Pileus Git - ~andy/linux/blob - security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   5  *           James Morris <jmorris@redhat.com>
   6  *
   7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8  *
   9  *      Support for enhanced MLS infrastructure.
  10  *      Support for context based audit filters.
  11  *
  12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  13  *
  14  *      Added conditional policy language extensions
  15  *
  16  * Updated: Hewlett-Packard <paul@paul-moore.com>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <csellers@tresys.com>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <guido@trentalancia.com>
  30  *
  31  *  Added support for runtime switching of the policy type
  32  *
  33  * Copyright (C) 2008, 2009 NEC Corporation
  34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  38  *      This program is free software; you can redistribute it and/or modify
  39  *      it under the terms of the GNU General Public License as published by
  40  *      the Free Software Foundation, version 2.
  41  */
  42 #include <linux/kernel.h>
  43 #include <linux/slab.h>
  44 #include <linux/string.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/errno.h>
  48 #include <linux/in.h>
  49 #include <linux/sched.h>
  50 #include <linux/audit.h>
  51 #include <linux/mutex.h>
  52 #include <linux/selinux.h>
  53 #include <linux/flex_array.h>
  54 #include <linux/vmalloc.h>
  55 #include <net/netlabel.h>
  56
  57 #include "flask.h"
  58 #include "avc.h"
  59 #include "avc_ss.h"
  60 #include "security.h"
  61 #include "context.h"
  62 #include "policydb.h"
  63 #include "sidtab.h"
  64 #include "services.h"
  65 #include "conditional.h"
  66 #include "mls.h"
  67 #include "objsec.h"
  68 #include "netlabel.h"
  69 #include "xfrm.h"
  70 #include "ebitmap.h"
  71 #include "audit.h"
  72
  73 int selinux_policycap_netpeer;
  74 int selinux_policycap_openperm;
  75 int selinux_policycap_alwaysnetwork;
  76
  77 static DEFINE_RWLOCK(policy_rwlock);
  78
  79 static struct sidtab sidtab;
  80 struct policydb policydb;
  81 int ss_initialized;
  82
  83 /*
  84  * The largest sequence number that has been used when
  85  * providing an access decision to the access vector cache.
  86  * The sequence number only changes when a policy change
  87  * occurs.
  88  */
  89 static u32 latest_granting;
  90
  91 /* Forward declaration. */
  92 static int context_struct_to_string(struct context *context, char **scontext,
  93                                     u32 *scontext_len);
  94
  95 static void context_struct_compute_av(struct context *scontext,
  96                                       struct context *tcontext,
  97                                       u16 tclass,
  98                                       struct av_decision *avd);
  99
 100 struct selinux_mapping {
 101         u16 value; /* policy value */
 102         unsigned num_perms;
 103         u32 perms[sizeof(u32) * 8];
 104 };
 105
 106 static struct selinux_mapping *current_mapping;
 107 static u16 current_mapping_size;
 108
 109 static int selinux_set_mapping(struct policydb *pol,
 110                                struct security_class_mapping *map,
 111                                struct selinux_mapping **out_map_p,
 112                                u16 *out_map_size)
 113 {
 114         struct selinux_mapping *out_map = NULL;
 115         size_t size = sizeof(struct selinux_mapping);
 116         u16 i, j;
 117         unsigned k;
 118         bool print_unknown_handle = false;
 119
 120         /* Find number of classes in the input mapping */
 121         if (!map)
 122                 return -EINVAL;
 123         i = 0;
 124         while (map[i].name)
 125                 i++;
 126
 127         /* Allocate space for the class records, plus one for class zero */
 128         out_map = kcalloc(++i, size, GFP_ATOMIC);
 129         if (!out_map)
 130                 return -ENOMEM;
 131
 132         /* Store the raw class and permission values */
 133         j = 0;
 134         while (map[j].name) {
 135                 struct security_class_mapping *p_in = map + (j++);
 136                 struct selinux_mapping *p_out = out_map + j;
 137
 138                 /* An empty class string skips ahead */
 139                 if (!strcmp(p_in->name, "")) {
 140                         p_out->num_perms = 0;
 141                         continue;
 142                 }
 143
 144                 p_out->value = string_to_security_class(pol, p_in->name);
 145                 if (!p_out->value) {
 146                         printk(KERN_INFO
 147                                "SELinux:  Class %s not defined in policy.\n",
 148                                p_in->name);
 149                         if (pol->reject_unknown)
 150                                 goto err;
 151                         p_out->num_perms = 0;
 152                         print_unknown_handle = true;
 153                         continue;
 154                 }
 155
 156                 k = 0;
 157                 while (p_in->perms && p_in->perms[k]) {
 158                         /* An empty permission string skips ahead */
 159                         if (!*p_in->perms[k]) {
 160                                 k++;
 161                                 continue;
 162                         }
 163                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 164                                                             p_in->perms[k]);
 165                         if (!p_out->perms[k]) {
 166                                 printk(KERN_INFO
 167                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 168                                        p_in->perms[k], p_in->name);
 169                                 if (pol->reject_unknown)
 170                                         goto err;
 171                                 print_unknown_handle = true;
 172                         }
 173
 174                         k++;
 175                 }
 176                 p_out->num_perms = k;
 177         }
 178
 179         if (print_unknown_handle)
 180                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 181                        pol->allow_unknown ? "allowed" : "denied");
 182
 183         *out_map_p = out_map;
 184         *out_map_size = i;
 185         return 0;
 186 err:
 187         kfree(out_map);
 188         return -EINVAL;
 189 }
 190
 191 /*
 192  * Get real, policy values from mapped values
 193  */
 194
 195 static u16 unmap_class(u16 tclass)
 196 {
 197         if (tclass < current_mapping_size)
 198                 return current_mapping[tclass].value;
 199
 200         return tclass;
 201 }
 202
 203 /*
 204  * Get kernel value for class from its policy value
 205  */
 206 static u16 map_class(u16 pol_value)
 207 {
 208         u16 i;
 209
 210         for (i = 1; i < current_mapping_size; i++) {
 211                 if (current_mapping[i].value == pol_value)
 212                         return i;
 213         }
 214
 215         return SECCLASS_NULL;
 216 }
 217
 218 static void map_decision(u16 tclass, struct av_decision *avd,
 219                          int allow_unknown)
 220 {
 221         if (tclass < current_mapping_size) {
 222                 unsigned i, n = current_mapping[tclass].num_perms;
 223                 u32 result;
 224
 225                 for (i = 0, result = 0; i < n; i++) {
 226                         if (avd->allowed & current_mapping[tclass].perms[i])
 227                                 result |= 1<<i;
 228                         if (allow_unknown && !current_mapping[tclass].perms[i])
 229                                 result |= 1<<i;
 230                 }
 231                 avd->allowed = result;
 232
 233                 for (i = 0, result = 0; i < n; i++)
 234                         if (avd->auditallow & current_mapping[tclass].perms[i])
 235                                 result |= 1<<i;
 236                 avd->auditallow = result;
 237
 238                 for (i = 0, result = 0; i < n; i++) {
 239                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 240                                 result |= 1<<i;
 241                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 242                                 result |= 1<<i;
 243                 }
 244                 /*
 245                  * In case the kernel has a bug and requests a permission
 246                  * between num_perms and the maximum permission number, we
 247                  * should audit that denial
 248                  */
 249                 for (; i < (sizeof(u32)*8); i++)
 250                         result |= 1<<i;
 251                 avd->auditdeny = result;
 252         }
 253 }
 254
 255 int security_mls_enabled(void)
 256 {
 257         return policydb.mls_enabled;
 258 }
 259
 260 /*
 261  * Return the boolean value of a constraint expression
 262  * when it is applied to the specified source and target
 263  * security contexts.
 264  *
 265  * xcontext is a special beast...  It is used by the validatetrans rules
 266  * only.  For these rules, scontext is the context before the transition,
 267  * tcontext is the context after the transition, and xcontext is the context
 268  * of the process performing the transition.  All other callers of
 269  * constraint_expr_eval should pass in NULL for xcontext.
 270  */
 271 static int constraint_expr_eval(struct context *scontext,
 272                                 struct context *tcontext,
 273                                 struct context *xcontext,
 274                                 struct constraint_expr *cexpr)
 275 {
 276         u32 val1, val2;
 277         struct context *c;
 278         struct role_datum *r1, *r2;
 279         struct mls_level *l1, *l2;
 280         struct constraint_expr *e;
 281         int s[CEXPR_MAXDEPTH];
 282         int sp = -1;
 283
 284         for (e = cexpr; e; e = e->next) {
 285                 switch (e->expr_type) {
 286                 case CEXPR_NOT:
 287                         BUG_ON(sp < 0);
 288                         s[sp] = !s[sp];
 289                         break;
 290                 case CEXPR_AND:
 291                         BUG_ON(sp < 1);
 292                         sp--;
 293                         s[sp] &= s[sp + 1];
 294                         break;
 295                 case CEXPR_OR:
 296                         BUG_ON(sp < 1);
 297                         sp--;
 298                         s[sp] |= s[sp + 1];
 299                         break;
 300                 case CEXPR_ATTR:
 301                         if (sp == (CEXPR_MAXDEPTH - 1))
 302                                 return 0;
 303                         switch (e->attr) {
 304                         case CEXPR_USER:
 305                                 val1 = scontext->user;
 306                                 val2 = tcontext->user;
 307                                 break;
 308                         case CEXPR_TYPE:
 309                                 val1 = scontext->type;
 310                                 val2 = tcontext->type;
 311                                 break;
 312                         case CEXPR_ROLE:
 313                                 val1 = scontext->role;
 314                                 val2 = tcontext->role;
 315                                 r1 = policydb.role_val_to_struct[val1 - 1];
 316                                 r2 = policydb.role_val_to_struct[val2 - 1];
 317                                 switch (e->op) {
 318                                 case CEXPR_DOM:
 319                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 320                                                                   val2 - 1);
 321                                         continue;
 322                                 case CEXPR_DOMBY:
 323                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 324                                                                   val1 - 1);
 325                                         continue;
 326                                 case CEXPR_INCOMP:
 327                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 328                                                                     val2 - 1) &&
 329                                                    !ebitmap_get_bit(&r2->dominates,
 330                                                                     val1 - 1));
 331                                         continue;
 332                                 default:
 333                                         break;
 334                                 }
 335                                 break;
 336                         case CEXPR_L1L2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_L1H2:
 341                                 l1 = &(scontext->range.level[0]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1L2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[0]);
 347                                 goto mls_ops;
 348                         case CEXPR_H1H2:
 349                                 l1 = &(scontext->range.level[1]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L1H1:
 353                                 l1 = &(scontext->range.level[0]);
 354                                 l2 = &(scontext->range.level[1]);
 355                                 goto mls_ops;
 356                         case CEXPR_L2H2:
 357                                 l1 = &(tcontext->range.level[0]);
 358                                 l2 = &(tcontext->range.level[1]);
 359                                 goto mls_ops;
 360 mls_ops:
 361                         switch (e->op) {
 362                         case CEXPR_EQ:
 363                                 s[++sp] = mls_level_eq(l1, l2);
 364                                 continue;
 365                         case CEXPR_NEQ:
 366                                 s[++sp] = !mls_level_eq(l1, l2);
 367                                 continue;
 368                         case CEXPR_DOM:
 369                                 s[++sp] = mls_level_dom(l1, l2);
 370                                 continue;
 371                         case CEXPR_DOMBY:
 372                                 s[++sp] = mls_level_dom(l2, l1);
 373                                 continue;
 374                         case CEXPR_INCOMP:
 375                                 s[++sp] = mls_level_incomp(l2, l1);
 376                                 continue;
 377                         default:
 378                                 BUG();
 379                                 return 0;
 380                         }
 381                         break;
 382                         default:
 383                                 BUG();
 384                                 return 0;
 385                         }
 386
 387                         switch (e->op) {
 388                         case CEXPR_EQ:
 389                                 s[++sp] = (val1 == val2);
 390                                 break;
 391                         case CEXPR_NEQ:
 392                                 s[++sp] = (val1 != val2);
 393                                 break;
 394                         default:
 395                                 BUG();
 396                                 return 0;
 397                         }
 398                         break;
 399                 case CEXPR_NAMES:
 400                         if (sp == (CEXPR_MAXDEPTH-1))
 401                                 return 0;
 402                         c = scontext;
 403                         if (e->attr & CEXPR_TARGET)
 404                                 c = tcontext;
 405                         else if (e->attr & CEXPR_XTARGET) {
 406                                 c = xcontext;
 407                                 if (!c) {
 408                                         BUG();
 409                                         return 0;
 410                                 }
 411                         }
 412                         if (e->attr & CEXPR_USER)
 413                                 val1 = c->user;
 414                         else if (e->attr & CEXPR_ROLE)
 415                                 val1 = c->role;
 416                         else if (e->attr & CEXPR_TYPE)
 417                                 val1 = c->type;
 418                         else {
 419                                 BUG();
 420                                 return 0;
 421                         }
 422
 423                         switch (e->op) {
 424                         case CEXPR_EQ:
 425                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         case CEXPR_NEQ:
 428                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         default:
 431                                 BUG();
 432                                 return 0;
 433                         }
 434                         break;
 435                 default:
 436                         BUG();
 437                         return 0;
 438                 }
 439         }
 440
 441         BUG_ON(sp != 0);
 442         return s[0];
 443 }
 444
 445 /*
 446  * security_dump_masked_av - dumps masked permissions during
 447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 448  */
 449 static int dump_masked_av_helper(void *k, void *d, void *args)
 450 {
 451         struct perm_datum *pdatum = d;
 452         char **permission_names = args;
 453
 454         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 455
 456         permission_names[pdatum->value - 1] = (char *)k;
 457
 458         return 0;
 459 }
 460
 461 static void security_dump_masked_av(struct context *scontext,
 462                                     struct context *tcontext,
 463                                     u16 tclass,
 464                                     u32 permissions,
 465                                     const char *reason)
 466 {
 467         struct common_datum *common_dat;
 468         struct class_datum *tclass_dat;
 469         struct audit_buffer *ab;
 470         char *tclass_name;
 471         char *scontext_name = NULL;
 472         char *tcontext_name = NULL;
 473         char *permission_names[32];
 474         int index;
 475         u32 length;
 476         bool need_comma = false;
 477
 478         if (!permissions)
 479                 return;
 480
 481         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 482         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 483         common_dat = tclass_dat->comdatum;
 484
 485         /* init permission_names */
 486         if (common_dat &&
 487             hashtab_map(common_dat->permissions.table,
 488                         dump_masked_av_helper, permission_names) < 0)
 489                 goto out;
 490
 491         if (hashtab_map(tclass_dat->permissions.table,
 492                         dump_masked_av_helper, permission_names) < 0)
 493                 goto out;
 494
 495         /* get scontext/tcontext in text form */
 496         if (context_struct_to_string(scontext,
 497                                      &scontext_name, &length) < 0)
 498                 goto out;
 499
 500         if (context_struct_to_string(tcontext,
 501                                      &tcontext_name, &length) < 0)
 502                 goto out;
 503
 504         /* audit a message */
 505         ab = audit_log_start(current->audit_context,
 506                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 507         if (!ab)
 508                 goto out;
 509
 510         audit_log_format(ab, "op=security_compute_av reason=%s "
 511                          "scontext=%s tcontext=%s tclass=%s perms=",
 512                          reason, scontext_name, tcontext_name, tclass_name);
 513
 514         for (index = 0; index < 32; index++) {
 515                 u32 mask = (1 << index);
 516
 517                 if ((mask & permissions) == 0)
 518                         continue;
 519
 520                 audit_log_format(ab, "%s%s",
 521                                  need_comma ? "," : "",
 522                                  permission_names[index]
 523                                  ? permission_names[index] : "????");
 524                 need_comma = true;
 525         }
 526         audit_log_end(ab);
 527 out:
 528         /* release scontext/tcontext */
 529         kfree(tcontext_name);
 530         kfree(scontext_name);
 531
 532         return;
 533 }
 534
 535 /*
 536  * security_boundary_permission - drops violated permissions
 537  * on boundary constraint.
 538  */
 539 static void type_attribute_bounds_av(struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 552                                     scontext->type - 1);
 553         BUG_ON(!source);
 554
 555         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 556                                     tcontext->type - 1);
 557         BUG_ON(!target);
 558
 559         if (source->bounds) {
 560                 memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563                 lo_scontext.type = source->bounds;
 564
 565                 context_struct_compute_av(&lo_scontext,
 566                                           tcontext,
 567                                           tclass,
 568                                           &lo_avd);
 569                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 570                         return;         /* no masked permission */
 571                 masked = ~lo_avd.allowed & avd->allowed;
 572         }
 573
 574         if (target->bounds) {
 575                 memset(&lo_avd, 0, sizeof(lo_avd));
 576
 577                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 578                 lo_tcontext.type = target->bounds;
 579
 580                 context_struct_compute_av(scontext,
 581                                           &lo_tcontext,
 582                                           tclass,
 583                                           &lo_avd);
 584                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 585                         return;         /* no masked permission */
 586                 masked = ~lo_avd.allowed & avd->allowed;
 587         }
 588
 589         if (source->bounds && target->bounds) {
 590                 memset(&lo_avd, 0, sizeof(lo_avd));
 591                 /*
 592                  * lo_scontext and lo_tcontext are already
 593                  * set up.
 594                  */
 595
 596                 context_struct_compute_av(&lo_scontext,
 597                                           &lo_tcontext,
 598                                           tclass,
 599                                           &lo_avd);
 600                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 601                         return;         /* no masked permission */
 602                 masked = ~lo_avd.allowed & avd->allowed;
 603         }
 604
 605         if (masked) {
 606                 /* mask violated permissions */
 607                 avd->allowed &= ~masked;
 608
 609                 /* audit masked permissions */
 610                 security_dump_masked_av(scontext, tcontext,
 611                                         tclass, masked, "bounds");
 612         }
 613 }
 614
 615 /*
 616  * Compute access vectors based on a context structure pair for
 617  * the permissions in a particular class.
 618  */
 619 static void context_struct_compute_av(struct context *scontext,
 620                                       struct context *tcontext,
 621                                       u16 tclass,
 622                                       struct av_decision *avd)
 623 {
 624         struct constraint_node *constraint;
 625         struct role_allow *ra;
 626         struct avtab_key avkey;
 627         struct avtab_node *node;
 628         struct class_datum *tclass_datum;
 629         struct ebitmap *sattr, *tattr;
 630         struct ebitmap_node *snode, *tnode;
 631         unsigned int i, j;
 632
 633         avd->allowed = 0;
 634         avd->auditallow = 0;
 635         avd->auditdeny = 0xffffffff;
 636
 637         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 638                 if (printk_ratelimit())
 639                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 640                 return;
 641         }
 642
 643         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 644
 645         /*
 646          * If a specific type enforcement rule was defined for
 647          * this permission check, then use it.
 648          */
 649         avkey.target_class = tclass;
 650         avkey.specified = AVTAB_AV;
 651         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 652         BUG_ON(!sattr);
 653         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 654         BUG_ON(!tattr);
 655         ebitmap_for_each_positive_bit(sattr, snode, i) {
 656                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 657                         avkey.source_type = i + 1;
 658                         avkey.target_type = j + 1;
 659                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 660                              node;
 661                              node = avtab_search_node_next(node, avkey.specified)) {
 662                                 if (node->key.specified == AVTAB_ALLOWED)
 663                                         avd->allowed |= node->datum.data;
 664                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 665                                         avd->auditallow |= node->datum.data;
 666                                 else if (node->key.specified == AVTAB_AUDITDENY)
 667                                         avd->auditdeny &= node->datum.data;
 668                         }
 669
 670                         /* Check conditional av table for additional permissions */
 671                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 672
 673                 }
 674         }
 675
 676         /*
 677          * Remove any permissions prohibited by a constraint (this includes
 678          * the MLS policy).
 679          */
 680         constraint = tclass_datum->constraints;
 681         while (constraint) {
 682                 if ((constraint->permissions & (avd->allowed)) &&
 683                     !constraint_expr_eval(scontext, tcontext, NULL,
 684                                           constraint->expr)) {
 685                         avd->allowed &= ~(constraint->permissions);
 686                 }
 687                 constraint = constraint->next;
 688         }
 689
 690         /*
 691          * If checking process transition permission and the
 692          * role is changing, then check the (current_role, new_role)
 693          * pair.
 694          */
 695         if (tclass == policydb.process_class &&
 696             (avd->allowed & policydb.process_trans_perms) &&
 697             scontext->role != tcontext->role) {
 698                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 699                         if (scontext->role == ra->role &&
 700                             tcontext->role == ra->new_role)
 701                                 break;
 702                 }
 703                 if (!ra)
 704                         avd->allowed &= ~policydb.process_trans_perms;
 705         }
 706
 707         /*
 708          * If the given source and target types have boundary
 709          * constraint, lazy checks have to mask any violated
 710          * permission and notice it to userspace via audit.
 711          */
 712         type_attribute_bounds_av(scontext, tcontext,
 713                                  tclass, avd);
 714 }
 715
 716 static int security_validtrans_handle_fail(struct context *ocontext,
 717                                            struct context *ncontext,
 718                                            struct context *tcontext,
 719                                            u16 tclass)
 720 {
 721         char *o = NULL, *n = NULL, *t = NULL;
 722         u32 olen, nlen, tlen;
 723
 724         if (context_struct_to_string(ocontext, &o, &olen))
 725                 goto out;
 726         if (context_struct_to_string(ncontext, &n, &nlen))
 727                 goto out;
 728         if (context_struct_to_string(tcontext, &t, &tlen))
 729                 goto out;
 730         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 731                   "security_validate_transition:  denied for"
 732                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 733                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 734 out:
 735         kfree(o);
 736         kfree(n);
 737         kfree(t);
 738
 739         if (!selinux_enforcing)
 740                 return 0;
 741         return -EPERM;
 742 }
 743
 744 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 745                                  u16 orig_tclass)
 746 {
 747         struct context *ocontext;
 748         struct context *ncontext;
 749         struct context *tcontext;
 750         struct class_datum *tclass_datum;
 751         struct constraint_node *constraint;
 752         u16 tclass;
 753         int rc = 0;
 754
 755         if (!ss_initialized)
 756                 return 0;
 757
 758         read_lock(&policy_rwlock);
 759
 760         tclass = unmap_class(orig_tclass);
 761
 762         if (!tclass || tclass > policydb.p_classes.nprim) {
 763                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 764                         __func__, tclass);
 765                 rc = -EINVAL;
 766                 goto out;
 767         }
 768         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 769
 770         ocontext = sidtab_search(&sidtab, oldsid);
 771         if (!ocontext) {
 772                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 773                         __func__, oldsid);
 774                 rc = -EINVAL;
 775                 goto out;
 776         }
 777
 778         ncontext = sidtab_search(&sidtab, newsid);
 779         if (!ncontext) {
 780                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 781                         __func__, newsid);
 782                 rc = -EINVAL;
 783                 goto out;
 784         }
 785
 786         tcontext = sidtab_search(&sidtab, tasksid);
 787         if (!tcontext) {
 788                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 789                         __func__, tasksid);
 790                 rc = -EINVAL;
 791                 goto out;
 792         }
 793
 794         constraint = tclass_datum->validatetrans;
 795         while (constraint) {
 796                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 797                                           constraint->expr)) {
 798                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 799                                                              tcontext, tclass);
 800                         goto out;
 801                 }
 802                 constraint = constraint->next;
 803         }
 804
 805 out:
 806         read_unlock(&policy_rwlock);
 807         return rc;
 808 }
 809
 810 /*
 811  * security_bounded_transition - check whether the given
 812  * transition is directed to bounded, or not.
 813  * It returns 0, if @newsid is bounded by @oldsid.
 814  * Otherwise, it returns error code.
 815  *
 816  * @oldsid : current security identifier
 817  * @newsid : destinated security identifier
 818  */
 819 int security_bounded_transition(u32 old_sid, u32 new_sid)
 820 {
 821         struct context *old_context, *new_context;
 822         struct type_datum *type;
 823         int index;
 824         int rc;
 825
 826         read_lock(&policy_rwlock);
 827
 828         rc = -EINVAL;
 829         old_context = sidtab_search(&sidtab, old_sid);
 830         if (!old_context) {
 831                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 832                        __func__, old_sid);
 833                 goto out;
 834         }
 835
 836         rc = -EINVAL;
 837         new_context = sidtab_search(&sidtab, new_sid);
 838         if (!new_context) {
 839                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 840                        __func__, new_sid);
 841                 goto out;
 842         }
 843
 844         rc = 0;
 845         /* type/domain unchanged */
 846         if (old_context->type == new_context->type)
 847                 goto out;
 848
 849         index = new_context->type;
 850         while (true) {
 851                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 852                                           index - 1);
 853                 BUG_ON(!type);
 854
 855                 /* not bounded anymore */
 856                 rc = -EPERM;
 857                 if (!type->bounds)
 858                         break;
 859
 860                 /* @newsid is bounded by @oldsid */
 861                 rc = 0;
 862                 if (type->bounds == old_context->type)
 863                         break;
 864
 865                 index = type->bounds;
 866         }
 867
 868         if (rc) {
 869                 char *old_name = NULL;
 870                 char *new_name = NULL;
 871                 u32 length;
 872
 873                 if (!context_struct_to_string(old_context,
 874                                               &old_name, &length) &&
 875                     !context_struct_to_string(new_context,
 876                                               &new_name, &length)) {
 877                         audit_log(current->audit_context,
 878                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 879                                   "op=security_bounded_transition "
 880                                   "result=denied "
 881                                   "oldcontext=%s newcontext=%s",
 882                                   old_name, new_name);
 883                 }
 884                 kfree(new_name);
 885                 kfree(old_name);
 886         }
 887 out:
 888         read_unlock(&policy_rwlock);
 889
 890         return rc;
 891 }
 892
 893 static void avd_init(struct av_decision *avd)
 894 {
 895         avd->allowed = 0;
 896         avd->auditallow = 0;
 897         avd->auditdeny = 0xffffffff;
 898         avd->seqno = latest_granting;
 899         avd->flags = 0;
 900 }
 901
 902
 903 /**
 904  * security_compute_av - Compute access vector decisions.
 905  * @ssid: source security identifier
 906  * @tsid: target security identifier
 907  * @tclass: target security class
 908  * @avd: access vector decisions
 909  *
 910  * Compute a set of access vector decisions based on the
 911  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 912  */
 913 void security_compute_av(u32 ssid,
 914                          u32 tsid,
 915                          u16 orig_tclass,
 916                          struct av_decision *avd)
 917 {
 918         u16 tclass;
 919         struct context *scontext = NULL, *tcontext = NULL;
 920
 921         read_lock(&policy_rwlock);
 922         avd_init(avd);
 923         if (!ss_initialized)
 924                 goto allow;
 925
 926         scontext = sidtab_search(&sidtab, ssid);
 927         if (!scontext) {
 928                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 929                        __func__, ssid);
 930                 goto out;
 931         }
 932
 933         /* permissive domain? */
 934         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 935                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 936
 937         tcontext = sidtab_search(&sidtab, tsid);
 938         if (!tcontext) {
 939                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 940                        __func__, tsid);
 941                 goto out;
 942         }
 943
 944         tclass = unmap_class(orig_tclass);
 945         if (unlikely(orig_tclass && !tclass)) {
 946                 if (policydb.allow_unknown)
 947                         goto allow;
 948                 goto out;
 949         }
 950         context_struct_compute_av(scontext, tcontext, tclass, avd);
 951         map_decision(orig_tclass, avd, policydb.allow_unknown);
 952 out:
 953         read_unlock(&policy_rwlock);
 954         return;
 955 allow:
 956         avd->allowed = 0xffffffff;
 957         goto out;
 958 }
 959
 960 void security_compute_av_user(u32 ssid,
 961                               u32 tsid,
 962                               u16 tclass,
 963                               struct av_decision *avd)
 964 {
 965         struct context *scontext = NULL, *tcontext = NULL;
 966
 967         read_lock(&policy_rwlock);
 968         avd_init(avd);
 969         if (!ss_initialized)
 970                 goto allow;
 971
 972         scontext = sidtab_search(&sidtab, ssid);
 973         if (!scontext) {
 974                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 975                        __func__, ssid);
 976                 goto out;
 977         }
 978
 979         /* permissive domain? */
 980         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 981                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 982
 983         tcontext = sidtab_search(&sidtab, tsid);
 984         if (!tcontext) {
 985                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 986                        __func__, tsid);
 987                 goto out;
 988         }
 989
 990         if (unlikely(!tclass)) {
 991                 if (policydb.allow_unknown)
 992                         goto allow;
 993                 goto out;
 994         }
 995
 996         context_struct_compute_av(scontext, tcontext, tclass, avd);
 997  out:
 998         read_unlock(&policy_rwlock);
 999         return;
1000 allow:
1001         avd->allowed = 0xffffffff;
1002         goto out;
1003 }
1004
1005 /*
1006  * Write the security context string representation of
1007  * the context structure `context' into a dynamically
1008  * allocated string of the correct size.  Set `*scontext'
1009  * to point to this string and set `*scontext_len' to
1010  * the length of the string.
1011  */
1012 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1013 {
1014         char *scontextp;
1015
1016         if (scontext)
1017                 *scontext = NULL;
1018         *scontext_len = 0;
1019
1020         if (context->len) {
1021                 *scontext_len = context->len;
1022                 if (scontext) {
1023                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1024                         if (!(*scontext))
1025                                 return -ENOMEM;
1026                 }
1027                 return 0;
1028         }
1029
1030         /* Compute the size of the context. */
1031         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1032         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1033         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1034         *scontext_len += mls_compute_context_len(context);
1035
1036         if (!scontext)
1037                 return 0;
1038
1039         /* Allocate space for the context; caller must free this space. */
1040         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1041         if (!scontextp)
1042                 return -ENOMEM;
1043         *scontext = scontextp;
1044
1045         /*
1046          * Copy the user name, role name and type name into the context.
1047          */
1048         sprintf(scontextp, "%s:%s:%s",
1049                 sym_name(&policydb, SYM_USERS, context->user - 1),
1050                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1051                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1052         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1053                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1054                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1055
1056         mls_sid_to_context(context, &scontextp);
1057
1058         *scontextp = 0;
1059
1060         return 0;
1061 }
1062
1063 #include "initial_sid_to_string.h"
1064
1065 const char *security_get_initial_sid_context(u32 sid)
1066 {
1067         if (unlikely(sid > SECINITSID_NUM))
1068                 return NULL;
1069         return initial_sid_to_string[sid];
1070 }
1071
1072 static int security_sid_to_context_core(u32 sid, char **scontext,
1073                                         u32 *scontext_len, int force)
1074 {
1075         struct context *context;
1076         int rc = 0;
1077
1078         if (scontext)
1079                 *scontext = NULL;
1080         *scontext_len  = 0;
1081
1082         if (!ss_initialized) {
1083                 if (sid <= SECINITSID_NUM) {
1084                         char *scontextp;
1085
1086                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1087                         if (!scontext)
1088                                 goto out;
1089                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1090                         if (!scontextp) {
1091                                 rc = -ENOMEM;
1092                                 goto out;
1093                         }
1094                         strcpy(scontextp, initial_sid_to_string[sid]);
1095                         *scontext = scontextp;
1096                         goto out;
1097                 }
1098                 printk(KERN_ERR "SELinux: %s:  called before initial "
1099                        "load_policy on unknown SID %d\n", __func__, sid);
1100                 rc = -EINVAL;
1101                 goto out;
1102         }
1103         read_lock(&policy_rwlock);
1104         if (force)
1105                 context = sidtab_search_force(&sidtab, sid);
1106         else
1107                 context = sidtab_search(&sidtab, sid);
1108         if (!context) {
1109                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1110                         __func__, sid);
1111                 rc = -EINVAL;
1112                 goto out_unlock;
1113         }
1114         rc = context_struct_to_string(context, scontext, scontext_len);
1115 out_unlock:
1116         read_unlock(&policy_rwlock);
1117 out:
1118         return rc;
1119
1120 }
1121
1122 /**
1123  * security_sid_to_context - Obtain a context for a given SID.
1124  * @sid: security identifier, SID
1125  * @scontext: security context
1126  * @scontext_len: length in bytes
1127  *
1128  * Write the string representation of the context associated with @sid
1129  * into a dynamically allocated string of the correct size.  Set @scontext
1130  * to point to this string and set @scontext_len to the length of the string.
1131  */
1132 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1133 {
1134         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1135 }
1136
1137 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1138 {
1139         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1140 }
1141
1142 /*
1143  * Caveat:  Mutates scontext.
1144  */
1145 static int string_to_context_struct(struct policydb *pol,
1146                                     struct sidtab *sidtabp,
1147                                     char *scontext,
1148                                     u32 scontext_len,
1149                                     struct context *ctx,
1150                                     u32 def_sid)
1151 {
1152         struct role_datum *role;
1153         struct type_datum *typdatum;
1154         struct user_datum *usrdatum;
1155         char *scontextp, *p, oldc;
1156         int rc = 0;
1157
1158         context_init(ctx);
1159
1160         /* Parse the security context. */
1161
1162         rc = -EINVAL;
1163         scontextp = (char *) scontext;
1164
1165         /* Extract the user. */
1166         p = scontextp;
1167         while (*p && *p != ':')
1168                 p++;
1169
1170         if (*p == 0)
1171                 goto out;
1172
1173         *p++ = 0;
1174
1175         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1176         if (!usrdatum)
1177                 goto out;
1178
1179         ctx->user = usrdatum->value;
1180
1181         /* Extract role. */
1182         scontextp = p;
1183         while (*p && *p != ':')
1184                 p++;
1185
1186         if (*p == 0)
1187                 goto out;
1188
1189         *p++ = 0;
1190
1191         role = hashtab_search(pol->p_roles.table, scontextp);
1192         if (!role)
1193                 goto out;
1194         ctx->role = role->value;
1195
1196         /* Extract type. */
1197         scontextp = p;
1198         while (*p && *p != ':')
1199                 p++;
1200         oldc = *p;
1201         *p++ = 0;
1202
1203         typdatum = hashtab_search(pol->p_types.table, scontextp);
1204         if (!typdatum || typdatum->attribute)
1205                 goto out;
1206
1207         ctx->type = typdatum->value;
1208
1209         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1210         if (rc)
1211                 goto out;
1212
1213         rc = -EINVAL;
1214         if ((p - scontext) < scontext_len)
1215                 goto out;
1216
1217         /* Check the validity of the new context. */
1218         if (!policydb_context_isvalid(pol, ctx))
1219                 goto out;
1220         rc = 0;
1221 out:
1222         if (rc)
1223                 context_destroy(ctx);
1224         return rc;
1225 }
1226
1227 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1228                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1229                                         int force)
1230 {
1231         char *scontext2, *str = NULL;
1232         struct context context;
1233         int rc = 0;
1234
1235         /* An empty security context is never valid. */
1236         if (!scontext_len)
1237                 return -EINVAL;
1238
1239         if (!ss_initialized) {
1240                 int i;
1241
1242                 for (i = 1; i < SECINITSID_NUM; i++) {
1243                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1244                                 *sid = i;
1245                                 return 0;
1246                         }
1247                 }
1248                 *sid = SECINITSID_KERNEL;
1249                 return 0;
1250         }
1251         *sid = SECSID_NULL;
1252
1253         /* Copy the string so that we can modify the copy as we parse it. */
1254         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1255         if (!scontext2)
1256                 return -ENOMEM;
1257         memcpy(scontext2, scontext, scontext_len);
1258         scontext2[scontext_len] = 0;
1259
1260         if (force) {
1261                 /* Save another copy for storing in uninterpreted form */
1262                 rc = -ENOMEM;
1263                 str = kstrdup(scontext2, gfp_flags);
1264                 if (!str)
1265                         goto out;
1266         }
1267
1268         read_lock(&policy_rwlock);
1269         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1270                                       scontext_len, &context, def_sid);
1271         if (rc == -EINVAL && force) {
1272                 context.str = str;
1273                 context.len = scontext_len;
1274                 str = NULL;
1275         } else if (rc)
1276                 goto out_unlock;
1277         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1278         context_destroy(&context);
1279 out_unlock:
1280         read_unlock(&policy_rwlock);
1281 out:
1282         kfree(scontext2);
1283         kfree(str);
1284         return rc;
1285 }
1286
1287 /**
1288  * security_context_to_sid - Obtain a SID for a given security context.
1289  * @scontext: security context
1290  * @scontext_len: length in bytes
1291  * @sid: security identifier, SID
1292  *
1293  * Obtains a SID associated with the security context that
1294  * has the string representation specified by @scontext.
1295  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1296  * memory is available, or 0 on success.
1297  */
1298 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1299 {
1300         return security_context_to_sid_core(scontext, scontext_len,
1301                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1302 }
1303
1304 /**
1305  * security_context_to_sid_default - Obtain a SID for a given security context,
1306  * falling back to specified default if needed.
1307  *
1308  * @scontext: security context
1309  * @scontext_len: length in bytes
1310  * @sid: security identifier, SID
1311  * @def_sid: default SID to assign on error
1312  *
1313  * Obtains a SID associated with the security context that
1314  * has the string representation specified by @scontext.
1315  * The default SID is passed to the MLS layer to be used to allow
1316  * kernel labeling of the MLS field if the MLS field is not present
1317  * (for upgrading to MLS without full relabel).
1318  * Implicitly forces adding of the context even if it cannot be mapped yet.
1319  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1320  * memory is available, or 0 on success.
1321  */
1322 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1323                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1324 {
1325         return security_context_to_sid_core(scontext, scontext_len,
1326                                             sid, def_sid, gfp_flags, 1);
1327 }
1328
1329 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1330                                   u32 *sid)
1331 {
1332         return security_context_to_sid_core(scontext, scontext_len,
1333                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1334 }
1335
1336 static int compute_sid_handle_invalid_context(
1337         struct context *scontext,
1338         struct context *tcontext,
1339         u16 tclass,
1340         struct context *newcontext)
1341 {
1342         char *s = NULL, *t = NULL, *n = NULL;
1343         u32 slen, tlen, nlen;
1344
1345         if (context_struct_to_string(scontext, &s, &slen))
1346                 goto out;
1347         if (context_struct_to_string(tcontext, &t, &tlen))
1348                 goto out;
1349         if (context_struct_to_string(newcontext, &n, &nlen))
1350                 goto out;
1351         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1352                   "security_compute_sid:  invalid context %s"
1353                   " for scontext=%s"
1354                   " tcontext=%s"
1355                   " tclass=%s",
1356                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1357 out:
1358         kfree(s);
1359         kfree(t);
1360         kfree(n);
1361         if (!selinux_enforcing)
1362                 return 0;
1363         return -EACCES;
1364 }
1365
1366 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1367                                   u32 stype, u32 ttype, u16 tclass,
1368                                   const char *objname)
1369 {
1370         struct filename_trans ft;
1371         struct filename_trans_datum *otype;
1372
1373         /*
1374          * Most filename trans rules are going to live in specific directories
1375          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1376          * if the ttype does not contain any rules.
1377          */
1378         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1379                 return;
1380
1381         ft.stype = stype;
1382         ft.ttype = ttype;
1383         ft.tclass = tclass;
1384         ft.name = objname;
1385
1386         otype = hashtab_search(p->filename_trans, &ft);
1387         if (otype)
1388                 newcontext->type = otype->otype;
1389 }
1390
1391 static int security_compute_sid(u32 ssid,
1392                                 u32 tsid,
1393                                 u16 orig_tclass,
1394                                 u32 specified,
1395                                 const char *objname,
1396                                 u32 *out_sid,
1397                                 bool kern)
1398 {
1399         struct class_datum *cladatum = NULL;
1400         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1401         struct role_trans *roletr = NULL;
1402         struct avtab_key avkey;
1403         struct avtab_datum *avdatum;
1404         struct avtab_node *node;
1405         u16 tclass;
1406         int rc = 0;
1407         bool sock;
1408
1409         if (!ss_initialized) {
1410                 switch (orig_tclass) {
1411                 case SECCLASS_PROCESS: /* kernel value */
1412                         *out_sid = ssid;
1413                         break;
1414                 default:
1415                         *out_sid = tsid;
1416                         break;
1417                 }
1418                 goto out;
1419         }
1420
1421         context_init(&newcontext);
1422
1423         read_lock(&policy_rwlock);
1424
1425         if (kern) {
1426                 tclass = unmap_class(orig_tclass);
1427                 sock = security_is_socket_class(orig_tclass);
1428         } else {
1429                 tclass = orig_tclass;
1430                 sock = security_is_socket_class(map_class(tclass));
1431         }
1432
1433         scontext = sidtab_search(&sidtab, ssid);
1434         if (!scontext) {
1435                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1436                        __func__, ssid);
1437                 rc = -EINVAL;
1438                 goto out_unlock;
1439         }
1440         tcontext = sidtab_search(&sidtab, tsid);
1441         if (!tcontext) {
1442                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1443                        __func__, tsid);
1444                 rc = -EINVAL;
1445                 goto out_unlock;
1446         }
1447
1448         if (tclass && tclass <= policydb.p_classes.nprim)
1449                 cladatum = policydb.class_val_to_struct[tclass - 1];
1450
1451         /* Set the user identity. */
1452         switch (specified) {
1453         case AVTAB_TRANSITION:
1454         case AVTAB_CHANGE:
1455                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1456                         newcontext.user = tcontext->user;
1457                 } else {
1458                         /* notice this gets both DEFAULT_SOURCE and unset */
1459                         /* Use the process user identity. */
1460                         newcontext.user = scontext->user;
1461                 }
1462                 break;
1463         case AVTAB_MEMBER:
1464                 /* Use the related object owner. */
1465                 newcontext.user = tcontext->user;
1466                 break;
1467         }
1468
1469         /* Set the role to default values. */
1470         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1471                 newcontext.role = scontext->role;
1472         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1473                 newcontext.role = tcontext->role;
1474         } else {
1475                 if ((tclass == policydb.process_class) || (sock == true))
1476                         newcontext.role = scontext->role;
1477                 else
1478                         newcontext.role = OBJECT_R_VAL;
1479         }
1480
1481         /* Set the type to default values. */
1482         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1483                 newcontext.type = scontext->type;
1484         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1485                 newcontext.type = tcontext->type;
1486         } else {
1487                 if ((tclass == policydb.process_class) || (sock == true)) {
1488                         /* Use the type of process. */
1489                         newcontext.type = scontext->type;
1490                 } else {
1491                         /* Use the type of the related object. */
1492                         newcontext.type = tcontext->type;
1493                 }
1494         }
1495
1496         /* Look for a type transition/member/change rule. */
1497         avkey.source_type = scontext->type;
1498         avkey.target_type = tcontext->type;
1499         avkey.target_class = tclass;
1500         avkey.specified = specified;
1501         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1502
1503         /* If no permanent rule, also check for enabled conditional rules */
1504         if (!avdatum) {
1505                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1506                 for (; node; node = avtab_search_node_next(node, specified)) {
1507                         if (node->key.specified & AVTAB_ENABLED) {
1508                                 avdatum = &node->datum;
1509                                 break;
1510                         }
1511                 }
1512         }
1513
1514         if (avdatum) {
1515                 /* Use the type from the type transition/member/change rule. */
1516                 newcontext.type = avdatum->data;
1517         }
1518
1519         /* if we have a objname this is a file trans check so check those rules */
1520         if (objname)
1521                 filename_compute_type(&policydb, &newcontext, scontext->type,
1522                                       tcontext->type, tclass, objname);
1523
1524         /* Check for class-specific changes. */
1525         if (specified & AVTAB_TRANSITION) {
1526                 /* Look for a role transition rule. */
1527                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1528                         if ((roletr->role == scontext->role) &&
1529                             (roletr->type == tcontext->type) &&
1530                             (roletr->tclass == tclass)) {
1531                                 /* Use the role transition rule. */
1532                                 newcontext.role = roletr->new_role;
1533                                 break;
1534                         }
1535                 }
1536         }
1537
1538         /* Set the MLS attributes.
1539            This is done last because it may allocate memory. */
1540         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1541                              &newcontext, sock);
1542         if (rc)
1543                 goto out_unlock;
1544
1545         /* Check the validity of the context. */
1546         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1547                 rc = compute_sid_handle_invalid_context(scontext,
1548                                                         tcontext,
1549                                                         tclass,
1550                                                         &newcontext);
1551                 if (rc)
1552                         goto out_unlock;
1553         }
1554         /* Obtain the sid for the context. */
1555         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1556 out_unlock:
1557         read_unlock(&policy_rwlock);
1558         context_destroy(&newcontext);
1559 out:
1560         return rc;
1561 }
1562
1563 /**
1564  * security_transition_sid - Compute the SID for a new subject/object.
1565  * @ssid: source security identifier
1566  * @tsid: target security identifier
1567  * @tclass: target security class
1568  * @out_sid: security identifier for new subject/object
1569  *
1570  * Compute a SID to use for labeling a new subject or object in the
1571  * class @tclass based on a SID pair (@ssid, @tsid).
1572  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1573  * if insufficient memory is available, or %0 if the new SID was
1574  * computed successfully.
1575  */
1576 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1577                             const struct qstr *qstr, u32 *out_sid)
1578 {
1579         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1580                                     qstr ? qstr->name : NULL, out_sid, true);
1581 }
1582
1583 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1584                                  const char *objname, u32 *out_sid)
1585 {
1586         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1587                                     objname, out_sid, false);
1588 }
1589
1590 /**
1591  * security_member_sid - Compute the SID for member selection.
1592  * @ssid: source security identifier
1593  * @tsid: target security identifier
1594  * @tclass: target security class
1595  * @out_sid: security identifier for selected member
1596  *
1597  * Compute a SID to use when selecting a member of a polyinstantiated
1598  * object of class @tclass based on a SID pair (@ssid, @tsid).
1599  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1600  * if insufficient memory is available, or %0 if the SID was
1601  * computed successfully.
1602  */
1603 int security_member_sid(u32 ssid,
1604                         u32 tsid,
1605                         u16 tclass,
1606                         u32 *out_sid)
1607 {
1608         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1609                                     out_sid, false);
1610 }
1611
1612 /**
1613  * security_change_sid - Compute the SID for object relabeling.
1614  * @ssid: source security identifier
1615  * @tsid: target security identifier
1616  * @tclass: target security class
1617  * @out_sid: security identifier for selected member
1618  *
1619  * Compute a SID to use for relabeling an object of class @tclass
1620  * based on a SID pair (@ssid, @tsid).
1621  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1622  * if insufficient memory is available, or %0 if the SID was
1623  * computed successfully.
1624  */
1625 int security_change_sid(u32 ssid,
1626                         u32 tsid,
1627                         u16 tclass,
1628                         u32 *out_sid)
1629 {
1630         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1631                                     out_sid, false);
1632 }
1633
1634 /* Clone the SID into the new SID table. */
1635 static int clone_sid(u32 sid,
1636                      struct context *context,
1637                      void *arg)
1638 {
1639         struct sidtab *s = arg;
1640
1641         if (sid > SECINITSID_NUM)
1642                 return sidtab_insert(s, sid, context);
1643         else
1644                 return 0;
1645 }
1646
1647 static inline int convert_context_handle_invalid_context(struct context *context)
1648 {
1649         char *s;
1650         u32 len;
1651
1652         if (selinux_enforcing)
1653                 return -EINVAL;
1654
1655         if (!context_struct_to_string(context, &s, &len)) {
1656                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1657                 kfree(s);
1658         }
1659         return 0;
1660 }
1661
1662 struct convert_context_args {
1663         struct policydb *oldp;
1664         struct policydb *newp;
1665 };
1666
1667 /*
1668  * Convert the values in the security context
1669  * structure `c' from the values specified
1670  * in the policy `p->oldp' to the values specified
1671  * in the policy `p->newp'.  Verify that the
1672  * context is valid under the new policy.
1673  */
1674 static int convert_context(u32 key,
1675                            struct context *c,
1676                            void *p)
1677 {
1678         struct convert_context_args *args;
1679         struct context oldc;
1680         struct ocontext *oc;
1681         struct mls_range *range;
1682         struct role_datum *role;
1683         struct type_datum *typdatum;
1684         struct user_datum *usrdatum;
1685         char *s;
1686         u32 len;
1687         int rc = 0;
1688
1689         if (key <= SECINITSID_NUM)
1690                 goto out;
1691
1692         args = p;
1693
1694         if (c->str) {
1695                 struct context ctx;
1696
1697                 rc = -ENOMEM;
1698                 s = kstrdup(c->str, GFP_KERNEL);
1699                 if (!s)
1700                         goto out;
1701
1702                 rc = string_to_context_struct(args->newp, NULL, s,
1703                                               c->len, &ctx, SECSID_NULL);
1704                 kfree(s);
1705                 if (!rc) {
1706                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1707                                c->str);
1708                         /* Replace string with mapped representation. */
1709                         kfree(c->str);
1710                         memcpy(c, &ctx, sizeof(*c));
1711                         goto out;
1712                 } else if (rc == -EINVAL) {
1713                         /* Retain string representation for later mapping. */
1714                         rc = 0;
1715                         goto out;
1716                 } else {
1717                         /* Other error condition, e.g. ENOMEM. */
1718                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1719                                c->str, -rc);
1720                         goto out;
1721                 }
1722         }
1723
1724         rc = context_cpy(&oldc, c);
1725         if (rc)
1726                 goto out;
1727
1728         /* Convert the user. */
1729         rc = -EINVAL;
1730         usrdatum = hashtab_search(args->newp->p_users.table,
1731                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1732         if (!usrdatum)
1733                 goto bad;
1734         c->user = usrdatum->value;
1735
1736         /* Convert the role. */
1737         rc = -EINVAL;
1738         role = hashtab_search(args->newp->p_roles.table,
1739                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1740         if (!role)
1741                 goto bad;
1742         c->role = role->value;
1743
1744         /* Convert the type. */
1745         rc = -EINVAL;
1746         typdatum = hashtab_search(args->newp->p_types.table,
1747                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1748         if (!typdatum)
1749                 goto bad;
1750         c->type = typdatum->value;
1751
1752         /* Convert the MLS fields if dealing with MLS policies */
1753         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1754                 rc = mls_convert_context(args->oldp, args->newp, c);
1755                 if (rc)
1756                         goto bad;
1757         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1758                 /*
1759                  * Switching between MLS and non-MLS policy:
1760                  * free any storage used by the MLS fields in the
1761                  * context for all existing entries in the sidtab.
1762                  */
1763                 mls_context_destroy(c);
1764         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1765                 /*
1766                  * Switching between non-MLS and MLS policy:
1767                  * ensure that the MLS fields of the context for all
1768                  * existing entries in the sidtab are filled in with a
1769                  * suitable default value, likely taken from one of the
1770                  * initial SIDs.
1771                  */
1772                 oc = args->newp->ocontexts[OCON_ISID];
1773                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1774                         oc = oc->next;
1775                 rc = -EINVAL;
1776                 if (!oc) {
1777                         printk(KERN_ERR "SELinux:  unable to look up"
1778                                 " the initial SIDs list\n");
1779                         goto bad;
1780                 }
1781                 range = &oc->context[0].range;
1782                 rc = mls_range_set(c, range);
1783                 if (rc)
1784                         goto bad;
1785         }
1786
1787         /* Check the validity of the new context. */
1788         if (!policydb_context_isvalid(args->newp, c)) {
1789                 rc = convert_context_handle_invalid_context(&oldc);
1790                 if (rc)
1791                         goto bad;
1792         }
1793
1794         context_destroy(&oldc);
1795
1796         rc = 0;
1797 out:
1798         return rc;
1799 bad:
1800         /* Map old representation to string and save it. */
1801         rc = context_struct_to_string(&oldc, &s, &len);
1802         if (rc)
1803                 return rc;
1804         context_destroy(&oldc);
1805         context_destroy(c);
1806         c->str = s;
1807         c->len = len;
1808         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1809                c->str);
1810         rc = 0;
1811         goto out;
1812 }
1813
1814 static void security_load_policycaps(void)
1815 {
1816         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1817                                                   POLICYDB_CAPABILITY_NETPEER);
1818         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1819                                                   POLICYDB_CAPABILITY_OPENPERM);
1820         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1821                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1822 }
1823
1824 static int security_preserve_bools(struct policydb *p);
1825
1826 /**
1827  * security_load_policy - Load a security policy configuration.
1828  * @data: binary policy data
1829  * @len: length of data in bytes
1830  *
1831  * Load a new set of security policy configuration data,
1832  * validate it and convert the SID table as necessary.
1833  * This function will flush the access vector cache after
1834  * loading the new policy.
1835  */
1836 int security_load_policy(void *data, size_t len)
1837 {
1838         struct policydb *oldpolicydb, *newpolicydb;
1839         struct sidtab oldsidtab, newsidtab;
1840         struct selinux_mapping *oldmap, *map = NULL;
1841         struct convert_context_args args;
1842         u32 seqno;
1843         u16 map_size;
1844         int rc = 0;
1845         struct policy_file file = { data, len }, *fp = &file;
1846
1847         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
1848         if (!oldpolicydb) {
1849                 rc = -ENOMEM;
1850                 goto out;
1851         }
1852         newpolicydb = oldpolicydb + 1;
1853
1854         if (!ss_initialized) {
1855                 avtab_cache_init();
1856                 rc = policydb_read(&policydb, fp);
1857                 if (rc) {
1858                         avtab_cache_destroy();
1859                         goto out;
1860                 }
1861
1862                 policydb.len = len;
1863                 rc = selinux_set_mapping(&policydb, secclass_map,
1864                                          &current_mapping,
1865                                          &current_mapping_size);
1866                 if (rc) {
1867                         policydb_destroy(&policydb);
1868                         avtab_cache_destroy();
1869                         goto out;
1870                 }
1871
1872                 rc = policydb_load_isids(&policydb, &sidtab);
1873                 if (rc) {
1874                         policydb_destroy(&policydb);
1875                         avtab_cache_destroy();
1876                         goto out;
1877                 }
1878
1879                 security_load_policycaps();
1880                 ss_initialized = 1;
1881                 seqno = ++latest_granting;
1882                 selinux_complete_init();
1883                 avc_ss_reset(seqno);
1884                 selnl_notify_policyload(seqno);
1885                 selinux_status_update_policyload(seqno);
1886                 selinux_netlbl_cache_invalidate();
1887                 selinux_xfrm_notify_policyload();
1888                 goto out;
1889         }
1890
1891 #if 0
1892         sidtab_hash_eval(&sidtab, "sids");
1893 #endif
1894
1895         rc = policydb_read(newpolicydb, fp);
1896         if (rc)
1897                 goto out;
1898
1899         newpolicydb->len = len;
1900         /* If switching between different policy types, log MLS status */
1901         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
1902                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1903         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
1904                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1905
1906         rc = policydb_load_isids(newpolicydb, &newsidtab);
1907         if (rc) {
1908                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1909                 policydb_destroy(newpolicydb);
1910                 goto out;
1911         }
1912
1913         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
1914         if (rc)
1915                 goto err;
1916
1917         rc = security_preserve_bools(newpolicydb);
1918         if (rc) {
1919                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1920                 goto err;
1921         }
1922
1923         /* Clone the SID table. */
1924         sidtab_shutdown(&sidtab);
1925
1926         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1927         if (rc)
1928                 goto err;
1929
1930         /*
1931          * Convert the internal representations of contexts
1932          * in the new SID table.
1933          */
1934         args.oldp = &policydb;
1935         args.newp = newpolicydb;
1936         rc = sidtab_map(&newsidtab, convert_context, &args);
1937         if (rc) {
1938                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1939                         " representation of contexts in the new SID"
1940                         " table\n");
1941                 goto err;
1942         }
1943
1944         /* Save the old policydb and SID table to free later. */
1945         memcpy(oldpolicydb, &policydb, sizeof(policydb));
1946         sidtab_set(&oldsidtab, &sidtab);
1947
1948         /* Install the new policydb and SID table. */
1949         write_lock_irq(&policy_rwlock);
1950         memcpy(&policydb, newpolicydb, sizeof(policydb));
1951         sidtab_set(&sidtab, &newsidtab);
1952         security_load_policycaps();
1953         oldmap = current_mapping;
1954         current_mapping = map;
1955         current_mapping_size = map_size;
1956         seqno = ++latest_granting;
1957         write_unlock_irq(&policy_rwlock);
1958
1959         /* Free the old policydb and SID table. */
1960         policydb_destroy(oldpolicydb);
1961         sidtab_destroy(&oldsidtab);
1962         kfree(oldmap);
1963
1964         avc_ss_reset(seqno);
1965         selnl_notify_policyload(seqno);
1966         selinux_status_update_policyload(seqno);
1967         selinux_netlbl_cache_invalidate();
1968         selinux_xfrm_notify_policyload();
1969
1970         rc = 0;
1971         goto out;
1972
1973 err:
1974         kfree(map);
1975         sidtab_destroy(&newsidtab);
1976         policydb_destroy(newpolicydb);
1977
1978 out:
1979         kfree(oldpolicydb);
1980         return rc;
1981 }
1982
1983 size_t security_policydb_len(void)
1984 {
1985         size_t len;
1986
1987         read_lock(&policy_rwlock);
1988         len = policydb.len;
1989         read_unlock(&policy_rwlock);
1990
1991         return len;
1992 }
1993
1994 /**
1995  * security_port_sid - Obtain the SID for a port.
1996  * @protocol: protocol number
1997  * @port: port number
1998  * @out_sid: security identifier
1999  */
2000 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2001 {
2002         struct ocontext *c;
2003         int rc = 0;
2004
2005         read_lock(&policy_rwlock);
2006
2007         c = policydb.ocontexts[OCON_PORT];
2008         while (c) {
2009                 if (c->u.port.protocol == protocol &&
2010                     c->u.port.low_port <= port &&
2011                     c->u.port.high_port >= port)
2012                         break;
2013                 c = c->next;
2014         }
2015
2016         if (c) {
2017                 if (!c->sid[0]) {
2018                         rc = sidtab_context_to_sid(&sidtab,
2019                                                    &c->context[0],
2020                                                    &c->sid[0]);
2021                         if (rc)
2022                                 goto out;
2023                 }
2024                 *out_sid = c->sid[0];
2025         } else {
2026                 *out_sid = SECINITSID_PORT;
2027         }
2028
2029 out:
2030         read_unlock(&policy_rwlock);
2031         return rc;
2032 }
2033
2034 /**
2035  * security_netif_sid - Obtain the SID for a network interface.
2036  * @name: interface name
2037  * @if_sid: interface SID
2038  */
2039 int security_netif_sid(char *name, u32 *if_sid)
2040 {
2041         int rc = 0;
2042         struct ocontext *c;
2043
2044         read_lock(&policy_rwlock);
2045
2046         c = policydb.ocontexts[OCON_NETIF];
2047         while (c) {
2048                 if (strcmp(name, c->u.name) == 0)
2049                         break;
2050                 c = c->next;
2051         }
2052
2053         if (c) {
2054                 if (!c->sid[0] || !c->sid[1]) {
2055                         rc = sidtab_context_to_sid(&sidtab,
2056                                                   &c->context[0],
2057                                                   &c->sid[0]);
2058                         if (rc)
2059                                 goto out;
2060                         rc = sidtab_context_to_sid(&sidtab,
2061                                                    &c->context[1],
2062                                                    &c->sid[1]);
2063                         if (rc)
2064                                 goto out;
2065                 }
2066                 *if_sid = c->sid[0];
2067         } else
2068                 *if_sid = SECINITSID_NETIF;
2069
2070 out:
2071         read_unlock(&policy_rwlock);
2072         return rc;
2073 }
2074
2075 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2076 {
2077         int i, fail = 0;
2078
2079         for (i = 0; i < 4; i++)
2080                 if (addr[i] != (input[i] & mask[i])) {
2081                         fail = 1;
2082                         break;
2083                 }
2084
2085         return !fail;
2086 }
2087
2088 /**
2089  * security_node_sid - Obtain the SID for a node (host).
2090  * @domain: communication domain aka address family
2091  * @addrp: address
2092  * @addrlen: address length in bytes
2093  * @out_sid: security identifier
2094  */
2095 int security_node_sid(u16 domain,
2096                       void *addrp,
2097                       u32 addrlen,
2098                       u32 *out_sid)
2099 {
2100         int rc;
2101         struct ocontext *c;
2102
2103         read_lock(&policy_rwlock);
2104
2105         switch (domain) {
2106         case AF_INET: {
2107                 u32 addr;
2108
2109                 rc = -EINVAL;
2110                 if (addrlen != sizeof(u32))
2111                         goto out;
2112
2113                 addr = *((u32 *)addrp);
2114
2115                 c = policydb.ocontexts[OCON_NODE];
2116                 while (c) {
2117                         if (c->u.node.addr == (addr & c->u.node.mask))
2118                                 break;
2119                         c = c->next;
2120                 }
2121                 break;
2122         }
2123
2124         case AF_INET6:
2125                 rc = -EINVAL;
2126                 if (addrlen != sizeof(u64) * 2)
2127                         goto out;
2128                 c = policydb.ocontexts[OCON_NODE6];
2129                 while (c) {
2130                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2131                                                 c->u.node6.mask))
2132                                 break;
2133                         c = c->next;
2134                 }
2135                 break;
2136
2137         default:
2138                 rc = 0;
2139                 *out_sid = SECINITSID_NODE;
2140                 goto out;
2141         }
2142
2143         if (c) {
2144                 if (!c->sid[0]) {
2145                         rc = sidtab_context_to_sid(&sidtab,
2146                                                    &c->context[0],
2147                                                    &c->sid[0]);
2148                         if (rc)
2149                                 goto out;
2150                 }
2151                 *out_sid = c->sid[0];
2152         } else {
2153                 *out_sid = SECINITSID_NODE;
2154         }
2155
2156         rc = 0;
2157 out:
2158         read_unlock(&policy_rwlock);
2159         return rc;
2160 }
2161
2162 #define SIDS_NEL 25
2163
2164 /**
2165  * security_get_user_sids - Obtain reachable SIDs for a user.
2166  * @fromsid: starting SID
2167  * @username: username
2168  * @sids: array of reachable SIDs for user
2169  * @nel: number of elements in @sids
2170  *
2171  * Generate the set of SIDs for legal security contexts
2172  * for a given user that can be reached by @fromsid.
2173  * Set *@sids to point to a dynamically allocated
2174  * array containing the set of SIDs.  Set *@nel to the
2175  * number of elements in the array.
2176  */
2177
2178 int security_get_user_sids(u32 fromsid,
2179                            char *username,
2180                            u32 **sids,
2181                            u32 *nel)
2182 {
2183         struct context *fromcon, usercon;
2184         u32 *mysids = NULL, *mysids2, sid;
2185         u32 mynel = 0, maxnel = SIDS_NEL;
2186         struct user_datum *user;
2187         struct role_datum *role;
2188         struct ebitmap_node *rnode, *tnode;
2189         int rc = 0, i, j;
2190
2191         *sids = NULL;
2192         *nel = 0;
2193
2194         if (!ss_initialized)
2195                 goto out;
2196
2197         read_lock(&policy_rwlock);
2198
2199         context_init(&usercon);
2200
2201         rc = -EINVAL;
2202         fromcon = sidtab_search(&sidtab, fromsid);
2203         if (!fromcon)
2204                 goto out_unlock;
2205
2206         rc = -EINVAL;
2207         user = hashtab_search(policydb.p_users.table, username);
2208         if (!user)
2209                 goto out_unlock;
2210
2211         usercon.user = user->value;
2212
2213         rc = -ENOMEM;
2214         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2215         if (!mysids)
2216                 goto out_unlock;
2217
2218         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2219                 role = policydb.role_val_to_struct[i];
2220                 usercon.role = i + 1;
2221                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2222                         usercon.type = j + 1;
2223
2224                         if (mls_setup_user_range(fromcon, user, &usercon))
2225                                 continue;
2226
2227                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2228                         if (rc)
2229                                 goto out_unlock;
2230                         if (mynel < maxnel) {
2231                                 mysids[mynel++] = sid;
2232                         } else {
2233                                 rc = -ENOMEM;
2234                                 maxnel += SIDS_NEL;
2235                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2236                                 if (!mysids2)
2237                                         goto out_unlock;
2238                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2239                                 kfree(mysids);
2240                                 mysids = mysids2;
2241                                 mysids[mynel++] = sid;
2242                         }
2243                 }
2244         }
2245         rc = 0;
2246 out_unlock:
2247         read_unlock(&policy_rwlock);
2248         if (rc || !mynel) {
2249                 kfree(mysids);
2250                 goto out;
2251         }
2252
2253         rc = -ENOMEM;
2254         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2255         if (!mysids2) {
2256                 kfree(mysids);
2257                 goto out;
2258         }
2259         for (i = 0, j = 0; i < mynel; i++) {
2260                 struct av_decision dummy_avd;
2261                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2262                                           SECCLASS_PROCESS, /* kernel value */
2263                                           PROCESS__TRANSITION, AVC_STRICT,
2264                                           &dummy_avd);
2265                 if (!rc)
2266                         mysids2[j++] = mysids[i];
2267                 cond_resched();
2268         }
2269         rc = 0;
2270         kfree(mysids);
2271         *sids = mysids2;
2272         *nel = j;
2273 out:
2274         return rc;
2275 }
2276
2277 /**
2278  * security_genfs_sid - Obtain a SID for a file in a filesystem
2279  * @fstype: filesystem type
2280  * @path: path from root of mount
2281  * @sclass: file security class
2282  * @sid: SID for path
2283  *
2284  * Obtain a SID to use for a file in a filesystem that
2285  * cannot support xattr or use a fixed labeling behavior like
2286  * transition SIDs or task SIDs.
2287  */
2288 int security_genfs_sid(const char *fstype,
2289                        char *path,
2290                        u16 orig_sclass,
2291                        u32 *sid)
2292 {
2293         int len;
2294         u16 sclass;
2295         struct genfs *genfs;
2296         struct ocontext *c;
2297         int rc, cmp = 0;
2298
2299         while (path[0] == '/' && path[1] == '/')
2300                 path++;
2301
2302         read_lock(&policy_rwlock);
2303
2304         sclass = unmap_class(orig_sclass);
2305         *sid = SECINITSID_UNLABELED;
2306
2307         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2308                 cmp = strcmp(fstype, genfs->fstype);
2309                 if (cmp <= 0)
2310                         break;
2311         }
2312
2313         rc = -ENOENT;
2314         if (!genfs || cmp)
2315                 goto out;
2316
2317         for (c = genfs->head; c; c = c->next) {
2318                 len = strlen(c->u.name);
2319                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2320                     (strncmp(c->u.name, path, len) == 0))
2321                         break;
2322         }
2323
2324         rc = -ENOENT;
2325         if (!c)
2326                 goto out;
2327
2328         if (!c->sid[0]) {
2329                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2330                 if (rc)
2331                         goto out;
2332         }
2333
2334         *sid = c->sid[0];
2335         rc = 0;
2336 out:
2337         read_unlock(&policy_rwlock);
2338         return rc;
2339 }
2340
2341 /**
2342  * security_fs_use - Determine how to handle labeling for a filesystem.
2343  * @sb: superblock in question
2344  */
2345 int security_fs_use(struct super_block *sb)
2346 {
2347         int rc = 0;
2348         struct ocontext *c;
2349         struct superblock_security_struct *sbsec = sb->s_security;
2350         const char *fstype = sb->s_type->name;
2351
2352         read_lock(&policy_rwlock);
2353
2354         c = policydb.ocontexts[OCON_FSUSE];
2355         while (c) {
2356                 if (strcmp(fstype, c->u.name) == 0)
2357                         break;
2358                 c = c->next;
2359         }
2360
2361         if (c) {
2362                 sbsec->behavior = c->v.behavior;
2363                 if (!c->sid[0]) {
2364                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2365                                                    &c->sid[0]);
2366                         if (rc)
2367                                 goto out;
2368                 }
2369                 sbsec->sid = c->sid[0];
2370         } else {
2371                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, &sbsec->sid);
2372                 if (rc) {
2373                         sbsec->behavior = SECURITY_FS_USE_NONE;
2374                         rc = 0;
2375                 } else {
2376                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2377                 }
2378         }
2379
2380 out:
2381         read_unlock(&policy_rwlock);
2382         return rc;
2383 }
2384
2385 int security_get_bools(int *len, char ***names, int **values)
2386 {
2387         int i, rc;
2388
2389         read_lock(&policy_rwlock);
2390         *names = NULL;
2391         *values = NULL;
2392
2393         rc = 0;
2394         *len = policydb.p_bools.nprim;
2395         if (!*len)
2396                 goto out;
2397
2398         rc = -ENOMEM;
2399         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2400         if (!*names)
2401                 goto err;
2402
2403         rc = -ENOMEM;
2404         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2405         if (!*values)
2406                 goto err;
2407
2408         for (i = 0; i < *len; i++) {
2409                 size_t name_len;
2410
2411                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2412                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2413
2414                 rc = -ENOMEM;
2415                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2416                 if (!(*names)[i])
2417                         goto err;
2418
2419                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2420                 (*names)[i][name_len - 1] = 0;
2421         }
2422         rc = 0;
2423 out:
2424         read_unlock(&policy_rwlock);
2425         return rc;
2426 err:
2427         if (*names) {
2428                 for (i = 0; i < *len; i++)
2429                         kfree((*names)[i]);
2430         }
2431         kfree(*values);
2432         goto out;
2433 }
2434
2435
2436 int security_set_bools(int len, int *values)
2437 {
2438         int i, rc;
2439         int lenp, seqno = 0;
2440         struct cond_node *cur;
2441
2442         write_lock_irq(&policy_rwlock);
2443
2444         rc = -EFAULT;
2445         lenp = policydb.p_bools.nprim;
2446         if (len != lenp)
2447                 goto out;
2448
2449         for (i = 0; i < len; i++) {
2450                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2451                         audit_log(current->audit_context, GFP_ATOMIC,
2452                                 AUDIT_MAC_CONFIG_CHANGE,
2453                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2454                                 sym_name(&policydb, SYM_BOOLS, i),
2455                                 !!values[i],
2456                                 policydb.bool_val_to_struct[i]->state,
2457                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2458                                 audit_get_sessionid(current));
2459                 }
2460                 if (values[i])
2461                         policydb.bool_val_to_struct[i]->state = 1;
2462                 else
2463                         policydb.bool_val_to_struct[i]->state = 0;
2464         }
2465
2466         for (cur = policydb.cond_list; cur; cur = cur->next) {
2467                 rc = evaluate_cond_node(&policydb, cur);
2468                 if (rc)
2469                         goto out;
2470         }
2471
2472         seqno = ++latest_granting;
2473         rc = 0;
2474 out:
2475         write_unlock_irq(&policy_rwlock);
2476         if (!rc) {
2477                 avc_ss_reset(seqno);
2478                 selnl_notify_policyload(seqno);
2479                 selinux_status_update_policyload(seqno);
2480                 selinux_xfrm_notify_policyload();
2481         }
2482         return rc;
2483 }
2484
2485 int security_get_bool_value(int bool)
2486 {
2487         int rc;
2488         int len;
2489
2490         read_lock(&policy_rwlock);
2491
2492         rc = -EFAULT;
2493         len = policydb.p_bools.nprim;
2494         if (bool >= len)
2495                 goto out;
2496
2497         rc = policydb.bool_val_to_struct[bool]->state;
2498 out:
2499         read_unlock(&policy_rwlock);
2500         return rc;
2501 }
2502
2503 static int security_preserve_bools(struct policydb *p)
2504 {
2505         int rc, nbools = 0, *bvalues = NULL, i;
2506         char **bnames = NULL;
2507         struct cond_bool_datum *booldatum;
2508         struct cond_node *cur;
2509
2510         rc = security_get_bools(&nbools, &bnames, &bvalues);
2511         if (rc)
2512                 goto out;
2513         for (i = 0; i < nbools; i++) {
2514                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2515                 if (booldatum)
2516                         booldatum->state = bvalues[i];
2517         }
2518         for (cur = p->cond_list; cur; cur = cur->next) {
2519                 rc = evaluate_cond_node(p, cur);
2520                 if (rc)
2521                         goto out;
2522         }
2523
2524 out:
2525         if (bnames) {
2526                 for (i = 0; i < nbools; i++)
2527                         kfree(bnames[i]);
2528         }
2529         kfree(bnames);
2530         kfree(bvalues);
2531         return rc;
2532 }
2533
2534 /*
2535  * security_sid_mls_copy() - computes a new sid based on the given
2536  * sid and the mls portion of mls_sid.
2537  */
2538 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2539 {
2540         struct context *context1;
2541         struct context *context2;
2542         struct context newcon;
2543         char *s;
2544         u32 len;
2545         int rc;
2546
2547         rc = 0;
2548         if (!ss_initialized || !policydb.mls_enabled) {
2549                 *new_sid = sid;
2550                 goto out;
2551         }
2552
2553         context_init(&newcon);
2554
2555         read_lock(&policy_rwlock);
2556
2557         rc = -EINVAL;
2558         context1 = sidtab_search(&sidtab, sid);
2559         if (!context1) {
2560                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2561                         __func__, sid);
2562                 goto out_unlock;
2563         }
2564
2565         rc = -EINVAL;
2566         context2 = sidtab_search(&sidtab, mls_sid);
2567         if (!context2) {
2568                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2569                         __func__, mls_sid);
2570                 goto out_unlock;
2571         }
2572
2573         newcon.user = context1->user;
2574         newcon.role = context1->role;
2575         newcon.type = context1->type;
2576         rc = mls_context_cpy(&newcon, context2);
2577         if (rc)
2578                 goto out_unlock;
2579
2580         /* Check the validity of the new context. */
2581         if (!policydb_context_isvalid(&policydb, &newcon)) {
2582                 rc = convert_context_handle_invalid_context(&newcon);
2583                 if (rc) {
2584                         if (!context_struct_to_string(&newcon, &s, &len)) {
2585                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2586                                           "security_sid_mls_copy: invalid context %s", s);
2587                                 kfree(s);
2588                         }
2589                         goto out_unlock;
2590                 }
2591         }
2592
2593         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2594 out_unlock:
2595         read_unlock(&policy_rwlock);
2596         context_destroy(&newcon);
2597 out:
2598         return rc;
2599 }
2600
2601 /**
2602  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2603  * @nlbl_sid: NetLabel SID
2604  * @nlbl_type: NetLabel labeling protocol type
2605  * @xfrm_sid: XFRM SID
2606  *
2607  * Description:
2608  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2609  * resolved into a single SID it is returned via @peer_sid and the function
2610  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2611  * returns a negative value.  A table summarizing the behavior is below:
2612  *
2613  *                                 | function return |      @sid
2614  *   ------------------------------+-----------------+-----------------
2615  *   no peer labels                |        0        |    SECSID_NULL
2616  *   single peer label             |        0        |    <peer_label>
2617  *   multiple, consistent labels   |        0        |    <peer_label>
2618  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2619  *
2620  */
2621 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2622                                  u32 xfrm_sid,
2623                                  u32 *peer_sid)
2624 {
2625         int rc;
2626         struct context *nlbl_ctx;
2627         struct context *xfrm_ctx;
2628
2629         *peer_sid = SECSID_NULL;
2630
2631         /* handle the common (which also happens to be the set of easy) cases
2632          * right away, these two if statements catch everything involving a
2633          * single or absent peer SID/label */
2634         if (xfrm_sid == SECSID_NULL) {
2635                 *peer_sid = nlbl_sid;
2636                 return 0;
2637         }
2638         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2639          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2640          * is present */
2641         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2642                 *peer_sid = xfrm_sid;
2643                 return 0;
2644         }
2645
2646         /* we don't need to check ss_initialized here since the only way both
2647          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2648          * security server was initialized and ss_initialized was true */
2649         if (!policydb.mls_enabled)
2650                 return 0;
2651
2652         read_lock(&policy_rwlock);
2653
2654         rc = -EINVAL;
2655         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2656         if (!nlbl_ctx) {
2657                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2658                        __func__, nlbl_sid);
2659                 goto out;
2660         }
2661         rc = -EINVAL;
2662         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2663         if (!xfrm_ctx) {
2664                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2665                        __func__, xfrm_sid);
2666                 goto out;
2667         }
2668         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2669         if (rc)
2670                 goto out;
2671
2672         /* at present NetLabel SIDs/labels really only carry MLS
2673          * information so if the MLS portion of the NetLabel SID
2674          * matches the MLS portion of the labeled XFRM SID/label
2675          * then pass along the XFRM SID as it is the most
2676          * expressive */
2677         *peer_sid = xfrm_sid;
2678 out:
2679         read_unlock(&policy_rwlock);
2680         return rc;
2681 }
2682
2683 static int get_classes_callback(void *k, void *d, void *args)
2684 {
2685         struct class_datum *datum = d;
2686         char *name = k, **classes = args;
2687         int value = datum->value - 1;
2688
2689         classes[value] = kstrdup(name, GFP_ATOMIC);
2690         if (!classes[value])
2691                 return -ENOMEM;
2692
2693         return 0;
2694 }
2695
2696 int security_get_classes(char ***classes, int *nclasses)
2697 {
2698         int rc;
2699
2700         read_lock(&policy_rwlock);
2701
2702         rc = -ENOMEM;
2703         *nclasses = policydb.p_classes.nprim;
2704         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2705         if (!*classes)
2706                 goto out;
2707
2708         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2709                         *classes);
2710         if (rc) {
2711                 int i;
2712                 for (i = 0; i < *nclasses; i++)
2713                         kfree((*classes)[i]);
2714                 kfree(*classes);
2715         }
2716
2717 out:
2718         read_unlock(&policy_rwlock);
2719         return rc;
2720 }
2721
2722 static int get_permissions_callback(void *k, void *d, void *args)
2723 {
2724         struct perm_datum *datum = d;
2725         char *name = k, **perms = args;
2726         int value = datum->value - 1;
2727
2728         perms[value] = kstrdup(name, GFP_ATOMIC);
2729         if (!perms[value])
2730                 return -ENOMEM;
2731
2732         return 0;
2733 }
2734
2735 int security_get_permissions(char *class, char ***perms, int *nperms)
2736 {
2737         int rc, i;
2738         struct class_datum *match;
2739
2740         read_lock(&policy_rwlock);
2741
2742         rc = -EINVAL;
2743         match = hashtab_search(policydb.p_classes.table, class);
2744         if (!match) {
2745                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2746                         __func__, class);
2747                 goto out;
2748         }
2749
2750         rc = -ENOMEM;
2751         *nperms = match->permissions.nprim;
2752         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2753         if (!*perms)
2754                 goto out;
2755
2756         if (match->comdatum) {
2757                 rc = hashtab_map(match->comdatum->permissions.table,
2758                                 get_permissions_callback, *perms);
2759                 if (rc)
2760                         goto err;
2761         }
2762
2763         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2764                         *perms);
2765         if (rc)
2766                 goto err;
2767
2768 out:
2769         read_unlock(&policy_rwlock);
2770         return rc;
2771
2772 err:
2773         read_unlock(&policy_rwlock);
2774         for (i = 0; i < *nperms; i++)
2775                 kfree((*perms)[i]);
2776         kfree(*perms);
2777         return rc;
2778 }
2779
2780 int security_get_reject_unknown(void)
2781 {
2782         return policydb.reject_unknown;
2783 }
2784
2785 int security_get_allow_unknown(void)
2786 {
2787         return policydb.allow_unknown;
2788 }
2789
2790 /**
2791  * security_policycap_supported - Check for a specific policy capability
2792  * @req_cap: capability
2793  *
2794  * Description:
2795  * This function queries the currently loaded policy to see if it supports the
2796  * capability specified by @req_cap.  Returns true (1) if the capability is
2797  * supported, false (0) if it isn't supported.
2798  *
2799  */
2800 int security_policycap_supported(unsigned int req_cap)
2801 {
2802         int rc;
2803
2804         read_lock(&policy_rwlock);
2805         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2806         read_unlock(&policy_rwlock);
2807
2808         return rc;
2809 }
2810
2811 struct selinux_audit_rule {
2812         u32 au_seqno;
2813         struct context au_ctxt;
2814 };
2815
2816 void selinux_audit_rule_free(void *vrule)
2817 {
2818         struct selinux_audit_rule *rule = vrule;
2819
2820         if (rule) {
2821                 context_destroy(&rule->au_ctxt);
2822                 kfree(rule);
2823         }
2824 }
2825
2826 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2827 {
2828         struct selinux_audit_rule *tmprule;
2829         struct role_datum *roledatum;
2830         struct type_datum *typedatum;
2831         struct user_datum *userdatum;
2832         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2833         int rc = 0;
2834
2835         *rule = NULL;
2836
2837         if (!ss_initialized)
2838                 return -EOPNOTSUPP;
2839
2840         switch (field) {
2841         case AUDIT_SUBJ_USER:
2842         case AUDIT_SUBJ_ROLE:
2843         case AUDIT_SUBJ_TYPE:
2844         case AUDIT_OBJ_USER:
2845         case AUDIT_OBJ_ROLE:
2846         case AUDIT_OBJ_TYPE:
2847                 /* only 'equals' and 'not equals' fit user, role, and type */
2848                 if (op != Audit_equal && op != Audit_not_equal)
2849                         return -EINVAL;
2850                 break;
2851         case AUDIT_SUBJ_SEN:
2852         case AUDIT_SUBJ_CLR:
2853         case AUDIT_OBJ_LEV_LOW:
2854         case AUDIT_OBJ_LEV_HIGH:
2855                 /* we do not allow a range, indicated by the presence of '-' */
2856                 if (strchr(rulestr, '-'))
2857                         return -EINVAL;
2858                 break;
2859         default:
2860                 /* only the above fields are valid */
2861                 return -EINVAL;
2862         }
2863
2864         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2865         if (!tmprule)
2866                 return -ENOMEM;
2867
2868         context_init(&tmprule->au_ctxt);
2869
2870         read_lock(&policy_rwlock);
2871
2872         tmprule->au_seqno = latest_granting;
2873
2874         switch (field) {
2875         case AUDIT_SUBJ_USER:
2876         case AUDIT_OBJ_USER:
2877                 rc = -EINVAL;
2878                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2879                 if (!userdatum)
2880                         goto out;
2881                 tmprule->au_ctxt.user = userdatum->value;
2882                 break;
2883         case AUDIT_SUBJ_ROLE:
2884         case AUDIT_OBJ_ROLE:
2885                 rc = -EINVAL;
2886                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2887                 if (!roledatum)
2888                         goto out;
2889                 tmprule->au_ctxt.role = roledatum->value;
2890                 break;
2891         case AUDIT_SUBJ_TYPE:
2892         case AUDIT_OBJ_TYPE:
2893                 rc = -EINVAL;
2894                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2895                 if (!typedatum)
2896                         goto out;
2897                 tmprule->au_ctxt.type = typedatum->value;
2898                 break;
2899         case AUDIT_SUBJ_SEN:
2900         case AUDIT_SUBJ_CLR:
2901         case AUDIT_OBJ_LEV_LOW:
2902         case AUDIT_OBJ_LEV_HIGH:
2903                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2904                 if (rc)
2905                         goto out;
2906                 break;
2907         }
2908         rc = 0;
2909 out:
2910         read_unlock(&policy_rwlock);
2911
2912         if (rc) {
2913                 selinux_audit_rule_free(tmprule);
2914                 tmprule = NULL;
2915         }
2916
2917         *rule = tmprule;
2918
2919         return rc;
2920 }
2921
2922 /* Check to see if the rule contains any selinux fields */
2923 int selinux_audit_rule_known(struct audit_krule *rule)
2924 {
2925         int i;
2926
2927         for (i = 0; i < rule->field_count; i++) {
2928                 struct audit_field *f = &rule->fields[i];
2929                 switch (f->type) {
2930                 case AUDIT_SUBJ_USER:
2931                 case AUDIT_SUBJ_ROLE:
2932                 case AUDIT_SUBJ_TYPE:
2933                 case AUDIT_SUBJ_SEN:
2934                 case AUDIT_SUBJ_CLR:
2935                 case AUDIT_OBJ_USER:
2936                 case AUDIT_OBJ_ROLE:
2937                 case AUDIT_OBJ_TYPE:
2938                 case AUDIT_OBJ_LEV_LOW:
2939                 case AUDIT_OBJ_LEV_HIGH:
2940                         return 1;
2941                 }
2942         }
2943
2944         return 0;
2945 }
2946
2947 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2948                              struct audit_context *actx)
2949 {
2950         struct context *ctxt;
2951         struct mls_level *level;
2952         struct selinux_audit_rule *rule = vrule;
2953         int match = 0;
2954
2955         if (unlikely(!rule)) {
2956                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
2957                 return -ENOENT;
2958         }
2959
2960         read_lock(&policy_rwlock);
2961
2962         if (rule->au_seqno < latest_granting) {
2963                 match = -ESTALE;
2964                 goto out;
2965         }
2966
2967         ctxt = sidtab_search(&sidtab, sid);
2968         if (unlikely(!ctxt)) {
2969                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
2970                           sid);
2971                 match = -ENOENT;
2972                 goto out;
2973         }
2974
2975         /* a field/op pair that is not caught here will simply fall through
2976            without a match */
2977         switch (field) {
2978         case AUDIT_SUBJ_USER:
2979         case AUDIT_OBJ_USER:
2980                 switch (op) {
2981                 case Audit_equal:
2982                         match = (ctxt->user == rule->au_ctxt.user);
2983                         break;
2984                 case Audit_not_equal:
2985                         match = (ctxt->user != rule->au_ctxt.user);
2986                         break;
2987                 }
2988                 break;
2989         case AUDIT_SUBJ_ROLE:
2990         case AUDIT_OBJ_ROLE:
2991                 switch (op) {
2992                 case Audit_equal:
2993                         match = (ctxt->role == rule->au_ctxt.role);
2994                         break;
2995                 case Audit_not_equal:
2996                         match = (ctxt->role != rule->au_ctxt.role);
2997                         break;
2998                 }
2999                 break;
3000         case AUDIT_SUBJ_TYPE:
3001         case AUDIT_OBJ_TYPE:
3002                 switch (op) {
3003                 case Audit_equal:
3004                         match = (ctxt->type == rule->au_ctxt.type);
3005                         break;
3006                 case Audit_not_equal:
3007                         match = (ctxt->type != rule->au_ctxt.type);
3008                         break;
3009                 }
3010                 break;
3011         case AUDIT_SUBJ_SEN:
3012         case AUDIT_SUBJ_CLR:
3013         case AUDIT_OBJ_LEV_LOW:
3014         case AUDIT_OBJ_LEV_HIGH:
3015                 level = ((field == AUDIT_SUBJ_SEN ||
3016                           field == AUDIT_OBJ_LEV_LOW) ?
3017                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3018                 switch (op) {
3019                 case Audit_equal:
3020                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3021                                              level);
3022                         break;
3023                 case Audit_not_equal:
3024                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3025                                               level);
3026                         break;
3027                 case Audit_lt:
3028                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3029                                                level) &&
3030                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3031                                                level));
3032                         break;
3033                 case Audit_le:
3034                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3035                                               level);
3036                         break;
3037                 case Audit_gt:
3038                         match = (mls_level_dom(level,
3039                                               &rule->au_ctxt.range.level[0]) &&
3040                                  !mls_level_eq(level,
3041                                                &rule->au_ctxt.range.level[0]));
3042                         break;
3043                 case Audit_ge:
3044                         match = mls_level_dom(level,
3045                                               &rule->au_ctxt.range.level[0]);
3046                         break;
3047                 }
3048         }
3049
3050 out:
3051         read_unlock(&policy_rwlock);
3052         return match;
3053 }
3054
3055 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3056
3057 static int aurule_avc_callback(u32 event)
3058 {
3059         int err = 0;
3060
3061         if (event == AVC_CALLBACK_RESET && aurule_callback)
3062                 err = aurule_callback();
3063         return err;
3064 }
3065
3066 static int __init aurule_init(void)
3067 {
3068         int err;
3069
3070         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3071         if (err)
3072                 panic("avc_add_callback() failed, error %d\n", err);
3073
3074         return err;
3075 }
3076 __initcall(aurule_init);
3077
3078 #ifdef CONFIG_NETLABEL
3079 /**
3080  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3081  * @secattr: the NetLabel packet security attributes
3082  * @sid: the SELinux SID
3083  *
3084  * Description:
3085  * Attempt to cache the context in @ctx, which was derived from the packet in
3086  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3087  * already been initialized.
3088  *
3089  */
3090 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3091                                       u32 sid)
3092 {
3093         u32 *sid_cache;
3094
3095         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3096         if (sid_cache == NULL)
3097                 return;
3098         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3099         if (secattr->cache == NULL) {
3100                 kfree(sid_cache);
3101                 return;
3102         }
3103
3104         *sid_cache = sid;
3105         secattr->cache->free = kfree;
3106         secattr->cache->data = sid_cache;
3107         secattr->flags |= NETLBL_SECATTR_CACHE;
3108 }
3109
3110 /**
3111  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3112  * @secattr: the NetLabel packet security attributes
3113  * @sid: the SELinux SID
3114  *
3115  * Description:
3116  * Convert the given NetLabel security attributes in @secattr into a
3117  * SELinux SID.  If the @secattr field does not contain a full SELinux
3118  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3119  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3120  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3121  * conversion for future lookups.  Returns zero on success, negative values on
3122  * failure.
3123  *
3124  */
3125 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3126                                    u32 *sid)
3127 {
3128         int rc;
3129         struct context *ctx;
3130         struct context ctx_new;
3131
3132         if (!ss_initialized) {
3133                 *sid = SECSID_NULL;
3134                 return 0;
3135         }
3136
3137         read_lock(&policy_rwlock);
3138
3139         if (secattr->flags & NETLBL_SECATTR_CACHE)
3140                 *sid = *(u32 *)secattr->cache->data;
3141         else if (secattr->flags & NETLBL_SECATTR_SECID)
3142                 *sid = secattr->attr.secid;
3143         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3144                 rc = -EIDRM;
3145                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3146                 if (ctx == NULL)
3147                         goto out;
3148
3149                 context_init(&ctx_new);
3150                 ctx_new.user = ctx->user;
3151                 ctx_new.role = ctx->role;
3152                 ctx_new.type = ctx->type;
3153                 mls_import_netlbl_lvl(&ctx_new, secattr);
3154                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3155                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3156                                                    secattr->attr.mls.cat);
3157                         if (rc)
3158                                 goto out;
3159                         memcpy(&ctx_new.range.level[1].cat,
3160                                &ctx_new.range.level[0].cat,
3161                                sizeof(ctx_new.range.level[0].cat));
3162                 }
3163                 rc = -EIDRM;
3164                 if (!mls_context_isvalid(&policydb, &ctx_new))
3165                         goto out_free;
3166
3167                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3168                 if (rc)
3169                         goto out_free;
3170
3171                 security_netlbl_cache_add(secattr, *sid);
3172
3173                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3174         } else
3175                 *sid = SECSID_NULL;
3176
3177         read_unlock(&policy_rwlock);
3178         return 0;
3179 out_free:
3180         ebitmap_destroy(&ctx_new.range.level[0].cat);
3181 out:
3182         read_unlock(&policy_rwlock);
3183         return rc;
3184 }
3185
3186 /**
3187  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3188  * @sid: the SELinux SID
3189  * @secattr: the NetLabel packet security attributes
3190  *
3191  * Description:
3192  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3193  * Returns zero on success, negative values on failure.
3194  *
3195  */
3196 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3197 {
3198         int rc;
3199         struct context *ctx;
3200
3201         if (!ss_initialized)
3202                 return 0;
3203
3204         read_lock(&policy_rwlock);
3205
3206         rc = -ENOENT;
3207         ctx = sidtab_search(&sidtab, sid);
3208         if (ctx == NULL)
3209                 goto out;
3210
3211         rc = -ENOMEM;
3212         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3213                                   GFP_ATOMIC);
3214         if (secattr->domain == NULL)
3215                 goto out;
3216
3217         secattr->attr.secid = sid;
3218         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3219         mls_export_netlbl_lvl(ctx, secattr);
3220         rc = mls_export_netlbl_cat(ctx, secattr);
3221 out:
3222         read_unlock(&policy_rwlock);
3223         return rc;
3224 }
3225 #endif /* CONFIG_NETLABEL */
3226
3227 /**
3228  * security_read_policy - read the policy.
3229  * @data: binary policy data
3230  * @len: length of data in bytes
3231  *
3232  */
3233 int security_read_policy(void **data, size_t *len)
3234 {
3235         int rc;
3236         struct policy_file fp;
3237
3238         if (!ss_initialized)
3239                 return -EINVAL;
3240
3241         *len = security_policydb_len();
3242
3243         *data = vmalloc_user(*len);
3244         if (!*data)
3245                 return -ENOMEM;
3246
3247         fp.data = *data;
3248         fp.len = *len;
3249
3250         read_lock(&policy_rwlock);
3251         rc = policydb_write(&policydb, &fp);
3252         read_unlock(&policy_rwlock);
3253
3254         if (rc)
3255                 return rc;
3256
3257         *len = (unsigned long)fp.data - (unsigned long)*data;
3258         return 0;
3259
3260 }