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Linux/security/selinux/ss/services.c

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  1 /*
  2  * Implementation of the security services.
  3  *
  4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
  5  *           James Morris <jmorris@redhat.com>
  6  *
  7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
  8  *
  9  *      Support for enhanced MLS infrastructure.
 10  *      Support for context based audit filters.
 11  *
 12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 13  *
 14  *      Added conditional policy language extensions
 15  *
 16  * Updated: Hewlett-Packard <paul@paul-moore.com>
 17  *
 18  *      Added support for NetLabel
 19  *      Added support for the policy capability bitmap
 20  *
 21  * Updated: Chad Sellers <csellers@tresys.com>
 22  *
 23  *  Added validation of kernel classes and permissions
 24  *
 25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
 26  *
 27  *  Added support for bounds domain and audit messaged on masked permissions
 28  *
 29  * Updated: Guido Trentalancia <guido@trentalancia.com>
 30  *
 31  *  Added support for runtime switching of the policy type
 32  *
 33  * Copyright (C) 2008, 2009 NEC Corporation
 34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
 35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
 36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
 37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
 38  *      This program is free software; you can redistribute it and/or modify
 39  *      it under the terms of the GNU General Public License as published by
 40  *      the Free Software Foundation, version 2.
 41  */
 42 #include <linux/kernel.h>
 43 #include <linux/slab.h>
 44 #include <linux/string.h>
 45 #include <linux/spinlock.h>
 46 #include <linux/rcupdate.h>
 47 #include <linux/errno.h>
 48 #include <linux/in.h>
 49 #include <linux/sched.h>
 50 #include <linux/audit.h>
 51 #include <linux/mutex.h>
 52 #include <linux/selinux.h>
 53 #include <linux/flex_array.h>
 54 #include <linux/vmalloc.h>
 55 #include <net/netlabel.h>
 56 
 57 #include "flask.h"
 58 #include "avc.h"
 59 #include "avc_ss.h"
 60 #include "security.h"
 61 #include "context.h"
 62 #include "policydb.h"
 63 #include "sidtab.h"
 64 #include "services.h"
 65 #include "conditional.h"
 66 #include "mls.h"
 67 #include "objsec.h"
 68 #include "netlabel.h"
 69 #include "xfrm.h"
 70 #include "ebitmap.h"
 71 #include "audit.h"
 72 
 73 int selinux_policycap_netpeer;
 74 int selinux_policycap_openperm;
 75 
 76 static DEFINE_RWLOCK(policy_rwlock);
 77 
 78 static struct sidtab sidtab;
 79 struct policydb policydb;
 80 int ss_initialized;
 81 
 82 /*
 83  * The largest sequence number that has been used when
 84  * providing an access decision to the access vector cache.
 85  * The sequence number only changes when a policy change
 86  * occurs.
 87  */
 88 static u32 latest_granting;
 89 
 90 /* Forward declaration. */
 91 static int context_struct_to_string(struct context *context, char **scontext,
 92                                     u32 *scontext_len);
 93 
 94 static void context_struct_compute_av(struct context *scontext,
 95                                       struct context *tcontext,
 96                                       u16 tclass,
 97                                       struct av_decision *avd);
 98 
 99 struct selinux_mapping {
100         u16 value; /* policy value */
101         unsigned num_perms;
102         u32 perms[sizeof(u32) * 8];
103 };
104 
105 static struct selinux_mapping *current_mapping;
106 static u16 current_mapping_size;
107 
108 static int selinux_set_mapping(struct policydb *pol,
109                                struct security_class_mapping *map,
110                                struct selinux_mapping **out_map_p,
111                                u16 *out_map_size)
112 {
113         struct selinux_mapping *out_map = NULL;
114         size_t size = sizeof(struct selinux_mapping);
115         u16 i, j;
116         unsigned k;
117         bool print_unknown_handle = false;
118 
119         /* Find number of classes in the input mapping */
120         if (!map)
121                 return -EINVAL;
122         i = 0;
123         while (map[i].name)
124                 i++;
125 
126         /* Allocate space for the class records, plus one for class zero */
127         out_map = kcalloc(++i, size, GFP_ATOMIC);
128         if (!out_map)
129                 return -ENOMEM;
130 
131         /* Store the raw class and permission values */
132         j = 0;
133         while (map[j].name) {
134                 struct security_class_mapping *p_in = map + (j++);
135                 struct selinux_mapping *p_out = out_map + j;
136 
137                 /* An empty class string skips ahead */
138                 if (!strcmp(p_in->name, "")) {
139                         p_out->num_perms = 0;
140                         continue;
141                 }
142 
143                 p_out->value = string_to_security_class(pol, p_in->name);
144                 if (!p_out->value) {
145                         printk(KERN_INFO
146                                "SELinux:  Class %s not defined in policy.\n",
147                                p_in->name);
148                         if (pol->reject_unknown)
149                                 goto err;
150                         p_out->num_perms = 0;
151                         print_unknown_handle = true;
152                         continue;
153                 }
154 
155                 k = 0;
156                 while (p_in->perms && p_in->perms[k]) {
157                         /* An empty permission string skips ahead */
158                         if (!*p_in->perms[k]) {
159                                 k++;
160                                 continue;
161                         }
162                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
163                                                             p_in->perms[k]);
164                         if (!p_out->perms[k]) {
165                                 printk(KERN_INFO
166                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
167                                        p_in->perms[k], p_in->name);
168                                 if (pol->reject_unknown)
169                                         goto err;
170                                 print_unknown_handle = true;
171                         }
172 
173                         k++;
174                 }
175                 p_out->num_perms = k;
176         }
177 
178         if (print_unknown_handle)
179                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
180                        pol->allow_unknown ? "allowed" : "denied");
181 
182         *out_map_p = out_map;
183         *out_map_size = i;
184         return 0;
185 err:
186         kfree(out_map);
187         return -EINVAL;
188 }
189 
190 /*
191  * Get real, policy values from mapped values
192  */
193 
194 static u16 unmap_class(u16 tclass)
195 {
196         if (tclass < current_mapping_size)
197                 return current_mapping[tclass].value;
198 
199         return tclass;
200 }
201 
202 /*
203  * Get kernel value for class from its policy value
204  */
205 static u16 map_class(u16 pol_value)
206 {
207         u16 i;
208 
209         for (i = 1; i < current_mapping_size; i++) {
210                 if (current_mapping[i].value == pol_value)
211                         return i;
212         }
213 
214         return SECCLASS_NULL;
215 }
216 
217 static void map_decision(u16 tclass, struct av_decision *avd,
218                          int allow_unknown)
219 {
220         if (tclass < current_mapping_size) {
221                 unsigned i, n = current_mapping[tclass].num_perms;
222                 u32 result;
223 
224                 for (i = 0, result = 0; i < n; i++) {
225                         if (avd->allowed & current_mapping[tclass].perms[i])
226                                 result |= 1<<i;
227                         if (allow_unknown && !current_mapping[tclass].perms[i])
228                                 result |= 1<<i;
229                 }
230                 avd->allowed = result;
231 
232                 for (i = 0, result = 0; i < n; i++)
233                         if (avd->auditallow & current_mapping[tclass].perms[i])
234                                 result |= 1<<i;
235                 avd->auditallow = result;
236 
237                 for (i = 0, result = 0; i < n; i++) {
238                         if (avd->auditdeny & current_mapping[tclass].perms[i])
239                                 result |= 1<<i;
240                         if (!allow_unknown && !current_mapping[tclass].perms[i])
241                                 result |= 1<<i;
242                 }
243                 /*
244                  * In case the kernel has a bug and requests a permission
245                  * between num_perms and the maximum permission number, we
246                  * should audit that denial
247                  */
248                 for (; i < (sizeof(u32)*8); i++)
249                         result |= 1<<i;
250                 avd->auditdeny = result;
251         }
252 }
253 
254 int security_mls_enabled(void)
255 {
256         return policydb.mls_enabled;
257 }
258 
259 /*
260  * Return the boolean value of a constraint expression
261  * when it is applied to the specified source and target
262  * security contexts.
263  *
264  * xcontext is a special beast...  It is used by the validatetrans rules
265  * only.  For these rules, scontext is the context before the transition,
266  * tcontext is the context after the transition, and xcontext is the context
267  * of the process performing the transition.  All other callers of
268  * constraint_expr_eval should pass in NULL for xcontext.
269  */
270 static int constraint_expr_eval(struct context *scontext,
271                                 struct context *tcontext,
272                                 struct context *xcontext,
273                                 struct constraint_expr *cexpr)
274 {
275         u32 val1, val2;
276         struct context *c;
277         struct role_datum *r1, *r2;
278         struct mls_level *l1, *l2;
279         struct constraint_expr *e;
280         int s[CEXPR_MAXDEPTH];
281         int sp = -1;
282 
283         for (e = cexpr; e; e = e->next) {
284                 switch (e->expr_type) {
285                 case CEXPR_NOT:
286                         BUG_ON(sp < 0);
287                         s[sp] = !s[sp];
288                         break;
289                 case CEXPR_AND:
290                         BUG_ON(sp < 1);
291                         sp--;
292                         s[sp] &= s[sp + 1];
293                         break;
294                 case CEXPR_OR:
295                         BUG_ON(sp < 1);
296                         sp--;
297                         s[sp] |= s[sp + 1];
298                         break;
299                 case CEXPR_ATTR:
300                         if (sp == (CEXPR_MAXDEPTH - 1))
301                                 return 0;
302                         switch (e->attr) {
303                         case CEXPR_USER:
304                                 val1 = scontext->user;
305                                 val2 = tcontext->user;
306                                 break;
307                         case CEXPR_TYPE:
308                                 val1 = scontext->type;
309                                 val2 = tcontext->type;
310                                 break;
311                         case CEXPR_ROLE:
312                                 val1 = scontext->role;
313                                 val2 = tcontext->role;
314                                 r1 = policydb.role_val_to_struct[val1 - 1];
315                                 r2 = policydb.role_val_to_struct[val2 - 1];
316                                 switch (e->op) {
317                                 case CEXPR_DOM:
318                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
319                                                                   val2 - 1);
320                                         continue;
321                                 case CEXPR_DOMBY:
322                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
323                                                                   val1 - 1);
324                                         continue;
325                                 case CEXPR_INCOMP:
326                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
327                                                                     val2 - 1) &&
328                                                    !ebitmap_get_bit(&r2->dominates,
329                                                                     val1 - 1));
330                                         continue;
331                                 default:
332                                         break;
333                                 }
334                                 break;
335                         case CEXPR_L1L2:
336                                 l1 = &(scontext->range.level[0]);
337                                 l2 = &(tcontext->range.level[0]);
338                                 goto mls_ops;
339                         case CEXPR_L1H2:
340                                 l1 = &(scontext->range.level[0]);
341                                 l2 = &(tcontext->range.level[1]);
342                                 goto mls_ops;
343                         case CEXPR_H1L2:
344                                 l1 = &(scontext->range.level[1]);
345                                 l2 = &(tcontext->range.level[0]);
346                                 goto mls_ops;
347                         case CEXPR_H1H2:
348                                 l1 = &(scontext->range.level[1]);
349                                 l2 = &(tcontext->range.level[1]);
350                                 goto mls_ops;
351                         case CEXPR_L1H1:
352                                 l1 = &(scontext->range.level[0]);
353                                 l2 = &(scontext->range.level[1]);
354                                 goto mls_ops;
355                         case CEXPR_L2H2:
356                                 l1 = &(tcontext->range.level[0]);
357                                 l2 = &(tcontext->range.level[1]);
358                                 goto mls_ops;
359 mls_ops:
360                         switch (e->op) {
361                         case CEXPR_EQ:
362                                 s[++sp] = mls_level_eq(l1, l2);
363                                 continue;
364                         case CEXPR_NEQ:
365                                 s[++sp] = !mls_level_eq(l1, l2);
366                                 continue;
367                         case CEXPR_DOM:
368                                 s[++sp] = mls_level_dom(l1, l2);
369                                 continue;
370                         case CEXPR_DOMBY:
371                                 s[++sp] = mls_level_dom(l2, l1);
372                                 continue;
373                         case CEXPR_INCOMP:
374                                 s[++sp] = mls_level_incomp(l2, l1);
375                                 continue;
376                         default:
377                                 BUG();
378                                 return 0;
379                         }
380                         break;
381                         default:
382                                 BUG();
383                                 return 0;
384                         }
385 
386                         switch (e->op) {
387                         case CEXPR_EQ:
388                                 s[++sp] = (val1 == val2);
389                                 break;
390                         case CEXPR_NEQ:
391                                 s[++sp] = (val1 != val2);
392                                 break;
393                         default:
394                                 BUG();
395                                 return 0;
396                         }
397                         break;
398                 case CEXPR_NAMES:
399                         if (sp == (CEXPR_MAXDEPTH-1))
400                                 return 0;
401                         c = scontext;
402                         if (e->attr & CEXPR_TARGET)
403                                 c = tcontext;
404                         else if (e->attr & CEXPR_XTARGET) {
405                                 c = xcontext;
406                                 if (!c) {
407                                         BUG();
408                                         return 0;
409                                 }
410                         }
411                         if (e->attr & CEXPR_USER)
412                                 val1 = c->user;
413                         else if (e->attr & CEXPR_ROLE)
414                                 val1 = c->role;
415                         else if (e->attr & CEXPR_TYPE)
416                                 val1 = c->type;
417                         else {
418                                 BUG();
419                                 return 0;
420                         }
421 
422                         switch (e->op) {
423                         case CEXPR_EQ:
424                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
425                                 break;
426                         case CEXPR_NEQ:
427                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
428                                 break;
429                         default:
430                                 BUG();
431                                 return 0;
432                         }
433                         break;
434                 default:
435                         BUG();
436                         return 0;
437                 }
438         }
439 
440         BUG_ON(sp != 0);
441         return s[0];
442 }
443 
444 /*
445  * security_dump_masked_av - dumps masked permissions during
446  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
447  */
448 static int dump_masked_av_helper(void *k, void *d, void *args)
449 {
450         struct perm_datum *pdatum = d;
451         char **permission_names = args;
452 
453         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
454 
455         permission_names[pdatum->value - 1] = (char *)k;
456 
457         return 0;
458 }
459 
460 static void security_dump_masked_av(struct context *scontext,
461                                     struct context *tcontext,
462                                     u16 tclass,
463                                     u32 permissions,
464                                     const char *reason)
465 {
466         struct common_datum *common_dat;
467         struct class_datum *tclass_dat;
468         struct audit_buffer *ab;
469         char *tclass_name;
470         char *scontext_name = NULL;
471         char *tcontext_name = NULL;
472         char *permission_names[32];
473         int index;
474         u32 length;
475         bool need_comma = false;
476 
477         if (!permissions)
478                 return;
479 
480         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
481         tclass_dat = policydb.class_val_to_struct[tclass - 1];
482         common_dat = tclass_dat->comdatum;
483 
484         /* init permission_names */
485         if (common_dat &&
486             hashtab_map(common_dat->permissions.table,
487                         dump_masked_av_helper, permission_names) < 0)
488                 goto out;
489 
490         if (hashtab_map(tclass_dat->permissions.table,
491                         dump_masked_av_helper, permission_names) < 0)
492                 goto out;
493 
494         /* get scontext/tcontext in text form */
495         if (context_struct_to_string(scontext,
496                                      &scontext_name, &length) < 0)
497                 goto out;
498 
499         if (context_struct_to_string(tcontext,
500                                      &tcontext_name, &length) < 0)
501                 goto out;
502 
503         /* audit a message */
504         ab = audit_log_start(current->audit_context,
505                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
506         if (!ab)
507                 goto out;
508 
509         audit_log_format(ab, "op=security_compute_av reason=%s "
510                          "scontext=%s tcontext=%s tclass=%s perms=",
511                          reason, scontext_name, tcontext_name, tclass_name);
512 
513         for (index = 0; index < 32; index++) {
514                 u32 mask = (1 << index);
515 
516                 if ((mask & permissions) == 0)
517                         continue;
518 
519                 audit_log_format(ab, "%s%s",
520                                  need_comma ? "," : "",
521                                  permission_names[index]
522                                  ? permission_names[index] : "????");
523                 need_comma = true;
524         }
525         audit_log_end(ab);
526 out:
527         /* release scontext/tcontext */
528         kfree(tcontext_name);
529         kfree(scontext_name);
530 
531         return;
532 }
533 
534 /*
535  * security_boundary_permission - drops violated permissions
536  * on boundary constraint.
537  */
538 static void type_attribute_bounds_av(struct context *scontext,
539                                      struct context *tcontext,
540                                      u16 tclass,
541                                      struct av_decision *avd)
542 {
543         struct context lo_scontext;
544         struct context lo_tcontext;
545         struct av_decision lo_avd;
546         struct type_datum *source;
547         struct type_datum *target;
548         u32 masked = 0;
549 
550         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
551                                     scontext->type - 1);
552         BUG_ON(!source);
553 
554         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
555                                     tcontext->type - 1);
556         BUG_ON(!target);
557 
558         if (source->bounds) {
559                 memset(&lo_avd, 0, sizeof(lo_avd));
560 
561                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
562                 lo_scontext.type = source->bounds;
563 
564                 context_struct_compute_av(&lo_scontext,
565                                           tcontext,
566                                           tclass,
567                                           &lo_avd);
568                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
569                         return;         /* no masked permission */
570                 masked = ~lo_avd.allowed & avd->allowed;
571         }
572 
573         if (target->bounds) {
574                 memset(&lo_avd, 0, sizeof(lo_avd));
575 
576                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
577                 lo_tcontext.type = target->bounds;
578 
579                 context_struct_compute_av(scontext,
580                                           &lo_tcontext,
581                                           tclass,
582                                           &lo_avd);
583                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
584                         return;         /* no masked permission */
585                 masked = ~lo_avd.allowed & avd->allowed;
586         }
587 
588         if (source->bounds && target->bounds) {
589                 memset(&lo_avd, 0, sizeof(lo_avd));
590                 /*
591                  * lo_scontext and lo_tcontext are already
592                  * set up.
593                  */
594 
595                 context_struct_compute_av(&lo_scontext,
596                                           &lo_tcontext,
597                                           tclass,
598                                           &lo_avd);
599                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
600                         return;         /* no masked permission */
601                 masked = ~lo_avd.allowed & avd->allowed;
602         }
603 
604         if (masked) {
605                 /* mask violated permissions */
606                 avd->allowed &= ~masked;
607 
608                 /* audit masked permissions */
609                 security_dump_masked_av(scontext, tcontext,
610                                         tclass, masked, "bounds");
611         }
612 }
613 
614 /*
615  * Compute access vectors based on a context structure pair for
616  * the permissions in a particular class.
617  */
618 static void context_struct_compute_av(struct context *scontext,
619                                       struct context *tcontext,
620                                       u16 tclass,
621                                       struct av_decision *avd)
622 {
623         struct constraint_node *constraint;
624         struct role_allow *ra;
625         struct avtab_key avkey;
626         struct avtab_node *node;
627         struct class_datum *tclass_datum;
628         struct ebitmap *sattr, *tattr;
629         struct ebitmap_node *snode, *tnode;
630         unsigned int i, j;
631 
632         avd->allowed = 0;
633         avd->auditallow = 0;
634         avd->auditdeny = 0xffffffff;
635 
636         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
637                 if (printk_ratelimit())
638                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
639                 return;
640         }
641 
642         tclass_datum = policydb.class_val_to_struct[tclass - 1];
643 
644         /*
645          * If a specific type enforcement rule was defined for
646          * this permission check, then use it.
647          */
648         avkey.target_class = tclass;
649         avkey.specified = AVTAB_AV;
650         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
651         BUG_ON(!sattr);
652         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
653         BUG_ON(!tattr);
654         ebitmap_for_each_positive_bit(sattr, snode, i) {
655                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
656                         avkey.source_type = i + 1;
657                         avkey.target_type = j + 1;
658                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
659                              node;
660                              node = avtab_search_node_next(node, avkey.specified)) {
661                                 if (node->key.specified == AVTAB_ALLOWED)
662                                         avd->allowed |= node->datum.data;
663                                 else if (node->key.specified == AVTAB_AUDITALLOW)
664                                         avd->auditallow |= node->datum.data;
665                                 else if (node->key.specified == AVTAB_AUDITDENY)
666                                         avd->auditdeny &= node->datum.data;
667                         }
668 
669                         /* Check conditional av table for additional permissions */
670                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
671 
672                 }
673         }
674 
675         /*
676          * Remove any permissions prohibited by a constraint (this includes
677          * the MLS policy).
678          */
679         constraint = tclass_datum->constraints;
680         while (constraint) {
681                 if ((constraint->permissions & (avd->allowed)) &&
682                     !constraint_expr_eval(scontext, tcontext, NULL,
683                                           constraint->expr)) {
684                         avd->allowed &= ~(constraint->permissions);
685                 }
686                 constraint = constraint->next;
687         }
688 
689         /*
690          * If checking process transition permission and the
691          * role is changing, then check the (current_role, new_role)
692          * pair.
693          */
694         if (tclass == policydb.process_class &&
695             (avd->allowed & policydb.process_trans_perms) &&
696             scontext->role != tcontext->role) {
697                 for (ra = policydb.role_allow; ra; ra = ra->next) {
698                         if (scontext->role == ra->role &&
699                             tcontext->role == ra->new_role)
700                                 break;
701                 }
702                 if (!ra)
703                         avd->allowed &= ~policydb.process_trans_perms;
704         }
705 
706         /*
707          * If the given source and target types have boundary
708          * constraint, lazy checks have to mask any violated
709          * permission and notice it to userspace via audit.
710          */
711         type_attribute_bounds_av(scontext, tcontext,
712                                  tclass, avd);
713 }
714 
715 static int security_validtrans_handle_fail(struct context *ocontext,
716                                            struct context *ncontext,
717                                            struct context *tcontext,
718                                            u16 tclass)
719 {
720         char *o = NULL, *n = NULL, *t = NULL;
721         u32 olen, nlen, tlen;
722 
723         if (context_struct_to_string(ocontext, &o, &olen))
724                 goto out;
725         if (context_struct_to_string(ncontext, &n, &nlen))
726                 goto out;
727         if (context_struct_to_string(tcontext, &t, &tlen))
728                 goto out;
729         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
730                   "security_validate_transition:  denied for"
731                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
732                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
733 out:
734         kfree(o);
735         kfree(n);
736         kfree(t);
737 
738         if (!selinux_enforcing)
739                 return 0;
740         return -EPERM;
741 }
742 
743 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
744                                  u16 orig_tclass)
745 {
746         struct context *ocontext;
747         struct context *ncontext;
748         struct context *tcontext;
749         struct class_datum *tclass_datum;
750         struct constraint_node *constraint;
751         u16 tclass;
752         int rc = 0;
753 
754         if (!ss_initialized)
755                 return 0;
756 
757         read_lock(&policy_rwlock);
758 
759         tclass = unmap_class(orig_tclass);
760 
761         if (!tclass || tclass > policydb.p_classes.nprim) {
762                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
763                         __func__, tclass);
764                 rc = -EINVAL;
765                 goto out;
766         }
767         tclass_datum = policydb.class_val_to_struct[tclass - 1];
768 
769         ocontext = sidtab_search(&sidtab, oldsid);
770         if (!ocontext) {
771                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
772                         __func__, oldsid);
773                 rc = -EINVAL;
774                 goto out;
775         }
776 
777         ncontext = sidtab_search(&sidtab, newsid);
778         if (!ncontext) {
779                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
780                         __func__, newsid);
781                 rc = -EINVAL;
782                 goto out;
783         }
784 
785         tcontext = sidtab_search(&sidtab, tasksid);
786         if (!tcontext) {
787                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
788                         __func__, tasksid);
789                 rc = -EINVAL;
790                 goto out;
791         }
792 
793         constraint = tclass_datum->validatetrans;
794         while (constraint) {
795                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
796                                           constraint->expr)) {
797                         rc = security_validtrans_handle_fail(ocontext, ncontext,
798                                                              tcontext, tclass);
799                         goto out;
800                 }
801                 constraint = constraint->next;
802         }
803 
804 out:
805         read_unlock(&policy_rwlock);
806         return rc;
807 }
808 
809 /*
810  * security_bounded_transition - check whether the given
811  * transition is directed to bounded, or not.
812  * It returns 0, if @newsid is bounded by @oldsid.
813  * Otherwise, it returns error code.
814  *
815  * @oldsid : current security identifier
816  * @newsid : destinated security identifier
817  */
818 int security_bounded_transition(u32 old_sid, u32 new_sid)
819 {
820         struct context *old_context, *new_context;
821         struct type_datum *type;
822         int index;
823         int rc;
824 
825         read_lock(&policy_rwlock);
826 
827         rc = -EINVAL;
828         old_context = sidtab_search(&sidtab, old_sid);
829         if (!old_context) {
830                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
831                        __func__, old_sid);
832                 goto out;
833         }
834 
835         rc = -EINVAL;
836         new_context = sidtab_search(&sidtab, new_sid);
837         if (!new_context) {
838                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
839                        __func__, new_sid);
840                 goto out;
841         }
842 
843         rc = 0;
844         /* type/domain unchanged */
845         if (old_context->type == new_context->type)
846                 goto out;
847 
848         index = new_context->type;
849         while (true) {
850                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
851                                           index - 1);
852                 BUG_ON(!type);
853 
854                 /* not bounded anymore */
855                 rc = -EPERM;
856                 if (!type->bounds)
857                         break;
858 
859                 /* @newsid is bounded by @oldsid */
860                 rc = 0;
861                 if (type->bounds == old_context->type)
862                         break;
863 
864                 index = type->bounds;
865         }
866 
867         if (rc) {
868                 char *old_name = NULL;
869                 char *new_name = NULL;
870                 u32 length;
871 
872                 if (!context_struct_to_string(old_context,
873                                               &old_name, &length) &&
874                     !context_struct_to_string(new_context,
875                                               &new_name, &length)) {
876                         audit_log(current->audit_context,
877                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
878                                   "op=security_bounded_transition "
879                                   "result=denied "
880                                   "oldcontext=%s newcontext=%s",
881                                   old_name, new_name);
882                 }
883                 kfree(new_name);
884                 kfree(old_name);
885         }
886 out:
887         read_unlock(&policy_rwlock);
888 
889         return rc;
890 }
891 
892 static void avd_init(struct av_decision *avd)
893 {
894         avd->allowed = 0;
895         avd->auditallow = 0;
896         avd->auditdeny = 0xffffffff;
897         avd->seqno = latest_granting;
898         avd->flags = 0;
899 }
900 
901 
902 /**
903  * security_compute_av - Compute access vector decisions.
904  * @ssid: source security identifier
905  * @tsid: target security identifier
906  * @tclass: target security class
907  * @avd: access vector decisions
908  *
909  * Compute a set of access vector decisions based on the
910  * SID pair (@ssid, @tsid) for the permissions in @tclass.
911  */
912 void security_compute_av(u32 ssid,
913                          u32 tsid,
914                          u16 orig_tclass,
915                          struct av_decision *avd)
916 {
917         u16 tclass;
918         struct context *scontext = NULL, *tcontext = NULL;
919 
920         read_lock(&policy_rwlock);
921         avd_init(avd);
922         if (!ss_initialized)
923                 goto allow;
924 
925         scontext = sidtab_search(&sidtab, ssid);
926         if (!scontext) {
927                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
928                        __func__, ssid);
929                 goto out;
930         }
931 
932         /* permissive domain? */
933         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
934                 avd->flags |= AVD_FLAGS_PERMISSIVE;
935 
936         tcontext = sidtab_search(&sidtab, tsid);
937         if (!tcontext) {
938                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
939                        __func__, tsid);
940                 goto out;
941         }
942 
943         tclass = unmap_class(orig_tclass);
944         if (unlikely(orig_tclass && !tclass)) {
945                 if (policydb.allow_unknown)
946                         goto allow;
947                 goto out;
948         }
949         context_struct_compute_av(scontext, tcontext, tclass, avd);
950         map_decision(orig_tclass, avd, policydb.allow_unknown);
951 out:
952         read_unlock(&policy_rwlock);
953         return;
954 allow:
955         avd->allowed = 0xffffffff;
956         goto out;
957 }
958 
959 void security_compute_av_user(u32 ssid,
960                               u32 tsid,
961                               u16 tclass,
962                               struct av_decision *avd)
963 {
964         struct context *scontext = NULL, *tcontext = NULL;
965 
966         read_lock(&policy_rwlock);
967         avd_init(avd);
968         if (!ss_initialized)
969                 goto allow;
970 
971         scontext = sidtab_search(&sidtab, ssid);
972         if (!scontext) {
973                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
974                        __func__, ssid);
975                 goto out;
976         }
977 
978         /* permissive domain? */
979         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
980                 avd->flags |= AVD_FLAGS_PERMISSIVE;
981 
982         tcontext = sidtab_search(&sidtab, tsid);
983         if (!tcontext) {
984                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
985                        __func__, tsid);
986                 goto out;
987         }
988 
989         if (unlikely(!tclass)) {
990                 if (policydb.allow_unknown)
991                         goto allow;
992                 goto out;
993         }
994 
995         context_struct_compute_av(scontext, tcontext, tclass, avd);
996  out:
997         read_unlock(&policy_rwlock);
998         return;
999 allow:
1000         avd->allowed = 0xffffffff;
1001         goto out;
1002 }
1003 
1004 /*
1005  * Write the security context string representation of
1006  * the context structure `context' into a dynamically
1007  * allocated string of the correct size.  Set `*scontext'
1008  * to point to this string and set `*scontext_len' to
1009  * the length of the string.
1010  */
1011 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1012 {
1013         char *scontextp;
1014 
1015         if (scontext)
1016                 *scontext = NULL;
1017         *scontext_len = 0;
1018 
1019         if (context->len) {
1020                 *scontext_len = context->len;
1021                 if (scontext) {
1022                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1023                         if (!(*scontext))
1024                                 return -ENOMEM;
1025                 }
1026                 return 0;
1027         }
1028 
1029         /* Compute the size of the context. */
1030         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033         *scontext_len += mls_compute_context_len(context);
1034 
1035         if (!scontext)
1036                 return 0;
1037 
1038         /* Allocate space for the context; caller must free this space. */
1039         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040         if (!scontextp)
1041                 return -ENOMEM;
1042         *scontext = scontextp;
1043 
1044         /*
1045          * Copy the user name, role name and type name into the context.
1046          */
1047         sprintf(scontextp, "%s:%s:%s",
1048                 sym_name(&policydb, SYM_USERS, context->user - 1),
1049                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054 
1055         mls_sid_to_context(context, &scontextp);
1056 
1057         *scontextp = 0;
1058 
1059         return 0;
1060 }
1061 
1062 #include "initial_sid_to_string.h"
1063 
1064 const char *security_get_initial_sid_context(u32 sid)
1065 {
1066         if (unlikely(sid > SECINITSID_NUM))
1067                 return NULL;
1068         return initial_sid_to_string[sid];
1069 }
1070 
1071 static int security_sid_to_context_core(u32 sid, char **scontext,
1072                                         u32 *scontext_len, int force)
1073 {
1074         struct context *context;
1075         int rc = 0;
1076 
1077         if (scontext)
1078                 *scontext = NULL;
1079         *scontext_len  = 0;
1080 
1081         if (!ss_initialized) {
1082                 if (sid <= SECINITSID_NUM) {
1083                         char *scontextp;
1084 
1085                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086                         if (!scontext)
1087                                 goto out;
1088                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089                         if (!scontextp) {
1090                                 rc = -ENOMEM;
1091                                 goto out;
1092                         }
1093                         strcpy(scontextp, initial_sid_to_string[sid]);
1094                         *scontext = scontextp;
1095                         goto out;
1096                 }
1097                 printk(KERN_ERR "SELinux: %s:  called before initial "
1098                        "load_policy on unknown SID %d\n", __func__, sid);
1099                 rc = -EINVAL;
1100                 goto out;
1101         }
1102         read_lock(&policy_rwlock);
1103         if (force)
1104                 context = sidtab_search_force(&sidtab, sid);
1105         else
1106                 context = sidtab_search(&sidtab, sid);
1107         if (!context) {
1108                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1109                         __func__, sid);
1110                 rc = -EINVAL;
1111                 goto out_unlock;
1112         }
1113         rc = context_struct_to_string(context, scontext, scontext_len);
1114 out_unlock:
1115         read_unlock(&policy_rwlock);
1116 out:
1117         return rc;
1118 
1119 }
1120 
1121 /**
1122  * security_sid_to_context - Obtain a context for a given SID.
1123  * @sid: security identifier, SID
1124  * @scontext: security context
1125  * @scontext_len: length in bytes
1126  *
1127  * Write the string representation of the context associated with @sid
1128  * into a dynamically allocated string of the correct size.  Set @scontext
1129  * to point to this string and set @scontext_len to the length of the string.
1130  */
1131 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132 {
1133         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134 }
1135 
1136 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137 {
1138         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139 }
1140 
1141 /*
1142  * Caveat:  Mutates scontext.
1143  */
1144 static int string_to_context_struct(struct policydb *pol,
1145                                     struct sidtab *sidtabp,
1146                                     char *scontext,
1147                                     u32 scontext_len,
1148                                     struct context *ctx,
1149                                     u32 def_sid)
1150 {
1151         struct role_datum *role;
1152         struct type_datum *typdatum;
1153         struct user_datum *usrdatum;
1154         char *scontextp, *p, oldc;
1155         int rc = 0;
1156 
1157         context_init(ctx);
1158 
1159         /* Parse the security context. */
1160 
1161         rc = -EINVAL;
1162         scontextp = (char *) scontext;
1163 
1164         /* Extract the user. */
1165         p = scontextp;
1166         while (*p && *p != ':')
1167                 p++;
1168 
1169         if (*p == 0)
1170                 goto out;
1171 
1172         *p++ = 0;
1173 
1174         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175         if (!usrdatum)
1176                 goto out;
1177 
1178         ctx->user = usrdatum->value;
1179 
1180         /* Extract role. */
1181         scontextp = p;
1182         while (*p && *p != ':')
1183                 p++;
1184 
1185         if (*p == 0)
1186                 goto out;
1187 
1188         *p++ = 0;
1189 
1190         role = hashtab_search(pol->p_roles.table, scontextp);
1191         if (!role)
1192                 goto out;
1193         ctx->role = role->value;
1194 
1195         /* Extract type. */
1196         scontextp = p;
1197         while (*p && *p != ':')
1198                 p++;
1199         oldc = *p;
1200         *p++ = 0;
1201 
1202         typdatum = hashtab_search(pol->p_types.table, scontextp);
1203         if (!typdatum || typdatum->attribute)
1204                 goto out;
1205 
1206         ctx->type = typdatum->value;
1207 
1208         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209         if (rc)
1210                 goto out;
1211 
1212         rc = -EINVAL;
1213         if ((p - scontext) < scontext_len)
1214                 goto out;
1215 
1216         /* Check the validity of the new context. */
1217         if (!policydb_context_isvalid(pol, ctx))
1218                 goto out;
1219         rc = 0;
1220 out:
1221         if (rc)
1222                 context_destroy(ctx);
1223         return rc;
1224 }
1225 
1226 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228                                         int force)
1229 {
1230         char *scontext2, *str = NULL;
1231         struct context context;
1232         int rc = 0;
1233 
1234         /* An empty security context is never valid. */
1235         if (!scontext_len)
1236                 return -EINVAL;
1237 
1238         if (!ss_initialized) {
1239                 int i;
1240 
1241                 for (i = 1; i < SECINITSID_NUM; i++) {
1242                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1243                                 *sid = i;
1244                                 return 0;
1245                         }
1246                 }
1247                 *sid = SECINITSID_KERNEL;
1248                 return 0;
1249         }
1250         *sid = SECSID_NULL;
1251 
1252         /* Copy the string so that we can modify the copy as we parse it. */
1253         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1254         if (!scontext2)
1255                 return -ENOMEM;
1256         memcpy(scontext2, scontext, scontext_len);
1257         scontext2[scontext_len] = 0;
1258 
1259         if (force) {
1260                 /* Save another copy for storing in uninterpreted form */
1261                 rc = -ENOMEM;
1262                 str = kstrdup(scontext2, gfp_flags);
1263                 if (!str)
1264                         goto out;
1265         }
1266 
1267         read_lock(&policy_rwlock);
1268         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1269                                       scontext_len, &context, def_sid);
1270         if (rc == -EINVAL && force) {
1271                 context.str = str;
1272                 context.len = scontext_len;
1273                 str = NULL;
1274         } else if (rc)
1275                 goto out_unlock;
1276         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1277         context_destroy(&context);
1278 out_unlock:
1279         read_unlock(&policy_rwlock);
1280 out:
1281         kfree(scontext2);
1282         kfree(str);
1283         return rc;
1284 }
1285 
1286 /**
1287  * security_context_to_sid - Obtain a SID for a given security context.
1288  * @scontext: security context
1289  * @scontext_len: length in bytes
1290  * @sid: security identifier, SID
1291  *
1292  * Obtains a SID associated with the security context that
1293  * has the string representation specified by @scontext.
1294  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1295  * memory is available, or 0 on success.
1296  */
1297 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1298 {
1299         return security_context_to_sid_core(scontext, scontext_len,
1300                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1301 }
1302 
1303 /**
1304  * security_context_to_sid_default - Obtain a SID for a given security context,
1305  * falling back to specified default if needed.
1306  *
1307  * @scontext: security context
1308  * @scontext_len: length in bytes
1309  * @sid: security identifier, SID
1310  * @def_sid: default SID to assign on error
1311  *
1312  * Obtains a SID associated with the security context that
1313  * has the string representation specified by @scontext.
1314  * The default SID is passed to the MLS layer to be used to allow
1315  * kernel labeling of the MLS field if the MLS field is not present
1316  * (for upgrading to MLS without full relabel).
1317  * Implicitly forces adding of the context even if it cannot be mapped yet.
1318  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1319  * memory is available, or 0 on success.
1320  */
1321 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1322                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1323 {
1324         return security_context_to_sid_core(scontext, scontext_len,
1325                                             sid, def_sid, gfp_flags, 1);
1326 }
1327 
1328 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1329                                   u32 *sid)
1330 {
1331         return security_context_to_sid_core(scontext, scontext_len,
1332                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1333 }
1334 
1335 static int compute_sid_handle_invalid_context(
1336         struct context *scontext,
1337         struct context *tcontext,
1338         u16 tclass,
1339         struct context *newcontext)
1340 {
1341         char *s = NULL, *t = NULL, *n = NULL;
1342         u32 slen, tlen, nlen;
1343 
1344         if (context_struct_to_string(scontext, &s, &slen))
1345                 goto out;
1346         if (context_struct_to_string(tcontext, &t, &tlen))
1347                 goto out;
1348         if (context_struct_to_string(newcontext, &n, &nlen))
1349                 goto out;
1350         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1351                   "security_compute_sid:  invalid context %s"
1352                   " for scontext=%s"
1353                   " tcontext=%s"
1354                   " tclass=%s",
1355                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1356 out:
1357         kfree(s);
1358         kfree(t);
1359         kfree(n);
1360         if (!selinux_enforcing)
1361                 return 0;
1362         return -EACCES;
1363 }
1364 
1365 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1366                                   u32 stype, u32 ttype, u16 tclass,
1367                                   const char *objname)
1368 {
1369         struct filename_trans ft;
1370         struct filename_trans_datum *otype;
1371 
1372         /*
1373          * Most filename trans rules are going to live in specific directories
1374          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1375          * if the ttype does not contain any rules.
1376          */
1377         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1378                 return;
1379 
1380         ft.stype = stype;
1381         ft.ttype = ttype;
1382         ft.tclass = tclass;
1383         ft.name = objname;
1384 
1385         otype = hashtab_search(p->filename_trans, &ft);
1386         if (otype)
1387                 newcontext->type = otype->otype;
1388 }
1389 
1390 static int security_compute_sid(u32 ssid,
1391                                 u32 tsid,
1392                                 u16 orig_tclass,
1393                                 u32 specified,
1394                                 const char *objname,
1395                                 u32 *out_sid,
1396                                 bool kern)
1397 {
1398         struct class_datum *cladatum = NULL;
1399         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1400         struct role_trans *roletr = NULL;
1401         struct avtab_key avkey;
1402         struct avtab_datum *avdatum;
1403         struct avtab_node *node;
1404         u16 tclass;
1405         int rc = 0;
1406         bool sock;
1407 
1408         if (!ss_initialized) {
1409                 switch (orig_tclass) {
1410                 case SECCLASS_PROCESS: /* kernel value */
1411                         *out_sid = ssid;
1412                         break;
1413                 default:
1414                         *out_sid = tsid;
1415                         break;
1416                 }
1417                 goto out;
1418         }
1419 
1420         context_init(&newcontext);
1421 
1422         read_lock(&policy_rwlock);
1423 
1424         if (kern) {
1425                 tclass = unmap_class(orig_tclass);
1426                 sock = security_is_socket_class(orig_tclass);
1427         } else {
1428                 tclass = orig_tclass;
1429                 sock = security_is_socket_class(map_class(tclass));
1430         }
1431 
1432         scontext = sidtab_search(&sidtab, ssid);
1433         if (!scontext) {
1434                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1435                        __func__, ssid);
1436                 rc = -EINVAL;
1437                 goto out_unlock;
1438         }
1439         tcontext = sidtab_search(&sidtab, tsid);
1440         if (!tcontext) {
1441                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1442                        __func__, tsid);
1443                 rc = -EINVAL;
1444                 goto out_unlock;
1445         }
1446 
1447         if (tclass && tclass <= policydb.p_classes.nprim)
1448                 cladatum = policydb.class_val_to_struct[tclass - 1];
1449 
1450         /* Set the user identity. */
1451         switch (specified) {
1452         case AVTAB_TRANSITION:
1453         case AVTAB_CHANGE:
1454                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1455                         newcontext.user = tcontext->user;
1456                 } else {
1457                         /* notice this gets both DEFAULT_SOURCE and unset */
1458                         /* Use the process user identity. */
1459                         newcontext.user = scontext->user;
1460                 }
1461                 break;
1462         case AVTAB_MEMBER:
1463                 /* Use the related object owner. */
1464                 newcontext.user = tcontext->user;
1465                 break;
1466         }
1467 
1468         /* Set the role to default values. */
1469         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1470                 newcontext.role = scontext->role;
1471         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1472                 newcontext.role = tcontext->role;
1473         } else {
1474                 if ((tclass == policydb.process_class) || (sock == true))
1475                         newcontext.role = scontext->role;
1476                 else
1477                         newcontext.role = OBJECT_R_VAL;
1478         }
1479 
1480         /* Set the type to default values. */
1481         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1482                 newcontext.type = scontext->type;
1483         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1484                 newcontext.type = tcontext->type;
1485         } else {
1486                 if ((tclass == policydb.process_class) || (sock == true)) {
1487                         /* Use the type of process. */
1488                         newcontext.type = scontext->type;
1489                 } else {
1490                         /* Use the type of the related object. */
1491                         newcontext.type = tcontext->type;
1492                 }
1493         }
1494 
1495         /* Look for a type transition/member/change rule. */
1496         avkey.source_type = scontext->type;
1497         avkey.target_type = tcontext->type;
1498         avkey.target_class = tclass;
1499         avkey.specified = specified;
1500         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1501 
1502         /* If no permanent rule, also check for enabled conditional rules */
1503         if (!avdatum) {
1504                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1505                 for (; node; node = avtab_search_node_next(node, specified)) {
1506                         if (node->key.specified & AVTAB_ENABLED) {
1507                                 avdatum = &node->datum;
1508                                 break;
1509                         }
1510                 }
1511         }
1512 
1513         if (avdatum) {
1514                 /* Use the type from the type transition/member/change rule. */
1515                 newcontext.type = avdatum->data;
1516         }
1517 
1518         /* if we have a objname this is a file trans check so check those rules */
1519         if (objname)
1520                 filename_compute_type(&policydb, &newcontext, scontext->type,
1521                                       tcontext->type, tclass, objname);
1522 
1523         /* Check for class-specific changes. */
1524         if (specified & AVTAB_TRANSITION) {
1525                 /* Look for a role transition rule. */
1526                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1527                         if ((roletr->role == scontext->role) &&
1528                             (roletr->type == tcontext->type) &&
1529                             (roletr->tclass == tclass)) {
1530                                 /* Use the role transition rule. */
1531                                 newcontext.role = roletr->new_role;
1532                                 break;
1533                         }
1534                 }
1535         }
1536 
1537         /* Set the MLS attributes.
1538            This is done last because it may allocate memory. */
1539         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1540                              &newcontext, sock);
1541         if (rc)
1542                 goto out_unlock;
1543 
1544         /* Check the validity of the context. */
1545         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1546                 rc = compute_sid_handle_invalid_context(scontext,
1547                                                         tcontext,
1548                                                         tclass,
1549                                                         &newcontext);
1550                 if (rc)
1551                         goto out_unlock;
1552         }
1553         /* Obtain the sid for the context. */
1554         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1555 out_unlock:
1556         read_unlock(&policy_rwlock);
1557         context_destroy(&newcontext);
1558 out:
1559         return rc;
1560 }
1561 
1562 /**
1563  * security_transition_sid - Compute the SID for a new subject/object.
1564  * @ssid: source security identifier
1565  * @tsid: target security identifier
1566  * @tclass: target security class
1567  * @out_sid: security identifier for new subject/object
1568  *
1569  * Compute a SID to use for labeling a new subject or object in the
1570  * class @tclass based on a SID pair (@ssid, @tsid).
1571  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1572  * if insufficient memory is available, or %0 if the new SID was
1573  * computed successfully.
1574  */
1575 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1576                             const struct qstr *qstr, u32 *out_sid)
1577 {
1578         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1579                                     qstr ? qstr->name : NULL, out_sid, true);
1580 }
1581 
1582 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1583                                  const char *objname, u32 *out_sid)
1584 {
1585         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1586                                     objname, out_sid, false);
1587 }
1588 
1589 /**
1590  * security_member_sid - Compute the SID for member selection.
1591  * @ssid: source security identifier
1592  * @tsid: target security identifier
1593  * @tclass: target security class
1594  * @out_sid: security identifier for selected member
1595  *
1596  * Compute a SID to use when selecting a member of a polyinstantiated
1597  * object of class @tclass based on a SID pair (@ssid, @tsid).
1598  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1599  * if insufficient memory is available, or %0 if the SID was
1600  * computed successfully.
1601  */
1602 int security_member_sid(u32 ssid,
1603                         u32 tsid,
1604                         u16 tclass,
1605                         u32 *out_sid)
1606 {
1607         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1608                                     out_sid, false);
1609 }
1610 
1611 /**
1612  * security_change_sid - Compute the SID for object relabeling.
1613  * @ssid: source security identifier
1614  * @tsid: target security identifier
1615  * @tclass: target security class
1616  * @out_sid: security identifier for selected member
1617  *
1618  * Compute a SID to use for relabeling an object of class @tclass
1619  * based on a SID pair (@ssid, @tsid).
1620  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1621  * if insufficient memory is available, or %0 if the SID was
1622  * computed successfully.
1623  */
1624 int security_change_sid(u32 ssid,
1625                         u32 tsid,
1626                         u16 tclass,
1627                         u32 *out_sid)
1628 {
1629         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1630                                     out_sid, false);
1631 }
1632 
1633 /* Clone the SID into the new SID table. */
1634 static int clone_sid(u32 sid,
1635                      struct context *context,
1636                      void *arg)
1637 {
1638         struct sidtab *s = arg;
1639 
1640         if (sid > SECINITSID_NUM)
1641                 return sidtab_insert(s, sid, context);
1642         else
1643                 return 0;
1644 }
1645 
1646 static inline int convert_context_handle_invalid_context(struct context *context)
1647 {
1648         char *s;
1649         u32 len;
1650 
1651         if (selinux_enforcing)
1652                 return -EINVAL;
1653 
1654         if (!context_struct_to_string(context, &s, &len)) {
1655                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1656                 kfree(s);
1657         }
1658         return 0;
1659 }
1660 
1661 struct convert_context_args {
1662         struct policydb *oldp;
1663         struct policydb *newp;
1664 };
1665 
1666 /*
1667  * Convert the values in the security context
1668  * structure `c' from the values specified
1669  * in the policy `p->oldp' to the values specified
1670  * in the policy `p->newp'.  Verify that the
1671  * context is valid under the new policy.
1672  */
1673 static int convert_context(u32 key,
1674                            struct context *c,
1675                            void *p)
1676 {
1677         struct convert_context_args *args;
1678         struct context oldc;
1679         struct ocontext *oc;
1680         struct mls_range *range;
1681         struct role_datum *role;
1682         struct type_datum *typdatum;
1683         struct user_datum *usrdatum;
1684         char *s;
1685         u32 len;
1686         int rc = 0;
1687 
1688         if (key <= SECINITSID_NUM)
1689                 goto out;
1690 
1691         args = p;
1692 
1693         if (c->str) {
1694                 struct context ctx;
1695 
1696                 rc = -ENOMEM;
1697                 s = kstrdup(c->str, GFP_KERNEL);
1698                 if (!s)
1699                         goto out;
1700 
1701                 rc = string_to_context_struct(args->newp, NULL, s,
1702                                               c->len, &ctx, SECSID_NULL);
1703                 kfree(s);
1704                 if (!rc) {
1705                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1706                                c->str);
1707                         /* Replace string with mapped representation. */
1708                         kfree(c->str);
1709                         memcpy(c, &ctx, sizeof(*c));
1710                         goto out;
1711                 } else if (rc == -EINVAL) {
1712                         /* Retain string representation for later mapping. */
1713                         rc = 0;
1714                         goto out;
1715                 } else {
1716                         /* Other error condition, e.g. ENOMEM. */
1717                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1718                                c->str, -rc);
1719                         goto out;
1720                 }
1721         }
1722 
1723         rc = context_cpy(&oldc, c);
1724         if (rc)
1725                 goto out;
1726 
1727         /* Convert the user. */
1728         rc = -EINVAL;
1729         usrdatum = hashtab_search(args->newp->p_users.table,
1730                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1731         if (!usrdatum)
1732                 goto bad;
1733         c->user = usrdatum->value;
1734 
1735         /* Convert the role. */
1736         rc = -EINVAL;
1737         role = hashtab_search(args->newp->p_roles.table,
1738                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1739         if (!role)
1740                 goto bad;
1741         c->role = role->value;
1742 
1743         /* Convert the type. */
1744         rc = -EINVAL;
1745         typdatum = hashtab_search(args->newp->p_types.table,
1746                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1747         if (!typdatum)
1748                 goto bad;
1749         c->type = typdatum->value;
1750 
1751         /* Convert the MLS fields if dealing with MLS policies */
1752         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1753                 rc = mls_convert_context(args->oldp, args->newp, c);
1754                 if (rc)
1755                         goto bad;
1756         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1757                 /*
1758                  * Switching between MLS and non-MLS policy:
1759                  * free any storage used by the MLS fields in the
1760                  * context for all existing entries in the sidtab.
1761                  */
1762                 mls_context_destroy(c);
1763         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1764                 /*
1765                  * Switching between non-MLS and MLS policy:
1766                  * ensure that the MLS fields of the context for all
1767                  * existing entries in the sidtab are filled in with a
1768                  * suitable default value, likely taken from one of the
1769                  * initial SIDs.
1770                  */
1771                 oc = args->newp->ocontexts[OCON_ISID];
1772                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1773                         oc = oc->next;
1774                 rc = -EINVAL;
1775                 if (!oc) {
1776                         printk(KERN_ERR "SELinux:  unable to look up"
1777                                 " the initial SIDs list\n");
1778                         goto bad;
1779                 }
1780                 range = &oc->context[0].range;
1781                 rc = mls_range_set(c, range);
1782                 if (rc)
1783                         goto bad;
1784         }
1785 
1786         /* Check the validity of the new context. */
1787         if (!policydb_context_isvalid(args->newp, c)) {
1788                 rc = convert_context_handle_invalid_context(&oldc);
1789                 if (rc)
1790                         goto bad;
1791         }
1792 
1793         context_destroy(&oldc);
1794 
1795         rc = 0;
1796 out:
1797         return rc;
1798 bad:
1799         /* Map old representation to string and save it. */
1800         rc = context_struct_to_string(&oldc, &s, &len);
1801         if (rc)
1802                 return rc;
1803         context_destroy(&oldc);
1804         context_destroy(c);
1805         c->str = s;
1806         c->len = len;
1807         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1808                c->str);
1809         rc = 0;
1810         goto out;
1811 }
1812 
1813 static void security_load_policycaps(void)
1814 {
1815         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1816                                                   POLICYDB_CAPABILITY_NETPEER);
1817         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1818                                                   POLICYDB_CAPABILITY_OPENPERM);
1819 }
1820 
1821 static int security_preserve_bools(struct policydb *p);
1822 
1823 /**
1824  * security_load_policy - Load a security policy configuration.
1825  * @data: binary policy data
1826  * @len: length of data in bytes
1827  *
1828  * Load a new set of security policy configuration data,
1829  * validate it and convert the SID table as necessary.
1830  * This function will flush the access vector cache after
1831  * loading the new policy.
1832  */
1833 int security_load_policy(void *data, size_t len)
1834 {
1835         struct policydb oldpolicydb, newpolicydb;
1836         struct sidtab oldsidtab, newsidtab;
1837         struct selinux_mapping *oldmap, *map = NULL;
1838         struct convert_context_args args;
1839         u32 seqno;
1840         u16 map_size;
1841         int rc = 0;
1842         struct policy_file file = { data, len }, *fp = &file;
1843 
1844         if (!ss_initialized) {
1845                 avtab_cache_init();
1846                 rc = policydb_read(&policydb, fp);
1847                 if (rc) {
1848                         avtab_cache_destroy();
1849                         return rc;
1850                 }
1851 
1852                 policydb.len = len;
1853                 rc = selinux_set_mapping(&policydb, secclass_map,
1854                                          &current_mapping,
1855                                          &current_mapping_size);
1856                 if (rc) {
1857                         policydb_destroy(&policydb);
1858                         avtab_cache_destroy();
1859                         return rc;
1860                 }
1861 
1862                 rc = policydb_load_isids(&policydb, &sidtab);
1863                 if (rc) {
1864                         policydb_destroy(&policydb);
1865                         avtab_cache_destroy();
1866                         return rc;
1867                 }
1868 
1869                 security_load_policycaps();
1870                 ss_initialized = 1;
1871                 seqno = ++latest_granting;
1872                 selinux_complete_init();
1873                 avc_ss_reset(seqno);
1874                 selnl_notify_policyload(seqno);
1875                 selinux_status_update_policyload(seqno);
1876                 selinux_netlbl_cache_invalidate();
1877                 selinux_xfrm_notify_policyload();
1878                 return 0;
1879         }
1880 
1881 #if 0
1882         sidtab_hash_eval(&sidtab, "sids");
1883 #endif
1884 
1885         rc = policydb_read(&newpolicydb, fp);
1886         if (rc)
1887                 return rc;
1888 
1889         newpolicydb.len = len;
1890         /* If switching between different policy types, log MLS status */
1891         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1892                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1893         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1894                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1895 
1896         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1897         if (rc) {
1898                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1899                 policydb_destroy(&newpolicydb);
1900                 return rc;
1901         }
1902 
1903         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1904         if (rc)
1905                 goto err;
1906 
1907         rc = security_preserve_bools(&newpolicydb);
1908         if (rc) {
1909                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1910                 goto err;
1911         }
1912 
1913         /* Clone the SID table. */
1914         sidtab_shutdown(&sidtab);
1915 
1916         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1917         if (rc)
1918                 goto err;
1919 
1920         /*
1921          * Convert the internal representations of contexts
1922          * in the new SID table.
1923          */
1924         args.oldp = &policydb;
1925         args.newp = &newpolicydb;
1926         rc = sidtab_map(&newsidtab, convert_context, &args);
1927         if (rc) {
1928                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1929                         " representation of contexts in the new SID"
1930                         " table\n");
1931                 goto err;
1932         }
1933 
1934         /* Save the old policydb and SID table to free later. */
1935         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1936         sidtab_set(&oldsidtab, &sidtab);
1937 
1938         /* Install the new policydb and SID table. */
1939         write_lock_irq(&policy_rwlock);
1940         memcpy(&policydb, &newpolicydb, sizeof policydb);
1941         sidtab_set(&sidtab, &newsidtab);
1942         security_load_policycaps();
1943         oldmap = current_mapping;
1944         current_mapping = map;
1945         current_mapping_size = map_size;
1946         seqno = ++latest_granting;
1947         write_unlock_irq(&policy_rwlock);
1948 
1949         /* Free the old policydb and SID table. */
1950         policydb_destroy(&oldpolicydb);
1951         sidtab_destroy(&oldsidtab);
1952         kfree(oldmap);
1953 
1954         avc_ss_reset(seqno);
1955         selnl_notify_policyload(seqno);
1956         selinux_status_update_policyload(seqno);
1957         selinux_netlbl_cache_invalidate();
1958         selinux_xfrm_notify_policyload();
1959 
1960         return 0;
1961 
1962 err:
1963         kfree(map);
1964         sidtab_destroy(&newsidtab);
1965         policydb_destroy(&newpolicydb);
1966         return rc;
1967 
1968 }
1969 
1970 size_t security_policydb_len(void)
1971 {
1972         size_t len;
1973 
1974         read_lock(&policy_rwlock);
1975         len = policydb.len;
1976         read_unlock(&policy_rwlock);
1977 
1978         return len;
1979 }
1980 
1981 /**
1982  * security_port_sid - Obtain the SID for a port.
1983  * @protocol: protocol number
1984  * @port: port number
1985  * @out_sid: security identifier
1986  */
1987 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1988 {
1989         struct ocontext *c;
1990         int rc = 0;
1991 
1992         read_lock(&policy_rwlock);
1993 
1994         c = policydb.ocontexts[OCON_PORT];
1995         while (c) {
1996                 if (c->u.port.protocol == protocol &&
1997                     c->u.port.low_port <= port &&
1998                     c->u.port.high_port >= port)
1999                         break;
2000                 c = c->next;
2001         }
2002 
2003         if (c) {
2004                 if (!c->sid[0]) {
2005                         rc = sidtab_context_to_sid(&sidtab,
2006                                                    &c->context[0],
2007                                                    &c->sid[0]);
2008                         if (rc)
2009                                 goto out;
2010                 }
2011                 *out_sid = c->sid[0];
2012         } else {
2013                 *out_sid = SECINITSID_PORT;
2014         }
2015 
2016 out:
2017         read_unlock(&policy_rwlock);
2018         return rc;
2019 }
2020 
2021 /**
2022  * security_netif_sid - Obtain the SID for a network interface.
2023  * @name: interface name
2024  * @if_sid: interface SID
2025  */
2026 int security_netif_sid(char *name, u32 *if_sid)
2027 {
2028         int rc = 0;
2029         struct ocontext *c;
2030 
2031         read_lock(&policy_rwlock);
2032 
2033         c = policydb.ocontexts[OCON_NETIF];
2034         while (c) {
2035                 if (strcmp(name, c->u.name) == 0)
2036                         break;
2037                 c = c->next;
2038         }
2039 
2040         if (c) {
2041                 if (!c->sid[0] || !c->sid[1]) {
2042                         rc = sidtab_context_to_sid(&sidtab,
2043                                                   &c->context[0],
2044                                                   &c->sid[0]);
2045                         if (rc)
2046                                 goto out;
2047                         rc = sidtab_context_to_sid(&sidtab,
2048                                                    &c->context[1],
2049                                                    &c->sid[1]);
2050                         if (rc)
2051                                 goto out;
2052                 }
2053                 *if_sid = c->sid[0];
2054         } else
2055                 *if_sid = SECINITSID_NETIF;
2056 
2057 out:
2058         read_unlock(&policy_rwlock);
2059         return rc;
2060 }
2061 
2062 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2063 {
2064         int i, fail = 0;
2065 
2066         for (i = 0; i < 4; i++)
2067                 if (addr[i] != (input[i] & mask[i])) {
2068                         fail = 1;
2069                         break;
2070                 }
2071 
2072         return !fail;
2073 }
2074 
2075 /**
2076  * security_node_sid - Obtain the SID for a node (host).
2077  * @domain: communication domain aka address family
2078  * @addrp: address
2079  * @addrlen: address length in bytes
2080  * @out_sid: security identifier
2081  */
2082 int security_node_sid(u16 domain,
2083                       void *addrp,
2084                       u32 addrlen,
2085                       u32 *out_sid)
2086 {
2087         int rc;
2088         struct ocontext *c;
2089 
2090         read_lock(&policy_rwlock);
2091 
2092         switch (domain) {
2093         case AF_INET: {
2094                 u32 addr;
2095 
2096                 rc = -EINVAL;
2097                 if (addrlen != sizeof(u32))
2098                         goto out;
2099 
2100                 addr = *((u32 *)addrp);
2101 
2102                 c = policydb.ocontexts[OCON_NODE];
2103                 while (c) {
2104                         if (c->u.node.addr == (addr & c->u.node.mask))
2105                                 break;
2106                         c = c->next;
2107                 }
2108                 break;
2109         }
2110 
2111         case AF_INET6:
2112                 rc = -EINVAL;
2113                 if (addrlen != sizeof(u64) * 2)
2114                         goto out;
2115                 c = policydb.ocontexts[OCON_NODE6];
2116                 while (c) {
2117                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2118                                                 c->u.node6.mask))
2119                                 break;
2120                         c = c->next;
2121                 }
2122                 break;
2123 
2124         default:
2125                 rc = 0;
2126                 *out_sid = SECINITSID_NODE;
2127                 goto out;
2128         }
2129 
2130         if (c) {
2131                 if (!c->sid[0]) {
2132                         rc = sidtab_context_to_sid(&sidtab,
2133                                                    &c->context[0],
2134                                                    &c->sid[0]);
2135                         if (rc)
2136                                 goto out;
2137                 }
2138                 *out_sid = c->sid[0];
2139         } else {
2140                 *out_sid = SECINITSID_NODE;
2141         }
2142 
2143         rc = 0;
2144 out:
2145         read_unlock(&policy_rwlock);
2146         return rc;
2147 }
2148 
2149 #define SIDS_NEL 25
2150 
2151 /**
2152  * security_get_user_sids - Obtain reachable SIDs for a user.
2153  * @fromsid: starting SID
2154  * @username: username
2155  * @sids: array of reachable SIDs for user
2156  * @nel: number of elements in @sids
2157  *
2158  * Generate the set of SIDs for legal security contexts
2159  * for a given user that can be reached by @fromsid.
2160  * Set *@sids to point to a dynamically allocated
2161  * array containing the set of SIDs.  Set *@nel to the
2162  * number of elements in the array.
2163  */
2164 
2165 int security_get_user_sids(u32 fromsid,
2166                            char *username,
2167                            u32 **sids,
2168                            u32 *nel)
2169 {
2170         struct context *fromcon, usercon;
2171         u32 *mysids = NULL, *mysids2, sid;
2172         u32 mynel = 0, maxnel = SIDS_NEL;
2173         struct user_datum *user;
2174         struct role_datum *role;
2175         struct ebitmap_node *rnode, *tnode;
2176         int rc = 0, i, j;
2177 
2178         *sids = NULL;
2179         *nel = 0;
2180 
2181         if (!ss_initialized)
2182                 goto out;
2183 
2184         read_lock(&policy_rwlock);
2185 
2186         context_init(&usercon);
2187 
2188         rc = -EINVAL;
2189         fromcon = sidtab_search(&sidtab, fromsid);
2190         if (!fromcon)
2191                 goto out_unlock;
2192 
2193         rc = -EINVAL;
2194         user = hashtab_search(policydb.p_users.table, username);
2195         if (!user)
2196                 goto out_unlock;
2197 
2198         usercon.user = user->value;
2199 
2200         rc = -ENOMEM;
2201         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2202         if (!mysids)
2203                 goto out_unlock;
2204 
2205         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2206                 role = policydb.role_val_to_struct[i];
2207                 usercon.role = i + 1;
2208                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2209                         usercon.type = j + 1;
2210 
2211                         if (mls_setup_user_range(fromcon, user, &usercon))
2212                                 continue;
2213 
2214                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2215                         if (rc)
2216                                 goto out_unlock;
2217                         if (mynel < maxnel) {
2218                                 mysids[mynel++] = sid;
2219                         } else {
2220                                 rc = -ENOMEM;
2221                                 maxnel += SIDS_NEL;
2222                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2223                                 if (!mysids2)
2224                                         goto out_unlock;
2225                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2226                                 kfree(mysids);
2227                                 mysids = mysids2;
2228                                 mysids[mynel++] = sid;
2229                         }
2230                 }
2231         }
2232         rc = 0;
2233 out_unlock:
2234         read_unlock(&policy_rwlock);
2235         if (rc || !mynel) {
2236                 kfree(mysids);
2237                 goto out;
2238         }
2239 
2240         rc = -ENOMEM;
2241         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2242         if (!mysids2) {
2243                 kfree(mysids);
2244                 goto out;
2245         }
2246         for (i = 0, j = 0; i < mynel; i++) {
2247                 struct av_decision dummy_avd;
2248                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2249                                           SECCLASS_PROCESS, /* kernel value */
2250                                           PROCESS__TRANSITION, AVC_STRICT,
2251                                           &dummy_avd);
2252                 if (!rc)
2253                         mysids2[j++] = mysids[i];
2254                 cond_resched();
2255         }
2256         rc = 0;
2257         kfree(mysids);
2258         *sids = mysids2;
2259         *nel = j;
2260 out:
2261         return rc;
2262 }
2263 
2264 /**
2265  * security_genfs_sid - Obtain a SID for a file in a filesystem
2266  * @fstype: filesystem type
2267  * @path: path from root of mount
2268  * @sclass: file security class
2269  * @sid: SID for path
2270  *
2271  * Obtain a SID to use for a file in a filesystem that
2272  * cannot support xattr or use a fixed labeling behavior like
2273  * transition SIDs or task SIDs.
2274  */
2275 int security_genfs_sid(const char *fstype,
2276                        char *path,
2277                        u16 orig_sclass,
2278                        u32 *sid)
2279 {
2280         int len;
2281         u16 sclass;
2282         struct genfs *genfs;
2283         struct ocontext *c;
2284         int rc, cmp = 0;
2285 
2286         while (path[0] == '/' && path[1] == '/')
2287                 path++;
2288 
2289         read_lock(&policy_rwlock);
2290 
2291         sclass = unmap_class(orig_sclass);
2292         *sid = SECINITSID_UNLABELED;
2293 
2294         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2295                 cmp = strcmp(fstype, genfs->fstype);
2296                 if (cmp <= 0)
2297                         break;
2298         }
2299 
2300         rc = -ENOENT;
2301         if (!genfs || cmp)
2302                 goto out;
2303 
2304         for (c = genfs->head; c; c = c->next) {
2305                 len = strlen(c->u.name);
2306                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2307                     (strncmp(c->u.name, path, len) == 0))
2308                         break;
2309         }
2310 
2311         rc = -ENOENT;
2312         if (!c)
2313                 goto out;
2314 
2315         if (!c->sid[0]) {
2316                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2317                 if (rc)
2318                         goto out;
2319         }
2320 
2321         *sid = c->sid[0];
2322         rc = 0;
2323 out:
2324         read_unlock(&policy_rwlock);
2325         return rc;
2326 }
2327 
2328 /**
2329  * security_fs_use - Determine how to handle labeling for a filesystem.
2330  * @fstype: filesystem type
2331  * @behavior: labeling behavior
2332  * @sid: SID for filesystem (superblock)
2333  */
2334 int security_fs_use(
2335         const char *fstype,
2336         unsigned int *behavior,
2337         u32 *sid)
2338 {
2339         int rc = 0;
2340         struct ocontext *c;
2341 
2342         read_lock(&policy_rwlock);
2343 
2344         c = policydb.ocontexts[OCON_FSUSE];
2345         while (c) {
2346                 if (strcmp(fstype, c->u.name) == 0)
2347                         break;
2348                 c = c->next;
2349         }
2350 
2351         if (c) {
2352                 *behavior = c->v.behavior;
2353                 if (!c->sid[0]) {
2354                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2355                                                    &c->sid[0]);
2356                         if (rc)
2357                                 goto out;
2358                 }
2359                 *sid = c->sid[0];
2360         } else {
2361                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2362                 if (rc) {
2363                         *behavior = SECURITY_FS_USE_NONE;
2364                         rc = 0;
2365                 } else {
2366                         *behavior = SECURITY_FS_USE_GENFS;
2367                 }
2368         }
2369 
2370 out:
2371         read_unlock(&policy_rwlock);
2372         return rc;
2373 }
2374 
2375 int security_get_bools(int *len, char ***names, int **values)
2376 {
2377         int i, rc;
2378 
2379         read_lock(&policy_rwlock);
2380         *names = NULL;
2381         *values = NULL;
2382 
2383         rc = 0;
2384         *len = policydb.p_bools.nprim;
2385         if (!*len)
2386                 goto out;
2387 
2388         rc = -ENOMEM;
2389         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2390         if (!*names)
2391                 goto err;
2392 
2393         rc = -ENOMEM;
2394         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2395         if (!*values)
2396                 goto err;
2397 
2398         for (i = 0; i < *len; i++) {
2399                 size_t name_len;
2400 
2401                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2402                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2403 
2404                 rc = -ENOMEM;
2405                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2406                 if (!(*names)[i])
2407                         goto err;
2408 
2409                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2410                 (*names)[i][name_len - 1] = 0;
2411         }
2412         rc = 0;
2413 out:
2414         read_unlock(&policy_rwlock);
2415         return rc;
2416 err:
2417         if (*names) {
2418                 for (i = 0; i < *len; i++)
2419                         kfree((*names)[i]);
2420         }
2421         kfree(*values);
2422         goto out;
2423 }
2424 
2425 
2426 int security_set_bools(int len, int *values)
2427 {
2428         int i, rc;
2429         int lenp, seqno = 0;
2430         struct cond_node *cur;
2431 
2432         write_lock_irq(&policy_rwlock);
2433 
2434         rc = -EFAULT;
2435         lenp = policydb.p_bools.nprim;
2436         if (len != lenp)
2437                 goto out;
2438 
2439         for (i = 0; i < len; i++) {
2440                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2441                         audit_log(current->audit_context, GFP_ATOMIC,
2442                                 AUDIT_MAC_CONFIG_CHANGE,
2443                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2444                                 sym_name(&policydb, SYM_BOOLS, i),
2445                                 !!values[i],
2446                                 policydb.bool_val_to_struct[i]->state,
2447                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2448                                 audit_get_sessionid(current));
2449                 }
2450                 if (values[i])
2451                         policydb.bool_val_to_struct[i]->state = 1;
2452                 else
2453                         policydb.bool_val_to_struct[i]->state = 0;
2454         }
2455 
2456         for (cur = policydb.cond_list; cur; cur = cur->next) {
2457                 rc = evaluate_cond_node(&policydb, cur);
2458                 if (rc)
2459                         goto out;
2460         }
2461 
2462         seqno = ++latest_granting;
2463         rc = 0;
2464 out:
2465         write_unlock_irq(&policy_rwlock);
2466         if (!rc) {
2467                 avc_ss_reset(seqno);
2468                 selnl_notify_policyload(seqno);
2469                 selinux_status_update_policyload(seqno);
2470                 selinux_xfrm_notify_policyload();
2471         }
2472         return rc;
2473 }
2474 
2475 int security_get_bool_value(int bool)
2476 {
2477         int rc;
2478         int len;
2479 
2480         read_lock(&policy_rwlock);
2481 
2482         rc = -EFAULT;
2483         len = policydb.p_bools.nprim;
2484         if (bool >= len)
2485                 goto out;
2486 
2487         rc = policydb.bool_val_to_struct[bool]->state;
2488 out:
2489         read_unlock(&policy_rwlock);
2490         return rc;
2491 }
2492 
2493 static int security_preserve_bools(struct policydb *p)
2494 {
2495         int rc, nbools = 0, *bvalues = NULL, i;
2496         char **bnames = NULL;
2497         struct cond_bool_datum *booldatum;
2498         struct cond_node *cur;
2499 
2500         rc = security_get_bools(&nbools, &bnames, &bvalues);
2501         if (rc)
2502                 goto out;
2503         for (i = 0; i < nbools; i++) {
2504                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2505                 if (booldatum)
2506                         booldatum->state = bvalues[i];
2507         }
2508         for (cur = p->cond_list; cur; cur = cur->next) {
2509                 rc = evaluate_cond_node(p, cur);
2510                 if (rc)
2511                         goto out;
2512         }
2513 
2514 out:
2515         if (bnames) {
2516                 for (i = 0; i < nbools; i++)
2517                         kfree(bnames[i]);
2518         }
2519         kfree(bnames);
2520         kfree(bvalues);
2521         return rc;
2522 }
2523 
2524 /*
2525  * security_sid_mls_copy() - computes a new sid based on the given
2526  * sid and the mls portion of mls_sid.
2527  */
2528 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2529 {
2530         struct context *context1;
2531         struct context *context2;
2532         struct context newcon;
2533         char *s;
2534         u32 len;
2535         int rc;
2536 
2537         rc = 0;
2538         if (!ss_initialized || !policydb.mls_enabled) {
2539                 *new_sid = sid;
2540                 goto out;
2541         }
2542 
2543         context_init(&newcon);
2544 
2545         read_lock(&policy_rwlock);
2546 
2547         rc = -EINVAL;
2548         context1 = sidtab_search(&sidtab, sid);
2549         if (!context1) {
2550                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2551                         __func__, sid);
2552                 goto out_unlock;
2553         }
2554 
2555         rc = -EINVAL;
2556         context2 = sidtab_search(&sidtab, mls_sid);
2557         if (!context2) {
2558                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2559                         __func__, mls_sid);
2560                 goto out_unlock;
2561         }
2562 
2563         newcon.user = context1->user;
2564         newcon.role = context1->role;
2565         newcon.type = context1->type;
2566         rc = mls_context_cpy(&newcon, context2);
2567         if (rc)
2568                 goto out_unlock;
2569 
2570         /* Check the validity of the new context. */
2571         if (!policydb_context_isvalid(&policydb, &newcon)) {
2572                 rc = convert_context_handle_invalid_context(&newcon);
2573                 if (rc) {
2574                         if (!context_struct_to_string(&newcon, &s, &len)) {
2575                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2576                                           "security_sid_mls_copy: invalid context %s", s);
2577                                 kfree(s);
2578                         }
2579                         goto out_unlock;
2580                 }
2581         }
2582 
2583         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2584 out_unlock:
2585         read_unlock(&policy_rwlock);
2586         context_destroy(&newcon);
2587 out:
2588         return rc;
2589 }
2590 
2591 /**
2592  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2593  * @nlbl_sid: NetLabel SID
2594  * @nlbl_type: NetLabel labeling protocol type
2595  * @xfrm_sid: XFRM SID
2596  *
2597  * Description:
2598  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2599  * resolved into a single SID it is returned via @peer_sid and the function
2600  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2601  * returns a negative value.  A table summarizing the behavior is below:
2602  *
2603  *                                 | function return |      @sid
2604  *   ------------------------------+-----------------+-----------------
2605  *   no peer labels                |        0        |    SECSID_NULL
2606  *   single peer label             |        0        |    <peer_label>
2607  *   multiple, consistent labels   |        0        |    <peer_label>
2608  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2609  *
2610  */
2611 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2612                                  u32 xfrm_sid,
2613                                  u32 *peer_sid)
2614 {
2615         int rc;
2616         struct context *nlbl_ctx;
2617         struct context *xfrm_ctx;
2618 
2619         *peer_sid = SECSID_NULL;
2620 
2621         /* handle the common (which also happens to be the set of easy) cases
2622          * right away, these two if statements catch everything involving a
2623          * single or absent peer SID/label */
2624         if (xfrm_sid == SECSID_NULL) {
2625                 *peer_sid = nlbl_sid;
2626                 return 0;
2627         }
2628         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2629          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2630          * is present */
2631         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2632                 *peer_sid = xfrm_sid;
2633                 return 0;
2634         }
2635 
2636         /* we don't need to check ss_initialized here since the only way both
2637          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2638          * security server was initialized and ss_initialized was true */
2639         if (!policydb.mls_enabled)
2640                 return 0;
2641 
2642         read_lock(&policy_rwlock);
2643 
2644         rc = -EINVAL;
2645         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2646         if (!nlbl_ctx) {
2647                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2648                        __func__, nlbl_sid);
2649                 goto out;
2650         }
2651         rc = -EINVAL;
2652         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2653         if (!xfrm_ctx) {
2654                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2655                        __func__, xfrm_sid);
2656                 goto out;
2657         }
2658         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2659         if (rc)
2660                 goto out;
2661 
2662         /* at present NetLabel SIDs/labels really only carry MLS
2663          * information so if the MLS portion of the NetLabel SID
2664          * matches the MLS portion of the labeled XFRM SID/label
2665          * then pass along the XFRM SID as it is the most
2666          * expressive */
2667         *peer_sid = xfrm_sid;
2668 out:
2669         read_unlock(&policy_rwlock);
2670         return rc;
2671 }
2672 
2673 static int get_classes_callback(void *k, void *d, void *args)
2674 {
2675         struct class_datum *datum = d;
2676         char *name = k, **classes = args;
2677         int value = datum->value - 1;
2678 
2679         classes[value] = kstrdup(name, GFP_ATOMIC);
2680         if (!classes[value])
2681                 return -ENOMEM;
2682 
2683         return 0;
2684 }
2685 
2686 int security_get_classes(char ***classes, int *nclasses)
2687 {
2688         int rc;
2689 
2690         read_lock(&policy_rwlock);
2691 
2692         rc = -ENOMEM;
2693         *nclasses = policydb.p_classes.nprim;
2694         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2695         if (!*classes)
2696                 goto out;
2697 
2698         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2699                         *classes);
2700         if (rc) {
2701                 int i;
2702                 for (i = 0; i < *nclasses; i++)
2703                         kfree((*classes)[i]);
2704                 kfree(*classes);
2705         }
2706 
2707 out:
2708         read_unlock(&policy_rwlock);
2709         return rc;
2710 }
2711 
2712 static int get_permissions_callback(void *k, void *d, void *args)
2713 {
2714         struct perm_datum *datum = d;
2715         char *name = k, **perms = args;
2716         int value = datum->value - 1;
2717 
2718         perms[value] = kstrdup(name, GFP_ATOMIC);
2719         if (!perms[value])
2720                 return -ENOMEM;
2721 
2722         return 0;
2723 }
2724 
2725 int security_get_permissions(char *class, char ***perms, int *nperms)
2726 {
2727         int rc, i;
2728         struct class_datum *match;
2729 
2730         read_lock(&policy_rwlock);
2731 
2732         rc = -EINVAL;
2733         match = hashtab_search(policydb.p_classes.table, class);
2734         if (!match) {
2735                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2736                         __func__, class);
2737                 goto out;
2738         }
2739 
2740         rc = -ENOMEM;
2741         *nperms = match->permissions.nprim;
2742         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2743         if (!*perms)
2744                 goto out;
2745 
2746         if (match->comdatum) {
2747                 rc = hashtab_map(match->comdatum->permissions.table,
2748                                 get_permissions_callback, *perms);
2749                 if (rc)
2750                         goto err;
2751         }
2752 
2753         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2754                         *perms);
2755         if (rc)
2756                 goto err;
2757 
2758 out:
2759         read_unlock(&policy_rwlock);
2760         return rc;
2761 
2762 err:
2763         read_unlock(&policy_rwlock);
2764         for (i = 0; i < *nperms; i++)
2765                 kfree((*perms)[i]);
2766         kfree(*perms);
2767         return rc;
2768 }
2769 
2770 int security_get_reject_unknown(void)
2771 {
2772         return policydb.reject_unknown;
2773 }
2774 
2775 int security_get_allow_unknown(void)
2776 {
2777         return policydb.allow_unknown;
2778 }
2779 
2780 /**
2781  * security_policycap_supported - Check for a specific policy capability
2782  * @req_cap: capability
2783  *
2784  * Description:
2785  * This function queries the currently loaded policy to see if it supports the
2786  * capability specified by @req_cap.  Returns true (1) if the capability is
2787  * supported, false (0) if it isn't supported.
2788  *
2789  */
2790 int security_policycap_supported(unsigned int req_cap)
2791 {
2792         int rc;
2793 
2794         read_lock(&policy_rwlock);
2795         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2796         read_unlock(&policy_rwlock);
2797 
2798         return rc;
2799 }
2800 
2801 struct selinux_audit_rule {
2802         u32 au_seqno;
2803         struct context au_ctxt;
2804 };
2805 
2806 void selinux_audit_rule_free(void *vrule)
2807 {
2808         struct selinux_audit_rule *rule = vrule;
2809 
2810         if (rule) {
2811                 context_destroy(&rule->au_ctxt);
2812                 kfree(rule);
2813         }
2814 }
2815 
2816 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2817 {
2818         struct selinux_audit_rule *tmprule;
2819         struct role_datum *roledatum;
2820         struct type_datum *typedatum;
2821         struct user_datum *userdatum;
2822         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2823         int rc = 0;
2824 
2825         *rule = NULL;
2826 
2827         if (!ss_initialized)
2828                 return -EOPNOTSUPP;
2829 
2830         switch (field) {
2831         case AUDIT_SUBJ_USER:
2832         case AUDIT_SUBJ_ROLE:
2833         case AUDIT_SUBJ_TYPE:
2834         case AUDIT_OBJ_USER:
2835         case AUDIT_OBJ_ROLE:
2836         case AUDIT_OBJ_TYPE:
2837                 /* only 'equals' and 'not equals' fit user, role, and type */
2838                 if (op != Audit_equal && op != Audit_not_equal)
2839                         return -EINVAL;
2840                 break;
2841         case AUDIT_SUBJ_SEN:
2842         case AUDIT_SUBJ_CLR:
2843         case AUDIT_OBJ_LEV_LOW:
2844         case AUDIT_OBJ_LEV_HIGH:
2845                 /* we do not allow a range, indicated by the presence of '-' */
2846                 if (strchr(rulestr, '-'))
2847                         return -EINVAL;
2848                 break;
2849         default:
2850                 /* only the above fields are valid */
2851                 return -EINVAL;
2852         }
2853 
2854         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2855         if (!tmprule)
2856                 return -ENOMEM;
2857 
2858         context_init(&tmprule->au_ctxt);
2859 
2860         read_lock(&policy_rwlock);
2861 
2862         tmprule->au_seqno = latest_granting;
2863 
2864         switch (field) {
2865         case AUDIT_SUBJ_USER:
2866         case AUDIT_OBJ_USER:
2867                 rc = -EINVAL;
2868                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2869                 if (!userdatum)
2870                         goto out;
2871                 tmprule->au_ctxt.user = userdatum->value;
2872                 break;
2873         case AUDIT_SUBJ_ROLE:
2874         case AUDIT_OBJ_ROLE:
2875                 rc = -EINVAL;
2876                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2877                 if (!roledatum)
2878                         goto out;
2879                 tmprule->au_ctxt.role = roledatum->value;
2880                 break;
2881         case AUDIT_SUBJ_TYPE:
2882         case AUDIT_OBJ_TYPE:
2883                 rc = -EINVAL;
2884                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2885                 if (!typedatum)
2886                         goto out;
2887                 tmprule->au_ctxt.type = typedatum->value;
2888                 break;
2889         case AUDIT_SUBJ_SEN:
2890         case AUDIT_SUBJ_CLR:
2891         case AUDIT_OBJ_LEV_LOW:
2892         case AUDIT_OBJ_LEV_HIGH:
2893                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2894                 if (rc)
2895                         goto out;
2896                 break;
2897         }
2898         rc = 0;
2899 out:
2900         read_unlock(&policy_rwlock);
2901 
2902         if (rc) {
2903                 selinux_audit_rule_free(tmprule);
2904                 tmprule = NULL;
2905         }
2906 
2907         *rule = tmprule;
2908 
2909         return rc;
2910 }
2911 
2912 /* Check to see if the rule contains any selinux fields */
2913 int selinux_audit_rule_known(struct audit_krule *rule)
2914 {
2915         int i;
2916 
2917         for (i = 0; i < rule->field_count; i++) {
2918                 struct audit_field *f = &rule->fields[i];
2919                 switch (f->type) {
2920                 case AUDIT_SUBJ_USER:
2921                 case AUDIT_SUBJ_ROLE:
2922                 case AUDIT_SUBJ_TYPE:
2923                 case AUDIT_SUBJ_SEN:
2924                 case AUDIT_SUBJ_CLR:
2925                 case AUDIT_OBJ_USER:
2926                 case AUDIT_OBJ_ROLE:
2927                 case AUDIT_OBJ_TYPE:
2928                 case AUDIT_OBJ_LEV_LOW:
2929                 case AUDIT_OBJ_LEV_HIGH:
2930                         return 1;
2931                 }
2932         }
2933 
2934         return 0;
2935 }
2936 
2937 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2938                              struct audit_context *actx)
2939 {
2940         struct context *ctxt;
2941         struct mls_level *level;
2942         struct selinux_audit_rule *rule = vrule;
2943         int match = 0;
2944 
2945         if (!rule) {
2946                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2947                           "selinux_audit_rule_match: missing rule\n");
2948                 return -ENOENT;
2949         }
2950 
2951         read_lock(&policy_rwlock);
2952 
2953         if (rule->au_seqno < latest_granting) {
2954                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2955                           "selinux_audit_rule_match: stale rule\n");
2956                 match = -ESTALE;
2957                 goto out;
2958         }
2959 
2960         ctxt = sidtab_search(&sidtab, sid);
2961         if (!ctxt) {
2962                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2963                           "selinux_audit_rule_match: unrecognized SID %d\n",
2964                           sid);
2965                 match = -ENOENT;
2966                 goto out;
2967         }
2968 
2969         /* a field/op pair that is not caught here will simply fall through
2970            without a match */
2971         switch (field) {
2972         case AUDIT_SUBJ_USER:
2973         case AUDIT_OBJ_USER:
2974                 switch (op) {
2975                 case Audit_equal:
2976                         match = (ctxt->user == rule->au_ctxt.user);
2977                         break;
2978                 case Audit_not_equal:
2979                         match = (ctxt->user != rule->au_ctxt.user);
2980                         break;
2981                 }
2982                 break;
2983         case AUDIT_SUBJ_ROLE:
2984         case AUDIT_OBJ_ROLE:
2985                 switch (op) {
2986                 case Audit_equal:
2987                         match = (ctxt->role == rule->au_ctxt.role);
2988                         break;
2989                 case Audit_not_equal:
2990                         match = (ctxt->role != rule->au_ctxt.role);
2991                         break;
2992                 }
2993                 break;
2994         case AUDIT_SUBJ_TYPE:
2995         case AUDIT_OBJ_TYPE:
2996                 switch (op) {
2997                 case Audit_equal:
2998                         match = (ctxt->type == rule->au_ctxt.type);
2999                         break;
3000                 case Audit_not_equal:
3001                         match = (ctxt->type != rule->au_ctxt.type);
3002                         break;
3003                 }
3004                 break;
3005         case AUDIT_SUBJ_SEN:
3006         case AUDIT_SUBJ_CLR:
3007         case AUDIT_OBJ_LEV_LOW:
3008         case AUDIT_OBJ_LEV_HIGH:
3009                 level = ((field == AUDIT_SUBJ_SEN ||
3010                           field == AUDIT_OBJ_LEV_LOW) ?
3011                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3012                 switch (op) {
3013                 case Audit_equal:
3014                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3015                                              level);
3016                         break;
3017                 case Audit_not_equal:
3018                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3019                                               level);
3020                         break;
3021                 case Audit_lt:
3022                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3023                                                level) &&
3024                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3025                                                level));
3026                         break;
3027                 case Audit_le:
3028                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3029                                               level);
3030                         break;
3031                 case Audit_gt:
3032                         match = (mls_level_dom(level,
3033                                               &rule->au_ctxt.range.level[0]) &&
3034                                  !mls_level_eq(level,
3035                                                &rule->au_ctxt.range.level[0]));
3036                         break;
3037                 case Audit_ge:
3038                         match = mls_level_dom(level,
3039                                               &rule->au_ctxt.range.level[0]);
3040                         break;
3041                 }
3042         }
3043 
3044 out:
3045         read_unlock(&policy_rwlock);
3046         return match;
3047 }
3048 
3049 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3050 
3051 static int aurule_avc_callback(u32 event)
3052 {
3053         int err = 0;
3054 
3055         if (event == AVC_CALLBACK_RESET && aurule_callback)
3056                 err = aurule_callback();
3057         return err;
3058 }
3059 
3060 static int __init aurule_init(void)
3061 {
3062         int err;
3063 
3064         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3065         if (err)
3066                 panic("avc_add_callback() failed, error %d\n", err);
3067 
3068         return err;
3069 }
3070 __initcall(aurule_init);
3071 
3072 #ifdef CONFIG_NETLABEL
3073 /**
3074  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3075  * @secattr: the NetLabel packet security attributes
3076  * @sid: the SELinux SID
3077  *
3078  * Description:
3079  * Attempt to cache the context in @ctx, which was derived from the packet in
3080  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3081  * already been initialized.
3082  *
3083  */
3084 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3085                                       u32 sid)
3086 {
3087         u32 *sid_cache;
3088 
3089         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3090         if (sid_cache == NULL)
3091                 return;
3092         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3093         if (secattr->cache == NULL) {
3094                 kfree(sid_cache);
3095                 return;
3096         }
3097 
3098         *sid_cache = sid;
3099         secattr->cache->free = kfree;
3100         secattr->cache->data = sid_cache;
3101         secattr->flags |= NETLBL_SECATTR_CACHE;
3102 }
3103 
3104 /**
3105  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3106  * @secattr: the NetLabel packet security attributes
3107  * @sid: the SELinux SID
3108  *
3109  * Description:
3110  * Convert the given NetLabel security attributes in @secattr into a
3111  * SELinux SID.  If the @secattr field does not contain a full SELinux
3112  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3113  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3114  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3115  * conversion for future lookups.  Returns zero on success, negative values on
3116  * failure.
3117  *
3118  */
3119 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3120                                    u32 *sid)
3121 {
3122         int rc;
3123         struct context *ctx;
3124         struct context ctx_new;
3125 
3126         if (!ss_initialized) {
3127                 *sid = SECSID_NULL;
3128                 return 0;
3129         }
3130 
3131         read_lock(&policy_rwlock);
3132 
3133         if (secattr->flags & NETLBL_SECATTR_CACHE)
3134                 *sid = *(u32 *)secattr->cache->data;
3135         else if (secattr->flags & NETLBL_SECATTR_SECID)
3136                 *sid = secattr->attr.secid;
3137         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3138                 rc = -EIDRM;
3139                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3140                 if (ctx == NULL)
3141                         goto out;
3142 
3143                 context_init(&ctx_new);
3144                 ctx_new.user = ctx->user;
3145                 ctx_new.role = ctx->role;
3146                 ctx_new.type = ctx->type;
3147                 mls_import_netlbl_lvl(&ctx_new, secattr);
3148                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3149                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3150                                                    secattr->attr.mls.cat);
3151                         if (rc)
3152                                 goto out;
3153                         memcpy(&ctx_new.range.level[1].cat,
3154                                &ctx_new.range.level[0].cat,
3155                                sizeof(ctx_new.range.level[0].cat));
3156                 }
3157                 rc = -EIDRM;
3158                 if (!mls_context_isvalid(&policydb, &ctx_new))
3159                         goto out_free;
3160 
3161                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3162                 if (rc)
3163                         goto out_free;
3164 
3165                 security_netlbl_cache_add(secattr, *sid);
3166 
3167                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3168         } else
3169                 *sid = SECSID_NULL;
3170 
3171         read_unlock(&policy_rwlock);
3172         return 0;
3173 out_free:
3174         ebitmap_destroy(&ctx_new.range.level[0].cat);
3175 out:
3176         read_unlock(&policy_rwlock);
3177         return rc;
3178 }
3179 
3180 /**
3181  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3182  * @sid: the SELinux SID
3183  * @secattr: the NetLabel packet security attributes
3184  *
3185  * Description:
3186  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3187  * Returns zero on success, negative values on failure.
3188  *
3189  */
3190 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3191 {
3192         int rc;
3193         struct context *ctx;
3194 
3195         if (!ss_initialized)
3196                 return 0;
3197 
3198         read_lock(&policy_rwlock);
3199 
3200         rc = -ENOENT;
3201         ctx = sidtab_search(&sidtab, sid);
3202         if (ctx == NULL)
3203                 goto out;
3204 
3205         rc = -ENOMEM;
3206         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3207                                   GFP_ATOMIC);
3208         if (secattr->domain == NULL)
3209                 goto out;
3210 
3211         secattr->attr.secid = sid;
3212         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3213         mls_export_netlbl_lvl(ctx, secattr);
3214         rc = mls_export_netlbl_cat(ctx, secattr);
3215 out:
3216         read_unlock(&policy_rwlock);
3217         return rc;
3218 }
3219 #endif /* CONFIG_NETLABEL */
3220 
3221 /**
3222  * security_read_policy - read the policy.
3223  * @data: binary policy data
3224  * @len: length of data in bytes
3225  *
3226  */
3227 int security_read_policy(void **data, size_t *len)
3228 {
3229         int rc;
3230         struct policy_file fp;
3231 
3232         if (!ss_initialized)
3233                 return -EINVAL;
3234 
3235         *len = security_policydb_len();
3236 
3237         *data = vmalloc_user(*len);
3238         if (!*data)
3239                 return -ENOMEM;
3240 
3241         fp.data = *data;
3242         fp.len = *len;
3243 
3244         read_lock(&policy_rwlock);
3245         rc = policydb_write(&policydb, &fp);
3246         read_unlock(&policy_rwlock);
3247 
3248         if (rc)
3249                 return rc;
3250 
3251         *len = (unsigned long)fp.data - (unsigned long)*data;
3252         return 0;
3253 
3254 }
3255 

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