1 /* 2 * Copyright (c) 1983, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgment: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: src/sbin/routed/table.c,v 1.9.2.2 2000/08/14 17:00:04 sheldonh Exp $ 34 * $DragonFly: src/sbin/routed/table.c,v 1.5 2004/12/18 21:43:40 swildner Exp $ 35 */ 36 37 #include "defs.h" 38 39 #if !defined(sgi) && !defined(__NetBSD__) 40 static char sccsid[] __attribute__((unused)) = "@(#)tables.c 8.1 (Berkeley) 6/5/93"; 41 #elif defined(__NetBSD__) 42 __RCSID("$NetBSD$"); 43 #endif 44 #ident "$FreeBSD: src/sbin/routed/table.c,v 1.9.2.2 2000/08/14 17:00:04 sheldonh Exp $" 45 46 static struct rt_spare *rts_better(struct rt_entry *); 47 static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0}; 48 static void set_need_flash(void); 49 #ifdef _HAVE_SIN_LEN 50 static void masktrim(struct sockaddr_in *ap); 51 #else 52 static void masktrim(struct sockaddr_in_new *ap); 53 #endif 54 55 56 struct radix_node_head *rhead; /* root of the radix tree */ 57 58 int need_flash = 1; /* flash update needed 59 * start =1 to suppress the 1st 60 */ 61 62 struct timeval age_timer; /* next check of old routes */ 63 struct timeval need_kern = { /* need to update kernel table */ 64 EPOCH+MIN_WAITTIME-1, 0 65 }; 66 67 int stopint; 68 69 int total_routes; 70 71 /* zap any old routes through this gateway */ 72 naddr age_bad_gate; 73 74 75 /* It is desirable to "aggregate" routes, to combine differing routes of 76 * the same metric and next hop into a common route with a smaller netmask 77 * or to suppress redundant routes, routes that add no information to 78 * routes with smaller netmasks. 79 * 80 * A route is redundant if and only if any and all routes with smaller 81 * but matching netmasks and nets are the same. Since routes are 82 * kept sorted in the radix tree, redundant routes always come second. 83 * 84 * There are two kinds of aggregations. First, two routes of the same bit 85 * mask and differing only in the least significant bit of the network 86 * number can be combined into a single route with a coarser mask. 87 * 88 * Second, a route can be suppressed in favor of another route with a more 89 * coarse mask provided no incompatible routes with intermediate masks 90 * are present. The second kind of aggregation involves suppressing routes. 91 * A route must not be suppressed if an incompatible route exists with 92 * an intermediate mask, since the suppressed route would be covered 93 * by the intermediate. 94 * 95 * This code relies on the radix tree walk encountering routes 96 * sorted first by address, with the smallest address first. 97 */ 98 99 struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest; 100 101 /* #define DEBUG_AG */ 102 #ifdef DEBUG_AG 103 #define CHECK_AG() {int acnt = 0; struct ag_info *cag; \ 104 for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \ 105 acnt++; \ 106 for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \ 107 acnt++; \ 108 if (acnt != NUM_AG_SLOTS) { \ 109 fflush(stderr); \ 110 abort(); \ 111 } \ 112 } 113 #else 114 #define CHECK_AG() 115 #endif 116 117 118 /* Output the contents of an aggregation table slot. 119 * This function must always be immediately followed with the deletion 120 * of the target slot. 121 */ 122 static void 123 ag_out(struct ag_info *ag, 124 void (*out)(struct ag_info *)) 125 { 126 struct ag_info *ag_cors; 127 naddr bit; 128 129 130 /* Forget it if this route should not be output for split-horizon. */ 131 if (ag->ag_state & AGS_SPLIT_HZ) 132 return; 133 134 /* If we output both the even and odd twins, then the immediate parent, 135 * if it is present, is redundant, unless the parent manages to 136 * aggregate into something coarser. 137 * On successive calls, this code detects the even and odd twins, 138 * and marks the parent. 139 * 140 * Note that the order in which the radix tree code emits routes 141 * ensures that the twins are seen before the parent is emitted. 142 */ 143 ag_cors = ag->ag_cors; 144 if (ag_cors != 0 145 && ag_cors->ag_mask == ag->ag_mask<<1 146 && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) { 147 ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h) 148 ? AGS_REDUN0 149 : AGS_REDUN1); 150 } 151 152 /* Skip it if this route is itself redundant. 153 * 154 * It is ok to change the contents of the slot here, since it is 155 * always deleted next. 156 */ 157 if (ag->ag_state & AGS_REDUN0) { 158 if (ag->ag_state & AGS_REDUN1) 159 return; /* quit if fully redundant */ 160 /* make it finer if it is half-redundant */ 161 bit = (-ag->ag_mask) >> 1; 162 ag->ag_dst_h |= bit; 163 ag->ag_mask |= bit; 164 165 } else if (ag->ag_state & AGS_REDUN1) { 166 /* make it finer if it is half-redundant */ 167 bit = (-ag->ag_mask) >> 1; 168 ag->ag_mask |= bit; 169 } 170 out(ag); 171 } 172 173 174 static void 175 ag_del(struct ag_info *ag) 176 { 177 CHECK_AG(); 178 179 if (ag->ag_cors == 0) 180 ag_corsest = ag->ag_fine; 181 else 182 ag->ag_cors->ag_fine = ag->ag_fine; 183 184 if (ag->ag_fine == 0) 185 ag_finest = ag->ag_cors; 186 else 187 ag->ag_fine->ag_cors = ag->ag_cors; 188 189 ag->ag_fine = ag_avail; 190 ag_avail = ag; 191 192 CHECK_AG(); 193 } 194 195 196 /* Flush routes waiting for aggregation. 197 * This must not suppress a route unless it is known that among all 198 * routes with coarser masks that match it, the one with the longest 199 * mask is appropriate. This is ensured by scanning the routes 200 * in lexical order, and with the most restrictive mask first 201 * among routes to the same destination. 202 */ 203 void 204 ag_flush(naddr lim_dst_h, /* flush routes to here */ 205 naddr lim_mask, /* matching this mask */ 206 void (*out)(struct ag_info *)) 207 { 208 struct ag_info *ag, *ag_cors; 209 naddr dst_h; 210 211 212 for (ag = ag_finest; 213 ag != 0 && ag->ag_mask >= lim_mask; 214 ag = ag_cors) { 215 ag_cors = ag->ag_cors; 216 217 /* work on only the specified routes */ 218 dst_h = ag->ag_dst_h; 219 if ((dst_h & lim_mask) != lim_dst_h) 220 continue; 221 222 if (!(ag->ag_state & AGS_SUPPRESS)) 223 ag_out(ag, out); 224 225 else for ( ; ; ag_cors = ag_cors->ag_cors) { 226 /* Look for a route that can suppress the 227 * current route */ 228 if (ag_cors == 0) { 229 /* failed, so output it and look for 230 * another route to work on 231 */ 232 ag_out(ag, out); 233 break; 234 } 235 236 if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) { 237 /* We found a route with a coarser mask that 238 * aggregates the current target. 239 * 240 * If it has a different next hop, it 241 * cannot replace the target, so output 242 * the target. 243 */ 244 if (ag->ag_gate != ag_cors->ag_gate 245 && !(ag->ag_state & AGS_FINE_GATE) 246 && !(ag_cors->ag_state & AGS_CORS_GATE)) { 247 ag_out(ag, out); 248 break; 249 } 250 251 /* If the coarse route has a good enough 252 * metric, it suppresses the target. 253 * If the suppressed target was redundant, 254 * then mark the suppressor redundant. 255 */ 256 if (ag_cors->ag_pref <= ag->ag_pref) { 257 if (ag_cors->ag_seqno > ag->ag_seqno) 258 ag_cors->ag_seqno = ag->ag_seqno; 259 if (AG_IS_REDUN(ag->ag_state) 260 && ag_cors->ag_mask==ag->ag_mask<<1) { 261 if (ag_cors->ag_dst_h == dst_h) 262 ag_cors->ag_state |= AGS_REDUN0; 263 else 264 ag_cors->ag_state |= AGS_REDUN1; 265 } 266 if (ag->ag_tag != ag_cors->ag_tag) 267 ag_cors->ag_tag = 0; 268 if (ag->ag_nhop != ag_cors->ag_nhop) 269 ag_cors->ag_nhop = 0; 270 break; 271 } 272 } 273 } 274 275 /* That route has either been output or suppressed */ 276 ag_cors = ag->ag_cors; 277 ag_del(ag); 278 } 279 280 CHECK_AG(); 281 } 282 283 284 /* Try to aggregate a route with previous routes. 285 */ 286 void 287 ag_check(naddr dst, 288 naddr mask, 289 naddr gate, 290 naddr nhop, 291 char metric, 292 char pref, 293 u_int seqno, 294 u_short tag, 295 u_short state, 296 void (*out)(struct ag_info *)) /* output using this */ 297 { 298 struct ag_info *ag, *nag, *ag_cors; 299 naddr xaddr; 300 int x; 301 302 dst = ntohl(dst); 303 304 /* Punt non-contiguous subnet masks. 305 * 306 * (X & -X) contains a single bit if and only if X is a power of 2. 307 * (X + (X & -X)) == 0 if and only if X is a power of 2. 308 */ 309 if ((mask & -mask) + mask != 0) { 310 struct ag_info nc_ag; 311 312 nc_ag.ag_dst_h = dst; 313 nc_ag.ag_mask = mask; 314 nc_ag.ag_gate = gate; 315 nc_ag.ag_nhop = nhop; 316 nc_ag.ag_metric = metric; 317 nc_ag.ag_pref = pref; 318 nc_ag.ag_tag = tag; 319 nc_ag.ag_state = state; 320 nc_ag.ag_seqno = seqno; 321 out(&nc_ag); 322 return; 323 } 324 325 /* Search for the right slot in the aggregation table. 326 */ 327 ag_cors = 0; 328 ag = ag_corsest; 329 while (ag != 0) { 330 if (ag->ag_mask >= mask) 331 break; 332 333 /* Suppress old routes (i.e. combine with compatible routes 334 * with coarser masks) as we look for the right slot in the 335 * aggregation table for the new route. 336 * A route to an address less than the current destination 337 * will not be affected by the current route or any route 338 * seen hereafter. That means it is safe to suppress it. 339 * This check keeps poor routes (e.g. with large hop counts) 340 * from preventing suppression of finer routes. 341 */ 342 if (ag_cors != 0 343 && ag->ag_dst_h < dst 344 && (ag->ag_state & AGS_SUPPRESS) 345 && ag_cors->ag_pref <= ag->ag_pref 346 && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h 347 && (ag_cors->ag_gate == ag->ag_gate 348 || (ag->ag_state & AGS_FINE_GATE) 349 || (ag_cors->ag_state & AGS_CORS_GATE))) { 350 if (ag_cors->ag_seqno > ag->ag_seqno) 351 ag_cors->ag_seqno = ag->ag_seqno; 352 /* If the suppressed target was redundant, 353 * then mark the suppressor redundant. 354 */ 355 if (AG_IS_REDUN(ag->ag_state) 356 && ag_cors->ag_mask == ag->ag_mask<<1) { 357 if (ag_cors->ag_dst_h == dst) 358 ag_cors->ag_state |= AGS_REDUN0; 359 else 360 ag_cors->ag_state |= AGS_REDUN1; 361 } 362 if (ag->ag_tag != ag_cors->ag_tag) 363 ag_cors->ag_tag = 0; 364 if (ag->ag_nhop != ag_cors->ag_nhop) 365 ag_cors->ag_nhop = 0; 366 ag_del(ag); 367 CHECK_AG(); 368 } else { 369 ag_cors = ag; 370 } 371 ag = ag_cors->ag_fine; 372 } 373 374 /* If we find the even/odd twin of the new route, and if the 375 * masks and so forth are equal, we can aggregate them. 376 * We can probably promote one of the pair. 377 * 378 * Since the routes are encountered in lexical order, 379 * the new route must be odd. However, the second or later 380 * times around this loop, it could be the even twin promoted 381 * from the even/odd pair of twins of the finer route. 382 */ 383 while (ag != 0 384 && ag->ag_mask == mask 385 && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) { 386 387 /* Here we know the target route and the route in the current 388 * slot have the same netmasks and differ by at most the 389 * last bit. They are either for the same destination, or 390 * for an even/odd pair of destinations. 391 */ 392 if (ag->ag_dst_h == dst) { 393 /* We have two routes to the same destination. 394 * Routes are encountered in lexical order, so a 395 * route is never promoted until the parent route is 396 * already present. So we know that the new route is 397 * a promoted (or aggregated) pair and the route 398 * already in the slot is the explicit route. 399 * 400 * Prefer the best route if their metrics differ, 401 * or the aggregated one if not, following a sort 402 * of longest-match rule. 403 */ 404 if (pref <= ag->ag_pref) { 405 ag->ag_gate = gate; 406 ag->ag_nhop = nhop; 407 ag->ag_tag = tag; 408 ag->ag_metric = metric; 409 ag->ag_pref = pref; 410 x = ag->ag_state; 411 ag->ag_state = state; 412 state = x; 413 } 414 415 /* The sequence number controls flash updating, 416 * and should be the smaller of the two. 417 */ 418 if (ag->ag_seqno > seqno) 419 ag->ag_seqno = seqno; 420 421 /* Some bits are set if they are set on either route, 422 * except when the route is for an interface. 423 */ 424 if (!(ag->ag_state & AGS_IF)) 425 ag->ag_state |= (state & (AGS_AGGREGATE_EITHER 426 | AGS_REDUN0 427 | AGS_REDUN1)); 428 return; 429 } 430 431 /* If one of the routes can be promoted and the other can 432 * be suppressed, it may be possible to combine them or 433 * worthwhile to promote one. 434 * 435 * Any route that can be promoted is always 436 * marked to be eligible to be suppressed. 437 */ 438 if (!((state & AGS_AGGREGATE) 439 && (ag->ag_state & AGS_SUPPRESS)) 440 && !((ag->ag_state & AGS_AGGREGATE) 441 && (state & AGS_SUPPRESS))) 442 break; 443 444 /* A pair of even/odd twin routes can be combined 445 * if either is redundant, or if they are via the 446 * same gateway and have the same metric. 447 */ 448 if (AG_IS_REDUN(ag->ag_state) 449 || AG_IS_REDUN(state) 450 || (ag->ag_gate == gate 451 && ag->ag_pref == pref 452 && (state & ag->ag_state & AGS_AGGREGATE) != 0)) { 453 454 /* We have both the even and odd pairs. 455 * Since the routes are encountered in order, 456 * the route in the slot must be the even twin. 457 * 458 * Combine and promote (aggregate) the pair of routes. 459 */ 460 if (seqno > ag->ag_seqno) 461 seqno = ag->ag_seqno; 462 if (!AG_IS_REDUN(state)) 463 state &= ~AGS_REDUN1; 464 if (AG_IS_REDUN(ag->ag_state)) 465 state |= AGS_REDUN0; 466 else 467 state &= ~AGS_REDUN0; 468 state |= (ag->ag_state & AGS_AGGREGATE_EITHER); 469 if (ag->ag_tag != tag) 470 tag = 0; 471 if (ag->ag_nhop != nhop) 472 nhop = 0; 473 474 /* Get rid of the even twin that was already 475 * in the slot. 476 */ 477 ag_del(ag); 478 479 } else if (ag->ag_pref >= pref 480 && (ag->ag_state & AGS_AGGREGATE)) { 481 /* If we cannot combine the pair, maybe the route 482 * with the worse metric can be promoted. 483 * 484 * Promote the old, even twin, by giving its slot 485 * in the table to the new, odd twin. 486 */ 487 ag->ag_dst_h = dst; 488 489 xaddr = ag->ag_gate; 490 ag->ag_gate = gate; 491 gate = xaddr; 492 493 xaddr = ag->ag_nhop; 494 ag->ag_nhop = nhop; 495 nhop = xaddr; 496 497 x = ag->ag_tag; 498 ag->ag_tag = tag; 499 tag = x; 500 501 /* The promoted route is even-redundant only if the 502 * even twin was fully redundant. It is not 503 * odd-redundant because the odd-twin will still be 504 * in the table. 505 */ 506 x = ag->ag_state; 507 if (!AG_IS_REDUN(x)) 508 x &= ~AGS_REDUN0; 509 x &= ~AGS_REDUN1; 510 ag->ag_state = state; 511 state = x; 512 513 x = ag->ag_metric; 514 ag->ag_metric = metric; 515 metric = x; 516 517 x = ag->ag_pref; 518 ag->ag_pref = pref; 519 pref = x; 520 521 /* take the newest sequence number */ 522 if (seqno >= ag->ag_seqno) 523 seqno = ag->ag_seqno; 524 else 525 ag->ag_seqno = seqno; 526 527 } else { 528 if (!(state & AGS_AGGREGATE)) 529 break; /* cannot promote either twin */ 530 531 /* Promote the new, odd twin by shaving its 532 * mask and address. 533 * The promoted route is odd-redundant only if the 534 * odd twin was fully redundant. It is not 535 * even-redundant because the even twin is still in 536 * the table. 537 */ 538 if (!AG_IS_REDUN(state)) 539 state &= ~AGS_REDUN1; 540 state &= ~AGS_REDUN0; 541 if (seqno > ag->ag_seqno) 542 seqno = ag->ag_seqno; 543 else 544 ag->ag_seqno = seqno; 545 } 546 547 mask <<= 1; 548 dst &= mask; 549 550 if (ag_cors == 0) { 551 ag = ag_corsest; 552 break; 553 } 554 ag = ag_cors; 555 ag_cors = ag->ag_cors; 556 } 557 558 /* When we can no longer promote and combine routes, 559 * flush the old route in the target slot. Also flush 560 * any finer routes that we know will never be aggregated by 561 * the new route. 562 * 563 * In case we moved toward coarser masks, 564 * get back where we belong 565 */ 566 if (ag != 0 567 && ag->ag_mask < mask) { 568 ag_cors = ag; 569 ag = ag->ag_fine; 570 } 571 572 /* Empty the target slot 573 */ 574 if (ag != 0 && ag->ag_mask == mask) { 575 ag_flush(ag->ag_dst_h, ag->ag_mask, out); 576 ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine; 577 } 578 579 #ifdef DEBUG_AG 580 fflush(stderr); 581 if (ag == 0 && ag_cors != ag_finest) 582 abort(); 583 if (ag_cors == 0 && ag != ag_corsest) 584 abort(); 585 if (ag != 0 && ag->ag_cors != ag_cors) 586 abort(); 587 if (ag_cors != 0 && ag_cors->ag_fine != ag) 588 abort(); 589 CHECK_AG(); 590 #endif 591 592 /* Save the new route on the end of the table. 593 */ 594 nag = ag_avail; 595 ag_avail = nag->ag_fine; 596 597 nag->ag_dst_h = dst; 598 nag->ag_mask = mask; 599 nag->ag_gate = gate; 600 nag->ag_nhop = nhop; 601 nag->ag_metric = metric; 602 nag->ag_pref = pref; 603 nag->ag_tag = tag; 604 nag->ag_state = state; 605 nag->ag_seqno = seqno; 606 607 nag->ag_fine = ag; 608 if (ag != 0) 609 ag->ag_cors = nag; 610 else 611 ag_finest = nag; 612 nag->ag_cors = ag_cors; 613 if (ag_cors == 0) 614 ag_corsest = nag; 615 else 616 ag_cors->ag_fine = nag; 617 CHECK_AG(); 618 } 619 620 621 #define NAME0_LEN 14 622 static const char * 623 rtm_type_name(u_char type) 624 { 625 static const char *rtm_types[] = { 626 "RTM_ADD", 627 "RTM_DELETE", 628 "RTM_CHANGE", 629 "RTM_GET", 630 "RTM_LOSING", 631 "RTM_REDIRECT", 632 "RTM_MISS", 633 "RTM_LOCK", 634 "RTM_OLDADD", 635 "RTM_OLDDEL", 636 "RTM_RESOLVE", 637 "RTM_NEWADDR", 638 "RTM_DELADDR", 639 "RTM_IFINFO", 640 "RTM_NEWMADDR", 641 "RTM_DELMADDR" 642 }; 643 #define NEW_RTM_PAT "RTM type %#x" 644 static char name0[sizeof(NEW_RTM_PAT)+2]; 645 646 647 if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) 648 || type == 0) { 649 snprintf(name0, sizeof(name0), NEW_RTM_PAT, type); 650 return name0; 651 } else { 652 return rtm_types[type-1]; 653 } 654 #undef NEW_RTM_PAT 655 } 656 657 658 /* Trim a mask in a sockaddr 659 * Produce a length of 0 for an address of 0. 660 * Otherwise produce the index of the first zero byte. 661 */ 662 void 663 #ifdef _HAVE_SIN_LEN 664 masktrim(struct sockaddr_in *ap) 665 #else 666 masktrim(struct sockaddr_in_new *ap) 667 #endif 668 { 669 char *cp; 670 671 if (ap->sin_addr.s_addr == 0) { 672 ap->sin_len = 0; 673 return; 674 } 675 cp = (char *)(&ap->sin_addr.s_addr+1); 676 while (*--cp == 0) 677 continue; 678 ap->sin_len = cp - (char*)ap + 1; 679 } 680 681 682 /* Tell the kernel to add, delete or change a route 683 */ 684 static void 685 rtioctl(int action, /* RTM_DELETE, etc */ 686 naddr dst, 687 naddr gate, 688 naddr mask, 689 int metric, 690 int flags) 691 { 692 struct { 693 struct rt_msghdr w_rtm; 694 struct sockaddr_in w_dst; 695 struct sockaddr_in w_gate; 696 #ifdef _HAVE_SA_LEN 697 struct sockaddr_in w_mask; 698 #else 699 struct sockaddr_in_new w_mask; 700 #endif 701 } w; 702 long cc; 703 # define PAT " %-10s %s metric=%d flags=%#x" 704 # define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags 705 706 again: 707 memset(&w, 0, sizeof(w)); 708 w.w_rtm.rtm_msglen = sizeof(w); 709 w.w_rtm.rtm_version = RTM_VERSION; 710 w.w_rtm.rtm_type = action; 711 w.w_rtm.rtm_flags = flags; 712 w.w_rtm.rtm_seq = ++rt_sock_seqno; 713 w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY; 714 if (metric != 0 || action == RTM_CHANGE) { 715 w.w_rtm.rtm_rmx.rmx_hopcount = metric; 716 w.w_rtm.rtm_inits |= RTV_HOPCOUNT; 717 } 718 w.w_dst.sin_family = AF_INET; 719 w.w_dst.sin_addr.s_addr = dst; 720 w.w_gate.sin_family = AF_INET; 721 w.w_gate.sin_addr.s_addr = gate; 722 #ifdef _HAVE_SA_LEN 723 w.w_dst.sin_len = sizeof(w.w_dst); 724 w.w_gate.sin_len = sizeof(w.w_gate); 725 #endif 726 if (mask == HOST_MASK) { 727 w.w_rtm.rtm_flags |= RTF_HOST; 728 w.w_rtm.rtm_msglen -= sizeof(w.w_mask); 729 } else { 730 w.w_rtm.rtm_addrs |= RTA_NETMASK; 731 w.w_mask.sin_addr.s_addr = htonl(mask); 732 #ifdef _HAVE_SA_LEN 733 masktrim(&w.w_mask); 734 if (w.w_mask.sin_len == 0) 735 w.w_mask.sin_len = sizeof(long); 736 w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len); 737 #endif 738 } 739 740 #ifndef NO_INSTALL 741 cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); 742 if (cc < 0) { 743 if (errno == ESRCH 744 && (action == RTM_CHANGE || action == RTM_DELETE)) { 745 trace_act("route disappeared before" PAT, ARGS); 746 if (action == RTM_CHANGE) { 747 action = RTM_ADD; 748 goto again; 749 } 750 return; 751 } 752 msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno)); 753 return; 754 } else if (cc != w.w_rtm.rtm_msglen) { 755 msglog("write(rt_sock) wrote %ld instead of %d for" PAT, 756 cc, w.w_rtm.rtm_msglen, ARGS); 757 return; 758 } 759 #endif 760 if (TRACEKERNEL) 761 trace_misc("write kernel" PAT, ARGS); 762 #undef PAT 763 #undef ARGS 764 } 765 766 767 #define KHASH_SIZE 71 /* should be prime */ 768 #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE] 769 static struct khash { 770 struct khash *k_next; 771 naddr k_dst; 772 naddr k_mask; 773 naddr k_gate; 774 short k_metric; 775 u_short k_state; 776 #define KS_NEW 0x001 777 #define KS_DELETE 0x002 /* need to delete the route */ 778 #define KS_ADD 0x004 /* add to the kernel */ 779 #define KS_CHANGE 0x008 /* tell kernel to change the route */ 780 #define KS_DEL_ADD 0x010 /* delete & add to change the kernel */ 781 #define KS_STATIC 0x020 /* Static flag in kernel */ 782 #define KS_GATEWAY 0x040 /* G flag in kernel */ 783 #define KS_DYNAMIC 0x080 /* result of redirect */ 784 #define KS_DELETED 0x100 /* already deleted from kernel */ 785 #define KS_CHECK 0x200 786 time_t k_keep; 787 #define K_KEEP_LIM 30 788 time_t k_redirect_time; /* when redirected route 1st seen */ 789 } *khash_bins[KHASH_SIZE]; 790 791 792 static struct khash* 793 kern_find(naddr dst, naddr mask, struct khash ***ppk) 794 { 795 struct khash *k, **pk; 796 797 for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) { 798 if (k->k_dst == dst && k->k_mask == mask) 799 break; 800 } 801 if (ppk != 0) 802 *ppk = pk; 803 return k; 804 } 805 806 807 static struct khash* 808 kern_add(naddr dst, naddr mask) 809 { 810 struct khash *k, **pk; 811 812 k = kern_find(dst, mask, &pk); 813 if (k != 0) 814 return k; 815 816 k = (struct khash *)rtmalloc(sizeof(*k), "kern_add"); 817 818 memset(k, 0, sizeof(*k)); 819 k->k_dst = dst; 820 k->k_mask = mask; 821 k->k_state = KS_NEW; 822 k->k_keep = now.tv_sec; 823 *pk = k; 824 825 return k; 826 } 827 828 829 /* If a kernel route has a non-zero metric, check that it is still in the 830 * daemon table, and not deleted by interfaces coming and going. 831 */ 832 static void 833 kern_check_static(struct khash *k, 834 struct interface *ifp) 835 { 836 struct rt_entry *rt; 837 struct rt_spare new; 838 839 if (k->k_metric == 0) 840 return; 841 842 memset(&new, 0, sizeof(new)); 843 new.rts_ifp = ifp; 844 new.rts_gate = k->k_gate; 845 new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr; 846 new.rts_metric = k->k_metric; 847 new.rts_time = now.tv_sec; 848 849 rt = rtget(k->k_dst, k->k_mask); 850 if (rt != 0) { 851 if (!(rt->rt_state & RS_STATIC)) 852 rtchange(rt, rt->rt_state | RS_STATIC, &new, 0); 853 } else { 854 rtadd(k->k_dst, k->k_mask, RS_STATIC, &new); 855 } 856 } 857 858 859 /* operate on a kernel entry 860 */ 861 static void 862 kern_ioctl(struct khash *k, 863 int action, /* RTM_DELETE, etc */ 864 int flags) 865 866 { 867 switch (action) { 868 case RTM_DELETE: 869 k->k_state &= ~KS_DYNAMIC; 870 if (k->k_state & KS_DELETED) 871 return; 872 k->k_state |= KS_DELETED; 873 break; 874 case RTM_ADD: 875 k->k_state &= ~KS_DELETED; 876 break; 877 case RTM_CHANGE: 878 if (k->k_state & KS_DELETED) { 879 action = RTM_ADD; 880 k->k_state &= ~KS_DELETED; 881 } 882 break; 883 } 884 885 rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags); 886 } 887 888 889 /* add a route the kernel told us 890 */ 891 static void 892 rtm_add(struct rt_msghdr *rtm, 893 struct rt_addrinfo *info, 894 time_t keep) 895 { 896 struct khash *k; 897 struct interface *ifp; 898 naddr mask; 899 900 901 if (rtm->rtm_flags & RTF_HOST) { 902 mask = HOST_MASK; 903 } else if (INFO_MASK(info) != 0) { 904 mask = ntohl(S_ADDR(INFO_MASK(info))); 905 } else { 906 msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type)); 907 return; 908 } 909 910 k = kern_add(S_ADDR(INFO_DST(info)), mask); 911 if (k->k_state & KS_NEW) 912 k->k_keep = now.tv_sec+keep; 913 if (INFO_GATE(info) == 0) { 914 trace_act("note %s without gateway", 915 rtm_type_name(rtm->rtm_type)); 916 k->k_metric = HOPCNT_INFINITY; 917 } else if (INFO_GATE(info)->sa_family != AF_INET) { 918 trace_act("note %s with gateway AF=%d", 919 rtm_type_name(rtm->rtm_type), 920 INFO_GATE(info)->sa_family); 921 k->k_metric = HOPCNT_INFINITY; 922 } else { 923 k->k_gate = S_ADDR(INFO_GATE(info)); 924 k->k_metric = rtm->rtm_rmx.rmx_hopcount; 925 if (k->k_metric < 0) 926 k->k_metric = 0; 927 else if (k->k_metric > HOPCNT_INFINITY-1) 928 k->k_metric = HOPCNT_INFINITY-1; 929 } 930 k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD 931 | KS_DELETED | KS_GATEWAY | KS_STATIC 932 | KS_NEW | KS_CHECK); 933 if (rtm->rtm_flags & RTF_GATEWAY) 934 k->k_state |= KS_GATEWAY; 935 if (rtm->rtm_flags & RTF_STATIC) 936 k->k_state |= KS_STATIC; 937 938 if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { 939 if (INFO_AUTHOR(info) != 0 940 && INFO_AUTHOR(info)->sa_family == AF_INET) 941 ifp = iflookup(S_ADDR(INFO_AUTHOR(info))); 942 else 943 ifp = 0; 944 if (supplier 945 && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) { 946 /* Routers are not supposed to listen to redirects, 947 * so delete it if it came via an unknown interface 948 * or the interface does not have special permission. 949 */ 950 k->k_state &= ~KS_DYNAMIC; 951 k->k_state |= KS_DELETE; 952 LIM_SEC(need_kern, 0); 953 trace_act("mark for deletion redirected %s --> %s" 954 " via %s", 955 addrname(k->k_dst, k->k_mask, 0), 956 naddr_ntoa(k->k_gate), 957 ifp ? ifp->int_name : "unknown interface"); 958 } else { 959 k->k_state |= KS_DYNAMIC; 960 k->k_redirect_time = now.tv_sec; 961 trace_act("accept redirected %s --> %s via %s", 962 addrname(k->k_dst, k->k_mask, 0), 963 naddr_ntoa(k->k_gate), 964 ifp ? ifp->int_name : "unknown interface"); 965 } 966 return; 967 } 968 969 /* If it is not a static route, quit until the next comparison 970 * between the kernel and daemon tables, when it will be deleted. 971 */ 972 if (!(k->k_state & KS_STATIC)) { 973 k->k_state |= KS_DELETE; 974 LIM_SEC(need_kern, k->k_keep); 975 return; 976 } 977 978 /* Put static routes with real metrics into the daemon table so 979 * they can be advertised. 980 * 981 * Find the interface toward the gateway. 982 */ 983 ifp = iflookup(k->k_gate); 984 if (ifp == 0) 985 msglog("static route %s --> %s impossibly lacks ifp", 986 addrname(S_ADDR(INFO_DST(info)), mask, 0), 987 naddr_ntoa(k->k_gate)); 988 989 kern_check_static(k, ifp); 990 } 991 992 993 /* deal with packet loss 994 */ 995 static void 996 rtm_lose(struct rt_msghdr *rtm, 997 struct rt_addrinfo *info) 998 { 999 if (INFO_GATE(info) == 0 1000 || INFO_GATE(info)->sa_family != AF_INET) { 1001 trace_act("ignore %s without gateway", 1002 rtm_type_name(rtm->rtm_type)); 1003 return; 1004 } 1005 1006 if (rdisc_ok) 1007 rdisc_age(S_ADDR(INFO_GATE(info))); 1008 age(S_ADDR(INFO_GATE(info))); 1009 } 1010 1011 1012 /* Make the gateway slot of an info structure point to something 1013 * useful. If it is not already useful, but it specifies an interface, 1014 * then fill in the sockaddr_in provided and point it there. 1015 */ 1016 static int 1017 get_info_gate(struct sockaddr **sap, 1018 struct sockaddr_in *sin) 1019 { 1020 struct sockaddr_dl *sdl = (struct sockaddr_dl *)*sap; 1021 struct interface *ifp; 1022 1023 if (sdl == 0) 1024 return 0; 1025 if ((sdl)->sdl_family == AF_INET) 1026 return 1; 1027 if ((sdl)->sdl_family != AF_LINK) 1028 return 0; 1029 1030 ifp = ifwithindex(sdl->sdl_index, 1); 1031 if (ifp == 0) 1032 return 0; 1033 1034 sin->sin_addr.s_addr = ifp->int_addr; 1035 #ifdef _HAVE_SA_LEN 1036 sin->sin_len = sizeof(*sin); 1037 #endif 1038 sin->sin_family = AF_INET; 1039 *sap = (struct sockaddr*)sin; 1040 1041 return 1; 1042 } 1043 1044 1045 /* Clean the kernel table by copying it to the daemon image. 1046 * Eventually the daemon will delete any extra routes. 1047 */ 1048 void 1049 flush_kern(void) 1050 { 1051 static char *sysctl_buf; 1052 static size_t sysctl_buf_size = 0; 1053 size_t needed; 1054 int mib[6]; 1055 char *next, *lim; 1056 struct rt_msghdr *rtm; 1057 struct sockaddr_in gate_sin; 1058 struct rt_addrinfo info; 1059 int i; 1060 struct khash *k; 1061 1062 1063 for (i = 0; i < KHASH_SIZE; i++) { 1064 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1065 k->k_state |= KS_CHECK; 1066 } 1067 } 1068 1069 mib[0] = CTL_NET; 1070 mib[1] = PF_ROUTE; 1071 mib[2] = 0; /* protocol */ 1072 mib[3] = 0; /* wildcard address family */ 1073 mib[4] = NET_RT_DUMP; 1074 mib[5] = 0; /* no flags */ 1075 for (;;) { 1076 if ((needed = sysctl_buf_size) != 0) { 1077 if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0) 1078 break; 1079 if (errno != ENOMEM && errno != EFAULT) 1080 BADERR(1,"flush_kern: sysctl(RT_DUMP)"); 1081 free(sysctl_buf); 1082 needed = 0; 1083 } 1084 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) 1085 BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate"); 1086 /* Kludge around the habit of some systems, such as 1087 * BSD/OS 3.1, to not admit how many routes are in the 1088 * kernel, or at least to be quite wrong. 1089 */ 1090 needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr)); 1091 sysctl_buf = rtmalloc(sysctl_buf_size = needed, 1092 "flush_kern sysctl(RT_DUMP)"); 1093 } 1094 1095 lim = sysctl_buf + needed; 1096 for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) { 1097 rtm = (struct rt_msghdr *)next; 1098 if (rtm->rtm_msglen == 0) { 1099 msglog("zero length kernel route at " 1100 " %#lx in buffer %#lx before %#lx", 1101 (u_long)rtm, (u_long)sysctl_buf, (u_long)lim); 1102 break; 1103 } 1104 1105 rt_xaddrs(&info, 1106 (struct sockaddr *)(rtm+1), 1107 (struct sockaddr *)(next + rtm->rtm_msglen), 1108 rtm->rtm_addrs); 1109 1110 if (INFO_DST(&info) == 0 1111 || INFO_DST(&info)->sa_family != AF_INET) 1112 continue; 1113 1114 /* ignore ARP table entries on systems with a merged route 1115 * and ARP table. 1116 */ 1117 if (rtm->rtm_flags & RTF_LLINFO) 1118 continue; 1119 1120 /* ignore multicast addresses 1121 */ 1122 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1123 continue; 1124 1125 if (!get_info_gate(&INFO_GATE(&info), &gate_sin)) 1126 continue; 1127 1128 /* Note static routes and interface routes, and also 1129 * preload the image of the kernel table so that 1130 * we can later clean it, as well as avoid making 1131 * unneeded changes. Keep the old kernel routes for a 1132 * few seconds to allow a RIP or router-discovery 1133 * response to be heard. 1134 */ 1135 rtm_add(rtm,&info,MIN_WAITTIME); 1136 } 1137 1138 for (i = 0; i < KHASH_SIZE; i++) { 1139 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1140 if (k->k_state & KS_CHECK) { 1141 msglog("%s --> %s disappeared from kernel", 1142 addrname(k->k_dst, k->k_mask, 0), 1143 naddr_ntoa(k->k_gate)); 1144 del_static(k->k_dst, k->k_mask, k->k_gate, 1); 1145 } 1146 } 1147 } 1148 } 1149 1150 1151 /* Listen to announcements from the kernel 1152 */ 1153 void 1154 read_rt(void) 1155 { 1156 long cc; 1157 struct interface *ifp; 1158 struct sockaddr_in gate_sin; 1159 naddr mask, gate; 1160 union { 1161 struct { 1162 struct rt_msghdr rtm; 1163 struct sockaddr addrs[RTAX_MAX]; 1164 } r; 1165 struct if_msghdr ifm; 1166 } m; 1167 char str[100], *strp; 1168 struct rt_addrinfo info; 1169 1170 1171 for (;;) { 1172 cc = read(rt_sock, &m, sizeof(m)); 1173 if (cc <= 0) { 1174 if (cc < 0 && errno != EWOULDBLOCK) 1175 LOGERR("read(rt_sock)"); 1176 return; 1177 } 1178 1179 if (m.r.rtm.rtm_version != RTM_VERSION) { 1180 msglog("bogus routing message version %d", 1181 m.r.rtm.rtm_version); 1182 continue; 1183 } 1184 1185 /* Ignore our own results. 1186 */ 1187 if (m.r.rtm.rtm_type <= RTM_CHANGE 1188 && m.r.rtm.rtm_pid == mypid) { 1189 static int complained = 0; 1190 if (!complained) { 1191 msglog("receiving our own change messages"); 1192 complained = 1; 1193 } 1194 continue; 1195 } 1196 1197 if (m.r.rtm.rtm_type == RTM_IFINFO 1198 || m.r.rtm.rtm_type == RTM_NEWADDR 1199 || m.r.rtm.rtm_type == RTM_DELADDR) { 1200 ifp = ifwithindex(m.ifm.ifm_index, 1201 m.r.rtm.rtm_type != RTM_DELADDR); 1202 if (ifp == 0) 1203 trace_act("note %s with flags %#x" 1204 " for unknown interface index #%d", 1205 rtm_type_name(m.r.rtm.rtm_type), 1206 m.ifm.ifm_flags, 1207 m.ifm.ifm_index); 1208 else 1209 trace_act("note %s with flags %#x for %s", 1210 rtm_type_name(m.r.rtm.rtm_type), 1211 m.ifm.ifm_flags, 1212 ifp->int_name); 1213 1214 /* After being informed of a change to an interface, 1215 * check them all now if the check would otherwise 1216 * be a long time from now, if the interface is 1217 * not known, or if the interface has been turned 1218 * off or on. 1219 */ 1220 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1221 || ifp == 0 1222 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1223 & IFF_UP) != 0) 1224 ifinit_timer.tv_sec = now.tv_sec; 1225 continue; 1226 } 1227 1228 strcpy(str, rtm_type_name(m.r.rtm.rtm_type)); 1229 strp = &str[strlen(str)]; 1230 if (m.r.rtm.rtm_type <= RTM_CHANGE) 1231 strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid); 1232 1233 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1234 m.r.rtm.rtm_addrs); 1235 1236 if (INFO_DST(&info) == 0) { 1237 trace_act("ignore %s without dst", str); 1238 continue; 1239 } 1240 1241 if (INFO_DST(&info)->sa_family != AF_INET) { 1242 trace_act("ignore %s for AF %d", str, 1243 INFO_DST(&info)->sa_family); 1244 continue; 1245 } 1246 1247 mask = ((INFO_MASK(&info) != 0) 1248 ? ntohl(S_ADDR(INFO_MASK(&info))) 1249 : (m.r.rtm.rtm_flags & RTF_HOST) 1250 ? HOST_MASK 1251 : std_mask(S_ADDR(INFO_DST(&info)))); 1252 1253 strp += sprintf(strp, ": %s", 1254 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1255 1256 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1257 trace_act("ignore multicast %s", str); 1258 continue; 1259 } 1260 1261 if (m.r.rtm.rtm_flags & RTF_LLINFO) { 1262 trace_act("ignore ARP %s", str); 1263 continue; 1264 } 1265 1266 if (get_info_gate(&INFO_GATE(&info), &gate_sin)) { 1267 gate = S_ADDR(INFO_GATE(&info)); 1268 strp += sprintf(strp, " --> %s", naddr_ntoa(gate)); 1269 } else { 1270 gate = 0; 1271 } 1272 1273 if (INFO_AUTHOR(&info) != 0) 1274 strp += sprintf(strp, " by authority of %s", 1275 saddr_ntoa(INFO_AUTHOR(&info))); 1276 1277 switch (m.r.rtm.rtm_type) { 1278 case RTM_ADD: 1279 case RTM_CHANGE: 1280 case RTM_REDIRECT: 1281 if (m.r.rtm.rtm_errno != 0) { 1282 trace_act("ignore %s with \"%s\" error", 1283 str, strerror(m.r.rtm.rtm_errno)); 1284 } else { 1285 trace_act("%s", str); 1286 rtm_add(&m.r.rtm,&info,0); 1287 } 1288 break; 1289 1290 case RTM_DELETE: 1291 if (m.r.rtm.rtm_errno != 0 1292 && m.r.rtm.rtm_errno != ESRCH) { 1293 trace_act("ignore %s with \"%s\" error", 1294 str, strerror(m.r.rtm.rtm_errno)); 1295 } else { 1296 trace_act("%s", str); 1297 del_static(S_ADDR(INFO_DST(&info)), mask, 1298 gate, 1); 1299 } 1300 break; 1301 1302 case RTM_LOSING: 1303 trace_act("%s", str); 1304 rtm_lose(&m.r.rtm,&info); 1305 break; 1306 1307 default: 1308 trace_act("ignore %s", str); 1309 break; 1310 } 1311 } 1312 } 1313 1314 1315 /* after aggregating, note routes that belong in the kernel 1316 */ 1317 static void 1318 kern_out(struct ag_info *ag) 1319 { 1320 struct khash *k; 1321 1322 1323 /* Do not install bad routes if they are not already present. 1324 * This includes routes that had RS_NET_SYN for interfaces that 1325 * recently died. 1326 */ 1327 if (ag->ag_metric == HOPCNT_INFINITY) { 1328 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1329 if (k == 0) 1330 return; 1331 } else { 1332 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1333 } 1334 1335 if (k->k_state & KS_NEW) { 1336 /* will need to add new entry to the kernel table */ 1337 k->k_state = KS_ADD; 1338 if (ag->ag_state & AGS_GATEWAY) 1339 k->k_state |= KS_GATEWAY; 1340 k->k_gate = ag->ag_gate; 1341 k->k_metric = ag->ag_metric; 1342 return; 1343 } 1344 1345 if (k->k_state & KS_STATIC) 1346 return; 1347 1348 /* modify existing kernel entry if necessary */ 1349 if (k->k_gate != ag->ag_gate 1350 || k->k_metric != ag->ag_metric) { 1351 /* Must delete bad interface routes etc. to change them. */ 1352 if (k->k_metric == HOPCNT_INFINITY) 1353 k->k_state |= KS_DEL_ADD; 1354 k->k_gate = ag->ag_gate; 1355 k->k_metric = ag->ag_metric; 1356 k->k_state |= KS_CHANGE; 1357 } 1358 1359 /* If the daemon thinks the route should exist, forget 1360 * about any redirections. 1361 * If the daemon thinks the route should exist, eventually 1362 * override manual intervention by the operator. 1363 */ 1364 if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) { 1365 k->k_state &= ~KS_DYNAMIC; 1366 k->k_state |= (KS_ADD | KS_DEL_ADD); 1367 } 1368 1369 if ((k->k_state & KS_GATEWAY) 1370 && !(ag->ag_state & AGS_GATEWAY)) { 1371 k->k_state &= ~KS_GATEWAY; 1372 k->k_state |= (KS_ADD | KS_DEL_ADD); 1373 } else if (!(k->k_state & KS_GATEWAY) 1374 && (ag->ag_state & AGS_GATEWAY)) { 1375 k->k_state |= KS_GATEWAY; 1376 k->k_state |= (KS_ADD | KS_DEL_ADD); 1377 } 1378 1379 /* Deleting-and-adding is necessary to change aspects of a route. 1380 * Just delete instead of deleting and then adding a bad route. 1381 * Otherwise, we want to keep the route in the kernel. 1382 */ 1383 if (k->k_metric == HOPCNT_INFINITY 1384 && (k->k_state & KS_DEL_ADD)) 1385 k->k_state |= KS_DELETE; 1386 else 1387 k->k_state &= ~KS_DELETE; 1388 #undef RT 1389 } 1390 1391 1392 /* ARGSUSED */ 1393 static int 1394 walk_kern(struct radix_node *rn, 1395 struct walkarg *argp UNUSED) 1396 { 1397 #define RT ((struct rt_entry *)rn) 1398 char metric, pref; 1399 u_int ags = 0; 1400 1401 1402 /* Do not install synthetic routes */ 1403 if (RT->rt_state & RS_NET_SYN) 1404 return 0; 1405 1406 if (!(RT->rt_state & RS_IF)) { 1407 /* This is an ordinary route, not for an interface. 1408 */ 1409 1410 /* aggregate, ordinary good routes without regard to 1411 * their metric 1412 */ 1413 pref = 1; 1414 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1415 1416 /* Do not install host routes directly to hosts, to avoid 1417 * interfering with ARP entries in the kernel table. 1418 */ 1419 if (RT_ISHOST(RT) 1420 && ntohl(RT->rt_dst) == RT->rt_gate) 1421 return 0; 1422 1423 } else { 1424 /* This is an interface route. 1425 * Do not install routes for "external" remote interfaces. 1426 */ 1427 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1428 return 0; 1429 1430 /* Interfaces should override received routes. 1431 */ 1432 pref = 0; 1433 ags |= (AGS_IF | AGS_CORS_GATE); 1434 1435 /* If it is not an interface, or an alias for an interface, 1436 * it must be a "gateway." 1437 * 1438 * If it is a "remote" interface, it is also a "gateway" to 1439 * the kernel if is not a alias. 1440 */ 1441 if (RT->rt_ifp == 0 1442 || (RT->rt_ifp->int_state & IS_REMOTE)) 1443 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1444 } 1445 1446 /* If RIP is off and IRDP is on, let the route to the discovered 1447 * route suppress any RIP routes. Eventually the RIP routes 1448 * will time-out and be deleted. This reaches the steady-state 1449 * quicker. 1450 */ 1451 if ((RT->rt_state & RS_RDISC) && rip_sock < 0) 1452 ags |= AGS_CORS_GATE; 1453 1454 metric = RT->rt_metric; 1455 if (metric == HOPCNT_INFINITY) { 1456 /* if the route is dead, so try hard to aggregate. */ 1457 pref = HOPCNT_INFINITY; 1458 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1459 ags &= ~(AGS_IF | AGS_CORS_GATE); 1460 } 1461 1462 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1463 metric,pref, 0, 0, ags, kern_out); 1464 return 0; 1465 #undef RT 1466 } 1467 1468 1469 /* Update the kernel table to match the daemon table. 1470 */ 1471 static void 1472 fix_kern(void) 1473 { 1474 int i; 1475 struct khash *k, **pk; 1476 1477 1478 need_kern = age_timer; 1479 1480 /* Walk daemon table, updating the copy of the kernel table. 1481 */ 1482 rn_walktree(rhead, walk_kern, 0); 1483 ag_flush(0,0,kern_out); 1484 1485 for (i = 0; i < KHASH_SIZE; i++) { 1486 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1487 /* Do not touch static routes */ 1488 if (k->k_state & KS_STATIC) { 1489 kern_check_static(k,0); 1490 pk = &k->k_next; 1491 continue; 1492 } 1493 1494 /* check hold on routes deleted by the operator */ 1495 if (k->k_keep > now.tv_sec) { 1496 /* ensure we check when the hold is over */ 1497 LIM_SEC(need_kern, k->k_keep); 1498 /* mark for the next cycle */ 1499 k->k_state |= KS_DELETE; 1500 pk = &k->k_next; 1501 continue; 1502 } 1503 1504 if ((k->k_state & KS_DELETE) 1505 && !(k->k_state & KS_DYNAMIC)) { 1506 kern_ioctl(k, RTM_DELETE, 0); 1507 *pk = k->k_next; 1508 free(k); 1509 continue; 1510 } 1511 1512 if (k->k_state & KS_DEL_ADD) 1513 kern_ioctl(k, RTM_DELETE, 0); 1514 1515 if (k->k_state & KS_ADD) { 1516 kern_ioctl(k, RTM_ADD, 1517 ((0 != (k->k_state & (KS_GATEWAY 1518 | KS_DYNAMIC))) 1519 ? RTF_GATEWAY : 0)); 1520 } else if (k->k_state & KS_CHANGE) { 1521 kern_ioctl(k, RTM_CHANGE, 1522 ((0 != (k->k_state & (KS_GATEWAY 1523 | KS_DYNAMIC))) 1524 ? RTF_GATEWAY : 0)); 1525 } 1526 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1527 1528 /* Mark this route to be deleted in the next cycle. 1529 * This deletes routes that disappear from the 1530 * daemon table, since the normal aging code 1531 * will clear the bit for routes that have not 1532 * disappeared from the daemon table. 1533 */ 1534 k->k_state |= KS_DELETE; 1535 pk = &k->k_next; 1536 } 1537 } 1538 } 1539 1540 1541 /* Delete a static route in the image of the kernel table. 1542 */ 1543 void 1544 del_static(naddr dst, 1545 naddr mask, 1546 naddr gate, 1547 int gone) 1548 { 1549 struct khash *k; 1550 struct rt_entry *rt; 1551 1552 /* Just mark it in the table to be deleted next time the kernel 1553 * table is updated. 1554 * If it has already been deleted, mark it as such, and set its 1555 * keep-timer so that it will not be deleted again for a while. 1556 * This lets the operator delete a route added by the daemon 1557 * and add a replacement. 1558 */ 1559 k = kern_find(dst, mask, 0); 1560 if (k != 0 && (gate == 0 || k->k_gate == gate)) { 1561 k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK); 1562 k->k_state |= KS_DELETE; 1563 if (gone) { 1564 k->k_state |= KS_DELETED; 1565 k->k_keep = now.tv_sec + K_KEEP_LIM; 1566 } 1567 } 1568 1569 rt = rtget(dst, mask); 1570 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1571 rtbad(rt); 1572 } 1573 1574 1575 /* Delete all routes generated from ICMP Redirects that use a given gateway, 1576 * as well as old redirected routes. 1577 */ 1578 void 1579 del_redirects(naddr bad_gate, 1580 time_t old) 1581 { 1582 int i; 1583 struct khash *k; 1584 1585 1586 for (i = 0; i < KHASH_SIZE; i++) { 1587 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1588 if (!(k->k_state & KS_DYNAMIC) 1589 || (k->k_state & KS_STATIC)) 1590 continue; 1591 1592 if (k->k_gate != bad_gate 1593 && k->k_redirect_time > old 1594 && !supplier) 1595 continue; 1596 1597 k->k_state |= KS_DELETE; 1598 k->k_state &= ~KS_DYNAMIC; 1599 need_kern.tv_sec = now.tv_sec; 1600 trace_act("mark redirected %s --> %s for deletion", 1601 addrname(k->k_dst, k->k_mask, 0), 1602 naddr_ntoa(k->k_gate)); 1603 } 1604 } 1605 } 1606 1607 1608 /* Start the daemon tables. 1609 */ 1610 extern int max_keylen; 1611 1612 void 1613 rtinit(void) 1614 { 1615 int i; 1616 struct ag_info *ag; 1617 1618 /* Initialize the radix trees */ 1619 max_keylen = sizeof(struct sockaddr_in); 1620 rn_init(); 1621 rn_inithead(&rhead, 32); 1622 1623 /* mark all of the slots in the table free */ 1624 ag_avail = ag_slots; 1625 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1626 ag->ag_fine = ag+1; 1627 ag++; 1628 } 1629 } 1630 1631 1632 #ifdef _HAVE_SIN_LEN 1633 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}}; 1634 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}}; 1635 #else 1636 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1637 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1638 #endif 1639 1640 1641 static void 1642 set_need_flash(void) 1643 { 1644 if (!need_flash) { 1645 need_flash = 1; 1646 /* Do not send the flash update immediately. Wait a little 1647 * while to hear from other routers. 1648 */ 1649 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1650 } 1651 } 1652 1653 1654 /* Get a particular routing table entry 1655 */ 1656 struct rt_entry * 1657 rtget(naddr dst, naddr mask) 1658 { 1659 struct rt_entry *rt; 1660 1661 dst_sock.sin_addr.s_addr = dst; 1662 mask_sock.sin_addr.s_addr = htonl(mask); 1663 masktrim(&mask_sock); 1664 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1665 if (!rt 1666 || rt->rt_dst != dst 1667 || rt->rt_mask != mask) 1668 return 0; 1669 1670 return rt; 1671 } 1672 1673 1674 /* Find a route to dst as the kernel would. 1675 */ 1676 struct rt_entry * 1677 rtfind(naddr dst) 1678 { 1679 dst_sock.sin_addr.s_addr = dst; 1680 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1681 } 1682 1683 1684 /* add a route to the table 1685 */ 1686 void 1687 rtadd(naddr dst, 1688 naddr mask, 1689 u_int state, /* rt_state for the entry */ 1690 struct rt_spare *new) 1691 { 1692 struct rt_entry *rt; 1693 naddr smask; 1694 int i; 1695 struct rt_spare *rts; 1696 1697 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1698 memset(rt, 0, sizeof(*rt)); 1699 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1700 rts->rts_metric = HOPCNT_INFINITY; 1701 1702 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1703 rt->rt_dst = dst; 1704 rt->rt_dst_sock.sin_family = AF_INET; 1705 #ifdef _HAVE_SIN_LEN 1706 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1707 #endif 1708 if (mask != HOST_MASK) { 1709 smask = std_mask(dst); 1710 if ((smask & ~mask) == 0 && mask > smask) 1711 state |= RS_SUBNET; 1712 } 1713 mask_sock.sin_addr.s_addr = htonl(mask); 1714 masktrim(&mask_sock); 1715 rt->rt_mask = mask; 1716 rt->rt_state = state; 1717 rt->rt_spares[0] = *new; 1718 rt->rt_time = now.tv_sec; 1719 rt->rt_poison_metric = HOPCNT_INFINITY; 1720 rt->rt_seqno = update_seqno; 1721 1722 if (++total_routes == MAX_ROUTES) 1723 msglog("have maximum (%d) routes", total_routes); 1724 if (TRACEACTIONS) 1725 trace_add_del("Add", rt); 1726 1727 need_kern.tv_sec = now.tv_sec; 1728 set_need_flash(); 1729 1730 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1731 rhead, rt->rt_nodes)) { 1732 msglog("rnh_addaddr() failed for %s mask=%#lx", 1733 naddr_ntoa(dst), (u_long)mask); 1734 free(rt); 1735 } 1736 } 1737 1738 1739 /* notice a changed route 1740 */ 1741 void 1742 rtchange(struct rt_entry *rt, 1743 u_int state, /* new state bits */ 1744 struct rt_spare *new, 1745 char *label) 1746 { 1747 if (rt->rt_metric != new->rts_metric) { 1748 /* Fix the kernel immediately if it seems the route 1749 * has gone bad, since there may be a working route that 1750 * aggregates this route. 1751 */ 1752 if (new->rts_metric == HOPCNT_INFINITY) { 1753 need_kern.tv_sec = now.tv_sec; 1754 if (new->rts_time >= now.tv_sec - EXPIRE_TIME) 1755 new->rts_time = now.tv_sec - EXPIRE_TIME; 1756 } 1757 rt->rt_seqno = update_seqno; 1758 set_need_flash(); 1759 } 1760 1761 if (rt->rt_gate != new->rts_gate) { 1762 need_kern.tv_sec = now.tv_sec; 1763 rt->rt_seqno = update_seqno; 1764 set_need_flash(); 1765 } 1766 1767 state |= (rt->rt_state & RS_SUBNET); 1768 1769 /* Keep various things from deciding ageless routes are stale. 1770 */ 1771 if (!AGE_RT(state, new->rts_ifp)) 1772 new->rts_time = now.tv_sec; 1773 1774 if (TRACEACTIONS) 1775 trace_change(rt, state, new, 1776 label ? label : "Chg "); 1777 1778 rt->rt_state = state; 1779 rt->rt_spares[0] = *new; 1780 } 1781 1782 1783 /* check for a better route among the spares 1784 */ 1785 static struct rt_spare * 1786 rts_better(struct rt_entry *rt) 1787 { 1788 struct rt_spare *rts, *rts1; 1789 int i; 1790 1791 /* find the best alternative among the spares */ 1792 rts = rt->rt_spares+1; 1793 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1794 if (BETTER_LINK(rt,rts1,rts)) 1795 rts = rts1; 1796 } 1797 1798 return rts; 1799 } 1800 1801 1802 /* switch to a backup route 1803 */ 1804 void 1805 rtswitch(struct rt_entry *rt, 1806 struct rt_spare *rts) 1807 { 1808 struct rt_spare swap; 1809 char label[10]; 1810 1811 1812 /* Do not change permanent routes */ 1813 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1814 | RS_NET_SYN | RS_IF))) 1815 return; 1816 1817 /* find the best alternative among the spares */ 1818 if (rts == 0) 1819 rts = rts_better(rt); 1820 1821 /* Do not bother if it is not worthwhile. 1822 */ 1823 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1824 return; 1825 1826 swap = rt->rt_spares[0]; 1827 sprintf(label, "Use #%d", (int)(rts - rt->rt_spares)); 1828 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label); 1829 if (swap.rts_metric == HOPCNT_INFINITY) { 1830 *rts = rts_empty; 1831 } else { 1832 *rts = swap; 1833 } 1834 } 1835 1836 1837 void 1838 rtdelete(struct rt_entry *rt) 1839 { 1840 struct khash *k; 1841 1842 1843 if (TRACEACTIONS) 1844 trace_add_del("Del", rt); 1845 1846 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1847 if (k != 0) { 1848 k->k_state |= KS_DELETE; 1849 need_kern.tv_sec = now.tv_sec; 1850 } 1851 1852 dst_sock.sin_addr.s_addr = rt->rt_dst; 1853 mask_sock.sin_addr.s_addr = htonl(rt->rt_mask); 1854 masktrim(&mask_sock); 1855 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1856 rhead)) { 1857 msglog("rnh_deladdr() failed"); 1858 } else { 1859 free(rt); 1860 total_routes--; 1861 } 1862 } 1863 1864 1865 void 1866 rts_delete(struct rt_entry *rt, 1867 struct rt_spare *rts) 1868 { 1869 trace_upslot(rt, rts, &rts_empty); 1870 *rts = rts_empty; 1871 } 1872 1873 1874 /* Get rid of a bad route, and try to switch to a replacement. 1875 */ 1876 void 1877 rtbad(struct rt_entry *rt) 1878 { 1879 struct rt_spare new; 1880 1881 /* Poison the route */ 1882 new = rt->rt_spares[0]; 1883 new.rts_metric = HOPCNT_INFINITY; 1884 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0); 1885 rtswitch(rt, 0); 1886 } 1887 1888 1889 /* Junk a RS_NET_SYN or RS_LOCAL route, 1890 * unless it is needed by another interface. 1891 */ 1892 void 1893 rtbad_sub(struct rt_entry *rt) 1894 { 1895 struct interface *ifp, *ifp1; 1896 struct intnet *intnetp; 1897 u_int state; 1898 1899 1900 ifp1 = 0; 1901 state = 0; 1902 1903 if (rt->rt_state & RS_LOCAL) { 1904 /* Is this the route through loopback for the interface? 1905 * If so, see if it is used by any other interfaces, such 1906 * as a point-to-point interface with the same local address. 1907 */ 1908 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1909 /* Retain it if another interface needs it. 1910 */ 1911 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1912 state |= RS_LOCAL; 1913 ifp1 = ifp; 1914 break; 1915 } 1916 } 1917 1918 } 1919 1920 if (!(state & RS_LOCAL)) { 1921 /* Retain RIPv1 logical network route if there is another 1922 * interface that justifies it. 1923 */ 1924 if (rt->rt_state & RS_NET_SYN) { 1925 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1926 if ((ifp->int_state & IS_NEED_NET_SYN) 1927 && rt->rt_mask == ifp->int_std_mask 1928 && rt->rt_dst == ifp->int_std_addr) { 1929 state |= RS_NET_SYN; 1930 ifp1 = ifp; 1931 break; 1932 } 1933 } 1934 } 1935 1936 /* or if there is an authority route that needs it. */ 1937 for (intnetp = intnets; 1938 intnetp != 0; 1939 intnetp = intnetp->intnet_next) { 1940 if (intnetp->intnet_addr == rt->rt_dst 1941 && intnetp->intnet_mask == rt->rt_mask) { 1942 state |= (RS_NET_SYN | RS_NET_INT); 1943 break; 1944 } 1945 } 1946 } 1947 1948 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1949 struct rt_spare new = rt->rt_spares[0]; 1950 new.rts_ifp = ifp1; 1951 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state), 1952 &new, 0); 1953 } else { 1954 rtbad(rt); 1955 } 1956 } 1957 1958 1959 /* Called while walking the table looking for sick interfaces 1960 * or after a time change. 1961 */ 1962 /* ARGSUSED */ 1963 int 1964 walk_bad(struct radix_node *rn, 1965 struct walkarg *argp UNUSED) 1966 { 1967 #define RT ((struct rt_entry *)rn) 1968 struct rt_spare *rts; 1969 int i; 1970 1971 1972 /* fix any spare routes through the interface 1973 */ 1974 rts = RT->rt_spares; 1975 for (i = NUM_SPARES; i != 1; i--) { 1976 rts++; 1977 if (rts->rts_metric < HOPCNT_INFINITY 1978 && (rts->rts_ifp == 0 1979 || (rts->rts_ifp->int_state & IS_BROKE))) 1980 rts_delete(RT, rts); 1981 } 1982 1983 /* Deal with the main route 1984 */ 1985 /* finished if it has been handled before or if its interface is ok 1986 */ 1987 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 1988 return 0; 1989 1990 /* Bad routes for other than interfaces are easy. 1991 */ 1992 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 1993 rtbad(RT); 1994 return 0; 1995 } 1996 1997 rtbad_sub(RT); 1998 return 0; 1999 #undef RT 2000 } 2001 2002 2003 /* Check the age of an individual route. 2004 */ 2005 /* ARGSUSED */ 2006 static int 2007 walk_age(struct radix_node *rn, 2008 struct walkarg *argp UNUSED) 2009 { 2010 #define RT ((struct rt_entry *)rn) 2011 struct interface *ifp; 2012 struct rt_spare *rts; 2013 int i; 2014 2015 2016 /* age all of the spare routes, including the primary route 2017 * currently in use 2018 */ 2019 rts = RT->rt_spares; 2020 for (i = NUM_SPARES; i != 0; i--, rts++) { 2021 2022 ifp = rts->rts_ifp; 2023 if (i == NUM_SPARES) { 2024 if (!AGE_RT(RT->rt_state, ifp)) { 2025 /* Keep various things from deciding ageless 2026 * routes are stale 2027 */ 2028 rts->rts_time = now.tv_sec; 2029 continue; 2030 } 2031 2032 /* forget RIP routes after RIP has been turned off. 2033 */ 2034 if (rip_sock < 0) { 2035 rtdelete(RT); 2036 return 0; 2037 } 2038 } 2039 2040 /* age failing routes 2041 */ 2042 if (age_bad_gate == rts->rts_gate 2043 && rts->rts_time >= now_stale) { 2044 rts->rts_time -= SUPPLY_INTERVAL; 2045 } 2046 2047 /* trash the spare routes when they go bad */ 2048 if (rts->rts_metric < HOPCNT_INFINITY 2049 && now_garbage > rts->rts_time 2050 && i != NUM_SPARES) 2051 rts_delete(RT, rts); 2052 } 2053 2054 2055 /* finished if the active route is still fresh */ 2056 if (now_stale <= RT->rt_time) 2057 return 0; 2058 2059 /* try to switch to an alternative */ 2060 rtswitch(RT, 0); 2061 2062 /* Delete a dead route after it has been publically mourned. */ 2063 if (now_garbage > RT->rt_time) { 2064 rtdelete(RT); 2065 return 0; 2066 } 2067 2068 /* Start poisoning a bad route before deleting it. */ 2069 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) { 2070 struct rt_spare new = RT->rt_spares[0]; 2071 new.rts_metric = HOPCNT_INFINITY; 2072 rtchange(RT, RT->rt_state, &new, 0); 2073 } 2074 return 0; 2075 } 2076 2077 2078 /* Watch for dead routes and interfaces. 2079 */ 2080 void 2081 age(naddr bad_gate) 2082 { 2083 struct interface *ifp; 2084 int need_query = 0; 2085 2086 /* If not listening to RIP, there is no need to age the routes in 2087 * the table. 2088 */ 2089 age_timer.tv_sec = (now.tv_sec 2090 + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); 2091 2092 /* Check for dead IS_REMOTE interfaces by timing their 2093 * transmissions. 2094 */ 2095 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 2096 if (!(ifp->int_state & IS_REMOTE)) 2097 continue; 2098 2099 /* ignore unreachable remote interfaces */ 2100 if (!check_remote(ifp)) 2101 continue; 2102 2103 /* Restore remote interface that has become reachable 2104 */ 2105 if (ifp->int_state & IS_BROKE) 2106 if_ok(ifp, "remote "); 2107 2108 if (ifp->int_act_time != NEVER 2109 && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { 2110 msglog("remote interface %s to %s timed out after" 2111 " %ld:%ld", 2112 ifp->int_name, 2113 naddr_ntoa(ifp->int_dstaddr), 2114 (now.tv_sec - ifp->int_act_time)/60, 2115 (now.tv_sec - ifp->int_act_time)%60); 2116 if_sick(ifp); 2117 } 2118 2119 /* If we have not heard from the other router 2120 * recently, ask it. 2121 */ 2122 if (now.tv_sec >= ifp->int_query_time) { 2123 ifp->int_query_time = NEVER; 2124 need_query = 1; 2125 } 2126 } 2127 2128 /* Age routes. */ 2129 age_bad_gate = bad_gate; 2130 rn_walktree(rhead, walk_age, 0); 2131 2132 /* delete old redirected routes to keep the kernel table small 2133 * and prevent blackholes 2134 */ 2135 del_redirects(bad_gate, now.tv_sec-STALE_TIME); 2136 2137 /* Update the kernel routing table. */ 2138 fix_kern(); 2139 2140 /* poke reticent remote gateways */ 2141 if (need_query) 2142 rip_query(); 2143 } 2144