security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   5  *           James Morris <jmorris@redhat.com>
   6  *
   7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8  *
   9  *      Support for enhanced MLS infrastructure.
  10  *      Support for context based audit filters.
  11  *
  12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  13  *
  14  *      Added conditional policy language extensions
  15  *
  16  * Updated: Hewlett-Packard <paul.moore@hp.com>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <csellers@tresys.com>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  26  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  27  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  28  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  29  *      This program is free software; you can redistribute it and/or modify
  30  *      it under the terms of the GNU General Public License as published by
  31  *      the Free Software Foundation, version 2.
  32  */
  33 #include <linux/kernel.h>
  34 #include <linux/slab.h>
  35 #include <linux/string.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/rcupdate.h>
  38 #include <linux/errno.h>
  39 #include <linux/in.h>
  40 #include <linux/sched.h>
  41 #include <linux/audit.h>
  42 #include <linux/mutex.h>
  43 #include <linux/selinux.h>
  44 #include <net/netlabel.h>
  45
  46 #include "flask.h"
  47 #include "avc.h"
  48 #include "avc_ss.h"
  49 #include "security.h"
  50 #include "context.h"
  51 #include "policydb.h"
  52 #include "sidtab.h"
  53 #include "services.h"
  54 #include "conditional.h"
  55 #include "mls.h"
  56 #include "objsec.h"
  57 #include "netlabel.h"
  58 #include "xfrm.h"
  59 #include "ebitmap.h"
  60 #include "audit.h"
  61
  62 extern void selnl_notify_policyload(u32 seqno);
  63 unsigned int policydb_loaded_version;
  64
  65 int selinux_policycap_netpeer;
  66 int selinux_policycap_openperm;
  67
  68 /*
  69  * This is declared in avc.c
  70  */
  71 extern const struct selinux_class_perm selinux_class_perm;
  72
  73 static DEFINE_RWLOCK(policy_rwlock);
  74
  75 static struct sidtab sidtab;
  76 struct policydb policydb;
  77 int ss_initialized;
  78
  79 /*
  80  * The largest sequence number that has been used when
  81  * providing an access decision to the access vector cache.
  82  * The sequence number only changes when a policy change
  83  * occurs.
  84  */
  85 static u32 latest_granting;
  86
  87 /* Forward declaration. */
  88 static int context_struct_to_string(struct context *context, char **scontext,
  89                                     u32 *scontext_len);
  90
  91 static int context_struct_compute_av(struct context *scontext,
  92                                      struct context *tcontext,
  93                                      u16 tclass,
  94                                      u32 requested,
  95                                      struct av_decision *avd);
  96 /*
  97  * Return the boolean value of a constraint expression
  98  * when it is applied to the specified source and target
  99  * security contexts.
 100  *
 101  * xcontext is a special beast...  It is used by the validatetrans rules
 102  * only.  For these rules, scontext is the context before the transition,
 103  * tcontext is the context after the transition, and xcontext is the context
 104  * of the process performing the transition.  All other callers of
 105  * constraint_expr_eval should pass in NULL for xcontext.
 106  */
 107 static int constraint_expr_eval(struct context *scontext,
 108                                 struct context *tcontext,
 109                                 struct context *xcontext,
 110                                 struct constraint_expr *cexpr)
 111 {
 112         u32 val1, val2;
 113         struct context *c;
 114         struct role_datum *r1, *r2;
 115         struct mls_level *l1, *l2;
 116         struct constraint_expr *e;
 117         int s[CEXPR_MAXDEPTH];
 118         int sp = -1;
 119
 120         for (e = cexpr; e; e = e->next) {
 121                 switch (e->expr_type) {
 122                 case CEXPR_NOT:
 123                         BUG_ON(sp < 0);
 124                         s[sp] = !s[sp];
 125                         break;
 126                 case CEXPR_AND:
 127                         BUG_ON(sp < 1);
 128                         sp--;
 129                         s[sp] &= s[sp+1];
 130                         break;
 131                 case CEXPR_OR:
 132                         BUG_ON(sp < 1);
 133                         sp--;
 134                         s[sp] |= s[sp+1];
 135                         break;
 136                 case CEXPR_ATTR:
 137                         if (sp == (CEXPR_MAXDEPTH-1))
 138                                 return 0;
 139                         switch (e->attr) {
 140                         case CEXPR_USER:
 141                                 val1 = scontext->user;
 142                                 val2 = tcontext->user;
 143                                 break;
 144                         case CEXPR_TYPE:
 145                                 val1 = scontext->type;
 146                                 val2 = tcontext->type;
 147                                 break;
 148                         case CEXPR_ROLE:
 149                                 val1 = scontext->role;
 150                                 val2 = tcontext->role;
 151                                 r1 = policydb.role_val_to_struct[val1 - 1];
 152                                 r2 = policydb.role_val_to_struct[val2 - 1];
 153                                 switch (e->op) {
 154                                 case CEXPR_DOM:
 155                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 156                                                                   val2 - 1);
 157                                         continue;
 158                                 case CEXPR_DOMBY:
 159                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 160                                                                   val1 - 1);
 161                                         continue;
 162                                 case CEXPR_INCOMP:
 163                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 164                                                                     val2 - 1) &&
 165                                                    !ebitmap_get_bit(&r2->dominates,
 166                                                                     val1 - 1));
 167                                         continue;
 168                                 default:
 169                                         break;
 170                                 }
 171                                 break;
 172                         case CEXPR_L1L2:
 173                                 l1 = &(scontext->range.level[0]);
 174                                 l2 = &(tcontext->range.level[0]);
 175                                 goto mls_ops;
 176                         case CEXPR_L1H2:
 177                                 l1 = &(scontext->range.level[0]);
 178                                 l2 = &(tcontext->range.level[1]);
 179                                 goto mls_ops;
 180                         case CEXPR_H1L2:
 181                                 l1 = &(scontext->range.level[1]);
 182                                 l2 = &(tcontext->range.level[0]);
 183                                 goto mls_ops;
 184                         case CEXPR_H1H2:
 185                                 l1 = &(scontext->range.level[1]);
 186                                 l2 = &(tcontext->range.level[1]);
 187                                 goto mls_ops;
 188                         case CEXPR_L1H1:
 189                                 l1 = &(scontext->range.level[0]);
 190                                 l2 = &(scontext->range.level[1]);
 191                                 goto mls_ops;
 192                         case CEXPR_L2H2:
 193                                 l1 = &(tcontext->range.level[0]);
 194                                 l2 = &(tcontext->range.level[1]);
 195                                 goto mls_ops;
 196 mls_ops:
 197                         switch (e->op) {
 198                         case CEXPR_EQ:
 199                                 s[++sp] = mls_level_eq(l1, l2);
 200                                 continue;
 201                         case CEXPR_NEQ:
 202                                 s[++sp] = !mls_level_eq(l1, l2);
 203                                 continue;
 204                         case CEXPR_DOM:
 205                                 s[++sp] = mls_level_dom(l1, l2);
 206                                 continue;
 207                         case CEXPR_DOMBY:
 208                                 s[++sp] = mls_level_dom(l2, l1);
 209                                 continue;
 210                         case CEXPR_INCOMP:
 211                                 s[++sp] = mls_level_incomp(l2, l1);
 212                                 continue;
 213                         default:
 214                                 BUG();
 215                                 return 0;
 216                         }
 217                         break;
 218                         default:
 219                                 BUG();
 220                                 return 0;
 221                         }
 222
 223                         switch (e->op) {
 224                         case CEXPR_EQ:
 225                                 s[++sp] = (val1 == val2);
 226                                 break;
 227                         case CEXPR_NEQ:
 228                                 s[++sp] = (val1 != val2);
 229                                 break;
 230                         default:
 231                                 BUG();
 232                                 return 0;
 233                         }
 234                         break;
 235                 case CEXPR_NAMES:
 236                         if (sp == (CEXPR_MAXDEPTH-1))
 237                                 return 0;
 238                         c = scontext;
 239                         if (e->attr & CEXPR_TARGET)
 240                                 c = tcontext;
 241                         else if (e->attr & CEXPR_XTARGET) {
 242                                 c = xcontext;
 243                                 if (!c) {
 244                                         BUG();
 245                                         return 0;
 246                                 }
 247                         }
 248                         if (e->attr & CEXPR_USER)
 249                                 val1 = c->user;
 250                         else if (e->attr & CEXPR_ROLE)
 251                                 val1 = c->role;
 252                         else if (e->attr & CEXPR_TYPE)
 253                                 val1 = c->type;
 254                         else {
 255                                 BUG();
 256                                 return 0;
 257                         }
 258
 259                         switch (e->op) {
 260                         case CEXPR_EQ:
 261                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 262                                 break;
 263                         case CEXPR_NEQ:
 264                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 265                                 break;
 266                         default:
 267                                 BUG();
 268                                 return 0;
 269                         }
 270                         break;
 271                 default:
 272                         BUG();
 273                         return 0;
 274                 }
 275         }
 276
 277         BUG_ON(sp != 0);
 278         return s[0];
 279 }
 280
 281 /*
 282  * security_boundary_permission - drops violated permissions
 283  * on boundary constraint.
 284  */
 285 static void type_attribute_bounds_av(struct context *scontext,
 286                                      struct context *tcontext,
 287                                      u16 tclass,
 288                                      u32 requested,
 289                                      struct av_decision *avd)
 290 {
 291         struct context lo_scontext;
 292         struct context lo_tcontext;
 293         struct av_decision lo_avd;
 294         struct type_datum *source
 295                 = policydb.type_val_to_struct[scontext->type - 1];
 296         struct type_datum *target
 297                 = policydb.type_val_to_struct[tcontext->type - 1];
 298         u32 masked = 0;
 299
 300         if (source->bounds) {
 301                 memset(&lo_avd, 0, sizeof(lo_avd));
 302
 303                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 304                 lo_scontext.type = source->bounds;
 305
 306                 context_struct_compute_av(&lo_scontext,
 307                                           tcontext,
 308                                           tclass,
 309                                           requested,
 310                                           &lo_avd);
 311                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 312                         return;         /* no masked permission */
 313                 masked = ~lo_avd.allowed & avd->allowed;
 314         }
 315
 316         if (target->bounds) {
 317                 memset(&lo_avd, 0, sizeof(lo_avd));
 318
 319                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 320                 lo_tcontext.type = target->bounds;
 321
 322                 context_struct_compute_av(scontext,
 323                                           &lo_tcontext,
 324                                           tclass,
 325                                           requested,
 326                                           &lo_avd);
 327                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 328                         return;         /* no masked permission */
 329                 masked = ~lo_avd.allowed & avd->allowed;
 330         }
 331
 332         if (source->bounds && target->bounds) {
 333                 memset(&lo_avd, 0, sizeof(lo_avd));
 334                 /*
 335                  * lo_scontext and lo_tcontext are already
 336                  * set up.
 337                  */
 338
 339                 context_struct_compute_av(&lo_scontext,
 340                                           &lo_tcontext,
 341                                           tclass,
 342                                           requested,
 343                                           &lo_avd);
 344                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 345                         return;         /* no masked permission */
 346                 masked = ~lo_avd.allowed & avd->allowed;
 347         }
 348
 349         if (masked) {
 350                 struct audit_buffer *ab;
 351                 char *stype_name
 352                         = policydb.p_type_val_to_name[source->value - 1];
 353                 char *ttype_name
 354                         = policydb.p_type_val_to_name[target->value - 1];
 355                 char *tclass_name
 356                         = policydb.p_class_val_to_name[tclass - 1];
 357
 358                 /* mask violated permissions */
 359                 avd->allowed &= ~masked;
 360
 361                 /* notice to userspace via audit message */
 362                 ab = audit_log_start(current->audit_context,
 363                                      GFP_ATOMIC, AUDIT_SELINUX_ERR);
 364                 if (!ab)
 365                         return;
 366
 367                 audit_log_format(ab, "av boundary violation: "
 368                                  "source=%s target=%s tclass=%s",
 369                                  stype_name, ttype_name, tclass_name);
 370                 avc_dump_av(ab, tclass, masked);
 371                 audit_log_end(ab);
 372         }
 373 }
 374
 375 /*
 376  * Compute access vectors based on a context structure pair for
 377  * the permissions in a particular class.
 378  */
 379 static int context_struct_compute_av(struct context *scontext,
 380                                      struct context *tcontext,
 381                                      u16 tclass,
 382                                      u32 requested,
 383                                      struct av_decision *avd)
 384 {
 385         struct constraint_node *constraint;
 386         struct role_allow *ra;
 387         struct avtab_key avkey;
 388         struct avtab_node *node;
 389         struct class_datum *tclass_datum;
 390         struct ebitmap *sattr, *tattr;
 391         struct ebitmap_node *snode, *tnode;
 392         const struct selinux_class_perm *kdefs = &selinux_class_perm;
 393         unsigned int i, j;
 394
 395         /*
 396          * Remap extended Netlink classes for old policy versions.
 397          * Do this here rather than socket_type_to_security_class()
 398          * in case a newer policy version is loaded, allowing sockets
 399          * to remain in the correct class.
 400          */
 401         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 402                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 403                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 404                         tclass = SECCLASS_NETLINK_SOCKET;
 405
 406         /*
 407          * Initialize the access vectors to the default values.
 408          */
 409         avd->allowed = 0;
 410         avd->auditallow = 0;
 411         avd->auditdeny = 0xffffffff;
 412         avd->seqno = latest_granting;
 413         avd->flags = 0;
 414
 415         /*
 416          * Check for all the invalid cases.
 417          * - tclass 0
 418          * - tclass > policy and > kernel
 419          * - tclass > policy but is a userspace class
 420          * - tclass > policy but we do not allow unknowns
 421          */
 422         if (unlikely(!tclass))
 423                 goto inval_class;
 424         if (unlikely(tclass > policydb.p_classes.nprim))
 425                 if (tclass > kdefs->cts_len ||
 426                     !kdefs->class_to_string[tclass] ||
 427                     !policydb.allow_unknown)
 428                         goto inval_class;
 429
 430         /*
 431          * Kernel class and we allow unknown so pad the allow decision
 432          * the pad will be all 1 for unknown classes.
 433          */
 434         if (tclass <= kdefs->cts_len && policydb.allow_unknown)
 435                 avd->allowed = policydb.undefined_perms[tclass - 1];
 436
 437         /*
 438          * Not in policy. Since decision is completed (all 1 or all 0) return.
 439          */
 440         if (unlikely(tclass > policydb.p_classes.nprim))
 441                 return 0;
 442
 443         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 444
 445         /*
 446          * If a specific type enforcement rule was defined for
 447          * this permission check, then use it.
 448          */
 449         avkey.target_class = tclass;
 450         avkey.specified = AVTAB_AV;
 451         sattr = &policydb.type_attr_map[scontext->type - 1];
 452         tattr = &policydb.type_attr_map[tcontext->type - 1];
 453         ebitmap_for_each_positive_bit(sattr, snode, i) {
 454                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 455                         avkey.source_type = i + 1;
 456                         avkey.target_type = j + 1;
 457                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 458                              node;
 459                              node = avtab_search_node_next(node, avkey.specified)) {
 460                                 if (node->key.specified == AVTAB_ALLOWED)
 461                                         avd->allowed |= node->datum.data;
 462                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 463                                         avd->auditallow |= node->datum.data;
 464                                 else if (node->key.specified == AVTAB_AUDITDENY)
 465                                         avd->auditdeny &= node->datum.data;
 466                         }
 467
 468                         /* Check conditional av table for additional permissions */
 469                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 470
 471                 }
 472         }
 473
 474         /*
 475          * Remove any permissions prohibited by a constraint (this includes
 476          * the MLS policy).
 477          */
 478         constraint = tclass_datum->constraints;
 479         while (constraint) {
 480                 if ((constraint->permissions & (avd->allowed)) &&
 481                     !constraint_expr_eval(scontext, tcontext, NULL,
 482                                           constraint->expr)) {
 483                         avd->allowed = (avd->allowed) & ~(constraint->permissions);
 484                 }
 485                 constraint = constraint->next;
 486         }
 487
 488         /*
 489          * If checking process transition permission and the
 490          * role is changing, then check the (current_role, new_role)
 491          * pair.
 492          */
 493         if (tclass == SECCLASS_PROCESS &&
 494             (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
 495             scontext->role != tcontext->role) {
 496                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 497                         if (scontext->role == ra->role &&
 498                             tcontext->role == ra->new_role)
 499                                 break;
 500                 }
 501                 if (!ra)
 502                         avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
 503                                                         PROCESS__DYNTRANSITION);
 504         }
 505
 506         /*
 507          * If the given source and target types have boundary
 508          * constraint, lazy checks have to mask any violated
 509          * permission and notice it to userspace via audit.
 510          */
 511         type_attribute_bounds_av(scontext, tcontext,
 512                                  tclass, requested, avd);
 513
 514         return 0;
 515
 516 inval_class:
 517         if (!tclass || tclass > kdefs->cts_len ||
 518             !kdefs->class_to_string[tclass]) {
 519                 if (printk_ratelimit())
 520                         printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 521                                __func__, tclass);
 522                 return -EINVAL;
 523         }
 524
 525         /*
 526          * Known to the kernel, but not to the policy.
 527          * Handle as a denial (allowed is 0).
 528          */
 529         return 0;
 530 }
 531
 532 static int security_validtrans_handle_fail(struct context *ocontext,
 533                                            struct context *ncontext,
 534                                            struct context *tcontext,
 535                                            u16 tclass)
 536 {
 537         char *o = NULL, *n = NULL, *t = NULL;
 538         u32 olen, nlen, tlen;
 539
 540         if (context_struct_to_string(ocontext, &o, &olen) < 0)
 541                 goto out;
 542         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
 543                 goto out;
 544         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 545                 goto out;
 546         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 547                   "security_validate_transition:  denied for"
 548                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 549                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
 550 out:
 551         kfree(o);
 552         kfree(n);
 553         kfree(t);
 554
 555         if (!selinux_enforcing)
 556                 return 0;
 557         return -EPERM;
 558 }
 559
 560 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 561                                  u16 tclass)
 562 {
 563         struct context *ocontext;
 564         struct context *ncontext;
 565         struct context *tcontext;
 566         struct class_datum *tclass_datum;
 567         struct constraint_node *constraint;
 568         int rc = 0;
 569
 570         if (!ss_initialized)
 571                 return 0;
 572
 573         read_lock(&policy_rwlock);
 574
 575         /*
 576          * Remap extended Netlink classes for old policy versions.
 577          * Do this here rather than socket_type_to_security_class()
 578          * in case a newer policy version is loaded, allowing sockets
 579          * to remain in the correct class.
 580          */
 581         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 582                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 583                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 584                         tclass = SECCLASS_NETLINK_SOCKET;
 585
 586         if (!tclass || tclass > policydb.p_classes.nprim) {
 587                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 588                         __func__, tclass);
 589                 rc = -EINVAL;
 590                 goto out;
 591         }
 592         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 593
 594         ocontext = sidtab_search(&sidtab, oldsid);
 595         if (!ocontext) {
 596                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 597                         __func__, oldsid);
 598                 rc = -EINVAL;
 599                 goto out;
 600         }
 601
 602         ncontext = sidtab_search(&sidtab, newsid);
 603         if (!ncontext) {
 604                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 605                         __func__, newsid);
 606                 rc = -EINVAL;
 607                 goto out;
 608         }
 609
 610         tcontext = sidtab_search(&sidtab, tasksid);
 611         if (!tcontext) {
 612                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 613                         __func__, tasksid);
 614                 rc = -EINVAL;
 615                 goto out;
 616         }
 617
 618         constraint = tclass_datum->validatetrans;
 619         while (constraint) {
 620                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 621                                           constraint->expr)) {
 622                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 623                                                              tcontext, tclass);
 624                         goto out;
 625                 }
 626                 constraint = constraint->next;
 627         }
 628
 629 out:
 630         read_unlock(&policy_rwlock);
 631         return rc;
 632 }
 633
 634 /*
 635  * security_bounded_transition - check whether the given
 636  * transition is directed to bounded, or not.
 637  * It returns 0, if @newsid is bounded by @oldsid.
 638  * Otherwise, it returns error code.
 639  *
 640  * @oldsid : current security identifier
 641  * @newsid : destinated security identifier
 642  */
 643 int security_bounded_transition(u32 old_sid, u32 new_sid)
 644 {
 645         struct context *old_context, *new_context;
 646         struct type_datum *type;
 647         int index;
 648         int rc = -EINVAL;
 649
 650         read_lock(&policy_rwlock);
 651
 652         old_context = sidtab_search(&sidtab, old_sid);
 653         if (!old_context) {
 654                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 655                        __func__, old_sid);
 656                 goto out;
 657         }
 658
 659         new_context = sidtab_search(&sidtab, new_sid);
 660         if (!new_context) {
 661                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 662                        __func__, new_sid);
 663                 goto out;
 664         }
 665
 666         /* type/domain unchaned */
 667         if (old_context->type == new_context->type) {
 668                 rc = 0;
 669                 goto out;
 670         }
 671
 672         index = new_context->type;
 673         while (true) {
 674                 type = policydb.type_val_to_struct[index - 1];
 675                 BUG_ON(!type);
 676
 677                 /* not bounded anymore */
 678                 if (!type->bounds) {
 679                         rc = -EPERM;
 680                         break;
 681                 }
 682
 683                 /* @newsid is bounded by @oldsid */
 684                 if (type->bounds == old_context->type) {
 685                         rc = 0;
 686                         break;
 687                 }
 688                 index = type->bounds;
 689         }
 690 out:
 691         read_unlock(&policy_rwlock);
 692
 693         return rc;
 694 }
 695
 696
 697 /**
 698  * security_compute_av - Compute access vector decisions.
 699  * @ssid: source security identifier
 700  * @tsid: target security identifier
 701  * @tclass: target security class
 702  * @requested: requested permissions
 703  * @avd: access vector decisions
 704  *
 705  * Compute a set of access vector decisions based on the
 706  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 707  * Return -%EINVAL if any of the parameters are invalid or %0
 708  * if the access vector decisions were computed successfully.
 709  */
 710 int security_compute_av(u32 ssid,
 711                         u32 tsid,
 712                         u16 tclass,
 713                         u32 requested,
 714                         struct av_decision *avd)
 715 {
 716         struct context *scontext = NULL, *tcontext = NULL;
 717         int rc = 0;
 718
 719         if (!ss_initialized) {
 720                 avd->allowed = 0xffffffff;
 721                 avd->auditallow = 0;
 722                 avd->auditdeny = 0xffffffff;
 723                 avd->seqno = latest_granting;
 724                 return 0;
 725         }
 726
 727         read_lock(&policy_rwlock);
 728
 729         scontext = sidtab_search(&sidtab, ssid);
 730         if (!scontext) {
 731                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 732                        __func__, ssid);
 733                 rc = -EINVAL;
 734                 goto out;
 735         }
 736         tcontext = sidtab_search(&sidtab, tsid);
 737         if (!tcontext) {
 738                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 739                        __func__, tsid);
 740                 rc = -EINVAL;
 741                 goto out;
 742         }
 743
 744         rc = context_struct_compute_av(scontext, tcontext, tclass,
 745                                        requested, avd);
 746
 747         /* permissive domain? */
 748         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 749             avd->flags |= AVD_FLAGS_PERMISSIVE;
 750 out:
 751         read_unlock(&policy_rwlock);
 752         return rc;
 753 }
 754
 755 /*
 756  * Write the security context string representation of
 757  * the context structure `context' into a dynamically
 758  * allocated string of the correct size.  Set `*scontext'
 759  * to point to this string and set `*scontext_len' to
 760  * the length of the string.
 761  */
 762 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
 763 {
 764         char *scontextp;
 765
 766         *scontext = NULL;
 767         *scontext_len = 0;
 768
 769         if (context->len) {
 770                 *scontext_len = context->len;
 771                 *scontext = kstrdup(context->str, GFP_ATOMIC);
 772                 if (!(*scontext))
 773                         return -ENOMEM;
 774                 return 0;
 775         }
 776
 777         /* Compute the size of the context. */
 778         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
 779         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
 780         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
 781         *scontext_len += mls_compute_context_len(context);
 782
 783         /* Allocate space for the context; caller must free this space. */
 784         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
 785         if (!scontextp)
 786                 return -ENOMEM;
 787         *scontext = scontextp;
 788
 789         /*
 790          * Copy the user name, role name and type name into the context.
 791          */
 792         sprintf(scontextp, "%s:%s:%s",
 793                 policydb.p_user_val_to_name[context->user - 1],
 794                 policydb.p_role_val_to_name[context->role - 1],
 795                 policydb.p_type_val_to_name[context->type - 1]);
 796         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
 797                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
 798                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
 799
 800         mls_sid_to_context(context, &scontextp);
 801
 802         *scontextp = 0;
 803
 804         return 0;
 805 }
 806
 807 #include "initial_sid_to_string.h"
 808
 809 const char *security_get_initial_sid_context(u32 sid)
 810 {
 811         if (unlikely(sid > SECINITSID_NUM))
 812                 return NULL;
 813         return initial_sid_to_string[sid];
 814 }
 815
 816 static int security_sid_to_context_core(u32 sid, char **scontext,
 817                                         u32 *scontext_len, int force)
 818 {
 819         struct context *context;
 820         int rc = 0;
 821
 822         *scontext = NULL;
 823         *scontext_len  = 0;
 824
 825         if (!ss_initialized) {
 826                 if (sid <= SECINITSID_NUM) {
 827                         char *scontextp;
 828
 829                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
 830                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
 831                         if (!scontextp) {
 832                                 rc = -ENOMEM;
 833                                 goto out;
 834                         }
 835                         strcpy(scontextp, initial_sid_to_string[sid]);
 836                         *scontext = scontextp;
 837                         goto out;
 838                 }
 839                 printk(KERN_ERR "SELinux: %s:  called before initial "
 840                        "load_policy on unknown SID %d\n", __func__, sid);
 841                 rc = -EINVAL;
 842                 goto out;
 843         }
 844         read_lock(&policy_rwlock);
 845         if (force)
 846                 context = sidtab_search_force(&sidtab, sid);
 847         else
 848                 context = sidtab_search(&sidtab, sid);
 849         if (!context) {
 850                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 851                         __func__, sid);
 852                 rc = -EINVAL;
 853                 goto out_unlock;
 854         }
 855         rc = context_struct_to_string(context, scontext, scontext_len);
 856 out_unlock:
 857         read_unlock(&policy_rwlock);
 858 out:
 859         return rc;
 860
 861 }
 862
 863 /**
 864  * security_sid_to_context - Obtain a context for a given SID.
 865  * @sid: security identifier, SID
 866  * @scontext: security context
 867  * @scontext_len: length in bytes
 868  *
 869  * Write the string representation of the context associated with @sid
 870  * into a dynamically allocated string of the correct size.  Set @scontext
 871  * to point to this string and set @scontext_len to the length of the string.
 872  */
 873 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
 874 {
 875         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
 876 }
 877
 878 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
 879 {
 880         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
 881 }
 882
 883 /*
 884  * Caveat:  Mutates scontext.
 885  */
 886 static int string_to_context_struct(struct policydb *pol,
 887                                     struct sidtab *sidtabp,
 888                                     char *scontext,
 889                                     u32 scontext_len,
 890                                     struct context *ctx,
 891                                     u32 def_sid)
 892 {
 893         struct role_datum *role;
 894         struct type_datum *typdatum;
 895         struct user_datum *usrdatum;
 896         char *scontextp, *p, oldc;
 897         int rc = 0;
 898
 899         context_init(ctx);
 900
 901         /* Parse the security context. */
 902
 903         rc = -EINVAL;
 904         scontextp = (char *) scontext;
 905
 906         /* Extract the user. */
 907         p = scontextp;
 908         while (*p && *p != ':')
 909                 p++;
 910
 911         if (*p == 0)
 912                 goto out;
 913
 914         *p++ = 0;
 915
 916         usrdatum = hashtab_search(pol->p_users.table, scontextp);
 917         if (!usrdatum)
 918                 goto out;
 919
 920         ctx->user = usrdatum->value;
 921
 922         /* Extract role. */
 923         scontextp = p;
 924         while (*p && *p != ':')
 925                 p++;
 926
 927         if (*p == 0)
 928                 goto out;
 929
 930         *p++ = 0;
 931
 932         role = hashtab_search(pol->p_roles.table, scontextp);
 933         if (!role)
 934                 goto out;
 935         ctx->role = role->value;
 936
 937         /* Extract type. */
 938         scontextp = p;
 939         while (*p && *p != ':')
 940                 p++;
 941         oldc = *p;
 942         *p++ = 0;
 943
 944         typdatum = hashtab_search(pol->p_types.table, scontextp);
 945         if (!typdatum || typdatum->attribute)
 946                 goto out;
 947
 948         ctx->type = typdatum->value;
 949
 950         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
 951         if (rc)
 952                 goto out;
 953
 954         if ((p - scontext) < scontext_len) {
 955                 rc = -EINVAL;
 956                 goto out;
 957         }
 958
 959         /* Check the validity of the new context. */
 960         if (!policydb_context_isvalid(pol, ctx)) {
 961                 rc = -EINVAL;
 962                 goto out;
 963         }
 964         rc = 0;
 965 out:
 966         if (rc)
 967                 context_destroy(ctx);
 968         return rc;
 969 }
 970
 971 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
 972                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
 973                                         int force)
 974 {
 975         char *scontext2, *str = NULL;
 976         struct context context;
 977         int rc = 0;
 978
 979         if (!ss_initialized) {
 980                 int i;
 981
 982                 for (i = 1; i < SECINITSID_NUM; i++) {
 983                         if (!strcmp(initial_sid_to_string[i], scontext)) {
 984                                 *sid = i;
 985                                 return 0;
 986                         }
 987                 }
 988                 *sid = SECINITSID_KERNEL;
 989                 return 0;
 990         }
 991         *sid = SECSID_NULL;
 992
 993         /* Copy the string so that we can modify the copy as we parse it. */
 994         scontext2 = kmalloc(scontext_len+1, gfp_flags);
 995         if (!scontext2)
 996                 return -ENOMEM;
 997         memcpy(scontext2, scontext, scontext_len);
 998         scontext2[scontext_len] = 0;
 999
1000         if (force) {
1001                 /* Save another copy for storing in uninterpreted form */
1002                 str = kstrdup(scontext2, gfp_flags);
1003                 if (!str) {
1004                         kfree(scontext2);
1005                         return -ENOMEM;
1006                 }
1007         }
1008
1009         read_lock(&policy_rwlock);
1010         rc = string_to_context_struct(&policydb, &sidtab,
1011                                       scontext2, scontext_len,
1012                                       &context, def_sid);
1013         if (rc == -EINVAL && force) {
1014                 context.str = str;
1015                 context.len = scontext_len;
1016                 str = NULL;
1017         } else if (rc)
1018                 goto out;
1019         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1020         context_destroy(&context);
1021 out:
1022         read_unlock(&policy_rwlock);
1023         kfree(scontext2);
1024         kfree(str);
1025         return rc;
1026 }
1027
1028 /**
1029  * security_context_to_sid - Obtain a SID for a given security context.
1030  * @scontext: security context
1031  * @scontext_len: length in bytes
1032  * @sid: security identifier, SID
1033  *
1034  * Obtains a SID associated with the security context that
1035  * has the string representation specified by @scontext.
1036  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1037  * memory is available, or 0 on success.
1038  */
1039 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1040 {
1041         return security_context_to_sid_core(scontext, scontext_len,
1042                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1043 }
1044
1045 /**
1046  * security_context_to_sid_default - Obtain a SID for a given security context,
1047  * falling back to specified default if needed.
1048  *
1049  * @scontext: security context
1050  * @scontext_len: length in bytes
1051  * @sid: security identifier, SID
1052  * @def_sid: default SID to assign on error
1053  *
1054  * Obtains a SID associated with the security context that
1055  * has the string representation specified by @scontext.
1056  * The default SID is passed to the MLS layer to be used to allow
1057  * kernel labeling of the MLS field if the MLS field is not present
1058  * (for upgrading to MLS without full relabel).
1059  * Implicitly forces adding of the context even if it cannot be mapped yet.
1060  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1061  * memory is available, or 0 on success.
1062  */
1063 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1064                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1065 {
1066         return security_context_to_sid_core(scontext, scontext_len,
1067                                             sid, def_sid, gfp_flags, 1);
1068 }
1069
1070 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1071                                   u32 *sid)
1072 {
1073         return security_context_to_sid_core(scontext, scontext_len,
1074                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1075 }
1076
1077 static int compute_sid_handle_invalid_context(
1078         struct context *scontext,
1079         struct context *tcontext,
1080         u16 tclass,
1081         struct context *newcontext)
1082 {
1083         char *s = NULL, *t = NULL, *n = NULL;
1084         u32 slen, tlen, nlen;
1085
1086         if (context_struct_to_string(scontext, &s, &slen) < 0)
1087                 goto out;
1088         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
1089                 goto out;
1090         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
1091                 goto out;
1092         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1093                   "security_compute_sid:  invalid context %s"
1094                   " for scontext=%s"
1095                   " tcontext=%s"
1096                   " tclass=%s",
1097                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
1098 out:
1099         kfree(s);
1100         kfree(t);
1101         kfree(n);
1102         if (!selinux_enforcing)
1103                 return 0;
1104         return -EACCES;
1105 }
1106
1107 static int security_compute_sid(u32 ssid,
1108                                 u32 tsid,
1109                                 u16 tclass,
1110                                 u32 specified,
1111                                 u32 *out_sid)
1112 {
1113         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1114         struct role_trans *roletr = NULL;
1115         struct avtab_key avkey;
1116         struct avtab_datum *avdatum;
1117         struct avtab_node *node;
1118         int rc = 0;
1119
1120         if (!ss_initialized) {
1121                 switch (tclass) {
1122                 case SECCLASS_PROCESS:
1123                         *out_sid = ssid;
1124                         break;
1125                 default:
1126                         *out_sid = tsid;
1127                         break;
1128                 }
1129                 goto out;
1130         }
1131
1132         context_init(&newcontext);
1133
1134         read_lock(&policy_rwlock);
1135
1136         scontext = sidtab_search(&sidtab, ssid);
1137         if (!scontext) {
1138                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1139                        __func__, ssid);
1140                 rc = -EINVAL;
1141                 goto out_unlock;
1142         }
1143         tcontext = sidtab_search(&sidtab, tsid);
1144         if (!tcontext) {
1145                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1146                        __func__, tsid);
1147                 rc = -EINVAL;
1148                 goto out_unlock;
1149         }
1150
1151         /* Set the user identity. */
1152         switch (specified) {
1153         case AVTAB_TRANSITION:
1154         case AVTAB_CHANGE:
1155                 /* Use the process user identity. */
1156                 newcontext.user = scontext->user;
1157                 break;
1158         case AVTAB_MEMBER:
1159                 /* Use the related object owner. */
1160                 newcontext.user = tcontext->user;
1161                 break;
1162         }
1163
1164         /* Set the role and type to default values. */
1165         switch (tclass) {
1166         case SECCLASS_PROCESS:
1167                 /* Use the current role and type of process. */
1168                 newcontext.role = scontext->role;
1169                 newcontext.type = scontext->type;
1170                 break;
1171         default:
1172                 /* Use the well-defined object role. */
1173                 newcontext.role = OBJECT_R_VAL;
1174                 /* Use the type of the related object. */
1175                 newcontext.type = tcontext->type;
1176         }
1177
1178         /* Look for a type transition/member/change rule. */
1179         avkey.source_type = scontext->type;
1180         avkey.target_type = tcontext->type;
1181         avkey.target_class = tclass;
1182         avkey.specified = specified;
1183         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1184
1185         /* If no permanent rule, also check for enabled conditional rules */
1186         if (!avdatum) {
1187                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1188                 for (; node; node = avtab_search_node_next(node, specified)) {
1189                         if (node->key.specified & AVTAB_ENABLED) {
1190                                 avdatum = &node->datum;
1191                                 break;
1192                         }
1193                 }
1194         }
1195
1196         if (avdatum) {
1197                 /* Use the type from the type transition/member/change rule. */
1198                 newcontext.type = avdatum->data;
1199         }
1200
1201         /* Check for class-specific changes. */
1202         switch (tclass) {
1203         case SECCLASS_PROCESS:
1204                 if (specified & AVTAB_TRANSITION) {
1205                         /* Look for a role transition rule. */
1206                         for (roletr = policydb.role_tr; roletr;
1207                              roletr = roletr->next) {
1208                                 if (roletr->role == scontext->role &&
1209                                     roletr->type == tcontext->type) {
1210                                         /* Use the role transition rule. */
1211                                         newcontext.role = roletr->new_role;
1212                                         break;
1213                                 }
1214                         }
1215                 }
1216                 break;
1217         default:
1218                 break;
1219         }
1220
1221         /* Set the MLS attributes.
1222            This is done last because it may allocate memory. */
1223         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1224         if (rc)
1225                 goto out_unlock;
1226
1227         /* Check the validity of the context. */
1228         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1229                 rc = compute_sid_handle_invalid_context(scontext,
1230                                                         tcontext,
1231                                                         tclass,
1232                                                         &newcontext);
1233                 if (rc)
1234                         goto out_unlock;
1235         }
1236         /* Obtain the sid for the context. */
1237         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1238 out_unlock:
1239         read_unlock(&policy_rwlock);
1240         context_destroy(&newcontext);
1241 out:
1242         return rc;
1243 }
1244
1245 /**
1246  * security_transition_sid - Compute the SID for a new subject/object.
1247  * @ssid: source security identifier
1248  * @tsid: target security identifier
1249  * @tclass: target security class
1250  * @out_sid: security identifier for new subject/object
1251  *
1252  * Compute a SID to use for labeling a new subject or object in the
1253  * class @tclass based on a SID pair (@ssid, @tsid).
1254  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1255  * if insufficient memory is available, or %0 if the new SID was
1256  * computed successfully.
1257  */
1258 int security_transition_sid(u32 ssid,
1259                             u32 tsid,
1260                             u16 tclass,
1261                             u32 *out_sid)
1262 {
1263         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1264 }
1265
1266 /**
1267  * security_member_sid - Compute the SID for member selection.
1268  * @ssid: source security identifier
1269  * @tsid: target security identifier
1270  * @tclass: target security class
1271  * @out_sid: security identifier for selected member
1272  *
1273  * Compute a SID to use when selecting a member of a polyinstantiated
1274  * object of class @tclass based on a SID pair (@ssid, @tsid).
1275  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1276  * if insufficient memory is available, or %0 if the SID was
1277  * computed successfully.
1278  */
1279 int security_member_sid(u32 ssid,
1280                         u32 tsid,
1281                         u16 tclass,
1282                         u32 *out_sid)
1283 {
1284         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1285 }
1286
1287 /**
1288  * security_change_sid - Compute the SID for object relabeling.
1289  * @ssid: source security identifier
1290  * @tsid: target security identifier
1291  * @tclass: target security class
1292  * @out_sid: security identifier for selected member
1293  *
1294  * Compute a SID to use for relabeling an object of class @tclass
1295  * based on a SID pair (@ssid, @tsid).
1296  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1297  * if insufficient memory is available, or %0 if the SID was
1298  * computed successfully.
1299  */
1300 int security_change_sid(u32 ssid,
1301                         u32 tsid,
1302                         u16 tclass,
1303                         u32 *out_sid)
1304 {
1305         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1306 }
1307
1308 /*
1309  * Verify that each kernel class that is defined in the
1310  * policy is correct
1311  */
1312 static int validate_classes(struct policydb *p)
1313 {
1314         int i, j;
1315         struct class_datum *cladatum;
1316         struct perm_datum *perdatum;
1317         u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1318         u16 class_val;
1319         const struct selinux_class_perm *kdefs = &selinux_class_perm;
1320         const char *def_class, *def_perm, *pol_class;
1321         struct symtab *perms;
1322         bool print_unknown_handle = 0;
1323
1324         if (p->allow_unknown) {
1325                 u32 num_classes = kdefs->cts_len;
1326                 p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1327                 if (!p->undefined_perms)
1328                         return -ENOMEM;
1329         }
1330
1331         for (i = 1; i < kdefs->cts_len; i++) {
1332                 def_class = kdefs->class_to_string[i];
1333                 if (!def_class)
1334                         continue;
1335                 if (i > p->p_classes.nprim) {
1336                         printk(KERN_INFO
1337                                "SELinux:  class %s not defined in policy\n",
1338                                def_class);
1339                         if (p->reject_unknown)
1340                                 return -EINVAL;
1341                         if (p->allow_unknown)
1342                                 p->undefined_perms[i-1] = ~0U;
1343                         print_unknown_handle = 1;
1344                         continue;
1345                 }
1346                 pol_class = p->p_class_val_to_name[i-1];
1347                 if (strcmp(pol_class, def_class)) {
1348                         printk(KERN_ERR
1349                                "SELinux:  class %d is incorrect, found %s but should be %s\n",
1350                                i, pol_class, def_class);
1351                         return -EINVAL;
1352                 }
1353         }
1354         for (i = 0; i < kdefs->av_pts_len; i++) {
1355                 class_val = kdefs->av_perm_to_string[i].tclass;
1356                 perm_val = kdefs->av_perm_to_string[i].value;
1357                 def_perm = kdefs->av_perm_to_string[i].name;
1358                 if (class_val > p->p_classes.nprim)
1359                         continue;
1360                 pol_class = p->p_class_val_to_name[class_val-1];
1361                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1362                 BUG_ON(!cladatum);
1363                 perms = &cladatum->permissions;
1364                 nprim = 1 << (perms->nprim - 1);
1365                 if (perm_val > nprim) {
1366                         printk(KERN_INFO
1367                                "SELinux:  permission %s in class %s not defined in policy\n",
1368                                def_perm, pol_class);
1369                         if (p->reject_unknown)
1370                                 return -EINVAL;
1371                         if (p->allow_unknown)
1372                                 p->undefined_perms[class_val-1] |= perm_val;
1373                         print_unknown_handle = 1;
1374                         continue;
1375                 }
1376                 perdatum = hashtab_search(perms->table, def_perm);
1377                 if (perdatum == NULL) {
1378                         printk(KERN_ERR
1379                                "SELinux:  permission %s in class %s not found in policy, bad policy\n",
1380                                def_perm, pol_class);
1381                         return -EINVAL;
1382                 }
1383                 pol_val = 1 << (perdatum->value - 1);
1384                 if (pol_val != perm_val) {
1385                         printk(KERN_ERR
1386                                "SELinux:  permission %s in class %s has incorrect value\n",
1387                                def_perm, pol_class);
1388                         return -EINVAL;
1389                 }
1390         }
1391         for (i = 0; i < kdefs->av_inherit_len; i++) {
1392                 class_val = kdefs->av_inherit[i].tclass;
1393                 if (class_val > p->p_classes.nprim)
1394                         continue;
1395                 pol_class = p->p_class_val_to_name[class_val-1];
1396                 cladatum = hashtab_search(p->p_classes.table, pol_class);
1397                 BUG_ON(!cladatum);
1398                 if (!cladatum->comdatum) {
1399                         printk(KERN_ERR
1400                                "SELinux:  class %s should have an inherits clause but does not\n",
1401                                pol_class);
1402                         return -EINVAL;
1403                 }
1404                 tmp = kdefs->av_inherit[i].common_base;
1405                 common_pts_len = 0;
1406                 while (!(tmp & 0x01)) {
1407                         common_pts_len++;
1408                         tmp >>= 1;
1409                 }
1410                 perms = &cladatum->comdatum->permissions;
1411                 for (j = 0; j < common_pts_len; j++) {
1412                         def_perm = kdefs->av_inherit[i].common_pts[j];
1413                         if (j >= perms->nprim) {
1414                                 printk(KERN_INFO
1415                                        "SELinux:  permission %s in class %s not defined in policy\n",
1416                                        def_perm, pol_class);
1417                                 if (p->reject_unknown)
1418                                         return -EINVAL;
1419                                 if (p->allow_unknown)
1420                                         p->undefined_perms[class_val-1] |= (1 << j);
1421                                 print_unknown_handle = 1;
1422                                 continue;
1423                         }
1424                         perdatum = hashtab_search(perms->table, def_perm);
1425                         if (perdatum == NULL) {
1426                                 printk(KERN_ERR
1427                                        "SELinux:  permission %s in class %s not found in policy, bad policy\n",
1428                                        def_perm, pol_class);
1429                                 return -EINVAL;
1430                         }
1431                         if (perdatum->value != j + 1) {
1432                                 printk(KERN_ERR
1433                                        "SELinux:  permission %s in class %s has incorrect value\n",
1434                                        def_perm, pol_class);
1435                                 return -EINVAL;
1436                         }
1437                 }
1438         }
1439         if (print_unknown_handle)
1440                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
1441                         (security_get_allow_unknown() ? "allowed" : "denied"));
1442         return 0;
1443 }
1444
1445 /* Clone the SID into the new SID table. */
1446 static int clone_sid(u32 sid,
1447                      struct context *context,
1448                      void *arg)
1449 {
1450         struct sidtab *s = arg;
1451
1452         return sidtab_insert(s, sid, context);
1453 }
1454
1455 static inline int convert_context_handle_invalid_context(struct context *context)
1456 {
1457         int rc = 0;
1458
1459         if (selinux_enforcing) {
1460                 rc = -EINVAL;
1461         } else {
1462                 char *s;
1463                 u32 len;
1464
1465                 if (!context_struct_to_string(context, &s, &len)) {
1466                         printk(KERN_WARNING
1467                        "SELinux:  Context %s would be invalid if enforcing\n",
1468                                s);
1469                         kfree(s);
1470                 }
1471         }
1472         return rc;
1473 }
1474
1475 struct convert_context_args {
1476         struct policydb *oldp;
1477         struct policydb *newp;
1478 };
1479
1480 /*
1481  * Convert the values in the security context
1482  * structure `c' from the values specified
1483  * in the policy `p->oldp' to the values specified
1484  * in the policy `p->newp'.  Verify that the
1485  * context is valid under the new policy.
1486  */
1487 static int convert_context(u32 key,
1488                            struct context *c,
1489                            void *p)
1490 {
1491         struct convert_context_args *args;
1492         struct context oldc;
1493         struct role_datum *role;
1494         struct type_datum *typdatum;
1495         struct user_datum *usrdatum;
1496         char *s;
1497         u32 len;
1498         int rc;
1499
1500         args = p;
1501
1502         if (c->str) {
1503                 struct context ctx;
1504                 s = kstrdup(c->str, GFP_KERNEL);
1505                 if (!s) {
1506                         rc = -ENOMEM;
1507                         goto out;
1508                 }
1509                 rc = string_to_context_struct(args->newp, NULL, s,
1510                                               c->len, &ctx, SECSID_NULL);
1511                 kfree(s);
1512                 if (!rc) {
1513                         printk(KERN_INFO
1514                        "SELinux:  Context %s became valid (mapped).\n",
1515                                c->str);
1516                         /* Replace string with mapped representation. */
1517                         kfree(c->str);
1518                         memcpy(c, &ctx, sizeof(*c));
1519                         goto out;
1520                 } else if (rc == -EINVAL) {
1521                         /* Retain string representation for later mapping. */
1522                         rc = 0;
1523                         goto out;
1524                 } else {
1525                         /* Other error condition, e.g. ENOMEM. */
1526                         printk(KERN_ERR
1527                        "SELinux:   Unable to map context %s, rc = %d.\n",
1528                                c->str, -rc);
1529                         goto out;
1530                 }
1531         }
1532
1533         rc = context_cpy(&oldc, c);
1534         if (rc)
1535                 goto out;
1536
1537         rc = -EINVAL;
1538
1539         /* Convert the user. */
1540         usrdatum = hashtab_search(args->newp->p_users.table,
1541                                   args->oldp->p_user_val_to_name[c->user - 1]);
1542         if (!usrdatum)
1543                 goto bad;
1544         c->user = usrdatum->value;
1545
1546         /* Convert the role. */
1547         role = hashtab_search(args->newp->p_roles.table,
1548                               args->oldp->p_role_val_to_name[c->role - 1]);
1549         if (!role)
1550                 goto bad;
1551         c->role = role->value;
1552
1553         /* Convert the type. */
1554         typdatum = hashtab_search(args->newp->p_types.table,
1555                                   args->oldp->p_type_val_to_name[c->type - 1]);
1556         if (!typdatum)
1557                 goto bad;
1558         c->type = typdatum->value;
1559
1560         rc = mls_convert_context(args->oldp, args->newp, c);
1561         if (rc)
1562                 goto bad;
1563
1564         /* Check the validity of the new context. */
1565         if (!policydb_context_isvalid(args->newp, c)) {
1566                 rc = convert_context_handle_invalid_context(&oldc);
1567                 if (rc)
1568                         goto bad;
1569         }
1570
1571         context_destroy(&oldc);
1572         rc = 0;
1573 out:
1574         return rc;
1575 bad:
1576         /* Map old representation to string and save it. */
1577         if (context_struct_to_string(&oldc, &s, &len))
1578                 return -ENOMEM;
1579         context_destroy(&oldc);
1580         context_destroy(c);
1581         c->str = s;
1582         c->len = len;
1583         printk(KERN_INFO
1584                "SELinux:  Context %s became invalid (unmapped).\n",
1585                c->str);
1586         rc = 0;
1587         goto out;
1588 }
1589
1590 static void security_load_policycaps(void)
1591 {
1592         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1593                                                   POLICYDB_CAPABILITY_NETPEER);
1594         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1595                                                   POLICYDB_CAPABILITY_OPENPERM);
1596 }
1597
1598 extern void selinux_complete_init(void);
1599 static int security_preserve_bools(struct policydb *p);
1600
1601 /**
1602  * security_load_policy - Load a security policy configuration.
1603  * @data: binary policy data
1604  * @len: length of data in bytes
1605  *
1606  * Load a new set of security policy configuration data,
1607  * validate it and convert the SID table as necessary.
1608  * This function will flush the access vector cache after
1609  * loading the new policy.
1610  */
1611 int security_load_policy(void *data, size_t len)
1612 {
1613         struct policydb oldpolicydb, newpolicydb;
1614         struct sidtab oldsidtab, newsidtab;
1615         struct convert_context_args args;
1616         u32 seqno;
1617         int rc = 0;
1618         struct policy_file file = { data, len }, *fp = &file;
1619
1620         if (!ss_initialized) {
1621                 avtab_cache_init();
1622                 if (policydb_read(&policydb, fp)) {
1623                         avtab_cache_destroy();
1624                         return -EINVAL;
1625                 }
1626                 if (policydb_load_isids(&policydb, &sidtab)) {
1627                         policydb_destroy(&policydb);
1628                         avtab_cache_destroy();
1629                         return -EINVAL;
1630                 }
1631                 /* Verify that the kernel defined classes are correct. */
1632                 if (validate_classes(&policydb)) {
1633                         printk(KERN_ERR
1634                                "SELinux:  the definition of a class is incorrect\n");
1635                         sidtab_destroy(&sidtab);
1636                         policydb_destroy(&policydb);
1637                         avtab_cache_destroy();
1638                         return -EINVAL;
1639                 }
1640                 security_load_policycaps();
1641                 policydb_loaded_version = policydb.policyvers;
1642                 ss_initialized = 1;
1643                 seqno = ++latest_granting;
1644                 selinux_complete_init();
1645                 avc_ss_reset(seqno);
1646                 selnl_notify_policyload(seqno);
1647                 selinux_netlbl_cache_invalidate();
1648                 selinux_xfrm_notify_policyload();
1649                 return 0;
1650         }
1651
1652 #if 0
1653         sidtab_hash_eval(&sidtab, "sids");
1654 #endif
1655
1656         if (policydb_read(&newpolicydb, fp))
1657                 return -EINVAL;
1658
1659         if (sidtab_init(&newsidtab)) {
1660                 policydb_destroy(&newpolicydb);
1661                 return -ENOMEM;
1662         }
1663
1664         /* Verify that the kernel defined classes are correct. */
1665         if (validate_classes(&newpolicydb)) {
1666                 printk(KERN_ERR
1667                        "SELinux:  the definition of a class is incorrect\n");
1668                 rc = -EINVAL;
1669                 goto err;
1670         }
1671
1672         rc = security_preserve_bools(&newpolicydb);
1673         if (rc) {
1674                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1675                 goto err;
1676         }
1677
1678         /* Clone the SID table. */
1679         sidtab_shutdown(&sidtab);
1680         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1681                 rc = -ENOMEM;
1682                 goto err;
1683         }
1684
1685         /*
1686          * Convert the internal representations of contexts
1687          * in the new SID table.
1688          */
1689         args.oldp = &policydb;
1690         args.newp = &newpolicydb;
1691         rc = sidtab_map(&newsidtab, convert_context, &args);
1692         if (rc)
1693                 goto err;
1694
1695         /* Save the old policydb and SID table to free later. */
1696         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1697         sidtab_set(&oldsidtab, &sidtab);
1698
1699         /* Install the new policydb and SID table. */
1700         write_lock_irq(&policy_rwlock);
1701         memcpy(&policydb, &newpolicydb, sizeof policydb);
1702         sidtab_set(&sidtab, &newsidtab);
1703         security_load_policycaps();
1704         seqno = ++latest_granting;
1705         policydb_loaded_version = policydb.policyvers;
1706         write_unlock_irq(&policy_rwlock);
1707
1708         /* Free the old policydb and SID table. */
1709         policydb_destroy(&oldpolicydb);
1710         sidtab_destroy(&oldsidtab);
1711
1712         avc_ss_reset(seqno);
1713         selnl_notify_policyload(seqno);
1714         selinux_netlbl_cache_invalidate();
1715         selinux_xfrm_notify_policyload();
1716
1717         return 0;
1718
1719 err:
1720         sidtab_destroy(&newsidtab);
1721         policydb_destroy(&newpolicydb);
1722         return rc;
1723
1724 }
1725
1726 /**
1727  * security_port_sid - Obtain the SID for a port.
1728  * @protocol: protocol number
1729  * @port: port number
1730  * @out_sid: security identifier
1731  */
1732 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1733 {
1734         struct ocontext *c;
1735         int rc = 0;
1736
1737         read_lock(&policy_rwlock);
1738
1739         c = policydb.ocontexts[OCON_PORT];
1740         while (c) {
1741                 if (c->u.port.protocol == protocol &&
1742                     c->u.port.low_port <= port &&
1743                     c->u.port.high_port >= port)
1744                         break;
1745                 c = c->next;
1746         }
1747
1748         if (c) {
1749                 if (!c->sid[0]) {
1750                         rc = sidtab_context_to_sid(&sidtab,
1751                                                    &c->context[0],
1752                                                    &c->sid[0]);
1753                         if (rc)
1754                                 goto out;
1755                 }
1756                 *out_sid = c->sid[0];
1757         } else {
1758                 *out_sid = SECINITSID_PORT;
1759         }
1760
1761 out:
1762         read_unlock(&policy_rwlock);
1763         return rc;
1764 }
1765
1766 /**
1767  * security_netif_sid - Obtain the SID for a network interface.
1768  * @name: interface name
1769  * @if_sid: interface SID
1770  */
1771 int security_netif_sid(char *name, u32 *if_sid)
1772 {
1773         int rc = 0;
1774         struct ocontext *c;
1775
1776         read_lock(&policy_rwlock);
1777
1778         c = policydb.ocontexts[OCON_NETIF];
1779         while (c) {
1780                 if (strcmp(name, c->u.name) == 0)
1781                         break;
1782                 c = c->next;
1783         }
1784
1785         if (c) {
1786                 if (!c->sid[0] || !c->sid[1]) {
1787                         rc = sidtab_context_to_sid(&sidtab,
1788                                                   &c->context[0],
1789                                                   &c->sid[0]);
1790                         if (rc)
1791                                 goto out;
1792                         rc = sidtab_context_to_sid(&sidtab,
1793                                                    &c->context[1],
1794                                                    &c->sid[1]);
1795                         if (rc)
1796                                 goto out;
1797                 }
1798                 *if_sid = c->sid[0];
1799         } else
1800                 *if_sid = SECINITSID_NETIF;
1801
1802 out:
1803         read_unlock(&policy_rwlock);
1804         return rc;
1805 }
1806
1807 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1808 {
1809         int i, fail = 0;
1810
1811         for (i = 0; i < 4; i++)
1812                 if (addr[i] != (input[i] & mask[i])) {
1813                         fail = 1;
1814                         break;
1815                 }
1816
1817         return !fail;
1818 }
1819
1820 /**
1821  * security_node_sid - Obtain the SID for a node (host).
1822  * @domain: communication domain aka address family
1823  * @addrp: address
1824  * @addrlen: address length in bytes
1825  * @out_sid: security identifier
1826  */
1827 int security_node_sid(u16 domain,
1828                       void *addrp,
1829                       u32 addrlen,
1830                       u32 *out_sid)
1831 {
1832         int rc = 0;
1833         struct ocontext *c;
1834
1835         read_lock(&policy_rwlock);
1836
1837         switch (domain) {
1838         case AF_INET: {
1839                 u32 addr;
1840
1841                 if (addrlen != sizeof(u32)) {
1842                         rc = -EINVAL;
1843                         goto out;
1844                 }
1845
1846                 addr = *((u32 *)addrp);
1847
1848                 c = policydb.ocontexts[OCON_NODE];
1849                 while (c) {
1850                         if (c->u.node.addr == (addr & c->u.node.mask))
1851                                 break;
1852                         c = c->next;
1853                 }
1854                 break;
1855         }
1856
1857         case AF_INET6:
1858                 if (addrlen != sizeof(u64) * 2) {
1859                         rc = -EINVAL;
1860                         goto out;
1861                 }
1862                 c = policydb.ocontexts[OCON_NODE6];
1863                 while (c) {
1864                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1865                                                 c->u.node6.mask))
1866                                 break;
1867                         c = c->next;
1868                 }
1869                 break;
1870
1871         default:
1872                 *out_sid = SECINITSID_NODE;
1873                 goto out;
1874         }
1875
1876         if (c) {
1877                 if (!c->sid[0]) {
1878                         rc = sidtab_context_to_sid(&sidtab,
1879                                                    &c->context[0],
1880                                                    &c->sid[0]);
1881                         if (rc)
1882                                 goto out;
1883                 }
1884                 *out_sid = c->sid[0];
1885         } else {
1886                 *out_sid = SECINITSID_NODE;
1887         }
1888
1889 out:
1890         read_unlock(&policy_rwlock);
1891         return rc;
1892 }
1893
1894 #define SIDS_NEL 25
1895
1896 /**
1897  * security_get_user_sids - Obtain reachable SIDs for a user.
1898  * @fromsid: starting SID
1899  * @username: username
1900  * @sids: array of reachable SIDs for user
1901  * @nel: number of elements in @sids
1902  *
1903  * Generate the set of SIDs for legal security contexts
1904  * for a given user that can be reached by @fromsid.
1905  * Set *@sids to point to a dynamically allocated
1906  * array containing the set of SIDs.  Set *@nel to the
1907  * number of elements in the array.
1908  */
1909
1910 int security_get_user_sids(u32 fromsid,
1911                            char *username,
1912                            u32 **sids,
1913                            u32 *nel)
1914 {
1915         struct context *fromcon, usercon;
1916         u32 *mysids = NULL, *mysids2, sid;
1917         u32 mynel = 0, maxnel = SIDS_NEL;
1918         struct user_datum *user;
1919         struct role_datum *role;
1920         struct ebitmap_node *rnode, *tnode;
1921         int rc = 0, i, j;
1922
1923         *sids = NULL;
1924         *nel = 0;
1925
1926         if (!ss_initialized)
1927                 goto out;
1928
1929         read_lock(&policy_rwlock);
1930
1931         context_init(&usercon);
1932
1933         fromcon = sidtab_search(&sidtab, fromsid);
1934         if (!fromcon) {
1935                 rc = -EINVAL;
1936                 goto out_unlock;
1937         }
1938
1939         user = hashtab_search(policydb.p_users.table, username);
1940         if (!user) {
1941                 rc = -EINVAL;
1942                 goto out_unlock;
1943         }
1944         usercon.user = user->value;
1945
1946         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1947         if (!mysids) {
1948                 rc = -ENOMEM;
1949                 goto out_unlock;
1950         }
1951
1952         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1953                 role = policydb.role_val_to_struct[i];
1954                 usercon.role = i+1;
1955                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1956                         usercon.type = j+1;
1957
1958                         if (mls_setup_user_range(fromcon, user, &usercon))
1959                                 continue;
1960
1961                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1962                         if (rc)
1963                                 goto out_unlock;
1964                         if (mynel < maxnel) {
1965                                 mysids[mynel++] = sid;
1966                         } else {
1967                                 maxnel += SIDS_NEL;
1968                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1969                                 if (!mysids2) {
1970                                         rc = -ENOMEM;
1971                                         goto out_unlock;
1972                                 }
1973                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1974                                 kfree(mysids);
1975                                 mysids = mysids2;
1976                                 mysids[mynel++] = sid;
1977                         }
1978                 }
1979         }
1980
1981 out_unlock:
1982         read_unlock(&policy_rwlock);
1983         if (rc || !mynel) {
1984                 kfree(mysids);
1985                 goto out;
1986         }
1987
1988         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1989         if (!mysids2) {
1990                 rc = -ENOMEM;
1991                 kfree(mysids);
1992                 goto out;
1993         }
1994         for (i = 0, j = 0; i < mynel; i++) {
1995                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
1996                                           SECCLASS_PROCESS,
1997                                           PROCESS__TRANSITION, AVC_STRICT,
1998                                           NULL);
1999                 if (!rc)
2000                         mysids2[j++] = mysids[i];
2001                 cond_resched();
2002         }
2003         rc = 0;
2004         kfree(mysids);
2005         *sids = mysids2;
2006         *nel = j;
2007 out:
2008         return rc;
2009 }
2010
2011 /**
2012  * security_genfs_sid - Obtain a SID for a file in a filesystem
2013  * @fstype: filesystem type
2014  * @path: path from root of mount
2015  * @sclass: file security class
2016  * @sid: SID for path
2017  *
2018  * Obtain a SID to use for a file in a filesystem that
2019  * cannot support xattr or use a fixed labeling behavior like
2020  * transition SIDs or task SIDs.
2021  */
2022 int security_genfs_sid(const char *fstype,
2023                        char *path,
2024                        u16 sclass,
2025                        u32 *sid)
2026 {
2027         int len;
2028         struct genfs *genfs;
2029         struct ocontext *c;
2030         int rc = 0, cmp = 0;
2031
2032         while (path[0] == '/' && path[1] == '/')
2033                 path++;
2034
2035         read_lock(&policy_rwlock);
2036
2037         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2038                 cmp = strcmp(fstype, genfs->fstype);
2039                 if (cmp <= 0)
2040                         break;
2041         }
2042
2043         if (!genfs || cmp) {
2044                 *sid = SECINITSID_UNLABELED;
2045                 rc = -ENOENT;
2046                 goto out;
2047         }
2048
2049         for (c = genfs->head; c; c = c->next) {
2050                 len = strlen(c->u.name);
2051                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2052                     (strncmp(c->u.name, path, len) == 0))
2053                         break;
2054         }
2055
2056         if (!c) {
2057                 *sid = SECINITSID_UNLABELED;
2058                 rc = -ENOENT;
2059                 goto out;
2060         }
2061
2062         if (!c->sid[0]) {
2063                 rc = sidtab_context_to_sid(&sidtab,
2064                                            &c->context[0],
2065                                            &c->sid[0]);
2066                 if (rc)
2067                         goto out;
2068         }
2069
2070         *sid = c->sid[0];
2071 out:
2072         read_unlock(&policy_rwlock);
2073         return rc;
2074 }
2075
2076 /**
2077  * security_fs_use - Determine how to handle labeling for a filesystem.
2078  * @fstype: filesystem type
2079  * @behavior: labeling behavior
2080  * @sid: SID for filesystem (superblock)
2081  */
2082 int security_fs_use(
2083         const char *fstype,
2084         unsigned int *behavior,
2085         u32 *sid)
2086 {
2087         int rc = 0;
2088         struct ocontext *c;
2089
2090         read_lock(&policy_rwlock);
2091
2092         c = policydb.ocontexts[OCON_FSUSE];
2093         while (c) {
2094                 if (strcmp(fstype, c->u.name) == 0)
2095                         break;
2096                 c = c->next;
2097         }
2098
2099         if (c) {
2100                 *behavior = c->v.behavior;
2101                 if (!c->sid[0]) {
2102                         rc = sidtab_context_to_sid(&sidtab,
2103                                                    &c->context[0],
2104                                                    &c->sid[0]);
2105                         if (rc)
2106                                 goto out;
2107                 }
2108                 *sid = c->sid[0];
2109         } else {
2110                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2111                 if (rc) {
2112                         *behavior = SECURITY_FS_USE_NONE;
2113                         rc = 0;
2114                 } else {
2115                         *behavior = SECURITY_FS_USE_GENFS;
2116                 }
2117         }
2118
2119 out:
2120         read_unlock(&policy_rwlock);
2121         return rc;
2122 }
2123
2124 int security_get_bools(int *len, char ***names, int **values)
2125 {
2126         int i, rc = -ENOMEM;
2127
2128         read_lock(&policy_rwlock);
2129         *names = NULL;
2130         *values = NULL;
2131
2132         *len = policydb.p_bools.nprim;
2133         if (!*len) {
2134                 rc = 0;
2135                 goto out;
2136         }
2137
2138        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2139         if (!*names)
2140                 goto err;
2141
2142        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2143         if (!*values)
2144                 goto err;
2145
2146         for (i = 0; i < *len; i++) {
2147                 size_t name_len;
2148                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2149                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2150                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2151                 if (!(*names)[i])
2152                         goto err;
2153                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2154                 (*names)[i][name_len - 1] = 0;
2155         }
2156         rc = 0;
2157 out:
2158         read_unlock(&policy_rwlock);
2159         return rc;
2160 err:
2161         if (*names) {
2162                 for (i = 0; i < *len; i++)
2163                         kfree((*names)[i]);
2164         }
2165         kfree(*values);
2166         goto out;
2167 }
2168
2169
2170 int security_set_bools(int len, int *values)
2171 {
2172         int i, rc = 0;
2173         int lenp, seqno = 0;
2174         struct cond_node *cur;
2175
2176         write_lock_irq(&policy_rwlock);
2177
2178         lenp = policydb.p_bools.nprim;
2179         if (len != lenp) {
2180                 rc = -EFAULT;
2181                 goto out;
2182         }
2183
2184         for (i = 0; i < len; i++) {
2185                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2186                         audit_log(current->audit_context, GFP_ATOMIC,
2187                                 AUDIT_MAC_CONFIG_CHANGE,
2188                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2189                                 policydb.p_bool_val_to_name[i],
2190                                 !!values[i],
2191                                 policydb.bool_val_to_struct[i]->state,
2192                                 audit_get_loginuid(current),
2193                                 audit_get_sessionid(current));
2194                 }
2195                 if (values[i])
2196                         policydb.bool_val_to_struct[i]->state = 1;
2197                 else
2198                         policydb.bool_val_to_struct[i]->state = 0;
2199         }
2200
2201         for (cur = policydb.cond_list; cur; cur = cur->next) {
2202                 rc = evaluate_cond_node(&policydb, cur);
2203                 if (rc)
2204                         goto out;
2205         }
2206
2207         seqno = ++latest_granting;
2208
2209 out:
2210         write_unlock_irq(&policy_rwlock);
2211         if (!rc) {
2212                 avc_ss_reset(seqno);
2213                 selnl_notify_policyload(seqno);
2214                 selinux_xfrm_notify_policyload();
2215         }
2216         return rc;
2217 }
2218
2219 int security_get_bool_value(int bool)
2220 {
2221         int rc = 0;
2222         int len;
2223
2224         read_lock(&policy_rwlock);
2225
2226         len = policydb.p_bools.nprim;
2227         if (bool >= len) {
2228                 rc = -EFAULT;
2229                 goto out;
2230         }
2231
2232         rc = policydb.bool_val_to_struct[bool]->state;
2233 out:
2234         read_unlock(&policy_rwlock);
2235         return rc;
2236 }
2237
2238 static int security_preserve_bools(struct policydb *p)
2239 {
2240         int rc, nbools = 0, *bvalues = NULL, i;
2241         char **bnames = NULL;
2242         struct cond_bool_datum *booldatum;
2243         struct cond_node *cur;
2244
2245         rc = security_get_bools(&nbools, &bnames, &bvalues);
2246         if (rc)
2247                 goto out;
2248         for (i = 0; i < nbools; i++) {
2249                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2250                 if (booldatum)
2251                         booldatum->state = bvalues[i];
2252         }
2253         for (cur = p->cond_list; cur; cur = cur->next) {
2254                 rc = evaluate_cond_node(p, cur);
2255                 if (rc)
2256                         goto out;
2257         }
2258
2259 out:
2260         if (bnames) {
2261                 for (i = 0; i < nbools; i++)
2262                         kfree(bnames[i]);
2263         }
2264         kfree(bnames);
2265         kfree(bvalues);
2266         return rc;
2267 }
2268
2269 /*
2270  * security_sid_mls_copy() - computes a new sid based on the given
2271  * sid and the mls portion of mls_sid.
2272  */
2273 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2274 {
2275         struct context *context1;
2276         struct context *context2;
2277         struct context newcon;
2278         char *s;
2279         u32 len;
2280         int rc = 0;
2281
2282         if (!ss_initialized || !selinux_mls_enabled) {
2283                 *new_sid = sid;
2284                 goto out;
2285         }
2286
2287         context_init(&newcon);
2288
2289         read_lock(&policy_rwlock);
2290         context1 = sidtab_search(&sidtab, sid);
2291         if (!context1) {
2292                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2293                         __func__, sid);
2294                 rc = -EINVAL;
2295                 goto out_unlock;
2296         }
2297
2298         context2 = sidtab_search(&sidtab, mls_sid);
2299         if (!context2) {
2300                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2301                         __func__, mls_sid);
2302                 rc = -EINVAL;
2303                 goto out_unlock;
2304         }
2305
2306         newcon.user = context1->user;
2307         newcon.role = context1->role;
2308         newcon.type = context1->type;
2309         rc = mls_context_cpy(&newcon, context2);
2310         if (rc)
2311                 goto out_unlock;
2312
2313         /* Check the validity of the new context. */
2314         if (!policydb_context_isvalid(&policydb, &newcon)) {
2315                 rc = convert_context_handle_invalid_context(&newcon);
2316                 if (rc)
2317                         goto bad;
2318         }
2319
2320         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2321         goto out_unlock;
2322
2323 bad:
2324         if (!context_struct_to_string(&newcon, &s, &len)) {
2325                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2326                           "security_sid_mls_copy: invalid context %s", s);
2327                 kfree(s);
2328         }
2329
2330 out_unlock:
2331         read_unlock(&policy_rwlock);
2332         context_destroy(&newcon);
2333 out:
2334         return rc;
2335 }
2336
2337 /**
2338  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2339  * @nlbl_sid: NetLabel SID
2340  * @nlbl_type: NetLabel labeling protocol type
2341  * @xfrm_sid: XFRM SID
2342  *
2343  * Description:
2344  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2345  * resolved into a single SID it is returned via @peer_sid and the function
2346  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2347  * returns a negative value.  A table summarizing the behavior is below:
2348  *
2349  *                                 | function return |      @sid
2350  *   ------------------------------+-----------------+-----------------
2351  *   no peer labels                |        0        |    SECSID_NULL
2352  *   single peer label             |        0        |    <peer_label>
2353  *   multiple, consistent labels   |        0        |    <peer_label>
2354  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2355  *
2356  */
2357 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2358                                  u32 xfrm_sid,
2359                                  u32 *peer_sid)
2360 {
2361         int rc;
2362         struct context *nlbl_ctx;
2363         struct context *xfrm_ctx;
2364
2365         /* handle the common (which also happens to be the set of easy) cases
2366          * right away, these two if statements catch everything involving a
2367          * single or absent peer SID/label */
2368         if (xfrm_sid == SECSID_NULL) {
2369                 *peer_sid = nlbl_sid;
2370                 return 0;
2371         }
2372         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2373          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2374          * is present */
2375         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2376                 *peer_sid = xfrm_sid;
2377                 return 0;
2378         }
2379
2380         /* we don't need to check ss_initialized here since the only way both
2381          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2382          * security server was initialized and ss_initialized was true */
2383         if (!selinux_mls_enabled) {
2384                 *peer_sid = SECSID_NULL;
2385                 return 0;
2386         }
2387
2388         read_lock(&policy_rwlock);
2389
2390         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2391         if (!nlbl_ctx) {
2392                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2393                        __func__, nlbl_sid);
2394                 rc = -EINVAL;
2395                 goto out_slowpath;
2396         }
2397         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2398         if (!xfrm_ctx) {
2399                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2400                        __func__, xfrm_sid);
2401                 rc = -EINVAL;
2402                 goto out_slowpath;
2403         }
2404         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2405
2406 out_slowpath:
2407         read_unlock(&policy_rwlock);
2408         if (rc == 0)
2409                 /* at present NetLabel SIDs/labels really only carry MLS
2410                  * information so if the MLS portion of the NetLabel SID
2411                  * matches the MLS portion of the labeled XFRM SID/label
2412                  * then pass along the XFRM SID as it is the most
2413                  * expressive */
2414                 *peer_sid = xfrm_sid;
2415         else
2416                 *peer_sid = SECSID_NULL;
2417         return rc;
2418 }
2419
2420 static int get_classes_callback(void *k, void *d, void *args)
2421 {
2422         struct class_datum *datum = d;
2423         char *name = k, **classes = args;
2424         int value = datum->value - 1;
2425
2426         classes[value] = kstrdup(name, GFP_ATOMIC);
2427         if (!classes[value])
2428                 return -ENOMEM;
2429
2430         return 0;
2431 }
2432
2433 int security_get_classes(char ***classes, int *nclasses)
2434 {
2435         int rc = -ENOMEM;
2436
2437         read_lock(&policy_rwlock);
2438
2439         *nclasses = policydb.p_classes.nprim;
2440         *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2441         if (!*classes)
2442                 goto out;
2443
2444         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2445                         *classes);
2446         if (rc < 0) {
2447                 int i;
2448                 for (i = 0; i < *nclasses; i++)
2449                         kfree((*classes)[i]);
2450                 kfree(*classes);
2451         }
2452
2453 out:
2454         read_unlock(&policy_rwlock);
2455         return rc;
2456 }
2457
2458 static int get_permissions_callback(void *k, void *d, void *args)
2459 {
2460         struct perm_datum *datum = d;
2461         char *name = k, **perms = args;
2462         int value = datum->value - 1;
2463
2464         perms[value] = kstrdup(name, GFP_ATOMIC);
2465         if (!perms[value])
2466                 return -ENOMEM;
2467
2468         return 0;
2469 }
2470
2471 int security_get_permissions(char *class, char ***perms, int *nperms)
2472 {
2473         int rc = -ENOMEM, i;
2474         struct class_datum *match;
2475
2476         read_lock(&policy_rwlock);
2477
2478         match = hashtab_search(policydb.p_classes.table, class);
2479         if (!match) {
2480                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2481                         __func__, class);
2482                 rc = -EINVAL;
2483                 goto out;
2484         }
2485
2486         *nperms = match->permissions.nprim;
2487         *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2488         if (!*perms)
2489                 goto out;
2490
2491         if (match->comdatum) {
2492                 rc = hashtab_map(match->comdatum->permissions.table,
2493                                 get_permissions_callback, *perms);
2494                 if (rc < 0)
2495                         goto err;
2496         }
2497
2498         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2499                         *perms);
2500         if (rc < 0)
2501                 goto err;
2502
2503 out:
2504         read_unlock(&policy_rwlock);
2505         return rc;
2506
2507 err:
2508         read_unlock(&policy_rwlock);
2509         for (i = 0; i < *nperms; i++)
2510                 kfree((*perms)[i]);
2511         kfree(*perms);
2512         return rc;
2513 }
2514
2515 int security_get_reject_unknown(void)
2516 {
2517         return policydb.reject_unknown;
2518 }
2519
2520 int security_get_allow_unknown(void)
2521 {
2522         return policydb.allow_unknown;
2523 }
2524
2525 /**
2526  * security_policycap_supported - Check for a specific policy capability
2527  * @req_cap: capability
2528  *
2529  * Description:
2530  * This function queries the currently loaded policy to see if it supports the
2531  * capability specified by @req_cap.  Returns true (1) if the capability is
2532  * supported, false (0) if it isn't supported.
2533  *
2534  */
2535 int security_policycap_supported(unsigned int req_cap)
2536 {
2537         int rc;
2538
2539         read_lock(&policy_rwlock);
2540         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2541         read_unlock(&policy_rwlock);
2542
2543         return rc;
2544 }
2545
2546 struct selinux_audit_rule {
2547         u32 au_seqno;
2548         struct context au_ctxt;
2549 };
2550
2551 void selinux_audit_rule_free(void *vrule)
2552 {
2553         struct selinux_audit_rule *rule = vrule;
2554
2555         if (rule) {
2556                 context_destroy(&rule->au_ctxt);
2557                 kfree(rule);
2558         }
2559 }
2560
2561 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2562 {
2563         struct selinux_audit_rule *tmprule;
2564         struct role_datum *roledatum;
2565         struct type_datum *typedatum;
2566         struct user_datum *userdatum;
2567         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2568         int rc = 0;
2569
2570         *rule = NULL;
2571
2572         if (!ss_initialized)
2573                 return -EOPNOTSUPP;
2574
2575         switch (field) {
2576         case AUDIT_SUBJ_USER:
2577         case AUDIT_SUBJ_ROLE:
2578         case AUDIT_SUBJ_TYPE:
2579         case AUDIT_OBJ_USER:
2580         case AUDIT_OBJ_ROLE:
2581         case AUDIT_OBJ_TYPE:
2582                 /* only 'equals' and 'not equals' fit user, role, and type */
2583                 if (op != Audit_equal && op != Audit_not_equal)
2584                         return -EINVAL;
2585                 break;
2586         case AUDIT_SUBJ_SEN:
2587         case AUDIT_SUBJ_CLR:
2588         case AUDIT_OBJ_LEV_LOW:
2589         case AUDIT_OBJ_LEV_HIGH:
2590                 /* we do not allow a range, indicated by the presense of '-' */
2591                 if (strchr(rulestr, '-'))
2592                         return -EINVAL;
2593                 break;
2594         default:
2595                 /* only the above fields are valid */
2596                 return -EINVAL;
2597         }
2598
2599         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2600         if (!tmprule)
2601                 return -ENOMEM;
2602
2603         context_init(&tmprule->au_ctxt);
2604
2605         read_lock(&policy_rwlock);
2606
2607         tmprule->au_seqno = latest_granting;
2608
2609         switch (field) {
2610         case AUDIT_SUBJ_USER:
2611         case AUDIT_OBJ_USER:
2612                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2613                 if (!userdatum)
2614                         rc = -EINVAL;
2615                 else
2616                         tmprule->au_ctxt.user = userdatum->value;
2617                 break;
2618         case AUDIT_SUBJ_ROLE:
2619         case AUDIT_OBJ_ROLE:
2620                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2621                 if (!roledatum)
2622                         rc = -EINVAL;
2623                 else
2624                         tmprule->au_ctxt.role = roledatum->value;
2625                 break;
2626         case AUDIT_SUBJ_TYPE:
2627         case AUDIT_OBJ_TYPE:
2628                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2629                 if (!typedatum)
2630                         rc = -EINVAL;
2631                 else
2632                         tmprule->au_ctxt.type = typedatum->value;
2633                 break;
2634         case AUDIT_SUBJ_SEN:
2635         case AUDIT_SUBJ_CLR:
2636         case AUDIT_OBJ_LEV_LOW:
2637         case AUDIT_OBJ_LEV_HIGH:
2638                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2639                 break;
2640         }
2641
2642         read_unlock(&policy_rwlock);
2643
2644         if (rc) {
2645                 selinux_audit_rule_free(tmprule);
2646                 tmprule = NULL;
2647         }
2648
2649         *rule = tmprule;
2650
2651         return rc;
2652 }
2653
2654 /* Check to see if the rule contains any selinux fields */
2655 int selinux_audit_rule_known(struct audit_krule *rule)
2656 {
2657         int i;
2658
2659         for (i = 0; i < rule->field_count; i++) {
2660                 struct audit_field *f = &rule->fields[i];
2661                 switch (f->type) {
2662                 case AUDIT_SUBJ_USER:
2663                 case AUDIT_SUBJ_ROLE:
2664                 case AUDIT_SUBJ_TYPE:
2665                 case AUDIT_SUBJ_SEN:
2666                 case AUDIT_SUBJ_CLR:
2667                 case AUDIT_OBJ_USER:
2668                 case AUDIT_OBJ_ROLE:
2669                 case AUDIT_OBJ_TYPE:
2670                 case AUDIT_OBJ_LEV_LOW:
2671                 case AUDIT_OBJ_LEV_HIGH:
2672                         return 1;
2673                 }
2674         }
2675
2676         return 0;
2677 }
2678
2679 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2680                              struct audit_context *actx)
2681 {
2682         struct context *ctxt;
2683         struct mls_level *level;
2684         struct selinux_audit_rule *rule = vrule;
2685         int match = 0;
2686
2687         if (!rule) {
2688                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2689                           "selinux_audit_rule_match: missing rule\n");
2690                 return -ENOENT;
2691         }
2692
2693         read_lock(&policy_rwlock);
2694
2695         if (rule->au_seqno < latest_granting) {
2696                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2697                           "selinux_audit_rule_match: stale rule\n");
2698                 match = -ESTALE;
2699                 goto out;
2700         }
2701
2702         ctxt = sidtab_search(&sidtab, sid);
2703         if (!ctxt) {
2704                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2705                           "selinux_audit_rule_match: unrecognized SID %d\n",
2706                           sid);
2707                 match = -ENOENT;
2708                 goto out;
2709         }
2710
2711         /* a field/op pair that is not caught here will simply fall through
2712            without a match */
2713         switch (field) {
2714         case AUDIT_SUBJ_USER:
2715         case AUDIT_OBJ_USER:
2716                 switch (op) {
2717                 case Audit_equal:
2718                         match = (ctxt->user == rule->au_ctxt.user);
2719                         break;
2720                 case Audit_not_equal:
2721                         match = (ctxt->user != rule->au_ctxt.user);
2722                         break;
2723                 }
2724                 break;
2725         case AUDIT_SUBJ_ROLE:
2726         case AUDIT_OBJ_ROLE:
2727                 switch (op) {
2728                 case Audit_equal:
2729                         match = (ctxt->role == rule->au_ctxt.role);
2730                         break;
2731                 case Audit_not_equal:
2732                         match = (ctxt->role != rule->au_ctxt.role);
2733                         break;
2734                 }
2735                 break;
2736         case AUDIT_SUBJ_TYPE:
2737         case AUDIT_OBJ_TYPE:
2738                 switch (op) {
2739                 case Audit_equal:
2740                         match = (ctxt->type == rule->au_ctxt.type);
2741                         break;
2742                 case Audit_not_equal:
2743                         match = (ctxt->type != rule->au_ctxt.type);
2744                         break;
2745                 }
2746                 break;
2747         case AUDIT_SUBJ_SEN:
2748         case AUDIT_SUBJ_CLR:
2749         case AUDIT_OBJ_LEV_LOW:
2750         case AUDIT_OBJ_LEV_HIGH:
2751                 level = ((field == AUDIT_SUBJ_SEN ||
2752                           field == AUDIT_OBJ_LEV_LOW) ?
2753                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2754                 switch (op) {
2755                 case Audit_equal:
2756                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2757                                              level);
2758                         break;
2759                 case Audit_not_equal:
2760                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2761                                               level);
2762                         break;
2763                 case Audit_lt:
2764                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2765                                                level) &&
2766                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2767                                                level));
2768                         break;
2769                 case Audit_le:
2770                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2771                                               level);
2772                         break;
2773                 case Audit_gt:
2774                         match = (mls_level_dom(level,
2775                                               &rule->au_ctxt.range.level[0]) &&
2776                                  !mls_level_eq(level,
2777                                                &rule->au_ctxt.range.level[0]));
2778                         break;
2779                 case Audit_ge:
2780                         match = mls_level_dom(level,
2781                                               &rule->au_ctxt.range.level[0]);
2782                         break;
2783                 }
2784         }
2785
2786 out:
2787         read_unlock(&policy_rwlock);
2788         return match;
2789 }
2790
2791 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2792
2793 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2794                                u16 class, u32 perms, u32 *retained)
2795 {
2796         int err = 0;
2797
2798         if (event == AVC_CALLBACK_RESET && aurule_callback)
2799                 err = aurule_callback();
2800         return err;
2801 }
2802
2803 static int __init aurule_init(void)
2804 {
2805         int err;
2806
2807         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2808                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2809         if (err)
2810                 panic("avc_add_callback() failed, error %d\n", err);
2811
2812         return err;
2813 }
2814 __initcall(aurule_init);
2815
2816 #ifdef CONFIG_NETLABEL
2817 /**
2818  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2819  * @secattr: the NetLabel packet security attributes
2820  * @sid: the SELinux SID
2821  *
2822  * Description:
2823  * Attempt to cache the context in @ctx, which was derived from the packet in
2824  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2825  * already been initialized.
2826  *
2827  */
2828 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2829                                       u32 sid)
2830 {
2831         u32 *sid_cache;
2832
2833         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2834         if (sid_cache == NULL)
2835                 return;
2836         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2837         if (secattr->cache == NULL) {
2838                 kfree(sid_cache);
2839                 return;
2840         }
2841
2842         *sid_cache = sid;
2843         secattr->cache->free = kfree;
2844         secattr->cache->data = sid_cache;
2845         secattr->flags |= NETLBL_SECATTR_CACHE;
2846 }
2847
2848 /**
2849  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2850  * @secattr: the NetLabel packet security attributes
2851  * @sid: the SELinux SID
2852  *
2853  * Description:
2854  * Convert the given NetLabel security attributes in @secattr into a
2855  * SELinux SID.  If the @secattr field does not contain a full SELinux
2856  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2857  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2858  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2859  * conversion for future lookups.  Returns zero on success, negative values on
2860  * failure.
2861  *
2862  */
2863 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2864                                    u32 *sid)
2865 {
2866         int rc = -EIDRM;
2867         struct context *ctx;
2868         struct context ctx_new;
2869
2870         if (!ss_initialized) {
2871                 *sid = SECSID_NULL;
2872                 return 0;
2873         }
2874
2875         read_lock(&policy_rwlock);
2876
2877         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2878                 *sid = *(u32 *)secattr->cache->data;
2879                 rc = 0;
2880         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2881                 *sid = secattr->attr.secid;
2882                 rc = 0;
2883         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2884                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2885                 if (ctx == NULL)
2886                         goto netlbl_secattr_to_sid_return;
2887
2888                 context_init(&ctx_new);
2889                 ctx_new.user = ctx->user;
2890                 ctx_new.role = ctx->role;
2891                 ctx_new.type = ctx->type;
2892                 mls_import_netlbl_lvl(&ctx_new, secattr);
2893                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2894                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2895                                                   secattr->attr.mls.cat) != 0)
2896                                 goto netlbl_secattr_to_sid_return;
2897                         memcpy(&ctx_new.range.level[1].cat,
2898                                &ctx_new.range.level[0].cat,
2899                                sizeof(ctx_new.range.level[0].cat));
2900                 }
2901                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2902                         goto netlbl_secattr_to_sid_return_cleanup;
2903
2904                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2905                 if (rc != 0)
2906                         goto netlbl_secattr_to_sid_return_cleanup;
2907
2908                 security_netlbl_cache_add(secattr, *sid);
2909
2910                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2911         } else {
2912                 *sid = SECSID_NULL;
2913                 rc = 0;
2914         }
2915
2916 netlbl_secattr_to_sid_return:
2917         read_unlock(&policy_rwlock);
2918         return rc;
2919 netlbl_secattr_to_sid_return_cleanup:
2920         ebitmap_destroy(&ctx_new.range.level[0].cat);
2921         goto netlbl_secattr_to_sid_return;
2922 }
2923
2924 /**
2925  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2926  * @sid: the SELinux SID
2927  * @secattr: the NetLabel packet security attributes
2928  *
2929  * Description:
2930  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2931  * Returns zero on success, negative values on failure.
2932  *
2933  */
2934 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2935 {
2936         int rc;
2937         struct context *ctx;
2938
2939         if (!ss_initialized)
2940                 return 0;
2941
2942         read_lock(&policy_rwlock);
2943         ctx = sidtab_search(&sidtab, sid);
2944         if (ctx == NULL) {
2945                 rc = -ENOENT;
2946                 goto netlbl_sid_to_secattr_failure;
2947         }
2948         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2949                                   GFP_ATOMIC);
2950         if (secattr->domain == NULL) {
2951                 rc = -ENOMEM;
2952                 goto netlbl_sid_to_secattr_failure;
2953         }
2954         secattr->attr.secid = sid;
2955         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
2956         mls_export_netlbl_lvl(ctx, secattr);
2957         rc = mls_export_netlbl_cat(ctx, secattr);
2958         if (rc != 0)
2959                 goto netlbl_sid_to_secattr_failure;
2960         read_unlock(&policy_rwlock);
2961
2962         return 0;
2963
2964 netlbl_sid_to_secattr_failure:
2965         read_unlock(&policy_rwlock);
2966         return rc;
2967 }
2968 #endif /* CONFIG_NETLABEL */