sbin/routed/table.c

   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 1.2 2003/06/17 04:27:34 dillon 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                 (void)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         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         (void)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         (void)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((void**)&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         (void)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         (void)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 }