]>
git.proxmox.com Git - mirror_frr.git/blob - ospfd/ospf_ase.c
2 * OSPF AS external route calculation.
3 * Copyright (C) 1999, 2000 Alex Zinin, Toshiaki Takada
5 * This file is part of GNU Zebra.
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
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.
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
35 #include "ospfd/ospfd.h"
36 #include "ospfd/ospf_interface.h"
37 #include "ospfd/ospf_ism.h"
38 #include "ospfd/ospf_asbr.h"
39 #include "ospfd/ospf_lsa.h"
40 #include "ospfd/ospf_lsdb.h"
41 #include "ospfd/ospf_neighbor.h"
42 #include "ospfd/ospf_nsm.h"
43 #include "ospfd/ospf_spf.h"
44 #include "ospfd/ospf_route.h"
45 #include "ospfd/ospf_ase.h"
46 #include "ospfd/ospf_zebra.h"
47 #include "ospfd/ospf_dump.h"
50 ospf_find_asbr_route (struct ospf
*ospf
,
51 struct route_table
*rtrs
, struct prefix_ipv4
*asbr
)
53 struct route_node
*rn
;
54 struct ospf_route
*or, *best
= NULL
;
55 struct listnode
*node
;
62 rn
= route_node_lookup (rtrs
, (struct prefix
*) asbr
);
66 route_unlock_node (rn
);
70 /* First try to find intra-area non-bb paths. */
71 if (!CHECK_FLAG (ospf
->config
, OSPF_RFC1583_COMPATIBLE
))
72 for (ALL_LIST_ELEMENTS_RO ((struct list
*) rn
->info
, node
, or))
73 if (or->cost
< OSPF_LS_INFINITY
)
74 if (!OSPF_IS_AREA_ID_BACKBONE (or->u
.std
.area_id
) &&
75 or->path_type
== OSPF_PATH_INTRA_AREA
)
76 listnode_add (chosen
, or);
78 /* If none is found -- look through all. */
79 if (listcount (chosen
) == 0)
85 /* Now find the route with least cost. */
86 for (ALL_LIST_ELEMENTS_RO (chosen
, node
, or))
87 if (or->cost
< OSPF_LS_INFINITY
)
91 else if (best
->cost
> or->cost
)
93 else if (best
->cost
== or->cost
&&
94 IPV4_ADDR_CMP (&best
->u
.std
.area_id
,
95 &or->u
.std
.area_id
) < 0)
99 if (chosen
!= rn
->info
)
100 list_delete (chosen
);
106 ospf_find_asbr_route_through_area (struct route_table
*rtrs
,
107 struct prefix_ipv4
*asbr
,
108 struct ospf_area
*area
)
110 struct route_node
*rn
;
116 rn
= route_node_lookup (rtrs
, (struct prefix
*) asbr
);
120 struct listnode
*node
;
121 struct ospf_route
*or;
123 route_unlock_node (rn
);
125 for (ALL_LIST_ELEMENTS_RO ((struct list
*) rn
->info
, node
, or))
126 if (IPV4_ADDR_SAME (&or->u
.std
.area_id
, &area
->area_id
))
134 ospf_ase_complete_direct_routes (struct ospf_route
*ro
, struct in_addr nexthop
)
136 struct listnode
*node
;
137 struct ospf_path
*op
;
139 for (ALL_LIST_ELEMENTS_RO (ro
->paths
, node
, op
))
140 if (op
->nexthop
.s_addr
== 0)
141 op
->nexthop
.s_addr
= nexthop
.s_addr
;
145 ospf_ase_forward_address_check (struct ospf
*ospf
, struct in_addr fwd_addr
)
147 struct listnode
*ifn
;
148 struct ospf_interface
*oi
;
150 for (ALL_LIST_ELEMENTS_RO (ospf
->oiflist
, ifn
, oi
))
151 if (if_is_operative (oi
->ifp
))
152 if (oi
->type
!= OSPF_IFTYPE_VIRTUALLINK
)
153 if (IPV4_ADDR_SAME (&oi
->address
->u
.prefix4
, &fwd_addr
))
160 /* Calculate ASBR route. */
161 static struct ospf_route
*
162 ospf_ase_calculate_asbr_route (struct ospf
*ospf
,
163 struct route_table
*rt_network
,
164 struct route_table
*rt_router
,
165 struct as_external_lsa
*al
)
167 struct prefix_ipv4 asbr
;
168 struct ospf_route
*asbr_route
;
169 struct route_node
*rn
;
171 /* Find ASBR route from Router routing table. */
172 asbr
.family
= AF_INET
;
173 asbr
.prefix
= al
->header
.adv_router
;
174 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
175 apply_mask_ipv4 (&asbr
);
177 asbr_route
= ospf_find_asbr_route (ospf
, rt_router
, &asbr
);
179 if (asbr_route
== NULL
)
181 if (IS_DEBUG_OSPF (lsa
, LSA
))
182 zlog_debug ("ospf_ase_calculate(): Route to ASBR %s not found",
183 inet_ntoa (asbr
.prefix
));
187 if (!(asbr_route
->u
.std
.flags
& ROUTER_LSA_EXTERNAL
))
189 if (IS_DEBUG_OSPF (lsa
, LSA
))
190 zlog_debug ("ospf_ase_calculate(): Originating router is not an ASBR");
194 if (al
->e
[0].fwd_addr
.s_addr
!= 0)
196 if (IS_DEBUG_OSPF (lsa
, LSA
))
197 zlog_debug ("ospf_ase_calculate(): "
198 "Forwarding address is not 0.0.0.0.");
200 if (! ospf_ase_forward_address_check (ospf
, al
->e
[0].fwd_addr
))
202 if (IS_DEBUG_OSPF (lsa
, LSA
))
203 zlog_debug ("ospf_ase_calculate(): "
204 "Forwarding address is one of our addresses, Ignore.");
208 if (IS_DEBUG_OSPF (lsa
, LSA
))
209 zlog_debug ("ospf_ase_calculate(): "
210 "Looking up in the Network Routing Table.");
212 /* Looking up the path to the fwd_addr from Network route. */
213 asbr
.family
= AF_INET
;
214 asbr
.prefix
= al
->e
[0].fwd_addr
;
215 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
217 rn
= route_node_match (rt_network
, (struct prefix
*) &asbr
);
221 if (IS_DEBUG_OSPF (lsa
, LSA
))
222 zlog_debug ("ospf_ase_calculate(): "
223 "Couldn't find a route to the forwarding address.");
227 route_unlock_node (rn
);
229 if ((asbr_route
= rn
->info
) == NULL
)
231 if (IS_DEBUG_OSPF (lsa
, LSA
))
232 zlog_debug ("ospf_ase_calculate(): "
233 "Somehow OSPF route to ASBR is lost");
242 static struct ospf_route
*
243 ospf_ase_calculate_new_route (struct ospf_lsa
*lsa
,
244 struct ospf_route
*asbr_route
, u_int32_t metric
)
246 struct as_external_lsa
*al
;
247 struct ospf_route
*new;
249 al
= (struct as_external_lsa
*) lsa
->data
;
251 new = ospf_route_new ();
253 /* Set redistributed type -- does make sense? */
254 /* new->type = type; */
255 new->id
= al
->header
.id
;
256 new->mask
= al
->mask
;
258 if (!IS_EXTERNAL_METRIC (al
->e
[0].tos
))
260 if (IS_DEBUG_OSPF (lsa
, LSA
))
261 zlog_debug ("Route[External]: type-1 created.");
262 new->path_type
= OSPF_PATH_TYPE1_EXTERNAL
;
263 new->cost
= asbr_route
->cost
+ metric
; /* X + Y */
267 if (IS_DEBUG_OSPF (lsa
, LSA
))
268 zlog_debug ("Route[External]: type-2 created.");
269 new->path_type
= OSPF_PATH_TYPE2_EXTERNAL
;
270 new->cost
= asbr_route
->cost
; /* X */
271 new->u
.ext
.type2_cost
= metric
; /* Y */
274 new->type
= OSPF_DESTINATION_NETWORK
;
275 new->u
.ext
.origin
= lsa
;
276 new->u
.ext
.tag
= ntohl (al
->e
[0].route_tag
);
277 new->u
.ext
.asbr
= asbr_route
;
279 assert (new != asbr_route
);
284 #define OSPF_ASE_CALC_INTERVAL 1
287 ospf_ase_calculate_route (struct ospf
*ospf
, struct ospf_lsa
* lsa
)
290 struct as_external_lsa
*al
;
291 struct ospf_route
*asbr_route
;
292 struct prefix_ipv4 asbr
, p
;
293 struct route_node
*rn
;
294 struct ospf_route
*new, *or;
298 al
= (struct as_external_lsa
*) lsa
->data
;
300 if (lsa
->data
->type
== OSPF_AS_NSSA_LSA
)
301 if (IS_DEBUG_OSPF_NSSA
)
302 zlog_debug ("ospf_ase_calc(): Processing Type-7");
304 /* Stay away from any Local Translated Type-7 LSAs */
305 if (CHECK_FLAG (lsa
->flags
, OSPF_LSA_LOCAL_XLT
))
307 if (IS_DEBUG_OSPF_NSSA
)
308 zlog_debug ("ospf_ase_calc(): Rejecting Local Xlt'd");
312 if (IS_DEBUG_OSPF (lsa
, LSA
))
313 zlog_debug ("Route[External]: Calculate AS-external-LSA to %s/%d",
314 inet_ntoa (al
->header
.id
), ip_masklen (al
->mask
));
315 /* (1) If the cost specified by the LSA is LSInfinity, or if the
316 LSA's LS age is equal to MaxAge, then examine the next LSA. */
317 if ((metric
= GET_METRIC (al
->e
[0].metric
)) >= OSPF_LS_INFINITY
)
319 if (IS_DEBUG_OSPF (lsa
, LSA
))
320 zlog_debug ("Route[External]: Metric is OSPF_LS_INFINITY");
323 if (IS_LSA_MAXAGE (lsa
))
325 if (IS_DEBUG_OSPF (lsa
, LSA
))
326 zlog_debug ("Route[External]: AS-external-LSA is MAXAGE");
330 /* (2) If the LSA was originated by the calculating router itself,
331 examine the next LSA. */
332 if (IS_LSA_SELF (lsa
))
334 if (IS_DEBUG_OSPF (lsa
, LSA
))
335 zlog_debug ("Route[External]: AS-external-LSA is self originated");
339 /* (3) Call the destination described by the LSA N. N's address is
340 obtained by masking the LSA's Link State ID with the
341 network/subnet mask contained in the body of the LSA. Look
342 up the routing table entries (potentially one per attached
343 area) for the AS boundary router (ASBR) that originated the
344 LSA. If no entries exist for router ASBR (i.e., ASBR is
345 unreachable), do nothing with this LSA and consider the next
348 asbr
.family
= AF_INET
;
349 asbr
.prefix
= al
->header
.adv_router
;
350 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
351 apply_mask_ipv4 (&asbr
);
353 asbr_route
= ospf_find_asbr_route (ospf
, ospf
->new_rtrs
, &asbr
);
354 if (asbr_route
== NULL
)
356 if (IS_DEBUG_OSPF (lsa
, LSA
))
357 zlog_debug ("Route[External]: Can't find originating ASBR route");
360 if (!(asbr_route
->u
.std
.flags
& ROUTER_LSA_EXTERNAL
))
362 if (IS_DEBUG_OSPF (lsa
, LSA
))
363 zlog_debug ("Route[External]: Originating router is not an ASBR");
367 /* Else, this LSA describes an AS external path to destination
368 N. Examine the forwarding address specified in the AS-
369 external-LSA. This indicates the IP address to which
370 packets for the destination should be forwarded. */
372 if (al
->e
[0].fwd_addr
.s_addr
== 0)
374 /* If the forwarding address is set to 0.0.0.0, packets should
375 be sent to the ASBR itself. Among the multiple routing table
376 entries for the ASBR, select the preferred entry as follows.
377 If RFC1583Compatibility is set to "disabled", prune the set
378 of routing table entries for the ASBR as described in
379 Section 16.4.1. In any case, among the remaining routing
380 table entries, select the routing table entry with the least
381 cost; when there are multiple least cost routing table
382 entries the entry whose associated area has the largest OSPF
383 Area ID (when considered as an unsigned 32-bit integer) is
386 /* asbr_route already contains the requested route */
390 /* If the forwarding address is non-zero, look up the
391 forwarding address in the routing table.[24] The matching
392 routing table entry must specify an intra-area or inter-area
393 path; if no such path exists, do nothing with the LSA and
394 consider the next in the list. */
395 if (! ospf_ase_forward_address_check (ospf
, al
->e
[0].fwd_addr
))
397 if (IS_DEBUG_OSPF (lsa
, LSA
))
398 zlog_debug ("Route[External]: Forwarding address is our router "
403 asbr
.family
= AF_INET
;
404 asbr
.prefix
= al
->e
[0].fwd_addr
;
405 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
407 rn
= route_node_match (ospf
->new_table
, (struct prefix
*) &asbr
);
409 if (rn
== NULL
|| (asbr_route
= rn
->info
) == NULL
)
411 if (IS_DEBUG_OSPF (lsa
, LSA
))
412 zlog_debug ("Route[External]: Can't find route to forwarding "
415 route_unlock_node (rn
);
419 route_unlock_node (rn
);
422 /* (4) Let X be the cost specified by the preferred routing table
423 entry for the ASBR/forwarding address, and Y the cost
424 specified in the LSA. X is in terms of the link state
425 metric, and Y is a type 1 or 2 external metric. */
428 /* (5) Look up the routing table entry for the destination N. If
429 no entry exists for N, install the AS external path to N,
430 with next hop equal to the list of next hops to the
431 forwarding address, and advertising router equal to ASBR.
432 If the external metric type is 1, then the path-type is set
433 to type 1 external and the cost is equal to X+Y. If the
434 external metric type is 2, the path-type is set to type 2
435 external, the link state component of the route's cost is X,
436 and the type 2 cost is Y. */
437 new = ospf_ase_calculate_new_route (lsa
, asbr_route
, metric
);
439 /* (6) Compare the AS external path described by the LSA with the
440 existing paths in N's routing table entry, as follows. If
441 the new path is preferred, it replaces the present paths in
442 N's routing table entry. If the new path is of equal
443 preference, it is added to N's routing table entry's list of
448 p
.prefix
= al
->header
.id
;
449 p
.prefixlen
= ip_masklen (al
->mask
);
451 /* if there is a Intra/Inter area route to the N
452 do not install external route */
453 if ((rn
= route_node_lookup (ospf
->new_table
,
454 (struct prefix
*) &p
)))
456 route_unlock_node(rn
);
457 if (rn
->info
== NULL
)
458 zlog_info ("Route[External]: rn->info NULL");
460 ospf_route_free (new);
463 /* Find a route to the same dest */
464 /* If there is no route, create new one. */
465 if ((rn
= route_node_lookup (ospf
->new_external_route
,
466 (struct prefix
*) &p
)))
467 route_unlock_node(rn
);
469 if (!rn
|| (or = rn
->info
) == NULL
)
471 if (IS_DEBUG_OSPF (lsa
, LSA
))
472 zlog_debug ("Route[External]: Adding a new route %s/%d",
473 inet_ntoa (p
.prefix
), p
.prefixlen
);
475 ospf_route_add (ospf
->new_external_route
, &p
, new, asbr_route
);
477 if (al
->e
[0].fwd_addr
.s_addr
)
478 ospf_ase_complete_direct_routes (new, al
->e
[0].fwd_addr
);
483 /* (a) Intra-area and inter-area paths are always preferred
484 over AS external paths.
486 (b) Type 1 external paths are always preferred over type 2
487 external paths. When all paths are type 2 external
488 paths, the paths with the smallest advertised type 2
489 metric are always preferred. */
490 ret
= ospf_route_cmp (ospf
, new, or);
492 /* (c) If the new AS external path is still indistinguishable
493 from the current paths in the N's routing table entry,
494 and RFC1583Compatibility is set to "disabled", select
495 the preferred paths based on the intra-AS paths to the
496 ASBR/forwarding addresses, as specified in Section
499 (d) If the new AS external path is still indistinguishable
500 from the current paths in the N's routing table entry,
501 select the preferred path based on a least cost
502 comparison. Type 1 external paths are compared by
503 looking at the sum of the distance to the forwarding
504 address and the advertised type 1 metric (X+Y). Type 2
505 external paths advertising equal type 2 metrics are
506 compared by looking at the distance to the forwarding
509 /* New route is better */
512 if (IS_DEBUG_OSPF (lsa
, LSA
))
513 zlog_debug ("Route[External]: New route is better");
514 ospf_route_subst (rn
, new, asbr_route
);
515 if (al
->e
[0].fwd_addr
.s_addr
)
516 ospf_ase_complete_direct_routes (new, al
->e
[0].fwd_addr
);
520 /* Old route is better */
523 if (IS_DEBUG_OSPF (lsa
, LSA
))
524 zlog_debug ("Route[External]: Old route is better");
527 /* Routes are equal */
530 if (IS_DEBUG_OSPF (lsa
, LSA
))
531 zlog_debug ("Route[External]: Routes are equal");
532 ospf_route_copy_nexthops (or, asbr_route
->paths
);
533 if (al
->e
[0].fwd_addr
.s_addr
)
534 ospf_ase_complete_direct_routes (or, al
->e
[0].fwd_addr
);
537 /* Make sure setting newly calculated ASBR route.*/
538 or->u
.ext
.asbr
= asbr_route
;
540 ospf_route_free (new);
547 ospf_ase_route_match_same (struct route_table
*rt
, struct prefix
*prefix
,
548 struct ospf_route
*newor
)
550 struct route_node
*rn
;
551 struct ospf_route
*or;
552 struct ospf_path
*op
;
553 struct ospf_path
*newop
;
557 if (! rt
|| ! prefix
)
560 rn
= route_node_lookup (rt
, prefix
);
564 route_unlock_node (rn
);
567 if (or->path_type
!= newor
->path_type
)
570 switch (or->path_type
)
572 case OSPF_PATH_TYPE1_EXTERNAL
:
573 if (or->cost
!= newor
->cost
)
576 case OSPF_PATH_TYPE2_EXTERNAL
:
577 if ((or->cost
!= newor
->cost
) ||
578 (or->u
.ext
.type2_cost
!= newor
->u
.ext
.type2_cost
))
586 if (or->paths
->count
!= newor
->paths
->count
)
589 /* Check each path. */
590 for (n1
= listhead (or->paths
), n2
= listhead (newor
->paths
);
591 n1
&& n2
; n1
= listnextnode (n1
), n2
= listnextnode (n2
))
593 op
= listgetdata (n1
);
594 newop
= listgetdata (n2
);
596 if (! IPV4_ADDR_SAME (&op
->nexthop
, &newop
->nexthop
))
598 if (op
->ifindex
!= newop
->ifindex
)
605 ospf_ase_compare_tables (struct route_table
*new_external_route
,
606 struct route_table
*old_external_route
)
608 struct route_node
*rn
, *new_rn
;
609 struct ospf_route
*or;
611 /* Remove deleted routes */
612 for (rn
= route_top (old_external_route
); rn
; rn
= route_next (rn
))
615 if (! (new_rn
= route_node_lookup (new_external_route
, &rn
->p
)))
616 ospf_zebra_delete ((struct prefix_ipv4
*) &rn
->p
, or);
618 route_unlock_node (new_rn
);
622 /* Install new routes */
623 for (rn
= route_top (new_external_route
); rn
; rn
= route_next (rn
))
624 if ((or = rn
->info
) != NULL
)
625 if (! ospf_ase_route_match_same (old_external_route
, &rn
->p
, or))
626 ospf_zebra_add ((struct prefix_ipv4
*) &rn
->p
, or);
632 ospf_ase_calculate_timer (struct thread
*t
)
635 struct ospf_lsa
*lsa
;
636 struct route_node
*rn
;
637 struct listnode
*node
;
638 struct ospf_area
*area
;
640 ospf
= THREAD_ARG (t
);
641 ospf
->t_ase_calc
= NULL
;
647 /* Calculate external route for each AS-external-LSA */
648 LSDB_LOOP (EXTERNAL_LSDB (ospf
), rn
, lsa
)
649 ospf_ase_calculate_route (ospf
, lsa
);
651 /* This version simple adds to the table all NSSA areas */
653 for (ALL_LIST_ELEMENTS_RO (ospf
->areas
, node
, area
))
655 if (IS_DEBUG_OSPF_NSSA
)
656 zlog_debug ("ospf_ase_calculate_timer(): looking at area %s",
657 inet_ntoa (area
->area_id
));
659 if (area
->external_routing
== OSPF_AREA_NSSA
)
660 LSDB_LOOP (NSSA_LSDB (area
), rn
, lsa
)
661 ospf_ase_calculate_route (ospf
, lsa
);
663 /* kevinm: And add the NSSA routes in ospf_top */
664 LSDB_LOOP (NSSA_LSDB (ospf
),rn
,lsa
)
665 ospf_ase_calculate_route(ospf
,lsa
);
667 /* Compare old and new external routing table and install the
668 difference info zebra/kernel */
669 ospf_ase_compare_tables (ospf
->new_external_route
,
670 ospf
->old_external_route
);
672 /* Delete old external routing table */
673 ospf_route_table_free (ospf
->old_external_route
);
674 ospf
->old_external_route
= ospf
->new_external_route
;
675 ospf
->new_external_route
= route_table_init ();
681 ospf_ase_calculate_schedule (struct ospf
*ospf
)
690 ospf_ase_calculate_timer_add (struct ospf
*ospf
)
695 if (! ospf
->t_ase_calc
)
696 ospf
->t_ase_calc
= thread_add_timer (master
, ospf_ase_calculate_timer
,
697 ospf
, OSPF_ASE_CALC_INTERVAL
);
701 ospf_ase_register_external_lsa (struct ospf_lsa
*lsa
, struct ospf
*top
)
703 struct route_node
*rn
;
704 struct prefix_ipv4 p
;
706 struct as_external_lsa
*al
;
708 al
= (struct as_external_lsa
*) lsa
->data
;
710 p
.prefix
= lsa
->data
->id
;
711 p
.prefixlen
= ip_masklen (al
->mask
);
712 apply_mask_ipv4 (&p
);
714 rn
= route_node_get (top
->external_lsas
, (struct prefix
*) &p
);
715 if ((lst
= rn
->info
) == NULL
)
716 rn
->info
= lst
= list_new();
718 /* We assume that if LSA is deleted from DB
719 is is also deleted from this RT */
720 listnode_add (lst
, ospf_lsa_lock (lsa
)); /* external_lsas lst */
724 ospf_ase_unregister_external_lsa (struct ospf_lsa
*lsa
, struct ospf
*top
)
726 struct route_node
*rn
;
727 struct prefix_ipv4 p
;
729 struct as_external_lsa
*al
;
731 al
= (struct as_external_lsa
*) lsa
->data
;
733 p
.prefix
= lsa
->data
->id
;
734 p
.prefixlen
= ip_masklen (al
->mask
);
735 apply_mask_ipv4 (&p
);
737 rn
= route_node_get (top
->external_lsas
, (struct prefix
*) &p
);
740 /* XXX lst can be NULL */
742 listnode_delete (lst
, lsa
);
743 ospf_lsa_unlock (&lsa
); /* external_lsas list */
748 ospf_ase_external_lsas_finish (struct route_table
*rt
)
750 struct route_node
*rn
;
751 struct ospf_lsa
*lsa
;
753 struct listnode
*node
, *nnode
;
755 for (rn
= route_top (rt
); rn
; rn
= route_next (rn
))
756 if ((lst
= rn
->info
) != NULL
)
758 for (ALL_LIST_ELEMENTS (lst
, node
, nnode
, lsa
))
759 ospf_lsa_unlock (&lsa
); /* external_lsas lst */
763 route_table_finish (rt
);
767 ospf_ase_incremental_update (struct ospf
*ospf
, struct ospf_lsa
*lsa
)
770 struct listnode
*node
;
771 struct route_node
*rn
, *rn2
;
772 struct prefix_ipv4 p
;
773 struct route_table
*tmp_old
;
774 struct as_external_lsa
*al
;
776 al
= (struct as_external_lsa
*) lsa
->data
;
778 p
.prefix
= lsa
->data
->id
;
779 p
.prefixlen
= ip_masklen (al
->mask
);
780 apply_mask_ipv4 (&p
);
782 /* if new_table is NULL, there was no spf calculation, thus
783 incremental update is unneeded */
784 if (!ospf
->new_table
)
787 /* If there is already an intra-area or inter-area route
788 to the destination, no recalculation is necessary
789 (internal routes take precedence). */
791 rn
= route_node_lookup (ospf
->new_table
, (struct prefix
*) &p
);
794 route_unlock_node (rn
);
799 rn
= route_node_lookup (ospf
->external_lsas
, (struct prefix
*) &p
);
803 route_unlock_node (rn
);
805 for (ALL_LIST_ELEMENTS_RO (lsas
, node
, lsa
))
806 ospf_ase_calculate_route (ospf
, lsa
);
808 /* prepare temporary old routing table for compare */
809 tmp_old
= route_table_init ();
810 rn
= route_node_lookup (ospf
->old_external_route
, (struct prefix
*) &p
);
813 rn2
= route_node_get (tmp_old
, (struct prefix
*) &p
);
814 rn2
->info
= rn
->info
;
817 /* install changes to zebra */
818 ospf_ase_compare_tables (ospf
->new_external_route
, tmp_old
);
820 /* update ospf->old_external_route table */
822 ospf_route_free ((struct ospf_route
*) rn
->info
);
824 rn2
= route_node_lookup (ospf
->new_external_route
, (struct prefix
*) &p
);
825 /* if new route exists, install it to ospf->old_external_route */
826 if (rn2
&& rn2
->info
)
829 rn
= route_node_get (ospf
->old_external_route
, (struct prefix
*) &p
);
830 rn
->info
= rn2
->info
;
834 /* remove route node from ospf->old_external_route */
838 route_unlock_node (rn
);
839 route_unlock_node (rn
);
845 /* rn2->info is stored in route node of ospf->old_external_route */
847 route_unlock_node (rn2
);
848 route_unlock_node (rn2
);
851 route_table_finish (tmp_old
);