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