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
ag_out(struct ag_info * ag,void (* out)(struct ag_info *))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
ag_del(struct ag_info * ag)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
ag_flush(naddr lim_dst_h,naddr lim_mask,void (* out)(struct ag_info *))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
ag_check(naddr dst,naddr mask,naddr gate,naddr nhop,char metric,char pref,u_int new_seqno,u_short tag,u_short state,void (* out)(struct ag_info *))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 *
rtm_type_name(u_char type)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
masktrim(struct sockaddr_in * ap)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
rtioctl(int action,naddr dst,naddr gate,naddr mask,int metric,int flags)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*
kern_find(naddr dst,naddr mask,struct khash *** ppk)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*
kern_add(naddr dst,naddr mask)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
kern_check_static(struct khash * k,struct interface * ifp)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
kern_ioctl(struct khash * k,int action,int flags)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
rtm_add(struct rt_msghdr * rtm,struct rt_addrinfo * info,time_t keep)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
rtm_lose(struct rt_msghdr * rtm,struct rt_addrinfo * info)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
get_info_gate(struct sockaddr ** sap,struct sockaddr_in * rsin)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
flush_kern(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
read_rt(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
kern_out(struct ag_info * ag)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
walk_kern(struct radix_node * rn,struct walkarg * argp UNUSED)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
fix_kern(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
del_static(naddr dst,naddr mask,naddr gate,int gone)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
del_redirects(naddr bad_gate,time_t old)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
rtinit(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
set_need_flash(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 *
rtget(naddr dst,naddr mask)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 *
rtfind(naddr dst)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
rtadd(naddr dst,naddr mask,u_int state,struct rt_spare * new)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
rtchange(struct rt_entry * rt,u_int state,struct rt_spare * new,char * label)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 *
rts_better(struct rt_entry * rt)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
rtswitch(struct rt_entry * rt,struct rt_spare * rts)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
rtdelete(struct rt_entry * rt)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
rts_delete(struct rt_entry * rt,struct rt_spare * rts)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
rtbad(struct rt_entry * rt)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
rtbad_sub(struct rt_entry * rt)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
walk_bad(struct radix_node * rn,struct walkarg * argp UNUSED)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
walk_age(struct radix_node * rn,struct walkarg * argp UNUSED)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 publicly 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
age(naddr bad_gate)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 }
2156