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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 int selinux_policycap_alwaysnetwork;
 76 
 77 static DEFINE_RWLOCK(policy_rwlock);
 78 
 79 static struct sidtab sidtab;
 80 struct policydb policydb;
 81 int ss_initialized;
 82 
 83 /*
 84  * The largest sequence number that has been used when
 85  * providing an access decision to the access vector cache.
 86  * The sequence number only changes when a policy change
 87  * occurs.
 88  */
 89 static u32 latest_granting;
 90 
 91 /* Forward declaration. */
 92 static int context_struct_to_string(struct context *context, char **scontext,
 93                                     u32 *scontext_len);
 94 
 95 static void context_struct_compute_av(struct context *scontext,
 96                                         struct context *tcontext,
 97                                         u16 tclass,
 98                                         struct av_decision *avd,
 99                                         struct extended_perms *xperms);
100 
101 struct selinux_mapping {
102         u16 value; /* policy value */
103         unsigned num_perms;
104         u32 perms[sizeof(u32) * 8];
105 };
106 
107 static struct selinux_mapping *current_mapping;
108 static u16 current_mapping_size;
109 
110 static int selinux_set_mapping(struct policydb *pol,
111                                struct security_class_mapping *map,
112                                struct selinux_mapping **out_map_p,
113                                u16 *out_map_size)
114 {
115         struct selinux_mapping *out_map = NULL;
116         size_t size = sizeof(struct selinux_mapping);
117         u16 i, j;
118         unsigned k;
119         bool print_unknown_handle = false;
120 
121         /* Find number of classes in the input mapping */
122         if (!map)
123                 return -EINVAL;
124         i = 0;
125         while (map[i].name)
126                 i++;
127 
128         /* Allocate space for the class records, plus one for class zero */
129         out_map = kcalloc(++i, size, GFP_ATOMIC);
130         if (!out_map)
131                 return -ENOMEM;
132 
133         /* Store the raw class and permission values */
134         j = 0;
135         while (map[j].name) {
136                 struct security_class_mapping *p_in = map + (j++);
137                 struct selinux_mapping *p_out = out_map + j;
138 
139                 /* An empty class string skips ahead */
140                 if (!strcmp(p_in->name, "")) {
141                         p_out->num_perms = 0;
142                         continue;
143                 }
144 
145                 p_out->value = string_to_security_class(pol, p_in->name);
146                 if (!p_out->value) {
147                         printk(KERN_INFO
148                                "SELinux:  Class %s not defined in policy.\n",
149                                p_in->name);
150                         if (pol->reject_unknown)
151                                 goto err;
152                         p_out->num_perms = 0;
153                         print_unknown_handle = true;
154                         continue;
155                 }
156 
157                 k = 0;
158                 while (p_in->perms && p_in->perms[k]) {
159                         /* An empty permission string skips ahead */
160                         if (!*p_in->perms[k]) {
161                                 k++;
162                                 continue;
163                         }
164                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
165                                                             p_in->perms[k]);
166                         if (!p_out->perms[k]) {
167                                 printk(KERN_INFO
168                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
169                                        p_in->perms[k], p_in->name);
170                                 if (pol->reject_unknown)
171                                         goto err;
172                                 print_unknown_handle = true;
173                         }
174 
175                         k++;
176                 }
177                 p_out->num_perms = k;
178         }
179 
180         if (print_unknown_handle)
181                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
182                        pol->allow_unknown ? "allowed" : "denied");
183 
184         *out_map_p = out_map;
185         *out_map_size = i;
186         return 0;
187 err:
188         kfree(out_map);
189         return -EINVAL;
190 }
191 
192 /*
193  * Get real, policy values from mapped values
194  */
195 
196 static u16 unmap_class(u16 tclass)
197 {
198         if (tclass < current_mapping_size)
199                 return current_mapping[tclass].value;
200 
201         return tclass;
202 }
203 
204 /*
205  * Get kernel value for class from its policy value
206  */
207 static u16 map_class(u16 pol_value)
208 {
209         u16 i;
210 
211         for (i = 1; i < current_mapping_size; i++) {
212                 if (current_mapping[i].value == pol_value)
213                         return i;
214         }
215 
216         return SECCLASS_NULL;
217 }
218 
219 static void map_decision(u16 tclass, struct av_decision *avd,
220                          int allow_unknown)
221 {
222         if (tclass < current_mapping_size) {
223                 unsigned i, n = current_mapping[tclass].num_perms;
224                 u32 result;
225 
226                 for (i = 0, result = 0; i < n; i++) {
227                         if (avd->allowed & current_mapping[tclass].perms[i])
228                                 result |= 1<<i;
229                         if (allow_unknown && !current_mapping[tclass].perms[i])
230                                 result |= 1<<i;
231                 }
232                 avd->allowed = result;
233 
234                 for (i = 0, result = 0; i < n; i++)
235                         if (avd->auditallow & current_mapping[tclass].perms[i])
236                                 result |= 1<<i;
237                 avd->auditallow = result;
238 
239                 for (i = 0, result = 0; i < n; i++) {
240                         if (avd->auditdeny & current_mapping[tclass].perms[i])
241                                 result |= 1<<i;
242                         if (!allow_unknown && !current_mapping[tclass].perms[i])
243                                 result |= 1<<i;
244                 }
245                 /*
246                  * In case the kernel has a bug and requests a permission
247                  * between num_perms and the maximum permission number, we
248                  * should audit that denial
249                  */
250                 for (; i < (sizeof(u32)*8); i++)
251                         result |= 1<<i;
252                 avd->auditdeny = result;
253         }
254 }
255 
256 int security_mls_enabled(void)
257 {
258         return policydb.mls_enabled;
259 }
260 
261 /*
262  * Return the boolean value of a constraint expression
263  * when it is applied to the specified source and target
264  * security contexts.
265  *
266  * xcontext is a special beast...  It is used by the validatetrans rules
267  * only.  For these rules, scontext is the context before the transition,
268  * tcontext is the context after the transition, and xcontext is the context
269  * of the process performing the transition.  All other callers of
270  * constraint_expr_eval should pass in NULL for xcontext.
271  */
272 static int constraint_expr_eval(struct context *scontext,
273                                 struct context *tcontext,
274                                 struct context *xcontext,
275                                 struct constraint_expr *cexpr)
276 {
277         u32 val1, val2;
278         struct context *c;
279         struct role_datum *r1, *r2;
280         struct mls_level *l1, *l2;
281         struct constraint_expr *e;
282         int s[CEXPR_MAXDEPTH];
283         int sp = -1;
284 
285         for (e = cexpr; e; e = e->next) {
286                 switch (e->expr_type) {
287                 case CEXPR_NOT:
288                         BUG_ON(sp < 0);
289                         s[sp] = !s[sp];
290                         break;
291                 case CEXPR_AND:
292                         BUG_ON(sp < 1);
293                         sp--;
294                         s[sp] &= s[sp + 1];
295                         break;
296                 case CEXPR_OR:
297                         BUG_ON(sp < 1);
298                         sp--;
299                         s[sp] |= s[sp + 1];
300                         break;
301                 case CEXPR_ATTR:
302                         if (sp == (CEXPR_MAXDEPTH - 1))
303                                 return 0;
304                         switch (e->attr) {
305                         case CEXPR_USER:
306                                 val1 = scontext->user;
307                                 val2 = tcontext->user;
308                                 break;
309                         case CEXPR_TYPE:
310                                 val1 = scontext->type;
311                                 val2 = tcontext->type;
312                                 break;
313                         case CEXPR_ROLE:
314                                 val1 = scontext->role;
315                                 val2 = tcontext->role;
316                                 r1 = policydb.role_val_to_struct[val1 - 1];
317                                 r2 = policydb.role_val_to_struct[val2 - 1];
318                                 switch (e->op) {
319                                 case CEXPR_DOM:
320                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
321                                                                   val2 - 1);
322                                         continue;
323                                 case CEXPR_DOMBY:
324                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
325                                                                   val1 - 1);
326                                         continue;
327                                 case CEXPR_INCOMP:
328                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
329                                                                     val2 - 1) &&
330                                                    !ebitmap_get_bit(&r2->dominates,
331                                                                     val1 - 1));
332                                         continue;
333                                 default:
334                                         break;
335                                 }
336                                 break;
337                         case CEXPR_L1L2:
338                                 l1 = &(scontext->range.level[0]);
339                                 l2 = &(tcontext->range.level[0]);
340                                 goto mls_ops;
341                         case CEXPR_L1H2:
342                                 l1 = &(scontext->range.level[0]);
343                                 l2 = &(tcontext->range.level[1]);
344                                 goto mls_ops;
345                         case CEXPR_H1L2:
346                                 l1 = &(scontext->range.level[1]);
347                                 l2 = &(tcontext->range.level[0]);
348                                 goto mls_ops;
349                         case CEXPR_H1H2:
350                                 l1 = &(scontext->range.level[1]);
351                                 l2 = &(tcontext->range.level[1]);
352                                 goto mls_ops;
353                         case CEXPR_L1H1:
354                                 l1 = &(scontext->range.level[0]);
355                                 l2 = &(scontext->range.level[1]);
356                                 goto mls_ops;
357                         case CEXPR_L2H2:
358                                 l1 = &(tcontext->range.level[0]);
359                                 l2 = &(tcontext->range.level[1]);
360                                 goto mls_ops;
361 mls_ops:
362                         switch (e->op) {
363                         case CEXPR_EQ:
364                                 s[++sp] = mls_level_eq(l1, l2);
365                                 continue;
366                         case CEXPR_NEQ:
367                                 s[++sp] = !mls_level_eq(l1, l2);
368                                 continue;
369                         case CEXPR_DOM:
370                                 s[++sp] = mls_level_dom(l1, l2);
371                                 continue;
372                         case CEXPR_DOMBY:
373                                 s[++sp] = mls_level_dom(l2, l1);
374                                 continue;
375                         case CEXPR_INCOMP:
376                                 s[++sp] = mls_level_incomp(l2, l1);
377                                 continue;
378                         default:
379                                 BUG();
380                                 return 0;
381                         }
382                         break;
383                         default:
384                                 BUG();
385                                 return 0;
386                         }
387 
388                         switch (e->op) {
389                         case CEXPR_EQ:
390                                 s[++sp] = (val1 == val2);
391                                 break;
392                         case CEXPR_NEQ:
393                                 s[++sp] = (val1 != val2);
394                                 break;
395                         default:
396                                 BUG();
397                                 return 0;
398                         }
399                         break;
400                 case CEXPR_NAMES:
401                         if (sp == (CEXPR_MAXDEPTH-1))
402                                 return 0;
403                         c = scontext;
404                         if (e->attr & CEXPR_TARGET)
405                                 c = tcontext;
406                         else if (e->attr & CEXPR_XTARGET) {
407                                 c = xcontext;
408                                 if (!c) {
409                                         BUG();
410                                         return 0;
411                                 }
412                         }
413                         if (e->attr & CEXPR_USER)
414                                 val1 = c->user;
415                         else if (e->attr & CEXPR_ROLE)
416                                 val1 = c->role;
417                         else if (e->attr & CEXPR_TYPE)
418                                 val1 = c->type;
419                         else {
420                                 BUG();
421                                 return 0;
422                         }
423 
424                         switch (e->op) {
425                         case CEXPR_EQ:
426                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
427                                 break;
428                         case CEXPR_NEQ:
429                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
430                                 break;
431                         default:
432                                 BUG();
433                                 return 0;
434                         }
435                         break;
436                 default:
437                         BUG();
438                         return 0;
439                 }
440         }
441 
442         BUG_ON(sp != 0);
443         return s[0];
444 }
445 
446 /*
447  * security_dump_masked_av - dumps masked permissions during
448  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
449  */
450 static int dump_masked_av_helper(void *k, void *d, void *args)
451 {
452         struct perm_datum *pdatum = d;
453         char **permission_names = args;
454 
455         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
456 
457         permission_names[pdatum->value - 1] = (char *)k;
458 
459         return 0;
460 }
461 
462 static void security_dump_masked_av(struct context *scontext,
463                                     struct context *tcontext,
464                                     u16 tclass,
465                                     u32 permissions,
466                                     const char *reason)
467 {
468         struct common_datum *common_dat;
469         struct class_datum *tclass_dat;
470         struct audit_buffer *ab;
471         char *tclass_name;
472         char *scontext_name = NULL;
473         char *tcontext_name = NULL;
474         char *permission_names[32];
475         int index;
476         u32 length;
477         bool need_comma = false;
478 
479         if (!permissions)
480                 return;
481 
482         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
483         tclass_dat = policydb.class_val_to_struct[tclass - 1];
484         common_dat = tclass_dat->comdatum;
485 
486         /* init permission_names */
487         if (common_dat &&
488             hashtab_map(common_dat->permissions.table,
489                         dump_masked_av_helper, permission_names) < 0)
490                 goto out;
491 
492         if (hashtab_map(tclass_dat->permissions.table,
493                         dump_masked_av_helper, permission_names) < 0)
494                 goto out;
495 
496         /* get scontext/tcontext in text form */
497         if (context_struct_to_string(scontext,
498                                      &scontext_name, &length) < 0)
499                 goto out;
500 
501         if (context_struct_to_string(tcontext,
502                                      &tcontext_name, &length) < 0)
503                 goto out;
504 
505         /* audit a message */
506         ab = audit_log_start(current->audit_context,
507                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
508         if (!ab)
509                 goto out;
510 
511         audit_log_format(ab, "op=security_compute_av reason=%s "
512                          "scontext=%s tcontext=%s tclass=%s perms=",
513                          reason, scontext_name, tcontext_name, tclass_name);
514 
515         for (index = 0; index < 32; index++) {
516                 u32 mask = (1 << index);
517 
518                 if ((mask & permissions) == 0)
519                         continue;
520 
521                 audit_log_format(ab, "%s%s",
522                                  need_comma ? "," : "",
523                                  permission_names[index]
524                                  ? permission_names[index] : "????");
525                 need_comma = true;
526         }
527         audit_log_end(ab);
528 out:
529         /* release scontext/tcontext */
530         kfree(tcontext_name);
531         kfree(scontext_name);
532 
533         return;
534 }
535 
536 /*
537  * security_boundary_permission - drops violated permissions
538  * on boundary constraint.
539  */
540 static void type_attribute_bounds_av(struct context *scontext,
541                                      struct context *tcontext,
542                                      u16 tclass,
543                                      struct av_decision *avd)
544 {
545         struct context lo_scontext;
546         struct context lo_tcontext;
547         struct av_decision lo_avd;
548         struct type_datum *source;
549         struct type_datum *target;
550         u32 masked = 0;
551 
552         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
553                                     scontext->type - 1);
554         BUG_ON(!source);
555 
556         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
557                                     tcontext->type - 1);
558         BUG_ON(!target);
559 
560         if (source->bounds) {
561                 memset(&lo_avd, 0, sizeof(lo_avd));
562 
563                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
564                 lo_scontext.type = source->bounds;
565 
566                 context_struct_compute_av(&lo_scontext,
567                                           tcontext,
568                                           tclass,
569                                           &lo_avd,
570                                           NULL);
571                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
572                         return;         /* no masked permission */
573                 masked = ~lo_avd.allowed & avd->allowed;
574         }
575 
576         if (target->bounds) {
577                 memset(&lo_avd, 0, sizeof(lo_avd));
578 
579                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
580                 lo_tcontext.type = target->bounds;
581 
582                 context_struct_compute_av(scontext,
583                                           &lo_tcontext,
584                                           tclass,
585                                           &lo_avd,
586                                           NULL);
587                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
588                         return;         /* no masked permission */
589                 masked = ~lo_avd.allowed & avd->allowed;
590         }
591 
592         if (source->bounds && target->bounds) {
593                 memset(&lo_avd, 0, sizeof(lo_avd));
594                 /*
595                  * lo_scontext and lo_tcontext are already
596                  * set up.
597                  */
598 
599                 context_struct_compute_av(&lo_scontext,
600                                           &lo_tcontext,
601                                           tclass,
602                                           &lo_avd,
603                                           NULL);
604                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
605                         return;         /* no masked permission */
606                 masked = ~lo_avd.allowed & avd->allowed;
607         }
608 
609         if (masked) {
610                 /* mask violated permissions */
611                 avd->allowed &= ~masked;
612 
613                 /* audit masked permissions */
614                 security_dump_masked_av(scontext, tcontext,
615                                         tclass, masked, "bounds");
616         }
617 }
618 
619 /*
620  * flag which drivers have permissions
621  * only looking for ioctl based extended permssions
622  */
623 void services_compute_xperms_drivers(
624                 struct extended_perms *xperms,
625                 struct avtab_node *node)
626 {
627         unsigned int i;
628 
629         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
630                 /* if one or more driver has all permissions allowed */
631                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
632                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
633         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
634                 /* if allowing permissions within a driver */
635                 security_xperm_set(xperms->drivers.p,
636                                         node->datum.u.xperms->driver);
637         }
638 
639         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
640         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
641                 xperms->len = 1;
642 }
643 
644 /*
645  * Compute access vectors and extended permissions based on a context
646  * structure pair for the permissions in a particular class.
647  */
648 static void context_struct_compute_av(struct context *scontext,
649                                         struct context *tcontext,
650                                         u16 tclass,
651                                         struct av_decision *avd,
652                                         struct extended_perms *xperms)
653 {
654         struct constraint_node *constraint;
655         struct role_allow *ra;
656         struct avtab_key avkey;
657         struct avtab_node *node;
658         struct class_datum *tclass_datum;
659         struct ebitmap *sattr, *tattr;
660         struct ebitmap_node *snode, *tnode;
661         unsigned int i, j;
662 
663         avd->allowed = 0;
664         avd->auditallow = 0;
665         avd->auditdeny = 0xffffffff;
666         if (xperms) {
667                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
668                 xperms->len = 0;
669         }
670 
671         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
672                 if (printk_ratelimit())
673                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
674                 return;
675         }
676 
677         tclass_datum = policydb.class_val_to_struct[tclass - 1];
678 
679         /*
680          * If a specific type enforcement rule was defined for
681          * this permission check, then use it.
682          */
683         avkey.target_class = tclass;
684         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
685         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
686         BUG_ON(!sattr);
687         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
688         BUG_ON(!tattr);
689         ebitmap_for_each_positive_bit(sattr, snode, i) {
690                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
691                         avkey.source_type = i + 1;
692                         avkey.target_type = j + 1;
693                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
694                              node;
695                              node = avtab_search_node_next(node, avkey.specified)) {
696                                 if (node->key.specified == AVTAB_ALLOWED)
697                                         avd->allowed |= node->datum.u.data;
698                                 else if (node->key.specified == AVTAB_AUDITALLOW)
699                                         avd->auditallow |= node->datum.u.data;
700                                 else if (node->key.specified == AVTAB_AUDITDENY)
701                                         avd->auditdeny &= node->datum.u.data;
702                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
703                                         services_compute_xperms_drivers(xperms, node);
704                         }
705 
706                         /* Check conditional av table for additional permissions */
707                         cond_compute_av(&policydb.te_cond_avtab, &avkey,
708                                         avd, xperms);
709 
710                 }
711         }
712 
713         /*
714          * Remove any permissions prohibited by a constraint (this includes
715          * the MLS policy).
716          */
717         constraint = tclass_datum->constraints;
718         while (constraint) {
719                 if ((constraint->permissions & (avd->allowed)) &&
720                     !constraint_expr_eval(scontext, tcontext, NULL,
721                                           constraint->expr)) {
722                         avd->allowed &= ~(constraint->permissions);
723                 }
724                 constraint = constraint->next;
725         }
726 
727         /*
728          * If checking process transition permission and the
729          * role is changing, then check the (current_role, new_role)
730          * pair.
731          */
732         if (tclass == policydb.process_class &&
733             (avd->allowed & policydb.process_trans_perms) &&
734             scontext->role != tcontext->role) {
735                 for (ra = policydb.role_allow; ra; ra = ra->next) {
736                         if (scontext->role == ra->role &&
737                             tcontext->role == ra->new_role)
738                                 break;
739                 }
740                 if (!ra)
741                         avd->allowed &= ~policydb.process_trans_perms;
742         }
743 
744         /*
745          * If the given source and target types have boundary
746          * constraint, lazy checks have to mask any violated
747          * permission and notice it to userspace via audit.
748          */
749         type_attribute_bounds_av(scontext, tcontext,
750                                  tclass, avd);
751 }
752 
753 static int security_validtrans_handle_fail(struct context *ocontext,
754                                            struct context *ncontext,
755                                            struct context *tcontext,
756                                            u16 tclass)
757 {
758         char *o = NULL, *n = NULL, *t = NULL;
759         u32 olen, nlen, tlen;
760 
761         if (context_struct_to_string(ocontext, &o, &olen))
762                 goto out;
763         if (context_struct_to_string(ncontext, &n, &nlen))
764                 goto out;
765         if (context_struct_to_string(tcontext, &t, &tlen))
766                 goto out;
767         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
768                   "op=security_validate_transition seresult=denied"
769                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
770                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
771 out:
772         kfree(o);
773         kfree(n);
774         kfree(t);
775 
776         if (!selinux_enforcing)
777                 return 0;
778         return -EPERM;
779 }
780 
781 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
782                                           u16 orig_tclass, bool user)
783 {
784         struct context *ocontext;
785         struct context *ncontext;
786         struct context *tcontext;
787         struct class_datum *tclass_datum;
788         struct constraint_node *constraint;
789         u16 tclass;
790         int rc = 0;
791 
792         if (!ss_initialized)
793                 return 0;
794 
795         read_lock(&policy_rwlock);
796 
797         if (!user)
798                 tclass = unmap_class(orig_tclass);
799         else
800                 tclass = orig_tclass;
801 
802         if (!tclass || tclass > policydb.p_classes.nprim) {
803                 rc = -EINVAL;
804                 goto out;
805         }
806         tclass_datum = policydb.class_val_to_struct[tclass - 1];
807 
808         ocontext = sidtab_search(&sidtab, oldsid);
809         if (!ocontext) {
810                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
811                         __func__, oldsid);
812                 rc = -EINVAL;
813                 goto out;
814         }
815 
816         ncontext = sidtab_search(&sidtab, newsid);
817         if (!ncontext) {
818                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
819                         __func__, newsid);
820                 rc = -EINVAL;
821                 goto out;
822         }
823 
824         tcontext = sidtab_search(&sidtab, tasksid);
825         if (!tcontext) {
826                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
827                         __func__, tasksid);
828                 rc = -EINVAL;
829                 goto out;
830         }
831 
832         constraint = tclass_datum->validatetrans;
833         while (constraint) {
834                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
835                                           constraint->expr)) {
836                         if (user)
837                                 rc = -EPERM;
838                         else
839                                 rc = security_validtrans_handle_fail(ocontext,
840                                                                      ncontext,
841                                                                      tcontext,
842                                                                      tclass);
843                         goto out;
844                 }
845                 constraint = constraint->next;
846         }
847 
848 out:
849         read_unlock(&policy_rwlock);
850         return rc;
851 }
852 
853 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
854                                         u16 tclass)
855 {
856         return security_compute_validatetrans(oldsid, newsid, tasksid,
857                                                 tclass, true);
858 }
859 
860 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
861                                  u16 orig_tclass)
862 {
863         return security_compute_validatetrans(oldsid, newsid, tasksid,
864                                                 orig_tclass, false);
865 }
866 
867 /*
868  * security_bounded_transition - check whether the given
869  * transition is directed to bounded, or not.
870  * It returns 0, if @newsid is bounded by @oldsid.
871  * Otherwise, it returns error code.
872  *
873  * @oldsid : current security identifier
874  * @newsid : destinated security identifier
875  */
876 int security_bounded_transition(u32 old_sid, u32 new_sid)
877 {
878         struct context *old_context, *new_context;
879         struct type_datum *type;
880         int index;
881         int rc;
882 
883         read_lock(&policy_rwlock);
884 
885         rc = -EINVAL;
886         old_context = sidtab_search(&sidtab, old_sid);
887         if (!old_context) {
888                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
889                        __func__, old_sid);
890                 goto out;
891         }
892 
893         rc = -EINVAL;
894         new_context = sidtab_search(&sidtab, new_sid);
895         if (!new_context) {
896                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
897                        __func__, new_sid);
898                 goto out;
899         }
900 
901         rc = 0;
902         /* type/domain unchanged */
903         if (old_context->type == new_context->type)
904                 goto out;
905 
906         index = new_context->type;
907         while (true) {
908                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
909                                           index - 1);
910                 BUG_ON(!type);
911 
912                 /* not bounded anymore */
913                 rc = -EPERM;
914                 if (!type->bounds)
915                         break;
916 
917                 /* @newsid is bounded by @oldsid */
918                 rc = 0;
919                 if (type->bounds == old_context->type)
920                         break;
921 
922                 index = type->bounds;
923         }
924 
925         if (rc) {
926                 char *old_name = NULL;
927                 char *new_name = NULL;
928                 u32 length;
929 
930                 if (!context_struct_to_string(old_context,
931                                               &old_name, &length) &&
932                     !context_struct_to_string(new_context,
933                                               &new_name, &length)) {
934                         audit_log(current->audit_context,
935                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
936                                   "op=security_bounded_transition "
937                                   "seresult=denied "
938                                   "oldcontext=%s newcontext=%s",
939                                   old_name, new_name);
940                 }
941                 kfree(new_name);
942                 kfree(old_name);
943         }
944 out:
945         read_unlock(&policy_rwlock);
946 
947         return rc;
948 }
949 
950 static void avd_init(struct av_decision *avd)
951 {
952         avd->allowed = 0;
953         avd->auditallow = 0;
954         avd->auditdeny = 0xffffffff;
955         avd->seqno = latest_granting;
956         avd->flags = 0;
957 }
958 
959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
960                                         struct avtab_node *node)
961 {
962         unsigned int i;
963 
964         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
965                 if (xpermd->driver != node->datum.u.xperms->driver)
966                         return;
967         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
968                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
969                                         xpermd->driver))
970                         return;
971         } else {
972                 BUG();
973         }
974 
975         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
976                 xpermd->used |= XPERMS_ALLOWED;
977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
978                         memset(xpermd->allowed->p, 0xff,
979                                         sizeof(xpermd->allowed->p));
980                 }
981                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
982                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
983                                 xpermd->allowed->p[i] |=
984                                         node->datum.u.xperms->perms.p[i];
985                 }
986         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
987                 xpermd->used |= XPERMS_AUDITALLOW;
988                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
989                         memset(xpermd->auditallow->p, 0xff,
990                                         sizeof(xpermd->auditallow->p));
991                 }
992                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
993                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
994                                 xpermd->auditallow->p[i] |=
995                                         node->datum.u.xperms->perms.p[i];
996                 }
997         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
998                 xpermd->used |= XPERMS_DONTAUDIT;
999                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1000                         memset(xpermd->dontaudit->p, 0xff,
1001                                         sizeof(xpermd->dontaudit->p));
1002                 }
1003                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1004                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1005                                 xpermd->dontaudit->p[i] |=
1006                                         node->datum.u.xperms->perms.p[i];
1007                 }
1008         } else {
1009                 BUG();
1010         }
1011 }
1012 
1013 void security_compute_xperms_decision(u32 ssid,
1014                                 u32 tsid,
1015                                 u16 orig_tclass,
1016                                 u8 driver,
1017                                 struct extended_perms_decision *xpermd)
1018 {
1019         u16 tclass;
1020         struct context *scontext, *tcontext;
1021         struct avtab_key avkey;
1022         struct avtab_node *node;
1023         struct ebitmap *sattr, *tattr;
1024         struct ebitmap_node *snode, *tnode;
1025         unsigned int i, j;
1026 
1027         xpermd->driver = driver;
1028         xpermd->used = 0;
1029         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1030         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1031         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1032 
1033         read_lock(&policy_rwlock);
1034         if (!ss_initialized)
1035                 goto allow;
1036 
1037         scontext = sidtab_search(&sidtab, ssid);
1038         if (!scontext) {
1039                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1040                        __func__, ssid);
1041                 goto out;
1042         }
1043 
1044         tcontext = sidtab_search(&sidtab, tsid);
1045         if (!tcontext) {
1046                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1047                        __func__, tsid);
1048                 goto out;
1049         }
1050 
1051         tclass = unmap_class(orig_tclass);
1052         if (unlikely(orig_tclass && !tclass)) {
1053                 if (policydb.allow_unknown)
1054                         goto allow;
1055                 goto out;
1056         }
1057 
1058 
1059         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1060                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1061                 goto out;
1062         }
1063 
1064         avkey.target_class = tclass;
1065         avkey.specified = AVTAB_XPERMS;
1066         sattr = flex_array_get(policydb.type_attr_map_array,
1067                                 scontext->type - 1);
1068         BUG_ON(!sattr);
1069         tattr = flex_array_get(policydb.type_attr_map_array,
1070                                 tcontext->type - 1);
1071         BUG_ON(!tattr);
1072         ebitmap_for_each_positive_bit(sattr, snode, i) {
1073                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1074                         avkey.source_type = i + 1;
1075                         avkey.target_type = j + 1;
1076                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1077                              node;
1078                              node = avtab_search_node_next(node, avkey.specified))
1079                                 services_compute_xperms_decision(xpermd, node);
1080 
1081                         cond_compute_xperms(&policydb.te_cond_avtab,
1082                                                 &avkey, xpermd);
1083                 }
1084         }
1085 out:
1086         read_unlock(&policy_rwlock);
1087         return;
1088 allow:
1089         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1090         goto out;
1091 }
1092 
1093 /**
1094  * security_compute_av - Compute access vector decisions.
1095  * @ssid: source security identifier
1096  * @tsid: target security identifier
1097  * @tclass: target security class
1098  * @avd: access vector decisions
1099  * @xperms: extended permissions
1100  *
1101  * Compute a set of access vector decisions based on the
1102  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1103  */
1104 void security_compute_av(u32 ssid,
1105                          u32 tsid,
1106                          u16 orig_tclass,
1107                          struct av_decision *avd,
1108                          struct extended_perms *xperms)
1109 {
1110         u16 tclass;
1111         struct context *scontext = NULL, *tcontext = NULL;
1112 
1113         read_lock(&policy_rwlock);
1114         avd_init(avd);
1115         xperms->len = 0;
1116         if (!ss_initialized)
1117                 goto allow;
1118 
1119         scontext = sidtab_search(&sidtab, ssid);
1120         if (!scontext) {
1121                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1122                        __func__, ssid);
1123                 goto out;
1124         }
1125 
1126         /* permissive domain? */
1127         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1128                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1129 
1130         tcontext = sidtab_search(&sidtab, tsid);
1131         if (!tcontext) {
1132                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1133                        __func__, tsid);
1134                 goto out;
1135         }
1136 
1137         tclass = unmap_class(orig_tclass);
1138         if (unlikely(orig_tclass && !tclass)) {
1139                 if (policydb.allow_unknown)
1140                         goto allow;
1141                 goto out;
1142         }
1143         context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1144         map_decision(orig_tclass, avd, policydb.allow_unknown);
1145 out:
1146         read_unlock(&policy_rwlock);
1147         return;
1148 allow:
1149         avd->allowed = 0xffffffff;
1150         goto out;
1151 }
1152 
1153 void security_compute_av_user(u32 ssid,
1154                               u32 tsid,
1155                               u16 tclass,
1156                               struct av_decision *avd)
1157 {
1158         struct context *scontext = NULL, *tcontext = NULL;
1159 
1160         read_lock(&policy_rwlock);
1161         avd_init(avd);
1162         if (!ss_initialized)
1163                 goto allow;
1164 
1165         scontext = sidtab_search(&sidtab, ssid);
1166         if (!scontext) {
1167                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1168                        __func__, ssid);
1169                 goto out;
1170         }
1171 
1172         /* permissive domain? */
1173         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1174                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1175 
1176         tcontext = sidtab_search(&sidtab, tsid);
1177         if (!tcontext) {
1178                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1179                        __func__, tsid);
1180                 goto out;
1181         }
1182 
1183         if (unlikely(!tclass)) {
1184                 if (policydb.allow_unknown)
1185                         goto allow;
1186                 goto out;
1187         }
1188 
1189         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1190  out:
1191         read_unlock(&policy_rwlock);
1192         return;
1193 allow:
1194         avd->allowed = 0xffffffff;
1195         goto out;
1196 }
1197 
1198 /*
1199  * Write the security context string representation of
1200  * the context structure `context' into a dynamically
1201  * allocated string of the correct size.  Set `*scontext'
1202  * to point to this string and set `*scontext_len' to
1203  * the length of the string.
1204  */
1205 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1206 {
1207         char *scontextp;
1208 
1209         if (scontext)
1210                 *scontext = NULL;
1211         *scontext_len = 0;
1212 
1213         if (context->len) {
1214                 *scontext_len = context->len;
1215                 if (scontext) {
1216                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1217                         if (!(*scontext))
1218                                 return -ENOMEM;
1219                 }
1220                 return 0;
1221         }
1222 
1223         /* Compute the size of the context. */
1224         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1225         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1226         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1227         *scontext_len += mls_compute_context_len(context);
1228 
1229         if (!scontext)
1230                 return 0;
1231 
1232         /* Allocate space for the context; caller must free this space. */
1233         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1234         if (!scontextp)
1235                 return -ENOMEM;
1236         *scontext = scontextp;
1237 
1238         /*
1239          * Copy the user name, role name and type name into the context.
1240          */
1241         scontextp += sprintf(scontextp, "%s:%s:%s",
1242                 sym_name(&policydb, SYM_USERS, context->user - 1),
1243                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1244                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1245 
1246         mls_sid_to_context(context, &scontextp);
1247 
1248         *scontextp = 0;
1249 
1250         return 0;
1251 }
1252 
1253 #include "initial_sid_to_string.h"
1254 
1255 const char *security_get_initial_sid_context(u32 sid)
1256 {
1257         if (unlikely(sid > SECINITSID_NUM))
1258                 return NULL;
1259         return initial_sid_to_string[sid];
1260 }
1261 
1262 static int security_sid_to_context_core(u32 sid, char **scontext,
1263                                         u32 *scontext_len, int force)
1264 {
1265         struct context *context;
1266         int rc = 0;
1267 
1268         if (scontext)
1269                 *scontext = NULL;
1270         *scontext_len  = 0;
1271 
1272         if (!ss_initialized) {
1273                 if (sid <= SECINITSID_NUM) {
1274                         char *scontextp;
1275 
1276                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1277                         if (!scontext)
1278                                 goto out;
1279                         scontextp = kmemdup(initial_sid_to_string[sid],
1280                                             *scontext_len, GFP_ATOMIC);
1281                         if (!scontextp) {
1282                                 rc = -ENOMEM;
1283                                 goto out;
1284                         }
1285                         *scontext = scontextp;
1286                         goto out;
1287                 }
1288                 printk(KERN_ERR "SELinux: %s:  called before initial "
1289                        "load_policy on unknown SID %d\n", __func__, sid);
1290                 rc = -EINVAL;
1291                 goto out;
1292         }
1293         read_lock(&policy_rwlock);
1294         if (force)
1295                 context = sidtab_search_force(&sidtab, sid);
1296         else
1297                 context = sidtab_search(&sidtab, sid);
1298         if (!context) {
1299                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1300                         __func__, sid);
1301                 rc = -EINVAL;
1302                 goto out_unlock;
1303         }
1304         rc = context_struct_to_string(context, scontext, scontext_len);
1305 out_unlock:
1306         read_unlock(&policy_rwlock);
1307 out:
1308         return rc;
1309 
1310 }
1311 
1312 /**
1313  * security_sid_to_context - Obtain a context for a given SID.
1314  * @sid: security identifier, SID
1315  * @scontext: security context
1316  * @scontext_len: length in bytes
1317  *
1318  * Write the string representation of the context associated with @sid
1319  * into a dynamically allocated string of the correct size.  Set @scontext
1320  * to point to this string and set @scontext_len to the length of the string.
1321  */
1322 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1323 {
1324         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1325 }
1326 
1327 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1328 {
1329         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1330 }
1331 
1332 /*
1333  * Caveat:  Mutates scontext.
1334  */
1335 static int string_to_context_struct(struct policydb *pol,
1336                                     struct sidtab *sidtabp,
1337                                     char *scontext,
1338                                     u32 scontext_len,
1339                                     struct context *ctx,
1340                                     u32 def_sid)
1341 {
1342         struct role_datum *role;
1343         struct type_datum *typdatum;
1344         struct user_datum *usrdatum;
1345         char *scontextp, *p, oldc;
1346         int rc = 0;
1347 
1348         context_init(ctx);
1349 
1350         /* Parse the security context. */
1351 
1352         rc = -EINVAL;
1353         scontextp = (char *) scontext;
1354 
1355         /* Extract the user. */
1356         p = scontextp;
1357         while (*p && *p != ':')
1358                 p++;
1359 
1360         if (*p == 0)
1361                 goto out;
1362 
1363         *p++ = 0;
1364 
1365         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1366         if (!usrdatum)
1367                 goto out;
1368 
1369         ctx->user = usrdatum->value;
1370 
1371         /* Extract role. */
1372         scontextp = p;
1373         while (*p && *p != ':')
1374                 p++;
1375 
1376         if (*p == 0)
1377                 goto out;
1378 
1379         *p++ = 0;
1380 
1381         role = hashtab_search(pol->p_roles.table, scontextp);
1382         if (!role)
1383                 goto out;
1384         ctx->role = role->value;
1385 
1386         /* Extract type. */
1387         scontextp = p;
1388         while (*p && *p != ':')
1389                 p++;
1390         oldc = *p;
1391         *p++ = 0;
1392 
1393         typdatum = hashtab_search(pol->p_types.table, scontextp);
1394         if (!typdatum || typdatum->attribute)
1395                 goto out;
1396 
1397         ctx->type = typdatum->value;
1398 
1399         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1400         if (rc)
1401                 goto out;
1402 
1403         rc = -EINVAL;
1404         if ((p - scontext) < scontext_len)
1405                 goto out;
1406 
1407         /* Check the validity of the new context. */
1408         if (!policydb_context_isvalid(pol, ctx))
1409                 goto out;
1410         rc = 0;
1411 out:
1412         if (rc)
1413                 context_destroy(ctx);
1414         return rc;
1415 }
1416 
1417 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1418                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1419                                         int force)
1420 {
1421         char *scontext2, *str = NULL;
1422         struct context context;
1423         int rc = 0;
1424 
1425         /* An empty security context is never valid. */
1426         if (!scontext_len)
1427                 return -EINVAL;
1428 
1429         if (!ss_initialized) {
1430                 int i;
1431 
1432                 for (i = 1; i < SECINITSID_NUM; i++) {
1433                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1434                                 *sid = i;
1435                                 return 0;
1436                         }
1437                 }
1438                 *sid = SECINITSID_KERNEL;
1439                 return 0;
1440         }
1441         *sid = SECSID_NULL;
1442 
1443         /* Copy the string so that we can modify the copy as we parse it. */
1444         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1445         if (!scontext2)
1446                 return -ENOMEM;
1447         memcpy(scontext2, scontext, scontext_len);
1448         scontext2[scontext_len] = 0;
1449 
1450         if (force) {
1451                 /* Save another copy for storing in uninterpreted form */
1452                 rc = -ENOMEM;
1453                 str = kstrdup(scontext2, gfp_flags);
1454                 if (!str)
1455                         goto out;
1456         }
1457 
1458         read_lock(&policy_rwlock);
1459         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1460                                       scontext_len, &context, def_sid);
1461         if (rc == -EINVAL && force) {
1462                 context.str = str;
1463                 context.len = scontext_len;
1464                 str = NULL;
1465         } else if (rc)
1466                 goto out_unlock;
1467         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1468         context_destroy(&context);
1469 out_unlock:
1470         read_unlock(&policy_rwlock);
1471 out:
1472         kfree(scontext2);
1473         kfree(str);
1474         return rc;
1475 }
1476 
1477 /**
1478  * security_context_to_sid - Obtain a SID for a given security context.
1479  * @scontext: security context
1480  * @scontext_len: length in bytes
1481  * @sid: security identifier, SID
1482  * @gfp: context for the allocation
1483  *
1484  * Obtains a SID associated with the security context that
1485  * has the string representation specified by @scontext.
1486  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1487  * memory is available, or 0 on success.
1488  */
1489 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1490                             gfp_t gfp)
1491 {
1492         return security_context_to_sid_core(scontext, scontext_len,
1493                                             sid, SECSID_NULL, gfp, 0);
1494 }
1495 
1496 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1497 {
1498         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1499 }
1500 
1501 /**
1502  * security_context_to_sid_default - Obtain a SID for a given security context,
1503  * falling back to specified default if needed.
1504  *
1505  * @scontext: security context
1506  * @scontext_len: length in bytes
1507  * @sid: security identifier, SID
1508  * @def_sid: default SID to assign on error
1509  *
1510  * Obtains a SID associated with the security context that
1511  * has the string representation specified by @scontext.
1512  * The default SID is passed to the MLS layer to be used to allow
1513  * kernel labeling of the MLS field if the MLS field is not present
1514  * (for upgrading to MLS without full relabel).
1515  * Implicitly forces adding of the context even if it cannot be mapped yet.
1516  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1517  * memory is available, or 0 on success.
1518  */
1519 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1520                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1521 {
1522         return security_context_to_sid_core(scontext, scontext_len,
1523                                             sid, def_sid, gfp_flags, 1);
1524 }
1525 
1526 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1527                                   u32 *sid)
1528 {
1529         return security_context_to_sid_core(scontext, scontext_len,
1530                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1531 }
1532 
1533 static int compute_sid_handle_invalid_context(
1534         struct context *scontext,
1535         struct context *tcontext,
1536         u16 tclass,
1537         struct context *newcontext)
1538 {
1539         char *s = NULL, *t = NULL, *n = NULL;
1540         u32 slen, tlen, nlen;
1541 
1542         if (context_struct_to_string(scontext, &s, &slen))
1543                 goto out;
1544         if (context_struct_to_string(tcontext, &t, &tlen))
1545                 goto out;
1546         if (context_struct_to_string(newcontext, &n, &nlen))
1547                 goto out;
1548         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1549                   "op=security_compute_sid invalid_context=%s"
1550                   " scontext=%s"
1551                   " tcontext=%s"
1552                   " tclass=%s",
1553                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1554 out:
1555         kfree(s);
1556         kfree(t);
1557         kfree(n);
1558         if (!selinux_enforcing)
1559                 return 0;
1560         return -EACCES;
1561 }
1562 
1563 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1564                                   u32 stype, u32 ttype, u16 tclass,
1565                                   const char *objname)
1566 {
1567         struct filename_trans ft;
1568         struct filename_trans_datum *otype;
1569 
1570         /*
1571          * Most filename trans rules are going to live in specific directories
1572          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1573          * if the ttype does not contain any rules.
1574          */
1575         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1576                 return;
1577 
1578         ft.stype = stype;
1579         ft.ttype = ttype;
1580         ft.tclass = tclass;
1581         ft.name = objname;
1582 
1583         otype = hashtab_search(p->filename_trans, &ft);
1584         if (otype)
1585                 newcontext->type = otype->otype;
1586 }
1587 
1588 static int security_compute_sid(u32 ssid,
1589                                 u32 tsid,
1590                                 u16 orig_tclass,
1591                                 u32 specified,
1592                                 const char *objname,
1593                                 u32 *out_sid,
1594                                 bool kern)
1595 {
1596         struct class_datum *cladatum = NULL;
1597         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1598         struct role_trans *roletr = NULL;
1599         struct avtab_key avkey;
1600         struct avtab_datum *avdatum;
1601         struct avtab_node *node;
1602         u16 tclass;
1603         int rc = 0;
1604         bool sock;
1605 
1606         if (!ss_initialized) {
1607                 switch (orig_tclass) {
1608                 case SECCLASS_PROCESS: /* kernel value */
1609                         *out_sid = ssid;
1610                         break;
1611                 default:
1612                         *out_sid = tsid;
1613                         break;
1614                 }
1615                 goto out;
1616         }
1617 
1618         context_init(&newcontext);
1619 
1620         read_lock(&policy_rwlock);
1621 
1622         if (kern) {
1623                 tclass = unmap_class(orig_tclass);
1624                 sock = security_is_socket_class(orig_tclass);
1625         } else {
1626                 tclass = orig_tclass;
1627                 sock = security_is_socket_class(map_class(tclass));
1628         }
1629 
1630         scontext = sidtab_search(&sidtab, ssid);
1631         if (!scontext) {
1632                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1633                        __func__, ssid);
1634                 rc = -EINVAL;
1635                 goto out_unlock;
1636         }
1637         tcontext = sidtab_search(&sidtab, tsid);
1638         if (!tcontext) {
1639                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1640                        __func__, tsid);
1641                 rc = -EINVAL;
1642                 goto out_unlock;
1643         }
1644 
1645         if (tclass && tclass <= policydb.p_classes.nprim)
1646                 cladatum = policydb.class_val_to_struct[tclass - 1];
1647 
1648         /* Set the user identity. */
1649         switch (specified) {
1650         case AVTAB_TRANSITION:
1651         case AVTAB_CHANGE:
1652                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1653                         newcontext.user = tcontext->user;
1654                 } else {
1655                         /* notice this gets both DEFAULT_SOURCE and unset */
1656                         /* Use the process user identity. */
1657                         newcontext.user = scontext->user;
1658                 }
1659                 break;
1660         case AVTAB_MEMBER:
1661                 /* Use the related object owner. */
1662                 newcontext.user = tcontext->user;
1663                 break;
1664         }
1665 
1666         /* Set the role to default values. */
1667         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1668                 newcontext.role = scontext->role;
1669         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1670                 newcontext.role = tcontext->role;
1671         } else {
1672                 if ((tclass == policydb.process_class) || (sock == true))
1673                         newcontext.role = scontext->role;
1674                 else
1675                         newcontext.role = OBJECT_R_VAL;
1676         }
1677 
1678         /* Set the type to default values. */
1679         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1680                 newcontext.type = scontext->type;
1681         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1682                 newcontext.type = tcontext->type;
1683         } else {
1684                 if ((tclass == policydb.process_class) || (sock == true)) {
1685                         /* Use the type of process. */
1686                         newcontext.type = scontext->type;
1687                 } else {
1688                         /* Use the type of the related object. */
1689                         newcontext.type = tcontext->type;
1690                 }
1691         }
1692 
1693         /* Look for a type transition/member/change rule. */
1694         avkey.source_type = scontext->type;
1695         avkey.target_type = tcontext->type;
1696         avkey.target_class = tclass;
1697         avkey.specified = specified;
1698         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1699 
1700         /* If no permanent rule, also check for enabled conditional rules */
1701         if (!avdatum) {
1702                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1703                 for (; node; node = avtab_search_node_next(node, specified)) {
1704                         if (node->key.specified & AVTAB_ENABLED) {
1705                                 avdatum = &node->datum;
1706                                 break;
1707                         }
1708                 }
1709         }
1710 
1711         if (avdatum) {
1712                 /* Use the type from the type transition/member/change rule. */
1713                 newcontext.type = avdatum->u.data;
1714         }
1715 
1716         /* if we have a objname this is a file trans check so check those rules */
1717         if (objname)
1718                 filename_compute_type(&policydb, &newcontext, scontext->type,
1719                                       tcontext->type, tclass, objname);
1720 
1721         /* Check for class-specific changes. */
1722         if (specified & AVTAB_TRANSITION) {
1723                 /* Look for a role transition rule. */
1724                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1725                         if ((roletr->role == scontext->role) &&
1726                             (roletr->type == tcontext->type) &&
1727                             (roletr->tclass == tclass)) {
1728                                 /* Use the role transition rule. */
1729                                 newcontext.role = roletr->new_role;
1730                                 break;
1731                         }
1732                 }
1733         }
1734 
1735         /* Set the MLS attributes.
1736            This is done last because it may allocate memory. */
1737         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1738                              &newcontext, sock);
1739         if (rc)
1740                 goto out_unlock;
1741 
1742         /* Check the validity of the context. */
1743         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1744                 rc = compute_sid_handle_invalid_context(scontext,
1745                                                         tcontext,
1746                                                         tclass,
1747                                                         &newcontext);
1748                 if (rc)
1749                         goto out_unlock;
1750         }
1751         /* Obtain the sid for the context. */
1752         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1753 out_unlock:
1754         read_unlock(&policy_rwlock);
1755         context_destroy(&newcontext);
1756 out:
1757         return rc;
1758 }
1759 
1760 /**
1761  * security_transition_sid - Compute the SID for a new subject/object.
1762  * @ssid: source security identifier
1763  * @tsid: target security identifier
1764  * @tclass: target security class
1765  * @out_sid: security identifier for new subject/object
1766  *
1767  * Compute a SID to use for labeling a new subject or object in the
1768  * class @tclass based on a SID pair (@ssid, @tsid).
1769  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1770  * if insufficient memory is available, or %0 if the new SID was
1771  * computed successfully.
1772  */
1773 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1774                             const struct qstr *qstr, u32 *out_sid)
1775 {
1776         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1777                                     qstr ? qstr->name : NULL, out_sid, true);
1778 }
1779 
1780 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1781                                  const char *objname, u32 *out_sid)
1782 {
1783         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1784                                     objname, out_sid, false);
1785 }
1786 
1787 /**
1788  * security_member_sid - Compute the SID for member selection.
1789  * @ssid: source security identifier
1790  * @tsid: target security identifier
1791  * @tclass: target security class
1792  * @out_sid: security identifier for selected member
1793  *
1794  * Compute a SID to use when selecting a member of a polyinstantiated
1795  * object of class @tclass based on a SID pair (@ssid, @tsid).
1796  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1797  * if insufficient memory is available, or %0 if the SID was
1798  * computed successfully.
1799  */
1800 int security_member_sid(u32 ssid,
1801                         u32 tsid,
1802                         u16 tclass,
1803                         u32 *out_sid)
1804 {
1805         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1806                                     out_sid, false);
1807 }
1808 
1809 /**
1810  * security_change_sid - Compute the SID for object relabeling.
1811  * @ssid: source security identifier
1812  * @tsid: target security identifier
1813  * @tclass: target security class
1814  * @out_sid: security identifier for selected member
1815  *
1816  * Compute a SID to use for relabeling an object of class @tclass
1817  * based on a SID pair (@ssid, @tsid).
1818  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1819  * if insufficient memory is available, or %0 if the SID was
1820  * computed successfully.
1821  */
1822 int security_change_sid(u32 ssid,
1823                         u32 tsid,
1824                         u16 tclass,
1825                         u32 *out_sid)
1826 {
1827         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1828                                     out_sid, false);
1829 }
1830 
1831 /* Clone the SID into the new SID table. */
1832 static int clone_sid(u32 sid,
1833                      struct context *context,
1834                      void *arg)
1835 {
1836         struct sidtab *s = arg;
1837 
1838         if (sid > SECINITSID_NUM)
1839                 return sidtab_insert(s, sid, context);
1840         else
1841                 return 0;
1842 }
1843 
1844 static inline int convert_context_handle_invalid_context(struct context *context)
1845 {
1846         char *s;
1847         u32 len;
1848 
1849         if (selinux_enforcing)
1850                 return -EINVAL;
1851 
1852         if (!context_struct_to_string(context, &s, &len)) {
1853                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1854                 kfree(s);
1855         }
1856         return 0;
1857 }
1858 
1859 struct convert_context_args {
1860         struct policydb *oldp;
1861         struct policydb *newp;
1862 };
1863 
1864 /*
1865  * Convert the values in the security context
1866  * structure `c' from the values specified
1867  * in the policy `p->oldp' to the values specified
1868  * in the policy `p->newp'.  Verify that the
1869  * context is valid under the new policy.
1870  */
1871 static int convert_context(u32 key,
1872                            struct context *c,
1873                            void *p)
1874 {
1875         struct convert_context_args *args;
1876         struct context oldc;
1877         struct ocontext *oc;
1878         struct mls_range *range;
1879         struct role_datum *role;
1880         struct type_datum *typdatum;
1881         struct user_datum *usrdatum;
1882         char *s;
1883         u32 len;
1884         int rc = 0;
1885 
1886         if (key <= SECINITSID_NUM)
1887                 goto out;
1888 
1889         args = p;
1890 
1891         if (c->str) {
1892                 struct context ctx;
1893 
1894                 rc = -ENOMEM;
1895                 s = kstrdup(c->str, GFP_KERNEL);
1896                 if (!s)
1897                         goto out;
1898 
1899                 rc = string_to_context_struct(args->newp, NULL, s,
1900                                               c->len, &ctx, SECSID_NULL);
1901                 kfree(s);
1902                 if (!rc) {
1903                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1904                                c->str);
1905                         /* Replace string with mapped representation. */
1906                         kfree(c->str);
1907                         memcpy(c, &ctx, sizeof(*c));
1908                         goto out;
1909                 } else if (rc == -EINVAL) {
1910                         /* Retain string representation for later mapping. */
1911                         rc = 0;
1912                         goto out;
1913                 } else {
1914                         /* Other error condition, e.g. ENOMEM. */
1915                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1916                                c->str, -rc);
1917                         goto out;
1918                 }
1919         }
1920 
1921         rc = context_cpy(&oldc, c);
1922         if (rc)
1923                 goto out;
1924 
1925         /* Convert the user. */
1926         rc = -EINVAL;
1927         usrdatum = hashtab_search(args->newp->p_users.table,
1928                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1929         if (!usrdatum)
1930                 goto bad;
1931         c->user = usrdatum->value;
1932 
1933         /* Convert the role. */
1934         rc = -EINVAL;
1935         role = hashtab_search(args->newp->p_roles.table,
1936                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1937         if (!role)
1938                 goto bad;
1939         c->role = role->value;
1940 
1941         /* Convert the type. */
1942         rc = -EINVAL;
1943         typdatum = hashtab_search(args->newp->p_types.table,
1944                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1945         if (!typdatum)
1946                 goto bad;
1947         c->type = typdatum->value;
1948 
1949         /* Convert the MLS fields if dealing with MLS policies */
1950         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1951                 rc = mls_convert_context(args->oldp, args->newp, c);
1952                 if (rc)
1953                         goto bad;
1954         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1955                 /*
1956                  * Switching between MLS and non-MLS policy:
1957                  * free any storage used by the MLS fields in the
1958                  * context for all existing entries in the sidtab.
1959                  */
1960                 mls_context_destroy(c);
1961         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1962                 /*
1963                  * Switching between non-MLS and MLS policy:
1964                  * ensure that the MLS fields of the context for all
1965                  * existing entries in the sidtab are filled in with a
1966                  * suitable default value, likely taken from one of the
1967                  * initial SIDs.
1968                  */
1969                 oc = args->newp->ocontexts[OCON_ISID];
1970                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1971                         oc = oc->next;
1972                 rc = -EINVAL;
1973                 if (!oc) {
1974                         printk(KERN_ERR "SELinux:  unable to look up"
1975                                 " the initial SIDs list\n");
1976                         goto bad;
1977                 }
1978                 range = &oc->context[0].range;
1979                 rc = mls_range_set(c, range);
1980                 if (rc)
1981                         goto bad;
1982         }
1983 
1984         /* Check the validity of the new context. */
1985         if (!policydb_context_isvalid(args->newp, c)) {
1986                 rc = convert_context_handle_invalid_context(&oldc);
1987                 if (rc)
1988                         goto bad;
1989         }
1990 
1991         context_destroy(&oldc);
1992 
1993         rc = 0;
1994 out:
1995         return rc;
1996 bad:
1997         /* Map old representation to string and save it. */
1998         rc = context_struct_to_string(&oldc, &s, &len);
1999         if (rc)
2000                 return rc;
2001         context_destroy(&oldc);
2002         context_destroy(c);
2003         c->str = s;
2004         c->len = len;
2005         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
2006                c->str);
2007         rc = 0;
2008         goto out;
2009 }
2010 
2011 static void security_load_policycaps(void)
2012 {
2013         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
2014                                                   POLICYDB_CAPABILITY_NETPEER);
2015         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
2016                                                   POLICYDB_CAPABILITY_OPENPERM);
2017         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
2018                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
2019 }
2020 
2021 static int security_preserve_bools(struct policydb *p);
2022 
2023 /**
2024  * security_load_policy - Load a security policy configuration.
2025  * @data: binary policy data
2026  * @len: length of data in bytes
2027  *
2028  * Load a new set of security policy configuration data,
2029  * validate it and convert the SID table as necessary.
2030  * This function will flush the access vector cache after
2031  * loading the new policy.
2032  */
2033 int security_load_policy(void *data, size_t len)
2034 {
2035         struct policydb *oldpolicydb, *newpolicydb;
2036         struct sidtab oldsidtab, newsidtab;
2037         struct selinux_mapping *oldmap, *map = NULL;
2038         struct convert_context_args args;
2039         u32 seqno;
2040         u16 map_size;
2041         int rc = 0;
2042         struct policy_file file = { data, len }, *fp = &file;
2043 
2044         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2045         if (!oldpolicydb) {
2046                 rc = -ENOMEM;
2047                 goto out;
2048         }
2049         newpolicydb = oldpolicydb + 1;
2050 
2051         if (!ss_initialized) {
2052                 avtab_cache_init();
2053                 rc = policydb_read(&policydb, fp);
2054                 if (rc) {
2055                         avtab_cache_destroy();
2056                         goto out;
2057                 }
2058 
2059                 policydb.len = len;
2060                 rc = selinux_set_mapping(&policydb, secclass_map,
2061                                          &current_mapping,
2062                                          &current_mapping_size);
2063                 if (rc) {
2064                         policydb_destroy(&policydb);
2065                         avtab_cache_destroy();
2066                         goto out;
2067                 }
2068 
2069                 rc = policydb_load_isids(&policydb, &sidtab);
2070                 if (rc) {
2071                         policydb_destroy(&policydb);
2072                         avtab_cache_destroy();
2073                         goto out;
2074                 }
2075 
2076                 security_load_policycaps();
2077                 ss_initialized = 1;
2078                 seqno = ++latest_granting;
2079                 selinux_complete_init();
2080                 avc_ss_reset(seqno);
2081                 selnl_notify_policyload(seqno);
2082                 selinux_status_update_policyload(seqno);
2083                 selinux_netlbl_cache_invalidate();
2084                 selinux_xfrm_notify_policyload();
2085                 goto out;
2086         }
2087 
2088 #if 0
2089         sidtab_hash_eval(&sidtab, "sids");
2090 #endif
2091 
2092         rc = policydb_read(newpolicydb, fp);
2093         if (rc)
2094                 goto out;
2095 
2096         newpolicydb->len = len;
2097         /* If switching between different policy types, log MLS status */
2098         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2099                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2100         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2101                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2102 
2103         rc = policydb_load_isids(newpolicydb, &newsidtab);
2104         if (rc) {
2105                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2106                 policydb_destroy(newpolicydb);
2107                 goto out;
2108         }
2109 
2110         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2111         if (rc)
2112                 goto err;
2113 
2114         rc = security_preserve_bools(newpolicydb);
2115         if (rc) {
2116                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2117                 goto err;
2118         }
2119 
2120         /* Clone the SID table. */
2121         sidtab_shutdown(&sidtab);
2122 
2123         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2124         if (rc)
2125                 goto err;
2126 
2127         /*
2128          * Convert the internal representations of contexts
2129          * in the new SID table.
2130          */
2131         args.oldp = &policydb;
2132         args.newp = newpolicydb;
2133         rc = sidtab_map(&newsidtab, convert_context, &args);
2134         if (rc) {
2135                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2136                         " representation of contexts in the new SID"
2137                         " table\n");
2138                 goto err;
2139         }
2140 
2141         /* Save the old policydb and SID table to free later. */
2142         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2143         sidtab_set(&oldsidtab, &sidtab);
2144 
2145         /* Install the new policydb and SID table. */
2146         write_lock_irq(&policy_rwlock);
2147         memcpy(&policydb, newpolicydb, sizeof(policydb));
2148         sidtab_set(&sidtab, &newsidtab);
2149         security_load_policycaps();
2150         oldmap = current_mapping;
2151         current_mapping = map;
2152         current_mapping_size = map_size;
2153         seqno = ++latest_granting;
2154         write_unlock_irq(&policy_rwlock);
2155 
2156         /* Free the old policydb and SID table. */
2157         policydb_destroy(oldpolicydb);
2158         sidtab_destroy(&oldsidtab);
2159         kfree(oldmap);
2160 
2161         avc_ss_reset(seqno);
2162         selnl_notify_policyload(seqno);
2163         selinux_status_update_policyload(seqno);
2164         selinux_netlbl_cache_invalidate();
2165         selinux_xfrm_notify_policyload();
2166 
2167         rc = 0;
2168         goto out;
2169 
2170 err:
2171         kfree(map);
2172         sidtab_destroy(&newsidtab);
2173         policydb_destroy(newpolicydb);
2174 
2175 out:
2176         kfree(oldpolicydb);
2177         return rc;
2178 }
2179 
2180 size_t security_policydb_len(void)
2181 {
2182         size_t len;
2183 
2184         read_lock(&policy_rwlock);
2185         len = policydb.len;
2186         read_unlock(&policy_rwlock);
2187 
2188         return len;
2189 }
2190 
2191 /**
2192  * security_port_sid - Obtain the SID for a port.
2193  * @protocol: protocol number
2194  * @port: port number
2195  * @out_sid: security identifier
2196  */
2197 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2198 {
2199         struct ocontext *c;
2200         int rc = 0;
2201 
2202         read_lock(&policy_rwlock);
2203 
2204         c = policydb.ocontexts[OCON_PORT];
2205         while (c) {
2206                 if (c->u.port.protocol == protocol &&
2207                     c->u.port.low_port <= port &&
2208                     c->u.port.high_port >= port)
2209                         break;
2210                 c = c->next;
2211         }
2212 
2213         if (c) {
2214                 if (!c->sid[0]) {
2215                         rc = sidtab_context_to_sid(&sidtab,
2216                                                    &c->context[0],
2217                                                    &c->sid[0]);
2218                         if (rc)
2219                                 goto out;
2220                 }
2221                 *out_sid = c->sid[0];
2222         } else {
2223                 *out_sid = SECINITSID_PORT;
2224         }
2225 
2226 out:
2227         read_unlock(&policy_rwlock);
2228         return rc;
2229 }
2230 
2231 /**
2232  * security_netif_sid - Obtain the SID for a network interface.
2233  * @name: interface name
2234  * @if_sid: interface SID
2235  */
2236 int security_netif_sid(char *name, u32 *if_sid)
2237 {
2238         int rc = 0;
2239         struct ocontext *c;
2240 
2241         read_lock(&policy_rwlock);
2242 
2243         c = policydb.ocontexts[OCON_NETIF];
2244         while (c) {
2245                 if (strcmp(name, c->u.name) == 0)
2246                         break;
2247                 c = c->next;
2248         }
2249 
2250         if (c) {
2251                 if (!c->sid[0] || !c->sid[1]) {
2252                         rc = sidtab_context_to_sid(&sidtab,
2253                                                   &c->context[0],
2254                                                   &c->sid[0]);
2255                         if (rc)
2256                                 goto out;
2257                         rc = sidtab_context_to_sid(&sidtab,
2258                                                    &c->context[1],
2259                                                    &c->sid[1]);
2260                         if (rc)
2261                                 goto out;
2262                 }
2263                 *if_sid = c->sid[0];
2264         } else
2265                 *if_sid = SECINITSID_NETIF;
2266 
2267 out:
2268         read_unlock(&policy_rwlock);
2269         return rc;
2270 }
2271 
2272 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2273 {
2274         int i, fail = 0;
2275 
2276         for (i = 0; i < 4; i++)
2277                 if (addr[i] != (input[i] & mask[i])) {
2278                         fail = 1;
2279                         break;
2280                 }
2281 
2282         return !fail;
2283 }
2284 
2285 /**
2286  * security_node_sid - Obtain the SID for a node (host).
2287  * @domain: communication domain aka address family
2288  * @addrp: address
2289  * @addrlen: address length in bytes
2290  * @out_sid: security identifier
2291  */
2292 int security_node_sid(u16 domain,
2293                       void *addrp,
2294                       u32 addrlen,
2295                       u32 *out_sid)
2296 {
2297         int rc;
2298         struct ocontext *c;
2299 
2300         read_lock(&policy_rwlock);
2301 
2302         switch (domain) {
2303         case AF_INET: {
2304                 u32 addr;
2305 
2306                 rc = -EINVAL;
2307                 if (addrlen != sizeof(u32))
2308                         goto out;
2309 
2310                 addr = *((u32 *)addrp);
2311 
2312                 c = policydb.ocontexts[OCON_NODE];
2313                 while (c) {
2314                         if (c->u.node.addr == (addr & c->u.node.mask))
2315                                 break;
2316                         c = c->next;
2317                 }
2318                 break;
2319         }
2320 
2321         case AF_INET6:
2322                 rc = -EINVAL;
2323                 if (addrlen != sizeof(u64) * 2)
2324                         goto out;
2325                 c = policydb.ocontexts[OCON_NODE6];
2326                 while (c) {
2327                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2328                                                 c->u.node6.mask))
2329                                 break;
2330                         c = c->next;
2331                 }
2332                 break;
2333 
2334         default:
2335                 rc = 0;
2336                 *out_sid = SECINITSID_NODE;
2337                 goto out;
2338         }
2339 
2340         if (c) {
2341                 if (!c->sid[0]) {
2342                         rc = sidtab_context_to_sid(&sidtab,
2343                                                    &c->context[0],
2344                                                    &c->sid[0]);
2345                         if (rc)
2346                                 goto out;
2347                 }
2348                 *out_sid = c->sid[0];
2349         } else {
2350                 *out_sid = SECINITSID_NODE;
2351         }
2352 
2353         rc = 0;
2354 out:
2355         read_unlock(&policy_rwlock);
2356         return rc;
2357 }
2358 
2359 #define SIDS_NEL 25
2360 
2361 /**
2362  * security_get_user_sids - Obtain reachable SIDs for a user.
2363  * @fromsid: starting SID
2364  * @username: username
2365  * @sids: array of reachable SIDs for user
2366  * @nel: number of elements in @sids
2367  *
2368  * Generate the set of SIDs for legal security contexts
2369  * for a given user that can be reached by @fromsid.
2370  * Set *@sids to point to a dynamically allocated
2371  * array containing the set of SIDs.  Set *@nel to the
2372  * number of elements in the array.
2373  */
2374 
2375 int security_get_user_sids(u32 fromsid,
2376                            char *username,
2377                            u32 **sids,
2378                            u32 *nel)
2379 {
2380         struct context *fromcon, usercon;
2381         u32 *mysids = NULL, *mysids2, sid;
2382         u32 mynel = 0, maxnel = SIDS_NEL;
2383         struct user_datum *user;
2384         struct role_datum *role;
2385         struct ebitmap_node *rnode, *tnode;
2386         int rc = 0, i, j;
2387 
2388         *sids = NULL;
2389         *nel = 0;
2390 
2391         if (!ss_initialized)
2392                 goto out;
2393 
2394         read_lock(&policy_rwlock);
2395 
2396         context_init(&usercon);
2397 
2398         rc = -EINVAL;
2399         fromcon = sidtab_search(&sidtab, fromsid);
2400         if (!fromcon)
2401                 goto out_unlock;
2402 
2403         rc = -EINVAL;
2404         user = hashtab_search(policydb.p_users.table, username);
2405         if (!user)
2406                 goto out_unlock;
2407 
2408         usercon.user = user->value;
2409 
2410         rc = -ENOMEM;
2411         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2412         if (!mysids)
2413                 goto out_unlock;
2414 
2415         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2416                 role = policydb.role_val_to_struct[i];
2417                 usercon.role = i + 1;
2418                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2419                         usercon.type = j + 1;
2420 
2421                         if (mls_setup_user_range(fromcon, user, &usercon))
2422                                 continue;
2423 
2424                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2425                         if (rc)
2426                                 goto out_unlock;
2427                         if (mynel < maxnel) {
2428                                 mysids[mynel++] = sid;
2429                         } else {
2430                                 rc = -ENOMEM;
2431                                 maxnel += SIDS_NEL;
2432                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2433                                 if (!mysids2)
2434                                         goto out_unlock;
2435                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2436                                 kfree(mysids);
2437                                 mysids = mysids2;
2438                                 mysids[mynel++] = sid;
2439                         }
2440                 }
2441         }
2442         rc = 0;
2443 out_unlock:
2444         read_unlock(&policy_rwlock);
2445         if (rc || !mynel) {
2446                 kfree(mysids);
2447                 goto out;
2448         }
2449 
2450         rc = -ENOMEM;
2451         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2452         if (!mysids2) {
2453                 kfree(mysids);
2454                 goto out;
2455         }
2456         for (i = 0, j = 0; i < mynel; i++) {
2457                 struct av_decision dummy_avd;
2458                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2459                                           SECCLASS_PROCESS, /* kernel value */
2460                                           PROCESS__TRANSITION, AVC_STRICT,
2461                                           &dummy_avd);
2462                 if (!rc)
2463                         mysids2[j++] = mysids[i];
2464                 cond_resched();
2465         }
2466         rc = 0;
2467         kfree(mysids);
2468         *sids = mysids2;
2469         *nel = j;
2470 out:
2471         return rc;
2472 }
2473 
2474 /**
2475  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2476  * @fstype: filesystem type
2477  * @path: path from root of mount
2478  * @sclass: file security class
2479  * @sid: SID for path
2480  *
2481  * Obtain a SID to use for a file in a filesystem that
2482  * cannot support xattr or use a fixed labeling behavior like
2483  * transition SIDs or task SIDs.
2484  *
2485  * The caller must acquire the policy_rwlock before calling this function.
2486  */
2487 static inline int __security_genfs_sid(const char *fstype,
2488                                        char *path,
2489                                        u16 orig_sclass,
2490                                        u32 *sid)
2491 {
2492         int len;
2493         u16 sclass;
2494         struct genfs *genfs;
2495         struct ocontext *c;
2496         int rc, cmp = 0;
2497 
2498         while (path[0] == '/' && path[1] == '/')
2499                 path++;
2500 
2501         sclass = unmap_class(orig_sclass);
2502         *sid = SECINITSID_UNLABELED;
2503 
2504         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2505                 cmp = strcmp(fstype, genfs->fstype);
2506                 if (cmp <= 0)
2507                         break;
2508         }
2509 
2510         rc = -ENOENT;
2511         if (!genfs || cmp)
2512                 goto out;
2513 
2514         for (c = genfs->head; c; c = c->next) {
2515                 len = strlen(c->u.name);
2516                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2517                     (strncmp(c->u.name, path, len) == 0))
2518                         break;
2519         }
2520 
2521         rc = -ENOENT;
2522         if (!c)
2523                 goto out;
2524 
2525         if (!c->sid[0]) {
2526                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2527                 if (rc)
2528                         goto out;
2529         }
2530 
2531         *sid = c->sid[0];
2532         rc = 0;
2533 out:
2534         return rc;
2535 }
2536 
2537 /**
2538  * security_genfs_sid - Obtain a SID for a file in a filesystem
2539  * @fstype: filesystem type
2540  * @path: path from root of mount
2541  * @sclass: file security class
2542  * @sid: SID for path
2543  *
2544  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2545  * it afterward.
2546  */
2547 int security_genfs_sid(const char *fstype,
2548                        char *path,
2549                        u16 orig_sclass,
2550                        u32 *sid)
2551 {
2552         int retval;
2553 
2554         read_lock(&policy_rwlock);
2555         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2556         read_unlock(&policy_rwlock);
2557         return retval;
2558 }
2559 
2560 /**
2561  * security_fs_use - Determine how to handle labeling for a filesystem.
2562  * @sb: superblock in question
2563  */
2564 int security_fs_use(struct super_block *sb)
2565 {
2566         int rc = 0;
2567         struct ocontext *c;
2568         struct superblock_security_struct *sbsec = sb->s_security;
2569         const char *fstype = sb->s_type->name;
2570 
2571         read_lock(&policy_rwlock);
2572 
2573         c = policydb.ocontexts[OCON_FSUSE];
2574         while (c) {
2575                 if (strcmp(fstype, c->u.name) == 0)
2576                         break;
2577                 c = c->next;
2578         }
2579 
2580         if (c) {
2581                 sbsec->behavior = c->v.behavior;
2582                 if (!c->sid[0]) {
2583                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2584                                                    &c->sid[0]);
2585                         if (rc)
2586                                 goto out;
2587                 }
2588                 sbsec->sid = c->sid[0];
2589         } else {
2590                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2591                                           &sbsec->sid);
2592                 if (rc) {
2593                         sbsec->behavior = SECURITY_FS_USE_NONE;
2594                         rc = 0;
2595                 } else {
2596                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2597                 }
2598         }
2599 
2600 out:
2601         read_unlock(&policy_rwlock);
2602         return rc;
2603 }
2604 
2605 int security_get_bools(int *len, char ***names, int **values)
2606 {
2607         int i, rc;
2608 
2609         read_lock(&policy_rwlock);
2610         *names = NULL;
2611         *values = NULL;
2612 
2613         rc = 0;
2614         *len = policydb.p_bools.nprim;
2615         if (!*len)
2616                 goto out;
2617 
2618         rc = -ENOMEM;
2619         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2620         if (!*names)
2621                 goto err;
2622 
2623         rc = -ENOMEM;
2624         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2625         if (!*values)
2626                 goto err;
2627 
2628         for (i = 0; i < *len; i++) {
2629                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2630 
2631                 rc = -ENOMEM;
2632                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2633                 if (!(*names)[i])
2634                         goto err;
2635         }
2636         rc = 0;
2637 out:
2638         read_unlock(&policy_rwlock);
2639         return rc;
2640 err:
2641         if (*names) {
2642                 for (i = 0; i < *len; i++)
2643                         kfree((*names)[i]);
2644         }
2645         kfree(*values);
2646         goto out;
2647 }
2648 
2649 
2650 int security_set_bools(int len, int *values)
2651 {
2652         int i, rc;
2653         int lenp, seqno = 0;
2654         struct cond_node *cur;
2655 
2656         write_lock_irq(&policy_rwlock);
2657 
2658         rc = -EFAULT;
2659         lenp = policydb.p_bools.nprim;
2660         if (len != lenp)
2661                 goto out;
2662 
2663         for (i = 0; i < len; i++) {
2664                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2665                         audit_log(current->audit_context, GFP_ATOMIC,
2666                                 AUDIT_MAC_CONFIG_CHANGE,
2667                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2668                                 sym_name(&policydb, SYM_BOOLS, i),
2669                                 !!values[i],
2670                                 policydb.bool_val_to_struct[i]->state,
2671                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2672                                 audit_get_sessionid(current));
2673                 }
2674                 if (values[i])
2675                         policydb.bool_val_to_struct[i]->state = 1;
2676                 else
2677                         policydb.bool_val_to_struct[i]->state = 0;
2678         }
2679 
2680         for (cur = policydb.cond_list; cur; cur = cur->next) {
2681                 rc = evaluate_cond_node(&policydb, cur);
2682                 if (rc)
2683                         goto out;
2684         }
2685 
2686         seqno = ++latest_granting;
2687         rc = 0;
2688 out:
2689         write_unlock_irq(&policy_rwlock);
2690         if (!rc) {
2691                 avc_ss_reset(seqno);
2692                 selnl_notify_policyload(seqno);
2693                 selinux_status_update_policyload(seqno);
2694                 selinux_xfrm_notify_policyload();
2695         }
2696         return rc;
2697 }
2698 
2699 int security_get_bool_value(int bool)
2700 {
2701         int rc;
2702         int len;
2703 
2704         read_lock(&policy_rwlock);
2705 
2706         rc = -EFAULT;
2707         len = policydb.p_bools.nprim;
2708         if (bool >= len)
2709                 goto out;
2710 
2711         rc = policydb.bool_val_to_struct[bool]->state;
2712 out:
2713         read_unlock(&policy_rwlock);
2714         return rc;
2715 }
2716 
2717 static int security_preserve_bools(struct policydb *p)
2718 {
2719         int rc, nbools = 0, *bvalues = NULL, i;
2720         char **bnames = NULL;
2721         struct cond_bool_datum *booldatum;
2722         struct cond_node *cur;
2723 
2724         rc = security_get_bools(&nbools, &bnames, &bvalues);
2725         if (rc)
2726                 goto out;
2727         for (i = 0; i < nbools; i++) {
2728                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2729                 if (booldatum)
2730                         booldatum->state = bvalues[i];
2731         }
2732         for (cur = p->cond_list; cur; cur = cur->next) {
2733                 rc = evaluate_cond_node(p, cur);
2734                 if (rc)
2735                         goto out;
2736         }
2737 
2738 out:
2739         if (bnames) {
2740                 for (i = 0; i < nbools; i++)
2741                         kfree(bnames[i]);
2742         }
2743         kfree(bnames);
2744         kfree(bvalues);
2745         return rc;
2746 }
2747 
2748 /*
2749  * security_sid_mls_copy() - computes a new sid based on the given
2750  * sid and the mls portion of mls_sid.
2751  */
2752 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2753 {
2754         struct context *context1;
2755         struct context *context2;
2756         struct context newcon;
2757         char *s;
2758         u32 len;
2759         int rc;
2760 
2761         rc = 0;
2762         if (!ss_initialized || !policydb.mls_enabled) {
2763                 *new_sid = sid;
2764                 goto out;
2765         }
2766 
2767         context_init(&newcon);
2768 
2769         read_lock(&policy_rwlock);
2770 
2771         rc = -EINVAL;
2772         context1 = sidtab_search(&sidtab, sid);
2773         if (!context1) {
2774                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2775                         __func__, sid);
2776                 goto out_unlock;
2777         }
2778 
2779         rc = -EINVAL;
2780         context2 = sidtab_search(&sidtab, mls_sid);
2781         if (!context2) {
2782                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2783                         __func__, mls_sid);
2784                 goto out_unlock;
2785         }
2786 
2787         newcon.user = context1->user;
2788         newcon.role = context1->role;
2789         newcon.type = context1->type;
2790         rc = mls_context_cpy(&newcon, context2);
2791         if (rc)
2792                 goto out_unlock;
2793 
2794         /* Check the validity of the new context. */
2795         if (!policydb_context_isvalid(&policydb, &newcon)) {
2796                 rc = convert_context_handle_invalid_context(&newcon);
2797                 if (rc) {
2798                         if (!context_struct_to_string(&newcon, &s, &len)) {
2799                                 audit_log(current->audit_context,
2800                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2801                                           "op=security_sid_mls_copy "
2802                                           "invalid_context=%s", s);
2803                                 kfree(s);
2804                         }
2805                         goto out_unlock;
2806                 }
2807         }
2808 
2809         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2810 out_unlock:
2811         read_unlock(&policy_rwlock);
2812         context_destroy(&newcon);
2813 out:
2814         return rc;
2815 }
2816 
2817 /**
2818  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2819  * @nlbl_sid: NetLabel SID
2820  * @nlbl_type: NetLabel labeling protocol type
2821  * @xfrm_sid: XFRM SID
2822  *
2823  * Description:
2824  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2825  * resolved into a single SID it is returned via @peer_sid and the function
2826  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2827  * returns a negative value.  A table summarizing the behavior is below:
2828  *
2829  *                                 | function return |      @sid
2830  *   ------------------------------+-----------------+-----------------
2831  *   no peer labels                |        0        |    SECSID_NULL
2832  *   single peer label             |        0        |    <peer_label>
2833  *   multiple, consistent labels   |        0        |    <peer_label>
2834  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2835  *
2836  */
2837 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2838                                  u32 xfrm_sid,
2839                                  u32 *peer_sid)
2840 {
2841         int rc;
2842         struct context *nlbl_ctx;
2843         struct context *xfrm_ctx;
2844 
2845         *peer_sid = SECSID_NULL;
2846 
2847         /* handle the common (which also happens to be the set of easy) cases
2848          * right away, these two if statements catch everything involving a
2849          * single or absent peer SID/label */
2850         if (xfrm_sid == SECSID_NULL) {
2851                 *peer_sid = nlbl_sid;
2852                 return 0;
2853         }
2854         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2855          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2856          * is present */
2857         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2858                 *peer_sid = xfrm_sid;
2859                 return 0;
2860         }
2861 
2862         /* we don't need to check ss_initialized here since the only way both
2863          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2864          * security server was initialized and ss_initialized was true */
2865         if (!policydb.mls_enabled)
2866                 return 0;
2867 
2868         read_lock(&policy_rwlock);
2869 
2870         rc = -EINVAL;
2871         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2872         if (!nlbl_ctx) {
2873                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2874                        __func__, nlbl_sid);
2875                 goto out;
2876         }
2877         rc = -EINVAL;
2878         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2879         if (!xfrm_ctx) {
2880                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2881                        __func__, xfrm_sid);
2882                 goto out;
2883         }
2884         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2885         if (rc)
2886                 goto out;
2887 
2888         /* at present NetLabel SIDs/labels really only carry MLS
2889          * information so if the MLS portion of the NetLabel SID
2890          * matches the MLS portion of the labeled XFRM SID/label
2891          * then pass along the XFRM SID as it is the most
2892          * expressive */
2893         *peer_sid = xfrm_sid;
2894 out:
2895         read_unlock(&policy_rwlock);
2896         return rc;
2897 }
2898 
2899 static int get_classes_callback(void *k, void *d, void *args)
2900 {
2901         struct class_datum *datum = d;
2902         char *name = k, **classes = args;
2903         int value = datum->value - 1;
2904 
2905         classes[value] = kstrdup(name, GFP_ATOMIC);
2906         if (!classes[value])
2907                 return -ENOMEM;
2908 
2909         return 0;
2910 }
2911 
2912 int security_get_classes(char ***classes, int *nclasses)
2913 {
2914         int rc;
2915 
2916         read_lock(&policy_rwlock);
2917 
2918         rc = -ENOMEM;
2919         *nclasses = policydb.p_classes.nprim;
2920         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2921         if (!*classes)
2922                 goto out;
2923 
2924         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2925                         *classes);
2926         if (rc) {
2927                 int i;
2928                 for (i = 0; i < *nclasses; i++)
2929                         kfree((*classes)[i]);
2930                 kfree(*classes);
2931         }
2932 
2933 out:
2934         read_unlock(&policy_rwlock);
2935         return rc;
2936 }
2937 
2938 static int get_permissions_callback(void *k, void *d, void *args)
2939 {
2940         struct perm_datum *datum = d;
2941         char *name = k, **perms = args;
2942         int value = datum->value - 1;
2943 
2944         perms[value] = kstrdup(name, GFP_ATOMIC);
2945         if (!perms[value])
2946                 return -ENOMEM;
2947 
2948         return 0;
2949 }
2950 
2951 int security_get_permissions(char *class, char ***perms, int *nperms)
2952 {
2953         int rc, i;
2954         struct class_datum *match;
2955 
2956         read_lock(&policy_rwlock);
2957 
2958         rc = -EINVAL;
2959         match = hashtab_search(policydb.p_classes.table, class);
2960         if (!match) {
2961                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2962                         __func__, class);
2963                 goto out;
2964         }
2965 
2966         rc = -ENOMEM;
2967         *nperms = match->permissions.nprim;
2968         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2969         if (!*perms)
2970                 goto out;
2971 
2972         if (match->comdatum) {
2973                 rc = hashtab_map(match->comdatum->permissions.table,
2974                                 get_permissions_callback, *perms);
2975                 if (rc)
2976                         goto err;
2977         }
2978 
2979         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2980                         *perms);
2981         if (rc)
2982                 goto err;
2983 
2984 out:
2985         read_unlock(&policy_rwlock);
2986         return rc;
2987 
2988 err:
2989         read_unlock(&policy_rwlock);
2990         for (i = 0; i < *nperms; i++)
2991                 kfree((*perms)[i]);
2992         kfree(*perms);
2993         return rc;
2994 }
2995 
2996 int security_get_reject_unknown(void)
2997 {
2998         return policydb.reject_unknown;
2999 }
3000 
3001 int security_get_allow_unknown(void)
3002 {
3003         return policydb.allow_unknown;
3004 }
3005 
3006 /**
3007  * security_policycap_supported - Check for a specific policy capability
3008  * @req_cap: capability
3009  *
3010  * Description:
3011  * This function queries the currently loaded policy to see if it supports the
3012  * capability specified by @req_cap.  Returns true (1) if the capability is
3013  * supported, false (0) if it isn't supported.
3014  *
3015  */
3016 int security_policycap_supported(unsigned int req_cap)
3017 {
3018         int rc;
3019 
3020         read_lock(&policy_rwlock);
3021         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3022         read_unlock(&policy_rwlock);
3023 
3024         return rc;
3025 }
3026 
3027 struct selinux_audit_rule {
3028         u32 au_seqno;
3029         struct context au_ctxt;
3030 };
3031 
3032 void selinux_audit_rule_free(void *vrule)
3033 {
3034         struct selinux_audit_rule *rule = vrule;
3035 
3036         if (rule) {
3037                 context_destroy(&rule->au_ctxt);
3038                 kfree(rule);
3039         }
3040 }
3041 
3042 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3043 {
3044         struct selinux_audit_rule *tmprule;
3045         struct role_datum *roledatum;
3046         struct type_datum *typedatum;
3047         struct user_datum *userdatum;
3048         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3049         int rc = 0;
3050 
3051         *rule = NULL;
3052 
3053         if (!ss_initialized)
3054                 return -EOPNOTSUPP;
3055 
3056         switch (field) {
3057         case AUDIT_SUBJ_USER:
3058         case AUDIT_SUBJ_ROLE:
3059         case AUDIT_SUBJ_TYPE:
3060         case AUDIT_OBJ_USER:
3061         case AUDIT_OBJ_ROLE:
3062         case AUDIT_OBJ_TYPE:
3063                 /* only 'equals' and 'not equals' fit user, role, and type */
3064                 if (op != Audit_equal && op != Audit_not_equal)
3065                         return -EINVAL;
3066                 break;
3067         case AUDIT_SUBJ_SEN:
3068         case AUDIT_SUBJ_CLR:
3069         case AUDIT_OBJ_LEV_LOW:
3070         case AUDIT_OBJ_LEV_HIGH:
3071                 /* we do not allow a range, indicated by the presence of '-' */
3072                 if (strchr(rulestr, '-'))
3073                         return -EINVAL;
3074                 break;
3075         default:
3076                 /* only the above fields are valid */
3077                 return -EINVAL;
3078         }
3079 
3080         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3081         if (!tmprule)
3082                 return -ENOMEM;
3083 
3084         context_init(&tmprule->au_ctxt);
3085 
3086         read_lock(&policy_rwlock);
3087 
3088         tmprule->au_seqno = latest_granting;
3089 
3090         switch (field) {
3091         case AUDIT_SUBJ_USER:
3092         case AUDIT_OBJ_USER:
3093                 rc = -EINVAL;
3094                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3095                 if (!userdatum)
3096                         goto out;
3097                 tmprule->au_ctxt.user = userdatum->value;
3098                 break;
3099         case AUDIT_SUBJ_ROLE:
3100         case AUDIT_OBJ_ROLE:
3101                 rc = -EINVAL;
3102                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3103                 if (!roledatum)
3104                         goto out;
3105                 tmprule->au_ctxt.role = roledatum->value;
3106                 break;
3107         case AUDIT_SUBJ_TYPE:
3108         case AUDIT_OBJ_TYPE:
3109                 rc = -EINVAL;
3110                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3111                 if (!typedatum)
3112                         goto out;
3113                 tmprule->au_ctxt.type = typedatum->value;
3114                 break;
3115         case AUDIT_SUBJ_SEN:
3116         case AUDIT_SUBJ_CLR:
3117         case AUDIT_OBJ_LEV_LOW:
3118         case AUDIT_OBJ_LEV_HIGH:
3119                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3120                 if (rc)
3121                         goto out;
3122                 break;
3123         }
3124         rc = 0;
3125 out:
3126         read_unlock(&policy_rwlock);
3127 
3128         if (rc) {
3129                 selinux_audit_rule_free(tmprule);
3130                 tmprule = NULL;
3131         }
3132 
3133         *rule = tmprule;
3134 
3135         return rc;
3136 }
3137 
3138 /* Check to see if the rule contains any selinux fields */
3139 int selinux_audit_rule_known(struct audit_krule *rule)
3140 {
3141         int i;
3142 
3143         for (i = 0; i < rule->field_count; i++) {
3144                 struct audit_field *f = &rule->fields[i];
3145                 switch (f->type) {
3146                 case AUDIT_SUBJ_USER:
3147                 case AUDIT_SUBJ_ROLE:
3148                 case AUDIT_SUBJ_TYPE:
3149                 case AUDIT_SUBJ_SEN:
3150                 case AUDIT_SUBJ_CLR:
3151                 case AUDIT_OBJ_USER:
3152                 case AUDIT_OBJ_ROLE:
3153                 case AUDIT_OBJ_TYPE:
3154                 case AUDIT_OBJ_LEV_LOW:
3155                 case AUDIT_OBJ_LEV_HIGH:
3156                         return 1;
3157                 }
3158         }
3159 
3160         return 0;
3161 }
3162 
3163 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3164                              struct audit_context *actx)
3165 {
3166         struct context *ctxt;
3167         struct mls_level *level;
3168         struct selinux_audit_rule *rule = vrule;
3169         int match = 0;
3170 
3171         if (unlikely(!rule)) {
3172                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3173                 return -ENOENT;
3174         }
3175 
3176         read_lock(&policy_rwlock);
3177 
3178         if (rule->au_seqno < latest_granting) {
3179                 match = -ESTALE;
3180                 goto out;
3181         }
3182 
3183         ctxt = sidtab_search(&sidtab, sid);
3184         if (unlikely(!ctxt)) {
3185                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3186                           sid);
3187                 match = -ENOENT;
3188                 goto out;
3189         }
3190 
3191         /* a field/op pair that is not caught here will simply fall through
3192            without a match */
3193         switch (field) {
3194         case AUDIT_SUBJ_USER:
3195         case AUDIT_OBJ_USER:
3196                 switch (op) {
3197                 case Audit_equal:
3198                         match = (ctxt->user == rule->au_ctxt.user);
3199                         break;
3200                 case Audit_not_equal:
3201                         match = (ctxt->user != rule->au_ctxt.user);
3202                         break;
3203                 }
3204                 break;
3205         case AUDIT_SUBJ_ROLE:
3206         case AUDIT_OBJ_ROLE:
3207                 switch (op) {
3208                 case Audit_equal:
3209                         match = (ctxt->role == rule->au_ctxt.role);
3210                         break;
3211                 case Audit_not_equal:
3212                         match = (ctxt->role != rule->au_ctxt.role);
3213                         break;
3214                 }
3215                 break;
3216         case AUDIT_SUBJ_TYPE:
3217         case AUDIT_OBJ_TYPE:
3218                 switch (op) {
3219                 case Audit_equal:
3220                         match = (ctxt->type == rule->au_ctxt.type);
3221                         break;
3222                 case Audit_not_equal:
3223                         match = (ctxt->type != rule->au_ctxt.type);
3224                         break;
3225                 }
3226                 break;
3227         case AUDIT_SUBJ_SEN:
3228         case AUDIT_SUBJ_CLR:
3229         case AUDIT_OBJ_LEV_LOW:
3230         case AUDIT_OBJ_LEV_HIGH:
3231                 level = ((field == AUDIT_SUBJ_SEN ||
3232                           field == AUDIT_OBJ_LEV_LOW) ?
3233                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3234                 switch (op) {
3235                 case Audit_equal:
3236                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3237                                              level);
3238                         break;
3239                 case Audit_not_equal:
3240                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3241                                               level);
3242                         break;
3243                 case Audit_lt:
3244                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3245                                                level) &&
3246                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3247                                                level));
3248                         break;
3249                 case Audit_le:
3250                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3251                                               level);
3252                         break;
3253                 case Audit_gt:
3254                         match = (mls_level_dom(level,
3255                                               &rule->au_ctxt.range.level[0]) &&
3256                                  !mls_level_eq(level,
3257                                                &rule->au_ctxt.range.level[0]));
3258                         break;
3259                 case Audit_ge:
3260                         match = mls_level_dom(level,
3261                                               &rule->au_ctxt.range.level[0]);
3262                         break;
3263                 }
3264         }
3265 
3266 out:
3267         read_unlock(&policy_rwlock);
3268         return match;
3269 }
3270 
3271 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3272 
3273 static int aurule_avc_callback(u32 event)
3274 {
3275         int err = 0;
3276 
3277         if (event == AVC_CALLBACK_RESET && aurule_callback)
3278                 err = aurule_callback();
3279         return err;
3280 }
3281 
3282 static int __init aurule_init(void)
3283 {
3284         int err;
3285 
3286         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3287         if (err)
3288                 panic("avc_add_callback() failed, error %d\n", err);
3289 
3290         return err;
3291 }
3292 __initcall(aurule_init);
3293 
3294 #ifdef CONFIG_NETLABEL
3295 /**
3296  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3297  * @secattr: the NetLabel packet security attributes
3298  * @sid: the SELinux SID
3299  *
3300  * Description:
3301  * Attempt to cache the context in @ctx, which was derived from the packet in
3302  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3303  * already been initialized.
3304  *
3305  */
3306 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3307                                       u32 sid)
3308 {
3309         u32 *sid_cache;
3310 
3311         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3312         if (sid_cache == NULL)
3313                 return;
3314         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3315         if (secattr->cache == NULL) {
3316                 kfree(sid_cache);
3317                 return;
3318         }
3319 
3320         *sid_cache = sid;
3321         secattr->cache->free = kfree;
3322         secattr->cache->data = sid_cache;
3323         secattr->flags |= NETLBL_SECATTR_CACHE;
3324 }
3325 
3326 /**
3327  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3328  * @secattr: the NetLabel packet security attributes
3329  * @sid: the SELinux SID
3330  *
3331  * Description:
3332  * Convert the given NetLabel security attributes in @secattr into a
3333  * SELinux SID.  If the @secattr field does not contain a full SELinux
3334  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3335  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3336  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3337  * conversion for future lookups.  Returns zero on success, negative values on
3338  * failure.
3339  *
3340  */
3341 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3342                                    u32 *sid)
3343 {
3344         int rc;
3345         struct context *ctx;
3346         struct context ctx_new;
3347 
3348         if (!ss_initialized) {
3349                 *sid = SECSID_NULL;
3350                 return 0;
3351         }
3352 
3353         read_lock(&policy_rwlock);
3354 
3355         if (secattr->flags & NETLBL_SECATTR_CACHE)
3356                 *sid = *(u32 *)secattr->cache->data;
3357         else if (secattr->flags & NETLBL_SECATTR_SECID)
3358                 *sid = secattr->attr.secid;
3359         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3360                 rc = -EIDRM;
3361                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3362                 if (ctx == NULL)
3363                         goto out;
3364 
3365                 context_init(&ctx_new);
3366                 ctx_new.user = ctx->user;
3367                 ctx_new.role = ctx->role;
3368                 ctx_new.type = ctx->type;
3369                 mls_import_netlbl_lvl(&ctx_new, secattr);
3370                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3371                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3372                         if (rc)
3373                                 goto out;
3374                 }
3375                 rc = -EIDRM;
3376                 if (!mls_context_isvalid(&policydb, &ctx_new))
3377                         goto out_free;
3378 
3379                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3380                 if (rc)
3381                         goto out_free;
3382 
3383                 security_netlbl_cache_add(secattr, *sid);
3384 
3385                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3386         } else
3387                 *sid = SECSID_NULL;
3388 
3389         read_unlock(&policy_rwlock);
3390         return 0;
3391 out_free:
3392         ebitmap_destroy(&ctx_new.range.level[0].cat);
3393 out:
3394         read_unlock(&policy_rwlock);
3395         return rc;
3396 }
3397 
3398 /**
3399  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3400  * @sid: the SELinux SID
3401  * @secattr: the NetLabel packet security attributes
3402  *
3403  * Description:
3404  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3405  * Returns zero on success, negative values on failure.
3406  *
3407  */
3408 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3409 {
3410         int rc;
3411         struct context *ctx;
3412 
3413         if (!ss_initialized)
3414                 return 0;
3415 
3416         read_lock(&policy_rwlock);
3417 
3418         rc = -ENOENT;
3419         ctx = sidtab_search(&sidtab, sid);
3420         if (ctx == NULL)
3421                 goto out;
3422 
3423         rc = -ENOMEM;
3424         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3425                                   GFP_ATOMIC);
3426         if (secattr->domain == NULL)
3427                 goto out;
3428 
3429         secattr->attr.secid = sid;
3430         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3431         mls_export_netlbl_lvl(ctx, secattr);
3432         rc = mls_export_netlbl_cat(ctx, secattr);
3433 out:
3434         read_unlock(&policy_rwlock);
3435         return rc;
3436 }
3437 #endif /* CONFIG_NETLABEL */
3438 
3439 /**
3440  * security_read_policy - read the policy.
3441  * @data: binary policy data
3442  * @len: length of data in bytes
3443  *
3444  */
3445 int security_read_policy(void **data, size_t *len)
3446 {
3447         int rc;
3448         struct policy_file fp;
3449 
3450         if (!ss_initialized)
3451                 return -EINVAL;
3452 
3453         *len = security_policydb_len();
3454 
3455         *data = vmalloc_user(*len);
3456         if (!*data)
3457                 return -ENOMEM;
3458 
3459         fp.data = *data;
3460         fp.len = *len;
3461 
3462         read_lock(&policy_rwlock);
3463         rc = policydb_write(&policydb, &fp);
3464         read_unlock(&policy_rwlock);
3465 
3466         if (rc)
3467                 return rc;
3468 
3469         *len = (unsigned long)fp.data - (unsigned long)*data;
3470         return 0;
3471 
3472 }
3473 

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