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/vmalloc.h>
  50 #include <net/netlabel.h>
  51
  52 #include "flask.h"
  53 #include "avc.h"
  54 #include "avc_ss.h"
  55 #include "security.h"
  56 #include "context.h"
  57 #include "policydb.h"
  58 #include "sidtab.h"
  59 #include "services.h"
  60 #include "conditional.h"
  61 #include "mls.h"
  62 #include "objsec.h"
  63 #include "netlabel.h"
  64 #include "xfrm.h"
  65 #include "ebitmap.h"
  66 #include "audit.h"
  67
  68 /* Policy capability names */
  69 const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
  70         "network_peer_controls",
  71         "open_perms",
  72         "extended_socket_class",
  73         "always_check_network",
  74         "cgroup_seclabel",
  75         "nnp_nosuid_transition",
  76         "genfs_seclabel_symlinks"
  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         *ss = &selinux_ss;
  85 }
  86
  87 /* Forward declaration. */
  88 static int context_struct_to_string(struct policydb *policydb,
  89                                     struct context *context,
  90                                     char **scontext,
  91                                     u32 *scontext_len);
  92
  93 static int sidtab_entry_to_string(struct policydb *policydb,
  94                                   struct sidtab *sidtab,
  95                                   struct sidtab_entry *entry,
  96                                   char **scontext,
  97                                   u32 *scontext_len);
  98
  99 static void context_struct_compute_av(struct policydb *policydb,
 100                                       struct context *scontext,
 101                                       struct context *tcontext,
 102                                       u16 tclass,
 103                                       struct av_decision *avd,
 104                                       struct extended_perms *xperms);
 105
 106 static int selinux_set_mapping(struct policydb *pol,
 107                                struct security_class_mapping *map,
 108                                struct selinux_map *out_map)
 109 {
 110         u16 i, j;
 111         unsigned k;
 112         bool print_unknown_handle = false;
 113
 114         /* Find number of classes in the input mapping */
 115         if (!map)
 116                 return -EINVAL;
 117         i = 0;
 118         while (map[i].name)
 119                 i++;
 120
 121         /* Allocate space for the class records, plus one for class zero */
 122         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 123         if (!out_map->mapping)
 124                 return -ENOMEM;
 125
 126         /* Store the raw class and permission values */
 127         j = 0;
 128         while (map[j].name) {
 129                 struct security_class_mapping *p_in = map + (j++);
 130                 struct selinux_mapping *p_out = out_map->mapping + j;
 131
 132                 /* An empty class string skips ahead */
 133                 if (!strcmp(p_in->name, "")) {
 134                         p_out->num_perms = 0;
 135                         continue;
 136                 }
 137
 138                 p_out->value = string_to_security_class(pol, p_in->name);
 139                 if (!p_out->value) {
 140                         pr_info("SELinux:  Class %s not defined in policy.\n",
 141                                p_in->name);
 142                         if (pol->reject_unknown)
 143                                 goto err;
 144                         p_out->num_perms = 0;
 145                         print_unknown_handle = true;
 146                         continue;
 147                 }
 148
 149                 k = 0;
 150                 while (p_in->perms[k]) {
 151                         /* An empty permission string skips ahead */
 152                         if (!*p_in->perms[k]) {
 153                                 k++;
 154                                 continue;
 155                         }
 156                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 157                                                             p_in->perms[k]);
 158                         if (!p_out->perms[k]) {
 159                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 160                                        p_in->perms[k], p_in->name);
 161                                 if (pol->reject_unknown)
 162                                         goto err;
 163                                 print_unknown_handle = true;
 164                         }
 165
 166                         k++;
 167                 }
 168                 p_out->num_perms = k;
 169         }
 170
 171         if (print_unknown_handle)
 172                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 173                        pol->allow_unknown ? "allowed" : "denied");
 174
 175         out_map->size = i;
 176         return 0;
 177 err:
 178         kfree(out_map->mapping);
 179         out_map->mapping = NULL;
 180         return -EINVAL;
 181 }
 182
 183 /*
 184  * Get real, policy values from mapped values
 185  */
 186
 187 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 188 {
 189         if (tclass < map->size)
 190                 return map->mapping[tclass].value;
 191
 192         return tclass;
 193 }
 194
 195 /*
 196  * Get kernel value for class from its policy value
 197  */
 198 static u16 map_class(struct selinux_map *map, u16 pol_value)
 199 {
 200         u16 i;
 201
 202         for (i = 1; i < map->size; i++) {
 203                 if (map->mapping[i].value == pol_value)
 204                         return i;
 205         }
 206
 207         return SECCLASS_NULL;
 208 }
 209
 210 static void map_decision(struct selinux_map *map,
 211                          u16 tclass, struct av_decision *avd,
 212                          int allow_unknown)
 213 {
 214         if (tclass < map->size) {
 215                 struct selinux_mapping *mapping = &map->mapping[tclass];
 216                 unsigned int i, n = mapping->num_perms;
 217                 u32 result;
 218
 219                 for (i = 0, result = 0; i < n; i++) {
 220                         if (avd->allowed & mapping->perms[i])
 221                                 result |= 1<<i;
 222                         if (allow_unknown && !mapping->perms[i])
 223                                 result |= 1<<i;
 224                 }
 225                 avd->allowed = result;
 226
 227                 for (i = 0, result = 0; i < n; i++)
 228                         if (avd->auditallow & mapping->perms[i])
 229                                 result |= 1<<i;
 230                 avd->auditallow = result;
 231
 232                 for (i = 0, result = 0; i < n; i++) {
 233                         if (avd->auditdeny & mapping->perms[i])
 234                                 result |= 1<<i;
 235                         if (!allow_unknown && !mapping->perms[i])
 236                                 result |= 1<<i;
 237                 }
 238                 /*
 239                  * In case the kernel has a bug and requests a permission
 240                  * between num_perms and the maximum permission number, we
 241                  * should audit that denial
 242                  */
 243                 for (; i < (sizeof(u32)*8); i++)
 244                         result |= 1<<i;
 245                 avd->auditdeny = result;
 246         }
 247 }
 248
 249 int security_mls_enabled(struct selinux_state *state)
 250 {
 251         struct policydb *p = &state->ss->policydb;
 252
 253         return p->mls_enabled;
 254 }
 255
 256 /*
 257  * Return the boolean value of a constraint expression
 258  * when it is applied to the specified source and target
 259  * security contexts.
 260  *
 261  * xcontext is a special beast...  It is used by the validatetrans rules
 262  * only.  For these rules, scontext is the context before the transition,
 263  * tcontext is the context after the transition, and xcontext is the context
 264  * of the process performing the transition.  All other callers of
 265  * constraint_expr_eval should pass in NULL for xcontext.
 266  */
 267 static int constraint_expr_eval(struct policydb *policydb,
 268                                 struct context *scontext,
 269                                 struct context *tcontext,
 270                                 struct context *xcontext,
 271                                 struct constraint_expr *cexpr)
 272 {
 273         u32 val1, val2;
 274         struct context *c;
 275         struct role_datum *r1, *r2;
 276         struct mls_level *l1, *l2;
 277         struct constraint_expr *e;
 278         int s[CEXPR_MAXDEPTH];
 279         int sp = -1;
 280
 281         for (e = cexpr; e; e = e->next) {
 282                 switch (e->expr_type) {
 283                 case CEXPR_NOT:
 284                         BUG_ON(sp < 0);
 285                         s[sp] = !s[sp];
 286                         break;
 287                 case CEXPR_AND:
 288                         BUG_ON(sp < 1);
 289                         sp--;
 290                         s[sp] &= s[sp + 1];
 291                         break;
 292                 case CEXPR_OR:
 293                         BUG_ON(sp < 1);
 294                         sp--;
 295                         s[sp] |= s[sp + 1];
 296                         break;
 297                 case CEXPR_ATTR:
 298                         if (sp == (CEXPR_MAXDEPTH - 1))
 299                                 return 0;
 300                         switch (e->attr) {
 301                         case CEXPR_USER:
 302                                 val1 = scontext->user;
 303                                 val2 = tcontext->user;
 304                                 break;
 305                         case CEXPR_TYPE:
 306                                 val1 = scontext->type;
 307                                 val2 = tcontext->type;
 308                                 break;
 309                         case CEXPR_ROLE:
 310                                 val1 = scontext->role;
 311                                 val2 = tcontext->role;
 312                                 r1 = policydb->role_val_to_struct[val1 - 1];
 313                                 r2 = policydb->role_val_to_struct[val2 - 1];
 314                                 switch (e->op) {
 315                                 case CEXPR_DOM:
 316                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 317                                                                   val2 - 1);
 318                                         continue;
 319                                 case CEXPR_DOMBY:
 320                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 321                                                                   val1 - 1);
 322                                         continue;
 323                                 case CEXPR_INCOMP:
 324                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 325                                                                     val2 - 1) &&
 326                                                    !ebitmap_get_bit(&r2->dominates,
 327                                                                     val1 - 1));
 328                                         continue;
 329                                 default:
 330                                         break;
 331                                 }
 332                                 break;
 333                         case CEXPR_L1L2:
 334                                 l1 = &(scontext->range.level[0]);
 335                                 l2 = &(tcontext->range.level[0]);
 336                                 goto mls_ops;
 337                         case CEXPR_L1H2:
 338                                 l1 = &(scontext->range.level[0]);
 339                                 l2 = &(tcontext->range.level[1]);
 340                                 goto mls_ops;
 341                         case CEXPR_H1L2:
 342                                 l1 = &(scontext->range.level[1]);
 343                                 l2 = &(tcontext->range.level[0]);
 344                                 goto mls_ops;
 345                         case CEXPR_H1H2:
 346                                 l1 = &(scontext->range.level[1]);
 347                                 l2 = &(tcontext->range.level[1]);
 348                                 goto mls_ops;
 349                         case CEXPR_L1H1:
 350                                 l1 = &(scontext->range.level[0]);
 351                                 l2 = &(scontext->range.level[1]);
 352                                 goto mls_ops;
 353                         case CEXPR_L2H2:
 354                                 l1 = &(tcontext->range.level[0]);
 355                                 l2 = &(tcontext->range.level[1]);
 356                                 goto mls_ops;
 357 mls_ops:
 358                         switch (e->op) {
 359                         case CEXPR_EQ:
 360                                 s[++sp] = mls_level_eq(l1, l2);
 361                                 continue;
 362                         case CEXPR_NEQ:
 363                                 s[++sp] = !mls_level_eq(l1, l2);
 364                                 continue;
 365                         case CEXPR_DOM:
 366                                 s[++sp] = mls_level_dom(l1, l2);
 367                                 continue;
 368                         case CEXPR_DOMBY:
 369                                 s[++sp] = mls_level_dom(l2, l1);
 370                                 continue;
 371                         case CEXPR_INCOMP:
 372                                 s[++sp] = mls_level_incomp(l2, l1);
 373                                 continue;
 374                         default:
 375                                 BUG();
 376                                 return 0;
 377                         }
 378                         break;
 379                         default:
 380                                 BUG();
 381                                 return 0;
 382                         }
 383
 384                         switch (e->op) {
 385                         case CEXPR_EQ:
 386                                 s[++sp] = (val1 == val2);
 387                                 break;
 388                         case CEXPR_NEQ:
 389                                 s[++sp] = (val1 != val2);
 390                                 break;
 391                         default:
 392                                 BUG();
 393                                 return 0;
 394                         }
 395                         break;
 396                 case CEXPR_NAMES:
 397                         if (sp == (CEXPR_MAXDEPTH-1))
 398                                 return 0;
 399                         c = scontext;
 400                         if (e->attr & CEXPR_TARGET)
 401                                 c = tcontext;
 402                         else if (e->attr & CEXPR_XTARGET) {
 403                                 c = xcontext;
 404                                 if (!c) {
 405                                         BUG();
 406                                         return 0;
 407                                 }
 408                         }
 409                         if (e->attr & CEXPR_USER)
 410                                 val1 = c->user;
 411                         else if (e->attr & CEXPR_ROLE)
 412                                 val1 = c->role;
 413                         else if (e->attr & CEXPR_TYPE)
 414                                 val1 = c->type;
 415                         else {
 416                                 BUG();
 417                                 return 0;
 418                         }
 419
 420                         switch (e->op) {
 421                         case CEXPR_EQ:
 422                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 423                                 break;
 424                         case CEXPR_NEQ:
 425                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         default:
 428                                 BUG();
 429                                 return 0;
 430                         }
 431                         break;
 432                 default:
 433                         BUG();
 434                         return 0;
 435                 }
 436         }
 437
 438         BUG_ON(sp != 0);
 439         return s[0];
 440 }
 441
 442 /*
 443  * security_dump_masked_av - dumps masked permissions during
 444  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 445  */
 446 static int dump_masked_av_helper(void *k, void *d, void *args)
 447 {
 448         struct perm_datum *pdatum = d;
 449         char **permission_names = args;
 450
 451         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 452
 453         permission_names[pdatum->value - 1] = (char *)k;
 454
 455         return 0;
 456 }
 457
 458 static void security_dump_masked_av(struct policydb *policydb,
 459                                     struct context *scontext,
 460                                     struct context *tcontext,
 461                                     u16 tclass,
 462                                     u32 permissions,
 463                                     const char *reason)
 464 {
 465         struct common_datum *common_dat;
 466         struct class_datum *tclass_dat;
 467         struct audit_buffer *ab;
 468         char *tclass_name;
 469         char *scontext_name = NULL;
 470         char *tcontext_name = NULL;
 471         char *permission_names[32];
 472         int index;
 473         u32 length;
 474         bool need_comma = false;
 475
 476         if (!permissions)
 477                 return;
 478
 479         tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
 480         tclass_dat = policydb->class_val_to_struct[tclass - 1];
 481         common_dat = tclass_dat->comdatum;
 482
 483         /* init permission_names */
 484         if (common_dat &&
 485             hashtab_map(common_dat->permissions.table,
 486                         dump_masked_av_helper, permission_names) < 0)
 487                 goto out;
 488
 489         if (hashtab_map(tclass_dat->permissions.table,
 490                         dump_masked_av_helper, permission_names) < 0)
 491                 goto out;
 492
 493         /* get scontext/tcontext in text form */
 494         if (context_struct_to_string(policydb, scontext,
 495                                      &scontext_name, &length) < 0)
 496                 goto out;
 497
 498         if (context_struct_to_string(policydb, tcontext,
 499                                      &tcontext_name, &length) < 0)
 500                 goto out;
 501
 502         /* audit a message */
 503         ab = audit_log_start(audit_context(),
 504                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 505         if (!ab)
 506                 goto out;
 507
 508         audit_log_format(ab, "op=security_compute_av reason=%s "
 509                          "scontext=%s tcontext=%s tclass=%s perms=",
 510                          reason, scontext_name, tcontext_name, tclass_name);
 511
 512         for (index = 0; index < 32; index++) {
 513                 u32 mask = (1 << index);
 514
 515                 if ((mask & permissions) == 0)
 516                         continue;
 517
 518                 audit_log_format(ab, "%s%s",
 519                                  need_comma ? "," : "",
 520                                  permission_names[index]
 521                                  ? permission_names[index] : "????");
 522                 need_comma = true;
 523         }
 524         audit_log_end(ab);
 525 out:
 526         /* release scontext/tcontext */
 527         kfree(tcontext_name);
 528         kfree(scontext_name);
 529
 530         return;
 531 }
 532
 533 /*
 534  * security_boundary_permission - drops violated permissions
 535  * on boundary constraint.
 536  */
 537 static void type_attribute_bounds_av(struct policydb *policydb,
 538                                      struct context *scontext,
 539                                      struct context *tcontext,
 540                                      u16 tclass,
 541                                      struct av_decision *avd)
 542 {
 543         struct context lo_scontext;
 544         struct context lo_tcontext, *tcontextp = tcontext;
 545         struct av_decision lo_avd;
 546         struct type_datum *source;
 547         struct type_datum *target;
 548         u32 masked = 0;
 549
 550         source = policydb->type_val_to_struct[scontext->type - 1];
 551         BUG_ON(!source);
 552
 553         if (!source->bounds)
 554                 return;
 555
 556         target = policydb->type_val_to_struct[tcontext->type - 1];
 557         BUG_ON(!target);
 558
 559         memset(&lo_avd, 0, sizeof(lo_avd));
 560
 561         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 562         lo_scontext.type = source->bounds;
 563
 564         if (target->bounds) {
 565                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 566                 lo_tcontext.type = target->bounds;
 567                 tcontextp = &lo_tcontext;
 568         }
 569
 570         context_struct_compute_av(policydb, &lo_scontext,
 571                                   tcontextp,
 572                                   tclass,
 573                                   &lo_avd,
 574                                   NULL);
 575
 576         masked = ~lo_avd.allowed & avd->allowed;
 577
 578         if (likely(!masked))
 579                 return;         /* no masked permission */
 580
 581         /* mask violated permissions */
 582         avd->allowed &= ~masked;
 583
 584         /* audit masked permissions */
 585         security_dump_masked_av(policydb, scontext, tcontext,
 586                                 tclass, masked, "bounds");
 587 }
 588
 589 /*
 590  * flag which drivers have permissions
 591  * only looking for ioctl based extended permssions
 592  */
 593 void services_compute_xperms_drivers(
 594                 struct extended_perms *xperms,
 595                 struct avtab_node *node)
 596 {
 597         unsigned int i;
 598
 599         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 600                 /* if one or more driver has all permissions allowed */
 601                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 602                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 603         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 604                 /* if allowing permissions within a driver */
 605                 security_xperm_set(xperms->drivers.p,
 606                                         node->datum.u.xperms->driver);
 607         }
 608
 609         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 610         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 611                 xperms->len = 1;
 612 }
 613
 614 /*
 615  * Compute access vectors and extended permissions based on a context
 616  * structure pair for the permissions in a particular class.
 617  */
 618 static void context_struct_compute_av(struct policydb *policydb,
 619                                       struct context *scontext,
 620                                       struct context *tcontext,
 621                                       u16 tclass,
 622                                       struct av_decision *avd,
 623                                       struct extended_perms *xperms)
 624 {
 625         struct constraint_node *constraint;
 626         struct role_allow *ra;
 627         struct avtab_key avkey;
 628         struct avtab_node *node;
 629         struct class_datum *tclass_datum;
 630         struct ebitmap *sattr, *tattr;
 631         struct ebitmap_node *snode, *tnode;
 632         unsigned int i, j;
 633
 634         avd->allowed = 0;
 635         avd->auditallow = 0;
 636         avd->auditdeny = 0xffffffff;
 637         if (xperms) {
 638                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 639                 xperms->len = 0;
 640         }
 641
 642         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 643                 if (printk_ratelimit())
 644                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 645                 return;
 646         }
 647
 648         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 649
 650         /*
 651          * If a specific type enforcement rule was defined for
 652          * this permission check, then use it.
 653          */
 654         avkey.target_class = tclass;
 655         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 656         sattr = &policydb->type_attr_map_array[scontext->type - 1];
 657         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 658         ebitmap_for_each_positive_bit(sattr, snode, i) {
 659                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 660                         avkey.source_type = i + 1;
 661                         avkey.target_type = j + 1;
 662                         for (node = avtab_search_node(&policydb->te_avtab,
 663                                                       &avkey);
 664                              node;
 665                              node = avtab_search_node_next(node, avkey.specified)) {
 666                                 if (node->key.specified == AVTAB_ALLOWED)
 667                                         avd->allowed |= node->datum.u.data;
 668                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 669                                         avd->auditallow |= node->datum.u.data;
 670                                 else if (node->key.specified == AVTAB_AUDITDENY)
 671                                         avd->auditdeny &= node->datum.u.data;
 672                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 673                                         services_compute_xperms_drivers(xperms, node);
 674                         }
 675
 676                         /* Check conditional av table for additional permissions */
 677                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 678                                         avd, xperms);
 679
 680                 }
 681         }
 682
 683         /*
 684          * Remove any permissions prohibited by a constraint (this includes
 685          * the MLS policy).
 686          */
 687         constraint = tclass_datum->constraints;
 688         while (constraint) {
 689                 if ((constraint->permissions & (avd->allowed)) &&
 690                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 691                                           constraint->expr)) {
 692                         avd->allowed &= ~(constraint->permissions);
 693                 }
 694                 constraint = constraint->next;
 695         }
 696
 697         /*
 698          * If checking process transition permission and the
 699          * role is changing, then check the (current_role, new_role)
 700          * pair.
 701          */
 702         if (tclass == policydb->process_class &&
 703             (avd->allowed & policydb->process_trans_perms) &&
 704             scontext->role != tcontext->role) {
 705                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 706                         if (scontext->role == ra->role &&
 707                             tcontext->role == ra->new_role)
 708                                 break;
 709                 }
 710                 if (!ra)
 711                         avd->allowed &= ~policydb->process_trans_perms;
 712         }
 713
 714         /*
 715          * If the given source and target types have boundary
 716          * constraint, lazy checks have to mask any violated
 717          * permission and notice it to userspace via audit.
 718          */
 719         type_attribute_bounds_av(policydb, scontext, tcontext,
 720                                  tclass, avd);
 721 }
 722
 723 static int security_validtrans_handle_fail(struct selinux_state *state,
 724                                            struct sidtab_entry *oentry,
 725                                            struct sidtab_entry *nentry,
 726                                            struct sidtab_entry *tentry,
 727                                            u16 tclass)
 728 {
 729         struct policydb *p = &state->ss->policydb;
 730         struct sidtab *sidtab = state->ss->sidtab;
 731         char *o = NULL, *n = NULL, *t = NULL;
 732         u32 olen, nlen, tlen;
 733
 734         if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
 735                 goto out;
 736         if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
 737                 goto out;
 738         if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
 739                 goto out;
 740         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 741                   "op=security_validate_transition seresult=denied"
 742                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 743                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 744 out:
 745         kfree(o);
 746         kfree(n);
 747         kfree(t);
 748
 749         if (!enforcing_enabled(state))
 750                 return 0;
 751         return -EPERM;
 752 }
 753
 754 static int security_compute_validatetrans(struct selinux_state *state,
 755                                           u32 oldsid, u32 newsid, u32 tasksid,
 756                                           u16 orig_tclass, bool user)
 757 {
 758         struct policydb *policydb;
 759         struct sidtab *sidtab;
 760         struct sidtab_entry *oentry;
 761         struct sidtab_entry *nentry;
 762         struct sidtab_entry *tentry;
 763         struct class_datum *tclass_datum;
 764         struct constraint_node *constraint;
 765         u16 tclass;
 766         int rc = 0;
 767
 768
 769         if (!selinux_initialized(state))
 770                 return 0;
 771
 772         read_lock(&state->ss->policy_rwlock);
 773
 774         policydb = &state->ss->policydb;
 775         sidtab = state->ss->sidtab;
 776
 777         if (!user)
 778                 tclass = unmap_class(&state->ss->map, orig_tclass);
 779         else
 780                 tclass = orig_tclass;
 781
 782         if (!tclass || tclass > policydb->p_classes.nprim) {
 783                 rc = -EINVAL;
 784                 goto out;
 785         }
 786         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 787
 788         oentry = sidtab_search_entry(sidtab, oldsid);
 789         if (!oentry) {
 790                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 791                         __func__, oldsid);
 792                 rc = -EINVAL;
 793                 goto out;
 794         }
 795
 796         nentry = sidtab_search_entry(sidtab, newsid);
 797         if (!nentry) {
 798                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 799                         __func__, newsid);
 800                 rc = -EINVAL;
 801                 goto out;
 802         }
 803
 804         tentry = sidtab_search_entry(sidtab, tasksid);
 805         if (!tentry) {
 806                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 807                         __func__, tasksid);
 808                 rc = -EINVAL;
 809                 goto out;
 810         }
 811
 812         constraint = tclass_datum->validatetrans;
 813         while (constraint) {
 814                 if (!constraint_expr_eval(policydb, &oentry->context,
 815                                           &nentry->context, &tentry->context,
 816                                           constraint->expr)) {
 817                         if (user)
 818                                 rc = -EPERM;
 819                         else
 820                                 rc = security_validtrans_handle_fail(state,
 821                                                                      oentry,
 822                                                                      nentry,
 823                                                                      tentry,
 824                                                                      tclass);
 825                         goto out;
 826                 }
 827                 constraint = constraint->next;
 828         }
 829
 830 out:
 831         read_unlock(&state->ss->policy_rwlock);
 832         return rc;
 833 }
 834
 835 int security_validate_transition_user(struct selinux_state *state,
 836                                       u32 oldsid, u32 newsid, u32 tasksid,
 837                                       u16 tclass)
 838 {
 839         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 840                                               tclass, true);
 841 }
 842
 843 int security_validate_transition(struct selinux_state *state,
 844                                  u32 oldsid, u32 newsid, u32 tasksid,
 845                                  u16 orig_tclass)
 846 {
 847         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 848                                               orig_tclass, false);
 849 }
 850
 851 /*
 852  * security_bounded_transition - check whether the given
 853  * transition is directed to bounded, or not.
 854  * It returns 0, if @newsid is bounded by @oldsid.
 855  * Otherwise, it returns error code.
 856  *
 857  * @oldsid : current security identifier
 858  * @newsid : destinated security identifier
 859  */
 860 int security_bounded_transition(struct selinux_state *state,
 861                                 u32 old_sid, u32 new_sid)
 862 {
 863         struct policydb *policydb;
 864         struct sidtab *sidtab;
 865         struct sidtab_entry *old_entry, *new_entry;
 866         struct type_datum *type;
 867         int index;
 868         int rc;
 869
 870         if (!selinux_initialized(state))
 871                 return 0;
 872
 873         read_lock(&state->ss->policy_rwlock);
 874
 875         policydb = &state->ss->policydb;
 876         sidtab = state->ss->sidtab;
 877
 878         rc = -EINVAL;
 879         old_entry = sidtab_search_entry(sidtab, old_sid);
 880         if (!old_entry) {
 881                 pr_err("SELinux: %s: unrecognized SID %u\n",
 882                        __func__, old_sid);
 883                 goto out;
 884         }
 885
 886         rc = -EINVAL;
 887         new_entry = sidtab_search_entry(sidtab, new_sid);
 888         if (!new_entry) {
 889                 pr_err("SELinux: %s: unrecognized SID %u\n",
 890                        __func__, new_sid);
 891                 goto out;
 892         }
 893
 894         rc = 0;
 895         /* type/domain unchanged */
 896         if (old_entry->context.type == new_entry->context.type)
 897                 goto out;
 898
 899         index = new_entry->context.type;
 900         while (true) {
 901                 type = policydb->type_val_to_struct[index - 1];
 902                 BUG_ON(!type);
 903
 904                 /* not bounded anymore */
 905                 rc = -EPERM;
 906                 if (!type->bounds)
 907                         break;
 908
 909                 /* @newsid is bounded by @oldsid */
 910                 rc = 0;
 911                 if (type->bounds == old_entry->context.type)
 912                         break;
 913
 914                 index = type->bounds;
 915         }
 916
 917         if (rc) {
 918                 char *old_name = NULL;
 919                 char *new_name = NULL;
 920                 u32 length;
 921
 922                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 923                                             &old_name, &length) &&
 924                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 925                                             &new_name, &length)) {
 926                         audit_log(audit_context(),
 927                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 928                                   "op=security_bounded_transition "
 929                                   "seresult=denied "
 930                                   "oldcontext=%s newcontext=%s",
 931                                   old_name, new_name);
 932                 }
 933                 kfree(new_name);
 934                 kfree(old_name);
 935         }
 936 out:
 937         read_unlock(&state->ss->policy_rwlock);
 938
 939         return rc;
 940 }
 941
 942 static void avd_init(struct selinux_state *state, struct av_decision *avd)
 943 {
 944         avd->allowed = 0;
 945         avd->auditallow = 0;
 946         avd->auditdeny = 0xffffffff;
 947         avd->seqno = state->ss->latest_granting;
 948         avd->flags = 0;
 949 }
 950
 951 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 952                                         struct avtab_node *node)
 953 {
 954         unsigned int i;
 955
 956         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 957                 if (xpermd->driver != node->datum.u.xperms->driver)
 958                         return;
 959         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 960                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 961                                         xpermd->driver))
 962                         return;
 963         } else {
 964                 BUG();
 965         }
 966
 967         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 968                 xpermd->used |= XPERMS_ALLOWED;
 969                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 970                         memset(xpermd->allowed->p, 0xff,
 971                                         sizeof(xpermd->allowed->p));
 972                 }
 973                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 974                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 975                                 xpermd->allowed->p[i] |=
 976                                         node->datum.u.xperms->perms.p[i];
 977                 }
 978         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 979                 xpermd->used |= XPERMS_AUDITALLOW;
 980                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 981                         memset(xpermd->auditallow->p, 0xff,
 982                                         sizeof(xpermd->auditallow->p));
 983                 }
 984                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 985                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 986                                 xpermd->auditallow->p[i] |=
 987                                         node->datum.u.xperms->perms.p[i];
 988                 }
 989         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 990                 xpermd->used |= XPERMS_DONTAUDIT;
 991                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 992                         memset(xpermd->dontaudit->p, 0xff,
 993                                         sizeof(xpermd->dontaudit->p));
 994                 }
 995                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 996                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 997                                 xpermd->dontaudit->p[i] |=
 998                                         node->datum.u.xperms->perms.p[i];
 999                 }
1000         } else {
1001                 BUG();
1002         }
1003 }
1004
1005 void security_compute_xperms_decision(struct selinux_state *state,
1006                                       u32 ssid,
1007                                       u32 tsid,
1008                                       u16 orig_tclass,
1009                                       u8 driver,
1010                                       struct extended_perms_decision *xpermd)
1011 {
1012         struct policydb *policydb;
1013         struct sidtab *sidtab;
1014         u16 tclass;
1015         struct context *scontext, *tcontext;
1016         struct avtab_key avkey;
1017         struct avtab_node *node;
1018         struct ebitmap *sattr, *tattr;
1019         struct ebitmap_node *snode, *tnode;
1020         unsigned int i, j;
1021
1022         xpermd->driver = driver;
1023         xpermd->used = 0;
1024         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1025         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1026         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1027
1028         read_lock(&state->ss->policy_rwlock);
1029         if (!selinux_initialized(state))
1030                 goto allow;
1031
1032         policydb = &state->ss->policydb;
1033         sidtab = state->ss->sidtab;
1034
1035         scontext = sidtab_search(sidtab, ssid);
1036         if (!scontext) {
1037                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1038                        __func__, ssid);
1039                 goto out;
1040         }
1041
1042         tcontext = sidtab_search(sidtab, tsid);
1043         if (!tcontext) {
1044                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1045                        __func__, tsid);
1046                 goto out;
1047         }
1048
1049         tclass = unmap_class(&state->ss->map, orig_tclass);
1050         if (unlikely(orig_tclass && !tclass)) {
1051                 if (policydb->allow_unknown)
1052                         goto allow;
1053                 goto out;
1054         }
1055
1056
1057         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1058                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1059                 goto out;
1060         }
1061
1062         avkey.target_class = tclass;
1063         avkey.specified = AVTAB_XPERMS;
1064         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1065         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1066         ebitmap_for_each_positive_bit(sattr, snode, i) {
1067                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1068                         avkey.source_type = i + 1;
1069                         avkey.target_type = j + 1;
1070                         for (node = avtab_search_node(&policydb->te_avtab,
1071                                                       &avkey);
1072                              node;
1073                              node = avtab_search_node_next(node, avkey.specified))
1074                                 services_compute_xperms_decision(xpermd, node);
1075
1076                         cond_compute_xperms(&policydb->te_cond_avtab,
1077                                                 &avkey, xpermd);
1078                 }
1079         }
1080 out:
1081         read_unlock(&state->ss->policy_rwlock);
1082         return;
1083 allow:
1084         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1085         goto out;
1086 }
1087
1088 /**
1089  * security_compute_av - Compute access vector decisions.
1090  * @ssid: source security identifier
1091  * @tsid: target security identifier
1092  * @tclass: target security class
1093  * @avd: access vector decisions
1094  * @xperms: extended permissions
1095  *
1096  * Compute a set of access vector decisions based on the
1097  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1098  */
1099 void security_compute_av(struct selinux_state *state,
1100                          u32 ssid,
1101                          u32 tsid,
1102                          u16 orig_tclass,
1103                          struct av_decision *avd,
1104                          struct extended_perms *xperms)
1105 {
1106         struct policydb *policydb;
1107         struct sidtab *sidtab;
1108         u16 tclass;
1109         struct context *scontext = NULL, *tcontext = NULL;
1110
1111         read_lock(&state->ss->policy_rwlock);
1112         avd_init(state, avd);
1113         xperms->len = 0;
1114         if (!selinux_initialized(state))
1115                 goto allow;
1116
1117         policydb = &state->ss->policydb;
1118         sidtab = state->ss->sidtab;
1119
1120         scontext = sidtab_search(sidtab, ssid);
1121         if (!scontext) {
1122                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1123                        __func__, ssid);
1124                 goto out;
1125         }
1126
1127         /* permissive domain? */
1128         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1129                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1130
1131         tcontext = sidtab_search(sidtab, tsid);
1132         if (!tcontext) {
1133                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1134                        __func__, tsid);
1135                 goto out;
1136         }
1137
1138         tclass = unmap_class(&state->ss->map, orig_tclass);
1139         if (unlikely(orig_tclass && !tclass)) {
1140                 if (policydb->allow_unknown)
1141                         goto allow;
1142                 goto out;
1143         }
1144         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1145                                   xperms);
1146         map_decision(&state->ss->map, orig_tclass, avd,
1147                      policydb->allow_unknown);
1148 out:
1149         read_unlock(&state->ss->policy_rwlock);
1150         return;
1151 allow:
1152         avd->allowed = 0xffffffff;
1153         goto out;
1154 }
1155
1156 void security_compute_av_user(struct selinux_state *state,
1157                               u32 ssid,
1158                               u32 tsid,
1159                               u16 tclass,
1160                               struct av_decision *avd)
1161 {
1162         struct policydb *policydb;
1163         struct sidtab *sidtab;
1164         struct context *scontext = NULL, *tcontext = NULL;
1165
1166         read_lock(&state->ss->policy_rwlock);
1167         avd_init(state, avd);
1168         if (!selinux_initialized(state))
1169                 goto allow;
1170
1171         policydb = &state->ss->policydb;
1172         sidtab = state->ss->sidtab;
1173
1174         scontext = sidtab_search(sidtab, ssid);
1175         if (!scontext) {
1176                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1177                        __func__, ssid);
1178                 goto out;
1179         }
1180
1181         /* permissive domain? */
1182         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1183                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1184
1185         tcontext = sidtab_search(sidtab, tsid);
1186         if (!tcontext) {
1187                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1188                        __func__, tsid);
1189                 goto out;
1190         }
1191
1192         if (unlikely(!tclass)) {
1193                 if (policydb->allow_unknown)
1194                         goto allow;
1195                 goto out;
1196         }
1197
1198         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1199                                   NULL);
1200  out:
1201         read_unlock(&state->ss->policy_rwlock);
1202         return;
1203 allow:
1204         avd->allowed = 0xffffffff;
1205         goto out;
1206 }
1207
1208 /*
1209  * Write the security context string representation of
1210  * the context structure `context' into a dynamically
1211  * allocated string of the correct size.  Set `*scontext'
1212  * to point to this string and set `*scontext_len' to
1213  * the length of the string.
1214  */
1215 static int context_struct_to_string(struct policydb *p,
1216                                     struct context *context,
1217                                     char **scontext, u32 *scontext_len)
1218 {
1219         char *scontextp;
1220
1221         if (scontext)
1222                 *scontext = NULL;
1223         *scontext_len = 0;
1224
1225         if (context->len) {
1226                 *scontext_len = context->len;
1227                 if (scontext) {
1228                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1229                         if (!(*scontext))
1230                                 return -ENOMEM;
1231                 }
1232                 return 0;
1233         }
1234
1235         /* Compute the size of the context. */
1236         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1237         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1238         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1239         *scontext_len += mls_compute_context_len(p, context);
1240
1241         if (!scontext)
1242                 return 0;
1243
1244         /* Allocate space for the context; caller must free this space. */
1245         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1246         if (!scontextp)
1247                 return -ENOMEM;
1248         *scontext = scontextp;
1249
1250         /*
1251          * Copy the user name, role name and type name into the context.
1252          */
1253         scontextp += sprintf(scontextp, "%s:%s:%s",
1254                 sym_name(p, SYM_USERS, context->user - 1),
1255                 sym_name(p, SYM_ROLES, context->role - 1),
1256                 sym_name(p, SYM_TYPES, context->type - 1));
1257
1258         mls_sid_to_context(p, context, &scontextp);
1259
1260         *scontextp = 0;
1261
1262         return 0;
1263 }
1264
1265 static int sidtab_entry_to_string(struct policydb *p,
1266                                   struct sidtab *sidtab,
1267                                   struct sidtab_entry *entry,
1268                                   char **scontext, u32 *scontext_len)
1269 {
1270         int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1271
1272         if (rc != -ENOENT)
1273                 return rc;
1274
1275         rc = context_struct_to_string(p, &entry->context, scontext,
1276                                       scontext_len);
1277         if (!rc && scontext)
1278                 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1279         return rc;
1280 }
1281
1282 #include "initial_sid_to_string.h"
1283
1284 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1285 {
1286         int rc;
1287
1288         if (!selinux_initialized(state)) {
1289                 pr_err("SELinux: %s:  called before initial load_policy\n",
1290                        __func__);
1291                 return -EINVAL;
1292         }
1293
1294         read_lock(&state->ss->policy_rwlock);
1295         rc = sidtab_hash_stats(state->ss->sidtab, page);
1296         read_unlock(&state->ss->policy_rwlock);
1297
1298         return rc;
1299 }
1300
1301 const char *security_get_initial_sid_context(u32 sid)
1302 {
1303         if (unlikely(sid > SECINITSID_NUM))
1304                 return NULL;
1305         return initial_sid_to_string[sid];
1306 }
1307
1308 static int security_sid_to_context_core(struct selinux_state *state,
1309                                         u32 sid, char **scontext,
1310                                         u32 *scontext_len, int force,
1311                                         int only_invalid)
1312 {
1313         struct policydb *policydb;
1314         struct sidtab *sidtab;
1315         struct sidtab_entry *entry;
1316         int rc = 0;
1317
1318         if (scontext)
1319                 *scontext = NULL;
1320         *scontext_len  = 0;
1321
1322         if (!selinux_initialized(state)) {
1323                 if (sid <= SECINITSID_NUM) {
1324                         char *scontextp;
1325                         const char *s = initial_sid_to_string[sid];
1326
1327                         if (!s)
1328                                 return -EINVAL;
1329                         *scontext_len = strlen(s) + 1;
1330                         if (!scontext)
1331                                 return 0;
1332                         scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1333                         if (!scontextp)
1334                                 return -ENOMEM;
1335                         *scontext = scontextp;
1336                         return 0;
1337                 }
1338                 pr_err("SELinux: %s:  called before initial "
1339                        "load_policy on unknown SID %d\n", __func__, sid);
1340                 return -EINVAL;
1341         }
1342         read_lock(&state->ss->policy_rwlock);
1343         policydb = &state->ss->policydb;
1344         sidtab = state->ss->sidtab;
1345
1346         if (force)
1347                 entry = sidtab_search_entry_force(sidtab, sid);
1348         else
1349                 entry = sidtab_search_entry(sidtab, sid);
1350         if (!entry) {
1351                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1352                         __func__, sid);
1353                 rc = -EINVAL;
1354                 goto out_unlock;
1355         }
1356         if (only_invalid && !entry->context.len)
1357                 goto out_unlock;
1358
1359         rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1360                                     scontext_len);
1361
1362 out_unlock:
1363         read_unlock(&state->ss->policy_rwlock);
1364         return rc;
1365
1366 }
1367
1368 /**
1369  * security_sid_to_context - Obtain a context for a given SID.
1370  * @sid: security identifier, SID
1371  * @scontext: security context
1372  * @scontext_len: length in bytes
1373  *
1374  * Write the string representation of the context associated with @sid
1375  * into a dynamically allocated string of the correct size.  Set @scontext
1376  * to point to this string and set @scontext_len to the length of the string.
1377  */
1378 int security_sid_to_context(struct selinux_state *state,
1379                             u32 sid, char **scontext, u32 *scontext_len)
1380 {
1381         return security_sid_to_context_core(state, sid, scontext,
1382                                             scontext_len, 0, 0);
1383 }
1384
1385 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1386                                   char **scontext, u32 *scontext_len)
1387 {
1388         return security_sid_to_context_core(state, sid, scontext,
1389                                             scontext_len, 1, 0);
1390 }
1391
1392 /**
1393  * security_sid_to_context_inval - Obtain a context for a given SID if it
1394  *                                 is invalid.
1395  * @sid: security identifier, SID
1396  * @scontext: security context
1397  * @scontext_len: length in bytes
1398  *
1399  * Write the string representation of the context associated with @sid
1400  * into a dynamically allocated string of the correct size, but only if the
1401  * context is invalid in the current policy.  Set @scontext to point to
1402  * this string (or NULL if the context is valid) and set @scontext_len to
1403  * the length of the string (or 0 if the context is valid).
1404  */
1405 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1406                                   char **scontext, u32 *scontext_len)
1407 {
1408         return security_sid_to_context_core(state, sid, scontext,
1409                                             scontext_len, 1, 1);
1410 }
1411
1412 /*
1413  * Caveat:  Mutates scontext.
1414  */
1415 static int string_to_context_struct(struct policydb *pol,
1416                                     struct sidtab *sidtabp,
1417                                     char *scontext,
1418                                     struct context *ctx,
1419                                     u32 def_sid)
1420 {
1421         struct role_datum *role;
1422         struct type_datum *typdatum;
1423         struct user_datum *usrdatum;
1424         char *scontextp, *p, oldc;
1425         int rc = 0;
1426
1427         context_init(ctx);
1428
1429         /* Parse the security context. */
1430
1431         rc = -EINVAL;
1432         scontextp = (char *) scontext;
1433
1434         /* Extract the user. */
1435         p = scontextp;
1436         while (*p && *p != ':')
1437                 p++;
1438
1439         if (*p == 0)
1440                 goto out;
1441
1442         *p++ = 0;
1443
1444         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1445         if (!usrdatum)
1446                 goto out;
1447
1448         ctx->user = usrdatum->value;
1449
1450         /* Extract role. */
1451         scontextp = p;
1452         while (*p && *p != ':')
1453                 p++;
1454
1455         if (*p == 0)
1456                 goto out;
1457
1458         *p++ = 0;
1459
1460         role = hashtab_search(pol->p_roles.table, scontextp);
1461         if (!role)
1462                 goto out;
1463         ctx->role = role->value;
1464
1465         /* Extract type. */
1466         scontextp = p;
1467         while (*p && *p != ':')
1468                 p++;
1469         oldc = *p;
1470         *p++ = 0;
1471
1472         typdatum = hashtab_search(pol->p_types.table, scontextp);
1473         if (!typdatum || typdatum->attribute)
1474                 goto out;
1475
1476         ctx->type = typdatum->value;
1477
1478         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1479         if (rc)
1480                 goto out;
1481
1482         /* Check the validity of the new context. */
1483         rc = -EINVAL;
1484         if (!policydb_context_isvalid(pol, ctx))
1485                 goto out;
1486         rc = 0;
1487 out:
1488         if (rc)
1489                 context_destroy(ctx);
1490         return rc;
1491 }
1492
1493 int context_add_hash(struct policydb *policydb,
1494                      struct context *context)
1495 {
1496         int rc;
1497         char *str;
1498         int len;
1499
1500         if (context->str) {
1501                 context->hash = context_compute_hash(context->str);
1502         } else {
1503                 rc = context_struct_to_string(policydb, context,
1504                                               &str, &len);
1505                 if (rc)
1506                         return rc;
1507                 context->hash = context_compute_hash(str);
1508                 kfree(str);
1509         }
1510         return 0;
1511 }
1512
1513 static int context_struct_to_sid(struct selinux_state *state,
1514                                  struct context *context, u32 *sid)
1515 {
1516         int rc;
1517         struct sidtab *sidtab = state->ss->sidtab;
1518         struct policydb *policydb = &state->ss->policydb;
1519
1520         if (!context->hash) {
1521                 rc = context_add_hash(policydb, context);
1522                 if (rc)
1523                         return rc;
1524         }
1525
1526         return sidtab_context_to_sid(sidtab, context, sid);
1527 }
1528
1529 static int security_context_to_sid_core(struct selinux_state *state,
1530                                         const char *scontext, u32 scontext_len,
1531                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1532                                         int force)
1533 {
1534         struct policydb *policydb;
1535         struct sidtab *sidtab;
1536         char *scontext2, *str = NULL;
1537         struct context context;
1538         int rc = 0;
1539
1540         /* An empty security context is never valid. */
1541         if (!scontext_len)
1542                 return -EINVAL;
1543
1544         /* Copy the string to allow changes and ensure a NUL terminator */
1545         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1546         if (!scontext2)
1547                 return -ENOMEM;
1548
1549         if (!selinux_initialized(state)) {
1550                 int i;
1551
1552                 for (i = 1; i < SECINITSID_NUM; i++) {
1553                         const char *s = initial_sid_to_string[i];
1554
1555                         if (s && !strcmp(s, scontext2)) {
1556                                 *sid = i;
1557                                 goto out;
1558                         }
1559                 }
1560                 *sid = SECINITSID_KERNEL;
1561                 goto out;
1562         }
1563         *sid = SECSID_NULL;
1564
1565         if (force) {
1566                 /* Save another copy for storing in uninterpreted form */
1567                 rc = -ENOMEM;
1568                 str = kstrdup(scontext2, gfp_flags);
1569                 if (!str)
1570                         goto out;
1571         }
1572         read_lock(&state->ss->policy_rwlock);
1573         policydb = &state->ss->policydb;
1574         sidtab = state->ss->sidtab;
1575         rc = string_to_context_struct(policydb, sidtab, scontext2,
1576                                       &context, def_sid);
1577         if (rc == -EINVAL && force) {
1578                 context.str = str;
1579                 context.len = strlen(str) + 1;
1580                 str = NULL;
1581         } else if (rc)
1582                 goto out_unlock;
1583         rc = context_struct_to_sid(state, &context, sid);
1584         context_destroy(&context);
1585 out_unlock:
1586         read_unlock(&state->ss->policy_rwlock);
1587 out:
1588         kfree(scontext2);
1589         kfree(str);
1590         return rc;
1591 }
1592
1593 /**
1594  * security_context_to_sid - Obtain a SID for a given security context.
1595  * @scontext: security context
1596  * @scontext_len: length in bytes
1597  * @sid: security identifier, SID
1598  * @gfp: context for the allocation
1599  *
1600  * Obtains a SID associated with the security context that
1601  * has the string representation specified by @scontext.
1602  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1603  * memory is available, or 0 on success.
1604  */
1605 int security_context_to_sid(struct selinux_state *state,
1606                             const char *scontext, u32 scontext_len, u32 *sid,
1607                             gfp_t gfp)
1608 {
1609         return security_context_to_sid_core(state, scontext, scontext_len,
1610                                             sid, SECSID_NULL, gfp, 0);
1611 }
1612
1613 int security_context_str_to_sid(struct selinux_state *state,
1614                                 const char *scontext, u32 *sid, gfp_t gfp)
1615 {
1616         return security_context_to_sid(state, scontext, strlen(scontext),
1617                                        sid, gfp);
1618 }
1619
1620 /**
1621  * security_context_to_sid_default - Obtain a SID for a given security context,
1622  * falling back to specified default if needed.
1623  *
1624  * @scontext: security context
1625  * @scontext_len: length in bytes
1626  * @sid: security identifier, SID
1627  * @def_sid: default SID to assign on error
1628  *
1629  * Obtains a SID associated with the security context that
1630  * has the string representation specified by @scontext.
1631  * The default SID is passed to the MLS layer to be used to allow
1632  * kernel labeling of the MLS field if the MLS field is not present
1633  * (for upgrading to MLS without full relabel).
1634  * Implicitly forces adding of the context even if it cannot be mapped yet.
1635  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1636  * memory is available, or 0 on success.
1637  */
1638 int security_context_to_sid_default(struct selinux_state *state,
1639                                     const char *scontext, u32 scontext_len,
1640                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1641 {
1642         return security_context_to_sid_core(state, scontext, scontext_len,
1643                                             sid, def_sid, gfp_flags, 1);
1644 }
1645
1646 int security_context_to_sid_force(struct selinux_state *state,
1647                                   const char *scontext, u32 scontext_len,
1648                                   u32 *sid)
1649 {
1650         return security_context_to_sid_core(state, scontext, scontext_len,
1651                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1652 }
1653
1654 static int compute_sid_handle_invalid_context(
1655         struct selinux_state *state,
1656         struct sidtab_entry *sentry,
1657         struct sidtab_entry *tentry,
1658         u16 tclass,
1659         struct context *newcontext)
1660 {
1661         struct policydb *policydb = &state->ss->policydb;
1662         struct sidtab *sidtab = state->ss->sidtab;
1663         char *s = NULL, *t = NULL, *n = NULL;
1664         u32 slen, tlen, nlen;
1665         struct audit_buffer *ab;
1666
1667         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1668                 goto out;
1669         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1670                 goto out;
1671         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1672                 goto out;
1673         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1674         audit_log_format(ab,
1675                          "op=security_compute_sid invalid_context=");
1676         /* no need to record the NUL with untrusted strings */
1677         audit_log_n_untrustedstring(ab, n, nlen - 1);
1678         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1679                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1680         audit_log_end(ab);
1681 out:
1682         kfree(s);
1683         kfree(t);
1684         kfree(n);
1685         if (!enforcing_enabled(state))
1686                 return 0;
1687         return -EACCES;
1688 }
1689
1690 static void filename_compute_type(struct policydb *policydb,
1691                                   struct context *newcontext,
1692                                   u32 stype, u32 ttype, u16 tclass,
1693                                   const char *objname)
1694 {
1695         struct filename_trans_key ft;
1696         struct filename_trans_datum *datum;
1697
1698         /*
1699          * Most filename trans rules are going to live in specific directories
1700          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1701          * if the ttype does not contain any rules.
1702          */
1703         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1704                 return;
1705
1706         ft.ttype = ttype;
1707         ft.tclass = tclass;
1708         ft.name = objname;
1709
1710         datum = hashtab_search(policydb->filename_trans, &ft);
1711         while (datum) {
1712                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1713                         newcontext->type = datum->otype;
1714                         return;
1715                 }
1716                 datum = datum->next;
1717         }
1718 }
1719
1720 static int security_compute_sid(struct selinux_state *state,
1721                                 u32 ssid,
1722                                 u32 tsid,
1723                                 u16 orig_tclass,
1724                                 u32 specified,
1725                                 const char *objname,
1726                                 u32 *out_sid,
1727                                 bool kern)
1728 {
1729         struct policydb *policydb;
1730         struct sidtab *sidtab;
1731         struct class_datum *cladatum = NULL;
1732         struct context *scontext, *tcontext, newcontext;
1733         struct sidtab_entry *sentry, *tentry;
1734         struct role_trans *roletr = NULL;
1735         struct avtab_key avkey;
1736         struct avtab_datum *avdatum;
1737         struct avtab_node *node;
1738         u16 tclass;
1739         int rc = 0;
1740         bool sock;
1741
1742         if (!selinux_initialized(state)) {
1743                 switch (orig_tclass) {
1744                 case SECCLASS_PROCESS: /* kernel value */
1745                         *out_sid = ssid;
1746                         break;
1747                 default:
1748                         *out_sid = tsid;
1749                         break;
1750                 }
1751                 goto out;
1752         }
1753
1754         context_init(&newcontext);
1755
1756         read_lock(&state->ss->policy_rwlock);
1757
1758         if (kern) {
1759                 tclass = unmap_class(&state->ss->map, orig_tclass);
1760                 sock = security_is_socket_class(orig_tclass);
1761         } else {
1762                 tclass = orig_tclass;
1763                 sock = security_is_socket_class(map_class(&state->ss->map,
1764                                                           tclass));
1765         }
1766
1767         policydb = &state->ss->policydb;
1768         sidtab = state->ss->sidtab;
1769
1770         sentry = sidtab_search_entry(sidtab, ssid);
1771         if (!sentry) {
1772                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1773                        __func__, ssid);
1774                 rc = -EINVAL;
1775                 goto out_unlock;
1776         }
1777         tentry = sidtab_search_entry(sidtab, tsid);
1778         if (!tentry) {
1779                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1780                        __func__, tsid);
1781                 rc = -EINVAL;
1782                 goto out_unlock;
1783         }
1784
1785         scontext = &sentry->context;
1786         tcontext = &tentry->context;
1787
1788         if (tclass && tclass <= policydb->p_classes.nprim)
1789                 cladatum = policydb->class_val_to_struct[tclass - 1];
1790
1791         /* Set the user identity. */
1792         switch (specified) {
1793         case AVTAB_TRANSITION:
1794         case AVTAB_CHANGE:
1795                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1796                         newcontext.user = tcontext->user;
1797                 } else {
1798                         /* notice this gets both DEFAULT_SOURCE and unset */
1799                         /* Use the process user identity. */
1800                         newcontext.user = scontext->user;
1801                 }
1802                 break;
1803         case AVTAB_MEMBER:
1804                 /* Use the related object owner. */
1805                 newcontext.user = tcontext->user;
1806                 break;
1807         }
1808
1809         /* Set the role to default values. */
1810         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1811                 newcontext.role = scontext->role;
1812         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1813                 newcontext.role = tcontext->role;
1814         } else {
1815                 if ((tclass == policydb->process_class) || sock)
1816                         newcontext.role = scontext->role;
1817                 else
1818                         newcontext.role = OBJECT_R_VAL;
1819         }
1820
1821         /* Set the type to default values. */
1822         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1823                 newcontext.type = scontext->type;
1824         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1825                 newcontext.type = tcontext->type;
1826         } else {
1827                 if ((tclass == policydb->process_class) || sock) {
1828                         /* Use the type of process. */
1829                         newcontext.type = scontext->type;
1830                 } else {
1831                         /* Use the type of the related object. */
1832                         newcontext.type = tcontext->type;
1833                 }
1834         }
1835
1836         /* Look for a type transition/member/change rule. */
1837         avkey.source_type = scontext->type;
1838         avkey.target_type = tcontext->type;
1839         avkey.target_class = tclass;
1840         avkey.specified = specified;
1841         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1842
1843         /* If no permanent rule, also check for enabled conditional rules */
1844         if (!avdatum) {
1845                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1846                 for (; node; node = avtab_search_node_next(node, specified)) {
1847                         if (node->key.specified & AVTAB_ENABLED) {
1848                                 avdatum = &node->datum;
1849                                 break;
1850                         }
1851                 }
1852         }
1853
1854         if (avdatum) {
1855                 /* Use the type from the type transition/member/change rule. */
1856                 newcontext.type = avdatum->u.data;
1857         }
1858
1859         /* if we have a objname this is a file trans check so check those rules */
1860         if (objname)
1861                 filename_compute_type(policydb, &newcontext, scontext->type,
1862                                       tcontext->type, tclass, objname);
1863
1864         /* Check for class-specific changes. */
1865         if (specified & AVTAB_TRANSITION) {
1866                 /* Look for a role transition rule. */
1867                 for (roletr = policydb->role_tr; roletr;
1868                      roletr = roletr->next) {
1869                         if ((roletr->role == scontext->role) &&
1870                             (roletr->type == tcontext->type) &&
1871                             (roletr->tclass == tclass)) {
1872                                 /* Use the role transition rule. */
1873                                 newcontext.role = roletr->new_role;
1874                                 break;
1875                         }
1876                 }
1877         }
1878
1879         /* Set the MLS attributes.
1880            This is done last because it may allocate memory. */
1881         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1882                              &newcontext, sock);
1883         if (rc)
1884                 goto out_unlock;
1885
1886         /* Check the validity of the context. */
1887         if (!policydb_context_isvalid(policydb, &newcontext)) {
1888                 rc = compute_sid_handle_invalid_context(state, sentry, tentry,
1889                                                         tclass, &newcontext);
1890                 if (rc)
1891                         goto out_unlock;
1892         }
1893         /* Obtain the sid for the context. */
1894         rc = context_struct_to_sid(state, &newcontext, out_sid);
1895 out_unlock:
1896         read_unlock(&state->ss->policy_rwlock);
1897         context_destroy(&newcontext);
1898 out:
1899         return rc;
1900 }
1901
1902 /**
1903  * security_transition_sid - Compute the SID for a new subject/object.
1904  * @ssid: source security identifier
1905  * @tsid: target security identifier
1906  * @tclass: target security class
1907  * @out_sid: security identifier for new subject/object
1908  *
1909  * Compute a SID to use for labeling a new subject or object in the
1910  * class @tclass based on a SID pair (@ssid, @tsid).
1911  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1912  * if insufficient memory is available, or %0 if the new SID was
1913  * computed successfully.
1914  */
1915 int security_transition_sid(struct selinux_state *state,
1916                             u32 ssid, u32 tsid, u16 tclass,
1917                             const struct qstr *qstr, u32 *out_sid)
1918 {
1919         return security_compute_sid(state, ssid, tsid, tclass,
1920                                     AVTAB_TRANSITION,
1921                                     qstr ? qstr->name : NULL, out_sid, true);
1922 }
1923
1924 int security_transition_sid_user(struct selinux_state *state,
1925                                  u32 ssid, u32 tsid, u16 tclass,
1926                                  const char *objname, u32 *out_sid)
1927 {
1928         return security_compute_sid(state, ssid, tsid, tclass,
1929                                     AVTAB_TRANSITION,
1930                                     objname, out_sid, false);
1931 }
1932
1933 /**
1934  * security_member_sid - Compute the SID for member selection.
1935  * @ssid: source security identifier
1936  * @tsid: target security identifier
1937  * @tclass: target security class
1938  * @out_sid: security identifier for selected member
1939  *
1940  * Compute a SID to use when selecting a member of a polyinstantiated
1941  * object of class @tclass based on a SID pair (@ssid, @tsid).
1942  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1943  * if insufficient memory is available, or %0 if the SID was
1944  * computed successfully.
1945  */
1946 int security_member_sid(struct selinux_state *state,
1947                         u32 ssid,
1948                         u32 tsid,
1949                         u16 tclass,
1950                         u32 *out_sid)
1951 {
1952         return security_compute_sid(state, ssid, tsid, tclass,
1953                                     AVTAB_MEMBER, NULL,
1954                                     out_sid, false);
1955 }
1956
1957 /**
1958  * security_change_sid - Compute the SID for object relabeling.
1959  * @ssid: source security identifier
1960  * @tsid: target security identifier
1961  * @tclass: target security class
1962  * @out_sid: security identifier for selected member
1963  *
1964  * Compute a SID to use for relabeling an object of class @tclass
1965  * based on a SID pair (@ssid, @tsid).
1966  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1967  * if insufficient memory is available, or %0 if the SID was
1968  * computed successfully.
1969  */
1970 int security_change_sid(struct selinux_state *state,
1971                         u32 ssid,
1972                         u32 tsid,
1973                         u16 tclass,
1974                         u32 *out_sid)
1975 {
1976         return security_compute_sid(state,
1977                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1978                                     out_sid, false);
1979 }
1980
1981 static inline int convert_context_handle_invalid_context(
1982         struct selinux_state *state,
1983         struct context *context)
1984 {
1985         struct policydb *policydb = &state->ss->policydb;
1986         char *s;
1987         u32 len;
1988
1989         if (enforcing_enabled(state))
1990                 return -EINVAL;
1991
1992         if (!context_struct_to_string(policydb, context, &s, &len)) {
1993                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
1994                         s);
1995                 kfree(s);
1996         }
1997         return 0;
1998 }
1999
2000 struct convert_context_args {
2001         struct selinux_state *state;
2002         struct policydb *oldp;
2003         struct policydb *newp;
2004 };
2005
2006 /*
2007  * Convert the values in the security context
2008  * structure `oldc' from the values specified
2009  * in the policy `p->oldp' to the values specified
2010  * in the policy `p->newp', storing the new context
2011  * in `newc'.  Verify that the context is valid
2012  * under the new policy.
2013  */
2014 static int convert_context(struct context *oldc, struct context *newc, void *p)
2015 {
2016         struct convert_context_args *args;
2017         struct ocontext *oc;
2018         struct role_datum *role;
2019         struct type_datum *typdatum;
2020         struct user_datum *usrdatum;
2021         char *s;
2022         u32 len;
2023         int rc;
2024
2025         args = p;
2026
2027         if (oldc->str) {
2028                 s = kstrdup(oldc->str, GFP_KERNEL);
2029                 if (!s)
2030                         return -ENOMEM;
2031
2032                 rc = string_to_context_struct(args->newp, NULL, s,
2033                                               newc, SECSID_NULL);
2034                 if (rc == -EINVAL) {
2035                         /*
2036                          * Retain string representation for later mapping.
2037                          *
2038                          * IMPORTANT: We need to copy the contents of oldc->str
2039                          * back into s again because string_to_context_struct()
2040                          * may have garbled it.
2041                          */
2042                         memcpy(s, oldc->str, oldc->len);
2043                         context_init(newc);
2044                         newc->str = s;
2045                         newc->len = oldc->len;
2046                         newc->hash = oldc->hash;
2047                         return 0;
2048                 }
2049                 kfree(s);
2050                 if (rc) {
2051                         /* Other error condition, e.g. ENOMEM. */
2052                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2053                                oldc->str, -rc);
2054                         return rc;
2055                 }
2056                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2057                         oldc->str);
2058                 return 0;
2059         }
2060
2061         context_init(newc);
2062
2063         /* Convert the user. */
2064         rc = -EINVAL;
2065         usrdatum = hashtab_search(args->newp->p_users.table,
2066                                   sym_name(args->oldp,
2067                                            SYM_USERS, oldc->user - 1));
2068         if (!usrdatum)
2069                 goto bad;
2070         newc->user = usrdatum->value;
2071
2072         /* Convert the role. */
2073         rc = -EINVAL;
2074         role = hashtab_search(args->newp->p_roles.table,
2075                               sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2076         if (!role)
2077                 goto bad;
2078         newc->role = role->value;
2079
2080         /* Convert the type. */
2081         rc = -EINVAL;
2082         typdatum = hashtab_search(args->newp->p_types.table,
2083                                   sym_name(args->oldp,
2084                                            SYM_TYPES, oldc->type - 1));
2085         if (!typdatum)
2086                 goto bad;
2087         newc->type = typdatum->value;
2088
2089         /* Convert the MLS fields if dealing with MLS policies */
2090         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2091                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2092                 if (rc)
2093                         goto bad;
2094         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2095                 /*
2096                  * Switching between non-MLS and MLS policy:
2097                  * ensure that the MLS fields of the context for all
2098                  * existing entries in the sidtab are filled in with a
2099                  * suitable default value, likely taken from one of the
2100                  * initial SIDs.
2101                  */
2102                 oc = args->newp->ocontexts[OCON_ISID];
2103                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2104                         oc = oc->next;
2105                 rc = -EINVAL;
2106                 if (!oc) {
2107                         pr_err("SELinux:  unable to look up"
2108                                 " the initial SIDs list\n");
2109                         goto bad;
2110                 }
2111                 rc = mls_range_set(newc, &oc->context[0].range);
2112                 if (rc)
2113                         goto bad;
2114         }
2115
2116         /* Check the validity of the new context. */
2117         if (!policydb_context_isvalid(args->newp, newc)) {
2118                 rc = convert_context_handle_invalid_context(args->state, oldc);
2119                 if (rc)
2120                         goto bad;
2121         }
2122
2123         rc = context_add_hash(args->newp, newc);
2124         if (rc)
2125                 goto bad;
2126
2127         return 0;
2128 bad:
2129         /* Map old representation to string and save it. */
2130         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2131         if (rc)
2132                 return rc;
2133         context_destroy(newc);
2134         newc->str = s;
2135         newc->len = len;
2136         newc->hash = context_compute_hash(s);
2137         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2138                 newc->str);
2139         return 0;
2140 }
2141
2142 static void security_load_policycaps(struct selinux_state *state)
2143 {
2144         struct policydb *p = &state->ss->policydb;
2145         unsigned int i;
2146         struct ebitmap_node *node;
2147
2148         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2149                 state->policycap[i] = ebitmap_get_bit(&p->policycaps, i);
2150
2151         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2152                 pr_info("SELinux:  policy capability %s=%d\n",
2153                         selinux_policycap_names[i],
2154                         ebitmap_get_bit(&p->policycaps, i));
2155
2156         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2157                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2158                         pr_info("SELinux:  unknown policy capability %u\n",
2159                                 i);
2160         }
2161 }
2162
2163 static int security_preserve_bools(struct selinux_state *state,
2164                                    struct policydb *newpolicydb);
2165
2166 /**
2167  * security_load_policy - Load a security policy configuration.
2168  * @data: binary policy data
2169  * @len: length of data in bytes
2170  *
2171  * Load a new set of security policy configuration data,
2172  * validate it and convert the SID table as necessary.
2173  * This function will flush the access vector cache after
2174  * loading the new policy.
2175  */
2176 int security_load_policy(struct selinux_state *state, void *data, size_t len)
2177 {
2178         struct policydb *policydb;
2179         struct sidtab *oldsidtab, *newsidtab;
2180         struct policydb *oldpolicydb, *newpolicydb;
2181         struct selinux_mapping *oldmapping;
2182         struct selinux_map newmap;
2183         struct sidtab_convert_params convert_params;
2184         struct convert_context_args args;
2185         u32 seqno;
2186         int rc = 0;
2187         struct policy_file file = { data, len }, *fp = &file;
2188
2189         policydb = &state->ss->policydb;
2190
2191         newsidtab = kmalloc(sizeof(*newsidtab), GFP_KERNEL);
2192         if (!newsidtab)
2193                 return -ENOMEM;
2194
2195         if (!selinux_initialized(state)) {
2196                 rc = policydb_read(policydb, fp);
2197                 if (rc) {
2198                         kfree(newsidtab);
2199                         return rc;
2200                 }
2201
2202                 policydb->len = len;
2203                 rc = selinux_set_mapping(policydb, secclass_map,
2204                                          &state->ss->map);
2205                 if (rc) {
2206                         kfree(newsidtab);
2207                         policydb_destroy(policydb);
2208                         return rc;
2209                 }
2210
2211                 rc = policydb_load_isids(policydb, newsidtab);
2212                 if (rc) {
2213                         kfree(newsidtab);
2214                         policydb_destroy(policydb);
2215                         return rc;
2216                 }
2217
2218                 state->ss->sidtab = newsidtab;
2219                 security_load_policycaps(state);
2220                 selinux_mark_initialized(state);
2221                 seqno = ++state->ss->latest_granting;
2222                 selinux_complete_init();
2223                 avc_ss_reset(state->avc, seqno);
2224                 selnl_notify_policyload(seqno);
2225                 selinux_status_update_policyload(state, seqno);
2226                 selinux_netlbl_cache_invalidate();
2227                 selinux_xfrm_notify_policyload();
2228                 return 0;
2229         }
2230
2231         oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL);
2232         if (!oldpolicydb) {
2233                 kfree(newsidtab);
2234                 return -ENOMEM;
2235         }
2236         newpolicydb = oldpolicydb + 1;
2237
2238         rc = policydb_read(newpolicydb, fp);
2239         if (rc) {
2240                 kfree(newsidtab);
2241                 goto out;
2242         }
2243
2244         newpolicydb->len = len;
2245         /* If switching between different policy types, log MLS status */
2246         if (policydb->mls_enabled && !newpolicydb->mls_enabled)
2247                 pr_info("SELinux: Disabling MLS support...\n");
2248         else if (!policydb->mls_enabled && newpolicydb->mls_enabled)
2249                 pr_info("SELinux: Enabling MLS support...\n");
2250
2251         rc = policydb_load_isids(newpolicydb, newsidtab);
2252         if (rc) {
2253                 pr_err("SELinux:  unable to load the initial SIDs\n");
2254                 policydb_destroy(newpolicydb);
2255                 kfree(newsidtab);
2256                 goto out;
2257         }
2258
2259         rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap);
2260         if (rc)
2261                 goto err;
2262
2263         rc = security_preserve_bools(state, newpolicydb);
2264         if (rc) {
2265                 pr_err("SELinux:  unable to preserve booleans\n");
2266                 goto err;
2267         }
2268
2269         oldsidtab = state->ss->sidtab;
2270
2271         /*
2272          * Convert the internal representations of contexts
2273          * in the new SID table.
2274          */
2275         args.state = state;
2276         args.oldp = policydb;
2277         args.newp = newpolicydb;
2278
2279         convert_params.func = convert_context;
2280         convert_params.args = &args;
2281         convert_params.target = newsidtab;
2282
2283         rc = sidtab_convert(oldsidtab, &convert_params);
2284         if (rc) {
2285                 pr_err("SELinux:  unable to convert the internal"
2286                         " representation of contexts in the new SID"
2287                         " table\n");
2288                 goto err;
2289         }
2290
2291         /* Save the old policydb and SID table to free later. */
2292         memcpy(oldpolicydb, policydb, sizeof(*policydb));
2293
2294         /* Install the new policydb and SID table. */
2295         write_lock_irq(&state->ss->policy_rwlock);
2296         memcpy(policydb, newpolicydb, sizeof(*policydb));
2297         state->ss->sidtab = newsidtab;
2298         security_load_policycaps(state);
2299         oldmapping = state->ss->map.mapping;
2300         state->ss->map.mapping = newmap.mapping;
2301         state->ss->map.size = newmap.size;
2302         seqno = ++state->ss->latest_granting;
2303         write_unlock_irq(&state->ss->policy_rwlock);
2304
2305         /* Free the old policydb and SID table. */
2306         policydb_destroy(oldpolicydb);
2307         sidtab_destroy(oldsidtab);
2308         kfree(oldsidtab);
2309         kfree(oldmapping);
2310
2311         avc_ss_reset(state->avc, seqno);
2312         selnl_notify_policyload(seqno);
2313         selinux_status_update_policyload(state, seqno);
2314         selinux_netlbl_cache_invalidate();
2315         selinux_xfrm_notify_policyload();
2316
2317         rc = 0;
2318         goto out;
2319
2320 err:
2321         kfree(newmap.mapping);
2322         sidtab_destroy(newsidtab);
2323         kfree(newsidtab);
2324         policydb_destroy(newpolicydb);
2325
2326 out:
2327         kfree(oldpolicydb);
2328         return rc;
2329 }
2330
2331 size_t security_policydb_len(struct selinux_state *state)
2332 {
2333         struct policydb *p = &state->ss->policydb;
2334         size_t len;
2335
2336         read_lock(&state->ss->policy_rwlock);
2337         len = p->len;
2338         read_unlock(&state->ss->policy_rwlock);
2339
2340         return len;
2341 }
2342
2343 /**
2344  * security_port_sid - Obtain the SID for a port.
2345  * @protocol: protocol number
2346  * @port: port number
2347  * @out_sid: security identifier
2348  */
2349 int security_port_sid(struct selinux_state *state,
2350                       u8 protocol, u16 port, u32 *out_sid)
2351 {
2352         struct policydb *policydb;
2353         struct ocontext *c;
2354         int rc = 0;
2355
2356         read_lock(&state->ss->policy_rwlock);
2357
2358         policydb = &state->ss->policydb;
2359
2360         c = policydb->ocontexts[OCON_PORT];
2361         while (c) {
2362                 if (c->u.port.protocol == protocol &&
2363                     c->u.port.low_port <= port &&
2364                     c->u.port.high_port >= port)
2365                         break;
2366                 c = c->next;
2367         }
2368
2369         if (c) {
2370                 if (!c->sid[0]) {
2371                         rc = context_struct_to_sid(state, &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_PORT;
2379         }
2380
2381 out:
2382         read_unlock(&state->ss->policy_rwlock);
2383         return rc;
2384 }
2385
2386 /**
2387  * security_pkey_sid - Obtain the SID for a pkey.
2388  * @subnet_prefix: Subnet Prefix
2389  * @pkey_num: pkey number
2390  * @out_sid: security identifier
2391  */
2392 int security_ib_pkey_sid(struct selinux_state *state,
2393                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2394 {
2395         struct policydb *policydb;
2396         struct ocontext *c;
2397         int rc = 0;
2398
2399         read_lock(&state->ss->policy_rwlock);
2400
2401         policydb = &state->ss->policydb;
2402
2403         c = policydb->ocontexts[OCON_IBPKEY];
2404         while (c) {
2405                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2406                     c->u.ibpkey.high_pkey >= pkey_num &&
2407                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2408                         break;
2409
2410                 c = c->next;
2411         }
2412
2413         if (c) {
2414                 if (!c->sid[0]) {
2415                         rc = context_struct_to_sid(state,
2416                                                    &c->context[0],
2417                                                    &c->sid[0]);
2418                         if (rc)
2419                                 goto out;
2420                 }
2421                 *out_sid = c->sid[0];
2422         } else
2423                 *out_sid = SECINITSID_UNLABELED;
2424
2425 out:
2426         read_unlock(&state->ss->policy_rwlock);
2427         return rc;
2428 }
2429
2430 /**
2431  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2432  * @dev_name: device name
2433  * @port: port number
2434  * @out_sid: security identifier
2435  */
2436 int security_ib_endport_sid(struct selinux_state *state,
2437                             const char *dev_name, u8 port_num, u32 *out_sid)
2438 {
2439         struct policydb *policydb;
2440         struct ocontext *c;
2441         int rc = 0;
2442
2443         read_lock(&state->ss->policy_rwlock);
2444
2445         policydb = &state->ss->policydb;
2446
2447         c = policydb->ocontexts[OCON_IBENDPORT];
2448         while (c) {
2449                 if (c->u.ibendport.port == port_num &&
2450                     !strncmp(c->u.ibendport.dev_name,
2451                              dev_name,
2452                              IB_DEVICE_NAME_MAX))
2453                         break;
2454
2455                 c = c->next;
2456         }
2457
2458         if (c) {
2459                 if (!c->sid[0]) {
2460                         rc = context_struct_to_sid(state, &c->context[0],
2461                                                    &c->sid[0]);
2462                         if (rc)
2463                                 goto out;
2464                 }
2465                 *out_sid = c->sid[0];
2466         } else
2467                 *out_sid = SECINITSID_UNLABELED;
2468
2469 out:
2470         read_unlock(&state->ss->policy_rwlock);
2471         return rc;
2472 }
2473
2474 /**
2475  * security_netif_sid - Obtain the SID for a network interface.
2476  * @name: interface name
2477  * @if_sid: interface SID
2478  */
2479 int security_netif_sid(struct selinux_state *state,
2480                        char *name, u32 *if_sid)
2481 {
2482         struct policydb *policydb;
2483         int rc = 0;
2484         struct ocontext *c;
2485
2486         read_lock(&state->ss->policy_rwlock);
2487
2488         policydb = &state->ss->policydb;
2489
2490         c = policydb->ocontexts[OCON_NETIF];
2491         while (c) {
2492                 if (strcmp(name, c->u.name) == 0)
2493                         break;
2494                 c = c->next;
2495         }
2496
2497         if (c) {
2498                 if (!c->sid[0] || !c->sid[1]) {
2499                         rc = context_struct_to_sid(state, &c->context[0],
2500                                                    &c->sid[0]);
2501                         if (rc)
2502                                 goto out;
2503                         rc = context_struct_to_sid(state, &c->context[1],
2504                                                    &c->sid[1]);
2505                         if (rc)
2506                                 goto out;
2507                 }
2508                 *if_sid = c->sid[0];
2509         } else
2510                 *if_sid = SECINITSID_NETIF;
2511
2512 out:
2513         read_unlock(&state->ss->policy_rwlock);
2514         return rc;
2515 }
2516
2517 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2518 {
2519         int i, fail = 0;
2520
2521         for (i = 0; i < 4; i++)
2522                 if (addr[i] != (input[i] & mask[i])) {
2523                         fail = 1;
2524                         break;
2525                 }
2526
2527         return !fail;
2528 }
2529
2530 /**
2531  * security_node_sid - Obtain the SID for a node (host).
2532  * @domain: communication domain aka address family
2533  * @addrp: address
2534  * @addrlen: address length in bytes
2535  * @out_sid: security identifier
2536  */
2537 int security_node_sid(struct selinux_state *state,
2538                       u16 domain,
2539                       void *addrp,
2540                       u32 addrlen,
2541                       u32 *out_sid)
2542 {
2543         struct policydb *policydb;
2544         int rc;
2545         struct ocontext *c;
2546
2547         read_lock(&state->ss->policy_rwlock);
2548
2549         policydb = &state->ss->policydb;
2550
2551         switch (domain) {
2552         case AF_INET: {
2553                 u32 addr;
2554
2555                 rc = -EINVAL;
2556                 if (addrlen != sizeof(u32))
2557                         goto out;
2558
2559                 addr = *((u32 *)addrp);
2560
2561                 c = policydb->ocontexts[OCON_NODE];
2562                 while (c) {
2563                         if (c->u.node.addr == (addr & c->u.node.mask))
2564                                 break;
2565                         c = c->next;
2566                 }
2567                 break;
2568         }
2569
2570         case AF_INET6:
2571                 rc = -EINVAL;
2572                 if (addrlen != sizeof(u64) * 2)
2573                         goto out;
2574                 c = policydb->ocontexts[OCON_NODE6];
2575                 while (c) {
2576                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2577                                                 c->u.node6.mask))
2578                                 break;
2579                         c = c->next;
2580                 }
2581                 break;
2582
2583         default:
2584                 rc = 0;
2585                 *out_sid = SECINITSID_NODE;
2586                 goto out;
2587         }
2588
2589         if (c) {
2590                 if (!c->sid[0]) {
2591                         rc = context_struct_to_sid(state,
2592                                                    &c->context[0],
2593                                                    &c->sid[0]);
2594                         if (rc)
2595                                 goto out;
2596                 }
2597                 *out_sid = c->sid[0];
2598         } else {
2599                 *out_sid = SECINITSID_NODE;
2600         }
2601
2602         rc = 0;
2603 out:
2604         read_unlock(&state->ss->policy_rwlock);
2605         return rc;
2606 }
2607
2608 #define SIDS_NEL 25
2609
2610 /**
2611  * security_get_user_sids - Obtain reachable SIDs for a user.
2612  * @fromsid: starting SID
2613  * @username: username
2614  * @sids: array of reachable SIDs for user
2615  * @nel: number of elements in @sids
2616  *
2617  * Generate the set of SIDs for legal security contexts
2618  * for a given user that can be reached by @fromsid.
2619  * Set *@sids to point to a dynamically allocated
2620  * array containing the set of SIDs.  Set *@nel to the
2621  * number of elements in the array.
2622  */
2623
2624 int security_get_user_sids(struct selinux_state *state,
2625                            u32 fromsid,
2626                            char *username,
2627                            u32 **sids,
2628                            u32 *nel)
2629 {
2630         struct policydb *policydb;
2631         struct sidtab *sidtab;
2632         struct context *fromcon, usercon;
2633         u32 *mysids = NULL, *mysids2, sid;
2634         u32 mynel = 0, maxnel = SIDS_NEL;
2635         struct user_datum *user;
2636         struct role_datum *role;
2637         struct ebitmap_node *rnode, *tnode;
2638         int rc = 0, i, j;
2639
2640         *sids = NULL;
2641         *nel = 0;
2642
2643         if (!selinux_initialized(state))
2644                 goto out;
2645
2646         read_lock(&state->ss->policy_rwlock);
2647
2648         policydb = &state->ss->policydb;
2649         sidtab = state->ss->sidtab;
2650
2651         context_init(&usercon);
2652
2653         rc = -EINVAL;
2654         fromcon = sidtab_search(sidtab, fromsid);
2655         if (!fromcon)
2656                 goto out_unlock;
2657
2658         rc = -EINVAL;
2659         user = hashtab_search(policydb->p_users.table, username);
2660         if (!user)
2661                 goto out_unlock;
2662
2663         usercon.user = user->value;
2664
2665         rc = -ENOMEM;
2666         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2667         if (!mysids)
2668                 goto out_unlock;
2669
2670         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2671                 role = policydb->role_val_to_struct[i];
2672                 usercon.role = i + 1;
2673                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2674                         usercon.type = j + 1;
2675                         /*
2676                          * The same context struct is reused here so the hash
2677                          * must be reset.
2678                          */
2679                         usercon.hash = 0;
2680
2681                         if (mls_setup_user_range(policydb, fromcon, user,
2682                                                  &usercon))
2683                                 continue;
2684
2685                         rc = context_struct_to_sid(state, &usercon, &sid);
2686                         if (rc)
2687                                 goto out_unlock;
2688                         if (mynel < maxnel) {
2689                                 mysids[mynel++] = sid;
2690                         } else {
2691                                 rc = -ENOMEM;
2692                                 maxnel += SIDS_NEL;
2693                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2694                                 if (!mysids2)
2695                                         goto out_unlock;
2696                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2697                                 kfree(mysids);
2698                                 mysids = mysids2;
2699                                 mysids[mynel++] = sid;
2700                         }
2701                 }
2702         }
2703         rc = 0;
2704 out_unlock:
2705         read_unlock(&state->ss->policy_rwlock);
2706         if (rc || !mynel) {
2707                 kfree(mysids);
2708                 goto out;
2709         }
2710
2711         rc = -ENOMEM;
2712         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2713         if (!mysids2) {
2714                 kfree(mysids);
2715                 goto out;
2716         }
2717         for (i = 0, j = 0; i < mynel; i++) {
2718                 struct av_decision dummy_avd;
2719                 rc = avc_has_perm_noaudit(state,
2720                                           fromsid, mysids[i],
2721                                           SECCLASS_PROCESS, /* kernel value */
2722                                           PROCESS__TRANSITION, AVC_STRICT,
2723                                           &dummy_avd);
2724                 if (!rc)
2725                         mysids2[j++] = mysids[i];
2726                 cond_resched();
2727         }
2728         rc = 0;
2729         kfree(mysids);
2730         *sids = mysids2;
2731         *nel = j;
2732 out:
2733         return rc;
2734 }
2735
2736 /**
2737  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2738  * @fstype: filesystem type
2739  * @path: path from root of mount
2740  * @sclass: file security class
2741  * @sid: SID for path
2742  *
2743  * Obtain a SID to use for a file in a filesystem that
2744  * cannot support xattr or use a fixed labeling behavior like
2745  * transition SIDs or task SIDs.
2746  *
2747  * The caller must acquire the policy_rwlock before calling this function.
2748  */
2749 static inline int __security_genfs_sid(struct selinux_state *state,
2750                                        const char *fstype,
2751                                        char *path,
2752                                        u16 orig_sclass,
2753                                        u32 *sid)
2754 {
2755         struct policydb *policydb = &state->ss->policydb;
2756         int len;
2757         u16 sclass;
2758         struct genfs *genfs;
2759         struct ocontext *c;
2760         int rc, cmp = 0;
2761
2762         while (path[0] == '/' && path[1] == '/')
2763                 path++;
2764
2765         sclass = unmap_class(&state->ss->map, orig_sclass);
2766         *sid = SECINITSID_UNLABELED;
2767
2768         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2769                 cmp = strcmp(fstype, genfs->fstype);
2770                 if (cmp <= 0)
2771                         break;
2772         }
2773
2774         rc = -ENOENT;
2775         if (!genfs || cmp)
2776                 goto out;
2777
2778         for (c = genfs->head; c; c = c->next) {
2779                 len = strlen(c->u.name);
2780                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2781                     (strncmp(c->u.name, path, len) == 0))
2782                         break;
2783         }
2784
2785         rc = -ENOENT;
2786         if (!c)
2787                 goto out;
2788
2789         if (!c->sid[0]) {
2790                 rc = context_struct_to_sid(state, &c->context[0], &c->sid[0]);
2791                 if (rc)
2792                         goto out;
2793         }
2794
2795         *sid = c->sid[0];
2796         rc = 0;
2797 out:
2798         return rc;
2799 }
2800
2801 /**
2802  * security_genfs_sid - Obtain a SID for a file in a filesystem
2803  * @fstype: filesystem type
2804  * @path: path from root of mount
2805  * @sclass: file security class
2806  * @sid: SID for path
2807  *
2808  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2809  * it afterward.
2810  */
2811 int security_genfs_sid(struct selinux_state *state,
2812                        const char *fstype,
2813                        char *path,
2814                        u16 orig_sclass,
2815                        u32 *sid)
2816 {
2817         int retval;
2818
2819         read_lock(&state->ss->policy_rwlock);
2820         retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid);
2821         read_unlock(&state->ss->policy_rwlock);
2822         return retval;
2823 }
2824
2825 /**
2826  * security_fs_use - Determine how to handle labeling for a filesystem.
2827  * @sb: superblock in question
2828  */
2829 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2830 {
2831         struct policydb *policydb;
2832         int rc = 0;
2833         struct ocontext *c;
2834         struct superblock_security_struct *sbsec = sb->s_security;
2835         const char *fstype = sb->s_type->name;
2836
2837         read_lock(&state->ss->policy_rwlock);
2838
2839         policydb = &state->ss->policydb;
2840
2841         c = policydb->ocontexts[OCON_FSUSE];
2842         while (c) {
2843                 if (strcmp(fstype, c->u.name) == 0)
2844                         break;
2845                 c = c->next;
2846         }
2847
2848         if (c) {
2849                 sbsec->behavior = c->v.behavior;
2850                 if (!c->sid[0]) {
2851                         rc = context_struct_to_sid(state, &c->context[0],
2852                                                    &c->sid[0]);
2853                         if (rc)
2854                                 goto out;
2855                 }
2856                 sbsec->sid = c->sid[0];
2857         } else {
2858                 rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR,
2859                                           &sbsec->sid);
2860                 if (rc) {
2861                         sbsec->behavior = SECURITY_FS_USE_NONE;
2862                         rc = 0;
2863                 } else {
2864                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2865                 }
2866         }
2867
2868 out:
2869         read_unlock(&state->ss->policy_rwlock);
2870         return rc;
2871 }
2872
2873 int security_get_bools(struct selinux_state *state,
2874                        u32 *len, char ***names, int **values)
2875 {
2876         struct policydb *policydb;
2877         u32 i;
2878         int rc;
2879
2880         if (!selinux_initialized(state)) {
2881                 *len = 0;
2882                 *names = NULL;
2883                 *values = NULL;
2884                 return 0;
2885         }
2886
2887         read_lock(&state->ss->policy_rwlock);
2888
2889         policydb = &state->ss->policydb;
2890
2891         *names = NULL;
2892         *values = NULL;
2893
2894         rc = 0;
2895         *len = policydb->p_bools.nprim;
2896         if (!*len)
2897                 goto out;
2898
2899         rc = -ENOMEM;
2900         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2901         if (!*names)
2902                 goto err;
2903
2904         rc = -ENOMEM;
2905         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2906         if (!*values)
2907                 goto err;
2908
2909         for (i = 0; i < *len; i++) {
2910                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
2911
2912                 rc = -ENOMEM;
2913                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
2914                                       GFP_ATOMIC);
2915                 if (!(*names)[i])
2916                         goto err;
2917         }
2918         rc = 0;
2919 out:
2920         read_unlock(&state->ss->policy_rwlock);
2921         return rc;
2922 err:
2923         if (*names) {
2924                 for (i = 0; i < *len; i++)
2925                         kfree((*names)[i]);
2926         }
2927         kfree(*values);
2928         goto out;
2929 }
2930
2931
2932 int security_set_bools(struct selinux_state *state, u32 len, int *values)
2933 {
2934         struct policydb *policydb;
2935         int rc;
2936         u32 i, lenp, seqno = 0;
2937
2938         write_lock_irq(&state->ss->policy_rwlock);
2939
2940         policydb = &state->ss->policydb;
2941
2942         rc = -EFAULT;
2943         lenp = policydb->p_bools.nprim;
2944         if (len != lenp)
2945                 goto out;
2946
2947         for (i = 0; i < len; i++) {
2948                 if (!!values[i] != policydb->bool_val_to_struct[i]->state) {
2949                         audit_log(audit_context(), GFP_ATOMIC,
2950                                 AUDIT_MAC_CONFIG_CHANGE,
2951                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2952                                 sym_name(policydb, SYM_BOOLS, i),
2953                                 !!values[i],
2954                                 policydb->bool_val_to_struct[i]->state,
2955                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2956                                 audit_get_sessionid(current));
2957                 }
2958                 if (values[i])
2959                         policydb->bool_val_to_struct[i]->state = 1;
2960                 else
2961                         policydb->bool_val_to_struct[i]->state = 0;
2962         }
2963
2964         evaluate_cond_nodes(policydb);
2965
2966         seqno = ++state->ss->latest_granting;
2967         rc = 0;
2968 out:
2969         write_unlock_irq(&state->ss->policy_rwlock);
2970         if (!rc) {
2971                 avc_ss_reset(state->avc, seqno);
2972                 selnl_notify_policyload(seqno);
2973                 selinux_status_update_policyload(state, seqno);
2974                 selinux_xfrm_notify_policyload();
2975         }
2976         return rc;
2977 }
2978
2979 int security_get_bool_value(struct selinux_state *state,
2980                             u32 index)
2981 {
2982         struct policydb *policydb;
2983         int rc;
2984         u32 len;
2985
2986         read_lock(&state->ss->policy_rwlock);
2987
2988         policydb = &state->ss->policydb;
2989
2990         rc = -EFAULT;
2991         len = policydb->p_bools.nprim;
2992         if (index >= len)
2993                 goto out;
2994
2995         rc = policydb->bool_val_to_struct[index]->state;
2996 out:
2997         read_unlock(&state->ss->policy_rwlock);
2998         return rc;
2999 }
3000
3001 static int security_preserve_bools(struct selinux_state *state,
3002                                    struct policydb *policydb)
3003 {
3004         int rc, *bvalues = NULL;
3005         char **bnames = NULL;
3006         struct cond_bool_datum *booldatum;
3007         u32 i, nbools = 0;
3008
3009         rc = security_get_bools(state, &nbools, &bnames, &bvalues);
3010         if (rc)
3011                 goto out;
3012         for (i = 0; i < nbools; i++) {
3013                 booldatum = hashtab_search(policydb->p_bools.table, bnames[i]);
3014                 if (booldatum)
3015                         booldatum->state = bvalues[i];
3016         }
3017         evaluate_cond_nodes(policydb);
3018
3019 out:
3020         if (bnames) {
3021                 for (i = 0; i < nbools; i++)
3022                         kfree(bnames[i]);
3023         }
3024         kfree(bnames);
3025         kfree(bvalues);
3026         return rc;
3027 }
3028
3029 /*
3030  * security_sid_mls_copy() - computes a new sid based on the given
3031  * sid and the mls portion of mls_sid.
3032  */
3033 int security_sid_mls_copy(struct selinux_state *state,
3034                           u32 sid, u32 mls_sid, u32 *new_sid)
3035 {
3036         struct policydb *policydb = &state->ss->policydb;
3037         struct sidtab *sidtab = state->ss->sidtab;
3038         struct context *context1;
3039         struct context *context2;
3040         struct context newcon;
3041         char *s;
3042         u32 len;
3043         int rc;
3044
3045         rc = 0;
3046         if (!selinux_initialized(state) || !policydb->mls_enabled) {
3047                 *new_sid = sid;
3048                 goto out;
3049         }
3050
3051         context_init(&newcon);
3052
3053         read_lock(&state->ss->policy_rwlock);
3054
3055         rc = -EINVAL;
3056         context1 = sidtab_search(sidtab, sid);
3057         if (!context1) {
3058                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3059                         __func__, sid);
3060                 goto out_unlock;
3061         }
3062
3063         rc = -EINVAL;
3064         context2 = sidtab_search(sidtab, mls_sid);
3065         if (!context2) {
3066                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3067                         __func__, mls_sid);
3068                 goto out_unlock;
3069         }
3070
3071         newcon.user = context1->user;
3072         newcon.role = context1->role;
3073         newcon.type = context1->type;
3074         rc = mls_context_cpy(&newcon, context2);
3075         if (rc)
3076                 goto out_unlock;
3077
3078         /* Check the validity of the new context. */
3079         if (!policydb_context_isvalid(policydb, &newcon)) {
3080                 rc = convert_context_handle_invalid_context(state, &newcon);
3081                 if (rc) {
3082                         if (!context_struct_to_string(policydb, &newcon, &s,
3083                                                       &len)) {
3084                                 struct audit_buffer *ab;
3085
3086                                 ab = audit_log_start(audit_context(),
3087                                                      GFP_ATOMIC,
3088                                                      AUDIT_SELINUX_ERR);
3089                                 audit_log_format(ab,
3090                                                  "op=security_sid_mls_copy invalid_context=");
3091                                 /* don't record NUL with untrusted strings */
3092                                 audit_log_n_untrustedstring(ab, s, len - 1);
3093                                 audit_log_end(ab);
3094                                 kfree(s);
3095                         }
3096                         goto out_unlock;
3097                 }
3098         }
3099         rc = context_struct_to_sid(state, &newcon, new_sid);
3100 out_unlock:
3101         read_unlock(&state->ss->policy_rwlock);
3102         context_destroy(&newcon);
3103 out:
3104         return rc;
3105 }
3106
3107 /**
3108  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3109  * @nlbl_sid: NetLabel SID
3110  * @nlbl_type: NetLabel labeling protocol type
3111  * @xfrm_sid: XFRM SID
3112  *
3113  * Description:
3114  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3115  * resolved into a single SID it is returned via @peer_sid and the function
3116  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3117  * returns a negative value.  A table summarizing the behavior is below:
3118  *
3119  *                                 | function return |      @sid
3120  *   ------------------------------+-----------------+-----------------
3121  *   no peer labels                |        0        |    SECSID_NULL
3122  *   single peer label             |        0        |    <peer_label>
3123  *   multiple, consistent labels   |        0        |    <peer_label>
3124  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3125  *
3126  */
3127 int security_net_peersid_resolve(struct selinux_state *state,
3128                                  u32 nlbl_sid, u32 nlbl_type,
3129                                  u32 xfrm_sid,
3130                                  u32 *peer_sid)
3131 {
3132         struct policydb *policydb = &state->ss->policydb;
3133         struct sidtab *sidtab = state->ss->sidtab;
3134         int rc;
3135         struct context *nlbl_ctx;
3136         struct context *xfrm_ctx;
3137
3138         *peer_sid = SECSID_NULL;
3139
3140         /* handle the common (which also happens to be the set of easy) cases
3141          * right away, these two if statements catch everything involving a
3142          * single or absent peer SID/label */
3143         if (xfrm_sid == SECSID_NULL) {
3144                 *peer_sid = nlbl_sid;
3145                 return 0;
3146         }
3147         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3148          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3149          * is present */
3150         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3151                 *peer_sid = xfrm_sid;
3152                 return 0;
3153         }
3154
3155         /*
3156          * We don't need to check initialized here since the only way both
3157          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3158          * security server was initialized and state->initialized was true.
3159          */
3160         if (!policydb->mls_enabled)
3161                 return 0;
3162
3163         read_lock(&state->ss->policy_rwlock);
3164
3165         rc = -EINVAL;
3166         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3167         if (!nlbl_ctx) {
3168                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3169                        __func__, nlbl_sid);
3170                 goto out;
3171         }
3172         rc = -EINVAL;
3173         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3174         if (!xfrm_ctx) {
3175                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3176                        __func__, xfrm_sid);
3177                 goto out;
3178         }
3179         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3180         if (rc)
3181                 goto out;
3182
3183         /* at present NetLabel SIDs/labels really only carry MLS
3184          * information so if the MLS portion of the NetLabel SID
3185          * matches the MLS portion of the labeled XFRM SID/label
3186          * then pass along the XFRM SID as it is the most
3187          * expressive */
3188         *peer_sid = xfrm_sid;
3189 out:
3190         read_unlock(&state->ss->policy_rwlock);
3191         return rc;
3192 }
3193
3194 static int get_classes_callback(void *k, void *d, void *args)
3195 {
3196         struct class_datum *datum = d;
3197         char *name = k, **classes = args;
3198         int value = datum->value - 1;
3199
3200         classes[value] = kstrdup(name, GFP_ATOMIC);
3201         if (!classes[value])
3202                 return -ENOMEM;
3203
3204         return 0;
3205 }
3206
3207 int security_get_classes(struct selinux_state *state,
3208                          char ***classes, int *nclasses)
3209 {
3210         struct policydb *policydb = &state->ss->policydb;
3211         int rc;
3212
3213         if (!selinux_initialized(state)) {
3214                 *nclasses = 0;
3215                 *classes = NULL;
3216                 return 0;
3217         }
3218
3219         read_lock(&state->ss->policy_rwlock);
3220
3221         rc = -ENOMEM;
3222         *nclasses = policydb->p_classes.nprim;
3223         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3224         if (!*classes)
3225                 goto out;
3226
3227         rc = hashtab_map(policydb->p_classes.table, get_classes_callback,
3228                         *classes);
3229         if (rc) {
3230                 int i;
3231                 for (i = 0; i < *nclasses; i++)
3232                         kfree((*classes)[i]);
3233                 kfree(*classes);
3234         }
3235
3236 out:
3237         read_unlock(&state->ss->policy_rwlock);
3238         return rc;
3239 }
3240
3241 static int get_permissions_callback(void *k, void *d, void *args)
3242 {
3243         struct perm_datum *datum = d;
3244         char *name = k, **perms = args;
3245         int value = datum->value - 1;
3246
3247         perms[value] = kstrdup(name, GFP_ATOMIC);
3248         if (!perms[value])
3249                 return -ENOMEM;
3250
3251         return 0;
3252 }
3253
3254 int security_get_permissions(struct selinux_state *state,
3255                              char *class, char ***perms, int *nperms)
3256 {
3257         struct policydb *policydb = &state->ss->policydb;
3258         int rc, i;
3259         struct class_datum *match;
3260
3261         read_lock(&state->ss->policy_rwlock);
3262
3263         rc = -EINVAL;
3264         match = hashtab_search(policydb->p_classes.table, class);
3265         if (!match) {
3266                 pr_err("SELinux: %s:  unrecognized class %s\n",
3267                         __func__, class);
3268                 goto out;
3269         }
3270
3271         rc = -ENOMEM;
3272         *nperms = match->permissions.nprim;
3273         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3274         if (!*perms)
3275                 goto out;
3276
3277         if (match->comdatum) {
3278                 rc = hashtab_map(match->comdatum->permissions.table,
3279                                 get_permissions_callback, *perms);
3280                 if (rc)
3281                         goto err;
3282         }
3283
3284         rc = hashtab_map(match->permissions.table, get_permissions_callback,
3285                         *perms);
3286         if (rc)
3287                 goto err;
3288
3289 out:
3290         read_unlock(&state->ss->policy_rwlock);
3291         return rc;
3292
3293 err:
3294         read_unlock(&state->ss->policy_rwlock);
3295         for (i = 0; i < *nperms; i++)
3296                 kfree((*perms)[i]);
3297         kfree(*perms);
3298         return rc;
3299 }
3300
3301 int security_get_reject_unknown(struct selinux_state *state)
3302 {
3303         return state->ss->policydb.reject_unknown;
3304 }
3305
3306 int security_get_allow_unknown(struct selinux_state *state)
3307 {
3308         return state->ss->policydb.allow_unknown;
3309 }
3310
3311 /**
3312  * security_policycap_supported - Check for a specific policy capability
3313  * @req_cap: capability
3314  *
3315  * Description:
3316  * This function queries the currently loaded policy to see if it supports the
3317  * capability specified by @req_cap.  Returns true (1) if the capability is
3318  * supported, false (0) if it isn't supported.
3319  *
3320  */
3321 int security_policycap_supported(struct selinux_state *state,
3322                                  unsigned int req_cap)
3323 {
3324         struct policydb *policydb = &state->ss->policydb;
3325         int rc;
3326
3327         read_lock(&state->ss->policy_rwlock);
3328         rc = ebitmap_get_bit(&policydb->policycaps, req_cap);
3329         read_unlock(&state->ss->policy_rwlock);
3330
3331         return rc;
3332 }
3333
3334 struct selinux_audit_rule {
3335         u32 au_seqno;
3336         struct context au_ctxt;
3337 };
3338
3339 void selinux_audit_rule_free(void *vrule)
3340 {
3341         struct selinux_audit_rule *rule = vrule;
3342
3343         if (rule) {
3344                 context_destroy(&rule->au_ctxt);
3345                 kfree(rule);
3346         }
3347 }
3348
3349 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3350 {
3351         struct selinux_state *state = &selinux_state;
3352         struct policydb *policydb = &state->ss->policydb;
3353         struct selinux_audit_rule *tmprule;
3354         struct role_datum *roledatum;
3355         struct type_datum *typedatum;
3356         struct user_datum *userdatum;
3357         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3358         int rc = 0;
3359
3360         *rule = NULL;
3361
3362         if (!selinux_initialized(state))
3363                 return -EOPNOTSUPP;
3364
3365         switch (field) {
3366         case AUDIT_SUBJ_USER:
3367         case AUDIT_SUBJ_ROLE:
3368         case AUDIT_SUBJ_TYPE:
3369         case AUDIT_OBJ_USER:
3370         case AUDIT_OBJ_ROLE:
3371         case AUDIT_OBJ_TYPE:
3372                 /* only 'equals' and 'not equals' fit user, role, and type */
3373                 if (op != Audit_equal && op != Audit_not_equal)
3374                         return -EINVAL;
3375                 break;
3376         case AUDIT_SUBJ_SEN:
3377         case AUDIT_SUBJ_CLR:
3378         case AUDIT_OBJ_LEV_LOW:
3379         case AUDIT_OBJ_LEV_HIGH:
3380                 /* we do not allow a range, indicated by the presence of '-' */
3381                 if (strchr(rulestr, '-'))
3382                         return -EINVAL;
3383                 break;
3384         default:
3385                 /* only the above fields are valid */
3386                 return -EINVAL;
3387         }
3388
3389         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3390         if (!tmprule)
3391                 return -ENOMEM;
3392
3393         context_init(&tmprule->au_ctxt);
3394
3395         read_lock(&state->ss->policy_rwlock);
3396
3397         tmprule->au_seqno = state->ss->latest_granting;
3398
3399         switch (field) {
3400         case AUDIT_SUBJ_USER:
3401         case AUDIT_OBJ_USER:
3402                 rc = -EINVAL;
3403                 userdatum = hashtab_search(policydb->p_users.table, rulestr);
3404                 if (!userdatum)
3405                         goto out;
3406                 tmprule->au_ctxt.user = userdatum->value;
3407                 break;
3408         case AUDIT_SUBJ_ROLE:
3409         case AUDIT_OBJ_ROLE:
3410                 rc = -EINVAL;
3411                 roledatum = hashtab_search(policydb->p_roles.table, rulestr);
3412                 if (!roledatum)
3413                         goto out;
3414                 tmprule->au_ctxt.role = roledatum->value;
3415                 break;
3416         case AUDIT_SUBJ_TYPE:
3417         case AUDIT_OBJ_TYPE:
3418                 rc = -EINVAL;
3419                 typedatum = hashtab_search(policydb->p_types.table, rulestr);
3420                 if (!typedatum)
3421                         goto out;
3422                 tmprule->au_ctxt.type = typedatum->value;
3423                 break;
3424         case AUDIT_SUBJ_SEN:
3425         case AUDIT_SUBJ_CLR:
3426         case AUDIT_OBJ_LEV_LOW:
3427         case AUDIT_OBJ_LEV_HIGH:
3428                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3429                                      GFP_ATOMIC);
3430                 if (rc)
3431                         goto out;
3432                 break;
3433         }
3434         rc = 0;
3435 out:
3436         read_unlock(&state->ss->policy_rwlock);
3437
3438         if (rc) {
3439                 selinux_audit_rule_free(tmprule);
3440                 tmprule = NULL;
3441         }
3442
3443         *rule = tmprule;
3444
3445         return rc;
3446 }
3447
3448 /* Check to see if the rule contains any selinux fields */
3449 int selinux_audit_rule_known(struct audit_krule *rule)
3450 {
3451         int i;
3452
3453         for (i = 0; i < rule->field_count; i++) {
3454                 struct audit_field *f = &rule->fields[i];
3455                 switch (f->type) {
3456                 case AUDIT_SUBJ_USER:
3457                 case AUDIT_SUBJ_ROLE:
3458                 case AUDIT_SUBJ_TYPE:
3459                 case AUDIT_SUBJ_SEN:
3460                 case AUDIT_SUBJ_CLR:
3461                 case AUDIT_OBJ_USER:
3462                 case AUDIT_OBJ_ROLE:
3463                 case AUDIT_OBJ_TYPE:
3464                 case AUDIT_OBJ_LEV_LOW:
3465                 case AUDIT_OBJ_LEV_HIGH:
3466                         return 1;
3467                 }
3468         }
3469
3470         return 0;
3471 }
3472
3473 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3474 {
3475         struct selinux_state *state = &selinux_state;
3476         struct context *ctxt;
3477         struct mls_level *level;
3478         struct selinux_audit_rule *rule = vrule;
3479         int match = 0;
3480
3481         if (unlikely(!rule)) {
3482                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3483                 return -ENOENT;
3484         }
3485
3486         read_lock(&state->ss->policy_rwlock);
3487
3488         if (rule->au_seqno < state->ss->latest_granting) {
3489                 match = -ESTALE;
3490                 goto out;
3491         }
3492
3493         ctxt = sidtab_search(state->ss->sidtab, sid);
3494         if (unlikely(!ctxt)) {
3495                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3496                           sid);
3497                 match = -ENOENT;
3498                 goto out;
3499         }
3500
3501         /* a field/op pair that is not caught here will simply fall through
3502            without a match */
3503         switch (field) {
3504         case AUDIT_SUBJ_USER:
3505         case AUDIT_OBJ_USER:
3506                 switch (op) {
3507                 case Audit_equal:
3508                         match = (ctxt->user == rule->au_ctxt.user);
3509                         break;
3510                 case Audit_not_equal:
3511                         match = (ctxt->user != rule->au_ctxt.user);
3512                         break;
3513                 }
3514                 break;
3515         case AUDIT_SUBJ_ROLE:
3516         case AUDIT_OBJ_ROLE:
3517                 switch (op) {
3518                 case Audit_equal:
3519                         match = (ctxt->role == rule->au_ctxt.role);
3520                         break;
3521                 case Audit_not_equal:
3522                         match = (ctxt->role != rule->au_ctxt.role);
3523                         break;
3524                 }
3525                 break;
3526         case AUDIT_SUBJ_TYPE:
3527         case AUDIT_OBJ_TYPE:
3528                 switch (op) {
3529                 case Audit_equal:
3530                         match = (ctxt->type == rule->au_ctxt.type);
3531                         break;
3532                 case Audit_not_equal:
3533                         match = (ctxt->type != rule->au_ctxt.type);
3534                         break;
3535                 }
3536                 break;
3537         case AUDIT_SUBJ_SEN:
3538         case AUDIT_SUBJ_CLR:
3539         case AUDIT_OBJ_LEV_LOW:
3540         case AUDIT_OBJ_LEV_HIGH:
3541                 level = ((field == AUDIT_SUBJ_SEN ||
3542                           field == AUDIT_OBJ_LEV_LOW) ?
3543                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3544                 switch (op) {
3545                 case Audit_equal:
3546                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3547                                              level);
3548                         break;
3549                 case Audit_not_equal:
3550                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3551                                               level);
3552                         break;
3553                 case Audit_lt:
3554                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3555                                                level) &&
3556                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3557                                                level));
3558                         break;
3559                 case Audit_le:
3560                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3561                                               level);
3562                         break;
3563                 case Audit_gt:
3564                         match = (mls_level_dom(level,
3565                                               &rule->au_ctxt.range.level[0]) &&
3566                                  !mls_level_eq(level,
3567                                                &rule->au_ctxt.range.level[0]));
3568                         break;
3569                 case Audit_ge:
3570                         match = mls_level_dom(level,
3571                                               &rule->au_ctxt.range.level[0]);
3572                         break;
3573                 }
3574         }
3575
3576 out:
3577         read_unlock(&state->ss->policy_rwlock);
3578         return match;
3579 }
3580
3581 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3582
3583 static int aurule_avc_callback(u32 event)
3584 {
3585         int err = 0;
3586
3587         if (event == AVC_CALLBACK_RESET && aurule_callback)
3588                 err = aurule_callback();
3589         return err;
3590 }
3591
3592 static int __init aurule_init(void)
3593 {
3594         int err;
3595
3596         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3597         if (err)
3598                 panic("avc_add_callback() failed, error %d\n", err);
3599
3600         return err;
3601 }
3602 __initcall(aurule_init);
3603
3604 #ifdef CONFIG_NETLABEL
3605 /**
3606  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3607  * @secattr: the NetLabel packet security attributes
3608  * @sid: the SELinux SID
3609  *
3610  * Description:
3611  * Attempt to cache the context in @ctx, which was derived from the packet in
3612  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3613  * already been initialized.
3614  *
3615  */
3616 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3617                                       u32 sid)
3618 {
3619         u32 *sid_cache;
3620
3621         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3622         if (sid_cache == NULL)
3623                 return;
3624         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3625         if (secattr->cache == NULL) {
3626                 kfree(sid_cache);
3627                 return;
3628         }
3629
3630         *sid_cache = sid;
3631         secattr->cache->free = kfree;
3632         secattr->cache->data = sid_cache;
3633         secattr->flags |= NETLBL_SECATTR_CACHE;
3634 }
3635
3636 /**
3637  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3638  * @secattr: the NetLabel packet security attributes
3639  * @sid: the SELinux SID
3640  *
3641  * Description:
3642  * Convert the given NetLabel security attributes in @secattr into a
3643  * SELinux SID.  If the @secattr field does not contain a full SELinux
3644  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3645  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3646  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3647  * conversion for future lookups.  Returns zero on success, negative values on
3648  * failure.
3649  *
3650  */
3651 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3652                                    struct netlbl_lsm_secattr *secattr,
3653                                    u32 *sid)
3654 {
3655         struct policydb *policydb = &state->ss->policydb;
3656         struct sidtab *sidtab = state->ss->sidtab;
3657         int rc;
3658         struct context *ctx;
3659         struct context ctx_new;
3660
3661         if (!selinux_initialized(state)) {
3662                 *sid = SECSID_NULL;
3663                 return 0;
3664         }
3665
3666         read_lock(&state->ss->policy_rwlock);
3667
3668         if (secattr->flags & NETLBL_SECATTR_CACHE)
3669                 *sid = *(u32 *)secattr->cache->data;
3670         else if (secattr->flags & NETLBL_SECATTR_SECID)
3671                 *sid = secattr->attr.secid;
3672         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3673                 rc = -EIDRM;
3674                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3675                 if (ctx == NULL)
3676                         goto out;
3677
3678                 context_init(&ctx_new);
3679                 ctx_new.user = ctx->user;
3680                 ctx_new.role = ctx->role;
3681                 ctx_new.type = ctx->type;
3682                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3683                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3684                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3685                         if (rc)
3686                                 goto out;
3687                 }
3688                 rc = -EIDRM;
3689                 if (!mls_context_isvalid(policydb, &ctx_new))
3690                         goto out_free;
3691
3692                 rc = context_struct_to_sid(state, &ctx_new, sid);
3693                 if (rc)
3694                         goto out_free;
3695
3696                 security_netlbl_cache_add(secattr, *sid);
3697
3698                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3699         } else
3700                 *sid = SECSID_NULL;
3701
3702         read_unlock(&state->ss->policy_rwlock);
3703         return 0;
3704 out_free:
3705         ebitmap_destroy(&ctx_new.range.level[0].cat);
3706 out:
3707         read_unlock(&state->ss->policy_rwlock);
3708         return rc;
3709 }
3710
3711 /**
3712  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3713  * @sid: the SELinux SID
3714  * @secattr: the NetLabel packet security attributes
3715  *
3716  * Description:
3717  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3718  * Returns zero on success, negative values on failure.
3719  *
3720  */
3721 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3722                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3723 {
3724         struct policydb *policydb = &state->ss->policydb;
3725         int rc;
3726         struct context *ctx;
3727
3728         if (!selinux_initialized(state))
3729                 return 0;
3730
3731         read_lock(&state->ss->policy_rwlock);
3732
3733         rc = -ENOENT;
3734         ctx = sidtab_search(state->ss->sidtab, sid);
3735         if (ctx == NULL)
3736                 goto out;
3737
3738         rc = -ENOMEM;
3739         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3740                                   GFP_ATOMIC);
3741         if (secattr->domain == NULL)
3742                 goto out;
3743
3744         secattr->attr.secid = sid;
3745         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3746         mls_export_netlbl_lvl(policydb, ctx, secattr);
3747         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3748 out:
3749         read_unlock(&state->ss->policy_rwlock);
3750         return rc;
3751 }
3752 #endif /* CONFIG_NETLABEL */
3753
3754 /**
3755  * security_read_policy - read the policy.
3756  * @data: binary policy data
3757  * @len: length of data in bytes
3758  *
3759  */
3760 int security_read_policy(struct selinux_state *state,
3761                          void **data, size_t *len)
3762 {
3763         struct policydb *policydb = &state->ss->policydb;
3764         int rc;
3765         struct policy_file fp;
3766
3767         if (!selinux_initialized(state))
3768                 return -EINVAL;
3769
3770         *len = security_policydb_len(state);
3771
3772         *data = vmalloc_user(*len);
3773         if (!*data)
3774                 return -ENOMEM;
3775
3776         fp.data = *data;
3777         fp.len = *len;
3778
3779         read_lock(&state->ss->policy_rwlock);
3780         rc = policydb_write(policydb, &fp);
3781         read_unlock(&state->ss->policy_rwlock);
3782
3783         if (rc)
3784                 return rc;
3785
3786         *len = (unsigned long)fp.data - (unsigned long)*data;
3787         return 0;
3788
3789 }