kernel/security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   5  *           James Morris <jmorris@redhat.com>
   6  *
   7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8  *
   9  *      Support for enhanced MLS infrastructure.
  10  *      Support for context based audit filters.
  11  *
  12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  13  *
  14  *      Added conditional policy language extensions
  15  *
  16  * Updated: Hewlett-Packard <paul@paul-moore.com>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <csellers@tresys.com>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <guido@trentalancia.com>
  30  *
  31  *  Added support for runtime switching of the policy type
  32  *
  33  * Copyright (C) 2008, 2009 NEC Corporation
  34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  38  *      This program is free software; you can redistribute it and/or modify
  39  *      it under the terms of the GNU General Public License as published by
  40  *      the Free Software Foundation, version 2.
  41  */
  42 #include <linux/kernel.h>
  43 #include <linux/slab.h>
  44 #include <linux/string.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/errno.h>
  48 #include <linux/in.h>
  49 #include <linux/sched.h>
  50 #include <linux/audit.h>
  51 #include <linux/mutex.h>
  52 #include <linux/selinux.h>
  53 #include <linux/flex_array.h>
  54 #include <linux/vmalloc.h>
  55 #include <net/netlabel.h>
  56
  57 #include "flask.h"
  58 #include "avc.h"
  59 #include "avc_ss.h"
  60 #include "security.h"
  61 #include "context.h"
  62 #include "policydb.h"
  63 #include "sidtab.h"
  64 #include "services.h"
  65 #include "conditional.h"
  66 #include "mls.h"
  67 #include "objsec.h"
  68 #include "netlabel.h"
  69 #include "xfrm.h"
  70 #include "ebitmap.h"
  71 #include "audit.h"
  72
  73 int selinux_policycap_netpeer;
  74 int selinux_policycap_openperm;
  75 int selinux_policycap_alwaysnetwork;
  76
  77 static DEFINE_RWLOCK(policy_rwlock);
  78
  79 static struct sidtab sidtab;
  80 struct policydb policydb;
  81 int ss_initialized;
  82
  83 /*
  84  * The largest sequence number that has been used when
  85  * providing an access decision to the access vector cache.
  86  * The sequence number only changes when a policy change
  87  * occurs.
  88  */
  89 static u32 latest_granting;
  90
  91 /* Forward declaration. */
  92 static int context_struct_to_string(struct context *context, char **scontext,
  93                                     u32 *scontext_len);
  94
  95 static void context_struct_compute_av(struct context *scontext,
  96                                         struct context *tcontext,
  97                                         u16 tclass,
  98                                         struct av_decision *avd,
  99                                         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         scontextp += 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
1226         mls_sid_to_context(context, &scontextp);
1227
1228         *scontextp = 0;
1229
1230         return 0;
1231 }
1232
1233 #include "initial_sid_to_string.h"
1234
1235 const char *security_get_initial_sid_context(u32 sid)
1236 {
1237         if (unlikely(sid > SECINITSID_NUM))
1238                 return NULL;
1239         return initial_sid_to_string[sid];
1240 }
1241
1242 static int security_sid_to_context_core(u32 sid, char **scontext,
1243                                         u32 *scontext_len, int force)
1244 {
1245         struct context *context;
1246         int rc = 0;
1247
1248         if (scontext)
1249                 *scontext = NULL;
1250         *scontext_len  = 0;
1251
1252         if (!ss_initialized) {
1253                 if (sid <= SECINITSID_NUM) {
1254                         char *scontextp;
1255
1256                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1257                         if (!scontext)
1258                                 goto out;
1259                         scontextp = kmemdup(initial_sid_to_string[sid],
1260                                             *scontext_len, GFP_ATOMIC);
1261                         if (!scontextp) {
1262                                 rc = -ENOMEM;
1263                                 goto out;
1264                         }
1265                         *scontext = scontextp;
1266                         goto out;
1267                 }
1268                 printk(KERN_ERR "SELinux: %s:  called before initial "
1269                        "load_policy on unknown SID %d\n", __func__, sid);
1270                 rc = -EINVAL;
1271                 goto out;
1272         }
1273         read_lock(&policy_rwlock);
1274         if (force)
1275                 context = sidtab_search_force(&sidtab, sid);
1276         else
1277                 context = sidtab_search(&sidtab, sid);
1278         if (!context) {
1279                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1280                         __func__, sid);
1281                 rc = -EINVAL;
1282                 goto out_unlock;
1283         }
1284         rc = context_struct_to_string(context, scontext, scontext_len);
1285 out_unlock:
1286         read_unlock(&policy_rwlock);
1287 out:
1288         return rc;
1289
1290 }
1291
1292 /**
1293  * security_sid_to_context - Obtain a context for a given SID.
1294  * @sid: security identifier, SID
1295  * @scontext: security context
1296  * @scontext_len: length in bytes
1297  *
1298  * Write the string representation of the context associated with @sid
1299  * into a dynamically allocated string of the correct size.  Set @scontext
1300  * to point to this string and set @scontext_len to the length of the string.
1301  */
1302 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1303 {
1304         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1305 }
1306
1307 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1308 {
1309         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1310 }
1311
1312 /*
1313  * Caveat:  Mutates scontext.
1314  */
1315 static int string_to_context_struct(struct policydb *pol,
1316                                     struct sidtab *sidtabp,
1317                                     char *scontext,
1318                                     u32 scontext_len,
1319                                     struct context *ctx,
1320                                     u32 def_sid)
1321 {
1322         struct role_datum *role;
1323         struct type_datum *typdatum;
1324         struct user_datum *usrdatum;
1325         char *scontextp, *p, oldc;
1326         int rc = 0;
1327
1328         context_init(ctx);
1329
1330         /* Parse the security context. */
1331
1332         rc = -EINVAL;
1333         scontextp = (char *) scontext;
1334
1335         /* Extract the user. */
1336         p = scontextp;
1337         while (*p && *p != ':')
1338                 p++;
1339
1340         if (*p == 0)
1341                 goto out;
1342
1343         *p++ = 0;
1344
1345         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1346         if (!usrdatum)
1347                 goto out;
1348
1349         ctx->user = usrdatum->value;
1350
1351         /* Extract role. */
1352         scontextp = p;
1353         while (*p && *p != ':')
1354                 p++;
1355
1356         if (*p == 0)
1357                 goto out;
1358
1359         *p++ = 0;
1360
1361         role = hashtab_search(pol->p_roles.table, scontextp);
1362         if (!role)
1363                 goto out;
1364         ctx->role = role->value;
1365
1366         /* Extract type. */
1367         scontextp = p;
1368         while (*p && *p != ':')
1369                 p++;
1370         oldc = *p;
1371         *p++ = 0;
1372
1373         typdatum = hashtab_search(pol->p_types.table, scontextp);
1374         if (!typdatum || typdatum->attribute)
1375                 goto out;
1376
1377         ctx->type = typdatum->value;
1378
1379         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1380         if (rc)
1381                 goto out;
1382
1383         rc = -EINVAL;
1384         if ((p - scontext) < scontext_len)
1385                 goto out;
1386
1387         /* Check the validity of the new context. */
1388         if (!policydb_context_isvalid(pol, ctx))
1389                 goto out;
1390         rc = 0;
1391 out:
1392         if (rc)
1393                 context_destroy(ctx);
1394         return rc;
1395 }
1396
1397 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1398                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1399                                         int force)
1400 {
1401         char *scontext2, *str = NULL;
1402         struct context context;
1403         int rc = 0;
1404
1405         /* An empty security context is never valid. */
1406         if (!scontext_len)
1407                 return -EINVAL;
1408
1409         if (!ss_initialized) {
1410                 int i;
1411
1412                 for (i = 1; i < SECINITSID_NUM; i++) {
1413                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1414                                 *sid = i;
1415                                 return 0;
1416                         }
1417                 }
1418                 *sid = SECINITSID_KERNEL;
1419                 return 0;
1420         }
1421         *sid = SECSID_NULL;
1422
1423         /* Copy the string so that we can modify the copy as we parse it. */
1424         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1425         if (!scontext2)
1426                 return -ENOMEM;
1427         memcpy(scontext2, scontext, scontext_len);
1428         scontext2[scontext_len] = 0;
1429
1430         if (force) {
1431                 /* Save another copy for storing in uninterpreted form */
1432                 rc = -ENOMEM;
1433                 str = kstrdup(scontext2, gfp_flags);
1434                 if (!str)
1435                         goto out;
1436         }
1437
1438         read_lock(&policy_rwlock);
1439         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1440                                       scontext_len, &context, def_sid);
1441         if (rc == -EINVAL && force) {
1442                 context.str = str;
1443                 context.len = scontext_len;
1444                 str = NULL;
1445         } else if (rc)
1446                 goto out_unlock;
1447         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1448         context_destroy(&context);
1449 out_unlock:
1450         read_unlock(&policy_rwlock);
1451 out:
1452         kfree(scontext2);
1453         kfree(str);
1454         return rc;
1455 }
1456
1457 /**
1458  * security_context_to_sid - Obtain a SID for a given security context.
1459  * @scontext: security context
1460  * @scontext_len: length in bytes
1461  * @sid: security identifier, SID
1462  * @gfp: context for the allocation
1463  *
1464  * Obtains a SID associated with the security context that
1465  * has the string representation specified by @scontext.
1466  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1467  * memory is available, or 0 on success.
1468  */
1469 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1470                             gfp_t gfp)
1471 {
1472         return security_context_to_sid_core(scontext, scontext_len,
1473                                             sid, SECSID_NULL, gfp, 0);
1474 }
1475
1476 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1477 {
1478         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1479 }
1480
1481 /**
1482  * security_context_to_sid_default - Obtain a SID for a given security context,
1483  * falling back to specified default if needed.
1484  *
1485  * @scontext: security context
1486  * @scontext_len: length in bytes
1487  * @sid: security identifier, SID
1488  * @def_sid: default SID to assign on error
1489  *
1490  * Obtains a SID associated with the security context that
1491  * has the string representation specified by @scontext.
1492  * The default SID is passed to the MLS layer to be used to allow
1493  * kernel labeling of the MLS field if the MLS field is not present
1494  * (for upgrading to MLS without full relabel).
1495  * Implicitly forces adding of the context even if it cannot be mapped yet.
1496  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1497  * memory is available, or 0 on success.
1498  */
1499 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1500                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1501 {
1502         return security_context_to_sid_core(scontext, scontext_len,
1503                                             sid, def_sid, gfp_flags, 1);
1504 }
1505
1506 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1507                                   u32 *sid)
1508 {
1509         return security_context_to_sid_core(scontext, scontext_len,
1510                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1511 }
1512
1513 static int compute_sid_handle_invalid_context(
1514         struct context *scontext,
1515         struct context *tcontext,
1516         u16 tclass,
1517         struct context *newcontext)
1518 {
1519         char *s = NULL, *t = NULL, *n = NULL;
1520         u32 slen, tlen, nlen;
1521
1522         if (context_struct_to_string(scontext, &s, &slen))
1523                 goto out;
1524         if (context_struct_to_string(tcontext, &t, &tlen))
1525                 goto out;
1526         if (context_struct_to_string(newcontext, &n, &nlen))
1527                 goto out;
1528         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1529                   "op=security_compute_sid invalid_context=%s"
1530                   " scontext=%s"
1531                   " tcontext=%s"
1532                   " tclass=%s",
1533                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1534 out:
1535         kfree(s);
1536         kfree(t);
1537         kfree(n);
1538         if (!selinux_enforcing)
1539                 return 0;
1540         return -EACCES;
1541 }
1542
1543 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1544                                   u32 stype, u32 ttype, u16 tclass,
1545                                   const char *objname)
1546 {
1547         struct filename_trans ft;
1548         struct filename_trans_datum *otype;
1549
1550         /*
1551          * Most filename trans rules are going to live in specific directories
1552          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1553          * if the ttype does not contain any rules.
1554          */
1555         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1556                 return;
1557
1558         ft.stype = stype;
1559         ft.ttype = ttype;
1560         ft.tclass = tclass;
1561         ft.name = objname;
1562
1563         otype = hashtab_search(p->filename_trans, &ft);
1564         if (otype)
1565                 newcontext->type = otype->otype;
1566 }
1567
1568 static int security_compute_sid(u32 ssid,
1569                                 u32 tsid,
1570                                 u16 orig_tclass,
1571                                 u32 specified,
1572                                 const char *objname,
1573                                 u32 *out_sid,
1574                                 bool kern)
1575 {
1576         struct class_datum *cladatum = NULL;
1577         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1578         struct role_trans *roletr = NULL;
1579         struct avtab_key avkey;
1580         struct avtab_datum *avdatum;
1581         struct avtab_node *node;
1582         u16 tclass;
1583         int rc = 0;
1584         bool sock;
1585
1586         if (!ss_initialized) {
1587                 switch (orig_tclass) {
1588                 case SECCLASS_PROCESS: /* kernel value */
1589                         *out_sid = ssid;
1590                         break;
1591                 default:
1592                         *out_sid = tsid;
1593                         break;
1594                 }
1595                 goto out;
1596         }
1597
1598         context_init(&newcontext);
1599
1600         read_lock(&policy_rwlock);
1601
1602         if (kern) {
1603                 tclass = unmap_class(orig_tclass);
1604                 sock = security_is_socket_class(orig_tclass);
1605         } else {
1606                 tclass = orig_tclass;
1607                 sock = security_is_socket_class(map_class(tclass));
1608         }
1609
1610         scontext = sidtab_search(&sidtab, ssid);
1611         if (!scontext) {
1612                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1613                        __func__, ssid);
1614                 rc = -EINVAL;
1615                 goto out_unlock;
1616         }
1617         tcontext = sidtab_search(&sidtab, tsid);
1618         if (!tcontext) {
1619                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1620                        __func__, tsid);
1621                 rc = -EINVAL;
1622                 goto out_unlock;
1623         }
1624
1625         if (tclass && tclass <= policydb.p_classes.nprim)
1626                 cladatum = policydb.class_val_to_struct[tclass - 1];
1627
1628         /* Set the user identity. */
1629         switch (specified) {
1630         case AVTAB_TRANSITION:
1631         case AVTAB_CHANGE:
1632                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1633                         newcontext.user = tcontext->user;
1634                 } else {
1635                         /* notice this gets both DEFAULT_SOURCE and unset */
1636                         /* Use the process user identity. */
1637                         newcontext.user = scontext->user;
1638                 }
1639                 break;
1640         case AVTAB_MEMBER:
1641                 /* Use the related object owner. */
1642                 newcontext.user = tcontext->user;
1643                 break;
1644         }
1645
1646         /* Set the role to default values. */
1647         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1648                 newcontext.role = scontext->role;
1649         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1650                 newcontext.role = tcontext->role;
1651         } else {
1652                 if ((tclass == policydb.process_class) || (sock == true))
1653                         newcontext.role = scontext->role;
1654                 else
1655                         newcontext.role = OBJECT_R_VAL;
1656         }
1657
1658         /* Set the type to default values. */
1659         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1660                 newcontext.type = scontext->type;
1661         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1662                 newcontext.type = tcontext->type;
1663         } else {
1664                 if ((tclass == policydb.process_class) || (sock == true)) {
1665                         /* Use the type of process. */
1666                         newcontext.type = scontext->type;
1667                 } else {
1668                         /* Use the type of the related object. */
1669                         newcontext.type = tcontext->type;
1670                 }
1671         }
1672
1673         /* Look for a type transition/member/change rule. */
1674         avkey.source_type = scontext->type;
1675         avkey.target_type = tcontext->type;
1676         avkey.target_class = tclass;
1677         avkey.specified = specified;
1678         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1679
1680         /* If no permanent rule, also check for enabled conditional rules */
1681         if (!avdatum) {
1682                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1683                 for (; node; node = avtab_search_node_next(node, specified)) {
1684                         if (node->key.specified & AVTAB_ENABLED) {
1685                                 avdatum = &node->datum;
1686                                 break;
1687                         }
1688                 }
1689         }
1690
1691         if (avdatum) {
1692                 /* Use the type from the type transition/member/change rule. */
1693                 newcontext.type = avdatum->u.data;
1694         }
1695
1696         /* if we have a objname this is a file trans check so check those rules */
1697         if (objname)
1698                 filename_compute_type(&policydb, &newcontext, scontext->type,
1699                                       tcontext->type, tclass, objname);
1700
1701         /* Check for class-specific changes. */
1702         if (specified & AVTAB_TRANSITION) {
1703                 /* Look for a role transition rule. */
1704                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1705                         if ((roletr->role == scontext->role) &&
1706                             (roletr->type == tcontext->type) &&
1707                             (roletr->tclass == tclass)) {
1708                                 /* Use the role transition rule. */
1709                                 newcontext.role = roletr->new_role;
1710                                 break;
1711                         }
1712                 }
1713         }
1714
1715         /* Set the MLS attributes.
1716            This is done last because it may allocate memory. */
1717         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1718                              &newcontext, sock);
1719         if (rc)
1720                 goto out_unlock;
1721
1722         /* Check the validity of the context. */
1723         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1724                 rc = compute_sid_handle_invalid_context(scontext,
1725                                                         tcontext,
1726                                                         tclass,
1727                                                         &newcontext);
1728                 if (rc)
1729                         goto out_unlock;
1730         }
1731         /* Obtain the sid for the context. */
1732         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1733 out_unlock:
1734         read_unlock(&policy_rwlock);
1735         context_destroy(&newcontext);
1736 out:
1737         return rc;
1738 }
1739
1740 /**
1741  * security_transition_sid - Compute the SID for a new subject/object.
1742  * @ssid: source security identifier
1743  * @tsid: target security identifier
1744  * @tclass: target security class
1745  * @out_sid: security identifier for new subject/object
1746  *
1747  * Compute a SID to use for labeling a new subject or object in the
1748  * class @tclass based on a SID pair (@ssid, @tsid).
1749  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1750  * if insufficient memory is available, or %0 if the new SID was
1751  * computed successfully.
1752  */
1753 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1754                             const struct qstr *qstr, u32 *out_sid)
1755 {
1756         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1757                                     qstr ? qstr->name : NULL, out_sid, true);
1758 }
1759
1760 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1761                                  const char *objname, u32 *out_sid)
1762 {
1763         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1764                                     objname, out_sid, false);
1765 }
1766
1767 /**
1768  * security_member_sid - Compute the SID for member selection.
1769  * @ssid: source security identifier
1770  * @tsid: target security identifier
1771  * @tclass: target security class
1772  * @out_sid: security identifier for selected member
1773  *
1774  * Compute a SID to use when selecting a member of a polyinstantiated
1775  * object of class @tclass based on a SID pair (@ssid, @tsid).
1776  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1777  * if insufficient memory is available, or %0 if the SID was
1778  * computed successfully.
1779  */
1780 int security_member_sid(u32 ssid,
1781                         u32 tsid,
1782                         u16 tclass,
1783                         u32 *out_sid)
1784 {
1785         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1786                                     out_sid, false);
1787 }
1788
1789 /**
1790  * security_change_sid - Compute the SID for object relabeling.
1791  * @ssid: source security identifier
1792  * @tsid: target security identifier
1793  * @tclass: target security class
1794  * @out_sid: security identifier for selected member
1795  *
1796  * Compute a SID to use for relabeling an object of class @tclass
1797  * based on a SID pair (@ssid, @tsid).
1798  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1799  * if insufficient memory is available, or %0 if the SID was
1800  * computed successfully.
1801  */
1802 int security_change_sid(u32 ssid,
1803                         u32 tsid,
1804                         u16 tclass,
1805                         u32 *out_sid)
1806 {
1807         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1808                                     out_sid, false);
1809 }
1810
1811 /* Clone the SID into the new SID table. */
1812 static int clone_sid(u32 sid,
1813                      struct context *context,
1814                      void *arg)
1815 {
1816         struct sidtab *s = arg;
1817
1818         if (sid > SECINITSID_NUM)
1819                 return sidtab_insert(s, sid, context);
1820         else
1821                 return 0;
1822 }
1823
1824 static inline int convert_context_handle_invalid_context(struct context *context)
1825 {
1826         char *s;
1827         u32 len;
1828
1829         if (selinux_enforcing)
1830                 return -EINVAL;
1831
1832         if (!context_struct_to_string(context, &s, &len)) {
1833                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1834                 kfree(s);
1835         }
1836         return 0;
1837 }
1838
1839 struct convert_context_args {
1840         struct policydb *oldp;
1841         struct policydb *newp;
1842 };
1843
1844 /*
1845  * Convert the values in the security context
1846  * structure `c' from the values specified
1847  * in the policy `p->oldp' to the values specified
1848  * in the policy `p->newp'.  Verify that the
1849  * context is valid under the new policy.
1850  */
1851 static int convert_context(u32 key,
1852                            struct context *c,
1853                            void *p)
1854 {
1855         struct convert_context_args *args;
1856         struct context oldc;
1857         struct ocontext *oc;
1858         struct mls_range *range;
1859         struct role_datum *role;
1860         struct type_datum *typdatum;
1861         struct user_datum *usrdatum;
1862         char *s;
1863         u32 len;
1864         int rc = 0;
1865
1866         if (key <= SECINITSID_NUM)
1867                 goto out;
1868
1869         args = p;
1870
1871         if (c->str) {
1872                 struct context ctx;
1873
1874                 rc = -ENOMEM;
1875                 s = kstrdup(c->str, GFP_KERNEL);
1876                 if (!s)
1877                         goto out;
1878
1879                 rc = string_to_context_struct(args->newp, NULL, s,
1880                                               c->len, &ctx, SECSID_NULL);
1881                 kfree(s);
1882                 if (!rc) {
1883                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1884                                c->str);
1885                         /* Replace string with mapped representation. */
1886                         kfree(c->str);
1887                         memcpy(c, &ctx, sizeof(*c));
1888                         goto out;
1889                 } else if (rc == -EINVAL) {
1890                         /* Retain string representation for later mapping. */
1891                         rc = 0;
1892                         goto out;
1893                 } else {
1894                         /* Other error condition, e.g. ENOMEM. */
1895                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1896                                c->str, -rc);
1897                         goto out;
1898                 }
1899         }
1900
1901         rc = context_cpy(&oldc, c);
1902         if (rc)
1903                 goto out;
1904
1905         /* Convert the user. */
1906         rc = -EINVAL;
1907         usrdatum = hashtab_search(args->newp->p_users.table,
1908                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1909         if (!usrdatum)
1910                 goto bad;
1911         c->user = usrdatum->value;
1912
1913         /* Convert the role. */
1914         rc = -EINVAL;
1915         role = hashtab_search(args->newp->p_roles.table,
1916                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1917         if (!role)
1918                 goto bad;
1919         c->role = role->value;
1920
1921         /* Convert the type. */
1922         rc = -EINVAL;
1923         typdatum = hashtab_search(args->newp->p_types.table,
1924                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1925         if (!typdatum)
1926                 goto bad;
1927         c->type = typdatum->value;
1928
1929         /* Convert the MLS fields if dealing with MLS policies */
1930         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1931                 rc = mls_convert_context(args->oldp, args->newp, c);
1932                 if (rc)
1933                         goto bad;
1934         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1935                 /*
1936                  * Switching between MLS and non-MLS policy:
1937                  * free any storage used by the MLS fields in the
1938                  * context for all existing entries in the sidtab.
1939                  */
1940                 mls_context_destroy(c);
1941         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1942                 /*
1943                  * Switching between non-MLS and MLS policy:
1944                  * ensure that the MLS fields of the context for all
1945                  * existing entries in the sidtab are filled in with a
1946                  * suitable default value, likely taken from one of the
1947                  * initial SIDs.
1948                  */
1949                 oc = args->newp->ocontexts[OCON_ISID];
1950                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1951                         oc = oc->next;
1952                 rc = -EINVAL;
1953                 if (!oc) {
1954                         printk(KERN_ERR "SELinux:  unable to look up"
1955                                 " the initial SIDs list\n");
1956                         goto bad;
1957                 }
1958                 range = &oc->context[0].range;
1959                 rc = mls_range_set(c, range);
1960                 if (rc)
1961                         goto bad;
1962         }
1963
1964         /* Check the validity of the new context. */
1965         if (!policydb_context_isvalid(args->newp, c)) {
1966                 rc = convert_context_handle_invalid_context(&oldc);
1967                 if (rc)
1968                         goto bad;
1969         }
1970
1971         context_destroy(&oldc);
1972
1973         rc = 0;
1974 out:
1975         return rc;
1976 bad:
1977         /* Map old representation to string and save it. */
1978         rc = context_struct_to_string(&oldc, &s, &len);
1979         if (rc)
1980                 return rc;
1981         context_destroy(&oldc);
1982         context_destroy(c);
1983         c->str = s;
1984         c->len = len;
1985         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1986                c->str);
1987         rc = 0;
1988         goto out;
1989 }
1990
1991 static void security_load_policycaps(void)
1992 {
1993         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1994                                                   POLICYDB_CAPABILITY_NETPEER);
1995         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1996                                                   POLICYDB_CAPABILITY_OPENPERM);
1997         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1998                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1999 }
2000
2001 static int security_preserve_bools(struct policydb *p);
2002
2003 /**
2004  * security_load_policy - Load a security policy configuration.
2005  * @data: binary policy data
2006  * @len: length of data in bytes
2007  *
2008  * Load a new set of security policy configuration data,
2009  * validate it and convert the SID table as necessary.
2010  * This function will flush the access vector cache after
2011  * loading the new policy.
2012  */
2013 int security_load_policy(void *data, size_t len)
2014 {
2015         struct policydb *oldpolicydb, *newpolicydb;
2016         struct sidtab oldsidtab, newsidtab;
2017         struct selinux_mapping *oldmap, *map = NULL;
2018         struct convert_context_args args;
2019         u32 seqno;
2020         u16 map_size;
2021         int rc = 0;
2022         struct policy_file file = { data, len }, *fp = &file;
2023
2024         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2025         if (!oldpolicydb) {
2026                 rc = -ENOMEM;
2027                 goto out;
2028         }
2029         newpolicydb = oldpolicydb + 1;
2030
2031         if (!ss_initialized) {
2032                 avtab_cache_init();
2033                 rc = policydb_read(&policydb, fp);
2034                 if (rc) {
2035                         avtab_cache_destroy();
2036                         goto out;
2037                 }
2038
2039                 policydb.len = len;
2040                 rc = selinux_set_mapping(&policydb, secclass_map,
2041                                          &current_mapping,
2042                                          &current_mapping_size);
2043                 if (rc) {
2044                         policydb_destroy(&policydb);
2045                         avtab_cache_destroy();
2046                         goto out;
2047                 }
2048
2049                 rc = policydb_load_isids(&policydb, &sidtab);
2050                 if (rc) {
2051                         policydb_destroy(&policydb);
2052                         avtab_cache_destroy();
2053                         goto out;
2054                 }
2055
2056                 security_load_policycaps();
2057                 ss_initialized = 1;
2058                 seqno = ++latest_granting;
2059                 selinux_complete_init();
2060                 avc_ss_reset(seqno);
2061                 selnl_notify_policyload(seqno);
2062                 selinux_status_update_policyload(seqno);
2063                 selinux_netlbl_cache_invalidate();
2064                 selinux_xfrm_notify_policyload();
2065                 goto out;
2066         }
2067
2068 #if 0
2069         sidtab_hash_eval(&sidtab, "sids");
2070 #endif
2071
2072         rc = policydb_read(newpolicydb, fp);
2073         if (rc)
2074                 goto out;
2075
2076         newpolicydb->len = len;
2077         /* If switching between different policy types, log MLS status */
2078         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2079                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2080         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2081                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2082
2083         rc = policydb_load_isids(newpolicydb, &newsidtab);
2084         if (rc) {
2085                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2086                 policydb_destroy(newpolicydb);
2087                 goto out;
2088         }
2089
2090         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2091         if (rc)
2092                 goto err;
2093
2094         rc = security_preserve_bools(newpolicydb);
2095         if (rc) {
2096                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2097                 goto err;
2098         }
2099
2100         /* Clone the SID table. */
2101         sidtab_shutdown(&sidtab);
2102
2103         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2104         if (rc)
2105                 goto err;
2106
2107         /*
2108          * Convert the internal representations of contexts
2109          * in the new SID table.
2110          */
2111         args.oldp = &policydb;
2112         args.newp = newpolicydb;
2113         rc = sidtab_map(&newsidtab, convert_context, &args);
2114         if (rc) {
2115                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2116                         " representation of contexts in the new SID"
2117                         " table\n");
2118                 goto err;
2119         }
2120
2121         /* Save the old policydb and SID table to free later. */
2122         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2123         sidtab_set(&oldsidtab, &sidtab);
2124
2125         /* Install the new policydb and SID table. */
2126         write_lock_irq(&policy_rwlock);
2127         memcpy(&policydb, newpolicydb, sizeof(policydb));
2128         sidtab_set(&sidtab, &newsidtab);
2129         security_load_policycaps();
2130         oldmap = current_mapping;
2131         current_mapping = map;
2132         current_mapping_size = map_size;
2133         seqno = ++latest_granting;
2134         write_unlock_irq(&policy_rwlock);
2135
2136         /* Free the old policydb and SID table. */
2137         policydb_destroy(oldpolicydb);
2138         sidtab_destroy(&oldsidtab);
2139         kfree(oldmap);
2140
2141         avc_ss_reset(seqno);
2142         selnl_notify_policyload(seqno);
2143         selinux_status_update_policyload(seqno);
2144         selinux_netlbl_cache_invalidate();
2145         selinux_xfrm_notify_policyload();
2146
2147         rc = 0;
2148         goto out;
2149
2150 err:
2151         kfree(map);
2152         sidtab_destroy(&newsidtab);
2153         policydb_destroy(newpolicydb);
2154
2155 out:
2156         kfree(oldpolicydb);
2157         return rc;
2158 }
2159
2160 size_t security_policydb_len(void)
2161 {
2162         size_t len;
2163
2164         read_lock(&policy_rwlock);
2165         len = policydb.len;
2166         read_unlock(&policy_rwlock);
2167
2168         return len;
2169 }
2170
2171 /**
2172  * security_port_sid - Obtain the SID for a port.
2173  * @protocol: protocol number
2174  * @port: port number
2175  * @out_sid: security identifier
2176  */
2177 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2178 {
2179         struct ocontext *c;
2180         int rc = 0;
2181
2182         read_lock(&policy_rwlock);
2183
2184         c = policydb.ocontexts[OCON_PORT];
2185         while (c) {
2186                 if (c->u.port.protocol == protocol &&
2187                     c->u.port.low_port <= port &&
2188                     c->u.port.high_port >= port)
2189                         break;
2190                 c = c->next;
2191         }
2192
2193         if (c) {
2194                 if (!c->sid[0]) {
2195                         rc = sidtab_context_to_sid(&sidtab,
2196                                                    &c->context[0],
2197                                                    &c->sid[0]);
2198                         if (rc)
2199                                 goto out;
2200                 }
2201                 *out_sid = c->sid[0];
2202         } else {
2203                 *out_sid = SECINITSID_PORT;
2204         }
2205
2206 out:
2207         read_unlock(&policy_rwlock);
2208         return rc;
2209 }
2210
2211 /**
2212  * security_netif_sid - Obtain the SID for a network interface.
2213  * @name: interface name
2214  * @if_sid: interface SID
2215  */
2216 int security_netif_sid(char *name, u32 *if_sid)
2217 {
2218         int rc = 0;
2219         struct ocontext *c;
2220
2221         read_lock(&policy_rwlock);
2222
2223         c = policydb.ocontexts[OCON_NETIF];
2224         while (c) {
2225                 if (strcmp(name, c->u.name) == 0)
2226                         break;
2227                 c = c->next;
2228         }
2229
2230         if (c) {
2231                 if (!c->sid[0] || !c->sid[1]) {
2232                         rc = sidtab_context_to_sid(&sidtab,
2233                                                   &c->context[0],
2234                                                   &c->sid[0]);
2235                         if (rc)
2236                                 goto out;
2237                         rc = sidtab_context_to_sid(&sidtab,
2238                                                    &c->context[1],
2239                                                    &c->sid[1]);
2240                         if (rc)
2241                                 goto out;
2242                 }
2243                 *if_sid = c->sid[0];
2244         } else
2245                 *if_sid = SECINITSID_NETIF;
2246
2247 out:
2248         read_unlock(&policy_rwlock);
2249         return rc;
2250 }
2251
2252 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2253 {
2254         int i, fail = 0;
2255
2256         for (i = 0; i < 4; i++)
2257                 if (addr[i] != (input[i] & mask[i])) {
2258                         fail = 1;
2259                         break;
2260                 }
2261
2262         return !fail;
2263 }
2264
2265 /**
2266  * security_node_sid - Obtain the SID for a node (host).
2267  * @domain: communication domain aka address family
2268  * @addrp: address
2269  * @addrlen: address length in bytes
2270  * @out_sid: security identifier
2271  */
2272 int security_node_sid(u16 domain,
2273                       void *addrp,
2274                       u32 addrlen,
2275                       u32 *out_sid)
2276 {
2277         int rc;
2278         struct ocontext *c;
2279
2280         read_lock(&policy_rwlock);
2281
2282         switch (domain) {
2283         case AF_INET: {
2284                 u32 addr;
2285
2286                 rc = -EINVAL;
2287                 if (addrlen != sizeof(u32))
2288                         goto out;
2289
2290                 addr = *((u32 *)addrp);
2291
2292                 c = policydb.ocontexts[OCON_NODE];
2293                 while (c) {
2294                         if (c->u.node.addr == (addr & c->u.node.mask))
2295                                 break;
2296                         c = c->next;
2297                 }
2298                 break;
2299         }
2300
2301         case AF_INET6:
2302                 rc = -EINVAL;
2303                 if (addrlen != sizeof(u64) * 2)
2304                         goto out;
2305                 c = policydb.ocontexts[OCON_NODE6];
2306                 while (c) {
2307                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2308                                                 c->u.node6.mask))
2309                                 break;
2310                         c = c->next;
2311                 }
2312                 break;
2313
2314         default:
2315                 rc = 0;
2316                 *out_sid = SECINITSID_NODE;
2317                 goto out;
2318         }
2319
2320         if (c) {
2321                 if (!c->sid[0]) {
2322                         rc = sidtab_context_to_sid(&sidtab,
2323                                                    &c->context[0],
2324                                                    &c->sid[0]);
2325                         if (rc)
2326                                 goto out;
2327                 }
2328                 *out_sid = c->sid[0];
2329         } else {
2330                 *out_sid = SECINITSID_NODE;
2331         }
2332
2333         rc = 0;
2334 out:
2335         read_unlock(&policy_rwlock);
2336         return rc;
2337 }
2338
2339 #define SIDS_NEL 25
2340
2341 /**
2342  * security_get_user_sids - Obtain reachable SIDs for a user.
2343  * @fromsid: starting SID
2344  * @username: username
2345  * @sids: array of reachable SIDs for user
2346  * @nel: number of elements in @sids
2347  *
2348  * Generate the set of SIDs for legal security contexts
2349  * for a given user that can be reached by @fromsid.
2350  * Set *@sids to point to a dynamically allocated
2351  * array containing the set of SIDs.  Set *@nel to the
2352  * number of elements in the array.
2353  */
2354
2355 int security_get_user_sids(u32 fromsid,
2356                            char *username,
2357                            u32 **sids,
2358                            u32 *nel)
2359 {
2360         struct context *fromcon, usercon;
2361         u32 *mysids = NULL, *mysids2, sid;
2362         u32 mynel = 0, maxnel = SIDS_NEL;
2363         struct user_datum *user;
2364         struct role_datum *role;
2365         struct ebitmap_node *rnode, *tnode;
2366         int rc = 0, i, j;
2367
2368         *sids = NULL;
2369         *nel = 0;
2370
2371         if (!ss_initialized)
2372                 goto out;
2373
2374         read_lock(&policy_rwlock);
2375
2376         context_init(&usercon);
2377
2378         rc = -EINVAL;
2379         fromcon = sidtab_search(&sidtab, fromsid);
2380         if (!fromcon)
2381                 goto out_unlock;
2382
2383         rc = -EINVAL;
2384         user = hashtab_search(policydb.p_users.table, username);
2385         if (!user)
2386                 goto out_unlock;
2387
2388         usercon.user = user->value;
2389
2390         rc = -ENOMEM;
2391         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2392         if (!mysids)
2393                 goto out_unlock;
2394
2395         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2396                 role = policydb.role_val_to_struct[i];
2397                 usercon.role = i + 1;
2398                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2399                         usercon.type = j + 1;
2400
2401                         if (mls_setup_user_range(fromcon, user, &usercon))
2402                                 continue;
2403
2404                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2405                         if (rc)
2406                                 goto out_unlock;
2407                         if (mynel < maxnel) {
2408                                 mysids[mynel++] = sid;
2409                         } else {
2410                                 rc = -ENOMEM;
2411                                 maxnel += SIDS_NEL;
2412                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2413                                 if (!mysids2)
2414                                         goto out_unlock;
2415                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2416                                 kfree(mysids);
2417                                 mysids = mysids2;
2418                                 mysids[mynel++] = sid;
2419                         }
2420                 }
2421         }
2422         rc = 0;
2423 out_unlock:
2424         read_unlock(&policy_rwlock);
2425         if (rc || !mynel) {
2426                 kfree(mysids);
2427                 goto out;
2428         }
2429
2430         rc = -ENOMEM;
2431         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2432         if (!mysids2) {
2433                 kfree(mysids);
2434                 goto out;
2435         }
2436         for (i = 0, j = 0; i < mynel; i++) {
2437                 struct av_decision dummy_avd;
2438                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2439                                           SECCLASS_PROCESS, /* kernel value */
2440                                           PROCESS__TRANSITION, AVC_STRICT,
2441                                           &dummy_avd);
2442                 if (!rc)
2443                         mysids2[j++] = mysids[i];
2444                 cond_resched();
2445         }
2446         rc = 0;
2447         kfree(mysids);
2448         *sids = mysids2;
2449         *nel = j;
2450 out:
2451         return rc;
2452 }
2453
2454 /**
2455  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2456  * @fstype: filesystem type
2457  * @path: path from root of mount
2458  * @sclass: file security class
2459  * @sid: SID for path
2460  *
2461  * Obtain a SID to use for a file in a filesystem that
2462  * cannot support xattr or use a fixed labeling behavior like
2463  * transition SIDs or task SIDs.
2464  *
2465  * The caller must acquire the policy_rwlock before calling this function.
2466  */
2467 static inline int __security_genfs_sid(const char *fstype,
2468                                        char *path,
2469                                        u16 orig_sclass,
2470                                        u32 *sid)
2471 {
2472         int len;
2473         u16 sclass;
2474         struct genfs *genfs;
2475         struct ocontext *c;
2476         int rc, cmp = 0;
2477
2478         while (path[0] == '/' && path[1] == '/')
2479                 path++;
2480
2481         sclass = unmap_class(orig_sclass);
2482         *sid = SECINITSID_UNLABELED;
2483
2484         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2485                 cmp = strcmp(fstype, genfs->fstype);
2486                 if (cmp <= 0)
2487                         break;
2488         }
2489
2490         rc = -ENOENT;
2491         if (!genfs || cmp)
2492                 goto out;
2493
2494         for (c = genfs->head; c; c = c->next) {
2495                 len = strlen(c->u.name);
2496                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2497                     (strncmp(c->u.name, path, len) == 0))
2498                         break;
2499         }
2500
2501         rc = -ENOENT;
2502         if (!c)
2503                 goto out;
2504
2505         if (!c->sid[0]) {
2506                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2507                 if (rc)
2508                         goto out;
2509         }
2510
2511         *sid = c->sid[0];
2512         rc = 0;
2513 out:
2514         return rc;
2515 }
2516
2517 /**
2518  * security_genfs_sid - Obtain a SID for a file in a filesystem
2519  * @fstype: filesystem type
2520  * @path: path from root of mount
2521  * @sclass: file security class
2522  * @sid: SID for path
2523  *
2524  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2525  * it afterward.
2526  */
2527 int security_genfs_sid(const char *fstype,
2528                        char *path,
2529                        u16 orig_sclass,
2530                        u32 *sid)
2531 {
2532         int retval;
2533
2534         read_lock(&policy_rwlock);
2535         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2536         read_unlock(&policy_rwlock);
2537         return retval;
2538 }
2539
2540 /**
2541  * security_fs_use - Determine how to handle labeling for a filesystem.
2542  * @sb: superblock in question
2543  */
2544 int security_fs_use(struct super_block *sb)
2545 {
2546         int rc = 0;
2547         struct ocontext *c;
2548         struct superblock_security_struct *sbsec = sb->s_security;
2549         const char *fstype = sb->s_type->name;
2550
2551         read_lock(&policy_rwlock);
2552
2553         c = policydb.ocontexts[OCON_FSUSE];
2554         while (c) {
2555                 if (strcmp(fstype, c->u.name) == 0)
2556                         break;
2557                 c = c->next;
2558         }
2559
2560         if (c) {
2561                 sbsec->behavior = c->v.behavior;
2562                 if (!c->sid[0]) {
2563                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2564                                                    &c->sid[0]);
2565                         if (rc)
2566                                 goto out;
2567                 }
2568                 sbsec->sid = c->sid[0];
2569         } else {
2570                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2571                                           &sbsec->sid);
2572                 if (rc) {
2573                         sbsec->behavior = SECURITY_FS_USE_NONE;
2574                         rc = 0;
2575                 } else {
2576                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2577                 }
2578         }
2579
2580 out:
2581         read_unlock(&policy_rwlock);
2582         return rc;
2583 }
2584
2585 int security_get_bools(int *len, char ***names, int **values)
2586 {
2587         int i, rc;
2588
2589         read_lock(&policy_rwlock);
2590         *names = NULL;
2591         *values = NULL;
2592
2593         rc = 0;
2594         *len = policydb.p_bools.nprim;
2595         if (!*len)
2596                 goto out;
2597
2598         rc = -ENOMEM;
2599         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2600         if (!*names)
2601                 goto err;
2602
2603         rc = -ENOMEM;
2604         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2605         if (!*values)
2606                 goto err;
2607
2608         for (i = 0; i < *len; i++) {
2609                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2610
2611                 rc = -ENOMEM;
2612                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2613                 if (!(*names)[i])
2614                         goto err;
2615         }
2616         rc = 0;
2617 out:
2618         read_unlock(&policy_rwlock);
2619         return rc;
2620 err:
2621         if (*names) {
2622                 for (i = 0; i < *len; i++)
2623                         kfree((*names)[i]);
2624         }
2625         kfree(*values);
2626         goto out;
2627 }
2628
2629
2630 int security_set_bools(int len, int *values)
2631 {
2632         int i, rc;
2633         int lenp, seqno = 0;
2634         struct cond_node *cur;
2635
2636         write_lock_irq(&policy_rwlock);
2637
2638         rc = -EFAULT;
2639         lenp = policydb.p_bools.nprim;
2640         if (len != lenp)
2641                 goto out;
2642
2643         for (i = 0; i < len; i++) {
2644                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2645                         audit_log(current->audit_context, GFP_ATOMIC,
2646                                 AUDIT_MAC_CONFIG_CHANGE,
2647                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2648                                 sym_name(&policydb, SYM_BOOLS, i),
2649                                 !!values[i],
2650                                 policydb.bool_val_to_struct[i]->state,
2651                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2652                                 audit_get_sessionid(current));
2653                 }
2654                 if (values[i])
2655                         policydb.bool_val_to_struct[i]->state = 1;
2656                 else
2657                         policydb.bool_val_to_struct[i]->state = 0;
2658         }
2659
2660         for (cur = policydb.cond_list; cur; cur = cur->next) {
2661                 rc = evaluate_cond_node(&policydb, cur);
2662                 if (rc)
2663                         goto out;
2664         }
2665
2666         seqno = ++latest_granting;
2667         rc = 0;
2668 out:
2669         write_unlock_irq(&policy_rwlock);
2670         if (!rc) {
2671                 avc_ss_reset(seqno);
2672                 selnl_notify_policyload(seqno);
2673                 selinux_status_update_policyload(seqno);
2674                 selinux_xfrm_notify_policyload();
2675         }
2676         return rc;
2677 }
2678
2679 int security_get_bool_value(int bool)
2680 {
2681         int rc;
2682         int len;
2683
2684         read_lock(&policy_rwlock);
2685
2686         rc = -EFAULT;
2687         len = policydb.p_bools.nprim;
2688         if (bool >= len)
2689                 goto out;
2690
2691         rc = policydb.bool_val_to_struct[bool]->state;
2692 out:
2693         read_unlock(&policy_rwlock);
2694         return rc;
2695 }
2696
2697 static int security_preserve_bools(struct policydb *p)
2698 {
2699         int rc, nbools = 0, *bvalues = NULL, i;
2700         char **bnames = NULL;
2701         struct cond_bool_datum *booldatum;
2702         struct cond_node *cur;
2703
2704         rc = security_get_bools(&nbools, &bnames, &bvalues);
2705         if (rc)
2706                 goto out;
2707         for (i = 0; i < nbools; i++) {
2708                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2709                 if (booldatum)
2710                         booldatum->state = bvalues[i];
2711         }
2712         for (cur = p->cond_list; cur; cur = cur->next) {
2713                 rc = evaluate_cond_node(p, cur);
2714                 if (rc)
2715                         goto out;
2716         }
2717
2718 out:
2719         if (bnames) {
2720                 for (i = 0; i < nbools; i++)
2721                         kfree(bnames[i]);
2722         }
2723         kfree(bnames);
2724         kfree(bvalues);
2725         return rc;
2726 }
2727
2728 /*
2729  * security_sid_mls_copy() - computes a new sid based on the given
2730  * sid and the mls portion of mls_sid.
2731  */
2732 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2733 {
2734         struct context *context1;
2735         struct context *context2;
2736         struct context newcon;
2737         char *s;
2738         u32 len;
2739         int rc;
2740
2741         rc = 0;
2742         if (!ss_initialized || !policydb.mls_enabled) {
2743                 *new_sid = sid;
2744                 goto out;
2745         }
2746
2747         context_init(&newcon);
2748
2749         read_lock(&policy_rwlock);
2750
2751         rc = -EINVAL;
2752         context1 = sidtab_search(&sidtab, sid);
2753         if (!context1) {
2754                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2755                         __func__, sid);
2756                 goto out_unlock;
2757         }
2758
2759         rc = -EINVAL;
2760         context2 = sidtab_search(&sidtab, mls_sid);
2761         if (!context2) {
2762                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2763                         __func__, mls_sid);
2764                 goto out_unlock;
2765         }
2766
2767         newcon.user = context1->user;
2768         newcon.role = context1->role;
2769         newcon.type = context1->type;
2770         rc = mls_context_cpy(&newcon, context2);
2771         if (rc)
2772                 goto out_unlock;
2773
2774         /* Check the validity of the new context. */
2775         if (!policydb_context_isvalid(&policydb, &newcon)) {
2776                 rc = convert_context_handle_invalid_context(&newcon);
2777                 if (rc) {
2778                         if (!context_struct_to_string(&newcon, &s, &len)) {
2779                                 audit_log(current->audit_context,
2780                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2781                                           "op=security_sid_mls_copy "
2782                                           "invalid_context=%s", s);
2783                                 kfree(s);
2784                         }
2785                         goto out_unlock;
2786                 }
2787         }
2788
2789         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2790 out_unlock:
2791         read_unlock(&policy_rwlock);
2792         context_destroy(&newcon);
2793 out:
2794         return rc;
2795 }
2796
2797 /**
2798  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2799  * @nlbl_sid: NetLabel SID
2800  * @nlbl_type: NetLabel labeling protocol type
2801  * @xfrm_sid: XFRM SID
2802  *
2803  * Description:
2804  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2805  * resolved into a single SID it is returned via @peer_sid and the function
2806  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2807  * returns a negative value.  A table summarizing the behavior is below:
2808  *
2809  *                                 | function return |      @sid
2810  *   ------------------------------+-----------------+-----------------
2811  *   no peer labels                |        0        |    SECSID_NULL
2812  *   single peer label             |        0        |    <peer_label>
2813  *   multiple, consistent labels   |        0        |    <peer_label>
2814  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2815  *
2816  */
2817 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2818                                  u32 xfrm_sid,
2819                                  u32 *peer_sid)
2820 {
2821         int rc;
2822         struct context *nlbl_ctx;
2823         struct context *xfrm_ctx;
2824
2825         *peer_sid = SECSID_NULL;
2826
2827         /* handle the common (which also happens to be the set of easy) cases
2828          * right away, these two if statements catch everything involving a
2829          * single or absent peer SID/label */
2830         if (xfrm_sid == SECSID_NULL) {
2831                 *peer_sid = nlbl_sid;
2832                 return 0;
2833         }
2834         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2835          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2836          * is present */
2837         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2838                 *peer_sid = xfrm_sid;
2839                 return 0;
2840         }
2841
2842         /* we don't need to check ss_initialized here since the only way both
2843          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2844          * security server was initialized and ss_initialized was true */
2845         if (!policydb.mls_enabled)
2846                 return 0;
2847
2848         read_lock(&policy_rwlock);
2849
2850         rc = -EINVAL;
2851         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2852         if (!nlbl_ctx) {
2853                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2854                        __func__, nlbl_sid);
2855                 goto out;
2856         }
2857         rc = -EINVAL;
2858         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2859         if (!xfrm_ctx) {
2860                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2861                        __func__, xfrm_sid);
2862                 goto out;
2863         }
2864         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2865         if (rc)
2866                 goto out;
2867
2868         /* at present NetLabel SIDs/labels really only carry MLS
2869          * information so if the MLS portion of the NetLabel SID
2870          * matches the MLS portion of the labeled XFRM SID/label
2871          * then pass along the XFRM SID as it is the most
2872          * expressive */
2873         *peer_sid = xfrm_sid;
2874 out:
2875         read_unlock(&policy_rwlock);
2876         return rc;
2877 }
2878
2879 static int get_classes_callback(void *k, void *d, void *args)
2880 {
2881         struct class_datum *datum = d;
2882         char *name = k, **classes = args;
2883         int value = datum->value - 1;
2884
2885         classes[value] = kstrdup(name, GFP_ATOMIC);
2886         if (!classes[value])
2887                 return -ENOMEM;
2888
2889         return 0;
2890 }
2891
2892 int security_get_classes(char ***classes, int *nclasses)
2893 {
2894         int rc;
2895
2896         read_lock(&policy_rwlock);
2897
2898         rc = -ENOMEM;
2899         *nclasses = policydb.p_classes.nprim;
2900         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2901         if (!*classes)
2902                 goto out;
2903
2904         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2905                         *classes);
2906         if (rc) {
2907                 int i;
2908                 for (i = 0; i < *nclasses; i++)
2909                         kfree((*classes)[i]);
2910                 kfree(*classes);
2911         }
2912
2913 out:
2914         read_unlock(&policy_rwlock);
2915         return rc;
2916 }
2917
2918 static int get_permissions_callback(void *k, void *d, void *args)
2919 {
2920         struct perm_datum *datum = d;
2921         char *name = k, **perms = args;
2922         int value = datum->value - 1;
2923
2924         perms[value] = kstrdup(name, GFP_ATOMIC);
2925         if (!perms[value])
2926                 return -ENOMEM;
2927
2928         return 0;
2929 }
2930
2931 int security_get_permissions(char *class, char ***perms, int *nperms)
2932 {
2933         int rc, i;
2934         struct class_datum *match;
2935
2936         read_lock(&policy_rwlock);
2937
2938         rc = -EINVAL;
2939         match = hashtab_search(policydb.p_classes.table, class);
2940         if (!match) {
2941                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2942                         __func__, class);
2943                 goto out;
2944         }
2945
2946         rc = -ENOMEM;
2947         *nperms = match->permissions.nprim;
2948         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2949         if (!*perms)
2950                 goto out;
2951
2952         if (match->comdatum) {
2953                 rc = hashtab_map(match->comdatum->permissions.table,
2954                                 get_permissions_callback, *perms);
2955                 if (rc)
2956                         goto err;
2957         }
2958
2959         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2960                         *perms);
2961         if (rc)
2962                 goto err;
2963
2964 out:
2965         read_unlock(&policy_rwlock);
2966         return rc;
2967
2968 err:
2969         read_unlock(&policy_rwlock);
2970         for (i = 0; i < *nperms; i++)
2971                 kfree((*perms)[i]);
2972         kfree(*perms);
2973         return rc;
2974 }
2975
2976 int security_get_reject_unknown(void)
2977 {
2978         return policydb.reject_unknown;
2979 }
2980
2981 int security_get_allow_unknown(void)
2982 {
2983         return policydb.allow_unknown;
2984 }
2985
2986 /**
2987  * security_policycap_supported - Check for a specific policy capability
2988  * @req_cap: capability
2989  *
2990  * Description:
2991  * This function queries the currently loaded policy to see if it supports the
2992  * capability specified by @req_cap.  Returns true (1) if the capability is
2993  * supported, false (0) if it isn't supported.
2994  *
2995  */
2996 int security_policycap_supported(unsigned int req_cap)
2997 {
2998         int rc;
2999
3000         read_lock(&policy_rwlock);
3001         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3002         read_unlock(&policy_rwlock);
3003
3004         return rc;
3005 }
3006
3007 struct selinux_audit_rule {
3008         u32 au_seqno;
3009         struct context au_ctxt;
3010 };
3011
3012 void selinux_audit_rule_free(void *vrule)
3013 {
3014         struct selinux_audit_rule *rule = vrule;
3015
3016         if (rule) {
3017                 context_destroy(&rule->au_ctxt);
3018                 kfree(rule);
3019         }
3020 }
3021
3022 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3023 {
3024         struct selinux_audit_rule *tmprule;
3025         struct role_datum *roledatum;
3026         struct type_datum *typedatum;
3027         struct user_datum *userdatum;
3028         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3029         int rc = 0;
3030
3031         *rule = NULL;
3032
3033         if (!ss_initialized)
3034                 return -EOPNOTSUPP;
3035
3036         switch (field) {
3037         case AUDIT_SUBJ_USER:
3038         case AUDIT_SUBJ_ROLE:
3039         case AUDIT_SUBJ_TYPE:
3040         case AUDIT_OBJ_USER:
3041         case AUDIT_OBJ_ROLE:
3042         case AUDIT_OBJ_TYPE:
3043                 /* only 'equals' and 'not equals' fit user, role, and type */
3044                 if (op != Audit_equal && op != Audit_not_equal)
3045                         return -EINVAL;
3046                 break;
3047         case AUDIT_SUBJ_SEN:
3048         case AUDIT_SUBJ_CLR:
3049         case AUDIT_OBJ_LEV_LOW:
3050         case AUDIT_OBJ_LEV_HIGH:
3051                 /* we do not allow a range, indicated by the presence of '-' */
3052                 if (strchr(rulestr, '-'))
3053                         return -EINVAL;
3054                 break;
3055         default:
3056                 /* only the above fields are valid */
3057                 return -EINVAL;
3058         }
3059
3060         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3061         if (!tmprule)
3062                 return -ENOMEM;
3063
3064         context_init(&tmprule->au_ctxt);
3065
3066         read_lock(&policy_rwlock);
3067
3068         tmprule->au_seqno = latest_granting;
3069
3070         switch (field) {
3071         case AUDIT_SUBJ_USER:
3072         case AUDIT_OBJ_USER:
3073                 rc = -EINVAL;
3074                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3075                 if (!userdatum)
3076                         goto out;
3077                 tmprule->au_ctxt.user = userdatum->value;
3078                 break;
3079         case AUDIT_SUBJ_ROLE:
3080         case AUDIT_OBJ_ROLE:
3081                 rc = -EINVAL;
3082                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3083                 if (!roledatum)
3084                         goto out;
3085                 tmprule->au_ctxt.role = roledatum->value;
3086                 break;
3087         case AUDIT_SUBJ_TYPE:
3088         case AUDIT_OBJ_TYPE:
3089                 rc = -EINVAL;
3090                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3091                 if (!typedatum)
3092                         goto out;
3093                 tmprule->au_ctxt.type = typedatum->value;
3094                 break;
3095         case AUDIT_SUBJ_SEN:
3096         case AUDIT_SUBJ_CLR:
3097         case AUDIT_OBJ_LEV_LOW:
3098         case AUDIT_OBJ_LEV_HIGH:
3099                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3100                 if (rc)
3101                         goto out;
3102                 break;
3103         }
3104         rc = 0;
3105 out:
3106         read_unlock(&policy_rwlock);
3107
3108         if (rc) {
3109                 selinux_audit_rule_free(tmprule);
3110                 tmprule = NULL;
3111         }
3112
3113         *rule = tmprule;
3114
3115         return rc;
3116 }
3117
3118 /* Check to see if the rule contains any selinux fields */
3119 int selinux_audit_rule_known(struct audit_krule *rule)
3120 {
3121         int i;
3122
3123         for (i = 0; i < rule->field_count; i++) {
3124                 struct audit_field *f = &rule->fields[i];
3125                 switch (f->type) {
3126                 case AUDIT_SUBJ_USER:
3127                 case AUDIT_SUBJ_ROLE:
3128                 case AUDIT_SUBJ_TYPE:
3129                 case AUDIT_SUBJ_SEN:
3130                 case AUDIT_SUBJ_CLR:
3131                 case AUDIT_OBJ_USER:
3132                 case AUDIT_OBJ_ROLE:
3133                 case AUDIT_OBJ_TYPE:
3134                 case AUDIT_OBJ_LEV_LOW:
3135                 case AUDIT_OBJ_LEV_HIGH:
3136                         return 1;
3137                 }
3138         }
3139
3140         return 0;
3141 }
3142
3143 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3144                              struct audit_context *actx)
3145 {
3146         struct context *ctxt;
3147         struct mls_level *level;
3148         struct selinux_audit_rule *rule = vrule;
3149         int match = 0;
3150
3151         if (unlikely(!rule)) {
3152                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3153                 return -ENOENT;
3154         }
3155
3156         read_lock(&policy_rwlock);
3157
3158         if (rule->au_seqno < latest_granting) {
3159                 match = -ESTALE;
3160                 goto out;
3161         }
3162
3163         ctxt = sidtab_search(&sidtab, sid);
3164         if (unlikely(!ctxt)) {
3165                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3166                           sid);
3167                 match = -ENOENT;
3168                 goto out;
3169         }
3170
3171         /* a field/op pair that is not caught here will simply fall through
3172            without a match */
3173         switch (field) {
3174         case AUDIT_SUBJ_USER:
3175         case AUDIT_OBJ_USER:
3176                 switch (op) {
3177                 case Audit_equal:
3178                         match = (ctxt->user == rule->au_ctxt.user);
3179                         break;
3180                 case Audit_not_equal:
3181                         match = (ctxt->user != rule->au_ctxt.user);
3182                         break;
3183                 }
3184                 break;
3185         case AUDIT_SUBJ_ROLE:
3186         case AUDIT_OBJ_ROLE:
3187                 switch (op) {
3188                 case Audit_equal:
3189                         match = (ctxt->role == rule->au_ctxt.role);
3190                         break;
3191                 case Audit_not_equal:
3192                         match = (ctxt->role != rule->au_ctxt.role);
3193                         break;
3194                 }
3195                 break;
3196         case AUDIT_SUBJ_TYPE:
3197         case AUDIT_OBJ_TYPE:
3198                 switch (op) {
3199                 case Audit_equal:
3200                         match = (ctxt->type == rule->au_ctxt.type);
3201                         break;
3202                 case Audit_not_equal:
3203                         match = (ctxt->type != rule->au_ctxt.type);
3204                         break;
3205                 }
3206                 break;
3207         case AUDIT_SUBJ_SEN:
3208         case AUDIT_SUBJ_CLR:
3209         case AUDIT_OBJ_LEV_LOW:
3210         case AUDIT_OBJ_LEV_HIGH:
3211                 level = ((field == AUDIT_SUBJ_SEN ||
3212                           field == AUDIT_OBJ_LEV_LOW) ?
3213                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3214                 switch (op) {
3215                 case Audit_equal:
3216                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3217                                              level);
3218                         break;
3219                 case Audit_not_equal:
3220                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3221                                               level);
3222                         break;
3223                 case Audit_lt:
3224                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3225                                                level) &&
3226                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3227                                                level));
3228                         break;
3229                 case Audit_le:
3230                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3231                                               level);
3232                         break;
3233                 case Audit_gt:
3234                         match = (mls_level_dom(level,
3235                                               &rule->au_ctxt.range.level[0]) &&
3236                                  !mls_level_eq(level,
3237                                                &rule->au_ctxt.range.level[0]));
3238                         break;
3239                 case Audit_ge:
3240                         match = mls_level_dom(level,
3241                                               &rule->au_ctxt.range.level[0]);
3242                         break;
3243                 }
3244         }
3245
3246 out:
3247         read_unlock(&policy_rwlock);
3248         return match;
3249 }
3250
3251 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3252
3253 static int aurule_avc_callback(u32 event)
3254 {
3255         int err = 0;
3256
3257         if (event == AVC_CALLBACK_RESET && aurule_callback)
3258                 err = aurule_callback();
3259         return err;
3260 }
3261
3262 static int __init aurule_init(void)
3263 {
3264         int err;
3265
3266         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3267         if (err)
3268                 panic("avc_add_callback() failed, error %d\n", err);
3269
3270         return err;
3271 }
3272 __initcall(aurule_init);
3273
3274 #ifdef CONFIG_NETLABEL
3275 /**
3276  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3277  * @secattr: the NetLabel packet security attributes
3278  * @sid: the SELinux SID
3279  *
3280  * Description:
3281  * Attempt to cache the context in @ctx, which was derived from the packet in
3282  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3283  * already been initialized.
3284  *
3285  */
3286 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3287                                       u32 sid)
3288 {
3289         u32 *sid_cache;
3290
3291         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3292         if (sid_cache == NULL)
3293                 return;
3294         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3295         if (secattr->cache == NULL) {
3296                 kfree(sid_cache);
3297                 return;
3298         }
3299
3300         *sid_cache = sid;
3301         secattr->cache->free = kfree;
3302         secattr->cache->data = sid_cache;
3303         secattr->flags |= NETLBL_SECATTR_CACHE;
3304 }
3305
3306 /**
3307  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3308  * @secattr: the NetLabel packet security attributes
3309  * @sid: the SELinux SID
3310  *
3311  * Description:
3312  * Convert the given NetLabel security attributes in @secattr into a
3313  * SELinux SID.  If the @secattr field does not contain a full SELinux
3314  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3315  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3316  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3317  * conversion for future lookups.  Returns zero on success, negative values on
3318  * failure.
3319  *
3320  */
3321 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3322                                    u32 *sid)
3323 {
3324         int rc;
3325         struct context *ctx;
3326         struct context ctx_new;
3327
3328         if (!ss_initialized) {
3329                 *sid = SECSID_NULL;
3330                 return 0;
3331         }
3332
3333         read_lock(&policy_rwlock);
3334
3335         if (secattr->flags & NETLBL_SECATTR_CACHE)
3336                 *sid = *(u32 *)secattr->cache->data;
3337         else if (secattr->flags & NETLBL_SECATTR_SECID)
3338                 *sid = secattr->attr.secid;
3339         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3340                 rc = -EIDRM;
3341                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3342                 if (ctx == NULL)
3343                         goto out;
3344
3345                 context_init(&ctx_new);
3346                 ctx_new.user = ctx->user;
3347                 ctx_new.role = ctx->role;
3348                 ctx_new.type = ctx->type;
3349                 mls_import_netlbl_lvl(&ctx_new, secattr);
3350                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3351                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3352                         if (rc)
3353                                 goto out;
3354                 }
3355                 rc = -EIDRM;
3356                 if (!mls_context_isvalid(&policydb, &ctx_new))
3357                         goto out_free;
3358
3359                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3360                 if (rc)
3361                         goto out_free;
3362
3363                 security_netlbl_cache_add(secattr, *sid);
3364
3365                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3366         } else
3367                 *sid = SECSID_NULL;
3368
3369         read_unlock(&policy_rwlock);
3370         return 0;
3371 out_free:
3372         ebitmap_destroy(&ctx_new.range.level[0].cat);
3373 out:
3374         read_unlock(&policy_rwlock);
3375         return rc;
3376 }
3377
3378 /**
3379  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3380  * @sid: the SELinux SID
3381  * @secattr: the NetLabel packet security attributes
3382  *
3383  * Description:
3384  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3385  * Returns zero on success, negative values on failure.
3386  *
3387  */
3388 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3389 {
3390         int rc;
3391         struct context *ctx;
3392
3393         if (!ss_initialized)
3394                 return 0;
3395
3396         read_lock(&policy_rwlock);
3397
3398         rc = -ENOENT;
3399         ctx = sidtab_search(&sidtab, sid);
3400         if (ctx == NULL)
3401                 goto out;
3402
3403         rc = -ENOMEM;
3404         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3405                                   GFP_ATOMIC);
3406         if (secattr->domain == NULL)
3407                 goto out;
3408
3409         secattr->attr.secid = sid;
3410         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3411         mls_export_netlbl_lvl(ctx, secattr);
3412         rc = mls_export_netlbl_cat(ctx, secattr);
3413 out:
3414         read_unlock(&policy_rwlock);
3415         return rc;
3416 }
3417 #endif /* CONFIG_NETLABEL */
3418
3419 /**
3420  * security_read_policy - read the policy.
3421  * @data: binary policy data
3422  * @len: length of data in bytes
3423  *
3424  */
3425 int security_read_policy(void **data, size_t *len)
3426 {
3427         int rc;
3428         struct policy_file fp;
3429
3430         if (!ss_initialized)
3431                 return -EINVAL;
3432
3433         *len = security_policydb_len();
3434
3435         *data = vmalloc_user(*len);
3436         if (!*data)
3437                 return -ENOMEM;
3438
3439         fp.data = *data;
3440         fp.len = *len;
3441
3442         read_lock(&policy_rwlock);
3443         rc = policydb_write(&policydb, &fp);
3444         read_unlock(&policy_rwlock);
3445
3446         if (rc)
3447                 return rc;
3448
3449         *len = (unsigned long)fp.data - (unsigned long)*data;
3450         return 0;
3451
3452 }