Pileus Git - ~andy/linux/blob - 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@paul-moore.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 int selinux_policycap_netpeer;
  74 int selinux_policycap_openperm;
  75
  76 static DEFINE_RWLOCK(policy_rwlock);
  77
  78 static struct sidtab sidtab;
  79 struct policydb policydb;
  80 int ss_initialized;
  81
  82 /*
  83  * The largest sequence number that has been used when
  84  * providing an access decision to the access vector cache.
  85  * The sequence number only changes when a policy change
  86  * occurs.
  87  */
  88 static u32 latest_granting;
  89
  90 /* Forward declaration. */
  91 static int context_struct_to_string(struct context *context, char **scontext,
  92                                     u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct context *scontext,
  95                                       struct context *tcontext,
  96                                       u16 tclass,
  97                                       struct av_decision *avd);
  98
  99 struct selinux_mapping {
 100         u16 value; /* policy value */
 101         unsigned num_perms;
 102         u32 perms[sizeof(u32) * 8];
 103 };
 104
 105 static struct selinux_mapping *current_mapping;
 106 static u16 current_mapping_size;
 107
 108 static int selinux_set_mapping(struct policydb *pol,
 109                                struct security_class_mapping *map,
 110                                struct selinux_mapping **out_map_p,
 111                                u16 *out_map_size)
 112 {
 113         struct selinux_mapping *out_map = NULL;
 114         size_t size = sizeof(struct selinux_mapping);
 115         u16 i, j;
 116         unsigned k;
 117         bool print_unknown_handle = false;
 118
 119         /* Find number of classes in the input mapping */
 120         if (!map)
 121                 return -EINVAL;
 122         i = 0;
 123         while (map[i].name)
 124                 i++;
 125
 126         /* Allocate space for the class records, plus one for class zero */
 127         out_map = kcalloc(++i, size, GFP_ATOMIC);
 128         if (!out_map)
 129                 return -ENOMEM;
 130
 131         /* Store the raw class and permission values */
 132         j = 0;
 133         while (map[j].name) {
 134                 struct security_class_mapping *p_in = map + (j++);
 135                 struct selinux_mapping *p_out = out_map + j;
 136
 137                 /* An empty class string skips ahead */
 138                 if (!strcmp(p_in->name, "")) {
 139                         p_out->num_perms = 0;
 140                         continue;
 141                 }
 142
 143                 p_out->value = string_to_security_class(pol, p_in->name);
 144                 if (!p_out->value) {
 145                         printk(KERN_INFO
 146                                "SELinux:  Class %s not defined in policy.\n",
 147                                p_in->name);
 148                         if (pol->reject_unknown)
 149                                 goto err;
 150                         p_out->num_perms = 0;
 151                         print_unknown_handle = true;
 152                         continue;
 153                 }
 154
 155                 k = 0;
 156                 while (p_in->perms && p_in->perms[k]) {
 157                         /* An empty permission string skips ahead */
 158                         if (!*p_in->perms[k]) {
 159                                 k++;
 160                                 continue;
 161                         }
 162                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 163                                                             p_in->perms[k]);
 164                         if (!p_out->perms[k]) {
 165                                 printk(KERN_INFO
 166                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 167                                        p_in->perms[k], p_in->name);
 168                                 if (pol->reject_unknown)
 169                                         goto err;
 170                                 print_unknown_handle = true;
 171                         }
 172
 173                         k++;
 174                 }
 175                 p_out->num_perms = k;
 176         }
 177
 178         if (print_unknown_handle)
 179                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 180                        pol->allow_unknown ? "allowed" : "denied");
 181
 182         *out_map_p = out_map;
 183         *out_map_size = i;
 184         return 0;
 185 err:
 186         kfree(out_map);
 187         return -EINVAL;
 188 }
 189
 190 /*
 191  * Get real, policy values from mapped values
 192  */
 193
 194 static u16 unmap_class(u16 tclass)
 195 {
 196         if (tclass < current_mapping_size)
 197                 return current_mapping[tclass].value;
 198
 199         return tclass;
 200 }
 201
 202 /*
 203  * Get kernel value for class from its policy value
 204  */
 205 static u16 map_class(u16 pol_value)
 206 {
 207         u16 i;
 208
 209         for (i = 1; i < current_mapping_size; i++) {
 210                 if (current_mapping[i].value == pol_value)
 211                         return i;
 212         }
 213
 214         return SECCLASS_NULL;
 215 }
 216
 217 static void map_decision(u16 tclass, struct av_decision *avd,
 218                          int allow_unknown)
 219 {
 220         if (tclass < current_mapping_size) {
 221                 unsigned i, n = current_mapping[tclass].num_perms;
 222                 u32 result;
 223
 224                 for (i = 0, result = 0; i < n; i++) {
 225                         if (avd->allowed & current_mapping[tclass].perms[i])
 226                                 result |= 1<<i;
 227                         if (allow_unknown && !current_mapping[tclass].perms[i])
 228                                 result |= 1<<i;
 229                 }
 230                 avd->allowed = result;
 231
 232                 for (i = 0, result = 0; i < n; i++)
 233                         if (avd->auditallow & current_mapping[tclass].perms[i])
 234                                 result |= 1<<i;
 235                 avd->auditallow = result;
 236
 237                 for (i = 0, result = 0; i < n; i++) {
 238                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 239                                 result |= 1<<i;
 240                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 241                                 result |= 1<<i;
 242                 }
 243                 /*
 244                  * In case the kernel has a bug and requests a permission
 245                  * between num_perms and the maximum permission number, we
 246                  * should audit that denial
 247                  */
 248                 for (; i < (sizeof(u32)*8); i++)
 249                         result |= 1<<i;
 250                 avd->auditdeny = result;
 251         }
 252 }
 253
 254 int security_mls_enabled(void)
 255 {
 256         return policydb.mls_enabled;
 257 }
 258
 259 /*
 260  * Return the boolean value of a constraint expression
 261  * when it is applied to the specified source and target
 262  * security contexts.
 263  *
 264  * xcontext is a special beast...  It is used by the validatetrans rules
 265  * only.  For these rules, scontext is the context before the transition,
 266  * tcontext is the context after the transition, and xcontext is the context
 267  * of the process performing the transition.  All other callers of
 268  * constraint_expr_eval should pass in NULL for xcontext.
 269  */
 270 static int constraint_expr_eval(struct context *scontext,
 271                                 struct context *tcontext,
 272                                 struct context *xcontext,
 273                                 struct constraint_expr *cexpr)
 274 {
 275         u32 val1, val2;
 276         struct context *c;
 277         struct role_datum *r1, *r2;
 278         struct mls_level *l1, *l2;
 279         struct constraint_expr *e;
 280         int s[CEXPR_MAXDEPTH];
 281         int sp = -1;
 282
 283         for (e = cexpr; e; e = e->next) {
 284                 switch (e->expr_type) {
 285                 case CEXPR_NOT:
 286                         BUG_ON(sp < 0);
 287                         s[sp] = !s[sp];
 288                         break;
 289                 case CEXPR_AND:
 290                         BUG_ON(sp < 1);
 291                         sp--;
 292                         s[sp] &= s[sp + 1];
 293                         break;
 294                 case CEXPR_OR:
 295                         BUG_ON(sp < 1);
 296                         sp--;
 297                         s[sp] |= s[sp + 1];
 298                         break;
 299                 case CEXPR_ATTR:
 300                         if (sp == (CEXPR_MAXDEPTH - 1))
 301                                 return 0;
 302                         switch (e->attr) {
 303                         case CEXPR_USER:
 304                                 val1 = scontext->user;
 305                                 val2 = tcontext->user;
 306                                 break;
 307                         case CEXPR_TYPE:
 308                                 val1 = scontext->type;
 309                                 val2 = tcontext->type;
 310                                 break;
 311                         case CEXPR_ROLE:
 312                                 val1 = scontext->role;
 313                                 val2 = tcontext->role;
 314                                 r1 = policydb.role_val_to_struct[val1 - 1];
 315                                 r2 = policydb.role_val_to_struct[val2 - 1];
 316                                 switch (e->op) {
 317                                 case CEXPR_DOM:
 318                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 319                                                                   val2 - 1);
 320                                         continue;
 321                                 case CEXPR_DOMBY:
 322                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 323                                                                   val1 - 1);
 324                                         continue;
 325                                 case CEXPR_INCOMP:
 326                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 327                                                                     val2 - 1) &&
 328                                                    !ebitmap_get_bit(&r2->dominates,
 329                                                                     val1 - 1));
 330                                         continue;
 331                                 default:
 332                                         break;
 333                                 }
 334                                 break;
 335                         case CEXPR_L1L2:
 336                                 l1 = &(scontext->range.level[0]);
 337                                 l2 = &(tcontext->range.level[0]);
 338                                 goto mls_ops;
 339                         case CEXPR_L1H2:
 340                                 l1 = &(scontext->range.level[0]);
 341                                 l2 = &(tcontext->range.level[1]);
 342                                 goto mls_ops;
 343                         case CEXPR_H1L2:
 344                                 l1 = &(scontext->range.level[1]);
 345                                 l2 = &(tcontext->range.level[0]);
 346                                 goto mls_ops;
 347                         case CEXPR_H1H2:
 348                                 l1 = &(scontext->range.level[1]);
 349                                 l2 = &(tcontext->range.level[1]);
 350                                 goto mls_ops;
 351                         case CEXPR_L1H1:
 352                                 l1 = &(scontext->range.level[0]);
 353                                 l2 = &(scontext->range.level[1]);
 354                                 goto mls_ops;
 355                         case CEXPR_L2H2:
 356                                 l1 = &(tcontext->range.level[0]);
 357                                 l2 = &(tcontext->range.level[1]);
 358                                 goto mls_ops;
 359 mls_ops:
 360                         switch (e->op) {
 361                         case CEXPR_EQ:
 362                                 s[++sp] = mls_level_eq(l1, l2);
 363                                 continue;
 364                         case CEXPR_NEQ:
 365                                 s[++sp] = !mls_level_eq(l1, l2);
 366                                 continue;
 367                         case CEXPR_DOM:
 368                                 s[++sp] = mls_level_dom(l1, l2);
 369                                 continue;
 370                         case CEXPR_DOMBY:
 371                                 s[++sp] = mls_level_dom(l2, l1);
 372                                 continue;
 373                         case CEXPR_INCOMP:
 374                                 s[++sp] = mls_level_incomp(l2, l1);
 375                                 continue;
 376                         default:
 377                                 BUG();
 378                                 return 0;
 379                         }
 380                         break;
 381                         default:
 382                                 BUG();
 383                                 return 0;
 384                         }
 385
 386                         switch (e->op) {
 387                         case CEXPR_EQ:
 388                                 s[++sp] = (val1 == val2);
 389                                 break;
 390                         case CEXPR_NEQ:
 391                                 s[++sp] = (val1 != val2);
 392                                 break;
 393                         default:
 394                                 BUG();
 395                                 return 0;
 396                         }
 397                         break;
 398                 case CEXPR_NAMES:
 399                         if (sp == (CEXPR_MAXDEPTH-1))
 400                                 return 0;
 401                         c = scontext;
 402                         if (e->attr & CEXPR_TARGET)
 403                                 c = tcontext;
 404                         else if (e->attr & CEXPR_XTARGET) {
 405                                 c = xcontext;
 406                                 if (!c) {
 407                                         BUG();
 408                                         return 0;
 409                                 }
 410                         }
 411                         if (e->attr & CEXPR_USER)
 412                                 val1 = c->user;
 413                         else if (e->attr & CEXPR_ROLE)
 414                                 val1 = c->role;
 415                         else if (e->attr & CEXPR_TYPE)
 416                                 val1 = c->type;
 417                         else {
 418                                 BUG();
 419                                 return 0;
 420                         }
 421
 422                         switch (e->op) {
 423                         case CEXPR_EQ:
 424                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 425                                 break;
 426                         case CEXPR_NEQ:
 427                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 428                                 break;
 429                         default:
 430                                 BUG();
 431                                 return 0;
 432                         }
 433                         break;
 434                 default:
 435                         BUG();
 436                         return 0;
 437                 }
 438         }
 439
 440         BUG_ON(sp != 0);
 441         return s[0];
 442 }
 443
 444 /*
 445  * security_dump_masked_av - dumps masked permissions during
 446  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 447  */
 448 static int dump_masked_av_helper(void *k, void *d, void *args)
 449 {
 450         struct perm_datum *pdatum = d;
 451         char **permission_names = args;
 452
 453         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 454
 455         permission_names[pdatum->value - 1] = (char *)k;
 456
 457         return 0;
 458 }
 459
 460 static void security_dump_masked_av(struct context *scontext,
 461                                     struct context *tcontext,
 462                                     u16 tclass,
 463                                     u32 permissions,
 464                                     const char *reason)
 465 {
 466         struct common_datum *common_dat;
 467         struct class_datum *tclass_dat;
 468         struct audit_buffer *ab;
 469         char *tclass_name;
 470         char *scontext_name = NULL;
 471         char *tcontext_name = NULL;
 472         char *permission_names[32];
 473         int index;
 474         u32 length;
 475         bool need_comma = false;
 476
 477         if (!permissions)
 478                 return;
 479
 480         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 481         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 482         common_dat = tclass_dat->comdatum;
 483
 484         /* init permission_names */
 485         if (common_dat &&
 486             hashtab_map(common_dat->permissions.table,
 487                         dump_masked_av_helper, permission_names) < 0)
 488                 goto out;
 489
 490         if (hashtab_map(tclass_dat->permissions.table,
 491                         dump_masked_av_helper, permission_names) < 0)
 492                 goto out;
 493
 494         /* get scontext/tcontext in text form */
 495         if (context_struct_to_string(scontext,
 496                                      &scontext_name, &length) < 0)
 497                 goto out;
 498
 499         if (context_struct_to_string(tcontext,
 500                                      &tcontext_name, &length) < 0)
 501                 goto out;
 502
 503         /* audit a message */
 504         ab = audit_log_start(current->audit_context,
 505                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 506         if (!ab)
 507                 goto out;
 508
 509         audit_log_format(ab, "op=security_compute_av reason=%s "
 510                          "scontext=%s tcontext=%s tclass=%s perms=",
 511                          reason, scontext_name, tcontext_name, tclass_name);
 512
 513         for (index = 0; index < 32; index++) {
 514                 u32 mask = (1 << index);
 515
 516                 if ((mask & permissions) == 0)
 517                         continue;
 518
 519                 audit_log_format(ab, "%s%s",
 520                                  need_comma ? "," : "",
 521                                  permission_names[index]
 522                                  ? permission_names[index] : "????");
 523                 need_comma = true;
 524         }
 525         audit_log_end(ab);
 526 out:
 527         /* release scontext/tcontext */
 528         kfree(tcontext_name);
 529         kfree(scontext_name);
 530
 531         return;
 532 }
 533
 534 /*
 535  * security_boundary_permission - drops violated permissions
 536  * on boundary constraint.
 537  */
 538 static void type_attribute_bounds_av(struct context *scontext,
 539                                      struct context *tcontext,
 540                                      u16 tclass,
 541                                      struct av_decision *avd)
 542 {
 543         struct context lo_scontext;
 544         struct context lo_tcontext;
 545         struct av_decision lo_avd;
 546         struct type_datum *source;
 547         struct type_datum *target;
 548         u32 masked = 0;
 549
 550         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 551                                     scontext->type - 1);
 552         BUG_ON(!source);
 553
 554         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 555                                     tcontext->type - 1);
 556         BUG_ON(!target);
 557
 558         if (source->bounds) {
 559                 memset(&lo_avd, 0, sizeof(lo_avd));
 560
 561                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 562                 lo_scontext.type = source->bounds;
 563
 564                 context_struct_compute_av(&lo_scontext,
 565                                           tcontext,
 566                                           tclass,
 567                                           &lo_avd);
 568                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 569                         return;         /* no masked permission */
 570                 masked = ~lo_avd.allowed & avd->allowed;
 571         }
 572
 573         if (target->bounds) {
 574                 memset(&lo_avd, 0, sizeof(lo_avd));
 575
 576                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 577                 lo_tcontext.type = target->bounds;
 578
 579                 context_struct_compute_av(scontext,
 580                                           &lo_tcontext,
 581                                           tclass,
 582                                           &lo_avd);
 583                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 584                         return;         /* no masked permission */
 585                 masked = ~lo_avd.allowed & avd->allowed;
 586         }
 587
 588         if (source->bounds && target->bounds) {
 589                 memset(&lo_avd, 0, sizeof(lo_avd));
 590                 /*
 591                  * lo_scontext and lo_tcontext are already
 592                  * set up.
 593                  */
 594
 595                 context_struct_compute_av(&lo_scontext,
 596                                           &lo_tcontext,
 597                                           tclass,
 598                                           &lo_avd);
 599                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 600                         return;         /* no masked permission */
 601                 masked = ~lo_avd.allowed & avd->allowed;
 602         }
 603
 604         if (masked) {
 605                 /* mask violated permissions */
 606                 avd->allowed &= ~masked;
 607
 608                 /* audit masked permissions */
 609                 security_dump_masked_av(scontext, tcontext,
 610                                         tclass, masked, "bounds");
 611         }
 612 }
 613
 614 /*
 615  * Compute access vectors based on a context structure pair for
 616  * the permissions in a particular class.
 617  */
 618 static void context_struct_compute_av(struct context *scontext,
 619                                       struct context *tcontext,
 620                                       u16 tclass,
 621                                       struct av_decision *avd)
 622 {
 623         struct constraint_node *constraint;
 624         struct role_allow *ra;
 625         struct avtab_key avkey;
 626         struct avtab_node *node;
 627         struct class_datum *tclass_datum;
 628         struct ebitmap *sattr, *tattr;
 629         struct ebitmap_node *snode, *tnode;
 630         unsigned int i, j;
 631
 632         avd->allowed = 0;
 633         avd->auditallow = 0;
 634         avd->auditdeny = 0xffffffff;
 635
 636         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 637                 if (printk_ratelimit())
 638                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 639                 return;
 640         }
 641
 642         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 643
 644         /*
 645          * If a specific type enforcement rule was defined for
 646          * this permission check, then use it.
 647          */
 648         avkey.target_class = tclass;
 649         avkey.specified = AVTAB_AV;
 650         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 651         BUG_ON(!sattr);
 652         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 653         BUG_ON(!tattr);
 654         ebitmap_for_each_positive_bit(sattr, snode, i) {
 655                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 656                         avkey.source_type = i + 1;
 657                         avkey.target_type = j + 1;
 658                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 659                              node;
 660                              node = avtab_search_node_next(node, avkey.specified)) {
 661                                 if (node->key.specified == AVTAB_ALLOWED)
 662                                         avd->allowed |= node->datum.data;
 663                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 664                                         avd->auditallow |= node->datum.data;
 665                                 else if (node->key.specified == AVTAB_AUDITDENY)
 666                                         avd->auditdeny &= node->datum.data;
 667                         }
 668
 669                         /* Check conditional av table for additional permissions */
 670                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 671
 672                 }
 673         }
 674
 675         /*
 676          * Remove any permissions prohibited by a constraint (this includes
 677          * the MLS policy).
 678          */
 679         constraint = tclass_datum->constraints;
 680         while (constraint) {
 681                 if ((constraint->permissions & (avd->allowed)) &&
 682                     !constraint_expr_eval(scontext, tcontext, NULL,
 683                                           constraint->expr)) {
 684                         avd->allowed &= ~(constraint->permissions);
 685                 }
 686                 constraint = constraint->next;
 687         }
 688
 689         /*
 690          * If checking process transition permission and the
 691          * role is changing, then check the (current_role, new_role)
 692          * pair.
 693          */
 694         if (tclass == policydb.process_class &&
 695             (avd->allowed & policydb.process_trans_perms) &&
 696             scontext->role != tcontext->role) {
 697                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 698                         if (scontext->role == ra->role &&
 699                             tcontext->role == ra->new_role)
 700                                 break;
 701                 }
 702                 if (!ra)
 703                         avd->allowed &= ~policydb.process_trans_perms;
 704         }
 705
 706         /*
 707          * If the given source and target types have boundary
 708          * constraint, lazy checks have to mask any violated
 709          * permission and notice it to userspace via audit.
 710          */
 711         type_attribute_bounds_av(scontext, tcontext,
 712                                  tclass, avd);
 713 }
 714
 715 static int security_validtrans_handle_fail(struct context *ocontext,
 716                                            struct context *ncontext,
 717                                            struct context *tcontext,
 718                                            u16 tclass)
 719 {
 720         char *o = NULL, *n = NULL, *t = NULL;
 721         u32 olen, nlen, tlen;
 722
 723         if (context_struct_to_string(ocontext, &o, &olen))
 724                 goto out;
 725         if (context_struct_to_string(ncontext, &n, &nlen))
 726                 goto out;
 727         if (context_struct_to_string(tcontext, &t, &tlen))
 728                 goto out;
 729         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 730                   "security_validate_transition:  denied for"
 731                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 732                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 733 out:
 734         kfree(o);
 735         kfree(n);
 736         kfree(t);
 737
 738         if (!selinux_enforcing)
 739                 return 0;
 740         return -EPERM;
 741 }
 742
 743 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 744                                  u16 orig_tclass)
 745 {
 746         struct context *ocontext;
 747         struct context *ncontext;
 748         struct context *tcontext;
 749         struct class_datum *tclass_datum;
 750         struct constraint_node *constraint;
 751         u16 tclass;
 752         int rc = 0;
 753
 754         if (!ss_initialized)
 755                 return 0;
 756
 757         read_lock(&policy_rwlock);
 758
 759         tclass = unmap_class(orig_tclass);
 760
 761         if (!tclass || tclass > policydb.p_classes.nprim) {
 762                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 763                         __func__, tclass);
 764                 rc = -EINVAL;
 765                 goto out;
 766         }
 767         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 768
 769         ocontext = sidtab_search(&sidtab, oldsid);
 770         if (!ocontext) {
 771                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 772                         __func__, oldsid);
 773                 rc = -EINVAL;
 774                 goto out;
 775         }
 776
 777         ncontext = sidtab_search(&sidtab, newsid);
 778         if (!ncontext) {
 779                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 780                         __func__, newsid);
 781                 rc = -EINVAL;
 782                 goto out;
 783         }
 784
 785         tcontext = sidtab_search(&sidtab, tasksid);
 786         if (!tcontext) {
 787                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 788                         __func__, tasksid);
 789                 rc = -EINVAL;
 790                 goto out;
 791         }
 792
 793         constraint = tclass_datum->validatetrans;
 794         while (constraint) {
 795                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 796                                           constraint->expr)) {
 797                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 798                                                              tcontext, tclass);
 799                         goto out;
 800                 }
 801                 constraint = constraint->next;
 802         }
 803
 804 out:
 805         read_unlock(&policy_rwlock);
 806         return rc;
 807 }
 808
 809 /*
 810  * security_bounded_transition - check whether the given
 811  * transition is directed to bounded, or not.
 812  * It returns 0, if @newsid is bounded by @oldsid.
 813  * Otherwise, it returns error code.
 814  *
 815  * @oldsid : current security identifier
 816  * @newsid : destinated security identifier
 817  */
 818 int security_bounded_transition(u32 old_sid, u32 new_sid)
 819 {
 820         struct context *old_context, *new_context;
 821         struct type_datum *type;
 822         int index;
 823         int rc;
 824
 825         read_lock(&policy_rwlock);
 826
 827         rc = -EINVAL;
 828         old_context = sidtab_search(&sidtab, old_sid);
 829         if (!old_context) {
 830                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 831                        __func__, old_sid);
 832                 goto out;
 833         }
 834
 835         rc = -EINVAL;
 836         new_context = sidtab_search(&sidtab, new_sid);
 837         if (!new_context) {
 838                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 839                        __func__, new_sid);
 840                 goto out;
 841         }
 842
 843         rc = 0;
 844         /* type/domain unchanged */
 845         if (old_context->type == new_context->type)
 846                 goto out;
 847
 848         index = new_context->type;
 849         while (true) {
 850                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 851                                           index - 1);
 852                 BUG_ON(!type);
 853
 854                 /* not bounded anymore */
 855                 rc = -EPERM;
 856                 if (!type->bounds)
 857                         break;
 858
 859                 /* @newsid is bounded by @oldsid */
 860                 rc = 0;
 861                 if (type->bounds == old_context->type)
 862                         break;
 863
 864                 index = type->bounds;
 865         }
 866
 867         if (rc) {
 868                 char *old_name = NULL;
 869                 char *new_name = NULL;
 870                 u32 length;
 871
 872                 if (!context_struct_to_string(old_context,
 873                                               &old_name, &length) &&
 874                     !context_struct_to_string(new_context,
 875                                               &new_name, &length)) {
 876                         audit_log(current->audit_context,
 877                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 878                                   "op=security_bounded_transition "
 879                                   "result=denied "
 880                                   "oldcontext=%s newcontext=%s",
 881                                   old_name, new_name);
 882                 }
 883                 kfree(new_name);
 884                 kfree(old_name);
 885         }
 886 out:
 887         read_unlock(&policy_rwlock);
 888
 889         return rc;
 890 }
 891
 892 static void avd_init(struct av_decision *avd)
 893 {
 894         avd->allowed = 0;
 895         avd->auditallow = 0;
 896         avd->auditdeny = 0xffffffff;
 897         avd->seqno = latest_granting;
 898         avd->flags = 0;
 899 }
 900
 901
 902 /**
 903  * security_compute_av - Compute access vector decisions.
 904  * @ssid: source security identifier
 905  * @tsid: target security identifier
 906  * @tclass: target security class
 907  * @avd: access vector decisions
 908  *
 909  * Compute a set of access vector decisions based on the
 910  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 911  */
 912 void security_compute_av(u32 ssid,
 913                          u32 tsid,
 914                          u16 orig_tclass,
 915                          struct av_decision *avd)
 916 {
 917         u16 tclass;
 918         struct context *scontext = NULL, *tcontext = NULL;
 919
 920         read_lock(&policy_rwlock);
 921         avd_init(avd);
 922         if (!ss_initialized)
 923                 goto allow;
 924
 925         scontext = sidtab_search(&sidtab, ssid);
 926         if (!scontext) {
 927                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 928                        __func__, ssid);
 929                 goto out;
 930         }
 931
 932         /* permissive domain? */
 933         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 934                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 935
 936         tcontext = sidtab_search(&sidtab, tsid);
 937         if (!tcontext) {
 938                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 939                        __func__, tsid);
 940                 goto out;
 941         }
 942
 943         tclass = unmap_class(orig_tclass);
 944         if (unlikely(orig_tclass && !tclass)) {
 945                 if (policydb.allow_unknown)
 946                         goto allow;
 947                 goto out;
 948         }
 949         context_struct_compute_av(scontext, tcontext, tclass, avd);
 950         map_decision(orig_tclass, avd, policydb.allow_unknown);
 951 out:
 952         read_unlock(&policy_rwlock);
 953         return;
 954 allow:
 955         avd->allowed = 0xffffffff;
 956         goto out;
 957 }
 958
 959 void security_compute_av_user(u32 ssid,
 960                               u32 tsid,
 961                               u16 tclass,
 962                               struct av_decision *avd)
 963 {
 964         struct context *scontext = NULL, *tcontext = NULL;
 965
 966         read_lock(&policy_rwlock);
 967         avd_init(avd);
 968         if (!ss_initialized)
 969                 goto allow;
 970
 971         scontext = sidtab_search(&sidtab, ssid);
 972         if (!scontext) {
 973                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 974                        __func__, ssid);
 975                 goto out;
 976         }
 977
 978         /* permissive domain? */
 979         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 980                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 981
 982         tcontext = sidtab_search(&sidtab, tsid);
 983         if (!tcontext) {
 984                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 985                        __func__, tsid);
 986                 goto out;
 987         }
 988
 989         if (unlikely(!tclass)) {
 990                 if (policydb.allow_unknown)
 991                         goto allow;
 992                 goto out;
 993         }
 994
 995         context_struct_compute_av(scontext, tcontext, tclass, avd);
 996  out:
 997         read_unlock(&policy_rwlock);
 998         return;
 999 allow:
1000         avd->allowed = 0xffffffff;
1001         goto out;
1002 }
1003
1004 /*
1005  * Write the security context string representation of
1006  * the context structure `context' into a dynamically
1007  * allocated string of the correct size.  Set `*scontext'
1008  * to point to this string and set `*scontext_len' to
1009  * the length of the string.
1010  */
1011 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1012 {
1013         char *scontextp;
1014
1015         if (scontext)
1016                 *scontext = NULL;
1017         *scontext_len = 0;
1018
1019         if (context->len) {
1020                 *scontext_len = context->len;
1021                 *scontext = kstrdup(context->str, GFP_ATOMIC);
1022                 if (!(*scontext))
1023                         return -ENOMEM;
1024                 return 0;
1025         }
1026
1027         /* Compute the size of the context. */
1028         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1029         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1030         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1031         *scontext_len += mls_compute_context_len(context);
1032
1033         if (!scontext)
1034                 return 0;
1035
1036         /* Allocate space for the context; caller must free this space. */
1037         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1038         if (!scontextp)
1039                 return -ENOMEM;
1040         *scontext = scontextp;
1041
1042         /*
1043          * Copy the user name, role name and type name into the context.
1044          */
1045         sprintf(scontextp, "%s:%s:%s",
1046                 sym_name(&policydb, SYM_USERS, context->user - 1),
1047                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1048                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1049         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1050                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1051                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1052
1053         mls_sid_to_context(context, &scontextp);
1054
1055         *scontextp = 0;
1056
1057         return 0;
1058 }
1059
1060 #include "initial_sid_to_string.h"
1061
1062 const char *security_get_initial_sid_context(u32 sid)
1063 {
1064         if (unlikely(sid > SECINITSID_NUM))
1065                 return NULL;
1066         return initial_sid_to_string[sid];
1067 }
1068
1069 static int security_sid_to_context_core(u32 sid, char **scontext,
1070                                         u32 *scontext_len, int force)
1071 {
1072         struct context *context;
1073         int rc = 0;
1074
1075         if (scontext)
1076                 *scontext = NULL;
1077         *scontext_len  = 0;
1078
1079         if (!ss_initialized) {
1080                 if (sid <= SECINITSID_NUM) {
1081                         char *scontextp;
1082
1083                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1084                         if (!scontext)
1085                                 goto out;
1086                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1087                         if (!scontextp) {
1088                                 rc = -ENOMEM;
1089                                 goto out;
1090                         }
1091                         strcpy(scontextp, initial_sid_to_string[sid]);
1092                         *scontext = scontextp;
1093                         goto out;
1094                 }
1095                 printk(KERN_ERR "SELinux: %s:  called before initial "
1096                        "load_policy on unknown SID %d\n", __func__, sid);
1097                 rc = -EINVAL;
1098                 goto out;
1099         }
1100         read_lock(&policy_rwlock);
1101         if (force)
1102                 context = sidtab_search_force(&sidtab, sid);
1103         else
1104                 context = sidtab_search(&sidtab, sid);
1105         if (!context) {
1106                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1107                         __func__, sid);
1108                 rc = -EINVAL;
1109                 goto out_unlock;
1110         }
1111         rc = context_struct_to_string(context, scontext, scontext_len);
1112 out_unlock:
1113         read_unlock(&policy_rwlock);
1114 out:
1115         return rc;
1116
1117 }
1118
1119 /**
1120  * security_sid_to_context - Obtain a context for a given SID.
1121  * @sid: security identifier, SID
1122  * @scontext: security context
1123  * @scontext_len: length in bytes
1124  *
1125  * Write the string representation of the context associated with @sid
1126  * into a dynamically allocated string of the correct size.  Set @scontext
1127  * to point to this string and set @scontext_len to the length of the string.
1128  */
1129 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1130 {
1131         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1132 }
1133
1134 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1135 {
1136         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1137 }
1138
1139 /*
1140  * Caveat:  Mutates scontext.
1141  */
1142 static int string_to_context_struct(struct policydb *pol,
1143                                     struct sidtab *sidtabp,
1144                                     char *scontext,
1145                                     u32 scontext_len,
1146                                     struct context *ctx,
1147                                     u32 def_sid)
1148 {
1149         struct role_datum *role;
1150         struct type_datum *typdatum;
1151         struct user_datum *usrdatum;
1152         char *scontextp, *p, oldc;
1153         int rc = 0;
1154
1155         context_init(ctx);
1156
1157         /* Parse the security context. */
1158
1159         rc = -EINVAL;
1160         scontextp = (char *) scontext;
1161
1162         /* Extract the user. */
1163         p = scontextp;
1164         while (*p && *p != ':')
1165                 p++;
1166
1167         if (*p == 0)
1168                 goto out;
1169
1170         *p++ = 0;
1171
1172         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1173         if (!usrdatum)
1174                 goto out;
1175
1176         ctx->user = usrdatum->value;
1177
1178         /* Extract role. */
1179         scontextp = p;
1180         while (*p && *p != ':')
1181                 p++;
1182
1183         if (*p == 0)
1184                 goto out;
1185
1186         *p++ = 0;
1187
1188         role = hashtab_search(pol->p_roles.table, scontextp);
1189         if (!role)
1190                 goto out;
1191         ctx->role = role->value;
1192
1193         /* Extract type. */
1194         scontextp = p;
1195         while (*p && *p != ':')
1196                 p++;
1197         oldc = *p;
1198         *p++ = 0;
1199
1200         typdatum = hashtab_search(pol->p_types.table, scontextp);
1201         if (!typdatum || typdatum->attribute)
1202                 goto out;
1203
1204         ctx->type = typdatum->value;
1205
1206         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1207         if (rc)
1208                 goto out;
1209
1210         rc = -EINVAL;
1211         if ((p - scontext) < scontext_len)
1212                 goto out;
1213
1214         /* Check the validity of the new context. */
1215         if (!policydb_context_isvalid(pol, ctx))
1216                 goto out;
1217         rc = 0;
1218 out:
1219         if (rc)
1220                 context_destroy(ctx);
1221         return rc;
1222 }
1223
1224 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1225                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1226                                         int force)
1227 {
1228         char *scontext2, *str = NULL;
1229         struct context context;
1230         int rc = 0;
1231
1232         if (!ss_initialized) {
1233                 int i;
1234
1235                 for (i = 1; i < SECINITSID_NUM; i++) {
1236                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1237                                 *sid = i;
1238                                 return 0;
1239                         }
1240                 }
1241                 *sid = SECINITSID_KERNEL;
1242                 return 0;
1243         }
1244         *sid = SECSID_NULL;
1245
1246         /* Copy the string so that we can modify the copy as we parse it. */
1247         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1248         if (!scontext2)
1249                 return -ENOMEM;
1250         memcpy(scontext2, scontext, scontext_len);
1251         scontext2[scontext_len] = 0;
1252
1253         if (force) {
1254                 /* Save another copy for storing in uninterpreted form */
1255                 rc = -ENOMEM;
1256                 str = kstrdup(scontext2, gfp_flags);
1257                 if (!str)
1258                         goto out;
1259         }
1260
1261         read_lock(&policy_rwlock);
1262         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1263                                       scontext_len, &context, def_sid);
1264         if (rc == -EINVAL && force) {
1265                 context.str = str;
1266                 context.len = scontext_len;
1267                 str = NULL;
1268         } else if (rc)
1269                 goto out_unlock;
1270         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1271         context_destroy(&context);
1272 out_unlock:
1273         read_unlock(&policy_rwlock);
1274 out:
1275         kfree(scontext2);
1276         kfree(str);
1277         return rc;
1278 }
1279
1280 /**
1281  * security_context_to_sid - Obtain a SID for a given security context.
1282  * @scontext: security context
1283  * @scontext_len: length in bytes
1284  * @sid: security identifier, SID
1285  *
1286  * Obtains a SID associated with the security context that
1287  * has the string representation specified by @scontext.
1288  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1289  * memory is available, or 0 on success.
1290  */
1291 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1292 {
1293         return security_context_to_sid_core(scontext, scontext_len,
1294                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1295 }
1296
1297 /**
1298  * security_context_to_sid_default - Obtain a SID for a given security context,
1299  * falling back to specified default if needed.
1300  *
1301  * @scontext: security context
1302  * @scontext_len: length in bytes
1303  * @sid: security identifier, SID
1304  * @def_sid: default SID to assign on error
1305  *
1306  * Obtains a SID associated with the security context that
1307  * has the string representation specified by @scontext.
1308  * The default SID is passed to the MLS layer to be used to allow
1309  * kernel labeling of the MLS field if the MLS field is not present
1310  * (for upgrading to MLS without full relabel).
1311  * Implicitly forces adding of the context even if it cannot be mapped yet.
1312  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1313  * memory is available, or 0 on success.
1314  */
1315 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1316                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1317 {
1318         return security_context_to_sid_core(scontext, scontext_len,
1319                                             sid, def_sid, gfp_flags, 1);
1320 }
1321
1322 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1323                                   u32 *sid)
1324 {
1325         return security_context_to_sid_core(scontext, scontext_len,
1326                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1327 }
1328
1329 static int compute_sid_handle_invalid_context(
1330         struct context *scontext,
1331         struct context *tcontext,
1332         u16 tclass,
1333         struct context *newcontext)
1334 {
1335         char *s = NULL, *t = NULL, *n = NULL;
1336         u32 slen, tlen, nlen;
1337
1338         if (context_struct_to_string(scontext, &s, &slen))
1339                 goto out;
1340         if (context_struct_to_string(tcontext, &t, &tlen))
1341                 goto out;
1342         if (context_struct_to_string(newcontext, &n, &nlen))
1343                 goto out;
1344         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1345                   "security_compute_sid:  invalid context %s"
1346                   " for scontext=%s"
1347                   " tcontext=%s"
1348                   " tclass=%s",
1349                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1350 out:
1351         kfree(s);
1352         kfree(t);
1353         kfree(n);
1354         if (!selinux_enforcing)
1355                 return 0;
1356         return -EACCES;
1357 }
1358
1359 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1360                                   u32 stype, u32 ttype, u16 tclass,
1361                                   const char *objname)
1362 {
1363         struct filename_trans ft;
1364         struct filename_trans_datum *otype;
1365
1366         /*
1367          * Most filename trans rules are going to live in specific directories
1368          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1369          * if the ttype does not contain any rules.
1370          */
1371         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1372                 return;
1373
1374         ft.stype = stype;
1375         ft.ttype = ttype;
1376         ft.tclass = tclass;
1377         ft.name = objname;
1378
1379         otype = hashtab_search(p->filename_trans, &ft);
1380         if (otype)
1381                 newcontext->type = otype->otype;
1382 }
1383
1384 static int security_compute_sid(u32 ssid,
1385                                 u32 tsid,
1386                                 u16 orig_tclass,
1387                                 u32 specified,
1388                                 const char *objname,
1389                                 u32 *out_sid,
1390                                 bool kern)
1391 {
1392         struct class_datum *cladatum = NULL;
1393         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1394         struct role_trans *roletr = NULL;
1395         struct avtab_key avkey;
1396         struct avtab_datum *avdatum;
1397         struct avtab_node *node;
1398         u16 tclass;
1399         int rc = 0;
1400         bool sock;
1401
1402         if (!ss_initialized) {
1403                 switch (orig_tclass) {
1404                 case SECCLASS_PROCESS: /* kernel value */
1405                         *out_sid = ssid;
1406                         break;
1407                 default:
1408                         *out_sid = tsid;
1409                         break;
1410                 }
1411                 goto out;
1412         }
1413
1414         context_init(&newcontext);
1415
1416         read_lock(&policy_rwlock);
1417
1418         if (kern) {
1419                 tclass = unmap_class(orig_tclass);
1420                 sock = security_is_socket_class(orig_tclass);
1421         } else {
1422                 tclass = orig_tclass;
1423                 sock = security_is_socket_class(map_class(tclass));
1424         }
1425
1426         scontext = sidtab_search(&sidtab, ssid);
1427         if (!scontext) {
1428                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1429                        __func__, ssid);
1430                 rc = -EINVAL;
1431                 goto out_unlock;
1432         }
1433         tcontext = sidtab_search(&sidtab, tsid);
1434         if (!tcontext) {
1435                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1436                        __func__, tsid);
1437                 rc = -EINVAL;
1438                 goto out_unlock;
1439         }
1440
1441         if (tclass && tclass <= policydb.p_classes.nprim)
1442                 cladatum = policydb.class_val_to_struct[tclass - 1];
1443
1444         /* Set the user identity. */
1445         switch (specified) {
1446         case AVTAB_TRANSITION:
1447         case AVTAB_CHANGE:
1448                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1449                         newcontext.user = tcontext->user;
1450                 } else {
1451                         /* notice this gets both DEFAULT_SOURCE and unset */
1452                         /* Use the process user identity. */
1453                         newcontext.user = scontext->user;
1454                 }
1455                 break;
1456         case AVTAB_MEMBER:
1457                 /* Use the related object owner. */
1458                 newcontext.user = tcontext->user;
1459                 break;
1460         }
1461
1462         /* Set the role to default values. */
1463         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1464                 newcontext.role = scontext->role;
1465         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1466                 newcontext.role = tcontext->role;
1467         } else {
1468                 if ((tclass == policydb.process_class) || (sock == true))
1469                         newcontext.role = scontext->role;
1470                 else
1471                         newcontext.role = OBJECT_R_VAL;
1472         }
1473
1474         /* Set the type to default values. */
1475         if ((tclass == policydb.process_class) || (sock == true)) {
1476                 /* Use the type of process. */
1477                 newcontext.type = scontext->type;
1478         } else {
1479                 /* Use the type of the related object. */
1480                 newcontext.type = tcontext->type;
1481         }
1482
1483         /* Look for a type transition/member/change rule. */
1484         avkey.source_type = scontext->type;
1485         avkey.target_type = tcontext->type;
1486         avkey.target_class = tclass;
1487         avkey.specified = specified;
1488         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1489
1490         /* If no permanent rule, also check for enabled conditional rules */
1491         if (!avdatum) {
1492                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1493                 for (; node; node = avtab_search_node_next(node, specified)) {
1494                         if (node->key.specified & AVTAB_ENABLED) {
1495                                 avdatum = &node->datum;
1496                                 break;
1497                         }
1498                 }
1499         }
1500
1501         if (avdatum) {
1502                 /* Use the type from the type transition/member/change rule. */
1503                 newcontext.type = avdatum->data;
1504         }
1505
1506         /* if we have a objname this is a file trans check so check those rules */
1507         if (objname)
1508                 filename_compute_type(&policydb, &newcontext, scontext->type,
1509                                       tcontext->type, tclass, objname);
1510
1511         /* Check for class-specific changes. */
1512         if (specified & AVTAB_TRANSITION) {
1513                 /* Look for a role transition rule. */
1514                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1515                         if ((roletr->role == scontext->role) &&
1516                             (roletr->type == tcontext->type) &&
1517                             (roletr->tclass == tclass)) {
1518                                 /* Use the role transition rule. */
1519                                 newcontext.role = roletr->new_role;
1520                                 break;
1521                         }
1522                 }
1523         }
1524
1525         /* Set the MLS attributes.
1526            This is done last because it may allocate memory. */
1527         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1528                              &newcontext, sock);
1529         if (rc)
1530                 goto out_unlock;
1531
1532         /* Check the validity of the context. */
1533         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1534                 rc = compute_sid_handle_invalid_context(scontext,
1535                                                         tcontext,
1536                                                         tclass,
1537                                                         &newcontext);
1538                 if (rc)
1539                         goto out_unlock;
1540         }
1541         /* Obtain the sid for the context. */
1542         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1543 out_unlock:
1544         read_unlock(&policy_rwlock);
1545         context_destroy(&newcontext);
1546 out:
1547         return rc;
1548 }
1549
1550 /**
1551  * security_transition_sid - Compute the SID for a new subject/object.
1552  * @ssid: source security identifier
1553  * @tsid: target security identifier
1554  * @tclass: target security class
1555  * @out_sid: security identifier for new subject/object
1556  *
1557  * Compute a SID to use for labeling a new subject or object in the
1558  * class @tclass based on a SID pair (@ssid, @tsid).
1559  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1560  * if insufficient memory is available, or %0 if the new SID was
1561  * computed successfully.
1562  */
1563 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1564                             const struct qstr *qstr, u32 *out_sid)
1565 {
1566         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1567                                     qstr ? qstr->name : NULL, out_sid, true);
1568 }
1569
1570 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1571                                  const char *objname, u32 *out_sid)
1572 {
1573         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1574                                     objname, out_sid, false);
1575 }
1576
1577 /**
1578  * security_member_sid - Compute the SID for member selection.
1579  * @ssid: source security identifier
1580  * @tsid: target security identifier
1581  * @tclass: target security class
1582  * @out_sid: security identifier for selected member
1583  *
1584  * Compute a SID to use when selecting a member of a polyinstantiated
1585  * object of class @tclass based on a SID pair (@ssid, @tsid).
1586  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1587  * if insufficient memory is available, or %0 if the SID was
1588  * computed successfully.
1589  */
1590 int security_member_sid(u32 ssid,
1591                         u32 tsid,
1592                         u16 tclass,
1593                         u32 *out_sid)
1594 {
1595         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1596                                     out_sid, false);
1597 }
1598
1599 /**
1600  * security_change_sid - Compute the SID for object relabeling.
1601  * @ssid: source security identifier
1602  * @tsid: target security identifier
1603  * @tclass: target security class
1604  * @out_sid: security identifier for selected member
1605  *
1606  * Compute a SID to use for relabeling an object of class @tclass
1607  * based on a SID pair (@ssid, @tsid).
1608  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1609  * if insufficient memory is available, or %0 if the SID was
1610  * computed successfully.
1611  */
1612 int security_change_sid(u32 ssid,
1613                         u32 tsid,
1614                         u16 tclass,
1615                         u32 *out_sid)
1616 {
1617         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1618                                     out_sid, false);
1619 }
1620
1621 /* Clone the SID into the new SID table. */
1622 static int clone_sid(u32 sid,
1623                      struct context *context,
1624                      void *arg)
1625 {
1626         struct sidtab *s = arg;
1627
1628         if (sid > SECINITSID_NUM)
1629                 return sidtab_insert(s, sid, context);
1630         else
1631                 return 0;
1632 }
1633
1634 static inline int convert_context_handle_invalid_context(struct context *context)
1635 {
1636         char *s;
1637         u32 len;
1638
1639         if (selinux_enforcing)
1640                 return -EINVAL;
1641
1642         if (!context_struct_to_string(context, &s, &len)) {
1643                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1644                 kfree(s);
1645         }
1646         return 0;
1647 }
1648
1649 struct convert_context_args {
1650         struct policydb *oldp;
1651         struct policydb *newp;
1652 };
1653
1654 /*
1655  * Convert the values in the security context
1656  * structure `c' from the values specified
1657  * in the policy `p->oldp' to the values specified
1658  * in the policy `p->newp'.  Verify that the
1659  * context is valid under the new policy.
1660  */
1661 static int convert_context(u32 key,
1662                            struct context *c,
1663                            void *p)
1664 {
1665         struct convert_context_args *args;
1666         struct context oldc;
1667         struct ocontext *oc;
1668         struct mls_range *range;
1669         struct role_datum *role;
1670         struct type_datum *typdatum;
1671         struct user_datum *usrdatum;
1672         char *s;
1673         u32 len;
1674         int rc = 0;
1675
1676         if (key <= SECINITSID_NUM)
1677                 goto out;
1678
1679         args = p;
1680
1681         if (c->str) {
1682                 struct context ctx;
1683
1684                 rc = -ENOMEM;
1685                 s = kstrdup(c->str, GFP_KERNEL);
1686                 if (!s)
1687                         goto out;
1688
1689                 rc = string_to_context_struct(args->newp, NULL, s,
1690                                               c->len, &ctx, SECSID_NULL);
1691                 kfree(s);
1692                 if (!rc) {
1693                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1694                                c->str);
1695                         /* Replace string with mapped representation. */
1696                         kfree(c->str);
1697                         memcpy(c, &ctx, sizeof(*c));
1698                         goto out;
1699                 } else if (rc == -EINVAL) {
1700                         /* Retain string representation for later mapping. */
1701                         rc = 0;
1702                         goto out;
1703                 } else {
1704                         /* Other error condition, e.g. ENOMEM. */
1705                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1706                                c->str, -rc);
1707                         goto out;
1708                 }
1709         }
1710
1711         rc = context_cpy(&oldc, c);
1712         if (rc)
1713                 goto out;
1714
1715         /* Convert the user. */
1716         rc = -EINVAL;
1717         usrdatum = hashtab_search(args->newp->p_users.table,
1718                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1719         if (!usrdatum)
1720                 goto bad;
1721         c->user = usrdatum->value;
1722
1723         /* Convert the role. */
1724         rc = -EINVAL;
1725         role = hashtab_search(args->newp->p_roles.table,
1726                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1727         if (!role)
1728                 goto bad;
1729         c->role = role->value;
1730
1731         /* Convert the type. */
1732         rc = -EINVAL;
1733         typdatum = hashtab_search(args->newp->p_types.table,
1734                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1735         if (!typdatum)
1736                 goto bad;
1737         c->type = typdatum->value;
1738
1739         /* Convert the MLS fields if dealing with MLS policies */
1740         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1741                 rc = mls_convert_context(args->oldp, args->newp, c);
1742                 if (rc)
1743                         goto bad;
1744         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1745                 /*
1746                  * Switching between MLS and non-MLS policy:
1747                  * free any storage used by the MLS fields in the
1748                  * context for all existing entries in the sidtab.
1749                  */
1750                 mls_context_destroy(c);
1751         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1752                 /*
1753                  * Switching between non-MLS and MLS policy:
1754                  * ensure that the MLS fields of the context for all
1755                  * existing entries in the sidtab are filled in with a
1756                  * suitable default value, likely taken from one of the
1757                  * initial SIDs.
1758                  */
1759                 oc = args->newp->ocontexts[OCON_ISID];
1760                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1761                         oc = oc->next;
1762                 rc = -EINVAL;
1763                 if (!oc) {
1764                         printk(KERN_ERR "SELinux:  unable to look up"
1765                                 " the initial SIDs list\n");
1766                         goto bad;
1767                 }
1768                 range = &oc->context[0].range;
1769                 rc = mls_range_set(c, range);
1770                 if (rc)
1771                         goto bad;
1772         }
1773
1774         /* Check the validity of the new context. */
1775         if (!policydb_context_isvalid(args->newp, c)) {
1776                 rc = convert_context_handle_invalid_context(&oldc);
1777                 if (rc)
1778                         goto bad;
1779         }
1780
1781         context_destroy(&oldc);
1782
1783         rc = 0;
1784 out:
1785         return rc;
1786 bad:
1787         /* Map old representation to string and save it. */
1788         rc = context_struct_to_string(&oldc, &s, &len);
1789         if (rc)
1790                 return rc;
1791         context_destroy(&oldc);
1792         context_destroy(c);
1793         c->str = s;
1794         c->len = len;
1795         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1796                c->str);
1797         rc = 0;
1798         goto out;
1799 }
1800
1801 static void security_load_policycaps(void)
1802 {
1803         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1804                                                   POLICYDB_CAPABILITY_NETPEER);
1805         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1806                                                   POLICYDB_CAPABILITY_OPENPERM);
1807 }
1808
1809 static int security_preserve_bools(struct policydb *p);
1810
1811 /**
1812  * security_load_policy - Load a security policy configuration.
1813  * @data: binary policy data
1814  * @len: length of data in bytes
1815  *
1816  * Load a new set of security policy configuration data,
1817  * validate it and convert the SID table as necessary.
1818  * This function will flush the access vector cache after
1819  * loading the new policy.
1820  */
1821 int security_load_policy(void *data, size_t len)
1822 {
1823         struct policydb oldpolicydb, newpolicydb;
1824         struct sidtab oldsidtab, newsidtab;
1825         struct selinux_mapping *oldmap, *map = NULL;
1826         struct convert_context_args args;
1827         u32 seqno;
1828         u16 map_size;
1829         int rc = 0;
1830         struct policy_file file = { data, len }, *fp = &file;
1831
1832         if (!ss_initialized) {
1833                 avtab_cache_init();
1834                 rc = policydb_read(&policydb, fp);
1835                 if (rc) {
1836                         avtab_cache_destroy();
1837                         return rc;
1838                 }
1839
1840                 policydb.len = len;
1841                 rc = selinux_set_mapping(&policydb, secclass_map,
1842                                          &current_mapping,
1843                                          &current_mapping_size);
1844                 if (rc) {
1845                         policydb_destroy(&policydb);
1846                         avtab_cache_destroy();
1847                         return rc;
1848                 }
1849
1850                 rc = policydb_load_isids(&policydb, &sidtab);
1851                 if (rc) {
1852                         policydb_destroy(&policydb);
1853                         avtab_cache_destroy();
1854                         return rc;
1855                 }
1856
1857                 security_load_policycaps();
1858                 ss_initialized = 1;
1859                 seqno = ++latest_granting;
1860                 selinux_complete_init();
1861                 avc_ss_reset(seqno);
1862                 selnl_notify_policyload(seqno);
1863                 selinux_status_update_policyload(seqno);
1864                 selinux_netlbl_cache_invalidate();
1865                 selinux_xfrm_notify_policyload();
1866                 return 0;
1867         }
1868
1869 #if 0
1870         sidtab_hash_eval(&sidtab, "sids");
1871 #endif
1872
1873         rc = policydb_read(&newpolicydb, fp);
1874         if (rc)
1875                 return rc;
1876
1877         newpolicydb.len = len;
1878         /* If switching between different policy types, log MLS status */
1879         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1880                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1881         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1882                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1883
1884         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1885         if (rc) {
1886                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1887                 policydb_destroy(&newpolicydb);
1888                 return rc;
1889         }
1890
1891         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1892         if (rc)
1893                 goto err;
1894
1895         rc = security_preserve_bools(&newpolicydb);
1896         if (rc) {
1897                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1898                 goto err;
1899         }
1900
1901         /* Clone the SID table. */
1902         sidtab_shutdown(&sidtab);
1903
1904         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1905         if (rc)
1906                 goto err;
1907
1908         /*
1909          * Convert the internal representations of contexts
1910          * in the new SID table.
1911          */
1912         args.oldp = &policydb;
1913         args.newp = &newpolicydb;
1914         rc = sidtab_map(&newsidtab, convert_context, &args);
1915         if (rc) {
1916                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1917                         " representation of contexts in the new SID"
1918                         " table\n");
1919                 goto err;
1920         }
1921
1922         /* Save the old policydb and SID table to free later. */
1923         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1924         sidtab_set(&oldsidtab, &sidtab);
1925
1926         /* Install the new policydb and SID table. */
1927         write_lock_irq(&policy_rwlock);
1928         memcpy(&policydb, &newpolicydb, sizeof policydb);
1929         sidtab_set(&sidtab, &newsidtab);
1930         security_load_policycaps();
1931         oldmap = current_mapping;
1932         current_mapping = map;
1933         current_mapping_size = map_size;
1934         seqno = ++latest_granting;
1935         write_unlock_irq(&policy_rwlock);
1936
1937         /* Free the old policydb and SID table. */
1938         policydb_destroy(&oldpolicydb);
1939         sidtab_destroy(&oldsidtab);
1940         kfree(oldmap);
1941
1942         avc_ss_reset(seqno);
1943         selnl_notify_policyload(seqno);
1944         selinux_status_update_policyload(seqno);
1945         selinux_netlbl_cache_invalidate();
1946         selinux_xfrm_notify_policyload();
1947
1948         return 0;
1949
1950 err:
1951         kfree(map);
1952         sidtab_destroy(&newsidtab);
1953         policydb_destroy(&newpolicydb);
1954         return rc;
1955
1956 }
1957
1958 size_t security_policydb_len(void)
1959 {
1960         size_t len;
1961
1962         read_lock(&policy_rwlock);
1963         len = policydb.len;
1964         read_unlock(&policy_rwlock);
1965
1966         return len;
1967 }
1968
1969 /**
1970  * security_port_sid - Obtain the SID for a port.
1971  * @protocol: protocol number
1972  * @port: port number
1973  * @out_sid: security identifier
1974  */
1975 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1976 {
1977         struct ocontext *c;
1978         int rc = 0;
1979
1980         read_lock(&policy_rwlock);
1981
1982         c = policydb.ocontexts[OCON_PORT];
1983         while (c) {
1984                 if (c->u.port.protocol == protocol &&
1985                     c->u.port.low_port <= port &&
1986                     c->u.port.high_port >= port)
1987                         break;
1988                 c = c->next;
1989         }
1990
1991         if (c) {
1992                 if (!c->sid[0]) {
1993                         rc = sidtab_context_to_sid(&sidtab,
1994                                                    &c->context[0],
1995                                                    &c->sid[0]);
1996                         if (rc)
1997                                 goto out;
1998                 }
1999                 *out_sid = c->sid[0];
2000         } else {
2001                 *out_sid = SECINITSID_PORT;
2002         }
2003
2004 out:
2005         read_unlock(&policy_rwlock);
2006         return rc;
2007 }
2008
2009 /**
2010  * security_netif_sid - Obtain the SID for a network interface.
2011  * @name: interface name
2012  * @if_sid: interface SID
2013  */
2014 int security_netif_sid(char *name, u32 *if_sid)
2015 {
2016         int rc = 0;
2017         struct ocontext *c;
2018
2019         read_lock(&policy_rwlock);
2020
2021         c = policydb.ocontexts[OCON_NETIF];
2022         while (c) {
2023                 if (strcmp(name, c->u.name) == 0)
2024                         break;
2025                 c = c->next;
2026         }
2027
2028         if (c) {
2029                 if (!c->sid[0] || !c->sid[1]) {
2030                         rc = sidtab_context_to_sid(&sidtab,
2031                                                   &c->context[0],
2032                                                   &c->sid[0]);
2033                         if (rc)
2034                                 goto out;
2035                         rc = sidtab_context_to_sid(&sidtab,
2036                                                    &c->context[1],
2037                                                    &c->sid[1]);
2038                         if (rc)
2039                                 goto out;
2040                 }
2041                 *if_sid = c->sid[0];
2042         } else
2043                 *if_sid = SECINITSID_NETIF;
2044
2045 out:
2046         read_unlock(&policy_rwlock);
2047         return rc;
2048 }
2049
2050 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2051 {
2052         int i, fail = 0;
2053
2054         for (i = 0; i < 4; i++)
2055                 if (addr[i] != (input[i] & mask[i])) {
2056                         fail = 1;
2057                         break;
2058                 }
2059
2060         return !fail;
2061 }
2062
2063 /**
2064  * security_node_sid - Obtain the SID for a node (host).
2065  * @domain: communication domain aka address family
2066  * @addrp: address
2067  * @addrlen: address length in bytes
2068  * @out_sid: security identifier
2069  */
2070 int security_node_sid(u16 domain,
2071                       void *addrp,
2072                       u32 addrlen,
2073                       u32 *out_sid)
2074 {
2075         int rc;
2076         struct ocontext *c;
2077
2078         read_lock(&policy_rwlock);
2079
2080         switch (domain) {
2081         case AF_INET: {
2082                 u32 addr;
2083
2084                 rc = -EINVAL;
2085                 if (addrlen != sizeof(u32))
2086                         goto out;
2087
2088                 addr = *((u32 *)addrp);
2089
2090                 c = policydb.ocontexts[OCON_NODE];
2091                 while (c) {
2092                         if (c->u.node.addr == (addr & c->u.node.mask))
2093                                 break;
2094                         c = c->next;
2095                 }
2096                 break;
2097         }
2098
2099         case AF_INET6:
2100                 rc = -EINVAL;
2101                 if (addrlen != sizeof(u64) * 2)
2102                         goto out;
2103                 c = policydb.ocontexts[OCON_NODE6];
2104                 while (c) {
2105                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2106                                                 c->u.node6.mask))
2107                                 break;
2108                         c = c->next;
2109                 }
2110                 break;
2111
2112         default:
2113                 rc = 0;
2114                 *out_sid = SECINITSID_NODE;
2115                 goto out;
2116         }
2117
2118         if (c) {
2119                 if (!c->sid[0]) {
2120                         rc = sidtab_context_to_sid(&sidtab,
2121                                                    &c->context[0],
2122                                                    &c->sid[0]);
2123                         if (rc)
2124                                 goto out;
2125                 }
2126                 *out_sid = c->sid[0];
2127         } else {
2128                 *out_sid = SECINITSID_NODE;
2129         }
2130
2131         rc = 0;
2132 out:
2133         read_unlock(&policy_rwlock);
2134         return rc;
2135 }
2136
2137 #define SIDS_NEL 25
2138
2139 /**
2140  * security_get_user_sids - Obtain reachable SIDs for a user.
2141  * @fromsid: starting SID
2142  * @username: username
2143  * @sids: array of reachable SIDs for user
2144  * @nel: number of elements in @sids
2145  *
2146  * Generate the set of SIDs for legal security contexts
2147  * for a given user that can be reached by @fromsid.
2148  * Set *@sids to point to a dynamically allocated
2149  * array containing the set of SIDs.  Set *@nel to the
2150  * number of elements in the array.
2151  */
2152
2153 int security_get_user_sids(u32 fromsid,
2154                            char *username,
2155                            u32 **sids,
2156                            u32 *nel)
2157 {
2158         struct context *fromcon, usercon;
2159         u32 *mysids = NULL, *mysids2, sid;
2160         u32 mynel = 0, maxnel = SIDS_NEL;
2161         struct user_datum *user;
2162         struct role_datum *role;
2163         struct ebitmap_node *rnode, *tnode;
2164         int rc = 0, i, j;
2165
2166         *sids = NULL;
2167         *nel = 0;
2168
2169         if (!ss_initialized)
2170                 goto out;
2171
2172         read_lock(&policy_rwlock);
2173
2174         context_init(&usercon);
2175
2176         rc = -EINVAL;
2177         fromcon = sidtab_search(&sidtab, fromsid);
2178         if (!fromcon)
2179                 goto out_unlock;
2180
2181         rc = -EINVAL;
2182         user = hashtab_search(policydb.p_users.table, username);
2183         if (!user)
2184                 goto out_unlock;
2185
2186         usercon.user = user->value;
2187
2188         rc = -ENOMEM;
2189         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2190         if (!mysids)
2191                 goto out_unlock;
2192
2193         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2194                 role = policydb.role_val_to_struct[i];
2195                 usercon.role = i + 1;
2196                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2197                         usercon.type = j + 1;
2198
2199                         if (mls_setup_user_range(fromcon, user, &usercon))
2200                                 continue;
2201
2202                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2203                         if (rc)
2204                                 goto out_unlock;
2205                         if (mynel < maxnel) {
2206                                 mysids[mynel++] = sid;
2207                         } else {
2208                                 rc = -ENOMEM;
2209                                 maxnel += SIDS_NEL;
2210                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2211                                 if (!mysids2)
2212                                         goto out_unlock;
2213                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2214                                 kfree(mysids);
2215                                 mysids = mysids2;
2216                                 mysids[mynel++] = sid;
2217                         }
2218                 }
2219         }
2220         rc = 0;
2221 out_unlock:
2222         read_unlock(&policy_rwlock);
2223         if (rc || !mynel) {
2224                 kfree(mysids);
2225                 goto out;
2226         }
2227
2228         rc = -ENOMEM;
2229         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2230         if (!mysids2) {
2231                 kfree(mysids);
2232                 goto out;
2233         }
2234         for (i = 0, j = 0; i < mynel; i++) {
2235                 struct av_decision dummy_avd;
2236                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2237                                           SECCLASS_PROCESS, /* kernel value */
2238                                           PROCESS__TRANSITION, AVC_STRICT,
2239                                           &dummy_avd);
2240                 if (!rc)
2241                         mysids2[j++] = mysids[i];
2242                 cond_resched();
2243         }
2244         rc = 0;
2245         kfree(mysids);
2246         *sids = mysids2;
2247         *nel = j;
2248 out:
2249         return rc;
2250 }
2251
2252 /**
2253  * security_genfs_sid - Obtain a SID for a file in a filesystem
2254  * @fstype: filesystem type
2255  * @path: path from root of mount
2256  * @sclass: file security class
2257  * @sid: SID for path
2258  *
2259  * Obtain a SID to use for a file in a filesystem that
2260  * cannot support xattr or use a fixed labeling behavior like
2261  * transition SIDs or task SIDs.
2262  */
2263 int security_genfs_sid(const char *fstype,
2264                        char *path,
2265                        u16 orig_sclass,
2266                        u32 *sid)
2267 {
2268         int len;
2269         u16 sclass;
2270         struct genfs *genfs;
2271         struct ocontext *c;
2272         int rc, cmp = 0;
2273
2274         while (path[0] == '/' && path[1] == '/')
2275                 path++;
2276
2277         read_lock(&policy_rwlock);
2278
2279         sclass = unmap_class(orig_sclass);
2280         *sid = SECINITSID_UNLABELED;
2281
2282         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2283                 cmp = strcmp(fstype, genfs->fstype);
2284                 if (cmp <= 0)
2285                         break;
2286         }
2287
2288         rc = -ENOENT;
2289         if (!genfs || cmp)
2290                 goto out;
2291
2292         for (c = genfs->head; c; c = c->next) {
2293                 len = strlen(c->u.name);
2294                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2295                     (strncmp(c->u.name, path, len) == 0))
2296                         break;
2297         }
2298
2299         rc = -ENOENT;
2300         if (!c)
2301                 goto out;
2302
2303         if (!c->sid[0]) {
2304                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2305                 if (rc)
2306                         goto out;
2307         }
2308
2309         *sid = c->sid[0];
2310         rc = 0;
2311 out:
2312         read_unlock(&policy_rwlock);
2313         return rc;
2314 }
2315
2316 /**
2317  * security_fs_use - Determine how to handle labeling for a filesystem.
2318  * @fstype: filesystem type
2319  * @behavior: labeling behavior
2320  * @sid: SID for filesystem (superblock)
2321  */
2322 int security_fs_use(
2323         const char *fstype,
2324         unsigned int *behavior,
2325         u32 *sid)
2326 {
2327         int rc = 0;
2328         struct ocontext *c;
2329
2330         read_lock(&policy_rwlock);
2331
2332         c = policydb.ocontexts[OCON_FSUSE];
2333         while (c) {
2334                 if (strcmp(fstype, c->u.name) == 0)
2335                         break;
2336                 c = c->next;
2337         }
2338
2339         if (c) {
2340                 *behavior = c->v.behavior;
2341                 if (!c->sid[0]) {
2342                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2343                                                    &c->sid[0]);
2344                         if (rc)
2345                                 goto out;
2346                 }
2347                 *sid = c->sid[0];
2348         } else {
2349                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2350                 if (rc) {
2351                         *behavior = SECURITY_FS_USE_NONE;
2352                         rc = 0;
2353                 } else {
2354                         *behavior = SECURITY_FS_USE_GENFS;
2355                 }
2356         }
2357
2358 out:
2359         read_unlock(&policy_rwlock);
2360         return rc;
2361 }
2362
2363 int security_get_bools(int *len, char ***names, int **values)
2364 {
2365         int i, rc;
2366
2367         read_lock(&policy_rwlock);
2368         *names = NULL;
2369         *values = NULL;
2370
2371         rc = 0;
2372         *len = policydb.p_bools.nprim;
2373         if (!*len)
2374                 goto out;
2375
2376         rc = -ENOMEM;
2377         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2378         if (!*names)
2379                 goto err;
2380
2381         rc = -ENOMEM;
2382         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2383         if (!*values)
2384                 goto err;
2385
2386         for (i = 0; i < *len; i++) {
2387                 size_t name_len;
2388
2389                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2390                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2391
2392                 rc = -ENOMEM;
2393                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2394                 if (!(*names)[i])
2395                         goto err;
2396
2397                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2398                 (*names)[i][name_len - 1] = 0;
2399         }
2400         rc = 0;
2401 out:
2402         read_unlock(&policy_rwlock);
2403         return rc;
2404 err:
2405         if (*names) {
2406                 for (i = 0; i < *len; i++)
2407                         kfree((*names)[i]);
2408         }
2409         kfree(*values);
2410         goto out;
2411 }
2412
2413
2414 int security_set_bools(int len, int *values)
2415 {
2416         int i, rc;
2417         int lenp, seqno = 0;
2418         struct cond_node *cur;
2419
2420         write_lock_irq(&policy_rwlock);
2421
2422         rc = -EFAULT;
2423         lenp = policydb.p_bools.nprim;
2424         if (len != lenp)
2425                 goto out;
2426
2427         for (i = 0; i < len; i++) {
2428                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2429                         audit_log(current->audit_context, GFP_ATOMIC,
2430                                 AUDIT_MAC_CONFIG_CHANGE,
2431                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2432                                 sym_name(&policydb, SYM_BOOLS, i),
2433                                 !!values[i],
2434                                 policydb.bool_val_to_struct[i]->state,
2435                                 audit_get_loginuid(current),
2436                                 audit_get_sessionid(current));
2437                 }
2438                 if (values[i])
2439                         policydb.bool_val_to_struct[i]->state = 1;
2440                 else
2441                         policydb.bool_val_to_struct[i]->state = 0;
2442         }
2443
2444         for (cur = policydb.cond_list; cur; cur = cur->next) {
2445                 rc = evaluate_cond_node(&policydb, cur);
2446                 if (rc)
2447                         goto out;
2448         }
2449
2450         seqno = ++latest_granting;
2451         rc = 0;
2452 out:
2453         write_unlock_irq(&policy_rwlock);
2454         if (!rc) {
2455                 avc_ss_reset(seqno);
2456                 selnl_notify_policyload(seqno);
2457                 selinux_status_update_policyload(seqno);
2458                 selinux_xfrm_notify_policyload();
2459         }
2460         return rc;
2461 }
2462
2463 int security_get_bool_value(int bool)
2464 {
2465         int rc;
2466         int len;
2467
2468         read_lock(&policy_rwlock);
2469
2470         rc = -EFAULT;
2471         len = policydb.p_bools.nprim;
2472         if (bool >= len)
2473                 goto out;
2474
2475         rc = policydb.bool_val_to_struct[bool]->state;
2476 out:
2477         read_unlock(&policy_rwlock);
2478         return rc;
2479 }
2480
2481 static int security_preserve_bools(struct policydb *p)
2482 {
2483         int rc, nbools = 0, *bvalues = NULL, i;
2484         char **bnames = NULL;
2485         struct cond_bool_datum *booldatum;
2486         struct cond_node *cur;
2487
2488         rc = security_get_bools(&nbools, &bnames, &bvalues);
2489         if (rc)
2490                 goto out;
2491         for (i = 0; i < nbools; i++) {
2492                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2493                 if (booldatum)
2494                         booldatum->state = bvalues[i];
2495         }
2496         for (cur = p->cond_list; cur; cur = cur->next) {
2497                 rc = evaluate_cond_node(p, cur);
2498                 if (rc)
2499                         goto out;
2500         }
2501
2502 out:
2503         if (bnames) {
2504                 for (i = 0; i < nbools; i++)
2505                         kfree(bnames[i]);
2506         }
2507         kfree(bnames);
2508         kfree(bvalues);
2509         return rc;
2510 }
2511
2512 /*
2513  * security_sid_mls_copy() - computes a new sid based on the given
2514  * sid and the mls portion of mls_sid.
2515  */
2516 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2517 {
2518         struct context *context1;
2519         struct context *context2;
2520         struct context newcon;
2521         char *s;
2522         u32 len;
2523         int rc;
2524
2525         rc = 0;
2526         if (!ss_initialized || !policydb.mls_enabled) {
2527                 *new_sid = sid;
2528                 goto out;
2529         }
2530
2531         context_init(&newcon);
2532
2533         read_lock(&policy_rwlock);
2534
2535         rc = -EINVAL;
2536         context1 = sidtab_search(&sidtab, sid);
2537         if (!context1) {
2538                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2539                         __func__, sid);
2540                 goto out_unlock;
2541         }
2542
2543         rc = -EINVAL;
2544         context2 = sidtab_search(&sidtab, mls_sid);
2545         if (!context2) {
2546                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2547                         __func__, mls_sid);
2548                 goto out_unlock;
2549         }
2550
2551         newcon.user = context1->user;
2552         newcon.role = context1->role;
2553         newcon.type = context1->type;
2554         rc = mls_context_cpy(&newcon, context2);
2555         if (rc)
2556                 goto out_unlock;
2557
2558         /* Check the validity of the new context. */
2559         if (!policydb_context_isvalid(&policydb, &newcon)) {
2560                 rc = convert_context_handle_invalid_context(&newcon);
2561                 if (rc) {
2562                         if (!context_struct_to_string(&newcon, &s, &len)) {
2563                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2564                                           "security_sid_mls_copy: invalid context %s", s);
2565                                 kfree(s);
2566                         }
2567                         goto out_unlock;
2568                 }
2569         }
2570
2571         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2572 out_unlock:
2573         read_unlock(&policy_rwlock);
2574         context_destroy(&newcon);
2575 out:
2576         return rc;
2577 }
2578
2579 /**
2580  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2581  * @nlbl_sid: NetLabel SID
2582  * @nlbl_type: NetLabel labeling protocol type
2583  * @xfrm_sid: XFRM SID
2584  *
2585  * Description:
2586  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2587  * resolved into a single SID it is returned via @peer_sid and the function
2588  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2589  * returns a negative value.  A table summarizing the behavior is below:
2590  *
2591  *                                 | function return |      @sid
2592  *   ------------------------------+-----------------+-----------------
2593  *   no peer labels                |        0        |    SECSID_NULL
2594  *   single peer label             |        0        |    <peer_label>
2595  *   multiple, consistent labels   |        0        |    <peer_label>
2596  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2597  *
2598  */
2599 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2600                                  u32 xfrm_sid,
2601                                  u32 *peer_sid)
2602 {
2603         int rc;
2604         struct context *nlbl_ctx;
2605         struct context *xfrm_ctx;
2606
2607         *peer_sid = SECSID_NULL;
2608
2609         /* handle the common (which also happens to be the set of easy) cases
2610          * right away, these two if statements catch everything involving a
2611          * single or absent peer SID/label */
2612         if (xfrm_sid == SECSID_NULL) {
2613                 *peer_sid = nlbl_sid;
2614                 return 0;
2615         }
2616         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2617          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2618          * is present */
2619         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2620                 *peer_sid = xfrm_sid;
2621                 return 0;
2622         }
2623
2624         /* we don't need to check ss_initialized here since the only way both
2625          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2626          * security server was initialized and ss_initialized was true */
2627         if (!policydb.mls_enabled)
2628                 return 0;
2629
2630         read_lock(&policy_rwlock);
2631
2632         rc = -EINVAL;
2633         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2634         if (!nlbl_ctx) {
2635                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2636                        __func__, nlbl_sid);
2637                 goto out;
2638         }
2639         rc = -EINVAL;
2640         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2641         if (!xfrm_ctx) {
2642                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2643                        __func__, xfrm_sid);
2644                 goto out;
2645         }
2646         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2647         if (rc)
2648                 goto out;
2649
2650         /* at present NetLabel SIDs/labels really only carry MLS
2651          * information so if the MLS portion of the NetLabel SID
2652          * matches the MLS portion of the labeled XFRM SID/label
2653          * then pass along the XFRM SID as it is the most
2654          * expressive */
2655         *peer_sid = xfrm_sid;
2656 out:
2657         read_unlock(&policy_rwlock);
2658         return rc;
2659 }
2660
2661 static int get_classes_callback(void *k, void *d, void *args)
2662 {
2663         struct class_datum *datum = d;
2664         char *name = k, **classes = args;
2665         int value = datum->value - 1;
2666
2667         classes[value] = kstrdup(name, GFP_ATOMIC);
2668         if (!classes[value])
2669                 return -ENOMEM;
2670
2671         return 0;
2672 }
2673
2674 int security_get_classes(char ***classes, int *nclasses)
2675 {
2676         int rc;
2677
2678         read_lock(&policy_rwlock);
2679
2680         rc = -ENOMEM;
2681         *nclasses = policydb.p_classes.nprim;
2682         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2683         if (!*classes)
2684                 goto out;
2685
2686         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2687                         *classes);
2688         if (rc) {
2689                 int i;
2690                 for (i = 0; i < *nclasses; i++)
2691                         kfree((*classes)[i]);
2692                 kfree(*classes);
2693         }
2694
2695 out:
2696         read_unlock(&policy_rwlock);
2697         return rc;
2698 }
2699
2700 static int get_permissions_callback(void *k, void *d, void *args)
2701 {
2702         struct perm_datum *datum = d;
2703         char *name = k, **perms = args;
2704         int value = datum->value - 1;
2705
2706         perms[value] = kstrdup(name, GFP_ATOMIC);
2707         if (!perms[value])
2708                 return -ENOMEM;
2709
2710         return 0;
2711 }
2712
2713 int security_get_permissions(char *class, char ***perms, int *nperms)
2714 {
2715         int rc, i;
2716         struct class_datum *match;
2717
2718         read_lock(&policy_rwlock);
2719
2720         rc = -EINVAL;
2721         match = hashtab_search(policydb.p_classes.table, class);
2722         if (!match) {
2723                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2724                         __func__, class);
2725                 goto out;
2726         }
2727
2728         rc = -ENOMEM;
2729         *nperms = match->permissions.nprim;
2730         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2731         if (!*perms)
2732                 goto out;
2733
2734         if (match->comdatum) {
2735                 rc = hashtab_map(match->comdatum->permissions.table,
2736                                 get_permissions_callback, *perms);
2737                 if (rc)
2738                         goto err;
2739         }
2740
2741         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2742                         *perms);
2743         if (rc)
2744                 goto err;
2745
2746 out:
2747         read_unlock(&policy_rwlock);
2748         return rc;
2749
2750 err:
2751         read_unlock(&policy_rwlock);
2752         for (i = 0; i < *nperms; i++)
2753                 kfree((*perms)[i]);
2754         kfree(*perms);
2755         return rc;
2756 }
2757
2758 int security_get_reject_unknown(void)
2759 {
2760         return policydb.reject_unknown;
2761 }
2762
2763 int security_get_allow_unknown(void)
2764 {
2765         return policydb.allow_unknown;
2766 }
2767
2768 /**
2769  * security_policycap_supported - Check for a specific policy capability
2770  * @req_cap: capability
2771  *
2772  * Description:
2773  * This function queries the currently loaded policy to see if it supports the
2774  * capability specified by @req_cap.  Returns true (1) if the capability is
2775  * supported, false (0) if it isn't supported.
2776  *
2777  */
2778 int security_policycap_supported(unsigned int req_cap)
2779 {
2780         int rc;
2781
2782         read_lock(&policy_rwlock);
2783         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2784         read_unlock(&policy_rwlock);
2785
2786         return rc;
2787 }
2788
2789 struct selinux_audit_rule {
2790         u32 au_seqno;
2791         struct context au_ctxt;
2792 };
2793
2794 void selinux_audit_rule_free(void *vrule)
2795 {
2796         struct selinux_audit_rule *rule = vrule;
2797
2798         if (rule) {
2799                 context_destroy(&rule->au_ctxt);
2800                 kfree(rule);
2801         }
2802 }
2803
2804 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2805 {
2806         struct selinux_audit_rule *tmprule;
2807         struct role_datum *roledatum;
2808         struct type_datum *typedatum;
2809         struct user_datum *userdatum;
2810         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2811         int rc = 0;
2812
2813         *rule = NULL;
2814
2815         if (!ss_initialized)
2816                 return -EOPNOTSUPP;
2817
2818         switch (field) {
2819         case AUDIT_SUBJ_USER:
2820         case AUDIT_SUBJ_ROLE:
2821         case AUDIT_SUBJ_TYPE:
2822         case AUDIT_OBJ_USER:
2823         case AUDIT_OBJ_ROLE:
2824         case AUDIT_OBJ_TYPE:
2825                 /* only 'equals' and 'not equals' fit user, role, and type */
2826                 if (op != Audit_equal && op != Audit_not_equal)
2827                         return -EINVAL;
2828                 break;
2829         case AUDIT_SUBJ_SEN:
2830         case AUDIT_SUBJ_CLR:
2831         case AUDIT_OBJ_LEV_LOW:
2832         case AUDIT_OBJ_LEV_HIGH:
2833                 /* we do not allow a range, indicated by the presence of '-' */
2834                 if (strchr(rulestr, '-'))
2835                         return -EINVAL;
2836                 break;
2837         default:
2838                 /* only the above fields are valid */
2839                 return -EINVAL;
2840         }
2841
2842         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2843         if (!tmprule)
2844                 return -ENOMEM;
2845
2846         context_init(&tmprule->au_ctxt);
2847
2848         read_lock(&policy_rwlock);
2849
2850         tmprule->au_seqno = latest_granting;
2851
2852         switch (field) {
2853         case AUDIT_SUBJ_USER:
2854         case AUDIT_OBJ_USER:
2855                 rc = -EINVAL;
2856                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2857                 if (!userdatum)
2858                         goto out;
2859                 tmprule->au_ctxt.user = userdatum->value;
2860                 break;
2861         case AUDIT_SUBJ_ROLE:
2862         case AUDIT_OBJ_ROLE:
2863                 rc = -EINVAL;
2864                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2865                 if (!roledatum)
2866                         goto out;
2867                 tmprule->au_ctxt.role = roledatum->value;
2868                 break;
2869         case AUDIT_SUBJ_TYPE:
2870         case AUDIT_OBJ_TYPE:
2871                 rc = -EINVAL;
2872                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2873                 if (!typedatum)
2874                         goto out;
2875                 tmprule->au_ctxt.type = typedatum->value;
2876                 break;
2877         case AUDIT_SUBJ_SEN:
2878         case AUDIT_SUBJ_CLR:
2879         case AUDIT_OBJ_LEV_LOW:
2880         case AUDIT_OBJ_LEV_HIGH:
2881                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2882                 if (rc)
2883                         goto out;
2884                 break;
2885         }
2886         rc = 0;
2887 out:
2888         read_unlock(&policy_rwlock);
2889
2890         if (rc) {
2891                 selinux_audit_rule_free(tmprule);
2892                 tmprule = NULL;
2893         }
2894
2895         *rule = tmprule;
2896
2897         return rc;
2898 }
2899
2900 /* Check to see if the rule contains any selinux fields */
2901 int selinux_audit_rule_known(struct audit_krule *rule)
2902 {
2903         int i;
2904
2905         for (i = 0; i < rule->field_count; i++) {
2906                 struct audit_field *f = &rule->fields[i];
2907                 switch (f->type) {
2908                 case AUDIT_SUBJ_USER:
2909                 case AUDIT_SUBJ_ROLE:
2910                 case AUDIT_SUBJ_TYPE:
2911                 case AUDIT_SUBJ_SEN:
2912                 case AUDIT_SUBJ_CLR:
2913                 case AUDIT_OBJ_USER:
2914                 case AUDIT_OBJ_ROLE:
2915                 case AUDIT_OBJ_TYPE:
2916                 case AUDIT_OBJ_LEV_LOW:
2917                 case AUDIT_OBJ_LEV_HIGH:
2918                         return 1;
2919                 }
2920         }
2921
2922         return 0;
2923 }
2924
2925 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2926                              struct audit_context *actx)
2927 {
2928         struct context *ctxt;
2929         struct mls_level *level;
2930         struct selinux_audit_rule *rule = vrule;
2931         int match = 0;
2932
2933         if (!rule) {
2934                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2935                           "selinux_audit_rule_match: missing rule\n");
2936                 return -ENOENT;
2937         }
2938
2939         read_lock(&policy_rwlock);
2940
2941         if (rule->au_seqno < latest_granting) {
2942                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2943                           "selinux_audit_rule_match: stale rule\n");
2944                 match = -ESTALE;
2945                 goto out;
2946         }
2947
2948         ctxt = sidtab_search(&sidtab, sid);
2949         if (!ctxt) {
2950                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2951                           "selinux_audit_rule_match: unrecognized SID %d\n",
2952                           sid);
2953                 match = -ENOENT;
2954                 goto out;
2955         }
2956
2957         /* a field/op pair that is not caught here will simply fall through
2958            without a match */
2959         switch (field) {
2960         case AUDIT_SUBJ_USER:
2961         case AUDIT_OBJ_USER:
2962                 switch (op) {
2963                 case Audit_equal:
2964                         match = (ctxt->user == rule->au_ctxt.user);
2965                         break;
2966                 case Audit_not_equal:
2967                         match = (ctxt->user != rule->au_ctxt.user);
2968                         break;
2969                 }
2970                 break;
2971         case AUDIT_SUBJ_ROLE:
2972         case AUDIT_OBJ_ROLE:
2973                 switch (op) {
2974                 case Audit_equal:
2975                         match = (ctxt->role == rule->au_ctxt.role);
2976                         break;
2977                 case Audit_not_equal:
2978                         match = (ctxt->role != rule->au_ctxt.role);
2979                         break;
2980                 }
2981                 break;
2982         case AUDIT_SUBJ_TYPE:
2983         case AUDIT_OBJ_TYPE:
2984                 switch (op) {
2985                 case Audit_equal:
2986                         match = (ctxt->type == rule->au_ctxt.type);
2987                         break;
2988                 case Audit_not_equal:
2989                         match = (ctxt->type != rule->au_ctxt.type);
2990                         break;
2991                 }
2992                 break;
2993         case AUDIT_SUBJ_SEN:
2994         case AUDIT_SUBJ_CLR:
2995         case AUDIT_OBJ_LEV_LOW:
2996         case AUDIT_OBJ_LEV_HIGH:
2997                 level = ((field == AUDIT_SUBJ_SEN ||
2998                           field == AUDIT_OBJ_LEV_LOW) ?
2999                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3000                 switch (op) {
3001                 case Audit_equal:
3002                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3003                                              level);
3004                         break;
3005                 case Audit_not_equal:
3006                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3007                                               level);
3008                         break;
3009                 case Audit_lt:
3010                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3011                                                level) &&
3012                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3013                                                level));
3014                         break;
3015                 case Audit_le:
3016                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3017                                               level);
3018                         break;
3019                 case Audit_gt:
3020                         match = (mls_level_dom(level,
3021                                               &rule->au_ctxt.range.level[0]) &&
3022                                  !mls_level_eq(level,
3023                                                &rule->au_ctxt.range.level[0]));
3024                         break;
3025                 case Audit_ge:
3026                         match = mls_level_dom(level,
3027                                               &rule->au_ctxt.range.level[0]);
3028                         break;
3029                 }
3030         }
3031
3032 out:
3033         read_unlock(&policy_rwlock);
3034         return match;
3035 }
3036
3037 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3038
3039 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3040                                u16 class, u32 perms, u32 *retained)
3041 {
3042         int err = 0;
3043
3044         if (event == AVC_CALLBACK_RESET && aurule_callback)
3045                 err = aurule_callback();
3046         return err;
3047 }
3048
3049 static int __init aurule_init(void)
3050 {
3051         int err;
3052
3053         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3054                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3055         if (err)
3056                 panic("avc_add_callback() failed, error %d\n", err);
3057
3058         return err;
3059 }
3060 __initcall(aurule_init);
3061
3062 #ifdef CONFIG_NETLABEL
3063 /**
3064  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3065  * @secattr: the NetLabel packet security attributes
3066  * @sid: the SELinux SID
3067  *
3068  * Description:
3069  * Attempt to cache the context in @ctx, which was derived from the packet in
3070  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3071  * already been initialized.
3072  *
3073  */
3074 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3075                                       u32 sid)
3076 {
3077         u32 *sid_cache;
3078
3079         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3080         if (sid_cache == NULL)
3081                 return;
3082         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3083         if (secattr->cache == NULL) {
3084                 kfree(sid_cache);
3085                 return;
3086         }
3087
3088         *sid_cache = sid;
3089         secattr->cache->free = kfree;
3090         secattr->cache->data = sid_cache;
3091         secattr->flags |= NETLBL_SECATTR_CACHE;
3092 }
3093
3094 /**
3095  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3096  * @secattr: the NetLabel packet security attributes
3097  * @sid: the SELinux SID
3098  *
3099  * Description:
3100  * Convert the given NetLabel security attributes in @secattr into a
3101  * SELinux SID.  If the @secattr field does not contain a full SELinux
3102  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3103  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3104  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3105  * conversion for future lookups.  Returns zero on success, negative values on
3106  * failure.
3107  *
3108  */
3109 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3110                                    u32 *sid)
3111 {
3112         int rc;
3113         struct context *ctx;
3114         struct context ctx_new;
3115
3116         if (!ss_initialized) {
3117                 *sid = SECSID_NULL;
3118                 return 0;
3119         }
3120
3121         read_lock(&policy_rwlock);
3122
3123         if (secattr->flags & NETLBL_SECATTR_CACHE)
3124                 *sid = *(u32 *)secattr->cache->data;
3125         else if (secattr->flags & NETLBL_SECATTR_SECID)
3126                 *sid = secattr->attr.secid;
3127         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3128                 rc = -EIDRM;
3129                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3130                 if (ctx == NULL)
3131                         goto out;
3132
3133                 context_init(&ctx_new);
3134                 ctx_new.user = ctx->user;
3135                 ctx_new.role = ctx->role;
3136                 ctx_new.type = ctx->type;
3137                 mls_import_netlbl_lvl(&ctx_new, secattr);
3138                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3139                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3140                                                    secattr->attr.mls.cat);
3141                         if (rc)
3142                                 goto out;
3143                         memcpy(&ctx_new.range.level[1].cat,
3144                                &ctx_new.range.level[0].cat,
3145                                sizeof(ctx_new.range.level[0].cat));
3146                 }
3147                 rc = -EIDRM;
3148                 if (!mls_context_isvalid(&policydb, &ctx_new))
3149                         goto out_free;
3150
3151                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3152                 if (rc)
3153                         goto out_free;
3154
3155                 security_netlbl_cache_add(secattr, *sid);
3156
3157                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3158         } else
3159                 *sid = SECSID_NULL;
3160
3161         read_unlock(&policy_rwlock);
3162         return 0;
3163 out_free:
3164         ebitmap_destroy(&ctx_new.range.level[0].cat);
3165 out:
3166         read_unlock(&policy_rwlock);
3167         return rc;
3168 }
3169
3170 /**
3171  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3172  * @sid: the SELinux SID
3173  * @secattr: the NetLabel packet security attributes
3174  *
3175  * Description:
3176  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3177  * Returns zero on success, negative values on failure.
3178  *
3179  */
3180 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3181 {
3182         int rc;
3183         struct context *ctx;
3184
3185         if (!ss_initialized)
3186                 return 0;
3187
3188         read_lock(&policy_rwlock);
3189
3190         rc = -ENOENT;
3191         ctx = sidtab_search(&sidtab, sid);
3192         if (ctx == NULL)
3193                 goto out;
3194
3195         rc = -ENOMEM;
3196         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3197                                   GFP_ATOMIC);
3198         if (secattr->domain == NULL)
3199                 goto out;
3200
3201         secattr->attr.secid = sid;
3202         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3203         mls_export_netlbl_lvl(ctx, secattr);
3204         rc = mls_export_netlbl_cat(ctx, secattr);
3205 out:
3206         read_unlock(&policy_rwlock);
3207         return rc;
3208 }
3209 #endif /* CONFIG_NETLABEL */
3210
3211 /**
3212  * security_read_policy - read the policy.
3213  * @data: binary policy data
3214  * @len: length of data in bytes
3215  *
3216  */
3217 int security_read_policy(void **data, size_t *len)
3218 {
3219         int rc;
3220         struct policy_file fp;
3221
3222         if (!ss_initialized)
3223                 return -EINVAL;
3224
3225         *len = security_policydb_len();
3226
3227         *data = vmalloc_user(*len);
3228         if (!*data)
3229                 return -ENOMEM;
3230
3231         fp.data = *data;
3232         fp.len = *len;
3233
3234         read_lock(&policy_rwlock);
3235         rc = policydb_write(&policydb, &fp);
3236         read_unlock(&policy_rwlock);
3237
3238         if (rc)
3239                 return rc;
3240
3241         *len = (unsigned long)fp.data - (unsigned long)*data;
3242         return 0;
3243
3244 }