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))
 705                 goto out;
 706         if (context_struct_to_string(ncontext, &n, &nlen))
 707                 goto out;
 708         if (context_struct_to_string(tcontext, &t, &tlen))
 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;
 805
 806         read_lock(&policy_rwlock);
 807
 808         rc = -EINVAL;
 809         old_context = sidtab_search(&sidtab, old_sid);
 810         if (!old_context) {
 811                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 812                        __func__, old_sid);
 813                 goto out;
 814         }
 815
 816         rc = -EINVAL;
 817         new_context = sidtab_search(&sidtab, new_sid);
 818         if (!new_context) {
 819                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 820                        __func__, new_sid);
 821                 goto out;
 822         }
 823
 824         rc = 0;
 825         /* type/domain unchanged */
 826         if (old_context->type == new_context->type)
 827                 goto out;
 828
 829         index = new_context->type;
 830         while (true) {
 831                 type = policydb.type_val_to_struct[index - 1];
 832                 BUG_ON(!type);
 833
 834                 /* not bounded anymore */
 835                 rc = -EPERM;
 836                 if (!type->bounds)
 837                         break;
 838
 839                 /* @newsid is bounded by @oldsid */
 840                 rc = 0;
 841                 if (type->bounds == old_context->type)
 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         rc = -EINVAL;
1191         if ((p - scontext) < scontext_len)
1192                 goto out;
1193
1194         /* Check the validity of the new context. */
1195         if (!policydb_context_isvalid(pol, ctx))
1196                 goto out;
1197         rc = 0;
1198 out:
1199         if (rc)
1200                 context_destroy(ctx);
1201         return rc;
1202 }
1203
1204 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1205                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1206                                         int force)
1207 {
1208         char *scontext2, *str = NULL;
1209         struct context context;
1210         int rc = 0;
1211
1212         if (!ss_initialized) {
1213                 int i;
1214
1215                 for (i = 1; i < SECINITSID_NUM; i++) {
1216                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1217                                 *sid = i;
1218                                 return 0;
1219                         }
1220                 }
1221                 *sid = SECINITSID_KERNEL;
1222                 return 0;
1223         }
1224         *sid = SECSID_NULL;
1225
1226         /* Copy the string so that we can modify the copy as we parse it. */
1227         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1228         if (!scontext2)
1229                 return -ENOMEM;
1230         memcpy(scontext2, scontext, scontext_len);
1231         scontext2[scontext_len] = 0;
1232
1233         if (force) {
1234                 /* Save another copy for storing in uninterpreted form */
1235                 rc = -ENOMEM;
1236                 str = kstrdup(scontext2, gfp_flags);
1237                 if (!str)
1238                         goto out;
1239         }
1240
1241         read_lock(&policy_rwlock);
1242         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1243                                       scontext_len, &context, def_sid);
1244         if (rc == -EINVAL && force) {
1245                 context.str = str;
1246                 context.len = scontext_len;
1247                 str = NULL;
1248         } else if (rc)
1249                 goto out_unlock;
1250         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1251         context_destroy(&context);
1252 out_unlock:
1253         read_unlock(&policy_rwlock);
1254 out:
1255         kfree(scontext2);
1256         kfree(str);
1257         return rc;
1258 }
1259
1260 /**
1261  * security_context_to_sid - Obtain a SID for a given security context.
1262  * @scontext: security context
1263  * @scontext_len: length in bytes
1264  * @sid: security identifier, SID
1265  *
1266  * Obtains a SID associated with the security context that
1267  * has the string representation specified by @scontext.
1268  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1269  * memory is available, or 0 on success.
1270  */
1271 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1272 {
1273         return security_context_to_sid_core(scontext, scontext_len,
1274                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1275 }
1276
1277 /**
1278  * security_context_to_sid_default - Obtain a SID for a given security context,
1279  * falling back to specified default if needed.
1280  *
1281  * @scontext: security context
1282  * @scontext_len: length in bytes
1283  * @sid: security identifier, SID
1284  * @def_sid: default SID to assign on error
1285  *
1286  * Obtains a SID associated with the security context that
1287  * has the string representation specified by @scontext.
1288  * The default SID is passed to the MLS layer to be used to allow
1289  * kernel labeling of the MLS field if the MLS field is not present
1290  * (for upgrading to MLS without full relabel).
1291  * Implicitly forces adding of the context even if it cannot be mapped yet.
1292  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1293  * memory is available, or 0 on success.
1294  */
1295 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1296                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1297 {
1298         return security_context_to_sid_core(scontext, scontext_len,
1299                                             sid, def_sid, gfp_flags, 1);
1300 }
1301
1302 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1303                                   u32 *sid)
1304 {
1305         return security_context_to_sid_core(scontext, scontext_len,
1306                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1307 }
1308
1309 static int compute_sid_handle_invalid_context(
1310         struct context *scontext,
1311         struct context *tcontext,
1312         u16 tclass,
1313         struct context *newcontext)
1314 {
1315         char *s = NULL, *t = NULL, *n = NULL;
1316         u32 slen, tlen, nlen;
1317
1318         if (context_struct_to_string(scontext, &s, &slen))
1319                 goto out;
1320         if (context_struct_to_string(tcontext, &t, &tlen))
1321                 goto out;
1322         if (context_struct_to_string(newcontext, &n, &nlen))
1323                 goto out;
1324         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1325                   "security_compute_sid:  invalid context %s"
1326                   " for scontext=%s"
1327                   " tcontext=%s"
1328                   " tclass=%s",
1329                   n, s, t, policydb.p_class_val_to_name[tclass-1]);
1330 out:
1331         kfree(s);
1332         kfree(t);
1333         kfree(n);
1334         if (!selinux_enforcing)
1335                 return 0;
1336         return -EACCES;
1337 }
1338
1339 static int security_compute_sid(u32 ssid,
1340                                 u32 tsid,
1341                                 u16 orig_tclass,
1342                                 u32 specified,
1343                                 u32 *out_sid,
1344                                 bool kern)
1345 {
1346         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1347         struct role_trans *roletr = NULL;
1348         struct avtab_key avkey;
1349         struct avtab_datum *avdatum;
1350         struct avtab_node *node;
1351         u16 tclass;
1352         int rc = 0;
1353
1354         if (!ss_initialized) {
1355                 switch (orig_tclass) {
1356                 case SECCLASS_PROCESS: /* kernel value */
1357                         *out_sid = ssid;
1358                         break;
1359                 default:
1360                         *out_sid = tsid;
1361                         break;
1362                 }
1363                 goto out;
1364         }
1365
1366         context_init(&newcontext);
1367
1368         read_lock(&policy_rwlock);
1369
1370         if (kern)
1371                 tclass = unmap_class(orig_tclass);
1372         else
1373                 tclass = orig_tclass;
1374
1375         scontext = sidtab_search(&sidtab, ssid);
1376         if (!scontext) {
1377                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1378                        __func__, ssid);
1379                 rc = -EINVAL;
1380                 goto out_unlock;
1381         }
1382         tcontext = sidtab_search(&sidtab, tsid);
1383         if (!tcontext) {
1384                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1385                        __func__, tsid);
1386                 rc = -EINVAL;
1387                 goto out_unlock;
1388         }
1389
1390         /* Set the user identity. */
1391         switch (specified) {
1392         case AVTAB_TRANSITION:
1393         case AVTAB_CHANGE:
1394                 /* Use the process user identity. */
1395                 newcontext.user = scontext->user;
1396                 break;
1397         case AVTAB_MEMBER:
1398                 /* Use the related object owner. */
1399                 newcontext.user = tcontext->user;
1400                 break;
1401         }
1402
1403         /* Set the role and type to default values. */
1404         if (tclass == policydb.process_class) {
1405                 /* Use the current role and type of process. */
1406                 newcontext.role = scontext->role;
1407                 newcontext.type = scontext->type;
1408         } else {
1409                 /* Use the well-defined object role. */
1410                 newcontext.role = OBJECT_R_VAL;
1411                 /* Use the type of the related object. */
1412                 newcontext.type = tcontext->type;
1413         }
1414
1415         /* Look for a type transition/member/change rule. */
1416         avkey.source_type = scontext->type;
1417         avkey.target_type = tcontext->type;
1418         avkey.target_class = tclass;
1419         avkey.specified = specified;
1420         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1421
1422         /* If no permanent rule, also check for enabled conditional rules */
1423         if (!avdatum) {
1424                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1425                 for (; node; node = avtab_search_node_next(node, specified)) {
1426                         if (node->key.specified & AVTAB_ENABLED) {
1427                                 avdatum = &node->datum;
1428                                 break;
1429                         }
1430                 }
1431         }
1432
1433         if (avdatum) {
1434                 /* Use the type from the type transition/member/change rule. */
1435                 newcontext.type = avdatum->data;
1436         }
1437
1438         /* Check for class-specific changes. */
1439         if  (tclass == policydb.process_class) {
1440                 if (specified & AVTAB_TRANSITION) {
1441                         /* Look for a role transition rule. */
1442                         for (roletr = policydb.role_tr; roletr;
1443                              roletr = roletr->next) {
1444                                 if (roletr->role == scontext->role &&
1445                                     roletr->type == tcontext->type) {
1446                                         /* Use the role transition rule. */
1447                                         newcontext.role = roletr->new_role;
1448                                         break;
1449                                 }
1450                         }
1451                 }
1452         }
1453
1454         /* Set the MLS attributes.
1455            This is done last because it may allocate memory. */
1456         rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
1457         if (rc)
1458                 goto out_unlock;
1459
1460         /* Check the validity of the context. */
1461         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1462                 rc = compute_sid_handle_invalid_context(scontext,
1463                                                         tcontext,
1464                                                         tclass,
1465                                                         &newcontext);
1466                 if (rc)
1467                         goto out_unlock;
1468         }
1469         /* Obtain the sid for the context. */
1470         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1471 out_unlock:
1472         read_unlock(&policy_rwlock);
1473         context_destroy(&newcontext);
1474 out:
1475         return rc;
1476 }
1477
1478 /**
1479  * security_transition_sid - Compute the SID for a new subject/object.
1480  * @ssid: source security identifier
1481  * @tsid: target security identifier
1482  * @tclass: target security class
1483  * @out_sid: security identifier for new subject/object
1484  *
1485  * Compute a SID to use for labeling a new subject or object in the
1486  * class @tclass based on a SID pair (@ssid, @tsid).
1487  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1488  * if insufficient memory is available, or %0 if the new SID was
1489  * computed successfully.
1490  */
1491 int security_transition_sid(u32 ssid,
1492                             u32 tsid,
1493                             u16 tclass,
1494                             u32 *out_sid)
1495 {
1496         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1497                                     out_sid, true);
1498 }
1499
1500 int security_transition_sid_user(u32 ssid,
1501                                  u32 tsid,
1502                                  u16 tclass,
1503                                  u32 *out_sid)
1504 {
1505         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1506                                     out_sid, false);
1507 }
1508
1509 /**
1510  * security_member_sid - Compute the SID for member selection.
1511  * @ssid: source security identifier
1512  * @tsid: target security identifier
1513  * @tclass: target security class
1514  * @out_sid: security identifier for selected member
1515  *
1516  * Compute a SID to use when selecting a member of a polyinstantiated
1517  * object of class @tclass based on a SID pair (@ssid, @tsid).
1518  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1519  * if insufficient memory is available, or %0 if the SID was
1520  * computed successfully.
1521  */
1522 int security_member_sid(u32 ssid,
1523                         u32 tsid,
1524                         u16 tclass,
1525                         u32 *out_sid)
1526 {
1527         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid,
1528                                     false);
1529 }
1530
1531 /**
1532  * security_change_sid - Compute the SID for object relabeling.
1533  * @ssid: source security identifier
1534  * @tsid: target security identifier
1535  * @tclass: target security class
1536  * @out_sid: security identifier for selected member
1537  *
1538  * Compute a SID to use for relabeling an object of class @tclass
1539  * based on a SID pair (@ssid, @tsid).
1540  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1541  * if insufficient memory is available, or %0 if the SID was
1542  * computed successfully.
1543  */
1544 int security_change_sid(u32 ssid,
1545                         u32 tsid,
1546                         u16 tclass,
1547                         u32 *out_sid)
1548 {
1549         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid,
1550                                     false);
1551 }
1552
1553 /* Clone the SID into the new SID table. */
1554 static int clone_sid(u32 sid,
1555                      struct context *context,
1556                      void *arg)
1557 {
1558         struct sidtab *s = arg;
1559
1560         if (sid > SECINITSID_NUM)
1561                 return sidtab_insert(s, sid, context);
1562         else
1563                 return 0;
1564 }
1565
1566 static inline int convert_context_handle_invalid_context(struct context *context)
1567 {
1568         char *s;
1569         u32 len;
1570
1571         if (selinux_enforcing)
1572                 return -EINVAL;
1573
1574         if (!context_struct_to_string(context, &s, &len)) {
1575                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1576                 kfree(s);
1577         }
1578         return 0;
1579 }
1580
1581 struct convert_context_args {
1582         struct policydb *oldp;
1583         struct policydb *newp;
1584 };
1585
1586 /*
1587  * Convert the values in the security context
1588  * structure `c' from the values specified
1589  * in the policy `p->oldp' to the values specified
1590  * in the policy `p->newp'.  Verify that the
1591  * context is valid under the new policy.
1592  */
1593 static int convert_context(u32 key,
1594                            struct context *c,
1595                            void *p)
1596 {
1597         struct convert_context_args *args;
1598         struct context oldc;
1599         struct ocontext *oc;
1600         struct mls_range *range;
1601         struct role_datum *role;
1602         struct type_datum *typdatum;
1603         struct user_datum *usrdatum;
1604         char *s;
1605         u32 len;
1606         int rc = 0;
1607
1608         if (key <= SECINITSID_NUM)
1609                 goto out;
1610
1611         args = p;
1612
1613         if (c->str) {
1614                 struct context ctx;
1615
1616                 rc = -ENOMEM;
1617                 s = kstrdup(c->str, GFP_KERNEL);
1618                 if (!s)
1619                         goto out;
1620
1621                 rc = string_to_context_struct(args->newp, NULL, s,
1622                                               c->len, &ctx, SECSID_NULL);
1623                 kfree(s);
1624                 if (!rc) {
1625                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1626                                c->str);
1627                         /* Replace string with mapped representation. */
1628                         kfree(c->str);
1629                         memcpy(c, &ctx, sizeof(*c));
1630                         goto out;
1631                 } else if (rc == -EINVAL) {
1632                         /* Retain string representation for later mapping. */
1633                         rc = 0;
1634                         goto out;
1635                 } else {
1636                         /* Other error condition, e.g. ENOMEM. */
1637                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1638                                c->str, -rc);
1639                         goto out;
1640                 }
1641         }
1642
1643         rc = context_cpy(&oldc, c);
1644         if (rc)
1645                 goto out;
1646
1647         /* Convert the user. */
1648         rc = -EINVAL;
1649         usrdatum = hashtab_search(args->newp->p_users.table,
1650                                   args->oldp->p_user_val_to_name[c->user - 1]);
1651         if (!usrdatum)
1652                 goto bad;
1653         c->user = usrdatum->value;
1654
1655         /* Convert the role. */
1656         rc = -EINVAL;
1657         role = hashtab_search(args->newp->p_roles.table,
1658                               args->oldp->p_role_val_to_name[c->role - 1]);
1659         if (!role)
1660                 goto bad;
1661         c->role = role->value;
1662
1663         /* Convert the type. */
1664         rc = -EINVAL;
1665         typdatum = hashtab_search(args->newp->p_types.table,
1666                                   args->oldp->p_type_val_to_name[c->type - 1]);
1667         if (!typdatum)
1668                 goto bad;
1669         c->type = typdatum->value;
1670
1671         /* Convert the MLS fields if dealing with MLS policies */
1672         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1673                 rc = mls_convert_context(args->oldp, args->newp, c);
1674                 if (rc)
1675                         goto bad;
1676         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1677                 /*
1678                  * Switching between MLS and non-MLS policy:
1679                  * free any storage used by the MLS fields in the
1680                  * context for all existing entries in the sidtab.
1681                  */
1682                 mls_context_destroy(c);
1683         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1684                 /*
1685                  * Switching between non-MLS and MLS policy:
1686                  * ensure that the MLS fields of the context for all
1687                  * existing entries in the sidtab are filled in with a
1688                  * suitable default value, likely taken from one of the
1689                  * initial SIDs.
1690                  */
1691                 oc = args->newp->ocontexts[OCON_ISID];
1692                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1693                         oc = oc->next;
1694                 rc = -EINVAL;
1695                 if (!oc) {
1696                         printk(KERN_ERR "SELinux:  unable to look up"
1697                                 " the initial SIDs list\n");
1698                         goto bad;
1699                 }
1700                 range = &oc->context[0].range;
1701                 rc = mls_range_set(c, range);
1702                 if (rc)
1703                         goto bad;
1704         }
1705
1706         /* Check the validity of the new context. */
1707         if (!policydb_context_isvalid(args->newp, c)) {
1708                 rc = convert_context_handle_invalid_context(&oldc);
1709                 if (rc)
1710                         goto bad;
1711         }
1712
1713         context_destroy(&oldc);
1714
1715         rc = 0;
1716 out:
1717         return rc;
1718 bad:
1719         /* Map old representation to string and save it. */
1720         rc = context_struct_to_string(&oldc, &s, &len);
1721         if (rc)
1722                 return rc;
1723         context_destroy(&oldc);
1724         context_destroy(c);
1725         c->str = s;
1726         c->len = len;
1727         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1728                c->str);
1729         rc = 0;
1730         goto out;
1731 }
1732
1733 static void security_load_policycaps(void)
1734 {
1735         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1736                                                   POLICYDB_CAPABILITY_NETPEER);
1737         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1738                                                   POLICYDB_CAPABILITY_OPENPERM);
1739 }
1740
1741 extern void selinux_complete_init(void);
1742 static int security_preserve_bools(struct policydb *p);
1743
1744 /**
1745  * security_load_policy - Load a security policy configuration.
1746  * @data: binary policy data
1747  * @len: length of data in bytes
1748  *
1749  * Load a new set of security policy configuration data,
1750  * validate it and convert the SID table as necessary.
1751  * This function will flush the access vector cache after
1752  * loading the new policy.
1753  */
1754 int security_load_policy(void *data, size_t len)
1755 {
1756         struct policydb oldpolicydb, newpolicydb;
1757         struct sidtab oldsidtab, newsidtab;
1758         struct selinux_mapping *oldmap, *map = NULL;
1759         struct convert_context_args args;
1760         u32 seqno;
1761         u16 map_size;
1762         int rc = 0;
1763         struct policy_file file = { data, len }, *fp = &file;
1764
1765         if (!ss_initialized) {
1766                 avtab_cache_init();
1767                 rc = policydb_read(&policydb, fp);
1768                 if (rc) {
1769                         avtab_cache_destroy();
1770                         return rc;
1771                 }
1772
1773                 policydb.len = len;
1774                 rc = selinux_set_mapping(&policydb, secclass_map,
1775                                          &current_mapping,
1776                                          &current_mapping_size);
1777                 if (rc) {
1778                         policydb_destroy(&policydb);
1779                         avtab_cache_destroy();
1780                         return rc;
1781                 }
1782
1783                 rc = policydb_load_isids(&policydb, &sidtab);
1784                 if (rc) {
1785                         policydb_destroy(&policydb);
1786                         avtab_cache_destroy();
1787                         return rc;
1788                 }
1789
1790                 security_load_policycaps();
1791                 ss_initialized = 1;
1792                 seqno = ++latest_granting;
1793                 selinux_complete_init();
1794                 avc_ss_reset(seqno);
1795                 selnl_notify_policyload(seqno);
1796                 selinux_status_update_policyload(seqno);
1797                 selinux_netlbl_cache_invalidate();
1798                 selinux_xfrm_notify_policyload();
1799                 return 0;
1800         }
1801
1802 #if 0
1803         sidtab_hash_eval(&sidtab, "sids");
1804 #endif
1805
1806         rc = policydb_read(&newpolicydb, fp);
1807         if (rc)
1808                 return rc;
1809
1810         newpolicydb.len = len;
1811         /* If switching between different policy types, log MLS status */
1812         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1813                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1814         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1815                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1816
1817         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1818         if (rc) {
1819                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1820                 policydb_destroy(&newpolicydb);
1821                 return rc;
1822         }
1823
1824         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1825         if (rc)
1826                 goto err;
1827
1828         rc = security_preserve_bools(&newpolicydb);
1829         if (rc) {
1830                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1831                 goto err;
1832         }
1833
1834         /* Clone the SID table. */
1835         sidtab_shutdown(&sidtab);
1836
1837         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1838         if (rc)
1839                 goto err;
1840
1841         /*
1842          * Convert the internal representations of contexts
1843          * in the new SID table.
1844          */
1845         args.oldp = &policydb;
1846         args.newp = &newpolicydb;
1847         rc = sidtab_map(&newsidtab, convert_context, &args);
1848         if (rc) {
1849                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1850                         " representation of contexts in the new SID"
1851                         " table\n");
1852                 goto err;
1853         }
1854
1855         /* Save the old policydb and SID table to free later. */
1856         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1857         sidtab_set(&oldsidtab, &sidtab);
1858
1859         /* Install the new policydb and SID table. */
1860         write_lock_irq(&policy_rwlock);
1861         memcpy(&policydb, &newpolicydb, sizeof policydb);
1862         sidtab_set(&sidtab, &newsidtab);
1863         security_load_policycaps();
1864         oldmap = current_mapping;
1865         current_mapping = map;
1866         current_mapping_size = map_size;
1867         seqno = ++latest_granting;
1868         write_unlock_irq(&policy_rwlock);
1869
1870         /* Free the old policydb and SID table. */
1871         policydb_destroy(&oldpolicydb);
1872         sidtab_destroy(&oldsidtab);
1873         kfree(oldmap);
1874
1875         avc_ss_reset(seqno);
1876         selnl_notify_policyload(seqno);
1877         selinux_status_update_policyload(seqno);
1878         selinux_netlbl_cache_invalidate();
1879         selinux_xfrm_notify_policyload();
1880
1881         return 0;
1882
1883 err:
1884         kfree(map);
1885         sidtab_destroy(&newsidtab);
1886         policydb_destroy(&newpolicydb);
1887         return rc;
1888
1889 }
1890
1891 size_t security_policydb_len(void)
1892 {
1893         size_t len;
1894
1895         read_lock(&policy_rwlock);
1896         len = policydb.len;
1897         read_unlock(&policy_rwlock);
1898
1899         return len;
1900 }
1901
1902 /**
1903  * security_port_sid - Obtain the SID for a port.
1904  * @protocol: protocol number
1905  * @port: port number
1906  * @out_sid: security identifier
1907  */
1908 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1909 {
1910         struct ocontext *c;
1911         int rc = 0;
1912
1913         read_lock(&policy_rwlock);
1914
1915         c = policydb.ocontexts[OCON_PORT];
1916         while (c) {
1917                 if (c->u.port.protocol == protocol &&
1918                     c->u.port.low_port <= port &&
1919                     c->u.port.high_port >= port)
1920                         break;
1921                 c = c->next;
1922         }
1923
1924         if (c) {
1925                 if (!c->sid[0]) {
1926                         rc = sidtab_context_to_sid(&sidtab,
1927                                                    &c->context[0],
1928                                                    &c->sid[0]);
1929                         if (rc)
1930                                 goto out;
1931                 }
1932                 *out_sid = c->sid[0];
1933         } else {
1934                 *out_sid = SECINITSID_PORT;
1935         }
1936
1937 out:
1938         read_unlock(&policy_rwlock);
1939         return rc;
1940 }
1941
1942 /**
1943  * security_netif_sid - Obtain the SID for a network interface.
1944  * @name: interface name
1945  * @if_sid: interface SID
1946  */
1947 int security_netif_sid(char *name, u32 *if_sid)
1948 {
1949         int rc = 0;
1950         struct ocontext *c;
1951
1952         read_lock(&policy_rwlock);
1953
1954         c = policydb.ocontexts[OCON_NETIF];
1955         while (c) {
1956                 if (strcmp(name, c->u.name) == 0)
1957                         break;
1958                 c = c->next;
1959         }
1960
1961         if (c) {
1962                 if (!c->sid[0] || !c->sid[1]) {
1963                         rc = sidtab_context_to_sid(&sidtab,
1964                                                   &c->context[0],
1965                                                   &c->sid[0]);
1966                         if (rc)
1967                                 goto out;
1968                         rc = sidtab_context_to_sid(&sidtab,
1969                                                    &c->context[1],
1970                                                    &c->sid[1]);
1971                         if (rc)
1972                                 goto out;
1973                 }
1974                 *if_sid = c->sid[0];
1975         } else
1976                 *if_sid = SECINITSID_NETIF;
1977
1978 out:
1979         read_unlock(&policy_rwlock);
1980         return rc;
1981 }
1982
1983 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1984 {
1985         int i, fail = 0;
1986
1987         for (i = 0; i < 4; i++)
1988                 if (addr[i] != (input[i] & mask[i])) {
1989                         fail = 1;
1990                         break;
1991                 }
1992
1993         return !fail;
1994 }
1995
1996 /**
1997  * security_node_sid - Obtain the SID for a node (host).
1998  * @domain: communication domain aka address family
1999  * @addrp: address
2000  * @addrlen: address length in bytes
2001  * @out_sid: security identifier
2002  */
2003 int security_node_sid(u16 domain,
2004                       void *addrp,
2005                       u32 addrlen,
2006                       u32 *out_sid)
2007 {
2008         int rc;
2009         struct ocontext *c;
2010
2011         read_lock(&policy_rwlock);
2012
2013         switch (domain) {
2014         case AF_INET: {
2015                 u32 addr;
2016
2017                 rc = -EINVAL;
2018                 if (addrlen != sizeof(u32))
2019                         goto out;
2020
2021                 addr = *((u32 *)addrp);
2022
2023                 c = policydb.ocontexts[OCON_NODE];
2024                 while (c) {
2025                         if (c->u.node.addr == (addr & c->u.node.mask))
2026                                 break;
2027                         c = c->next;
2028                 }
2029                 break;
2030         }
2031
2032         case AF_INET6:
2033                 rc = -EINVAL;
2034                 if (addrlen != sizeof(u64) * 2)
2035                         goto out;
2036                 c = policydb.ocontexts[OCON_NODE6];
2037                 while (c) {
2038                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2039                                                 c->u.node6.mask))
2040                                 break;
2041                         c = c->next;
2042                 }
2043                 break;
2044
2045         default:
2046                 rc = 0;
2047                 *out_sid = SECINITSID_NODE;
2048                 goto out;
2049         }
2050
2051         if (c) {
2052                 if (!c->sid[0]) {
2053                         rc = sidtab_context_to_sid(&sidtab,
2054                                                    &c->context[0],
2055                                                    &c->sid[0]);
2056                         if (rc)
2057                                 goto out;
2058                 }
2059                 *out_sid = c->sid[0];
2060         } else {
2061                 *out_sid = SECINITSID_NODE;
2062         }
2063
2064         rc = 0;
2065 out:
2066         read_unlock(&policy_rwlock);
2067         return rc;
2068 }
2069
2070 #define SIDS_NEL 25
2071
2072 /**
2073  * security_get_user_sids - Obtain reachable SIDs for a user.
2074  * @fromsid: starting SID
2075  * @username: username
2076  * @sids: array of reachable SIDs for user
2077  * @nel: number of elements in @sids
2078  *
2079  * Generate the set of SIDs for legal security contexts
2080  * for a given user that can be reached by @fromsid.
2081  * Set *@sids to point to a dynamically allocated
2082  * array containing the set of SIDs.  Set *@nel to the
2083  * number of elements in the array.
2084  */
2085
2086 int security_get_user_sids(u32 fromsid,
2087                            char *username,
2088                            u32 **sids,
2089                            u32 *nel)
2090 {
2091         struct context *fromcon, usercon;
2092         u32 *mysids = NULL, *mysids2, sid;
2093         u32 mynel = 0, maxnel = SIDS_NEL;
2094         struct user_datum *user;
2095         struct role_datum *role;
2096         struct ebitmap_node *rnode, *tnode;
2097         int rc = 0, i, j;
2098
2099         *sids = NULL;
2100         *nel = 0;
2101
2102         if (!ss_initialized)
2103                 goto out;
2104
2105         read_lock(&policy_rwlock);
2106
2107         context_init(&usercon);
2108
2109         rc = -EINVAL;
2110         fromcon = sidtab_search(&sidtab, fromsid);
2111         if (!fromcon)
2112                 goto out_unlock;
2113
2114         rc = -EINVAL;
2115         user = hashtab_search(policydb.p_users.table, username);
2116         if (!user)
2117                 goto out_unlock;
2118
2119         usercon.user = user->value;
2120
2121         rc = -ENOMEM;
2122         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2123         if (!mysids)
2124                 goto out_unlock;
2125
2126         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2127                 role = policydb.role_val_to_struct[i];
2128                 usercon.role = i + 1;
2129                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2130                         usercon.type = j + 1;
2131
2132                         if (mls_setup_user_range(fromcon, user, &usercon))
2133                                 continue;
2134
2135                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2136                         if (rc)
2137                                 goto out_unlock;
2138                         if (mynel < maxnel) {
2139                                 mysids[mynel++] = sid;
2140                         } else {
2141                                 rc = -ENOMEM;
2142                                 maxnel += SIDS_NEL;
2143                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2144                                 if (!mysids2)
2145                                         goto out_unlock;
2146                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2147                                 kfree(mysids);
2148                                 mysids = mysids2;
2149                                 mysids[mynel++] = sid;
2150                         }
2151                 }
2152         }
2153         rc = 0;
2154 out_unlock:
2155         read_unlock(&policy_rwlock);
2156         if (rc || !mynel) {
2157                 kfree(mysids);
2158                 goto out;
2159         }
2160
2161         rc = -ENOMEM;
2162         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2163         if (!mysids2) {
2164                 kfree(mysids);
2165                 goto out;
2166         }
2167         for (i = 0, j = 0; i < mynel; i++) {
2168                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2169                                           SECCLASS_PROCESS, /* kernel value */
2170                                           PROCESS__TRANSITION, AVC_STRICT,
2171                                           NULL);
2172                 if (!rc)
2173                         mysids2[j++] = mysids[i];
2174                 cond_resched();
2175         }
2176         rc = 0;
2177         kfree(mysids);
2178         *sids = mysids2;
2179         *nel = j;
2180 out:
2181         return rc;
2182 }
2183
2184 /**
2185  * security_genfs_sid - Obtain a SID for a file in a filesystem
2186  * @fstype: filesystem type
2187  * @path: path from root of mount
2188  * @sclass: file security class
2189  * @sid: SID for path
2190  *
2191  * Obtain a SID to use for a file in a filesystem that
2192  * cannot support xattr or use a fixed labeling behavior like
2193  * transition SIDs or task SIDs.
2194  */
2195 int security_genfs_sid(const char *fstype,
2196                        char *path,
2197                        u16 orig_sclass,
2198                        u32 *sid)
2199 {
2200         int len;
2201         u16 sclass;
2202         struct genfs *genfs;
2203         struct ocontext *c;
2204         int rc, cmp = 0;
2205
2206         while (path[0] == '/' && path[1] == '/')
2207                 path++;
2208
2209         read_lock(&policy_rwlock);
2210
2211         sclass = unmap_class(orig_sclass);
2212         *sid = SECINITSID_UNLABELED;
2213
2214         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2215                 cmp = strcmp(fstype, genfs->fstype);
2216                 if (cmp <= 0)
2217                         break;
2218         }
2219
2220         rc = -ENOENT;
2221         if (!genfs || cmp)
2222                 goto out;
2223
2224         for (c = genfs->head; c; c = c->next) {
2225                 len = strlen(c->u.name);
2226                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2227                     (strncmp(c->u.name, path, len) == 0))
2228                         break;
2229         }
2230
2231         rc = -ENOENT;
2232         if (!c)
2233                 goto out;
2234
2235         if (!c->sid[0]) {
2236                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2237                 if (rc)
2238                         goto out;
2239         }
2240
2241         *sid = c->sid[0];
2242         rc = 0;
2243 out:
2244         read_unlock(&policy_rwlock);
2245         return rc;
2246 }
2247
2248 /**
2249  * security_fs_use - Determine how to handle labeling for a filesystem.
2250  * @fstype: filesystem type
2251  * @behavior: labeling behavior
2252  * @sid: SID for filesystem (superblock)
2253  */
2254 int security_fs_use(
2255         const char *fstype,
2256         unsigned int *behavior,
2257         u32 *sid)
2258 {
2259         int rc = 0;
2260         struct ocontext *c;
2261
2262         read_lock(&policy_rwlock);
2263
2264         c = policydb.ocontexts[OCON_FSUSE];
2265         while (c) {
2266                 if (strcmp(fstype, c->u.name) == 0)
2267                         break;
2268                 c = c->next;
2269         }
2270
2271         if (c) {
2272                 *behavior = c->v.behavior;
2273                 if (!c->sid[0]) {
2274                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2275                                                    &c->sid[0]);
2276                         if (rc)
2277                                 goto out;
2278                 }
2279                 *sid = c->sid[0];
2280         } else {
2281                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2282                 if (rc) {
2283                         *behavior = SECURITY_FS_USE_NONE;
2284                         rc = 0;
2285                 } else {
2286                         *behavior = SECURITY_FS_USE_GENFS;
2287                 }
2288         }
2289
2290 out:
2291         read_unlock(&policy_rwlock);
2292         return rc;
2293 }
2294
2295 int security_get_bools(int *len, char ***names, int **values)
2296 {
2297         int i, rc;
2298
2299         read_lock(&policy_rwlock);
2300         *names = NULL;
2301         *values = NULL;
2302
2303         rc = 0;
2304         *len = policydb.p_bools.nprim;
2305         if (!*len)
2306                 goto out;
2307
2308         rc = -ENOMEM;
2309         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2310         if (!*names)
2311                 goto err;
2312
2313         rc = -ENOMEM;
2314         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2315         if (!*values)
2316                 goto err;
2317
2318         for (i = 0; i < *len; i++) {
2319                 size_t name_len;
2320
2321                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2322                 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
2323
2324                 rc = -ENOMEM;
2325                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2326                 if (!(*names)[i])
2327                         goto err;
2328
2329                 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
2330                 (*names)[i][name_len - 1] = 0;
2331         }
2332         rc = 0;
2333 out:
2334         read_unlock(&policy_rwlock);
2335         return rc;
2336 err:
2337         if (*names) {
2338                 for (i = 0; i < *len; i++)
2339                         kfree((*names)[i]);
2340         }
2341         kfree(*values);
2342         goto out;
2343 }
2344
2345
2346 int security_set_bools(int len, int *values)
2347 {
2348         int i, rc;
2349         int lenp, seqno = 0;
2350         struct cond_node *cur;
2351
2352         write_lock_irq(&policy_rwlock);
2353
2354         rc = -EFAULT;
2355         lenp = policydb.p_bools.nprim;
2356         if (len != lenp)
2357                 goto out;
2358
2359         for (i = 0; i < len; i++) {
2360                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2361                         audit_log(current->audit_context, GFP_ATOMIC,
2362                                 AUDIT_MAC_CONFIG_CHANGE,
2363                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2364                                 policydb.p_bool_val_to_name[i],
2365                                 !!values[i],
2366                                 policydb.bool_val_to_struct[i]->state,
2367                                 audit_get_loginuid(current),
2368                                 audit_get_sessionid(current));
2369                 }
2370                 if (values[i])
2371                         policydb.bool_val_to_struct[i]->state = 1;
2372                 else
2373                         policydb.bool_val_to_struct[i]->state = 0;
2374         }
2375
2376         for (cur = policydb.cond_list; cur; cur = cur->next) {
2377                 rc = evaluate_cond_node(&policydb, cur);
2378                 if (rc)
2379                         goto out;
2380         }
2381
2382         seqno = ++latest_granting;
2383         rc = 0;
2384 out:
2385         write_unlock_irq(&policy_rwlock);
2386         if (!rc) {
2387                 avc_ss_reset(seqno);
2388                 selnl_notify_policyload(seqno);
2389                 selinux_status_update_policyload(seqno);
2390                 selinux_xfrm_notify_policyload();
2391         }
2392         return rc;
2393 }
2394
2395 int security_get_bool_value(int bool)
2396 {
2397         int rc;
2398         int len;
2399
2400         read_lock(&policy_rwlock);
2401
2402         rc = -EFAULT;
2403         len = policydb.p_bools.nprim;
2404         if (bool >= len)
2405                 goto out;
2406
2407         rc = policydb.bool_val_to_struct[bool]->state;
2408 out:
2409         read_unlock(&policy_rwlock);
2410         return rc;
2411 }
2412
2413 static int security_preserve_bools(struct policydb *p)
2414 {
2415         int rc, nbools = 0, *bvalues = NULL, i;
2416         char **bnames = NULL;
2417         struct cond_bool_datum *booldatum;
2418         struct cond_node *cur;
2419
2420         rc = security_get_bools(&nbools, &bnames, &bvalues);
2421         if (rc)
2422                 goto out;
2423         for (i = 0; i < nbools; i++) {
2424                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2425                 if (booldatum)
2426                         booldatum->state = bvalues[i];
2427         }
2428         for (cur = p->cond_list; cur; cur = cur->next) {
2429                 rc = evaluate_cond_node(p, cur);
2430                 if (rc)
2431                         goto out;
2432         }
2433
2434 out:
2435         if (bnames) {
2436                 for (i = 0; i < nbools; i++)
2437                         kfree(bnames[i]);
2438         }
2439         kfree(bnames);
2440         kfree(bvalues);
2441         return rc;
2442 }
2443
2444 /*
2445  * security_sid_mls_copy() - computes a new sid based on the given
2446  * sid and the mls portion of mls_sid.
2447  */
2448 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2449 {
2450         struct context *context1;
2451         struct context *context2;
2452         struct context newcon;
2453         char *s;
2454         u32 len;
2455         int rc;
2456
2457         rc = 0;
2458         if (!ss_initialized || !policydb.mls_enabled) {
2459                 *new_sid = sid;
2460                 goto out;
2461         }
2462
2463         context_init(&newcon);
2464
2465         read_lock(&policy_rwlock);
2466
2467         rc = -EINVAL;
2468         context1 = sidtab_search(&sidtab, sid);
2469         if (!context1) {
2470                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2471                         __func__, sid);
2472                 goto out_unlock;
2473         }
2474
2475         rc = -EINVAL;
2476         context2 = sidtab_search(&sidtab, mls_sid);
2477         if (!context2) {
2478                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2479                         __func__, mls_sid);
2480                 goto out_unlock;
2481         }
2482
2483         newcon.user = context1->user;
2484         newcon.role = context1->role;
2485         newcon.type = context1->type;
2486         rc = mls_context_cpy(&newcon, context2);
2487         if (rc)
2488                 goto out_unlock;
2489
2490         /* Check the validity of the new context. */
2491         if (!policydb_context_isvalid(&policydb, &newcon)) {
2492                 rc = convert_context_handle_invalid_context(&newcon);
2493                 if (rc) {
2494                         if (!context_struct_to_string(&newcon, &s, &len)) {
2495                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2496                                           "security_sid_mls_copy: invalid context %s", s);
2497                                 kfree(s);
2498                         }
2499                         goto out_unlock;
2500                 }
2501         }
2502
2503         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2504 out_unlock:
2505         read_unlock(&policy_rwlock);
2506         context_destroy(&newcon);
2507 out:
2508         return rc;
2509 }
2510
2511 /**
2512  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2513  * @nlbl_sid: NetLabel SID
2514  * @nlbl_type: NetLabel labeling protocol type
2515  * @xfrm_sid: XFRM SID
2516  *
2517  * Description:
2518  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2519  * resolved into a single SID it is returned via @peer_sid and the function
2520  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2521  * returns a negative value.  A table summarizing the behavior is below:
2522  *
2523  *                                 | function return |      @sid
2524  *   ------------------------------+-----------------+-----------------
2525  *   no peer labels                |        0        |    SECSID_NULL
2526  *   single peer label             |        0        |    <peer_label>
2527  *   multiple, consistent labels   |        0        |    <peer_label>
2528  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2529  *
2530  */
2531 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2532                                  u32 xfrm_sid,
2533                                  u32 *peer_sid)
2534 {
2535         int rc;
2536         struct context *nlbl_ctx;
2537         struct context *xfrm_ctx;
2538
2539         *peer_sid = SECSID_NULL;
2540
2541         /* handle the common (which also happens to be the set of easy) cases
2542          * right away, these two if statements catch everything involving a
2543          * single or absent peer SID/label */
2544         if (xfrm_sid == SECSID_NULL) {
2545                 *peer_sid = nlbl_sid;
2546                 return 0;
2547         }
2548         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2549          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2550          * is present */
2551         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2552                 *peer_sid = xfrm_sid;
2553                 return 0;
2554         }
2555
2556         /* we don't need to check ss_initialized here since the only way both
2557          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2558          * security server was initialized and ss_initialized was true */
2559         if (!policydb.mls_enabled)
2560                 return 0;
2561
2562         read_lock(&policy_rwlock);
2563
2564         rc = -EINVAL;
2565         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2566         if (!nlbl_ctx) {
2567                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2568                        __func__, nlbl_sid);
2569                 goto out;
2570         }
2571         rc = -EINVAL;
2572         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2573         if (!xfrm_ctx) {
2574                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2575                        __func__, xfrm_sid);
2576                 goto out;
2577         }
2578         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2579         if (rc)
2580                 goto out;
2581
2582         /* at present NetLabel SIDs/labels really only carry MLS
2583          * information so if the MLS portion of the NetLabel SID
2584          * matches the MLS portion of the labeled XFRM SID/label
2585          * then pass along the XFRM SID as it is the most
2586          * expressive */
2587         *peer_sid = xfrm_sid;
2588 out:
2589         read_unlock(&policy_rwlock);
2590         return rc;
2591 }
2592
2593 static int get_classes_callback(void *k, void *d, void *args)
2594 {
2595         struct class_datum *datum = d;
2596         char *name = k, **classes = args;
2597         int value = datum->value - 1;
2598
2599         classes[value] = kstrdup(name, GFP_ATOMIC);
2600         if (!classes[value])
2601                 return -ENOMEM;
2602
2603         return 0;
2604 }
2605
2606 int security_get_classes(char ***classes, int *nclasses)
2607 {
2608         int rc;
2609
2610         read_lock(&policy_rwlock);
2611
2612         rc = -ENOMEM;
2613         *nclasses = policydb.p_classes.nprim;
2614         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2615         if (!*classes)
2616                 goto out;
2617
2618         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2619                         *classes);
2620         if (rc) {
2621                 int i;
2622                 for (i = 0; i < *nclasses; i++)
2623                         kfree((*classes)[i]);
2624                 kfree(*classes);
2625         }
2626
2627 out:
2628         read_unlock(&policy_rwlock);
2629         return rc;
2630 }
2631
2632 static int get_permissions_callback(void *k, void *d, void *args)
2633 {
2634         struct perm_datum *datum = d;
2635         char *name = k, **perms = args;
2636         int value = datum->value - 1;
2637
2638         perms[value] = kstrdup(name, GFP_ATOMIC);
2639         if (!perms[value])
2640                 return -ENOMEM;
2641
2642         return 0;
2643 }
2644
2645 int security_get_permissions(char *class, char ***perms, int *nperms)
2646 {
2647         int rc, i;
2648         struct class_datum *match;
2649
2650         read_lock(&policy_rwlock);
2651
2652         rc = -EINVAL;
2653         match = hashtab_search(policydb.p_classes.table, class);
2654         if (!match) {
2655                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2656                         __func__, class);
2657                 goto out;
2658         }
2659
2660         rc = -ENOMEM;
2661         *nperms = match->permissions.nprim;
2662         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2663         if (!*perms)
2664                 goto out;
2665
2666         if (match->comdatum) {
2667                 rc = hashtab_map(match->comdatum->permissions.table,
2668                                 get_permissions_callback, *perms);
2669                 if (rc)
2670                         goto err;
2671         }
2672
2673         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2674                         *perms);
2675         if (rc)
2676                 goto err;
2677
2678 out:
2679         read_unlock(&policy_rwlock);
2680         return rc;
2681
2682 err:
2683         read_unlock(&policy_rwlock);
2684         for (i = 0; i < *nperms; i++)
2685                 kfree((*perms)[i]);
2686         kfree(*perms);
2687         return rc;
2688 }
2689
2690 int security_get_reject_unknown(void)
2691 {
2692         return policydb.reject_unknown;
2693 }
2694
2695 int security_get_allow_unknown(void)
2696 {
2697         return policydb.allow_unknown;
2698 }
2699
2700 /**
2701  * security_policycap_supported - Check for a specific policy capability
2702  * @req_cap: capability
2703  *
2704  * Description:
2705  * This function queries the currently loaded policy to see if it supports the
2706  * capability specified by @req_cap.  Returns true (1) if the capability is
2707  * supported, false (0) if it isn't supported.
2708  *
2709  */
2710 int security_policycap_supported(unsigned int req_cap)
2711 {
2712         int rc;
2713
2714         read_lock(&policy_rwlock);
2715         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2716         read_unlock(&policy_rwlock);
2717
2718         return rc;
2719 }
2720
2721 struct selinux_audit_rule {
2722         u32 au_seqno;
2723         struct context au_ctxt;
2724 };
2725
2726 void selinux_audit_rule_free(void *vrule)
2727 {
2728         struct selinux_audit_rule *rule = vrule;
2729
2730         if (rule) {
2731                 context_destroy(&rule->au_ctxt);
2732                 kfree(rule);
2733         }
2734 }
2735
2736 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2737 {
2738         struct selinux_audit_rule *tmprule;
2739         struct role_datum *roledatum;
2740         struct type_datum *typedatum;
2741         struct user_datum *userdatum;
2742         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2743         int rc = 0;
2744
2745         *rule = NULL;
2746
2747         if (!ss_initialized)
2748                 return -EOPNOTSUPP;
2749
2750         switch (field) {
2751         case AUDIT_SUBJ_USER:
2752         case AUDIT_SUBJ_ROLE:
2753         case AUDIT_SUBJ_TYPE:
2754         case AUDIT_OBJ_USER:
2755         case AUDIT_OBJ_ROLE:
2756         case AUDIT_OBJ_TYPE:
2757                 /* only 'equals' and 'not equals' fit user, role, and type */
2758                 if (op != Audit_equal && op != Audit_not_equal)
2759                         return -EINVAL;
2760                 break;
2761         case AUDIT_SUBJ_SEN:
2762         case AUDIT_SUBJ_CLR:
2763         case AUDIT_OBJ_LEV_LOW:
2764         case AUDIT_OBJ_LEV_HIGH:
2765                 /* we do not allow a range, indicated by the presense of '-' */
2766                 if (strchr(rulestr, '-'))
2767                         return -EINVAL;
2768                 break;
2769         default:
2770                 /* only the above fields are valid */
2771                 return -EINVAL;
2772         }
2773
2774         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2775         if (!tmprule)
2776                 return -ENOMEM;
2777
2778         context_init(&tmprule->au_ctxt);
2779
2780         read_lock(&policy_rwlock);
2781
2782         tmprule->au_seqno = latest_granting;
2783
2784         switch (field) {
2785         case AUDIT_SUBJ_USER:
2786         case AUDIT_OBJ_USER:
2787                 rc = -EINVAL;
2788                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2789                 if (!userdatum)
2790                         goto out;
2791                 tmprule->au_ctxt.user = userdatum->value;
2792                 break;
2793         case AUDIT_SUBJ_ROLE:
2794         case AUDIT_OBJ_ROLE:
2795                 rc = -EINVAL;
2796                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2797                 if (!roledatum)
2798                         goto out;
2799                 tmprule->au_ctxt.role = roledatum->value;
2800                 break;
2801         case AUDIT_SUBJ_TYPE:
2802         case AUDIT_OBJ_TYPE:
2803                 rc = -EINVAL;
2804                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2805                 if (!typedatum)
2806                         goto out;
2807                 tmprule->au_ctxt.type = typedatum->value;
2808                 break;
2809         case AUDIT_SUBJ_SEN:
2810         case AUDIT_SUBJ_CLR:
2811         case AUDIT_OBJ_LEV_LOW:
2812         case AUDIT_OBJ_LEV_HIGH:
2813                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2814                 if (rc)
2815                         goto out;
2816                 break;
2817         }
2818         rc = 0;
2819 out:
2820         read_unlock(&policy_rwlock);
2821
2822         if (rc) {
2823                 selinux_audit_rule_free(tmprule);
2824                 tmprule = NULL;
2825         }
2826
2827         *rule = tmprule;
2828
2829         return rc;
2830 }
2831
2832 /* Check to see if the rule contains any selinux fields */
2833 int selinux_audit_rule_known(struct audit_krule *rule)
2834 {
2835         int i;
2836
2837         for (i = 0; i < rule->field_count; i++) {
2838                 struct audit_field *f = &rule->fields[i];
2839                 switch (f->type) {
2840                 case AUDIT_SUBJ_USER:
2841                 case AUDIT_SUBJ_ROLE:
2842                 case AUDIT_SUBJ_TYPE:
2843                 case AUDIT_SUBJ_SEN:
2844                 case AUDIT_SUBJ_CLR:
2845                 case AUDIT_OBJ_USER:
2846                 case AUDIT_OBJ_ROLE:
2847                 case AUDIT_OBJ_TYPE:
2848                 case AUDIT_OBJ_LEV_LOW:
2849                 case AUDIT_OBJ_LEV_HIGH:
2850                         return 1;
2851                 }
2852         }
2853
2854         return 0;
2855 }
2856
2857 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2858                              struct audit_context *actx)
2859 {
2860         struct context *ctxt;
2861         struct mls_level *level;
2862         struct selinux_audit_rule *rule = vrule;
2863         int match = 0;
2864
2865         if (!rule) {
2866                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2867                           "selinux_audit_rule_match: missing rule\n");
2868                 return -ENOENT;
2869         }
2870
2871         read_lock(&policy_rwlock);
2872
2873         if (rule->au_seqno < latest_granting) {
2874                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2875                           "selinux_audit_rule_match: stale rule\n");
2876                 match = -ESTALE;
2877                 goto out;
2878         }
2879
2880         ctxt = sidtab_search(&sidtab, sid);
2881         if (!ctxt) {
2882                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2883                           "selinux_audit_rule_match: unrecognized SID %d\n",
2884                           sid);
2885                 match = -ENOENT;
2886                 goto out;
2887         }
2888
2889         /* a field/op pair that is not caught here will simply fall through
2890            without a match */
2891         switch (field) {
2892         case AUDIT_SUBJ_USER:
2893         case AUDIT_OBJ_USER:
2894                 switch (op) {
2895                 case Audit_equal:
2896                         match = (ctxt->user == rule->au_ctxt.user);
2897                         break;
2898                 case Audit_not_equal:
2899                         match = (ctxt->user != rule->au_ctxt.user);
2900                         break;
2901                 }
2902                 break;
2903         case AUDIT_SUBJ_ROLE:
2904         case AUDIT_OBJ_ROLE:
2905                 switch (op) {
2906                 case Audit_equal:
2907                         match = (ctxt->role == rule->au_ctxt.role);
2908                         break;
2909                 case Audit_not_equal:
2910                         match = (ctxt->role != rule->au_ctxt.role);
2911                         break;
2912                 }
2913                 break;
2914         case AUDIT_SUBJ_TYPE:
2915         case AUDIT_OBJ_TYPE:
2916                 switch (op) {
2917                 case Audit_equal:
2918                         match = (ctxt->type == rule->au_ctxt.type);
2919                         break;
2920                 case Audit_not_equal:
2921                         match = (ctxt->type != rule->au_ctxt.type);
2922                         break;
2923                 }
2924                 break;
2925         case AUDIT_SUBJ_SEN:
2926         case AUDIT_SUBJ_CLR:
2927         case AUDIT_OBJ_LEV_LOW:
2928         case AUDIT_OBJ_LEV_HIGH:
2929                 level = ((field == AUDIT_SUBJ_SEN ||
2930                           field == AUDIT_OBJ_LEV_LOW) ?
2931                          &ctxt->range.level[0] : &ctxt->range.level[1]);
2932                 switch (op) {
2933                 case Audit_equal:
2934                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
2935                                              level);
2936                         break;
2937                 case Audit_not_equal:
2938                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2939                                               level);
2940                         break;
2941                 case Audit_lt:
2942                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2943                                                level) &&
2944                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
2945                                                level));
2946                         break;
2947                 case Audit_le:
2948                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
2949                                               level);
2950                         break;
2951                 case Audit_gt:
2952                         match = (mls_level_dom(level,
2953                                               &rule->au_ctxt.range.level[0]) &&
2954                                  !mls_level_eq(level,
2955                                                &rule->au_ctxt.range.level[0]));
2956                         break;
2957                 case Audit_ge:
2958                         match = mls_level_dom(level,
2959                                               &rule->au_ctxt.range.level[0]);
2960                         break;
2961                 }
2962         }
2963
2964 out:
2965         read_unlock(&policy_rwlock);
2966         return match;
2967 }
2968
2969 static int (*aurule_callback)(void) = audit_update_lsm_rules;
2970
2971 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2972                                u16 class, u32 perms, u32 *retained)
2973 {
2974         int err = 0;
2975
2976         if (event == AVC_CALLBACK_RESET && aurule_callback)
2977                 err = aurule_callback();
2978         return err;
2979 }
2980
2981 static int __init aurule_init(void)
2982 {
2983         int err;
2984
2985         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2986                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2987         if (err)
2988                 panic("avc_add_callback() failed, error %d\n", err);
2989
2990         return err;
2991 }
2992 __initcall(aurule_init);
2993
2994 #ifdef CONFIG_NETLABEL
2995 /**
2996  * security_netlbl_cache_add - Add an entry to the NetLabel cache
2997  * @secattr: the NetLabel packet security attributes
2998  * @sid: the SELinux SID
2999  *
3000  * Description:
3001  * Attempt to cache the context in @ctx, which was derived from the packet in
3002  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3003  * already been initialized.
3004  *
3005  */
3006 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3007                                       u32 sid)
3008 {
3009         u32 *sid_cache;
3010
3011         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3012         if (sid_cache == NULL)
3013                 return;
3014         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3015         if (secattr->cache == NULL) {
3016                 kfree(sid_cache);
3017                 return;
3018         }
3019
3020         *sid_cache = sid;
3021         secattr->cache->free = kfree;
3022         secattr->cache->data = sid_cache;
3023         secattr->flags |= NETLBL_SECATTR_CACHE;
3024 }
3025
3026 /**
3027  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3028  * @secattr: the NetLabel packet security attributes
3029  * @sid: the SELinux SID
3030  *
3031  * Description:
3032  * Convert the given NetLabel security attributes in @secattr into a
3033  * SELinux SID.  If the @secattr field does not contain a full SELinux
3034  * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
3035  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3036  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3037  * conversion for future lookups.  Returns zero on success, negative values on
3038  * failure.
3039  *
3040  */
3041 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3042                                    u32 *sid)
3043 {
3044         int rc = -EIDRM;
3045         struct context *ctx;
3046         struct context ctx_new;
3047
3048         if (!ss_initialized) {
3049                 *sid = SECSID_NULL;
3050                 return 0;
3051         }
3052
3053         read_lock(&policy_rwlock);
3054
3055         if (secattr->flags & NETLBL_SECATTR_CACHE) {
3056                 *sid = *(u32 *)secattr->cache->data;
3057                 rc = 0;
3058         } else if (secattr->flags & NETLBL_SECATTR_SECID) {
3059                 *sid = secattr->attr.secid;
3060                 rc = 0;
3061         } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3062                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3063                 if (ctx == NULL)
3064                         goto netlbl_secattr_to_sid_return;
3065
3066                 context_init(&ctx_new);
3067                 ctx_new.user = ctx->user;
3068                 ctx_new.role = ctx->role;
3069                 ctx_new.type = ctx->type;
3070                 mls_import_netlbl_lvl(&ctx_new, secattr);
3071                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3072                         if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3073                                                   secattr->attr.mls.cat) != 0)
3074                                 goto netlbl_secattr_to_sid_return;
3075                         memcpy(&ctx_new.range.level[1].cat,
3076                                &ctx_new.range.level[0].cat,
3077                                sizeof(ctx_new.range.level[0].cat));
3078                 }
3079                 if (mls_context_isvalid(&policydb, &ctx_new) != 1)
3080                         goto netlbl_secattr_to_sid_return_cleanup;
3081
3082                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3083                 if (rc != 0)
3084                         goto netlbl_secattr_to_sid_return_cleanup;
3085
3086                 security_netlbl_cache_add(secattr, *sid);
3087
3088                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3089         } else {
3090                 *sid = SECSID_NULL;
3091                 rc = 0;
3092         }
3093
3094 netlbl_secattr_to_sid_return:
3095         read_unlock(&policy_rwlock);
3096         return rc;
3097 netlbl_secattr_to_sid_return_cleanup:
3098         ebitmap_destroy(&ctx_new.range.level[0].cat);
3099         goto netlbl_secattr_to_sid_return;
3100 }
3101
3102 /**
3103  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3104  * @sid: the SELinux SID
3105  * @secattr: the NetLabel packet security attributes
3106  *
3107  * Description:
3108  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3109  * Returns zero on success, negative values on failure.
3110  *
3111  */
3112 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3113 {
3114         int rc;
3115         struct context *ctx;
3116
3117         if (!ss_initialized)
3118                 return 0;
3119
3120         read_lock(&policy_rwlock);
3121
3122         rc = -ENOENT;
3123         ctx = sidtab_search(&sidtab, sid);
3124         if (ctx == NULL)
3125                 goto out;
3126
3127         rc = -ENOMEM;
3128         secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
3129                                   GFP_ATOMIC);
3130         if (secattr->domain == NULL)
3131                 goto out;
3132
3133         secattr->attr.secid = sid;
3134         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3135         mls_export_netlbl_lvl(ctx, secattr);
3136         rc = mls_export_netlbl_cat(ctx, secattr);
3137 out:
3138         read_unlock(&policy_rwlock);
3139         return rc;
3140 }
3141 #endif /* CONFIG_NETLABEL */
3142
3143 /**
3144  * security_read_policy - read the policy.
3145  * @data: binary policy data
3146  * @len: length of data in bytes
3147  *
3148  */
3149 int security_read_policy(void **data, ssize_t *len)
3150 {
3151         int rc;
3152         struct policy_file fp;
3153
3154         if (!ss_initialized)
3155                 return -EINVAL;
3156
3157         *len = security_policydb_len();
3158
3159         *data = vmalloc_user(*len);
3160         if (!*data)
3161                 return -ENOMEM;
3162
3163         fp.data = *data;
3164         fp.len = *len;
3165
3166         read_lock(&policy_rwlock);
3167         rc = policydb_write(&policydb, &fp);
3168         read_unlock(&policy_rwlock);
3169
3170         if (rc)
3171                 return rc;
3172
3173         *len = (unsigned long)fp.data - (unsigned long)*data;
3174         return 0;
3175
3176 }