security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <[email protected]>
   5  *           James Morris <[email protected]>
   6  *
   7  * Updated: Trusted Computer Solutions, Inc. <[email protected]>
   8  *
   9  *      Support for enhanced MLS infrastructure.
  10  *      Support for context based audit filters.
  11  *
  12  * Updated: Frank Mayer <[email protected]> and Karl MacMillan <[email protected]>
  13  *
  14  *      Added conditional policy language extensions
  15  *
  16  * Updated: Hewlett-Packard <[email protected]>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <[email protected]>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Updated: KaiGai Kohei <[email protected]>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <[email protected]>
  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 <[email protected]>
  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_extsockclass;
  76 int selinux_policycap_alwaysnetwork;
  77 int selinux_policycap_cgroupseclabel;
  78
  79 static DEFINE_RWLOCK(policy_rwlock);
  80
  81 static struct sidtab sidtab;
  82 struct policydb policydb;
  83 int ss_initialized;
  84
  85 /*
  86  * The largest sequence number that has been used when
  87  * providing an access decision to the access vector cache.
  88  * The sequence number only changes when a policy change
  89  * occurs.
  90  */
  91 static u32 latest_granting;
  92
  93 /* Forward declaration. */
  94 static int context_struct_to_string(struct context *context, char **scontext,
  95                                     u32 *scontext_len);
  96
  97 static void context_struct_compute_av(struct context *scontext,
  98                                         struct context *tcontext,
  99                                         u16 tclass,
 100                                         struct av_decision *avd,
 101                                         struct extended_perms *xperms);
 102
 103 struct selinux_mapping {
 104         u16 value; /* policy value */
 105         unsigned num_perms;
 106         u32 perms[sizeof(u32) * 8];
 107 };
 108
 109 static struct selinux_mapping *current_mapping;
 110 static u16 current_mapping_size;
 111
 112 static int selinux_set_mapping(struct policydb *pol,
 113                                struct security_class_mapping *map,
 114                                struct selinux_mapping **out_map_p,
 115                                u16 *out_map_size)
 116 {
 117         struct selinux_mapping *out_map = NULL;
 118         size_t size = sizeof(struct selinux_mapping);
 119         u16 i, j;
 120         unsigned k;
 121         bool print_unknown_handle = false;
 122
 123         /* Find number of classes in the input mapping */
 124         if (!map)
 125                 return -EINVAL;
 126         i = 0;
 127         while (map[i].name)
 128                 i++;
 129
 130         /* Allocate space for the class records, plus one for class zero */
 131         out_map = kcalloc(++i, size, GFP_ATOMIC);
 132         if (!out_map)
 133                 return -ENOMEM;
 134
 135         /* Store the raw class and permission values */
 136         j = 0;
 137         while (map[j].name) {
 138                 struct security_class_mapping *p_in = map + (j++);
 139                 struct selinux_mapping *p_out = out_map + j;
 140
 141                 /* An empty class string skips ahead */
 142                 if (!strcmp(p_in->name, "")) {
 143                         p_out->num_perms = 0;
 144                         continue;
 145                 }
 146
 147                 p_out->value = string_to_security_class(pol, p_in->name);
 148                 if (!p_out->value) {
 149                         printk(KERN_INFO
 150                                "SELinux:  Class %s not defined in policy.\n",
 151                                p_in->name);
 152                         if (pol->reject_unknown)
 153                                 goto err;
 154                         p_out->num_perms = 0;
 155                         print_unknown_handle = true;
 156                         continue;
 157                 }
 158
 159                 k = 0;
 160                 while (p_in->perms && p_in->perms[k]) {
 161                         /* An empty permission string skips ahead */
 162                         if (!*p_in->perms[k]) {
 163                                 k++;
 164                                 continue;
 165                         }
 166                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 167                                                             p_in->perms[k]);
 168                         if (!p_out->perms[k]) {
 169                                 printk(KERN_INFO
 170                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 171                                        p_in->perms[k], p_in->name);
 172                                 if (pol->reject_unknown)
 173                                         goto err;
 174                                 print_unknown_handle = true;
 175                         }
 176
 177                         k++;
 178                 }
 179                 p_out->num_perms = k;
 180         }
 181
 182         if (print_unknown_handle)
 183                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 184                        pol->allow_unknown ? "allowed" : "denied");
 185
 186         *out_map_p = out_map;
 187         *out_map_size = i;
 188         return 0;
 189 err:
 190         kfree(out_map);
 191         return -EINVAL;
 192 }
 193
 194 /*
 195  * Get real, policy values from mapped values
 196  */
 197
 198 static u16 unmap_class(u16 tclass)
 199 {
 200         if (tclass < current_mapping_size)
 201                 return current_mapping[tclass].value;
 202
 203         return tclass;
 204 }
 205
 206 /*
 207  * Get kernel value for class from its policy value
 208  */
 209 static u16 map_class(u16 pol_value)
 210 {
 211         u16 i;
 212
 213         for (i = 1; i < current_mapping_size; i++) {
 214                 if (current_mapping[i].value == pol_value)
 215                         return i;
 216         }
 217
 218         return SECCLASS_NULL;
 219 }
 220
 221 static void map_decision(u16 tclass, struct av_decision *avd,
 222                          int allow_unknown)
 223 {
 224         if (tclass < current_mapping_size) {
 225                 unsigned i, n = current_mapping[tclass].num_perms;
 226                 u32 result;
 227
 228                 for (i = 0, result = 0; i < n; i++) {
 229                         if (avd->allowed & current_mapping[tclass].perms[i])
 230                                 result |= 1<<i;
 231                         if (allow_unknown && !current_mapping[tclass].perms[i])
 232                                 result |= 1<<i;
 233                 }
 234                 avd->allowed = result;
 235
 236                 for (i = 0, result = 0; i < n; i++)
 237                         if (avd->auditallow & current_mapping[tclass].perms[i])
 238                                 result |= 1<<i;
 239                 avd->auditallow = result;
 240
 241                 for (i = 0, result = 0; i < n; i++) {
 242                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 243                                 result |= 1<<i;
 244                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 245                                 result |= 1<<i;
 246                 }
 247                 /*
 248                  * In case the kernel has a bug and requests a permission
 249                  * between num_perms and the maximum permission number, we
 250                  * should audit that denial
 251                  */
 252                 for (; i < (sizeof(u32)*8); i++)
 253                         result |= 1<<i;
 254                 avd->auditdeny = result;
 255         }
 256 }
 257
 258 int security_mls_enabled(void)
 259 {
 260         return policydb.mls_enabled;
 261 }
 262
 263 /*
 264  * Return the boolean value of a constraint expression
 265  * when it is applied to the specified source and target
 266  * security contexts.
 267  *
 268  * xcontext is a special beast...  It is used by the validatetrans rules
 269  * only.  For these rules, scontext is the context before the transition,
 270  * tcontext is the context after the transition, and xcontext is the context
 271  * of the process performing the transition.  All other callers of
 272  * constraint_expr_eval should pass in NULL for xcontext.
 273  */
 274 static int constraint_expr_eval(struct context *scontext,
 275                                 struct context *tcontext,
 276                                 struct context *xcontext,
 277                                 struct constraint_expr *cexpr)
 278 {
 279         u32 val1, val2;
 280         struct context *c;
 281         struct role_datum *r1, *r2;
 282         struct mls_level *l1, *l2;
 283         struct constraint_expr *e;
 284         int s[CEXPR_MAXDEPTH];
 285         int sp = -1;
 286
 287         for (e = cexpr; e; e = e->next) {
 288                 switch (e->expr_type) {
 289                 case CEXPR_NOT:
 290                         BUG_ON(sp < 0);
 291                         s[sp] = !s[sp];
 292                         break;
 293                 case CEXPR_AND:
 294                         BUG_ON(sp < 1);
 295                         sp--;
 296                         s[sp] &= s[sp + 1];
 297                         break;
 298                 case CEXPR_OR:
 299                         BUG_ON(sp < 1);
 300                         sp--;
 301                         s[sp] |= s[sp + 1];
 302                         break;
 303                 case CEXPR_ATTR:
 304                         if (sp == (CEXPR_MAXDEPTH - 1))
 305                                 return 0;
 306                         switch (e->attr) {
 307                         case CEXPR_USER:
 308                                 val1 = scontext->user;
 309                                 val2 = tcontext->user;
 310                                 break;
 311                         case CEXPR_TYPE:
 312                                 val1 = scontext->type;
 313                                 val2 = tcontext->type;
 314                                 break;
 315                         case CEXPR_ROLE:
 316                                 val1 = scontext->role;
 317                                 val2 = tcontext->role;
 318                                 r1 = policydb.role_val_to_struct[val1 - 1];
 319                                 r2 = policydb.role_val_to_struct[val2 - 1];
 320                                 switch (e->op) {
 321                                 case CEXPR_DOM:
 322                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 323                                                                   val2 - 1);
 324                                         continue;
 325                                 case CEXPR_DOMBY:
 326                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 327                                                                   val1 - 1);
 328                                         continue;
 329                                 case CEXPR_INCOMP:
 330                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 331                                                                     val2 - 1) &&
 332                                                    !ebitmap_get_bit(&r2->dominates,
 333                                                                     val1 - 1));
 334                                         continue;
 335                                 default:
 336                                         break;
 337                                 }
 338                                 break;
 339                         case CEXPR_L1L2:
 340                                 l1 = &(scontext->range.level[0]);
 341                                 l2 = &(tcontext->range.level[0]);
 342                                 goto mls_ops;
 343                         case CEXPR_L1H2:
 344                                 l1 = &(scontext->range.level[0]);
 345                                 l2 = &(tcontext->range.level[1]);
 346                                 goto mls_ops;
 347                         case CEXPR_H1L2:
 348                                 l1 = &(scontext->range.level[1]);
 349                                 l2 = &(tcontext->range.level[0]);
 350                                 goto mls_ops;
 351                         case CEXPR_H1H2:
 352                                 l1 = &(scontext->range.level[1]);
 353                                 l2 = &(tcontext->range.level[1]);
 354                                 goto mls_ops;
 355                         case CEXPR_L1H1:
 356                                 l1 = &(scontext->range.level[0]);
 357                                 l2 = &(scontext->range.level[1]);
 358                                 goto mls_ops;
 359                         case CEXPR_L2H2:
 360                                 l1 = &(tcontext->range.level[0]);
 361                                 l2 = &(tcontext->range.level[1]);
 362                                 goto mls_ops;
 363 mls_ops:
 364                         switch (e->op) {
 365                         case CEXPR_EQ:
 366                                 s[++sp] = mls_level_eq(l1, l2);
 367                                 continue;
 368                         case CEXPR_NEQ:
 369                                 s[++sp] = !mls_level_eq(l1, l2);
 370                                 continue;
 371                         case CEXPR_DOM:
 372                                 s[++sp] = mls_level_dom(l1, l2);
 373                                 continue;
 374                         case CEXPR_DOMBY:
 375                                 s[++sp] = mls_level_dom(l2, l1);
 376                                 continue;
 377                         case CEXPR_INCOMP:
 378                                 s[++sp] = mls_level_incomp(l2, l1);
 379                                 continue;
 380                         default:
 381                                 BUG();
 382                                 return 0;
 383                         }
 384                         break;
 385                         default:
 386                                 BUG();
 387                                 return 0;
 388                         }
 389
 390                         switch (e->op) {
 391                         case CEXPR_EQ:
 392                                 s[++sp] = (val1 == val2);
 393                                 break;
 394                         case CEXPR_NEQ:
 395                                 s[++sp] = (val1 != val2);
 396                                 break;
 397                         default:
 398                                 BUG();
 399                                 return 0;
 400                         }
 401                         break;
 402                 case CEXPR_NAMES:
 403                         if (sp == (CEXPR_MAXDEPTH-1))
 404                                 return 0;
 405                         c = scontext;
 406                         if (e->attr & CEXPR_TARGET)
 407                                 c = tcontext;
 408                         else if (e->attr & CEXPR_XTARGET) {
 409                                 c = xcontext;
 410                                 if (!c) {
 411                                         BUG();
 412                                         return 0;
 413                                 }
 414                         }
 415                         if (e->attr & CEXPR_USER)
 416                                 val1 = c->user;
 417                         else if (e->attr & CEXPR_ROLE)
 418                                 val1 = c->role;
 419                         else if (e->attr & CEXPR_TYPE)
 420                                 val1 = c->type;
 421                         else {
 422                                 BUG();
 423                                 return 0;
 424                         }
 425
 426                         switch (e->op) {
 427                         case CEXPR_EQ:
 428                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         case CEXPR_NEQ:
 431                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 432                                 break;
 433                         default:
 434                                 BUG();
 435                                 return 0;
 436                         }
 437                         break;
 438                 default:
 439                         BUG();
 440                         return 0;
 441                 }
 442         }
 443
 444         BUG_ON(sp != 0);
 445         return s[0];
 446 }
 447
 448 /*
 449  * security_dump_masked_av - dumps masked permissions during
 450  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 451  */
 452 static int dump_masked_av_helper(void *k, void *d, void *args)
 453 {
 454         struct perm_datum *pdatum = d;
 455         char **permission_names = args;
 456
 457         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 458
 459         permission_names[pdatum->value - 1] = (char *)k;
 460
 461         return 0;
 462 }
 463
 464 static void security_dump_masked_av(struct context *scontext,
 465                                     struct context *tcontext,
 466                                     u16 tclass,
 467                                     u32 permissions,
 468                                     const char *reason)
 469 {
 470         struct common_datum *common_dat;
 471         struct class_datum *tclass_dat;
 472         struct audit_buffer *ab;
 473         char *tclass_name;
 474         char *scontext_name = NULL;
 475         char *tcontext_name = NULL;
 476         char *permission_names[32];
 477         int index;
 478         u32 length;
 479         bool need_comma = false;
 480
 481         if (!permissions)
 482                 return;
 483
 484         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 485         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 486         common_dat = tclass_dat->comdatum;
 487
 488         /* init permission_names */
 489         if (common_dat &&
 490             hashtab_map(common_dat->permissions.table,
 491                         dump_masked_av_helper, permission_names) < 0)
 492                 goto out;
 493
 494         if (hashtab_map(tclass_dat->permissions.table,
 495                         dump_masked_av_helper, permission_names) < 0)
 496                 goto out;
 497
 498         /* get scontext/tcontext in text form */
 499         if (context_struct_to_string(scontext,
 500                                      &scontext_name, &length) < 0)
 501                 goto out;
 502
 503         if (context_struct_to_string(tcontext,
 504                                      &tcontext_name, &length) < 0)
 505                 goto out;
 506
 507         /* audit a message */
 508         ab = audit_log_start(current->audit_context,
 509                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 510         if (!ab)
 511                 goto out;
 512
 513         audit_log_format(ab, "op=security_compute_av reason=%s "
 514                          "scontext=%s tcontext=%s tclass=%s perms=",
 515                          reason, scontext_name, tcontext_name, tclass_name);
 516
 517         for (index = 0; index < 32; index++) {
 518                 u32 mask = (1 << index);
 519
 520                 if ((mask & permissions) == 0)
 521                         continue;
 522
 523                 audit_log_format(ab, "%s%s",
 524                                  need_comma ? "," : "",
 525                                  permission_names[index]
 526                                  ? permission_names[index] : "????");
 527                 need_comma = true;
 528         }
 529         audit_log_end(ab);
 530 out:
 531         /* release scontext/tcontext */
 532         kfree(tcontext_name);
 533         kfree(scontext_name);
 534
 535         return;
 536 }
 537
 538 /*
 539  * security_boundary_permission - drops violated permissions
 540  * on boundary constraint.
 541  */
 542 static void type_attribute_bounds_av(struct context *scontext,
 543                                      struct context *tcontext,
 544                                      u16 tclass,
 545                                      struct av_decision *avd)
 546 {
 547         struct context lo_scontext;
 548         struct context lo_tcontext, *tcontextp = tcontext;
 549         struct av_decision lo_avd;
 550         struct type_datum *source;
 551         struct type_datum *target;
 552         u32 masked = 0;
 553
 554         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 555                                     scontext->type - 1);
 556         BUG_ON(!source);
 557
 558         if (!source->bounds)
 559                 return;
 560
 561         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 562                                     tcontext->type - 1);
 563         BUG_ON(!target);
 564
 565         memset(&lo_avd, 0, sizeof(lo_avd));
 566
 567         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 568         lo_scontext.type = source->bounds;
 569
 570         if (target->bounds) {
 571                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 572                 lo_tcontext.type = target->bounds;
 573                 tcontextp = &lo_tcontext;
 574         }
 575
 576         context_struct_compute_av(&lo_scontext,
 577                                   tcontextp,
 578                                   tclass,
 579                                   &lo_avd,
 580                                   NULL);
 581
 582         masked = ~lo_avd.allowed & avd->allowed;
 583
 584         if (likely(!masked))
 585                 return;         /* no masked permission */
 586
 587         /* mask violated permissions */
 588         avd->allowed &= ~masked;
 589
 590         /* audit masked permissions */
 591         security_dump_masked_av(scontext, tcontext,
 592                                 tclass, masked, "bounds");
 593 }
 594
 595 /*
 596  * flag which drivers have permissions
 597  * only looking for ioctl based extended permssions
 598  */
 599 void services_compute_xperms_drivers(
 600                 struct extended_perms *xperms,
 601                 struct avtab_node *node)
 602 {
 603         unsigned int i;
 604
 605         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 606                 /* if one or more driver has all permissions allowed */
 607                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 608                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 609         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 610                 /* if allowing permissions within a driver */
 611                 security_xperm_set(xperms->drivers.p,
 612                                         node->datum.u.xperms->driver);
 613         }
 614
 615         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 616         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 617                 xperms->len = 1;
 618 }
 619
 620 /*
 621  * Compute access vectors and extended permissions based on a context
 622  * structure pair for the permissions in a particular class.
 623  */
 624 static void context_struct_compute_av(struct context *scontext,
 625                                         struct context *tcontext,
 626                                         u16 tclass,
 627                                         struct av_decision *avd,
 628                                         struct extended_perms *xperms)
 629 {
 630         struct constraint_node *constraint;
 631         struct role_allow *ra;
 632         struct avtab_key avkey;
 633         struct avtab_node *node;
 634         struct class_datum *tclass_datum;
 635         struct ebitmap *sattr, *tattr;
 636         struct ebitmap_node *snode, *tnode;
 637         unsigned int i, j;
 638
 639         avd->allowed = 0;
 640         avd->auditallow = 0;
 641         avd->auditdeny = 0xffffffff;
 642         if (xperms) {
 643                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 644                 xperms->len = 0;
 645         }
 646
 647         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 648                 if (printk_ratelimit())
 649                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 650                 return;
 651         }
 652
 653         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 654
 655         /*
 656          * If a specific type enforcement rule was defined for
 657          * this permission check, then use it.
 658          */
 659         avkey.target_class = tclass;
 660         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 661         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 662         BUG_ON(!sattr);
 663         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 664         BUG_ON(!tattr);
 665         ebitmap_for_each_positive_bit(sattr, snode, i) {
 666                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 667                         avkey.source_type = i + 1;
 668                         avkey.target_type = j + 1;
 669                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 670                              node;
 671                              node = avtab_search_node_next(node, avkey.specified)) {
 672                                 if (node->key.specified == AVTAB_ALLOWED)
 673                                         avd->allowed |= node->datum.u.data;
 674                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 675                                         avd->auditallow |= node->datum.u.data;
 676                                 else if (node->key.specified == AVTAB_AUDITDENY)
 677                                         avd->auditdeny &= node->datum.u.data;
 678                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 679                                         services_compute_xperms_drivers(xperms, node);
 680                         }
 681
 682                         /* Check conditional av table for additional permissions */
 683                         cond_compute_av(&policydb.te_cond_avtab, &avkey,
 684                                         avd, xperms);
 685
 686                 }
 687         }
 688
 689         /*
 690          * Remove any permissions prohibited by a constraint (this includes
 691          * the MLS policy).
 692          */
 693         constraint = tclass_datum->constraints;
 694         while (constraint) {
 695                 if ((constraint->permissions & (avd->allowed)) &&
 696                     !constraint_expr_eval(scontext, tcontext, NULL,
 697                                           constraint->expr)) {
 698                         avd->allowed &= ~(constraint->permissions);
 699                 }
 700                 constraint = constraint->next;
 701         }
 702
 703         /*
 704          * If checking process transition permission and the
 705          * role is changing, then check the (current_role, new_role)
 706          * pair.
 707          */
 708         if (tclass == policydb.process_class &&
 709             (avd->allowed & policydb.process_trans_perms) &&
 710             scontext->role != tcontext->role) {
 711                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 712                         if (scontext->role == ra->role &&
 713                             tcontext->role == ra->new_role)
 714                                 break;
 715                 }
 716                 if (!ra)
 717                         avd->allowed &= ~policydb.process_trans_perms;
 718         }
 719
 720         /*
 721          * If the given source and target types have boundary
 722          * constraint, lazy checks have to mask any violated
 723          * permission and notice it to userspace via audit.
 724          */
 725         type_attribute_bounds_av(scontext, tcontext,
 726                                  tclass, avd);
 727 }
 728
 729 static int security_validtrans_handle_fail(struct context *ocontext,
 730                                            struct context *ncontext,
 731                                            struct context *tcontext,
 732                                            u16 tclass)
 733 {
 734         char *o = NULL, *n = NULL, *t = NULL;
 735         u32 olen, nlen, tlen;
 736
 737         if (context_struct_to_string(ocontext, &o, &olen))
 738                 goto out;
 739         if (context_struct_to_string(ncontext, &n, &nlen))
 740                 goto out;
 741         if (context_struct_to_string(tcontext, &t, &tlen))
 742                 goto out;
 743         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 744                   "op=security_validate_transition seresult=denied"
 745                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 746                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 747 out:
 748         kfree(o);
 749         kfree(n);
 750         kfree(t);
 751
 752         if (!selinux_enforcing)
 753                 return 0;
 754         return -EPERM;
 755 }
 756
 757 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
 758                                           u16 orig_tclass, bool user)
 759 {
 760         struct context *ocontext;
 761         struct context *ncontext;
 762         struct context *tcontext;
 763         struct class_datum *tclass_datum;
 764         struct constraint_node *constraint;
 765         u16 tclass;
 766         int rc = 0;
 767
 768         if (!ss_initialized)
 769                 return 0;
 770
 771         read_lock(&policy_rwlock);
 772
 773         if (!user)
 774                 tclass = unmap_class(orig_tclass);
 775         else
 776                 tclass = orig_tclass;
 777
 778         if (!tclass || tclass > policydb.p_classes.nprim) {
 779                 rc = -EINVAL;
 780                 goto out;
 781         }
 782         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 783
 784         ocontext = sidtab_search(&sidtab, oldsid);
 785         if (!ocontext) {
 786                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 787                         __func__, oldsid);
 788                 rc = -EINVAL;
 789                 goto out;
 790         }
 791
 792         ncontext = sidtab_search(&sidtab, newsid);
 793         if (!ncontext) {
 794                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 795                         __func__, newsid);
 796                 rc = -EINVAL;
 797                 goto out;
 798         }
 799
 800         tcontext = sidtab_search(&sidtab, tasksid);
 801         if (!tcontext) {
 802                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 803                         __func__, tasksid);
 804                 rc = -EINVAL;
 805                 goto out;
 806         }
 807
 808         constraint = tclass_datum->validatetrans;
 809         while (constraint) {
 810                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 811                                           constraint->expr)) {
 812                         if (user)
 813                                 rc = -EPERM;
 814                         else
 815                                 rc = security_validtrans_handle_fail(ocontext,
 816                                                                      ncontext,
 817                                                                      tcontext,
 818                                                                      tclass);
 819                         goto out;
 820                 }
 821                 constraint = constraint->next;
 822         }
 823
 824 out:
 825         read_unlock(&policy_rwlock);
 826         return rc;
 827 }
 828
 829 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
 830                                         u16 tclass)
 831 {
 832         return security_compute_validatetrans(oldsid, newsid, tasksid,
 833                                                 tclass, true);
 834 }
 835
 836 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 837                                  u16 orig_tclass)
 838 {
 839         return security_compute_validatetrans(oldsid, newsid, tasksid,
 840                                                 orig_tclass, false);
 841 }
 842
 843 /*
 844  * security_bounded_transition - check whether the given
 845  * transition is directed to bounded, or not.
 846  * It returns 0, if @newsid is bounded by @oldsid.
 847  * Otherwise, it returns error code.
 848  *
 849  * @oldsid : current security identifier
 850  * @newsid : destinated security identifier
 851  */
 852 int security_bounded_transition(u32 old_sid, u32 new_sid)
 853 {
 854         struct context *old_context, *new_context;
 855         struct type_datum *type;
 856         int index;
 857         int rc;
 858
 859         read_lock(&policy_rwlock);
 860
 861         rc = -EINVAL;
 862         old_context = sidtab_search(&sidtab, old_sid);
 863         if (!old_context) {
 864                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 865                        __func__, old_sid);
 866                 goto out;
 867         }
 868
 869         rc = -EINVAL;
 870         new_context = sidtab_search(&sidtab, new_sid);
 871         if (!new_context) {
 872                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 873                        __func__, new_sid);
 874                 goto out;
 875         }
 876
 877         rc = 0;
 878         /* type/domain unchanged */
 879         if (old_context->type == new_context->type)
 880                 goto out;
 881
 882         index = new_context->type;
 883         while (true) {
 884                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 885                                           index - 1);
 886                 BUG_ON(!type);
 887
 888                 /* not bounded anymore */
 889                 rc = -EPERM;
 890                 if (!type->bounds)
 891                         break;
 892
 893                 /* @newsid is bounded by @oldsid */
 894                 rc = 0;
 895                 if (type->bounds == old_context->type)
 896                         break;
 897
 898                 index = type->bounds;
 899         }
 900
 901         if (rc) {
 902                 char *old_name = NULL;
 903                 char *new_name = NULL;
 904                 u32 length;
 905
 906                 if (!context_struct_to_string(old_context,
 907                                               &old_name, &length) &&
 908                     !context_struct_to_string(new_context,
 909                                               &new_name, &length)) {
 910                         audit_log(current->audit_context,
 911                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 912                                   "op=security_bounded_transition "
 913                                   "seresult=denied "
 914                                   "oldcontext=%s newcontext=%s",
 915                                   old_name, new_name);
 916                 }
 917                 kfree(new_name);
 918                 kfree(old_name);
 919         }
 920 out:
 921         read_unlock(&policy_rwlock);
 922
 923         return rc;
 924 }
 925
 926 static void avd_init(struct av_decision *avd)
 927 {
 928         avd->allowed = 0;
 929         avd->auditallow = 0;
 930         avd->auditdeny = 0xffffffff;
 931         avd->seqno = latest_granting;
 932         avd->flags = 0;
 933 }
 934
 935 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 936                                         struct avtab_node *node)
 937 {
 938         unsigned int i;
 939
 940         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 941                 if (xpermd->driver != node->datum.u.xperms->driver)
 942                         return;
 943         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 944                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 945                                         xpermd->driver))
 946                         return;
 947         } else {
 948                 BUG();
 949         }
 950
 951         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 952                 xpermd->used |= XPERMS_ALLOWED;
 953                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 954                         memset(xpermd->allowed->p, 0xff,
 955                                         sizeof(xpermd->allowed->p));
 956                 }
 957                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 958                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 959                                 xpermd->allowed->p[i] |=
 960                                         node->datum.u.xperms->perms.p[i];
 961                 }
 962         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 963                 xpermd->used |= XPERMS_AUDITALLOW;
 964                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 965                         memset(xpermd->auditallow->p, 0xff,
 966                                         sizeof(xpermd->auditallow->p));
 967                 }
 968                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 969                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 970                                 xpermd->auditallow->p[i] |=
 971                                         node->datum.u.xperms->perms.p[i];
 972                 }
 973         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 974                 xpermd->used |= XPERMS_DONTAUDIT;
 975                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 976                         memset(xpermd->dontaudit->p, 0xff,
 977                                         sizeof(xpermd->dontaudit->p));
 978                 }
 979                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 980                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 981                                 xpermd->dontaudit->p[i] |=
 982                                         node->datum.u.xperms->perms.p[i];
 983                 }
 984         } else {
 985                 BUG();
 986         }
 987 }
 988
 989 void security_compute_xperms_decision(u32 ssid,
 990                                 u32 tsid,
 991                                 u16 orig_tclass,
 992                                 u8 driver,
 993                                 struct extended_perms_decision *xpermd)
 994 {
 995         u16 tclass;
 996         struct context *scontext, *tcontext;
 997         struct avtab_key avkey;
 998         struct avtab_node *node;
 999         struct ebitmap *sattr, *tattr;
1000         struct ebitmap_node *snode, *tnode;
1001         unsigned int i, j;
1002
1003         xpermd->driver = driver;
1004         xpermd->used = 0;
1005         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1006         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1007         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1008
1009         read_lock(&policy_rwlock);
1010         if (!ss_initialized)
1011                 goto allow;
1012
1013         scontext = sidtab_search(&sidtab, ssid);
1014         if (!scontext) {
1015                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1016                        __func__, ssid);
1017                 goto out;
1018         }
1019
1020         tcontext = sidtab_search(&sidtab, tsid);
1021         if (!tcontext) {
1022                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1023                        __func__, tsid);
1024                 goto out;
1025         }
1026
1027         tclass = unmap_class(orig_tclass);
1028         if (unlikely(orig_tclass && !tclass)) {
1029                 if (policydb.allow_unknown)
1030                         goto allow;
1031                 goto out;
1032         }
1033
1034
1035         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
1036                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1037                 goto out;
1038         }
1039
1040         avkey.target_class = tclass;
1041         avkey.specified = AVTAB_XPERMS;
1042         sattr = flex_array_get(policydb.type_attr_map_array,
1043                                 scontext->type - 1);
1044         BUG_ON(!sattr);
1045         tattr = flex_array_get(policydb.type_attr_map_array,
1046                                 tcontext->type - 1);
1047         BUG_ON(!tattr);
1048         ebitmap_for_each_positive_bit(sattr, snode, i) {
1049                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1050                         avkey.source_type = i + 1;
1051                         avkey.target_type = j + 1;
1052                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
1053                              node;
1054                              node = avtab_search_node_next(node, avkey.specified))
1055                                 services_compute_xperms_decision(xpermd, node);
1056
1057                         cond_compute_xperms(&policydb.te_cond_avtab,
1058                                                 &avkey, xpermd);
1059                 }
1060         }
1061 out:
1062         read_unlock(&policy_rwlock);
1063         return;
1064 allow:
1065         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1066         goto out;
1067 }
1068
1069 /**
1070  * security_compute_av - Compute access vector decisions.
1071  * @ssid: source security identifier
1072  * @tsid: target security identifier
1073  * @tclass: target security class
1074  * @avd: access vector decisions
1075  * @xperms: extended permissions
1076  *
1077  * Compute a set of access vector decisions based on the
1078  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1079  */
1080 void security_compute_av(u32 ssid,
1081                          u32 tsid,
1082                          u16 orig_tclass,
1083                          struct av_decision *avd,
1084                          struct extended_perms *xperms)
1085 {
1086         u16 tclass;
1087         struct context *scontext = NULL, *tcontext = NULL;
1088
1089         read_lock(&policy_rwlock);
1090         avd_init(avd);
1091         xperms->len = 0;
1092         if (!ss_initialized)
1093                 goto allow;
1094
1095         scontext = sidtab_search(&sidtab, ssid);
1096         if (!scontext) {
1097                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1098                        __func__, ssid);
1099                 goto out;
1100         }
1101
1102         /* permissive domain? */
1103         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1104                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1105
1106         tcontext = sidtab_search(&sidtab, tsid);
1107         if (!tcontext) {
1108                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1109                        __func__, tsid);
1110                 goto out;
1111         }
1112
1113         tclass = unmap_class(orig_tclass);
1114         if (unlikely(orig_tclass && !tclass)) {
1115                 if (policydb.allow_unknown)
1116                         goto allow;
1117                 goto out;
1118         }
1119         context_struct_compute_av(scontext, tcontext, tclass, avd, xperms);
1120         map_decision(orig_tclass, avd, policydb.allow_unknown);
1121 out:
1122         read_unlock(&policy_rwlock);
1123         return;
1124 allow:
1125         avd->allowed = 0xffffffff;
1126         goto out;
1127 }
1128
1129 void security_compute_av_user(u32 ssid,
1130                               u32 tsid,
1131                               u16 tclass,
1132                               struct av_decision *avd)
1133 {
1134         struct context *scontext = NULL, *tcontext = NULL;
1135
1136         read_lock(&policy_rwlock);
1137         avd_init(avd);
1138         if (!ss_initialized)
1139                 goto allow;
1140
1141         scontext = sidtab_search(&sidtab, ssid);
1142         if (!scontext) {
1143                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1144                        __func__, ssid);
1145                 goto out;
1146         }
1147
1148         /* permissive domain? */
1149         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
1150                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1151
1152         tcontext = sidtab_search(&sidtab, tsid);
1153         if (!tcontext) {
1154                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1155                        __func__, tsid);
1156                 goto out;
1157         }
1158
1159         if (unlikely(!tclass)) {
1160                 if (policydb.allow_unknown)
1161                         goto allow;
1162                 goto out;
1163         }
1164
1165         context_struct_compute_av(scontext, tcontext, tclass, avd, NULL);
1166  out:
1167         read_unlock(&policy_rwlock);
1168         return;
1169 allow:
1170         avd->allowed = 0xffffffff;
1171         goto out;
1172 }
1173
1174 /*
1175  * Write the security context string representation of
1176  * the context structure `context' into a dynamically
1177  * allocated string of the correct size.  Set `*scontext'
1178  * to point to this string and set `*scontext_len' to
1179  * the length of the string.
1180  */
1181 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1182 {
1183         char *scontextp;
1184
1185         if (scontext)
1186                 *scontext = NULL;
1187         *scontext_len = 0;
1188
1189         if (context->len) {
1190                 *scontext_len = context->len;
1191                 if (scontext) {
1192                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1193                         if (!(*scontext))
1194                                 return -ENOMEM;
1195                 }
1196                 return 0;
1197         }
1198
1199         /* Compute the size of the context. */
1200         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1201         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1202         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1203         *scontext_len += mls_compute_context_len(context);
1204
1205         if (!scontext)
1206                 return 0;
1207
1208         /* Allocate space for the context; caller must free this space. */
1209         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1210         if (!scontextp)
1211                 return -ENOMEM;
1212         *scontext = scontextp;
1213
1214         /*
1215          * Copy the user name, role name and type name into the context.
1216          */
1217         scontextp += sprintf(scontextp, "%s:%s:%s",
1218                 sym_name(&policydb, SYM_USERS, context->user - 1),
1219                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1220                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1221
1222         mls_sid_to_context(context, &scontextp);
1223
1224         *scontextp = 0;
1225
1226         return 0;
1227 }
1228
1229 #include "initial_sid_to_string.h"
1230
1231 const char *security_get_initial_sid_context(u32 sid)
1232 {
1233         if (unlikely(sid > SECINITSID_NUM))
1234                 return NULL;
1235         return initial_sid_to_string[sid];
1236 }
1237
1238 static int security_sid_to_context_core(u32 sid, char **scontext,
1239                                         u32 *scontext_len, int force)
1240 {
1241         struct context *context;
1242         int rc = 0;
1243
1244         if (scontext)
1245                 *scontext = NULL;
1246         *scontext_len  = 0;
1247
1248         if (!ss_initialized) {
1249                 if (sid <= SECINITSID_NUM) {
1250                         char *scontextp;
1251
1252                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1253                         if (!scontext)
1254                                 goto out;
1255                         scontextp = kmemdup(initial_sid_to_string[sid],
1256                                             *scontext_len, GFP_ATOMIC);
1257                         if (!scontextp) {
1258                                 rc = -ENOMEM;
1259                                 goto out;
1260                         }
1261                         *scontext = scontextp;
1262                         goto out;
1263                 }
1264                 printk(KERN_ERR "SELinux: %s:  called before initial "
1265                        "load_policy on unknown SID %d\n", __func__, sid);
1266                 rc = -EINVAL;
1267                 goto out;
1268         }
1269         read_lock(&policy_rwlock);
1270         if (force)
1271                 context = sidtab_search_force(&sidtab, sid);
1272         else
1273                 context = sidtab_search(&sidtab, sid);
1274         if (!context) {
1275                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1276                         __func__, sid);
1277                 rc = -EINVAL;
1278                 goto out_unlock;
1279         }
1280         rc = context_struct_to_string(context, scontext, scontext_len);
1281 out_unlock:
1282         read_unlock(&policy_rwlock);
1283 out:
1284         return rc;
1285
1286 }
1287
1288 /**
1289  * security_sid_to_context - Obtain a context for a given SID.
1290  * @sid: security identifier, SID
1291  * @scontext: security context
1292  * @scontext_len: length in bytes
1293  *
1294  * Write the string representation of the context associated with @sid
1295  * into a dynamically allocated string of the correct size.  Set @scontext
1296  * to point to this string and set @scontext_len to the length of the string.
1297  */
1298 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1299 {
1300         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1301 }
1302
1303 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1304 {
1305         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1306 }
1307
1308 /*
1309  * Caveat:  Mutates scontext.
1310  */
1311 static int string_to_context_struct(struct policydb *pol,
1312                                     struct sidtab *sidtabp,
1313                                     char *scontext,
1314                                     u32 scontext_len,
1315                                     struct context *ctx,
1316                                     u32 def_sid)
1317 {
1318         struct role_datum *role;
1319         struct type_datum *typdatum;
1320         struct user_datum *usrdatum;
1321         char *scontextp, *p, oldc;
1322         int rc = 0;
1323
1324         context_init(ctx);
1325
1326         /* Parse the security context. */
1327
1328         rc = -EINVAL;
1329         scontextp = (char *) scontext;
1330
1331         /* Extract the user. */
1332         p = scontextp;
1333         while (*p && *p != ':')
1334                 p++;
1335
1336         if (*p == 0)
1337                 goto out;
1338
1339         *p++ = 0;
1340
1341         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1342         if (!usrdatum)
1343                 goto out;
1344
1345         ctx->user = usrdatum->value;
1346
1347         /* Extract role. */
1348         scontextp = p;
1349         while (*p && *p != ':')
1350                 p++;
1351
1352         if (*p == 0)
1353                 goto out;
1354
1355         *p++ = 0;
1356
1357         role = hashtab_search(pol->p_roles.table, scontextp);
1358         if (!role)
1359                 goto out;
1360         ctx->role = role->value;
1361
1362         /* Extract type. */
1363         scontextp = p;
1364         while (*p && *p != ':')
1365                 p++;
1366         oldc = *p;
1367         *p++ = 0;
1368
1369         typdatum = hashtab_search(pol->p_types.table, scontextp);
1370         if (!typdatum || typdatum->attribute)
1371                 goto out;
1372
1373         ctx->type = typdatum->value;
1374
1375         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1376         if (rc)
1377                 goto out;
1378
1379         rc = -EINVAL;
1380         if ((p - scontext) < scontext_len)
1381                 goto out;
1382
1383         /* Check the validity of the new context. */
1384         if (!policydb_context_isvalid(pol, ctx))
1385                 goto out;
1386         rc = 0;
1387 out:
1388         if (rc)
1389                 context_destroy(ctx);
1390         return rc;
1391 }
1392
1393 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1394                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1395                                         int force)
1396 {
1397         char *scontext2, *str = NULL;
1398         struct context context;
1399         int rc = 0;
1400
1401         /* An empty security context is never valid. */
1402         if (!scontext_len)
1403                 return -EINVAL;
1404
1405         if (!ss_initialized) {
1406                 int i;
1407
1408                 for (i = 1; i < SECINITSID_NUM; i++) {
1409                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1410                                 *sid = i;
1411                                 return 0;
1412                         }
1413                 }
1414                 *sid = SECINITSID_KERNEL;
1415                 return 0;
1416         }
1417         *sid = SECSID_NULL;
1418
1419         /* Copy the string so that we can modify the copy as we parse it. */
1420         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1421         if (!scontext2)
1422                 return -ENOMEM;
1423         memcpy(scontext2, scontext, scontext_len);
1424         scontext2[scontext_len] = 0;
1425
1426         if (force) {
1427                 /* Save another copy for storing in uninterpreted form */
1428                 rc = -ENOMEM;
1429                 str = kstrdup(scontext2, gfp_flags);
1430                 if (!str)
1431                         goto out;
1432         }
1433
1434         read_lock(&policy_rwlock);
1435         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1436                                       scontext_len, &context, def_sid);
1437         if (rc == -EINVAL && force) {
1438                 context.str = str;
1439                 context.len = scontext_len;
1440                 str = NULL;
1441         } else if (rc)
1442                 goto out_unlock;
1443         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1444         context_destroy(&context);
1445 out_unlock:
1446         read_unlock(&policy_rwlock);
1447 out:
1448         kfree(scontext2);
1449         kfree(str);
1450         return rc;
1451 }
1452
1453 /**
1454  * security_context_to_sid - Obtain a SID for a given security context.
1455  * @scontext: security context
1456  * @scontext_len: length in bytes
1457  * @sid: security identifier, SID
1458  * @gfp: context for the allocation
1459  *
1460  * Obtains a SID associated with the security context that
1461  * has the string representation specified by @scontext.
1462  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1463  * memory is available, or 0 on success.
1464  */
1465 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid,
1466                             gfp_t gfp)
1467 {
1468         return security_context_to_sid_core(scontext, scontext_len,
1469                                             sid, SECSID_NULL, gfp, 0);
1470 }
1471
1472 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp)
1473 {
1474         return security_context_to_sid(scontext, strlen(scontext), sid, gfp);
1475 }
1476
1477 /**
1478  * security_context_to_sid_default - Obtain a SID for a given security context,
1479  * falling back to specified default if needed.
1480  *
1481  * @scontext: security context
1482  * @scontext_len: length in bytes
1483  * @sid: security identifier, SID
1484  * @def_sid: default SID to assign on error
1485  *
1486  * Obtains a SID associated with the security context that
1487  * has the string representation specified by @scontext.
1488  * The default SID is passed to the MLS layer to be used to allow
1489  * kernel labeling of the MLS field if the MLS field is not present
1490  * (for upgrading to MLS without full relabel).
1491  * Implicitly forces adding of the context even if it cannot be mapped yet.
1492  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1493  * memory is available, or 0 on success.
1494  */
1495 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1496                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1497 {
1498         return security_context_to_sid_core(scontext, scontext_len,
1499                                             sid, def_sid, gfp_flags, 1);
1500 }
1501
1502 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1503                                   u32 *sid)
1504 {
1505         return security_context_to_sid_core(scontext, scontext_len,
1506                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1507 }
1508
1509 static int compute_sid_handle_invalid_context(
1510         struct context *scontext,
1511         struct context *tcontext,
1512         u16 tclass,
1513         struct context *newcontext)
1514 {
1515         char *s = NULL, *t = NULL, *n = NULL;
1516         u32 slen, tlen, nlen;
1517
1518         if (context_struct_to_string(scontext, &s, &slen))
1519                 goto out;
1520         if (context_struct_to_string(tcontext, &t, &tlen))
1521                 goto out;
1522         if (context_struct_to_string(newcontext, &n, &nlen))
1523                 goto out;
1524         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1525                   "op=security_compute_sid invalid_context=%s"
1526                   " scontext=%s"
1527                   " tcontext=%s"
1528                   " tclass=%s",
1529                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1530 out:
1531         kfree(s);
1532         kfree(t);
1533         kfree(n);
1534         if (!selinux_enforcing)
1535                 return 0;
1536         return -EACCES;
1537 }
1538
1539 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1540                                   u32 stype, u32 ttype, u16 tclass,
1541                                   const char *objname)
1542 {
1543         struct filename_trans ft;
1544         struct filename_trans_datum *otype;
1545
1546         /*
1547          * Most filename trans rules are going to live in specific directories
1548          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1549          * if the ttype does not contain any rules.
1550          */
1551         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1552                 return;
1553
1554         ft.stype = stype;
1555         ft.ttype = ttype;
1556         ft.tclass = tclass;
1557         ft.name = objname;
1558
1559         otype = hashtab_search(p->filename_trans, &ft);
1560         if (otype)
1561                 newcontext->type = otype->otype;
1562 }
1563
1564 static int security_compute_sid(u32 ssid,
1565                                 u32 tsid,
1566                                 u16 orig_tclass,
1567                                 u32 specified,
1568                                 const char *objname,
1569                                 u32 *out_sid,
1570                                 bool kern)
1571 {
1572         struct class_datum *cladatum = NULL;
1573         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1574         struct role_trans *roletr = NULL;
1575         struct avtab_key avkey;
1576         struct avtab_datum *avdatum;
1577         struct avtab_node *node;
1578         u16 tclass;
1579         int rc = 0;
1580         bool sock;
1581
1582         if (!ss_initialized) {
1583                 switch (orig_tclass) {
1584                 case SECCLASS_PROCESS: /* kernel value */
1585                         *out_sid = ssid;
1586                         break;
1587                 default:
1588                         *out_sid = tsid;
1589                         break;
1590                 }
1591                 goto out;
1592         }
1593
1594         context_init(&newcontext);
1595
1596         read_lock(&policy_rwlock);
1597
1598         if (kern) {
1599                 tclass = unmap_class(orig_tclass);
1600                 sock = security_is_socket_class(orig_tclass);
1601         } else {
1602                 tclass = orig_tclass;
1603                 sock = security_is_socket_class(map_class(tclass));
1604         }
1605
1606         scontext = sidtab_search(&sidtab, ssid);
1607         if (!scontext) {
1608                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1609                        __func__, ssid);
1610                 rc = -EINVAL;
1611                 goto out_unlock;
1612         }
1613         tcontext = sidtab_search(&sidtab, tsid);
1614         if (!tcontext) {
1615                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1616                        __func__, tsid);
1617                 rc = -EINVAL;
1618                 goto out_unlock;
1619         }
1620
1621         if (tclass && tclass <= policydb.p_classes.nprim)
1622                 cladatum = policydb.class_val_to_struct[tclass - 1];
1623
1624         /* Set the user identity. */
1625         switch (specified) {
1626         case AVTAB_TRANSITION:
1627         case AVTAB_CHANGE:
1628                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1629                         newcontext.user = tcontext->user;
1630                 } else {
1631                         /* notice this gets both DEFAULT_SOURCE and unset */
1632                         /* Use the process user identity. */
1633                         newcontext.user = scontext->user;
1634                 }
1635                 break;
1636         case AVTAB_MEMBER:
1637                 /* Use the related object owner. */
1638                 newcontext.user = tcontext->user;
1639                 break;
1640         }
1641
1642         /* Set the role to default values. */
1643         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1644                 newcontext.role = scontext->role;
1645         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1646                 newcontext.role = tcontext->role;
1647         } else {
1648                 if ((tclass == policydb.process_class) || (sock == true))
1649                         newcontext.role = scontext->role;
1650                 else
1651                         newcontext.role = OBJECT_R_VAL;
1652         }
1653
1654         /* Set the type to default values. */
1655         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1656                 newcontext.type = scontext->type;
1657         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1658                 newcontext.type = tcontext->type;
1659         } else {
1660                 if ((tclass == policydb.process_class) || (sock == true)) {
1661                         /* Use the type of process. */
1662                         newcontext.type = scontext->type;
1663                 } else {
1664                         /* Use the type of the related object. */
1665                         newcontext.type = tcontext->type;
1666                 }
1667         }
1668
1669         /* Look for a type transition/member/change rule. */
1670         avkey.source_type = scontext->type;
1671         avkey.target_type = tcontext->type;
1672         avkey.target_class = tclass;
1673         avkey.specified = specified;
1674         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1675
1676         /* If no permanent rule, also check for enabled conditional rules */
1677         if (!avdatum) {
1678                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1679                 for (; node; node = avtab_search_node_next(node, specified)) {
1680                         if (node->key.specified & AVTAB_ENABLED) {
1681                                 avdatum = &node->datum;
1682                                 break;
1683                         }
1684                 }
1685         }
1686
1687         if (avdatum) {
1688                 /* Use the type from the type transition/member/change rule. */
1689                 newcontext.type = avdatum->u.data;
1690         }
1691
1692         /* if we have a objname this is a file trans check so check those rules */
1693         if (objname)
1694                 filename_compute_type(&policydb, &newcontext, scontext->type,
1695                                       tcontext->type, tclass, objname);
1696
1697         /* Check for class-specific changes. */
1698         if (specified & AVTAB_TRANSITION) {
1699                 /* Look for a role transition rule. */
1700                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1701                         if ((roletr->role == scontext->role) &&
1702                             (roletr->type == tcontext->type) &&
1703                             (roletr->tclass == tclass)) {
1704                                 /* Use the role transition rule. */
1705                                 newcontext.role = roletr->new_role;
1706                                 break;
1707                         }
1708                 }
1709         }
1710
1711         /* Set the MLS attributes.
1712            This is done last because it may allocate memory. */
1713         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1714                              &newcontext, sock);
1715         if (rc)
1716                 goto out_unlock;
1717
1718         /* Check the validity of the context. */
1719         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1720                 rc = compute_sid_handle_invalid_context(scontext,
1721                                                         tcontext,
1722                                                         tclass,
1723                                                         &newcontext);
1724                 if (rc)
1725                         goto out_unlock;
1726         }
1727         /* Obtain the sid for the context. */
1728         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1729 out_unlock:
1730         read_unlock(&policy_rwlock);
1731         context_destroy(&newcontext);
1732 out:
1733         return rc;
1734 }
1735
1736 /**
1737  * security_transition_sid - Compute the SID for a new subject/object.
1738  * @ssid: source security identifier
1739  * @tsid: target security identifier
1740  * @tclass: target security class
1741  * @out_sid: security identifier for new subject/object
1742  *
1743  * Compute a SID to use for labeling a new subject or object in the
1744  * class @tclass based on a SID pair (@ssid, @tsid).
1745  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1746  * if insufficient memory is available, or %0 if the new SID was
1747  * computed successfully.
1748  */
1749 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1750                             const struct qstr *qstr, u32 *out_sid)
1751 {
1752         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1753                                     qstr ? qstr->name : NULL, out_sid, true);
1754 }
1755
1756 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1757                                  const char *objname, u32 *out_sid)
1758 {
1759         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1760                                     objname, out_sid, false);
1761 }
1762
1763 /**
1764  * security_member_sid - Compute the SID for member selection.
1765  * @ssid: source security identifier
1766  * @tsid: target security identifier
1767  * @tclass: target security class
1768  * @out_sid: security identifier for selected member
1769  *
1770  * Compute a SID to use when selecting a member of a polyinstantiated
1771  * object of class @tclass based on a SID pair (@ssid, @tsid).
1772  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1773  * if insufficient memory is available, or %0 if the SID was
1774  * computed successfully.
1775  */
1776 int security_member_sid(u32 ssid,
1777                         u32 tsid,
1778                         u16 tclass,
1779                         u32 *out_sid)
1780 {
1781         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1782                                     out_sid, false);
1783 }
1784
1785 /**
1786  * security_change_sid - Compute the SID for object relabeling.
1787  * @ssid: source security identifier
1788  * @tsid: target security identifier
1789  * @tclass: target security class
1790  * @out_sid: security identifier for selected member
1791  *
1792  * Compute a SID to use for relabeling an object of class @tclass
1793  * based on a SID pair (@ssid, @tsid).
1794  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1795  * if insufficient memory is available, or %0 if the SID was
1796  * computed successfully.
1797  */
1798 int security_change_sid(u32 ssid,
1799                         u32 tsid,
1800                         u16 tclass,
1801                         u32 *out_sid)
1802 {
1803         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1804                                     out_sid, false);
1805 }
1806
1807 /* Clone the SID into the new SID table. */
1808 static int clone_sid(u32 sid,
1809                      struct context *context,
1810                      void *arg)
1811 {
1812         struct sidtab *s = arg;
1813
1814         if (sid > SECINITSID_NUM)
1815                 return sidtab_insert(s, sid, context);
1816         else
1817                 return 0;
1818 }
1819
1820 static inline int convert_context_handle_invalid_context(struct context *context)
1821 {
1822         char *s;
1823         u32 len;
1824
1825         if (selinux_enforcing)
1826                 return -EINVAL;
1827
1828         if (!context_struct_to_string(context, &s, &len)) {
1829                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1830                 kfree(s);
1831         }
1832         return 0;
1833 }
1834
1835 struct convert_context_args {
1836         struct policydb *oldp;
1837         struct policydb *newp;
1838 };
1839
1840 /*
1841  * Convert the values in the security context
1842  * structure `c' from the values specified
1843  * in the policy `p->oldp' to the values specified
1844  * in the policy `p->newp'.  Verify that the
1845  * context is valid under the new policy.
1846  */
1847 static int convert_context(u32 key,
1848                            struct context *c,
1849                            void *p)
1850 {
1851         struct convert_context_args *args;
1852         struct context oldc;
1853         struct ocontext *oc;
1854         struct mls_range *range;
1855         struct role_datum *role;
1856         struct type_datum *typdatum;
1857         struct user_datum *usrdatum;
1858         char *s;
1859         u32 len;
1860         int rc = 0;
1861
1862         if (key <= SECINITSID_NUM)
1863                 goto out;
1864
1865         args = p;
1866
1867         if (c->str) {
1868                 struct context ctx;
1869
1870                 rc = -ENOMEM;
1871                 s = kstrdup(c->str, GFP_KERNEL);
1872                 if (!s)
1873                         goto out;
1874
1875                 rc = string_to_context_struct(args->newp, NULL, s,
1876                                               c->len, &ctx, SECSID_NULL);
1877                 kfree(s);
1878                 if (!rc) {
1879                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1880                                c->str);
1881                         /* Replace string with mapped representation. */
1882                         kfree(c->str);
1883                         memcpy(c, &ctx, sizeof(*c));
1884                         goto out;
1885                 } else if (rc == -EINVAL) {
1886                         /* Retain string representation for later mapping. */
1887                         rc = 0;
1888                         goto out;
1889                 } else {
1890                         /* Other error condition, e.g. ENOMEM. */
1891                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1892                                c->str, -rc);
1893                         goto out;
1894                 }
1895         }
1896
1897         rc = context_cpy(&oldc, c);
1898         if (rc)
1899                 goto out;
1900
1901         /* Convert the user. */
1902         rc = -EINVAL;
1903         usrdatum = hashtab_search(args->newp->p_users.table,
1904                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1905         if (!usrdatum)
1906                 goto bad;
1907         c->user = usrdatum->value;
1908
1909         /* Convert the role. */
1910         rc = -EINVAL;
1911         role = hashtab_search(args->newp->p_roles.table,
1912                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1913         if (!role)
1914                 goto bad;
1915         c->role = role->value;
1916
1917         /* Convert the type. */
1918         rc = -EINVAL;
1919         typdatum = hashtab_search(args->newp->p_types.table,
1920                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1921         if (!typdatum)
1922                 goto bad;
1923         c->type = typdatum->value;
1924
1925         /* Convert the MLS fields if dealing with MLS policies */
1926         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1927                 rc = mls_convert_context(args->oldp, args->newp, c);
1928                 if (rc)
1929                         goto bad;
1930         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1931                 /*
1932                  * Switching between MLS and non-MLS policy:
1933                  * free any storage used by the MLS fields in the
1934                  * context for all existing entries in the sidtab.
1935                  */
1936                 mls_context_destroy(c);
1937         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1938                 /*
1939                  * Switching between non-MLS and MLS policy:
1940                  * ensure that the MLS fields of the context for all
1941                  * existing entries in the sidtab are filled in with a
1942                  * suitable default value, likely taken from one of the
1943                  * initial SIDs.
1944                  */
1945                 oc = args->newp->ocontexts[OCON_ISID];
1946                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1947                         oc = oc->next;
1948                 rc = -EINVAL;
1949                 if (!oc) {
1950                         printk(KERN_ERR "SELinux:  unable to look up"
1951                                 " the initial SIDs list\n");
1952                         goto bad;
1953                 }
1954                 range = &oc->context[0].range;
1955                 rc = mls_range_set(c, range);
1956                 if (rc)
1957                         goto bad;
1958         }
1959
1960         /* Check the validity of the new context. */
1961         if (!policydb_context_isvalid(args->newp, c)) {
1962                 rc = convert_context_handle_invalid_context(&oldc);
1963                 if (rc)
1964                         goto bad;
1965         }
1966
1967         context_destroy(&oldc);
1968
1969         rc = 0;
1970 out:
1971         return rc;
1972 bad:
1973         /* Map old representation to string and save it. */
1974         rc = context_struct_to_string(&oldc, &s, &len);
1975         if (rc)
1976                 return rc;
1977         context_destroy(&oldc);
1978         context_destroy(c);
1979         c->str = s;
1980         c->len = len;
1981         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1982                c->str);
1983         rc = 0;
1984         goto out;
1985 }
1986
1987 static void security_load_policycaps(void)
1988 {
1989         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1990                                                   POLICYDB_CAPABILITY_NETPEER);
1991         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1992                                                   POLICYDB_CAPABILITY_OPENPERM);
1993         selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps,
1994                                           POLICYDB_CAPABILITY_EXTSOCKCLASS);
1995         selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps,
1996                                                   POLICYDB_CAPABILITY_ALWAYSNETWORK);
1997         selinux_policycap_cgroupseclabel =
1998                 ebitmap_get_bit(&policydb.policycaps,
1999                                 POLICYDB_CAPABILITY_CGROUPSECLABEL);
2000 }
2001
2002 static int security_preserve_bools(struct policydb *p);
2003
2004 /**
2005  * security_load_policy - Load a security policy configuration.
2006  * @data: binary policy data
2007  * @len: length of data in bytes
2008  *
2009  * Load a new set of security policy configuration data,
2010  * validate it and convert the SID table as necessary.
2011  * This function will flush the access vector cache after
2012  * loading the new policy.
2013  */
2014 int security_load_policy(void *data, size_t len)
2015 {
2016         struct policydb *oldpolicydb, *newpolicydb;
2017         struct sidtab oldsidtab, newsidtab;
2018         struct selinux_mapping *oldmap, *map = NULL;
2019         struct convert_context_args args;
2020         u32 seqno;
2021         u16 map_size;
2022         int rc = 0;
2023         struct policy_file file = { data, len }, *fp = &file;
2024
2025         oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL);
2026         if (!oldpolicydb) {
2027                 rc = -ENOMEM;
2028                 goto out;
2029         }
2030         newpolicydb = oldpolicydb + 1;
2031
2032         if (!ss_initialized) {
2033                 avtab_cache_init();
2034                 rc = policydb_read(&policydb, fp);
2035                 if (rc) {
2036                         avtab_cache_destroy();
2037                         goto out;
2038                 }
2039
2040                 policydb.len = len;
2041                 rc = selinux_set_mapping(&policydb, secclass_map,
2042                                          &current_mapping,
2043                                          &current_mapping_size);
2044                 if (rc) {
2045                         policydb_destroy(&policydb);
2046                         avtab_cache_destroy();
2047                         goto out;
2048                 }
2049
2050                 rc = policydb_load_isids(&policydb, &sidtab);
2051                 if (rc) {
2052                         policydb_destroy(&policydb);
2053                         avtab_cache_destroy();
2054                         goto out;
2055                 }
2056
2057                 security_load_policycaps();
2058                 ss_initialized = 1;
2059                 seqno = ++latest_granting;
2060                 selinux_complete_init();
2061                 avc_ss_reset(seqno);
2062                 selnl_notify_policyload(seqno);
2063                 selinux_status_update_policyload(seqno);
2064                 selinux_netlbl_cache_invalidate();
2065                 selinux_xfrm_notify_policyload();
2066                 goto out;
2067         }
2068
2069 #if 0
2070         sidtab_hash_eval(&sidtab, "sids");
2071 #endif
2072
2073         rc = policydb_read(newpolicydb, fp);
2074         if (rc)
2075                 goto out;
2076
2077         newpolicydb->len = len;
2078         /* If switching between different policy types, log MLS status */
2079         if (policydb.mls_enabled && !newpolicydb->mls_enabled)
2080                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
2081         else if (!policydb.mls_enabled && newpolicydb->mls_enabled)
2082                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
2083
2084         rc = policydb_load_isids(newpolicydb, &newsidtab);
2085         if (rc) {
2086                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
2087                 policydb_destroy(newpolicydb);
2088                 goto out;
2089         }
2090
2091         rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size);
2092         if (rc)
2093                 goto err;
2094
2095         rc = security_preserve_bools(newpolicydb);
2096         if (rc) {
2097                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
2098                 goto err;
2099         }
2100
2101         /* Clone the SID table. */
2102         sidtab_shutdown(&sidtab);
2103
2104         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
2105         if (rc)
2106                 goto err;
2107
2108         /*
2109          * Convert the internal representations of contexts
2110          * in the new SID table.
2111          */
2112         args.oldp = &policydb;
2113         args.newp = newpolicydb;
2114         rc = sidtab_map(&newsidtab, convert_context, &args);
2115         if (rc) {
2116                 printk(KERN_ERR "SELinux:  unable to convert the internal"
2117                         " representation of contexts in the new SID"
2118                         " table\n");
2119                 goto err;
2120         }
2121
2122         /* Save the old policydb and SID table to free later. */
2123         memcpy(oldpolicydb, &policydb, sizeof(policydb));
2124         sidtab_set(&oldsidtab, &sidtab);
2125
2126         /* Install the new policydb and SID table. */
2127         write_lock_irq(&policy_rwlock);
2128         memcpy(&policydb, newpolicydb, sizeof(policydb));
2129         sidtab_set(&sidtab, &newsidtab);
2130         security_load_policycaps();
2131         oldmap = current_mapping;
2132         current_mapping = map;
2133         current_mapping_size = map_size;
2134         seqno = ++latest_granting;
2135         write_unlock_irq(&policy_rwlock);
2136
2137         /* Free the old policydb and SID table. */
2138         policydb_destroy(oldpolicydb);
2139         sidtab_destroy(&oldsidtab);
2140         kfree(oldmap);
2141
2142         avc_ss_reset(seqno);
2143         selnl_notify_policyload(seqno);
2144         selinux_status_update_policyload(seqno);
2145         selinux_netlbl_cache_invalidate();
2146         selinux_xfrm_notify_policyload();
2147
2148         rc = 0;
2149         goto out;
2150
2151 err:
2152         kfree(map);
2153         sidtab_destroy(&newsidtab);
2154         policydb_destroy(newpolicydb);
2155
2156 out:
2157         kfree(oldpolicydb);
2158         return rc;
2159 }
2160
2161 size_t security_policydb_len(void)
2162 {
2163         size_t len;
2164
2165         read_lock(&policy_rwlock);
2166         len = policydb.len;
2167         read_unlock(&policy_rwlock);
2168
2169         return len;
2170 }
2171
2172 /**
2173  * security_port_sid - Obtain the SID for a port.
2174  * @protocol: protocol number
2175  * @port: port number
2176  * @out_sid: security identifier
2177  */
2178 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
2179 {
2180         struct ocontext *c;
2181         int rc = 0;
2182
2183         read_lock(&policy_rwlock);
2184
2185         c = policydb.ocontexts[OCON_PORT];
2186         while (c) {
2187                 if (c->u.port.protocol == protocol &&
2188                     c->u.port.low_port <= port &&
2189                     c->u.port.high_port >= port)
2190                         break;
2191                 c = c->next;
2192         }
2193
2194         if (c) {
2195                 if (!c->sid[0]) {
2196                         rc = sidtab_context_to_sid(&sidtab,
2197                                                    &c->context[0],
2198                                                    &c->sid[0]);
2199                         if (rc)
2200                                 goto out;
2201                 }
2202                 *out_sid = c->sid[0];
2203         } else {
2204                 *out_sid = SECINITSID_PORT;
2205         }
2206
2207 out:
2208         read_unlock(&policy_rwlock);
2209         return rc;
2210 }
2211
2212 /**
2213  * security_netif_sid - Obtain the SID for a network interface.
2214  * @name: interface name
2215  * @if_sid: interface SID
2216  */
2217 int security_netif_sid(char *name, u32 *if_sid)
2218 {
2219         int rc = 0;
2220         struct ocontext *c;
2221
2222         read_lock(&policy_rwlock);
2223
2224         c = policydb.ocontexts[OCON_NETIF];
2225         while (c) {
2226                 if (strcmp(name, c->u.name) == 0)
2227                         break;
2228                 c = c->next;
2229         }
2230
2231         if (c) {
2232                 if (!c->sid[0] || !c->sid[1]) {
2233                         rc = sidtab_context_to_sid(&sidtab,
2234                                                   &c->context[0],
2235                                                   &c->sid[0]);
2236                         if (rc)
2237                                 goto out;
2238                         rc = sidtab_context_to_sid(&sidtab,
2239                                                    &c->context[1],
2240                                                    &c->sid[1]);
2241                         if (rc)
2242                                 goto out;
2243                 }
2244                 *if_sid = c->sid[0];
2245         } else
2246                 *if_sid = SECINITSID_NETIF;
2247
2248 out:
2249         read_unlock(&policy_rwlock);
2250         return rc;
2251 }
2252
2253 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2254 {
2255         int i, fail = 0;
2256
2257         for (i = 0; i < 4; i++)
2258                 if (addr[i] != (input[i] & mask[i])) {
2259                         fail = 1;
2260                         break;
2261                 }
2262
2263         return !fail;
2264 }
2265
2266 /**
2267  * security_node_sid - Obtain the SID for a node (host).
2268  * @domain: communication domain aka address family
2269  * @addrp: address
2270  * @addrlen: address length in bytes
2271  * @out_sid: security identifier
2272  */
2273 int security_node_sid(u16 domain,
2274                       void *addrp,
2275                       u32 addrlen,
2276                       u32 *out_sid)
2277 {
2278         int rc;
2279         struct ocontext *c;
2280
2281         read_lock(&policy_rwlock);
2282
2283         switch (domain) {
2284         case AF_INET: {
2285                 u32 addr;
2286
2287                 rc = -EINVAL;
2288                 if (addrlen != sizeof(u32))
2289                         goto out;
2290
2291                 addr = *((u32 *)addrp);
2292
2293                 c = policydb.ocontexts[OCON_NODE];
2294                 while (c) {
2295                         if (c->u.node.addr == (addr & c->u.node.mask))
2296                                 break;
2297                         c = c->next;
2298                 }
2299                 break;
2300         }
2301
2302         case AF_INET6:
2303                 rc = -EINVAL;
2304                 if (addrlen != sizeof(u64) * 2)
2305                         goto out;
2306                 c = policydb.ocontexts[OCON_NODE6];
2307                 while (c) {
2308                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2309                                                 c->u.node6.mask))
2310                                 break;
2311                         c = c->next;
2312                 }
2313                 break;
2314
2315         default:
2316                 rc = 0;
2317                 *out_sid = SECINITSID_NODE;
2318                 goto out;
2319         }
2320
2321         if (c) {
2322                 if (!c->sid[0]) {
2323                         rc = sidtab_context_to_sid(&sidtab,
2324                                                    &c->context[0],
2325                                                    &c->sid[0]);
2326                         if (rc)
2327                                 goto out;
2328                 }
2329                 *out_sid = c->sid[0];
2330         } else {
2331                 *out_sid = SECINITSID_NODE;
2332         }
2333
2334         rc = 0;
2335 out:
2336         read_unlock(&policy_rwlock);
2337         return rc;
2338 }
2339
2340 #define SIDS_NEL 25
2341
2342 /**
2343  * security_get_user_sids - Obtain reachable SIDs for a user.
2344  * @fromsid: starting SID
2345  * @username: username
2346  * @sids: array of reachable SIDs for user
2347  * @nel: number of elements in @sids
2348  *
2349  * Generate the set of SIDs for legal security contexts
2350  * for a given user that can be reached by @fromsid.
2351  * Set *@sids to point to a dynamically allocated
2352  * array containing the set of SIDs.  Set *@nel to the
2353  * number of elements in the array.
2354  */
2355
2356 int security_get_user_sids(u32 fromsid,
2357                            char *username,
2358                            u32 **sids,
2359                            u32 *nel)
2360 {
2361         struct context *fromcon, usercon;
2362         u32 *mysids = NULL, *mysids2, sid;
2363         u32 mynel = 0, maxnel = SIDS_NEL;
2364         struct user_datum *user;
2365         struct role_datum *role;
2366         struct ebitmap_node *rnode, *tnode;
2367         int rc = 0, i, j;
2368
2369         *sids = NULL;
2370         *nel = 0;
2371
2372         if (!ss_initialized)
2373                 goto out;
2374
2375         read_lock(&policy_rwlock);
2376
2377         context_init(&usercon);
2378
2379         rc = -EINVAL;
2380         fromcon = sidtab_search(&sidtab, fromsid);
2381         if (!fromcon)
2382                 goto out_unlock;
2383
2384         rc = -EINVAL;
2385         user = hashtab_search(policydb.p_users.table, username);
2386         if (!user)
2387                 goto out_unlock;
2388
2389         usercon.user = user->value;
2390
2391         rc = -ENOMEM;
2392         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2393         if (!mysids)
2394                 goto out_unlock;
2395
2396         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2397                 role = policydb.role_val_to_struct[i];
2398                 usercon.role = i + 1;
2399                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2400                         usercon.type = j + 1;
2401
2402                         if (mls_setup_user_range(fromcon, user, &usercon))
2403                                 continue;
2404
2405                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2406                         if (rc)
2407                                 goto out_unlock;
2408                         if (mynel < maxnel) {
2409                                 mysids[mynel++] = sid;
2410                         } else {
2411                                 rc = -ENOMEM;
2412                                 maxnel += SIDS_NEL;
2413                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2414                                 if (!mysids2)
2415                                         goto out_unlock;
2416                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2417                                 kfree(mysids);
2418                                 mysids = mysids2;
2419                                 mysids[mynel++] = sid;
2420                         }
2421                 }
2422         }
2423         rc = 0;
2424 out_unlock:
2425         read_unlock(&policy_rwlock);
2426         if (rc || !mynel) {
2427                 kfree(mysids);
2428                 goto out;
2429         }
2430
2431         rc = -ENOMEM;
2432         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2433         if (!mysids2) {
2434                 kfree(mysids);
2435                 goto out;
2436         }
2437         for (i = 0, j = 0; i < mynel; i++) {
2438                 struct av_decision dummy_avd;
2439                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2440                                           SECCLASS_PROCESS, /* kernel value */
2441                                           PROCESS__TRANSITION, AVC_STRICT,
2442                                           &dummy_avd);
2443                 if (!rc)
2444                         mysids2[j++] = mysids[i];
2445                 cond_resched();
2446         }
2447         rc = 0;
2448         kfree(mysids);
2449         *sids = mysids2;
2450         *nel = j;
2451 out:
2452         return rc;
2453 }
2454
2455 /**
2456  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2457  * @fstype: filesystem type
2458  * @path: path from root of mount
2459  * @sclass: file security class
2460  * @sid: SID for path
2461  *
2462  * Obtain a SID to use for a file in a filesystem that
2463  * cannot support xattr or use a fixed labeling behavior like
2464  * transition SIDs or task SIDs.
2465  *
2466  * The caller must acquire the policy_rwlock before calling this function.
2467  */
2468 static inline int __security_genfs_sid(const char *fstype,
2469                                        char *path,
2470                                        u16 orig_sclass,
2471                                        u32 *sid)
2472 {
2473         int len;
2474         u16 sclass;
2475         struct genfs *genfs;
2476         struct ocontext *c;
2477         int rc, cmp = 0;
2478
2479         while (path[0] == '/' && path[1] == '/')
2480                 path++;
2481
2482         sclass = unmap_class(orig_sclass);
2483         *sid = SECINITSID_UNLABELED;
2484
2485         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2486                 cmp = strcmp(fstype, genfs->fstype);
2487                 if (cmp <= 0)
2488                         break;
2489         }
2490
2491         rc = -ENOENT;
2492         if (!genfs || cmp)
2493                 goto out;
2494
2495         for (c = genfs->head; c; c = c->next) {
2496                 len = strlen(c->u.name);
2497                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2498                     (strncmp(c->u.name, path, len) == 0))
2499                         break;
2500         }
2501
2502         rc = -ENOENT;
2503         if (!c)
2504                 goto out;
2505
2506         if (!c->sid[0]) {
2507                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2508                 if (rc)
2509                         goto out;
2510         }
2511
2512         *sid = c->sid[0];
2513         rc = 0;
2514 out:
2515         return rc;
2516 }
2517
2518 /**
2519  * security_genfs_sid - Obtain a SID for a file in a filesystem
2520  * @fstype: filesystem type
2521  * @path: path from root of mount
2522  * @sclass: file security class
2523  * @sid: SID for path
2524  *
2525  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2526  * it afterward.
2527  */
2528 int security_genfs_sid(const char *fstype,
2529                        char *path,
2530                        u16 orig_sclass,
2531                        u32 *sid)
2532 {
2533         int retval;
2534
2535         read_lock(&policy_rwlock);
2536         retval = __security_genfs_sid(fstype, path, orig_sclass, sid);
2537         read_unlock(&policy_rwlock);
2538         return retval;
2539 }
2540
2541 /**
2542  * security_fs_use - Determine how to handle labeling for a filesystem.
2543  * @sb: superblock in question
2544  */
2545 int security_fs_use(struct super_block *sb)
2546 {
2547         int rc = 0;
2548         struct ocontext *c;
2549         struct superblock_security_struct *sbsec = sb->s_security;
2550         const char *fstype = sb->s_type->name;
2551
2552         read_lock(&policy_rwlock);
2553
2554         c = policydb.ocontexts[OCON_FSUSE];
2555         while (c) {
2556                 if (strcmp(fstype, c->u.name) == 0)
2557                         break;
2558                 c = c->next;
2559         }
2560
2561         if (c) {
2562                 sbsec->behavior = c->v.behavior;
2563                 if (!c->sid[0]) {
2564                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2565                                                    &c->sid[0]);
2566                         if (rc)
2567                                 goto out;
2568                 }
2569                 sbsec->sid = c->sid[0];
2570         } else {
2571                 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR,
2572                                           &sbsec->sid);
2573                 if (rc) {
2574                         sbsec->behavior = SECURITY_FS_USE_NONE;
2575                         rc = 0;
2576                 } else {
2577                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2578                 }
2579         }
2580
2581 out:
2582         read_unlock(&policy_rwlock);
2583         return rc;
2584 }
2585
2586 int security_get_bools(int *len, char ***names, int **values)
2587 {
2588         int i, rc;
2589
2590         read_lock(&policy_rwlock);
2591         *names = NULL;
2592         *values = NULL;
2593
2594         rc = 0;
2595         *len = policydb.p_bools.nprim;
2596         if (!*len)
2597                 goto out;
2598
2599         rc = -ENOMEM;
2600         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2601         if (!*names)
2602                 goto err;
2603
2604         rc = -ENOMEM;
2605         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2606         if (!*values)
2607                 goto err;
2608
2609         for (i = 0; i < *len; i++) {
2610                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2611
2612                 rc = -ENOMEM;
2613                 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC);
2614                 if (!(*names)[i])
2615                         goto err;
2616         }
2617         rc = 0;
2618 out:
2619         read_unlock(&policy_rwlock);
2620         return rc;
2621 err:
2622         if (*names) {
2623                 for (i = 0; i < *len; i++)
2624                         kfree((*names)[i]);
2625         }
2626         kfree(*values);
2627         goto out;
2628 }
2629
2630
2631 int security_set_bools(int len, int *values)
2632 {
2633         int i, rc;
2634         int lenp, seqno = 0;
2635         struct cond_node *cur;
2636
2637         write_lock_irq(&policy_rwlock);
2638
2639         rc = -EFAULT;
2640         lenp = policydb.p_bools.nprim;
2641         if (len != lenp)
2642                 goto out;
2643
2644         for (i = 0; i < len; i++) {
2645                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2646                         audit_log(current->audit_context, GFP_ATOMIC,
2647                                 AUDIT_MAC_CONFIG_CHANGE,
2648                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2649                                 sym_name(&policydb, SYM_BOOLS, i),
2650                                 !!values[i],
2651                                 policydb.bool_val_to_struct[i]->state,
2652                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2653                                 audit_get_sessionid(current));
2654                 }
2655                 if (values[i])
2656                         policydb.bool_val_to_struct[i]->state = 1;
2657                 else
2658                         policydb.bool_val_to_struct[i]->state = 0;
2659         }
2660
2661         for (cur = policydb.cond_list; cur; cur = cur->next) {
2662                 rc = evaluate_cond_node(&policydb, cur);
2663                 if (rc)
2664                         goto out;
2665         }
2666
2667         seqno = ++latest_granting;
2668         rc = 0;
2669 out:
2670         write_unlock_irq(&policy_rwlock);
2671         if (!rc) {
2672                 avc_ss_reset(seqno);
2673                 selnl_notify_policyload(seqno);
2674                 selinux_status_update_policyload(seqno);
2675                 selinux_xfrm_notify_policyload();
2676         }
2677         return rc;
2678 }
2679
2680 int security_get_bool_value(int index)
2681 {
2682         int rc;
2683         int len;
2684
2685         read_lock(&policy_rwlock);
2686
2687         rc = -EFAULT;
2688         len = policydb.p_bools.nprim;
2689         if (index >= len)
2690                 goto out;
2691
2692         rc = policydb.bool_val_to_struct[index]->state;
2693 out:
2694         read_unlock(&policy_rwlock);
2695         return rc;
2696 }
2697
2698 static int security_preserve_bools(struct policydb *p)
2699 {
2700         int rc, nbools = 0, *bvalues = NULL, i;
2701         char **bnames = NULL;
2702         struct cond_bool_datum *booldatum;
2703         struct cond_node *cur;
2704
2705         rc = security_get_bools(&nbools, &bnames, &bvalues);
2706         if (rc)
2707                 goto out;
2708         for (i = 0; i < nbools; i++) {
2709                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2710                 if (booldatum)
2711                         booldatum->state = bvalues[i];
2712         }
2713         for (cur = p->cond_list; cur; cur = cur->next) {
2714                 rc = evaluate_cond_node(p, cur);
2715                 if (rc)
2716                         goto out;
2717         }
2718
2719 out:
2720         if (bnames) {
2721                 for (i = 0; i < nbools; i++)
2722                         kfree(bnames[i]);
2723         }
2724         kfree(bnames);
2725         kfree(bvalues);
2726         return rc;
2727 }
2728
2729 /*
2730  * security_sid_mls_copy() - computes a new sid based on the given
2731  * sid and the mls portion of mls_sid.
2732  */
2733 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2734 {
2735         struct context *context1;
2736         struct context *context2;
2737         struct context newcon;
2738         char *s;
2739         u32 len;
2740         int rc;
2741
2742         rc = 0;
2743         if (!ss_initialized || !policydb.mls_enabled) {
2744                 *new_sid = sid;
2745                 goto out;
2746         }
2747
2748         context_init(&newcon);
2749
2750         read_lock(&policy_rwlock);
2751
2752         rc = -EINVAL;
2753         context1 = sidtab_search(&sidtab, sid);
2754         if (!context1) {
2755                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2756                         __func__, sid);
2757                 goto out_unlock;
2758         }
2759
2760         rc = -EINVAL;
2761         context2 = sidtab_search(&sidtab, mls_sid);
2762         if (!context2) {
2763                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2764                         __func__, mls_sid);
2765                 goto out_unlock;
2766         }
2767
2768         newcon.user = context1->user;
2769         newcon.role = context1->role;
2770         newcon.type = context1->type;
2771         rc = mls_context_cpy(&newcon, context2);
2772         if (rc)
2773                 goto out_unlock;
2774
2775         /* Check the validity of the new context. */
2776         if (!policydb_context_isvalid(&policydb, &newcon)) {
2777                 rc = convert_context_handle_invalid_context(&newcon);
2778                 if (rc) {
2779                         if (!context_struct_to_string(&newcon, &s, &len)) {
2780                                 audit_log(current->audit_context,
2781                                           GFP_ATOMIC, AUDIT_SELINUX_ERR,
2782                                           "op=security_sid_mls_copy "
2783                                           "invalid_context=%s", s);
2784                                 kfree(s);
2785                         }
2786                         goto out_unlock;
2787                 }
2788         }
2789
2790         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2791 out_unlock:
2792         read_unlock(&policy_rwlock);
2793         context_destroy(&newcon);
2794 out:
2795         return rc;
2796 }
2797
2798 /**
2799  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2800  * @nlbl_sid: NetLabel SID
2801  * @nlbl_type: NetLabel labeling protocol type
2802  * @xfrm_sid: XFRM SID
2803  *
2804  * Description:
2805  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2806  * resolved into a single SID it is returned via @peer_sid and the function
2807  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2808  * returns a negative value.  A table summarizing the behavior is below:
2809  *
2810  *                                 | function return |      @sid
2811  *   ------------------------------+-----------------+-----------------
2812  *   no peer labels                |        0        |    SECSID_NULL
2813  *   single peer label             |        0        |    <peer_label>
2814  *   multiple, consistent labels   |        0        |    <peer_label>
2815  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2816  *
2817  */
2818 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2819                                  u32 xfrm_sid,
2820                                  u32 *peer_sid)
2821 {
2822         int rc;
2823         struct context *nlbl_ctx;
2824         struct context *xfrm_ctx;
2825
2826         *peer_sid = SECSID_NULL;
2827
2828         /* handle the common (which also happens to be the set of easy) cases
2829          * right away, these two if statements catch everything involving a
2830          * single or absent peer SID/label */
2831         if (xfrm_sid == SECSID_NULL) {
2832                 *peer_sid = nlbl_sid;
2833                 return 0;
2834         }
2835         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2836          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2837          * is present */
2838         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2839                 *peer_sid = xfrm_sid;
2840                 return 0;
2841         }
2842
2843         /* we don't need to check ss_initialized here since the only way both
2844          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2845          * security server was initialized and ss_initialized was true */
2846         if (!policydb.mls_enabled)
2847                 return 0;
2848
2849         read_lock(&policy_rwlock);
2850
2851         rc = -EINVAL;
2852         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2853         if (!nlbl_ctx) {
2854                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2855                        __func__, nlbl_sid);
2856                 goto out;
2857         }
2858         rc = -EINVAL;
2859         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2860         if (!xfrm_ctx) {
2861                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2862                        __func__, xfrm_sid);
2863                 goto out;
2864         }
2865         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2866         if (rc)
2867                 goto out;
2868
2869         /* at present NetLabel SIDs/labels really only carry MLS
2870          * information so if the MLS portion of the NetLabel SID
2871          * matches the MLS portion of the labeled XFRM SID/label
2872          * then pass along the XFRM SID as it is the most
2873          * expressive */
2874         *peer_sid = xfrm_sid;
2875 out:
2876         read_unlock(&policy_rwlock);
2877         return rc;
2878 }
2879
2880 static int get_classes_callback(void *k, void *d, void *args)
2881 {
2882         struct class_datum *datum = d;
2883         char *name = k, **classes = args;
2884         int value = datum->value - 1;
2885
2886         classes[value] = kstrdup(name, GFP_ATOMIC);
2887         if (!classes[value])
2888                 return -ENOMEM;
2889
2890         return 0;
2891 }
2892
2893 int security_get_classes(char ***classes, int *nclasses)
2894 {
2895         int rc;
2896
2897         read_lock(&policy_rwlock);
2898
2899         rc = -ENOMEM;
2900         *nclasses = policydb.p_classes.nprim;
2901         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2902         if (!*classes)
2903                 goto out;
2904
2905         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2906                         *classes);
2907         if (rc) {
2908                 int i;
2909                 for (i = 0; i < *nclasses; i++)
2910                         kfree((*classes)[i]);
2911                 kfree(*classes);
2912         }
2913
2914 out:
2915         read_unlock(&policy_rwlock);
2916         return rc;
2917 }
2918
2919 static int get_permissions_callback(void *k, void *d, void *args)
2920 {
2921         struct perm_datum *datum = d;
2922         char *name = k, **perms = args;
2923         int value = datum->value - 1;
2924
2925         perms[value] = kstrdup(name, GFP_ATOMIC);
2926         if (!perms[value])
2927                 return -ENOMEM;
2928
2929         return 0;
2930 }
2931
2932 int security_get_permissions(char *class, char ***perms, int *nperms)
2933 {
2934         int rc, i;
2935         struct class_datum *match;
2936
2937         read_lock(&policy_rwlock);
2938
2939         rc = -EINVAL;
2940         match = hashtab_search(policydb.p_classes.table, class);
2941         if (!match) {
2942                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2943                         __func__, class);
2944                 goto out;
2945         }
2946
2947         rc = -ENOMEM;
2948         *nperms = match->permissions.nprim;
2949         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2950         if (!*perms)
2951                 goto out;
2952
2953         if (match->comdatum) {
2954                 rc = hashtab_map(match->comdatum->permissions.table,
2955                                 get_permissions_callback, *perms);
2956                 if (rc)
2957                         goto err;
2958         }
2959
2960         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2961                         *perms);
2962         if (rc)
2963                 goto err;
2964
2965 out:
2966         read_unlock(&policy_rwlock);
2967         return rc;
2968
2969 err:
2970         read_unlock(&policy_rwlock);
2971         for (i = 0; i < *nperms; i++)
2972                 kfree((*perms)[i]);
2973         kfree(*perms);
2974         return rc;
2975 }
2976
2977 int security_get_reject_unknown(void)
2978 {
2979         return policydb.reject_unknown;
2980 }
2981
2982 int security_get_allow_unknown(void)
2983 {
2984         return policydb.allow_unknown;
2985 }
2986
2987 /**
2988  * security_policycap_supported - Check for a specific policy capability
2989  * @req_cap: capability
2990  *
2991  * Description:
2992  * This function queries the currently loaded policy to see if it supports the
2993  * capability specified by @req_cap.  Returns true (1) if the capability is
2994  * supported, false (0) if it isn't supported.
2995  *
2996  */
2997 int security_policycap_supported(unsigned int req_cap)
2998 {
2999         int rc;
3000
3001         read_lock(&policy_rwlock);
3002         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
3003         read_unlock(&policy_rwlock);
3004
3005         return rc;
3006 }
3007
3008 struct selinux_audit_rule {
3009         u32 au_seqno;
3010         struct context au_ctxt;
3011 };
3012
3013 void selinux_audit_rule_free(void *vrule)
3014 {
3015         struct selinux_audit_rule *rule = vrule;
3016
3017         if (rule) {
3018                 context_destroy(&rule->au_ctxt);
3019                 kfree(rule);
3020         }
3021 }
3022
3023 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3024 {
3025         struct selinux_audit_rule *tmprule;
3026         struct role_datum *roledatum;
3027         struct type_datum *typedatum;
3028         struct user_datum *userdatum;
3029         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3030         int rc = 0;
3031
3032         *rule = NULL;
3033
3034         if (!ss_initialized)
3035                 return -EOPNOTSUPP;
3036
3037         switch (field) {
3038         case AUDIT_SUBJ_USER:
3039         case AUDIT_SUBJ_ROLE:
3040         case AUDIT_SUBJ_TYPE:
3041         case AUDIT_OBJ_USER:
3042         case AUDIT_OBJ_ROLE:
3043         case AUDIT_OBJ_TYPE:
3044                 /* only 'equals' and 'not equals' fit user, role, and type */
3045                 if (op != Audit_equal && op != Audit_not_equal)
3046                         return -EINVAL;
3047                 break;
3048         case AUDIT_SUBJ_SEN:
3049         case AUDIT_SUBJ_CLR:
3050         case AUDIT_OBJ_LEV_LOW:
3051         case AUDIT_OBJ_LEV_HIGH:
3052                 /* we do not allow a range, indicated by the presence of '-' */
3053                 if (strchr(rulestr, '-'))
3054                         return -EINVAL;
3055                 break;
3056         default:
3057                 /* only the above fields are valid */
3058                 return -EINVAL;
3059         }
3060
3061         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3062         if (!tmprule)
3063                 return -ENOMEM;
3064
3065         context_init(&tmprule->au_ctxt);
3066
3067         read_lock(&policy_rwlock);
3068
3069         tmprule->au_seqno = latest_granting;
3070
3071         switch (field) {
3072         case AUDIT_SUBJ_USER:
3073         case AUDIT_OBJ_USER:
3074                 rc = -EINVAL;
3075                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
3076                 if (!userdatum)
3077                         goto out;
3078                 tmprule->au_ctxt.user = userdatum->value;
3079                 break;
3080         case AUDIT_SUBJ_ROLE:
3081         case AUDIT_OBJ_ROLE:
3082                 rc = -EINVAL;
3083                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
3084                 if (!roledatum)
3085                         goto out;
3086                 tmprule->au_ctxt.role = roledatum->value;
3087                 break;
3088         case AUDIT_SUBJ_TYPE:
3089         case AUDIT_OBJ_TYPE:
3090                 rc = -EINVAL;
3091                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
3092                 if (!typedatum)
3093                         goto out;
3094                 tmprule->au_ctxt.type = typedatum->value;
3095                 break;
3096         case AUDIT_SUBJ_SEN:
3097         case AUDIT_SUBJ_CLR:
3098         case AUDIT_OBJ_LEV_LOW:
3099         case AUDIT_OBJ_LEV_HIGH:
3100                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
3101                 if (rc)
3102                         goto out;
3103                 break;
3104         }
3105         rc = 0;
3106 out:
3107         read_unlock(&policy_rwlock);
3108
3109         if (rc) {
3110                 selinux_audit_rule_free(tmprule);
3111                 tmprule = NULL;
3112         }
3113
3114         *rule = tmprule;
3115
3116         return rc;
3117 }
3118
3119 /* Check to see if the rule contains any selinux fields */
3120 int selinux_audit_rule_known(struct audit_krule *rule)
3121 {
3122         int i;
3123
3124         for (i = 0; i < rule->field_count; i++) {
3125                 struct audit_field *f = &rule->fields[i];
3126                 switch (f->type) {
3127                 case AUDIT_SUBJ_USER:
3128                 case AUDIT_SUBJ_ROLE:
3129                 case AUDIT_SUBJ_TYPE:
3130                 case AUDIT_SUBJ_SEN:
3131                 case AUDIT_SUBJ_CLR:
3132                 case AUDIT_OBJ_USER:
3133                 case AUDIT_OBJ_ROLE:
3134                 case AUDIT_OBJ_TYPE:
3135                 case AUDIT_OBJ_LEV_LOW:
3136                 case AUDIT_OBJ_LEV_HIGH:
3137                         return 1;
3138                 }
3139         }
3140
3141         return 0;
3142 }
3143
3144 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
3145                              struct audit_context *actx)
3146 {
3147         struct context *ctxt;
3148         struct mls_level *level;
3149         struct selinux_audit_rule *rule = vrule;
3150         int match = 0;
3151
3152         if (unlikely(!rule)) {
3153                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3154                 return -ENOENT;
3155         }
3156
3157         read_lock(&policy_rwlock);
3158
3159         if (rule->au_seqno < latest_granting) {
3160                 match = -ESTALE;
3161                 goto out;
3162         }
3163
3164         ctxt = sidtab_search(&sidtab, sid);
3165         if (unlikely(!ctxt)) {
3166                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3167                           sid);
3168                 match = -ENOENT;
3169                 goto out;
3170         }
3171
3172         /* a field/op pair that is not caught here will simply fall through
3173            without a match */
3174         switch (field) {
3175         case AUDIT_SUBJ_USER:
3176         case AUDIT_OBJ_USER:
3177                 switch (op) {
3178                 case Audit_equal:
3179                         match = (ctxt->user == rule->au_ctxt.user);
3180                         break;
3181                 case Audit_not_equal:
3182                         match = (ctxt->user != rule->au_ctxt.user);
3183                         break;
3184                 }
3185                 break;
3186         case AUDIT_SUBJ_ROLE:
3187         case AUDIT_OBJ_ROLE:
3188                 switch (op) {
3189                 case Audit_equal:
3190                         match = (ctxt->role == rule->au_ctxt.role);
3191                         break;
3192                 case Audit_not_equal:
3193                         match = (ctxt->role != rule->au_ctxt.role);
3194                         break;
3195                 }
3196                 break;
3197         case AUDIT_SUBJ_TYPE:
3198         case AUDIT_OBJ_TYPE:
3199                 switch (op) {
3200                 case Audit_equal:
3201                         match = (ctxt->type == rule->au_ctxt.type);
3202                         break;
3203                 case Audit_not_equal:
3204                         match = (ctxt->type != rule->au_ctxt.type);
3205                         break;
3206                 }
3207                 break;
3208         case AUDIT_SUBJ_SEN:
3209         case AUDIT_SUBJ_CLR:
3210         case AUDIT_OBJ_LEV_LOW:
3211         case AUDIT_OBJ_LEV_HIGH:
3212                 level = ((field == AUDIT_SUBJ_SEN ||
3213                           field == AUDIT_OBJ_LEV_LOW) ?
3214                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3215                 switch (op) {
3216                 case Audit_equal:
3217                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3218                                              level);
3219                         break;
3220                 case Audit_not_equal:
3221                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3222                                               level);
3223                         break;
3224                 case Audit_lt:
3225                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3226                                                level) &&
3227                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3228                                                level));
3229                         break;
3230                 case Audit_le:
3231                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3232                                               level);
3233                         break;
3234                 case Audit_gt:
3235                         match = (mls_level_dom(level,
3236                                               &rule->au_ctxt.range.level[0]) &&
3237                                  !mls_level_eq(level,
3238                                                &rule->au_ctxt.range.level[0]));
3239                         break;
3240                 case Audit_ge:
3241                         match = mls_level_dom(level,
3242                                               &rule->au_ctxt.range.level[0]);
3243                         break;
3244                 }
3245         }
3246
3247 out:
3248         read_unlock(&policy_rwlock);
3249         return match;
3250 }
3251
3252 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3253
3254 static int aurule_avc_callback(u32 event)
3255 {
3256         int err = 0;
3257
3258         if (event == AVC_CALLBACK_RESET && aurule_callback)
3259                 err = aurule_callback();
3260         return err;
3261 }
3262
3263 static int __init aurule_init(void)
3264 {
3265         int err;
3266
3267         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3268         if (err)
3269                 panic("avc_add_callback() failed, error %d\n", err);
3270
3271         return err;
3272 }
3273 __initcall(aurule_init);
3274
3275 #ifdef CONFIG_NETLABEL
3276 /**
3277  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3278  * @secattr: the NetLabel packet security attributes
3279  * @sid: the SELinux SID
3280  *
3281  * Description:
3282  * Attempt to cache the context in @ctx, which was derived from the packet in
3283  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3284  * already been initialized.
3285  *
3286  */
3287 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3288                                       u32 sid)
3289 {
3290         u32 *sid_cache;
3291
3292         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3293         if (sid_cache == NULL)
3294                 return;
3295         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3296         if (secattr->cache == NULL) {
3297                 kfree(sid_cache);
3298                 return;
3299         }
3300
3301         *sid_cache = sid;
3302         secattr->cache->free = kfree;
3303         secattr->cache->data = sid_cache;
3304         secattr->flags |= NETLBL_SECATTR_CACHE;
3305 }
3306
3307 /**
3308  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3309  * @secattr: the NetLabel packet security attributes
3310  * @sid: the SELinux SID
3311  *
3312  * Description:
3313  * Convert the given NetLabel security attributes in @secattr into a
3314  * SELinux SID.  If the @secattr field does not contain a full SELinux
3315  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3316  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3317  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3318  * conversion for future lookups.  Returns zero on success, negative values on
3319  * failure.
3320  *
3321  */
3322 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3323                                    u32 *sid)
3324 {
3325         int rc;
3326         struct context *ctx;
3327         struct context ctx_new;
3328
3329         if (!ss_initialized) {
3330                 *sid = SECSID_NULL;
3331                 return 0;
3332         }
3333
3334         read_lock(&policy_rwlock);
3335
3336         if (secattr->flags & NETLBL_SECATTR_CACHE)
3337                 *sid = *(u32 *)secattr->cache->data;
3338         else if (secattr->flags & NETLBL_SECATTR_SECID)
3339                 *sid = secattr->attr.secid;
3340         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3341                 rc = -EIDRM;
3342                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3343                 if (ctx == NULL)
3344                         goto out;
3345
3346                 context_init(&ctx_new);
3347                 ctx_new.user = ctx->user;
3348                 ctx_new.role = ctx->role;
3349                 ctx_new.type = ctx->type;
3350                 mls_import_netlbl_lvl(&ctx_new, secattr);
3351                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3352                         rc = mls_import_netlbl_cat(&ctx_new, secattr);
3353                         if (rc)
3354                                 goto out;
3355                 }
3356                 rc = -EIDRM;
3357                 if (!mls_context_isvalid(&policydb, &ctx_new))
3358                         goto out_free;
3359
3360                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3361                 if (rc)
3362                         goto out_free;
3363
3364                 security_netlbl_cache_add(secattr, *sid);
3365
3366                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3367         } else
3368                 *sid = SECSID_NULL;
3369
3370         read_unlock(&policy_rwlock);
3371         return 0;
3372 out_free:
3373         ebitmap_destroy(&ctx_new.range.level[0].cat);
3374 out:
3375         read_unlock(&policy_rwlock);
3376         return rc;
3377 }
3378
3379 /**
3380  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3381  * @sid: the SELinux SID
3382  * @secattr: the NetLabel packet security attributes
3383  *
3384  * Description:
3385  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3386  * Returns zero on success, negative values on failure.
3387  *
3388  */
3389 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3390 {
3391         int rc;
3392         struct context *ctx;
3393
3394         if (!ss_initialized)
3395                 return 0;
3396
3397         read_lock(&policy_rwlock);
3398
3399         rc = -ENOENT;
3400         ctx = sidtab_search(&sidtab, sid);
3401         if (ctx == NULL)
3402                 goto out;
3403
3404         rc = -ENOMEM;
3405         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3406                                   GFP_ATOMIC);
3407         if (secattr->domain == NULL)
3408                 goto out;
3409
3410         secattr->attr.secid = sid;
3411         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3412         mls_export_netlbl_lvl(ctx, secattr);
3413         rc = mls_export_netlbl_cat(ctx, secattr);
3414 out:
3415         read_unlock(&policy_rwlock);
3416         return rc;
3417 }
3418 #endif /* CONFIG_NETLABEL */
3419
3420 /**
3421  * security_read_policy - read the policy.
3422  * @data: binary policy data
3423  * @len: length of data in bytes
3424  *
3425  */
3426 int security_read_policy(void **data, size_t *len)
3427 {
3428         int rc;
3429         struct policy_file fp;
3430
3431         if (!ss_initialized)
3432                 return -EINVAL;
3433
3434         *len = security_policydb_len();
3435
3436         *data = vmalloc_user(*len);
3437         if (!*data)
3438                 return -ENOMEM;
3439
3440         fp.data = *data;
3441         fp.len = *len;
3442
3443         read_lock(&policy_rwlock);
3444         rc = policydb_write(&policydb, &fp);
3445         read_unlock(&policy_rwlock);
3446
3447         if (rc)
3448                 return rc;
3449
3450         *len = (unsigned long)fp.data - (unsigned long)*data;
3451         return 0;
3452
3453 }