]>
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"
52 ospf_find_asbr_route (struct ospf
*ospf
,
53 struct route_table
*rtrs
, struct prefix_ipv4
*asbr
)
55 struct route_node
*rn
;
56 struct ospf_route
*or, *best
= NULL
;
57 struct listnode
*node
;
64 rn
= route_node_lookup (rtrs
, (struct prefix
*) asbr
);
68 route_unlock_node (rn
);
72 /* First try to find intra-area non-bb paths. */
73 if (!CHECK_FLAG (ospf
->config
, OSPF_RFC1583_COMPATIBLE
))
74 for (ALL_LIST_ELEMENTS_RO ((struct list
*) rn
->info
, node
, or))
75 if (or->cost
< OSPF_LS_INFINITY
)
76 if (!OSPF_IS_AREA_ID_BACKBONE (or->u
.std
.area_id
) &&
77 or->path_type
== OSPF_PATH_INTRA_AREA
)
78 listnode_add (chosen
, or);
80 /* If none is found -- look through all. */
81 if (listcount (chosen
) == 0)
87 /* Now find the route with least cost. */
88 for (ALL_LIST_ELEMENTS_RO (chosen
, node
, or))
89 if (or->cost
< OSPF_LS_INFINITY
)
93 else if (best
->cost
> or->cost
)
95 else if (best
->cost
== or->cost
&&
96 IPV4_ADDR_CMP (&best
->u
.std
.area_id
,
97 &or->u
.std
.area_id
) < 0)
101 if (chosen
!= rn
->info
)
102 list_delete (chosen
);
108 ospf_find_asbr_route_through_area (struct route_table
*rtrs
,
109 struct prefix_ipv4
*asbr
,
110 struct ospf_area
*area
)
112 struct route_node
*rn
;
118 rn
= route_node_lookup (rtrs
, (struct prefix
*) asbr
);
122 struct listnode
*node
;
123 struct ospf_route
*or;
125 route_unlock_node (rn
);
127 for (ALL_LIST_ELEMENTS_RO ((struct list
*) rn
->info
, node
, or))
128 if (IPV4_ADDR_SAME (&or->u
.std
.area_id
, &area
->area_id
))
136 ospf_ase_complete_direct_routes (struct ospf_route
*ro
, struct in_addr nexthop
)
138 struct listnode
*node
;
139 struct ospf_path
*op
;
141 for (ALL_LIST_ELEMENTS_RO (ro
->paths
, node
, op
))
142 if (op
->nexthop
.s_addr
== 0)
143 op
->nexthop
.s_addr
= nexthop
.s_addr
;
147 ospf_ase_forward_address_check (struct ospf
*ospf
, struct in_addr fwd_addr
)
149 struct listnode
*ifn
;
150 struct ospf_interface
*oi
;
152 for (ALL_LIST_ELEMENTS_RO (ospf
->oiflist
, ifn
, oi
))
153 if (if_is_operative (oi
->ifp
))
154 if (oi
->type
!= OSPF_IFTYPE_VIRTUALLINK
)
155 if (IPV4_ADDR_SAME (&oi
->address
->u
.prefix4
, &fwd_addr
))
161 /* Calculate ASBR route. */
162 static struct ospf_route
*
163 ospf_ase_calculate_asbr_route (struct ospf
*ospf
,
164 struct route_table
*rt_network
,
165 struct route_table
*rt_router
,
166 struct as_external_lsa
*al
)
168 struct prefix_ipv4 asbr
;
169 struct ospf_route
*asbr_route
;
170 struct route_node
*rn
;
172 /* Find ASBR route from Router routing table. */
173 asbr
.family
= AF_INET
;
174 asbr
.prefix
= al
->header
.adv_router
;
175 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
176 apply_mask_ipv4 (&asbr
);
178 asbr_route
= ospf_find_asbr_route (ospf
, rt_router
, &asbr
);
180 if (asbr_route
== NULL
)
182 if (IS_DEBUG_OSPF (lsa
, LSA
))
183 zlog_debug ("ospf_ase_calculate(): Route to ASBR %s not found",
184 inet_ntoa (asbr
.prefix
));
188 if (!(asbr_route
->u
.std
.flags
& ROUTER_LSA_EXTERNAL
))
190 if (IS_DEBUG_OSPF (lsa
, LSA
))
191 zlog_debug ("ospf_ase_calculate(): Originating router is not an ASBR");
195 if (al
->e
[0].fwd_addr
.s_addr
!= 0)
197 if (IS_DEBUG_OSPF (lsa
, LSA
))
198 zlog_debug ("ospf_ase_calculate(): "
199 "Forwarding address is not 0.0.0.0.");
201 if (! ospf_ase_forward_address_check (ospf
, al
->e
[0].fwd_addr
))
203 if (IS_DEBUG_OSPF (lsa
, LSA
))
204 zlog_debug ("ospf_ase_calculate(): "
205 "Forwarding address is one of our addresses, Ignore.");
209 if (IS_DEBUG_OSPF (lsa
, LSA
))
210 zlog_debug ("ospf_ase_calculate(): "
211 "Looking up in the Network Routing Table.");
213 /* Looking up the path to the fwd_addr from Network route. */
214 asbr
.family
= AF_INET
;
215 asbr
.prefix
= al
->e
[0].fwd_addr
;
216 asbr
.prefixlen
= IPV4_MAX_BITLEN
;
218 rn
= route_node_match (rt_network
, (struct prefix
*) &asbr
);
222 if (IS_DEBUG_OSPF (lsa
, LSA
))
223 zlog_debug ("ospf_ase_calculate(): "
224 "Couldn't find a route to the forwarding address.");
228 route_unlock_node (rn
);
230 if ((asbr_route
= rn
->info
) == NULL
)
232 if (IS_DEBUG_OSPF (lsa
, LSA
))
233 zlog_debug ("ospf_ase_calculate(): "
234 "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
)) != NULL
455 && (rn
->info
!= NULL
))
458 ospf_route_free (new);
462 /* Find a route to the same dest */
463 /* If there is no route, create new one. */
464 if ((rn
= route_node_lookup (ospf
->new_external_route
,
465 (struct prefix
*) &p
)) == NULL
466 || (or = rn
->info
) == NULL
)
468 if (IS_DEBUG_OSPF (lsa
, LSA
))
469 zlog_debug ("Route[External]: Adding a new route %s/%d",
470 inet_ntoa (p
.prefix
), p
.prefixlen
);
472 ospf_route_add (ospf
->new_external_route
, &p
, new, asbr_route
);
474 if (al
->e
[0].fwd_addr
.s_addr
)
475 ospf_ase_complete_direct_routes (new, al
->e
[0].fwd_addr
);
480 /* (a) Intra-area and inter-area paths are always preferred
481 over AS external paths.
483 (b) Type 1 external paths are always preferred over type 2
484 external paths. When all paths are type 2 external
485 paths, the paths with the smallest advertised type 2
486 metric are always preferred. */
487 ret
= ospf_route_cmp (ospf
, new, or);
489 /* (c) If the new AS external path is still indistinguishable
490 from the current paths in the N's routing table entry,
491 and RFC1583Compatibility is set to "disabled", select
492 the preferred paths based on the intra-AS paths to the
493 ASBR/forwarding addresses, as specified in Section
496 (d) If the new AS external path is still indistinguishable
497 from the current paths in the N's routing table entry,
498 select the preferred path based on a least cost
499 comparison. Type 1 external paths are compared by
500 looking at the sum of the distance to the forwarding
501 address and the advertised type 1 metric (X+Y). Type 2
502 external paths advertising equal type 2 metrics are
503 compared by looking at the distance to the forwarding
506 /* New route is better */
509 if (IS_DEBUG_OSPF (lsa
, LSA
))
510 zlog_debug ("Route[External]: New route is better");
511 ospf_route_subst (rn
, new, asbr_route
);
512 if (al
->e
[0].fwd_addr
.s_addr
)
513 ospf_ase_complete_direct_routes (new, al
->e
[0].fwd_addr
);
517 /* Old route is better */
520 if (IS_DEBUG_OSPF (lsa
, LSA
))
521 zlog_debug ("Route[External]: Old route is better");
524 /* Routes are equal */
527 if (IS_DEBUG_OSPF (lsa
, LSA
))
528 zlog_debug ("Route[External]: Routes are equal");
529 ospf_route_copy_nexthops (or, asbr_route
->paths
);
530 if (al
->e
[0].fwd_addr
.s_addr
)
531 ospf_ase_complete_direct_routes (or, al
->e
[0].fwd_addr
);
534 /* Make sure setting newly calculated ASBR route.*/
535 or->u
.ext
.asbr
= asbr_route
;
537 ospf_route_free (new);
544 ospf_ase_route_match_same (struct route_table
*rt
, struct prefix
*prefix
,
545 struct ospf_route
*newor
)
547 struct route_node
*rn
;
548 struct ospf_route
*or;
549 struct ospf_path
*op
;
550 struct ospf_path
*newop
;
554 if (! rt
|| ! prefix
)
557 rn
= route_node_lookup (rt
, prefix
);
561 route_unlock_node (rn
);
564 if (or->path_type
!= newor
->path_type
)
567 switch (or->path_type
)
569 case OSPF_PATH_TYPE1_EXTERNAL
:
570 if (or->cost
!= newor
->cost
)
573 case OSPF_PATH_TYPE2_EXTERNAL
:
574 if ((or->cost
!= newor
->cost
) ||
575 (or->u
.ext
.type2_cost
!= newor
->u
.ext
.type2_cost
))
583 if (or->paths
->count
!= newor
->paths
->count
)
586 /* Check each path. */
587 for (n1
= listhead (or->paths
), n2
= listhead (newor
->paths
);
588 n1
&& n2
; n1
= listnextnode (n1
), n2
= listnextnode (n2
))
590 op
= listgetdata (n1
);
591 newop
= listgetdata (n2
);
593 if (! IPV4_ADDR_SAME (&op
->nexthop
, &newop
->nexthop
))
600 ospf_ase_compare_tables (struct route_table
*new_external_route
,
601 struct route_table
*old_external_route
)
603 struct route_node
*rn
, *new_rn
;
604 struct ospf_route
*or;
606 /* Remove deleted routes */
607 for (rn
= route_top (old_external_route
); rn
; rn
= route_next (rn
))
610 if (! (new_rn
= route_node_lookup (new_external_route
, &rn
->p
)))
611 ospf_zebra_delete ((struct prefix_ipv4
*) &rn
->p
, or);
613 route_unlock_node (new_rn
);
617 /* Install new routes */
618 for (rn
= route_top (new_external_route
); rn
; rn
= route_next (rn
))
619 if ((or = rn
->info
) != NULL
)
620 if (! ospf_ase_route_match_same (old_external_route
, &rn
->p
, or))
621 ospf_zebra_add ((struct prefix_ipv4
*) &rn
->p
, or);
627 ospf_ase_calculate_timer (struct thread
*t
)
630 struct ospf_lsa
*lsa
;
631 struct route_node
*rn
;
632 struct listnode
*node
;
633 struct ospf_area
*area
;
635 ospf
= THREAD_ARG (t
);
636 ospf
->t_ase_calc
= NULL
;
642 /* Calculate external route for each AS-external-LSA */
643 LSDB_LOOP (EXTERNAL_LSDB (ospf
), rn
, lsa
)
644 ospf_ase_calculate_route (ospf
, lsa
);
646 /* This version simple adds to the table all NSSA areas */
648 for (ALL_LIST_ELEMENTS_RO (ospf
->areas
, node
, area
))
650 if (IS_DEBUG_OSPF_NSSA
)
651 zlog_debug ("ospf_ase_calculate_timer(): looking at area %s",
652 inet_ntoa (area
->area_id
));
654 if (area
->external_routing
== OSPF_AREA_NSSA
)
655 LSDB_LOOP (NSSA_LSDB (area
), rn
, lsa
)
656 ospf_ase_calculate_route (ospf
, lsa
);
658 /* kevinm: And add the NSSA routes in ospf_top */
659 LSDB_LOOP (NSSA_LSDB (ospf
),rn
,lsa
)
660 ospf_ase_calculate_route(ospf
,lsa
);
662 /* Compare old and new external routing table and install the
663 difference info zebra/kernel */
664 ospf_ase_compare_tables (ospf
->new_external_route
,
665 ospf
->old_external_route
);
667 /* Delete old external routing table */
668 ospf_route_table_free (ospf
->old_external_route
);
669 ospf
->old_external_route
= ospf
->new_external_route
;
670 ospf
->new_external_route
= route_table_init ();
676 ospf_ase_calculate_schedule (struct ospf
*ospf
)
685 ospf_ase_calculate_timer_add (struct ospf
*ospf
)
690 if (! ospf
->t_ase_calc
)
691 ospf
->t_ase_calc
= thread_add_timer (master
, ospf_ase_calculate_timer
,
692 ospf
, OSPF_ASE_CALC_INTERVAL
);
696 ospf_ase_register_external_lsa (struct ospf_lsa
*lsa
, struct ospf
*top
)
698 struct route_node
*rn
;
699 struct prefix_ipv4 p
;
701 struct as_external_lsa
*al
;
703 al
= (struct as_external_lsa
*) lsa
->data
;
705 p
.prefix
= lsa
->data
->id
;
706 p
.prefixlen
= ip_masklen (al
->mask
);
707 apply_mask_ipv4 (&p
);
709 rn
= route_node_get (top
->external_lsas
, (struct prefix
*) &p
);
710 if ((lst
= rn
->info
) == NULL
)
711 rn
->info
= lst
= list_new();
713 /* We assume that if LSA is deleted from DB
714 is is also deleted from this RT */
716 listnode_add (lst
, ospf_lsa_lock (lsa
));
720 ospf_ase_unregister_external_lsa (struct ospf_lsa
*lsa
, struct ospf
*top
)
722 struct route_node
*rn
;
723 struct prefix_ipv4 p
;
725 struct as_external_lsa
*al
;
727 al
= (struct as_external_lsa
*) lsa
->data
;
729 p
.prefix
= lsa
->data
->id
;
730 p
.prefixlen
= ip_masklen (al
->mask
);
731 apply_mask_ipv4 (&p
);
733 rn
= route_node_get (top
->external_lsas
, (struct prefix
*) &p
);
735 #ifdef ORIGINAL_CODING
738 listnode_delete (lst
, lsa
);
739 ospf_lsa_unlock (lsa
);
740 #else /* ORIGINAL_CODING */
741 /* XXX lst can be NULL */
743 listnode_delete (lst
, lsa
);
744 ospf_lsa_unlock (lsa
);
746 #endif /* ORIGINAL_CODING */
750 ospf_ase_external_lsas_finish (struct route_table
*rt
)
752 struct route_node
*rn
;
753 struct ospf_lsa
*lsa
;
755 struct listnode
*node
, *nnode
;
757 for (rn
= route_top (rt
); rn
; rn
= route_next (rn
))
758 if ((lst
= rn
->info
) != NULL
)
760 for (ALL_LIST_ELEMENTS (lst
, node
, nnode
, lsa
))
761 ospf_lsa_unlock (lsa
);
765 route_table_finish (rt
);
769 ospf_ase_incremental_update (struct ospf
*ospf
, struct ospf_lsa
*lsa
)
772 struct listnode
*node
;
773 struct route_node
*rn
, *rn2
;
774 struct prefix_ipv4 p
;
775 struct route_table
*tmp_old
;
776 struct as_external_lsa
*al
;
778 al
= (struct as_external_lsa
*) lsa
->data
;
780 p
.prefix
= lsa
->data
->id
;
781 p
.prefixlen
= ip_masklen (al
->mask
);
782 apply_mask_ipv4 (&p
);
784 /* if new_table is NULL, there was no spf calculation, thus
785 incremental update is unneeded */
786 if (!ospf
->new_table
)
789 /* If there is already an intra-area or inter-area route
790 to the destination, no recalculation is necessary
791 (internal routes take precedence). */
793 rn
= route_node_lookup (ospf
->new_table
, (struct prefix
*) &p
);
796 route_unlock_node (rn
);
800 rn
= route_node_lookup (ospf
->external_lsas
, (struct prefix
*) &p
);
801 assert (rn
&& rn
->info
);
804 for (ALL_LIST_ELEMENTS_RO (lsas
, node
, lsa
))
805 ospf_ase_calculate_route (ospf
, lsa
);
807 /* prepare temporary old routing table for compare */
808 tmp_old
= route_table_init ();
809 rn
= route_node_lookup (ospf
->old_external_route
, (struct prefix
*) &p
);
812 rn2
= route_node_get (tmp_old
, (struct prefix
*) &p
);
813 rn2
->info
= rn
->info
;
816 /* install changes to zebra */
817 ospf_ase_compare_tables (ospf
->new_external_route
, tmp_old
);
819 /* update ospf->old_external_route table */
821 ospf_route_free ((struct ospf_route
*) rn
->info
);
823 rn2
= route_node_lookup (ospf
->new_external_route
, (struct prefix
*) &p
);
824 /* if new route exists, install it to ospf->old_external_route */
825 if (rn2
&& rn2
->info
)
828 rn
= route_node_get (ospf
->old_external_route
, (struct prefix
*) &p
);
829 rn
->info
= rn2
->info
;
833 /* remove route node from ospf->old_external_route */
837 route_unlock_node (rn
);
838 route_unlock_node (rn
);
844 /* rn2->info is stored in route node of ospf->old_external_route */
846 route_unlock_node (rn2
);
847 route_unlock_node (rn2
);
850 route_table_finish (tmp_old
);