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