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

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  1 /*
  2  * Implementation of the security services.
  3  *
  4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
  5  *           James Morris <jmorris@redhat.com>
  6  *
  7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
  8  *
  9  *      Support for enhanced MLS infrastructure.
 10  *      Support for context based audit filters.
 11  *
 12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 13  *
 14  *      Added conditional policy language extensions
 15  *
 16  * Updated: Hewlett-Packard <paul@paul-moore.com>
 17  *
 18  *      Added support for NetLabel
 19  *      Added support for the policy capability bitmap
 20  *
 21  * Updated: Chad Sellers <csellers@tresys.com>
 22  *
 23  *  Added validation of kernel classes and permissions
 24  *
 25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
 26  *
 27  *  Added support for bounds domain and audit messaged on masked permissions
 28  *
 29  * Updated: Guido Trentalancia <guido@trentalancia.com>
 30  *
 31  *  Added support for runtime switching of the policy type
 32  *
 33  * Copyright (C) 2008, 2009 NEC Corporation
 34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
 35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
 36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
 37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
 38  *      This program is free software; you can redistribute it and/or modify
 39  *      it under the terms of the GNU General Public License as published by
 40  *      the Free Software Foundation, version 2.
 41  */
 42 #include <linux/kernel.h>
 43 #include <linux/slab.h>
 44 #include <linux/string.h>
 45 #include <linux/spinlock.h>
 46 #include <linux/rcupdate.h>
 47 #include <linux/errno.h>
 48 #include <linux/in.h>
 49 #include <linux/sched.h>
 50 #include <linux/audit.h>
 51 #include <linux/mutex.h>
 52 #include <linux/selinux.h>
 53 #include <linux/flex_array.h>
 54 #include <linux/vmalloc.h>
 55 #include <net/netlabel.h>
 56 
 57 #include "flask.h"
 58 #include "avc.h"
 59 #include "avc_ss.h"
 60 #include "security.h"
 61 #include "context.h"
 62 #include "policydb.h"
 63 #include "sidtab.h"
 64 #include "services.h"
 65 #include "conditional.h"
 66 #include "mls.h"
 67 #include "objsec.h"
 68 #include "netlabel.h"
 69 #include "xfrm.h"
 70 #include "ebitmap.h"
 71 #include "audit.h"
 72 
 73 int selinux_policycap_netpeer;
 74 int selinux_policycap_openperm;
 75 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, *tcontextp = 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         if (!source->bounds)
557                 return;
558 
559         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
560                                     tcontext->type - 1);
561         BUG_ON(!target);
562 
563         memset(&lo_avd, 0, sizeof(lo_avd));
564 
565         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
566         lo_scontext.type = source->bounds;
567 
568         if (target->bounds) {
569                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
570                 lo_tcontext.type = target->bounds;
571                 tcontextp = &lo_tcontext;
572         }
573 
574         context_struct_compute_av(&lo_scontext,
575                                   tcontextp,
576                                   tclass,
577                                   &lo_avd,
578                                   NULL);
579 
580         masked = ~lo_avd.allowed & avd->allowed;
581 
582         if (likely(!masked))
583                 return;         /* no masked permission */
584 
585         /* mask violated permissions */
586         avd->allowed &= ~masked;
587 
588         /* audit masked permissions */
589         security_dump_masked_av(scontext, tcontext,
590                                 tclass, masked, "bounds");
591 }
592 
593 /*
594  * flag which drivers have permissions
595  * only looking for ioctl based extended permssions
596  */
597 void services_compute_xperms_drivers(
598                 struct extended_perms *xperms,
599                 struct avtab_node *node)
600 {
601         unsigned int i;
602 
603         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
604                 /* if one or more driver has all permissions allowed */
605                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
606                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
607         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
608                 /* if allowing permissions within a driver */
609                 security_xperm_set(xperms->drivers.p,
610                                         node->datum.u.xperms->driver);
611         }
612 
613         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
614         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
615                 xperms->len = 1;
616 }
617 
618 /*
619  * Compute access vectors and extended permissions based on a context
620  * structure pair for the permissions in a particular class.
621  */
622 static void context_struct_compute_av(struct context *scontext,
623                                         struct context *tcontext,
624                                         u16 tclass,
625                                         struct av_decision *avd,
626                                         struct extended_perms *xperms)
627 {
628         struct constraint_node *constraint;
629         struct role_allow *ra;
630         struct avtab_key avkey;
631         struct avtab_node *node;
632         struct class_datum *tclass_datum;
633         struct ebitmap *sattr, *tattr;
634         struct ebitmap_node *snode, *tnode;
635         unsigned int i, j;
636 
637         avd->allowed = 0;
638         avd->auditallow = 0;
639         avd->auditdeny = 0xffffffff;
640         if (xperms) {
641                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
642                 xperms->len = 0;
643         }
644 
645         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
646                 if (printk_ratelimit())
647                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
648                 return;
649         }
650 
651         tclass_datum = policydb.class_val_to_struct[tclass - 1];
652 
653         /*
654          * If a specific type enforcement rule was defined for
655          * this permission check, then use it.
656          */
657         avkey.target_class = tclass;
658         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
659         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
660         BUG_ON(!sattr);
661         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
662         BUG_ON(!tattr);
663         ebitmap_for_each_positive_bit(sattr, snode, i) {
664                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
665                         avkey.source_type = i + 1;
666                         avkey.target_type = j + 1;
667                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
668                              node;
669                              node = avtab_search_node_next(node, avkey.specified)) {
670                                 if (node->key.specified == AVTAB_ALLOWED)
671                                         avd->allowed |= node->datum.u.data;
672                                 else if (node->key.specified == AVTAB_AUDITALLOW)
673                                         avd->auditallow |= node->datum.u.data;
674                                 else if (node->key.specified == AVTAB_AUDITDENY)
675                                         avd->auditdeny &= node->datum.u.data;
676                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
677                                         services_compute_xperms_drivers(xperms, node);
678                         }
679 
680                         /* Check conditional av table for additional permissions */
681                         cond_compute_av(&policydb.te_cond_avtab, &avkey,
682                                         avd, xperms);
683 
684                 }
685         }
686 
687         /*
688          * Remove any permissions prohibited by a constraint (this includes
689          * the MLS policy).
690          */
691         constraint = tclass_datum->constraints;
692         while (constraint) {
693                 if ((constraint->permissions & (avd->allowed)) &&
694                     !constraint_expr_eval(scontext, tcontext, NULL,
695                                           constraint->expr)) {
696                         avd->allowed &= ~(constraint->permissions);
697                 }
698                 constraint = constraint->next;
699         }
700 
701         /*
702          * If checking process transition permission and the
703          * role is changing, then check the (current_role, new_role)
704          * pair.
705          */
706         if (tclass == policydb.process_class &&
707             (avd->allowed & policydb.process_trans_perms) &&
708             scontext->role != tcontext->role) {
709                 for (ra = policydb.role_allow; ra; ra = ra->next) {
710                         if (scontext->role == ra->role &&
711                             tcontext->role == ra->new_role)
712                                 break;
713                 }
714                 if (!ra)
715                         avd->allowed &= ~policydb.process_trans_perms;
716         }
717 
718         /*
719          * If the given source and target types have boundary
720          * constraint, lazy checks have to mask any violated
721          * permission and notice it to userspace via audit.
722          */
723         type_attribute_bounds_av(scontext, tcontext,
724                                  tclass, avd);
725 }
726 
727 static int security_validtrans_handle_fail(struct context *ocontext,
728                                            struct context *ncontext,
729                                            struct context *tcontext,
730                                            u16 tclass)
731 {
732         char *o = NULL, *n = NULL, *t = NULL;
733         u32 olen, nlen, tlen;
734 
735         if (context_struct_to_string(ocontext, &o, &olen))
736                 goto out;
737         if (context_struct_to_string(ncontext, &n, &nlen))
738                 goto out;
739         if (context_struct_to_string(tcontext, &t, &tlen))
740                 goto out;
741         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
742                   "op=security_validate_transition seresult=denied"
743                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
744                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
745 out:
746         kfree(o);
747         kfree(n);
748         kfree(t);
749 
750         if (!selinux_enforcing)
751                 return 0;
752         return -EPERM;
753 }
754 
755 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
756                                           u16 orig_tclass, bool user)
757 {
758         struct context *ocontext;
759         struct context *ncontext;
760         struct context *tcontext;
761         struct class_datum *tclass_datum;
762         struct constraint_node *constraint;
763         u16 tclass;
764         int rc = 0;
765 
766         if (!ss_initialized)
767                 return 0;
768 
769         read_lock(&policy_rwlock);
770 
771         if (!user)
772                 tclass = unmap_class(orig_tclass);
773         else
774                 tclass = orig_tclass;
775 
776         if (!tclass || tclass > policydb.p_classes.nprim) {
777                 rc = -EINVAL;
778                 goto out;
779         }
780         tclass_datum = policydb.class_val_to_struct[tclass - 1];
781 
782         ocontext = sidtab_search(&sidtab, oldsid);
783         if (!ocontext) {
784                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
785                         __func__, oldsid);
786                 rc = -EINVAL;
787                 goto out;
788         }
789 
790         ncontext = sidtab_search(&sidtab, newsid);
791         if (!ncontext) {
792                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
793                         __func__, newsid);
794                 rc = -EINVAL;
795                 goto out;
796         }
797 
798         tcontext = sidtab_search(&sidtab, tasksid);
799         if (!tcontext) {
800                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
801                         __func__, tasksid);
802                 rc = -EINVAL;
803                 goto out;
804         }
805 
806         constraint = tclass_datum->validatetrans;
807         while (constraint) {
808                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
809                                           constraint->expr)) {
810                         if (user)
811                                 rc = -EPERM;
812                         else
813                                 rc = security_validtrans_handle_fail(ocontext,
814                                                                      ncontext,
815                                                                      tcontext,
816                                                                      tclass);
817                         goto out;
818                 }
819                 constraint = constraint->next;
820         }
821 
822 out:
823         read_unlock(&policy_rwlock);
824         return rc;
825 }
826 
827 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
828                                         u16 tclass)
829 {
830         return security_compute_validatetrans(oldsid, newsid, tasksid,
831                                                 tclass, true);
832 }
833 
834 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
835                                  u16 orig_tclass)
836 {
837         return security_compute_validatetrans(oldsid, newsid, tasksid,
838                                                 orig_tclass, false);
839 }
840 
841 /*
842  * security_bounded_transition - check whether the given
843  * transition is directed to bounded, or not.
844  * It returns 0, if @newsid is bounded by @oldsid.
845  * Otherwise, it returns error code.
846  *
847  * @oldsid : current security identifier
848  * @newsid : destinated security identifier
849  */
850 int security_bounded_transition(u32 old_sid, u32 new_sid)
851 {
852         struct context *old_context, *new_context;
853         struct type_datum *type;
854         int index;
855         int rc;
856 
857         read_lock(&policy_rwlock);
858 
859         rc = -EINVAL;
860         old_context = sidtab_search(&sidtab, old_sid);
861         if (!old_context) {
862                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
863                        __func__, old_sid);
864                 goto out;
865         }
866 
867         rc = -EINVAL;
868         new_context = sidtab_search(&sidtab, new_sid);
869         if (!new_context) {
870                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
871                        __func__, new_sid);
872                 goto out;
873         }
874 
875         rc = 0;
876         /* type/domain unchanged */
877         if (old_context->type == new_context->type)
878                 goto out;
879 
880         index = new_context->type;
881         while (true) {
882                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
883                                           index - 1);
884                 BUG_ON(!type);
885 
886                 /* not bounded anymore */
887                 rc = -EPERM;
888                 if (!type->bounds)
889                         break;
890 
891                 /* @newsid is bounded by @oldsid */
892                 rc = 0;
893                 if (type->bounds == old_context->type)
894                         break;
895 
896                 index = type->bounds;
897         }
898 
899         if (rc) {
900                 char *old_name = NULL;
901                 char *new_name = NULL;
902                 u32 length;
903 
904                 if (!context_struct_to_string(old_context,
905                                               &old_name, &length) &&
906                     !context_struct_to_string(new_context,
907                                               &new_name, &length)) {
908                         audit_log(current->audit_context,
909                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
910                                   "op=security_bounded_transition "
911                                   "seresult=denied "
912                                   "oldcontext=%s newcontext=%s",
913                                   old_name, new_name);
914                 }
915                 kfree(new_name);
916                 kfree(old_name);
917         }
918 out:
919         read_unlock(&policy_rwlock);
920 
921         return rc;
922 }
923 
924 static void avd_init(struct av_decision *avd)
925 {
926         avd->allowed = 0;
927         avd->auditallow = 0;
928         avd->auditdeny = 0xffffffff;
929         avd->seqno = latest_granting;
930         avd->flags = 0;
931 }
932 
933 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
934                                         struct avtab_node *node)
935 {
936         unsigned int i;
937 
938         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
939                 if (xpermd->driver != node->datum.u.xperms->driver)
940                         return;
941         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
942                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
943                                         xpermd->driver))
944                         return;
945         } else {
946                 BUG();
947         }
948 
949         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
950                 xpermd->used |= XPERMS_ALLOWED;
951                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
952                         memset(xpermd->allowed->p, 0xff,
953                                         sizeof(xpermd->allowed->p));
954                 }
955                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
956                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
957                                 xpermd->allowed->p[i] |=
958                                         node->datum.u.xperms->perms.p[i];
959                 }
960         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
961                 xpermd->used |= XPERMS_AUDITALLOW;
962                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
963                         memset(xpermd->auditallow->p, 0xff,
964                                         sizeof(xpermd->auditallow->p));
965                 }
966                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
967                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
968                                 xpermd->auditallow->p[i] |=
969                                         node->datum.u.xperms->perms.p[i];
970                 }
971         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
972                 xpermd->used |= XPERMS_DONTAUDIT;
973                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
974                         memset(xpermd->dontaudit->p, 0xff,
975                                         sizeof(xpermd->dontaudit->p));
976                 }
977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
978                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
979                                 xpermd->dontaudit->p[i] |=
980                                         node->datum.u.xperms->perms.p[i];
981                 }
982         } else {
983                 BUG();
984         }
985 }
986 
987 void security_compute_xperms_decision(u32 ssid,
988                                 u32 tsid,
989                                 u16 orig_tclass,
990                                 u8 driver,
991                                 struct extended_perms_decision *xpermd)
992 {
993         u16 tclass;
994         struct context *scontext, *tcontext;
995         struct avtab_key avkey;
996         struct avtab_node *node;
997         struct ebitmap *sattr, *tattr;
998         struct ebitmap_node *snode, *tnode;
999         unsigned int i, j;
1000 
1001         xpermd->driver = driver;
1002         xpermd->used = 0;
1003         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1004         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1005         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1006 
1007         read_lock(&policy_rwlock);
1008         if (!ss_initialized)
1009                 goto allow;
1010 
1011         scontext = sidtab_search(&sidtab, ssid);
1012         if (!scontext) {
1013                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1014                        __func__, ssid);
1015                 goto out;
1016         }
1017 
1018         tcontext = sidtab_search(&sidtab, tsid);
1019         if (!tcontext) {
1020                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1021                        __func__, tsid);
1022                 goto out;
1023         }
1024 
1025         tclass = unmap_class(orig_tclass);
1026         if (unlikely(orig_tclass && !tclass)) {
1027                 if (policydb.allow_unknown)
1028                         goto allow;
1029                 goto out;
1030         }
1031 
1032 
1033         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1034                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1035                 goto out;
1036         }
1037 
1038         avkey.target_class = tclass;
1039         avkey.specified = AVTAB_XPERMS;
1040         sattr = flex_array_get(policydb.type_attr_map_array,
1041                                 scontext->type - 1);
1042         BUG_ON(!sattr);
1043         tattr = flex_array_get(policydb.type_attr_map_array,
1044                                 tcontext->type - 1);
1045         BUG_ON(!tattr);
1046         ebitmap_for_each_positive_bit(sattr, snode, i) {
1047                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1048                         avkey.source_type = i + 1;
1049                         avkey.target_type = j + 1;
1050                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1051                              node;
1052                              node = avtab_search_node_next(node, avkey.specified))
1053                                 services_compute_xperms_decision(xpermd, node);
1054 
1055                         cond_compute_xperms(&policydb.te_cond_avtab,
1056                                                 &avkey, xpermd);
1057                 }
1058         }
1059 out:
1060         read_unlock(&policy_rwlock);
1061         return;
1062 allow:
1063         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1064         goto out;
1065 }
1066 
1067 /**
1068  * security_compute_av - Compute access vector decisions.
1069  * @ssid: source security identifier
1070  * @tsid: target security identifier
1071  * @tclass: target security class
1072  * @avd: access vector decisions
1073  * @xperms: extended permissions
1074  *
1075  * Compute a set of access vector decisions based on the
1076  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1077  */
1078 void security_compute_av(u32 ssid,
1079                          u32 tsid,
1080                          u16 orig_tclass,
1081                          struct av_decision *avd,
1082                          struct extended_perms *xperms)
1083 {
1084         u16 tclass;
1085         struct context *scontext = NULL, *tcontext = NULL;
1086 
1087         read_lock(&policy_rwlock);
1088         avd_init(avd);
1089         xperms->len = 0;
1090         if (!ss_initialized)
1091                 goto allow;
1092 
1093         scontext = sidtab_search(&sidtab, ssid);
1094         if (!scontext) {
1095                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1096                        __func__, ssid);
1097                 goto out;
1098         }
1099 
1100         /* permissive domain? */
1101         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1102                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1103 
1104         tcontext = sidtab_search(&sidtab, tsid);
1105         if (!tcontext) {
1106                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1107                        __func__, tsid);
1108                 goto out;
1109         }
1110 
1111         tclass = unmap_class(orig_tclass);
1112         if (unlikely(orig_tclass && !tclass)) {
1113                 if (policydb.allow_unknown)
1114                         goto allow;
1115                 goto out;
1116         }
1117         context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1118         map_decision(orig_tclass, avd, policydb.allow_unknown);
1119 out:
1120         read_unlock(&policy_rwlock);
1121         return;
1122 allow:
1123         avd->allowed = 0xffffffff;
1124         goto out;
1125 }
1126 
1127 void security_compute_av_user(u32 ssid,
1128                               u32 tsid,
1129                               u16 tclass,
1130                               struct av_decision *avd)
1131 {
1132         struct context *scontext = NULL, *tcontext = NULL;
1133 
1134         read_lock(&policy_rwlock);
1135         avd_init(avd);
1136         if (!ss_initialized)
1137                 goto allow;
1138 
1139         scontext = sidtab_search(&sidtab, ssid);
1140         if (!scontext) {
1141                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1142                        __func__, ssid);
1143                 goto out;
1144         }
1145 
1146         /* permissive domain? */
1147         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1148                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1149 
1150         tcontext = sidtab_search(&sidtab, tsid);
1151         if (!tcontext) {
1152                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1153                        __func__, tsid);
1154                 goto out;
1155         }
1156 
1157         if (unlikely(!tclass)) {
1158                 if (policydb.allow_unknown)
1159                         goto allow;
1160                 goto out;
1161         }
1162 
1163         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1164  out:
1165         read_unlock(&policy_rwlock);
1166         return;
1167 allow:
1168         avd->allowed = 0xffffffff;
1169         goto out;
1170 }
1171 
1172 /*
1173  * Write the security context string representation of
1174  * the context structure `context' into a dynamically
1175  * allocated string of the correct size.  Set `*scontext'
1176  * to point to this string and set `*scontext_len' to
1177  * the length of the string.
1178  */
1179 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1180 {
1181         char *scontextp;
1182 
1183         if (scontext)
1184                 *scontext = NULL;
1185         *scontext_len = 0;
1186 
1187         if (context->len) {
1188                 *scontext_len = context->len;
1189                 if (scontext) {
1190                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1191                         if (!(*scontext))
1192                                 return -ENOMEM;
1193                 }
1194                 return 0;
1195         }
1196 
1197         /* Compute the size of the context. */
1198         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1199         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1200         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1201         *scontext_len += mls_compute_context_len(context);
1202 
1203         if (!scontext)
1204                 return 0;
1205 
1206         /* Allocate space for the context; caller must free this space. */
1207         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1208         if (!scontextp)
1209                 return -ENOMEM;
1210         *scontext = scontextp;
1211 
1212         /*
1213          * Copy the user name, role name and type name into the context.
1214          */
1215         scontextp += sprintf(scontextp, "%s:%s:%s",
1216                 sym_name(&policydb, SYM_USERS, context->user - 1),
1217                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1218                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1219 
1220         mls_sid_to_context(context, &scontextp);
1221 
1222         *scontextp = 0;
1223 
1224         return 0;
1225 }
1226 
1227 #include "initial_sid_to_string.h"
1228 
1229 const char *security_get_initial_sid_context(u32 sid)
1230 {
1231         if (unlikely(sid > SECINITSID_NUM))
1232                 return NULL;
1233         return initial_sid_to_string[sid];
1234 }
1235 
1236 static int security_sid_to_context_core(u32 sid, char **scontext,
1237                                         u32 *scontext_len, int force)
1238 {
1239         struct context *context;
1240         int rc = 0;
1241 
1242         if (scontext)
1243                 *scontext = NULL;
1244         *scontext_len  = 0;
1245 
1246         if (!ss_initialized) {
1247                 if (sid <= SECINITSID_NUM) {
1248                         char *scontextp;
1249 
1250                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1251                         if (!scontext)
1252                                 goto out;
1253                         scontextp = kmemdup(initial_sid_to_string[sid],
1254                                             *scontext_len, GFP_ATOMIC);
1255                         if (!scontextp) {
1256                                 rc = -ENOMEM;
1257                                 goto out;
1258                         }
1259                         *scontext = scontextp;
1260                         goto out;
1261                 }
1262                 printk(KERN_ERR "SELinux: %s:  called before initial "
1263                        "load_policy on unknown SID %d\n", __func__, sid);
1264                 rc = -EINVAL;
1265                 goto out;
1266         }
1267         read_lock(&policy_rwlock);
1268         if (force)
1269                 context = sidtab_search_force(&sidtab, sid);
1270         else
1271                 context = sidtab_search(&sidtab, sid);
1272         if (!context) {
1273                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1274                         __func__, sid);
1275                 rc = -EINVAL;
1276                 goto out_unlock;
1277         }
1278         rc = context_struct_to_string(context, scontext, scontext_len);
1279 out_unlock:
1280         read_unlock(&policy_rwlock);
1281 out:
1282         return rc;
1283 
1284 }
1285 
1286 /**
1287  * security_sid_to_context - Obtain a context for a given SID.
1288  * @sid: security identifier, SID
1289  * @scontext: security context
1290  * @scontext_len: length in bytes
1291  *
1292  * Write the string representation of the context associated with @sid
1293  * into a dynamically allocated string of the correct size.  Set @scontext
1294  * to point to this string and set @scontext_len to the length of the string.
1295  */
1296 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1297 {
1298         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1299 }
1300 
1301 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1302 {
1303         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1304 }
1305 
1306 /*
1307  * Caveat:  Mutates scontext.
1308  */
1309 static int string_to_context_struct(struct policydb *pol,
1310                                     struct sidtab *sidtabp,
1311                                     char *scontext,
1312                                     u32 scontext_len,
1313                                     struct context *ctx,
1314                                     u32 def_sid)
1315 {
1316         struct role_datum *role;
1317         struct type_datum *typdatum;
1318         struct user_datum *usrdatum;
1319         char *scontextp, *p, oldc;
1320         int rc = 0;
1321 
1322         context_init(ctx);
1323 
1324         /* Parse the security context. */
1325 
1326         rc = -EINVAL;
1327         scontextp = (char *) scontext;
1328 
1329         /* Extract the user. */
1330         p = scontextp;
1331         while (*p && *p != ':')
1332                 p++;
1333 
1334         if (*p == 0)
1335                 goto out;
1336 
1337         *p++ = 0;
1338 
1339         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1340         if (!usrdatum)
1341                 goto out;
1342 
1343         ctx->user = usrdatum->value;
1344 
1345         /* Extract role. */
1346         scontextp = p;
1347         while (*p && *p != ':')
1348                 p++;
1349 
1350         if (*p == 0)
1351                 goto out;
1352 
1353         *p++ = 0;
1354 
1355         role = hashtab_search(pol->p_roles.table, scontextp);
1356         if (!role)
1357                 goto out;
1358         ctx->role = role->value;
1359 
1360         /* Extract type. */
1361         scontextp = p;
1362         while (*p && *p != ':')
1363                 p++;
1364         oldc = *p;
1365         *p++ = 0;
1366 
1367         typdatum = hashtab_search(pol->p_types.table, scontextp);
1368         if (!typdatum || typdatum->attribute)
1369                 goto out;
1370 
1371         ctx->type = typdatum->value;
1372 
1373         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1374         if (rc)
1375                 goto out;
1376 
1377         rc = -EINVAL;
1378         if ((p - scontext) < scontext_len)
1379                 goto out;
1380 
1381         /* Check the validity of the new context. */
1382         if (!policydb_context_isvalid(pol, ctx))
1383                 goto out;
1384         rc = 0;
1385 out:
1386         if (rc)
1387                 context_destroy(ctx);
1388         return rc;
1389 }
1390 
1391 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1392                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1393                                         int force)
1394 {
1395         char *scontext2, *str = NULL;
1396         struct context context;
1397         int rc = 0;
1398 
1399         /* An empty security context is never valid. */
1400         if (!scontext_len)
1401                 return -EINVAL;
1402 
1403         if (!ss_initialized) {
1404                 int i;
1405 
1406                 for (i = 1; i < SECINITSID_NUM; i++) {
1407                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1408                                 *sid = i;
1409                                 return 0;
1410                         }
1411                 }
1412                 *sid = SECINITSID_KERNEL;
1413                 return 0;
1414         }
1415         *sid = SECSID_NULL;
1416 
1417         /* Copy the string so that we can modify the copy as we parse it. */
1418         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1419         if (!scontext2)
1420                 return -ENOMEM;
1421         memcpy(scontext2, scontext, scontext_len);
1422         scontext2[scontext_len] = 0;
1423 
1424         if (force) {
1425                 /* Save another copy for storing in uninterpreted form */
1426                 rc = -ENOMEM;
1427                 str = kstrdup(scontext2, gfp_flags);
1428                 if (!str)
1429                         goto out;
1430         }
1431 
1432         read_lock(&policy_rwlock);
1433         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1434                                       scontext_len, &context, def_sid);
1435         if (rc == -EINVAL && force) {
1436                 context.str = str;
1437                 context.len = scontext_len;
1438                 str = NULL;
1439         } else if (rc)
1440                 goto out_unlock;
1441         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1442         context_destroy(&context);
1443 out_unlock:
1444         read_unlock(&policy_rwlock);
1445 out:
1446         kfree(scontext2);
1447         kfree(str);
1448         return rc;
1449 }
1450 
1451 /**
1452  * security_context_to_sid - Obtain a SID for a given security context.
1453  * @scontext: security context
1454  * @scontext_len: length in bytes
1455  * @sid: security identifier, SID
1456  * @gfp: context for the allocation
1457  *
1458  * Obtains a SID associated with the security context that
1459  * has the string representation specified by @scontext.
1460  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1461  * memory is available, or 0 on success.
1462  */
1463 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1464                             gfp_t gfp)
1465 {
1466         return security_context_to_sid_core(scontext, scontext_len,
1467                                             sid, SECSID_NULL, gfp, 0);
1468 }
1469 
1470 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1471 {
1472         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1473 }
1474 
1475 /**
1476  * security_context_to_sid_default - Obtain a SID for a given security context,
1477  * falling back to specified default if needed.
1478  *
1479  * @scontext: security context
1480  * @scontext_len: length in bytes
1481  * @sid: security identifier, SID
1482  * @def_sid: default SID to assign on error
1483  *
1484  * Obtains a SID associated with the security context that
1485  * has the string representation specified by @scontext.
1486  * The default SID is passed to the MLS layer to be used to allow
1487  * kernel labeling of the MLS field if the MLS field is not present
1488  * (for upgrading to MLS without full relabel).
1489  * Implicitly forces adding of the context even if it cannot be mapped yet.
1490  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1491  * memory is available, or 0 on success.
1492  */
1493 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1494                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1495 {
1496         return security_context_to_sid_core(scontext, scontext_len,
1497                                             sid, def_sid, gfp_flags, 1);
1498 }
1499 
1500 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1501                                   u32 *sid)
1502 {
1503         return security_context_to_sid_core(scontext, scontext_len,
1504                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1505 }
1506 
1507 static int compute_sid_handle_invalid_context(
1508         struct context *scontext,
1509         struct context *tcontext,
1510         u16 tclass,
1511         struct context *newcontext)
1512 {
1513         char *s = NULL, *t = NULL, *n = NULL;
1514         u32 slen, tlen, nlen;
1515 
1516         if (context_struct_to_string(scontext, &s, &slen))
1517                 goto out;
1518         if (context_struct_to_string(tcontext, &t, &tlen))
1519                 goto out;
1520         if (context_struct_to_string(newcontext, &n, &nlen))
1521                 goto out;
1522         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1523                   "op=security_compute_sid invalid_context=%s"
1524                   " scontext=%s"
1525                   " tcontext=%s"
1526                   " tclass=%s",
1527                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1528 out:
1529         kfree(s);
1530         kfree(t);
1531         kfree(n);
1532         if (!selinux_enforcing)
1533                 return 0;
1534         return -EACCES;
1535 }
1536 
1537 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1538                                   u32 stype, u32 ttype, u16 tclass,
1539                                   const char *objname)
1540 {
1541         struct filename_trans ft;
1542         struct filename_trans_datum *otype;
1543 
1544         /*
1545          * Most filename trans rules are going to live in specific directories
1546          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1547          * if the ttype does not contain any rules.
1548          */
1549         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1550                 return;
1551 
1552         ft.stype = stype;
1553         ft.ttype = ttype;
1554         ft.tclass = tclass;
1555         ft.name = objname;
1556 
1557         otype = hashtab_search(p->filename_trans, &ft);
1558         if (otype)
1559                 newcontext->type = otype->otype;
1560 }
1561 
1562 static int security_compute_sid(u32 ssid,
1563                                 u32 tsid,
1564                                 u16 orig_tclass,
1565                                 u32 specified,
1566                                 const char *objname,
1567                                 u32 *out_sid,
1568                                 bool kern)
1569 {
1570         struct class_datum *cladatum = NULL;
1571         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1572         struct role_trans *roletr = NULL;
1573         struct avtab_key avkey;
1574         struct avtab_datum *avdatum;
1575         struct avtab_node *node;
1576         u16 tclass;
1577         int rc = 0;
1578         bool sock;
1579 
1580         if (!ss_initialized) {
1581                 switch (orig_tclass) {
1582                 case SECCLASS_PROCESS: /* kernel value */
1583                         *out_sid = ssid;
1584                         break;
1585                 default:
1586                         *out_sid = tsid;
1587                         break;
1588                 }
1589                 goto out;
1590         }
1591 
1592         context_init(&newcontext);
1593 
1594         read_lock(&policy_rwlock);
1595 
1596         if (kern) {
1597                 tclass = unmap_class(orig_tclass);
1598                 sock = security_is_socket_class(orig_tclass);
1599         } else {
1600                 tclass = orig_tclass;
1601                 sock = security_is_socket_class(map_class(tclass));
1602         }
1603 
1604         scontext = sidtab_search(&sidtab, ssid);
1605         if (!scontext) {
1606                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1607                        __func__, ssid);
1608                 rc = -EINVAL;
1609                 goto out_unlock;
1610         }
1611         tcontext = sidtab_search(&sidtab, tsid);
1612         if (!tcontext) {
1613                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1614                        __func__, tsid);
1615                 rc = -EINVAL;
1616                 goto out_unlock;
1617         }
1618 
1619         if (tclass && tclass <= policydb.p_classes.nprim)
1620                 cladatum = policydb.class_val_to_struct[tclass - 1];
1621 
1622         /* Set the user identity. */
1623         switch (specified) {
1624         case AVTAB_TRANSITION:
1625         case AVTAB_CHANGE:
1626                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1627                         newcontext.user = tcontext->user;
1628                 } else {
1629                         /* notice this gets both DEFAULT_SOURCE and unset */
1630                         /* Use the process user identity. */
1631                         newcontext.user = scontext->user;
1632                 }
1633                 break;
1634         case AVTAB_MEMBER:
1635                 /* Use the related object owner. */
1636                 newcontext.user = tcontext->user;
1637                 break;
1638         }
1639 
1640         /* Set the role to default values. */
1641         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1642                 newcontext.role = scontext->role;
1643         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1644                 newcontext.role = tcontext->role;
1645         } else {
1646                 if ((tclass == policydb.process_class) || (sock == true))
1647                         newcontext.role = scontext->role;
1648                 else
1649                         newcontext.role = OBJECT_R_VAL;
1650         }
1651 
1652         /* Set the type to default values. */
1653         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1654                 newcontext.type = scontext->type;
1655         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1656                 newcontext.type = tcontext->type;
1657         } else {
1658                 if ((tclass == policydb.process_class) || (sock == true)) {
1659                         /* Use the type of process. */
1660                         newcontext.type = scontext->type;
1661                 } else {
1662                         /* Use the type of the related object. */
1663                         newcontext.type = tcontext->type;
1664                 }
1665         }
1666 
1667         /* Look for a type transition/member/change rule. */
1668         avkey.source_type = scontext->type;
1669         avkey.target_type = tcontext->type;
1670         avkey.target_class = tclass;
1671         avkey.specified = specified;
1672         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1673 
1674         /* If no permanent rule, also check for enabled conditional rules */
1675         if (!avdatum) {
1676                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1677                 for (; node; node = avtab_search_node_next(node, specified)) {
1678                         if (node->key.specified & AVTAB_ENABLED) {
1679                                 avdatum = &node->datum;
1680                                 break;
1681                         }
1682                 }
1683         }
1684 
1685         if (avdatum) {
1686                 /* Use the type from the type transition/member/change rule. */
1687                 newcontext.type = avdatum->u.data;
1688         }
1689 
1690         /* if we have a objname this is a file trans check so check those rules */
1691         if (objname)
1692                 filename_compute_type(&policydb, &newcontext, scontext->type,
1693                                       tcontext->type, tclass, objname);
1694 
1695         /* Check for class-specific changes. */
1696         if (specified & AVTAB_TRANSITION) {
1697                 /* Look for a role transition rule. */
1698                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1699                         if ((roletr->role == scontext->role) &&
1700                             (roletr->type == tcontext->type) &&
1701                             (roletr->tclass == tclass)) {
1702                                 /* Use the role transition rule. */
1703                                 newcontext.role = roletr->new_role;
1704                                 break;
1705                         }
1706                 }
1707         }
1708 
1709         /* Set the MLS attributes.
1710            This is done last because it may allocate memory. */
1711         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1712                              &newcontext, sock);
1713         if (rc)
1714                 goto out_unlock;
1715 
1716         /* Check the validity of the context. */
1717         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1718                 rc = compute_sid_handle_invalid_context(scontext,
1719                                                         tcontext,
1720                                                         tclass,
1721                                                         &newcontext);
1722                 if (rc)
1723                         goto out_unlock;
1724         }
1725         /* Obtain the sid for the context. */
1726         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1727 out_unlock:
1728         read_unlock(&policy_rwlock);
1729         context_destroy(&newcontext);
1730 out:
1731         return rc;
1732 }
1733 
1734 /**
1735  * security_transition_sid - Compute the SID for a new subject/object.
1736  * @ssid: source security identifier
1737  * @tsid: target security identifier
1738  * @tclass: target security class
1739  * @out_sid: security identifier for new subject/object
1740  *
1741  * Compute a SID to use for labeling a new subject or object in the
1742  * class @tclass based on a SID pair (@ssid, @tsid).
1743  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1744  * if insufficient memory is available, or %0 if the new SID was
1745  * computed successfully.
1746  */
1747 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1748                             const struct qstr *qstr, u32 *out_sid)
1749 {
1750         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1751                                     qstr ? qstr->name : NULL, out_sid, true);
1752 }
1753 
1754 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1755                                  const char *objname, u32 *out_sid)
1756 {
1757         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1758                                     objname, out_sid, false);
1759 }
1760 
1761 /**
1762  * security_member_sid - Compute the SID for member selection.
1763  * @ssid: source security identifier
1764  * @tsid: target security identifier
1765  * @tclass: target security class
1766  * @out_sid: security identifier for selected member
1767  *
1768  * Compute a SID to use when selecting a member of a polyinstantiated
1769  * object of class @tclass based on a SID pair (@ssid, @tsid).
1770  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1771  * if insufficient memory is available, or %0 if the SID was
1772  * computed successfully.
1773  */
1774 int security_member_sid(u32 ssid,
1775                         u32 tsid,
1776                         u16 tclass,
1777                         u32 *out_sid)
1778 {
1779         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1780                                     out_sid, false);
1781 }
1782 
1783 /**
1784  * security_change_sid - Compute the SID for object relabeling.
1785  * @ssid: source security identifier
1786  * @tsid: target security identifier
1787  * @tclass: target security class
1788  * @out_sid: security identifier for selected member
1789  *
1790  * Compute a SID to use for relabeling an object of class @tclass
1791  * based on a SID pair (@ssid, @tsid).
1792  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1793  * if insufficient memory is available, or %0 if the SID was
1794  * computed successfully.
1795  */
1796 int security_change_sid(u32 ssid,
1797                         u32 tsid,
1798                         u16 tclass,
1799                         u32 *out_sid)
1800 {
1801         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1802                                     out_sid, false);
1803 }
1804 
1805 /* Clone the SID into the new SID table. */
1806 static int clone_sid(u32 sid,
1807                      struct context *context,
1808                      void *arg)
1809 {
1810         struct sidtab *s = arg;
1811 
1812         if (sid > SECINITSID_NUM)
1813                 return sidtab_insert(s, sid, context);
1814         else
1815                 return 0;
1816 }
1817 
1818 static inline int convert_context_handle_invalid_context(struct context *context)
1819 {
1820         char *s;
1821         u32 len;
1822 
1823         if (selinux_enforcing)
1824                 return -EINVAL;
1825 
1826         if (!context_struct_to_string(context, &s, &len)) {
1827                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1828                 kfree(s);
1829         }
1830         return 0;
1831 }
1832 
1833 struct convert_context_args {
1834         struct policydb *oldp;
1835         struct policydb *newp;
1836 };
1837 
1838 /*
1839  * Convert the values in the security context
1840  * structure `c' from the values specified
1841  * in the policy `p->oldp' to the values specified
1842  * in the policy `p->newp'.  Verify that the
1843  * context is valid under the new policy.
1844  */
1845 static int convert_context(u32 key,
1846                            struct context *c,
1847                            void *p)
1848 {
1849         struct convert_context_args *args;
1850         struct context oldc;
1851         struct ocontext *oc;
1852         struct mls_range *range;
1853         struct role_datum *role;
1854         struct type_datum *typdatum;
1855         struct user_datum *usrdatum;
1856         char *s;
1857         u32 len;
1858         int rc = 0;
1859 
1860         if (key <= SECINITSID_NUM)
1861                 goto out;
1862 
1863         args = p;
1864 
1865         if (c->str) {
1866                 struct context ctx;
1867 
1868                 rc = -ENOMEM;
1869                 s = kstrdup(c->str, GFP_KERNEL);
1870                 if (!s)
1871                         goto out;
1872 
1873                 rc = string_to_context_struct(args->newp, NULL, s,
1874                                               c->len, &ctx, SECSID_NULL);
1875                 kfree(s);
1876                 if (!rc) {
1877                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1878                                c->str);
1879                         /* Replace string with mapped representation. */
1880                         kfree(c->str);
1881                         memcpy(c, &ctx, sizeof(*c));
1882                         goto out;
1883                 } else if (rc == -EINVAL) {
1884                         /* Retain string representation for later mapping. */
1885                         rc = 0;
1886                         goto out;
1887                 } else {
1888                         /* Other error condition, e.g. ENOMEM. */
1889                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1890                                c->str, -rc);
1891                         goto out;
1892                 }
1893         }
1894 
1895         rc = context_cpy(&oldc, c);
1896         if (rc)
1897                 goto out;
1898 
1899         /* Convert the user. */
1900         rc = -EINVAL;
1901         usrdatum = hashtab_search(args->newp->p_users.table,
1902                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1903         if (!usrdatum)
1904                 goto bad;
1905         c->user = usrdatum->value;
1906 
1907         /* Convert the role. */
1908         rc = -EINVAL;
1909         role = hashtab_search(args->newp->p_roles.table,
1910                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1911         if (!role)
1912                 goto bad;
1913         c->role = role->value;
1914 
1915         /* Convert the type. */
1916         rc = -EINVAL;
1917         typdatum = hashtab_search(args->newp->p_types.table,
1918                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1919         if (!typdatum)
1920                 goto bad;
1921         c->type = typdatum->value;
1922 
1923         /* Convert the MLS fields if dealing with MLS policies */
1924         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1925                 rc = mls_convert_context(args->oldp, args->newp, c);
1926                 if (rc)
1927                         goto bad;
1928         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1929                 /*
1930                  * Switching between MLS and non-MLS policy:
1931                  * free any storage used by the MLS fields in the
1932                  * context for all existing entries in the sidtab.
1933                  */
1934                 mls_context_destroy(c);
1935         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1936                 /*
1937                  * Switching between non-MLS and MLS policy:
1938                  * ensure that the MLS fields of the context for all
1939                  * existing entries in the sidtab are filled in with a
1940                  * suitable default value, likely taken from one of the
1941                  * initial SIDs.
1942                  */
1943                 oc = args->newp->ocontexts[OCON_ISID];
1944                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1945                         oc = oc->next;
1946                 rc = -EINVAL;
1947                 if (!oc) {
1948                         printk(KERN_ERR "SELinux:  unable to look up"
1949                                 " the initial SIDs list\n");
1950                         goto bad;
1951                 }
1952                 range = &oc->context[0].range;
1953                 rc = mls_range_set(c, range);
1954                 if (rc)
1955                         goto bad;
1956         }
1957 
1958         /* Check the validity of the new context. */
1959         if (!policydb_context_isvalid(args->newp, c)) {
1960                 rc = convert_context_handle_invalid_context(&oldc);
1961                 if (rc)
1962                         goto bad;
1963         }
1964 
1965         context_destroy(&oldc);
1966 
1967         rc = 0;
1968 out:
1969         return rc;
1970 bad:
1971         /* Map old representation to string and save it. */
1972         rc = context_struct_to_string(&oldc, &s, &len);
1973         if (rc)
1974                 return rc;
1975         context_destroy(&oldc);
1976         context_destroy(c);
1977         c->str = s;
1978         c->len = len;
1979         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1980                c->str);
1981         rc = 0;
1982         goto out;
1983 }
1984 
1985 static void security_load_policycaps(void)
1986 {
1987         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1988                                                   POLICYDB_CAPABILITY_NETPEER);
1989         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1990                                                   POLICYDB_CAPABILITY_OPENPERM);
1991         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1992                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1993 }
1994 
1995 static int security_preserve_bools(struct policydb *p);
1996 
1997 /**
1998  * security_load_policy - Load a security policy configuration.
1999  * @data: binary policy data
2000  * @len: length of data in bytes
2001  *
2002  * Load a new set of security policy configuration data,
2003  * validate it and convert the SID table as necessary.
2004  * This function will flush the access vector cache after
2005  * loading the new policy.
2006  */
2007 int security_load_policy(void *data, size_t len)
2008 {
2009         struct policydb *oldpolicydb, *newpolicydb;
2010         struct sidtab oldsidtab, newsidtab;
2011         struct selinux_mapping *oldmap, *map = NULL;
2012         struct convert_context_args args;
2013         u32 seqno;
2014         u16 map_size;
2015         int rc = 0;
2016         struct policy_file file = { data, len }, *fp = &file;
2017 
2018         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2019         if (!oldpolicydb) {
2020                 rc = -ENOMEM;
2021                 goto out;
2022         }
2023         newpolicydb = oldpolicydb + 1;
2024 
2025         if (!ss_initialized) {
2026                 avtab_cache_init();
2027                 rc = policydb_read(&policydb, fp);
2028                 if (rc) {
2029                         avtab_cache_destroy();
2030                         goto out;
2031                 }
2032 
2033                 policydb.len = len;
2034                 rc = selinux_set_mapping(&policydb, secclass_map,
2035                                          &current_mapping,
2036                                          &current_mapping_size);
2037                 if (rc) {
2038                         policydb_destroy(&policydb);
2039                         avtab_cache_destroy();
2040                         goto out;
2041                 }
2042 
2043                 rc = policydb_load_isids(&policydb, &sidtab);
2044                 if (rc) {
2045                         policydb_destroy(&policydb);
2046                         avtab_cache_destroy();
2047                         goto out;
2048                 }
2049 
2050                 security_load_policycaps();
2051                 ss_initialized = 1;
2052                 seqno = ++latest_granting;
2053                 selinux_complete_init();
2054                 avc_ss_reset(seqno);
2055                 selnl_notify_policyload(seqno);
2056                 selinux_status_update_policyload(seqno);
2057                 selinux_netlbl_cache_invalidate();
2058                 selinux_xfrm_notify_policyload();
2059                 goto out;
2060         }
2061 
2062 #if 0
2063         sidtab_hash_eval(&sidtab, "sids");
2064 #endif
2065 
2066         rc = policydb_read(newpolicydb, fp);
2067         if (rc)
2068                 goto out;
2069 
2070         newpolicydb->len = len;
2071         /* If switching between different policy types, log MLS status */
2072         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2073                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2074         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2075                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2076 
2077         rc = policydb_load_isids(newpolicydb, &newsidtab);
2078         if (rc) {
2079                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2080                 policydb_destroy(newpolicydb);
2081                 goto out;
2082         }
2083 
2084         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2085         if (rc)
2086                 goto err;
2087 
2088         rc = security_preserve_bools(newpolicydb);
2089         if (rc) {
2090                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2091                 goto err;
2092         }
2093 
2094         /* Clone the SID table. */
2095         sidtab_shutdown(&sidtab);
2096 
2097         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2098         if (rc)
2099                 goto err;
2100 
2101         /*
2102          * Convert the internal representations of contexts
2103          * in the new SID table.
2104          */
2105         args.oldp = &policydb;
2106         args.newp = newpolicydb;
2107         rc = sidtab_map(&newsidtab, convert_context, &args);
2108         if (rc) {
2109                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2110                         " representation of contexts in the new SID"
2111                         " table\n");
2112                 goto err;
2113         }
2114 
2115         /* Save the old policydb and SID table to free later. */
2116         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2117         sidtab_set(&oldsidtab, &sidtab);
2118 
2119         /* Install the new policydb and SID table. */
2120         write_lock_irq(&policy_rwlock);
2121         memcpy(&policydb, newpolicydb, sizeof(policydb));
2122         sidtab_set(&sidtab, &newsidtab);
2123         security_load_policycaps();
2124         oldmap = current_mapping;
2125         current_mapping = map;
2126         current_mapping_size = map_size;
2127         seqno = ++latest_granting;
2128         write_unlock_irq(&policy_rwlock);
2129 
2130         /* Free the old policydb and SID table. */
2131         policydb_destroy(oldpolicydb);
2132         sidtab_destroy(&oldsidtab);
2133         kfree(oldmap);
2134 
2135         avc_ss_reset(seqno);
2136         selnl_notify_policyload(seqno);
2137         selinux_status_update_policyload(seqno);
2138         selinux_netlbl_cache_invalidate();
2139         selinux_xfrm_notify_policyload();
2140 
2141         rc = 0;
2142         goto out;
2143 
2144 err:
2145         kfree(map);
2146         sidtab_destroy(&newsidtab);
2147         policydb_destroy(newpolicydb);
2148 
2149 out:
2150         kfree(oldpolicydb);
2151         return rc;
2152 }
2153 
2154 size_t security_policydb_len(void)
2155 {
2156         size_t len;
2157 
2158         read_lock(&policy_rwlock);
2159         len = policydb.len;
2160         read_unlock(&policy_rwlock);
2161 
2162         return len;
2163 }
2164 
2165 /**
2166  * security_port_sid - Obtain the SID for a port.
2167  * @protocol: protocol number
2168  * @port: port number
2169  * @out_sid: security identifier
2170  */
2171 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2172 {
2173         struct ocontext *c;
2174         int rc = 0;
2175 
2176         read_lock(&policy_rwlock);
2177 
2178         c = policydb.ocontexts[OCON_PORT];
2179         while (c) {
2180                 if (c->u.port.protocol == protocol &&
2181                     c->u.port.low_port <= port &&
2182                     c->u.port.high_port >= port)
2183                         break;
2184                 c = c->next;
2185         }
2186 
2187         if (c) {
2188                 if (!c->sid[0]) {
2189                         rc = sidtab_context_to_sid(&sidtab,
2190                                                    &c->context[0],
2191                                                    &c->sid[0]);
2192                         if (rc)
2193                                 goto out;
2194                 }
2195                 *out_sid = c->sid[0];
2196         } else {
2197                 *out_sid = SECINITSID_PORT;
2198         }
2199 
2200 out:
2201         read_unlock(&policy_rwlock);
2202         return rc;
2203 }
2204 
2205 /**
2206  * security_netif_sid - Obtain the SID for a network interface.
2207  * @name: interface name
2208  * @if_sid: interface SID
2209  */
2210 int security_netif_sid(char *name, u32 *if_sid)
2211 {
2212         int rc = 0;
2213         struct ocontext *c;
2214 
2215         read_lock(&policy_rwlock);
2216 
2217         c = policydb.ocontexts[OCON_NETIF];
2218         while (c) {
2219                 if (strcmp(name, c->u.name) == 0)
2220                         break;
2221                 c = c->next;
2222         }
2223 
2224         if (c) {
2225                 if (!c->sid[0] || !c->sid[1]) {
2226                         rc = sidtab_context_to_sid(&sidtab,
2227                                                   &c->context[0],
2228                                                   &c->sid[0]);
2229                         if (rc)
2230                                 goto out;
2231                         rc = sidtab_context_to_sid(&sidtab,
2232                                                    &c->context[1],
2233                                                    &c->sid[1]);
2234                         if (rc)
2235                                 goto out;
2236                 }
2237                 *if_sid = c->sid[0];
2238         } else
2239                 *if_sid = SECINITSID_NETIF;
2240 
2241 out:
2242         read_unlock(&policy_rwlock);
2243         return rc;
2244 }
2245 
2246 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2247 {
2248         int i, fail = 0;
2249 
2250         for (i = 0; i < 4; i++)
2251                 if (addr[i] != (input[i] & mask[i])) {
2252                         fail = 1;
2253                         break;
2254                 }
2255 
2256         return !fail;
2257 }
2258 
2259 /**
2260  * security_node_sid - Obtain the SID for a node (host).
2261  * @domain: communication domain aka address family
2262  * @addrp: address
2263  * @addrlen: address length in bytes
2264  * @out_sid: security identifier
2265  */
2266 int security_node_sid(u16 domain,
2267                       void *addrp,
2268                       u32 addrlen,
2269                       u32 *out_sid)
2270 {
2271         int rc;
2272         struct ocontext *c;
2273 
2274         read_lock(&policy_rwlock);
2275 
2276         switch (domain) {
2277         case AF_INET: {
2278                 u32 addr;
2279 
2280                 rc = -EINVAL;
2281                 if (addrlen != sizeof(u32))
2282                         goto out;
2283 
2284                 addr = *((u32 *)addrp);
2285 
2286                 c = policydb.ocontexts[OCON_NODE];
2287                 while (c) {
2288                         if (c->u.node.addr == (addr & c->u.node.mask))
2289                                 break;
2290                         c = c->next;
2291                 }
2292                 break;
2293         }
2294 
2295         case AF_INET6:
2296                 rc = -EINVAL;
2297                 if (addrlen != sizeof(u64) * 2)
2298                         goto out;
2299                 c = policydb.ocontexts[OCON_NODE6];
2300                 while (c) {
2301                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2302                                                 c->u.node6.mask))
2303                                 break;
2304                         c = c->next;
2305                 }
2306                 break;
2307 
2308         default:
2309                 rc = 0;
2310                 *out_sid = SECINITSID_NODE;
2311                 goto out;
2312         }
2313 
2314         if (c) {
2315                 if (!c->sid[0]) {
2316                         rc = sidtab_context_to_sid(&sidtab,
2317                                                    &c->context[0],
2318                                                    &c->sid[0]);
2319                         if (rc)
2320                                 goto out;
2321                 }
2322                 *out_sid = c->sid[0];
2323         } else {
2324                 *out_sid = SECINITSID_NODE;
2325         }
2326 
2327         rc = 0;
2328 out:
2329         read_unlock(&policy_rwlock);
2330         return rc;
2331 }
2332 
2333 #define SIDS_NEL 25
2334 
2335 /**
2336  * security_get_user_sids - Obtain reachable SIDs for a user.
2337  * @fromsid: starting SID
2338  * @username: username
2339  * @sids: array of reachable SIDs for user
2340  * @nel: number of elements in @sids
2341  *
2342  * Generate the set of SIDs for legal security contexts
2343  * for a given user that can be reached by @fromsid.
2344  * Set *@sids to point to a dynamically allocated
2345  * array containing the set of SIDs.  Set *@nel to the
2346  * number of elements in the array.
2347  */
2348 
2349 int security_get_user_sids(u32 fromsid,
2350                            char *username,
2351                            u32 **sids,
2352                            u32 *nel)
2353 {
2354         struct context *fromcon, usercon;
2355         u32 *mysids = NULL, *mysids2, sid;
2356         u32 mynel = 0, maxnel = SIDS_NEL;
2357         struct user_datum *user;
2358         struct role_datum *role;
2359         struct ebitmap_node *rnode, *tnode;
2360         int rc = 0, i, j;
2361 
2362         *sids = NULL;
2363         *nel = 0;
2364 
2365         if (!ss_initialized)
2366                 goto out;
2367 
2368         read_lock(&policy_rwlock);
2369 
2370         context_init(&usercon);
2371 
2372         rc = -EINVAL;
2373         fromcon = sidtab_search(&sidtab, fromsid);
2374         if (!fromcon)
2375                 goto out_unlock;
2376 
2377         rc = -EINVAL;
2378         user = hashtab_search(policydb.p_users.table, username);
2379         if (!user)
2380                 goto out_unlock;
2381 
2382         usercon.user = user->value;
2383 
2384         rc = -ENOMEM;
2385         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2386         if (!mysids)
2387                 goto out_unlock;
2388 
2389         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2390                 role = policydb.role_val_to_struct[i];
2391                 usercon.role = i + 1;
2392                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2393                         usercon.type = j + 1;
2394 
2395                         if (mls_setup_user_range(fromcon, user, &usercon))
2396                                 continue;
2397 
2398                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2399                         if (rc)
2400                                 goto out_unlock;
2401                         if (mynel < maxnel) {
2402                                 mysids[mynel++] = sid;
2403                         } else {
2404                                 rc = -ENOMEM;
2405                                 maxnel += SIDS_NEL;
2406                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2407                                 if (!mysids2)
2408                                         goto out_unlock;
2409                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2410                                 kfree(mysids);
2411                                 mysids = mysids2;
2412                                 mysids[mynel++] = sid;
2413                         }
2414                 }
2415         }
2416         rc = 0;
2417 out_unlock:
2418         read_unlock(&policy_rwlock);
2419         if (rc || !mynel) {
2420                 kfree(mysids);
2421                 goto out;
2422         }
2423 
2424         rc = -ENOMEM;
2425         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2426         if (!mysids2) {
2427                 kfree(mysids);
2428                 goto out;
2429         }
2430         for (i = 0, j = 0; i < mynel; i++) {
2431                 struct av_decision dummy_avd;
2432                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2433                                           SECCLASS_PROCESS, /* kernel value */
2434                                           PROCESS__TRANSITION, AVC_STRICT,
2435                                           &dummy_avd);
2436                 if (!rc)
2437                         mysids2[j++] = mysids[i];
2438                 cond_resched();
2439         }
2440         rc = 0;
2441         kfree(mysids);
2442         *sids = mysids2;
2443         *nel = j;
2444 out:
2445         return rc;
2446 }
2447 
2448 /**
2449  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2450  * @fstype: filesystem type
2451  * @path: path from root of mount
2452  * @sclass: file security class
2453  * @sid: SID for path
2454  *
2455  * Obtain a SID to use for a file in a filesystem that
2456  * cannot support xattr or use a fixed labeling behavior like
2457  * transition SIDs or task SIDs.
2458  *
2459  * The caller must acquire the policy_rwlock before calling this function.
2460  */
2461 static inline int __security_genfs_sid(const char *fstype,
2462                                        char *path,
2463                                        u16 orig_sclass,
2464                                        u32 *sid)
2465 {
2466         int len;
2467         u16 sclass;
2468         struct genfs *genfs;
2469         struct ocontext *c;
2470         int rc, cmp = 0;
2471 
2472         while (path[0] == '/' && path[1] == '/')
2473                 path++;
2474 
2475         sclass = unmap_class(orig_sclass);
2476         *sid = SECINITSID_UNLABELED;
2477 
2478         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2479                 cmp = strcmp(fstype, genfs->fstype);
2480                 if (cmp <= 0)
2481                         break;
2482         }
2483 
2484         rc = -ENOENT;
2485         if (!genfs || cmp)
2486                 goto out;
2487 
2488         for (c = genfs->head; c; c = c->next) {
2489                 len = strlen(c->u.name);
2490                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2491                     (strncmp(c->u.name, path, len) == 0))
2492                         break;
2493         }
2494 
2495         rc = -ENOENT;
2496         if (!c)
2497                 goto out;
2498 
2499         if (!c->sid[0]) {
2500                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2501                 if (rc)
2502                         goto out;
2503         }
2504 
2505         *sid = c->sid[0];
2506         rc = 0;
2507 out:
2508         return rc;
2509 }
2510 
2511 /**
2512  * security_genfs_sid - Obtain a SID for a file in a filesystem
2513  * @fstype: filesystem type
2514  * @path: path from root of mount
2515  * @sclass: file security class
2516  * @sid: SID for path
2517  *
2518  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2519  * it afterward.
2520  */
2521 int security_genfs_sid(const char *fstype,
2522                        char *path,
2523                        u16 orig_sclass,
2524                        u32 *sid)
2525 {
2526         int retval;
2527 
2528         read_lock(&policy_rwlock);
2529         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2530         read_unlock(&policy_rwlock);
2531         return retval;
2532 }
2533 
2534 /**
2535  * security_fs_use - Determine how to handle labeling for a filesystem.
2536  * @sb: superblock in question
2537  */
2538 int security_fs_use(struct super_block *sb)
2539 {
2540         int rc = 0;
2541         struct ocontext *c;
2542         struct superblock_security_struct *sbsec = sb->s_security;
2543         const char *fstype = sb->s_type->name;
2544 
2545         read_lock(&policy_rwlock);
2546 
2547         c = policydb.ocontexts[OCON_FSUSE];
2548         while (c) {
2549                 if (strcmp(fstype, c->u.name) == 0)
2550                         break;
2551                 c = c->next;
2552         }
2553 
2554         if (c) {
2555                 sbsec->behavior = c->v.behavior;
2556                 if (!c->sid[0]) {
2557                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2558                                                    &c->sid[0]);
2559                         if (rc)
2560                                 goto out;
2561                 }
2562                 sbsec->sid = c->sid[0];
2563         } else {
2564                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2565                                           &sbsec->sid);
2566                 if (rc) {
2567                         sbsec->behavior = SECURITY_FS_USE_NONE;
2568                         rc = 0;
2569                 } else {
2570                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2571                 }
2572         }
2573 
2574 out:
2575         read_unlock(&policy_rwlock);
2576         return rc;
2577 }
2578 
2579 int security_get_bools(int *len, char ***names, int **values)
2580 {
2581         int i, rc;
2582 
2583         read_lock(&policy_rwlock);
2584         *names = NULL;
2585         *values = NULL;
2586 
2587         rc = 0;
2588         *len = policydb.p_bools.nprim;
2589         if (!*len)
2590                 goto out;
2591 
2592         rc = -ENOMEM;
2593         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2594         if (!*names)
2595                 goto err;
2596 
2597         rc = -ENOMEM;
2598         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2599         if (!*values)
2600                 goto err;
2601 
2602         for (i = 0; i < *len; i++) {
2603                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2604 
2605                 rc = -ENOMEM;
2606                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2607                 if (!(*names)[i])
2608                         goto err;
2609         }
2610         rc = 0;
2611 out:
2612         read_unlock(&policy_rwlock);
2613         return rc;
2614 err:
2615         if (*names) {
2616                 for (i = 0; i < *len; i++)
2617                         kfree((*names)[i]);
2618         }
2619         kfree(*values);
2620         goto out;
2621 }
2622 
2623 
2624 int security_set_bools(int len, int *values)
2625 {
2626         int i, rc;
2627         int lenp, seqno = 0;
2628         struct cond_node *cur;
2629 
2630         write_lock_irq(&policy_rwlock);
2631 
2632         rc = -EFAULT;
2633         lenp = policydb.p_bools.nprim;
2634         if (len != lenp)
2635                 goto out;
2636 
2637         for (i = 0; i < len; i++) {
2638                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2639                         audit_log(current->audit_context, GFP_ATOMIC,
2640                                 AUDIT_MAC_CONFIG_CHANGE,
2641                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2642                                 sym_name(&policydb, SYM_BOOLS, i),
2643                                 !!values[i],
2644                                 policydb.bool_val_to_struct[i]->state,
2645                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2646                                 audit_get_sessionid(current));
2647                 }
2648                 if (values[i])
2649                         policydb.bool_val_to_struct[i]->state = 1;
2650                 else
2651                         policydb.bool_val_to_struct[i]->state = 0;
2652         }
2653 
2654         for (cur = policydb.cond_list; cur; cur = cur->next) {
2655                 rc = evaluate_cond_node(&policydb, cur);
2656                 if (rc)
2657                         goto out;
2658         }
2659 
2660         seqno = ++latest_granting;
2661         rc = 0;
2662 out:
2663         write_unlock_irq(&policy_rwlock);
2664         if (!rc) {
2665                 avc_ss_reset(seqno);
2666                 selnl_notify_policyload(seqno);
2667                 selinux_status_update_policyload(seqno);
2668                 selinux_xfrm_notify_policyload();
2669         }
2670         return rc;
2671 }
2672 
2673 int security_get_bool_value(int index)
2674 {
2675         int rc;
2676         int len;
2677 
2678         read_lock(&policy_rwlock);
2679 
2680         rc = -EFAULT;
2681         len = policydb.p_bools.nprim;
2682         if (index >= len)
2683                 goto out;
2684 
2685         rc = policydb.bool_val_to_struct[index]->state;
2686 out:
2687         read_unlock(&policy_rwlock);
2688         return rc;
2689 }
2690 
2691 static int security_preserve_bools(struct policydb *p)
2692 {
2693         int rc, nbools = 0, *bvalues = NULL, i;
2694         char **bnames = NULL;
2695         struct cond_bool_datum *booldatum;
2696         struct cond_node *cur;
2697 
2698         rc = security_get_bools(&nbools, &bnames, &bvalues);
2699         if (rc)
2700                 goto out;
2701         for (i = 0; i < nbools; i++) {
2702                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2703                 if (booldatum)
2704                         booldatum->state = bvalues[i];
2705         }
2706         for (cur = p->cond_list; cur; cur = cur->next) {
2707                 rc = evaluate_cond_node(p, cur);
2708                 if (rc)
2709                         goto out;
2710         }
2711 
2712 out:
2713         if (bnames) {
2714                 for (i = 0; i < nbools; i++)
2715                         kfree(bnames[i]);
2716         }
2717         kfree(bnames);
2718         kfree(bvalues);
2719         return rc;
2720 }
2721 
2722 /*
2723  * security_sid_mls_copy() - computes a new sid based on the given
2724  * sid and the mls portion of mls_sid.
2725  */
2726 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2727 {
2728         struct context *context1;
2729         struct context *context2;
2730         struct context newcon;
2731         char *s;
2732         u32 len;
2733         int rc;
2734 
2735         rc = 0;
2736         if (!ss_initialized || !policydb.mls_enabled) {
2737                 *new_sid = sid;
2738                 goto out;
2739         }
2740 
2741         context_init(&newcon);
2742 
2743         read_lock(&policy_rwlock);
2744 
2745         rc = -EINVAL;
2746         context1 = sidtab_search(&sidtab, sid);
2747         if (!context1) {
2748                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2749                         __func__, sid);
2750                 goto out_unlock;
2751         }
2752 
2753         rc = -EINVAL;
2754         context2 = sidtab_search(&sidtab, mls_sid);
2755         if (!context2) {
2756                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2757                         __func__, mls_sid);
2758                 goto out_unlock;
2759         }
2760 
2761         newcon.user = context1->user;
2762         newcon.role = context1->role;
2763         newcon.type = context1->type;
2764         rc = mls_context_cpy(&newcon, context2);
2765         if (rc)
2766                 goto out_unlock;
2767 
2768         /* Check the validity of the new context. */
2769         if (!policydb_context_isvalid(&policydb, &newcon)) {
2770                 rc = convert_context_handle_invalid_context(&newcon);
2771                 if (rc) {
2772                         if (!context_struct_to_string(&newcon, &s, &len)) {
2773                                 audit_log(current->audit_context,
2774                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2775                                           "op=security_sid_mls_copy "
2776                                           "invalid_context=%s", s);
2777                                 kfree(s);
2778                         }
2779                         goto out_unlock;
2780                 }
2781         }
2782 
2783         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2784 out_unlock:
2785         read_unlock(&policy_rwlock);
2786         context_destroy(&newcon);
2787 out:
2788         return rc;
2789 }
2790 
2791 /**
2792  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2793  * @nlbl_sid: NetLabel SID
2794  * @nlbl_type: NetLabel labeling protocol type
2795  * @xfrm_sid: XFRM SID
2796  *
2797  * Description:
2798  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2799  * resolved into a single SID it is returned via @peer_sid and the function
2800  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2801  * returns a negative value.  A table summarizing the behavior is below:
2802  *
2803  *                                 | function return |      @sid
2804  *   ------------------------------+-----------------+-----------------
2805  *   no peer labels                |        0        |    SECSID_NULL
2806  *   single peer label             |        0        |    <peer_label>
2807  *   multiple, consistent labels   |        0        |    <peer_label>
2808  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2809  *
2810  */
2811 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2812                                  u32 xfrm_sid,
2813                                  u32 *peer_sid)
2814 {
2815         int rc;
2816         struct context *nlbl_ctx;
2817         struct context *xfrm_ctx;
2818 
2819         *peer_sid = SECSID_NULL;
2820 
2821         /* handle the common (which also happens to be the set of easy) cases
2822          * right away, these two if statements catch everything involving a
2823          * single or absent peer SID/label */
2824         if (xfrm_sid == SECSID_NULL) {
2825                 *peer_sid = nlbl_sid;
2826                 return 0;
2827         }
2828         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2829          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2830          * is present */
2831         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2832                 *peer_sid = xfrm_sid;
2833                 return 0;
2834         }
2835 
2836         /* we don't need to check ss_initialized here since the only way both
2837          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2838          * security server was initialized and ss_initialized was true */
2839         if (!policydb.mls_enabled)
2840                 return 0;
2841 
2842         read_lock(&policy_rwlock);
2843 
2844         rc = -EINVAL;
2845         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2846         if (!nlbl_ctx) {
2847                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2848                        __func__, nlbl_sid);
2849                 goto out;
2850         }
2851         rc = -EINVAL;
2852         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2853         if (!xfrm_ctx) {
2854                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2855                        __func__, xfrm_sid);
2856                 goto out;
2857         }
2858         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2859         if (rc)
2860                 goto out;
2861 
2862         /* at present NetLabel SIDs/labels really only carry MLS
2863          * information so if the MLS portion of the NetLabel SID
2864          * matches the MLS portion of the labeled XFRM SID/label
2865          * then pass along the XFRM SID as it is the most
2866          * expressive */
2867         *peer_sid = xfrm_sid;
2868 out:
2869         read_unlock(&policy_rwlock);
2870         return rc;
2871 }
2872 
2873 static int get_classes_callback(void *k, void *d, void *args)
2874 {
2875         struct class_datum *datum = d;
2876         char *name = k, **classes = args;
2877         int value = datum->value - 1;
2878 
2879         classes[value] = kstrdup(name, GFP_ATOMIC);
2880         if (!classes[value])
2881                 return -ENOMEM;
2882 
2883         return 0;
2884 }
2885 
2886 int security_get_classes(char ***classes, int *nclasses)
2887 {
2888         int rc;
2889 
2890         read_lock(&policy_rwlock);
2891 
2892         rc = -ENOMEM;
2893         *nclasses = policydb.p_classes.nprim;
2894         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2895         if (!*classes)
2896                 goto out;
2897 
2898         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2899                         *classes);
2900         if (rc) {
2901                 int i;
2902                 for (i = 0; i < *nclasses; i++)
2903                         kfree((*classes)[i]);
2904                 kfree(*classes);
2905         }
2906 
2907 out:
2908         read_unlock(&policy_rwlock);
2909         return rc;
2910 }
2911 
2912 static int get_permissions_callback(void *k, void *d, void *args)
2913 {
2914         struct perm_datum *datum = d;
2915         char *name = k, **perms = args;
2916         int value = datum->value - 1;
2917 
2918         perms[value] = kstrdup(name, GFP_ATOMIC);
2919         if (!perms[value])
2920                 return -ENOMEM;
2921 
2922         return 0;
2923 }
2924 
2925 int security_get_permissions(char *class, char ***perms, int *nperms)
2926 {
2927         int rc, i;
2928         struct class_datum *match;
2929 
2930         read_lock(&policy_rwlock);
2931 
2932         rc = -EINVAL;
2933         match = hashtab_search(policydb.p_classes.table, class);
2934         if (!match) {
2935                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2936                         __func__, class);
2937                 goto out;
2938         }
2939 
2940         rc = -ENOMEM;
2941         *nperms = match->permissions.nprim;
2942         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2943         if (!*perms)
2944                 goto out;
2945 
2946         if (match->comdatum) {
2947                 rc = hashtab_map(match->comdatum->permissions.table,
2948                                 get_permissions_callback, *perms);
2949                 if (rc)
2950                         goto err;
2951         }
2952 
2953         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2954                         *perms);
2955         if (rc)
2956                 goto err;
2957 
2958 out:
2959         read_unlock(&policy_rwlock);
2960         return rc;
2961 
2962 err:
2963         read_unlock(&policy_rwlock);
2964         for (i = 0; i < *nperms; i++)
2965                 kfree((*perms)[i]);
2966         kfree(*perms);
2967         return rc;
2968 }
2969 
2970 int security_get_reject_unknown(void)
2971 {
2972         return policydb.reject_unknown;
2973 }
2974 
2975 int security_get_allow_unknown(void)
2976 {
2977         return policydb.allow_unknown;
2978 }
2979 
2980 /**
2981  * security_policycap_supported - Check for a specific policy capability
2982  * @req_cap: capability
2983  *
2984  * Description:
2985  * This function queries the currently loaded policy to see if it supports the
2986  * capability specified by @req_cap.  Returns true (1) if the capability is
2987  * supported, false (0) if it isn't supported.
2988  *
2989  */
2990 int security_policycap_supported(unsigned int req_cap)
2991 {
2992         int rc;
2993 
2994         read_lock(&policy_rwlock);
2995         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2996         read_unlock(&policy_rwlock);
2997 
2998         return rc;
2999 }
3000 
3001 struct selinux_audit_rule {
3002         u32 au_seqno;
3003         struct context au_ctxt;
3004 };
3005 
3006 void selinux_audit_rule_free(void *vrule)
3007 {
3008         struct selinux_audit_rule *rule = vrule;
3009 
3010         if (rule) {
3011                 context_destroy(&rule->au_ctxt);
3012                 kfree(rule);
3013         }
3014 }
3015 
3016 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3017 {
3018         struct selinux_audit_rule *tmprule;
3019         struct role_datum *roledatum;
3020         struct type_datum *typedatum;
3021         struct user_datum *userdatum;
3022         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3023         int rc = 0;
3024 
3025         *rule = NULL;
3026 
3027         if (!ss_initialized)
3028                 return -EOPNOTSUPP;
3029 
3030         switch (field) {
3031         case AUDIT_SUBJ_USER:
3032         case AUDIT_SUBJ_ROLE:
3033         case AUDIT_SUBJ_TYPE:
3034         case AUDIT_OBJ_USER:
3035         case AUDIT_OBJ_ROLE:
3036         case AUDIT_OBJ_TYPE:
3037                 /* only 'equals' and 'not equals' fit user, role, and type */
3038                 if (op != Audit_equal && op != Audit_not_equal)
3039                         return -EINVAL;
3040                 break;
3041         case AUDIT_SUBJ_SEN:
3042         case AUDIT_SUBJ_CLR:
3043         case AUDIT_OBJ_LEV_LOW:
3044         case AUDIT_OBJ_LEV_HIGH:
3045                 /* we do not allow a range, indicated by the presence of '-' */
3046                 if (strchr(rulestr, '-'))
3047                         return -EINVAL;
3048                 break;
3049         default:
3050                 /* only the above fields are valid */
3051                 return -EINVAL;
3052         }
3053 
3054         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3055         if (!tmprule)
3056                 return -ENOMEM;
3057 
3058         context_init(&tmprule->au_ctxt);
3059 
3060         read_lock(&policy_rwlock);
3061 
3062         tmprule->au_seqno = latest_granting;
3063 
3064         switch (field) {
3065         case AUDIT_SUBJ_USER:
3066         case AUDIT_OBJ_USER:
3067                 rc = -EINVAL;
3068                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3069                 if (!userdatum)
3070                         goto out;
3071                 tmprule->au_ctxt.user = userdatum->value;
3072                 break;
3073         case AUDIT_SUBJ_ROLE:
3074         case AUDIT_OBJ_ROLE:
3075                 rc = -EINVAL;
3076                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3077                 if (!roledatum)
3078                         goto out;
3079                 tmprule->au_ctxt.role = roledatum->value;
3080                 break;
3081         case AUDIT_SUBJ_TYPE:
3082         case AUDIT_OBJ_TYPE:
3083                 rc = -EINVAL;
3084                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3085                 if (!typedatum)
3086                         goto out;
3087                 tmprule->au_ctxt.type = typedatum->value;
3088                 break;
3089         case AUDIT_SUBJ_SEN:
3090         case AUDIT_SUBJ_CLR:
3091         case AUDIT_OBJ_LEV_LOW:
3092         case AUDIT_OBJ_LEV_HIGH:
3093                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3094                 if (rc)
3095                         goto out;
3096                 break;
3097         }
3098         rc = 0;
3099 out:
3100         read_unlock(&policy_rwlock);
3101 
3102         if (rc) {
3103                 selinux_audit_rule_free(tmprule);
3104                 tmprule = NULL;
3105         }
3106 
3107         *rule = tmprule;
3108 
3109         return rc;
3110 }
3111 
3112 /* Check to see if the rule contains any selinux fields */
3113 int selinux_audit_rule_known(struct audit_krule *rule)
3114 {
3115         int i;
3116 
3117         for (i = 0; i < rule->field_count; i++) {
3118                 struct audit_field *f = &rule->fields[i];
3119                 switch (f->type) {
3120                 case AUDIT_SUBJ_USER:
3121                 case AUDIT_SUBJ_ROLE:
3122                 case AUDIT_SUBJ_TYPE:
3123                 case AUDIT_SUBJ_SEN:
3124                 case AUDIT_SUBJ_CLR:
3125                 case AUDIT_OBJ_USER:
3126                 case AUDIT_OBJ_ROLE:
3127                 case AUDIT_OBJ_TYPE:
3128                 case AUDIT_OBJ_LEV_LOW:
3129                 case AUDIT_OBJ_LEV_HIGH:
3130                         return 1;
3131                 }
3132         }
3133 
3134         return 0;
3135 }
3136 
3137 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3138                              struct audit_context *actx)
3139 {
3140         struct context *ctxt;
3141         struct mls_level *level;
3142         struct selinux_audit_rule *rule = vrule;
3143         int match = 0;
3144 
3145         if (unlikely(!rule)) {
3146                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3147                 return -ENOENT;
3148         }
3149 
3150         read_lock(&policy_rwlock);
3151 
3152         if (rule->au_seqno < latest_granting) {
3153                 match = -ESTALE;
3154                 goto out;
3155         }
3156 
3157         ctxt = sidtab_search(&sidtab, sid);
3158         if (unlikely(!ctxt)) {
3159                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3160                           sid);
3161                 match = -ENOENT;
3162                 goto out;
3163         }
3164 
3165         /* a field/op pair that is not caught here will simply fall through
3166            without a match */
3167         switch (field) {
3168         case AUDIT_SUBJ_USER:
3169         case AUDIT_OBJ_USER:
3170                 switch (op) {
3171                 case Audit_equal:
3172                         match = (ctxt->user == rule->au_ctxt.user);
3173                         break;
3174                 case Audit_not_equal:
3175                         match = (ctxt->user != rule->au_ctxt.user);
3176                         break;
3177                 }
3178                 break;
3179         case AUDIT_SUBJ_ROLE:
3180         case AUDIT_OBJ_ROLE:
3181                 switch (op) {
3182                 case Audit_equal:
3183                         match = (ctxt->role == rule->au_ctxt.role);
3184                         break;
3185                 case Audit_not_equal:
3186                         match = (ctxt->role != rule->au_ctxt.role);
3187                         break;
3188                 }
3189                 break;
3190         case AUDIT_SUBJ_TYPE:
3191         case AUDIT_OBJ_TYPE:
3192                 switch (op) {
3193                 case Audit_equal:
3194                         match = (ctxt->type == rule->au_ctxt.type);
3195                         break;
3196                 case Audit_not_equal:
3197                         match = (ctxt->type != rule->au_ctxt.type);
3198                         break;
3199                 }
3200                 break;
3201         case AUDIT_SUBJ_SEN:
3202         case AUDIT_SUBJ_CLR:
3203         case AUDIT_OBJ_LEV_LOW:
3204         case AUDIT_OBJ_LEV_HIGH:
3205                 level = ((field == AUDIT_SUBJ_SEN ||
3206                           field == AUDIT_OBJ_LEV_LOW) ?
3207                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3208                 switch (op) {
3209                 case Audit_equal:
3210                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3211                                              level);
3212                         break;
3213                 case Audit_not_equal:
3214                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3215                                               level);
3216                         break;
3217                 case Audit_lt:
3218                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3219                                                level) &&
3220                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3221                                                level));
3222                         break;
3223                 case Audit_le:
3224                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3225                                               level);
3226                         break;
3227                 case Audit_gt:
3228                         match = (mls_level_dom(level,
3229                                               &rule->au_ctxt.range.level[0]) &&
3230                                  !mls_level_eq(level,
3231                                                &rule->au_ctxt.range.level[0]));
3232                         break;
3233                 case Audit_ge:
3234                         match = mls_level_dom(level,
3235                                               &rule->au_ctxt.range.level[0]);
3236                         break;
3237                 }
3238         }
3239 
3240 out:
3241         read_unlock(&policy_rwlock);
3242         return match;
3243 }
3244 
3245 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3246 
3247 static int aurule_avc_callback(u32 event)
3248 {
3249         int err = 0;
3250 
3251         if (event == AVC_CALLBACK_RESET && aurule_callback)
3252                 err = aurule_callback();
3253         return err;
3254 }
3255 
3256 static int __init aurule_init(void)
3257 {
3258         int err;
3259 
3260         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3261         if (err)
3262                 panic("avc_add_callback() failed, error %d\n", err);
3263 
3264         return err;
3265 }
3266 __initcall(aurule_init);
3267 
3268 #ifdef CONFIG_NETLABEL
3269 /**
3270  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3271  * @secattr: the NetLabel packet security attributes
3272  * @sid: the SELinux SID
3273  *
3274  * Description:
3275  * Attempt to cache the context in @ctx, which was derived from the packet in
3276  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3277  * already been initialized.
3278  *
3279  */
3280 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3281                                       u32 sid)
3282 {
3283         u32 *sid_cache;
3284 
3285         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3286         if (sid_cache == NULL)
3287                 return;
3288         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3289         if (secattr->cache == NULL) {
3290                 kfree(sid_cache);
3291                 return;
3292         }
3293 
3294         *sid_cache = sid;
3295         secattr->cache->free = kfree;
3296         secattr->cache->data = sid_cache;
3297         secattr->flags |= NETLBL_SECATTR_CACHE;
3298 }
3299 
3300 /**
3301  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3302  * @secattr: the NetLabel packet security attributes
3303  * @sid: the SELinux SID
3304  *
3305  * Description:
3306  * Convert the given NetLabel security attributes in @secattr into a
3307  * SELinux SID.  If the @secattr field does not contain a full SELinux
3308  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3309  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3310  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3311  * conversion for future lookups.  Returns zero on success, negative values on
3312  * failure.
3313  *
3314  */
3315 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3316                                    u32 *sid)
3317 {
3318         int rc;
3319         struct context *ctx;
3320         struct context ctx_new;
3321 
3322         if (!ss_initialized) {
3323                 *sid = SECSID_NULL;
3324                 return 0;
3325         }
3326 
3327         read_lock(&policy_rwlock);
3328 
3329         if (secattr->flags & NETLBL_SECATTR_CACHE)
3330                 *sid = *(u32 *)secattr->cache->data;
3331         else if (secattr->flags & NETLBL_SECATTR_SECID)
3332                 *sid = secattr->attr.secid;
3333         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3334                 rc = -EIDRM;
3335                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3336                 if (ctx == NULL)
3337                         goto out;
3338 
3339                 context_init(&ctx_new);
3340                 ctx_new.user = ctx->user;
3341                 ctx_new.role = ctx->role;
3342                 ctx_new.type = ctx->type;
3343                 mls_import_netlbl_lvl(&ctx_new, secattr);
3344                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3345                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3346                         if (rc)
3347                                 goto out;
3348                 }
3349                 rc = -EIDRM;
3350                 if (!mls_context_isvalid(&policydb, &ctx_new))
3351                         goto out_free;
3352 
3353                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3354                 if (rc)
3355                         goto out_free;
3356 
3357                 security_netlbl_cache_add(secattr, *sid);
3358 
3359                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3360         } else
3361                 *sid = SECSID_NULL;
3362 
3363         read_unlock(&policy_rwlock);
3364         return 0;
3365 out_free:
3366         ebitmap_destroy(&ctx_new.range.level[0].cat);
3367 out:
3368         read_unlock(&policy_rwlock);
3369         return rc;
3370 }
3371 
3372 /**
3373  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3374  * @sid: the SELinux SID
3375  * @secattr: the NetLabel packet security attributes
3376  *
3377  * Description:
3378  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3379  * Returns zero on success, negative values on failure.
3380  *
3381  */
3382 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3383 {
3384         int rc;
3385         struct context *ctx;
3386 
3387         if (!ss_initialized)
3388                 return 0;
3389 
3390         read_lock(&policy_rwlock);
3391 
3392         rc = -ENOENT;
3393         ctx = sidtab_search(&sidtab, sid);
3394         if (ctx == NULL)
3395                 goto out;
3396 
3397         rc = -ENOMEM;
3398         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3399                                   GFP_ATOMIC);
3400         if (secattr->domain == NULL)
3401                 goto out;
3402 
3403         secattr->attr.secid = sid;
3404         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3405         mls_export_netlbl_lvl(ctx, secattr);
3406         rc = mls_export_netlbl_cat(ctx, secattr);
3407 out:
3408         read_unlock(&policy_rwlock);
3409         return rc;
3410 }
3411 #endif /* CONFIG_NETLABEL */
3412 
3413 /**
3414  * security_read_policy - read the policy.
3415  * @data: binary policy data
3416  * @len: length of data in bytes
3417  *
3418  */
3419 int security_read_policy(void **data, size_t *len)
3420 {
3421         int rc;
3422         struct policy_file fp;
3423 
3424         if (!ss_initialized)
3425                 return -EINVAL;
3426 
3427         *len = security_policydb_len();
3428 
3429         *data = vmalloc_user(*len);
3430         if (!*data)
3431                 return -ENOMEM;
3432 
3433         fp.data = *data;
3434         fp.len = *len;
3435 
3436         read_lock(&policy_rwlock);
3437         rc = policydb_write(&policydb, &fp);
3438         read_unlock(&policy_rwlock);
3439 
3440         if (rc)
3441                 return rc;
3442 
3443         *len = (unsigned long)fp.data - (unsigned long)*data;
3444         return 0;
3445 
3446 }
3447 

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