1/* $NetBSD: table.c,v 1.23 2008/12/28 20:15:21 christos 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 1.23 2008/12/28 20:15:21 christos Exp $"); 40#elif defined(__FreeBSD__) 41__RCSID("$FreeBSD$"); 42#else 43__RCSID("Revision: 2.27 "); 44#ident "Revision: 2.27 " 45#endif 46 47static struct rt_spare *rts_better(struct rt_entry *); 48static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0}; 49static void set_need_flash(void); 50#ifdef _HAVE_SIN_LEN 51static void masktrim(struct sockaddr_in *ap); 52#else 53static void masktrim(struct sockaddr_in_new *ap); 54#endif 55 56 57struct radix_node_head *rhead; /* root of the radix tree */ 58 59int need_flash = 1; /* flash update needed 60 * start =1 to suppress the 1st 61 */ 62 63struct timeval age_timer; /* next check of old routes */ 64struct timeval need_kern = { /* need to update kernel table */ 65 EPOCH+MIN_WAITTIME-1, 0 66}; 67 68int stopint; 69 70int total_routes; 71 72/* zap any old routes through this gateway */ 73naddr 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 100struct 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 */ 123static void 124ag_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 175static void 176ag_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 */ 204void 205ag_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 */ 285void 286ag_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 614static const char * 615rtm_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 */ 657void 658#ifdef _HAVE_SIN_LEN 659masktrim(struct sockaddr_in *ap) 660#else 661masktrim(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+1); 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 */ 679static void 680rtioctl(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 701again: 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] 764static 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 time_t k_keep; 782#define K_KEEP_LIM 30 783 time_t k_redirect_time; /* when redirected route 1st seen */ 784} *khash_bins[KHASH_SIZE]; 785 786 787static struct khash* 788kern_find(naddr dst, naddr mask, struct khash ***ppk) 789{ 790 struct khash *k, **pk; 791 792 for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) { 793 if (k->k_dst == dst && k->k_mask == mask) 794 break; 795 } 796 if (ppk != 0) 797 *ppk = pk; 798 return k; 799} 800 801 802static struct khash* 803kern_add(naddr dst, naddr mask) 804{ 805 struct khash *k, **pk; 806 807 k = kern_find(dst, mask, &pk); 808 if (k != 0) 809 return k; 810 811 k = (struct khash *)rtmalloc(sizeof(*k), "kern_add"); 812 813 memset(k, 0, sizeof(*k)); 814 k->k_dst = dst; 815 k->k_mask = mask; 816 k->k_state = KS_NEW; 817 k->k_keep = now.tv_sec; 818 *pk = k; 819 820 return k; 821} 822 823 824/* If a kernel route has a non-zero metric, check that it is still in the 825 * daemon table, and not deleted by interfaces coming and going. 826 */ 827static void 828kern_check_static(struct khash *k, 829 struct interface *ifp) 830{ 831 struct rt_entry *rt; 832 struct rt_spare new; 833 834 if (k->k_metric == 0) 835 return; 836 837 memset(&new, 0, sizeof(new)); 838 new.rts_ifp = ifp; 839 new.rts_gate = k->k_gate; 840 new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr; 841 new.rts_metric = k->k_metric; 842 new.rts_time = now.tv_sec; 843 844 rt = rtget(k->k_dst, k->k_mask); 845 if (rt != 0) { 846 if (!(rt->rt_state & RS_STATIC)) 847 rtchange(rt, rt->rt_state | RS_STATIC, &new, 0); 848 } else { 849 rtadd(k->k_dst, k->k_mask, RS_STATIC, &new); 850 } 851} 852 853 854/* operate on a kernel entry 855 */ 856static void 857kern_ioctl(struct khash *k, 858 int action, /* RTM_DELETE, etc */ 859 int flags) 860 861{ 862 switch (action) { 863 case RTM_DELETE: 864 k->k_state &= ~KS_DYNAMIC; 865 if (k->k_state & KS_DELETED) 866 return; 867 k->k_state |= KS_DELETED; 868 break; 869 case RTM_ADD: 870 k->k_state &= ~KS_DELETED; 871 break; 872 case RTM_CHANGE: 873 if (k->k_state & KS_DELETED) { 874 action = RTM_ADD; 875 k->k_state &= ~KS_DELETED; 876 } 877 break; 878 } 879 880 rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags); 881} 882 883 884/* add a route the kernel told us 885 */ 886static void 887rtm_add(struct rt_msghdr *rtm, 888 struct rt_addrinfo *info, 889 time_t keep) 890{ 891 struct khash *k; 892 struct interface *ifp; 893 naddr mask; 894 895 896 if (rtm->rtm_flags & RTF_HOST) { 897 mask = HOST_MASK; 898 } else if (INFO_MASK(info) != 0) { 899 mask = ntohl(S_ADDR(INFO_MASK(info))); 900 } else { 901 msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type)); 902 return; 903 } 904 905 k = kern_add(S_ADDR(INFO_DST(info)), mask); 906 if (k->k_state & KS_NEW) 907 k->k_keep = now.tv_sec+keep; 908 if (INFO_GATE(info) == 0) { 909 trace_act("note %s without gateway", 910 rtm_type_name(rtm->rtm_type)); 911 k->k_metric = HOPCNT_INFINITY; 912 } else if (INFO_GATE(info)->sa_family != AF_INET) { 913 trace_act("note %s with gateway AF=%d", 914 rtm_type_name(rtm->rtm_type), 915 INFO_GATE(info)->sa_family); 916 k->k_metric = HOPCNT_INFINITY; 917 } else { 918 k->k_gate = S_ADDR(INFO_GATE(info)); 919 k->k_metric = rtm->rtm_rmx.rmx_hopcount; 920 if (k->k_metric < 0) 921 k->k_metric = 0; 922 else if (k->k_metric > HOPCNT_INFINITY-1) 923 k->k_metric = HOPCNT_INFINITY-1; 924 } 925 k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD 926 | KS_DELETED | KS_GATEWAY | KS_STATIC 927 | KS_NEW | KS_CHECK); 928 if (rtm->rtm_flags & RTF_GATEWAY) 929 k->k_state |= KS_GATEWAY; 930 if (rtm->rtm_flags & RTF_STATIC) 931 k->k_state |= KS_STATIC; 932 933 if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { 934 if (INFO_AUTHOR(info) != 0 935 && INFO_AUTHOR(info)->sa_family == AF_INET) 936 ifp = iflookup(S_ADDR(INFO_AUTHOR(info))); 937 else 938 ifp = 0; 939 if (supplier 940 && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) { 941 /* Routers are not supposed to listen to redirects, 942 * so delete it if it came via an unknown interface 943 * or the interface does not have special permission. 944 */ 945 k->k_state &= ~KS_DYNAMIC; 946 k->k_state |= KS_DELETE; 947 LIM_SEC(need_kern, 0); 948 trace_act("mark for deletion redirected %s --> %s" 949 " via %s", 950 addrname(k->k_dst, k->k_mask, 0), 951 naddr_ntoa(k->k_gate), 952 ifp ? ifp->int_name : "unknown interface"); 953 } else { 954 k->k_state |= KS_DYNAMIC; 955 k->k_redirect_time = now.tv_sec; 956 trace_act("accept redirected %s --> %s via %s", 957 addrname(k->k_dst, k->k_mask, 0), 958 naddr_ntoa(k->k_gate), 959 ifp ? ifp->int_name : "unknown interface"); 960 } 961 return; 962 } 963 964 /* If it is not a static route, quit until the next comparison 965 * between the kernel and daemon tables, when it will be deleted. 966 */ 967 if (!(k->k_state & KS_STATIC)) { 968 k->k_state |= KS_DELETE; 969 LIM_SEC(need_kern, k->k_keep); 970 return; 971 } 972 973 /* Put static routes with real metrics into the daemon table so 974 * they can be advertised. 975 * 976 * Find the interface toward the gateway. 977 */ 978 ifp = iflookup(k->k_gate); 979 if (ifp == 0) 980 msglog("static route %s --> %s impossibly lacks ifp", 981 addrname(S_ADDR(INFO_DST(info)), mask, 0), 982 naddr_ntoa(k->k_gate)); 983 984 kern_check_static(k, ifp); 985} 986 987 988/* deal with packet loss 989 */ 990static void 991rtm_lose(struct rt_msghdr *rtm, 992 struct rt_addrinfo *info) 993{ 994 if (INFO_GATE(info) == 0 995 || INFO_GATE(info)->sa_family != AF_INET) { 996 trace_act("ignore %s without gateway", 997 rtm_type_name(rtm->rtm_type)); 998 return; 999 } 1000 1001 if (rdisc_ok) 1002 rdisc_age(S_ADDR(INFO_GATE(info))); 1003 age(S_ADDR(INFO_GATE(info))); 1004} 1005 1006 1007/* Make the gateway slot of an info structure point to something 1008 * useful. If it is not already useful, but it specifies an interface, 1009 * then fill in the sockaddr_in provided and point it there. 1010 */ 1011static int 1012get_info_gate(const struct sockaddr **sap, 1013 struct sockaddr_in *rsin) 1014{ 1015 const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)*sap; 1016 struct interface *ifp; 1017 1018 if (sdl == 0) 1019 return 0; 1020 if ((sdl)->sdl_family == AF_INET) 1021 return 1; 1022 if ((sdl)->sdl_family != AF_LINK) 1023 return 0; 1024 1025 ifp = ifwithindex(sdl->sdl_index, 1); 1026 if (ifp == 0) 1027 return 0; 1028 1029 rsin->sin_addr.s_addr = ifp->int_addr; 1030#ifdef _HAVE_SA_LEN 1031 rsin->sin_len = sizeof(*rsin); 1032#endif 1033 rsin->sin_family = AF_INET; 1034 *sap = (const struct sockaddr*)rsin; 1035 1036 return 1; 1037} 1038 1039 1040/* Clean the kernel table by copying it to the daemon image. 1041 * Eventually the daemon will delete any extra routes. 1042 */ 1043void 1044flush_kern(void) 1045{ 1046 static char *sysctl_buf; 1047 static size_t sysctl_buf_size = 0; 1048 size_t needed; 1049 int mib[6]; 1050 char *next, *lim; 1051 struct rt_msghdr *rtm; 1052 struct sockaddr_in gate_sin; 1053 struct rt_addrinfo info; 1054 int i; 1055 struct khash *k; 1056 1057 1058 for (i = 0; i < KHASH_SIZE; i++) { 1059 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1060 k->k_state |= KS_CHECK; 1061 } 1062 } 1063 1064 mib[0] = CTL_NET; 1065 mib[1] = PF_ROUTE; 1066 mib[2] = 0; /* protocol */ 1067 mib[3] = 0; /* wildcard address family */ 1068 mib[4] = NET_RT_DUMP; 1069 mib[5] = 0; /* no flags */ 1070 for (;;) { 1071 if ((needed = sysctl_buf_size) != 0) { 1072 if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0) 1073 break; 1074 if (errno != ENOMEM && errno != EFAULT) 1075 BADERR(1,"flush_kern: sysctl(RT_DUMP)"); 1076 free(sysctl_buf); 1077 needed = 0; 1078 } 1079 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) 1080 BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate"); 1081 /* Kludge around the habit of some systems, such as 1082 * BSD/OS 3.1, to not admit how many routes are in the 1083 * kernel, or at least to be quite wrong. 1084 */ 1085 needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr)); 1086 sysctl_buf = rtmalloc(sysctl_buf_size = needed, 1087 "flush_kern sysctl(RT_DUMP)"); 1088 } 1089 1090 lim = sysctl_buf + needed; 1091 for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) { 1092 rtm = (struct rt_msghdr *)next; 1093 if (rtm->rtm_msglen == 0) { 1094 msglog("zero length kernel route at " 1095 " %#lx in buffer %#lx before %#lx", 1096 (u_long)rtm, (u_long)sysctl_buf, (u_long)lim); 1097 break; 1098 } 1099 1100 rt_xaddrs(&info, 1101 (struct sockaddr *)(rtm+1), 1102 (struct sockaddr *)(next + rtm->rtm_msglen), 1103 rtm->rtm_addrs); 1104 1105 if (INFO_DST(&info) == 0 1106 || INFO_DST(&info)->sa_family != AF_INET) 1107 continue; 1108 1109 /* ignore ARP table entries on systems with a merged route 1110 * and ARP table. 1111 */ 1112 if (rtm->rtm_flags & RTF_LLINFO) 1113 continue; 1114 1115 /* ignore cloned routes 1116 */ 1117#if defined(RTF_CLONED) && defined(__bsdi__) 1118 if (rtm->rtm_flags & RTF_CLONED) 1119 continue; 1120#endif 1121#if defined(RTF_WASCLONED) && defined(__FreeBSD__) 1122 if (rtm->rtm_flags & RTF_WASCLONED) 1123 continue; 1124#endif 1125 1126 1127 /* ignore multicast addresses 1128 */ 1129 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1130 continue; 1131 1132 if (!get_info_gate(&INFO_GATE(&info), &gate_sin)) 1133 continue; 1134 1135 /* Note static routes and interface routes, and also 1136 * preload the image of the kernel table so that 1137 * we can later clean it, as well as avoid making 1138 * unneeded changes. Keep the old kernel routes for a 1139 * few seconds to allow a RIP or router-discovery 1140 * response to be heard. 1141 */ 1142 rtm_add(rtm,&info,MIN_WAITTIME); 1143 } 1144 1145 for (i = 0; i < KHASH_SIZE; i++) { 1146 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1147 if (k->k_state & KS_CHECK) { 1148 msglog("%s --> %s disappeared from kernel", 1149 addrname(k->k_dst, k->k_mask, 0), 1150 naddr_ntoa(k->k_gate)); 1151 del_static(k->k_dst, k->k_mask, k->k_gate, 1); 1152 } 1153 } 1154 } 1155} 1156 1157 1158/* Listen to announcements from the kernel 1159 */ 1160void 1161read_rt(void) 1162{ 1163 long cc; 1164 struct interface *ifp; 1165 struct sockaddr_in gate_sin; 1166 naddr mask, gate; 1167 union { 1168 struct { 1169 struct rt_msghdr rtm; 1170 struct sockaddr addrs[RTAX_MAX]; 1171 } r; 1172 struct if_msghdr ifm; 1173 } m; 1174 char str[100], *strp; 1175 struct rt_addrinfo info; 1176 1177 1178 for (;;) { 1179 cc = read(rt_sock, &m, sizeof(m)); 1180 if (cc <= 0) { 1181 if (cc < 0 && errno != EWOULDBLOCK) 1182 LOGERR("read(rt_sock)"); 1183 return; 1184 } 1185 1186 if (m.r.rtm.rtm_version != RTM_VERSION) { 1187 msglog("bogus routing message version %d", 1188 m.r.rtm.rtm_version); 1189 continue; 1190 } 1191 1192 /* Ignore our own results. 1193 */ 1194 if (m.r.rtm.rtm_type <= RTM_CHANGE 1195 && m.r.rtm.rtm_pid == mypid) { 1196 static int complained = 0; 1197 if (!complained) { 1198 msglog("receiving our own change messages"); 1199 complained = 1; 1200 } 1201 continue; 1202 } 1203 1204 if (m.r.rtm.rtm_type == RTM_IFINFO 1205 || m.r.rtm.rtm_type == RTM_NEWADDR 1206 || m.r.rtm.rtm_type == RTM_DELADDR) { 1207 ifp = ifwithindex(m.ifm.ifm_index, 1208 m.r.rtm.rtm_type != RTM_DELADDR); 1209 if (ifp == 0) 1210 trace_act("note %s with flags %#x" 1211 " for unknown interface index #%d", 1212 rtm_type_name(m.r.rtm.rtm_type), 1213 m.ifm.ifm_flags, 1214 m.ifm.ifm_index); 1215 else 1216 trace_act("note %s with flags %#x for %s", 1217 rtm_type_name(m.r.rtm.rtm_type), 1218 m.ifm.ifm_flags, 1219 ifp->int_name); 1220 1221 /* After being informed of a change to an interface, 1222 * check them all now if the check would otherwise 1223 * be a long time from now, if the interface is 1224 * not known, or if the interface has been turned 1225 * off or on. 1226 */ 1227 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1228 || ifp == 0 1229 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1230 & IFF_UP) != 0) 1231 ifinit_timer.tv_sec = now.tv_sec; 1232 continue; 1233 } 1234#ifdef RTM_OIFINFO 1235 if (m.r.rtm.rtm_type == RTM_OIFINFO) 1236 continue; /* ignore compat message */ 1237#endif 1238 1239 strlcpy(str, rtm_type_name(m.r.rtm.rtm_type), sizeof(str)); 1240 strp = &str[strlen(str)]; 1241 if (m.r.rtm.rtm_type <= RTM_CHANGE) { 1242 snprintf(strp, str + sizeof(str) - strp, 1243 " from pid %d",m.r.rtm.rtm_pid); 1244 strp += strlen(strp); 1245 } 1246 1247 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1248 m.r.rtm.rtm_addrs); 1249 1250 if (INFO_DST(&info) == 0) { 1251 trace_act("ignore %s without dst", str); 1252 continue; 1253 } 1254 1255 if (INFO_DST(&info)->sa_family != AF_INET) { 1256 trace_act("ignore %s for AF %d", str, 1257 INFO_DST(&info)->sa_family); 1258 continue; 1259 } 1260 1261 mask = ((INFO_MASK(&info) != 0) 1262 ? ntohl(S_ADDR(INFO_MASK(&info))) 1263 : (m.r.rtm.rtm_flags & RTF_HOST) 1264 ? HOST_MASK 1265 : std_mask(S_ADDR(INFO_DST(&info)))); 1266 1267 snprintf(strp, str + sizeof(str) - strp, ": %s", 1268 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1269 strp += strlen(strp); 1270 1271 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1272 trace_act("ignore multicast %s", str); 1273 continue; 1274 } 1275 1276 if (m.r.rtm.rtm_flags & RTF_LLINFO) { 1277 trace_act("ignore ARP %s", str); 1278 continue; 1279 } 1280 1281#if defined(RTF_CLONED) && defined(__bsdi__) 1282 if (m.r.rtm.rtm_flags & RTF_CLONED) { 1283 trace_act("ignore cloned %s", str); 1284 continue; 1285 } 1286#endif 1287#if defined(RTF_WASCLONED) && defined(__FreeBSD__) 1288 if (m.r.rtm.rtm_flags & RTF_WASCLONED) { 1289 trace_act("ignore cloned %s", str); 1290 continue; 1291 } 1292#endif 1293 1294 if (get_info_gate(&INFO_GATE(&info), &gate_sin)) { 1295 gate = S_ADDR(INFO_GATE(&info)); 1296 snprintf(strp, str + sizeof(str) - strp, 1297 " --> %s", naddr_ntoa(gate)); 1298 strp += strlen(strp); 1299 } else { 1300 gate = 0; 1301 } 1302 1303 if (INFO_AUTHOR(&info) != 0) 1304 snprintf(strp, str + sizeof(str) - strp, 1305 " by authority of %s", 1306 saddr_ntoa(INFO_AUTHOR(&info))); 1307 strp += strlen(strp); 1308 1309 switch (m.r.rtm.rtm_type) { 1310 case RTM_ADD: 1311 case RTM_CHANGE: 1312 case RTM_REDIRECT: 1313 if (m.r.rtm.rtm_errno != 0) { 1314 trace_act("ignore %s with \"%s\" error", 1315 str, strerror(m.r.rtm.rtm_errno)); 1316 } else { 1317 trace_act("%s", str); 1318 rtm_add(&m.r.rtm,&info,0); 1319 } 1320 break; 1321 1322 case RTM_DELETE: 1323 if (m.r.rtm.rtm_errno != 0 1324 && m.r.rtm.rtm_errno != ESRCH) { 1325 trace_act("ignore %s with \"%s\" error", 1326 str, strerror(m.r.rtm.rtm_errno)); 1327 } else { 1328 trace_act("%s", str); 1329 del_static(S_ADDR(INFO_DST(&info)), mask, 1330 gate, 1); 1331 } 1332 break; 1333 1334 case RTM_LOSING: 1335 trace_act("%s", str); 1336 rtm_lose(&m.r.rtm,&info); 1337 break; 1338 1339 default: 1340 trace_act("ignore %s", str); 1341 break; 1342 } 1343 } 1344} 1345 1346 1347/* after aggregating, note routes that belong in the kernel 1348 */ 1349static void 1350kern_out(struct ag_info *ag) 1351{ 1352 struct khash *k; 1353 1354 1355 /* Do not install bad routes if they are not already present. 1356 * This includes routes that had RS_NET_SYN for interfaces that 1357 * recently died. 1358 */ 1359 if (ag->ag_metric == HOPCNT_INFINITY) { 1360 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1361 if (k == 0) 1362 return; 1363 } else { 1364 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1365 } 1366 1367 if (k->k_state & KS_NEW) { 1368 /* will need to add new entry to the kernel table */ 1369 k->k_state = KS_ADD; 1370 if (ag->ag_state & AGS_GATEWAY) 1371 k->k_state |= KS_GATEWAY; 1372 k->k_gate = ag->ag_gate; 1373 k->k_metric = ag->ag_metric; 1374 return; 1375 } 1376 1377 if (k->k_state & KS_STATIC) 1378 return; 1379 1380 /* modify existing kernel entry if necessary */ 1381 if (k->k_gate != ag->ag_gate 1382 || k->k_metric != ag->ag_metric) { 1383 /* Must delete bad interface routes etc. to change them. */ 1384 if (k->k_metric == HOPCNT_INFINITY) 1385 k->k_state |= KS_DEL_ADD; 1386 k->k_gate = ag->ag_gate; 1387 k->k_metric = ag->ag_metric; 1388 k->k_state |= KS_CHANGE; 1389 } 1390 1391 /* If the daemon thinks the route should exist, forget 1392 * about any redirections. 1393 * If the daemon thinks the route should exist, eventually 1394 * override manual intervention by the operator. 1395 */ 1396 if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) { 1397 k->k_state &= ~KS_DYNAMIC; 1398 k->k_state |= (KS_ADD | KS_DEL_ADD); 1399 } 1400 1401 if ((k->k_state & KS_GATEWAY) 1402 && !(ag->ag_state & AGS_GATEWAY)) { 1403 k->k_state &= ~KS_GATEWAY; 1404 k->k_state |= (KS_ADD | KS_DEL_ADD); 1405 } else if (!(k->k_state & KS_GATEWAY) 1406 && (ag->ag_state & AGS_GATEWAY)) { 1407 k->k_state |= KS_GATEWAY; 1408 k->k_state |= (KS_ADD | KS_DEL_ADD); 1409 } 1410 1411 /* Deleting-and-adding is necessary to change aspects of a route. 1412 * Just delete instead of deleting and then adding a bad route. 1413 * Otherwise, we want to keep the route in the kernel. 1414 */ 1415 if (k->k_metric == HOPCNT_INFINITY 1416 && (k->k_state & KS_DEL_ADD)) 1417 k->k_state |= KS_DELETE; 1418 else 1419 k->k_state &= ~KS_DELETE; 1420#undef RT 1421} 1422 1423 1424/* ARGSUSED */ 1425static int 1426walk_kern(struct radix_node *rn, 1427 struct walkarg *argp UNUSED) 1428{ 1429#define RT ((struct rt_entry *)rn) 1430 char metric, pref; 1431 u_int ags = 0; 1432 1433 1434 /* Do not install synthetic routes */ 1435 if (RT->rt_state & RS_NET_SYN) 1436 return 0; 1437 1438 if (!(RT->rt_state & RS_IF)) { 1439 /* This is an ordinary route, not for an interface. 1440 */ 1441 1442 /* aggregate, ordinary good routes without regard to 1443 * their metric 1444 */ 1445 pref = 1; 1446 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1447 1448 /* Do not install host routes directly to hosts, to avoid 1449 * interfering with ARP entries in the kernel table. 1450 */ 1451 if (RT_ISHOST(RT) 1452 && ntohl(RT->rt_dst) == RT->rt_gate) 1453 return 0; 1454 1455 } else { 1456 /* This is an interface route. 1457 * Do not install routes for "external" remote interfaces. 1458 */ 1459 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1460 return 0; 1461 1462 /* Interfaces should override received routes. 1463 */ 1464 pref = 0; 1465 ags |= (AGS_IF | AGS_CORS_GATE); 1466 1467 /* If it is not an interface, or an alias for an interface, 1468 * it must be a "gateway." 1469 * 1470 * If it is a "remote" interface, it is also a "gateway" to 1471 * the kernel if is not a alias. 1472 */ 1473 if (RT->rt_ifp == 0 1474 || (RT->rt_ifp->int_state & IS_REMOTE)) 1475 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1476 } 1477 1478 /* If RIP is off and IRDP is on, let the route to the discovered 1479 * route suppress any RIP routes. Eventually the RIP routes 1480 * will time-out and be deleted. This reaches the steady-state 1481 * quicker. 1482 */ 1483 if ((RT->rt_state & RS_RDISC) && rip_sock < 0) 1484 ags |= AGS_CORS_GATE; 1485 1486 metric = RT->rt_metric; 1487 if (metric == HOPCNT_INFINITY) { 1488 /* if the route is dead, so try hard to aggregate. */ 1489 pref = HOPCNT_INFINITY; 1490 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1491 ags &= ~(AGS_IF | AGS_CORS_GATE); 1492 } 1493 1494 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1495 metric,pref, 0, 0, ags, kern_out); 1496 return 0; 1497#undef RT 1498} 1499 1500 1501/* Update the kernel table to match the daemon table. 1502 */ 1503static void 1504fix_kern(void) 1505{ 1506 int i; 1507 struct khash *k, **pk; 1508 1509 1510 need_kern = age_timer; 1511 1512 /* Walk daemon table, updating the copy of the kernel table. 1513 */ 1514 (void)rn_walktree(rhead, walk_kern, 0); 1515 ag_flush(0,0,kern_out); 1516 1517 for (i = 0; i < KHASH_SIZE; i++) { 1518 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1519 /* Do not touch static routes */ 1520 if (k->k_state & KS_STATIC) { 1521 kern_check_static(k,0); 1522 pk = &k->k_next; 1523 continue; 1524 } 1525 1526 /* check hold on routes deleted by the operator */ 1527 if (k->k_keep > now.tv_sec) { 1528 /* ensure we check when the hold is over */ 1529 LIM_SEC(need_kern, k->k_keep); 1530 /* mark for the next cycle */ 1531 k->k_state |= KS_DELETE; 1532 pk = &k->k_next; 1533 continue; 1534 } 1535 1536 if ((k->k_state & KS_DELETE) 1537 && !(k->k_state & KS_DYNAMIC)) { 1538 kern_ioctl(k, RTM_DELETE, 0); 1539 *pk = k->k_next; 1540 free(k); 1541 continue; 1542 } 1543 1544 if (k->k_state & KS_DEL_ADD) 1545 kern_ioctl(k, RTM_DELETE, 0); 1546 1547 if (k->k_state & KS_ADD) { 1548 kern_ioctl(k, RTM_ADD, 1549 ((0 != (k->k_state & (KS_GATEWAY 1550 | KS_DYNAMIC))) 1551 ? RTF_GATEWAY : 0)); 1552 } else if (k->k_state & KS_CHANGE) { 1553 kern_ioctl(k, RTM_CHANGE, 1554 ((0 != (k->k_state & (KS_GATEWAY 1555 | KS_DYNAMIC))) 1556 ? RTF_GATEWAY : 0)); 1557 } 1558 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1559 1560 /* Mark this route to be deleted in the next cycle. 1561 * This deletes routes that disappear from the 1562 * daemon table, since the normal aging code 1563 * will clear the bit for routes that have not 1564 * disappeared from the daemon table. 1565 */ 1566 k->k_state |= KS_DELETE; 1567 pk = &k->k_next; 1568 } 1569 } 1570} 1571 1572 1573/* Delete a static route in the image of the kernel table. 1574 */ 1575void 1576del_static(naddr dst, 1577 naddr mask, 1578 naddr gate, 1579 int gone) 1580{ 1581 struct khash *k; 1582 struct rt_entry *rt; 1583 1584 /* Just mark it in the table to be deleted next time the kernel 1585 * table is updated. 1586 * If it has already been deleted, mark it as such, and set its 1587 * keep-timer so that it will not be deleted again for a while. 1588 * This lets the operator delete a route added by the daemon 1589 * and add a replacement. 1590 */ 1591 k = kern_find(dst, mask, 0); 1592 if (k != 0 && (gate == 0 || k->k_gate == gate)) { 1593 k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK); 1594 k->k_state |= KS_DELETE; 1595 if (gone) { 1596 k->k_state |= KS_DELETED; 1597 k->k_keep = now.tv_sec + K_KEEP_LIM; 1598 } 1599 } 1600 1601 rt = rtget(dst, mask); 1602 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1603 rtbad(rt); 1604} 1605 1606 1607/* Delete all routes generated from ICMP Redirects that use a given gateway, 1608 * as well as old redirected routes. 1609 */ 1610void 1611del_redirects(naddr bad_gate, 1612 time_t old) 1613{ 1614 int i; 1615 struct khash *k; 1616 1617 1618 for (i = 0; i < KHASH_SIZE; i++) { 1619 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1620 if (!(k->k_state & KS_DYNAMIC) 1621 || (k->k_state & KS_STATIC)) 1622 continue; 1623 1624 if (k->k_gate != bad_gate 1625 && k->k_redirect_time > old 1626 && !supplier) 1627 continue; 1628 1629 k->k_state |= KS_DELETE; 1630 k->k_state &= ~KS_DYNAMIC; 1631 need_kern.tv_sec = now.tv_sec; 1632 trace_act("mark redirected %s --> %s for deletion", 1633 addrname(k->k_dst, k->k_mask, 0), 1634 naddr_ntoa(k->k_gate)); 1635 } 1636 } 1637} 1638 1639 1640/* Start the daemon tables. 1641 */ 1642extern int max_keylen; 1643 1644void 1645rtinit(void) 1646{ 1647 int i; 1648 struct ag_info *ag; 1649 1650 /* Initialize the radix trees */ 1651 max_keylen = sizeof(struct sockaddr_in); 1652 rn_init(); 1653 rn_inithead((void*)&rhead, 32); 1654 1655 /* mark all of the slots in the table free */ 1656 ag_avail = ag_slots; 1657 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1658 ag->ag_fine = ag+1; 1659 ag++; 1660 } 1661} 1662 1663 1664#ifdef _HAVE_SIN_LEN 1665static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}}; 1666static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}}; 1667#else 1668static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1669static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1670#endif 1671 1672 1673static void 1674set_need_flash(void) 1675{ 1676 if (!need_flash) { 1677 need_flash = 1; 1678 /* Do not send the flash update immediately. Wait a little 1679 * while to hear from other routers. 1680 */ 1681 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1682 } 1683} 1684 1685 1686/* Get a particular routing table entry 1687 */ 1688struct rt_entry * 1689rtget(naddr dst, naddr mask) 1690{ 1691 struct rt_entry *rt; 1692 1693 dst_sock.sin_addr.s_addr = dst; 1694 mask_sock.sin_addr.s_addr = htonl(mask); 1695 masktrim(&mask_sock); 1696 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1697 if (!rt 1698 || rt->rt_dst != dst 1699 || rt->rt_mask != mask) 1700 return 0; 1701 1702 return rt; 1703} 1704 1705 1706/* Find a route to dst as the kernel would. 1707 */ 1708struct rt_entry * 1709rtfind(naddr dst) 1710{ 1711 dst_sock.sin_addr.s_addr = dst; 1712 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1713} 1714 1715 1716/* add a route to the table 1717 */ 1718void 1719rtadd(naddr dst, 1720 naddr mask, 1721 u_int state, /* rt_state for the entry */ 1722 struct rt_spare *new) 1723{ 1724 struct rt_entry *rt; 1725 naddr smask; 1726 int i; 1727 struct rt_spare *rts; 1728 1729 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1730 memset(rt, 0, sizeof(*rt)); 1731 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1732 rts->rts_metric = HOPCNT_INFINITY; 1733 1734 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1735 rt->rt_dst = dst; 1736 rt->rt_dst_sock.sin_family = AF_INET; 1737#ifdef _HAVE_SIN_LEN 1738 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1739#endif 1740 if (mask != HOST_MASK) { 1741 smask = std_mask(dst); 1742 if ((smask & ~mask) == 0 && mask > smask) 1743 state |= RS_SUBNET; 1744 } 1745 mask_sock.sin_addr.s_addr = htonl(mask); 1746 masktrim(&mask_sock); 1747 rt->rt_mask = mask; 1748 rt->rt_state = state; 1749 rt->rt_spares[0] = *new; 1750 rt->rt_time = now.tv_sec; 1751 rt->rt_poison_metric = HOPCNT_INFINITY; 1752 rt->rt_seqno = update_seqno; 1753 1754 if (++total_routes == MAX_ROUTES) 1755 msglog("have maximum (%d) routes", total_routes); 1756 if (TRACEACTIONS) 1757 trace_add_del("Add", rt); 1758 1759 need_kern.tv_sec = now.tv_sec; 1760 set_need_flash(); 1761 1762 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1763 rhead, rt->rt_nodes)) { 1764 msglog("rnh_addaddr() failed for %s mask=%#lx", 1765 naddr_ntoa(dst), (u_long)mask); 1766 free(rt); 1767 } 1768} 1769 1770 1771/* notice a changed route 1772 */ 1773void 1774rtchange(struct rt_entry *rt, 1775 u_int state, /* new state bits */ 1776 struct rt_spare *new, 1777 char *label) 1778{ 1779 if (rt->rt_metric != new->rts_metric) { 1780 /* Fix the kernel immediately if it seems the route 1781 * has gone bad, since there may be a working route that 1782 * aggregates this route. 1783 */ 1784 if (new->rts_metric == HOPCNT_INFINITY) { 1785 need_kern.tv_sec = now.tv_sec; 1786 if (new->rts_time >= now.tv_sec - EXPIRE_TIME) 1787 new->rts_time = now.tv_sec - EXPIRE_TIME; 1788 } 1789 rt->rt_seqno = update_seqno; 1790 set_need_flash(); 1791 } 1792 1793 if (rt->rt_gate != new->rts_gate) { 1794 need_kern.tv_sec = now.tv_sec; 1795 rt->rt_seqno = update_seqno; 1796 set_need_flash(); 1797 } 1798 1799 state |= (rt->rt_state & RS_SUBNET); 1800 1801 /* Keep various things from deciding ageless routes are stale. 1802 */ 1803 if (!AGE_RT(state, new->rts_ifp)) 1804 new->rts_time = now.tv_sec; 1805 1806 if (TRACEACTIONS) 1807 trace_change(rt, state, new, 1808 label ? label : "Chg "); 1809 1810 rt->rt_state = state; 1811 rt->rt_spares[0] = *new; 1812} 1813 1814 1815/* check for a better route among the spares 1816 */ 1817static struct rt_spare * 1818rts_better(struct rt_entry *rt) 1819{ 1820 struct rt_spare *rts, *rts1; 1821 int i; 1822 1823 /* find the best alternative among the spares */ 1824 rts = rt->rt_spares+1; 1825 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1826 if (BETTER_LINK(rt,rts1,rts)) 1827 rts = rts1; 1828 } 1829 1830 return rts; 1831} 1832 1833 1834/* switch to a backup route 1835 */ 1836void 1837rtswitch(struct rt_entry *rt, 1838 struct rt_spare *rts) 1839{ 1840 struct rt_spare swap; 1841 char label[20]; 1842 1843 /* Do not change permanent routes */ 1844 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1845 | RS_NET_SYN | RS_IF))) 1846 return; 1847 1848 /* find the best alternative among the spares */ 1849 if (rts == 0) 1850 rts = rts_better(rt); 1851 1852 /* Do not bother if it is not worthwhile. 1853 */ 1854 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1855 return; 1856 1857 swap = rt->rt_spares[0]; 1858 (void)snprintf(label, sizeof(label), "Use #%d", 1859 (int)(rts - rt->rt_spares)); 1860 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label); 1861 if (swap.rts_metric == HOPCNT_INFINITY) { 1862 *rts = rts_empty; 1863 } else { 1864 *rts = swap; 1865 } 1866} 1867 1868 1869void 1870rtdelete(struct rt_entry *rt) 1871{ 1872 struct khash *k; 1873 1874 1875 if (TRACEACTIONS) 1876 trace_add_del("Del", rt); 1877 1878 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1879 if (k != 0) { 1880 k->k_state |= KS_DELETE; 1881 need_kern.tv_sec = now.tv_sec; 1882 } 1883 1884 dst_sock.sin_addr.s_addr = rt->rt_dst; 1885 mask_sock.sin_addr.s_addr = htonl(rt->rt_mask); 1886 masktrim(&mask_sock); 1887 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1888 rhead)) { 1889 msglog("rnh_deladdr() failed"); 1890 } else { 1891 free(rt); 1892 total_routes--; 1893 } 1894} 1895 1896 1897void 1898rts_delete(struct rt_entry *rt, 1899 struct rt_spare *rts) 1900{ 1901 trace_upslot(rt, rts, &rts_empty); 1902 *rts = rts_empty; 1903} 1904 1905 1906/* Get rid of a bad route, and try to switch to a replacement. 1907 */ 1908void 1909rtbad(struct rt_entry *rt) 1910{ 1911 struct rt_spare new; 1912 1913 /* Poison the route */ 1914 new = rt->rt_spares[0]; 1915 new.rts_metric = HOPCNT_INFINITY; 1916 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0); 1917 rtswitch(rt, 0); 1918} 1919 1920 1921/* Junk a RS_NET_SYN or RS_LOCAL route, 1922 * unless it is needed by another interface. 1923 */ 1924void 1925rtbad_sub(struct rt_entry *rt) 1926{ 1927 struct interface *ifp, *ifp1; 1928 struct intnet *intnetp; 1929 u_int state; 1930 1931 1932 ifp1 = 0; 1933 state = 0; 1934 1935 if (rt->rt_state & RS_LOCAL) { 1936 /* Is this the route through loopback for the interface? 1937 * If so, see if it is used by any other interfaces, such 1938 * as a point-to-point interface with the same local address. 1939 */ 1940 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1941 /* Retain it if another interface needs it. 1942 */ 1943 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1944 state |= RS_LOCAL; 1945 ifp1 = ifp; 1946 break; 1947 } 1948 } 1949 1950 } 1951 1952 if (!(state & RS_LOCAL)) { 1953 /* Retain RIPv1 logical network route if there is another 1954 * interface that justifies it. 1955 */ 1956 if (rt->rt_state & RS_NET_SYN) { 1957 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1958 if ((ifp->int_state & IS_NEED_NET_SYN) 1959 && rt->rt_mask == ifp->int_std_mask 1960 && rt->rt_dst == ifp->int_std_addr) { 1961 state |= RS_NET_SYN; 1962 ifp1 = ifp; 1963 break; 1964 } 1965 } 1966 } 1967 1968 /* or if there is an authority route that needs it. */ 1969 for (intnetp = intnets; 1970 intnetp != 0; 1971 intnetp = intnetp->intnet_next) { 1972 if (intnetp->intnet_addr == rt->rt_dst 1973 && intnetp->intnet_mask == rt->rt_mask) { 1974 state |= (RS_NET_SYN | RS_NET_INT); 1975 break; 1976 } 1977 } 1978 } 1979 1980 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1981 struct rt_spare new = rt->rt_spares[0]; 1982 new.rts_ifp = ifp1; 1983 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state), 1984 &new, 0); 1985 } else { 1986 rtbad(rt); 1987 } 1988} 1989 1990 1991/* Called while walking the table looking for sick interfaces 1992 * or after a time change. 1993 */ 1994/* ARGSUSED */ 1995int 1996walk_bad(struct radix_node *rn, 1997 struct walkarg *argp UNUSED) 1998{ 1999#define RT ((struct rt_entry *)rn) 2000 struct rt_spare *rts; 2001 int i; 2002 2003 2004 /* fix any spare routes through the interface 2005 */ 2006 rts = RT->rt_spares; 2007 for (i = NUM_SPARES; i != 1; i--) { 2008 rts++; 2009 if (rts->rts_metric < HOPCNT_INFINITY 2010 && (rts->rts_ifp == 0 2011 || (rts->rts_ifp->int_state & IS_BROKE))) 2012 rts_delete(RT, rts); 2013 } 2014 2015 /* Deal with the main route 2016 */ 2017 /* finished if it has been handled before or if its interface is ok 2018 */ 2019 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 2020 return 0; 2021 2022 /* Bad routes for other than interfaces are easy. 2023 */ 2024 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 2025 rtbad(RT); 2026 return 0; 2027 } 2028 2029 rtbad_sub(RT); 2030 return 0; 2031#undef RT 2032} 2033 2034 2035/* Check the age of an individual route. 2036 */ 2037/* ARGSUSED */ 2038static int 2039walk_age(struct radix_node *rn, 2040 struct walkarg *argp UNUSED) 2041{ 2042#define RT ((struct rt_entry *)rn) 2043 struct interface *ifp; 2044 struct rt_spare *rts; 2045 int i; 2046 2047 2048 /* age all of the spare routes, including the primary route 2049 * currently in use 2050 */ 2051 rts = RT->rt_spares; 2052 for (i = NUM_SPARES; i != 0; i--, rts++) { 2053 2054 ifp = rts->rts_ifp; 2055 if (i == NUM_SPARES) { 2056 if (!AGE_RT(RT->rt_state, ifp)) { 2057 /* Keep various things from deciding ageless 2058 * routes are stale 2059 */ 2060 rts->rts_time = now.tv_sec; 2061 continue; 2062 } 2063 2064 /* forget RIP routes after RIP has been turned off. 2065 */ 2066 if (rip_sock < 0) { 2067 rtdelete(RT); 2068 return 0; 2069 } 2070 } 2071 2072 /* age failing routes 2073 */ 2074 if (age_bad_gate == rts->rts_gate 2075 && rts->rts_time >= now_stale) { 2076 rts->rts_time -= SUPPLY_INTERVAL; 2077 } 2078 2079 /* trash the spare routes when they go bad */ 2080 if (rts->rts_metric < HOPCNT_INFINITY 2081 && now_garbage > rts->rts_time 2082 && i != NUM_SPARES) 2083 rts_delete(RT, rts); 2084 } 2085 2086 2087 /* finished if the active route is still fresh */ 2088 if (now_stale <= RT->rt_time) 2089 return 0; 2090 2091 /* try to switch to an alternative */ 2092 rtswitch(RT, 0); 2093 2094 /* Delete a dead route after it has been publically mourned. */ 2095 if (now_garbage > RT->rt_time) { 2096 rtdelete(RT); 2097 return 0; 2098 } 2099 2100 /* Start poisoning a bad route before deleting it. */ 2101 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) { 2102 struct rt_spare new = RT->rt_spares[0]; 2103 new.rts_metric = HOPCNT_INFINITY; 2104 rtchange(RT, RT->rt_state, &new, 0); 2105 } 2106 return 0; 2107} 2108 2109 2110/* Watch for dead routes and interfaces. 2111 */ 2112void 2113age(naddr bad_gate) 2114{ 2115 struct interface *ifp; 2116 int need_query = 0; 2117 2118 /* If not listening to RIP, there is no need to age the routes in 2119 * the table. 2120 */ 2121 age_timer.tv_sec = (now.tv_sec 2122 + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); 2123 2124 /* Check for dead IS_REMOTE interfaces by timing their 2125 * transmissions. 2126 */ 2127 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 2128 if (!(ifp->int_state & IS_REMOTE)) 2129 continue; 2130 2131 /* ignore unreachable remote interfaces */ 2132 if (!check_remote(ifp)) 2133 continue; 2134 2135 /* Restore remote interface that has become reachable 2136 */ 2137 if (ifp->int_state & IS_BROKE) 2138 if_ok(ifp, "remote "); 2139 2140 if (ifp->int_act_time != NEVER 2141 && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { 2142 msglog("remote interface %s to %s timed out after" 2143 " %lld:%lld", 2144 ifp->int_name, 2145 naddr_ntoa(ifp->int_dstaddr), 2146 (long long)(now.tv_sec - ifp->int_act_time)/60, 2147 (long long)(now.tv_sec - ifp->int_act_time)%60); 2148 if_sick(ifp); 2149 } 2150 2151 /* If we have not heard from the other router 2152 * recently, ask it. 2153 */ 2154 if (now.tv_sec >= ifp->int_query_time) { 2155 ifp->int_query_time = NEVER; 2156 need_query = 1; 2157 } 2158 } 2159 2160 /* Age routes. */ 2161 age_bad_gate = bad_gate; 2162 (void)rn_walktree(rhead, walk_age, 0); 2163 2164 /* delete old redirected routes to keep the kernel table small 2165 * and prevent blackholes 2166 */ 2167 del_redirects(bad_gate, now.tv_sec-STALE_TIME); 2168 2169 /* Update the kernel routing table. */ 2170 fix_kern(); 2171 2172 /* poke reticent remote gateways */ 2173 if (need_query) 2174 rip_query(); 2175} 2176