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