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