595 *peer_sid = nlbl_sid;
2596 return 0;
2597 }
2598 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2599 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2600 * is present */
2601 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2602 *peer_sid = xfrm_sid;
2603 return 0;
2604 }
2605
2606 /* we don't need to check ss_initialized here since the only way both
2607 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2608 * security server was initialized and ss_initialized was true */
2609 if (!policydb.mls_enabled)
2610 return 0;
2611
2612 read_lock(&policy_rwlock);
2613
2614 rc = -EINVAL;
2615 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2616 if (!nlbl_ctx) {
2617 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2618 __func__, nlbl_sid);
2619 goto out;
2620 }
2621 rc = -EINVAL;
2622 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2623 if (!xfrm_ctx) {
2624 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n",
2625 __func__, xfrm_sid);
2626 goto out;
2627 }
2628 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2629 if (rc)
2630 goto out;
2631
2632 /* at present NetLabel SIDs/labels really only carry MLS
2633 * information so if the MLS portion of the NetLabel SID
2634 * matches the MLS portion of the labeled XFRM SID/label
2635 * then pass along the XFRM SID as it is the most
2636 * expressive */
2637 *peer_sid = xfrm_sid;
2638 out:
2639 read_unlock(&policy_rwlock);
2640 return rc;
2641 }
2642
2643 static int get_classes_callback(void *k, void *d, void *args)
2644 {
2645 struct class_datum *datum = d;
2646 char *name = k, **classes = args;
2647 int value = datum->value - 1;
2648
2649 classes[value] = kstrdup(name, GFP_ATOMIC);
2650 if (!classes[value])
2651 return -ENOMEM;
2652
2653 return 0;
2654 }
2655
2656 int security_get_classes(char ***classes, int *nclasses)
2657 {
2658 int rc;
2659
2660 read_lock(&policy_rwlock);
2661
2662 rc = -ENOMEM;
2663 *nclasses = policydb.p_classes.nprim;
2664 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2665 if (!*classes)
2666 goto out;
2667
2668 rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2669 *classes);
2670 if (rc) {
2671 int i;
2672 for (i = 0; i < *nclasses; i++)
2673 kfree((*classes)[i]);
2674 kfree(*classes);
2675 }
2676
2677 out:
2678 read_unlock(&policy_rwlock);
2679 return rc;
2680 }
2681
2682 static int get_permissions_callback(void *k, void *d, void *args)
2683 {
2684 struct perm_datum *datum = d;
2685 char *name = k, **perms = args;
2686 int value = datum->value - 1;
2687
2688 perms[value] = kstrdup(name, GFP_ATOMIC);
2689 if (!perms[value])
2690 return -ENOMEM;
2691
2692 return 0;
2693 }
2694
2695 int security_get_permissions(char *class, char ***perms, int *nperms)
2696 {
2697 int rc, i;
2698 struct class_datum *match;
2699
2700 read_lock(&policy_rwlock);
2701
2702 rc = -EINVAL;
2703 match = hashtab_search(policydb.p_classes.table, class);
2704 if (!match) {
2705 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n",
2706 __func__, class);
2707 goto out;
2708 }
2709
2710 rc = -ENOMEM;
2711 *nperms = match->permissions.nprim;
2712 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2713 if (!*perms)
2714 goto out;
2715
2716 if (match->comdatum) {
2717 rc = hashtab_map(match->comdatum->permissions.table,
2718 get_permissions_callback, *perms);
2719 if (rc)
2720 goto err;
2721 }
2722
2723 rc = hashtab_map(match->permissions.table, get_permissions_callback,
2724 *perms);
2725 if (rc)
2726 goto err;
2727
2728 out:
2729 read_unlock(&policy_rwlock);
2730 return rc;
2731
2732 err:
2733 read_unlock(&policy_rwlock);
2734 for (i = 0; i < *nperms; i++)
2735 kfree((*perms)[i]);
2736 kfree(*perms);
2737 return rc;
2738 }
2739
2740 int security_get_reject_unknown(void)
2741 {
2742 return policydb.reject_unknown;
2743 }
2744
2745 int security_get_allow_unknown(void)
2746 {
2747 return policydb.allow_unknown;
2748 }
2749
2750 /**
2751 * security_policycap_supported - Check for a specific policy capability
2752 * @req_cap: capability
2753 *
2754 * Description:
2755 * This function queries the currently loaded policy to see if it supports the
2756 * capability specified by @req_cap. Returns true (1) if the capability is
2757 * supported, false (0) if it isn't supported.
2758 *
2759 */
2760 int security_policycap_supported(unsigned int req_cap)
2761 {
2762 int rc;
2763
2764 read_lock(&policy_rwlock);
2765 rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2766 read_unlock(&policy_rwlock);
2767
2768 return rc;
2769 }
2770
2771 struct selinux_audit_rule {
2772 u32 au_seqno;
2773 struct context au_ctxt;
2774 };
2775
2776 void selinux_audit_rule_free(void *vrule)
2777 {
2778 struct selinux_audit_rule *rule = vrule;
2779
2780 if (rule) {
2781 context_destroy(&rule->au_ctxt);
2782 kfree(rule);
2783 }
2784 }
2785
2786 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2787 {
2788 struct selinux_audit_rule *tmprule;
2789 struct role_datum *roledatum;
2790 struct type_datum *typedatum;
2791 struct user_datum *userdatum;
2792 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2793 int rc = 0;
2794
2795 *rule = NULL;
2796
2797 if (!ss_initialized)
2798 return -EOPNOTSUPP;
2799
2800 switch (field) {
2801 case AUDIT_SUBJ_USER:
2802 case AUDIT_SUBJ_ROLE:
2803 case AUDIT_SUBJ_TYPE:
2804 case AUDIT_OBJ_USER:
2805 case AUDIT_OBJ_ROLE:
2806 case AUDIT_OBJ_TYPE:
2807 /* only 'equals' and 'not equals' fit user, role, and type */
2808 if (op != Audit_equal && op != Audit_not_equal)
2809 return -EINVAL;
2810 break;
2811 case AUDIT_SUBJ_SEN:
2812 case AUDIT_SUBJ_CLR:
2813 case AUDIT_OBJ_LEV_LOW:
2814 case AUDIT_OBJ_LEV_HIGH:
2815 /* we do not allow a range, indicated by the presence of '-' */
2816 if (strchr(rulestr, '-'))
2817 return -EINVAL;
2818 break;
2819 default:
2820 /* only the above fields are valid */
2821 return -EINVAL;
2822 }
2823
2824 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2825 if (!tmprule)
2826 return -ENOMEM;
2827
2828 context_init(&tmprule->au_ctxt);
2829
2830 read_lock(&policy_rwlock);
2831
2832 tmprule->au_seqno = latest_granting;
2833
2834 switch (field) {
2835 case AUDIT_SUBJ_USER:
2836 case AUDIT_OBJ_USER:
2837 rc = -EINVAL;
2838 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2839 if (!userdatum)
2840 goto out;
2841 tmprule->au_ctxt.user = userdatum->value;
2842 break;
2843 case AUDIT_SUBJ_ROLE:
2844 case AUDIT_OBJ_ROLE:
2845 rc = -EINVAL;
2846 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2847 if (!roledatum)
2848 goto out;
2849 tmprule->au_ctxt.role = roledatum->value;
2850 break;
2851 case AUDIT_SUBJ_TYPE:
2852 case AUDIT_OBJ_TYPE:
2853 rc = -EINVAL;
2854 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2855 if (!typedatum)
2856 goto out;
2857 tmprule->au_ctxt.type = typedatum->value;
2858 break;
2859 case AUDIT_SUBJ_SEN:
2860 case AUDIT_SUBJ_CLR:
2861 case AUDIT_OBJ_LEV_LOW:
2862 case AUDIT_OBJ_LEV_HIGH:
2863 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2864 if (rc)
2865 goto out;
2866 break;
2867 }
2868 rc = 0;
2869 out:
2870 read_unlock(&policy_rwlock);
2871
2872 if (rc) {
2873 selinux_audit_rule_free(tmprule);
2874 tmprule = NULL;
2875 }
2876
2877 *rule = tmprule;
2878
2879 return rc;
2880 }
2881
2882 /* Check to see if the rule contains any selinux fields */
2883 int selinux_audit_rule_known(struct audit_krule *rule)
2884 {
2885 int i;
2886
2887 for (i = 0; i < rule->field_count; i++) {
2888 struct audit_field *f = &rule->fields[i];
2889 switch (f->type) {
2890 case AUDIT_SUBJ_USER:
2891 case AUDIT_SUBJ_ROLE:
2892 case AUDIT_SUBJ_TYPE:
2893 case AUDIT_SUBJ_SEN:
2894 case AUDIT_SUBJ_CLR:
2895 case AUDIT_OBJ_USER:
2896 case AUDIT_OBJ_ROLE:
2897 case AUDIT_OBJ_TYPE:
2898 case AUDIT_OBJ_LEV_LOW:
2899 case AUDIT_OBJ_LEV_HIGH:
2900 return 1;
2901 }
2902 }
2903
2904 return 0;
2905 }
2906
2907 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2908 struct audit_context *actx)
2909 {
2910 struct context *ctxt;
2911 struct mls_level *level;
2912 struct selinux_audit_rule *rule = vrule;
2913 int match = 0;
2914
2915 if (!rule) {
2916 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2917 "selinux_audit_rule_match: missing rule\n");
2918 return -ENOENT;
2919 }
2920
2921 read_lock(&policy_rwlock);
2922
2923 if (rule->au_seqno < latest_granting) {
2924 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2925 "selinux_audit_rule_match: stale rule\n");
2926 match = -ESTALE;
2927 goto out;
2928 }
2929
2930 ctxt = sidtab_search(&sidtab, sid);
2931 if (!ctxt) {
2932 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2933 "selinux_audit_rule_match: unrecognized SID %d\n",
2934 sid);
2935 match = -ENOENT;
2936 goto out;
2937 }
2938
2939 /* a field/op pair that is not caught here will simply fall through
2940 without a match */
2941 switch (field) {
2942 case AUDIT_SUBJ_USER:
2943 case AUDIT_OBJ_USER:
2944 switch (op) {
2945 case Audit_equal:
2946 match = (ctxt->user == rule->au_ctxt.user);
2947 break;
2948 case Audit_not_equal:
2949 match = (ctxt->user != rule->au_ctxt.user);
2950 break;
2951 }
2952 break;
2953 case AUDIT_SUBJ_ROLE:
2954 case AUDIT_OBJ_ROLE:
2955 switch (op) {
2956 case Audit_equal:
2957 match = (ctxt->role == rule->au_ctxt.role);
2958 break;
2959 case Audit_not_equal:
2960 match = (ctxt->role != rule->au_ctxt.role);
2961 break;
2962 }
2963 break;
2964 case AUDIT_SUBJ_TYPE:
2965 case AUDIT_OBJ_TYPE:
2966 switch (op) {
2967 case Audit_equal:
2968 match = (ctxt->type == rule->au_ctxt.type);
2969 break;
2970 case Audit_not_equal:
2971 match = (ctxt->type != rule->au_ctxt.type);
2972 break;
2973 }
2974 break;
2975 case AUDIT_SUBJ_SEN:
2976 case AUDIT_SUBJ_CLR:
2977 case AUDIT_OBJ_LEV_LOW:
2978 case AUDIT_OBJ_LEV_HIGH:
2979 level = ((field == AUDIT_SUBJ_SEN ||
2980 field == AUDIT_OBJ_LEV_LOW) ?
2981 &ctxt->range.level[0] : &ctxt->range.level[1]);
2982 switch (op) {
2983 case Audit_equal:
2984 match = mls_level_eq(&rule->au_ctxt.range.level[0],
2985 level);
2986 break;
2987 case Audit_not_equal:
2988 match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2989 level);
2990 break;
2991 case Audit_lt:
2992 match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2993 level) &&
2994 !mls_level_eq(&rule->au_ctxt.range.level[0],
2995 level));
2996 break;
2997 case Audit_le:
2998 match = mls_level_dom(&rule->au_ctxt.range.level[0],
2999 level);
3000 break;
3001 case Audit_gt:
3002 match = (mls_level_dom(level,
3003 &rule->au_ctxt.range.level[0]) &&
3004 !mls_level_eq(level,
3005 &rule->au_ctxt.range.level[0]));
3006 break;
3007 case Audit_ge:
3008 match = mls_level_dom(level,
3009 &rule->au_ctxt.range.level[0]);
3010 break;
3011 }
3012 }
3013
3014 out:
3015 read_unlock(&policy_rwlock);
3016 return match;
3017 }
3018
3019 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3020
3021 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3022 u16 class, u32 perms, u32 *retained)
3023 {
3024 int err = 0;
3025
3026 if (event == AVC_CALLBACK_RESET && aurule_callback)
3027 err = aurule_callback();
3028 return err;
3029 }
3030
3031 static int __init aurule_init(void)
3032 {
3033 int err;
3034
3035 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3036 SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3037 if (err)
3038 panic("avc_add_callback() failed, error %d\n", err);
3039
3040 return err;
3041 }
3042 __initcall(aurule_init);
3043
3044 #ifdef CONFIG_NETLABEL
3045 /**
3046 * security_netlbl_cache_add - Add an entry to the NetLabel cache
3047 * @secattr: the NetLabel packet security attributes
3048 * @sid: the SELinux SID
3049 *
3050 * Description:
3051 * Attempt to cache the context in @ctx, which was derived from the packet in
3052 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has
3053 * already been initialized.
3054 *
3055 */
3056 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3057 u32 sid)
3058 {
3059 u32 *sid_cache;
3060
3061 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3062 if (sid_cache == NULL)
3063 return;
3064 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3065 if (secattr->cache == NULL) {
3066 kfree(sid_cache);
3067 return;
3068 }
3069
3070 *sid_cache = sid;
3071 secattr->cache->free = kfree;
3072 secattr->cache->data = sid_cache;
3073 secattr->flags |= NETLBL_SECATTR_CACHE;
3074 }
3075
3076 /**
3077 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3078 * @secattr: the NetLabel packet security attributes
3079 * @sid: the SELinux SID
3080 *
3081 * Description:
3082 * Convert the given NetLabel security attributes in @secattr into a
3083 * SELinux SID. If the @secattr field does not contain a full SELinux
3084 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the
3085 * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3086 * allow the @secattr to be used by NetLabel to cache the secattr to SID
3087 * conversion for future lookups. Returns zero on success, negative values on
3088 * failure.
3089 *
3090 */
3091 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3092 u32 *sid)
3093 {
3094 int rc;
3095 struct context *ctx;
3096 struct context ctx_new;
3097
3098 if (!ss_initialized) {
3099 *sid = SECSID_NULL;
3100 return 0;
3101 }
3102
3103 read_lock(&policy_rwlock);
3104
3105 if (secattr->flags & NETLBL_SECATTR_CACHE)
3106 *sid = *(u32 *)secattr->cache->data;
3107 else if (secattr->flags & NETLBL_SECATTR_SECID)
3108 *sid = secattr->attr.secid;
3109 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3110 rc = -EIDRM;
3111 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3112 if (ctx == NULL)
3113 goto out;
3114
3115 context_init(&ctx_new);
3116 ctx_new.user = ctx->user;
3117 ctx_new.role = ctx->role;
3118 ctx_new.type = ctx->type;
3119 mls_import_netlbl_lvl(&ctx_new, secattr);
3120 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3121 rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3122 secattr->attr.mls.cat);
3123 if (rc)
3124 goto out;
3125 memcpy(&ctx_new.range.level[1].cat,
3126 &ctx_new.range.level[0].cat,
3127 sizeof(ctx_new.range.level[0].cat));
3128 }
3129 rc = -EIDRM;
3130 if (!mls_context_isvalid(&policydb, &ctx_new))
3131 goto out_free;
3132
3133 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3134 if (rc)
3135 goto out_free;
3136
3137 security_netlbl_cache_add(secattr, *sid);
3138
3139 ebitmap_destroy(&ctx_new.range.level[0].cat);
3140 } else
3141 *sid = SECSID_NULL;
3142
3143 read_unlock(&policy_rwlock);
3144 return 0;
3145 out_free:
3146 ebitmap_destroy(&ctx_new.range.level[0].cat);
3147 out:
3148 read_unlock(&policy_rwlock);
3149 return rc;
3150 }
3151
3152 /**
3153 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3154 * @sid: the SELinux SID
3155 * @secattr: the NetLabel packet security attributes
3156 *
3157 * Description:
3158 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3159 * Returns zero on success, negative values on failure.
3160 *
3161 */
3162 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3163 {
3164 int rc;
3165 struct context *ctx;
3166
3167 if (!ss_initialized)
3168 return 0;
3169
3170 read_lock(&policy_rwlock);
3171
3172 rc = -ENOENT;
3173 ctx = sidtab_search(&sidtab, sid);
3174 if (ctx == NULL)
3175 goto out;
3176
3177 rc = -ENOMEM;
3178 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3179 GFP_ATOMIC);
3180 if (secattr->domain == NULL)
3181 goto out;
3182
3183 secattr->attr.secid = sid;
3184 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3185 mls_export_netlbl_lvl(ctx, secattr);
3186 rc = mls_export_netlbl_cat(ctx, secattr);
3187 out:
3188 read_unlock(&policy_rwlock);
3189 return rc;
3190 }
3191 #endif /* CONFIG_NETLABEL */
3192
3193 /**
3194 * security_read_policy - read the policy.
3195 * @data: binary policy data
3196 * @len: length of data in bytes
3197 *
3198 */
3199 int security_read_policy(void **data, size_t *len)
3200 {
3201 int rc;
3202 struct policy_file fp;
3203
3204 if (!ss_initialized)
3205 return -EINVAL;
3206
3207 *len = security_policydb_len();
3208
3209 *data = vmalloc_user(*len);
3210 if (!*data)
3211 return -ENOMEM;
3212
3213 fp.data = *data;
3214 fp.len = *len;
3215
3216 read_lock(&policy_rwlock);
3217 rc = policydb_write(&policydb, &fp);
3218 read_unlock(&policy_rwlock);
3219
3220 if (rc)
3221 return rc;
3222
3223 *len = (unsigned long)fp.data - (unsigned long)*data;
3224 return 0;
3225
3226 }
Linux with added FPC-III support