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                 if (scontext) {
1022                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1023                         if (!(*scontext))
1024                                 return -ENOMEM;
1025                 }
1026                 return 0;
1027         }
1028
1029         /* Compute the size of the context. */
1030         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1031         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1032         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1033         *scontext_len += mls_compute_context_len(context);
1034
1035         if (!scontext)
1036                 return 0;
1037
1038         /* Allocate space for the context; caller must free this space. */
1039         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1040         if (!scontextp)
1041                 return -ENOMEM;
1042         *scontext = scontextp;
1043
1044         /*
1045          * Copy the user name, role name and type name into the context.
1046          */
1047         sprintf(scontextp, "%s:%s:%s",
1048                 sym_name(&policydb, SYM_USERS, context->user - 1),
1049                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1050                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1051         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1052                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1053                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1054
1055         mls_sid_to_context(context, &scontextp);
1056
1057         *scontextp = 0;
1058
1059         return 0;
1060 }
1061
1062 #include "initial_sid_to_string.h"
1063
1064 const char *security_get_initial_sid_context(u32 sid)
1065 {
1066         if (unlikely(sid > SECINITSID_NUM))
1067                 return NULL;
1068         return initial_sid_to_string[sid];
1069 }
1070
1071 static int security_sid_to_context_core(u32 sid, char **scontext,
1072                                         u32 *scontext_len, int force)
1073 {
1074         struct context *context;
1075         int rc = 0;
1076
1077         if (scontext)
1078                 *scontext = NULL;
1079         *scontext_len  = 0;
1080
1081         if (!ss_initialized) {
1082                 if (sid <= SECINITSID_NUM) {
1083                         char *scontextp;
1084
1085                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1086                         if (!scontext)
1087                                 goto out;
1088                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1089                         if (!scontextp) {
1090                                 rc = -ENOMEM;
1091                                 goto out;
1092                         }
1093                         strcpy(scontextp, initial_sid_to_string[sid]);
1094                         *scontext = scontextp;
1095                         goto out;
1096                 }
1097                 printk(KERN_ERR "SELinux: %s:  called before initial "
1098                        "load_policy on unknown SID %d\n", __func__, sid);
1099                 rc = -EINVAL;
1100                 goto out;
1101         }
1102         read_lock(&policy_rwlock);
1103         if (force)
1104                 context = sidtab_search_force(&sidtab, sid);
1105         else
1106                 context = sidtab_search(&sidtab, sid);
1107         if (!context) {
1108                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1109                         __func__, sid);
1110                 rc = -EINVAL;
1111                 goto out_unlock;
1112         }
1113         rc = context_struct_to_string(context, scontext, scontext_len);
1114 out_unlock:
1115         read_unlock(&policy_rwlock);
1116 out:
1117         return rc;
1118
1119 }
1120
1121 /**
1122  * security_sid_to_context - Obtain a context for a given SID.
1123  * @sid: security identifier, SID
1124  * @scontext: security context
1125  * @scontext_len: length in bytes
1126  *
1127  * Write the string representation of the context associated with @sid
1128  * into a dynamically allocated string of the correct size.  Set @scontext
1129  * to point to this string and set @scontext_len to the length of the string.
1130  */
1131 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1132 {
1133         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1134 }
1135
1136 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1137 {
1138         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1139 }
1140
1141 /*
1142  * Caveat:  Mutates scontext.
1143  */
1144 static int string_to_context_struct(struct policydb *pol,
1145                                     struct sidtab *sidtabp,
1146                                     char *scontext,
1147                                     u32 scontext_len,
1148                                     struct context *ctx,
1149                                     u32 def_sid)
1150 {
1151         struct role_datum *role;
1152         struct type_datum *typdatum;
1153         struct user_datum *usrdatum;
1154         char *scontextp, *p, oldc;
1155         int rc = 0;
1156
1157         context_init(ctx);
1158
1159         /* Parse the security context. */
1160
1161         rc = -EINVAL;
1162         scontextp = (char *) scontext;
1163
1164         /* Extract the user. */
1165         p = scontextp;
1166         while (*p && *p != ':')
1167                 p++;
1168
1169         if (*p == 0)
1170                 goto out;
1171
1172         *p++ = 0;
1173
1174         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1175         if (!usrdatum)
1176                 goto out;
1177
1178         ctx->user = usrdatum->value;
1179
1180         /* Extract role. */
1181         scontextp = p;
1182         while (*p && *p != ':')
1183                 p++;
1184
1185         if (*p == 0)
1186                 goto out;
1187
1188         *p++ = 0;
1189
1190         role = hashtab_search(pol->p_roles.table, scontextp);
1191         if (!role)
1192                 goto out;
1193         ctx->role = role->value;
1194
1195         /* Extract type. */
1196         scontextp = p;
1197         while (*p && *p != ':')
1198                 p++;
1199         oldc = *p;
1200         *p++ = 0;
1201
1202         typdatum = hashtab_search(pol->p_types.table, scontextp);
1203         if (!typdatum || typdatum->attribute)
1204                 goto out;
1205
1206         ctx->type = typdatum->value;
1207
1208         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1209         if (rc)
1210                 goto out;
1211
1212         rc = -EINVAL;
1213         if ((p - scontext) < scontext_len)
1214                 goto out;
1215
1216         /* Check the validity of the new context. */
1217         if (!policydb_context_isvalid(pol, ctx))
1218                 goto out;
1219         rc = 0;
1220 out:
1221         if (rc)
1222                 context_destroy(ctx);
1223         return rc;
1224 }
1225
1226 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1227                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1228                                         int force)
1229 {
1230         char *scontext2, *str = NULL;
1231         struct context context;
1232         int rc = 0;
1233
1234         if (!ss_initialized) {
1235                 int i;
1236
1237                 for (i = 1; i < SECINITSID_NUM; i++) {
1238                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1239                                 *sid = i;
1240                                 return 0;
1241                         }
1242                 }
1243                 *sid = SECINITSID_KERNEL;
1244                 return 0;
1245         }
1246         *sid = SECSID_NULL;
1247
1248         /* Copy the string so that we can modify the copy as we parse it. */
1249         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1250         if (!scontext2)
1251                 return -ENOMEM;
1252         memcpy(scontext2, scontext, scontext_len);
1253         scontext2[scontext_len] = 0;
1254
1255         if (force) {
1256                 /* Save another copy for storing in uninterpreted form */
1257                 rc = -ENOMEM;
1258                 str = kstrdup(scontext2, gfp_flags);
1259                 if (!str)
1260                         goto out;
1261         }
1262
1263         read_lock(&policy_rwlock);
1264         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1265                                       scontext_len, &context, def_sid);
1266         if (rc == -EINVAL && force) {
1267                 context.str = str;
1268                 context.len = scontext_len;
1269                 str = NULL;
1270         } else if (rc)
1271                 goto out_unlock;
1272         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1273         context_destroy(&context);
1274 out_unlock:
1275         read_unlock(&policy_rwlock);
1276 out:
1277         kfree(scontext2);
1278         kfree(str);
1279         return rc;
1280 }
1281
1282 /**
1283  * security_context_to_sid - Obtain a SID for a given security context.
1284  * @scontext: security context
1285  * @scontext_len: length in bytes
1286  * @sid: security identifier, SID
1287  *
1288  * Obtains a SID associated with the security context that
1289  * has the string representation specified by @scontext.
1290  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1291  * memory is available, or 0 on success.
1292  */
1293 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1294 {
1295         return security_context_to_sid_core(scontext, scontext_len,
1296                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1297 }
1298
1299 /**
1300  * security_context_to_sid_default - Obtain a SID for a given security context,
1301  * falling back to specified default if needed.
1302  *
1303  * @scontext: security context
1304  * @scontext_len: length in bytes
1305  * @sid: security identifier, SID
1306  * @def_sid: default SID to assign on error
1307  *
1308  * Obtains a SID associated with the security context that
1309  * has the string representation specified by @scontext.
1310  * The default SID is passed to the MLS layer to be used to allow
1311  * kernel labeling of the MLS field if the MLS field is not present
1312  * (for upgrading to MLS without full relabel).
1313  * Implicitly forces adding of the context even if it cannot be mapped yet.
1314  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1315  * memory is available, or 0 on success.
1316  */
1317 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1318                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1319 {
1320         return security_context_to_sid_core(scontext, scontext_len,
1321                                             sid, def_sid, gfp_flags, 1);
1322 }
1323
1324 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1325                                   u32 *sid)
1326 {
1327         return security_context_to_sid_core(scontext, scontext_len,
1328                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1329 }
1330
1331 static int compute_sid_handle_invalid_context(
1332         struct context *scontext,
1333         struct context *tcontext,
1334         u16 tclass,
1335         struct context *newcontext)
1336 {
1337         char *s = NULL, *t = NULL, *n = NULL;
1338         u32 slen, tlen, nlen;
1339
1340         if (context_struct_to_string(scontext, &s, &slen))
1341                 goto out;
1342         if (context_struct_to_string(tcontext, &t, &tlen))
1343                 goto out;
1344         if (context_struct_to_string(newcontext, &n, &nlen))
1345                 goto out;
1346         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1347                   "security_compute_sid:  invalid context %s"
1348                   " for scontext=%s"
1349                   " tcontext=%s"
1350                   " tclass=%s",
1351                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1352 out:
1353         kfree(s);
1354         kfree(t);
1355         kfree(n);
1356         if (!selinux_enforcing)
1357                 return 0;
1358         return -EACCES;
1359 }
1360
1361 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1362                                   u32 stype, u32 ttype, u16 tclass,
1363                                   const char *objname)
1364 {
1365         struct filename_trans ft;
1366         struct filename_trans_datum *otype;
1367
1368         /*
1369          * Most filename trans rules are going to live in specific directories
1370          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1371          * if the ttype does not contain any rules.
1372          */
1373         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1374                 return;
1375
1376         ft.stype = stype;
1377         ft.ttype = ttype;
1378         ft.tclass = tclass;
1379         ft.name = objname;
1380
1381         otype = hashtab_search(p->filename_trans, &ft);
1382         if (otype)
1383                 newcontext->type = otype->otype;
1384 }
1385
1386 static int security_compute_sid(u32 ssid,
1387                                 u32 tsid,
1388                                 u16 orig_tclass,
1389                                 u32 specified,
1390                                 const char *objname,
1391                                 u32 *out_sid,
1392                                 bool kern)
1393 {
1394         struct class_datum *cladatum = NULL;
1395         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1396         struct role_trans *roletr = NULL;
1397         struct avtab_key avkey;
1398         struct avtab_datum *avdatum;
1399         struct avtab_node *node;
1400         u16 tclass;
1401         int rc = 0;
1402         bool sock;
1403
1404         if (!ss_initialized) {
1405                 switch (orig_tclass) {
1406                 case SECCLASS_PROCESS: /* kernel value */
1407                         *out_sid = ssid;
1408                         break;
1409                 default:
1410                         *out_sid = tsid;
1411                         break;
1412                 }
1413                 goto out;
1414         }
1415
1416         context_init(&newcontext);
1417
1418         read_lock(&policy_rwlock);
1419
1420         if (kern) {
1421                 tclass = unmap_class(orig_tclass);
1422                 sock = security_is_socket_class(orig_tclass);
1423         } else {
1424                 tclass = orig_tclass;
1425                 sock = security_is_socket_class(map_class(tclass));
1426         }
1427
1428         scontext = sidtab_search(&sidtab, ssid);
1429         if (!scontext) {
1430                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1431                        __func__, ssid);
1432                 rc = -EINVAL;
1433                 goto out_unlock;
1434         }
1435         tcontext = sidtab_search(&sidtab, tsid);
1436         if (!tcontext) {
1437                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1438                        __func__, tsid);
1439                 rc = -EINVAL;
1440                 goto out_unlock;
1441         }
1442
1443         if (tclass && tclass <= policydb.p_classes.nprim)
1444                 cladatum = policydb.class_val_to_struct[tclass - 1];
1445
1446         /* Set the user identity. */
1447         switch (specified) {
1448         case AVTAB_TRANSITION:
1449         case AVTAB_CHANGE:
1450                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1451                         newcontext.user = tcontext->user;
1452                 } else {
1453                         /* notice this gets both DEFAULT_SOURCE and unset */
1454                         /* Use the process user identity. */
1455                         newcontext.user = scontext->user;
1456                 }
1457                 break;
1458         case AVTAB_MEMBER:
1459                 /* Use the related object owner. */
1460                 newcontext.user = tcontext->user;
1461                 break;
1462         }
1463
1464         /* Set the role to default values. */
1465         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1466                 newcontext.role = scontext->role;
1467         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1468                 newcontext.role = tcontext->role;
1469         } else {
1470                 if ((tclass == policydb.process_class) || (sock == true))
1471                         newcontext.role = scontext->role;
1472                 else
1473                         newcontext.role = OBJECT_R_VAL;
1474         }
1475
1476         /* Set the type to default values. */
1477         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1478                 newcontext.type = scontext->type;
1479         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1480                 newcontext.type = tcontext->type;
1481         } else {
1482                 if ((tclass == policydb.process_class) || (sock == true)) {
1483                         /* Use the type of process. */
1484                         newcontext.type = scontext->type;
1485                 } else {
1486                         /* Use the type of the related object. */
1487                         newcontext.type = tcontext->type;
1488                 }
1489         }
1490
1491         /* Look for a type transition/member/change rule. */
1492         avkey.source_type = scontext->type;
1493         avkey.target_type = tcontext->type;
1494         avkey.target_class = tclass;
1495         avkey.specified = specified;
1496         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1497
1498         /* If no permanent rule, also check for enabled conditional rules */
1499         if (!avdatum) {
1500                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1501                 for (; node; node = avtab_search_node_next(node, specified)) {
1502                         if (node->key.specified & AVTAB_ENABLED) {
1503                                 avdatum = &node->datum;
1504                                 break;
1505                         }
1506                 }
1507         }
1508
1509         if (avdatum) {
1510                 /* Use the type from the type transition/member/change rule. */
1511                 newcontext.type = avdatum->data;
1512         }
1513
1514         /* if we have a objname this is a file trans check so check those rules */
1515         if (objname)
1516                 filename_compute_type(&policydb, &newcontext, scontext->type,
1517                                       tcontext->type, tclass, objname);
1518
1519         /* Check for class-specific changes. */
1520         if (specified & AVTAB_TRANSITION) {
1521                 /* Look for a role transition rule. */
1522                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1523                         if ((roletr->role == scontext->role) &&
1524                             (roletr->type == tcontext->type) &&
1525                             (roletr->tclass == tclass)) {
1526                                 /* Use the role transition rule. */
1527                                 newcontext.role = roletr->new_role;
1528                                 break;
1529                         }
1530                 }
1531         }
1532
1533         /* Set the MLS attributes.
1534            This is done last because it may allocate memory. */
1535         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1536                              &newcontext, sock);
1537         if (rc)
1538                 goto out_unlock;
1539
1540         /* Check the validity of the context. */
1541         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1542                 rc = compute_sid_handle_invalid_context(scontext,
1543                                                         tcontext,
1544                                                         tclass,
1545                                                         &newcontext);
1546                 if (rc)
1547                         goto out_unlock;
1548         }
1549         /* Obtain the sid for the context. */
1550         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1551 out_unlock:
1552         read_unlock(&policy_rwlock);
1553         context_destroy(&newcontext);
1554 out:
1555         return rc;
1556 }
1557
1558 /**
1559  * security_transition_sid - Compute the SID for a new subject/object.
1560  * @ssid: source security identifier
1561  * @tsid: target security identifier
1562  * @tclass: target security class
1563  * @out_sid: security identifier for new subject/object
1564  *
1565  * Compute a SID to use for labeling a new subject or object in the
1566  * class @tclass based on a SID pair (@ssid, @tsid).
1567  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1568  * if insufficient memory is available, or %0 if the new SID was
1569  * computed successfully.
1570  */
1571 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1572                             const struct qstr *qstr, u32 *out_sid)
1573 {
1574         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1575                                     qstr ? qstr->name : NULL, out_sid, true);
1576 }
1577
1578 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1579                                  const char *objname, u32 *out_sid)
1580 {
1581         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1582                                     objname, out_sid, false);
1583 }
1584
1585 /**
1586  * security_member_sid - Compute the SID for member selection.
1587  * @ssid: source security identifier
1588  * @tsid: target security identifier
1589  * @tclass: target security class
1590  * @out_sid: security identifier for selected member
1591  *
1592  * Compute a SID to use when selecting a member of a polyinstantiated
1593  * object of class @tclass based on a SID pair (@ssid, @tsid).
1594  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1595  * if insufficient memory is available, or %0 if the SID was
1596  * computed successfully.
1597  */
1598 int security_member_sid(u32 ssid,
1599                         u32 tsid,
1600                         u16 tclass,
1601                         u32 *out_sid)
1602 {
1603         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1604                                     out_sid, false);
1605 }
1606
1607 /**
1608  * security_change_sid - Compute the SID for object relabeling.
1609  * @ssid: source security identifier
1610  * @tsid: target security identifier
1611  * @tclass: target security class
1612  * @out_sid: security identifier for selected member
1613  *
1614  * Compute a SID to use for relabeling an object of class @tclass
1615  * based on a SID pair (@ssid, @tsid).
1616  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1617  * if insufficient memory is available, or %0 if the SID was
1618  * computed successfully.
1619  */
1620 int security_change_sid(u32 ssid,
1621                         u32 tsid,
1622                         u16 tclass,
1623                         u32 *out_sid)
1624 {
1625         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1626                                     out_sid, false);
1627 }
1628
1629 /* Clone the SID into the new SID table. */
1630 static int clone_sid(u32 sid,
1631                      struct context *context,
1632                      void *arg)
1633 {
1634         struct sidtab *s = arg;
1635
1636         if (sid > SECINITSID_NUM)
1637                 return sidtab_insert(s, sid, context);
1638         else
1639                 return 0;
1640 }
1641
1642 static inline int convert_context_handle_invalid_context(struct context *context)
1643 {
1644         char *s;
1645         u32 len;
1646
1647         if (selinux_enforcing)
1648                 return -EINVAL;
1649
1650         if (!context_struct_to_string(context, &s, &len)) {
1651                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1652                 kfree(s);
1653         }
1654         return 0;
1655 }
1656
1657 struct convert_context_args {
1658         struct policydb *oldp;
1659         struct policydb *newp;
1660 };
1661
1662 /*
1663  * Convert the values in the security context
1664  * structure `c' from the values specified
1665  * in the policy `p->oldp' to the values specified
1666  * in the policy `p->newp'.  Verify that the
1667  * context is valid under the new policy.
1668  */
1669 static int convert_context(u32 key,
1670                            struct context *c,
1671                            void *p)
1672 {
1673         struct convert_context_args *args;
1674         struct context oldc;
1675         struct ocontext *oc;
1676         struct mls_range *range;
1677         struct role_datum *role;
1678         struct type_datum *typdatum;
1679         struct user_datum *usrdatum;
1680         char *s;
1681         u32 len;
1682         int rc = 0;
1683
1684         if (key <= SECINITSID_NUM)
1685                 goto out;
1686
1687         args = p;
1688
1689         if (c->str) {
1690                 struct context ctx;
1691
1692                 rc = -ENOMEM;
1693                 s = kstrdup(c->str, GFP_KERNEL);
1694                 if (!s)
1695                         goto out;
1696
1697                 rc = string_to_context_struct(args->newp, NULL, s,
1698                                               c->len, &ctx, SECSID_NULL);
1699                 kfree(s);
1700                 if (!rc) {
1701                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1702                                c->str);
1703                         /* Replace string with mapped representation. */
1704                         kfree(c->str);
1705                         memcpy(c, &ctx, sizeof(*c));
1706                         goto out;
1707                 } else if (rc == -EINVAL) {
1708                         /* Retain string representation for later mapping. */
1709                         rc = 0;
1710                         goto out;
1711                 } else {
1712                         /* Other error condition, e.g. ENOMEM. */
1713                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1714                                c->str, -rc);
1715                         goto out;
1716                 }
1717         }
1718
1719         rc = context_cpy(&oldc, c);
1720         if (rc)
1721                 goto out;
1722
1723         /* Convert the user. */
1724         rc = -EINVAL;
1725         usrdatum = hashtab_search(args->newp->p_users.table,
1726                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1727         if (!usrdatum)
1728                 goto bad;
1729         c->user = usrdatum->value;
1730
1731         /* Convert the role. */
1732         rc = -EINVAL;
1733         role = hashtab_search(args->newp->p_roles.table,
1734                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1735         if (!role)
1736                 goto bad;
1737         c->role = role->value;
1738
1739         /* Convert the type. */
1740         rc = -EINVAL;
1741         typdatum = hashtab_search(args->newp->p_types.table,
1742                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1743         if (!typdatum)
1744                 goto bad;
1745         c->type = typdatum->value;
1746
1747         /* Convert the MLS fields if dealing with MLS policies */
1748         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1749                 rc = mls_convert_context(args->oldp, args->newp, c);
1750                 if (rc)
1751                         goto bad;
1752         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1753                 /*
1754                  * Switching between MLS and non-MLS policy:
1755                  * free any storage used by the MLS fields in the
1756                  * context for all existing entries in the sidtab.
1757                  */
1758                 mls_context_destroy(c);
1759         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1760                 /*
1761                  * Switching between non-MLS and MLS policy:
1762                  * ensure that the MLS fields of the context for all
1763                  * existing entries in the sidtab are filled in with a
1764                  * suitable default value, likely taken from one of the
1765                  * initial SIDs.
1766                  */
1767                 oc = args->newp->ocontexts[OCON_ISID];
1768                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1769                         oc = oc->next;
1770                 rc = -EINVAL;
1771                 if (!oc) {
1772                         printk(KERN_ERR "SELinux:  unable to look up"
1773                                 " the initial SIDs list\n");
1774                         goto bad;
1775                 }
1776                 range = &oc->context[0].range;
1777                 rc = mls_range_set(c, range);
1778                 if (rc)
1779                         goto bad;
1780         }
1781
1782         /* Check the validity of the new context. */
1783         if (!policydb_context_isvalid(args->newp, c)) {
1784                 rc = convert_context_handle_invalid_context(&oldc);
1785                 if (rc)
1786                         goto bad;
1787         }
1788
1789         context_destroy(&oldc);
1790
1791         rc = 0;
1792 out:
1793         return rc;
1794 bad:
1795         /* Map old representation to string and save it. */
1796         rc = context_struct_to_string(&oldc, &s, &len);
1797         if (rc)
1798                 return rc;
1799         context_destroy(&oldc);
1800         context_destroy(c);
1801         c->str = s;
1802         c->len = len;
1803         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1804                c->str);
1805         rc = 0;
1806         goto out;
1807 }
1808
1809 static void security_load_policycaps(void)
1810 {
1811         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1812                                                   POLICYDB_CAPABILITY_NETPEER);
1813         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1814                                                   POLICYDB_CAPABILITY_OPENPERM);
1815 }
1816
1817 static int security_preserve_bools(struct policydb *p);
1818
1819 /**
1820  * security_load_policy - Load a security policy configuration.
1821  * @data: binary policy data
1822  * @len: length of data in bytes
1823  *
1824  * Load a new set of security policy configuration data,
1825  * validate it and convert the SID table as necessary.
1826  * This function will flush the access vector cache after
1827  * loading the new policy.
1828  */
1829 int security_load_policy(void *data, size_t len)
1830 {
1831         struct policydb oldpolicydb, newpolicydb;
1832         struct sidtab oldsidtab, newsidtab;
1833         struct selinux_mapping *oldmap, *map = NULL;
1834         struct convert_context_args args;
1835         u32 seqno;
1836         u16 map_size;
1837         int rc = 0;
1838         struct policy_file file = { data, len }, *fp = &file;
1839
1840         if (!ss_initialized) {
1841                 avtab_cache_init();
1842                 rc = policydb_read(&policydb, fp);
1843                 if (rc) {
1844                         avtab_cache_destroy();
1845                         return rc;
1846                 }
1847
1848                 policydb.len = len;
1849                 rc = selinux_set_mapping(&policydb, secclass_map,
1850                                          &current_mapping,
1851                                          &current_mapping_size);
1852                 if (rc) {
1853                         policydb_destroy(&policydb);
1854                         avtab_cache_destroy();
1855                         return rc;
1856                 }
1857
1858                 rc = policydb_load_isids(&policydb, &sidtab);
1859                 if (rc) {
1860                         policydb_destroy(&policydb);
1861                         avtab_cache_destroy();
1862                         return rc;
1863                 }
1864
1865                 security_load_policycaps();
1866                 ss_initialized = 1;
1867                 seqno = ++latest_granting;
1868                 selinux_complete_init();
1869                 avc_ss_reset(seqno);
1870                 selnl_notify_policyload(seqno);
1871                 selinux_status_update_policyload(seqno);
1872                 selinux_netlbl_cache_invalidate();
1873                 selinux_xfrm_notify_policyload();
1874                 return 0;
1875         }
1876
1877 #if 0
1878         sidtab_hash_eval(&sidtab, "sids");
1879 #endif
1880
1881         rc = policydb_read(&newpolicydb, fp);
1882         if (rc)
1883                 return rc;
1884
1885         newpolicydb.len = len;
1886         /* If switching between different policy types, log MLS status */
1887         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1888                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1889         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1890                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1891
1892         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1893         if (rc) {
1894                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1895                 policydb_destroy(&newpolicydb);
1896                 return rc;
1897         }
1898
1899         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1900         if (rc)
1901                 goto err;
1902
1903         rc = security_preserve_bools(&newpolicydb);
1904         if (rc) {
1905                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1906                 goto err;
1907         }
1908
1909         /* Clone the SID table. */
1910         sidtab_shutdown(&sidtab);
1911
1912         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1913         if (rc)
1914                 goto err;
1915
1916         /*
1917          * Convert the internal representations of contexts
1918          * in the new SID table.
1919          */
1920         args.oldp = &policydb;
1921         args.newp = &newpolicydb;
1922         rc = sidtab_map(&newsidtab, convert_context, &args);
1923         if (rc) {
1924                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1925                         " representation of contexts in the new SID"
1926                         " table\n");
1927                 goto err;
1928         }
1929
1930         /* Save the old policydb and SID table to free later. */
1931         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1932         sidtab_set(&oldsidtab, &sidtab);
1933
1934         /* Install the new policydb and SID table. */
1935         write_lock_irq(&policy_rwlock);
1936         memcpy(&policydb, &newpolicydb, sizeof policydb);
1937         sidtab_set(&sidtab, &newsidtab);
1938         security_load_policycaps();
1939         oldmap = current_mapping;
1940         current_mapping = map;
1941         current_mapping_size = map_size;
1942         seqno = ++latest_granting;
1943         write_unlock_irq(&policy_rwlock);
1944
1945         /* Free the old policydb and SID table. */
1946         policydb_destroy(&oldpolicydb);
1947         sidtab_destroy(&oldsidtab);
1948         kfree(oldmap);
1949
1950         avc_ss_reset(seqno);
1951         selnl_notify_policyload(seqno);
1952         selinux_status_update_policyload(seqno);
1953         selinux_netlbl_cache_invalidate();
1954         selinux_xfrm_notify_policyload();
1955
1956         return 0;
1957
1958 err:
1959         kfree(map);
1960         sidtab_destroy(&newsidtab);
1961         policydb_destroy(&newpolicydb);
1962         return rc;
1963
1964 }
1965
1966 size_t security_policydb_len(void)
1967 {
1968         size_t len;
1969
1970         read_lock(&policy_rwlock);
1971         len = policydb.len;
1972         read_unlock(&policy_rwlock);
1973
1974         return len;
1975 }
1976
1977 /**
1978  * security_port_sid - Obtain the SID for a port.
1979  * @protocol: protocol number
1980  * @port: port number
1981  * @out_sid: security identifier
1982  */
1983 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1984 {
1985         struct ocontext *c;
1986         int rc = 0;
1987
1988         read_lock(&policy_rwlock);
1989
1990         c = policydb.ocontexts[OCON_PORT];
1991         while (c) {
1992                 if (c->u.port.protocol == protocol &&
1993                     c->u.port.low_port <= port &&
1994                     c->u.port.high_port >= port)
1995                         break;
1996                 c = c->next;
1997         }
1998
1999         if (c) {
2000                 if (!c->sid[0]) {
2001                         rc = sidtab_context_to_sid(&sidtab,
2002                                                    &c->context[0],
2003                                                    &c->sid[0]);
2004                         if (rc)
2005                                 goto out;
2006                 }
2007                 *out_sid = c->sid[0];
2008         } else {
2009                 *out_sid = SECINITSID_PORT;
2010         }
2011
2012 out:
2013         read_unlock(&policy_rwlock);
2014         return rc;
2015 }
2016
2017 /**
2018  * security_netif_sid - Obtain the SID for a network interface.
2019  * @name: interface name
2020  * @if_sid: interface SID
2021  */
2022 int security_netif_sid(char *name, u32 *if_sid)
2023 {
2024         int rc = 0;
2025         struct ocontext *c;
2026
2027         read_lock(&policy_rwlock);
2028
2029         c = policydb.ocontexts[OCON_NETIF];
2030         while (c) {
2031                 if (strcmp(name, c->u.name) == 0)
2032                         break;
2033                 c = c->next;
2034         }
2035
2036         if (c) {
2037                 if (!c->sid[0] || !c->sid[1]) {
2038                         rc = sidtab_context_to_sid(&sidtab,
2039                                                   &c->context[0],
2040                                                   &c->sid[0]);
2041                         if (rc)
2042                                 goto out;
2043                         rc = sidtab_context_to_sid(&sidtab,
2044                                                    &c->context[1],
2045                                                    &c->sid[1]);
2046                         if (rc)
2047                                 goto out;
2048                 }
2049                 *if_sid = c->sid[0];
2050         } else
2051                 *if_sid = SECINITSID_NETIF;
2052
2053 out:
2054         read_unlock(&policy_rwlock);
2055         return rc;
2056 }
2057
2058 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2059 {
2060         int i, fail = 0;
2061
2062         for (i = 0; i < 4; i++)
2063                 if (addr[i] != (input[i] & mask[i])) {
2064                         fail = 1;
2065                         break;
2066                 }
2067
2068         return !fail;
2069 }
2070
2071 /**
2072  * security_node_sid - Obtain the SID for a node (host).
2073  * @domain: communication domain aka address family
2074  * @addrp: address
2075  * @addrlen: address length in bytes
2076  * @out_sid: security identifier
2077  */
2078 int security_node_sid(u16 domain,
2079                       void *addrp,
2080                       u32 addrlen,
2081                       u32 *out_sid)
2082 {
2083         int rc;
2084         struct ocontext *c;
2085
2086         read_lock(&policy_rwlock);
2087
2088         switch (domain) {
2089         case AF_INET: {
2090                 u32 addr;
2091
2092                 rc = -EINVAL;
2093                 if (addrlen != sizeof(u32))
2094                         goto out;
2095
2096                 addr = *((u32 *)addrp);
2097
2098                 c = policydb.ocontexts[OCON_NODE];
2099                 while (c) {
2100                         if (c->u.node.addr == (addr & c->u.node.mask))
2101                                 break;
2102                         c = c->next;
2103                 }
2104                 break;
2105         }
2106
2107         case AF_INET6:
2108                 rc = -EINVAL;
2109                 if (addrlen != sizeof(u64) * 2)
2110                         goto out;
2111                 c = policydb.ocontexts[OCON_NODE6];
2112                 while (c) {
2113                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2114                                                 c->u.node6.mask))
2115                                 break;
2116                         c = c->next;
2117                 }
2118                 break;
2119
2120         default:
2121                 rc = 0;
2122                 *out_sid = SECINITSID_NODE;
2123                 goto out;
2124         }
2125
2126         if (c) {
2127                 if (!c->sid[0]) {
2128                         rc = sidtab_context_to_sid(&sidtab,
2129                                                    &c->context[0],
2130                                                    &c->sid[0]);
2131                         if (rc)
2132                                 goto out;
2133                 }
2134                 *out_sid = c->sid[0];
2135         } else {
2136                 *out_sid = SECINITSID_NODE;
2137         }
2138
2139         rc = 0;
2140 out:
2141         read_unlock(&policy_rwlock);
2142         return rc;
2143 }
2144
2145 #define SIDS_NEL 25
2146
2147 /**
2148  * security_get_user_sids - Obtain reachable SIDs for a user.
2149  * @fromsid: starting SID
2150  * @username: username
2151  * @sids: array of reachable SIDs for user
2152  * @nel: number of elements in @sids
2153  *
2154  * Generate the set of SIDs for legal security contexts
2155  * for a given user that can be reached by @fromsid.
2156  * Set *@sids to point to a dynamically allocated
2157  * array containing the set of SIDs.  Set *@nel to the
2158  * number of elements in the array.
2159  */
2160
2161 int security_get_user_sids(u32 fromsid,
2162                            char *username,
2163                            u32 **sids,
2164                            u32 *nel)
2165 {
2166         struct context *fromcon, usercon;
2167         u32 *mysids = NULL, *mysids2, sid;
2168         u32 mynel = 0, maxnel = SIDS_NEL;
2169         struct user_datum *user;
2170         struct role_datum *role;
2171         struct ebitmap_node *rnode, *tnode;
2172         int rc = 0, i, j;
2173
2174         *sids = NULL;
2175         *nel = 0;
2176
2177         if (!ss_initialized)
2178                 goto out;
2179
2180         read_lock(&policy_rwlock);
2181
2182         context_init(&usercon);
2183
2184         rc = -EINVAL;
2185         fromcon = sidtab_search(&sidtab, fromsid);
2186         if (!fromcon)
2187                 goto out_unlock;
2188
2189         rc = -EINVAL;
2190         user = hashtab_search(policydb.p_users.table, username);
2191         if (!user)
2192                 goto out_unlock;
2193
2194         usercon.user = user->value;
2195
2196         rc = -ENOMEM;
2197         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2198         if (!mysids)
2199                 goto out_unlock;
2200
2201         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2202                 role = policydb.role_val_to_struct[i];
2203                 usercon.role = i + 1;
2204                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2205                         usercon.type = j + 1;
2206
2207                         if (mls_setup_user_range(fromcon, user, &usercon))
2208                                 continue;
2209
2210                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2211                         if (rc)
2212                                 goto out_unlock;
2213                         if (mynel < maxnel) {
2214                                 mysids[mynel++] = sid;
2215                         } else {
2216                                 rc = -ENOMEM;
2217                                 maxnel += SIDS_NEL;
2218                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2219                                 if (!mysids2)
2220                                         goto out_unlock;
2221                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2222                                 kfree(mysids);
2223                                 mysids = mysids2;
2224                                 mysids[mynel++] = sid;
2225                         }
2226                 }
2227         }
2228         rc = 0;
2229 out_unlock:
2230         read_unlock(&policy_rwlock);
2231         if (rc || !mynel) {
2232                 kfree(mysids);
2233                 goto out;
2234         }
2235
2236         rc = -ENOMEM;
2237         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2238         if (!mysids2) {
2239                 kfree(mysids);
2240                 goto out;
2241         }
2242         for (i = 0, j = 0; i < mynel; i++) {
2243                 struct av_decision dummy_avd;
2244                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2245                                           SECCLASS_PROCESS, /* kernel value */
2246                                           PROCESS__TRANSITION, AVC_STRICT,
2247                                           &dummy_avd);
2248                 if (!rc)
2249                         mysids2[j++] = mysids[i];
2250                 cond_resched();
2251         }
2252         rc = 0;
2253         kfree(mysids);
2254         *sids = mysids2;
2255         *nel = j;
2256 out:
2257         return rc;
2258 }
2259
2260 /**
2261  * security_genfs_sid - Obtain a SID for a file in a filesystem
2262  * @fstype: filesystem type
2263  * @path: path from root of mount
2264  * @sclass: file security class
2265  * @sid: SID for path
2266  *
2267  * Obtain a SID to use for a file in a filesystem that
2268  * cannot support xattr or use a fixed labeling behavior like
2269  * transition SIDs or task SIDs.
2270  */
2271 int security_genfs_sid(const char *fstype,
2272                        char *path,
2273                        u16 orig_sclass,
2274                        u32 *sid)
2275 {
2276         int len;
2277         u16 sclass;
2278         struct genfs *genfs;
2279         struct ocontext *c;
2280         int rc, cmp = 0;
2281
2282         while (path[0] == '/' && path[1] == '/')
2283                 path++;
2284
2285         read_lock(&policy_rwlock);
2286
2287         sclass = unmap_class(orig_sclass);
2288         *sid = SECINITSID_UNLABELED;
2289
2290         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2291                 cmp = strcmp(fstype, genfs->fstype);
2292                 if (cmp <= 0)
2293                         break;
2294         }
2295
2296         rc = -ENOENT;
2297         if (!genfs || cmp)
2298                 goto out;
2299
2300         for (c = genfs->head; c; c = c->next) {
2301                 len = strlen(c->u.name);
2302                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2303                     (strncmp(c->u.name, path, len) == 0))
2304                         break;
2305         }
2306
2307         rc = -ENOENT;
2308         if (!c)
2309                 goto out;
2310
2311         if (!c->sid[0]) {
2312                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2313                 if (rc)
2314                         goto out;
2315         }
2316
2317         *sid = c->sid[0];
2318         rc = 0;
2319 out:
2320         read_unlock(&policy_rwlock);
2321         return rc;
2322 }
2323
2324 /**
2325  * security_fs_use - Determine how to handle labeling for a filesystem.
2326  * @fstype: filesystem type
2327  * @behavior: labeling behavior
2328  * @sid: SID for filesystem (superblock)
2329  */
2330 int security_fs_use(
2331         const char *fstype,
2332         unsigned int *behavior,
2333         u32 *sid)
2334 {
2335         int rc = 0;
2336         struct ocontext *c;
2337
2338         read_lock(&policy_rwlock);
2339
2340         c = policydb.ocontexts[OCON_FSUSE];
2341         while (c) {
2342                 if (strcmp(fstype, c->u.name) == 0)
2343                         break;
2344                 c = c->next;
2345         }
2346
2347         if (c) {
2348                 *behavior = c->v.behavior;
2349                 if (!c->sid[0]) {
2350                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2351                                                    &c->sid[0]);
2352                         if (rc)
2353                                 goto out;
2354                 }
2355                 *sid = c->sid[0];
2356         } else {
2357                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2358                 if (rc) {
2359                         *behavior = SECURITY_FS_USE_NONE;
2360                         rc = 0;
2361                 } else {
2362                         *behavior = SECURITY_FS_USE_GENFS;
2363                 }
2364         }
2365
2366 out:
2367         read_unlock(&policy_rwlock);
2368         return rc;
2369 }
2370
2371 int security_get_bools(int *len, char ***names, int **values)
2372 {
2373         int i, rc;
2374
2375         read_lock(&policy_rwlock);
2376         *names = NULL;
2377         *values = NULL;
2378
2379         rc = 0;
2380         *len = policydb.p_bools.nprim;
2381         if (!*len)
2382                 goto out;
2383
2384         rc = -ENOMEM;
2385         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2386         if (!*names)
2387                 goto err;
2388
2389         rc = -ENOMEM;
2390         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2391         if (!*values)
2392                 goto err;
2393
2394         for (i = 0; i < *len; i++) {
2395                 size_t name_len;
2396
2397                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2398                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2399
2400                 rc = -ENOMEM;
2401                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2402                 if (!(*names)[i])
2403                         goto err;
2404
2405                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2406                 (*names)[i][name_len - 1] = 0;
2407         }
2408         rc = 0;
2409 out:
2410         read_unlock(&policy_rwlock);
2411         return rc;
2412 err:
2413         if (*names) {
2414                 for (i = 0; i < *len; i++)
2415                         kfree((*names)[i]);
2416         }
2417         kfree(*values);
2418         goto out;
2419 }
2420
2421
2422 int security_set_bools(int len, int *values)
2423 {
2424         int i, rc;
2425         int lenp, seqno = 0;
2426         struct cond_node *cur;
2427
2428         write_lock_irq(&policy_rwlock);
2429
2430         rc = -EFAULT;
2431         lenp = policydb.p_bools.nprim;
2432         if (len != lenp)
2433                 goto out;
2434
2435         for (i = 0; i < len; i++) {
2436                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2437                         audit_log(current->audit_context, GFP_ATOMIC,
2438                                 AUDIT_MAC_CONFIG_CHANGE,
2439                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2440                                 sym_name(&policydb, SYM_BOOLS, i),
2441                                 !!values[i],
2442                                 policydb.bool_val_to_struct[i]->state,
2443                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2444                                 audit_get_sessionid(current));
2445                 }
2446                 if (values[i])
2447                         policydb.bool_val_to_struct[i]->state = 1;
2448                 else
2449                         policydb.bool_val_to_struct[i]->state = 0;
2450         }
2451
2452         for (cur = policydb.cond_list; cur; cur = cur->next) {
2453                 rc = evaluate_cond_node(&policydb, cur);
2454                 if (rc)
2455                         goto out;
2456         }
2457
2458         seqno = ++latest_granting;
2459         rc = 0;
2460 out:
2461         write_unlock_irq(&policy_rwlock);
2462         if (!rc) {
2463                 avc_ss_reset(seqno);
2464                 selnl_notify_policyload(seqno);
2465                 selinux_status_update_policyload(seqno);
2466                 selinux_xfrm_notify_policyload();
2467         }
2468         return rc;
2469 }
2470
2471 int security_get_bool_value(int bool)
2472 {
2473         int rc;
2474         int len;
2475
2476         read_lock(&policy_rwlock);
2477
2478         rc = -EFAULT;
2479         len = policydb.p_bools.nprim;
2480         if (bool >= len)
2481                 goto out;
2482
2483         rc = policydb.bool_val_to_struct[bool]->state;
2484 out:
2485         read_unlock(&policy_rwlock);
2486         return rc;
2487 }
2488
2489 static int security_preserve_bools(struct policydb *p)
2490 {
2491         int rc, nbools = 0, *bvalues = NULL, i;
2492         char **bnames = NULL;
2493         struct cond_bool_datum *booldatum;
2494         struct cond_node *cur;
2495
2496         rc = security_get_bools(&nbools, &bnames, &bvalues);
2497         if (rc)
2498                 goto out;
2499         for (i = 0; i < nbools; i++) {
2500                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2501                 if (booldatum)
2502                         booldatum->state = bvalues[i];
2503         }
2504         for (cur = p->cond_list; cur; cur = cur->next) {
2505                 rc = evaluate_cond_node(p, cur);
2506                 if (rc)
2507                         goto out;
2508         }
2509
2510 out:
2511         if (bnames) {
2512                 for (i = 0; i < nbools; i++)
2513                         kfree(bnames[i]);
2514         }
2515         kfree(bnames);
2516         kfree(bvalues);
2517         return rc;
2518 }
2519
2520 /*
2521  * security_sid_mls_copy() - computes a new sid based on the given
2522  * sid and the mls portion of mls_sid.
2523  */
2524 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2525 {
2526         struct context *context1;
2527         struct context *context2;
2528         struct context newcon;
2529         char *s;
2530         u32 len;
2531         int rc;
2532
2533         rc = 0;
2534         if (!ss_initialized || !policydb.mls_enabled) {
2535                 *new_sid = sid;
2536                 goto out;
2537         }
2538
2539         context_init(&newcon);
2540
2541         read_lock(&policy_rwlock);
2542
2543         rc = -EINVAL;
2544         context1 = sidtab_search(&sidtab, sid);
2545         if (!context1) {
2546                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2547                         __func__, sid);
2548                 goto out_unlock;
2549         }
2550
2551         rc = -EINVAL;
2552         context2 = sidtab_search(&sidtab, mls_sid);
2553         if (!context2) {
2554                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2555                         __func__, mls_sid);
2556                 goto out_unlock;
2557         }
2558
2559         newcon.user = context1->user;
2560         newcon.role = context1->role;
2561         newcon.type = context1->type;
2562         rc = mls_context_cpy(&newcon, context2);
2563         if (rc)
2564                 goto out_unlock;
2565
2566         /* Check the validity of the new context. */
2567         if (!policydb_context_isvalid(&policydb, &newcon)) {
2568                 rc = convert_context_handle_invalid_context(&newcon);
2569                 if (rc) {
2570                         if (!context_struct_to_string(&newcon, &s, &len)) {
2571                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2572                                           "security_sid_mls_copy: invalid context %s", s);
2573                                 kfree(s);
2574                         }
2575                         goto out_unlock;
2576                 }
2577         }
2578
2579         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2580 out_unlock:
2581         read_unlock(&policy_rwlock);
2582         context_destroy(&newcon);
2583 out:
2584         return rc;
2585 }
2586
2587 /**
2588  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2589  * @nlbl_sid: NetLabel SID
2590  * @nlbl_type: NetLabel labeling protocol type
2591  * @xfrm_sid: XFRM SID
2592  *
2593  * Description:
2594  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2595  * resolved into a single SID it is returned via @peer_sid and the function
2596  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2597  * returns a negative value.  A table summarizing the behavior is below:
2598  *
2599  *                                 | function return |      @sid
2600  *   ------------------------------+-----------------+-----------------
2601  *   no peer labels                |        0        |    SECSID_NULL
2602  *   single peer label             |        0        |    <peer_label>
2603  *   multiple, consistent labels   |        0        |    <peer_label>
2604  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2605  *
2606  */
2607 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2608                                  u32 xfrm_sid,
2609                                  u32 *peer_sid)
2610 {
2611         int rc;
2612         struct context *nlbl_ctx;
2613         struct context *xfrm_ctx;
2614
2615         *peer_sid = SECSID_NULL;
2616
2617         /* handle the common (which also happens to be the set of easy) cases
2618          * right away, these two if statements catch everything involving a
2619          * single or absent peer SID/label */
2620         if (xfrm_sid == SECSID_NULL) {
2621                 *peer_sid = nlbl_sid;
2622                 return 0;
2623         }
2624         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2625          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2626          * is present */
2627         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2628                 *peer_sid = xfrm_sid;
2629                 return 0;
2630         }
2631
2632         /* we don't need to check ss_initialized here since the only way both
2633          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2634          * security server was initialized and ss_initialized was true */
2635         if (!policydb.mls_enabled)
2636                 return 0;
2637
2638         read_lock(&policy_rwlock);
2639
2640         rc = -EINVAL;
2641         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2642         if (!nlbl_ctx) {
2643                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2644                        __func__, nlbl_sid);
2645                 goto out;
2646         }
2647         rc = -EINVAL;
2648         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2649         if (!xfrm_ctx) {
2650                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2651                        __func__, xfrm_sid);
2652                 goto out;
2653         }
2654         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2655         if (rc)
2656                 goto out;
2657
2658         /* at present NetLabel SIDs/labels really only carry MLS
2659          * information so if the MLS portion of the NetLabel SID
2660          * matches the MLS portion of the labeled XFRM SID/label
2661          * then pass along the XFRM SID as it is the most
2662          * expressive */
2663         *peer_sid = xfrm_sid;
2664 out:
2665         read_unlock(&policy_rwlock);
2666         return rc;
2667 }
2668
2669 static int get_classes_callback(void *k, void *d, void *args)
2670 {
2671         struct class_datum *datum = d;
2672         char *name = k, **classes = args;
2673         int value = datum->value - 1;
2674
2675         classes[value] = kstrdup(name, GFP_ATOMIC);
2676         if (!classes[value])
2677                 return -ENOMEM;
2678
2679         return 0;
2680 }
2681
2682 int security_get_classes(char ***classes, int *nclasses)
2683 {
2684         int rc;
2685
2686         read_lock(&policy_rwlock);
2687
2688         rc = -ENOMEM;
2689         *nclasses = policydb.p_classes.nprim;
2690         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2691         if (!*classes)
2692                 goto out;
2693
2694         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2695                         *classes);
2696         if (rc) {
2697                 int i;
2698                 for (i = 0; i < *nclasses; i++)
2699                         kfree((*classes)[i]);
2700                 kfree(*classes);
2701         }
2702
2703 out:
2704         read_unlock(&policy_rwlock);
2705         return rc;
2706 }
2707
2708 static int get_permissions_callback(void *k, void *d, void *args)
2709 {
2710         struct perm_datum *datum = d;
2711         char *name = k, **perms = args;
2712         int value = datum->value - 1;
2713
2714         perms[value] = kstrdup(name, GFP_ATOMIC);
2715         if (!perms[value])
2716                 return -ENOMEM;
2717
2718         return 0;
2719 }
2720
2721 int security_get_permissions(char *class, char ***perms, int *nperms)
2722 {
2723         int rc, i;
2724         struct class_datum *match;
2725
2726         read_lock(&policy_rwlock);
2727
2728         rc = -EINVAL;
2729         match = hashtab_search(policydb.p_classes.table, class);
2730         if (!match) {
2731                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2732                         __func__, class);
2733                 goto out;
2734         }
2735
2736         rc = -ENOMEM;
2737         *nperms = match->permissions.nprim;
2738         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2739         if (!*perms)
2740                 goto out;
2741
2742         if (match->comdatum) {
2743                 rc = hashtab_map(match->comdatum->permissions.table,
2744                                 get_permissions_callback, *perms);
2745                 if (rc)
2746                         goto err;
2747         }
2748
2749         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2750                         *perms);
2751         if (rc)
2752                 goto err;
2753
2754 out:
2755         read_unlock(&policy_rwlock);
2756         return rc;
2757
2758 err:
2759         read_unlock(&policy_rwlock);
2760         for (i = 0; i < *nperms; i++)
2761                 kfree((*perms)[i]);
2762         kfree(*perms);
2763         return rc;
2764 }
2765
2766 int security_get_reject_unknown(void)
2767 {
2768         return policydb.reject_unknown;
2769 }
2770
2771 int security_get_allow_unknown(void)
2772 {
2773         return policydb.allow_unknown;
2774 }
2775
2776 /**
2777  * security_policycap_supported - Check for a specific policy capability
2778  * @req_cap: capability
2779  *
2780  * Description:
2781  * This function queries the currently loaded policy to see if it supports the
2782  * capability specified by @req_cap.  Returns true (1) if the capability is
2783  * supported, false (0) if it isn't supported.
2784  *
2785  */
2786 int security_policycap_supported(unsigned int req_cap)
2787 {
2788         int rc;
2789
2790         read_lock(&policy_rwlock);
2791         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2792         read_unlock(&policy_rwlock);
2793
2794         return rc;
2795 }
2796
2797 struct selinux_audit_rule {
2798         u32 au_seqno;
2799         struct context au_ctxt;
2800 };
2801
2802 void selinux_audit_rule_free(void *vrule)
2803 {
2804         struct selinux_audit_rule *rule = vrule;
2805
2806         if (rule) {
2807                 context_destroy(&rule->au_ctxt);
2808                 kfree(rule);
2809         }
2810 }
2811
2812 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2813 {
2814         struct selinux_audit_rule *tmprule;
2815         struct role_datum *roledatum;
2816         struct type_datum *typedatum;
2817         struct user_datum *userdatum;
2818         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2819         int rc = 0;
2820
2821         *rule = NULL;
2822
2823         if (!ss_initialized)
2824                 return -EOPNOTSUPP;
2825
2826         switch (field) {
2827         case AUDIT_SUBJ_USER:
2828         case AUDIT_SUBJ_ROLE:
2829         case AUDIT_SUBJ_TYPE:
2830         case AUDIT_OBJ_USER:
2831         case AUDIT_OBJ_ROLE:
2832         case AUDIT_OBJ_TYPE:
2833                 /* only 'equals' and 'not equals' fit user, role, and type */
2834                 if (op != Audit_equal && op != Audit_not_equal)
2835                         return -EINVAL;
2836                 break;
2837         case AUDIT_SUBJ_SEN:
2838         case AUDIT_SUBJ_CLR:
2839         case AUDIT_OBJ_LEV_LOW:
2840         case AUDIT_OBJ_LEV_HIGH:
2841                 /* we do not allow a range, indicated by the presence of '-' */
2842                 if (strchr(rulestr, '-'))
2843                         return -EINVAL;
2844                 break;
2845         default:
2846                 /* only the above fields are valid */
2847                 return -EINVAL;
2848         }
2849
2850         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2851         if (!tmprule)
2852                 return -ENOMEM;
2853
2854         context_init(&tmprule->au_ctxt);
2855
2856         read_lock(&policy_rwlock);
2857
2858         tmprule->au_seqno = latest_granting;
2859
2860         switch (field) {
2861         case AUDIT_SUBJ_USER:
2862         case AUDIT_OBJ_USER:
2863                 rc = -EINVAL;
2864                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2865                 if (!userdatum)
2866                         goto out;
2867                 tmprule->au_ctxt.user = userdatum->value;
2868                 break;
2869         case AUDIT_SUBJ_ROLE:
2870         case AUDIT_OBJ_ROLE:
2871                 rc = -EINVAL;
2872                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2873                 if (!roledatum)
2874                         goto out;
2875                 tmprule->au_ctxt.role = roledatum->value;
2876                 break;
2877         case AUDIT_SUBJ_TYPE:
2878         case AUDIT_OBJ_TYPE:
2879                 rc = -EINVAL;
2880                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2881                 if (!typedatum)
2882                         goto out;
2883                 tmprule->au_ctxt.type = typedatum->value;
2884                 break;
2885         case AUDIT_SUBJ_SEN:
2886         case AUDIT_SUBJ_CLR:
2887         case AUDIT_OBJ_LEV_LOW:
2888         case AUDIT_OBJ_LEV_HIGH:
2889                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2890                 if (rc)
2891                         goto out;
2892                 break;
2893         }
2894         rc = 0;
2895 out:
2896         read_unlock(&policy_rwlock);
2897
2898         if (rc) {
2899                 selinux_audit_rule_free(tmprule);
2900                 tmprule = NULL;
2901         }
2902
2903         *rule = tmprule;
2904
2905         return rc;
2906 }
2907
2908 /* Check to see if the rule contains any selinux fields */
2909 int selinux_audit_rule_known(struct audit_krule *rule)
2910 {
2911         int i;
2912
2913         for (i = 0; i < rule->field_count; i++) {
2914                 struct audit_field *f = &rule->fields[i];
2915                 switch (f->type) {
2916                 case AUDIT_SUBJ_USER:
2917                 case AUDIT_SUBJ_ROLE:
2918                 case AUDIT_SUBJ_TYPE:
2919                 case AUDIT_SUBJ_SEN:
2920                 case AUDIT_SUBJ_CLR:
2921                 case AUDIT_OBJ_USER:
2922                 case AUDIT_OBJ_ROLE:
2923                 case AUDIT_OBJ_TYPE:
2924                 case AUDIT_OBJ_LEV_LOW:
2925                 case AUDIT_OBJ_LEV_HIGH:
2926                         return 1;
2927                 }
2928         }
2929
2930         return 0;
2931 }
2932
2933 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2934                              struct audit_context *actx)
2935 {
2936         struct context *ctxt;
2937         struct mls_level *level;
2938         struct selinux_audit_rule *rule = vrule;
2939         int match = 0;
2940
2941         if (!rule) {
2942                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2943                           "selinux_audit_rule_match: missing rule\n");
2944                 return -ENOENT;
2945         }
2946
2947         read_lock(&policy_rwlock);
2948
2949         if (rule->au_seqno < latest_granting) {
2950                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2951                           "selinux_audit_rule_match: stale rule\n");
2952                 match = -ESTALE;
2953                 goto out;
2954         }
2955
2956         ctxt = sidtab_search(&sidtab, sid);
2957         if (!ctxt) {
2958                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2959                           "selinux_audit_rule_match: unrecognized SID %d\n",
2960                           sid);
2961                 match = -ENOENT;
2962                 goto out;
2963         }
2964
2965         /* a field/op pair that is not caught here will simply fall through
2966            without a match */
2967         switch (field) {
2968         case AUDIT_SUBJ_USER:
2969         case AUDIT_OBJ_USER:
2970                 switch (op) {
2971                 case Audit_equal:
2972                         match = (ctxt->user == rule->au_ctxt.user);
2973                         break;
2974                 case Audit_not_equal:
2975                         match = (ctxt->user != rule->au_ctxt.user);
2976                         break;
2977                 }
2978                 break;
2979         case AUDIT_SUBJ_ROLE:
2980         case AUDIT_OBJ_ROLE:
2981                 switch (op) {
2982                 case Audit_equal:
2983                         match = (ctxt->role == rule->au_ctxt.role);
2984                         break;
2985                 case Audit_not_equal:
2986                         match = (ctxt->role != rule->au_ctxt.role);
2987                         break;
2988                 }
2989                 break;
2990         case AUDIT_SUBJ_TYPE:
2991         case AUDIT_OBJ_TYPE:
2992                 switch (op) {
2993                 case Audit_equal:
2994                         match = (ctxt->type == rule->au_ctxt.type);
2995                         break;
2996                 case Audit_not_equal:
2997                         match = (ctxt->type != rule->au_ctxt.type);
2998                         break;
2999                 }
3000                 break;
3001         case AUDIT_SUBJ_SEN:
3002         case AUDIT_SUBJ_CLR:
3003         case AUDIT_OBJ_LEV_LOW:
3004         case AUDIT_OBJ_LEV_HIGH:
3005                 level = ((field == AUDIT_SUBJ_SEN ||
3006                           field == AUDIT_OBJ_LEV_LOW) ?
3007                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3008                 switch (op) {
3009                 case Audit_equal:
3010                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3011                                              level);
3012                         break;
3013                 case Audit_not_equal:
3014                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3015                                               level);
3016                         break;
3017                 case Audit_lt:
3018                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3019                                                level) &&
3020                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3021                                                level));
3022                         break;
3023                 case Audit_le:
3024                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3025                                               level);
3026                         break;
3027                 case Audit_gt:
3028                         match = (mls_level_dom(level,
3029                                               &rule->au_ctxt.range.level[0]) &&
3030                                  !mls_level_eq(level,
3031                                                &rule->au_ctxt.range.level[0]));
3032                         break;
3033                 case Audit_ge:
3034                         match = mls_level_dom(level,
3035                                               &rule->au_ctxt.range.level[0]);
3036                         break;
3037                 }
3038         }
3039
3040 out:
3041         read_unlock(&policy_rwlock);
3042         return match;
3043 }
3044
3045 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3046
3047 static int aurule_avc_callback(u32 event)
3048 {
3049         int err = 0;
3050
3051         if (event == AVC_CALLBACK_RESET && aurule_callback)
3052                 err = aurule_callback();
3053         return err;
3054 }
3055
3056 static int __init aurule_init(void)
3057 {
3058         int err;
3059
3060         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3061         if (err)
3062                 panic("avc_add_callback() failed, error %d\n", err);
3063
3064         return err;
3065 }
3066 __initcall(aurule_init);
3067
3068 #ifdef CONFIG_NETLABEL
3069 /**
3070  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3071  * @secattr: the NetLabel packet security attributes
3072  * @sid: the SELinux SID
3073  *
3074  * Description:
3075  * Attempt to cache the context in @ctx, which was derived from the packet in
3076  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3077  * already been initialized.
3078  *
3079  */
3080 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3081                                       u32 sid)
3082 {
3083         u32 *sid_cache;
3084
3085         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3086         if (sid_cache == NULL)
3087                 return;
3088         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3089         if (secattr->cache == NULL) {
3090                 kfree(sid_cache);
3091                 return;
3092         }
3093
3094         *sid_cache = sid;
3095         secattr->cache->free = kfree;
3096         secattr->cache->data = sid_cache;
3097         secattr->flags |= NETLBL_SECATTR_CACHE;
3098 }
3099
3100 /**
3101  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3102  * @secattr: the NetLabel packet security attributes
3103  * @sid: the SELinux SID
3104  *
3105  * Description:
3106  * Convert the given NetLabel security attributes in @secattr into a
3107  * SELinux SID.  If the @secattr field does not contain a full SELinux
3108  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3109  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3110  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3111  * conversion for future lookups.  Returns zero on success, negative values on
3112  * failure.
3113  *
3114  */
3115 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3116                                    u32 *sid)
3117 {
3118         int rc;
3119         struct context *ctx;
3120         struct context ctx_new;
3121
3122         if (!ss_initialized) {
3123                 *sid = SECSID_NULL;
3124                 return 0;
3125         }
3126
3127         read_lock(&policy_rwlock);
3128
3129         if (secattr->flags & NETLBL_SECATTR_CACHE)
3130                 *sid = *(u32 *)secattr->cache->data;
3131         else if (secattr->flags & NETLBL_SECATTR_SECID)
3132                 *sid = secattr->attr.secid;
3133         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3134                 rc = -EIDRM;
3135                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3136                 if (ctx == NULL)
3137                         goto out;
3138
3139                 context_init(&ctx_new);
3140                 ctx_new.user = ctx->user;
3141                 ctx_new.role = ctx->role;
3142                 ctx_new.type = ctx->type;
3143                 mls_import_netlbl_lvl(&ctx_new, secattr);
3144                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3145                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3146                                                    secattr->attr.mls.cat);
3147                         if (rc)
3148                                 goto out;
3149                         memcpy(&ctx_new.range.level[1].cat,
3150                                &ctx_new.range.level[0].cat,
3151                                sizeof(ctx_new.range.level[0].cat));
3152                 }
3153                 rc = -EIDRM;
3154                 if (!mls_context_isvalid(&policydb, &ctx_new))
3155                         goto out_free;
3156
3157                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3158                 if (rc)
3159                         goto out_free;
3160
3161                 security_netlbl_cache_add(secattr, *sid);
3162
3163                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3164         } else
3165                 *sid = SECSID_NULL;
3166
3167         read_unlock(&policy_rwlock);
3168         return 0;
3169 out_free:
3170         ebitmap_destroy(&ctx_new.range.level[0].cat);
3171 out:
3172         read_unlock(&policy_rwlock);
3173         return rc;
3174 }
3175
3176 /**
3177  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3178  * @sid: the SELinux SID
3179  * @secattr: the NetLabel packet security attributes
3180  *
3181  * Description:
3182  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3183  * Returns zero on success, negative values on failure.
3184  *
3185  */
3186 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3187 {
3188         int rc;
3189         struct context *ctx;
3190
3191         if (!ss_initialized)
3192                 return 0;
3193
3194         read_lock(&policy_rwlock);
3195
3196         rc = -ENOENT;
3197         ctx = sidtab_search(&sidtab, sid);
3198         if (ctx == NULL)
3199                 goto out;
3200
3201         rc = -ENOMEM;
3202         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3203                                   GFP_ATOMIC);
3204         if (secattr->domain == NULL)
3205                 goto out;
3206
3207         secattr->attr.secid = sid;
3208         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3209         mls_export_netlbl_lvl(ctx, secattr);
3210         rc = mls_export_netlbl_cat(ctx, secattr);
3211 out:
3212         read_unlock(&policy_rwlock);
3213         return rc;
3214 }
3215 #endif /* CONFIG_NETLABEL */
3216
3217 /**
3218  * security_read_policy - read the policy.
3219  * @data: binary policy data
3220  * @len: length of data in bytes
3221  *
3222  */
3223 int security_read_policy(void **data, size_t *len)
3224 {
3225         int rc;
3226         struct policy_file fp;
3227
3228         if (!ss_initialized)
3229                 return -EINVAL;
3230
3231         *len = security_policydb_len();
3232
3233         *data = vmalloc_user(*len);
3234         if (!*data)
3235                 return -ENOMEM;
3236
3237         fp.data = *data;
3238         fp.len = *len;
3239
3240         read_lock(&policy_rwlock);
3241         rc = policydb_write(&policydb, &fp);
3242         read_unlock(&policy_rwlock);
3243
3244         if (rc)
3245                 return rc;
3246
3247         *len = (unsigned long)fp.data - (unsigned long)*data;
3248         return 0;
3249
3250 }