security/selinux/ss/services.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Implementation of the security services.
   4  *
   5  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
   6  *           James Morris <jmorris@redhat.com>
   7  *
   8  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   9  *
  10  *      Support for enhanced MLS infrastructure.
  11  *      Support for context based audit filters.
  12  *
  13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  14  *
  15  *      Added conditional policy language extensions
  16  *
  17  * Updated: Hewlett-Packard <paul@paul-moore.com>
  18  *
  19  *      Added support for NetLabel
  20  *      Added support for the policy capability bitmap
  21  *
  22  * Updated: Chad Sellers <csellers@tresys.com>
  23  *
  24  *  Added validation of kernel classes and permissions
  25  *
  26  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  27  *
  28  *  Added support for bounds domain and audit messaged on masked permissions
  29  *
  30  * Updated: Guido Trentalancia <guido@trentalancia.com>
  31  *
  32  *  Added support for runtime switching of the policy type
  33  *
  34  * Copyright (C) 2008, 2009 NEC Corporation
  35  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  36  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  37  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  38  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  39  */
  40 #include <linux/kernel.h>
  41 #include <linux/slab.h>
  42 #include <linux/string.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/rcupdate.h>
  45 #include <linux/errno.h>
  46 #include <linux/in.h>
  47 #include <linux/sched.h>
  48 #include <linux/audit.h>
  49 #include <linux/mutex.h>
  50 #include <linux/vmalloc.h>
  51 #include <net/netlabel.h>
  52
  53 #include "flask.h"
  54 #include "avc.h"
  55 #include "avc_ss.h"
  56 #include "security.h"
  57 #include "context.h"
  58 #include "policydb.h"
  59 #include "sidtab.h"
  60 #include "services.h"
  61 #include "conditional.h"
  62 #include "mls.h"
  63 #include "objsec.h"
  64 #include "netlabel.h"
  65 #include "xfrm.h"
  66 #include "ebitmap.h"
  67 #include "audit.h"
  68
  69 /* Policy capability names */
  70 const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
  71         "network_peer_controls",
  72         "open_perms",
  73         "extended_socket_class",
  74         "always_check_network",
  75         "cgroup_seclabel",
  76         "nnp_nosuid_transition"
  77 };
  78
  79 static struct selinux_ss selinux_ss;
  80
  81 void selinux_ss_init(struct selinux_ss **ss)
  82 {
  83         rwlock_init(&selinux_ss.policy_rwlock);
  84         mutex_init(&selinux_ss.status_lock);
  85         *ss = &selinux_ss;
  86 }
  87
  88 /* Forward declaration. */
  89 static int context_struct_to_string(struct policydb *policydb,
  90                                     struct context *context,
  91                                     char **scontext,
  92                                     u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct policydb *policydb,
  95                                       struct context *scontext,
  96                                       struct context *tcontext,
  97                                       u16 tclass,
  98                                       struct av_decision *avd,
  99                                       struct extended_perms *xperms);
 100
 101 static int selinux_set_mapping(struct policydb *pol,
 102                                struct security_class_mapping *map,
 103                                struct selinux_map *out_map)
 104 {
 105         u16 i, j;
 106         unsigned k;
 107         bool print_unknown_handle = false;
 108
 109         /* Find number of classes in the input mapping */
 110         if (!map)
 111                 return -EINVAL;
 112         i = 0;
 113         while (map[i].name)
 114                 i++;
 115
 116         /* Allocate space for the class records, plus one for class zero */
 117         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 118         if (!out_map->mapping)
 119                 return -ENOMEM;
 120
 121         /* Store the raw class and permission values */
 122         j = 0;
 123         while (map[j].name) {
 124                 struct security_class_mapping *p_in = map + (j++);
 125                 struct selinux_mapping *p_out = out_map->mapping + j;
 126
 127                 /* An empty class string skips ahead */
 128                 if (!strcmp(p_in->name, "")) {
 129                         p_out->num_perms = 0;
 130                         continue;
 131                 }
 132
 133                 p_out->value = string_to_security_class(pol, p_in->name);
 134                 if (!p_out->value) {
 135                         pr_info("SELinux:  Class %s not defined in policy.\n",
 136                                p_in->name);
 137                         if (pol->reject_unknown)
 138                                 goto err;
 139                         p_out->num_perms = 0;
 140                         print_unknown_handle = true;
 141                         continue;
 142                 }
 143
 144                 k = 0;
 145                 while (p_in->perms[k]) {
 146                         /* An empty permission string skips ahead */
 147                         if (!*p_in->perms[k]) {
 148                                 k++;
 149                                 continue;
 150                         }
 151                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 152                                                             p_in->perms[k]);
 153                         if (!p_out->perms[k]) {
 154                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 155                                        p_in->perms[k], p_in->name);
 156                                 if (pol->reject_unknown)
 157                                         goto err;
 158                                 print_unknown_handle = true;
 159                         }
 160
 161                         k++;
 162                 }
 163                 p_out->num_perms = k;
 164         }
 165
 166         if (print_unknown_handle)
 167                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 168                        pol->allow_unknown ? "allowed" : "denied");
 169
 170         out_map->size = i;
 171         return 0;
 172 err:
 173         kfree(out_map->mapping);
 174         out_map->mapping = NULL;
 175         return -EINVAL;
 176 }
 177
 178 /*
 179  * Get real, policy values from mapped values
 180  */
 181
 182 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 183 {
 184         if (tclass < map->size)
 185                 return map->mapping[tclass].value;
 186
 187         return tclass;
 188 }
 189
 190 /*
 191  * Get kernel value for class from its policy value
 192  */
 193 static u16 map_class(struct selinux_map *map, u16 pol_value)
 194 {
 195         u16 i;
 196
 197         for (i = 1; i < map->size; i++) {
 198                 if (map->mapping[i].value == pol_value)
 199                         return i;
 200         }
 201
 202         return SECCLASS_NULL;
 203 }
 204
 205 static void map_decision(struct selinux_map *map,
 206                          u16 tclass, struct av_decision *avd,
 207                          int allow_unknown)
 208 {
 209         if (tclass < map->size) {
 210                 struct selinux_mapping *mapping = &map->mapping[tclass];
 211                 unsigned int i, n = mapping->num_perms;
 212                 u32 result;
 213
 214                 for (i = 0, result = 0; i < n; i++) {
 215                         if (avd->allowed & mapping->perms[i])
 216                                 result |= 1<<i;
 217                         if (allow_unknown && !mapping->perms[i])
 218                                 result |= 1<<i;
 219                 }
 220                 avd->allowed = result;
 221
 222                 for (i = 0, result = 0; i < n; i++)
 223                         if (avd->auditallow & mapping->perms[i])
 224                                 result |= 1<<i;
 225                 avd->auditallow = result;
 226
 227                 for (i = 0, result = 0; i < n; i++) {
 228                         if (avd->auditdeny & mapping->perms[i])
 229                                 result |= 1<<i;
 230                         if (!allow_unknown && !mapping->perms[i])
 231                                 result |= 1<<i;
 232                 }
 233                 /*
 234                  * In case the kernel has a bug and requests a permission
 235                  * between num_perms and the maximum permission number, we
 236                  * should audit that denial
 237                  */
 238                 for (; i < (sizeof(u32)*8); i++)
 239                         result |= 1<<i;
 240                 avd->auditdeny = result;
 241         }
 242 }
 243
 244 int security_mls_enabled(struct selinux_state *state)
 245 {
 246         struct policydb *p = &state->ss->policydb;
 247
 248         return p->mls_enabled;
 249 }
 250
 251 /*
 252  * Return the boolean value of a constraint expression
 253  * when it is applied to the specified source and target
 254  * security contexts.
 255  *
 256  * xcontext is a special beast...  It is used by the validatetrans rules
 257  * only.  For these rules, scontext is the context before the transition,
 258  * tcontext is the context after the transition, and xcontext is the context
 259  * of the process performing the transition.  All other callers of
 260  * constraint_expr_eval should pass in NULL for xcontext.
 261  */
 262 static int constraint_expr_eval(struct policydb *policydb,
 263                                 struct context *scontext,
 264                                 struct context *tcontext,
 265                                 struct context *xcontext,
 266                                 struct constraint_expr *cexpr)
 267 {
 268         u32 val1, val2;
 269         struct context *c;
 270         struct role_datum *r1, *r2;
 271         struct mls_level *l1, *l2;
 272         struct constraint_expr *e;
 273         int s[CEXPR_MAXDEPTH];
 274         int sp = -1;
 275
 276         for (e = cexpr; e; e = e->next) {
 277                 switch (e->expr_type) {
 278                 case CEXPR_NOT:
 279                         BUG_ON(sp < 0);
 280                         s[sp] = !s[sp];
 281                         break;
 282                 case CEXPR_AND:
 283                         BUG_ON(sp < 1);
 284                         sp--;
 285                         s[sp] &= s[sp + 1];
 286                         break;
 287                 case CEXPR_OR:
 288                         BUG_ON(sp < 1);
 289                         sp--;
 290                         s[sp] |= s[sp + 1];
 291                         break;
 292                 case CEXPR_ATTR:
 293                         if (sp == (CEXPR_MAXDEPTH - 1))
 294                                 return 0;
 295                         switch (e->attr) {
 296                         case CEXPR_USER:
 297                                 val1 = scontext->user;
 298                                 val2 = tcontext->user;
 299                                 break;
 300                         case CEXPR_TYPE:
 301                                 val1 = scontext->type;
 302                                 val2 = tcontext->type;
 303                                 break;
 304                         case CEXPR_ROLE:
 305                                 val1 = scontext->role;
 306                                 val2 = tcontext->role;
 307                                 r1 = policydb->role_val_to_struct[val1 - 1];
 308                                 r2 = policydb->role_val_to_struct[val2 - 1];
 309                                 switch (e->op) {
 310                                 case CEXPR_DOM:
 311                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 312                                                                   val2 - 1);
 313                                         continue;
 314                                 case CEXPR_DOMBY:
 315                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 316                                                                   val1 - 1);
 317                                         continue;
 318                                 case CEXPR_INCOMP:
 319                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 320                                                                     val2 - 1) &&
 321                                                    !ebitmap_get_bit(&r2->dominates,
 322                                                                     val1 - 1));
 323                                         continue;
 324                                 default:
 325                                         break;
 326                                 }
 327                                 break;
 328                         case CEXPR_L1L2:
 329                                 l1 = &(scontext->range.level[0]);
 330                                 l2 = &(tcontext->range.level[0]);
 331                                 goto mls_ops;
 332                         case CEXPR_L1H2:
 333                                 l1 = &(scontext->range.level[0]);
 334                                 l2 = &(tcontext->range.level[1]);
 335                                 goto mls_ops;
 336                         case CEXPR_H1L2:
 337                                 l1 = &(scontext->range.level[1]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_H1H2:
 341                                 l1 = &(scontext->range.level[1]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_L1H1:
 345                                 l1 = &(scontext->range.level[0]);
 346                                 l2 = &(scontext->range.level[1]);
 347                                 goto mls_ops;
 348                         case CEXPR_L2H2:
 349                                 l1 = &(tcontext->range.level[0]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352 mls_ops:
 353                         switch (e->op) {
 354                         case CEXPR_EQ:
 355                                 s[++sp] = mls_level_eq(l1, l2);
 356                                 continue;
 357                         case CEXPR_NEQ:
 358                                 s[++sp] = !mls_level_eq(l1, l2);
 359                                 continue;
 360                         case CEXPR_DOM:
 361                                 s[++sp] = mls_level_dom(l1, l2);
 362                                 continue;
 363                         case CEXPR_DOMBY:
 364                                 s[++sp] = mls_level_dom(l2, l1);
 365                                 continue;
 366                         case CEXPR_INCOMP:
 367                                 s[++sp] = mls_level_incomp(l2, l1);
 368                                 continue;
 369                         default:
 370                                 BUG();
 371                                 return 0;
 372                         }
 373                         break;
 374                         default:
 375                                 BUG();
 376                                 return 0;
 377                         }
 378
 379                         switch (e->op) {
 380                         case CEXPR_EQ:
 381                                 s[++sp] = (val1 == val2);
 382                                 break;
 383                         case CEXPR_NEQ:
 384                                 s[++sp] = (val1 != val2);
 385                                 break;
 386                         default:
 387                                 BUG();
 388                                 return 0;
 389                         }
 390                         break;
 391                 case CEXPR_NAMES:
 392                         if (sp == (CEXPR_MAXDEPTH-1))
 393                                 return 0;
 394                         c = scontext;
 395                         if (e->attr & CEXPR_TARGET)
 396                                 c = tcontext;
 397                         else if (e->attr & CEXPR_XTARGET) {
 398                                 c = xcontext;
 399                                 if (!c) {
 400                                         BUG();
 401                                         return 0;
 402                                 }
 403                         }
 404                         if (e->attr & CEXPR_USER)
 405                                 val1 = c->user;
 406                         else if (e->attr & CEXPR_ROLE)
 407                                 val1 = c->role;
 408                         else if (e->attr & CEXPR_TYPE)
 409                                 val1 = c->type;
 410                         else {
 411                                 BUG();
 412                                 return 0;
 413                         }
 414
 415                         switch (e->op) {
 416                         case CEXPR_EQ:
 417                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 418                                 break;
 419                         case CEXPR_NEQ:
 420                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 421                                 break;
 422                         default:
 423                                 BUG();
 424                                 return 0;
 425                         }
 426                         break;
 427                 default:
 428                         BUG();
 429                         return 0;
 430                 }
 431         }
 432
 433         BUG_ON(sp != 0);
 434         return s[0];
 435 }
 436
 437 /*
 438  * security_dump_masked_av - dumps masked permissions during
 439  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 440  */
 441 static int dump_masked_av_helper(void *k, void *d, void *args)
 442 {
 443         struct perm_datum *pdatum = d;
 444         char **permission_names = args;
 445
 446         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 447
 448         permission_names[pdatum->value - 1] = (char *)k;
 449
 450         return 0;
 451 }
 452
 453 static void security_dump_masked_av(struct policydb *policydb,
 454                                     struct context *scontext,
 455                                     struct context *tcontext,
 456                                     u16 tclass,
 457                                     u32 permissions,
 458                                     const char *reason)
 459 {
 460         struct common_datum *common_dat;
 461         struct class_datum *tclass_dat;
 462         struct audit_buffer *ab;
 463         char *tclass_name;
 464         char *scontext_name = NULL;
 465         char *tcontext_name = NULL;
 466         char *permission_names[32];
 467         int index;
 468         u32 length;
 469         bool need_comma = false;
 470
 471         if (!permissions)
 472                 return;
 473
 474         tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
 475         tclass_dat = policydb->class_val_to_struct[tclass - 1];
 476         common_dat = tclass_dat->comdatum;
 477
 478         /* init permission_names */
 479         if (common_dat &&
 480             hashtab_map(common_dat->permissions.table,
 481                         dump_masked_av_helper, permission_names) < 0)
 482                 goto out;
 483
 484         if (hashtab_map(tclass_dat->permissions.table,
 485                         dump_masked_av_helper, permission_names) < 0)
 486                 goto out;
 487
 488         /* get scontext/tcontext in text form */
 489         if (context_struct_to_string(policydb, scontext,
 490                                      &scontext_name, &length) < 0)
 491                 goto out;
 492
 493         if (context_struct_to_string(policydb, tcontext,
 494                                      &tcontext_name, &length) < 0)
 495                 goto out;
 496
 497         /* audit a message */
 498         ab = audit_log_start(audit_context(),
 499                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 500         if (!ab)
 501                 goto out;
 502
 503         audit_log_format(ab, "op=security_compute_av reason=%s "
 504                          "scontext=%s tcontext=%s tclass=%s perms=",
 505                          reason, scontext_name, tcontext_name, tclass_name);
 506
 507         for (index = 0; index < 32; index++) {
 508                 u32 mask = (1 << index);
 509
 510                 if ((mask & permissions) == 0)
 511                         continue;
 512
 513                 audit_log_format(ab, "%s%s",
 514                                  need_comma ? "," : "",
 515                                  permission_names[index]
 516                                  ? permission_names[index] : "????");
 517                 need_comma = true;
 518         }
 519         audit_log_end(ab);
 520 out:
 521         /* release scontext/tcontext */
 522         kfree(tcontext_name);
 523         kfree(scontext_name);
 524
 525         return;
 526 }
 527
 528 /*
 529  * security_boundary_permission - drops violated permissions
 530  * on boundary constraint.
 531  */
 532 static void type_attribute_bounds_av(struct policydb *policydb,
 533                                      struct context *scontext,
 534                                      struct context *tcontext,
 535                                      u16 tclass,
 536                                      struct av_decision *avd)
 537 {
 538         struct context lo_scontext;
 539         struct context lo_tcontext, *tcontextp = tcontext;
 540         struct av_decision lo_avd;
 541         struct type_datum *source;
 542         struct type_datum *target;
 543         u32 masked = 0;
 544
 545         source = policydb->type_val_to_struct[scontext->type - 1];
 546         BUG_ON(!source);
 547
 548         if (!source->bounds)
 549                 return;
 550
 551         target = policydb->type_val_to_struct[tcontext->type - 1];
 552         BUG_ON(!target);
 553
 554         memset(&lo_avd, 0, sizeof(lo_avd));
 555
 556         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 557         lo_scontext.type = source->bounds;
 558
 559         if (target->bounds) {
 560                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 561                 lo_tcontext.type = target->bounds;
 562                 tcontextp = &lo_tcontext;
 563         }
 564
 565         context_struct_compute_av(policydb, &lo_scontext,
 566                                   tcontextp,
 567                                   tclass,
 568                                   &lo_avd,
 569                                   NULL);
 570
 571         masked = ~lo_avd.allowed & avd->allowed;
 572
 573         if (likely(!masked))
 574                 return;         /* no masked permission */
 575
 576         /* mask violated permissions */
 577         avd->allowed &= ~masked;
 578
 579         /* audit masked permissions */
 580         security_dump_masked_av(policydb, scontext, tcontext,
 581                                 tclass, masked, "bounds");
 582 }
 583
 584 /*
 585  * flag which drivers have permissions
 586  * only looking for ioctl based extended permssions
 587  */
 588 void services_compute_xperms_drivers(
 589                 struct extended_perms *xperms,
 590                 struct avtab_node *node)
 591 {
 592         unsigned int i;
 593
 594         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 595                 /* if one or more driver has all permissions allowed */
 596                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 597                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 598         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 599                 /* if allowing permissions within a driver */
 600                 security_xperm_set(xperms->drivers.p,
 601                                         node->datum.u.xperms->driver);
 602         }
 603
 604         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 605         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 606                 xperms->len = 1;
 607 }
 608
 609 /*
 610  * Compute access vectors and extended permissions based on a context
 611  * structure pair for the permissions in a particular class.
 612  */
 613 static void context_struct_compute_av(struct policydb *policydb,
 614                                       struct context *scontext,
 615                                       struct context *tcontext,
 616                                       u16 tclass,
 617                                       struct av_decision *avd,
 618                                       struct extended_perms *xperms)
 619 {
 620         struct constraint_node *constraint;
 621         struct role_allow *ra;
 622         struct avtab_key avkey;
 623         struct avtab_node *node;
 624         struct class_datum *tclass_datum;
 625         struct ebitmap *sattr, *tattr;
 626         struct ebitmap_node *snode, *tnode;
 627         unsigned int i, j;
 628
 629         avd->allowed = 0;
 630         avd->auditallow = 0;
 631         avd->auditdeny = 0xffffffff;
 632         if (xperms) {
 633                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 634                 xperms->len = 0;
 635         }
 636
 637         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 638                 if (printk_ratelimit())
 639                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 640                 return;
 641         }
 642
 643         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 644
 645         /*
 646          * If a specific type enforcement rule was defined for
 647          * this permission check, then use it.
 648          */
 649         avkey.target_class = tclass;
 650         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 651         sattr = &policydb->type_attr_map_array[scontext->type - 1];
 652         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 653         ebitmap_for_each_positive_bit(sattr, snode, i) {
 654                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 655                         avkey.source_type = i + 1;
 656                         avkey.target_type = j + 1;
 657                         for (node = avtab_search_node(&policydb->te_avtab,
 658                                                       &avkey);
 659                              node;
 660                              node = avtab_search_node_next(node, avkey.specified)) {
 661                                 if (node->key.specified == AVTAB_ALLOWED)
 662                                         avd->allowed |= node->datum.u.data;
 663                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 664                                         avd->auditallow |= node->datum.u.data;
 665                                 else if (node->key.specified == AVTAB_AUDITDENY)
 666                                         avd->auditdeny &= node->datum.u.data;
 667                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 668                                         services_compute_xperms_drivers(xperms, node);
 669                         }
 670
 671                         /* Check conditional av table for additional permissions */
 672                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 673                                         avd, xperms);
 674
 675                 }
 676         }
 677
 678         /*
 679          * Remove any permissions prohibited by a constraint (this includes
 680          * the MLS policy).
 681          */
 682         constraint = tclass_datum->constraints;
 683         while (constraint) {
 684                 if ((constraint->permissions & (avd->allowed)) &&
 685                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 686                                           constraint->expr)) {
 687                         avd->allowed &= ~(constraint->permissions);
 688                 }
 689                 constraint = constraint->next;
 690         }
 691
 692         /*
 693          * If checking process transition permission and the
 694          * role is changing, then check the (current_role, new_role)
 695          * pair.
 696          */
 697         if (tclass == policydb->process_class &&
 698             (avd->allowed & policydb->process_trans_perms) &&
 699             scontext->role != tcontext->role) {
 700                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 701                         if (scontext->role == ra->role &&
 702                             tcontext->role == ra->new_role)
 703                                 break;
 704                 }
 705                 if (!ra)
 706                         avd->allowed &= ~policydb->process_trans_perms;
 707         }
 708
 709         /*
 710          * If the given source and target types have boundary
 711          * constraint, lazy checks have to mask any violated
 712          * permission and notice it to userspace via audit.
 713          */
 714         type_attribute_bounds_av(policydb, scontext, tcontext,
 715                                  tclass, avd);
 716 }
 717
 718 static int security_validtrans_handle_fail(struct selinux_state *state,
 719                                            struct context *ocontext,
 720                                            struct context *ncontext,
 721                                            struct context *tcontext,
 722                                            u16 tclass)
 723 {
 724         struct policydb *p = &state->ss->policydb;
 725         char *o = NULL, *n = NULL, *t = NULL;
 726         u32 olen, nlen, tlen;
 727
 728         if (context_struct_to_string(p, ocontext, &o, &olen))
 729                 goto out;
 730         if (context_struct_to_string(p, ncontext, &n, &nlen))
 731                 goto out;
 732         if (context_struct_to_string(p, tcontext, &t, &tlen))
 733                 goto out;
 734         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 735                   "op=security_validate_transition seresult=denied"
 736                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 737                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 738 out:
 739         kfree(o);
 740         kfree(n);
 741         kfree(t);
 742
 743         if (!enforcing_enabled(state))
 744                 return 0;
 745         return -EPERM;
 746 }
 747
 748 static int security_compute_validatetrans(struct selinux_state *state,
 749                                           u32 oldsid, u32 newsid, u32 tasksid,
 750                                           u16 orig_tclass, bool user)
 751 {
 752         struct policydb *policydb;
 753         struct sidtab *sidtab;
 754         struct context *ocontext;
 755         struct context *ncontext;
 756         struct context *tcontext;
 757         struct class_datum *tclass_datum;
 758         struct constraint_node *constraint;
 759         u16 tclass;
 760         int rc = 0;
 761
 762
 763         if (!state->initialized)
 764                 return 0;
 765
 766         read_lock(&state->ss->policy_rwlock);
 767
 768         policydb = &state->ss->policydb;
 769         sidtab = state->ss->sidtab;
 770
 771         if (!user)
 772                 tclass = unmap_class(&state->ss->map, orig_tclass);
 773         else
 774                 tclass = orig_tclass;
 775
 776         if (!tclass || tclass > policydb->p_classes.nprim) {
 777                 rc = -EINVAL;
 778                 goto out;
 779         }
 780         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 781
 782         ocontext = sidtab_search(sidtab, oldsid);
 783         if (!ocontext) {
 784                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 785                         __func__, oldsid);
 786                 rc = -EINVAL;
 787                 goto out;
 788         }
 789
 790         ncontext = sidtab_search(sidtab, newsid);
 791         if (!ncontext) {
 792                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 793                         __func__, newsid);
 794                 rc = -EINVAL;
 795                 goto out;
 796         }
 797
 798         tcontext = sidtab_search(sidtab, tasksid);
 799         if (!tcontext) {
 800                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 801                         __func__, tasksid);
 802                 rc = -EINVAL;
 803                 goto out;
 804         }
 805
 806         constraint = tclass_datum->validatetrans;
 807         while (constraint) {
 808                 if (!constraint_expr_eval(policydb, ocontext, ncontext,
 809                                           tcontext, constraint->expr)) {
 810                         if (user)
 811                                 rc = -EPERM;
 812                         else
 813                                 rc = security_validtrans_handle_fail(state,
 814                                                                      ocontext,
 815                                                                      ncontext,
 816                                                                      tcontext,
 817                                                                      tclass);
 818                         goto out;
 819                 }
 820                 constraint = constraint->next;
 821         }
 822
 823 out:
 824         read_unlock(&state->ss->policy_rwlock);
 825         return rc;
 826 }
 827
 828 int security_validate_transition_user(struct selinux_state *state,
 829                                       u32 oldsid, u32 newsid, u32 tasksid,
 830                                       u16 tclass)
 831 {
 832         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 833                                               tclass, true);
 834 }
 835
 836 int security_validate_transition(struct selinux_state *state,
 837                                  u32 oldsid, u32 newsid, u32 tasksid,
 838                                  u16 orig_tclass)
 839 {
 840         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 841                                               orig_tclass, false);
 842 }
 843
 844 /*
 845  * security_bounded_transition - check whether the given
 846  * transition is directed to bounded, or not.
 847  * It returns 0, if @newsid is bounded by @oldsid.
 848  * Otherwise, it returns error code.
 849  *
 850  * @oldsid : current security identifier
 851  * @newsid : destinated security identifier
 852  */
 853 int security_bounded_transition(struct selinux_state *state,
 854                                 u32 old_sid, u32 new_sid)
 855 {
 856         struct policydb *policydb;
 857         struct sidtab *sidtab;
 858         struct context *old_context, *new_context;
 859         struct type_datum *type;
 860         int index;
 861         int rc;
 862
 863         if (!state->initialized)
 864                 return 0;
 865
 866         read_lock(&state->ss->policy_rwlock);
 867
 868         policydb = &state->ss->policydb;
 869         sidtab = state->ss->sidtab;
 870
 871         rc = -EINVAL;
 872         old_context = sidtab_search(sidtab, old_sid);
 873         if (!old_context) {
 874                 pr_err("SELinux: %s: unrecognized SID %u\n",
 875                        __func__, old_sid);
 876                 goto out;
 877         }
 878
 879         rc = -EINVAL;
 880         new_context = sidtab_search(sidtab, new_sid);
 881         if (!new_context) {
 882                 pr_err("SELinux: %s: unrecognized SID %u\n",
 883                        __func__, new_sid);
 884                 goto out;
 885         }
 886
 887         rc = 0;
 888         /* type/domain unchanged */
 889         if (old_context->type == new_context->type)
 890                 goto out;
 891
 892         index = new_context->type;
 893         while (true) {
 894                 type = policydb->type_val_to_struct[index - 1];
 895                 BUG_ON(!type);
 896
 897                 /* not bounded anymore */
 898                 rc = -EPERM;
 899                 if (!type->bounds)
 900                         break;
 901
 902                 /* @newsid is bounded by @oldsid */
 903                 rc = 0;
 904                 if (type->bounds == old_context->type)
 905                         break;
 906
 907                 index = type->bounds;
 908         }
 909
 910         if (rc) {
 911                 char *old_name = NULL;
 912                 char *new_name = NULL;
 913                 u32 length;
 914
 915                 if (!context_struct_to_string(policydb, old_context,
 916                                               &old_name, &length) &&
 917                     !context_struct_to_string(policydb, new_context,
 918                                               &new_name, &length)) {
 919                         audit_log(audit_context(),
 920                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 921                                   "op=security_bounded_transition "
 922                                   "seresult=denied "
 923                                   "oldcontext=%s newcontext=%s",
 924                                   old_name, new_name);
 925                 }
 926                 kfree(new_name);
 927                 kfree(old_name);
 928         }
 929 out:
 930         read_unlock(&state->ss->policy_rwlock);
 931
 932         return rc;
 933 }
 934
 935 static void avd_init(struct selinux_state *state, struct av_decision *avd)
 936 {
 937         avd->allowed = 0;
 938         avd->auditallow = 0;
 939         avd->auditdeny = 0xffffffff;
 940         avd->seqno = state->ss->latest_granting;
 941         avd->flags = 0;
 942 }
 943
 944 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 945                                         struct avtab_node *node)
 946 {
 947         unsigned int i;
 948
 949         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 950                 if (xpermd->driver != node->datum.u.xperms->driver)
 951                         return;
 952         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 953                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 954                                         xpermd->driver))
 955                         return;
 956         } else {
 957                 BUG();
 958         }
 959
 960         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 961                 xpermd->used |= XPERMS_ALLOWED;
 962                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 963                         memset(xpermd->allowed->p, 0xff,
 964                                         sizeof(xpermd->allowed->p));
 965                 }
 966                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 967                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 968                                 xpermd->allowed->p[i] |=
 969                                         node->datum.u.xperms->perms.p[i];
 970                 }
 971         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 972                 xpermd->used |= XPERMS_AUDITALLOW;
 973                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 974                         memset(xpermd->auditallow->p, 0xff,
 975                                         sizeof(xpermd->auditallow->p));
 976                 }
 977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 978                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 979                                 xpermd->auditallow->p[i] |=
 980                                         node->datum.u.xperms->perms.p[i];
 981                 }
 982         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 983                 xpermd->used |= XPERMS_DONTAUDIT;
 984                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 985                         memset(xpermd->dontaudit->p, 0xff,
 986                                         sizeof(xpermd->dontaudit->p));
 987                 }
 988                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 989                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 990                                 xpermd->dontaudit->p[i] |=
 991                                         node->datum.u.xperms->perms.p[i];
 992                 }
 993         } else {
 994                 BUG();
 995         }
 996 }
 997
 998 void security_compute_xperms_decision(struct selinux_state *state,
 999                                       u32 ssid,
1000                                       u32 tsid,
1001                                       u16 orig_tclass,
1002                                       u8 driver,
1003                                       struct extended_perms_decision *xpermd)
1004 {
1005         struct policydb *policydb;
1006         struct sidtab *sidtab;
1007         u16 tclass;
1008         struct context *scontext, *tcontext;
1009         struct avtab_key avkey;
1010         struct avtab_node *node;
1011         struct ebitmap *sattr, *tattr;
1012         struct ebitmap_node *snode, *tnode;
1013         unsigned int i, j;
1014
1015         xpermd->driver = driver;
1016         xpermd->used = 0;
1017         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1018         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1019         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1020
1021         read_lock(&state->ss->policy_rwlock);
1022         if (!state->initialized)
1023                 goto allow;
1024
1025         policydb = &state->ss->policydb;
1026         sidtab = state->ss->sidtab;
1027
1028         scontext = sidtab_search(sidtab, ssid);
1029         if (!scontext) {
1030                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1031                        __func__, ssid);
1032                 goto out;
1033         }
1034
1035         tcontext = sidtab_search(sidtab, tsid);
1036         if (!tcontext) {
1037                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1038                        __func__, tsid);
1039                 goto out;
1040         }
1041
1042         tclass = unmap_class(&state->ss->map, orig_tclass);
1043         if (unlikely(orig_tclass && !tclass)) {
1044                 if (policydb->allow_unknown)
1045                         goto allow;
1046                 goto out;
1047         }
1048
1049
1050         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1051                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1052                 goto out;
1053         }
1054
1055         avkey.target_class = tclass;
1056         avkey.specified = AVTAB_XPERMS;
1057         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1058         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1059         ebitmap_for_each_positive_bit(sattr, snode, i) {
1060                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1061                         avkey.source_type = i + 1;
1062                         avkey.target_type = j + 1;
1063                         for (node = avtab_search_node(&policydb->te_avtab,
1064                                                       &avkey);
1065                              node;
1066                              node = avtab_search_node_next(node, avkey.specified))
1067                                 services_compute_xperms_decision(xpermd, node);
1068
1069                         cond_compute_xperms(&policydb->te_cond_avtab,
1070                                                 &avkey, xpermd);
1071                 }
1072         }
1073 out:
1074         read_unlock(&state->ss->policy_rwlock);
1075         return;
1076 allow:
1077         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1078         goto out;
1079 }
1080
1081 /**
1082  * security_compute_av - Compute access vector decisions.
1083  * @ssid: source security identifier
1084  * @tsid: target security identifier
1085  * @tclass: target security class
1086  * @avd: access vector decisions
1087  * @xperms: extended permissions
1088  *
1089  * Compute a set of access vector decisions based on the
1090  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1091  */
1092 void security_compute_av(struct selinux_state *state,
1093                          u32 ssid,
1094                          u32 tsid,
1095                          u16 orig_tclass,
1096                          struct av_decision *avd,
1097                          struct extended_perms *xperms)
1098 {
1099         struct policydb *policydb;
1100         struct sidtab *sidtab;
1101         u16 tclass;
1102         struct context *scontext = NULL, *tcontext = NULL;
1103
1104         read_lock(&state->ss->policy_rwlock);
1105         avd_init(state, avd);
1106         xperms->len = 0;
1107         if (!state->initialized)
1108                 goto allow;
1109
1110         policydb = &state->ss->policydb;
1111         sidtab = state->ss->sidtab;
1112
1113         scontext = sidtab_search(sidtab, ssid);
1114         if (!scontext) {
1115                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1116                        __func__, ssid);
1117                 goto out;
1118         }
1119
1120         /* permissive domain? */
1121         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1122                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1123
1124         tcontext = sidtab_search(sidtab, tsid);
1125         if (!tcontext) {
1126                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1127                        __func__, tsid);
1128                 goto out;
1129         }
1130
1131         tclass = unmap_class(&state->ss->map, orig_tclass);
1132         if (unlikely(orig_tclass && !tclass)) {
1133                 if (policydb->allow_unknown)
1134                         goto allow;
1135                 goto out;
1136         }
1137         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1138                                   xperms);
1139         map_decision(&state->ss->map, orig_tclass, avd,
1140                      policydb->allow_unknown);
1141 out:
1142         read_unlock(&state->ss->policy_rwlock);
1143         return;
1144 allow:
1145         avd->allowed = 0xffffffff;
1146         goto out;
1147 }
1148
1149 void security_compute_av_user(struct selinux_state *state,
1150                               u32 ssid,
1151                               u32 tsid,
1152                               u16 tclass,
1153                               struct av_decision *avd)
1154 {
1155         struct policydb *policydb;
1156         struct sidtab *sidtab;
1157         struct context *scontext = NULL, *tcontext = NULL;
1158
1159         read_lock(&state->ss->policy_rwlock);
1160         avd_init(state, avd);
1161         if (!state->initialized)
1162                 goto allow;
1163
1164         policydb = &state->ss->policydb;
1165         sidtab = state->ss->sidtab;
1166
1167         scontext = sidtab_search(sidtab, ssid);
1168         if (!scontext) {
1169                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1170                        __func__, ssid);
1171                 goto out;
1172         }
1173
1174         /* permissive domain? */
1175         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1176                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1177
1178         tcontext = sidtab_search(sidtab, tsid);
1179         if (!tcontext) {
1180                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1181                        __func__, tsid);
1182                 goto out;
1183         }
1184
1185         if (unlikely(!tclass)) {
1186                 if (policydb->allow_unknown)
1187                         goto allow;
1188                 goto out;
1189         }
1190
1191         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1192                                   NULL);
1193  out:
1194         read_unlock(&state->ss->policy_rwlock);
1195         return;
1196 allow:
1197         avd->allowed = 0xffffffff;
1198         goto out;
1199 }
1200
1201 /*
1202  * Write the security context string representation of
1203  * the context structure `context' into a dynamically
1204  * allocated string of the correct size.  Set `*scontext'
1205  * to point to this string and set `*scontext_len' to
1206  * the length of the string.
1207  */
1208 static int context_struct_to_string(struct policydb *p,
1209                                     struct context *context,
1210                                     char **scontext, u32 *scontext_len)
1211 {
1212         char *scontextp;
1213
1214         if (scontext)
1215                 *scontext = NULL;
1216         *scontext_len = 0;
1217
1218         if (context->len) {
1219                 *scontext_len = context->len;
1220                 if (scontext) {
1221                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1222                         if (!(*scontext))
1223                                 return -ENOMEM;
1224                 }
1225                 return 0;
1226         }
1227
1228         /* Compute the size of the context. */
1229         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1230         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1231         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1232         *scontext_len += mls_compute_context_len(p, context);
1233
1234         if (!scontext)
1235                 return 0;
1236
1237         /* Allocate space for the context; caller must free this space. */
1238         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1239         if (!scontextp)
1240                 return -ENOMEM;
1241         *scontext = scontextp;
1242
1243         /*
1244          * Copy the user name, role name and type name into the context.
1245          */
1246         scontextp += sprintf(scontextp, "%s:%s:%s",
1247                 sym_name(p, SYM_USERS, context->user - 1),
1248                 sym_name(p, SYM_ROLES, context->role - 1),
1249                 sym_name(p, SYM_TYPES, context->type - 1));
1250
1251         mls_sid_to_context(p, context, &scontextp);
1252
1253         *scontextp = 0;
1254
1255         return 0;
1256 }
1257
1258 #include "initial_sid_to_string.h"
1259
1260 const char *security_get_initial_sid_context(u32 sid)
1261 {
1262         if (unlikely(sid > SECINITSID_NUM))
1263                 return NULL;
1264         return initial_sid_to_string[sid];
1265 }
1266
1267 static int security_sid_to_context_core(struct selinux_state *state,
1268                                         u32 sid, char **scontext,
1269                                         u32 *scontext_len, int force,
1270                                         int only_invalid)
1271 {
1272         struct policydb *policydb;
1273         struct sidtab *sidtab;
1274         struct context *context;
1275         int rc = 0;
1276
1277         if (scontext)
1278                 *scontext = NULL;
1279         *scontext_len  = 0;
1280
1281         if (!state->initialized) {
1282                 if (sid <= SECINITSID_NUM) {
1283                         char *scontextp;
1284
1285                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1286                         if (!scontext)
1287                                 goto out;
1288                         scontextp = kmemdup(initial_sid_to_string[sid],
1289                                             *scontext_len, GFP_ATOMIC);
1290                         if (!scontextp) {
1291                                 rc = -ENOMEM;
1292                                 goto out;
1293                         }
1294                         *scontext = scontextp;
1295                         goto out;
1296                 }
1297                 pr_err("SELinux: %s:  called before initial "
1298                        "load_policy on unknown SID %d\n", __func__, sid);
1299                 rc = -EINVAL;
1300                 goto out;
1301         }
1302         read_lock(&state->ss->policy_rwlock);
1303         policydb = &state->ss->policydb;
1304         sidtab = state->ss->sidtab;
1305         if (force)
1306                 context = sidtab_search_force(sidtab, sid);
1307         else
1308                 context = sidtab_search(sidtab, sid);
1309         if (!context) {
1310                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1311                         __func__, sid);
1312                 rc = -EINVAL;
1313                 goto out_unlock;
1314         }
1315         if (only_invalid && !context->len)
1316                 rc = 0;
1317         else
1318                 rc = context_struct_to_string(policydb, context, scontext,
1319                                               scontext_len);
1320 out_unlock:
1321         read_unlock(&state->ss->policy_rwlock);
1322 out:
1323         return rc;
1324
1325 }
1326
1327 /**
1328  * security_sid_to_context - Obtain a context for a given SID.
1329  * @sid: security identifier, SID
1330  * @scontext: security context
1331  * @scontext_len: length in bytes
1332  *
1333  * Write the string representation of the context associated with @sid
1334  * into a dynamically allocated string of the correct size.  Set @scontext
1335  * to point to this string and set @scontext_len to the length of the string.
1336  */
1337 int security_sid_to_context(struct selinux_state *state,
1338                             u32 sid, char **scontext, u32 *scontext_len)
1339 {
1340         return security_sid_to_context_core(state, sid, scontext,
1341                                             scontext_len, 0, 0);
1342 }
1343
1344 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1345                                   char **scontext, u32 *scontext_len)
1346 {
1347         return security_sid_to_context_core(state, sid, scontext,
1348                                             scontext_len, 1, 0);
1349 }
1350
1351 /**
1352  * security_sid_to_context_inval - Obtain a context for a given SID if it
1353  *                                 is invalid.
1354  * @sid: security identifier, SID
1355  * @scontext: security context
1356  * @scontext_len: length in bytes
1357  *
1358  * Write the string representation of the context associated with @sid
1359  * into a dynamically allocated string of the correct size, but only if the
1360  * context is invalid in the current policy.  Set @scontext to point to
1361  * this string (or NULL if the context is valid) and set @scontext_len to
1362  * the length of the string (or 0 if the context is valid).
1363  */
1364 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1365                                   char **scontext, u32 *scontext_len)
1366 {
1367         return security_sid_to_context_core(state, sid, scontext,
1368                                             scontext_len, 1, 1);
1369 }
1370
1371 /*
1372  * Caveat:  Mutates scontext.
1373  */
1374 static int string_to_context_struct(struct policydb *pol,
1375                                     struct sidtab *sidtabp,
1376                                     char *scontext,
1377                                     struct context *ctx,
1378                                     u32 def_sid)
1379 {
1380         struct role_datum *role;
1381         struct type_datum *typdatum;
1382         struct user_datum *usrdatum;
1383         char *scontextp, *p, oldc;
1384         int rc = 0;
1385
1386         context_init(ctx);
1387
1388         /* Parse the security context. */
1389
1390         rc = -EINVAL;
1391         scontextp = (char *) scontext;
1392
1393         /* Extract the user. */
1394         p = scontextp;
1395         while (*p && *p != ':')
1396                 p++;
1397
1398         if (*p == 0)
1399                 goto out;
1400
1401         *p++ = 0;
1402
1403         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1404         if (!usrdatum)
1405                 goto out;
1406
1407         ctx->user = usrdatum->value;
1408
1409         /* Extract role. */
1410         scontextp = p;
1411         while (*p && *p != ':')
1412                 p++;
1413
1414         if (*p == 0)
1415                 goto out;
1416
1417         *p++ = 0;
1418
1419         role = hashtab_search(pol->p_roles.table, scontextp);
1420         if (!role)
1421                 goto out;
1422         ctx->role = role->value;
1423
1424         /* Extract type. */
1425         scontextp = p;
1426         while (*p && *p != ':')
1427                 p++;
1428         oldc = *p;
1429         *p++ = 0;
1430
1431         typdatum = hashtab_search(pol->p_types.table, scontextp);
1432         if (!typdatum || typdatum->attribute)
1433                 goto out;
1434
1435         ctx->type = typdatum->value;
1436
1437         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1438         if (rc)
1439                 goto out;
1440
1441         /* Check the validity of the new context. */
1442         rc = -EINVAL;
1443         if (!policydb_context_isvalid(pol, ctx))
1444                 goto out;
1445         rc = 0;
1446 out:
1447         if (rc)
1448                 context_destroy(ctx);
1449         return rc;
1450 }
1451
1452 static int security_context_to_sid_core(struct selinux_state *state,
1453                                         const char *scontext, u32 scontext_len,
1454                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1455                                         int force)
1456 {
1457         struct policydb *policydb;
1458         struct sidtab *sidtab;
1459         char *scontext2, *str = NULL;
1460         struct context context;
1461         int rc = 0;
1462
1463         /* An empty security context is never valid. */
1464         if (!scontext_len)
1465                 return -EINVAL;
1466
1467         /* Copy the string to allow changes and ensure a NUL terminator */
1468         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1469         if (!scontext2)
1470                 return -ENOMEM;
1471
1472         if (!state->initialized) {
1473                 int i;
1474
1475                 for (i = 1; i < SECINITSID_NUM; i++) {
1476                         if (!strcmp(initial_sid_to_string[i], scontext2)) {
1477                                 *sid = i;
1478                                 goto out;
1479                         }
1480                 }
1481                 *sid = SECINITSID_KERNEL;
1482                 goto out;
1483         }
1484         *sid = SECSID_NULL;
1485
1486         if (force) {
1487                 /* Save another copy for storing in uninterpreted form */
1488                 rc = -ENOMEM;
1489                 str = kstrdup(scontext2, gfp_flags);
1490                 if (!str)
1491                         goto out;
1492         }
1493         read_lock(&state->ss->policy_rwlock);
1494         policydb = &state->ss->policydb;
1495         sidtab = state->ss->sidtab;
1496         rc = string_to_context_struct(policydb, sidtab, scontext2,
1497                                       &context, def_sid);
1498         if (rc == -EINVAL && force) {
1499                 context.str = str;
1500                 context.len = strlen(str) + 1;
1501                 str = NULL;
1502         } else if (rc)
1503                 goto out_unlock;
1504         rc = sidtab_context_to_sid(sidtab, &context, sid);
1505         context_destroy(&context);
1506 out_unlock:
1507         read_unlock(&state->ss->policy_rwlock);
1508 out:
1509         kfree(scontext2);
1510         kfree(str);
1511         return rc;
1512 }
1513
1514 /**
1515  * security_context_to_sid - Obtain a SID for a given security context.
1516  * @scontext: security context
1517  * @scontext_len: length in bytes
1518  * @sid: security identifier, SID
1519  * @gfp: context for the allocation
1520  *
1521  * Obtains a SID associated with the security context that
1522  * has the string representation specified by @scontext.
1523  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1524  * memory is available, or 0 on success.
1525  */
1526 int security_context_to_sid(struct selinux_state *state,
1527                             const char *scontext, u32 scontext_len, u32 *sid,
1528                             gfp_t gfp)
1529 {
1530         return security_context_to_sid_core(state, scontext, scontext_len,
1531                                             sid, SECSID_NULL, gfp, 0);
1532 }
1533
1534 int security_context_str_to_sid(struct selinux_state *state,
1535                                 const char *scontext, u32 *sid, gfp_t gfp)
1536 {
1537         return security_context_to_sid(state, scontext, strlen(scontext),
1538                                        sid, gfp);
1539 }
1540
1541 /**
1542  * security_context_to_sid_default - Obtain a SID for a given security context,
1543  * falling back to specified default if needed.
1544  *
1545  * @scontext: security context
1546  * @scontext_len: length in bytes
1547  * @sid: security identifier, SID
1548  * @def_sid: default SID to assign on error
1549  *
1550  * Obtains a SID associated with the security context that
1551  * has the string representation specified by @scontext.
1552  * The default SID is passed to the MLS layer to be used to allow
1553  * kernel labeling of the MLS field if the MLS field is not present
1554  * (for upgrading to MLS without full relabel).
1555  * Implicitly forces adding of the context even if it cannot be mapped yet.
1556  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1557  * memory is available, or 0 on success.
1558  */
1559 int security_context_to_sid_default(struct selinux_state *state,
1560                                     const char *scontext, u32 scontext_len,
1561                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1562 {
1563         return security_context_to_sid_core(state, scontext, scontext_len,
1564                                             sid, def_sid, gfp_flags, 1);
1565 }
1566
1567 int security_context_to_sid_force(struct selinux_state *state,
1568                                   const char *scontext, u32 scontext_len,
1569                                   u32 *sid)
1570 {
1571         return security_context_to_sid_core(state, scontext, scontext_len,
1572                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1573 }
1574
1575 static int compute_sid_handle_invalid_context(
1576         struct selinux_state *state,
1577         struct context *scontext,
1578         struct context *tcontext,
1579         u16 tclass,
1580         struct context *newcontext)
1581 {
1582         struct policydb *policydb = &state->ss->policydb;
1583         char *s = NULL, *t = NULL, *n = NULL;
1584         u32 slen, tlen, nlen;
1585         struct audit_buffer *ab;
1586
1587         if (context_struct_to_string(policydb, scontext, &s, &slen))
1588                 goto out;
1589         if (context_struct_to_string(policydb, tcontext, &t, &tlen))
1590                 goto out;
1591         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1592                 goto out;
1593         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1594         audit_log_format(ab,
1595                          "op=security_compute_sid invalid_context=");
1596         /* no need to record the NUL with untrusted strings */
1597         audit_log_n_untrustedstring(ab, n, nlen - 1);
1598         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1599                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1600         audit_log_end(ab);
1601 out:
1602         kfree(s);
1603         kfree(t);
1604         kfree(n);
1605         if (!enforcing_enabled(state))
1606                 return 0;
1607         return -EACCES;
1608 }
1609
1610 static void filename_compute_type(struct policydb *policydb,
1611                                   struct context *newcontext,
1612                                   u32 stype, u32 ttype, u16 tclass,
1613                                   const char *objname)
1614 {
1615         struct filename_trans ft;
1616         struct filename_trans_datum *otype;
1617
1618         /*
1619          * Most filename trans rules are going to live in specific directories
1620          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1621          * if the ttype does not contain any rules.
1622          */
1623         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1624                 return;
1625
1626         ft.stype = stype;
1627         ft.ttype = ttype;
1628         ft.tclass = tclass;
1629         ft.name = objname;
1630
1631         otype = hashtab_search(policydb->filename_trans, &ft);
1632         if (otype)
1633                 newcontext->type = otype->otype;
1634 }
1635
1636 static int security_compute_sid(struct selinux_state *state,
1637                                 u32 ssid,
1638                                 u32 tsid,
1639                                 u16 orig_tclass,
1640                                 u32 specified,
1641                                 const char *objname,
1642                                 u32 *out_sid,
1643                                 bool kern)
1644 {
1645         struct policydb *policydb;
1646         struct sidtab *sidtab;
1647         struct class_datum *cladatum = NULL;
1648         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1649         struct role_trans *roletr = NULL;
1650         struct avtab_key avkey;
1651         struct avtab_datum *avdatum;
1652         struct avtab_node *node;
1653         u16 tclass;
1654         int rc = 0;
1655         bool sock;
1656
1657         if (!state->initialized) {
1658                 switch (orig_tclass) {
1659                 case SECCLASS_PROCESS: /* kernel value */
1660                         *out_sid = ssid;
1661                         break;
1662                 default:
1663                         *out_sid = tsid;
1664                         break;
1665                 }
1666                 goto out;
1667         }
1668
1669         context_init(&newcontext);
1670
1671         read_lock(&state->ss->policy_rwlock);
1672
1673         if (kern) {
1674                 tclass = unmap_class(&state->ss->map, orig_tclass);
1675                 sock = security_is_socket_class(orig_tclass);
1676         } else {
1677                 tclass = orig_tclass;
1678                 sock = security_is_socket_class(map_class(&state->ss->map,
1679                                                           tclass));
1680         }
1681
1682         policydb = &state->ss->policydb;
1683         sidtab = state->ss->sidtab;
1684
1685         scontext = sidtab_search(sidtab, ssid);
1686         if (!scontext) {
1687                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1688                        __func__, ssid);
1689                 rc = -EINVAL;
1690                 goto out_unlock;
1691         }
1692         tcontext = sidtab_search(sidtab, tsid);
1693         if (!tcontext) {
1694                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1695                        __func__, tsid);
1696                 rc = -EINVAL;
1697                 goto out_unlock;
1698         }
1699
1700         if (tclass && tclass <= policydb->p_classes.nprim)
1701                 cladatum = policydb->class_val_to_struct[tclass - 1];
1702
1703         /* Set the user identity. */
1704         switch (specified) {
1705         case AVTAB_TRANSITION:
1706         case AVTAB_CHANGE:
1707                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1708                         newcontext.user = tcontext->user;
1709                 } else {
1710                         /* notice this gets both DEFAULT_SOURCE and unset */
1711                         /* Use the process user identity. */
1712                         newcontext.user = scontext->user;
1713                 }
1714                 break;
1715         case AVTAB_MEMBER:
1716                 /* Use the related object owner. */
1717                 newcontext.user = tcontext->user;
1718                 break;
1719         }
1720
1721         /* Set the role to default values. */
1722         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1723                 newcontext.role = scontext->role;
1724         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1725                 newcontext.role = tcontext->role;
1726         } else {
1727                 if ((tclass == policydb->process_class) || (sock == true))
1728                         newcontext.role = scontext->role;
1729                 else
1730                         newcontext.role = OBJECT_R_VAL;
1731         }
1732
1733         /* Set the type to default values. */
1734         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1735                 newcontext.type = scontext->type;
1736         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1737                 newcontext.type = tcontext->type;
1738         } else {
1739                 if ((tclass == policydb->process_class) || (sock == true)) {
1740                         /* Use the type of process. */
1741                         newcontext.type = scontext->type;
1742                 } else {
1743                         /* Use the type of the related object. */
1744                         newcontext.type = tcontext->type;
1745                 }
1746         }
1747
1748         /* Look for a type transition/member/change rule. */
1749         avkey.source_type = scontext->type;
1750         avkey.target_type = tcontext->type;
1751         avkey.target_class = tclass;
1752         avkey.specified = specified;
1753         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1754
1755         /* If no permanent rule, also check for enabled conditional rules */
1756         if (!avdatum) {
1757                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1758                 for (; node; node = avtab_search_node_next(node, specified)) {
1759                         if (node->key.specified & AVTAB_ENABLED) {
1760                                 avdatum = &node->datum;
1761                                 break;
1762                         }
1763                 }
1764         }
1765
1766         if (avdatum) {
1767                 /* Use the type from the type transition/member/change rule. */
1768                 newcontext.type = avdatum->u.data;
1769         }
1770
1771         /* if we have a objname this is a file trans check so check those rules */
1772         if (objname)
1773                 filename_compute_type(policydb, &newcontext, scontext->type,
1774                                       tcontext->type, tclass, objname);
1775
1776         /* Check for class-specific changes. */
1777         if (specified & AVTAB_TRANSITION) {
1778                 /* Look for a role transition rule. */
1779                 for (roletr = policydb->role_tr; roletr;
1780                      roletr = roletr->next) {
1781                         if ((roletr->role == scontext->role) &&
1782                             (roletr->type == tcontext->type) &&
1783                             (roletr->tclass == tclass)) {
1784                                 /* Use the role transition rule. */
1785                                 newcontext.role = roletr->new_role;
1786                                 break;
1787                         }
1788                 }
1789         }
1790
1791         /* Set the MLS attributes.
1792            This is done last because it may allocate memory. */
1793         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1794                              &newcontext, sock);
1795         if (rc)
1796                 goto out_unlock;
1797
1798         /* Check the validity of the context. */
1799         if (!policydb_context_isvalid(policydb, &newcontext)) {
1800                 rc = compute_sid_handle_invalid_context(state, scontext,
1801                                                         tcontext,
1802                                                         tclass,
1803                                                         &newcontext);
1804                 if (rc)
1805                         goto out_unlock;
1806         }
1807         /* Obtain the sid for the context. */
1808         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1809 out_unlock:
1810         read_unlock(&state->ss->policy_rwlock);
1811         context_destroy(&newcontext);
1812 out:
1813         return rc;
1814 }
1815
1816 /**
1817  * security_transition_sid - Compute the SID for a new subject/object.
1818  * @ssid: source security identifier
1819  * @tsid: target security identifier
1820  * @tclass: target security class
1821  * @out_sid: security identifier for new subject/object
1822  *
1823  * Compute a SID to use for labeling a new subject or object in the
1824  * class @tclass based on a SID pair (@ssid, @tsid).
1825  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1826  * if insufficient memory is available, or %0 if the new SID was
1827  * computed successfully.
1828  */
1829 int security_transition_sid(struct selinux_state *state,
1830                             u32 ssid, u32 tsid, u16 tclass,
1831                             const struct qstr *qstr, u32 *out_sid)
1832 {
1833         return security_compute_sid(state, ssid, tsid, tclass,
1834                                     AVTAB_TRANSITION,
1835                                     qstr ? qstr->name : NULL, out_sid, true);
1836 }
1837
1838 int security_transition_sid_user(struct selinux_state *state,
1839                                  u32 ssid, u32 tsid, u16 tclass,
1840                                  const char *objname, u32 *out_sid)
1841 {
1842         return security_compute_sid(state, ssid, tsid, tclass,
1843                                     AVTAB_TRANSITION,
1844                                     objname, out_sid, false);
1845 }
1846
1847 /**
1848  * security_member_sid - Compute the SID for member selection.
1849  * @ssid: source security identifier
1850  * @tsid: target security identifier
1851  * @tclass: target security class
1852  * @out_sid: security identifier for selected member
1853  *
1854  * Compute a SID to use when selecting a member of a polyinstantiated
1855  * object of class @tclass based on a SID pair (@ssid, @tsid).
1856  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1857  * if insufficient memory is available, or %0 if the SID was
1858  * computed successfully.
1859  */
1860 int security_member_sid(struct selinux_state *state,
1861                         u32 ssid,
1862                         u32 tsid,
1863                         u16 tclass,
1864                         u32 *out_sid)
1865 {
1866         return security_compute_sid(state, ssid, tsid, tclass,
1867                                     AVTAB_MEMBER, NULL,
1868                                     out_sid, false);
1869 }
1870
1871 /**
1872  * security_change_sid - Compute the SID for object relabeling.
1873  * @ssid: source security identifier
1874  * @tsid: target security identifier
1875  * @tclass: target security class
1876  * @out_sid: security identifier for selected member
1877  *
1878  * Compute a SID to use for relabeling an object of class @tclass
1879  * based on a SID pair (@ssid, @tsid).
1880  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1881  * if insufficient memory is available, or %0 if the SID was
1882  * computed successfully.
1883  */
1884 int security_change_sid(struct selinux_state *state,
1885                         u32 ssid,
1886                         u32 tsid,
1887                         u16 tclass,
1888                         u32 *out_sid)
1889 {
1890         return security_compute_sid(state,
1891                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1892                                     out_sid, false);
1893 }
1894
1895 static inline int convert_context_handle_invalid_context(
1896         struct selinux_state *state,
1897         struct context *context)
1898 {
1899         struct policydb *policydb = &state->ss->policydb;
1900         char *s;
1901         u32 len;
1902
1903         if (enforcing_enabled(state))
1904                 return -EINVAL;
1905
1906         if (!context_struct_to_string(policydb, context, &s, &len)) {
1907                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
1908                         s);
1909                 kfree(s);
1910         }
1911         return 0;
1912 }
1913
1914 struct convert_context_args {
1915         struct selinux_state *state;
1916         struct policydb *oldp;
1917         struct policydb *newp;
1918 };
1919
1920 /*
1921  * Convert the values in the security context
1922  * structure `oldc' from the values specified
1923  * in the policy `p->oldp' to the values specified
1924  * in the policy `p->newp', storing the new context
1925  * in `newc'.  Verify that the context is valid
1926  * under the new policy.
1927  */
1928 static int convert_context(struct context *oldc, struct context *newc, void *p)
1929 {
1930         struct convert_context_args *args;
1931         struct ocontext *oc;
1932         struct role_datum *role;
1933         struct type_datum *typdatum;
1934         struct user_datum *usrdatum;
1935         char *s;
1936         u32 len;
1937         int rc;
1938
1939         args = p;
1940
1941         if (oldc->str) {
1942                 s = kstrdup(oldc->str, GFP_KERNEL);
1943                 if (!s)
1944                         return -ENOMEM;
1945
1946                 rc = string_to_context_struct(args->newp, NULL, s,
1947                                               newc, SECSID_NULL);
1948                 if (rc == -EINVAL) {
1949                         /* Retain string representation for later mapping. */
1950                         context_init(newc);
1951                         newc->str = s;
1952                         newc->len = oldc->len;
1953                         return 0;
1954                 }
1955                 kfree(s);
1956                 if (rc) {
1957                         /* Other error condition, e.g. ENOMEM. */
1958                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
1959                                oldc->str, -rc);
1960                         return rc;
1961                 }
1962                 pr_info("SELinux:  Context %s became valid (mapped).\n",
1963                         oldc->str);
1964                 return 0;
1965         }
1966
1967         context_init(newc);
1968
1969         /* Convert the user. */
1970         rc = -EINVAL;
1971         usrdatum = hashtab_search(args->newp->p_users.table,
1972                                   sym_name(args->oldp,
1973                                            SYM_USERS, oldc->user - 1));
1974         if (!usrdatum)
1975                 goto bad;
1976         newc->user = usrdatum->value;
1977
1978         /* Convert the role. */
1979         rc = -EINVAL;
1980         role = hashtab_search(args->newp->p_roles.table,
1981                               sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
1982         if (!role)
1983                 goto bad;
1984         newc->role = role->value;
1985
1986         /* Convert the type. */
1987         rc = -EINVAL;
1988         typdatum = hashtab_search(args->newp->p_types.table,
1989                                   sym_name(args->oldp,
1990                                            SYM_TYPES, oldc->type - 1));
1991         if (!typdatum)
1992                 goto bad;
1993         newc->type = typdatum->value;
1994
1995         /* Convert the MLS fields if dealing with MLS policies */
1996         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1997                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
1998                 if (rc)
1999                         goto bad;
2000         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2001                 /*
2002                  * Switching between non-MLS and MLS policy:
2003                  * ensure that the MLS fields of the context for all
2004                  * existing entries in the sidtab are filled in with a
2005                  * suitable default value, likely taken from one of the
2006                  * initial SIDs.
2007                  */
2008                 oc = args->newp->ocontexts[OCON_ISID];
2009                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2010                         oc = oc->next;
2011                 rc = -EINVAL;
2012                 if (!oc) {
2013                         pr_err("SELinux:  unable to look up"
2014                                 " the initial SIDs list\n");
2015                         goto bad;
2016                 }
2017                 rc = mls_range_set(newc, &oc->context[0].range);
2018                 if (rc)
2019                         goto bad;
2020         }
2021
2022         /* Check the validity of the new context. */
2023         if (!policydb_context_isvalid(args->newp, newc)) {
2024                 rc = convert_context_handle_invalid_context(args->state, oldc);
2025                 if (rc)
2026                         goto bad;
2027         }
2028
2029         return 0;
2030 bad:
2031         /* Map old representation to string and save it. */
2032         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2033         if (rc)
2034                 return rc;
2035         context_destroy(newc);
2036         newc->str = s;
2037         newc->len = len;
2038         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2039                 newc->str);
2040         return 0;
2041 }
2042
2043 static void security_load_policycaps(struct selinux_state *state)
2044 {
2045         struct policydb *p = &state->ss->policydb;
2046         unsigned int i;
2047         struct ebitmap_node *node;
2048
2049         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2050                 state->policycap[i] = ebitmap_get_bit(&p->policycaps, i);
2051
2052         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2053                 pr_info("SELinux:  policy capability %s=%d\n",
2054                         selinux_policycap_names[i],
2055                         ebitmap_get_bit(&p->policycaps, i));
2056
2057         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2058                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2059                         pr_info("SELinux:  unknown policy capability %u\n",
2060                                 i);
2061         }
2062 }
2063
2064 static int security_preserve_bools(struct selinux_state *state,
2065                                    struct policydb *newpolicydb);
2066
2067 /**
2068  * security_load_policy - Load a security policy configuration.
2069  * @data: binary policy data
2070  * @len: length of data in bytes
2071  *
2072  * Load a new set of security policy configuration data,
2073  * validate it and convert the SID table as necessary.
2074  * This function will flush the access vector cache after
2075  * loading the new policy.
2076  */
2077 int security_load_policy(struct selinux_state *state, void *data, size_t len)
2078 {
2079         struct policydb *policydb;
2080         struct sidtab *oldsidtab, *newsidtab;
2081         struct policydb *oldpolicydb, *newpolicydb;
2082         struct selinux_mapping *oldmapping;
2083         struct selinux_map newmap;
2084         struct sidtab_convert_params convert_params;
2085         struct convert_context_args args;
2086         u32 seqno;
2087         int rc = 0;
2088         struct policy_file file = { data, len }, *fp = &file;
2089
2090         oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL);
2091         if (!oldpolicydb) {
2092                 rc = -ENOMEM;
2093                 goto out;
2094         }
2095         newpolicydb = oldpolicydb + 1;
2096
2097         policydb = &state->ss->policydb;
2098
2099         newsidtab = kmalloc(sizeof(*newsidtab), GFP_KERNEL);
2100         if (!newsidtab) {
2101                 rc = -ENOMEM;
2102                 goto out;
2103         }
2104
2105         if (!state->initialized) {
2106                 rc = policydb_read(policydb, fp);
2107                 if (rc) {
2108                         kfree(newsidtab);
2109                         goto out;
2110                 }
2111
2112                 policydb->len = len;
2113                 rc = selinux_set_mapping(policydb, secclass_map,
2114                                          &state->ss->map);
2115                 if (rc) {
2116                         kfree(newsidtab);
2117                         policydb_destroy(policydb);
2118                         goto out;
2119                 }
2120
2121                 rc = policydb_load_isids(policydb, newsidtab);
2122                 if (rc) {
2123                         kfree(newsidtab);
2124                         policydb_destroy(policydb);
2125                         goto out;
2126                 }
2127
2128                 state->ss->sidtab = newsidtab;
2129                 security_load_policycaps(state);
2130                 state->initialized = 1;
2131                 seqno = ++state->ss->latest_granting;
2132                 selinux_complete_init();
2133                 avc_ss_reset(state->avc, seqno);
2134                 selnl_notify_policyload(seqno);
2135                 selinux_status_update_policyload(state, seqno);
2136                 selinux_netlbl_cache_invalidate();
2137                 selinux_xfrm_notify_policyload();
2138                 goto out;
2139         }
2140
2141         rc = policydb_read(newpolicydb, fp);
2142         if (rc) {
2143                 kfree(newsidtab);
2144                 goto out;
2145         }
2146
2147         newpolicydb->len = len;
2148         /* If switching between different policy types, log MLS status */
2149         if (policydb->mls_enabled && !newpolicydb->mls_enabled)
2150                 pr_info("SELinux: Disabling MLS support...\n");
2151         else if (!policydb->mls_enabled && newpolicydb->mls_enabled)
2152                 pr_info("SELinux: Enabling MLS support...\n");
2153
2154         rc = policydb_load_isids(newpolicydb, newsidtab);
2155         if (rc) {
2156                 pr_err("SELinux:  unable to load the initial SIDs\n");
2157                 policydb_destroy(newpolicydb);
2158                 kfree(newsidtab);
2159                 goto out;
2160         }
2161
2162         rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap);
2163         if (rc)
2164                 goto err;
2165
2166         rc = security_preserve_bools(state, newpolicydb);
2167         if (rc) {
2168                 pr_err("SELinux:  unable to preserve booleans\n");
2169                 goto err;
2170         }
2171
2172         oldsidtab = state->ss->sidtab;
2173
2174         /*
2175          * Convert the internal representations of contexts
2176          * in the new SID table.
2177          */
2178         args.state = state;
2179         args.oldp = policydb;
2180         args.newp = newpolicydb;
2181
2182         convert_params.func = convert_context;
2183         convert_params.args = &args;
2184         convert_params.target = newsidtab;
2185
2186         rc = sidtab_convert(oldsidtab, &convert_params);
2187         if (rc) {
2188                 pr_err("SELinux:  unable to convert the internal"
2189                         " representation of contexts in the new SID"
2190                         " table\n");
2191                 goto err;
2192         }
2193
2194         /* Save the old policydb and SID table to free later. */
2195         memcpy(oldpolicydb, policydb, sizeof(*policydb));
2196
2197         /* Install the new policydb and SID table. */
2198         write_lock_irq(&state->ss->policy_rwlock);
2199         memcpy(policydb, newpolicydb, sizeof(*policydb));
2200         state->ss->sidtab = newsidtab;
2201         security_load_policycaps(state);
2202         oldmapping = state->ss->map.mapping;
2203         state->ss->map.mapping = newmap.mapping;
2204         state->ss->map.size = newmap.size;
2205         seqno = ++state->ss->latest_granting;
2206         write_unlock_irq(&state->ss->policy_rwlock);
2207
2208         /* Free the old policydb and SID table. */
2209         policydb_destroy(oldpolicydb);
2210         sidtab_destroy(oldsidtab);
2211         kfree(oldsidtab);
2212         kfree(oldmapping);
2213
2214         avc_ss_reset(state->avc, seqno);
2215         selnl_notify_policyload(seqno);
2216         selinux_status_update_policyload(state, seqno);
2217         selinux_netlbl_cache_invalidate();
2218         selinux_xfrm_notify_policyload();
2219
2220         rc = 0;
2221         goto out;
2222
2223 err:
2224         kfree(newmap.mapping);
2225         sidtab_destroy(newsidtab);
2226         kfree(newsidtab);
2227         policydb_destroy(newpolicydb);
2228
2229 out:
2230         kfree(oldpolicydb);
2231         return rc;
2232 }
2233
2234 size_t security_policydb_len(struct selinux_state *state)
2235 {
2236         struct policydb *p = &state->ss->policydb;
2237         size_t len;
2238
2239         read_lock(&state->ss->policy_rwlock);
2240         len = p->len;
2241         read_unlock(&state->ss->policy_rwlock);
2242
2243         return len;
2244 }
2245
2246 /**
2247  * security_port_sid - Obtain the SID for a port.
2248  * @protocol: protocol number
2249  * @port: port number
2250  * @out_sid: security identifier
2251  */
2252 int security_port_sid(struct selinux_state *state,
2253                       u8 protocol, u16 port, u32 *out_sid)
2254 {
2255         struct policydb *policydb;
2256         struct sidtab *sidtab;
2257         struct ocontext *c;
2258         int rc = 0;
2259
2260         read_lock(&state->ss->policy_rwlock);
2261
2262         policydb = &state->ss->policydb;
2263         sidtab = state->ss->sidtab;
2264
2265         c = policydb->ocontexts[OCON_PORT];
2266         while (c) {
2267                 if (c->u.port.protocol == protocol &&
2268                     c->u.port.low_port <= port &&
2269                     c->u.port.high_port >= port)
2270                         break;
2271                 c = c->next;
2272         }
2273
2274         if (c) {
2275                 if (!c->sid[0]) {
2276                         rc = sidtab_context_to_sid(sidtab,
2277                                                    &c->context[0],
2278                                                    &c->sid[0]);
2279                         if (rc)
2280                                 goto out;
2281                 }
2282                 *out_sid = c->sid[0];
2283         } else {
2284                 *out_sid = SECINITSID_PORT;
2285         }
2286
2287 out:
2288         read_unlock(&state->ss->policy_rwlock);
2289         return rc;
2290 }
2291
2292 /**
2293  * security_pkey_sid - Obtain the SID for a pkey.
2294  * @subnet_prefix: Subnet Prefix
2295  * @pkey_num: pkey number
2296  * @out_sid: security identifier
2297  */
2298 int security_ib_pkey_sid(struct selinux_state *state,
2299                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2300 {
2301         struct policydb *policydb;
2302         struct sidtab *sidtab;
2303         struct ocontext *c;
2304         int rc = 0;
2305
2306         read_lock(&state->ss->policy_rwlock);
2307
2308         policydb = &state->ss->policydb;
2309         sidtab = state->ss->sidtab;
2310
2311         c = policydb->ocontexts[OCON_IBPKEY];
2312         while (c) {
2313                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2314                     c->u.ibpkey.high_pkey >= pkey_num &&
2315                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2316                         break;
2317
2318                 c = c->next;
2319         }
2320
2321         if (c) {
2322                 if (!c->sid[0]) {
2323                         rc = sidtab_context_to_sid(sidtab,
2324                                                    &c->context[0],
2325                                                    &c->sid[0]);
2326                         if (rc)
2327                                 goto out;
2328                 }
2329                 *out_sid = c->sid[0];
2330         } else
2331                 *out_sid = SECINITSID_UNLABELED;
2332
2333 out:
2334         read_unlock(&state->ss->policy_rwlock);
2335         return rc;
2336 }
2337
2338 /**
2339  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2340  * @dev_name: device name
2341  * @port: port number
2342  * @out_sid: security identifier
2343  */
2344 int security_ib_endport_sid(struct selinux_state *state,
2345                             const char *dev_name, u8 port_num, u32 *out_sid)
2346 {
2347         struct policydb *policydb;
2348         struct sidtab *sidtab;
2349         struct ocontext *c;
2350         int rc = 0;
2351
2352         read_lock(&state->ss->policy_rwlock);
2353
2354         policydb = &state->ss->policydb;
2355         sidtab = state->ss->sidtab;
2356
2357         c = policydb->ocontexts[OCON_IBENDPORT];
2358         while (c) {
2359                 if (c->u.ibendport.port == port_num &&
2360                     !strncmp(c->u.ibendport.dev_name,
2361                              dev_name,
2362                              IB_DEVICE_NAME_MAX))
2363                         break;
2364
2365                 c = c->next;
2366         }
2367
2368         if (c) {
2369                 if (!c->sid[0]) {
2370                         rc = sidtab_context_to_sid(sidtab,
2371                                                    &c->context[0],
2372                                                    &c->sid[0]);
2373                         if (rc)
2374                                 goto out;
2375                 }
2376                 *out_sid = c->sid[0];
2377         } else
2378                 *out_sid = SECINITSID_UNLABELED;
2379
2380 out:
2381         read_unlock(&state->ss->policy_rwlock);
2382         return rc;
2383 }
2384
2385 /**
2386  * security_netif_sid - Obtain the SID for a network interface.
2387  * @name: interface name
2388  * @if_sid: interface SID
2389  */
2390 int security_netif_sid(struct selinux_state *state,
2391                        char *name, u32 *if_sid)
2392 {
2393         struct policydb *policydb;
2394         struct sidtab *sidtab;
2395         int rc = 0;
2396         struct ocontext *c;
2397
2398         read_lock(&state->ss->policy_rwlock);
2399
2400         policydb = &state->ss->policydb;
2401         sidtab = state->ss->sidtab;
2402
2403         c = policydb->ocontexts[OCON_NETIF];
2404         while (c) {
2405                 if (strcmp(name, c->u.name) == 0)
2406                         break;
2407                 c = c->next;
2408         }
2409
2410         if (c) {
2411                 if (!c->sid[0] || !c->sid[1]) {
2412                         rc = sidtab_context_to_sid(sidtab,
2413                                                   &c->context[0],
2414                                                   &c->sid[0]);
2415                         if (rc)
2416                                 goto out;
2417                         rc = sidtab_context_to_sid(sidtab,
2418                                                    &c->context[1],
2419                                                    &c->sid[1]);
2420                         if (rc)
2421                                 goto out;
2422                 }
2423                 *if_sid = c->sid[0];
2424         } else
2425                 *if_sid = SECINITSID_NETIF;
2426
2427 out:
2428         read_unlock(&state->ss->policy_rwlock);
2429         return rc;
2430 }
2431
2432 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2433 {
2434         int i, fail = 0;
2435
2436         for (i = 0; i < 4; i++)
2437                 if (addr[i] != (input[i] & mask[i])) {
2438                         fail = 1;
2439                         break;
2440                 }
2441
2442         return !fail;
2443 }
2444
2445 /**
2446  * security_node_sid - Obtain the SID for a node (host).
2447  * @domain: communication domain aka address family
2448  * @addrp: address
2449  * @addrlen: address length in bytes
2450  * @out_sid: security identifier
2451  */
2452 int security_node_sid(struct selinux_state *state,
2453                       u16 domain,
2454                       void *addrp,
2455                       u32 addrlen,
2456                       u32 *out_sid)
2457 {
2458         struct policydb *policydb;
2459         struct sidtab *sidtab;
2460         int rc;
2461         struct ocontext *c;
2462
2463         read_lock(&state->ss->policy_rwlock);
2464
2465         policydb = &state->ss->policydb;
2466         sidtab = state->ss->sidtab;
2467
2468         switch (domain) {
2469         case AF_INET: {
2470                 u32 addr;
2471
2472                 rc = -EINVAL;
2473                 if (addrlen != sizeof(u32))
2474                         goto out;
2475
2476                 addr = *((u32 *)addrp);
2477
2478                 c = policydb->ocontexts[OCON_NODE];
2479                 while (c) {
2480                         if (c->u.node.addr == (addr & c->u.node.mask))
2481                                 break;
2482                         c = c->next;
2483                 }
2484                 break;
2485         }
2486
2487         case AF_INET6:
2488                 rc = -EINVAL;
2489                 if (addrlen != sizeof(u64) * 2)
2490                         goto out;
2491                 c = policydb->ocontexts[OCON_NODE6];
2492                 while (c) {
2493                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2494                                                 c->u.node6.mask))
2495                                 break;
2496                         c = c->next;
2497                 }
2498                 break;
2499
2500         default:
2501                 rc = 0;
2502                 *out_sid = SECINITSID_NODE;
2503                 goto out;
2504         }
2505
2506         if (c) {
2507                 if (!c->sid[0]) {
2508                         rc = sidtab_context_to_sid(sidtab,
2509                                                    &c->context[0],
2510                                                    &c->sid[0]);
2511                         if (rc)
2512                                 goto out;
2513                 }
2514                 *out_sid = c->sid[0];
2515         } else {
2516                 *out_sid = SECINITSID_NODE;
2517         }
2518
2519         rc = 0;
2520 out:
2521         read_unlock(&state->ss->policy_rwlock);
2522         return rc;
2523 }
2524
2525 #define SIDS_NEL 25
2526
2527 /**
2528  * security_get_user_sids - Obtain reachable SIDs for a user.
2529  * @fromsid: starting SID
2530  * @username: username
2531  * @sids: array of reachable SIDs for user
2532  * @nel: number of elements in @sids
2533  *
2534  * Generate the set of SIDs for legal security contexts
2535  * for a given user that can be reached by @fromsid.
2536  * Set *@sids to point to a dynamically allocated
2537  * array containing the set of SIDs.  Set *@nel to the
2538  * number of elements in the array.
2539  */
2540
2541 int security_get_user_sids(struct selinux_state *state,
2542                            u32 fromsid,
2543                            char *username,
2544                            u32 **sids,
2545                            u32 *nel)
2546 {
2547         struct policydb *policydb;
2548         struct sidtab *sidtab;
2549         struct context *fromcon, usercon;
2550         u32 *mysids = NULL, *mysids2, sid;
2551         u32 mynel = 0, maxnel = SIDS_NEL;
2552         struct user_datum *user;
2553         struct role_datum *role;
2554         struct ebitmap_node *rnode, *tnode;
2555         int rc = 0, i, j;
2556
2557         *sids = NULL;
2558         *nel = 0;
2559
2560         if (!state->initialized)
2561                 goto out;
2562
2563         read_lock(&state->ss->policy_rwlock);
2564
2565         policydb = &state->ss->policydb;
2566         sidtab = state->ss->sidtab;
2567
2568         context_init(&usercon);
2569
2570         rc = -EINVAL;
2571         fromcon = sidtab_search(sidtab, fromsid);
2572         if (!fromcon)
2573                 goto out_unlock;
2574
2575         rc = -EINVAL;
2576         user = hashtab_search(policydb->p_users.table, username);
2577         if (!user)
2578                 goto out_unlock;
2579
2580         usercon.user = user->value;
2581
2582         rc = -ENOMEM;
2583         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2584         if (!mysids)
2585                 goto out_unlock;
2586
2587         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2588                 role = policydb->role_val_to_struct[i];
2589                 usercon.role = i + 1;
2590                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2591                         usercon.type = j + 1;
2592
2593                         if (mls_setup_user_range(policydb, fromcon, user,
2594                                                  &usercon))
2595                                 continue;
2596
2597                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2598                         if (rc)
2599                                 goto out_unlock;
2600                         if (mynel < maxnel) {
2601                                 mysids[mynel++] = sid;
2602                         } else {
2603                                 rc = -ENOMEM;
2604                                 maxnel += SIDS_NEL;
2605                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2606                                 if (!mysids2)
2607                                         goto out_unlock;
2608                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2609                                 kfree(mysids);
2610                                 mysids = mysids2;
2611                                 mysids[mynel++] = sid;
2612                         }
2613                 }
2614         }
2615         rc = 0;
2616 out_unlock:
2617         read_unlock(&state->ss->policy_rwlock);
2618         if (rc || !mynel) {
2619                 kfree(mysids);
2620                 goto out;
2621         }
2622
2623         rc = -ENOMEM;
2624         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2625         if (!mysids2) {
2626                 kfree(mysids);
2627                 goto out;
2628         }
2629         for (i = 0, j = 0; i < mynel; i++) {
2630                 struct av_decision dummy_avd;
2631                 rc = avc_has_perm_noaudit(state,
2632                                           fromsid, mysids[i],
2633                                           SECCLASS_PROCESS, /* kernel value */
2634                                           PROCESS__TRANSITION, AVC_STRICT,
2635                                           &dummy_avd);
2636                 if (!rc)
2637                         mysids2[j++] = mysids[i];
2638                 cond_resched();
2639         }
2640         rc = 0;
2641         kfree(mysids);
2642         *sids = mysids2;
2643         *nel = j;
2644 out:
2645         return rc;
2646 }
2647
2648 /**
2649  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2650  * @fstype: filesystem type
2651  * @path: path from root of mount
2652  * @sclass: file security class
2653  * @sid: SID for path
2654  *
2655  * Obtain a SID to use for a file in a filesystem that
2656  * cannot support xattr or use a fixed labeling behavior like
2657  * transition SIDs or task SIDs.
2658  *
2659  * The caller must acquire the policy_rwlock before calling this function.
2660  */
2661 static inline int __security_genfs_sid(struct selinux_state *state,
2662                                        const char *fstype,
2663                                        char *path,
2664                                        u16 orig_sclass,
2665                                        u32 *sid)
2666 {
2667         struct policydb *policydb = &state->ss->policydb;
2668         struct sidtab *sidtab = state->ss->sidtab;
2669         int len;
2670         u16 sclass;
2671         struct genfs *genfs;
2672         struct ocontext *c;
2673         int rc, cmp = 0;
2674
2675         while (path[0] == '/' && path[1] == '/')
2676                 path++;
2677
2678         sclass = unmap_class(&state->ss->map, orig_sclass);
2679         *sid = SECINITSID_UNLABELED;
2680
2681         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2682                 cmp = strcmp(fstype, genfs->fstype);
2683                 if (cmp <= 0)
2684                         break;
2685         }
2686
2687         rc = -ENOENT;
2688         if (!genfs || cmp)
2689                 goto out;
2690
2691         for (c = genfs->head; c; c = c->next) {
2692                 len = strlen(c->u.name);
2693                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2694                     (strncmp(c->u.name, path, len) == 0))
2695                         break;
2696         }
2697
2698         rc = -ENOENT;
2699         if (!c)
2700                 goto out;
2701
2702         if (!c->sid[0]) {
2703                 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
2704                 if (rc)
2705                         goto out;
2706         }
2707
2708         *sid = c->sid[0];
2709         rc = 0;
2710 out:
2711         return rc;
2712 }
2713
2714 /**
2715  * security_genfs_sid - Obtain a SID for a file in a filesystem
2716  * @fstype: filesystem type
2717  * @path: path from root of mount
2718  * @sclass: file security class
2719  * @sid: SID for path
2720  *
2721  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2722  * it afterward.
2723  */
2724 int security_genfs_sid(struct selinux_state *state,
2725                        const char *fstype,
2726                        char *path,
2727                        u16 orig_sclass,
2728                        u32 *sid)
2729 {
2730         int retval;
2731
2732         read_lock(&state->ss->policy_rwlock);
2733         retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid);
2734         read_unlock(&state->ss->policy_rwlock);
2735         return retval;
2736 }
2737
2738 /**
2739  * security_fs_use - Determine how to handle labeling for a filesystem.
2740  * @sb: superblock in question
2741  */
2742 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2743 {
2744         struct policydb *policydb;
2745         struct sidtab *sidtab;
2746         int rc = 0;
2747         struct ocontext *c;
2748         struct superblock_security_struct *sbsec = sb->s_security;
2749         const char *fstype = sb->s_type->name;
2750
2751         read_lock(&state->ss->policy_rwlock);
2752
2753         policydb = &state->ss->policydb;
2754         sidtab = state->ss->sidtab;
2755
2756         c = policydb->ocontexts[OCON_FSUSE];
2757         while (c) {
2758                 if (strcmp(fstype, c->u.name) == 0)
2759                         break;
2760                 c = c->next;
2761         }
2762
2763         if (c) {
2764                 sbsec->behavior = c->v.behavior;
2765                 if (!c->sid[0]) {
2766                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2767                                                    &c->sid[0]);
2768                         if (rc)
2769                                 goto out;
2770                 }
2771                 sbsec->sid = c->sid[0];
2772         } else {
2773                 rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR,
2774                                           &sbsec->sid);
2775                 if (rc) {
2776                         sbsec->behavior = SECURITY_FS_USE_NONE;
2777                         rc = 0;
2778                 } else {
2779                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2780                 }
2781         }
2782
2783 out:
2784         read_unlock(&state->ss->policy_rwlock);
2785         return rc;
2786 }
2787
2788 int security_get_bools(struct selinux_state *state,
2789                        int *len, char ***names, int **values)
2790 {
2791         struct policydb *policydb;
2792         int i, rc;
2793
2794         if (!state->initialized) {
2795                 *len = 0;
2796                 *names = NULL;
2797                 *values = NULL;
2798                 return 0;
2799         }
2800
2801         read_lock(&state->ss->policy_rwlock);
2802
2803         policydb = &state->ss->policydb;
2804
2805         *names = NULL;
2806         *values = NULL;
2807
2808         rc = 0;
2809         *len = policydb->p_bools.nprim;
2810         if (!*len)
2811                 goto out;
2812
2813         rc = -ENOMEM;
2814         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2815         if (!*names)
2816                 goto err;
2817
2818         rc = -ENOMEM;
2819         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2820         if (!*values)
2821                 goto err;
2822
2823         for (i = 0; i < *len; i++) {
2824                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
2825
2826                 rc = -ENOMEM;
2827                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
2828                                       GFP_ATOMIC);
2829                 if (!(*names)[i])
2830                         goto err;
2831         }
2832         rc = 0;
2833 out:
2834         read_unlock(&state->ss->policy_rwlock);
2835         return rc;
2836 err:
2837         if (*names) {
2838                 for (i = 0; i < *len; i++)
2839                         kfree((*names)[i]);
2840         }
2841         kfree(*values);
2842         goto out;
2843 }
2844
2845
2846 int security_set_bools(struct selinux_state *state, int len, int *values)
2847 {
2848         struct policydb *policydb;
2849         int i, rc;
2850         int lenp, seqno = 0;
2851         struct cond_node *cur;
2852
2853         write_lock_irq(&state->ss->policy_rwlock);
2854
2855         policydb = &state->ss->policydb;
2856
2857         rc = -EFAULT;
2858         lenp = policydb->p_bools.nprim;
2859         if (len != lenp)
2860                 goto out;
2861
2862         for (i = 0; i < len; i++) {
2863                 if (!!values[i] != policydb->bool_val_to_struct[i]->state) {
2864                         audit_log(audit_context(), GFP_ATOMIC,
2865                                 AUDIT_MAC_CONFIG_CHANGE,
2866                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2867                                 sym_name(policydb, SYM_BOOLS, i),
2868                                 !!values[i],
2869                                 policydb->bool_val_to_struct[i]->state,
2870                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2871                                 audit_get_sessionid(current));
2872                 }
2873                 if (values[i])
2874                         policydb->bool_val_to_struct[i]->state = 1;
2875                 else
2876                         policydb->bool_val_to_struct[i]->state = 0;
2877         }
2878
2879         for (cur = policydb->cond_list; cur; cur = cur->next) {
2880                 rc = evaluate_cond_node(policydb, cur);
2881                 if (rc)
2882                         goto out;
2883         }
2884
2885         seqno = ++state->ss->latest_granting;
2886         rc = 0;
2887 out:
2888         write_unlock_irq(&state->ss->policy_rwlock);
2889         if (!rc) {
2890                 avc_ss_reset(state->avc, seqno);
2891                 selnl_notify_policyload(seqno);
2892                 selinux_status_update_policyload(state, seqno);
2893                 selinux_xfrm_notify_policyload();
2894         }
2895         return rc;
2896 }
2897
2898 int security_get_bool_value(struct selinux_state *state,
2899                             int index)
2900 {
2901         struct policydb *policydb;
2902         int rc;
2903         int len;
2904
2905         read_lock(&state->ss->policy_rwlock);
2906
2907         policydb = &state->ss->policydb;
2908
2909         rc = -EFAULT;
2910         len = policydb->p_bools.nprim;
2911         if (index >= len)
2912                 goto out;
2913
2914         rc = policydb->bool_val_to_struct[index]->state;
2915 out:
2916         read_unlock(&state->ss->policy_rwlock);
2917         return rc;
2918 }
2919
2920 static int security_preserve_bools(struct selinux_state *state,
2921                                    struct policydb *policydb)
2922 {
2923         int rc, nbools = 0, *bvalues = NULL, i;
2924         char **bnames = NULL;
2925         struct cond_bool_datum *booldatum;
2926         struct cond_node *cur;
2927
2928         rc = security_get_bools(state, &nbools, &bnames, &bvalues);
2929         if (rc)
2930                 goto out;
2931         for (i = 0; i < nbools; i++) {
2932                 booldatum = hashtab_search(policydb->p_bools.table, bnames[i]);
2933                 if (booldatum)
2934                         booldatum->state = bvalues[i];
2935         }
2936         for (cur = policydb->cond_list; cur; cur = cur->next) {
2937                 rc = evaluate_cond_node(policydb, cur);
2938                 if (rc)
2939                         goto out;
2940         }
2941
2942 out:
2943         if (bnames) {
2944                 for (i = 0; i < nbools; i++)
2945                         kfree(bnames[i]);
2946         }
2947         kfree(bnames);
2948         kfree(bvalues);
2949         return rc;
2950 }
2951
2952 /*
2953  * security_sid_mls_copy() - computes a new sid based on the given
2954  * sid and the mls portion of mls_sid.
2955  */
2956 int security_sid_mls_copy(struct selinux_state *state,
2957                           u32 sid, u32 mls_sid, u32 *new_sid)
2958 {
2959         struct policydb *policydb = &state->ss->policydb;
2960         struct sidtab *sidtab = state->ss->sidtab;
2961         struct context *context1;
2962         struct context *context2;
2963         struct context newcon;
2964         char *s;
2965         u32 len;
2966         int rc;
2967
2968         rc = 0;
2969         if (!state->initialized || !policydb->mls_enabled) {
2970                 *new_sid = sid;
2971                 goto out;
2972         }
2973
2974         context_init(&newcon);
2975
2976         read_lock(&state->ss->policy_rwlock);
2977
2978         rc = -EINVAL;
2979         context1 = sidtab_search(sidtab, sid);
2980         if (!context1) {
2981                 pr_err("SELinux: %s:  unrecognized SID %d\n",
2982                         __func__, sid);
2983                 goto out_unlock;
2984         }
2985
2986         rc = -EINVAL;
2987         context2 = sidtab_search(sidtab, mls_sid);
2988         if (!context2) {
2989                 pr_err("SELinux: %s:  unrecognized SID %d\n",
2990                         __func__, mls_sid);
2991                 goto out_unlock;
2992         }
2993
2994         newcon.user = context1->user;
2995         newcon.role = context1->role;
2996         newcon.type = context1->type;
2997         rc = mls_context_cpy(&newcon, context2);
2998         if (rc)
2999                 goto out_unlock;
3000
3001         /* Check the validity of the new context. */
3002         if (!policydb_context_isvalid(policydb, &newcon)) {
3003                 rc = convert_context_handle_invalid_context(state, &newcon);
3004                 if (rc) {
3005                         if (!context_struct_to_string(policydb, &newcon, &s,
3006                                                       &len)) {
3007                                 struct audit_buffer *ab;
3008
3009                                 ab = audit_log_start(audit_context(),
3010                                                      GFP_ATOMIC,
3011                                                      AUDIT_SELINUX_ERR);
3012                                 audit_log_format(ab,
3013                                                  "op=security_sid_mls_copy invalid_context=");
3014                                 /* don't record NUL with untrusted strings */
3015                                 audit_log_n_untrustedstring(ab, s, len - 1);
3016                                 audit_log_end(ab);
3017                                 kfree(s);
3018                         }
3019                         goto out_unlock;
3020                 }
3021         }
3022
3023         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3024 out_unlock:
3025         read_unlock(&state->ss->policy_rwlock);
3026         context_destroy(&newcon);
3027 out:
3028         return rc;
3029 }
3030
3031 /**
3032  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3033  * @nlbl_sid: NetLabel SID
3034  * @nlbl_type: NetLabel labeling protocol type
3035  * @xfrm_sid: XFRM SID
3036  *
3037  * Description:
3038  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3039  * resolved into a single SID it is returned via @peer_sid and the function
3040  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3041  * returns a negative value.  A table summarizing the behavior is below:
3042  *
3043  *                                 | function return |      @sid
3044  *   ------------------------------+-----------------+-----------------
3045  *   no peer labels                |        0        |    SECSID_NULL
3046  *   single peer label             |        0        |    <peer_label>
3047  *   multiple, consistent labels   |        0        |    <peer_label>
3048  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3049  *
3050  */
3051 int security_net_peersid_resolve(struct selinux_state *state,
3052                                  u32 nlbl_sid, u32 nlbl_type,
3053                                  u32 xfrm_sid,
3054                                  u32 *peer_sid)
3055 {
3056         struct policydb *policydb = &state->ss->policydb;
3057         struct sidtab *sidtab = state->ss->sidtab;
3058         int rc;
3059         struct context *nlbl_ctx;
3060         struct context *xfrm_ctx;
3061
3062         *peer_sid = SECSID_NULL;
3063
3064         /* handle the common (which also happens to be the set of easy) cases
3065          * right away, these two if statements catch everything involving a
3066          * single or absent peer SID/label */
3067         if (xfrm_sid == SECSID_NULL) {
3068                 *peer_sid = nlbl_sid;
3069                 return 0;
3070         }
3071         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3072          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3073          * is present */
3074         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3075                 *peer_sid = xfrm_sid;
3076                 return 0;
3077         }
3078
3079         /*
3080          * We don't need to check initialized here since the only way both
3081          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3082          * security server was initialized and state->initialized was true.
3083          */
3084         if (!policydb->mls_enabled)
3085                 return 0;
3086
3087         read_lock(&state->ss->policy_rwlock);
3088
3089         rc = -EINVAL;
3090         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3091         if (!nlbl_ctx) {
3092                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3093                        __func__, nlbl_sid);
3094                 goto out;
3095         }
3096         rc = -EINVAL;
3097         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3098         if (!xfrm_ctx) {
3099                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3100                        __func__, xfrm_sid);
3101                 goto out;
3102         }
3103         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3104         if (rc)
3105                 goto out;
3106
3107         /* at present NetLabel SIDs/labels really only carry MLS
3108          * information so if the MLS portion of the NetLabel SID
3109          * matches the MLS portion of the labeled XFRM SID/label
3110          * then pass along the XFRM SID as it is the most
3111          * expressive */
3112         *peer_sid = xfrm_sid;
3113 out:
3114         read_unlock(&state->ss->policy_rwlock);
3115         return rc;
3116 }
3117
3118 static int get_classes_callback(void *k, void *d, void *args)
3119 {
3120         struct class_datum *datum = d;
3121         char *name = k, **classes = args;
3122         int value = datum->value - 1;
3123
3124         classes[value] = kstrdup(name, GFP_ATOMIC);
3125         if (!classes[value])
3126                 return -ENOMEM;
3127
3128         return 0;
3129 }
3130
3131 int security_get_classes(struct selinux_state *state,
3132                          char ***classes, int *nclasses)
3133 {
3134         struct policydb *policydb = &state->ss->policydb;
3135         int rc;
3136
3137         if (!state->initialized) {
3138                 *nclasses = 0;
3139                 *classes = NULL;
3140                 return 0;
3141         }
3142
3143         read_lock(&state->ss->policy_rwlock);
3144
3145         rc = -ENOMEM;
3146         *nclasses = policydb->p_classes.nprim;
3147         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3148         if (!*classes)
3149                 goto out;
3150
3151         rc = hashtab_map(policydb->p_classes.table, get_classes_callback,
3152                         *classes);
3153         if (rc) {
3154                 int i;
3155                 for (i = 0; i < *nclasses; i++)
3156                         kfree((*classes)[i]);
3157                 kfree(*classes);
3158         }
3159
3160 out:
3161         read_unlock(&state->ss->policy_rwlock);
3162         return rc;
3163 }
3164
3165 static int get_permissions_callback(void *k, void *d, void *args)
3166 {
3167         struct perm_datum *datum = d;
3168         char *name = k, **perms = args;
3169         int value = datum->value - 1;
3170
3171         perms[value] = kstrdup(name, GFP_ATOMIC);
3172         if (!perms[value])
3173                 return -ENOMEM;
3174
3175         return 0;
3176 }
3177
3178 int security_get_permissions(struct selinux_state *state,
3179                              char *class, char ***perms, int *nperms)
3180 {
3181         struct policydb *policydb = &state->ss->policydb;
3182         int rc, i;
3183         struct class_datum *match;
3184
3185         read_lock(&state->ss->policy_rwlock);
3186
3187         rc = -EINVAL;
3188         match = hashtab_search(policydb->p_classes.table, class);
3189         if (!match) {
3190                 pr_err("SELinux: %s:  unrecognized class %s\n",
3191                         __func__, class);
3192                 goto out;
3193         }
3194
3195         rc = -ENOMEM;
3196         *nperms = match->permissions.nprim;
3197         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3198         if (!*perms)
3199                 goto out;
3200
3201         if (match->comdatum) {
3202                 rc = hashtab_map(match->comdatum->permissions.table,
3203                                 get_permissions_callback, *perms);
3204                 if (rc)
3205                         goto err;
3206         }
3207
3208         rc = hashtab_map(match->permissions.table, get_permissions_callback,
3209                         *perms);
3210         if (rc)
3211                 goto err;
3212
3213 out:
3214         read_unlock(&state->ss->policy_rwlock);
3215         return rc;
3216
3217 err:
3218         read_unlock(&state->ss->policy_rwlock);
3219         for (i = 0; i < *nperms; i++)
3220                 kfree((*perms)[i]);
3221         kfree(*perms);
3222         return rc;
3223 }
3224
3225 int security_get_reject_unknown(struct selinux_state *state)
3226 {
3227         return state->ss->policydb.reject_unknown;
3228 }
3229
3230 int security_get_allow_unknown(struct selinux_state *state)
3231 {
3232         return state->ss->policydb.allow_unknown;
3233 }
3234
3235 /**
3236  * security_policycap_supported - Check for a specific policy capability
3237  * @req_cap: capability
3238  *
3239  * Description:
3240  * This function queries the currently loaded policy to see if it supports the
3241  * capability specified by @req_cap.  Returns true (1) if the capability is
3242  * supported, false (0) if it isn't supported.
3243  *
3244  */
3245 int security_policycap_supported(struct selinux_state *state,
3246                                  unsigned int req_cap)
3247 {
3248         struct policydb *policydb = &state->ss->policydb;
3249         int rc;
3250
3251         read_lock(&state->ss->policy_rwlock);
3252         rc = ebitmap_get_bit(&policydb->policycaps, req_cap);
3253         read_unlock(&state->ss->policy_rwlock);
3254
3255         return rc;
3256 }
3257
3258 struct selinux_audit_rule {
3259         u32 au_seqno;
3260         struct context au_ctxt;
3261 };
3262
3263 void selinux_audit_rule_free(void *vrule)
3264 {
3265         struct selinux_audit_rule *rule = vrule;
3266
3267         if (rule) {
3268                 context_destroy(&rule->au_ctxt);
3269                 kfree(rule);
3270         }
3271 }
3272
3273 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3274 {
3275         struct selinux_state *state = &selinux_state;
3276         struct policydb *policydb = &state->ss->policydb;
3277         struct selinux_audit_rule *tmprule;
3278         struct role_datum *roledatum;
3279         struct type_datum *typedatum;
3280         struct user_datum *userdatum;
3281         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3282         int rc = 0;
3283
3284         *rule = NULL;
3285
3286         if (!state->initialized)
3287                 return -EOPNOTSUPP;
3288
3289         switch (field) {
3290         case AUDIT_SUBJ_USER:
3291         case AUDIT_SUBJ_ROLE:
3292         case AUDIT_SUBJ_TYPE:
3293         case AUDIT_OBJ_USER:
3294         case AUDIT_OBJ_ROLE:
3295         case AUDIT_OBJ_TYPE:
3296                 /* only 'equals' and 'not equals' fit user, role, and type */
3297                 if (op != Audit_equal && op != Audit_not_equal)
3298                         return -EINVAL;
3299                 break;
3300         case AUDIT_SUBJ_SEN:
3301         case AUDIT_SUBJ_CLR:
3302         case AUDIT_OBJ_LEV_LOW:
3303         case AUDIT_OBJ_LEV_HIGH:
3304                 /* we do not allow a range, indicated by the presence of '-' */
3305                 if (strchr(rulestr, '-'))
3306                         return -EINVAL;
3307                 break;
3308         default:
3309                 /* only the above fields are valid */
3310                 return -EINVAL;
3311         }
3312
3313         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3314         if (!tmprule)
3315                 return -ENOMEM;
3316
3317         context_init(&tmprule->au_ctxt);
3318
3319         read_lock(&state->ss->policy_rwlock);
3320
3321         tmprule->au_seqno = state->ss->latest_granting;
3322
3323         switch (field) {
3324         case AUDIT_SUBJ_USER:
3325         case AUDIT_OBJ_USER:
3326                 rc = -EINVAL;
3327                 userdatum = hashtab_search(policydb->p_users.table, rulestr);
3328                 if (!userdatum)
3329                         goto out;
3330                 tmprule->au_ctxt.user = userdatum->value;
3331                 break;
3332         case AUDIT_SUBJ_ROLE:
3333         case AUDIT_OBJ_ROLE:
3334                 rc = -EINVAL;
3335                 roledatum = hashtab_search(policydb->p_roles.table, rulestr);
3336                 if (!roledatum)
3337                         goto out;
3338                 tmprule->au_ctxt.role = roledatum->value;
3339                 break;
3340         case AUDIT_SUBJ_TYPE:
3341         case AUDIT_OBJ_TYPE:
3342                 rc = -EINVAL;
3343                 typedatum = hashtab_search(policydb->p_types.table, rulestr);
3344                 if (!typedatum)
3345                         goto out;
3346                 tmprule->au_ctxt.type = typedatum->value;
3347                 break;
3348         case AUDIT_SUBJ_SEN:
3349         case AUDIT_SUBJ_CLR:
3350         case AUDIT_OBJ_LEV_LOW:
3351         case AUDIT_OBJ_LEV_HIGH:
3352                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3353                                      GFP_ATOMIC);
3354                 if (rc)
3355                         goto out;
3356                 break;
3357         }
3358         rc = 0;
3359 out:
3360         read_unlock(&state->ss->policy_rwlock);
3361
3362         if (rc) {
3363                 selinux_audit_rule_free(tmprule);
3364                 tmprule = NULL;
3365         }
3366
3367         *rule = tmprule;
3368
3369         return rc;
3370 }
3371
3372 /* Check to see if the rule contains any selinux fields */
3373 int selinux_audit_rule_known(struct audit_krule *rule)
3374 {
3375         int i;
3376
3377         for (i = 0; i < rule->field_count; i++) {
3378                 struct audit_field *f = &rule->fields[i];
3379                 switch (f->type) {
3380                 case AUDIT_SUBJ_USER:
3381                 case AUDIT_SUBJ_ROLE:
3382                 case AUDIT_SUBJ_TYPE:
3383                 case AUDIT_SUBJ_SEN:
3384                 case AUDIT_SUBJ_CLR:
3385                 case AUDIT_OBJ_USER:
3386                 case AUDIT_OBJ_ROLE:
3387                 case AUDIT_OBJ_TYPE:
3388                 case AUDIT_OBJ_LEV_LOW:
3389                 case AUDIT_OBJ_LEV_HIGH:
3390                         return 1;
3391                 }
3392         }
3393
3394         return 0;
3395 }
3396
3397 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3398 {
3399         struct selinux_state *state = &selinux_state;
3400         struct context *ctxt;
3401         struct mls_level *level;
3402         struct selinux_audit_rule *rule = vrule;
3403         int match = 0;
3404
3405         if (unlikely(!rule)) {
3406                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3407                 return -ENOENT;
3408         }
3409
3410         read_lock(&state->ss->policy_rwlock);
3411
3412         if (rule->au_seqno < state->ss->latest_granting) {
3413                 match = -ESTALE;
3414                 goto out;
3415         }
3416
3417         ctxt = sidtab_search(state->ss->sidtab, sid);
3418         if (unlikely(!ctxt)) {
3419                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3420                           sid);
3421                 match = -ENOENT;
3422                 goto out;
3423         }
3424
3425         /* a field/op pair that is not caught here will simply fall through
3426            without a match */
3427         switch (field) {
3428         case AUDIT_SUBJ_USER:
3429         case AUDIT_OBJ_USER:
3430                 switch (op) {
3431                 case Audit_equal:
3432                         match = (ctxt->user == rule->au_ctxt.user);
3433                         break;
3434                 case Audit_not_equal:
3435                         match = (ctxt->user != rule->au_ctxt.user);
3436                         break;
3437                 }
3438                 break;
3439         case AUDIT_SUBJ_ROLE:
3440         case AUDIT_OBJ_ROLE:
3441                 switch (op) {
3442                 case Audit_equal:
3443                         match = (ctxt->role == rule->au_ctxt.role);
3444                         break;
3445                 case Audit_not_equal:
3446                         match = (ctxt->role != rule->au_ctxt.role);
3447                         break;
3448                 }
3449                 break;
3450         case AUDIT_SUBJ_TYPE:
3451         case AUDIT_OBJ_TYPE:
3452                 switch (op) {
3453                 case Audit_equal:
3454                         match = (ctxt->type == rule->au_ctxt.type);
3455                         break;
3456                 case Audit_not_equal:
3457                         match = (ctxt->type != rule->au_ctxt.type);
3458                         break;
3459                 }
3460                 break;
3461         case AUDIT_SUBJ_SEN:
3462         case AUDIT_SUBJ_CLR:
3463         case AUDIT_OBJ_LEV_LOW:
3464         case AUDIT_OBJ_LEV_HIGH:
3465                 level = ((field == AUDIT_SUBJ_SEN ||
3466                           field == AUDIT_OBJ_LEV_LOW) ?
3467                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3468                 switch (op) {
3469                 case Audit_equal:
3470                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3471                                              level);
3472                         break;
3473                 case Audit_not_equal:
3474                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3475                                               level);
3476                         break;
3477                 case Audit_lt:
3478                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3479                                                level) &&
3480                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3481                                                level));
3482                         break;
3483                 case Audit_le:
3484                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3485                                               level);
3486                         break;
3487                 case Audit_gt:
3488                         match = (mls_level_dom(level,
3489                                               &rule->au_ctxt.range.level[0]) &&
3490                                  !mls_level_eq(level,
3491                                                &rule->au_ctxt.range.level[0]));
3492                         break;
3493                 case Audit_ge:
3494                         match = mls_level_dom(level,
3495                                               &rule->au_ctxt.range.level[0]);
3496                         break;
3497                 }
3498         }
3499
3500 out:
3501         read_unlock(&state->ss->policy_rwlock);
3502         return match;
3503 }
3504
3505 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3506
3507 static int aurule_avc_callback(u32 event)
3508 {
3509         int err = 0;
3510
3511         if (event == AVC_CALLBACK_RESET && aurule_callback)
3512                 err = aurule_callback();
3513         return err;
3514 }
3515
3516 static int __init aurule_init(void)
3517 {
3518         int err;
3519
3520         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3521         if (err)
3522                 panic("avc_add_callback() failed, error %d\n", err);
3523
3524         return err;
3525 }
3526 __initcall(aurule_init);
3527
3528 #ifdef CONFIG_NETLABEL
3529 /**
3530  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3531  * @secattr: the NetLabel packet security attributes
3532  * @sid: the SELinux SID
3533  *
3534  * Description:
3535  * Attempt to cache the context in @ctx, which was derived from the packet in
3536  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3537  * already been initialized.
3538  *
3539  */
3540 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3541                                       u32 sid)
3542 {
3543         u32 *sid_cache;
3544
3545         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3546         if (sid_cache == NULL)
3547                 return;
3548         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3549         if (secattr->cache == NULL) {
3550                 kfree(sid_cache);
3551                 return;
3552         }
3553
3554         *sid_cache = sid;
3555         secattr->cache->free = kfree;
3556         secattr->cache->data = sid_cache;
3557         secattr->flags |= NETLBL_SECATTR_CACHE;
3558 }
3559
3560 /**
3561  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3562  * @secattr: the NetLabel packet security attributes
3563  * @sid: the SELinux SID
3564  *
3565  * Description:
3566  * Convert the given NetLabel security attributes in @secattr into a
3567  * SELinux SID.  If the @secattr field does not contain a full SELinux
3568  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3569  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3570  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3571  * conversion for future lookups.  Returns zero on success, negative values on
3572  * failure.
3573  *
3574  */
3575 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3576                                    struct netlbl_lsm_secattr *secattr,
3577                                    u32 *sid)
3578 {
3579         struct policydb *policydb = &state->ss->policydb;
3580         struct sidtab *sidtab = state->ss->sidtab;
3581         int rc;
3582         struct context *ctx;
3583         struct context ctx_new;
3584
3585         if (!state->initialized) {
3586                 *sid = SECSID_NULL;
3587                 return 0;
3588         }
3589
3590         read_lock(&state->ss->policy_rwlock);
3591
3592         if (secattr->flags & NETLBL_SECATTR_CACHE)
3593                 *sid = *(u32 *)secattr->cache->data;
3594         else if (secattr->flags & NETLBL_SECATTR_SECID)
3595                 *sid = secattr->attr.secid;
3596         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3597                 rc = -EIDRM;
3598                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3599                 if (ctx == NULL)
3600                         goto out;
3601
3602                 context_init(&ctx_new);
3603                 ctx_new.user = ctx->user;
3604                 ctx_new.role = ctx->role;
3605                 ctx_new.type = ctx->type;
3606                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3607                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3608                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3609                         if (rc)
3610                                 goto out;
3611                 }
3612                 rc = -EIDRM;
3613                 if (!mls_context_isvalid(policydb, &ctx_new))
3614                         goto out_free;
3615
3616                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3617                 if (rc)
3618                         goto out_free;
3619
3620                 security_netlbl_cache_add(secattr, *sid);
3621
3622                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3623         } else
3624                 *sid = SECSID_NULL;
3625
3626         read_unlock(&state->ss->policy_rwlock);
3627         return 0;
3628 out_free:
3629         ebitmap_destroy(&ctx_new.range.level[0].cat);
3630 out:
3631         read_unlock(&state->ss->policy_rwlock);
3632         return rc;
3633 }
3634
3635 /**
3636  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3637  * @sid: the SELinux SID
3638  * @secattr: the NetLabel packet security attributes
3639  *
3640  * Description:
3641  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3642  * Returns zero on success, negative values on failure.
3643  *
3644  */
3645 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3646                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3647 {
3648         struct policydb *policydb = &state->ss->policydb;
3649         int rc;
3650         struct context *ctx;
3651
3652         if (!state->initialized)
3653                 return 0;
3654
3655         read_lock(&state->ss->policy_rwlock);
3656
3657         rc = -ENOENT;
3658         ctx = sidtab_search(state->ss->sidtab, sid);
3659         if (ctx == NULL)
3660                 goto out;
3661
3662         rc = -ENOMEM;
3663         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3664                                   GFP_ATOMIC);
3665         if (secattr->domain == NULL)
3666                 goto out;
3667
3668         secattr->attr.secid = sid;
3669         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3670         mls_export_netlbl_lvl(policydb, ctx, secattr);
3671         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3672 out:
3673         read_unlock(&state->ss->policy_rwlock);
3674         return rc;
3675 }
3676 #endif /* CONFIG_NETLABEL */
3677
3678 /**
3679  * security_read_policy - read the policy.
3680  * @data: binary policy data
3681  * @len: length of data in bytes
3682  *
3683  */
3684 int security_read_policy(struct selinux_state *state,
3685                          void **data, size_t *len)
3686 {
3687         struct policydb *policydb = &state->ss->policydb;
3688         int rc;
3689         struct policy_file fp;
3690
3691         if (!state->initialized)
3692                 return -EINVAL;
3693
3694         *len = security_policydb_len(state);
3695
3696         *data = vmalloc_user(*len);
3697         if (!*data)
3698                 return -ENOMEM;
3699
3700         fp.data = *data;
3701         fp.len = *len;
3702
3703         read_lock(&state->ss->policy_rwlock);
3704         rc = policydb_write(policydb, &fp);
3705         read_unlock(&state->ss->policy_rwlock);
3706
3707         if (rc)
3708                 return rc;
3709
3710         *len = (unsigned long)fp.data - (unsigned long)*data;
3711         return 0;
3712
3713 }