security/selinux/ss/services.c

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