1 /* $NetBSD: table.c,v 1.17 2002/12/06 02:18:38 thorpej 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 1.17 2002/12/06 02:18:38 thorpej Exp $"); 40 #elif defined(__FreeBSD__) 41 __RCSID("$FreeBSD$"); 42 #else 43 __RCSID("Revision: 2.27 "); 44 #ident "Revision: 2.27 " 45 #endif 46 47 static struct rt_spare *rts_better(struct rt_entry *); 48 static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0}; 49 static void set_need_flash(void); 50 #ifdef _HAVE_SIN_LEN 51 static void masktrim(struct sockaddr_in *ap); 52 #else 53 static void masktrim(struct sockaddr_in_new *ap); 54 #endif 55 56 57 struct radix_node_head *rhead; /* root of the radix tree */ 58 59 int need_flash = 1; /* flash update needed 60 * start =1 to suppress the 1st 61 */ 62 63 struct timeval age_timer; /* next check of old routes */ 64 struct timeval need_kern = { /* need to update kernel table */ 65 EPOCH+MIN_WAITTIME-1, 0 66 }; 67 68 int stopint; 69 70 int total_routes; 71 72 /* zap any old routes through this gateway */ 73 naddr age_bad_gate; 74 75 76 /* It is desirable to "aggregate" routes, to combine differing routes of 77 * the same metric and next hop into a common route with a smaller netmask 78 * or to suppress redundant routes, routes that add no information to 79 * routes with smaller netmasks. 80 * 81 * A route is redundant if and only if any and all routes with smaller 82 * but matching netmasks and nets are the same. Since routes are 83 * kept sorted in the radix tree, redundant routes always come second. 84 * 85 * There are two kinds of aggregations. First, two routes of the same bit 86 * mask and differing only in the least significant bit of the network 87 * number can be combined into a single route with a coarser mask. 88 * 89 * Second, a route can be suppressed in favor of another route with a more 90 * coarse mask provided no incompatible routes with intermediate masks 91 * are present. The second kind of aggregation involves suppressing routes. 92 * A route must not be suppressed if an incompatible route exists with 93 * an intermediate mask, since the suppressed route would be covered 94 * by the intermediate. 95 * 96 * This code relies on the radix tree walk encountering routes 97 * sorted first by address, with the smallest address first. 98 */ 99 100 struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest; 101 102 /* #define DEBUG_AG */ 103 #ifdef DEBUG_AG 104 #define CHECK_AG() {int acnt = 0; struct ag_info *cag; \ 105 for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \ 106 acnt++; \ 107 for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \ 108 acnt++; \ 109 if (acnt != NUM_AG_SLOTS) { \ 110 (void)fflush(stderr); \ 111 abort(); \ 112 } \ 113 } 114 #else 115 #define CHECK_AG() 116 #endif 117 118 119 /* Output the contents of an aggregation table slot. 120 * This function must always be immediately followed with the deletion 121 * of the target slot. 122 */ 123 static void 124 ag_out(struct ag_info *ag, 125 void (*out)(struct ag_info *)) 126 { 127 struct ag_info *ag_cors; 128 naddr bit; 129 130 131 /* Forget it if this route should not be output for split-horizon. */ 132 if (ag->ag_state & AGS_SPLIT_HZ) 133 return; 134 135 /* If we output both the even and odd twins, then the immediate parent, 136 * if it is present, is redundant, unless the parent manages to 137 * aggregate into something coarser. 138 * On successive calls, this code detects the even and odd twins, 139 * and marks the parent. 140 * 141 * Note that the order in which the radix tree code emits routes 142 * ensures that the twins are seen before the parent is emitted. 143 */ 144 ag_cors = ag->ag_cors; 145 if (ag_cors != 0 146 && ag_cors->ag_mask == ag->ag_mask<<1 147 && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) { 148 ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h) 149 ? AGS_REDUN0 150 : AGS_REDUN1); 151 } 152 153 /* Skip it if this route is itself redundant. 154 * 155 * It is ok to change the contents of the slot here, since it is 156 * always deleted next. 157 */ 158 if (ag->ag_state & AGS_REDUN0) { 159 if (ag->ag_state & AGS_REDUN1) 160 return; /* quit if fully redundant */ 161 /* make it finer if it is half-redundant */ 162 bit = (-ag->ag_mask) >> 1; 163 ag->ag_dst_h |= bit; 164 ag->ag_mask |= bit; 165 166 } else if (ag->ag_state & AGS_REDUN1) { 167 /* make it finer if it is half-redundant */ 168 bit = (-ag->ag_mask) >> 1; 169 ag->ag_mask |= bit; 170 } 171 out(ag); 172 } 173 174 175 static void 176 ag_del(struct ag_info *ag) 177 { 178 CHECK_AG(); 179 180 if (ag->ag_cors == 0) 181 ag_corsest = ag->ag_fine; 182 else 183 ag->ag_cors->ag_fine = ag->ag_fine; 184 185 if (ag->ag_fine == 0) 186 ag_finest = ag->ag_cors; 187 else 188 ag->ag_fine->ag_cors = ag->ag_cors; 189 190 ag->ag_fine = ag_avail; 191 ag_avail = ag; 192 193 CHECK_AG(); 194 } 195 196 197 /* Flush routes waiting for aggregation. 198 * This must not suppress a route unless it is known that among all 199 * routes with coarser masks that match it, the one with the longest 200 * mask is appropriate. This is ensured by scanning the routes 201 * in lexical order, and with the most restrictive mask first 202 * among routes to the same destination. 203 */ 204 void 205 ag_flush(naddr lim_dst_h, /* flush routes to here */ 206 naddr lim_mask, /* matching this mask */ 207 void (*out)(struct ag_info *)) 208 { 209 struct ag_info *ag, *ag_cors; 210 naddr dst_h; 211 212 213 for (ag = ag_finest; 214 ag != 0 && ag->ag_mask >= lim_mask; 215 ag = ag_cors) { 216 ag_cors = ag->ag_cors; 217 218 /* work on only the specified routes */ 219 dst_h = ag->ag_dst_h; 220 if ((dst_h & lim_mask) != lim_dst_h) 221 continue; 222 223 if (!(ag->ag_state & AGS_SUPPRESS)) 224 ag_out(ag, out); 225 226 else for ( ; ; ag_cors = ag_cors->ag_cors) { 227 /* Look for a route that can suppress the 228 * current route */ 229 if (ag_cors == 0) { 230 /* failed, so output it and look for 231 * another route to work on 232 */ 233 ag_out(ag, out); 234 break; 235 } 236 237 if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) { 238 /* We found a route with a coarser mask that 239 * aggregates the current target. 240 * 241 * If it has a different next hop, it 242 * cannot replace the target, so output 243 * the target. 244 */ 245 if (ag->ag_gate != ag_cors->ag_gate 246 && !(ag->ag_state & AGS_FINE_GATE) 247 && !(ag_cors->ag_state & AGS_CORS_GATE)) { 248 ag_out(ag, out); 249 break; 250 } 251 252 /* If the coarse route has a good enough 253 * metric, it suppresses the target. 254 * If the suppressed target was redundant, 255 * then mark the suppressor redundant. 256 */ 257 if (ag_cors->ag_pref <= ag->ag_pref) { 258 if (AG_IS_REDUN(ag->ag_state) 259 && ag_cors->ag_mask==ag->ag_mask<<1) { 260 if (ag_cors->ag_dst_h == dst_h) 261 ag_cors->ag_state |= AGS_REDUN0; 262 else 263 ag_cors->ag_state |= AGS_REDUN1; 264 } 265 if (ag->ag_tag != ag_cors->ag_tag) 266 ag_cors->ag_tag = 0; 267 if (ag->ag_nhop != ag_cors->ag_nhop) 268 ag_cors->ag_nhop = 0; 269 break; 270 } 271 } 272 } 273 274 /* That route has either been output or suppressed */ 275 ag_cors = ag->ag_cors; 276 ag_del(ag); 277 } 278 279 CHECK_AG(); 280 } 281 282 283 /* Try to aggregate a route with previous routes. 284 */ 285 void 286 ag_check(naddr dst, 287 naddr mask, 288 naddr gate, 289 naddr nhop, 290 char metric, 291 char pref, 292 u_int new_seqno, 293 u_short tag, 294 u_short state, 295 void (*out)(struct ag_info *)) /* output using this */ 296 { 297 struct ag_info *ag, *nag, *ag_cors; 298 naddr xaddr; 299 int x; 300 301 NTOHL(dst); 302 303 /* Punt non-contiguous subnet masks. 304 * 305 * (X & -X) contains a single bit if and only if X is a power of 2. 306 * (X + (X & -X)) == 0 if and only if X is a power of 2. 307 */ 308 if ((mask & -mask) + mask != 0) { 309 struct ag_info nc_ag; 310 311 nc_ag.ag_dst_h = dst; 312 nc_ag.ag_mask = mask; 313 nc_ag.ag_gate = gate; 314 nc_ag.ag_nhop = nhop; 315 nc_ag.ag_metric = metric; 316 nc_ag.ag_pref = pref; 317 nc_ag.ag_tag = tag; 318 nc_ag.ag_state = state; 319 nc_ag.ag_seqno = new_seqno; 320 out(&nc_ag); 321 return; 322 } 323 324 /* Search for the right slot in the aggregation table. 325 */ 326 ag_cors = 0; 327 ag = ag_corsest; 328 while (ag != 0) { 329 if (ag->ag_mask >= mask) 330 break; 331 332 /* Suppress old routes (i.e. combine with compatible routes 333 * with coarser masks) as we look for the right slot in the 334 * aggregation table for the new route. 335 * A route to an address less than the current destination 336 * will not be affected by the current route or any route 337 * seen hereafter. That means it is safe to suppress it. 338 * This check keeps poor routes (e.g. with large hop counts) 339 * from preventing suppression of finer routes. 340 */ 341 if (ag_cors != 0 342 && ag->ag_dst_h < dst 343 && (ag->ag_state & AGS_SUPPRESS) 344 && ag_cors->ag_pref <= ag->ag_pref 345 && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h 346 && (ag_cors->ag_gate == ag->ag_gate 347 || (ag->ag_state & AGS_FINE_GATE) 348 || (ag_cors->ag_state & AGS_CORS_GATE))) { 349 /* If the suppressed target was redundant, 350 * then mark the suppressor redundant. 351 */ 352 if (AG_IS_REDUN(ag->ag_state) 353 && ag_cors->ag_mask == ag->ag_mask<<1) { 354 if (ag_cors->ag_dst_h == dst) 355 ag_cors->ag_state |= AGS_REDUN0; 356 else 357 ag_cors->ag_state |= AGS_REDUN1; 358 } 359 if (ag->ag_tag != ag_cors->ag_tag) 360 ag_cors->ag_tag = 0; 361 if (ag->ag_nhop != ag_cors->ag_nhop) 362 ag_cors->ag_nhop = 0; 363 ag_del(ag); 364 CHECK_AG(); 365 } else { 366 ag_cors = ag; 367 } 368 ag = ag_cors->ag_fine; 369 } 370 371 /* If we find the even/odd twin of the new route, and if the 372 * masks and so forth are equal, we can aggregate them. 373 * We can probably promote one of the pair. 374 * 375 * Since the routes are encountered in lexical order, 376 * the new route must be odd. However, the second or later 377 * times around this loop, it could be the even twin promoted 378 * from the even/odd pair of twins of the finer route. 379 */ 380 while (ag != 0 381 && ag->ag_mask == mask 382 && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) { 383 384 /* Here we know the target route and the route in the current 385 * slot have the same netmasks and differ by at most the 386 * last bit. They are either for the same destination, or 387 * for an even/odd pair of destinations. 388 */ 389 if (ag->ag_dst_h == dst) { 390 /* We have two routes to the same destination. 391 * Routes are encountered in lexical order, so a 392 * route is never promoted until the parent route is 393 * already present. So we know that the new route is 394 * a promoted (or aggregated) pair and the route 395 * already in the slot is the explicit route. 396 * 397 * Prefer the best route if their metrics differ, 398 * or the aggregated one if not, following a sort 399 * of longest-match rule. 400 */ 401 if (pref <= ag->ag_pref) { 402 ag->ag_gate = gate; 403 ag->ag_nhop = nhop; 404 ag->ag_tag = tag; 405 ag->ag_metric = metric; 406 ag->ag_pref = pref; 407 if (ag->ag_seqno < new_seqno) 408 ag->ag_seqno = new_seqno; 409 x = ag->ag_state; 410 ag->ag_state = state; 411 state = x; 412 } 413 414 /* Some bits are set if they are set on either route, 415 * except when the route is for an interface. 416 */ 417 if (!(ag->ag_state & AGS_IF)) 418 ag->ag_state |= (state & (AGS_AGGREGATE_EITHER 419 | AGS_REDUN0 420 | AGS_REDUN1)); 421 return; 422 } 423 424 /* If one of the routes can be promoted and the other can 425 * be suppressed, it may be possible to combine them or 426 * worthwhile to promote one. 427 * 428 * Any route that can be promoted is always 429 * marked to be eligible to be suppressed. 430 */ 431 if (!((state & AGS_AGGREGATE) 432 && (ag->ag_state & AGS_SUPPRESS)) 433 && !((ag->ag_state & AGS_AGGREGATE) 434 && (state & AGS_SUPPRESS))) 435 break; 436 437 /* A pair of even/odd twin routes can be combined 438 * if either is redundant, or if they are via the 439 * same gateway and have the same metric. 440 */ 441 if (AG_IS_REDUN(ag->ag_state) 442 || AG_IS_REDUN(state) 443 || (ag->ag_gate == gate 444 && ag->ag_pref == pref 445 && (state & ag->ag_state & AGS_AGGREGATE) != 0)) { 446 447 /* We have both the even and odd pairs. 448 * Since the routes are encountered in order, 449 * the route in the slot must be the even twin. 450 * 451 * Combine and promote (aggregate) the pair of routes. 452 */ 453 if (new_seqno < ag->ag_seqno) 454 new_seqno = ag->ag_seqno; 455 if (!AG_IS_REDUN(state)) 456 state &= ~AGS_REDUN1; 457 if (AG_IS_REDUN(ag->ag_state)) 458 state |= AGS_REDUN0; 459 else 460 state &= ~AGS_REDUN0; 461 state |= (ag->ag_state & AGS_AGGREGATE_EITHER); 462 if (ag->ag_tag != tag) 463 tag = 0; 464 if (ag->ag_nhop != nhop) 465 nhop = 0; 466 467 /* Get rid of the even twin that was already 468 * in the slot. 469 */ 470 ag_del(ag); 471 472 } else if (ag->ag_pref >= pref 473 && (ag->ag_state & AGS_AGGREGATE)) { 474 /* If we cannot combine the pair, maybe the route 475 * with the worse metric can be promoted. 476 * 477 * Promote the old, even twin, by giving its slot 478 * in the table to the new, odd twin. 479 */ 480 ag->ag_dst_h = dst; 481 482 xaddr = ag->ag_gate; 483 ag->ag_gate = gate; 484 gate = xaddr; 485 486 xaddr = ag->ag_nhop; 487 ag->ag_nhop = nhop; 488 nhop = xaddr; 489 490 x = ag->ag_tag; 491 ag->ag_tag = tag; 492 tag = x; 493 494 /* The promoted route is even-redundant only if the 495 * even twin was fully redundant. It is not 496 * odd-redundant because the odd-twin will still be 497 * in the table. 498 */ 499 x = ag->ag_state; 500 if (!AG_IS_REDUN(x)) 501 x &= ~AGS_REDUN0; 502 x &= ~AGS_REDUN1; 503 ag->ag_state = state; 504 state = x; 505 506 x = ag->ag_metric; 507 ag->ag_metric = metric; 508 metric = x; 509 510 x = ag->ag_pref; 511 ag->ag_pref = pref; 512 pref = x; 513 514 /* take the newest sequence number */ 515 if (new_seqno <= ag->ag_seqno) 516 new_seqno = ag->ag_seqno; 517 else 518 ag->ag_seqno = new_seqno; 519 520 } else { 521 if (!(state & AGS_AGGREGATE)) 522 break; /* cannot promote either twin */ 523 524 /* Promote the new, odd twin by shaving its 525 * mask and address. 526 * The promoted route is odd-redundant only if the 527 * odd twin was fully redundant. It is not 528 * even-redundant because the even twin is still in 529 * the table. 530 */ 531 if (!AG_IS_REDUN(state)) 532 state &= ~AGS_REDUN1; 533 state &= ~AGS_REDUN0; 534 if (new_seqno < ag->ag_seqno) 535 new_seqno = ag->ag_seqno; 536 else 537 ag->ag_seqno = new_seqno; 538 } 539 540 mask <<= 1; 541 dst &= mask; 542 543 if (ag_cors == 0) { 544 ag = ag_corsest; 545 break; 546 } 547 ag = ag_cors; 548 ag_cors = ag->ag_cors; 549 } 550 551 /* When we can no longer promote and combine routes, 552 * flush the old route in the target slot. Also flush 553 * any finer routes that we know will never be aggregated by 554 * the new route. 555 * 556 * In case we moved toward coarser masks, 557 * get back where we belong 558 */ 559 if (ag != 0 560 && ag->ag_mask < mask) { 561 ag_cors = ag; 562 ag = ag->ag_fine; 563 } 564 565 /* Empty the target slot 566 */ 567 if (ag != 0 && ag->ag_mask == mask) { 568 ag_flush(ag->ag_dst_h, ag->ag_mask, out); 569 ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine; 570 } 571 572 #ifdef DEBUG_AG 573 (void)fflush(stderr); 574 if (ag == 0 && ag_cors != ag_finest) 575 abort(); 576 if (ag_cors == 0 && ag != ag_corsest) 577 abort(); 578 if (ag != 0 && ag->ag_cors != ag_cors) 579 abort(); 580 if (ag_cors != 0 && ag_cors->ag_fine != ag) 581 abort(); 582 CHECK_AG(); 583 #endif 584 585 /* Save the new route on the end of the table. 586 */ 587 nag = ag_avail; 588 ag_avail = nag->ag_fine; 589 590 nag->ag_dst_h = dst; 591 nag->ag_mask = mask; 592 nag->ag_gate = gate; 593 nag->ag_nhop = nhop; 594 nag->ag_metric = metric; 595 nag->ag_pref = pref; 596 nag->ag_tag = tag; 597 nag->ag_state = state; 598 nag->ag_seqno = new_seqno; 599 600 nag->ag_fine = ag; 601 if (ag != 0) 602 ag->ag_cors = nag; 603 else 604 ag_finest = nag; 605 nag->ag_cors = ag_cors; 606 if (ag_cors == 0) 607 ag_corsest = nag; 608 else 609 ag_cors->ag_fine = nag; 610 CHECK_AG(); 611 } 612 613 614 static const char * 615 rtm_type_name(u_char type) 616 { 617 static const char *rtm_types[] = { 618 "RTM_ADD", 619 "RTM_DELETE", 620 "RTM_CHANGE", 621 "RTM_GET", 622 "RTM_LOSING", 623 "RTM_REDIRECT", 624 "RTM_MISS", 625 "RTM_LOCK", 626 "RTM_OLDADD", 627 "RTM_OLDDEL", 628 "RTM_RESOLVE", 629 "RTM_NEWADDR", 630 "RTM_DELADDR", 631 #ifdef RTM_OIFINFO 632 "RTM_OIFINFO", 633 #endif 634 "RTM_IFINFO", 635 "RTM_NEWMADDR", 636 "RTM_DELMADDR" 637 }; 638 #define NEW_RTM_PAT "RTM type %#x" 639 static char name0[sizeof(NEW_RTM_PAT)+2]; 640 641 642 if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) 643 || type == 0) { 644 snprintf(name0, sizeof(name0), NEW_RTM_PAT, type); 645 return name0; 646 } else { 647 return rtm_types[type-1]; 648 } 649 #undef NEW_RTM_PAT 650 } 651 652 653 /* Trim a mask in a sockaddr 654 * Produce a length of 0 for an address of 0. 655 * Otherwise produce the index of the first zero byte. 656 */ 657 void 658 #ifdef _HAVE_SIN_LEN 659 masktrim(struct sockaddr_in *ap) 660 #else 661 masktrim(struct sockaddr_in_new *ap) 662 #endif 663 { 664 char *cp; 665 666 if (ap->sin_addr.s_addr == 0) { 667 ap->sin_len = 0; 668 return; 669 } 670 cp = (char *)(&ap->sin_addr.s_addr+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 */ 679 static void 680 rtioctl(int action, /* RTM_DELETE, etc */ 681 naddr dst, 682 naddr gate, 683 naddr mask, 684 int metric, 685 int flags) 686 { 687 struct { 688 struct rt_msghdr w_rtm; 689 struct sockaddr_in w_dst; 690 struct sockaddr_in w_gate; 691 #ifdef _HAVE_SA_LEN 692 struct sockaddr_in w_mask; 693 #else 694 struct sockaddr_in_new w_mask; 695 #endif 696 } w; 697 long cc; 698 # define PAT " %-10s %s metric=%d flags=%#x" 699 # define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags 700 701 again: 702 memset(&w, 0, sizeof(w)); 703 w.w_rtm.rtm_msglen = sizeof(w); 704 w.w_rtm.rtm_version = RTM_VERSION; 705 w.w_rtm.rtm_type = action; 706 w.w_rtm.rtm_flags = flags; 707 w.w_rtm.rtm_seq = ++rt_sock_seqno; 708 w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY; 709 if (metric != 0 || action == RTM_CHANGE) { 710 w.w_rtm.rtm_rmx.rmx_hopcount = metric; 711 w.w_rtm.rtm_inits |= RTV_HOPCOUNT; 712 } 713 w.w_dst.sin_family = AF_INET; 714 w.w_dst.sin_addr.s_addr = dst; 715 w.w_gate.sin_family = AF_INET; 716 w.w_gate.sin_addr.s_addr = gate; 717 #ifdef _HAVE_SA_LEN 718 w.w_dst.sin_len = sizeof(w.w_dst); 719 w.w_gate.sin_len = sizeof(w.w_gate); 720 #endif 721 if (mask == HOST_MASK) { 722 w.w_rtm.rtm_flags |= RTF_HOST; 723 w.w_rtm.rtm_msglen -= sizeof(w.w_mask); 724 } else { 725 w.w_rtm.rtm_addrs |= RTA_NETMASK; 726 w.w_mask.sin_addr.s_addr = htonl(mask); 727 #ifdef _HAVE_SA_LEN 728 masktrim(&w.w_mask); 729 if (w.w_mask.sin_len == 0) 730 w.w_mask.sin_len = sizeof(long); 731 w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len); 732 #endif 733 } 734 735 #ifndef NO_INSTALL 736 cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); 737 if (cc < 0) { 738 if (errno == ESRCH 739 && (action == RTM_CHANGE || action == RTM_DELETE)) { 740 trace_act("route disappeared before" PAT, ARGS); 741 if (action == RTM_CHANGE) { 742 action = RTM_ADD; 743 goto again; 744 } 745 return; 746 } 747 msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno)); 748 return; 749 } else if (cc != w.w_rtm.rtm_msglen) { 750 msglog("write(rt_sock) wrote %ld instead of %d for" PAT, 751 cc, w.w_rtm.rtm_msglen, ARGS); 752 return; 753 } 754 #endif 755 if (TRACEKERNEL) 756 trace_misc("write kernel" PAT, ARGS); 757 #undef PAT 758 #undef ARGS 759 } 760 761 762 #define KHASH_SIZE 71 /* should be prime */ 763 #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE] 764 static struct khash { 765 struct khash *k_next; 766 naddr k_dst; 767 naddr k_mask; 768 naddr k_gate; 769 short k_metric; 770 u_short k_state; 771 #define KS_NEW 0x001 772 #define KS_DELETE 0x002 /* need to delete the route */ 773 #define KS_ADD 0x004 /* add to the kernel */ 774 #define KS_CHANGE 0x008 /* tell kernel to change the route */ 775 #define KS_DEL_ADD 0x010 /* delete & add to change the kernel */ 776 #define KS_STATIC 0x020 /* Static flag in kernel */ 777 #define KS_GATEWAY 0x040 /* G flag in kernel */ 778 #define KS_DYNAMIC 0x080 /* result of redirect */ 779 #define KS_DELETED 0x100 /* already deleted from kernel */ 780 #define KS_CHECK 0x200 781 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]; 785 786 787 static struct khash* 788 kern_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 } 800 801 802 static struct khash* 803 kern_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 */ 827 static void 828 kern_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 */ 856 static void 857 kern_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 */ 886 static void 887 rtm_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 */ 990 static void 991 rtm_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 */ 1011 static int 1012 get_info_gate(struct sockaddr **sap, 1013 struct sockaddr_in *rsin) 1014 { 1015 struct sockaddr_dl *sdl = (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 = (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 */ 1043 void 1044 flush_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 #if defined(RTF_CLONED) && defined(__bsdi__) 1116 /* ignore cloned routes 1117 */ 1118 if (rtm->rtm_flags & RTF_CLONED) 1119 continue; 1120 #endif 1121 1122 /* ignore multicast addresses 1123 */ 1124 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1125 continue; 1126 1127 if (!get_info_gate(&INFO_GATE(&info), &gate_sin)) 1128 continue; 1129 1130 /* Note static routes and interface routes, and also 1131 * preload the image of the kernel table so that 1132 * we can later clean it, as well as avoid making 1133 * unneeded changes. Keep the old kernel routes for a 1134 * few seconds to allow a RIP or router-discovery 1135 * response to be heard. 1136 */ 1137 rtm_add(rtm,&info,MIN_WAITTIME); 1138 } 1139 1140 for (i = 0; i < KHASH_SIZE; i++) { 1141 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1142 if (k->k_state & KS_CHECK) { 1143 msglog("%s --> %s disappeared from kernel", 1144 addrname(k->k_dst, k->k_mask, 0), 1145 naddr_ntoa(k->k_gate)); 1146 del_static(k->k_dst, k->k_mask, k->k_gate, 1); 1147 } 1148 } 1149 } 1150 } 1151 1152 1153 /* Listen to announcements from the kernel 1154 */ 1155 void 1156 read_rt(void) 1157 { 1158 long cc; 1159 struct interface *ifp; 1160 struct sockaddr_in gate_sin; 1161 naddr mask, gate; 1162 union { 1163 struct { 1164 struct rt_msghdr rtm; 1165 struct sockaddr addrs[RTAX_MAX]; 1166 } r; 1167 struct if_msghdr ifm; 1168 } m; 1169 char str[100], *strp; 1170 struct rt_addrinfo info; 1171 1172 1173 for (;;) { 1174 cc = read(rt_sock, &m, sizeof(m)); 1175 if (cc <= 0) { 1176 if (cc < 0 && errno != EWOULDBLOCK) 1177 LOGERR("read(rt_sock)"); 1178 return; 1179 } 1180 1181 if (m.r.rtm.rtm_version != RTM_VERSION) { 1182 msglog("bogus routing message version %d", 1183 m.r.rtm.rtm_version); 1184 continue; 1185 } 1186 1187 /* Ignore our own results. 1188 */ 1189 if (m.r.rtm.rtm_type <= RTM_CHANGE 1190 && m.r.rtm.rtm_pid == mypid) { 1191 static int complained = 0; 1192 if (!complained) { 1193 msglog("receiving our own change messages"); 1194 complained = 1; 1195 } 1196 continue; 1197 } 1198 1199 if (m.r.rtm.rtm_type == RTM_IFINFO 1200 || m.r.rtm.rtm_type == RTM_NEWADDR 1201 || m.r.rtm.rtm_type == RTM_DELADDR) { 1202 ifp = ifwithindex(m.ifm.ifm_index, 1203 m.r.rtm.rtm_type != RTM_DELADDR); 1204 if (ifp == 0) 1205 trace_act("note %s with flags %#x" 1206 " for unknown interface index #%d", 1207 rtm_type_name(m.r.rtm.rtm_type), 1208 m.ifm.ifm_flags, 1209 m.ifm.ifm_index); 1210 else 1211 trace_act("note %s with flags %#x for %s", 1212 rtm_type_name(m.r.rtm.rtm_type), 1213 m.ifm.ifm_flags, 1214 ifp->int_name); 1215 1216 /* After being informed of a change to an interface, 1217 * check them all now if the check would otherwise 1218 * be a long time from now, if the interface is 1219 * not known, or if the interface has been turned 1220 * off or on. 1221 */ 1222 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1223 || ifp == 0 1224 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1225 & IFF_UP) != 0) 1226 ifinit_timer.tv_sec = now.tv_sec; 1227 continue; 1228 } 1229 #ifdef RTM_OIFINFO 1230 if (m.r.rtm.rtm_type == RTM_OIFINFO) 1231 continue; /* ignore compat message */ 1232 #endif 1233 1234 strcpy(str, rtm_type_name(m.r.rtm.rtm_type)); 1235 strp = &str[strlen(str)]; 1236 if (m.r.rtm.rtm_type <= RTM_CHANGE) 1237 strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid); 1238 1239 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1240 m.r.rtm.rtm_addrs); 1241 1242 if (INFO_DST(&info) == 0) { 1243 trace_act("ignore %s without dst", str); 1244 continue; 1245 } 1246 1247 if (INFO_DST(&info)->sa_family != AF_INET) { 1248 trace_act("ignore %s for AF %d", str, 1249 INFO_DST(&info)->sa_family); 1250 continue; 1251 } 1252 1253 mask = ((INFO_MASK(&info) != 0) 1254 ? ntohl(S_ADDR(INFO_MASK(&info))) 1255 : (m.r.rtm.rtm_flags & RTF_HOST) 1256 ? HOST_MASK 1257 : std_mask(S_ADDR(INFO_DST(&info)))); 1258 1259 strp += sprintf(strp, ": %s", 1260 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1261 1262 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1263 trace_act("ignore multicast %s", str); 1264 continue; 1265 } 1266 1267 if (m.r.rtm.rtm_flags & RTF_LLINFO) { 1268 trace_act("ignore ARP %s", str); 1269 continue; 1270 } 1271 1272 #if defined(RTF_CLONED) && defined(__bsdi__) 1273 if (m.r.rtm.rtm_flags & RTF_CLONED) { 1274 trace_act("ignore cloned %s", str); 1275 continue; 1276 } 1277 #endif 1278 1279 if (get_info_gate(&INFO_GATE(&info), &gate_sin)) { 1280 gate = S_ADDR(INFO_GATE(&info)); 1281 strp += sprintf(strp, " --> %s", naddr_ntoa(gate)); 1282 } else { 1283 gate = 0; 1284 } 1285 1286 if (INFO_AUTHOR(&info) != 0) 1287 strp += sprintf(strp, " by authority of %s", 1288 saddr_ntoa(INFO_AUTHOR(&info))); 1289 1290 switch (m.r.rtm.rtm_type) { 1291 case RTM_ADD: 1292 case RTM_CHANGE: 1293 case RTM_REDIRECT: 1294 if (m.r.rtm.rtm_errno != 0) { 1295 trace_act("ignore %s with \"%s\" error", 1296 str, strerror(m.r.rtm.rtm_errno)); 1297 } else { 1298 trace_act("%s", str); 1299 rtm_add(&m.r.rtm,&info,0); 1300 } 1301 break; 1302 1303 case RTM_DELETE: 1304 if (m.r.rtm.rtm_errno != 0 1305 && m.r.rtm.rtm_errno != ESRCH) { 1306 trace_act("ignore %s with \"%s\" error", 1307 str, strerror(m.r.rtm.rtm_errno)); 1308 } else { 1309 trace_act("%s", str); 1310 del_static(S_ADDR(INFO_DST(&info)), mask, 1311 gate, 1); 1312 } 1313 break; 1314 1315 case RTM_LOSING: 1316 trace_act("%s", str); 1317 rtm_lose(&m.r.rtm,&info); 1318 break; 1319 1320 default: 1321 trace_act("ignore %s", str); 1322 break; 1323 } 1324 } 1325 } 1326 1327 1328 /* after aggregating, note routes that belong in the kernel 1329 */ 1330 static void 1331 kern_out(struct ag_info *ag) 1332 { 1333 struct khash *k; 1334 1335 1336 /* Do not install bad routes if they are not already present. 1337 * This includes routes that had RS_NET_SYN for interfaces that 1338 * recently died. 1339 */ 1340 if (ag->ag_metric == HOPCNT_INFINITY) { 1341 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1342 if (k == 0) 1343 return; 1344 } else { 1345 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1346 } 1347 1348 if (k->k_state & KS_NEW) { 1349 /* will need to add new entry to the kernel table */ 1350 k->k_state = KS_ADD; 1351 if (ag->ag_state & AGS_GATEWAY) 1352 k->k_state |= KS_GATEWAY; 1353 k->k_gate = ag->ag_gate; 1354 k->k_metric = ag->ag_metric; 1355 return; 1356 } 1357 1358 if (k->k_state & KS_STATIC) 1359 return; 1360 1361 /* modify existing kernel entry if necessary */ 1362 if (k->k_gate != ag->ag_gate 1363 || k->k_metric != ag->ag_metric) { 1364 /* Must delete bad interface routes etc. to change them. */ 1365 if (k->k_metric == HOPCNT_INFINITY) 1366 k->k_state |= KS_DEL_ADD; 1367 k->k_gate = ag->ag_gate; 1368 k->k_metric = ag->ag_metric; 1369 k->k_state |= KS_CHANGE; 1370 } 1371 1372 /* If the daemon thinks the route should exist, forget 1373 * about any redirections. 1374 * If the daemon thinks the route should exist, eventually 1375 * override manual intervention by the operator. 1376 */ 1377 if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) { 1378 k->k_state &= ~KS_DYNAMIC; 1379 k->k_state |= (KS_ADD | KS_DEL_ADD); 1380 } 1381 1382 if ((k->k_state & KS_GATEWAY) 1383 && !(ag->ag_state & AGS_GATEWAY)) { 1384 k->k_state &= ~KS_GATEWAY; 1385 k->k_state |= (KS_ADD | KS_DEL_ADD); 1386 } else if (!(k->k_state & KS_GATEWAY) 1387 && (ag->ag_state & AGS_GATEWAY)) { 1388 k->k_state |= KS_GATEWAY; 1389 k->k_state |= (KS_ADD | KS_DEL_ADD); 1390 } 1391 1392 /* Deleting-and-adding is necessary to change aspects of a route. 1393 * Just delete instead of deleting and then adding a bad route. 1394 * Otherwise, we want to keep the route in the kernel. 1395 */ 1396 if (k->k_metric == HOPCNT_INFINITY 1397 && (k->k_state & KS_DEL_ADD)) 1398 k->k_state |= KS_DELETE; 1399 else 1400 k->k_state &= ~KS_DELETE; 1401 #undef RT 1402 } 1403 1404 1405 /* ARGSUSED */ 1406 static int 1407 walk_kern(struct radix_node *rn, 1408 struct walkarg *argp UNUSED) 1409 { 1410 #define RT ((struct rt_entry *)rn) 1411 char metric, pref; 1412 u_int ags = 0; 1413 1414 1415 /* Do not install synthetic routes */ 1416 if (RT->rt_state & RS_NET_SYN) 1417 return 0; 1418 1419 if (!(RT->rt_state & RS_IF)) { 1420 /* This is an ordinary route, not for an interface. 1421 */ 1422 1423 /* aggregate, ordinary good routes without regard to 1424 * their metric 1425 */ 1426 pref = 1; 1427 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1428 1429 /* Do not install host routes directly to hosts, to avoid 1430 * interfering with ARP entries in the kernel table. 1431 */ 1432 if (RT_ISHOST(RT) 1433 && ntohl(RT->rt_dst) == RT->rt_gate) 1434 return 0; 1435 1436 } else { 1437 /* This is an interface route. 1438 * Do not install routes for "external" remote interfaces. 1439 */ 1440 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1441 return 0; 1442 1443 /* Interfaces should override received routes. 1444 */ 1445 pref = 0; 1446 ags |= (AGS_IF | AGS_CORS_GATE); 1447 1448 /* If it is not an interface, or an alias for an interface, 1449 * it must be a "gateway." 1450 * 1451 * If it is a "remote" interface, it is also a "gateway" to 1452 * the kernel if is not a alias. 1453 */ 1454 if (RT->rt_ifp == 0 1455 || (RT->rt_ifp->int_state & IS_REMOTE)) 1456 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE); 1457 } 1458 1459 /* If RIP is off and IRDP is on, let the route to the discovered 1460 * route suppress any RIP routes. Eventually the RIP routes 1461 * will time-out and be deleted. This reaches the steady-state 1462 * quicker. 1463 */ 1464 if ((RT->rt_state & RS_RDISC) && rip_sock < 0) 1465 ags |= AGS_CORS_GATE; 1466 1467 metric = RT->rt_metric; 1468 if (metric == HOPCNT_INFINITY) { 1469 /* if the route is dead, so try hard to aggregate. */ 1470 pref = HOPCNT_INFINITY; 1471 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1472 ags &= ~(AGS_IF | AGS_CORS_GATE); 1473 } 1474 1475 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1476 metric,pref, 0, 0, ags, kern_out); 1477 return 0; 1478 #undef RT 1479 } 1480 1481 1482 /* Update the kernel table to match the daemon table. 1483 */ 1484 static void 1485 fix_kern(void) 1486 { 1487 int i; 1488 struct khash *k, **pk; 1489 1490 1491 need_kern = age_timer; 1492 1493 /* Walk daemon table, updating the copy of the kernel table. 1494 */ 1495 (void)rn_walktree(rhead, walk_kern, 0); 1496 ag_flush(0,0,kern_out); 1497 1498 for (i = 0; i < KHASH_SIZE; i++) { 1499 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1500 /* Do not touch static routes */ 1501 if (k->k_state & KS_STATIC) { 1502 kern_check_static(k,0); 1503 pk = &k->k_next; 1504 continue; 1505 } 1506 1507 /* check hold on routes deleted by the operator */ 1508 if (k->k_keep > now.tv_sec) { 1509 /* ensure we check when the hold is over */ 1510 LIM_SEC(need_kern, k->k_keep); 1511 /* mark for the next cycle */ 1512 k->k_state |= KS_DELETE; 1513 pk = &k->k_next; 1514 continue; 1515 } 1516 1517 if ((k->k_state & KS_DELETE) 1518 && !(k->k_state & KS_DYNAMIC)) { 1519 kern_ioctl(k, RTM_DELETE, 0); 1520 *pk = k->k_next; 1521 free(k); 1522 continue; 1523 } 1524 1525 if (k->k_state & KS_DEL_ADD) 1526 kern_ioctl(k, RTM_DELETE, 0); 1527 1528 if (k->k_state & KS_ADD) { 1529 kern_ioctl(k, RTM_ADD, 1530 ((0 != (k->k_state & (KS_GATEWAY 1531 | KS_DYNAMIC))) 1532 ? RTF_GATEWAY : 0)); 1533 } else if (k->k_state & KS_CHANGE) { 1534 kern_ioctl(k, RTM_CHANGE, 1535 ((0 != (k->k_state & (KS_GATEWAY 1536 | KS_DYNAMIC))) 1537 ? RTF_GATEWAY : 0)); 1538 } 1539 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1540 1541 /* Mark this route to be deleted in the next cycle. 1542 * This deletes routes that disappear from the 1543 * daemon table, since the normal aging code 1544 * will clear the bit for routes that have not 1545 * disappeared from the daemon table. 1546 */ 1547 k->k_state |= KS_DELETE; 1548 pk = &k->k_next; 1549 } 1550 } 1551 } 1552 1553 1554 /* Delete a static route in the image of the kernel table. 1555 */ 1556 void 1557 del_static(naddr dst, 1558 naddr mask, 1559 naddr gate, 1560 int gone) 1561 { 1562 struct khash *k; 1563 struct rt_entry *rt; 1564 1565 /* Just mark it in the table to be deleted next time the kernel 1566 * table is updated. 1567 * If it has already been deleted, mark it as such, and set its 1568 * keep-timer so that it will not be deleted again for a while. 1569 * This lets the operator delete a route added by the daemon 1570 * and add a replacement. 1571 */ 1572 k = kern_find(dst, mask, 0); 1573 if (k != 0 && (gate == 0 || k->k_gate == gate)) { 1574 k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK); 1575 k->k_state |= KS_DELETE; 1576 if (gone) { 1577 k->k_state |= KS_DELETED; 1578 k->k_keep = now.tv_sec + K_KEEP_LIM; 1579 } 1580 } 1581 1582 rt = rtget(dst, mask); 1583 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1584 rtbad(rt); 1585 } 1586 1587 1588 /* Delete all routes generated from ICMP Redirects that use a given gateway, 1589 * as well as old redirected routes. 1590 */ 1591 void 1592 del_redirects(naddr bad_gate, 1593 time_t old) 1594 { 1595 int i; 1596 struct khash *k; 1597 1598 1599 for (i = 0; i < KHASH_SIZE; i++) { 1600 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1601 if (!(k->k_state & KS_DYNAMIC) 1602 || (k->k_state & KS_STATIC)) 1603 continue; 1604 1605 if (k->k_gate != bad_gate 1606 && k->k_redirect_time > old 1607 && !supplier) 1608 continue; 1609 1610 k->k_state |= KS_DELETE; 1611 k->k_state &= ~KS_DYNAMIC; 1612 need_kern.tv_sec = now.tv_sec; 1613 trace_act("mark redirected %s --> %s for deletion", 1614 addrname(k->k_dst, k->k_mask, 0), 1615 naddr_ntoa(k->k_gate)); 1616 } 1617 } 1618 } 1619 1620 1621 /* Start the daemon tables. 1622 */ 1623 extern int max_keylen; 1624 1625 void 1626 rtinit(void) 1627 { 1628 int i; 1629 struct ag_info *ag; 1630 1631 /* Initialize the radix trees */ 1632 max_keylen = sizeof(struct sockaddr_in); 1633 rn_init(); 1634 rn_inithead((void*)&rhead, 32); 1635 1636 /* mark all of the slots in the table free */ 1637 ag_avail = ag_slots; 1638 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1639 ag->ag_fine = ag+1; 1640 ag++; 1641 } 1642 } 1643 1644 1645 #ifdef _HAVE_SIN_LEN 1646 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}}; 1647 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}}; 1648 #else 1649 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1650 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1651 #endif 1652 1653 1654 static void 1655 set_need_flash(void) 1656 { 1657 if (!need_flash) { 1658 need_flash = 1; 1659 /* Do not send the flash update immediately. Wait a little 1660 * while to hear from other routers. 1661 */ 1662 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1663 } 1664 } 1665 1666 1667 /* Get a particular routing table entry 1668 */ 1669 struct rt_entry * 1670 rtget(naddr dst, naddr mask) 1671 { 1672 struct rt_entry *rt; 1673 1674 dst_sock.sin_addr.s_addr = dst; 1675 mask_sock.sin_addr.s_addr = htonl(mask); 1676 masktrim(&mask_sock); 1677 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1678 if (!rt 1679 || rt->rt_dst != dst 1680 || rt->rt_mask != mask) 1681 return 0; 1682 1683 return rt; 1684 } 1685 1686 1687 /* Find a route to dst as the kernel would. 1688 */ 1689 struct rt_entry * 1690 rtfind(naddr dst) 1691 { 1692 dst_sock.sin_addr.s_addr = dst; 1693 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1694 } 1695 1696 1697 /* add a route to the table 1698 */ 1699 void 1700 rtadd(naddr dst, 1701 naddr mask, 1702 u_int state, /* rt_state for the entry */ 1703 struct rt_spare *new) 1704 { 1705 struct rt_entry *rt; 1706 naddr smask; 1707 int i; 1708 struct rt_spare *rts; 1709 1710 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1711 memset(rt, 0, sizeof(*rt)); 1712 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1713 rts->rts_metric = HOPCNT_INFINITY; 1714 1715 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1716 rt->rt_dst = dst; 1717 rt->rt_dst_sock.sin_family = AF_INET; 1718 #ifdef _HAVE_SIN_LEN 1719 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1720 #endif 1721 if (mask != HOST_MASK) { 1722 smask = std_mask(dst); 1723 if ((smask & ~mask) == 0 && mask > smask) 1724 state |= RS_SUBNET; 1725 } 1726 mask_sock.sin_addr.s_addr = htonl(mask); 1727 masktrim(&mask_sock); 1728 rt->rt_mask = mask; 1729 rt->rt_state = state; 1730 rt->rt_spares[0] = *new; 1731 rt->rt_time = now.tv_sec; 1732 rt->rt_poison_metric = HOPCNT_INFINITY; 1733 rt->rt_seqno = update_seqno; 1734 1735 if (++total_routes == MAX_ROUTES) 1736 msglog("have maximum (%d) routes", total_routes); 1737 if (TRACEACTIONS) 1738 trace_add_del("Add", rt); 1739 1740 need_kern.tv_sec = now.tv_sec; 1741 set_need_flash(); 1742 1743 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1744 rhead, rt->rt_nodes)) { 1745 msglog("rnh_addaddr() failed for %s mask=%#lx", 1746 naddr_ntoa(dst), (u_long)mask); 1747 free(rt); 1748 } 1749 } 1750 1751 1752 /* notice a changed route 1753 */ 1754 void 1755 rtchange(struct rt_entry *rt, 1756 u_int state, /* new state bits */ 1757 struct rt_spare *new, 1758 char *label) 1759 { 1760 if (rt->rt_metric != new->rts_metric) { 1761 /* Fix the kernel immediately if it seems the route 1762 * has gone bad, since there may be a working route that 1763 * aggregates this route. 1764 */ 1765 if (new->rts_metric == HOPCNT_INFINITY) { 1766 need_kern.tv_sec = now.tv_sec; 1767 if (new->rts_time >= now.tv_sec - EXPIRE_TIME) 1768 new->rts_time = now.tv_sec - EXPIRE_TIME; 1769 } 1770 rt->rt_seqno = update_seqno; 1771 set_need_flash(); 1772 } 1773 1774 if (rt->rt_gate != new->rts_gate) { 1775 need_kern.tv_sec = now.tv_sec; 1776 rt->rt_seqno = update_seqno; 1777 set_need_flash(); 1778 } 1779 1780 state |= (rt->rt_state & RS_SUBNET); 1781 1782 /* Keep various things from deciding ageless routes are stale. 1783 */ 1784 if (!AGE_RT(state, new->rts_ifp)) 1785 new->rts_time = now.tv_sec; 1786 1787 if (TRACEACTIONS) 1788 trace_change(rt, state, new, 1789 label ? label : "Chg "); 1790 1791 rt->rt_state = state; 1792 rt->rt_spares[0] = *new; 1793 } 1794 1795 1796 /* check for a better route among the spares 1797 */ 1798 static struct rt_spare * 1799 rts_better(struct rt_entry *rt) 1800 { 1801 struct rt_spare *rts, *rts1; 1802 int i; 1803 1804 /* find the best alternative among the spares */ 1805 rts = rt->rt_spares+1; 1806 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1807 if (BETTER_LINK(rt,rts1,rts)) 1808 rts = rts1; 1809 } 1810 1811 return rts; 1812 } 1813 1814 1815 /* switch to a backup route 1816 */ 1817 void 1818 rtswitch(struct rt_entry *rt, 1819 struct rt_spare *rts) 1820 { 1821 struct rt_spare swap; 1822 char label[10]; 1823 1824 1825 /* Do not change permanent routes */ 1826 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1827 | RS_NET_SYN | RS_IF))) 1828 return; 1829 1830 /* find the best alternative among the spares */ 1831 if (rts == 0) 1832 rts = rts_better(rt); 1833 1834 /* Do not bother if it is not worthwhile. 1835 */ 1836 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1837 return; 1838 1839 swap = rt->rt_spares[0]; 1840 (void)sprintf(label, "Use #%d", (int)(rts - rt->rt_spares)); 1841 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label); 1842 if (swap.rts_metric == HOPCNT_INFINITY) { 1843 *rts = rts_empty; 1844 } else { 1845 *rts = swap; 1846 } 1847 } 1848 1849 1850 void 1851 rtdelete(struct rt_entry *rt) 1852 { 1853 struct khash *k; 1854 1855 1856 if (TRACEACTIONS) 1857 trace_add_del("Del", rt); 1858 1859 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1860 if (k != 0) { 1861 k->k_state |= KS_DELETE; 1862 need_kern.tv_sec = now.tv_sec; 1863 } 1864 1865 dst_sock.sin_addr.s_addr = rt->rt_dst; 1866 mask_sock.sin_addr.s_addr = htonl(rt->rt_mask); 1867 masktrim(&mask_sock); 1868 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1869 rhead)) { 1870 msglog("rnh_deladdr() failed"); 1871 } else { 1872 free(rt); 1873 total_routes--; 1874 } 1875 } 1876 1877 1878 void 1879 rts_delete(struct rt_entry *rt, 1880 struct rt_spare *rts) 1881 { 1882 trace_upslot(rt, rts, &rts_empty); 1883 *rts = rts_empty; 1884 } 1885 1886 1887 /* Get rid of a bad route, and try to switch to a replacement. 1888 */ 1889 void 1890 rtbad(struct rt_entry *rt) 1891 { 1892 struct rt_spare new; 1893 1894 /* Poison the route */ 1895 new = rt->rt_spares[0]; 1896 new.rts_metric = HOPCNT_INFINITY; 1897 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0); 1898 rtswitch(rt, 0); 1899 } 1900 1901 1902 /* Junk a RS_NET_SYN or RS_LOCAL route, 1903 * unless it is needed by another interface. 1904 */ 1905 void 1906 rtbad_sub(struct rt_entry *rt) 1907 { 1908 struct interface *ifp, *ifp1; 1909 struct intnet *intnetp; 1910 u_int state; 1911 1912 1913 ifp1 = 0; 1914 state = 0; 1915 1916 if (rt->rt_state & RS_LOCAL) { 1917 /* Is this the route through loopback for the interface? 1918 * If so, see if it is used by any other interfaces, such 1919 * as a point-to-point interface with the same local address. 1920 */ 1921 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1922 /* Retain it if another interface needs it. 1923 */ 1924 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1925 state |= RS_LOCAL; 1926 ifp1 = ifp; 1927 break; 1928 } 1929 } 1930 1931 } 1932 1933 if (!(state & RS_LOCAL)) { 1934 /* Retain RIPv1 logical network route if there is another 1935 * interface that justifies it. 1936 */ 1937 if (rt->rt_state & RS_NET_SYN) { 1938 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1939 if ((ifp->int_state & IS_NEED_NET_SYN) 1940 && rt->rt_mask == ifp->int_std_mask 1941 && rt->rt_dst == ifp->int_std_addr) { 1942 state |= RS_NET_SYN; 1943 ifp1 = ifp; 1944 break; 1945 } 1946 } 1947 } 1948 1949 /* or if there is an authority route that needs it. */ 1950 for (intnetp = intnets; 1951 intnetp != 0; 1952 intnetp = intnetp->intnet_next) { 1953 if (intnetp->intnet_addr == rt->rt_dst 1954 && intnetp->intnet_mask == rt->rt_mask) { 1955 state |= (RS_NET_SYN | RS_NET_INT); 1956 break; 1957 } 1958 } 1959 } 1960 1961 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1962 struct rt_spare new = rt->rt_spares[0]; 1963 new.rts_ifp = ifp1; 1964 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state), 1965 &new, 0); 1966 } else { 1967 rtbad(rt); 1968 } 1969 } 1970 1971 1972 /* Called while walking the table looking for sick interfaces 1973 * or after a time change. 1974 */ 1975 /* ARGSUSED */ 1976 int 1977 walk_bad(struct radix_node *rn, 1978 struct walkarg *argp UNUSED) 1979 { 1980 #define RT ((struct rt_entry *)rn) 1981 struct rt_spare *rts; 1982 int i; 1983 1984 1985 /* fix any spare routes through the interface 1986 */ 1987 rts = RT->rt_spares; 1988 for (i = NUM_SPARES; i != 1; i--) { 1989 rts++; 1990 if (rts->rts_metric < HOPCNT_INFINITY 1991 && (rts->rts_ifp == 0 1992 || (rts->rts_ifp->int_state & IS_BROKE))) 1993 rts_delete(RT, rts); 1994 } 1995 1996 /* Deal with the main route 1997 */ 1998 /* finished if it has been handled before or if its interface is ok 1999 */ 2000 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 2001 return 0; 2002 2003 /* Bad routes for other than interfaces are easy. 2004 */ 2005 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 2006 rtbad(RT); 2007 return 0; 2008 } 2009 2010 rtbad_sub(RT); 2011 return 0; 2012 #undef RT 2013 } 2014 2015 2016 /* Check the age of an individual route. 2017 */ 2018 /* ARGSUSED */ 2019 static int 2020 walk_age(struct radix_node *rn, 2021 struct walkarg *argp UNUSED) 2022 { 2023 #define RT ((struct rt_entry *)rn) 2024 struct interface *ifp; 2025 struct rt_spare *rts; 2026 int i; 2027 2028 2029 /* age all of the spare routes, including the primary route 2030 * currently in use 2031 */ 2032 rts = RT->rt_spares; 2033 for (i = NUM_SPARES; i != 0; i--, rts++) { 2034 2035 ifp = rts->rts_ifp; 2036 if (i == NUM_SPARES) { 2037 if (!AGE_RT(RT->rt_state, ifp)) { 2038 /* Keep various things from deciding ageless 2039 * routes are stale 2040 */ 2041 rts->rts_time = now.tv_sec; 2042 continue; 2043 } 2044 2045 /* forget RIP routes after RIP has been turned off. 2046 */ 2047 if (rip_sock < 0) { 2048 rtdelete(RT); 2049 return 0; 2050 } 2051 } 2052 2053 /* age failing routes 2054 */ 2055 if (age_bad_gate == rts->rts_gate 2056 && rts->rts_time >= now_stale) { 2057 rts->rts_time -= SUPPLY_INTERVAL; 2058 } 2059 2060 /* trash the spare routes when they go bad */ 2061 if (rts->rts_metric < HOPCNT_INFINITY 2062 && now_garbage > rts->rts_time 2063 && i != NUM_SPARES) 2064 rts_delete(RT, rts); 2065 } 2066 2067 2068 /* finished if the active route is still fresh */ 2069 if (now_stale <= RT->rt_time) 2070 return 0; 2071 2072 /* try to switch to an alternative */ 2073 rtswitch(RT, 0); 2074 2075 /* Delete a dead route after it has been publically mourned. */ 2076 if (now_garbage > RT->rt_time) { 2077 rtdelete(RT); 2078 return 0; 2079 } 2080 2081 /* Start poisoning a bad route before deleting it. */ 2082 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) { 2083 struct rt_spare new = RT->rt_spares[0]; 2084 new.rts_metric = HOPCNT_INFINITY; 2085 rtchange(RT, RT->rt_state, &new, 0); 2086 } 2087 return 0; 2088 } 2089 2090 2091 /* Watch for dead routes and interfaces. 2092 */ 2093 void 2094 age(naddr bad_gate) 2095 { 2096 struct interface *ifp; 2097 int need_query = 0; 2098 2099 /* If not listening to RIP, there is no need to age the routes in 2100 * the table. 2101 */ 2102 age_timer.tv_sec = (now.tv_sec 2103 + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); 2104 2105 /* Check for dead IS_REMOTE interfaces by timing their 2106 * transmissions. 2107 */ 2108 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 2109 if (!(ifp->int_state & IS_REMOTE)) 2110 continue; 2111 2112 /* ignore unreachable remote interfaces */ 2113 if (!check_remote(ifp)) 2114 continue; 2115 2116 /* Restore remote interface that has become reachable 2117 */ 2118 if (ifp->int_state & IS_BROKE) 2119 if_ok(ifp, "remote "); 2120 2121 if (ifp->int_act_time != NEVER 2122 && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { 2123 msglog("remote interface %s to %s timed out after" 2124 " %ld:%ld", 2125 ifp->int_name, 2126 naddr_ntoa(ifp->int_dstaddr), 2127 (now.tv_sec - ifp->int_act_time)/60, 2128 (now.tv_sec - ifp->int_act_time)%60); 2129 if_sick(ifp); 2130 } 2131 2132 /* If we have not heard from the other router 2133 * recently, ask it. 2134 */ 2135 if (now.tv_sec >= ifp->int_query_time) { 2136 ifp->int_query_time = NEVER; 2137 need_query = 1; 2138 } 2139 } 2140 2141 /* Age routes. */ 2142 age_bad_gate = bad_gate; 2143 (void)rn_walktree(rhead, walk_age, 0); 2144 2145 /* delete old redirected routes to keep the kernel table small 2146 * and prevent blackholes 2147 */ 2148 del_redirects(bad_gate, now.tv_sec-STALE_TIME); 2149 2150 /* Update the kernel routing table. */ 2151 fix_kern(); 2152 2153 /* poke reticent remote gateways */ 2154 if (need_query) 2155 rip_query(); 2156 } 2157