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TOMOYO Linux Cross Reference
Linux/security/selinux/ss/services.c

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  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         /* An empty security context is never valid. */
1233         if (!scontext_len)
1234                 return -EINVAL;
1235 
1236         if (!ss_initialized) {
1237                 int i;
1238 
1239                 for (i = 1; i < SECINITSID_NUM; i++) {
1240                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1241                                 *sid = i;
1242                                 return 0;
1243                         }
1244                 }
1245                 *sid = SECINITSID_KERNEL;
1246                 return 0;
1247         }
1248         *sid = SECSID_NULL;
1249 
1250         /* Copy the string so that we can modify the copy as we parse it. */
1251         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1252         if (!scontext2)
1253                 return -ENOMEM;
1254         memcpy(scontext2, scontext, scontext_len);
1255         scontext2[scontext_len] = 0;
1256 
1257         if (force) {
1258                 /* Save another copy for storing in uninterpreted form */
1259                 rc = -ENOMEM;
1260                 str = kstrdup(scontext2, gfp_flags);
1261                 if (!str)
1262                         goto out;
1263         }
1264 
1265         read_lock(&policy_rwlock);
1266         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1267                                       scontext_len, &context, def_sid);
1268         if (rc == -EINVAL && force) {
1269                 context.str = str;
1270                 context.len = scontext_len;
1271                 str = NULL;
1272         } else if (rc)
1273                 goto out_unlock;
1274         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1275         context_destroy(&context);
1276 out_unlock:
1277         read_unlock(&policy_rwlock);
1278 out:
1279         kfree(scontext2);
1280         kfree(str);
1281         return rc;
1282 }
1283 
1284 /**
1285  * security_context_to_sid - Obtain a SID for a given security context.
1286  * @scontext: security context
1287  * @scontext_len: length in bytes
1288  * @sid: security identifier, SID
1289  *
1290  * Obtains a SID associated with the security context that
1291  * has the string representation specified by @scontext.
1292  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1293  * memory is available, or 0 on success.
1294  */
1295 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1296 {
1297         return security_context_to_sid_core(scontext, scontext_len,
1298                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1299 }
1300 
1301 /**
1302  * security_context_to_sid_default - Obtain a SID for a given security context,
1303  * falling back to specified default if needed.
1304  *
1305  * @scontext: security context
1306  * @scontext_len: length in bytes
1307  * @sid: security identifier, SID
1308  * @def_sid: default SID to assign on error
1309  *
1310  * Obtains a SID associated with the security context that
1311  * has the string representation specified by @scontext.
1312  * The default SID is passed to the MLS layer to be used to allow
1313  * kernel labeling of the MLS field if the MLS field is not present
1314  * (for upgrading to MLS without full relabel).
1315  * Implicitly forces adding of the context even if it cannot be mapped yet.
1316  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1317  * memory is available, or 0 on success.
1318  */
1319 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1320                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1321 {
1322         return security_context_to_sid_core(scontext, scontext_len,
1323                                             sid, def_sid, gfp_flags, 1);
1324 }
1325 
1326 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1327                                   u32 *sid)
1328 {
1329         return security_context_to_sid_core(scontext, scontext_len,
1330                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1331 }
1332 
1333 static int compute_sid_handle_invalid_context(
1334         struct context *scontext,
1335         struct context *tcontext,
1336         u16 tclass,
1337         struct context *newcontext)
1338 {
1339         char *s = NULL, *t = NULL, *n = NULL;
1340         u32 slen, tlen, nlen;
1341 
1342         if (context_struct_to_string(scontext, &s, &slen))
1343                 goto out;
1344         if (context_struct_to_string(tcontext, &t, &tlen))
1345                 goto out;
1346         if (context_struct_to_string(newcontext, &n, &nlen))
1347                 goto out;
1348         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1349                   "security_compute_sid:  invalid context %s"
1350                   " for scontext=%s"
1351                   " tcontext=%s"
1352                   " tclass=%s",
1353                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1354 out:
1355         kfree(s);
1356         kfree(t);
1357         kfree(n);
1358         if (!selinux_enforcing)
1359                 return 0;
1360         return -EACCES;
1361 }
1362 
1363 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1364                                   u32 stype, u32 ttype, u16 tclass,
1365                                   const char *objname)
1366 {
1367         struct filename_trans ft;
1368         struct filename_trans_datum *otype;
1369 
1370         /*
1371          * Most filename trans rules are going to live in specific directories
1372          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1373          * if the ttype does not contain any rules.
1374          */
1375         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1376                 return;
1377 
1378         ft.stype = stype;
1379         ft.ttype = ttype;
1380         ft.tclass = tclass;
1381         ft.name = objname;
1382 
1383         otype = hashtab_search(p->filename_trans, &ft);
1384         if (otype)
1385                 newcontext->type = otype->otype;
1386 }
1387 
1388 static int security_compute_sid(u32 ssid,
1389                                 u32 tsid,
1390                                 u16 orig_tclass,
1391                                 u32 specified,
1392                                 const char *objname,
1393                                 u32 *out_sid,
1394                                 bool kern)
1395 {
1396         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1397         struct role_trans *roletr = NULL;
1398         struct avtab_key avkey;
1399         struct avtab_datum *avdatum;
1400         struct avtab_node *node;
1401         u16 tclass;
1402         int rc = 0;
1403         bool sock;
1404 
1405         if (!ss_initialized) {
1406                 switch (orig_tclass) {
1407                 case SECCLASS_PROCESS: /* kernel value */
1408                         *out_sid = ssid;
1409                         break;
1410                 default:
1411                         *out_sid = tsid;
1412                         break;
1413                 }
1414                 goto out;
1415         }
1416 
1417         context_init(&newcontext);
1418 
1419         read_lock(&policy_rwlock);
1420 
1421         if (kern) {
1422                 tclass = unmap_class(orig_tclass);
1423                 sock = security_is_socket_class(orig_tclass);
1424         } else {
1425                 tclass = orig_tclass;
1426                 sock = security_is_socket_class(map_class(tclass));
1427         }
1428 
1429         scontext = sidtab_search(&sidtab, ssid);
1430         if (!scontext) {
1431                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1432                        __func__, ssid);
1433                 rc = -EINVAL;
1434                 goto out_unlock;
1435         }
1436         tcontext = sidtab_search(&sidtab, tsid);
1437         if (!tcontext) {
1438                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1439                        __func__, tsid);
1440                 rc = -EINVAL;
1441                 goto out_unlock;
1442         }
1443 
1444         /* Set the user identity. */
1445         switch (specified) {
1446         case AVTAB_TRANSITION:
1447         case AVTAB_CHANGE:
1448                 /* Use the process user identity. */
1449                 newcontext.user = scontext->user;
1450                 break;
1451         case AVTAB_MEMBER:
1452                 /* Use the related object owner. */
1453                 newcontext.user = tcontext->user;
1454                 break;
1455         }
1456 
1457         /* Set the role and type to default values. */
1458         if ((tclass == policydb.process_class) || (sock == true)) {
1459                 /* Use the current role and type of process. */
1460                 newcontext.role = scontext->role;
1461                 newcontext.type = scontext->type;
1462         } else {
1463                 /* Use the well-defined object role. */
1464                 newcontext.role = OBJECT_R_VAL;
1465                 /* Use the type of the related object. */
1466                 newcontext.type = tcontext->type;
1467         }
1468 
1469         /* Look for a type transition/member/change rule. */
1470         avkey.source_type = scontext->type;
1471         avkey.target_type = tcontext->type;
1472         avkey.target_class = tclass;
1473         avkey.specified = specified;
1474         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1475 
1476         /* If no permanent rule, also check for enabled conditional rules */
1477         if (!avdatum) {
1478                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1479                 for (; node; node = avtab_search_node_next(node, specified)) {
1480                         if (node->key.specified & AVTAB_ENABLED) {
1481                                 avdatum = &node->datum;
1482                                 break;
1483                         }
1484                 }
1485         }
1486 
1487         if (avdatum) {
1488                 /* Use the type from the type transition/member/change rule. */
1489                 newcontext.type = avdatum->data;
1490         }
1491 
1492         /* if we have a objname this is a file trans check so check those rules */
1493         if (objname)
1494                 filename_compute_type(&policydb, &newcontext, scontext->type,
1495                                       tcontext->type, tclass, objname);
1496 
1497         /* Check for class-specific changes. */
1498         if (specified & AVTAB_TRANSITION) {
1499                 /* Look for a role transition rule. */
1500                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1501                         if ((roletr->role == scontext->role) &&
1502                             (roletr->type == tcontext->type) &&
1503                             (roletr->tclass == tclass)) {
1504                                 /* Use the role transition rule. */
1505                                 newcontext.role = roletr->new_role;
1506                                 break;
1507                         }
1508                 }
1509         }
1510 
1511         /* Set the MLS attributes.
1512            This is done last because it may allocate memory. */
1513         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1514                              &newcontext, sock);
1515         if (rc)
1516                 goto out_unlock;
1517 
1518         /* Check the validity of the context. */
1519         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1520                 rc = compute_sid_handle_invalid_context(scontext,
1521                                                         tcontext,
1522                                                         tclass,
1523                                                         &newcontext);
1524                 if (rc)
1525                         goto out_unlock;
1526         }
1527         /* Obtain the sid for the context. */
1528         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1529 out_unlock:
1530         read_unlock(&policy_rwlock);
1531         context_destroy(&newcontext);
1532 out:
1533         return rc;
1534 }
1535 
1536 /**
1537  * security_transition_sid - Compute the SID for a new subject/object.
1538  * @ssid: source security identifier
1539  * @tsid: target security identifier
1540  * @tclass: target security class
1541  * @out_sid: security identifier for new subject/object
1542  *
1543  * Compute a SID to use for labeling a new subject or object in the
1544  * class @tclass based on a SID pair (@ssid, @tsid).
1545  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1546  * if insufficient memory is available, or %0 if the new SID was
1547  * computed successfully.
1548  */
1549 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1550                             const struct qstr *qstr, u32 *out_sid)
1551 {
1552         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1553                                     qstr ? qstr->name : NULL, out_sid, true);
1554 }
1555 
1556 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1557                                  const char *objname, u32 *out_sid)
1558 {
1559         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1560                                     objname, out_sid, false);
1561 }
1562 
1563 /**
1564  * security_member_sid - Compute the SID for member selection.
1565  * @ssid: source security identifier
1566  * @tsid: target security identifier
1567  * @tclass: target security class
1568  * @out_sid: security identifier for selected member
1569  *
1570  * Compute a SID to use when selecting a member of a polyinstantiated
1571  * object of class @tclass based on a SID pair (@ssid, @tsid).
1572  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1573  * if insufficient memory is available, or %0 if the SID was
1574  * computed successfully.
1575  */
1576 int security_member_sid(u32 ssid,
1577                         u32 tsid,
1578                         u16 tclass,
1579                         u32 *out_sid)
1580 {
1581         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1582                                     out_sid, false);
1583 }
1584 
1585 /**
1586  * security_change_sid - Compute the SID for object relabeling.
1587  * @ssid: source security identifier
1588  * @tsid: target security identifier
1589  * @tclass: target security class
1590  * @out_sid: security identifier for selected member
1591  *
1592  * Compute a SID to use for relabeling an object of class @tclass
1593  * based on a SID pair (@ssid, @tsid).
1594  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1595  * if insufficient memory is available, or %0 if the SID was
1596  * computed successfully.
1597  */
1598 int security_change_sid(u32 ssid,
1599                         u32 tsid,
1600                         u16 tclass,
1601                         u32 *out_sid)
1602 {
1603         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1604                                     out_sid, false);
1605 }
1606 
1607 /* Clone the SID into the new SID table. */
1608 static int clone_sid(u32 sid,
1609                      struct context *context,
1610                      void *arg)
1611 {
1612         struct sidtab *s = arg;
1613 
1614         if (sid > SECINITSID_NUM)
1615                 return sidtab_insert(s, sid, context);
1616         else
1617                 return 0;
1618 }
1619 
1620 static inline int convert_context_handle_invalid_context(struct context *context)
1621 {
1622         char *s;
1623         u32 len;
1624 
1625         if (selinux_enforcing)
1626                 return -EINVAL;
1627 
1628         if (!context_struct_to_string(context, &s, &len)) {
1629                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1630                 kfree(s);
1631         }
1632         return 0;
1633 }
1634 
1635 struct convert_context_args {
1636         struct policydb *oldp;
1637         struct policydb *newp;
1638 };
1639 
1640 /*
1641  * Convert the values in the security context
1642  * structure `c' from the values specified
1643  * in the policy `p->oldp' to the values specified
1644  * in the policy `p->newp'.  Verify that the
1645  * context is valid under the new policy.
1646  */
1647 static int convert_context(u32 key,
1648                            struct context *c,
1649                            void *p)
1650 {
1651         struct convert_context_args *args;
1652         struct context oldc;
1653         struct ocontext *oc;
1654         struct mls_range *range;
1655         struct role_datum *role;
1656         struct type_datum *typdatum;
1657         struct user_datum *usrdatum;
1658         char *s;
1659         u32 len;
1660         int rc = 0;
1661 
1662         if (key <= SECINITSID_NUM)
1663                 goto out;
1664 
1665         args = p;
1666 
1667         if (c->str) {
1668                 struct context ctx;
1669 
1670                 rc = -ENOMEM;
1671                 s = kstrdup(c->str, GFP_KERNEL);
1672                 if (!s)
1673                         goto out;
1674 
1675                 rc = string_to_context_struct(args->newp, NULL, s,
1676                                               c->len, &ctx, SECSID_NULL);
1677                 kfree(s);
1678                 if (!rc) {
1679                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1680                                c->str);
1681                         /* Replace string with mapped representation. */
1682                         kfree(c->str);
1683                         memcpy(c, &ctx, sizeof(*c));
1684                         goto out;
1685                 } else if (rc == -EINVAL) {
1686                         /* Retain string representation for later mapping. */
1687                         rc = 0;
1688                         goto out;
1689                 } else {
1690                         /* Other error condition, e.g. ENOMEM. */
1691                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1692                                c->str, -rc);
1693                         goto out;
1694                 }
1695         }
1696 
1697         rc = context_cpy(&oldc, c);
1698         if (rc)
1699                 goto out;
1700 
1701         /* Convert the user. */
1702         rc = -EINVAL;
1703         usrdatum = hashtab_search(args->newp->p_users.table,
1704                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1705         if (!usrdatum)
1706                 goto bad;
1707         c->user = usrdatum->value;
1708 
1709         /* Convert the role. */
1710         rc = -EINVAL;
1711         role = hashtab_search(args->newp->p_roles.table,
1712                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1713         if (!role)
1714                 goto bad;
1715         c->role = role->value;
1716 
1717         /* Convert the type. */
1718         rc = -EINVAL;
1719         typdatum = hashtab_search(args->newp->p_types.table,
1720                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1721         if (!typdatum)
1722                 goto bad;
1723         c->type = typdatum->value;
1724 
1725         /* Convert the MLS fields if dealing with MLS policies */
1726         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1727                 rc = mls_convert_context(args->oldp, args->newp, c);
1728                 if (rc)
1729                         goto bad;
1730         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1731                 /*
1732                  * Switching between MLS and non-MLS policy:
1733                  * free any storage used by the MLS fields in the
1734                  * context for all existing entries in the sidtab.
1735                  */
1736                 mls_context_destroy(c);
1737         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1738                 /*
1739                  * Switching between non-MLS and MLS policy:
1740                  * ensure that the MLS fields of the context for all
1741                  * existing entries in the sidtab are filled in with a
1742                  * suitable default value, likely taken from one of the
1743                  * initial SIDs.
1744                  */
1745                 oc = args->newp->ocontexts[OCON_ISID];
1746                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1747                         oc = oc->next;
1748                 rc = -EINVAL;
1749                 if (!oc) {
1750                         printk(KERN_ERR "SELinux:  unable to look up"
1751                                 " the initial SIDs list\n");
1752                         goto bad;
1753                 }
1754                 range = &oc->context[0].range;
1755                 rc = mls_range_set(c, range);
1756                 if (rc)
1757                         goto bad;
1758         }
1759 
1760         /* Check the validity of the new context. */
1761         if (!policydb_context_isvalid(args->newp, c)) {
1762                 rc = convert_context_handle_invalid_context(&oldc);
1763                 if (rc)
1764                         goto bad;
1765         }
1766 
1767         context_destroy(&oldc);
1768 
1769         rc = 0;
1770 out:
1771         return rc;
1772 bad:
1773         /* Map old representation to string and save it. */
1774         rc = context_struct_to_string(&oldc, &s, &len);
1775         if (rc)
1776                 return rc;
1777         context_destroy(&oldc);
1778         context_destroy(c);
1779         c->str = s;
1780         c->len = len;
1781         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1782                c->str);
1783         rc = 0;
1784         goto out;
1785 }
1786 
1787 static void security_load_policycaps(void)
1788 {
1789         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1790                                                   POLICYDB_CAPABILITY_NETPEER);
1791         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1792                                                   POLICYDB_CAPABILITY_OPENPERM);
1793 }
1794 
1795 static int security_preserve_bools(struct policydb *p);
1796 
1797 /**
1798  * security_load_policy - Load a security policy configuration.
1799  * @data: binary policy data
1800  * @len: length of data in bytes
1801  *
1802  * Load a new set of security policy configuration data,
1803  * validate it and convert the SID table as necessary.
1804  * This function will flush the access vector cache after
1805  * loading the new policy.
1806  */
1807 int security_load_policy(void *data, size_t len)
1808 {
1809         struct policydb oldpolicydb, newpolicydb;
1810         struct sidtab oldsidtab, newsidtab;
1811         struct selinux_mapping *oldmap, *map = NULL;
1812         struct convert_context_args args;
1813         u32 seqno;
1814         u16 map_size;
1815         int rc = 0;
1816         struct policy_file file = { data, len }, *fp = &file;
1817 
1818         if (!ss_initialized) {
1819                 avtab_cache_init();
1820                 rc = policydb_read(&policydb, fp);
1821                 if (rc) {
1822                         avtab_cache_destroy();
1823                         return rc;
1824                 }
1825 
1826                 policydb.len = len;
1827                 rc = selinux_set_mapping(&policydb, secclass_map,
1828                                          &current_mapping,
1829                                          &current_mapping_size);
1830                 if (rc) {
1831                         policydb_destroy(&policydb);
1832                         avtab_cache_destroy();
1833                         return rc;
1834                 }
1835 
1836                 rc = policydb_load_isids(&policydb, &sidtab);
1837                 if (rc) {
1838                         policydb_destroy(&policydb);
1839                         avtab_cache_destroy();
1840                         return rc;
1841                 }
1842 
1843                 security_load_policycaps();
1844                 ss_initialized = 1;
1845                 seqno = ++latest_granting;
1846                 selinux_complete_init();
1847                 avc_ss_reset(seqno);
1848                 selnl_notify_policyload(seqno);
1849                 selinux_status_update_policyload(seqno);
1850                 selinux_netlbl_cache_invalidate();
1851                 selinux_xfrm_notify_policyload();
1852                 return 0;
1853         }
1854 
1855 #if 0
1856         sidtab_hash_eval(&sidtab, "sids");
1857 #endif
1858 
1859         rc = policydb_read(&newpolicydb, fp);
1860         if (rc)
1861                 return rc;
1862 
1863         newpolicydb.len = len;
1864         /* If switching between different policy types, log MLS status */
1865         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1866                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1867         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1868                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1869 
1870         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1871         if (rc) {
1872                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1873                 policydb_destroy(&newpolicydb);
1874                 return rc;
1875         }
1876 
1877         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1878         if (rc)
1879                 goto err;
1880 
1881         rc = security_preserve_bools(&newpolicydb);
1882         if (rc) {
1883                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1884                 goto err;
1885         }
1886 
1887         /* Clone the SID table. */
1888         sidtab_shutdown(&sidtab);
1889 
1890         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1891         if (rc)
1892                 goto err;
1893 
1894         /*
1895          * Convert the internal representations of contexts
1896          * in the new SID table.
1897          */
1898         args.oldp = &policydb;
1899         args.newp = &newpolicydb;
1900         rc = sidtab_map(&newsidtab, convert_context, &args);
1901         if (rc) {
1902                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1903                         " representation of contexts in the new SID"
1904                         " table\n");
1905                 goto err;
1906         }
1907 
1908         /* Save the old policydb and SID table to free later. */
1909         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1910         sidtab_set(&oldsidtab, &sidtab);
1911 
1912         /* Install the new policydb and SID table. */
1913         write_lock_irq(&policy_rwlock);
1914         memcpy(&policydb, &newpolicydb, sizeof policydb);
1915         sidtab_set(&sidtab, &newsidtab);
1916         security_load_policycaps();
1917         oldmap = current_mapping;
1918         current_mapping = map;
1919         current_mapping_size = map_size;
1920         seqno = ++latest_granting;
1921         write_unlock_irq(&policy_rwlock);
1922 
1923         /* Free the old policydb and SID table. */
1924         policydb_destroy(&oldpolicydb);
1925         sidtab_destroy(&oldsidtab);
1926         kfree(oldmap);
1927 
1928         avc_ss_reset(seqno);
1929         selnl_notify_policyload(seqno);
1930         selinux_status_update_policyload(seqno);
1931         selinux_netlbl_cache_invalidate();
1932         selinux_xfrm_notify_policyload();
1933 
1934         return 0;
1935 
1936 err:
1937         kfree(map);
1938         sidtab_destroy(&newsidtab);
1939         policydb_destroy(&newpolicydb);
1940         return rc;
1941 
1942 }
1943 
1944 size_t security_policydb_len(void)
1945 {
1946         size_t len;
1947 
1948         read_lock(&policy_rwlock);
1949         len = policydb.len;
1950         read_unlock(&policy_rwlock);
1951 
1952         return len;
1953 }
1954 
1955 /**
1956  * security_port_sid - Obtain the SID for a port.
1957  * @protocol: protocol number
1958  * @port: port number
1959  * @out_sid: security identifier
1960  */
1961 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1962 {
1963         struct ocontext *c;
1964         int rc = 0;
1965 
1966         read_lock(&policy_rwlock);
1967 
1968         c = policydb.ocontexts[OCON_PORT];
1969         while (c) {
1970                 if (c->u.port.protocol == protocol &&
1971                     c->u.port.low_port <= port &&
1972                     c->u.port.high_port >= port)
1973                         break;
1974                 c = c->next;
1975         }
1976 
1977         if (c) {
1978                 if (!c->sid[0]) {
1979                         rc = sidtab_context_to_sid(&sidtab,
1980                                                    &c->context[0],
1981                                                    &c->sid[0]);
1982                         if (rc)
1983                                 goto out;
1984                 }
1985                 *out_sid = c->sid[0];
1986         } else {
1987                 *out_sid = SECINITSID_PORT;
1988         }
1989 
1990 out:
1991         read_unlock(&policy_rwlock);
1992         return rc;
1993 }
1994 
1995 /**
1996  * security_netif_sid - Obtain the SID for a network interface.
1997  * @name: interface name
1998  * @if_sid: interface SID
1999  */
2000 int security_netif_sid(char *name, u32 *if_sid)
2001 {
2002         int rc = 0;
2003         struct ocontext *c;
2004 
2005         read_lock(&policy_rwlock);
2006 
2007         c = policydb.ocontexts[OCON_NETIF];
2008         while (c) {
2009                 if (strcmp(name, c->u.name) == 0)
2010                         break;
2011                 c = c->next;
2012         }
2013 
2014         if (c) {
2015                 if (!c->sid[0] || !c->sid[1]) {
2016                         rc = sidtab_context_to_sid(&sidtab,
2017                                                   &c->context[0],
2018                                                   &c->sid[0]);
2019                         if (rc)
2020                                 goto out;
2021                         rc = sidtab_context_to_sid(&sidtab,
2022                                                    &c->context[1],
2023                                                    &c->sid[1]);
2024                         if (rc)
2025                                 goto out;
2026                 }
2027                 *if_sid = c->sid[0];
2028         } else
2029                 *if_sid = SECINITSID_NETIF;
2030 
2031 out:
2032         read_unlock(&policy_rwlock);
2033         return rc;
2034 }
2035 
2036 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2037 {
2038         int i, fail = 0;
2039 
2040         for (i = 0; i < 4; i++)
2041                 if (addr[i] != (input[i] & mask[i])) {
2042                         fail = 1;
2043                         break;
2044                 }
2045 
2046         return !fail;
2047 }
2048 
2049 /**
2050  * security_node_sid - Obtain the SID for a node (host).
2051  * @domain: communication domain aka address family
2052  * @addrp: address
2053  * @addrlen: address length in bytes
2054  * @out_sid: security identifier
2055  */
2056 int security_node_sid(u16 domain,
2057                       void *addrp,
2058                       u32 addrlen,
2059                       u32 *out_sid)
2060 {
2061         int rc;
2062         struct ocontext *c;
2063 
2064         read_lock(&policy_rwlock);
2065 
2066         switch (domain) {
2067         case AF_INET: {
2068                 u32 addr;
2069 
2070                 rc = -EINVAL;
2071                 if (addrlen != sizeof(u32))
2072                         goto out;
2073 
2074                 addr = *((u32 *)addrp);
2075 
2076                 c = policydb.ocontexts[OCON_NODE];
2077                 while (c) {
2078                         if (c->u.node.addr == (addr & c->u.node.mask))
2079                                 break;
2080                         c = c->next;
2081                 }
2082                 break;
2083         }
2084 
2085         case AF_INET6:
2086                 rc = -EINVAL;
2087                 if (addrlen != sizeof(u64) * 2)
2088                         goto out;
2089                 c = policydb.ocontexts[OCON_NODE6];
2090                 while (c) {
2091                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2092                                                 c->u.node6.mask))
2093                                 break;
2094                         c = c->next;
2095                 }
2096                 break;
2097 
2098         default:
2099                 rc = 0;
2100                 *out_sid = SECINITSID_NODE;
2101                 goto out;
2102         }
2103 
2104         if (c) {
2105                 if (!c->sid[0]) {
2106                         rc = sidtab_context_to_sid(&sidtab,
2107                                                    &c->context[0],
2108                                                    &c->sid[0]);
2109                         if (rc)
2110                                 goto out;
2111                 }
2112                 *out_sid = c->sid[0];
2113         } else {
2114                 *out_sid = SECINITSID_NODE;
2115         }
2116 
2117         rc = 0;
2118 out:
2119         read_unlock(&policy_rwlock);
2120         return rc;
2121 }
2122 
2123 #define SIDS_NEL 25
2124 
2125 /**
2126  * security_get_user_sids - Obtain reachable SIDs for a user.
2127  * @fromsid: starting SID
2128  * @username: username
2129  * @sids: array of reachable SIDs for user
2130  * @nel: number of elements in @sids
2131  *
2132  * Generate the set of SIDs for legal security contexts
2133  * for a given user that can be reached by @fromsid.
2134  * Set *@sids to point to a dynamically allocated
2135  * array containing the set of SIDs.  Set *@nel to the
2136  * number of elements in the array.
2137  */
2138 
2139 int security_get_user_sids(u32 fromsid,
2140                            char *username,
2141                            u32 **sids,
2142                            u32 *nel)
2143 {
2144         struct context *fromcon, usercon;
2145         u32 *mysids = NULL, *mysids2, sid;
2146         u32 mynel = 0, maxnel = SIDS_NEL;
2147         struct user_datum *user;
2148         struct role_datum *role;
2149         struct ebitmap_node *rnode, *tnode;
2150         int rc = 0, i, j;
2151 
2152         *sids = NULL;
2153         *nel = 0;
2154 
2155         if (!ss_initialized)
2156                 goto out;
2157 
2158         read_lock(&policy_rwlock);
2159 
2160         context_init(&usercon);
2161 
2162         rc = -EINVAL;
2163         fromcon = sidtab_search(&sidtab, fromsid);
2164         if (!fromcon)
2165                 goto out_unlock;
2166 
2167         rc = -EINVAL;
2168         user = hashtab_search(policydb.p_users.table, username);
2169         if (!user)
2170                 goto out_unlock;
2171 
2172         usercon.user = user->value;
2173 
2174         rc = -ENOMEM;
2175         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2176         if (!mysids)
2177                 goto out_unlock;
2178 
2179         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2180                 role = policydb.role_val_to_struct[i];
2181                 usercon.role = i + 1;
2182                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2183                         usercon.type = j + 1;
2184 
2185                         if (mls_setup_user_range(fromcon, user, &usercon))
2186                                 continue;
2187 
2188                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2189                         if (rc)
2190                                 goto out_unlock;
2191                         if (mynel < maxnel) {
2192                                 mysids[mynel++] = sid;
2193                         } else {
2194                                 rc = -ENOMEM;
2195                                 maxnel += SIDS_NEL;
2196                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2197                                 if (!mysids2)
2198                                         goto out_unlock;
2199                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2200                                 kfree(mysids);
2201                                 mysids = mysids2;
2202                                 mysids[mynel++] = sid;
2203                         }
2204                 }
2205         }
2206         rc = 0;
2207 out_unlock:
2208         read_unlock(&policy_rwlock);
2209         if (rc || !mynel) {
2210                 kfree(mysids);
2211                 goto out;
2212         }
2213 
2214         rc = -ENOMEM;
2215         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2216         if (!mysids2) {
2217                 kfree(mysids);
2218                 goto out;
2219         }
2220         for (i = 0, j = 0; i < mynel; i++) {
2221                 struct av_decision dummy_avd;
2222                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2223                                           SECCLASS_PROCESS, /* kernel value */
2224                                           PROCESS__TRANSITION, AVC_STRICT,
2225                                           &dummy_avd);
2226                 if (!rc)
2227                         mysids2[j++] = mysids[i];
2228                 cond_resched();
2229         }
2230         rc = 0;
2231         kfree(mysids);
2232         *sids = mysids2;
2233         *nel = j;
2234 out:
2235         return rc;
2236 }
2237 
2238 /**
2239  * security_genfs_sid - Obtain a SID for a file in a filesystem
2240  * @fstype: filesystem type
2241  * @path: path from root of mount
2242  * @sclass: file security class
2243  * @sid: SID for path
2244  *
2245  * Obtain a SID to use for a file in a filesystem that
2246  * cannot support xattr or use a fixed labeling behavior like
2247  * transition SIDs or task SIDs.
2248  */
2249 int security_genfs_sid(const char *fstype,
2250                        char *path,
2251                        u16 orig_sclass,
2252                        u32 *sid)
2253 {
2254         int len;
2255         u16 sclass;
2256         struct genfs *genfs;
2257         struct ocontext *c;
2258         int rc, cmp = 0;
2259 
2260         while (path[0] == '/' && path[1] == '/')
2261                 path++;
2262 
2263         read_lock(&policy_rwlock);
2264 
2265         sclass = unmap_class(orig_sclass);
2266         *sid = SECINITSID_UNLABELED;
2267 
2268         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2269                 cmp = strcmp(fstype, genfs->fstype);
2270                 if (cmp <= 0)
2271                         break;
2272         }
2273 
2274         rc = -ENOENT;
2275         if (!genfs || cmp)
2276                 goto out;
2277 
2278         for (c = genfs->head; c; c = c->next) {
2279                 len = strlen(c->u.name);
2280                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2281                     (strncmp(c->u.name, path, len) == 0))
2282                         break;
2283         }
2284 
2285         rc = -ENOENT;
2286         if (!c)
2287                 goto out;
2288 
2289         if (!c->sid[0]) {
2290                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2291                 if (rc)
2292                         goto out;
2293         }
2294 
2295         *sid = c->sid[0];
2296         rc = 0;
2297 out:
2298         read_unlock(&policy_rwlock);
2299         return rc;
2300 }
2301 
2302 /**
2303  * security_fs_use - Determine how to handle labeling for a filesystem.
2304  * @fstype: filesystem type
2305  * @behavior: labeling behavior
2306  * @sid: SID for filesystem (superblock)
2307  */
2308 int security_fs_use(
2309         const char *fstype,
2310         unsigned int *behavior,
2311         u32 *sid)
2312 {
2313         int rc = 0;
2314         struct ocontext *c;
2315 
2316         read_lock(&policy_rwlock);
2317 
2318         c = policydb.ocontexts[OCON_FSUSE];
2319         while (c) {
2320                 if (strcmp(fstype, c->u.name) == 0)
2321                         break;
2322                 c = c->next;
2323         }
2324 
2325         if (c) {
2326                 *behavior = c->v.behavior;
2327                 if (!c->sid[0]) {
2328                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2329                                                    &c->sid[0]);
2330                         if (rc)
2331                                 goto out;
2332                 }
2333                 *sid = c->sid[0];
2334         } else {
2335                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2336                 if (rc) {
2337                         *behavior = SECURITY_FS_USE_NONE;
2338                         rc = 0;
2339                 } else {
2340                         *behavior = SECURITY_FS_USE_GENFS;
2341                 }
2342         }
2343 
2344 out:
2345         read_unlock(&policy_rwlock);
2346         return rc;
2347 }
2348 
2349 int security_get_bools(int *len, char ***names, int **values)
2350 {
2351         int i, rc;
2352 
2353         read_lock(&policy_rwlock);
2354         *names = NULL;
2355         *values = NULL;
2356 
2357         rc = 0;
2358         *len = policydb.p_bools.nprim;
2359         if (!*len)
2360                 goto out;
2361 
2362         rc = -ENOMEM;
2363         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2364         if (!*names)
2365                 goto err;
2366 
2367         rc = -ENOMEM;
2368         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2369         if (!*values)
2370                 goto err;
2371 
2372         for (i = 0; i < *len; i++) {
2373                 size_t name_len;
2374 
2375                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2376                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2377 
2378                 rc = -ENOMEM;
2379                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2380                 if (!(*names)[i])
2381                         goto err;
2382 
2383                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2384                 (*names)[i][name_len - 1] = 0;
2385         }
2386         rc = 0;
2387 out:
2388         read_unlock(&policy_rwlock);
2389         return rc;
2390 err:
2391         if (*names) {
2392                 for (i = 0; i < *len; i++)
2393                         kfree((*names)[i]);
2394         }
2395         kfree(*values);
2396         goto out;
2397 }
2398 
2399 
2400 int security_set_bools(int len, int *values)
2401 {
2402         int i, rc;
2403         int lenp, seqno = 0;
2404         struct cond_node *cur;
2405 
2406         write_lock_irq(&policy_rwlock);
2407 
2408         rc = -EFAULT;
2409         lenp = policydb.p_bools.nprim;
2410         if (len != lenp)
2411                 goto out;
2412 
2413         for (i = 0; i < len; i++) {
2414                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2415                         audit_log(current->audit_context, GFP_ATOMIC,
2416                                 AUDIT_MAC_CONFIG_CHANGE,
2417                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2418                                 sym_name(&policydb, SYM_BOOLS, i),
2419                                 !!values[i],
2420                                 policydb.bool_val_to_struct[i]->state,
2421                                 audit_get_loginuid(current),
2422                                 audit_get_sessionid(current));
2423                 }
2424                 if (values[i])
2425                         policydb.bool_val_to_struct[i]->state = 1;
2426                 else
2427                         policydb.bool_val_to_struct[i]->state = 0;
2428         }
2429 
2430         for (cur = policydb.cond_list; cur; cur = cur->next) {
2431                 rc = evaluate_cond_node(&policydb, cur);
2432                 if (rc)
2433                         goto out;
2434         }
2435 
2436         seqno = ++latest_granting;
2437         rc = 0;
2438 out:
2439         write_unlock_irq(&policy_rwlock);
2440         if (!rc) {
2441                 avc_ss_reset(seqno);
2442                 selnl_notify_policyload(seqno);
2443                 selinux_status_update_policyload(seqno);
2444                 selinux_xfrm_notify_policyload();
2445         }
2446         return rc;
2447 }
2448 
2449 int security_get_bool_value(int bool)
2450 {
2451         int rc;
2452         int len;
2453 
2454         read_lock(&policy_rwlock);
2455 
2456         rc = -EFAULT;
2457         len = policydb.p_bools.nprim;
2458         if (bool >= len)
2459                 goto out;
2460 
2461         rc = policydb.bool_val_to_struct[bool]->state;
2462 out:
2463         read_unlock(&policy_rwlock);
2464         return rc;
2465 }
2466 
2467 static int security_preserve_bools(struct policydb *p)
2468 {
2469         int rc, nbools = 0, *bvalues = NULL, i;
2470         char **bnames = NULL;
2471         struct cond_bool_datum *booldatum;
2472         struct cond_node *cur;
2473 
2474         rc = security_get_bools(&nbools, &bnames, &bvalues);
2475         if (rc)
2476                 goto out;
2477         for (i = 0; i < nbools; i++) {
2478                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2479                 if (booldatum)
2480                         booldatum->state = bvalues[i];
2481         }
2482         for (cur = p->cond_list; cur; cur = cur->next) {
2483                 rc = evaluate_cond_node(p, cur);
2484                 if (rc)
2485                         goto out;
2486         }
2487 
2488 out:
2489         if (bnames) {
2490                 for (i = 0; i < nbools; i++)
2491                         kfree(bnames[i]);
2492         }
2493         kfree(bnames);
2494         kfree(bvalues);
2495         return rc;
2496 }
2497 
2498 /*
2499  * security_sid_mls_copy() - computes a new sid based on the given
2500  * sid and the mls portion of mls_sid.
2501  */
2502 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2503 {
2504         struct context *context1;
2505         struct context *context2;
2506         struct context newcon;
2507         char *s;
2508         u32 len;
2509         int rc;
2510 
2511         rc = 0;
2512         if (!ss_initialized || !policydb.mls_enabled) {
2513                 *new_sid = sid;
2514                 goto out;
2515         }
2516 
2517         context_init(&newcon);
2518 
2519         read_lock(&policy_rwlock);
2520 
2521         rc = -EINVAL;
2522         context1 = sidtab_search(&sidtab, sid);
2523         if (!context1) {
2524                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2525                         __func__, sid);
2526                 goto out_unlock;
2527         }
2528 
2529         rc = -EINVAL;
2530         context2 = sidtab_search(&sidtab, mls_sid);
2531         if (!context2) {
2532                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2533                         __func__, mls_sid);
2534                 goto out_unlock;
2535         }
2536 
2537         newcon.user = context1->user;
2538         newcon.role = context1->role;
2539         newcon.type = context1->type;
2540         rc = mls_context_cpy(&newcon, context2);
2541         if (rc)
2542                 goto out_unlock;
2543 
2544         /* Check the validity of the new context. */
2545         if (!policydb_context_isvalid(&policydb, &newcon)) {
2546                 rc = convert_context_handle_invalid_context(&newcon);
2547                 if (rc) {
2548                         if (!context_struct_to_string(&newcon, &s, &len)) {
2549                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2550                                           "security_sid_mls_copy: invalid context %s", s);
2551                                 kfree(s);
2552                         }
2553                         goto out_unlock;
2554                 }
2555         }
2556 
2557         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2558 out_unlock:
2559         read_unlock(&policy_rwlock);
2560         context_destroy(&newcon);
2561 out:
2562         return rc;
2563 }
2564 
2565 /**
2566  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2567  * @nlbl_sid: NetLabel SID
2568  * @nlbl_type: NetLabel labeling protocol type
2569  * @xfrm_sid: XFRM SID
2570  *
2571  * Description:
2572  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2573  * resolved into a single SID it is returned via @peer_sid and the function
2574  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2575  * returns a negative value.  A table summarizing the behavior is below:
2576  *
2577  *                                 | function return |      @sid
2578  *   ------------------------------+-----------------+-----------------
2579  *   no peer labels                |        0        |    SECSID_NULL
2580  *   single peer label             |        0        |    <peer_label>
2581  *   multiple, consistent labels   |        0        |    <peer_label>
2582  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2583  *
2584  */
2585 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2586                                  u32 xfrm_sid,
2587                                  u32 *peer_sid)
2588 {
2589         int rc;
2590         struct context *nlbl_ctx;
2591         struct context *xfrm_ctx;
2592 
2593         *peer_sid = SECSID_NULL;
2594 
2595         /* handle the common (which also happens to be the set of easy) cases
2596          * right away, these two if statements catch everything involving a
2597          * single or absent peer SID/label */
2598         if (xfrm_sid == SECSID_NULL) {
2599                 *peer_sid = nlbl_sid;
2600                 return 0;
2601         }
2602         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2603          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2604          * is present */
2605         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2606                 *peer_sid = xfrm_sid;
2607                 return 0;
2608         }
2609 
2610         /* we don't need to check ss_initialized here since the only way both
2611          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2612          * security server was initialized and ss_initialized was true */
2613         if (!policydb.mls_enabled)
2614                 return 0;
2615 
2616         read_lock(&policy_rwlock);
2617 
2618         rc = -EINVAL;
2619         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2620         if (!nlbl_ctx) {
2621                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2622                        __func__, nlbl_sid);
2623                 goto out;
2624         }
2625         rc = -EINVAL;
2626         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2627         if (!xfrm_ctx) {
2628                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2629                        __func__, xfrm_sid);
2630                 goto out;
2631         }
2632         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2633         if (rc)
2634                 goto out;
2635 
2636         /* at present NetLabel SIDs/labels really only carry MLS
2637          * information so if the MLS portion of the NetLabel SID
2638          * matches the MLS portion of the labeled XFRM SID/label
2639          * then pass along the XFRM SID as it is the most
2640          * expressive */
2641         *peer_sid = xfrm_sid;
2642 out:
2643         read_unlock(&policy_rwlock);
2644         return rc;
2645 }
2646 
2647 static int get_classes_callback(void *k, void *d, void *args)
2648 {
2649         struct class_datum *datum = d;
2650         char *name = k, **classes = args;
2651         int value = datum->value - 1;
2652 
2653         classes[value] = kstrdup(name, GFP_ATOMIC);
2654         if (!classes[value])
2655                 return -ENOMEM;
2656 
2657         return 0;
2658 }
2659 
2660 int security_get_classes(char ***classes, int *nclasses)
2661 {
2662         int rc;
2663 
2664         read_lock(&policy_rwlock);
2665 
2666         rc = -ENOMEM;
2667         *nclasses = policydb.p_classes.nprim;
2668         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2669         if (!*classes)
2670                 goto out;
2671 
2672         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2673                         *classes);
2674         if (rc) {
2675                 int i;
2676                 for (i = 0; i < *nclasses; i++)
2677                         kfree((*classes)[i]);
2678                 kfree(*classes);
2679         }
2680 
2681 out:
2682         read_unlock(&policy_rwlock);
2683         return rc;
2684 }
2685 
2686 static int get_permissions_callback(void *k, void *d, void *args)
2687 {
2688         struct perm_datum *datum = d;
2689         char *name = k, **perms = args;
2690         int value = datum->value - 1;
2691 
2692         perms[value] = kstrdup(name, GFP_ATOMIC);
2693         if (!perms[value])
2694                 return -ENOMEM;
2695 
2696         return 0;
2697 }
2698 
2699 int security_get_permissions(char *class, char ***perms, int *nperms)
2700 {
2701         int rc, i;
2702         struct class_datum *match;
2703 
2704         read_lock(&policy_rwlock);
2705 
2706         rc = -EINVAL;
2707         match = hashtab_search(policydb.p_classes.table, class);
2708         if (!match) {
2709                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2710                         __func__, class);
2711                 goto out;
2712         }
2713 
2714         rc = -ENOMEM;
2715         *nperms = match->permissions.nprim;
2716         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2717         if (!*perms)
2718                 goto out;
2719 
2720         if (match->comdatum) {
2721                 rc = hashtab_map(match->comdatum->permissions.table,
2722                                 get_permissions_callback, *perms);
2723                 if (rc)
2724                         goto err;
2725         }
2726 
2727         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2728                         *perms);
2729         if (rc)
2730                 goto err;
2731 
2732 out:
2733         read_unlock(&policy_rwlock);
2734         return rc;
2735 
2736 err:
2737         read_unlock(&policy_rwlock);
2738         for (i = 0; i < *nperms; i++)
2739                 kfree((*perms)[i]);
2740         kfree(*perms);
2741         return rc;
2742 }
2743 
2744 int security_get_reject_unknown(void)
2745 {
2746         return policydb.reject_unknown;
2747 }
2748 
2749 int security_get_allow_unknown(void)
2750 {
2751         return policydb.allow_unknown;
2752 }
2753 
2754 /**
2755  * security_policycap_supported - Check for a specific policy capability
2756  * @req_cap: capability
2757  *
2758  * Description:
2759  * This function queries the currently loaded policy to see if it supports the
2760  * capability specified by @req_cap.  Returns true (1) if the capability is
2761  * supported, false (0) if it isn't supported.
2762  *
2763  */
2764 int security_policycap_supported(unsigned int req_cap)
2765 {
2766         int rc;
2767 
2768         read_lock(&policy_rwlock);
2769         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2770         read_unlock(&policy_rwlock);
2771 
2772         return rc;
2773 }
2774 
2775 struct selinux_audit_rule {
2776         u32 au_seqno;
2777         struct context au_ctxt;
2778 };
2779 
2780 void selinux_audit_rule_free(void *vrule)
2781 {
2782         struct selinux_audit_rule *rule = vrule;
2783 
2784         if (rule) {
2785                 context_destroy(&rule->au_ctxt);
2786                 kfree(rule);
2787         }
2788 }
2789 
2790 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2791 {
2792         struct selinux_audit_rule *tmprule;
2793         struct role_datum *roledatum;
2794         struct type_datum *typedatum;
2795         struct user_datum *userdatum;
2796         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2797         int rc = 0;
2798 
2799         *rule = NULL;
2800 
2801         if (!ss_initialized)
2802                 return -EOPNOTSUPP;
2803 
2804         switch (field) {
2805         case AUDIT_SUBJ_USER:
2806         case AUDIT_SUBJ_ROLE:
2807         case AUDIT_SUBJ_TYPE:
2808         case AUDIT_OBJ_USER:
2809         case AUDIT_OBJ_ROLE:
2810         case AUDIT_OBJ_TYPE:
2811                 /* only 'equals' and 'not equals' fit user, role, and type */
2812                 if (op != Audit_equal && op != Audit_not_equal)
2813                         return -EINVAL;
2814                 break;
2815         case AUDIT_SUBJ_SEN:
2816         case AUDIT_SUBJ_CLR:
2817         case AUDIT_OBJ_LEV_LOW:
2818         case AUDIT_OBJ_LEV_HIGH:
2819                 /* we do not allow a range, indicated by the presence of '-' */
2820                 if (strchr(rulestr, '-'))
2821                         return -EINVAL;
2822                 break;
2823         default:
2824                 /* only the above fields are valid */
2825                 return -EINVAL;
2826         }
2827 
2828         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2829         if (!tmprule)
2830                 return -ENOMEM;
2831 
2832         context_init(&tmprule->au_ctxt);
2833 
2834         read_lock(&policy_rwlock);
2835 
2836         tmprule->au_seqno = latest_granting;
2837 
2838         switch (field) {
2839         case AUDIT_SUBJ_USER:
2840         case AUDIT_OBJ_USER:
2841                 rc = -EINVAL;
2842                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2843                 if (!userdatum)
2844                         goto out;
2845                 tmprule->au_ctxt.user = userdatum->value;
2846                 break;
2847         case AUDIT_SUBJ_ROLE:
2848         case AUDIT_OBJ_ROLE:
2849                 rc = -EINVAL;
2850                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2851                 if (!roledatum)
2852                         goto out;
2853                 tmprule->au_ctxt.role = roledatum->value;
2854                 break;
2855         case AUDIT_SUBJ_TYPE:
2856         case AUDIT_OBJ_TYPE:
2857                 rc = -EINVAL;
2858                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2859                 if (!typedatum)
2860                         goto out;
2861                 tmprule->au_ctxt.type = typedatum->value;
2862                 break;
2863         case AUDIT_SUBJ_SEN:
2864         case AUDIT_SUBJ_CLR:
2865         case AUDIT_OBJ_LEV_LOW:
2866         case AUDIT_OBJ_LEV_HIGH:
2867                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2868                 if (rc)
2869                         goto out;
2870                 break;
2871         }
2872         rc = 0;
2873 out:
2874         read_unlock(&policy_rwlock);
2875 
2876         if (rc) {
2877                 selinux_audit_rule_free(tmprule);
2878                 tmprule = NULL;
2879         }
2880 
2881         *rule = tmprule;
2882 
2883         return rc;
2884 }
2885 
2886 /* Check to see if the rule contains any selinux fields */
2887 int selinux_audit_rule_known(struct audit_krule *rule)
2888 {
2889         int i;
2890 
2891         for (i = 0; i < rule->field_count; i++) {
2892                 struct audit_field *f = &rule->fields[i];
2893                 switch (f->type) {
2894                 case AUDIT_SUBJ_USER:
2895                 case AUDIT_SUBJ_ROLE:
2896                 case AUDIT_SUBJ_TYPE:
2897                 case AUDIT_SUBJ_SEN:
2898                 case AUDIT_SUBJ_CLR:
2899                 case AUDIT_OBJ_USER:
2900                 case AUDIT_OBJ_ROLE:
2901                 case AUDIT_OBJ_TYPE:
2902                 case AUDIT_OBJ_LEV_LOW:
2903                 case AUDIT_OBJ_LEV_HIGH:
2904                         return 1;
2905                 }
2906         }
2907 
2908         return 0;
2909 }
2910 
2911 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2912                              struct audit_context *actx)
2913 {
2914         struct context *ctxt;
2915         struct mls_level *level;
2916         struct selinux_audit_rule *rule = vrule;
2917         int match = 0;
2918 
2919         if (!rule) {
2920                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2921                           "selinux_audit_rule_match: missing rule\n");
2922                 return -ENOENT;
2923         }
2924 
2925         read_lock(&policy_rwlock);
2926 
2927         if (rule->au_seqno < latest_granting) {
2928                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2929                           "selinux_audit_rule_match: stale rule\n");
2930                 match = -ESTALE;
2931                 goto out;
2932         }
2933 
2934         ctxt = sidtab_search(&sidtab, sid);
2935         if (!ctxt) {
2936                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2937                           "selinux_audit_rule_match: unrecognized SID %d\n",
2938                           sid);
2939                 match = -ENOENT;
2940                 goto out;
2941         }
2942 
2943         /* a field/op pair that is not caught here will simply fall through
2944            without a match */
2945         switch (field) {
2946         case AUDIT_SUBJ_USER:
2947         case AUDIT_OBJ_USER:
2948                 switch (op) {
2949                 case Audit_equal:
2950                         match = (ctxt->user == rule->au_ctxt.user);
2951                         break;
2952                 case Audit_not_equal:
2953                         match = (ctxt->user != rule->au_ctxt.user);
2954                         break;
2955                 }
2956                 break;
2957         case AUDIT_SUBJ_ROLE:
2958         case AUDIT_OBJ_ROLE:
2959                 switch (op) {
2960                 case Audit_equal:
2961                         match = (ctxt->role == rule->au_ctxt.role);
2962                         break;
2963                 case Audit_not_equal:
2964                         match = (ctxt->role != rule->au_ctxt.role);
2965                         break;
2966                 }
2967                 break;
2968         case AUDIT_SUBJ_TYPE:
2969         case AUDIT_OBJ_TYPE:
2970                 switch (op) {
2971                 case Audit_equal:
2972                         match = (ctxt->type == rule->au_ctxt.type);
2973                         break;
2974                 case Audit_not_equal:
2975                         match = (ctxt->type != rule->au_ctxt.type);
2976                         break;
2977                 }
2978                 break;
2979         case AUDIT_SUBJ_SEN:
2980         case AUDIT_SUBJ_CLR:
2981         case AUDIT_OBJ_LEV_LOW:
2982         case AUDIT_OBJ_LEV_HIGH:
2983                 level = ((field == AUDIT_SUBJ_SEN ||
2984                           field == AUDIT_OBJ_LEV_LOW) ?
2985                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2986                 switch (op) {
2987                 case Audit_equal:
2988                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2989                                              level);
2990                         break;
2991                 case Audit_not_equal:
2992                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2993                                               level);
2994                         break;
2995                 case Audit_lt:
2996                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2997                                                level) &&
2998                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2999                                                level));
3000                         break;
3001                 case Audit_le:
3002                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3003                                               level);
3004                         break;
3005                 case Audit_gt:
3006                         match = (mls_level_dom(level,
3007                                               &rule->au_ctxt.range.level[0]) &&
3008                                  !mls_level_eq(level,
3009                                                &rule->au_ctxt.range.level[0]));
3010                         break;
3011                 case Audit_ge:
3012                         match = mls_level_dom(level,
3013                                               &rule->au_ctxt.range.level[0]);
3014                         break;
3015                 }
3016         }
3017 
3018 out:
3019         read_unlock(&policy_rwlock);
3020         return match;
3021 }
3022 
3023 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3024 
3025 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3026                                u16 class, u32 perms, u32 *retained)
3027 {
3028         int err = 0;
3029 
3030         if (event == AVC_CALLBACK_RESET && aurule_callback)
3031                 err = aurule_callback();
3032         return err;
3033 }
3034 
3035 static int __init aurule_init(void)
3036 {
3037         int err;
3038 
3039         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3040                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3041         if (err)
3042                 panic("avc_add_callback() failed, error %d\n", err);
3043 
3044         return err;
3045 }
3046 __initcall(aurule_init);
3047 
3048 #ifdef CONFIG_NETLABEL
3049 /**
3050  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3051  * @secattr: the NetLabel packet security attributes
3052  * @sid: the SELinux SID
3053  *
3054  * Description:
3055  * Attempt to cache the context in @ctx, which was derived from the packet in
3056  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3057  * already been initialized.
3058  *
3059  */
3060 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3061                                       u32 sid)
3062 {
3063         u32 *sid_cache;
3064 
3065         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3066         if (sid_cache == NULL)
3067                 return;
3068         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3069         if (secattr->cache == NULL) {
3070                 kfree(sid_cache);
3071                 return;
3072         }
3073 
3074         *sid_cache = sid;
3075         secattr->cache->free = kfree;
3076         secattr->cache->data = sid_cache;
3077         secattr->flags |= NETLBL_SECATTR_CACHE;
3078 }
3079 
3080 /**
3081  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3082  * @secattr: the NetLabel packet security attributes
3083  * @sid: the SELinux SID
3084  *
3085  * Description:
3086  * Convert the given NetLabel security attributes in @secattr into a
3087  * SELinux SID.  If the @secattr field does not contain a full SELinux
3088  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3089  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3090  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3091  * conversion for future lookups.  Returns zero on success, negative values on
3092  * failure.
3093  *
3094  */
3095 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3096                                    u32 *sid)
3097 {
3098         int rc;
3099         struct context *ctx;
3100         struct context ctx_new;
3101 
3102         if (!ss_initialized) {
3103                 *sid = SECSID_NULL;
3104                 return 0;
3105         }
3106 
3107         read_lock(&policy_rwlock);
3108 
3109         if (secattr->flags & NETLBL_SECATTR_CACHE)
3110                 *sid = *(u32 *)secattr->cache->data;
3111         else if (secattr->flags & NETLBL_SECATTR_SECID)
3112                 *sid = secattr->attr.secid;
3113         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3114                 rc = -EIDRM;
3115                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3116                 if (ctx == NULL)
3117                         goto out;
3118 
3119                 context_init(&ctx_new);
3120                 ctx_new.user = ctx->user;
3121                 ctx_new.role = ctx->role;
3122                 ctx_new.type = ctx->type;
3123                 mls_import_netlbl_lvl(&ctx_new, secattr);
3124                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3125                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3126                                                    secattr->attr.mls.cat);
3127                         if (rc)
3128                                 goto out;
3129                         memcpy(&ctx_new.range.level[1].cat,
3130                                &ctx_new.range.level[0].cat,
3131                                sizeof(ctx_new.range.level[0].cat));
3132                 }
3133                 rc = -EIDRM;
3134                 if (!mls_context_isvalid(&policydb, &ctx_new))
3135                         goto out_free;
3136 
3137                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3138                 if (rc)
3139                         goto out_free;
3140 
3141                 security_netlbl_cache_add(secattr, *sid);
3142 
3143                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3144         } else
3145                 *sid = SECSID_NULL;
3146 
3147         read_unlock(&policy_rwlock);
3148         return 0;
3149 out_free:
3150         ebitmap_destroy(&ctx_new.range.level[0].cat);
3151 out:
3152         read_unlock(&policy_rwlock);
3153         return rc;
3154 }
3155 
3156 /**
3157  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3158  * @sid: the SELinux SID
3159  * @secattr: the NetLabel packet security attributes
3160  *
3161  * Description:
3162  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3163  * Returns zero on success, negative values on failure.
3164  *
3165  */
3166 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3167 {
3168         int rc;
3169         struct context *ctx;
3170 
3171         if (!ss_initialized)
3172                 return 0;
3173 
3174         read_lock(&policy_rwlock);
3175 
3176         rc = -ENOENT;
3177         ctx = sidtab_search(&sidtab, sid);
3178         if (ctx == NULL)
3179                 goto out;
3180 
3181         rc = -ENOMEM;
3182         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3183                                   GFP_ATOMIC);
3184         if (secattr->domain == NULL)
3185                 goto out;
3186 
3187         secattr->attr.secid = sid;
3188         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3189         mls_export_netlbl_lvl(ctx, secattr);
3190         rc = mls_export_netlbl_cat(ctx, secattr);
3191 out:
3192         read_unlock(&policy_rwlock);
3193         return rc;
3194 }
3195 #endif /* CONFIG_NETLABEL */
3196 
3197 /**
3198  * security_read_policy - read the policy.
3199  * @data: binary policy data
3200  * @len: length of data in bytes
3201  *
3202  */
3203 int security_read_policy(void **data, size_t *len)
3204 {
3205         int rc;
3206         struct policy_file fp;
3207 
3208         if (!ss_initialized)
3209                 return -EINVAL;
3210 
3211         *len = security_policydb_len();
3212 
3213         *data = vmalloc_user(*len);
3214         if (!*data)
3215                 return -ENOMEM;
3216 
3217         fp.data = *data;
3218         fp.len = *len;
3219 
3220         read_lock(&policy_rwlock);
3221         rc = policydb_write(&policydb, &fp);
3222         read_unlock(&policy_rwlock);
3223 
3224         if (rc)
3225                 return rc;
3226 
3227         *len = (unsigned long)fp.data - (unsigned long)*data;
3228         return 0;
3229 
3230 }
3231 

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