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