selinux: allow MLS->non-MLS and vice versa upon policy reload
[linux-2.6.git] / security / selinux / ss / services.c
1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5  *           James Morris <jmorris@redhat.com>
6  *
7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8  *
9  *      Support for enhanced MLS infrastructure.
10  *      Support for context based audit filters.
11  *
12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  *      Added conditional policy language extensions
15  *
16  * Updated: Hewlett-Packard <paul.moore@hp.com>
17  *
18  *      Added support for NetLabel
19  *      Added support for the policy capability bitmap
20  *
21  * Updated: Chad Sellers <csellers@tresys.com>
22  *
23  *  Added validation of kernel classes and permissions
24  *
25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26  *
27  *  Added support for bounds domain and audit messaged on masked permissions
28  *
29  * Updated: Guido Trentalancia <guido@trentalancia.com>
30  *
31  *  Added support for runtime switching of the policy type
32  *
33  * Copyright (C) 2008, 2009 NEC Corporation
34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
38  *      This program is free software; you can redistribute it and/or modify
39  *      it under the terms of the GNU General Public License as published by
40  *      the Free Software Foundation, version 2.
41  */
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/string.h>
45 #include <linux/spinlock.h>
46 #include <linux/rcupdate.h>
47 #include <linux/errno.h>
48 #include <linux/in.h>
49 #include <linux/sched.h>
50 #include <linux/audit.h>
51 #include <linux/mutex.h>
52 #include <linux/selinux.h>
53 #include <net/netlabel.h>
54
55 #include "flask.h"
56 #include "avc.h"
57 #include "avc_ss.h"
58 #include "security.h"
59 #include "context.h"
60 #include "policydb.h"
61 #include "sidtab.h"
62 #include "services.h"
63 #include "conditional.h"
64 #include "mls.h"
65 #include "objsec.h"
66 #include "netlabel.h"
67 #include "xfrm.h"
68 #include "ebitmap.h"
69 #include "audit.h"
70
71 extern void selnl_notify_policyload(u32 seqno);
72
73 int selinux_policycap_netpeer;
74 int selinux_policycap_openperm;
75
76 static DEFINE_RWLOCK(policy_rwlock);
77
78 static struct sidtab sidtab;
79 struct policydb policydb;
80 int ss_initialized;
81
82 /*
83  * The largest sequence number that has been used when
84  * providing an access decision to the access vector cache.
85  * The sequence number only changes when a policy change
86  * occurs.
87  */
88 static u32 latest_granting;
89
90 /* Forward declaration. */
91 static int context_struct_to_string(struct context *context, char **scontext,
92                                     u32 *scontext_len);
93
94 static void context_struct_compute_av(struct context *scontext,
95                                       struct context *tcontext,
96                                       u16 tclass,
97                                       struct av_decision *avd);
98
99 struct selinux_mapping {
100         u16 value; /* policy value */
101         unsigned num_perms;
102         u32 perms[sizeof(u32) * 8];
103 };
104
105 static struct selinux_mapping *current_mapping;
106 static u16 current_mapping_size;
107
108 static int selinux_set_mapping(struct policydb *pol,
109                                struct security_class_mapping *map,
110                                struct selinux_mapping **out_map_p,
111                                u16 *out_map_size)
112 {
113         struct selinux_mapping *out_map = NULL;
114         size_t size = sizeof(struct selinux_mapping);
115         u16 i, j;
116         unsigned k;
117         bool print_unknown_handle = false;
118
119         /* Find number of classes in the input mapping */
120         if (!map)
121                 return -EINVAL;
122         i = 0;
123         while (map[i].name)
124                 i++;
125
126         /* Allocate space for the class records, plus one for class zero */
127         out_map = kcalloc(++i, size, GFP_ATOMIC);
128         if (!out_map)
129                 return -ENOMEM;
130
131         /* Store the raw class and permission values */
132         j = 0;
133         while (map[j].name) {
134                 struct security_class_mapping *p_in = map + (j++);
135                 struct selinux_mapping *p_out = out_map + j;
136
137                 /* An empty class string skips ahead */
138                 if (!strcmp(p_in->name, "")) {
139                         p_out->num_perms = 0;
140                         continue;
141                 }
142
143                 p_out->value = string_to_security_class(pol, p_in->name);
144                 if (!p_out->value) {
145                         printk(KERN_INFO
146                                "SELinux:  Class %s not defined in policy.\n",
147                                p_in->name);
148                         if (pol->reject_unknown)
149                                 goto err;
150                         p_out->num_perms = 0;
151                         print_unknown_handle = true;
152                         continue;
153                 }
154
155                 k = 0;
156                 while (p_in->perms && p_in->perms[k]) {
157                         /* An empty permission string skips ahead */
158                         if (!*p_in->perms[k]) {
159                                 k++;
160                                 continue;
161                         }
162                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
163                                                             p_in->perms[k]);
164                         if (!p_out->perms[k]) {
165                                 printk(KERN_INFO
166                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
167                                        p_in->perms[k], p_in->name);
168                                 if (pol->reject_unknown)
169                                         goto err;
170                                 print_unknown_handle = true;
171                         }
172
173                         k++;
174                 }
175                 p_out->num_perms = k;
176         }
177
178         if (print_unknown_handle)
179                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
180                        pol->allow_unknown ? "allowed" : "denied");
181
182         *out_map_p = out_map;
183         *out_map_size = i;
184         return 0;
185 err:
186         kfree(out_map);
187         return -EINVAL;
188 }
189
190 /*
191  * Get real, policy values from mapped values
192  */
193
194 static u16 unmap_class(u16 tclass)
195 {
196         if (tclass < current_mapping_size)
197                 return current_mapping[tclass].value;
198
199         return tclass;
200 }
201
202 static void map_decision(u16 tclass, struct av_decision *avd,
203                          int allow_unknown)
204 {
205         if (tclass < current_mapping_size) {
206                 unsigned i, n = current_mapping[tclass].num_perms;
207                 u32 result;
208
209                 for (i = 0, result = 0; i < n; i++) {
210                         if (avd->allowed & current_mapping[tclass].perms[i])
211                                 result |= 1<<i;
212                         if (allow_unknown && !current_mapping[tclass].perms[i])
213                                 result |= 1<<i;
214                 }
215                 avd->allowed = result;
216
217                 for (i = 0, result = 0; i < n; i++)
218                         if (avd->auditallow & current_mapping[tclass].perms[i])
219                                 result |= 1<<i;
220                 avd->auditallow = result;
221
222                 for (i = 0, result = 0; i < n; i++) {
223                         if (avd->auditdeny & current_mapping[tclass].perms[i])
224                                 result |= 1<<i;
225                         if (!allow_unknown && !current_mapping[tclass].perms[i])
226                                 result |= 1<<i;
227                 }
228                 /*
229                  * In case the kernel has a bug and requests a permission
230                  * between num_perms and the maximum permission number, we
231                  * should audit that denial
232                  */
233                 for (; i < (sizeof(u32)*8); i++)
234                         result |= 1<<i;
235                 avd->auditdeny = result;
236         }
237 }
238
239 int security_mls_enabled(void)
240 {
241         return policydb.mls_enabled;
242 }
243
244 /*
245  * Return the boolean value of a constraint expression
246  * when it is applied to the specified source and target
247  * security contexts.
248  *
249  * xcontext is a special beast...  It is used by the validatetrans rules
250  * only.  For these rules, scontext is the context before the transition,
251  * tcontext is the context after the transition, and xcontext is the context
252  * of the process performing the transition.  All other callers of
253  * constraint_expr_eval should pass in NULL for xcontext.
254  */
255 static int constraint_expr_eval(struct context *scontext,
256                                 struct context *tcontext,
257                                 struct context *xcontext,
258                                 struct constraint_expr *cexpr)
259 {
260         u32 val1, val2;
261         struct context *c;
262         struct role_datum *r1, *r2;
263         struct mls_level *l1, *l2;
264         struct constraint_expr *e;
265         int s[CEXPR_MAXDEPTH];
266         int sp = -1;
267
268         for (e = cexpr; e; e = e->next) {
269                 switch (e->expr_type) {
270                 case CEXPR_NOT:
271                         BUG_ON(sp < 0);
272                         s[sp] = !s[sp];
273                         break;
274                 case CEXPR_AND:
275                         BUG_ON(sp < 1);
276                         sp--;
277                         s[sp] &= s[sp+1];
278                         break;
279                 case CEXPR_OR:
280                         BUG_ON(sp < 1);
281                         sp--;
282                         s[sp] |= s[sp+1];
283                         break;
284                 case CEXPR_ATTR:
285                         if (sp == (CEXPR_MAXDEPTH-1))
286                                 return 0;
287                         switch (e->attr) {
288                         case CEXPR_USER:
289                                 val1 = scontext->user;
290                                 val2 = tcontext->user;
291                                 break;
292                         case CEXPR_TYPE:
293                                 val1 = scontext->type;
294                                 val2 = tcontext->type;
295                                 break;
296                         case CEXPR_ROLE:
297                                 val1 = scontext->role;
298                                 val2 = tcontext->role;
299                                 r1 = policydb.role_val_to_struct[val1 - 1];
300                                 r2 = policydb.role_val_to_struct[val2 - 1];
301                                 switch (e->op) {
302                                 case CEXPR_DOM:
303                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
304                                                                   val2 - 1);
305                                         continue;
306                                 case CEXPR_DOMBY:
307                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
308                                                                   val1 - 1);
309                                         continue;
310                                 case CEXPR_INCOMP:
311                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
312                                                                     val2 - 1) &&
313                                                    !ebitmap_get_bit(&r2->dominates,
314                                                                     val1 - 1));
315                                         continue;
316                                 default:
317                                         break;
318                                 }
319                                 break;
320                         case CEXPR_L1L2:
321                                 l1 = &(scontext->range.level[0]);
322                                 l2 = &(tcontext->range.level[0]);
323                                 goto mls_ops;
324                         case CEXPR_L1H2:
325                                 l1 = &(scontext->range.level[0]);
326                                 l2 = &(tcontext->range.level[1]);
327                                 goto mls_ops;
328                         case CEXPR_H1L2:
329                                 l1 = &(scontext->range.level[1]);
330                                 l2 = &(tcontext->range.level[0]);
331                                 goto mls_ops;
332                         case CEXPR_H1H2:
333                                 l1 = &(scontext->range.level[1]);
334                                 l2 = &(tcontext->range.level[1]);
335                                 goto mls_ops;
336                         case CEXPR_L1H1:
337                                 l1 = &(scontext->range.level[0]);
338                                 l2 = &(scontext->range.level[1]);
339                                 goto mls_ops;
340                         case CEXPR_L2H2:
341                                 l1 = &(tcontext->range.level[0]);
342                                 l2 = &(tcontext->range.level[1]);
343                                 goto mls_ops;
344 mls_ops:
345                         switch (e->op) {
346                         case CEXPR_EQ:
347                                 s[++sp] = mls_level_eq(l1, l2);
348                                 continue;
349                         case CEXPR_NEQ:
350                                 s[++sp] = !mls_level_eq(l1, l2);
351                                 continue;
352                         case CEXPR_DOM:
353                                 s[++sp] = mls_level_dom(l1, l2);
354                                 continue;
355                         case CEXPR_DOMBY:
356                                 s[++sp] = mls_level_dom(l2, l1);
357                                 continue;
358                         case CEXPR_INCOMP:
359                                 s[++sp] = mls_level_incomp(l2, l1);
360                                 continue;
361                         default:
362                                 BUG();
363                                 return 0;
364                         }
365                         break;
366                         default:
367                                 BUG();
368                                 return 0;
369                         }
370
371                         switch (e->op) {
372                         case CEXPR_EQ:
373                                 s[++sp] = (val1 == val2);
374                                 break;
375                         case CEXPR_NEQ:
376                                 s[++sp] = (val1 != val2);
377                                 break;
378                         default:
379                                 BUG();
380                                 return 0;
381                         }
382                         break;
383                 case CEXPR_NAMES:
384                         if (sp == (CEXPR_MAXDEPTH-1))
385                                 return 0;
386                         c = scontext;
387                         if (e->attr & CEXPR_TARGET)
388                                 c = tcontext;
389                         else if (e->attr & CEXPR_XTARGET) {
390                                 c = xcontext;
391                                 if (!c) {
392                                         BUG();
393                                         return 0;
394                                 }
395                         }
396                         if (e->attr & CEXPR_USER)
397                                 val1 = c->user;
398                         else if (e->attr & CEXPR_ROLE)
399                                 val1 = c->role;
400                         else if (e->attr & CEXPR_TYPE)
401                                 val1 = c->type;
402                         else {
403                                 BUG();
404                                 return 0;
405                         }
406
407                         switch (e->op) {
408                         case CEXPR_EQ:
409                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
410                                 break;
411                         case CEXPR_NEQ:
412                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
413                                 break;
414                         default:
415                                 BUG();
416                                 return 0;
417                         }
418                         break;
419                 default:
420                         BUG();
421                         return 0;
422                 }
423         }
424
425         BUG_ON(sp != 0);
426         return s[0];
427 }
428
429 /*
430  * security_dump_masked_av - dumps masked permissions during
431  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
432  */
433 static int dump_masked_av_helper(void *k, void *d, void *args)
434 {
435         struct perm_datum *pdatum = d;
436         char **permission_names = args;
437
438         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
439
440         permission_names[pdatum->value - 1] = (char *)k;
441
442         return 0;
443 }
444
445 static void security_dump_masked_av(struct context *scontext,
446                                     struct context *tcontext,
447                                     u16 tclass,
448                                     u32 permissions,
449                                     const char *reason)
450 {
451         struct common_datum *common_dat;
452         struct class_datum *tclass_dat;
453         struct audit_buffer *ab;
454         char *tclass_name;
455         char *scontext_name = NULL;
456         char *tcontext_name = NULL;
457         char *permission_names[32];
458         int index, length;
459         bool need_comma = false;
460
461         if (!permissions)
462                 return;
463
464         tclass_name = policydb.p_class_val_to_name[tclass - 1];
465         tclass_dat = policydb.class_val_to_struct[tclass - 1];
466         common_dat = tclass_dat->comdatum;
467
468         /* init permission_names */
469         if (common_dat &&
470             hashtab_map(common_dat->permissions.table,
471                         dump_masked_av_helper, permission_names) < 0)
472                 goto out;
473
474         if (hashtab_map(tclass_dat->permissions.table,
475                         dump_masked_av_helper, permission_names) < 0)
476                 goto out;
477
478         /* get scontext/tcontext in text form */
479         if (context_struct_to_string(scontext,
480                                      &scontext_name, &length) < 0)
481                 goto out;
482
483         if (context_struct_to_string(tcontext,
484                                      &tcontext_name, &length) < 0)
485                 goto out;
486
487         /* audit a message */
488         ab = audit_log_start(current->audit_context,
489                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
490         if (!ab)
491                 goto out;
492
493         audit_log_format(ab, "op=security_compute_av reason=%s "
494                          "scontext=%s tcontext=%s tclass=%s perms=",
495                          reason, scontext_name, tcontext_name, tclass_name);
496
497         for (index = 0; index < 32; index++) {
498                 u32 mask = (1 << index);
499
500                 if ((mask & permissions) == 0)
501                         continue;
502
503                 audit_log_format(ab, "%s%s",
504                                  need_comma ? "," : "",
505                                  permission_names[index]
506                                  ? permission_names[index] : "????");
507                 need_comma = true;
508         }
509         audit_log_end(ab);
510 out:
511         /* release scontext/tcontext */
512         kfree(tcontext_name);
513         kfree(scontext_name);
514
515         return;
516 }
517
518 /*
519  * security_boundary_permission - drops violated permissions
520  * on boundary constraint.
521  */
522 static void type_attribute_bounds_av(struct context *scontext,
523                                      struct context *tcontext,
524                                      u16 tclass,
525                                      struct av_decision *avd)
526 {
527         struct type_datum *source
528                 = policydb.type_val_to_struct[scontext->type - 1];
529
530         if (source->bounds) {
531                 struct context lo_scontext;
532                 struct av_decision lo_avd;
533                 u32 masked;
534
535                 memset(&lo_avd, 0, sizeof(lo_avd));
536
537                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
538                 lo_scontext.type = source->bounds;
539
540                 context_struct_compute_av(&lo_scontext,
541                                           tcontext,
542                                           tclass,
543                                           &lo_avd);
544                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
545                         return;         /* no masked permission */
546                 masked = ~lo_avd.allowed & avd->allowed;
547
548                 /* mask violated permissions */
549                 avd->allowed &= ~masked;
550
551                 /* audit masked permissions */
552                 security_dump_masked_av(scontext, tcontext,
553                                         tclass, masked, "bounds");
554         }
555 }
556
557 /*
558  * Compute access vectors based on a context structure pair for
559  * the permissions in a particular class.
560  */
561 static void context_struct_compute_av(struct context *scontext,
562                                       struct context *tcontext,
563                                       u16 tclass,
564                                       struct av_decision *avd)
565 {
566         struct constraint_node *constraint;
567         struct role_allow *ra;
568         struct avtab_key avkey;
569         struct avtab_node *node;
570         struct class_datum *tclass_datum;
571         struct ebitmap *sattr, *tattr;
572         struct ebitmap_node *snode, *tnode;
573         unsigned int i, j;
574
575         avd->allowed = 0;
576         avd->auditallow = 0;
577         avd->auditdeny = 0xffffffff;
578
579         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
580                 if (printk_ratelimit())
581                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
582                 return;
583         }
584
585         tclass_datum = policydb.class_val_to_struct[tclass - 1];
586
587         /*
588          * If a specific type enforcement rule was defined for
589          * this permission check, then use it.
590          */
591         avkey.target_class = tclass;
592         avkey.specified = AVTAB_AV;
593         sattr = &policydb.type_attr_map[scontext->type - 1];
594         tattr = &policydb.type_attr_map[tcontext->type - 1];
595         ebitmap_for_each_positive_bit(sattr, snode, i) {
596                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
597                         avkey.source_type = i + 1;
598                         avkey.target_type = j + 1;
599                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
600                              node;
601                              node = avtab_search_node_next(node, avkey.specified)) {
602                                 if (node->key.specified == AVTAB_ALLOWED)
603                                         avd->allowed |= node->datum.data;
604                                 else if (node->key.specified == AVTAB_AUDITALLOW)
605                                         avd->auditallow |= node->datum.data;
606                                 else if (node->key.specified == AVTAB_AUDITDENY)
607                                         avd->auditdeny &= node->datum.data;
608                         }
609
610                         /* Check conditional av table for additional permissions */
611                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
612
613                 }
614         }
615
616         /*
617          * Remove any permissions prohibited by a constraint (this includes
618          * the MLS policy).
619          */
620         constraint = tclass_datum->constraints;
621         while (constraint) {
622                 if ((constraint->permissions & (avd->allowed)) &&
623                     !constraint_expr_eval(scontext, tcontext, NULL,
624                                           constraint->expr)) {
625                         avd->allowed &= ~(constraint->permissions);
626                 }
627                 constraint = constraint->next;
628         }
629
630         /*
631          * If checking process transition permission and the
632          * role is changing, then check the (current_role, new_role)
633          * pair.
634          */
635         if (tclass == policydb.process_class &&
636             (avd->allowed & policydb.process_trans_perms) &&
637             scontext->role != tcontext->role) {
638                 for (ra = policydb.role_allow; ra; ra = ra->next) {
639                         if (scontext->role == ra->role &&
640                             tcontext->role == ra->new_role)
641                                 break;
642                 }
643                 if (!ra)
644                         avd->allowed &= ~policydb.process_trans_perms;
645         }
646
647         /*
648          * If the given source and target types have boundary
649          * constraint, lazy checks have to mask any violated
650          * permission and notice it to userspace via audit.
651          */
652         type_attribute_bounds_av(scontext, tcontext,
653                                  tclass, avd);
654 }
655
656 static int security_validtrans_handle_fail(struct context *ocontext,
657                                            struct context *ncontext,
658                                            struct context *tcontext,
659                                            u16 tclass)
660 {
661         char *o = NULL, *n = NULL, *t = NULL;
662         u32 olen, nlen, tlen;
663
664         if (context_struct_to_string(ocontext, &o, &olen) < 0)
665                 goto out;
666         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
667                 goto out;
668         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
669                 goto out;
670         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
671                   "security_validate_transition:  denied for"
672                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
673                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
674 out:
675         kfree(o);
676         kfree(n);
677         kfree(t);
678
679         if (!selinux_enforcing)
680                 return 0;
681         return -EPERM;
682 }
683
684 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
685                                  u16 orig_tclass)
686 {
687         struct context *ocontext;
688         struct context *ncontext;
689         struct context *tcontext;
690         struct class_datum *tclass_datum;
691         struct constraint_node *constraint;
692         u16 tclass;
693         int rc = 0;
694
695         if (!ss_initialized)
696                 return 0;
697
698         read_lock(&policy_rwlock);
699
700         tclass = unmap_class(orig_tclass);
701
702         if (!tclass || tclass > policydb.p_classes.nprim) {
703                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
704                         __func__, tclass);
705                 rc = -EINVAL;
706                 goto out;
707         }
708         tclass_datum = policydb.class_val_to_struct[tclass - 1];
709
710         ocontext = sidtab_search(&sidtab, oldsid);
711         if (!ocontext) {
712                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
713                         __func__, oldsid);
714                 rc = -EINVAL;
715                 goto out;
716         }
717
718         ncontext = sidtab_search(&sidtab, newsid);
719         if (!ncontext) {
720                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
721                         __func__, newsid);
722                 rc = -EINVAL;
723                 goto out;
724         }
725
726         tcontext = sidtab_search(&sidtab, tasksid);
727         if (!tcontext) {
728                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
729                         __func__, tasksid);
730                 rc = -EINVAL;
731                 goto out;
732         }
733
734         constraint = tclass_datum->validatetrans;
735         while (constraint) {
736                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
737                                           constraint->expr)) {
738                         rc = security_validtrans_handle_fail(ocontext, ncontext,
739                                                              tcontext, tclass);
740                         goto out;
741                 }
742                 constraint = constraint->next;
743         }
744
745 out:
746         read_unlock(&policy_rwlock);
747         return rc;
748 }
749
750 /*
751  * security_bounded_transition - check whether the given
752  * transition is directed to bounded, or not.
753  * It returns 0, if @newsid is bounded by @oldsid.
754  * Otherwise, it returns error code.
755  *
756  * @oldsid : current security identifier
757  * @newsid : destinated security identifier
758  */
759 int security_bounded_transition(u32 old_sid, u32 new_sid)
760 {
761         struct context *old_context, *new_context;
762         struct type_datum *type;
763         int index;
764         int rc = -EINVAL;
765
766         read_lock(&policy_rwlock);
767
768         old_context = sidtab_search(&sidtab, old_sid);
769         if (!old_context) {
770                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
771                        __func__, old_sid);
772                 goto out;
773         }
774
775         new_context = sidtab_search(&sidtab, new_sid);
776         if (!new_context) {
777                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
778                        __func__, new_sid);
779                 goto out;
780         }
781
782         /* type/domain unchanged */
783         if (old_context->type == new_context->type) {
784                 rc = 0;
785                 goto out;
786         }
787
788         index = new_context->type;
789         while (true) {
790                 type = policydb.type_val_to_struct[index - 1];
791                 BUG_ON(!type);
792
793                 /* not bounded anymore */
794                 if (!type->bounds) {
795                         rc = -EPERM;
796                         break;
797                 }
798
799                 /* @newsid is bounded by @oldsid */
800                 if (type->bounds == old_context->type) {
801                         rc = 0;
802                         break;
803                 }
804                 index = type->bounds;
805         }
806
807         if (rc) {
808                 char *old_name = NULL;
809                 char *new_name = NULL;
810                 int length;
811
812                 if (!context_struct_to_string(old_context,
813                                               &old_name, &length) &&
814                     !context_struct_to_string(new_context,
815                                               &new_name, &length)) {
816                         audit_log(current->audit_context,
817                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
818                                   "op=security_bounded_transition "
819                                   "result=denied "
820                                   "oldcontext=%s newcontext=%s",
821                                   old_name, new_name);
822                 }
823                 kfree(new_name);
824                 kfree(old_name);
825         }
826 out:
827         read_unlock(&policy_rwlock);
828
829         return rc;
830 }
831
832 static void avd_init(struct av_decision *avd)
833 {
834         avd->allowed = 0;
835         avd->auditallow = 0;
836         avd->auditdeny = 0xffffffff;
837         avd->seqno = latest_granting;
838         avd->flags = 0;
839 }
840
841
842 /**
843  * security_compute_av - Compute access vector decisions.
844  * @ssid: source security identifier
845  * @tsid: target security identifier
846  * @tclass: target security class
847  * @avd: access vector decisions
848  *
849  * Compute a set of access vector decisions based on the
850  * SID pair (@ssid, @tsid) for the permissions in @tclass.
851  */
852 void security_compute_av(u32 ssid,
853                          u32 tsid,
854                          u16 orig_tclass,
855                          struct av_decision *avd)
856 {
857         u16 tclass;
858         struct context *scontext = NULL, *tcontext = NULL;
859
860         read_lock(&policy_rwlock);
861         avd_init(avd);
862         if (!ss_initialized)
863                 goto allow;
864
865         scontext = sidtab_search(&sidtab, ssid);
866         if (!scontext) {
867                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
868                        __func__, ssid);
869                 goto out;
870         }
871
872         /* permissive domain? */
873         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
874                 avd->flags |= AVD_FLAGS_PERMISSIVE;
875
876         tcontext = sidtab_search(&sidtab, tsid);
877         if (!tcontext) {
878                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
879                        __func__, tsid);
880                 goto out;
881         }
882
883         tclass = unmap_class(orig_tclass);
884         if (unlikely(orig_tclass && !tclass)) {
885                 if (policydb.allow_unknown)
886                         goto allow;
887                 goto out;
888         }
889         context_struct_compute_av(scontext, tcontext, tclass, avd);
890         map_decision(orig_tclass, avd, policydb.allow_unknown);
891 out:
892         read_unlock(&policy_rwlock);
893         return;
894 allow:
895         avd->allowed = 0xffffffff;
896         goto out;
897 }
898
899 void security_compute_av_user(u32 ssid,
900                               u32 tsid,
901                               u16 tclass,
902                               struct av_decision *avd)
903 {
904         struct context *scontext = NULL, *tcontext = NULL;
905
906         read_lock(&policy_rwlock);
907         avd_init(avd);
908         if (!ss_initialized)
909                 goto allow;
910
911         scontext = sidtab_search(&sidtab, ssid);
912         if (!scontext) {
913                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
914                        __func__, ssid);
915                 goto out;
916         }
917
918         /* permissive domain? */
919         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
920                 avd->flags |= AVD_FLAGS_PERMISSIVE;
921
922         tcontext = sidtab_search(&sidtab, tsid);
923         if (!tcontext) {
924                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
925                        __func__, tsid);
926                 goto out;
927         }
928
929         if (unlikely(!tclass)) {
930                 if (policydb.allow_unknown)
931                         goto allow;
932                 goto out;
933         }
934
935         context_struct_compute_av(scontext, tcontext, tclass, avd);
936  out:
937         read_unlock(&policy_rwlock);
938         return;
939 allow:
940         avd->allowed = 0xffffffff;
941         goto out;
942 }
943
944 /*
945  * Write the security context string representation of
946  * the context structure `context' into a dynamically
947  * allocated string of the correct size.  Set `*scontext'
948  * to point to this string and set `*scontext_len' to
949  * the length of the string.
950  */
951 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
952 {
953         char *scontextp;
954
955         *scontext = NULL;
956         *scontext_len = 0;
957
958         if (context->len) {
959                 *scontext_len = context->len;
960                 *scontext = kstrdup(context->str, GFP_ATOMIC);
961                 if (!(*scontext))
962                         return -ENOMEM;
963                 return 0;
964         }
965
966         /* Compute the size of the context. */
967         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
968         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
969         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
970         *scontext_len += mls_compute_context_len(context);
971
972         /* Allocate space for the context; caller must free this space. */
973         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
974         if (!scontextp)
975                 return -ENOMEM;
976         *scontext = scontextp;
977
978         /*
979          * Copy the user name, role name and type name into the context.
980          */
981         sprintf(scontextp, "%s:%s:%s",
982                 policydb.p_user_val_to_name[context->user - 1],
983                 policydb.p_role_val_to_name[context->role - 1],
984                 policydb.p_type_val_to_name[context->type - 1]);
985         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
986                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
987                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
988
989         mls_sid_to_context(context, &scontextp);
990
991         *scontextp = 0;
992
993         return 0;
994 }
995
996 #include "initial_sid_to_string.h"
997
998 const char *security_get_initial_sid_context(u32 sid)
999 {
1000         if (unlikely(sid > SECINITSID_NUM))
1001                 return NULL;
1002         return initial_sid_to_string[sid];
1003 }
1004
1005 static int security_sid_to_context_core(u32 sid, char **scontext,
1006                                         u32 *scontext_len, int force)
1007 {
1008         struct context *context;
1009         int rc = 0;
1010
1011         *scontext = NULL;
1012         *scontext_len  = 0;
1013
1014         if (!ss_initialized) {
1015                 if (sid <= SECINITSID_NUM) {
1016                         char *scontextp;
1017
1018                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1019                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1020                         if (!scontextp) {
1021                                 rc = -ENOMEM;
1022                                 goto out;
1023                         }
1024                         strcpy(scontextp, initial_sid_to_string[sid]);
1025                         *scontext = scontextp;
1026                         goto out;
1027                 }
1028                 printk(KERN_ERR "SELinux: %s:  called before initial "
1029                        "load_policy on unknown SID %d\n", __func__, sid);
1030                 rc = -EINVAL;
1031                 goto out;
1032         }
1033         read_lock(&policy_rwlock);
1034         if (force)
1035                 context = sidtab_search_force(&sidtab, sid);
1036         else
1037                 context = sidtab_search(&sidtab, sid);
1038         if (!context) {
1039                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1040                         __func__, sid);
1041                 rc = -EINVAL;
1042                 goto out_unlock;
1043         }
1044         rc = context_struct_to_string(context, scontext, scontext_len);
1045 out_unlock:
1046         read_unlock(&policy_rwlock);
1047 out:
1048         return rc;
1049
1050 }
1051
1052 /**
1053  * security_sid_to_context - Obtain a context for a given SID.
1054  * @sid: security identifier, SID
1055  * @scontext: security context
1056  * @scontext_len: length in bytes
1057  *
1058  * Write the string representation of the context associated with @sid
1059  * into a dynamically allocated string of the correct size.  Set @scontext
1060  * to point to this string and set @scontext_len to the length of the string.
1061  */
1062 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1063 {
1064         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1065 }
1066
1067 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1068 {
1069         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1070 }
1071
1072 /*
1073  * Caveat:  Mutates scontext.
1074  */
1075 static int string_to_context_struct(struct policydb *pol,
1076                                     struct sidtab *sidtabp,
1077                                     char *scontext,
1078                                     u32 scontext_len,
1079                                     struct context *ctx,
1080                                     u32 def_sid)
1081 {
1082         struct role_datum *role;
1083         struct type_datum *typdatum;
1084         struct user_datum *usrdatum;
1085         char *scontextp, *p, oldc;
1086         int rc = 0;
1087
1088         context_init(ctx);
1089
1090         /* Parse the security context. */
1091
1092         rc = -EINVAL;
1093         scontextp = (char *) scontext;
1094
1095         /* Extract the user. */
1096         p = scontextp;
1097         while (*p && *p != ':')
1098                 p++;
1099
1100         if (*p == 0)
1101                 goto out;
1102
1103         *p++ = 0;
1104
1105         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1106         if (!usrdatum)
1107                 goto out;
1108
1109         ctx->user = usrdatum->value;
1110
1111         /* Extract role. */
1112         scontextp = p;
1113         while (*p && *p != ':')
1114                 p++;
1115
1116         if (*p == 0)
1117                 goto out;
1118
1119         *p++ = 0;
1120
1121         role = hashtab_search(pol->p_roles.table, scontextp);
1122         if (!role)
1123                 goto out;
1124         ctx->role = role->value;
1125
1126         /* Extract type. */
1127         scontextp = p;
1128         while (*p && *p != ':')
1129                 p++;
1130         oldc = *p;
1131         *p++ = 0;
1132
1133         typdatum = hashtab_search(pol->p_types.table, scontextp);
1134         if (!typdatum || typdatum->attribute)
1135                 goto out;
1136
1137         ctx->type = typdatum->value;
1138
1139         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1140         if (rc)
1141                 goto out;
1142
1143         if ((p - scontext) < scontext_len) {
1144                 rc = -EINVAL;
1145                 goto out;
1146         }
1147
1148         /* Check the validity of the new context. */
1149         if (!policydb_context_isvalid(pol, ctx)) {
1150                 rc = -EINVAL;
1151                 goto out;
1152         }
1153         rc = 0;
1154 out:
1155         if (rc)
1156                 context_destroy(ctx);
1157         return rc;
1158 }
1159
1160 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1161                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1162                                         int force)
1163 {
1164         char *scontext2, *str = NULL;
1165         struct context context;
1166         int rc = 0;
1167
1168         if (!ss_initialized) {
1169                 int i;
1170
1171                 for (i = 1; i < SECINITSID_NUM; i++) {
1172                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1173                                 *sid = i;
1174                                 return 0;
1175                         }
1176                 }
1177                 *sid = SECINITSID_KERNEL;
1178                 return 0;
1179         }
1180         *sid = SECSID_NULL;
1181
1182         /* Copy the string so that we can modify the copy as we parse it. */
1183         scontext2 = kmalloc(scontext_len+1, gfp_flags);
1184         if (!scontext2)
1185                 return -ENOMEM;
1186         memcpy(scontext2, scontext, scontext_len);
1187         scontext2[scontext_len] = 0;
1188
1189         if (force) {
1190                 /* Save another copy for storing in uninterpreted form */
1191                 str = kstrdup(scontext2, gfp_flags);
1192                 if (!str) {
1193                         kfree(scontext2);
1194                         return -ENOMEM;
1195                 }
1196         }
1197
1198         read_lock(&policy_rwlock);
1199         rc = string_to_context_struct(&policydb, &sidtab,
1200                                       scontext2, scontext_len,
1201                                       &context, def_sid);
1202         if (rc == -EINVAL && force) {
1203                 context.str = str;
1204                 context.len = scontext_len;
1205                 str = NULL;
1206         } else if (rc)
1207                 goto out;
1208         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1209         context_destroy(&context);
1210 out:
1211         read_unlock(&policy_rwlock);
1212         kfree(scontext2);
1213         kfree(str);
1214         return rc;
1215 }
1216
1217 /**
1218  * security_context_to_sid - Obtain a SID for a given security context.
1219  * @scontext: security context
1220  * @scontext_len: length in bytes
1221  * @sid: security identifier, SID
1222  *
1223  * Obtains a SID associated with the security context that
1224  * has the string representation specified by @scontext.
1225  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1226  * memory is available, or 0 on success.
1227  */
1228 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1229 {
1230         return security_context_to_sid_core(scontext, scontext_len,
1231                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1232 }
1233
1234 /**
1235  * security_context_to_sid_default - Obtain a SID for a given security context,
1236  * falling back to specified default if needed.
1237  *
1238  * @scontext: security context
1239  * @scontext_len: length in bytes
1240  * @sid: security identifier, SID
1241  * @def_sid: default SID to assign on error
1242  *
1243  * Obtains a SID associated with the security context that
1244  * has the string representation specified by @scontext.
1245  * The default SID is passed to the MLS layer to be used to allow
1246  * kernel labeling of the MLS field if the MLS field is not present
1247  * (for upgrading to MLS without full relabel).
1248  * Implicitly forces adding of the context even if it cannot be mapped yet.
1249  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1250  * memory is available, or 0 on success.
1251  */
1252 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1253                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1254 {
1255         return security_context_to_sid_core(scontext, scontext_len,
1256                                             sid, def_sid, gfp_flags, 1);
1257 }
1258
1259 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1260                                   u32 *sid)
1261 {
1262         return security_context_to_sid_core(scontext, scontext_len,
1263                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1264 }
1265
1266 static int compute_sid_handle_invalid_context(
1267         struct context *scontext,
1268         struct context *tcontext,
1269         u16 tclass,
1270         struct context *newcontext)
1271 {
1272         char *s = NULL, *t = NULL, *n = NULL;
1273         u32 slen, tlen, nlen;
1274
1275         if (context_struct_to_string(scontext, &s, &slen) < 0)
1276                 goto out;
1277         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
1278                 goto out;
1279         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
1280                 goto out;
1281         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1282                   "security_compute_sid:  invalid context %s"
1283                   " for scontext=%s"
1284                   " tcontext=%s"
1285                   " tclass=%s",
1286                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
1287 out:
1288         kfree(s);
1289         kfree(t);
1290         kfree(n);
1291         if (!selinux_enforcing)
1292                 return 0;
1293         return -EACCES;
1294 }
1295
1296 static int security_compute_sid(u32 ssid,
1297                                 u32 tsid,
1298                                 u16 orig_tclass,
1299                                 u32 specified,
1300                                 u32 *out_sid,
1301                                 bool kern)
1302 {
1303         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1304         struct role_trans *roletr = NULL;
1305         struct avtab_key avkey;
1306         struct avtab_datum *avdatum;
1307         struct avtab_node *node;
1308         u16 tclass;
1309         int rc = 0;
1310
1311         if (!ss_initialized) {
1312                 switch (orig_tclass) {
1313                 case SECCLASS_PROCESS: /* kernel value */
1314                         *out_sid = ssid;
1315                         break;
1316                 default:
1317                         *out_sid = tsid;
1318                         break;
1319                 }
1320                 goto out;
1321         }
1322
1323         context_init(&newcontext);
1324
1325         read_lock(&policy_rwlock);
1326
1327         if (kern)
1328                 tclass = unmap_class(orig_tclass);
1329         else
1330                 tclass = orig_tclass;
1331
1332         scontext = sidtab_search(&sidtab, ssid);
1333         if (!scontext) {
1334                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1335                        __func__, ssid);
1336                 rc = -EINVAL;
1337                 goto out_unlock;
1338         }
1339         tcontext = sidtab_search(&sidtab, tsid);
1340         if (!tcontext) {
1341                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1342                        __func__, tsid);
1343                 rc = -EINVAL;
1344                 goto out_unlock;
1345         }
1346
1347         /* Set the user identity. */
1348         switch (specified) {
1349         case AVTAB_TRANSITION:
1350         case AVTAB_CHANGE:
1351                 /* Use the process user identity. */
1352                 newcontext.user = scontext->user;
1353                 break;
1354         case AVTAB_MEMBER:
1355                 /* Use the related object owner. */
1356                 newcontext.user = tcontext->user;
1357                 break;
1358         }
1359
1360         /* Set the role and type to default values. */
1361         if (tclass == policydb.process_class) {
1362                 /* Use the current role and type of process. */
1363                 newcontext.role = scontext->role;
1364                 newcontext.type = scontext->type;
1365         } else {
1366                 /* Use the well-defined object role. */
1367                 newcontext.role = OBJECT_R_VAL;
1368                 /* Use the type of the related object. */
1369                 newcontext.type = tcontext->type;
1370         }
1371
1372         /* Look for a type transition/member/change rule. */
1373         avkey.source_type = scontext->type;
1374         avkey.target_type = tcontext->type;
1375         avkey.target_class = tclass;
1376         avkey.specified = specified;
1377         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1378
1379         /* If no permanent rule, also check for enabled conditional rules */
1380         if (!avdatum) {
1381                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1382                 for (; node; node = avtab_search_node_next(node, specified)) {
1383                         if (node->key.specified & AVTAB_ENABLED) {
1384                                 avdatum = &node->datum;
1385                                 break;
1386                         }
1387                 }
1388         }
1389
1390         if (avdatum) {
1391                 /* Use the type from the type transition/member/change rule. */
1392                 newcontext.type = avdatum->data;
1393         }
1394
1395         /* Check for class-specific changes. */
1396         if  (tclass == policydb.process_class) {
1397                 if (specified & AVTAB_TRANSITION) {
1398                         /* Look for a role transition rule. */
1399                         for (roletr = policydb.role_tr; roletr;
1400                              roletr = roletr->next) {
1401                                 if (roletr->role == scontext->role &&
1402                                     roletr->type == tcontext->type) {
1403                                         /* Use the role transition rule. */
1404                                         newcontext.role = roletr->new_role;
1405                                         break;
1406                                 }
1407                         }
1408                 }
1409         }
1410
1411         /* Set the MLS attributes.
1412            This is done last because it may allocate memory. */
1413         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1414         if (rc)
1415                 goto out_unlock;
1416
1417         /* Check the validity of the context. */
1418         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1419                 rc = compute_sid_handle_invalid_context(scontext,
1420                                                         tcontext,
1421                                                         tclass,
1422                                                         &newcontext);
1423                 if (rc)
1424                         goto out_unlock;
1425         }
1426         /* Obtain the sid for the context. */
1427         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1428 out_unlock:
1429         read_unlock(&policy_rwlock);
1430         context_destroy(&newcontext);
1431 out:
1432         return rc;
1433 }
1434
1435 /**
1436  * security_transition_sid - Compute the SID for a new subject/object.
1437  * @ssid: source security identifier
1438  * @tsid: target security identifier
1439  * @tclass: target security class
1440  * @out_sid: security identifier for new subject/object
1441  *
1442  * Compute a SID to use for labeling a new subject or object in the
1443  * class @tclass based on a SID pair (@ssid, @tsid).
1444  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1445  * if insufficient memory is available, or %0 if the new SID was
1446  * computed successfully.
1447  */
1448 int security_transition_sid(u32 ssid,
1449                             u32 tsid,
1450                             u16 tclass,
1451                             u32 *out_sid)
1452 {
1453         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1454                                     out_sid, true);
1455 }
1456
1457 int security_transition_sid_user(u32 ssid,
1458                                  u32 tsid,
1459                                  u16 tclass,
1460                                  u32 *out_sid)
1461 {
1462         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1463                                     out_sid, false);
1464 }
1465
1466 /**
1467  * security_member_sid - Compute the SID for member selection.
1468  * @ssid: source security identifier
1469  * @tsid: target security identifier
1470  * @tclass: target security class
1471  * @out_sid: security identifier for selected member
1472  *
1473  * Compute a SID to use when selecting a member of a polyinstantiated
1474  * object of class @tclass based on a SID pair (@ssid, @tsid).
1475  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1476  * if insufficient memory is available, or %0 if the SID was
1477  * computed successfully.
1478  */
1479 int security_member_sid(u32 ssid,
1480                         u32 tsid,
1481                         u16 tclass,
1482                         u32 *out_sid)
1483 {
1484         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid,
1485                                     false);
1486 }
1487
1488 /**
1489  * security_change_sid - Compute the SID for object relabeling.
1490  * @ssid: source security identifier
1491  * @tsid: target security identifier
1492  * @tclass: target security class
1493  * @out_sid: security identifier for selected member
1494  *
1495  * Compute a SID to use for relabeling an object of class @tclass
1496  * based on a SID pair (@ssid, @tsid).
1497  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1498  * if insufficient memory is available, or %0 if the SID was
1499  * computed successfully.
1500  */
1501 int security_change_sid(u32 ssid,
1502                         u32 tsid,
1503                         u16 tclass,
1504                         u32 *out_sid)
1505 {
1506         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid,
1507                                     false);
1508 }
1509
1510 /* Clone the SID into the new SID table. */
1511 static int clone_sid(u32 sid,
1512                      struct context *context,
1513                      void *arg)
1514 {
1515         struct sidtab *s = arg;
1516
1517         if (sid > SECINITSID_NUM)
1518                 return sidtab_insert(s, sid, context);
1519         else
1520                 return 0;
1521 }
1522
1523 static inline int convert_context_handle_invalid_context(struct context *context)
1524 {
1525         int rc = 0;
1526
1527         if (selinux_enforcing) {
1528                 rc = -EINVAL;
1529         } else {
1530                 char *s;
1531                 u32 len;
1532
1533                 if (!context_struct_to_string(context, &s, &len)) {
1534                         printk(KERN_WARNING
1535                        "SELinux:  Context %s would be invalid if enforcing\n",
1536                                s);
1537                         kfree(s);
1538                 }
1539         }
1540         return rc;
1541 }
1542
1543 struct convert_context_args {
1544         struct policydb *oldp;
1545         struct policydb *newp;
1546 };
1547
1548 /*
1549  * Convert the values in the security context
1550  * structure `c' from the values specified
1551  * in the policy `p->oldp' to the values specified
1552  * in the policy `p->newp'.  Verify that the
1553  * context is valid under the new policy.
1554  */
1555 static int convert_context(u32 key,
1556                            struct context *c,
1557                            void *p)
1558 {
1559         struct convert_context_args *args;
1560         struct context oldc;
1561         struct ocontext *oc;
1562         struct mls_range *range;
1563         struct role_datum *role;
1564         struct type_datum *typdatum;
1565         struct user_datum *usrdatum;
1566         char *s;
1567         u32 len;
1568         int rc = 0;
1569
1570         if (key <= SECINITSID_NUM)
1571                 goto out;
1572
1573         args = p;
1574
1575         if (c->str) {
1576                 struct context ctx;
1577                 s = kstrdup(c->str, GFP_KERNEL);
1578                 if (!s) {
1579                         rc = -ENOMEM;
1580                         goto out;
1581                 }
1582                 rc = string_to_context_struct(args->newp, NULL, s,
1583                                               c->len, &ctx, SECSID_NULL);
1584                 kfree(s);
1585                 if (!rc) {
1586                         printk(KERN_INFO
1587                        "SELinux:  Context %s became valid (mapped).\n",
1588                                c->str);
1589                         /* Replace string with mapped representation. */
1590                         kfree(c->str);
1591                         memcpy(c, &ctx, sizeof(*c));
1592                         goto out;
1593                 } else if (rc == -EINVAL) {
1594                         /* Retain string representation for later mapping. */
1595                         rc = 0;
1596                         goto out;
1597                 } else {
1598                         /* Other error condition, e.g. ENOMEM. */
1599                         printk(KERN_ERR
1600                        "SELinux:   Unable to map context %s, rc = %d.\n",
1601                                c->str, -rc);
1602                         goto out;
1603                 }
1604         }
1605
1606         rc = context_cpy(&oldc, c);
1607         if (rc)
1608                 goto out;
1609
1610         rc = -EINVAL;
1611
1612         /* Convert the user. */
1613         usrdatum = hashtab_search(args->newp->p_users.table,
1614                                   args->oldp->p_user_val_to_name[c->user - 1]);
1615         if (!usrdatum)
1616                 goto bad;
1617         c->user = usrdatum->value;
1618
1619         /* Convert the role. */
1620         role = hashtab_search(args->newp->p_roles.table,
1621                               args->oldp->p_role_val_to_name[c->role - 1]);
1622         if (!role)
1623                 goto bad;
1624         c->role = role->value;
1625
1626         /* Convert the type. */
1627         typdatum = hashtab_search(args->newp->p_types.table,
1628                                   args->oldp->p_type_val_to_name[c->type - 1]);
1629         if (!typdatum)
1630                 goto bad;
1631         c->type = typdatum->value;
1632
1633         /* Convert the MLS fields if dealing with MLS policies */
1634         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1635                 rc = mls_convert_context(args->oldp, args->newp, c);
1636                 if (rc)
1637                         goto bad;
1638         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1639                 /*
1640                  * Switching between MLS and non-MLS policy:
1641                  * free any storage used by the MLS fields in the
1642                  * context for all existing entries in the sidtab.
1643                  */
1644                 mls_context_destroy(c);
1645         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1646                 /*
1647                  * Switching between non-MLS and MLS policy:
1648                  * ensure that the MLS fields of the context for all
1649                  * existing entries in the sidtab are filled in with a
1650                  * suitable default value, likely taken from one of the
1651                  * initial SIDs.
1652                  */
1653                 oc = args->newp->ocontexts[OCON_ISID];
1654                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1655                         oc = oc->next;
1656                 if (!oc) {
1657                         printk(KERN_ERR "SELinux:  unable to look up"
1658                                 " the initial SIDs list\n");
1659                         goto bad;
1660                 }
1661                 range = &oc->context[0].range;
1662                 rc = mls_range_set(c, range);
1663                 if (rc)
1664                         goto bad;
1665         }
1666
1667         /* Check the validity of the new context. */
1668         if (!policydb_context_isvalid(args->newp, c)) {
1669                 rc = convert_context_handle_invalid_context(&oldc);
1670                 if (rc)
1671                         goto bad;
1672         }
1673
1674         context_destroy(&oldc);
1675         rc = 0;
1676 out:
1677         return rc;
1678 bad:
1679         /* Map old representation to string and save it. */
1680         if (context_struct_to_string(&oldc, &s, &len))
1681                 return -ENOMEM;
1682         context_destroy(&oldc);
1683         context_destroy(c);
1684         c->str = s;
1685         c->len = len;
1686         printk(KERN_INFO
1687                "SELinux:  Context %s became invalid (unmapped).\n",
1688                c->str);
1689         rc = 0;
1690         goto out;
1691 }
1692
1693 static void security_load_policycaps(void)
1694 {
1695         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1696                                                   POLICYDB_CAPABILITY_NETPEER);
1697         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1698                                                   POLICYDB_CAPABILITY_OPENPERM);
1699 }
1700
1701 extern void selinux_complete_init(void);
1702 static int security_preserve_bools(struct policydb *p);
1703
1704 /**
1705  * security_load_policy - Load a security policy configuration.
1706  * @data: binary policy data
1707  * @len: length of data in bytes
1708  *
1709  * Load a new set of security policy configuration data,
1710  * validate it and convert the SID table as necessary.
1711  * This function will flush the access vector cache after
1712  * loading the new policy.
1713  */
1714 int security_load_policy(void *data, size_t len)
1715 {
1716         struct policydb oldpolicydb, newpolicydb;
1717         struct sidtab oldsidtab, newsidtab;
1718         struct selinux_mapping *oldmap, *map = NULL;
1719         struct convert_context_args args;
1720         u32 seqno;
1721         u16 map_size;
1722         int rc = 0;
1723         struct policy_file file = { data, len }, *fp = &file;
1724
1725         if (!ss_initialized) {
1726                 avtab_cache_init();
1727                 if (policydb_read(&policydb, fp)) {
1728                         avtab_cache_destroy();
1729                         return -EINVAL;
1730                 }
1731                 if (selinux_set_mapping(&policydb, secclass_map,
1732                                         &current_mapping,
1733                                         &current_mapping_size)) {
1734                         policydb_destroy(&policydb);
1735                         avtab_cache_destroy();
1736                         return -EINVAL;
1737                 }
1738                 if (policydb_load_isids(&policydb, &sidtab)) {
1739                         policydb_destroy(&policydb);
1740                         avtab_cache_destroy();
1741                         return -EINVAL;
1742                 }
1743                 security_load_policycaps();
1744                 ss_initialized = 1;
1745                 seqno = ++latest_granting;
1746                 selinux_complete_init();
1747                 avc_ss_reset(seqno);
1748                 selnl_notify_policyload(seqno);
1749                 selinux_netlbl_cache_invalidate();
1750                 selinux_xfrm_notify_policyload();
1751                 return 0;
1752         }
1753
1754 #if 0
1755         sidtab_hash_eval(&sidtab, "sids");
1756 #endif
1757
1758         if (policydb_read(&newpolicydb, fp))
1759                 return -EINVAL;
1760
1761         /* If switching between different policy types, log MLS status */
1762         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1763                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1764         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1765                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1766
1767         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1768         if (rc) {
1769                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1770                 policydb_destroy(&newpolicydb);
1771                 return rc;
1772         }
1773
1774         if (selinux_set_mapping(&newpolicydb, secclass_map,
1775                                 &map, &map_size))
1776                 goto err;
1777
1778         rc = security_preserve_bools(&newpolicydb);
1779         if (rc) {
1780                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1781                 goto err;
1782         }
1783
1784         /* Clone the SID table. */
1785         sidtab_shutdown(&sidtab);
1786         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1787                 rc = -ENOMEM;
1788                 goto err;
1789         }
1790
1791         /*
1792          * Convert the internal representations of contexts
1793          * in the new SID table.
1794          */
1795         args.oldp = &policydb;
1796         args.newp = &newpolicydb;
1797         rc = sidtab_map(&newsidtab, convert_context, &args);
1798         if (rc) {
1799                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1800                         " representation of contexts in the new SID"
1801                         " table\n");
1802                 goto err;
1803         }
1804
1805         /* Save the old policydb and SID table to free later. */
1806         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1807         sidtab_set(&oldsidtab, &sidtab);
1808
1809         /* Install the new policydb and SID table. */
1810         write_lock_irq(&policy_rwlock);
1811         memcpy(&policydb, &newpolicydb, sizeof policydb);
1812         sidtab_set(&sidtab, &newsidtab);
1813         security_load_policycaps();
1814         oldmap = current_mapping;
1815         current_mapping = map;
1816         current_mapping_size = map_size;
1817         seqno = ++latest_granting;
1818         write_unlock_irq(&policy_rwlock);
1819
1820         /* Free the old policydb and SID table. */
1821         policydb_destroy(&oldpolicydb);
1822         sidtab_destroy(&oldsidtab);
1823         kfree(oldmap);
1824
1825         avc_ss_reset(seqno);
1826         selnl_notify_policyload(seqno);
1827         selinux_netlbl_cache_invalidate();
1828         selinux_xfrm_notify_policyload();
1829
1830         return 0;
1831
1832 err:
1833         kfree(map);
1834         sidtab_destroy(&newsidtab);
1835         policydb_destroy(&newpolicydb);
1836         return rc;
1837
1838 }
1839
1840 /**
1841  * security_port_sid - Obtain the SID for a port.
1842  * @protocol: protocol number
1843  * @port: port number
1844  * @out_sid: security identifier
1845  */
1846 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1847 {
1848         struct ocontext *c;
1849         int rc = 0;
1850
1851         read_lock(&policy_rwlock);
1852
1853         c = policydb.ocontexts[OCON_PORT];
1854         while (c) {
1855                 if (c->u.port.protocol == protocol &&
1856                     c->u.port.low_port <= port &&
1857                     c->u.port.high_port >= port)
1858                         break;
1859                 c = c->next;
1860         }
1861
1862         if (c) {
1863                 if (!c->sid[0]) {
1864                         rc = sidtab_context_to_sid(&sidtab,
1865                                                    &c->context[0],
1866                                                    &c->sid[0]);
1867                         if (rc)
1868                                 goto out;
1869                 }
1870                 *out_sid = c->sid[0];
1871         } else {
1872                 *out_sid = SECINITSID_PORT;
1873         }
1874
1875 out:
1876         read_unlock(&policy_rwlock);
1877         return rc;
1878 }
1879
1880 /**
1881  * security_netif_sid - Obtain the SID for a network interface.
1882  * @name: interface name
1883  * @if_sid: interface SID
1884  */
1885 int security_netif_sid(char *name, u32 *if_sid)
1886 {
1887         int rc = 0;
1888         struct ocontext *c;
1889
1890         read_lock(&policy_rwlock);
1891
1892         c = policydb.ocontexts[OCON_NETIF];
1893         while (c) {
1894                 if (strcmp(name, c->u.name) == 0)
1895                         break;
1896                 c = c->next;
1897         }
1898
1899         if (c) {
1900                 if (!c->sid[0] || !c->sid[1]) {
1901                         rc = sidtab_context_to_sid(&sidtab,
1902                                                   &c->context[0],
1903                                                   &c->sid[0]);
1904                         if (rc)
1905                                 goto out;
1906                         rc = sidtab_context_to_sid(&sidtab,
1907                                                    &c->context[1],
1908                                                    &c->sid[1]);
1909                         if (rc)
1910                                 goto out;
1911                 }
1912                 *if_sid = c->sid[0];
1913         } else
1914                 *if_sid = SECINITSID_NETIF;
1915
1916 out:
1917         read_unlock(&policy_rwlock);
1918         return rc;
1919 }
1920
1921 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1922 {
1923         int i, fail = 0;
1924
1925         for (i = 0; i < 4; i++)
1926                 if (addr[i] != (input[i] & mask[i])) {
1927                         fail = 1;
1928                         break;
1929                 }
1930
1931         return !fail;
1932 }
1933
1934 /**
1935  * security_node_sid - Obtain the SID for a node (host).
1936  * @domain: communication domain aka address family
1937  * @addrp: address
1938  * @addrlen: address length in bytes
1939  * @out_sid: security identifier
1940  */
1941 int security_node_sid(u16 domain,
1942                       void *addrp,
1943                       u32 addrlen,
1944                       u32 *out_sid)
1945 {
1946         int rc = 0;
1947         struct ocontext *c;
1948
1949         read_lock(&policy_rwlock);
1950
1951         switch (domain) {
1952         case AF_INET: {
1953                 u32 addr;
1954
1955                 if (addrlen != sizeof(u32)) {
1956                         rc = -EINVAL;
1957                         goto out;
1958                 }
1959
1960                 addr = *((u32 *)addrp);
1961
1962                 c = policydb.ocontexts[OCON_NODE];
1963                 while (c) {
1964                         if (c->u.node.addr == (addr & c->u.node.mask))
1965                                 break;
1966                         c = c->next;
1967                 }
1968                 break;
1969         }
1970
1971         case AF_INET6:
1972                 if (addrlen != sizeof(u64) * 2) {
1973                         rc = -EINVAL;
1974                         goto out;
1975                 }
1976                 c = policydb.ocontexts[OCON_NODE6];
1977                 while (c) {
1978                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1979                                                 c->u.node6.mask))
1980                                 break;
1981                         c = c->next;
1982                 }
1983                 break;
1984
1985         default:
1986                 *out_sid = SECINITSID_NODE;
1987                 goto out;
1988         }
1989
1990         if (c) {
1991                 if (!c->sid[0]) {
1992                         rc = sidtab_context_to_sid(&sidtab,
1993                                                    &c->context[0],
1994                                                    &c->sid[0]);
1995                         if (rc)
1996                                 goto out;
1997                 }
1998                 *out_sid = c->sid[0];
1999         } else {
2000                 *out_sid = SECINITSID_NODE;
2001         }
2002
2003 out:
2004         read_unlock(&policy_rwlock);
2005         return rc;
2006 }
2007
2008 #define SIDS_NEL 25
2009
2010 /**
2011  * security_get_user_sids - Obtain reachable SIDs for a user.
2012  * @fromsid: starting SID
2013  * @username: username
2014  * @sids: array of reachable SIDs for user
2015  * @nel: number of elements in @sids
2016  *
2017  * Generate the set of SIDs for legal security contexts
2018  * for a given user that can be reached by @fromsid.
2019  * Set *@sids to point to a dynamically allocated
2020  * array containing the set of SIDs.  Set *@nel to the
2021  * number of elements in the array.
2022  */
2023
2024 int security_get_user_sids(u32 fromsid,
2025                            char *username,
2026                            u32 **sids,
2027                            u32 *nel)
2028 {
2029         struct context *fromcon, usercon;
2030         u32 *mysids = NULL, *mysids2, sid;
2031         u32 mynel = 0, maxnel = SIDS_NEL;
2032         struct user_datum *user;
2033         struct role_datum *role;
2034         struct ebitmap_node *rnode, *tnode;
2035         int rc = 0, i, j;
2036
2037         *sids = NULL;
2038         *nel = 0;
2039
2040         if (!ss_initialized)
2041                 goto out;
2042
2043         read_lock(&policy_rwlock);
2044
2045         context_init(&usercon);
2046
2047         fromcon = sidtab_search(&sidtab, fromsid);
2048         if (!fromcon) {
2049                 rc = -EINVAL;
2050                 goto out_unlock;
2051         }
2052
2053         user = hashtab_search(policydb.p_users.table, username);
2054         if (!user) {
2055                 rc = -EINVAL;
2056                 goto out_unlock;
2057         }
2058         usercon.user = user->value;
2059
2060         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2061         if (!mysids) {
2062                 rc = -ENOMEM;
2063                 goto out_unlock;
2064         }
2065
2066         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2067                 role = policydb.role_val_to_struct[i];
2068                 usercon.role = i+1;
2069                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2070                         usercon.type = j+1;
2071
2072                         if (mls_setup_user_range(fromcon, user, &usercon))
2073                                 continue;
2074
2075                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2076                         if (rc)
2077                                 goto out_unlock;
2078                         if (mynel < maxnel) {
2079                                 mysids[mynel++] = sid;
2080                         } else {
2081                                 maxnel += SIDS_NEL;
2082                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2083                                 if (!mysids2) {
2084                                         rc = -ENOMEM;
2085                                         goto out_unlock;
2086                                 }
2087                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2088                                 kfree(mysids);
2089                                 mysids = mysids2;
2090                                 mysids[mynel++] = sid;
2091                         }
2092                 }
2093         }
2094
2095 out_unlock:
2096         read_unlock(&policy_rwlock);
2097         if (rc || !mynel) {
2098                 kfree(mysids);
2099                 goto out;
2100         }
2101
2102         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2103         if (!mysids2) {
2104                 rc = -ENOMEM;
2105                 kfree(mysids);
2106                 goto out;
2107         }
2108         for (i = 0, j = 0; i < mynel; i++) {
2109                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2110                                           SECCLASS_PROCESS, /* kernel value */
2111                                           PROCESS__TRANSITION, AVC_STRICT,
2112                                           NULL);
2113                 if (!rc)
2114                         mysids2[j++] = mysids[i];
2115                 cond_resched();
2116         }
2117         rc = 0;
2118         kfree(mysids);
2119         *sids = mysids2;
2120         *nel = j;
2121 out:
2122         return rc;
2123 }
2124
2125 /**
2126  * security_genfs_sid - Obtain a SID for a file in a filesystem
2127  * @fstype: filesystem type
2128  * @path: path from root of mount
2129  * @sclass: file security class
2130  * @sid: SID for path
2131  *
2132  * Obtain a SID to use for a file in a filesystem that
2133  * cannot support xattr or use a fixed labeling behavior like
2134  * transition SIDs or task SIDs.
2135  */
2136 int security_genfs_sid(const char *fstype,
2137                        char *path,
2138                        u16 orig_sclass,
2139                        u32 *sid)
2140 {
2141         int len;
2142         u16 sclass;
2143         struct genfs *genfs;
2144         struct ocontext *c;
2145         int rc = 0, cmp = 0;
2146
2147         while (path[0] == '/' && path[1] == '/')
2148                 path++;
2149
2150         read_lock(&policy_rwlock);
2151
2152         sclass = unmap_class(orig_sclass);
2153
2154         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2155                 cmp = strcmp(fstype, genfs->fstype);
2156                 if (cmp <= 0)
2157                         break;
2158         }
2159
2160         if (!genfs || cmp) {
2161                 *sid = SECINITSID_UNLABELED;
2162                 rc = -ENOENT;
2163                 goto out;
2164         }
2165
2166         for (c = genfs->head; c; c = c->next) {
2167                 len = strlen(c->u.name);
2168                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2169                     (strncmp(c->u.name, path, len) == 0))
2170                         break;
2171         }
2172
2173         if (!c) {
2174                 *sid = SECINITSID_UNLABELED;
2175                 rc = -ENOENT;
2176                 goto out;
2177         }
2178
2179         if (!c->sid[0]) {
2180                 rc = sidtab_context_to_sid(&sidtab,
2181                                            &c->context[0],
2182                                            &c->sid[0]);
2183                 if (rc)
2184                         goto out;
2185         }
2186
2187         *sid = c->sid[0];
2188 out:
2189         read_unlock(&policy_rwlock);
2190         return rc;
2191 }
2192
2193 /**
2194  * security_fs_use - Determine how to handle labeling for a filesystem.
2195  * @fstype: filesystem type
2196  * @behavior: labeling behavior
2197  * @sid: SID for filesystem (superblock)
2198  */
2199 int security_fs_use(
2200         const char *fstype,
2201         unsigned int *behavior,
2202         u32 *sid)
2203 {
2204         int rc = 0;
2205         struct ocontext *c;
2206
2207         read_lock(&policy_rwlock);
2208
2209         c = policydb.ocontexts[OCON_FSUSE];
2210         while (c) {
2211                 if (strcmp(fstype, c->u.name) == 0)
2212                         break;
2213                 c = c->next;
2214         }
2215
2216         if (c) {
2217                 *behavior = c->v.behavior;
2218                 if (!c->sid[0]) {
2219                         rc = sidtab_context_to_sid(&sidtab,
2220                                                    &c->context[0],
2221                                                    &c->sid[0]);
2222                         if (rc)
2223                                 goto out;
2224                 }
2225                 *sid = c->sid[0];
2226         } else {
2227                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2228                 if (rc) {
2229                         *behavior = SECURITY_FS_USE_NONE;
2230                         rc = 0;
2231                 } else {
2232                         *behavior = SECURITY_FS_USE_GENFS;
2233                 }
2234         }
2235
2236 out:
2237         read_unlock(&policy_rwlock);
2238         return rc;
2239 }
2240
2241 int security_get_bools(int *len, char ***names, int **values)
2242 {
2243         int i, rc = -ENOMEM;
2244
2245         read_lock(&policy_rwlock);
2246         *names = NULL;
2247         *values = NULL;
2248
2249         *len = policydb.p_bools.nprim;
2250         if (!*len) {
2251                 rc = 0;
2252                 goto out;
2253         }
2254
2255        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2256         if (!*names)
2257                 goto err;
2258
2259        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2260         if (!*values)
2261                 goto err;
2262
2263         for (i = 0; i < *len; i++) {
2264                 size_t name_len;
2265                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2266                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2267                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2268                 if (!(*names)[i])
2269                         goto err;
2270                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2271                 (*names)[i][name_len - 1] = 0;
2272         }
2273         rc = 0;
2274 out:
2275         read_unlock(&policy_rwlock);
2276         return rc;
2277 err:
2278         if (*names) {
2279                 for (i = 0; i < *len; i++)
2280                         kfree((*names)[i]);
2281         }
2282         kfree(*values);
2283         goto out;
2284 }
2285
2286
2287 int security_set_bools(int len, int *values)
2288 {
2289         int i, rc = 0;
2290         int lenp, seqno = 0;
2291         struct cond_node *cur;
2292
2293         write_lock_irq(&policy_rwlock);
2294
2295         lenp = policydb.p_bools.nprim;
2296         if (len != lenp) {
2297                 rc = -EFAULT;
2298                 goto out;
2299         }
2300
2301         for (i = 0; i < len; i++) {
2302                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2303                         audit_log(current->audit_context, GFP_ATOMIC,
2304                                 AUDIT_MAC_CONFIG_CHANGE,
2305                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2306                                 policydb.p_bool_val_to_name[i],
2307                                 !!values[i],
2308                                 policydb.bool_val_to_struct[i]->state,
2309                                 audit_get_loginuid(current),
2310                                 audit_get_sessionid(current));
2311                 }
2312                 if (values[i])
2313                         policydb.bool_val_to_struct[i]->state = 1;
2314                 else
2315                         policydb.bool_val_to_struct[i]->state = 0;
2316         }
2317
2318         for (cur = policydb.cond_list; cur; cur = cur->next) {
2319                 rc = evaluate_cond_node(&policydb, cur);
2320                 if (rc)
2321                         goto out;
2322         }
2323
2324         seqno = ++latest_granting;
2325
2326 out:
2327         write_unlock_irq(&policy_rwlock);
2328         if (!rc) {
2329                 avc_ss_reset(seqno);
2330                 selnl_notify_policyload(seqno);
2331                 selinux_xfrm_notify_policyload();
2332         }
2333         return rc;
2334 }
2335
2336 int security_get_bool_value(int bool)
2337 {
2338         int rc = 0;
2339         int len;
2340
2341         read_lock(&policy_rwlock);
2342
2343         len = policydb.p_bools.nprim;
2344         if (bool >= len) {
2345                 rc = -EFAULT;
2346                 goto out;
2347         }
2348
2349         rc = policydb.bool_val_to_struct[bool]->state;
2350 out:
2351         read_unlock(&policy_rwlock);
2352         return rc;
2353 }
2354
2355 static int security_preserve_bools(struct policydb *p)
2356 {
2357         int rc, nbools = 0, *bvalues = NULL, i;
2358         char **bnames = NULL;
2359         struct cond_bool_datum *booldatum;
2360         struct cond_node *cur;
2361
2362         rc = security_get_bools(&nbools, &bnames, &bvalues);
2363         if (rc)
2364                 goto out;
2365         for (i = 0; i < nbools; i++) {
2366                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2367                 if (booldatum)
2368                         booldatum->state = bvalues[i];
2369         }
2370         for (cur = p->cond_list; cur; cur = cur->next) {
2371                 rc = evaluate_cond_node(p, cur);
2372                 if (rc)
2373                         goto out;
2374         }
2375
2376 out:
2377         if (bnames) {
2378                 for (i = 0; i < nbools; i++)
2379                         kfree(bnames[i]);
2380         }
2381         kfree(bnames);
2382         kfree(bvalues);
2383         return rc;
2384 }
2385
2386 /*
2387  * security_sid_mls_copy() - computes a new sid based on the given
2388  * sid and the mls portion of mls_sid.
2389  */
2390 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2391 {
2392         struct context *context1;
2393         struct context *context2;
2394         struct context newcon;
2395         char *s;
2396         u32 len;
2397         int rc = 0;
2398
2399         if (!ss_initialized || !policydb.mls_enabled) {
2400                 *new_sid = sid;
2401                 goto out;
2402         }
2403
2404         context_init(&newcon);
2405
2406         read_lock(&policy_rwlock);
2407         context1 = sidtab_search(&sidtab, sid);
2408         if (!context1) {
2409                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2410                         __func__, sid);
2411                 rc = -EINVAL;
2412                 goto out_unlock;
2413         }
2414
2415         context2 = sidtab_search(&sidtab, mls_sid);
2416         if (!context2) {
2417                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2418                         __func__, mls_sid);
2419                 rc = -EINVAL;
2420                 goto out_unlock;
2421         }
2422
2423         newcon.user = context1->user;
2424         newcon.role = context1->role;
2425         newcon.type = context1->type;
2426         rc = mls_context_cpy(&newcon, context2);
2427         if (rc)
2428                 goto out_unlock;
2429
2430         /* Check the validity of the new context. */
2431         if (!policydb_context_isvalid(&policydb, &newcon)) {
2432                 rc = convert_context_handle_invalid_context(&newcon);
2433                 if (rc)
2434                         goto bad;
2435         }
2436
2437         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2438         goto out_unlock;
2439
2440 bad:
2441         if (!context_struct_to_string(&newcon, &s, &len)) {
2442                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2443                           "security_sid_mls_copy: invalid context %s", s);
2444                 kfree(s);
2445         }
2446
2447 out_unlock:
2448         read_unlock(&policy_rwlock);
2449         context_destroy(&newcon);
2450 out:
2451         return rc;
2452 }
2453
2454 /**
2455  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2456  * @nlbl_sid: NetLabel SID
2457  * @nlbl_type: NetLabel labeling protocol type
2458  * @xfrm_sid: XFRM SID
2459  *
2460  * Description:
2461  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2462  * resolved into a single SID it is returned via @peer_sid and the function
2463  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2464  * returns a negative value.  A table summarizing the behavior is below:
2465  *
2466  *                                 | function return |      @sid
2467  *   ------------------------------+-----------------+-----------------
2468  *   no peer labels                |        0        |    SECSID_NULL
2469  *   single peer label             |        0        |    <peer_label>
2470  *   multiple, consistent labels   |        0        |    <peer_label>
2471  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2472  *
2473  */
2474 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2475                                  u32 xfrm_sid,
2476                                  u32 *peer_sid)
2477 {
2478         int rc;
2479         struct context *nlbl_ctx;
2480         struct context *xfrm_ctx;
2481
2482         /* handle the common (which also happens to be the set of easy) cases
2483          * right away, these two if statements catch everything involving a
2484          * single or absent peer SID/label */
2485         if (xfrm_sid == SECSID_NULL) {
2486                 *peer_sid = nlbl_sid;
2487                 return 0;
2488         }
2489         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2490          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2491          * is present */
2492         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2493                 *peer_sid = xfrm_sid;
2494                 return 0;
2495         }
2496
2497         /* we don't need to check ss_initialized here since the only way both
2498          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2499          * security server was initialized and ss_initialized was true */
2500         if (!policydb.mls_enabled) {
2501                 *peer_sid = SECSID_NULL;
2502                 return 0;
2503         }
2504
2505         read_lock(&policy_rwlock);
2506
2507         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2508         if (!nlbl_ctx) {
2509                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2510                        __func__, nlbl_sid);
2511                 rc = -EINVAL;
2512                 goto out_slowpath;
2513         }
2514         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2515         if (!xfrm_ctx) {
2516                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2517                        __func__, xfrm_sid);
2518                 rc = -EINVAL;
2519                 goto out_slowpath;
2520         }
2521         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2522
2523 out_slowpath:
2524         read_unlock(&policy_rwlock);
2525         if (rc == 0)
2526                 /* at present NetLabel SIDs/labels really only carry MLS
2527                  * information so if the MLS portion of the NetLabel SID
2528                  * matches the MLS portion of the labeled XFRM SID/label
2529                  * then pass along the XFRM SID as it is the most
2530                  * expressive */
2531                 *peer_sid = xfrm_sid;
2532         else
2533                 *peer_sid = SECSID_NULL;
2534         return rc;
2535 }
2536
2537 static int get_classes_callback(void *k, void *d, void *args)
2538 {
2539         struct class_datum *datum = d;
2540         char *name = k, **classes = args;
2541         int value = datum->value - 1;
2542
2543         classes[value] = kstrdup(name, GFP_ATOMIC);
2544         if (!classes[value])
2545                 return -ENOMEM;
2546
2547         return 0;
2548 }
2549
2550 int security_get_classes(char ***classes, int *nclasses)
2551 {
2552         int rc = -ENOMEM;
2553
2554         read_lock(&policy_rwlock);
2555
2556         *nclasses = policydb.p_classes.nprim;
2557         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2558         if (!*classes)
2559                 goto out;
2560
2561         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2562                         *classes);
2563         if (rc < 0) {
2564                 int i;
2565                 for (i = 0; i < *nclasses; i++)
2566                         kfree((*classes)[i]);
2567                 kfree(*classes);
2568         }
2569
2570 out:
2571         read_unlock(&policy_rwlock);
2572         return rc;
2573 }
2574
2575 static int get_permissions_callback(void *k, void *d, void *args)
2576 {
2577         struct perm_datum *datum = d;
2578         char *name = k, **perms = args;
2579         int value = datum->value - 1;
2580
2581         perms[value] = kstrdup(name, GFP_ATOMIC);
2582         if (!perms[value])
2583                 return -ENOMEM;
2584
2585         return 0;
2586 }
2587
2588 int security_get_permissions(char *class, char ***perms, int *nperms)
2589 {
2590         int rc = -ENOMEM, i;
2591         struct class_datum *match;
2592
2593         read_lock(&policy_rwlock);
2594
2595         match = hashtab_search(policydb.p_classes.table, class);
2596         if (!match) {
2597                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2598                         __func__, class);
2599                 rc = -EINVAL;
2600                 goto out;
2601         }
2602
2603         *nperms = match->permissions.nprim;
2604         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2605         if (!*perms)
2606                 goto out;
2607
2608         if (match->comdatum) {
2609                 rc = hashtab_map(match->comdatum->permissions.table,
2610                                 get_permissions_callback, *perms);
2611                 if (rc < 0)
2612                         goto err;
2613         }
2614
2615         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2616                         *perms);
2617         if (rc < 0)
2618                 goto err;
2619
2620 out:
2621         read_unlock(&policy_rwlock);
2622         return rc;
2623
2624 err:
2625         read_unlock(&policy_rwlock);
2626         for (i = 0; i < *nperms; i++)
2627                 kfree((*perms)[i]);
2628         kfree(*perms);
2629         return rc;
2630 }
2631
2632 int security_get_reject_unknown(void)
2633 {
2634         return policydb.reject_unknown;
2635 }
2636
2637 int security_get_allow_unknown(void)
2638 {
2639         return policydb.allow_unknown;
2640 }
2641
2642 /**
2643  * security_policycap_supported - Check for a specific policy capability
2644  * @req_cap: capability
2645  *
2646  * Description:
2647  * This function queries the currently loaded policy to see if it supports the
2648  * capability specified by @req_cap.  Returns true (1) if the capability is
2649  * supported, false (0) if it isn't supported.
2650  *
2651  */
2652 int security_policycap_supported(unsigned int req_cap)
2653 {
2654         int rc;
2655
2656         read_lock(&policy_rwlock);
2657         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2658         read_unlock(&policy_rwlock);
2659
2660         return rc;
2661 }
2662
2663 struct selinux_audit_rule {
2664         u32 au_seqno;
2665         struct context au_ctxt;
2666 };
2667
2668 void selinux_audit_rule_free(void *vrule)
2669 {
2670         struct selinux_audit_rule *rule = vrule;
2671
2672         if (rule) {
2673                 context_destroy(&rule->au_ctxt);
2674                 kfree(rule);
2675         }
2676 }
2677
2678 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2679 {
2680         struct selinux_audit_rule *tmprule;
2681         struct role_datum *roledatum;
2682         struct type_datum *typedatum;
2683         struct user_datum *userdatum;
2684         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2685         int rc = 0;
2686
2687         *rule = NULL;
2688
2689         if (!ss_initialized)
2690                 return -EOPNOTSUPP;
2691
2692         switch (field) {
2693         case AUDIT_SUBJ_USER:
2694         case AUDIT_SUBJ_ROLE:
2695         case AUDIT_SUBJ_TYPE:
2696         case AUDIT_OBJ_USER:
2697         case AUDIT_OBJ_ROLE:
2698         case AUDIT_OBJ_TYPE:
2699                 /* only 'equals' and 'not equals' fit user, role, and type */
2700                 if (op != Audit_equal && op != Audit_not_equal)
2701                         return -EINVAL;
2702                 break;
2703         case AUDIT_SUBJ_SEN:
2704         case AUDIT_SUBJ_CLR:
2705         case AUDIT_OBJ_LEV_LOW:
2706         case AUDIT_OBJ_LEV_HIGH:
2707                 /* we do not allow a range, indicated by the presense of '-' */
2708                 if (strchr(rulestr, '-'))
2709                         return -EINVAL;
2710                 break;
2711         default:
2712                 /* only the above fields are valid */
2713                 return -EINVAL;
2714         }
2715
2716         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2717         if (!tmprule)
2718                 return -ENOMEM;
2719
2720         context_init(&tmprule->au_ctxt);
2721
2722         read_lock(&policy_rwlock);
2723
2724         tmprule->au_seqno = latest_granting;
2725
2726         switch (field) {
2727         case AUDIT_SUBJ_USER:
2728         case AUDIT_OBJ_USER:
2729                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2730                 if (!userdatum)
2731                         rc = -EINVAL;
2732                 else
2733                         tmprule->au_ctxt.user = userdatum->value;
2734                 break;
2735         case AUDIT_SUBJ_ROLE:
2736         case AUDIT_OBJ_ROLE:
2737                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2738                 if (!roledatum)
2739                         rc = -EINVAL;
2740                 else
2741                         tmprule->au_ctxt.role = roledatum->value;
2742                 break;
2743         case AUDIT_SUBJ_TYPE:
2744         case AUDIT_OBJ_TYPE:
2745                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2746                 if (!typedatum)
2747                         rc = -EINVAL;
2748                 else
2749                         tmprule->au_ctxt.type = typedatum->value;
2750                 break;
2751         case AUDIT_SUBJ_SEN:
2752         case AUDIT_SUBJ_CLR:
2753         case AUDIT_OBJ_LEV_LOW:
2754         case AUDIT_OBJ_LEV_HIGH:
2755                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2756                 break;
2757         }
2758
2759         read_unlock(&policy_rwlock);
2760
2761         if (rc) {
2762                 selinux_audit_rule_free(tmprule);
2763                 tmprule = NULL;
2764         }
2765
2766         *rule = tmprule;
2767
2768         return rc;
2769 }
2770
2771 /* Check to see if the rule contains any selinux fields */
2772 int selinux_audit_rule_known(struct audit_krule *rule)
2773 {
2774         int i;
2775
2776         for (i = 0; i < rule->field_count; i++) {
2777                 struct audit_field *f = &rule->fields[i];
2778                 switch (f->type) {
2779                 case AUDIT_SUBJ_USER:
2780                 case AUDIT_SUBJ_ROLE:
2781                 case AUDIT_SUBJ_TYPE:
2782                 case AUDIT_SUBJ_SEN:
2783                 case AUDIT_SUBJ_CLR:
2784                 case AUDIT_OBJ_USER:
2785                 case AUDIT_OBJ_ROLE:
2786                 case AUDIT_OBJ_TYPE:
2787                 case AUDIT_OBJ_LEV_LOW:
2788                 case AUDIT_OBJ_LEV_HIGH:
2789                         return 1;
2790                 }
2791         }
2792
2793         return 0;
2794 }
2795
2796 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2797                              struct audit_context *actx)
2798 {
2799         struct context *ctxt;
2800         struct mls_level *level;
2801         struct selinux_audit_rule *rule = vrule;
2802         int match = 0;
2803
2804         if (!rule) {
2805                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2806                           "selinux_audit_rule_match: missing rule\n");
2807                 return -ENOENT;
2808         }
2809
2810         read_lock(&policy_rwlock);
2811
2812         if (rule->au_seqno < latest_granting) {
2813                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2814                           "selinux_audit_rule_match: stale rule\n");
2815                 match = -ESTALE;
2816                 goto out;
2817         }
2818
2819         ctxt = sidtab_search(&sidtab, sid);
2820         if (!ctxt) {
2821                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2822                           "selinux_audit_rule_match: unrecognized SID %d\n",
2823                           sid);
2824                 match = -ENOENT;
2825                 goto out;
2826         }
2827
2828         /* a field/op pair that is not caught here will simply fall through
2829            without a match */
2830         switch (field) {
2831         case AUDIT_SUBJ_USER:
2832         case AUDIT_OBJ_USER:
2833                 switch (op) {
2834                 case Audit_equal:
2835                         match = (ctxt->user == rule->au_ctxt.user);
2836                         break;
2837                 case Audit_not_equal:
2838                         match = (ctxt->user != rule->au_ctxt.user);
2839                         break;
2840                 }
2841                 break;
2842         case AUDIT_SUBJ_ROLE:
2843         case AUDIT_OBJ_ROLE:
2844                 switch (op) {
2845                 case Audit_equal:
2846                         match = (ctxt->role == rule->au_ctxt.role);
2847                         break;
2848                 case Audit_not_equal:
2849                         match = (ctxt->role != rule->au_ctxt.role);
2850                         break;
2851                 }
2852                 break;
2853         case AUDIT_SUBJ_TYPE:
2854         case AUDIT_OBJ_TYPE:
2855                 switch (op) {
2856                 case Audit_equal:
2857                         match = (ctxt->type == rule->au_ctxt.type);
2858                         break;
2859                 case Audit_not_equal:
2860                         match = (ctxt->type != rule->au_ctxt.type);
2861                         break;
2862                 }
2863                 break;
2864         case AUDIT_SUBJ_SEN:
2865         case AUDIT_SUBJ_CLR:
2866         case AUDIT_OBJ_LEV_LOW:
2867         case AUDIT_OBJ_LEV_HIGH:
2868                 level = ((field == AUDIT_SUBJ_SEN ||
2869                           field == AUDIT_OBJ_LEV_LOW) ?
2870                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2871                 switch (op) {
2872                 case Audit_equal:
2873                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2874                                              level);
2875                         break;
2876                 case Audit_not_equal:
2877                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2878                                               level);
2879                         break;
2880                 case Audit_lt:
2881                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2882                                                level) &&
2883                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2884                                                level));
2885                         break;
2886                 case Audit_le:
2887                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2888                                               level);
2889                         break;
2890                 case Audit_gt:
2891                         match = (mls_level_dom(level,
2892                                               &rule->au_ctxt.range.level[0]) &&
2893                                  !mls_level_eq(level,
2894                                                &rule->au_ctxt.range.level[0]));
2895                         break;
2896                 case Audit_ge:
2897                         match = mls_level_dom(level,
2898                                               &rule->au_ctxt.range.level[0]);
2899                         break;
2900                 }
2901         }
2902
2903 out:
2904         read_unlock(&policy_rwlock);
2905         return match;
2906 }
2907
2908 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2909
2910 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2911                                u16 class, u32 perms, u32 *retained)
2912 {
2913         int err = 0;
2914
2915         if (event == AVC_CALLBACK_RESET && aurule_callback)
2916                 err = aurule_callback();
2917         return err;
2918 }
2919
2920 static int __init aurule_init(void)
2921 {
2922         int err;
2923
2924         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2925                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2926         if (err)
2927                 panic("avc_add_callback() failed, error %d\n", err);
2928
2929         return err;
2930 }
2931 __initcall(aurule_init);
2932
2933 #ifdef CONFIG_NETLABEL
2934 /**
2935  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2936  * @secattr: the NetLabel packet security attributes
2937  * @sid: the SELinux SID
2938  *
2939  * Description:
2940  * Attempt to cache the context in @ctx, which was derived from the packet in
2941  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2942  * already been initialized.
2943  *
2944  */
2945 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2946                                       u32 sid)
2947 {
2948         u32 *sid_cache;
2949
2950         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2951         if (sid_cache == NULL)
2952                 return;
2953         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2954         if (secattr->cache == NULL) {
2955                 kfree(sid_cache);
2956                 return;
2957         }
2958
2959         *sid_cache = sid;
2960         secattr->cache->free = kfree;
2961         secattr->cache->data = sid_cache;
2962         secattr->flags |= NETLBL_SECATTR_CACHE;
2963 }
2964
2965 /**
2966  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2967  * @secattr: the NetLabel packet security attributes
2968  * @sid: the SELinux SID
2969  *
2970  * Description:
2971  * Convert the given NetLabel security attributes in @secattr into a
2972  * SELinux SID.  If the @secattr field does not contain a full SELinux
2973  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2974  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2975  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2976  * conversion for future lookups.  Returns zero on success, negative values on
2977  * failure.
2978  *
2979  */
2980 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2981                                    u32 *sid)
2982 {
2983         int rc = -EIDRM;
2984         struct context *ctx;
2985         struct context ctx_new;
2986
2987         if (!ss_initialized) {
2988                 *sid = SECSID_NULL;
2989                 return 0;
2990         }
2991
2992         read_lock(&policy_rwlock);
2993
2994         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2995                 *sid = *(u32 *)secattr->cache->data;
2996                 rc = 0;
2997         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2998                 *sid = secattr->attr.secid;
2999                 rc = 0;
3000         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3001                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3002                 if (ctx == NULL)
3003                         goto netlbl_secattr_to_sid_return;
3004
3005                 context_init(&ctx_new);
3006                 ctx_new.user = ctx->user;
3007                 ctx_new.role = ctx->role;
3008                 ctx_new.type = ctx->type;
3009                 mls_import_netlbl_lvl(&ctx_new, secattr);
3010                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3011                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3012                                                   secattr->attr.mls.cat) != 0)
3013                                 goto netlbl_secattr_to_sid_return;
3014                         memcpy(&ctx_new.range.level[1].cat,
3015                                &ctx_new.range.level[0].cat,
3016                                sizeof(ctx_new.range.level[0].cat));
3017                 }
3018                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
3019                         goto netlbl_secattr_to_sid_return_cleanup;
3020
3021                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3022                 if (rc != 0)
3023                         goto netlbl_secattr_to_sid_return_cleanup;
3024
3025                 security_netlbl_cache_add(secattr, *sid);
3026
3027                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3028         } else {
3029                 *sid = SECSID_NULL;
3030                 rc = 0;
3031         }
3032
3033 netlbl_secattr_to_sid_return:
3034         read_unlock(&policy_rwlock);
3035         return rc;
3036 netlbl_secattr_to_sid_return_cleanup:
3037         ebitmap_destroy(&ctx_new.range.level[0].cat);
3038         goto netlbl_secattr_to_sid_return;
3039 }
3040
3041 /**
3042  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3043  * @sid: the SELinux SID
3044  * @secattr: the NetLabel packet security attributes
3045  *
3046  * Description:
3047  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3048  * Returns zero on success, negative values on failure.
3049  *
3050  */
3051 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3052 {
3053         int rc;
3054         struct context *ctx;
3055
3056         if (!ss_initialized)
3057                 return 0;
3058
3059         read_lock(&policy_rwlock);
3060         ctx = sidtab_search(&sidtab, sid);
3061         if (ctx == NULL) {
3062                 rc = -ENOENT;
3063                 goto netlbl_sid_to_secattr_failure;
3064         }
3065         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
3066                                   GFP_ATOMIC);
3067         if (secattr->domain == NULL) {
3068                 rc = -ENOMEM;
3069                 goto netlbl_sid_to_secattr_failure;
3070         }
3071         secattr->attr.secid = sid;
3072         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3073         mls_export_netlbl_lvl(ctx, secattr);
3074         rc = mls_export_netlbl_cat(ctx, secattr);
3075         if (rc != 0)
3076                 goto netlbl_sid_to_secattr_failure;
3077         read_unlock(&policy_rwlock);
3078
3079         return 0;
3080
3081 netlbl_sid_to_secattr_failure:
3082         read_unlock(&policy_rwlock);
3083         return rc;
3084 }
3085 #endif /* CONFIG_NETLABEL */