security/selinux/ss/services.c

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