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;
  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;
  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 "SELinux: %s:  unrecognized class %d\n", __func__,
 419                 tclass);
 420         return -EINVAL;
 421 }
 422
 423 /*
 424  * Given a sid find if the type has the permissive flag set
 425  */
 426 int security_permissive_sid(u32 sid)
 427 {
 428         struct context *context;
 429         u32 type;
 430         int rc;
 431
 432         POLICY_RDLOCK;
 433
 434         context = sidtab_search(&sidtab, sid);
 435         BUG_ON(!context);
 436
 437         type = context->type;
 438         /*
 439          * we are intentionally using type here, not type-1, the 0th bit may
 440          * someday indicate that we are globally setting permissive in policy.
 441          */
 442         rc = ebitmap_get_bit(&policydb.permissive_map, type);
 443
 444         POLICY_RDUNLOCK;
 445         return rc;
 446 }
 447
 448 static int security_validtrans_handle_fail(struct context *ocontext,
 449                                            struct context *ncontext,
 450                                            struct context *tcontext,
 451                                            u16 tclass)
 452 {
 453         char *o = NULL, *n = NULL, *t = NULL;
 454         u32 olen, nlen, tlen;
 455
 456         if (context_struct_to_string(ocontext, &o, &olen) < 0)
 457                 goto out;
 458         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
 459                 goto out;
 460         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 461                 goto out;
 462         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 463                   "security_validate_transition:  denied for"
 464                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 465                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
 466 out:
 467         kfree(o);
 468         kfree(n);
 469         kfree(t);
 470
 471         if (!selinux_enforcing)
 472                 return 0;
 473         return -EPERM;
 474 }
 475
 476 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 477                                  u16 tclass)
 478 {
 479         struct context *ocontext;
 480         struct context *ncontext;
 481         struct context *tcontext;
 482         struct class_datum *tclass_datum;
 483         struct constraint_node *constraint;
 484         int rc = 0;
 485
 486         if (!ss_initialized)
 487                 return 0;
 488
 489         POLICY_RDLOCK;
 490
 491         /*
 492          * Remap extended Netlink classes for old policy versions.
 493          * Do this here rather than socket_type_to_security_class()
 494          * in case a newer policy version is loaded, allowing sockets
 495          * to remain in the correct class.
 496          */
 497         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 498                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 499                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 500                         tclass = SECCLASS_NETLINK_SOCKET;
 501
 502         if (!tclass || tclass > policydb.p_classes.nprim) {
 503                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 504                         __func__, tclass);
 505                 rc = -EINVAL;
 506                 goto out;
 507         }
 508         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 509
 510         ocontext = sidtab_search(&sidtab, oldsid);
 511         if (!ocontext) {
 512                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 513                         __func__, oldsid);
 514                 rc = -EINVAL;
 515                 goto out;
 516         }
 517
 518         ncontext = sidtab_search(&sidtab, newsid);
 519         if (!ncontext) {
 520                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 521                         __func__, newsid);
 522                 rc = -EINVAL;
 523                 goto out;
 524         }
 525
 526         tcontext = sidtab_search(&sidtab, tasksid);
 527         if (!tcontext) {
 528                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 529                         __func__, tasksid);
 530                 rc = -EINVAL;
 531                 goto out;
 532         }
 533
 534         constraint = tclass_datum->validatetrans;
 535         while (constraint) {
 536                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 537                                           constraint->expr)) {
 538                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 539                                                              tcontext, tclass);
 540                         goto out;
 541                 }
 542                 constraint = constraint->next;
 543         }
 544
 545 out:
 546         POLICY_RDUNLOCK;
 547         return rc;
 548 }
 549
 550 /**
 551  * security_compute_av - Compute access vector decisions.
 552  * @ssid: source security identifier
 553  * @tsid: target security identifier
 554  * @tclass: target security class
 555  * @requested: requested permissions
 556  * @avd: access vector decisions
 557  *
 558  * Compute a set of access vector decisions based on the
 559  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 560  * Return -%EINVAL if any of the parameters are invalid or %0
 561  * if the access vector decisions were computed successfully.
 562  */
 563 int security_compute_av(u32 ssid,
 564                         u32 tsid,
 565                         u16 tclass,
 566                         u32 requested,
 567                         struct av_decision *avd)
 568 {
 569         struct context *scontext = NULL, *tcontext = NULL;
 570         int rc = 0;
 571
 572         if (!ss_initialized) {
 573                 avd->allowed = 0xffffffff;
 574                 avd->decided = 0xffffffff;
 575                 avd->auditallow = 0;
 576                 avd->auditdeny = 0xffffffff;
 577                 avd->seqno = latest_granting;
 578                 return 0;
 579         }
 580
 581         POLICY_RDLOCK;
 582
 583         scontext = sidtab_search(&sidtab, ssid);
 584         if (!scontext) {
 585                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 586                        __func__, ssid);
 587                 rc = -EINVAL;
 588                 goto out;
 589         }
 590         tcontext = sidtab_search(&sidtab, tsid);
 591         if (!tcontext) {
 592                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 593                        __func__, tsid);
 594                 rc = -EINVAL;
 595                 goto out;
 596         }
 597
 598         rc = context_struct_compute_av(scontext, tcontext, tclass,
 599                                        requested, avd);
 600 out:
 601         POLICY_RDUNLOCK;
 602         return rc;
 603 }
 604
 605 /*
 606  * Write the security context string representation of
 607  * the context structure `context' into a dynamically
 608  * allocated string of the correct size.  Set `*scontext'
 609  * to point to this string and set `*scontext_len' to
 610  * the length of the string.
 611  */
 612 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
 613 {
 614         char *scontextp;
 615
 616         *scontext = NULL;
 617         *scontext_len = 0;
 618
 619         /* Compute the size of the context. */
 620         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
 621         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
 622         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
 623         *scontext_len += mls_compute_context_len(context);
 624
 625         /* Allocate space for the context; caller must free this space. */
 626         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
 627         if (!scontextp)
 628                 return -ENOMEM;
 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 "SELinux: %s:  called before initial "
 691                        "load_policy on unknown SID %d\n", __func__, sid);
 692                 rc = -EINVAL;
 693                 goto out;
 694         }
 695         POLICY_RDLOCK;
 696         context = sidtab_search(&sidtab, sid);
 697         if (!context) {
 698                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 699                         __func__, 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(const 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(const 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(const char *scontext, u32 scontext_len,
 862                                     u32 *sid, 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 "SELinux: %s:  unrecognized SID %d\n",
 930                        __func__, ssid);
 931                 rc = -EINVAL;
 932                 goto out_unlock;
 933         }
 934         tcontext = sidtab_search(&sidtab, tsid);
 935         if (!tcontext) {
 936                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 937                        __func__, 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         c->user = usrdatum->value;
1295
1296         /* Convert the role. */
1297         role = hashtab_search(args->newp->p_roles.table,
1298                               args->oldp->p_role_val_to_name[c->role - 1]);
1299         if (!role)
1300                 goto bad;
1301         c->role = role->value;
1302
1303         /* Convert the type. */
1304         typdatum = hashtab_search(args->newp->p_types.table,
1305                                   args->oldp->p_type_val_to_name[c->type - 1]);
1306         if (!typdatum)
1307                 goto bad;
1308         c->type = typdatum->value;
1309
1310         rc = mls_convert_context(args->oldp, args->newp, c);
1311         if (rc)
1312                 goto bad;
1313
1314         /* Check the validity of the new context. */
1315         if (!policydb_context_isvalid(args->newp, c)) {
1316                 rc = convert_context_handle_invalid_context(&oldc);
1317                 if (rc)
1318                         goto bad;
1319         }
1320
1321         context_destroy(&oldc);
1322 out:
1323         return rc;
1324 bad:
1325         context_struct_to_string(&oldc, &s, &len);
1326         context_destroy(&oldc);
1327         printk(KERN_ERR "SELinux:  invalidating context %s\n", s);
1328         kfree(s);
1329         goto out;
1330 }
1331
1332 static void security_load_policycaps(void)
1333 {
1334         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1335                                                   POLICYDB_CAPABILITY_NETPEER);
1336         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1337                                                   POLICYDB_CAPABILITY_OPENPERM);
1338 }
1339
1340 extern void selinux_complete_init(void);
1341 static int security_preserve_bools(struct policydb *p);
1342
1343 /**
1344  * security_load_policy - Load a security policy configuration.
1345  * @data: binary policy data
1346  * @len: length of data in bytes
1347  *
1348  * Load a new set of security policy configuration data,
1349  * validate it and convert the SID table as necessary.
1350  * This function will flush the access vector cache after
1351  * loading the new policy.
1352  */
1353 int security_load_policy(void *data, size_t len)
1354 {
1355         struct policydb oldpolicydb, newpolicydb;
1356         struct sidtab oldsidtab, newsidtab;
1357         struct convert_context_args args;
1358         u32 seqno;
1359         int rc = 0;
1360         struct policy_file file = { data, len }, *fp = &file;
1361
1362         LOAD_LOCK;
1363
1364         if (!ss_initialized) {
1365                 avtab_cache_init();
1366                 if (policydb_read(&policydb, fp)) {
1367                         LOAD_UNLOCK;
1368                         avtab_cache_destroy();
1369                         return -EINVAL;
1370                 }
1371                 if (policydb_load_isids(&policydb, &sidtab)) {
1372                         LOAD_UNLOCK;
1373                         policydb_destroy(&policydb);
1374                         avtab_cache_destroy();
1375                         return -EINVAL;
1376                 }
1377                 /* Verify that the kernel defined classes are correct. */
1378                 if (validate_classes(&policydb)) {
1379                         printk(KERN_ERR
1380                                "SELinux:  the definition of a class is incorrect\n");
1381                         LOAD_UNLOCK;
1382                         sidtab_destroy(&sidtab);
1383                         policydb_destroy(&policydb);
1384                         avtab_cache_destroy();
1385                         return -EINVAL;
1386                 }
1387                 security_load_policycaps();
1388                 policydb_loaded_version = policydb.policyvers;
1389                 ss_initialized = 1;
1390                 seqno = ++latest_granting;
1391                 LOAD_UNLOCK;
1392                 selinux_complete_init();
1393                 avc_ss_reset(seqno);
1394                 selnl_notify_policyload(seqno);
1395                 selinux_netlbl_cache_invalidate();
1396                 selinux_xfrm_notify_policyload();
1397                 return 0;
1398         }
1399
1400 #if 0
1401         sidtab_hash_eval(&sidtab, "sids");
1402 #endif
1403
1404         if (policydb_read(&newpolicydb, fp)) {
1405                 LOAD_UNLOCK;
1406                 return -EINVAL;
1407         }
1408
1409         sidtab_init(&newsidtab);
1410
1411         /* Verify that the kernel defined classes are correct. */
1412         if (validate_classes(&newpolicydb)) {
1413                 printk(KERN_ERR
1414                        "SELinux:  the definition of a class is incorrect\n");
1415                 rc = -EINVAL;
1416                 goto err;
1417         }
1418
1419         rc = security_preserve_bools(&newpolicydb);
1420         if (rc) {
1421                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1422                 goto err;
1423         }
1424
1425         /* Clone the SID table. */
1426         sidtab_shutdown(&sidtab);
1427         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1428                 rc = -ENOMEM;
1429                 goto err;
1430         }
1431
1432         /* Convert the internal representations of contexts
1433            in the new SID table and remove invalid SIDs. */
1434         args.oldp = &policydb;
1435         args.newp = &newpolicydb;
1436         sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1437
1438         /* Save the old policydb and SID table to free later. */
1439         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1440         sidtab_set(&oldsidtab, &sidtab);
1441
1442         /* Install the new policydb and SID table. */
1443         POLICY_WRLOCK;
1444         memcpy(&policydb, &newpolicydb, sizeof policydb);
1445         sidtab_set(&sidtab, &newsidtab);
1446         security_load_policycaps();
1447         seqno = ++latest_granting;
1448         policydb_loaded_version = policydb.policyvers;
1449         POLICY_WRUNLOCK;
1450         LOAD_UNLOCK;
1451
1452         /* Free the old policydb and SID table. */
1453         policydb_destroy(&oldpolicydb);
1454         sidtab_destroy(&oldsidtab);
1455
1456         avc_ss_reset(seqno);
1457         selnl_notify_policyload(seqno);
1458         selinux_netlbl_cache_invalidate();
1459         selinux_xfrm_notify_policyload();
1460
1461         return 0;
1462
1463 err:
1464         LOAD_UNLOCK;
1465         sidtab_destroy(&newsidtab);
1466         policydb_destroy(&newpolicydb);
1467         return rc;
1468
1469 }
1470
1471 /**
1472  * security_port_sid - Obtain the SID for a port.
1473  * @protocol: protocol number
1474  * @port: port number
1475  * @out_sid: security identifier
1476  */
1477 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1478 {
1479         struct ocontext *c;
1480         int rc = 0;
1481
1482         POLICY_RDLOCK;
1483
1484         c = policydb.ocontexts[OCON_PORT];
1485         while (c) {
1486                 if (c->u.port.protocol == protocol &&
1487                     c->u.port.low_port <= port &&
1488                     c->u.port.high_port >= port)
1489                         break;
1490                 c = c->next;
1491         }
1492
1493         if (c) {
1494                 if (!c->sid[0]) {
1495                         rc = sidtab_context_to_sid(&sidtab,
1496                                                    &c->context[0],
1497                                                    &c->sid[0]);
1498                         if (rc)
1499                                 goto out;
1500                 }
1501                 *out_sid = c->sid[0];
1502         } else {
1503                 *out_sid = SECINITSID_PORT;
1504         }
1505
1506 out:
1507         POLICY_RDUNLOCK;
1508         return rc;
1509 }
1510
1511 /**
1512  * security_netif_sid - Obtain the SID for a network interface.
1513  * @name: interface name
1514  * @if_sid: interface SID
1515  */
1516 int security_netif_sid(char *name, u32 *if_sid)
1517 {
1518         int rc = 0;
1519         struct ocontext *c;
1520
1521         POLICY_RDLOCK;
1522
1523         c = policydb.ocontexts[OCON_NETIF];
1524         while (c) {
1525                 if (strcmp(name, c->u.name) == 0)
1526                         break;
1527                 c = c->next;
1528         }
1529
1530         if (c) {
1531                 if (!c->sid[0] || !c->sid[1]) {
1532                         rc = sidtab_context_to_sid(&sidtab,
1533                                                   &c->context[0],
1534                                                   &c->sid[0]);
1535                         if (rc)
1536                                 goto out;
1537                         rc = sidtab_context_to_sid(&sidtab,
1538                                                    &c->context[1],
1539                                                    &c->sid[1]);
1540                         if (rc)
1541                                 goto out;
1542                 }
1543                 *if_sid = c->sid[0];
1544         } else
1545                 *if_sid = SECINITSID_NETIF;
1546
1547 out:
1548         POLICY_RDUNLOCK;
1549         return rc;
1550 }
1551
1552 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1553 {
1554         int i, fail = 0;
1555
1556         for (i = 0; i < 4; i++)
1557                 if (addr[i] != (input[i] & mask[i])) {
1558                         fail = 1;
1559                         break;
1560                 }
1561
1562         return !fail;
1563 }
1564
1565 /**
1566  * security_node_sid - Obtain the SID for a node (host).
1567  * @domain: communication domain aka address family
1568  * @addrp: address
1569  * @addrlen: address length in bytes
1570  * @out_sid: security identifier
1571  */
1572 int security_node_sid(u16 domain,
1573                       void *addrp,
1574                       u32 addrlen,
1575                       u32 *out_sid)
1576 {
1577         int rc = 0;
1578         struct ocontext *c;
1579
1580         POLICY_RDLOCK;
1581
1582         switch (domain) {
1583         case AF_INET: {
1584                 u32 addr;
1585
1586                 if (addrlen != sizeof(u32)) {
1587                         rc = -EINVAL;
1588                         goto out;
1589                 }
1590
1591                 addr = *((u32 *)addrp);
1592
1593                 c = policydb.ocontexts[OCON_NODE];
1594                 while (c) {
1595                         if (c->u.node.addr == (addr & c->u.node.mask))
1596                                 break;
1597                         c = c->next;
1598                 }
1599                 break;
1600         }
1601
1602         case AF_INET6:
1603                 if (addrlen != sizeof(u64) * 2) {
1604                         rc = -EINVAL;
1605                         goto out;
1606                 }
1607                 c = policydb.ocontexts[OCON_NODE6];
1608                 while (c) {
1609                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1610                                                 c->u.node6.mask))
1611                                 break;
1612                         c = c->next;
1613                 }
1614                 break;
1615
1616         default:
1617                 *out_sid = SECINITSID_NODE;
1618                 goto out;
1619         }
1620
1621         if (c) {
1622                 if (!c->sid[0]) {
1623                         rc = sidtab_context_to_sid(&sidtab,
1624                                                    &c->context[0],
1625                                                    &c->sid[0]);
1626                         if (rc)
1627                                 goto out;
1628                 }
1629                 *out_sid = c->sid[0];
1630         } else {
1631                 *out_sid = SECINITSID_NODE;
1632         }
1633
1634 out:
1635         POLICY_RDUNLOCK;
1636         return rc;
1637 }
1638
1639 #define SIDS_NEL 25
1640
1641 /**
1642  * security_get_user_sids - Obtain reachable SIDs for a user.
1643  * @fromsid: starting SID
1644  * @username: username
1645  * @sids: array of reachable SIDs for user
1646  * @nel: number of elements in @sids
1647  *
1648  * Generate the set of SIDs for legal security contexts
1649  * for a given user that can be reached by @fromsid.
1650  * Set *@sids to point to a dynamically allocated
1651  * array containing the set of SIDs.  Set *@nel to the
1652  * number of elements in the array.
1653  */
1654
1655 int security_get_user_sids(u32 fromsid,
1656                            char *username,
1657                            u32 **sids,
1658                            u32 *nel)
1659 {
1660         struct context *fromcon, usercon;
1661         u32 *mysids = NULL, *mysids2, sid;
1662         u32 mynel = 0, maxnel = SIDS_NEL;
1663         struct user_datum *user;
1664         struct role_datum *role;
1665         struct ebitmap_node *rnode, *tnode;
1666         int rc = 0, i, j;
1667
1668         *sids = NULL;
1669         *nel = 0;
1670
1671         if (!ss_initialized)
1672                 goto out;
1673
1674         POLICY_RDLOCK;
1675
1676         fromcon = sidtab_search(&sidtab, fromsid);
1677         if (!fromcon) {
1678                 rc = -EINVAL;
1679                 goto out_unlock;
1680         }
1681
1682         user = hashtab_search(policydb.p_users.table, username);
1683         if (!user) {
1684                 rc = -EINVAL;
1685                 goto out_unlock;
1686         }
1687         usercon.user = user->value;
1688
1689         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1690         if (!mysids) {
1691                 rc = -ENOMEM;
1692                 goto out_unlock;
1693         }
1694
1695         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1696                 role = policydb.role_val_to_struct[i];
1697                 usercon.role = i+1;
1698                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1699                         usercon.type = j+1;
1700
1701                         if (mls_setup_user_range(fromcon, user, &usercon))
1702                                 continue;
1703
1704                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1705                         if (rc)
1706                                 goto out_unlock;
1707                         if (mynel < maxnel) {
1708                                 mysids[mynel++] = sid;
1709                         } else {
1710                                 maxnel += SIDS_NEL;
1711                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1712                                 if (!mysids2) {
1713                                         rc = -ENOMEM;
1714                                         goto out_unlock;
1715                                 }
1716                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1717                                 kfree(mysids);
1718                                 mysids = mysids2;
1719                                 mysids[mynel++] = sid;
1720                         }
1721                 }
1722         }
1723
1724 out_unlock:
1725         POLICY_RDUNLOCK;
1726         if (rc || !mynel) {
1727                 kfree(mysids);
1728                 goto out;
1729         }
1730
1731         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1732         if (!mysids2) {
1733                 rc = -ENOMEM;
1734                 kfree(mysids);
1735                 goto out;
1736         }
1737         for (i = 0, j = 0; i < mynel; i++) {
1738                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
1739                                           SECCLASS_PROCESS,
1740                                           PROCESS__TRANSITION, AVC_STRICT,
1741                                           NULL);
1742                 if (!rc)
1743                         mysids2[j++] = mysids[i];
1744                 cond_resched();
1745         }
1746         rc = 0;
1747         kfree(mysids);
1748         *sids = mysids2;
1749         *nel = j;
1750 out:
1751         return rc;
1752 }
1753
1754 /**
1755  * security_genfs_sid - Obtain a SID for a file in a filesystem
1756  * @fstype: filesystem type
1757  * @path: path from root of mount
1758  * @sclass: file security class
1759  * @sid: SID for path
1760  *
1761  * Obtain a SID to use for a file in a filesystem that
1762  * cannot support xattr or use a fixed labeling behavior like
1763  * transition SIDs or task SIDs.
1764  */
1765 int security_genfs_sid(const char *fstype,
1766                        char *path,
1767                        u16 sclass,
1768                        u32 *sid)
1769 {
1770         int len;
1771         struct genfs *genfs;
1772         struct ocontext *c;
1773         int rc = 0, cmp = 0;
1774
1775         while (path[0] == '/' && path[1] == '/')
1776                 path++;
1777
1778         POLICY_RDLOCK;
1779
1780         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1781                 cmp = strcmp(fstype, genfs->fstype);
1782                 if (cmp <= 0)
1783                         break;
1784         }
1785
1786         if (!genfs || cmp) {
1787                 *sid = SECINITSID_UNLABELED;
1788                 rc = -ENOENT;
1789                 goto out;
1790         }
1791
1792         for (c = genfs->head; c; c = c->next) {
1793                 len = strlen(c->u.name);
1794                 if ((!c->v.sclass || sclass == c->v.sclass) &&
1795                     (strncmp(c->u.name, path, len) == 0))
1796                         break;
1797         }
1798
1799         if (!c) {
1800                 *sid = SECINITSID_UNLABELED;
1801                 rc = -ENOENT;
1802                 goto out;
1803         }
1804
1805         if (!c->sid[0]) {
1806                 rc = sidtab_context_to_sid(&sidtab,
1807                                            &c->context[0],
1808                                            &c->sid[0]);
1809                 if (rc)
1810                         goto out;
1811         }
1812
1813         *sid = c->sid[0];
1814 out:
1815         POLICY_RDUNLOCK;
1816         return rc;
1817 }
1818
1819 /**
1820  * security_fs_use - Determine how to handle labeling for a filesystem.
1821  * @fstype: filesystem type
1822  * @behavior: labeling behavior
1823  * @sid: SID for filesystem (superblock)
1824  */
1825 int security_fs_use(
1826         const char *fstype,
1827         unsigned int *behavior,
1828         u32 *sid)
1829 {
1830         int rc = 0;
1831         struct ocontext *c;
1832
1833         POLICY_RDLOCK;
1834
1835         c = policydb.ocontexts[OCON_FSUSE];
1836         while (c) {
1837                 if (strcmp(fstype, c->u.name) == 0)
1838                         break;
1839                 c = c->next;
1840         }
1841
1842         if (c) {
1843                 *behavior = c->v.behavior;
1844                 if (!c->sid[0]) {
1845                         rc = sidtab_context_to_sid(&sidtab,
1846                                                    &c->context[0],
1847                                                    &c->sid[0]);
1848                         if (rc)
1849                                 goto out;
1850                 }
1851                 *sid = c->sid[0];
1852         } else {
1853                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1854                 if (rc) {
1855                         *behavior = SECURITY_FS_USE_NONE;
1856                         rc = 0;
1857                 } else {
1858                         *behavior = SECURITY_FS_USE_GENFS;
1859                 }
1860         }
1861
1862 out:
1863         POLICY_RDUNLOCK;
1864         return rc;
1865 }
1866
1867 int security_get_bools(int *len, char ***names, int **values)
1868 {
1869         int i, rc = -ENOMEM;
1870
1871         POLICY_RDLOCK;
1872         *names = NULL;
1873         *values = NULL;
1874
1875         *len = policydb.p_bools.nprim;
1876         if (!*len) {
1877                 rc = 0;
1878                 goto out;
1879         }
1880
1881        *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
1882         if (!*names)
1883                 goto err;
1884
1885        *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1886         if (!*values)
1887                 goto err;
1888
1889         for (i = 0; i < *len; i++) {
1890                 size_t name_len;
1891                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1892                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1893                (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1894                 if (!(*names)[i])
1895                         goto err;
1896                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1897                 (*names)[i][name_len - 1] = 0;
1898         }
1899         rc = 0;
1900 out:
1901         POLICY_RDUNLOCK;
1902         return rc;
1903 err:
1904         if (*names) {
1905                 for (i = 0; i < *len; i++)
1906                         kfree((*names)[i]);
1907         }
1908         kfree(*values);
1909         goto out;
1910 }
1911
1912
1913 int security_set_bools(int len, int *values)
1914 {
1915         int i, rc = 0;
1916         int lenp, seqno = 0;
1917         struct cond_node *cur;
1918
1919         POLICY_WRLOCK;
1920
1921         lenp = policydb.p_bools.nprim;
1922         if (len != lenp) {
1923                 rc = -EFAULT;
1924                 goto out;
1925         }
1926
1927         for (i = 0; i < len; i++) {
1928                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1929                         audit_log(current->audit_context, GFP_ATOMIC,
1930                                 AUDIT_MAC_CONFIG_CHANGE,
1931                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
1932                                 policydb.p_bool_val_to_name[i],
1933                                 !!values[i],
1934                                 policydb.bool_val_to_struct[i]->state,
1935                                 audit_get_loginuid(current),
1936                                 audit_get_sessionid(current));
1937                 }
1938                 if (values[i])
1939                         policydb.bool_val_to_struct[i]->state = 1;
1940                 else
1941                         policydb.bool_val_to_struct[i]->state = 0;
1942         }
1943
1944         for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1945                 rc = evaluate_cond_node(&policydb, cur);
1946                 if (rc)
1947                         goto out;
1948         }
1949
1950         seqno = ++latest_granting;
1951
1952 out:
1953         POLICY_WRUNLOCK;
1954         if (!rc) {
1955                 avc_ss_reset(seqno);
1956                 selnl_notify_policyload(seqno);
1957                 selinux_xfrm_notify_policyload();
1958         }
1959         return rc;
1960 }
1961
1962 int security_get_bool_value(int bool)
1963 {
1964         int rc = 0;
1965         int len;
1966
1967         POLICY_RDLOCK;
1968
1969         len = policydb.p_bools.nprim;
1970         if (bool >= len) {
1971                 rc = -EFAULT;
1972                 goto out;
1973         }
1974
1975         rc = policydb.bool_val_to_struct[bool]->state;
1976 out:
1977         POLICY_RDUNLOCK;
1978         return rc;
1979 }
1980
1981 static int security_preserve_bools(struct policydb *p)
1982 {
1983         int rc, nbools = 0, *bvalues = NULL, i;
1984         char **bnames = NULL;
1985         struct cond_bool_datum *booldatum;
1986         struct cond_node *cur;
1987
1988         rc = security_get_bools(&nbools, &bnames, &bvalues);
1989         if (rc)
1990                 goto out;
1991         for (i = 0; i < nbools; i++) {
1992                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
1993                 if (booldatum)
1994                         booldatum->state = bvalues[i];
1995         }
1996         for (cur = p->cond_list; cur != NULL; cur = cur->next) {
1997                 rc = evaluate_cond_node(p, cur);
1998                 if (rc)
1999                         goto out;
2000         }
2001
2002 out:
2003         if (bnames) {
2004                 for (i = 0; i < nbools; i++)
2005                         kfree(bnames[i]);
2006         }
2007         kfree(bnames);
2008         kfree(bvalues);
2009         return rc;
2010 }
2011
2012 /*
2013  * security_sid_mls_copy() - computes a new sid based on the given
2014  * sid and the mls portion of mls_sid.
2015  */
2016 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2017 {
2018         struct context *context1;
2019         struct context *context2;
2020         struct context newcon;
2021         char *s;
2022         u32 len;
2023         int rc = 0;
2024
2025         if (!ss_initialized || !selinux_mls_enabled) {
2026                 *new_sid = sid;
2027                 goto out;
2028         }
2029
2030         context_init(&newcon);
2031
2032         POLICY_RDLOCK;
2033         context1 = sidtab_search(&sidtab, sid);
2034         if (!context1) {
2035                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2036                         __func__, sid);
2037                 rc = -EINVAL;
2038                 goto out_unlock;
2039         }
2040
2041         context2 = sidtab_search(&sidtab, mls_sid);
2042         if (!context2) {
2043                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2044                         __func__, mls_sid);
2045                 rc = -EINVAL;
2046                 goto out_unlock;
2047         }
2048
2049         newcon.user = context1->user;
2050         newcon.role = context1->role;
2051         newcon.type = context1->type;
2052         rc = mls_context_cpy(&newcon, context2);
2053         if (rc)
2054                 goto out_unlock;
2055
2056         /* Check the validity of the new context. */
2057         if (!policydb_context_isvalid(&policydb, &newcon)) {
2058                 rc = convert_context_handle_invalid_context(&newcon);
2059                 if (rc)
2060                         goto bad;
2061         }
2062
2063         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2064         goto out_unlock;
2065
2066 bad:
2067         if (!context_struct_to_string(&newcon, &s, &len)) {
2068                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2069                           "security_sid_mls_copy: invalid context %s", s);
2070                 kfree(s);
2071         }
2072
2073 out_unlock:
2074         POLICY_RDUNLOCK;
2075         context_destroy(&newcon);
2076 out:
2077         return rc;
2078 }
2079
2080 /**
2081  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2082  * @nlbl_sid: NetLabel SID
2083  * @nlbl_type: NetLabel labeling protocol type
2084  * @xfrm_sid: XFRM SID
2085  *
2086  * Description:
2087  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2088  * resolved into a single SID it is returned via @peer_sid and the function
2089  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2090  * returns a negative value.  A table summarizing the behavior is below:
2091  *
2092  *                                 | function return |      @sid
2093  *   ------------------------------+-----------------+-----------------
2094  *   no peer labels                |        0        |    SECSID_NULL
2095  *   single peer label             |        0        |    <peer_label>
2096  *   multiple, consistent labels   |        0        |    <peer_label>
2097  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2098  *
2099  */
2100 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2101                                  u32 xfrm_sid,
2102                                  u32 *peer_sid)
2103 {
2104         int rc;
2105         struct context *nlbl_ctx;
2106         struct context *xfrm_ctx;
2107
2108         /* handle the common (which also happens to be the set of easy) cases
2109          * right away, these two if statements catch everything involving a
2110          * single or absent peer SID/label */
2111         if (xfrm_sid == SECSID_NULL) {
2112                 *peer_sid = nlbl_sid;
2113                 return 0;
2114         }
2115         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2116          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2117          * is present */
2118         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2119                 *peer_sid = xfrm_sid;
2120                 return 0;
2121         }
2122
2123         /* we don't need to check ss_initialized here since the only way both
2124          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2125          * security server was initialized and ss_initialized was true */
2126         if (!selinux_mls_enabled) {
2127                 *peer_sid = SECSID_NULL;
2128                 return 0;
2129         }
2130
2131         POLICY_RDLOCK;
2132
2133         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2134         if (!nlbl_ctx) {
2135                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2136                        __func__, nlbl_sid);
2137                 rc = -EINVAL;
2138                 goto out_slowpath;
2139         }
2140         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2141         if (!xfrm_ctx) {
2142                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2143                        __func__, xfrm_sid);
2144                 rc = -EINVAL;
2145                 goto out_slowpath;
2146         }
2147         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2148
2149 out_slowpath:
2150         POLICY_RDUNLOCK;
2151         if (rc == 0)
2152                 /* at present NetLabel SIDs/labels really only carry MLS
2153                  * information so if the MLS portion of the NetLabel SID
2154                  * matches the MLS portion of the labeled XFRM SID/label
2155                  * then pass along the XFRM SID as it is the most
2156                  * expressive */
2157                 *peer_sid = xfrm_sid;
2158         else
2159                 *peer_sid = SECSID_NULL;
2160         return rc;
2161 }
2162
2163 static int get_classes_callback(void *k, void *d, void *args)
2164 {
2165         struct class_datum *datum = d;
2166         char *name = k, **classes = args;
2167         int value = datum->value - 1;
2168
2169         classes[value] = kstrdup(name, GFP_ATOMIC);
2170         if (!classes[value])
2171                 return -ENOMEM;
2172
2173         return 0;
2174 }
2175
2176 int security_get_classes(char ***classes, int *nclasses)
2177 {
2178         int rc = -ENOMEM;
2179
2180         POLICY_RDLOCK;
2181
2182         *nclasses = policydb.p_classes.nprim;
2183         *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2184         if (!*classes)
2185                 goto out;
2186
2187         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2188                         *classes);
2189         if (rc < 0) {
2190                 int i;
2191                 for (i = 0; i < *nclasses; i++)
2192                         kfree((*classes)[i]);
2193                 kfree(*classes);
2194         }
2195
2196 out:
2197         POLICY_RDUNLOCK;
2198         return rc;
2199 }
2200
2201 static int get_permissions_callback(void *k, void *d, void *args)
2202 {
2203         struct perm_datum *datum = d;
2204         char *name = k, **perms = args;
2205         int value = datum->value - 1;
2206
2207         perms[value] = kstrdup(name, GFP_ATOMIC);
2208         if (!perms[value])
2209                 return -ENOMEM;
2210
2211         return 0;
2212 }
2213
2214 int security_get_permissions(char *class, char ***perms, int *nperms)
2215 {
2216         int rc = -ENOMEM, i;
2217         struct class_datum *match;
2218
2219         POLICY_RDLOCK;
2220
2221         match = hashtab_search(policydb.p_classes.table, class);
2222         if (!match) {
2223                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2224                         __func__, class);
2225                 rc = -EINVAL;
2226                 goto out;
2227         }
2228
2229         *nperms = match->permissions.nprim;
2230         *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2231         if (!*perms)
2232                 goto out;
2233
2234         if (match->comdatum) {
2235                 rc = hashtab_map(match->comdatum->permissions.table,
2236                                 get_permissions_callback, *perms);
2237                 if (rc < 0)
2238                         goto err;
2239         }
2240
2241         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2242                         *perms);
2243         if (rc < 0)
2244                 goto err;
2245
2246 out:
2247         POLICY_RDUNLOCK;
2248         return rc;
2249
2250 err:
2251         POLICY_RDUNLOCK;
2252         for (i = 0; i < *nperms; i++)
2253                 kfree((*perms)[i]);
2254         kfree(*perms);
2255         return rc;
2256 }
2257
2258 int security_get_reject_unknown(void)
2259 {
2260         return policydb.reject_unknown;
2261 }
2262
2263 int security_get_allow_unknown(void)
2264 {
2265         return policydb.allow_unknown;
2266 }
2267
2268 /**
2269  * security_policycap_supported - Check for a specific policy capability
2270  * @req_cap: capability
2271  *
2272  * Description:
2273  * This function queries the currently loaded policy to see if it supports the
2274  * capability specified by @req_cap.  Returns true (1) if the capability is
2275  * supported, false (0) if it isn't supported.
2276  *
2277  */
2278 int security_policycap_supported(unsigned int req_cap)
2279 {
2280         int rc;
2281
2282         POLICY_RDLOCK;
2283         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2284         POLICY_RDUNLOCK;
2285
2286         return rc;
2287 }
2288
2289 struct selinux_audit_rule {
2290         u32 au_seqno;
2291         struct context au_ctxt;
2292 };
2293
2294 void selinux_audit_rule_free(void *vrule)
2295 {
2296         struct selinux_audit_rule *rule = vrule;
2297
2298         if (rule) {
2299                 context_destroy(&rule->au_ctxt);
2300                 kfree(rule);
2301         }
2302 }
2303
2304 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2305 {
2306         struct selinux_audit_rule *tmprule;
2307         struct role_datum *roledatum;
2308         struct type_datum *typedatum;
2309         struct user_datum *userdatum;
2310         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2311         int rc = 0;
2312
2313         *rule = NULL;
2314
2315         if (!ss_initialized)
2316                 return -EOPNOTSUPP;
2317
2318         switch (field) {
2319         case AUDIT_SUBJ_USER:
2320         case AUDIT_SUBJ_ROLE:
2321         case AUDIT_SUBJ_TYPE:
2322         case AUDIT_OBJ_USER:
2323         case AUDIT_OBJ_ROLE:
2324         case AUDIT_OBJ_TYPE:
2325                 /* only 'equals' and 'not equals' fit user, role, and type */
2326                 if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2327                         return -EINVAL;
2328                 break;
2329         case AUDIT_SUBJ_SEN:
2330         case AUDIT_SUBJ_CLR:
2331         case AUDIT_OBJ_LEV_LOW:
2332         case AUDIT_OBJ_LEV_HIGH:
2333                 /* we do not allow a range, indicated by the presense of '-' */
2334                 if (strchr(rulestr, '-'))
2335                         return -EINVAL;
2336                 break;
2337         default:
2338                 /* only the above fields are valid */
2339                 return -EINVAL;
2340         }
2341
2342         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2343         if (!tmprule)
2344                 return -ENOMEM;
2345
2346         context_init(&tmprule->au_ctxt);
2347
2348         POLICY_RDLOCK;
2349
2350         tmprule->au_seqno = latest_granting;
2351
2352         switch (field) {
2353         case AUDIT_SUBJ_USER:
2354         case AUDIT_OBJ_USER:
2355                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2356                 if (!userdatum)
2357                         rc = -EINVAL;
2358                 else
2359                         tmprule->au_ctxt.user = userdatum->value;
2360                 break;
2361         case AUDIT_SUBJ_ROLE:
2362         case AUDIT_OBJ_ROLE:
2363                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2364                 if (!roledatum)
2365                         rc = -EINVAL;
2366                 else
2367                         tmprule->au_ctxt.role = roledatum->value;
2368                 break;
2369         case AUDIT_SUBJ_TYPE:
2370         case AUDIT_OBJ_TYPE:
2371                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2372                 if (!typedatum)
2373                         rc = -EINVAL;
2374                 else
2375                         tmprule->au_ctxt.type = typedatum->value;
2376                 break;
2377         case AUDIT_SUBJ_SEN:
2378         case AUDIT_SUBJ_CLR:
2379         case AUDIT_OBJ_LEV_LOW:
2380         case AUDIT_OBJ_LEV_HIGH:
2381                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2382                 break;
2383         }
2384
2385         POLICY_RDUNLOCK;
2386
2387         if (rc) {
2388                 selinux_audit_rule_free(tmprule);
2389                 tmprule = NULL;
2390         }
2391
2392         *rule = tmprule;
2393
2394         return rc;
2395 }
2396
2397 /* Check to see if the rule contains any selinux fields */
2398 int selinux_audit_rule_known(struct audit_krule *rule)
2399 {
2400         int i;
2401
2402         for (i = 0; i < rule->field_count; i++) {
2403                 struct audit_field *f = &rule->fields[i];
2404                 switch (f->type) {
2405                 case AUDIT_SUBJ_USER:
2406                 case AUDIT_SUBJ_ROLE:
2407                 case AUDIT_SUBJ_TYPE:
2408                 case AUDIT_SUBJ_SEN:
2409                 case AUDIT_SUBJ_CLR:
2410                 case AUDIT_OBJ_USER:
2411                 case AUDIT_OBJ_ROLE:
2412                 case AUDIT_OBJ_TYPE:
2413                 case AUDIT_OBJ_LEV_LOW:
2414                 case AUDIT_OBJ_LEV_HIGH:
2415                         return 1;
2416                 }
2417         }
2418
2419         return 0;
2420 }
2421
2422 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2423                              struct audit_context *actx)
2424 {
2425         struct context *ctxt;
2426         struct mls_level *level;
2427         struct selinux_audit_rule *rule = vrule;
2428         int match = 0;
2429
2430         if (!rule) {
2431                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2432                           "selinux_audit_rule_match: missing rule\n");
2433                 return -ENOENT;
2434         }
2435
2436         POLICY_RDLOCK;
2437
2438         if (rule->au_seqno < latest_granting) {
2439                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2440                           "selinux_audit_rule_match: stale rule\n");
2441                 match = -ESTALE;
2442                 goto out;
2443         }
2444
2445         ctxt = sidtab_search(&sidtab, sid);
2446         if (!ctxt) {
2447                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2448                           "selinux_audit_rule_match: unrecognized SID %d\n",
2449                           sid);
2450                 match = -ENOENT;
2451                 goto out;
2452         }
2453
2454         /* a field/op pair that is not caught here will simply fall through
2455            without a match */
2456         switch (field) {
2457         case AUDIT_SUBJ_USER:
2458         case AUDIT_OBJ_USER:
2459                 switch (op) {
2460                 case AUDIT_EQUAL:
2461                         match = (ctxt->user == rule->au_ctxt.user);
2462                         break;
2463                 case AUDIT_NOT_EQUAL:
2464                         match = (ctxt->user != rule->au_ctxt.user);
2465                         break;
2466                 }
2467                 break;
2468         case AUDIT_SUBJ_ROLE:
2469         case AUDIT_OBJ_ROLE:
2470                 switch (op) {
2471                 case AUDIT_EQUAL:
2472                         match = (ctxt->role == rule->au_ctxt.role);
2473                         break;
2474                 case AUDIT_NOT_EQUAL:
2475                         match = (ctxt->role != rule->au_ctxt.role);
2476                         break;
2477                 }
2478                 break;
2479         case AUDIT_SUBJ_TYPE:
2480         case AUDIT_OBJ_TYPE:
2481                 switch (op) {
2482                 case AUDIT_EQUAL:
2483                         match = (ctxt->type == rule->au_ctxt.type);
2484                         break;
2485                 case AUDIT_NOT_EQUAL:
2486                         match = (ctxt->type != rule->au_ctxt.type);
2487                         break;
2488                 }
2489                 break;
2490         case AUDIT_SUBJ_SEN:
2491         case AUDIT_SUBJ_CLR:
2492         case AUDIT_OBJ_LEV_LOW:
2493         case AUDIT_OBJ_LEV_HIGH:
2494                 level = ((field == AUDIT_SUBJ_SEN ||
2495                           field == AUDIT_OBJ_LEV_LOW) ?
2496                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2497                 switch (op) {
2498                 case AUDIT_EQUAL:
2499                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2500                                              level);
2501                         break;
2502                 case AUDIT_NOT_EQUAL:
2503                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2504                                               level);
2505                         break;
2506                 case AUDIT_LESS_THAN:
2507                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2508                                                level) &&
2509                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2510                                                level));
2511                         break;
2512                 case AUDIT_LESS_THAN_OR_EQUAL:
2513                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2514                                               level);
2515                         break;
2516                 case AUDIT_GREATER_THAN:
2517                         match = (mls_level_dom(level,
2518                                               &rule->au_ctxt.range.level[0]) &&
2519                                  !mls_level_eq(level,
2520                                                &rule->au_ctxt.range.level[0]));
2521                         break;
2522                 case AUDIT_GREATER_THAN_OR_EQUAL:
2523                         match = mls_level_dom(level,
2524                                               &rule->au_ctxt.range.level[0]);
2525                         break;
2526                 }
2527         }
2528
2529 out:
2530         POLICY_RDUNLOCK;
2531         return match;
2532 }
2533
2534 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2535
2536 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2537                                u16 class, u32 perms, u32 *retained)
2538 {
2539         int err = 0;
2540
2541         if (event == AVC_CALLBACK_RESET && aurule_callback)
2542                 err = aurule_callback();
2543         return err;
2544 }
2545
2546 static int __init aurule_init(void)
2547 {
2548         int err;
2549
2550         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2551                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2552         if (err)
2553                 panic("avc_add_callback() failed, error %d\n", err);
2554
2555         return err;
2556 }
2557 __initcall(aurule_init);
2558
2559 #ifdef CONFIG_NETLABEL
2560 /**
2561  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2562  * @secattr: the NetLabel packet security attributes
2563  * @sid: the SELinux SID
2564  *
2565  * Description:
2566  * Attempt to cache the context in @ctx, which was derived from the packet in
2567  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2568  * already been initialized.
2569  *
2570  */
2571 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2572                                       u32 sid)
2573 {
2574         u32 *sid_cache;
2575
2576         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
2577         if (sid_cache == NULL)
2578                 return;
2579         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2580         if (secattr->cache == NULL) {
2581                 kfree(sid_cache);
2582                 return;
2583         }
2584
2585         *sid_cache = sid;
2586         secattr->cache->free = kfree;
2587         secattr->cache->data = sid_cache;
2588         secattr->flags |= NETLBL_SECATTR_CACHE;
2589 }
2590
2591 /**
2592  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2593  * @secattr: the NetLabel packet security attributes
2594  * @sid: the SELinux SID
2595  *
2596  * Description:
2597  * Convert the given NetLabel security attributes in @secattr into a
2598  * SELinux SID.  If the @secattr field does not contain a full SELinux
2599  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
2600  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
2601  * allow the @secattr to be used by NetLabel to cache the secattr to SID
2602  * conversion for future lookups.  Returns zero on success, negative values on
2603  * failure.
2604  *
2605  */
2606 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2607                                    u32 *sid)
2608 {
2609         int rc = -EIDRM;
2610         struct context *ctx;
2611         struct context ctx_new;
2612
2613         if (!ss_initialized) {
2614                 *sid = SECSID_NULL;
2615                 return 0;
2616         }
2617
2618         POLICY_RDLOCK;
2619
2620         if (secattr->flags & NETLBL_SECATTR_CACHE) {
2621                 *sid = *(u32 *)secattr->cache->data;
2622                 rc = 0;
2623         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
2624                 *sid = secattr->attr.secid;
2625                 rc = 0;
2626         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2627                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
2628                 if (ctx == NULL)
2629                         goto netlbl_secattr_to_sid_return;
2630
2631                 ctx_new.user = ctx->user;
2632                 ctx_new.role = ctx->role;
2633                 ctx_new.type = ctx->type;
2634                 mls_import_netlbl_lvl(&ctx_new, secattr);
2635                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2636                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2637                                                   secattr->attr.mls.cat) != 0)
2638                                 goto netlbl_secattr_to_sid_return;
2639                         ctx_new.range.level[1].cat.highbit =
2640                                 ctx_new.range.level[0].cat.highbit;
2641                         ctx_new.range.level[1].cat.node =
2642                                 ctx_new.range.level[0].cat.node;
2643                 } else {
2644                         ebitmap_init(&ctx_new.range.level[0].cat);
2645                         ebitmap_init(&ctx_new.range.level[1].cat);
2646                 }
2647                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2648                         goto netlbl_secattr_to_sid_return_cleanup;
2649
2650                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2651                 if (rc != 0)
2652                         goto netlbl_secattr_to_sid_return_cleanup;
2653
2654                 security_netlbl_cache_add(secattr, *sid);
2655
2656                 ebitmap_destroy(&ctx_new.range.level[0].cat);
2657         } else {
2658                 *sid = SECSID_NULL;
2659                 rc = 0;
2660         }
2661
2662 netlbl_secattr_to_sid_return:
2663         POLICY_RDUNLOCK;
2664         return rc;
2665 netlbl_secattr_to_sid_return_cleanup:
2666         ebitmap_destroy(&ctx_new.range.level[0].cat);
2667         goto netlbl_secattr_to_sid_return;
2668 }
2669
2670 /**
2671  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2672  * @sid: the SELinux SID
2673  * @secattr: the NetLabel packet security attributes
2674  *
2675  * Description:
2676  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2677  * Returns zero on success, negative values on failure.
2678  *
2679  */
2680 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2681 {
2682         int rc = -ENOENT;
2683         struct context *ctx;
2684
2685         if (!ss_initialized)
2686                 return 0;
2687
2688         POLICY_RDLOCK;
2689         ctx = sidtab_search(&sidtab, sid);
2690         if (ctx == NULL)
2691                 goto netlbl_sid_to_secattr_failure;
2692         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2693                                   GFP_ATOMIC);
2694         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY;
2695         mls_export_netlbl_lvl(ctx, secattr);
2696         rc = mls_export_netlbl_cat(ctx, secattr);
2697         if (rc != 0)
2698                 goto netlbl_sid_to_secattr_failure;
2699         POLICY_RDUNLOCK;
2700
2701         return 0;
2702
2703 netlbl_sid_to_secattr_failure:
2704         POLICY_RDUNLOCK;
2705         return rc;
2706 }
2707 #endif /* CONFIG_NETLABEL */