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