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