0696aadcab6f85d07633536c063e8b798ddcd60c
[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  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
26  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
27  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
28  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
29  *      This program is free software; you can redistribute it and/or modify
30  *      it under the terms of the GNU General Public License as published by
31  *      the Free Software Foundation, version 2.
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/string.h>
36 #include <linux/spinlock.h>
37 #include <linux/rcupdate.h>
38 #include <linux/errno.h>
39 #include <linux/in.h>
40 #include <linux/sched.h>
41 #include <linux/audit.h>
42 #include <linux/mutex.h>
43 #include <linux/selinux.h>
44 #include <net/netlabel.h>
45
46 #include "flask.h"
47 #include "avc.h"
48 #include "avc_ss.h"
49 #include "security.h"
50 #include "context.h"
51 #include "policydb.h"
52 #include "sidtab.h"
53 #include "services.h"
54 #include "conditional.h"
55 #include "mls.h"
56 #include "objsec.h"
57 #include "netlabel.h"
58 #include "xfrm.h"
59 #include "ebitmap.h"
60 #include "audit.h"
61
62 extern void selnl_notify_policyload(u32 seqno);
63 unsigned int policydb_loaded_version;
64
65 int selinux_policycap_netpeer;
66 int selinux_policycap_openperm;
67
68 /*
69  * This is declared in avc.c
70  */
71 extern const struct selinux_class_perm selinux_class_perm;
72
73 static DEFINE_RWLOCK(policy_rwlock);
74 #define POLICY_RDLOCK read_lock(&policy_rwlock)
75 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
76 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
77 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
78
79 static DEFINE_MUTEX(load_mutex);
80 #define LOAD_LOCK mutex_lock(&load_mutex)
81 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
82
83 static struct sidtab sidtab;
84 struct policydb policydb;
85 int ss_initialized;
86
87 /*
88  * The largest sequence number that has been used when
89  * providing an access decision to the access vector cache.
90  * The sequence number only changes when a policy change
91  * occurs.
92  */
93 static u32 latest_granting;
94
95 /* Forward declaration. */
96 static int context_struct_to_string(struct context *context, char **scontext,
97                                     u32 *scontext_len);
98
99 /*
100  * Return the boolean value of a constraint expression
101  * when it is applied to the specified source and target
102  * security contexts.
103  *
104  * xcontext is a special beast...  It is used by the validatetrans rules
105  * only.  For these rules, scontext is the context before the transition,
106  * tcontext is the context after the transition, and xcontext is the context
107  * of the process performing the transition.  All other callers of
108  * constraint_expr_eval should pass in NULL for xcontext.
109  */
110 static int constraint_expr_eval(struct context *scontext,
111                                 struct context *tcontext,
112                                 struct context *xcontext,
113                                 struct constraint_expr *cexpr)
114 {
115         u32 val1, val2;
116         struct context *c;
117         struct role_datum *r1, *r2;
118         struct mls_level *l1, *l2;
119         struct constraint_expr *e;
120         int s[CEXPR_MAXDEPTH];
121         int sp = -1;
122
123         for (e = cexpr; e; e = e->next) {
124                 switch (e->expr_type) {
125                 case CEXPR_NOT:
126                         BUG_ON(sp < 0);
127                         s[sp] = !s[sp];
128                         break;
129                 case CEXPR_AND:
130                         BUG_ON(sp < 1);
131                         sp--;
132                         s[sp] &= s[sp+1];
133                         break;
134                 case CEXPR_OR:
135                         BUG_ON(sp < 1);
136                         sp--;
137                         s[sp] |= s[sp+1];
138                         break;
139                 case CEXPR_ATTR:
140                         if (sp == (CEXPR_MAXDEPTH-1))
141                                 return 0;
142                         switch (e->attr) {
143                         case CEXPR_USER:
144                                 val1 = scontext->user;
145                                 val2 = tcontext->user;
146                                 break;
147                         case CEXPR_TYPE:
148                                 val1 = scontext->type;
149                                 val2 = tcontext->type;
150                                 break;
151                         case CEXPR_ROLE:
152                                 val1 = scontext->role;
153                                 val2 = tcontext->role;
154                                 r1 = policydb.role_val_to_struct[val1 - 1];
155                                 r2 = policydb.role_val_to_struct[val2 - 1];
156                                 switch (e->op) {
157                                 case CEXPR_DOM:
158                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
159                                                                   val2 - 1);
160                                         continue;
161                                 case CEXPR_DOMBY:
162                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
163                                                                   val1 - 1);
164                                         continue;
165                                 case CEXPR_INCOMP:
166                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
167                                                                     val2 - 1) &&
168                                                    !ebitmap_get_bit(&r2->dominates,
169                                                                     val1 - 1));
170                                         continue;
171                                 default:
172                                         break;
173                                 }
174                                 break;
175                         case CEXPR_L1L2:
176                                 l1 = &(scontext->range.level[0]);
177                                 l2 = &(tcontext->range.level[0]);
178                                 goto mls_ops;
179                         case CEXPR_L1H2:
180                                 l1 = &(scontext->range.level[0]);
181                                 l2 = &(tcontext->range.level[1]);
182                                 goto mls_ops;
183                         case CEXPR_H1L2:
184                                 l1 = &(scontext->range.level[1]);
185                                 l2 = &(tcontext->range.level[0]);
186                                 goto mls_ops;
187                         case CEXPR_H1H2:
188                                 l1 = &(scontext->range.level[1]);
189                                 l2 = &(tcontext->range.level[1]);
190                                 goto mls_ops;
191                         case CEXPR_L1H1:
192                                 l1 = &(scontext->range.level[0]);
193                                 l2 = &(scontext->range.level[1]);
194                                 goto mls_ops;
195                         case CEXPR_L2H2:
196                                 l1 = &(tcontext->range.level[0]);
197                                 l2 = &(tcontext->range.level[1]);
198                                 goto mls_ops;
199 mls_ops:
200                         switch (e->op) {
201                         case CEXPR_EQ:
202                                 s[++sp] = mls_level_eq(l1, l2);
203                                 continue;
204                         case CEXPR_NEQ:
205                                 s[++sp] = !mls_level_eq(l1, l2);
206                                 continue;
207                         case CEXPR_DOM:
208                                 s[++sp] = mls_level_dom(l1, l2);
209                                 continue;
210                         case CEXPR_DOMBY:
211                                 s[++sp] = mls_level_dom(l2, l1);
212                                 continue;
213                         case CEXPR_INCOMP:
214                                 s[++sp] = mls_level_incomp(l2, l1);
215                                 continue;
216                         default:
217                                 BUG();
218                                 return 0;
219                         }
220                         break;
221                         default:
222                                 BUG();
223                                 return 0;
224                         }
225
226                         switch (e->op) {
227                         case CEXPR_EQ:
228                                 s[++sp] = (val1 == val2);
229                                 break;
230                         case CEXPR_NEQ:
231                                 s[++sp] = (val1 != val2);
232                                 break;
233                         default:
234                                 BUG();
235                                 return 0;
236                         }
237                         break;
238                 case CEXPR_NAMES:
239                         if (sp == (CEXPR_MAXDEPTH-1))
240                                 return 0;
241                         c = scontext;
242                         if (e->attr & CEXPR_TARGET)
243                                 c = tcontext;
244                         else if (e->attr & CEXPR_XTARGET) {
245                                 c = xcontext;
246                                 if (!c) {
247                                         BUG();
248                                         return 0;
249                                 }
250                         }
251                         if (e->attr & CEXPR_USER)
252                                 val1 = c->user;
253                         else if (e->attr & CEXPR_ROLE)
254                                 val1 = c->role;
255                         else if (e->attr & CEXPR_TYPE)
256                                 val1 = c->type;
257                         else {
258                                 BUG();
259                                 return 0;
260                         }
261
262                         switch (e->op) {
263                         case CEXPR_EQ:
264                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
265                                 break;
266                         case CEXPR_NEQ:
267                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
268                                 break;
269                         default:
270                                 BUG();
271                                 return 0;
272                         }
273                         break;
274                 default:
275                         BUG();
276                         return 0;
277                 }
278         }
279
280         BUG_ON(sp != 0);
281         return s[0];
282 }
283
284 /*
285  * Compute access vectors based on a context structure pair for
286  * the permissions in a particular class.
287  */
288 static int context_struct_compute_av(struct context *scontext,
289                                      struct context *tcontext,
290                                      u16 tclass,
291                                      u32 requested,
292                                      struct av_decision *avd)
293 {
294         struct constraint_node *constraint;
295         struct role_allow *ra;
296         struct avtab_key avkey;
297         struct avtab_node *node;
298         struct class_datum *tclass_datum;
299         struct ebitmap *sattr, *tattr;
300         struct ebitmap_node *snode, *tnode;
301         const struct selinux_class_perm *kdefs = &selinux_class_perm;
302         unsigned int i, j;
303
304         /*
305          * Remap extended Netlink classes for old policy versions.
306          * Do this here rather than socket_type_to_security_class()
307          * in case a newer policy version is loaded, allowing sockets
308          * to remain in the correct class.
309          */
310         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
311                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
312                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
313                         tclass = SECCLASS_NETLINK_SOCKET;
314
315         /*
316          * Initialize the access vectors to the default values.
317          */
318         avd->allowed = 0;
319         avd->decided = 0xffffffff;
320         avd->auditallow = 0;
321         avd->auditdeny = 0xffffffff;
322         avd->seqno = latest_granting;
323
324         /*
325          * Check for all the invalid cases.
326          * - tclass 0
327          * - tclass > policy and > kernel
328          * - tclass > policy but is a userspace class
329          * - tclass > policy but we do not allow unknowns
330          */
331         if (unlikely(!tclass))
332                 goto inval_class;
333         if (unlikely(tclass > policydb.p_classes.nprim))
334                 if (tclass > kdefs->cts_len ||
335                     !kdefs->class_to_string[tclass - 1] ||
336                     !policydb.allow_unknown)
337                         goto inval_class;
338
339         /*
340          * Kernel class and we allow unknown so pad the allow decision
341          * the pad will be all 1 for unknown classes.
342          */
343         if (tclass <= kdefs->cts_len && policydb.allow_unknown)
344                 avd->allowed = policydb.undefined_perms[tclass - 1];
345
346         /*
347          * Not in policy. Since decision is completed (all 1 or all 0) return.
348          */
349         if (unlikely(tclass > policydb.p_classes.nprim))
350                 return 0;
351
352         tclass_datum = policydb.class_val_to_struct[tclass - 1];
353
354         /*
355          * If a specific type enforcement rule was defined for
356          * this permission check, then use it.
357          */
358         avkey.target_class = tclass;
359         avkey.specified = AVTAB_AV;
360         sattr = &policydb.type_attr_map[scontext->type - 1];
361         tattr = &policydb.type_attr_map[tcontext->type - 1];
362         ebitmap_for_each_positive_bit(sattr, snode, i) {
363                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
364                         avkey.source_type = i + 1;
365                         avkey.target_type = j + 1;
366                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
367                              node != NULL;
368                              node = avtab_search_node_next(node, avkey.specified)) {
369                                 if (node->key.specified == AVTAB_ALLOWED)
370                                         avd->allowed |= node->datum.data;
371                                 else if (node->key.specified == AVTAB_AUDITALLOW)
372                                         avd->auditallow |= node->datum.data;
373                                 else if (node->key.specified == AVTAB_AUDITDENY)
374                                         avd->auditdeny &= node->datum.data;
375                         }
376
377                         /* Check conditional av table for additional permissions */
378                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
379
380                 }
381         }
382
383         /*
384          * Remove any permissions prohibited by a constraint (this includes
385          * the MLS policy).
386          */
387         constraint = tclass_datum->constraints;
388         while (constraint) {
389                 if ((constraint->permissions & (avd->allowed)) &&
390                     !constraint_expr_eval(scontext, tcontext, NULL,
391                                           constraint->expr)) {
392                         avd->allowed = (avd->allowed) & ~(constraint->permissions);
393                 }
394                 constraint = constraint->next;
395         }
396
397         /*
398          * If checking process transition permission and the
399          * role is changing, then check the (current_role, new_role)
400          * pair.
401          */
402         if (tclass == SECCLASS_PROCESS &&
403             (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
404             scontext->role != tcontext->role) {
405                 for (ra = policydb.role_allow; ra; ra = ra->next) {
406                         if (scontext->role == ra->role &&
407                             tcontext->role == ra->new_role)
408                                 break;
409                 }
410                 if (!ra)
411                         avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
412                                                         PROCESS__DYNTRANSITION);
413         }
414
415         return 0;
416
417 inval_class:
418         printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n", __func__,
419                 tclass);
420         return -EINVAL;
421 }
422
423 /*
424  * Given a sid find if the type has the permissive flag set
425  */
426 int security_permissive_sid(u32 sid)
427 {
428         struct context *context;
429         u32 type;
430         int rc;
431
432         POLICY_RDLOCK;
433
434         context = sidtab_search(&sidtab, sid);
435         BUG_ON(!context);
436
437         type = context->type;
438         /*
439          * we are intentionally using type here, not type-1, the 0th bit may
440          * someday indicate that we are globally setting permissive in policy.
441          */
442         rc = ebitmap_get_bit(&policydb.permissive_map, type);
443
444         POLICY_RDUNLOCK;
445         return rc;
446 }
447
448 static int security_validtrans_handle_fail(struct context *ocontext,
449                                            struct context *ncontext,
450                                            struct context *tcontext,
451                                            u16 tclass)
452 {
453         char *o = NULL, *n = NULL, *t = NULL;
454         u32 olen, nlen, tlen;
455
456         if (context_struct_to_string(ocontext, &o, &olen) < 0)
457                 goto out;
458         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
459                 goto out;
460         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
461                 goto out;
462         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
463                   "security_validate_transition:  denied for"
464                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
465                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
466 out:
467         kfree(o);
468         kfree(n);
469         kfree(t);
470
471         if (!selinux_enforcing)
472                 return 0;
473         return -EPERM;
474 }
475
476 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
477                                  u16 tclass)
478 {
479         struct context *ocontext;
480         struct context *ncontext;
481         struct context *tcontext;
482         struct class_datum *tclass_datum;
483         struct constraint_node *constraint;
484         int rc = 0;
485
486         if (!ss_initialized)
487                 return 0;
488
489         POLICY_RDLOCK;
490
491         /*
492          * Remap extended Netlink classes for old policy versions.
493          * Do this here rather than socket_type_to_security_class()
494          * in case a newer policy version is loaded, allowing sockets
495          * to remain in the correct class.
496          */
497         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
498                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
499                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
500                         tclass = SECCLASS_NETLINK_SOCKET;
501
502         if (!tclass || tclass > policydb.p_classes.nprim) {
503                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
504                         __func__, tclass);
505                 rc = -EINVAL;
506                 goto out;
507         }
508         tclass_datum = policydb.class_val_to_struct[tclass - 1];
509
510         ocontext = sidtab_search(&sidtab, oldsid);
511         if (!ocontext) {
512                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
513                         __func__, oldsid);
514                 rc = -EINVAL;
515                 goto out;
516         }
517
518         ncontext = sidtab_search(&sidtab, newsid);
519         if (!ncontext) {
520                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
521                         __func__, newsid);
522                 rc = -EINVAL;
523                 goto out;
524         }
525
526         tcontext = sidtab_search(&sidtab, tasksid);
527         if (!tcontext) {
528                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
529                         __func__, tasksid);
530                 rc = -EINVAL;
531                 goto out;
532         }
533
534         constraint = tclass_datum->validatetrans;
535         while (constraint) {
536                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
537                                           constraint->expr)) {
538                         rc = security_validtrans_handle_fail(ocontext, ncontext,
539                                                              tcontext, tclass);
540                         goto out;
541                 }
542                 constraint = constraint->next;
543         }
544
545 out:
546         POLICY_RDUNLOCK;
547         return rc;
548 }
549
550 /**
551  * security_compute_av - Compute access vector decisions.
552  * @ssid: source security identifier
553  * @tsid: target security identifier
554  * @tclass: target security class
555  * @requested: requested permissions
556  * @avd: access vector decisions
557  *
558  * Compute a set of access vector decisions based on the
559  * SID pair (@ssid, @tsid) for the permissions in @tclass.
560  * Return -%EINVAL if any of the parameters are invalid or %0
561  * if the access vector decisions were computed successfully.
562  */
563 int security_compute_av(u32 ssid,
564                         u32 tsid,
565                         u16 tclass,
566                         u32 requested,
567                         struct av_decision *avd)
568 {
569         struct context *scontext = NULL, *tcontext = NULL;
570         int rc = 0;
571
572         if (!ss_initialized) {
573                 avd->allowed = 0xffffffff;
574                 avd->decided = 0xffffffff;
575                 avd->auditallow = 0;
576                 avd->auditdeny = 0xffffffff;
577                 avd->seqno = latest_granting;
578                 return 0;
579         }
580
581         POLICY_RDLOCK;
582
583         scontext = sidtab_search(&sidtab, ssid);
584         if (!scontext) {
585                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
586                        __func__, ssid);
587                 rc = -EINVAL;
588                 goto out;
589         }
590         tcontext = sidtab_search(&sidtab, tsid);
591         if (!tcontext) {
592                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
593                        __func__, tsid);
594                 rc = -EINVAL;
595                 goto out;
596         }
597
598         rc = context_struct_compute_av(scontext, tcontext, tclass,
599                                        requested, avd);
600 out:
601         POLICY_RDUNLOCK;
602         return rc;
603 }
604
605 /*
606  * Write the security context string representation of
607  * the context structure `context' into a dynamically
608  * allocated string of the correct size.  Set `*scontext'
609  * to point to this string and set `*scontext_len' to
610  * the length of the string.
611  */
612 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
613 {
614         char *scontextp;
615
616         *scontext = NULL;
617         *scontext_len = 0;
618
619         if (context->len) {
620                 *scontext_len = context->len;
621                 *scontext = kstrdup(context->str, GFP_ATOMIC);
622                 if (!(*scontext))
623                         return -ENOMEM;
624                 return 0;
625         }
626
627         /* Compute the size of the context. */
628         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
629         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
630         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
631         *scontext_len += mls_compute_context_len(context);
632
633         /* Allocate space for the context; caller must free this space. */
634         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
635         if (!scontextp)
636                 return -ENOMEM;
637         *scontext = scontextp;
638
639         /*
640          * Copy the user name, role name and type name into the context.
641          */
642         sprintf(scontextp, "%s:%s:%s",
643                 policydb.p_user_val_to_name[context->user - 1],
644                 policydb.p_role_val_to_name[context->role - 1],
645                 policydb.p_type_val_to_name[context->type - 1]);
646         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
647                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
648                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
649
650         mls_sid_to_context(context, &scontextp);
651
652         *scontextp = 0;
653
654         return 0;
655 }
656
657 #include "initial_sid_to_string.h"
658
659 const char *security_get_initial_sid_context(u32 sid)
660 {
661         if (unlikely(sid > SECINITSID_NUM))
662                 return NULL;
663         return initial_sid_to_string[sid];
664 }
665
666 static int security_sid_to_context_core(u32 sid, char **scontext,
667                                         u32 *scontext_len, int force)
668 {
669         struct context *context;
670         int rc = 0;
671
672         *scontext = NULL;
673         *scontext_len  = 0;
674
675         if (!ss_initialized) {
676                 if (sid <= SECINITSID_NUM) {
677                         char *scontextp;
678
679                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
680                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
681                         if (!scontextp) {
682                                 rc = -ENOMEM;
683                                 goto out;
684                         }
685                         strcpy(scontextp, initial_sid_to_string[sid]);
686                         *scontext = scontextp;
687                         goto out;
688                 }
689                 printk(KERN_ERR "SELinux: %s:  called before initial "
690                        "load_policy on unknown SID %d\n", __func__, sid);
691                 rc = -EINVAL;
692                 goto out;
693         }
694         POLICY_RDLOCK;
695         if (force)
696                 context = sidtab_search_force(&sidtab, sid);
697         else
698                 context = sidtab_search(&sidtab, sid);
699         if (!context) {
700                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
701                         __func__, sid);
702                 rc = -EINVAL;
703                 goto out_unlock;
704         }
705         rc = context_struct_to_string(context, scontext, scontext_len);
706 out_unlock:
707         POLICY_RDUNLOCK;
708 out:
709         return rc;
710
711 }
712
713 /**
714  * security_sid_to_context - Obtain a context for a given SID.
715  * @sid: security identifier, SID
716  * @scontext: security context
717  * @scontext_len: length in bytes
718  *
719  * Write the string representation of the context associated with @sid
720  * into a dynamically allocated string of the correct size.  Set @scontext
721  * to point to this string and set @scontext_len to the length of the string.
722  */
723 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
724 {
725         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
726 }
727
728 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
729 {
730         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
731 }
732
733 /*
734  * Caveat:  Mutates scontext.
735  */
736 static int string_to_context_struct(struct policydb *pol,
737                                     struct sidtab *sidtabp,
738                                     char *scontext,
739                                     u32 scontext_len,
740                                     struct context *ctx,
741                                     u32 def_sid)
742 {
743         struct role_datum *role;
744         struct type_datum *typdatum;
745         struct user_datum *usrdatum;
746         char *scontextp, *p, oldc;
747         int rc = 0;
748
749         context_init(ctx);
750
751         /* Parse the security context. */
752
753         rc = -EINVAL;
754         scontextp = (char *) scontext;
755
756         /* Extract the user. */
757         p = scontextp;
758         while (*p && *p != ':')
759                 p++;
760
761         if (*p == 0)
762                 goto out;
763
764         *p++ = 0;
765
766         usrdatum = hashtab_search(pol->p_users.table, scontextp);
767         if (!usrdatum)
768                 goto out;
769
770         ctx->user = usrdatum->value;
771
772         /* Extract role. */
773         scontextp = p;
774         while (*p && *p != ':')
775                 p++;
776
777         if (*p == 0)
778                 goto out;
779
780         *p++ = 0;
781
782         role = hashtab_search(pol->p_roles.table, scontextp);
783         if (!role)
784                 goto out;
785         ctx->role = role->value;
786
787         /* Extract type. */
788         scontextp = p;
789         while (*p && *p != ':')
790                 p++;
791         oldc = *p;
792         *p++ = 0;
793
794         typdatum = hashtab_search(pol->p_types.table, scontextp);
795         if (!typdatum)
796                 goto out;
797
798         ctx->type = typdatum->value;
799
800         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
801         if (rc)
802                 goto out;
803
804         if ((p - scontext) < scontext_len) {
805                 rc = -EINVAL;
806                 goto out;
807         }
808
809         /* Check the validity of the new context. */
810         if (!policydb_context_isvalid(pol, ctx)) {
811                 rc = -EINVAL;
812                 context_destroy(ctx);
813                 goto out;
814         }
815         rc = 0;
816 out:
817         return rc;
818 }
819
820 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
821                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
822                                         int force)
823 {
824         char *scontext2, *str = NULL;
825         struct context context;
826         int rc = 0;
827
828         if (!ss_initialized) {
829                 int i;
830
831                 for (i = 1; i < SECINITSID_NUM; i++) {
832                         if (!strcmp(initial_sid_to_string[i], scontext)) {
833                                 *sid = i;
834                                 return 0;
835                         }
836                 }
837                 *sid = SECINITSID_KERNEL;
838                 return 0;
839         }
840         *sid = SECSID_NULL;
841
842         /* Copy the string so that we can modify the copy as we parse it. */
843         scontext2 = kmalloc(scontext_len+1, gfp_flags);
844         if (!scontext2)
845                 return -ENOMEM;
846         memcpy(scontext2, scontext, scontext_len);
847         scontext2[scontext_len] = 0;
848
849         if (force) {
850                 /* Save another copy for storing in uninterpreted form */
851                 str = kstrdup(scontext2, gfp_flags);
852                 if (!str) {
853                         kfree(scontext2);
854                         return -ENOMEM;
855                 }
856         }
857
858         POLICY_RDLOCK;
859         rc = string_to_context_struct(&policydb, &sidtab,
860                                       scontext2, scontext_len,
861                                       &context, def_sid);
862         if (rc == -EINVAL && force) {
863                 context.str = str;
864                 context.len = scontext_len;
865                 str = NULL;
866         } else if (rc)
867                 goto out;
868         rc = sidtab_context_to_sid(&sidtab, &context, sid);
869         if (rc)
870                 context_destroy(&context);
871 out:
872         POLICY_RDUNLOCK;
873         kfree(scontext2);
874         kfree(str);
875         return rc;
876 }
877
878 /**
879  * security_context_to_sid - Obtain a SID for a given security context.
880  * @scontext: security context
881  * @scontext_len: length in bytes
882  * @sid: security identifier, SID
883  *
884  * Obtains a SID associated with the security context that
885  * has the string representation specified by @scontext.
886  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
887  * memory is available, or 0 on success.
888  */
889 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
890 {
891         return security_context_to_sid_core(scontext, scontext_len,
892                                             sid, SECSID_NULL, GFP_KERNEL, 0);
893 }
894
895 /**
896  * security_context_to_sid_default - Obtain a SID for a given security context,
897  * falling back to specified default if needed.
898  *
899  * @scontext: security context
900  * @scontext_len: length in bytes
901  * @sid: security identifier, SID
902  * @def_sid: default SID to assign on error
903  *
904  * Obtains a SID associated with the security context that
905  * has the string representation specified by @scontext.
906  * The default SID is passed to the MLS layer to be used to allow
907  * kernel labeling of the MLS field if the MLS field is not present
908  * (for upgrading to MLS without full relabel).
909  * Implicitly forces adding of the context even if it cannot be mapped yet.
910  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
911  * memory is available, or 0 on success.
912  */
913 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
914                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
915 {
916         return security_context_to_sid_core(scontext, scontext_len,
917                                             sid, def_sid, gfp_flags, 1);
918 }
919
920 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
921                                   u32 *sid)
922 {
923         return security_context_to_sid_core(scontext, scontext_len,
924                                             sid, SECSID_NULL, GFP_KERNEL, 1);
925 }
926
927 static int compute_sid_handle_invalid_context(
928         struct context *scontext,
929         struct context *tcontext,
930         u16 tclass,
931         struct context *newcontext)
932 {
933         char *s = NULL, *t = NULL, *n = NULL;
934         u32 slen, tlen, nlen;
935
936         if (context_struct_to_string(scontext, &s, &slen) < 0)
937                 goto out;
938         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
939                 goto out;
940         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
941                 goto out;
942         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
943                   "security_compute_sid:  invalid context %s"
944                   " for scontext=%s"
945                   " tcontext=%s"
946                   " tclass=%s",
947                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
948 out:
949         kfree(s);
950         kfree(t);
951         kfree(n);
952         if (!selinux_enforcing)
953                 return 0;
954         return -EACCES;
955 }
956
957 static int security_compute_sid(u32 ssid,
958                                 u32 tsid,
959                                 u16 tclass,
960                                 u32 specified,
961                                 u32 *out_sid)
962 {
963         struct context *scontext = NULL, *tcontext = NULL, newcontext;
964         struct role_trans *roletr = NULL;
965         struct avtab_key avkey;
966         struct avtab_datum *avdatum;
967         struct avtab_node *node;
968         int rc = 0;
969
970         if (!ss_initialized) {
971                 switch (tclass) {
972                 case SECCLASS_PROCESS:
973                         *out_sid = ssid;
974                         break;
975                 default:
976                         *out_sid = tsid;
977                         break;
978                 }
979                 goto out;
980         }
981
982         context_init(&newcontext);
983
984         POLICY_RDLOCK;
985
986         scontext = sidtab_search(&sidtab, ssid);
987         if (!scontext) {
988                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
989                        __func__, ssid);
990                 rc = -EINVAL;
991                 goto out_unlock;
992         }
993         tcontext = sidtab_search(&sidtab, tsid);
994         if (!tcontext) {
995                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
996                        __func__, tsid);
997                 rc = -EINVAL;
998                 goto out_unlock;
999         }
1000
1001         /* Set the user identity. */
1002         switch (specified) {
1003         case AVTAB_TRANSITION:
1004         case AVTAB_CHANGE:
1005                 /* Use the process user identity. */
1006                 newcontext.user = scontext->user;
1007                 break;
1008         case AVTAB_MEMBER:
1009                 /* Use the related object owner. */
1010                 newcontext.user = tcontext->user;
1011                 break;
1012         }
1013
1014         /* Set the role and type to default values. */
1015         switch (tclass) {
1016         case SECCLASS_PROCESS:
1017                 /* Use the current role and type of process. */
1018                 newcontext.role = scontext->role;
1019                 newcontext.type = scontext->type;
1020                 break;
1021         default:
1022                 /* Use the well-defined object role. */
1023                 newcontext.role = OBJECT_R_VAL;
1024                 /* Use the type of the related object. */
1025                 newcontext.type = tcontext->type;
1026         }
1027
1028         /* Look for a type transition/member/change rule. */
1029         avkey.source_type = scontext->type;
1030         avkey.target_type = tcontext->type;
1031         avkey.target_class = tclass;
1032         avkey.specified = specified;
1033         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1034
1035         /* If no permanent rule, also check for enabled conditional rules */
1036         if (!avdatum) {
1037                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1038                 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
1039                         if (node->key.specified & AVTAB_ENABLED) {
1040                                 avdatum = &node->datum;
1041                                 break;
1042                         }
1043                 }
1044         }
1045
1046         if (avdatum) {
1047                 /* Use the type from the type transition/member/change rule. */
1048                 newcontext.type = avdatum->data;
1049         }
1050
1051         /* Check for class-specific changes. */
1052         switch (tclass) {
1053         case SECCLASS_PROCESS:
1054                 if (specified & AVTAB_TRANSITION) {
1055                         /* Look for a role transition rule. */
1056                         for (roletr = policydb.role_tr; roletr;
1057                              roletr = roletr->next) {
1058                                 if (roletr->role == scontext->role &&
1059                                     roletr->type == tcontext->type) {
1060                                         /* Use the role transition rule. */
1061                                         newcontext.role = roletr->new_role;
1062                                         break;
1063                                 }
1064                         }
1065                 }
1066                 break;
1067         default:
1068                 break;
1069         }
1070
1071         /* Set the MLS attributes.
1072            This is done last because it may allocate memory. */
1073         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1074         if (rc)
1075                 goto out_unlock;
1076
1077         /* Check the validity of the context. */
1078         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1079                 rc = compute_sid_handle_invalid_context(scontext,
1080                                                         tcontext,
1081                                                         tclass,
1082                                                         &newcontext);
1083                 if (rc)
1084                         goto out_unlock;
1085         }
1086         /* Obtain the sid for the context. */
1087         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1088 out_unlock:
1089         POLICY_RDUNLOCK;
1090         context_destroy(&newcontext);
1091 out:
1092         return rc;
1093 }
1094
1095 /**
1096  * security_transition_sid - Compute the SID for a new subject/object.
1097  * @ssid: source security identifier
1098  * @tsid: target security identifier
1099  * @tclass: target security class
1100  * @out_sid: security identifier for new subject/object
1101  *
1102  * Compute a SID to use for labeling a new subject or object in the
1103  * class @tclass based on a SID pair (@ssid, @tsid).
1104  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1105  * if insufficient memory is available, or %0 if the new SID was
1106  * computed successfully.
1107  */
1108 int security_transition_sid(u32 ssid,
1109                             u32 tsid,
1110                             u16 tclass,
1111                             u32 *out_sid)
1112 {
1113         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1114 }
1115
1116 /**
1117  * security_member_sid - Compute the SID for member selection.
1118  * @ssid: source security identifier
1119  * @tsid: target security identifier
1120  * @tclass: target security class
1121  * @out_sid: security identifier for selected member
1122  *
1123  * Compute a SID to use when selecting a member of a polyinstantiated
1124  * object of class @tclass based on a SID pair (@ssid, @tsid).
1125  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1126  * if insufficient memory is available, or %0 if the SID was
1127  * computed successfully.
1128  */
1129 int security_member_sid(u32 ssid,
1130                         u32 tsid,
1131                         u16 tclass,
1132                         u32 *out_sid)
1133 {
1134         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1135 }
1136
1137 /**
1138  * security_change_sid - Compute the SID for object relabeling.
1139  * @ssid: source security identifier
1140  * @tsid: target security identifier
1141  * @tclass: target security class
1142  * @out_sid: security identifier for selected member
1143  *
1144  * Compute a SID to use for relabeling an object of class @tclass
1145  * based on a SID pair (@ssid, @tsid).
1146  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1147  * if insufficient memory is available, or %0 if the SID was
1148  * computed successfully.
1149  */
1150 int security_change_sid(u32 ssid,
1151                         u32 tsid,
1152                         u16 tclass,
1153                         u32 *out_sid)
1154 {
1155         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1156 }
1157
1158 /*
1159  * Verify that each kernel class that is defined in the
1160  * policy is correct
1161  */
1162 static int validate_classes(struct policydb *p)
1163 {
1164         int i, j;
1165         struct class_datum *cladatum;
1166         struct perm_datum *perdatum;
1167         u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1168         u16 class_val;
1169         const struct selinux_class_perm *kdefs = &selinux_class_perm;
1170         const char *def_class, *def_perm, *pol_class;
1171         struct symtab *perms;
1172
1173         if (p->allow_unknown) {
1174                 u32 num_classes = kdefs->cts_len;
1175                 p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1176                 if (!p->undefined_perms)
1177                         return -ENOMEM;
1178         }
1179
1180         for (i = 1; i < kdefs->cts_len; i++) {
1181                 def_class = kdefs->class_to_string[i];
1182                 if (!def_class)
1183                         continue;
1184                 if (i > p->p_classes.nprim) {
1185                         printk(KERN_INFO
1186                                "SELinux:  class %s not defined in policy\n",
1187                                def_class);
1188                         if (p->reject_unknown)
1189                                 return -EINVAL;
1190                         if (p->allow_unknown)
1191                                 p->undefined_perms[i-1] = ~0U;
1192                         continue;
1193                 }
1194                 pol_class = p->p_class_val_to_name[i-1];
1195                 if (strcmp(pol_class, def_class)) {
1196                         printk(KERN_ERR
1197                                "SELinux:  class %d is incorrect, found %s but should be %s\n",
1198                                i, pol_class, def_class);
1199                         return -EINVAL;
1200                 }
1201         }
1202         for (i = 0; i < kdefs->av_pts_len; i++) {
1203                 class_val = kdefs->av_perm_to_string[i].tclass;
1204                 perm_val = kdefs->av_perm_to_string[i].value;
1205                 def_perm = kdefs->av_perm_to_string[i].name;
1206                 if (class_val > p->p_classes.nprim)
1207                         continue;
1208                 pol_class = p->p_class_val_to_name[class_val-1];
1209                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1210                 BUG_ON(!cladatum);
1211                 perms = &cladatum->permissions;
1212                 nprim = 1 << (perms->nprim - 1);
1213                 if (perm_val > nprim) {
1214                         printk(KERN_INFO
1215                                "SELinux:  permission %s in class %s not defined in policy\n",
1216                                def_perm, pol_class);
1217                         if (p->reject_unknown)
1218                                 return -EINVAL;
1219                         if (p->allow_unknown)
1220                                 p->undefined_perms[class_val-1] |= perm_val;
1221                         continue;
1222                 }
1223                 perdatum = hashtab_search(perms->table, def_perm);
1224                 if (perdatum == NULL) {
1225                         printk(KERN_ERR
1226                                "SELinux:  permission %s in class %s not found in policy, bad policy\n",
1227                                def_perm, pol_class);
1228                         return -EINVAL;
1229                 }
1230                 pol_val = 1 << (perdatum->value - 1);
1231                 if (pol_val != perm_val) {
1232                         printk(KERN_ERR
1233                                "SELinux:  permission %s in class %s has incorrect value\n",
1234                                def_perm, pol_class);
1235                         return -EINVAL;
1236                 }
1237         }
1238         for (i = 0; i < kdefs->av_inherit_len; i++) {
1239                 class_val = kdefs->av_inherit[i].tclass;
1240                 if (class_val > p->p_classes.nprim)
1241                         continue;
1242                 pol_class = p->p_class_val_to_name[class_val-1];
1243                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1244                 BUG_ON(!cladatum);
1245                 if (!cladatum->comdatum) {
1246                         printk(KERN_ERR
1247                                "SELinux:  class %s should have an inherits clause but does not\n",
1248                                pol_class);
1249                         return -EINVAL;
1250                 }
1251                 tmp = kdefs->av_inherit[i].common_base;
1252                 common_pts_len = 0;
1253                 while (!(tmp & 0x01)) {
1254                         common_pts_len++;
1255                         tmp >>= 1;
1256                 }
1257                 perms = &cladatum->comdatum->permissions;
1258                 for (j = 0; j < common_pts_len; j++) {
1259                         def_perm = kdefs->av_inherit[i].common_pts[j];
1260                         if (j >= perms->nprim) {
1261                                 printk(KERN_INFO
1262                                        "SELinux:  permission %s in class %s not defined in policy\n",
1263                                        def_perm, pol_class);
1264                                 if (p->reject_unknown)
1265                                         return -EINVAL;
1266                                 if (p->allow_unknown)
1267                                         p->undefined_perms[class_val-1] |= (1 << j);
1268                                 continue;
1269                         }
1270                         perdatum = hashtab_search(perms->table, def_perm);
1271                         if (perdatum == NULL) {
1272                                 printk(KERN_ERR
1273                                        "SELinux:  permission %s in class %s not found in policy, bad policy\n",
1274                                        def_perm, pol_class);
1275                                 return -EINVAL;
1276                         }
1277                         if (perdatum->value != j + 1) {
1278                                 printk(KERN_ERR
1279                                        "SELinux:  permission %s in class %s has incorrect value\n",
1280                                        def_perm, pol_class);
1281                                 return -EINVAL;
1282                         }
1283                 }
1284         }
1285         return 0;
1286 }
1287
1288 /* Clone the SID into the new SID table. */
1289 static int clone_sid(u32 sid,
1290                      struct context *context,
1291                      void *arg)
1292 {
1293         struct sidtab *s = arg;
1294
1295         return sidtab_insert(s, sid, context);
1296 }
1297
1298 static inline int convert_context_handle_invalid_context(struct context *context)
1299 {
1300         int rc = 0;
1301
1302         if (selinux_enforcing) {
1303                 rc = -EINVAL;
1304         } else {
1305                 char *s;
1306                 u32 len;
1307
1308                 if (!context_struct_to_string(context, &s, &len)) {
1309                         printk(KERN_WARNING
1310                        "SELinux:  Context %s would be invalid if enforcing\n",
1311                                s);
1312                         kfree(s);
1313                 }
1314         }
1315         return rc;
1316 }
1317
1318 struct convert_context_args {
1319         struct policydb *oldp;
1320         struct policydb *newp;
1321 };
1322
1323 /*
1324  * Convert the values in the security context
1325  * structure `c' from the values specified
1326  * in the policy `p->oldp' to the values specified
1327  * in the policy `p->newp'.  Verify that the
1328  * context is valid under the new policy.
1329  */
1330 static int convert_context(u32 key,
1331                            struct context *c,
1332                            void *p)
1333 {
1334         struct convert_context_args *args;
1335         struct context oldc;
1336         struct role_datum *role;
1337         struct type_datum *typdatum;
1338         struct user_datum *usrdatum;
1339         char *s;
1340         u32 len;
1341         int rc;
1342
1343         args = p;
1344
1345         if (c->str) {
1346                 struct context ctx;
1347                 s = kstrdup(c->str, GFP_KERNEL);
1348                 if (!s) {
1349                         rc = -ENOMEM;
1350                         goto out;
1351                 }
1352                 rc = string_to_context_struct(args->newp, NULL, s,
1353                                               c->len, &ctx, SECSID_NULL);
1354                 kfree(s);
1355                 if (!rc) {
1356                         printk(KERN_INFO
1357                        "SELinux:  Context %s became valid (mapped).\n",
1358                                c->str);
1359                         /* Replace string with mapped representation. */
1360                         kfree(c->str);
1361                         memcpy(c, &ctx, sizeof(*c));
1362                         goto out;
1363                 } else if (rc == -EINVAL) {
1364                         /* Retain string representation for later mapping. */
1365                         rc = 0;
1366                         goto out;
1367                 } else {
1368                         /* Other error condition, e.g. ENOMEM. */
1369                         printk(KERN_ERR
1370                        "SELinux:   Unable to map context %s, rc = %d.\n",
1371                                c->str, -rc);
1372                         goto out;
1373                 }
1374         }
1375
1376         rc = context_cpy(&oldc, c);
1377         if (rc)
1378                 goto out;
1379
1380         rc = -EINVAL;
1381
1382         /* Convert the user. */
1383         usrdatum = hashtab_search(args->newp->p_users.table,
1384                                   args->oldp->p_user_val_to_name[c->user - 1]);
1385         if (!usrdatum)
1386                 goto bad;
1387         c->user = usrdatum->value;
1388
1389         /* Convert the role. */
1390         role = hashtab_search(args->newp->p_roles.table,
1391                               args->oldp->p_role_val_to_name[c->role - 1]);
1392         if (!role)
1393                 goto bad;
1394         c->role = role->value;
1395
1396         /* Convert the type. */
1397         typdatum = hashtab_search(args->newp->p_types.table,
1398                                   args->oldp->p_type_val_to_name[c->type - 1]);
1399         if (!typdatum)
1400                 goto bad;
1401         c->type = typdatum->value;
1402
1403         rc = mls_convert_context(args->oldp, args->newp, c);
1404         if (rc)
1405                 goto bad;
1406
1407         /* Check the validity of the new context. */
1408         if (!policydb_context_isvalid(args->newp, c)) {
1409                 rc = convert_context_handle_invalid_context(&oldc);
1410                 if (rc)
1411                         goto bad;
1412         }
1413
1414         context_destroy(&oldc);
1415         rc = 0;
1416 out:
1417         return rc;
1418 bad:
1419         /* Map old representation to string and save it. */
1420         if (context_struct_to_string(&oldc, &s, &len))
1421                 return -ENOMEM;
1422         context_destroy(&oldc);
1423         context_destroy(c);
1424         c->str = s;
1425         c->len = len;
1426         printk(KERN_INFO
1427                "SELinux:  Context %s became invalid (unmapped).\n",
1428                c->str);
1429         rc = 0;
1430         goto out;
1431 }
1432
1433 static void security_load_policycaps(void)
1434 {
1435         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1436                                                   POLICYDB_CAPABILITY_NETPEER);
1437         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1438                                                   POLICYDB_CAPABILITY_OPENPERM);
1439 }
1440
1441 extern void selinux_complete_init(void);
1442 static int security_preserve_bools(struct policydb *p);
1443
1444 /**
1445  * security_load_policy - Load a security policy configuration.
1446  * @data: binary policy data
1447  * @len: length of data in bytes
1448  *
1449  * Load a new set of security policy configuration data,
1450  * validate it and convert the SID table as necessary.
1451  * This function will flush the access vector cache after
1452  * loading the new policy.
1453  */
1454 int security_load_policy(void *data, size_t len)
1455 {
1456         struct policydb oldpolicydb, newpolicydb;
1457         struct sidtab oldsidtab, newsidtab;
1458         struct convert_context_args args;
1459         u32 seqno;
1460         int rc = 0;
1461         struct policy_file file = { data, len }, *fp = &file;
1462
1463         LOAD_LOCK;
1464
1465         if (!ss_initialized) {
1466                 avtab_cache_init();
1467                 if (policydb_read(&policydb, fp)) {
1468                         LOAD_UNLOCK;
1469                         avtab_cache_destroy();
1470                         return -EINVAL;
1471                 }
1472                 if (policydb_load_isids(&policydb, &sidtab)) {
1473                         LOAD_UNLOCK;
1474                         policydb_destroy(&policydb);
1475                         avtab_cache_destroy();
1476                         return -EINVAL;
1477                 }
1478                 /* Verify that the kernel defined classes are correct. */
1479                 if (validate_classes(&policydb)) {
1480                         printk(KERN_ERR
1481                                "SELinux:  the definition of a class is incorrect\n");
1482                         LOAD_UNLOCK;
1483                         sidtab_destroy(&sidtab);
1484                         policydb_destroy(&policydb);
1485                         avtab_cache_destroy();
1486                         return -EINVAL;
1487                 }
1488                 security_load_policycaps();
1489                 policydb_loaded_version = policydb.policyvers;
1490                 ss_initialized = 1;
1491                 seqno = ++latest_granting;
1492                 LOAD_UNLOCK;
1493                 selinux_complete_init();
1494                 avc_ss_reset(seqno);
1495                 selnl_notify_policyload(seqno);
1496                 selinux_netlbl_cache_invalidate();
1497                 selinux_xfrm_notify_policyload();
1498                 return 0;
1499         }
1500
1501 #if 0
1502         sidtab_hash_eval(&sidtab, "sids");
1503 #endif
1504
1505         if (policydb_read(&newpolicydb, fp)) {
1506                 LOAD_UNLOCK;
1507                 return -EINVAL;
1508         }
1509
1510         if (sidtab_init(&newsidtab)) {
1511                 LOAD_UNLOCK;
1512                 policydb_destroy(&newpolicydb);
1513                 return -ENOMEM;
1514         }
1515
1516         /* Verify that the kernel defined classes are correct. */
1517         if (validate_classes(&newpolicydb)) {
1518                 printk(KERN_ERR
1519                        "SELinux:  the definition of a class is incorrect\n");
1520                 rc = -EINVAL;
1521                 goto err;
1522         }
1523
1524         rc = security_preserve_bools(&newpolicydb);
1525         if (rc) {
1526                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1527                 goto err;
1528         }
1529
1530         /* Clone the SID table. */
1531         sidtab_shutdown(&sidtab);
1532         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1533                 rc = -ENOMEM;
1534                 goto err;
1535         }
1536
1537         /*
1538          * Convert the internal representations of contexts
1539          * in the new SID table.
1540          */
1541         args.oldp = &policydb;
1542         args.newp = &newpolicydb;
1543         rc = sidtab_map(&newsidtab, convert_context, &args);
1544         if (rc)
1545                 goto err;
1546
1547         /* Save the old policydb and SID table to free later. */
1548         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1549         sidtab_set(&oldsidtab, &sidtab);
1550
1551         /* Install the new policydb and SID table. */
1552         POLICY_WRLOCK;
1553         memcpy(&policydb, &newpolicydb, sizeof policydb);
1554         sidtab_set(&sidtab, &newsidtab);
1555         security_load_policycaps();
1556         seqno = ++latest_granting;
1557         policydb_loaded_version = policydb.policyvers;
1558         POLICY_WRUNLOCK;
1559         LOAD_UNLOCK;
1560
1561         /* Free the old policydb and SID table. */
1562         policydb_destroy(&oldpolicydb);
1563         sidtab_destroy(&oldsidtab);
1564
1565         avc_ss_reset(seqno);
1566         selnl_notify_policyload(seqno);
1567         selinux_netlbl_cache_invalidate();
1568         selinux_xfrm_notify_policyload();
1569
1570         return 0;
1571
1572 err:
1573         LOAD_UNLOCK;
1574         sidtab_destroy(&newsidtab);
1575         policydb_destroy(&newpolicydb);
1576         return rc;
1577
1578 }
1579
1580 /**
1581  * security_port_sid - Obtain the SID for a port.
1582  * @protocol: protocol number
1583  * @port: port number
1584  * @out_sid: security identifier
1585  */
1586 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1587 {
1588         struct ocontext *c;
1589         int rc = 0;
1590
1591         POLICY_RDLOCK;
1592
1593         c = policydb.ocontexts[OCON_PORT];
1594         while (c) {
1595                 if (c->u.port.protocol == protocol &&
1596                     c->u.port.low_port <= port &&
1597                     c->u.port.high_port >= port)
1598                         break;
1599                 c = c->next;
1600         }
1601
1602         if (c) {
1603                 if (!c->sid[0]) {
1604                         rc = sidtab_context_to_sid(&sidtab,
1605                                                    &c->context[0],
1606                                                    &c->sid[0]);
1607                         if (rc)
1608                                 goto out;
1609                 }
1610                 *out_sid = c->sid[0];
1611         } else {
1612                 *out_sid = SECINITSID_PORT;
1613         }
1614
1615 out:
1616         POLICY_RDUNLOCK;
1617         return rc;
1618 }
1619
1620 /**
1621  * security_netif_sid - Obtain the SID for a network interface.
1622  * @name: interface name
1623  * @if_sid: interface SID
1624  */
1625 int security_netif_sid(char *name, u32 *if_sid)
1626 {
1627         int rc = 0;
1628         struct ocontext *c;
1629
1630         POLICY_RDLOCK;
1631
1632         c = policydb.ocontexts[OCON_NETIF];
1633         while (c) {
1634                 if (strcmp(name, c->u.name) == 0)
1635                         break;
1636                 c = c->next;
1637         }
1638
1639         if (c) {
1640                 if (!c->sid[0] || !c->sid[1]) {
1641                         rc = sidtab_context_to_sid(&sidtab,
1642                                                   &c->context[0],
1643                                                   &c->sid[0]);
1644                         if (rc)
1645                                 goto out;
1646                         rc = sidtab_context_to_sid(&sidtab,
1647                                                    &c->context[1],
1648                                                    &c->sid[1]);
1649                         if (rc)
1650                                 goto out;
1651                 }
1652                 *if_sid = c->sid[0];
1653         } else
1654                 *if_sid = SECINITSID_NETIF;
1655
1656 out:
1657         POLICY_RDUNLOCK;
1658         return rc;
1659 }
1660
1661 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1662 {
1663         int i, fail = 0;
1664
1665         for (i = 0; i < 4; i++)
1666                 if (addr[i] != (input[i] & mask[i])) {
1667                         fail = 1;
1668                         break;
1669                 }
1670
1671         return !fail;
1672 }
1673
1674 /**
1675  * security_node_sid - Obtain the SID for a node (host).
1676  * @domain: communication domain aka address family
1677  * @addrp: address
1678  * @addrlen: address length in bytes
1679  * @out_sid: security identifier
1680  */
1681 int security_node_sid(u16 domain,
1682                       void *addrp,
1683                       u32 addrlen,
1684                       u32 *out_sid)
1685 {
1686         int rc = 0;
1687         struct ocontext *c;
1688
1689         POLICY_RDLOCK;
1690
1691         switch (domain) {
1692         case AF_INET: {
1693                 u32 addr;
1694
1695                 if (addrlen != sizeof(u32)) {
1696                         rc = -EINVAL;
1697                         goto out;
1698                 }
1699
1700                 addr = *((u32 *)addrp);
1701
1702                 c = policydb.ocontexts[OCON_NODE];
1703                 while (c) {
1704                         if (c->u.node.addr == (addr & c->u.node.mask))
1705                                 break;
1706                         c = c->next;
1707                 }
1708                 break;
1709         }
1710
1711         case AF_INET6:
1712                 if (addrlen != sizeof(u64) * 2) {
1713                         rc = -EINVAL;
1714                         goto out;
1715                 }
1716                 c = policydb.ocontexts[OCON_NODE6];
1717                 while (c) {
1718                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1719                                                 c->u.node6.mask))
1720                                 break;
1721                         c = c->next;
1722                 }
1723                 break;
1724
1725         default:
1726                 *out_sid = SECINITSID_NODE;
1727                 goto out;
1728         }
1729
1730         if (c) {
1731                 if (!c->sid[0]) {
1732                         rc = sidtab_context_to_sid(&sidtab,
1733                                                    &c->context[0],
1734                                                    &c->sid[0]);
1735                         if (rc)
1736                                 goto out;
1737                 }
1738                 *out_sid = c->sid[0];
1739         } else {
1740                 *out_sid = SECINITSID_NODE;
1741         }
1742
1743 out:
1744         POLICY_RDUNLOCK;
1745         return rc;
1746 }
1747
1748 #define SIDS_NEL 25
1749
1750 /**
1751  * security_get_user_sids - Obtain reachable SIDs for a user.
1752  * @fromsid: starting SID
1753  * @username: username
1754  * @sids: array of reachable SIDs for user
1755  * @nel: number of elements in @sids
1756  *
1757  * Generate the set of SIDs for legal security contexts
1758  * for a given user that can be reached by @fromsid.
1759  * Set *@sids to point to a dynamically allocated
1760  * array containing the set of SIDs.  Set *@nel to the
1761  * number of elements in the array.
1762  */
1763
1764 int security_get_user_sids(u32 fromsid,
1765                            char *username,
1766                            u32 **sids,
1767                            u32 *nel)
1768 {
1769         struct context *fromcon, usercon;
1770         u32 *mysids = NULL, *mysids2, sid;
1771         u32 mynel = 0, maxnel = SIDS_NEL;
1772         struct user_datum *user;
1773         struct role_datum *role;
1774         struct ebitmap_node *rnode, *tnode;
1775         int rc = 0, i, j;
1776
1777         *sids = NULL;
1778         *nel = 0;
1779
1780         if (!ss_initialized)
1781                 goto out;
1782
1783         POLICY_RDLOCK;
1784
1785         context_init(&usercon);
1786
1787         fromcon = sidtab_search(&sidtab, fromsid);
1788         if (!fromcon) {
1789                 rc = -EINVAL;
1790                 goto out_unlock;
1791         }
1792
1793         user = hashtab_search(policydb.p_users.table, username);
1794         if (!user) {
1795                 rc = -EINVAL;
1796                 goto out_unlock;
1797         }
1798         usercon.user = user->value;
1799
1800         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1801         if (!mysids) {
1802                 rc = -ENOMEM;
1803                 goto out_unlock;
1804         }
1805
1806         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1807                 role = policydb.role_val_to_struct[i];
1808                 usercon.role = i+1;
1809                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1810                         usercon.type = j+1;
1811
1812                         if (mls_setup_user_range(fromcon, user, &usercon))
1813                                 continue;
1814
1815                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1816                         if (rc)
1817                                 goto out_unlock;
1818                         if (mynel < maxnel) {
1819                                 mysids[mynel++] = sid;
1820                         } else {
1821                                 maxnel += SIDS_NEL;
1822                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1823                                 if (!mysids2) {
1824                                         rc = -ENOMEM;
1825                                         goto out_unlock;
1826                                 }
1827                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1828                                 kfree(mysids);
1829                                 mysids = mysids2;
1830                                 mysids[mynel++] = sid;
1831                         }
1832                 }
1833         }
1834
1835 out_unlock:
1836         POLICY_RDUNLOCK;
1837         if (rc || !mynel) {
1838                 kfree(mysids);
1839                 goto out;
1840         }
1841
1842         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1843         if (!mysids2) {
1844                 rc = -ENOMEM;
1845                 kfree(mysids);
1846                 goto out;
1847         }
1848         for (i = 0, j = 0; i < mynel; i++) {
1849                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
1850                                           SECCLASS_PROCESS,
1851                                           PROCESS__TRANSITION, AVC_STRICT,
1852                                           NULL);
1853                 if (!rc)
1854                         mysids2[j++] = mysids[i];
1855                 cond_resched();
1856         }
1857         rc = 0;
1858         kfree(mysids);
1859         *sids = mysids2;
1860         *nel = j;
1861 out:
1862         return rc;
1863 }
1864
1865 /**
1866  * security_genfs_sid - Obtain a SID for a file in a filesystem
1867  * @fstype: filesystem type
1868  * @path: path from root of mount
1869  * @sclass: file security class
1870  * @sid: SID for path
1871  *
1872  * Obtain a SID to use for a file in a filesystem that
1873  * cannot support xattr or use a fixed labeling behavior like
1874  * transition SIDs or task SIDs.
1875  */
1876 int security_genfs_sid(const char *fstype,
1877                        char *path,
1878                        u16 sclass,
1879                        u32 *sid)
1880 {
1881         int len;
1882         struct genfs *genfs;
1883         struct ocontext *c;
1884         int rc = 0, cmp = 0;
1885
1886         while (path[0] == '/' && path[1] == '/')
1887                 path++;
1888
1889         POLICY_RDLOCK;
1890
1891         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1892                 cmp = strcmp(fstype, genfs->fstype);
1893                 if (cmp <= 0)
1894                         break;
1895         }
1896
1897         if (!genfs || cmp) {
1898                 *sid = SECINITSID_UNLABELED;
1899                 rc = -ENOENT;
1900                 goto out;
1901         }
1902
1903         for (c = genfs->head; c; c = c->next) {
1904                 len = strlen(c->u.name);
1905                 if ((!c->v.sclass || sclass == c->v.sclass) &&
1906                     (strncmp(c->u.name, path, len) == 0))
1907                         break;
1908         }
1909
1910         if (!c) {
1911                 *sid = SECINITSID_UNLABELED;
1912                 rc = -ENOENT;
1913                 goto out;
1914         }
1915
1916         if (!c->sid[0]) {
1917                 rc = sidtab_context_to_sid(&sidtab,
1918                                            &c->context[0],
1919                                            &c->sid[0]);
1920                 if (rc)
1921                         goto out;
1922         }
1923
1924         *sid = c->sid[0];
1925 out:
1926         POLICY_RDUNLOCK;
1927         return rc;
1928 }
1929
1930 /**
1931  * security_fs_use - Determine how to handle labeling for a filesystem.
1932  * @fstype: filesystem type
1933  * @behavior: labeling behavior
1934  * @sid: SID for filesystem (superblock)
1935  */
1936 int security_fs_use(
1937         const char *fstype,
1938         unsigned int *behavior,
1939         u32 *sid)
1940 {
1941         int rc = 0;
1942         struct ocontext *c;
1943
1944         POLICY_RDLOCK;
1945
1946         c = policydb.ocontexts[OCON_FSUSE];
1947         while (c) {
1948                 if (strcmp(fstype, c->u.name) == 0)
1949                         break;
1950                 c = c->next;
1951         }
1952
1953         if (c) {
1954                 *behavior = c->v.behavior;
1955                 if (!c->sid[0]) {
1956                         rc = sidtab_context_to_sid(&sidtab,
1957                                                    &c->context[0],
1958                                                    &c->sid[0]);
1959                         if (rc)
1960                                 goto out;
1961                 }
1962                 *sid = c->sid[0];
1963         } else {
1964                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1965                 if (rc) {
1966                         *behavior = SECURITY_FS_USE_NONE;
1967                         rc = 0;
1968                 } else {
1969                         *behavior = SECURITY_FS_USE_GENFS;
1970                 }
1971         }
1972
1973 out:
1974         POLICY_RDUNLOCK;
1975         return rc;
1976 }
1977
1978 int security_get_bools(int *len, char ***names, int **values)
1979 {
1980         int i, rc = -ENOMEM;
1981
1982         POLICY_RDLOCK;
1983         *names = NULL;
1984         *values = NULL;
1985
1986         *len = policydb.p_bools.nprim;
1987         if (!*len) {
1988                 rc = 0;
1989                 goto out;
1990         }
1991
1992        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
1993         if (!*names)
1994                 goto err;
1995
1996        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1997         if (!*values)
1998                 goto err;
1999
2000         for (i = 0; i < *len; i++) {
2001                 size_t name_len;
2002                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2003                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2004                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2005                 if (!(*names)[i])
2006                         goto err;
2007                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2008                 (*names)[i][name_len - 1] = 0;
2009         }
2010         rc = 0;
2011 out:
2012         POLICY_RDUNLOCK;
2013         return rc;
2014 err:
2015         if (*names) {
2016                 for (i = 0; i < *len; i++)
2017                         kfree((*names)[i]);
2018         }
2019         kfree(*values);
2020         goto out;
2021 }
2022
2023
2024 int security_set_bools(int len, int *values)
2025 {
2026         int i, rc = 0;
2027         int lenp, seqno = 0;
2028         struct cond_node *cur;
2029
2030         POLICY_WRLOCK;
2031
2032         lenp = policydb.p_bools.nprim;
2033         if (len != lenp) {
2034                 rc = -EFAULT;
2035                 goto out;
2036         }
2037
2038         for (i = 0; i < len; i++) {
2039                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2040                         audit_log(current->audit_context, GFP_ATOMIC,
2041                                 AUDIT_MAC_CONFIG_CHANGE,
2042                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2043                                 policydb.p_bool_val_to_name[i],
2044                                 !!values[i],
2045                                 policydb.bool_val_to_struct[i]->state,
2046                                 audit_get_loginuid(current),
2047                                 audit_get_sessionid(current));
2048                 }
2049                 if (values[i])
2050                         policydb.bool_val_to_struct[i]->state = 1;
2051                 else
2052                         policydb.bool_val_to_struct[i]->state = 0;
2053         }
2054
2055         for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
2056                 rc = evaluate_cond_node(&policydb, cur);
2057                 if (rc)
2058                         goto out;
2059         }
2060
2061         seqno = ++latest_granting;
2062
2063 out:
2064         POLICY_WRUNLOCK;
2065         if (!rc) {
2066                 avc_ss_reset(seqno);
2067                 selnl_notify_policyload(seqno);
2068                 selinux_xfrm_notify_policyload();
2069         }
2070         return rc;
2071 }
2072
2073 int security_get_bool_value(int bool)
2074 {
2075         int rc = 0;
2076         int len;
2077
2078         POLICY_RDLOCK;
2079
2080         len = policydb.p_bools.nprim;
2081         if (bool >= len) {
2082                 rc = -EFAULT;
2083                 goto out;
2084         }
2085
2086         rc = policydb.bool_val_to_struct[bool]->state;
2087 out:
2088         POLICY_RDUNLOCK;
2089         return rc;
2090 }
2091
2092 static int security_preserve_bools(struct policydb *p)
2093 {
2094         int rc, nbools = 0, *bvalues = NULL, i;
2095         char **bnames = NULL;
2096         struct cond_bool_datum *booldatum;
2097         struct cond_node *cur;
2098
2099         rc = security_get_bools(&nbools, &bnames, &bvalues);
2100         if (rc)
2101                 goto out;
2102         for (i = 0; i < nbools; i++) {
2103                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2104                 if (booldatum)
2105                         booldatum->state = bvalues[i];
2106         }
2107         for (cur = p->cond_list; cur != NULL; cur = cur->next) {
2108                 rc = evaluate_cond_node(p, cur);
2109                 if (rc)
2110                         goto out;
2111         }
2112
2113 out:
2114         if (bnames) {
2115                 for (i = 0; i < nbools; i++)
2116                         kfree(bnames[i]);
2117         }
2118         kfree(bnames);
2119         kfree(bvalues);
2120         return rc;
2121 }
2122
2123 /*
2124  * security_sid_mls_copy() - computes a new sid based on the given
2125  * sid and the mls portion of mls_sid.
2126  */
2127 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2128 {
2129         struct context *context1;
2130         struct context *context2;
2131         struct context newcon;
2132         char *s;
2133         u32 len;
2134         int rc = 0;
2135
2136         if (!ss_initialized || !selinux_mls_enabled) {
2137                 *new_sid = sid;
2138                 goto out;
2139         }
2140
2141         context_init(&newcon);
2142
2143         POLICY_RDLOCK;
2144         context1 = sidtab_search(&sidtab, sid);
2145         if (!context1) {
2146                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2147                         __func__, sid);
2148                 rc = -EINVAL;
2149                 goto out_unlock;
2150         }
2151
2152         context2 = sidtab_search(&sidtab, mls_sid);
2153         if (!context2) {
2154                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2155                         __func__, mls_sid);
2156                 rc = -EINVAL;
2157                 goto out_unlock;
2158         }
2159
2160         newcon.user = context1->user;
2161         newcon.role = context1->role;
2162         newcon.type = context1->type;
2163         rc = mls_context_cpy(&newcon, context2);
2164         if (rc)
2165                 goto out_unlock;
2166
2167         /* Check the validity of the new context. */
2168         if (!policydb_context_isvalid(&policydb, &newcon)) {
2169                 rc = convert_context_handle_invalid_context(&newcon);
2170                 if (rc)
2171                         goto bad;
2172         }
2173
2174         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2175         goto out_unlock;
2176
2177 bad:
2178         if (!context_struct_to_string(&newcon, &s, &len)) {
2179                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2180                           "security_sid_mls_copy: invalid context %s", s);
2181                 kfree(s);
2182         }
2183
2184 out_unlock:
2185         POLICY_RDUNLOCK;
2186         context_destroy(&newcon);
2187 out:
2188         return rc;
2189 }
2190
2191 /**
2192  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2193  * @nlbl_sid: NetLabel SID
2194  * @nlbl_type: NetLabel labeling protocol type
2195  * @xfrm_sid: XFRM SID
2196  *
2197  * Description:
2198  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2199  * resolved into a single SID it is returned via @peer_sid and the function
2200  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2201  * returns a negative value.  A table summarizing the behavior is below:
2202  *
2203  *                                 | function return |      @sid
2204  *   ------------------------------+-----------------+-----------------
2205  *   no peer labels                |        0        |    SECSID_NULL
2206  *   single peer label             |        0        |    <peer_label>
2207  *   multiple, consistent labels   |        0        |    <peer_label>
2208  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2209  *
2210  */
2211 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2212                                  u32 xfrm_sid,
2213                                  u32 *peer_sid)
2214 {
2215         int rc;
2216         struct context *nlbl_ctx;
2217         struct context *xfrm_ctx;
2218
2219         /* handle the common (which also happens to be the set of easy) cases
2220          * right away, these two if statements catch everything involving a
2221          * single or absent peer SID/label */
2222         if (xfrm_sid == SECSID_NULL) {
2223                 *peer_sid = nlbl_sid;
2224                 return 0;
2225         }
2226         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2227          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2228          * is present */
2229         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2230                 *peer_sid = xfrm_sid;
2231                 return 0;
2232         }
2233
2234         /* we don't need to check ss_initialized here since the only way both
2235          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2236          * security server was initialized and ss_initialized was true */
2237         if (!selinux_mls_enabled) {
2238                 *peer_sid = SECSID_NULL;
2239                 return 0;
2240         }
2241
2242         POLICY_RDLOCK;
2243
2244         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2245         if (!nlbl_ctx) {
2246                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2247                        __func__, nlbl_sid);
2248                 rc = -EINVAL;
2249                 goto out_slowpath;
2250         }
2251         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2252         if (!xfrm_ctx) {
2253                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2254                        __func__, xfrm_sid);
2255                 rc = -EINVAL;
2256                 goto out_slowpath;
2257         }
2258         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2259
2260 out_slowpath:
2261         POLICY_RDUNLOCK;
2262         if (rc == 0)
2263                 /* at present NetLabel SIDs/labels really only carry MLS
2264                  * information so if the MLS portion of the NetLabel SID
2265                  * matches the MLS portion of the labeled XFRM SID/label
2266                  * then pass along the XFRM SID as it is the most
2267                  * expressive */
2268                 *peer_sid = xfrm_sid;
2269         else
2270                 *peer_sid = SECSID_NULL;
2271         return rc;
2272 }
2273
2274 static int get_classes_callback(void *k, void *d, void *args)
2275 {
2276         struct class_datum *datum = d;
2277         char *name = k, **classes = args;
2278         int value = datum->value - 1;
2279
2280         classes[value] = kstrdup(name, GFP_ATOMIC);
2281         if (!classes[value])
2282                 return -ENOMEM;
2283
2284         return 0;
2285 }
2286
2287 int security_get_classes(char ***classes, int *nclasses)
2288 {
2289         int rc = -ENOMEM;
2290
2291         POLICY_RDLOCK;
2292
2293         *nclasses = policydb.p_classes.nprim;
2294         *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2295         if (!*classes)
2296                 goto out;
2297
2298         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2299                         *classes);
2300         if (rc < 0) {
2301                 int i;
2302                 for (i = 0; i < *nclasses; i++)
2303                         kfree((*classes)[i]);
2304                 kfree(*classes);
2305         }
2306
2307 out:
2308         POLICY_RDUNLOCK;
2309         return rc;
2310 }
2311
2312 static int get_permissions_callback(void *k, void *d, void *args)
2313 {
2314         struct perm_datum *datum = d;
2315         char *name = k, **perms = args;
2316         int value = datum->value - 1;
2317
2318         perms[value] = kstrdup(name, GFP_ATOMIC);
2319         if (!perms[value])
2320                 return -ENOMEM;
2321
2322         return 0;
2323 }
2324
2325 int security_get_permissions(char *class, char ***perms, int *nperms)
2326 {
2327         int rc = -ENOMEM, i;
2328         struct class_datum *match;
2329
2330         POLICY_RDLOCK;
2331
2332         match = hashtab_search(policydb.p_classes.table, class);
2333         if (!match) {
2334                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2335                         __func__, class);
2336                 rc = -EINVAL;
2337                 goto out;
2338         }
2339
2340         *nperms = match->permissions.nprim;
2341         *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2342         if (!*perms)
2343                 goto out;
2344
2345         if (match->comdatum) {
2346                 rc = hashtab_map(match->comdatum->permissions.table,
2347                                 get_permissions_callback, *perms);
2348                 if (rc < 0)
2349                         goto err;
2350         }
2351
2352         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2353                         *perms);
2354         if (rc < 0)
2355                 goto err;
2356
2357 out:
2358         POLICY_RDUNLOCK;
2359         return rc;
2360
2361 err:
2362         POLICY_RDUNLOCK;
2363         for (i = 0; i < *nperms; i++)
2364                 kfree((*perms)[i]);
2365         kfree(*perms);
2366         return rc;
2367 }
2368
2369 int security_get_reject_unknown(void)
2370 {
2371         return policydb.reject_unknown;
2372 }
2373
2374 int security_get_allow_unknown(void)
2375 {
2376         return policydb.allow_unknown;
2377 }
2378
2379 /**
2380  * security_policycap_supported - Check for a specific policy capability
2381  * @req_cap: capability
2382  *
2383  * Description:
2384  * This function queries the currently loaded policy to see if it supports the
2385  * capability specified by @req_cap.  Returns true (1) if the capability is
2386  * supported, false (0) if it isn't supported.
2387  *
2388  */
2389 int security_policycap_supported(unsigned int req_cap)
2390 {
2391         int rc;
2392
2393         POLICY_RDLOCK;
2394         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2395         POLICY_RDUNLOCK;
2396
2397         return rc;
2398 }
2399
2400 struct selinux_audit_rule {
2401         u32 au_seqno;
2402         struct context au_ctxt;
2403 };
2404
2405 void selinux_audit_rule_free(void *vrule)
2406 {
2407         struct selinux_audit_rule *rule = vrule;
2408
2409         if (rule) {
2410                 context_destroy(&rule->au_ctxt);
2411                 kfree(rule);
2412         }
2413 }
2414
2415 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2416 {
2417         struct selinux_audit_rule *tmprule;
2418         struct role_datum *roledatum;
2419         struct type_datum *typedatum;
2420         struct user_datum *userdatum;
2421         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2422         int rc = 0;
2423
2424         *rule = NULL;
2425
2426         if (!ss_initialized)
2427                 return -EOPNOTSUPP;
2428
2429         switch (field) {
2430         case AUDIT_SUBJ_USER:
2431         case AUDIT_SUBJ_ROLE:
2432         case AUDIT_SUBJ_TYPE:
2433         case AUDIT_OBJ_USER:
2434         case AUDIT_OBJ_ROLE:
2435         case AUDIT_OBJ_TYPE:
2436                 /* only 'equals' and 'not equals' fit user, role, and type */
2437                 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2438                         return -EINVAL;
2439                 break;
2440         case AUDIT_SUBJ_SEN:
2441         case AUDIT_SUBJ_CLR:
2442         case AUDIT_OBJ_LEV_LOW:
2443         case AUDIT_OBJ_LEV_HIGH:
2444                 /* we do not allow a range, indicated by the presense of '-' */
2445                 if (strchr(rulestr, '-'))
2446                         return -EINVAL;
2447                 break;
2448         default:
2449                 /* only the above fields are valid */
2450                 return -EINVAL;
2451         }
2452
2453         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2454         if (!tmprule)
2455                 return -ENOMEM;
2456
2457         context_init(&tmprule->au_ctxt);
2458
2459         POLICY_RDLOCK;
2460
2461         tmprule->au_seqno = latest_granting;
2462
2463         switch (field) {
2464         case AUDIT_SUBJ_USER:
2465         case AUDIT_OBJ_USER:
2466                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2467                 if (!userdatum)
2468                         rc = -EINVAL;
2469                 else
2470                         tmprule->au_ctxt.user = userdatum->value;
2471                 break;
2472         case AUDIT_SUBJ_ROLE:
2473         case AUDIT_OBJ_ROLE:
2474                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2475                 if (!roledatum)
2476                         rc = -EINVAL;
2477                 else
2478                         tmprule->au_ctxt.role = roledatum->value;
2479                 break;
2480         case AUDIT_SUBJ_TYPE:
2481         case AUDIT_OBJ_TYPE:
2482                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2483                 if (!typedatum)
2484                         rc = -EINVAL;
2485                 else
2486                         tmprule->au_ctxt.type = typedatum->value;
2487                 break;
2488         case AUDIT_SUBJ_SEN:
2489         case AUDIT_SUBJ_CLR:
2490         case AUDIT_OBJ_LEV_LOW:
2491         case AUDIT_OBJ_LEV_HIGH:
2492                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2493                 break;
2494         }
2495
2496         POLICY_RDUNLOCK;
2497
2498         if (rc) {
2499                 selinux_audit_rule_free(tmprule);
2500                 tmprule = NULL;
2501         }
2502
2503         *rule = tmprule;
2504
2505         return rc;
2506 }
2507
2508 /* Check to see if the rule contains any selinux fields */
2509 int selinux_audit_rule_known(struct audit_krule *rule)
2510 {
2511         int i;
2512
2513         for (i = 0; i < rule->field_count; i++) {
2514                 struct audit_field *f = &rule->fields[i];
2515                 switch (f->type) {
2516                 case AUDIT_SUBJ_USER:
2517                 case AUDIT_SUBJ_ROLE:
2518                 case AUDIT_SUBJ_TYPE:
2519                 case AUDIT_SUBJ_SEN:
2520                 case AUDIT_SUBJ_CLR:
2521                 case AUDIT_OBJ_USER:
2522                 case AUDIT_OBJ_ROLE:
2523                 case AUDIT_OBJ_TYPE:
2524                 case AUDIT_OBJ_LEV_LOW:
2525                 case AUDIT_OBJ_LEV_HIGH:
2526                         return 1;
2527                 }
2528         }
2529
2530         return 0;
2531 }
2532
2533 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2534                              struct audit_context *actx)
2535 {
2536         struct context *ctxt;
2537         struct mls_level *level;
2538         struct selinux_audit_rule *rule = vrule;
2539         int match = 0;
2540
2541         if (!rule) {
2542                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2543                           "selinux_audit_rule_match: missing rule\n");
2544                 return -ENOENT;
2545         }
2546
2547         POLICY_RDLOCK;
2548
2549         if (rule->au_seqno < latest_granting) {
2550                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2551                           "selinux_audit_rule_match: stale rule\n");
2552                 match = -ESTALE;
2553                 goto out;
2554         }
2555
2556         ctxt = sidtab_search(&sidtab, sid);
2557         if (!ctxt) {
2558                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2559                           "selinux_audit_rule_match: unrecognized SID %d\n",
2560                           sid);
2561                 match = -ENOENT;
2562                 goto out;
2563         }
2564
2565         /* a field/op pair that is not caught here will simply fall through
2566            without a match */
2567         switch (field) {
2568         case AUDIT_SUBJ_USER:
2569         case AUDIT_OBJ_USER:
2570                 switch (op) {
2571                 case AUDIT_EQUAL:
2572                         match = (ctxt->user == rule->au_ctxt.user);
2573                         break;
2574                 case AUDIT_NOT_EQUAL:
2575                         match = (ctxt->user != rule->au_ctxt.user);
2576                         break;
2577                 }
2578                 break;
2579         case AUDIT_SUBJ_ROLE:
2580         case AUDIT_OBJ_ROLE:
2581                 switch (op) {
2582                 case AUDIT_EQUAL:
2583                         match = (ctxt->role == rule->au_ctxt.role);
2584                         break;
2585                 case AUDIT_NOT_EQUAL:
2586                         match = (ctxt->role != rule->au_ctxt.role);
2587                         break;
2588                 }
2589                 break;
2590         case AUDIT_SUBJ_TYPE:
2591         case AUDIT_OBJ_TYPE:
2592                 switch (op) {
2593                 case AUDIT_EQUAL:
2594                         match = (ctxt->type == rule->au_ctxt.type);
2595                         break;
2596                 case AUDIT_NOT_EQUAL:
2597                         match = (ctxt->type != rule->au_ctxt.type);
2598                         break;
2599                 }
2600                 break;
2601         case AUDIT_SUBJ_SEN:
2602         case AUDIT_SUBJ_CLR:
2603         case AUDIT_OBJ_LEV_LOW:
2604         case AUDIT_OBJ_LEV_HIGH:
2605                 level = ((field == AUDIT_SUBJ_SEN ||
2606                           field == AUDIT_OBJ_LEV_LOW) ?
2607                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2608                 switch (op) {
2609                 case AUDIT_EQUAL:
2610                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2611                                              level);
2612                         break;
2613                 case AUDIT_NOT_EQUAL:
2614                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2615                                               level);
2616                         break;
2617                 case AUDIT_LESS_THAN:
2618                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2619                                                level) &&
2620                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2621                                                level));
2622                         break;
2623                 case AUDIT_LESS_THAN_OR_EQUAL:
2624                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2625                                               level);
2626                         break;
2627                 case AUDIT_GREATER_THAN:
2628                         match = (mls_level_dom(level,
2629                                               &rule->au_ctxt.range.level[0]) &&
2630                                  !mls_level_eq(level,
2631                                                &rule->au_ctxt.range.level[0]));
2632                         break;
2633                 case AUDIT_GREATER_THAN_OR_EQUAL:
2634                         match = mls_level_dom(level,
2635                                               &rule->au_ctxt.range.level[0]);
2636                         break;
2637                 }
2638         }
2639
2640 out:
2641         POLICY_RDUNLOCK;
2642         return match;
2643 }
2644
2645 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2646
2647 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2648                                u16 class, u32 perms, u32 *retained)
2649 {
2650         int err = 0;
2651
2652         if (event == AVC_CALLBACK_RESET && aurule_callback)
2653                 err = aurule_callback();
2654         return err;
2655 }
2656
2657 static int __init aurule_init(void)
2658 {
2659         int err;
2660
2661         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2662                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2663         if (err)
2664                 panic("avc_add_callback() failed, error %d\n", err);
2665
2666         return err;
2667 }
2668 __initcall(aurule_init);
2669
2670 #ifdef CONFIG_NETLABEL
2671 /**
2672  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2673  * @secattr: the NetLabel packet security attributes
2674  * @sid: the SELinux SID
2675  *
2676  * Description:
2677  * Attempt to cache the context in @ctx, which was derived from the packet in
2678  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2679  * already been initialized.
2680  *
2681  */
2682 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2683                                       u32 sid)
2684 {
2685         u32 *sid_cache;
2686
2687         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2688         if (sid_cache == NULL)
2689                 return;
2690         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2691         if (secattr->cache == NULL) {
2692                 kfree(sid_cache);
2693                 return;
2694         }
2695
2696         *sid_cache = sid;
2697         secattr->cache->free = kfree;
2698         secattr->cache->data = sid_cache;
2699         secattr->flags |= NETLBL_SECATTR_CACHE;
2700 }
2701
2702 /**
2703  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2704  * @secattr: the NetLabel packet security attributes
2705  * @sid: the SELinux SID
2706  *
2707  * Description:
2708  * Convert the given NetLabel security attributes in @secattr into a
2709  * SELinux SID.  If the @secattr field does not contain a full SELinux
2710  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2711  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2712  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2713  * conversion for future lookups.  Returns zero on success, negative values on
2714  * failure.
2715  *
2716  */
2717 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2718                                    u32 *sid)
2719 {
2720         int rc = -EIDRM;
2721         struct context *ctx;
2722         struct context ctx_new;
2723
2724         if (!ss_initialized) {
2725                 *sid = SECSID_NULL;
2726                 return 0;
2727         }
2728
2729         POLICY_RDLOCK;
2730
2731         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2732                 *sid = *(u32 *)secattr->cache->data;
2733                 rc = 0;
2734         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2735                 *sid = secattr->attr.secid;
2736                 rc = 0;
2737         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2738                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2739                 if (ctx == NULL)
2740                         goto netlbl_secattr_to_sid_return;
2741
2742                 ctx_new.user = ctx->user;
2743                 ctx_new.role = ctx->role;
2744                 ctx_new.type = ctx->type;
2745                 mls_import_netlbl_lvl(&ctx_new, secattr);
2746                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2747                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2748                                                   secattr->attr.mls.cat) != 0)
2749                                 goto netlbl_secattr_to_sid_return;
2750                         ctx_new.range.level[1].cat.highbit =
2751                                 ctx_new.range.level[0].cat.highbit;
2752                         ctx_new.range.level[1].cat.node =
2753                                 ctx_new.range.level[0].cat.node;
2754                 } else {
2755                         ebitmap_init(&ctx_new.range.level[0].cat);
2756                         ebitmap_init(&ctx_new.range.level[1].cat);
2757                 }
2758                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2759                         goto netlbl_secattr_to_sid_return_cleanup;
2760
2761                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2762                 if (rc != 0)
2763                         goto netlbl_secattr_to_sid_return_cleanup;
2764
2765                 security_netlbl_cache_add(secattr, *sid);
2766
2767                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2768         } else {
2769                 *sid = SECSID_NULL;
2770                 rc = 0;
2771         }
2772
2773 netlbl_secattr_to_sid_return:
2774         POLICY_RDUNLOCK;
2775         return rc;
2776 netlbl_secattr_to_sid_return_cleanup:
2777         ebitmap_destroy(&ctx_new.range.level[0].cat);
2778         goto netlbl_secattr_to_sid_return;
2779 }
2780
2781 /**
2782  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2783  * @sid: the SELinux SID
2784  * @secattr: the NetLabel packet security attributes
2785  *
2786  * Description:
2787  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2788  * Returns zero on success, negative values on failure.
2789  *
2790  */
2791 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2792 {
2793         int rc = -ENOENT;
2794         struct context *ctx;
2795
2796         if (!ss_initialized)
2797                 return 0;
2798
2799         POLICY_RDLOCK;
2800         ctx = sidtab_search(&sidtab, sid);
2801         if (ctx == NULL)
2802                 goto netlbl_sid_to_secattr_failure;
2803         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2804                                   GFP_ATOMIC);
2805         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY;
2806         mls_export_netlbl_lvl(ctx, secattr);
2807         rc = mls_export_netlbl_cat(ctx, secattr);
2808         if (rc != 0)
2809                 goto netlbl_sid_to_secattr_failure;
2810         POLICY_RDUNLOCK;
2811
2812         return 0;
2813
2814 netlbl_sid_to_secattr_failure:
2815         POLICY_RDUNLOCK;
2816         return rc;
2817 }
2818 #endif /* CONFIG_NETLABEL */