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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31
  32 #include "defs.h"
  33
  34 #ifdef __NetBSD__
  35 __RCSID("$NetBSD$");
  36 #elif defined(__FreeBSD__)
  37 __RCSID("$FreeBSD$");
  38 #else
  39 __RCSID("$Revision: 2.27 $");
  40 #ident "$Revision: 2.27 $"
  41 #endif
  42
  43 static struct rt_spare *rts_better(struct rt_entry *);
  44 static struct rt_spare rts_empty = {0,0,0,HOPCNT_INFINITY,0,0,0};
  45 static void  set_need_flash(void);
  46 #ifdef _HAVE_SIN_LEN
  47 static void masktrim(struct sockaddr_in *ap);
  48 #else
  49 static void masktrim(struct sockaddr_in_new *ap);
  50 #endif
  51 static void rtbad(struct rt_entry *);
  52
  53
  54 struct radix_node_head *rhead;          /* root of the radix tree */
  55
  56 int     need_flash = 1;                 /* flash update needed
  57                                          * start =1 to suppress the 1st
  58                                          */
  59
  60 struct timeval age_timer;               /* next check of old routes */
  61 struct timeval need_kern = {            /* need to update kernel table */
  62         EPOCH+MIN_WAITTIME-1, 0
  63 };
  64
  65 int     stopint;
  66
  67 int     total_routes;
  68
  69 /* zap any old routes through this gateway */
  70 static naddr age_bad_gate;
  71
  72
  73 /* It is desirable to "aggregate" routes, to combine differing routes of
  74  * the same metric and next hop into a common route with a smaller netmask
  75  * or to suppress redundant routes, routes that add no information to
  76  * routes with smaller netmasks.
  77  *
  78  * A route is redundant if and only if any and all routes with smaller
  79  * but matching netmasks and nets are the same.  Since routes are
  80  * kept sorted in the radix tree, redundant routes always come second.
  81  *
  82  * There are two kinds of aggregations.  First, two routes of the same bit
  83  * mask and differing only in the least significant bit of the network
  84  * number can be combined into a single route with a coarser mask.
  85  *
  86  * Second, a route can be suppressed in favor of another route with a more
  87  * coarse mask provided no incompatible routes with intermediate masks
  88  * are present.  The second kind of aggregation involves suppressing routes.
  89  * A route must not be suppressed if an incompatible route exists with
  90  * an intermediate mask, since the suppressed route would be covered
  91  * by the intermediate.
  92  *
  93  * This code relies on the radix tree walk encountering routes
  94  * sorted first by address, with the smallest address first.
  95  */
  96
  97 static struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest;
  98
  99 /* #define DEBUG_AG */
 100 #ifdef DEBUG_AG
 101 #define CHECK_AG() {int acnt = 0; struct ag_info *cag;          \
 102         for (cag = ag_avail; cag != 0; cag = cag->ag_fine)      \
 103                 acnt++;                                         \
 104         for (cag = ag_corsest; cag != 0; cag = cag->ag_fine)    \
 105                 acnt++;                                         \
 106         if (acnt != NUM_AG_SLOTS) {                             \
 107                 (void)fflush(stderr);                           \
 108                 abort();                                        \
 109         }                                                       \
 110 }
 111 #else
 112 #define CHECK_AG()
 113 #endif
 114
 115
 116 /* Output the contents of an aggregation table slot.
 117  *      This function must always be immediately followed with the deletion
 118  *      of the target slot.
 119  */
 120 static void
 121 ag_out(struct ag_info *ag,
 122          void (*out)(struct ag_info *))
 123 {
 124         struct ag_info *ag_cors;
 125         naddr bit;
 126
 127
 128         /* Forget it if this route should not be output for split-horizon. */
 129         if (ag->ag_state & AGS_SPLIT_HZ)
 130                 return;
 131
 132         /* If we output both the even and odd twins, then the immediate parent,
 133          * if it is present, is redundant, unless the parent manages to
 134          * aggregate into something coarser.
 135          * On successive calls, this code detects the even and odd twins,
 136          * and marks the parent.
 137          *
 138          * Note that the order in which the radix tree code emits routes
 139          * ensures that the twins are seen before the parent is emitted.
 140          */
 141         ag_cors = ag->ag_cors;
 142         if (ag_cors != 0
 143             && ag_cors->ag_mask == ag->ag_mask<<1
 144             && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) {
 145                 ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h)
 146                                       ? AGS_REDUN0
 147                                       : AGS_REDUN1);
 148         }
 149
 150         /* Skip it if this route is itself redundant.
 151          *
 152          * It is ok to change the contents of the slot here, since it is
 153          * always deleted next.
 154          */
 155         if (ag->ag_state & AGS_REDUN0) {
 156                 if (ag->ag_state & AGS_REDUN1)
 157                         return;         /* quit if fully redundant */
 158                 /* make it finer if it is half-redundant */
 159                 bit = (-ag->ag_mask) >> 1;
 160                 ag->ag_dst_h |= bit;
 161                 ag->ag_mask |= bit;
 162
 163         } else if (ag->ag_state & AGS_REDUN1) {
 164                 /* make it finer if it is half-redundant */
 165                 bit = (-ag->ag_mask) >> 1;
 166                 ag->ag_mask |= bit;
 167         }
 168         out(ag);
 169 }
 170
 171
 172 static void
 173 ag_del(struct ag_info *ag)
 174 {
 175         CHECK_AG();
 176
 177         if (ag->ag_cors == 0)
 178                 ag_corsest = ag->ag_fine;
 179         else
 180                 ag->ag_cors->ag_fine = ag->ag_fine;
 181
 182         if (ag->ag_fine == 0)
 183                 ag_finest = ag->ag_cors;
 184         else
 185                 ag->ag_fine->ag_cors = ag->ag_cors;
 186
 187         ag->ag_fine = ag_avail;
 188         ag_avail = ag;
 189
 190         CHECK_AG();
 191 }
 192
 193
 194 /* Flush routes waiting for aggregation.
 195  *      This must not suppress a route unless it is known that among all
 196  *      routes with coarser masks that match it, the one with the longest
 197  *      mask is appropriate.  This is ensured by scanning the routes
 198  *      in lexical order, and with the most restrictive mask first
 199  *      among routes to the same destination.
 200  */
 201 void
 202 ag_flush(naddr lim_dst_h,               /* flush routes to here */
 203          naddr lim_mask,                /* matching this mask */
 204          void (*out)(struct ag_info *))
 205 {
 206         struct ag_info *ag, *ag_cors;
 207         naddr dst_h;
 208
 209
 210         for (ag = ag_finest;
 211              ag != 0 && ag->ag_mask >= lim_mask;
 212              ag = ag_cors) {
 213                 ag_cors = ag->ag_cors;
 214
 215                 /* work on only the specified routes */
 216                 dst_h = ag->ag_dst_h;
 217                 if ((dst_h & lim_mask) != lim_dst_h)
 218                         continue;
 219
 220                 if (!(ag->ag_state & AGS_SUPPRESS))
 221                         ag_out(ag, out);
 222
 223                 else for ( ; ; ag_cors = ag_cors->ag_cors) {
 224                         /* Look for a route that can suppress the
 225                          * current route */
 226                         if (ag_cors == 0) {
 227                                 /* failed, so output it and look for
 228                                  * another route to work on
 229                                  */
 230                                 ag_out(ag, out);
 231                                 break;
 232                         }
 233
 234                         if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) {
 235                                 /* We found a route with a coarser mask that
 236                                  * aggregates the current target.
 237                                  *
 238                                  * If it has a different next hop, it
 239                                  * cannot replace the target, so output
 240                                  * the target.
 241                                  */
 242                                 if (ag->ag_gate != ag_cors->ag_gate
 243                                     && !(ag->ag_state & AGS_FINE_GATE)
 244                                     && !(ag_cors->ag_state & AGS_CORS_GATE)) {
 245                                         ag_out(ag, out);
 246                                         break;
 247                                 }
 248
 249                                 /* If the coarse route has a good enough
 250                                  * metric, it suppresses the target.
 251                                  * If the suppressed target was redundant,
 252                                  * then mark the suppressor redundant.
 253                                  */
 254                                 if (ag_cors->ag_pref <= ag->ag_pref) {
 255                                     if (AG_IS_REDUN(ag->ag_state)
 256                                         && ag_cors->ag_mask==ag->ag_mask<<1) {
 257                                         if (ag_cors->ag_dst_h == dst_h)
 258                                             ag_cors->ag_state |= AGS_REDUN0;
 259                                         else
 260                                             ag_cors->ag_state |= AGS_REDUN1;
 261                                     }
 262                                     if (ag->ag_tag != ag_cors->ag_tag)
 263                                             ag_cors->ag_tag = 0;
 264                                     if (ag->ag_nhop != ag_cors->ag_nhop)
 265                                             ag_cors->ag_nhop = 0;
 266                                     break;
 267                                 }
 268                         }
 269                 }
 270
 271                 /* That route has either been output or suppressed */
 272                 ag_cors = ag->ag_cors;
 273                 ag_del(ag);
 274         }
 275
 276         CHECK_AG();
 277 }
 278
 279
 280 /* Try to aggregate a route with previous routes.
 281  */
 282 void
 283 ag_check(naddr  dst,
 284          naddr  mask,
 285          naddr  gate,
 286          naddr  nhop,
 287          char   metric,
 288          char   pref,
 289          u_int  new_seqno,
 290          u_short tag,
 291          u_short state,
 292          void (*out)(struct ag_info *)) /* output using this */
 293 {
 294         struct ag_info *ag, *nag, *ag_cors;
 295         naddr xaddr;
 296         int x;
 297
 298         dst = ntohl(dst);
 299
 300         /* Punt non-contiguous subnet masks.
 301          *
 302          * (X & -X) contains a single bit if and only if X is a power of 2.
 303          * (X + (X & -X)) == 0 if and only if X is a power of 2.
 304          */
 305         if ((mask & -mask) + mask != 0) {
 306                 struct ag_info nc_ag;
 307
 308                 nc_ag.ag_dst_h = dst;
 309                 nc_ag.ag_mask = mask;
 310                 nc_ag.ag_gate = gate;
 311                 nc_ag.ag_nhop = nhop;
 312                 nc_ag.ag_metric = metric;
 313                 nc_ag.ag_pref = pref;
 314                 nc_ag.ag_tag = tag;
 315                 nc_ag.ag_state = state;
 316                 nc_ag.ag_seqno = new_seqno;
 317                 out(&nc_ag);
 318                 return;
 319         }
 320
 321         /* Search for the right slot in the aggregation table.
 322          */
 323         ag_cors = 0;
 324         ag = ag_corsest;
 325         while (ag != 0) {
 326                 if (ag->ag_mask >= mask)
 327                         break;
 328
 329                 /* Suppress old routes (i.e. combine with compatible routes
 330                  * with coarser masks) as we look for the right slot in the
 331                  * aggregation table for the new route.
 332                  * A route to an address less than the current destination
 333                  * will not be affected by the current route or any route
 334                  * seen hereafter.  That means it is safe to suppress it.
 335                  * This check keeps poor routes (e.g. with large hop counts)
 336                  * from preventing suppression of finer routes.
 337                  */
 338                 if (ag_cors != 0
 339                     && ag->ag_dst_h < dst
 340                     && (ag->ag_state & AGS_SUPPRESS)
 341                     && ag_cors->ag_pref <= ag->ag_pref
 342                     && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h
 343                     && (ag_cors->ag_gate == ag->ag_gate
 344                         || (ag->ag_state & AGS_FINE_GATE)
 345                         || (ag_cors->ag_state & AGS_CORS_GATE))) {
 346                         /*  If the suppressed target was redundant,
 347                          * then mark the suppressor redundant.
 348                          */
 349                         if (AG_IS_REDUN(ag->ag_state)
 350                             && ag_cors->ag_mask == ag->ag_mask<<1) {
 351                                 if (ag_cors->ag_dst_h == dst)
 352                                         ag_cors->ag_state |= AGS_REDUN0;
 353                                 else
 354                                         ag_cors->ag_state |= AGS_REDUN1;
 355                         }
 356                         if (ag->ag_tag != ag_cors->ag_tag)
 357                                 ag_cors->ag_tag = 0;
 358                         if (ag->ag_nhop != ag_cors->ag_nhop)
 359                                 ag_cors->ag_nhop = 0;
 360                         ag_del(ag);
 361                         CHECK_AG();
 362                 } else {
 363                         ag_cors = ag;
 364                 }
 365                 ag = ag_cors->ag_fine;
 366         }
 367
 368         /* If we find the even/odd twin of the new route, and if the
 369          * masks and so forth are equal, we can aggregate them.
 370          * We can probably promote one of the pair.
 371          *
 372          * Since the routes are encountered in lexical order,
 373          * the new route must be odd.  However, the second or later
 374          * times around this loop, it could be the even twin promoted
 375          * from the even/odd pair of twins of the finer route.
 376          */
 377         while (ag != 0
 378                && ag->ag_mask == mask
 379                && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) {
 380
 381                 /* Here we know the target route and the route in the current
 382                  * slot have the same netmasks and differ by at most the
 383                  * last bit.  They are either for the same destination, or
 384                  * for an even/odd pair of destinations.
 385                  */
 386                 if (ag->ag_dst_h == dst) {
 387                         /* We have two routes to the same destination.
 388                          * Routes are encountered in lexical order, so a
 389                          * route is never promoted until the parent route is
 390                          * already present.  So we know that the new route is
 391                          * a promoted (or aggregated) pair and the route
 392                          * already in the slot is the explicit route.
 393                          *
 394                          * Prefer the best route if their metrics differ,
 395                          * or the aggregated one if not, following a sort
 396                          * of longest-match rule.
 397                          */
 398                         if (pref <= ag->ag_pref) {
 399                                 ag->ag_gate = gate;
 400                                 ag->ag_nhop = nhop;
 401                                 ag->ag_tag = tag;
 402                                 ag->ag_metric = metric;
 403                                 ag->ag_pref = pref;
 404                                 if (ag->ag_seqno < new_seqno)
 405                                         ag->ag_seqno = new_seqno;
 406                                 x = ag->ag_state;
 407                                 ag->ag_state = state;
 408                                 state = x;
 409                         }
 410
 411                         /* Some bits are set if they are set on either route,
 412                          * except when the route is for an interface.
 413                          */
 414                         if (!(ag->ag_state & AGS_IF))
 415                                 ag->ag_state |= (state & (AGS_AGGREGATE_EITHER
 416                                                         | AGS_REDUN0
 417                                                         | AGS_REDUN1));
 418                         return;
 419                 }
 420
 421                 /* If one of the routes can be promoted and the other can
 422                  * be suppressed, it may be possible to combine them or
 423                  * worthwhile to promote one.
 424                  *
 425                  * Any route that can be promoted is always
 426                  * marked to be eligible to be suppressed.
 427                  */
 428                 if (!((state & AGS_AGGREGATE)
 429                       && (ag->ag_state & AGS_SUPPRESS))
 430                     && !((ag->ag_state & AGS_AGGREGATE)
 431                          && (state & AGS_SUPPRESS)))
 432                         break;
 433
 434                 /* A pair of even/odd twin routes can be combined
 435                  * if either is redundant, or if they are via the
 436                  * same gateway and have the same metric.
 437                  */
 438                 if (AG_IS_REDUN(ag->ag_state)
 439                     || AG_IS_REDUN(state)
 440                     || (ag->ag_gate == gate
 441                         && ag->ag_pref == pref
 442                         && (state & ag->ag_state & AGS_AGGREGATE) != 0)) {
 443
 444                         /* We have both the even and odd pairs.
 445                          * Since the routes are encountered in order,
 446                          * the route in the slot must be the even twin.
 447                          *
 448                          * Combine and promote (aggregate) the pair of routes.
 449                          */
 450                         if (new_seqno < ag->ag_seqno)
 451                                 new_seqno = ag->ag_seqno;
 452                         if (!AG_IS_REDUN(state))
 453                                 state &= ~AGS_REDUN1;
 454                         if (AG_IS_REDUN(ag->ag_state))
 455                                 state |= AGS_REDUN0;
 456                         else
 457                                 state &= ~AGS_REDUN0;
 458                         state |= (ag->ag_state & AGS_AGGREGATE_EITHER);
 459                         if (ag->ag_tag != tag)
 460                                 tag = 0;
 461                         if (ag->ag_nhop != nhop)
 462                                 nhop = 0;
 463
 464                         /* Get rid of the even twin that was already
 465                          * in the slot.
 466                          */
 467                         ag_del(ag);
 468
 469                 } else if (ag->ag_pref >= pref
 470                            && (ag->ag_state & AGS_AGGREGATE)) {
 471                         /* If we cannot combine the pair, maybe the route
 472                          * with the worse metric can be promoted.
 473                          *
 474                          * Promote the old, even twin, by giving its slot
 475                          * in the table to the new, odd twin.
 476                          */
 477                         ag->ag_dst_h = dst;
 478
 479                         xaddr = ag->ag_gate;
 480                         ag->ag_gate = gate;
 481                         gate = xaddr;
 482
 483                         xaddr = ag->ag_nhop;
 484                         ag->ag_nhop = nhop;
 485                         nhop = xaddr;
 486
 487                         x = ag->ag_tag;
 488                         ag->ag_tag = tag;
 489                         tag = x;
 490
 491                         /* The promoted route is even-redundant only if the
 492                          * even twin was fully redundant.  It is not
 493                          * odd-redundant because the odd-twin will still be
 494                          * in the table.
 495                          */
 496                         x = ag->ag_state;
 497                         if (!AG_IS_REDUN(x))
 498                                 x &= ~AGS_REDUN0;
 499                         x &= ~AGS_REDUN1;
 500                         ag->ag_state = state;
 501                         state = x;
 502
 503                         x = ag->ag_metric;
 504                         ag->ag_metric = metric;
 505                         metric = x;
 506
 507                         x = ag->ag_pref;
 508                         ag->ag_pref = pref;
 509                         pref = x;
 510
 511                         /* take the newest sequence number */
 512                         if (new_seqno <= ag->ag_seqno)
 513                                 new_seqno = ag->ag_seqno;
 514                         else
 515                                 ag->ag_seqno = new_seqno;
 516
 517                 } else {
 518                         if (!(state & AGS_AGGREGATE))
 519                                 break;  /* cannot promote either twin */
 520
 521                         /* Promote the new, odd twin by shaving its
 522                          * mask and address.
 523                          * The promoted route is odd-redundant only if the
 524                          * odd twin was fully redundant.  It is not
 525                          * even-redundant because the even twin is still in
 526                          * the table.
 527                          */
 528                         if (!AG_IS_REDUN(state))
 529                                 state &= ~AGS_REDUN1;
 530                         state &= ~AGS_REDUN0;
 531                         if (new_seqno < ag->ag_seqno)
 532                                 new_seqno = ag->ag_seqno;
 533                         else
 534                                 ag->ag_seqno = new_seqno;
 535                 }
 536
 537                 mask <<= 1;
 538                 dst &= mask;
 539
 540                 if (ag_cors == 0) {
 541                         ag = ag_corsest;
 542                         break;
 543                 }
 544                 ag = ag_cors;
 545                 ag_cors = ag->ag_cors;
 546         }
 547
 548         /* When we can no longer promote and combine routes,
 549          * flush the old route in the target slot.  Also flush
 550          * any finer routes that we know will never be aggregated by
 551          * the new route.
 552          *
 553          * In case we moved toward coarser masks,
 554          * get back where we belong
 555          */
 556         if (ag != 0
 557             && ag->ag_mask < mask) {
 558                 ag_cors = ag;
 559                 ag = ag->ag_fine;
 560         }
 561
 562         /* Empty the target slot
 563          */
 564         if (ag != 0 && ag->ag_mask == mask) {
 565                 ag_flush(ag->ag_dst_h, ag->ag_mask, out);
 566                 ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine;
 567         }
 568
 569 #ifdef DEBUG_AG
 570         (void)fflush(stderr);
 571         if (ag == 0 && ag_cors != ag_finest)
 572                 abort();
 573         if (ag_cors == 0 && ag != ag_corsest)
 574                 abort();
 575         if (ag != 0 && ag->ag_cors != ag_cors)
 576                 abort();
 577         if (ag_cors != 0 && ag_cors->ag_fine != ag)
 578                 abort();
 579         CHECK_AG();
 580 #endif
 581
 582         /* Save the new route on the end of the table.
 583          */
 584         nag = ag_avail;
 585         ag_avail = nag->ag_fine;
 586
 587         nag->ag_dst_h = dst;
 588         nag->ag_mask = mask;
 589         nag->ag_gate = gate;
 590         nag->ag_nhop = nhop;
 591         nag->ag_metric = metric;
 592         nag->ag_pref = pref;
 593         nag->ag_tag = tag;
 594         nag->ag_state = state;
 595         nag->ag_seqno = new_seqno;
 596
 597         nag->ag_fine = ag;
 598         if (ag != 0)
 599                 ag->ag_cors = nag;
 600         else
 601                 ag_finest = nag;
 602         nag->ag_cors = ag_cors;
 603         if (ag_cors == 0)
 604                 ag_corsest = nag;
 605         else
 606                 ag_cors->ag_fine = nag;
 607         CHECK_AG();
 608 }
 609
 610 static const char *
 611 rtm_type_name(u_char type)
 612 {
 613         static const char * const rtm_types[] = {
 614                 "RTM_ADD",
 615                 "RTM_DELETE",
 616                 "RTM_CHANGE",
 617                 "RTM_GET",
 618                 "RTM_LOSING",
 619                 "RTM_REDIRECT",
 620                 "RTM_MISS",
 621                 "RTM_LOCK",
 622                 "RTM_OLDADD",
 623                 "RTM_OLDDEL",
 624                 "RTM_RESOLVE",
 625                 "RTM_NEWADDR",
 626                 "RTM_DELADDR",
 627 #ifdef RTM_OIFINFO
 628                 "RTM_OIFINFO",
 629 #endif
 630                 "RTM_IFINFO",
 631                 "RTM_NEWMADDR",
 632                 "RTM_DELMADDR"
 633         };
 634 #define NEW_RTM_PAT "RTM type %#x"
 635         static char name0[sizeof(NEW_RTM_PAT)+2];
 636
 637
 638         if (type > sizeof(rtm_types)/sizeof(rtm_types[0])
 639             || type == 0) {
 640                 snprintf(name0, sizeof(name0), NEW_RTM_PAT, type);
 641                 return name0;
 642         } else {
 643                 return rtm_types[type-1];
 644         }
 645 #undef NEW_RTM_PAT
 646 }
 647
 648
 649 /* Trim a mask in a sockaddr
 650  *      Produce a length of 0 for an address of 0.
 651  *      Otherwise produce the index of the first zero byte.
 652  */
 653 void
 654 #ifdef _HAVE_SIN_LEN
 655 masktrim(struct sockaddr_in *ap)
 656 #else
 657 masktrim(struct sockaddr_in_new *ap)
 658 #endif
 659 {
 660         char *cp;
 661
 662         if (ap->sin_addr.s_addr == 0) {
 663                 ap->sin_len = 0;
 664                 return;
 665         }
 666         cp = (char *)(&ap->sin_addr.s_addr+1);
 667         while (*--cp == 0)
 668                 continue;
 669         ap->sin_len = cp - (char*)ap + 1;
 670 }
 671
 672
 673 /* Tell the kernel to add, delete or change a route
 674  */
 675 static void
 676 rtioctl(int action,                     /* RTM_DELETE, etc */
 677         naddr dst,
 678         naddr gate,
 679         naddr mask,
 680         int metric,
 681         int flags)
 682 {
 683         struct {
 684                 struct rt_msghdr w_rtm;
 685                 struct sockaddr_in w_dst;
 686                 struct sockaddr_in w_gate;
 687 #ifdef _HAVE_SA_LEN
 688                 struct sockaddr_in w_mask;
 689 #else
 690                 struct sockaddr_in_new w_mask;
 691 #endif
 692         } w;
 693         long cc;
 694 #   define PAT " %-10s %s metric=%d flags=%#x"
 695 #   define ARGS rtm_type_name(action), rtname(dst,mask,gate), metric, flags
 696
 697 again:
 698         memset(&w, 0, sizeof(w));
 699         w.w_rtm.rtm_msglen = sizeof(w);
 700         w.w_rtm.rtm_version = RTM_VERSION;
 701         w.w_rtm.rtm_type = action;
 702         w.w_rtm.rtm_flags = flags;
 703         w.w_rtm.rtm_seq = ++rt_sock_seqno;
 704         w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY;
 705         if (metric != 0 || action == RTM_CHANGE) {
 706                 w.w_rtm.rtm_rmx.rmx_hopcount = metric;
 707                 w.w_rtm.rtm_inits |= RTV_HOPCOUNT;
 708         }
 709         w.w_dst.sin_family = AF_INET;
 710         w.w_dst.sin_addr.s_addr = dst;
 711         w.w_gate.sin_family = AF_INET;
 712         w.w_gate.sin_addr.s_addr = gate;
 713 #ifdef _HAVE_SA_LEN
 714         w.w_dst.sin_len = sizeof(w.w_dst);
 715         w.w_gate.sin_len = sizeof(w.w_gate);
 716 #endif
 717         if (mask == HOST_MASK) {
 718                 w.w_rtm.rtm_flags |= RTF_HOST;
 719                 w.w_rtm.rtm_msglen -= sizeof(w.w_mask);
 720         } else {
 721                 w.w_rtm.rtm_addrs |= RTA_NETMASK;
 722                 w.w_mask.sin_addr.s_addr = htonl(mask);
 723 #ifdef _HAVE_SA_LEN
 724                 masktrim(&w.w_mask);
 725                 if (w.w_mask.sin_len == 0)
 726                         w.w_mask.sin_len = sizeof(long);
 727                 w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len);
 728 #endif
 729         }
 730
 731 #ifndef NO_INSTALL
 732         cc = write(rt_sock, &w, w.w_rtm.rtm_msglen);
 733         if (cc < 0) {
 734                 if (errno == ESRCH
 735                     && (action == RTM_CHANGE || action == RTM_DELETE)) {
 736                         trace_act("route disappeared before" PAT, ARGS);
 737                         if (action == RTM_CHANGE) {
 738                                 action = RTM_ADD;
 739                                 goto again;
 740                         }
 741                         return;
 742                 }
 743                 msglog("write(rt_sock)" PAT ": %s", ARGS, strerror(errno));
 744                 return;
 745         } else if (cc != w.w_rtm.rtm_msglen) {
 746                 msglog("write(rt_sock) wrote %ld instead of %d for" PAT,
 747                        cc, w.w_rtm.rtm_msglen, ARGS);
 748                 return;
 749         }
 750 #endif
 751         if (TRACEKERNEL)
 752                 trace_misc("write kernel" PAT, ARGS);
 753 #undef PAT
 754 #undef ARGS
 755 }
 756
 757
 758 #define KHASH_SIZE 71                   /* should be prime */
 759 #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE]
 760 static struct khash {
 761         struct khash *k_next;
 762         naddr   k_dst;
 763         naddr   k_mask;
 764         naddr   k_gate;
 765         short   k_metric;
 766         u_short k_state;
 767 #define     KS_NEW      0x001
 768 #define     KS_DELETE   0x002           /* need to delete the route */
 769 #define     KS_ADD      0x004           /* add to the kernel */
 770 #define     KS_CHANGE   0x008           /* tell kernel to change the route */
 771 #define     KS_DEL_ADD  0x010           /* delete & add to change the kernel */
 772 #define     KS_STATIC   0x020           /* Static flag in kernel */
 773 #define     KS_GATEWAY  0x040           /* G flag in kernel */
 774 #define     KS_DYNAMIC  0x080           /* result of redirect */
 775 #define     KS_DELETED  0x100           /* already deleted from kernel */
 776 #define     KS_CHECK    0x200
 777         time_t  k_keep;
 778 #define     K_KEEP_LIM  30
 779         time_t  k_redirect_time;        /* when redirected route 1st seen */
 780 } *khash_bins[KHASH_SIZE];
 781
 782
 783 static struct khash*
 784 kern_find(naddr dst, naddr mask, struct khash ***ppk)
 785 {
 786         struct khash *k, **pk;
 787
 788         for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) {
 789                 if (k->k_dst == dst && k->k_mask == mask)
 790                         break;
 791         }
 792         if (ppk != 0)
 793                 *ppk = pk;
 794         return k;
 795 }
 796
 797
 798 static struct khash*
 799 kern_add(naddr dst, naddr mask)
 800 {
 801         struct khash *k, **pk;
 802
 803         k = kern_find(dst, mask, &pk);
 804         if (k != 0)
 805                 return k;
 806
 807         k = (struct khash *)rtmalloc(sizeof(*k), "kern_add");
 808
 809         memset(k, 0, sizeof(*k));
 810         k->k_dst = dst;
 811         k->k_mask = mask;
 812         k->k_state = KS_NEW;
 813         k->k_keep = now.tv_sec;
 814         *pk = k;
 815
 816         return k;
 817 }
 818
 819
 820 /* If a kernel route has a non-zero metric, check that it is still in the
 821  *      daemon table, and not deleted by interfaces coming and going.
 822  */
 823 static void
 824 kern_check_static(struct khash *k,
 825                   struct interface *ifp)
 826 {
 827         struct rt_entry *rt;
 828         struct rt_spare new;
 829
 830         if (k->k_metric == 0)
 831                 return;
 832
 833         memset(&new, 0, sizeof(new));
 834         new.rts_ifp = ifp;
 835         new.rts_gate = k->k_gate;
 836         new.rts_router = (ifp != 0) ? ifp->int_addr : loopaddr;
 837         new.rts_metric = k->k_metric;
 838         new.rts_time = now.tv_sec;
 839
 840         rt = rtget(k->k_dst, k->k_mask);
 841         if (rt != 0) {
 842                 if (!(rt->rt_state & RS_STATIC))
 843                         rtchange(rt, rt->rt_state | RS_STATIC, &new, 0);
 844         } else {
 845                 rtadd(k->k_dst, k->k_mask, RS_STATIC, &new);
 846         }
 847 }
 848
 849
 850 /* operate on a kernel entry
 851  */
 852 static void
 853 kern_ioctl(struct khash *k,
 854            int action,                  /* RTM_DELETE, etc */
 855            int flags)
 856
 857 {
 858         switch (action) {
 859         case RTM_DELETE:
 860                 k->k_state &= ~KS_DYNAMIC;
 861                 if (k->k_state & KS_DELETED)
 862                         return;
 863                 k->k_state |= KS_DELETED;
 864                 break;
 865         case RTM_ADD:
 866                 k->k_state &= ~KS_DELETED;
 867                 break;
 868         case RTM_CHANGE:
 869                 if (k->k_state & KS_DELETED) {
 870                         action = RTM_ADD;
 871                         k->k_state &= ~KS_DELETED;
 872                 }
 873                 break;
 874         }
 875
 876         rtioctl(action, k->k_dst, k->k_gate, k->k_mask, k->k_metric, flags);
 877 }
 878
 879
 880 /* add a route the kernel told us
 881  */
 882 static void
 883 rtm_add(struct rt_msghdr *rtm,
 884         struct rt_addrinfo *info,
 885         time_t keep)
 886 {
 887         struct khash *k;
 888         struct interface *ifp;
 889         naddr mask;
 890
 891
 892         if (rtm->rtm_flags & RTF_HOST) {
 893                 mask = HOST_MASK;
 894         } else if (INFO_MASK(info) != 0) {
 895                 mask = ntohl(S_ADDR(INFO_MASK(info)));
 896         } else {
 897                 msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type));
 898                 return;
 899         }
 900
 901         k = kern_add(S_ADDR(INFO_DST(info)), mask);
 902         if (k->k_state & KS_NEW)
 903                 k->k_keep = now.tv_sec+keep;
 904         if (INFO_GATE(info) == 0) {
 905                 trace_act("note %s without gateway",
 906                           rtm_type_name(rtm->rtm_type));
 907                 k->k_metric = HOPCNT_INFINITY;
 908         } else if (INFO_GATE(info)->sa_family != AF_INET) {
 909                 trace_act("note %s with gateway AF=%d",
 910                           rtm_type_name(rtm->rtm_type),
 911                           INFO_GATE(info)->sa_family);
 912                 k->k_metric = HOPCNT_INFINITY;
 913         } else {
 914                 k->k_gate = S_ADDR(INFO_GATE(info));
 915                 k->k_metric = rtm->rtm_rmx.rmx_hopcount;
 916                 if (k->k_metric < 0)
 917                         k->k_metric = 0;
 918                 else if (k->k_metric > HOPCNT_INFINITY-1)
 919                         k->k_metric = HOPCNT_INFINITY-1;
 920         }
 921         k->k_state &= ~(KS_DELETE | KS_ADD | KS_CHANGE | KS_DEL_ADD
 922                         | KS_DELETED | KS_GATEWAY | KS_STATIC
 923                         | KS_NEW | KS_CHECK);
 924         if (rtm->rtm_flags & RTF_GATEWAY)
 925                 k->k_state |= KS_GATEWAY;
 926         if (rtm->rtm_flags & RTF_STATIC)
 927                 k->k_state |= KS_STATIC;
 928
 929         if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) {
 930                 if (INFO_AUTHOR(info) != 0
 931                     && INFO_AUTHOR(info)->sa_family == AF_INET)
 932                         ifp = iflookup(S_ADDR(INFO_AUTHOR(info)));
 933                 else
 934                         ifp = 0;
 935                 if (supplier
 936                     && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) {
 937                         /* Routers are not supposed to listen to redirects,
 938                          * so delete it if it came via an unknown interface
 939                          * or the interface does not have special permission.
 940                          */
 941                         k->k_state &= ~KS_DYNAMIC;
 942                         k->k_state |= KS_DELETE;
 943                         LIM_SEC(need_kern, 0);
 944                         trace_act("mark for deletion redirected %s --> %s"
 945                                   " via %s",
 946                                   addrname(k->k_dst, k->k_mask, 0),
 947                                   naddr_ntoa(k->k_gate),
 948                                   ifp ? ifp->int_name : "unknown interface");
 949                 } else {
 950                         k->k_state |= KS_DYNAMIC;
 951                         k->k_redirect_time = now.tv_sec;
 952                         trace_act("accept redirected %s --> %s via %s",
 953                                   addrname(k->k_dst, k->k_mask, 0),
 954                                   naddr_ntoa(k->k_gate),
 955                                   ifp ? ifp->int_name : "unknown interface");
 956                 }
 957                 return;
 958         }
 959
 960         /* If it is not a static route, quit until the next comparison
 961          * between the kernel and daemon tables, when it will be deleted.
 962          */
 963         if (!(k->k_state & KS_STATIC)) {
 964                 k->k_state |= KS_DELETE;
 965                 LIM_SEC(need_kern, k->k_keep);
 966                 return;
 967         }
 968
 969         /* Put static routes with real metrics into the daemon table so
 970          * they can be advertised.
 971          *
 972          * Find the interface toward the gateway.
 973          */
 974         ifp = iflookup(k->k_gate);
 975         if (ifp == 0)
 976                 msglog("static route %s --> %s impossibly lacks ifp",
 977                        addrname(S_ADDR(INFO_DST(info)), mask, 0),
 978                        naddr_ntoa(k->k_gate));
 979
 980         kern_check_static(k, ifp);
 981 }
 982
 983
 984 /* deal with packet loss
 985  */
 986 static void
 987 rtm_lose(struct rt_msghdr *rtm,
 988          struct rt_addrinfo *info)
 989 {
 990         if (INFO_GATE(info) == 0
 991             || INFO_GATE(info)->sa_family != AF_INET) {
 992                 trace_act("ignore %s without gateway",
 993                           rtm_type_name(rtm->rtm_type));
 994                 return;
 995         }
 996
 997         if (rdisc_ok)
 998                 rdisc_age(S_ADDR(INFO_GATE(info)));
 999         age(S_ADDR(INFO_GATE(info)));
1000 }
1001
1002
1003 /* Make the gateway slot of an info structure point to something
1004  * useful.  If it is not already useful, but it specifies an interface,
1005  * then fill in the sockaddr_in provided and point it there.
1006  */
1007 static int
1008 get_info_gate(struct sockaddr **sap,
1009               struct sockaddr_in *rsin)
1010 {
1011         struct sockaddr_dl *sdl = (struct sockaddr_dl *)*sap;
1012         struct interface *ifp;
1013
1014         if (sdl == 0)
1015                 return 0;
1016         if ((sdl)->sdl_family == AF_INET)
1017                 return 1;
1018         if ((sdl)->sdl_family != AF_LINK)
1019                 return 0;
1020
1021         ifp = ifwithindex(sdl->sdl_index, 1);
1022         if (ifp == 0)
1023                 return 0;
1024
1025         rsin->sin_addr.s_addr = ifp->int_addr;
1026 #ifdef _HAVE_SA_LEN
1027         rsin->sin_len = sizeof(*rsin);
1028 #endif
1029         rsin->sin_family = AF_INET;
1030         *sap = (struct sockaddr*)rsin;
1031
1032         return 1;
1033 }
1034
1035
1036 /* Clean the kernel table by copying it to the daemon image.
1037  * Eventually the daemon will delete any extra routes.
1038  */
1039 void
1040 flush_kern(void)
1041 {
1042         static char *sysctl_buf;
1043         static size_t sysctl_buf_size = 0;
1044         size_t needed;
1045         int mib[6];
1046         char *next, *lim;
1047         struct rt_msghdr *rtm;
1048         struct sockaddr_in gate_sin;
1049         struct rt_addrinfo info;
1050         int i;
1051         struct khash *k;
1052
1053
1054         for (i = 0; i < KHASH_SIZE; i++) {
1055                 for (k = khash_bins[i]; k != 0; k = k->k_next) {
1056                         k->k_state |= KS_CHECK;
1057                 }
1058         }
1059
1060         mib[0] = CTL_NET;
1061         mib[1] = PF_ROUTE;
1062         mib[2] = 0;             /* protocol */
1063         mib[3] = 0;             /* wildcard address family */
1064         mib[4] = NET_RT_DUMP;
1065         mib[5] = 0;             /* no flags */
1066         for (;;) {
1067                 if ((needed = sysctl_buf_size) != 0) {
1068                         if (sysctl(mib, 6, sysctl_buf,&needed, 0, 0) >= 0)
1069                                 break;
1070                         if (errno != ENOMEM && errno != EFAULT)
1071                                 BADERR(1,"flush_kern: sysctl(RT_DUMP)");
1072                         free(sysctl_buf);
1073                         needed = 0;
1074                 }
1075                 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0)
1076                         BADERR(1,"flush_kern: sysctl(RT_DUMP) estimate");
1077                 /* Kludge around the habit of some systems, such as
1078                  * BSD/OS 3.1, to not admit how many routes are in the
1079                  * kernel, or at least to be quite wrong.
1080                  */
1081                 needed += 50*(sizeof(*rtm)+5*sizeof(struct sockaddr));
1082                 sysctl_buf = rtmalloc(sysctl_buf_size = needed,
1083                                       "flush_kern sysctl(RT_DUMP)");
1084         }
1085
1086         lim = sysctl_buf + needed;
1087         for (next = sysctl_buf; next < lim; next += rtm->rtm_msglen) {
1088                 rtm = (struct rt_msghdr *)next;
1089                 if (rtm->rtm_msglen == 0) {
1090                         msglog("zero length kernel route at "
1091                                " %#lx in buffer %#lx before %#lx",
1092                                (u_long)rtm, (u_long)sysctl_buf, (u_long)lim);
1093                         break;
1094                 }
1095
1096                 rt_xaddrs(&info,
1097                           (struct sockaddr *)(rtm+1),
1098                           (struct sockaddr *)(next + rtm->rtm_msglen),
1099                           rtm->rtm_addrs);
1100
1101                 if (INFO_DST(&info) == 0
1102                     || INFO_DST(&info)->sa_family != AF_INET)
1103                         continue;
1104
1105 #if defined (RTF_LLINFO)
1106                 /* ignore ARP table entries on systems with a merged route
1107                  * and ARP table.
1108                  */
1109                 if (rtm->rtm_flags & RTF_LLINFO)
1110                         continue;
1111 #endif
1112 #if defined(RTF_WASCLONED) && defined(__FreeBSD__)
1113                 /* ignore cloned routes
1114                  */
1115                 if (rtm->rtm_flags & RTF_WASCLONED)
1116                         continue;
1117 #endif
1118
1119                 /* ignore multicast addresses
1120                  */
1121                 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info)))))
1122                         continue;
1123
1124                 if (!get_info_gate(&INFO_GATE(&info), &gate_sin))
1125                         continue;
1126
1127                 /* Note static routes and interface routes, and also
1128                  * preload the image of the kernel table so that
1129                  * we can later clean it, as well as avoid making
1130                  * unneeded changes.  Keep the old kernel routes for a
1131                  * few seconds to allow a RIP or router-discovery
1132                  * response to be heard.
1133                  */
1134                 rtm_add(rtm,&info,MIN_WAITTIME);
1135         }
1136
1137         for (i = 0; i < KHASH_SIZE; i++) {
1138                 for (k = khash_bins[i]; k != 0; k = k->k_next) {
1139                         if (k->k_state & KS_CHECK) {
1140                                 msglog("%s --> %s disappeared from kernel",
1141                                        addrname(k->k_dst, k->k_mask, 0),
1142                                        naddr_ntoa(k->k_gate));
1143                                 del_static(k->k_dst, k->k_mask, k->k_gate, 1);
1144                         }
1145                 }
1146         }
1147 }
1148
1149
1150 /* Listen to announcements from the kernel
1151  */
1152 void
1153 read_rt(void)
1154 {
1155         long cc;
1156         struct interface *ifp;
1157         struct sockaddr_in gate_sin;
1158         naddr mask, gate;
1159         union {
1160                 struct {
1161                         struct rt_msghdr rtm;
1162                         struct sockaddr addrs[RTAX_MAX];
1163                 } r;
1164                 struct if_msghdr ifm;
1165         } m;
1166         char str[100], *strp;
1167         struct rt_addrinfo info;
1168
1169
1170         for (;;) {
1171                 cc = read(rt_sock, &m, sizeof(m));
1172                 if (cc <= 0) {
1173                         if (cc < 0 && errno != EWOULDBLOCK)
1174                                 LOGERR("read(rt_sock)");
1175                         return;
1176                 }
1177
1178                 if (m.r.rtm.rtm_version != RTM_VERSION) {
1179                         msglog("bogus routing message version %d",
1180                                m.r.rtm.rtm_version);
1181                         continue;
1182                 }
1183
1184                 /* Ignore our own results.
1185                  */
1186                 if (m.r.rtm.rtm_type <= RTM_CHANGE
1187                     && m.r.rtm.rtm_pid == mypid) {
1188                         static int complained = 0;
1189                         if (!complained) {
1190                                 msglog("receiving our own change messages");
1191                                 complained = 1;
1192                         }
1193                         continue;
1194                 }
1195
1196                 if (m.r.rtm.rtm_type == RTM_IFINFO
1197                     || m.r.rtm.rtm_type == RTM_NEWADDR
1198                     || m.r.rtm.rtm_type == RTM_DELADDR) {
1199                         ifp = ifwithindex(m.ifm.ifm_index,
1200                                           m.r.rtm.rtm_type != RTM_DELADDR);
1201                         if (ifp == 0)
1202                                 trace_act("note %s with flags %#x"
1203                                           " for unknown interface index #%d",
1204                                           rtm_type_name(m.r.rtm.rtm_type),
1205                                           m.ifm.ifm_flags,
1206                                           m.ifm.ifm_index);
1207                         else
1208                                 trace_act("note %s with flags %#x for %s",
1209                                           rtm_type_name(m.r.rtm.rtm_type),
1210                                           m.ifm.ifm_flags,
1211                                           ifp->int_name);
1212
1213                         /* After being informed of a change to an interface,
1214                          * check them all now if the check would otherwise
1215                          * be a long time from now, if the interface is
1216                          * not known, or if the interface has been turned
1217                          * off or on.
1218                          */
1219                         if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL
1220                             || ifp == 0
1221                             || ((ifp->int_if_flags ^ m.ifm.ifm_flags)
1222                                 & IFF_UP) != 0)
1223                                 ifinit_timer.tv_sec = now.tv_sec;
1224                         continue;
1225                 }
1226 #ifdef RTM_OIFINFO
1227                 if (m.r.rtm.rtm_type == RTM_OIFINFO)
1228                         continue;       /* ignore compat message */
1229 #endif
1230
1231                 strcpy(str, rtm_type_name(m.r.rtm.rtm_type));
1232                 strp = &str[strlen(str)];
1233                 if (m.r.rtm.rtm_type <= RTM_CHANGE)
1234                         strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid);
1235
1236                 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX],
1237                           m.r.rtm.rtm_addrs);
1238
1239                 if (INFO_DST(&info) == 0) {
1240                         trace_act("ignore %s without dst", str);
1241                         continue;
1242                 }
1243
1244                 if (INFO_DST(&info)->sa_family != AF_INET) {
1245                         trace_act("ignore %s for AF %d", str,
1246                                   INFO_DST(&info)->sa_family);
1247                         continue;
1248                 }
1249
1250                 mask = ((INFO_MASK(&info) != 0)
1251                         ? ntohl(S_ADDR(INFO_MASK(&info)))
1252                         : (m.r.rtm.rtm_flags & RTF_HOST)
1253                         ? HOST_MASK
1254                         : std_mask(S_ADDR(INFO_DST(&info))));
1255
1256                 strp += sprintf(strp, ": %s",
1257                                 addrname(S_ADDR(INFO_DST(&info)), mask, 0));
1258
1259                 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) {
1260                         trace_act("ignore multicast %s", str);
1261                         continue;
1262                 }
1263
1264 #if defined(RTF_LLINFO)
1265                 if (m.r.rtm.rtm_flags & RTF_LLINFO) {
1266                         trace_act("ignore ARP %s", str);
1267                         continue;
1268                 }
1269 #endif
1270
1271 #if defined(RTF_WASCLONED) && defined(__FreeBSD__)
1272                 if (m.r.rtm.rtm_flags & RTF_WASCLONED) {
1273                         trace_act("ignore cloned %s", str);
1274                         continue;
1275                 }
1276 #endif
1277
1278                 if (get_info_gate(&INFO_GATE(&info), &gate_sin)) {
1279                         gate = S_ADDR(INFO_GATE(&info));
1280                         strp += sprintf(strp, " --> %s", naddr_ntoa(gate));
1281                 } else {
1282                         gate = 0;
1283                 }
1284
1285                 if (INFO_AUTHOR(&info) != 0)
1286                         strp += sprintf(strp, " by authority of %s",
1287                                         saddr_ntoa(INFO_AUTHOR(&info)));
1288
1289                 switch (m.r.rtm.rtm_type) {
1290                 case RTM_ADD:
1291                 case RTM_CHANGE:
1292                 case RTM_REDIRECT:
1293                         if (m.r.rtm.rtm_errno != 0) {
1294                                 trace_act("ignore %s with \"%s\" error",
1295                                           str, strerror(m.r.rtm.rtm_errno));
1296                         } else {
1297                                 trace_act("%s", str);
1298                                 rtm_add(&m.r.rtm,&info,0);
1299                         }
1300                         break;
1301
1302                 case RTM_DELETE:
1303                         if (m.r.rtm.rtm_errno != 0
1304                             && m.r.rtm.rtm_errno != ESRCH) {
1305                                 trace_act("ignore %s with \"%s\" error",
1306                                           str, strerror(m.r.rtm.rtm_errno));
1307                         } else {
1308                                 trace_act("%s", str);
1309                                 del_static(S_ADDR(INFO_DST(&info)), mask,
1310                                            gate, 1);
1311                         }
1312                         break;
1313
1314                 case RTM_LOSING:
1315                         trace_act("%s", str);
1316                         rtm_lose(&m.r.rtm,&info);
1317                         break;
1318
1319                 default:
1320                         trace_act("ignore %s", str);
1321                         break;
1322                 }
1323         }
1324 }
1325
1326
1327 /* after aggregating, note routes that belong in the kernel
1328  */
1329 static void
1330 kern_out(struct ag_info *ag)
1331 {
1332         struct khash *k;
1333
1334
1335         /* Do not install bad routes if they are not already present.
1336          * This includes routes that had RS_NET_SYN for interfaces that
1337          * recently died.
1338          */
1339         if (ag->ag_metric == HOPCNT_INFINITY) {
1340                 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0);
1341                 if (k == 0)
1342                         return;
1343         } else {
1344                 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask);
1345         }
1346
1347         if (k->k_state & KS_NEW) {
1348                 /* will need to add new entry to the kernel table */
1349                 k->k_state = KS_ADD;
1350                 if (ag->ag_state & AGS_GATEWAY)
1351                         k->k_state |= KS_GATEWAY;
1352                 k->k_gate = ag->ag_gate;
1353                 k->k_metric = ag->ag_metric;
1354                 return;
1355         }
1356
1357         if (k->k_state & KS_STATIC)
1358                 return;
1359
1360         /* modify existing kernel entry if necessary */
1361         if (k->k_gate != ag->ag_gate
1362             || k->k_metric != ag->ag_metric) {
1363                 /* Must delete bad interface routes etc. to change them. */
1364                 if (k->k_metric == HOPCNT_INFINITY)
1365                         k->k_state |= KS_DEL_ADD;
1366                 k->k_gate = ag->ag_gate;
1367                 k->k_metric = ag->ag_metric;
1368                 k->k_state |= KS_CHANGE;
1369         }
1370
1371         /* If the daemon thinks the route should exist, forget
1372          * about any redirections.
1373          * If the daemon thinks the route should exist, eventually
1374          * override manual intervention by the operator.
1375          */
1376         if ((k->k_state & (KS_DYNAMIC | KS_DELETED)) != 0) {
1377                 k->k_state &= ~KS_DYNAMIC;
1378                 k->k_state |= (KS_ADD | KS_DEL_ADD);
1379         }
1380
1381         if ((k->k_state & KS_GATEWAY)
1382             && !(ag->ag_state & AGS_GATEWAY)) {
1383                 k->k_state &= ~KS_GATEWAY;
1384                 k->k_state |= (KS_ADD | KS_DEL_ADD);
1385         } else if (!(k->k_state & KS_GATEWAY)
1386                    && (ag->ag_state & AGS_GATEWAY)) {
1387                 k->k_state |= KS_GATEWAY;
1388                 k->k_state |= (KS_ADD | KS_DEL_ADD);
1389         }
1390
1391         /* Deleting-and-adding is necessary to change aspects of a route.
1392          * Just delete instead of deleting and then adding a bad route.
1393          * Otherwise, we want to keep the route in the kernel.
1394          */
1395         if (k->k_metric == HOPCNT_INFINITY
1396             && (k->k_state & KS_DEL_ADD))
1397                 k->k_state |= KS_DELETE;
1398         else
1399                 k->k_state &= ~KS_DELETE;
1400 #undef RT
1401 }
1402
1403
1404 /* ARGSUSED */
1405 static int
1406 walk_kern(struct radix_node *rn,
1407           struct walkarg *argp UNUSED)
1408 {
1409 #define RT ((struct rt_entry *)rn)
1410         char metric, pref;
1411         u_int ags = 0;
1412
1413
1414         /* Do not install synthetic routes */
1415         if (RT->rt_state & RS_NET_SYN)
1416                 return 0;
1417
1418         if (!(RT->rt_state & RS_IF)) {
1419                 /* This is an ordinary route, not for an interface.
1420                  */
1421
1422                 /* aggregate, ordinary good routes without regard to
1423                  * their metric
1424                  */
1425                 pref = 1;
1426                 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE);
1427
1428                 /* Do not install host routes directly to hosts, to avoid
1429                  * interfering with ARP entries in the kernel table.
1430                  */
1431                 if (RT_ISHOST(RT)
1432                     && ntohl(RT->rt_dst) == RT->rt_gate)
1433                         return 0;
1434
1435         } else {
1436                 /* This is an interface route.
1437                  * Do not install routes for "external" remote interfaces.
1438                  */
1439                 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL))
1440                         return 0;
1441
1442                 /* Interfaces should override received routes.
1443                  */
1444                 pref = 0;
1445                 ags |= (AGS_IF | AGS_CORS_GATE);
1446
1447                 /* If it is not an interface, or an alias for an interface,
1448                  * it must be a "gateway."
1449                  *
1450                  * If it is a "remote" interface, it is also a "gateway" to
1451                  * the kernel if is not an alias.
1452                  */
1453                 if (RT->rt_ifp == 0
1454                     || (RT->rt_ifp->int_state & IS_REMOTE))
1455                         ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_AGGREGATE);
1456         }
1457
1458         /* If RIP is off and IRDP is on, let the route to the discovered
1459          * route suppress any RIP routes.  Eventually the RIP routes
1460          * will time-out and be deleted.  This reaches the steady-state
1461          * quicker.
1462          */
1463         if ((RT->rt_state & RS_RDISC) && rip_sock < 0)
1464                 ags |= AGS_CORS_GATE;
1465
1466         metric = RT->rt_metric;
1467         if (metric == HOPCNT_INFINITY) {
1468                 /* if the route is dead, so try hard to aggregate. */
1469                 pref = HOPCNT_INFINITY;
1470                 ags |= (AGS_FINE_GATE | AGS_SUPPRESS);
1471                 ags &= ~(AGS_IF | AGS_CORS_GATE);
1472         }
1473
1474         ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0,
1475                  metric,pref, 0, 0, ags, kern_out);
1476         return 0;
1477 #undef RT
1478 }
1479
1480
1481 /* Update the kernel table to match the daemon table.
1482  */
1483 static void
1484 fix_kern(void)
1485 {
1486         int i;
1487         struct khash *k, **pk;
1488
1489
1490         need_kern = age_timer;
1491
1492         /* Walk daemon table, updating the copy of the kernel table.
1493          */
1494         (void)rn_walktree(rhead, walk_kern, 0);
1495         ag_flush(0,0,kern_out);
1496
1497         for (i = 0; i < KHASH_SIZE; i++) {
1498                 for (pk = &khash_bins[i]; (k = *pk) != 0; ) {
1499                         /* Do not touch static routes */
1500                         if (k->k_state & KS_STATIC) {
1501                                 kern_check_static(k,0);
1502                                 pk = &k->k_next;
1503                                 continue;
1504                         }
1505
1506                         /* check hold on routes deleted by the operator */
1507                         if (k->k_keep > now.tv_sec) {
1508                                 /* ensure we check when the hold is over */
1509                                 LIM_SEC(need_kern, k->k_keep);
1510                                 /* mark for the next cycle */
1511                                 k->k_state |= KS_DELETE;
1512                                 pk = &k->k_next;
1513                                 continue;
1514                         }
1515
1516                         if ((k->k_state & KS_DELETE)
1517                             && !(k->k_state & KS_DYNAMIC)) {
1518                                 kern_ioctl(k, RTM_DELETE, 0);
1519                                 *pk = k->k_next;
1520                                 free(k);
1521                                 continue;
1522                         }
1523
1524                         if (k->k_state & KS_DEL_ADD)
1525                                 kern_ioctl(k, RTM_DELETE, 0);
1526
1527                         if (k->k_state & KS_ADD) {
1528                                 kern_ioctl(k, RTM_ADD,
1529                                            ((0 != (k->k_state & (KS_GATEWAY
1530                                                         | KS_DYNAMIC)))
1531                                             ? RTF_GATEWAY : 0));
1532                         } else if (k->k_state & KS_CHANGE) {
1533                                 kern_ioctl(k,  RTM_CHANGE,
1534                                            ((0 != (k->k_state & (KS_GATEWAY
1535                                                         | KS_DYNAMIC)))
1536                                             ? RTF_GATEWAY : 0));
1537                         }
1538                         k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD);
1539
1540                         /* Mark this route to be deleted in the next cycle.
1541                          * This deletes routes that disappear from the
1542                          * daemon table, since the normal aging code
1543                          * will clear the bit for routes that have not
1544                          * disappeared from the daemon table.
1545                          */
1546                         k->k_state |= KS_DELETE;
1547                         pk = &k->k_next;
1548                 }
1549         }
1550 }
1551
1552
1553 /* Delete a static route in the image of the kernel table.
1554  */
1555 void
1556 del_static(naddr dst,
1557            naddr mask,
1558            naddr gate,
1559            int gone)
1560 {
1561         struct khash *k;
1562         struct rt_entry *rt;
1563
1564         /* Just mark it in the table to be deleted next time the kernel
1565          * table is updated.
1566          * If it has already been deleted, mark it as such, and set its
1567          * keep-timer so that it will not be deleted again for a while.
1568          * This lets the operator delete a route added by the daemon
1569          * and add a replacement.
1570          */
1571         k = kern_find(dst, mask, 0);
1572         if (k != 0 && (gate == 0 || k->k_gate == gate)) {
1573                 k->k_state &= ~(KS_STATIC | KS_DYNAMIC | KS_CHECK);
1574                 k->k_state |= KS_DELETE;
1575                 if (gone) {
1576                         k->k_state |= KS_DELETED;
1577                         k->k_keep = now.tv_sec + K_KEEP_LIM;
1578                 }
1579         }
1580
1581         rt = rtget(dst, mask);
1582         if (rt != 0 && (rt->rt_state & RS_STATIC))
1583                 rtbad(rt);
1584 }
1585
1586
1587 /* Delete all routes generated from ICMP Redirects that use a given gateway,
1588  * as well as old redirected routes.
1589  */
1590 void
1591 del_redirects(naddr bad_gate,
1592               time_t old)
1593 {
1594         int i;
1595         struct khash *k;
1596
1597
1598         for (i = 0; i < KHASH_SIZE; i++) {
1599                 for (k = khash_bins[i]; k != 0; k = k->k_next) {
1600                         if (!(k->k_state & KS_DYNAMIC)
1601                             || (k->k_state & KS_STATIC))
1602                                 continue;
1603
1604                         if (k->k_gate != bad_gate
1605                             && k->k_redirect_time > old
1606                             && !supplier)
1607                                 continue;
1608
1609                         k->k_state |= KS_DELETE;
1610                         k->k_state &= ~KS_DYNAMIC;
1611                         need_kern.tv_sec = now.tv_sec;
1612                         trace_act("mark redirected %s --> %s for deletion",
1613                                   addrname(k->k_dst, k->k_mask, 0),
1614                                   naddr_ntoa(k->k_gate));
1615                 }
1616         }
1617 }
1618
1619
1620 /* Start the daemon tables.
1621  */
1622 extern int max_keylen;
1623
1624 void
1625 rtinit(void)
1626 {
1627         int i;
1628         struct ag_info *ag;
1629
1630         /* Initialize the radix trees */
1631         max_keylen = sizeof(struct sockaddr_in);
1632         rn_init();
1633         rn_inithead(&rhead, 32);
1634
1635         /* mark all of the slots in the table free */
1636         ag_avail = ag_slots;
1637         for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) {
1638                 ag->ag_fine = ag+1;
1639                 ag++;
1640         }
1641 }
1642
1643
1644 #ifdef _HAVE_SIN_LEN
1645 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET, 0, {0}, {0}};
1646 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET, 0, {0}, {0}};
1647 #else
1648 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET};
1649 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET};
1650 #endif
1651
1652
1653 static void
1654 set_need_flash(void)
1655 {
1656         if (!need_flash) {
1657                 need_flash = 1;
1658                 /* Do not send the flash update immediately.  Wait a little
1659                  * while to hear from other routers.
1660                  */
1661                 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME;
1662         }
1663 }
1664
1665
1666 /* Get a particular routing table entry
1667  */
1668 struct rt_entry *
1669 rtget(naddr dst, naddr mask)
1670 {
1671         struct rt_entry *rt;
1672
1673         dst_sock.sin_addr.s_addr = dst;
1674         mask_sock.sin_addr.s_addr = htonl(mask);
1675         masktrim(&mask_sock);
1676         rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead);
1677         if (!rt
1678             || rt->rt_dst != dst
1679             || rt->rt_mask != mask)
1680                 return 0;
1681
1682         return rt;
1683 }
1684
1685
1686 /* Find a route to dst as the kernel would.
1687  */
1688 struct rt_entry *
1689 rtfind(naddr dst)
1690 {
1691         dst_sock.sin_addr.s_addr = dst;
1692         return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead);
1693 }
1694
1695
1696 /* add a route to the table
1697  */
1698 void
1699 rtadd(naddr     dst,
1700       naddr     mask,
1701       u_int     state,                  /* rt_state for the entry */
1702       struct    rt_spare *new)
1703 {
1704         struct rt_entry *rt;
1705         naddr smask;
1706         int i;
1707         struct rt_spare *rts;
1708
1709         rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd");
1710         memset(rt, 0, sizeof(*rt));
1711         for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++)
1712                 rts->rts_metric = HOPCNT_INFINITY;
1713
1714         rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock;
1715         rt->rt_dst = dst;
1716         rt->rt_dst_sock.sin_family = AF_INET;
1717 #ifdef _HAVE_SIN_LEN
1718         rt->rt_dst_sock.sin_len = dst_sock.sin_len;
1719 #endif
1720         if (mask != HOST_MASK) {
1721                 smask = std_mask(dst);
1722                 if ((smask & ~mask) == 0 && mask > smask)
1723                         state |= RS_SUBNET;
1724         }
1725         mask_sock.sin_addr.s_addr = htonl(mask);
1726         masktrim(&mask_sock);
1727         rt->rt_mask = mask;
1728         rt->rt_state = state;
1729         rt->rt_spares[0] = *new;
1730         rt->rt_time = now.tv_sec;
1731         rt->rt_poison_metric = HOPCNT_INFINITY;
1732         rt->rt_seqno = update_seqno;
1733
1734         if (++total_routes == MAX_ROUTES)
1735                 msglog("have maximum (%d) routes", total_routes);
1736         if (TRACEACTIONS)
1737                 trace_add_del("Add", rt);
1738
1739         need_kern.tv_sec = now.tv_sec;
1740         set_need_flash();
1741
1742         if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock,
1743                                     rhead, rt->rt_nodes)) {
1744                 msglog("rnh_addaddr() failed for %s mask=%#lx",
1745                        naddr_ntoa(dst), (u_long)mask);
1746                 free(rt);
1747         }
1748 }
1749
1750
1751 /* notice a changed route
1752  */
1753 void
1754 rtchange(struct rt_entry *rt,
1755          u_int  state,                  /* new state bits */
1756          struct rt_spare *new,
1757          char   *label)
1758 {
1759         if (rt->rt_metric != new->rts_metric) {
1760                 /* Fix the kernel immediately if it seems the route
1761                  * has gone bad, since there may be a working route that
1762                  * aggregates this route.
1763                  */
1764                 if (new->rts_metric == HOPCNT_INFINITY) {
1765                         need_kern.tv_sec = now.tv_sec;
1766                         if (new->rts_time >= now.tv_sec - EXPIRE_TIME)
1767                                 new->rts_time = now.tv_sec - EXPIRE_TIME;
1768                 }
1769                 rt->rt_seqno = update_seqno;
1770                 set_need_flash();
1771         }
1772
1773         if (rt->rt_gate != new->rts_gate) {
1774                 need_kern.tv_sec = now.tv_sec;
1775                 rt->rt_seqno = update_seqno;
1776                 set_need_flash();
1777         }
1778
1779         state |= (rt->rt_state & RS_SUBNET);
1780
1781         /* Keep various things from deciding ageless routes are stale.
1782          */
1783         if (!AGE_RT(state, new->rts_ifp))
1784                 new->rts_time = now.tv_sec;
1785
1786         if (TRACEACTIONS)
1787                 trace_change(rt, state, new,
1788                              label ? label : "Chg   ");
1789
1790         rt->rt_state = state;
1791         rt->rt_spares[0] = *new;
1792 }
1793
1794
1795 /* check for a better route among the spares
1796  */
1797 static struct rt_spare *
1798 rts_better(struct rt_entry *rt)
1799 {
1800         struct rt_spare *rts, *rts1;
1801         int i;
1802
1803         /* find the best alternative among the spares */
1804         rts = rt->rt_spares+1;
1805         for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) {
1806                 if (BETTER_LINK(rt,rts1,rts))
1807                         rts = rts1;
1808         }
1809
1810         return rts;
1811 }
1812
1813
1814 /* switch to a backup route
1815  */
1816 void
1817 rtswitch(struct rt_entry *rt,
1818          struct rt_spare *rts)
1819 {
1820         struct rt_spare swap;
1821         char label[10];
1822
1823
1824         /* Do not change permanent routes */
1825         if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC
1826                                   | RS_NET_SYN | RS_IF)))
1827                 return;
1828
1829         /* find the best alternative among the spares */
1830         if (rts == 0)
1831                 rts = rts_better(rt);
1832
1833         /* Do not bother if it is not worthwhile.
1834          */
1835         if (!BETTER_LINK(rt, rts, rt->rt_spares))
1836                 return;
1837
1838         swap = rt->rt_spares[0];
1839         (void)sprintf(label, "Use #%d", (int)(rts - rt->rt_spares));
1840         rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), rts, label);
1841         if (swap.rts_metric == HOPCNT_INFINITY) {
1842                 *rts = rts_empty;
1843         } else {
1844                 *rts = swap;
1845         }
1846 }
1847
1848
1849 void
1850 rtdelete(struct rt_entry *rt)
1851 {
1852         struct khash *k;
1853
1854
1855         if (TRACEACTIONS)
1856                 trace_add_del("Del", rt);
1857
1858         k = kern_find(rt->rt_dst, rt->rt_mask, 0);
1859         if (k != 0) {
1860                 k->k_state |= KS_DELETE;
1861                 need_kern.tv_sec = now.tv_sec;
1862         }
1863
1864         dst_sock.sin_addr.s_addr = rt->rt_dst;
1865         mask_sock.sin_addr.s_addr = htonl(rt->rt_mask);
1866         masktrim(&mask_sock);
1867         if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock,
1868                                                         rhead)) {
1869                 msglog("rnh_deladdr() failed");
1870         } else {
1871                 free(rt);
1872                 total_routes--;
1873         }
1874 }
1875
1876
1877 void
1878 rts_delete(struct rt_entry *rt,
1879            struct rt_spare *rts)
1880 {
1881         trace_upslot(rt, rts, &rts_empty);
1882         *rts = rts_empty;
1883 }
1884
1885
1886 /* Get rid of a bad route, and try to switch to a replacement.
1887  */
1888 static void
1889 rtbad(struct rt_entry *rt)
1890 {
1891         struct rt_spare new;
1892
1893         /* Poison the route */
1894         new = rt->rt_spares[0];
1895         new.rts_metric = HOPCNT_INFINITY;
1896         rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), &new, 0);
1897         rtswitch(rt, 0);
1898 }
1899
1900
1901 /* Junk a RS_NET_SYN or RS_LOCAL route,
1902  *      unless it is needed by another interface.
1903  */
1904 void
1905 rtbad_sub(struct rt_entry *rt)
1906 {
1907         struct interface *ifp, *ifp1;
1908         struct intnet *intnetp;
1909         u_int state;
1910
1911
1912         ifp1 = 0;
1913         state = 0;
1914
1915         if (rt->rt_state & RS_LOCAL) {
1916                 /* Is this the route through loopback for the interface?
1917                  * If so, see if it is used by any other interfaces, such
1918                  * as a point-to-point interface with the same local address.
1919                  */
1920                 LIST_FOREACH(ifp, &ifnet, int_list) {
1921                         /* Retain it if another interface needs it.
1922                          */
1923                         if (ifp->int_addr == rt->rt_ifp->int_addr) {
1924                                 state |= RS_LOCAL;
1925                                 ifp1 = ifp;
1926                                 break;
1927                         }
1928                 }
1929
1930         }
1931
1932         if (!(state & RS_LOCAL)) {
1933                 /* Retain RIPv1 logical network route if there is another
1934                  * interface that justifies it.
1935                  */
1936                 if (rt->rt_state & RS_NET_SYN) {
1937                         LIST_FOREACH(ifp, &ifnet, int_list) {
1938                                 if ((ifp->int_state & IS_NEED_NET_SYN)
1939                                     && rt->rt_mask == ifp->int_std_mask
1940                                     && rt->rt_dst == ifp->int_std_addr) {
1941                                         state |= RS_NET_SYN;
1942                                         ifp1 = ifp;
1943                                         break;
1944                                 }
1945                         }
1946                 }
1947
1948                 /* or if there is an authority route that needs it. */
1949                 for (intnetp = intnets;
1950                      intnetp != 0;
1951                      intnetp = intnetp->intnet_next) {
1952                         if (intnetp->intnet_addr == rt->rt_dst
1953                             && intnetp->intnet_mask == rt->rt_mask) {
1954                                 state |= (RS_NET_SYN | RS_NET_INT);
1955                                 break;
1956                         }
1957                 }
1958         }
1959
1960         if (ifp1 != 0 || (state & RS_NET_SYN)) {
1961                 struct rt_spare new = rt->rt_spares[0];
1962                 new.rts_ifp = ifp1;
1963                 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN|RS_LOCAL)) | state),
1964                          &new, 0);
1965         } else {
1966                 rtbad(rt);
1967         }
1968 }
1969
1970
1971 /* Called while walking the table looking for sick interfaces
1972  * or after a time change.
1973  */
1974 /* ARGSUSED */
1975 int
1976 walk_bad(struct radix_node *rn,
1977          struct walkarg *argp UNUSED)
1978 {
1979 #define RT ((struct rt_entry *)rn)
1980         struct rt_spare *rts;
1981         int i;
1982
1983
1984         /* fix any spare routes through the interface
1985          */
1986         rts = RT->rt_spares;
1987         for (i = NUM_SPARES; i != 1; i--) {
1988                 rts++;
1989                 if (rts->rts_metric < HOPCNT_INFINITY
1990                     && (rts->rts_ifp == 0
1991                         || (rts->rts_ifp->int_state & IS_BROKE)))
1992                         rts_delete(RT, rts);
1993         }
1994
1995         /* Deal with the main route
1996          */
1997         /* finished if it has been handled before or if its interface is ok
1998          */
1999         if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE))
2000                 return 0;
2001
2002         /* Bad routes for other than interfaces are easy.
2003          */
2004         if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) {
2005                 rtbad(RT);
2006                 return 0;
2007         }
2008
2009         rtbad_sub(RT);
2010         return 0;
2011 #undef RT
2012 }
2013
2014
2015 /* Check the age of an individual route.
2016  */
2017 /* ARGSUSED */
2018 static int
2019 walk_age(struct radix_node *rn,
2020            struct walkarg *argp UNUSED)
2021 {
2022 #define RT ((struct rt_entry *)rn)
2023         struct interface *ifp;
2024         struct rt_spare *rts;
2025         int i;
2026
2027
2028         /* age all of the spare routes, including the primary route
2029          * currently in use
2030          */
2031         rts = RT->rt_spares;
2032         for (i = NUM_SPARES; i != 0; i--, rts++) {
2033
2034                 ifp = rts->rts_ifp;
2035                 if (i == NUM_SPARES) {
2036                         if (!AGE_RT(RT->rt_state, ifp)) {
2037                                 /* Keep various things from deciding ageless
2038                                  * routes are stale
2039                                  */
2040                                 rts->rts_time = now.tv_sec;
2041                                 continue;
2042                         }
2043
2044                         /* forget RIP routes after RIP has been turned off.
2045                          */
2046                         if (rip_sock < 0) {
2047                                 rtdelete(RT);
2048                                 return 0;
2049                         }
2050                 }
2051
2052                 /* age failing routes
2053                  */
2054                 if (age_bad_gate == rts->rts_gate
2055                     && rts->rts_time >= now_stale) {
2056                         rts->rts_time -= SUPPLY_INTERVAL;
2057                 }
2058
2059                 /* trash the spare routes when they go bad */
2060                 if (rts->rts_metric < HOPCNT_INFINITY
2061                     && now_garbage > rts->rts_time
2062                     && i != NUM_SPARES)
2063                         rts_delete(RT, rts);
2064         }
2065
2066
2067         /* finished if the active route is still fresh */
2068         if (now_stale <= RT->rt_time)
2069                 return 0;
2070
2071         /* try to switch to an alternative */
2072         rtswitch(RT, 0);
2073
2074         /* Delete a dead route after it has been publically mourned. */
2075         if (now_garbage > RT->rt_time) {
2076                 rtdelete(RT);
2077                 return 0;
2078         }
2079
2080         /* Start poisoning a bad route before deleting it. */
2081         if (now.tv_sec - RT->rt_time > EXPIRE_TIME) {
2082                 struct rt_spare new = RT->rt_spares[0];
2083                 new.rts_metric = HOPCNT_INFINITY;
2084                 rtchange(RT, RT->rt_state, &new, 0);
2085         }
2086         return 0;
2087 }
2088
2089
2090 /* Watch for dead routes and interfaces.
2091  */
2092 void
2093 age(naddr bad_gate)
2094 {
2095         struct interface *ifp;
2096         int need_query = 0;
2097
2098         /* If not listening to RIP, there is no need to age the routes in
2099          * the table.
2100          */
2101         age_timer.tv_sec = (now.tv_sec
2102                             + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL));
2103
2104         /* Check for dead IS_REMOTE interfaces by timing their
2105          * transmissions.
2106          */
2107         LIST_FOREACH(ifp, &ifnet, int_list) {
2108                 if (!(ifp->int_state & IS_REMOTE))
2109                         continue;
2110
2111                 /* ignore unreachable remote interfaces */
2112                 if (!check_remote(ifp))
2113                         continue;
2114
2115                 /* Restore remote interface that has become reachable
2116                  */
2117                 if (ifp->int_state & IS_BROKE)
2118                         if_ok(ifp, "remote ");
2119
2120                 if (ifp->int_act_time != NEVER
2121                     && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) {
2122                         msglog("remote interface %s to %s timed out after"
2123                                " %ld:%ld",
2124                                ifp->int_name,
2125                                naddr_ntoa(ifp->int_dstaddr),
2126                                (long)(now.tv_sec - ifp->int_act_time)/60,
2127                                (long)(now.tv_sec - ifp->int_act_time)%60);
2128                         if_sick(ifp);
2129                 }
2130
2131                 /* If we have not heard from the other router
2132                  * recently, ask it.
2133                  */
2134                 if (now.tv_sec >= ifp->int_query_time) {
2135                         ifp->int_query_time = NEVER;
2136                         need_query = 1;
2137                 }
2138         }
2139
2140         /* Age routes. */
2141         age_bad_gate = bad_gate;
2142         (void)rn_walktree(rhead, walk_age, 0);
2143
2144         /* delete old redirected routes to keep the kernel table small
2145          * and prevent blackholes
2146          */
2147         del_redirects(bad_gate, now.tv_sec-STALE_TIME);
2148
2149         /* Update the kernel routing table. */
2150         fix_kern();
2151
2152         /* poke reticent remote gateways */
2153         if (need_query)
2154                 rip_query();
2155 }