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