1 /*
2 * OSPF inter-area routing.
3 * Copyright (C) 1999, 2000 Alex Zinin, Toshiaki Takada
4 *
5 * This file is part of GNU Zebra.
6 *
7 * GNU Zebra is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2, or (at your option) any
10 * later version.
11 *
12 * GNU Zebra is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Zebra; see the file COPYING. If not, write to the Free
19 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20 * 02111-1307, USA.
21 */
22
23
24 #include <zebra.h>
25
26 #include "thread.h"
27 #include "memory.h"
28 #include "hash.h"
29 #include "linklist.h"
30 #include "prefix.h"
31 #include "table.h"
32 #include "log.h"
33
34 #include "ospfd/ospfd.h"
35 #include "ospfd/ospf_interface.h"
36 #include "ospfd/ospf_ism.h"
37 #include "ospfd/ospf_asbr.h"
38 #include "ospfd/ospf_lsa.h"
39 #include "ospfd/ospf_lsdb.h"
40 #include "ospfd/ospf_neighbor.h"
41 #include "ospfd/ospf_nsm.h"
42 #include "ospfd/ospf_spf.h"
43 #include "ospfd/ospf_route.h"
44 #include "ospfd/ospf_ase.h"
45 #include "ospfd/ospf_abr.h"
46 #include "ospfd/ospf_ia.h"
47 #include "ospfd/ospf_dump.h"
48
49 static struct ospf_route *
ospf_find_abr_route(struct route_table * rtrs,struct prefix_ipv4 * abr,struct ospf_area * area)50 ospf_find_abr_route (struct route_table *rtrs,
51 struct prefix_ipv4 *abr,
52 struct ospf_area *area)
53 {
54 struct route_node *rn;
55 struct ospf_route *or;
56 struct listnode *node;
57
58 if ((rn = route_node_lookup (rtrs, (struct prefix *) abr)) == NULL)
59 return NULL;
60
61 route_unlock_node (rn);
62
63 for (ALL_LIST_ELEMENTS_RO ((struct list *) rn->info, node, or))
64 if (IPV4_ADDR_SAME (&or->u.std.area_id, &area->area_id)
65 && (or->u.std.flags & ROUTER_LSA_BORDER))
66 return or;
67
68 return NULL;
69 }
70
71 static void
ospf_ia_network_route(struct ospf * ospf,struct route_table * rt,struct prefix_ipv4 * p,struct ospf_route * new_or,struct ospf_route * abr_or)72 ospf_ia_network_route (struct ospf *ospf, struct route_table *rt,
73 struct prefix_ipv4 *p, struct ospf_route *new_or,
74 struct ospf_route *abr_or)
75 {
76 struct route_node *rn1;
77 struct ospf_route *or;
78
79 if (IS_DEBUG_OSPF_EVENT)
80 zlog_debug ("ospf_ia_network_route(): processing summary route to %s/%d",
81 inet_ntoa (p->prefix), p->prefixlen);
82
83 /* Find a route to the same dest */
84 if ((rn1 = route_node_lookup (rt, (struct prefix *) p)))
85 {
86 int res;
87
88 route_unlock_node (rn1);
89
90 if ((or = rn1->info))
91 {
92 if (IS_DEBUG_OSPF_EVENT)
93 zlog_debug ("ospf_ia_network_route(): "
94 "Found a route to the same network");
95 /* Check the existing route. */
96 if ((res = ospf_route_cmp (ospf, new_or, or)) < 0)
97 {
98 /* New route is better, so replace old one. */
99 ospf_route_subst (rn1, new_or, abr_or);
100 }
101 else if (res == 0)
102 {
103 /* New and old route are equal, so next hops can be added. */
104 route_lock_node (rn1);
105 ospf_route_copy_nexthops (or, abr_or->paths);
106 route_unlock_node (rn1);
107
108 /* new route can be deleted, because existing route has been updated. */
109 ospf_route_free (new_or);
110 }
111 else
112 {
113 /* New route is worse, so free it. */
114 ospf_route_free (new_or);
115 return;
116 }
117 } /* if (or)*/
118 } /*if (rn1)*/
119 else
120 { /* no route */
121 if (IS_DEBUG_OSPF_EVENT)
122 zlog_debug ("ospf_ia_network_route(): add new route to %s/%d",
123 inet_ntoa (p->prefix), p->prefixlen);
124 ospf_route_add (rt, p, new_or, abr_or);
125 }
126 }
127
128 static void
ospf_ia_router_route(struct ospf * ospf,struct route_table * rtrs,struct prefix_ipv4 * p,struct ospf_route * new_or,struct ospf_route * abr_or)129 ospf_ia_router_route (struct ospf *ospf, struct route_table *rtrs,
130 struct prefix_ipv4 *p,
131 struct ospf_route *new_or, struct ospf_route *abr_or)
132 {
133 struct ospf_route *or = NULL;
134 struct route_node *rn;
135 int ret;
136
137 if (IS_DEBUG_OSPF_EVENT)
138 zlog_debug ("ospf_ia_router_route(): considering %s/%d",
139 inet_ntoa (p->prefix), p->prefixlen);
140 /* Find a route to the same dest */
141 rn = route_node_get (rtrs, (struct prefix *) p);
142
143 if (rn->info == NULL)
144 /* This is a new route */
145 rn->info = list_new ();
146 else
147 {
148 struct ospf_area *or_area;
149 or_area = ospf_area_lookup_by_area_id (ospf, new_or->u.std.area_id);
150 assert (or_area);
151 /* This is an additional route */
152 route_unlock_node (rn);
153 or = ospf_find_asbr_route_through_area (rtrs, p, or_area);
154 }
155
156 if (or)
157 {
158 if (IS_DEBUG_OSPF_EVENT)
159 zlog_debug ("ospf_ia_router_route(): "
160 "a route to the same ABR through the same area exists");
161 /* New route is better */
162 if ((ret = ospf_route_cmp (ospf, new_or, or)) < 0)
163 {
164 listnode_delete (rn->info, or);
165 ospf_route_free (or);
166 /* proceed down */
167 }
168 /* Routes are the same */
169 else if (ret == 0)
170 {
171 if (IS_DEBUG_OSPF_EVENT)
172 zlog_debug ("ospf_ia_router_route(): merging the new route");
173
174 ospf_route_copy_nexthops (or, abr_or->paths);
175 ospf_route_free (new_or);
176 return;
177 }
178 /* New route is worse */
179 else
180 {
181 if (IS_DEBUG_OSPF_EVENT)
182 zlog_debug ("ospf_ia_router_route(): skipping the new route");
183 ospf_route_free (new_or);
184 return;
185 }
186 }
187
188 ospf_route_copy_nexthops (new_or, abr_or->paths);
189
190 if (IS_DEBUG_OSPF_EVENT)
191 zlog_debug ("ospf_ia_router_route(): adding the new route");
192
193 listnode_add (rn->info, new_or);
194 }
195
196
197 static int
process_summary_lsa(struct ospf_area * area,struct route_table * rt,struct route_table * rtrs,struct ospf_lsa * lsa)198 process_summary_lsa (struct ospf_area *area, struct route_table *rt,
199 struct route_table *rtrs, struct ospf_lsa *lsa)
200 {
201 struct ospf *ospf = area->ospf;
202 struct ospf_area_range *range;
203 struct ospf_route *abr_or, *new_or;
204 struct summary_lsa *sl;
205 struct prefix_ipv4 p, abr;
206 u_int32_t metric;
207
208 if (lsa == NULL)
209 return 0;
210
211 sl = (struct summary_lsa *) lsa->data;
212
213 if (IS_DEBUG_OSPF_EVENT)
214 zlog_debug ("process_summary_lsa(): LS ID: %s", inet_ntoa (sl->header.id));
215
216 metric = GET_METRIC (sl->metric);
217
218 if (metric == OSPF_LS_INFINITY)
219 return 0;
220
221 if (IS_LSA_MAXAGE (lsa))
222 return 0;
223
224 if (ospf_lsa_is_self_originated (area->ospf, lsa))
225 return 0;
226
227 p.family = AF_INET;
228 p.prefix = sl->header.id;
229
230 if (sl->header.type == OSPF_SUMMARY_LSA)
231 p.prefixlen = ip_masklen (sl->mask);
232 else
233 p.prefixlen = IPV4_MAX_BITLEN;
234
235 apply_mask_ipv4 (&p);
236
237 if (sl->header.type == OSPF_SUMMARY_LSA &&
238 (range = ospf_area_range_match_any (ospf, &p)) &&
239 ospf_area_range_active (range))
240 return 0;
241
242 /* XXX: This check seems dubious to me. If an ABR has already decided
243 * to consider summaries received in this area, then why would one wish
244 * to exclude default?
245 */
246 if (IS_OSPF_ABR(ospf) &&
247 ospf->abr_type != OSPF_ABR_STAND &&
248 area->external_routing != OSPF_AREA_DEFAULT &&
249 p.prefix.s_addr == OSPF_DEFAULT_DESTINATION &&
250 p.prefixlen == 0)
251 return 0; /* Ignore summary default from a stub area */
252
253 abr.family = AF_INET;
254 abr.prefix = sl->header.adv_router;
255 abr.prefixlen = IPV4_MAX_BITLEN;
256 apply_mask_ipv4 (&abr);
257
258 abr_or = ospf_find_abr_route (rtrs, &abr, area);
259
260 if (abr_or == NULL)
261 return 0;
262
263 new_or = ospf_route_new ();
264 new_or->type = OSPF_DESTINATION_NETWORK;
265 new_or->id = sl->header.id;
266 new_or->mask = sl->mask;
267 new_or->u.std.options = sl->header.options;
268 new_or->u.std.origin = (struct lsa_header *) sl;
269 new_or->cost = abr_or->cost + metric;
270 new_or->u.std.area_id = area->area_id;
271 new_or->u.std.external_routing = area->external_routing;
272 new_or->path_type = OSPF_PATH_INTER_AREA;
273
274 if (sl->header.type == OSPF_SUMMARY_LSA)
275 ospf_ia_network_route (ospf, rt, &p, new_or, abr_or);
276 else
277 {
278 new_or->type = OSPF_DESTINATION_ROUTER;
279 new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
280 ospf_ia_router_route (ospf, rtrs, &p, new_or, abr_or);
281 }
282
283 return 0;
284 }
285
286 static void
ospf_examine_summaries(struct ospf_area * area,struct route_table * lsdb_rt,struct route_table * rt,struct route_table * rtrs)287 ospf_examine_summaries (struct ospf_area *area,
288 struct route_table *lsdb_rt,
289 struct route_table *rt,
290 struct route_table *rtrs)
291 {
292 struct ospf_lsa *lsa;
293 struct route_node *rn;
294
295 LSDB_LOOP (lsdb_rt, rn, lsa)
296 process_summary_lsa (area, rt, rtrs, lsa);
297 }
298
299 int
ospf_area_is_transit(struct ospf_area * area)300 ospf_area_is_transit (struct ospf_area *area)
301 {
302 return (area->transit == OSPF_TRANSIT_TRUE) ||
303 ospf_full_virtual_nbrs(area); /* Cisco forgets to set the V-bit :( */
304 }
305
306 static void
ospf_update_network_route(struct ospf * ospf,struct route_table * rt,struct route_table * rtrs,struct summary_lsa * lsa,struct prefix_ipv4 * p,struct ospf_area * area)307 ospf_update_network_route (struct ospf *ospf,
308 struct route_table *rt,
309 struct route_table *rtrs,
310 struct summary_lsa *lsa,
311 struct prefix_ipv4 *p,
312 struct ospf_area *area)
313 {
314 struct route_node *rn;
315 struct ospf_route *or, *abr_or, *new_or;
316 struct prefix_ipv4 abr;
317 u_int32_t cost;
318
319 abr.family = AF_INET;
320 abr.prefix =lsa->header.adv_router;
321 abr.prefixlen = IPV4_MAX_BITLEN;
322 apply_mask_ipv4 (&abr);
323
324 abr_or = ospf_find_abr_route (rtrs, &abr, area);
325
326 if (abr_or == NULL)
327 {
328 if (IS_DEBUG_OSPF_EVENT)
329 zlog_debug ("ospf_update_network_route(): can't find a route to the ABR");
330 return;
331 }
332
333 cost = abr_or->cost + GET_METRIC (lsa->metric);
334
335 rn = route_node_lookup (rt, (struct prefix *) p);
336
337 if (! rn)
338 {
339 if (ospf->abr_type != OSPF_ABR_SHORTCUT)
340 return; /* Standard ABR can update only already installed
341 backbone paths */
342 if (IS_DEBUG_OSPF_EVENT)
343 zlog_debug ("ospf_update_network_route(): "
344 "Allowing Shortcut ABR to add new route");
345 new_or = ospf_route_new ();
346 new_or->type = OSPF_DESTINATION_NETWORK;
347 new_or->id = lsa->header.id;
348 new_or->mask = lsa->mask;
349 new_or->u.std.options = lsa->header.options;
350 new_or->u.std.origin = (struct lsa_header *) lsa;
351 new_or->cost = cost;
352 new_or->u.std.area_id = area->area_id;
353 new_or->u.std.external_routing = area->external_routing;
354 new_or->path_type = OSPF_PATH_INTER_AREA;
355 ospf_route_add (rt, p, new_or, abr_or);
356
357 return;
358 }
359 else
360 {
361 route_unlock_node (rn);
362 if (rn->info == NULL)
363 return;
364 }
365
366 or = rn->info;
367
368 if (or->path_type != OSPF_PATH_INTRA_AREA &&
369 or->path_type != OSPF_PATH_INTER_AREA)
370 {
371 if (IS_DEBUG_OSPF_EVENT)
372 zlog_debug ("ospf_update_network_route(): ERR: path type is wrong");
373 return;
374 }
375
376 if (ospf->abr_type == OSPF_ABR_SHORTCUT)
377 {
378 if (or->path_type == OSPF_PATH_INTRA_AREA &&
379 !OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
380 {
381 if (IS_DEBUG_OSPF_EVENT)
382 zlog_debug ("ospf_update_network_route(): Shortcut: "
383 "this intra-area path is not backbone");
384 return;
385 }
386 }
387 else /* Not Shortcut ABR */
388 {
389 if (!OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
390 {
391 if (IS_DEBUG_OSPF_EVENT)
392 zlog_debug ("ospf_update_network_route(): "
393 "route is not BB-associated");
394 return; /* We can update only BB routes */
395 }
396 }
397
398 if (or->cost < cost)
399 {
400 if (IS_DEBUG_OSPF_EVENT)
401 zlog_debug ("ospf_update_network_route(): new route is worse");
402 return;
403 }
404
405 if (or->cost == cost)
406 {
407 if (IS_DEBUG_OSPF_EVENT)
408 zlog_debug ("ospf_update_network_route(): "
409 "new route is same distance, adding nexthops");
410 ospf_route_copy_nexthops (or, abr_or->paths);
411 }
412
413 if (or->cost > cost)
414 {
415 if (IS_DEBUG_OSPF_EVENT)
416 zlog_debug ("ospf_update_network_route(): "
417 "new route is better, overriding nexthops");
418 ospf_route_subst_nexthops (or, abr_or->paths);
419 or->cost = cost;
420
421 if ((ospf->abr_type == OSPF_ABR_SHORTCUT) &&
422 !OSPF_IS_AREA_ID_BACKBONE (or->u.std.area_id))
423 {
424 or->path_type = OSPF_PATH_INTER_AREA;
425 or->u.std.area_id = area->area_id;
426 or->u.std.external_routing = area->external_routing;
427 /* Note that we can do this only in Shortcut ABR mode,
428 because standard ABR must leave the route type and area
429 unchanged
430 */
431 }
432 }
433 }
434
435 static void
ospf_update_router_route(struct ospf * ospf,struct route_table * rtrs,struct summary_lsa * lsa,struct prefix_ipv4 * p,struct ospf_area * area)436 ospf_update_router_route (struct ospf *ospf,
437 struct route_table *rtrs,
438 struct summary_lsa *lsa,
439 struct prefix_ipv4 *p,
440 struct ospf_area *area)
441 {
442 struct ospf_route *or, *abr_or, *new_or;
443 struct prefix_ipv4 abr;
444 u_int32_t cost;
445
446 abr.family = AF_INET;
447 abr.prefix = lsa->header.adv_router;
448 abr.prefixlen = IPV4_MAX_BITLEN;
449 apply_mask_ipv4 (&abr);
450
451 abr_or = ospf_find_abr_route (rtrs, &abr, area);
452
453 if (abr_or == NULL)
454 {
455 if (IS_DEBUG_OSPF_EVENT)
456 zlog_debug ("ospf_update_router_route(): can't find a route to the ABR");
457 return;
458 }
459
460 cost = abr_or->cost + GET_METRIC (lsa->metric);
461
462 /* First try to find a backbone path,
463 because standard ABR can update only BB-associated paths */
464
465 if ((ospf->backbone == NULL) &&
466 (ospf->abr_type != OSPF_ABR_SHORTCUT))
467 return; /* no BB area, not Shortcut ABR, exiting */
468
469 /* find the backbone route, if possible */
470 if ((ospf->backbone == NULL)
471 || !(or = ospf_find_asbr_route_through_area (rtrs, p, ospf->backbone)))
472 {
473 if (ospf->abr_type != OSPF_ABR_SHORTCUT)
474
475 /* route to ASBR through the BB not found
476 the router is not Shortcut ABR, exiting */
477
478 return;
479 else
480 /* We're a Shortcut ABR*/
481 {
482 /* Let it either add a new router or update the route
483 through the same (non-BB) area. */
484
485 new_or = ospf_route_new ();
486 new_or->type = OSPF_DESTINATION_ROUTER;
487 new_or->id = lsa->header.id;
488 new_or->mask = lsa->mask;
489 new_or->u.std.options = lsa->header.options;
490 new_or->u.std.origin = (struct lsa_header *)lsa;
491 new_or->cost = cost;
492 new_or->u.std.area_id = area->area_id;
493 new_or->u.std.external_routing = area->external_routing;
494 new_or->path_type = OSPF_PATH_INTER_AREA;
495 new_or->u.std.flags = ROUTER_LSA_EXTERNAL;
496 ospf_ia_router_route (ospf, rtrs, p, new_or, abr_or);
497
498 return;
499 }
500 }
501
502 /* At this point the "or" is always bb-associated */
503
504 if (!(or->u.std.flags & ROUTER_LSA_EXTERNAL))
505 {
506 if (IS_DEBUG_OSPF_EVENT)
507 zlog_debug ("ospf_upd_router_route(): the remote router is not an ASBR");
508 return;
509 }
510
511 if (or->path_type != OSPF_PATH_INTRA_AREA &&
512 or->path_type != OSPF_PATH_INTER_AREA)
513 return;
514
515 if (or->cost < cost)
516 return;
517
518 else if (or->cost == cost)
519 ospf_route_copy_nexthops (or, abr_or->paths);
520
521 else if (or->cost > cost)
522 {
523 ospf_route_subst_nexthops (or, abr_or->paths);
524 or->cost = cost;
525
526 /* Even if the ABR runs in Shortcut mode, we can't change
527 the path type and area, because the "or" is always bb-associated
528 at this point and even Shortcut ABR can't change these attributes */
529 }
530 }
531
532 static int
process_transit_summary_lsa(struct ospf_area * area,struct route_table * rt,struct route_table * rtrs,struct ospf_lsa * lsa)533 process_transit_summary_lsa (struct ospf_area *area, struct route_table *rt,
534 struct route_table *rtrs, struct ospf_lsa *lsa)
535 {
536 struct ospf *ospf = area->ospf;
537 struct summary_lsa *sl;
538 struct prefix_ipv4 p;
539 u_int32_t metric;
540
541 if (lsa == NULL)
542 return 0;
543
544 sl = (struct summary_lsa *) lsa->data;
545
546 if (IS_DEBUG_OSPF_EVENT)
547 zlog_debug ("process_transit_summaries(): LS ID: %s",
548 inet_ntoa (lsa->data->id));
549 metric = GET_METRIC (sl->metric);
550
551 if (metric == OSPF_LS_INFINITY)
552 {
553 if (IS_DEBUG_OSPF_EVENT)
554 zlog_debug ("process_transit_summaries(): metric is infinity, skip");
555 return 0;
556 }
557
558 if (IS_LSA_MAXAGE (lsa))
559 {
560 if (IS_DEBUG_OSPF_EVENT)
561 zlog_debug ("process_transit_summaries(): This LSA is too old");
562 return 0;
563 }
564
565 if (ospf_lsa_is_self_originated (area->ospf, lsa))
566 {
567 if (IS_DEBUG_OSPF_EVENT)
568 zlog_debug ("process_transit_summaries(): This LSA is mine, skip");
569 return 0;
570 }
571
572 p.family = AF_INET;
573 p.prefix = sl->header.id;
574
575 if (sl->header.type == OSPF_SUMMARY_LSA)
576 p.prefixlen = ip_masklen (sl->mask);
577 else
578 p.prefixlen = IPV4_MAX_BITLEN;
579
580 apply_mask_ipv4 (&p);
581
582 if (sl->header.type == OSPF_SUMMARY_LSA)
583 ospf_update_network_route (ospf, rt, rtrs, sl, &p, area);
584 else
585 ospf_update_router_route (ospf, rtrs, sl, &p, area);
586
587 return 0;
588 }
589
590 static void
ospf_examine_transit_summaries(struct ospf_area * area,struct route_table * lsdb_rt,struct route_table * rt,struct route_table * rtrs)591 ospf_examine_transit_summaries (struct ospf_area *area,
592 struct route_table *lsdb_rt,
593 struct route_table *rt,
594 struct route_table *rtrs)
595 {
596 struct ospf_lsa *lsa;
597 struct route_node *rn;
598
599 LSDB_LOOP (lsdb_rt, rn, lsa)
600 process_transit_summary_lsa (area, rt, rtrs, lsa);
601 }
602
603 void
ospf_ia_routing(struct ospf * ospf,struct route_table * rt,struct route_table * rtrs)604 ospf_ia_routing (struct ospf *ospf,
605 struct route_table *rt,
606 struct route_table *rtrs)
607 {
608 struct ospf_area * area;
609
610 if (IS_DEBUG_OSPF_EVENT)
611 zlog_debug ("ospf_ia_routing():start");
612
613 if (IS_OSPF_ABR (ospf))
614 {
615 struct listnode *node;
616 struct ospf_area *area;
617
618 switch (ospf->abr_type)
619 {
620 case OSPF_ABR_STAND:
621 if (IS_DEBUG_OSPF_EVENT)
622 zlog_debug ("ospf_ia_routing():Standard ABR");
623
624 if ((area = ospf->backbone))
625 {
626 struct listnode *node;
627
628 if (IS_DEBUG_OSPF_EVENT)
629 {
630 zlog_debug ("ospf_ia_routing():backbone area found");
631 zlog_debug ("ospf_ia_routing():examining summaries");
632 }
633
634 OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
635
636 for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
637 if (area != ospf->backbone)
638 if (ospf_area_is_transit (area))
639 OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
640 }
641 else
642 if (IS_DEBUG_OSPF_EVENT)
643 zlog_debug ("ospf_ia_routing():backbone area NOT found");
644 break;
645 case OSPF_ABR_IBM:
646 case OSPF_ABR_CISCO:
647 if (IS_DEBUG_OSPF_EVENT)
648 zlog_debug ("ospf_ia_routing():Alternative Cisco/IBM ABR");
649 area = ospf->backbone; /* Find the BB */
650
651 /* If we have an active BB connection */
652 if (area && ospf_act_bb_connection (ospf))
653 {
654 if (IS_DEBUG_OSPF_EVENT)
655 {
656 zlog_debug ("ospf_ia_routing(): backbone area found");
657 zlog_debug ("ospf_ia_routing(): examining BB summaries");
658 }
659
660 OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
661
662 for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
663 if (area != ospf->backbone)
664 if (ospf_area_is_transit (area))
665 OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
666 }
667 else
668 { /* No active BB connection--consider all areas */
669 if (IS_DEBUG_OSPF_EVENT)
670 zlog_debug ("ospf_ia_routing(): "
671 "Active BB connection not found");
672 for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
673 OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
674 }
675 break;
676 case OSPF_ABR_SHORTCUT:
677 if (IS_DEBUG_OSPF_EVENT)
678 zlog_debug ("ospf_ia_routing():Alternative Shortcut");
679 area = ospf->backbone; /* Find the BB */
680
681 /* If we have an active BB connection */
682 if (area && ospf_act_bb_connection (ospf))
683 {
684 if (IS_DEBUG_OSPF_EVENT)
685 {
686 zlog_debug ("ospf_ia_routing(): backbone area found");
687 zlog_debug ("ospf_ia_routing(): examining BB summaries");
688 }
689 OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
690 }
691
692 for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
693 if (area != ospf->backbone)
694 if (ospf_area_is_transit (area) ||
695 ((area->shortcut_configured != OSPF_SHORTCUT_DISABLE) &&
696 ((ospf->backbone == NULL) ||
697 ((area->shortcut_configured == OSPF_SHORTCUT_ENABLE) &&
698 area->shortcut_capability))))
699 OSPF_EXAMINE_TRANSIT_SUMMARIES_ALL (area, rt, rtrs);
700 break;
701 default:
702 break;
703 }
704 }
705 else
706 {
707 struct listnode *node;
708
709 if (IS_DEBUG_OSPF_EVENT)
710 zlog_debug ("ospf_ia_routing():not ABR, considering all areas");
711
712 for (ALL_LIST_ELEMENTS_RO (ospf->areas, node, area))
713 OSPF_EXAMINE_SUMMARIES_ALL (area, rt, rtrs);
714 }
715 }
716