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