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