39d732145abe3ac4039f7e41f8e4c8b44a2c5ca3
[linux-2.6.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.moore@hp.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 extern void selnl_notify_policyload(u32 seqno);
74
75 int selinux_policycap_netpeer;
76 int selinux_policycap_openperm;
77
78 static DEFINE_RWLOCK(policy_rwlock);
79
80 static struct sidtab sidtab;
81 struct policydb policydb;
82 int ss_initialized;
83
84 /*
85  * The largest sequence number that has been used when
86  * providing an access decision to the access vector cache.
87  * The sequence number only changes when a policy change
88  * occurs.
89  */
90 static u32 latest_granting;
91
92 /* Forward declaration. */
93 static int context_struct_to_string(struct context *context, char **scontext,
94                                     u32 *scontext_len);
95
96 static void context_struct_compute_av(struct context *scontext,
97                                       struct context *tcontext,
98                                       u16 tclass,
99                                       struct av_decision *avd);
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 pol_value;
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                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
571                         return;         /* no masked permission */
572                 masked = ~lo_avd.allowed & avd->allowed;
573         }
574
575         if (target->bounds) {
576                 memset(&lo_avd, 0, sizeof(lo_avd));
577
578                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
579                 lo_tcontext.type = target->bounds;
580
581                 context_struct_compute_av(scontext,
582                                           &lo_tcontext,
583                                           tclass,
584                                           &lo_avd);
585                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
586                         return;         /* no masked permission */
587                 masked = ~lo_avd.allowed & avd->allowed;
588         }
589
590         if (source->bounds && target->bounds) {
591                 memset(&lo_avd, 0, sizeof(lo_avd));
592                 /*
593                  * lo_scontext and lo_tcontext are already
594                  * set up.
595                  */
596
597                 context_struct_compute_av(&lo_scontext,
598                                           &lo_tcontext,
599                                           tclass,
600                                           &lo_avd);
601                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
602                         return;         /* no masked permission */
603                 masked = ~lo_avd.allowed & avd->allowed;
604         }
605
606         if (masked) {
607                 /* mask violated permissions */
608                 avd->allowed &= ~masked;
609
610                 /* audit masked permissions */
611                 security_dump_masked_av(scontext, tcontext,
612                                         tclass, masked, "bounds");
613         }
614 }
615
616 /*
617  * Compute access vectors based on a context structure pair for
618  * the permissions in a particular class.
619  */
620 static void context_struct_compute_av(struct context *scontext,
621                                       struct context *tcontext,
622                                       u16 tclass,
623                                       struct av_decision *avd)
624 {
625         struct constraint_node *constraint;
626         struct role_allow *ra;
627         struct avtab_key avkey;
628         struct avtab_node *node;
629         struct class_datum *tclass_datum;
630         struct ebitmap *sattr, *tattr;
631         struct ebitmap_node *snode, *tnode;
632         unsigned int i, j;
633
634         avd->allowed = 0;
635         avd->auditallow = 0;
636         avd->auditdeny = 0xffffffff;
637
638         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
639                 if (printk_ratelimit())
640                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
641                 return;
642         }
643
644         tclass_datum = policydb.class_val_to_struct[tclass - 1];
645
646         /*
647          * If a specific type enforcement rule was defined for
648          * this permission check, then use it.
649          */
650         avkey.target_class = tclass;
651         avkey.specified = AVTAB_AV;
652         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
653         BUG_ON(!sattr);
654         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
655         BUG_ON(!tattr);
656         ebitmap_for_each_positive_bit(sattr, snode, i) {
657                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
658                         avkey.source_type = i + 1;
659                         avkey.target_type = j + 1;
660                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
661                              node;
662                              node = avtab_search_node_next(node, avkey.specified)) {
663                                 if (node->key.specified == AVTAB_ALLOWED)
664                                         avd->allowed |= node->datum.data;
665                                 else if (node->key.specified == AVTAB_AUDITALLOW)
666                                         avd->auditallow |= node->datum.data;
667                                 else if (node->key.specified == AVTAB_AUDITDENY)
668                                         avd->auditdeny &= node->datum.data;
669                         }
670
671                         /* Check conditional av table for additional permissions */
672                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
673
674                 }
675         }
676
677         /*
678          * Remove any permissions prohibited by a constraint (this includes
679          * the MLS policy).
680          */
681         constraint = tclass_datum->constraints;
682         while (constraint) {
683                 if ((constraint->permissions & (avd->allowed)) &&
684                     !constraint_expr_eval(scontext, tcontext, NULL,
685                                           constraint->expr)) {
686                         avd->allowed &= ~(constraint->permissions);
687                 }
688                 constraint = constraint->next;
689         }
690
691         /*
692          * If checking process transition permission and the
693          * role is changing, then check the (current_role, new_role)
694          * pair.
695          */
696         if (tclass == policydb.process_class &&
697             (avd->allowed & policydb.process_trans_perms) &&
698             scontext->role != tcontext->role) {
699                 for (ra = policydb.role_allow; ra; ra = ra->next) {
700                         if (scontext->role == ra->role &&
701                             tcontext->role == ra->new_role)
702                                 break;
703                 }
704                 if (!ra)
705                         avd->allowed &= ~policydb.process_trans_perms;
706         }
707
708         /*
709          * If the given source and target types have boundary
710          * constraint, lazy checks have to mask any violated
711          * permission and notice it to userspace via audit.
712          */
713         type_attribute_bounds_av(scontext, tcontext,
714                                  tclass, avd);
715 }
716
717 static int security_validtrans_handle_fail(struct context *ocontext,
718                                            struct context *ncontext,
719                                            struct context *tcontext,
720                                            u16 tclass)
721 {
722         char *o = NULL, *n = NULL, *t = NULL;
723         u32 olen, nlen, tlen;
724
725         if (context_struct_to_string(ocontext, &o, &olen))
726                 goto out;
727         if (context_struct_to_string(ncontext, &n, &nlen))
728                 goto out;
729         if (context_struct_to_string(tcontext, &t, &tlen))
730                 goto out;
731         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
732                   "security_validate_transition:  denied for"
733                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
734                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
735 out:
736         kfree(o);
737         kfree(n);
738         kfree(t);
739
740         if (!selinux_enforcing)
741                 return 0;
742         return -EPERM;
743 }
744
745 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
746                                  u16 orig_tclass)
747 {
748         struct context *ocontext;
749         struct context *ncontext;
750         struct context *tcontext;
751         struct class_datum *tclass_datum;
752         struct constraint_node *constraint;
753         u16 tclass;
754         int rc = 0;
755
756         if (!ss_initialized)
757                 return 0;
758
759         read_lock(&policy_rwlock);
760
761         tclass = unmap_class(orig_tclass);
762
763         if (!tclass || tclass > policydb.p_classes.nprim) {
764                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
765                         __func__, tclass);
766                 rc = -EINVAL;
767                 goto out;
768         }
769         tclass_datum = policydb.class_val_to_struct[tclass - 1];
770
771         ocontext = sidtab_search(&sidtab, oldsid);
772         if (!ocontext) {
773                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
774                         __func__, oldsid);
775                 rc = -EINVAL;
776                 goto out;
777         }
778
779         ncontext = sidtab_search(&sidtab, newsid);
780         if (!ncontext) {
781                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
782                         __func__, newsid);
783                 rc = -EINVAL;
784                 goto out;
785         }
786
787         tcontext = sidtab_search(&sidtab, tasksid);
788         if (!tcontext) {
789                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
790                         __func__, tasksid);
791                 rc = -EINVAL;
792                 goto out;
793         }
794
795         constraint = tclass_datum->validatetrans;
796         while (constraint) {
797                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
798                                           constraint->expr)) {
799                         rc = security_validtrans_handle_fail(ocontext, ncontext,
800                                                              tcontext, tclass);
801                         goto out;
802                 }
803                 constraint = constraint->next;
804         }
805
806 out:
807         read_unlock(&policy_rwlock);
808         return rc;
809 }
810
811 /*
812  * security_bounded_transition - check whether the given
813  * transition is directed to bounded, or not.
814  * It returns 0, if @newsid is bounded by @oldsid.
815  * Otherwise, it returns error code.
816  *
817  * @oldsid : current security identifier
818  * @newsid : destinated security identifier
819  */
820 int security_bounded_transition(u32 old_sid, u32 new_sid)
821 {
822         struct context *old_context, *new_context;
823         struct type_datum *type;
824         int index;
825         int rc;
826
827         read_lock(&policy_rwlock);
828
829         rc = -EINVAL;
830         old_context = sidtab_search(&sidtab, old_sid);
831         if (!old_context) {
832                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
833                        __func__, old_sid);
834                 goto out;
835         }
836
837         rc = -EINVAL;
838         new_context = sidtab_search(&sidtab, new_sid);
839         if (!new_context) {
840                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
841                        __func__, new_sid);
842                 goto out;
843         }
844
845         rc = 0;
846         /* type/domain unchanged */
847         if (old_context->type == new_context->type)
848                 goto out;
849
850         index = new_context->type;
851         while (true) {
852                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
853                                           index - 1);
854                 BUG_ON(!type);
855
856                 /* not bounded anymore */
857                 rc = -EPERM;
858                 if (!type->bounds)
859                         break;
860
861                 /* @newsid is bounded by @oldsid */
862                 rc = 0;
863                 if (type->bounds == old_context->type)
864                         break;
865
866                 index = type->bounds;
867         }
868
869         if (rc) {
870                 char *old_name = NULL;
871                 char *new_name = NULL;
872                 u32 length;
873
874                 if (!context_struct_to_string(old_context,
875                                               &old_name, &length) &&
876                     !context_struct_to_string(new_context,
877                                               &new_name, &length)) {
878                         audit_log(current->audit_context,
879                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
880                                   "op=security_bounded_transition "
881                                   "result=denied "
882                                   "oldcontext=%s newcontext=%s",
883                                   old_name, new_name);
884                 }
885                 kfree(new_name);
886                 kfree(old_name);
887         }
888 out:
889         read_unlock(&policy_rwlock);
890
891         return rc;
892 }
893
894 static void avd_init(struct av_decision *avd)
895 {
896         avd->allowed = 0;
897         avd->auditallow = 0;
898         avd->auditdeny = 0xffffffff;
899         avd->seqno = latest_granting;
900         avd->flags = 0;
901 }
902
903
904 /**
905  * security_compute_av - Compute access vector decisions.
906  * @ssid: source security identifier
907  * @tsid: target security identifier
908  * @tclass: target security class
909  * @avd: access vector decisions
910  *
911  * Compute a set of access vector decisions based on the
912  * SID pair (@ssid, @tsid) for the permissions in @tclass.
913  */
914 void security_compute_av(u32 ssid,
915                          u32 tsid,
916                          u16 orig_tclass,
917                          struct av_decision *avd)
918 {
919         u16 tclass;
920         struct context *scontext = NULL, *tcontext = NULL;
921
922         read_lock(&policy_rwlock);
923         avd_init(avd);
924         if (!ss_initialized)
925                 goto allow;
926
927         scontext = sidtab_search(&sidtab, ssid);
928         if (!scontext) {
929                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
930                        __func__, ssid);
931                 goto out;
932         }
933
934         /* permissive domain? */
935         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
936                 avd->flags |= AVD_FLAGS_PERMISSIVE;
937
938         tcontext = sidtab_search(&sidtab, tsid);
939         if (!tcontext) {
940                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
941                        __func__, tsid);
942                 goto out;
943         }
944
945         tclass = unmap_class(orig_tclass);
946         if (unlikely(orig_tclass && !tclass)) {
947                 if (policydb.allow_unknown)
948                         goto allow;
949                 goto out;
950         }
951         context_struct_compute_av(scontext, tcontext, tclass, avd);
952         map_decision(orig_tclass, avd, policydb.allow_unknown);
953 out:
954         read_unlock(&policy_rwlock);
955         return;
956 allow:
957         avd->allowed = 0xffffffff;
958         goto out;
959 }
960
961 void security_compute_av_user(u32 ssid,
962                               u32 tsid,
963                               u16 tclass,
964                               struct av_decision *avd)
965 {
966         struct context *scontext = NULL, *tcontext = NULL;
967
968         read_lock(&policy_rwlock);
969         avd_init(avd);
970         if (!ss_initialized)
971                 goto allow;
972
973         scontext = sidtab_search(&sidtab, ssid);
974         if (!scontext) {
975                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
976                        __func__, ssid);
977                 goto out;
978         }
979
980         /* permissive domain? */
981         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
982                 avd->flags |= AVD_FLAGS_PERMISSIVE;
983
984         tcontext = sidtab_search(&sidtab, tsid);
985         if (!tcontext) {
986                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
987                        __func__, tsid);
988                 goto out;
989         }
990
991         if (unlikely(!tclass)) {
992                 if (policydb.allow_unknown)
993                         goto allow;
994                 goto out;
995         }
996
997         context_struct_compute_av(scontext, tcontext, tclass, avd);
998  out:
999         read_unlock(&policy_rwlock);
1000         return;
1001 allow:
1002         avd->allowed = 0xffffffff;
1003         goto out;
1004 }
1005
1006 /*
1007  * Write the security context string representation of
1008  * the context structure `context' into a dynamically
1009  * allocated string of the correct size.  Set `*scontext'
1010  * to point to this string and set `*scontext_len' to
1011  * the length of the string.
1012  */
1013 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1014 {
1015         char *scontextp;
1016
1017         if (scontext)
1018                 *scontext = NULL;
1019         *scontext_len = 0;
1020
1021         if (context->len) {
1022                 *scontext_len = context->len;
1023                 *scontext = kstrdup(context->str, GFP_ATOMIC);
1024                 if (!(*scontext))
1025                         return -ENOMEM;
1026                 return 0;
1027         }
1028
1029         /* Compute the size of the context. */
1030         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033         *scontext_len += mls_compute_context_len(context);
1034
1035         if (!scontext)
1036                 return 0;
1037
1038         /* Allocate space for the context; caller must free this space. */
1039         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040         if (!scontextp)
1041                 return -ENOMEM;
1042         *scontext = scontextp;
1043
1044         /*
1045          * Copy the user name, role name and type name into the context.
1046          */
1047         sprintf(scontextp, "%s:%s:%s",
1048                 sym_name(&policydb, SYM_USERS, context->user - 1),
1049                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054
1055         mls_sid_to_context(context, &scontextp);
1056
1057         *scontextp = 0;
1058
1059         return 0;
1060 }
1061
1062 #include "initial_sid_to_string.h"
1063
1064 const char *security_get_initial_sid_context(u32 sid)
1065 {
1066         if (unlikely(sid > SECINITSID_NUM))
1067                 return NULL;
1068         return initial_sid_to_string[sid];
1069 }
1070
1071 static int security_sid_to_context_core(u32 sid, char **scontext,
1072                                         u32 *scontext_len, int force)
1073 {
1074         struct context *context;
1075         int rc = 0;
1076
1077         if (scontext)
1078                 *scontext = NULL;
1079         *scontext_len  = 0;
1080
1081         if (!ss_initialized) {
1082                 if (sid <= SECINITSID_NUM) {
1083                         char *scontextp;
1084
1085                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086                         if (!scontext)
1087                                 goto out;
1088                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089                         if (!scontextp) {
1090                                 rc = -ENOMEM;
1091                                 goto out;
1092                         }
1093                         strcpy(scontextp, initial_sid_to_string[sid]);
1094                         *scontext = scontextp;
1095                         goto out;
1096                 }
1097                 printk(KERN_ERR "SELinux: %s:  called before initial "
1098                        "load_policy on unknown SID %d\n", __func__, sid);
1099                 rc = -EINVAL;
1100                 goto out;
1101         }
1102         read_lock(&policy_rwlock);
1103         if (force)
1104                 context = sidtab_search_force(&sidtab, sid);
1105         else
1106                 context = sidtab_search(&sidtab, sid);
1107         if (!context) {
1108                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1109                         __func__, sid);
1110                 rc = -EINVAL;
1111                 goto out_unlock;
1112         }
1113         rc = context_struct_to_string(context, scontext, scontext_len);
1114 out_unlock:
1115         read_unlock(&policy_rwlock);
1116 out:
1117         return rc;
1118
1119 }
1120
1121 /**
1122  * security_sid_to_context - Obtain a context for a given SID.
1123  * @sid: security identifier, SID
1124  * @scontext: security context
1125  * @scontext_len: length in bytes
1126  *
1127  * Write the string representation of the context associated with @sid
1128  * into a dynamically allocated string of the correct size.  Set @scontext
1129  * to point to this string and set @scontext_len to the length of the string.
1130  */
1131 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132 {
1133         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134 }
1135
1136 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137 {
1138         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139 }
1140
1141 /*
1142  * Caveat:  Mutates scontext.
1143  */
1144 static int string_to_context_struct(struct policydb *pol,
1145                                     struct sidtab *sidtabp,
1146                                     char *scontext,
1147                                     u32 scontext_len,
1148                                     struct context *ctx,
1149                                     u32 def_sid)
1150 {
1151         struct role_datum *role;
1152         struct type_datum *typdatum;
1153         struct user_datum *usrdatum;
1154         char *scontextp, *p, oldc;
1155         int rc = 0;
1156
1157         context_init(ctx);
1158
1159         /* Parse the security context. */
1160
1161         rc = -EINVAL;
1162         scontextp = (char *) scontext;
1163
1164         /* Extract the user. */
1165         p = scontextp;
1166         while (*p && *p != ':')
1167                 p++;
1168
1169         if (*p == 0)
1170                 goto out;
1171
1172         *p++ = 0;
1173
1174         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175         if (!usrdatum)
1176                 goto out;
1177
1178         ctx->user = usrdatum->value;
1179
1180         /* Extract role. */
1181         scontextp = p;
1182         while (*p && *p != ':')
1183                 p++;
1184
1185         if (*p == 0)
1186                 goto out;
1187
1188         *p++ = 0;
1189
1190         role = hashtab_search(pol->p_roles.table, scontextp);
1191         if (!role)
1192                 goto out;
1193         ctx->role = role->value;
1194
1195         /* Extract type. */
1196         scontextp = p;
1197         while (*p && *p != ':')
1198                 p++;
1199         oldc = *p;
1200         *p++ = 0;
1201
1202         typdatum = hashtab_search(pol->p_types.table, scontextp);
1203         if (!typdatum || typdatum->attribute)
1204                 goto out;
1205
1206         ctx->type = typdatum->value;
1207
1208         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209         if (rc)
1210                 goto out;
1211
1212         rc = -EINVAL;
1213         if ((p - scontext) < scontext_len)
1214                 goto out;
1215
1216         /* Check the validity of the new context. */
1217         if (!policydb_context_isvalid(pol, ctx))
1218                 goto out;
1219         rc = 0;
1220 out:
1221         if (rc)
1222                 context_destroy(ctx);
1223         return rc;
1224 }
1225
1226 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228                                         int force)
1229 {
1230         char *scontext2, *str = NULL;
1231         struct context context;
1232         int rc = 0;
1233
1234         if (!ss_initialized) {
1235                 int i;
1236
1237                 for (i = 1; i < SECINITSID_NUM; i++) {
1238                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1239                                 *sid = i;
1240                                 return 0;
1241                         }
1242                 }
1243                 *sid = SECINITSID_KERNEL;
1244                 return 0;
1245         }
1246         *sid = SECSID_NULL;
1247
1248         /* Copy the string so that we can modify the copy as we parse it. */
1249         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1250         if (!scontext2)
1251                 return -ENOMEM;
1252         memcpy(scontext2, scontext, scontext_len);
1253         scontext2[scontext_len] = 0;
1254
1255         if (force) {
1256                 /* Save another copy for storing in uninterpreted form */
1257                 rc = -ENOMEM;
1258                 str = kstrdup(scontext2, gfp_flags);
1259                 if (!str)
1260                         goto out;
1261         }
1262
1263         read_lock(&policy_rwlock);
1264         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1265                                       scontext_len, &context, def_sid);
1266         if (rc == -EINVAL && force) {
1267                 context.str = str;
1268                 context.len = scontext_len;
1269                 str = NULL;
1270         } else if (rc)
1271                 goto out_unlock;
1272         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1273         context_destroy(&context);
1274 out_unlock:
1275         read_unlock(&policy_rwlock);
1276 out:
1277         kfree(scontext2);
1278         kfree(str);
1279         return rc;
1280 }
1281
1282 /**
1283  * security_context_to_sid - Obtain a SID for a given security context.
1284  * @scontext: security context
1285  * @scontext_len: length in bytes
1286  * @sid: security identifier, SID
1287  *
1288  * Obtains a SID associated with the security context that
1289  * has the string representation specified by @scontext.
1290  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1291  * memory is available, or 0 on success.
1292  */
1293 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1294 {
1295         return security_context_to_sid_core(scontext, scontext_len,
1296                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1297 }
1298
1299 /**
1300  * security_context_to_sid_default - Obtain a SID for a given security context,
1301  * falling back to specified default if needed.
1302  *
1303  * @scontext: security context
1304  * @scontext_len: length in bytes
1305  * @sid: security identifier, SID
1306  * @def_sid: default SID to assign on error
1307  *
1308  * Obtains a SID associated with the security context that
1309  * has the string representation specified by @scontext.
1310  * The default SID is passed to the MLS layer to be used to allow
1311  * kernel labeling of the MLS field if the MLS field is not present
1312  * (for upgrading to MLS without full relabel).
1313  * Implicitly forces adding of the context even if it cannot be mapped yet.
1314  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1315  * memory is available, or 0 on success.
1316  */
1317 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1318                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1319 {
1320         return security_context_to_sid_core(scontext, scontext_len,
1321                                             sid, def_sid, gfp_flags, 1);
1322 }
1323
1324 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1325                                   u32 *sid)
1326 {
1327         return security_context_to_sid_core(scontext, scontext_len,
1328                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1329 }
1330
1331 static int compute_sid_handle_invalid_context(
1332         struct context *scontext,
1333         struct context *tcontext,
1334         u16 tclass,
1335         struct context *newcontext)
1336 {
1337         char *s = NULL, *t = NULL, *n = NULL;
1338         u32 slen, tlen, nlen;
1339
1340         if (context_struct_to_string(scontext, &s, &slen))
1341                 goto out;
1342         if (context_struct_to_string(tcontext, &t, &tlen))
1343                 goto out;
1344         if (context_struct_to_string(newcontext, &n, &nlen))
1345                 goto out;
1346         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1347                   "security_compute_sid:  invalid context %s"
1348                   " for scontext=%s"
1349                   " tcontext=%s"
1350                   " tclass=%s",
1351                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1352 out:
1353         kfree(s);
1354         kfree(t);
1355         kfree(n);
1356         if (!selinux_enforcing)
1357                 return 0;
1358         return -EACCES;
1359 }
1360
1361 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1362                                   u32 scon, u32 tcon, u16 tclass,
1363                                   const char *objname)
1364 {
1365         struct filename_trans *ft;
1366         for (ft = p->filename_trans; ft; ft = ft->next) {
1367                 if (ft->stype == scon &&
1368                     ft->ttype == tcon &&
1369                     ft->tclass == tclass &&
1370                     !strcmp(ft->name, objname)) {
1371                         newcontext->type = ft->otype;
1372                         return;
1373                 }
1374         }
1375 }
1376
1377 static int security_compute_sid(u32 ssid,
1378                                 u32 tsid,
1379                                 u16 orig_tclass,
1380                                 u32 specified,
1381                                 const char *objname,
1382                                 u32 *out_sid,
1383                                 bool kern)
1384 {
1385         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1386         struct role_trans *roletr = NULL;
1387         struct avtab_key avkey;
1388         struct avtab_datum *avdatum;
1389         struct avtab_node *node;
1390         u16 tclass;
1391         int rc = 0;
1392         bool sock;
1393
1394         if (!ss_initialized) {
1395                 switch (orig_tclass) {
1396                 case SECCLASS_PROCESS: /* kernel value */
1397                         *out_sid = ssid;
1398                         break;
1399                 default:
1400                         *out_sid = tsid;
1401                         break;
1402                 }
1403                 goto out;
1404         }
1405
1406         context_init(&newcontext);
1407
1408         read_lock(&policy_rwlock);
1409
1410         if (kern) {
1411                 tclass = unmap_class(orig_tclass);
1412                 sock = security_is_socket_class(orig_tclass);
1413         } else {
1414                 tclass = orig_tclass;
1415                 sock = security_is_socket_class(map_class(tclass));
1416         }
1417
1418         scontext = sidtab_search(&sidtab, ssid);
1419         if (!scontext) {
1420                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1421                        __func__, ssid);
1422                 rc = -EINVAL;
1423                 goto out_unlock;
1424         }
1425         tcontext = sidtab_search(&sidtab, tsid);
1426         if (!tcontext) {
1427                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1428                        __func__, tsid);
1429                 rc = -EINVAL;
1430                 goto out_unlock;
1431         }
1432
1433         /* Set the user identity. */
1434         switch (specified) {
1435         case AVTAB_TRANSITION:
1436         case AVTAB_CHANGE:
1437                 /* Use the process user identity. */
1438                 newcontext.user = scontext->user;
1439                 break;
1440         case AVTAB_MEMBER:
1441                 /* Use the related object owner. */
1442                 newcontext.user = tcontext->user;
1443                 break;
1444         }
1445
1446         /* Set the role and type to default values. */
1447         if ((tclass == policydb.process_class) || (sock == true)) {
1448                 /* Use the current role and type of process. */
1449                 newcontext.role = scontext->role;
1450                 newcontext.type = scontext->type;
1451         } else {
1452                 /* Use the well-defined object role. */
1453                 newcontext.role = OBJECT_R_VAL;
1454                 /* Use the type of the related object. */
1455                 newcontext.type = tcontext->type;
1456         }
1457
1458         /* Look for a type transition/member/change rule. */
1459         avkey.source_type = scontext->type;
1460         avkey.target_type = tcontext->type;
1461         avkey.target_class = tclass;
1462         avkey.specified = specified;
1463         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1464
1465         /* If no permanent rule, also check for enabled conditional rules */
1466         if (!avdatum) {
1467                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1468                 for (; node; node = avtab_search_node_next(node, specified)) {
1469                         if (node->key.specified & AVTAB_ENABLED) {
1470                                 avdatum = &node->datum;
1471                                 break;
1472                         }
1473                 }
1474         }
1475
1476         if (avdatum) {
1477                 /* Use the type from the type transition/member/change rule. */
1478                 newcontext.type = avdatum->data;
1479         }
1480
1481         /* if we have a qstr this is a file trans check so check those rules */
1482         if (objname)
1483                 filename_compute_type(&policydb, &newcontext, scontext->type,
1484                                       tcontext->type, tclass, objname);
1485
1486         /* Check for class-specific changes. */
1487         if (specified & AVTAB_TRANSITION) {
1488                 /* Look for a role transition rule. */
1489                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1490                         if ((roletr->role == scontext->role) &&
1491                             (roletr->type == tcontext->type) &&
1492                             (roletr->tclass == tclass)) {
1493                                 /* Use the role transition rule. */
1494                                 newcontext.role = roletr->new_role;
1495                                 break;
1496                         }
1497                 }
1498         }
1499
1500         /* Set the MLS attributes.
1501            This is done last because it may allocate memory. */
1502         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1503                              &newcontext, sock);
1504         if (rc)
1505                 goto out_unlock;
1506
1507         /* Check the validity of the context. */
1508         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1509                 rc = compute_sid_handle_invalid_context(scontext,
1510                                                         tcontext,
1511                                                         tclass,
1512                                                         &newcontext);
1513                 if (rc)
1514                         goto out_unlock;
1515         }
1516         /* Obtain the sid for the context. */
1517         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1518 out_unlock:
1519         read_unlock(&policy_rwlock);
1520         context_destroy(&newcontext);
1521 out:
1522         return rc;
1523 }
1524
1525 /**
1526  * security_transition_sid - Compute the SID for a new subject/object.
1527  * @ssid: source security identifier
1528  * @tsid: target security identifier
1529  * @tclass: target security class
1530  * @out_sid: security identifier for new subject/object
1531  *
1532  * Compute a SID to use for labeling a new subject or object in the
1533  * class @tclass based on a SID pair (@ssid, @tsid).
1534  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1535  * if insufficient memory is available, or %0 if the new SID was
1536  * computed successfully.
1537  */
1538 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1539                             const struct qstr *qstr, u32 *out_sid)
1540 {
1541         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1542                                     qstr ? qstr->name : NULL, out_sid, true);
1543 }
1544
1545 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1546                                  const char *objname, u32 *out_sid)
1547 {
1548         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1549                                     objname, out_sid, false);
1550 }
1551
1552 /**
1553  * security_member_sid - Compute the SID for member selection.
1554  * @ssid: source security identifier
1555  * @tsid: target security identifier
1556  * @tclass: target security class
1557  * @out_sid: security identifier for selected member
1558  *
1559  * Compute a SID to use when selecting a member of a polyinstantiated
1560  * object of class @tclass based on a SID pair (@ssid, @tsid).
1561  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1562  * if insufficient memory is available, or %0 if the SID was
1563  * computed successfully.
1564  */
1565 int security_member_sid(u32 ssid,
1566                         u32 tsid,
1567                         u16 tclass,
1568                         u32 *out_sid)
1569 {
1570         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1571                                     out_sid, false);
1572 }
1573
1574 /**
1575  * security_change_sid - Compute the SID for object relabeling.
1576  * @ssid: source security identifier
1577  * @tsid: target security identifier
1578  * @tclass: target security class
1579  * @out_sid: security identifier for selected member
1580  *
1581  * Compute a SID to use for relabeling an object of class @tclass
1582  * based on a SID pair (@ssid, @tsid).
1583  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1584  * if insufficient memory is available, or %0 if the SID was
1585  * computed successfully.
1586  */
1587 int security_change_sid(u32 ssid,
1588                         u32 tsid,
1589                         u16 tclass,
1590                         u32 *out_sid)
1591 {
1592         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1593                                     out_sid, false);
1594 }
1595
1596 /* Clone the SID into the new SID table. */
1597 static int clone_sid(u32 sid,
1598                      struct context *context,
1599                      void *arg)
1600 {
1601         struct sidtab *s = arg;
1602
1603         if (sid > SECINITSID_NUM)
1604                 return sidtab_insert(s, sid, context);
1605         else
1606                 return 0;
1607 }
1608
1609 static inline int convert_context_handle_invalid_context(struct context *context)
1610 {
1611         char *s;
1612         u32 len;
1613
1614         if (selinux_enforcing)
1615                 return -EINVAL;
1616
1617         if (!context_struct_to_string(context, &s, &len)) {
1618                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1619                 kfree(s);
1620         }
1621         return 0;
1622 }
1623
1624 struct convert_context_args {
1625         struct policydb *oldp;
1626         struct policydb *newp;
1627 };
1628
1629 /*
1630  * Convert the values in the security context
1631  * structure `c' from the values specified
1632  * in the policy `p->oldp' to the values specified
1633  * in the policy `p->newp'.  Verify that the
1634  * context is valid under the new policy.
1635  */
1636 static int convert_context(u32 key,
1637                            struct context *c,
1638                            void *p)
1639 {
1640         struct convert_context_args *args;
1641         struct context oldc;
1642         struct ocontext *oc;
1643         struct mls_range *range;
1644         struct role_datum *role;
1645         struct type_datum *typdatum;
1646         struct user_datum *usrdatum;
1647         char *s;
1648         u32 len;
1649         int rc = 0;
1650
1651         if (key <= SECINITSID_NUM)
1652                 goto out;
1653
1654         args = p;
1655
1656         if (c->str) {
1657                 struct context ctx;
1658
1659                 rc = -ENOMEM;
1660                 s = kstrdup(c->str, GFP_KERNEL);
1661                 if (!s)
1662                         goto out;
1663
1664                 rc = string_to_context_struct(args->newp, NULL, s,
1665                                               c->len, &ctx, SECSID_NULL);
1666                 kfree(s);
1667                 if (!rc) {
1668                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1669                                c->str);
1670                         /* Replace string with mapped representation. */
1671                         kfree(c->str);
1672                         memcpy(c, &ctx, sizeof(*c));
1673                         goto out;
1674                 } else if (rc == -EINVAL) {
1675                         /* Retain string representation for later mapping. */
1676                         rc = 0;
1677                         goto out;
1678                 } else {
1679                         /* Other error condition, e.g. ENOMEM. */
1680                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1681                                c->str, -rc);
1682                         goto out;
1683                 }
1684         }
1685
1686         rc = context_cpy(&oldc, c);
1687         if (rc)
1688                 goto out;
1689
1690         /* Convert the user. */
1691         rc = -EINVAL;
1692         usrdatum = hashtab_search(args->newp->p_users.table,
1693                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1694         if (!usrdatum)
1695                 goto bad;
1696         c->user = usrdatum->value;
1697
1698         /* Convert the role. */
1699         rc = -EINVAL;
1700         role = hashtab_search(args->newp->p_roles.table,
1701                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1702         if (!role)
1703                 goto bad;
1704         c->role = role->value;
1705
1706         /* Convert the type. */
1707         rc = -EINVAL;
1708         typdatum = hashtab_search(args->newp->p_types.table,
1709                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1710         if (!typdatum)
1711                 goto bad;
1712         c->type = typdatum->value;
1713
1714         /* Convert the MLS fields if dealing with MLS policies */
1715         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1716                 rc = mls_convert_context(args->oldp, args->newp, c);
1717                 if (rc)
1718                         goto bad;
1719         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1720                 /*
1721                  * Switching between MLS and non-MLS policy:
1722                  * free any storage used by the MLS fields in the
1723                  * context for all existing entries in the sidtab.
1724                  */
1725                 mls_context_destroy(c);
1726         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1727                 /*
1728                  * Switching between non-MLS and MLS policy:
1729                  * ensure that the MLS fields of the context for all
1730                  * existing entries in the sidtab are filled in with a
1731                  * suitable default value, likely taken from one of the
1732                  * initial SIDs.
1733                  */
1734                 oc = args->newp->ocontexts[OCON_ISID];
1735                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1736                         oc = oc->next;
1737                 rc = -EINVAL;
1738                 if (!oc) {
1739                         printk(KERN_ERR "SELinux:  unable to look up"
1740                                 " the initial SIDs list\n");
1741                         goto bad;
1742                 }
1743                 range = &oc->context[0].range;
1744                 rc = mls_range_set(c, range);
1745                 if (rc)
1746                         goto bad;
1747         }
1748
1749         /* Check the validity of the new context. */
1750         if (!policydb_context_isvalid(args->newp, c)) {
1751                 rc = convert_context_handle_invalid_context(&oldc);
1752                 if (rc)
1753                         goto bad;
1754         }
1755
1756         context_destroy(&oldc);
1757
1758         rc = 0;
1759 out:
1760         return rc;
1761 bad:
1762         /* Map old representation to string and save it. */
1763         rc = context_struct_to_string(&oldc, &s, &len);
1764         if (rc)
1765                 return rc;
1766         context_destroy(&oldc);
1767         context_destroy(c);
1768         c->str = s;
1769         c->len = len;
1770         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1771                c->str);
1772         rc = 0;
1773         goto out;
1774 }
1775
1776 static void security_load_policycaps(void)
1777 {
1778         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1779                                                   POLICYDB_CAPABILITY_NETPEER);
1780         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1781                                                   POLICYDB_CAPABILITY_OPENPERM);
1782 }
1783
1784 extern void selinux_complete_init(void);
1785 static int security_preserve_bools(struct policydb *p);
1786
1787 /**
1788  * security_load_policy - Load a security policy configuration.
1789  * @data: binary policy data
1790  * @len: length of data in bytes
1791  *
1792  * Load a new set of security policy configuration data,
1793  * validate it and convert the SID table as necessary.
1794  * This function will flush the access vector cache after
1795  * loading the new policy.
1796  */
1797 int security_load_policy(void *data, size_t len)
1798 {
1799         struct policydb oldpolicydb, newpolicydb;
1800         struct sidtab oldsidtab, newsidtab;
1801         struct selinux_mapping *oldmap, *map = NULL;
1802         struct convert_context_args args;
1803         u32 seqno;
1804         u16 map_size;
1805         int rc = 0;
1806         struct policy_file file = { data, len }, *fp = &file;
1807
1808         if (!ss_initialized) {
1809                 avtab_cache_init();
1810                 rc = policydb_read(&policydb, fp);
1811                 if (rc) {
1812                         avtab_cache_destroy();
1813                         return rc;
1814                 }
1815
1816                 policydb.len = len;
1817                 rc = selinux_set_mapping(&policydb, secclass_map,
1818                                          &current_mapping,
1819                                          &current_mapping_size);
1820                 if (rc) {
1821                         policydb_destroy(&policydb);
1822                         avtab_cache_destroy();
1823                         return rc;
1824                 }
1825
1826                 rc = policydb_load_isids(&policydb, &sidtab);
1827                 if (rc) {
1828                         policydb_destroy(&policydb);
1829                         avtab_cache_destroy();
1830                         return rc;
1831                 }
1832
1833                 security_load_policycaps();
1834                 ss_initialized = 1;
1835                 seqno = ++latest_granting;
1836                 selinux_complete_init();
1837                 avc_ss_reset(seqno);
1838                 selnl_notify_policyload(seqno);
1839                 selinux_status_update_policyload(seqno);
1840                 selinux_netlbl_cache_invalidate();
1841                 selinux_xfrm_notify_policyload();
1842                 return 0;
1843         }
1844
1845 #if 0
1846         sidtab_hash_eval(&sidtab, "sids");
1847 #endif
1848
1849         rc = policydb_read(&newpolicydb, fp);
1850         if (rc)
1851                 return rc;
1852
1853         newpolicydb.len = len;
1854         /* If switching between different policy types, log MLS status */
1855         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1856                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1857         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1858                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1859
1860         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1861         if (rc) {
1862                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1863                 policydb_destroy(&newpolicydb);
1864                 return rc;
1865         }
1866
1867         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1868         if (rc)
1869                 goto err;
1870
1871         rc = security_preserve_bools(&newpolicydb);
1872         if (rc) {
1873                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1874                 goto err;
1875         }
1876
1877         /* Clone the SID table. */
1878         sidtab_shutdown(&sidtab);
1879
1880         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1881         if (rc)
1882                 goto err;
1883
1884         /*
1885          * Convert the internal representations of contexts
1886          * in the new SID table.
1887          */
1888         args.oldp = &policydb;
1889         args.newp = &newpolicydb;
1890         rc = sidtab_map(&newsidtab, convert_context, &args);
1891         if (rc) {
1892                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1893                         " representation of contexts in the new SID"
1894                         " table\n");
1895                 goto err;
1896         }
1897
1898         /* Save the old policydb and SID table to free later. */
1899         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1900         sidtab_set(&oldsidtab, &sidtab);
1901
1902         /* Install the new policydb and SID table. */
1903         write_lock_irq(&policy_rwlock);
1904         memcpy(&policydb, &newpolicydb, sizeof policydb);
1905         sidtab_set(&sidtab, &newsidtab);
1906         security_load_policycaps();
1907         oldmap = current_mapping;
1908         current_mapping = map;
1909         current_mapping_size = map_size;
1910         seqno = ++latest_granting;
1911         write_unlock_irq(&policy_rwlock);
1912
1913         /* Free the old policydb and SID table. */
1914         policydb_destroy(&oldpolicydb);
1915         sidtab_destroy(&oldsidtab);
1916         kfree(oldmap);
1917
1918         avc_ss_reset(seqno);
1919         selnl_notify_policyload(seqno);
1920         selinux_status_update_policyload(seqno);
1921         selinux_netlbl_cache_invalidate();
1922         selinux_xfrm_notify_policyload();
1923
1924         return 0;
1925
1926 err:
1927         kfree(map);
1928         sidtab_destroy(&newsidtab);
1929         policydb_destroy(&newpolicydb);
1930         return rc;
1931
1932 }
1933
1934 size_t security_policydb_len(void)
1935 {
1936         size_t len;
1937
1938         read_lock(&policy_rwlock);
1939         len = policydb.len;
1940         read_unlock(&policy_rwlock);
1941
1942         return len;
1943 }
1944
1945 /**
1946  * security_port_sid - Obtain the SID for a port.
1947  * @protocol: protocol number
1948  * @port: port number
1949  * @out_sid: security identifier
1950  */
1951 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1952 {
1953         struct ocontext *c;
1954         int rc = 0;
1955
1956         read_lock(&policy_rwlock);
1957
1958         c = policydb.ocontexts[OCON_PORT];
1959         while (c) {
1960                 if (c->u.port.protocol == protocol &&
1961                     c->u.port.low_port <= port &&
1962                     c->u.port.high_port >= port)
1963                         break;
1964                 c = c->next;
1965         }
1966
1967         if (c) {
1968                 if (!c->sid[0]) {
1969                         rc = sidtab_context_to_sid(&sidtab,
1970                                                    &c->context[0],
1971                                                    &c->sid[0]);
1972                         if (rc)
1973                                 goto out;
1974                 }
1975                 *out_sid = c->sid[0];
1976         } else {
1977                 *out_sid = SECINITSID_PORT;
1978         }
1979
1980 out:
1981         read_unlock(&policy_rwlock);
1982         return rc;
1983 }
1984
1985 /**
1986  * security_netif_sid - Obtain the SID for a network interface.
1987  * @name: interface name
1988  * @if_sid: interface SID
1989  */
1990 int security_netif_sid(char *name, u32 *if_sid)
1991 {
1992         int rc = 0;
1993         struct ocontext *c;
1994
1995         read_lock(&policy_rwlock);
1996
1997         c = policydb.ocontexts[OCON_NETIF];
1998         while (c) {
1999                 if (strcmp(name, c->u.name) == 0)
2000                         break;
2001                 c = c->next;
2002         }
2003
2004         if (c) {
2005                 if (!c->sid[0] || !c->sid[1]) {
2006                         rc = sidtab_context_to_sid(&sidtab,
2007                                                   &c->context[0],
2008                                                   &c->sid[0]);
2009                         if (rc)
2010                                 goto out;
2011                         rc = sidtab_context_to_sid(&sidtab,
2012                                                    &c->context[1],
2013                                                    &c->sid[1]);
2014                         if (rc)
2015                                 goto out;
2016                 }
2017                 *if_sid = c->sid[0];
2018         } else
2019                 *if_sid = SECINITSID_NETIF;
2020
2021 out:
2022         read_unlock(&policy_rwlock);
2023         return rc;
2024 }
2025
2026 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2027 {
2028         int i, fail = 0;
2029
2030         for (i = 0; i < 4; i++)
2031                 if (addr[i] != (input[i] & mask[i])) {
2032                         fail = 1;
2033                         break;
2034                 }
2035
2036         return !fail;
2037 }
2038
2039 /**
2040  * security_node_sid - Obtain the SID for a node (host).
2041  * @domain: communication domain aka address family
2042  * @addrp: address
2043  * @addrlen: address length in bytes
2044  * @out_sid: security identifier
2045  */
2046 int security_node_sid(u16 domain,
2047                       void *addrp,
2048                       u32 addrlen,
2049                       u32 *out_sid)
2050 {
2051         int rc;
2052         struct ocontext *c;
2053
2054         read_lock(&policy_rwlock);
2055
2056         switch (domain) {
2057         case AF_INET: {
2058                 u32 addr;
2059
2060                 rc = -EINVAL;
2061                 if (addrlen != sizeof(u32))
2062                         goto out;
2063
2064                 addr = *((u32 *)addrp);
2065
2066                 c = policydb.ocontexts[OCON_NODE];
2067                 while (c) {
2068                         if (c->u.node.addr == (addr & c->u.node.mask))
2069                                 break;
2070                         c = c->next;
2071                 }
2072                 break;
2073         }
2074
2075         case AF_INET6:
2076                 rc = -EINVAL;
2077                 if (addrlen != sizeof(u64) * 2)
2078                         goto out;
2079                 c = policydb.ocontexts[OCON_NODE6];
2080                 while (c) {
2081                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2082                                                 c->u.node6.mask))
2083                                 break;
2084                         c = c->next;
2085                 }
2086                 break;
2087
2088         default:
2089                 rc = 0;
2090                 *out_sid = SECINITSID_NODE;
2091                 goto out;
2092         }
2093
2094         if (c) {
2095                 if (!c->sid[0]) {
2096                         rc = sidtab_context_to_sid(&sidtab,
2097                                                    &c->context[0],
2098                                                    &c->sid[0]);
2099                         if (rc)
2100                                 goto out;
2101                 }
2102                 *out_sid = c->sid[0];
2103         } else {
2104                 *out_sid = SECINITSID_NODE;
2105         }
2106
2107         rc = 0;
2108 out:
2109         read_unlock(&policy_rwlock);
2110         return rc;
2111 }
2112
2113 #define SIDS_NEL 25
2114
2115 /**
2116  * security_get_user_sids - Obtain reachable SIDs for a user.
2117  * @fromsid: starting SID
2118  * @username: username
2119  * @sids: array of reachable SIDs for user
2120  * @nel: number of elements in @sids
2121  *
2122  * Generate the set of SIDs for legal security contexts
2123  * for a given user that can be reached by @fromsid.
2124  * Set *@sids to point to a dynamically allocated
2125  * array containing the set of SIDs.  Set *@nel to the
2126  * number of elements in the array.
2127  */
2128
2129 int security_get_user_sids(u32 fromsid,
2130                            char *username,
2131                            u32 **sids,
2132                            u32 *nel)
2133 {
2134         struct context *fromcon, usercon;
2135         u32 *mysids = NULL, *mysids2, sid;
2136         u32 mynel = 0, maxnel = SIDS_NEL;
2137         struct user_datum *user;
2138         struct role_datum *role;
2139         struct ebitmap_node *rnode, *tnode;
2140         int rc = 0, i, j;
2141
2142         *sids = NULL;
2143         *nel = 0;
2144
2145         if (!ss_initialized)
2146                 goto out;
2147
2148         read_lock(&policy_rwlock);
2149
2150         context_init(&usercon);
2151
2152         rc = -EINVAL;
2153         fromcon = sidtab_search(&sidtab, fromsid);
2154         if (!fromcon)
2155                 goto out_unlock;
2156
2157         rc = -EINVAL;
2158         user = hashtab_search(policydb.p_users.table, username);
2159         if (!user)
2160                 goto out_unlock;
2161
2162         usercon.user = user->value;
2163
2164         rc = -ENOMEM;
2165         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2166         if (!mysids)
2167                 goto out_unlock;
2168
2169         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2170                 role = policydb.role_val_to_struct[i];
2171                 usercon.role = i + 1;
2172                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2173                         usercon.type = j + 1;
2174
2175                         if (mls_setup_user_range(fromcon, user, &usercon))
2176                                 continue;
2177
2178                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2179                         if (rc)
2180                                 goto out_unlock;
2181                         if (mynel < maxnel) {
2182                                 mysids[mynel++] = sid;
2183                         } else {
2184                                 rc = -ENOMEM;
2185                                 maxnel += SIDS_NEL;
2186                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2187                                 if (!mysids2)
2188                                         goto out_unlock;
2189                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2190                                 kfree(mysids);
2191                                 mysids = mysids2;
2192                                 mysids[mynel++] = sid;
2193                         }
2194                 }
2195         }
2196         rc = 0;
2197 out_unlock:
2198         read_unlock(&policy_rwlock);
2199         if (rc || !mynel) {
2200                 kfree(mysids);
2201                 goto out;
2202         }
2203
2204         rc = -ENOMEM;
2205         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2206         if (!mysids2) {
2207                 kfree(mysids);
2208                 goto out;
2209         }
2210         for (i = 0, j = 0; i < mynel; i++) {
2211                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2212                                           SECCLASS_PROCESS, /* kernel value */
2213                                           PROCESS__TRANSITION, AVC_STRICT,
2214                                           NULL);
2215                 if (!rc)
2216                         mysids2[j++] = mysids[i];
2217                 cond_resched();
2218         }
2219         rc = 0;
2220         kfree(mysids);
2221         *sids = mysids2;
2222         *nel = j;
2223 out:
2224         return rc;
2225 }
2226
2227 /**
2228  * security_genfs_sid - Obtain a SID for a file in a filesystem
2229  * @fstype: filesystem type
2230  * @path: path from root of mount
2231  * @sclass: file security class
2232  * @sid: SID for path
2233  *
2234  * Obtain a SID to use for a file in a filesystem that
2235  * cannot support xattr or use a fixed labeling behavior like
2236  * transition SIDs or task SIDs.
2237  */
2238 int security_genfs_sid(const char *fstype,
2239                        char *path,
2240                        u16 orig_sclass,
2241                        u32 *sid)
2242 {
2243         int len;
2244         u16 sclass;
2245         struct genfs *genfs;
2246         struct ocontext *c;
2247         int rc, cmp = 0;
2248
2249         while (path[0] == '/' && path[1] == '/')
2250                 path++;
2251
2252         read_lock(&policy_rwlock);
2253
2254         sclass = unmap_class(orig_sclass);
2255         *sid = SECINITSID_UNLABELED;
2256
2257         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2258                 cmp = strcmp(fstype, genfs->fstype);
2259                 if (cmp <= 0)
2260                         break;
2261         }
2262
2263         rc = -ENOENT;
2264         if (!genfs || cmp)
2265                 goto out;
2266
2267         for (c = genfs->head; c; c = c->next) {
2268                 len = strlen(c->u.name);
2269                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2270                     (strncmp(c->u.name, path, len) == 0))
2271                         break;
2272         }
2273
2274         rc = -ENOENT;
2275         if (!c)
2276                 goto out;
2277
2278         if (!c->sid[0]) {
2279                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2280                 if (rc)
2281                         goto out;
2282         }
2283
2284         *sid = c->sid[0];
2285         rc = 0;
2286 out:
2287         read_unlock(&policy_rwlock);
2288         return rc;
2289 }
2290
2291 /**
2292  * security_fs_use - Determine how to handle labeling for a filesystem.
2293  * @fstype: filesystem type
2294  * @behavior: labeling behavior
2295  * @sid: SID for filesystem (superblock)
2296  */
2297 int security_fs_use(
2298         const char *fstype,
2299         unsigned int *behavior,
2300         u32 *sid)
2301 {
2302         int rc = 0;
2303         struct ocontext *c;
2304
2305         read_lock(&policy_rwlock);
2306
2307         c = policydb.ocontexts[OCON_FSUSE];
2308         while (c) {
2309                 if (strcmp(fstype, c->u.name) == 0)
2310                         break;
2311                 c = c->next;
2312         }
2313
2314         if (c) {
2315                 *behavior = c->v.behavior;
2316                 if (!c->sid[0]) {
2317                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2318                                                    &c->sid[0]);
2319                         if (rc)
2320                                 goto out;
2321                 }
2322                 *sid = c->sid[0];
2323         } else {
2324                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2325                 if (rc) {
2326                         *behavior = SECURITY_FS_USE_NONE;
2327                         rc = 0;
2328                 } else {
2329                         *behavior = SECURITY_FS_USE_GENFS;
2330                 }
2331         }
2332
2333 out:
2334         read_unlock(&policy_rwlock);
2335         return rc;
2336 }
2337
2338 int security_get_bools(int *len, char ***names, int **values)
2339 {
2340         int i, rc;
2341
2342         read_lock(&policy_rwlock);
2343         *names = NULL;
2344         *values = NULL;
2345
2346         rc = 0;
2347         *len = policydb.p_bools.nprim;
2348         if (!*len)
2349                 goto out;
2350
2351         rc = -ENOMEM;
2352         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2353         if (!*names)
2354                 goto err;
2355
2356         rc = -ENOMEM;
2357         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2358         if (!*values)
2359                 goto err;
2360
2361         for (i = 0; i < *len; i++) {
2362                 size_t name_len;
2363
2364                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2365                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2366
2367                 rc = -ENOMEM;
2368                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2369                 if (!(*names)[i])
2370                         goto err;
2371
2372                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2373                 (*names)[i][name_len - 1] = 0;
2374         }
2375         rc = 0;
2376 out:
2377         read_unlock(&policy_rwlock);
2378         return rc;
2379 err:
2380         if (*names) {
2381                 for (i = 0; i < *len; i++)
2382                         kfree((*names)[i]);
2383         }
2384         kfree(*values);
2385         goto out;
2386 }
2387
2388
2389 int security_set_bools(int len, int *values)
2390 {
2391         int i, rc;
2392         int lenp, seqno = 0;
2393         struct cond_node *cur;
2394
2395         write_lock_irq(&policy_rwlock);
2396
2397         rc = -EFAULT;
2398         lenp = policydb.p_bools.nprim;
2399         if (len != lenp)
2400                 goto out;
2401
2402         for (i = 0; i < len; i++) {
2403                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2404                         audit_log(current->audit_context, GFP_ATOMIC,
2405                                 AUDIT_MAC_CONFIG_CHANGE,
2406                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2407                                 sym_name(&policydb, SYM_BOOLS, i),
2408                                 !!values[i],
2409                                 policydb.bool_val_to_struct[i]->state,
2410                                 audit_get_loginuid(current),
2411                                 audit_get_sessionid(current));
2412                 }
2413                 if (values[i])
2414                         policydb.bool_val_to_struct[i]->state = 1;
2415                 else
2416                         policydb.bool_val_to_struct[i]->state = 0;
2417         }
2418
2419         for (cur = policydb.cond_list; cur; cur = cur->next) {
2420                 rc = evaluate_cond_node(&policydb, cur);
2421                 if (rc)
2422                         goto out;
2423         }
2424
2425         seqno = ++latest_granting;
2426         rc = 0;
2427 out:
2428         write_unlock_irq(&policy_rwlock);
2429         if (!rc) {
2430                 avc_ss_reset(seqno);
2431                 selnl_notify_policyload(seqno);
2432                 selinux_status_update_policyload(seqno);
2433                 selinux_xfrm_notify_policyload();
2434         }
2435         return rc;
2436 }
2437
2438 int security_get_bool_value(int bool)
2439 {
2440         int rc;
2441         int len;
2442
2443         read_lock(&policy_rwlock);
2444
2445         rc = -EFAULT;
2446         len = policydb.p_bools.nprim;
2447         if (bool >= len)
2448                 goto out;
2449
2450         rc = policydb.bool_val_to_struct[bool]->state;
2451 out:
2452         read_unlock(&policy_rwlock);
2453         return rc;
2454 }
2455
2456 static int security_preserve_bools(struct policydb *p)
2457 {
2458         int rc, nbools = 0, *bvalues = NULL, i;
2459         char **bnames = NULL;
2460         struct cond_bool_datum *booldatum;
2461         struct cond_node *cur;
2462
2463         rc = security_get_bools(&nbools, &bnames, &bvalues);
2464         if (rc)
2465                 goto out;
2466         for (i = 0; i < nbools; i++) {
2467                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2468                 if (booldatum)
2469                         booldatum->state = bvalues[i];
2470         }
2471         for (cur = p->cond_list; cur; cur = cur->next) {
2472                 rc = evaluate_cond_node(p, cur);
2473                 if (rc)
2474                         goto out;
2475         }
2476
2477 out:
2478         if (bnames) {
2479                 for (i = 0; i < nbools; i++)
2480                         kfree(bnames[i]);
2481         }
2482         kfree(bnames);
2483         kfree(bvalues);
2484         return rc;
2485 }
2486
2487 /*
2488  * security_sid_mls_copy() - computes a new sid based on the given
2489  * sid and the mls portion of mls_sid.
2490  */
2491 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2492 {
2493         struct context *context1;
2494         struct context *context2;
2495         struct context newcon;
2496         char *s;
2497         u32 len;
2498         int rc;
2499
2500         rc = 0;
2501         if (!ss_initialized || !policydb.mls_enabled) {
2502                 *new_sid = sid;
2503                 goto out;
2504         }
2505
2506         context_init(&newcon);
2507
2508         read_lock(&policy_rwlock);
2509
2510         rc = -EINVAL;
2511         context1 = sidtab_search(&sidtab, sid);
2512         if (!context1) {
2513                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2514                         __func__, sid);
2515                 goto out_unlock;
2516         }
2517
2518         rc = -EINVAL;
2519         context2 = sidtab_search(&sidtab, mls_sid);
2520         if (!context2) {
2521                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2522                         __func__, mls_sid);
2523                 goto out_unlock;
2524         }
2525
2526         newcon.user = context1->user;
2527         newcon.role = context1->role;
2528         newcon.type = context1->type;
2529         rc = mls_context_cpy(&newcon, context2);
2530         if (rc)
2531                 goto out_unlock;
2532
2533         /* Check the validity of the new context. */
2534         if (!policydb_context_isvalid(&policydb, &newcon)) {
2535                 rc = convert_context_handle_invalid_context(&newcon);
2536                 if (rc) {
2537                         if (!context_struct_to_string(&newcon, &s, &len)) {
2538                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2539                                           "security_sid_mls_copy: invalid context %s", s);
2540                                 kfree(s);
2541                         }
2542                         goto out_unlock;
2543                 }
2544         }
2545
2546         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2547 out_unlock:
2548         read_unlock(&policy_rwlock);
2549         context_destroy(&newcon);
2550 out:
2551         return rc;
2552 }
2553
2554 /**
2555  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2556  * @nlbl_sid: NetLabel SID
2557  * @nlbl_type: NetLabel labeling protocol type
2558  * @xfrm_sid: XFRM SID
2559  *
2560  * Description:
2561  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2562  * resolved into a single SID it is returned via @peer_sid and the function
2563  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2564  * returns a negative value.  A table summarizing the behavior is below:
2565  *
2566  *                                 | function return |      @sid
2567  *   ------------------------------+-----------------+-----------------
2568  *   no peer labels                |        0        |    SECSID_NULL
2569  *   single peer label             |        0        |    <peer_label>
2570  *   multiple, consistent labels   |        0        |    <peer_label>
2571  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2572  *
2573  */
2574 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2575                                  u32 xfrm_sid,
2576                                  u32 *peer_sid)
2577 {
2578         int rc;
2579         struct context *nlbl_ctx;
2580         struct context *xfrm_ctx;
2581
2582         *peer_sid = SECSID_NULL;
2583
2584         /* handle the common (which also happens to be the set of easy) cases
2585          * right away, these two if statements catch everything involving a
2586          * single or absent peer SID/label */
2587         if (xfrm_sid == SECSID_NULL) {
2588                 *peer_sid = nlbl_sid;
2589                 return 0;
2590         }
2591         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2592          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2593          * is present */
2594         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2595                 *peer_sid = xfrm_sid;
2596                 return 0;
2597         }
2598
2599         /* we don't need to check ss_initialized here since the only way both
2600          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2601          * security server was initialized and ss_initialized was true */
2602         if (!policydb.mls_enabled)
2603                 return 0;
2604
2605         read_lock(&policy_rwlock);
2606
2607         rc = -EINVAL;
2608         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2609         if (!nlbl_ctx) {
2610                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2611                        __func__, nlbl_sid);
2612                 goto out;
2613         }
2614         rc = -EINVAL;
2615         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2616         if (!xfrm_ctx) {
2617                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2618                        __func__, xfrm_sid);
2619                 goto out;
2620         }
2621         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2622         if (rc)
2623                 goto out;
2624
2625         /* at present NetLabel SIDs/labels really only carry MLS
2626          * information so if the MLS portion of the NetLabel SID
2627          * matches the MLS portion of the labeled XFRM SID/label
2628          * then pass along the XFRM SID as it is the most
2629          * expressive */
2630         *peer_sid = xfrm_sid;
2631 out:
2632         read_unlock(&policy_rwlock);
2633         return rc;
2634 }
2635
2636 static int get_classes_callback(void *k, void *d, void *args)
2637 {
2638         struct class_datum *datum = d;
2639         char *name = k, **classes = args;
2640         int value = datum->value - 1;
2641
2642         classes[value] = kstrdup(name, GFP_ATOMIC);
2643         if (!classes[value])
2644                 return -ENOMEM;
2645
2646         return 0;
2647 }
2648
2649 int security_get_classes(char ***classes, int *nclasses)
2650 {
2651         int rc;
2652
2653         read_lock(&policy_rwlock);
2654
2655         rc = -ENOMEM;
2656         *nclasses = policydb.p_classes.nprim;
2657         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2658         if (!*classes)
2659                 goto out;
2660
2661         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2662                         *classes);
2663         if (rc) {
2664                 int i;
2665                 for (i = 0; i < *nclasses; i++)
2666                         kfree((*classes)[i]);
2667                 kfree(*classes);
2668         }
2669
2670 out:
2671         read_unlock(&policy_rwlock);
2672         return rc;
2673 }
2674
2675 static int get_permissions_callback(void *k, void *d, void *args)
2676 {
2677         struct perm_datum *datum = d;
2678         char *name = k, **perms = args;
2679         int value = datum->value - 1;
2680
2681         perms[value] = kstrdup(name, GFP_ATOMIC);
2682         if (!perms[value])
2683                 return -ENOMEM;
2684
2685         return 0;
2686 }
2687
2688 int security_get_permissions(char *class, char ***perms, int *nperms)
2689 {
2690         int rc, i;
2691         struct class_datum *match;
2692
2693         read_lock(&policy_rwlock);
2694
2695         rc = -EINVAL;
2696         match = hashtab_search(policydb.p_classes.table, class);
2697         if (!match) {
2698                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2699                         __func__, class);
2700                 goto out;
2701         }
2702
2703         rc = -ENOMEM;
2704         *nperms = match->permissions.nprim;
2705         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2706         if (!*perms)
2707                 goto out;
2708
2709         if (match->comdatum) {
2710                 rc = hashtab_map(match->comdatum->permissions.table,
2711                                 get_permissions_callback, *perms);
2712                 if (rc)
2713                         goto err;
2714         }
2715
2716         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2717                         *perms);
2718         if (rc)
2719                 goto err;
2720
2721 out:
2722         read_unlock(&policy_rwlock);
2723         return rc;
2724
2725 err:
2726         read_unlock(&policy_rwlock);
2727         for (i = 0; i < *nperms; i++)
2728                 kfree((*perms)[i]);
2729         kfree(*perms);
2730         return rc;
2731 }
2732
2733 int security_get_reject_unknown(void)
2734 {
2735         return policydb.reject_unknown;
2736 }
2737
2738 int security_get_allow_unknown(void)
2739 {
2740         return policydb.allow_unknown;
2741 }
2742
2743 /**
2744  * security_policycap_supported - Check for a specific policy capability
2745  * @req_cap: capability
2746  *
2747  * Description:
2748  * This function queries the currently loaded policy to see if it supports the
2749  * capability specified by @req_cap.  Returns true (1) if the capability is
2750  * supported, false (0) if it isn't supported.
2751  *
2752  */
2753 int security_policycap_supported(unsigned int req_cap)
2754 {
2755         int rc;
2756
2757         read_lock(&policy_rwlock);
2758         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2759         read_unlock(&policy_rwlock);
2760
2761         return rc;
2762 }
2763
2764 struct selinux_audit_rule {
2765         u32 au_seqno;
2766         struct context au_ctxt;
2767 };
2768
2769 void selinux_audit_rule_free(void *vrule)
2770 {
2771         struct selinux_audit_rule *rule = vrule;
2772
2773         if (rule) {
2774                 context_destroy(&rule->au_ctxt);
2775                 kfree(rule);
2776         }
2777 }
2778
2779 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2780 {
2781         struct selinux_audit_rule *tmprule;
2782         struct role_datum *roledatum;
2783         struct type_datum *typedatum;
2784         struct user_datum *userdatum;
2785         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2786         int rc = 0;
2787
2788         *rule = NULL;
2789
2790         if (!ss_initialized)
2791                 return -EOPNOTSUPP;
2792
2793         switch (field) {
2794         case AUDIT_SUBJ_USER:
2795         case AUDIT_SUBJ_ROLE:
2796         case AUDIT_SUBJ_TYPE:
2797         case AUDIT_OBJ_USER:
2798         case AUDIT_OBJ_ROLE:
2799         case AUDIT_OBJ_TYPE:
2800                 /* only 'equals' and 'not equals' fit user, role, and type */
2801                 if (op != Audit_equal && op != Audit_not_equal)
2802                         return -EINVAL;
2803                 break;
2804         case AUDIT_SUBJ_SEN:
2805         case AUDIT_SUBJ_CLR:
2806         case AUDIT_OBJ_LEV_LOW:
2807         case AUDIT_OBJ_LEV_HIGH:
2808                 /* we do not allow a range, indicated by the presense of '-' */
2809                 if (strchr(rulestr, '-'))
2810                         return -EINVAL;
2811                 break;
2812         default:
2813                 /* only the above fields are valid */
2814                 return -EINVAL;
2815         }
2816
2817         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2818         if (!tmprule)
2819                 return -ENOMEM;
2820
2821         context_init(&tmprule->au_ctxt);
2822
2823         read_lock(&policy_rwlock);
2824
2825         tmprule->au_seqno = latest_granting;
2826
2827         switch (field) {
2828         case AUDIT_SUBJ_USER:
2829         case AUDIT_OBJ_USER:
2830                 rc = -EINVAL;
2831                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2832                 if (!userdatum)
2833                         goto out;
2834                 tmprule->au_ctxt.user = userdatum->value;
2835                 break;
2836         case AUDIT_SUBJ_ROLE:
2837         case AUDIT_OBJ_ROLE:
2838                 rc = -EINVAL;
2839                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2840                 if (!roledatum)
2841                         goto out;
2842                 tmprule->au_ctxt.role = roledatum->value;
2843                 break;
2844         case AUDIT_SUBJ_TYPE:
2845         case AUDIT_OBJ_TYPE:
2846                 rc = -EINVAL;
2847                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2848                 if (!typedatum)
2849                         goto out;
2850                 tmprule->au_ctxt.type = typedatum->value;
2851                 break;
2852         case AUDIT_SUBJ_SEN:
2853         case AUDIT_SUBJ_CLR:
2854         case AUDIT_OBJ_LEV_LOW:
2855         case AUDIT_OBJ_LEV_HIGH:
2856                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2857                 if (rc)
2858                         goto out;
2859                 break;
2860         }
2861         rc = 0;
2862 out:
2863         read_unlock(&policy_rwlock);
2864
2865         if (rc) {
2866                 selinux_audit_rule_free(tmprule);
2867                 tmprule = NULL;
2868         }
2869
2870         *rule = tmprule;
2871
2872         return rc;
2873 }
2874
2875 /* Check to see if the rule contains any selinux fields */
2876 int selinux_audit_rule_known(struct audit_krule *rule)
2877 {
2878         int i;
2879
2880         for (i = 0; i < rule->field_count; i++) {
2881                 struct audit_field *f = &rule->fields[i];
2882                 switch (f->type) {
2883                 case AUDIT_SUBJ_USER:
2884                 case AUDIT_SUBJ_ROLE:
2885                 case AUDIT_SUBJ_TYPE:
2886                 case AUDIT_SUBJ_SEN:
2887                 case AUDIT_SUBJ_CLR:
2888                 case AUDIT_OBJ_USER:
2889                 case AUDIT_OBJ_ROLE:
2890                 case AUDIT_OBJ_TYPE:
2891                 case AUDIT_OBJ_LEV_LOW:
2892                 case AUDIT_OBJ_LEV_HIGH:
2893                         return 1;
2894                 }
2895         }
2896
2897         return 0;
2898 }
2899
2900 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2901                              struct audit_context *actx)
2902 {
2903         struct context *ctxt;
2904         struct mls_level *level;
2905         struct selinux_audit_rule *rule = vrule;
2906         int match = 0;
2907
2908         if (!rule) {
2909                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2910                           "selinux_audit_rule_match: missing rule\n");
2911                 return -ENOENT;
2912         }
2913
2914         read_lock(&policy_rwlock);
2915
2916         if (rule->au_seqno < latest_granting) {
2917                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2918                           "selinux_audit_rule_match: stale rule\n");
2919                 match = -ESTALE;
2920                 goto out;
2921         }
2922
2923         ctxt = sidtab_search(&sidtab, sid);
2924         if (!ctxt) {
2925                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2926                           "selinux_audit_rule_match: unrecognized SID %d\n",
2927                           sid);
2928                 match = -ENOENT;
2929                 goto out;
2930         }
2931
2932         /* a field/op pair that is not caught here will simply fall through
2933            without a match */
2934         switch (field) {
2935         case AUDIT_SUBJ_USER:
2936         case AUDIT_OBJ_USER:
2937                 switch (op) {
2938                 case Audit_equal:
2939                         match = (ctxt->user == rule->au_ctxt.user);
2940                         break;
2941                 case Audit_not_equal:
2942                         match = (ctxt->user != rule->au_ctxt.user);
2943                         break;
2944                 }
2945                 break;
2946         case AUDIT_SUBJ_ROLE:
2947         case AUDIT_OBJ_ROLE:
2948                 switch (op) {
2949                 case Audit_equal:
2950                         match = (ctxt->role == rule->au_ctxt.role);
2951                         break;
2952                 case Audit_not_equal:
2953                         match = (ctxt->role != rule->au_ctxt.role);
2954                         break;
2955                 }
2956                 break;
2957         case AUDIT_SUBJ_TYPE:
2958         case AUDIT_OBJ_TYPE:
2959                 switch (op) {
2960                 case Audit_equal:
2961                         match = (ctxt->type == rule->au_ctxt.type);
2962                         break;
2963                 case Audit_not_equal:
2964                         match = (ctxt->type != rule->au_ctxt.type);
2965                         break;
2966                 }
2967                 break;
2968         case AUDIT_SUBJ_SEN:
2969         case AUDIT_SUBJ_CLR:
2970         case AUDIT_OBJ_LEV_LOW:
2971         case AUDIT_OBJ_LEV_HIGH:
2972                 level = ((field == AUDIT_SUBJ_SEN ||
2973                           field == AUDIT_OBJ_LEV_LOW) ?
2974                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2975                 switch (op) {
2976                 case Audit_equal:
2977                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2978                                              level);
2979                         break;
2980                 case Audit_not_equal:
2981                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2982                                               level);
2983                         break;
2984                 case Audit_lt:
2985                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2986                                                level) &&
2987                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2988                                                level));
2989                         break;
2990                 case Audit_le:
2991                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2992                                               level);
2993                         break;
2994                 case Audit_gt:
2995                         match = (mls_level_dom(level,
2996                                               &rule->au_ctxt.range.level[0]) &&
2997                                  !mls_level_eq(level,
2998                                                &rule->au_ctxt.range.level[0]));
2999                         break;
3000                 case Audit_ge:
3001                         match = mls_level_dom(level,
3002                                               &rule->au_ctxt.range.level[0]);
3003                         break;
3004                 }
3005         }
3006
3007 out:
3008         read_unlock(&policy_rwlock);
3009         return match;
3010 }
3011
3012 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3013
3014 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3015                                u16 class, u32 perms, u32 *retained)
3016 {
3017         int err = 0;
3018
3019         if (event == AVC_CALLBACK_RESET && aurule_callback)
3020                 err = aurule_callback();
3021         return err;
3022 }
3023
3024 static int __init aurule_init(void)
3025 {
3026         int err;
3027
3028         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3029                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3030         if (err)
3031                 panic("avc_add_callback() failed, error %d\n", err);
3032
3033         return err;
3034 }
3035 __initcall(aurule_init);
3036
3037 #ifdef CONFIG_NETLABEL
3038 /**
3039  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3040  * @secattr: the NetLabel packet security attributes
3041  * @sid: the SELinux SID
3042  *
3043  * Description:
3044  * Attempt to cache the context in @ctx, which was derived from the packet in
3045  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3046  * already been initialized.
3047  *
3048  */
3049 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3050                                       u32 sid)
3051 {
3052         u32 *sid_cache;
3053
3054         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3055         if (sid_cache == NULL)
3056                 return;
3057         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3058         if (secattr->cache == NULL) {
3059                 kfree(sid_cache);
3060                 return;
3061         }
3062
3063         *sid_cache = sid;
3064         secattr->cache->free = kfree;
3065         secattr->cache->data = sid_cache;
3066         secattr->flags |= NETLBL_SECATTR_CACHE;
3067 }
3068
3069 /**
3070  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3071  * @secattr: the NetLabel packet security attributes
3072  * @sid: the SELinux SID
3073  *
3074  * Description:
3075  * Convert the given NetLabel security attributes in @secattr into a
3076  * SELinux SID.  If the @secattr field does not contain a full SELinux
3077  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
3078  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3079  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3080  * conversion for future lookups.  Returns zero on success, negative values on
3081  * failure.
3082  *
3083  */
3084 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3085                                    u32 *sid)
3086 {
3087         int rc;
3088         struct context *ctx;
3089         struct context ctx_new;
3090
3091         if (!ss_initialized) {
3092                 *sid = SECSID_NULL;
3093                 return 0;
3094         }
3095
3096         read_lock(&policy_rwlock);
3097
3098         if (secattr->flags & NETLBL_SECATTR_CACHE)
3099                 *sid = *(u32 *)secattr->cache->data;
3100         else if (secattr->flags & NETLBL_SECATTR_SECID)
3101                 *sid = secattr->attr.secid;
3102         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3103                 rc = -EIDRM;
3104                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3105                 if (ctx == NULL)
3106                         goto out;
3107
3108                 context_init(&ctx_new);
3109                 ctx_new.user = ctx->user;
3110                 ctx_new.role = ctx->role;
3111                 ctx_new.type = ctx->type;
3112                 mls_import_netlbl_lvl(&ctx_new, secattr);
3113                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3114                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3115                                                    secattr->attr.mls.cat);
3116                         if (rc)
3117                                 goto out;
3118                         memcpy(&ctx_new.range.level[1].cat,
3119                                &ctx_new.range.level[0].cat,
3120                                sizeof(ctx_new.range.level[0].cat));
3121                 }
3122                 rc = -EIDRM;
3123                 if (!mls_context_isvalid(&policydb, &ctx_new))
3124                         goto out_free;
3125
3126                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3127                 if (rc)
3128                         goto out_free;
3129
3130                 security_netlbl_cache_add(secattr, *sid);
3131
3132                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3133         } else
3134                 *sid = SECSID_NULL;
3135
3136         read_unlock(&policy_rwlock);
3137         return 0;
3138 out_free:
3139         ebitmap_destroy(&ctx_new.range.level[0].cat);
3140 out:
3141         read_unlock(&policy_rwlock);
3142         return rc;
3143 }
3144
3145 /**
3146  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3147  * @sid: the SELinux SID
3148  * @secattr: the NetLabel packet security attributes
3149  *
3150  * Description:
3151  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3152  * Returns zero on success, negative values on failure.
3153  *
3154  */
3155 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3156 {
3157         int rc;
3158         struct context *ctx;
3159
3160         if (!ss_initialized)
3161                 return 0;
3162
3163         read_lock(&policy_rwlock);
3164
3165         rc = -ENOENT;
3166         ctx = sidtab_search(&sidtab, sid);
3167         if (ctx == NULL)
3168                 goto out;
3169
3170         rc = -ENOMEM;
3171         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3172                                   GFP_ATOMIC);
3173         if (secattr->domain == NULL)
3174                 goto out;
3175
3176         secattr->attr.secid = sid;
3177         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3178         mls_export_netlbl_lvl(ctx, secattr);
3179         rc = mls_export_netlbl_cat(ctx, secattr);
3180 out:
3181         read_unlock(&policy_rwlock);
3182         return rc;
3183 }
3184 #endif /* CONFIG_NETLABEL */
3185
3186 /**
3187  * security_read_policy - read the policy.
3188  * @data: binary policy data
3189  * @len: length of data in bytes
3190  *
3191  */
3192 int security_read_policy(void **data, ssize_t *len)
3193 {
3194         int rc;
3195         struct policy_file fp;
3196
3197         if (!ss_initialized)
3198                 return -EINVAL;
3199
3200         *len = security_policydb_len();
3201
3202         *data = vmalloc_user(*len);
3203         if (!*data)
3204                 return -ENOMEM;
3205
3206         fp.data = *data;
3207         fp.len = *len;
3208
3209         read_lock(&policy_rwlock);
3210         rc = policydb_write(&policydb, &fp);
3211         read_unlock(&policy_rwlock);
3212
3213         if (rc)
3214                 return rc;
3215
3216         *len = (unsigned long)fp.data - (unsigned long)*data;
3217         return 0;
3218
3219 }