1 /* $OpenBSD: rtable.c,v 1.77 2022/04/19 15:44:56 bluhm Exp $ */ 2 3 /* 4 * Copyright (c) 2014-2016 Martin Pieuchot 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef _KERNEL 20 #include "kern_compat.h" 21 #else 22 #include <sys/param.h> 23 #include <sys/systm.h> 24 #include <sys/socket.h> 25 #include <sys/malloc.h> 26 #include <sys/queue.h> 27 #include <sys/domain.h> 28 #include <sys/srp.h> 29 #endif 30 31 #include <net/rtable.h> 32 #include <net/route.h> 33 34 /* 35 * Structures used by rtable_get() to retrieve the corresponding 36 * routing table for a given pair of ``af'' and ``rtableid''. 37 * 38 * Note that once allocated routing table heads are never freed. 39 * This way we do not need to reference count them. 40 * 41 * afmap rtmap/dommp 42 * ----------- --------- ----- 43 * | 0 |--------> | 0 | 0 | ... | 0 | Array mapping rtableid (=index) 44 * ----------- --------- ----- to rdomain/loopback (=value). 45 * | AF_INET |. 46 * ----------- `. .---------. .---------. 47 * ... `----> | rtable0 | ... | rtableN | Array of pointers for 48 * ----------- '---------' '---------' IPv4 routing tables 49 * | AF_MPLS | indexed by ``rtableid''. 50 * ----------- 51 */ 52 struct srp *afmap; 53 uint8_t af2idx[AF_MAX+1]; /* To only allocate supported AF */ 54 uint8_t af2idx_max; 55 56 /* Array of routing table pointers. */ 57 struct rtmap { 58 unsigned int limit; 59 void **tbl; 60 }; 61 62 /* 63 * Array of rtableid -> rdomain mapping. 64 * 65 * Only used for the first index as described above. 66 */ 67 struct dommp { 68 unsigned int limit; 69 /* 70 * Array to get the routing domain and loopback interface related to 71 * a routing table. Format: 72 * 73 * 8 unused bits | 16 bits for loopback index | 8 bits for rdomain 74 */ 75 unsigned int *value; 76 }; 77 78 unsigned int rtmap_limit = 0; 79 80 void rtmap_init(void); 81 void rtmap_grow(unsigned int, sa_family_t); 82 void rtmap_dtor(void *, void *); 83 84 struct srp_gc rtmap_gc = SRP_GC_INITIALIZER(rtmap_dtor, NULL); 85 86 void rtable_init_backend(void); 87 void *rtable_alloc(unsigned int, unsigned int, unsigned int); 88 void *rtable_get(unsigned int, sa_family_t); 89 90 void 91 rtmap_init(void) 92 { 93 const struct domain *dp; 94 int i; 95 96 /* Start with a single table for every domain that requires it. */ 97 for (i = 0; (dp = domains[i]) != NULL; i++) { 98 if (dp->dom_rtoffset == 0) 99 continue; 100 101 rtmap_grow(1, dp->dom_family); 102 } 103 104 /* Initialize the rtableid->rdomain mapping table. */ 105 rtmap_grow(1, 0); 106 107 rtmap_limit = 1; 108 } 109 110 /* 111 * Grow the size of the array of routing table for AF ``af'' to ``nlimit''. 112 */ 113 void 114 rtmap_grow(unsigned int nlimit, sa_family_t af) 115 { 116 struct rtmap *map, *nmap; 117 int i; 118 119 KERNEL_ASSERT_LOCKED(); 120 121 KASSERT(nlimit > rtmap_limit); 122 123 nmap = malloc(sizeof(*nmap), M_RTABLE, M_WAITOK); 124 nmap->limit = nlimit; 125 nmap->tbl = mallocarray(nlimit, sizeof(*nmap[0].tbl), M_RTABLE, 126 M_WAITOK|M_ZERO); 127 128 map = srp_get_locked(&afmap[af2idx[af]]); 129 if (map != NULL) { 130 KASSERT(map->limit == rtmap_limit); 131 132 for (i = 0; i < map->limit; i++) 133 nmap->tbl[i] = map->tbl[i]; 134 } 135 136 srp_update_locked(&rtmap_gc, &afmap[af2idx[af]], nmap); 137 } 138 139 void 140 rtmap_dtor(void *null, void *xmap) 141 { 142 struct rtmap *map = xmap; 143 144 /* 145 * doesn't need to be serialized since this is the last reference 146 * to this map. there's nothing to race against. 147 */ 148 free(map->tbl, M_RTABLE, map->limit * sizeof(*map[0].tbl)); 149 free(map, M_RTABLE, sizeof(*map)); 150 } 151 152 void 153 rtable_init(void) 154 { 155 const struct domain *dp; 156 int i; 157 158 KASSERT(sizeof(struct rtmap) == sizeof(struct dommp)); 159 160 /* We use index 0 for the rtable/rdomain map. */ 161 af2idx_max = 1; 162 memset(af2idx, 0, sizeof(af2idx)); 163 164 /* 165 * Compute the maximum supported key length in case the routing 166 * table backend needs it. 167 */ 168 for (i = 0; (dp = domains[i]) != NULL; i++) { 169 if (dp->dom_rtoffset == 0) 170 continue; 171 172 af2idx[dp->dom_family] = af2idx_max++; 173 } 174 rtable_init_backend(); 175 176 /* 177 * Allocate AF-to-id table now that we now how many AFs this 178 * kernel supports. 179 */ 180 afmap = mallocarray(af2idx_max + 1, sizeof(*afmap), M_RTABLE, 181 M_WAITOK|M_ZERO); 182 183 rtmap_init(); 184 185 if (rtable_add(0) != 0) 186 panic("unable to create default routing table"); 187 188 rt_timer_init(); 189 } 190 191 int 192 rtable_add(unsigned int id) 193 { 194 const struct domain *dp; 195 void *tbl; 196 struct rtmap *map; 197 struct dommp *dmm; 198 sa_family_t af; 199 unsigned int off, alen; 200 int i, error = 0; 201 202 if (id > RT_TABLEID_MAX) 203 return (EINVAL); 204 205 KERNEL_LOCK(); 206 207 if (rtable_exists(id)) 208 goto out; 209 210 for (i = 0; (dp = domains[i]) != NULL; i++) { 211 if (dp->dom_rtoffset == 0) 212 continue; 213 214 af = dp->dom_family; 215 off = dp->dom_rtoffset; 216 alen = dp->dom_maxplen; 217 218 if (id >= rtmap_limit) 219 rtmap_grow(id + 1, af); 220 221 tbl = rtable_alloc(id, alen, off); 222 if (tbl == NULL) { 223 error = ENOMEM; 224 goto out; 225 } 226 227 map = srp_get_locked(&afmap[af2idx[af]]); 228 map->tbl[id] = tbl; 229 } 230 231 /* Reflect possible growth. */ 232 if (id >= rtmap_limit) { 233 rtmap_grow(id + 1, 0); 234 rtmap_limit = id + 1; 235 } 236 237 /* Use main rtable/rdomain by default. */ 238 dmm = srp_get_locked(&afmap[0]); 239 dmm->value[id] = 0; 240 out: 241 KERNEL_UNLOCK(); 242 243 return (error); 244 } 245 246 void * 247 rtable_get(unsigned int rtableid, sa_family_t af) 248 { 249 struct rtmap *map; 250 void *tbl = NULL; 251 struct srp_ref sr; 252 253 if (af >= nitems(af2idx) || af2idx[af] == 0) 254 return (NULL); 255 256 map = srp_enter(&sr, &afmap[af2idx[af]]); 257 if (rtableid < map->limit) 258 tbl = map->tbl[rtableid]; 259 srp_leave(&sr); 260 261 return (tbl); 262 } 263 264 int 265 rtable_exists(unsigned int rtableid) 266 { 267 const struct domain *dp; 268 void *tbl; 269 int i; 270 271 for (i = 0; (dp = domains[i]) != NULL; i++) { 272 if (dp->dom_rtoffset == 0) 273 continue; 274 275 tbl = rtable_get(rtableid, dp->dom_family); 276 if (tbl != NULL) 277 return (1); 278 } 279 280 return (0); 281 } 282 283 int 284 rtable_empty(unsigned int rtableid) 285 { 286 const struct domain *dp; 287 int i; 288 struct art_root *tbl; 289 290 for (i = 0; (dp = domains[i]) != NULL; i++) { 291 if (dp->dom_rtoffset == 0) 292 continue; 293 294 tbl = rtable_get(rtableid, dp->dom_family); 295 if (tbl == NULL) 296 continue; 297 if (tbl->ar_root.ref != NULL) 298 return (0); 299 } 300 301 return (1); 302 } 303 304 unsigned int 305 rtable_l2(unsigned int rtableid) 306 { 307 struct dommp *dmm; 308 unsigned int rdomain = 0; 309 struct srp_ref sr; 310 311 dmm = srp_enter(&sr, &afmap[0]); 312 if (rtableid < dmm->limit) 313 rdomain = (dmm->value[rtableid] & RT_TABLEID_MASK); 314 srp_leave(&sr); 315 316 return (rdomain); 317 } 318 319 unsigned int 320 rtable_loindex(unsigned int rtableid) 321 { 322 struct dommp *dmm; 323 unsigned int loifidx = 0; 324 struct srp_ref sr; 325 326 dmm = srp_enter(&sr, &afmap[0]); 327 if (rtableid < dmm->limit) 328 loifidx = (dmm->value[rtableid] >> RT_TABLEID_BITS); 329 srp_leave(&sr); 330 331 return (loifidx); 332 } 333 334 void 335 rtable_l2set(unsigned int rtableid, unsigned int rdomain, unsigned int loifidx) 336 { 337 struct dommp *dmm; 338 unsigned int value; 339 340 KERNEL_ASSERT_LOCKED(); 341 342 if (!rtable_exists(rtableid) || !rtable_exists(rdomain)) 343 return; 344 345 value = (rdomain & RT_TABLEID_MASK) | (loifidx << RT_TABLEID_BITS); 346 347 dmm = srp_get_locked(&afmap[0]); 348 dmm->value[rtableid] = value; 349 } 350 351 352 static inline uint8_t *satoaddr(struct art_root *, struct sockaddr *); 353 354 int an_match(struct art_node *, struct sockaddr *, int); 355 void rtentry_ref(void *, void *); 356 void rtentry_unref(void *, void *); 357 358 void rtable_mpath_insert(struct art_node *, struct rtentry *); 359 360 struct srpl_rc rt_rc = SRPL_RC_INITIALIZER(rtentry_ref, rtentry_unref, NULL); 361 362 void 363 rtable_init_backend(void) 364 { 365 art_init(); 366 } 367 368 void * 369 rtable_alloc(unsigned int rtableid, unsigned int alen, unsigned int off) 370 { 371 return (art_alloc(rtableid, alen, off)); 372 } 373 374 int 375 rtable_setsource(unsigned int rtableid, int af, struct sockaddr *src) 376 { 377 struct art_root *ar; 378 379 if ((ar = rtable_get(rtableid, af)) == NULL) 380 return (EAFNOSUPPORT); 381 382 ar->source = src; 383 384 return (0); 385 } 386 387 struct sockaddr * 388 rtable_getsource(unsigned int rtableid, int af) 389 { 390 struct art_root *ar; 391 392 ar = rtable_get(rtableid, af); 393 if (ar == NULL) 394 return (NULL); 395 396 return (ar->source); 397 } 398 399 void 400 rtable_clearsource(unsigned int rtableid, struct sockaddr *src) 401 { 402 struct sockaddr *addr; 403 404 addr = rtable_getsource(rtableid, src->sa_family); 405 if (addr && (addr->sa_len == src->sa_len)) { 406 if (memcmp(src, addr, addr->sa_len) == 0) { 407 rtable_setsource(rtableid, src->sa_family, NULL); 408 } 409 } 410 } 411 412 struct rtentry * 413 rtable_lookup(unsigned int rtableid, struct sockaddr *dst, 414 struct sockaddr *mask, struct sockaddr *gateway, uint8_t prio) 415 { 416 struct art_root *ar; 417 struct art_node *an; 418 struct rtentry *rt = NULL; 419 struct srp_ref sr, nsr; 420 uint8_t *addr; 421 int plen; 422 423 ar = rtable_get(rtableid, dst->sa_family); 424 if (ar == NULL) 425 return (NULL); 426 427 addr = satoaddr(ar, dst); 428 429 /* No need for a perfect match. */ 430 if (mask == NULL) { 431 an = art_match(ar, addr, &nsr); 432 if (an == NULL) 433 goto out; 434 } else { 435 plen = rtable_satoplen(dst->sa_family, mask); 436 if (plen == -1) 437 return (NULL); 438 439 an = art_lookup(ar, addr, plen, &nsr); 440 441 /* Make sure we've got a perfect match. */ 442 if (!an_match(an, dst, plen)) 443 goto out; 444 } 445 446 SRPL_FOREACH(rt, &sr, &an->an_rtlist, rt_next) { 447 if (prio != RTP_ANY && 448 (rt->rt_priority & RTP_MASK) != (prio & RTP_MASK)) 449 continue; 450 451 if (gateway == NULL) 452 break; 453 454 if (rt->rt_gateway->sa_len == gateway->sa_len && 455 memcmp(rt->rt_gateway, gateway, gateway->sa_len) == 0) 456 break; 457 } 458 if (rt != NULL) 459 rtref(rt); 460 461 SRPL_LEAVE(&sr); 462 out: 463 srp_leave(&nsr); 464 465 return (rt); 466 } 467 468 struct rtentry * 469 rtable_match(unsigned int rtableid, struct sockaddr *dst, uint32_t *src) 470 { 471 struct art_root *ar; 472 struct art_node *an; 473 struct rtentry *rt = NULL; 474 struct srp_ref sr, nsr; 475 uint8_t *addr; 476 int hash; 477 478 ar = rtable_get(rtableid, dst->sa_family); 479 if (ar == NULL) 480 return (NULL); 481 482 addr = satoaddr(ar, dst); 483 484 an = art_match(ar, addr, &nsr); 485 if (an == NULL) 486 goto out; 487 488 rt = SRPL_FIRST(&sr, &an->an_rtlist); 489 rtref(rt); 490 SRPL_LEAVE(&sr); 491 492 /* Gateway selection by Hash-Threshold (RFC 2992) */ 493 if ((hash = rt_hash(rt, dst, src)) != -1) { 494 struct rtentry *mrt; 495 int threshold, npaths = 0; 496 497 KASSERT(hash <= 0xffff); 498 499 SRPL_FOREACH(mrt, &sr, &an->an_rtlist, rt_next) { 500 /* Only count nexthops with the same priority. */ 501 if (mrt->rt_priority == rt->rt_priority) 502 npaths++; 503 } 504 SRPL_LEAVE(&sr); 505 506 threshold = (0xffff / npaths) + 1; 507 508 /* 509 * we have no protection against concurrent modification of the 510 * route list attached to the node, so we won't necessarily 511 * have the same number of routes. for most modifications, 512 * we'll pick a route that we wouldn't have if we only saw the 513 * list before or after the change. if we were going to use 514 * the last available route, but it got removed, we'll hit 515 * the end of the list and then pick the first route. 516 */ 517 518 mrt = SRPL_FIRST(&sr, &an->an_rtlist); 519 while (hash > threshold && mrt != NULL) { 520 if (mrt->rt_priority == rt->rt_priority) 521 hash -= threshold; 522 mrt = SRPL_FOLLOW(&sr, mrt, rt_next); 523 } 524 525 if (mrt != NULL) { 526 rtref(mrt); 527 rtfree(rt); 528 rt = mrt; 529 } 530 SRPL_LEAVE(&sr); 531 } 532 out: 533 srp_leave(&nsr); 534 return (rt); 535 } 536 537 int 538 rtable_insert(unsigned int rtableid, struct sockaddr *dst, 539 struct sockaddr *mask, struct sockaddr *gateway, uint8_t prio, 540 struct rtentry *rt) 541 { 542 struct rtentry *mrt; 543 struct srp_ref sr; 544 struct art_root *ar; 545 struct art_node *an, *prev; 546 uint8_t *addr; 547 int plen; 548 unsigned int rt_flags; 549 int error = 0; 550 551 ar = rtable_get(rtableid, dst->sa_family); 552 if (ar == NULL) 553 return (EAFNOSUPPORT); 554 555 addr = satoaddr(ar, dst); 556 plen = rtable_satoplen(dst->sa_family, mask); 557 if (plen == -1) 558 return (EINVAL); 559 560 rtref(rt); /* guarantee rtfree won't do anything during insert */ 561 rw_enter_write(&ar->ar_lock); 562 563 /* Do not permit exactly the same dst/mask/gw pair. */ 564 an = art_lookup(ar, addr, plen, &sr); 565 srp_leave(&sr); /* an can't go away while we have the lock */ 566 if (an_match(an, dst, plen)) { 567 struct rtentry *mrt; 568 int mpathok = ISSET(rt->rt_flags, RTF_MPATH); 569 570 SRPL_FOREACH_LOCKED(mrt, &an->an_rtlist, rt_next) { 571 if (prio != RTP_ANY && 572 (mrt->rt_priority & RTP_MASK) != (prio & RTP_MASK)) 573 continue; 574 575 if (!mpathok || 576 (mrt->rt_gateway->sa_len == gateway->sa_len && 577 !memcmp(mrt->rt_gateway, gateway, gateway->sa_len))){ 578 error = EEXIST; 579 goto leave; 580 } 581 } 582 } 583 584 an = art_get(dst, plen); 585 if (an == NULL) { 586 error = ENOBUFS; 587 goto leave; 588 } 589 590 /* prepare for immediate operation if insert succeeds */ 591 rt_flags = rt->rt_flags; 592 rt->rt_flags &= ~RTF_MPATH; 593 rt->rt_dest = dst; 594 rt->rt_plen = plen; 595 SRPL_INSERT_HEAD_LOCKED(&rt_rc, &an->an_rtlist, rt, rt_next); 596 597 prev = art_insert(ar, an, addr, plen); 598 if (prev != an) { 599 SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, 600 rt_next); 601 rt->rt_flags = rt_flags; 602 art_put(an); 603 604 if (prev == NULL) { 605 error = ESRCH; 606 goto leave; 607 } 608 609 an = prev; 610 611 mrt = SRPL_FIRST_LOCKED(&an->an_rtlist); 612 KASSERT(mrt != NULL); 613 KASSERT((rt->rt_flags & RTF_MPATH) || mrt->rt_priority != prio); 614 615 /* 616 * An ART node with the same destination/netmask already 617 * exists, MPATH conflict must have been already checked. 618 */ 619 if (rt->rt_flags & RTF_MPATH) { 620 /* 621 * Only keep the RTF_MPATH flag if two routes have 622 * the same gateway. 623 */ 624 rt->rt_flags &= ~RTF_MPATH; 625 SRPL_FOREACH_LOCKED(mrt, &an->an_rtlist, rt_next) { 626 if (mrt->rt_priority == prio) { 627 mrt->rt_flags |= RTF_MPATH; 628 rt->rt_flags |= RTF_MPATH; 629 } 630 } 631 } 632 633 /* Put newly inserted entry at the right place. */ 634 rtable_mpath_insert(an, rt); 635 } 636 leave: 637 rw_exit_write(&ar->ar_lock); 638 rtfree(rt); 639 return (error); 640 } 641 642 int 643 rtable_delete(unsigned int rtableid, struct sockaddr *dst, 644 struct sockaddr *mask, struct rtentry *rt) 645 { 646 struct art_root *ar; 647 struct art_node *an; 648 struct srp_ref sr; 649 uint8_t *addr; 650 int plen; 651 struct rtentry *mrt; 652 int npaths = 0; 653 int error = 0; 654 655 ar = rtable_get(rtableid, dst->sa_family); 656 if (ar == NULL) 657 return (EAFNOSUPPORT); 658 659 addr = satoaddr(ar, dst); 660 plen = rtable_satoplen(dst->sa_family, mask); 661 if (plen == -1) 662 return (EINVAL); 663 664 rtref(rt); /* guarantee rtfree won't do anything under ar_lock */ 665 rw_enter_write(&ar->ar_lock); 666 an = art_lookup(ar, addr, plen, &sr); 667 srp_leave(&sr); /* an can't go away while we have the lock */ 668 669 /* Make sure we've got a perfect match. */ 670 if (!an_match(an, dst, plen)) { 671 error = ESRCH; 672 goto leave; 673 } 674 675 /* 676 * If other multipath route entries are still attached to 677 * this ART node we only have to unlink it. 678 */ 679 SRPL_FOREACH_LOCKED(mrt, &an->an_rtlist, rt_next) 680 npaths++; 681 682 if (npaths > 1) { 683 KASSERT(rt->rt_refcnt >= 1); 684 SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, 685 rt_next); 686 687 mrt = SRPL_FIRST_LOCKED(&an->an_rtlist); 688 if (npaths == 2) 689 mrt->rt_flags &= ~RTF_MPATH; 690 691 goto leave; 692 } 693 694 if (art_delete(ar, an, addr, plen) == NULL) 695 panic("art_delete failed to find node %p", an); 696 697 KASSERT(rt->rt_refcnt >= 1); 698 SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, rt, rtentry, rt_next); 699 art_put(an); 700 701 leave: 702 rw_exit_write(&ar->ar_lock); 703 rtfree(rt); 704 705 return (error); 706 } 707 708 struct rtable_walk_cookie { 709 int (*rwc_func)(struct rtentry *, void *, unsigned int); 710 void *rwc_arg; 711 struct rtentry **rwc_prt; 712 unsigned int rwc_rid; 713 }; 714 715 /* 716 * Helper for rtable_walk to keep the ART code free from any "struct rtentry". 717 */ 718 int 719 rtable_walk_helper(struct art_node *an, void *xrwc) 720 { 721 struct srp_ref sr; 722 struct rtable_walk_cookie *rwc = xrwc; 723 struct rtentry *rt; 724 int error = 0; 725 726 SRPL_FOREACH(rt, &sr, &an->an_rtlist, rt_next) { 727 error = (*rwc->rwc_func)(rt, rwc->rwc_arg, rwc->rwc_rid); 728 if (error != 0) 729 break; 730 } 731 if (rwc->rwc_prt != NULL && rt != NULL) { 732 rtref(rt); 733 *rwc->rwc_prt = rt; 734 } 735 SRPL_LEAVE(&sr); 736 737 return (error); 738 } 739 740 int 741 rtable_walk(unsigned int rtableid, sa_family_t af, struct rtentry **prt, 742 int (*func)(struct rtentry *, void *, unsigned int), void *arg) 743 { 744 struct art_root *ar; 745 struct rtable_walk_cookie rwc; 746 int error; 747 748 ar = rtable_get(rtableid, af); 749 if (ar == NULL) 750 return (EAFNOSUPPORT); 751 752 rwc.rwc_func = func; 753 rwc.rwc_arg = arg; 754 rwc.rwc_prt = prt; 755 rwc.rwc_rid = rtableid; 756 757 error = art_walk(ar, rtable_walk_helper, &rwc); 758 759 return (error); 760 } 761 762 struct rtentry * 763 rtable_iterate(struct rtentry *rt0) 764 { 765 struct rtentry *rt = NULL; 766 struct srp_ref sr; 767 768 rt = SRPL_NEXT(&sr, rt0, rt_next); 769 if (rt != NULL) 770 rtref(rt); 771 SRPL_LEAVE(&sr); 772 rtfree(rt0); 773 return (rt); 774 } 775 776 int 777 rtable_mpath_capable(unsigned int rtableid, sa_family_t af) 778 { 779 return (1); 780 } 781 782 int 783 rtable_mpath_reprio(unsigned int rtableid, struct sockaddr *dst, 784 int plen, uint8_t prio, struct rtentry *rt) 785 { 786 struct art_root *ar; 787 struct art_node *an; 788 struct srp_ref sr; 789 uint8_t *addr; 790 int error = 0; 791 792 ar = rtable_get(rtableid, dst->sa_family); 793 if (ar == NULL) 794 return (EAFNOSUPPORT); 795 796 addr = satoaddr(ar, dst); 797 798 rw_enter_write(&ar->ar_lock); 799 an = art_lookup(ar, addr, plen, &sr); 800 srp_leave(&sr); /* an can't go away while we have the lock */ 801 802 /* Make sure we've got a perfect match. */ 803 if (!an_match(an, dst, plen)) { 804 error = ESRCH; 805 } else if (SRPL_FIRST_LOCKED(&an->an_rtlist) == rt && 806 SRPL_NEXT_LOCKED(rt, rt_next) == NULL) { 807 /* 808 * If there's only one entry on the list do not go 809 * through an insert/remove cycle. This is done to 810 * guarantee that ``an->an_rtlist'' is never empty 811 * when a node is in the tree. 812 */ 813 rt->rt_priority = prio; 814 } else { 815 rtref(rt); /* keep rt alive in between remove and insert */ 816 SRPL_REMOVE_LOCKED(&rt_rc, &an->an_rtlist, 817 rt, rtentry, rt_next); 818 rt->rt_priority = prio; 819 rtable_mpath_insert(an, rt); 820 rtfree(rt); 821 error = EAGAIN; 822 } 823 rw_exit_write(&ar->ar_lock); 824 825 return (error); 826 } 827 828 void 829 rtable_mpath_insert(struct art_node *an, struct rtentry *rt) 830 { 831 struct rtentry *mrt, *prt = NULL; 832 uint8_t prio = rt->rt_priority; 833 834 if ((mrt = SRPL_FIRST_LOCKED(&an->an_rtlist)) == NULL) { 835 SRPL_INSERT_HEAD_LOCKED(&rt_rc, &an->an_rtlist, rt, rt_next); 836 return; 837 } 838 839 /* Iterate until we find the route to be placed after ``rt''. */ 840 while (mrt->rt_priority <= prio && SRPL_NEXT_LOCKED(mrt, rt_next)) { 841 prt = mrt; 842 mrt = SRPL_NEXT_LOCKED(mrt, rt_next); 843 } 844 845 if (mrt->rt_priority <= prio) { 846 SRPL_INSERT_AFTER_LOCKED(&rt_rc, mrt, rt, rt_next); 847 } else if (prt != NULL) { 848 SRPL_INSERT_AFTER_LOCKED(&rt_rc, prt, rt, rt_next); 849 } else { 850 SRPL_INSERT_HEAD_LOCKED(&rt_rc, &an->an_rtlist, rt, rt_next); 851 } 852 } 853 854 /* 855 * Returns 1 if ``an'' perfectly matches (``dst'', ``plen''), 0 otherwise. 856 */ 857 int 858 an_match(struct art_node *an, struct sockaddr *dst, int plen) 859 { 860 struct rtentry *rt; 861 struct srp_ref sr; 862 int match; 863 864 if (an == NULL || an->an_plen != plen) 865 return (0); 866 867 rt = SRPL_FIRST(&sr, &an->an_rtlist); 868 match = (memcmp(rt->rt_dest, dst, dst->sa_len) == 0); 869 SRPL_LEAVE(&sr); 870 871 return (match); 872 } 873 874 void 875 rtentry_ref(void *null, void *xrt) 876 { 877 struct rtentry *rt = xrt; 878 879 rtref(rt); 880 } 881 882 void 883 rtentry_unref(void *null, void *xrt) 884 { 885 struct rtentry *rt = xrt; 886 887 rtfree(rt); 888 } 889 890 /* 891 * Return a pointer to the address (key). This is an heritage from the 892 * BSD radix tree needed to skip the non-address fields from the flavor 893 * of "struct sockaddr" used by this routing table. 894 */ 895 static inline uint8_t * 896 satoaddr(struct art_root *at, struct sockaddr *sa) 897 { 898 return (((uint8_t *)sa) + at->ar_off); 899 } 900 901 /* 902 * Return the prefix length of a mask. 903 */ 904 int 905 rtable_satoplen(sa_family_t af, struct sockaddr *mask) 906 { 907 const struct domain *dp; 908 uint8_t *ap, *ep; 909 int mlen, plen = 0; 910 int i; 911 912 for (i = 0; (dp = domains[i]) != NULL; i++) { 913 if (dp->dom_rtoffset == 0) 914 continue; 915 916 if (af == dp->dom_family) 917 break; 918 } 919 if (dp == NULL) 920 return (-1); 921 922 /* Host route */ 923 if (mask == NULL) 924 return (dp->dom_maxplen); 925 926 mlen = mask->sa_len; 927 928 /* Default route */ 929 if (mlen == 0) 930 return (0); 931 932 ap = (uint8_t *)((uint8_t *)mask) + dp->dom_rtoffset; 933 ep = (uint8_t *)((uint8_t *)mask) + mlen; 934 if (ap > ep) 935 return (-1); 936 937 /* Trim trailing zeroes. */ 938 while (ap < ep && ep[-1] == 0) 939 ep--; 940 941 if (ap == ep) 942 return (0); 943 944 /* "Beauty" adapted from sbin/route/show.c ... */ 945 while (ap < ep) { 946 switch (*ap++) { 947 case 0xff: 948 plen += 8; 949 break; 950 case 0xfe: 951 plen += 7; 952 goto out; 953 case 0xfc: 954 plen += 6; 955 goto out; 956 case 0xf8: 957 plen += 5; 958 goto out; 959 case 0xf0: 960 plen += 4; 961 goto out; 962 case 0xe0: 963 plen += 3; 964 goto out; 965 case 0xc0: 966 plen += 2; 967 goto out; 968 case 0x80: 969 plen += 1; 970 goto out; 971 default: 972 /* Non contiguous mask. */ 973 return (-1); 974 } 975 } 976 977 out: 978 if (plen > dp->dom_maxplen || ap != ep) 979 return -1; 980 981 return (plen); 982 } 983