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