security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
   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@paul-moore.com>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <csellers@tresys.com>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <guido@trentalancia.com>
  30  *
  31  *  Added support for runtime switching of the policy type
  32  *
  33  * Copyright (C) 2008, 2009 NEC Corporation
  34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  38  *      This program is free software; you can redistribute it and/or modify
  39  *      it under the terms of the GNU General Public License as published by
  40  *      the Free Software Foundation, version 2.
  41  */
  42 #include <linux/kernel.h>
  43 #include <linux/slab.h>
  44 #include <linux/string.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/errno.h>
  48 #include <linux/in.h>
  49 #include <linux/sched.h>
  50 #include <linux/audit.h>
  51 #include <linux/mutex.h>
  52 #include <linux/selinux.h>
  53 #include <linux/flex_array.h>
  54 #include <linux/vmalloc.h>
  55 #include <net/netlabel.h>
  56
  57 #include "flask.h"
  58 #include "avc.h"
  59 #include "avc_ss.h"
  60 #include "security.h"
  61 #include "context.h"
  62 #include "policydb.h"
  63 #include "sidtab.h"
  64 #include "services.h"
  65 #include "conditional.h"
  66 #include "mls.h"
  67 #include "objsec.h"
  68 #include "netlabel.h"
  69 #include "xfrm.h"
  70 #include "ebitmap.h"
  71 #include "audit.h"
  72
  73 /* Policy capability names */
  74 char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
  75         "network_peer_controls",
  76         "open_perms",
  77         "extended_socket_class",
  78         "always_check_network",
  79         "cgroup_seclabel",
  80         "nnp_nosuid_transition"
  81 };
  82
  83 static struct selinux_ss selinux_ss;
  84
  85 void selinux_ss_init(struct selinux_ss **ss)
  86 {
  87         rwlock_init(&selinux_ss.policy_rwlock);
  88         mutex_init(&selinux_ss.status_lock);
  89         *ss = &selinux_ss;
  90 }
  91
  92 /* Forward declaration. */
  93 static int context_struct_to_string(struct policydb *policydb,
  94                                     struct context *context,
  95                                     char **scontext,
  96                                     u32 *scontext_len);
  97
  98 static void context_struct_compute_av(struct policydb *policydb,
  99                                       struct context *scontext,
 100                                       struct context *tcontext,
 101                                       u16 tclass,
 102                                       struct av_decision *avd,
 103                                       struct extended_perms *xperms);
 104
 105 static int selinux_set_mapping(struct policydb *pol,
 106                                struct security_class_mapping *map,
 107                                struct selinux_map *out_map)
 108 {
 109         u16 i, j;
 110         unsigned k;
 111         bool print_unknown_handle = false;
 112
 113         /* Find number of classes in the input mapping */
 114         if (!map)
 115                 return -EINVAL;
 116         i = 0;
 117         while (map[i].name)
 118                 i++;
 119
 120         /* Allocate space for the class records, plus one for class zero */
 121         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 122         if (!out_map->mapping)
 123                 return -ENOMEM;
 124
 125         /* Store the raw class and permission values */
 126         j = 0;
 127         while (map[j].name) {
 128                 struct security_class_mapping *p_in = map + (j++);
 129                 struct selinux_mapping *p_out = out_map->mapping + j;
 130
 131                 /* An empty class string skips ahead */
 132                 if (!strcmp(p_in->name, "")) {
 133                         p_out->num_perms = 0;
 134                         continue;
 135                 }
 136
 137                 p_out->value = string_to_security_class(pol, p_in->name);
 138                 if (!p_out->value) {
 139                         pr_info("SELinux:  Class %s not defined in policy.\n",
 140                                p_in->name);
 141                         if (pol->reject_unknown)
 142                                 goto err;
 143                         p_out->num_perms = 0;
 144                         print_unknown_handle = true;
 145                         continue;
 146                 }
 147
 148                 k = 0;
 149                 while (p_in->perms[k]) {
 150                         /* An empty permission string skips ahead */
 151                         if (!*p_in->perms[k]) {
 152                                 k++;
 153                                 continue;
 154                         }
 155                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 156                                                             p_in->perms[k]);
 157                         if (!p_out->perms[k]) {
 158                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 159                                        p_in->perms[k], p_in->name);
 160                                 if (pol->reject_unknown)
 161                                         goto err;
 162                                 print_unknown_handle = true;
 163                         }
 164
 165                         k++;
 166                 }
 167                 p_out->num_perms = k;
 168         }
 169
 170         if (print_unknown_handle)
 171                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 172                        pol->allow_unknown ? "allowed" : "denied");
 173
 174         out_map->size = i;
 175         return 0;
 176 err:
 177         kfree(out_map->mapping);
 178         out_map->mapping = NULL;
 179         return -EINVAL;
 180 }
 181
 182 /*
 183  * Get real, policy values from mapped values
 184  */
 185
 186 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 187 {
 188         if (tclass < map->size)
 189                 return map->mapping[tclass].value;
 190
 191         return tclass;
 192 }
 193
 194 /*
 195  * Get kernel value for class from its policy value
 196  */
 197 static u16 map_class(struct selinux_map *map, u16 pol_value)
 198 {
 199         u16 i;
 200
 201         for (i = 1; i < map->size; i++) {
 202                 if (map->mapping[i].value == pol_value)
 203                         return i;
 204         }
 205
 206         return SECCLASS_NULL;
 207 }
 208
 209 static void map_decision(struct selinux_map *map,
 210                          u16 tclass, struct av_decision *avd,
 211                          int allow_unknown)
 212 {
 213         if (tclass < map->size) {
 214                 struct selinux_mapping *mapping = &map->mapping[tclass];
 215                 unsigned int i, n = mapping->num_perms;
 216                 u32 result;
 217
 218                 for (i = 0, result = 0; i < n; i++) {
 219                         if (avd->allowed & mapping->perms[i])
 220                                 result |= 1<<i;
 221                         if (allow_unknown && !mapping->perms[i])
 222                                 result |= 1<<i;
 223                 }
 224                 avd->allowed = result;
 225
 226                 for (i = 0, result = 0; i < n; i++)
 227                         if (avd->auditallow & mapping->perms[i])
 228                                 result |= 1<<i;
 229                 avd->auditallow = result;
 230
 231                 for (i = 0, result = 0; i < n; i++) {
 232                         if (avd->auditdeny & mapping->perms[i])
 233                                 result |= 1<<i;
 234                         if (!allow_unknown && !mapping->perms[i])
 235                                 result |= 1<<i;
 236                 }
 237                 /*
 238                  * In case the kernel has a bug and requests a permission
 239                  * between num_perms and the maximum permission number, we
 240                  * should audit that denial
 241                  */
 242                 for (; i < (sizeof(u32)*8); i++)
 243                         result |= 1<<i;
 244                 avd->auditdeny = result;
 245         }
 246 }
 247
 248 int security_mls_enabled(struct selinux_state *state)
 249 {
 250         struct policydb *p = &state->ss->policydb;
 251
 252         return p->mls_enabled;
 253 }
 254
 255 /*
 256  * Return the boolean value of a constraint expression
 257  * when it is applied to the specified source and target
 258  * security contexts.
 259  *
 260  * xcontext is a special beast...  It is used by the validatetrans rules
 261  * only.  For these rules, scontext is the context before the transition,
 262  * tcontext is the context after the transition, and xcontext is the context
 263  * of the process performing the transition.  All other callers of
 264  * constraint_expr_eval should pass in NULL for xcontext.
 265  */
 266 static int constraint_expr_eval(struct policydb *policydb,
 267                                 struct context *scontext,
 268                                 struct context *tcontext,
 269                                 struct context *xcontext,
 270                                 struct constraint_expr *cexpr)
 271 {
 272         u32 val1, val2;
 273         struct context *c;
 274         struct role_datum *r1, *r2;
 275         struct mls_level *l1, *l2;
 276         struct constraint_expr *e;
 277         int s[CEXPR_MAXDEPTH];
 278         int sp = -1;
 279
 280         for (e = cexpr; e; e = e->next) {
 281                 switch (e->expr_type) {
 282                 case CEXPR_NOT:
 283                         BUG_ON(sp < 0);
 284                         s[sp] = !s[sp];
 285                         break;
 286                 case CEXPR_AND:
 287                         BUG_ON(sp < 1);
 288                         sp--;
 289                         s[sp] &= s[sp + 1];
 290                         break;
 291                 case CEXPR_OR:
 292                         BUG_ON(sp < 1);
 293                         sp--;
 294                         s[sp] |= s[sp + 1];
 295                         break;
 296                 case CEXPR_ATTR:
 297                         if (sp == (CEXPR_MAXDEPTH - 1))
 298                                 return 0;
 299                         switch (e->attr) {
 300                         case CEXPR_USER:
 301                                 val1 = scontext->user;
 302                                 val2 = tcontext->user;
 303                                 break;
 304                         case CEXPR_TYPE:
 305                                 val1 = scontext->type;
 306                                 val2 = tcontext->type;
 307                                 break;
 308                         case CEXPR_ROLE:
 309                                 val1 = scontext->role;
 310                                 val2 = tcontext->role;
 311                                 r1 = policydb->role_val_to_struct[val1 - 1];
 312                                 r2 = policydb->role_val_to_struct[val2 - 1];
 313                                 switch (e->op) {
 314                                 case CEXPR_DOM:
 315                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 316                                                                   val2 - 1);
 317                                         continue;
 318                                 case CEXPR_DOMBY:
 319                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 320                                                                   val1 - 1);
 321                                         continue;
 322                                 case CEXPR_INCOMP:
 323                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 324                                                                     val2 - 1) &&
 325                                                    !ebitmap_get_bit(&r2->dominates,
 326                                                                     val1 - 1));
 327                                         continue;
 328                                 default:
 329                                         break;
 330                                 }
 331                                 break;
 332                         case CEXPR_L1L2:
 333                                 l1 = &(scontext->range.level[0]);
 334                                 l2 = &(tcontext->range.level[0]);
 335                                 goto mls_ops;
 336                         case CEXPR_L1H2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[1]);
 339                                 goto mls_ops;
 340                         case CEXPR_H1L2:
 341                                 l1 = &(scontext->range.level[1]);
 342                                 l2 = &(tcontext->range.level[0]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1H2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[1]);
 347                                 goto mls_ops;
 348                         case CEXPR_L1H1:
 349                                 l1 = &(scontext->range.level[0]);
 350                                 l2 = &(scontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L2H2:
 353                                 l1 = &(tcontext->range.level[0]);
 354                                 l2 = &(tcontext->range.level[1]);
 355                                 goto mls_ops;
 356 mls_ops:
 357                         switch (e->op) {
 358                         case CEXPR_EQ:
 359                                 s[++sp] = mls_level_eq(l1, l2);
 360                                 continue;
 361                         case CEXPR_NEQ:
 362                                 s[++sp] = !mls_level_eq(l1, l2);
 363                                 continue;
 364                         case CEXPR_DOM:
 365                                 s[++sp] = mls_level_dom(l1, l2);
 366                                 continue;
 367                         case CEXPR_DOMBY:
 368                                 s[++sp] = mls_level_dom(l2, l1);
 369                                 continue;
 370                         case CEXPR_INCOMP:
 371                                 s[++sp] = mls_level_incomp(l2, l1);
 372                                 continue;
 373                         default:
 374                                 BUG();
 375                                 return 0;
 376                         }
 377                         break;
 378                         default:
 379                                 BUG();
 380                                 return 0;
 381                         }
 382
 383                         switch (e->op) {
 384                         case CEXPR_EQ:
 385                                 s[++sp] = (val1 == val2);
 386                                 break;
 387                         case CEXPR_NEQ:
 388                                 s[++sp] = (val1 != val2);
 389                                 break;
 390                         default:
 391                                 BUG();
 392                                 return 0;
 393                         }
 394                         break;
 395                 case CEXPR_NAMES:
 396                         if (sp == (CEXPR_MAXDEPTH-1))
 397                                 return 0;
 398                         c = scontext;
 399                         if (e->attr & CEXPR_TARGET)
 400                                 c = tcontext;
 401                         else if (e->attr & CEXPR_XTARGET) {
 402                                 c = xcontext;
 403                                 if (!c) {
 404                                         BUG();
 405                                         return 0;
 406                                 }
 407                         }
 408                         if (e->attr & CEXPR_USER)
 409                                 val1 = c->user;
 410                         else if (e->attr & CEXPR_ROLE)
 411                                 val1 = c->role;
 412                         else if (e->attr & CEXPR_TYPE)
 413                                 val1 = c->type;
 414                         else {
 415                                 BUG();
 416                                 return 0;
 417                         }
 418
 419                         switch (e->op) {
 420                         case CEXPR_EQ:
 421                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 422                                 break;
 423                         case CEXPR_NEQ:
 424                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 425                                 break;
 426                         default:
 427                                 BUG();
 428                                 return 0;
 429                         }
 430                         break;
 431                 default:
 432                         BUG();
 433                         return 0;
 434                 }
 435         }
 436
 437         BUG_ON(sp != 0);
 438         return s[0];
 439 }
 440
 441 /*
 442  * security_dump_masked_av - dumps masked permissions during
 443  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 444  */
 445 static int dump_masked_av_helper(void *k, void *d, void *args)
 446 {
 447         struct perm_datum *pdatum = d;
 448         char **permission_names = args;
 449
 450         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 451
 452         permission_names[pdatum->value - 1] = (char *)k;
 453
 454         return 0;
 455 }
 456
 457 static void security_dump_masked_av(struct policydb *policydb,
 458                                     struct context *scontext,
 459                                     struct context *tcontext,
 460                                     u16 tclass,
 461                                     u32 permissions,
 462                                     const char *reason)
 463 {
 464         struct common_datum *common_dat;
 465         struct class_datum *tclass_dat;
 466         struct audit_buffer *ab;
 467         char *tclass_name;
 468         char *scontext_name = NULL;
 469         char *tcontext_name = NULL;
 470         char *permission_names[32];
 471         int index;
 472         u32 length;
 473         bool need_comma = false;
 474
 475         if (!permissions)
 476                 return;
 477
 478         tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
 479         tclass_dat = policydb->class_val_to_struct[tclass - 1];
 480         common_dat = tclass_dat->comdatum;
 481
 482         /* init permission_names */
 483         if (common_dat &&
 484             hashtab_map(common_dat->permissions.table,
 485                         dump_masked_av_helper, permission_names) < 0)
 486                 goto out;
 487
 488         if (hashtab_map(tclass_dat->permissions.table,
 489                         dump_masked_av_helper, permission_names) < 0)
 490                 goto out;
 491
 492         /* get scontext/tcontext in text form */
 493         if (context_struct_to_string(policydb, scontext,
 494                                      &scontext_name, &length) < 0)
 495                 goto out;
 496
 497         if (context_struct_to_string(policydb, tcontext,
 498                                      &tcontext_name, &length) < 0)
 499                 goto out;
 500
 501         /* audit a message */
 502         ab = audit_log_start(audit_context(),
 503                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 504         if (!ab)
 505                 goto out;
 506
 507         audit_log_format(ab, "op=security_compute_av reason=%s "
 508                          "scontext=%s tcontext=%s tclass=%s perms=",
 509                          reason, scontext_name, tcontext_name, tclass_name);
 510
 511         for (index = 0; index < 32; index++) {
 512                 u32 mask = (1 << index);
 513
 514                 if ((mask & permissions) == 0)
 515                         continue;
 516
 517                 audit_log_format(ab, "%s%s",
 518                                  need_comma ? "," : "",
 519                                  permission_names[index]
 520                                  ? permission_names[index] : "????");
 521                 need_comma = true;
 522         }
 523         audit_log_end(ab);
 524 out:
 525         /* release scontext/tcontext */
 526         kfree(tcontext_name);
 527         kfree(scontext_name);
 528
 529         return;
 530 }
 531
 532 /*
 533  * security_boundary_permission - drops violated permissions
 534  * on boundary constraint.
 535  */
 536 static void type_attribute_bounds_av(struct policydb *policydb,
 537                                      struct context *scontext,
 538                                      struct context *tcontext,
 539                                      u16 tclass,
 540                                      struct av_decision *avd)
 541 {
 542         struct context lo_scontext;
 543         struct context lo_tcontext, *tcontextp = tcontext;
 544         struct av_decision lo_avd;
 545         struct type_datum *source;
 546         struct type_datum *target;
 547         u32 masked = 0;
 548
 549         source = flex_array_get_ptr(policydb->type_val_to_struct_array,
 550                                     scontext->type - 1);
 551         BUG_ON(!source);
 552
 553         if (!source->bounds)
 554                 return;
 555
 556         target = flex_array_get_ptr(policydb->type_val_to_struct_array,
 557                                     tcontext->type - 1);
 558         BUG_ON(!target);
 559
 560         memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563         lo_scontext.type = source->bounds;
 564
 565         if (target->bounds) {
 566                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 567                 lo_tcontext.type = target->bounds;
 568                 tcontextp = &lo_tcontext;
 569         }
 570
 571         context_struct_compute_av(policydb, &lo_scontext,
 572                                   tcontextp,
 573                                   tclass,
 574                                   &lo_avd,
 575                                   NULL);
 576
 577         masked = ~lo_avd.allowed & avd->allowed;
 578
 579         if (likely(!masked))
 580                 return;         /* no masked permission */
 581
 582         /* mask violated permissions */
 583         avd->allowed &= ~masked;
 584
 585         /* audit masked permissions */
 586         security_dump_masked_av(policydb, scontext, tcontext,
 587                                 tclass, masked, "bounds");
 588 }
 589
 590 /*
 591  * flag which drivers have permissions
 592  * only looking for ioctl based extended permssions
 593  */
 594 void services_compute_xperms_drivers(
 595                 struct extended_perms *xperms,
 596                 struct avtab_node *node)
 597 {
 598         unsigned int i;
 599
 600         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 601                 /* if one or more driver has all permissions allowed */
 602                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 603                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 604         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 605                 /* if allowing permissions within a driver */
 606                 security_xperm_set(xperms->drivers.p,
 607                                         node->datum.u.xperms->driver);
 608         }
 609
 610         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 611         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 612                 xperms->len = 1;
 613 }
 614
 615 /*
 616  * Compute access vectors and extended permissions based on a context
 617  * structure pair for the permissions in a particular class.
 618  */
 619 static void context_struct_compute_av(struct policydb *policydb,
 620                                       struct context *scontext,
 621                                       struct context *tcontext,
 622                                       u16 tclass,
 623                                       struct av_decision *avd,
 624                                       struct extended_perms *xperms)
 625 {
 626         struct constraint_node *constraint;
 627         struct role_allow *ra;
 628         struct avtab_key avkey;
 629         struct avtab_node *node;
 630         struct class_datum *tclass_datum;
 631         struct ebitmap *sattr, *tattr;
 632         struct ebitmap_node *snode, *tnode;
 633         unsigned int i, j;
 634
 635         avd->allowed = 0;
 636         avd->auditallow = 0;
 637         avd->auditdeny = 0xffffffff;
 638         if (xperms) {
 639                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 640                 xperms->len = 0;
 641         }
 642
 643         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 644                 if (printk_ratelimit())
 645                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 646                 return;
 647         }
 648
 649         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 650
 651         /*
 652          * If a specific type enforcement rule was defined for
 653          * this permission check, then use it.
 654          */
 655         avkey.target_class = tclass;
 656         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 657         sattr = flex_array_get(policydb->type_attr_map_array,
 658                                scontext->type - 1);
 659         BUG_ON(!sattr);
 660         tattr = flex_array_get(policydb->type_attr_map_array,
 661                                tcontext->type - 1);
 662         BUG_ON(!tattr);
 663         ebitmap_for_each_positive_bit(sattr, snode, i) {
 664                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 665                         avkey.source_type = i + 1;
 666                         avkey.target_type = j + 1;
 667                         for (node = avtab_search_node(&policydb->te_avtab,
 668                                                       &avkey);
 669                              node;
 670                              node = avtab_search_node_next(node, avkey.specified)) {
 671                                 if (node->key.specified == AVTAB_ALLOWED)
 672                                         avd->allowed |= node->datum.u.data;
 673                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 674                                         avd->auditallow |= node->datum.u.data;
 675                                 else if (node->key.specified == AVTAB_AUDITDENY)
 676                                         avd->auditdeny &= node->datum.u.data;
 677                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 678                                         services_compute_xperms_drivers(xperms, node);
 679                         }
 680
 681                         /* Check conditional av table for additional permissions */
 682                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 683                                         avd, xperms);
 684
 685                 }
 686         }
 687
 688         /*
 689          * Remove any permissions prohibited by a constraint (this includes
 690          * the MLS policy).
 691          */
 692         constraint = tclass_datum->constraints;
 693         while (constraint) {
 694                 if ((constraint->permissions & (avd->allowed)) &&
 695                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 696                                           constraint->expr)) {
 697                         avd->allowed &= ~(constraint->permissions);
 698                 }
 699                 constraint = constraint->next;
 700         }
 701
 702         /*
 703          * If checking process transition permission and the
 704          * role is changing, then check the (current_role, new_role)
 705          * pair.
 706          */
 707         if (tclass == policydb->process_class &&
 708             (avd->allowed & policydb->process_trans_perms) &&
 709             scontext->role != tcontext->role) {
 710                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 711                         if (scontext->role == ra->role &&
 712                             tcontext->role == ra->new_role)
 713                                 break;
 714                 }
 715                 if (!ra)
 716                         avd->allowed &= ~policydb->process_trans_perms;
 717         }
 718
 719         /*
 720          * If the given source and target types have boundary
 721          * constraint, lazy checks have to mask any violated
 722          * permission and notice it to userspace via audit.
 723          */
 724         type_attribute_bounds_av(policydb, scontext, tcontext,
 725                                  tclass, avd);
 726 }
 727
 728 static int security_validtrans_handle_fail(struct selinux_state *state,
 729                                            struct context *ocontext,
 730                                            struct context *ncontext,
 731                                            struct context *tcontext,
 732                                            u16 tclass)
 733 {
 734         struct policydb *p = &state->ss->policydb;
 735         char *o = NULL, *n = NULL, *t = NULL;
 736         u32 olen, nlen, tlen;
 737
 738         if (context_struct_to_string(p, ocontext, &o, &olen))
 739                 goto out;
 740         if (context_struct_to_string(p, ncontext, &n, &nlen))
 741                 goto out;
 742         if (context_struct_to_string(p, tcontext, &t, &tlen))
 743                 goto out;
 744         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 745                   "op=security_validate_transition seresult=denied"
 746                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 747                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 748 out:
 749         kfree(o);
 750         kfree(n);
 751         kfree(t);
 752
 753         if (!enforcing_enabled(state))
 754                 return 0;
 755         return -EPERM;
 756 }
 757
 758 static int security_compute_validatetrans(struct selinux_state *state,
 759                                           u32 oldsid, u32 newsid, u32 tasksid,
 760                                           u16 orig_tclass, bool user)
 761 {
 762         struct policydb *policydb;
 763         struct sidtab *sidtab;
 764         struct context *ocontext;
 765         struct context *ncontext;
 766         struct context *tcontext;
 767         struct class_datum *tclass_datum;
 768         struct constraint_node *constraint;
 769         u16 tclass;
 770         int rc = 0;
 771
 772
 773         if (!state->initialized)
 774                 return 0;
 775
 776         read_lock(&state->ss->policy_rwlock);
 777
 778         policydb = &state->ss->policydb;
 779         sidtab = &state->ss->sidtab;
 780
 781         if (!user)
 782                 tclass = unmap_class(&state->ss->map, orig_tclass);
 783         else
 784                 tclass = orig_tclass;
 785
 786         if (!tclass || tclass > policydb->p_classes.nprim) {
 787                 rc = -EINVAL;
 788                 goto out;
 789         }
 790         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 791
 792         ocontext = sidtab_search(sidtab, oldsid);
 793         if (!ocontext) {
 794                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 795                         __func__, oldsid);
 796                 rc = -EINVAL;
 797                 goto out;
 798         }
 799
 800         ncontext = sidtab_search(sidtab, newsid);
 801         if (!ncontext) {
 802                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 803                         __func__, newsid);
 804                 rc = -EINVAL;
 805                 goto out;
 806         }
 807
 808         tcontext = sidtab_search(sidtab, tasksid);
 809         if (!tcontext) {
 810                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 811                         __func__, tasksid);
 812                 rc = -EINVAL;
 813                 goto out;
 814         }
 815
 816         constraint = tclass_datum->validatetrans;
 817         while (constraint) {
 818                 if (!constraint_expr_eval(policydb, ocontext, ncontext,
 819                                           tcontext, constraint->expr)) {
 820                         if (user)
 821                                 rc = -EPERM;
 822                         else
 823                                 rc = security_validtrans_handle_fail(state,
 824                                                                      ocontext,
 825                                                                      ncontext,
 826                                                                      tcontext,
 827                                                                      tclass);
 828                         goto out;
 829                 }
 830                 constraint = constraint->next;
 831         }
 832
 833 out:
 834         read_unlock(&state->ss->policy_rwlock);
 835         return rc;
 836 }
 837
 838 int security_validate_transition_user(struct selinux_state *state,
 839                                       u32 oldsid, u32 newsid, u32 tasksid,
 840                                       u16 tclass)
 841 {
 842         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 843                                               tclass, true);
 844 }
 845
 846 int security_validate_transition(struct selinux_state *state,
 847                                  u32 oldsid, u32 newsid, u32 tasksid,
 848                                  u16 orig_tclass)
 849 {
 850         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 851                                               orig_tclass, false);
 852 }
 853
 854 /*
 855  * security_bounded_transition - check whether the given
 856  * transition is directed to bounded, or not.
 857  * It returns 0, if @newsid is bounded by @oldsid.
 858  * Otherwise, it returns error code.
 859  *
 860  * @oldsid : current security identifier
 861  * @newsid : destinated security identifier
 862  */
 863 int security_bounded_transition(struct selinux_state *state,
 864                                 u32 old_sid, u32 new_sid)
 865 {
 866         struct policydb *policydb;
 867         struct sidtab *sidtab;
 868         struct context *old_context, *new_context;
 869         struct type_datum *type;
 870         int index;
 871         int rc;
 872
 873         if (!state->initialized)
 874                 return 0;
 875
 876         read_lock(&state->ss->policy_rwlock);
 877
 878         policydb = &state->ss->policydb;
 879         sidtab = &state->ss->sidtab;
 880
 881         rc = -EINVAL;
 882         old_context = sidtab_search(sidtab, old_sid);
 883         if (!old_context) {
 884                 pr_err("SELinux: %s: unrecognized SID %u\n",
 885                        __func__, old_sid);
 886                 goto out;
 887         }
 888
 889         rc = -EINVAL;
 890         new_context = sidtab_search(sidtab, new_sid);
 891         if (!new_context) {
 892                 pr_err("SELinux: %s: unrecognized SID %u\n",
 893                        __func__, new_sid);
 894                 goto out;
 895         }
 896
 897         rc = 0;
 898         /* type/domain unchanged */
 899         if (old_context->type == new_context->type)
 900                 goto out;
 901
 902         index = new_context->type;
 903         while (true) {
 904                 type = flex_array_get_ptr(policydb->type_val_to_struct_array,
 905                                           index - 1);
 906                 BUG_ON(!type);
 907
 908                 /* not bounded anymore */
 909                 rc = -EPERM;
 910                 if (!type->bounds)
 911                         break;
 912
 913                 /* @newsid is bounded by @oldsid */
 914                 rc = 0;
 915                 if (type->bounds == old_context->type)
 916                         break;
 917
 918                 index = type->bounds;
 919         }
 920
 921         if (rc) {
 922                 char *old_name = NULL;
 923                 char *new_name = NULL;
 924                 u32 length;
 925
 926                 if (!context_struct_to_string(policydb, old_context,
 927                                               &old_name, &length) &&
 928                     !context_struct_to_string(policydb, new_context,
 929                                               &new_name, &length)) {
 930                         audit_log(audit_context(),
 931                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 932                                   "op=security_bounded_transition "
 933                                   "seresult=denied "
 934                                   "oldcontext=%s newcontext=%s",
 935                                   old_name, new_name);
 936                 }
 937                 kfree(new_name);
 938                 kfree(old_name);
 939         }
 940 out:
 941         read_unlock(&state->ss->policy_rwlock);
 942
 943         return rc;
 944 }
 945
 946 static void avd_init(struct selinux_state *state, struct av_decision *avd)
 947 {
 948         avd->allowed = 0;
 949         avd->auditallow = 0;
 950         avd->auditdeny = 0xffffffff;
 951         avd->seqno = state->ss->latest_granting;
 952         avd->flags = 0;
 953 }
 954
 955 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 956                                         struct avtab_node *node)
 957 {
 958         unsigned int i;
 959
 960         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 961                 if (xpermd->driver != node->datum.u.xperms->driver)
 962                         return;
 963         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 964                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 965                                         xpermd->driver))
 966                         return;
 967         } else {
 968                 BUG();
 969         }
 970
 971         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 972                 xpermd->used |= XPERMS_ALLOWED;
 973                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 974                         memset(xpermd->allowed->p, 0xff,
 975                                         sizeof(xpermd->allowed->p));
 976                 }
 977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 978                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 979                                 xpermd->allowed->p[i] |=
 980                                         node->datum.u.xperms->perms.p[i];
 981                 }
 982         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 983                 xpermd->used |= XPERMS_AUDITALLOW;
 984                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 985                         memset(xpermd->auditallow->p, 0xff,
 986                                         sizeof(xpermd->auditallow->p));
 987                 }
 988                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 989                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 990                                 xpermd->auditallow->p[i] |=
 991                                         node->datum.u.xperms->perms.p[i];
 992                 }
 993         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 994                 xpermd->used |= XPERMS_DONTAUDIT;
 995                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 996                         memset(xpermd->dontaudit->p, 0xff,
 997                                         sizeof(xpermd->dontaudit->p));
 998                 }
 999                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1000                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1001                                 xpermd->dontaudit->p[i] |=
1002                                         node->datum.u.xperms->perms.p[i];
1003                 }
1004         } else {
1005                 BUG();
1006         }
1007 }
1008
1009 void security_compute_xperms_decision(struct selinux_state *state,
1010                                       u32 ssid,
1011                                       u32 tsid,
1012                                       u16 orig_tclass,
1013                                       u8 driver,
1014                                       struct extended_perms_decision *xpermd)
1015 {
1016         struct policydb *policydb;
1017         struct sidtab *sidtab;
1018         u16 tclass;
1019         struct context *scontext, *tcontext;
1020         struct avtab_key avkey;
1021         struct avtab_node *node;
1022         struct ebitmap *sattr, *tattr;
1023         struct ebitmap_node *snode, *tnode;
1024         unsigned int i, j;
1025
1026         xpermd->driver = driver;
1027         xpermd->used = 0;
1028         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1029         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1030         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1031
1032         read_lock(&state->ss->policy_rwlock);
1033         if (!state->initialized)
1034                 goto allow;
1035
1036         policydb = &state->ss->policydb;
1037         sidtab = &state->ss->sidtab;
1038
1039         scontext = sidtab_search(sidtab, ssid);
1040         if (!scontext) {
1041                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1042                        __func__, ssid);
1043                 goto out;
1044         }
1045
1046         tcontext = sidtab_search(sidtab, tsid);
1047         if (!tcontext) {
1048                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1049                        __func__, tsid);
1050                 goto out;
1051         }
1052
1053         tclass = unmap_class(&state->ss->map, orig_tclass);
1054         if (unlikely(orig_tclass && !tclass)) {
1055                 if (policydb->allow_unknown)
1056                         goto allow;
1057                 goto out;
1058         }
1059
1060
1061         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1062                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1063                 goto out;
1064         }
1065
1066         avkey.target_class = tclass;
1067         avkey.specified = AVTAB_XPERMS;
1068         sattr = flex_array_get(policydb->type_attr_map_array,
1069                                 scontext->type - 1);
1070         BUG_ON(!sattr);
1071         tattr = flex_array_get(policydb->type_attr_map_array,
1072                                 tcontext->type - 1);
1073         BUG_ON(!tattr);
1074         ebitmap_for_each_positive_bit(sattr, snode, i) {
1075                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1076                         avkey.source_type = i + 1;
1077                         avkey.target_type = j + 1;
1078                         for (node = avtab_search_node(&policydb->te_avtab,
1079                                                       &avkey);
1080                              node;
1081                              node = avtab_search_node_next(node, avkey.specified))
1082                                 services_compute_xperms_decision(xpermd, node);
1083
1084                         cond_compute_xperms(&policydb->te_cond_avtab,
1085                                                 &avkey, xpermd);
1086                 }
1087         }
1088 out:
1089         read_unlock(&state->ss->policy_rwlock);
1090         return;
1091 allow:
1092         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1093         goto out;
1094 }
1095
1096 /**
1097  * security_compute_av - Compute access vector decisions.
1098  * @ssid: source security identifier
1099  * @tsid: target security identifier
1100  * @tclass: target security class
1101  * @avd: access vector decisions
1102  * @xperms: extended permissions
1103  *
1104  * Compute a set of access vector decisions based on the
1105  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1106  */
1107 void security_compute_av(struct selinux_state *state,
1108                          u32 ssid,
1109                          u32 tsid,
1110                          u16 orig_tclass,
1111                          struct av_decision *avd,
1112                          struct extended_perms *xperms)
1113 {
1114         struct policydb *policydb;
1115         struct sidtab *sidtab;
1116         u16 tclass;
1117         struct context *scontext = NULL, *tcontext = NULL;
1118
1119         read_lock(&state->ss->policy_rwlock);
1120         avd_init(state, avd);
1121         xperms->len = 0;
1122         if (!state->initialized)
1123                 goto allow;
1124
1125         policydb = &state->ss->policydb;
1126         sidtab = &state->ss->sidtab;
1127
1128         scontext = sidtab_search(sidtab, ssid);
1129         if (!scontext) {
1130                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1131                        __func__, ssid);
1132                 goto out;
1133         }
1134
1135         /* permissive domain? */
1136         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1137                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1138
1139         tcontext = sidtab_search(sidtab, tsid);
1140         if (!tcontext) {
1141                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1142                        __func__, tsid);
1143                 goto out;
1144         }
1145
1146         tclass = unmap_class(&state->ss->map, orig_tclass);
1147         if (unlikely(orig_tclass && !tclass)) {
1148                 if (policydb->allow_unknown)
1149                         goto allow;
1150                 goto out;
1151         }
1152         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1153                                   xperms);
1154         map_decision(&state->ss->map, orig_tclass, avd,
1155                      policydb->allow_unknown);
1156 out:
1157         read_unlock(&state->ss->policy_rwlock);
1158         return;
1159 allow:
1160         avd->allowed = 0xffffffff;
1161         goto out;
1162 }
1163
1164 void security_compute_av_user(struct selinux_state *state,
1165                               u32 ssid,
1166                               u32 tsid,
1167                               u16 tclass,
1168                               struct av_decision *avd)
1169 {
1170         struct policydb *policydb;
1171         struct sidtab *sidtab;
1172         struct context *scontext = NULL, *tcontext = NULL;
1173
1174         read_lock(&state->ss->policy_rwlock);
1175         avd_init(state, avd);
1176         if (!state->initialized)
1177                 goto allow;
1178
1179         policydb = &state->ss->policydb;
1180         sidtab = &state->ss->sidtab;
1181
1182         scontext = sidtab_search(sidtab, ssid);
1183         if (!scontext) {
1184                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1185                        __func__, ssid);
1186                 goto out;
1187         }
1188
1189         /* permissive domain? */
1190         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1191                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1192
1193         tcontext = sidtab_search(sidtab, tsid);
1194         if (!tcontext) {
1195                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1196                        __func__, tsid);
1197                 goto out;
1198         }
1199
1200         if (unlikely(!tclass)) {
1201                 if (policydb->allow_unknown)
1202                         goto allow;
1203                 goto out;
1204         }
1205
1206         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1207                                   NULL);
1208  out:
1209         read_unlock(&state->ss->policy_rwlock);
1210         return;
1211 allow:
1212         avd->allowed = 0xffffffff;
1213         goto out;
1214 }
1215
1216 /*
1217  * Write the security context string representation of
1218  * the context structure `context' into a dynamically
1219  * allocated string of the correct size.  Set `*scontext'
1220  * to point to this string and set `*scontext_len' to
1221  * the length of the string.
1222  */
1223 static int context_struct_to_string(struct policydb *p,
1224                                     struct context *context,
1225                                     char **scontext, u32 *scontext_len)
1226 {
1227         char *scontextp;
1228
1229         if (scontext)
1230                 *scontext = NULL;
1231         *scontext_len = 0;
1232
1233         if (context->len) {
1234                 *scontext_len = context->len;
1235                 if (scontext) {
1236                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1237                         if (!(*scontext))
1238                                 return -ENOMEM;
1239                 }
1240                 return 0;
1241         }
1242
1243         /* Compute the size of the context. */
1244         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1245         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1246         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1247         *scontext_len += mls_compute_context_len(p, context);
1248
1249         if (!scontext)
1250                 return 0;
1251
1252         /* Allocate space for the context; caller must free this space. */
1253         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1254         if (!scontextp)
1255                 return -ENOMEM;
1256         *scontext = scontextp;
1257
1258         /*
1259          * Copy the user name, role name and type name into the context.
1260          */
1261         scontextp += sprintf(scontextp, "%s:%s:%s",
1262                 sym_name(p, SYM_USERS, context->user - 1),
1263                 sym_name(p, SYM_ROLES, context->role - 1),
1264                 sym_name(p, SYM_TYPES, context->type - 1));
1265
1266         mls_sid_to_context(p, context, &scontextp);
1267
1268         *scontextp = 0;
1269
1270         return 0;
1271 }
1272
1273 #include "initial_sid_to_string.h"
1274
1275 const char *security_get_initial_sid_context(u32 sid)
1276 {
1277         if (unlikely(sid > SECINITSID_NUM))
1278                 return NULL;
1279         return initial_sid_to_string[sid];
1280 }
1281
1282 static int security_sid_to_context_core(struct selinux_state *state,
1283                                         u32 sid, char **scontext,
1284                                         u32 *scontext_len, int force)
1285 {
1286         struct policydb *policydb;
1287         struct sidtab *sidtab;
1288         struct context *context;
1289         int rc = 0;
1290
1291         if (scontext)
1292                 *scontext = NULL;
1293         *scontext_len  = 0;
1294
1295         if (!state->initialized) {
1296                 if (sid <= SECINITSID_NUM) {
1297                         char *scontextp;
1298
1299                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1300                         if (!scontext)
1301                                 goto out;
1302                         scontextp = kmemdup(initial_sid_to_string[sid],
1303                                             *scontext_len, GFP_ATOMIC);
1304                         if (!scontextp) {
1305                                 rc = -ENOMEM;
1306                                 goto out;
1307                         }
1308                         *scontext = scontextp;
1309                         goto out;
1310                 }
1311                 pr_err("SELinux: %s:  called before initial "
1312                        "load_policy on unknown SID %d\n", __func__, sid);
1313                 rc = -EINVAL;
1314                 goto out;
1315         }
1316         read_lock(&state->ss->policy_rwlock);
1317         policydb = &state->ss->policydb;
1318         sidtab = &state->ss->sidtab;
1319         if (force)
1320                 context = sidtab_search_force(sidtab, sid);
1321         else
1322                 context = sidtab_search(sidtab, sid);
1323         if (!context) {
1324                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1325                         __func__, sid);
1326                 rc = -EINVAL;
1327                 goto out_unlock;
1328         }
1329         rc = context_struct_to_string(policydb, context, scontext,
1330                                       scontext_len);
1331 out_unlock:
1332         read_unlock(&state->ss->policy_rwlock);
1333 out:
1334         return rc;
1335
1336 }
1337
1338 /**
1339  * security_sid_to_context - Obtain a context for a given SID.
1340  * @sid: security identifier, SID
1341  * @scontext: security context
1342  * @scontext_len: length in bytes
1343  *
1344  * Write the string representation of the context associated with @sid
1345  * into a dynamically allocated string of the correct size.  Set @scontext
1346  * to point to this string and set @scontext_len to the length of the string.
1347  */
1348 int security_sid_to_context(struct selinux_state *state,
1349                             u32 sid, char **scontext, u32 *scontext_len)
1350 {
1351         return security_sid_to_context_core(state, sid, scontext,
1352                                             scontext_len, 0);
1353 }
1354
1355 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1356                                   char **scontext, u32 *scontext_len)
1357 {
1358         return security_sid_to_context_core(state, sid, scontext,
1359                                             scontext_len, 1);
1360 }
1361
1362 /*
1363  * Caveat:  Mutates scontext.
1364  */
1365 static int string_to_context_struct(struct policydb *pol,
1366                                     struct sidtab *sidtabp,
1367                                     char *scontext,
1368                                     u32 scontext_len,
1369                                     struct context *ctx,
1370                                     u32 def_sid)
1371 {
1372         struct role_datum *role;
1373         struct type_datum *typdatum;
1374         struct user_datum *usrdatum;
1375         char *scontextp, *p, oldc;
1376         int rc = 0;
1377
1378         context_init(ctx);
1379
1380         /* Parse the security context. */
1381
1382         rc = -EINVAL;
1383         scontextp = (char *) scontext;
1384
1385         /* Extract the user. */
1386         p = scontextp;
1387         while (*p && *p != ':')
1388                 p++;
1389
1390         if (*p == 0)
1391                 goto out;
1392
1393         *p++ = 0;
1394
1395         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1396         if (!usrdatum)
1397                 goto out;
1398
1399         ctx->user = usrdatum->value;
1400
1401         /* Extract role. */
1402         scontextp = p;
1403         while (*p && *p != ':')
1404                 p++;
1405
1406         if (*p == 0)
1407                 goto out;
1408
1409         *p++ = 0;
1410
1411         role = hashtab_search(pol->p_roles.table, scontextp);
1412         if (!role)
1413                 goto out;
1414         ctx->role = role->value;
1415
1416         /* Extract type. */
1417         scontextp = p;
1418         while (*p && *p != ':')
1419                 p++;
1420         oldc = *p;
1421         *p++ = 0;
1422
1423         typdatum = hashtab_search(pol->p_types.table, scontextp);
1424         if (!typdatum || typdatum->attribute)
1425                 goto out;
1426
1427         ctx->type = typdatum->value;
1428
1429         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1430         if (rc)
1431                 goto out;
1432
1433         rc = -EINVAL;
1434         if ((p - scontext) < scontext_len)
1435                 goto out;
1436
1437         /* Check the validity of the new context. */
1438         if (!policydb_context_isvalid(pol, ctx))
1439                 goto out;
1440         rc = 0;
1441 out:
1442         if (rc)
1443                 context_destroy(ctx);
1444         return rc;
1445 }
1446
1447 static int security_context_to_sid_core(struct selinux_state *state,
1448                                         const char *scontext, u32 scontext_len,
1449                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1450                                         int force)
1451 {
1452         struct policydb *policydb;
1453         struct sidtab *sidtab;
1454         char *scontext2, *str = NULL;
1455         struct context context;
1456         int rc = 0;
1457
1458         /* An empty security context is never valid. */
1459         if (!scontext_len)
1460                 return -EINVAL;
1461
1462         /* Copy the string to allow changes and ensure a NUL terminator */
1463         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1464         if (!scontext2)
1465                 return -ENOMEM;
1466
1467         if (!state->initialized) {
1468                 int i;
1469
1470                 for (i = 1; i < SECINITSID_NUM; i++) {
1471                         if (!strcmp(initial_sid_to_string[i], scontext2)) {
1472                                 *sid = i;
1473                                 goto out;
1474                         }
1475                 }
1476                 *sid = SECINITSID_KERNEL;
1477                 goto out;
1478         }
1479         *sid = SECSID_NULL;
1480
1481         if (force) {
1482                 /* Save another copy for storing in uninterpreted form */
1483                 rc = -ENOMEM;
1484                 str = kstrdup(scontext2, gfp_flags);
1485                 if (!str)
1486                         goto out;
1487         }
1488         read_lock(&state->ss->policy_rwlock);
1489         policydb = &state->ss->policydb;
1490         sidtab = &state->ss->sidtab;
1491         rc = string_to_context_struct(policydb, sidtab, scontext2,
1492                                       scontext_len, &context, def_sid);
1493         if (rc == -EINVAL && force) {
1494                 context.str = str;
1495                 context.len = strlen(str) + 1;
1496                 str = NULL;
1497         } else if (rc)
1498                 goto out_unlock;
1499         rc = sidtab_context_to_sid(sidtab, &context, sid);
1500         context_destroy(&context);
1501 out_unlock:
1502         read_unlock(&state->ss->policy_rwlock);
1503 out:
1504         kfree(scontext2);
1505         kfree(str);
1506         return rc;
1507 }
1508
1509 /**
1510  * security_context_to_sid - Obtain a SID for a given security context.
1511  * @scontext: security context
1512  * @scontext_len: length in bytes
1513  * @sid: security identifier, SID
1514  * @gfp: context for the allocation
1515  *
1516  * Obtains a SID associated with the security context that
1517  * has the string representation specified by @scontext.
1518  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1519  * memory is available, or 0 on success.
1520  */
1521 int security_context_to_sid(struct selinux_state *state,
1522                             const char *scontext, u32 scontext_len, u32 *sid,
1523                             gfp_t gfp)
1524 {
1525         return security_context_to_sid_core(state, scontext, scontext_len,
1526                                             sid, SECSID_NULL, gfp, 0);
1527 }
1528
1529 int security_context_str_to_sid(struct selinux_state *state,
1530                                 const char *scontext, u32 *sid, gfp_t gfp)
1531 {
1532         return security_context_to_sid(state, scontext, strlen(scontext),
1533                                        sid, gfp);
1534 }
1535
1536 /**
1537  * security_context_to_sid_default - Obtain a SID for a given security context,
1538  * falling back to specified default if needed.
1539  *
1540  * @scontext: security context
1541  * @scontext_len: length in bytes
1542  * @sid: security identifier, SID
1543  * @def_sid: default SID to assign on error
1544  *
1545  * Obtains a SID associated with the security context that
1546  * has the string representation specified by @scontext.
1547  * The default SID is passed to the MLS layer to be used to allow
1548  * kernel labeling of the MLS field if the MLS field is not present
1549  * (for upgrading to MLS without full relabel).
1550  * Implicitly forces adding of the context even if it cannot be mapped yet.
1551  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1552  * memory is available, or 0 on success.
1553  */
1554 int security_context_to_sid_default(struct selinux_state *state,
1555                                     const char *scontext, u32 scontext_len,
1556                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1557 {
1558         return security_context_to_sid_core(state, scontext, scontext_len,
1559                                             sid, def_sid, gfp_flags, 1);
1560 }
1561
1562 int security_context_to_sid_force(struct selinux_state *state,
1563                                   const char *scontext, u32 scontext_len,
1564                                   u32 *sid)
1565 {
1566         return security_context_to_sid_core(state, scontext, scontext_len,
1567                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1568 }
1569
1570 static int compute_sid_handle_invalid_context(
1571         struct selinux_state *state,
1572         struct context *scontext,
1573         struct context *tcontext,
1574         u16 tclass,
1575         struct context *newcontext)
1576 {
1577         struct policydb *policydb = &state->ss->policydb;
1578         char *s = NULL, *t = NULL, *n = NULL;
1579         u32 slen, tlen, nlen;
1580
1581         if (context_struct_to_string(policydb, scontext, &s, &slen))
1582                 goto out;
1583         if (context_struct_to_string(policydb, tcontext, &t, &tlen))
1584                 goto out;
1585         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1586                 goto out;
1587         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
1588                   "op=security_compute_sid invalid_context=%s"
1589                   " scontext=%s"
1590                   " tcontext=%s"
1591                   " tclass=%s",
1592                   n, s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1593 out:
1594         kfree(s);
1595         kfree(t);
1596         kfree(n);
1597         if (!enforcing_enabled(state))
1598                 return 0;
1599         return -EACCES;
1600 }
1601
1602 static void filename_compute_type(struct policydb *policydb,
1603                                   struct context *newcontext,
1604                                   u32 stype, u32 ttype, u16 tclass,
1605                                   const char *objname)
1606 {
1607         struct filename_trans ft;
1608         struct filename_trans_datum *otype;
1609
1610         /*
1611          * Most filename trans rules are going to live in specific directories
1612          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1613          * if the ttype does not contain any rules.
1614          */
1615         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1616                 return;
1617
1618         ft.stype = stype;
1619         ft.ttype = ttype;
1620         ft.tclass = tclass;
1621         ft.name = objname;
1622
1623         otype = hashtab_search(policydb->filename_trans, &ft);
1624         if (otype)
1625                 newcontext->type = otype->otype;
1626 }
1627
1628 static int security_compute_sid(struct selinux_state *state,
1629                                 u32 ssid,
1630                                 u32 tsid,
1631                                 u16 orig_tclass,
1632                                 u32 specified,
1633                                 const char *objname,
1634                                 u32 *out_sid,
1635                                 bool kern)
1636 {
1637         struct policydb *policydb;
1638         struct sidtab *sidtab;
1639         struct class_datum *cladatum = NULL;
1640         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1641         struct role_trans *roletr = NULL;
1642         struct avtab_key avkey;
1643         struct avtab_datum *avdatum;
1644         struct avtab_node *node;
1645         u16 tclass;
1646         int rc = 0;
1647         bool sock;
1648
1649         if (!state->initialized) {
1650                 switch (orig_tclass) {
1651                 case SECCLASS_PROCESS: /* kernel value */
1652                         *out_sid = ssid;
1653                         break;
1654                 default:
1655                         *out_sid = tsid;
1656                         break;
1657                 }
1658                 goto out;
1659         }
1660
1661         context_init(&newcontext);
1662
1663         read_lock(&state->ss->policy_rwlock);
1664
1665         if (kern) {
1666                 tclass = unmap_class(&state->ss->map, orig_tclass);
1667                 sock = security_is_socket_class(orig_tclass);
1668         } else {
1669                 tclass = orig_tclass;
1670                 sock = security_is_socket_class(map_class(&state->ss->map,
1671                                                           tclass));
1672         }
1673
1674         policydb = &state->ss->policydb;
1675         sidtab = &state->ss->sidtab;
1676
1677         scontext = sidtab_search(sidtab, ssid);
1678         if (!scontext) {
1679                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1680                        __func__, ssid);
1681                 rc = -EINVAL;
1682                 goto out_unlock;
1683         }
1684         tcontext = sidtab_search(sidtab, tsid);
1685         if (!tcontext) {
1686                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1687                        __func__, tsid);
1688                 rc = -EINVAL;
1689                 goto out_unlock;
1690         }
1691
1692         if (tclass && tclass <= policydb->p_classes.nprim)
1693                 cladatum = policydb->class_val_to_struct[tclass - 1];
1694
1695         /* Set the user identity. */
1696         switch (specified) {
1697         case AVTAB_TRANSITION:
1698         case AVTAB_CHANGE:
1699                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1700                         newcontext.user = tcontext->user;
1701                 } else {
1702                         /* notice this gets both DEFAULT_SOURCE and unset */
1703                         /* Use the process user identity. */
1704                         newcontext.user = scontext->user;
1705                 }
1706                 break;
1707         case AVTAB_MEMBER:
1708                 /* Use the related object owner. */
1709                 newcontext.user = tcontext->user;
1710                 break;
1711         }
1712
1713         /* Set the role to default values. */
1714         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1715                 newcontext.role = scontext->role;
1716         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1717                 newcontext.role = tcontext->role;
1718         } else {
1719                 if ((tclass == policydb->process_class) || (sock == true))
1720                         newcontext.role = scontext->role;
1721                 else
1722                         newcontext.role = OBJECT_R_VAL;
1723         }
1724
1725         /* Set the type to default values. */
1726         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1727                 newcontext.type = scontext->type;
1728         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1729                 newcontext.type = tcontext->type;
1730         } else {
1731                 if ((tclass == policydb->process_class) || (sock == true)) {
1732                         /* Use the type of process. */
1733                         newcontext.type = scontext->type;
1734                 } else {
1735                         /* Use the type of the related object. */
1736                         newcontext.type = tcontext->type;
1737                 }
1738         }
1739
1740         /* Look for a type transition/member/change rule. */
1741         avkey.source_type = scontext->type;
1742         avkey.target_type = tcontext->type;
1743         avkey.target_class = tclass;
1744         avkey.specified = specified;
1745         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1746
1747         /* If no permanent rule, also check for enabled conditional rules */
1748         if (!avdatum) {
1749                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1750                 for (; node; node = avtab_search_node_next(node, specified)) {
1751                         if (node->key.specified & AVTAB_ENABLED) {
1752                                 avdatum = &node->datum;
1753                                 break;
1754                         }
1755                 }
1756         }
1757
1758         if (avdatum) {
1759                 /* Use the type from the type transition/member/change rule. */
1760                 newcontext.type = avdatum->u.data;
1761         }
1762
1763         /* if we have a objname this is a file trans check so check those rules */
1764         if (objname)
1765                 filename_compute_type(policydb, &newcontext, scontext->type,
1766                                       tcontext->type, tclass, objname);
1767
1768         /* Check for class-specific changes. */
1769         if (specified & AVTAB_TRANSITION) {
1770                 /* Look for a role transition rule. */
1771                 for (roletr = policydb->role_tr; roletr;
1772                      roletr = roletr->next) {
1773                         if ((roletr->role == scontext->role) &&
1774                             (roletr->type == tcontext->type) &&
1775                             (roletr->tclass == tclass)) {
1776                                 /* Use the role transition rule. */
1777                                 newcontext.role = roletr->new_role;
1778                                 break;
1779                         }
1780                 }
1781         }
1782
1783         /* Set the MLS attributes.
1784            This is done last because it may allocate memory. */
1785         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1786                              &newcontext, sock);
1787         if (rc)
1788                 goto out_unlock;
1789
1790         /* Check the validity of the context. */
1791         if (!policydb_context_isvalid(policydb, &newcontext)) {
1792                 rc = compute_sid_handle_invalid_context(state, scontext,
1793                                                         tcontext,
1794                                                         tclass,
1795                                                         &newcontext);
1796                 if (rc)
1797                         goto out_unlock;
1798         }
1799         /* Obtain the sid for the context. */
1800         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1801 out_unlock:
1802         read_unlock(&state->ss->policy_rwlock);
1803         context_destroy(&newcontext);
1804 out:
1805         return rc;
1806 }
1807
1808 /**
1809  * security_transition_sid - Compute the SID for a new subject/object.
1810  * @ssid: source security identifier
1811  * @tsid: target security identifier
1812  * @tclass: target security class
1813  * @out_sid: security identifier for new subject/object
1814  *
1815  * Compute a SID to use for labeling a new subject or object in the
1816  * class @tclass based on a SID pair (@ssid, @tsid).
1817  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1818  * if insufficient memory is available, or %0 if the new SID was
1819  * computed successfully.
1820  */
1821 int security_transition_sid(struct selinux_state *state,
1822                             u32 ssid, u32 tsid, u16 tclass,
1823                             const struct qstr *qstr, u32 *out_sid)
1824 {
1825         return security_compute_sid(state, ssid, tsid, tclass,
1826                                     AVTAB_TRANSITION,
1827                                     qstr ? qstr->name : NULL, out_sid, true);
1828 }
1829
1830 int security_transition_sid_user(struct selinux_state *state,
1831                                  u32 ssid, u32 tsid, u16 tclass,
1832                                  const char *objname, u32 *out_sid)
1833 {
1834         return security_compute_sid(state, ssid, tsid, tclass,
1835                                     AVTAB_TRANSITION,
1836                                     objname, out_sid, false);
1837 }
1838
1839 /**
1840  * security_member_sid - Compute the SID for member selection.
1841  * @ssid: source security identifier
1842  * @tsid: target security identifier
1843  * @tclass: target security class
1844  * @out_sid: security identifier for selected member
1845  *
1846  * Compute a SID to use when selecting a member of a polyinstantiated
1847  * object of class @tclass based on a SID pair (@ssid, @tsid).
1848  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1849  * if insufficient memory is available, or %0 if the SID was
1850  * computed successfully.
1851  */
1852 int security_member_sid(struct selinux_state *state,
1853                         u32 ssid,
1854                         u32 tsid,
1855                         u16 tclass,
1856                         u32 *out_sid)
1857 {
1858         return security_compute_sid(state, ssid, tsid, tclass,
1859                                     AVTAB_MEMBER, NULL,
1860                                     out_sid, false);
1861 }
1862
1863 /**
1864  * security_change_sid - Compute the SID for object relabeling.
1865  * @ssid: source security identifier
1866  * @tsid: target security identifier
1867  * @tclass: target security class
1868  * @out_sid: security identifier for selected member
1869  *
1870  * Compute a SID to use for relabeling an object of class @tclass
1871  * based on a SID pair (@ssid, @tsid).
1872  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1873  * if insufficient memory is available, or %0 if the SID was
1874  * computed successfully.
1875  */
1876 int security_change_sid(struct selinux_state *state,
1877                         u32 ssid,
1878                         u32 tsid,
1879                         u16 tclass,
1880                         u32 *out_sid)
1881 {
1882         return security_compute_sid(state,
1883                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1884                                     out_sid, false);
1885 }
1886
1887 /* Clone the SID into the new SID table. */
1888 static int clone_sid(u32 sid,
1889                      struct context *context,
1890                      void *arg)
1891 {
1892         struct sidtab *s = arg;
1893
1894         if (sid > SECINITSID_NUM)
1895                 return sidtab_insert(s, sid, context);
1896         else
1897                 return 0;
1898 }
1899
1900 static inline int convert_context_handle_invalid_context(
1901         struct selinux_state *state,
1902         struct context *context)
1903 {
1904         struct policydb *policydb = &state->ss->policydb;
1905         char *s;
1906         u32 len;
1907
1908         if (enforcing_enabled(state))
1909                 return -EINVAL;
1910
1911         if (!context_struct_to_string(policydb, context, &s, &len)) {
1912                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
1913                         s);
1914                 kfree(s);
1915         }
1916         return 0;
1917 }
1918
1919 struct convert_context_args {
1920         struct selinux_state *state;
1921         struct policydb *oldp;
1922         struct policydb *newp;
1923 };
1924
1925 /*
1926  * Convert the values in the security context
1927  * structure `c' from the values specified
1928  * in the policy `p->oldp' to the values specified
1929  * in the policy `p->newp'.  Verify that the
1930  * context is valid under the new policy.
1931  */
1932 static int convert_context(u32 key,
1933                            struct context *c,
1934                            void *p)
1935 {
1936         struct convert_context_args *args;
1937         struct context oldc;
1938         struct ocontext *oc;
1939         struct mls_range *range;
1940         struct role_datum *role;
1941         struct type_datum *typdatum;
1942         struct user_datum *usrdatum;
1943         char *s;
1944         u32 len;
1945         int rc = 0;
1946
1947         if (key <= SECINITSID_NUM)
1948                 goto out;
1949
1950         args = p;
1951
1952         if (c->str) {
1953                 struct context ctx;
1954
1955                 rc = -ENOMEM;
1956                 s = kstrdup(c->str, GFP_KERNEL);
1957                 if (!s)
1958                         goto out;
1959
1960                 rc = string_to_context_struct(args->newp, NULL, s,
1961                                               c->len, &ctx, SECSID_NULL);
1962                 kfree(s);
1963                 if (!rc) {
1964                         pr_info("SELinux:  Context %s became valid (mapped).\n",
1965                                c->str);
1966                         /* Replace string with mapped representation. */
1967                         kfree(c->str);
1968                         memcpy(c, &ctx, sizeof(*c));
1969                         goto out;
1970                 } else if (rc == -EINVAL) {
1971                         /* Retain string representation for later mapping. */
1972                         rc = 0;
1973                         goto out;
1974                 } else {
1975                         /* Other error condition, e.g. ENOMEM. */
1976                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
1977                                c->str, -rc);
1978                         goto out;
1979                 }
1980         }
1981
1982         rc = context_cpy(&oldc, c);
1983         if (rc)
1984                 goto out;
1985
1986         /* Convert the user. */
1987         rc = -EINVAL;
1988         usrdatum = hashtab_search(args->newp->p_users.table,
1989                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1990         if (!usrdatum)
1991                 goto bad;
1992         c->user = usrdatum->value;
1993
1994         /* Convert the role. */
1995         rc = -EINVAL;
1996         role = hashtab_search(args->newp->p_roles.table,
1997                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1998         if (!role)
1999                 goto bad;
2000         c->role = role->value;
2001
2002         /* Convert the type. */
2003         rc = -EINVAL;
2004         typdatum = hashtab_search(args->newp->p_types.table,
2005                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
2006         if (!typdatum)
2007                 goto bad;
2008         c->type = typdatum->value;
2009
2010         /* Convert the MLS fields if dealing with MLS policies */
2011         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2012                 rc = mls_convert_context(args->oldp, args->newp, c);
2013                 if (rc)
2014                         goto bad;
2015         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
2016                 /*
2017                  * Switching between MLS and non-MLS policy:
2018                  * free any storage used by the MLS fields in the
2019                  * context for all existing entries in the sidtab.
2020                  */
2021                 mls_context_destroy(c);
2022         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2023                 /*
2024                  * Switching between non-MLS and MLS policy:
2025                  * ensure that the MLS fields of the context for all
2026                  * existing entries in the sidtab are filled in with a
2027                  * suitable default value, likely taken from one of the
2028                  * initial SIDs.
2029                  */
2030                 oc = args->newp->ocontexts[OCON_ISID];
2031                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2032                         oc = oc->next;
2033                 rc = -EINVAL;
2034                 if (!oc) {
2035                         pr_err("SELinux:  unable to look up"
2036                                 " the initial SIDs list\n");
2037                         goto bad;
2038                 }
2039                 range = &oc->context[0].range;
2040                 rc = mls_range_set(c, range);
2041                 if (rc)
2042                         goto bad;
2043         }
2044
2045         /* Check the validity of the new context. */
2046         if (!policydb_context_isvalid(args->newp, c)) {
2047                 rc = convert_context_handle_invalid_context(args->state,
2048                                                             &oldc);
2049                 if (rc)
2050                         goto bad;
2051         }
2052
2053         context_destroy(&oldc);
2054
2055         rc = 0;
2056 out:
2057         return rc;
2058 bad:
2059         /* Map old representation to string and save it. */
2060         rc = context_struct_to_string(args->oldp, &oldc, &s, &len);
2061         if (rc)
2062                 return rc;
2063         context_destroy(&oldc);
2064         context_destroy(c);
2065         c->str = s;
2066         c->len = len;
2067         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2068                c->str);
2069         rc = 0;
2070         goto out;
2071 }
2072
2073 static void security_load_policycaps(struct selinux_state *state)
2074 {
2075         struct policydb *p = &state->ss->policydb;
2076         unsigned int i;
2077         struct ebitmap_node *node;
2078
2079         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2080                 state->policycap[i] = ebitmap_get_bit(&p->policycaps, i);
2081
2082         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2083                 pr_info("SELinux:  policy capability %s=%d\n",
2084                         selinux_policycap_names[i],
2085                         ebitmap_get_bit(&p->policycaps, i));
2086
2087         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2088                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2089                         pr_info("SELinux:  unknown policy capability %u\n",
2090                                 i);
2091         }
2092 }
2093
2094 static int security_preserve_bools(struct selinux_state *state,
2095                                    struct policydb *newpolicydb);
2096
2097 /**
2098  * security_load_policy - Load a security policy configuration.
2099  * @data: binary policy data
2100  * @len: length of data in bytes
2101  *
2102  * Load a new set of security policy configuration data,
2103  * validate it and convert the SID table as necessary.
2104  * This function will flush the access vector cache after
2105  * loading the new policy.
2106  */
2107 int security_load_policy(struct selinux_state *state, void *data, size_t len)
2108 {
2109         struct policydb *policydb;
2110         struct sidtab *sidtab;
2111         struct policydb *oldpolicydb, *newpolicydb;
2112         struct sidtab oldsidtab, newsidtab;
2113         struct selinux_mapping *oldmapping;
2114         struct selinux_map newmap;
2115         struct convert_context_args args;
2116         u32 seqno;
2117         int rc = 0;
2118         struct policy_file file = { data, len }, *fp = &file;
2119
2120         oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL);
2121         if (!oldpolicydb) {
2122                 rc = -ENOMEM;
2123                 goto out;
2124         }
2125         newpolicydb = oldpolicydb + 1;
2126
2127         policydb = &state->ss->policydb;
2128         sidtab = &state->ss->sidtab;
2129
2130         if (!state->initialized) {
2131                 rc = policydb_read(policydb, fp);
2132                 if (rc)
2133                         goto out;
2134
2135                 policydb->len = len;
2136                 rc = selinux_set_mapping(policydb, secclass_map,
2137                                          &state->ss->map);
2138                 if (rc) {
2139                         policydb_destroy(policydb);
2140                         goto out;
2141                 }
2142
2143                 rc = policydb_load_isids(policydb, sidtab);
2144                 if (rc) {
2145                         policydb_destroy(policydb);
2146                         goto out;
2147                 }
2148
2149                 security_load_policycaps(state);
2150                 state->initialized = 1;
2151                 seqno = ++state->ss->latest_granting;
2152                 selinux_complete_init();
2153                 avc_ss_reset(state->avc, seqno);
2154                 selnl_notify_policyload(seqno);
2155                 selinux_status_update_policyload(state, seqno);
2156                 selinux_netlbl_cache_invalidate();
2157                 selinux_xfrm_notify_policyload();
2158                 goto out;
2159         }
2160
2161 #if 0
2162         sidtab_hash_eval(sidtab, "sids");
2163 #endif
2164
2165         rc = policydb_read(newpolicydb, fp);
2166         if (rc)
2167                 goto out;
2168
2169         newpolicydb->len = len;
2170         /* If switching between different policy types, log MLS status */
2171         if (policydb->mls_enabled && !newpolicydb->mls_enabled)
2172                 pr_info("SELinux: Disabling MLS support...\n");
2173         else if (!policydb->mls_enabled && newpolicydb->mls_enabled)
2174                 pr_info("SELinux: Enabling MLS support...\n");
2175
2176         rc = policydb_load_isids(newpolicydb, &newsidtab);
2177         if (rc) {
2178                 pr_err("SELinux:  unable to load the initial SIDs\n");
2179                 policydb_destroy(newpolicydb);
2180                 goto out;
2181         }
2182
2183         rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap);
2184         if (rc)
2185                 goto err;
2186
2187         rc = security_preserve_bools(state, newpolicydb);
2188         if (rc) {
2189                 pr_err("SELinux:  unable to preserve booleans\n");
2190                 goto err;
2191         }
2192
2193         /* Clone the SID table. */
2194         sidtab_shutdown(sidtab);
2195
2196         rc = sidtab_map(sidtab, clone_sid, &newsidtab);
2197         if (rc)
2198                 goto err;
2199
2200         /*
2201          * Convert the internal representations of contexts
2202          * in the new SID table.
2203          */
2204         args.state = state;
2205         args.oldp = policydb;
2206         args.newp = newpolicydb;
2207         rc = sidtab_map(&newsidtab, convert_context, &args);
2208         if (rc) {
2209                 pr_err("SELinux:  unable to convert the internal"
2210                         " representation of contexts in the new SID"
2211                         " table\n");
2212                 goto err;
2213         }
2214
2215         /* Save the old policydb and SID table to free later. */
2216         memcpy(oldpolicydb, policydb, sizeof(*policydb));
2217         sidtab_set(&oldsidtab, sidtab);
2218
2219         /* Install the new policydb and SID table. */
2220         write_lock_irq(&state->ss->policy_rwlock);
2221         memcpy(policydb, newpolicydb, sizeof(*policydb));
2222         sidtab_set(sidtab, &newsidtab);
2223         security_load_policycaps(state);
2224         oldmapping = state->ss->map.mapping;
2225         state->ss->map.mapping = newmap.mapping;
2226         state->ss->map.size = newmap.size;
2227         seqno = ++state->ss->latest_granting;
2228         write_unlock_irq(&state->ss->policy_rwlock);
2229
2230         /* Free the old policydb and SID table. */
2231         policydb_destroy(oldpolicydb);
2232         sidtab_destroy(&oldsidtab);
2233         kfree(oldmapping);
2234
2235         avc_ss_reset(state->avc, seqno);
2236         selnl_notify_policyload(seqno);
2237         selinux_status_update_policyload(state, seqno);
2238         selinux_netlbl_cache_invalidate();
2239         selinux_xfrm_notify_policyload();
2240
2241         rc = 0;
2242         goto out;
2243
2244 err:
2245         kfree(newmap.mapping);
2246         sidtab_destroy(&newsidtab);
2247         policydb_destroy(newpolicydb);
2248
2249 out:
2250         kfree(oldpolicydb);
2251         return rc;
2252 }
2253
2254 size_t security_policydb_len(struct selinux_state *state)
2255 {
2256         struct policydb *p = &state->ss->policydb;
2257         size_t len;
2258
2259         read_lock(&state->ss->policy_rwlock);
2260         len = p->len;
2261         read_unlock(&state->ss->policy_rwlock);
2262
2263         return len;
2264 }
2265
2266 /**
2267  * security_port_sid - Obtain the SID for a port.
2268  * @protocol: protocol number
2269  * @port: port number
2270  * @out_sid: security identifier
2271  */
2272 int security_port_sid(struct selinux_state *state,
2273                       u8 protocol, u16 port, u32 *out_sid)
2274 {
2275         struct policydb *policydb;
2276         struct sidtab *sidtab;
2277         struct ocontext *c;
2278         int rc = 0;
2279
2280         read_lock(&state->ss->policy_rwlock);
2281
2282         policydb = &state->ss->policydb;
2283         sidtab = &state->ss->sidtab;
2284
2285         c = policydb->ocontexts[OCON_PORT];
2286         while (c) {
2287                 if (c->u.port.protocol == protocol &&
2288                     c->u.port.low_port <= port &&
2289                     c->u.port.high_port >= port)
2290                         break;
2291                 c = c->next;
2292         }
2293
2294         if (c) {
2295                 if (!c->sid[0]) {
2296                         rc = sidtab_context_to_sid(sidtab,
2297                                                    &c->context[0],
2298                                                    &c->sid[0]);
2299                         if (rc)
2300                                 goto out;
2301                 }
2302                 *out_sid = c->sid[0];
2303         } else {
2304                 *out_sid = SECINITSID_PORT;
2305         }
2306
2307 out:
2308         read_unlock(&state->ss->policy_rwlock);
2309         return rc;
2310 }
2311
2312 /**
2313  * security_pkey_sid - Obtain the SID for a pkey.
2314  * @subnet_prefix: Subnet Prefix
2315  * @pkey_num: pkey number
2316  * @out_sid: security identifier
2317  */
2318 int security_ib_pkey_sid(struct selinux_state *state,
2319                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2320 {
2321         struct policydb *policydb;
2322         struct sidtab *sidtab;
2323         struct ocontext *c;
2324         int rc = 0;
2325
2326         read_lock(&state->ss->policy_rwlock);
2327
2328         policydb = &state->ss->policydb;
2329         sidtab = &state->ss->sidtab;
2330
2331         c = policydb->ocontexts[OCON_IBPKEY];
2332         while (c) {
2333                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2334                     c->u.ibpkey.high_pkey >= pkey_num &&
2335                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2336                         break;
2337
2338                 c = c->next;
2339         }
2340
2341         if (c) {
2342                 if (!c->sid[0]) {
2343                         rc = sidtab_context_to_sid(sidtab,
2344                                                    &c->context[0],
2345                                                    &c->sid[0]);
2346                         if (rc)
2347                                 goto out;
2348                 }
2349                 *out_sid = c->sid[0];
2350         } else
2351                 *out_sid = SECINITSID_UNLABELED;
2352
2353 out:
2354         read_unlock(&state->ss->policy_rwlock);
2355         return rc;
2356 }
2357
2358 /**
2359  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2360  * @dev_name: device name
2361  * @port: port number
2362  * @out_sid: security identifier
2363  */
2364 int security_ib_endport_sid(struct selinux_state *state,
2365                             const char *dev_name, u8 port_num, u32 *out_sid)
2366 {
2367         struct policydb *policydb;
2368         struct sidtab *sidtab;
2369         struct ocontext *c;
2370         int rc = 0;
2371
2372         read_lock(&state->ss->policy_rwlock);
2373
2374         policydb = &state->ss->policydb;
2375         sidtab = &state->ss->sidtab;
2376
2377         c = policydb->ocontexts[OCON_IBENDPORT];
2378         while (c) {
2379                 if (c->u.ibendport.port == port_num &&
2380                     !strncmp(c->u.ibendport.dev_name,
2381                              dev_name,
2382                              IB_DEVICE_NAME_MAX))
2383                         break;
2384
2385                 c = c->next;
2386         }
2387
2388         if (c) {
2389                 if (!c->sid[0]) {
2390                         rc = sidtab_context_to_sid(sidtab,
2391                                                    &c->context[0],
2392                                                    &c->sid[0]);
2393                         if (rc)
2394                                 goto out;
2395                 }
2396                 *out_sid = c->sid[0];
2397         } else
2398                 *out_sid = SECINITSID_UNLABELED;
2399
2400 out:
2401         read_unlock(&state->ss->policy_rwlock);
2402         return rc;
2403 }
2404
2405 /**
2406  * security_netif_sid - Obtain the SID for a network interface.
2407  * @name: interface name
2408  * @if_sid: interface SID
2409  */
2410 int security_netif_sid(struct selinux_state *state,
2411                        char *name, u32 *if_sid)
2412 {
2413         struct policydb *policydb;
2414         struct sidtab *sidtab;
2415         int rc = 0;
2416         struct ocontext *c;
2417
2418         read_lock(&state->ss->policy_rwlock);
2419
2420         policydb = &state->ss->policydb;
2421         sidtab = &state->ss->sidtab;
2422
2423         c = policydb->ocontexts[OCON_NETIF];
2424         while (c) {
2425                 if (strcmp(name, c->u.name) == 0)
2426                         break;
2427                 c = c->next;
2428         }
2429
2430         if (c) {
2431                 if (!c->sid[0] || !c->sid[1]) {
2432                         rc = sidtab_context_to_sid(sidtab,
2433                                                   &c->context[0],
2434                                                   &c->sid[0]);
2435                         if (rc)
2436                                 goto out;
2437                         rc = sidtab_context_to_sid(sidtab,
2438                                                    &c->context[1],
2439                                                    &c->sid[1]);
2440                         if (rc)
2441                                 goto out;
2442                 }
2443                 *if_sid = c->sid[0];
2444         } else
2445                 *if_sid = SECINITSID_NETIF;
2446
2447 out:
2448         read_unlock(&state->ss->policy_rwlock);
2449         return rc;
2450 }
2451
2452 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2453 {
2454         int i, fail = 0;
2455
2456         for (i = 0; i < 4; i++)
2457                 if (addr[i] != (input[i] & mask[i])) {
2458                         fail = 1;
2459                         break;
2460                 }
2461
2462         return !fail;
2463 }
2464
2465 /**
2466  * security_node_sid - Obtain the SID for a node (host).
2467  * @domain: communication domain aka address family
2468  * @addrp: address
2469  * @addrlen: address length in bytes
2470  * @out_sid: security identifier
2471  */
2472 int security_node_sid(struct selinux_state *state,
2473                       u16 domain,
2474                       void *addrp,
2475                       u32 addrlen,
2476                       u32 *out_sid)
2477 {
2478         struct policydb *policydb;
2479         struct sidtab *sidtab;
2480         int rc;
2481         struct ocontext *c;
2482
2483         read_lock(&state->ss->policy_rwlock);
2484
2485         policydb = &state->ss->policydb;
2486         sidtab = &state->ss->sidtab;
2487
2488         switch (domain) {
2489         case AF_INET: {
2490                 u32 addr;
2491
2492                 rc = -EINVAL;
2493                 if (addrlen != sizeof(u32))
2494                         goto out;
2495
2496                 addr = *((u32 *)addrp);
2497
2498                 c = policydb->ocontexts[OCON_NODE];
2499                 while (c) {
2500                         if (c->u.node.addr == (addr & c->u.node.mask))
2501                                 break;
2502                         c = c->next;
2503                 }
2504                 break;
2505         }
2506
2507         case AF_INET6:
2508                 rc = -EINVAL;
2509                 if (addrlen != sizeof(u64) * 2)
2510                         goto out;
2511                 c = policydb->ocontexts[OCON_NODE6];
2512                 while (c) {
2513                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2514                                                 c->u.node6.mask))
2515                                 break;
2516                         c = c->next;
2517                 }
2518                 break;
2519
2520         default:
2521                 rc = 0;
2522                 *out_sid = SECINITSID_NODE;
2523                 goto out;
2524         }
2525
2526         if (c) {
2527                 if (!c->sid[0]) {
2528                         rc = sidtab_context_to_sid(sidtab,
2529                                                    &c->context[0],
2530                                                    &c->sid[0]);
2531                         if (rc)
2532                                 goto out;
2533                 }
2534                 *out_sid = c->sid[0];
2535         } else {
2536                 *out_sid = SECINITSID_NODE;
2537         }
2538
2539         rc = 0;
2540 out:
2541         read_unlock(&state->ss->policy_rwlock);
2542         return rc;
2543 }
2544
2545 #define SIDS_NEL 25
2546
2547 /**
2548  * security_get_user_sids - Obtain reachable SIDs for a user.
2549  * @fromsid: starting SID
2550  * @username: username
2551  * @sids: array of reachable SIDs for user
2552  * @nel: number of elements in @sids
2553  *
2554  * Generate the set of SIDs for legal security contexts
2555  * for a given user that can be reached by @fromsid.
2556  * Set *@sids to point to a dynamically allocated
2557  * array containing the set of SIDs.  Set *@nel to the
2558  * number of elements in the array.
2559  */
2560
2561 int security_get_user_sids(struct selinux_state *state,
2562                            u32 fromsid,
2563                            char *username,
2564                            u32 **sids,
2565                            u32 *nel)
2566 {
2567         struct policydb *policydb;
2568         struct sidtab *sidtab;
2569         struct context *fromcon, usercon;
2570         u32 *mysids = NULL, *mysids2, sid;
2571         u32 mynel = 0, maxnel = SIDS_NEL;
2572         struct user_datum *user;
2573         struct role_datum *role;
2574         struct ebitmap_node *rnode, *tnode;
2575         int rc = 0, i, j;
2576
2577         *sids = NULL;
2578         *nel = 0;
2579
2580         if (!state->initialized)
2581                 goto out;
2582
2583         read_lock(&state->ss->policy_rwlock);
2584
2585         policydb = &state->ss->policydb;
2586         sidtab = &state->ss->sidtab;
2587
2588         context_init(&usercon);
2589
2590         rc = -EINVAL;
2591         fromcon = sidtab_search(sidtab, fromsid);
2592         if (!fromcon)
2593                 goto out_unlock;
2594
2595         rc = -EINVAL;
2596         user = hashtab_search(policydb->p_users.table, username);
2597         if (!user)
2598                 goto out_unlock;
2599
2600         usercon.user = user->value;
2601
2602         rc = -ENOMEM;
2603         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2604         if (!mysids)
2605                 goto out_unlock;
2606
2607         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2608                 role = policydb->role_val_to_struct[i];
2609                 usercon.role = i + 1;
2610                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2611                         usercon.type = j + 1;
2612
2613                         if (mls_setup_user_range(policydb, fromcon, user,
2614                                                  &usercon))
2615                                 continue;
2616
2617                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2618                         if (rc)
2619                                 goto out_unlock;
2620                         if (mynel < maxnel) {
2621                                 mysids[mynel++] = sid;
2622                         } else {
2623                                 rc = -ENOMEM;
2624                                 maxnel += SIDS_NEL;
2625                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2626                                 if (!mysids2)
2627                                         goto out_unlock;
2628                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2629                                 kfree(mysids);
2630                                 mysids = mysids2;
2631                                 mysids[mynel++] = sid;
2632                         }
2633                 }
2634         }
2635         rc = 0;
2636 out_unlock:
2637         read_unlock(&state->ss->policy_rwlock);
2638         if (rc || !mynel) {
2639                 kfree(mysids);
2640                 goto out;
2641         }
2642
2643         rc = -ENOMEM;
2644         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2645         if (!mysids2) {
2646                 kfree(mysids);
2647                 goto out;
2648         }
2649         for (i = 0, j = 0; i < mynel; i++) {
2650                 struct av_decision dummy_avd;
2651                 rc = avc_has_perm_noaudit(state,
2652                                           fromsid, mysids[i],
2653                                           SECCLASS_PROCESS, /* kernel value */
2654                                           PROCESS__TRANSITION, AVC_STRICT,
2655                                           &dummy_avd);
2656                 if (!rc)
2657                         mysids2[j++] = mysids[i];
2658                 cond_resched();
2659         }
2660         rc = 0;
2661         kfree(mysids);
2662         *sids = mysids2;
2663         *nel = j;
2664 out:
2665         return rc;
2666 }
2667
2668 /**
2669  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2670  * @fstype: filesystem type
2671  * @path: path from root of mount
2672  * @sclass: file security class
2673  * @sid: SID for path
2674  *
2675  * Obtain a SID to use for a file in a filesystem that
2676  * cannot support xattr or use a fixed labeling behavior like
2677  * transition SIDs or task SIDs.
2678  *
2679  * The caller must acquire the policy_rwlock before calling this function.
2680  */
2681 static inline int __security_genfs_sid(struct selinux_state *state,
2682                                        const char *fstype,
2683                                        char *path,
2684                                        u16 orig_sclass,
2685                                        u32 *sid)
2686 {
2687         struct policydb *policydb = &state->ss->policydb;
2688         struct sidtab *sidtab = &state->ss->sidtab;
2689         int len;
2690         u16 sclass;
2691         struct genfs *genfs;
2692         struct ocontext *c;
2693         int rc, cmp = 0;
2694
2695         while (path[0] == '/' && path[1] == '/')
2696                 path++;
2697
2698         sclass = unmap_class(&state->ss->map, orig_sclass);
2699         *sid = SECINITSID_UNLABELED;
2700
2701         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2702                 cmp = strcmp(fstype, genfs->fstype);
2703                 if (cmp <= 0)
2704                         break;
2705         }
2706
2707         rc = -ENOENT;
2708         if (!genfs || cmp)
2709                 goto out;
2710
2711         for (c = genfs->head; c; c = c->next) {
2712                 len = strlen(c->u.name);
2713                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2714                     (strncmp(c->u.name, path, len) == 0))
2715                         break;
2716         }
2717
2718         rc = -ENOENT;
2719         if (!c)
2720                 goto out;
2721
2722         if (!c->sid[0]) {
2723                 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
2724                 if (rc)
2725                         goto out;
2726         }
2727
2728         *sid = c->sid[0];
2729         rc = 0;
2730 out:
2731         return rc;
2732 }
2733
2734 /**
2735  * security_genfs_sid - Obtain a SID for a file in a filesystem
2736  * @fstype: filesystem type
2737  * @path: path from root of mount
2738  * @sclass: file security class
2739  * @sid: SID for path
2740  *
2741  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2742  * it afterward.
2743  */
2744 int security_genfs_sid(struct selinux_state *state,
2745                        const char *fstype,
2746                        char *path,
2747                        u16 orig_sclass,
2748                        u32 *sid)
2749 {
2750         int retval;
2751
2752         read_lock(&state->ss->policy_rwlock);
2753         retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid);
2754         read_unlock(&state->ss->policy_rwlock);
2755         return retval;
2756 }
2757
2758 /**
2759  * security_fs_use - Determine how to handle labeling for a filesystem.
2760  * @sb: superblock in question
2761  */
2762 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2763 {
2764         struct policydb *policydb;
2765         struct sidtab *sidtab;
2766         int rc = 0;
2767         struct ocontext *c;
2768         struct superblock_security_struct *sbsec = sb->s_security;
2769         const char *fstype = sb->s_type->name;
2770
2771         read_lock(&state->ss->policy_rwlock);
2772
2773         policydb = &state->ss->policydb;
2774         sidtab = &state->ss->sidtab;
2775
2776         c = policydb->ocontexts[OCON_FSUSE];
2777         while (c) {
2778                 if (strcmp(fstype, c->u.name) == 0)
2779                         break;
2780                 c = c->next;
2781         }
2782
2783         if (c) {
2784                 sbsec->behavior = c->v.behavior;
2785                 if (!c->sid[0]) {
2786                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2787                                                    &c->sid[0]);
2788                         if (rc)
2789                                 goto out;
2790                 }
2791                 sbsec->sid = c->sid[0];
2792         } else {
2793                 rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR,
2794                                           &sbsec->sid);
2795                 if (rc) {
2796                         sbsec->behavior = SECURITY_FS_USE_NONE;
2797                         rc = 0;
2798                 } else {
2799                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2800                 }
2801         }
2802
2803 out:
2804         read_unlock(&state->ss->policy_rwlock);
2805         return rc;
2806 }
2807
2808 int security_get_bools(struct selinux_state *state,
2809                        int *len, char ***names, int **values)
2810 {
2811         struct policydb *policydb;
2812         int i, rc;
2813
2814         if (!state->initialized) {
2815                 *len = 0;
2816                 *names = NULL;
2817                 *values = NULL;
2818                 return 0;
2819         }
2820
2821         read_lock(&state->ss->policy_rwlock);
2822
2823         policydb = &state->ss->policydb;
2824
2825         *names = NULL;
2826         *values = NULL;
2827
2828         rc = 0;
2829         *len = policydb->p_bools.nprim;
2830         if (!*len)
2831                 goto out;
2832
2833         rc = -ENOMEM;
2834         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2835         if (!*names)
2836                 goto err;
2837
2838         rc = -ENOMEM;
2839         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2840         if (!*values)
2841                 goto err;
2842
2843         for (i = 0; i < *len; i++) {
2844                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
2845
2846                 rc = -ENOMEM;
2847                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
2848                                       GFP_ATOMIC);
2849                 if (!(*names)[i])
2850                         goto err;
2851         }
2852         rc = 0;
2853 out:
2854         read_unlock(&state->ss->policy_rwlock);
2855         return rc;
2856 err:
2857         if (*names) {
2858                 for (i = 0; i < *len; i++)
2859                         kfree((*names)[i]);
2860                 kfree(*names);
2861         }
2862         kfree(*values);
2863         *len = 0;
2864         *names = NULL;
2865         *values = NULL;
2866         goto out;
2867 }
2868
2869
2870 int security_set_bools(struct selinux_state *state, int len, int *values)
2871 {
2872         struct policydb *policydb;
2873         int i, rc;
2874         int lenp, seqno = 0;
2875         struct cond_node *cur;
2876
2877         write_lock_irq(&state->ss->policy_rwlock);
2878
2879         policydb = &state->ss->policydb;
2880
2881         rc = -EFAULT;
2882         lenp = policydb->p_bools.nprim;
2883         if (len != lenp)
2884                 goto out;
2885
2886         for (i = 0; i < len; i++) {
2887                 if (!!values[i] != policydb->bool_val_to_struct[i]->state) {
2888                         audit_log(audit_context(), GFP_ATOMIC,
2889                                 AUDIT_MAC_CONFIG_CHANGE,
2890                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2891                                 sym_name(policydb, SYM_BOOLS, i),
2892                                 !!values[i],
2893                                 policydb->bool_val_to_struct[i]->state,
2894                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2895                                 audit_get_sessionid(current));
2896                 }
2897                 if (values[i])
2898                         policydb->bool_val_to_struct[i]->state = 1;
2899                 else
2900                         policydb->bool_val_to_struct[i]->state = 0;
2901         }
2902
2903         for (cur = policydb->cond_list; cur; cur = cur->next) {
2904                 rc = evaluate_cond_node(policydb, cur);
2905                 if (rc)
2906                         goto out;
2907         }
2908
2909         seqno = ++state->ss->latest_granting;
2910         rc = 0;
2911 out:
2912         write_unlock_irq(&state->ss->policy_rwlock);
2913         if (!rc) {
2914                 avc_ss_reset(state->avc, seqno);
2915                 selnl_notify_policyload(seqno);
2916                 selinux_status_update_policyload(state, seqno);
2917                 selinux_xfrm_notify_policyload();
2918         }
2919         return rc;
2920 }
2921
2922 int security_get_bool_value(struct selinux_state *state,
2923                             int index)
2924 {
2925         struct policydb *policydb;
2926         int rc;
2927         int len;
2928
2929         read_lock(&state->ss->policy_rwlock);
2930
2931         policydb = &state->ss->policydb;
2932
2933         rc = -EFAULT;
2934         len = policydb->p_bools.nprim;
2935         if (index >= len)
2936                 goto out;
2937
2938         rc = policydb->bool_val_to_struct[index]->state;
2939 out:
2940         read_unlock(&state->ss->policy_rwlock);
2941         return rc;
2942 }
2943
2944 static int security_preserve_bools(struct selinux_state *state,
2945                                    struct policydb *policydb)
2946 {
2947         int rc, nbools = 0, *bvalues = NULL, i;
2948         char **bnames = NULL;
2949         struct cond_bool_datum *booldatum;
2950         struct cond_node *cur;
2951
2952         rc = security_get_bools(state, &nbools, &bnames, &bvalues);
2953         if (rc)
2954                 goto out;
2955         for (i = 0; i < nbools; i++) {
2956                 booldatum = hashtab_search(policydb->p_bools.table, bnames[i]);
2957                 if (booldatum)
2958                         booldatum->state = bvalues[i];
2959         }
2960         for (cur = policydb->cond_list; cur; cur = cur->next) {
2961                 rc = evaluate_cond_node(policydb, cur);
2962                 if (rc)
2963                         goto out;
2964         }
2965
2966 out:
2967         if (bnames) {
2968                 for (i = 0; i < nbools; i++)
2969                         kfree(bnames[i]);
2970         }
2971         kfree(bnames);
2972         kfree(bvalues);
2973         return rc;
2974 }
2975
2976 /*
2977  * security_sid_mls_copy() - computes a new sid based on the given
2978  * sid and the mls portion of mls_sid.
2979  */
2980 int security_sid_mls_copy(struct selinux_state *state,
2981                           u32 sid, u32 mls_sid, u32 *new_sid)
2982 {
2983         struct policydb *policydb = &state->ss->policydb;
2984         struct sidtab *sidtab = &state->ss->sidtab;
2985         struct context *context1;
2986         struct context *context2;
2987         struct context newcon;
2988         char *s;
2989         u32 len;
2990         int rc;
2991
2992         rc = 0;
2993         if (!state->initialized || !policydb->mls_enabled) {
2994                 *new_sid = sid;
2995                 goto out;
2996         }
2997
2998         context_init(&newcon);
2999
3000         read_lock(&state->ss->policy_rwlock);
3001
3002         rc = -EINVAL;
3003         context1 = sidtab_search(sidtab, sid);
3004         if (!context1) {
3005                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3006                         __func__, sid);
3007                 goto out_unlock;
3008         }
3009
3010         rc = -EINVAL;
3011         context2 = sidtab_search(sidtab, mls_sid);
3012         if (!context2) {
3013                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3014                         __func__, mls_sid);
3015                 goto out_unlock;
3016         }
3017
3018         newcon.user = context1->user;
3019         newcon.role = context1->role;
3020         newcon.type = context1->type;
3021         rc = mls_context_cpy(&newcon, context2);
3022         if (rc)
3023                 goto out_unlock;
3024
3025         /* Check the validity of the new context. */
3026         if (!policydb_context_isvalid(policydb, &newcon)) {
3027                 rc = convert_context_handle_invalid_context(state, &newcon);
3028                 if (rc) {
3029                         if (!context_struct_to_string(policydb, &newcon, &s,
3030                                                       &len)) {
3031                                 audit_log(audit_context(),
3032                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
3033                                           "op=security_sid_mls_copy "
3034                                           "invalid_context=%s", s);
3035                                 kfree(s);
3036                         }
3037                         goto out_unlock;
3038                 }
3039         }
3040
3041         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3042 out_unlock:
3043         read_unlock(&state->ss->policy_rwlock);
3044         context_destroy(&newcon);
3045 out:
3046         return rc;
3047 }
3048
3049 /**
3050  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3051  * @nlbl_sid: NetLabel SID
3052  * @nlbl_type: NetLabel labeling protocol type
3053  * @xfrm_sid: XFRM SID
3054  *
3055  * Description:
3056  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3057  * resolved into a single SID it is returned via @peer_sid and the function
3058  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3059  * returns a negative value.  A table summarizing the behavior is below:
3060  *
3061  *                                 | function return |      @sid
3062  *   ------------------------------+-----------------+-----------------
3063  *   no peer labels                |        0        |    SECSID_NULL
3064  *   single peer label             |        0        |    <peer_label>
3065  *   multiple, consistent labels   |        0        |    <peer_label>
3066  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3067  *
3068  */
3069 int security_net_peersid_resolve(struct selinux_state *state,
3070                                  u32 nlbl_sid, u32 nlbl_type,
3071                                  u32 xfrm_sid,
3072                                  u32 *peer_sid)
3073 {
3074         struct policydb *policydb = &state->ss->policydb;
3075         struct sidtab *sidtab = &state->ss->sidtab;
3076         int rc;
3077         struct context *nlbl_ctx;
3078         struct context *xfrm_ctx;
3079
3080         *peer_sid = SECSID_NULL;
3081
3082         /* handle the common (which also happens to be the set of easy) cases
3083          * right away, these two if statements catch everything involving a
3084          * single or absent peer SID/label */
3085         if (xfrm_sid == SECSID_NULL) {
3086                 *peer_sid = nlbl_sid;
3087                 return 0;
3088         }
3089         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3090          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3091          * is present */
3092         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3093                 *peer_sid = xfrm_sid;
3094                 return 0;
3095         }
3096
3097         /*
3098          * We don't need to check initialized here since the only way both
3099          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3100          * security server was initialized and state->initialized was true.
3101          */
3102         if (!policydb->mls_enabled)
3103                 return 0;
3104
3105         read_lock(&state->ss->policy_rwlock);
3106
3107         rc = -EINVAL;
3108         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3109         if (!nlbl_ctx) {
3110                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3111                        __func__, nlbl_sid);
3112                 goto out;
3113         }
3114         rc = -EINVAL;
3115         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3116         if (!xfrm_ctx) {
3117                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3118                        __func__, xfrm_sid);
3119                 goto out;
3120         }
3121         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3122         if (rc)
3123                 goto out;
3124
3125         /* at present NetLabel SIDs/labels really only carry MLS
3126          * information so if the MLS portion of the NetLabel SID
3127          * matches the MLS portion of the labeled XFRM SID/label
3128          * then pass along the XFRM SID as it is the most
3129          * expressive */
3130         *peer_sid = xfrm_sid;
3131 out:
3132         read_unlock(&state->ss->policy_rwlock);
3133         return rc;
3134 }
3135
3136 static int get_classes_callback(void *k, void *d, void *args)
3137 {
3138         struct class_datum *datum = d;
3139         char *name = k, **classes = args;
3140         int value = datum->value - 1;
3141
3142         classes[value] = kstrdup(name, GFP_ATOMIC);
3143         if (!classes[value])
3144                 return -ENOMEM;
3145
3146         return 0;
3147 }
3148
3149 int security_get_classes(struct selinux_state *state,
3150                          char ***classes, int *nclasses)
3151 {
3152         struct policydb *policydb = &state->ss->policydb;
3153         int rc;
3154
3155         if (!state->initialized) {
3156                 *nclasses = 0;
3157                 *classes = NULL;
3158                 return 0;
3159         }
3160
3161         read_lock(&state->ss->policy_rwlock);
3162
3163         rc = -ENOMEM;
3164         *nclasses = policydb->p_classes.nprim;
3165         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3166         if (!*classes)
3167                 goto out;
3168
3169         rc = hashtab_map(policydb->p_classes.table, get_classes_callback,
3170                         *classes);
3171         if (rc) {
3172                 int i;
3173                 for (i = 0; i < *nclasses; i++)
3174                         kfree((*classes)[i]);
3175                 kfree(*classes);
3176         }
3177
3178 out:
3179         read_unlock(&state->ss->policy_rwlock);
3180         return rc;
3181 }
3182
3183 static int get_permissions_callback(void *k, void *d, void *args)
3184 {
3185         struct perm_datum *datum = d;
3186         char *name = k, **perms = args;
3187         int value = datum->value - 1;
3188
3189         perms[value] = kstrdup(name, GFP_ATOMIC);
3190         if (!perms[value])
3191                 return -ENOMEM;
3192
3193         return 0;
3194 }
3195
3196 int security_get_permissions(struct selinux_state *state,
3197                              char *class, char ***perms, int *nperms)
3198 {
3199         struct policydb *policydb = &state->ss->policydb;
3200         int rc, i;
3201         struct class_datum *match;
3202
3203         read_lock(&state->ss->policy_rwlock);
3204
3205         rc = -EINVAL;
3206         match = hashtab_search(policydb->p_classes.table, class);
3207         if (!match) {
3208                 pr_err("SELinux: %s:  unrecognized class %s\n",
3209                         __func__, class);
3210                 goto out;
3211         }
3212
3213         rc = -ENOMEM;
3214         *nperms = match->permissions.nprim;
3215         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3216         if (!*perms)
3217                 goto out;
3218
3219         if (match->comdatum) {
3220                 rc = hashtab_map(match->comdatum->permissions.table,
3221                                 get_permissions_callback, *perms);
3222                 if (rc)
3223                         goto err;
3224         }
3225
3226         rc = hashtab_map(match->permissions.table, get_permissions_callback,
3227                         *perms);
3228         if (rc)
3229                 goto err;
3230
3231 out:
3232         read_unlock(&state->ss->policy_rwlock);
3233         return rc;
3234
3235 err:
3236         read_unlock(&state->ss->policy_rwlock);
3237         for (i = 0; i < *nperms; i++)
3238                 kfree((*perms)[i]);
3239         kfree(*perms);
3240         return rc;
3241 }
3242
3243 int security_get_reject_unknown(struct selinux_state *state)
3244 {
3245         return state->ss->policydb.reject_unknown;
3246 }
3247
3248 int security_get_allow_unknown(struct selinux_state *state)
3249 {
3250         return state->ss->policydb.allow_unknown;
3251 }
3252
3253 /**
3254  * security_policycap_supported - Check for a specific policy capability
3255  * @req_cap: capability
3256  *
3257  * Description:
3258  * This function queries the currently loaded policy to see if it supports the
3259  * capability specified by @req_cap.  Returns true (1) if the capability is
3260  * supported, false (0) if it isn't supported.
3261  *
3262  */
3263 int security_policycap_supported(struct selinux_state *state,
3264                                  unsigned int req_cap)
3265 {
3266         struct policydb *policydb = &state->ss->policydb;
3267         int rc;
3268
3269         read_lock(&state->ss->policy_rwlock);
3270         rc = ebitmap_get_bit(&policydb->policycaps, req_cap);
3271         read_unlock(&state->ss->policy_rwlock);
3272
3273         return rc;
3274 }
3275
3276 struct selinux_audit_rule {
3277         u32 au_seqno;
3278         struct context au_ctxt;
3279 };
3280
3281 void selinux_audit_rule_free(void *vrule)
3282 {
3283         struct selinux_audit_rule *rule = vrule;
3284
3285         if (rule) {
3286                 context_destroy(&rule->au_ctxt);
3287                 kfree(rule);
3288         }
3289 }
3290
3291 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3292 {
3293         struct selinux_state *state = &selinux_state;
3294         struct policydb *policydb = &state->ss->policydb;
3295         struct selinux_audit_rule *tmprule;
3296         struct role_datum *roledatum;
3297         struct type_datum *typedatum;
3298         struct user_datum *userdatum;
3299         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3300         int rc = 0;
3301
3302         *rule = NULL;
3303
3304         if (!state->initialized)
3305                 return -EOPNOTSUPP;
3306
3307         switch (field) {
3308         case AUDIT_SUBJ_USER:
3309         case AUDIT_SUBJ_ROLE:
3310         case AUDIT_SUBJ_TYPE:
3311         case AUDIT_OBJ_USER:
3312         case AUDIT_OBJ_ROLE:
3313         case AUDIT_OBJ_TYPE:
3314                 /* only 'equals' and 'not equals' fit user, role, and type */
3315                 if (op != Audit_equal && op != Audit_not_equal)
3316                         return -EINVAL;
3317                 break;
3318         case AUDIT_SUBJ_SEN:
3319         case AUDIT_SUBJ_CLR:
3320         case AUDIT_OBJ_LEV_LOW:
3321         case AUDIT_OBJ_LEV_HIGH:
3322                 /* we do not allow a range, indicated by the presence of '-' */
3323                 if (strchr(rulestr, '-'))
3324                         return -EINVAL;
3325                 break;
3326         default:
3327                 /* only the above fields are valid */
3328                 return -EINVAL;
3329         }
3330
3331         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3332         if (!tmprule)
3333                 return -ENOMEM;
3334
3335         context_init(&tmprule->au_ctxt);
3336
3337         read_lock(&state->ss->policy_rwlock);
3338
3339         tmprule->au_seqno = state->ss->latest_granting;
3340
3341         switch (field) {
3342         case AUDIT_SUBJ_USER:
3343         case AUDIT_OBJ_USER:
3344                 rc = -EINVAL;
3345                 userdatum = hashtab_search(policydb->p_users.table, rulestr);
3346                 if (!userdatum)
3347                         goto out;
3348                 tmprule->au_ctxt.user = userdatum->value;
3349                 break;
3350         case AUDIT_SUBJ_ROLE:
3351         case AUDIT_OBJ_ROLE:
3352                 rc = -EINVAL;
3353                 roledatum = hashtab_search(policydb->p_roles.table, rulestr);
3354                 if (!roledatum)
3355                         goto out;
3356                 tmprule->au_ctxt.role = roledatum->value;
3357                 break;
3358         case AUDIT_SUBJ_TYPE:
3359         case AUDIT_OBJ_TYPE:
3360                 rc = -EINVAL;
3361                 typedatum = hashtab_search(policydb->p_types.table, rulestr);
3362                 if (!typedatum)
3363                         goto out;
3364                 tmprule->au_ctxt.type = typedatum->value;
3365                 break;
3366         case AUDIT_SUBJ_SEN:
3367         case AUDIT_SUBJ_CLR:
3368         case AUDIT_OBJ_LEV_LOW:
3369         case AUDIT_OBJ_LEV_HIGH:
3370                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3371                                      GFP_ATOMIC);
3372                 if (rc)
3373                         goto out;
3374                 break;
3375         }
3376         rc = 0;
3377 out:
3378         read_unlock(&state->ss->policy_rwlock);
3379
3380         if (rc) {
3381                 selinux_audit_rule_free(tmprule);
3382                 tmprule = NULL;
3383         }
3384
3385         *rule = tmprule;
3386
3387         return rc;
3388 }
3389
3390 /* Check to see if the rule contains any selinux fields */
3391 int selinux_audit_rule_known(struct audit_krule *rule)
3392 {
3393         int i;
3394
3395         for (i = 0; i < rule->field_count; i++) {
3396                 struct audit_field *f = &rule->fields[i];
3397                 switch (f->type) {
3398                 case AUDIT_SUBJ_USER:
3399                 case AUDIT_SUBJ_ROLE:
3400                 case AUDIT_SUBJ_TYPE:
3401                 case AUDIT_SUBJ_SEN:
3402                 case AUDIT_SUBJ_CLR:
3403                 case AUDIT_OBJ_USER:
3404                 case AUDIT_OBJ_ROLE:
3405                 case AUDIT_OBJ_TYPE:
3406                 case AUDIT_OBJ_LEV_LOW:
3407                 case AUDIT_OBJ_LEV_HIGH:
3408                         return 1;
3409                 }
3410         }
3411
3412         return 0;
3413 }
3414
3415 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3416                              struct audit_context *actx)
3417 {
3418         struct selinux_state *state = &selinux_state;
3419         struct context *ctxt;
3420         struct mls_level *level;
3421         struct selinux_audit_rule *rule = vrule;
3422         int match = 0;
3423
3424         if (unlikely(!rule)) {
3425                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3426                 return -ENOENT;
3427         }
3428
3429         read_lock(&state->ss->policy_rwlock);
3430
3431         if (rule->au_seqno < state->ss->latest_granting) {
3432                 match = -ESTALE;
3433                 goto out;
3434         }
3435
3436         ctxt = sidtab_search(&state->ss->sidtab, sid);
3437         if (unlikely(!ctxt)) {
3438                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3439                           sid);
3440                 match = -ENOENT;
3441                 goto out;
3442         }
3443
3444         /* a field/op pair that is not caught here will simply fall through
3445            without a match */
3446         switch (field) {
3447         case AUDIT_SUBJ_USER:
3448         case AUDIT_OBJ_USER:
3449                 switch (op) {
3450                 case Audit_equal:
3451                         match = (ctxt->user == rule->au_ctxt.user);
3452                         break;
3453                 case Audit_not_equal:
3454                         match = (ctxt->user != rule->au_ctxt.user);
3455                         break;
3456                 }
3457                 break;
3458         case AUDIT_SUBJ_ROLE:
3459         case AUDIT_OBJ_ROLE:
3460                 switch (op) {
3461                 case Audit_equal:
3462                         match = (ctxt->role == rule->au_ctxt.role);
3463                         break;
3464                 case Audit_not_equal:
3465                         match = (ctxt->role != rule->au_ctxt.role);
3466                         break;
3467                 }
3468                 break;
3469         case AUDIT_SUBJ_TYPE:
3470         case AUDIT_OBJ_TYPE:
3471                 switch (op) {
3472                 case Audit_equal:
3473                         match = (ctxt->type == rule->au_ctxt.type);
3474                         break;
3475                 case Audit_not_equal:
3476                         match = (ctxt->type != rule->au_ctxt.type);
3477                         break;
3478                 }
3479                 break;
3480         case AUDIT_SUBJ_SEN:
3481         case AUDIT_SUBJ_CLR:
3482         case AUDIT_OBJ_LEV_LOW:
3483         case AUDIT_OBJ_LEV_HIGH:
3484                 level = ((field == AUDIT_SUBJ_SEN ||
3485                           field == AUDIT_OBJ_LEV_LOW) ?
3486                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3487                 switch (op) {
3488                 case Audit_equal:
3489                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3490                                              level);
3491                         break;
3492                 case Audit_not_equal:
3493                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3494                                               level);
3495                         break;
3496                 case Audit_lt:
3497                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3498                                                level) &&
3499                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3500                                                level));
3501                         break;
3502                 case Audit_le:
3503                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3504                                               level);
3505                         break;
3506                 case Audit_gt:
3507                         match = (mls_level_dom(level,
3508                                               &rule->au_ctxt.range.level[0]) &&
3509                                  !mls_level_eq(level,
3510                                                &rule->au_ctxt.range.level[0]));
3511                         break;
3512                 case Audit_ge:
3513                         match = mls_level_dom(level,
3514                                               &rule->au_ctxt.range.level[0]);
3515                         break;
3516                 }
3517         }
3518
3519 out:
3520         read_unlock(&state->ss->policy_rwlock);
3521         return match;
3522 }
3523
3524 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3525
3526 static int aurule_avc_callback(u32 event)
3527 {
3528         int err = 0;
3529
3530         if (event == AVC_CALLBACK_RESET && aurule_callback)
3531                 err = aurule_callback();
3532         return err;
3533 }
3534
3535 static int __init aurule_init(void)
3536 {
3537         int err;
3538
3539         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3540         if (err)
3541                 panic("avc_add_callback() failed, error %d\n", err);
3542
3543         return err;
3544 }
3545 __initcall(aurule_init);
3546
3547 #ifdef CONFIG_NETLABEL
3548 /**
3549  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3550  * @secattr: the NetLabel packet security attributes
3551  * @sid: the SELinux SID
3552  *
3553  * Description:
3554  * Attempt to cache the context in @ctx, which was derived from the packet in
3555  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3556  * already been initialized.
3557  *
3558  */
3559 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3560                                       u32 sid)
3561 {
3562         u32 *sid_cache;
3563
3564         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3565         if (sid_cache == NULL)
3566                 return;
3567         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3568         if (secattr->cache == NULL) {
3569                 kfree(sid_cache);
3570                 return;
3571         }
3572
3573         *sid_cache = sid;
3574         secattr->cache->free = kfree;
3575         secattr->cache->data = sid_cache;
3576         secattr->flags |= NETLBL_SECATTR_CACHE;
3577 }
3578
3579 /**
3580  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3581  * @secattr: the NetLabel packet security attributes
3582  * @sid: the SELinux SID
3583  *
3584  * Description:
3585  * Convert the given NetLabel security attributes in @secattr into a
3586  * SELinux SID.  If the @secattr field does not contain a full SELinux
3587  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3588  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3589  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3590  * conversion for future lookups.  Returns zero on success, negative values on
3591  * failure.
3592  *
3593  */
3594 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3595                                    struct netlbl_lsm_secattr *secattr,
3596                                    u32 *sid)
3597 {
3598         struct policydb *policydb = &state->ss->policydb;
3599         struct sidtab *sidtab = &state->ss->sidtab;
3600         int rc;
3601         struct context *ctx;
3602         struct context ctx_new;
3603
3604         if (!state->initialized) {
3605                 *sid = SECSID_NULL;
3606                 return 0;
3607         }
3608
3609         read_lock(&state->ss->policy_rwlock);
3610
3611         if (secattr->flags & NETLBL_SECATTR_CACHE)
3612                 *sid = *(u32 *)secattr->cache->data;
3613         else if (secattr->flags & NETLBL_SECATTR_SECID)
3614                 *sid = secattr->attr.secid;
3615         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3616                 rc = -EIDRM;
3617                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3618                 if (ctx == NULL)
3619                         goto out;
3620
3621                 context_init(&ctx_new);
3622                 ctx_new.user = ctx->user;
3623                 ctx_new.role = ctx->role;
3624                 ctx_new.type = ctx->type;
3625                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3626                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3627                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3628                         if (rc)
3629                                 goto out;
3630                 }
3631                 rc = -EIDRM;
3632                 if (!mls_context_isvalid(policydb, &ctx_new))
3633                         goto out_free;
3634
3635                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3636                 if (rc)
3637                         goto out_free;
3638
3639                 security_netlbl_cache_add(secattr, *sid);
3640
3641                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3642         } else
3643                 *sid = SECSID_NULL;
3644
3645         read_unlock(&state->ss->policy_rwlock);
3646         return 0;
3647 out_free:
3648         ebitmap_destroy(&ctx_new.range.level[0].cat);
3649 out:
3650         read_unlock(&state->ss->policy_rwlock);
3651         return rc;
3652 }
3653
3654 /**
3655  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3656  * @sid: the SELinux SID
3657  * @secattr: the NetLabel packet security attributes
3658  *
3659  * Description:
3660  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3661  * Returns zero on success, negative values on failure.
3662  *
3663  */
3664 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3665                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3666 {
3667         struct policydb *policydb = &state->ss->policydb;
3668         int rc;
3669         struct context *ctx;
3670
3671         if (!state->initialized)
3672                 return 0;
3673
3674         read_lock(&state->ss->policy_rwlock);
3675
3676         rc = -ENOENT;
3677         ctx = sidtab_search(&state->ss->sidtab, sid);
3678         if (ctx == NULL)
3679                 goto out;
3680
3681         rc = -ENOMEM;
3682         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3683                                   GFP_ATOMIC);
3684         if (secattr->domain == NULL)
3685                 goto out;
3686
3687         secattr->attr.secid = sid;
3688         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3689         mls_export_netlbl_lvl(policydb, ctx, secattr);
3690         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3691 out:
3692         read_unlock(&state->ss->policy_rwlock);
3693         return rc;
3694 }
3695 #endif /* CONFIG_NETLABEL */
3696
3697 /**
3698  * security_read_policy - read the policy.
3699  * @data: binary policy data
3700  * @len: length of data in bytes
3701  *
3702  */
3703 int security_read_policy(struct selinux_state *state,
3704                          void **data, size_t *len)
3705 {
3706         struct policydb *policydb = &state->ss->policydb;
3707         int rc;
3708         struct policy_file fp;
3709
3710         if (!state->initialized)
3711                 return -EINVAL;
3712
3713         *len = security_policydb_len(state);
3714
3715         *data = vmalloc_user(*len);
3716         if (!*data)
3717                 return -ENOMEM;
3718
3719         fp.data = *data;
3720         fp.len = *len;
3721
3722         read_lock(&state->ss->policy_rwlock);
3723         rc = policydb_write(policydb, &fp);
3724         read_unlock(&state->ss->policy_rwlock);
3725
3726         if (rc)
3727                 return rc;
3728
3729         *len = (unsigned long)fp.data - (unsigned long)*data;
3730         return 0;
3731
3732 }