1 /* $NetBSD: table.c,v 1.28 2018/02/06 09:33:07 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1983, 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgment: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "defs.h" 37 38 #ifdef __NetBSD__ 39 __RCSID("$NetBSD: table.c,v 1.28 2018/02/06 09:33:07 mrg Exp $"); 40 #elif defined(__FreeBSD__) 41 __RCSID("$FreeBSD$"); 42 #else 43 __RCSID("Revision: 2.27 "); 44 #ident "Revision: 2.27 " 45 #endif 46 47 static struct rt_spare *rts_better(struct rt_entry *); 48 static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0}; 49 static void set_need_flash(void); 50 #ifdef _HAVE_SIN_LEN 51 static void masktrim(struct sockaddr_in *ap); 52 #else 53 static void masktrim(struct sockaddr_in_new *ap); 54 #endif 55 56 57 struct radix_node_head *rhead; /* root of the radix tree */ 58 59 int need_flash = 1; /* flash update needed 60 * start =1 to suppress the 1st 61 */ 62 63 struct timeval age_timer; /* next check of old routes */ 64 struct timeval need_kern = { /* need to update kernel table */ 65 EPOCH+MIN_WAITTIME-1, 0 66 }; 67 68 int stopint; 69 70 int total_routes; 71 72 /* zap any old routes through this gateway */ 73 naddr age_bad_gate; 74 75 76 /* It is desirable to "aggregate" routes, to combine differing routes of 77 * the same metric and next hop into a common route with a smaller netmask 78 * or to suppress redundant routes, routes that add no information to 79 * routes with smaller netmasks. 80 * 81 * A route is redundant if and only if any and all routes with smaller 82 * but matching netmasks and nets are the same. Since routes are 83 * kept sorted in the radix tree, redundant routes always come second. 84 * 85 * There are two kinds of aggregations. First, two routes of the same bit 86 * mask and differing only in the least significant bit of the network 87 * number can be combined into a single route with a coarser mask. 88 * 89 * Second, a route can be suppressed in favor of another route with a more 90 * coarse mask provided no incompatible routes with intermediate masks 91 * are present. The second kind of aggregation involves suppressing routes. 92 * A route must not be suppressed if an incompatible route exists with 93 * an intermediate mask, since the suppressed route would be covered 94 * by the intermediate. 95 * 96 * This code relies on the radix tree walk encountering routes 97 * sorted first by address, with the smallest address first. 98 */ 99 100 struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest; 101 102 /* #define DEBUG_AG */ 103 #ifdef DEBUG_AG 104 #define CHECK_AG() {int acnt = 0; struct ag_info *cag; \ 105 for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \ 106 acnt++; \ 107 for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \ 108 acnt++; \ 109 if (acnt != NUM_AG_SLOTS) { \ 110 (void)fflush(stderr); \ 111 abort(); \ 112 } \ 113 } 114 #else 115 #define CHECK_AG() 116 #endif 117 118 119 /* Output the contents of an aggregation table slot. 120 * This function must always be immediately followed with the deletion 121 * of the target slot. 122 */ 123 static void 124 ag_out(struct ag_info *ag, 125 void (*out)(struct ag_info *)) 126 { 127 struct ag_info *ag_cors; 128 naddr bit; 129 130 131 /* Forget it if this route should not be output for split-horizon. */ 132 if (ag->ag_state & AGS_SPLIT_HZ) 133 return; 134 135 /* If we output both the even and odd twins, then the immediate parent, 136 * if it is present, is redundant, unless the parent manages to 137 * aggregate into something coarser. 138 * On successive calls, this code detects the even and odd twins, 139 * and marks the parent. 140 * 141 * Note that the order in which the radix tree code emits routes 142 * ensures that the twins are seen before the parent is emitted. 143 */ 144 ag_cors = ag->ag_cors; 145 if (ag_cors != 0 146 && ag_cors->ag_mask == ag->ag_mask<<1 147 && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) { 148 ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h) 149 ? AGS_REDUN0 150 : AGS_REDUN1); 151 } 152 153 /* Skip it if this route is itself redundant. 154 * 155 * It is ok to change the contents of the slot here, since it is 156 * always deleted next. 157 */ 158 if (ag->ag_state & AGS_REDUN0) { 159 if (ag->ag_state & AGS_REDUN1) 160 return; /* quit if fully redundant */ 161 /* make it finer if it is half-redundant */ 162 bit = (-ag->ag_mask) >> 1; 163 ag->ag_dst_h |= bit; 164 ag->ag_mask |= bit; 165 166 } else if (ag->ag_state & AGS_REDUN1) { 167 /* make it finer if it is half-redundant */ 168 bit = (-ag->ag_mask) >> 1; 169 ag->ag_mask |= bit; 170 } 171 out(ag); 172 } 173 174 175 static void 176 ag_del(struct ag_info *ag) 177 { 178 CHECK_AG(); 179 180 if (ag->ag_cors == 0) 181 ag_corsest = ag->ag_fine; 182 else 183 ag->ag_cors->ag_fine = ag->ag_fine; 184 185 if (ag->ag_fine == 0) 186 ag_finest = ag->ag_cors; 187 else 188 ag->ag_fine->ag_cors = ag->ag_cors; 189 190 ag->ag_fine = ag_avail; 191 ag_avail = ag; 192 193 CHECK_AG(); 194 } 195 196 197 /* Flush routes waiting for aggregation. 198 * This must not suppress a route unless it is known that among all 199 * routes with coarser masks that match it, the one with the longest 200 * mask is appropriate. This is ensured by scanning the routes 201 * in lexical order, and with the most restrictive mask first 202 * among routes to the same destination. 203 */ 204 void 205 ag_flush(naddr lim_dst_h, /* flush routes to here */ 206 naddr lim_mask, /* matching this mask */ 207 void (*out)(struct ag_info *)) 208 { 209 struct ag_info *ag, *ag_cors; 210 naddr dst_h; 211 212 213 for (ag = ag_finest; 214 ag != 0 && ag->ag_mask >= lim_mask; 215 ag = ag_cors) { 216 ag_cors = ag->ag_cors; 217 218 /* work on only the specified routes */ 219 dst_h = ag->ag_dst_h; 220 if ((dst_h & lim_mask) != lim_dst_h) 221 continue; 222 223 if (!(ag->ag_state & AGS_SUPPRESS)) 224 ag_out(ag, out); 225 226 else for ( ; ; ag_cors = ag_cors->ag_cors) { 227 /* Look for a route that can suppress the 228 * current route */ 229 if (ag_cors == 0) { 230 /* failed, so output it and look for 231 * another route to work on 232 */ 233 ag_out(ag, out); 234 break; 235 } 236 237 if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) { 238 /* We found a route with a coarser mask that 239 * aggregates the current target. 240 * 241 * If it has a different next hop, it 242 * cannot replace the target, so output 243 * the target. 244 */ 245 if (ag->ag_gate != ag_cors->ag_gate 246 && !(ag->ag_state & AGS_FINE_GATE) 247 && !(ag_cors->ag_state & AGS_CORS_GATE)) { 248 ag_out(ag, out); 249 break; 250 } 251 252 /* If the coarse route has a good enough 253 * metric, it suppresses the target. 254 * If the suppressed target was redundant, 255 * then mark the suppressor redundant. 256 */ 257 if (ag_cors->ag_pref <= ag->ag_pref) { 258 if (AG_IS_REDUN(ag->ag_state) 259 && ag_cors->ag_mask==ag->ag_mask<<1) { 260 if (ag_cors->ag_dst_h == dst_h) 261 ag_cors->ag_state |= AGS_REDUN0; 262 else 263 ag_cors->ag_state |= AGS_REDUN1; 264 } 265 if (ag->ag_tag != ag_cors->ag_tag) 266 ag_cors->ag_tag = 0; 267 if (ag->ag_nhop != ag_cors->ag_nhop) 268 ag_cors->ag_nhop = 0; 269 break; 270 } 271 } 272 } 273 274 /* That route has either been output or suppressed */ 275 ag_cors = ag->ag_cors; 276 ag_del(ag); 277 } 278 279 CHECK_AG(); 280 } 281 282 283 /* Try to aggregate a route with previous routes. 284 */ 285 void 286 ag_check(naddr dst, 287 naddr mask, 288 naddr gate, 289 naddr nhop, 290 char metric, 291 char pref, 292 u_int new_seqno, 293 u_short tag, 294 u_short state, 295 void (*out)(struct ag_info *)) /* output using this */ 296 { 297 struct ag_info *ag, *nag, *ag_cors; 298 naddr xaddr; 299 int x; 300 301 dst = ntohl(dst); 302 303 /* Punt non-contiguous subnet masks. 304 * 305 * (X & -X) contains a single bit if and only if X is a power of 2. 306 * (X + (X & -X)) == 0 if and only if X is a power of 2. 307 */ 308 if ((mask & -mask) + mask != 0) { 309 struct ag_info nc_ag; 310 311 nc_ag.ag_dst_h = dst; 312 nc_ag.ag_mask = mask; 313 nc_ag.ag_gate = gate; 314 nc_ag.ag_nhop = nhop; 315 nc_ag.ag_metric = metric; 316 nc_ag.ag_pref = pref; 317 nc_ag.ag_tag = tag; 318 nc_ag.ag_state = state; 319 nc_ag.ag_seqno = new_seqno; 320 out(&nc_ag); 321 return; 322 } 323 324 /* Search for the right slot in the aggregation table. 325 */ 326 ag_cors = 0; 327 ag = ag_corsest; 328 while (ag != 0) { 329 if (ag->ag_mask >= mask) 330 break; 331 332 /* Suppress old routes (i.e. combine with compatible routes 333 * with coarser masks) as we look for the right slot in the 334 * aggregation table for the new route. 335 * A route to an address less than the current destination 336 * will not be affected by the current route or any route 337 * seen hereafter. That means it is safe to suppress it. 338 * This check keeps poor routes (e.g. with large hop counts) 339 * from preventing suppression of finer routes. 340 */ 341 if (ag_cors != 0 342 && ag->ag_dst_h < dst 343 && (ag->ag_state & AGS_SUPPRESS) 344 && ag_cors->ag_pref <= ag->ag_pref 345 && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h 346 && (ag_cors->ag_gate == ag->ag_gate 347 || (ag->ag_state & AGS_FINE_GATE) 348 || (ag_cors->ag_state & AGS_CORS_GATE))) { 349 /* If the suppressed target was redundant, 350 * then mark the suppressor redundant. 351 */ 352 if (AG_IS_REDUN(ag->ag_state) 353 && ag_cors->ag_mask == ag->ag_mask<<1) { 354 if (ag_cors->ag_dst_h == dst) 355 ag_cors->ag_state |= AGS_REDUN0; 356 else 357 ag_cors->ag_state |= AGS_REDUN1; 358 } 359 if (ag->ag_tag != ag_cors->ag_tag) 360 ag_cors->ag_tag = 0; 361 if (ag->ag_nhop != ag_cors->ag_nhop) 362 ag_cors->ag_nhop = 0; 363 ag_del(ag); 364 CHECK_AG(); 365 } else { 366 ag_cors = ag; 367 } 368 ag = ag_cors->ag_fine; 369 } 370 371 /* If we find the even/odd twin of the new route, and if the 372 * masks and so forth are equal, we can aggregate them. 373 * We can probably promote one of the pair. 374 * 375 * Since the routes are encountered in lexical order, 376 * the new route must be odd. However, the second or later 377 * times around this loop, it could be the even twin promoted 378 * from the even/odd pair of twins of the finer route. 379 */ 380 while (ag != 0 381 && ag->ag_mask == mask 382 && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) { 383 384 /* Here we know the target route and the route in the current 385 * slot have the same netmasks and differ by at most the 386 * last bit. They are either for the same destination, or 387 * for an even/odd pair of destinations. 388 */ 389 if (ag->ag_dst_h == dst) { 390 /* We have two routes to the same destination. 391 * Routes are encountered in lexical order, so a 392 * route is never promoted until the parent route is 393 * already present. So we know that the new route is 394 * a promoted (or aggregated) pair and the route 395 * already in the slot is the explicit route. 396 * 397 * Prefer the best route if their metrics differ, 398 * or the aggregated one if not, following a sort 399 * of longest-match rule. 400 */ 401 if (pref <= ag->ag_pref) { 402 ag->ag_gate = gate; 403 ag->ag_nhop = nhop; 404 ag->ag_tag = tag; 405 ag->ag_metric = metric; 406 ag->ag_pref = pref; 407 if (ag->ag_seqno < new_seqno) 408 ag->ag_seqno = new_seqno; 409 x = ag->ag_state; 410 ag->ag_state = state; 411 state = x; 412 } 413 414 /* Some bits are set if they are set on either route, 415 * except when the route is for an interface. 416 */ 417 if (!(ag->ag_state & AGS_IF)) 418 ag->ag_state |= (state & (AGS_AGGREGATE_EITHER 419 | AGS_REDUN0 420 | AGS_REDUN1)); 421 return; 422 } 423 424 /* If one of the routes can be promoted and the other can 425 * be suppressed, it may be possible to combine them or 426 * worthwhile to promote one. 427 * 428 * Any route that can be promoted is always 429 * marked to be eligible to be suppressed. 430 */ 431 if (!((state & AGS_AGGREGATE) 432 && (ag->ag_state & AGS_SUPPRESS)) 433 && !((ag->ag_state & AGS_AGGREGATE) 434 && (state & AGS_SUPPRESS))) 435 break; 436 437 /* A pair of even/odd twin routes can be combined 438 * if either is redundant, or if they are via the 439 * same gateway and have the same metric. 440 */ 441 if (AG_IS_REDUN(ag->ag_state) 442 || AG_IS_REDUN(state) 443 || (ag->ag_gate == gate 444 && ag->ag_pref == pref 445 && (state & ag->ag_state & AGS_AGGREGATE) != 0)) { 446 447 /* We have both the even and odd pairs. 448 * Since the routes are encountered in order, 449 * the route in the slot must be the even twin. 450 * 451 * Combine and promote (aggregate) the pair of routes. 452 */ 453 if (new_seqno < ag->ag_seqno) 454 new_seqno = ag->ag_seqno; 455 if (!AG_IS_REDUN(state)) 456 state &= ~AGS_REDUN1; 457 if (AG_IS_REDUN(ag->ag_state)) 458 state |= AGS_REDUN0; 459 else 460 state &= ~AGS_REDUN0; 461 state |= (ag->ag_state & AGS_AGGREGATE_EITHER); 462 if (ag->ag_tag != tag) 463 tag = 0; 464 if (ag->ag_nhop != nhop) 465 nhop = 0; 466 467 /* Get rid of the even twin that was already 468 * in the slot. 469 */ 470 ag_del(ag); 471 472 } else if (ag->ag_pref >= pref 473 && (ag->ag_state & AGS_AGGREGATE)) { 474 /* If we cannot combine the pair, maybe the route 475 * with the worse metric can be promoted. 476 * 477 * Promote the old, even twin, by giving its slot 478 * in the table to the new, odd twin. 479 */ 480 ag->ag_dst_h = dst; 481 482 xaddr = ag->ag_gate; 483 ag->ag_gate = gate; 484 gate = xaddr; 485 486 xaddr = ag->ag_nhop; 487 ag->ag_nhop = nhop; 488 nhop = xaddr; 489 490 x = ag->ag_tag; 491 ag->ag_tag = tag; 492 tag = x; 493 494 /* The promoted route is even-redundant only if the 495 * even twin was fully redundant. It is not 496 * odd-redundant because the odd-twin will still be 497 * in the table. 498 */ 499 x = ag->ag_state; 500 if (!AG_IS_REDUN(x)) 501 x &= ~AGS_REDUN0; 502 x &= ~AGS_REDUN1; 503 ag->ag_state = state; 504 state = x; 505 506 x = ag->ag_metric; 507 ag->ag_metric = metric; 508 metric = x; 509 510 x = ag->ag_pref; 511 ag->ag_pref = pref; 512 pref = x; 513 514 /* take the newest sequence number */ 515 if (new_seqno <= ag->ag_seqno) 516 new_seqno = ag->ag_seqno; 517 else 518 ag->ag_seqno = new_seqno; 519 520 } else { 521 if (!(state & AGS_AGGREGATE)) 522 break; /* cannot promote either twin */ 523 524 /* Promote the new, odd twin by shaving its 525 * mask and address. 526 * The promoted route is odd-redundant only if the 527 * odd twin was fully redundant. It is not 528 * even-redundant because the even twin is still in 529 * the table. 530 */ 531 if (!AG_IS_REDUN(state)) 532 state &= ~AGS_REDUN1; 533 state &= ~AGS_REDUN0; 534 if (new_seqno < ag->ag_seqno) 535 new_seqno = ag->ag_seqno; 536 else 537 ag->ag_seqno = new_seqno; 538 } 539 540 mask <<= 1; 541 dst &= mask; 542 543 if (ag_cors == 0) { 544 ag = ag_corsest; 545 break; 546 } 547 ag = ag_cors; 548 ag_cors = ag->ag_cors; 549 } 550 551 /* When we can no longer promote and combine routes, 552 * flush the old route in the target slot. Also flush 553 * any finer routes that we know will never be aggregated by 554 * the new route. 555 * 556 * In case we moved toward coarser masks, 557 * get back where we belong 558 */ 559 if (ag != 0 560 && ag->ag_mask < mask) { 561 ag_cors = ag; 562 ag = ag->ag_fine; 563 } 564 565 /* Empty the target slot 566 */ 567 if (ag != 0 && ag->ag_mask == mask) { 568 ag_flush(ag->ag_dst_h, ag->ag_mask, out); 569 ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine; 570 } 571 572 #ifdef DEBUG_AG 573 (void)fflush(stderr); 574 if (ag == 0 && ag_cors != ag_finest) 575 abort(); 576 if (ag_cors == 0 && ag != ag_corsest) 577 abort(); 578 if (ag != 0 && ag->ag_cors != ag_cors) 579 abort(); 580 if (ag_cors != 0 && ag_cors->ag_fine != ag) 581 abort(); 582 CHECK_AG(); 583 #endif 584 585 /* Save the new route on the end of the table. 586 */ 587 nag = ag_avail; 588 ag_avail = nag->ag_fine; 589 590 nag->ag_dst_h = dst; 591 nag->ag_mask = mask; 592 nag->ag_gate = gate; 593 nag->ag_nhop = nhop; 594 nag->ag_metric = metric; 595 nag->ag_pref = pref; 596 nag->ag_tag = tag; 597 nag->ag_state = state; 598 nag->ag_seqno = new_seqno; 599 600 nag->ag_fine = ag; 601 if (ag != 0) 602 ag->ag_cors = nag; 603 else 604 ag_finest = nag; 605 nag->ag_cors = ag_cors; 606 if (ag_cors == 0) 607 ag_corsest = nag; 608 else 609 ag_cors->ag_fine = nag; 610 CHECK_AG(); 611 } 612 613 614 static const char * 615 rtm_type_name(u_char type) 616 { 617 static const char *rtm_types[] = { 618 "RTM_ADD", 619 "RTM_DELETE", 620 "RTM_CHANGE", 621 "RTM_GET", 622 "RTM_LOSING", 623 "RTM_REDIRECT", 624 "RTM_MISS", 625 "RTM_LOCK", 626 "RTM_OLDADD", 627 "RTM_OLDDEL", 628 "RTM_RESOLVE", 629 "RTM_NEWADDR", 630 "RTM_DELADDR", 631 #ifdef RTM_OIFINFO 632 "RTM_OIFINFO", 633 #endif 634 "RTM_IFINFO", 635 "RTM_NEWMADDR", 636 "RTM_DELMADDR" 637 }; 638 #define NEW_RTM_PAT "RTM type %#x" 639 static char name0[sizeof(NEW_RTM_PAT)+2]; 640 641 642 if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) 643 || type == 0) { 644 snprintf(name0, sizeof(name0), NEW_RTM_PAT, type); 645 return name0; 646 } else { 647 return rtm_types[type-1]; 648 } 649 #undef NEW_RTM_PAT 650 } 651 652 653 /* Trim a mask in a sockaddr 654 * Produce a length of 0 for an address of 0. 655 * Otherwise produce the index of the first zero byte. 656 */ 657 void 658 #ifdef _HAVE_SIN_LEN 659 masktrim(struct sockaddr_in *ap) 660 #else 661 masktrim(struct sockaddr_in_new *ap) 662 #endif 663 { 664 char *cp; 665 666 if (ap->sin_addr.s_addr == 0) { 667 ap->sin_len = 0; 668 return; 669 } 670 cp = (char *)&ap->sin_addr.s_addr + sizeof(ap->sin_addr.s_addr); 671 while (*--cp == 0) 672 continue; 673 ap->sin_len = cp - (char*)ap + 1; 674 } 675 676 677 /* Tell the kernel to add, delete or change a route 678 */ 679 static void 680 rtioctl(int action, /* RTM_DELETE, etc */ 681 naddr dst, 682 naddr gate, 683 naddr mask, 684 int metric, 685 int flags) 686 { 687 struct { 688 struct rt_msghdr w_rtm; 689 struct sockaddr_in w_dst; 690 struct sockaddr_in w_gate; 691 #ifdef _HAVE_SA_LEN 692 struct sockaddr_in w_mask; 693 #else 694 struct sockaddr_in_new w_mask; 695 #endif 696 } w; 697 long cc; 698 # define PAT " %-10s %s metric=%d flags=%#x" 699 # define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags 700 701 again: 702 memset(&w, 0, sizeof(w)); 703 w.w_rtm.rtm_msglen = sizeof(w); 704 w.w_rtm.rtm_version = RTM_VERSION; 705 w.w_rtm.rtm_type = action; 706 w.w_rtm.rtm_flags = flags; 707 w.w_rtm.rtm_seq = ++rt_sock_seqno; 708 w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY; 709 if (metric != 0 || action == RTM_CHANGE) { 710 w.w_rtm.rtm_rmx.rmx_hopcount = metric; 711 w.w_rtm.rtm_inits |= RTV_HOPCOUNT; 712 } 713 w.w_dst.sin_family = AF_INET; 714 w.w_dst.sin_addr.s_addr = dst; 715 w.w_gate.sin_family = AF_INET; 716 w.w_gate.sin_addr.s_addr = gate; 717 #ifdef _HAVE_SA_LEN 718 w.w_dst.sin_len = sizeof(w.w_dst); 719 w.w_gate.sin_len = sizeof(w.w_gate); 720 #endif 721 if (mask == HOST_MASK) { 722 w.w_rtm.rtm_flags |= RTF_HOST; 723 w.w_rtm.rtm_msglen -= sizeof(w.w_mask); 724 } else { 725 w.w_rtm.rtm_addrs |= RTA_NETMASK; 726 w.w_mask.sin_addr.s_addr = htonl(mask); 727 #ifdef _HAVE_SA_LEN 728 masktrim(&w.w_mask); 729 if (w.w_mask.sin_len == 0) 730 w.w_mask.sin_len = sizeof(long); 731 w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len); 732 #endif 733 } 734 735 #ifndef NO_INSTALL 736 cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); 737 if (cc < 0) { 738 if (errno == ESRCH 739 && (action == RTM_CHANGE || action == RTM_DELETE)) { 740 trace_act("route disappeared before" PAT, ARGS); 741 if (action == RTM_CHANGE) { 742 action = RTM_ADD; 743 goto again; 744 } 745 return; 746 } 747 msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno)); 748 return; 749 } else if (cc != w.w_rtm.rtm_msglen) { 750 msglog("write(rt_sock) wrote %ld instead of %d for" PAT, 751 cc, w.w_rtm.rtm_msglen, ARGS); 752 return; 753 } 754 #endif 755 if (TRACEKERNEL) 756 trace_misc("write kernel" PAT, ARGS); 757 #undef PAT 758 #undef ARGS 759 } 760 761 762 #define KHASH_SIZE 71 /* should be prime */ 763 #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE] 764 static struct khash { 765 struct khash *k_next; 766 naddr k_dst; 767 naddr k_mask; 768 naddr k_gate; 769 short k_metric; 770 u_short k_state; 771 #define KS_NEW 0x001 772 #define KS_DELETE 0x002 /* need to delete the route */ 773 #define KS_ADD 0x004 /* add to the kernel */ 774 #define KS_CHANGE 0x008 /* tell kernel to change the route */ 775 #define KS_DEL_ADD 0x010 /* delete & add to change the kernel */ 776 #define KS_STATIC 0x020 /* Static flag in kernel */ 777 #define KS_GATEWAY 0x040 /* G flag in kernel */ 778 #define KS_DYNAMIC 0x080 /* result of redirect */ 779 #define KS_DELETED 0x100 /* already deleted from kernel */ 780 #define KS_CHECK 0x200 781 #define KS_LOCAL 0x400 782 time_t k_keep; 783 #define K_KEEP_LIM 30 784 time_t k_redirect_time; /* when redirected route 1st seen */ 785 } *khash_bins[KHASH_SIZE]; 786 787 788 static struct khash* 789 kern_find(naddr dst, naddr mask, struct khash ***ppk) 790 { 791 struct khash *k, **pk; 792 793 for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) { 794 if (k->k_dst == dst && k->k_mask == mask) 795 break; 796 } 797 if (ppk != 0) 798 *ppk = pk; 799 return k; 800 } 801 802 803 static struct khash* 804 kern_add(naddr dst, naddr mask) 805 { 806 struct khash *k, **pk; 807 808 k = kern_find(dst, mask, &pk); 809 if (k != 0) 810 return k; 811 812 k = (struct khash *)rtmalloc(sizeof(*k), "kern_add"); 813 814 memset(k, 0, sizeof(*k)); 815 k->k_dst = dst; 816 k->k_mask = mask; 817 k->k_state = KS_NEW; 818 k->k_keep = now.tv_sec; 819 *pk = k; 820 821 return k; 822 } 823 824 825 /* If a kernel route has a non-zero metric, check that it is still in the 826 * daemon table, and not deleted by interfaces coming and going. 827 */ 828 static void 829 kern_check_static(struct khash *k, 830 struct interface *ifp) 831 { 832 struct rt_entry *rt; 833 struct rt_spare new; 834 835 if (k->k_metric == 0) 836 return; 837 838 memset(&new, 0, sizeof(new)); 839 new.rts_ifp = ifp; 840 new.rts_gate = k->k_gate; 841 new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr; 842 new.rts_metric = k->k_metric; 843 new.rts_time = now.tv_sec; 844 845 rt = rtget(k->k_dst, k->k_mask); 846 if (rt != 0) { 847 if (!(rt->rt_state & RS_STATIC)) 848 rtchange(rt, rt->rt_state | RS_STATIC, &new, 0); 849 } else { 850 rtadd(k->k_dst, k->k_mask, RS_STATIC, &new); 851 } 852 } 853 854 855 /* operate on a kernel entry 856 */ 857 static void 858 kern_ioctl(struct khash *k, 859 int action, /* RTM_DELETE, etc */ 860 int flags) 861 862 { 863 switch (action) { 864 case RTM_DELETE: 865 k->k_state &= ~KS_DYNAMIC; 866 if (k->k_state & KS_DELETED) 867 return; 868 k->k_state |= KS_DELETED; 869 break; 870 case RTM_ADD: 871 k->k_state &= ~KS_DELETED; 872 break; 873 case RTM_CHANGE: 874 if (k->k_state & KS_DELETED) { 875 action = RTM_ADD; 876 k->k_state &= ~KS_DELETED; 877 } 878 break; 879 } 880 881 rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags); 882 } 883 884 885 /* add a route the kernel told us 886 */ 887 static void 888 rtm_add(struct rt_msghdr *rtm, 889 struct rt_addrinfo *info, 890 time_t keep) 891 { 892 struct khash *k; 893 struct interface *ifp; 894 naddr mask; 895 896 897 if (rtm->rtm_flags & RTF_HOST) { 898 mask = HOST_MASK; 899 } else if (INFO_MASK(info) != 0) { 900 mask = ntohl(S_ADDR(INFO_MASK(info))); 901 } else { 902 msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type)); 903 return; 904 } 905 906 k = kern_add(S_ADDR(INFO_DST(info)), mask); 907 if (k->k_state & KS_NEW) 908 k->k_keep = now.tv_sec+keep; 909 if (INFO_GATE(info) == 0) { 910 trace_act("note %s without gateway", 911 rtm_type_name(rtm->rtm_type)); 912 k->k_metric = HOPCNT_INFINITY; 913 } else if (INFO_GATE(info)->sa_family != AF_INET) { 914 trace_act("note %s with gateway AF=%d", 915 rtm_type_name(rtm->rtm_type), 916 INFO_GATE(info)->sa_family); 917 k->k_metric = HOPCNT_INFINITY; 918 } else { 919 k->k_gate = S_ADDR(INFO_GATE(info)); 920 k->k_metric = rtm->rtm_rmx.rmx_hopcount; 921 if (k->k_metric < 0) 922 k->k_metric = 0; 923 else if (k->k_metric > HOPCNT_INFINITY-1) 924 k->k_metric = HOPCNT_INFINITY-1; 925 } 926 k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD 927 | KS_DELETED | KS_GATEWAY | KS_STATIC 928 | KS_NEW | KS_CHECK | KS_LOCAL); 929 if (rtm->rtm_flags & RTF_GATEWAY) 930 k->k_state |= KS_GATEWAY; 931 if (rtm->rtm_flags & RTF_STATIC) 932 k->k_state |= KS_STATIC; 933 if (rtm->rtm_flags & RTF_LOCAL) 934 k->k_state |= KS_LOCAL; 935 936 if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { 937 if (INFO_AUTHOR(info) != 0 938 && INFO_AUTHOR(info)->sa_family == AF_INET) 939 ifp = iflookup(S_ADDR(INFO_AUTHOR(info))); 940 else 941 ifp = 0; 942 if (supplier 943 && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) { 944 /* Routers are not supposed to listen to redirects, 945 * so delete it if it came via an unknown interface 946 * or the interface does not have special permission. 947 */ 948 k->k_state &= ~KS_DYNAMIC; 949 k->k_state |= KS_DELETE; 950 LIM_SEC(need_kern, 0); 951 trace_act("mark for deletion redirected %s --> %s" 952 " via %s", 953 addrname(k->k_dst, k->k_mask, 0), 954 naddr_ntoa(k->k_gate), 955 ifp ? ifp->int_name : "unknown interface"); 956 } else { 957 k->k_state |= KS_DYNAMIC; 958 k->k_redirect_time = now.tv_sec; 959 trace_act("accept redirected %s --> %s via %s", 960 addrname(k->k_dst, k->k_mask, 0), 961 naddr_ntoa(k->k_gate), 962 ifp ? ifp->int_name : "unknown interface"); 963 } 964 return; 965 } 966 967 /* If it is not a static route, quit until the next comparison 968 * between the kernel and daemon tables, when it will be deleted. 969 */ 970 if (!(k->k_state & KS_STATIC) && !(k->k_state & KS_LOCAL)) { 971 k->k_state |= KS_DELETE; 972 LIM_SEC(need_kern, k->k_keep); 973 return; 974 } 975 976 /* Put static routes with real metrics into the daemon table so 977 * they can be advertised. 978 * 979 * Find the interface toward the gateway. 980 */ 981 ifp = iflookup(k->k_gate); 982 if (ifp == 0) 983 msglog("static route %s --> %s impossibly lacks ifp", 984 addrname(S_ADDR(INFO_DST(info)), mask, 0), 985 naddr_ntoa(k->k_gate)); 986 987 kern_check_static(k, ifp); 988 } 989 990 991 /* deal with packet loss 992 */ 993 static void 994 rtm_lose(struct rt_msghdr *rtm, 995 struct rt_addrinfo *info) 996 { 997 if (INFO_GATE(info) == 0 998 || INFO_GATE(info)->sa_family != AF_INET) { 999 trace_act("ignore %s without gateway", 1000 rtm_type_name(rtm->rtm_type)); 1001 return; 1002 } 1003 1004 if (rdisc_ok) 1005 rdisc_age(S_ADDR(INFO_GATE(info))); 1006 age(S_ADDR(INFO_GATE(info))); 1007 } 1008 1009 1010 /* Make the gateway slot of an info structure point to something 1011 * useful. If it is not already useful, but it specifies an interface, 1012 * then fill in the sockaddr_in provided and point it there. 1013 */ 1014 static int 1015 get_info_gate(const struct sockaddr **sap, 1016 struct sockaddr_in *rsin) 1017 { 1018 const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)*sap; 1019 struct interface *ifp; 1020 1021 if (sdl == 0) 1022 return 0; 1023 if ((sdl)->sdl_family == AF_INET) 1024 return 1; 1025 if ((sdl)->sdl_family != AF_LINK) 1026 return 0; 1027 1028 ifp = ifwithindex(sdl->sdl_index, 1); 1029 if (ifp == 0) 1030 return 0; 1031 1032 rsin->sin_addr.s_addr = ifp->int_addr; 1033 #ifdef _HAVE_SA_LEN 1034 rsin->sin_len = sizeof(*rsin); 1035 #endif 1036 rsin->sin_family = AF_INET; 1037 *sap = (const struct sockaddr*)rsin; 1038 1039 return 1; 1040 } 1041 1042 1043 /* Clean the kernel table by copying it to the daemon image. 1044 * Eventually the daemon will delete any extra routes. 1045 */ 1046 void 1047 flush_kern(void) 1048 { 1049 static char *sysctl_buf; 1050 static size_t sysctl_buf_size = 0; 1051 size_t needed; 1052 int mib[6]; 1053 char *next, *lim; 1054 struct rt_msghdr *rtm; 1055 struct sockaddr_in gate_sin; 1056 struct rt_addrinfo info; 1057 int i; 1058 struct khash *k; 1059 1060 1061 for (i = 0; i < KHASH_SIZE; i++) { 1062 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1063 k->k_state |= KS_CHECK; 1064 } 1065 } 1066 1067 mib[0] = CTL_NET; 1068 mib[1] = PF_ROUTE; 1069 mib[2] = 0; /* protocol */ 1070 mib[3] = 0; /* wildcard address family */ 1071 mib[4] = NET_RT_DUMP; 1072 mib[5] = 0; /* no flags */ 1073 for (;;) { 1074 if ((needed = sysctl_buf_size) != 0) { 1075 if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0) 1076 break; 1077 if (errno != ENOMEM && errno != EFAULT) 1078 BADERR(1,"flush_kern: sysctl(RT_DUMP)"); 1079 free(sysctl_buf); 1080 needed = 0; 1081 } 1082 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) 1083 BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate"); 1084 /* Kludge around the habit of some systems, such as 1085 * BSD/OS 3.1, to not admit how many routes are in the 1086 * kernel, or at least to be quite wrong. 1087 */ 1088 needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr)); 1089 sysctl_buf = rtmalloc(sysctl_buf_size = needed, 1090 "flush_kern sysctl(RT_DUMP)"); 1091 } 1092 1093 lim = sysctl_buf + needed; 1094 for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) { 1095 rtm = (struct rt_msghdr *)next; 1096 if (rtm->rtm_msglen == 0) { 1097 msglog("zero length kernel route at " 1098 " %#lx in buffer %#lx before %#lx", 1099 (u_long)rtm, (u_long)sysctl_buf, (u_long)lim); 1100 break; 1101 } 1102 1103 rt_xaddrs(&info, 1104 (struct sockaddr *)(rtm+1), 1105 (struct sockaddr *)(next + rtm->rtm_msglen), 1106 rtm->rtm_addrs); 1107 1108 if (INFO_DST(&info) == 0 1109 || INFO_DST(&info)->sa_family != AF_INET) 1110 continue; 1111 1112 /* ignore cloned routes 1113 */ 1114 #if defined(RTF_CLONED) && defined(__bsdi__) 1115 if (rtm->rtm_flags & RTF_CLONED) 1116 continue; 1117 #endif 1118 #if defined(RTF_WASCLONED) && defined(__FreeBSD__) 1119 if (rtm->rtm_flags & RTF_WASCLONED) 1120 continue; 1121 #endif 1122 1123 1124 /* ignore multicast addresses 1125 */ 1126 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1127 continue; 1128 1129 if (!get_info_gate(&INFO_GATE(&info), &gate_sin)) 1130 continue; 1131 1132 /* Note static routes and interface routes, and also 1133 * preload the image of the kernel table so that 1134 * we can later clean it, as well as avoid making 1135 * unneeded changes. Keep the old kernel routes for a 1136 * few seconds to allow a RIP or router-discovery 1137 * response to be heard. 1138 */ 1139 rtm_add(rtm,&info,MIN_WAITTIME); 1140 } 1141 1142 for (i = 0; i < KHASH_SIZE; i++) { 1143 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1144 if (k->k_state & KS_CHECK) { 1145 msglog("%s --> %s disappeared from kernel", 1146 addrname(k->k_dst, k->k_mask, 0), 1147 naddr_ntoa(k->k_gate)); 1148 del_static(k->k_dst, k->k_mask, k->k_gate, 1); 1149 } 1150 } 1151 } 1152 } 1153 1154 1155 /* Listen to announcements from the kernel 1156 */ 1157 void 1158 read_rt(void) 1159 { 1160 long cc; 1161 struct interface *ifp; 1162 struct sockaddr_in gate_sin; 1163 naddr mask, gate; 1164 union { 1165 struct { 1166 struct rt_msghdr rtm; 1167 struct sockaddr addrs[RTAX_MAX]; 1168 } r; 1169 struct if_msghdr ifm; 1170 } m; 1171 char str[100], *strp; 1172 struct rt_addrinfo info; 1173 1174 1175 for (;;) { 1176 cc = read(rt_sock, &m, sizeof(m)); 1177 if (cc <= 0) { 1178 if (cc < 0 && errno != EWOULDBLOCK) 1179 LOGERR("read(rt_sock)"); 1180 return; 1181 } 1182 1183 if (m.r.rtm.rtm_version != RTM_VERSION) { 1184 msglog("bogus routing message version %d", 1185 m.r.rtm.rtm_version); 1186 continue; 1187 } 1188 1189 /* Ignore our own results. 1190 */ 1191 if (m.r.rtm.rtm_type <= RTM_CHANGE 1192 && m.r.rtm.rtm_pid == mypid) { 1193 static int complained = 0; 1194 if (!complained) { 1195 msglog("receiving our own change messages"); 1196 complained = 1; 1197 } 1198 continue; 1199 } 1200 1201 if (m.r.rtm.rtm_type == RTM_IFINFO 1202 || m.r.rtm.rtm_type == RTM_NEWADDR 1203 || m.r.rtm.rtm_type == RTM_DELADDR) { 1204 ifp = ifwithindex(m.ifm.ifm_index, 1205 m.r.rtm.rtm_type != RTM_DELADDR); 1206 if (ifp == 0) 1207 trace_act("note %s with flags %#x" 1208 " for unknown interface index #%d", 1209 rtm_type_name(m.r.rtm.rtm_type), 1210 m.ifm.ifm_flags, 1211 m.ifm.ifm_index); 1212 else 1213 trace_act("note %s with flags %#x for %s", 1214 rtm_type_name(m.r.rtm.rtm_type), 1215 m.ifm.ifm_flags, 1216 ifp->int_name); 1217 1218 /* After being informed of a change to an interface, 1219 * check them all now if the check would otherwise 1220 * be a long time from now, if the interface is 1221 * not known, or if the interface has been turned 1222 * off or on. 1223 */ 1224 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1225 || ifp == 0 1226 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1227 & IFF_UP) != 0) 1228 ifinit_timer.tv_sec = now.tv_sec; 1229 continue; 1230 } 1231 #ifdef RTM_OIFINFO 1232 if (m.r.rtm.rtm_type == RTM_OIFINFO) 1233 continue; /* ignore compat message */ 1234 #endif 1235 1236 strlcpy(str, rtm_type_name(m.r.rtm.rtm_type), sizeof(str)); 1237 strp = &str[strlen(str)]; 1238 if (m.r.rtm.rtm_type <= RTM_CHANGE) { 1239 snprintf(strp, str + sizeof(str) - strp, 1240 " from pid %d",m.r.rtm.rtm_pid); 1241 strp += strlen(strp); 1242 } 1243 1244 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1245 m.r.rtm.rtm_addrs); 1246 1247 if (INFO_DST(&info) == 0) { 1248 trace_act("ignore %s without dst", str); 1249 continue; 1250 } 1251 1252 if (INFO_DST(&info)->sa_family != AF_INET) { 1253 trace_act("ignore %s for AF %d", str, 1254 INFO_DST(&info)->sa_family); 1255 continue; 1256 } 1257 1258 mask = ((INFO_MASK(&info) != 0) 1259 ? ntohl(S_ADDR(INFO_MASK(&info))) 1260 : (m.r.rtm.rtm_flags & RTF_HOST) 1261 ? HOST_MASK 1262 : std_mask(S_ADDR(INFO_DST(&info)))); 1263 1264 snprintf(strp, str + sizeof(str) - strp, ": %s", 1265 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1266 strp += strlen(strp); 1267 1268 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1269 trace_act("ignore multicast %s", str); 1270 continue; 1271 } 1272 1273 #if defined(RTF_CLONED) && defined(__bsdi__) 1274 if (m.r.rtm.rtm_flags & RTF_CLONED) { 1275 trace_act("ignore cloned %s", str); 1276 continue; 1277 } 1278 #endif 1279 #if defined(RTF_WASCLONED) && defined(__FreeBSD__) 1280 if (m.r.rtm.rtm_flags & RTF_WASCLONED) { 1281 trace_act("ignore cloned %s", str); 1282 continue; 1283 } 1284 #endif 1285 1286 if (get_info_gate(&INFO_GATE(&info), &gate_sin)) { 1287 gate = S_ADDR(INFO_GATE(&info)); 1288 snprintf(strp, str + sizeof(str) - strp, 1289 " --> %s", naddr_ntoa(gate)); 1290 strp += strlen(strp); 1291 } else { 1292 gate = 0; 1293 } 1294 1295 if (INFO_AUTHOR(&info) != 0) { 1296 snprintf(strp, str + sizeof(str) - strp, 1297 " by authority of %s", 1298 saddr_ntoa(INFO_AUTHOR(&info))); 1299 strp += strlen(strp); 1300 } 1301 1302 switch (m.r.rtm.rtm_type) { 1303 case RTM_ADD: 1304 case RTM_CHANGE: 1305 case RTM_REDIRECT: 1306 if (m.r.rtm.rtm_errno != 0) { 1307 trace_act("ignore %s with \"%s\" error", 1308 str, strerror(m.r.rtm.rtm_errno)); 1309 } else { 1310 trace_act("%s", str); 1311 rtm_add(&m.r.rtm,&info,0); 1312 } 1313 break; 1314 1315 case RTM_DELETE: 1316 if (m.r.rtm.rtm_errno != 0 1317 && m.r.rtm.rtm_errno != ESRCH) { 1318 trace_act("ignore %s with \"%s\" error", 1319 str, strerror(m.r.rtm.rtm_errno)); 1320 } else { 1321 trace_act("%s", str); 1322 del_static(S_ADDR(INFO_DST(&info)), mask, 1323 gate, 1); 1324 } 1325 break; 1326 1327 case RTM_LOSING: 1328 trace_act("%s", str); 1329 rtm_lose(&m.r.rtm,&info); 1330 break; 1331 1332 default: 1333 trace_act("ignore %s", str); 1334 break; 1335 } 1336 } 1337 } 1338 1339 1340 /* after aggregating, note routes that belong in the kernel 1341 */ 1342 static void 1343 kern_out(struct ag_info *ag) 1344 { 1345 struct khash *k; 1346 1347 1348 /* Do not install bad routes if they are not already present. 1349 * This includes routes that had RS_NET_SYN for interfaces that 1350 * recently died. 1351 */ 1352 if (ag->ag_metric == HOPCNT_INFINITY) { 1353 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1354 if (k == 0) 1355 return; 1356 } else { 1357 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1358 } 1359 1360 if (k->k_state & KS_NEW) { 1361 /* will need to add new entry to the kernel table */ 1362 k->k_state = KS_ADD; 1363 if (ag->ag_state & AGS_GATEWAY) 1364 k->k_state |= KS_GATEWAY; 1365 k->k_gate = ag->ag_gate; 1366 k->k_metric = ag->ag_metric; 1367 return; 1368 } 1369 1370 if ((k->k_state & KS_STATIC) || (k->k_state & KS_LOCAL)) 1371 return; 1372 1373 /* modify existing kernel entry if necessary */ 1374 if (k->k_gate != ag->ag_gate 1375 || k->k_metric != ag->ag_metric) { 1376 /* Must delete bad interface routes etc. to change them. */ 1377 if (k->k_metric == HOPCNT_INFINITY) 1378 k->k_state |= KS_DEL_ADD; 1379 k->k_gate = ag->ag_gate; 1380 k->k_metric = ag->ag_metric; 1381 k->k_state |= KS_CHANGE; 1382 } 1383 1384 /* If the daemon thinks the route should exist, forget 1385 * about any redirections. 1386 * If the daemon thinks the route should exist, eventually 1387 * override manual intervention by the operator. 1388 */ 1389 if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) { 1390 k->k_state &= ~KS_DYNAMIC; 1391 k->k_state |= (KS_ADD | KS_DEL_ADD); 1392 } 1393 1394 if ((k->k_state & KS_GATEWAY) 1395 && !(ag->ag_state & AGS_GATEWAY)) { 1396 k->k_state &= ~KS_GATEWAY; 1397 k->k_state |= (KS_ADD | KS_DEL_ADD); 1398 } else if (!(k->k_state & KS_GATEWAY) 1399 && (ag->ag_state & AGS_GATEWAY)) { 1400 k->k_state |= KS_GATEWAY; 1401 k->k_state |= (KS_ADD | KS_DEL_ADD); 1402 } 1403 1404 /* Deleting-and-adding is necessary to change aspects of a route. 1405 * Just delete instead of deleting and then adding a bad route. 1406 * Otherwise, we want to keep the route in the kernel. 1407 */ 1408 if (k->k_metric == HOPCNT_INFINITY 1409 && (k->k_state & KS_DEL_ADD)) 1410 k->k_state |= KS_DELETE; 1411 else 1412 k->k_state &= ~KS_DELETE; 1413 #undef RT 1414 } 1415 1416 1417 /* ARGSUSED */ 1418 static int 1419 walk_kern(struct radix_node *rn, 1420 struct walkarg *argp UNUSED) 1421 { 1422 #define RT ((struct rt_entry *)rn) 1423 char metric, pref; 1424 u_int ags = 0; 1425 1426 1427 /* Do not install synthetic routes */ 1428 if (RT->rt_state & RS_NET_SYN) 1429 return 0; 1430 1431 if (!(RT->rt_state & RS_IF)) { 1432 /* This is an ordinary route, not for an interface. 1433 */ 1434 1435 /* aggregate, ordinary good routes without regard to 1436 * their metric 1437 */ 1438 pref = 1; 1439 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1440 1441 /* Do not install host routes directly to hosts, to avoid 1442 * interfering with ARP entries in the kernel table. 1443 */ 1444 if (RT_ISHOST(RT) 1445 && ntohl(RT->rt_dst) == RT->rt_gate) 1446 return 0; 1447 1448 } else { 1449 /* This is an interface route. 1450 * Do not install routes for "external" remote interfaces. 1451 */ 1452 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1453 return 0; 1454 1455 /* Interfaces should override received routes. 1456 */ 1457 pref = 0; 1458 ags |= (AGS_IF | AGS_CORS_GATE); 1459 1460 /* If it is not an interface, or an alias for an interface, 1461 * it must be a "gateway." 1462 * 1463 * If it is a "remote" interface, it is also a "gateway" to 1464 * the kernel if is not a alias. 1465 */ 1466 if (RT->rt_ifp == 0 1467 || (RT->rt_ifp->int_state & IS_REMOTE)) 1468 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1469 } 1470 1471 /* If RIP is off and IRDP is on, let the route to the discovered 1472 * route suppress any RIP routes. Eventually the RIP routes 1473 * will time-out and be deleted. This reaches the steady-state 1474 * quicker. 1475 */ 1476 if ((RT->rt_state & RS_RDISC) && rip_sock < 0) 1477 ags |= AGS_CORS_GATE; 1478 1479 metric = RT->rt_metric; 1480 if (metric == HOPCNT_INFINITY) { 1481 /* if the route is dead, so try hard to aggregate. */ 1482 pref = HOPCNT_INFINITY; 1483 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1484 ags &= ~(AGS_IF | AGS_CORS_GATE); 1485 } 1486 1487 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1488 metric,pref, 0, 0, ags, kern_out); 1489 return 0; 1490 #undef RT 1491 } 1492 1493 1494 /* Update the kernel table to match the daemon table. 1495 */ 1496 static void 1497 fix_kern(void) 1498 { 1499 int i; 1500 struct khash *k, **pk; 1501 1502 1503 need_kern = age_timer; 1504 1505 /* Walk daemon table, updating the copy of the kernel table. 1506 */ 1507 (void)rn_walktree(rhead, walk_kern, 0); 1508 ag_flush(0,0,kern_out); 1509 1510 for (i = 0; i < KHASH_SIZE; i++) { 1511 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1512 /* Do not touch static routes */ 1513 if (k->k_state & KS_STATIC) { 1514 kern_check_static(k,0); 1515 pk = &k->k_next; 1516 continue; 1517 } 1518 1519 /* Do not touch local routes */ 1520 if (k->k_state & KS_LOCAL) { 1521 pk = &k->k_next; 1522 continue; 1523 } 1524 1525 /* check hold on routes deleted by the operator */ 1526 if (k->k_keep > now.tv_sec) { 1527 /* ensure we check when the hold is over */ 1528 LIM_SEC(need_kern, k->k_keep); 1529 /* mark for the next cycle */ 1530 k->k_state |= KS_DELETE; 1531 pk = &k->k_next; 1532 continue; 1533 } 1534 1535 if ((k->k_state & KS_DELETE) 1536 && !(k->k_state & KS_DYNAMIC)) { 1537 kern_ioctl(k, RTM_DELETE, 0); 1538 *pk = k->k_next; 1539 free(k); 1540 continue; 1541 } 1542 1543 if (k->k_state & KS_DEL_ADD) 1544 kern_ioctl(k, RTM_DELETE, 0); 1545 1546 if (k->k_state & KS_ADD) { 1547 kern_ioctl(k, RTM_ADD, 1548 ((0 != (k->k_state & (KS_GATEWAY 1549 | KS_DYNAMIC))) 1550 ? RTF_GATEWAY : 0)); 1551 } else if (k->k_state & KS_CHANGE) { 1552 kern_ioctl(k, RTM_CHANGE, 1553 ((0 != (k->k_state & (KS_GATEWAY 1554 | KS_DYNAMIC))) 1555 ? RTF_GATEWAY : 0)); 1556 } 1557 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1558 1559 /* Mark this route to be deleted in the next cycle. 1560 * This deletes routes that disappear from the 1561 * daemon table, since the normal aging code 1562 * will clear the bit for routes that have not 1563 * disappeared from the daemon table. 1564 */ 1565 k->k_state |= KS_DELETE; 1566 pk = &k->k_next; 1567 } 1568 } 1569 } 1570 1571 1572 /* Delete a static route in the image of the kernel table. 1573 */ 1574 void 1575 del_static(naddr dst, 1576 naddr mask, 1577 naddr gate, 1578 int gone) 1579 { 1580 struct khash *k; 1581 struct rt_entry *rt; 1582 1583 /* Just mark it in the table to be deleted next time the kernel 1584 * table is updated. 1585 * If it has already been deleted, mark it as such, and set its 1586 * keep-timer so that it will not be deleted again for a while. 1587 * This lets the operator delete a route added by the daemon 1588 * and add a replacement. 1589 */ 1590 k = kern_find(dst, mask, 0); 1591 if (k != 0 && (gate == 0 || k->k_gate == gate)) { 1592 k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK); 1593 k->k_state |= KS_DELETE; 1594 if (gone) { 1595 k->k_state |= KS_DELETED; 1596 k->k_keep = now.tv_sec + K_KEEP_LIM; 1597 } 1598 } 1599 1600 rt = rtget(dst, mask); 1601 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1602 rtbad(rt); 1603 } 1604 1605 1606 /* Delete all routes generated from ICMP Redirects that use a given gateway, 1607 * as well as old redirected routes. 1608 */ 1609 void 1610 del_redirects(naddr bad_gate, 1611 time_t old) 1612 { 1613 int i; 1614 struct khash *k; 1615 1616 1617 for (i = 0; i < KHASH_SIZE; i++) { 1618 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1619 if (!(k->k_state & KS_DYNAMIC) 1620 || (k->k_state & KS_STATIC)) 1621 continue; 1622 1623 if (k->k_gate != bad_gate 1624 && k->k_redirect_time > old 1625 && !supplier) 1626 continue; 1627 1628 k->k_state |= KS_DELETE; 1629 k->k_state &= ~KS_DYNAMIC; 1630 need_kern.tv_sec = now.tv_sec; 1631 trace_act("mark redirected %s --> %s for deletion", 1632 addrname(k->k_dst, k->k_mask, 0), 1633 naddr_ntoa(k->k_gate)); 1634 } 1635 } 1636 } 1637 1638 1639 /* Start the daemon tables. 1640 */ 1641 extern int max_keylen; 1642 1643 void 1644 rtinit(void) 1645 { 1646 int i; 1647 struct ag_info *ag; 1648 1649 /* Initialize the radix trees */ 1650 max_keylen = sizeof(struct sockaddr_in); 1651 rn_init(); 1652 rn_inithead((void*)&rhead, 32); 1653 1654 /* mark all of the slots in the table free */ 1655 ag_avail = ag_slots; 1656 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1657 ag->ag_fine = ag+1; 1658 ag++; 1659 } 1660 } 1661 1662 1663 #ifdef _HAVE_SIN_LEN 1664 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}}; 1665 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}}; 1666 #else 1667 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1668 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1669 #endif 1670 1671 1672 static void 1673 set_need_flash(void) 1674 { 1675 if (!need_flash) { 1676 need_flash = 1; 1677 /* Do not send the flash update immediately. Wait a little 1678 * while to hear from other routers. 1679 */ 1680 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1681 } 1682 } 1683 1684 1685 /* Get a particular routing table entry 1686 */ 1687 struct rt_entry * 1688 rtget(naddr dst, naddr mask) 1689 { 1690 struct rt_entry *rt; 1691 1692 dst_sock.sin_addr.s_addr = dst; 1693 mask_sock.sin_addr.s_addr = htonl(mask); 1694 masktrim(&mask_sock); 1695 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1696 if (!rt 1697 || rt->rt_dst != dst 1698 || rt->rt_mask != mask) 1699 return 0; 1700 1701 return rt; 1702 } 1703 1704 1705 /* Find a route to dst as the kernel would. 1706 */ 1707 struct rt_entry * 1708 rtfind(naddr dst) 1709 { 1710 dst_sock.sin_addr.s_addr = dst; 1711 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1712 } 1713 1714 1715 /* add a route to the table 1716 */ 1717 void 1718 rtadd(naddr dst, 1719 naddr mask, 1720 u_int state, /* rt_state for the entry */ 1721 struct rt_spare *new) 1722 { 1723 struct rt_entry *rt; 1724 naddr smask; 1725 int i; 1726 struct rt_spare *rts; 1727 1728 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1729 memset(rt, 0, sizeof(*rt)); 1730 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1731 rts->rts_metric = HOPCNT_INFINITY; 1732 1733 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1734 rt->rt_dst = dst; 1735 rt->rt_dst_sock.sin_family = AF_INET; 1736 #ifdef _HAVE_SIN_LEN 1737 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1738 #endif 1739 if (mask != HOST_MASK) { 1740 smask = std_mask(dst); 1741 if ((smask & ~mask) == 0 && mask > smask) 1742 state |= RS_SUBNET; 1743 } 1744 mask_sock.sin_addr.s_addr = htonl(mask); 1745 masktrim(&mask_sock); 1746 rt->rt_mask = mask; 1747 rt->rt_state = state; 1748 rt->rt_spares[0] = *new; 1749 rt->rt_time = now.tv_sec; 1750 rt->rt_poison_metric = HOPCNT_INFINITY; 1751 rt->rt_seqno = update_seqno; 1752 1753 if (++total_routes == MAX_ROUTES) 1754 msglog("have maximum (%d) routes", total_routes); 1755 if (TRACEACTIONS) 1756 trace_add_del("Add", rt); 1757 1758 need_kern.tv_sec = now.tv_sec; 1759 set_need_flash(); 1760 1761 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1762 rhead, rt->rt_nodes)) { 1763 msglog("rnh_addaddr() failed for %s mask=%#lx", 1764 naddr_ntoa(dst), (u_long)mask); 1765 free(rt); 1766 } 1767 } 1768 1769 1770 /* notice a changed route 1771 */ 1772 void 1773 rtchange(struct rt_entry *rt, 1774 u_int state, /* new state bits */ 1775 struct rt_spare *new, 1776 char *label) 1777 { 1778 if (rt->rt_metric != new->rts_metric) { 1779 /* Fix the kernel immediately if it seems the route 1780 * has gone bad, since there may be a working route that 1781 * aggregates this route. 1782 */ 1783 if (new->rts_metric == HOPCNT_INFINITY) { 1784 need_kern.tv_sec = now.tv_sec; 1785 if (new->rts_time >= now.tv_sec - EXPIRE_TIME) 1786 new->rts_time = now.tv_sec - EXPIRE_TIME; 1787 } 1788 rt->rt_seqno = update_seqno; 1789 set_need_flash(); 1790 } 1791 1792 if (rt->rt_gate != new->rts_gate) { 1793 need_kern.tv_sec = now.tv_sec; 1794 rt->rt_seqno = update_seqno; 1795 set_need_flash(); 1796 } 1797 1798 state |= (rt->rt_state & RS_SUBNET); 1799 1800 /* Keep various things from deciding ageless routes are stale. 1801 */ 1802 if (!AGE_RT(state, new->rts_ifp)) 1803 new->rts_time = now.tv_sec; 1804 1805 if (TRACEACTIONS) 1806 trace_change(rt, state, new, 1807 label ? label : "Chg "); 1808 1809 rt->rt_state = state; 1810 rt->rt_spares[0] = *new; 1811 } 1812 1813 1814 /* check for a better route among the spares 1815 */ 1816 static struct rt_spare * 1817 rts_better(struct rt_entry *rt) 1818 { 1819 struct rt_spare *rts, *rts1; 1820 int i; 1821 1822 /* find the best alternative among the spares */ 1823 rts = rt->rt_spares+1; 1824 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1825 if (BETTER_LINK(rt,rts1,rts)) 1826 rts = rts1; 1827 } 1828 1829 return rts; 1830 } 1831 1832 1833 /* switch to a backup route 1834 */ 1835 void 1836 rtswitch(struct rt_entry *rt, 1837 struct rt_spare *rts) 1838 { 1839 struct rt_spare swap; 1840 char label[20]; 1841 1842 /* Do not change permanent routes */ 1843 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1844 | RS_NET_SYN | RS_IF))) 1845 return; 1846 1847 /* find the best alternative among the spares */ 1848 if (rts == 0) 1849 rts = rts_better(rt); 1850 1851 /* Do not bother if it is not worthwhile. 1852 */ 1853 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1854 return; 1855 1856 swap = rt->rt_spares[0]; 1857 (void)snprintf(label, sizeof(label), "Use #%d", 1858 (int)(rts - rt->rt_spares)); 1859 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label); 1860 if (swap.rts_metric == HOPCNT_INFINITY) { 1861 *rts = rts_empty; 1862 } else { 1863 *rts = swap; 1864 } 1865 } 1866 1867 1868 void 1869 rtdelete(struct rt_entry *rt) 1870 { 1871 struct khash *k; 1872 1873 1874 if (TRACEACTIONS) 1875 trace_add_del("Del", rt); 1876 1877 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1878 if (k != 0) { 1879 k->k_state |= KS_DELETE; 1880 need_kern.tv_sec = now.tv_sec; 1881 } 1882 1883 dst_sock.sin_addr.s_addr = rt->rt_dst; 1884 mask_sock.sin_addr.s_addr = htonl(rt->rt_mask); 1885 masktrim(&mask_sock); 1886 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1887 rhead)) { 1888 msglog("rnh_deladdr() failed"); 1889 } else { 1890 free(rt); 1891 total_routes--; 1892 } 1893 } 1894 1895 1896 void 1897 rts_delete(struct rt_entry *rt, 1898 struct rt_spare *rts) 1899 { 1900 trace_upslot(rt, rts, &rts_empty); 1901 *rts = rts_empty; 1902 } 1903 1904 1905 /* Get rid of a bad route, and try to switch to a replacement. 1906 */ 1907 void 1908 rtbad(struct rt_entry *rt) 1909 { 1910 struct rt_spare new; 1911 1912 /* Poison the route */ 1913 new = rt->rt_spares[0]; 1914 new.rts_metric = HOPCNT_INFINITY; 1915 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0); 1916 rtswitch(rt, 0); 1917 } 1918 1919 1920 /* Junk a RS_NET_SYN or RS_LOCAL route, 1921 * unless it is needed by another interface. 1922 */ 1923 void 1924 rtbad_sub(struct rt_entry *rt) 1925 { 1926 struct interface *ifp, *ifp1; 1927 struct intnet *intnetp; 1928 u_int state; 1929 1930 1931 ifp1 = 0; 1932 state = 0; 1933 1934 if (rt->rt_state & RS_LOCAL) { 1935 /* Is this the route through loopback for the interface? 1936 * If so, see if it is used by any other interfaces, such 1937 * as a point-to-point interface with the same local address. 1938 */ 1939 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1940 /* Retain it if another interface needs it. 1941 */ 1942 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1943 state |= RS_LOCAL; 1944 ifp1 = ifp; 1945 break; 1946 } 1947 } 1948 1949 } 1950 1951 if (!(state & RS_LOCAL)) { 1952 /* Retain RIPv1 logical network route if there is another 1953 * interface that justifies it. 1954 */ 1955 if (rt->rt_state & RS_NET_SYN) { 1956 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1957 if ((ifp->int_state & IS_NEED_NET_SYN) 1958 && rt->rt_mask == ifp->int_std_mask 1959 && rt->rt_dst == ifp->int_std_addr) { 1960 state |= RS_NET_SYN; 1961 ifp1 = ifp; 1962 break; 1963 } 1964 } 1965 } 1966 1967 /* or if there is an authority route that needs it. */ 1968 for (intnetp = intnets; 1969 intnetp != 0; 1970 intnetp = intnetp->intnet_next) { 1971 if (intnetp->intnet_addr == rt->rt_dst 1972 && intnetp->intnet_mask == rt->rt_mask) { 1973 state |= (RS_NET_SYN | RS_NET_INT); 1974 break; 1975 } 1976 } 1977 } 1978 1979 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1980 struct rt_spare new = rt->rt_spares[0]; 1981 new.rts_ifp = ifp1; 1982 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state), 1983 &new, 0); 1984 } else { 1985 rtbad(rt); 1986 } 1987 } 1988 1989 1990 /* Called while walking the table looking for sick interfaces 1991 * or after a time change. 1992 */ 1993 /* ARGSUSED */ 1994 int 1995 walk_bad(struct radix_node *rn, 1996 struct walkarg *argp UNUSED) 1997 { 1998 #define RT ((struct rt_entry *)rn) 1999 struct rt_spare *rts; 2000 int i; 2001 2002 2003 /* fix any spare routes through the interface 2004 */ 2005 rts = RT->rt_spares; 2006 for (i = NUM_SPARES; i != 1; i--) { 2007 rts++; 2008 if (rts->rts_metric < HOPCNT_INFINITY 2009 && (rts->rts_ifp == 0 2010 || (rts->rts_ifp->int_state & IS_BROKE))) 2011 rts_delete(RT, rts); 2012 } 2013 2014 /* Deal with the main route 2015 */ 2016 /* finished if it has been handled before or if its interface is ok 2017 */ 2018 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 2019 return 0; 2020 2021 /* Bad routes for other than interfaces are easy. 2022 */ 2023 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 2024 rtbad(RT); 2025 return 0; 2026 } 2027 2028 rtbad_sub(RT); 2029 return 0; 2030 #undef RT 2031 } 2032 2033 2034 /* Check the age of an individual route. 2035 */ 2036 /* ARGSUSED */ 2037 static int 2038 walk_age(struct radix_node *rn, 2039 struct walkarg *argp UNUSED) 2040 { 2041 #define RT ((struct rt_entry *)rn) 2042 struct interface *ifp; 2043 struct rt_spare *rts; 2044 int i; 2045 2046 2047 /* age all of the spare routes, including the primary route 2048 * currently in use 2049 */ 2050 rts = RT->rt_spares; 2051 for (i = NUM_SPARES; i != 0; i--, rts++) { 2052 2053 ifp = rts->rts_ifp; 2054 if (i == NUM_SPARES) { 2055 if (!AGE_RT(RT->rt_state, ifp)) { 2056 /* Keep various things from deciding ageless 2057 * routes are stale 2058 */ 2059 rts->rts_time = now.tv_sec; 2060 continue; 2061 } 2062 2063 /* forget RIP routes after RIP has been turned off. 2064 */ 2065 if (rip_sock < 0) { 2066 rtdelete(RT); 2067 return 0; 2068 } 2069 } 2070 2071 /* age failing routes 2072 */ 2073 if (age_bad_gate == rts->rts_gate 2074 && rts->rts_time >= now_stale) { 2075 rts->rts_time -= SUPPLY_INTERVAL; 2076 } 2077 2078 /* trash the spare routes when they go bad */ 2079 if (rts->rts_metric < HOPCNT_INFINITY 2080 && now_garbage > rts->rts_time 2081 && i != NUM_SPARES) 2082 rts_delete(RT, rts); 2083 } 2084 2085 2086 /* finished if the active route is still fresh */ 2087 if (now_stale <= RT->rt_time) 2088 return 0; 2089 2090 /* try to switch to an alternative */ 2091 rtswitch(RT, 0); 2092 2093 /* Delete a dead route after it has been publically mourned. */ 2094 if (now_garbage > RT->rt_time) { 2095 rtdelete(RT); 2096 return 0; 2097 } 2098 2099 /* Start poisoning a bad route before deleting it. */ 2100 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) { 2101 struct rt_spare new = RT->rt_spares[0]; 2102 new.rts_metric = HOPCNT_INFINITY; 2103 rtchange(RT, RT->rt_state, &new, 0); 2104 } 2105 return 0; 2106 } 2107 2108 2109 /* Watch for dead routes and interfaces. 2110 */ 2111 void 2112 age(naddr bad_gate) 2113 { 2114 struct interface *ifp; 2115 int need_query = 0; 2116 2117 /* If not listening to RIP, there is no need to age the routes in 2118 * the table. 2119 */ 2120 age_timer.tv_sec = (now.tv_sec 2121 + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); 2122 2123 /* Check for dead IS_REMOTE interfaces by timing their 2124 * transmissions. 2125 */ 2126 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 2127 if (!(ifp->int_state & IS_REMOTE)) 2128 continue; 2129 2130 /* ignore unreachable remote interfaces */ 2131 if (!check_remote(ifp)) 2132 continue; 2133 2134 /* Restore remote interface that has become reachable 2135 */ 2136 if (ifp->int_state & IS_BROKE) 2137 if_ok(ifp, "remote "); 2138 2139 if (ifp->int_act_time != NEVER 2140 && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { 2141 msglog("remote interface %s to %s timed out after" 2142 " %lld:%lld", 2143 ifp->int_name, 2144 naddr_ntoa(ifp->int_dstaddr), 2145 (long long)(now.tv_sec - ifp->int_act_time)/60, 2146 (long long)(now.tv_sec - ifp->int_act_time)%60); 2147 if_sick(ifp); 2148 } 2149 2150 /* If we have not heard from the other router 2151 * recently, ask it. 2152 */ 2153 if (now.tv_sec >= ifp->int_query_time) { 2154 ifp->int_query_time = NEVER; 2155 need_query = 1; 2156 } 2157 } 2158 2159 /* Age routes. */ 2160 age_bad_gate = bad_gate; 2161 (void)rn_walktree(rhead, walk_age, 0); 2162 2163 /* delete old redirected routes to keep the kernel table small 2164 * and prevent blackholes 2165 */ 2166 del_redirects(bad_gate, now.tv_sec-STALE_TIME); 2167 2168 /* Update the kernel routing table. */ 2169 fix_kern(); 2170 2171 /* poke reticent remote gateways */ 2172 if (need_query) 2173 rip_query(); 2174 } 2175
Indexes created Sun Sep 21 20:09:37 GMT 2025