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[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         if (!ss_initialized)
 864                 return 0;
 865
 866         read_lock(&policy_rwlock);
 867
 868         rc = -EINVAL;
 869         old_context = sidtab_search(&sidtab, old_sid);
 870         if (!old_context) {
 871                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 872                        __func__, old_sid);
 873                 goto out;
 874         }
 875
 876         rc = -EINVAL;
 877         new_context = sidtab_search(&sidtab, new_sid);
 878         if (!new_context) {
 879                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 880                        __func__, new_sid);
 881                 goto out;
 882         }
 883
 884         rc = 0;
 885         /* type/domain unchanged */
 886         if (old_context->type == new_context->type)
 887                 goto out;
 888
 889         index = new_context->type;
 890         while (true) {
 891                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 892                                           index - 1);
 893                 BUG_ON(!type);
 894
 895                 /* not bounded anymore */
 896                 rc = -EPERM;
 897                 if (!type->bounds)
 898                         break;
 899
 900                 /* @newsid is bounded by @oldsid */
 901                 rc = 0;
 902                 if (type->bounds == old_context->type)
 903                         break;
 904
 905                 index = type->bounds;
 906         }
 907
 908         if (rc) {
 909                 char *old_name = NULL;
 910                 char *new_name = NULL;
 911                 u32 length;
 912
 913                 if (!context_struct_to_string(old_context,
 914                                               &old_name, &length) &&
 915                     !context_struct_to_string(new_context,
 916                                               &new_name, &length)) {
 917                         audit_log(current->audit_context,
 918                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 919                                   "op=security_bounded_transition "
 920                                   "seresult=denied "
 921                                   "oldcontext=%s newcontext=%s",
 922                                   old_name, new_name);
 923                 }
 924                 kfree(new_name);
 925                 kfree(old_name);
 926         }
 927 out:
 928         read_unlock(&policy_rwlock);
 929
 930         return rc;
 931 }
 932
 933 static void avd_init(struct av_decision *avd)
 934 {
 935         avd->allowed = 0;
 936         avd->auditallow = 0;
 937         avd->auditdeny = 0xffffffff;
 938         avd->seqno = latest_granting;
 939         avd->flags = 0;
 940 }
 941
 942 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 943                                         struct avtab_node *node)
 944 {
 945         unsigned int i;
 946
 947         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 948                 if (xpermd->driver != node->datum.u.xperms->driver)
 949                         return;
 950         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 951                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 952                                         xpermd->driver))
 953                         return;
 954         } else {
 955                 BUG();
 956         }
 957
 958         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 959                 xpermd->used |= XPERMS_ALLOWED;
 960                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 961                         memset(xpermd->allowed->p, 0xff,
 962                                         sizeof(xpermd->allowed->p));
 963                 }
 964                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 965                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 966                                 xpermd->allowed->p[i] |=
 967                                         node->datum.u.xperms->perms.p[i];
 968                 }
 969         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 970                 xpermd->used |= XPERMS_AUDITALLOW;
 971                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 972                         memset(xpermd->auditallow->p, 0xff,
 973                                         sizeof(xpermd->auditallow->p));
 974                 }
 975                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 976                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 977                                 xpermd->auditallow->p[i] |=
 978                                         node->datum.u.xperms->perms.p[i];
 979                 }
 980         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 981                 xpermd->used |= XPERMS_DONTAUDIT;
 982                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 983                         memset(xpermd->dontaudit->p, 0xff,
 984                                         sizeof(xpermd->dontaudit->p));
 985                 }
 986                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 987                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 988                                 xpermd->dontaudit->p[i] |=
 989                                         node->datum.u.xperms->perms.p[i];
 990                 }
 991         } else {
 992                 BUG();
 993         }
 994 }
 995
 996 void security_compute_xperms_decision(u32 ssid,
 997                                 u32 tsid,
 998                                 u16 orig_tclass,
 999                                 u8 driver,
1000                                 struct extended_perms_decision *xpermd)
1001 {
1002         u16 tclass;
1003         struct context *scontext, *tcontext;
1004         struct avtab_key avkey;
1005         struct avtab_node *node;
1006         struct ebitmap *sattr, *tattr;
1007         struct ebitmap_node *snode, *tnode;
1008         unsigned int i, j;
1009
1010         xpermd->driver = driver;
1011         xpermd->used = 0;
1012         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1013         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1014         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1015
1016         read_lock(&policy_rwlock);
1017         if (!ss_initialized)
1018                 goto allow;
1019
1020         scontext = sidtab_search(&sidtab, ssid);
1021         if (!scontext) {
1022                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1023                        __func__, ssid);
1024                 goto out;
1025         }
1026
1027         tcontext = sidtab_search(&sidtab, tsid);
1028         if (!tcontext) {
1029                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1030                        __func__, tsid);
1031                 goto out;
1032         }
1033
1034         tclass = unmap_class(orig_tclass);
1035         if (unlikely(orig_tclass && !tclass)) {
1036                 if (policydb.allow_unknown)
1037                         goto allow;
1038                 goto out;
1039         }
1040
1041
1042         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1043                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1044                 goto out;
1045         }
1046
1047         avkey.target_class = tclass;
1048         avkey.specified = AVTAB_XPERMS;
1049         sattr = flex_array_get(policydb.type_attr_map_array,
1050                                 scontext->type - 1);
1051         BUG_ON(!sattr);
1052         tattr = flex_array_get(policydb.type_attr_map_array,
1053                                 tcontext->type - 1);
1054         BUG_ON(!tattr);
1055         ebitmap_for_each_positive_bit(sattr, snode, i) {
1056                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1057                         avkey.source_type = i + 1;
1058                         avkey.target_type = j + 1;
1059                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1060                              node;
1061                              node = avtab_search_node_next(node, avkey.specified))
1062                                 services_compute_xperms_decision(xpermd, node);
1063
1064                         cond_compute_xperms(&policydb.te_cond_avtab,
1065                                                 &avkey, xpermd);
1066                 }
1067         }
1068 out:
1069         read_unlock(&policy_rwlock);
1070         return;
1071 allow:
1072         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1073         goto out;
1074 }
1075
1076 /**
1077  * security_compute_av - Compute access vector decisions.
1078  * @ssid: source security identifier
1079  * @tsid: target security identifier
1080  * @tclass: target security class
1081  * @avd: access vector decisions
1082  * @xperms: extended permissions
1083  *
1084  * Compute a set of access vector decisions based on the
1085  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1086  */
1087 void security_compute_av(u32 ssid,
1088                          u32 tsid,
1089                          u16 orig_tclass,
1090                          struct av_decision *avd,
1091                          struct extended_perms *xperms)
1092 {
1093         u16 tclass;
1094         struct context *scontext = NULL, *tcontext = NULL;
1095
1096         read_lock(&policy_rwlock);
1097         avd_init(avd);
1098         xperms->len = 0;
1099         if (!ss_initialized)
1100                 goto allow;
1101
1102         scontext = sidtab_search(&sidtab, ssid);
1103         if (!scontext) {
1104                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1105                        __func__, ssid);
1106                 goto out;
1107         }
1108
1109         /* permissive domain? */
1110         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1111                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1112
1113         tcontext = sidtab_search(&sidtab, tsid);
1114         if (!tcontext) {
1115                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1116                        __func__, tsid);
1117                 goto out;
1118         }
1119
1120         tclass = unmap_class(orig_tclass);
1121         if (unlikely(orig_tclass && !tclass)) {
1122                 if (policydb.allow_unknown)
1123                         goto allow;
1124                 goto out;
1125         }
1126         context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1127         map_decision(orig_tclass, avd, policydb.allow_unknown);
1128 out:
1129         read_unlock(&policy_rwlock);
1130         return;
1131 allow:
1132         avd->allowed = 0xffffffff;
1133         goto out;
1134 }
1135
1136 void security_compute_av_user(u32 ssid,
1137                               u32 tsid,
1138                               u16 tclass,
1139                               struct av_decision *avd)
1140 {
1141         struct context *scontext = NULL, *tcontext = NULL;
1142
1143         read_lock(&policy_rwlock);
1144         avd_init(avd);
1145         if (!ss_initialized)
1146                 goto allow;
1147
1148         scontext = sidtab_search(&sidtab, ssid);
1149         if (!scontext) {
1150                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1151                        __func__, ssid);
1152                 goto out;
1153         }
1154
1155         /* permissive domain? */
1156         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1157                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1158
1159         tcontext = sidtab_search(&sidtab, tsid);
1160         if (!tcontext) {
1161                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1162                        __func__, tsid);
1163                 goto out;
1164         }
1165
1166         if (unlikely(!tclass)) {
1167                 if (policydb.allow_unknown)
1168                         goto allow;
1169                 goto out;
1170         }
1171
1172         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1173  out:
1174         read_unlock(&policy_rwlock);
1175         return;
1176 allow:
1177         avd->allowed = 0xffffffff;
1178         goto out;
1179 }
1180
1181 /*
1182  * Write the security context string representation of
1183  * the context structure `context' into a dynamically
1184  * allocated string of the correct size.  Set `*scontext'
1185  * to point to this string and set `*scontext_len' to
1186  * the length of the string.
1187  */
1188 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1189 {
1190         char *scontextp;
1191
1192         if (scontext)
1193                 *scontext = NULL;
1194         *scontext_len = 0;
1195
1196         if (context->len) {
1197                 *scontext_len = context->len;
1198                 if (scontext) {
1199                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1200                         if (!(*scontext))
1201                                 return -ENOMEM;
1202                 }
1203                 return 0;
1204         }
1205
1206         /* Compute the size of the context. */
1207         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1208         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1209         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1210         *scontext_len += mls_compute_context_len(context);
1211
1212         if (!scontext)
1213                 return 0;
1214
1215         /* Allocate space for the context; caller must free this space. */
1216         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1217         if (!scontextp)
1218                 return -ENOMEM;
1219         *scontext = scontextp;
1220
1221         /*
1222          * Copy the user name, role name and type name into the context.
1223          */
1224         scontextp += sprintf(scontextp, "%s:%s:%s",
1225                 sym_name(&policydb, SYM_USERS, context->user - 1),
1226                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1227                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1228
1229         mls_sid_to_context(context, &scontextp);
1230
1231         *scontextp = 0;
1232
1233         return 0;
1234 }
1235
1236 #include "initial_sid_to_string.h"
1237
1238 const char *security_get_initial_sid_context(u32 sid)
1239 {
1240         if (unlikely(sid > SECINITSID_NUM))
1241                 return NULL;
1242         return initial_sid_to_string[sid];
1243 }
1244
1245 static int security_sid_to_context_core(u32 sid, char **scontext,
1246                                         u32 *scontext_len, int force)
1247 {
1248         struct context *context;
1249         int rc = 0;
1250
1251         if (scontext)
1252                 *scontext = NULL;
1253         *scontext_len  = 0;
1254
1255         if (!ss_initialized) {
1256                 if (sid <= SECINITSID_NUM) {
1257                         char *scontextp;
1258
1259                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1260                         if (!scontext)
1261                                 goto out;
1262                         scontextp = kmemdup(initial_sid_to_string[sid],
1263                                             *scontext_len, GFP_ATOMIC);
1264                         if (!scontextp) {
1265                                 rc = -ENOMEM;
1266                                 goto out;
1267                         }
1268                         *scontext = scontextp;
1269                         goto out;
1270                 }
1271                 printk(KERN_ERR "SELinux: %s:  called before initial "
1272                        "load_policy on unknown SID %d\n", __func__, sid);
1273                 rc = -EINVAL;
1274                 goto out;
1275         }
1276         read_lock(&policy_rwlock);
1277         if (force)
1278                 context = sidtab_search_force(&sidtab, sid);
1279         else
1280                 context = sidtab_search(&sidtab, sid);
1281         if (!context) {
1282                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1283                         __func__, sid);
1284                 rc = -EINVAL;
1285                 goto out_unlock;
1286         }
1287         rc = context_struct_to_string(context, scontext, scontext_len);
1288 out_unlock:
1289         read_unlock(&policy_rwlock);
1290 out:
1291         return rc;
1292
1293 }
1294
1295 /**
1296  * security_sid_to_context - Obtain a context for a given SID.
1297  * @sid: security identifier, SID
1298  * @scontext: security context
1299  * @scontext_len: length in bytes
1300  *
1301  * Write the string representation of the context associated with @sid
1302  * into a dynamically allocated string of the correct size.  Set @scontext
1303  * to point to this string and set @scontext_len to the length of the string.
1304  */
1305 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1306 {
1307         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1308 }
1309
1310 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1311 {
1312         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1313 }
1314
1315 /*
1316  * Caveat:  Mutates scontext.
1317  */
1318 static int string_to_context_struct(struct policydb *pol,
1319                                     struct sidtab *sidtabp,
1320                                     char *scontext,
1321                                     u32 scontext_len,
1322                                     struct context *ctx,
1323                                     u32 def_sid)
1324 {
1325         struct role_datum *role;
1326         struct type_datum *typdatum;
1327         struct user_datum *usrdatum;
1328         char *scontextp, *p, oldc;
1329         int rc = 0;
1330
1331         context_init(ctx);
1332
1333         /* Parse the security context. */
1334
1335         rc = -EINVAL;
1336         scontextp = (char *) scontext;
1337
1338         /* Extract the user. */
1339         p = scontextp;
1340         while (*p && *p != ':')
1341                 p++;
1342
1343         if (*p == 0)
1344                 goto out;
1345
1346         *p++ = 0;
1347
1348         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1349         if (!usrdatum)
1350                 goto out;
1351
1352         ctx->user = usrdatum->value;
1353
1354         /* Extract role. */
1355         scontextp = p;
1356         while (*p && *p != ':')
1357                 p++;
1358
1359         if (*p == 0)
1360                 goto out;
1361
1362         *p++ = 0;
1363
1364         role = hashtab_search(pol->p_roles.table, scontextp);
1365         if (!role)
1366                 goto out;
1367         ctx->role = role->value;
1368
1369         /* Extract type. */
1370         scontextp = p;
1371         while (*p && *p != ':')
1372                 p++;
1373         oldc = *p;
1374         *p++ = 0;
1375
1376         typdatum = hashtab_search(pol->p_types.table, scontextp);
1377         if (!typdatum || typdatum->attribute)
1378                 goto out;
1379
1380         ctx->type = typdatum->value;
1381
1382         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1383         if (rc)
1384                 goto out;
1385
1386         rc = -EINVAL;
1387         if ((p - scontext) < scontext_len)
1388                 goto out;
1389
1390         /* Check the validity of the new context. */
1391         if (!policydb_context_isvalid(pol, ctx))
1392                 goto out;
1393         rc = 0;
1394 out:
1395         if (rc)
1396                 context_destroy(ctx);
1397         return rc;
1398 }
1399
1400 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1401                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1402                                         int force)
1403 {
1404         char *scontext2, *str = NULL;
1405         struct context context;
1406         int rc = 0;
1407
1408         /* An empty security context is never valid. */
1409         if (!scontext_len)
1410                 return -EINVAL;
1411
1412         /* Copy the string to allow changes and ensure a NUL terminator */
1413         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1414         if (!scontext2)
1415                 return -ENOMEM;
1416
1417         if (!ss_initialized) {
1418                 int i;
1419
1420                 for (i = 1; i < SECINITSID_NUM; i++) {
1421                         if (!strcmp(initial_sid_to_string[i], scontext2)) {
1422                                 *sid = i;
1423                                 goto out;
1424                         }
1425                 }
1426                 *sid = SECINITSID_KERNEL;
1427                 goto out;
1428         }
1429         *sid = SECSID_NULL;
1430
1431         if (force) {
1432                 /* Save another copy for storing in uninterpreted form */
1433                 rc = -ENOMEM;
1434                 str = kstrdup(scontext2, gfp_flags);
1435                 if (!str)
1436                         goto out;
1437         }
1438
1439         read_lock(&policy_rwlock);
1440         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1441                                       scontext_len, &context, def_sid);
1442         if (rc == -EINVAL && force) {
1443                 context.str = str;
1444                 context.len = strlen(str) + 1;
1445                 str = NULL;
1446         } else if (rc)
1447                 goto out_unlock;
1448         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1449         context_destroy(&context);
1450 out_unlock:
1451         read_unlock(&policy_rwlock);
1452 out:
1453         kfree(scontext2);
1454         kfree(str);
1455         return rc;
1456 }
1457
1458 /**
1459  * security_context_to_sid - Obtain a SID for a given security context.
1460  * @scontext: security context
1461  * @scontext_len: length in bytes
1462  * @sid: security identifier, SID
1463  * @gfp: context for the allocation
1464  *
1465  * Obtains a SID associated with the security context that
1466  * has the string representation specified by @scontext.
1467  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1468  * memory is available, or 0 on success.
1469  */
1470 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1471                             gfp_t gfp)
1472 {
1473         return security_context_to_sid_core(scontext, scontext_len,
1474                                             sid, SECSID_NULL, gfp, 0);
1475 }
1476
1477 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1478 {
1479         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1480 }
1481
1482 /**
1483  * security_context_to_sid_default - Obtain a SID for a given security context,
1484  * falling back to specified default if needed.
1485  *
1486  * @scontext: security context
1487  * @scontext_len: length in bytes
1488  * @sid: security identifier, SID
1489  * @def_sid: default SID to assign on error
1490  *
1491  * Obtains a SID associated with the security context that
1492  * has the string representation specified by @scontext.
1493  * The default SID is passed to the MLS layer to be used to allow
1494  * kernel labeling of the MLS field if the MLS field is not present
1495  * (for upgrading to MLS without full relabel).
1496  * Implicitly forces adding of the context even if it cannot be mapped yet.
1497  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1498  * memory is available, or 0 on success.
1499  */
1500 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1501                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1502 {
1503         return security_context_to_sid_core(scontext, scontext_len,
1504                                             sid, def_sid, gfp_flags, 1);
1505 }
1506
1507 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1508                                   u32 *sid)
1509 {
1510         return security_context_to_sid_core(scontext, scontext_len,
1511                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1512 }
1513
1514 static int compute_sid_handle_invalid_context(
1515         struct context *scontext,
1516         struct context *tcontext,
1517         u16 tclass,
1518         struct context *newcontext)
1519 {
1520         char *s = NULL, *t = NULL, *n = NULL;
1521         u32 slen, tlen, nlen;
1522
1523         if (context_struct_to_string(scontext, &s, &slen))
1524                 goto out;
1525         if (context_struct_to_string(tcontext, &t, &tlen))
1526                 goto out;
1527         if (context_struct_to_string(newcontext, &n, &nlen))
1528                 goto out;
1529         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1530                   "op=security_compute_sid invalid_context=%s"
1531                   " scontext=%s"
1532                   " tcontext=%s"
1533                   " tclass=%s",
1534                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1535 out:
1536         kfree(s);
1537         kfree(t);
1538         kfree(n);
1539         if (!selinux_enforcing)
1540                 return 0;
1541         return -EACCES;
1542 }
1543
1544 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1545                                   u32 stype, u32 ttype, u16 tclass,
1546                                   const char *objname)
1547 {
1548         struct filename_trans ft;
1549         struct filename_trans_datum *otype;
1550
1551         /*
1552          * Most filename trans rules are going to live in specific directories
1553          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1554          * if the ttype does not contain any rules.
1555          */
1556         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1557                 return;
1558
1559         ft.stype = stype;
1560         ft.ttype = ttype;
1561         ft.tclass = tclass;
1562         ft.name = objname;
1563
1564         otype = hashtab_search(p->filename_trans, &ft);
1565         if (otype)
1566                 newcontext->type = otype->otype;
1567 }
1568
1569 static int security_compute_sid(u32 ssid,
1570                                 u32 tsid,
1571                                 u16 orig_tclass,
1572                                 u32 specified,
1573                                 const char *objname,
1574                                 u32 *out_sid,
1575                                 bool kern)
1576 {
1577         struct class_datum *cladatum = NULL;
1578         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1579         struct role_trans *roletr = NULL;
1580         struct avtab_key avkey;
1581         struct avtab_datum *avdatum;
1582         struct avtab_node *node;
1583         u16 tclass;
1584         int rc = 0;
1585         bool sock;
1586
1587         if (!ss_initialized) {
1588                 switch (orig_tclass) {
1589                 case SECCLASS_PROCESS: /* kernel value */
1590                         *out_sid = ssid;
1591                         break;
1592                 default:
1593                         *out_sid = tsid;
1594                         break;
1595                 }
1596                 goto out;
1597         }
1598
1599         context_init(&newcontext);
1600
1601         read_lock(&policy_rwlock);
1602
1603         if (kern) {
1604                 tclass = unmap_class(orig_tclass);
1605                 sock = security_is_socket_class(orig_tclass);
1606         } else {
1607                 tclass = orig_tclass;
1608                 sock = security_is_socket_class(map_class(tclass));
1609         }
1610
1611         scontext = sidtab_search(&sidtab, ssid);
1612         if (!scontext) {
1613                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1614                        __func__, ssid);
1615                 rc = -EINVAL;
1616                 goto out_unlock;
1617         }
1618         tcontext = sidtab_search(&sidtab, tsid);
1619         if (!tcontext) {
1620                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1621                        __func__, tsid);
1622                 rc = -EINVAL;
1623                 goto out_unlock;
1624         }
1625
1626         if (tclass && tclass <= policydb.p_classes.nprim)
1627                 cladatum = policydb.class_val_to_struct[tclass - 1];
1628
1629         /* Set the user identity. */
1630         switch (specified) {
1631         case AVTAB_TRANSITION:
1632         case AVTAB_CHANGE:
1633                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1634                         newcontext.user = tcontext->user;
1635                 } else {
1636                         /* notice this gets both DEFAULT_SOURCE and unset */
1637                         /* Use the process user identity. */
1638                         newcontext.user = scontext->user;
1639                 }
1640                 break;
1641         case AVTAB_MEMBER:
1642                 /* Use the related object owner. */
1643                 newcontext.user = tcontext->user;
1644                 break;
1645         }
1646
1647         /* Set the role to default values. */
1648         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1649                 newcontext.role = scontext->role;
1650         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1651                 newcontext.role = tcontext->role;
1652         } else {
1653                 if ((tclass == policydb.process_class) || (sock == true))
1654                         newcontext.role = scontext->role;
1655                 else
1656                         newcontext.role = OBJECT_R_VAL;
1657         }
1658
1659         /* Set the type to default values. */
1660         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1661                 newcontext.type = scontext->type;
1662         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1663                 newcontext.type = tcontext->type;
1664         } else {
1665                 if ((tclass == policydb.process_class) || (sock == true)) {
1666                         /* Use the type of process. */
1667                         newcontext.type = scontext->type;
1668                 } else {
1669                         /* Use the type of the related object. */
1670                         newcontext.type = tcontext->type;
1671                 }
1672         }
1673
1674         /* Look for a type transition/member/change rule. */
1675         avkey.source_type = scontext->type;
1676         avkey.target_type = tcontext->type;
1677         avkey.target_class = tclass;
1678         avkey.specified = specified;
1679         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1680
1681         /* If no permanent rule, also check for enabled conditional rules */
1682         if (!avdatum) {
1683                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1684                 for (; node; node = avtab_search_node_next(node, specified)) {
1685                         if (node->key.specified & AVTAB_ENABLED) {
1686                                 avdatum = &node->datum;
1687                                 break;
1688                         }
1689                 }
1690         }
1691
1692         if (avdatum) {
1693                 /* Use the type from the type transition/member/change rule. */
1694                 newcontext.type = avdatum->u.data;
1695         }
1696
1697         /* if we have a objname this is a file trans check so check those rules */
1698         if (objname)
1699                 filename_compute_type(&policydb, &newcontext, scontext->type,
1700                                       tcontext->type, tclass, objname);
1701
1702         /* Check for class-specific changes. */
1703         if (specified & AVTAB_TRANSITION) {
1704                 /* Look for a role transition rule. */
1705                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1706                         if ((roletr->role == scontext->role) &&
1707                             (roletr->type == tcontext->type) &&
1708                             (roletr->tclass == tclass)) {
1709                                 /* Use the role transition rule. */
1710                                 newcontext.role = roletr->new_role;
1711                                 break;
1712                         }
1713                 }
1714         }
1715
1716         /* Set the MLS attributes.
1717            This is done last because it may allocate memory. */
1718         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1719                              &newcontext, sock);
1720         if (rc)
1721                 goto out_unlock;
1722
1723         /* Check the validity of the context. */
1724         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1725                 rc = compute_sid_handle_invalid_context(scontext,
1726                                                         tcontext,
1727                                                         tclass,
1728                                                         &newcontext);
1729                 if (rc)
1730                         goto out_unlock;
1731         }
1732         /* Obtain the sid for the context. */
1733         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1734 out_unlock:
1735         read_unlock(&policy_rwlock);
1736         context_destroy(&newcontext);
1737 out:
1738         return rc;
1739 }
1740
1741 /**
1742  * security_transition_sid - Compute the SID for a new subject/object.
1743  * @ssid: source security identifier
1744  * @tsid: target security identifier
1745  * @tclass: target security class
1746  * @out_sid: security identifier for new subject/object
1747  *
1748  * Compute a SID to use for labeling a new subject or object in the
1749  * class @tclass based on a SID pair (@ssid, @tsid).
1750  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1751  * if insufficient memory is available, or %0 if the new SID was
1752  * computed successfully.
1753  */
1754 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1755                             const struct qstr *qstr, u32 *out_sid)
1756 {
1757         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1758                                     qstr ? qstr->name : NULL, out_sid, true);
1759 }
1760
1761 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1762                                  const char *objname, u32 *out_sid)
1763 {
1764         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1765                                     objname, out_sid, false);
1766 }
1767
1768 /**
1769  * security_member_sid - Compute the SID for member selection.
1770  * @ssid: source security identifier
1771  * @tsid: target security identifier
1772  * @tclass: target security class
1773  * @out_sid: security identifier for selected member
1774  *
1775  * Compute a SID to use when selecting a member of a polyinstantiated
1776  * object of class @tclass based on a SID pair (@ssid, @tsid).
1777  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1778  * if insufficient memory is available, or %0 if the SID was
1779  * computed successfully.
1780  */
1781 int security_member_sid(u32 ssid,
1782                         u32 tsid,
1783                         u16 tclass,
1784                         u32 *out_sid)
1785 {
1786         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1787                                     out_sid, false);
1788 }
1789
1790 /**
1791  * security_change_sid - Compute the SID for object relabeling.
1792  * @ssid: source security identifier
1793  * @tsid: target security identifier
1794  * @tclass: target security class
1795  * @out_sid: security identifier for selected member
1796  *
1797  * Compute a SID to use for relabeling an object of class @tclass
1798  * based on a SID pair (@ssid, @tsid).
1799  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1800  * if insufficient memory is available, or %0 if the SID was
1801  * computed successfully.
1802  */
1803 int security_change_sid(u32 ssid,
1804                         u32 tsid,
1805                         u16 tclass,
1806                         u32 *out_sid)
1807 {
1808         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1809                                     out_sid, false);
1810 }
1811
1812 /* Clone the SID into the new SID table. */
1813 static int clone_sid(u32 sid,
1814                      struct context *context,
1815                      void *arg)
1816 {
1817         struct sidtab *s = arg;
1818
1819         if (sid > SECINITSID_NUM)
1820                 return sidtab_insert(s, sid, context);
1821         else
1822                 return 0;
1823 }
1824
1825 static inline int convert_context_handle_invalid_context(struct context *context)
1826 {
1827         char *s;
1828         u32 len;
1829
1830         if (selinux_enforcing)
1831                 return -EINVAL;
1832
1833         if (!context_struct_to_string(context, &s, &len)) {
1834                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1835                 kfree(s);
1836         }
1837         return 0;
1838 }
1839
1840 struct convert_context_args {
1841         struct policydb *oldp;
1842         struct policydb *newp;
1843 };
1844
1845 /*
1846  * Convert the values in the security context
1847  * structure `c' from the values specified
1848  * in the policy `p->oldp' to the values specified
1849  * in the policy `p->newp'.  Verify that the
1850  * context is valid under the new policy.
1851  */
1852 static int convert_context(u32 key,
1853                            struct context *c,
1854                            void *p)
1855 {
1856         struct convert_context_args *args;
1857         struct context oldc;
1858         struct ocontext *oc;
1859         struct mls_range *range;
1860         struct role_datum *role;
1861         struct type_datum *typdatum;
1862         struct user_datum *usrdatum;
1863         char *s;
1864         u32 len;
1865         int rc = 0;
1866
1867         if (key <= SECINITSID_NUM)
1868                 goto out;
1869
1870         args = p;
1871
1872         if (c->str) {
1873                 struct context ctx;
1874
1875                 rc = -ENOMEM;
1876                 s = kstrdup(c->str, GFP_KERNEL);
1877                 if (!s)
1878                         goto out;
1879
1880                 rc = string_to_context_struct(args->newp, NULL, s,
1881                                               c->len, &ctx, SECSID_NULL);
1882                 kfree(s);
1883                 if (!rc) {
1884                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1885                                c->str);
1886                         /* Replace string with mapped representation. */
1887                         kfree(c->str);
1888                         memcpy(c, &ctx, sizeof(*c));
1889                         goto out;
1890                 } else if (rc == -EINVAL) {
1891                         /* Retain string representation for later mapping. */
1892                         rc = 0;
1893                         goto out;
1894                 } else {
1895                         /* Other error condition, e.g. ENOMEM. */
1896                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1897                                c->str, -rc);
1898                         goto out;
1899                 }
1900         }
1901
1902         rc = context_cpy(&oldc, c);
1903         if (rc)
1904                 goto out;
1905
1906         /* Convert the user. */
1907         rc = -EINVAL;
1908         usrdatum = hashtab_search(args->newp->p_users.table,
1909                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1910         if (!usrdatum)
1911                 goto bad;
1912         c->user = usrdatum->value;
1913
1914         /* Convert the role. */
1915         rc = -EINVAL;
1916         role = hashtab_search(args->newp->p_roles.table,
1917                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1918         if (!role)
1919                 goto bad;
1920         c->role = role->value;
1921
1922         /* Convert the type. */
1923         rc = -EINVAL;
1924         typdatum = hashtab_search(args->newp->p_types.table,
1925                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1926         if (!typdatum)
1927                 goto bad;
1928         c->type = typdatum->value;
1929
1930         /* Convert the MLS fields if dealing with MLS policies */
1931         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1932                 rc = mls_convert_context(args->oldp, args->newp, c);
1933                 if (rc)
1934                         goto bad;
1935         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1936                 /*
1937                  * Switching between MLS and non-MLS policy:
1938                  * free any storage used by the MLS fields in the
1939                  * context for all existing entries in the sidtab.
1940                  */
1941                 mls_context_destroy(c);
1942         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1943                 /*
1944                  * Switching between non-MLS and MLS policy:
1945                  * ensure that the MLS fields of the context for all
1946                  * existing entries in the sidtab are filled in with a
1947                  * suitable default value, likely taken from one of the
1948                  * initial SIDs.
1949                  */
1950                 oc = args->newp->ocontexts[OCON_ISID];
1951                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1952                         oc = oc->next;
1953                 rc = -EINVAL;
1954                 if (!oc) {
1955                         printk(KERN_ERR "SELinux:  unable to look up"
1956                                 " the initial SIDs list\n");
1957                         goto bad;
1958                 }
1959                 range = &oc->context[0].range;
1960                 rc = mls_range_set(c, range);
1961                 if (rc)
1962                         goto bad;
1963         }
1964
1965         /* Check the validity of the new context. */
1966         if (!policydb_context_isvalid(args->newp, c)) {
1967                 rc = convert_context_handle_invalid_context(&oldc);
1968                 if (rc)
1969                         goto bad;
1970         }
1971
1972         context_destroy(&oldc);
1973
1974         rc = 0;
1975 out:
1976         return rc;
1977 bad:
1978         /* Map old representation to string and save it. */
1979         rc = context_struct_to_string(&oldc, &s, &len);
1980         if (rc)
1981                 return rc;
1982         context_destroy(&oldc);
1983         context_destroy(c);
1984         c->str = s;
1985         c->len = len;
1986         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1987                c->str);
1988         rc = 0;
1989         goto out;
1990 }
1991
1992 static void security_load_policycaps(void)
1993 {
1994         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1995                                                   POLICYDB_CAPABILITY_NETPEER);
1996         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1997                                                   POLICYDB_CAPABILITY_OPENPERM);
1998         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1999                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
2000 }
2001
2002 static int security_preserve_bools(struct policydb *p);
2003
2004 /**
2005  * security_load_policy - Load a security policy configuration.
2006  * @data: binary policy data
2007  * @len: length of data in bytes
2008  *
2009  * Load a new set of security policy configuration data,
2010  * validate it and convert the SID table as necessary.
2011  * This function will flush the access vector cache after
2012  * loading the new policy.
2013  */
2014 int security_load_policy(void *data, size_t len)
2015 {
2016         struct policydb *oldpolicydb, *newpolicydb;
2017         struct sidtab oldsidtab, newsidtab;
2018         struct selinux_mapping *oldmap, *map = NULL;
2019         struct convert_context_args args;
2020         u32 seqno;
2021         u16 map_size;
2022         int rc = 0;
2023         struct policy_file file = { data, len }, *fp = &file;
2024
2025         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2026         if (!oldpolicydb) {
2027                 rc = -ENOMEM;
2028                 goto out;
2029         }
2030         newpolicydb = oldpolicydb + 1;
2031
2032         if (!ss_initialized) {
2033                 avtab_cache_init();
2034                 rc = policydb_read(&policydb, fp);
2035                 if (rc) {
2036                         avtab_cache_destroy();
2037                         goto out;
2038                 }
2039
2040                 policydb.len = len;
2041                 rc = selinux_set_mapping(&policydb, secclass_map,
2042                                          &current_mapping,
2043                                          &current_mapping_size);
2044                 if (rc) {
2045                         policydb_destroy(&policydb);
2046                         avtab_cache_destroy();
2047                         goto out;
2048                 }
2049
2050                 rc = policydb_load_isids(&policydb, &sidtab);
2051                 if (rc) {
2052                         policydb_destroy(&policydb);
2053                         avtab_cache_destroy();
2054                         goto out;
2055                 }
2056
2057                 security_load_policycaps();
2058                 ss_initialized = 1;
2059                 seqno = ++latest_granting;
2060                 selinux_complete_init();
2061                 avc_ss_reset(seqno);
2062                 selnl_notify_policyload(seqno);
2063                 selinux_status_update_policyload(seqno);
2064                 selinux_netlbl_cache_invalidate();
2065                 selinux_xfrm_notify_policyload();
2066                 goto out;
2067         }
2068
2069 #if 0
2070         sidtab_hash_eval(&sidtab, "sids");
2071 #endif
2072
2073         rc = policydb_read(newpolicydb, fp);
2074         if (rc)
2075                 goto out;
2076
2077         newpolicydb->len = len;
2078         /* If switching between different policy types, log MLS status */
2079         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2080                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2081         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2082                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2083
2084         rc = policydb_load_isids(newpolicydb, &newsidtab);
2085         if (rc) {
2086                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2087                 policydb_destroy(newpolicydb);
2088                 goto out;
2089         }
2090
2091         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2092         if (rc)
2093                 goto err;
2094
2095         rc = security_preserve_bools(newpolicydb);
2096         if (rc) {
2097                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2098                 goto err;
2099         }
2100
2101         /* Clone the SID table. */
2102         sidtab_shutdown(&sidtab);
2103
2104         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2105         if (rc)
2106                 goto err;
2107
2108         /*
2109          * Convert the internal representations of contexts
2110          * in the new SID table.
2111          */
2112         args.oldp = &policydb;
2113         args.newp = newpolicydb;
2114         rc = sidtab_map(&newsidtab, convert_context, &args);
2115         if (rc) {
2116                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2117                         " representation of contexts in the new SID"
2118                         " table\n");
2119                 goto err;
2120         }
2121
2122         /* Save the old policydb and SID table to free later. */
2123         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2124         sidtab_set(&oldsidtab, &sidtab);
2125
2126         /* Install the new policydb and SID table. */
2127         write_lock_irq(&policy_rwlock);
2128         memcpy(&policydb, newpolicydb, sizeof(policydb));
2129         sidtab_set(&sidtab, &newsidtab);
2130         security_load_policycaps();
2131         oldmap = current_mapping;
2132         current_mapping = map;
2133         current_mapping_size = map_size;
2134         seqno = ++latest_granting;
2135         write_unlock_irq(&policy_rwlock);
2136
2137         /* Free the old policydb and SID table. */
2138         policydb_destroy(oldpolicydb);
2139         sidtab_destroy(&oldsidtab);
2140         kfree(oldmap);
2141
2142         avc_ss_reset(seqno);
2143         selnl_notify_policyload(seqno);
2144         selinux_status_update_policyload(seqno);
2145         selinux_netlbl_cache_invalidate();
2146         selinux_xfrm_notify_policyload();
2147
2148         rc = 0;
2149         goto out;
2150
2151 err:
2152         kfree(map);
2153         sidtab_destroy(&newsidtab);
2154         policydb_destroy(newpolicydb);
2155
2156 out:
2157         kfree(oldpolicydb);
2158         return rc;
2159 }
2160
2161 size_t security_policydb_len(void)
2162 {
2163         size_t len;
2164
2165         read_lock(&policy_rwlock);
2166         len = policydb.len;
2167         read_unlock(&policy_rwlock);
2168
2169         return len;
2170 }
2171
2172 /**
2173  * security_port_sid - Obtain the SID for a port.
2174  * @protocol: protocol number
2175  * @port: port number
2176  * @out_sid: security identifier
2177  */
2178 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2179 {
2180         struct ocontext *c;
2181         int rc = 0;
2182
2183         read_lock(&policy_rwlock);
2184
2185         c = policydb.ocontexts[OCON_PORT];
2186         while (c) {
2187                 if (c->u.port.protocol == protocol &&
2188                     c->u.port.low_port <= port &&
2189                     c->u.port.high_port >= port)
2190                         break;
2191                 c = c->next;
2192         }
2193
2194         if (c) {
2195                 if (!c->sid[0]) {
2196                         rc = sidtab_context_to_sid(&sidtab,
2197                                                    &c->context[0],
2198                                                    &c->sid[0]);
2199                         if (rc)
2200                                 goto out;
2201                 }
2202                 *out_sid = c->sid[0];
2203         } else {
2204                 *out_sid = SECINITSID_PORT;
2205         }
2206
2207 out:
2208         read_unlock(&policy_rwlock);
2209         return rc;
2210 }
2211
2212 /**
2213  * security_netif_sid - Obtain the SID for a network interface.
2214  * @name: interface name
2215  * @if_sid: interface SID
2216  */
2217 int security_netif_sid(char *name, u32 *if_sid)
2218 {
2219         int rc = 0;
2220         struct ocontext *c;
2221
2222         read_lock(&policy_rwlock);
2223
2224         c = policydb.ocontexts[OCON_NETIF];
2225         while (c) {
2226                 if (strcmp(name, c->u.name) == 0)
2227                         break;
2228                 c = c->next;
2229         }
2230
2231         if (c) {
2232                 if (!c->sid[0] || !c->sid[1]) {
2233                         rc = sidtab_context_to_sid(&sidtab,
2234                                                   &c->context[0],
2235                                                   &c->sid[0]);
2236                         if (rc)
2237                                 goto out;
2238                         rc = sidtab_context_to_sid(&sidtab,
2239                                                    &c->context[1],
2240                                                    &c->sid[1]);
2241                         if (rc)
2242                                 goto out;
2243                 }
2244                 *if_sid = c->sid[0];
2245         } else
2246                 *if_sid = SECINITSID_NETIF;
2247
2248 out:
2249         read_unlock(&policy_rwlock);
2250         return rc;
2251 }
2252
2253 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2254 {
2255         int i, fail = 0;
2256
2257         for (i = 0; i < 4; i++)
2258                 if (addr[i] != (input[i] & mask[i])) {
2259                         fail = 1;
2260                         break;
2261                 }
2262
2263         return !fail;
2264 }
2265
2266 /**
2267  * security_node_sid - Obtain the SID for a node (host).
2268  * @domain: communication domain aka address family
2269  * @addrp: address
2270  * @addrlen: address length in bytes
2271  * @out_sid: security identifier
2272  */
2273 int security_node_sid(u16 domain,
2274                       void *addrp,
2275                       u32 addrlen,
2276                       u32 *out_sid)
2277 {
2278         int rc;
2279         struct ocontext *c;
2280
2281         read_lock(&policy_rwlock);
2282
2283         switch (domain) {
2284         case AF_INET: {
2285                 u32 addr;
2286
2287                 rc = -EINVAL;
2288                 if (addrlen != sizeof(u32))
2289                         goto out;
2290
2291                 addr = *((u32 *)addrp);
2292
2293                 c = policydb.ocontexts[OCON_NODE];
2294                 while (c) {
2295                         if (c->u.node.addr == (addr & c->u.node.mask))
2296                                 break;
2297                         c = c->next;
2298                 }
2299                 break;
2300         }
2301
2302         case AF_INET6:
2303                 rc = -EINVAL;
2304                 if (addrlen != sizeof(u64) * 2)
2305                         goto out;
2306                 c = policydb.ocontexts[OCON_NODE6];
2307                 while (c) {
2308                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2309                                                 c->u.node6.mask))
2310                                 break;
2311                         c = c->next;
2312                 }
2313                 break;
2314
2315         default:
2316                 rc = 0;
2317                 *out_sid = SECINITSID_NODE;
2318                 goto out;
2319         }
2320
2321         if (c) {
2322                 if (!c->sid[0]) {
2323                         rc = sidtab_context_to_sid(&sidtab,
2324                                                    &c->context[0],
2325                                                    &c->sid[0]);
2326                         if (rc)
2327                                 goto out;
2328                 }
2329                 *out_sid = c->sid[0];
2330         } else {
2331                 *out_sid = SECINITSID_NODE;
2332         }
2333
2334         rc = 0;
2335 out:
2336         read_unlock(&policy_rwlock);
2337         return rc;
2338 }
2339
2340 #define SIDS_NEL 25
2341
2342 /**
2343  * security_get_user_sids - Obtain reachable SIDs for a user.
2344  * @fromsid: starting SID
2345  * @username: username
2346  * @sids: array of reachable SIDs for user
2347  * @nel: number of elements in @sids
2348  *
2349  * Generate the set of SIDs for legal security contexts
2350  * for a given user that can be reached by @fromsid.
2351  * Set *@sids to point to a dynamically allocated
2352  * array containing the set of SIDs.  Set *@nel to the
2353  * number of elements in the array.
2354  */
2355
2356 int security_get_user_sids(u32 fromsid,
2357                            char *username,
2358                            u32 **sids,
2359                            u32 *nel)
2360 {
2361         struct context *fromcon, usercon;
2362         u32 *mysids = NULL, *mysids2, sid;
2363         u32 mynel = 0, maxnel = SIDS_NEL;
2364         struct user_datum *user;
2365         struct role_datum *role;
2366         struct ebitmap_node *rnode, *tnode;
2367         int rc = 0, i, j;
2368
2369         *sids = NULL;
2370         *nel = 0;
2371
2372         if (!ss_initialized)
2373                 goto out;
2374
2375         read_lock(&policy_rwlock);
2376
2377         context_init(&usercon);
2378
2379         rc = -EINVAL;
2380         fromcon = sidtab_search(&sidtab, fromsid);
2381         if (!fromcon)
2382                 goto out_unlock;
2383
2384         rc = -EINVAL;
2385         user = hashtab_search(policydb.p_users.table, username);
2386         if (!user)
2387                 goto out_unlock;
2388
2389         usercon.user = user->value;
2390
2391         rc = -ENOMEM;
2392         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2393         if (!mysids)
2394                 goto out_unlock;
2395
2396         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2397                 role = policydb.role_val_to_struct[i];
2398                 usercon.role = i + 1;
2399                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2400                         usercon.type = j + 1;
2401
2402                         if (mls_setup_user_range(fromcon, user, &usercon))
2403                                 continue;
2404
2405                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2406                         if (rc)
2407                                 goto out_unlock;
2408                         if (mynel < maxnel) {
2409                                 mysids[mynel++] = sid;
2410                         } else {
2411                                 rc = -ENOMEM;
2412                                 maxnel += SIDS_NEL;
2413                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2414                                 if (!mysids2)
2415                                         goto out_unlock;
2416                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2417                                 kfree(mysids);
2418                                 mysids = mysids2;
2419                                 mysids[mynel++] = sid;
2420                         }
2421                 }
2422         }
2423         rc = 0;
2424 out_unlock:
2425         read_unlock(&policy_rwlock);
2426         if (rc || !mynel) {
2427                 kfree(mysids);
2428                 goto out;
2429         }
2430
2431         rc = -ENOMEM;
2432         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2433         if (!mysids2) {
2434                 kfree(mysids);
2435                 goto out;
2436         }
2437         for (i = 0, j = 0; i < mynel; i++) {
2438                 struct av_decision dummy_avd;
2439                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2440                                           SECCLASS_PROCESS, /* kernel value */
2441                                           PROCESS__TRANSITION, AVC_STRICT,
2442                                           &dummy_avd);
2443                 if (!rc)
2444                         mysids2[j++] = mysids[i];
2445                 cond_resched();
2446         }
2447         rc = 0;
2448         kfree(mysids);
2449         *sids = mysids2;
2450         *nel = j;
2451 out:
2452         return rc;
2453 }
2454
2455 /**
2456  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2457  * @fstype: filesystem type
2458  * @path: path from root of mount
2459  * @sclass: file security class
2460  * @sid: SID for path
2461  *
2462  * Obtain a SID to use for a file in a filesystem that
2463  * cannot support xattr or use a fixed labeling behavior like
2464  * transition SIDs or task SIDs.
2465  *
2466  * The caller must acquire the policy_rwlock before calling this function.
2467  */
2468 static inline int __security_genfs_sid(const char *fstype,
2469                                        char *path,
2470                                        u16 orig_sclass,
2471                                        u32 *sid)
2472 {
2473         int len;
2474         u16 sclass;
2475         struct genfs *genfs;
2476         struct ocontext *c;
2477         int rc, cmp = 0;
2478
2479         while (path[0] == '/' && path[1] == '/')
2480                 path++;
2481
2482         sclass = unmap_class(orig_sclass);
2483         *sid = SECINITSID_UNLABELED;
2484
2485         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2486                 cmp = strcmp(fstype, genfs->fstype);
2487                 if (cmp <= 0)
2488                         break;
2489         }
2490
2491         rc = -ENOENT;
2492         if (!genfs || cmp)
2493                 goto out;
2494
2495         for (c = genfs->head; c; c = c->next) {
2496                 len = strlen(c->u.name);
2497                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2498                     (strncmp(c->u.name, path, len) == 0))
2499                         break;
2500         }
2501
2502         rc = -ENOENT;
2503         if (!c)
2504                 goto out;
2505
2506         if (!c->sid[0]) {
2507                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2508                 if (rc)
2509                         goto out;
2510         }
2511
2512         *sid = c->sid[0];
2513         rc = 0;
2514 out:
2515         return rc;
2516 }
2517
2518 /**
2519  * security_genfs_sid - Obtain a SID for a file in a filesystem
2520  * @fstype: filesystem type
2521  * @path: path from root of mount
2522  * @sclass: file security class
2523  * @sid: SID for path
2524  *
2525  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2526  * it afterward.
2527  */
2528 int security_genfs_sid(const char *fstype,
2529                        char *path,
2530                        u16 orig_sclass,
2531                        u32 *sid)
2532 {
2533         int retval;
2534
2535         read_lock(&policy_rwlock);
2536         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2537         read_unlock(&policy_rwlock);
2538         return retval;
2539 }
2540
2541 /**
2542  * security_fs_use - Determine how to handle labeling for a filesystem.
2543  * @sb: superblock in question
2544  */
2545 int security_fs_use(struct super_block *sb)
2546 {
2547         int rc = 0;
2548         struct ocontext *c;
2549         struct superblock_security_struct *sbsec = sb->s_security;
2550         const char *fstype = sb->s_type->name;
2551
2552         read_lock(&policy_rwlock);
2553
2554         c = policydb.ocontexts[OCON_FSUSE];
2555         while (c) {
2556                 if (strcmp(fstype, c->u.name) == 0)
2557                         break;
2558                 c = c->next;
2559         }
2560
2561         if (c) {
2562                 sbsec->behavior = c->v.behavior;
2563                 if (!c->sid[0]) {
2564                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2565                                                    &c->sid[0]);
2566                         if (rc)
2567                                 goto out;
2568                 }
2569                 sbsec->sid = c->sid[0];
2570         } else {
2571                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2572                                           &sbsec->sid);
2573                 if (rc) {
2574                         sbsec->behavior = SECURITY_FS_USE_NONE;
2575                         rc = 0;
2576                 } else {
2577                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2578                 }
2579         }
2580
2581 out:
2582         read_unlock(&policy_rwlock);
2583         return rc;
2584 }
2585
2586 int security_get_bools(int *len, char ***names, int **values)
2587 {
2588         int i, rc;
2589
2590         read_lock(&policy_rwlock);
2591         *names = NULL;
2592         *values = NULL;
2593
2594         rc = 0;
2595         *len = policydb.p_bools.nprim;
2596         if (!*len)
2597                 goto out;
2598
2599         rc = -ENOMEM;
2600         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2601         if (!*names)
2602                 goto err;
2603
2604         rc = -ENOMEM;
2605         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2606         if (!*values)
2607                 goto err;
2608
2609         for (i = 0; i < *len; i++) {
2610                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2611
2612                 rc = -ENOMEM;
2613                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2614                 if (!(*names)[i])
2615                         goto err;
2616         }
2617         rc = 0;
2618 out:
2619         read_unlock(&policy_rwlock);
2620         return rc;
2621 err:
2622         if (*names) {
2623                 for (i = 0; i < *len; i++)
2624                         kfree((*names)[i]);
2625                 kfree(*names);
2626         }
2627         kfree(*values);
2628         *len = 0;
2629         *names = NULL;
2630         *values = NULL;
2631         goto out;
2632 }
2633
2634
2635 int security_set_bools(int len, int *values)
2636 {
2637         int i, rc;
2638         int lenp, seqno = 0;
2639         struct cond_node *cur;
2640
2641         write_lock_irq(&policy_rwlock);
2642
2643         rc = -EFAULT;
2644         lenp = policydb.p_bools.nprim;
2645         if (len != lenp)
2646                 goto out;
2647
2648         for (i = 0; i < len; i++) {
2649                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2650                         audit_log(current->audit_context, GFP_ATOMIC,
2651                                 AUDIT_MAC_CONFIG_CHANGE,
2652                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2653                                 sym_name(&policydb, SYM_BOOLS, i),
2654                                 !!values[i],
2655                                 policydb.bool_val_to_struct[i]->state,
2656                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2657                                 audit_get_sessionid(current));
2658                 }
2659                 if (values[i])
2660                         policydb.bool_val_to_struct[i]->state = 1;
2661                 else
2662                         policydb.bool_val_to_struct[i]->state = 0;
2663         }
2664
2665         for (cur = policydb.cond_list; cur; cur = cur->next) {
2666                 rc = evaluate_cond_node(&policydb, cur);
2667                 if (rc)
2668                         goto out;
2669         }
2670
2671         seqno = ++latest_granting;
2672         rc = 0;
2673 out:
2674         write_unlock_irq(&policy_rwlock);
2675         if (!rc) {
2676                 avc_ss_reset(seqno);
2677                 selnl_notify_policyload(seqno);
2678                 selinux_status_update_policyload(seqno);
2679                 selinux_xfrm_notify_policyload();
2680         }
2681         return rc;
2682 }
2683
2684 int security_get_bool_value(int bool)
2685 {
2686         int rc;
2687         int len;
2688
2689         read_lock(&policy_rwlock);
2690
2691         rc = -EFAULT;
2692         len = policydb.p_bools.nprim;
2693         if (bool >= len)
2694                 goto out;
2695
2696         rc = policydb.bool_val_to_struct[bool]->state;
2697 out:
2698         read_unlock(&policy_rwlock);
2699         return rc;
2700 }
2701
2702 static int security_preserve_bools(struct policydb *p)
2703 {
2704         int rc, nbools = 0, *bvalues = NULL, i;
2705         char **bnames = NULL;
2706         struct cond_bool_datum *booldatum;
2707         struct cond_node *cur;
2708
2709         rc = security_get_bools(&nbools, &bnames, &bvalues);
2710         if (rc)
2711                 goto out;
2712         for (i = 0; i < nbools; i++) {
2713                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2714                 if (booldatum)
2715                         booldatum->state = bvalues[i];
2716         }
2717         for (cur = p->cond_list; cur; cur = cur->next) {
2718                 rc = evaluate_cond_node(p, cur);
2719                 if (rc)
2720                         goto out;
2721         }
2722
2723 out:
2724         if (bnames) {
2725                 for (i = 0; i < nbools; i++)
2726                         kfree(bnames[i]);
2727         }
2728         kfree(bnames);
2729         kfree(bvalues);
2730         return rc;
2731 }
2732
2733 /*
2734  * security_sid_mls_copy() - computes a new sid based on the given
2735  * sid and the mls portion of mls_sid.
2736  */
2737 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2738 {
2739         struct context *context1;
2740         struct context *context2;
2741         struct context newcon;
2742         char *s;
2743         u32 len;
2744         int rc;
2745
2746         rc = 0;
2747         if (!ss_initialized || !policydb.mls_enabled) {
2748                 *new_sid = sid;
2749                 goto out;
2750         }
2751
2752         context_init(&newcon);
2753
2754         read_lock(&policy_rwlock);
2755
2756         rc = -EINVAL;
2757         context1 = sidtab_search(&sidtab, sid);
2758         if (!context1) {
2759                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2760                         __func__, sid);
2761                 goto out_unlock;
2762         }
2763
2764         rc = -EINVAL;
2765         context2 = sidtab_search(&sidtab, mls_sid);
2766         if (!context2) {
2767                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2768                         __func__, mls_sid);
2769                 goto out_unlock;
2770         }
2771
2772         newcon.user = context1->user;
2773         newcon.role = context1->role;
2774         newcon.type = context1->type;
2775         rc = mls_context_cpy(&newcon, context2);
2776         if (rc)
2777                 goto out_unlock;
2778
2779         /* Check the validity of the new context. */
2780         if (!policydb_context_isvalid(&policydb, &newcon)) {
2781                 rc = convert_context_handle_invalid_context(&newcon);
2782                 if (rc) {
2783                         if (!context_struct_to_string(&newcon, &s, &len)) {
2784                                 audit_log(current->audit_context,
2785                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2786                                           "op=security_sid_mls_copy "
2787                                           "invalid_context=%s", s);
2788                                 kfree(s);
2789                         }
2790                         goto out_unlock;
2791                 }
2792         }
2793
2794         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2795 out_unlock:
2796         read_unlock(&policy_rwlock);
2797         context_destroy(&newcon);
2798 out:
2799         return rc;
2800 }
2801
2802 /**
2803  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2804  * @nlbl_sid: NetLabel SID
2805  * @nlbl_type: NetLabel labeling protocol type
2806  * @xfrm_sid: XFRM SID
2807  *
2808  * Description:
2809  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2810  * resolved into a single SID it is returned via @peer_sid and the function
2811  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2812  * returns a negative value.  A table summarizing the behavior is below:
2813  *
2814  *                                 | function return |      @sid
2815  *   ------------------------------+-----------------+-----------------
2816  *   no peer labels                |        0        |    SECSID_NULL
2817  *   single peer label             |        0        |    <peer_label>
2818  *   multiple, consistent labels   |        0        |    <peer_label>
2819  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2820  *
2821  */
2822 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2823                                  u32 xfrm_sid,
2824                                  u32 *peer_sid)
2825 {
2826         int rc;
2827         struct context *nlbl_ctx;
2828         struct context *xfrm_ctx;
2829
2830         *peer_sid = SECSID_NULL;
2831
2832         /* handle the common (which also happens to be the set of easy) cases
2833          * right away, these two if statements catch everything involving a
2834          * single or absent peer SID/label */
2835         if (xfrm_sid == SECSID_NULL) {
2836                 *peer_sid = nlbl_sid;
2837                 return 0;
2838         }
2839         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2840          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2841          * is present */
2842         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2843                 *peer_sid = xfrm_sid;
2844                 return 0;
2845         }
2846
2847         /* we don't need to check ss_initialized here since the only way both
2848          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2849          * security server was initialized and ss_initialized was true */
2850         if (!policydb.mls_enabled)
2851                 return 0;
2852
2853         read_lock(&policy_rwlock);
2854
2855         rc = -EINVAL;
2856         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2857         if (!nlbl_ctx) {
2858                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2859                        __func__, nlbl_sid);
2860                 goto out;
2861         }
2862         rc = -EINVAL;
2863         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2864         if (!xfrm_ctx) {
2865                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2866                        __func__, xfrm_sid);
2867                 goto out;
2868         }
2869         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2870         if (rc)
2871                 goto out;
2872
2873         /* at present NetLabel SIDs/labels really only carry MLS
2874          * information so if the MLS portion of the NetLabel SID
2875          * matches the MLS portion of the labeled XFRM SID/label
2876          * then pass along the XFRM SID as it is the most
2877          * expressive */
2878         *peer_sid = xfrm_sid;
2879 out:
2880         read_unlock(&policy_rwlock);
2881         return rc;
2882 }
2883
2884 static int get_classes_callback(void *k, void *d, void *args)
2885 {
2886         struct class_datum *datum = d;
2887         char *name = k, **classes = args;
2888         int value = datum->value - 1;
2889
2890         classes[value] = kstrdup(name, GFP_ATOMIC);
2891         if (!classes[value])
2892                 return -ENOMEM;
2893
2894         return 0;
2895 }
2896
2897 int security_get_classes(char ***classes, int *nclasses)
2898 {
2899         int rc;
2900
2901         read_lock(&policy_rwlock);
2902
2903         rc = -ENOMEM;
2904         *nclasses = policydb.p_classes.nprim;
2905         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2906         if (!*classes)
2907                 goto out;
2908
2909         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2910                         *classes);
2911         if (rc) {
2912                 int i;
2913                 for (i = 0; i < *nclasses; i++)
2914                         kfree((*classes)[i]);
2915                 kfree(*classes);
2916         }
2917
2918 out:
2919         read_unlock(&policy_rwlock);
2920         return rc;
2921 }
2922
2923 static int get_permissions_callback(void *k, void *d, void *args)
2924 {
2925         struct perm_datum *datum = d;
2926         char *name = k, **perms = args;
2927         int value = datum->value - 1;
2928
2929         perms[value] = kstrdup(name, GFP_ATOMIC);
2930         if (!perms[value])
2931                 return -ENOMEM;
2932
2933         return 0;
2934 }
2935
2936 int security_get_permissions(char *class, char ***perms, int *nperms)
2937 {
2938         int rc, i;
2939         struct class_datum *match;
2940
2941         read_lock(&policy_rwlock);
2942
2943         rc = -EINVAL;
2944         match = hashtab_search(policydb.p_classes.table, class);
2945         if (!match) {
2946                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2947                         __func__, class);
2948                 goto out;
2949         }
2950
2951         rc = -ENOMEM;
2952         *nperms = match->permissions.nprim;
2953         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2954         if (!*perms)
2955                 goto out;
2956
2957         if (match->comdatum) {
2958                 rc = hashtab_map(match->comdatum->permissions.table,
2959                                 get_permissions_callback, *perms);
2960                 if (rc)
2961                         goto err;
2962         }
2963
2964         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2965                         *perms);
2966         if (rc)
2967                 goto err;
2968
2969 out:
2970         read_unlock(&policy_rwlock);
2971         return rc;
2972
2973 err:
2974         read_unlock(&policy_rwlock);
2975         for (i = 0; i < *nperms; i++)
2976                 kfree((*perms)[i]);
2977         kfree(*perms);
2978         return rc;
2979 }
2980
2981 int security_get_reject_unknown(void)
2982 {
2983         return policydb.reject_unknown;
2984 }
2985
2986 int security_get_allow_unknown(void)
2987 {
2988         return policydb.allow_unknown;
2989 }
2990
2991 /**
2992  * security_policycap_supported - Check for a specific policy capability
2993  * @req_cap: capability
2994  *
2995  * Description:
2996  * This function queries the currently loaded policy to see if it supports the
2997  * capability specified by @req_cap.  Returns true (1) if the capability is
2998  * supported, false (0) if it isn't supported.
2999  *
3000  */
3001 int security_policycap_supported(unsigned int req_cap)
3002 {
3003         int rc;
3004
3005         read_lock(&policy_rwlock);
3006         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3007         read_unlock(&policy_rwlock);
3008
3009         return rc;
3010 }
3011
3012 struct selinux_audit_rule {
3013         u32 au_seqno;
3014         struct context au_ctxt;
3015 };
3016
3017 void selinux_audit_rule_free(void *vrule)
3018 {
3019         struct selinux_audit_rule *rule = vrule;
3020
3021         if (rule) {
3022                 context_destroy(&rule->au_ctxt);
3023                 kfree(rule);
3024         }
3025 }
3026
3027 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3028 {
3029         struct selinux_audit_rule *tmprule;
3030         struct role_datum *roledatum;
3031         struct type_datum *typedatum;
3032         struct user_datum *userdatum;
3033         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3034         int rc = 0;
3035
3036         *rule = NULL;
3037
3038         if (!ss_initialized)
3039                 return -EOPNOTSUPP;
3040
3041         switch (field) {
3042         case AUDIT_SUBJ_USER:
3043         case AUDIT_SUBJ_ROLE:
3044         case AUDIT_SUBJ_TYPE:
3045         case AUDIT_OBJ_USER:
3046         case AUDIT_OBJ_ROLE:
3047         case AUDIT_OBJ_TYPE:
3048                 /* only 'equals' and 'not equals' fit user, role, and type */
3049                 if (op != Audit_equal && op != Audit_not_equal)
3050                         return -EINVAL;
3051                 break;
3052         case AUDIT_SUBJ_SEN:
3053         case AUDIT_SUBJ_CLR:
3054         case AUDIT_OBJ_LEV_LOW:
3055         case AUDIT_OBJ_LEV_HIGH:
3056                 /* we do not allow a range, indicated by the presence of '-' */
3057                 if (strchr(rulestr, '-'))
3058                         return -EINVAL;
3059                 break;
3060         default:
3061                 /* only the above fields are valid */
3062                 return -EINVAL;
3063         }
3064
3065         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3066         if (!tmprule)
3067                 return -ENOMEM;
3068
3069         context_init(&tmprule->au_ctxt);
3070
3071         read_lock(&policy_rwlock);
3072
3073         tmprule->au_seqno = latest_granting;
3074
3075         switch (field) {
3076         case AUDIT_SUBJ_USER:
3077         case AUDIT_OBJ_USER:
3078                 rc = -EINVAL;
3079                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3080                 if (!userdatum)
3081                         goto out;
3082                 tmprule->au_ctxt.user = userdatum->value;
3083                 break;
3084         case AUDIT_SUBJ_ROLE:
3085         case AUDIT_OBJ_ROLE:
3086                 rc = -EINVAL;
3087                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3088                 if (!roledatum)
3089                         goto out;
3090                 tmprule->au_ctxt.role = roledatum->value;
3091                 break;
3092         case AUDIT_SUBJ_TYPE:
3093         case AUDIT_OBJ_TYPE:
3094                 rc = -EINVAL;
3095                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3096                 if (!typedatum)
3097                         goto out;
3098                 tmprule->au_ctxt.type = typedatum->value;
3099                 break;
3100         case AUDIT_SUBJ_SEN:
3101         case AUDIT_SUBJ_CLR:
3102         case AUDIT_OBJ_LEV_LOW:
3103         case AUDIT_OBJ_LEV_HIGH:
3104                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3105                 if (rc)
3106                         goto out;
3107                 break;
3108         }
3109         rc = 0;
3110 out:
3111         read_unlock(&policy_rwlock);
3112
3113         if (rc) {
3114                 selinux_audit_rule_free(tmprule);
3115                 tmprule = NULL;
3116         }
3117
3118         *rule = tmprule;
3119
3120         return rc;
3121 }
3122
3123 /* Check to see if the rule contains any selinux fields */
3124 int selinux_audit_rule_known(struct audit_krule *rule)
3125 {
3126         int i;
3127
3128         for (i = 0; i < rule->field_count; i++) {
3129                 struct audit_field *f = &rule->fields[i];
3130                 switch (f->type) {
3131                 case AUDIT_SUBJ_USER:
3132                 case AUDIT_SUBJ_ROLE:
3133                 case AUDIT_SUBJ_TYPE:
3134                 case AUDIT_SUBJ_SEN:
3135                 case AUDIT_SUBJ_CLR:
3136                 case AUDIT_OBJ_USER:
3137                 case AUDIT_OBJ_ROLE:
3138                 case AUDIT_OBJ_TYPE:
3139                 case AUDIT_OBJ_LEV_LOW:
3140                 case AUDIT_OBJ_LEV_HIGH:
3141                         return 1;
3142                 }
3143         }
3144
3145         return 0;
3146 }
3147
3148 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3149                              struct audit_context *actx)
3150 {
3151         struct context *ctxt;
3152         struct mls_level *level;
3153         struct selinux_audit_rule *rule = vrule;
3154         int match = 0;
3155
3156         if (unlikely(!rule)) {
3157                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3158                 return -ENOENT;
3159         }
3160
3161         read_lock(&policy_rwlock);
3162
3163         if (rule->au_seqno < latest_granting) {
3164                 match = -ESTALE;
3165                 goto out;
3166         }
3167
3168         ctxt = sidtab_search(&sidtab, sid);
3169         if (unlikely(!ctxt)) {
3170                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3171                           sid);
3172                 match = -ENOENT;
3173                 goto out;
3174         }
3175
3176         /* a field/op pair that is not caught here will simply fall through
3177            without a match */
3178         switch (field) {
3179         case AUDIT_SUBJ_USER:
3180         case AUDIT_OBJ_USER:
3181                 switch (op) {
3182                 case Audit_equal:
3183                         match = (ctxt->user == rule->au_ctxt.user);
3184                         break;
3185                 case Audit_not_equal:
3186                         match = (ctxt->user != rule->au_ctxt.user);
3187                         break;
3188                 }
3189                 break;
3190         case AUDIT_SUBJ_ROLE:
3191         case AUDIT_OBJ_ROLE:
3192                 switch (op) {
3193                 case Audit_equal:
3194                         match = (ctxt->role == rule->au_ctxt.role);
3195                         break;
3196                 case Audit_not_equal:
3197                         match = (ctxt->role != rule->au_ctxt.role);
3198                         break;
3199                 }
3200                 break;
3201         case AUDIT_SUBJ_TYPE:
3202         case AUDIT_OBJ_TYPE:
3203                 switch (op) {
3204                 case Audit_equal:
3205                         match = (ctxt->type == rule->au_ctxt.type);
3206                         break;
3207                 case Audit_not_equal:
3208                         match = (ctxt->type != rule->au_ctxt.type);
3209                         break;
3210                 }
3211                 break;
3212         case AUDIT_SUBJ_SEN:
3213         case AUDIT_SUBJ_CLR:
3214         case AUDIT_OBJ_LEV_LOW:
3215         case AUDIT_OBJ_LEV_HIGH:
3216                 level = ((field == AUDIT_SUBJ_SEN ||
3217                           field == AUDIT_OBJ_LEV_LOW) ?
3218                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3219                 switch (op) {
3220                 case Audit_equal:
3221                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3222                                              level);
3223                         break;
3224                 case Audit_not_equal:
3225                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3226                                               level);
3227                         break;
3228                 case Audit_lt:
3229                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3230                                                level) &&
3231                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3232                                                level));
3233                         break;
3234                 case Audit_le:
3235                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3236                                               level);
3237                         break;
3238                 case Audit_gt:
3239                         match = (mls_level_dom(level,
3240                                               &rule->au_ctxt.range.level[0]) &&
3241                                  !mls_level_eq(level,
3242                                                &rule->au_ctxt.range.level[0]));
3243                         break;
3244                 case Audit_ge:
3245                         match = mls_level_dom(level,
3246                                               &rule->au_ctxt.range.level[0]);
3247                         break;
3248                 }
3249         }
3250
3251 out:
3252         read_unlock(&policy_rwlock);
3253         return match;
3254 }
3255
3256 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3257
3258 static int aurule_avc_callback(u32 event)
3259 {
3260         int err = 0;
3261
3262         if (event == AVC_CALLBACK_RESET && aurule_callback)
3263                 err = aurule_callback();
3264         return err;
3265 }
3266
3267 static int __init aurule_init(void)
3268 {
3269         int err;
3270
3271         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3272         if (err)
3273                 panic("avc_add_callback() failed, error %d\n", err);
3274
3275         return err;
3276 }
3277 __initcall(aurule_init);
3278
3279 #ifdef CONFIG_NETLABEL
3280 /**
3281  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3282  * @secattr: the NetLabel packet security attributes
3283  * @sid: the SELinux SID
3284  *
3285  * Description:
3286  * Attempt to cache the context in @ctx, which was derived from the packet in
3287  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3288  * already been initialized.
3289  *
3290  */
3291 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3292                                       u32 sid)
3293 {
3294         u32 *sid_cache;
3295
3296         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3297         if (sid_cache == NULL)
3298                 return;
3299         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3300         if (secattr->cache == NULL) {
3301                 kfree(sid_cache);
3302                 return;
3303         }
3304
3305         *sid_cache = sid;
3306         secattr->cache->free = kfree;
3307         secattr->cache->data = sid_cache;
3308         secattr->flags |= NETLBL_SECATTR_CACHE;
3309 }
3310
3311 /**
3312  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3313  * @secattr: the NetLabel packet security attributes
3314  * @sid: the SELinux SID
3315  *
3316  * Description:
3317  * Convert the given NetLabel security attributes in @secattr into a
3318  * SELinux SID.  If the @secattr field does not contain a full SELinux
3319  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3320  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3321  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3322  * conversion for future lookups.  Returns zero on success, negative values on
3323  * failure.
3324  *
3325  */
3326 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3327                                    u32 *sid)
3328 {
3329         int rc;
3330         struct context *ctx;
3331         struct context ctx_new;
3332
3333         if (!ss_initialized) {
3334                 *sid = SECSID_NULL;
3335                 return 0;
3336         }
3337
3338         read_lock(&policy_rwlock);
3339
3340         if (secattr->flags & NETLBL_SECATTR_CACHE)
3341                 *sid = *(u32 *)secattr->cache->data;
3342         else if (secattr->flags & NETLBL_SECATTR_SECID)
3343                 *sid = secattr->attr.secid;
3344         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3345                 rc = -EIDRM;
3346                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3347                 if (ctx == NULL)
3348                         goto out;
3349
3350                 context_init(&ctx_new);
3351                 ctx_new.user = ctx->user;
3352                 ctx_new.role = ctx->role;
3353                 ctx_new.type = ctx->type;
3354                 mls_import_netlbl_lvl(&ctx_new, secattr);
3355                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3356                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3357                         if (rc)
3358                                 goto out;
3359                 }
3360                 rc = -EIDRM;
3361                 if (!mls_context_isvalid(&policydb, &ctx_new))
3362                         goto out_free;
3363
3364                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3365                 if (rc)
3366                         goto out_free;
3367
3368                 security_netlbl_cache_add(secattr, *sid);
3369
3370                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3371         } else
3372                 *sid = SECSID_NULL;
3373
3374         read_unlock(&policy_rwlock);
3375         return 0;
3376 out_free:
3377         ebitmap_destroy(&ctx_new.range.level[0].cat);
3378 out:
3379         read_unlock(&policy_rwlock);
3380         return rc;
3381 }
3382
3383 /**
3384  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3385  * @sid: the SELinux SID
3386  * @secattr: the NetLabel packet security attributes
3387  *
3388  * Description:
3389  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3390  * Returns zero on success, negative values on failure.
3391  *
3392  */
3393 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3394 {
3395         int rc;
3396         struct context *ctx;
3397
3398         if (!ss_initialized)
3399                 return 0;
3400
3401         read_lock(&policy_rwlock);
3402
3403         rc = -ENOENT;
3404         ctx = sidtab_search(&sidtab, sid);
3405         if (ctx == NULL)
3406                 goto out;
3407
3408         rc = -ENOMEM;
3409         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3410                                   GFP_ATOMIC);
3411         if (secattr->domain == NULL)
3412                 goto out;
3413
3414         secattr->attr.secid = sid;
3415         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3416         mls_export_netlbl_lvl(ctx, secattr);
3417         rc = mls_export_netlbl_cat(ctx, secattr);
3418 out:
3419         read_unlock(&policy_rwlock);
3420         return rc;
3421 }
3422 #endif /* CONFIG_NETLABEL */
3423
3424 /**
3425  * security_read_policy - read the policy.
3426  * @data: binary policy data
3427  * @len: length of data in bytes
3428  *
3429  */
3430 int security_read_policy(void **data, size_t *len)
3431 {
3432         int rc;
3433         struct policy_file fp;
3434
3435         if (!ss_initialized)
3436                 return -EINVAL;
3437
3438         *len = security_policydb_len();
3439
3440         *data = vmalloc_user(*len);
3441         if (!*data)
3442                 return -ENOMEM;
3443
3444         fp.data = *data;
3445         fp.len = *len;
3446
3447         read_lock(&policy_rwlock);
3448         rc = policydb_write(&policydb, &fp);
3449         read_unlock(&policy_rwlock);
3450
3451         if (rc)
3452                 return rc;
3453
3454         *len = (unsigned long)fp.data - (unsigned long)*data;
3455         return 0;
3456
3457 }