1 /*- 2 * Copyright (c) 1999-2002, 2006, 2009 Robert N. M. Watson 3 * Copyright (c) 2001 Ilmar S. Habibulin 4 * Copyright (c) 2001-2005 Networks Associates Technology, Inc. 5 * Copyright (c) 2005-2006 SPARTA, Inc. 6 * Copyright (c) 2008-2009 Apple Inc. 7 * All rights reserved. 8 * 9 * This software was developed by Robert Watson and Ilmar Habibulin for the 10 * TrustedBSD Project. 11 * 12 * This software was developed for the FreeBSD Project in part by Network 13 * Associates Laboratories, the Security Research Division of Network 14 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 15 * as part of the DARPA CHATS research program. 16 * 17 * This software was enhanced by SPARTA ISSO under SPAWAR contract 18 * N66001-04-C-6019 ("SEFOS"). 19 * 20 * This software was developed at the University of Cambridge Computer 21 * Laboratory with support from a grant from Google, Inc. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the above copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 */ 44 45 /*- 46 * Framework for extensible kernel access control. This file contains core 47 * kernel infrastructure for the TrustedBSD MAC Framework, including policy 48 * registration, versioning, locking, error composition operator, and system 49 * calls. 50 * 51 * The MAC Framework implements three programming interfaces: 52 * 53 * - The kernel MAC interface, defined in mac_framework.h, and invoked 54 * throughout the kernel to request security decisions, notify of security 55 * related events, etc. 56 * 57 * - The MAC policy module interface, defined in mac_policy.h, which is 58 * implemented by MAC policy modules and invoked by the MAC Framework to 59 * forward kernel security requests and notifications to policy modules. 60 * 61 * - The user MAC API, defined in mac.h, which allows user programs to query 62 * and set label state on objects. 63 * 64 * The majority of the MAC Framework implementation may be found in 65 * src/sys/security/mac. Sample policy modules may be found in 66 * src/sys/security/mac_*. 67 */ 68 69 #include "opt_mac.h" 70 71 #include <sys/cdefs.h> 72 __FBSDID("$FreeBSD$"); 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/condvar.h> 77 #include <sys/kernel.h> 78 #include <sys/lock.h> 79 #include <sys/mac.h> 80 #include <sys/module.h> 81 #include <sys/rmlock.h> 82 #include <sys/sdt.h> 83 #include <sys/sx.h> 84 #include <sys/sysctl.h> 85 #include <sys/vnode.h> 86 87 #include <security/mac/mac_framework.h> 88 #include <security/mac/mac_internal.h> 89 #include <security/mac/mac_policy.h> 90 91 /* 92 * DTrace SDT providers for MAC. 93 */ 94 SDT_PROVIDER_DEFINE(mac); 95 SDT_PROVIDER_DEFINE(mac_framework); 96 97 SDT_PROBE_DEFINE2(mac, , policy, modevent, "int", 98 "struct mac_policy_conf *"); 99 SDT_PROBE_DEFINE1(mac, , policy, register, 100 "struct mac_policy_conf *"); 101 SDT_PROBE_DEFINE1(mac, , policy, unregister, 102 "struct mac_policy_conf *"); 103 104 /* 105 * Root sysctl node for all MAC and MAC policy controls. 106 */ 107 SYSCTL_NODE(_security, OID_AUTO, mac, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 108 "TrustedBSD MAC policy controls"); 109 110 /* 111 * Declare that the kernel provides MAC support, version 3 (FreeBSD 7.x). 112 * This permits modules to refuse to be loaded if the necessary support isn't 113 * present, even if it's pre-boot. 114 */ 115 MODULE_VERSION(kernel_mac_support, MAC_VERSION); 116 117 static unsigned int mac_version = MAC_VERSION; 118 SYSCTL_UINT(_security_mac, OID_AUTO, version, CTLFLAG_RD, &mac_version, 0, 119 ""); 120 121 /* 122 * Flags for inlined checks. Note this would be best hotpatched at runtime. 123 * The following is a band-aid. 124 * 125 * Use FPFLAG for hooks running in commonly executed paths and FPFLAG_RARE 126 * for the rest. 127 */ 128 #define FPFLAG(f) \ 129 bool __read_frequently mac_##f##_fp_flag 130 131 #define FPFLAG_RARE(f) \ 132 bool __read_mostly mac_##f##_fp_flag 133 134 FPFLAG(priv_check); 135 FPFLAG(priv_grant); 136 FPFLAG(vnode_check_lookup); 137 FPFLAG(vnode_check_open); 138 FPFLAG(vnode_check_stat); 139 FPFLAG(vnode_check_read); 140 FPFLAG(vnode_check_write); 141 FPFLAG(vnode_check_mmap); 142 FPFLAG_RARE(vnode_check_poll); 143 FPFLAG_RARE(vnode_check_rename_from); 144 FPFLAG_RARE(vnode_check_access); 145 FPFLAG_RARE(vnode_check_readlink); 146 FPFLAG_RARE(pipe_check_stat); 147 FPFLAG_RARE(pipe_check_poll); 148 FPFLAG_RARE(ifnet_create_mbuf); 149 FPFLAG_RARE(ifnet_check_transmit); 150 151 #undef FPFLAG 152 #undef FPFLAG_RARE 153 154 /* 155 * Labels consist of a indexed set of "slots", which are allocated policies 156 * as required. The MAC Framework maintains a bitmask of slots allocated so 157 * far to prevent reuse. Slots cannot be reused, as the MAC Framework 158 * guarantees that newly allocated slots in labels will be NULL unless 159 * otherwise initialized, and because we do not have a mechanism to garbage 160 * collect slots on policy unload. As labeled policies tend to be statically 161 * loaded during boot, and not frequently unloaded and reloaded, this is not 162 * generally an issue. 163 */ 164 #if MAC_MAX_SLOTS > 32 165 #error "MAC_MAX_SLOTS too large" 166 #endif 167 168 static unsigned int mac_max_slots = MAC_MAX_SLOTS; 169 static unsigned int mac_slot_offsets_free = (1 << MAC_MAX_SLOTS) - 1; 170 SYSCTL_UINT(_security_mac, OID_AUTO, max_slots, CTLFLAG_RD, &mac_max_slots, 171 0, ""); 172 173 /* 174 * Has the kernel started generating labeled objects yet? All read/write 175 * access to this variable is serialized during the boot process. Following 176 * the end of serialization, we don't update this flag; no locking. 177 */ 178 static int mac_late = 0; 179 180 /* 181 * Each policy declares a mask of object types requiring labels to be 182 * allocated for them. For convenience, we combine and cache the bitwise or 183 * of the per-policy object flags to track whether we will allocate a label 184 * for an object type at run-time. 185 */ 186 uint64_t mac_labeled; 187 SYSCTL_UQUAD(_security_mac, OID_AUTO, labeled, CTLFLAG_RD, &mac_labeled, 0, 188 "Mask of object types being labeled"); 189 190 MALLOC_DEFINE(M_MACTEMP, "mactemp", "MAC temporary label storage"); 191 192 /* 193 * MAC policy modules are placed in one of two lists: mac_static_policy_list, 194 * for policies that are loaded early and cannot be unloaded, and 195 * mac_policy_list, which holds policies either loaded later in the boot 196 * cycle or that may be unloaded. The static policy list does not require 197 * locks to iterate over, but the dynamic list requires synchronization. 198 * Support for dynamic policy loading can be compiled out using the 199 * MAC_STATIC kernel option. 200 * 201 * The dynamic policy list is protected by two locks: modifying the list 202 * requires both locks to be held exclusively. One of the locks, 203 * mac_policy_rm, is acquired over policy entry points that will never sleep; 204 * the other, mac_policy_rms, is acquired over policy entry points that may 205 * sleep. The former category will be used when kernel locks may be held 206 * over calls to the MAC Framework, during network processing in ithreads, 207 * etc. The latter will tend to involve potentially blocking memory 208 * allocations, extended attribute I/O, etc. 209 */ 210 #ifndef MAC_STATIC 211 static struct rmlock mac_policy_rm; /* Non-sleeping entry points. */ 212 static struct rmslock mac_policy_rms; /* Sleeping entry points. */ 213 #endif 214 215 struct mac_policy_list_head mac_policy_list; 216 struct mac_policy_list_head mac_static_policy_list; 217 u_int mac_policy_count; /* Registered policy count. */ 218 219 static void mac_policy_xlock(void); 220 static void mac_policy_xlock_assert(void); 221 static void mac_policy_xunlock(void); 222 223 void 224 mac_policy_slock_nosleep(struct rm_priotracker *tracker) 225 { 226 227 #ifndef MAC_STATIC 228 if (!mac_late) 229 return; 230 231 rm_rlock(&mac_policy_rm, tracker); 232 #endif 233 } 234 235 void 236 mac_policy_slock_sleep(void) 237 { 238 239 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 240 "mac_policy_slock_sleep"); 241 242 #ifndef MAC_STATIC 243 if (!mac_late) 244 return; 245 246 rms_rlock(&mac_policy_rms); 247 #endif 248 } 249 250 void 251 mac_policy_sunlock_nosleep(struct rm_priotracker *tracker) 252 { 253 254 #ifndef MAC_STATIC 255 if (!mac_late) 256 return; 257 258 rm_runlock(&mac_policy_rm, tracker); 259 #endif 260 } 261 262 void 263 mac_policy_sunlock_sleep(void) 264 { 265 266 #ifndef MAC_STATIC 267 if (!mac_late) 268 return; 269 270 rms_runlock(&mac_policy_rms); 271 #endif 272 } 273 274 static void 275 mac_policy_xlock(void) 276 { 277 278 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 279 "mac_policy_xlock()"); 280 281 #ifndef MAC_STATIC 282 if (!mac_late) 283 return; 284 285 rms_wlock(&mac_policy_rms); 286 rm_wlock(&mac_policy_rm); 287 #endif 288 } 289 290 static void 291 mac_policy_xunlock(void) 292 { 293 294 #ifndef MAC_STATIC 295 if (!mac_late) 296 return; 297 298 rm_wunlock(&mac_policy_rm); 299 rms_wunlock(&mac_policy_rms); 300 #endif 301 } 302 303 static void 304 mac_policy_xlock_assert(void) 305 { 306 307 #ifndef MAC_STATIC 308 if (!mac_late) 309 return; 310 311 rm_assert(&mac_policy_rm, RA_WLOCKED); 312 #endif 313 } 314 315 /* 316 * Initialize the MAC subsystem, including appropriate SMP locks. 317 */ 318 static void 319 mac_init(void) 320 { 321 322 LIST_INIT(&mac_static_policy_list); 323 LIST_INIT(&mac_policy_list); 324 mac_labelzone_init(); 325 326 #ifndef MAC_STATIC 327 rm_init_flags(&mac_policy_rm, "mac_policy_rm", RM_NOWITNESS | 328 RM_RECURSE); 329 rms_init(&mac_policy_rms, "mac_policy_rms"); 330 #endif 331 } 332 333 /* 334 * For the purposes of modules that want to know if they were loaded "early", 335 * set the mac_late flag once we've processed modules either linked into the 336 * kernel, or loaded before the kernel startup. 337 */ 338 static void 339 mac_late_init(void) 340 { 341 342 mac_late = 1; 343 } 344 345 /* 346 * Given a policy, derive from its set of non-NULL label init methods what 347 * object types the policy is interested in. 348 */ 349 static uint64_t 350 mac_policy_getlabeled(struct mac_policy_conf *mpc) 351 { 352 uint64_t labeled; 353 354 #define MPC_FLAG(method, flag) \ 355 if (mpc->mpc_ops->mpo_ ## method != NULL) \ 356 labeled |= (flag); \ 357 358 labeled = 0; 359 MPC_FLAG(cred_init_label, MPC_OBJECT_CRED); 360 MPC_FLAG(proc_init_label, MPC_OBJECT_PROC); 361 MPC_FLAG(vnode_init_label, MPC_OBJECT_VNODE); 362 MPC_FLAG(inpcb_init_label, MPC_OBJECT_INPCB); 363 MPC_FLAG(socket_init_label, MPC_OBJECT_SOCKET); 364 MPC_FLAG(devfs_init_label, MPC_OBJECT_DEVFS); 365 MPC_FLAG(mbuf_init_label, MPC_OBJECT_MBUF); 366 MPC_FLAG(ipq_init_label, MPC_OBJECT_IPQ); 367 MPC_FLAG(ifnet_init_label, MPC_OBJECT_IFNET); 368 MPC_FLAG(bpfdesc_init_label, MPC_OBJECT_BPFDESC); 369 MPC_FLAG(pipe_init_label, MPC_OBJECT_PIPE); 370 MPC_FLAG(mount_init_label, MPC_OBJECT_MOUNT); 371 MPC_FLAG(posixsem_init_label, MPC_OBJECT_POSIXSEM); 372 MPC_FLAG(posixshm_init_label, MPC_OBJECT_POSIXSHM); 373 MPC_FLAG(sysvmsg_init_label, MPC_OBJECT_SYSVMSG); 374 MPC_FLAG(sysvmsq_init_label, MPC_OBJECT_SYSVMSQ); 375 MPC_FLAG(sysvsem_init_label, MPC_OBJECT_SYSVSEM); 376 MPC_FLAG(sysvshm_init_label, MPC_OBJECT_SYSVSHM); 377 MPC_FLAG(syncache_init_label, MPC_OBJECT_SYNCACHE); 378 MPC_FLAG(ip6q_init_label, MPC_OBJECT_IP6Q); 379 380 #undef MPC_FLAG 381 return (labeled); 382 } 383 384 /* 385 * When policies are loaded or unloaded, walk the list of registered policies 386 * and built mac_labeled, a bitmask representing the union of all objects 387 * requiring labels across all policies. 388 */ 389 static void 390 mac_policy_update(void) 391 { 392 struct mac_policy_conf *mpc; 393 394 mac_policy_xlock_assert(); 395 396 mac_labeled = 0; 397 mac_policy_count = 0; 398 LIST_FOREACH(mpc, &mac_static_policy_list, mpc_list) { 399 mac_labeled |= mac_policy_getlabeled(mpc); 400 mac_policy_count++; 401 } 402 LIST_FOREACH(mpc, &mac_policy_list, mpc_list) { 403 mac_labeled |= mac_policy_getlabeled(mpc); 404 mac_policy_count++; 405 } 406 407 cache_fast_lookup_enabled_recalc(); 408 } 409 410 /* 411 * There are frequently used code paths which check for rarely installed 412 * policies. Gross hack below enables doing it in a cheap manner. 413 */ 414 415 #define FPO(f) (offsetof(struct mac_policy_ops, mpo_##f) / sizeof(uintptr_t)) 416 417 struct mac_policy_fastpath_elem { 418 int count; 419 bool *flag; 420 size_t offset; 421 }; 422 423 struct mac_policy_fastpath_elem mac_policy_fastpath_array[] = { 424 { .offset = FPO(priv_check), .flag = &mac_priv_check_fp_flag }, 425 { .offset = FPO(priv_grant), .flag = &mac_priv_grant_fp_flag }, 426 { .offset = FPO(vnode_check_lookup), 427 .flag = &mac_vnode_check_lookup_fp_flag }, 428 { .offset = FPO(vnode_check_readlink), 429 .flag = &mac_vnode_check_readlink_fp_flag }, 430 { .offset = FPO(vnode_check_open), 431 .flag = &mac_vnode_check_open_fp_flag }, 432 { .offset = FPO(vnode_check_stat), 433 .flag = &mac_vnode_check_stat_fp_flag }, 434 { .offset = FPO(vnode_check_read), 435 .flag = &mac_vnode_check_read_fp_flag }, 436 { .offset = FPO(vnode_check_write), 437 .flag = &mac_vnode_check_write_fp_flag }, 438 { .offset = FPO(vnode_check_mmap), 439 .flag = &mac_vnode_check_mmap_fp_flag }, 440 { .offset = FPO(vnode_check_poll), 441 .flag = &mac_vnode_check_poll_fp_flag }, 442 { .offset = FPO(vnode_check_rename_from), 443 .flag = &mac_vnode_check_rename_from_fp_flag }, 444 { .offset = FPO(vnode_check_access), 445 .flag = &mac_vnode_check_access_fp_flag }, 446 { .offset = FPO(pipe_check_stat), 447 .flag = &mac_pipe_check_stat_fp_flag }, 448 { .offset = FPO(pipe_check_poll), 449 .flag = &mac_pipe_check_poll_fp_flag }, 450 { .offset = FPO(ifnet_create_mbuf), 451 .flag = &mac_ifnet_create_mbuf_fp_flag }, 452 { .offset = FPO(ifnet_check_transmit), 453 .flag = &mac_ifnet_check_transmit_fp_flag }, 454 }; 455 456 static void 457 mac_policy_fastpath_enable(struct mac_policy_fastpath_elem *mpfe) 458 { 459 460 MPASS(mpfe->count >= 0); 461 mpfe->count++; 462 if (mpfe->count == 1) { 463 MPASS(*mpfe->flag == false); 464 *mpfe->flag = true; 465 } 466 } 467 468 static void 469 mac_policy_fastpath_disable(struct mac_policy_fastpath_elem *mpfe) 470 { 471 472 MPASS(mpfe->count >= 1); 473 mpfe->count--; 474 if (mpfe->count == 0) { 475 MPASS(*mpfe->flag == true); 476 *mpfe->flag = false; 477 } 478 } 479 480 static void 481 mac_policy_fastpath_register(struct mac_policy_conf *mpc) 482 { 483 struct mac_policy_fastpath_elem *mpfe; 484 uintptr_t **ops; 485 int i; 486 487 mac_policy_xlock_assert(); 488 489 ops = (uintptr_t **)mpc->mpc_ops; 490 for (i = 0; i < nitems(mac_policy_fastpath_array); i++) { 491 mpfe = &mac_policy_fastpath_array[i]; 492 if (ops[mpfe->offset] != NULL) 493 mac_policy_fastpath_enable(mpfe); 494 } 495 } 496 497 static void 498 mac_policy_fastpath_unregister(struct mac_policy_conf *mpc) 499 { 500 struct mac_policy_fastpath_elem *mpfe; 501 uintptr_t **ops; 502 int i; 503 504 mac_policy_xlock_assert(); 505 506 ops = (uintptr_t **)mpc->mpc_ops; 507 for (i = 0; i < nitems(mac_policy_fastpath_array); i++) { 508 mpfe = &mac_policy_fastpath_array[i]; 509 if (ops[mpfe->offset] != NULL) 510 mac_policy_fastpath_disable(mpfe); 511 } 512 } 513 514 #undef FPO 515 516 static int 517 mac_policy_register(struct mac_policy_conf *mpc) 518 { 519 struct mac_policy_conf *tmpc; 520 int error, slot, static_entry; 521 522 error = 0; 523 524 /* 525 * We don't technically need exclusive access while !mac_late, but 526 * hold it for assertion consistency. 527 */ 528 mac_policy_xlock(); 529 530 /* 531 * If the module can potentially be unloaded, or we're loading late, 532 * we have to stick it in the non-static list and pay an extra 533 * performance overhead. Otherwise, we can pay a light locking cost 534 * and stick it in the static list. 535 */ 536 static_entry = (!mac_late && 537 !(mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK)); 538 539 if (static_entry) { 540 LIST_FOREACH(tmpc, &mac_static_policy_list, mpc_list) { 541 if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) { 542 error = EEXIST; 543 goto out; 544 } 545 } 546 } else { 547 LIST_FOREACH(tmpc, &mac_policy_list, mpc_list) { 548 if (strcmp(tmpc->mpc_name, mpc->mpc_name) == 0) { 549 error = EEXIST; 550 goto out; 551 } 552 } 553 } 554 if (mpc->mpc_field_off != NULL) { 555 slot = ffs(mac_slot_offsets_free); 556 if (slot == 0) { 557 error = ENOMEM; 558 goto out; 559 } 560 slot--; 561 mac_slot_offsets_free &= ~(1 << slot); 562 *mpc->mpc_field_off = slot; 563 } 564 mpc->mpc_runtime_flags |= MPC_RUNTIME_FLAG_REGISTERED; 565 566 /* 567 * If we're loading a MAC module after the framework has initialized, 568 * it has to go into the dynamic list. If we're loading it before 569 * we've finished initializing, it can go into the static list with 570 * weaker locker requirements. 571 */ 572 if (static_entry) 573 LIST_INSERT_HEAD(&mac_static_policy_list, mpc, mpc_list); 574 else 575 LIST_INSERT_HEAD(&mac_policy_list, mpc, mpc_list); 576 577 /* 578 * Per-policy initialization. Currently, this takes place under the 579 * exclusive lock, so policies must not sleep in their init method. 580 * In the future, we may want to separate "init" from "start", with 581 * "init" occurring without the lock held. Likewise, on tear-down, 582 * breaking out "stop" from "destroy". 583 */ 584 if (mpc->mpc_ops->mpo_init != NULL) 585 (*(mpc->mpc_ops->mpo_init))(mpc); 586 587 mac_policy_fastpath_register(mpc); 588 589 mac_policy_update(); 590 591 SDT_PROBE1(mac, , policy, register, mpc); 592 printf("Security policy loaded: %s (%s)\n", mpc->mpc_fullname, 593 mpc->mpc_name); 594 595 out: 596 mac_policy_xunlock(); 597 return (error); 598 } 599 600 static int 601 mac_policy_unregister(struct mac_policy_conf *mpc) 602 { 603 604 /* 605 * If we fail the load, we may get a request to unload. Check to see 606 * if we did the run-time registration, and if not, silently succeed. 607 */ 608 mac_policy_xlock(); 609 if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED) == 0) { 610 mac_policy_xunlock(); 611 return (0); 612 } 613 #if 0 614 /* 615 * Don't allow unloading modules with private data. 616 */ 617 if (mpc->mpc_field_off != NULL) { 618 mac_policy_xunlock(); 619 return (EBUSY); 620 } 621 #endif 622 /* 623 * Only allow the unload to proceed if the module is unloadable by 624 * its own definition. 625 */ 626 if ((mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_UNLOADOK) == 0) { 627 mac_policy_xunlock(); 628 return (EBUSY); 629 } 630 631 mac_policy_fastpath_unregister(mpc); 632 633 if (mpc->mpc_ops->mpo_destroy != NULL) 634 (*(mpc->mpc_ops->mpo_destroy))(mpc); 635 636 LIST_REMOVE(mpc, mpc_list); 637 mpc->mpc_runtime_flags &= ~MPC_RUNTIME_FLAG_REGISTERED; 638 mac_policy_update(); 639 mac_policy_xunlock(); 640 641 SDT_PROBE1(mac, , policy, unregister, mpc); 642 printf("Security policy unload: %s (%s)\n", mpc->mpc_fullname, 643 mpc->mpc_name); 644 645 return (0); 646 } 647 648 /* 649 * Allow MAC policy modules to register during boot, etc. 650 */ 651 int 652 mac_policy_modevent(module_t mod, int type, void *data) 653 { 654 struct mac_policy_conf *mpc; 655 int error; 656 657 error = 0; 658 mpc = (struct mac_policy_conf *) data; 659 660 #ifdef MAC_STATIC 661 if (mac_late) { 662 printf("mac_policy_modevent: MAC_STATIC and late\n"); 663 return (EBUSY); 664 } 665 #endif 666 667 SDT_PROBE2(mac, , policy, modevent, type, mpc); 668 switch (type) { 669 case MOD_LOAD: 670 if (mpc->mpc_loadtime_flags & MPC_LOADTIME_FLAG_NOTLATE && 671 mac_late) { 672 printf("mac_policy_modevent: can't load %s policy " 673 "after booting\n", mpc->mpc_name); 674 error = EBUSY; 675 break; 676 } 677 error = mac_policy_register(mpc); 678 break; 679 case MOD_UNLOAD: 680 /* Don't unregister the module if it was never registered. */ 681 if ((mpc->mpc_runtime_flags & MPC_RUNTIME_FLAG_REGISTERED) 682 != 0) 683 error = mac_policy_unregister(mpc); 684 else 685 error = 0; 686 break; 687 default: 688 error = EOPNOTSUPP; 689 break; 690 } 691 692 return (error); 693 } 694 695 /* 696 * Define an error value precedence, and given two arguments, selects the 697 * value with the higher precedence. 698 */ 699 int 700 mac_error_select(int error1, int error2) 701 { 702 703 /* Certain decision-making errors take top priority. */ 704 if (error1 == EDEADLK || error2 == EDEADLK) 705 return (EDEADLK); 706 707 /* Invalid arguments should be reported where possible. */ 708 if (error1 == EINVAL || error2 == EINVAL) 709 return (EINVAL); 710 711 /* Precedence goes to "visibility", with both process and file. */ 712 if (error1 == ESRCH || error2 == ESRCH) 713 return (ESRCH); 714 715 if (error1 == ENOENT || error2 == ENOENT) 716 return (ENOENT); 717 718 /* Precedence goes to DAC/MAC protections. */ 719 if (error1 == EACCES || error2 == EACCES) 720 return (EACCES); 721 722 /* Precedence goes to privilege. */ 723 if (error1 == EPERM || error2 == EPERM) 724 return (EPERM); 725 726 /* Precedence goes to error over success; otherwise, arbitrary. */ 727 if (error1 != 0) 728 return (error1); 729 return (error2); 730 } 731 732 int 733 mac_check_structmac_consistent(struct mac *mac) 734 { 735 736 /* Require that labels have a non-zero length. */ 737 if (mac->m_buflen > MAC_MAX_LABEL_BUF_LEN || 738 mac->m_buflen <= sizeof("")) 739 return (EINVAL); 740 741 return (0); 742 } 743 744 SYSINIT(mac, SI_SUB_MAC, SI_ORDER_FIRST, mac_init, NULL); 745 SYSINIT(mac_late, SI_SUB_MAC_LATE, SI_ORDER_FIRST, mac_late_init, NULL); 746