xref: /openbsd/usr.sbin/ospf6d/rde_spf.c (revision 3cab2bb3)
1 /*	$OpenBSD: rde_spf.c,v 1.28 2020/04/05 18:19:04 denis Exp $ */
2 
3 /*
4  * Copyright (c) 2005 Esben Norby <norby@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <netinet/in.h>
22 #include <arpa/inet.h>
23 #include <err.h>
24 #include <stdlib.h>
25 #include <string.h>
26 
27 #include "ospf6d.h"
28 #include "ospf6.h"
29 #include "log.h"
30 #include "rde.h"
31 
32 extern struct ospfd_conf	*rdeconf;
33 TAILQ_HEAD(, vertex)		 cand_list;
34 RB_HEAD(rt_tree, rt_node)	 rt;
35 RB_PROTOTYPE(rt_tree, rt_node, entry, rt_compare)
36 RB_GENERATE(rt_tree, rt_node, entry, rt_compare)
37 struct vertex			*spf_root = NULL;
38 
39 struct in6_addr	*calc_nexthop_lladdr(struct vertex *, struct lsa_rtr_link *,
40 		     unsigned int);
41 void		 calc_nexthop_transit_nbr(struct vertex *, struct vertex *,
42 		     unsigned int);
43 void		 calc_nexthop(struct vertex *, struct vertex *,
44 		     struct area *, struct lsa_rtr_link *);
45 void		 rt_nexthop_clear(struct rt_node *);
46 void		 rt_nexthop_add(struct rt_node *, struct v_nexthead *,
47 		     u_int16_t, struct in_addr);
48 void		 rt_update(struct in6_addr *, u_int8_t, struct v_nexthead *,
49 		     u_int16_t, u_int32_t, u_int32_t, struct in_addr,
50 		     struct in_addr, enum path_type, enum dst_type, u_int8_t,
51 		     u_int32_t);
52 struct rt_node	*rt_lookup(enum dst_type, struct in6_addr *);
53 void		 rt_invalidate(struct area *);
54 int		 linked(struct vertex *, struct vertex *);
55 
56 void
57 spf_calc(struct area *area)
58 {
59 	struct vertex		*v, *w;
60 	struct lsa_rtr_link	*rtr_link = NULL;
61 	struct lsa_net_link	*net_link;
62 	u_int32_t		 d;
63 	unsigned int		 i;
64 
65 	/* clear SPF tree */
66 	spf_tree_clr(area);
67 	cand_list_clr();
68 
69 	/* initialize SPF tree */
70 	if ((v = spf_root = lsa_find_rtr(area, rde_router_id())) == NULL)
71 		/* empty area because no interface is active */
72 		return;
73 
74 	area->transit = 0;
75 	spf_root->cost = 0;
76 	w = NULL;
77 
78 	/* calculate SPF tree */
79 	do {
80 		/* loop links */
81 		for (i = 0; i < lsa_num_links(v); i++) {
82 			switch (v->type) {
83 			case LSA_TYPE_ROUTER:
84 				rtr_link = get_rtr_link(v, i);
85 				switch (rtr_link->type) {
86 				case LINK_TYPE_POINTTOPOINT:
87 				case LINK_TYPE_VIRTUAL:
88 					/* find router LSA */
89 					w = lsa_find_rtr(area,
90 					    rtr_link->nbr_rtr_id);
91 					break;
92 				case LINK_TYPE_TRANSIT_NET:
93 					/* find network LSA */
94 					w = lsa_find_tree(&area->lsa_tree,
95 					    htons(LSA_TYPE_NETWORK),
96 					    rtr_link->nbr_iface_id,
97 					    rtr_link->nbr_rtr_id);
98 					break;
99 				default:
100 					fatalx("spf_calc: invalid link type");
101 				}
102 				break;
103 			case LSA_TYPE_NETWORK:
104 				net_link = get_net_link(v, i);
105 				/* find router LSA */
106 				w = lsa_find_rtr(area, net_link->att_rtr);
107 				break;
108 			default:
109 				fatalx("spf_calc: invalid LSA type");
110 			}
111 
112 			if (w == NULL)
113 				continue;
114 
115 			if (ntohs(w->lsa->hdr.age) == MAX_AGE)
116 				continue;
117 
118 			if (lsa_num_links(w) == 0)
119 				continue;
120 
121 			if (!linked(w, v)) {
122 				log_debug("spf_calc: w adv_rtr %s ls_id %s "
123 				    "type 0x%x numlinks %hu has no link to "
124 				    "v adv_rtr %s ls_id %s type 0x%x",
125 				    log_rtr_id(htonl(w->adv_rtr)),
126 				    log_rtr_id(htonl(w->ls_id)), w->type,
127 				    lsa_num_links(w),
128 				    log_rtr_id(htonl(v->adv_rtr)),
129 				    log_rtr_id(htonl(v->ls_id)), v->type);
130 				continue;
131 			}
132 
133 			if (v->type == LSA_TYPE_ROUTER)
134 				d = v->cost + ntohs(rtr_link->metric);
135 			else
136 				d = v->cost;
137 
138 			if (cand_list_present(w)) {
139 				if (d > w->cost)
140 					continue;
141 				if (d < w->cost) {
142 					w->cost = d;
143 					vertex_nexthop_clear(w);
144 					calc_nexthop(w, v, area, rtr_link);
145 					/*
146 					 * need to readd to candidate list
147 					 * because the list is sorted
148 					 */
149 					TAILQ_REMOVE(&cand_list, w, cand);
150 					cand_list_add(w);
151 				} else
152 					/* equal cost path */
153 					calc_nexthop(w, v, area, rtr_link);
154 			} else if (w->cost == LS_INFINITY && d < LS_INFINITY) {
155 				w->cost = d;
156 
157 				vertex_nexthop_clear(w);
158 				calc_nexthop(w, v, area, rtr_link);
159 				cand_list_add(w);
160 			}
161 		}
162 
163 		/* get next vertex */
164 		v = cand_list_pop();
165 		w = NULL;
166 	} while (v != NULL);
167 
168 	/* spf_dump(area); */
169 	log_debug("spf_calc: area %s calculated", inet_ntoa(area->id));
170 
171 	/* Dump SPF tree to log */
172 	RB_FOREACH(v, lsa_tree, &area->lsa_tree) {
173 		struct v_nexthop *vn;
174 		char hops[4096];
175 		struct iface *iface;
176 
177 		bzero(hops, sizeof(hops));
178 
179 		if (v->type != LSA_TYPE_ROUTER && v->type != LSA_TYPE_NETWORK)
180 			continue;
181 
182 		TAILQ_FOREACH(vn, &v->nexthop, entry) {
183 			strlcat(hops, log_in6addr(&vn->nexthop), sizeof(hops));
184 			strlcat(hops, "%", sizeof(hops));
185 			if ((iface = if_find(vn->ifindex)) == NULL)
186 				fatalx("spf_calc: lost iface");
187 			strlcat(hops, iface->name, sizeof(hops));
188 			if (vn != TAILQ_LAST(&v->nexthop, v_nexthead))
189 				strlcat(hops, ", ", sizeof(hops));
190 		}
191 		log_debug("%s(%s, 0x%x, %s) cost %u has nexthops [%s]",
192 		    v == spf_root ? "*" : " ", log_rtr_id(htonl(v->adv_rtr)),
193 		    v->type, log_rtr_id(htonl(v->ls_id)), v->cost, hops);
194 	}
195 
196 	area->num_spf_calc++;
197 	start_spf_timer();
198 }
199 
200 void
201 rt_calc(struct vertex *v, struct area *area, struct ospfd_conf *conf)
202 {
203 	struct vertex		*w;
204 	struct lsa_intra_prefix	*iap;
205 	struct lsa_prefix	*prefix;
206 	struct in_addr		 adv_rtr;
207 	struct in6_addr		 ia6;
208 	u_int16_t		 i, off;
209 	u_int8_t		 flags;
210 
211 	lsa_age(v);
212 	if (ntohs(v->lsa->hdr.age) == MAX_AGE)
213 		return;
214 
215 	switch (v->type) {
216 	case LSA_TYPE_ROUTER:
217 		if (v->cost >= LS_INFINITY || TAILQ_EMPTY(&v->nexthop))
218 			return;
219 
220 		/* router, only add border and as-external routers */
221 		flags = LSA_24_GETHI(ntohl(v->lsa->data.rtr.opts));
222 		if ((flags & (OSPF_RTR_B | OSPF_RTR_E)) == 0)
223 			return;
224 
225 		bzero(&ia6, sizeof(ia6));
226 		adv_rtr.s_addr = htonl(v->adv_rtr);
227 		bcopy(&adv_rtr, &ia6.s6_addr[12], sizeof(adv_rtr));
228 
229 		rt_update(&ia6, 128, &v->nexthop, v->type, v->cost, 0, area->id,
230 		    adv_rtr, PT_INTER_AREA, DT_RTR, flags, 0);
231 		break;
232 	case LSA_TYPE_INTRA_A_PREFIX:
233 		/* Find referenced LSA */
234 		iap = &v->lsa->data.pref_intra;
235 		switch (ntohs(iap->ref_type)) {
236 		case LSA_TYPE_ROUTER:
237 			w = lsa_find_rtr(area, iap->ref_adv_rtr);
238 			if (w == NULL) {
239 				warnx("rt_calc: Intra-Area-Prefix LSA (%s, %u) "
240 				    "references non-existent router %s",
241 				    log_rtr_id(htonl(v->adv_rtr)),
242 				    v->ls_id, log_rtr_id(iap->ref_adv_rtr));
243 				return;
244 			}
245 			flags = LSA_24_GETHI(ntohl(w->lsa->data.rtr.opts));
246 			break;
247 		case LSA_TYPE_NETWORK:
248 			w = lsa_find_tree(&area->lsa_tree, iap->ref_type,
249 			    iap->ref_ls_id, iap->ref_adv_rtr);
250 			if (w == NULL) {
251 				warnx("rt_calc: Intra-Area-Prefix LSA (%s, %u) "
252 				    "references non-existent Network LSA (%s, "
253 				    "%u)", log_rtr_id(htonl(v->adv_rtr)),
254 				    v->ls_id, log_rtr_id(iap->ref_adv_rtr),
255 				    ntohl(iap->ref_ls_id));
256 				return;
257 			}
258 			flags = 0;
259 			break;
260 		default:
261 			warnx("rt_calc: Intra-Area-Prefix LSA (%s, %u) has "
262 			    "invalid ref_type 0x%hx", log_rtr_id(v->adv_rtr),
263 			    v->ls_id, ntohs(iap->ref_type));
264 			return;
265 		}
266 
267 		if (w->cost >= LS_INFINITY || TAILQ_EMPTY(&w->nexthop))
268 			return;
269 
270 		/* Add prefixes listed in Intra-Area-Prefix LSA to routing
271 		 * table, using w as destination. */
272 		off = sizeof(v->lsa->hdr) + sizeof(struct lsa_intra_prefix);
273 		for (i = 0; i < ntohs(v->lsa->data.pref_intra.numprefix); i++) {
274 			prefix = (struct lsa_prefix *)((char *)(v->lsa) + off);
275 			if (!(prefix->options & OSPF_PREFIX_NU)) {
276 				bzero(&ia6, sizeof(ia6));
277 				bcopy(prefix + 1, &ia6,
278 				    LSA_PREFIXSIZE(prefix->prefixlen));
279 
280 				adv_rtr.s_addr = htonl(w->adv_rtr);
281 
282 				rt_update(&ia6, prefix->prefixlen, &w->nexthop,
283 				    v->type, w->cost + ntohs(prefix->metric), 0,
284 				    area->id, adv_rtr, PT_INTRA_AREA, DT_NET,
285 				    flags, 0);
286 			}
287 			off += sizeof(struct lsa_prefix)
288 			    + LSA_PREFIXSIZE(prefix->prefixlen);
289 		}
290 		break;
291 	case LSA_TYPE_INTER_A_PREFIX:
292 		/* XXX if ABR only look at area 0.0.0.0 LSA */
293 		/* ignore self-originated stuff */
294 		if (v->self)
295 			return;
296 
297 		adv_rtr.s_addr = htonl(v->adv_rtr);
298 		w = lsa_find_rtr(area, adv_rtr.s_addr);
299 		if (w == NULL) {
300 			warnx("rt_calc: Inter-Area-Router LSA (%s, %u) "
301 			    "originated from non-existent router",
302 			    log_rtr_id(htonl(v->adv_rtr)),
303 			    v->ls_id);
304 			return;
305 		}
306 		if (w->cost >= LS_INFINITY || TAILQ_EMPTY(&w->nexthop))
307 			return;
308 
309 		/* Add prefix listed in Inter-Area-Prefix LSA to routing
310 		 * table, using w as destination. */
311 		off = sizeof(v->lsa->hdr) + sizeof(struct lsa_prefix_sum);
312 		prefix = (struct lsa_prefix *)((char *)(v->lsa) + off);
313 		if (prefix->options & OSPF_PREFIX_NU)
314 			return;
315 
316 		bzero(&ia6, sizeof(ia6));
317 		bcopy(prefix + 1, &ia6, LSA_PREFIXSIZE(prefix->prefixlen));
318 
319 		rt_update(&ia6, prefix->prefixlen, &w->nexthop, v->type,
320 		    w->cost + (ntohs(v->lsa->data.rtr_sum.metric) &
321 		    LSA_METRIC_MASK), 0, area->id, adv_rtr, PT_INTER_AREA,
322 		    DT_NET, 0, 0);
323 		break;
324 	case LSA_TYPE_INTER_A_ROUTER:
325 		/* XXX if ABR only look at area 0.0.0.0 LSA */
326 		/* ignore self-originated stuff */
327 		if (v->self)
328 			return;
329 
330 		adv_rtr.s_addr = htonl(v->adv_rtr);
331 		w = lsa_find_rtr(area, adv_rtr.s_addr);
332 		if (w == NULL) {
333 			warnx("rt_calc: Inter-Area-Router LSA (%s, %u) "
334 			    "originated from non-existent router",
335 			    log_rtr_id(htonl(v->adv_rtr)),
336 			    v->ls_id);
337 			return;
338 		}
339 		if (w->cost >= LS_INFINITY || TAILQ_EMPTY(&w->nexthop))
340 			return;
341 
342 		/* Add router listed in Inter-Area-Router LSA to routing
343 		 * table, using w as destination. */
344 		bzero(&ia6, sizeof(ia6));
345 		bcopy(&v->lsa->data.rtr_sum.dest_rtr_id, &ia6.s6_addr[12],
346 		    4);
347 
348 		rt_update(&ia6, 128, &w->nexthop, v->type, w->cost +
349 		    (ntohs(v->lsa->data.rtr_sum.metric) & LSA_METRIC_MASK), 0,
350 		    area->id, adv_rtr, PT_INTER_AREA, DT_RTR, 0, 0);
351 		break;
352 	default:
353 		break;
354 	}
355 }
356 
357 void
358 asext_calc(struct vertex *v)
359 {
360 	struct in6_addr		 addr, fw_addr;
361 	struct rt_node		*r;
362 	struct rt_nexthop	*rn;
363 	struct lsa_prefix	*prefix;
364 	struct in_addr		 adv_rtr, area;
365 	char			*p;
366 	u_int32_t		 metric, cost2, ext_tag = 0;
367 	enum path_type		 type;
368 
369 	lsa_age(v);
370 	if (ntohs(v->lsa->hdr.age) == MAX_AGE ||
371 	    (ntohl(v->lsa->data.asext.metric) & LSA_METRIC_MASK) >=
372 	    LS_INFINITY)
373 		return;
374 
375 	switch (v->type) {
376 	case LSA_TYPE_EXTERNAL:
377 		/* ignore self-originated stuff */
378 		if (v->self)
379 			return;
380 
381 		adv_rtr.s_addr = htonl(v->adv_rtr);
382 		bzero(&addr, sizeof(addr));
383 		bcopy(&adv_rtr, &addr.s6_addr[12], sizeof(adv_rtr));
384 		if ((r = rt_lookup(DT_RTR, &addr)) == NULL)
385 			return;
386 
387 		prefix = &v->lsa->data.asext.prefix;
388 		if (prefix->options & OSPF_PREFIX_NU)
389 			break;
390 		bzero(&addr, sizeof(addr));
391 		bcopy(prefix + 1, &addr,
392 		    LSA_PREFIXSIZE(prefix->prefixlen));
393 
394 		p = (char *)(prefix + 1) + LSA_PREFIXSIZE(prefix->prefixlen);
395 		metric = ntohl(v->lsa->data.asext.metric);
396 
397 		if (metric & LSA_ASEXT_F_FLAG) {
398 			bcopy(p, &fw_addr, sizeof(fw_addr));
399 			p += sizeof(fw_addr);
400 
401 			/* lookup forwarding address */
402 			if ((r = rt_lookup(DT_NET, &fw_addr)) == NULL ||
403 			    (r->p_type != PT_INTRA_AREA &&
404 			    r->p_type != PT_INTER_AREA))
405 				return;
406 		}
407 		if (metric & LSA_ASEXT_T_FLAG) {
408 			bcopy(p, &ext_tag, sizeof(ext_tag));
409 			p += sizeof(ext_tag);
410 		}
411 		if (metric & LSA_ASEXT_E_FLAG) {
412 			v->cost = r->cost;
413 			cost2 = metric & LSA_METRIC_MASK;
414 			type = PT_TYPE2_EXT;
415 		} else {
416 			v->cost = r->cost + (metric & LSA_METRIC_MASK);
417 			cost2 = 0;
418 			type = PT_TYPE1_EXT;
419 		}
420 
421 		area.s_addr = 0;
422 		vertex_nexthop_clear(v);
423 		TAILQ_FOREACH(rn, &r->nexthop, entry) {
424 			if (rn->invalid)
425 				continue;
426 
427 			if (rn->connected && r->d_type == DT_NET) {
428 				if (metric & LSA_ASEXT_F_FLAG)
429 					vertex_nexthop_add(v, NULL, &fw_addr,
430 					    rn->ifindex);
431 				else
432 					fatalx("asext_calc: I'm sorry Dave, "
433 					    "I'm afraid I can't do that.");
434 			} else
435 				vertex_nexthop_add(v, NULL, &rn->nexthop,
436 				    rn->ifindex);
437 		}
438 
439 		rt_update(&addr, prefix->prefixlen, &v->nexthop, v->type,
440 		    v->cost, cost2, area, adv_rtr, type, DT_NET, 0, ext_tag);
441 		break;
442 	default:
443 		fatalx("asext_calc: invalid LSA type");
444 	}
445 }
446 
447 void
448 spf_tree_clr(struct area *area)
449 {
450 	struct lsa_tree	*tree = &area->lsa_tree;
451 	struct vertex	*v;
452 
453 	RB_FOREACH(v, lsa_tree, tree) {
454 		v->cost = LS_INFINITY;
455 		vertex_nexthop_clear(v);
456 	}
457 }
458 
459 struct in6_addr *
460 calc_nexthop_lladdr(struct vertex *dst, struct lsa_rtr_link *rtr_link,
461     unsigned int ifindex)
462 {
463 	struct iface		*iface;
464 	struct vertex		*link;
465 	struct rde_nbr		*nbr;
466 
467 	/* Find outgoing interface, we need its LSA tree */
468 	LIST_FOREACH(iface, &dst->area->iface_list, entry) {
469 		if (ifindex == iface->ifindex)
470 			break;
471 	}
472 	if (!iface) {
473 		log_warnx("calc_nexthop_lladdr: no interface found for "
474 		    "ifindex %d", ntohl(rtr_link->iface_id));
475 		return (NULL);
476 	}
477 
478 	/* Determine neighbor's link-local address.
479 	 * Try to get it from link LSA first. */
480 	link = lsa_find_tree(&iface->lsa_tree,
481 		htons(LSA_TYPE_LINK), rtr_link->iface_id,
482 		htonl(dst->adv_rtr));
483 	if (link)
484 		return &link->lsa->data.link.lladdr;
485 
486 	/* Not found, so fall back to source address
487 	 * advertised in hello packet. */
488 	if ((nbr = rde_nbr_find(dst->peerid)) == NULL)
489 		fatalx("next hop is not a neighbor");
490 	return &nbr->addr;
491 }
492 
493 void
494 calc_nexthop_transit_nbr(struct vertex *dst, struct vertex *parent,
495     unsigned int ifindex)
496 {
497 	struct lsa_rtr_link	*rtr_link;
498 	unsigned int		 i;
499 	struct in6_addr		*lladdr;
500 
501 	if (dst->type != LSA_TYPE_ROUTER)
502 		fatalx("calc_nexthop_transit_nbr: dst is not a router");
503 	if (parent->type != LSA_TYPE_NETWORK)
504 		fatalx("calc_nexthop_transit_nbr: parent is not a network");
505 
506 	/* dst is a neighbor on a directly attached transit network.
507 	 * Figure out dst's link local address and add it as nexthop. */
508 	for (i = 0; i < lsa_num_links(dst); i++) {
509 		rtr_link = get_rtr_link(dst, i);
510 		if (rtr_link->type == LINK_TYPE_TRANSIT_NET &&
511 		    rtr_link->nbr_rtr_id == parent->lsa->hdr.adv_rtr &&
512 		    rtr_link->nbr_iface_id == parent->lsa->hdr.ls_id) {
513 			lladdr = calc_nexthop_lladdr(dst, rtr_link, ifindex);
514 			vertex_nexthop_add(dst, parent, lladdr, ifindex);
515 		}
516 	}
517 }
518 
519 void
520 calc_nexthop(struct vertex *dst, struct vertex *parent,
521     struct area *area, struct lsa_rtr_link *rtr_link)
522 {
523 	struct v_nexthop	*vn;
524 	struct in6_addr		*nexthop;
525 
526 	/* case 1 */
527 	if (parent == spf_root) {
528 		switch (dst->type) {
529 		case LSA_TYPE_ROUTER:
530 			if (rtr_link->type != LINK_TYPE_POINTTOPOINT)
531 				fatalx("inconsistent SPF tree");
532 			nexthop = calc_nexthop_lladdr(dst, rtr_link,
533 			    ntohl(rtr_link->iface_id));
534 			break;
535 		case LSA_TYPE_NETWORK:
536 			if (rtr_link->type != LINK_TYPE_TRANSIT_NET)
537 				fatalx("inconsistent SPF tree");
538 
539 			/* Next hop address cannot be determined yet,
540 			 * we only know the outgoing interface. */
541 			nexthop = NULL;
542 			break;
543 		default:
544 			fatalx("calc_nexthop: invalid dst type");
545 		}
546 
547 		vertex_nexthop_add(dst, parent, nexthop,
548 		    ntohl(rtr_link->iface_id));
549 		return;
550 	}
551 
552 	/* case 2 */
553 	if (parent->type == LSA_TYPE_NETWORK && dst->type == LSA_TYPE_ROUTER) {
554 		TAILQ_FOREACH(vn, &parent->nexthop, entry) {
555 			if (vn->prev == spf_root)
556 				calc_nexthop_transit_nbr(dst, parent,
557 				    vn->ifindex);
558 			else
559 				/* dst is more than one transit net away */
560 				vertex_nexthop_add(dst, parent, &vn->nexthop,
561 				    vn->ifindex);
562 		}
563 		return;
564 	}
565 
566 	/* case 3 */
567 	TAILQ_FOREACH(vn, &parent->nexthop, entry)
568 	    vertex_nexthop_add(dst, parent, &vn->nexthop, vn->ifindex);
569 }
570 
571 /* candidate list */
572 void
573 cand_list_init(void)
574 {
575 	TAILQ_INIT(&cand_list);
576 }
577 
578 void
579 cand_list_add(struct vertex *v)
580 {
581 	struct vertex	*c = NULL;
582 
583 	TAILQ_FOREACH(c, &cand_list, cand) {
584 		if (c->cost > v->cost) {
585 			TAILQ_INSERT_BEFORE(c, v, cand);
586 			return;
587 		} else if (c->cost == v->cost && c->type == LSA_TYPE_ROUTER &&
588 		    v->type == LSA_TYPE_NETWORK) {
589 			TAILQ_INSERT_BEFORE(c, v, cand);
590 			return;
591 		}
592 	}
593 	TAILQ_INSERT_TAIL(&cand_list, v, cand);
594 }
595 
596 struct vertex *
597 cand_list_pop(void)
598 {
599 	struct vertex	*c;
600 
601 	if ((c = TAILQ_FIRST(&cand_list)) != NULL) {
602 		TAILQ_REMOVE(&cand_list, c, cand);
603 	}
604 
605 	return (c);
606 }
607 
608 int
609 cand_list_present(struct vertex *v)
610 {
611 	struct vertex	*c;
612 
613 	TAILQ_FOREACH(c, &cand_list, cand) {
614 		if (c == v)
615 			return (1);
616 	}
617 
618 	return (0);
619 }
620 
621 void
622 cand_list_clr(void)
623 {
624 	struct vertex *c;
625 
626 	while ((c = TAILQ_FIRST(&cand_list)) != NULL) {
627 		TAILQ_REMOVE(&cand_list, c, cand);
628 	}
629 }
630 
631 /* timers */
632 /* ARGSUSED */
633 void
634 spf_timer(int fd, short event, void *arg)
635 {
636 	struct vertex		*v;
637 	struct ospfd_conf	*conf = arg;
638 	struct area		*area;
639 	struct rt_node		*r;
640 
641 	switch (conf->spf_state) {
642 	case SPF_IDLE:
643 		fatalx("spf_timer: invalid state IDLE");
644 	case SPF_HOLDQUEUE:
645 		conf->spf_state = SPF_DELAY;
646 		/* FALLTHROUGH */
647 	case SPF_DELAY:
648 		LIST_FOREACH(area, &conf->area_list, entry) {
649 			if (area->dirty) {
650 				/* invalidate RIB entries of this area */
651 				rt_invalidate(area);
652 
653 				/* calculate SPF tree */
654 				spf_calc(area);
655 
656 				/* calculate route table */
657 				RB_FOREACH(v, lsa_tree, &area->lsa_tree) {
658 					rt_calc(v, area, conf);
659 				}
660 
661 				area->dirty = 0;
662 			}
663 		}
664 
665 		/* calculate as-external routes, first invalidate them */
666 		rt_invalidate(NULL);
667 		RB_FOREACH(v, lsa_tree, &asext_tree) {
668 			asext_calc(v);
669 		}
670 
671 		RB_FOREACH(r, rt_tree, &rt) {
672 			LIST_FOREACH(area, &conf->area_list, entry)
673 				rde_summary_update(r, area);
674 
675 			if (r->d_type != DT_NET)
676 				continue;
677 
678 			if (r->invalid)
679 				rde_send_delete_kroute(r);
680 			else
681 				rde_send_change_kroute(r);
682 		}
683 
684 		LIST_FOREACH(area, &conf->area_list, entry)
685 			lsa_remove_invalid_sums(area);
686 
687 		start_spf_holdtimer(conf);
688 		break;
689 	case SPF_HOLD:
690 		conf->spf_state = SPF_IDLE;
691 		break;
692 	default:
693 		fatalx("spf_timer: unknown state");
694 	}
695 }
696 
697 void
698 start_spf_timer(void)
699 {
700 	struct timeval	tv;
701 
702 	switch (rdeconf->spf_state) {
703 	case SPF_IDLE:
704 		timerclear(&tv);
705 		tv.tv_sec = rdeconf->spf_delay;
706 		rdeconf->spf_state = SPF_DELAY;
707 		if (evtimer_add(&rdeconf->ev, &tv) == -1)
708 			fatal("start_spf_timer");
709 		break;
710 	case SPF_DELAY:
711 		/* ignore */
712 		break;
713 	case SPF_HOLD:
714 		rdeconf->spf_state = SPF_HOLDQUEUE;
715 		break;
716 	case SPF_HOLDQUEUE:
717 		/* ignore */
718 		break;
719 	default:
720 		fatalx("start_spf_timer: invalid spf_state");
721 	}
722 }
723 
724 void
725 stop_spf_timer(struct ospfd_conf *conf)
726 {
727 	if (evtimer_del(&conf->ev) == -1)
728 		fatal("stop_spf_timer");
729 }
730 
731 void
732 start_spf_holdtimer(struct ospfd_conf *conf)
733 {
734 	struct timeval	tv;
735 
736 	switch (conf->spf_state) {
737 	case SPF_DELAY:
738 		timerclear(&tv);
739 		tv.tv_sec = conf->spf_hold_time;
740 		conf->spf_state = SPF_HOLD;
741 		if (evtimer_add(&conf->ev, &tv) == -1)
742 			fatal("start_spf_holdtimer");
743 		break;
744 	case SPF_IDLE:
745 	case SPF_HOLD:
746 	case SPF_HOLDQUEUE:
747 		fatalx("start_spf_holdtimer: invalid state");
748 	default:
749 		fatalx("start_spf_holdtimer: unknown state");
750 	}
751 }
752 
753 /* route table */
754 void
755 rt_init(void)
756 {
757 	RB_INIT(&rt);
758 }
759 
760 int
761 rt_compare(struct rt_node *a, struct rt_node *b)
762 {
763 	int	i;
764 
765 	/* XXX maybe a & b need to be switched */
766 	i = memcmp(&a->prefix, &b->prefix, sizeof(a->prefix));
767 	if (i)
768 		return (i);
769 	if (a->prefixlen < b->prefixlen)
770 		return (-1);
771 	if (a->prefixlen > b->prefixlen)
772 		return (1);
773 	if (a->d_type > b->d_type)
774 		return (-1);
775 	if (a->d_type < b->d_type)
776 		return (1);
777 	return (0);
778 }
779 
780 struct rt_node *
781 rt_find(struct in6_addr *prefix, u_int8_t prefixlen, enum dst_type d_type)
782 {
783 	struct rt_node	s;
784 
785 	s.prefix = *prefix;
786 	s.prefixlen = prefixlen;
787 	s.d_type = d_type;
788 
789 	return (RB_FIND(rt_tree, &rt, &s));
790 }
791 
792 int
793 rt_insert(struct rt_node *r)
794 {
795 	if (RB_INSERT(rt_tree, &rt, r) != NULL) {
796 		log_warnx("rt_insert failed for %s/%u",
797 		    log_in6addr(&r->prefix), r->prefixlen);
798 		free(r);
799 		return (-1);
800 	}
801 
802 	return (0);
803 }
804 
805 int
806 rt_remove(struct rt_node *r)
807 {
808 	if (RB_REMOVE(rt_tree, &rt, r) == NULL) {
809 		log_warnx("rt_remove failed for %s/%u",
810 		    log_in6addr(&r->prefix), r->prefixlen);
811 		return (-1);
812 	}
813 
814 	rt_nexthop_clear(r);
815 	free(r);
816 	return (0);
817 }
818 
819 void
820 rt_invalidate(struct area *area)
821 {
822 	struct rt_node		*r, *nr;
823 	struct rt_nexthop	*rn, *nrn;
824 
825 	for (r = RB_MIN(rt_tree, &rt); r != NULL; r = nr) {
826 		nr = RB_NEXT(rt_tree, &rt, r);
827 		if (area == NULL) {
828 			/* look only at as_ext routes */
829 			if (r->p_type != PT_TYPE1_EXT &&
830 			    r->p_type != PT_TYPE2_EXT)
831 				continue;
832 		} else {
833 			/* ignore all as_ext routes */
834 			if (r->p_type == PT_TYPE1_EXT ||
835 			    r->p_type == PT_TYPE2_EXT)
836 				continue;
837 
838 			/* look only at routes matching the area */
839 			if (r->area.s_addr != area->id.s_addr)
840 				continue;
841 		}
842 		r->invalid = 1;
843 		for (rn = TAILQ_FIRST(&r->nexthop); rn != NULL; rn = nrn) {
844 			nrn = TAILQ_NEXT(rn, entry);
845 			if (rn->invalid) {
846 				TAILQ_REMOVE(&r->nexthop, rn, entry);
847 				free(rn);
848 			} else
849 				rn->invalid = 1;
850 		}
851 		if (TAILQ_EMPTY(&r->nexthop))
852 			rt_remove(r);
853 	}
854 }
855 
856 void
857 rt_nexthop_clear(struct rt_node *r)
858 {
859 	struct rt_nexthop	*rn;
860 
861 	while ((rn = TAILQ_FIRST(&r->nexthop)) != NULL) {
862 		TAILQ_REMOVE(&r->nexthop, rn, entry);
863 		free(rn);
864 	}
865 }
866 
867 void
868 rt_nexthop_add(struct rt_node *r, struct v_nexthead *vnh, u_int16_t type,
869     struct in_addr adv_rtr)
870 {
871 	struct v_nexthop	*vn;
872 	struct rt_nexthop	*rn;
873 	struct timespec		 now;
874 
875 	TAILQ_FOREACH(vn, vnh, entry) {
876 		TAILQ_FOREACH(rn, &r->nexthop, entry) {
877 			if (!IN6_ARE_ADDR_EQUAL(&rn->nexthop, &vn->nexthop))
878 				continue;
879 
880 			rn->adv_rtr.s_addr = adv_rtr.s_addr;
881 			rn->connected = (type == LSA_TYPE_NETWORK &&
882 			    vn->prev == spf_root) ||
883 			    (IN6_IS_ADDR_UNSPECIFIED(&vn->nexthop));
884 			rn->invalid = 0;
885 
886 			r->invalid = 0;
887 			break;
888 		}
889 		if (rn)
890 			continue;
891 
892 		if ((rn = calloc(1, sizeof(struct rt_nexthop))) == NULL)
893 			fatal("rt_nexthop_add");
894 
895 		clock_gettime(CLOCK_MONOTONIC, &now);
896 		rn->nexthop = vn->nexthop;
897 		rn->ifindex = vn->ifindex;
898 		rn->adv_rtr.s_addr = adv_rtr.s_addr;
899 		rn->uptime = now.tv_sec;
900 		rn->connected = (type == LSA_TYPE_NETWORK &&
901 		    vn->prev == spf_root) ||
902 		    (IN6_IS_ADDR_UNSPECIFIED(&vn->nexthop));
903 		rn->invalid = 0;
904 
905 		r->invalid = 0;
906 		TAILQ_INSERT_TAIL(&r->nexthop, rn, entry);
907 	}
908 }
909 
910 void
911 rt_clear(void)
912 {
913 	struct rt_node	*r;
914 
915 	while ((r = RB_MIN(rt_tree, &rt)) != NULL)
916 		rt_remove(r);
917 }
918 
919 void
920 rt_dump(struct in_addr area, pid_t pid, u_int8_t r_type)
921 {
922 	static struct ctl_rt	 rtctl;
923 	struct timespec		 now;
924 	struct rt_node		*r;
925 	struct rt_nexthop	*rn;
926 
927 	clock_gettime(CLOCK_MONOTONIC, &now);
928 
929 	RB_FOREACH(r, rt_tree, &rt) {
930 		if (r->invalid)
931 			continue;
932 
933 		if (r->area.s_addr != area.s_addr)
934 			continue;
935 
936 		switch (r_type) {
937 		case RIB_RTR:
938 			if (r->d_type != DT_RTR)
939 				continue;
940 			break;
941 		case RIB_NET:
942 			if (r->d_type != DT_NET)
943 				continue;
944 			if (r->p_type == PT_TYPE1_EXT ||
945 			    r->p_type == PT_TYPE2_EXT)
946 				continue;
947 			break;
948 		case RIB_EXT:
949 			if (r->p_type != PT_TYPE1_EXT &&
950 			    r->p_type != PT_TYPE2_EXT)
951 				continue;
952 			break;
953 		default:
954 			fatalx("rt_dump: invalid RIB type");
955 		}
956 
957 		memset(&rtctl, 0, sizeof(rtctl));
958 		rtctl.prefix = r->prefix;
959 		rtctl.area.s_addr = r->area.s_addr;
960 		rtctl.cost = r->cost;
961 		rtctl.cost2 = r->cost2;
962 		rtctl.p_type = r->p_type;
963 		rtctl.d_type = r->d_type;
964 		rtctl.flags = r->flags;
965 		rtctl.prefixlen = r->prefixlen;
966 
967 		TAILQ_FOREACH(rn, &r->nexthop, entry) {
968 			if (rn->invalid)
969 				continue;
970 
971 			rtctl.connected = rn->connected;
972 			rtctl.nexthop = rn->nexthop;
973 			rtctl.ifindex = rn->ifindex;
974 			rtctl.adv_rtr.s_addr = rn->adv_rtr.s_addr;
975 			rtctl.uptime = now.tv_sec - rn->uptime;
976 
977 			rde_imsg_compose_ospfe(IMSG_CTL_SHOW_RIB, 0, pid,
978 			    &rtctl, sizeof(rtctl));
979 		}
980 	}
981 }
982 
983 void
984 rt_update(struct in6_addr *prefix, u_int8_t prefixlen, struct v_nexthead *vnh,
985      u_int16_t v_type, u_int32_t cost, u_int32_t cost2, struct in_addr area,
986      struct in_addr adv_rtr, enum path_type p_type, enum dst_type d_type,
987      u_int8_t flags, u_int32_t tag)
988 {
989 	struct rt_node		*rte;
990 	struct rt_nexthop	*rn;
991 	int			 better = 0, equal = 0;
992 
993 	if (vnh == NULL || TAILQ_EMPTY(vnh))	/* XXX remove */
994 		fatalx("rt_update: invalid nexthop");
995 
996 	if ((rte = rt_find(prefix, prefixlen, d_type)) == NULL) {
997 		if ((rte = calloc(1, sizeof(struct rt_node))) == NULL)
998 			fatal("rt_update");
999 
1000 		TAILQ_INIT(&rte->nexthop);
1001 		rte->prefix = *prefix;
1002 		rte->prefixlen = prefixlen;
1003 		rte->cost = cost;
1004 		rte->cost2 = cost2;
1005 		rte->area = area;
1006 		rte->p_type = p_type;
1007 		rte->d_type = d_type;
1008 		rte->flags = flags;
1009 		rte->ext_tag = tag;
1010 
1011 		rt_nexthop_add(rte, vnh, v_type, adv_rtr);
1012 
1013 		rt_insert(rte);
1014 	} else {
1015 		/* order:
1016 		 * 1. intra-area
1017 		 * 2. inter-area
1018 		 * 3. type 1 as ext
1019 		 * 4. type 2 as ext
1020 		 */
1021 		if (rte->invalid)	/* everything is better than invalid */
1022 			better = 1;
1023 		else if (p_type < rte->p_type)
1024 			better = 1;
1025 		else if (p_type == rte->p_type)
1026 			switch (p_type) {
1027 			case PT_INTRA_AREA:
1028 			case PT_INTER_AREA:
1029 				if (cost < rte->cost)
1030 					better = 1;
1031 				else if (cost == rte->cost &&
1032 				    rte->area.s_addr == area.s_addr)
1033 					equal = 1;
1034 				break;
1035 			case PT_TYPE1_EXT:
1036 				if (cost < rte->cost)
1037 					better = 1;
1038 				else if (cost == rte->cost)
1039 					equal = 1;
1040 				break;
1041 			case PT_TYPE2_EXT:
1042 				if (cost2 < rte->cost2)
1043 					better = 1;
1044 				else if (cost2 == rte->cost2 &&
1045 				    cost < rte->cost)
1046 					better = 1;
1047 				else if (cost2 == rte->cost2 &&
1048 				    cost == rte->cost)
1049 					equal = 1;
1050 				break;
1051 			}
1052 
1053 		if (better) {
1054 			TAILQ_FOREACH(rn, &rte->nexthop, entry)
1055 				rn->invalid = 1;
1056 
1057 			rte->area = area;
1058 			rte->cost = cost;
1059 			rte->cost2 = cost2;
1060 			rte->p_type = p_type;
1061 			rte->flags = flags;
1062 			rte->ext_tag = tag;
1063 		}
1064 
1065 		if (equal || better)
1066 			rt_nexthop_add(rte, vnh, v_type, adv_rtr);
1067 	}
1068 }
1069 
1070 struct rt_node *
1071 rt_lookup(enum dst_type type, struct in6_addr *addr)
1072 {
1073 	struct rt_node	*rn;
1074 	struct in6_addr	 ina;
1075 	u_int8_t	 i = 128;
1076 
1077 	if (type == DT_RTR) {
1078 		rn = rt_find(addr, 128, type);
1079 		if (rn && rn->invalid == 0)
1080 			return (rn);
1081 		return (NULL);
1082 	}
1083 
1084 	/* type == DT_NET */
1085 	do {
1086 		inet6applymask(&ina, addr, i);
1087 		if ((rn = rt_find(&ina, i, type)) && rn->invalid == 0)
1088 			return (rn);
1089 	} while (i-- != 0);
1090 
1091 	return (NULL);
1092 }
1093 
1094 /* router LSA links */
1095 struct lsa_rtr_link *
1096 get_rtr_link(struct vertex *v, unsigned int idx)
1097 {
1098 	struct lsa_rtr_link	*rtr_link = NULL;
1099 	unsigned int		 frag = 1;
1100 	unsigned int		 frag_nlinks;
1101 	unsigned int		 nlinks = 0;
1102 	unsigned int		 i;
1103 
1104 	if (v->type != LSA_TYPE_ROUTER)
1105 		fatalx("get_rtr_link: invalid LSA type");
1106 
1107 	/* Treat multiple Router-LSAs originated by the same router
1108 	 * as an aggregate. */
1109 	do {
1110 		/* number of links validated earlier by lsa_check() */
1111 		rtr_link = (struct lsa_rtr_link *)((char *)v->lsa +
1112 		    sizeof(v->lsa->hdr) + sizeof(struct lsa_rtr));
1113 		frag_nlinks = ((ntohs(v->lsa->hdr.len) -
1114 		    sizeof(struct lsa_hdr) - sizeof(struct lsa_rtr)) /
1115 		    sizeof(struct lsa_rtr_link));
1116 		if (nlinks + frag_nlinks > idx) {
1117 			for (i = 0; i < frag_nlinks; i++) {
1118 				if (i + nlinks == idx)
1119 					return (rtr_link);
1120 				rtr_link++;
1121 			}
1122 		}
1123 		nlinks += frag_nlinks;
1124 		v = lsa_find_rtr_frag(v->area, htonl(v->adv_rtr), frag++);
1125 	} while (v);
1126 
1127 	fatalx("get_rtr_link: index not found");
1128 }
1129 
1130 /* network LSA links */
1131 struct lsa_net_link *
1132 get_net_link(struct vertex *v, unsigned int idx)
1133 {
1134 	struct lsa_net_link	*net_link = NULL;
1135 	char			*buf = (char *)v->lsa;
1136 	unsigned int		 i, nlinks;
1137 
1138 	if (v->type != LSA_TYPE_NETWORK)
1139 		fatalx("get_net_link: invalid LSA type");
1140 
1141 	net_link = (struct lsa_net_link *)(buf + sizeof(v->lsa->hdr) +
1142 	    sizeof(struct lsa_net));
1143 
1144 	/* number of links validated earlier by lsa_check() */
1145 	nlinks = lsa_num_links(v);
1146 	for (i = 0; i < nlinks; i++) {
1147 		if (i == idx)
1148 			return (net_link);
1149 		net_link++;
1150 	}
1151 
1152 	fatalx("get_net_link: index not found");
1153 }
1154 
1155 /* misc */
1156 int
1157 linked(struct vertex *w, struct vertex *v)
1158 {
1159 	struct lsa_rtr_link	*rtr_link = NULL;
1160 	struct lsa_net_link	*net_link = NULL;
1161 	unsigned int		 i;
1162 
1163 	switch (w->type) {
1164 	case LSA_TYPE_ROUTER:
1165 		for (i = 0; i < lsa_num_links(w); i++) {
1166 			rtr_link = get_rtr_link(w, i);
1167 			switch (v->type) {
1168 			case LSA_TYPE_ROUTER:
1169 				if (rtr_link->type == LINK_TYPE_POINTTOPOINT &&
1170 				    rtr_link->nbr_rtr_id == htonl(v->adv_rtr))
1171 					return (1);
1172 				break;
1173 			case LSA_TYPE_NETWORK:
1174 				if (rtr_link->type == LINK_TYPE_TRANSIT_NET &&
1175 				    rtr_link->nbr_rtr_id == htonl(v->adv_rtr) &&
1176 				    rtr_link->nbr_iface_id == htonl(v->ls_id))
1177 					return (1);
1178 				break;
1179 			default:
1180 				fatalx("linked: invalid type");
1181 			}
1182 		}
1183 		return (0);
1184 	case LSA_TYPE_NETWORK:
1185 		for (i = 0; i < lsa_num_links(w); i++) {
1186 			net_link = get_net_link(w, i);
1187 			switch (v->type) {
1188 			case LSA_TYPE_ROUTER:
1189 				if (net_link->att_rtr == htonl(v->adv_rtr))
1190 					return (1);
1191 				break;
1192 			default:
1193 				fatalx("linked: invalid type");
1194 			}
1195 		}
1196 		return (0);
1197 	default:
1198 		fatalx("linked: invalid LSA type");
1199 	}
1200 
1201 	return (0);
1202 }
1203