2abbc49914e617e8abdeba7b92a44f3747f6a25b
[linux-2.6.git] / security / selinux / ss / services.c
1 /*
2  * Implementation of the security services.
3  *
4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
5  *           James Morris <jmorris@redhat.com>
6  *
7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
8  *
9  *      Support for enhanced MLS infrastructure.
10  *      Support for context based audit filters.
11  *
12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
13  *
14  *      Added conditional policy language extensions
15  *
16  * Updated: Hewlett-Packard <paul.moore@hp.com>
17  *
18  *      Added support for NetLabel
19  *      Added support for the policy capability bitmap
20  *
21  * Updated: Chad Sellers <csellers@tresys.com>
22  *
23  *  Added validation of kernel classes and permissions
24  *
25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
26  *
27  *  Added support for bounds domain and audit messaged on masked permissions
28  *
29  * Copyright (C) 2008, 2009 NEC Corporation
30  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
31  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
32  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
33  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
34  *      This program is free software; you can redistribute it and/or modify
35  *      it under the terms of the GNU General Public License as published by
36  *      the Free Software Foundation, version 2.
37  */
38 #include <linux/kernel.h>
39 #include <linux/slab.h>
40 #include <linux/string.h>
41 #include <linux/spinlock.h>
42 #include <linux/rcupdate.h>
43 #include <linux/errno.h>
44 #include <linux/in.h>
45 #include <linux/sched.h>
46 #include <linux/audit.h>
47 #include <linux/mutex.h>
48 #include <linux/selinux.h>
49 #include <net/netlabel.h>
50
51 #include "flask.h"
52 #include "avc.h"
53 #include "avc_ss.h"
54 #include "security.h"
55 #include "context.h"
56 #include "policydb.h"
57 #include "sidtab.h"
58 #include "services.h"
59 #include "conditional.h"
60 #include "mls.h"
61 #include "objsec.h"
62 #include "netlabel.h"
63 #include "xfrm.h"
64 #include "ebitmap.h"
65 #include "audit.h"
66
67 extern void selnl_notify_policyload(u32 seqno);
68
69 int selinux_policycap_netpeer;
70 int selinux_policycap_openperm;
71
72 static DEFINE_RWLOCK(policy_rwlock);
73
74 static struct sidtab sidtab;
75 struct policydb policydb;
76 int ss_initialized;
77
78 /*
79  * The largest sequence number that has been used when
80  * providing an access decision to the access vector cache.
81  * The sequence number only changes when a policy change
82  * occurs.
83  */
84 static u32 latest_granting;
85
86 /* Forward declaration. */
87 static int context_struct_to_string(struct context *context, char **scontext,
88                                     u32 *scontext_len);
89
90 static void context_struct_compute_av(struct context *scontext,
91                                       struct context *tcontext,
92                                       u16 tclass,
93                                       struct av_decision *avd);
94
95 struct selinux_mapping {
96         u16 value; /* policy value */
97         unsigned num_perms;
98         u32 perms[sizeof(u32) * 8];
99 };
100
101 static struct selinux_mapping *current_mapping;
102 static u16 current_mapping_size;
103
104 static int selinux_set_mapping(struct policydb *pol,
105                                struct security_class_mapping *map,
106                                struct selinux_mapping **out_map_p,
107                                u16 *out_map_size)
108 {
109         struct selinux_mapping *out_map = NULL;
110         size_t size = sizeof(struct selinux_mapping);
111         u16 i, j;
112         unsigned k;
113         bool print_unknown_handle = false;
114
115         /* Find number of classes in the input mapping */
116         if (!map)
117                 return -EINVAL;
118         i = 0;
119         while (map[i].name)
120                 i++;
121
122         /* Allocate space for the class records, plus one for class zero */
123         out_map = kcalloc(++i, size, GFP_ATOMIC);
124         if (!out_map)
125                 return -ENOMEM;
126
127         /* Store the raw class and permission values */
128         j = 0;
129         while (map[j].name) {
130                 struct security_class_mapping *p_in = map + (j++);
131                 struct selinux_mapping *p_out = out_map + j;
132
133                 /* An empty class string skips ahead */
134                 if (!strcmp(p_in->name, "")) {
135                         p_out->num_perms = 0;
136                         continue;
137                 }
138
139                 p_out->value = string_to_security_class(pol, p_in->name);
140                 if (!p_out->value) {
141                         printk(KERN_INFO
142                                "SELinux:  Class %s not defined in policy.\n",
143                                p_in->name);
144                         if (pol->reject_unknown)
145                                 goto err;
146                         p_out->num_perms = 0;
147                         print_unknown_handle = true;
148                         continue;
149                 }
150
151                 k = 0;
152                 while (p_in->perms && p_in->perms[k]) {
153                         /* An empty permission string skips ahead */
154                         if (!*p_in->perms[k]) {
155                                 k++;
156                                 continue;
157                         }
158                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
159                                                             p_in->perms[k]);
160                         if (!p_out->perms[k]) {
161                                 printk(KERN_INFO
162                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
163                                        p_in->perms[k], p_in->name);
164                                 if (pol->reject_unknown)
165                                         goto err;
166                                 print_unknown_handle = true;
167                         }
168
169                         k++;
170                 }
171                 p_out->num_perms = k;
172         }
173
174         if (print_unknown_handle)
175                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
176                        pol->allow_unknown ? "allowed" : "denied");
177
178         *out_map_p = out_map;
179         *out_map_size = i;
180         return 0;
181 err:
182         kfree(out_map);
183         return -EINVAL;
184 }
185
186 /*
187  * Get real, policy values from mapped values
188  */
189
190 static u16 unmap_class(u16 tclass)
191 {
192         if (tclass < current_mapping_size)
193                 return current_mapping[tclass].value;
194
195         return tclass;
196 }
197
198 static void map_decision(u16 tclass, struct av_decision *avd,
199                          int allow_unknown)
200 {
201         if (tclass < current_mapping_size) {
202                 unsigned i, n = current_mapping[tclass].num_perms;
203                 u32 result;
204
205                 for (i = 0, result = 0; i < n; i++) {
206                         if (avd->allowed & current_mapping[tclass].perms[i])
207                                 result |= 1<<i;
208                         if (allow_unknown && !current_mapping[tclass].perms[i])
209                                 result |= 1<<i;
210                 }
211                 avd->allowed = result;
212
213                 for (i = 0, result = 0; i < n; i++)
214                         if (avd->auditallow & current_mapping[tclass].perms[i])
215                                 result |= 1<<i;
216                 avd->auditallow = result;
217
218                 for (i = 0, result = 0; i < n; i++) {
219                         if (avd->auditdeny & current_mapping[tclass].perms[i])
220                                 result |= 1<<i;
221                         if (!allow_unknown && !current_mapping[tclass].perms[i])
222                                 result |= 1<<i;
223                 }
224                 /*
225                  * In case the kernel has a bug and requests a permission
226                  * between num_perms and the maximum permission number, we
227                  * should audit that denial
228                  */
229                 for (; i < (sizeof(u32)*8); i++)
230                         result |= 1<<i;
231                 avd->auditdeny = result;
232         }
233 }
234
235
236 /*
237  * Return the boolean value of a constraint expression
238  * when it is applied to the specified source and target
239  * security contexts.
240  *
241  * xcontext is a special beast...  It is used by the validatetrans rules
242  * only.  For these rules, scontext is the context before the transition,
243  * tcontext is the context after the transition, and xcontext is the context
244  * of the process performing the transition.  All other callers of
245  * constraint_expr_eval should pass in NULL for xcontext.
246  */
247 static int constraint_expr_eval(struct context *scontext,
248                                 struct context *tcontext,
249                                 struct context *xcontext,
250                                 struct constraint_expr *cexpr)
251 {
252         u32 val1, val2;
253         struct context *c;
254         struct role_datum *r1, *r2;
255         struct mls_level *l1, *l2;
256         struct constraint_expr *e;
257         int s[CEXPR_MAXDEPTH];
258         int sp = -1;
259
260         for (e = cexpr; e; e = e->next) {
261                 switch (e->expr_type) {
262                 case CEXPR_NOT:
263                         BUG_ON(sp < 0);
264                         s[sp] = !s[sp];
265                         break;
266                 case CEXPR_AND:
267                         BUG_ON(sp < 1);
268                         sp--;
269                         s[sp] &= s[sp+1];
270                         break;
271                 case CEXPR_OR:
272                         BUG_ON(sp < 1);
273                         sp--;
274                         s[sp] |= s[sp+1];
275                         break;
276                 case CEXPR_ATTR:
277                         if (sp == (CEXPR_MAXDEPTH-1))
278                                 return 0;
279                         switch (e->attr) {
280                         case CEXPR_USER:
281                                 val1 = scontext->user;
282                                 val2 = tcontext->user;
283                                 break;
284                         case CEXPR_TYPE:
285                                 val1 = scontext->type;
286                                 val2 = tcontext->type;
287                                 break;
288                         case CEXPR_ROLE:
289                                 val1 = scontext->role;
290                                 val2 = tcontext->role;
291                                 r1 = policydb.role_val_to_struct[val1 - 1];
292                                 r2 = policydb.role_val_to_struct[val2 - 1];
293                                 switch (e->op) {
294                                 case CEXPR_DOM:
295                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
296                                                                   val2 - 1);
297                                         continue;
298                                 case CEXPR_DOMBY:
299                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
300                                                                   val1 - 1);
301                                         continue;
302                                 case CEXPR_INCOMP:
303                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
304                                                                     val2 - 1) &&
305                                                    !ebitmap_get_bit(&r2->dominates,
306                                                                     val1 - 1));
307                                         continue;
308                                 default:
309                                         break;
310                                 }
311                                 break;
312                         case CEXPR_L1L2:
313                                 l1 = &(scontext->range.level[0]);
314                                 l2 = &(tcontext->range.level[0]);
315                                 goto mls_ops;
316                         case CEXPR_L1H2:
317                                 l1 = &(scontext->range.level[0]);
318                                 l2 = &(tcontext->range.level[1]);
319                                 goto mls_ops;
320                         case CEXPR_H1L2:
321                                 l1 = &(scontext->range.level[1]);
322                                 l2 = &(tcontext->range.level[0]);
323                                 goto mls_ops;
324                         case CEXPR_H1H2:
325                                 l1 = &(scontext->range.level[1]);
326                                 l2 = &(tcontext->range.level[1]);
327                                 goto mls_ops;
328                         case CEXPR_L1H1:
329                                 l1 = &(scontext->range.level[0]);
330                                 l2 = &(scontext->range.level[1]);
331                                 goto mls_ops;
332                         case CEXPR_L2H2:
333                                 l1 = &(tcontext->range.level[0]);
334                                 l2 = &(tcontext->range.level[1]);
335                                 goto mls_ops;
336 mls_ops:
337                         switch (e->op) {
338                         case CEXPR_EQ:
339                                 s[++sp] = mls_level_eq(l1, l2);
340                                 continue;
341                         case CEXPR_NEQ:
342                                 s[++sp] = !mls_level_eq(l1, l2);
343                                 continue;
344                         case CEXPR_DOM:
345                                 s[++sp] = mls_level_dom(l1, l2);
346                                 continue;
347                         case CEXPR_DOMBY:
348                                 s[++sp] = mls_level_dom(l2, l1);
349                                 continue;
350                         case CEXPR_INCOMP:
351                                 s[++sp] = mls_level_incomp(l2, l1);
352                                 continue;
353                         default:
354                                 BUG();
355                                 return 0;
356                         }
357                         break;
358                         default:
359                                 BUG();
360                                 return 0;
361                         }
362
363                         switch (e->op) {
364                         case CEXPR_EQ:
365                                 s[++sp] = (val1 == val2);
366                                 break;
367                         case CEXPR_NEQ:
368                                 s[++sp] = (val1 != val2);
369                                 break;
370                         default:
371                                 BUG();
372                                 return 0;
373                         }
374                         break;
375                 case CEXPR_NAMES:
376                         if (sp == (CEXPR_MAXDEPTH-1))
377                                 return 0;
378                         c = scontext;
379                         if (e->attr & CEXPR_TARGET)
380                                 c = tcontext;
381                         else if (e->attr & CEXPR_XTARGET) {
382                                 c = xcontext;
383                                 if (!c) {
384                                         BUG();
385                                         return 0;
386                                 }
387                         }
388                         if (e->attr & CEXPR_USER)
389                                 val1 = c->user;
390                         else if (e->attr & CEXPR_ROLE)
391                                 val1 = c->role;
392                         else if (e->attr & CEXPR_TYPE)
393                                 val1 = c->type;
394                         else {
395                                 BUG();
396                                 return 0;
397                         }
398
399                         switch (e->op) {
400                         case CEXPR_EQ:
401                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
402                                 break;
403                         case CEXPR_NEQ:
404                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
405                                 break;
406                         default:
407                                 BUG();
408                                 return 0;
409                         }
410                         break;
411                 default:
412                         BUG();
413                         return 0;
414                 }
415         }
416
417         BUG_ON(sp != 0);
418         return s[0];
419 }
420
421 /*
422  * security_dump_masked_av - dumps masked permissions during
423  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
424  */
425 static int dump_masked_av_helper(void *k, void *d, void *args)
426 {
427         struct perm_datum *pdatum = d;
428         char **permission_names = args;
429
430         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
431
432         permission_names[pdatum->value - 1] = (char *)k;
433
434         return 0;
435 }
436
437 static void security_dump_masked_av(struct context *scontext,
438                                     struct context *tcontext,
439                                     u16 tclass,
440                                     u32 permissions,
441                                     const char *reason)
442 {
443         struct common_datum *common_dat;
444         struct class_datum *tclass_dat;
445         struct audit_buffer *ab;
446         char *tclass_name;
447         char *scontext_name = NULL;
448         char *tcontext_name = NULL;
449         char *permission_names[32];
450         int index, length;
451         bool need_comma = false;
452
453         if (!permissions)
454                 return;
455
456         tclass_name = policydb.p_class_val_to_name[tclass - 1];
457         tclass_dat = policydb.class_val_to_struct[tclass - 1];
458         common_dat = tclass_dat->comdatum;
459
460         /* init permission_names */
461         if (common_dat &&
462             hashtab_map(common_dat->permissions.table,
463                         dump_masked_av_helper, permission_names) < 0)
464                 goto out;
465
466         if (hashtab_map(tclass_dat->permissions.table,
467                         dump_masked_av_helper, permission_names) < 0)
468                 goto out;
469
470         /* get scontext/tcontext in text form */
471         if (context_struct_to_string(scontext,
472                                      &scontext_name, &length) < 0)
473                 goto out;
474
475         if (context_struct_to_string(tcontext,
476                                      &tcontext_name, &length) < 0)
477                 goto out;
478
479         /* audit a message */
480         ab = audit_log_start(current->audit_context,
481                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
482         if (!ab)
483                 goto out;
484
485         audit_log_format(ab, "op=security_compute_av reason=%s "
486                          "scontext=%s tcontext=%s tclass=%s perms=",
487                          reason, scontext_name, tcontext_name, tclass_name);
488
489         for (index = 0; index < 32; index++) {
490                 u32 mask = (1 << index);
491
492                 if ((mask & permissions) == 0)
493                         continue;
494
495                 audit_log_format(ab, "%s%s",
496                                  need_comma ? "," : "",
497                                  permission_names[index]
498                                  ? permission_names[index] : "????");
499                 need_comma = true;
500         }
501         audit_log_end(ab);
502 out:
503         /* release scontext/tcontext */
504         kfree(tcontext_name);
505         kfree(scontext_name);
506
507         return;
508 }
509
510 /*
511  * security_boundary_permission - drops violated permissions
512  * on boundary constraint.
513  */
514 static void type_attribute_bounds_av(struct context *scontext,
515                                      struct context *tcontext,
516                                      u16 tclass,
517                                      struct av_decision *avd)
518 {
519         struct type_datum *source
520                 = policydb.type_val_to_struct[scontext->type - 1];
521
522         if (source->bounds) {
523                 struct context lo_scontext;
524                 struct av_decision lo_avd;
525                 u32 masked;
526
527                 memset(&lo_avd, 0, sizeof(lo_avd));
528
529                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
530                 lo_scontext.type = source->bounds;
531
532                 context_struct_compute_av(&lo_scontext,
533                                           tcontext,
534                                           tclass,
535                                           &lo_avd);
536                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
537                         return;         /* no masked permission */
538                 masked = ~lo_avd.allowed & avd->allowed;
539
540                 /* mask violated permissions */
541                 avd->allowed &= ~masked;
542
543                 /* audit masked permissions */
544                 security_dump_masked_av(scontext, tcontext,
545                                         tclass, masked, "bounds");
546         }
547 }
548
549 /*
550  * Compute access vectors based on a context structure pair for
551  * the permissions in a particular class.
552  */
553 static void context_struct_compute_av(struct context *scontext,
554                                       struct context *tcontext,
555                                       u16 tclass,
556                                       struct av_decision *avd)
557 {
558         struct constraint_node *constraint;
559         struct role_allow *ra;
560         struct avtab_key avkey;
561         struct avtab_node *node;
562         struct class_datum *tclass_datum;
563         struct ebitmap *sattr, *tattr;
564         struct ebitmap_node *snode, *tnode;
565         unsigned int i, j;
566
567         avd->allowed = 0;
568         avd->auditallow = 0;
569         avd->auditdeny = 0xffffffff;
570
571         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
572                 if (printk_ratelimit())
573                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
574                 return;
575         }
576
577         tclass_datum = policydb.class_val_to_struct[tclass - 1];
578
579         /*
580          * If a specific type enforcement rule was defined for
581          * this permission check, then use it.
582          */
583         avkey.target_class = tclass;
584         avkey.specified = AVTAB_AV;
585         sattr = &policydb.type_attr_map[scontext->type - 1];
586         tattr = &policydb.type_attr_map[tcontext->type - 1];
587         ebitmap_for_each_positive_bit(sattr, snode, i) {
588                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
589                         avkey.source_type = i + 1;
590                         avkey.target_type = j + 1;
591                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
592                              node;
593                              node = avtab_search_node_next(node, avkey.specified)) {
594                                 if (node->key.specified == AVTAB_ALLOWED)
595                                         avd->allowed |= node->datum.data;
596                                 else if (node->key.specified == AVTAB_AUDITALLOW)
597                                         avd->auditallow |= node->datum.data;
598                                 else if (node->key.specified == AVTAB_AUDITDENY)
599                                         avd->auditdeny &= node->datum.data;
600                         }
601
602                         /* Check conditional av table for additional permissions */
603                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
604
605                 }
606         }
607
608         /*
609          * Remove any permissions prohibited by a constraint (this includes
610          * the MLS policy).
611          */
612         constraint = tclass_datum->constraints;
613         while (constraint) {
614                 if ((constraint->permissions & (avd->allowed)) &&
615                     !constraint_expr_eval(scontext, tcontext, NULL,
616                                           constraint->expr)) {
617                         avd->allowed &= ~(constraint->permissions);
618                 }
619                 constraint = constraint->next;
620         }
621
622         /*
623          * If checking process transition permission and the
624          * role is changing, then check the (current_role, new_role)
625          * pair.
626          */
627         if (tclass == policydb.process_class &&
628             (avd->allowed & policydb.process_trans_perms) &&
629             scontext->role != tcontext->role) {
630                 for (ra = policydb.role_allow; ra; ra = ra->next) {
631                         if (scontext->role == ra->role &&
632                             tcontext->role == ra->new_role)
633                                 break;
634                 }
635                 if (!ra)
636                         avd->allowed &= ~policydb.process_trans_perms;
637         }
638
639         /*
640          * If the given source and target types have boundary
641          * constraint, lazy checks have to mask any violated
642          * permission and notice it to userspace via audit.
643          */
644         type_attribute_bounds_av(scontext, tcontext,
645                                  tclass, avd);
646 }
647
648 static int security_validtrans_handle_fail(struct context *ocontext,
649                                            struct context *ncontext,
650                                            struct context *tcontext,
651                                            u16 tclass)
652 {
653         char *o = NULL, *n = NULL, *t = NULL;
654         u32 olen, nlen, tlen;
655
656         if (context_struct_to_string(ocontext, &o, &olen) < 0)
657                 goto out;
658         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
659                 goto out;
660         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
661                 goto out;
662         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
663                   "security_validate_transition:  denied for"
664                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
665                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
666 out:
667         kfree(o);
668         kfree(n);
669         kfree(t);
670
671         if (!selinux_enforcing)
672                 return 0;
673         return -EPERM;
674 }
675
676 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
677                                  u16 orig_tclass)
678 {
679         struct context *ocontext;
680         struct context *ncontext;
681         struct context *tcontext;
682         struct class_datum *tclass_datum;
683         struct constraint_node *constraint;
684         u16 tclass;
685         int rc = 0;
686
687         if (!ss_initialized)
688                 return 0;
689
690         read_lock(&policy_rwlock);
691
692         tclass = unmap_class(orig_tclass);
693
694         if (!tclass || tclass > policydb.p_classes.nprim) {
695                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
696                         __func__, tclass);
697                 rc = -EINVAL;
698                 goto out;
699         }
700         tclass_datum = policydb.class_val_to_struct[tclass - 1];
701
702         ocontext = sidtab_search(&sidtab, oldsid);
703         if (!ocontext) {
704                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
705                         __func__, oldsid);
706                 rc = -EINVAL;
707                 goto out;
708         }
709
710         ncontext = sidtab_search(&sidtab, newsid);
711         if (!ncontext) {
712                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
713                         __func__, newsid);
714                 rc = -EINVAL;
715                 goto out;
716         }
717
718         tcontext = sidtab_search(&sidtab, tasksid);
719         if (!tcontext) {
720                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
721                         __func__, tasksid);
722                 rc = -EINVAL;
723                 goto out;
724         }
725
726         constraint = tclass_datum->validatetrans;
727         while (constraint) {
728                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
729                                           constraint->expr)) {
730                         rc = security_validtrans_handle_fail(ocontext, ncontext,
731                                                              tcontext, tclass);
732                         goto out;
733                 }
734                 constraint = constraint->next;
735         }
736
737 out:
738         read_unlock(&policy_rwlock);
739         return rc;
740 }
741
742 /*
743  * security_bounded_transition - check whether the given
744  * transition is directed to bounded, or not.
745  * It returns 0, if @newsid is bounded by @oldsid.
746  * Otherwise, it returns error code.
747  *
748  * @oldsid : current security identifier
749  * @newsid : destinated security identifier
750  */
751 int security_bounded_transition(u32 old_sid, u32 new_sid)
752 {
753         struct context *old_context, *new_context;
754         struct type_datum *type;
755         int index;
756         int rc = -EINVAL;
757
758         read_lock(&policy_rwlock);
759
760         old_context = sidtab_search(&sidtab, old_sid);
761         if (!old_context) {
762                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
763                        __func__, old_sid);
764                 goto out;
765         }
766
767         new_context = sidtab_search(&sidtab, new_sid);
768         if (!new_context) {
769                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
770                        __func__, new_sid);
771                 goto out;
772         }
773
774         /* type/domain unchanged */
775         if (old_context->type == new_context->type) {
776                 rc = 0;
777                 goto out;
778         }
779
780         index = new_context->type;
781         while (true) {
782                 type = policydb.type_val_to_struct[index - 1];
783                 BUG_ON(!type);
784
785                 /* not bounded anymore */
786                 if (!type->bounds) {
787                         rc = -EPERM;
788                         break;
789                 }
790
791                 /* @newsid is bounded by @oldsid */
792                 if (type->bounds == old_context->type) {
793                         rc = 0;
794                         break;
795                 }
796                 index = type->bounds;
797         }
798
799         if (rc) {
800                 char *old_name = NULL;
801                 char *new_name = NULL;
802                 int length;
803
804                 if (!context_struct_to_string(old_context,
805                                               &old_name, &length) &&
806                     !context_struct_to_string(new_context,
807                                               &new_name, &length)) {
808                         audit_log(current->audit_context,
809                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
810                                   "op=security_bounded_transition "
811                                   "result=denied "
812                                   "oldcontext=%s newcontext=%s",
813                                   old_name, new_name);
814                 }
815                 kfree(new_name);
816                 kfree(old_name);
817         }
818 out:
819         read_unlock(&policy_rwlock);
820
821         return rc;
822 }
823
824 static void avd_init(struct av_decision *avd)
825 {
826         avd->allowed = 0;
827         avd->auditallow = 0;
828         avd->auditdeny = 0xffffffff;
829         avd->seqno = latest_granting;
830         avd->flags = 0;
831 }
832
833
834 /**
835  * security_compute_av - Compute access vector decisions.
836  * @ssid: source security identifier
837  * @tsid: target security identifier
838  * @tclass: target security class
839  * @avd: access vector decisions
840  *
841  * Compute a set of access vector decisions based on the
842  * SID pair (@ssid, @tsid) for the permissions in @tclass.
843  */
844 void security_compute_av(u32 ssid,
845                          u32 tsid,
846                          u16 orig_tclass,
847                          struct av_decision *avd)
848 {
849         u16 tclass;
850         struct context *scontext = NULL, *tcontext = NULL;
851
852         read_lock(&policy_rwlock);
853         avd_init(avd);
854         if (!ss_initialized)
855                 goto allow;
856
857         scontext = sidtab_search(&sidtab, ssid);
858         if (!scontext) {
859                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
860                        __func__, ssid);
861                 goto out;
862         }
863
864         /* permissive domain? */
865         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
866                 avd->flags |= AVD_FLAGS_PERMISSIVE;
867
868         tcontext = sidtab_search(&sidtab, tsid);
869         if (!tcontext) {
870                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
871                        __func__, tsid);
872                 goto out;
873         }
874
875         tclass = unmap_class(orig_tclass);
876         if (unlikely(orig_tclass && !tclass)) {
877                 if (policydb.allow_unknown)
878                         goto allow;
879                 goto out;
880         }
881         context_struct_compute_av(scontext, tcontext, tclass, avd);
882         map_decision(orig_tclass, avd, policydb.allow_unknown);
883 out:
884         read_unlock(&policy_rwlock);
885         return;
886 allow:
887         avd->allowed = 0xffffffff;
888         goto out;
889 }
890
891 void security_compute_av_user(u32 ssid,
892                               u32 tsid,
893                               u16 tclass,
894                               struct av_decision *avd)
895 {
896         struct context *scontext = NULL, *tcontext = NULL;
897
898         read_lock(&policy_rwlock);
899         avd_init(avd);
900         if (!ss_initialized)
901                 goto allow;
902
903         scontext = sidtab_search(&sidtab, ssid);
904         if (!scontext) {
905                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
906                        __func__, ssid);
907                 goto out;
908         }
909
910         /* permissive domain? */
911         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
912                 avd->flags |= AVD_FLAGS_PERMISSIVE;
913
914         tcontext = sidtab_search(&sidtab, tsid);
915         if (!tcontext) {
916                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
917                        __func__, tsid);
918                 goto out;
919         }
920
921         if (unlikely(!tclass)) {
922                 if (policydb.allow_unknown)
923                         goto allow;
924                 goto out;
925         }
926
927         context_struct_compute_av(scontext, tcontext, tclass, avd);
928  out:
929         read_unlock(&policy_rwlock);
930         return;
931 allow:
932         avd->allowed = 0xffffffff;
933         goto out;
934 }
935
936 /*
937  * Write the security context string representation of
938  * the context structure `context' into a dynamically
939  * allocated string of the correct size.  Set `*scontext'
940  * to point to this string and set `*scontext_len' to
941  * the length of the string.
942  */
943 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
944 {
945         char *scontextp;
946
947         *scontext = NULL;
948         *scontext_len = 0;
949
950         if (context->len) {
951                 *scontext_len = context->len;
952                 *scontext = kstrdup(context->str, GFP_ATOMIC);
953                 if (!(*scontext))
954                         return -ENOMEM;
955                 return 0;
956         }
957
958         /* Compute the size of the context. */
959         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
960         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
961         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
962         *scontext_len += mls_compute_context_len(context);
963
964         /* Allocate space for the context; caller must free this space. */
965         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
966         if (!scontextp)
967                 return -ENOMEM;
968         *scontext = scontextp;
969
970         /*
971          * Copy the user name, role name and type name into the context.
972          */
973         sprintf(scontextp, "%s:%s:%s",
974                 policydb.p_user_val_to_name[context->user - 1],
975                 policydb.p_role_val_to_name[context->role - 1],
976                 policydb.p_type_val_to_name[context->type - 1]);
977         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
978                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
979                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
980
981         mls_sid_to_context(context, &scontextp);
982
983         *scontextp = 0;
984
985         return 0;
986 }
987
988 #include "initial_sid_to_string.h"
989
990 const char *security_get_initial_sid_context(u32 sid)
991 {
992         if (unlikely(sid > SECINITSID_NUM))
993                 return NULL;
994         return initial_sid_to_string[sid];
995 }
996
997 static int security_sid_to_context_core(u32 sid, char **scontext,
998                                         u32 *scontext_len, int force)
999 {
1000         struct context *context;
1001         int rc = 0;
1002
1003         *scontext = NULL;
1004         *scontext_len  = 0;
1005
1006         if (!ss_initialized) {
1007                 if (sid <= SECINITSID_NUM) {
1008                         char *scontextp;
1009
1010                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1011                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1012                         if (!scontextp) {
1013                                 rc = -ENOMEM;
1014                                 goto out;
1015                         }
1016                         strcpy(scontextp, initial_sid_to_string[sid]);
1017                         *scontext = scontextp;
1018                         goto out;
1019                 }
1020                 printk(KERN_ERR "SELinux: %s:  called before initial "
1021                        "load_policy on unknown SID %d\n", __func__, sid);
1022                 rc = -EINVAL;
1023                 goto out;
1024         }
1025         read_lock(&policy_rwlock);
1026         if (force)
1027                 context = sidtab_search_force(&sidtab, sid);
1028         else
1029                 context = sidtab_search(&sidtab, sid);
1030         if (!context) {
1031                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1032                         __func__, sid);
1033                 rc = -EINVAL;
1034                 goto out_unlock;
1035         }
1036         rc = context_struct_to_string(context, scontext, scontext_len);
1037 out_unlock:
1038         read_unlock(&policy_rwlock);
1039 out:
1040         return rc;
1041
1042 }
1043
1044 /**
1045  * security_sid_to_context - Obtain a context for a given SID.
1046  * @sid: security identifier, SID
1047  * @scontext: security context
1048  * @scontext_len: length in bytes
1049  *
1050  * Write the string representation of the context associated with @sid
1051  * into a dynamically allocated string of the correct size.  Set @scontext
1052  * to point to this string and set @scontext_len to the length of the string.
1053  */
1054 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1055 {
1056         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1057 }
1058
1059 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1060 {
1061         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1062 }
1063
1064 /*
1065  * Caveat:  Mutates scontext.
1066  */
1067 static int string_to_context_struct(struct policydb *pol,
1068                                     struct sidtab *sidtabp,
1069                                     char *scontext,
1070                                     u32 scontext_len,
1071                                     struct context *ctx,
1072                                     u32 def_sid)
1073 {
1074         struct role_datum *role;
1075         struct type_datum *typdatum;
1076         struct user_datum *usrdatum;
1077         char *scontextp, *p, oldc;
1078         int rc = 0;
1079
1080         context_init(ctx);
1081
1082         /* Parse the security context. */
1083
1084         rc = -EINVAL;
1085         scontextp = (char *) scontext;
1086
1087         /* Extract the user. */
1088         p = scontextp;
1089         while (*p && *p != ':')
1090                 p++;
1091
1092         if (*p == 0)
1093                 goto out;
1094
1095         *p++ = 0;
1096
1097         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1098         if (!usrdatum)
1099                 goto out;
1100
1101         ctx->user = usrdatum->value;
1102
1103         /* Extract role. */
1104         scontextp = p;
1105         while (*p && *p != ':')
1106                 p++;
1107
1108         if (*p == 0)
1109                 goto out;
1110
1111         *p++ = 0;
1112
1113         role = hashtab_search(pol->p_roles.table, scontextp);
1114         if (!role)
1115                 goto out;
1116         ctx->role = role->value;
1117
1118         /* Extract type. */
1119         scontextp = p;
1120         while (*p && *p != ':')
1121                 p++;
1122         oldc = *p;
1123         *p++ = 0;
1124
1125         typdatum = hashtab_search(pol->p_types.table, scontextp);
1126         if (!typdatum || typdatum->attribute)
1127                 goto out;
1128
1129         ctx->type = typdatum->value;
1130
1131         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1132         if (rc)
1133                 goto out;
1134
1135         if ((p - scontext) < scontext_len) {
1136                 rc = -EINVAL;
1137                 goto out;
1138         }
1139
1140         /* Check the validity of the new context. */
1141         if (!policydb_context_isvalid(pol, ctx)) {
1142                 rc = -EINVAL;
1143                 goto out;
1144         }
1145         rc = 0;
1146 out:
1147         if (rc)
1148                 context_destroy(ctx);
1149         return rc;
1150 }
1151
1152 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1153                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1154                                         int force)
1155 {
1156         char *scontext2, *str = NULL;
1157         struct context context;
1158         int rc = 0;
1159
1160         if (!ss_initialized) {
1161                 int i;
1162
1163                 for (i = 1; i < SECINITSID_NUM; i++) {
1164                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1165                                 *sid = i;
1166                                 return 0;
1167                         }
1168                 }
1169                 *sid = SECINITSID_KERNEL;
1170                 return 0;
1171         }
1172         *sid = SECSID_NULL;
1173
1174         /* Copy the string so that we can modify the copy as we parse it. */
1175         scontext2 = kmalloc(scontext_len+1, gfp_flags);
1176         if (!scontext2)
1177                 return -ENOMEM;
1178         memcpy(scontext2, scontext, scontext_len);
1179         scontext2[scontext_len] = 0;
1180
1181         if (force) {
1182                 /* Save another copy for storing in uninterpreted form */
1183                 str = kstrdup(scontext2, gfp_flags);
1184                 if (!str) {
1185                         kfree(scontext2);
1186                         return -ENOMEM;
1187                 }
1188         }
1189
1190         read_lock(&policy_rwlock);
1191         rc = string_to_context_struct(&policydb, &sidtab,
1192                                       scontext2, scontext_len,
1193                                       &context, def_sid);
1194         if (rc == -EINVAL && force) {
1195                 context.str = str;
1196                 context.len = scontext_len;
1197                 str = NULL;
1198         } else if (rc)
1199                 goto out;
1200         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1201         context_destroy(&context);
1202 out:
1203         read_unlock(&policy_rwlock);
1204         kfree(scontext2);
1205         kfree(str);
1206         return rc;
1207 }
1208
1209 /**
1210  * security_context_to_sid - Obtain a SID for a given security context.
1211  * @scontext: security context
1212  * @scontext_len: length in bytes
1213  * @sid: security identifier, SID
1214  *
1215  * Obtains a SID associated with the security context that
1216  * has the string representation specified by @scontext.
1217  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1218  * memory is available, or 0 on success.
1219  */
1220 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1221 {
1222         return security_context_to_sid_core(scontext, scontext_len,
1223                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1224 }
1225
1226 /**
1227  * security_context_to_sid_default - Obtain a SID for a given security context,
1228  * falling back to specified default if needed.
1229  *
1230  * @scontext: security context
1231  * @scontext_len: length in bytes
1232  * @sid: security identifier, SID
1233  * @def_sid: default SID to assign on error
1234  *
1235  * Obtains a SID associated with the security context that
1236  * has the string representation specified by @scontext.
1237  * The default SID is passed to the MLS layer to be used to allow
1238  * kernel labeling of the MLS field if the MLS field is not present
1239  * (for upgrading to MLS without full relabel).
1240  * Implicitly forces adding of the context even if it cannot be mapped yet.
1241  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1242  * memory is available, or 0 on success.
1243  */
1244 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1245                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1246 {
1247         return security_context_to_sid_core(scontext, scontext_len,
1248                                             sid, def_sid, gfp_flags, 1);
1249 }
1250
1251 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1252                                   u32 *sid)
1253 {
1254         return security_context_to_sid_core(scontext, scontext_len,
1255                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1256 }
1257
1258 static int compute_sid_handle_invalid_context(
1259         struct context *scontext,
1260         struct context *tcontext,
1261         u16 tclass,
1262         struct context *newcontext)
1263 {
1264         char *s = NULL, *t = NULL, *n = NULL;
1265         u32 slen, tlen, nlen;
1266
1267         if (context_struct_to_string(scontext, &s, &slen) < 0)
1268                 goto out;
1269         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
1270                 goto out;
1271         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
1272                 goto out;
1273         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1274                   "security_compute_sid:  invalid context %s"
1275                   " for scontext=%s"
1276                   " tcontext=%s"
1277                   " tclass=%s",
1278                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
1279 out:
1280         kfree(s);
1281         kfree(t);
1282         kfree(n);
1283         if (!selinux_enforcing)
1284                 return 0;
1285         return -EACCES;
1286 }
1287
1288 static int security_compute_sid(u32 ssid,
1289                                 u32 tsid,
1290                                 u16 orig_tclass,
1291                                 u32 specified,
1292                                 u32 *out_sid,
1293                                 bool kern)
1294 {
1295         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1296         struct role_trans *roletr = NULL;
1297         struct avtab_key avkey;
1298         struct avtab_datum *avdatum;
1299         struct avtab_node *node;
1300         u16 tclass;
1301         int rc = 0;
1302
1303         if (!ss_initialized) {
1304                 switch (orig_tclass) {
1305                 case SECCLASS_PROCESS: /* kernel value */
1306                         *out_sid = ssid;
1307                         break;
1308                 default:
1309                         *out_sid = tsid;
1310                         break;
1311                 }
1312                 goto out;
1313         }
1314
1315         context_init(&newcontext);
1316
1317         read_lock(&policy_rwlock);
1318
1319         if (kern)
1320                 tclass = unmap_class(orig_tclass);
1321         else
1322                 tclass = orig_tclass;
1323
1324         scontext = sidtab_search(&sidtab, ssid);
1325         if (!scontext) {
1326                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1327                        __func__, ssid);
1328                 rc = -EINVAL;
1329                 goto out_unlock;
1330         }
1331         tcontext = sidtab_search(&sidtab, tsid);
1332         if (!tcontext) {
1333                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1334                        __func__, tsid);
1335                 rc = -EINVAL;
1336                 goto out_unlock;
1337         }
1338
1339         /* Set the user identity. */
1340         switch (specified) {
1341         case AVTAB_TRANSITION:
1342         case AVTAB_CHANGE:
1343                 /* Use the process user identity. */
1344                 newcontext.user = scontext->user;
1345                 break;
1346         case AVTAB_MEMBER:
1347                 /* Use the related object owner. */
1348                 newcontext.user = tcontext->user;
1349                 break;
1350         }
1351
1352         /* Set the role and type to default values. */
1353         if (tclass == policydb.process_class) {
1354                 /* Use the current role and type of process. */
1355                 newcontext.role = scontext->role;
1356                 newcontext.type = scontext->type;
1357         } else {
1358                 /* Use the well-defined object role. */
1359                 newcontext.role = OBJECT_R_VAL;
1360                 /* Use the type of the related object. */
1361                 newcontext.type = tcontext->type;
1362         }
1363
1364         /* Look for a type transition/member/change rule. */
1365         avkey.source_type = scontext->type;
1366         avkey.target_type = tcontext->type;
1367         avkey.target_class = tclass;
1368         avkey.specified = specified;
1369         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1370
1371         /* If no permanent rule, also check for enabled conditional rules */
1372         if (!avdatum) {
1373                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1374                 for (; node; node = avtab_search_node_next(node, specified)) {
1375                         if (node->key.specified & AVTAB_ENABLED) {
1376                                 avdatum = &node->datum;
1377                                 break;
1378                         }
1379                 }
1380         }
1381
1382         if (avdatum) {
1383                 /* Use the type from the type transition/member/change rule. */
1384                 newcontext.type = avdatum->data;
1385         }
1386
1387         /* Check for class-specific changes. */
1388         if  (tclass == policydb.process_class) {
1389                 if (specified & AVTAB_TRANSITION) {
1390                         /* Look for a role transition rule. */
1391                         for (roletr = policydb.role_tr; roletr;
1392                              roletr = roletr->next) {
1393                                 if (roletr->role == scontext->role &&
1394                                     roletr->type == tcontext->type) {
1395                                         /* Use the role transition rule. */
1396                                         newcontext.role = roletr->new_role;
1397                                         break;
1398                                 }
1399                         }
1400                 }
1401         }
1402
1403         /* Set the MLS attributes.
1404            This is done last because it may allocate memory. */
1405         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1406         if (rc)
1407                 goto out_unlock;
1408
1409         /* Check the validity of the context. */
1410         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1411                 rc = compute_sid_handle_invalid_context(scontext,
1412                                                         tcontext,
1413                                                         tclass,
1414                                                         &newcontext);
1415                 if (rc)
1416                         goto out_unlock;
1417         }
1418         /* Obtain the sid for the context. */
1419         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1420 out_unlock:
1421         read_unlock(&policy_rwlock);
1422         context_destroy(&newcontext);
1423 out:
1424         return rc;
1425 }
1426
1427 /**
1428  * security_transition_sid - Compute the SID for a new subject/object.
1429  * @ssid: source security identifier
1430  * @tsid: target security identifier
1431  * @tclass: target security class
1432  * @out_sid: security identifier for new subject/object
1433  *
1434  * Compute a SID to use for labeling a new subject or object in the
1435  * class @tclass based on a SID pair (@ssid, @tsid).
1436  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1437  * if insufficient memory is available, or %0 if the new SID was
1438  * computed successfully.
1439  */
1440 int security_transition_sid(u32 ssid,
1441                             u32 tsid,
1442                             u16 tclass,
1443                             u32 *out_sid)
1444 {
1445         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1446                                     out_sid, true);
1447 }
1448
1449 int security_transition_sid_user(u32 ssid,
1450                                  u32 tsid,
1451                                  u16 tclass,
1452                                  u32 *out_sid)
1453 {
1454         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1455                                     out_sid, false);
1456 }
1457
1458 /**
1459  * security_member_sid - Compute the SID for member selection.
1460  * @ssid: source security identifier
1461  * @tsid: target security identifier
1462  * @tclass: target security class
1463  * @out_sid: security identifier for selected member
1464  *
1465  * Compute a SID to use when selecting a member of a polyinstantiated
1466  * object of class @tclass based on a SID pair (@ssid, @tsid).
1467  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1468  * if insufficient memory is available, or %0 if the SID was
1469  * computed successfully.
1470  */
1471 int security_member_sid(u32 ssid,
1472                         u32 tsid,
1473                         u16 tclass,
1474                         u32 *out_sid)
1475 {
1476         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid,
1477                                     false);
1478 }
1479
1480 /**
1481  * security_change_sid - Compute the SID for object relabeling.
1482  * @ssid: source security identifier
1483  * @tsid: target security identifier
1484  * @tclass: target security class
1485  * @out_sid: security identifier for selected member
1486  *
1487  * Compute a SID to use for relabeling an object of class @tclass
1488  * based on a SID pair (@ssid, @tsid).
1489  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1490  * if insufficient memory is available, or %0 if the SID was
1491  * computed successfully.
1492  */
1493 int security_change_sid(u32 ssid,
1494                         u32 tsid,
1495                         u16 tclass,
1496                         u32 *out_sid)
1497 {
1498         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid,
1499                                     false);
1500 }
1501
1502 /* Clone the SID into the new SID table. */
1503 static int clone_sid(u32 sid,
1504                      struct context *context,
1505                      void *arg)
1506 {
1507         struct sidtab *s = arg;
1508
1509         if (sid > SECINITSID_NUM)
1510                 return sidtab_insert(s, sid, context);
1511         else
1512                 return 0;
1513 }
1514
1515 static inline int convert_context_handle_invalid_context(struct context *context)
1516 {
1517         int rc = 0;
1518
1519         if (selinux_enforcing) {
1520                 rc = -EINVAL;
1521         } else {
1522                 char *s;
1523                 u32 len;
1524
1525                 if (!context_struct_to_string(context, &s, &len)) {
1526                         printk(KERN_WARNING
1527                        "SELinux:  Context %s would be invalid if enforcing\n",
1528                                s);
1529                         kfree(s);
1530                 }
1531         }
1532         return rc;
1533 }
1534
1535 struct convert_context_args {
1536         struct policydb *oldp;
1537         struct policydb *newp;
1538 };
1539
1540 /*
1541  * Convert the values in the security context
1542  * structure `c' from the values specified
1543  * in the policy `p->oldp' to the values specified
1544  * in the policy `p->newp'.  Verify that the
1545  * context is valid under the new policy.
1546  */
1547 static int convert_context(u32 key,
1548                            struct context *c,
1549                            void *p)
1550 {
1551         struct convert_context_args *args;
1552         struct context oldc;
1553         struct role_datum *role;
1554         struct type_datum *typdatum;
1555         struct user_datum *usrdatum;
1556         char *s;
1557         u32 len;
1558         int rc = 0;
1559
1560         if (key <= SECINITSID_NUM)
1561                 goto out;
1562
1563         args = p;
1564
1565         if (c->str) {
1566                 struct context ctx;
1567                 s = kstrdup(c->str, GFP_KERNEL);
1568                 if (!s) {
1569                         rc = -ENOMEM;
1570                         goto out;
1571                 }
1572                 rc = string_to_context_struct(args->newp, NULL, s,
1573                                               c->len, &ctx, SECSID_NULL);
1574                 kfree(s);
1575                 if (!rc) {
1576                         printk(KERN_INFO
1577                        "SELinux:  Context %s became valid (mapped).\n",
1578                                c->str);
1579                         /* Replace string with mapped representation. */
1580                         kfree(c->str);
1581                         memcpy(c, &ctx, sizeof(*c));
1582                         goto out;
1583                 } else if (rc == -EINVAL) {
1584                         /* Retain string representation for later mapping. */
1585                         rc = 0;
1586                         goto out;
1587                 } else {
1588                         /* Other error condition, e.g. ENOMEM. */
1589                         printk(KERN_ERR
1590                        "SELinux:   Unable to map context %s, rc = %d.\n",
1591                                c->str, -rc);
1592                         goto out;
1593                 }
1594         }
1595
1596         rc = context_cpy(&oldc, c);
1597         if (rc)
1598                 goto out;
1599
1600         rc = -EINVAL;
1601
1602         /* Convert the user. */
1603         usrdatum = hashtab_search(args->newp->p_users.table,
1604                                   args->oldp->p_user_val_to_name[c->user - 1]);
1605         if (!usrdatum)
1606                 goto bad;
1607         c->user = usrdatum->value;
1608
1609         /* Convert the role. */
1610         role = hashtab_search(args->newp->p_roles.table,
1611                               args->oldp->p_role_val_to_name[c->role - 1]);
1612         if (!role)
1613                 goto bad;
1614         c->role = role->value;
1615
1616         /* Convert the type. */
1617         typdatum = hashtab_search(args->newp->p_types.table,
1618                                   args->oldp->p_type_val_to_name[c->type - 1]);
1619         if (!typdatum)
1620                 goto bad;
1621         c->type = typdatum->value;
1622
1623         rc = mls_convert_context(args->oldp, args->newp, c);
1624         if (rc)
1625                 goto bad;
1626
1627         /* Check the validity of the new context. */
1628         if (!policydb_context_isvalid(args->newp, c)) {
1629                 rc = convert_context_handle_invalid_context(&oldc);
1630                 if (rc)
1631                         goto bad;
1632         }
1633
1634         context_destroy(&oldc);
1635         rc = 0;
1636 out:
1637         return rc;
1638 bad:
1639         /* Map old representation to string and save it. */
1640         if (context_struct_to_string(&oldc, &s, &len))
1641                 return -ENOMEM;
1642         context_destroy(&oldc);
1643         context_destroy(c);
1644         c->str = s;
1645         c->len = len;
1646         printk(KERN_INFO
1647                "SELinux:  Context %s became invalid (unmapped).\n",
1648                c->str);
1649         rc = 0;
1650         goto out;
1651 }
1652
1653 static void security_load_policycaps(void)
1654 {
1655         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1656                                                   POLICYDB_CAPABILITY_NETPEER);
1657         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1658                                                   POLICYDB_CAPABILITY_OPENPERM);
1659 }
1660
1661 extern void selinux_complete_init(void);
1662 static int security_preserve_bools(struct policydb *p);
1663
1664 /**
1665  * security_load_policy - Load a security policy configuration.
1666  * @data: binary policy data
1667  * @len: length of data in bytes
1668  *
1669  * Load a new set of security policy configuration data,
1670  * validate it and convert the SID table as necessary.
1671  * This function will flush the access vector cache after
1672  * loading the new policy.
1673  */
1674 int security_load_policy(void *data, size_t len)
1675 {
1676         struct policydb oldpolicydb, newpolicydb;
1677         struct sidtab oldsidtab, newsidtab;
1678         struct selinux_mapping *oldmap, *map = NULL;
1679         struct convert_context_args args;
1680         u32 seqno;
1681         u16 map_size;
1682         int rc = 0;
1683         struct policy_file file = { data, len }, *fp = &file;
1684
1685         if (!ss_initialized) {
1686                 avtab_cache_init();
1687                 if (policydb_read(&policydb, fp)) {
1688                         avtab_cache_destroy();
1689                         return -EINVAL;
1690                 }
1691                 if (selinux_set_mapping(&policydb, secclass_map,
1692                                         &current_mapping,
1693                                         &current_mapping_size)) {
1694                         policydb_destroy(&policydb);
1695                         avtab_cache_destroy();
1696                         return -EINVAL;
1697                 }
1698                 if (policydb_load_isids(&policydb, &sidtab)) {
1699                         policydb_destroy(&policydb);
1700                         avtab_cache_destroy();
1701                         return -EINVAL;
1702                 }
1703                 security_load_policycaps();
1704                 ss_initialized = 1;
1705                 seqno = ++latest_granting;
1706                 selinux_complete_init();
1707                 avc_ss_reset(seqno);
1708                 selnl_notify_policyload(seqno);
1709                 selinux_netlbl_cache_invalidate();
1710                 selinux_xfrm_notify_policyload();
1711                 return 0;
1712         }
1713
1714 #if 0
1715         sidtab_hash_eval(&sidtab, "sids");
1716 #endif
1717
1718         if (policydb_read(&newpolicydb, fp))
1719                 return -EINVAL;
1720
1721         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1722         if (rc) {
1723                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1724                 policydb_destroy(&newpolicydb);
1725                 return rc;
1726         }
1727
1728         if (selinux_set_mapping(&newpolicydb, secclass_map,
1729                                 &map, &map_size))
1730                 goto err;
1731
1732         rc = security_preserve_bools(&newpolicydb);
1733         if (rc) {
1734                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1735                 goto err;
1736         }
1737
1738         /* Clone the SID table. */
1739         sidtab_shutdown(&sidtab);
1740         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1741                 rc = -ENOMEM;
1742                 goto err;
1743         }
1744
1745         /*
1746          * Convert the internal representations of contexts
1747          * in the new SID table.
1748          */
1749         args.oldp = &policydb;
1750         args.newp = &newpolicydb;
1751         rc = sidtab_map(&newsidtab, convert_context, &args);
1752         if (rc)
1753                 goto err;
1754
1755         /* Save the old policydb and SID table to free later. */
1756         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1757         sidtab_set(&oldsidtab, &sidtab);
1758
1759         /* Install the new policydb and SID table. */
1760         write_lock_irq(&policy_rwlock);
1761         memcpy(&policydb, &newpolicydb, sizeof policydb);
1762         sidtab_set(&sidtab, &newsidtab);
1763         security_load_policycaps();
1764         oldmap = current_mapping;
1765         current_mapping = map;
1766         current_mapping_size = map_size;
1767         seqno = ++latest_granting;
1768         write_unlock_irq(&policy_rwlock);
1769
1770         /* Free the old policydb and SID table. */
1771         policydb_destroy(&oldpolicydb);
1772         sidtab_destroy(&oldsidtab);
1773         kfree(oldmap);
1774
1775         avc_ss_reset(seqno);
1776         selnl_notify_policyload(seqno);
1777         selinux_netlbl_cache_invalidate();
1778         selinux_xfrm_notify_policyload();
1779
1780         return 0;
1781
1782 err:
1783         kfree(map);
1784         sidtab_destroy(&newsidtab);
1785         policydb_destroy(&newpolicydb);
1786         return rc;
1787
1788 }
1789
1790 /**
1791  * security_port_sid - Obtain the SID for a port.
1792  * @protocol: protocol number
1793  * @port: port number
1794  * @out_sid: security identifier
1795  */
1796 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1797 {
1798         struct ocontext *c;
1799         int rc = 0;
1800
1801         read_lock(&policy_rwlock);
1802
1803         c = policydb.ocontexts[OCON_PORT];
1804         while (c) {
1805                 if (c->u.port.protocol == protocol &&
1806                     c->u.port.low_port <= port &&
1807                     c->u.port.high_port >= port)
1808                         break;
1809                 c = c->next;
1810         }
1811
1812         if (c) {
1813                 if (!c->sid[0]) {
1814                         rc = sidtab_context_to_sid(&sidtab,
1815                                                    &c->context[0],
1816                                                    &c->sid[0]);
1817                         if (rc)
1818                                 goto out;
1819                 }
1820                 *out_sid = c->sid[0];
1821         } else {
1822                 *out_sid = SECINITSID_PORT;
1823         }
1824
1825 out:
1826         read_unlock(&policy_rwlock);
1827         return rc;
1828 }
1829
1830 /**
1831  * security_netif_sid - Obtain the SID for a network interface.
1832  * @name: interface name
1833  * @if_sid: interface SID
1834  */
1835 int security_netif_sid(char *name, u32 *if_sid)
1836 {
1837         int rc = 0;
1838         struct ocontext *c;
1839
1840         read_lock(&policy_rwlock);
1841
1842         c = policydb.ocontexts[OCON_NETIF];
1843         while (c) {
1844                 if (strcmp(name, c->u.name) == 0)
1845                         break;
1846                 c = c->next;
1847         }
1848
1849         if (c) {
1850                 if (!c->sid[0] || !c->sid[1]) {
1851                         rc = sidtab_context_to_sid(&sidtab,
1852                                                   &c->context[0],
1853                                                   &c->sid[0]);
1854                         if (rc)
1855                                 goto out;
1856                         rc = sidtab_context_to_sid(&sidtab,
1857                                                    &c->context[1],
1858                                                    &c->sid[1]);
1859                         if (rc)
1860                                 goto out;
1861                 }
1862                 *if_sid = c->sid[0];
1863         } else
1864                 *if_sid = SECINITSID_NETIF;
1865
1866 out:
1867         read_unlock(&policy_rwlock);
1868         return rc;
1869 }
1870
1871 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1872 {
1873         int i, fail = 0;
1874
1875         for (i = 0; i < 4; i++)
1876                 if (addr[i] != (input[i] & mask[i])) {
1877                         fail = 1;
1878                         break;
1879                 }
1880
1881         return !fail;
1882 }
1883
1884 /**
1885  * security_node_sid - Obtain the SID for a node (host).
1886  * @domain: communication domain aka address family
1887  * @addrp: address
1888  * @addrlen: address length in bytes
1889  * @out_sid: security identifier
1890  */
1891 int security_node_sid(u16 domain,
1892                       void *addrp,
1893                       u32 addrlen,
1894                       u32 *out_sid)
1895 {
1896         int rc = 0;
1897         struct ocontext *c;
1898
1899         read_lock(&policy_rwlock);
1900
1901         switch (domain) {
1902         case AF_INET: {
1903                 u32 addr;
1904
1905                 if (addrlen != sizeof(u32)) {
1906                         rc = -EINVAL;
1907                         goto out;
1908                 }
1909
1910                 addr = *((u32 *)addrp);
1911
1912                 c = policydb.ocontexts[OCON_NODE];
1913                 while (c) {
1914                         if (c->u.node.addr == (addr & c->u.node.mask))
1915                                 break;
1916                         c = c->next;
1917                 }
1918                 break;
1919         }
1920
1921         case AF_INET6:
1922                 if (addrlen != sizeof(u64) * 2) {
1923                         rc = -EINVAL;
1924                         goto out;
1925                 }
1926                 c = policydb.ocontexts[OCON_NODE6];
1927                 while (c) {
1928                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1929                                                 c->u.node6.mask))
1930                                 break;
1931                         c = c->next;
1932                 }
1933                 break;
1934
1935         default:
1936                 *out_sid = SECINITSID_NODE;
1937                 goto out;
1938         }
1939
1940         if (c) {
1941                 if (!c->sid[0]) {
1942                         rc = sidtab_context_to_sid(&sidtab,
1943                                                    &c->context[0],
1944                                                    &c->sid[0]);
1945                         if (rc)
1946                                 goto out;
1947                 }
1948                 *out_sid = c->sid[0];
1949         } else {
1950                 *out_sid = SECINITSID_NODE;
1951         }
1952
1953 out:
1954         read_unlock(&policy_rwlock);
1955         return rc;
1956 }
1957
1958 #define SIDS_NEL 25
1959
1960 /**
1961  * security_get_user_sids - Obtain reachable SIDs for a user.
1962  * @fromsid: starting SID
1963  * @username: username
1964  * @sids: array of reachable SIDs for user
1965  * @nel: number of elements in @sids
1966  *
1967  * Generate the set of SIDs for legal security contexts
1968  * for a given user that can be reached by @fromsid.
1969  * Set *@sids to point to a dynamically allocated
1970  * array containing the set of SIDs.  Set *@nel to the
1971  * number of elements in the array.
1972  */
1973
1974 int security_get_user_sids(u32 fromsid,
1975                            char *username,
1976                            u32 **sids,
1977                            u32 *nel)
1978 {
1979         struct context *fromcon, usercon;
1980         u32 *mysids = NULL, *mysids2, sid;
1981         u32 mynel = 0, maxnel = SIDS_NEL;
1982         struct user_datum *user;
1983         struct role_datum *role;
1984         struct ebitmap_node *rnode, *tnode;
1985         int rc = 0, i, j;
1986
1987         *sids = NULL;
1988         *nel = 0;
1989
1990         if (!ss_initialized)
1991                 goto out;
1992
1993         read_lock(&policy_rwlock);
1994
1995         context_init(&usercon);
1996
1997         fromcon = sidtab_search(&sidtab, fromsid);
1998         if (!fromcon) {
1999                 rc = -EINVAL;
2000                 goto out_unlock;
2001         }
2002
2003         user = hashtab_search(policydb.p_users.table, username);
2004         if (!user) {
2005                 rc = -EINVAL;
2006                 goto out_unlock;
2007         }
2008         usercon.user = user->value;
2009
2010         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2011         if (!mysids) {
2012                 rc = -ENOMEM;
2013                 goto out_unlock;
2014         }
2015
2016         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2017                 role = policydb.role_val_to_struct[i];
2018                 usercon.role = i+1;
2019                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2020                         usercon.type = j+1;
2021
2022                         if (mls_setup_user_range(fromcon, user, &usercon))
2023                                 continue;
2024
2025                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2026                         if (rc)
2027                                 goto out_unlock;
2028                         if (mynel < maxnel) {
2029                                 mysids[mynel++] = sid;
2030                         } else {
2031                                 maxnel += SIDS_NEL;
2032                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2033                                 if (!mysids2) {
2034                                         rc = -ENOMEM;
2035                                         goto out_unlock;
2036                                 }
2037                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2038                                 kfree(mysids);
2039                                 mysids = mysids2;
2040                                 mysids[mynel++] = sid;
2041                         }
2042                 }
2043         }
2044
2045 out_unlock:
2046         read_unlock(&policy_rwlock);
2047         if (rc || !mynel) {
2048                 kfree(mysids);
2049                 goto out;
2050         }
2051
2052         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2053         if (!mysids2) {
2054                 rc = -ENOMEM;
2055                 kfree(mysids);
2056                 goto out;
2057         }
2058         for (i = 0, j = 0; i < mynel; i++) {
2059                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2060                                           SECCLASS_PROCESS, /* kernel value */
2061                                           PROCESS__TRANSITION, AVC_STRICT,
2062                                           NULL);
2063                 if (!rc)
2064                         mysids2[j++] = mysids[i];
2065                 cond_resched();
2066         }
2067         rc = 0;
2068         kfree(mysids);
2069         *sids = mysids2;
2070         *nel = j;
2071 out:
2072         return rc;
2073 }
2074
2075 /**
2076  * security_genfs_sid - Obtain a SID for a file in a filesystem
2077  * @fstype: filesystem type
2078  * @path: path from root of mount
2079  * @sclass: file security class
2080  * @sid: SID for path
2081  *
2082  * Obtain a SID to use for a file in a filesystem that
2083  * cannot support xattr or use a fixed labeling behavior like
2084  * transition SIDs or task SIDs.
2085  */
2086 int security_genfs_sid(const char *fstype,
2087                        char *path,
2088                        u16 orig_sclass,
2089                        u32 *sid)
2090 {
2091         int len;
2092         u16 sclass;
2093         struct genfs *genfs;
2094         struct ocontext *c;
2095         int rc = 0, cmp = 0;
2096
2097         while (path[0] == '/' && path[1] == '/')
2098                 path++;
2099
2100         read_lock(&policy_rwlock);
2101
2102         sclass = unmap_class(orig_sclass);
2103
2104         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2105                 cmp = strcmp(fstype, genfs->fstype);
2106                 if (cmp <= 0)
2107                         break;
2108         }
2109
2110         if (!genfs || cmp) {
2111                 *sid = SECINITSID_UNLABELED;
2112                 rc = -ENOENT;
2113                 goto out;
2114         }
2115
2116         for (c = genfs->head; c; c = c->next) {
2117                 len = strlen(c->u.name);
2118                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2119                     (strncmp(c->u.name, path, len) == 0))
2120                         break;
2121         }
2122
2123         if (!c) {
2124                 *sid = SECINITSID_UNLABELED;
2125                 rc = -ENOENT;
2126                 goto out;
2127         }
2128
2129         if (!c->sid[0]) {
2130                 rc = sidtab_context_to_sid(&sidtab,
2131                                            &c->context[0],
2132                                            &c->sid[0]);
2133                 if (rc)
2134                         goto out;
2135         }
2136
2137         *sid = c->sid[0];
2138 out:
2139         read_unlock(&policy_rwlock);
2140         return rc;
2141 }
2142
2143 /**
2144  * security_fs_use - Determine how to handle labeling for a filesystem.
2145  * @fstype: filesystem type
2146  * @behavior: labeling behavior
2147  * @sid: SID for filesystem (superblock)
2148  */
2149 int security_fs_use(
2150         const char *fstype,
2151         unsigned int *behavior,
2152         u32 *sid)
2153 {
2154         int rc = 0;
2155         struct ocontext *c;
2156
2157         read_lock(&policy_rwlock);
2158
2159         c = policydb.ocontexts[OCON_FSUSE];
2160         while (c) {
2161                 if (strcmp(fstype, c->u.name) == 0)
2162                         break;
2163                 c = c->next;
2164         }
2165
2166         if (c) {
2167                 *behavior = c->v.behavior;
2168                 if (!c->sid[0]) {
2169                         rc = sidtab_context_to_sid(&sidtab,
2170                                                    &c->context[0],
2171                                                    &c->sid[0]);
2172                         if (rc)
2173                                 goto out;
2174                 }
2175                 *sid = c->sid[0];
2176         } else {
2177                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2178                 if (rc) {
2179                         *behavior = SECURITY_FS_USE_NONE;
2180                         rc = 0;
2181                 } else {
2182                         *behavior = SECURITY_FS_USE_GENFS;
2183                 }
2184         }
2185
2186 out:
2187         read_unlock(&policy_rwlock);
2188         return rc;
2189 }
2190
2191 int security_get_bools(int *len, char ***names, int **values)
2192 {
2193         int i, rc = -ENOMEM;
2194
2195         read_lock(&policy_rwlock);
2196         *names = NULL;
2197         *values = NULL;
2198
2199         *len = policydb.p_bools.nprim;
2200         if (!*len) {
2201                 rc = 0;
2202                 goto out;
2203         }
2204
2205        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2206         if (!*names)
2207                 goto err;
2208
2209        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2210         if (!*values)
2211                 goto err;
2212
2213         for (i = 0; i < *len; i++) {
2214                 size_t name_len;
2215                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2216                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2217                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2218                 if (!(*names)[i])
2219                         goto err;
2220                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2221                 (*names)[i][name_len - 1] = 0;
2222         }
2223         rc = 0;
2224 out:
2225         read_unlock(&policy_rwlock);
2226         return rc;
2227 err:
2228         if (*names) {
2229                 for (i = 0; i < *len; i++)
2230                         kfree((*names)[i]);
2231         }
2232         kfree(*values);
2233         goto out;
2234 }
2235
2236
2237 int security_set_bools(int len, int *values)
2238 {
2239         int i, rc = 0;
2240         int lenp, seqno = 0;
2241         struct cond_node *cur;
2242
2243         write_lock_irq(&policy_rwlock);
2244
2245         lenp = policydb.p_bools.nprim;
2246         if (len != lenp) {
2247                 rc = -EFAULT;
2248                 goto out;
2249         }
2250
2251         for (i = 0; i < len; i++) {
2252                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2253                         audit_log(current->audit_context, GFP_ATOMIC,
2254                                 AUDIT_MAC_CONFIG_CHANGE,
2255                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2256                                 policydb.p_bool_val_to_name[i],
2257                                 !!values[i],
2258                                 policydb.bool_val_to_struct[i]->state,
2259                                 audit_get_loginuid(current),
2260                                 audit_get_sessionid(current));
2261                 }
2262                 if (values[i])
2263                         policydb.bool_val_to_struct[i]->state = 1;
2264                 else
2265                         policydb.bool_val_to_struct[i]->state = 0;
2266         }
2267
2268         for (cur = policydb.cond_list; cur; cur = cur->next) {
2269                 rc = evaluate_cond_node(&policydb, cur);
2270                 if (rc)
2271                         goto out;
2272         }
2273
2274         seqno = ++latest_granting;
2275
2276 out:
2277         write_unlock_irq(&policy_rwlock);
2278         if (!rc) {
2279                 avc_ss_reset(seqno);
2280                 selnl_notify_policyload(seqno);
2281                 selinux_xfrm_notify_policyload();
2282         }
2283         return rc;
2284 }
2285
2286 int security_get_bool_value(int bool)
2287 {
2288         int rc = 0;
2289         int len;
2290
2291         read_lock(&policy_rwlock);
2292
2293         len = policydb.p_bools.nprim;
2294         if (bool >= len) {
2295                 rc = -EFAULT;
2296                 goto out;
2297         }
2298
2299         rc = policydb.bool_val_to_struct[bool]->state;
2300 out:
2301         read_unlock(&policy_rwlock);
2302         return rc;
2303 }
2304
2305 static int security_preserve_bools(struct policydb *p)
2306 {
2307         int rc, nbools = 0, *bvalues = NULL, i;
2308         char **bnames = NULL;
2309         struct cond_bool_datum *booldatum;
2310         struct cond_node *cur;
2311
2312         rc = security_get_bools(&nbools, &bnames, &bvalues);
2313         if (rc)
2314                 goto out;
2315         for (i = 0; i < nbools; i++) {
2316                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2317                 if (booldatum)
2318                         booldatum->state = bvalues[i];
2319         }
2320         for (cur = p->cond_list; cur; cur = cur->next) {
2321                 rc = evaluate_cond_node(p, cur);
2322                 if (rc)
2323                         goto out;
2324         }
2325
2326 out:
2327         if (bnames) {
2328                 for (i = 0; i < nbools; i++)
2329                         kfree(bnames[i]);
2330         }
2331         kfree(bnames);
2332         kfree(bvalues);
2333         return rc;
2334 }
2335
2336 /*
2337  * security_sid_mls_copy() - computes a new sid based on the given
2338  * sid and the mls portion of mls_sid.
2339  */
2340 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2341 {
2342         struct context *context1;
2343         struct context *context2;
2344         struct context newcon;
2345         char *s;
2346         u32 len;
2347         int rc = 0;
2348
2349         if (!ss_initialized || !selinux_mls_enabled) {
2350                 *new_sid = sid;
2351                 goto out;
2352         }
2353
2354         context_init(&newcon);
2355
2356         read_lock(&policy_rwlock);
2357         context1 = sidtab_search(&sidtab, sid);
2358         if (!context1) {
2359                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2360                         __func__, sid);
2361                 rc = -EINVAL;
2362                 goto out_unlock;
2363         }
2364
2365         context2 = sidtab_search(&sidtab, mls_sid);
2366         if (!context2) {
2367                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2368                         __func__, mls_sid);
2369                 rc = -EINVAL;
2370                 goto out_unlock;
2371         }
2372
2373         newcon.user = context1->user;
2374         newcon.role = context1->role;
2375         newcon.type = context1->type;
2376         rc = mls_context_cpy(&newcon, context2);
2377         if (rc)
2378                 goto out_unlock;
2379
2380         /* Check the validity of the new context. */
2381         if (!policydb_context_isvalid(&policydb, &newcon)) {
2382                 rc = convert_context_handle_invalid_context(&newcon);
2383                 if (rc)
2384                         goto bad;
2385         }
2386
2387         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2388         goto out_unlock;
2389
2390 bad:
2391         if (!context_struct_to_string(&newcon, &s, &len)) {
2392                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2393                           "security_sid_mls_copy: invalid context %s", s);
2394                 kfree(s);
2395         }
2396
2397 out_unlock:
2398         read_unlock(&policy_rwlock);
2399         context_destroy(&newcon);
2400 out:
2401         return rc;
2402 }
2403
2404 /**
2405  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2406  * @nlbl_sid: NetLabel SID
2407  * @nlbl_type: NetLabel labeling protocol type
2408  * @xfrm_sid: XFRM SID
2409  *
2410  * Description:
2411  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2412  * resolved into a single SID it is returned via @peer_sid and the function
2413  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2414  * returns a negative value.  A table summarizing the behavior is below:
2415  *
2416  *                                 | function return |      @sid
2417  *   ------------------------------+-----------------+-----------------
2418  *   no peer labels                |        0        |    SECSID_NULL
2419  *   single peer label             |        0        |    <peer_label>
2420  *   multiple, consistent labels   |        0        |    <peer_label>
2421  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2422  *
2423  */
2424 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2425                                  u32 xfrm_sid,
2426                                  u32 *peer_sid)
2427 {
2428         int rc;
2429         struct context *nlbl_ctx;
2430         struct context *xfrm_ctx;
2431
2432         /* handle the common (which also happens to be the set of easy) cases
2433          * right away, these two if statements catch everything involving a
2434          * single or absent peer SID/label */
2435         if (xfrm_sid == SECSID_NULL) {
2436                 *peer_sid = nlbl_sid;
2437                 return 0;
2438         }
2439         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2440          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2441          * is present */
2442         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2443                 *peer_sid = xfrm_sid;
2444                 return 0;
2445         }
2446
2447         /* we don't need to check ss_initialized here since the only way both
2448          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2449          * security server was initialized and ss_initialized was true */
2450         if (!selinux_mls_enabled) {
2451                 *peer_sid = SECSID_NULL;
2452                 return 0;
2453         }
2454
2455         read_lock(&policy_rwlock);
2456
2457         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2458         if (!nlbl_ctx) {
2459                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2460                        __func__, nlbl_sid);
2461                 rc = -EINVAL;
2462                 goto out_slowpath;
2463         }
2464         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2465         if (!xfrm_ctx) {
2466                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2467                        __func__, xfrm_sid);
2468                 rc = -EINVAL;
2469                 goto out_slowpath;
2470         }
2471         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2472
2473 out_slowpath:
2474         read_unlock(&policy_rwlock);
2475         if (rc == 0)
2476                 /* at present NetLabel SIDs/labels really only carry MLS
2477                  * information so if the MLS portion of the NetLabel SID
2478                  * matches the MLS portion of the labeled XFRM SID/label
2479                  * then pass along the XFRM SID as it is the most
2480                  * expressive */
2481                 *peer_sid = xfrm_sid;
2482         else
2483                 *peer_sid = SECSID_NULL;
2484         return rc;
2485 }
2486
2487 static int get_classes_callback(void *k, void *d, void *args)
2488 {
2489         struct class_datum *datum = d;
2490         char *name = k, **classes = args;
2491         int value = datum->value - 1;
2492
2493         classes[value] = kstrdup(name, GFP_ATOMIC);
2494         if (!classes[value])
2495                 return -ENOMEM;
2496
2497         return 0;
2498 }
2499
2500 int security_get_classes(char ***classes, int *nclasses)
2501 {
2502         int rc = -ENOMEM;
2503
2504         read_lock(&policy_rwlock);
2505
2506         *nclasses = policydb.p_classes.nprim;
2507         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2508         if (!*classes)
2509                 goto out;
2510
2511         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2512                         *classes);
2513         if (rc < 0) {
2514                 int i;
2515                 for (i = 0; i < *nclasses; i++)
2516                         kfree((*classes)[i]);
2517                 kfree(*classes);
2518         }
2519
2520 out:
2521         read_unlock(&policy_rwlock);
2522         return rc;
2523 }
2524
2525 static int get_permissions_callback(void *k, void *d, void *args)
2526 {
2527         struct perm_datum *datum = d;
2528         char *name = k, **perms = args;
2529         int value = datum->value - 1;
2530
2531         perms[value] = kstrdup(name, GFP_ATOMIC);
2532         if (!perms[value])
2533                 return -ENOMEM;
2534
2535         return 0;
2536 }
2537
2538 int security_get_permissions(char *class, char ***perms, int *nperms)
2539 {
2540         int rc = -ENOMEM, i;
2541         struct class_datum *match;
2542
2543         read_lock(&policy_rwlock);
2544
2545         match = hashtab_search(policydb.p_classes.table, class);
2546         if (!match) {
2547                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2548                         __func__, class);
2549                 rc = -EINVAL;
2550                 goto out;
2551         }
2552
2553         *nperms = match->permissions.nprim;
2554         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2555         if (!*perms)
2556                 goto out;
2557
2558         if (match->comdatum) {
2559                 rc = hashtab_map(match->comdatum->permissions.table,
2560                                 get_permissions_callback, *perms);
2561                 if (rc < 0)
2562                         goto err;
2563         }
2564
2565         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2566                         *perms);
2567         if (rc < 0)
2568                 goto err;
2569
2570 out:
2571         read_unlock(&policy_rwlock);
2572         return rc;
2573
2574 err:
2575         read_unlock(&policy_rwlock);
2576         for (i = 0; i < *nperms; i++)
2577                 kfree((*perms)[i]);
2578         kfree(*perms);
2579         return rc;
2580 }
2581
2582 int security_get_reject_unknown(void)
2583 {
2584         return policydb.reject_unknown;
2585 }
2586
2587 int security_get_allow_unknown(void)
2588 {
2589         return policydb.allow_unknown;
2590 }
2591
2592 /**
2593  * security_policycap_supported - Check for a specific policy capability
2594  * @req_cap: capability
2595  *
2596  * Description:
2597  * This function queries the currently loaded policy to see if it supports the
2598  * capability specified by @req_cap.  Returns true (1) if the capability is
2599  * supported, false (0) if it isn't supported.
2600  *
2601  */
2602 int security_policycap_supported(unsigned int req_cap)
2603 {
2604         int rc;
2605
2606         read_lock(&policy_rwlock);
2607         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2608         read_unlock(&policy_rwlock);
2609
2610         return rc;
2611 }
2612
2613 struct selinux_audit_rule {
2614         u32 au_seqno;
2615         struct context au_ctxt;
2616 };
2617
2618 void selinux_audit_rule_free(void *vrule)
2619 {
2620         struct selinux_audit_rule *rule = vrule;
2621
2622         if (rule) {
2623                 context_destroy(&rule->au_ctxt);
2624                 kfree(rule);
2625         }
2626 }
2627
2628 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2629 {
2630         struct selinux_audit_rule *tmprule;
2631         struct role_datum *roledatum;
2632         struct type_datum *typedatum;
2633         struct user_datum *userdatum;
2634         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2635         int rc = 0;
2636
2637         *rule = NULL;
2638
2639         if (!ss_initialized)
2640                 return -EOPNOTSUPP;
2641
2642         switch (field) {
2643         case AUDIT_SUBJ_USER:
2644         case AUDIT_SUBJ_ROLE:
2645         case AUDIT_SUBJ_TYPE:
2646         case AUDIT_OBJ_USER:
2647         case AUDIT_OBJ_ROLE:
2648         case AUDIT_OBJ_TYPE:
2649                 /* only 'equals' and 'not equals' fit user, role, and type */
2650                 if (op != Audit_equal && op != Audit_not_equal)
2651                         return -EINVAL;
2652                 break;
2653         case AUDIT_SUBJ_SEN:
2654         case AUDIT_SUBJ_CLR:
2655         case AUDIT_OBJ_LEV_LOW:
2656         case AUDIT_OBJ_LEV_HIGH:
2657                 /* we do not allow a range, indicated by the presense of '-' */
2658                 if (strchr(rulestr, '-'))
2659                         return -EINVAL;
2660                 break;
2661         default:
2662                 /* only the above fields are valid */
2663                 return -EINVAL;
2664         }
2665
2666         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2667         if (!tmprule)
2668                 return -ENOMEM;
2669
2670         context_init(&tmprule->au_ctxt);
2671
2672         read_lock(&policy_rwlock);
2673
2674         tmprule->au_seqno = latest_granting;
2675
2676         switch (field) {
2677         case AUDIT_SUBJ_USER:
2678         case AUDIT_OBJ_USER:
2679                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2680                 if (!userdatum)
2681                         rc = -EINVAL;
2682                 else
2683                         tmprule->au_ctxt.user = userdatum->value;
2684                 break;
2685         case AUDIT_SUBJ_ROLE:
2686         case AUDIT_OBJ_ROLE:
2687                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2688                 if (!roledatum)
2689                         rc = -EINVAL;
2690                 else
2691                         tmprule->au_ctxt.role = roledatum->value;
2692                 break;
2693         case AUDIT_SUBJ_TYPE:
2694         case AUDIT_OBJ_TYPE:
2695                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2696                 if (!typedatum)
2697                         rc = -EINVAL;
2698                 else
2699                         tmprule->au_ctxt.type = typedatum->value;
2700                 break;
2701         case AUDIT_SUBJ_SEN:
2702         case AUDIT_SUBJ_CLR:
2703         case AUDIT_OBJ_LEV_LOW:
2704         case AUDIT_OBJ_LEV_HIGH:
2705                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2706                 break;
2707         }
2708
2709         read_unlock(&policy_rwlock);
2710
2711         if (rc) {
2712                 selinux_audit_rule_free(tmprule);
2713                 tmprule = NULL;
2714         }
2715
2716         *rule = tmprule;
2717
2718         return rc;
2719 }
2720
2721 /* Check to see if the rule contains any selinux fields */
2722 int selinux_audit_rule_known(struct audit_krule *rule)
2723 {
2724         int i;
2725
2726         for (i = 0; i < rule->field_count; i++) {
2727                 struct audit_field *f = &rule->fields[i];
2728                 switch (f->type) {
2729                 case AUDIT_SUBJ_USER:
2730                 case AUDIT_SUBJ_ROLE:
2731                 case AUDIT_SUBJ_TYPE:
2732                 case AUDIT_SUBJ_SEN:
2733                 case AUDIT_SUBJ_CLR:
2734                 case AUDIT_OBJ_USER:
2735                 case AUDIT_OBJ_ROLE:
2736                 case AUDIT_OBJ_TYPE:
2737                 case AUDIT_OBJ_LEV_LOW:
2738                 case AUDIT_OBJ_LEV_HIGH:
2739                         return 1;
2740                 }
2741         }
2742
2743         return 0;
2744 }
2745
2746 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2747                              struct audit_context *actx)
2748 {
2749         struct context *ctxt;
2750         struct mls_level *level;
2751         struct selinux_audit_rule *rule = vrule;
2752         int match = 0;
2753
2754         if (!rule) {
2755                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2756                           "selinux_audit_rule_match: missing rule\n");
2757                 return -ENOENT;
2758         }
2759
2760         read_lock(&policy_rwlock);
2761
2762         if (rule->au_seqno < latest_granting) {
2763                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2764                           "selinux_audit_rule_match: stale rule\n");
2765                 match = -ESTALE;
2766                 goto out;
2767         }
2768
2769         ctxt = sidtab_search(&sidtab, sid);
2770         if (!ctxt) {
2771                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2772                           "selinux_audit_rule_match: unrecognized SID %d\n",
2773                           sid);
2774                 match = -ENOENT;
2775                 goto out;
2776         }
2777
2778         /* a field/op pair that is not caught here will simply fall through
2779            without a match */
2780         switch (field) {
2781         case AUDIT_SUBJ_USER:
2782         case AUDIT_OBJ_USER:
2783                 switch (op) {
2784                 case Audit_equal:
2785                         match = (ctxt->user == rule->au_ctxt.user);
2786                         break;
2787                 case Audit_not_equal:
2788                         match = (ctxt->user != rule->au_ctxt.user);
2789                         break;
2790                 }
2791                 break;
2792         case AUDIT_SUBJ_ROLE:
2793         case AUDIT_OBJ_ROLE:
2794                 switch (op) {
2795                 case Audit_equal:
2796                         match = (ctxt->role == rule->au_ctxt.role);
2797                         break;
2798                 case Audit_not_equal:
2799                         match = (ctxt->role != rule->au_ctxt.role);
2800                         break;
2801                 }
2802                 break;
2803         case AUDIT_SUBJ_TYPE:
2804         case AUDIT_OBJ_TYPE:
2805                 switch (op) {
2806                 case Audit_equal:
2807                         match = (ctxt->type == rule->au_ctxt.type);
2808                         break;
2809                 case Audit_not_equal:
2810                         match = (ctxt->type != rule->au_ctxt.type);
2811                         break;
2812                 }
2813                 break;
2814         case AUDIT_SUBJ_SEN:
2815         case AUDIT_SUBJ_CLR:
2816         case AUDIT_OBJ_LEV_LOW:
2817         case AUDIT_OBJ_LEV_HIGH:
2818                 level = ((field == AUDIT_SUBJ_SEN ||
2819                           field == AUDIT_OBJ_LEV_LOW) ?
2820                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2821                 switch (op) {
2822                 case Audit_equal:
2823                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2824                                              level);
2825                         break;
2826                 case Audit_not_equal:
2827                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2828                                               level);
2829                         break;
2830                 case Audit_lt:
2831                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2832                                                level) &&
2833                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2834                                                level));
2835                         break;
2836                 case Audit_le:
2837                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2838                                               level);
2839                         break;
2840                 case Audit_gt:
2841                         match = (mls_level_dom(level,
2842                                               &rule->au_ctxt.range.level[0]) &&
2843                                  !mls_level_eq(level,
2844                                                &rule->au_ctxt.range.level[0]));
2845                         break;
2846                 case Audit_ge:
2847                         match = mls_level_dom(level,
2848                                               &rule->au_ctxt.range.level[0]);
2849                         break;
2850                 }
2851         }
2852
2853 out:
2854         read_unlock(&policy_rwlock);
2855         return match;
2856 }
2857
2858 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2859
2860 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2861                                u16 class, u32 perms, u32 *retained)
2862 {
2863         int err = 0;
2864
2865         if (event == AVC_CALLBACK_RESET && aurule_callback)
2866                 err = aurule_callback();
2867         return err;
2868 }
2869
2870 static int __init aurule_init(void)
2871 {
2872         int err;
2873
2874         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2875                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2876         if (err)
2877                 panic("avc_add_callback() failed, error %d\n", err);
2878
2879         return err;
2880 }
2881 __initcall(aurule_init);
2882
2883 #ifdef CONFIG_NETLABEL
2884 /**
2885  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2886  * @secattr: the NetLabel packet security attributes
2887  * @sid: the SELinux SID
2888  *
2889  * Description:
2890  * Attempt to cache the context in @ctx, which was derived from the packet in
2891  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2892  * already been initialized.
2893  *
2894  */
2895 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2896                                       u32 sid)
2897 {
2898         u32 *sid_cache;
2899
2900         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2901         if (sid_cache == NULL)
2902                 return;
2903         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2904         if (secattr->cache == NULL) {
2905                 kfree(sid_cache);
2906                 return;
2907         }
2908
2909         *sid_cache = sid;
2910         secattr->cache->free = kfree;
2911         secattr->cache->data = sid_cache;
2912         secattr->flags |= NETLBL_SECATTR_CACHE;
2913 }
2914
2915 /**
2916  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2917  * @secattr: the NetLabel packet security attributes
2918  * @sid: the SELinux SID
2919  *
2920  * Description:
2921  * Convert the given NetLabel security attributes in @secattr into a
2922  * SELinux SID.  If the @secattr field does not contain a full SELinux
2923  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2924  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2925  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2926  * conversion for future lookups.  Returns zero on success, negative values on
2927  * failure.
2928  *
2929  */
2930 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2931                                    u32 *sid)
2932 {
2933         int rc = -EIDRM;
2934         struct context *ctx;
2935         struct context ctx_new;
2936
2937         if (!ss_initialized) {
2938                 *sid = SECSID_NULL;
2939                 return 0;
2940         }
2941
2942         read_lock(&policy_rwlock);
2943
2944         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2945                 *sid = *(u32 *)secattr->cache->data;
2946                 rc = 0;
2947         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2948                 *sid = secattr->attr.secid;
2949                 rc = 0;
2950         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2951                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2952                 if (ctx == NULL)
2953                         goto netlbl_secattr_to_sid_return;
2954
2955                 context_init(&ctx_new);
2956                 ctx_new.user = ctx->user;
2957                 ctx_new.role = ctx->role;
2958                 ctx_new.type = ctx->type;
2959                 mls_import_netlbl_lvl(&ctx_new, secattr);
2960                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2961                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2962                                                   secattr->attr.mls.cat) != 0)
2963                                 goto netlbl_secattr_to_sid_return;
2964                         memcpy(&ctx_new.range.level[1].cat,
2965                                &ctx_new.range.level[0].cat,
2966                                sizeof(ctx_new.range.level[0].cat));
2967                 }
2968                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2969                         goto netlbl_secattr_to_sid_return_cleanup;
2970
2971                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2972                 if (rc != 0)
2973                         goto netlbl_secattr_to_sid_return_cleanup;
2974
2975                 security_netlbl_cache_add(secattr, *sid);
2976
2977                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2978         } else {
2979                 *sid = SECSID_NULL;
2980                 rc = 0;
2981         }
2982
2983 netlbl_secattr_to_sid_return:
2984         read_unlock(&policy_rwlock);
2985         return rc;
2986 netlbl_secattr_to_sid_return_cleanup:
2987         ebitmap_destroy(&ctx_new.range.level[0].cat);
2988         goto netlbl_secattr_to_sid_return;
2989 }
2990
2991 /**
2992  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2993  * @sid: the SELinux SID
2994  * @secattr: the NetLabel packet security attributes
2995  *
2996  * Description:
2997  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2998  * Returns zero on success, negative values on failure.
2999  *
3000  */
3001 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3002 {
3003         int rc;
3004         struct context *ctx;
3005
3006         if (!ss_initialized)
3007                 return 0;
3008
3009         read_lock(&policy_rwlock);
3010         ctx = sidtab_search(&sidtab, sid);
3011         if (ctx == NULL) {
3012                 rc = -ENOENT;
3013                 goto netlbl_sid_to_secattr_failure;
3014         }
3015         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
3016                                   GFP_ATOMIC);
3017         if (secattr->domain == NULL) {
3018                 rc = -ENOMEM;
3019                 goto netlbl_sid_to_secattr_failure;
3020         }
3021         secattr->attr.secid = sid;
3022         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3023         mls_export_netlbl_lvl(ctx, secattr);
3024         rc = mls_export_netlbl_cat(ctx, secattr);
3025         if (rc != 0)
3026                 goto netlbl_sid_to_secattr_failure;
3027         read_unlock(&policy_rwlock);
3028
3029         return 0;
3030
3031 netlbl_sid_to_secattr_failure:
3032         read_unlock(&policy_rwlock);
3033         return rc;
3034 }
3035 #endif /* CONFIG_NETLABEL */