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