selinux: remove dead code in type_attribute_bounds_av()
[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         return sidtab_insert(s, sid, context);
1510 }
1511
1512 static inline int convert_context_handle_invalid_context(struct context *context)
1513 {
1514         int rc = 0;
1515
1516         if (selinux_enforcing) {
1517                 rc = -EINVAL;
1518         } else {
1519                 char *s;
1520                 u32 len;
1521
1522                 if (!context_struct_to_string(context, &s, &len)) {
1523                         printk(KERN_WARNING
1524                        "SELinux:  Context %s would be invalid if enforcing\n",
1525                                s);
1526                         kfree(s);
1527                 }
1528         }
1529         return rc;
1530 }
1531
1532 struct convert_context_args {
1533         struct policydb *oldp;
1534         struct policydb *newp;
1535 };
1536
1537 /*
1538  * Convert the values in the security context
1539  * structure `c' from the values specified
1540  * in the policy `p->oldp' to the values specified
1541  * in the policy `p->newp'.  Verify that the
1542  * context is valid under the new policy.
1543  */
1544 static int convert_context(u32 key,
1545                            struct context *c,
1546                            void *p)
1547 {
1548         struct convert_context_args *args;
1549         struct context oldc;
1550         struct role_datum *role;
1551         struct type_datum *typdatum;
1552         struct user_datum *usrdatum;
1553         char *s;
1554         u32 len;
1555         int rc;
1556
1557         args = p;
1558
1559         if (c->str) {
1560                 struct context ctx;
1561                 s = kstrdup(c->str, GFP_KERNEL);
1562                 if (!s) {
1563                         rc = -ENOMEM;
1564                         goto out;
1565                 }
1566                 rc = string_to_context_struct(args->newp, NULL, s,
1567                                               c->len, &ctx, SECSID_NULL);
1568                 kfree(s);
1569                 if (!rc) {
1570                         printk(KERN_INFO
1571                        "SELinux:  Context %s became valid (mapped).\n",
1572                                c->str);
1573                         /* Replace string with mapped representation. */
1574                         kfree(c->str);
1575                         memcpy(c, &ctx, sizeof(*c));
1576                         goto out;
1577                 } else if (rc == -EINVAL) {
1578                         /* Retain string representation for later mapping. */
1579                         rc = 0;
1580                         goto out;
1581                 } else {
1582                         /* Other error condition, e.g. ENOMEM. */
1583                         printk(KERN_ERR
1584                        "SELinux:   Unable to map context %s, rc = %d.\n",
1585                                c->str, -rc);
1586                         goto out;
1587                 }
1588         }
1589
1590         rc = context_cpy(&oldc, c);
1591         if (rc)
1592                 goto out;
1593
1594         rc = -EINVAL;
1595
1596         /* Convert the user. */
1597         usrdatum = hashtab_search(args->newp->p_users.table,
1598                                   args->oldp->p_user_val_to_name[c->user - 1]);
1599         if (!usrdatum)
1600                 goto bad;
1601         c->user = usrdatum->value;
1602
1603         /* Convert the role. */
1604         role = hashtab_search(args->newp->p_roles.table,
1605                               args->oldp->p_role_val_to_name[c->role - 1]);
1606         if (!role)
1607                 goto bad;
1608         c->role = role->value;
1609
1610         /* Convert the type. */
1611         typdatum = hashtab_search(args->newp->p_types.table,
1612                                   args->oldp->p_type_val_to_name[c->type - 1]);
1613         if (!typdatum)
1614                 goto bad;
1615         c->type = typdatum->value;
1616
1617         rc = mls_convert_context(args->oldp, args->newp, c);
1618         if (rc)
1619                 goto bad;
1620
1621         /* Check the validity of the new context. */
1622         if (!policydb_context_isvalid(args->newp, c)) {
1623                 rc = convert_context_handle_invalid_context(&oldc);
1624                 if (rc)
1625                         goto bad;
1626         }
1627
1628         context_destroy(&oldc);
1629         rc = 0;
1630 out:
1631         return rc;
1632 bad:
1633         /* Map old representation to string and save it. */
1634         if (context_struct_to_string(&oldc, &s, &len))
1635                 return -ENOMEM;
1636         context_destroy(&oldc);
1637         context_destroy(c);
1638         c->str = s;
1639         c->len = len;
1640         printk(KERN_INFO
1641                "SELinux:  Context %s became invalid (unmapped).\n",
1642                c->str);
1643         rc = 0;
1644         goto out;
1645 }
1646
1647 static void security_load_policycaps(void)
1648 {
1649         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1650                                                   POLICYDB_CAPABILITY_NETPEER);
1651         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1652                                                   POLICYDB_CAPABILITY_OPENPERM);
1653 }
1654
1655 extern void selinux_complete_init(void);
1656 static int security_preserve_bools(struct policydb *p);
1657
1658 /**
1659  * security_load_policy - Load a security policy configuration.
1660  * @data: binary policy data
1661  * @len: length of data in bytes
1662  *
1663  * Load a new set of security policy configuration data,
1664  * validate it and convert the SID table as necessary.
1665  * This function will flush the access vector cache after
1666  * loading the new policy.
1667  */
1668 int security_load_policy(void *data, size_t len)
1669 {
1670         struct policydb oldpolicydb, newpolicydb;
1671         struct sidtab oldsidtab, newsidtab;
1672         struct selinux_mapping *oldmap, *map = NULL;
1673         struct convert_context_args args;
1674         u32 seqno;
1675         u16 map_size;
1676         int rc = 0;
1677         struct policy_file file = { data, len }, *fp = &file;
1678
1679         if (!ss_initialized) {
1680                 avtab_cache_init();
1681                 if (policydb_read(&policydb, fp)) {
1682                         avtab_cache_destroy();
1683                         return -EINVAL;
1684                 }
1685                 if (selinux_set_mapping(&policydb, secclass_map,
1686                                         &current_mapping,
1687                                         &current_mapping_size)) {
1688                         policydb_destroy(&policydb);
1689                         avtab_cache_destroy();
1690                         return -EINVAL;
1691                 }
1692                 if (policydb_load_isids(&policydb, &sidtab)) {
1693                         policydb_destroy(&policydb);
1694                         avtab_cache_destroy();
1695                         return -EINVAL;
1696                 }
1697                 security_load_policycaps();
1698                 ss_initialized = 1;
1699                 seqno = ++latest_granting;
1700                 selinux_complete_init();
1701                 avc_ss_reset(seqno);
1702                 selnl_notify_policyload(seqno);
1703                 selinux_netlbl_cache_invalidate();
1704                 selinux_xfrm_notify_policyload();
1705                 return 0;
1706         }
1707
1708 #if 0
1709         sidtab_hash_eval(&sidtab, "sids");
1710 #endif
1711
1712         if (policydb_read(&newpolicydb, fp))
1713                 return -EINVAL;
1714
1715         if (sidtab_init(&newsidtab)) {
1716                 policydb_destroy(&newpolicydb);
1717                 return -ENOMEM;
1718         }
1719
1720         if (selinux_set_mapping(&newpolicydb, secclass_map,
1721                                 &map, &map_size))
1722                 goto err;
1723
1724         rc = security_preserve_bools(&newpolicydb);
1725         if (rc) {
1726                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1727                 goto err;
1728         }
1729
1730         /* Clone the SID table. */
1731         sidtab_shutdown(&sidtab);
1732         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1733                 rc = -ENOMEM;
1734                 goto err;
1735         }
1736
1737         /*
1738          * Convert the internal representations of contexts
1739          * in the new SID table.
1740          */
1741         args.oldp = &policydb;
1742         args.newp = &newpolicydb;
1743         rc = sidtab_map(&newsidtab, convert_context, &args);
1744         if (rc)
1745                 goto err;
1746
1747         /* Save the old policydb and SID table to free later. */
1748         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1749         sidtab_set(&oldsidtab, &sidtab);
1750
1751         /* Install the new policydb and SID table. */
1752         write_lock_irq(&policy_rwlock);
1753         memcpy(&policydb, &newpolicydb, sizeof policydb);
1754         sidtab_set(&sidtab, &newsidtab);
1755         security_load_policycaps();
1756         oldmap = current_mapping;
1757         current_mapping = map;
1758         current_mapping_size = map_size;
1759         seqno = ++latest_granting;
1760         write_unlock_irq(&policy_rwlock);
1761
1762         /* Free the old policydb and SID table. */
1763         policydb_destroy(&oldpolicydb);
1764         sidtab_destroy(&oldsidtab);
1765         kfree(oldmap);
1766
1767         avc_ss_reset(seqno);
1768         selnl_notify_policyload(seqno);
1769         selinux_netlbl_cache_invalidate();
1770         selinux_xfrm_notify_policyload();
1771
1772         return 0;
1773
1774 err:
1775         kfree(map);
1776         sidtab_destroy(&newsidtab);
1777         policydb_destroy(&newpolicydb);
1778         return rc;
1779
1780 }
1781
1782 /**
1783  * security_port_sid - Obtain the SID for a port.
1784  * @protocol: protocol number
1785  * @port: port number
1786  * @out_sid: security identifier
1787  */
1788 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1789 {
1790         struct ocontext *c;
1791         int rc = 0;
1792
1793         read_lock(&policy_rwlock);
1794
1795         c = policydb.ocontexts[OCON_PORT];
1796         while (c) {
1797                 if (c->u.port.protocol == protocol &&
1798                     c->u.port.low_port <= port &&
1799                     c->u.port.high_port >= port)
1800                         break;
1801                 c = c->next;
1802         }
1803
1804         if (c) {
1805                 if (!c->sid[0]) {
1806                         rc = sidtab_context_to_sid(&sidtab,
1807                                                    &c->context[0],
1808                                                    &c->sid[0]);
1809                         if (rc)
1810                                 goto out;
1811                 }
1812                 *out_sid = c->sid[0];
1813         } else {
1814                 *out_sid = SECINITSID_PORT;
1815         }
1816
1817 out:
1818         read_unlock(&policy_rwlock);
1819         return rc;
1820 }
1821
1822 /**
1823  * security_netif_sid - Obtain the SID for a network interface.
1824  * @name: interface name
1825  * @if_sid: interface SID
1826  */
1827 int security_netif_sid(char *name, u32 *if_sid)
1828 {
1829         int rc = 0;
1830         struct ocontext *c;
1831
1832         read_lock(&policy_rwlock);
1833
1834         c = policydb.ocontexts[OCON_NETIF];
1835         while (c) {
1836                 if (strcmp(name, c->u.name) == 0)
1837                         break;
1838                 c = c->next;
1839         }
1840
1841         if (c) {
1842                 if (!c->sid[0] || !c->sid[1]) {
1843                         rc = sidtab_context_to_sid(&sidtab,
1844                                                   &c->context[0],
1845                                                   &c->sid[0]);
1846                         if (rc)
1847                                 goto out;
1848                         rc = sidtab_context_to_sid(&sidtab,
1849                                                    &c->context[1],
1850                                                    &c->sid[1]);
1851                         if (rc)
1852                                 goto out;
1853                 }
1854                 *if_sid = c->sid[0];
1855         } else
1856                 *if_sid = SECINITSID_NETIF;
1857
1858 out:
1859         read_unlock(&policy_rwlock);
1860         return rc;
1861 }
1862
1863 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1864 {
1865         int i, fail = 0;
1866
1867         for (i = 0; i < 4; i++)
1868                 if (addr[i] != (input[i] & mask[i])) {
1869                         fail = 1;
1870                         break;
1871                 }
1872
1873         return !fail;
1874 }
1875
1876 /**
1877  * security_node_sid - Obtain the SID for a node (host).
1878  * @domain: communication domain aka address family
1879  * @addrp: address
1880  * @addrlen: address length in bytes
1881  * @out_sid: security identifier
1882  */
1883 int security_node_sid(u16 domain,
1884                       void *addrp,
1885                       u32 addrlen,
1886                       u32 *out_sid)
1887 {
1888         int rc = 0;
1889         struct ocontext *c;
1890
1891         read_lock(&policy_rwlock);
1892
1893         switch (domain) {
1894         case AF_INET: {
1895                 u32 addr;
1896
1897                 if (addrlen != sizeof(u32)) {
1898                         rc = -EINVAL;
1899                         goto out;
1900                 }
1901
1902                 addr = *((u32 *)addrp);
1903
1904                 c = policydb.ocontexts[OCON_NODE];
1905                 while (c) {
1906                         if (c->u.node.addr == (addr & c->u.node.mask))
1907                                 break;
1908                         c = c->next;
1909                 }
1910                 break;
1911         }
1912
1913         case AF_INET6:
1914                 if (addrlen != sizeof(u64) * 2) {
1915                         rc = -EINVAL;
1916                         goto out;
1917                 }
1918                 c = policydb.ocontexts[OCON_NODE6];
1919                 while (c) {
1920                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1921                                                 c->u.node6.mask))
1922                                 break;
1923                         c = c->next;
1924                 }
1925                 break;
1926
1927         default:
1928                 *out_sid = SECINITSID_NODE;
1929                 goto out;
1930         }
1931
1932         if (c) {
1933                 if (!c->sid[0]) {
1934                         rc = sidtab_context_to_sid(&sidtab,
1935                                                    &c->context[0],
1936                                                    &c->sid[0]);
1937                         if (rc)
1938                                 goto out;
1939                 }
1940                 *out_sid = c->sid[0];
1941         } else {
1942                 *out_sid = SECINITSID_NODE;
1943         }
1944
1945 out:
1946         read_unlock(&policy_rwlock);
1947         return rc;
1948 }
1949
1950 #define SIDS_NEL 25
1951
1952 /**
1953  * security_get_user_sids - Obtain reachable SIDs for a user.
1954  * @fromsid: starting SID
1955  * @username: username
1956  * @sids: array of reachable SIDs for user
1957  * @nel: number of elements in @sids
1958  *
1959  * Generate the set of SIDs for legal security contexts
1960  * for a given user that can be reached by @fromsid.
1961  * Set *@sids to point to a dynamically allocated
1962  * array containing the set of SIDs.  Set *@nel to the
1963  * number of elements in the array.
1964  */
1965
1966 int security_get_user_sids(u32 fromsid,
1967                            char *username,
1968                            u32 **sids,
1969                            u32 *nel)
1970 {
1971         struct context *fromcon, usercon;
1972         u32 *mysids = NULL, *mysids2, sid;
1973         u32 mynel = 0, maxnel = SIDS_NEL;
1974         struct user_datum *user;
1975         struct role_datum *role;
1976         struct ebitmap_node *rnode, *tnode;
1977         int rc = 0, i, j;
1978
1979         *sids = NULL;
1980         *nel = 0;
1981
1982         if (!ss_initialized)
1983                 goto out;
1984
1985         read_lock(&policy_rwlock);
1986
1987         context_init(&usercon);
1988
1989         fromcon = sidtab_search(&sidtab, fromsid);
1990         if (!fromcon) {
1991                 rc = -EINVAL;
1992                 goto out_unlock;
1993         }
1994
1995         user = hashtab_search(policydb.p_users.table, username);
1996         if (!user) {
1997                 rc = -EINVAL;
1998                 goto out_unlock;
1999         }
2000         usercon.user = user->value;
2001
2002         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2003         if (!mysids) {
2004                 rc = -ENOMEM;
2005                 goto out_unlock;
2006         }
2007
2008         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2009                 role = policydb.role_val_to_struct[i];
2010                 usercon.role = i+1;
2011                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2012                         usercon.type = j+1;
2013
2014                         if (mls_setup_user_range(fromcon, user, &usercon))
2015                                 continue;
2016
2017                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2018                         if (rc)
2019                                 goto out_unlock;
2020                         if (mynel < maxnel) {
2021                                 mysids[mynel++] = sid;
2022                         } else {
2023                                 maxnel += SIDS_NEL;
2024                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2025                                 if (!mysids2) {
2026                                         rc = -ENOMEM;
2027                                         goto out_unlock;
2028                                 }
2029                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2030                                 kfree(mysids);
2031                                 mysids = mysids2;
2032                                 mysids[mynel++] = sid;
2033                         }
2034                 }
2035         }
2036
2037 out_unlock:
2038         read_unlock(&policy_rwlock);
2039         if (rc || !mynel) {
2040                 kfree(mysids);
2041                 goto out;
2042         }
2043
2044         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2045         if (!mysids2) {
2046                 rc = -ENOMEM;
2047                 kfree(mysids);
2048                 goto out;
2049         }
2050         for (i = 0, j = 0; i < mynel; i++) {
2051                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2052                                           SECCLASS_PROCESS, /* kernel value */
2053                                           PROCESS__TRANSITION, AVC_STRICT,
2054                                           NULL);
2055                 if (!rc)
2056                         mysids2[j++] = mysids[i];
2057                 cond_resched();
2058         }
2059         rc = 0;
2060         kfree(mysids);
2061         *sids = mysids2;
2062         *nel = j;
2063 out:
2064         return rc;
2065 }
2066
2067 /**
2068  * security_genfs_sid - Obtain a SID for a file in a filesystem
2069  * @fstype: filesystem type
2070  * @path: path from root of mount
2071  * @sclass: file security class
2072  * @sid: SID for path
2073  *
2074  * Obtain a SID to use for a file in a filesystem that
2075  * cannot support xattr or use a fixed labeling behavior like
2076  * transition SIDs or task SIDs.
2077  */
2078 int security_genfs_sid(const char *fstype,
2079                        char *path,
2080                        u16 orig_sclass,
2081                        u32 *sid)
2082 {
2083         int len;
2084         u16 sclass;
2085         struct genfs *genfs;
2086         struct ocontext *c;
2087         int rc = 0, cmp = 0;
2088
2089         while (path[0] == '/' && path[1] == '/')
2090                 path++;
2091
2092         read_lock(&policy_rwlock);
2093
2094         sclass = unmap_class(orig_sclass);
2095
2096         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2097                 cmp = strcmp(fstype, genfs->fstype);
2098                 if (cmp <= 0)
2099                         break;
2100         }
2101
2102         if (!genfs || cmp) {
2103                 *sid = SECINITSID_UNLABELED;
2104                 rc = -ENOENT;
2105                 goto out;
2106         }
2107
2108         for (c = genfs->head; c; c = c->next) {
2109                 len = strlen(c->u.name);
2110                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2111                     (strncmp(c->u.name, path, len) == 0))
2112                         break;
2113         }
2114
2115         if (!c) {
2116                 *sid = SECINITSID_UNLABELED;
2117                 rc = -ENOENT;
2118                 goto out;
2119         }
2120
2121         if (!c->sid[0]) {
2122                 rc = sidtab_context_to_sid(&sidtab,
2123                                            &c->context[0],
2124                                            &c->sid[0]);
2125                 if (rc)
2126                         goto out;
2127         }
2128
2129         *sid = c->sid[0];
2130 out:
2131         read_unlock(&policy_rwlock);
2132         return rc;
2133 }
2134
2135 /**
2136  * security_fs_use - Determine how to handle labeling for a filesystem.
2137  * @fstype: filesystem type
2138  * @behavior: labeling behavior
2139  * @sid: SID for filesystem (superblock)
2140  */
2141 int security_fs_use(
2142         const char *fstype,
2143         unsigned int *behavior,
2144         u32 *sid)
2145 {
2146         int rc = 0;
2147         struct ocontext *c;
2148
2149         read_lock(&policy_rwlock);
2150
2151         c = policydb.ocontexts[OCON_FSUSE];
2152         while (c) {
2153                 if (strcmp(fstype, c->u.name) == 0)
2154                         break;
2155                 c = c->next;
2156         }
2157
2158         if (c) {
2159                 *behavior = c->v.behavior;
2160                 if (!c->sid[0]) {
2161                         rc = sidtab_context_to_sid(&sidtab,
2162                                                    &c->context[0],
2163                                                    &c->sid[0]);
2164                         if (rc)
2165                                 goto out;
2166                 }
2167                 *sid = c->sid[0];
2168         } else {
2169                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2170                 if (rc) {
2171                         *behavior = SECURITY_FS_USE_NONE;
2172                         rc = 0;
2173                 } else {
2174                         *behavior = SECURITY_FS_USE_GENFS;
2175                 }
2176         }
2177
2178 out:
2179         read_unlock(&policy_rwlock);
2180         return rc;
2181 }
2182
2183 int security_get_bools(int *len, char ***names, int **values)
2184 {
2185         int i, rc = -ENOMEM;
2186
2187         read_lock(&policy_rwlock);
2188         *names = NULL;
2189         *values = NULL;
2190
2191         *len = policydb.p_bools.nprim;
2192         if (!*len) {
2193                 rc = 0;
2194                 goto out;
2195         }
2196
2197        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2198         if (!*names)
2199                 goto err;
2200
2201        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2202         if (!*values)
2203                 goto err;
2204
2205         for (i = 0; i < *len; i++) {
2206                 size_t name_len;
2207                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2208                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2209                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2210                 if (!(*names)[i])
2211                         goto err;
2212                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2213                 (*names)[i][name_len - 1] = 0;
2214         }
2215         rc = 0;
2216 out:
2217         read_unlock(&policy_rwlock);
2218         return rc;
2219 err:
2220         if (*names) {
2221                 for (i = 0; i < *len; i++)
2222                         kfree((*names)[i]);
2223         }
2224         kfree(*values);
2225         goto out;
2226 }
2227
2228
2229 int security_set_bools(int len, int *values)
2230 {
2231         int i, rc = 0;
2232         int lenp, seqno = 0;
2233         struct cond_node *cur;
2234
2235         write_lock_irq(&policy_rwlock);
2236
2237         lenp = policydb.p_bools.nprim;
2238         if (len != lenp) {
2239                 rc = -EFAULT;
2240                 goto out;
2241         }
2242
2243         for (i = 0; i < len; i++) {
2244                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2245                         audit_log(current->audit_context, GFP_ATOMIC,
2246                                 AUDIT_MAC_CONFIG_CHANGE,
2247                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2248                                 policydb.p_bool_val_to_name[i],
2249                                 !!values[i],
2250                                 policydb.bool_val_to_struct[i]->state,
2251                                 audit_get_loginuid(current),
2252                                 audit_get_sessionid(current));
2253                 }
2254                 if (values[i])
2255                         policydb.bool_val_to_struct[i]->state = 1;
2256                 else
2257                         policydb.bool_val_to_struct[i]->state = 0;
2258         }
2259
2260         for (cur = policydb.cond_list; cur; cur = cur->next) {
2261                 rc = evaluate_cond_node(&policydb, cur);
2262                 if (rc)
2263                         goto out;
2264         }
2265
2266         seqno = ++latest_granting;
2267
2268 out:
2269         write_unlock_irq(&policy_rwlock);
2270         if (!rc) {
2271                 avc_ss_reset(seqno);
2272                 selnl_notify_policyload(seqno);
2273                 selinux_xfrm_notify_policyload();
2274         }
2275         return rc;
2276 }
2277
2278 int security_get_bool_value(int bool)
2279 {
2280         int rc = 0;
2281         int len;
2282
2283         read_lock(&policy_rwlock);
2284
2285         len = policydb.p_bools.nprim;
2286         if (bool >= len) {
2287                 rc = -EFAULT;
2288                 goto out;
2289         }
2290
2291         rc = policydb.bool_val_to_struct[bool]->state;
2292 out:
2293         read_unlock(&policy_rwlock);
2294         return rc;
2295 }
2296
2297 static int security_preserve_bools(struct policydb *p)
2298 {
2299         int rc, nbools = 0, *bvalues = NULL, i;
2300         char **bnames = NULL;
2301         struct cond_bool_datum *booldatum;
2302         struct cond_node *cur;
2303
2304         rc = security_get_bools(&nbools, &bnames, &bvalues);
2305         if (rc)
2306                 goto out;
2307         for (i = 0; i < nbools; i++) {
2308                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2309                 if (booldatum)
2310                         booldatum->state = bvalues[i];
2311         }
2312         for (cur = p->cond_list; cur; cur = cur->next) {
2313                 rc = evaluate_cond_node(p, cur);
2314                 if (rc)
2315                         goto out;
2316         }
2317
2318 out:
2319         if (bnames) {
2320                 for (i = 0; i < nbools; i++)
2321                         kfree(bnames[i]);
2322         }
2323         kfree(bnames);
2324         kfree(bvalues);
2325         return rc;
2326 }
2327
2328 /*
2329  * security_sid_mls_copy() - computes a new sid based on the given
2330  * sid and the mls portion of mls_sid.
2331  */
2332 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2333 {
2334         struct context *context1;
2335         struct context *context2;
2336         struct context newcon;
2337         char *s;
2338         u32 len;
2339         int rc = 0;
2340
2341         if (!ss_initialized || !selinux_mls_enabled) {
2342                 *new_sid = sid;
2343                 goto out;
2344         }
2345
2346         context_init(&newcon);
2347
2348         read_lock(&policy_rwlock);
2349         context1 = sidtab_search(&sidtab, sid);
2350         if (!context1) {
2351                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2352                         __func__, sid);
2353                 rc = -EINVAL;
2354                 goto out_unlock;
2355         }
2356
2357         context2 = sidtab_search(&sidtab, mls_sid);
2358         if (!context2) {
2359                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2360                         __func__, mls_sid);
2361                 rc = -EINVAL;
2362                 goto out_unlock;
2363         }
2364
2365         newcon.user = context1->user;
2366         newcon.role = context1->role;
2367         newcon.type = context1->type;
2368         rc = mls_context_cpy(&newcon, context2);
2369         if (rc)
2370                 goto out_unlock;
2371
2372         /* Check the validity of the new context. */
2373         if (!policydb_context_isvalid(&policydb, &newcon)) {
2374                 rc = convert_context_handle_invalid_context(&newcon);
2375                 if (rc)
2376                         goto bad;
2377         }
2378
2379         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2380         goto out_unlock;
2381
2382 bad:
2383         if (!context_struct_to_string(&newcon, &s, &len)) {
2384                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2385                           "security_sid_mls_copy: invalid context %s", s);
2386                 kfree(s);
2387         }
2388
2389 out_unlock:
2390         read_unlock(&policy_rwlock);
2391         context_destroy(&newcon);
2392 out:
2393         return rc;
2394 }
2395
2396 /**
2397  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2398  * @nlbl_sid: NetLabel SID
2399  * @nlbl_type: NetLabel labeling protocol type
2400  * @xfrm_sid: XFRM SID
2401  *
2402  * Description:
2403  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2404  * resolved into a single SID it is returned via @peer_sid and the function
2405  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2406  * returns a negative value.  A table summarizing the behavior is below:
2407  *
2408  *                                 | function return |      @sid
2409  *   ------------------------------+-----------------+-----------------
2410  *   no peer labels                |        0        |    SECSID_NULL
2411  *   single peer label             |        0        |    <peer_label>
2412  *   multiple, consistent labels   |        0        |    <peer_label>
2413  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2414  *
2415  */
2416 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2417                                  u32 xfrm_sid,
2418                                  u32 *peer_sid)
2419 {
2420         int rc;
2421         struct context *nlbl_ctx;
2422         struct context *xfrm_ctx;
2423
2424         /* handle the common (which also happens to be the set of easy) cases
2425          * right away, these two if statements catch everything involving a
2426          * single or absent peer SID/label */
2427         if (xfrm_sid == SECSID_NULL) {
2428                 *peer_sid = nlbl_sid;
2429                 return 0;
2430         }
2431         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2432          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2433          * is present */
2434         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2435                 *peer_sid = xfrm_sid;
2436                 return 0;
2437         }
2438
2439         /* we don't need to check ss_initialized here since the only way both
2440          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2441          * security server was initialized and ss_initialized was true */
2442         if (!selinux_mls_enabled) {
2443                 *peer_sid = SECSID_NULL;
2444                 return 0;
2445         }
2446
2447         read_lock(&policy_rwlock);
2448
2449         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2450         if (!nlbl_ctx) {
2451                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2452                        __func__, nlbl_sid);
2453                 rc = -EINVAL;
2454                 goto out_slowpath;
2455         }
2456         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2457         if (!xfrm_ctx) {
2458                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2459                        __func__, xfrm_sid);
2460                 rc = -EINVAL;
2461                 goto out_slowpath;
2462         }
2463         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2464
2465 out_slowpath:
2466         read_unlock(&policy_rwlock);
2467         if (rc == 0)
2468                 /* at present NetLabel SIDs/labels really only carry MLS
2469                  * information so if the MLS portion of the NetLabel SID
2470                  * matches the MLS portion of the labeled XFRM SID/label
2471                  * then pass along the XFRM SID as it is the most
2472                  * expressive */
2473                 *peer_sid = xfrm_sid;
2474         else
2475                 *peer_sid = SECSID_NULL;
2476         return rc;
2477 }
2478
2479 static int get_classes_callback(void *k, void *d, void *args)
2480 {
2481         struct class_datum *datum = d;
2482         char *name = k, **classes = args;
2483         int value = datum->value - 1;
2484
2485         classes[value] = kstrdup(name, GFP_ATOMIC);
2486         if (!classes[value])
2487                 return -ENOMEM;
2488
2489         return 0;
2490 }
2491
2492 int security_get_classes(char ***classes, int *nclasses)
2493 {
2494         int rc = -ENOMEM;
2495
2496         read_lock(&policy_rwlock);
2497
2498         *nclasses = policydb.p_classes.nprim;
2499         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2500         if (!*classes)
2501                 goto out;
2502
2503         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2504                         *classes);
2505         if (rc < 0) {
2506                 int i;
2507                 for (i = 0; i < *nclasses; i++)
2508                         kfree((*classes)[i]);
2509                 kfree(*classes);
2510         }
2511
2512 out:
2513         read_unlock(&policy_rwlock);
2514         return rc;
2515 }
2516
2517 static int get_permissions_callback(void *k, void *d, void *args)
2518 {
2519         struct perm_datum *datum = d;
2520         char *name = k, **perms = args;
2521         int value = datum->value - 1;
2522
2523         perms[value] = kstrdup(name, GFP_ATOMIC);
2524         if (!perms[value])
2525                 return -ENOMEM;
2526
2527         return 0;
2528 }
2529
2530 int security_get_permissions(char *class, char ***perms, int *nperms)
2531 {
2532         int rc = -ENOMEM, i;
2533         struct class_datum *match;
2534
2535         read_lock(&policy_rwlock);
2536
2537         match = hashtab_search(policydb.p_classes.table, class);
2538         if (!match) {
2539                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2540                         __func__, class);
2541                 rc = -EINVAL;
2542                 goto out;
2543         }
2544
2545         *nperms = match->permissions.nprim;
2546         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2547         if (!*perms)
2548                 goto out;
2549
2550         if (match->comdatum) {
2551                 rc = hashtab_map(match->comdatum->permissions.table,
2552                                 get_permissions_callback, *perms);
2553                 if (rc < 0)
2554                         goto err;
2555         }
2556
2557         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2558                         *perms);
2559         if (rc < 0)
2560                 goto err;
2561
2562 out:
2563         read_unlock(&policy_rwlock);
2564         return rc;
2565
2566 err:
2567         read_unlock(&policy_rwlock);
2568         for (i = 0; i < *nperms; i++)
2569                 kfree((*perms)[i]);
2570         kfree(*perms);
2571         return rc;
2572 }
2573
2574 int security_get_reject_unknown(void)
2575 {
2576         return policydb.reject_unknown;
2577 }
2578
2579 int security_get_allow_unknown(void)
2580 {
2581         return policydb.allow_unknown;
2582 }
2583
2584 /**
2585  * security_policycap_supported - Check for a specific policy capability
2586  * @req_cap: capability
2587  *
2588  * Description:
2589  * This function queries the currently loaded policy to see if it supports the
2590  * capability specified by @req_cap.  Returns true (1) if the capability is
2591  * supported, false (0) if it isn't supported.
2592  *
2593  */
2594 int security_policycap_supported(unsigned int req_cap)
2595 {
2596         int rc;
2597
2598         read_lock(&policy_rwlock);
2599         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2600         read_unlock(&policy_rwlock);
2601
2602         return rc;
2603 }
2604
2605 struct selinux_audit_rule {
2606         u32 au_seqno;
2607         struct context au_ctxt;
2608 };
2609
2610 void selinux_audit_rule_free(void *vrule)
2611 {
2612         struct selinux_audit_rule *rule = vrule;
2613
2614         if (rule) {
2615                 context_destroy(&rule->au_ctxt);
2616                 kfree(rule);
2617         }
2618 }
2619
2620 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2621 {
2622         struct selinux_audit_rule *tmprule;
2623         struct role_datum *roledatum;
2624         struct type_datum *typedatum;
2625         struct user_datum *userdatum;
2626         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2627         int rc = 0;
2628
2629         *rule = NULL;
2630
2631         if (!ss_initialized)
2632                 return -EOPNOTSUPP;
2633
2634         switch (field) {
2635         case AUDIT_SUBJ_USER:
2636         case AUDIT_SUBJ_ROLE:
2637         case AUDIT_SUBJ_TYPE:
2638         case AUDIT_OBJ_USER:
2639         case AUDIT_OBJ_ROLE:
2640         case AUDIT_OBJ_TYPE:
2641                 /* only 'equals' and 'not equals' fit user, role, and type */
2642                 if (op != Audit_equal && op != Audit_not_equal)
2643                         return -EINVAL;
2644                 break;
2645         case AUDIT_SUBJ_SEN:
2646         case AUDIT_SUBJ_CLR:
2647         case AUDIT_OBJ_LEV_LOW:
2648         case AUDIT_OBJ_LEV_HIGH:
2649                 /* we do not allow a range, indicated by the presense of '-' */
2650                 if (strchr(rulestr, '-'))
2651                         return -EINVAL;
2652                 break;
2653         default:
2654                 /* only the above fields are valid */
2655                 return -EINVAL;
2656         }
2657
2658         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2659         if (!tmprule)
2660                 return -ENOMEM;
2661
2662         context_init(&tmprule->au_ctxt);
2663
2664         read_lock(&policy_rwlock);
2665
2666         tmprule->au_seqno = latest_granting;
2667
2668         switch (field) {
2669         case AUDIT_SUBJ_USER:
2670         case AUDIT_OBJ_USER:
2671                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2672                 if (!userdatum)
2673                         rc = -EINVAL;
2674                 else
2675                         tmprule->au_ctxt.user = userdatum->value;
2676                 break;
2677         case AUDIT_SUBJ_ROLE:
2678         case AUDIT_OBJ_ROLE:
2679                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2680                 if (!roledatum)
2681                         rc = -EINVAL;
2682                 else
2683                         tmprule->au_ctxt.role = roledatum->value;
2684                 break;
2685         case AUDIT_SUBJ_TYPE:
2686         case AUDIT_OBJ_TYPE:
2687                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2688                 if (!typedatum)
2689                         rc = -EINVAL;
2690                 else
2691                         tmprule->au_ctxt.type = typedatum->value;
2692                 break;
2693         case AUDIT_SUBJ_SEN:
2694         case AUDIT_SUBJ_CLR:
2695         case AUDIT_OBJ_LEV_LOW:
2696         case AUDIT_OBJ_LEV_HIGH:
2697                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2698                 break;
2699         }
2700
2701         read_unlock(&policy_rwlock);
2702
2703         if (rc) {
2704                 selinux_audit_rule_free(tmprule);
2705                 tmprule = NULL;
2706         }
2707
2708         *rule = tmprule;
2709
2710         return rc;
2711 }
2712
2713 /* Check to see if the rule contains any selinux fields */
2714 int selinux_audit_rule_known(struct audit_krule *rule)
2715 {
2716         int i;
2717
2718         for (i = 0; i < rule->field_count; i++) {
2719                 struct audit_field *f = &rule->fields[i];
2720                 switch (f->type) {
2721                 case AUDIT_SUBJ_USER:
2722                 case AUDIT_SUBJ_ROLE:
2723                 case AUDIT_SUBJ_TYPE:
2724                 case AUDIT_SUBJ_SEN:
2725                 case AUDIT_SUBJ_CLR:
2726                 case AUDIT_OBJ_USER:
2727                 case AUDIT_OBJ_ROLE:
2728                 case AUDIT_OBJ_TYPE:
2729                 case AUDIT_OBJ_LEV_LOW:
2730                 case AUDIT_OBJ_LEV_HIGH:
2731                         return 1;
2732                 }
2733         }
2734
2735         return 0;
2736 }
2737
2738 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2739                              struct audit_context *actx)
2740 {
2741         struct context *ctxt;
2742         struct mls_level *level;
2743         struct selinux_audit_rule *rule = vrule;
2744         int match = 0;
2745
2746         if (!rule) {
2747                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2748                           "selinux_audit_rule_match: missing rule\n");
2749                 return -ENOENT;
2750         }
2751
2752         read_lock(&policy_rwlock);
2753
2754         if (rule->au_seqno < latest_granting) {
2755                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2756                           "selinux_audit_rule_match: stale rule\n");
2757                 match = -ESTALE;
2758                 goto out;
2759         }
2760
2761         ctxt = sidtab_search(&sidtab, sid);
2762         if (!ctxt) {
2763                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2764                           "selinux_audit_rule_match: unrecognized SID %d\n",
2765                           sid);
2766                 match = -ENOENT;
2767                 goto out;
2768         }
2769
2770         /* a field/op pair that is not caught here will simply fall through
2771            without a match */
2772         switch (field) {
2773         case AUDIT_SUBJ_USER:
2774         case AUDIT_OBJ_USER:
2775                 switch (op) {
2776                 case Audit_equal:
2777                         match = (ctxt->user == rule->au_ctxt.user);
2778                         break;
2779                 case Audit_not_equal:
2780                         match = (ctxt->user != rule->au_ctxt.user);
2781                         break;
2782                 }
2783                 break;
2784         case AUDIT_SUBJ_ROLE:
2785         case AUDIT_OBJ_ROLE:
2786                 switch (op) {
2787                 case Audit_equal:
2788                         match = (ctxt->role == rule->au_ctxt.role);
2789                         break;
2790                 case Audit_not_equal:
2791                         match = (ctxt->role != rule->au_ctxt.role);
2792                         break;
2793                 }
2794                 break;
2795         case AUDIT_SUBJ_TYPE:
2796         case AUDIT_OBJ_TYPE:
2797                 switch (op) {
2798                 case Audit_equal:
2799                         match = (ctxt->type == rule->au_ctxt.type);
2800                         break;
2801                 case Audit_not_equal:
2802                         match = (ctxt->type != rule->au_ctxt.type);
2803                         break;
2804                 }
2805                 break;
2806         case AUDIT_SUBJ_SEN:
2807         case AUDIT_SUBJ_CLR:
2808         case AUDIT_OBJ_LEV_LOW:
2809         case AUDIT_OBJ_LEV_HIGH:
2810                 level = ((field == AUDIT_SUBJ_SEN ||
2811                           field == AUDIT_OBJ_LEV_LOW) ?
2812                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2813                 switch (op) {
2814                 case Audit_equal:
2815                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2816                                              level);
2817                         break;
2818                 case Audit_not_equal:
2819                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2820                                               level);
2821                         break;
2822                 case Audit_lt:
2823                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2824                                                level) &&
2825                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2826                                                level));
2827                         break;
2828                 case Audit_le:
2829                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2830                                               level);
2831                         break;
2832                 case Audit_gt:
2833                         match = (mls_level_dom(level,
2834                                               &rule->au_ctxt.range.level[0]) &&
2835                                  !mls_level_eq(level,
2836                                                &rule->au_ctxt.range.level[0]));
2837                         break;
2838                 case Audit_ge:
2839                         match = mls_level_dom(level,
2840                                               &rule->au_ctxt.range.level[0]);
2841                         break;
2842                 }
2843         }
2844
2845 out:
2846         read_unlock(&policy_rwlock);
2847         return match;
2848 }
2849
2850 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2851
2852 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2853                                u16 class, u32 perms, u32 *retained)
2854 {
2855         int err = 0;
2856
2857         if (event == AVC_CALLBACK_RESET && aurule_callback)
2858                 err = aurule_callback();
2859         return err;
2860 }
2861
2862 static int __init aurule_init(void)
2863 {
2864         int err;
2865
2866         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2867                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2868         if (err)
2869                 panic("avc_add_callback() failed, error %d\n", err);
2870
2871         return err;
2872 }
2873 __initcall(aurule_init);
2874
2875 #ifdef CONFIG_NETLABEL
2876 /**
2877  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2878  * @secattr: the NetLabel packet security attributes
2879  * @sid: the SELinux SID
2880  *
2881  * Description:
2882  * Attempt to cache the context in @ctx, which was derived from the packet in
2883  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2884  * already been initialized.
2885  *
2886  */
2887 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2888                                       u32 sid)
2889 {
2890         u32 *sid_cache;
2891
2892         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2893         if (sid_cache == NULL)
2894                 return;
2895         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2896         if (secattr->cache == NULL) {
2897                 kfree(sid_cache);
2898                 return;
2899         }
2900
2901         *sid_cache = sid;
2902         secattr->cache->free = kfree;
2903         secattr->cache->data = sid_cache;
2904         secattr->flags |= NETLBL_SECATTR_CACHE;
2905 }
2906
2907 /**
2908  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2909  * @secattr: the NetLabel packet security attributes
2910  * @sid: the SELinux SID
2911  *
2912  * Description:
2913  * Convert the given NetLabel security attributes in @secattr into a
2914  * SELinux SID.  If the @secattr field does not contain a full SELinux
2915  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2916  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2917  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2918  * conversion for future lookups.  Returns zero on success, negative values on
2919  * failure.
2920  *
2921  */
2922 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2923                                    u32 *sid)
2924 {
2925         int rc = -EIDRM;
2926         struct context *ctx;
2927         struct context ctx_new;
2928
2929         if (!ss_initialized) {
2930                 *sid = SECSID_NULL;
2931                 return 0;
2932         }
2933
2934         read_lock(&policy_rwlock);
2935
2936         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2937                 *sid = *(u32 *)secattr->cache->data;
2938                 rc = 0;
2939         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2940                 *sid = secattr->attr.secid;
2941                 rc = 0;
2942         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2943                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2944                 if (ctx == NULL)
2945                         goto netlbl_secattr_to_sid_return;
2946
2947                 context_init(&ctx_new);
2948                 ctx_new.user = ctx->user;
2949                 ctx_new.role = ctx->role;
2950                 ctx_new.type = ctx->type;
2951                 mls_import_netlbl_lvl(&ctx_new, secattr);
2952                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2953                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2954                                                   secattr->attr.mls.cat) != 0)
2955                                 goto netlbl_secattr_to_sid_return;
2956                         memcpy(&ctx_new.range.level[1].cat,
2957                                &ctx_new.range.level[0].cat,
2958                                sizeof(ctx_new.range.level[0].cat));
2959                 }
2960                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2961                         goto netlbl_secattr_to_sid_return_cleanup;
2962
2963                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2964                 if (rc != 0)
2965                         goto netlbl_secattr_to_sid_return_cleanup;
2966
2967                 security_netlbl_cache_add(secattr, *sid);
2968
2969                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2970         } else {
2971                 *sid = SECSID_NULL;
2972                 rc = 0;
2973         }
2974
2975 netlbl_secattr_to_sid_return:
2976         read_unlock(&policy_rwlock);
2977         return rc;
2978 netlbl_secattr_to_sid_return_cleanup:
2979         ebitmap_destroy(&ctx_new.range.level[0].cat);
2980         goto netlbl_secattr_to_sid_return;
2981 }
2982
2983 /**
2984  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2985  * @sid: the SELinux SID
2986  * @secattr: the NetLabel packet security attributes
2987  *
2988  * Description:
2989  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2990  * Returns zero on success, negative values on failure.
2991  *
2992  */
2993 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2994 {
2995         int rc;
2996         struct context *ctx;
2997
2998         if (!ss_initialized)
2999                 return 0;
3000
3001         read_lock(&policy_rwlock);
3002         ctx = sidtab_search(&sidtab, sid);
3003         if (ctx == NULL) {
3004                 rc = -ENOENT;
3005                 goto netlbl_sid_to_secattr_failure;
3006         }
3007         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
3008                                   GFP_ATOMIC);
3009         if (secattr->domain == NULL) {
3010                 rc = -ENOMEM;
3011                 goto netlbl_sid_to_secattr_failure;
3012         }
3013         secattr->attr.secid = sid;
3014         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3015         mls_export_netlbl_lvl(ctx, secattr);
3016         rc = mls_export_netlbl_cat(ctx, secattr);
3017         if (rc != 0)
3018                 goto netlbl_sid_to_secattr_failure;
3019         read_unlock(&policy_rwlock);
3020
3021         return 0;
3022
3023 netlbl_sid_to_secattr_failure:
3024         read_unlock(&policy_rwlock);
3025         return rc;
3026 }
3027 #endif /* CONFIG_NETLABEL */