Pileus Git - ~andy/linux/blob - security/selinux/ss/services.c

   1 /*
   2  * Implementation of the security services.
   3  *
   4  * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   5  *           James Morris <jmorris@redhat.com>
   6  *
   7  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8  *
   9  *      Support for enhanced MLS infrastructure.
  10  *      Support for context based audit filters.
  11  *
  12  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  13  *
  14  *      Added conditional policy language extensions
  15  *
  16  * Updated: Hewlett-Packard <paul@paul-moore.com>
  17  *
  18  *      Added support for NetLabel
  19  *      Added support for the policy capability bitmap
  20  *
  21  * Updated: Chad Sellers <csellers@tresys.com>
  22  *
  23  *  Added validation of kernel classes and permissions
  24  *
  25  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  26  *
  27  *  Added support for bounds domain and audit messaged on masked permissions
  28  *
  29  * Updated: Guido Trentalancia <guido@trentalancia.com>
  30  *
  31  *  Added support for runtime switching of the policy type
  32  *
  33  * Copyright (C) 2008, 2009 NEC Corporation
  34  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  35  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  36  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  37  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  38  *      This program is free software; you can redistribute it and/or modify
  39  *      it under the terms of the GNU General Public License as published by
  40  *      the Free Software Foundation, version 2.
  41  */
  42 #include <linux/kernel.h>
  43 #include <linux/slab.h>
  44 #include <linux/string.h>
  45 #include <linux/spinlock.h>
  46 #include <linux/rcupdate.h>
  47 #include <linux/errno.h>
  48 #include <linux/in.h>
  49 #include <linux/sched.h>
  50 #include <linux/audit.h>
  51 #include <linux/mutex.h>
  52 #include <linux/selinux.h>
  53 #include <linux/flex_array.h>
  54 #include <linux/vmalloc.h>
  55 #include <net/netlabel.h>
  56
  57 #include "flask.h"
  58 #include "avc.h"
  59 #include "avc_ss.h"
  60 #include "security.h"
  61 #include "context.h"
  62 #include "policydb.h"
  63 #include "sidtab.h"
  64 #include "services.h"
  65 #include "conditional.h"
  66 #include "mls.h"
  67 #include "objsec.h"
  68 #include "netlabel.h"
  69 #include "xfrm.h"
  70 #include "ebitmap.h"
  71 #include "audit.h"
  72
  73 int selinux_policycap_netpeer;
  74 int selinux_policycap_openperm;
  75
  76 static DEFINE_RWLOCK(policy_rwlock);
  77
  78 static struct sidtab sidtab;
  79 struct policydb policydb;
  80 int ss_initialized;
  81
  82 /*
  83  * The largest sequence number that has been used when
  84  * providing an access decision to the access vector cache.
  85  * The sequence number only changes when a policy change
  86  * occurs.
  87  */
  88 static u32 latest_granting;
  89
  90 /* Forward declaration. */
  91 static int context_struct_to_string(struct context *context, char **scontext,
  92                                     u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct context *scontext,
  95                                       struct context *tcontext,
  96                                       u16 tclass,
  97                                       struct av_decision *avd);
  98
  99 struct selinux_mapping {
 100         u16 value; /* policy value */
 101         unsigned num_perms;
 102         u32 perms[sizeof(u32) * 8];
 103 };
 104
 105 static struct selinux_mapping *current_mapping;
 106 static u16 current_mapping_size;
 107
 108 static int selinux_set_mapping(struct policydb *pol,
 109                                struct security_class_mapping *map,
 110                                struct selinux_mapping **out_map_p,
 111                                u16 *out_map_size)
 112 {
 113         struct selinux_mapping *out_map = NULL;
 114         size_t size = sizeof(struct selinux_mapping);
 115         u16 i, j;
 116         unsigned k;
 117         bool print_unknown_handle = false;
 118
 119         /* Find number of classes in the input mapping */
 120         if (!map)
 121                 return -EINVAL;
 122         i = 0;
 123         while (map[i].name)
 124                 i++;
 125
 126         /* Allocate space for the class records, plus one for class zero */
 127         out_map = kcalloc(++i, size, GFP_ATOMIC);
 128         if (!out_map)
 129                 return -ENOMEM;
 130
 131         /* Store the raw class and permission values */
 132         j = 0;
 133         while (map[j].name) {
 134                 struct security_class_mapping *p_in = map + (j++);
 135                 struct selinux_mapping *p_out = out_map + j;
 136
 137                 /* An empty class string skips ahead */
 138                 if (!strcmp(p_in->name, "")) {
 139                         p_out->num_perms = 0;
 140                         continue;
 141                 }
 142
 143                 p_out->value = string_to_security_class(pol, p_in->name);
 144                 if (!p_out->value) {
 145                         printk(KERN_INFO
 146                                "SELinux:  Class %s not defined in policy.\n",
 147                                p_in->name);
 148                         if (pol->reject_unknown)
 149                                 goto err;
 150                         p_out->num_perms = 0;
 151                         print_unknown_handle = true;
 152                         continue;
 153                 }
 154
 155                 k = 0;
 156                 while (p_in->perms && p_in->perms[k]) {
 157                         /* An empty permission string skips ahead */
 158                         if (!*p_in->perms[k]) {
 159                                 k++;
 160                                 continue;
 161                         }
 162                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 163                                                             p_in->perms[k]);
 164                         if (!p_out->perms[k]) {
 165                                 printk(KERN_INFO
 166                                        "SELinux:  Permission %s in class %s not defined in policy.\n",
 167                                        p_in->perms[k], p_in->name);
 168                                 if (pol->reject_unknown)
 169                                         goto err;
 170                                 print_unknown_handle = true;
 171                         }
 172
 173                         k++;
 174                 }
 175                 p_out->num_perms = k;
 176         }
 177
 178         if (print_unknown_handle)
 179                 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n",
 180                        pol->allow_unknown ? "allowed" : "denied");
 181
 182         *out_map_p = out_map;
 183         *out_map_size = i;
 184         return 0;
 185 err:
 186         kfree(out_map);
 187         return -EINVAL;
 188 }
 189
 190 /*
 191  * Get real, policy values from mapped values
 192  */
 193
 194 static u16 unmap_class(u16 tclass)
 195 {
 196         if (tclass < current_mapping_size)
 197                 return current_mapping[tclass].value;
 198
 199         return tclass;
 200 }
 201
 202 /*
 203  * Get kernel value for class from its policy value
 204  */
 205 static u16 map_class(u16 pol_value)
 206 {
 207         u16 i;
 208
 209         for (i = 1; i < current_mapping_size; i++) {
 210                 if (current_mapping[i].value == pol_value)
 211                         return i;
 212         }
 213
 214         return SECCLASS_NULL;
 215 }
 216
 217 static void map_decision(u16 tclass, struct av_decision *avd,
 218                          int allow_unknown)
 219 {
 220         if (tclass < current_mapping_size) {
 221                 unsigned i, n = current_mapping[tclass].num_perms;
 222                 u32 result;
 223
 224                 for (i = 0, result = 0; i < n; i++) {
 225                         if (avd->allowed & current_mapping[tclass].perms[i])
 226                                 result |= 1<<i;
 227                         if (allow_unknown && !current_mapping[tclass].perms[i])
 228                                 result |= 1<<i;
 229                 }
 230                 avd->allowed = result;
 231
 232                 for (i = 0, result = 0; i < n; i++)
 233                         if (avd->auditallow & current_mapping[tclass].perms[i])
 234                                 result |= 1<<i;
 235                 avd->auditallow = result;
 236
 237                 for (i = 0, result = 0; i < n; i++) {
 238                         if (avd->auditdeny & current_mapping[tclass].perms[i])
 239                                 result |= 1<<i;
 240                         if (!allow_unknown && !current_mapping[tclass].perms[i])
 241                                 result |= 1<<i;
 242                 }
 243                 /*
 244                  * In case the kernel has a bug and requests a permission
 245                  * between num_perms and the maximum permission number, we
 246                  * should audit that denial
 247                  */
 248                 for (; i < (sizeof(u32)*8); i++)
 249                         result |= 1<<i;
 250                 avd->auditdeny = result;
 251         }
 252 }
 253
 254 int security_mls_enabled(void)
 255 {
 256         return policydb.mls_enabled;
 257 }
 258
 259 /*
 260  * Return the boolean value of a constraint expression
 261  * when it is applied to the specified source and target
 262  * security contexts.
 263  *
 264  * xcontext is a special beast...  It is used by the validatetrans rules
 265  * only.  For these rules, scontext is the context before the transition,
 266  * tcontext is the context after the transition, and xcontext is the context
 267  * of the process performing the transition.  All other callers of
 268  * constraint_expr_eval should pass in NULL for xcontext.
 269  */
 270 static int constraint_expr_eval(struct context *scontext,
 271                                 struct context *tcontext,
 272                                 struct context *xcontext,
 273                                 struct constraint_expr *cexpr)
 274 {
 275         u32 val1, val2;
 276         struct context *c;
 277         struct role_datum *r1, *r2;
 278         struct mls_level *l1, *l2;
 279         struct constraint_expr *e;
 280         int s[CEXPR_MAXDEPTH];
 281         int sp = -1;
 282
 283         for (e = cexpr; e; e = e->next) {
 284                 switch (e->expr_type) {
 285                 case CEXPR_NOT:
 286                         BUG_ON(sp < 0);
 287                         s[sp] = !s[sp];
 288                         break;
 289                 case CEXPR_AND:
 290                         BUG_ON(sp < 1);
 291                         sp--;
 292                         s[sp] &= s[sp + 1];
 293                         break;
 294                 case CEXPR_OR:
 295                         BUG_ON(sp < 1);
 296                         sp--;
 297                         s[sp] |= s[sp + 1];
 298                         break;
 299                 case CEXPR_ATTR:
 300                         if (sp == (CEXPR_MAXDEPTH - 1))
 301                                 return 0;
 302                         switch (e->attr) {
 303                         case CEXPR_USER:
 304                                 val1 = scontext->user;
 305                                 val2 = tcontext->user;
 306                                 break;
 307                         case CEXPR_TYPE:
 308                                 val1 = scontext->type;
 309                                 val2 = tcontext->type;
 310                                 break;
 311                         case CEXPR_ROLE:
 312                                 val1 = scontext->role;
 313                                 val2 = tcontext->role;
 314                                 r1 = policydb.role_val_to_struct[val1 - 1];
 315                                 r2 = policydb.role_val_to_struct[val2 - 1];
 316                                 switch (e->op) {
 317                                 case CEXPR_DOM:
 318                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 319                                                                   val2 - 1);
 320                                         continue;
 321                                 case CEXPR_DOMBY:
 322                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 323                                                                   val1 - 1);
 324                                         continue;
 325                                 case CEXPR_INCOMP:
 326                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 327                                                                     val2 - 1) &&
 328                                                    !ebitmap_get_bit(&r2->dominates,
 329                                                                     val1 - 1));
 330                                         continue;
 331                                 default:
 332                                         break;
 333                                 }
 334                                 break;
 335                         case CEXPR_L1L2:
 336                                 l1 = &(scontext->range.level[0]);
 337                                 l2 = &(tcontext->range.level[0]);
 338                                 goto mls_ops;
 339                         case CEXPR_L1H2:
 340                                 l1 = &(scontext->range.level[0]);
 341                                 l2 = &(tcontext->range.level[1]);
 342                                 goto mls_ops;
 343                         case CEXPR_H1L2:
 344                                 l1 = &(scontext->range.level[1]);
 345                                 l2 = &(tcontext->range.level[0]);
 346                                 goto mls_ops;
 347                         case CEXPR_H1H2:
 348                                 l1 = &(scontext->range.level[1]);
 349                                 l2 = &(tcontext->range.level[1]);
 350                                 goto mls_ops;
 351                         case CEXPR_L1H1:
 352                                 l1 = &(scontext->range.level[0]);
 353                                 l2 = &(scontext->range.level[1]);
 354                                 goto mls_ops;
 355                         case CEXPR_L2H2:
 356                                 l1 = &(tcontext->range.level[0]);
 357                                 l2 = &(tcontext->range.level[1]);
 358                                 goto mls_ops;
 359 mls_ops:
 360                         switch (e->op) {
 361                         case CEXPR_EQ:
 362                                 s[++sp] = mls_level_eq(l1, l2);
 363                                 continue;
 364                         case CEXPR_NEQ:
 365                                 s[++sp] = !mls_level_eq(l1, l2);
 366                                 continue;
 367                         case CEXPR_DOM:
 368                                 s[++sp] = mls_level_dom(l1, l2);
 369                                 continue;
 370                         case CEXPR_DOMBY:
 371                                 s[++sp] = mls_level_dom(l2, l1);
 372                                 continue;
 373                         case CEXPR_INCOMP:
 374                                 s[++sp] = mls_level_incomp(l2, l1);
 375                                 continue;
 376                         default:
 377                                 BUG();
 378                                 return 0;
 379                         }
 380                         break;
 381                         default:
 382                                 BUG();
 383                                 return 0;
 384                         }
 385
 386                         switch (e->op) {
 387                         case CEXPR_EQ:
 388                                 s[++sp] = (val1 == val2);
 389                                 break;
 390                         case CEXPR_NEQ:
 391                                 s[++sp] = (val1 != val2);
 392                                 break;
 393                         default:
 394                                 BUG();
 395                                 return 0;
 396                         }
 397                         break;
 398                 case CEXPR_NAMES:
 399                         if (sp == (CEXPR_MAXDEPTH-1))
 400                                 return 0;
 401                         c = scontext;
 402                         if (e->attr & CEXPR_TARGET)
 403                                 c = tcontext;
 404                         else if (e->attr & CEXPR_XTARGET) {
 405                                 c = xcontext;
 406                                 if (!c) {
 407                                         BUG();
 408                                         return 0;
 409                                 }
 410                         }
 411                         if (e->attr & CEXPR_USER)
 412                                 val1 = c->user;
 413                         else if (e->attr & CEXPR_ROLE)
 414                                 val1 = c->role;
 415                         else if (e->attr & CEXPR_TYPE)
 416                                 val1 = c->type;
 417                         else {
 418                                 BUG();
 419                                 return 0;
 420                         }
 421
 422                         switch (e->op) {
 423                         case CEXPR_EQ:
 424                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 425                                 break;
 426                         case CEXPR_NEQ:
 427                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 428                                 break;
 429                         default:
 430                                 BUG();
 431                                 return 0;
 432                         }
 433                         break;
 434                 default:
 435                         BUG();
 436                         return 0;
 437                 }
 438         }
 439
 440         BUG_ON(sp != 0);
 441         return s[0];
 442 }
 443
 444 /*
 445  * security_dump_masked_av - dumps masked permissions during
 446  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 447  */
 448 static int dump_masked_av_helper(void *k, void *d, void *args)
 449 {
 450         struct perm_datum *pdatum = d;
 451         char **permission_names = args;
 452
 453         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 454
 455         permission_names[pdatum->value - 1] = (char *)k;
 456
 457         return 0;
 458 }
 459
 460 static void security_dump_masked_av(struct context *scontext,
 461                                     struct context *tcontext,
 462                                     u16 tclass,
 463                                     u32 permissions,
 464                                     const char *reason)
 465 {
 466         struct common_datum *common_dat;
 467         struct class_datum *tclass_dat;
 468         struct audit_buffer *ab;
 469         char *tclass_name;
 470         char *scontext_name = NULL;
 471         char *tcontext_name = NULL;
 472         char *permission_names[32];
 473         int index;
 474         u32 length;
 475         bool need_comma = false;
 476
 477         if (!permissions)
 478                 return;
 479
 480         tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1);
 481         tclass_dat = policydb.class_val_to_struct[tclass - 1];
 482         common_dat = tclass_dat->comdatum;
 483
 484         /* init permission_names */
 485         if (common_dat &&
 486             hashtab_map(common_dat->permissions.table,
 487                         dump_masked_av_helper, permission_names) < 0)
 488                 goto out;
 489
 490         if (hashtab_map(tclass_dat->permissions.table,
 491                         dump_masked_av_helper, permission_names) < 0)
 492                 goto out;
 493
 494         /* get scontext/tcontext in text form */
 495         if (context_struct_to_string(scontext,
 496                                      &scontext_name, &length) < 0)
 497                 goto out;
 498
 499         if (context_struct_to_string(tcontext,
 500                                      &tcontext_name, &length) < 0)
 501                 goto out;
 502
 503         /* audit a message */
 504         ab = audit_log_start(current->audit_context,
 505                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 506         if (!ab)
 507                 goto out;
 508
 509         audit_log_format(ab, "op=security_compute_av reason=%s "
 510                          "scontext=%s tcontext=%s tclass=%s perms=",
 511                          reason, scontext_name, tcontext_name, tclass_name);
 512
 513         for (index = 0; index < 32; index++) {
 514                 u32 mask = (1 << index);
 515
 516                 if ((mask & permissions) == 0)
 517                         continue;
 518
 519                 audit_log_format(ab, "%s%s",
 520                                  need_comma ? "," : "",
 521                                  permission_names[index]
 522                                  ? permission_names[index] : "????");
 523                 need_comma = true;
 524         }
 525         audit_log_end(ab);
 526 out:
 527         /* release scontext/tcontext */
 528         kfree(tcontext_name);
 529         kfree(scontext_name);
 530
 531         return;
 532 }
 533
 534 /*
 535  * security_boundary_permission - drops violated permissions
 536  * on boundary constraint.
 537  */
 538 static void type_attribute_bounds_av(struct context *scontext,
 539                                      struct context *tcontext,
 540                                      u16 tclass,
 541                                      struct av_decision *avd)
 542 {
 543         struct context lo_scontext;
 544         struct context lo_tcontext;
 545         struct av_decision lo_avd;
 546         struct type_datum *source;
 547         struct type_datum *target;
 548         u32 masked = 0;
 549
 550         source = flex_array_get_ptr(policydb.type_val_to_struct_array,
 551                                     scontext->type - 1);
 552         BUG_ON(!source);
 553
 554         target = flex_array_get_ptr(policydb.type_val_to_struct_array,
 555                                     tcontext->type - 1);
 556         BUG_ON(!target);
 557
 558         if (source->bounds) {
 559                 memset(&lo_avd, 0, sizeof(lo_avd));
 560
 561                 memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 562                 lo_scontext.type = source->bounds;
 563
 564                 context_struct_compute_av(&lo_scontext,
 565                                           tcontext,
 566                                           tclass,
 567                                           &lo_avd);
 568                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 569                         return;         /* no masked permission */
 570                 masked = ~lo_avd.allowed & avd->allowed;
 571         }
 572
 573         if (target->bounds) {
 574                 memset(&lo_avd, 0, sizeof(lo_avd));
 575
 576                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 577                 lo_tcontext.type = target->bounds;
 578
 579                 context_struct_compute_av(scontext,
 580                                           &lo_tcontext,
 581                                           tclass,
 582                                           &lo_avd);
 583                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 584                         return;         /* no masked permission */
 585                 masked = ~lo_avd.allowed & avd->allowed;
 586         }
 587
 588         if (source->bounds && target->bounds) {
 589                 memset(&lo_avd, 0, sizeof(lo_avd));
 590                 /*
 591                  * lo_scontext and lo_tcontext are already
 592                  * set up.
 593                  */
 594
 595                 context_struct_compute_av(&lo_scontext,
 596                                           &lo_tcontext,
 597                                           tclass,
 598                                           &lo_avd);
 599                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
 600                         return;         /* no masked permission */
 601                 masked = ~lo_avd.allowed & avd->allowed;
 602         }
 603
 604         if (masked) {
 605                 /* mask violated permissions */
 606                 avd->allowed &= ~masked;
 607
 608                 /* audit masked permissions */
 609                 security_dump_masked_av(scontext, tcontext,
 610                                         tclass, masked, "bounds");
 611         }
 612 }
 613
 614 /*
 615  * Compute access vectors based on a context structure pair for
 616  * the permissions in a particular class.
 617  */
 618 static void context_struct_compute_av(struct context *scontext,
 619                                       struct context *tcontext,
 620                                       u16 tclass,
 621                                       struct av_decision *avd)
 622 {
 623         struct constraint_node *constraint;
 624         struct role_allow *ra;
 625         struct avtab_key avkey;
 626         struct avtab_node *node;
 627         struct class_datum *tclass_datum;
 628         struct ebitmap *sattr, *tattr;
 629         struct ebitmap_node *snode, *tnode;
 630         unsigned int i, j;
 631
 632         avd->allowed = 0;
 633         avd->auditallow = 0;
 634         avd->auditdeny = 0xffffffff;
 635
 636         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
 637                 if (printk_ratelimit())
 638                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
 639                 return;
 640         }
 641
 642         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 643
 644         /*
 645          * If a specific type enforcement rule was defined for
 646          * this permission check, then use it.
 647          */
 648         avkey.target_class = tclass;
 649         avkey.specified = AVTAB_AV;
 650         sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1);
 651         BUG_ON(!sattr);
 652         tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1);
 653         BUG_ON(!tattr);
 654         ebitmap_for_each_positive_bit(sattr, snode, i) {
 655                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 656                         avkey.source_type = i + 1;
 657                         avkey.target_type = j + 1;
 658                         for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 659                              node;
 660                              node = avtab_search_node_next(node, avkey.specified)) {
 661                                 if (node->key.specified == AVTAB_ALLOWED)
 662                                         avd->allowed |= node->datum.data;
 663                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 664                                         avd->auditallow |= node->datum.data;
 665                                 else if (node->key.specified == AVTAB_AUDITDENY)
 666                                         avd->auditdeny &= node->datum.data;
 667                         }
 668
 669                         /* Check conditional av table for additional permissions */
 670                         cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 671
 672                 }
 673         }
 674
 675         /*
 676          * Remove any permissions prohibited by a constraint (this includes
 677          * the MLS policy).
 678          */
 679         constraint = tclass_datum->constraints;
 680         while (constraint) {
 681                 if ((constraint->permissions & (avd->allowed)) &&
 682                     !constraint_expr_eval(scontext, tcontext, NULL,
 683                                           constraint->expr)) {
 684                         avd->allowed &= ~(constraint->permissions);
 685                 }
 686                 constraint = constraint->next;
 687         }
 688
 689         /*
 690          * If checking process transition permission and the
 691          * role is changing, then check the (current_role, new_role)
 692          * pair.
 693          */
 694         if (tclass == policydb.process_class &&
 695             (avd->allowed & policydb.process_trans_perms) &&
 696             scontext->role != tcontext->role) {
 697                 for (ra = policydb.role_allow; ra; ra = ra->next) {
 698                         if (scontext->role == ra->role &&
 699                             tcontext->role == ra->new_role)
 700                                 break;
 701                 }
 702                 if (!ra)
 703                         avd->allowed &= ~policydb.process_trans_perms;
 704         }
 705
 706         /*
 707          * If the given source and target types have boundary
 708          * constraint, lazy checks have to mask any violated
 709          * permission and notice it to userspace via audit.
 710          */
 711         type_attribute_bounds_av(scontext, tcontext,
 712                                  tclass, avd);
 713 }
 714
 715 static int security_validtrans_handle_fail(struct context *ocontext,
 716                                            struct context *ncontext,
 717                                            struct context *tcontext,
 718                                            u16 tclass)
 719 {
 720         char *o = NULL, *n = NULL, *t = NULL;
 721         u32 olen, nlen, tlen;
 722
 723         if (context_struct_to_string(ocontext, &o, &olen))
 724                 goto out;
 725         if (context_struct_to_string(ncontext, &n, &nlen))
 726                 goto out;
 727         if (context_struct_to_string(tcontext, &t, &tlen))
 728                 goto out;
 729         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 730                   "security_validate_transition:  denied for"
 731                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 732                   o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
 733 out:
 734         kfree(o);
 735         kfree(n);
 736         kfree(t);
 737
 738         if (!selinux_enforcing)
 739                 return 0;
 740         return -EPERM;
 741 }
 742
 743 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 744                                  u16 orig_tclass)
 745 {
 746         struct context *ocontext;
 747         struct context *ncontext;
 748         struct context *tcontext;
 749         struct class_datum *tclass_datum;
 750         struct constraint_node *constraint;
 751         u16 tclass;
 752         int rc = 0;
 753
 754         if (!ss_initialized)
 755                 return 0;
 756
 757         read_lock(&policy_rwlock);
 758
 759         tclass = unmap_class(orig_tclass);
 760
 761         if (!tclass || tclass > policydb.p_classes.nprim) {
 762                 printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
 763                         __func__, tclass);
 764                 rc = -EINVAL;
 765                 goto out;
 766         }
 767         tclass_datum = policydb.class_val_to_struct[tclass - 1];
 768
 769         ocontext = sidtab_search(&sidtab, oldsid);
 770         if (!ocontext) {
 771                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 772                         __func__, oldsid);
 773                 rc = -EINVAL;
 774                 goto out;
 775         }
 776
 777         ncontext = sidtab_search(&sidtab, newsid);
 778         if (!ncontext) {
 779                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 780                         __func__, newsid);
 781                 rc = -EINVAL;
 782                 goto out;
 783         }
 784
 785         tcontext = sidtab_search(&sidtab, tasksid);
 786         if (!tcontext) {
 787                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 788                         __func__, tasksid);
 789                 rc = -EINVAL;
 790                 goto out;
 791         }
 792
 793         constraint = tclass_datum->validatetrans;
 794         while (constraint) {
 795                 if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 796                                           constraint->expr)) {
 797                         rc = security_validtrans_handle_fail(ocontext, ncontext,
 798                                                              tcontext, tclass);
 799                         goto out;
 800                 }
 801                 constraint = constraint->next;
 802         }
 803
 804 out:
 805         read_unlock(&policy_rwlock);
 806         return rc;
 807 }
 808
 809 /*
 810  * security_bounded_transition - check whether the given
 811  * transition is directed to bounded, or not.
 812  * It returns 0, if @newsid is bounded by @oldsid.
 813  * Otherwise, it returns error code.
 814  *
 815  * @oldsid : current security identifier
 816  * @newsid : destinated security identifier
 817  */
 818 int security_bounded_transition(u32 old_sid, u32 new_sid)
 819 {
 820         struct context *old_context, *new_context;
 821         struct type_datum *type;
 822         int index;
 823         int rc;
 824
 825         read_lock(&policy_rwlock);
 826
 827         rc = -EINVAL;
 828         old_context = sidtab_search(&sidtab, old_sid);
 829         if (!old_context) {
 830                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 831                        __func__, old_sid);
 832                 goto out;
 833         }
 834
 835         rc = -EINVAL;
 836         new_context = sidtab_search(&sidtab, new_sid);
 837         if (!new_context) {
 838                 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
 839                        __func__, new_sid);
 840                 goto out;
 841         }
 842
 843         rc = 0;
 844         /* type/domain unchanged */
 845         if (old_context->type == new_context->type)
 846                 goto out;
 847
 848         index = new_context->type;
 849         while (true) {
 850                 type = flex_array_get_ptr(policydb.type_val_to_struct_array,
 851                                           index - 1);
 852                 BUG_ON(!type);
 853
 854                 /* not bounded anymore */
 855                 rc = -EPERM;
 856                 if (!type->bounds)
 857                         break;
 858
 859                 /* @newsid is bounded by @oldsid */
 860                 rc = 0;
 861                 if (type->bounds == old_context->type)
 862                         break;
 863
 864                 index = type->bounds;
 865         }
 866
 867         if (rc) {
 868                 char *old_name = NULL;
 869                 char *new_name = NULL;
 870                 u32 length;
 871
 872                 if (!context_struct_to_string(old_context,
 873                                               &old_name, &length) &&
 874                     !context_struct_to_string(new_context,
 875                                               &new_name, &length)) {
 876                         audit_log(current->audit_context,
 877                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 878                                   "op=security_bounded_transition "
 879                                   "result=denied "
 880                                   "oldcontext=%s newcontext=%s",
 881                                   old_name, new_name);
 882                 }
 883                 kfree(new_name);
 884                 kfree(old_name);
 885         }
 886 out:
 887         read_unlock(&policy_rwlock);
 888
 889         return rc;
 890 }
 891
 892 static void avd_init(struct av_decision *avd)
 893 {
 894         avd->allowed = 0;
 895         avd->auditallow = 0;
 896         avd->auditdeny = 0xffffffff;
 897         avd->seqno = latest_granting;
 898         avd->flags = 0;
 899 }
 900
 901
 902 /**
 903  * security_compute_av - Compute access vector decisions.
 904  * @ssid: source security identifier
 905  * @tsid: target security identifier
 906  * @tclass: target security class
 907  * @avd: access vector decisions
 908  *
 909  * Compute a set of access vector decisions based on the
 910  * SID pair (@ssid, @tsid) for the permissions in @tclass.
 911  */
 912 void security_compute_av(u32 ssid,
 913                          u32 tsid,
 914                          u16 orig_tclass,
 915                          struct av_decision *avd)
 916 {
 917         u16 tclass;
 918         struct context *scontext = NULL, *tcontext = NULL;
 919
 920         read_lock(&policy_rwlock);
 921         avd_init(avd);
 922         if (!ss_initialized)
 923                 goto allow;
 924
 925         scontext = sidtab_search(&sidtab, ssid);
 926         if (!scontext) {
 927                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 928                        __func__, ssid);
 929                 goto out;
 930         }
 931
 932         /* permissive domain? */
 933         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 934                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 935
 936         tcontext = sidtab_search(&sidtab, tsid);
 937         if (!tcontext) {
 938                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 939                        __func__, tsid);
 940                 goto out;
 941         }
 942
 943         tclass = unmap_class(orig_tclass);
 944         if (unlikely(orig_tclass && !tclass)) {
 945                 if (policydb.allow_unknown)
 946                         goto allow;
 947                 goto out;
 948         }
 949         context_struct_compute_av(scontext, tcontext, tclass, avd);
 950         map_decision(orig_tclass, avd, policydb.allow_unknown);
 951 out:
 952         read_unlock(&policy_rwlock);
 953         return;
 954 allow:
 955         avd->allowed = 0xffffffff;
 956         goto out;
 957 }
 958
 959 void security_compute_av_user(u32 ssid,
 960                               u32 tsid,
 961                               u16 tclass,
 962                               struct av_decision *avd)
 963 {
 964         struct context *scontext = NULL, *tcontext = NULL;
 965
 966         read_lock(&policy_rwlock);
 967         avd_init(avd);
 968         if (!ss_initialized)
 969                 goto allow;
 970
 971         scontext = sidtab_search(&sidtab, ssid);
 972         if (!scontext) {
 973                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 974                        __func__, ssid);
 975                 goto out;
 976         }
 977
 978         /* permissive domain? */
 979         if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
 980                 avd->flags |= AVD_FLAGS_PERMISSIVE;
 981
 982         tcontext = sidtab_search(&sidtab, tsid);
 983         if (!tcontext) {
 984                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
 985                        __func__, tsid);
 986                 goto out;
 987         }
 988
 989         if (unlikely(!tclass)) {
 990                 if (policydb.allow_unknown)
 991                         goto allow;
 992                 goto out;
 993         }
 994
 995         context_struct_compute_av(scontext, tcontext, tclass, avd);
 996  out:
 997         read_unlock(&policy_rwlock);
 998         return;
 999 allow:
1000         avd->allowed = 0xffffffff;
1001         goto out;
1002 }
1003
1004 /*
1005  * Write the security context string representation of
1006  * the context structure `context' into a dynamically
1007  * allocated string of the correct size.  Set `*scontext'
1008  * to point to this string and set `*scontext_len' to
1009  * the length of the string.
1010  */
1011 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
1012 {
1013         char *scontextp;
1014
1015         if (scontext)
1016                 *scontext = NULL;
1017         *scontext_len = 0;
1018
1019         if (context->len) {
1020                 *scontext_len = context->len;
1021                 *scontext = kstrdup(context->str, GFP_ATOMIC);
1022                 if (!(*scontext))
1023                         return -ENOMEM;
1024                 return 0;
1025         }
1026
1027         /* Compute the size of the context. */
1028         *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1;
1029         *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1;
1030         *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1;
1031         *scontext_len += mls_compute_context_len(context);
1032
1033         if (!scontext)
1034                 return 0;
1035
1036         /* Allocate space for the context; caller must free this space. */
1037         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1038         if (!scontextp)
1039                 return -ENOMEM;
1040         *scontext = scontextp;
1041
1042         /*
1043          * Copy the user name, role name and type name into the context.
1044          */
1045         sprintf(scontextp, "%s:%s:%s",
1046                 sym_name(&policydb, SYM_USERS, context->user - 1),
1047                 sym_name(&policydb, SYM_ROLES, context->role - 1),
1048                 sym_name(&policydb, SYM_TYPES, context->type - 1));
1049         scontextp += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) +
1050                      1 + strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) +
1051                      1 + strlen(sym_name(&policydb, SYM_TYPES, context->type - 1));
1052
1053         mls_sid_to_context(context, &scontextp);
1054
1055         *scontextp = 0;
1056
1057         return 0;
1058 }
1059
1060 #include "initial_sid_to_string.h"
1061
1062 const char *security_get_initial_sid_context(u32 sid)
1063 {
1064         if (unlikely(sid > SECINITSID_NUM))
1065                 return NULL;
1066         return initial_sid_to_string[sid];
1067 }
1068
1069 static int security_sid_to_context_core(u32 sid, char **scontext,
1070                                         u32 *scontext_len, int force)
1071 {
1072         struct context *context;
1073         int rc = 0;
1074
1075         if (scontext)
1076                 *scontext = NULL;
1077         *scontext_len  = 0;
1078
1079         if (!ss_initialized) {
1080                 if (sid <= SECINITSID_NUM) {
1081                         char *scontextp;
1082
1083                         *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
1084                         if (!scontext)
1085                                 goto out;
1086                         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1087                         if (!scontextp) {
1088                                 rc = -ENOMEM;
1089                                 goto out;
1090                         }
1091                         strcpy(scontextp, initial_sid_to_string[sid]);
1092                         *scontext = scontextp;
1093                         goto out;
1094                 }
1095                 printk(KERN_ERR "SELinux: %s:  called before initial "
1096                        "load_policy on unknown SID %d\n", __func__, sid);
1097                 rc = -EINVAL;
1098                 goto out;
1099         }
1100         read_lock(&policy_rwlock);
1101         if (force)
1102                 context = sidtab_search_force(&sidtab, sid);
1103         else
1104                 context = sidtab_search(&sidtab, sid);
1105         if (!context) {
1106                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1107                         __func__, sid);
1108                 rc = -EINVAL;
1109                 goto out_unlock;
1110         }
1111         rc = context_struct_to_string(context, scontext, scontext_len);
1112 out_unlock:
1113         read_unlock(&policy_rwlock);
1114 out:
1115         return rc;
1116
1117 }
1118
1119 /**
1120  * security_sid_to_context - Obtain a context for a given SID.
1121  * @sid: security identifier, SID
1122  * @scontext: security context
1123  * @scontext_len: length in bytes
1124  *
1125  * Write the string representation of the context associated with @sid
1126  * into a dynamically allocated string of the correct size.  Set @scontext
1127  * to point to this string and set @scontext_len to the length of the string.
1128  */
1129 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
1130 {
1131         return security_sid_to_context_core(sid, scontext, scontext_len, 0);
1132 }
1133
1134 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len)
1135 {
1136         return security_sid_to_context_core(sid, scontext, scontext_len, 1);
1137 }
1138
1139 /*
1140  * Caveat:  Mutates scontext.
1141  */
1142 static int string_to_context_struct(struct policydb *pol,
1143                                     struct sidtab *sidtabp,
1144                                     char *scontext,
1145                                     u32 scontext_len,
1146                                     struct context *ctx,
1147                                     u32 def_sid)
1148 {
1149         struct role_datum *role;
1150         struct type_datum *typdatum;
1151         struct user_datum *usrdatum;
1152         char *scontextp, *p, oldc;
1153         int rc = 0;
1154
1155         context_init(ctx);
1156
1157         /* Parse the security context. */
1158
1159         rc = -EINVAL;
1160         scontextp = (char *) scontext;
1161
1162         /* Extract the user. */
1163         p = scontextp;
1164         while (*p && *p != ':')
1165                 p++;
1166
1167         if (*p == 0)
1168                 goto out;
1169
1170         *p++ = 0;
1171
1172         usrdatum = hashtab_search(pol->p_users.table, scontextp);
1173         if (!usrdatum)
1174                 goto out;
1175
1176         ctx->user = usrdatum->value;
1177
1178         /* Extract role. */
1179         scontextp = p;
1180         while (*p && *p != ':')
1181                 p++;
1182
1183         if (*p == 0)
1184                 goto out;
1185
1186         *p++ = 0;
1187
1188         role = hashtab_search(pol->p_roles.table, scontextp);
1189         if (!role)
1190                 goto out;
1191         ctx->role = role->value;
1192
1193         /* Extract type. */
1194         scontextp = p;
1195         while (*p && *p != ':')
1196                 p++;
1197         oldc = *p;
1198         *p++ = 0;
1199
1200         typdatum = hashtab_search(pol->p_types.table, scontextp);
1201         if (!typdatum || typdatum->attribute)
1202                 goto out;
1203
1204         ctx->type = typdatum->value;
1205
1206         rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
1207         if (rc)
1208                 goto out;
1209
1210         rc = -EINVAL;
1211         if ((p - scontext) < scontext_len)
1212                 goto out;
1213
1214         /* Check the validity of the new context. */
1215         if (!policydb_context_isvalid(pol, ctx))
1216                 goto out;
1217         rc = 0;
1218 out:
1219         if (rc)
1220                 context_destroy(ctx);
1221         return rc;
1222 }
1223
1224 static int security_context_to_sid_core(const char *scontext, u32 scontext_len,
1225                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1226                                         int force)
1227 {
1228         char *scontext2, *str = NULL;
1229         struct context context;
1230         int rc = 0;
1231
1232         if (!ss_initialized) {
1233                 int i;
1234
1235                 for (i = 1; i < SECINITSID_NUM; i++) {
1236                         if (!strcmp(initial_sid_to_string[i], scontext)) {
1237                                 *sid = i;
1238                                 return 0;
1239                         }
1240                 }
1241                 *sid = SECINITSID_KERNEL;
1242                 return 0;
1243         }
1244         *sid = SECSID_NULL;
1245
1246         /* Copy the string so that we can modify the copy as we parse it. */
1247         scontext2 = kmalloc(scontext_len + 1, gfp_flags);
1248         if (!scontext2)
1249                 return -ENOMEM;
1250         memcpy(scontext2, scontext, scontext_len);
1251         scontext2[scontext_len] = 0;
1252
1253         if (force) {
1254                 /* Save another copy for storing in uninterpreted form */
1255                 rc = -ENOMEM;
1256                 str = kstrdup(scontext2, gfp_flags);
1257                 if (!str)
1258                         goto out;
1259         }
1260
1261         read_lock(&policy_rwlock);
1262         rc = string_to_context_struct(&policydb, &sidtab, scontext2,
1263                                       scontext_len, &context, def_sid);
1264         if (rc == -EINVAL && force) {
1265                 context.str = str;
1266                 context.len = scontext_len;
1267                 str = NULL;
1268         } else if (rc)
1269                 goto out_unlock;
1270         rc = sidtab_context_to_sid(&sidtab, &context, sid);
1271         context_destroy(&context);
1272 out_unlock:
1273         read_unlock(&policy_rwlock);
1274 out:
1275         kfree(scontext2);
1276         kfree(str);
1277         return rc;
1278 }
1279
1280 /**
1281  * security_context_to_sid - Obtain a SID for a given security context.
1282  * @scontext: security context
1283  * @scontext_len: length in bytes
1284  * @sid: security identifier, SID
1285  *
1286  * Obtains a SID associated with the security context that
1287  * has the string representation specified by @scontext.
1288  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1289  * memory is available, or 0 on success.
1290  */
1291 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid)
1292 {
1293         return security_context_to_sid_core(scontext, scontext_len,
1294                                             sid, SECSID_NULL, GFP_KERNEL, 0);
1295 }
1296
1297 /**
1298  * security_context_to_sid_default - Obtain a SID for a given security context,
1299  * falling back to specified default if needed.
1300  *
1301  * @scontext: security context
1302  * @scontext_len: length in bytes
1303  * @sid: security identifier, SID
1304  * @def_sid: default SID to assign on error
1305  *
1306  * Obtains a SID associated with the security context that
1307  * has the string representation specified by @scontext.
1308  * The default SID is passed to the MLS layer to be used to allow
1309  * kernel labeling of the MLS field if the MLS field is not present
1310  * (for upgrading to MLS without full relabel).
1311  * Implicitly forces adding of the context even if it cannot be mapped yet.
1312  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1313  * memory is available, or 0 on success.
1314  */
1315 int security_context_to_sid_default(const char *scontext, u32 scontext_len,
1316                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1317 {
1318         return security_context_to_sid_core(scontext, scontext_len,
1319                                             sid, def_sid, gfp_flags, 1);
1320 }
1321
1322 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
1323                                   u32 *sid)
1324 {
1325         return security_context_to_sid_core(scontext, scontext_len,
1326                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1327 }
1328
1329 static int compute_sid_handle_invalid_context(
1330         struct context *scontext,
1331         struct context *tcontext,
1332         u16 tclass,
1333         struct context *newcontext)
1334 {
1335         char *s = NULL, *t = NULL, *n = NULL;
1336         u32 slen, tlen, nlen;
1337
1338         if (context_struct_to_string(scontext, &s, &slen))
1339                 goto out;
1340         if (context_struct_to_string(tcontext, &t, &tlen))
1341                 goto out;
1342         if (context_struct_to_string(newcontext, &n, &nlen))
1343                 goto out;
1344         audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
1345                   "security_compute_sid:  invalid context %s"
1346                   " for scontext=%s"
1347                   " tcontext=%s"
1348                   " tclass=%s",
1349                   n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1));
1350 out:
1351         kfree(s);
1352         kfree(t);
1353         kfree(n);
1354         if (!selinux_enforcing)
1355                 return 0;
1356         return -EACCES;
1357 }
1358
1359 static void filename_compute_type(struct policydb *p, struct context *newcontext,
1360                                   u32 stype, u32 ttype, u16 tclass,
1361                                   const char *objname)
1362 {
1363         struct filename_trans ft;
1364         struct filename_trans_datum *otype;
1365
1366         /*
1367          * Most filename trans rules are going to live in specific directories
1368          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1369          * if the ttype does not contain any rules.
1370          */
1371         if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype))
1372                 return;
1373
1374         ft.stype = stype;
1375         ft.ttype = ttype;
1376         ft.tclass = tclass;
1377         ft.name = objname;
1378
1379         otype = hashtab_search(p->filename_trans, &ft);
1380         if (otype)
1381                 newcontext->type = otype->otype;
1382 }
1383
1384 static int security_compute_sid(u32 ssid,
1385                                 u32 tsid,
1386                                 u16 orig_tclass,
1387                                 u32 specified,
1388                                 const char *objname,
1389                                 u32 *out_sid,
1390                                 bool kern)
1391 {
1392         struct class_datum *cladatum = NULL;
1393         struct context *scontext = NULL, *tcontext = NULL, newcontext;
1394         struct role_trans *roletr = NULL;
1395         struct avtab_key avkey;
1396         struct avtab_datum *avdatum;
1397         struct avtab_node *node;
1398         u16 tclass;
1399         int rc = 0;
1400         bool sock;
1401
1402         if (!ss_initialized) {
1403                 switch (orig_tclass) {
1404                 case SECCLASS_PROCESS: /* kernel value */
1405                         *out_sid = ssid;
1406                         break;
1407                 default:
1408                         *out_sid = tsid;
1409                         break;
1410                 }
1411                 goto out;
1412         }
1413
1414         context_init(&newcontext);
1415
1416         read_lock(&policy_rwlock);
1417
1418         if (kern) {
1419                 tclass = unmap_class(orig_tclass);
1420                 sock = security_is_socket_class(orig_tclass);
1421         } else {
1422                 tclass = orig_tclass;
1423                 sock = security_is_socket_class(map_class(tclass));
1424         }
1425
1426         scontext = sidtab_search(&sidtab, ssid);
1427         if (!scontext) {
1428                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1429                        __func__, ssid);
1430                 rc = -EINVAL;
1431                 goto out_unlock;
1432         }
1433         tcontext = sidtab_search(&sidtab, tsid);
1434         if (!tcontext) {
1435                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
1436                        __func__, tsid);
1437                 rc = -EINVAL;
1438                 goto out_unlock;
1439         }
1440
1441         if (tclass && tclass <= policydb.p_classes.nprim)
1442                 cladatum = policydb.class_val_to_struct[tclass - 1];
1443
1444         /* Set the user identity. */
1445         switch (specified) {
1446         case AVTAB_TRANSITION:
1447         case AVTAB_CHANGE:
1448                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1449                         newcontext.user = tcontext->user;
1450                 } else {
1451                         /* notice this gets both DEFAULT_SOURCE and unset */
1452                         /* Use the process user identity. */
1453                         newcontext.user = scontext->user;
1454                 }
1455                 break;
1456         case AVTAB_MEMBER:
1457                 /* Use the related object owner. */
1458                 newcontext.user = tcontext->user;
1459                 break;
1460         }
1461
1462         /* Set the role to default values. */
1463         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1464                 newcontext.role = scontext->role;
1465         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1466                 newcontext.role = tcontext->role;
1467         } else {
1468                 if ((tclass == policydb.process_class) || (sock == true))
1469                         newcontext.role = scontext->role;
1470                 else
1471                         newcontext.role = OBJECT_R_VAL;
1472         }
1473
1474         /* Set the type to default values. */
1475         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1476                 newcontext.type = scontext->type;
1477         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1478                 newcontext.type = tcontext->type;
1479         } else {
1480                 if ((tclass == policydb.process_class) || (sock == true)) {
1481                         /* Use the type of process. */
1482                         newcontext.type = scontext->type;
1483                 } else {
1484                         /* Use the type of the related object. */
1485                         newcontext.type = tcontext->type;
1486                 }
1487         }
1488
1489         /* Look for a type transition/member/change rule. */
1490         avkey.source_type = scontext->type;
1491         avkey.target_type = tcontext->type;
1492         avkey.target_class = tclass;
1493         avkey.specified = specified;
1494         avdatum = avtab_search(&policydb.te_avtab, &avkey);
1495
1496         /* If no permanent rule, also check for enabled conditional rules */
1497         if (!avdatum) {
1498                 node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
1499                 for (; node; node = avtab_search_node_next(node, specified)) {
1500                         if (node->key.specified & AVTAB_ENABLED) {
1501                                 avdatum = &node->datum;
1502                                 break;
1503                         }
1504                 }
1505         }
1506
1507         if (avdatum) {
1508                 /* Use the type from the type transition/member/change rule. */
1509                 newcontext.type = avdatum->data;
1510         }
1511
1512         /* if we have a objname this is a file trans check so check those rules */
1513         if (objname)
1514                 filename_compute_type(&policydb, &newcontext, scontext->type,
1515                                       tcontext->type, tclass, objname);
1516
1517         /* Check for class-specific changes. */
1518         if (specified & AVTAB_TRANSITION) {
1519                 /* Look for a role transition rule. */
1520                 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) {
1521                         if ((roletr->role == scontext->role) &&
1522                             (roletr->type == tcontext->type) &&
1523                             (roletr->tclass == tclass)) {
1524                                 /* Use the role transition rule. */
1525                                 newcontext.role = roletr->new_role;
1526                                 break;
1527                         }
1528                 }
1529         }
1530
1531         /* Set the MLS attributes.
1532            This is done last because it may allocate memory. */
1533         rc = mls_compute_sid(scontext, tcontext, tclass, specified,
1534                              &newcontext, sock);
1535         if (rc)
1536                 goto out_unlock;
1537
1538         /* Check the validity of the context. */
1539         if (!policydb_context_isvalid(&policydb, &newcontext)) {
1540                 rc = compute_sid_handle_invalid_context(scontext,
1541                                                         tcontext,
1542                                                         tclass,
1543                                                         &newcontext);
1544                 if (rc)
1545                         goto out_unlock;
1546         }
1547         /* Obtain the sid for the context. */
1548         rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
1549 out_unlock:
1550         read_unlock(&policy_rwlock);
1551         context_destroy(&newcontext);
1552 out:
1553         return rc;
1554 }
1555
1556 /**
1557  * security_transition_sid - Compute the SID for a new subject/object.
1558  * @ssid: source security identifier
1559  * @tsid: target security identifier
1560  * @tclass: target security class
1561  * @out_sid: security identifier for new subject/object
1562  *
1563  * Compute a SID to use for labeling a new subject or object in the
1564  * class @tclass based on a SID pair (@ssid, @tsid).
1565  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1566  * if insufficient memory is available, or %0 if the new SID was
1567  * computed successfully.
1568  */
1569 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass,
1570                             const struct qstr *qstr, u32 *out_sid)
1571 {
1572         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1573                                     qstr ? qstr->name : NULL, out_sid, true);
1574 }
1575
1576 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass,
1577                                  const char *objname, u32 *out_sid)
1578 {
1579         return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION,
1580                                     objname, out_sid, false);
1581 }
1582
1583 /**
1584  * security_member_sid - Compute the SID for member selection.
1585  * @ssid: source security identifier
1586  * @tsid: target security identifier
1587  * @tclass: target security class
1588  * @out_sid: security identifier for selected member
1589  *
1590  * Compute a SID to use when selecting a member of a polyinstantiated
1591  * object of class @tclass based on a SID pair (@ssid, @tsid).
1592  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1593  * if insufficient memory is available, or %0 if the SID was
1594  * computed successfully.
1595  */
1596 int security_member_sid(u32 ssid,
1597                         u32 tsid,
1598                         u16 tclass,
1599                         u32 *out_sid)
1600 {
1601         return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL,
1602                                     out_sid, false);
1603 }
1604
1605 /**
1606  * security_change_sid - Compute the SID for object relabeling.
1607  * @ssid: source security identifier
1608  * @tsid: target security identifier
1609  * @tclass: target security class
1610  * @out_sid: security identifier for selected member
1611  *
1612  * Compute a SID to use for relabeling an object of class @tclass
1613  * based on a SID pair (@ssid, @tsid).
1614  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1615  * if insufficient memory is available, or %0 if the SID was
1616  * computed successfully.
1617  */
1618 int security_change_sid(u32 ssid,
1619                         u32 tsid,
1620                         u16 tclass,
1621                         u32 *out_sid)
1622 {
1623         return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1624                                     out_sid, false);
1625 }
1626
1627 /* Clone the SID into the new SID table. */
1628 static int clone_sid(u32 sid,
1629                      struct context *context,
1630                      void *arg)
1631 {
1632         struct sidtab *s = arg;
1633
1634         if (sid > SECINITSID_NUM)
1635                 return sidtab_insert(s, sid, context);
1636         else
1637                 return 0;
1638 }
1639
1640 static inline int convert_context_handle_invalid_context(struct context *context)
1641 {
1642         char *s;
1643         u32 len;
1644
1645         if (selinux_enforcing)
1646                 return -EINVAL;
1647
1648         if (!context_struct_to_string(context, &s, &len)) {
1649                 printk(KERN_WARNING "SELinux:  Context %s would be invalid if enforcing\n", s);
1650                 kfree(s);
1651         }
1652         return 0;
1653 }
1654
1655 struct convert_context_args {
1656         struct policydb *oldp;
1657         struct policydb *newp;
1658 };
1659
1660 /*
1661  * Convert the values in the security context
1662  * structure `c' from the values specified
1663  * in the policy `p->oldp' to the values specified
1664  * in the policy `p->newp'.  Verify that the
1665  * context is valid under the new policy.
1666  */
1667 static int convert_context(u32 key,
1668                            struct context *c,
1669                            void *p)
1670 {
1671         struct convert_context_args *args;
1672         struct context oldc;
1673         struct ocontext *oc;
1674         struct mls_range *range;
1675         struct role_datum *role;
1676         struct type_datum *typdatum;
1677         struct user_datum *usrdatum;
1678         char *s;
1679         u32 len;
1680         int rc = 0;
1681
1682         if (key <= SECINITSID_NUM)
1683                 goto out;
1684
1685         args = p;
1686
1687         if (c->str) {
1688                 struct context ctx;
1689
1690                 rc = -ENOMEM;
1691                 s = kstrdup(c->str, GFP_KERNEL);
1692                 if (!s)
1693                         goto out;
1694
1695                 rc = string_to_context_struct(args->newp, NULL, s,
1696                                               c->len, &ctx, SECSID_NULL);
1697                 kfree(s);
1698                 if (!rc) {
1699                         printk(KERN_INFO "SELinux:  Context %s became valid (mapped).\n",
1700                                c->str);
1701                         /* Replace string with mapped representation. */
1702                         kfree(c->str);
1703                         memcpy(c, &ctx, sizeof(*c));
1704                         goto out;
1705                 } else if (rc == -EINVAL) {
1706                         /* Retain string representation for later mapping. */
1707                         rc = 0;
1708                         goto out;
1709                 } else {
1710                         /* Other error condition, e.g. ENOMEM. */
1711                         printk(KERN_ERR "SELinux:   Unable to map context %s, rc = %d.\n",
1712                                c->str, -rc);
1713                         goto out;
1714                 }
1715         }
1716
1717         rc = context_cpy(&oldc, c);
1718         if (rc)
1719                 goto out;
1720
1721         /* Convert the user. */
1722         rc = -EINVAL;
1723         usrdatum = hashtab_search(args->newp->p_users.table,
1724                                   sym_name(args->oldp, SYM_USERS, c->user - 1));
1725         if (!usrdatum)
1726                 goto bad;
1727         c->user = usrdatum->value;
1728
1729         /* Convert the role. */
1730         rc = -EINVAL;
1731         role = hashtab_search(args->newp->p_roles.table,
1732                               sym_name(args->oldp, SYM_ROLES, c->role - 1));
1733         if (!role)
1734                 goto bad;
1735         c->role = role->value;
1736
1737         /* Convert the type. */
1738         rc = -EINVAL;
1739         typdatum = hashtab_search(args->newp->p_types.table,
1740                                   sym_name(args->oldp, SYM_TYPES, c->type - 1));
1741         if (!typdatum)
1742                 goto bad;
1743         c->type = typdatum->value;
1744
1745         /* Convert the MLS fields if dealing with MLS policies */
1746         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
1747                 rc = mls_convert_context(args->oldp, args->newp, c);
1748                 if (rc)
1749                         goto bad;
1750         } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
1751                 /*
1752                  * Switching between MLS and non-MLS policy:
1753                  * free any storage used by the MLS fields in the
1754                  * context for all existing entries in the sidtab.
1755                  */
1756                 mls_context_destroy(c);
1757         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
1758                 /*
1759                  * Switching between non-MLS and MLS policy:
1760                  * ensure that the MLS fields of the context for all
1761                  * existing entries in the sidtab are filled in with a
1762                  * suitable default value, likely taken from one of the
1763                  * initial SIDs.
1764                  */
1765                 oc = args->newp->ocontexts[OCON_ISID];
1766                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
1767                         oc = oc->next;
1768                 rc = -EINVAL;
1769                 if (!oc) {
1770                         printk(KERN_ERR "SELinux:  unable to look up"
1771                                 " the initial SIDs list\n");
1772                         goto bad;
1773                 }
1774                 range = &oc->context[0].range;
1775                 rc = mls_range_set(c, range);
1776                 if (rc)
1777                         goto bad;
1778         }
1779
1780         /* Check the validity of the new context. */
1781         if (!policydb_context_isvalid(args->newp, c)) {
1782                 rc = convert_context_handle_invalid_context(&oldc);
1783                 if (rc)
1784                         goto bad;
1785         }
1786
1787         context_destroy(&oldc);
1788
1789         rc = 0;
1790 out:
1791         return rc;
1792 bad:
1793         /* Map old representation to string and save it. */
1794         rc = context_struct_to_string(&oldc, &s, &len);
1795         if (rc)
1796                 return rc;
1797         context_destroy(&oldc);
1798         context_destroy(c);
1799         c->str = s;
1800         c->len = len;
1801         printk(KERN_INFO "SELinux:  Context %s became invalid (unmapped).\n",
1802                c->str);
1803         rc = 0;
1804         goto out;
1805 }
1806
1807 static void security_load_policycaps(void)
1808 {
1809         selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
1810                                                   POLICYDB_CAPABILITY_NETPEER);
1811         selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps,
1812                                                   POLICYDB_CAPABILITY_OPENPERM);
1813 }
1814
1815 static int security_preserve_bools(struct policydb *p);
1816
1817 /**
1818  * security_load_policy - Load a security policy configuration.
1819  * @data: binary policy data
1820  * @len: length of data in bytes
1821  *
1822  * Load a new set of security policy configuration data,
1823  * validate it and convert the SID table as necessary.
1824  * This function will flush the access vector cache after
1825  * loading the new policy.
1826  */
1827 int security_load_policy(void *data, size_t len)
1828 {
1829         struct policydb oldpolicydb, newpolicydb;
1830         struct sidtab oldsidtab, newsidtab;
1831         struct selinux_mapping *oldmap, *map = NULL;
1832         struct convert_context_args args;
1833         u32 seqno;
1834         u16 map_size;
1835         int rc = 0;
1836         struct policy_file file = { data, len }, *fp = &file;
1837
1838         if (!ss_initialized) {
1839                 avtab_cache_init();
1840                 rc = policydb_read(&policydb, fp);
1841                 if (rc) {
1842                         avtab_cache_destroy();
1843                         return rc;
1844                 }
1845
1846                 policydb.len = len;
1847                 rc = selinux_set_mapping(&policydb, secclass_map,
1848                                          &current_mapping,
1849                                          &current_mapping_size);
1850                 if (rc) {
1851                         policydb_destroy(&policydb);
1852                         avtab_cache_destroy();
1853                         return rc;
1854                 }
1855
1856                 rc = policydb_load_isids(&policydb, &sidtab);
1857                 if (rc) {
1858                         policydb_destroy(&policydb);
1859                         avtab_cache_destroy();
1860                         return rc;
1861                 }
1862
1863                 security_load_policycaps();
1864                 ss_initialized = 1;
1865                 seqno = ++latest_granting;
1866                 selinux_complete_init();
1867                 avc_ss_reset(seqno);
1868                 selnl_notify_policyload(seqno);
1869                 selinux_status_update_policyload(seqno);
1870                 selinux_netlbl_cache_invalidate();
1871                 selinux_xfrm_notify_policyload();
1872                 return 0;
1873         }
1874
1875 #if 0
1876         sidtab_hash_eval(&sidtab, "sids");
1877 #endif
1878
1879         rc = policydb_read(&newpolicydb, fp);
1880         if (rc)
1881                 return rc;
1882
1883         newpolicydb.len = len;
1884         /* If switching between different policy types, log MLS status */
1885         if (policydb.mls_enabled && !newpolicydb.mls_enabled)
1886                 printk(KERN_INFO "SELinux: Disabling MLS support...\n");
1887         else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
1888                 printk(KERN_INFO "SELinux: Enabling MLS support...\n");
1889
1890         rc = policydb_load_isids(&newpolicydb, &newsidtab);
1891         if (rc) {
1892                 printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
1893                 policydb_destroy(&newpolicydb);
1894                 return rc;
1895         }
1896
1897         rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size);
1898         if (rc)
1899                 goto err;
1900
1901         rc = security_preserve_bools(&newpolicydb);
1902         if (rc) {
1903                 printk(KERN_ERR "SELinux:  unable to preserve booleans\n");
1904                 goto err;
1905         }
1906
1907         /* Clone the SID table. */
1908         sidtab_shutdown(&sidtab);
1909
1910         rc = sidtab_map(&sidtab, clone_sid, &newsidtab);
1911         if (rc)
1912                 goto err;
1913
1914         /*
1915          * Convert the internal representations of contexts
1916          * in the new SID table.
1917          */
1918         args.oldp = &policydb;
1919         args.newp = &newpolicydb;
1920         rc = sidtab_map(&newsidtab, convert_context, &args);
1921         if (rc) {
1922                 printk(KERN_ERR "SELinux:  unable to convert the internal"
1923                         " representation of contexts in the new SID"
1924                         " table\n");
1925                 goto err;
1926         }
1927
1928         /* Save the old policydb and SID table to free later. */
1929         memcpy(&oldpolicydb, &policydb, sizeof policydb);
1930         sidtab_set(&oldsidtab, &sidtab);
1931
1932         /* Install the new policydb and SID table. */
1933         write_lock_irq(&policy_rwlock);
1934         memcpy(&policydb, &newpolicydb, sizeof policydb);
1935         sidtab_set(&sidtab, &newsidtab);
1936         security_load_policycaps();
1937         oldmap = current_mapping;
1938         current_mapping = map;
1939         current_mapping_size = map_size;
1940         seqno = ++latest_granting;
1941         write_unlock_irq(&policy_rwlock);
1942
1943         /* Free the old policydb and SID table. */
1944         policydb_destroy(&oldpolicydb);
1945         sidtab_destroy(&oldsidtab);
1946         kfree(oldmap);
1947
1948         avc_ss_reset(seqno);
1949         selnl_notify_policyload(seqno);
1950         selinux_status_update_policyload(seqno);
1951         selinux_netlbl_cache_invalidate();
1952         selinux_xfrm_notify_policyload();
1953
1954         return 0;
1955
1956 err:
1957         kfree(map);
1958         sidtab_destroy(&newsidtab);
1959         policydb_destroy(&newpolicydb);
1960         return rc;
1961
1962 }
1963
1964 size_t security_policydb_len(void)
1965 {
1966         size_t len;
1967
1968         read_lock(&policy_rwlock);
1969         len = policydb.len;
1970         read_unlock(&policy_rwlock);
1971
1972         return len;
1973 }
1974
1975 /**
1976  * security_port_sid - Obtain the SID for a port.
1977  * @protocol: protocol number
1978  * @port: port number
1979  * @out_sid: security identifier
1980  */
1981 int security_port_sid(u8 protocol, u16 port, u32 *out_sid)
1982 {
1983         struct ocontext *c;
1984         int rc = 0;
1985
1986         read_lock(&policy_rwlock);
1987
1988         c = policydb.ocontexts[OCON_PORT];
1989         while (c) {
1990                 if (c->u.port.protocol == protocol &&
1991                     c->u.port.low_port <= port &&
1992                     c->u.port.high_port >= port)
1993                         break;
1994                 c = c->next;
1995         }
1996
1997         if (c) {
1998                 if (!c->sid[0]) {
1999                         rc = sidtab_context_to_sid(&sidtab,
2000                                                    &c->context[0],
2001                                                    &c->sid[0]);
2002                         if (rc)
2003                                 goto out;
2004                 }
2005                 *out_sid = c->sid[0];
2006         } else {
2007                 *out_sid = SECINITSID_PORT;
2008         }
2009
2010 out:
2011         read_unlock(&policy_rwlock);
2012         return rc;
2013 }
2014
2015 /**
2016  * security_netif_sid - Obtain the SID for a network interface.
2017  * @name: interface name
2018  * @if_sid: interface SID
2019  */
2020 int security_netif_sid(char *name, u32 *if_sid)
2021 {
2022         int rc = 0;
2023         struct ocontext *c;
2024
2025         read_lock(&policy_rwlock);
2026
2027         c = policydb.ocontexts[OCON_NETIF];
2028         while (c) {
2029                 if (strcmp(name, c->u.name) == 0)
2030                         break;
2031                 c = c->next;
2032         }
2033
2034         if (c) {
2035                 if (!c->sid[0] || !c->sid[1]) {
2036                         rc = sidtab_context_to_sid(&sidtab,
2037                                                   &c->context[0],
2038                                                   &c->sid[0]);
2039                         if (rc)
2040                                 goto out;
2041                         rc = sidtab_context_to_sid(&sidtab,
2042                                                    &c->context[1],
2043                                                    &c->sid[1]);
2044                         if (rc)
2045                                 goto out;
2046                 }
2047                 *if_sid = c->sid[0];
2048         } else
2049                 *if_sid = SECINITSID_NETIF;
2050
2051 out:
2052         read_unlock(&policy_rwlock);
2053         return rc;
2054 }
2055
2056 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2057 {
2058         int i, fail = 0;
2059
2060         for (i = 0; i < 4; i++)
2061                 if (addr[i] != (input[i] & mask[i])) {
2062                         fail = 1;
2063                         break;
2064                 }
2065
2066         return !fail;
2067 }
2068
2069 /**
2070  * security_node_sid - Obtain the SID for a node (host).
2071  * @domain: communication domain aka address family
2072  * @addrp: address
2073  * @addrlen: address length in bytes
2074  * @out_sid: security identifier
2075  */
2076 int security_node_sid(u16 domain,
2077                       void *addrp,
2078                       u32 addrlen,
2079                       u32 *out_sid)
2080 {
2081         int rc;
2082         struct ocontext *c;
2083
2084         read_lock(&policy_rwlock);
2085
2086         switch (domain) {
2087         case AF_INET: {
2088                 u32 addr;
2089
2090                 rc = -EINVAL;
2091                 if (addrlen != sizeof(u32))
2092                         goto out;
2093
2094                 addr = *((u32 *)addrp);
2095
2096                 c = policydb.ocontexts[OCON_NODE];
2097                 while (c) {
2098                         if (c->u.node.addr == (addr & c->u.node.mask))
2099                                 break;
2100                         c = c->next;
2101                 }
2102                 break;
2103         }
2104
2105         case AF_INET6:
2106                 rc = -EINVAL;
2107                 if (addrlen != sizeof(u64) * 2)
2108                         goto out;
2109                 c = policydb.ocontexts[OCON_NODE6];
2110                 while (c) {
2111                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2112                                                 c->u.node6.mask))
2113                                 break;
2114                         c = c->next;
2115                 }
2116                 break;
2117
2118         default:
2119                 rc = 0;
2120                 *out_sid = SECINITSID_NODE;
2121                 goto out;
2122         }
2123
2124         if (c) {
2125                 if (!c->sid[0]) {
2126                         rc = sidtab_context_to_sid(&sidtab,
2127                                                    &c->context[0],
2128                                                    &c->sid[0]);
2129                         if (rc)
2130                                 goto out;
2131                 }
2132                 *out_sid = c->sid[0];
2133         } else {
2134                 *out_sid = SECINITSID_NODE;
2135         }
2136
2137         rc = 0;
2138 out:
2139         read_unlock(&policy_rwlock);
2140         return rc;
2141 }
2142
2143 #define SIDS_NEL 25
2144
2145 /**
2146  * security_get_user_sids - Obtain reachable SIDs for a user.
2147  * @fromsid: starting SID
2148  * @username: username
2149  * @sids: array of reachable SIDs for user
2150  * @nel: number of elements in @sids
2151  *
2152  * Generate the set of SIDs for legal security contexts
2153  * for a given user that can be reached by @fromsid.
2154  * Set *@sids to point to a dynamically allocated
2155  * array containing the set of SIDs.  Set *@nel to the
2156  * number of elements in the array.
2157  */
2158
2159 int security_get_user_sids(u32 fromsid,
2160                            char *username,
2161                            u32 **sids,
2162                            u32 *nel)
2163 {
2164         struct context *fromcon, usercon;
2165         u32 *mysids = NULL, *mysids2, sid;
2166         u32 mynel = 0, maxnel = SIDS_NEL;
2167         struct user_datum *user;
2168         struct role_datum *role;
2169         struct ebitmap_node *rnode, *tnode;
2170         int rc = 0, i, j;
2171
2172         *sids = NULL;
2173         *nel = 0;
2174
2175         if (!ss_initialized)
2176                 goto out;
2177
2178         read_lock(&policy_rwlock);
2179
2180         context_init(&usercon);
2181
2182         rc = -EINVAL;
2183         fromcon = sidtab_search(&sidtab, fromsid);
2184         if (!fromcon)
2185                 goto out_unlock;
2186
2187         rc = -EINVAL;
2188         user = hashtab_search(policydb.p_users.table, username);
2189         if (!user)
2190                 goto out_unlock;
2191
2192         usercon.user = user->value;
2193
2194         rc = -ENOMEM;
2195         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
2196         if (!mysids)
2197                 goto out_unlock;
2198
2199         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2200                 role = policydb.role_val_to_struct[i];
2201                 usercon.role = i + 1;
2202                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2203                         usercon.type = j + 1;
2204
2205                         if (mls_setup_user_range(fromcon, user, &usercon))
2206                                 continue;
2207
2208                         rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
2209                         if (rc)
2210                                 goto out_unlock;
2211                         if (mynel < maxnel) {
2212                                 mysids[mynel++] = sid;
2213                         } else {
2214                                 rc = -ENOMEM;
2215                                 maxnel += SIDS_NEL;
2216                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2217                                 if (!mysids2)
2218                                         goto out_unlock;
2219                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2220                                 kfree(mysids);
2221                                 mysids = mysids2;
2222                                 mysids[mynel++] = sid;
2223                         }
2224                 }
2225         }
2226         rc = 0;
2227 out_unlock:
2228         read_unlock(&policy_rwlock);
2229         if (rc || !mynel) {
2230                 kfree(mysids);
2231                 goto out;
2232         }
2233
2234         rc = -ENOMEM;
2235         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2236         if (!mysids2) {
2237                 kfree(mysids);
2238                 goto out;
2239         }
2240         for (i = 0, j = 0; i < mynel; i++) {
2241                 struct av_decision dummy_avd;
2242                 rc = avc_has_perm_noaudit(fromsid, mysids[i],
2243                                           SECCLASS_PROCESS, /* kernel value */
2244                                           PROCESS__TRANSITION, AVC_STRICT,
2245                                           &dummy_avd);
2246                 if (!rc)
2247                         mysids2[j++] = mysids[i];
2248                 cond_resched();
2249         }
2250         rc = 0;
2251         kfree(mysids);
2252         *sids = mysids2;
2253         *nel = j;
2254 out:
2255         return rc;
2256 }
2257
2258 /**
2259  * security_genfs_sid - Obtain a SID for a file in a filesystem
2260  * @fstype: filesystem type
2261  * @path: path from root of mount
2262  * @sclass: file security class
2263  * @sid: SID for path
2264  *
2265  * Obtain a SID to use for a file in a filesystem that
2266  * cannot support xattr or use a fixed labeling behavior like
2267  * transition SIDs or task SIDs.
2268  */
2269 int security_genfs_sid(const char *fstype,
2270                        char *path,
2271                        u16 orig_sclass,
2272                        u32 *sid)
2273 {
2274         int len;
2275         u16 sclass;
2276         struct genfs *genfs;
2277         struct ocontext *c;
2278         int rc, cmp = 0;
2279
2280         while (path[0] == '/' && path[1] == '/')
2281                 path++;
2282
2283         read_lock(&policy_rwlock);
2284
2285         sclass = unmap_class(orig_sclass);
2286         *sid = SECINITSID_UNLABELED;
2287
2288         for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
2289                 cmp = strcmp(fstype, genfs->fstype);
2290                 if (cmp <= 0)
2291                         break;
2292         }
2293
2294         rc = -ENOENT;
2295         if (!genfs || cmp)
2296                 goto out;
2297
2298         for (c = genfs->head; c; c = c->next) {
2299                 len = strlen(c->u.name);
2300                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2301                     (strncmp(c->u.name, path, len) == 0))
2302                         break;
2303         }
2304
2305         rc = -ENOENT;
2306         if (!c)
2307                 goto out;
2308
2309         if (!c->sid[0]) {
2310                 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]);
2311                 if (rc)
2312                         goto out;
2313         }
2314
2315         *sid = c->sid[0];
2316         rc = 0;
2317 out:
2318         read_unlock(&policy_rwlock);
2319         return rc;
2320 }
2321
2322 /**
2323  * security_fs_use - Determine how to handle labeling for a filesystem.
2324  * @fstype: filesystem type
2325  * @behavior: labeling behavior
2326  * @sid: SID for filesystem (superblock)
2327  */
2328 int security_fs_use(
2329         const char *fstype,
2330         unsigned int *behavior,
2331         u32 *sid)
2332 {
2333         int rc = 0;
2334         struct ocontext *c;
2335
2336         read_lock(&policy_rwlock);
2337
2338         c = policydb.ocontexts[OCON_FSUSE];
2339         while (c) {
2340                 if (strcmp(fstype, c->u.name) == 0)
2341                         break;
2342                 c = c->next;
2343         }
2344
2345         if (c) {
2346                 *behavior = c->v.behavior;
2347                 if (!c->sid[0]) {
2348                         rc = sidtab_context_to_sid(&sidtab, &c->context[0],
2349                                                    &c->sid[0]);
2350                         if (rc)
2351                                 goto out;
2352                 }
2353                 *sid = c->sid[0];
2354         } else {
2355                 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
2356                 if (rc) {
2357                         *behavior = SECURITY_FS_USE_NONE;
2358                         rc = 0;
2359                 } else {
2360                         *behavior = SECURITY_FS_USE_GENFS;
2361                 }
2362         }
2363
2364 out:
2365         read_unlock(&policy_rwlock);
2366         return rc;
2367 }
2368
2369 int security_get_bools(int *len, char ***names, int **values)
2370 {
2371         int i, rc;
2372
2373         read_lock(&policy_rwlock);
2374         *names = NULL;
2375         *values = NULL;
2376
2377         rc = 0;
2378         *len = policydb.p_bools.nprim;
2379         if (!*len)
2380                 goto out;
2381
2382         rc = -ENOMEM;
2383         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
2384         if (!*names)
2385                 goto err;
2386
2387         rc = -ENOMEM;
2388         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
2389         if (!*values)
2390                 goto err;
2391
2392         for (i = 0; i < *len; i++) {
2393                 size_t name_len;
2394
2395                 (*values)[i] = policydb.bool_val_to_struct[i]->state;
2396                 name_len = strlen(sym_name(&policydb, SYM_BOOLS, i)) + 1;
2397
2398                 rc = -ENOMEM;
2399                 (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
2400                 if (!(*names)[i])
2401                         goto err;
2402
2403                 strncpy((*names)[i], sym_name(&policydb, SYM_BOOLS, i), name_len);
2404                 (*names)[i][name_len - 1] = 0;
2405         }
2406         rc = 0;
2407 out:
2408         read_unlock(&policy_rwlock);
2409         return rc;
2410 err:
2411         if (*names) {
2412                 for (i = 0; i < *len; i++)
2413                         kfree((*names)[i]);
2414         }
2415         kfree(*values);
2416         goto out;
2417 }
2418
2419
2420 int security_set_bools(int len, int *values)
2421 {
2422         int i, rc;
2423         int lenp, seqno = 0;
2424         struct cond_node *cur;
2425
2426         write_lock_irq(&policy_rwlock);
2427
2428         rc = -EFAULT;
2429         lenp = policydb.p_bools.nprim;
2430         if (len != lenp)
2431                 goto out;
2432
2433         for (i = 0; i < len; i++) {
2434                 if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
2435                         audit_log(current->audit_context, GFP_ATOMIC,
2436                                 AUDIT_MAC_CONFIG_CHANGE,
2437                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
2438                                 sym_name(&policydb, SYM_BOOLS, i),
2439                                 !!values[i],
2440                                 policydb.bool_val_to_struct[i]->state,
2441                                 audit_get_loginuid(current),
2442                                 audit_get_sessionid(current));
2443                 }
2444                 if (values[i])
2445                         policydb.bool_val_to_struct[i]->state = 1;
2446                 else
2447                         policydb.bool_val_to_struct[i]->state = 0;
2448         }
2449
2450         for (cur = policydb.cond_list; cur; cur = cur->next) {
2451                 rc = evaluate_cond_node(&policydb, cur);
2452                 if (rc)
2453                         goto out;
2454         }
2455
2456         seqno = ++latest_granting;
2457         rc = 0;
2458 out:
2459         write_unlock_irq(&policy_rwlock);
2460         if (!rc) {
2461                 avc_ss_reset(seqno);
2462                 selnl_notify_policyload(seqno);
2463                 selinux_status_update_policyload(seqno);
2464                 selinux_xfrm_notify_policyload();
2465         }
2466         return rc;
2467 }
2468
2469 int security_get_bool_value(int bool)
2470 {
2471         int rc;
2472         int len;
2473
2474         read_lock(&policy_rwlock);
2475
2476         rc = -EFAULT;
2477         len = policydb.p_bools.nprim;
2478         if (bool >= len)
2479                 goto out;
2480
2481         rc = policydb.bool_val_to_struct[bool]->state;
2482 out:
2483         read_unlock(&policy_rwlock);
2484         return rc;
2485 }
2486
2487 static int security_preserve_bools(struct policydb *p)
2488 {
2489         int rc, nbools = 0, *bvalues = NULL, i;
2490         char **bnames = NULL;
2491         struct cond_bool_datum *booldatum;
2492         struct cond_node *cur;
2493
2494         rc = security_get_bools(&nbools, &bnames, &bvalues);
2495         if (rc)
2496                 goto out;
2497         for (i = 0; i < nbools; i++) {
2498                 booldatum = hashtab_search(p->p_bools.table, bnames[i]);
2499                 if (booldatum)
2500                         booldatum->state = bvalues[i];
2501         }
2502         for (cur = p->cond_list; cur; cur = cur->next) {
2503                 rc = evaluate_cond_node(p, cur);
2504                 if (rc)
2505                         goto out;
2506         }
2507
2508 out:
2509         if (bnames) {
2510                 for (i = 0; i < nbools; i++)
2511                         kfree(bnames[i]);
2512         }
2513         kfree(bnames);
2514         kfree(bvalues);
2515         return rc;
2516 }
2517
2518 /*
2519  * security_sid_mls_copy() - computes a new sid based on the given
2520  * sid and the mls portion of mls_sid.
2521  */
2522 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
2523 {
2524         struct context *context1;
2525         struct context *context2;
2526         struct context newcon;
2527         char *s;
2528         u32 len;
2529         int rc;
2530
2531         rc = 0;
2532         if (!ss_initialized || !policydb.mls_enabled) {
2533                 *new_sid = sid;
2534                 goto out;
2535         }
2536
2537         context_init(&newcon);
2538
2539         read_lock(&policy_rwlock);
2540
2541         rc = -EINVAL;
2542         context1 = sidtab_search(&sidtab, sid);
2543         if (!context1) {
2544                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2545                         __func__, sid);
2546                 goto out_unlock;
2547         }
2548
2549         rc = -EINVAL;
2550         context2 = sidtab_search(&sidtab, mls_sid);
2551         if (!context2) {
2552                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2553                         __func__, mls_sid);
2554                 goto out_unlock;
2555         }
2556
2557         newcon.user = context1->user;
2558         newcon.role = context1->role;
2559         newcon.type = context1->type;
2560         rc = mls_context_cpy(&newcon, context2);
2561         if (rc)
2562                 goto out_unlock;
2563
2564         /* Check the validity of the new context. */
2565         if (!policydb_context_isvalid(&policydb, &newcon)) {
2566                 rc = convert_context_handle_invalid_context(&newcon);
2567                 if (rc) {
2568                         if (!context_struct_to_string(&newcon, &s, &len)) {
2569                                 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2570                                           "security_sid_mls_copy: invalid context %s", s);
2571                                 kfree(s);
2572                         }
2573                         goto out_unlock;
2574                 }
2575         }
2576
2577         rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2578 out_unlock:
2579         read_unlock(&policy_rwlock);
2580         context_destroy(&newcon);
2581 out:
2582         return rc;
2583 }
2584
2585 /**
2586  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
2587  * @nlbl_sid: NetLabel SID
2588  * @nlbl_type: NetLabel labeling protocol type
2589  * @xfrm_sid: XFRM SID
2590  *
2591  * Description:
2592  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
2593  * resolved into a single SID it is returned via @peer_sid and the function
2594  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
2595  * returns a negative value.  A table summarizing the behavior is below:
2596  *
2597  *                                 | function return |      @sid
2598  *   ------------------------------+-----------------+-----------------
2599  *   no peer labels                |        0        |    SECSID_NULL
2600  *   single peer label             |        0        |    <peer_label>
2601  *   multiple, consistent labels   |        0        |    <peer_label>
2602  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
2603  *
2604  */
2605 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
2606                                  u32 xfrm_sid,
2607                                  u32 *peer_sid)
2608 {
2609         int rc;
2610         struct context *nlbl_ctx;
2611         struct context *xfrm_ctx;
2612
2613         *peer_sid = SECSID_NULL;
2614
2615         /* handle the common (which also happens to be the set of easy) cases
2616          * right away, these two if statements catch everything involving a
2617          * single or absent peer SID/label */
2618         if (xfrm_sid == SECSID_NULL) {
2619                 *peer_sid = nlbl_sid;
2620                 return 0;
2621         }
2622         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
2623          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
2624          * is present */
2625         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
2626                 *peer_sid = xfrm_sid;
2627                 return 0;
2628         }
2629
2630         /* we don't need to check ss_initialized here since the only way both
2631          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
2632          * security server was initialized and ss_initialized was true */
2633         if (!policydb.mls_enabled)
2634                 return 0;
2635
2636         read_lock(&policy_rwlock);
2637
2638         rc = -EINVAL;
2639         nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
2640         if (!nlbl_ctx) {
2641                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2642                        __func__, nlbl_sid);
2643                 goto out;
2644         }
2645         rc = -EINVAL;
2646         xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
2647         if (!xfrm_ctx) {
2648                 printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
2649                        __func__, xfrm_sid);
2650                 goto out;
2651         }
2652         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
2653         if (rc)
2654                 goto out;
2655
2656         /* at present NetLabel SIDs/labels really only carry MLS
2657          * information so if the MLS portion of the NetLabel SID
2658          * matches the MLS portion of the labeled XFRM SID/label
2659          * then pass along the XFRM SID as it is the most
2660          * expressive */
2661         *peer_sid = xfrm_sid;
2662 out:
2663         read_unlock(&policy_rwlock);
2664         return rc;
2665 }
2666
2667 static int get_classes_callback(void *k, void *d, void *args)
2668 {
2669         struct class_datum *datum = d;
2670         char *name = k, **classes = args;
2671         int value = datum->value - 1;
2672
2673         classes[value] = kstrdup(name, GFP_ATOMIC);
2674         if (!classes[value])
2675                 return -ENOMEM;
2676
2677         return 0;
2678 }
2679
2680 int security_get_classes(char ***classes, int *nclasses)
2681 {
2682         int rc;
2683
2684         read_lock(&policy_rwlock);
2685
2686         rc = -ENOMEM;
2687         *nclasses = policydb.p_classes.nprim;
2688         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
2689         if (!*classes)
2690                 goto out;
2691
2692         rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2693                         *classes);
2694         if (rc) {
2695                 int i;
2696                 for (i = 0; i < *nclasses; i++)
2697                         kfree((*classes)[i]);
2698                 kfree(*classes);
2699         }
2700
2701 out:
2702         read_unlock(&policy_rwlock);
2703         return rc;
2704 }
2705
2706 static int get_permissions_callback(void *k, void *d, void *args)
2707 {
2708         struct perm_datum *datum = d;
2709         char *name = k, **perms = args;
2710         int value = datum->value - 1;
2711
2712         perms[value] = kstrdup(name, GFP_ATOMIC);
2713         if (!perms[value])
2714                 return -ENOMEM;
2715
2716         return 0;
2717 }
2718
2719 int security_get_permissions(char *class, char ***perms, int *nperms)
2720 {
2721         int rc, i;
2722         struct class_datum *match;
2723
2724         read_lock(&policy_rwlock);
2725
2726         rc = -EINVAL;
2727         match = hashtab_search(policydb.p_classes.table, class);
2728         if (!match) {
2729                 printk(KERN_ERR "SELinux: %s:  unrecognized class %s\n",
2730                         __func__, class);
2731                 goto out;
2732         }
2733
2734         rc = -ENOMEM;
2735         *nperms = match->permissions.nprim;
2736         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
2737         if (!*perms)
2738                 goto out;
2739
2740         if (match->comdatum) {
2741                 rc = hashtab_map(match->comdatum->permissions.table,
2742                                 get_permissions_callback, *perms);
2743                 if (rc)
2744                         goto err;
2745         }
2746
2747         rc = hashtab_map(match->permissions.table, get_permissions_callback,
2748                         *perms);
2749         if (rc)
2750                 goto err;
2751
2752 out:
2753         read_unlock(&policy_rwlock);
2754         return rc;
2755
2756 err:
2757         read_unlock(&policy_rwlock);
2758         for (i = 0; i < *nperms; i++)
2759                 kfree((*perms)[i]);
2760         kfree(*perms);
2761         return rc;
2762 }
2763
2764 int security_get_reject_unknown(void)
2765 {
2766         return policydb.reject_unknown;
2767 }
2768
2769 int security_get_allow_unknown(void)
2770 {
2771         return policydb.allow_unknown;
2772 }
2773
2774 /**
2775  * security_policycap_supported - Check for a specific policy capability
2776  * @req_cap: capability
2777  *
2778  * Description:
2779  * This function queries the currently loaded policy to see if it supports the
2780  * capability specified by @req_cap.  Returns true (1) if the capability is
2781  * supported, false (0) if it isn't supported.
2782  *
2783  */
2784 int security_policycap_supported(unsigned int req_cap)
2785 {
2786         int rc;
2787
2788         read_lock(&policy_rwlock);
2789         rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
2790         read_unlock(&policy_rwlock);
2791
2792         return rc;
2793 }
2794
2795 struct selinux_audit_rule {
2796         u32 au_seqno;
2797         struct context au_ctxt;
2798 };
2799
2800 void selinux_audit_rule_free(void *vrule)
2801 {
2802         struct selinux_audit_rule *rule = vrule;
2803
2804         if (rule) {
2805                 context_destroy(&rule->au_ctxt);
2806                 kfree(rule);
2807         }
2808 }
2809
2810 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2811 {
2812         struct selinux_audit_rule *tmprule;
2813         struct role_datum *roledatum;
2814         struct type_datum *typedatum;
2815         struct user_datum *userdatum;
2816         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
2817         int rc = 0;
2818
2819         *rule = NULL;
2820
2821         if (!ss_initialized)
2822                 return -EOPNOTSUPP;
2823
2824         switch (field) {
2825         case AUDIT_SUBJ_USER:
2826         case AUDIT_SUBJ_ROLE:
2827         case AUDIT_SUBJ_TYPE:
2828         case AUDIT_OBJ_USER:
2829         case AUDIT_OBJ_ROLE:
2830         case AUDIT_OBJ_TYPE:
2831                 /* only 'equals' and 'not equals' fit user, role, and type */
2832                 if (op != Audit_equal && op != Audit_not_equal)
2833                         return -EINVAL;
2834                 break;
2835         case AUDIT_SUBJ_SEN:
2836         case AUDIT_SUBJ_CLR:
2837         case AUDIT_OBJ_LEV_LOW:
2838         case AUDIT_OBJ_LEV_HIGH:
2839                 /* we do not allow a range, indicated by the presence of '-' */
2840                 if (strchr(rulestr, '-'))
2841                         return -EINVAL;
2842                 break;
2843         default:
2844                 /* only the above fields are valid */
2845                 return -EINVAL;
2846         }
2847
2848         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2849         if (!tmprule)
2850                 return -ENOMEM;
2851
2852         context_init(&tmprule->au_ctxt);
2853
2854         read_lock(&policy_rwlock);
2855
2856         tmprule->au_seqno = latest_granting;
2857
2858         switch (field) {
2859         case AUDIT_SUBJ_USER:
2860         case AUDIT_OBJ_USER:
2861                 rc = -EINVAL;
2862                 userdatum = hashtab_search(policydb.p_users.table, rulestr);
2863                 if (!userdatum)
2864                         goto out;
2865                 tmprule->au_ctxt.user = userdatum->value;
2866                 break;
2867         case AUDIT_SUBJ_ROLE:
2868         case AUDIT_OBJ_ROLE:
2869                 rc = -EINVAL;
2870                 roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2871                 if (!roledatum)
2872                         goto out;
2873                 tmprule->au_ctxt.role = roledatum->value;
2874                 break;
2875         case AUDIT_SUBJ_TYPE:
2876         case AUDIT_OBJ_TYPE:
2877                 rc = -EINVAL;
2878                 typedatum = hashtab_search(policydb.p_types.table, rulestr);
2879                 if (!typedatum)
2880                         goto out;
2881                 tmprule->au_ctxt.type = typedatum->value;
2882                 break;
2883         case AUDIT_SUBJ_SEN:
2884         case AUDIT_SUBJ_CLR:
2885         case AUDIT_OBJ_LEV_LOW:
2886         case AUDIT_OBJ_LEV_HIGH:
2887                 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2888                 if (rc)
2889                         goto out;
2890                 break;
2891         }
2892         rc = 0;
2893 out:
2894         read_unlock(&policy_rwlock);
2895
2896         if (rc) {
2897                 selinux_audit_rule_free(tmprule);
2898                 tmprule = NULL;
2899         }
2900
2901         *rule = tmprule;
2902
2903         return rc;
2904 }
2905
2906 /* Check to see if the rule contains any selinux fields */
2907 int selinux_audit_rule_known(struct audit_krule *rule)
2908 {
2909         int i;
2910
2911         for (i = 0; i < rule->field_count; i++) {
2912                 struct audit_field *f = &rule->fields[i];
2913                 switch (f->type) {
2914                 case AUDIT_SUBJ_USER:
2915                 case AUDIT_SUBJ_ROLE:
2916                 case AUDIT_SUBJ_TYPE:
2917                 case AUDIT_SUBJ_SEN:
2918                 case AUDIT_SUBJ_CLR:
2919                 case AUDIT_OBJ_USER:
2920                 case AUDIT_OBJ_ROLE:
2921                 case AUDIT_OBJ_TYPE:
2922                 case AUDIT_OBJ_LEV_LOW:
2923                 case AUDIT_OBJ_LEV_HIGH:
2924                         return 1;
2925                 }
2926         }
2927
2928         return 0;
2929 }
2930
2931 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
2932                              struct audit_context *actx)
2933 {
2934         struct context *ctxt;
2935         struct mls_level *level;
2936         struct selinux_audit_rule *rule = vrule;
2937         int match = 0;
2938
2939         if (!rule) {
2940                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2941                           "selinux_audit_rule_match: missing rule\n");
2942                 return -ENOENT;
2943         }
2944
2945         read_lock(&policy_rwlock);
2946
2947         if (rule->au_seqno < latest_granting) {
2948                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2949                           "selinux_audit_rule_match: stale rule\n");
2950                 match = -ESTALE;
2951                 goto out;
2952         }
2953
2954         ctxt = sidtab_search(&sidtab, sid);
2955         if (!ctxt) {
2956                 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2957                           "selinux_audit_rule_match: unrecognized SID %d\n",
2958                           sid);
2959                 match = -ENOENT;
2960                 goto out;
2961         }
2962
2963         /* a field/op pair that is not caught here will simply fall through
2964            without a match */
2965         switch (field) {
2966         case AUDIT_SUBJ_USER:
2967         case AUDIT_OBJ_USER:
2968                 switch (op) {
2969                 case Audit_equal:
2970                         match = (ctxt->user == rule->au_ctxt.user);
2971                         break;
2972                 case Audit_not_equal:
2973                         match = (ctxt->user != rule->au_ctxt.user);
2974                         break;
2975                 }
2976                 break;
2977         case AUDIT_SUBJ_ROLE:
2978         case AUDIT_OBJ_ROLE:
2979                 switch (op) {
2980                 case Audit_equal:
2981                         match = (ctxt->role == rule->au_ctxt.role);
2982                         break;
2983                 case Audit_not_equal:
2984                         match = (ctxt->role != rule->au_ctxt.role);
2985                         break;
2986                 }
2987                 break;
2988         case AUDIT_SUBJ_TYPE:
2989         case AUDIT_OBJ_TYPE:
2990                 switch (op) {
2991                 case Audit_equal:
2992                         match = (ctxt->type == rule->au_ctxt.type);
2993                         break;
2994                 case Audit_not_equal:
2995                         match = (ctxt->type != rule->au_ctxt.type);
2996                         break;
2997                 }
2998                 break;
2999         case AUDIT_SUBJ_SEN:
3000         case AUDIT_SUBJ_CLR:
3001         case AUDIT_OBJ_LEV_LOW:
3002         case AUDIT_OBJ_LEV_HIGH:
3003                 level = ((field == AUDIT_SUBJ_SEN ||
3004                           field == AUDIT_OBJ_LEV_LOW) ?
3005                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3006                 switch (op) {
3007                 case Audit_equal:
3008                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3009                                              level);
3010                         break;
3011                 case Audit_not_equal:
3012                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3013                                               level);
3014                         break;
3015                 case Audit_lt:
3016                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3017                                                level) &&
3018                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3019                                                level));
3020                         break;
3021                 case Audit_le:
3022                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3023                                               level);
3024                         break;
3025                 case Audit_gt:
3026                         match = (mls_level_dom(level,
3027                                               &rule->au_ctxt.range.level[0]) &&
3028                                  !mls_level_eq(level,
3029                                                &rule->au_ctxt.range.level[0]));
3030                         break;
3031                 case Audit_ge:
3032                         match = mls_level_dom(level,
3033                                               &rule->au_ctxt.range.level[0]);
3034                         break;
3035                 }
3036         }
3037
3038 out:
3039         read_unlock(&policy_rwlock);
3040         return match;
3041 }
3042
3043 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3044
3045 static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
3046                                u16 class, u32 perms, u32 *retained)
3047 {
3048         int err = 0;
3049
3050         if (event == AVC_CALLBACK_RESET && aurule_callback)
3051                 err = aurule_callback();
3052         return err;
3053 }
3054
3055 static int __init aurule_init(void)
3056 {
3057         int err;
3058
3059         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
3060                                SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
3061         if (err)
3062                 panic("avc_add_callback() failed, error %d\n", err);
3063
3064         return err;
3065 }
3066 __initcall(aurule_init);
3067
3068 #ifdef CONFIG_NETLABEL
3069 /**
3070  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3071  * @secattr: the NetLabel packet security attributes
3072  * @sid: the SELinux SID
3073  *
3074  * Description:
3075  * Attempt to cache the context in @ctx, which was derived from the packet in
3076  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3077  * already been initialized.
3078  *
3079  */
3080 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3081                                       u32 sid)
3082 {
3083         u32 *sid_cache;
3084
3085         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3086         if (sid_cache == NULL)
3087                 return;
3088         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3089         if (secattr->cache == NULL) {
3090                 kfree(sid_cache);
3091                 return;
3092         }
3093
3094         *sid_cache = sid;
3095         secattr->cache->free = kfree;
3096         secattr->cache->data = sid_cache;
3097         secattr->flags |= NETLBL_SECATTR_CACHE;
3098 }
3099
3100 /**
3101  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3102  * @secattr: the NetLabel packet security attributes
3103  * @sid: the SELinux SID
3104  *
3105  * Description:
3106  * Convert the given NetLabel security attributes in @secattr into a
3107  * SELinux SID.  If the @secattr field does not contain a full SELinux
3108  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3109  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3110  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3111  * conversion for future lookups.  Returns zero on success, negative values on
3112  * failure.
3113  *
3114  */
3115 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
3116                                    u32 *sid)
3117 {
3118         int rc;
3119         struct context *ctx;
3120         struct context ctx_new;
3121
3122         if (!ss_initialized) {
3123                 *sid = SECSID_NULL;
3124                 return 0;
3125         }
3126
3127         read_lock(&policy_rwlock);
3128
3129         if (secattr->flags & NETLBL_SECATTR_CACHE)
3130                 *sid = *(u32 *)secattr->cache->data;
3131         else if (secattr->flags & NETLBL_SECATTR_SECID)
3132                 *sid = secattr->attr.secid;
3133         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3134                 rc = -EIDRM;
3135                 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
3136                 if (ctx == NULL)
3137                         goto out;
3138
3139                 context_init(&ctx_new);
3140                 ctx_new.user = ctx->user;
3141                 ctx_new.role = ctx->role;
3142                 ctx_new.type = ctx->type;
3143                 mls_import_netlbl_lvl(&ctx_new, secattr);
3144                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3145                         rc = ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
3146                                                    secattr->attr.mls.cat);
3147                         if (rc)
3148                                 goto out;
3149                         memcpy(&ctx_new.range.level[1].cat,
3150                                &ctx_new.range.level[0].cat,
3151                                sizeof(ctx_new.range.level[0].cat));
3152                 }
3153                 rc = -EIDRM;
3154                 if (!mls_context_isvalid(&policydb, &ctx_new))
3155                         goto out_free;
3156
3157                 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
3158                 if (rc)
3159                         goto out_free;
3160
3161                 security_netlbl_cache_add(secattr, *sid);
3162
3163                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3164         } else
3165                 *sid = SECSID_NULL;
3166
3167         read_unlock(&policy_rwlock);
3168         return 0;
3169 out_free:
3170         ebitmap_destroy(&ctx_new.range.level[0].cat);
3171 out:
3172         read_unlock(&policy_rwlock);
3173         return rc;
3174 }
3175
3176 /**
3177  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3178  * @sid: the SELinux SID
3179  * @secattr: the NetLabel packet security attributes
3180  *
3181  * Description:
3182  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3183  * Returns zero on success, negative values on failure.
3184  *
3185  */
3186 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
3187 {
3188         int rc;
3189         struct context *ctx;
3190
3191         if (!ss_initialized)
3192                 return 0;
3193
3194         read_lock(&policy_rwlock);
3195
3196         rc = -ENOENT;
3197         ctx = sidtab_search(&sidtab, sid);
3198         if (ctx == NULL)
3199                 goto out;
3200
3201         rc = -ENOMEM;
3202         secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1),
3203                                   GFP_ATOMIC);
3204         if (secattr->domain == NULL)
3205                 goto out;
3206
3207         secattr->attr.secid = sid;
3208         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3209         mls_export_netlbl_lvl(ctx, secattr);
3210         rc = mls_export_netlbl_cat(ctx, secattr);
3211 out:
3212         read_unlock(&policy_rwlock);
3213         return rc;
3214 }
3215 #endif /* CONFIG_NETLABEL */
3216
3217 /**
3218  * security_read_policy - read the policy.
3219  * @data: binary policy data
3220  * @len: length of data in bytes
3221  *
3222  */
3223 int security_read_policy(void **data, size_t *len)
3224 {
3225         int rc;
3226         struct policy_file fp;
3227
3228         if (!ss_initialized)
3229                 return -EINVAL;
3230
3231         *len = security_policydb_len();
3232
3233         *data = vmalloc_user(*len);
3234         if (!*data)
3235                 return -ENOMEM;
3236
3237         fp.data = *data;
3238         fp.len = *len;
3239
3240         read_lock(&policy_rwlock);
3241         rc = policydb_write(&policydb, &fp);
3242         read_unlock(&policy_rwlock);
3243
3244         if (rc)
3245                 return rc;
3246
3247         *len = (unsigned long)fp.data - (unsigned long)*data;
3248         return 0;
3249
3250 }