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 * 11 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 12 * 13 * Added conditional policy language extensions 14 * 15 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. 16 * Copyright (C) 2003 - 2004 Tresys Technology, LLC 17 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 18 * This program is free software; you can redistribute it and/or modify 19 * it under the terms of the GNU General Public License as published by 20 * the Free Software Foundation, version 2. 21 */ 22 #include <linux/kernel.h> 23 #include <linux/slab.h> 24 #include <linux/string.h> 25 #include <linux/spinlock.h> 26 #include <linux/errno.h> 27 #include <linux/in.h> 28 #include <linux/sched.h> 29 #include <linux/audit.h> 30 #include <asm/semaphore.h> 31 #include "flask.h" 32 #include "avc.h" 33 #include "avc_ss.h" 34 #include "security.h" 35 #include "context.h" 36 #include "policydb.h" 37 #include "sidtab.h" 38 #include "services.h" 39 #include "conditional.h" 40 #include "mls.h" 41 42 extern void selnl_notify_policyload(u32 seqno); 43 unsigned int policydb_loaded_version; 44 45 static DEFINE_RWLOCK(policy_rwlock); 46 #define POLICY_RDLOCK read_lock(&policy_rwlock) 47 #define POLICY_WRLOCK write_lock_irq(&policy_rwlock) 48 #define POLICY_RDUNLOCK read_unlock(&policy_rwlock) 49 #define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock) 50 51 static DECLARE_MUTEX(load_sem); 52 #define LOAD_LOCK down(&load_sem) 53 #define LOAD_UNLOCK up(&load_sem) 54 55 static struct sidtab sidtab; 56 struct policydb policydb; 57 int ss_initialized = 0; 58 59 /* 60 * The largest sequence number that has been used when 61 * providing an access decision to the access vector cache. 62 * The sequence number only changes when a policy change 63 * occurs. 64 */ 65 static u32 latest_granting = 0; 66 67 /* Forward declaration. */ 68 static int context_struct_to_string(struct context *context, char **scontext, 69 u32 *scontext_len); 70 71 /* 72 * Return the boolean value of a constraint expression 73 * when it is applied to the specified source and target 74 * security contexts. 75 * 76 * xcontext is a special beast... It is used by the validatetrans rules 77 * only. For these rules, scontext is the context before the transition, 78 * tcontext is the context after the transition, and xcontext is the context 79 * of the process performing the transition. All other callers of 80 * constraint_expr_eval should pass in NULL for xcontext. 81 */ 82 static int constraint_expr_eval(struct context *scontext, 83 struct context *tcontext, 84 struct context *xcontext, 85 struct constraint_expr *cexpr) 86 { 87 u32 val1, val2; 88 struct context *c; 89 struct role_datum *r1, *r2; 90 struct mls_level *l1, *l2; 91 struct constraint_expr *e; 92 int s[CEXPR_MAXDEPTH]; 93 int sp = -1; 94 95 for (e = cexpr; e; e = e->next) { 96 switch (e->expr_type) { 97 case CEXPR_NOT: 98 BUG_ON(sp < 0); 99 s[sp] = !s[sp]; 100 break; 101 case CEXPR_AND: 102 BUG_ON(sp < 1); 103 sp--; 104 s[sp] &= s[sp+1]; 105 break; 106 case CEXPR_OR: 107 BUG_ON(sp < 1); 108 sp--; 109 s[sp] |= s[sp+1]; 110 break; 111 case CEXPR_ATTR: 112 if (sp == (CEXPR_MAXDEPTH-1)) 113 return 0; 114 switch (e->attr) { 115 case CEXPR_USER: 116 val1 = scontext->user; 117 val2 = tcontext->user; 118 break; 119 case CEXPR_TYPE: 120 val1 = scontext->type; 121 val2 = tcontext->type; 122 break; 123 case CEXPR_ROLE: 124 val1 = scontext->role; 125 val2 = tcontext->role; 126 r1 = policydb.role_val_to_struct[val1 - 1]; 127 r2 = policydb.role_val_to_struct[val2 - 1]; 128 switch (e->op) { 129 case CEXPR_DOM: 130 s[++sp] = ebitmap_get_bit(&r1->dominates, 131 val2 - 1); 132 continue; 133 case CEXPR_DOMBY: 134 s[++sp] = ebitmap_get_bit(&r2->dominates, 135 val1 - 1); 136 continue; 137 case CEXPR_INCOMP: 138 s[++sp] = ( !ebitmap_get_bit(&r1->dominates, 139 val2 - 1) && 140 !ebitmap_get_bit(&r2->dominates, 141 val1 - 1) ); 142 continue; 143 default: 144 break; 145 } 146 break; 147 case CEXPR_L1L2: 148 l1 = &(scontext->range.level[0]); 149 l2 = &(tcontext->range.level[0]); 150 goto mls_ops; 151 case CEXPR_L1H2: 152 l1 = &(scontext->range.level[0]); 153 l2 = &(tcontext->range.level[1]); 154 goto mls_ops; 155 case CEXPR_H1L2: 156 l1 = &(scontext->range.level[1]); 157 l2 = &(tcontext->range.level[0]); 158 goto mls_ops; 159 case CEXPR_H1H2: 160 l1 = &(scontext->range.level[1]); 161 l2 = &(tcontext->range.level[1]); 162 goto mls_ops; 163 case CEXPR_L1H1: 164 l1 = &(scontext->range.level[0]); 165 l2 = &(scontext->range.level[1]); 166 goto mls_ops; 167 case CEXPR_L2H2: 168 l1 = &(tcontext->range.level[0]); 169 l2 = &(tcontext->range.level[1]); 170 goto mls_ops; 171 mls_ops: 172 switch (e->op) { 173 case CEXPR_EQ: 174 s[++sp] = mls_level_eq(l1, l2); 175 continue; 176 case CEXPR_NEQ: 177 s[++sp] = !mls_level_eq(l1, l2); 178 continue; 179 case CEXPR_DOM: 180 s[++sp] = mls_level_dom(l1, l2); 181 continue; 182 case CEXPR_DOMBY: 183 s[++sp] = mls_level_dom(l2, l1); 184 continue; 185 case CEXPR_INCOMP: 186 s[++sp] = mls_level_incomp(l2, l1); 187 continue; 188 default: 189 BUG(); 190 return 0; 191 } 192 break; 193 default: 194 BUG(); 195 return 0; 196 } 197 198 switch (e->op) { 199 case CEXPR_EQ: 200 s[++sp] = (val1 == val2); 201 break; 202 case CEXPR_NEQ: 203 s[++sp] = (val1 != val2); 204 break; 205 default: 206 BUG(); 207 return 0; 208 } 209 break; 210 case CEXPR_NAMES: 211 if (sp == (CEXPR_MAXDEPTH-1)) 212 return 0; 213 c = scontext; 214 if (e->attr & CEXPR_TARGET) 215 c = tcontext; 216 else if (e->attr & CEXPR_XTARGET) { 217 c = xcontext; 218 if (!c) { 219 BUG(); 220 return 0; 221 } 222 } 223 if (e->attr & CEXPR_USER) 224 val1 = c->user; 225 else if (e->attr & CEXPR_ROLE) 226 val1 = c->role; 227 else if (e->attr & CEXPR_TYPE) 228 val1 = c->type; 229 else { 230 BUG(); 231 return 0; 232 } 233 234 switch (e->op) { 235 case CEXPR_EQ: 236 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 237 break; 238 case CEXPR_NEQ: 239 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 240 break; 241 default: 242 BUG(); 243 return 0; 244 } 245 break; 246 default: 247 BUG(); 248 return 0; 249 } 250 } 251 252 BUG_ON(sp != 0); 253 return s[0]; 254 } 255 256 /* 257 * Compute access vectors based on a context structure pair for 258 * the permissions in a particular class. 259 */ 260 static int context_struct_compute_av(struct context *scontext, 261 struct context *tcontext, 262 u16 tclass, 263 u32 requested, 264 struct av_decision *avd) 265 { 266 struct constraint_node *constraint; 267 struct role_allow *ra; 268 struct avtab_key avkey; 269 struct avtab_datum *avdatum; 270 struct class_datum *tclass_datum; 271 272 /* 273 * Remap extended Netlink classes for old policy versions. 274 * Do this here rather than socket_type_to_security_class() 275 * in case a newer policy version is loaded, allowing sockets 276 * to remain in the correct class. 277 */ 278 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) 279 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && 280 tclass <= SECCLASS_NETLINK_DNRT_SOCKET) 281 tclass = SECCLASS_NETLINK_SOCKET; 282 283 if (!tclass || tclass > policydb.p_classes.nprim) { 284 printk(KERN_ERR "security_compute_av: unrecognized class %d\n", 285 tclass); 286 return -EINVAL; 287 } 288 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 289 290 /* 291 * Initialize the access vectors to the default values. 292 */ 293 avd->allowed = 0; 294 avd->decided = 0xffffffff; 295 avd->auditallow = 0; 296 avd->auditdeny = 0xffffffff; 297 avd->seqno = latest_granting; 298 299 /* 300 * If a specific type enforcement rule was defined for 301 * this permission check, then use it. 302 */ 303 avkey.source_type = scontext->type; 304 avkey.target_type = tcontext->type; 305 avkey.target_class = tclass; 306 avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_AV); 307 if (avdatum) { 308 if (avdatum->specified & AVTAB_ALLOWED) 309 avd->allowed = avtab_allowed(avdatum); 310 if (avdatum->specified & AVTAB_AUDITDENY) 311 avd->auditdeny = avtab_auditdeny(avdatum); 312 if (avdatum->specified & AVTAB_AUDITALLOW) 313 avd->auditallow = avtab_auditallow(avdatum); 314 } 315 316 /* Check conditional av table for additional permissions */ 317 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd); 318 319 /* 320 * Remove any permissions prohibited by a constraint (this includes 321 * the MLS policy). 322 */ 323 constraint = tclass_datum->constraints; 324 while (constraint) { 325 if ((constraint->permissions & (avd->allowed)) && 326 !constraint_expr_eval(scontext, tcontext, NULL, 327 constraint->expr)) { 328 avd->allowed = (avd->allowed) & ~(constraint->permissions); 329 } 330 constraint = constraint->next; 331 } 332 333 /* 334 * If checking process transition permission and the 335 * role is changing, then check the (current_role, new_role) 336 * pair. 337 */ 338 if (tclass == SECCLASS_PROCESS && 339 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) && 340 scontext->role != tcontext->role) { 341 for (ra = policydb.role_allow; ra; ra = ra->next) { 342 if (scontext->role == ra->role && 343 tcontext->role == ra->new_role) 344 break; 345 } 346 if (!ra) 347 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION | 348 PROCESS__DYNTRANSITION); 349 } 350 351 return 0; 352 } 353 354 static int security_validtrans_handle_fail(struct context *ocontext, 355 struct context *ncontext, 356 struct context *tcontext, 357 u16 tclass) 358 { 359 char *o = NULL, *n = NULL, *t = NULL; 360 u32 olen, nlen, tlen; 361 362 if (context_struct_to_string(ocontext, &o, &olen) < 0) 363 goto out; 364 if (context_struct_to_string(ncontext, &n, &nlen) < 0) 365 goto out; 366 if (context_struct_to_string(tcontext, &t, &tlen) < 0) 367 goto out; 368 audit_log(current->audit_context, AUDIT_SELINUX_ERR, 369 "security_validate_transition: denied for" 370 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 371 o, n, t, policydb.p_class_val_to_name[tclass-1]); 372 out: 373 kfree(o); 374 kfree(n); 375 kfree(t); 376 377 if (!selinux_enforcing) 378 return 0; 379 return -EPERM; 380 } 381 382 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 383 u16 tclass) 384 { 385 struct context *ocontext; 386 struct context *ncontext; 387 struct context *tcontext; 388 struct class_datum *tclass_datum; 389 struct constraint_node *constraint; 390 int rc = 0; 391 392 if (!ss_initialized) 393 return 0; 394 395 POLICY_RDLOCK; 396 397 /* 398 * Remap extended Netlink classes for old policy versions. 399 * Do this here rather than socket_type_to_security_class() 400 * in case a newer policy version is loaded, allowing sockets 401 * to remain in the correct class. 402 */ 403 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) 404 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && 405 tclass <= SECCLASS_NETLINK_DNRT_SOCKET) 406 tclass = SECCLASS_NETLINK_SOCKET; 407 408 if (!tclass || tclass > policydb.p_classes.nprim) { 409 printk(KERN_ERR "security_validate_transition: " 410 "unrecognized class %d\n", tclass); 411 rc = -EINVAL; 412 goto out; 413 } 414 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 415 416 ocontext = sidtab_search(&sidtab, oldsid); 417 if (!ocontext) { 418 printk(KERN_ERR "security_validate_transition: " 419 " unrecognized SID %d\n", oldsid); 420 rc = -EINVAL; 421 goto out; 422 } 423 424 ncontext = sidtab_search(&sidtab, newsid); 425 if (!ncontext) { 426 printk(KERN_ERR "security_validate_transition: " 427 " unrecognized SID %d\n", newsid); 428 rc = -EINVAL; 429 goto out; 430 } 431 432 tcontext = sidtab_search(&sidtab, tasksid); 433 if (!tcontext) { 434 printk(KERN_ERR "security_validate_transition: " 435 " unrecognized SID %d\n", tasksid); 436 rc = -EINVAL; 437 goto out; 438 } 439 440 constraint = tclass_datum->validatetrans; 441 while (constraint) { 442 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 443 constraint->expr)) { 444 rc = security_validtrans_handle_fail(ocontext, ncontext, 445 tcontext, tclass); 446 goto out; 447 } 448 constraint = constraint->next; 449 } 450 451 out: 452 POLICY_RDUNLOCK; 453 return rc; 454 } 455 456 /** 457 * security_compute_av - Compute access vector decisions. 458 * @ssid: source security identifier 459 * @tsid: target security identifier 460 * @tclass: target security class 461 * @requested: requested permissions 462 * @avd: access vector decisions 463 * 464 * Compute a set of access vector decisions based on the 465 * SID pair (@ssid, @tsid) for the permissions in @tclass. 466 * Return -%EINVAL if any of the parameters are invalid or %0 467 * if the access vector decisions were computed successfully. 468 */ 469 int security_compute_av(u32 ssid, 470 u32 tsid, 471 u16 tclass, 472 u32 requested, 473 struct av_decision *avd) 474 { 475 struct context *scontext = NULL, *tcontext = NULL; 476 int rc = 0; 477 478 if (!ss_initialized) { 479 avd->allowed = 0xffffffff; 480 avd->decided = 0xffffffff; 481 avd->auditallow = 0; 482 avd->auditdeny = 0xffffffff; 483 avd->seqno = latest_granting; 484 return 0; 485 } 486 487 POLICY_RDLOCK; 488 489 scontext = sidtab_search(&sidtab, ssid); 490 if (!scontext) { 491 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", 492 ssid); 493 rc = -EINVAL; 494 goto out; 495 } 496 tcontext = sidtab_search(&sidtab, tsid); 497 if (!tcontext) { 498 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", 499 tsid); 500 rc = -EINVAL; 501 goto out; 502 } 503 504 rc = context_struct_compute_av(scontext, tcontext, tclass, 505 requested, avd); 506 out: 507 POLICY_RDUNLOCK; 508 return rc; 509 } 510 511 /* 512 * Write the security context string representation of 513 * the context structure `context' into a dynamically 514 * allocated string of the correct size. Set `*scontext' 515 * to point to this string and set `*scontext_len' to 516 * the length of the string. 517 */ 518 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 519 { 520 char *scontextp; 521 522 *scontext = NULL; 523 *scontext_len = 0; 524 525 /* Compute the size of the context. */ 526 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1; 527 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1; 528 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1; 529 *scontext_len += mls_compute_context_len(context); 530 531 /* Allocate space for the context; caller must free this space. */ 532 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 533 if (!scontextp) { 534 return -ENOMEM; 535 } 536 *scontext = scontextp; 537 538 /* 539 * Copy the user name, role name and type name into the context. 540 */ 541 sprintf(scontextp, "%s:%s:%s", 542 policydb.p_user_val_to_name[context->user - 1], 543 policydb.p_role_val_to_name[context->role - 1], 544 policydb.p_type_val_to_name[context->type - 1]); 545 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) + 546 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) + 547 1 + strlen(policydb.p_type_val_to_name[context->type - 1]); 548 549 mls_sid_to_context(context, &scontextp); 550 551 *scontextp = 0; 552 553 return 0; 554 } 555 556 #include "initial_sid_to_string.h" 557 558 /** 559 * security_sid_to_context - Obtain a context for a given SID. 560 * @sid: security identifier, SID 561 * @scontext: security context 562 * @scontext_len: length in bytes 563 * 564 * Write the string representation of the context associated with @sid 565 * into a dynamically allocated string of the correct size. Set @scontext 566 * to point to this string and set @scontext_len to the length of the string. 567 */ 568 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 569 { 570 struct context *context; 571 int rc = 0; 572 573 if (!ss_initialized) { 574 if (sid <= SECINITSID_NUM) { 575 char *scontextp; 576 577 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 578 scontextp = kmalloc(*scontext_len,GFP_ATOMIC); 579 strcpy(scontextp, initial_sid_to_string[sid]); 580 *scontext = scontextp; 581 goto out; 582 } 583 printk(KERN_ERR "security_sid_to_context: called before initial " 584 "load_policy on unknown SID %d\n", sid); 585 rc = -EINVAL; 586 goto out; 587 } 588 POLICY_RDLOCK; 589 context = sidtab_search(&sidtab, sid); 590 if (!context) { 591 printk(KERN_ERR "security_sid_to_context: unrecognized SID " 592 "%d\n", sid); 593 rc = -EINVAL; 594 goto out_unlock; 595 } 596 rc = context_struct_to_string(context, scontext, scontext_len); 597 out_unlock: 598 POLICY_RDUNLOCK; 599 out: 600 return rc; 601 602 } 603 604 /** 605 * security_context_to_sid - Obtain a SID for a given security context. 606 * @scontext: security context 607 * @scontext_len: length in bytes 608 * @sid: security identifier, SID 609 * 610 * Obtains a SID associated with the security context that 611 * has the string representation specified by @scontext. 612 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 613 * memory is available, or 0 on success. 614 */ 615 int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid) 616 { 617 char *scontext2; 618 struct context context; 619 struct role_datum *role; 620 struct type_datum *typdatum; 621 struct user_datum *usrdatum; 622 char *scontextp, *p, oldc; 623 int rc = 0; 624 625 if (!ss_initialized) { 626 int i; 627 628 for (i = 1; i < SECINITSID_NUM; i++) { 629 if (!strcmp(initial_sid_to_string[i], scontext)) { 630 *sid = i; 631 goto out; 632 } 633 } 634 *sid = SECINITSID_KERNEL; 635 goto out; 636 } 637 *sid = SECSID_NULL; 638 639 /* Copy the string so that we can modify the copy as we parse it. 640 The string should already by null terminated, but we append a 641 null suffix to the copy to avoid problems with the existing 642 attr package, which doesn't view the null terminator as part 643 of the attribute value. */ 644 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL); 645 if (!scontext2) { 646 rc = -ENOMEM; 647 goto out; 648 } 649 memcpy(scontext2, scontext, scontext_len); 650 scontext2[scontext_len] = 0; 651 652 context_init(&context); 653 *sid = SECSID_NULL; 654 655 POLICY_RDLOCK; 656 657 /* Parse the security context. */ 658 659 rc = -EINVAL; 660 scontextp = (char *) scontext2; 661 662 /* Extract the user. */ 663 p = scontextp; 664 while (*p && *p != ':') 665 p++; 666 667 if (*p == 0) 668 goto out_unlock; 669 670 *p++ = 0; 671 672 usrdatum = hashtab_search(policydb.p_users.table, scontextp); 673 if (!usrdatum) 674 goto out_unlock; 675 676 context.user = usrdatum->value; 677 678 /* Extract role. */ 679 scontextp = p; 680 while (*p && *p != ':') 681 p++; 682 683 if (*p == 0) 684 goto out_unlock; 685 686 *p++ = 0; 687 688 role = hashtab_search(policydb.p_roles.table, scontextp); 689 if (!role) 690 goto out_unlock; 691 context.role = role->value; 692 693 /* Extract type. */ 694 scontextp = p; 695 while (*p && *p != ':') 696 p++; 697 oldc = *p; 698 *p++ = 0; 699 700 typdatum = hashtab_search(policydb.p_types.table, scontextp); 701 if (!typdatum) 702 goto out_unlock; 703 704 context.type = typdatum->value; 705 706 rc = mls_context_to_sid(oldc, &p, &context); 707 if (rc) 708 goto out_unlock; 709 710 if ((p - scontext2) < scontext_len) { 711 rc = -EINVAL; 712 goto out_unlock; 713 } 714 715 /* Check the validity of the new context. */ 716 if (!policydb_context_isvalid(&policydb, &context)) { 717 rc = -EINVAL; 718 goto out_unlock; 719 } 720 /* Obtain the new sid. */ 721 rc = sidtab_context_to_sid(&sidtab, &context, sid); 722 out_unlock: 723 POLICY_RDUNLOCK; 724 context_destroy(&context); 725 kfree(scontext2); 726 out: 727 return rc; 728 } 729 730 static int compute_sid_handle_invalid_context( 731 struct context *scontext, 732 struct context *tcontext, 733 u16 tclass, 734 struct context *newcontext) 735 { 736 char *s = NULL, *t = NULL, *n = NULL; 737 u32 slen, tlen, nlen; 738 739 if (context_struct_to_string(scontext, &s, &slen) < 0) 740 goto out; 741 if (context_struct_to_string(tcontext, &t, &tlen) < 0) 742 goto out; 743 if (context_struct_to_string(newcontext, &n, &nlen) < 0) 744 goto out; 745 audit_log(current->audit_context, AUDIT_SELINUX_ERR, 746 "security_compute_sid: invalid context %s" 747 " for scontext=%s" 748 " tcontext=%s" 749 " tclass=%s", 750 n, s, t, policydb.p_class_val_to_name[tclass-1]); 751 out: 752 kfree(s); 753 kfree(t); 754 kfree(n); 755 if (!selinux_enforcing) 756 return 0; 757 return -EACCES; 758 } 759 760 static int security_compute_sid(u32 ssid, 761 u32 tsid, 762 u16 tclass, 763 u32 specified, 764 u32 *out_sid) 765 { 766 struct context *scontext = NULL, *tcontext = NULL, newcontext; 767 struct role_trans *roletr = NULL; 768 struct avtab_key avkey; 769 struct avtab_datum *avdatum; 770 struct avtab_node *node; 771 unsigned int type_change = 0; 772 int rc = 0; 773 774 if (!ss_initialized) { 775 switch (tclass) { 776 case SECCLASS_PROCESS: 777 *out_sid = ssid; 778 break; 779 default: 780 *out_sid = tsid; 781 break; 782 } 783 goto out; 784 } 785 786 POLICY_RDLOCK; 787 788 scontext = sidtab_search(&sidtab, ssid); 789 if (!scontext) { 790 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", 791 ssid); 792 rc = -EINVAL; 793 goto out_unlock; 794 } 795 tcontext = sidtab_search(&sidtab, tsid); 796 if (!tcontext) { 797 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", 798 tsid); 799 rc = -EINVAL; 800 goto out_unlock; 801 } 802 803 context_init(&newcontext); 804 805 /* Set the user identity. */ 806 switch (specified) { 807 case AVTAB_TRANSITION: 808 case AVTAB_CHANGE: 809 /* Use the process user identity. */ 810 newcontext.user = scontext->user; 811 break; 812 case AVTAB_MEMBER: 813 /* Use the related object owner. */ 814 newcontext.user = tcontext->user; 815 break; 816 } 817 818 /* Set the role and type to default values. */ 819 switch (tclass) { 820 case SECCLASS_PROCESS: 821 /* Use the current role and type of process. */ 822 newcontext.role = scontext->role; 823 newcontext.type = scontext->type; 824 break; 825 default: 826 /* Use the well-defined object role. */ 827 newcontext.role = OBJECT_R_VAL; 828 /* Use the type of the related object. */ 829 newcontext.type = tcontext->type; 830 } 831 832 /* Look for a type transition/member/change rule. */ 833 avkey.source_type = scontext->type; 834 avkey.target_type = tcontext->type; 835 avkey.target_class = tclass; 836 avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_TYPE); 837 838 /* If no permanent rule, also check for enabled conditional rules */ 839 if(!avdatum) { 840 node = avtab_search_node(&policydb.te_cond_avtab, &avkey, specified); 841 for (; node != NULL; node = avtab_search_node_next(node, specified)) { 842 if (node->datum.specified & AVTAB_ENABLED) { 843 avdatum = &node->datum; 844 break; 845 } 846 } 847 } 848 849 type_change = (avdatum && (avdatum->specified & specified)); 850 if (type_change) { 851 /* Use the type from the type transition/member/change rule. */ 852 switch (specified) { 853 case AVTAB_TRANSITION: 854 newcontext.type = avtab_transition(avdatum); 855 break; 856 case AVTAB_MEMBER: 857 newcontext.type = avtab_member(avdatum); 858 break; 859 case AVTAB_CHANGE: 860 newcontext.type = avtab_change(avdatum); 861 break; 862 } 863 } 864 865 /* Check for class-specific changes. */ 866 switch (tclass) { 867 case SECCLASS_PROCESS: 868 if (specified & AVTAB_TRANSITION) { 869 /* Look for a role transition rule. */ 870 for (roletr = policydb.role_tr; roletr; 871 roletr = roletr->next) { 872 if (roletr->role == scontext->role && 873 roletr->type == tcontext->type) { 874 /* Use the role transition rule. */ 875 newcontext.role = roletr->new_role; 876 break; 877 } 878 } 879 } 880 break; 881 default: 882 break; 883 } 884 885 /* Set the MLS attributes. 886 This is done last because it may allocate memory. */ 887 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext); 888 if (rc) 889 goto out_unlock; 890 891 /* Check the validity of the context. */ 892 if (!policydb_context_isvalid(&policydb, &newcontext)) { 893 rc = compute_sid_handle_invalid_context(scontext, 894 tcontext, 895 tclass, 896 &newcontext); 897 if (rc) 898 goto out_unlock; 899 } 900 /* Obtain the sid for the context. */ 901 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 902 out_unlock: 903 POLICY_RDUNLOCK; 904 context_destroy(&newcontext); 905 out: 906 return rc; 907 } 908 909 /** 910 * security_transition_sid - Compute the SID for a new subject/object. 911 * @ssid: source security identifier 912 * @tsid: target security identifier 913 * @tclass: target security class 914 * @out_sid: security identifier for new subject/object 915 * 916 * Compute a SID to use for labeling a new subject or object in the 917 * class @tclass based on a SID pair (@ssid, @tsid). 918 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 919 * if insufficient memory is available, or %0 if the new SID was 920 * computed successfully. 921 */ 922 int security_transition_sid(u32 ssid, 923 u32 tsid, 924 u16 tclass, 925 u32 *out_sid) 926 { 927 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid); 928 } 929 930 /** 931 * security_member_sid - Compute the SID for member selection. 932 * @ssid: source security identifier 933 * @tsid: target security identifier 934 * @tclass: target security class 935 * @out_sid: security identifier for selected member 936 * 937 * Compute a SID to use when selecting a member of a polyinstantiated 938 * object of class @tclass based on a SID pair (@ssid, @tsid). 939 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 940 * if insufficient memory is available, or %0 if the SID was 941 * computed successfully. 942 */ 943 int security_member_sid(u32 ssid, 944 u32 tsid, 945 u16 tclass, 946 u32 *out_sid) 947 { 948 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid); 949 } 950 951 /** 952 * security_change_sid - Compute the SID for object relabeling. 953 * @ssid: source security identifier 954 * @tsid: target security identifier 955 * @tclass: target security class 956 * @out_sid: security identifier for selected member 957 * 958 * Compute a SID to use for relabeling an object of class @tclass 959 * based on a SID pair (@ssid, @tsid). 960 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 961 * if insufficient memory is available, or %0 if the SID was 962 * computed successfully. 963 */ 964 int security_change_sid(u32 ssid, 965 u32 tsid, 966 u16 tclass, 967 u32 *out_sid) 968 { 969 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid); 970 } 971 972 /* 973 * Verify that each permission that is defined under the 974 * existing policy is still defined with the same value 975 * in the new policy. 976 */ 977 static int validate_perm(void *key, void *datum, void *p) 978 { 979 struct hashtab *h; 980 struct perm_datum *perdatum, *perdatum2; 981 int rc = 0; 982 983 984 h = p; 985 perdatum = datum; 986 987 perdatum2 = hashtab_search(h, key); 988 if (!perdatum2) { 989 printk(KERN_ERR "security: permission %s disappeared", 990 (char *)key); 991 rc = -ENOENT; 992 goto out; 993 } 994 if (perdatum->value != perdatum2->value) { 995 printk(KERN_ERR "security: the value of permission %s changed", 996 (char *)key); 997 rc = -EINVAL; 998 } 999 out: 1000 return rc; 1001 } 1002 1003 /* 1004 * Verify that each class that is defined under the 1005 * existing policy is still defined with the same 1006 * attributes in the new policy. 1007 */ 1008 static int validate_class(void *key, void *datum, void *p) 1009 { 1010 struct policydb *newp; 1011 struct class_datum *cladatum, *cladatum2; 1012 int rc; 1013 1014 newp = p; 1015 cladatum = datum; 1016 1017 cladatum2 = hashtab_search(newp->p_classes.table, key); 1018 if (!cladatum2) { 1019 printk(KERN_ERR "security: class %s disappeared\n", 1020 (char *)key); 1021 rc = -ENOENT; 1022 goto out; 1023 } 1024 if (cladatum->value != cladatum2->value) { 1025 printk(KERN_ERR "security: the value of class %s changed\n", 1026 (char *)key); 1027 rc = -EINVAL; 1028 goto out; 1029 } 1030 if ((cladatum->comdatum && !cladatum2->comdatum) || 1031 (!cladatum->comdatum && cladatum2->comdatum)) { 1032 printk(KERN_ERR "security: the inherits clause for the access " 1033 "vector definition for class %s changed\n", (char *)key); 1034 rc = -EINVAL; 1035 goto out; 1036 } 1037 if (cladatum->comdatum) { 1038 rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm, 1039 cladatum2->comdatum->permissions.table); 1040 if (rc) { 1041 printk(" in the access vector definition for class " 1042 "%s\n", (char *)key); 1043 goto out; 1044 } 1045 } 1046 rc = hashtab_map(cladatum->permissions.table, validate_perm, 1047 cladatum2->permissions.table); 1048 if (rc) 1049 printk(" in access vector definition for class %s\n", 1050 (char *)key); 1051 out: 1052 return rc; 1053 } 1054 1055 /* Clone the SID into the new SID table. */ 1056 static int clone_sid(u32 sid, 1057 struct context *context, 1058 void *arg) 1059 { 1060 struct sidtab *s = arg; 1061 1062 return sidtab_insert(s, sid, context); 1063 } 1064 1065 static inline int convert_context_handle_invalid_context(struct context *context) 1066 { 1067 int rc = 0; 1068 1069 if (selinux_enforcing) { 1070 rc = -EINVAL; 1071 } else { 1072 char *s; 1073 u32 len; 1074 1075 context_struct_to_string(context, &s, &len); 1076 printk(KERN_ERR "security: context %s is invalid\n", s); 1077 kfree(s); 1078 } 1079 return rc; 1080 } 1081 1082 struct convert_context_args { 1083 struct policydb *oldp; 1084 struct policydb *newp; 1085 }; 1086 1087 /* 1088 * Convert the values in the security context 1089 * structure `c' from the values specified 1090 * in the policy `p->oldp' to the values specified 1091 * in the policy `p->newp'. Verify that the 1092 * context is valid under the new policy. 1093 */ 1094 static int convert_context(u32 key, 1095 struct context *c, 1096 void *p) 1097 { 1098 struct convert_context_args *args; 1099 struct context oldc; 1100 struct role_datum *role; 1101 struct type_datum *typdatum; 1102 struct user_datum *usrdatum; 1103 char *s; 1104 u32 len; 1105 int rc; 1106 1107 args = p; 1108 1109 rc = context_cpy(&oldc, c); 1110 if (rc) 1111 goto out; 1112 1113 rc = -EINVAL; 1114 1115 /* Convert the user. */ 1116 usrdatum = hashtab_search(args->newp->p_users.table, 1117 args->oldp->p_user_val_to_name[c->user - 1]); 1118 if (!usrdatum) { 1119 goto bad; 1120 } 1121 c->user = usrdatum->value; 1122 1123 /* Convert the role. */ 1124 role = hashtab_search(args->newp->p_roles.table, 1125 args->oldp->p_role_val_to_name[c->role - 1]); 1126 if (!role) { 1127 goto bad; 1128 } 1129 c->role = role->value; 1130 1131 /* Convert the type. */ 1132 typdatum = hashtab_search(args->newp->p_types.table, 1133 args->oldp->p_type_val_to_name[c->type - 1]); 1134 if (!typdatum) { 1135 goto bad; 1136 } 1137 c->type = typdatum->value; 1138 1139 rc = mls_convert_context(args->oldp, args->newp, c); 1140 if (rc) 1141 goto bad; 1142 1143 /* Check the validity of the new context. */ 1144 if (!policydb_context_isvalid(args->newp, c)) { 1145 rc = convert_context_handle_invalid_context(&oldc); 1146 if (rc) 1147 goto bad; 1148 } 1149 1150 context_destroy(&oldc); 1151 out: 1152 return rc; 1153 bad: 1154 context_struct_to_string(&oldc, &s, &len); 1155 context_destroy(&oldc); 1156 printk(KERN_ERR "security: invalidating context %s\n", s); 1157 kfree(s); 1158 goto out; 1159 } 1160 1161 extern void selinux_complete_init(void); 1162 1163 /** 1164 * security_load_policy - Load a security policy configuration. 1165 * @data: binary policy data 1166 * @len: length of data in bytes 1167 * 1168 * Load a new set of security policy configuration data, 1169 * validate it and convert the SID table as necessary. 1170 * This function will flush the access vector cache after 1171 * loading the new policy. 1172 */ 1173 int security_load_policy(void *data, size_t len) 1174 { 1175 struct policydb oldpolicydb, newpolicydb; 1176 struct sidtab oldsidtab, newsidtab; 1177 struct convert_context_args args; 1178 u32 seqno; 1179 int rc = 0; 1180 struct policy_file file = { data, len }, *fp = &file; 1181 1182 LOAD_LOCK; 1183 1184 if (!ss_initialized) { 1185 avtab_cache_init(); 1186 if (policydb_read(&policydb, fp)) { 1187 LOAD_UNLOCK; 1188 avtab_cache_destroy(); 1189 return -EINVAL; 1190 } 1191 if (policydb_load_isids(&policydb, &sidtab)) { 1192 LOAD_UNLOCK; 1193 policydb_destroy(&policydb); 1194 avtab_cache_destroy(); 1195 return -EINVAL; 1196 } 1197 policydb_loaded_version = policydb.policyvers; 1198 ss_initialized = 1; 1199 seqno = ++latest_granting; 1200 LOAD_UNLOCK; 1201 selinux_complete_init(); 1202 avc_ss_reset(seqno); 1203 selnl_notify_policyload(seqno); 1204 return 0; 1205 } 1206 1207 #if 0 1208 sidtab_hash_eval(&sidtab, "sids"); 1209 #endif 1210 1211 if (policydb_read(&newpolicydb, fp)) { 1212 LOAD_UNLOCK; 1213 return -EINVAL; 1214 } 1215 1216 sidtab_init(&newsidtab); 1217 1218 /* Verify that the existing classes did not change. */ 1219 if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) { 1220 printk(KERN_ERR "security: the definition of an existing " 1221 "class changed\n"); 1222 rc = -EINVAL; 1223 goto err; 1224 } 1225 1226 /* Clone the SID table. */ 1227 sidtab_shutdown(&sidtab); 1228 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) { 1229 rc = -ENOMEM; 1230 goto err; 1231 } 1232 1233 /* Convert the internal representations of contexts 1234 in the new SID table and remove invalid SIDs. */ 1235 args.oldp = &policydb; 1236 args.newp = &newpolicydb; 1237 sidtab_map_remove_on_error(&newsidtab, convert_context, &args); 1238 1239 /* Save the old policydb and SID table to free later. */ 1240 memcpy(&oldpolicydb, &policydb, sizeof policydb); 1241 sidtab_set(&oldsidtab, &sidtab); 1242 1243 /* Install the new policydb and SID table. */ 1244 POLICY_WRLOCK; 1245 memcpy(&policydb, &newpolicydb, sizeof policydb); 1246 sidtab_set(&sidtab, &newsidtab); 1247 seqno = ++latest_granting; 1248 policydb_loaded_version = policydb.policyvers; 1249 POLICY_WRUNLOCK; 1250 LOAD_UNLOCK; 1251 1252 /* Free the old policydb and SID table. */ 1253 policydb_destroy(&oldpolicydb); 1254 sidtab_destroy(&oldsidtab); 1255 1256 avc_ss_reset(seqno); 1257 selnl_notify_policyload(seqno); 1258 1259 return 0; 1260 1261 err: 1262 LOAD_UNLOCK; 1263 sidtab_destroy(&newsidtab); 1264 policydb_destroy(&newpolicydb); 1265 return rc; 1266 1267 } 1268 1269 /** 1270 * security_port_sid - Obtain the SID for a port. 1271 * @domain: communication domain aka address family 1272 * @type: socket type 1273 * @protocol: protocol number 1274 * @port: port number 1275 * @out_sid: security identifier 1276 */ 1277 int security_port_sid(u16 domain, 1278 u16 type, 1279 u8 protocol, 1280 u16 port, 1281 u32 *out_sid) 1282 { 1283 struct ocontext *c; 1284 int rc = 0; 1285 1286 POLICY_RDLOCK; 1287 1288 c = policydb.ocontexts[OCON_PORT]; 1289 while (c) { 1290 if (c->u.port.protocol == protocol && 1291 c->u.port.low_port <= port && 1292 c->u.port.high_port >= port) 1293 break; 1294 c = c->next; 1295 } 1296 1297 if (c) { 1298 if (!c->sid[0]) { 1299 rc = sidtab_context_to_sid(&sidtab, 1300 &c->context[0], 1301 &c->sid[0]); 1302 if (rc) 1303 goto out; 1304 } 1305 *out_sid = c->sid[0]; 1306 } else { 1307 *out_sid = SECINITSID_PORT; 1308 } 1309 1310 out: 1311 POLICY_RDUNLOCK; 1312 return rc; 1313 } 1314 1315 /** 1316 * security_netif_sid - Obtain the SID for a network interface. 1317 * @name: interface name 1318 * @if_sid: interface SID 1319 * @msg_sid: default SID for received packets 1320 */ 1321 int security_netif_sid(char *name, 1322 u32 *if_sid, 1323 u32 *msg_sid) 1324 { 1325 int rc = 0; 1326 struct ocontext *c; 1327 1328 POLICY_RDLOCK; 1329 1330 c = policydb.ocontexts[OCON_NETIF]; 1331 while (c) { 1332 if (strcmp(name, c->u.name) == 0) 1333 break; 1334 c = c->next; 1335 } 1336 1337 if (c) { 1338 if (!c->sid[0] || !c->sid[1]) { 1339 rc = sidtab_context_to_sid(&sidtab, 1340 &c->context[0], 1341 &c->sid[0]); 1342 if (rc) 1343 goto out; 1344 rc = sidtab_context_to_sid(&sidtab, 1345 &c->context[1], 1346 &c->sid[1]); 1347 if (rc) 1348 goto out; 1349 } 1350 *if_sid = c->sid[0]; 1351 *msg_sid = c->sid[1]; 1352 } else { 1353 *if_sid = SECINITSID_NETIF; 1354 *msg_sid = SECINITSID_NETMSG; 1355 } 1356 1357 out: 1358 POLICY_RDUNLOCK; 1359 return rc; 1360 } 1361 1362 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 1363 { 1364 int i, fail = 0; 1365 1366 for(i = 0; i < 4; i++) 1367 if(addr[i] != (input[i] & mask[i])) { 1368 fail = 1; 1369 break; 1370 } 1371 1372 return !fail; 1373 } 1374 1375 /** 1376 * security_node_sid - Obtain the SID for a node (host). 1377 * @domain: communication domain aka address family 1378 * @addrp: address 1379 * @addrlen: address length in bytes 1380 * @out_sid: security identifier 1381 */ 1382 int security_node_sid(u16 domain, 1383 void *addrp, 1384 u32 addrlen, 1385 u32 *out_sid) 1386 { 1387 int rc = 0; 1388 struct ocontext *c; 1389 1390 POLICY_RDLOCK; 1391 1392 switch (domain) { 1393 case AF_INET: { 1394 u32 addr; 1395 1396 if (addrlen != sizeof(u32)) { 1397 rc = -EINVAL; 1398 goto out; 1399 } 1400 1401 addr = *((u32 *)addrp); 1402 1403 c = policydb.ocontexts[OCON_NODE]; 1404 while (c) { 1405 if (c->u.node.addr == (addr & c->u.node.mask)) 1406 break; 1407 c = c->next; 1408 } 1409 break; 1410 } 1411 1412 case AF_INET6: 1413 if (addrlen != sizeof(u64) * 2) { 1414 rc = -EINVAL; 1415 goto out; 1416 } 1417 c = policydb.ocontexts[OCON_NODE6]; 1418 while (c) { 1419 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 1420 c->u.node6.mask)) 1421 break; 1422 c = c->next; 1423 } 1424 break; 1425 1426 default: 1427 *out_sid = SECINITSID_NODE; 1428 goto out; 1429 } 1430 1431 if (c) { 1432 if (!c->sid[0]) { 1433 rc = sidtab_context_to_sid(&sidtab, 1434 &c->context[0], 1435 &c->sid[0]); 1436 if (rc) 1437 goto out; 1438 } 1439 *out_sid = c->sid[0]; 1440 } else { 1441 *out_sid = SECINITSID_NODE; 1442 } 1443 1444 out: 1445 POLICY_RDUNLOCK; 1446 return rc; 1447 } 1448 1449 #define SIDS_NEL 25 1450 1451 /** 1452 * security_get_user_sids - Obtain reachable SIDs for a user. 1453 * @fromsid: starting SID 1454 * @username: username 1455 * @sids: array of reachable SIDs for user 1456 * @nel: number of elements in @sids 1457 * 1458 * Generate the set of SIDs for legal security contexts 1459 * for a given user that can be reached by @fromsid. 1460 * Set *@sids to point to a dynamically allocated 1461 * array containing the set of SIDs. Set *@nel to the 1462 * number of elements in the array. 1463 */ 1464 1465 int security_get_user_sids(u32 fromsid, 1466 char *username, 1467 u32 **sids, 1468 u32 *nel) 1469 { 1470 struct context *fromcon, usercon; 1471 u32 *mysids, *mysids2, sid; 1472 u32 mynel = 0, maxnel = SIDS_NEL; 1473 struct user_datum *user; 1474 struct role_datum *role; 1475 struct av_decision avd; 1476 int rc = 0, i, j; 1477 1478 if (!ss_initialized) { 1479 *sids = NULL; 1480 *nel = 0; 1481 goto out; 1482 } 1483 1484 POLICY_RDLOCK; 1485 1486 fromcon = sidtab_search(&sidtab, fromsid); 1487 if (!fromcon) { 1488 rc = -EINVAL; 1489 goto out_unlock; 1490 } 1491 1492 user = hashtab_search(policydb.p_users.table, username); 1493 if (!user) { 1494 rc = -EINVAL; 1495 goto out_unlock; 1496 } 1497 usercon.user = user->value; 1498 1499 mysids = kmalloc(maxnel*sizeof(*mysids), GFP_ATOMIC); 1500 if (!mysids) { 1501 rc = -ENOMEM; 1502 goto out_unlock; 1503 } 1504 memset(mysids, 0, maxnel*sizeof(*mysids)); 1505 1506 for (i = ebitmap_startbit(&user->roles); i < ebitmap_length(&user->roles); i++) { 1507 if (!ebitmap_get_bit(&user->roles, i)) 1508 continue; 1509 role = policydb.role_val_to_struct[i]; 1510 usercon.role = i+1; 1511 for (j = ebitmap_startbit(&role->types); j < ebitmap_length(&role->types); j++) { 1512 if (!ebitmap_get_bit(&role->types, j)) 1513 continue; 1514 usercon.type = j+1; 1515 1516 if (mls_setup_user_range(fromcon, user, &usercon)) 1517 continue; 1518 1519 rc = context_struct_compute_av(fromcon, &usercon, 1520 SECCLASS_PROCESS, 1521 PROCESS__TRANSITION, 1522 &avd); 1523 if (rc || !(avd.allowed & PROCESS__TRANSITION)) 1524 continue; 1525 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 1526 if (rc) { 1527 kfree(mysids); 1528 goto out_unlock; 1529 } 1530 if (mynel < maxnel) { 1531 mysids[mynel++] = sid; 1532 } else { 1533 maxnel += SIDS_NEL; 1534 mysids2 = kmalloc(maxnel*sizeof(*mysids2), GFP_ATOMIC); 1535 if (!mysids2) { 1536 rc = -ENOMEM; 1537 kfree(mysids); 1538 goto out_unlock; 1539 } 1540 memset(mysids2, 0, maxnel*sizeof(*mysids2)); 1541 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 1542 kfree(mysids); 1543 mysids = mysids2; 1544 mysids[mynel++] = sid; 1545 } 1546 } 1547 } 1548 1549 *sids = mysids; 1550 *nel = mynel; 1551 1552 out_unlock: 1553 POLICY_RDUNLOCK; 1554 out: 1555 return rc; 1556 } 1557 1558 /** 1559 * security_genfs_sid - Obtain a SID for a file in a filesystem 1560 * @fstype: filesystem type 1561 * @path: path from root of mount 1562 * @sclass: file security class 1563 * @sid: SID for path 1564 * 1565 * Obtain a SID to use for a file in a filesystem that 1566 * cannot support xattr or use a fixed labeling behavior like 1567 * transition SIDs or task SIDs. 1568 */ 1569 int security_genfs_sid(const char *fstype, 1570 char *path, 1571 u16 sclass, 1572 u32 *sid) 1573 { 1574 int len; 1575 struct genfs *genfs; 1576 struct ocontext *c; 1577 int rc = 0, cmp = 0; 1578 1579 POLICY_RDLOCK; 1580 1581 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 1582 cmp = strcmp(fstype, genfs->fstype); 1583 if (cmp <= 0) 1584 break; 1585 } 1586 1587 if (!genfs || cmp) { 1588 *sid = SECINITSID_UNLABELED; 1589 rc = -ENOENT; 1590 goto out; 1591 } 1592 1593 for (c = genfs->head; c; c = c->next) { 1594 len = strlen(c->u.name); 1595 if ((!c->v.sclass || sclass == c->v.sclass) && 1596 (strncmp(c->u.name, path, len) == 0)) 1597 break; 1598 } 1599 1600 if (!c) { 1601 *sid = SECINITSID_UNLABELED; 1602 rc = -ENOENT; 1603 goto out; 1604 } 1605 1606 if (!c->sid[0]) { 1607 rc = sidtab_context_to_sid(&sidtab, 1608 &c->context[0], 1609 &c->sid[0]); 1610 if (rc) 1611 goto out; 1612 } 1613 1614 *sid = c->sid[0]; 1615 out: 1616 POLICY_RDUNLOCK; 1617 return rc; 1618 } 1619 1620 /** 1621 * security_fs_use - Determine how to handle labeling for a filesystem. 1622 * @fstype: filesystem type 1623 * @behavior: labeling behavior 1624 * @sid: SID for filesystem (superblock) 1625 */ 1626 int security_fs_use( 1627 const char *fstype, 1628 unsigned int *behavior, 1629 u32 *sid) 1630 { 1631 int rc = 0; 1632 struct ocontext *c; 1633 1634 POLICY_RDLOCK; 1635 1636 c = policydb.ocontexts[OCON_FSUSE]; 1637 while (c) { 1638 if (strcmp(fstype, c->u.name) == 0) 1639 break; 1640 c = c->next; 1641 } 1642 1643 if (c) { 1644 *behavior = c->v.behavior; 1645 if (!c->sid[0]) { 1646 rc = sidtab_context_to_sid(&sidtab, 1647 &c->context[0], 1648 &c->sid[0]); 1649 if (rc) 1650 goto out; 1651 } 1652 *sid = c->sid[0]; 1653 } else { 1654 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid); 1655 if (rc) { 1656 *behavior = SECURITY_FS_USE_NONE; 1657 rc = 0; 1658 } else { 1659 *behavior = SECURITY_FS_USE_GENFS; 1660 } 1661 } 1662 1663 out: 1664 POLICY_RDUNLOCK; 1665 return rc; 1666 } 1667 1668 int security_get_bools(int *len, char ***names, int **values) 1669 { 1670 int i, rc = -ENOMEM; 1671 1672 POLICY_RDLOCK; 1673 *names = NULL; 1674 *values = NULL; 1675 1676 *len = policydb.p_bools.nprim; 1677 if (!*len) { 1678 rc = 0; 1679 goto out; 1680 } 1681 1682 *names = (char**)kmalloc(sizeof(char*) * *len, GFP_ATOMIC); 1683 if (!*names) 1684 goto err; 1685 memset(*names, 0, sizeof(char*) * *len); 1686 1687 *values = (int*)kmalloc(sizeof(int) * *len, GFP_ATOMIC); 1688 if (!*values) 1689 goto err; 1690 1691 for (i = 0; i < *len; i++) { 1692 size_t name_len; 1693 (*values)[i] = policydb.bool_val_to_struct[i]->state; 1694 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1; 1695 (*names)[i] = (char*)kmalloc(sizeof(char) * name_len, GFP_ATOMIC); 1696 if (!(*names)[i]) 1697 goto err; 1698 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len); 1699 (*names)[i][name_len - 1] = 0; 1700 } 1701 rc = 0; 1702 out: 1703 POLICY_RDUNLOCK; 1704 return rc; 1705 err: 1706 if (*names) { 1707 for (i = 0; i < *len; i++) 1708 kfree((*names)[i]); 1709 } 1710 kfree(*values); 1711 goto out; 1712 } 1713 1714 1715 int security_set_bools(int len, int *values) 1716 { 1717 int i, rc = 0; 1718 int lenp, seqno = 0; 1719 struct cond_node *cur; 1720 1721 POLICY_WRLOCK; 1722 1723 lenp = policydb.p_bools.nprim; 1724 if (len != lenp) { 1725 rc = -EFAULT; 1726 goto out; 1727 } 1728 1729 printk(KERN_INFO "security: committed booleans { "); 1730 for (i = 0; i < len; i++) { 1731 if (values[i]) { 1732 policydb.bool_val_to_struct[i]->state = 1; 1733 } else { 1734 policydb.bool_val_to_struct[i]->state = 0; 1735 } 1736 if (i != 0) 1737 printk(", "); 1738 printk("%s:%d", policydb.p_bool_val_to_name[i], 1739 policydb.bool_val_to_struct[i]->state); 1740 } 1741 printk(" }\n"); 1742 1743 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { 1744 rc = evaluate_cond_node(&policydb, cur); 1745 if (rc) 1746 goto out; 1747 } 1748 1749 seqno = ++latest_granting; 1750 1751 out: 1752 POLICY_WRUNLOCK; 1753 if (!rc) { 1754 avc_ss_reset(seqno); 1755 selnl_notify_policyload(seqno); 1756 } 1757 return rc; 1758 } 1759 1760 int security_get_bool_value(int bool) 1761 { 1762 int rc = 0; 1763 int len; 1764 1765 POLICY_RDLOCK; 1766 1767 len = policydb.p_bools.nprim; 1768 if (bool >= len) { 1769 rc = -EFAULT; 1770 goto out; 1771 } 1772 1773 rc = policydb.bool_val_to_struct[bool]->state; 1774 out: 1775 POLICY_RDUNLOCK; 1776 return rc; 1777 } 1778