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