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