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