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 int selinux_policycap_alwaysnetwork;
  76
  77 static DEFINE_RWLOCK(policy_rwlock);
  78
  79 static struct sidtab sidtab;
  80 struct policydb policydb;
  81 int ss_initialized;
  82
  83 /*
  84  * The largest sequence number that has been used when
  85  * providing an access decision to the access vector cache.
  86  * The sequence number only changes when a policy change
  87  * occurs.
  88  */
  89 static u32 latest_granting;
  90
  91 /* Forward declaration. */
  92 static int context_struct_to_string(struct context *context, char **scontext,
  93                                     u32 *scontext_len);
  94
  95 static void context_struct_compute_av(struct context *scontext,
  96                                         struct context *tcontext,
  97                                         u16 tclass,
  98                                         struct av_decision *avd,
  99                                         struct extended_perms *xperms);
 100
 101 struct selinux_mapping {
 102         u16 value; /* policy value */
 103         unsigned num_perms;
 104         u32 perms[sizeof(u32) * 8];
 105 };
 106
 107 static struct selinux_mapping *current_mapping;
 108 static u16 current_mapping_size;
 109
 110 static int selinux_set_mapping(struct policydb *pol,
 111                                struct security_class_mapping *map,
 112                                struct selinux_mapping **out_map_p,
 113                                u16 *out_map_size)
 114 {
 115         struct selinux_mapping *out_map = NULL;
 116         size_t size = sizeof(struct selinux_mapping);
 117         u16 i, j;
 118         unsigned k;
 119         bool print_unknown_handle = false;
 120
 121         /* Find number of classes in the input mapping */
 122         if (!map)
 123                 return -EINVAL;
 124         i = 0;
 125         while (map[i].name)
 126                 i++;
 127
 128         /* Allocate space for the class records, plus one for class zero */
 129         out_map = kcalloc(++i, size, GFP_ATOMIC);
 130         if (!out_map)
 131                 return -ENOMEM;
 132
 133         /* Store the raw class and permission values */
 134         j = 0;
 135         while (map[j].name) {
 136                 struct security_class_mapping *p_in = map + (j++);
 137                 struct selinux_mapping *p_out = out_map + j;
 138
 139                 /* An empty class string skips ahead */
 140                 if (!strcmp(p_in->name, "")) {
 141                         p_out->num_perms = 0;
 142                         continue;
 143                 }
 144
 145                 p_out->value = string_to_security_class(pol, p_in->name);
 146                 if (!p_out->value) {
 147                         printk(KERN_INFO
 148                                "SELinux:  Class %s not defined in policy.\n",
 149                                p_in->name);
 150                         if (pol->reject_unknown)
 151                                 goto err;
 152                         p_out->num_perms = 0;
 153                         print_unknown_handle = true;
 154                         continue;
 155                 }
 156
 157                 k = 0;
 158                 while (p_in->perms[k]) {
 159                         /* An empty permission string skips ahead */
 160                         if (!*p_in->perms[k]) {
 161                                 k++;
 162                                 continue;
 163                         }
 164                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 165                                                             p_in->perms[k]);
 166                         if (!p_out->perms[k]) {
 167                                 printk(KERN_INFO
 168                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 169                                        p_in->perms[k], p_in->name);
 170                                 if (pol->reject_unknown)
 171                                         goto err;
 172                                 print_unknown_handle = true;
 173                         }
 174
 175                         k++;
 176                 }
 177                 p_out->num_perms = k;
 178         }
 179
 180         if (print_unknown_handle)
 181                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 182                        pol->allow_unknown ? "allowed" : "denied");
 183
 184         *out_map_p = out_map;
 185         *out_map_size = i;
 186         return 0;
 187 err:
 188         kfree(out_map);
 189         return -EINVAL;
 190 }
 191
 192 /*
 193  * Get real, policy values from mapped values
 194  */
 195
 196 static u16 unmap_class(u16 tclass)
 197 {
 198         if (tclass < current_mapping_size)
 199                 return current_mapping[tclass].value;
 200
 201         return tclass;
 202 }
 203
 204 /*
 205  * Get kernel value for class from its policy value
 206  */
 207 static u16 map_class(u16 pol_value)
 208 {
 209         u16 i;
 210
 211         for (i = 1; i < current_mapping_size; i++) {
 212                 if (current_mapping[i].value == pol_value)
 213                         return i;
 214         }
 215
 216         return SECCLASS_NULL;
 217 }
 218
 219 static void map_decision(u16 tclass, struct av_decision *avd,
 220                          int allow_unknown)
 221 {
 222         if (tclass < current_mapping_size) {
 223                 unsigned i, n = current_mapping[tclass].num_perms;
 224                 u32 result;
 225
 226                 for (i = 0, result = 0; i < n; i++) {
 227                         if (avd->allowed & current_mapping[tclass].perms[i])
 228                                 result |= 1<<i;
 229                         if (allow_unknown && !current_mapping[tclass].perms[i])
 230                                 result |= 1<<i;
 231                 }
 232                 avd->allowed = result;
 233
 234                 for (i = 0, result = 0; i < n; i++)
 235                         if (avd->auditallow & current_mapping[tclass].perms[i])
 236                                 result |= 1<<i;
 237                 avd->auditallow = result;
 238
 239                 for (i = 0, result = 0; i < n; i++) {
 240                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 241                                 result |= 1<<i;
 242                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 243                                 result |= 1<<i;
 244                 }
 245                 /*
 246                  * In case the kernel has a bug and requests a permission
 247                  * between num_perms and the maximum permission number, we
 248                  * should audit that denial
 249                  */
 250                 for (; i < (sizeof(u32)*8); i++)
 251                         result |= 1<<i;
 252                 avd->auditdeny = result;
 253         }
 254 }
 255
 256 int security_mls_enabled(void)
 257 {
 258         return policydb.mls_enabled;
 259 }
 260
 261 /*
 262  * Return the boolean value of a constraint expression
 263  * when it is applied to the specified source and target
 264  * security contexts.
 265  *
 266  * xcontext is a special beast...  It is used by the validatetrans rules
 267  * only.  For these rules, scontext is the context before the transition,
 268  * tcontext is the context after the transition, and xcontext is the context
 269  * of the process performing the transition.  All other callers of
 270  * constraint_expr_eval should pass in NULL for xcontext.
 271  */
 272 static int constraint_expr_eval(struct context *scontext,
 273                                 struct context *tcontext,
 274                                 struct context *xcontext,
 275                                 struct constraint_expr *cexpr)
 276 {
 277         u32 val1, val2;
 278         struct context *c;
 279         struct role_datum *r1, *r2;
 280         struct mls_level *l1, *l2;
 281         struct constraint_expr *e;
 282         int s[CEXPR_MAXDEPTH];
 283         int sp = -1;
 284
 285         for (e = cexpr; e; e = e->next) {
 286                 switch (e->expr_type) {
 287                 case CEXPR_NOT:
 288                         BUG_ON(sp < 0);
 289                         s[sp] = !s[sp];
 290                         break;
 291                 case CEXPR_AND:
 292                         BUG_ON(sp < 1);
 293                         sp--;
 294                         s[sp] &= s[sp + 1];
 295                         break;
 296                 case CEXPR_OR:
 297                         BUG_ON(sp < 1);
 298                         sp--;
 299                         s[sp] |= s[sp + 1];
 300                         break;
 301                 case CEXPR_ATTR:
 302                         if (sp == (CEXPR_MAXDEPTH - 1))
 303                                 return 0;
 304                         switch (e->attr) {
 305                         case CEXPR_USER:
 306                                 val1 = scontext->user;
 307                                 val2 = tcontext->user;
 308                                 break;
 309                         case CEXPR_TYPE:
 310                                 val1 = scontext->type;
 311                                 val2 = tcontext->type;
 312                                 break;
 313                         case CEXPR_ROLE:
 314                                 val1 = scontext->role;
 315                                 val2 = tcontext->role;
 316                                 r1 = policydb.role_val_to_struct[val1 - 1];
 317                                 r2 = policydb.role_val_to_struct[val2 - 1];
 318                                 switch (e->op) {
 319                                 case CEXPR_DOM:
 320                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 321                                                                   val2 - 1);
 322                                         continue;
 323                                 case CEXPR_DOMBY:
 324                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 325                                                                   val1 - 1);
 326                                         continue;
 327                                 case CEXPR_INCOMP:
 328                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 329                                                                     val2 - 1) &&
 330                                                    !ebitmap_get_bit(&r2->dominates,
 331                                                                     val1 - 1));
 332                                         continue;
 333                                 default:
 334                                         break;
 335                                 }
 336                                 break;
 337                         case CEXPR_L1L2:
 338                                 l1 = &(scontext->range.level[0]);
 339                                 l2 = &(tcontext->range.level[0]);
 340                                 goto mls_ops;
 341                         case CEXPR_L1H2:
 342                                 l1 = &(scontext->range.level[0]);
 343                                 l2 = &(tcontext->range.level[1]);
 344                                 goto mls_ops;
 345                         case CEXPR_H1L2:
 346                                 l1 = &(scontext->range.level[1]);
 347                                 l2 = &(tcontext->range.level[0]);
 348                                 goto mls_ops;
 349                         case CEXPR_H1H2:
 350                                 l1 = &(scontext->range.level[1]);
 351                                 l2 = &(tcontext->range.level[1]);
 352                                 goto mls_ops;
 353                         case CEXPR_L1H1:
 354                                 l1 = &(scontext->range.level[0]);
 355                                 l2 = &(scontext->range.level[1]);
 356                                 goto mls_ops;
 357                         case CEXPR_L2H2:
 358                                 l1 = &(tcontext->range.level[0]);
 359                                 l2 = &(tcontext->range.level[1]);
 360                                 goto mls_ops;
 361 mls_ops:
 362                         switch (e->op) {
 363                         case CEXPR_EQ:
 364                                 s[++sp] = mls_level_eq(l1, l2);
 365                                 continue;
 366                         case CEXPR_NEQ:
 367                                 s[++sp] = !mls_level_eq(l1, l2);
 368                                 continue;
 369                         case CEXPR_DOM:
 370                                 s[++sp] = mls_level_dom(l1, l2);
 371                                 continue;
 372                         case CEXPR_DOMBY:
 373                                 s[++sp] = mls_level_dom(l2, l1);
 374                                 continue;
 375                         case CEXPR_INCOMP:
 376                                 s[++sp] = mls_level_incomp(l2, l1);
 377                                 continue;
 378                         default:
 379                                 BUG();
 380                                 return 0;
 381                         }
 382                         break;
 383                         default:
 384                                 BUG();
 385                                 return 0;
 386                         }
 387
 388                         switch (e->op) {
 389                         case CEXPR_EQ:
 390                                 s[++sp] = (val1 == val2);
 391                                 break;
 392                         case CEXPR_NEQ:
 393                                 s[++sp] = (val1 != val2);
 394                                 break;
 395                         default:
 396                                 BUG();
 397                                 return 0;
 398                         }
 399                         break;
 400                 case CEXPR_NAMES:
 401                         if (sp == (CEXPR_MAXDEPTH-1))
 402                                 return 0;
 403                         c = scontext;
 404                         if (e->attr & CEXPR_TARGET)
 405                                 c = tcontext;
 406                         else if (e->attr & CEXPR_XTARGET) {
 407                                 c = xcontext;
 408                                 if (!c) {
 409                                         BUG();
 410                                         return 0;
 411                                 }
 412                         }
 413                         if (e->attr & CEXPR_USER)
 414                                 val1 = c->user;
 415                         else if (e->attr & CEXPR_ROLE)
 416                                 val1 = c->role;
 417                         else if (e->attr & CEXPR_TYPE)
 418                                 val1 = c->type;
 419                         else {
 420                                 BUG();
 421                                 return 0;
 422                         }
 423
 424                         switch (e->op) {
 425                         case CEXPR_EQ:
 426                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 427                                 break;
 428                         case CEXPR_NEQ:
 429                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 430                                 break;
 431                         default:
 432                                 BUG();
 433                                 return 0;
 434                         }
 435                         break;
 436                 default:
 437                         BUG();
 438                         return 0;
 439                 }
 440         }
 441
 442         BUG_ON(sp != 0);
 443         return s[0];
 444 }
 445
 446 /*
 447  * security_dump_masked_av - dumps masked permissions during
 448  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 449  */
 450 static int dump_masked_av_helper(void *k, void *d, void *args)
 451 {
 452         struct perm_datum *pdatum = d;
 453         char **permission_names = args;
 454
 455         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 456
 457         permission_names[pdatum->value - 1] = (char *)k;
 458
 459         return 0;
 460 }
 461
 462 static void security_dump_masked_av(struct context *scontext,
 463                                     struct context *tcontext,
 464                                     u16 tclass,
 465                                     u32 permissions,
 466                                     const char *reason)
 467 {
 468         struct common_datum *common_dat;
 469         struct class_datum *tclass_dat;
 470         struct audit_buffer *ab;
 471         char *tclass_name;
 472         char *scontext_name = NULL;
 473         char *tcontext_name = NULL;
 474         char *permission_names[32];
 475         int index;
 476         u32 length;
 477         bool need_comma = false;
 478
 479         if (!permissions)
 480                 return;
 481
 482         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 483         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 484         common_dat = tclass_dat->comdatum;
 485
 486         /* init permission_names */
 487         if (common_dat &&
 488             hashtab_map(common_dat->permissions.table,
 489                         dump_masked_av_helper, permission_names) < 0)
 490                 goto out;
 491
 492         if (hashtab_map(tclass_dat->permissions.table,
 493                         dump_masked_av_helper, permission_names) < 0)
 494                 goto out;
 495
 496         /* get scontext/tcontext in text form */
 497         if (context_struct_to_string(scontext,
 498                                      &scontext_name, &length) < 0)
 499                 goto out;
 500
 501         if (context_struct_to_string(tcontext,
 502                                      &tcontext_name, &length) < 0)
 503                 goto out;
 504
 505         /* audit a message */
 506         ab = audit_log_start(current->audit_context,
 507                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 508         if (!ab)
 509                 goto out;
 510
 511         audit_log_format(ab, "op=security_compute_av reason=%s "
 512                          "scontext=%s tcontext=%s tclass=%s perms=",
 513                          reason, scontext_name, tcontext_name, tclass_name);
 514
 515         for (index = 0; index < 32; index++) {
 516                 u32 mask = (1 << index);
 517
 518                 if ((mask & permissions) == 0)
 519                         continue;
 520
 521                 audit_log_format(ab, "%s%s",
 522                                  need_comma ? "," : "",
 523                                  permission_names[index]
 524                                  ? permission_names[index] : "????");
 525                 need_comma = true;
 526         }
 527         audit_log_end(ab);
 528 out:
 529         /* release scontext/tcontext */
 530         kfree(tcontext_name);
 531         kfree(scontext_name);
 532
 533         return;
 534 }
 535
 536 /*
 537  * security_boundary_permission - drops violated permissions
 538  * on boundary constraint.
 539  */
 540 static void type_attribute_bounds_av(struct context *scontext,
 541                                      struct context *tcontext,
 542                                      u16 tclass,
 543                                      struct av_decision *avd)
 544 {
 545         struct context lo_scontext;
 546         struct context lo_tcontext, *tcontextp = tcontext;
 547         struct av_decision lo_avd;
 548         struct type_datum *source;
 549         struct type_datum *target;
 550         u32 masked = 0;
 551
 552         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 553                                     scontext->type - 1);
 554         BUG_ON(!source);
 555
 556         if (!source->bounds)
 557                 return;
 558
 559         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 560                                     tcontext->type - 1);
 561         BUG_ON(!target);
 562
 563         memset(&lo_avd, 0, sizeof(lo_avd));
 564
 565         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 566         lo_scontext.type = source->bounds;
 567
 568         if (target->bounds) {
 569                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 570                 lo_tcontext.type = target->bounds;
 571                 tcontextp = &lo_tcontext;
 572         }
 573
 574         context_struct_compute_av(&lo_scontext,
 575                                   tcontextp,
 576                                   tclass,
 577                                   &lo_avd,
 578                                   NULL);
 579
 580         masked = ~lo_avd.allowed & avd->allowed;
 581
 582         if (likely(!masked))
 583                 return;         /* no masked permission */
 584
 585         /* mask violated permissions */
 586         avd->allowed &= ~masked;
 587
 588         /* audit masked permissions */
 589         security_dump_masked_av(scontext, tcontext,
 590                                 tclass, masked, "bounds");
 591 }
 592
 593 /*
 594  * flag which drivers have permissions
 595  * only looking for ioctl based extended permssions
 596  */
 597 void services_compute_xperms_drivers(
 598                 struct extended_perms *xperms,
 599                 struct avtab_node *node)
 600 {
 601         unsigned int i;
 602
 603         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 604                 /* if one or more driver has all permissions allowed */
 605                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 606                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 607         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 608                 /* if allowing permissions within a driver */
 609                 security_xperm_set(xperms->drivers.p,
 610                                         node->datum.u.xperms->driver);
 611         }
 612
 613         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 614         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 615                 xperms->len = 1;
 616 }
 617
 618 /*
 619  * Compute access vectors and extended permissions based on a context
 620  * structure pair for the permissions in a particular class.
 621  */
 622 static void context_struct_compute_av(struct context *scontext,
 623                                         struct context *tcontext,
 624                                         u16 tclass,
 625                                         struct av_decision *avd,
 626                                         struct extended_perms *xperms)
 627 {
 628         struct constraint_node *constraint;
 629         struct role_allow *ra;
 630         struct avtab_key avkey;
 631         struct avtab_node *node;
 632         struct class_datum *tclass_datum;
 633         struct ebitmap *sattr, *tattr;
 634         struct ebitmap_node *snode, *tnode;
 635         unsigned int i, j;
 636
 637         avd->allowed = 0;
 638         avd->auditallow = 0;
 639         avd->auditdeny = 0xffffffff;
 640         if (xperms) {
 641                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 642                 xperms->len = 0;
 643         }
 644
 645         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 646                 if (printk_ratelimit())
 647                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 648                 return;
 649         }
 650
 651         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 652
 653         /*
 654          * If a specific type enforcement rule was defined for
 655          * this permission check, then use it.
 656          */
 657         avkey.target_class = tclass;
 658         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 659         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 660         BUG_ON(!sattr);
 661         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 662         BUG_ON(!tattr);
 663         ebitmap_for_each_positive_bit(sattr, snode, i) {
 664                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 665                         avkey.source_type = i + 1;
 666                         avkey.target_type = j + 1;
 667                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 668                              node;
 669                              node = avtab_search_node_next(node, avkey.specified)) {
 670                                 if (node->key.specified == AVTAB_ALLOWED)
 671                                         avd->allowed |= node->datum.u.data;
 672                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 673                                         avd->auditallow |= node->datum.u.data;
 674                                 else if (node->key.specified == AVTAB_AUDITDENY)
 675                                         avd->auditdeny &= node->datum.u.data;
 676                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 677                                         services_compute_xperms_drivers(xperms, node);
 678                         }
 679
 680                         /* Check conditional av table for additional permissions */
 681                         cond_compute_av(&policydb.te_cond_avtab, &avkey,
 682                                         avd, xperms);
 683
 684                 }
 685         }
 686
 687         /*
 688          * Remove any permissions prohibited by a constraint (this includes
 689          * the MLS policy).
 690          */
 691         constraint = tclass_datum->constraints;
 692         while (constraint) {
 693                 if ((constraint->permissions & (avd->allowed)) &&
 694                     !constraint_expr_eval(scontext, tcontext, NULL,
 695                                           constraint->expr)) {
 696                         avd->allowed &= ~(constraint->permissions);
 697                 }
 698                 constraint = constraint->next;
 699         }
 700
 701         /*
 702          * If checking process transition permission and the
 703          * role is changing, then check the (current_role, new_role)
 704          * pair.
 705          */
 706         if (tclass == policydb.process_class &&
 707             (avd->allowed & policydb.process_trans_perms) &&
 708             scontext->role != tcontext->role) {
 709                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 710                         if (scontext->role == ra->role &&
 711                             tcontext->role == ra->new_role)
 712                                 break;
 713                 }
 714                 if (!ra)
 715                         avd->allowed &= ~policydb.process_trans_perms;
 716         }
 717
 718         /*
 719          * If the given source and target types have boundary
 720          * constraint, lazy checks have to mask any violated
 721          * permission and notice it to userspace via audit.
 722          */
 723         type_attribute_bounds_av(scontext, tcontext,
 724                                  tclass, avd);
 725 }
 726
 727 static int security_validtrans_handle_fail(struct context *ocontext,
 728                                            struct context *ncontext,
 729                                            struct context *tcontext,
 730                                            u16 tclass)
 731 {
 732         char *o = NULL, *n = NULL, *t = NULL;
 733         u32 olen, nlen, tlen;
 734
 735         if (context_struct_to_string(ocontext, &o, &olen))
 736                 goto out;
 737         if (context_struct_to_string(ncontext, &n, &nlen))
 738                 goto out;
 739         if (context_struct_to_string(tcontext, &t, &tlen))
 740                 goto out;
 741         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 742                   "op=security_validate_transition seresult=denied"
 743                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 744                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 745 out:
 746         kfree(o);
 747         kfree(n);
 748         kfree(t);
 749
 750         if (!selinux_enforcing)
 751                 return 0;
 752         return -EPERM;
 753 }
 754
 755 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
 756                                           u16 orig_tclass, bool user)
 757 {
 758         struct context *ocontext;
 759         struct context *ncontext;
 760         struct context *tcontext;
 761         struct class_datum *tclass_datum;
 762         struct constraint_node *constraint;
 763         u16 tclass;
 764         int rc = 0;
 765
 766         if (!ss_initialized)
 767                 return 0;
 768
 769         read_lock(&policy_rwlock);
 770
 771         if (!user)
 772                 tclass = unmap_class(orig_tclass);
 773         else
 774                 tclass = orig_tclass;
 775
 776         if (!tclass || tclass > policydb.p_classes.nprim) {
 777                 rc = -EINVAL;
 778                 goto out;
 779         }
 780         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 781
 782         ocontext = sidtab_search(&sidtab, oldsid);
 783         if (!ocontext) {
 784                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 785                         __func__, oldsid);
 786                 rc = -EINVAL;
 787                 goto out;
 788         }
 789
 790         ncontext = sidtab_search(&sidtab, newsid);
 791         if (!ncontext) {
 792                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 793                         __func__, newsid);
 794                 rc = -EINVAL;
 795                 goto out;
 796         }
 797
 798         tcontext = sidtab_search(&sidtab, tasksid);
 799         if (!tcontext) {
 800                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 801                         __func__, tasksid);
 802                 rc = -EINVAL;
 803                 goto out;
 804         }
 805
 806         constraint = tclass_datum->validatetrans;
 807         while (constraint) {
 808                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 809                                           constraint->expr)) {
 810                         if (user)
 811                                 rc = -EPERM;
 812                         else
 813                                 rc = security_validtrans_handle_fail(ocontext,
 814                                                                      ncontext,
 815                                                                      tcontext,
 816                                                                      tclass);
 817                         goto out;
 818                 }
 819                 constraint = constraint->next;
 820         }
 821
 822 out:
 823         read_unlock(&policy_rwlock);
 824         return rc;
 825 }
 826
 827 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
 828                                         u16 tclass)
 829 {
 830         return security_compute_validatetrans(oldsid, newsid, tasksid,
 831                                                 tclass, true);
 832 }
 833
 834 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 835                                  u16 orig_tclass)
 836 {
 837         return security_compute_validatetrans(oldsid, newsid, tasksid,
 838                                                 orig_tclass, false);
 839 }
 840
 841 /*
 842  * security_bounded_transition - check whether the given
 843  * transition is directed to bounded, or not.
 844  * It returns 0, if @newsid is bounded by @oldsid.
 845  * Otherwise, it returns error code.
 846  *
 847  * @oldsid : current security identifier
 848  * @newsid : destinated security identifier
 849  */
 850 int security_bounded_transition(u32 old_sid, u32 new_sid)
 851 {
 852         struct context *old_context, *new_context;
 853         struct type_datum *type;
 854         int index;
 855         int rc;
 856
 857         if (!ss_initialized)
 858                 return 0;
 859
 860         read_lock(&policy_rwlock);
 861
 862         rc = -EINVAL;
 863         old_context = sidtab_search(&sidtab, old_sid);
 864         if (!old_context) {
 865                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 866                        __func__, old_sid);
 867                 goto out;
 868         }
 869
 870         rc = -EINVAL;
 871         new_context = sidtab_search(&sidtab, new_sid);
 872         if (!new_context) {
 873                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 874                        __func__, new_sid);
 875                 goto out;
 876         }
 877
 878         rc = 0;
 879         /* type/domain unchanged */
 880         if (old_context->type == new_context->type)
 881                 goto out;
 882
 883         index = new_context->type;
 884         while (true) {
 885                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 886                                           index - 1);
 887                 BUG_ON(!type);
 888
 889                 /* not bounded anymore */
 890                 rc = -EPERM;
 891                 if (!type->bounds)
 892                         break;
 893
 894                 /* @newsid is bounded by @oldsid */
 895                 rc = 0;
 896                 if (type->bounds == old_context->type)
 897                         break;
 898
 899                 index = type->bounds;
 900         }
 901
 902         if (rc) {
 903                 char *old_name = NULL;
 904                 char *new_name = NULL;
 905                 u32 length;
 906
 907                 if (!context_struct_to_string(old_context,
 908                                               &old_name, &length) &&
 909                     !context_struct_to_string(new_context,
 910                                               &new_name, &length)) {
 911                         audit_log(current->audit_context,
 912                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 913                                   "op=security_bounded_transition "
 914                                   "seresult=denied "
 915                                   "oldcontext=%s newcontext=%s",
 916                                   old_name, new_name);
 917                 }
 918                 kfree(new_name);
 919                 kfree(old_name);
 920         }
 921 out:
 922         read_unlock(&policy_rwlock);
 923
 924         return rc;
 925 }
 926
 927 static void avd_init(struct av_decision *avd)
 928 {
 929         avd->allowed = 0;
 930         avd->auditallow = 0;
 931         avd->auditdeny = 0xffffffff;
 932         avd->seqno = latest_granting;
 933         avd->flags = 0;
 934 }
 935
 936 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 937                                         struct avtab_node *node)
 938 {
 939         unsigned int i;
 940
 941         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 942                 if (xpermd->driver != node->datum.u.xperms->driver)
 943                         return;
 944         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 945                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 946                                         xpermd->driver))
 947                         return;
 948         } else {
 949                 BUG();
 950         }
 951
 952         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 953                 xpermd->used |= XPERMS_ALLOWED;
 954                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 955                         memset(xpermd->allowed->p, 0xff,
 956                                         sizeof(xpermd->allowed->p));
 957                 }
 958                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 959                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 960                                 xpermd->allowed->p[i] |=
 961                                         node->datum.u.xperms->perms.p[i];
 962                 }
 963         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 964                 xpermd->used |= XPERMS_AUDITALLOW;
 965                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 966                         memset(xpermd->auditallow->p, 0xff,
 967                                         sizeof(xpermd->auditallow->p));
 968                 }
 969                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 970                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 971                                 xpermd->auditallow->p[i] |=
 972                                         node->datum.u.xperms->perms.p[i];
 973                 }
 974         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 975                 xpermd->used |= XPERMS_DONTAUDIT;
 976                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 977                         memset(xpermd->dontaudit->p, 0xff,
 978                                         sizeof(xpermd->dontaudit->p));
 979                 }
 980                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 981                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 982                                 xpermd->dontaudit->p[i] |=
 983                                         node->datum.u.xperms->perms.p[i];
 984                 }
 985         } else {
 986                 BUG();
 987         }
 988 }
 989
 990 void security_compute_xperms_decision(u32 ssid,
 991                                 u32 tsid,
 992                                 u16 orig_tclass,
 993                                 u8 driver,
 994                                 struct extended_perms_decision *xpermd)
 995 {
 996         u16 tclass;
 997         struct context *scontext, *tcontext;
 998         struct avtab_key avkey;
 999         struct avtab_node *node;
1000         struct ebitmap *sattr, *tattr;
1001         struct ebitmap_node *snode, *tnode;
1002         unsigned int i, j;
1003
1004         xpermd->driver = driver;
1005         xpermd->used = 0;
1006         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1007         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1008         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1009
1010         read_lock(&policy_rwlock);
1011         if (!ss_initialized)
1012                 goto allow;
1013
1014         scontext = sidtab_search(&sidtab, ssid);
1015         if (!scontext) {
1016                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1017                        __func__, ssid);
1018                 goto out;
1019         }
1020
1021         tcontext = sidtab_search(&sidtab, tsid);
1022         if (!tcontext) {
1023                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1024                        __func__, tsid);
1025                 goto out;
1026         }
1027
1028         tclass = unmap_class(orig_tclass);
1029         if (unlikely(orig_tclass && !tclass)) {
1030                 if (policydb.allow_unknown)
1031                         goto allow;
1032                 goto out;
1033         }
1034
1035
1036         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1037                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1038                 goto out;
1039         }
1040
1041         avkey.target_class = tclass;
1042         avkey.specified = AVTAB_XPERMS;
1043         sattr = flex_array_get(policydb.type_attr_map_array,
1044                                 scontext->type - 1);
1045         BUG_ON(!sattr);
1046         tattr = flex_array_get(policydb.type_attr_map_array,
1047                                 tcontext->type - 1);
1048         BUG_ON(!tattr);
1049         ebitmap_for_each_positive_bit(sattr, snode, i) {
1050                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1051                         avkey.source_type = i + 1;
1052                         avkey.target_type = j + 1;
1053                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1054                              node;
1055                              node = avtab_search_node_next(node, avkey.specified))
1056                                 services_compute_xperms_decision(xpermd, node);
1057
1058                         cond_compute_xperms(&policydb.te_cond_avtab,
1059                                                 &avkey, xpermd);
1060                 }
1061         }
1062 out:
1063         read_unlock(&policy_rwlock);
1064         return;
1065 allow:
1066         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1067         goto out;
1068 }
1069
1070 /**
1071  * security_compute_av - Compute access vector decisions.
1072  * @ssid: source security identifier
1073  * @tsid: target security identifier
1074  * @tclass: target security class
1075  * @avd: access vector decisions
1076  * @xperms: extended permissions
1077  *
1078  * Compute a set of access vector decisions based on the
1079  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1080  */
1081 void security_compute_av(u32 ssid,
1082                          u32 tsid,
1083                          u16 orig_tclass,
1084                          struct av_decision *avd,
1085                          struct extended_perms *xperms)
1086 {
1087         u16 tclass;
1088         struct context *scontext = NULL, *tcontext = NULL;
1089
1090         read_lock(&policy_rwlock);
1091         avd_init(avd);
1092         xperms->len = 0;
1093         if (!ss_initialized)
1094                 goto allow;
1095
1096         scontext = sidtab_search(&sidtab, ssid);
1097         if (!scontext) {
1098                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1099                        __func__, ssid);
1100                 goto out;
1101         }
1102
1103         /* permissive domain? */
1104         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1105                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1106
1107         tcontext = sidtab_search(&sidtab, tsid);
1108         if (!tcontext) {
1109                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1110                        __func__, tsid);
1111                 goto out;
1112         }
1113
1114         tclass = unmap_class(orig_tclass);
1115         if (unlikely(orig_tclass && !tclass)) {
1116                 if (policydb.allow_unknown)
1117                         goto allow;
1118                 goto out;
1119         }
1120         context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1121         map_decision(orig_tclass, avd, policydb.allow_unknown);
1122 out:
1123         read_unlock(&policy_rwlock);
1124         return;
1125 allow:
1126         avd->allowed = 0xffffffff;
1127         goto out;
1128 }
1129
1130 void security_compute_av_user(u32 ssid,
1131                               u32 tsid,
1132                               u16 tclass,
1133                               struct av_decision *avd)
1134 {
1135         struct context *scontext = NULL, *tcontext = NULL;
1136
1137         read_lock(&policy_rwlock);
1138         avd_init(avd);
1139         if (!ss_initialized)
1140                 goto allow;
1141
1142         scontext = sidtab_search(&sidtab, ssid);
1143         if (!scontext) {
1144                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1145                        __func__, ssid);
1146                 goto out;
1147         }
1148
1149         /* permissive domain? */
1150         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1151                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1152
1153         tcontext = sidtab_search(&sidtab, tsid);
1154         if (!tcontext) {
1155                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1156                        __func__, tsid);
1157                 goto out;
1158         }
1159
1160         if (unlikely(!tclass)) {
1161                 if (policydb.allow_unknown)
1162                         goto allow;
1163                 goto out;
1164         }
1165
1166         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1167  out:
1168         read_unlock(&policy_rwlock);
1169         return;
1170 allow:
1171         avd->allowed = 0xffffffff;
1172         goto out;
1173 }
1174
1175 /*
1176  * Write the security context string representation of
1177  * the context structure `context' into a dynamically
1178  * allocated string of the correct size.  Set `*scontext'
1179  * to point to this string and set `*scontext_len' to
1180  * the length of the string.
1181  */
1182 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1183 {
1184         char *scontextp;
1185
1186         if (scontext)
1187                 *scontext = NULL;
1188         *scontext_len = 0;
1189
1190         if (context->len) {
1191                 *scontext_len = context->len;
1192                 if (scontext) {
1193                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1194                         if (!(*scontext))
1195                                 return -ENOMEM;
1196                 }
1197                 return 0;
1198         }
1199
1200         /* Compute the size of the context. */
1201         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1202         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1203         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1204         *scontext_len += mls_compute_context_len(context);
1205
1206         if (!scontext)
1207                 return 0;
1208
1209         /* Allocate space for the context; caller must free this space. */
1210         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1211         if (!scontextp)
1212                 return -ENOMEM;
1213         *scontext = scontextp;
1214
1215         /*
1216          * Copy the user name, role name and type name into the context.
1217          */
1218         scontextp += sprintf(scontextp, "%s:%s:%s",
1219                 sym_name(&policydb, SYM_USERS, context->user - 1),
1220                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1221                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1222
1223         mls_sid_to_context(context, &scontextp);
1224
1225         *scontextp = 0;
1226
1227         return 0;
1228 }
1229
1230 #include "initial_sid_to_string.h"
1231
1232 const char *security_get_initial_sid_context(u32 sid)
1233 {
1234         if (unlikely(sid > SECINITSID_NUM))
1235                 return NULL;
1236         return initial_sid_to_string[sid];
1237 }
1238
1239 static int security_sid_to_context_core(u32 sid, char **scontext,
1240                                         u32 *scontext_len, int force)
1241 {
1242         struct context *context;
1243         int rc = 0;
1244
1245         if (scontext)
1246                 *scontext = NULL;
1247         *scontext_len  = 0;
1248
1249         if (!ss_initialized) {
1250                 if (sid <= SECINITSID_NUM) {
1251                         char *scontextp;
1252
1253                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1254                         if (!scontext)
1255                                 goto out;
1256                         scontextp = kmemdup(initial_sid_to_string[sid],
1257                                             *scontext_len, GFP_ATOMIC);
1258                         if (!scontextp) {
1259                                 rc = -ENOMEM;
1260                                 goto out;
1261                         }
1262                         *scontext = scontextp;
1263                         goto out;
1264                 }
1265                 printk(KERN_ERR "SELinux: %s:  called before initial "
1266                        "load_policy on unknown SID %d\n", __func__, sid);
1267                 rc = -EINVAL;
1268                 goto out;
1269         }
1270         read_lock(&policy_rwlock);
1271         if (force)
1272                 context = sidtab_search_force(&sidtab, sid);
1273         else
1274                 context = sidtab_search(&sidtab, sid);
1275         if (!context) {
1276                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1277                         __func__, sid);
1278                 rc = -EINVAL;
1279                 goto out_unlock;
1280         }
1281         rc = context_struct_to_string(context, scontext, scontext_len);
1282 out_unlock:
1283         read_unlock(&policy_rwlock);
1284 out:
1285         return rc;
1286
1287 }
1288
1289 /**
1290  * security_sid_to_context - Obtain a context for a given SID.
1291  * @sid: security identifier, SID
1292  * @scontext: security context
1293  * @scontext_len: length in bytes
1294  *
1295  * Write the string representation of the context associated with @sid
1296  * into a dynamically allocated string of the correct size.  Set @scontext
1297  * to point to this string and set @scontext_len to the length of the string.
1298  */
1299 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1300 {
1301         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1302 }
1303
1304 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1305 {
1306         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1307 }
1308
1309 /*
1310  * Caveat:  Mutates scontext.
1311  */
1312 static int string_to_context_struct(struct policydb *pol,
1313                                     struct sidtab *sidtabp,
1314                                     char *scontext,
1315                                     u32 scontext_len,
1316                                     struct context *ctx,
1317                                     u32 def_sid)
1318 {
1319         struct role_datum *role;
1320         struct type_datum *typdatum;
1321         struct user_datum *usrdatum;
1322         char *scontextp, *p, oldc;
1323         int rc = 0;
1324
1325         context_init(ctx);
1326
1327         /* Parse the security context. */
1328
1329         rc = -EINVAL;
1330         scontextp = (char *) scontext;
1331
1332         /* Extract the user. */
1333         p = scontextp;
1334         while (*p && *p != ':')
1335                 p++;
1336
1337         if (*p == 0)
1338                 goto out;
1339
1340         *p++ = 0;
1341
1342         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1343         if (!usrdatum)
1344                 goto out;
1345
1346         ctx->user = usrdatum->value;
1347
1348         /* Extract role. */
1349         scontextp = p;
1350         while (*p && *p != ':')
1351                 p++;
1352
1353         if (*p == 0)
1354                 goto out;
1355
1356         *p++ = 0;
1357
1358         role = hashtab_search(pol->p_roles.table, scontextp);
1359         if (!role)
1360                 goto out;
1361         ctx->role = role->value;
1362
1363         /* Extract type. */
1364         scontextp = p;
1365         while (*p && *p != ':')
1366                 p++;
1367         oldc = *p;
1368         *p++ = 0;
1369
1370         typdatum = hashtab_search(pol->p_types.table, scontextp);
1371         if (!typdatum || typdatum->attribute)
1372                 goto out;
1373
1374         ctx->type = typdatum->value;
1375
1376         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1377         if (rc)
1378                 goto out;
1379
1380         rc = -EINVAL;
1381         if ((p - scontext) < scontext_len)
1382                 goto out;
1383
1384         /* Check the validity of the new context. */
1385         if (!policydb_context_isvalid(pol, ctx))
1386                 goto out;
1387         rc = 0;
1388 out:
1389         if (rc)
1390                 context_destroy(ctx);
1391         return rc;
1392 }
1393
1394 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1395                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1396                                         int force)
1397 {
1398         char *scontext2, *str = NULL;
1399         struct context context;
1400         int rc = 0;
1401
1402         /* An empty security context is never valid. */
1403         if (!scontext_len)
1404                 return -EINVAL;
1405
1406         /* Copy the string to allow changes and ensure a NUL terminator */
1407         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1408         if (!scontext2)
1409                 return -ENOMEM;
1410
1411         if (!ss_initialized) {
1412                 int i;
1413
1414                 for (i = 1; i < SECINITSID_NUM; i++) {
1415                         if (!strcmp(initial_sid_to_string[i], scontext2)) {
1416                                 *sid = i;
1417                                 goto out;
1418                         }
1419                 }
1420                 *sid = SECINITSID_KERNEL;
1421                 goto out;
1422         }
1423         *sid = SECSID_NULL;
1424
1425         if (force) {
1426                 /* Save another copy for storing in uninterpreted form */
1427                 rc = -ENOMEM;
1428                 str = kstrdup(scontext2, gfp_flags);
1429                 if (!str)
1430                         goto out;
1431         }
1432
1433         read_lock(&policy_rwlock);
1434         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1435                                       scontext_len, &context, def_sid);
1436         if (rc == -EINVAL && force) {
1437                 context.str = str;
1438                 context.len = strlen(str) + 1;
1439                 str = NULL;
1440         } else if (rc)
1441                 goto out_unlock;
1442         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1443         context_destroy(&context);
1444 out_unlock:
1445         read_unlock(&policy_rwlock);
1446 out:
1447         kfree(scontext2);
1448         kfree(str);
1449         return rc;
1450 }
1451
1452 /**
1453  * security_context_to_sid - Obtain a SID for a given security context.
1454  * @scontext: security context
1455  * @scontext_len: length in bytes
1456  * @sid: security identifier, SID
1457  * @gfp: context for the allocation
1458  *
1459  * Obtains a SID associated with the security context that
1460  * has the string representation specified by @scontext.
1461  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1462  * memory is available, or 0 on success.
1463  */
1464 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1465                             gfp_t gfp)
1466 {
1467         return security_context_to_sid_core(scontext, scontext_len,
1468                                             sid, SECSID_NULL, gfp, 0);
1469 }
1470
1471 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1472 {
1473         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1474 }
1475
1476 /**
1477  * security_context_to_sid_default - Obtain a SID for a given security context,
1478  * falling back to specified default if needed.
1479  *
1480  * @scontext: security context
1481  * @scontext_len: length in bytes
1482  * @sid: security identifier, SID
1483  * @def_sid: default SID to assign on error
1484  *
1485  * Obtains a SID associated with the security context that
1486  * has the string representation specified by @scontext.
1487  * The default SID is passed to the MLS layer to be used to allow
1488  * kernel labeling of the MLS field if the MLS field is not present
1489  * (for upgrading to MLS without full relabel).
1490  * Implicitly forces adding of the context even if it cannot be mapped yet.
1491  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1492  * memory is available, or 0 on success.
1493  */
1494 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1495                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1496 {
1497         return security_context_to_sid_core(scontext, scontext_len,
1498                                             sid, def_sid, gfp_flags, 1);
1499 }
1500
1501 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1502                                   u32 *sid)
1503 {
1504         return security_context_to_sid_core(scontext, scontext_len,
1505                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1506 }
1507
1508 static int compute_sid_handle_invalid_context(
1509         struct context *scontext,
1510         struct context *tcontext,
1511         u16 tclass,
1512         struct context *newcontext)
1513 {
1514         char *s = NULL, *t = NULL, *n = NULL;
1515         u32 slen, tlen, nlen;
1516
1517         if (context_struct_to_string(scontext, &s, &slen))
1518                 goto out;
1519         if (context_struct_to_string(tcontext, &t, &tlen))
1520                 goto out;
1521         if (context_struct_to_string(newcontext, &n, &nlen))
1522                 goto out;
1523         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1524                   "op=security_compute_sid invalid_context=%s"
1525                   " scontext=%s"
1526                   " tcontext=%s"
1527                   " tclass=%s",
1528                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1529 out:
1530         kfree(s);
1531         kfree(t);
1532         kfree(n);
1533         if (!selinux_enforcing)
1534                 return 0;
1535         return -EACCES;
1536 }
1537
1538 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1539                                   u32 stype, u32 ttype, u16 tclass,
1540                                   const char *objname)
1541 {
1542         struct filename_trans ft;
1543         struct filename_trans_datum *otype;
1544
1545         /*
1546          * Most filename trans rules are going to live in specific directories
1547          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1548          * if the ttype does not contain any rules.
1549          */
1550         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1551                 return;
1552
1553         ft.stype = stype;
1554         ft.ttype = ttype;
1555         ft.tclass = tclass;
1556         ft.name = objname;
1557
1558         otype = hashtab_search(p->filename_trans, &ft);
1559         if (otype)
1560                 newcontext->type = otype->otype;
1561 }
1562
1563 static int security_compute_sid(u32 ssid,
1564                                 u32 tsid,
1565                                 u16 orig_tclass,
1566                                 u32 specified,
1567                                 const char *objname,
1568                                 u32 *out_sid,
1569                                 bool kern)
1570 {
1571         struct class_datum *cladatum = NULL;
1572         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1573         struct role_trans *roletr = NULL;
1574         struct avtab_key avkey;
1575         struct avtab_datum *avdatum;
1576         struct avtab_node *node;
1577         u16 tclass;
1578         int rc = 0;
1579         bool sock;
1580
1581         if (!ss_initialized) {
1582                 switch (orig_tclass) {
1583                 case SECCLASS_PROCESS: /* kernel value */
1584                         *out_sid = ssid;
1585                         break;
1586                 default:
1587                         *out_sid = tsid;
1588                         break;
1589                 }
1590                 goto out;
1591         }
1592
1593         context_init(&newcontext);
1594
1595         read_lock(&policy_rwlock);
1596
1597         if (kern) {
1598                 tclass = unmap_class(orig_tclass);
1599                 sock = security_is_socket_class(orig_tclass);
1600         } else {
1601                 tclass = orig_tclass;
1602                 sock = security_is_socket_class(map_class(tclass));
1603         }
1604
1605         scontext = sidtab_search(&sidtab, ssid);
1606         if (!scontext) {
1607                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1608                        __func__, ssid);
1609                 rc = -EINVAL;
1610                 goto out_unlock;
1611         }
1612         tcontext = sidtab_search(&sidtab, tsid);
1613         if (!tcontext) {
1614                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1615                        __func__, tsid);
1616                 rc = -EINVAL;
1617                 goto out_unlock;
1618         }
1619
1620         if (tclass && tclass <= policydb.p_classes.nprim)
1621                 cladatum = policydb.class_val_to_struct[tclass - 1];
1622
1623         /* Set the user identity. */
1624         switch (specified) {
1625         case AVTAB_TRANSITION:
1626         case AVTAB_CHANGE:
1627                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1628                         newcontext.user = tcontext->user;
1629                 } else {
1630                         /* notice this gets both DEFAULT_SOURCE and unset */
1631                         /* Use the process user identity. */
1632                         newcontext.user = scontext->user;
1633                 }
1634                 break;
1635         case AVTAB_MEMBER:
1636                 /* Use the related object owner. */
1637                 newcontext.user = tcontext->user;
1638                 break;
1639         }
1640
1641         /* Set the role to default values. */
1642         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1643                 newcontext.role = scontext->role;
1644         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1645                 newcontext.role = tcontext->role;
1646         } else {
1647                 if ((tclass == policydb.process_class) || (sock == true))
1648                         newcontext.role = scontext->role;
1649                 else
1650                         newcontext.role = OBJECT_R_VAL;
1651         }
1652
1653         /* Set the type to default values. */
1654         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1655                 newcontext.type = scontext->type;
1656         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1657                 newcontext.type = tcontext->type;
1658         } else {
1659                 if ((tclass == policydb.process_class) || (sock == true)) {
1660                         /* Use the type of process. */
1661                         newcontext.type = scontext->type;
1662                 } else {
1663                         /* Use the type of the related object. */
1664                         newcontext.type = tcontext->type;
1665                 }
1666         }
1667
1668         /* Look for a type transition/member/change rule. */
1669         avkey.source_type = scontext->type;
1670         avkey.target_type = tcontext->type;
1671         avkey.target_class = tclass;
1672         avkey.specified = specified;
1673         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1674
1675         /* If no permanent rule, also check for enabled conditional rules */
1676         if (!avdatum) {
1677                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1678                 for (; node; node = avtab_search_node_next(node, specified)) {
1679                         if (node->key.specified & AVTAB_ENABLED) {
1680                                 avdatum = &node->datum;
1681                                 break;
1682                         }
1683                 }
1684         }
1685
1686         if (avdatum) {
1687                 /* Use the type from the type transition/member/change rule. */
1688                 newcontext.type = avdatum->u.data;
1689         }
1690
1691         /* if we have a objname this is a file trans check so check those rules */
1692         if (objname)
1693                 filename_compute_type(&policydb, &newcontext, scontext->type,
1694                                       tcontext->type, tclass, objname);
1695
1696         /* Check for class-specific changes. */
1697         if (specified & AVTAB_TRANSITION) {
1698                 /* Look for a role transition rule. */
1699                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1700                         if ((roletr->role == scontext->role) &&
1701                             (roletr->type == tcontext->type) &&
1702                             (roletr->tclass == tclass)) {
1703                                 /* Use the role transition rule. */
1704                                 newcontext.role = roletr->new_role;
1705                                 break;
1706                         }
1707                 }
1708         }
1709
1710         /* Set the MLS attributes.
1711            This is done last because it may allocate memory. */
1712         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1713                              &newcontext, sock);
1714         if (rc)
1715                 goto out_unlock;
1716
1717         /* Check the validity of the context. */
1718         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1719                 rc = compute_sid_handle_invalid_context(scontext,
1720                                                         tcontext,
1721                                                         tclass,
1722                                                         &newcontext);
1723                 if (rc)
1724                         goto out_unlock;
1725         }
1726         /* Obtain the sid for the context. */
1727         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1728 out_unlock:
1729         read_unlock(&policy_rwlock);
1730         context_destroy(&newcontext);
1731 out:
1732         return rc;
1733 }
1734
1735 /**
1736  * security_transition_sid - Compute the SID for a new subject/object.
1737  * @ssid: source security identifier
1738  * @tsid: target security identifier
1739  * @tclass: target security class
1740  * @out_sid: security identifier for new subject/object
1741  *
1742  * Compute a SID to use for labeling a new subject or object in the
1743  * class @tclass based on a SID pair (@ssid, @tsid).
1744  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1745  * if insufficient memory is available, or %0 if the new SID was
1746  * computed successfully.
1747  */
1748 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1749                             const struct qstr *qstr, u32 *out_sid)
1750 {
1751         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1752                                     qstr ? qstr->name : NULL, out_sid, true);
1753 }
1754
1755 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1756                                  const char *objname, u32 *out_sid)
1757 {
1758         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1759                                     objname, out_sid, false);
1760 }
1761
1762 /**
1763  * security_member_sid - Compute the SID for member selection.
1764  * @ssid: source security identifier
1765  * @tsid: target security identifier
1766  * @tclass: target security class
1767  * @out_sid: security identifier for selected member
1768  *
1769  * Compute a SID to use when selecting a member of a polyinstantiated
1770  * object of class @tclass based on a SID pair (@ssid, @tsid).
1771  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1772  * if insufficient memory is available, or %0 if the SID was
1773  * computed successfully.
1774  */
1775 int security_member_sid(u32 ssid,
1776                         u32 tsid,
1777                         u16 tclass,
1778                         u32 *out_sid)
1779 {
1780         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1781                                     out_sid, false);
1782 }
1783
1784 /**
1785  * security_change_sid - Compute the SID for object relabeling.
1786  * @ssid: source security identifier
1787  * @tsid: target security identifier
1788  * @tclass: target security class
1789  * @out_sid: security identifier for selected member
1790  *
1791  * Compute a SID to use for relabeling an object of class @tclass
1792  * based on a SID pair (@ssid, @tsid).
1793  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1794  * if insufficient memory is available, or %0 if the SID was
1795  * computed successfully.
1796  */
1797 int security_change_sid(u32 ssid,
1798                         u32 tsid,
1799                         u16 tclass,
1800                         u32 *out_sid)
1801 {
1802         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1803                                     out_sid, false);
1804 }
1805
1806 /* Clone the SID into the new SID table. */
1807 static int clone_sid(u32 sid,
1808                      struct context *context,
1809                      void *arg)
1810 {
1811         struct sidtab *s = arg;
1812
1813         if (sid > SECINITSID_NUM)
1814                 return sidtab_insert(s, sid, context);
1815         else
1816                 return 0;
1817 }
1818
1819 static inline int convert_context_handle_invalid_context(struct context *context)
1820 {
1821         char *s;
1822         u32 len;
1823
1824         if (selinux_enforcing)
1825                 return -EINVAL;
1826
1827         if (!context_struct_to_string(context, &s, &len)) {
1828                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1829                 kfree(s);
1830         }
1831         return 0;
1832 }
1833
1834 struct convert_context_args {
1835         struct policydb *oldp;
1836         struct policydb *newp;
1837 };
1838
1839 /*
1840  * Convert the values in the security context
1841  * structure `c' from the values specified
1842  * in the policy `p->oldp' to the values specified
1843  * in the policy `p->newp'.  Verify that the
1844  * context is valid under the new policy.
1845  */
1846 static int convert_context(u32 key,
1847                            struct context *c,
1848                            void *p)
1849 {
1850         struct convert_context_args *args;
1851         struct context oldc;
1852         struct ocontext *oc;
1853         struct mls_range *range;
1854         struct role_datum *role;
1855         struct type_datum *typdatum;
1856         struct user_datum *usrdatum;
1857         char *s;
1858         u32 len;
1859         int rc = 0;
1860
1861         if (key <= SECINITSID_NUM)
1862                 goto out;
1863
1864         args = p;
1865
1866         if (c->str) {
1867                 struct context ctx;
1868
1869                 rc = -ENOMEM;
1870                 s = kstrdup(c->str, GFP_KERNEL);
1871                 if (!s)
1872                         goto out;
1873
1874                 rc = string_to_context_struct(args->newp, NULL, s,
1875                                               c->len, &ctx, SECSID_NULL);
1876                 kfree(s);
1877                 if (!rc) {
1878                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1879                                c->str);
1880                         /* Replace string with mapped representation. */
1881                         kfree(c->str);
1882                         memcpy(c, &ctx, sizeof(*c));
1883                         goto out;
1884                 } else if (rc == -EINVAL) {
1885                         /* Retain string representation for later mapping. */
1886                         rc = 0;
1887                         goto out;
1888                 } else {
1889                         /* Other error condition, e.g. ENOMEM. */
1890                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1891                                c->str, -rc);
1892                         goto out;
1893                 }
1894         }
1895
1896         rc = context_cpy(&oldc, c);
1897         if (rc)
1898                 goto out;
1899
1900         /* Convert the user. */
1901         rc = -EINVAL;
1902         usrdatum = hashtab_search(args->newp->p_users.table,
1903                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1904         if (!usrdatum)
1905                 goto bad;
1906         c->user = usrdatum->value;
1907
1908         /* Convert the role. */
1909         rc = -EINVAL;
1910         role = hashtab_search(args->newp->p_roles.table,
1911                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1912         if (!role)
1913                 goto bad;
1914         c->role = role->value;
1915
1916         /* Convert the type. */
1917         rc = -EINVAL;
1918         typdatum = hashtab_search(args->newp->p_types.table,
1919                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1920         if (!typdatum)
1921                 goto bad;
1922         c->type = typdatum->value;
1923
1924         /* Convert the MLS fields if dealing with MLS policies */
1925         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1926                 rc = mls_convert_context(args->oldp, args->newp, c);
1927                 if (rc)
1928                         goto bad;
1929         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1930                 /*
1931                  * Switching between MLS and non-MLS policy:
1932                  * free any storage used by the MLS fields in the
1933                  * context for all existing entries in the sidtab.
1934                  */
1935                 mls_context_destroy(c);
1936         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1937                 /*
1938                  * Switching between non-MLS and MLS policy:
1939                  * ensure that the MLS fields of the context for all
1940                  * existing entries in the sidtab are filled in with a
1941                  * suitable default value, likely taken from one of the
1942                  * initial SIDs.
1943                  */
1944                 oc = args->newp->ocontexts[OCON_ISID];
1945                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1946                         oc = oc->next;
1947                 rc = -EINVAL;
1948                 if (!oc) {
1949                         printk(KERN_ERR "SELinux:  unable to look up"
1950                                 " the initial SIDs list\n");
1951                         goto bad;
1952                 }
1953                 range = &oc->context[0].range;
1954                 rc = mls_range_set(c, range);
1955                 if (rc)
1956                         goto bad;
1957         }
1958
1959         /* Check the validity of the new context. */
1960         if (!policydb_context_isvalid(args->newp, c)) {
1961                 rc = convert_context_handle_invalid_context(&oldc);
1962                 if (rc)
1963                         goto bad;
1964         }
1965
1966         context_destroy(&oldc);
1967
1968         rc = 0;
1969 out:
1970         return rc;
1971 bad:
1972         /* Map old representation to string and save it. */
1973         rc = context_struct_to_string(&oldc, &s, &len);
1974         if (rc)
1975                 return rc;
1976         context_destroy(&oldc);
1977         context_destroy(c);
1978         c->str = s;
1979         c->len = len;
1980         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1981                c->str);
1982         rc = 0;
1983         goto out;
1984 }
1985
1986 static void security_load_policycaps(void)
1987 {
1988         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1989                                                   POLICYDB_CAPABILITY_NETPEER);
1990         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1991                                                   POLICYDB_CAPABILITY_OPENPERM);
1992         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1993                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1994 }
1995
1996 static int security_preserve_bools(struct policydb *p);
1997
1998 /**
1999  * security_load_policy - Load a security policy configuration.
2000  * @data: binary policy data
2001  * @len: length of data in bytes
2002  *
2003  * Load a new set of security policy configuration data,
2004  * validate it and convert the SID table as necessary.
2005  * This function will flush the access vector cache after
2006  * loading the new policy.
2007  */
2008 int security_load_policy(void *data, size_t len)
2009 {
2010         struct policydb *oldpolicydb, *newpolicydb;
2011         struct sidtab oldsidtab, newsidtab;
2012         struct selinux_mapping *oldmap, *map = NULL;
2013         struct convert_context_args args;
2014         u32 seqno;
2015         u16 map_size;
2016         int rc = 0;
2017         struct policy_file file = { data, len }, *fp = &file;
2018
2019         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2020         if (!oldpolicydb) {
2021                 rc = -ENOMEM;
2022                 goto out;
2023         }
2024         newpolicydb = oldpolicydb + 1;
2025
2026         if (!ss_initialized) {
2027                 avtab_cache_init();
2028                 rc = policydb_read(&policydb, fp);
2029                 if (rc) {
2030                         avtab_cache_destroy();
2031                         goto out;
2032                 }
2033
2034                 policydb.len = len;
2035                 rc = selinux_set_mapping(&policydb, secclass_map,
2036                                          &current_mapping,
2037                                          &current_mapping_size);
2038                 if (rc) {
2039                         policydb_destroy(&policydb);
2040                         avtab_cache_destroy();
2041                         goto out;
2042                 }
2043
2044                 rc = policydb_load_isids(&policydb, &sidtab);
2045                 if (rc) {
2046                         policydb_destroy(&policydb);
2047                         avtab_cache_destroy();
2048                         goto out;
2049                 }
2050
2051                 security_load_policycaps();
2052                 ss_initialized = 1;
2053                 seqno = ++latest_granting;
2054                 selinux_complete_init();
2055                 avc_ss_reset(seqno);
2056                 selnl_notify_policyload(seqno);
2057                 selinux_status_update_policyload(seqno);
2058                 selinux_netlbl_cache_invalidate();
2059                 selinux_xfrm_notify_policyload();
2060                 goto out;
2061         }
2062
2063 #if 0
2064         sidtab_hash_eval(&sidtab, "sids");
2065 #endif
2066
2067         rc = policydb_read(newpolicydb, fp);
2068         if (rc)
2069                 goto out;
2070
2071         newpolicydb->len = len;
2072         /* If switching between different policy types, log MLS status */
2073         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2074                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2075         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2076                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2077
2078         rc = policydb_load_isids(newpolicydb, &newsidtab);
2079         if (rc) {
2080                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2081                 policydb_destroy(newpolicydb);
2082                 goto out;
2083         }
2084
2085         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2086         if (rc)
2087                 goto err;
2088
2089         rc = security_preserve_bools(newpolicydb);
2090         if (rc) {
2091                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2092                 goto err;
2093         }
2094
2095         /* Clone the SID table. */
2096         sidtab_shutdown(&sidtab);
2097
2098         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2099         if (rc)
2100                 goto err;
2101
2102         /*
2103          * Convert the internal representations of contexts
2104          * in the new SID table.
2105          */
2106         args.oldp = &policydb;
2107         args.newp = newpolicydb;
2108         rc = sidtab_map(&newsidtab, convert_context, &args);
2109         if (rc) {
2110                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2111                         " representation of contexts in the new SID"
2112                         " table\n");
2113                 goto err;
2114         }
2115
2116         /* Save the old policydb and SID table to free later. */
2117         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2118         sidtab_set(&oldsidtab, &sidtab);
2119
2120         /* Install the new policydb and SID table. */
2121         write_lock_irq(&policy_rwlock);
2122         memcpy(&policydb, newpolicydb, sizeof(policydb));
2123         sidtab_set(&sidtab, &newsidtab);
2124         security_load_policycaps();
2125         oldmap = current_mapping;
2126         current_mapping = map;
2127         current_mapping_size = map_size;
2128         seqno = ++latest_granting;
2129         write_unlock_irq(&policy_rwlock);
2130
2131         /* Free the old policydb and SID table. */
2132         policydb_destroy(oldpolicydb);
2133         sidtab_destroy(&oldsidtab);
2134         kfree(oldmap);
2135
2136         avc_ss_reset(seqno);
2137         selnl_notify_policyload(seqno);
2138         selinux_status_update_policyload(seqno);
2139         selinux_netlbl_cache_invalidate();
2140         selinux_xfrm_notify_policyload();
2141
2142         rc = 0;
2143         goto out;
2144
2145 err:
2146         kfree(map);
2147         sidtab_destroy(&newsidtab);
2148         policydb_destroy(newpolicydb);
2149
2150 out:
2151         kfree(oldpolicydb);
2152         return rc;
2153 }
2154
2155 size_t security_policydb_len(void)
2156 {
2157         size_t len;
2158
2159         read_lock(&policy_rwlock);
2160         len = policydb.len;
2161         read_unlock(&policy_rwlock);
2162
2163         return len;
2164 }
2165
2166 /**
2167  * security_port_sid - Obtain the SID for a port.
2168  * @protocol: protocol number
2169  * @port: port number
2170  * @out_sid: security identifier
2171  */
2172 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2173 {
2174         struct ocontext *c;
2175         int rc = 0;
2176
2177         read_lock(&policy_rwlock);
2178
2179         c = policydb.ocontexts[OCON_PORT];
2180         while (c) {
2181                 if (c->u.port.protocol == protocol &&
2182                     c->u.port.low_port <= port &&
2183                     c->u.port.high_port >= port)
2184                         break;
2185                 c = c->next;
2186         }
2187
2188         if (c) {
2189                 if (!c->sid[0]) {
2190                         rc = sidtab_context_to_sid(&sidtab,
2191                                                    &c->context[0],
2192                                                    &c->sid[0]);
2193                         if (rc)
2194                                 goto out;
2195                 }
2196                 *out_sid = c->sid[0];
2197         } else {
2198                 *out_sid = SECINITSID_PORT;
2199         }
2200
2201 out:
2202         read_unlock(&policy_rwlock);
2203         return rc;
2204 }
2205
2206 /**
2207  * security_netif_sid - Obtain the SID for a network interface.
2208  * @name: interface name
2209  * @if_sid: interface SID
2210  */
2211 int security_netif_sid(char *name, u32 *if_sid)
2212 {
2213         int rc = 0;
2214         struct ocontext *c;
2215
2216         read_lock(&policy_rwlock);
2217
2218         c = policydb.ocontexts[OCON_NETIF];
2219         while (c) {
2220                 if (strcmp(name, c->u.name) == 0)
2221                         break;
2222                 c = c->next;
2223         }
2224
2225         if (c) {
2226                 if (!c->sid[0] || !c->sid[1]) {
2227                         rc = sidtab_context_to_sid(&sidtab,
2228                                                   &c->context[0],
2229                                                   &c->sid[0]);
2230                         if (rc)
2231                                 goto out;
2232                         rc = sidtab_context_to_sid(&sidtab,
2233                                                    &c->context[1],
2234                                                    &c->sid[1]);
2235                         if (rc)
2236                                 goto out;
2237                 }
2238                 *if_sid = c->sid[0];
2239         } else
2240                 *if_sid = SECINITSID_NETIF;
2241
2242 out:
2243         read_unlock(&policy_rwlock);
2244         return rc;
2245 }
2246
2247 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2248 {
2249         int i, fail = 0;
2250
2251         for (i = 0; i < 4; i++)
2252                 if (addr[i] != (input[i] & mask[i])) {
2253                         fail = 1;
2254                         break;
2255                 }
2256
2257         return !fail;
2258 }
2259
2260 /**
2261  * security_node_sid - Obtain the SID for a node (host).
2262  * @domain: communication domain aka address family
2263  * @addrp: address
2264  * @addrlen: address length in bytes
2265  * @out_sid: security identifier
2266  */
2267 int security_node_sid(u16 domain,
2268                       void *addrp,
2269                       u32 addrlen,
2270                       u32 *out_sid)
2271 {
2272         int rc;
2273         struct ocontext *c;
2274
2275         read_lock(&policy_rwlock);
2276
2277         switch (domain) {
2278         case AF_INET: {
2279                 u32 addr;
2280
2281                 rc = -EINVAL;
2282                 if (addrlen != sizeof(u32))
2283                         goto out;
2284
2285                 addr = *((u32 *)addrp);
2286
2287                 c = policydb.ocontexts[OCON_NODE];
2288                 while (c) {
2289                         if (c->u.node.addr == (addr & c->u.node.mask))
2290                                 break;
2291                         c = c->next;
2292                 }
2293                 break;
2294         }
2295
2296         case AF_INET6:
2297                 rc = -EINVAL;
2298                 if (addrlen != sizeof(u64) * 2)
2299                         goto out;
2300                 c = policydb.ocontexts[OCON_NODE6];
2301                 while (c) {
2302                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2303                                                 c->u.node6.mask))
2304                                 break;
2305                         c = c->next;
2306                 }
2307                 break;
2308
2309         default:
2310                 rc = 0;
2311                 *out_sid = SECINITSID_NODE;
2312                 goto out;
2313         }
2314
2315         if (c) {
2316                 if (!c->sid[0]) {
2317                         rc = sidtab_context_to_sid(&sidtab,
2318                                                    &c->context[0],
2319                                                    &c->sid[0]);
2320                         if (rc)
2321                                 goto out;
2322                 }
2323                 *out_sid = c->sid[0];
2324         } else {
2325                 *out_sid = SECINITSID_NODE;
2326         }
2327
2328         rc = 0;
2329 out:
2330         read_unlock(&policy_rwlock);
2331         return rc;
2332 }
2333
2334 #define SIDS_NEL 25
2335
2336 /**
2337  * security_get_user_sids - Obtain reachable SIDs for a user.
2338  * @fromsid: starting SID
2339  * @username: username
2340  * @sids: array of reachable SIDs for user
2341  * @nel: number of elements in @sids
2342  *
2343  * Generate the set of SIDs for legal security contexts
2344  * for a given user that can be reached by @fromsid.
2345  * Set *@sids to point to a dynamically allocated
2346  * array containing the set of SIDs.  Set *@nel to the
2347  * number of elements in the array.
2348  */
2349
2350 int security_get_user_sids(u32 fromsid,
2351                            char *username,
2352                            u32 **sids,
2353                            u32 *nel)
2354 {
2355         struct context *fromcon, usercon;
2356         u32 *mysids = NULL, *mysids2, sid;
2357         u32 mynel = 0, maxnel = SIDS_NEL;
2358         struct user_datum *user;
2359         struct role_datum *role;
2360         struct ebitmap_node *rnode, *tnode;
2361         int rc = 0, i, j;
2362
2363         *sids = NULL;
2364         *nel = 0;
2365
2366         if (!ss_initialized)
2367                 goto out;
2368
2369         read_lock(&policy_rwlock);
2370
2371         context_init(&usercon);
2372
2373         rc = -EINVAL;
2374         fromcon = sidtab_search(&sidtab, fromsid);
2375         if (!fromcon)
2376                 goto out_unlock;
2377
2378         rc = -EINVAL;
2379         user = hashtab_search(policydb.p_users.table, username);
2380         if (!user)
2381                 goto out_unlock;
2382
2383         usercon.user = user->value;
2384
2385         rc = -ENOMEM;
2386         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2387         if (!mysids)
2388                 goto out_unlock;
2389
2390         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2391                 role = policydb.role_val_to_struct[i];
2392                 usercon.role = i + 1;
2393                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2394                         usercon.type = j + 1;
2395
2396                         if (mls_setup_user_range(fromcon, user, &usercon))
2397                                 continue;
2398
2399                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2400                         if (rc)
2401                                 goto out_unlock;
2402                         if (mynel < maxnel) {
2403                                 mysids[mynel++] = sid;
2404                         } else {
2405                                 rc = -ENOMEM;
2406                                 maxnel += SIDS_NEL;
2407                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2408                                 if (!mysids2)
2409                                         goto out_unlock;
2410                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2411                                 kfree(mysids);
2412                                 mysids = mysids2;
2413                                 mysids[mynel++] = sid;
2414                         }
2415                 }
2416         }
2417         rc = 0;
2418 out_unlock:
2419         read_unlock(&policy_rwlock);
2420         if (rc || !mynel) {
2421                 kfree(mysids);
2422                 goto out;
2423         }
2424
2425         rc = -ENOMEM;
2426         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2427         if (!mysids2) {
2428                 kfree(mysids);
2429                 goto out;
2430         }
2431         for (i = 0, j = 0; i < mynel; i++) {
2432                 struct av_decision dummy_avd;
2433                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2434                                           SECCLASS_PROCESS, /* kernel value */
2435                                           PROCESS__TRANSITION, AVC_STRICT,
2436                                           &dummy_avd);
2437                 if (!rc)
2438                         mysids2[j++] = mysids[i];
2439                 cond_resched();
2440         }
2441         rc = 0;
2442         kfree(mysids);
2443         *sids = mysids2;
2444         *nel = j;
2445 out:
2446         return rc;
2447 }
2448
2449 /**
2450  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2451  * @fstype: filesystem type
2452  * @path: path from root of mount
2453  * @sclass: file security class
2454  * @sid: SID for path
2455  *
2456  * Obtain a SID to use for a file in a filesystem that
2457  * cannot support xattr or use a fixed labeling behavior like
2458  * transition SIDs or task SIDs.
2459  *
2460  * The caller must acquire the policy_rwlock before calling this function.
2461  */
2462 static inline int __security_genfs_sid(const char *fstype,
2463                                        char *path,
2464                                        u16 orig_sclass,
2465                                        u32 *sid)
2466 {
2467         int len;
2468         u16 sclass;
2469         struct genfs *genfs;
2470         struct ocontext *c;
2471         int rc, cmp = 0;
2472
2473         while (path[0] == '/' && path[1] == '/')
2474                 path++;
2475
2476         sclass = unmap_class(orig_sclass);
2477         *sid = SECINITSID_UNLABELED;
2478
2479         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2480                 cmp = strcmp(fstype, genfs->fstype);
2481                 if (cmp <= 0)
2482                         break;
2483         }
2484
2485         rc = -ENOENT;
2486         if (!genfs || cmp)
2487                 goto out;
2488
2489         for (c = genfs->head; c; c = c->next) {
2490                 len = strlen(c->u.name);
2491                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2492                     (strncmp(c->u.name, path, len) == 0))
2493                         break;
2494         }
2495
2496         rc = -ENOENT;
2497         if (!c)
2498                 goto out;
2499
2500         if (!c->sid[0]) {
2501                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2502                 if (rc)
2503                         goto out;
2504         }
2505
2506         *sid = c->sid[0];
2507         rc = 0;
2508 out:
2509         return rc;
2510 }
2511
2512 /**
2513  * security_genfs_sid - Obtain a SID for a file in a filesystem
2514  * @fstype: filesystem type
2515  * @path: path from root of mount
2516  * @sclass: file security class
2517  * @sid: SID for path
2518  *
2519  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2520  * it afterward.
2521  */
2522 int security_genfs_sid(const char *fstype,
2523                        char *path,
2524                        u16 orig_sclass,
2525                        u32 *sid)
2526 {
2527         int retval;
2528
2529         read_lock(&policy_rwlock);
2530         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2531         read_unlock(&policy_rwlock);
2532         return retval;
2533 }
2534
2535 /**
2536  * security_fs_use - Determine how to handle labeling for a filesystem.
2537  * @sb: superblock in question
2538  */
2539 int security_fs_use(struct super_block *sb)
2540 {
2541         int rc = 0;
2542         struct ocontext *c;
2543         struct superblock_security_struct *sbsec = sb->s_security;
2544         const char *fstype = sb->s_type->name;
2545
2546         read_lock(&policy_rwlock);
2547
2548         c = policydb.ocontexts[OCON_FSUSE];
2549         while (c) {
2550                 if (strcmp(fstype, c->u.name) == 0)
2551                         break;
2552                 c = c->next;
2553         }
2554
2555         if (c) {
2556                 sbsec->behavior = c->v.behavior;
2557                 if (!c->sid[0]) {
2558                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2559                                                    &c->sid[0]);
2560                         if (rc)
2561                                 goto out;
2562                 }
2563                 sbsec->sid = c->sid[0];
2564         } else {
2565                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2566                                           &sbsec->sid);
2567                 if (rc) {
2568                         sbsec->behavior = SECURITY_FS_USE_NONE;
2569                         rc = 0;
2570                 } else {
2571                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2572                 }
2573         }
2574
2575 out:
2576         read_unlock(&policy_rwlock);
2577         return rc;
2578 }
2579
2580 int security_get_bools(int *len, char ***names, int **values)
2581 {
2582         int i, rc;
2583
2584         read_lock(&policy_rwlock);
2585         *names = NULL;
2586         *values = NULL;
2587
2588         rc = 0;
2589         *len = policydb.p_bools.nprim;
2590         if (!*len)
2591                 goto out;
2592
2593         rc = -ENOMEM;
2594         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2595         if (!*names)
2596                 goto err;
2597
2598         rc = -ENOMEM;
2599         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2600         if (!*values)
2601                 goto err;
2602
2603         for (i = 0; i < *len; i++) {
2604                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2605
2606                 rc = -ENOMEM;
2607                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2608                 if (!(*names)[i])
2609                         goto err;
2610         }
2611         rc = 0;
2612 out:
2613         read_unlock(&policy_rwlock);
2614         return rc;
2615 err:
2616         if (*names) {
2617                 for (i = 0; i < *len; i++)
2618                         kfree((*names)[i]);
2619                 kfree(*names);
2620         }
2621         kfree(*values);
2622         *len = 0;
2623         *names = NULL;
2624         *values = NULL;
2625         goto out;
2626 }
2627
2628
2629 int security_set_bools(int len, int *values)
2630 {
2631         int i, rc;
2632         int lenp, seqno = 0;
2633         struct cond_node *cur;
2634
2635         write_lock_irq(&policy_rwlock);
2636
2637         rc = -EFAULT;
2638         lenp = policydb.p_bools.nprim;
2639         if (len != lenp)
2640                 goto out;
2641
2642         for (i = 0; i < len; i++) {
2643                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2644                         audit_log(current->audit_context, GFP_ATOMIC,
2645                                 AUDIT_MAC_CONFIG_CHANGE,
2646                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2647                                 sym_name(&policydb, SYM_BOOLS, i),
2648                                 !!values[i],
2649                                 policydb.bool_val_to_struct[i]->state,
2650                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2651                                 audit_get_sessionid(current));
2652                 }
2653                 if (values[i])
2654                         policydb.bool_val_to_struct[i]->state = 1;
2655                 else
2656                         policydb.bool_val_to_struct[i]->state = 0;
2657         }
2658
2659         for (cur = policydb.cond_list; cur; cur = cur->next) {
2660                 rc = evaluate_cond_node(&policydb, cur);
2661                 if (rc)
2662                         goto out;
2663         }
2664
2665         seqno = ++latest_granting;
2666         rc = 0;
2667 out:
2668         write_unlock_irq(&policy_rwlock);
2669         if (!rc) {
2670                 avc_ss_reset(seqno);
2671                 selnl_notify_policyload(seqno);
2672                 selinux_status_update_policyload(seqno);
2673                 selinux_xfrm_notify_policyload();
2674         }
2675         return rc;
2676 }
2677
2678 int security_get_bool_value(int index)
2679 {
2680         int rc;
2681         int len;
2682
2683         read_lock(&policy_rwlock);
2684
2685         rc = -EFAULT;
2686         len = policydb.p_bools.nprim;
2687         if (index >= len)
2688                 goto out;
2689
2690         rc = policydb.bool_val_to_struct[index]->state;
2691 out:
2692         read_unlock(&policy_rwlock);
2693         return rc;
2694 }
2695
2696 static int security_preserve_bools(struct policydb *p)
2697 {
2698         int rc, nbools = 0, *bvalues = NULL, i;
2699         char **bnames = NULL;
2700         struct cond_bool_datum *booldatum;
2701         struct cond_node *cur;
2702
2703         rc = security_get_bools(&nbools, &bnames, &bvalues);
2704         if (rc)
2705                 goto out;
2706         for (i = 0; i < nbools; i++) {
2707                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2708                 if (booldatum)
2709                         booldatum->state = bvalues[i];
2710         }
2711         for (cur = p->cond_list; cur; cur = cur->next) {
2712                 rc = evaluate_cond_node(p, cur);
2713                 if (rc)
2714                         goto out;
2715         }
2716
2717 out:
2718         if (bnames) {
2719                 for (i = 0; i < nbools; i++)
2720                         kfree(bnames[i]);
2721         }
2722         kfree(bnames);
2723         kfree(bvalues);
2724         return rc;
2725 }
2726
2727 /*
2728  * security_sid_mls_copy() - computes a new sid based on the given
2729  * sid and the mls portion of mls_sid.
2730  */
2731 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2732 {
2733         struct context *context1;
2734         struct context *context2;
2735         struct context newcon;
2736         char *s;
2737         u32 len;
2738         int rc;
2739
2740         rc = 0;
2741         if (!ss_initialized || !policydb.mls_enabled) {
2742                 *new_sid = sid;
2743                 goto out;
2744         }
2745
2746         context_init(&newcon);
2747
2748         read_lock(&policy_rwlock);
2749
2750         rc = -EINVAL;
2751         context1 = sidtab_search(&sidtab, sid);
2752         if (!context1) {
2753                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2754                         __func__, sid);
2755                 goto out_unlock;
2756         }
2757
2758         rc = -EINVAL;
2759         context2 = sidtab_search(&sidtab, mls_sid);
2760         if (!context2) {
2761                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2762                         __func__, mls_sid);
2763                 goto out_unlock;
2764         }
2765
2766         newcon.user = context1->user;
2767         newcon.role = context1->role;
2768         newcon.type = context1->type;
2769         rc = mls_context_cpy(&newcon, context2);
2770         if (rc)
2771                 goto out_unlock;
2772
2773         /* Check the validity of the new context. */
2774         if (!policydb_context_isvalid(&policydb, &newcon)) {
2775                 rc = convert_context_handle_invalid_context(&newcon);
2776                 if (rc) {
2777                         if (!context_struct_to_string(&newcon, &s, &len)) {
2778                                 audit_log(current->audit_context,
2779                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2780                                           "op=security_sid_mls_copy "
2781                                           "invalid_context=%s", s);
2782                                 kfree(s);
2783                         }
2784                         goto out_unlock;
2785                 }
2786         }
2787
2788         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2789 out_unlock:
2790         read_unlock(&policy_rwlock);
2791         context_destroy(&newcon);
2792 out:
2793         return rc;
2794 }
2795
2796 /**
2797  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2798  * @nlbl_sid: NetLabel SID
2799  * @nlbl_type: NetLabel labeling protocol type
2800  * @xfrm_sid: XFRM SID
2801  *
2802  * Description:
2803  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2804  * resolved into a single SID it is returned via @peer_sid and the function
2805  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2806  * returns a negative value.  A table summarizing the behavior is below:
2807  *
2808  *                                 | function return |      @sid
2809  *   ------------------------------+-----------------+-----------------
2810  *   no peer labels                |        0        |    SECSID_NULL
2811  *   single peer label             |        0        |    <peer_label>
2812  *   multiple, consistent labels   |        0        |    <peer_label>
2813  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2814  *
2815  */
2816 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2817                                  u32 xfrm_sid,
2818                                  u32 *peer_sid)
2819 {
2820         int rc;
2821         struct context *nlbl_ctx;
2822         struct context *xfrm_ctx;
2823
2824         *peer_sid = SECSID_NULL;
2825
2826         /* handle the common (which also happens to be the set of easy) cases
2827          * right away, these two if statements catch everything involving a
2828          * single or absent peer SID/label */
2829         if (xfrm_sid == SECSID_NULL) {
2830                 *peer_sid = nlbl_sid;
2831                 return 0;
2832         }
2833         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2834          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2835          * is present */
2836         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2837                 *peer_sid = xfrm_sid;
2838                 return 0;
2839         }
2840
2841         /* we don't need to check ss_initialized here since the only way both
2842          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2843          * security server was initialized and ss_initialized was true */
2844         if (!policydb.mls_enabled)
2845                 return 0;
2846
2847         read_lock(&policy_rwlock);
2848
2849         rc = -EINVAL;
2850         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2851         if (!nlbl_ctx) {
2852                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2853                        __func__, nlbl_sid);
2854                 goto out;
2855         }
2856         rc = -EINVAL;
2857         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2858         if (!xfrm_ctx) {
2859                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2860                        __func__, xfrm_sid);
2861                 goto out;
2862         }
2863         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2864         if (rc)
2865                 goto out;
2866
2867         /* at present NetLabel SIDs/labels really only carry MLS
2868          * information so if the MLS portion of the NetLabel SID
2869          * matches the MLS portion of the labeled XFRM SID/label
2870          * then pass along the XFRM SID as it is the most
2871          * expressive */
2872         *peer_sid = xfrm_sid;
2873 out:
2874         read_unlock(&policy_rwlock);
2875         return rc;
2876 }
2877
2878 static int get_classes_callback(void *k, void *d, void *args)
2879 {
2880         struct class_datum *datum = d;
2881         char *name = k, **classes = args;
2882         int value = datum->value - 1;
2883
2884         classes[value] = kstrdup(name, GFP_ATOMIC);
2885         if (!classes[value])
2886                 return -ENOMEM;
2887
2888         return 0;
2889 }
2890
2891 int security_get_classes(char ***classes, int *nclasses)
2892 {
2893         int rc;
2894
2895         read_lock(&policy_rwlock);
2896
2897         rc = -ENOMEM;
2898         *nclasses = policydb.p_classes.nprim;
2899         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2900         if (!*classes)
2901                 goto out;
2902
2903         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2904                         *classes);
2905         if (rc) {
2906                 int i;
2907                 for (i = 0; i < *nclasses; i++)
2908                         kfree((*classes)[i]);
2909                 kfree(*classes);
2910         }
2911
2912 out:
2913         read_unlock(&policy_rwlock);
2914         return rc;
2915 }
2916
2917 static int get_permissions_callback(void *k, void *d, void *args)
2918 {
2919         struct perm_datum *datum = d;
2920         char *name = k, **perms = args;
2921         int value = datum->value - 1;
2922
2923         perms[value] = kstrdup(name, GFP_ATOMIC);
2924         if (!perms[value])
2925                 return -ENOMEM;
2926
2927         return 0;
2928 }
2929
2930 int security_get_permissions(char *class, char ***perms, int *nperms)
2931 {
2932         int rc, i;
2933         struct class_datum *match;
2934
2935         read_lock(&policy_rwlock);
2936
2937         rc = -EINVAL;
2938         match = hashtab_search(policydb.p_classes.table, class);
2939         if (!match) {
2940                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2941                         __func__, class);
2942                 goto out;
2943         }
2944
2945         rc = -ENOMEM;
2946         *nperms = match->permissions.nprim;
2947         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2948         if (!*perms)
2949                 goto out;
2950
2951         if (match->comdatum) {
2952                 rc = hashtab_map(match->comdatum->permissions.table,
2953                                 get_permissions_callback, *perms);
2954                 if (rc)
2955                         goto err;
2956         }
2957
2958         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2959                         *perms);
2960         if (rc)
2961                 goto err;
2962
2963 out:
2964         read_unlock(&policy_rwlock);
2965         return rc;
2966
2967 err:
2968         read_unlock(&policy_rwlock);
2969         for (i = 0; i < *nperms; i++)
2970                 kfree((*perms)[i]);
2971         kfree(*perms);
2972         return rc;
2973 }
2974
2975 int security_get_reject_unknown(void)
2976 {
2977         return policydb.reject_unknown;
2978 }
2979
2980 int security_get_allow_unknown(void)
2981 {
2982         return policydb.allow_unknown;
2983 }
2984
2985 /**
2986  * security_policycap_supported - Check for a specific policy capability
2987  * @req_cap: capability
2988  *
2989  * Description:
2990  * This function queries the currently loaded policy to see if it supports the
2991  * capability specified by @req_cap.  Returns true (1) if the capability is
2992  * supported, false (0) if it isn't supported.
2993  *
2994  */
2995 int security_policycap_supported(unsigned int req_cap)
2996 {
2997         int rc;
2998
2999         read_lock(&policy_rwlock);
3000         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3001         read_unlock(&policy_rwlock);
3002
3003         return rc;
3004 }
3005
3006 struct selinux_audit_rule {
3007         u32 au_seqno;
3008         struct context au_ctxt;
3009 };
3010
3011 void selinux_audit_rule_free(void *vrule)
3012 {
3013         struct selinux_audit_rule *rule = vrule;
3014
3015         if (rule) {
3016                 context_destroy(&rule->au_ctxt);
3017                 kfree(rule);
3018         }
3019 }
3020
3021 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3022 {
3023         struct selinux_audit_rule *tmprule;
3024         struct role_datum *roledatum;
3025         struct type_datum *typedatum;
3026         struct user_datum *userdatum;
3027         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3028         int rc = 0;
3029
3030         *rule = NULL;
3031
3032         if (!ss_initialized)
3033                 return -EOPNOTSUPP;
3034
3035         switch (field) {
3036         case AUDIT_SUBJ_USER:
3037         case AUDIT_SUBJ_ROLE:
3038         case AUDIT_SUBJ_TYPE:
3039         case AUDIT_OBJ_USER:
3040         case AUDIT_OBJ_ROLE:
3041         case AUDIT_OBJ_TYPE:
3042                 /* only 'equals' and 'not equals' fit user, role, and type */
3043                 if (op != Audit_equal && op != Audit_not_equal)
3044                         return -EINVAL;
3045                 break;
3046         case AUDIT_SUBJ_SEN:
3047         case AUDIT_SUBJ_CLR:
3048         case AUDIT_OBJ_LEV_LOW:
3049         case AUDIT_OBJ_LEV_HIGH:
3050                 /* we do not allow a range, indicated by the presence of '-' */
3051                 if (strchr(rulestr, '-'))
3052                         return -EINVAL;
3053                 break;
3054         default:
3055                 /* only the above fields are valid */
3056                 return -EINVAL;
3057         }
3058
3059         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3060         if (!tmprule)
3061                 return -ENOMEM;
3062
3063         context_init(&tmprule->au_ctxt);
3064
3065         read_lock(&policy_rwlock);
3066
3067         tmprule->au_seqno = latest_granting;
3068
3069         switch (field) {
3070         case AUDIT_SUBJ_USER:
3071         case AUDIT_OBJ_USER:
3072                 rc = -EINVAL;
3073                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3074                 if (!userdatum)
3075                         goto out;
3076                 tmprule->au_ctxt.user = userdatum->value;
3077                 break;
3078         case AUDIT_SUBJ_ROLE:
3079         case AUDIT_OBJ_ROLE:
3080                 rc = -EINVAL;
3081                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3082                 if (!roledatum)
3083                         goto out;
3084                 tmprule->au_ctxt.role = roledatum->value;
3085                 break;
3086         case AUDIT_SUBJ_TYPE:
3087         case AUDIT_OBJ_TYPE:
3088                 rc = -EINVAL;
3089                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3090                 if (!typedatum)
3091                         goto out;
3092                 tmprule->au_ctxt.type = typedatum->value;
3093                 break;
3094         case AUDIT_SUBJ_SEN:
3095         case AUDIT_SUBJ_CLR:
3096         case AUDIT_OBJ_LEV_LOW:
3097         case AUDIT_OBJ_LEV_HIGH:
3098                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3099                 if (rc)
3100                         goto out;
3101                 break;
3102         }
3103         rc = 0;
3104 out:
3105         read_unlock(&policy_rwlock);
3106
3107         if (rc) {
3108                 selinux_audit_rule_free(tmprule);
3109                 tmprule = NULL;
3110         }
3111
3112         *rule = tmprule;
3113
3114         return rc;
3115 }
3116
3117 /* Check to see if the rule contains any selinux fields */
3118 int selinux_audit_rule_known(struct audit_krule *rule)
3119 {
3120         int i;
3121
3122         for (i = 0; i < rule->field_count; i++) {
3123                 struct audit_field *f = &rule->fields[i];
3124                 switch (f->type) {
3125                 case AUDIT_SUBJ_USER:
3126                 case AUDIT_SUBJ_ROLE:
3127                 case AUDIT_SUBJ_TYPE:
3128                 case AUDIT_SUBJ_SEN:
3129                 case AUDIT_SUBJ_CLR:
3130                 case AUDIT_OBJ_USER:
3131                 case AUDIT_OBJ_ROLE:
3132                 case AUDIT_OBJ_TYPE:
3133                 case AUDIT_OBJ_LEV_LOW:
3134                 case AUDIT_OBJ_LEV_HIGH:
3135                         return 1;
3136                 }
3137         }
3138
3139         return 0;
3140 }
3141
3142 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3143                              struct audit_context *actx)
3144 {
3145         struct context *ctxt;
3146         struct mls_level *level;
3147         struct selinux_audit_rule *rule = vrule;
3148         int match = 0;
3149
3150         if (unlikely(!rule)) {
3151                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3152                 return -ENOENT;
3153         }
3154
3155         read_lock(&policy_rwlock);
3156
3157         if (rule->au_seqno < latest_granting) {
3158                 match = -ESTALE;
3159                 goto out;
3160         }
3161
3162         ctxt = sidtab_search(&sidtab, sid);
3163         if (unlikely(!ctxt)) {
3164                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3165                           sid);
3166                 match = -ENOENT;
3167                 goto out;
3168         }
3169
3170         /* a field/op pair that is not caught here will simply fall through
3171            without a match */
3172         switch (field) {
3173         case AUDIT_SUBJ_USER:
3174         case AUDIT_OBJ_USER:
3175                 switch (op) {
3176                 case Audit_equal:
3177                         match = (ctxt->user == rule->au_ctxt.user);
3178                         break;
3179                 case Audit_not_equal:
3180                         match = (ctxt->user != rule->au_ctxt.user);
3181                         break;
3182                 }
3183                 break;
3184         case AUDIT_SUBJ_ROLE:
3185         case AUDIT_OBJ_ROLE:
3186                 switch (op) {
3187                 case Audit_equal:
3188                         match = (ctxt->role == rule->au_ctxt.role);
3189                         break;
3190                 case Audit_not_equal:
3191                         match = (ctxt->role != rule->au_ctxt.role);
3192                         break;
3193                 }
3194                 break;
3195         case AUDIT_SUBJ_TYPE:
3196         case AUDIT_OBJ_TYPE:
3197                 switch (op) {
3198                 case Audit_equal:
3199                         match = (ctxt->type == rule->au_ctxt.type);
3200                         break;
3201                 case Audit_not_equal:
3202                         match = (ctxt->type != rule->au_ctxt.type);
3203                         break;
3204                 }
3205                 break;
3206         case AUDIT_SUBJ_SEN:
3207         case AUDIT_SUBJ_CLR:
3208         case AUDIT_OBJ_LEV_LOW:
3209         case AUDIT_OBJ_LEV_HIGH:
3210                 level = ((field == AUDIT_SUBJ_SEN ||
3211                           field == AUDIT_OBJ_LEV_LOW) ?
3212                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3213                 switch (op) {
3214                 case Audit_equal:
3215                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3216                                              level);
3217                         break;
3218                 case Audit_not_equal:
3219                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3220                                               level);
3221                         break;
3222                 case Audit_lt:
3223                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3224                                                level) &&
3225                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3226                                                level));
3227                         break;
3228                 case Audit_le:
3229                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3230                                               level);
3231                         break;
3232                 case Audit_gt:
3233                         match = (mls_level_dom(level,
3234                                               &rule->au_ctxt.range.level[0]) &&
3235                                  !mls_level_eq(level,
3236                                                &rule->au_ctxt.range.level[0]));
3237                         break;
3238                 case Audit_ge:
3239                         match = mls_level_dom(level,
3240                                               &rule->au_ctxt.range.level[0]);
3241                         break;
3242                 }
3243         }
3244
3245 out:
3246         read_unlock(&policy_rwlock);
3247         return match;
3248 }
3249
3250 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3251
3252 static int aurule_avc_callback(u32 event)
3253 {
3254         int err = 0;
3255
3256         if (event == AVC_CALLBACK_RESET && aurule_callback)
3257                 err = aurule_callback();
3258         return err;
3259 }
3260
3261 static int __init aurule_init(void)
3262 {
3263         int err;
3264
3265         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3266         if (err)
3267                 panic("avc_add_callback() failed, error %d\n", err);
3268
3269         return err;
3270 }
3271 __initcall(aurule_init);
3272
3273 #ifdef CONFIG_NETLABEL
3274 /**
3275  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3276  * @secattr: the NetLabel packet security attributes
3277  * @sid: the SELinux SID
3278  *
3279  * Description:
3280  * Attempt to cache the context in @ctx, which was derived from the packet in
3281  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3282  * already been initialized.
3283  *
3284  */
3285 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3286                                       u32 sid)
3287 {
3288         u32 *sid_cache;
3289
3290         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3291         if (sid_cache == NULL)
3292                 return;
3293         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3294         if (secattr->cache == NULL) {
3295                 kfree(sid_cache);
3296                 return;
3297         }
3298
3299         *sid_cache = sid;
3300         secattr->cache->free = kfree;
3301         secattr->cache->data = sid_cache;
3302         secattr->flags |= NETLBL_SECATTR_CACHE;
3303 }
3304
3305 /**
3306  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3307  * @secattr: the NetLabel packet security attributes
3308  * @sid: the SELinux SID
3309  *
3310  * Description:
3311  * Convert the given NetLabel security attributes in @secattr into a
3312  * SELinux SID.  If the @secattr field does not contain a full SELinux
3313  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3314  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3315  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3316  * conversion for future lookups.  Returns zero on success, negative values on
3317  * failure.
3318  *
3319  */
3320 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3321                                    u32 *sid)
3322 {
3323         int rc;
3324         struct context *ctx;
3325         struct context ctx_new;
3326
3327         if (!ss_initialized) {
3328                 *sid = SECSID_NULL;
3329                 return 0;
3330         }
3331
3332         read_lock(&policy_rwlock);
3333
3334         if (secattr->flags & NETLBL_SECATTR_CACHE)
3335                 *sid = *(u32 *)secattr->cache->data;
3336         else if (secattr->flags & NETLBL_SECATTR_SECID)
3337                 *sid = secattr->attr.secid;
3338         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3339                 rc = -EIDRM;
3340                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3341                 if (ctx == NULL)
3342                         goto out;
3343
3344                 context_init(&ctx_new);
3345                 ctx_new.user = ctx->user;
3346                 ctx_new.role = ctx->role;
3347                 ctx_new.type = ctx->type;
3348                 mls_import_netlbl_lvl(&ctx_new, secattr);
3349                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3350                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3351                         if (rc)
3352                                 goto out;
3353                 }
3354                 rc = -EIDRM;
3355                 if (!mls_context_isvalid(&policydb, &ctx_new))
3356                         goto out_free;
3357
3358                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3359                 if (rc)
3360                         goto out_free;
3361
3362                 security_netlbl_cache_add(secattr, *sid);
3363
3364                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3365         } else
3366                 *sid = SECSID_NULL;
3367
3368         read_unlock(&policy_rwlock);
3369         return 0;
3370 out_free:
3371         ebitmap_destroy(&ctx_new.range.level[0].cat);
3372 out:
3373         read_unlock(&policy_rwlock);
3374         return rc;
3375 }
3376
3377 /**
3378  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3379  * @sid: the SELinux SID
3380  * @secattr: the NetLabel packet security attributes
3381  *
3382  * Description:
3383  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3384  * Returns zero on success, negative values on failure.
3385  *
3386  */
3387 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3388 {
3389         int rc;
3390         struct context *ctx;
3391
3392         if (!ss_initialized)
3393                 return 0;
3394
3395         read_lock(&policy_rwlock);
3396
3397         rc = -ENOENT;
3398         ctx = sidtab_search(&sidtab, sid);
3399         if (ctx == NULL)
3400                 goto out;
3401
3402         rc = -ENOMEM;
3403         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3404                                   GFP_ATOMIC);
3405         if (secattr->domain == NULL)
3406                 goto out;
3407
3408         secattr->attr.secid = sid;
3409         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3410         mls_export_netlbl_lvl(ctx, secattr);
3411         rc = mls_export_netlbl_cat(ctx, secattr);
3412 out:
3413         read_unlock(&policy_rwlock);
3414         return rc;
3415 }
3416 #endif /* CONFIG_NETLABEL */
3417
3418 /**
3419  * security_read_policy - read the policy.
3420  * @data: binary policy data
3421  * @len: length of data in bytes
3422  *
3423  */
3424 int security_read_policy(void **data, size_t *len)
3425 {
3426         int rc;
3427         struct policy_file fp;
3428
3429         if (!ss_initialized)
3430                 return -EINVAL;
3431
3432         *len = security_policydb_len();
3433
3434         *data = vmalloc_user(*len);
3435         if (!*data)
3436                 return -ENOMEM;
3437
3438         fp.data = *data;
3439         fp.len = *len;
3440
3441         read_lock(&policy_rwlock);
3442         rc = policydb_write(&policydb, &fp);
3443         read_unlock(&policy_rwlock);
3444
3445         if (rc)
3446                 return rc;
3447
3448         *len = (unsigned long)fp.data - (unsigned long)*data;
3449         return 0;
3450
3451 }