b66b454fe72b41ca5559aa636e9252cd6619ba93
[linux-3.10.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  *
20  * Updated: Chad Sellers <csellers@tresys.com>
21  *
22  *  Added validation of kernel classes and permissions
23  *
24  * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
25  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
26  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
27  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
28  *      This program is free software; you can redistribute it and/or modify
29  *      it under the terms of the GNU General Public License as published by
30  *      the Free Software Foundation, version 2.
31  */
32 #include <linux/kernel.h>
33 #include <linux/slab.h>
34 #include <linux/string.h>
35 #include <linux/spinlock.h>
36 #include <linux/rcupdate.h>
37 #include <linux/errno.h>
38 #include <linux/in.h>
39 #include <linux/sched.h>
40 #include <linux/audit.h>
41 #include <linux/mutex.h>
42 #include <net/sock.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 "selinux_netlabel.h"
57
58 extern void selnl_notify_policyload(u32 seqno);
59 unsigned int policydb_loaded_version;
60
61 /*
62  * This is declared in avc.c
63  */
64 extern const struct selinux_class_perm selinux_class_perm;
65
66 static DEFINE_RWLOCK(policy_rwlock);
67 #define POLICY_RDLOCK read_lock(&policy_rwlock)
68 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
69 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
70 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
71
72 static DEFINE_MUTEX(load_mutex);
73 #define LOAD_LOCK mutex_lock(&load_mutex)
74 #define LOAD_UNLOCK mutex_unlock(&load_mutex)
75
76 static struct sidtab sidtab;
77 struct policydb policydb;
78 int ss_initialized = 0;
79
80 /*
81  * The largest sequence number that has been used when
82  * providing an access decision to the access vector cache.
83  * The sequence number only changes when a policy change
84  * occurs.
85  */
86 static u32 latest_granting = 0;
87
88 /* Forward declaration. */
89 static int context_struct_to_string(struct context *context, char **scontext,
90                                     u32 *scontext_len);
91
92 /*
93  * Return the boolean value of a constraint expression
94  * when it is applied to the specified source and target
95  * security contexts.
96  *
97  * xcontext is a special beast...  It is used by the validatetrans rules
98  * only.  For these rules, scontext is the context before the transition,
99  * tcontext is the context after the transition, and xcontext is the context
100  * of the process performing the transition.  All other callers of
101  * constraint_expr_eval should pass in NULL for xcontext.
102  */
103 static int constraint_expr_eval(struct context *scontext,
104                                 struct context *tcontext,
105                                 struct context *xcontext,
106                                 struct constraint_expr *cexpr)
107 {
108         u32 val1, val2;
109         struct context *c;
110         struct role_datum *r1, *r2;
111         struct mls_level *l1, *l2;
112         struct constraint_expr *e;
113         int s[CEXPR_MAXDEPTH];
114         int sp = -1;
115
116         for (e = cexpr; e; e = e->next) {
117                 switch (e->expr_type) {
118                 case CEXPR_NOT:
119                         BUG_ON(sp < 0);
120                         s[sp] = !s[sp];
121                         break;
122                 case CEXPR_AND:
123                         BUG_ON(sp < 1);
124                         sp--;
125                         s[sp] &= s[sp+1];
126                         break;
127                 case CEXPR_OR:
128                         BUG_ON(sp < 1);
129                         sp--;
130                         s[sp] |= s[sp+1];
131                         break;
132                 case CEXPR_ATTR:
133                         if (sp == (CEXPR_MAXDEPTH-1))
134                                 return 0;
135                         switch (e->attr) {
136                         case CEXPR_USER:
137                                 val1 = scontext->user;
138                                 val2 = tcontext->user;
139                                 break;
140                         case CEXPR_TYPE:
141                                 val1 = scontext->type;
142                                 val2 = tcontext->type;
143                                 break;
144                         case CEXPR_ROLE:
145                                 val1 = scontext->role;
146                                 val2 = tcontext->role;
147                                 r1 = policydb.role_val_to_struct[val1 - 1];
148                                 r2 = policydb.role_val_to_struct[val2 - 1];
149                                 switch (e->op) {
150                                 case CEXPR_DOM:
151                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
152                                                                   val2 - 1);
153                                         continue;
154                                 case CEXPR_DOMBY:
155                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
156                                                                   val1 - 1);
157                                         continue;
158                                 case CEXPR_INCOMP:
159                                         s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
160                                                                      val2 - 1) &&
161                                                     !ebitmap_get_bit(&r2->dominates,
162                                                                      val1 - 1) );
163                                         continue;
164                                 default:
165                                         break;
166                                 }
167                                 break;
168                         case CEXPR_L1L2:
169                                 l1 = &(scontext->range.level[0]);
170                                 l2 = &(tcontext->range.level[0]);
171                                 goto mls_ops;
172                         case CEXPR_L1H2:
173                                 l1 = &(scontext->range.level[0]);
174                                 l2 = &(tcontext->range.level[1]);
175                                 goto mls_ops;
176                         case CEXPR_H1L2:
177                                 l1 = &(scontext->range.level[1]);
178                                 l2 = &(tcontext->range.level[0]);
179                                 goto mls_ops;
180                         case CEXPR_H1H2:
181                                 l1 = &(scontext->range.level[1]);
182                                 l2 = &(tcontext->range.level[1]);
183                                 goto mls_ops;
184                         case CEXPR_L1H1:
185                                 l1 = &(scontext->range.level[0]);
186                                 l2 = &(scontext->range.level[1]);
187                                 goto mls_ops;
188                         case CEXPR_L2H2:
189                                 l1 = &(tcontext->range.level[0]);
190                                 l2 = &(tcontext->range.level[1]);
191                                 goto mls_ops;
192 mls_ops:
193                         switch (e->op) {
194                         case CEXPR_EQ:
195                                 s[++sp] = mls_level_eq(l1, l2);
196                                 continue;
197                         case CEXPR_NEQ:
198                                 s[++sp] = !mls_level_eq(l1, l2);
199                                 continue;
200                         case CEXPR_DOM:
201                                 s[++sp] = mls_level_dom(l1, l2);
202                                 continue;
203                         case CEXPR_DOMBY:
204                                 s[++sp] = mls_level_dom(l2, l1);
205                                 continue;
206                         case CEXPR_INCOMP:
207                                 s[++sp] = mls_level_incomp(l2, l1);
208                                 continue;
209                         default:
210                                 BUG();
211                                 return 0;
212                         }
213                         break;
214                         default:
215                                 BUG();
216                                 return 0;
217                         }
218
219                         switch (e->op) {
220                         case CEXPR_EQ:
221                                 s[++sp] = (val1 == val2);
222                                 break;
223                         case CEXPR_NEQ:
224                                 s[++sp] = (val1 != val2);
225                                 break;
226                         default:
227                                 BUG();
228                                 return 0;
229                         }
230                         break;
231                 case CEXPR_NAMES:
232                         if (sp == (CEXPR_MAXDEPTH-1))
233                                 return 0;
234                         c = scontext;
235                         if (e->attr & CEXPR_TARGET)
236                                 c = tcontext;
237                         else if (e->attr & CEXPR_XTARGET) {
238                                 c = xcontext;
239                                 if (!c) {
240                                         BUG();
241                                         return 0;
242                                 }
243                         }
244                         if (e->attr & CEXPR_USER)
245                                 val1 = c->user;
246                         else if (e->attr & CEXPR_ROLE)
247                                 val1 = c->role;
248                         else if (e->attr & CEXPR_TYPE)
249                                 val1 = c->type;
250                         else {
251                                 BUG();
252                                 return 0;
253                         }
254
255                         switch (e->op) {
256                         case CEXPR_EQ:
257                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
258                                 break;
259                         case CEXPR_NEQ:
260                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
261                                 break;
262                         default:
263                                 BUG();
264                                 return 0;
265                         }
266                         break;
267                 default:
268                         BUG();
269                         return 0;
270                 }
271         }
272
273         BUG_ON(sp != 0);
274         return s[0];
275 }
276
277 /*
278  * Compute access vectors based on a context structure pair for
279  * the permissions in a particular class.
280  */
281 static int context_struct_compute_av(struct context *scontext,
282                                      struct context *tcontext,
283                                      u16 tclass,
284                                      u32 requested,
285                                      struct av_decision *avd)
286 {
287         struct constraint_node *constraint;
288         struct role_allow *ra;
289         struct avtab_key avkey;
290         struct avtab_node *node;
291         struct class_datum *tclass_datum;
292         struct ebitmap *sattr, *tattr;
293         struct ebitmap_node *snode, *tnode;
294         unsigned int i, j;
295
296         /*
297          * Remap extended Netlink classes for old policy versions.
298          * Do this here rather than socket_type_to_security_class()
299          * in case a newer policy version is loaded, allowing sockets
300          * to remain in the correct class.
301          */
302         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
303                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
304                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
305                         tclass = SECCLASS_NETLINK_SOCKET;
306
307         if (!tclass || tclass > policydb.p_classes.nprim) {
308                 printk(KERN_ERR "security_compute_av:  unrecognized class %d\n",
309                        tclass);
310                 return -EINVAL;
311         }
312         tclass_datum = policydb.class_val_to_struct[tclass - 1];
313
314         /*
315          * Initialize the access vectors to the default values.
316          */
317         avd->allowed = 0;
318         avd->decided = 0xffffffff;
319         avd->auditallow = 0;
320         avd->auditdeny = 0xffffffff;
321         avd->seqno = latest_granting;
322
323         /*
324          * If a specific type enforcement rule was defined for
325          * this permission check, then use it.
326          */
327         avkey.target_class = tclass;
328         avkey.specified = AVTAB_AV;
329         sattr = &policydb.type_attr_map[scontext->type - 1];
330         tattr = &policydb.type_attr_map[tcontext->type - 1];
331         ebitmap_for_each_bit(sattr, snode, i) {
332                 if (!ebitmap_node_get_bit(snode, i))
333                         continue;
334                 ebitmap_for_each_bit(tattr, tnode, j) {
335                         if (!ebitmap_node_get_bit(tnode, j))
336                                 continue;
337                         avkey.source_type = i + 1;
338                         avkey.target_type = j + 1;
339                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
340                              node != NULL;
341                              node = avtab_search_node_next(node, avkey.specified)) {
342                                 if (node->key.specified == AVTAB_ALLOWED)
343                                         avd->allowed |= node->datum.data;
344                                 else if (node->key.specified == AVTAB_AUDITALLOW)
345                                         avd->auditallow |= node->datum.data;
346                                 else if (node->key.specified == AVTAB_AUDITDENY)
347                                         avd->auditdeny &= node->datum.data;
348                         }
349
350                         /* Check conditional av table for additional permissions */
351                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
352
353                 }
354         }
355
356         /*
357          * Remove any permissions prohibited by a constraint (this includes
358          * the MLS policy).
359          */
360         constraint = tclass_datum->constraints;
361         while (constraint) {
362                 if ((constraint->permissions & (avd->allowed)) &&
363                     !constraint_expr_eval(scontext, tcontext, NULL,
364                                           constraint->expr)) {
365                         avd->allowed = (avd->allowed) & ~(constraint->permissions);
366                 }
367                 constraint = constraint->next;
368         }
369
370         /*
371          * If checking process transition permission and the
372          * role is changing, then check the (current_role, new_role)
373          * pair.
374          */
375         if (tclass == SECCLASS_PROCESS &&
376             (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
377             scontext->role != tcontext->role) {
378                 for (ra = policydb.role_allow; ra; ra = ra->next) {
379                         if (scontext->role == ra->role &&
380                             tcontext->role == ra->new_role)
381                                 break;
382                 }
383                 if (!ra)
384                         avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
385                                                         PROCESS__DYNTRANSITION);
386         }
387
388         return 0;
389 }
390
391 static int security_validtrans_handle_fail(struct context *ocontext,
392                                            struct context *ncontext,
393                                            struct context *tcontext,
394                                            u16 tclass)
395 {
396         char *o = NULL, *n = NULL, *t = NULL;
397         u32 olen, nlen, tlen;
398
399         if (context_struct_to_string(ocontext, &o, &olen) < 0)
400                 goto out;
401         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
402                 goto out;
403         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
404                 goto out;
405         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
406                   "security_validate_transition:  denied for"
407                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
408                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
409 out:
410         kfree(o);
411         kfree(n);
412         kfree(t);
413
414         if (!selinux_enforcing)
415                 return 0;
416         return -EPERM;
417 }
418
419 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
420                                  u16 tclass)
421 {
422         struct context *ocontext;
423         struct context *ncontext;
424         struct context *tcontext;
425         struct class_datum *tclass_datum;
426         struct constraint_node *constraint;
427         int rc = 0;
428
429         if (!ss_initialized)
430                 return 0;
431
432         POLICY_RDLOCK;
433
434         /*
435          * Remap extended Netlink classes for old policy versions.
436          * Do this here rather than socket_type_to_security_class()
437          * in case a newer policy version is loaded, allowing sockets
438          * to remain in the correct class.
439          */
440         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
441                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
442                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
443                         tclass = SECCLASS_NETLINK_SOCKET;
444
445         if (!tclass || tclass > policydb.p_classes.nprim) {
446                 printk(KERN_ERR "security_validate_transition:  "
447                        "unrecognized class %d\n", tclass);
448                 rc = -EINVAL;
449                 goto out;
450         }
451         tclass_datum = policydb.class_val_to_struct[tclass - 1];
452
453         ocontext = sidtab_search(&sidtab, oldsid);
454         if (!ocontext) {
455                 printk(KERN_ERR "security_validate_transition: "
456                        " unrecognized SID %d\n", oldsid);
457                 rc = -EINVAL;
458                 goto out;
459         }
460
461         ncontext = sidtab_search(&sidtab, newsid);
462         if (!ncontext) {
463                 printk(KERN_ERR "security_validate_transition: "
464                        " unrecognized SID %d\n", newsid);
465                 rc = -EINVAL;
466                 goto out;
467         }
468
469         tcontext = sidtab_search(&sidtab, tasksid);
470         if (!tcontext) {
471                 printk(KERN_ERR "security_validate_transition: "
472                        " unrecognized SID %d\n", tasksid);
473                 rc = -EINVAL;
474                 goto out;
475         }
476
477         constraint = tclass_datum->validatetrans;
478         while (constraint) {
479                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
480                                           constraint->expr)) {
481                         rc = security_validtrans_handle_fail(ocontext, ncontext,
482                                                              tcontext, tclass);
483                         goto out;
484                 }
485                 constraint = constraint->next;
486         }
487
488 out:
489         POLICY_RDUNLOCK;
490         return rc;
491 }
492
493 /**
494  * security_compute_av - Compute access vector decisions.
495  * @ssid: source security identifier
496  * @tsid: target security identifier
497  * @tclass: target security class
498  * @requested: requested permissions
499  * @avd: access vector decisions
500  *
501  * Compute a set of access vector decisions based on the
502  * SID pair (@ssid, @tsid) for the permissions in @tclass.
503  * Return -%EINVAL if any of the parameters are invalid or %0
504  * if the access vector decisions were computed successfully.
505  */
506 int security_compute_av(u32 ssid,
507                         u32 tsid,
508                         u16 tclass,
509                         u32 requested,
510                         struct av_decision *avd)
511 {
512         struct context *scontext = NULL, *tcontext = NULL;
513         int rc = 0;
514
515         if (!ss_initialized) {
516                 avd->allowed = 0xffffffff;
517                 avd->decided = 0xffffffff;
518                 avd->auditallow = 0;
519                 avd->auditdeny = 0xffffffff;
520                 avd->seqno = latest_granting;
521                 return 0;
522         }
523
524         POLICY_RDLOCK;
525
526         scontext = sidtab_search(&sidtab, ssid);
527         if (!scontext) {
528                 printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
529                        ssid);
530                 rc = -EINVAL;
531                 goto out;
532         }
533         tcontext = sidtab_search(&sidtab, tsid);
534         if (!tcontext) {
535                 printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
536                        tsid);
537                 rc = -EINVAL;
538                 goto out;
539         }
540
541         rc = context_struct_compute_av(scontext, tcontext, tclass,
542                                        requested, avd);
543 out:
544         POLICY_RDUNLOCK;
545         return rc;
546 }
547
548 /*
549  * Write the security context string representation of
550  * the context structure `context' into a dynamically
551  * allocated string of the correct size.  Set `*scontext'
552  * to point to this string and set `*scontext_len' to
553  * the length of the string.
554  */
555 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
556 {
557         char *scontextp;
558
559         *scontext = NULL;
560         *scontext_len = 0;
561
562         /* Compute the size of the context. */
563         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
564         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
565         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
566         *scontext_len += mls_compute_context_len(context);
567
568         /* Allocate space for the context; caller must free this space. */
569         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
570         if (!scontextp) {
571                 return -ENOMEM;
572         }
573         *scontext = scontextp;
574
575         /*
576          * Copy the user name, role name and type name into the context.
577          */
578         sprintf(scontextp, "%s:%s:%s",
579                 policydb.p_user_val_to_name[context->user - 1],
580                 policydb.p_role_val_to_name[context->role - 1],
581                 policydb.p_type_val_to_name[context->type - 1]);
582         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
583                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
584                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
585
586         mls_sid_to_context(context, &scontextp);
587
588         *scontextp = 0;
589
590         return 0;
591 }
592
593 #include "initial_sid_to_string.h"
594
595 /**
596  * security_sid_to_context - Obtain a context for a given SID.
597  * @sid: security identifier, SID
598  * @scontext: security context
599  * @scontext_len: length in bytes
600  *
601  * Write the string representation of the context associated with @sid
602  * into a dynamically allocated string of the correct size.  Set @scontext
603  * to point to this string and set @scontext_len to the length of the string.
604  */
605 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
606 {
607         struct context *context;
608         int rc = 0;
609
610         if (!ss_initialized) {
611                 if (sid <= SECINITSID_NUM) {
612                         char *scontextp;
613
614                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
615                         scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
616                         if (!scontextp) {
617                                 rc = -ENOMEM;
618                                 goto out;
619                         }
620                         strcpy(scontextp, initial_sid_to_string[sid]);
621                         *scontext = scontextp;
622                         goto out;
623                 }
624                 printk(KERN_ERR "security_sid_to_context:  called before initial "
625                        "load_policy on unknown SID %d\n", sid);
626                 rc = -EINVAL;
627                 goto out;
628         }
629         POLICY_RDLOCK;
630         context = sidtab_search(&sidtab, sid);
631         if (!context) {
632                 printk(KERN_ERR "security_sid_to_context:  unrecognized SID "
633                        "%d\n", sid);
634                 rc = -EINVAL;
635                 goto out_unlock;
636         }
637         rc = context_struct_to_string(context, scontext, scontext_len);
638 out_unlock:
639         POLICY_RDUNLOCK;
640 out:
641         return rc;
642
643 }
644
645 static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
646 {
647         char *scontext2;
648         struct context context;
649         struct role_datum *role;
650         struct type_datum *typdatum;
651         struct user_datum *usrdatum;
652         char *scontextp, *p, oldc;
653         int rc = 0;
654
655         if (!ss_initialized) {
656                 int i;
657
658                 for (i = 1; i < SECINITSID_NUM; i++) {
659                         if (!strcmp(initial_sid_to_string[i], scontext)) {
660                                 *sid = i;
661                                 goto out;
662                         }
663                 }
664                 *sid = SECINITSID_KERNEL;
665                 goto out;
666         }
667         *sid = SECSID_NULL;
668
669         /* Copy the string so that we can modify the copy as we parse it.
670            The string should already by null terminated, but we append a
671            null suffix to the copy to avoid problems with the existing
672            attr package, which doesn't view the null terminator as part
673            of the attribute value. */
674         scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
675         if (!scontext2) {
676                 rc = -ENOMEM;
677                 goto out;
678         }
679         memcpy(scontext2, scontext, scontext_len);
680         scontext2[scontext_len] = 0;
681
682         context_init(&context);
683         *sid = SECSID_NULL;
684
685         POLICY_RDLOCK;
686
687         /* Parse the security context. */
688
689         rc = -EINVAL;
690         scontextp = (char *) scontext2;
691
692         /* Extract the user. */
693         p = scontextp;
694         while (*p && *p != ':')
695                 p++;
696
697         if (*p == 0)
698                 goto out_unlock;
699
700         *p++ = 0;
701
702         usrdatum = hashtab_search(policydb.p_users.table, scontextp);
703         if (!usrdatum)
704                 goto out_unlock;
705
706         context.user = usrdatum->value;
707
708         /* Extract role. */
709         scontextp = p;
710         while (*p && *p != ':')
711                 p++;
712
713         if (*p == 0)
714                 goto out_unlock;
715
716         *p++ = 0;
717
718         role = hashtab_search(policydb.p_roles.table, scontextp);
719         if (!role)
720                 goto out_unlock;
721         context.role = role->value;
722
723         /* Extract type. */
724         scontextp = p;
725         while (*p && *p != ':')
726                 p++;
727         oldc = *p;
728         *p++ = 0;
729
730         typdatum = hashtab_search(policydb.p_types.table, scontextp);
731         if (!typdatum)
732                 goto out_unlock;
733
734         context.type = typdatum->value;
735
736         rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
737         if (rc)
738                 goto out_unlock;
739
740         if ((p - scontext2) < scontext_len) {
741                 rc = -EINVAL;
742                 goto out_unlock;
743         }
744
745         /* Check the validity of the new context. */
746         if (!policydb_context_isvalid(&policydb, &context)) {
747                 rc = -EINVAL;
748                 goto out_unlock;
749         }
750         /* Obtain the new sid. */
751         rc = sidtab_context_to_sid(&sidtab, &context, sid);
752 out_unlock:
753         POLICY_RDUNLOCK;
754         context_destroy(&context);
755         kfree(scontext2);
756 out:
757         return rc;
758 }
759
760 /**
761  * security_context_to_sid - Obtain a SID for a given security context.
762  * @scontext: security context
763  * @scontext_len: length in bytes
764  * @sid: security identifier, SID
765  *
766  * Obtains a SID associated with the security context that
767  * has the string representation specified by @scontext.
768  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
769  * memory is available, or 0 on success.
770  */
771 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
772 {
773         return security_context_to_sid_core(scontext, scontext_len,
774                                             sid, SECSID_NULL);
775 }
776
777 /**
778  * security_context_to_sid_default - Obtain a SID for a given security context,
779  * falling back to specified default if needed.
780  *
781  * @scontext: security context
782  * @scontext_len: length in bytes
783  * @sid: security identifier, SID
784  * @def_sid: default SID to assign on errror
785  *
786  * Obtains a SID associated with the security context that
787  * has the string representation specified by @scontext.
788  * The default SID is passed to the MLS layer to be used to allow
789  * kernel labeling of the MLS field if the MLS field is not present
790  * (for upgrading to MLS without full relabel).
791  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
792  * memory is available, or 0 on success.
793  */
794 int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
795 {
796         return security_context_to_sid_core(scontext, scontext_len,
797                                             sid, def_sid);
798 }
799
800 static int compute_sid_handle_invalid_context(
801         struct context *scontext,
802         struct context *tcontext,
803         u16 tclass,
804         struct context *newcontext)
805 {
806         char *s = NULL, *t = NULL, *n = NULL;
807         u32 slen, tlen, nlen;
808
809         if (context_struct_to_string(scontext, &s, &slen) < 0)
810                 goto out;
811         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
812                 goto out;
813         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
814                 goto out;
815         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
816                   "security_compute_sid:  invalid context %s"
817                   " for scontext=%s"
818                   " tcontext=%s"
819                   " tclass=%s",
820                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
821 out:
822         kfree(s);
823         kfree(t);
824         kfree(n);
825         if (!selinux_enforcing)
826                 return 0;
827         return -EACCES;
828 }
829
830 static int security_compute_sid(u32 ssid,
831                                 u32 tsid,
832                                 u16 tclass,
833                                 u32 specified,
834                                 u32 *out_sid)
835 {
836         struct context *scontext = NULL, *tcontext = NULL, newcontext;
837         struct role_trans *roletr = NULL;
838         struct avtab_key avkey;
839         struct avtab_datum *avdatum;
840         struct avtab_node *node;
841         int rc = 0;
842
843         if (!ss_initialized) {
844                 switch (tclass) {
845                 case SECCLASS_PROCESS:
846                         *out_sid = ssid;
847                         break;
848                 default:
849                         *out_sid = tsid;
850                         break;
851                 }
852                 goto out;
853         }
854
855         context_init(&newcontext);
856
857         POLICY_RDLOCK;
858
859         scontext = sidtab_search(&sidtab, ssid);
860         if (!scontext) {
861                 printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
862                        ssid);
863                 rc = -EINVAL;
864                 goto out_unlock;
865         }
866         tcontext = sidtab_search(&sidtab, tsid);
867         if (!tcontext) {
868                 printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
869                        tsid);
870                 rc = -EINVAL;
871                 goto out_unlock;
872         }
873
874         /* Set the user identity. */
875         switch (specified) {
876         case AVTAB_TRANSITION:
877         case AVTAB_CHANGE:
878                 /* Use the process user identity. */
879                 newcontext.user = scontext->user;
880                 break;
881         case AVTAB_MEMBER:
882                 /* Use the related object owner. */
883                 newcontext.user = tcontext->user;
884                 break;
885         }
886
887         /* Set the role and type to default values. */
888         switch (tclass) {
889         case SECCLASS_PROCESS:
890                 /* Use the current role and type of process. */
891                 newcontext.role = scontext->role;
892                 newcontext.type = scontext->type;
893                 break;
894         default:
895                 /* Use the well-defined object role. */
896                 newcontext.role = OBJECT_R_VAL;
897                 /* Use the type of the related object. */
898                 newcontext.type = tcontext->type;
899         }
900
901         /* Look for a type transition/member/change rule. */
902         avkey.source_type = scontext->type;
903         avkey.target_type = tcontext->type;
904         avkey.target_class = tclass;
905         avkey.specified = specified;
906         avdatum = avtab_search(&policydb.te_avtab, &avkey);
907
908         /* If no permanent rule, also check for enabled conditional rules */
909         if(!avdatum) {
910                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
911                 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
912                         if (node->key.specified & AVTAB_ENABLED) {
913                                 avdatum = &node->datum;
914                                 break;
915                         }
916                 }
917         }
918
919         if (avdatum) {
920                 /* Use the type from the type transition/member/change rule. */
921                 newcontext.type = avdatum->data;
922         }
923
924         /* Check for class-specific changes. */
925         switch (tclass) {
926         case SECCLASS_PROCESS:
927                 if (specified & AVTAB_TRANSITION) {
928                         /* Look for a role transition rule. */
929                         for (roletr = policydb.role_tr; roletr;
930                              roletr = roletr->next) {
931                                 if (roletr->role == scontext->role &&
932                                     roletr->type == tcontext->type) {
933                                         /* Use the role transition rule. */
934                                         newcontext.role = roletr->new_role;
935                                         break;
936                                 }
937                         }
938                 }
939                 break;
940         default:
941                 break;
942         }
943
944         /* Set the MLS attributes.
945            This is done last because it may allocate memory. */
946         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
947         if (rc)
948                 goto out_unlock;
949
950         /* Check the validity of the context. */
951         if (!policydb_context_isvalid(&policydb, &newcontext)) {
952                 rc = compute_sid_handle_invalid_context(scontext,
953                                                         tcontext,
954                                                         tclass,
955                                                         &newcontext);
956                 if (rc)
957                         goto out_unlock;
958         }
959         /* Obtain the sid for the context. */
960         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
961 out_unlock:
962         POLICY_RDUNLOCK;
963         context_destroy(&newcontext);
964 out:
965         return rc;
966 }
967
968 /**
969  * security_transition_sid - Compute the SID for a new subject/object.
970  * @ssid: source security identifier
971  * @tsid: target security identifier
972  * @tclass: target security class
973  * @out_sid: security identifier for new subject/object
974  *
975  * Compute a SID to use for labeling a new subject or object in the
976  * class @tclass based on a SID pair (@ssid, @tsid).
977  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
978  * if insufficient memory is available, or %0 if the new SID was
979  * computed successfully.
980  */
981 int security_transition_sid(u32 ssid,
982                             u32 tsid,
983                             u16 tclass,
984                             u32 *out_sid)
985 {
986         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
987 }
988
989 /**
990  * security_member_sid - Compute the SID for member selection.
991  * @ssid: source security identifier
992  * @tsid: target security identifier
993  * @tclass: target security class
994  * @out_sid: security identifier for selected member
995  *
996  * Compute a SID to use when selecting a member of a polyinstantiated
997  * object of class @tclass based on a SID pair (@ssid, @tsid).
998  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
999  * if insufficient memory is available, or %0 if the SID was
1000  * computed successfully.
1001  */
1002 int security_member_sid(u32 ssid,
1003                         u32 tsid,
1004                         u16 tclass,
1005                         u32 *out_sid)
1006 {
1007         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1008 }
1009
1010 /**
1011  * security_change_sid - Compute the SID for object relabeling.
1012  * @ssid: source security identifier
1013  * @tsid: target security identifier
1014  * @tclass: target security class
1015  * @out_sid: security identifier for selected member
1016  *
1017  * Compute a SID to use for relabeling an object of class @tclass
1018  * based on a SID pair (@ssid, @tsid).
1019  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1020  * if insufficient memory is available, or %0 if the SID was
1021  * computed successfully.
1022  */
1023 int security_change_sid(u32 ssid,
1024                         u32 tsid,
1025                         u16 tclass,
1026                         u32 *out_sid)
1027 {
1028         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1029 }
1030
1031 /*
1032  * Verify that each kernel class that is defined in the
1033  * policy is correct
1034  */
1035 static int validate_classes(struct policydb *p)
1036 {
1037         int i, j;
1038         struct class_datum *cladatum;
1039         struct perm_datum *perdatum;
1040         u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1041         u16 class_val;
1042         const struct selinux_class_perm *kdefs = &selinux_class_perm;
1043         const char *def_class, *def_perm, *pol_class;
1044         struct symtab *perms;
1045
1046         for (i = 1; i < kdefs->cts_len; i++) {
1047                 def_class = kdefs->class_to_string[i];
1048                 if (i > p->p_classes.nprim) {
1049                         printk(KERN_INFO
1050                                "security:  class %s not defined in policy\n",
1051                                def_class);
1052                         continue;
1053                 }
1054                 pol_class = p->p_class_val_to_name[i-1];
1055                 if (strcmp(pol_class, def_class)) {
1056                         printk(KERN_ERR
1057                                "security:  class %d is incorrect, found %s but should be %s\n",
1058                                i, pol_class, def_class);
1059                         return -EINVAL;
1060                 }
1061         }
1062         for (i = 0; i < kdefs->av_pts_len; i++) {
1063                 class_val = kdefs->av_perm_to_string[i].tclass;
1064                 perm_val = kdefs->av_perm_to_string[i].value;
1065                 def_perm = kdefs->av_perm_to_string[i].name;
1066                 if (class_val > p->p_classes.nprim)
1067                         continue;
1068                 pol_class = p->p_class_val_to_name[class_val-1];
1069                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1070                 BUG_ON(!cladatum);
1071                 perms = &cladatum->permissions;
1072                 nprim = 1 << (perms->nprim - 1);
1073                 if (perm_val > nprim) {
1074                         printk(KERN_INFO
1075                                "security:  permission %s in class %s not defined in policy\n",
1076                                def_perm, pol_class);
1077                         continue;
1078                 }
1079                 perdatum = hashtab_search(perms->table, def_perm);
1080                 if (perdatum == NULL) {
1081                         printk(KERN_ERR
1082                                "security:  permission %s in class %s not found in policy\n",
1083                                def_perm, pol_class);
1084                         return -EINVAL;
1085                 }
1086                 pol_val = 1 << (perdatum->value - 1);
1087                 if (pol_val != perm_val) {
1088                         printk(KERN_ERR
1089                                "security:  permission %s in class %s has incorrect value\n",
1090                                def_perm, pol_class);
1091                         return -EINVAL;
1092                 }
1093         }
1094         for (i = 0; i < kdefs->av_inherit_len; i++) {
1095                 class_val = kdefs->av_inherit[i].tclass;
1096                 if (class_val > p->p_classes.nprim)
1097                         continue;
1098                 pol_class = p->p_class_val_to_name[class_val-1];
1099                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1100                 BUG_ON(!cladatum);
1101                 if (!cladatum->comdatum) {
1102                         printk(KERN_ERR
1103                                "security:  class %s should have an inherits clause but does not\n",
1104                                pol_class);
1105                         return -EINVAL;
1106                 }
1107                 tmp = kdefs->av_inherit[i].common_base;
1108                 common_pts_len = 0;
1109                 while (!(tmp & 0x01)) {
1110                         common_pts_len++;
1111                         tmp >>= 1;
1112                 }
1113                 perms = &cladatum->comdatum->permissions;
1114                 for (j = 0; j < common_pts_len; j++) {
1115                         def_perm = kdefs->av_inherit[i].common_pts[j];
1116                         if (j >= perms->nprim) {
1117                                 printk(KERN_INFO
1118                                        "security:  permission %s in class %s not defined in policy\n",
1119                                        def_perm, pol_class);
1120                                 continue;
1121                         }
1122                         perdatum = hashtab_search(perms->table, def_perm);
1123                         if (perdatum == NULL) {
1124                                 printk(KERN_ERR
1125                                        "security:  permission %s in class %s not found in policy\n",
1126                                        def_perm, pol_class);
1127                                 return -EINVAL;
1128                         }
1129                         if (perdatum->value != j + 1) {
1130                                 printk(KERN_ERR
1131                                        "security:  permission %s in class %s has incorrect value\n",
1132                                        def_perm, pol_class);
1133                                 return -EINVAL;
1134                         }
1135                 }
1136         }
1137         return 0;
1138 }
1139
1140 /* Clone the SID into the new SID table. */
1141 static int clone_sid(u32 sid,
1142                      struct context *context,
1143                      void *arg)
1144 {
1145         struct sidtab *s = arg;
1146
1147         return sidtab_insert(s, sid, context);
1148 }
1149
1150 static inline int convert_context_handle_invalid_context(struct context *context)
1151 {
1152         int rc = 0;
1153
1154         if (selinux_enforcing) {
1155                 rc = -EINVAL;
1156         } else {
1157                 char *s;
1158                 u32 len;
1159
1160                 context_struct_to_string(context, &s, &len);
1161                 printk(KERN_ERR "security:  context %s is invalid\n", s);
1162                 kfree(s);
1163         }
1164         return rc;
1165 }
1166
1167 struct convert_context_args {
1168         struct policydb *oldp;
1169         struct policydb *newp;
1170 };
1171
1172 /*
1173  * Convert the values in the security context
1174  * structure `c' from the values specified
1175  * in the policy `p->oldp' to the values specified
1176  * in the policy `p->newp'.  Verify that the
1177  * context is valid under the new policy.
1178  */
1179 static int convert_context(u32 key,
1180                            struct context *c,
1181                            void *p)
1182 {
1183         struct convert_context_args *args;
1184         struct context oldc;
1185         struct role_datum *role;
1186         struct type_datum *typdatum;
1187         struct user_datum *usrdatum;
1188         char *s;
1189         u32 len;
1190         int rc;
1191
1192         args = p;
1193
1194         rc = context_cpy(&oldc, c);
1195         if (rc)
1196                 goto out;
1197
1198         rc = -EINVAL;
1199
1200         /* Convert the user. */
1201         usrdatum = hashtab_search(args->newp->p_users.table,
1202                                   args->oldp->p_user_val_to_name[c->user - 1]);
1203         if (!usrdatum) {
1204                 goto bad;
1205         }
1206         c->user = usrdatum->value;
1207
1208         /* Convert the role. */
1209         role = hashtab_search(args->newp->p_roles.table,
1210                               args->oldp->p_role_val_to_name[c->role - 1]);
1211         if (!role) {
1212                 goto bad;
1213         }
1214         c->role = role->value;
1215
1216         /* Convert the type. */
1217         typdatum = hashtab_search(args->newp->p_types.table,
1218                                   args->oldp->p_type_val_to_name[c->type - 1]);
1219         if (!typdatum) {
1220                 goto bad;
1221         }
1222         c->type = typdatum->value;
1223
1224         rc = mls_convert_context(args->oldp, args->newp, c);
1225         if (rc)
1226                 goto bad;
1227
1228         /* Check the validity of the new context. */
1229         if (!policydb_context_isvalid(args->newp, c)) {
1230                 rc = convert_context_handle_invalid_context(&oldc);
1231                 if (rc)
1232                         goto bad;
1233         }
1234
1235         context_destroy(&oldc);
1236 out:
1237         return rc;
1238 bad:
1239         context_struct_to_string(&oldc, &s, &len);
1240         context_destroy(&oldc);
1241         printk(KERN_ERR "security:  invalidating context %s\n", s);
1242         kfree(s);
1243         goto out;
1244 }
1245
1246 extern void selinux_complete_init(void);
1247
1248 /**
1249  * security_load_policy - Load a security policy configuration.
1250  * @data: binary policy data
1251  * @len: length of data in bytes
1252  *
1253  * Load a new set of security policy configuration data,
1254  * validate it and convert the SID table as necessary.
1255  * This function will flush the access vector cache after
1256  * loading the new policy.
1257  */
1258 int security_load_policy(void *data, size_t len)
1259 {
1260         struct policydb oldpolicydb, newpolicydb;
1261         struct sidtab oldsidtab, newsidtab;
1262         struct convert_context_args args;
1263         u32 seqno;
1264         int rc = 0;
1265         struct policy_file file = { data, len }, *fp = &file;
1266
1267         LOAD_LOCK;
1268
1269         if (!ss_initialized) {
1270                 avtab_cache_init();
1271                 if (policydb_read(&policydb, fp)) {
1272                         LOAD_UNLOCK;
1273                         avtab_cache_destroy();
1274                         return -EINVAL;
1275                 }
1276                 if (policydb_load_isids(&policydb, &sidtab)) {
1277                         LOAD_UNLOCK;
1278                         policydb_destroy(&policydb);
1279                         avtab_cache_destroy();
1280                         return -EINVAL;
1281                 }
1282                 /* Verify that the kernel defined classes are correct. */
1283                 if (validate_classes(&policydb)) {
1284                         printk(KERN_ERR
1285                                "security:  the definition of a class is incorrect\n");
1286                         LOAD_UNLOCK;
1287                         sidtab_destroy(&sidtab);
1288                         policydb_destroy(&policydb);
1289                         avtab_cache_destroy();
1290                         return -EINVAL;
1291                 }
1292                 policydb_loaded_version = policydb.policyvers;
1293                 ss_initialized = 1;
1294                 seqno = ++latest_granting;
1295                 LOAD_UNLOCK;
1296                 selinux_complete_init();
1297                 avc_ss_reset(seqno);
1298                 selnl_notify_policyload(seqno);
1299                 selinux_netlbl_cache_invalidate();
1300                 return 0;
1301         }
1302
1303 #if 0
1304         sidtab_hash_eval(&sidtab, "sids");
1305 #endif
1306
1307         if (policydb_read(&newpolicydb, fp)) {
1308                 LOAD_UNLOCK;
1309                 return -EINVAL;
1310         }
1311
1312         sidtab_init(&newsidtab);
1313
1314         /* Verify that the kernel defined classes are correct. */
1315         if (validate_classes(&newpolicydb)) {
1316                 printk(KERN_ERR
1317                        "security:  the definition of a class is incorrect\n");
1318                 rc = -EINVAL;
1319                 goto err;
1320         }
1321
1322         /* Clone the SID table. */
1323         sidtab_shutdown(&sidtab);
1324         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1325                 rc = -ENOMEM;
1326                 goto err;
1327         }
1328
1329         /* Convert the internal representations of contexts
1330            in the new SID table and remove invalid SIDs. */
1331         args.oldp = &policydb;
1332         args.newp = &newpolicydb;
1333         sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1334
1335         /* Save the old policydb and SID table to free later. */
1336         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1337         sidtab_set(&oldsidtab, &sidtab);
1338
1339         /* Install the new policydb and SID table. */
1340         POLICY_WRLOCK;
1341         memcpy(&policydb, &newpolicydb, sizeof policydb);
1342         sidtab_set(&sidtab, &newsidtab);
1343         seqno = ++latest_granting;
1344         policydb_loaded_version = policydb.policyvers;
1345         POLICY_WRUNLOCK;
1346         LOAD_UNLOCK;
1347
1348         /* Free the old policydb and SID table. */
1349         policydb_destroy(&oldpolicydb);
1350         sidtab_destroy(&oldsidtab);
1351
1352         avc_ss_reset(seqno);
1353         selnl_notify_policyload(seqno);
1354         selinux_netlbl_cache_invalidate();
1355
1356         return 0;
1357
1358 err:
1359         LOAD_UNLOCK;
1360         sidtab_destroy(&newsidtab);
1361         policydb_destroy(&newpolicydb);
1362         return rc;
1363
1364 }
1365
1366 /**
1367  * security_port_sid - Obtain the SID for a port.
1368  * @domain: communication domain aka address family
1369  * @type: socket type
1370  * @protocol: protocol number
1371  * @port: port number
1372  * @out_sid: security identifier
1373  */
1374 int security_port_sid(u16 domain,
1375                       u16 type,
1376                       u8 protocol,
1377                       u16 port,
1378                       u32 *out_sid)
1379 {
1380         struct ocontext *c;
1381         int rc = 0;
1382
1383         POLICY_RDLOCK;
1384
1385         c = policydb.ocontexts[OCON_PORT];
1386         while (c) {
1387                 if (c->u.port.protocol == protocol &&
1388                     c->u.port.low_port <= port &&
1389                     c->u.port.high_port >= port)
1390                         break;
1391                 c = c->next;
1392         }
1393
1394         if (c) {
1395                 if (!c->sid[0]) {
1396                         rc = sidtab_context_to_sid(&sidtab,
1397                                                    &c->context[0],
1398                                                    &c->sid[0]);
1399                         if (rc)
1400                                 goto out;
1401                 }
1402                 *out_sid = c->sid[0];
1403         } else {
1404                 *out_sid = SECINITSID_PORT;
1405         }
1406
1407 out:
1408         POLICY_RDUNLOCK;
1409         return rc;
1410 }
1411
1412 /**
1413  * security_netif_sid - Obtain the SID for a network interface.
1414  * @name: interface name
1415  * @if_sid: interface SID
1416  * @msg_sid: default SID for received packets
1417  */
1418 int security_netif_sid(char *name,
1419                        u32 *if_sid,
1420                        u32 *msg_sid)
1421 {
1422         int rc = 0;
1423         struct ocontext *c;
1424
1425         POLICY_RDLOCK;
1426
1427         c = policydb.ocontexts[OCON_NETIF];
1428         while (c) {
1429                 if (strcmp(name, c->u.name) == 0)
1430                         break;
1431                 c = c->next;
1432         }
1433
1434         if (c) {
1435                 if (!c->sid[0] || !c->sid[1]) {
1436                         rc = sidtab_context_to_sid(&sidtab,
1437                                                   &c->context[0],
1438                                                   &c->sid[0]);
1439                         if (rc)
1440                                 goto out;
1441                         rc = sidtab_context_to_sid(&sidtab,
1442                                                    &c->context[1],
1443                                                    &c->sid[1]);
1444                         if (rc)
1445                                 goto out;
1446                 }
1447                 *if_sid = c->sid[0];
1448                 *msg_sid = c->sid[1];
1449         } else {
1450                 *if_sid = SECINITSID_NETIF;
1451                 *msg_sid = SECINITSID_NETMSG;
1452         }
1453
1454 out:
1455         POLICY_RDUNLOCK;
1456         return rc;
1457 }
1458
1459 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1460 {
1461         int i, fail = 0;
1462
1463         for(i = 0; i < 4; i++)
1464                 if(addr[i] != (input[i] & mask[i])) {
1465                         fail = 1;
1466                         break;
1467                 }
1468
1469         return !fail;
1470 }
1471
1472 /**
1473  * security_node_sid - Obtain the SID for a node (host).
1474  * @domain: communication domain aka address family
1475  * @addrp: address
1476  * @addrlen: address length in bytes
1477  * @out_sid: security identifier
1478  */
1479 int security_node_sid(u16 domain,
1480                       void *addrp,
1481                       u32 addrlen,
1482                       u32 *out_sid)
1483 {
1484         int rc = 0;
1485         struct ocontext *c;
1486
1487         POLICY_RDLOCK;
1488
1489         switch (domain) {
1490         case AF_INET: {
1491                 u32 addr;
1492
1493                 if (addrlen != sizeof(u32)) {
1494                         rc = -EINVAL;
1495                         goto out;
1496                 }
1497
1498                 addr = *((u32 *)addrp);
1499
1500                 c = policydb.ocontexts[OCON_NODE];
1501                 while (c) {
1502                         if (c->u.node.addr == (addr & c->u.node.mask))
1503                                 break;
1504                         c = c->next;
1505                 }
1506                 break;
1507         }
1508
1509         case AF_INET6:
1510                 if (addrlen != sizeof(u64) * 2) {
1511                         rc = -EINVAL;
1512                         goto out;
1513                 }
1514                 c = policydb.ocontexts[OCON_NODE6];
1515                 while (c) {
1516                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1517                                                 c->u.node6.mask))
1518                                 break;
1519                         c = c->next;
1520                 }
1521                 break;
1522
1523         default:
1524                 *out_sid = SECINITSID_NODE;
1525                 goto out;
1526         }
1527
1528         if (c) {
1529                 if (!c->sid[0]) {
1530                         rc = sidtab_context_to_sid(&sidtab,
1531                                                    &c->context[0],
1532                                                    &c->sid[0]);
1533                         if (rc)
1534                                 goto out;
1535                 }
1536                 *out_sid = c->sid[0];
1537         } else {
1538                 *out_sid = SECINITSID_NODE;
1539         }
1540
1541 out:
1542         POLICY_RDUNLOCK;
1543         return rc;
1544 }
1545
1546 #define SIDS_NEL 25
1547
1548 /**
1549  * security_get_user_sids - Obtain reachable SIDs for a user.
1550  * @fromsid: starting SID
1551  * @username: username
1552  * @sids: array of reachable SIDs for user
1553  * @nel: number of elements in @sids
1554  *
1555  * Generate the set of SIDs for legal security contexts
1556  * for a given user that can be reached by @fromsid.
1557  * Set *@sids to point to a dynamically allocated
1558  * array containing the set of SIDs.  Set *@nel to the
1559  * number of elements in the array.
1560  */
1561
1562 int security_get_user_sids(u32 fromsid,
1563                            char *username,
1564                            u32 **sids,
1565                            u32 *nel)
1566 {
1567         struct context *fromcon, usercon;
1568         u32 *mysids, *mysids2, sid;
1569         u32 mynel = 0, maxnel = SIDS_NEL;
1570         struct user_datum *user;
1571         struct role_datum *role;
1572         struct av_decision avd;
1573         struct ebitmap_node *rnode, *tnode;
1574         int rc = 0, i, j;
1575
1576         if (!ss_initialized) {
1577                 *sids = NULL;
1578                 *nel = 0;
1579                 goto out;
1580         }
1581
1582         POLICY_RDLOCK;
1583
1584         fromcon = sidtab_search(&sidtab, fromsid);
1585         if (!fromcon) {
1586                 rc = -EINVAL;
1587                 goto out_unlock;
1588         }
1589
1590         user = hashtab_search(policydb.p_users.table, username);
1591         if (!user) {
1592                 rc = -EINVAL;
1593                 goto out_unlock;
1594         }
1595         usercon.user = user->value;
1596
1597         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1598         if (!mysids) {
1599                 rc = -ENOMEM;
1600                 goto out_unlock;
1601         }
1602
1603         ebitmap_for_each_bit(&user->roles, rnode, i) {
1604                 if (!ebitmap_node_get_bit(rnode, i))
1605                         continue;
1606                 role = policydb.role_val_to_struct[i];
1607                 usercon.role = i+1;
1608                 ebitmap_for_each_bit(&role->types, tnode, j) {
1609                         if (!ebitmap_node_get_bit(tnode, j))
1610                                 continue;
1611                         usercon.type = j+1;
1612
1613                         if (mls_setup_user_range(fromcon, user, &usercon))
1614                                 continue;
1615
1616                         rc = context_struct_compute_av(fromcon, &usercon,
1617                                                        SECCLASS_PROCESS,
1618                                                        PROCESS__TRANSITION,
1619                                                        &avd);
1620                         if (rc ||  !(avd.allowed & PROCESS__TRANSITION))
1621                                 continue;
1622                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1623                         if (rc) {
1624                                 kfree(mysids);
1625                                 goto out_unlock;
1626                         }
1627                         if (mynel < maxnel) {
1628                                 mysids[mynel++] = sid;
1629                         } else {
1630                                 maxnel += SIDS_NEL;
1631                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1632                                 if (!mysids2) {
1633                                         rc = -ENOMEM;
1634                                         kfree(mysids);
1635                                         goto out_unlock;
1636                                 }
1637                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1638                                 kfree(mysids);
1639                                 mysids = mysids2;
1640                                 mysids[mynel++] = sid;
1641                         }
1642                 }
1643         }
1644
1645         *sids = mysids;
1646         *nel = mynel;
1647
1648 out_unlock:
1649         POLICY_RDUNLOCK;
1650 out:
1651         return rc;
1652 }
1653
1654 /**
1655  * security_genfs_sid - Obtain a SID for a file in a filesystem
1656  * @fstype: filesystem type
1657  * @path: path from root of mount
1658  * @sclass: file security class
1659  * @sid: SID for path
1660  *
1661  * Obtain a SID to use for a file in a filesystem that
1662  * cannot support xattr or use a fixed labeling behavior like
1663  * transition SIDs or task SIDs.
1664  */
1665 int security_genfs_sid(const char *fstype,
1666                        char *path,
1667                        u16 sclass,
1668                        u32 *sid)
1669 {
1670         int len;
1671         struct genfs *genfs;
1672         struct ocontext *c;
1673         int rc = 0, cmp = 0;
1674
1675         POLICY_RDLOCK;
1676
1677         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1678                 cmp = strcmp(fstype, genfs->fstype);
1679                 if (cmp <= 0)
1680                         break;
1681         }
1682
1683         if (!genfs || cmp) {
1684                 *sid = SECINITSID_UNLABELED;
1685                 rc = -ENOENT;
1686                 goto out;
1687         }
1688
1689         for (c = genfs->head; c; c = c->next) {
1690                 len = strlen(c->u.name);
1691                 if ((!c->v.sclass || sclass == c->v.sclass) &&
1692                     (strncmp(c->u.name, path, len) == 0))
1693                         break;
1694         }
1695
1696         if (!c) {
1697                 *sid = SECINITSID_UNLABELED;
1698                 rc = -ENOENT;
1699                 goto out;
1700         }
1701
1702         if (!c->sid[0]) {
1703                 rc = sidtab_context_to_sid(&sidtab,
1704                                            &c->context[0],
1705                                            &c->sid[0]);
1706                 if (rc)
1707                         goto out;
1708         }
1709
1710         *sid = c->sid[0];
1711 out:
1712         POLICY_RDUNLOCK;
1713         return rc;
1714 }
1715
1716 /**
1717  * security_fs_use - Determine how to handle labeling for a filesystem.
1718  * @fstype: filesystem type
1719  * @behavior: labeling behavior
1720  * @sid: SID for filesystem (superblock)
1721  */
1722 int security_fs_use(
1723         const char *fstype,
1724         unsigned int *behavior,
1725         u32 *sid)
1726 {
1727         int rc = 0;
1728         struct ocontext *c;
1729
1730         POLICY_RDLOCK;
1731
1732         c = policydb.ocontexts[OCON_FSUSE];
1733         while (c) {
1734                 if (strcmp(fstype, c->u.name) == 0)
1735                         break;
1736                 c = c->next;
1737         }
1738
1739         if (c) {
1740                 *behavior = c->v.behavior;
1741                 if (!c->sid[0]) {
1742                         rc = sidtab_context_to_sid(&sidtab,
1743                                                    &c->context[0],
1744                                                    &c->sid[0]);
1745                         if (rc)
1746                                 goto out;
1747                 }
1748                 *sid = c->sid[0];
1749         } else {
1750                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1751                 if (rc) {
1752                         *behavior = SECURITY_FS_USE_NONE;
1753                         rc = 0;
1754                 } else {
1755                         *behavior = SECURITY_FS_USE_GENFS;
1756                 }
1757         }
1758
1759 out:
1760         POLICY_RDUNLOCK;
1761         return rc;
1762 }
1763
1764 int security_get_bools(int *len, char ***names, int **values)
1765 {
1766         int i, rc = -ENOMEM;
1767
1768         POLICY_RDLOCK;
1769         *names = NULL;
1770         *values = NULL;
1771
1772         *len = policydb.p_bools.nprim;
1773         if (!*len) {
1774                 rc = 0;
1775                 goto out;
1776         }
1777
1778        *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1779         if (!*names)
1780                 goto err;
1781
1782        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1783         if (!*values)
1784                 goto err;
1785
1786         for (i = 0; i < *len; i++) {
1787                 size_t name_len;
1788                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1789                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1790                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1791                 if (!(*names)[i])
1792                         goto err;
1793                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1794                 (*names)[i][name_len - 1] = 0;
1795         }
1796         rc = 0;
1797 out:
1798         POLICY_RDUNLOCK;
1799         return rc;
1800 err:
1801         if (*names) {
1802                 for (i = 0; i < *len; i++)
1803                         kfree((*names)[i]);
1804         }
1805         kfree(*values);
1806         goto out;
1807 }
1808
1809
1810 int security_set_bools(int len, int *values)
1811 {
1812         int i, rc = 0;
1813         int lenp, seqno = 0;
1814         struct cond_node *cur;
1815
1816         POLICY_WRLOCK;
1817
1818         lenp = policydb.p_bools.nprim;
1819         if (len != lenp) {
1820                 rc = -EFAULT;
1821                 goto out;
1822         }
1823
1824         for (i = 0; i < len; i++) {
1825                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1826                         audit_log(current->audit_context, GFP_ATOMIC,
1827                                 AUDIT_MAC_CONFIG_CHANGE,
1828                                 "bool=%s val=%d old_val=%d auid=%u",
1829                                 policydb.p_bool_val_to_name[i],
1830                                 !!values[i],
1831                                 policydb.bool_val_to_struct[i]->state,
1832                                 audit_get_loginuid(current->audit_context));
1833                 }
1834                 if (values[i]) {
1835                         policydb.bool_val_to_struct[i]->state = 1;
1836                 } else {
1837                         policydb.bool_val_to_struct[i]->state = 0;
1838                 }
1839         }
1840
1841         for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1842                 rc = evaluate_cond_node(&policydb, cur);
1843                 if (rc)
1844                         goto out;
1845         }
1846
1847         seqno = ++latest_granting;
1848
1849 out:
1850         POLICY_WRUNLOCK;
1851         if (!rc) {
1852                 avc_ss_reset(seqno);
1853                 selnl_notify_policyload(seqno);
1854         }
1855         return rc;
1856 }
1857
1858 int security_get_bool_value(int bool)
1859 {
1860         int rc = 0;
1861         int len;
1862
1863         POLICY_RDLOCK;
1864
1865         len = policydb.p_bools.nprim;
1866         if (bool >= len) {
1867                 rc = -EFAULT;
1868                 goto out;
1869         }
1870
1871         rc = policydb.bool_val_to_struct[bool]->state;
1872 out:
1873         POLICY_RDUNLOCK;
1874         return rc;
1875 }
1876
1877 /*
1878  * security_sid_mls_copy() - computes a new sid based on the given
1879  * sid and the mls portion of mls_sid.
1880  */
1881 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1882 {
1883         struct context *context1;
1884         struct context *context2;
1885         struct context newcon;
1886         char *s;
1887         u32 len;
1888         int rc = 0;
1889
1890         if (!ss_initialized || !selinux_mls_enabled) {
1891                 *new_sid = sid;
1892                 goto out;
1893         }
1894
1895         context_init(&newcon);
1896
1897         POLICY_RDLOCK;
1898         context1 = sidtab_search(&sidtab, sid);
1899         if (!context1) {
1900                 printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
1901                        "%d\n", sid);
1902                 rc = -EINVAL;
1903                 goto out_unlock;
1904         }
1905
1906         context2 = sidtab_search(&sidtab, mls_sid);
1907         if (!context2) {
1908                 printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
1909                        "%d\n", mls_sid);
1910                 rc = -EINVAL;
1911                 goto out_unlock;
1912         }
1913
1914         newcon.user = context1->user;
1915         newcon.role = context1->role;
1916         newcon.type = context1->type;
1917         rc = mls_copy_context(&newcon, context2);
1918         if (rc)
1919                 goto out_unlock;
1920
1921
1922         /* Check the validity of the new context. */
1923         if (!policydb_context_isvalid(&policydb, &newcon)) {
1924                 rc = convert_context_handle_invalid_context(&newcon);
1925                 if (rc)
1926                         goto bad;
1927         }
1928
1929         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
1930         goto out_unlock;
1931
1932 bad:
1933         if (!context_struct_to_string(&newcon, &s, &len)) {
1934                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1935                           "security_sid_mls_copy: invalid context %s", s);
1936                 kfree(s);
1937         }
1938
1939 out_unlock:
1940         POLICY_RDUNLOCK;
1941         context_destroy(&newcon);
1942 out:
1943         return rc;
1944 }
1945
1946 struct selinux_audit_rule {
1947         u32 au_seqno;
1948         struct context au_ctxt;
1949 };
1950
1951 void selinux_audit_rule_free(struct selinux_audit_rule *rule)
1952 {
1953         if (rule) {
1954                 context_destroy(&rule->au_ctxt);
1955                 kfree(rule);
1956         }
1957 }
1958
1959 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
1960                             struct selinux_audit_rule **rule)
1961 {
1962         struct selinux_audit_rule *tmprule;
1963         struct role_datum *roledatum;
1964         struct type_datum *typedatum;
1965         struct user_datum *userdatum;
1966         int rc = 0;
1967
1968         *rule = NULL;
1969
1970         if (!ss_initialized)
1971                 return -ENOTSUPP;
1972
1973         switch (field) {
1974         case AUDIT_SUBJ_USER:
1975         case AUDIT_SUBJ_ROLE:
1976         case AUDIT_SUBJ_TYPE:
1977         case AUDIT_OBJ_USER:
1978         case AUDIT_OBJ_ROLE:
1979         case AUDIT_OBJ_TYPE:
1980                 /* only 'equals' and 'not equals' fit user, role, and type */
1981                 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
1982                         return -EINVAL;
1983                 break;
1984         case AUDIT_SUBJ_SEN:
1985         case AUDIT_SUBJ_CLR:
1986         case AUDIT_OBJ_LEV_LOW:
1987         case AUDIT_OBJ_LEV_HIGH:
1988                 /* we do not allow a range, indicated by the presense of '-' */
1989                 if (strchr(rulestr, '-'))
1990                         return -EINVAL;
1991                 break;
1992         default:
1993                 /* only the above fields are valid */
1994                 return -EINVAL;
1995         }
1996
1997         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
1998         if (!tmprule)
1999                 return -ENOMEM;
2000
2001         context_init(&tmprule->au_ctxt);
2002
2003         POLICY_RDLOCK;
2004
2005         tmprule->au_seqno = latest_granting;
2006
2007         switch (field) {
2008         case AUDIT_SUBJ_USER:
2009         case AUDIT_OBJ_USER:
2010                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2011                 if (!userdatum)
2012                         rc = -EINVAL;
2013                 else
2014                         tmprule->au_ctxt.user = userdatum->value;
2015                 break;
2016         case AUDIT_SUBJ_ROLE:
2017         case AUDIT_OBJ_ROLE:
2018                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2019                 if (!roledatum)
2020                         rc = -EINVAL;
2021                 else
2022                         tmprule->au_ctxt.role = roledatum->value;
2023                 break;
2024         case AUDIT_SUBJ_TYPE:
2025         case AUDIT_OBJ_TYPE:
2026                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2027                 if (!typedatum)
2028                         rc = -EINVAL;
2029                 else
2030                         tmprule->au_ctxt.type = typedatum->value;
2031                 break;
2032         case AUDIT_SUBJ_SEN:
2033         case AUDIT_SUBJ_CLR:
2034         case AUDIT_OBJ_LEV_LOW:
2035         case AUDIT_OBJ_LEV_HIGH:
2036                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2037                 break;
2038         }
2039
2040         POLICY_RDUNLOCK;
2041
2042         if (rc) {
2043                 selinux_audit_rule_free(tmprule);
2044                 tmprule = NULL;
2045         }
2046
2047         *rule = tmprule;
2048
2049         return rc;
2050 }
2051
2052 int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2053                              struct selinux_audit_rule *rule,
2054                              struct audit_context *actx)
2055 {
2056         struct context *ctxt;
2057         struct mls_level *level;
2058         int match = 0;
2059
2060         if (!rule) {
2061                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2062                           "selinux_audit_rule_match: missing rule\n");
2063                 return -ENOENT;
2064         }
2065
2066         POLICY_RDLOCK;
2067
2068         if (rule->au_seqno < latest_granting) {
2069                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2070                           "selinux_audit_rule_match: stale rule\n");
2071                 match = -ESTALE;
2072                 goto out;
2073         }
2074
2075         ctxt = sidtab_search(&sidtab, sid);
2076         if (!ctxt) {
2077                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2078                           "selinux_audit_rule_match: unrecognized SID %d\n",
2079                           sid);
2080                 match = -ENOENT;
2081                 goto out;
2082         }
2083
2084         /* a field/op pair that is not caught here will simply fall through
2085            without a match */
2086         switch (field) {
2087         case AUDIT_SUBJ_USER:
2088         case AUDIT_OBJ_USER:
2089                 switch (op) {
2090                 case AUDIT_EQUAL:
2091                         match = (ctxt->user == rule->au_ctxt.user);
2092                         break;
2093                 case AUDIT_NOT_EQUAL:
2094                         match = (ctxt->user != rule->au_ctxt.user);
2095                         break;
2096                 }
2097                 break;
2098         case AUDIT_SUBJ_ROLE:
2099         case AUDIT_OBJ_ROLE:
2100                 switch (op) {
2101                 case AUDIT_EQUAL:
2102                         match = (ctxt->role == rule->au_ctxt.role);
2103                         break;
2104                 case AUDIT_NOT_EQUAL:
2105                         match = (ctxt->role != rule->au_ctxt.role);
2106                         break;
2107                 }
2108                 break;
2109         case AUDIT_SUBJ_TYPE:
2110         case AUDIT_OBJ_TYPE:
2111                 switch (op) {
2112                 case AUDIT_EQUAL:
2113                         match = (ctxt->type == rule->au_ctxt.type);
2114                         break;
2115                 case AUDIT_NOT_EQUAL:
2116                         match = (ctxt->type != rule->au_ctxt.type);
2117                         break;
2118                 }
2119                 break;
2120         case AUDIT_SUBJ_SEN:
2121         case AUDIT_SUBJ_CLR:
2122         case AUDIT_OBJ_LEV_LOW:
2123         case AUDIT_OBJ_LEV_HIGH:
2124                 level = ((field == AUDIT_SUBJ_SEN ||
2125                           field == AUDIT_OBJ_LEV_LOW) ?
2126                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2127                 switch (op) {
2128                 case AUDIT_EQUAL:
2129                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2130                                              level);
2131                         break;
2132                 case AUDIT_NOT_EQUAL:
2133                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2134                                               level);
2135                         break;
2136                 case AUDIT_LESS_THAN:
2137                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2138                                                level) &&
2139                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2140                                                level));
2141                         break;
2142                 case AUDIT_LESS_THAN_OR_EQUAL:
2143                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2144                                               level);
2145                         break;
2146                 case AUDIT_GREATER_THAN:
2147                         match = (mls_level_dom(level,
2148                                               &rule->au_ctxt.range.level[0]) &&
2149                                  !mls_level_eq(level,
2150                                                &rule->au_ctxt.range.level[0]));
2151                         break;
2152                 case AUDIT_GREATER_THAN_OR_EQUAL:
2153                         match = mls_level_dom(level,
2154                                               &rule->au_ctxt.range.level[0]);
2155                         break;
2156                 }
2157         }
2158
2159 out:
2160         POLICY_RDUNLOCK;
2161         return match;
2162 }
2163
2164 static int (*aurule_callback)(void) = NULL;
2165
2166 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2167                                u16 class, u32 perms, u32 *retained)
2168 {
2169         int err = 0;
2170
2171         if (event == AVC_CALLBACK_RESET && aurule_callback)
2172                 err = aurule_callback();
2173         return err;
2174 }
2175
2176 static int __init aurule_init(void)
2177 {
2178         int err;
2179
2180         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2181                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2182         if (err)
2183                 panic("avc_add_callback() failed, error %d\n", err);
2184
2185         return err;
2186 }
2187 __initcall(aurule_init);
2188
2189 void selinux_audit_set_callback(int (*callback)(void))
2190 {
2191         aurule_callback = callback;
2192 }
2193
2194 #ifdef CONFIG_NETLABEL
2195 /*
2196  * This is the structure we store inside the NetLabel cache block.
2197  */
2198 #define NETLBL_CACHE(x)           ((struct netlbl_cache *)(x))
2199 #define NETLBL_CACHE_T_NONE       0
2200 #define NETLBL_CACHE_T_SID        1
2201 #define NETLBL_CACHE_T_MLS        2
2202 struct netlbl_cache {
2203         u32 type;
2204         union {
2205                 u32 sid;
2206                 struct mls_range mls_label;
2207         } data;
2208 };
2209
2210 /**
2211  * selinux_netlbl_cache_free - Free the NetLabel cached data
2212  * @data: the data to free
2213  *
2214  * Description:
2215  * This function is intended to be used as the free() callback inside the
2216  * netlbl_lsm_cache structure.
2217  *
2218  */
2219 static void selinux_netlbl_cache_free(const void *data)
2220 {
2221         struct netlbl_cache *cache;
2222
2223         if (data == NULL)
2224                 return;
2225
2226         cache = NETLBL_CACHE(data);
2227         switch (cache->type) {
2228         case NETLBL_CACHE_T_MLS:
2229                 ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2230                 break;
2231         }
2232         kfree(data);
2233 }
2234
2235 /**
2236  * selinux_netlbl_cache_add - Add an entry to the NetLabel cache
2237  * @skb: the packet
2238  * @ctx: the SELinux context
2239  *
2240  * Description:
2241  * Attempt to cache the context in @ctx, which was derived from the packet in
2242  * @skb, in the NetLabel subsystem cache.
2243  *
2244  */
2245 static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx)
2246 {
2247         struct netlbl_cache *cache = NULL;
2248         struct netlbl_lsm_secattr secattr;
2249
2250         netlbl_secattr_init(&secattr);
2251         secattr.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2252         if (secattr.cache == NULL)
2253                 goto netlbl_cache_add_return;
2254
2255         cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2256         if (cache == NULL)
2257                 goto netlbl_cache_add_return;
2258
2259         cache->type = NETLBL_CACHE_T_MLS;
2260         if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2261                         &ctx->range.level[0].cat) != 0)
2262                 goto netlbl_cache_add_return;
2263         cache->data.mls_label.level[1].cat.highbit =
2264                 cache->data.mls_label.level[0].cat.highbit;
2265         cache->data.mls_label.level[1].cat.node =
2266                 cache->data.mls_label.level[0].cat.node;
2267         cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2268         cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2269
2270         secattr.cache->free = selinux_netlbl_cache_free;
2271         secattr.cache->data = (void *)cache;
2272         secattr.flags = NETLBL_SECATTR_CACHE;
2273
2274         netlbl_cache_add(skb, &secattr);
2275
2276 netlbl_cache_add_return:
2277         netlbl_secattr_destroy(&secattr);
2278 }
2279
2280 /**
2281  * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache
2282  *
2283  * Description:
2284  * Invalidate the NetLabel security attribute mapping cache.
2285  *
2286  */
2287 void selinux_netlbl_cache_invalidate(void)
2288 {
2289         netlbl_cache_invalidate();
2290 }
2291
2292 /**
2293  * selinux_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2294  * @skb: the network packet
2295  * @secattr: the NetLabel packet security attributes
2296  * @base_sid: the SELinux SID to use as a context for MLS only attributes
2297  * @sid: the SELinux SID
2298  *
2299  * Description:
2300  * Convert the given NetLabel packet security attributes in @secattr into a
2301  * SELinux SID.  If the @secattr field does not contain a full SELinux
2302  * SID/context then use the context in @base_sid as the foundation.  If @skb
2303  * is not NULL attempt to cache as much data as possibile.  Returns zero on
2304  * success, negative values on failure.
2305  *
2306  */
2307 static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb,
2308                                          struct netlbl_lsm_secattr *secattr,
2309                                          u32 base_sid,
2310                                          u32 *sid)
2311 {
2312         int rc = -EIDRM;
2313         struct context *ctx;
2314         struct context ctx_new;
2315         struct netlbl_cache *cache;
2316
2317         POLICY_RDLOCK;
2318
2319         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2320                 cache = NETLBL_CACHE(secattr->cache->data);
2321                 switch (cache->type) {
2322                 case NETLBL_CACHE_T_SID:
2323                         *sid = cache->data.sid;
2324                         rc = 0;
2325                         break;
2326                 case NETLBL_CACHE_T_MLS:
2327                         ctx = sidtab_search(&sidtab, base_sid);
2328                         if (ctx == NULL)
2329                                 goto netlbl_secattr_to_sid_return;
2330
2331                         ctx_new.user = ctx->user;
2332                         ctx_new.role = ctx->role;
2333                         ctx_new.type = ctx->type;
2334                         ctx_new.range.level[0].sens =
2335                                 cache->data.mls_label.level[0].sens;
2336                         ctx_new.range.level[0].cat.highbit =
2337                                 cache->data.mls_label.level[0].cat.highbit;
2338                         ctx_new.range.level[0].cat.node =
2339                                 cache->data.mls_label.level[0].cat.node;
2340                         ctx_new.range.level[1].sens =
2341                                 cache->data.mls_label.level[1].sens;
2342                         ctx_new.range.level[1].cat.highbit =
2343                                 cache->data.mls_label.level[1].cat.highbit;
2344                         ctx_new.range.level[1].cat.node =
2345                                 cache->data.mls_label.level[1].cat.node;
2346
2347                         rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2348                         break;
2349                 default:
2350                         goto netlbl_secattr_to_sid_return;
2351                 }
2352         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2353                 ctx = sidtab_search(&sidtab, base_sid);
2354                 if (ctx == NULL)
2355                         goto netlbl_secattr_to_sid_return;
2356
2357                 ctx_new.user = ctx->user;
2358                 ctx_new.role = ctx->role;
2359                 ctx_new.type = ctx->type;
2360                 mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl);
2361                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2362                         if (mls_import_cat(&ctx_new,
2363                                            secattr->mls_cat,
2364                                            secattr->mls_cat_len,
2365                                            NULL,
2366                                            0) != 0)
2367                                 goto netlbl_secattr_to_sid_return;
2368                         ctx_new.range.level[1].cat.highbit =
2369                                 ctx_new.range.level[0].cat.highbit;
2370                         ctx_new.range.level[1].cat.node =
2371                                 ctx_new.range.level[0].cat.node;
2372                 } else {
2373                         ebitmap_init(&ctx_new.range.level[0].cat);
2374                         ebitmap_init(&ctx_new.range.level[1].cat);
2375                 }
2376                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2377                         goto netlbl_secattr_to_sid_return_cleanup;
2378
2379                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2380                 if (rc != 0)
2381                         goto netlbl_secattr_to_sid_return_cleanup;
2382
2383                 if (skb != NULL)
2384                         selinux_netlbl_cache_add(skb, &ctx_new);
2385                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2386         } else {
2387                 *sid = SECSID_NULL;
2388                 rc = 0;
2389         }
2390
2391 netlbl_secattr_to_sid_return:
2392         POLICY_RDUNLOCK;
2393         return rc;
2394 netlbl_secattr_to_sid_return_cleanup:
2395         ebitmap_destroy(&ctx_new.range.level[0].cat);
2396         goto netlbl_secattr_to_sid_return;
2397 }
2398
2399 /**
2400  * selinux_netlbl_skbuff_getsid - Get the sid of a packet using NetLabel
2401  * @skb: the packet
2402  * @base_sid: the SELinux SID to use as a context for MLS only attributes
2403  * @sid: the SID
2404  *
2405  * Description:
2406  * Call the NetLabel mechanism to get the security attributes of the given
2407  * packet and use those attributes to determine the correct context/SID to
2408  * assign to the packet.  Returns zero on success, negative values on failure.
2409  *
2410  */
2411 static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
2412                                         u32 base_sid,
2413                                         u32 *sid)
2414 {
2415         int rc;
2416         struct netlbl_lsm_secattr secattr;
2417
2418         netlbl_secattr_init(&secattr);
2419         rc = netlbl_skbuff_getattr(skb, &secattr);
2420         if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2421                 rc = selinux_netlbl_secattr_to_sid(skb,
2422                                                    &secattr,
2423                                                    base_sid,
2424                                                    sid);
2425         else
2426                 *sid = SECSID_NULL;
2427         netlbl_secattr_destroy(&secattr);
2428
2429         return rc;
2430 }
2431
2432 /**
2433  * selinux_netlbl_socket_setsid - Label a socket using the NetLabel mechanism
2434  * @sock: the socket to label
2435  * @sid: the SID to use
2436  *
2437  * Description:
2438  * Attempt to label a socket using the NetLabel mechanism using the given
2439  * SID.  Returns zero values on success, negative values on failure.  The
2440  * caller is responsibile for calling rcu_read_lock() before calling this
2441  * this function and rcu_read_unlock() after this function returns.
2442  *
2443  */
2444 static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
2445 {
2446         int rc = -ENOENT;
2447         struct sk_security_struct *sksec = sock->sk->sk_security;
2448         struct netlbl_lsm_secattr secattr;
2449         struct context *ctx;
2450
2451         if (!ss_initialized)
2452                 return 0;
2453
2454         netlbl_secattr_init(&secattr);
2455
2456         POLICY_RDLOCK;
2457
2458         ctx = sidtab_search(&sidtab, sid);
2459         if (ctx == NULL)
2460                 goto netlbl_socket_setsid_return;
2461
2462         secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2463                                  GFP_ATOMIC);
2464         mls_export_lvl(ctx, &secattr.mls_lvl, NULL);
2465         rc = mls_export_cat(ctx,
2466                             &secattr.mls_cat,
2467                             &secattr.mls_cat_len,
2468                             NULL,
2469                             NULL);
2470         if (rc != 0)
2471                 goto netlbl_socket_setsid_return;
2472
2473         secattr.flags |= NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
2474         if (secattr.mls_cat)
2475                 secattr.flags |= NETLBL_SECATTR_MLS_CAT;
2476
2477         rc = netlbl_socket_setattr(sock, &secattr);
2478         if (rc == 0) {
2479                 spin_lock(&sksec->nlbl_lock);
2480                 sksec->nlbl_state = NLBL_LABELED;
2481                 spin_unlock(&sksec->nlbl_lock);
2482         }
2483
2484 netlbl_socket_setsid_return:
2485         POLICY_RDUNLOCK;
2486         netlbl_secattr_destroy(&secattr);
2487         return rc;
2488 }
2489
2490 /**
2491  * selinux_netlbl_sk_security_reset - Reset the NetLabel fields
2492  * @ssec: the sk_security_struct
2493  * @family: the socket family
2494  *
2495  * Description:
2496  * Called when the NetLabel state of a sk_security_struct needs to be reset.
2497  * The caller is responsibile for all the NetLabel sk_security_struct locking.
2498  *
2499  */
2500 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
2501                                       int family)
2502 {
2503         if (family == PF_INET)
2504                 ssec->nlbl_state = NLBL_REQUIRE;
2505         else
2506                 ssec->nlbl_state = NLBL_UNSET;
2507 }
2508
2509 /**
2510  * selinux_netlbl_sk_security_init - Setup the NetLabel fields
2511  * @ssec: the sk_security_struct
2512  * @family: the socket family
2513  *
2514  * Description:
2515  * Called when a new sk_security_struct is allocated to initialize the NetLabel
2516  * fields.
2517  *
2518  */
2519 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
2520                                      int family)
2521 {
2522         /* No locking needed, we are the only one who has access to ssec */
2523         selinux_netlbl_sk_security_reset(ssec, family);
2524         spin_lock_init(&ssec->nlbl_lock);
2525 }
2526
2527 /**
2528  * selinux_netlbl_sk_security_clone - Copy the NetLabel fields
2529  * @ssec: the original sk_security_struct
2530  * @newssec: the cloned sk_security_struct
2531  *
2532  * Description:
2533  * Clone the NetLabel specific sk_security_struct fields from @ssec to
2534  * @newssec.
2535  *
2536  */
2537 void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
2538                                       struct sk_security_struct *newssec)
2539 {
2540         /* We don't need to take newssec->nlbl_lock because we are the only
2541          * thread with access to newssec, but we do need to take the RCU read
2542          * lock as other threads could have access to ssec */
2543         rcu_read_lock();
2544         selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
2545         newssec->sclass = ssec->sclass;
2546         rcu_read_unlock();
2547 }
2548
2549 /**
2550  * selinux_netlbl_socket_post_create - Label a socket using NetLabel
2551  * @sock: the socket to label
2552  *
2553  * Description:
2554  * Attempt to label a socket using the NetLabel mechanism using the given
2555  * SID.  Returns zero values on success, negative values on failure.
2556  *
2557  */
2558 int selinux_netlbl_socket_post_create(struct socket *sock)
2559 {
2560         int rc = 0;
2561         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2562         struct sk_security_struct *sksec = sock->sk->sk_security;
2563
2564         sksec->sclass = isec->sclass;
2565
2566         rcu_read_lock();
2567         if (sksec->nlbl_state == NLBL_REQUIRE)
2568                 rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2569         rcu_read_unlock();
2570
2571         return rc;
2572 }
2573
2574 /**
2575  * selinux_netlbl_sock_graft - Netlabel the new socket
2576  * @sk: the new connection
2577  * @sock: the new socket
2578  *
2579  * Description:
2580  * The connection represented by @sk is being grafted onto @sock so set the
2581  * socket's NetLabel to match the SID of @sk.
2582  *
2583  */
2584 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
2585 {
2586         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
2587         struct sk_security_struct *sksec = sk->sk_security;
2588         struct netlbl_lsm_secattr secattr;
2589         u32 nlbl_peer_sid;
2590
2591         sksec->sclass = isec->sclass;
2592
2593         rcu_read_lock();
2594
2595         if (sksec->nlbl_state != NLBL_REQUIRE) {
2596                 rcu_read_unlock();
2597                 return;
2598         }
2599
2600         netlbl_secattr_init(&secattr);
2601         if (netlbl_sock_getattr(sk, &secattr) == 0 &&
2602             secattr.flags != NETLBL_SECATTR_NONE &&
2603             selinux_netlbl_secattr_to_sid(NULL,
2604                                           &secattr,
2605                                           SECINITSID_UNLABELED,
2606                                           &nlbl_peer_sid) == 0)
2607                 sksec->peer_sid = nlbl_peer_sid;
2608         netlbl_secattr_destroy(&secattr);
2609
2610         /* Try to set the NetLabel on the socket to save time later, if we fail
2611          * here we will pick up the pieces in later calls to
2612          * selinux_netlbl_inode_permission(). */
2613         selinux_netlbl_socket_setsid(sock, sksec->sid);
2614
2615         rcu_read_unlock();
2616 }
2617
2618 /**
2619  * selinux_netlbl_inet_conn_request - Handle a new connection request
2620  * @skb: the packet
2621  * @sock_sid: the SID of the parent socket
2622  *
2623  * Description:
2624  * If present, use the security attributes of the packet in @skb and the
2625  * parent sock's SID to arrive at a SID for the new child sock.  Returns the
2626  * SID of the connection or SECSID_NULL on failure.
2627  *
2628  */
2629 u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid)
2630 {
2631         int rc;
2632         u32 peer_sid;
2633
2634         rc = selinux_netlbl_skbuff_getsid(skb, sock_sid, &peer_sid);
2635         if (rc != 0)
2636                 return SECSID_NULL;
2637
2638         return peer_sid;
2639 }
2640
2641 /**
2642  * selinux_netlbl_inode_permission - Verify the socket is NetLabel labeled
2643  * @inode: the file descriptor's inode
2644  * @mask: the permission mask
2645  *
2646  * Description:
2647  * Looks at a file's inode and if it is marked as a socket protected by
2648  * NetLabel then verify that the socket has been labeled, if not try to label
2649  * the socket now with the inode's SID.  Returns zero on success, negative
2650  * values on failure.
2651  *
2652  */
2653 int selinux_netlbl_inode_permission(struct inode *inode, int mask)
2654 {
2655         int rc;
2656         struct sk_security_struct *sksec;
2657         struct socket *sock;
2658
2659         if (!S_ISSOCK(inode->i_mode) ||
2660             ((mask & (MAY_WRITE | MAY_APPEND)) == 0))
2661                 return 0;
2662         sock = SOCKET_I(inode);
2663         sksec = sock->sk->sk_security;
2664
2665         rcu_read_lock();
2666         if (sksec->nlbl_state != NLBL_REQUIRE) {
2667                 rcu_read_unlock();
2668                 return 0;
2669         }
2670         lock_sock(sock->sk);
2671         rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
2672         release_sock(sock->sk);
2673         rcu_read_unlock();
2674
2675         return rc;
2676 }
2677
2678 /**
2679  * selinux_netlbl_sock_rcv_skb - Do an inbound access check using NetLabel
2680  * @sksec: the sock's sk_security_struct
2681  * @skb: the packet
2682  * @ad: the audit data
2683  *
2684  * Description:
2685  * Fetch the NetLabel security attributes from @skb and perform an access check
2686  * against the receiving socket.  Returns zero on success, negative values on
2687  * error.
2688  *
2689  */
2690 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
2691                                 struct sk_buff *skb,
2692                                 struct avc_audit_data *ad)
2693 {
2694         int rc;
2695         u32 netlbl_sid;
2696         u32 recv_perm;
2697
2698         rc = selinux_netlbl_skbuff_getsid(skb,
2699                                           SECINITSID_UNLABELED,
2700                                           &netlbl_sid);
2701         if (rc != 0)
2702                 return rc;
2703
2704         if (netlbl_sid == SECSID_NULL)
2705                 return 0;
2706
2707         switch (sksec->sclass) {
2708         case SECCLASS_UDP_SOCKET:
2709                 recv_perm = UDP_SOCKET__RECVFROM;
2710                 break;
2711         case SECCLASS_TCP_SOCKET:
2712                 recv_perm = TCP_SOCKET__RECVFROM;
2713                 break;
2714         default:
2715                 recv_perm = RAWIP_SOCKET__RECVFROM;
2716         }
2717
2718         rc = avc_has_perm(sksec->sid,
2719                           netlbl_sid,
2720                           sksec->sclass,
2721                           recv_perm,
2722                           ad);
2723         if (rc == 0)
2724                 return 0;
2725
2726         netlbl_skbuff_err(skb, rc);
2727         return rc;
2728 }
2729
2730 /**
2731  * selinux_netlbl_socket_getpeersec_stream - Return the connected peer's SID
2732  * @sock: the socket
2733  *
2734  * Description:
2735  * Examine @sock to find the connected peer's SID.  Returns the SID on success
2736  * or SECSID_NULL on error.
2737  *
2738  */
2739 u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
2740 {
2741         struct sk_security_struct *sksec = sock->sk->sk_security;
2742         return sksec->peer_sid;
2743 }
2744
2745 /**
2746  * selinux_netlbl_socket_getpeersec_dgram - Return the SID of a NetLabel packet
2747  * @skb: the packet
2748  *
2749  * Description:
2750  * Examine @skb to find the SID assigned to it by NetLabel.  Returns the SID on
2751  * success, SECSID_NULL on error.
2752  *
2753  */
2754 u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
2755 {
2756         int peer_sid;
2757
2758         if (selinux_netlbl_skbuff_getsid(skb,
2759                                          SECINITSID_UNLABELED,
2760                                          &peer_sid) != 0)
2761                 return SECSID_NULL;
2762
2763         return peer_sid;
2764 }
2765
2766 /**
2767  * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel
2768  * @sock: the socket
2769  * @level: the socket level or protocol
2770  * @optname: the socket option name
2771  *
2772  * Description:
2773  * Check the setsockopt() call and if the user is trying to replace the IP
2774  * options on a socket and a NetLabel is in place for the socket deny the
2775  * access; otherwise allow the access.  Returns zero when the access is
2776  * allowed, -EACCES when denied, and other negative values on error.
2777  *
2778  */
2779 int selinux_netlbl_socket_setsockopt(struct socket *sock,
2780                                      int level,
2781                                      int optname)
2782 {
2783         int rc = 0;
2784         struct sk_security_struct *sksec = sock->sk->sk_security;
2785         struct netlbl_lsm_secattr secattr;
2786
2787         rcu_read_lock();
2788         if (level == IPPROTO_IP && optname == IP_OPTIONS &&
2789             sksec->nlbl_state == NLBL_LABELED) {
2790                 netlbl_secattr_init(&secattr);
2791                 rc = netlbl_socket_getattr(sock, &secattr);
2792                 if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
2793                         rc = -EACCES;
2794                 netlbl_secattr_destroy(&secattr);
2795         }
2796         rcu_read_unlock();
2797
2798         return rc;
2799 }
2800 #endif /* CONFIG_NETLABEL */