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