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
  76 static DEFINE_RWLOCK(policy_rwlock);
  77
  78 static struct sidtab sidtab;
  79 struct policydb policydb;
  80 int ss_initialized;
  81
  82 /*
  83  * The largest sequence number that has been used when
  84  * providing an access decision to the access vector cache.
  85  * The sequence number only changes when a policy change
  86  * occurs.
  87  */
  88 static u32 latest_granting;
  89
  90 /* Forward declaration. */
  91 static int context_struct_to_string(struct context *context, char **scontext,
  92                                     u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct context *scontext,
  95                                         struct context *tcontext,
  96                                         u16 tclass,
  97                                         struct av_decision *avd,
  98                                         struct operation *ops);
  99
 100 struct selinux_mapping {
 101         u16 value; /* policy value */
 102         unsigned num_perms;
 103         u32 perms[sizeof(u32) * 8];
 104 };
 105
 106 static struct selinux_mapping *current_mapping;
 107 static u16 current_mapping_size;
 108
 109 static int selinux_set_mapping(struct policydb *pol,
 110                                struct security_class_mapping *map,
 111                                struct selinux_mapping **out_map_p,
 112                                u16 *out_map_size)
 113 {
 114         struct selinux_mapping *out_map = NULL;
 115         size_t size = sizeof(struct selinux_mapping);
 116         u16 i, j;
 117         unsigned k;
 118         bool print_unknown_handle = false;
 119
 120         /* Find number of classes in the input mapping */
 121         if (!map)
 122                 return -EINVAL;
 123         i = 0;
 124         while (map[i].name)
 125                 i++;
 126
 127         /* Allocate space for the class records, plus one for class zero */
 128         out_map = kcalloc(++i, size, GFP_ATOMIC);
 129         if (!out_map)
 130                 return -ENOMEM;
 131
 132         /* Store the raw class and permission values */
 133         j = 0;
 134         while (map[j].name) {
 135                 struct security_class_mapping *p_in = map + (j++);
 136                 struct selinux_mapping *p_out = out_map + j;
 137
 138                 /* An empty class string skips ahead */
 139                 if (!strcmp(p_in->name, "")) {
 140                         p_out->num_perms = 0;
 141                         continue;
 142                 }
 143
 144                 p_out->value = string_to_security_class(pol, p_in->name);
 145                 if (!p_out->value) {
 146                         printk(KERN_INFO
 147                                "SELinux:  Class %s not defined in policy.\n",
 148                                p_in->name);
 149                         if (pol->reject_unknown)
 150                                 goto err;
 151                         p_out->num_perms = 0;
 152                         print_unknown_handle = true;
 153                         continue;
 154                 }
 155
 156                 k = 0;
 157                 while (p_in->perms && p_in->perms[k]) {
 158                         /* An empty permission string skips ahead */
 159                         if (!*p_in->perms[k]) {
 160                                 k++;
 161                                 continue;
 162                         }
 163                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 164                                                             p_in->perms[k]);
 165                         if (!p_out->perms[k]) {
 166                                 printk(KERN_INFO
 167                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 168                                        p_in->perms[k], p_in->name);
 169                                 if (pol->reject_unknown)
 170                                         goto err;
 171                                 print_unknown_handle = true;
 172                         }
 173
 174                         k++;
 175                 }
 176                 p_out->num_perms = k;
 177         }
 178
 179         if (print_unknown_handle)
 180                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 181                        pol->allow_unknown ? "allowed" : "denied");
 182
 183         *out_map_p = out_map;
 184         *out_map_size = i;
 185         return 0;
 186 err:
 187         kfree(out_map);
 188         return -EINVAL;
 189 }
 190
 191 /*
 192  * Get real, policy values from mapped values
 193  */
 194
 195 static u16 unmap_class(u16 tclass)
 196 {
 197         if (tclass < current_mapping_size)
 198                 return current_mapping[tclass].value;
 199
 200         return tclass;
 201 }
 202
 203 /*
 204  * Get kernel value for class from its policy value
 205  */
 206 static u16 map_class(u16 pol_value)
 207 {
 208         u16 i;
 209
 210         for (i = 1; i < current_mapping_size; i++) {
 211                 if (current_mapping[i].value == pol_value)
 212                         return i;
 213         }
 214
 215         return SECCLASS_NULL;
 216 }
 217
 218 static void map_decision(u16 tclass, struct av_decision *avd,
 219                          int allow_unknown)
 220 {
 221         if (tclass < current_mapping_size) {
 222                 unsigned i, n = current_mapping[tclass].num_perms;
 223                 u32 result;
 224
 225                 for (i = 0, result = 0; i < n; i++) {
 226                         if (avd->allowed & current_mapping[tclass].perms[i])
 227                                 result |= 1<<i;
 228                         if (allow_unknown && !current_mapping[tclass].perms[i])
 229                                 result |= 1<<i;
 230                 }
 231                 avd->allowed = result;
 232
 233                 for (i = 0, result = 0; i < n; i++)
 234                         if (avd->auditallow & current_mapping[tclass].perms[i])
 235                                 result |= 1<<i;
 236                 avd->auditallow = result;
 237
 238                 for (i = 0, result = 0; i < n; i++) {
 239                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 240                                 result |= 1<<i;
 241                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 242                                 result |= 1<<i;
 243                 }
 244                 /*
 245                  * In case the kernel has a bug and requests a permission
 246                  * between num_perms and the maximum permission number, we
 247                  * should audit that denial
 248                  */
 249                 for (; i < (sizeof(u32)*8); i++)
 250                         result |= 1<<i;
 251                 avd->auditdeny = result;
 252         }
 253 }
 254
 255 int security_mls_enabled(void)
 256 {
 257         return policydb.mls_enabled;
 258 }
 259
 260 /*
 261  * Return the boolean value of a constraint expression
 262  * when it is applied to the specified source and target
 263  * security contexts.
 264  *
 265  * xcontext is a special beast...  It is used by the validatetrans rules
 266  * only.  For these rules, scontext is the context before the transition,
 267  * tcontext is the context after the transition, and xcontext is the context
 268  * of the process performing the transition.  All other callers of
 269  * constraint_expr_eval should pass in NULL for xcontext.
 270  */
 271 static int constraint_expr_eval(struct context *scontext,
 272                                 struct context *tcontext,
 273                                 struct context *xcontext,
 274                                 struct constraint_expr *cexpr)
 275 {
 276         u32 val1, val2;
 277         struct context *c;
 278         struct role_datum *r1, *r2;
 279         struct mls_level *l1, *l2;
 280         struct constraint_expr *e;
 281         int s[CEXPR_MAXDEPTH];
 282         int sp = -1;
 283
 284         for (e = cexpr; e; e = e->next) {
 285                 switch (e->expr_type) {
 286                 case CEXPR_NOT:
 287                         BUG_ON(sp < 0);
 288                         s[sp] = !s[sp];
 289                         break;
 290                 case CEXPR_AND:
 291                         BUG_ON(sp < 1);
 292                         sp--;
 293                         s[sp] &= s[sp + 1];
 294                         break;
 295                 case CEXPR_OR:
 296                         BUG_ON(sp < 1);
 297                         sp--;
 298                         s[sp] |= s[sp + 1];
 299                         break;
 300                 case CEXPR_ATTR:
 301                         if (sp == (CEXPR_MAXDEPTH - 1))
 302                                 return 0;
 303                         switch (e->attr) {
 304                         case CEXPR_USER:
 305                                 val1 = scontext->user;
 306                                 val2 = tcontext->user;
 307                                 break;
 308                         case CEXPR_TYPE:
 309                                 val1 = scontext->type;
 310                                 val2 = tcontext->type;
 311                                 break;
 312                         case CEXPR_ROLE:
 313                                 val1 = scontext->role;
 314                                 val2 = tcontext->role;
 315                                 r1 = policydb.role_val_to_struct[val1 - 1];
 316                                 r2 = policydb.role_val_to_struct[val2 - 1];
 317                                 switch (e->op) {
 318                                 case CEXPR_DOM:
 319                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 320                                                                   val2 - 1);
 321                                         continue;
 322                                 case CEXPR_DOMBY:
 323                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 324                                                                   val1 - 1);
 325                                         continue;
 326                                 case CEXPR_INCOMP:
 327                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 328                                                                     val2 - 1) &&
 329                                                    !ebitmap_get_bit(&r2->dominates,
 330                                                                     val1 - 1));
 331                                         continue;
 332                                 default:
 333                                         break;
 334                                 }
 335                                 break;
 336                         case CEXPR_L1L2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_L1H2:
 341                                 l1 = &(scontext->range.level[0]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1L2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[0]);
 347                                 goto mls_ops;
 348                         case CEXPR_H1H2:
 349                                 l1 = &(scontext->range.level[1]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L1H1:
 353                                 l1 = &(scontext->range.level[0]);
 354                                 l2 = &(scontext->range.level[1]);
 355                                 goto mls_ops;
 356                         case CEXPR_L2H2:
 357                                 l1 = &(tcontext->range.level[0]);
 358                                 l2 = &(tcontext->range.level[1]);
 359                                 goto mls_ops;
 360 mls_ops:
 361                         switch (e->op) {
 362                         case CEXPR_EQ:
 363                                 s[++sp] = mls_level_eq(l1, l2);
 364                                 continue;
 365                         case CEXPR_NEQ:
 366                                 s[++sp] = !mls_level_eq(l1, l2);
 367                                 continue;
 368                         case CEXPR_DOM:
 369                                 s[++sp] = mls_level_dom(l1, l2);
 370                                 continue;
 371                         case CEXPR_DOMBY:
 372                                 s[++sp] = mls_level_dom(l2, l1);
 373                                 continue;
 374                         case CEXPR_INCOMP:
 375                                 s[++sp] = mls_level_incomp(l2, l1);
 376                                 continue;
 377                         default:
 378                                 BUG();
 379                                 return 0;
 380                         }
 381                         break;
 382                         default:
 383                                 BUG();
 384                                 return 0;
 385                         }
 386
 387                         switch (e->op) {
 388                         case CEXPR_EQ:
 389                                 s[++sp] = (val1 == val2);
 390                                 break;
 391                         case CEXPR_NEQ:
 392                                 s[++sp] = (val1 != val2);
 393                                 break;
 394                         default:
 395                                 BUG();
 396                                 return 0;
 397                         }
 398                         break;
 399                 case CEXPR_NAMES:
 400                         if (sp == (CEXPR_MAXDEPTH-1))
 401                                 return 0;
 402                         c = scontext;
 403                         if (e->attr & CEXPR_TARGET)
 404                                 c = tcontext;
 405                         else if (e->attr & CEXPR_XTARGET) {
 406                                 c = xcontext;
 407                                 if (!c) {
 408                                         BUG();
 409                                         return 0;
 410                                 }
 411                         }
 412                         if (e->attr & CEXPR_USER)
 413                                 val1 = c->user;
 414                         else if (e->attr & CEXPR_ROLE)
 415                                 val1 = c->role;
 416                         else if (e->attr & CEXPR_TYPE)
 417                                 val1 = c->type;
 418                         else {
 419                                 BUG();
 420                                 return 0;
 421                         }
 422
 423                         switch (e->op) {
 424                         case CEXPR_EQ:
 425                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         case CEXPR_NEQ:
 428                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         default:
 431                                 BUG();
 432                                 return 0;
 433                         }
 434                         break;
 435                 default:
 436                         BUG();
 437                         return 0;
 438                 }
 439         }
 440
 441         BUG_ON(sp != 0);
 442         return s[0];
 443 }
 444
 445 /*
 446  * security_dump_masked_av - dumps masked permissions during
 447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 448  */
 449 static int dump_masked_av_helper(void *k, void *d, void *args)
 450 {
 451         struct perm_datum *pdatum = d;
 452         char **permission_names = args;
 453
 454         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 455
 456         permission_names[pdatum->value - 1] = (char *)k;
 457
 458         return 0;
 459 }
 460
 461 static void security_dump_masked_av(struct context *scontext,
 462                                     struct context *tcontext,
 463                                     u16 tclass,
 464                                     u32 permissions,
 465                                     const char *reason)
 466 {
 467         struct common_datum *common_dat;
 468         struct class_datum *tclass_dat;
 469         struct audit_buffer *ab;
 470         char *tclass_name;
 471         char *scontext_name = NULL;
 472         char *tcontext_name = NULL;
 473         char *permission_names[32];
 474         int index;
 475         u32 length;
 476         bool need_comma = false;
 477
 478         if (!permissions)
 479                 return;
 480
 481         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 482         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 483         common_dat = tclass_dat->comdatum;
 484
 485         /* init permission_names */
 486         if (common_dat &&
 487             hashtab_map(common_dat->permissions.table,
 488                         dump_masked_av_helper, permission_names) < 0)
 489                 goto out;
 490
 491         if (hashtab_map(tclass_dat->permissions.table,
 492                         dump_masked_av_helper, permission_names) < 0)
 493                 goto out;
 494
 495         /* get scontext/tcontext in text form */
 496         if (context_struct_to_string(scontext,
 497                                      &scontext_name, &length) < 0)
 498                 goto out;
 499
 500         if (context_struct_to_string(tcontext,
 501                                      &tcontext_name, &length) < 0)
 502                 goto out;
 503
 504         /* audit a message */
 505         ab = audit_log_start(current->audit_context,
 506                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 507         if (!ab)
 508                 goto out;
 509
 510         audit_log_format(ab, "op=security_compute_av reason=%s "
 511                          "scontext=%s tcontext=%s tclass=%s perms=",
 512                          reason, scontext_name, tcontext_name, tclass_name);
 513
 514         for (index = 0; index < 32; index++) {
 515                 u32 mask = (1 << index);
 516
 517                 if ((mask & permissions) == 0)
 518                         continue;
 519
 520                 audit_log_format(ab, "%s%s",
 521                                  need_comma ? "," : "",
 522                                  permission_names[index]
 523                                  ? permission_names[index] : "????");
 524                 need_comma = true;
 525         }
 526         audit_log_end(ab);
 527 out:
 528         /* release scontext/tcontext */
 529         kfree(tcontext_name);
 530         kfree(scontext_name);
 531
 532         return;
 533 }
 534
 535 /*
 536  * security_boundary_permission - drops violated permissions
 537  * on boundary constraint.
 538  */
 539 static void type_attribute_bounds_av(struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 552                                     scontext->type - 1);
 553         BUG_ON(!source);
 554
 555         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 556                                     tcontext->type - 1);
 557         BUG_ON(!target);
 558
 559         if (source->bounds) {
 560                 memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563                 lo_scontext.type = source->bounds;
 564
 565                 context_struct_compute_av(&lo_scontext,
 566                                           tcontext,
 567                                           tclass,
 568                                           &lo_avd,
 569                                           NULL);
 570                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 571                         return;         /* no masked permission */
 572                 masked = ~lo_avd.allowed & avd->allowed;
 573         }
 574
 575         if (target->bounds) {
 576                 memset(&lo_avd, 0, sizeof(lo_avd));
 577
 578                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 579                 lo_tcontext.type = target->bounds;
 580
 581                 context_struct_compute_av(scontext,
 582                                           &lo_tcontext,
 583                                           tclass,
 584                                           &lo_avd,
 585                                           NULL);
 586                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 587                         return;         /* no masked permission */
 588                 masked = ~lo_avd.allowed & avd->allowed;
 589         }
 590
 591         if (source->bounds && target->bounds) {
 592                 memset(&lo_avd, 0, sizeof(lo_avd));
 593                 /*
 594                  * lo_scontext and lo_tcontext are already
 595                  * set up.
 596                  */
 597
 598                 context_struct_compute_av(&lo_scontext,
 599                                           &lo_tcontext,
 600                                           tclass,
 601                                           &lo_avd,
 602                                           NULL);
 603                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 604                         return;         /* no masked permission */
 605                 masked = ~lo_avd.allowed & avd->allowed;
 606         }
 607
 608         if (masked) {
 609                 /* mask violated permissions */
 610                 avd->allowed &= ~masked;
 611
 612                 /* audit masked permissions */
 613                 security_dump_masked_av(scontext, tcontext,
 614                                         tclass, masked, "bounds");
 615         }
 616 }
 617
 618 /* flag ioctl types that have operation permissions */
 619 void services_compute_operation_type(
 620                 struct operation *ops,
 621                 struct avtab_node *node)
 622 {
 623         u8 type;
 624         unsigned int i;
 625
 626         if (node->key.specified & AVTAB_OPTYPE) {
 627                 /* if allowing one or more complete types */
 628                 for (i = 0; i < ARRAY_SIZE(ops->type); i++)
 629                         ops->type[i] |= node->datum.u.ops->op.perms[i];
 630         } else {
 631                 /* if allowing operations within a type */
 632                 type = node->datum.u.ops->type;
 633                 security_operation_set(ops->type, type);
 634         }
 635
 636         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 637         if (node->key.specified & AVTAB_OPTYPE_ALLOWED ||
 638                         node->key.specified & AVTAB_OPNUM_ALLOWED)
 639                 ops->len = 1;
 640 }
 641
 642 /*
 643  * Compute access vectors and operations ranges based on a context
 644  * structure pair for the permissions in a particular class.
 645  */
 646 static void context_struct_compute_av(struct context *scontext,
 647                                         struct context *tcontext,
 648                                         u16 tclass,
 649                                         struct av_decision *avd,
 650                                         struct operation *ops)
 651 {
 652         struct constraint_node *constraint;
 653         struct role_allow *ra;
 654         struct avtab_key avkey;
 655         struct avtab_node *node;
 656         struct class_datum *tclass_datum;
 657         struct ebitmap *sattr, *tattr;
 658         struct ebitmap_node *snode, *tnode;
 659         unsigned int i, j;
 660
 661         avd->allowed = 0;
 662         avd->auditallow = 0;
 663         avd->auditdeny = 0xffffffff;
 664         if (ops) {
 665                 memset(&ops->type, 0, sizeof(ops->type));
 666                 ops->len = 0;
 667         }
 668
 669         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 670                 if (printk_ratelimit())
 671                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 672                 return;
 673         }
 674
 675         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 676
 677         /*
 678          * If a specific type enforcement rule was defined for
 679          * this permission check, then use it.
 680          */
 681         avkey.target_class = tclass;
 682         avkey.specified = AVTAB_AV | AVTAB_OP;
 683         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 684         BUG_ON(!sattr);
 685         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 686         BUG_ON(!tattr);
 687         ebitmap_for_each_positive_bit(sattr, snode, i) {
 688                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 689                         avkey.source_type = i + 1;
 690                         avkey.target_type = j + 1;
 691                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 692                              node;
 693                              node = avtab_search_node_next(node, avkey.specified)) {
 694                                 if (node->key.specified == AVTAB_ALLOWED)
 695                                         avd->allowed |= node->datum.u.data;
 696                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 697                                         avd->auditallow |= node->datum.u.data;
 698                                 else if (node->key.specified == AVTAB_AUDITDENY)
 699                                         avd->auditdeny &= node->datum.u.data;
 700                                 else if (ops && (node->key.specified & AVTAB_OP))
 701                                         services_compute_operation_type(ops, node);
 702                         }
 703
 704                         /* Check conditional av table for additional permissions */
 705                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd, ops);
 706
 707                 }
 708         }
 709
 710         /*
 711          * Remove any permissions prohibited by a constraint (this includes
 712          * the MLS policy).
 713          */
 714         constraint = tclass_datum->constraints;
 715         while (constraint) {
 716                 if ((constraint->permissions & (avd->allowed)) &&
 717                     !constraint_expr_eval(scontext, tcontext, NULL,
 718                                           constraint->expr)) {
 719                         avd->allowed &= ~(constraint->permissions);
 720                 }
 721                 constraint = constraint->next;
 722         }
 723
 724         /*
 725          * If checking process transition permission and the
 726          * role is changing, then check the (current_role, new_role)
 727          * pair.
 728          */
 729         if (tclass == policydb.process_class &&
 730             (avd->allowed & policydb.process_trans_perms) &&
 731             scontext->role != tcontext->role) {
 732                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 733                         if (scontext->role == ra->role &&
 734                             tcontext->role == ra->new_role)
 735                                 break;
 736                 }
 737                 if (!ra)
 738                         avd->allowed &= ~policydb.process_trans_perms;
 739         }
 740
 741         /*
 742          * If the given source and target types have boundary
 743          * constraint, lazy checks have to mask any violated
 744          * permission and notice it to userspace via audit.
 745          */
 746         type_attribute_bounds_av(scontext, tcontext,
 747                                  tclass, avd);
 748 }
 749
 750 static int security_validtrans_handle_fail(struct context *ocontext,
 751                                            struct context *ncontext,
 752                                            struct context *tcontext,
 753                                            u16 tclass)
 754 {
 755         char *o = NULL, *n = NULL, *t = NULL;
 756         u32 olen, nlen, tlen;
 757
 758         if (context_struct_to_string(ocontext, &o, &olen))
 759                 goto out;
 760         if (context_struct_to_string(ncontext, &n, &nlen))
 761                 goto out;
 762         if (context_struct_to_string(tcontext, &t, &tlen))
 763                 goto out;
 764         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 765                   "security_validate_transition:  denied for"
 766                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 767                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 768 out:
 769         kfree(o);
 770         kfree(n);
 771         kfree(t);
 772
 773         if (!selinux_enforcing)
 774                 return 0;
 775         return -EPERM;
 776 }
 777
 778 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 779                                  u16 orig_tclass)
 780 {
 781         struct context *ocontext;
 782         struct context *ncontext;
 783         struct context *tcontext;
 784         struct class_datum *tclass_datum;
 785         struct constraint_node *constraint;
 786         u16 tclass;
 787         int rc = 0;
 788
 789         if (!ss_initialized)
 790                 return 0;
 791
 792         read_lock(&policy_rwlock);
 793
 794         tclass = unmap_class(orig_tclass);
 795
 796         if (!tclass || tclass > policydb.p_classes.nprim) {
 797                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 798                         __func__, tclass);
 799                 rc = -EINVAL;
 800                 goto out;
 801         }
 802         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 803
 804         ocontext = sidtab_search(&sidtab, oldsid);
 805         if (!ocontext) {
 806                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 807                         __func__, oldsid);
 808                 rc = -EINVAL;
 809                 goto out;
 810         }
 811
 812         ncontext = sidtab_search(&sidtab, newsid);
 813         if (!ncontext) {
 814                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 815                         __func__, newsid);
 816                 rc = -EINVAL;
 817                 goto out;
 818         }
 819
 820         tcontext = sidtab_search(&sidtab, tasksid);
 821         if (!tcontext) {
 822                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 823                         __func__, tasksid);
 824                 rc = -EINVAL;
 825                 goto out;
 826         }
 827
 828         constraint = tclass_datum->validatetrans;
 829         while (constraint) {
 830                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 831                                           constraint->expr)) {
 832                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 833                                                              tcontext, tclass);
 834                         goto out;
 835                 }
 836                 constraint = constraint->next;
 837         }
 838
 839 out:
 840         read_unlock(&policy_rwlock);
 841         return rc;
 842 }
 843
 844 /*
 845  * security_bounded_transition - check whether the given
 846  * transition is directed to bounded, or not.
 847  * It returns 0, if @newsid is bounded by @oldsid.
 848  * Otherwise, it returns error code.
 849  *
 850  * @oldsid : current security identifier
 851  * @newsid : destinated security identifier
 852  */
 853 int security_bounded_transition(u32 old_sid, u32 new_sid)
 854 {
 855         struct context *old_context, *new_context;
 856         struct type_datum *type;
 857         int index;
 858         int rc;
 859
 860         read_lock(&policy_rwlock);
 861
 862         rc = -EINVAL;
 863         old_context = sidtab_search(&sidtab, old_sid);
 864         if (!old_context) {
 865                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 866                        __func__, old_sid);
 867                 goto out;
 868         }
 869
 870         rc = -EINVAL;
 871         new_context = sidtab_search(&sidtab, new_sid);
 872         if (!new_context) {
 873                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 874                        __func__, new_sid);
 875                 goto out;
 876         }
 877
 878         rc = 0;
 879         /* type/domain unchanged */
 880         if (old_context->type == new_context->type)
 881                 goto out;
 882
 883         index = new_context->type;
 884         while (true) {
 885                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 886                                           index - 1);
 887                 BUG_ON(!type);
 888
 889                 /* not bounded anymore */
 890                 rc = -EPERM;
 891                 if (!type->bounds)
 892                         break;
 893
 894                 /* @newsid is bounded by @oldsid */
 895                 rc = 0;
 896                 if (type->bounds == old_context->type)
 897                         break;
 898
 899                 index = type->bounds;
 900         }
 901
 902         if (rc) {
 903                 char *old_name = NULL;
 904                 char *new_name = NULL;
 905                 u32 length;
 906
 907                 if (!context_struct_to_string(old_context,
 908                                               &old_name, &length) &&
 909                     !context_struct_to_string(new_context,
 910                                               &new_name, &length)) {
 911                         audit_log(current->audit_context,
 912                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 913                                   "op=security_bounded_transition "
 914                                   "result=denied "
 915                                   "oldcontext=%s newcontext=%s",
 916                                   old_name, new_name);
 917                 }
 918                 kfree(new_name);
 919                 kfree(old_name);
 920         }
 921 out:
 922         read_unlock(&policy_rwlock);
 923
 924         return rc;
 925 }
 926
 927 static void avd_init(struct av_decision *avd)
 928 {
 929         avd->allowed = 0;
 930         avd->auditallow = 0;
 931         avd->auditdeny = 0xffffffff;
 932         avd->seqno = latest_granting;
 933         avd->flags = 0;
 934 }
 935
 936 void services_compute_operation_num(struct operation_decision *od,
 937                                         struct avtab_node *node)
 938 {
 939         unsigned int i;
 940
 941         if (node->key.specified & AVTAB_OPNUM) {
 942                 if (od->type != node->datum.u.ops->type)
 943                         return;
 944         } else {
 945                 if (!security_operation_test(node->datum.u.ops->op.perms,
 946                                         od->type))
 947                         return;
 948         }
 949
 950         if (node->key.specified == AVTAB_OPTYPE_ALLOWED) {
 951                 od->specified |= OPERATION_ALLOWED;
 952                 memset(od->allowed->perms, 0xff,
 953                                 sizeof(od->allowed->perms));
 954         } else if (node->key.specified == AVTAB_OPTYPE_AUDITALLOW) {
 955                 od->specified |= OPERATION_AUDITALLOW;
 956                 memset(od->auditallow->perms, 0xff,
 957                                 sizeof(od->auditallow->perms));
 958         } else if (node->key.specified == AVTAB_OPTYPE_DONTAUDIT) {
 959                 od->specified |= OPERATION_DONTAUDIT;
 960                 memset(od->dontaudit->perms, 0xff,
 961                                 sizeof(od->dontaudit->perms));
 962         } else if (node->key.specified == AVTAB_OPNUM_ALLOWED) {
 963                 od->specified |= OPERATION_ALLOWED;
 964                 for (i = 0; i < ARRAY_SIZE(od->allowed->perms); i++)
 965                         od->allowed->perms[i] |=
 966                                         node->datum.u.ops->op.perms[i];
 967         } else if (node->key.specified == AVTAB_OPNUM_AUDITALLOW) {
 968                 od->specified |= OPERATION_AUDITALLOW;
 969                 for (i = 0; i < ARRAY_SIZE(od->auditallow->perms); i++)
 970                         od->auditallow->perms[i] |=
 971                                         node->datum.u.ops->op.perms[i];
 972         } else if (node->key.specified == AVTAB_OPNUM_DONTAUDIT) {
 973                 od->specified |= OPERATION_DONTAUDIT;
 974                 for (i = 0; i < ARRAY_SIZE(od->dontaudit->perms); i++)
 975                         od->dontaudit->perms[i] |=
 976                                         node->datum.u.ops->op.perms[i];
 977         } else {
 978                 BUG();
 979         }
 980 }
 981
 982 void security_compute_operation(u32 ssid,
 983                                 u32 tsid,
 984                                 u16 orig_tclass,
 985                                 u8 type,
 986                                 struct operation_decision *od)
 987 {
 988         u16 tclass;
 989         struct context *scontext, *tcontext;
 990         struct avtab_key avkey;
 991         struct avtab_node *node;
 992         struct ebitmap *sattr, *tattr;
 993         struct ebitmap_node *snode, *tnode;
 994         unsigned int i, j;
 995
 996         od->type = type;
 997         od->specified = 0;
 998         memset(od->allowed->perms, 0, sizeof(od->allowed->perms));
 999         memset(od->auditallow->perms, 0, sizeof(od->auditallow->perms));
1000         memset(od->dontaudit->perms, 0, sizeof(od->dontaudit->perms));
1001
1002         read_lock(&policy_rwlock);
1003         if (!ss_initialized)
1004                 goto allow;
1005
1006         scontext = sidtab_search(&sidtab, ssid);
1007         if (!scontext) {
1008                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1009                        __func__, ssid);
1010                 goto out;
1011         }
1012
1013         tcontext = sidtab_search(&sidtab, tsid);
1014         if (!tcontext) {
1015                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1016                        __func__, tsid);
1017                 goto out;
1018         }
1019
1020         tclass = unmap_class(orig_tclass);
1021         if (unlikely(orig_tclass && !tclass)) {
1022                 if (policydb.allow_unknown)
1023                         goto allow;
1024                 goto out;
1025         }
1026
1027
1028         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1029                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1030                 goto out;
1031         }
1032
1033         avkey.target_class = tclass;
1034         avkey.specified = AVTAB_OP;
1035         sattr = flex_array_get(policydb.type_attr_map_array,
1036                                 scontext->type - 1);
1037         BUG_ON(!sattr);
1038         tattr = flex_array_get(policydb.type_attr_map_array,
1039                                 tcontext->type - 1);
1040         BUG_ON(!tattr);
1041         ebitmap_for_each_positive_bit(sattr, snode, i) {
1042                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1043                         avkey.source_type = i + 1;
1044                         avkey.target_type = j + 1;
1045                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1046                              node;
1047                              node = avtab_search_node_next(node, avkey.specified))
1048                                 services_compute_operation_num(od, node);
1049
1050                         cond_compute_operation(&policydb.te_cond_avtab,
1051                                                 &avkey, od);
1052                 }
1053         }
1054 out:
1055         read_unlock(&policy_rwlock);
1056         return;
1057 allow:
1058         memset(od->allowed->perms, 0xff, sizeof(od->allowed->perms));
1059         goto out;
1060 }
1061 /**
1062  * security_compute_av - Compute access vector decisions.
1063  * @ssid: source security identifier
1064  * @tsid: target security identifier
1065  * @tclass: target security class
1066  * @avd: access vector decisions
1067  * @od: operation decisions
1068  *
1069  * Compute a set of access vector decisions based on the
1070  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1071  */
1072 void security_compute_av(u32 ssid,
1073                          u32 tsid,
1074                          u16 orig_tclass,
1075                          struct av_decision *avd,
1076                          struct operation *ops)
1077 {
1078         u16 tclass;
1079         struct context *scontext = NULL, *tcontext = NULL;
1080
1081         read_lock(&policy_rwlock);
1082         avd_init(avd);
1083         ops->len = 0;
1084         if (!ss_initialized)
1085                 goto allow;
1086
1087         scontext = sidtab_search(&sidtab, ssid);
1088         if (!scontext) {
1089                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1090                        __func__, ssid);
1091                 goto out;
1092         }
1093
1094         /* permissive domain? */
1095         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1096                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1097
1098         tcontext = sidtab_search(&sidtab, tsid);
1099         if (!tcontext) {
1100                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1101                        __func__, tsid);
1102                 goto out;
1103         }
1104
1105         tclass = unmap_class(orig_tclass);
1106         if (unlikely(orig_tclass && !tclass)) {
1107                 if (policydb.allow_unknown)
1108                         goto allow;
1109                 goto out;
1110         }
1111         context_struct_compute_av(scontext, tcontext, tclass, avd, ops);
1112         map_decision(orig_tclass, avd, policydb.allow_unknown);
1113 out:
1114         read_unlock(&policy_rwlock);
1115         return;
1116 allow:
1117         avd->allowed = 0xffffffff;
1118         goto out;
1119 }
1120
1121 void security_compute_av_user(u32 ssid,
1122                               u32 tsid,
1123                               u16 tclass,
1124                               struct av_decision *avd)
1125 {
1126         struct context *scontext = NULL, *tcontext = NULL;
1127
1128         read_lock(&policy_rwlock);
1129         avd_init(avd);
1130         if (!ss_initialized)
1131                 goto allow;
1132
1133         scontext = sidtab_search(&sidtab, ssid);
1134         if (!scontext) {
1135                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1136                        __func__, ssid);
1137                 goto out;
1138         }
1139
1140         /* permissive domain? */
1141         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1142                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1143
1144         tcontext = sidtab_search(&sidtab, tsid);
1145         if (!tcontext) {
1146                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1147                        __func__, tsid);
1148                 goto out;
1149         }
1150
1151         if (unlikely(!tclass)) {
1152                 if (policydb.allow_unknown)
1153                         goto allow;
1154                 goto out;
1155         }
1156
1157         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1158  out:
1159         read_unlock(&policy_rwlock);
1160         return;
1161 allow:
1162         avd->allowed = 0xffffffff;
1163         goto out;
1164 }
1165
1166 /*
1167  * Write the security context string representation of
1168  * the context structure `context' into a dynamically
1169  * allocated string of the correct size.  Set `*scontext'
1170  * to point to this string and set `*scontext_len' to
1171  * the length of the string.
1172  */
1173 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1174 {
1175         char *scontextp;
1176
1177         if (scontext)
1178                 *scontext = NULL;
1179         *scontext_len = 0;
1180
1181         if (context->len) {
1182                 *scontext_len = context->len;
1183                 if (scontext) {
1184                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1185                         if (!(*scontext))
1186                                 return -ENOMEM;
1187                 }
1188                 return 0;
1189         }
1190
1191         /* Compute the size of the context. */
1192         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1193         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1194         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1195         *scontext_len += mls_compute_context_len(context);
1196
1197         if (!scontext)
1198                 return 0;
1199
1200         /* Allocate space for the context; caller must free this space. */
1201         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1202         if (!scontextp)
1203                 return -ENOMEM;
1204         *scontext = scontextp;
1205
1206         /*
1207          * Copy the user name, role name and type name into the context.
1208          */
1209         sprintf(scontextp, "%s:%s:%s",
1210                 sym_name(&policydb, SYM_USERS, context->user - 1),
1211                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1212                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1213         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1214                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1215                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1216
1217         mls_sid_to_context(context, &scontextp);
1218
1219         *scontextp = 0;
1220
1221         return 0;
1222 }
1223
1224 #include "initial_sid_to_string.h"
1225
1226 const char *security_get_initial_sid_context(u32 sid)
1227 {
1228         if (unlikely(sid > SECINITSID_NUM))
1229                 return NULL;
1230         return initial_sid_to_string[sid];
1231 }
1232
1233 static int security_sid_to_context_core(u32 sid, char **scontext,
1234                                         u32 *scontext_len, int force)
1235 {
1236         struct context *context;
1237         int rc = 0;
1238
1239         if (scontext)
1240                 *scontext = NULL;
1241         *scontext_len  = 0;
1242
1243         if (!ss_initialized) {
1244                 if (sid <= SECINITSID_NUM) {
1245                         char *scontextp;
1246
1247                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1248                         if (!scontext)
1249                                 goto out;
1250                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1251                         if (!scontextp) {
1252                                 rc = -ENOMEM;
1253                                 goto out;
1254                         }
1255                         strcpy(scontextp, initial_sid_to_string[sid]);
1256                         *scontext = scontextp;
1257                         goto out;
1258                 }
1259                 printk(KERN_ERR "SELinux: %s:  called before initial "
1260                        "load_policy on unknown SID %d\n", __func__, sid);
1261                 rc = -EINVAL;
1262                 goto out;
1263         }
1264         read_lock(&policy_rwlock);
1265         if (force)
1266                 context = sidtab_search_force(&sidtab, sid);
1267         else
1268                 context = sidtab_search(&sidtab, sid);
1269         if (!context) {
1270                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1271                         __func__, sid);
1272                 rc = -EINVAL;
1273                 goto out_unlock;
1274         }
1275         rc = context_struct_to_string(context, scontext, scontext_len);
1276 out_unlock:
1277         read_unlock(&policy_rwlock);
1278 out:
1279         return rc;
1280
1281 }
1282
1283 /**
1284  * security_sid_to_context - Obtain a context for a given SID.
1285  * @sid: security identifier, SID
1286  * @scontext: security context
1287  * @scontext_len: length in bytes
1288  *
1289  * Write the string representation of the context associated with @sid
1290  * into a dynamically allocated string of the correct size.  Set @scontext
1291  * to point to this string and set @scontext_len to the length of the string.
1292  */
1293 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1294 {
1295         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1296 }
1297
1298 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1299 {
1300         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1301 }
1302
1303 /*
1304  * Caveat:  Mutates scontext.
1305  */
1306 static int string_to_context_struct(struct policydb *pol,
1307                                     struct sidtab *sidtabp,
1308                                     char *scontext,
1309                                     u32 scontext_len,
1310                                     struct context *ctx,
1311                                     u32 def_sid)
1312 {
1313         struct role_datum *role;
1314         struct type_datum *typdatum;
1315         struct user_datum *usrdatum;
1316         char *scontextp, *p, oldc;
1317         int rc = 0;
1318
1319         context_init(ctx);
1320
1321         /* Parse the security context. */
1322
1323         rc = -EINVAL;
1324         scontextp = (char *) scontext;
1325
1326         /* Extract the user. */
1327         p = scontextp;
1328         while (*p && *p != ':')
1329                 p++;
1330
1331         if (*p == 0)
1332                 goto out;
1333
1334         *p++ = 0;
1335
1336         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1337         if (!usrdatum)
1338                 goto out;
1339
1340         ctx->user = usrdatum->value;
1341
1342         /* Extract role. */
1343         scontextp = p;
1344         while (*p && *p != ':')
1345                 p++;
1346
1347         if (*p == 0)
1348                 goto out;
1349
1350         *p++ = 0;
1351
1352         role = hashtab_search(pol->p_roles.table, scontextp);
1353         if (!role)
1354                 goto out;
1355         ctx->role = role->value;
1356
1357         /* Extract type. */
1358         scontextp = p;
1359         while (*p && *p != ':')
1360                 p++;
1361         oldc = *p;
1362         *p++ = 0;
1363
1364         typdatum = hashtab_search(pol->p_types.table, scontextp);
1365         if (!typdatum || typdatum->attribute)
1366                 goto out;
1367
1368         ctx->type = typdatum->value;
1369
1370         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1371         if (rc)
1372                 goto out;
1373
1374         rc = -EINVAL;
1375         if ((p - scontext) < scontext_len)
1376                 goto out;
1377
1378         /* Check the validity of the new context. */
1379         if (!policydb_context_isvalid(pol, ctx))
1380                 goto out;
1381         rc = 0;
1382 out:
1383         if (rc)
1384                 context_destroy(ctx);
1385         return rc;
1386 }
1387
1388 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1389                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1390                                         int force)
1391 {
1392         char *scontext2, *str = NULL;
1393         struct context context;
1394         int rc = 0;
1395
1396         /* An empty security context is never valid. */
1397         if (!scontext_len)
1398                 return -EINVAL;
1399
1400         if (!ss_initialized) {
1401                 int i;
1402
1403                 for (i = 1; i < SECINITSID_NUM; i++) {
1404                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1405                                 *sid = i;
1406                                 return 0;
1407                         }
1408                 }
1409                 *sid = SECINITSID_KERNEL;
1410                 return 0;
1411         }
1412         *sid = SECSID_NULL;
1413
1414         /* Copy the string so that we can modify the copy as we parse it. */
1415         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1416         if (!scontext2)
1417                 return -ENOMEM;
1418         memcpy(scontext2, scontext, scontext_len);
1419         scontext2[scontext_len] = 0;
1420
1421         if (force) {
1422                 /* Save another copy for storing in uninterpreted form */
1423                 rc = -ENOMEM;
1424                 str = kstrdup(scontext2, gfp_flags);
1425                 if (!str)
1426                         goto out;
1427         }
1428
1429         read_lock(&policy_rwlock);
1430         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1431                                       scontext_len, &context, def_sid);
1432         if (rc == -EINVAL && force) {
1433                 context.str = str;
1434                 context.len = scontext_len;
1435                 str = NULL;
1436         } else if (rc)
1437                 goto out_unlock;
1438         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1439         context_destroy(&context);
1440 out_unlock:
1441         read_unlock(&policy_rwlock);
1442 out:
1443         kfree(scontext2);
1444         kfree(str);
1445         return rc;
1446 }
1447
1448 /**
1449  * security_context_to_sid - Obtain a SID for a given security context.
1450  * @scontext: security context
1451  * @scontext_len: length in bytes
1452  * @sid: security identifier, SID
1453  *
1454  * Obtains a SID associated with the security context that
1455  * has the string representation specified by @scontext.
1456  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1457  * memory is available, or 0 on success.
1458  */
1459 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1460 {
1461         return security_context_to_sid_core(scontext, scontext_len,
1462                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1463 }
1464
1465 /**
1466  * security_context_to_sid_default - Obtain a SID for a given security context,
1467  * falling back to specified default if needed.
1468  *
1469  * @scontext: security context
1470  * @scontext_len: length in bytes
1471  * @sid: security identifier, SID
1472  * @def_sid: default SID to assign on error
1473  *
1474  * Obtains a SID associated with the security context that
1475  * has the string representation specified by @scontext.
1476  * The default SID is passed to the MLS layer to be used to allow
1477  * kernel labeling of the MLS field if the MLS field is not present
1478  * (for upgrading to MLS without full relabel).
1479  * Implicitly forces adding of the context even if it cannot be mapped yet.
1480  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1481  * memory is available, or 0 on success.
1482  */
1483 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1484                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1485 {
1486         return security_context_to_sid_core(scontext, scontext_len,
1487                                             sid, def_sid, gfp_flags, 1);
1488 }
1489
1490 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1491                                   u32 *sid)
1492 {
1493         return security_context_to_sid_core(scontext, scontext_len,
1494                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1495 }
1496
1497 static int compute_sid_handle_invalid_context(
1498         struct context *scontext,
1499         struct context *tcontext,
1500         u16 tclass,
1501         struct context *newcontext)
1502 {
1503         char *s = NULL, *t = NULL, *n = NULL;
1504         u32 slen, tlen, nlen;
1505
1506         if (context_struct_to_string(scontext, &s, &slen))
1507                 goto out;
1508         if (context_struct_to_string(tcontext, &t, &tlen))
1509                 goto out;
1510         if (context_struct_to_string(newcontext, &n, &nlen))
1511                 goto out;
1512         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1513                   "security_compute_sid:  invalid context %s"
1514                   " for scontext=%s"
1515                   " tcontext=%s"
1516                   " tclass=%s",
1517                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1518 out:
1519         kfree(s);
1520         kfree(t);
1521         kfree(n);
1522         if (!selinux_enforcing)
1523                 return 0;
1524         return -EACCES;
1525 }
1526
1527 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1528                                   u32 stype, u32 ttype, u16 tclass,
1529                                   const char *objname)
1530 {
1531         struct filename_trans ft;
1532         struct filename_trans_datum *otype;
1533
1534         /*
1535          * Most filename trans rules are going to live in specific directories
1536          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1537          * if the ttype does not contain any rules.
1538          */
1539         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1540                 return;
1541
1542         ft.stype = stype;
1543         ft.ttype = ttype;
1544         ft.tclass = tclass;
1545         ft.name = objname;
1546
1547         otype = hashtab_search(p->filename_trans, &ft);
1548         if (otype)
1549                 newcontext->type = otype->otype;
1550 }
1551
1552 static int security_compute_sid(u32 ssid,
1553                                 u32 tsid,
1554                                 u16 orig_tclass,
1555                                 u32 specified,
1556                                 const char *objname,
1557                                 u32 *out_sid,
1558                                 bool kern)
1559 {
1560         struct class_datum *cladatum = NULL;
1561         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1562         struct role_trans *roletr = NULL;
1563         struct avtab_key avkey;
1564         struct avtab_datum *avdatum;
1565         struct avtab_node *node;
1566         u16 tclass;
1567         int rc = 0;
1568         bool sock;
1569
1570         if (!ss_initialized) {
1571                 switch (orig_tclass) {
1572                 case SECCLASS_PROCESS: /* kernel value */
1573                         *out_sid = ssid;
1574                         break;
1575                 default:
1576                         *out_sid = tsid;
1577                         break;
1578                 }
1579                 goto out;
1580         }
1581
1582         context_init(&newcontext);
1583
1584         read_lock(&policy_rwlock);
1585
1586         if (kern) {
1587                 tclass = unmap_class(orig_tclass);
1588                 sock = security_is_socket_class(orig_tclass);
1589         } else {
1590                 tclass = orig_tclass;
1591                 sock = security_is_socket_class(map_class(tclass));
1592         }
1593
1594         scontext = sidtab_search(&sidtab, ssid);
1595         if (!scontext) {
1596                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1597                        __func__, ssid);
1598                 rc = -EINVAL;
1599                 goto out_unlock;
1600         }
1601         tcontext = sidtab_search(&sidtab, tsid);
1602         if (!tcontext) {
1603                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1604                        __func__, tsid);
1605                 rc = -EINVAL;
1606                 goto out_unlock;
1607         }
1608
1609         if (tclass && tclass <= policydb.p_classes.nprim)
1610                 cladatum = policydb.class_val_to_struct[tclass - 1];
1611
1612         /* Set the user identity. */
1613         switch (specified) {
1614         case AVTAB_TRANSITION:
1615         case AVTAB_CHANGE:
1616                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1617                         newcontext.user = tcontext->user;
1618                 } else {
1619                         /* notice this gets both DEFAULT_SOURCE and unset */
1620                         /* Use the process user identity. */
1621                         newcontext.user = scontext->user;
1622                 }
1623                 break;
1624         case AVTAB_MEMBER:
1625                 /* Use the related object owner. */
1626                 newcontext.user = tcontext->user;
1627                 break;
1628         }
1629
1630         /* Set the role to default values. */
1631         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1632                 newcontext.role = scontext->role;
1633         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1634                 newcontext.role = tcontext->role;
1635         } else {
1636                 if ((tclass == policydb.process_class) || (sock == true))
1637                         newcontext.role = scontext->role;
1638                 else
1639                         newcontext.role = OBJECT_R_VAL;
1640         }
1641
1642         /* Set the type to default values. */
1643         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1644                 newcontext.type = scontext->type;
1645         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1646                 newcontext.type = tcontext->type;
1647         } else {
1648                 if ((tclass == policydb.process_class) || (sock == true)) {
1649                         /* Use the type of process. */
1650                         newcontext.type = scontext->type;
1651                 } else {
1652                         /* Use the type of the related object. */
1653                         newcontext.type = tcontext->type;
1654                 }
1655         }
1656
1657         /* Look for a type transition/member/change rule. */
1658         avkey.source_type = scontext->type;
1659         avkey.target_type = tcontext->type;
1660         avkey.target_class = tclass;
1661         avkey.specified = specified;
1662         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1663
1664         /* If no permanent rule, also check for enabled conditional rules */
1665         if (!avdatum) {
1666                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1667                 for (; node; node = avtab_search_node_next(node, specified)) {
1668                         if (node->key.specified & AVTAB_ENABLED) {
1669                                 avdatum = &node->datum;
1670                                 break;
1671                         }
1672                 }
1673         }
1674
1675         if (avdatum) {
1676                 /* Use the type from the type transition/member/change rule. */
1677                 newcontext.type = avdatum->u.data;
1678         }
1679
1680         /* if we have a objname this is a file trans check so check those rules */
1681         if (objname)
1682                 filename_compute_type(&policydb, &newcontext, scontext->type,
1683                                       tcontext->type, tclass, objname);
1684
1685         /* Check for class-specific changes. */
1686         if (specified & AVTAB_TRANSITION) {
1687                 /* Look for a role transition rule. */
1688                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1689                         if ((roletr->role == scontext->role) &&
1690                             (roletr->type == tcontext->type) &&
1691                             (roletr->tclass == tclass)) {
1692                                 /* Use the role transition rule. */
1693                                 newcontext.role = roletr->new_role;
1694                                 break;
1695                         }
1696                 }
1697         }
1698
1699         /* Set the MLS attributes.
1700            This is done last because it may allocate memory. */
1701         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1702                              &newcontext, sock);
1703         if (rc)
1704                 goto out_unlock;
1705
1706         /* Check the validity of the context. */
1707         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1708                 rc = compute_sid_handle_invalid_context(scontext,
1709                                                         tcontext,
1710                                                         tclass,
1711                                                         &newcontext);
1712                 if (rc)
1713                         goto out_unlock;
1714         }
1715         /* Obtain the sid for the context. */
1716         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1717 out_unlock:
1718         read_unlock(&policy_rwlock);
1719         context_destroy(&newcontext);
1720 out:
1721         return rc;
1722 }
1723
1724 /**
1725  * security_transition_sid - Compute the SID for a new subject/object.
1726  * @ssid: source security identifier
1727  * @tsid: target security identifier
1728  * @tclass: target security class
1729  * @out_sid: security identifier for new subject/object
1730  *
1731  * Compute a SID to use for labeling a new subject or object in the
1732  * class @tclass based on a SID pair (@ssid, @tsid).
1733  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1734  * if insufficient memory is available, or %0 if the new SID was
1735  * computed successfully.
1736  */
1737 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1738                             const struct qstr *qstr, u32 *out_sid)
1739 {
1740         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1741                                     qstr ? qstr->name : NULL, out_sid, true);
1742 }
1743
1744 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1745                                  const char *objname, u32 *out_sid)
1746 {
1747         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1748                                     objname, out_sid, false);
1749 }
1750
1751 /**
1752  * security_member_sid - Compute the SID for member selection.
1753  * @ssid: source security identifier
1754  * @tsid: target security identifier
1755  * @tclass: target security class
1756  * @out_sid: security identifier for selected member
1757  *
1758  * Compute a SID to use when selecting a member of a polyinstantiated
1759  * object of class @tclass based on a SID pair (@ssid, @tsid).
1760  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1761  * if insufficient memory is available, or %0 if the SID was
1762  * computed successfully.
1763  */
1764 int security_member_sid(u32 ssid,
1765                         u32 tsid,
1766                         u16 tclass,
1767                         u32 *out_sid)
1768 {
1769         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1770                                     out_sid, false);
1771 }
1772
1773 /**
1774  * security_change_sid - Compute the SID for object relabeling.
1775  * @ssid: source security identifier
1776  * @tsid: target security identifier
1777  * @tclass: target security class
1778  * @out_sid: security identifier for selected member
1779  *
1780  * Compute a SID to use for relabeling an object of class @tclass
1781  * based on a SID pair (@ssid, @tsid).
1782  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1783  * if insufficient memory is available, or %0 if the SID was
1784  * computed successfully.
1785  */
1786 int security_change_sid(u32 ssid,
1787                         u32 tsid,
1788                         u16 tclass,
1789                         u32 *out_sid)
1790 {
1791         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1792                                     out_sid, false);
1793 }
1794
1795 /* Clone the SID into the new SID table. */
1796 static int clone_sid(u32 sid,
1797                      struct context *context,
1798                      void *arg)
1799 {
1800         struct sidtab *s = arg;
1801
1802         if (sid > SECINITSID_NUM)
1803                 return sidtab_insert(s, sid, context);
1804         else
1805                 return 0;
1806 }
1807
1808 static inline int convert_context_handle_invalid_context(struct context *context)
1809 {
1810         char *s;
1811         u32 len;
1812
1813         if (selinux_enforcing)
1814                 return -EINVAL;
1815
1816         if (!context_struct_to_string(context, &s, &len)) {
1817                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1818                 kfree(s);
1819         }
1820         return 0;
1821 }
1822
1823 struct convert_context_args {
1824         struct policydb *oldp;
1825         struct policydb *newp;
1826 };
1827
1828 /*
1829  * Convert the values in the security context
1830  * structure `c' from the values specified
1831  * in the policy `p->oldp' to the values specified
1832  * in the policy `p->newp'.  Verify that the
1833  * context is valid under the new policy.
1834  */
1835 static int convert_context(u32 key,
1836                            struct context *c,
1837                            void *p)
1838 {
1839         struct convert_context_args *args;
1840         struct context oldc;
1841         struct ocontext *oc;
1842         struct mls_range *range;
1843         struct role_datum *role;
1844         struct type_datum *typdatum;
1845         struct user_datum *usrdatum;
1846         char *s;
1847         u32 len;
1848         int rc = 0;
1849
1850         if (key <= SECINITSID_NUM)
1851                 goto out;
1852
1853         args = p;
1854
1855         if (c->str) {
1856                 struct context ctx;
1857
1858                 rc = -ENOMEM;
1859                 s = kstrdup(c->str, GFP_KERNEL);
1860                 if (!s)
1861                         goto out;
1862
1863                 rc = string_to_context_struct(args->newp, NULL, s,
1864                                               c->len, &ctx, SECSID_NULL);
1865                 kfree(s);
1866                 if (!rc) {
1867                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1868                                c->str);
1869                         /* Replace string with mapped representation. */
1870                         kfree(c->str);
1871                         memcpy(c, &ctx, sizeof(*c));
1872                         goto out;
1873                 } else if (rc == -EINVAL) {
1874                         /* Retain string representation for later mapping. */
1875                         rc = 0;
1876                         goto out;
1877                 } else {
1878                         /* Other error condition, e.g. ENOMEM. */
1879                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1880                                c->str, -rc);
1881                         goto out;
1882                 }
1883         }
1884
1885         rc = context_cpy(&oldc, c);
1886         if (rc)
1887                 goto out;
1888
1889         /* Convert the user. */
1890         rc = -EINVAL;
1891         usrdatum = hashtab_search(args->newp->p_users.table,
1892                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1893         if (!usrdatum)
1894                 goto bad;
1895         c->user = usrdatum->value;
1896
1897         /* Convert the role. */
1898         rc = -EINVAL;
1899         role = hashtab_search(args->newp->p_roles.table,
1900                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1901         if (!role)
1902                 goto bad;
1903         c->role = role->value;
1904
1905         /* Convert the type. */
1906         rc = -EINVAL;
1907         typdatum = hashtab_search(args->newp->p_types.table,
1908                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1909         if (!typdatum)
1910                 goto bad;
1911         c->type = typdatum->value;
1912
1913         /* Convert the MLS fields if dealing with MLS policies */
1914         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1915                 rc = mls_convert_context(args->oldp, args->newp, c);
1916                 if (rc)
1917                         goto bad;
1918         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1919                 /*
1920                  * Switching between MLS and non-MLS policy:
1921                  * free any storage used by the MLS fields in the
1922                  * context for all existing entries in the sidtab.
1923                  */
1924                 mls_context_destroy(c);
1925         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1926                 /*
1927                  * Switching between non-MLS and MLS policy:
1928                  * ensure that the MLS fields of the context for all
1929                  * existing entries in the sidtab are filled in with a
1930                  * suitable default value, likely taken from one of the
1931                  * initial SIDs.
1932                  */
1933                 oc = args->newp->ocontexts[OCON_ISID];
1934                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1935                         oc = oc->next;
1936                 rc = -EINVAL;
1937                 if (!oc) {
1938                         printk(KERN_ERR "SELinux:  unable to look up"
1939                                 " the initial SIDs list\n");
1940                         goto bad;
1941                 }
1942                 range = &oc->context[0].range;
1943                 rc = mls_range_set(c, range);
1944                 if (rc)
1945                         goto bad;
1946         }
1947
1948         /* Check the validity of the new context. */
1949         if (!policydb_context_isvalid(args->newp, c)) {
1950                 rc = convert_context_handle_invalid_context(&oldc);
1951                 if (rc)
1952                         goto bad;
1953         }
1954
1955         context_destroy(&oldc);
1956
1957         rc = 0;
1958 out:
1959         return rc;
1960 bad:
1961         /* Map old representation to string and save it. */
1962         rc = context_struct_to_string(&oldc, &s, &len);
1963         if (rc)
1964                 return rc;
1965         context_destroy(&oldc);
1966         context_destroy(c);
1967         c->str = s;
1968         c->len = len;
1969         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1970                c->str);
1971         rc = 0;
1972         goto out;
1973 }
1974
1975 static void security_load_policycaps(void)
1976 {
1977         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1978                                                   POLICYDB_CAPABILITY_NETPEER);
1979         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1980                                                   POLICYDB_CAPABILITY_OPENPERM);
1981 }
1982
1983 static int security_preserve_bools(struct policydb *p);
1984
1985 /**
1986  * security_load_policy - Load a security policy configuration.
1987  * @data: binary policy data
1988  * @len: length of data in bytes
1989  *
1990  * Load a new set of security policy configuration data,
1991  * validate it and convert the SID table as necessary.
1992  * This function will flush the access vector cache after
1993  * loading the new policy.
1994  */
1995 int security_load_policy(void *data, size_t len)
1996 {
1997         struct policydb oldpolicydb, newpolicydb;
1998         struct sidtab oldsidtab, newsidtab;
1999         struct selinux_mapping *oldmap, *map = NULL;
2000         struct convert_context_args args;
2001         u32 seqno;
2002         u16 map_size;
2003         int rc = 0;
2004         struct policy_file file = { data, len }, *fp = &file;
2005
2006         if (!ss_initialized) {
2007                 avtab_cache_init();
2008                 rc = policydb_read(&policydb, fp);
2009                 if (rc) {
2010                         avtab_cache_destroy();
2011                         return rc;
2012                 }
2013
2014                 policydb.len = len;
2015                 rc = selinux_set_mapping(&policydb, secclass_map,
2016                                          &current_mapping,
2017                                          &current_mapping_size);
2018                 if (rc) {
2019                         policydb_destroy(&policydb);
2020                         avtab_cache_destroy();
2021                         return rc;
2022                 }
2023
2024                 rc = policydb_load_isids(&policydb, &sidtab);
2025                 if (rc) {
2026                         policydb_destroy(&policydb);
2027                         avtab_cache_destroy();
2028                         return rc;
2029                 }
2030
2031                 security_load_policycaps();
2032                 ss_initialized = 1;
2033                 seqno = ++latest_granting;
2034                 selinux_complete_init();
2035                 avc_ss_reset(seqno);
2036                 selnl_notify_policyload(seqno);
2037                 selinux_status_update_policyload(seqno);
2038                 selinux_netlbl_cache_invalidate();
2039                 selinux_xfrm_notify_policyload();
2040                 return 0;
2041         }
2042
2043 #if 0
2044         sidtab_hash_eval(&sidtab, "sids");
2045 #endif
2046
2047         rc = policydb_read(&newpolicydb, fp);
2048         if (rc)
2049                 return rc;
2050
2051         newpolicydb.len = len;
2052         /* If switching between different policy types, log MLS status */
2053         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
2054                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2055         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
2056                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2057
2058         rc = policydb_load_isids(&newpolicydb, &newsidtab);
2059         if (rc) {
2060                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2061                 policydb_destroy(&newpolicydb);
2062                 return rc;
2063         }
2064
2065         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
2066         if (rc)
2067                 goto err;
2068
2069         rc = security_preserve_bools(&newpolicydb);
2070         if (rc) {
2071                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2072                 goto err;
2073         }
2074
2075         /* Clone the SID table. */
2076         sidtab_shutdown(&sidtab);
2077
2078         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2079         if (rc)
2080                 goto err;
2081
2082         /*
2083          * Convert the internal representations of contexts
2084          * in the new SID table.
2085          */
2086         args.oldp = &policydb;
2087         args.newp = &newpolicydb;
2088         rc = sidtab_map(&newsidtab, convert_context, &args);
2089         if (rc) {
2090                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2091                         " representation of contexts in the new SID"
2092                         " table\n");
2093                 goto err;
2094         }
2095
2096         /* Save the old policydb and SID table to free later. */
2097         memcpy(&oldpolicydb, &policydb, sizeof policydb);
2098         sidtab_set(&oldsidtab, &sidtab);
2099
2100         /* Install the new policydb and SID table. */
2101         write_lock_irq(&policy_rwlock);
2102         memcpy(&policydb, &newpolicydb, sizeof policydb);
2103         sidtab_set(&sidtab, &newsidtab);
2104         security_load_policycaps();
2105         oldmap = current_mapping;
2106         current_mapping = map;
2107         current_mapping_size = map_size;
2108         seqno = ++latest_granting;
2109         write_unlock_irq(&policy_rwlock);
2110
2111         /* Free the old policydb and SID table. */
2112         policydb_destroy(&oldpolicydb);
2113         sidtab_destroy(&oldsidtab);
2114         kfree(oldmap);
2115
2116         avc_ss_reset(seqno);
2117         selnl_notify_policyload(seqno);
2118         selinux_status_update_policyload(seqno);
2119         selinux_netlbl_cache_invalidate();
2120         selinux_xfrm_notify_policyload();
2121
2122         return 0;
2123
2124 err:
2125         kfree(map);
2126         sidtab_destroy(&newsidtab);
2127         policydb_destroy(&newpolicydb);
2128         return rc;
2129
2130 }
2131
2132 size_t security_policydb_len(void)
2133 {
2134         size_t len;
2135
2136         read_lock(&policy_rwlock);
2137         len = policydb.len;
2138         read_unlock(&policy_rwlock);
2139
2140         return len;
2141 }
2142
2143 /**
2144  * security_port_sid - Obtain the SID for a port.
2145  * @protocol: protocol number
2146  * @port: port number
2147  * @out_sid: security identifier
2148  */
2149 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2150 {
2151         struct ocontext *c;
2152         int rc = 0;
2153
2154         read_lock(&policy_rwlock);
2155
2156         c = policydb.ocontexts[OCON_PORT];
2157         while (c) {
2158                 if (c->u.port.protocol == protocol &&
2159                     c->u.port.low_port <= port &&
2160                     c->u.port.high_port >= port)
2161                         break;
2162                 c = c->next;
2163         }
2164
2165         if (c) {
2166                 if (!c->sid[0]) {
2167                         rc = sidtab_context_to_sid(&sidtab,
2168                                                    &c->context[0],
2169                                                    &c->sid[0]);
2170                         if (rc)
2171                                 goto out;
2172                 }
2173                 *out_sid = c->sid[0];
2174         } else {
2175                 *out_sid = SECINITSID_PORT;
2176         }
2177
2178 out:
2179         read_unlock(&policy_rwlock);
2180         return rc;
2181 }
2182
2183 /**
2184  * security_netif_sid - Obtain the SID for a network interface.
2185  * @name: interface name
2186  * @if_sid: interface SID
2187  */
2188 int security_netif_sid(char *name, u32 *if_sid)
2189 {
2190         int rc = 0;
2191         struct ocontext *c;
2192
2193         read_lock(&policy_rwlock);
2194
2195         c = policydb.ocontexts[OCON_NETIF];
2196         while (c) {
2197                 if (strcmp(name, c->u.name) == 0)
2198                         break;
2199                 c = c->next;
2200         }
2201
2202         if (c) {
2203                 if (!c->sid[0] || !c->sid[1]) {
2204                         rc = sidtab_context_to_sid(&sidtab,
2205                                                   &c->context[0],
2206                                                   &c->sid[0]);
2207                         if (rc)
2208                                 goto out;
2209                         rc = sidtab_context_to_sid(&sidtab,
2210                                                    &c->context[1],
2211                                                    &c->sid[1]);
2212                         if (rc)
2213                                 goto out;
2214                 }
2215                 *if_sid = c->sid[0];
2216         } else
2217                 *if_sid = SECINITSID_NETIF;
2218
2219 out:
2220         read_unlock(&policy_rwlock);
2221         return rc;
2222 }
2223
2224 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2225 {
2226         int i, fail = 0;
2227
2228         for (i = 0; i < 4; i++)
2229                 if (addr[i] != (input[i] & mask[i])) {
2230                         fail = 1;
2231                         break;
2232                 }
2233
2234         return !fail;
2235 }
2236
2237 /**
2238  * security_node_sid - Obtain the SID for a node (host).
2239  * @domain: communication domain aka address family
2240  * @addrp: address
2241  * @addrlen: address length in bytes
2242  * @out_sid: security identifier
2243  */
2244 int security_node_sid(u16 domain,
2245                       void *addrp,
2246                       u32 addrlen,
2247                       u32 *out_sid)
2248 {
2249         int rc;
2250         struct ocontext *c;
2251
2252         read_lock(&policy_rwlock);
2253
2254         switch (domain) {
2255         case AF_INET: {
2256                 u32 addr;
2257
2258                 rc = -EINVAL;
2259                 if (addrlen != sizeof(u32))
2260                         goto out;
2261
2262                 addr = *((u32 *)addrp);
2263
2264                 c = policydb.ocontexts[OCON_NODE];
2265                 while (c) {
2266                         if (c->u.node.addr == (addr & c->u.node.mask))
2267                                 break;
2268                         c = c->next;
2269                 }
2270                 break;
2271         }
2272
2273         case AF_INET6:
2274                 rc = -EINVAL;
2275                 if (addrlen != sizeof(u64) * 2)
2276                         goto out;
2277                 c = policydb.ocontexts[OCON_NODE6];
2278                 while (c) {
2279                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2280                                                 c->u.node6.mask))
2281                                 break;
2282                         c = c->next;
2283                 }
2284                 break;
2285
2286         default:
2287                 rc = 0;
2288                 *out_sid = SECINITSID_NODE;
2289                 goto out;
2290         }
2291
2292         if (c) {
2293                 if (!c->sid[0]) {
2294                         rc = sidtab_context_to_sid(&sidtab,
2295                                                    &c->context[0],
2296                                                    &c->sid[0]);
2297                         if (rc)
2298                                 goto out;
2299                 }
2300                 *out_sid = c->sid[0];
2301         } else {
2302                 *out_sid = SECINITSID_NODE;
2303         }
2304
2305         rc = 0;
2306 out:
2307         read_unlock(&policy_rwlock);
2308         return rc;
2309 }
2310
2311 #define SIDS_NEL 25
2312
2313 /**
2314  * security_get_user_sids - Obtain reachable SIDs for a user.
2315  * @fromsid: starting SID
2316  * @username: username
2317  * @sids: array of reachable SIDs for user
2318  * @nel: number of elements in @sids
2319  *
2320  * Generate the set of SIDs for legal security contexts
2321  * for a given user that can be reached by @fromsid.
2322  * Set *@sids to point to a dynamically allocated
2323  * array containing the set of SIDs.  Set *@nel to the
2324  * number of elements in the array.
2325  */
2326
2327 int security_get_user_sids(u32 fromsid,
2328                            char *username,
2329                            u32 **sids,
2330                            u32 *nel)
2331 {
2332         struct context *fromcon, usercon;
2333         u32 *mysids = NULL, *mysids2, sid;
2334         u32 mynel = 0, maxnel = SIDS_NEL;
2335         struct user_datum *user;
2336         struct role_datum *role;
2337         struct ebitmap_node *rnode, *tnode;
2338         int rc = 0, i, j;
2339
2340         *sids = NULL;
2341         *nel = 0;
2342
2343         if (!ss_initialized)
2344                 goto out;
2345
2346         read_lock(&policy_rwlock);
2347
2348         context_init(&usercon);
2349
2350         rc = -EINVAL;
2351         fromcon = sidtab_search(&sidtab, fromsid);
2352         if (!fromcon)
2353                 goto out_unlock;
2354
2355         rc = -EINVAL;
2356         user = hashtab_search(policydb.p_users.table, username);
2357         if (!user)
2358                 goto out_unlock;
2359
2360         usercon.user = user->value;
2361
2362         rc = -ENOMEM;
2363         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2364         if (!mysids)
2365                 goto out_unlock;
2366
2367         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2368                 role = policydb.role_val_to_struct[i];
2369                 usercon.role = i + 1;
2370                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2371                         usercon.type = j + 1;
2372
2373                         if (mls_setup_user_range(fromcon, user, &usercon))
2374                                 continue;
2375
2376                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2377                         if (rc)
2378                                 goto out_unlock;
2379                         if (mynel < maxnel) {
2380                                 mysids[mynel++] = sid;
2381                         } else {
2382                                 rc = -ENOMEM;
2383                                 maxnel += SIDS_NEL;
2384                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2385                                 if (!mysids2)
2386                                         goto out_unlock;
2387                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2388                                 kfree(mysids);
2389                                 mysids = mysids2;
2390                                 mysids[mynel++] = sid;
2391                         }
2392                 }
2393         }
2394         rc = 0;
2395 out_unlock:
2396         read_unlock(&policy_rwlock);
2397         if (rc || !mynel) {
2398                 kfree(mysids);
2399                 goto out;
2400         }
2401
2402         rc = -ENOMEM;
2403         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2404         if (!mysids2) {
2405                 kfree(mysids);
2406                 goto out;
2407         }
2408         for (i = 0, j = 0; i < mynel; i++) {
2409                 struct av_decision dummy_avd;
2410                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2411                                           SECCLASS_PROCESS, /* kernel value */
2412                                           PROCESS__TRANSITION, AVC_STRICT,
2413                                           &dummy_avd);
2414                 if (!rc)
2415                         mysids2[j++] = mysids[i];
2416                 cond_resched();
2417         }
2418         rc = 0;
2419         kfree(mysids);
2420         *sids = mysids2;
2421         *nel = j;
2422 out:
2423         return rc;
2424 }
2425
2426 /**
2427  * security_genfs_sid - Obtain a SID for a file in a filesystem
2428  * @fstype: filesystem type
2429  * @path: path from root of mount
2430  * @sclass: file security class
2431  * @sid: SID for path
2432  *
2433  * Obtain a SID to use for a file in a filesystem that
2434  * cannot support xattr or use a fixed labeling behavior like
2435  * transition SIDs or task SIDs.
2436  */
2437 int security_genfs_sid(const char *fstype,
2438                        char *path,
2439                        u16 orig_sclass,
2440                        u32 *sid)
2441 {
2442         int len;
2443         u16 sclass;
2444         struct genfs *genfs;
2445         struct ocontext *c;
2446         int rc, cmp = 0;
2447
2448         while (path[0] == '/' && path[1] == '/')
2449                 path++;
2450
2451         read_lock(&policy_rwlock);
2452
2453         sclass = unmap_class(orig_sclass);
2454         *sid = SECINITSID_UNLABELED;
2455
2456         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2457                 cmp = strcmp(fstype, genfs->fstype);
2458                 if (cmp <= 0)
2459                         break;
2460         }
2461
2462         rc = -ENOENT;
2463         if (!genfs || cmp)
2464                 goto out;
2465
2466         for (c = genfs->head; c; c = c->next) {
2467                 len = strlen(c->u.name);
2468                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2469                     (strncmp(c->u.name, path, len) == 0))
2470                         break;
2471         }
2472
2473         rc = -ENOENT;
2474         if (!c)
2475                 goto out;
2476
2477         if (!c->sid[0]) {
2478                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2479                 if (rc)
2480                         goto out;
2481         }
2482
2483         *sid = c->sid[0];
2484         rc = 0;
2485 out:
2486         read_unlock(&policy_rwlock);
2487         return rc;
2488 }
2489
2490 /**
2491  * security_fs_use - Determine how to handle labeling for a filesystem.
2492  * @fstype: filesystem type
2493  * @behavior: labeling behavior
2494  * @sid: SID for filesystem (superblock)
2495  */
2496 int security_fs_use(
2497         const char *fstype,
2498         unsigned int *behavior,
2499         u32 *sid)
2500 {
2501         int rc = 0;
2502         struct ocontext *c;
2503
2504         read_lock(&policy_rwlock);
2505
2506         c = policydb.ocontexts[OCON_FSUSE];
2507         while (c) {
2508                 if (strcmp(fstype, c->u.name) == 0)
2509                         break;
2510                 c = c->next;
2511         }
2512
2513         if (c) {
2514                 *behavior = c->v.behavior;
2515                 if (!c->sid[0]) {
2516                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2517                                                    &c->sid[0]);
2518                         if (rc)
2519                                 goto out;
2520                 }
2521                 *sid = c->sid[0];
2522         } else {
2523                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2524                 if (rc) {
2525                         *behavior = SECURITY_FS_USE_NONE;
2526                         rc = 0;
2527                 } else {
2528                         *behavior = SECURITY_FS_USE_GENFS;
2529                 }
2530         }
2531
2532 out:
2533         read_unlock(&policy_rwlock);
2534         return rc;
2535 }
2536
2537 int security_get_bools(int *len, char ***names, int **values)
2538 {
2539         int i, rc;
2540
2541         read_lock(&policy_rwlock);
2542         *names = NULL;
2543         *values = NULL;
2544
2545         rc = 0;
2546         *len = policydb.p_bools.nprim;
2547         if (!*len)
2548                 goto out;
2549
2550         rc = -ENOMEM;
2551         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2552         if (!*names)
2553                 goto err;
2554
2555         rc = -ENOMEM;
2556         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2557         if (!*values)
2558                 goto err;
2559
2560         for (i = 0; i < *len; i++) {
2561                 size_t name_len;
2562
2563                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2564                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2565
2566                 rc = -ENOMEM;
2567                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2568                 if (!(*names)[i])
2569                         goto err;
2570
2571                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2572                 (*names)[i][name_len - 1] = 0;
2573         }
2574         rc = 0;
2575 out:
2576         read_unlock(&policy_rwlock);
2577         return rc;
2578 err:
2579         if (*names) {
2580                 for (i = 0; i < *len; i++)
2581                         kfree((*names)[i]);
2582         }
2583         kfree(*values);
2584         goto out;
2585 }
2586
2587
2588 int security_set_bools(int len, int *values)
2589 {
2590         int i, rc;
2591         int lenp, seqno = 0;
2592         struct cond_node *cur;
2593
2594         write_lock_irq(&policy_rwlock);
2595
2596         rc = -EFAULT;
2597         lenp = policydb.p_bools.nprim;
2598         if (len != lenp)
2599                 goto out;
2600
2601         for (i = 0; i < len; i++) {
2602                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2603                         audit_log(current->audit_context, GFP_ATOMIC,
2604                                 AUDIT_MAC_CONFIG_CHANGE,
2605                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2606                                 sym_name(&policydb, SYM_BOOLS, i),
2607                                 !!values[i],
2608                                 policydb.bool_val_to_struct[i]->state,
2609                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2610                                 audit_get_sessionid(current));
2611                 }
2612                 if (values[i])
2613                         policydb.bool_val_to_struct[i]->state = 1;
2614                 else
2615                         policydb.bool_val_to_struct[i]->state = 0;
2616         }
2617
2618         for (cur = policydb.cond_list; cur; cur = cur->next) {
2619                 rc = evaluate_cond_node(&policydb, cur);
2620                 if (rc)
2621                         goto out;
2622         }
2623
2624         seqno = ++latest_granting;
2625         rc = 0;
2626 out:
2627         write_unlock_irq(&policy_rwlock);
2628         if (!rc) {
2629                 avc_ss_reset(seqno);
2630                 selnl_notify_policyload(seqno);
2631                 selinux_status_update_policyload(seqno);
2632                 selinux_xfrm_notify_policyload();
2633         }
2634         return rc;
2635 }
2636
2637 int security_get_bool_value(int bool)
2638 {
2639         int rc;
2640         int len;
2641
2642         read_lock(&policy_rwlock);
2643
2644         rc = -EFAULT;
2645         len = policydb.p_bools.nprim;
2646         if (bool >= len)
2647                 goto out;
2648
2649         rc = policydb.bool_val_to_struct[bool]->state;
2650 out:
2651         read_unlock(&policy_rwlock);
2652         return rc;
2653 }
2654
2655 static int security_preserve_bools(struct policydb *p)
2656 {
2657         int rc, nbools = 0, *bvalues = NULL, i;
2658         char **bnames = NULL;
2659         struct cond_bool_datum *booldatum;
2660         struct cond_node *cur;
2661
2662         rc = security_get_bools(&nbools, &bnames, &bvalues);
2663         if (rc)
2664                 goto out;
2665         for (i = 0; i < nbools; i++) {
2666                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2667                 if (booldatum)
2668                         booldatum->state = bvalues[i];
2669         }
2670         for (cur = p->cond_list; cur; cur = cur->next) {
2671                 rc = evaluate_cond_node(p, cur);
2672                 if (rc)
2673                         goto out;
2674         }
2675
2676 out:
2677         if (bnames) {
2678                 for (i = 0; i < nbools; i++)
2679                         kfree(bnames[i]);
2680         }
2681         kfree(bnames);
2682         kfree(bvalues);
2683         return rc;
2684 }
2685
2686 /*
2687  * security_sid_mls_copy() - computes a new sid based on the given
2688  * sid and the mls portion of mls_sid.
2689  */
2690 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2691 {
2692         struct context *context1;
2693         struct context *context2;
2694         struct context newcon;
2695         char *s;
2696         u32 len;
2697         int rc;
2698
2699         rc = 0;
2700         if (!ss_initialized || !policydb.mls_enabled) {
2701                 *new_sid = sid;
2702                 goto out;
2703         }
2704
2705         context_init(&newcon);
2706
2707         read_lock(&policy_rwlock);
2708
2709         rc = -EINVAL;
2710         context1 = sidtab_search(&sidtab, sid);
2711         if (!context1) {
2712                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2713                         __func__, sid);
2714                 goto out_unlock;
2715         }
2716
2717         rc = -EINVAL;
2718         context2 = sidtab_search(&sidtab, mls_sid);
2719         if (!context2) {
2720                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2721                         __func__, mls_sid);
2722                 goto out_unlock;
2723         }
2724
2725         newcon.user = context1->user;
2726         newcon.role = context1->role;
2727         newcon.type = context1->type;
2728         rc = mls_context_cpy(&newcon, context2);
2729         if (rc)
2730                 goto out_unlock;
2731
2732         /* Check the validity of the new context. */
2733         if (!policydb_context_isvalid(&policydb, &newcon)) {
2734                 rc = convert_context_handle_invalid_context(&newcon);
2735                 if (rc) {
2736                         if (!context_struct_to_string(&newcon, &s, &len)) {
2737                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2738                                           "security_sid_mls_copy: invalid context %s", s);
2739                                 kfree(s);
2740                         }
2741                         goto out_unlock;
2742                 }
2743         }
2744
2745         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2746 out_unlock:
2747         read_unlock(&policy_rwlock);
2748         context_destroy(&newcon);
2749 out:
2750         return rc;
2751 }
2752
2753 /**
2754  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2755  * @nlbl_sid: NetLabel SID
2756  * @nlbl_type: NetLabel labeling protocol type
2757  * @xfrm_sid: XFRM SID
2758  *
2759  * Description:
2760  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2761  * resolved into a single SID it is returned via @peer_sid and the function
2762  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2763  * returns a negative value.  A table summarizing the behavior is below:
2764  *
2765  *                                 | function return |      @sid
2766  *   ------------------------------+-----------------+-----------------
2767  *   no peer labels                |        0        |    SECSID_NULL
2768  *   single peer label             |        0        |    <peer_label>
2769  *   multiple, consistent labels   |        0        |    <peer_label>
2770  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2771  *
2772  */
2773 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2774                                  u32 xfrm_sid,
2775                                  u32 *peer_sid)
2776 {
2777         int rc;
2778         struct context *nlbl_ctx;
2779         struct context *xfrm_ctx;
2780
2781         *peer_sid = SECSID_NULL;
2782
2783         /* handle the common (which also happens to be the set of easy) cases
2784          * right away, these two if statements catch everything involving a
2785          * single or absent peer SID/label */
2786         if (xfrm_sid == SECSID_NULL) {
2787                 *peer_sid = nlbl_sid;
2788                 return 0;
2789         }
2790         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2791          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2792          * is present */
2793         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2794                 *peer_sid = xfrm_sid;
2795                 return 0;
2796         }
2797
2798         /* we don't need to check ss_initialized here since the only way both
2799          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2800          * security server was initialized and ss_initialized was true */
2801         if (!policydb.mls_enabled)
2802                 return 0;
2803
2804         read_lock(&policy_rwlock);
2805
2806         rc = -EINVAL;
2807         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2808         if (!nlbl_ctx) {
2809                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2810                        __func__, nlbl_sid);
2811                 goto out;
2812         }
2813         rc = -EINVAL;
2814         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2815         if (!xfrm_ctx) {
2816                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2817                        __func__, xfrm_sid);
2818                 goto out;
2819         }
2820         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2821         if (rc)
2822                 goto out;
2823
2824         /* at present NetLabel SIDs/labels really only carry MLS
2825          * information so if the MLS portion of the NetLabel SID
2826          * matches the MLS portion of the labeled XFRM SID/label
2827          * then pass along the XFRM SID as it is the most
2828          * expressive */
2829         *peer_sid = xfrm_sid;
2830 out:
2831         read_unlock(&policy_rwlock);
2832         return rc;
2833 }
2834
2835 static int get_classes_callback(void *k, void *d, void *args)
2836 {
2837         struct class_datum *datum = d;
2838         char *name = k, **classes = args;
2839         int value = datum->value - 1;
2840
2841         classes[value] = kstrdup(name, GFP_ATOMIC);
2842         if (!classes[value])
2843                 return -ENOMEM;
2844
2845         return 0;
2846 }
2847
2848 int security_get_classes(char ***classes, int *nclasses)
2849 {
2850         int rc;
2851
2852         read_lock(&policy_rwlock);
2853
2854         rc = -ENOMEM;
2855         *nclasses = policydb.p_classes.nprim;
2856         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2857         if (!*classes)
2858                 goto out;
2859
2860         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2861                         *classes);
2862         if (rc) {
2863                 int i;
2864                 for (i = 0; i < *nclasses; i++)
2865                         kfree((*classes)[i]);
2866                 kfree(*classes);
2867         }
2868
2869 out:
2870         read_unlock(&policy_rwlock);
2871         return rc;
2872 }
2873
2874 static int get_permissions_callback(void *k, void *d, void *args)
2875 {
2876         struct perm_datum *datum = d;
2877         char *name = k, **perms = args;
2878         int value = datum->value - 1;
2879
2880         perms[value] = kstrdup(name, GFP_ATOMIC);
2881         if (!perms[value])
2882                 return -ENOMEM;
2883
2884         return 0;
2885 }
2886
2887 int security_get_permissions(char *class, char ***perms, int *nperms)
2888 {
2889         int rc, i;
2890         struct class_datum *match;
2891
2892         read_lock(&policy_rwlock);
2893
2894         rc = -EINVAL;
2895         match = hashtab_search(policydb.p_classes.table, class);
2896         if (!match) {
2897                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2898                         __func__, class);
2899                 goto out;
2900         }
2901
2902         rc = -ENOMEM;
2903         *nperms = match->permissions.nprim;
2904         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2905         if (!*perms)
2906                 goto out;
2907
2908         if (match->comdatum) {
2909                 rc = hashtab_map(match->comdatum->permissions.table,
2910                                 get_permissions_callback, *perms);
2911                 if (rc)
2912                         goto err;
2913         }
2914
2915         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2916                         *perms);
2917         if (rc)
2918                 goto err;
2919
2920 out:
2921         read_unlock(&policy_rwlock);
2922         return rc;
2923
2924 err:
2925         read_unlock(&policy_rwlock);
2926         for (i = 0; i < *nperms; i++)
2927                 kfree((*perms)[i]);
2928         kfree(*perms);
2929         return rc;
2930 }
2931
2932 int security_get_reject_unknown(void)
2933 {
2934         return policydb.reject_unknown;
2935 }
2936
2937 int security_get_allow_unknown(void)
2938 {
2939         return policydb.allow_unknown;
2940 }
2941
2942 /**
2943  * security_policycap_supported - Check for a specific policy capability
2944  * @req_cap: capability
2945  *
2946  * Description:
2947  * This function queries the currently loaded policy to see if it supports the
2948  * capability specified by @req_cap.  Returns true (1) if the capability is
2949  * supported, false (0) if it isn't supported.
2950  *
2951  */
2952 int security_policycap_supported(unsigned int req_cap)
2953 {
2954         int rc;
2955
2956         read_lock(&policy_rwlock);
2957         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2958         read_unlock(&policy_rwlock);
2959
2960         return rc;
2961 }
2962
2963 struct selinux_audit_rule {
2964         u32 au_seqno;
2965         struct context au_ctxt;
2966 };
2967
2968 void selinux_audit_rule_free(void *vrule)
2969 {
2970         struct selinux_audit_rule *rule = vrule;
2971
2972         if (rule) {
2973                 context_destroy(&rule->au_ctxt);
2974                 kfree(rule);
2975         }
2976 }
2977
2978 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2979 {
2980         struct selinux_audit_rule *tmprule;
2981         struct role_datum *roledatum;
2982         struct type_datum *typedatum;
2983         struct user_datum *userdatum;
2984         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2985         int rc = 0;
2986
2987         *rule = NULL;
2988
2989         if (!ss_initialized)
2990                 return -EOPNOTSUPP;
2991
2992         switch (field) {
2993         case AUDIT_SUBJ_USER:
2994         case AUDIT_SUBJ_ROLE:
2995         case AUDIT_SUBJ_TYPE:
2996         case AUDIT_OBJ_USER:
2997         case AUDIT_OBJ_ROLE:
2998         case AUDIT_OBJ_TYPE:
2999                 /* only 'equals' and 'not equals' fit user, role, and type */
3000                 if (op != Audit_equal && op != Audit_not_equal)
3001                         return -EINVAL;
3002                 break;
3003         case AUDIT_SUBJ_SEN:
3004         case AUDIT_SUBJ_CLR:
3005         case AUDIT_OBJ_LEV_LOW:
3006         case AUDIT_OBJ_LEV_HIGH:
3007                 /* we do not allow a range, indicated by the presence of '-' */
3008                 if (strchr(rulestr, '-'))
3009                         return -EINVAL;
3010                 break;
3011         default:
3012                 /* only the above fields are valid */
3013                 return -EINVAL;
3014         }
3015
3016         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3017         if (!tmprule)
3018                 return -ENOMEM;
3019
3020         context_init(&tmprule->au_ctxt);
3021
3022         read_lock(&policy_rwlock);
3023
3024         tmprule->au_seqno = latest_granting;
3025
3026         switch (field) {
3027         case AUDIT_SUBJ_USER:
3028         case AUDIT_OBJ_USER:
3029                 rc = -EINVAL;
3030                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3031                 if (!userdatum)
3032                         goto out;
3033                 tmprule->au_ctxt.user = userdatum->value;
3034                 break;
3035         case AUDIT_SUBJ_ROLE:
3036         case AUDIT_OBJ_ROLE:
3037                 rc = -EINVAL;
3038                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3039                 if (!roledatum)
3040                         goto out;
3041                 tmprule->au_ctxt.role = roledatum->value;
3042                 break;
3043         case AUDIT_SUBJ_TYPE:
3044         case AUDIT_OBJ_TYPE:
3045                 rc = -EINVAL;
3046                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3047                 if (!typedatum)
3048                         goto out;
3049                 tmprule->au_ctxt.type = typedatum->value;
3050                 break;
3051         case AUDIT_SUBJ_SEN:
3052         case AUDIT_SUBJ_CLR:
3053         case AUDIT_OBJ_LEV_LOW:
3054         case AUDIT_OBJ_LEV_HIGH:
3055                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3056                 if (rc)
3057                         goto out;
3058                 break;
3059         }
3060         rc = 0;
3061 out:
3062         read_unlock(&policy_rwlock);
3063
3064         if (rc) {
3065                 selinux_audit_rule_free(tmprule);
3066                 tmprule = NULL;
3067         }
3068
3069         *rule = tmprule;
3070
3071         return rc;
3072 }
3073
3074 /* Check to see if the rule contains any selinux fields */
3075 int selinux_audit_rule_known(struct audit_krule *rule)
3076 {
3077         int i;
3078
3079         for (i = 0; i < rule->field_count; i++) {
3080                 struct audit_field *f = &rule->fields[i];
3081                 switch (f->type) {
3082                 case AUDIT_SUBJ_USER:
3083                 case AUDIT_SUBJ_ROLE:
3084                 case AUDIT_SUBJ_TYPE:
3085                 case AUDIT_SUBJ_SEN:
3086                 case AUDIT_SUBJ_CLR:
3087                 case AUDIT_OBJ_USER:
3088                 case AUDIT_OBJ_ROLE:
3089                 case AUDIT_OBJ_TYPE:
3090                 case AUDIT_OBJ_LEV_LOW:
3091                 case AUDIT_OBJ_LEV_HIGH:
3092                         return 1;
3093                 }
3094         }
3095
3096         return 0;
3097 }
3098
3099 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3100                              struct audit_context *actx)
3101 {
3102         struct context *ctxt;
3103         struct mls_level *level;
3104         struct selinux_audit_rule *rule = vrule;
3105         int match = 0;
3106
3107         if (!rule) {
3108                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3109                           "selinux_audit_rule_match: missing rule\n");
3110                 return -ENOENT;
3111         }
3112
3113         read_lock(&policy_rwlock);
3114
3115         if (rule->au_seqno < latest_granting) {
3116                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3117                           "selinux_audit_rule_match: stale rule\n");
3118                 match = -ESTALE;
3119                 goto out;
3120         }
3121
3122         ctxt = sidtab_search(&sidtab, sid);
3123         if (!ctxt) {
3124                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3125                           "selinux_audit_rule_match: unrecognized SID %d\n",
3126                           sid);
3127                 match = -ENOENT;
3128                 goto out;
3129         }
3130
3131         /* a field/op pair that is not caught here will simply fall through
3132            without a match */
3133         switch (field) {
3134         case AUDIT_SUBJ_USER:
3135         case AUDIT_OBJ_USER:
3136                 switch (op) {
3137                 case Audit_equal:
3138                         match = (ctxt->user == rule->au_ctxt.user);
3139                         break;
3140                 case Audit_not_equal:
3141                         match = (ctxt->user != rule->au_ctxt.user);
3142                         break;
3143                 }
3144                 break;
3145         case AUDIT_SUBJ_ROLE:
3146         case AUDIT_OBJ_ROLE:
3147                 switch (op) {
3148                 case Audit_equal:
3149                         match = (ctxt->role == rule->au_ctxt.role);
3150                         break;
3151                 case Audit_not_equal:
3152                         match = (ctxt->role != rule->au_ctxt.role);
3153                         break;
3154                 }
3155                 break;
3156         case AUDIT_SUBJ_TYPE:
3157         case AUDIT_OBJ_TYPE:
3158                 switch (op) {
3159                 case Audit_equal:
3160                         match = (ctxt->type == rule->au_ctxt.type);
3161                         break;
3162                 case Audit_not_equal:
3163                         match = (ctxt->type != rule->au_ctxt.type);
3164                         break;
3165                 }
3166                 break;
3167         case AUDIT_SUBJ_SEN:
3168         case AUDIT_SUBJ_CLR:
3169         case AUDIT_OBJ_LEV_LOW:
3170         case AUDIT_OBJ_LEV_HIGH:
3171                 level = ((field == AUDIT_SUBJ_SEN ||
3172                           field == AUDIT_OBJ_LEV_LOW) ?
3173                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3174                 switch (op) {
3175                 case Audit_equal:
3176                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3177                                              level);
3178                         break;
3179                 case Audit_not_equal:
3180                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3181                                               level);
3182                         break;
3183                 case Audit_lt:
3184                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3185                                                level) &&
3186                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3187                                                level));
3188                         break;
3189                 case Audit_le:
3190                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3191                                               level);
3192                         break;
3193                 case Audit_gt:
3194                         match = (mls_level_dom(level,
3195                                               &rule->au_ctxt.range.level[0]) &&
3196                                  !mls_level_eq(level,
3197                                                &rule->au_ctxt.range.level[0]));
3198                         break;
3199                 case Audit_ge:
3200                         match = mls_level_dom(level,
3201                                               &rule->au_ctxt.range.level[0]);
3202                         break;
3203                 }
3204         }
3205
3206 out:
3207         read_unlock(&policy_rwlock);
3208         return match;
3209 }
3210
3211 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3212
3213 static int aurule_avc_callback(u32 event)
3214 {
3215         int err = 0;
3216
3217         if (event == AVC_CALLBACK_RESET && aurule_callback)
3218                 err = aurule_callback();
3219         return err;
3220 }
3221
3222 static int __init aurule_init(void)
3223 {
3224         int err;
3225
3226         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3227         if (err)
3228                 panic("avc_add_callback() failed, error %d\n", err);
3229
3230         return err;
3231 }
3232 __initcall(aurule_init);
3233
3234 #ifdef CONFIG_NETLABEL
3235 /**
3236  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3237  * @secattr: the NetLabel packet security attributes
3238  * @sid: the SELinux SID
3239  *
3240  * Description:
3241  * Attempt to cache the context in @ctx, which was derived from the packet in
3242  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3243  * already been initialized.
3244  *
3245  */
3246 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3247                                       u32 sid)
3248 {
3249         u32 *sid_cache;
3250
3251         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3252         if (sid_cache == NULL)
3253                 return;
3254         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3255         if (secattr->cache == NULL) {
3256                 kfree(sid_cache);
3257                 return;
3258         }
3259
3260         *sid_cache = sid;
3261         secattr->cache->free = kfree;
3262         secattr->cache->data = sid_cache;
3263         secattr->flags |= NETLBL_SECATTR_CACHE;
3264 }
3265
3266 /**
3267  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3268  * @secattr: the NetLabel packet security attributes
3269  * @sid: the SELinux SID
3270  *
3271  * Description:
3272  * Convert the given NetLabel security attributes in @secattr into a
3273  * SELinux SID.  If the @secattr field does not contain a full SELinux
3274  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3275  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3276  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3277  * conversion for future lookups.  Returns zero on success, negative values on
3278  * failure.
3279  *
3280  */
3281 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3282                                    u32 *sid)
3283 {
3284         int rc;
3285         struct context *ctx;
3286         struct context ctx_new;
3287
3288         if (!ss_initialized) {
3289                 *sid = SECSID_NULL;
3290                 return 0;
3291         }
3292
3293         read_lock(&policy_rwlock);
3294
3295         if (secattr->flags & NETLBL_SECATTR_CACHE)
3296                 *sid = *(u32 *)secattr->cache->data;
3297         else if (secattr->flags & NETLBL_SECATTR_SECID)
3298                 *sid = secattr->attr.secid;
3299         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3300                 rc = -EIDRM;
3301                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3302                 if (ctx == NULL)
3303                         goto out;
3304
3305                 context_init(&ctx_new);
3306                 ctx_new.user = ctx->user;
3307                 ctx_new.role = ctx->role;
3308                 ctx_new.type = ctx->type;
3309                 mls_import_netlbl_lvl(&ctx_new, secattr);
3310                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3311                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3312                                                    secattr->attr.mls.cat);
3313                         if (rc)
3314                                 goto out;
3315                         memcpy(&ctx_new.range.level[1].cat,
3316                                &ctx_new.range.level[0].cat,
3317                                sizeof(ctx_new.range.level[0].cat));
3318                 }
3319                 rc = -EIDRM;
3320                 if (!mls_context_isvalid(&policydb, &ctx_new))
3321                         goto out_free;
3322
3323                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3324                 if (rc)
3325                         goto out_free;
3326
3327                 security_netlbl_cache_add(secattr, *sid);
3328
3329                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3330         } else
3331                 *sid = SECSID_NULL;
3332
3333         read_unlock(&policy_rwlock);
3334         return 0;
3335 out_free:
3336         ebitmap_destroy(&ctx_new.range.level[0].cat);
3337 out:
3338         read_unlock(&policy_rwlock);
3339         return rc;
3340 }
3341
3342 /**
3343  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3344  * @sid: the SELinux SID
3345  * @secattr: the NetLabel packet security attributes
3346  *
3347  * Description:
3348  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3349  * Returns zero on success, negative values on failure.
3350  *
3351  */
3352 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3353 {
3354         int rc;
3355         struct context *ctx;
3356
3357         if (!ss_initialized)
3358                 return 0;
3359
3360         read_lock(&policy_rwlock);
3361
3362         rc = -ENOENT;
3363         ctx = sidtab_search(&sidtab, sid);
3364         if (ctx == NULL)
3365                 goto out;
3366
3367         rc = -ENOMEM;
3368         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3369                                   GFP_ATOMIC);
3370         if (secattr->domain == NULL)
3371                 goto out;
3372
3373         secattr->attr.secid = sid;
3374         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3375         mls_export_netlbl_lvl(ctx, secattr);
3376         rc = mls_export_netlbl_cat(ctx, secattr);
3377 out:
3378         read_unlock(&policy_rwlock);
3379         return rc;
3380 }
3381 #endif /* CONFIG_NETLABEL */
3382
3383 /**
3384  * security_read_policy - read the policy.
3385  * @data: binary policy data
3386  * @len: length of data in bytes
3387  *
3388  */
3389 int security_read_policy(void **data, size_t *len)
3390 {
3391         int rc;
3392         struct policy_file fp;
3393
3394         if (!ss_initialized)
3395                 return -EINVAL;
3396
3397         *len = security_policydb_len();
3398
3399         *data = vmalloc_user(*len);
3400         if (!*data)
3401                 return -ENOMEM;
3402
3403         fp.data = *data;
3404         fp.len = *len;
3405
3406         read_lock(&policy_rwlock);
3407         rc = policydb_write(&policydb, &fp);
3408         read_unlock(&policy_rwlock);
3409
3410         if (rc)
3411                 return rc;
3412
3413         *len = (unsigned long)fp.data - (unsigned long)*data;
3414         return 0;
3415
3416 }