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