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  *
  11  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  12  *
  13  *      Added conditional policy language extensions
  14  *
  15  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  16  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  17  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  18  *      This program is free software; you can redistribute it and/or modify
  19  *      it under the terms of the GNU General Public License as published by
  20  *      the Free Software Foundation, version 2.
  21  */
  22 #include <linux/kernel.h>
  23 #include <linux/slab.h>
  24 #include <linux/string.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/errno.h>
  27 #include <linux/in.h>
  28 #include <linux/sched.h>
  29 #include <linux/audit.h>
  30 #include <asm/semaphore.h>
  31 #include "flask.h"
  32 #include "avc.h"
  33 #include "avc_ss.h"
  34 #include "security.h"
  35 #include "context.h"
  36 #include "policydb.h"
  37 #include "sidtab.h"
  38 #include "services.h"
  39 #include "conditional.h"
  40 #include "mls.h"
  41
  42 extern void selnl_notify_policyload(u32 seqno);
  43 unsigned int policydb_loaded_version;
  44
  45 static DEFINE_RWLOCK(policy_rwlock);
  46 #define POLICY_RDLOCK read_lock(&policy_rwlock)
  47 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
  48 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
  49 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
  50
  51 static DECLARE_MUTEX(load_sem);
  52 #define LOAD_LOCK down(&load_sem)
  53 #define LOAD_UNLOCK up(&load_sem)
  54
  55 static struct sidtab sidtab;
  56 struct policydb policydb;
  57 int ss_initialized = 0;
  58
  59 /*
  60  * The largest sequence number that has been used when
  61  * providing an access decision to the access vector cache.
  62  * The sequence number only changes when a policy change
  63  * occurs.
  64  */
  65 static u32 latest_granting = 0;
  66
  67 /* Forward declaration. */
  68 static int context_struct_to_string(struct context *context, char **scontext,
  69                                     u32 *scontext_len);
  70
  71 /*
  72  * Return the boolean value of a constraint expression
  73  * when it is applied to the specified source and target
  74  * security contexts.
  75  *
  76  * xcontext is a special beast...  It is used by the validatetrans rules
  77  * only.  For these rules, scontext is the context before the transition,
  78  * tcontext is the context after the transition, and xcontext is the context
  79  * of the process performing the transition.  All other callers of
  80  * constraint_expr_eval should pass in NULL for xcontext.
  81  */
  82 static int constraint_expr_eval(struct context *scontext,
  83                                 struct context *tcontext,
  84                                 struct context *xcontext,
  85                                 struct constraint_expr *cexpr)
  86 {
  87         u32 val1, val2;
  88         struct context *c;
  89         struct role_datum *r1, *r2;
  90         struct mls_level *l1, *l2;
  91         struct constraint_expr *e;
  92         int s[CEXPR_MAXDEPTH];
  93         int sp = -1;
  94
  95         for (e = cexpr; e; e = e->next) {
  96                 switch (e->expr_type) {
  97                 case CEXPR_NOT:
  98                         BUG_ON(sp < 0);
  99                         s[sp] = !s[sp];
 100                         break;
 101                 case CEXPR_AND:
 102                         BUG_ON(sp < 1);
 103                         sp--;
 104                         s[sp] &= s[sp+1];
 105                         break;
 106                 case CEXPR_OR:
 107                         BUG_ON(sp < 1);
 108                         sp--;
 109                         s[sp] |= s[sp+1];
 110                         break;
 111                 case CEXPR_ATTR:
 112                         if (sp == (CEXPR_MAXDEPTH-1))
 113                                 return 0;
 114                         switch (e->attr) {
 115                         case CEXPR_USER:
 116                                 val1 = scontext->user;
 117                                 val2 = tcontext->user;
 118                                 break;
 119                         case CEXPR_TYPE:
 120                                 val1 = scontext->type;
 121                                 val2 = tcontext->type;
 122                                 break;
 123                         case CEXPR_ROLE:
 124                                 val1 = scontext->role;
 125                                 val2 = tcontext->role;
 126                                 r1 = policydb.role_val_to_struct[val1 - 1];
 127                                 r2 = policydb.role_val_to_struct[val2 - 1];
 128                                 switch (e->op) {
 129                                 case CEXPR_DOM:
 130                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 131                                                                   val2 - 1);
 132                                         continue;
 133                                 case CEXPR_DOMBY:
 134                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 135                                                                   val1 - 1);
 136                                         continue;
 137                                 case CEXPR_INCOMP:
 138                                         s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
 139                                                                      val2 - 1) &&
 140                                                     !ebitmap_get_bit(&r2->dominates,
 141                                                                      val1 - 1) );
 142                                         continue;
 143                                 default:
 144                                         break;
 145                                 }
 146                                 break;
 147                         case CEXPR_L1L2:
 148                                 l1 = &(scontext->range.level[0]);
 149                                 l2 = &(tcontext->range.level[0]);
 150                                 goto mls_ops;
 151                         case CEXPR_L1H2:
 152                                 l1 = &(scontext->range.level[0]);
 153                                 l2 = &(tcontext->range.level[1]);
 154                                 goto mls_ops;
 155                         case CEXPR_H1L2:
 156                                 l1 = &(scontext->range.level[1]);
 157                                 l2 = &(tcontext->range.level[0]);
 158                                 goto mls_ops;
 159                         case CEXPR_H1H2:
 160                                 l1 = &(scontext->range.level[1]);
 161                                 l2 = &(tcontext->range.level[1]);
 162                                 goto mls_ops;
 163                         case CEXPR_L1H1:
 164                                 l1 = &(scontext->range.level[0]);
 165                                 l2 = &(scontext->range.level[1]);
 166                                 goto mls_ops;
 167                         case CEXPR_L2H2:
 168                                 l1 = &(tcontext->range.level[0]);
 169                                 l2 = &(tcontext->range.level[1]);
 170                                 goto mls_ops;
 171 mls_ops:
 172                         switch (e->op) {
 173                         case CEXPR_EQ:
 174                                 s[++sp] = mls_level_eq(l1, l2);
 175                                 continue;
 176                         case CEXPR_NEQ:
 177                                 s[++sp] = !mls_level_eq(l1, l2);
 178                                 continue;
 179                         case CEXPR_DOM:
 180                                 s[++sp] = mls_level_dom(l1, l2);
 181                                 continue;
 182                         case CEXPR_DOMBY:
 183                                 s[++sp] = mls_level_dom(l2, l1);
 184                                 continue;
 185                         case CEXPR_INCOMP:
 186                                 s[++sp] = mls_level_incomp(l2, l1);
 187                                 continue;
 188                         default:
 189                                 BUG();
 190                                 return 0;
 191                         }
 192                         break;
 193                         default:
 194                                 BUG();
 195                                 return 0;
 196                         }
 197
 198                         switch (e->op) {
 199                         case CEXPR_EQ:
 200                                 s[++sp] = (val1 == val2);
 201                                 break;
 202                         case CEXPR_NEQ:
 203                                 s[++sp] = (val1 != val2);
 204                                 break;
 205                         default:
 206                                 BUG();
 207                                 return 0;
 208                         }
 209                         break;
 210                 case CEXPR_NAMES:
 211                         if (sp == (CEXPR_MAXDEPTH-1))
 212                                 return 0;
 213                         c = scontext;
 214                         if (e->attr & CEXPR_TARGET)
 215                                 c = tcontext;
 216                         else if (e->attr & CEXPR_XTARGET) {
 217                                 c = xcontext;
 218                                 if (!c) {
 219                                         BUG();
 220                                         return 0;
 221                                 }
 222                         }
 223                         if (e->attr & CEXPR_USER)
 224                                 val1 = c->user;
 225                         else if (e->attr & CEXPR_ROLE)
 226                                 val1 = c->role;
 227                         else if (e->attr & CEXPR_TYPE)
 228                                 val1 = c->type;
 229                         else {
 230                                 BUG();
 231                                 return 0;
 232                         }
 233
 234                         switch (e->op) {
 235                         case CEXPR_EQ:
 236                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 237                                 break;
 238                         case CEXPR_NEQ:
 239                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 240                                 break;
 241                         default:
 242                                 BUG();
 243                                 return 0;
 244                         }
 245                         break;
 246                 default:
 247                         BUG();
 248                         return 0;
 249                 }
 250         }
 251
 252         BUG_ON(sp != 0);
 253         return s[0];
 254 }
 255
 256 /*
 257  * Compute access vectors based on a context structure pair for
 258  * the permissions in a particular class.
 259  */
 260 static int context_struct_compute_av(struct context *scontext,
 261                                      struct context *tcontext,
 262                                      u16 tclass,
 263                                      u32 requested,
 264                                      struct av_decision *avd)
 265 {
 266         struct constraint_node *constraint;
 267         struct role_allow *ra;
 268         struct avtab_key avkey;
 269         struct avtab_datum *avdatum;
 270         struct class_datum *tclass_datum;
 271
 272         /*
 273          * Remap extended Netlink classes for old policy versions.
 274          * Do this here rather than socket_type_to_security_class()
 275          * in case a newer policy version is loaded, allowing sockets
 276          * to remain in the correct class.
 277          */
 278         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 279                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 280                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 281                         tclass = SECCLASS_NETLINK_SOCKET;
 282
 283         if (!tclass || tclass > policydb.p_classes.nprim) {
 284                 printk(KERN_ERR "security_compute_av:  unrecognized class %d\n",
 285                        tclass);
 286                 return -EINVAL;
 287         }
 288         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 289
 290         /*
 291          * Initialize the access vectors to the default values.
 292          */
 293         avd->allowed = 0;
 294         avd->decided = 0xffffffff;
 295         avd->auditallow = 0;
 296         avd->auditdeny = 0xffffffff;
 297         avd->seqno = latest_granting;
 298
 299         /*
 300          * If a specific type enforcement rule was defined for
 301          * this permission check, then use it.
 302          */
 303         avkey.source_type = scontext->type;
 304         avkey.target_type = tcontext->type;
 305         avkey.target_class = tclass;
 306         avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_AV);
 307         if (avdatum) {
 308                 if (avdatum->specified & AVTAB_ALLOWED)
 309                         avd->allowed = avtab_allowed(avdatum);
 310                 if (avdatum->specified & AVTAB_AUDITDENY)
 311                         avd->auditdeny = avtab_auditdeny(avdatum);
 312                 if (avdatum->specified & AVTAB_AUDITALLOW)
 313                         avd->auditallow = avtab_auditallow(avdatum);
 314         }
 315
 316         /* Check conditional av table for additional permissions */
 317         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 318
 319         /*
 320          * Remove any permissions prohibited by a constraint (this includes
 321          * the MLS policy).
 322          */
 323         constraint = tclass_datum->constraints;
 324         while (constraint) {
 325                 if ((constraint->permissions & (avd->allowed)) &&
 326                     !constraint_expr_eval(scontext, tcontext, NULL,
 327                                           constraint->expr)) {
 328                         avd->allowed = (avd->allowed) & ~(constraint->permissions);
 329                 }
 330                 constraint = constraint->next;
 331         }
 332
 333         /*
 334          * If checking process transition permission and the
 335          * role is changing, then check the (current_role, new_role)
 336          * pair.
 337          */
 338         if (tclass == SECCLASS_PROCESS &&
 339             (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
 340             scontext->role != tcontext->role) {
 341                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 342                         if (scontext->role == ra->role &&
 343                             tcontext->role == ra->new_role)
 344                                 break;
 345                 }
 346                 if (!ra)
 347                         avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
 348                                                         PROCESS__DYNTRANSITION);
 349         }
 350
 351         return 0;
 352 }
 353
 354 static int security_validtrans_handle_fail(struct context *ocontext,
 355                                            struct context *ncontext,
 356                                            struct context *tcontext,
 357                                            u16 tclass)
 358 {
 359         char *o = NULL, *n = NULL, *t = NULL;
 360         u32 olen, nlen, tlen;
 361
 362         if (context_struct_to_string(ocontext, &o, &olen) < 0)
 363                 goto out;
 364         if (context_struct_to_string(ncontext, &n, &nlen) < 0)
 365                 goto out;
 366         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 367                 goto out;
 368         audit_log(current->audit_context,
 369                   "security_validate_transition:  denied for"
 370                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 371                   o, n, t, policydb.p_class_val_to_name[tclass-1]);
 372 out:
 373         kfree(o);
 374         kfree(n);
 375         kfree(t);
 376
 377         if (!selinux_enforcing)
 378                 return 0;
 379         return -EPERM;
 380 }
 381
 382 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 383                                  u16 tclass)
 384 {
 385         struct context *ocontext;
 386         struct context *ncontext;
 387         struct context *tcontext;
 388         struct class_datum *tclass_datum;
 389         struct constraint_node *constraint;
 390         int rc = 0;
 391
 392         if (!ss_initialized)
 393                 return 0;
 394
 395         POLICY_RDLOCK;
 396
 397         /*
 398          * Remap extended Netlink classes for old policy versions.
 399          * Do this here rather than socket_type_to_security_class()
 400          * in case a newer policy version is loaded, allowing sockets
 401          * to remain in the correct class.
 402          */
 403         if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 404                 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 405                     tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 406                         tclass = SECCLASS_NETLINK_SOCKET;
 407
 408         if (!tclass || tclass > policydb.p_classes.nprim) {
 409                 printk(KERN_ERR "security_validate_transition:  "
 410                        "unrecognized class %d\n", tclass);
 411                 rc = -EINVAL;
 412                 goto out;
 413         }
 414         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 415
 416         ocontext = sidtab_search(&sidtab, oldsid);
 417         if (!ocontext) {
 418                 printk(KERN_ERR "security_validate_transition: "
 419                        " unrecognized SID %d\n", oldsid);
 420                 rc = -EINVAL;
 421                 goto out;
 422         }
 423
 424         ncontext = sidtab_search(&sidtab, newsid);
 425         if (!ncontext) {
 426                 printk(KERN_ERR "security_validate_transition: "
 427                        " unrecognized SID %d\n", newsid);
 428                 rc = -EINVAL;
 429                 goto out;
 430         }
 431
 432         tcontext = sidtab_search(&sidtab, tasksid);
 433         if (!tcontext) {
 434                 printk(KERN_ERR "security_validate_transition: "
 435                        " unrecognized SID %d\n", tasksid);
 436                 rc = -EINVAL;
 437                 goto out;
 438         }
 439
 440         constraint = tclass_datum->validatetrans;
 441         while (constraint) {
 442                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 443                                           constraint->expr)) {
 444                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 445                                                              tcontext, tclass);
 446                         goto out;
 447                 }
 448                 constraint = constraint->next;
 449         }
 450
 451 out:
 452         POLICY_RDUNLOCK;
 453         return rc;
 454 }
 455
 456 /**
 457  * security_compute_av - Compute access vector decisions.
 458  * @ssid: source security identifier
 459  * @tsid: target security identifier
 460  * @tclass: target security class
 461  * @requested: requested permissions
 462  * @avd: access vector decisions
 463  *
 464  * Compute a set of access vector decisions based on the
 465  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 466  * Return -%EINVAL if any of the parameters are invalid or %0
 467  * if the access vector decisions were computed successfully.
 468  */
 469 int security_compute_av(u32 ssid,
 470                         u32 tsid,
 471                         u16 tclass,
 472                         u32 requested,
 473                         struct av_decision *avd)
 474 {
 475         struct context *scontext = NULL, *tcontext = NULL;
 476         int rc = 0;
 477
 478         if (!ss_initialized) {
 479                 avd->allowed = requested;
 480                 avd->decided = requested;
 481                 avd->auditallow = 0;
 482                 avd->auditdeny = 0xffffffff;
 483                 avd->seqno = latest_granting;
 484                 return 0;
 485         }
 486
 487         POLICY_RDLOCK;
 488
 489         scontext = sidtab_search(&sidtab, ssid);
 490         if (!scontext) {
 491                 printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
 492                        ssid);
 493                 rc = -EINVAL;
 494                 goto out;
 495         }
 496         tcontext = sidtab_search(&sidtab, tsid);
 497         if (!tcontext) {
 498                 printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
 499                        tsid);
 500                 rc = -EINVAL;
 501                 goto out;
 502         }
 503
 504         rc = context_struct_compute_av(scontext, tcontext, tclass,
 505                                        requested, avd);
 506 out:
 507         POLICY_RDUNLOCK;
 508         return rc;
 509 }
 510
 511 /*
 512  * Write the security context string representation of
 513  * the context structure `context' into a dynamically
 514  * allocated string of the correct size.  Set `*scontext'
 515  * to point to this string and set `*scontext_len' to
 516  * the length of the string.
 517  */
 518 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
 519 {
 520         char *scontextp;
 521
 522         *scontext = NULL;
 523         *scontext_len = 0;
 524
 525         /* Compute the size of the context. */
 526         *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
 527         *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
 528         *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
 529         *scontext_len += mls_compute_context_len(context);
 530
 531         /* Allocate space for the context; caller must free this space. */
 532         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
 533         if (!scontextp) {
 534                 return -ENOMEM;
 535         }
 536         *scontext = scontextp;
 537
 538         /*
 539          * Copy the user name, role name and type name into the context.
 540          */
 541         sprintf(scontextp, "%s:%s:%s",
 542                 policydb.p_user_val_to_name[context->user - 1],
 543                 policydb.p_role_val_to_name[context->role - 1],
 544                 policydb.p_type_val_to_name[context->type - 1]);
 545         scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
 546                      1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
 547                      1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
 548
 549         mls_sid_to_context(context, &scontextp);
 550
 551         *scontextp = 0;
 552
 553         return 0;
 554 }
 555
 556 #include "initial_sid_to_string.h"
 557
 558 /**
 559  * security_sid_to_context - Obtain a context for a given SID.
 560  * @sid: security identifier, SID
 561  * @scontext: security context
 562  * @scontext_len: length in bytes
 563  *
 564  * Write the string representation of the context associated with @sid
 565  * into a dynamically allocated string of the correct size.  Set @scontext
 566  * to point to this string and set @scontext_len to the length of the string.
 567  */
 568 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
 569 {
 570         struct context *context;
 571         int rc = 0;
 572
 573         if (!ss_initialized) {
 574                 if (sid <= SECINITSID_NUM) {
 575                         char *scontextp;
 576
 577                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
 578                         scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
 579                         strcpy(scontextp, initial_sid_to_string[sid]);
 580                         *scontext = scontextp;
 581                         goto out;
 582                 }
 583                 printk(KERN_ERR "security_sid_to_context:  called before initial "
 584                        "load_policy on unknown SID %d\n", sid);
 585                 rc = -EINVAL;
 586                 goto out;
 587         }
 588         POLICY_RDLOCK;
 589         context = sidtab_search(&sidtab, sid);
 590         if (!context) {
 591                 printk(KERN_ERR "security_sid_to_context:  unrecognized SID "
 592                        "%d\n", sid);
 593                 rc = -EINVAL;
 594                 goto out_unlock;
 595         }
 596         rc = context_struct_to_string(context, scontext, scontext_len);
 597 out_unlock:
 598         POLICY_RDUNLOCK;
 599 out:
 600         return rc;
 601
 602 }
 603
 604 /**
 605  * security_context_to_sid - Obtain a SID for a given security context.
 606  * @scontext: security context
 607  * @scontext_len: length in bytes
 608  * @sid: security identifier, SID
 609  *
 610  * Obtains a SID associated with the security context that
 611  * has the string representation specified by @scontext.
 612  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 613  * memory is available, or 0 on success.
 614  */
 615 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
 616 {
 617         char *scontext2;
 618         struct context context;
 619         struct role_datum *role;
 620         struct type_datum *typdatum;
 621         struct user_datum *usrdatum;
 622         char *scontextp, *p, oldc;
 623         int rc = 0;
 624
 625         if (!ss_initialized) {
 626                 int i;
 627
 628                 for (i = 1; i < SECINITSID_NUM; i++) {
 629                         if (!strcmp(initial_sid_to_string[i], scontext)) {
 630                                 *sid = i;
 631                                 goto out;
 632                         }
 633                 }
 634                 *sid = SECINITSID_KERNEL;
 635                 goto out;
 636         }
 637         *sid = SECSID_NULL;
 638
 639         /* Copy the string so that we can modify the copy as we parse it.
 640            The string should already by null terminated, but we append a
 641            null suffix to the copy to avoid problems with the existing
 642            attr package, which doesn't view the null terminator as part
 643            of the attribute value. */
 644         scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
 645         if (!scontext2) {
 646                 rc = -ENOMEM;
 647                 goto out;
 648         }
 649         memcpy(scontext2, scontext, scontext_len);
 650         scontext2[scontext_len] = 0;
 651
 652         context_init(&context);
 653         *sid = SECSID_NULL;
 654
 655         POLICY_RDLOCK;
 656
 657         /* Parse the security context. */
 658
 659         rc = -EINVAL;
 660         scontextp = (char *) scontext2;
 661
 662         /* Extract the user. */
 663         p = scontextp;
 664         while (*p && *p != ':')
 665                 p++;
 666
 667         if (*p == 0)
 668                 goto out_unlock;
 669
 670         *p++ = 0;
 671
 672         usrdatum = hashtab_search(policydb.p_users.table, scontextp);
 673         if (!usrdatum)
 674                 goto out_unlock;
 675
 676         context.user = usrdatum->value;
 677
 678         /* Extract role. */
 679         scontextp = p;
 680         while (*p && *p != ':')
 681                 p++;
 682
 683         if (*p == 0)
 684                 goto out_unlock;
 685
 686         *p++ = 0;
 687
 688         role = hashtab_search(policydb.p_roles.table, scontextp);
 689         if (!role)
 690                 goto out_unlock;
 691         context.role = role->value;
 692
 693         /* Extract type. */
 694         scontextp = p;
 695         while (*p && *p != ':')
 696                 p++;
 697         oldc = *p;
 698         *p++ = 0;
 699
 700         typdatum = hashtab_search(policydb.p_types.table, scontextp);
 701         if (!typdatum)
 702                 goto out_unlock;
 703
 704         context.type = typdatum->value;
 705
 706         rc = mls_context_to_sid(oldc, &p, &context);
 707         if (rc)
 708                 goto out_unlock;
 709
 710         if ((p - scontext2) < scontext_len) {
 711                 rc = -EINVAL;
 712                 goto out_unlock;
 713         }
 714
 715         /* Check the validity of the new context. */
 716         if (!policydb_context_isvalid(&policydb, &context)) {
 717                 rc = -EINVAL;
 718                 goto out_unlock;
 719         }
 720         /* Obtain the new sid. */
 721         rc = sidtab_context_to_sid(&sidtab, &context, sid);
 722 out_unlock:
 723         POLICY_RDUNLOCK;
 724         context_destroy(&context);
 725         kfree(scontext2);
 726 out:
 727         return rc;
 728 }
 729
 730 static int compute_sid_handle_invalid_context(
 731         struct context *scontext,
 732         struct context *tcontext,
 733         u16 tclass,
 734         struct context *newcontext)
 735 {
 736         char *s = NULL, *t = NULL, *n = NULL;
 737         u32 slen, tlen, nlen;
 738
 739         if (context_struct_to_string(scontext, &s, &slen) < 0)
 740                 goto out;
 741         if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 742                 goto out;
 743         if (context_struct_to_string(newcontext, &n, &nlen) < 0)
 744                 goto out;
 745         audit_log(current->audit_context,
 746                   "security_compute_sid:  invalid context %s"
 747                   " for scontext=%s"
 748                   " tcontext=%s"
 749                   " tclass=%s",
 750                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
 751 out:
 752         kfree(s);
 753         kfree(t);
 754         kfree(n);
 755         if (!selinux_enforcing)
 756                 return 0;
 757         return -EACCES;
 758 }
 759
 760 static int security_compute_sid(u32 ssid,
 761                                 u32 tsid,
 762                                 u16 tclass,
 763                                 u32 specified,
 764                                 u32 *out_sid)
 765 {
 766         struct context *scontext = NULL, *tcontext = NULL, newcontext;
 767         struct role_trans *roletr = NULL;
 768         struct avtab_key avkey;
 769         struct avtab_datum *avdatum;
 770         struct avtab_node *node;
 771         unsigned int type_change = 0;
 772         int rc = 0;
 773
 774         if (!ss_initialized) {
 775                 switch (tclass) {
 776                 case SECCLASS_PROCESS:
 777                         *out_sid = ssid;
 778                         break;
 779                 default:
 780                         *out_sid = tsid;
 781                         break;
 782                 }
 783                 goto out;
 784         }
 785
 786         POLICY_RDLOCK;
 787
 788         scontext = sidtab_search(&sidtab, ssid);
 789         if (!scontext) {
 790                 printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
 791                        ssid);
 792                 rc = -EINVAL;
 793                 goto out_unlock;
 794         }
 795         tcontext = sidtab_search(&sidtab, tsid);
 796         if (!tcontext) {
 797                 printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
 798                        tsid);
 799                 rc = -EINVAL;
 800                 goto out_unlock;
 801         }
 802
 803         context_init(&newcontext);
 804
 805         /* Set the user identity. */
 806         switch (specified) {
 807         case AVTAB_TRANSITION:
 808         case AVTAB_CHANGE:
 809                 /* Use the process user identity. */
 810                 newcontext.user = scontext->user;
 811                 break;
 812         case AVTAB_MEMBER:
 813                 /* Use the related object owner. */
 814                 newcontext.user = tcontext->user;
 815                 break;
 816         }
 817
 818         /* Set the role and type to default values. */
 819         switch (tclass) {
 820         case SECCLASS_PROCESS:
 821                 /* Use the current role and type of process. */
 822                 newcontext.role = scontext->role;
 823                 newcontext.type = scontext->type;
 824                 break;
 825         default:
 826                 /* Use the well-defined object role. */
 827                 newcontext.role = OBJECT_R_VAL;
 828                 /* Use the type of the related object. */
 829                 newcontext.type = tcontext->type;
 830         }
 831
 832         /* Look for a type transition/member/change rule. */
 833         avkey.source_type = scontext->type;
 834         avkey.target_type = tcontext->type;
 835         avkey.target_class = tclass;
 836         avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_TYPE);
 837
 838         /* If no permanent rule, also check for enabled conditional rules */
 839         if(!avdatum) {
 840                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey, specified);
 841                 for (; node != NULL; node = avtab_search_node_next(node, specified)) {
 842                         if (node->datum.specified & AVTAB_ENABLED) {
 843                                 avdatum = &node->datum;
 844                                 break;
 845                         }
 846                 }
 847         }
 848
 849         type_change = (avdatum && (avdatum->specified & specified));
 850         if (type_change) {
 851                 /* Use the type from the type transition/member/change rule. */
 852                 switch (specified) {
 853                 case AVTAB_TRANSITION:
 854                         newcontext.type = avtab_transition(avdatum);
 855                         break;
 856                 case AVTAB_MEMBER:
 857                         newcontext.type = avtab_member(avdatum);
 858                         break;
 859                 case AVTAB_CHANGE:
 860                         newcontext.type = avtab_change(avdatum);
 861                         break;
 862                 }
 863         }
 864
 865         /* Check for class-specific changes. */
 866         switch (tclass) {
 867         case SECCLASS_PROCESS:
 868                 if (specified & AVTAB_TRANSITION) {
 869                         /* Look for a role transition rule. */
 870                         for (roletr = policydb.role_tr; roletr;
 871                              roletr = roletr->next) {
 872                                 if (roletr->role == scontext->role &&
 873                                     roletr->type == tcontext->type) {
 874                                         /* Use the role transition rule. */
 875                                         newcontext.role = roletr->new_role;
 876                                         break;
 877                                 }
 878                         }
 879                 }
 880                 break;
 881         default:
 882                 break;
 883         }
 884
 885         /* Set the MLS attributes.
 886            This is done last because it may allocate memory. */
 887         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
 888         if (rc)
 889                 goto out_unlock;
 890
 891         /* Check the validity of the context. */
 892         if (!policydb_context_isvalid(&policydb, &newcontext)) {
 893                 rc = compute_sid_handle_invalid_context(scontext,
 894                                                         tcontext,
 895                                                         tclass,
 896                                                         &newcontext);
 897                 if (rc)
 898                         goto out_unlock;
 899         }
 900         /* Obtain the sid for the context. */
 901         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
 902 out_unlock:
 903         POLICY_RDUNLOCK;
 904         context_destroy(&newcontext);
 905 out:
 906         return rc;
 907 }
 908
 909 /**
 910  * security_transition_sid - Compute the SID for a new subject/object.
 911  * @ssid: source security identifier
 912  * @tsid: target security identifier
 913  * @tclass: target security class
 914  * @out_sid: security identifier for new subject/object
 915  *
 916  * Compute a SID to use for labeling a new subject or object in the
 917  * class @tclass based on a SID pair (@ssid, @tsid).
 918  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 919  * if insufficient memory is available, or %0 if the new SID was
 920  * computed successfully.
 921  */
 922 int security_transition_sid(u32 ssid,
 923                             u32 tsid,
 924                             u16 tclass,
 925                             u32 *out_sid)
 926 {
 927         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
 928 }
 929
 930 /**
 931  * security_member_sid - Compute the SID for member selection.
 932  * @ssid: source security identifier
 933  * @tsid: target security identifier
 934  * @tclass: target security class
 935  * @out_sid: security identifier for selected member
 936  *
 937  * Compute a SID to use when selecting a member of a polyinstantiated
 938  * object of class @tclass based on a SID pair (@ssid, @tsid).
 939  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 940  * if insufficient memory is available, or %0 if the SID was
 941  * computed successfully.
 942  */
 943 int security_member_sid(u32 ssid,
 944                         u32 tsid,
 945                         u16 tclass,
 946                         u32 *out_sid)
 947 {
 948         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
 949 }
 950
 951 /**
 952  * security_change_sid - Compute the SID for object relabeling.
 953  * @ssid: source security identifier
 954  * @tsid: target security identifier
 955  * @tclass: target security class
 956  * @out_sid: security identifier for selected member
 957  *
 958  * Compute a SID to use for relabeling an object of class @tclass
 959  * based on a SID pair (@ssid, @tsid).
 960  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
 961  * if insufficient memory is available, or %0 if the SID was
 962  * computed successfully.
 963  */
 964 int security_change_sid(u32 ssid,
 965                         u32 tsid,
 966                         u16 tclass,
 967                         u32 *out_sid)
 968 {
 969         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
 970 }
 971
 972 /*
 973  * Verify that each permission that is defined under the
 974  * existing policy is still defined with the same value
 975  * in the new policy.
 976  */
 977 static int validate_perm(void *key, void *datum, void *p)
 978 {
 979         struct hashtab *h;
 980         struct perm_datum *perdatum, *perdatum2;
 981         int rc = 0;
 982
 983
 984         h = p;
 985         perdatum = datum;
 986
 987         perdatum2 = hashtab_search(h, key);
 988         if (!perdatum2) {
 989                 printk(KERN_ERR "security:  permission %s disappeared",
 990                        (char *)key);
 991                 rc = -ENOENT;
 992                 goto out;
 993         }
 994         if (perdatum->value != perdatum2->value) {
 995                 printk(KERN_ERR "security:  the value of permission %s changed",
 996                        (char *)key);
 997                 rc = -EINVAL;
 998         }
 999 out:
1000         return rc;
1001 }
1002
1003 /*
1004  * Verify that each class that is defined under the
1005  * existing policy is still defined with the same
1006  * attributes in the new policy.
1007  */
1008 static int validate_class(void *key, void *datum, void *p)
1009 {
1010         struct policydb *newp;
1011         struct class_datum *cladatum, *cladatum2;
1012         int rc;
1013
1014         newp = p;
1015         cladatum = datum;
1016
1017         cladatum2 = hashtab_search(newp->p_classes.table, key);
1018         if (!cladatum2) {
1019                 printk(KERN_ERR "security:  class %s disappeared\n",
1020                        (char *)key);
1021                 rc = -ENOENT;
1022                 goto out;
1023         }
1024         if (cladatum->value != cladatum2->value) {
1025                 printk(KERN_ERR "security:  the value of class %s changed\n",
1026                        (char *)key);
1027                 rc = -EINVAL;
1028                 goto out;
1029         }
1030         if ((cladatum->comdatum && !cladatum2->comdatum) ||
1031             (!cladatum->comdatum && cladatum2->comdatum)) {
1032                 printk(KERN_ERR "security:  the inherits clause for the access "
1033                        "vector definition for class %s changed\n", (char *)key);
1034                 rc = -EINVAL;
1035                 goto out;
1036         }
1037         if (cladatum->comdatum) {
1038                 rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm,
1039                                  cladatum2->comdatum->permissions.table);
1040                 if (rc) {
1041                         printk(" in the access vector definition for class "
1042                                "%s\n", (char *)key);
1043                         goto out;
1044                 }
1045         }
1046         rc = hashtab_map(cladatum->permissions.table, validate_perm,
1047                          cladatum2->permissions.table);
1048         if (rc)
1049                 printk(" in access vector definition for class %s\n",
1050                        (char *)key);
1051 out:
1052         return rc;
1053 }
1054
1055 /* Clone the SID into the new SID table. */
1056 static int clone_sid(u32 sid,
1057                      struct context *context,
1058                      void *arg)
1059 {
1060         struct sidtab *s = arg;
1061
1062         return sidtab_insert(s, sid, context);
1063 }
1064
1065 static inline int convert_context_handle_invalid_context(struct context *context)
1066 {
1067         int rc = 0;
1068
1069         if (selinux_enforcing) {
1070                 rc = -EINVAL;
1071         } else {
1072                 char *s;
1073                 u32 len;
1074
1075                 context_struct_to_string(context, &s, &len);
1076                 printk(KERN_ERR "security:  context %s is invalid\n", s);
1077                 kfree(s);
1078         }
1079         return rc;
1080 }
1081
1082 struct convert_context_args {
1083         struct policydb *oldp;
1084         struct policydb *newp;
1085 };
1086
1087 /*
1088  * Convert the values in the security context
1089  * structure `c' from the values specified
1090  * in the policy `p->oldp' to the values specified
1091  * in the policy `p->newp'.  Verify that the
1092  * context is valid under the new policy.
1093  */
1094 static int convert_context(u32 key,
1095                            struct context *c,
1096                            void *p)
1097 {
1098         struct convert_context_args *args;
1099         struct context oldc;
1100         struct role_datum *role;
1101         struct type_datum *typdatum;
1102         struct user_datum *usrdatum;
1103         char *s;
1104         u32 len;
1105         int rc;
1106
1107         args = p;
1108
1109         rc = context_cpy(&oldc, c);
1110         if (rc)
1111                 goto out;
1112
1113         rc = -EINVAL;
1114
1115         /* Convert the user. */
1116         usrdatum = hashtab_search(args->newp->p_users.table,
1117                                   args->oldp->p_user_val_to_name[c->user - 1]);
1118         if (!usrdatum) {
1119                 goto bad;
1120         }
1121         c->user = usrdatum->value;
1122
1123         /* Convert the role. */
1124         role = hashtab_search(args->newp->p_roles.table,
1125                               args->oldp->p_role_val_to_name[c->role - 1]);
1126         if (!role) {
1127                 goto bad;
1128         }
1129         c->role = role->value;
1130
1131         /* Convert the type. */
1132         typdatum = hashtab_search(args->newp->p_types.table,
1133                                   args->oldp->p_type_val_to_name[c->type - 1]);
1134         if (!typdatum) {
1135                 goto bad;
1136         }
1137         c->type = typdatum->value;
1138
1139         rc = mls_convert_context(args->oldp, args->newp, c);
1140         if (rc)
1141                 goto bad;
1142
1143         /* Check the validity of the new context. */
1144         if (!policydb_context_isvalid(args->newp, c)) {
1145                 rc = convert_context_handle_invalid_context(&oldc);
1146                 if (rc)
1147                         goto bad;
1148         }
1149
1150         context_destroy(&oldc);
1151 out:
1152         return rc;
1153 bad:
1154         context_struct_to_string(&oldc, &s, &len);
1155         context_destroy(&oldc);
1156         printk(KERN_ERR "security:  invalidating context %s\n", s);
1157         kfree(s);
1158         goto out;
1159 }
1160
1161 extern void selinux_complete_init(void);
1162
1163 /**
1164  * security_load_policy - Load a security policy configuration.
1165  * @data: binary policy data
1166  * @len: length of data in bytes
1167  *
1168  * Load a new set of security policy configuration data,
1169  * validate it and convert the SID table as necessary.
1170  * This function will flush the access vector cache after
1171  * loading the new policy.
1172  */
1173 int security_load_policy(void *data, size_t len)
1174 {
1175         struct policydb oldpolicydb, newpolicydb;
1176         struct sidtab oldsidtab, newsidtab;
1177         struct convert_context_args args;
1178         u32 seqno;
1179         int rc = 0;
1180         struct policy_file file = { data, len }, *fp = &file;
1181
1182         LOAD_LOCK;
1183
1184         if (!ss_initialized) {
1185                 avtab_cache_init();
1186                 if (policydb_read(&policydb, fp)) {
1187                         LOAD_UNLOCK;
1188                         avtab_cache_destroy();
1189                         return -EINVAL;
1190                 }
1191                 if (policydb_load_isids(&policydb, &sidtab)) {
1192                         LOAD_UNLOCK;
1193                         policydb_destroy(&policydb);
1194                         avtab_cache_destroy();
1195                         return -EINVAL;
1196                 }
1197                 policydb_loaded_version = policydb.policyvers;
1198                 ss_initialized = 1;
1199
1200                 LOAD_UNLOCK;
1201                 selinux_complete_init();
1202                 return 0;
1203         }
1204
1205 #if 0
1206         sidtab_hash_eval(&sidtab, "sids");
1207 #endif
1208
1209         if (policydb_read(&newpolicydb, fp)) {
1210                 LOAD_UNLOCK;
1211                 return -EINVAL;
1212         }
1213
1214         sidtab_init(&newsidtab);
1215
1216         /* Verify that the existing classes did not change. */
1217         if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) {
1218                 printk(KERN_ERR "security:  the definition of an existing "
1219                        "class changed\n");
1220                 rc = -EINVAL;
1221                 goto err;
1222         }
1223
1224         /* Clone the SID table. */
1225         sidtab_shutdown(&sidtab);
1226         if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1227                 rc = -ENOMEM;
1228                 goto err;
1229         }
1230
1231         /* Convert the internal representations of contexts
1232            in the new SID table and remove invalid SIDs. */
1233         args.oldp = &policydb;
1234         args.newp = &newpolicydb;
1235         sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1236
1237         /* Save the old policydb and SID table to free later. */
1238         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1239         sidtab_set(&oldsidtab, &sidtab);
1240
1241         /* Install the new policydb and SID table. */
1242         POLICY_WRLOCK;
1243         memcpy(&policydb, &newpolicydb, sizeof policydb);
1244         sidtab_set(&sidtab, &newsidtab);
1245         seqno = ++latest_granting;
1246         policydb_loaded_version = policydb.policyvers;
1247         POLICY_WRUNLOCK;
1248         LOAD_UNLOCK;
1249
1250         /* Free the old policydb and SID table. */
1251         policydb_destroy(&oldpolicydb);
1252         sidtab_destroy(&oldsidtab);
1253
1254         avc_ss_reset(seqno);
1255         selnl_notify_policyload(seqno);
1256
1257         return 0;
1258
1259 err:
1260         LOAD_UNLOCK;
1261         sidtab_destroy(&newsidtab);
1262         policydb_destroy(&newpolicydb);
1263         return rc;
1264
1265 }
1266
1267 /**
1268  * security_port_sid - Obtain the SID for a port.
1269  * @domain: communication domain aka address family
1270  * @type: socket type
1271  * @protocol: protocol number
1272  * @port: port number
1273  * @out_sid: security identifier
1274  */
1275 int security_port_sid(u16 domain,
1276                       u16 type,
1277                       u8 protocol,
1278                       u16 port,
1279                       u32 *out_sid)
1280 {
1281         struct ocontext *c;
1282         int rc = 0;
1283
1284         POLICY_RDLOCK;
1285
1286         c = policydb.ocontexts[OCON_PORT];
1287         while (c) {
1288                 if (c->u.port.protocol == protocol &&
1289                     c->u.port.low_port <= port &&
1290                     c->u.port.high_port >= port)
1291                         break;
1292                 c = c->next;
1293         }
1294
1295         if (c) {
1296                 if (!c->sid[0]) {
1297                         rc = sidtab_context_to_sid(&sidtab,
1298                                                    &c->context[0],
1299                                                    &c->sid[0]);
1300                         if (rc)
1301                                 goto out;
1302                 }
1303                 *out_sid = c->sid[0];
1304         } else {
1305                 *out_sid = SECINITSID_PORT;
1306         }
1307
1308 out:
1309         POLICY_RDUNLOCK;
1310         return rc;
1311 }
1312
1313 /**
1314  * security_netif_sid - Obtain the SID for a network interface.
1315  * @name: interface name
1316  * @if_sid: interface SID
1317  * @msg_sid: default SID for received packets
1318  */
1319 int security_netif_sid(char *name,
1320                        u32 *if_sid,
1321                        u32 *msg_sid)
1322 {
1323         int rc = 0;
1324         struct ocontext *c;
1325
1326         POLICY_RDLOCK;
1327
1328         c = policydb.ocontexts[OCON_NETIF];
1329         while (c) {
1330                 if (strcmp(name, c->u.name) == 0)
1331                         break;
1332                 c = c->next;
1333         }
1334
1335         if (c) {
1336                 if (!c->sid[0] || !c->sid[1]) {
1337                         rc = sidtab_context_to_sid(&sidtab,
1338                                                   &c->context[0],
1339                                                   &c->sid[0]);
1340                         if (rc)
1341                                 goto out;
1342                         rc = sidtab_context_to_sid(&sidtab,
1343                                                    &c->context[1],
1344                                                    &c->sid[1]);
1345                         if (rc)
1346                                 goto out;
1347                 }
1348                 *if_sid = c->sid[0];
1349                 *msg_sid = c->sid[1];
1350         } else {
1351                 *if_sid = SECINITSID_NETIF;
1352                 *msg_sid = SECINITSID_NETMSG;
1353         }
1354
1355 out:
1356         POLICY_RDUNLOCK;
1357         return rc;
1358 }
1359
1360 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1361 {
1362         int i, fail = 0;
1363
1364         for(i = 0; i < 4; i++)
1365                 if(addr[i] != (input[i] & mask[i])) {
1366                         fail = 1;
1367                         break;
1368                 }
1369
1370         return !fail;
1371 }
1372
1373 /**
1374  * security_node_sid - Obtain the SID for a node (host).
1375  * @domain: communication domain aka address family
1376  * @addrp: address
1377  * @addrlen: address length in bytes
1378  * @out_sid: security identifier
1379  */
1380 int security_node_sid(u16 domain,
1381                       void *addrp,
1382                       u32 addrlen,
1383                       u32 *out_sid)
1384 {
1385         int rc = 0;
1386         struct ocontext *c;
1387
1388         POLICY_RDLOCK;
1389
1390         switch (domain) {
1391         case AF_INET: {
1392                 u32 addr;
1393
1394                 if (addrlen != sizeof(u32)) {
1395                         rc = -EINVAL;
1396                         goto out;
1397                 }
1398
1399                 addr = *((u32 *)addrp);
1400
1401                 c = policydb.ocontexts[OCON_NODE];
1402                 while (c) {
1403                         if (c->u.node.addr == (addr & c->u.node.mask))
1404                                 break;
1405                         c = c->next;
1406                 }
1407                 break;
1408         }
1409
1410         case AF_INET6:
1411                 if (addrlen != sizeof(u64) * 2) {
1412                         rc = -EINVAL;
1413                         goto out;
1414                 }
1415                 c = policydb.ocontexts[OCON_NODE6];
1416                 while (c) {
1417                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1418                                                 c->u.node6.mask))
1419                                 break;
1420                         c = c->next;
1421                 }
1422                 break;
1423
1424         default:
1425                 *out_sid = SECINITSID_NODE;
1426                 goto out;
1427         }
1428
1429         if (c) {
1430                 if (!c->sid[0]) {
1431                         rc = sidtab_context_to_sid(&sidtab,
1432                                                    &c->context[0],
1433                                                    &c->sid[0]);
1434                         if (rc)
1435                                 goto out;
1436                 }
1437                 *out_sid = c->sid[0];
1438         } else {
1439                 *out_sid = SECINITSID_NODE;
1440         }
1441
1442 out:
1443         POLICY_RDUNLOCK;
1444         return rc;
1445 }
1446
1447 #define SIDS_NEL 25
1448
1449 /**
1450  * security_get_user_sids - Obtain reachable SIDs for a user.
1451  * @fromsid: starting SID
1452  * @username: username
1453  * @sids: array of reachable SIDs for user
1454  * @nel: number of elements in @sids
1455  *
1456  * Generate the set of SIDs for legal security contexts
1457  * for a given user that can be reached by @fromsid.
1458  * Set *@sids to point to a dynamically allocated
1459  * array containing the set of SIDs.  Set *@nel to the
1460  * number of elements in the array.
1461  */
1462
1463 int security_get_user_sids(u32 fromsid,
1464                            char *username,
1465                            u32 **sids,
1466                            u32 *nel)
1467 {
1468         struct context *fromcon, usercon;
1469         u32 *mysids, *mysids2, sid;
1470         u32 mynel = 0, maxnel = SIDS_NEL;
1471         struct user_datum *user;
1472         struct role_datum *role;
1473         struct av_decision avd;
1474         int rc = 0, i, j;
1475
1476         if (!ss_initialized) {
1477                 *sids = NULL;
1478                 *nel = 0;
1479                 goto out;
1480         }
1481
1482         POLICY_RDLOCK;
1483
1484         fromcon = sidtab_search(&sidtab, fromsid);
1485         if (!fromcon) {
1486                 rc = -EINVAL;
1487                 goto out_unlock;
1488         }
1489
1490         user = hashtab_search(policydb.p_users.table, username);
1491         if (!user) {
1492                 rc = -EINVAL;
1493                 goto out_unlock;
1494         }
1495         usercon.user = user->value;
1496
1497         mysids = kmalloc(maxnel*sizeof(*mysids), GFP_ATOMIC);
1498         if (!mysids) {
1499                 rc = -ENOMEM;
1500                 goto out_unlock;
1501         }
1502         memset(mysids, 0, maxnel*sizeof(*mysids));
1503
1504         for (i = ebitmap_startbit(&user->roles); i < ebitmap_length(&user->roles); i++) {
1505                 if (!ebitmap_get_bit(&user->roles, i))
1506                         continue;
1507                 role = policydb.role_val_to_struct[i];
1508                 usercon.role = i+1;
1509                 for (j = ebitmap_startbit(&role->types); j < ebitmap_length(&role->types); j++) {
1510                         if (!ebitmap_get_bit(&role->types, j))
1511                                 continue;
1512                         usercon.type = j+1;
1513
1514                         if (mls_setup_user_range(fromcon, user, &usercon))
1515                                 continue;
1516
1517                         rc = context_struct_compute_av(fromcon, &usercon,
1518                                                        SECCLASS_PROCESS,
1519                                                        PROCESS__TRANSITION,
1520                                                        &avd);
1521                         if (rc ||  !(avd.allowed & PROCESS__TRANSITION))
1522                                 continue;
1523                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1524                         if (rc) {
1525                                 kfree(mysids);
1526                                 goto out_unlock;
1527                         }
1528                         if (mynel < maxnel) {
1529                                 mysids[mynel++] = sid;
1530                         } else {
1531                                 maxnel += SIDS_NEL;
1532                                 mysids2 = kmalloc(maxnel*sizeof(*mysids2), GFP_ATOMIC);
1533                                 if (!mysids2) {
1534                                         rc = -ENOMEM;
1535                                         kfree(mysids);
1536                                         goto out_unlock;
1537                                 }
1538                                 memset(mysids2, 0, maxnel*sizeof(*mysids2));
1539                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1540                                 kfree(mysids);
1541                                 mysids = mysids2;
1542                                 mysids[mynel++] = sid;
1543                         }
1544                 }
1545         }
1546
1547         *sids = mysids;
1548         *nel = mynel;
1549
1550 out_unlock:
1551         POLICY_RDUNLOCK;
1552 out:
1553         return rc;
1554 }
1555
1556 /**
1557  * security_genfs_sid - Obtain a SID for a file in a filesystem
1558  * @fstype: filesystem type
1559  * @path: path from root of mount
1560  * @sclass: file security class
1561  * @sid: SID for path
1562  *
1563  * Obtain a SID to use for a file in a filesystem that
1564  * cannot support xattr or use a fixed labeling behavior like
1565  * transition SIDs or task SIDs.
1566  */
1567 int security_genfs_sid(const char *fstype,
1568                        char *path,
1569                        u16 sclass,
1570                        u32 *sid)
1571 {
1572         int len;
1573         struct genfs *genfs;
1574         struct ocontext *c;
1575         int rc = 0, cmp = 0;
1576
1577         POLICY_RDLOCK;
1578
1579         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1580                 cmp = strcmp(fstype, genfs->fstype);
1581                 if (cmp <= 0)
1582                         break;
1583         }
1584
1585         if (!genfs || cmp) {
1586                 *sid = SECINITSID_UNLABELED;
1587                 rc = -ENOENT;
1588                 goto out;
1589         }
1590
1591         for (c = genfs->head; c; c = c->next) {
1592                 len = strlen(c->u.name);
1593                 if ((!c->v.sclass || sclass == c->v.sclass) &&
1594                     (strncmp(c->u.name, path, len) == 0))
1595                         break;
1596         }
1597
1598         if (!c) {
1599                 *sid = SECINITSID_UNLABELED;
1600                 rc = -ENOENT;
1601                 goto out;
1602         }
1603
1604         if (!c->sid[0]) {
1605                 rc = sidtab_context_to_sid(&sidtab,
1606                                            &c->context[0],
1607                                            &c->sid[0]);
1608                 if (rc)
1609                         goto out;
1610         }
1611
1612         *sid = c->sid[0];
1613 out:
1614         POLICY_RDUNLOCK;
1615         return rc;
1616 }
1617
1618 /**
1619  * security_fs_use - Determine how to handle labeling for a filesystem.
1620  * @fstype: filesystem type
1621  * @behavior: labeling behavior
1622  * @sid: SID for filesystem (superblock)
1623  */
1624 int security_fs_use(
1625         const char *fstype,
1626         unsigned int *behavior,
1627         u32 *sid)
1628 {
1629         int rc = 0;
1630         struct ocontext *c;
1631
1632         POLICY_RDLOCK;
1633
1634         c = policydb.ocontexts[OCON_FSUSE];
1635         while (c) {
1636                 if (strcmp(fstype, c->u.name) == 0)
1637                         break;
1638                 c = c->next;
1639         }
1640
1641         if (c) {
1642                 *behavior = c->v.behavior;
1643                 if (!c->sid[0]) {
1644                         rc = sidtab_context_to_sid(&sidtab,
1645                                                    &c->context[0],
1646                                                    &c->sid[0]);
1647                         if (rc)
1648                                 goto out;
1649                 }
1650                 *sid = c->sid[0];
1651         } else {
1652                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1653                 if (rc) {
1654                         *behavior = SECURITY_FS_USE_NONE;
1655                         rc = 0;
1656                 } else {
1657                         *behavior = SECURITY_FS_USE_GENFS;
1658                 }
1659         }
1660
1661 out:
1662         POLICY_RDUNLOCK;
1663         return rc;
1664 }
1665
1666 int security_get_bools(int *len, char ***names, int **values)
1667 {
1668         int i, rc = -ENOMEM;
1669
1670         POLICY_RDLOCK;
1671         *names = NULL;
1672         *values = NULL;
1673
1674         *len = policydb.p_bools.nprim;
1675         if (!*len) {
1676                 rc = 0;
1677                 goto out;
1678         }
1679
1680         *names = (char**)kmalloc(sizeof(char*) * *len, GFP_ATOMIC);
1681         if (!*names)
1682                 goto err;
1683         memset(*names, 0, sizeof(char*) * *len);
1684
1685         *values = (int*)kmalloc(sizeof(int) * *len, GFP_ATOMIC);
1686         if (!*values)
1687                 goto err;
1688
1689         for (i = 0; i < *len; i++) {
1690                 size_t name_len;
1691                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
1692                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1693                 (*names)[i] = (char*)kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1694                 if (!(*names)[i])
1695                         goto err;
1696                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1697                 (*names)[i][name_len - 1] = 0;
1698         }
1699         rc = 0;
1700 out:
1701         POLICY_RDUNLOCK;
1702         return rc;
1703 err:
1704         if (*names) {
1705                 for (i = 0; i < *len; i++)
1706                         if ((*names)[i])
1707                                 kfree((*names)[i]);
1708         }
1709         if (*values)
1710                 kfree(*values);
1711         goto out;
1712 }
1713
1714
1715 int security_set_bools(int len, int *values)
1716 {
1717         int i, rc = 0;
1718         int lenp, seqno = 0;
1719         struct cond_node *cur;
1720
1721         POLICY_WRLOCK;
1722
1723         lenp = policydb.p_bools.nprim;
1724         if (len != lenp) {
1725                 rc = -EFAULT;
1726                 goto out;
1727         }
1728
1729         printk(KERN_INFO "security: committed booleans { ");
1730         for (i = 0; i < len; i++) {
1731                 if (values[i]) {
1732                         policydb.bool_val_to_struct[i]->state = 1;
1733                 } else {
1734                         policydb.bool_val_to_struct[i]->state = 0;
1735                 }
1736                 if (i != 0)
1737                         printk(", ");
1738                 printk("%s:%d", policydb.p_bool_val_to_name[i],
1739                        policydb.bool_val_to_struct[i]->state);
1740         }
1741         printk(" }\n");
1742
1743         for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1744                 rc = evaluate_cond_node(&policydb, cur);
1745                 if (rc)
1746                         goto out;
1747         }
1748
1749         seqno = ++latest_granting;
1750
1751 out:
1752         POLICY_WRUNLOCK;
1753         if (!rc) {
1754                 avc_ss_reset(seqno);
1755                 selnl_notify_policyload(seqno);
1756         }
1757         return rc;
1758 }
1759
1760 int security_get_bool_value(int bool)
1761 {
1762         int rc = 0;
1763         int len;
1764
1765         POLICY_RDLOCK;
1766
1767         len = policydb.p_bools.nprim;
1768         if (bool >= len) {
1769                 rc = -EFAULT;
1770                 goto out;
1771         }
1772
1773         rc = policydb.bool_val_to_struct[bool]->state;
1774 out:
1775         POLICY_RDUNLOCK;
1776         return rc;
1777 }