kernel/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@paul-moore.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  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <guido@trentalancia.com>
  30  *
  31  *  Added support for runtime switching of the policy type
  32  *
  33  * Copyright (C) 2008, 2009 NEC Corporation
  34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  38  *      This program is free software; you can redistribute it and/or modify
  39  *      it under the terms of the GNU General Public License as published by
  40  *      the Free Software Foundation, version 2.
  41  */
  42 #include <linux/kernel.h>
  43 #include <linux/slab.h>
  44 #include <linux/string.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/errno.h>
  48 #include <linux/in.h>
  49 #include <linux/sched.h>
  50 #include <linux/audit.h>
  51 #include <linux/mutex.h>
  52 #include <linux/selinux.h>
  53 #include <linux/flex_array.h>
  54 #include <linux/vmalloc.h>
  55 #include <net/netlabel.h>
  56
  57 #include "flask.h"
  58 #include "avc.h"
  59 #include "avc_ss.h"
  60 #include "security.h"
  61 #include "context.h"
  62 #include "policydb.h"
  63 #include "sidtab.h"
  64 #include "services.h"
  65 #include "conditional.h"
  66 #include "mls.h"
  67 #include "objsec.h"
  68 #include "netlabel.h"
  69 #include "xfrm.h"
  70 #include "ebitmap.h"
  71 #include "audit.h"
  72
  73 int selinux_policycap_netpeer;
  74 int selinux_policycap_openperm;
  75 int selinux_policycap_alwaysnetwork;
  76
  77 static DEFINE_RWLOCK(policy_rwlock);
  78
  79 static struct sidtab sidtab;
  80 struct policydb policydb;
  81 int ss_initialized;
  82
  83 /*
  84  * The largest sequence number that has been used when
  85  * providing an access decision to the access vector cache.
  86  * The sequence number only changes when a policy change
  87  * occurs.
  88  */
  89 static u32 latest_granting;
  90
  91 /* Forward declaration. */
  92 static int context_struct_to_string(struct context *context, char **scontext,
  93                                     u32 *scontext_len);
  94
  95 static void context_struct_compute_av(struct context *scontext,
  96                                       struct context *tcontext,
  97                                       u16 tclass,
  98                                       struct av_decision *avd);
  99
 100 struct selinux_mapping {
 101         u16 value; /* policy value */
 102         unsigned num_perms;
 103         u32 perms[sizeof(u32) * 8];
 104 };
 105
 106 static struct selinux_mapping *current_mapping;
 107 static u16 current_mapping_size;
 108
 109 static int selinux_set_mapping(struct policydb *pol,
 110                                struct security_class_mapping *map,
 111                                struct selinux_mapping **out_map_p,
 112                                u16 *out_map_size)
 113 {
 114         struct selinux_mapping *out_map = NULL;
 115         size_t size = sizeof(struct selinux_mapping);
 116         u16 i, j;
 117         unsigned k;
 118         bool print_unknown_handle = false;
 119
 120         /* Find number of classes in the input mapping */
 121         if (!map)
 122                 return -EINVAL;
 123         i = 0;
 124         while (map[i].name)
 125                 i++;
 126
 127         /* Allocate space for the class records, plus one for class zero */
 128         out_map = kcalloc(++i, size, GFP_ATOMIC);
 129         if (!out_map)
 130                 return -ENOMEM;
 131
 132         /* Store the raw class and permission values */
 133         j = 0;
 134         while (map[j].name) {
 135                 struct security_class_mapping *p_in = map + (j++);
 136                 struct selinux_mapping *p_out = out_map + j;
 137
 138                 /* An empty class string skips ahead */
 139                 if (!strcmp(p_in->name, "")) {
 140                         p_out->num_perms = 0;
 141                         continue;
 142                 }
 143
 144                 p_out->value = string_to_security_class(pol, p_in->name);
 145                 if (!p_out->value) {
 146                         printk(KERN_INFO
 147                                "SELinux:  Class %s not defined in policy.\n",
 148                                p_in->name);
 149                         if (pol->reject_unknown)
 150                                 goto err;
 151                         p_out->num_perms = 0;
 152                         print_unknown_handle = true;
 153                         continue;
 154                 }
 155
 156                 k = 0;
 157                 while (p_in->perms && p_in->perms[k]) {
 158                         /* An empty permission string skips ahead */
 159                         if (!*p_in->perms[k]) {
 160                                 k++;
 161                                 continue;
 162                         }
 163                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 164                                                             p_in->perms[k]);
 165                         if (!p_out->perms[k]) {
 166                                 printk(KERN_INFO
 167                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 168                                        p_in->perms[k], p_in->name);
 169                                 if (pol->reject_unknown)
 170                                         goto err;
 171                                 print_unknown_handle = true;
 172                         }
 173
 174                         k++;
 175                 }
 176                 p_out->num_perms = k;
 177         }
 178
 179         if (print_unknown_handle)
 180                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 181                        pol->allow_unknown ? "allowed" : "denied");
 182
 183         *out_map_p = out_map;
 184         *out_map_size = i;
 185         return 0;
 186 err:
 187         kfree(out_map);
 188         return -EINVAL;
 189 }
 190
 191 /*
 192  * Get real, policy values from mapped values
 193  */
 194
 195 static u16 unmap_class(u16 tclass)
 196 {
 197         if (tclass < current_mapping_size)
 198                 return current_mapping[tclass].value;
 199
 200         return tclass;
 201 }
 202
 203 /*
 204  * Get kernel value for class from its policy value
 205  */
 206 static u16 map_class(u16 pol_value)
 207 {
 208         u16 i;
 209
 210         for (i = 1; i < current_mapping_size; i++) {
 211                 if (current_mapping[i].value == pol_value)
 212                         return i;
 213         }
 214
 215         return SECCLASS_NULL;
 216 }
 217
 218 static void map_decision(u16 tclass, struct av_decision *avd,
 219                          int allow_unknown)
 220 {
 221         if (tclass < current_mapping_size) {
 222                 unsigned i, n = current_mapping[tclass].num_perms;
 223                 u32 result;
 224
 225                 for (i = 0, result = 0; i < n; i++) {
 226                         if (avd->allowed & current_mapping[tclass].perms[i])
 227                                 result |= 1<<i;
 228                         if (allow_unknown && !current_mapping[tclass].perms[i])
 229                                 result |= 1<<i;
 230                 }
 231                 avd->allowed = result;
 232
 233                 for (i = 0, result = 0; i < n; i++)
 234                         if (avd->auditallow & current_mapping[tclass].perms[i])
 235                                 result |= 1<<i;
 236                 avd->auditallow = result;
 237
 238                 for (i = 0, result = 0; i < n; i++) {
 239                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 240                                 result |= 1<<i;
 241                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 242                                 result |= 1<<i;
 243                 }
 244                 /*
 245                  * In case the kernel has a bug and requests a permission
 246                  * between num_perms and the maximum permission number, we
 247                  * should audit that denial
 248                  */
 249                 for (; i < (sizeof(u32)*8); i++)
 250                         result |= 1<<i;
 251                 avd->auditdeny = result;
 252         }
 253 }
 254
 255 int security_mls_enabled(void)
 256 {
 257         return policydb.mls_enabled;
 258 }
 259
 260 /*
 261  * Return the boolean value of a constraint expression
 262  * when it is applied to the specified source and target
 263  * security contexts.
 264  *
 265  * xcontext is a special beast...  It is used by the validatetrans rules
 266  * only.  For these rules, scontext is the context before the transition,
 267  * tcontext is the context after the transition, and xcontext is the context
 268  * of the process performing the transition.  All other callers of
 269  * constraint_expr_eval should pass in NULL for xcontext.
 270  */
 271 static int constraint_expr_eval(struct context *scontext,
 272                                 struct context *tcontext,
 273                                 struct context *xcontext,
 274                                 struct constraint_expr *cexpr)
 275 {
 276         u32 val1, val2;
 277         struct context *c;
 278         struct role_datum *r1, *r2;
 279         struct mls_level *l1, *l2;
 280         struct constraint_expr *e;
 281         int s[CEXPR_MAXDEPTH];
 282         int sp = -1;
 283
 284         for (e = cexpr; e; e = e->next) {
 285                 switch (e->expr_type) {
 286                 case CEXPR_NOT:
 287                         BUG_ON(sp < 0);
 288                         s[sp] = !s[sp];
 289                         break;
 290                 case CEXPR_AND:
 291                         BUG_ON(sp < 1);
 292                         sp--;
 293                         s[sp] &= s[sp + 1];
 294                         break;
 295                 case CEXPR_OR:
 296                         BUG_ON(sp < 1);
 297                         sp--;
 298                         s[sp] |= s[sp + 1];
 299                         break;
 300                 case CEXPR_ATTR:
 301                         if (sp == (CEXPR_MAXDEPTH - 1))
 302                                 return 0;
 303                         switch (e->attr) {
 304                         case CEXPR_USER:
 305                                 val1 = scontext->user;
 306                                 val2 = tcontext->user;
 307                                 break;
 308                         case CEXPR_TYPE:
 309                                 val1 = scontext->type;
 310                                 val2 = tcontext->type;
 311                                 break;
 312                         case CEXPR_ROLE:
 313                                 val1 = scontext->role;
 314                                 val2 = tcontext->role;
 315                                 r1 = policydb.role_val_to_struct[val1 - 1];
 316                                 r2 = policydb.role_val_to_struct[val2 - 1];
 317                                 switch (e->op) {
 318                                 case CEXPR_DOM:
 319                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 320                                                                   val2 - 1);
 321                                         continue;
 322                                 case CEXPR_DOMBY:
 323                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 324                                                                   val1 - 1);
 325                                         continue;
 326                                 case CEXPR_INCOMP:
 327                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 328                                                                     val2 - 1) &&
 329                                                    !ebitmap_get_bit(&r2->dominates,
 330                                                                     val1 - 1));
 331                                         continue;
 332                                 default:
 333                                         break;
 334                                 }
 335                                 break;
 336                         case CEXPR_L1L2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_L1H2:
 341                                 l1 = &(scontext->range.level[0]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1L2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[0]);
 347                                 goto mls_ops;
 348                         case CEXPR_H1H2:
 349                                 l1 = &(scontext->range.level[1]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L1H1:
 353                                 l1 = &(scontext->range.level[0]);
 354                                 l2 = &(scontext->range.level[1]);
 355                                 goto mls_ops;
 356                         case CEXPR_L2H2:
 357                                 l1 = &(tcontext->range.level[0]);
 358                                 l2 = &(tcontext->range.level[1]);
 359                                 goto mls_ops;
 360 mls_ops:
 361                         switch (e->op) {
 362                         case CEXPR_EQ:
 363                                 s[++sp] = mls_level_eq(l1, l2);
 364                                 continue;
 365                         case CEXPR_NEQ:
 366                                 s[++sp] = !mls_level_eq(l1, l2);
 367                                 continue;
 368                         case CEXPR_DOM:
 369                                 s[++sp] = mls_level_dom(l1, l2);
 370                                 continue;
 371                         case CEXPR_DOMBY:
 372                                 s[++sp] = mls_level_dom(l2, l1);
 373                                 continue;
 374                         case CEXPR_INCOMP:
 375                                 s[++sp] = mls_level_incomp(l2, l1);
 376                                 continue;
 377                         default:
 378                                 BUG();
 379                                 return 0;
 380                         }
 381                         break;
 382                         default:
 383                                 BUG();
 384                                 return 0;
 385                         }
 386
 387                         switch (e->op) {
 388                         case CEXPR_EQ:
 389                                 s[++sp] = (val1 == val2);
 390                                 break;
 391                         case CEXPR_NEQ:
 392                                 s[++sp] = (val1 != val2);
 393                                 break;
 394                         default:
 395                                 BUG();
 396                                 return 0;
 397                         }
 398                         break;
 399                 case CEXPR_NAMES:
 400                         if (sp == (CEXPR_MAXDEPTH-1))
 401                                 return 0;
 402                         c = scontext;
 403                         if (e->attr & CEXPR_TARGET)
 404                                 c = tcontext;
 405                         else if (e->attr & CEXPR_XTARGET) {
 406                                 c = xcontext;
 407                                 if (!c) {
 408                                         BUG();
 409                                         return 0;
 410                                 }
 411                         }
 412                         if (e->attr & CEXPR_USER)
 413                                 val1 = c->user;
 414                         else if (e->attr & CEXPR_ROLE)
 415                                 val1 = c->role;
 416                         else if (e->attr & CEXPR_TYPE)
 417                                 val1 = c->type;
 418                         else {
 419                                 BUG();
 420                                 return 0;
 421                         }
 422
 423                         switch (e->op) {
 424                         case CEXPR_EQ:
 425                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         case CEXPR_NEQ:
 428                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         default:
 431                                 BUG();
 432                                 return 0;
 433                         }
 434                         break;
 435                 default:
 436                         BUG();
 437                         return 0;
 438                 }
 439         }
 440
 441         BUG_ON(sp != 0);
 442         return s[0];
 443 }
 444
 445 /*
 446  * security_dump_masked_av - dumps masked permissions during
 447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 448  */
 449 static int dump_masked_av_helper(void *k, void *d, void *args)
 450 {
 451         struct perm_datum *pdatum = d;
 452         char **permission_names = args;
 453
 454         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 455
 456         permission_names[pdatum->value - 1] = (char *)k;
 457
 458         return 0;
 459 }
 460
 461 static void security_dump_masked_av(struct context *scontext,
 462                                     struct context *tcontext,
 463                                     u16 tclass,
 464                                     u32 permissions,
 465                                     const char *reason)
 466 {
 467         struct common_datum *common_dat;
 468         struct class_datum *tclass_dat;
 469         struct audit_buffer *ab;
 470         char *tclass_name;
 471         char *scontext_name = NULL;
 472         char *tcontext_name = NULL;
 473         char *permission_names[32];
 474         int index;
 475         u32 length;
 476         bool need_comma = false;
 477
 478         if (!permissions)
 479                 return;
 480
 481         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 482         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 483         common_dat = tclass_dat->comdatum;
 484
 485         /* init permission_names */
 486         if (common_dat &&
 487             hashtab_map(common_dat->permissions.table,
 488                         dump_masked_av_helper, permission_names) < 0)
 489                 goto out;
 490
 491         if (hashtab_map(tclass_dat->permissions.table,
 492                         dump_masked_av_helper, permission_names) < 0)
 493                 goto out;
 494
 495         /* get scontext/tcontext in text form */
 496         if (context_struct_to_string(scontext,
 497                                      &scontext_name, &length) < 0)
 498                 goto out;
 499
 500         if (context_struct_to_string(tcontext,
 501                                      &tcontext_name, &length) < 0)
 502                 goto out;
 503
 504         /* audit a message */
 505         ab = audit_log_start(current->audit_context,
 506                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 507         if (!ab)
 508                 goto out;
 509
 510         audit_log_format(ab, "op=security_compute_av reason=%s "
 511                          "scontext=%s tcontext=%s tclass=%s perms=",
 512                          reason, scontext_name, tcontext_name, tclass_name);
 513
 514         for (index = 0; index < 32; index++) {
 515                 u32 mask = (1 << index);
 516
 517                 if ((mask & permissions) == 0)
 518                         continue;
 519
 520                 audit_log_format(ab, "%s%s",
 521                                  need_comma ? "," : "",
 522                                  permission_names[index]
 523                                  ? permission_names[index] : "????");
 524                 need_comma = true;
 525         }
 526         audit_log_end(ab);
 527 out:
 528         /* release scontext/tcontext */
 529         kfree(tcontext_name);
 530         kfree(scontext_name);
 531
 532         return;
 533 }
 534
 535 /*
 536  * security_boundary_permission - drops violated permissions
 537  * on boundary constraint.
 538  */
 539 static void type_attribute_bounds_av(struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 552                                     scontext->type - 1);
 553         BUG_ON(!source);
 554
 555         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 556                                     tcontext->type - 1);
 557         BUG_ON(!target);
 558
 559         if (source->bounds) {
 560                 memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563                 lo_scontext.type = source->bounds;
 564
 565                 context_struct_compute_av(&lo_scontext,
 566                                           tcontext,
 567                                           tclass,
 568                                           &lo_avd);
 569                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 570                         return;         /* no masked permission */
 571                 masked = ~lo_avd.allowed & avd->allowed;
 572         }
 573
 574         if (target->bounds) {
 575                 memset(&lo_avd, 0, sizeof(lo_avd));
 576
 577                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 578                 lo_tcontext.type = target->bounds;
 579
 580                 context_struct_compute_av(scontext,
 581                                           &lo_tcontext,
 582                                           tclass,
 583                                           &lo_avd);
 584                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 585                         return;         /* no masked permission */
 586                 masked = ~lo_avd.allowed & avd->allowed;
 587         }
 588
 589         if (source->bounds && target->bounds) {
 590                 memset(&lo_avd, 0, sizeof(lo_avd));
 591                 /*
 592                  * lo_scontext and lo_tcontext are already
 593                  * set up.
 594                  */
 595
 596                 context_struct_compute_av(&lo_scontext,
 597                                           &lo_tcontext,
 598                                           tclass,
 599                                           &lo_avd);
 600                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 601                         return;         /* no masked permission */
 602                 masked = ~lo_avd.allowed & avd->allowed;
 603         }
 604
 605         if (masked) {
 606                 /* mask violated permissions */
 607                 avd->allowed &= ~masked;
 608
 609                 /* audit masked permissions */
 610                 security_dump_masked_av(scontext, tcontext,
 611                                         tclass, masked, "bounds");
 612         }
 613 }
 614
 615 /*
 616  * Compute access vectors based on a context structure pair for
 617  * the permissions in a particular class.
 618  */
 619 static void context_struct_compute_av(struct context *scontext,
 620                                       struct context *tcontext,
 621                                       u16 tclass,
 622                                       struct av_decision *avd)
 623 {
 624         struct constraint_node *constraint;
 625         struct role_allow *ra;
 626         struct avtab_key avkey;
 627         struct avtab_node *node;
 628         struct class_datum *tclass_datum;
 629         struct ebitmap *sattr, *tattr;
 630         struct ebitmap_node *snode, *tnode;
 631         unsigned int i, j;
 632
 633         avd->allowed = 0;
 634         avd->auditallow = 0;
 635         avd->auditdeny = 0xffffffff;
 636
 637         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 638                 if (printk_ratelimit())
 639                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 640                 return;
 641         }
 642
 643         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 644
 645         /*
 646          * If a specific type enforcement rule was defined for
 647          * this permission check, then use it.
 648          */
 649         avkey.target_class = tclass;
 650         avkey.specified = AVTAB_AV;
 651         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 652         BUG_ON(!sattr);
 653         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 654         BUG_ON(!tattr);
 655         ebitmap_for_each_positive_bit(sattr, snode, i) {
 656                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 657                         avkey.source_type = i + 1;
 658                         avkey.target_type = j + 1;
 659                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 660                              node;
 661                              node = avtab_search_node_next(node, avkey.specified)) {
 662                                 if (node->key.specified == AVTAB_ALLOWED)
 663                                         avd->allowed |= node->datum.data;
 664                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 665                                         avd->auditallow |= node->datum.data;
 666                                 else if (node->key.specified == AVTAB_AUDITDENY)
 667                                         avd->auditdeny &= node->datum.data;
 668                         }
 669
 670                         /* Check conditional av table for additional permissions */
 671                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 672
 673                 }
 674         }
 675
 676         /*
 677          * Remove any permissions prohibited by a constraint (this includes
 678          * the MLS policy).
 679          */
 680         constraint = tclass_datum->constraints;
 681         while (constraint) {
 682                 if ((constraint->permissions & (avd->allowed)) &&
 683                     !constraint_expr_eval(scontext, tcontext, NULL,
 684                                           constraint->expr)) {
 685                         avd->allowed &= ~(constraint->permissions);
 686                 }
 687                 constraint = constraint->next;
 688         }
 689
 690         /*
 691          * If checking process transition permission and the
 692          * role is changing, then check the (current_role, new_role)
 693          * pair.
 694          */
 695         if (tclass == policydb.process_class &&
 696             (avd->allowed & policydb.process_trans_perms) &&
 697             scontext->role != tcontext->role) {
 698                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 699                         if (scontext->role == ra->role &&
 700                             tcontext->role == ra->new_role)
 701                                 break;
 702                 }
 703                 if (!ra)
 704                         avd->allowed &= ~policydb.process_trans_perms;
 705         }
 706
 707         /*
 708          * If the given source and target types have boundary
 709          * constraint, lazy checks have to mask any violated
 710          * permission and notice it to userspace via audit.
 711          */
 712         type_attribute_bounds_av(scontext, tcontext,
 713                                  tclass, avd);
 714 }
 715
 716 static int security_validtrans_handle_fail(struct context *ocontext,
 717                                            struct context *ncontext,
 718                                            struct context *tcontext,
 719                                            u16 tclass)
 720 {
 721         char *o = NULL, *n = NULL, *t = NULL;
 722         u32 olen, nlen, tlen;
 723
 724         if (context_struct_to_string(ocontext, &o, &olen))
 725                 goto out;
 726         if (context_struct_to_string(ncontext, &n, &nlen))
 727                 goto out;
 728         if (context_struct_to_string(tcontext, &t, &tlen))
 729                 goto out;
 730         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 731                   "op=security_validate_transition seresult=denied"
 732                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 733                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 734 out:
 735         kfree(o);
 736         kfree(n);
 737         kfree(t);
 738
 739         if (!selinux_enforcing)
 740                 return 0;
 741         return -EPERM;
 742 }
 743
 744 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 745                                  u16 orig_tclass)
 746 {
 747         struct context *ocontext;
 748         struct context *ncontext;
 749         struct context *tcontext;
 750         struct class_datum *tclass_datum;
 751         struct constraint_node *constraint;
 752         u16 tclass;
 753         int rc = 0;
 754
 755         if (!ss_initialized)
 756                 return 0;
 757
 758         read_lock(&policy_rwlock);
 759
 760         tclass = unmap_class(orig_tclass);
 761
 762         if (!tclass || tclass > policydb.p_classes.nprim) {
 763                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 764                         __func__, tclass);
 765                 rc = -EINVAL;
 766                 goto out;
 767         }
 768         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 769
 770         ocontext = sidtab_search(&sidtab, oldsid);
 771         if (!ocontext) {
 772                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 773                         __func__, oldsid);
 774                 rc = -EINVAL;
 775                 goto out;
 776         }
 777
 778         ncontext = sidtab_search(&sidtab, newsid);
 779         if (!ncontext) {
 780                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 781                         __func__, newsid);
 782                 rc = -EINVAL;
 783                 goto out;
 784         }
 785
 786         tcontext = sidtab_search(&sidtab, tasksid);
 787         if (!tcontext) {
 788                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 789                         __func__, tasksid);
 790                 rc = -EINVAL;
 791                 goto out;
 792         }
 793
 794         constraint = tclass_datum->validatetrans;
 795         while (constraint) {
 796                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 797                                           constraint->expr)) {
 798                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 799                                                              tcontext, tclass);
 800                         goto out;
 801                 }
 802                 constraint = constraint->next;
 803         }
 804
 805 out:
 806         read_unlock(&policy_rwlock);
 807         return rc;
 808 }
 809
 810 /*
 811  * security_bounded_transition - check whether the given
 812  * transition is directed to bounded, or not.
 813  * It returns 0, if @newsid is bounded by @oldsid.
 814  * Otherwise, it returns error code.
 815  *
 816  * @oldsid : current security identifier
 817  * @newsid : destinated security identifier
 818  */
 819 int security_bounded_transition(u32 old_sid, u32 new_sid)
 820 {
 821         struct context *old_context, *new_context;
 822         struct type_datum *type;
 823         int index;
 824         int rc;
 825
 826         read_lock(&policy_rwlock);
 827
 828         rc = -EINVAL;
 829         old_context = sidtab_search(&sidtab, old_sid);
 830         if (!old_context) {
 831                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 832                        __func__, old_sid);
 833                 goto out;
 834         }
 835
 836         rc = -EINVAL;
 837         new_context = sidtab_search(&sidtab, new_sid);
 838         if (!new_context) {
 839                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 840                        __func__, new_sid);
 841                 goto out;
 842         }
 843
 844         rc = 0;
 845         /* type/domain unchanged */
 846         if (old_context->type == new_context->type)
 847                 goto out;
 848
 849         index = new_context->type;
 850         while (true) {
 851                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 852                                           index - 1);
 853                 BUG_ON(!type);
 854
 855                 /* not bounded anymore */
 856                 rc = -EPERM;
 857                 if (!type->bounds)
 858                         break;
 859
 860                 /* @newsid is bounded by @oldsid */
 861                 rc = 0;
 862                 if (type->bounds == old_context->type)
 863                         break;
 864
 865                 index = type->bounds;
 866         }
 867
 868         if (rc) {
 869                 char *old_name = NULL;
 870                 char *new_name = NULL;
 871                 u32 length;
 872
 873                 if (!context_struct_to_string(old_context,
 874                                               &old_name, &length) &&
 875                     !context_struct_to_string(new_context,
 876                                               &new_name, &length)) {
 877                         audit_log(current->audit_context,
 878                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 879                                   "op=security_bounded_transition "
 880                                   "seresult=denied "
 881                                   "oldcontext=%s newcontext=%s",
 882                                   old_name, new_name);
 883                 }
 884                 kfree(new_name);
 885                 kfree(old_name);
 886         }
 887 out:
 888         read_unlock(&policy_rwlock);
 889
 890         return rc;
 891 }
 892
 893 static void avd_init(struct av_decision *avd)
 894 {
 895         avd->allowed = 0;
 896         avd->auditallow = 0;
 897         avd->auditdeny = 0xffffffff;
 898         avd->seqno = latest_granting;
 899         avd->flags = 0;
 900 }
 901
 902
 903 /**
 904  * security_compute_av - Compute access vector decisions.
 905  * @ssid: source security identifier
 906  * @tsid: target security identifier
 907  * @tclass: target security class
 908  * @avd: access vector decisions
 909  *
 910  * Compute a set of access vector decisions based on the
 911  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 912  */
 913 void security_compute_av(u32 ssid,
 914                          u32 tsid,
 915                          u16 orig_tclass,
 916                          struct av_decision *avd)
 917 {
 918         u16 tclass;
 919         struct context *scontext = NULL, *tcontext = NULL;
 920
 921         read_lock(&policy_rwlock);
 922         avd_init(avd);
 923         if (!ss_initialized)
 924                 goto allow;
 925
 926         scontext = sidtab_search(&sidtab, ssid);
 927         if (!scontext) {
 928                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 929                        __func__, ssid);
 930                 goto out;
 931         }
 932
 933         /* permissive domain? */
 934         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 935                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 936
 937         tcontext = sidtab_search(&sidtab, tsid);
 938         if (!tcontext) {
 939                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 940                        __func__, tsid);
 941                 goto out;
 942         }
 943
 944         tclass = unmap_class(orig_tclass);
 945         if (unlikely(orig_tclass && !tclass)) {
 946                 if (policydb.allow_unknown)
 947                         goto allow;
 948                 goto out;
 949         }
 950         context_struct_compute_av(scontext, tcontext, tclass, avd);
 951         map_decision(orig_tclass, avd, policydb.allow_unknown);
 952 out:
 953         read_unlock(&policy_rwlock);
 954         return;
 955 allow:
 956         avd->allowed = 0xffffffff;
 957         goto out;
 958 }
 959
 960 void security_compute_av_user(u32 ssid,
 961                               u32 tsid,
 962                               u16 tclass,
 963                               struct av_decision *avd)
 964 {
 965         struct context *scontext = NULL, *tcontext = NULL;
 966
 967         read_lock(&policy_rwlock);
 968         avd_init(avd);
 969         if (!ss_initialized)
 970                 goto allow;
 971
 972         scontext = sidtab_search(&sidtab, ssid);
 973         if (!scontext) {
 974                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 975                        __func__, ssid);
 976                 goto out;
 977         }
 978
 979         /* permissive domain? */
 980         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 981                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 982
 983         tcontext = sidtab_search(&sidtab, tsid);
 984         if (!tcontext) {
 985                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 986                        __func__, tsid);
 987                 goto out;
 988         }
 989
 990         if (unlikely(!tclass)) {
 991                 if (policydb.allow_unknown)
 992                         goto allow;
 993                 goto out;
 994         }
 995
 996         context_struct_compute_av(scontext, tcontext, tclass, avd);
 997  out:
 998         read_unlock(&policy_rwlock);
 999         return;
1000 allow:
1001         avd->allowed = 0xffffffff;
1002         goto out;
1003 }
1004
1005 /*
1006  * Write the security context string representation of
1007  * the context structure `context' into a dynamically
1008  * allocated string of the correct size.  Set `*scontext'
1009  * to point to this string and set `*scontext_len' to
1010  * the length of the string.
1011  */
1012 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1013 {
1014         char *scontextp;
1015
1016         if (scontext)
1017                 *scontext = NULL;
1018         *scontext_len = 0;
1019
1020         if (context->len) {
1021                 *scontext_len = context->len;
1022                 if (scontext) {
1023                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1024                         if (!(*scontext))
1025                                 return -ENOMEM;
1026                 }
1027                 return 0;
1028         }
1029
1030         /* Compute the size of the context. */
1031         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1032         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1033         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1034         *scontext_len += mls_compute_context_len(context);
1035
1036         if (!scontext)
1037                 return 0;
1038
1039         /* Allocate space for the context; caller must free this space. */
1040         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1041         if (!scontextp)
1042                 return -ENOMEM;
1043         *scontext = scontextp;
1044
1045         /*
1046          * Copy the user name, role name and type name into the context.
1047          */
1048         sprintf(scontextp, "%s:%s:%s",
1049                 sym_name(&policydb, SYM_USERS, context->user - 1),
1050                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1051                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1052         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1053                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1054                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1055
1056         mls_sid_to_context(context, &scontextp);
1057
1058         *scontextp = 0;
1059
1060         return 0;
1061 }
1062
1063 #include "initial_sid_to_string.h"
1064
1065 const char *security_get_initial_sid_context(u32 sid)
1066 {
1067         if (unlikely(sid > SECINITSID_NUM))
1068                 return NULL;
1069         return initial_sid_to_string[sid];
1070 }
1071
1072 static int security_sid_to_context_core(u32 sid, char **scontext,
1073                                         u32 *scontext_len, int force)
1074 {
1075         struct context *context;
1076         int rc = 0;
1077
1078         if (scontext)
1079                 *scontext = NULL;
1080         *scontext_len  = 0;
1081
1082         if (!ss_initialized) {
1083                 if (sid <= SECINITSID_NUM) {
1084                         char *scontextp;
1085
1086                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1087                         if (!scontext)
1088                                 goto out;
1089                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1090                         if (!scontextp) {
1091                                 rc = -ENOMEM;
1092                                 goto out;
1093                         }
1094                         strcpy(scontextp, initial_sid_to_string[sid]);
1095                         *scontext = scontextp;
1096                         goto out;
1097                 }
1098                 printk(KERN_ERR "SELinux: %s:  called before initial "
1099                        "load_policy on unknown SID %d\n", __func__, sid);
1100                 rc = -EINVAL;
1101                 goto out;
1102         }
1103         read_lock(&policy_rwlock);
1104         if (force)
1105                 context = sidtab_search_force(&sidtab, sid);
1106         else
1107                 context = sidtab_search(&sidtab, sid);
1108         if (!context) {
1109                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1110                         __func__, sid);
1111                 rc = -EINVAL;
1112                 goto out_unlock;
1113         }
1114         rc = context_struct_to_string(context, scontext, scontext_len);
1115 out_unlock:
1116         read_unlock(&policy_rwlock);
1117 out:
1118         return rc;
1119
1120 }
1121
1122 /**
1123  * security_sid_to_context - Obtain a context for a given SID.
1124  * @sid: security identifier, SID
1125  * @scontext: security context
1126  * @scontext_len: length in bytes
1127  *
1128  * Write the string representation of the context associated with @sid
1129  * into a dynamically allocated string of the correct size.  Set @scontext
1130  * to point to this string and set @scontext_len to the length of the string.
1131  */
1132 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1133 {
1134         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1135 }
1136
1137 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1138 {
1139         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1140 }
1141
1142 /*
1143  * Caveat:  Mutates scontext.
1144  */
1145 static int string_to_context_struct(struct policydb *pol,
1146                                     struct sidtab *sidtabp,
1147                                     char *scontext,
1148                                     u32 scontext_len,
1149                                     struct context *ctx,
1150                                     u32 def_sid)
1151 {
1152         struct role_datum *role;
1153         struct type_datum *typdatum;
1154         struct user_datum *usrdatum;
1155         char *scontextp, *p, oldc;
1156         int rc = 0;
1157
1158         context_init(ctx);
1159
1160         /* Parse the security context. */
1161
1162         rc = -EINVAL;
1163         scontextp = (char *) scontext;
1164
1165         /* Extract the user. */
1166         p = scontextp;
1167         while (*p && *p != ':')
1168                 p++;
1169
1170         if (*p == 0)
1171                 goto out;
1172
1173         *p++ = 0;
1174
1175         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1176         if (!usrdatum)
1177                 goto out;
1178
1179         ctx->user = usrdatum->value;
1180
1181         /* Extract role. */
1182         scontextp = p;
1183         while (*p && *p != ':')
1184                 p++;
1185
1186         if (*p == 0)
1187                 goto out;
1188
1189         *p++ = 0;
1190
1191         role = hashtab_search(pol->p_roles.table, scontextp);
1192         if (!role)
1193                 goto out;
1194         ctx->role = role->value;
1195
1196         /* Extract type. */
1197         scontextp = p;
1198         while (*p && *p != ':')
1199                 p++;
1200         oldc = *p;
1201         *p++ = 0;
1202
1203         typdatum = hashtab_search(pol->p_types.table, scontextp);
1204         if (!typdatum || typdatum->attribute)
1205                 goto out;
1206
1207         ctx->type = typdatum->value;
1208
1209         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1210         if (rc)
1211                 goto out;
1212
1213         rc = -EINVAL;
1214         if ((p - scontext) < scontext_len)
1215                 goto out;
1216
1217         /* Check the validity of the new context. */
1218         if (!policydb_context_isvalid(pol, ctx))
1219                 goto out;
1220         rc = 0;
1221 out:
1222         if (rc)
1223                 context_destroy(ctx);
1224         return rc;
1225 }
1226
1227 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1228                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1229                                         int force)
1230 {
1231         char *scontext2, *str = NULL;
1232         struct context context;
1233         int rc = 0;
1234
1235         /* An empty security context is never valid. */
1236         if (!scontext_len)
1237                 return -EINVAL;
1238
1239         if (!ss_initialized) {
1240                 int i;
1241
1242                 for (i = 1; i < SECINITSID_NUM; i++) {
1243                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1244                                 *sid = i;
1245                                 return 0;
1246                         }
1247                 }
1248                 *sid = SECINITSID_KERNEL;
1249                 return 0;
1250         }
1251         *sid = SECSID_NULL;
1252
1253         /* Copy the string so that we can modify the copy as we parse it. */
1254         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1255         if (!scontext2)
1256                 return -ENOMEM;
1257         memcpy(scontext2, scontext, scontext_len);
1258         scontext2[scontext_len] = 0;
1259
1260         if (force) {
1261                 /* Save another copy for storing in uninterpreted form */
1262                 rc = -ENOMEM;
1263                 str = kstrdup(scontext2, gfp_flags);
1264                 if (!str)
1265                         goto out;
1266         }
1267
1268         read_lock(&policy_rwlock);
1269         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1270                                       scontext_len, &context, def_sid);
1271         if (rc == -EINVAL && force) {
1272                 context.str = str;
1273                 context.len = scontext_len;
1274                 str = NULL;
1275         } else if (rc)
1276                 goto out_unlock;
1277         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1278         context_destroy(&context);
1279 out_unlock:
1280         read_unlock(&policy_rwlock);
1281 out:
1282         kfree(scontext2);
1283         kfree(str);
1284         return rc;
1285 }
1286
1287 /**
1288  * security_context_to_sid - Obtain a SID for a given security context.
1289  * @scontext: security context
1290  * @scontext_len: length in bytes
1291  * @sid: security identifier, SID
1292  * @gfp: context for the allocation
1293  *
1294  * Obtains a SID associated with the security context that
1295  * has the string representation specified by @scontext.
1296  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1297  * memory is available, or 0 on success.
1298  */
1299 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1300                             gfp_t gfp)
1301 {
1302         return security_context_to_sid_core(scontext, scontext_len,
1303                                             sid, SECSID_NULL, gfp, 0);
1304 }
1305
1306 /**
1307  * security_context_to_sid_default - Obtain a SID for a given security context,
1308  * falling back to specified default if needed.
1309  *
1310  * @scontext: security context
1311  * @scontext_len: length in bytes
1312  * @sid: security identifier, SID
1313  * @def_sid: default SID to assign on error
1314  *
1315  * Obtains a SID associated with the security context that
1316  * has the string representation specified by @scontext.
1317  * The default SID is passed to the MLS layer to be used to allow
1318  * kernel labeling of the MLS field if the MLS field is not present
1319  * (for upgrading to MLS without full relabel).
1320  * Implicitly forces adding of the context even if it cannot be mapped yet.
1321  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1322  * memory is available, or 0 on success.
1323  */
1324 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1325                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1326 {
1327         return security_context_to_sid_core(scontext, scontext_len,
1328                                             sid, def_sid, gfp_flags, 1);
1329 }
1330
1331 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1332                                   u32 *sid)
1333 {
1334         return security_context_to_sid_core(scontext, scontext_len,
1335                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1336 }
1337
1338 static int compute_sid_handle_invalid_context(
1339         struct context *scontext,
1340         struct context *tcontext,
1341         u16 tclass,
1342         struct context *newcontext)
1343 {
1344         char *s = NULL, *t = NULL, *n = NULL;
1345         u32 slen, tlen, nlen;
1346
1347         if (context_struct_to_string(scontext, &s, &slen))
1348                 goto out;
1349         if (context_struct_to_string(tcontext, &t, &tlen))
1350                 goto out;
1351         if (context_struct_to_string(newcontext, &n, &nlen))
1352                 goto out;
1353         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1354                   "op=security_compute_sid invalid_context=%s"
1355                   " scontext=%s"
1356                   " tcontext=%s"
1357                   " tclass=%s",
1358                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1359 out:
1360         kfree(s);
1361         kfree(t);
1362         kfree(n);
1363         if (!selinux_enforcing)
1364                 return 0;
1365         return -EACCES;
1366 }
1367
1368 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1369                                   u32 stype, u32 ttype, u16 tclass,
1370                                   const char *objname)
1371 {
1372         struct filename_trans ft;
1373         struct filename_trans_datum *otype;
1374
1375         /*
1376          * Most filename trans rules are going to live in specific directories
1377          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1378          * if the ttype does not contain any rules.
1379          */
1380         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1381                 return;
1382
1383         ft.stype = stype;
1384         ft.ttype = ttype;
1385         ft.tclass = tclass;
1386         ft.name = objname;
1387
1388         otype = hashtab_search(p->filename_trans, &ft);
1389         if (otype)
1390                 newcontext->type = otype->otype;
1391 }
1392
1393 static int security_compute_sid(u32 ssid,
1394                                 u32 tsid,
1395                                 u16 orig_tclass,
1396                                 u32 specified,
1397                                 const char *objname,
1398                                 u32 *out_sid,
1399                                 bool kern)
1400 {
1401         struct class_datum *cladatum = NULL;
1402         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1403         struct role_trans *roletr = NULL;
1404         struct avtab_key avkey;
1405         struct avtab_datum *avdatum;
1406         struct avtab_node *node;
1407         u16 tclass;
1408         int rc = 0;
1409         bool sock;
1410
1411         if (!ss_initialized) {
1412                 switch (orig_tclass) {
1413                 case SECCLASS_PROCESS: /* kernel value */
1414                         *out_sid = ssid;
1415                         break;
1416                 default:
1417                         *out_sid = tsid;
1418                         break;
1419                 }
1420                 goto out;
1421         }
1422
1423         context_init(&newcontext);
1424
1425         read_lock(&policy_rwlock);
1426
1427         if (kern) {
1428                 tclass = unmap_class(orig_tclass);
1429                 sock = security_is_socket_class(orig_tclass);
1430         } else {
1431                 tclass = orig_tclass;
1432                 sock = security_is_socket_class(map_class(tclass));
1433         }
1434
1435         scontext = sidtab_search(&sidtab, ssid);
1436         if (!scontext) {
1437                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1438                        __func__, ssid);
1439                 rc = -EINVAL;
1440                 goto out_unlock;
1441         }
1442         tcontext = sidtab_search(&sidtab, tsid);
1443         if (!tcontext) {
1444                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1445                        __func__, tsid);
1446                 rc = -EINVAL;
1447                 goto out_unlock;
1448         }
1449
1450         if (tclass && tclass <= policydb.p_classes.nprim)
1451                 cladatum = policydb.class_val_to_struct[tclass - 1];
1452
1453         /* Set the user identity. */
1454         switch (specified) {
1455         case AVTAB_TRANSITION:
1456         case AVTAB_CHANGE:
1457                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1458                         newcontext.user = tcontext->user;
1459                 } else {
1460                         /* notice this gets both DEFAULT_SOURCE and unset */
1461                         /* Use the process user identity. */
1462                         newcontext.user = scontext->user;
1463                 }
1464                 break;
1465         case AVTAB_MEMBER:
1466                 /* Use the related object owner. */
1467                 newcontext.user = tcontext->user;
1468                 break;
1469         }
1470
1471         /* Set the role to default values. */
1472         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1473                 newcontext.role = scontext->role;
1474         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1475                 newcontext.role = tcontext->role;
1476         } else {
1477                 if ((tclass == policydb.process_class) || (sock == true))
1478                         newcontext.role = scontext->role;
1479                 else
1480                         newcontext.role = OBJECT_R_VAL;
1481         }
1482
1483         /* Set the type to default values. */
1484         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1485                 newcontext.type = scontext->type;
1486         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1487                 newcontext.type = tcontext->type;
1488         } else {
1489                 if ((tclass == policydb.process_class) || (sock == true)) {
1490                         /* Use the type of process. */
1491                         newcontext.type = scontext->type;
1492                 } else {
1493                         /* Use the type of the related object. */
1494                         newcontext.type = tcontext->type;
1495                 }
1496         }
1497
1498         /* Look for a type transition/member/change rule. */
1499         avkey.source_type = scontext->type;
1500         avkey.target_type = tcontext->type;
1501         avkey.target_class = tclass;
1502         avkey.specified = specified;
1503         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1504
1505         /* If no permanent rule, also check for enabled conditional rules */
1506         if (!avdatum) {
1507                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1508                 for (; node; node = avtab_search_node_next(node, specified)) {
1509                         if (node->key.specified & AVTAB_ENABLED) {
1510                                 avdatum = &node->datum;
1511                                 break;
1512                         }
1513                 }
1514         }
1515
1516         if (avdatum) {
1517                 /* Use the type from the type transition/member/change rule. */
1518                 newcontext.type = avdatum->data;
1519         }
1520
1521         /* if we have a objname this is a file trans check so check those rules */
1522         if (objname)
1523                 filename_compute_type(&policydb, &newcontext, scontext->type,
1524                                       tcontext->type, tclass, objname);
1525
1526         /* Check for class-specific changes. */
1527         if (specified & AVTAB_TRANSITION) {
1528                 /* Look for a role transition rule. */
1529                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1530                         if ((roletr->role == scontext->role) &&
1531                             (roletr->type == tcontext->type) &&
1532                             (roletr->tclass == tclass)) {
1533                                 /* Use the role transition rule. */
1534                                 newcontext.role = roletr->new_role;
1535                                 break;
1536                         }
1537                 }
1538         }
1539
1540         /* Set the MLS attributes.
1541            This is done last because it may allocate memory. */
1542         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1543                              &newcontext, sock);
1544         if (rc)
1545                 goto out_unlock;
1546
1547         /* Check the validity of the context. */
1548         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1549                 rc = compute_sid_handle_invalid_context(scontext,
1550                                                         tcontext,
1551                                                         tclass,
1552                                                         &newcontext);
1553                 if (rc)
1554                         goto out_unlock;
1555         }
1556         /* Obtain the sid for the context. */
1557         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1558 out_unlock:
1559         read_unlock(&policy_rwlock);
1560         context_destroy(&newcontext);
1561 out:
1562         return rc;
1563 }
1564
1565 /**
1566  * security_transition_sid - Compute the SID for a new subject/object.
1567  * @ssid: source security identifier
1568  * @tsid: target security identifier
1569  * @tclass: target security class
1570  * @out_sid: security identifier for new subject/object
1571  *
1572  * Compute a SID to use for labeling a new subject or object in the
1573  * class @tclass based on a SID pair (@ssid, @tsid).
1574  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1575  * if insufficient memory is available, or %0 if the new SID was
1576  * computed successfully.
1577  */
1578 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1579                             const struct qstr *qstr, u32 *out_sid)
1580 {
1581         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1582                                     qstr ? qstr->name : NULL, out_sid, true);
1583 }
1584
1585 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1586                                  const char *objname, u32 *out_sid)
1587 {
1588         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1589                                     objname, out_sid, false);
1590 }
1591
1592 /**
1593  * security_member_sid - Compute the SID for member selection.
1594  * @ssid: source security identifier
1595  * @tsid: target security identifier
1596  * @tclass: target security class
1597  * @out_sid: security identifier for selected member
1598  *
1599  * Compute a SID to use when selecting a member of a polyinstantiated
1600  * object of class @tclass based on a SID pair (@ssid, @tsid).
1601  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1602  * if insufficient memory is available, or %0 if the SID was
1603  * computed successfully.
1604  */
1605 int security_member_sid(u32 ssid,
1606                         u32 tsid,
1607                         u16 tclass,
1608                         u32 *out_sid)
1609 {
1610         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1611                                     out_sid, false);
1612 }
1613
1614 /**
1615  * security_change_sid - Compute the SID for object relabeling.
1616  * @ssid: source security identifier
1617  * @tsid: target security identifier
1618  * @tclass: target security class
1619  * @out_sid: security identifier for selected member
1620  *
1621  * Compute a SID to use for relabeling an object of class @tclass
1622  * based on a SID pair (@ssid, @tsid).
1623  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1624  * if insufficient memory is available, or %0 if the SID was
1625  * computed successfully.
1626  */
1627 int security_change_sid(u32 ssid,
1628                         u32 tsid,
1629                         u16 tclass,
1630                         u32 *out_sid)
1631 {
1632         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1633                                     out_sid, false);
1634 }
1635
1636 /* Clone the SID into the new SID table. */
1637 static int clone_sid(u32 sid,
1638                      struct context *context,
1639                      void *arg)
1640 {
1641         struct sidtab *s = arg;
1642
1643         if (sid > SECINITSID_NUM)
1644                 return sidtab_insert(s, sid, context);
1645         else
1646                 return 0;
1647 }
1648
1649 static inline int convert_context_handle_invalid_context(struct context *context)
1650 {
1651         char *s;
1652         u32 len;
1653
1654         if (selinux_enforcing)
1655                 return -EINVAL;
1656
1657         if (!context_struct_to_string(context, &s, &len)) {
1658                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1659                 kfree(s);
1660         }
1661         return 0;
1662 }
1663
1664 struct convert_context_args {
1665         struct policydb *oldp;
1666         struct policydb *newp;
1667 };
1668
1669 /*
1670  * Convert the values in the security context
1671  * structure `c' from the values specified
1672  * in the policy `p->oldp' to the values specified
1673  * in the policy `p->newp'.  Verify that the
1674  * context is valid under the new policy.
1675  */
1676 static int convert_context(u32 key,
1677                            struct context *c,
1678                            void *p)
1679 {
1680         struct convert_context_args *args;
1681         struct context oldc;
1682         struct ocontext *oc;
1683         struct mls_range *range;
1684         struct role_datum *role;
1685         struct type_datum *typdatum;
1686         struct user_datum *usrdatum;
1687         char *s;
1688         u32 len;
1689         int rc = 0;
1690
1691         if (key <= SECINITSID_NUM)
1692                 goto out;
1693
1694         args = p;
1695
1696         if (c->str) {
1697                 struct context ctx;
1698
1699                 rc = -ENOMEM;
1700                 s = kstrdup(c->str, GFP_KERNEL);
1701                 if (!s)
1702                         goto out;
1703
1704                 rc = string_to_context_struct(args->newp, NULL, s,
1705                                               c->len, &ctx, SECSID_NULL);
1706                 kfree(s);
1707                 if (!rc) {
1708                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1709                                c->str);
1710                         /* Replace string with mapped representation. */
1711                         kfree(c->str);
1712                         memcpy(c, &ctx, sizeof(*c));
1713                         goto out;
1714                 } else if (rc == -EINVAL) {
1715                         /* Retain string representation for later mapping. */
1716                         rc = 0;
1717                         goto out;
1718                 } else {
1719                         /* Other error condition, e.g. ENOMEM. */
1720                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1721                                c->str, -rc);
1722                         goto out;
1723                 }
1724         }
1725
1726         rc = context_cpy(&oldc, c);
1727         if (rc)
1728                 goto out;
1729
1730         /* Convert the user. */
1731         rc = -EINVAL;
1732         usrdatum = hashtab_search(args->newp->p_users.table,
1733                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1734         if (!usrdatum)
1735                 goto bad;
1736         c->user = usrdatum->value;
1737
1738         /* Convert the role. */
1739         rc = -EINVAL;
1740         role = hashtab_search(args->newp->p_roles.table,
1741                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1742         if (!role)
1743                 goto bad;
1744         c->role = role->value;
1745
1746         /* Convert the type. */
1747         rc = -EINVAL;
1748         typdatum = hashtab_search(args->newp->p_types.table,
1749                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1750         if (!typdatum)
1751                 goto bad;
1752         c->type = typdatum->value;
1753
1754         /* Convert the MLS fields if dealing with MLS policies */
1755         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1756                 rc = mls_convert_context(args->oldp, args->newp, c);
1757                 if (rc)
1758                         goto bad;
1759         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1760                 /*
1761                  * Switching between MLS and non-MLS policy:
1762                  * free any storage used by the MLS fields in the
1763                  * context for all existing entries in the sidtab.
1764                  */
1765                 mls_context_destroy(c);
1766         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1767                 /*
1768                  * Switching between non-MLS and MLS policy:
1769                  * ensure that the MLS fields of the context for all
1770                  * existing entries in the sidtab are filled in with a
1771                  * suitable default value, likely taken from one of the
1772                  * initial SIDs.
1773                  */
1774                 oc = args->newp->ocontexts[OCON_ISID];
1775                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1776                         oc = oc->next;
1777                 rc = -EINVAL;
1778                 if (!oc) {
1779                         printk(KERN_ERR "SELinux:  unable to look up"
1780                                 " the initial SIDs list\n");
1781                         goto bad;
1782                 }
1783                 range = &oc->context[0].range;
1784                 rc = mls_range_set(c, range);
1785                 if (rc)
1786                         goto bad;
1787         }
1788
1789         /* Check the validity of the new context. */
1790         if (!policydb_context_isvalid(args->newp, c)) {
1791                 rc = convert_context_handle_invalid_context(&oldc);
1792                 if (rc)
1793                         goto bad;
1794         }
1795
1796         context_destroy(&oldc);
1797
1798         rc = 0;
1799 out:
1800         return rc;
1801 bad:
1802         /* Map old representation to string and save it. */
1803         rc = context_struct_to_string(&oldc, &s, &len);
1804         if (rc)
1805                 return rc;
1806         context_destroy(&oldc);
1807         context_destroy(c);
1808         c->str = s;
1809         c->len = len;
1810         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1811                c->str);
1812         rc = 0;
1813         goto out;
1814 }
1815
1816 static void security_load_policycaps(void)
1817 {
1818         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1819                                                   POLICYDB_CAPABILITY_NETPEER);
1820         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1821                                                   POLICYDB_CAPABILITY_OPENPERM);
1822         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1823                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1824 }
1825
1826 static int security_preserve_bools(struct policydb *p);
1827
1828 /**
1829  * security_load_policy - Load a security policy configuration.
1830  * @data: binary policy data
1831  * @len: length of data in bytes
1832  *
1833  * Load a new set of security policy configuration data,
1834  * validate it and convert the SID table as necessary.
1835  * This function will flush the access vector cache after
1836  * loading the new policy.
1837  */
1838 int security_load_policy(void *data, size_t len)
1839 {
1840         struct policydb *oldpolicydb, *newpolicydb;
1841         struct sidtab oldsidtab, newsidtab;
1842         struct selinux_mapping *oldmap, *map = NULL;
1843         struct convert_context_args args;
1844         u32 seqno;
1845         u16 map_size;
1846         int rc = 0;
1847         struct policy_file file = { data, len }, *fp = &file;
1848
1849         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
1850         if (!oldpolicydb) {
1851                 rc = -ENOMEM;
1852                 goto out;
1853         }
1854         newpolicydb = oldpolicydb + 1;
1855
1856         if (!ss_initialized) {
1857                 avtab_cache_init();
1858                 rc = policydb_read(&policydb, fp);
1859                 if (rc) {
1860                         avtab_cache_destroy();
1861                         goto out;
1862                 }
1863
1864                 policydb.len = len;
1865                 rc = selinux_set_mapping(&policydb, secclass_map,
1866                                          &current_mapping,
1867                                          &current_mapping_size);
1868                 if (rc) {
1869                         policydb_destroy(&policydb);
1870                         avtab_cache_destroy();
1871                         goto out;
1872                 }
1873
1874                 rc = policydb_load_isids(&policydb, &sidtab);
1875                 if (rc) {
1876                         policydb_destroy(&policydb);
1877                         avtab_cache_destroy();
1878                         goto out;
1879                 }
1880
1881                 security_load_policycaps();
1882                 ss_initialized = 1;
1883                 seqno = ++latest_granting;
1884                 selinux_complete_init();
1885                 avc_ss_reset(seqno);
1886                 selnl_notify_policyload(seqno);
1887                 selinux_status_update_policyload(seqno);
1888                 selinux_netlbl_cache_invalidate();
1889                 selinux_xfrm_notify_policyload();
1890                 goto out;
1891         }
1892
1893 #if 0
1894         sidtab_hash_eval(&sidtab, "sids");
1895 #endif
1896
1897         rc = policydb_read(newpolicydb, fp);
1898         if (rc)
1899                 goto out;
1900
1901         newpolicydb->len = len;
1902         /* If switching between different policy types, log MLS status */
1903         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
1904                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1905         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
1906                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1907
1908         rc = policydb_load_isids(newpolicydb, &newsidtab);
1909         if (rc) {
1910                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1911                 policydb_destroy(newpolicydb);
1912                 goto out;
1913         }
1914
1915         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
1916         if (rc)
1917                 goto err;
1918
1919         rc = security_preserve_bools(newpolicydb);
1920         if (rc) {
1921                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1922                 goto err;
1923         }
1924
1925         /* Clone the SID table. */
1926         sidtab_shutdown(&sidtab);
1927
1928         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1929         if (rc)
1930                 goto err;
1931
1932         /*
1933          * Convert the internal representations of contexts
1934          * in the new SID table.
1935          */
1936         args.oldp = &policydb;
1937         args.newp = newpolicydb;
1938         rc = sidtab_map(&newsidtab, convert_context, &args);
1939         if (rc) {
1940                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1941                         " representation of contexts in the new SID"
1942                         " table\n");
1943                 goto err;
1944         }
1945
1946         /* Save the old policydb and SID table to free later. */
1947         memcpy(oldpolicydb, &policydb, sizeof(policydb));
1948         sidtab_set(&oldsidtab, &sidtab);
1949
1950         /* Install the new policydb and SID table. */
1951         write_lock_irq(&policy_rwlock);
1952         memcpy(&policydb, newpolicydb, sizeof(policydb));
1953         sidtab_set(&sidtab, &newsidtab);
1954         security_load_policycaps();
1955         oldmap = current_mapping;
1956         current_mapping = map;
1957         current_mapping_size = map_size;
1958         seqno = ++latest_granting;
1959         write_unlock_irq(&policy_rwlock);
1960
1961         /* Free the old policydb and SID table. */
1962         policydb_destroy(oldpolicydb);
1963         sidtab_destroy(&oldsidtab);
1964         kfree(oldmap);
1965
1966         avc_ss_reset(seqno);
1967         selnl_notify_policyload(seqno);
1968         selinux_status_update_policyload(seqno);
1969         selinux_netlbl_cache_invalidate();
1970         selinux_xfrm_notify_policyload();
1971
1972         rc = 0;
1973         goto out;
1974
1975 err:
1976         kfree(map);
1977         sidtab_destroy(&newsidtab);
1978         policydb_destroy(newpolicydb);
1979
1980 out:
1981         kfree(oldpolicydb);
1982         return rc;
1983 }
1984
1985 size_t security_policydb_len(void)
1986 {
1987         size_t len;
1988
1989         read_lock(&policy_rwlock);
1990         len = policydb.len;
1991         read_unlock(&policy_rwlock);
1992
1993         return len;
1994 }
1995
1996 /**
1997  * security_port_sid - Obtain the SID for a port.
1998  * @protocol: protocol number
1999  * @port: port number
2000  * @out_sid: security identifier
2001  */
2002 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2003 {
2004         struct ocontext *c;
2005         int rc = 0;
2006
2007         read_lock(&policy_rwlock);
2008
2009         c = policydb.ocontexts[OCON_PORT];
2010         while (c) {
2011                 if (c->u.port.protocol == protocol &&
2012                     c->u.port.low_port <= port &&
2013                     c->u.port.high_port >= port)
2014                         break;
2015                 c = c->next;
2016         }
2017
2018         if (c) {
2019                 if (!c->sid[0]) {
2020                         rc = sidtab_context_to_sid(&sidtab,
2021                                                    &c->context[0],
2022                                                    &c->sid[0]);
2023                         if (rc)
2024                                 goto out;
2025                 }
2026                 *out_sid = c->sid[0];
2027         } else {
2028                 *out_sid = SECINITSID_PORT;
2029         }
2030
2031 out:
2032         read_unlock(&policy_rwlock);
2033         return rc;
2034 }
2035
2036 /**
2037  * security_netif_sid - Obtain the SID for a network interface.
2038  * @name: interface name
2039  * @if_sid: interface SID
2040  */
2041 int security_netif_sid(char *name, u32 *if_sid)
2042 {
2043         int rc = 0;
2044         struct ocontext *c;
2045
2046         read_lock(&policy_rwlock);
2047
2048         c = policydb.ocontexts[OCON_NETIF];
2049         while (c) {
2050                 if (strcmp(name, c->u.name) == 0)
2051                         break;
2052                 c = c->next;
2053         }
2054
2055         if (c) {
2056                 if (!c->sid[0] || !c->sid[1]) {
2057                         rc = sidtab_context_to_sid(&sidtab,
2058                                                   &c->context[0],
2059                                                   &c->sid[0]);
2060                         if (rc)
2061                                 goto out;
2062                         rc = sidtab_context_to_sid(&sidtab,
2063                                                    &c->context[1],
2064                                                    &c->sid[1]);
2065                         if (rc)
2066                                 goto out;
2067                 }
2068                 *if_sid = c->sid[0];
2069         } else
2070                 *if_sid = SECINITSID_NETIF;
2071
2072 out:
2073         read_unlock(&policy_rwlock);
2074         return rc;
2075 }
2076
2077 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2078 {
2079         int i, fail = 0;
2080
2081         for (i = 0; i < 4; i++)
2082                 if (addr[i] != (input[i] & mask[i])) {
2083                         fail = 1;
2084                         break;
2085                 }
2086
2087         return !fail;
2088 }
2089
2090 /**
2091  * security_node_sid - Obtain the SID for a node (host).
2092  * @domain: communication domain aka address family
2093  * @addrp: address
2094  * @addrlen: address length in bytes
2095  * @out_sid: security identifier
2096  */
2097 int security_node_sid(u16 domain,
2098                       void *addrp,
2099                       u32 addrlen,
2100                       u32 *out_sid)
2101 {
2102         int rc;
2103         struct ocontext *c;
2104
2105         read_lock(&policy_rwlock);
2106
2107         switch (domain) {
2108         case AF_INET: {
2109                 u32 addr;
2110
2111                 rc = -EINVAL;
2112                 if (addrlen != sizeof(u32))
2113                         goto out;
2114
2115                 addr = *((u32 *)addrp);
2116
2117                 c = policydb.ocontexts[OCON_NODE];
2118                 while (c) {
2119                         if (c->u.node.addr == (addr & c->u.node.mask))
2120                                 break;
2121                         c = c->next;
2122                 }
2123                 break;
2124         }
2125
2126         case AF_INET6:
2127                 rc = -EINVAL;
2128                 if (addrlen != sizeof(u64) * 2)
2129                         goto out;
2130                 c = policydb.ocontexts[OCON_NODE6];
2131                 while (c) {
2132                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2133                                                 c->u.node6.mask))
2134                                 break;
2135                         c = c->next;
2136                 }
2137                 break;
2138
2139         default:
2140                 rc = 0;
2141                 *out_sid = SECINITSID_NODE;
2142                 goto out;
2143         }
2144
2145         if (c) {
2146                 if (!c->sid[0]) {
2147                         rc = sidtab_context_to_sid(&sidtab,
2148                                                    &c->context[0],
2149                                                    &c->sid[0]);
2150                         if (rc)
2151                                 goto out;
2152                 }
2153                 *out_sid = c->sid[0];
2154         } else {
2155                 *out_sid = SECINITSID_NODE;
2156         }
2157
2158         rc = 0;
2159 out:
2160         read_unlock(&policy_rwlock);
2161         return rc;
2162 }
2163
2164 #define SIDS_NEL 25
2165
2166 /**
2167  * security_get_user_sids - Obtain reachable SIDs for a user.
2168  * @fromsid: starting SID
2169  * @username: username
2170  * @sids: array of reachable SIDs for user
2171  * @nel: number of elements in @sids
2172  *
2173  * Generate the set of SIDs for legal security contexts
2174  * for a given user that can be reached by @fromsid.
2175  * Set *@sids to point to a dynamically allocated
2176  * array containing the set of SIDs.  Set *@nel to the
2177  * number of elements in the array.
2178  */
2179
2180 int security_get_user_sids(u32 fromsid,
2181                            char *username,
2182                            u32 **sids,
2183                            u32 *nel)
2184 {
2185         struct context *fromcon, usercon;
2186         u32 *mysids = NULL, *mysids2, sid;
2187         u32 mynel = 0, maxnel = SIDS_NEL;
2188         struct user_datum *user;
2189         struct role_datum *role;
2190         struct ebitmap_node *rnode, *tnode;
2191         int rc = 0, i, j;
2192
2193         *sids = NULL;
2194         *nel = 0;
2195
2196         if (!ss_initialized)
2197                 goto out;
2198
2199         read_lock(&policy_rwlock);
2200
2201         context_init(&usercon);
2202
2203         rc = -EINVAL;
2204         fromcon = sidtab_search(&sidtab, fromsid);
2205         if (!fromcon)
2206                 goto out_unlock;
2207
2208         rc = -EINVAL;
2209         user = hashtab_search(policydb.p_users.table, username);
2210         if (!user)
2211                 goto out_unlock;
2212
2213         usercon.user = user->value;
2214
2215         rc = -ENOMEM;
2216         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2217         if (!mysids)
2218                 goto out_unlock;
2219
2220         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2221                 role = policydb.role_val_to_struct[i];
2222                 usercon.role = i + 1;
2223                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2224                         usercon.type = j + 1;
2225
2226                         if (mls_setup_user_range(fromcon, user, &usercon))
2227                                 continue;
2228
2229                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2230                         if (rc)
2231                                 goto out_unlock;
2232                         if (mynel < maxnel) {
2233                                 mysids[mynel++] = sid;
2234                         } else {
2235                                 rc = -ENOMEM;
2236                                 maxnel += SIDS_NEL;
2237                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2238                                 if (!mysids2)
2239                                         goto out_unlock;
2240                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2241                                 kfree(mysids);
2242                                 mysids = mysids2;
2243                                 mysids[mynel++] = sid;
2244                         }
2245                 }
2246         }
2247         rc = 0;
2248 out_unlock:
2249         read_unlock(&policy_rwlock);
2250         if (rc || !mynel) {
2251                 kfree(mysids);
2252                 goto out;
2253         }
2254
2255         rc = -ENOMEM;
2256         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2257         if (!mysids2) {
2258                 kfree(mysids);
2259                 goto out;
2260         }
2261         for (i = 0, j = 0; i < mynel; i++) {
2262                 struct av_decision dummy_avd;
2263                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2264                                           SECCLASS_PROCESS, /* kernel value */
2265                                           PROCESS__TRANSITION, AVC_STRICT,
2266                                           &dummy_avd);
2267                 if (!rc)
2268                         mysids2[j++] = mysids[i];
2269                 cond_resched();
2270         }
2271         rc = 0;
2272         kfree(mysids);
2273         *sids = mysids2;
2274         *nel = j;
2275 out:
2276         return rc;
2277 }
2278
2279 /**
2280  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2281  * @fstype: filesystem type
2282  * @path: path from root of mount
2283  * @sclass: file security class
2284  * @sid: SID for path
2285  *
2286  * Obtain a SID to use for a file in a filesystem that
2287  * cannot support xattr or use a fixed labeling behavior like
2288  * transition SIDs or task SIDs.
2289  *
2290  * The caller must acquire the policy_rwlock before calling this function.
2291  */
2292 static inline int __security_genfs_sid(const char *fstype,
2293                                        char *path,
2294                                        u16 orig_sclass,
2295                                        u32 *sid)
2296 {
2297         int len;
2298         u16 sclass;
2299         struct genfs *genfs;
2300         struct ocontext *c;
2301         int rc, cmp = 0;
2302
2303         while (path[0] == '/' && path[1] == '/')
2304                 path++;
2305
2306         sclass = unmap_class(orig_sclass);
2307         *sid = SECINITSID_UNLABELED;
2308
2309         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2310                 cmp = strcmp(fstype, genfs->fstype);
2311                 if (cmp <= 0)
2312                         break;
2313         }
2314
2315         rc = -ENOENT;
2316         if (!genfs || cmp)
2317                 goto out;
2318
2319         for (c = genfs->head; c; c = c->next) {
2320                 len = strlen(c->u.name);
2321                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2322                     (strncmp(c->u.name, path, len) == 0))
2323                         break;
2324         }
2325
2326         rc = -ENOENT;
2327         if (!c)
2328                 goto out;
2329
2330         if (!c->sid[0]) {
2331                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2332                 if (rc)
2333                         goto out;
2334         }
2335
2336         *sid = c->sid[0];
2337         rc = 0;
2338 out:
2339         return rc;
2340 }
2341
2342 /**
2343  * security_genfs_sid - Obtain a SID for a file in a filesystem
2344  * @fstype: filesystem type
2345  * @path: path from root of mount
2346  * @sclass: file security class
2347  * @sid: SID for path
2348  *
2349  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2350  * it afterward.
2351  */
2352 int security_genfs_sid(const char *fstype,
2353                        char *path,
2354                        u16 orig_sclass,
2355                        u32 *sid)
2356 {
2357         int retval;
2358
2359         read_lock(&policy_rwlock);
2360         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2361         read_unlock(&policy_rwlock);
2362         return retval;
2363 }
2364
2365 /**
2366  * security_fs_use - Determine how to handle labeling for a filesystem.
2367  * @sb: superblock in question
2368  */
2369 int security_fs_use(struct super_block *sb)
2370 {
2371         int rc = 0;
2372         struct ocontext *c;
2373         struct superblock_security_struct *sbsec = sb->s_security;
2374         const char *fstype = sb->s_type->name;
2375
2376         read_lock(&policy_rwlock);
2377
2378         c = policydb.ocontexts[OCON_FSUSE];
2379         while (c) {
2380                 if (strcmp(fstype, c->u.name) == 0)
2381                         break;
2382                 c = c->next;
2383         }
2384
2385         if (c) {
2386                 sbsec->behavior = c->v.behavior;
2387                 if (!c->sid[0]) {
2388                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2389                                                    &c->sid[0]);
2390                         if (rc)
2391                                 goto out;
2392                 }
2393                 sbsec->sid = c->sid[0];
2394         } else {
2395                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2396                                           &sbsec->sid);
2397                 if (rc) {
2398                         sbsec->behavior = SECURITY_FS_USE_NONE;
2399                         rc = 0;
2400                 } else {
2401                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2402                 }
2403         }
2404
2405 out:
2406         read_unlock(&policy_rwlock);
2407         return rc;
2408 }
2409
2410 int security_get_bools(int *len, char ***names, int **values)
2411 {
2412         int i, rc;
2413
2414         read_lock(&policy_rwlock);
2415         *names = NULL;
2416         *values = NULL;
2417
2418         rc = 0;
2419         *len = policydb.p_bools.nprim;
2420         if (!*len)
2421                 goto out;
2422
2423         rc = -ENOMEM;
2424         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2425         if (!*names)
2426                 goto err;
2427
2428         rc = -ENOMEM;
2429         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2430         if (!*values)
2431                 goto err;
2432
2433         for (i = 0; i < *len; i++) {
2434                 size_t name_len;
2435
2436                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2437                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2438
2439                 rc = -ENOMEM;
2440                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2441                 if (!(*names)[i])
2442                         goto err;
2443
2444                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2445                 (*names)[i][name_len - 1] = 0;
2446         }
2447         rc = 0;
2448 out:
2449         read_unlock(&policy_rwlock);
2450         return rc;
2451 err:
2452         if (*names) {
2453                 for (i = 0; i < *len; i++)
2454                         kfree((*names)[i]);
2455         }
2456         kfree(*values);
2457         goto out;
2458 }
2459
2460
2461 int security_set_bools(int len, int *values)
2462 {
2463         int i, rc;
2464         int lenp, seqno = 0;
2465         struct cond_node *cur;
2466
2467         write_lock_irq(&policy_rwlock);
2468
2469         rc = -EFAULT;
2470         lenp = policydb.p_bools.nprim;
2471         if (len != lenp)
2472                 goto out;
2473
2474         for (i = 0; i < len; i++) {
2475                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2476                         audit_log(current->audit_context, GFP_ATOMIC,
2477                                 AUDIT_MAC_CONFIG_CHANGE,
2478                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2479                                 sym_name(&policydb, SYM_BOOLS, i),
2480                                 !!values[i],
2481                                 policydb.bool_val_to_struct[i]->state,
2482                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2483                                 audit_get_sessionid(current));
2484                 }
2485                 if (values[i])
2486                         policydb.bool_val_to_struct[i]->state = 1;
2487                 else
2488                         policydb.bool_val_to_struct[i]->state = 0;
2489         }
2490
2491         for (cur = policydb.cond_list; cur; cur = cur->next) {
2492                 rc = evaluate_cond_node(&policydb, cur);
2493                 if (rc)
2494                         goto out;
2495         }
2496
2497         seqno = ++latest_granting;
2498         rc = 0;
2499 out:
2500         write_unlock_irq(&policy_rwlock);
2501         if (!rc) {
2502                 avc_ss_reset(seqno);
2503                 selnl_notify_policyload(seqno);
2504                 selinux_status_update_policyload(seqno);
2505                 selinux_xfrm_notify_policyload();
2506         }
2507         return rc;
2508 }
2509
2510 int security_get_bool_value(int bool)
2511 {
2512         int rc;
2513         int len;
2514
2515         read_lock(&policy_rwlock);
2516
2517         rc = -EFAULT;
2518         len = policydb.p_bools.nprim;
2519         if (bool >= len)
2520                 goto out;
2521
2522         rc = policydb.bool_val_to_struct[bool]->state;
2523 out:
2524         read_unlock(&policy_rwlock);
2525         return rc;
2526 }
2527
2528 static int security_preserve_bools(struct policydb *p)
2529 {
2530         int rc, nbools = 0, *bvalues = NULL, i;
2531         char **bnames = NULL;
2532         struct cond_bool_datum *booldatum;
2533         struct cond_node *cur;
2534
2535         rc = security_get_bools(&nbools, &bnames, &bvalues);
2536         if (rc)
2537                 goto out;
2538         for (i = 0; i < nbools; i++) {
2539                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2540                 if (booldatum)
2541                         booldatum->state = bvalues[i];
2542         }
2543         for (cur = p->cond_list; cur; cur = cur->next) {
2544                 rc = evaluate_cond_node(p, cur);
2545                 if (rc)
2546                         goto out;
2547         }
2548
2549 out:
2550         if (bnames) {
2551                 for (i = 0; i < nbools; i++)
2552                         kfree(bnames[i]);
2553         }
2554         kfree(bnames);
2555         kfree(bvalues);
2556         return rc;
2557 }
2558
2559 /*
2560  * security_sid_mls_copy() - computes a new sid based on the given
2561  * sid and the mls portion of mls_sid.
2562  */
2563 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2564 {
2565         struct context *context1;
2566         struct context *context2;
2567         struct context newcon;
2568         char *s;
2569         u32 len;
2570         int rc;
2571
2572         rc = 0;
2573         if (!ss_initialized || !policydb.mls_enabled) {
2574                 *new_sid = sid;
2575                 goto out;
2576         }
2577
2578         context_init(&newcon);
2579
2580         read_lock(&policy_rwlock);
2581
2582         rc = -EINVAL;
2583         context1 = sidtab_search(&sidtab, sid);
2584         if (!context1) {
2585                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2586                         __func__, sid);
2587                 goto out_unlock;
2588         }
2589
2590         rc = -EINVAL;
2591         context2 = sidtab_search(&sidtab, mls_sid);
2592         if (!context2) {
2593                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2594                         __func__, mls_sid);
2595                 goto out_unlock;
2596         }
2597
2598         newcon.user = context1->user;
2599         newcon.role = context1->role;
2600         newcon.type = context1->type;
2601         rc = mls_context_cpy(&newcon, context2);
2602         if (rc)
2603                 goto out_unlock;
2604
2605         /* Check the validity of the new context. */
2606         if (!policydb_context_isvalid(&policydb, &newcon)) {
2607                 rc = convert_context_handle_invalid_context(&newcon);
2608                 if (rc) {
2609                         if (!context_struct_to_string(&newcon, &s, &len)) {
2610                                 audit_log(current->audit_context,
2611                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2612                                           "op=security_sid_mls_copy "
2613                                           "invalid_context=%s", s);
2614                                 kfree(s);
2615                         }
2616                         goto out_unlock;
2617                 }
2618         }
2619
2620         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2621 out_unlock:
2622         read_unlock(&policy_rwlock);
2623         context_destroy(&newcon);
2624 out:
2625         return rc;
2626 }
2627
2628 /**
2629  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2630  * @nlbl_sid: NetLabel SID
2631  * @nlbl_type: NetLabel labeling protocol type
2632  * @xfrm_sid: XFRM SID
2633  *
2634  * Description:
2635  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2636  * resolved into a single SID it is returned via @peer_sid and the function
2637  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2638  * returns a negative value.  A table summarizing the behavior is below:
2639  *
2640  *                                 | function return |      @sid
2641  *   ------------------------------+-----------------+-----------------
2642  *   no peer labels                |        0        |    SECSID_NULL
2643  *   single peer label             |        0        |    <peer_label>
2644  *   multiple, consistent labels   |        0        |    <peer_label>
2645  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2646  *
2647  */
2648 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2649                                  u32 xfrm_sid,
2650                                  u32 *peer_sid)
2651 {
2652         int rc;
2653         struct context *nlbl_ctx;
2654         struct context *xfrm_ctx;
2655
2656         *peer_sid = SECSID_NULL;
2657
2658         /* handle the common (which also happens to be the set of easy) cases
2659          * right away, these two if statements catch everything involving a
2660          * single or absent peer SID/label */
2661         if (xfrm_sid == SECSID_NULL) {
2662                 *peer_sid = nlbl_sid;
2663                 return 0;
2664         }
2665         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2666          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2667          * is present */
2668         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2669                 *peer_sid = xfrm_sid;
2670                 return 0;
2671         }
2672
2673         /* we don't need to check ss_initialized here since the only way both
2674          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2675          * security server was initialized and ss_initialized was true */
2676         if (!policydb.mls_enabled)
2677                 return 0;
2678
2679         read_lock(&policy_rwlock);
2680
2681         rc = -EINVAL;
2682         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2683         if (!nlbl_ctx) {
2684                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2685                        __func__, nlbl_sid);
2686                 goto out;
2687         }
2688         rc = -EINVAL;
2689         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2690         if (!xfrm_ctx) {
2691                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2692                        __func__, xfrm_sid);
2693                 goto out;
2694         }
2695         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2696         if (rc)
2697                 goto out;
2698
2699         /* at present NetLabel SIDs/labels really only carry MLS
2700          * information so if the MLS portion of the NetLabel SID
2701          * matches the MLS portion of the labeled XFRM SID/label
2702          * then pass along the XFRM SID as it is the most
2703          * expressive */
2704         *peer_sid = xfrm_sid;
2705 out:
2706         read_unlock(&policy_rwlock);
2707         return rc;
2708 }
2709
2710 static int get_classes_callback(void *k, void *d, void *args)
2711 {
2712         struct class_datum *datum = d;
2713         char *name = k, **classes = args;
2714         int value = datum->value - 1;
2715
2716         classes[value] = kstrdup(name, GFP_ATOMIC);
2717         if (!classes[value])
2718                 return -ENOMEM;
2719
2720         return 0;
2721 }
2722
2723 int security_get_classes(char ***classes, int *nclasses)
2724 {
2725         int rc;
2726
2727         read_lock(&policy_rwlock);
2728
2729         rc = -ENOMEM;
2730         *nclasses = policydb.p_classes.nprim;
2731         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2732         if (!*classes)
2733                 goto out;
2734
2735         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2736                         *classes);
2737         if (rc) {
2738                 int i;
2739                 for (i = 0; i < *nclasses; i++)
2740                         kfree((*classes)[i]);
2741                 kfree(*classes);
2742         }
2743
2744 out:
2745         read_unlock(&policy_rwlock);
2746         return rc;
2747 }
2748
2749 static int get_permissions_callback(void *k, void *d, void *args)
2750 {
2751         struct perm_datum *datum = d;
2752         char *name = k, **perms = args;
2753         int value = datum->value - 1;
2754
2755         perms[value] = kstrdup(name, GFP_ATOMIC);
2756         if (!perms[value])
2757                 return -ENOMEM;
2758
2759         return 0;
2760 }
2761
2762 int security_get_permissions(char *class, char ***perms, int *nperms)
2763 {
2764         int rc, i;
2765         struct class_datum *match;
2766
2767         read_lock(&policy_rwlock);
2768
2769         rc = -EINVAL;
2770         match = hashtab_search(policydb.p_classes.table, class);
2771         if (!match) {
2772                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2773                         __func__, class);
2774                 goto out;
2775         }
2776
2777         rc = -ENOMEM;
2778         *nperms = match->permissions.nprim;
2779         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2780         if (!*perms)
2781                 goto out;
2782
2783         if (match->comdatum) {
2784                 rc = hashtab_map(match->comdatum->permissions.table,
2785                                 get_permissions_callback, *perms);
2786                 if (rc)
2787                         goto err;
2788         }
2789
2790         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2791                         *perms);
2792         if (rc)
2793                 goto err;
2794
2795 out:
2796         read_unlock(&policy_rwlock);
2797         return rc;
2798
2799 err:
2800         read_unlock(&policy_rwlock);
2801         for (i = 0; i < *nperms; i++)
2802                 kfree((*perms)[i]);
2803         kfree(*perms);
2804         return rc;
2805 }
2806
2807 int security_get_reject_unknown(void)
2808 {
2809         return policydb.reject_unknown;
2810 }
2811
2812 int security_get_allow_unknown(void)
2813 {
2814         return policydb.allow_unknown;
2815 }
2816
2817 /**
2818  * security_policycap_supported - Check for a specific policy capability
2819  * @req_cap: capability
2820  *
2821  * Description:
2822  * This function queries the currently loaded policy to see if it supports the
2823  * capability specified by @req_cap.  Returns true (1) if the capability is
2824  * supported, false (0) if it isn't supported.
2825  *
2826  */
2827 int security_policycap_supported(unsigned int req_cap)
2828 {
2829         int rc;
2830
2831         read_lock(&policy_rwlock);
2832         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2833         read_unlock(&policy_rwlock);
2834
2835         return rc;
2836 }
2837
2838 struct selinux_audit_rule {
2839         u32 au_seqno;
2840         struct context au_ctxt;
2841 };
2842
2843 void selinux_audit_rule_free(void *vrule)
2844 {
2845         struct selinux_audit_rule *rule = vrule;
2846
2847         if (rule) {
2848                 context_destroy(&rule->au_ctxt);
2849                 kfree(rule);
2850         }
2851 }
2852
2853 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2854 {
2855         struct selinux_audit_rule *tmprule;
2856         struct role_datum *roledatum;
2857         struct type_datum *typedatum;
2858         struct user_datum *userdatum;
2859         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2860         int rc = 0;
2861
2862         *rule = NULL;
2863
2864         if (!ss_initialized)
2865                 return -EOPNOTSUPP;
2866
2867         switch (field) {
2868         case AUDIT_SUBJ_USER:
2869         case AUDIT_SUBJ_ROLE:
2870         case AUDIT_SUBJ_TYPE:
2871         case AUDIT_OBJ_USER:
2872         case AUDIT_OBJ_ROLE:
2873         case AUDIT_OBJ_TYPE:
2874                 /* only 'equals' and 'not equals' fit user, role, and type */
2875                 if (op != Audit_equal && op != Audit_not_equal)
2876                         return -EINVAL;
2877                 break;
2878         case AUDIT_SUBJ_SEN:
2879         case AUDIT_SUBJ_CLR:
2880         case AUDIT_OBJ_LEV_LOW:
2881         case AUDIT_OBJ_LEV_HIGH:
2882                 /* we do not allow a range, indicated by the presence of '-' */
2883                 if (strchr(rulestr, '-'))
2884                         return -EINVAL;
2885                 break;
2886         default:
2887                 /* only the above fields are valid */
2888                 return -EINVAL;
2889         }
2890
2891         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2892         if (!tmprule)
2893                 return -ENOMEM;
2894
2895         context_init(&tmprule->au_ctxt);
2896
2897         read_lock(&policy_rwlock);
2898
2899         tmprule->au_seqno = latest_granting;
2900
2901         switch (field) {
2902         case AUDIT_SUBJ_USER:
2903         case AUDIT_OBJ_USER:
2904                 rc = -EINVAL;
2905                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2906                 if (!userdatum)
2907                         goto out;
2908                 tmprule->au_ctxt.user = userdatum->value;
2909                 break;
2910         case AUDIT_SUBJ_ROLE:
2911         case AUDIT_OBJ_ROLE:
2912                 rc = -EINVAL;
2913                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2914                 if (!roledatum)
2915                         goto out;
2916                 tmprule->au_ctxt.role = roledatum->value;
2917                 break;
2918         case AUDIT_SUBJ_TYPE:
2919         case AUDIT_OBJ_TYPE:
2920                 rc = -EINVAL;
2921                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2922                 if (!typedatum)
2923                         goto out;
2924                 tmprule->au_ctxt.type = typedatum->value;
2925                 break;
2926         case AUDIT_SUBJ_SEN:
2927         case AUDIT_SUBJ_CLR:
2928         case AUDIT_OBJ_LEV_LOW:
2929         case AUDIT_OBJ_LEV_HIGH:
2930                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2931                 if (rc)
2932                         goto out;
2933                 break;
2934         }
2935         rc = 0;
2936 out:
2937         read_unlock(&policy_rwlock);
2938
2939         if (rc) {
2940                 selinux_audit_rule_free(tmprule);
2941                 tmprule = NULL;
2942         }
2943
2944         *rule = tmprule;
2945
2946         return rc;
2947 }
2948
2949 /* Check to see if the rule contains any selinux fields */
2950 int selinux_audit_rule_known(struct audit_krule *rule)
2951 {
2952         int i;
2953
2954         for (i = 0; i < rule->field_count; i++) {
2955                 struct audit_field *f = &rule->fields[i];
2956                 switch (f->type) {
2957                 case AUDIT_SUBJ_USER:
2958                 case AUDIT_SUBJ_ROLE:
2959                 case AUDIT_SUBJ_TYPE:
2960                 case AUDIT_SUBJ_SEN:
2961                 case AUDIT_SUBJ_CLR:
2962                 case AUDIT_OBJ_USER:
2963                 case AUDIT_OBJ_ROLE:
2964                 case AUDIT_OBJ_TYPE:
2965                 case AUDIT_OBJ_LEV_LOW:
2966                 case AUDIT_OBJ_LEV_HIGH:
2967                         return 1;
2968                 }
2969         }
2970
2971         return 0;
2972 }
2973
2974 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2975                              struct audit_context *actx)
2976 {
2977         struct context *ctxt;
2978         struct mls_level *level;
2979         struct selinux_audit_rule *rule = vrule;
2980         int match = 0;
2981
2982         if (unlikely(!rule)) {
2983                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
2984                 return -ENOENT;
2985         }
2986
2987         read_lock(&policy_rwlock);
2988
2989         if (rule->au_seqno < latest_granting) {
2990                 match = -ESTALE;
2991                 goto out;
2992         }
2993
2994         ctxt = sidtab_search(&sidtab, sid);
2995         if (unlikely(!ctxt)) {
2996                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
2997                           sid);
2998                 match = -ENOENT;
2999                 goto out;
3000         }
3001
3002         /* a field/op pair that is not caught here will simply fall through
3003            without a match */
3004         switch (field) {
3005         case AUDIT_SUBJ_USER:
3006         case AUDIT_OBJ_USER:
3007                 switch (op) {
3008                 case Audit_equal:
3009                         match = (ctxt->user == rule->au_ctxt.user);
3010                         break;
3011                 case Audit_not_equal:
3012                         match = (ctxt->user != rule->au_ctxt.user);
3013                         break;
3014                 }
3015                 break;
3016         case AUDIT_SUBJ_ROLE:
3017         case AUDIT_OBJ_ROLE:
3018                 switch (op) {
3019                 case Audit_equal:
3020                         match = (ctxt->role == rule->au_ctxt.role);
3021                         break;
3022                 case Audit_not_equal:
3023                         match = (ctxt->role != rule->au_ctxt.role);
3024                         break;
3025                 }
3026                 break;
3027         case AUDIT_SUBJ_TYPE:
3028         case AUDIT_OBJ_TYPE:
3029                 switch (op) {
3030                 case Audit_equal:
3031                         match = (ctxt->type == rule->au_ctxt.type);
3032                         break;
3033                 case Audit_not_equal:
3034                         match = (ctxt->type != rule->au_ctxt.type);
3035                         break;
3036                 }
3037                 break;
3038         case AUDIT_SUBJ_SEN:
3039         case AUDIT_SUBJ_CLR:
3040         case AUDIT_OBJ_LEV_LOW:
3041         case AUDIT_OBJ_LEV_HIGH:
3042                 level = ((field == AUDIT_SUBJ_SEN ||
3043                           field == AUDIT_OBJ_LEV_LOW) ?
3044                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3045                 switch (op) {
3046                 case Audit_equal:
3047                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3048                                              level);
3049                         break;
3050                 case Audit_not_equal:
3051                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3052                                               level);
3053                         break;
3054                 case Audit_lt:
3055                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3056                                                level) &&
3057                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3058                                                level));
3059                         break;
3060                 case Audit_le:
3061                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3062                                               level);
3063                         break;
3064                 case Audit_gt:
3065                         match = (mls_level_dom(level,
3066                                               &rule->au_ctxt.range.level[0]) &&
3067                                  !mls_level_eq(level,
3068                                                &rule->au_ctxt.range.level[0]));
3069                         break;
3070                 case Audit_ge:
3071                         match = mls_level_dom(level,
3072                                               &rule->au_ctxt.range.level[0]);
3073                         break;
3074                 }
3075         }
3076
3077 out:
3078         read_unlock(&policy_rwlock);
3079         return match;
3080 }
3081
3082 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3083
3084 static int aurule_avc_callback(u32 event)
3085 {
3086         int err = 0;
3087
3088         if (event == AVC_CALLBACK_RESET && aurule_callback)
3089                 err = aurule_callback();
3090         return err;
3091 }
3092
3093 static int __init aurule_init(void)
3094 {
3095         int err;
3096
3097         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3098         if (err)
3099                 panic("avc_add_callback() failed, error %d\n", err);
3100
3101         return err;
3102 }
3103 __initcall(aurule_init);
3104
3105 #ifdef CONFIG_NETLABEL
3106 /**
3107  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3108  * @secattr: the NetLabel packet security attributes
3109  * @sid: the SELinux SID
3110  *
3111  * Description:
3112  * Attempt to cache the context in @ctx, which was derived from the packet in
3113  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3114  * already been initialized.
3115  *
3116  */
3117 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3118                                       u32 sid)
3119 {
3120         u32 *sid_cache;
3121
3122         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3123         if (sid_cache == NULL)
3124                 return;
3125         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3126         if (secattr->cache == NULL) {
3127                 kfree(sid_cache);
3128                 return;
3129         }
3130
3131         *sid_cache = sid;
3132         secattr->cache->free = kfree;
3133         secattr->cache->data = sid_cache;
3134         secattr->flags |= NETLBL_SECATTR_CACHE;
3135 }
3136
3137 /**
3138  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3139  * @secattr: the NetLabel packet security attributes
3140  * @sid: the SELinux SID
3141  *
3142  * Description:
3143  * Convert the given NetLabel security attributes in @secattr into a
3144  * SELinux SID.  If the @secattr field does not contain a full SELinux
3145  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3146  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3147  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3148  * conversion for future lookups.  Returns zero on success, negative values on
3149  * failure.
3150  *
3151  */
3152 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3153                                    u32 *sid)
3154 {
3155         int rc;
3156         struct context *ctx;
3157         struct context ctx_new;
3158
3159         if (!ss_initialized) {
3160                 *sid = SECSID_NULL;
3161                 return 0;
3162         }
3163
3164         read_lock(&policy_rwlock);
3165
3166         if (secattr->flags & NETLBL_SECATTR_CACHE)
3167                 *sid = *(u32 *)secattr->cache->data;
3168         else if (secattr->flags & NETLBL_SECATTR_SECID)
3169                 *sid = secattr->attr.secid;
3170         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3171                 rc = -EIDRM;
3172                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3173                 if (ctx == NULL)
3174                         goto out;
3175
3176                 context_init(&ctx_new);
3177                 ctx_new.user = ctx->user;
3178                 ctx_new.role = ctx->role;
3179                 ctx_new.type = ctx->type;
3180                 mls_import_netlbl_lvl(&ctx_new, secattr);
3181                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3182                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3183                         if (rc)
3184                                 goto out;
3185                 }
3186                 rc = -EIDRM;
3187                 if (!mls_context_isvalid(&policydb, &ctx_new))
3188                         goto out_free;
3189
3190                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3191                 if (rc)
3192                         goto out_free;
3193
3194                 security_netlbl_cache_add(secattr, *sid);
3195
3196                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3197         } else
3198                 *sid = SECSID_NULL;
3199
3200         read_unlock(&policy_rwlock);
3201         return 0;
3202 out_free:
3203         ebitmap_destroy(&ctx_new.range.level[0].cat);
3204 out:
3205         read_unlock(&policy_rwlock);
3206         return rc;
3207 }
3208
3209 /**
3210  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3211  * @sid: the SELinux SID
3212  * @secattr: the NetLabel packet security attributes
3213  *
3214  * Description:
3215  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3216  * Returns zero on success, negative values on failure.
3217  *
3218  */
3219 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3220 {
3221         int rc;
3222         struct context *ctx;
3223
3224         if (!ss_initialized)
3225                 return 0;
3226
3227         read_lock(&policy_rwlock);
3228
3229         rc = -ENOENT;
3230         ctx = sidtab_search(&sidtab, sid);
3231         if (ctx == NULL)
3232                 goto out;
3233
3234         rc = -ENOMEM;
3235         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3236                                   GFP_ATOMIC);
3237         if (secattr->domain == NULL)
3238                 goto out;
3239
3240         secattr->attr.secid = sid;
3241         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3242         mls_export_netlbl_lvl(ctx, secattr);
3243         rc = mls_export_netlbl_cat(ctx, secattr);
3244 out:
3245         read_unlock(&policy_rwlock);
3246         return rc;
3247 }
3248 #endif /* CONFIG_NETLABEL */
3249
3250 /**
3251  * security_read_policy - read the policy.
3252  * @data: binary policy data
3253  * @len: length of data in bytes
3254  *
3255  */
3256 int security_read_policy(void **data, size_t *len)
3257 {
3258         int rc;
3259         struct policy_file fp;
3260
3261         if (!ss_initialized)
3262                 return -EINVAL;
3263
3264         *len = security_policydb_len();
3265
3266         *data = vmalloc_user(*len);
3267         if (!*data)
3268                 return -ENOMEM;
3269
3270         fp.data = *data;
3271         fp.len = *len;
3272
3273         read_lock(&policy_rwlock);
3274         rc = policydb_write(&policydb, &fp);
3275         read_unlock(&policy_rwlock);
3276
3277         if (rc)
3278                 return rc;
3279
3280         *len = (unsigned long)fp.data - (unsigned long)*data;
3281         return 0;
3282
3283 }